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Publisher: Elsevier   (Total: 3162 journals)

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Showing 1 - 200 of 3162 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 9)
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 33, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 23, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 95, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 36, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 411, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 10, SJR: 0.18, CiteScore: 1)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.128, CiteScore: 0)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 251, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 27, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 6, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 6)
Acute Pain     Full-text available via subscription   (Followers: 14, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 16, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 8, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 9, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 150, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 12, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 28, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 10, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 23, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 14, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 32, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 8, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 3)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 27, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 29, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 12)
Advances in Digestive Medicine     Open Access   (Followers: 9)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 25)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 28, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 44, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 58, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Genetics     Full-text available via subscription   (Followers: 16, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 8, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 17, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 11, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 1)
Advances in Organ Biology     Full-text available via subscription   (Followers: 1)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 11)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 9)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 63)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 1, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 6)
Advances in Space Research     Full-text available via subscription   (Followers: 396, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 10, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 33, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 47, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 341, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 11, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 450, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 17, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 42, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 3)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 57, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 6, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 9)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 52, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 50, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 54, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 45, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 10)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 34, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 28, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 35, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 46)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 210, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 64, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 28, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 38, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 62, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 17, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 42, SJR: 1.512, CiteScore: 5)
Analytical Biochemistry     Hybrid Journal   (Followers: 176, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 11, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 11)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 23, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 194, SJR: 1.58, CiteScore: 3)

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Journal Cover
Advanced Powder Technology
Journal Prestige (SJR): 0.694
Citation Impact (citeScore): 3
Number of Followers: 17  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0921-8831 - ISSN (Online) 1568-5527
Published by Elsevier Homepage  [3162 journals]
  • An evaluation of machine learning and artificial intelligence models for
           predicting the flotation behavior of fine high-ash coal
    • Abstract: Publication date: Available online 15 October 2018Source: Advanced Powder TechnologyAuthor(s): Danish Ali, Muhammad Badar Hayat, Lana Alagha, Ontlametse Kenneth Molatlhegi In this study, five different machine learning (ML) and artificial intelligence (AI) models: random forest (RF), artificial neural networks (ANN), the adaptive neuro-fuzzy inference system (ANFIS), Mamdani fuzzy logic (MFL) and a hybrid neural fuzzy inference system (HyFIS) were employed to predict the flotation behavior of fine high ash coal in the presence of a novel “hybrid” ash depressant consisting of polyacrylamide chains grafted onto aluminium hydroxide nanoparticles: Al(OH)3-PAM (Al-PAM). A total of 51 flotation tests were conducted on coal samples with 38% ash-content and a P80 of approximately 49 μm. Different influencing variables of coal flotation including polymer dosage, pH, polymer conditioning time, sodium metasilicate dosage (commercial dispersant), and the impeller speed were used as inputs for the models. The combustible recovery and ash content of coal reported to the concentrate were used as response variables (outputs). For AI model development, 80% of the total data was used for training phase and 20% was used for testing phase. Coefficient of determination (R2) and root-mean-square error (RMSE) were used as performance indicators of the models. The MFL model showed the best accuracy for the prediction of the combustible recoveries and the froth ash contents for this specific feed. However, in case of any significant change in the characteristics of the feed, these models would have to be re-trained using the data obtained through further physical experimentation and/or process model simulations. Moreover as these models are trained on laboratory scale data, these are only good for the predictions at laboratory scale.Graphical abstractGraphical abstract for this article
       
  • Scalable microwave-assisted continuous flow synthesis of CuO nanoparticles
           and their thermal conductivity applications as nanofluids
    • Abstract: Publication date: Available online 13 October 2018Source: Advanced Powder TechnologyAuthor(s): Arun V. Nikam, Arun H. Dadwal We have demonstrated the novel and scalable synthesis of CuO nanoparticles by an integration of microwave and flow synthesis. The shape and size of CuO nanoparticles were tuned by changing the concentration of copper precursor. The production rate of CuO nanoparticles was found to be 5 g/h with 70% conversion of copper acetate into the CuO nanoparticles. The thermal conductivity of CuO nanofluid prepared in ethylene glycol showed linear enhancement with increase in the volume content of CuO nanoparticles produced in batch and flow reactors.Graphical abstractGraphical abstract for this article
       
  • A new approach for synthesis of ZnO nanorod flowerets and subsequent pure
           free-standing ZnO nanorods
    • Abstract: Publication date: Available online 13 October 2018Source: Advanced Powder TechnologyAuthor(s): B. Bhushan, B.S. Murty, K. Mondal Present work reports the synthesis of ZnO flowerets consisting of nanorod petals of ZnO having a mean aspect ratio ∼9, supported on micron sized Ni-enriched particles of size in the range of ∼1–4 μm and also free-standing pure ZnO nanorods from mechanically alloyed Ni-Zn powder particles via selective leaching in NaOH solution. Optimization of the composition of the initial alloy powder, the concentration of NaOH and time of exposure in the solution was carried out to get to the ZnO flowerets with an increment in the surface area of the order of 400%. The mechanism and reaction chemistry of ZnO nanorods formation and growth were explained based on the evidence of various characterization techniques including inductive coupled plasma mass spectroscopy (ICP-MS) and electrochemical measurements. Free-standing pure ZnO nanorods were also synthesized by ultrasonically breaking the rod petals of ZnO from the base of the flowerets. Free-standing ZnO nanorods have a mean aspect ratio of 8.5 ± 4, where the length and average diameter are ∼356 ± 64 nm and 42 ± 16 nm, respectively, and the specific surface area of 12.5 m2 g−1 with an increment of ∼650% as compared to the mechanically alloyed powder particle.Graphical abstractGraphical abstract for this article
       
  • Synthesis of Ag+/CaTiO3:Pr3+ with luminescence and antibacterial
           properties
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Zhu Liu, Kehui Qiu, Qinxue Tang, Yangting Wu, Junlan Wang In the study, CaTiO3:Pr3+ and Ag+ nano-particles-coated CaTiO3:Pr3+ red-emitting phosphors were synthesized by the citric acid sol combustion method. The photoluminescence properties and microstructures were investigated by photoluminescence spectroscopy, X-ray powder diffraction, and scanning electron microscopy. All samples showed the consistent orthorhombic crystal structure with standard CaTiO3. The photoluminescence measurements indicated that the all the experimental samples synthesized at 800 °C could be excited by 323 nm ultraviolent light and the emission intensity reached its maximum value at 619 nm. The Ag+ coating on the grain surface of CaTiO3:Pr3+ red-emitting phosphors had the antibacterial properties and the sample synthesized at 800 °C had optimal antibacterial properties. Moreover, the antibacterial property increased with the increase in the addition of Ag+ coating. The Ag+-coated CaTiO3:Pr3+ red-emitting phosphor excited by ultraviolent radiation is a promising red phosphor for manufacturing white-light-emitting diodes as well as antibacterial materials. This multi-functional material can be applied in many areas such as medical devices.Graphical abstract(a) X-ray diffraction patterns of the 1%Ag+/CaTiO3:0.2%Pr3+ samples obtained at different synthesis temperatures, (b) emission spectra of the 1%Ag+/CaTiO3:0.2%Pr3+ samples prepared at different temperatures, (c) Relative diameters of the inhibition zone for different contents of xAg+/CaTiO3:0.2%Pr3+ synthesized at 800 °C: A: x = 0.1, B: x = 0.2, C: x = 0.4, D: x = 0.6, E: x = 0.8, F: x = 1.0 and (d) Images of the inhibition zone photograph for different contents of xAg+/CaTiO3:0.2%Pr3+ synthesized at 800 °C: A: x = 0.1, B: x = 0.2, C: x = 0.4, D: x = 0.6, E: x = 0.8, F: x = 1.0.Graphical abstract for this article
       
  • One-pot synthesis of Al2O3 modified mesoporous ZrO2 with excellent thermal
           stability and controllable crystalline phase
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Zhichao Miao, Zhenbin Li, Cong Suo, Jinping Zhao, Weijiang Si, Jin Zhou, Shuping Zhuo In this paper, a series of Al2O3 modified mesoporous ZrO2 (M-ZrAl) materials are designed and achieved through a one-pot EISA strategy. As proved by different characterizations, the introduced Al2O3 species exist as highly dispersed states, and the crystalline phase (t-ZrO2 and m-ZrO2) of M-ZrAl material could be accurately controlled through adjusting the content of Al2O3 species. Moreover, the M-ZrAl-10 material exhibits excellent textural properties (specific surface area (56 m2·g−1), pore size (8.2 nm) and pore volume (0.13 cm3·g−1)) even treated at 800 °C. The obtained materials are employed as support for MoO3/M-ZrAl solid acid catalyst, and the relationship between catalytic performance (Friedel-Crafts alkylation, acetalization and esterification) and crystalline structure of support is specially explored. The result shows that the support with t-ZrO2 phase is beneficial for the formation of acid sites and enhancement of catalytic performance for the MoO3/M-ZrAl solid acid catalyst.Graphical abstractGraphical abstract for this article
       
  • Effect of polyethyleneimine-fatty acid complex type dispersant structure
           on the overall processing chain of Si3N4 ceramics using multicomponent
           non-aqueous slurries
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Motoyuki Iijima, Naoki Okamura, Junichi Tatami The effect of fatty acid structure of polyethyleneimine (PEI)-fatty acid complex, which was designed as a polymer dispersant for multi-component non-aqueous slurries, on the overall processing chain of Si3N4 ceramics involving slurry stabilization, spray drying, compaction, and liquid sintering was investigated using PEI-oleic acid (PEI-OA) and PEI-isostearic (PEI-ISA) complexes. Si3N4-Y2O3-Al2O3-AlN-TiO2/toluene slurries were selected as a real model for Si3N4-based multicomponent slurries. It was observed that both PEI-OA and PEI-ISA can stabilize Si3N4-Y2O3-Al2O3-AlN-TiO2/toluene slurries; however, the PEI-ISA system tended to have slightly higher slurry viscosity, which was suspected to be due to the interactions between protruded PEI segments among short ISA chains. The spray-dried granules from PEI-ISA-stabilized slurry were observed to have filled structures with higher surface roughness whereas those prepared from PEI-OA-stabilized slurry were observed to have hollow-structured granules. The granules prepared from PEI-OA slurry had improved flow and compaction properties with higher relative density of green compacts compared with those prepared from PEI-ISA-stabilized slurry, whereas the relative density and microstructural homogeneity of S3N4 ceramics sintered at 1600 °C for 2 h were observed to be higher for the PEI-ISA system. It is suspected that PEI-OA effectively improved the dispersion stability of multicomponent slurries and flow/compaction properties of granules; however, the inhomogeneous microstructures of green compacts induced by the hollow-structured granules had an adverse effect on the sintering of Si3N4 ceramics.Graphical abstractGraphical abstract for this article
       
  • Development of Venturi negative-pressure secondary dedust device and
           application of local spray closure technique
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Biao Sun, Weimin Cheng, Jiayuan Wang, Hao Wang, Youying Ma In order to enhance the spray for dust suppression performance in a fully-mechanized mining face, based on orthogonal test, comparison test, numerical simulation and field application, the Venturi negative-pressure secondary dedust device was developed. Meanwhile, the local spray closure technique was proposed, which can not only effectively prevent the escape of coal dust from entering the footway space, but also remove coal dust around the respiratory zone from the footway space successfully. The results demonstrated that, under spray pressure of 6 MPa, the Sauter mean droplet size, negative pressure suction flow rate and effective spray distance of the novel dedust device with a throat-to-nozzle distance and throat diameter of 20 mm and 65 mm were 47.37 µm, 11.21 m3/min and 5.4 m respectively. Moreover, the novel dedust device produced droplets to a smaller scale than a single-nozzle. Additionally, the negative pressure and airflow velocity in the negative pressure suction inlet of novel dedust device were within the range from −0.97 Pa to −541.04 Pa and from 2.96 m/s to 27.29 m/s respectively. Finally, compared with the original dust suppression measures, the local spray closure technique can enhance the removal ratio of respiratory dust by an average of 44.3%.Graphical abstractGraphical abstract for this article
       
  • Quantitative investigation of particle formation of a model pharmaceutical
           formulation using single droplet evaporation experiments and X-ray
           tomography
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Frederik J.S. Doerr, Iain D.H. Oswald, Alastair J. Florence The implementation of a particle design platform that can be applied to novel pharmaceutical systems using acoustic levitation (SAL) and X-ray tomography (XRT) is discussed. Acoustic levitation was employed to provide a container-less particle design environment for single droplet evaporation experiments. Dried particles were subject to further visual and quantitative structural analysis using X-ray tomography to assess the three-dimensional volume space. The workflow of the combined SAL-XRT platform has been applied to investigate the impact of increasing HPMC K100LV concentrations on the evaporation, drying and final particle morphology of particles from a model pharmaceutical formulation containing metformin and D-mannitol. The morphology and internal structure of the formulated particles after drying are dominated by a crystalline core of D-mannitol partially suppressed with increasing HPMC K100LV additions. The final structure can be correlated to the observed evaporation kinetics. The characterisation of formulated metformin hydrochloride particles with increasing polymer content demonstrated the importance of an early-stage quantitative assessment of formulation-related particle properties. The ability to study the evolution of solid phase formation and its influence on the final particle morphology can enable the selection of formulation and process parameter that deliver the desired particle structure and consequent performance by design.Graphical abstractGraphical abstract for this article
       
  • A new method for evaluating powder flowability using constant-volume shear
           tester,
    • Abstract: Publication date: Available online 12 October 2018Source: Advanced Powder TechnologyAuthor(s): Yasuhiro Shimada, Shigenobu Hatano, Shuji Matsusaka This is an article translated from the original version published in the Journal of the Society of Powder Technology, Japan. A new method for evaluating powder flowability is developed using a constant-volume shear tester; this tester measures the upper and lower normal stresses and the shear stress acting on a powder bed. A single shear test provides a series of characteristics, such as the powder yield locus (PYL), consolidation yield locus (CYL), critical state line (CSL), shear cohesion, stress relaxation ratio, stress transmission ratio, and void fraction. The values of shear stress as a function of the normal stress and void fraction are visualized in three-dimensional diagrams. Furthermore, powder flowability is evaluated using a flow function obtained from the PYL.Graphical abstractGraphical abstract for this article
       
  • Bi2S3 nanoparticles by facile chemical synthesis: Role of pH on growth and
           physical properties
    • Abstract: Publication date: Available online 11 October 2018Source: Advanced Powder TechnologyAuthor(s): Y. Ramos Reynoso, A. Martinez-Ayala, Mou Pal, F. Paraguay-Delgado, N.R. Mathews In this work, we have synthesized Bi2S3 nanoparticles (NPs) by facile chemical precipitation method. The reaction conditions were optimized in order to obtain high yield in a short time. The nanoparticles were synthesized at different pH values ranging from 0.5 to 1.6 and the effect of pH on the growth was investigated. XRD, Raman spectroscopy, SEM, HRTEM, XPS and UV–Vis spectroscopy, Seebeck were used for the characterization of the nanoparticles. The XRD patterns and Raman analysis revealed the formation of orthorhombic Bismuthunite without any impurity phases. The crystal size of the samples was found to decrease with the increase in pH. SEM images showed that NPs synthesized at pH lower than 1.2 are nanorods and tend to agglomerate as microspheres. At pH 1.6, morphology changes from nano-rods to nano-flakes, and from micro-spheres to micro stems decorated with nano-branches. A possible growth mechanism for the observed pH dependent morphological change is discussed. The estimated band gap energy is in the range of 1.35–1.42 eV. The thermoelectric measurements showed n-type conductivity and high Seebeck coefficients for Bi2S3 NPs.Graphical abstractGraphical abstract for this article
       
  • Impact of polymers on the aggregation of wet-milled itraconazole particles
           and their dissolution from spray-dried nanocomposites
    • Abstract: Publication date: Available online 10 October 2018Source: Advanced Powder TechnologyAuthor(s): Ecevit Bilgili, Mahbubur Rahman, Danny Palacios, Faustin Arevalo We explore the impact of various polymers and their molecular weight on the stabilization of wet-milled suspensions of itraconazole (ITZ), a poorly soluble drug, and its dissolution from spray-dried suspensions. To this end, ITZ suspensions with SSL, SL, and L grades of hydroxypropyl cellulose (HPC) having molecular weights (MWs) of 40, 100, and 140 kg/mol, respectively, hydroxypropyl methyl cellulose (HPMC E3 with 10 kg/mol), polyvinylpyrrolidone (PVP K30 with 50 kg/mol), sodium dodecyl sulfate (SDS, surfactant), and HPC SL–SDS were wet media milled and spray-dried. Laser diffraction results show that 2.5% HPC SL–0.2% SDS led to the finest ITZ nanosuspension, whereas without SDS, only 4.5% HPC with SL/L grades ensured minimal aggregation. Rheological characterization reveals that aggregated suspensions exhibited pronounced pseudoplasticity, whereas stable suspensions exhibited near Newtonian behavior. Spray-drying yielded nanocomposites with 60–78% mean ITZ loading and acceptable content uniformity. Severe aggregation occurred during milling/drying when 4.5% polymers with MW ≤ 50 kg/mol were used; their nanocomposites exhibited incomplete redispersion due to slow matrix erosion and released ITZ slowly during dissolution test. Overall, high drug-loaded, surfactant-free ITZ nanocomposites that exhibited immediate release (>80% dissolved in 20 min) were prepared via spray-drying of wet-milled ITZ with 4.5% HPC SL/L.Graphical abstractGraphical abstract for this article
       
  • Effect of flow pulsation on fluidization degree of gas-solid fluidized
           beds by using coupled CFD-DEM
    • Abstract: Publication date: Available online 6 October 2018Source: Advanced Powder TechnologyAuthor(s): Reza Namdarkedenji, Kamyar Hashemnia, Homayon Emdad In this paper, the effect of inlet flow type on fluidization of a gas-solid fluidized bed was studied by using numerical simulations. Gas-solid fluidized beds are widely used in processes such as heating, cooling, drying, granulation, mixing, segregating and coating. To simulate the gas-particle flows, the unresolved surface CFD‐DEM was used considering Eulerian–Lagrangian approach. The fluid phase was modeled by computational fluid dynamics (CFD) while the solid phase was solved by discrete element method (DEM), and the coupling between gas and solid phases was considered to be four-way. The uniform and pulsed flows were injected through three nozzles located at the bottom of a rectangular bed. Three types of pulsed flow were considered: sinusoidal, rectangular and relocating. The fluidized bed behavior was discussed in terms of minimum fluidization velocity (MFV), pressure drop, bubble formation, bed expansion, particles velocity and, gas-solid interaction and particle contact forces. The results of different simulations indicated that the minimum fluidization velocity of the beds fluidized by pulsed flows was decreased by up to 33%. The influence of the pulsation amplitude on the minimum fluidization velocity was more significant than that of the pulsation frequency. The bed expansion and particles average velocity were increased by the pulsed flows, while the pressure drop and interaction force were decreased. As the pulsation frequency increased, the pressure drop and gas-solid interaction force increased, although size of the bubbles and bed expansion decreased. It was also observed that in large vibration frequencies, the bubbles became more regular. In the sinusoidal flow, the velocity and contact force between the particles were initially increased by frequency and in larger frequencies they were decreased.Graphical abstract(a) Distributions of particles and (b) gas velocity contours for the bed fluidized by sinusoidal flow at superficial velocity of u = 0.5 m/s, frequency of 5 Hz and amplitude of 0.25 m/s in three time steps.Graphical abstract for this article
       
  • Estimating surface area of copper powder: A comparison between
           electrochemical, microscopy and laser diffraction methods
    • Abstract: Publication date: Available online 5 October 2018Source: Advanced Powder TechnologyAuthor(s): Sachin D. Giri, A. Sarkar For heterogeneous catalytic/electrocatalytic reaction systems, estimation of the surface area of the catalyst is of great importance. As far as systems involving copper as catalyst are concerned, the literature reveals lack of a robust method to determine the surface area. In this work, we compare the surface area determined from electrochemical measurements, optical and electron microscopy and from laser diffraction experiments. Specifically, cyclic voltammetry in two different solutions involving two separate surface reactions has been used to measure the surface area. First involves the formation of a monolayer of Cu2O and the second involves formation of a monolayer of Pb. Additionally, the surface area was also estimated from the double layer capacitance of the copper electrode. The surface areas determined from these electrochemical measurements are in good agreement with those obtained from microscopy and particle size analyzers (for average copper particle diameter = 10 µm).Graphical abstractGraphical abstract for this article
       
  • The preparation, formation mechanism and magnetic properties of a
           Fe-Cr-Mn-N amorphous alloy
    • Abstract: Publication date: Available online 5 October 2018Source: Advanced Powder TechnologyAuthor(s): Jian Kong, Xinxiang Song, Xueli Shao, Xiangkui Liu, Shuai Feng In this paper, the amorphous phase formation process, formation mechanism and magnetic properties, during the mechanical alloying (MA), have been investigated in Fe60Cr15Mn10N15 alloy, respectively. The results obviously indicate that amorphous Fe60Cr15Mn10N15 with a wide supercooled liquid region (SCLR, 82 K) can be obtained via 40 h MA process. With the milling time increasing gradually, the microstructures evolve from the initial crystalline powder, to completely amorphous phase, and eventually to amorphous phase with embedded Cr2N. By calculation, the mixing chemical enthalpy ΔHchem and amorphous formation enthalpy ΔHform have been obtained as −0.24 kJ/mol and −6.610 kJ/mol, respectively, implying the existence of thermodynamic advantage for the amorphous phase formation. In addition, the effect of 7 at% B and 7 at% Mo addition on the amorphous phase formation have also been studied, however, the diffraction peaks corresponding to Mo (Cr2N) still appear after 120 h milling. Meanwhile, isothermal annealing experiments were conducted at different temperatures, obtaining the microstructure evolution as: amorphous → amorphous alloy + Cr2N → α-Fe + Cr2N → α-Fe + CrN + Cr2N. And the hysteresis loops in amorphous Fe60Cr15Mn10N15 undergoing both the MA process and isothermal annealing procedure provide us with the evidence that this alloy system can exhibit excellent soft magnetic properties.Graphical abstractGraphical abstract for this article
       
  • Discrete element model development of ZTA ceramic granular powder using
           micro computed tomography
    • Abstract: Publication date: Available online 5 October 2018Source: Advanced Powder TechnologyAuthor(s): A. Tahir, S. Rasche, C. Könke Particle based simulations in 3D space using discrete element method provide valuable insight into the static and dynamic granular phenomena. Such phenomenon have to be considered during the production of ceramic components made up of dry pressed granulated ceramic powders. In the present work, 3D geometric parameters of zirconia toughened alumina (ZTA) granules in terms of their shape, size and spatial distribution are obtained using state of the art micro computed tomography (μCT). Computed tomography data provided an ample amount of information to obtain a 3D arrangement of particles in a defined space for discrete element method simulations. However, during simulations, the residual forces initiate spatial disturbance of the particles which lead to their rearrangement, despite the fact that the particle assembly while scanning was in a static equilibrium. Further appropriate μCT data processing steps along with statistical analyses of the polydisperse particle system are therefore proposed to dissolve the paradox. Possible pitfalls of model development are identified and corrected by geometrical and physical constraints. It is observed that the frequency of particle contacts can be used to characterize the stability of a particle system. Thereby, a coherent and consistent model in the form of a stable particle assembly for discrete element simulations is successfully developed.Graphical abstractGraphical abstract for this article
       
  • Simulated pulsed flow of gas and particles in a horizontal oppose-pulsed
           gas jets of bubbling fluidized bed
    • Abstract: Publication date: Available online 4 October 2018Source: Advanced Powder TechnologyAuthor(s): Lin Wang, Guoli Qi, Ming Tao, Xuemin Liu, Muhammad Hassan, Huilin Lu Flow behavior of gas and particles with a horizontal oppose-pulsed gas jets are simulated by means of a three dimensional Computational Fluid Dynamics (CFD) model with the kinetic theory of granular flow in a gas-particles bubbling fluidized bed. The effects of amplitudes and frequencies on the hydrodynamics of gas and particles are analyzed. The simulation results are presented in terms of phase velocity vector plot, volume fraction of phases, granular temperature, power spectrum and Reynolds stresses in the bed. Results show that the impingement caused by the oppose-pulsed gas jets oscillates with the variation of pulsed gas velocity. The impingement zone with the high solid volume fraction reciprocates from the left side to the right side through the bed center with the variation of pulsed jet gas velocities. The lateral velocity and gas turbulent kinetic energy, granular temperature and Reynolds stresses of gas and particles are larger near the pulsed gas jets than that at the center of the bed. The large dispersion coefficients of particles using the horizontal oppose-pulsed gas jets enhance the mixing of particles in gas-solid fluidized bed.Graphical abstractThe dispersion coefficients are calculated using simulated granular temperatures and frequencies at three positions.Graphical abstract for this article
       
  • Self-organization of colloidal particles during drying of a droplet:
           Modeling and experimental study
    • Abstract: Publication date: Available online 3 October 2018Source: Advanced Powder TechnologyAuthor(s): Katarzyna Jabłczyńska, Jakub M. Gac, Tomasz R. Sosnowski Formation of structurized micro/nanoparticle aggregates in spray drying process is analyzed theoretically and experimentally. Colloids of mono- and bimodal particle size distribution are used as the precursors to demonstrate different patterns of particle self-organization inside the drying droplet. In case of monodisperse primary particles their self-organization in the final aggregate results in either a hollow or a full (packed) spherical structure. For primary particles with bimodal size distribution, either the layered structure of aggregates is formed (with smaller particles forming outer layer and the bigger particles captured inside) or the ordering of bigger particles on the aggregate surface is observed, depending on process parameters. Numerical investigations allow to predict and explain the conditions at which self-assembling of particles within powder aggregates takes place.Graphical abstractGraphical abstract for this article
       
  • Self-assembly of the Ag deposited ZnO/carbon nanospheres: A resourceful
           photocatalyst for efficient photocatalytic degradation of methylene blue
           dye in water
    • Abstract: Publication date: Available online 29 September 2018Source: Advanced Powder TechnologyAuthor(s): Sonal Singhal, Saurabh Dixit, A.K. Shukla Carbon nanospheres (CNSs) are synthesized by pyrolysis of benzene at 1000 °C. Various UV-light photocatalysts of ZnO/CNSs and Ag-ZnO/CNSs (AZCN) composites are synthesized on the surface of CNSs using a facile chemical precipitation method. Morphological and optical properties of the as-synthesized photocatalysts are characterized by scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, UV-Vis spectroscopy, photoluminescence and Raman spectroscopy. Photocatalytic degradation efficiency of methylene blue dye is investigated to examine the photocatalytic activity of synthesized photocatalysts. It is found that as-synthesized ZnO/CNSs composite can degrade higher methylene blue dye (∼85.6%) after 25 min of UV irradiation in comparison with that of CNSs. A prominent improvement in the photodegradation is attained by depositing metal (Ag) particles on the surface of ZnO/CNSs composite. AZCN composite displays the enhanced photocatalytic degradation performance (∼95% after 15 min of UV light) in high concentration of methylene blue dye. Furthermore, stability performance is studied by recycling the AZCN composite photocatalyst. It is found that the photocatalytic activity of AZCN composite is only slightly decreased even after five cycles. Present work demonstrates that AZCN composite show a great potential in the treatment of organic pollutants for wastewater treatment.Graphical abstractGraphical abstract for this article
       
  • Fragmentation in oblique impaction for nanoparticle-agglomerates with
           different structures
    • Abstract: Publication date: Available online 29 September 2018Source: Advanced Powder TechnologyAuthor(s): M. Gensch, A.P. Weber Impact fragmentation can be used to disperse nanoparticle-agglomerates. While the fragmentation of openly structured (fractal dimension Df 
       
  • Fabrication of controlled expansion Al-Si composites by pressureless and
           spark plasma sintering
    • Abstract: Publication date: Available online 27 September 2018Source: Advanced Powder TechnologyAuthor(s): Asraful Haque, S. Shekhar, S.V.S. Narayana Murty, J. Ramkumar, K. Kar, K. Mondal A combination of low coefficient of thermal expansion (CTE) and decent thermal conductivity (TC) is the reason for the Al-high vol% Si system to become popular for electronic packaging material. In the present work, two process routes, firstly conventional powder metallurgy and then spark plasma sintering (SPS) were utilized for the fabrication of Al-20-60 wt.% Si composites. In addition, effect of small fraction of CNT addition on the CTE of Al-20 wt% Si was studied. Effect of process parameters on the consolidation of the composites in terms of densification, microstructure evolution along with fractographic analysis and strength was studied. CTE and TC of the sintered composites were measured and correlated with the densification, percentage of Si and morphologies of the sintered products. Overall, better densification could be achieved in SPS and the Al-30%Si and Al-40%Si composites SPSed at 550 °C showed average CTE values of 14.52 × 10−6/K and 13.36 × 10−6/K, respectively, in the temperature range of 30–200 °C, which were better than some of the existing alloys with higher Si content. Simultaneously, TC values were 114.4 W/mK and 107.12 W/mK, respectively, for the above two SPSed composites.Graphical abstractGraphical abstract for this article
       
  • Influence of reduced graphene oxide on structural, optical, thermal and
           dielectric properties of SnO2 nanoparticles
    • Abstract: Publication date: Available online 27 September 2018Source: Advanced Powder TechnologyAuthor(s): Ateeq Ahmed, M. Naseem Siddique, T. Ali, P. Tripathi The present work has been carried out with the aim to synthesize tin oxide decorated reduce graphene oxide nanocomposite (SnO2/RGO-Nc) via in-situ synthesis process and the influence of RGO loading on structural, optical, thermal and dielectric properties of SnO2 has been discussed. The XRD, FESEM coupled with EDX elemental mapping, TEM, FTIR, Raman and XPS results reveal that the SnO2 nanoparticles have been successfully incorporated onto the RGO sheets. The reduction in the energy gap of the composite sample as compared to SnO2 measured from the Tauc’s relation can be attributed to strong coupling between RGO and SnO2 NPs. Thermogravimetric analysis (TGA) shows improved thermal stability of the SnO2/RGO-Nc. From the dielectric measurements, it is observed that the dielectric constant and dielectric loss decreases as frequency of applied field increases. AC conductivity of all samples increases as applied frequency increases which follows Jonscher’s power law. All composite samples show better conductivity as compared to SnO2. This is due to the formation of continuous conductive pathway between SnO2 and RGO sheets. Further high dielectric constant, low loss and high ac conductivity have been observed at optimum loading of RGO in SnO2/RGO2-Nc as compared to other composite samples which is due the percolation effects. The impedance analysis exhibits only one semicircle for SnO2 and SnO2/RGO composite which suggests that the involvement of grain boundaries dominated over the grain contribution.Graphical abstractGraphical abstract for this article
       
  • Mesoporous nanocrystalline ZnO microspheres by ethylene glycol mediated
           thermal decomposition
    • Abstract: Publication date: Available online 27 September 2018Source: Advanced Powder TechnologyAuthor(s): Emre Alp, Emre Can Araz, Ahmet Furkan Buluç, Yağmur Güner, Yücel Deger, Halil Eşgin, Kamil Burak Dermenci, M. Kürşat Kazmanlı, Servet Turan, Aziz Genç Zinc oxide (ZnO) nanostructures with various morphologies have been fabricated in literature owing to their potential applications in various emerging fields. In this study, we report a facile, one-step gram-scale synthesis of nanocrystalline mesoporous ZnO microspheres by thermal decomposition of zinc acetate dihydrate in ethylene glycol at 250 °C for 12 h. The average size of the hollow microspheres is found to be 3.01 ± 0.52 µm, which are formed by loosely bonded nanocrystallites with average sizes of 17 ± 4 nm. We propose a formation mechanism for the mesoporous microspheres, Ostwald ripening of spherical-like nanocrystallites, on the basis of the results obtained by different synthesis durations. We also report the possibility of tuning the morphologies of the obtained ZnO by simply modifying the thermal decomposition solution, where porous ZnO nanoplates are obtained when a mixture of ethylene glycol and water is used and ZnO nanorods with aspect ratios of ∼3 are synthesized by using diethylene glycol. ZnO nanowires with lengths up to several microns are fabricated when no solvent is used, i.e. thermal decomposition in air atmosphere. Microstructural and phase characterizations of the samples are conducted by using a field-emission gun scanning electron microscope and X-ray diffractometer. Performances of the obtained nanocrystalline mesoporous ZnO microspheres in photocatalytic degradation of Rhodamine B and as active anode materials in lithium-ion batteries are also presented.Graphical abstractGraphical abstract for this article
       
  • Particle size induced heterogeneity in compacted powders: Effect of large
           particles
    • Abstract: Publication date: Available online 25 September 2018Source: Advanced Powder TechnologyAuthor(s): Bereket Yohannes, Xue Liu, Gary Yacobian, Alberto M. Cuitiño We investigated the effect of particle size distribution on heterogeneity of compacted powders. We used experiments and discrete particle based simulations to compact powders, test the mechanical strength of the compact, and study the microstructure of the compact. A metallic powder which has a wide particle size distribution was used in the experiments. We found that the compaction profile is not reproducible when particles larger than 1/6 of the die diameter are present in the powder sample. The presence of these large particles generate a highly heterogeneous inter-particle contact and bonding forces. The discrete particle simulations showed that for these heterogeneous compacts the tensile strength exhibits high variability, even for one compact if the diametrical compression force is applied along different axes. Based on these results, it is recommend that the largest particle in a powder compact should not exceed one sixth the die diameter, which is the same as the recommendation of ASTM International D4767 - 11 for compression test of cohesive soils.Graphical abstractGraphical abstract for this article
       
  • Experimental and CFD study on effects of spiral guide vanes on cyclone
           performance
    • Abstract: Publication date: Available online 25 September 2018Source: Advanced Powder TechnologyAuthor(s): Faqi Zhou, Guogang Sun, Xiaopeng Han, Yong Zhang This paper presents an experimental and numerical study on a tangential inlet cyclone separator with a spiral guide vane which is not often researched. Numerical pressure drop results were in close agreement with the experimental data. The spiral guide vane was also found to considerably influence the velocity distribution, turbulence intensity, pressure drop and collection efficiency in the cyclone. A critical value of spiral guide vane turns appeared below or above which there was a marked increase in collection efficiency, pressure drop, and tangential velocity. Compared to a cyclone with zero spiral guide vane turn, the maximal decrease in collection efficiency in the cyclone with the critical spiral guide vane turns (one turn) was 2% approximately. The maximum-efficiency inlet velocity appeared to exist independent of spiral guide vane turns, as inlet velocity affected the radial distance traveled by the rebounded particles from the inner wall. The analysis of flow field in cyclones indicated that the flow field was improved with the spiral guide vanes employed to some extent. The results presented here may provide a workable reference for the effects of spiral guide vanes on the flow field and corresponding performance in cyclone separators.Graphical abstractA critical value of spiral guide vane turns appeared below or above which there was a marked increase in collection efficiency and tangential velocity. The maximum-efficiency inlet velocity appeared to exist independent of spiral guide vane turns, as inlet velocity affected the radial distance traveled by the rebounded particles from the inner wall.Graphical abstract for this article
       
  • CFD simulation of particle segregation in a rotating drum. Part II:
           Effects of specularity coefficient
    • Abstract: Publication date: Available online 24 September 2018Source: Advanced Powder TechnologyAuthor(s): An-Ni Huang, Hsiu-Po Kuo Segregation of binary particle mixture in a rotating drum is numerically studied using the Eulerian multiphase computational fluid dynamics (CFD) simulations coupling the solid phase kinetic theory of granular flow model. The corresponding solid kinetic viscosities of the two particulate phases are determined by the previous granular bed surface fitting (BSF) method. The effects of the specularity coefficients used in the simulations on the segregation patterns in the rotating drums are systematically studied by using the specularity coefficient values ranging from 0.15 to 1.0. When using a smaller specularity coefficient value in the simulation, the momentum transferring from the drum wall to the particulate phase is poorer, lowering the kinetic energy of the particulate phase. The lower particulate phase kinetic energy causes slower particle motion in the bed and hence delays the segregation core/band formation. At the same simulation time, the concentration of the smaller particles in the segregation core increases with the increasing of the specularity coefficient value used in the simulation. When the specularity coefficient values larger than 0.4 are used in our simulations, the realistic three-dimensional segregation structures are well predicted. A proper specularity coefficient value should be adopted in Eulerian multiphase CFD simulations of granular flows.Graphical abstractGraphical abstract for this article
       
  • Influence of Ar plasma treatment on the wetting behavior of pharmaceutical
           powders
    • Abstract: Publication date: Available online 24 September 2018Source: Advanced Powder TechnologyAuthor(s): Deepa Dixit, Shreya Bunk, Ramkrishna Rane, Chinmay Ghoroi In this study, corn starch and ibuprofen are treated in Argon (Ar) plasma to enhance the wettability of the powders without using any additive or guest particle. The powder and pellets were exposed to the Ar plasma for different time intervals (5–20 min) at optimized pressure and voltage. While the morphological changes due to plasma exposure are captured by SEM, the AFM measurement shows the variations in surface roughness for both corn starch and ibuprofen powders. The XPS and surface energy results confirm that the surface groups change is dominating under initial exposure, but longer exposure creates more damaging effect than building the new active sites at the surface. The contact angle (CA) measurement shows that with increase in treatment time, the CA decrease from 48° to 33° for corn starch and 69° to 51° for ibuprofen. A comparison of experimentally obtained CA and that of theoretically calculated CA shows that there exists some difference. This may be attributed to the absence of surface group contribution in the Wenzel model. The present study shows that short exposure is sufficient enough to improve the wetting where the surface group plays a dominant role over surface roughness.Graphical abstractGraphical abstract for this article
       
  • Analysis of reverse cationic iron ore fines flotation using RSM-D-optimal
           design – An approach towards sustainability
    • Abstract: Publication date: Available online 24 September 2018Source: Advanced Powder TechnologyAuthor(s): Abhyarthana Pattanaik, Rayasam Venugopal Froth flotation is an important process to recover iron values from slimes, ore fines to meet the rapidly growing demand of quality iron ore concentrate for environmental and economic advantages. In the present study, responses of −75 µm iron ore fines to flotation was analysed at different variable parameters. The D-optimal design of response surface methodology was adopted to evaluate the effect of different reagents such as collector, frother, depressant, disperssant and pH on recovery and grade. The RSM-D optimal predicted responses with coefficient of determination (R2) 0.97 for recovery and 0.98 for grade of iron concentrate collected from tailing launder. The optimal conditions were collector = 0.21 kg/ton, frother = 0.10 kg/ton, depressant = 0.61 kg/ton, disperssant = 0.20 kg/ton, and pH = 11 with 64.13% Fe and 84.37% iron recovery respectively with a model desirability of 84.3%. Flotation performance was optimized by carrying out statistical design of experiments to identify main and international effects on maximum recovery and grade. This study showed that RSM-D-optimal could efficiently be applied for modelling of iron ore reverse flotation and it is very economic to obtain maximum amount of information in less interval of time with few number of experiments. Successful upgradation of low grade iron ore fines through reverse flotation route with proposed reagent regimes is envisaged.Graphical abstractGraphical abstract for this article
       
  • Novel use of waste glass powder: Production of geopolymeric tiles
    • Abstract: Publication date: Available online 24 September 2018Source: Advanced Powder TechnologyAuthor(s): Jhonathan F. Rivera, Zuleny I. Cuarán-Cuarán, Nathalie Vanegas-Bonilla, Ruby Mejía de Gutiérrez In industry, as well as in cities, a large amount of solid waste is produced, some of which is partially recycled or is disposed of in its entirety in landfills, thereby generating negative environmental effects. Of this waste, industrial waste glass from numerous application sources is a major source of pollution because only an estimated 30% is reused globally. In the search for an alternative outcome for waste, various applications have arisen, some of which are related to constructions sector. This research study concerns the use of waste from glass bottles, fluorescent lamps and soda-lime window glass, used in its entirety as a raw material in the manufacture of tiles by applying the technique of alkaline activation to generate an alkaline cementitious material. The feasibility of using the waste for the development of this type of cementitious material is enabled by the high content of silica in the glassy state. NaOH was used as activator in a concentration range from 4 to 10 M. Manually produced tiles, exhibit good properties as compressive strength of 178 (kg/cm2) and maximum load supported before rupture of 1006 (N). The use of these wastes contributes to environmental sustainability and generating more friendly building products.Graphical abstractGraphical abstract for this article
       
  • Viscosity and separation performance of a gas-solid separation fluidized
           beds
    • Abstract: Publication date: Available online 22 September 2018Source: Advanced Powder TechnologyAuthor(s): Bo Lv, Zhenfu Luo, Bo Zhang, Xingzong Qin A theoretical model of viscosity in gas-solid separation fluidized beds is established according to the two-phase flow theory of fluidized beds. After comparing theoretical and measured values, the correlation coefficient between the two is as high as 0.99, showing that the model has good predictability for the viscosity of fluidized beds. Meanwhile, the viscosity and its influencing factors were studied using a Brookfield viscometer. The study shows that smaller medium particles (0.074–0.15 mm) can reduce the viscosity of fluidized beds, but they will aggravate the viscosity fluctuation at more than 5 wt% addition, which is unfavorable to the stability of fluidized beds. In addition, in the actual separation process, the external factors (such as moisture and coal powder content) also affect the viscosity of the fluidized beds. Increasing the moisture increases the viscosity of the fluidized bed, whereas coal dust has the opposite effect. In order to ensure the stability of the fluidized bed, the bed moisture content should be controlled below 1 wt%, while the content of coal powder should be limited below 5 wt%. Based on separation tests, reducing the viscosity will improve the separation performance of a fluidized bed at the proper fluidized gas velocity, with the lowest possible error Ep of 0.085.Graphical abstractGraphical abstract for this article
       
  • Numerical investigation of gas-particle hydrodynamics in a vortex chamber
           fluidized bed
    • Abstract: Publication date: Available online 22 September 2018Source: Advanced Powder TechnologyAuthor(s): Subhajit Dutta, Chanchal Loha, Pradip Kumar Chatterjee, Anup Kumar Sadhukhan, Parthapratim Gupta Gas-particle hydrodynamic behaviour inside a vortex chamber fluidized bed is studied numerically with respect to different design and operating conditions. A three-dimensional computational fluid dynamics (CFD) model of a cylindrical vortex chamber is developed. Simulations are carried out with particles and without particles. In order to understand the gas-particle flow behavior velocity distribution, particle volume fraction distribution, radial pressure distribution and axial pressure distribution inside the vortex chamber are analyzed in detail. Particles of different diameters are used and its effect on the gas-particle flow behaviour is studied. Design parameters like the number of gas inlet slots and slot width are varied and their impact on the hydrodynamics of the vortex chamber is investigated. The numerical model is validated by comparing the numerical results with experimental results reported in literature.Graphical abstractVortex chamber fluidized bed which is a novel type of fluidized bed can be used for a number of applications due to its advantageous features. In the present work, the gas-particle hydrodynamic behaviour inside a vortex chamber fluidized bed is studied numerically. A three-dimensional Eulerian-Lagrangian based Computational Fluid Dynamics (CFD) model of the vortex chamber fluidized bed is developed. The numerical model is validated by comparing the numerical results with experimental results reported in literature. Effects of design parameters like number of gas inlet slots and slot width on the hydrodynamic behavior are studied. Simulations are also run with different particle sizes and their effects are studied. Hydrodynamic parameters like air velocity distribution, particle volume fraction distribution, radial and axial pressure distribution inside the vortex chamber are analyzed in detail. Figure below shows the particle volume fraction distribution inside the vortex chamber for 300 μm particles with 24 numbers of gas inlet slots of 3 mm width. It is observed that particles are well distributed throughout the vortex chamber and a dense rotating particle bed is formed near the periphery of the vortex chamber. The numerical model shows the capability of simulating the hydrodynamic behavior of vortex chamber fluidized bed quite well.Graphical abstract for this article
       
  • Heterogeneity of grain refinement and texture formation during pulsed
           electric current sintering of conductive powder: A case study in copper
           powder
    • Abstract: Publication date: Available online 22 September 2018Source: Advanced Powder TechnologyAuthor(s): Kewei Li, Fei Gao The heterogeneity of grain refinement and texture formation in conductive copper powder during pulsed electric current sintering have been investigated by means of microstructural analysis of the particle-contacting zone of the samples sintered with micron-sized powders. The particle-contacting region was indicated to experience a higher level of grain refinement than the particle center due to the inhomogeneous temperature distribution among the particle when pulsed electric current passed through. Meanwhile, two main textures of Cube (1 0 0)[0 0 1] texture and Goss (1 1 0)[0 0 1] texture were directly detected in the sintered Cu samples by a combination of electron backscatter diffraction and X-ray diffraction. Based on the experimental results, a feasible mechanism for the formation of texture during the pulsed electric current sintering has been proposed by considering the applied uniaxial pressure and pulsed electric current as well as the rearrangement of grains. In addition, the effects of heterogeneous grain refinement and texture formation on the tensile properties of the sintered Cu samples were also discussed based on the tensile properties and fractographic. These results would contribute to the basic understanding of the sintering mechanisms in pulsed electric current sintering process.Graphical abstractThe grain refinement in conductive Cu powder during pulsed electric current sintering is indicated to heterogeneous. The particle-contacting region is consisted of finer grains than the particle center resulting from the inhomogeneous temperature distribution among the particle when pulsed electric current passes through. Meanwhile, two main textures of Cube (1 0 0)[0 0 1] and Goss (1 1 0)[0 0 1] are directly detected by a combination of electron backscatter diffraction and XRD analysis in the sintered Cu samples. A possible mechanism for the formation of texture during the pulsed electric current sintering has been proposed by considering the applied uniaxial pressure and pulsed electric current as well as the rearrangement of grains.Graphical abstract for this article
       
  • Preparation and characterization of spray-dried submicron particles for
           pharmaceutical application
    • Abstract: Publication date: Available online 21 September 2018Source: Advanced Powder TechnologyAuthor(s): Ramona Strob, Adrian Dobrowolski, Damian Pieloth, Gerhard Schaldach, Helmut Wiggers, Peter Walzel, Markus Thommes The versatile use of submicron-sized particles (0.1–1 μm) requires new manufacturing methods. One possibility for the preparation of submicron-sized particles is spray drying. However, the generation of small droplets at a high production rate and the precipitation of submicron particles are quite challenging. In order to produce a sufficient amount of fine and uniform droplets, a two-fluid nozzle with internal mixing was combined with a cyclone droplet separator. The precipitation of particles was realized with an electrostatic precipitator. Considering the difficulty of electrostatic precipitation concerning explosion risks and to make it capable using organic solvents, the spray dryer was integrated in a pressure resistant vessel. Based on previous experiments, the now presented design is compact and the electrostatic precipitator is shortened. In addition, enhanced drying conditions ensured a controlled and reproducible preparation of submicron-sized particles. Thus, high separation efficiencies were shown. Spray-drying experiments were conducted with the model substance mannitol. With the cyclone droplet separator, a fine and uniform spray with a droplet size smaller 2 μm was produced. This robust atomizing technique is capable for high concentrations. For a 10 wt% mannitol solution, particles in the submicron range d50,3 = 0.7 μm were produced.Graphical abstractGraphical abstract for this article
       
  • Ternary MIL-100(Fe)@Fe3O4/CA magnetic nanophotocatalysts (MNPCs):
           Magnetically separable and Fenton-like degradation of tetracycline
           hydrochloride
    • Abstract: Publication date: Available online 19 September 2018Source: Advanced Powder TechnologyAuthor(s): Haroon Ur Rasheed, Xiaomeng Lv, Suyun Zhang, Wei Wei, Nabiullah, JiminXie Today’s world, tetracycline hydrochloride (TC) is considered as a Compounds of Emerging Concern (CECs). Metal-organic frameworks MOFs with a microporous structure and holding larger pores indicating potential applications in the fields of environmental purification. Recently, carbon aerogel (CA) has also aroused great interest due to its larger specific surface area, low density, thermal stability, and non-toxicity. Herein, MIL-100(Fe) was synthesized under low temperature and combined with Fe3O4 and CA, respectively. The obtained MIL-100(Fe), MIL-100(Fe)@Fe3O4, MIL-100(Fe)@CA and MIL-100(Fe)@Fe3O4/CA were investigated as a photocatalyst for removal of TC from the water. The results indicated that the MIL-100(Fe)@Fe3O4/CA degrade TC up to 85%, which is much higher than MIL-100(Fe)@Fe3O4 (c.a. 42%), due to its high surface area 389 m2 g−1, smaller pore size and pore volume 2.4 nm and 0.319 m3 g−1, high separation of electron and hole, and lower band gap of 1.76 eV. The coupling of CA with MIL-100(Fe)@Fe3O4 considerably accelerate the transfer of photo-generated charge carriers and enhanced 1.6 times the performance of MIL-100(Fe)@Fe3O4. Furthermore, the stability and recyclability were enhanced due to the addition of Fe3O4, facilitating the environmentally friendly water purification processes.Graphical abstractDegradation of TC through Ternary MIL-100(Fe)@Fe3O4/CA nanophotocatalysts. Enhanced performance through the addition of semiconductor for better charge transformation and limited the electron and holes combination.Superparamagnetic used for better recovery of the catalyst from the water.Graphical abstract for this article
       
  • Fast release of liquid antisolvent precipitated fenofibrate at high drug
           loading from biocompatible thin films
    • Abstract: Publication date: Available online 19 September 2018Source: Advanced Powder TechnologyAuthor(s): Mohammad A. Azad, Lucas Sievens-Figueroa, Rajesh N. Davé Motivated by recent papers on nano and micro-particle slurry casting of poorly water-soluble drugs forming biocompatible films with enhanced properties, this work explores incorporation of liquid antisolvent (LAS) precipitated suspensions of fenofibrate, a model poorly soluble drug using both semi-synthetic (HPMC E15 LV) and natural (sodium alginate, SA) polymer as film formers. Centrifugation and subsequent resuspension were employed to minimize residual solvent and increase drug loading (∼20%) in the LAS suspensions and in the film. Film’s critical quality attributes (CQAs), including drug distribution and uniformity, mechanical properties, and dissolution were assessed. Crystalline nature of FNB was largely preserved in the film without any polymorphic changes confirmed by XRD, DSC, and Raman. The NIR chemical imaging, corroborated by SEM imaging and drug content relative standard deviation (RSD) indicates that the drug is uniformly distributed without any observable large agglomerates. The films with SA showed lower mechanical strength as compared to HPMC due to SA’s low molecular weight. All films exhibited immediate drug release as has been the case using FNB nano particles in previous papers. Interestingly, although addition of plasticizer improved film dissolution, HPMC-based films had a faster dissolution compared to SA-based films in spite of higher mechanical strength of the former.Graphical abstractGraphical abstract for this article
       
  • Investigation of the influence of frictional viscosity regularization on
           quasi-static gas-solid flow predictions in a conical spouted bed with
           non-porous draft tube
    • Abstract: Publication date: Available online 18 September 2018Source: Advanced Powder TechnologyAuthor(s): N’dri A. Konan, E. David Huckaby The stress in the quasi-static particle flow is often modeled through the Mohr-Coulomb failure criterion. In the extension to complex three-dimensional flows, a granular viscosity is introduced through a tensorial rheology and the deviatoric frictional stress tensor is assumed aligned with the strain rate tensor. This granular viscosity is singular as the shear rate approaches zero, regardless of the local rheology. We discuss the influence of regularizing such a frictional viscosity on the particle circulation rate and other measured characteristics in a laboratory scale draft tube spouted bed. The friction between particles is modeled either with a constant Coulomb rheology or using a local particle pressure and strain-rate based friction known as μI-rheology. The predictions appear very dependent on the regularization parameter introduced by the method. The mean properties of the flow (e.g. circulation and pressure drop) monotonically converge towards the measurements when the regularization parameter tends to zero. In other respects, the two regularization models regarded in this study induced similar hydrodynamics within the spouted bed of interest. But the analysis of the conditional averages of the inertial number and the fraction of the solids in the quasi-static regime shows that the extent and staticity of the quasi-static region is sensitive to changes to the regularization parameter or regularization function.Graphical abstractGraphical abstract for this article
       
  • Hierarchical Bi2S3 nanoflowers: A novel photocatalyst for enhanced
           photocatalytic degradation of binary mixture of Rhodamine B and Methylene
           blue dyes and degradation of mixture of p-nitrophenol and p-chlorophenol
    • Abstract: Publication date: Available online 18 September 2018Source: Advanced Powder TechnologyAuthor(s): Surbhi Sharma, Neeraj Khare Hierarchical nanostructures of bismuth sulfide (Bi2S3) have been synthesized by a facile hydrothermal method. The potentiality of Bi2S3 hierarchical nanostructures for the photocatalytic degradation of Rhodamine B (RhB), Methylene blue (MB) and the mixture of RhB-MB organic dyes have been demonstrated and compared with commercial TiO2 (Degussa P25) sample under visible light illumination. The degradation efficiency of Bi2S3 and Degussa P25 is found to be higher in the single as well as in the binary dye solution for MB degradation as compared to RhB degradation. Furthermore, the degradation rate of RhB and MB is enhanced by ∼8 times and ∼3 times in their binary solution as compared to that in single dye solution. Whereas, Bi2S3 has demonstrated ∼14 times higher degradation rate of both RhB and MB in their binary solution than that of Degussa P25 for RhB and MB degradation in the binary solution under visible light exposure, respectively. Interestingly, Bi2S3 nanostructures has exhibited larger improvement in the degradation efficiency for RhB in its binary solution which is attributed to the faster separation of photogenerated charge carriers due to the proper alignments between the molecular orbits of dyes and band level positions of Bi2S3 in RhB-MB-Bi2S3 heterogenous system. The photocatalytic degradation study of colourless contaminants, p-chlorophenol (CP), p-nitrophenol (NP) and their mixture (CP-NP) is also investigated in the presence of Bi2S3 nanoflowers. Among the phenolic compounds, the degradation rate of NP is observed to be highest in the single solution. However, the degradation rate of both CP and NP is found to decrease in binary mixture solution in comparison to their individual solution. A possible mechanism for the enhanced photodegradation of RhB-MB dye mixture based on the active species trapping experiment has been proposed.Graphical abstractBismuth sulfide (Bi2S3) has been synthesized in the morphology of hierarchical nanostructures by facile hydrothermal method. The photocatalytic efficiency of Bi2S3 nanostructures has been checked for the degradation of MB, RhB single dye solution and their binary mixture and compared with commercial TiO2 (Degussa P25) sample under visible light illumination. The degradation rate of RhB and MB is enhanced by ∼8 times and ∼3 times in their binary solution as compared to that in single dye solution and increased by ∼14 times than that of Degussa P25 for both RhB and MB degradation in the binary solution, respectively. This remarkable improvement in the photocatalytic activity of Bi2S3 is attributed to the faster separation of charge carriers at the interface due to the favourable LUMO and HOMO alignment of RhB and MB with band levels of Bi2S3 in the RhB-MB-Bi2S3 trio system. The photocatalytic degradation study of colourless contaminants, p-chlorophenol (CP), p-nitrophenol (NP) and their mixture (CP-NP) is also investigated. The degradation rate of NP is observed to be highest in the single solution, whereas, the degradation rate of both CP and NP is found to decrease in binary mixture solution in comparison to their individual solution.Graphical abstract for this article
       
  • Numerical analysis of the general characteristics of stereological bias in
           surface liberation assessment of ore particles
    • Abstract: Publication date: Available online 18 September 2018Source: Advanced Powder TechnologyAuthor(s): Takao Ueda, Tatsuya Oki, Shigeki Koyanaka In mineral processing, ground ore particles containing valuable minerals are commonly separated from the gangue by flotation. For efficient flotation, surface liberation, in which the particle surface is composed of one phase, is important. Surface liberation is commonly measured by two-dimensional (2D) measurement of particle sections of resin-mounted samples. Such 2D measurement is considered to result in a form of error called stereological bias; however, the stereological bias associated with surface liberation assessment has not been fully studied. A series of numerical simulations was here conducted, to investigate the influence of a particle’s texture (the 3D internal particle structure) and shape on such stereological bias. First, a total of 110 patterns of texture (10 patterns of grain size times 11 levels of grain content) were modeled, to determine the general characteristics of the stereological bias. Then, the influence on the stereological bias, of particle shape as represented by the aspect ratio (an index of global shape) and corrected sphericity (an index of surface roughness), was investigated. The results revealed that texture had the largest, aspect ratio the second largest, and corrected sphericity the smallest influence on the stereological bias in surface liberation measurement. Based on the results, it is suggested that a rough estimate of the stereological bias in the measurement of irregularly shaped real ore particles can be made from much simpler numerical models of spherical particles.Graphical abstractGraphical abstract for this article
       
  • Multi-walled carbon nanotube laden with D-Mannitol as phase change
           material: Characterization and experimental investigation
    • Abstract: Publication date: Available online 17 September 2018Source: Advanced Powder TechnologyAuthor(s): Srikanth Salyan, S. Suresh In this paper, multi-walled carbon nanotubes (CNT) were dispersed in D-Mannitol to prepare enhanced thermal conductive nanocomposites phase change materials (PCM) with 0.1% and 0.5% weight fraction. The PCM were tested for 100 thermal cycles and characterized by using techniques such as Differential Scanning Calorimetry (DSC), Thremogravimetric analyser (TGA) and Fourier Transform Infrared (FT-IR). The effect of adding CNT on energy storage/release performance of DM was experimentally studied. Maximum thermal conductivity enhancement was found to be ∼7% and ∼32% respectively for 0.1–0.5 wt.% DM-CNT composites. It was observed from the crystallization kinetics study of DM that addition of CNT resulted in lowering the crystallization of DM. However after thermal cycling, the latent heat capacities decreased yet showed a high latent heat enthalpy of 241.16 kJ/kg. Experimental results showed that the total time for complete cycle reduced by ∼25.7% for 0.5 wt.% DM-CNT. The analysis of the experimental results indicate that the proposed PCM nanocomposites exhibit excellent thermal and chemical stability with enhanced heat transfer characteristics.Graphical abstractGraphical abstract for this article
       
  • Microstructural control of green bodies prepared from Si-based
           multi-component non-aqueous slurries and their effects on fabrication of
           Si3N4 ceramics through post-reaction sintering
    • Abstract: Publication date: Available online 15 September 2018Source: Advanced Powder TechnologyAuthor(s): Seitaro Morita, Motoyuki Iijima, Junichi Tatami A Si-based slurry containing Si particles covered with Y2O3 and MgO nanoparticles (NPs) has been successfully prepared and then applied to shape Si-based green compacts for the fabrication of silicon nitride (Si3N4) ceramics via post-reaction sintering. It was found that Y2O3 and MgO NPs modified with polyethyleneimine-oleic acid (PEI-OA) complex could be effectively attached to Si particles by simple mixing in dense toluene slurry. Field emission scanning electron microscopy observations confirmed the attachment of PEI-OA-modified sintering aids to Si particles without forming large NP agglomerates. The adsorption of the PEI-OA-modified sintering aids and PEI-OA on the surface of Si particles drastically improved the stability of the Si-based toluene slurry, which was subsequently molded through wet vacuum casting and dewaxed to fabricate a Si-based green body. The obtained green body was nitrided at 1375 °C for 4 h at a N2 pressure of 0.15 MPa and further sintered at 1850 °C for 2 h at a N2 pressure of 0.9 MPa. The adsorption of sintering aid particles on the Si surface reduced the number of contact points between Si particles in the green body, which effectively suppressed the Si melting process during nitriding and improved the characteristics of the produced nitride body such as the degree of nitriding and α/(α+β) ratio of Si3N4, leading to the successful fabrication of high-density Si3N4 ceramics during the subsequent densification step.Graphical abstractGraphical abstract for this article
       
  • Preparation of silver coated nickel particles by thermal plasma with
           pre-treatment using ball milling
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Dong-Wook Kim, Tae-Hee Kim, Dong-Wha Park Recently, reducing noble metals in electric devices has been identified as a key factor to lower product cost. Among these, noble metal coated particles are considered an alternative with the potential to dramatically reduce the usage of noble metals. A dense coating of noble metals over all surfaces is desirable for maintaining the properties of noble metal. However, our previous research showed that coated surfaces onto which the nanoparticles were attached were non-uniform because of evaporation of the raw materials. Therefore, in this study, we improved the coverage ratio of silver coated nickel particles using thermal plasma processing followed by ball mill pre-treatment. Silver and nickel particles were mixed using a ball mill, then injected into the thermal plasma jet. The silver particles were subsequently attached onto the surface of the nickel particles through ball mill processing, after which the silver attached nickel particles were melted through thermal plasma processing to produce silver coated nickel spherical particles. The cross section of the as-prepared particles showed a dense silver shell and nickel core, while the sintered body of the as-prepared particles showed the net-like silver covering over the nickel cores. These findings suggest that attachment of silver on nickel could lead to complete silver coatings by limiting the formation of nanoparticles.Graphical abstractGraphical abstract for this article
       
  • Facile synthesis of Ag/AgX (X = Cl, Br) with enhanced
           visible-light-induced photocatalytic activity by ultrasonic spray
           pyrolysis method
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Shuai Mao, Rui Bao, Dong Fang, Jianhong Yi Ag/AgX (X = Cl, Br) plasmonic photocatalysts were synthesized via a facile one-pot ultrasonic spray pyrolysis method, wherein no additional issues such as high pressure, surfactants and reducing agents were required. The structure, morphology, and optical property of the as-prepared photocatalysts was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet–visible light absorption spectra and total organic carbon (TOC). The results showed that Ag/AgX photocatalysts have excellent photocatalytic performance for the photodegradation of methyl orange (MO) and methylene blue (MB) pollutants under visible light illumination, and the photocatalytic activity maintains a high level after seven cycles. Metallic Ag0 particles nucleate on the surface of AgX uniformly through the thermal decomposition of residual AgNO3 solution, which enhanced the interaction between Ag0 and AgX. The outstanding photocatalytic activity benefits from the small size and high dispersion of Ag0 nanoparticles and the enhanced interaction between Ag0 and AgX.Graphical abstractGraphical abstract for this article
       
  • Hydrothermal synthesis of nanoplates assembled hierarchical h-WO3
           microspheres and phase evolution in preparing cubic Zr(Y)O2-doped tungsten
           powders
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Fangnao Xiao, Qiang Miao, Shizhong Wei, Wenping Liang, Xiaoman Fan, Kunming Pan, Liujie Xu Three-dimensional hierarchical h-WO3 and doping tungsten powders have recently attracted considerable attention because of their superior sensing properties and refined grains, respectively. In this article, we report a facile hydrothermal hydrogen reduction process for preparing hierarchical h-WO3 microspheres that self-assemble with nanoplates. Meanwhile, the phase evolution process and evolution mechanisms during the conversion of h-WO3 to W are systemically investigated. Results indicate that the highly homogeneous h-WO3 microspheres are uniformly covered with ultrafine ZrY2(OH)10 micelles, which fully transform into m-WO3 and cubic Zr(Y)O2 after calcination at 600 °C. Microspheres possessing different pore diameters and containing nanosized particles can be obtained by adjusting the hydrogen reduction process. These phase evolution process can provide reasonable guidance for preparing tungsten oxide with high electrochemical properties and ultrafine tungsten powders. The h-WO3 microspheres with an average size of 3 μm consist of nanoplates and the tungsten powders doped with 1.0 wt% Zr(Y)O2 have a mean particle size of approximately 1.4 μm. Comparative test results indicate that the addition of 1.0 wt% Zr(Y)O2 can promote the formation of low-degree particle agglomerates.Graphical abstractGraphical abstract for this article
       
  • Hydrothermal synthesis of NH2-UiO-66 and its application for
           adsorptive removal of dye
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Sneha N. Tambat, Priyanka K. Sane, Srinidhi Suresh, Nilesh Varadan O., Aniruddha B. Pandit, Sharad M. Sontakke In this research paper we report hydrothermal synthesis of NH2-UiO-66, a metal organic framework (MOF) with zirconium as metal and amino terephthalic acid as a linker. The synthesized MOF was characterized by XRD, FTIR, SEM and BET surface area. As a potential application in water treatment, an adsorptive removal of safranin dye was studied using the synthesized material. The effect of initial concentration and pH of the dye solution was studied on the dye adsorption capacity of the material. An optimum set of conditions resulting into maximum dye adsorption was found out. The maximum adsorption capacity of the MOF was observed to be 390 mg/g at neutral pH of the solution and at room temperature. The experimental data was fitted with Langmuir, Freundlich and Temkin adsorption isotherm models. The kinetics of adsorption was studied using pseudo first order and pseudo second order model. The dye adsorption mechanism was also attempted.Graphical abstractGraphical abstract for this article
       
  • One-pot green synthesis of magnesium oxide nanoparticles using Penicillium
           chrysogenum melanin pigment and gamma rays with antimicrobial activity
           against multidrug-resistant microbes
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Gharieb S. El-Sayyad, Farag M. Mosallam, Ahmed I. El-Batal Melanin pigment is well-known as a common photo-protective polymer, insoluble in water. It drews considerable attention for many applications in nanotechnology, and medical fields. Penicillium chrysogenum was employed for the green synthesis of melanin after optimizing the media compositions. A method has been designed that included one-step synthesis of magnesium oxide nanoparticles (MgO NPs) by fungal melanin under the influence of different doses of gamma rays. Antimicrobial activity of MgO NPs was examined against some selected highly pathogenic microbes. The fungal melanin acted simultaneously as a photo-protector of the magnesium atom, and at the same time as a stabilizer towards the uncontrolled free radical attack resulting from gamma rays. Afterwards, gamma rays forced a condensation reaction to occur at room temperature. A proposed reaction mechanism for MgO NPs synthesis was discussed. MgO NPs were characterized and structurally identified by UV–Vis., XRD, DLS, TEM and FTIR. Results obtained from DLS and XRD with TEM images determined the mean diameter as 10.28 nm. In addition, MgO NPs were found to be promising antimicrobial agents against' Enterococcus faecalis, Candida albicans, and Klebsiella pneumoniae having activity of 22.0, 20.0, and 20.0 mm ZOI, respectively. Based on the capability of MgO NPs as effective antimicrobial agents, they possess a potential role – in different applications such as biomedicine, food control, pharmaceutics, and cosmetics.Graphical abstractGraphical abstract for this article
       
  • Effect of Ag loading on activated carbon doped ZnO for bisphenol A
           degradation under visible light
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Khanitta Intarasuwan, Pongsaton Amornpitoksuk, Sumetha Suwanboon, Potchanapond Graidist, Saowanee Maungchanburi, Chamnan Randorn Silver modified activated carbon doped zinc oxide (Ag/AC-ZnO) was synthesized via a calcination-electroless deposition route. The samples were characterized by X-ray powder diffractometry, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of the Ag/AC-ZnO was evaluated for bisphenol A degradation in the presence of H2O2 under visible light irradiation. The archived results showed that the photocatalytic activity of the Ag/AC-ZnO was higher than that of AC-ZnO and pure ZnO. The cytotoxicity of the bisphenol A after photocatalysis under visible light irradiation was tested using L929 mouse fibroblast cells and the obtained results indicated that the treated bisphenol A solution exhibited no cytotoxicity against normal cells.Graphical abstractGraphical abstract for this article
       
  • Characterization of temporal and spatial distribution of bed density in
           vibrated gas-solid fluidized bed
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Yadong Zhang, Yanjiao Li, Liang Dong, Yuemin Zhao, Zhonglin Gao, Chenlong Duan, Qingxia Liu, Xuliang Yang This study uses a Φ 200 mm × 900 mm vibrated gas-solid fluidized bed (VGFB) with −0.3 + 0.074 mm magnetite powder was utilized to characterize the temporal and spatial distribution of bed density in VGFB and the influence of bubble movement on fluctuations in bed density. The results indicate that the bed density decreases with an increase in gas velocity (U) and the frequency (f) and amplitude (A) of vibration and that the bed density spatial distribution is lower in the central region but higher in the border regions. The standard deviation of the density first increases then decreases and finally tends to stabilize with an increase in apparent gas velocity. Moreover, when A = 2 mm, f = 25 Hz and U = 14 cm/s, the density distribution is 1.82–1.88 g/cm3 and the fluidization state is improved. The energy of the pressure signal increases with an increase in gas velocity and vibration amplitude. In particular, the low-frequency band of the pressure signal exhibits the highest amplitude and energy, which reveals that bubbles are the main cause of pressure fluctuation. Furthermore, the bed density decreases with an increase in bubble generation frequency, and the relationship between these follows the ExpDec 2 mathematical equation.Graphical abstractGraphical abstract for this article
       
  • Facile and green synthesis of highly dispersed cobalt oxide (Co3O4) nano
           powder: Characterization and screening of its eco-toxicity
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s): Shikha Dubey, Jay Kumar, Ashok Kumar, Yogesh Chandra Sharma A novel green synthesis of cobalt oxide (Co3O4) nanoparticles using latex of Calotropis procera via simple precipitation method at room temperature was investigated. An extensive characterization of the product was carried out using X-ray diffractometry (XRD), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and UV–Visible spectroscopy. The results of the characterization confirmed that the synthesized nanomaterial is highly dispersed. TEM analysis revealed that the nano particles are having an average size around 10 nm. The eco-toxic investigation suggested that the particles are non-toxic and safe towards the environment. This green strategy proves to be an effective, fast, simple and cost-effective approach for the synthesis of Co3O4 nanoparticles for various applications.Graphical abstractGraphical abstract for this article
       
  • Full title (Editorial Board Members)
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s):
       
  • Inside Front Cover (Aims & Scope, Editors)
    • Abstract: Publication date: November 2018Source: Advanced Powder Technology, Volume 29, Issue 11Author(s):
       
  • Numerical study on particle deposition in rough channels with different
           structure parameters of rough elements
    • Abstract: Publication date: Available online 24 August 2018Source: Advanced Powder TechnologyAuthor(s): Wenpeng Hong, Xin Wang, Jianxiang Zheng This paper presents a study of the characteristics of particle deposition in rib-roughened channels. The gas-particle flow was numerically investigated by Reynolds stress model (RSM) with the discrete particle model (DPM). The particle deposition velocity and deposition ratio at different positions were numerically investigated in a channel where the relative roughness factor, e/D, were between 0.02 and 0.1, and the ratios of rough-element spacing to its height, p/e, were between 7 and 20. It is found that the eddy structures behind the rough-elements are changed by the increase of e/D. The windward surfaces are the main deposition regions and the cavities between the rough-elements are the secondary deposition regions. e/D contributes more to the increase of particle deposition velocity than p/e.Graphical abstractGraphical abstract for this article
       
  • MP-PIC modeling of CFB risers with homogeneous and heterogeneous drag
           models
    • Abstract: Publication date: Available online 24 August 2018Source: Advanced Powder TechnologyAuthor(s): Jun Xie, Wenqi Zhong, Aibing Yu In this paper, the MP-PIC (multiphase particle-in-cell) approach is used for three-dimensional (3D) modeling of the gas-solid flows in two types of circulating fluidized bed (CFB) risers with Geldart group A and B particles by incorporating the homogeneous and heterogeneous drag force models in the MP-PIC method, respectively. First, the effects of the three important simulation parameters, namely, the grid cell number, numerical particle-parcel size and time step, are investigated. Having determined the appropriate values for the three parameters, the hydrodynamic characteristics predicted by different drag force models are rigorously analyzed. The homogeneous drag models considered are the six models, the Wen-Yu, Wenyu-Ergun, Syamlal-O’Brien, Gidaspow, HKL, and BVK models, while the four heterogeneous models considered are Sarkar and EMMS-based models (EMMS-Yang, EMMS-Matrix and EMMS-QL). For the riser 1 with the Geldart A particles, all the six homogeneous models predict extremely high solid fluxes and inconsistent void fraction distributions compared with experimental results. The heterogeneous Sarkar and EMMS-based models can effectively improve the simulation accuracy and predict a typical core-annulus flow structure. The lately-developed EMMS-QL model produces the most accurate solid flux. For the riser 2 with the Geldart B particles, both the heterogeneous and homogeneous drag force models can predict a reasonable flow structure. Further, there are no significant differences in the void fraction and velocity profiles due to the choice of a drag force model over the other. These drag force models also successfully capture the meso-scale local particle clusters. Of these drag-force models, the Wenyu-Ergun drag-forec model predicts comparatively accurate solid flux. Generally, MP-PIC combined with heterogeneous Sarkar and EMMS-based drag force models reasonably improve the simulation accuracy for the Geldart A particles, while these heterogeneous models have no superiority over the homogeneous drag models for the Geldart B particles.Graphical abstractGraphical abstract for this article
       
  • Evaluation of fundamental and functional properties of natural plant
           product powders for direct compaction based on multivariate statistical
           analysis
    • Abstract: Publication date: Available online 23 August 2018Source: Advanced Powder TechnologyAuthor(s): Zhe Li, Fei Wu, LiJie Zhao, Xiao Lin, Lan Shen, Yi Feng Direct compaction (DC) is the preferred choice for tablet manufacturing; however, its application in natural plant product (NPP) tablets is still extremely immature. In this study, NPP powders prepared by three commonly used methods were evaluated on their suitability for DC. Extensive characterizations of their physical properties were performed. Multivariate statistical analysis was utilized to explore the influence of preparation technology on the properties of NPP powders and identify the dominating factors that influence their DC properties. The results demonstrated that (i) the 27 kinds of model NPP powders selected randomly in this study could to some degree represent most NPP powders used in actual production; (ii) ∼81.5% of the NPP powders exhibited both poor compactibility and flowability, and none of the NPP powders could be compacted into tablets via DC; (iii) the physical properties of NPP powders prepared by direct pulverization were significantly different from those of extracted ones, while there were no significant differences between the water and ethylalcohol extracted ones; and (iv) the DC properties of NPP powders could be improved through controlling some physical properties (e.g., density, particle size, morphology, and texture parameters) reasonably. Overall, this study comprehensively evaluated the current status and application of NPP powders in DC, and is significant in facilitating the development and modernization of NPPs through DC.Graphical abstractGraphical abstract for this article
       
  • Dynamic two-point fluidization model for gas–solid fluidized beds
    • Abstract: Publication date: Available online 20 August 2018Source: Advanced Powder TechnologyAuthor(s): Javad Aminian, Kasra Farnagh In real fluidized beds various fluidization regimes may occur simultaneously resulting in quite distinct hydrodynamic characteristics in various regions of the bed. Classical approaches, generally, use a step drag function with a single switching point to distinguish dense and dilute regimes. In the present study, a new integrated hydrodynamic model (drag and viscosity) is developed using a smooth logistic function with two switching points dividing a fluidized bed into three dense, dilute and mixed regimes which is more in accordance with reality. Gas volume fraction at minimum fluidization velocity and particle Geldart’s group are employed to decide switching between dense and dilute drag and viscosity models. A spatiotemporal dynamic algorithm is used to implement the integrated model into the open source CFD package OpenFOAM 2.1.1. Reasonable predictions of various hydrodynamic characteristics in three different experimental data sets demonstrate wide applicability of the new integrated hydrodynamic model to any fluidization regime.Graphical abstractGraphical abstract for this article
       
  • On the kinetics of phase transformations of dried porous vaterite
           particles immersed in deionized and tap water
    • Abstract: Publication date: Available online 20 August 2018Source: Advanced Powder TechnologyAuthor(s): O. Cherkas, T. Beuvier, F. Zontone, Y. Chushkin, L. Demoulin, A. Rousseau, A. Gibaud Calcium carbonate exists in three allotropic forms: vaterite, aragonite and calcite. Metastable vaterite can be easily transformed into calcite and/or aragonite via different routes. We report how dry vaterite particles transform into aragonite and calcite when they are immersed into deionized (DI) or tap water without additives at different temperature (22, 40 and 60 °C) with and without stirring. We show that the transformation rate of vaterite into more stable crystallographic forms is influenced not only by temperature but also by stirring and water purity. Low temperature, absence of stirring and absence of ions in water significantly slows down the kinetics of transformation of vaterite. Additionally, water purity influences the nature of the allotropic phase obtained after transformation. High temperatures and deionized (DI) water favor the transformation of vaterite into single crystalline nanowires of aragonite, while tap water yields the transformation of vaterite into calcite. The absence of aragonite in tap water at high temperature can be explained by the presence of sulfate ions, which inhibit the formation of this phase. On the contrary, Mg2+ ions tend to stabilize vaterite.Graphical abstractAddition of dry vaterite particles in aqueous solution under different conditions induces its transformation into calcite and aragonite. We evidence that the stirring, the temperature and the water purity influence not only the transformation rate but also the obtained structure. In particular, it is shown that DI water, stirring and high temperature lead to the transformation of vaterite into single crystal nanowires of aragonite.Graphical abstract for this article
       
  • Development of cerium and silicon co-doped hydroxyapatite nanopowder and
           its in vitro biological studies for bone regeneration applications
    • Abstract: Publication date: Available online 18 August 2018Source: Advanced Powder TechnologyAuthor(s): B. Priyadarshini, U. Vijayalakshmi Multi-ion, co-substituted bioactive glass ceramics play a significant role in the stimulation of physical and biological properties for outstanding effects in biomedical application. The following work attempts to develop HAP as a parent material doped with a combination of cerium (Ce4+ @1.25 wt%) and silicon (Si4+ @1, 3 and 5 wt%) by refluxing based sol-gel technique. The anti-bacterial tests exhibit E. coli showing higher inhibition efficiency, in vitro hemolytic test exhibit good compatible nature of dual doped HAP with erythrocytes (
       
  • Prediction of hopper discharge rate using combined discrete element method
           and artificial neural network
    • Abstract: Publication date: Available online 17 August 2018Source: Advanced Powder TechnologyAuthor(s): Raj Kumar, Chetan M. Patel, Arun K. Jana, Srikanth R. Gopireddy An Artificial Neural Network (ANN) was developed to predict the mass discharge rate from conical hoppers. By employing Discrete Element Method (DEM), numerically simulated flow rate data from different internal angles (20°–80°) hoppers were used to train the model. Multi-component particle systems (binary and ternary) were simulated and mass discharge rate was estimated by varying different parameters such as hopper internal angle, bulk density, mean diameter, coefficient of friction (particle-particle and particle-wall) and coefficient of restitution (particle-particle and particle-wall). The training of ANN was accomplished by feed forward back propagation algorithm. For validation of ANN model, the authors carried out 22 experimental tests on different mixtures (having different mean diameter) of spherical glass beads from different angle conical hoppers (60° and 80°). It was found that mass discharge rate predicted by the developed neural network model is in a good agreement with the experimental discharge rate. Percentage error predicted by ANN model was less than ±13%. Furthermore, the developed ANN model was also compared with existing correlations and showed a good agreement.Graphical abstractGraphical abstract for this article
       
  • A systematic study on solid-state synthesis of monticellite (CaMgSiO4)
           based ceramic powders obtained from boron derivative waste
    • Abstract: Publication date: Available online 17 August 2018Source: Advanced Powder TechnologyAuthor(s): Levent Koroglu, Erhan Ayas Solid-state synthesis of monticellite based ceramic powders from boron derivative waste in an eco-friendly route and the investigation of phase transformation mechanisms were studied. The heat-treatment of boron derivative waste, mainly composed of dolomite, calcite and quartz, was systematically carried out at 650 °C and 800 °C for various dwell times between 1 min and 4 h. The heat-treatment temperatures were selected considering TG-DTA curves of waste and ΔG – T diagrams obtained using FactSage Thermochemical Software. XRF, XRD, FTIR, TG-DTA and SEM analysis, particle size measurement and crystallite size determination carried out extensively. The obtained results showed that monticellite based ceramic powder synthesized at 800 °C for 4 h was composed of monticellite, akermanite, diopside, calcium magnesium borate and zeolite. The calcination of dolomite was completed both at 650 °C for 1 h and up to 800 °C, and calcite was decomposed at 800 °C for 30 min. Both diopside and monticellite were firstly detected at 650 °C for 30 min and at 800 °C for 1 min. Also, akermanite was presented at 800 °C for 1 min. The presented method offers the lowest temperature (800 °C) in literature for synthesis of monticellite and akermanite which reduces the energy consumption during heat-treatment.Graphical abstractGraphical abstract for this article
       
  • Silo quake response spectrum of iron ore train load out bin
    • Abstract: Publication date: Available online 14 August 2018Source: Advanced Powder TechnologyAuthor(s): Phung Tu, Vanissorn Vimonsatit, Jun Li Silo quaking is a very complex industrial phenomenon and is often occurred in silo structures during discharge. There are three variants of the silo quaking phenomenon such as silo honking, silo shock and silo pulsation. Accelerometers are often used in practice to measure the responses of the structure. The accelerations generated by the silo structure during discharge are of non-linear and non-stationary nature. Therefore traditional algorithm, such as Fast Fourier Transform, which was designed to analyse linear and stationary signals and often used to analyse the collected acceleration data, is not suitable for signals generated by the silo structure during discharge. In the present research, Hilbert-Huang Transform and Hilbert Marginal Spectrum created by Norden Huang, a mathematician at NASA to analyse non-linear and non-stationary signals, were used to analyse the accelerograms collected from the experimental silo. The results revealed the existence of a silo quake spectrum which lays a solid foundation for further research into the silo quaking phenomenon and especially structural design methods to mitigate the effects of silo quaking on the silo structure.Graphical abstractGraphical abstract for this article
       
  • Controlled construction of uniform pompon-like Pb-ICP microarchitectures
           as a precursor for PbO semiconductor nanoflakes
    • Abstract: Publication date: Available online 13 August 2018Source: Advanced Powder TechnologyAuthor(s): Maryam Mohammadikish, Kosar Zamani Three-dimensional hierarchical Pb-infinite coordination polymer (Pb-ICP) pompon-like microstructures with high degree of uniformity were prepared from Pb2+ ions and bi-carboxylic acid organic linker by precipitation and hydrothermal methods. Our bottom-up process revealed the direct assembly of nanosheets with 70 nm thickness to give pompon-like structure without the addition of any surfactants. Reaction parameters are critical to size and shape control and structural uniformity of the Pb-ICP nanostructures. The morphology could be tuned by adjusting the time and the reaction procedures. Based on the result of a series of comparative experiments, it was concluded that the possible formation mechanism of the pompon-like microspheres is through the intertwined nanosheets self-assembly. Photoluminescence spectroscopy shows the quenching of emission peaks of the bi-carboxylic acid linker after coordination to Pb2+ ion. Ligand-free PbO nanoflakes with a mean diameter of 40 nm were simply obtained by calcination of pompon-like Pb-ICP at 500 °C for 2 h under static air. The well crystallized PbO nanoflakes exhibit large band gap due to quantum confinement effect.Graphical abstractLead based infinite coordination polymer, Pb-ICP, with pompon-like, cauliflower and intertwined rods was readily prepared by precipitation and hydrothermal methods. Ligand-free PbO nanoflakes with a high bandgap were simply obtained by calcination of pompon-like Pb-ICP.Graphical abstract for this article
       
  • Studies on structural, magnetic, and DC electrical resistivity properties
           of Co0.5M0.37Cu0.13Fe2O4 (M = Ni, Zn and Mg) ferrite nanoparticle
           systems
    • Abstract: Publication date: Available online 12 August 2018Source: Advanced Powder TechnologyAuthor(s): A. Ramakrishna, N. Murali, S.J. Margarette, Tulu Wegayehu Mammo, N. Krishna Joythi, B. Sailaja, Ch.C. Sailaja Kumari, K. Samatha, V. Veeraiah Ferrite nanoparticles of the composition Co0.5M0.37Cu0.13Fe2O4 (M = Ni, Zn, and Mg) have been synthesized using sol-gel auto combustion method. Structural properties are investigated using powder X-ray diffraction technique and the results showed a pure spinel crystal structures of the synthesized materials with lattice parameters in the range of 8.3331–8.4793 Å. Crystallite sizes are calculated using the Scherrer’s formula and the results are found to be in the range of 62.22–82.41 nm. The surface texture and morphological nature of the samples are studied by scanning electron microscopy which depicted clear crystalline nature of the materials. Characteristic vibrational states prevailing in the samples are studied using room temperature Fourier transform infrared spectroscopy. A two-probe DC electrical resistivity measurement of the samples showed a high resistive nature. Room temperature vibrating sample magnetometer measurements revealed the magnetic properties of the samples.Graphical abstractPowder X-ray diffraction patterns of Co0.5M0.37Cu0.13Fe2O4 (M = Ni, Zn, and Mg) ferrite nanoparticles.Graphical abstract for this article
       
  • Numerical and experimental studies on nozzle two-phase flow
           characteristics of nanometer-scale iron powder metal fuel motor
    • Abstract: Publication date: Available online 11 August 2018Source: Advanced Powder TechnologyAuthor(s): Jin-yun Wang, Zai-lin Yang, Meng-jun Wang Metal iron powder is a promising new type of energy source that is of enormous practical and research interest for future automotive power systems. To better optimize engine design, this study was devoted to the characteristic investigation of a two-phase flow. Experimental studies involving nanometer iron powder particle combustion and engine thrust measurement were conducted to confirm the results obtained from numerical calculations that were performed using a fourth-order Runge–Kutta–Gill method. Governing equations for nozzle two-phase flow were established to perform a theoretical study to analyze the combustion properties of iron oxide particles and flow in the nozzle. The results indicate that variations in the size and coagulation content of particles play a significant role in the loss of two-phase flow. Significant emphasis was placed on the effect of particle size (0.4–1.0 μm) and condensate content (10–40%) of ultrafine particles on the specific impulse. To further validate the theoretical results, the burning rates of particles of three different sizes were experimentally measured. In addition, the motor thrust and the specific impulse with the particle size of 50 nm were tested through combustion experiment, and the results show excellent agreement.Graphical abstractGraphical abstract for this article
       
  • Structural and mechanical characterization of lithium-ion battery
           electrodes via DEM simulations
    • Abstract: Publication date: October 2018Source: Advanced Powder Technology, Volume 29, Issue 10Author(s): Clara Sangrós Giménez, Benedikt Finke, Christine Nowak, Carsten Schilde, Arno Kwade Electrode structural stability and mechanical integrity is of major importance regarding not only lithium-ion battery performance but also safety aspects. The goal of this study is to design a simulation procedure to reproduce the microstructural and mechanical properties of such lithium-ion battery electrodes. Taking into consideration the particulate state of these electrodes, a discrete element method (DEM) approach is proposed, which comprises a procedure to reproduce real electrode structures and the application of a proper contact model to capture the bulk mechanics. This is accomplished by considering particle interactions as well as the performance of the binder. Three different electrodes are manufactured with the aim of calibrating and validating the Hertzian-bond contact model. Experimental nanoindentation measurements prove to be in good agreement with the simulation outcome, concluding that the method constitutes a valuable physical and mechanical basis for further applications.Graphical abstractGraphical abstract for this article
       
  • Titanium glycolate-derived TiO2 nanomaterials: Synthesis and
           applications
    • Abstract: Publication date: October 2018Source: Advanced Powder Technology, Volume 29, Issue 10Author(s): Yi Wei, Jiaxin Zhu, Yixin Gan, Gang Cheng Titanium oxide (TiO2) is one of the most widely studied materials due to its fascinating properties and versatile applications in environmental and energy fields ranging from photocatalysis to solar cells and lithium ion batteries. The significance and variety of these applications have attracted great attention and spurred substantial progress in the synthesis and fundamental understanding of TiO2-based nanomaterials, nanocomposites, and nanoderivatives. This review summarizes the recent advances in the design and preparation of TiO2-based nanomaterials, nanocomposites, and nanoderivatives obtained from titanium glycolate precursor. Utilizing different fabrication strategies, titanium glycolate precursor with controllable morphology and size has been successfully produced, and it can be directly transformed into crystalline TiO2 nanomaterials through diverse post-treatments, including calcination thermal-decomposition, and refluxing, hydrothermal, and microwave treatment-assisted hydrolysis. Furthermore, doped TiO2, TiO2-composites, and other derivatives could be simply achieved by adding additional chemicals during transformation. The favorable properties of the resulting TiO2-based materials are also discussed, which are relevant to energy and environmental applications in the areas of dye-sensitized solar cells, lithium ion batteries, photocatalytic hydrogen evolution, photocatalytic CO2 reduction, photocatalytic degradation, and adsorption removal of pollutants.Graphical abstractGraphical abstract for this article
       
  • Full title (Editorial Board Members)
    • Abstract: Publication date: October 2018Source: Advanced Powder Technology, Volume 29, Issue 10Author(s):
       
  • Inside Front Cover (Aims & Scope, Editors)
    • Abstract: Publication date: October 2018Source: Advanced Powder Technology, Volume 29, Issue 10Author(s):
       
  • La0.6Sr0.4Co0.2Fe0.79M0.01O3−δ (M = Ni, Pd) perovskites synthesized
           by Citrate-EDTA method: Oxygen vacancies effect on electrochemical
           properties
    • Abstract: Publication date: Available online 10 August 2018Source: Advanced Powder TechnologyAuthor(s): Shaoli Guo, Fabrizio Puleo, Liuding Wang, Hongjing Wu, Leonarda F. Liotta La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF08), La0.6Sr0.4Co0.2Fe0.79Ni0.01O3−δ (LSCF08-Ni) and La0.6Sr0.4Co0.2Fe0.79Pd0.01O3−δ (LSCF08-Pd) perovskites were synthesized by Citrate-EDTA method, by using NiCl2 or PdCl2 as metal precursors, and their physicochemical properties were characterized by XRD, TGA, TPD and TPR. XRD data evidenced an expansion of the lattice parameters of LSCF08-Pd, while a contraction of the lattice occurred for LSCF08-Ni, with respect to the undoped LSCF, suggesting different oxygen vacancies content in the perovskite (confirmed by TGA) likely due to a different oxidation state of Ni and Pd species stabilized in the structure.TEM analyses performed over LSCF08-Pd revealed the presence of metallic Pd nanoparticles well dispersed in the matrix that accounts for the increased reducibility of the Co and Fe species with respect to LSCF08-Ni and undoped perovskite. AC impedance measurements that were carried out on symmetric cells consisting of LSCF-based materials deposited onto Ce0.8Gd0.2O2−δ (GDC) electrolyte proved the enhanced electrochemical performances of Ni/Pd doped LSCF.The electrochemical characterization of LSCF08, LSCF08-Ni and LSCF08-Pd electrodes was completed by performing cyclic voltammetry experiments in the range of temperature 600–800 °C, varying the potential (U) between 0.3 V and −1 V, at scan rates in the range 1–50 mV s−1 and working under flow of 0.7 vol% O2 in He (30 ml/min).Graphical abstractGraphical abstract for this article
       
  • Numerical study of nanofluid thermo-bioconvection containing gravitactic
           microorganisms in porous media: Effect of vertical throughflow
    • Abstract: Publication date: Available online 7 August 2018Source: Advanced Powder TechnologyAuthor(s): Shivani Saini, Y.D. Sharma An analytical investigation of the onset of nanofluid thermo-bioconvection in a fluid saturated by porous media containing gravitactic and nanoparticles microorganisms subjected to a vertical throughflow is presented. The heat conservation equation is formulated by introducing the convective term of nanoparticle flux. The fluid is stimulated with modified Brinkman model, normal mode analysis and six-term Galerkin methods are used to solve the governing equations. The combined effects of vertical throughflow, nanoparticles, gravitactic microorganisms, and porosity have been taken into account. The effects of bioconvection Rayleigh number, bioconvection Péclet number, nanoparticle Rayleigh number, Péclet number, bioconvection Lewis number, and porosity on critical thermal Rayleigh number have been examined. The analysis leads that critical wave number is the function of bioconvection parameters, nanofluid parameters and throughflow parameters. It is also found that vertical throughflow disturbs the formation of bioconvection pattern which are necessary for the development of bioconvection.Graphical abstractGraphical abstract for this article
       
  • A template-free method to synthesize porous G-C3N4 with efficient visible
           light photodegradation of organic pollutants in water
    • Abstract: Publication date: Available online 4 August 2018Source: Advanced Powder TechnologyAuthor(s): Elham Boorboor Azimi, Alireza Badiei, Moayad Hossaini Sadr, Ahmad Amiri Porous graphitic carbon nitride with a high surface area was successfully synthesized without using any template or other substances like metals, just by placing melamine powder into a muffle furnace which was heated to 550 °C in advance. To evaluate the structure, morphology, and optical properties, the high performance g-C3N4 (HPCN) was analyzed by XRD, SEM-EDX, TEM, N2 physisorption, FT-IR analysis, UV–Vis DRS, PL, and Zeta potential. HPCN was able to completely degrade rhodamine B under visible light with the rate constant of 0.086 min−1, which is 3.5 times higher than the traditional g-C3N4. The possible mechanism of RhB photodegradation was discussed in detail, which illustrated the reaction is performed in acidic media much better than neutral and basic solutions, and O2− and h+ are the key reactive species during the reaction. Moreover, the stability of the photocatalyst was investigated and turned out its photocatalytic activity has not considerably changed after 6 cycles, so it was a highly stable photocatalyst.Graphical abstractGraphical abstract for this article
       
  • Verification of optimal models for 2D-full loop simulation of circulating
           fluidized bed
    • Abstract: Publication date: Available online 4 August 2018Source: Advanced Powder TechnologyAuthor(s): Yujian Lu, Yefeng Zhou, Lei Yang, Xiayi Hu, Xiao Luo, Hongbo Chen To verify the optimal models for a two-dimensional (2D) full loop simulation of a circulating fluidized bed (CFB), different turbulent models and drag models are studied according to relevant pressure profile, voidage distribution and particle collision energy. With regard to a laminar model and turbulent models including Standard k-ε, RNG k-ε and Realizable k-ε, the experimental data reveals that the RNG k-ε model is the best at predicting pressure, voidage, axial solid velocity and granular temperature. Besides, through the comparison of four drag models, it is found that the Gidaspow model can achieve a higher accuracy of prediction. Therefore, it can be concluded that the combination of the RNG and Gidaspaw models is suitable for the 2D full loop simulation of a CFB, and therefore potential models for the prediction of flow characteristics.Graphical abstractIn this work, different turbulent models and drag models were compared in order to obtain the optimal simulation models. In addition, experimental data, obtained by measurement of pressure transducer and acoustic emission, were used to validate the accuracy of the models.Graphical abstract for this article
       
  • Flow of granular materials in a bladed mixer: Effect of particle
           properties and process parameters on impeller torque and power consumption
           
    • Abstract: Publication date: Available online 2 August 2018Source: Advanced Powder TechnologyAuthor(s): Veerakiet Boonkanokwong, Rohan P. Frank, Pavithra Valliappan, Brenda Remy, Johannes G. Khinast, Benjamin J. Glasser The torque and power needed to drive an impeller are important quantities that can indicate flow behavior and can be used to control processes, especially mixing and granulation in the pharmaceutical industry. In this study, experiments were conducted on monodisperse spherical glass beads flowing in a cylindrical bladed mixer agitated by an impeller. The impeller torque was measured using a rotating platform and a data recording device, and the power draw for the motor driving the impeller was measured using a power meter. The effect of various impeller blade designs and material properties on the torque and power were investigated as a function of the impeller blade rotation rate. It was found that the torque exerted on a granular bed and the power consumption were a strong function of the impeller blade configuration, the position of the blades in a deep granular bed, the fill height of the glass beads, and the size and friction coefficient of the particles. It was observed that the time-averaged torque and power consumption for different particle sizes qualitatively scaled with particle diameter. A scale-up relationship for a deep granular bed was developed: the time-averaged torque and average adjusted power consumption scaled with square of the material fill height.Graphical abstractGraphical abstract for this article
       
  • Iron-based magnetic nanoparticles for magnetic resonance imaging
    • Abstract: Publication date: Available online 2 August 2018Source: Advanced Powder TechnologyAuthor(s): Hira Fatima, Kyo-Seon Kim Magnetic resonance imaging (MRI) has been an extensive area of research owing to its depth of penetration for clinical diagnosis. Signal intensity under MRI is related to both T1, spin-lattice relaxation, and T2, spin-spin relaxation. To increase the contrast variability under MRI, several contrast agents are being used, i.e. T1 contrast agents (e.g. gadolinium) and T2 contrast agents (e.g. iron-based magnetic nanoparticles). These contrast agents are administered prior to scanning to increase contrast visibility. They reduce the T1 and T2 relaxation times to produce hyperintense and hypointense signals, respectively. Tunable properties of iron-based magnetic nanoparticles and several coating materials provide a platform to get superb MRI contrast in T2 weighted images. It has been found that contrast enhancement by iron-based magnetic nanoparticles is dependent on the size, shape, composition, surface, and magnetic properties which can be tuned with the synthesis method and coating material. Therefore, understanding the synthesis method and properties of magnetic nanoparticles is vital to contribute to MR signal enhancement which is directing the scientist to design engineered iron-based magnetic nanoparticles. This paper introduces the concept of MRI contrast enhancement. We mainly discuss the synthesis of T2 contrast agents, i.e. iron-based magnetic nanoparticles and the modification of these T2 contrast agents by coating followed by their biomedical applications.Graphical abstractGraphical abstract for this article
       
  • Mixing assessment of non-cohesive particles in a paddle mixer through
           experiments and discrete element method (DEM)
    • Abstract: Publication date: Available online 2 August 2018Source: Advanced Powder TechnologyAuthor(s): Amirsalar Yaraghi, Mohammadreza Ebrahimi, Farhad Ein-Mozaffari, Ali Lohi In this study the mixing kinetics and flow patterns of non-cohesive, monodisperse, spherical particles in a horizontal paddle blender were investigated using experiments, statistical analysis and discrete element method (DEM). EDEM 2.7 commercial software was used as the DEM solver. The experiment and simulation results were found to be in a good agreement. The calibrated DEM model was then utilized to examine the effects of the impeller rotational speed, vessel fill level and particle loading arrangement on the overall mixing quality quantified by the relative standard deviation (RSD) mixing index. The simulation results revealed as the impeller rotational speed was increased from 10 RPM to 40 RPM, generally a better degree of mixing was reached for all particle loading arrangements and vessel fill levels. As the impeller rotational speed was increased further from 40 RPM to 70 RPM the mixing quality was affected, for a vessel fill level of 60% and irrespective of the particle loading arrangement. Increasing the vessel fill level from 40% to 60% enhanced the mixing performance when impeller rotational speed of 40 RPM and 70 RPM were used. However, the mixing quality was independent of vessel fill level for almost all simulation cases when 10 RPM was applied, regardless of the particle loading arrangement. Furthermore, it was concluded that the particle loading arrangement did not have a considerable effect on the mixing index. ANOVA showed that impeller rotational speed had the strongest influence on the mixing quality, followed by the quadratic effect of impeller rotational speed, and lastly the vessel fill level. The granular temperature data indicated that increasing the impeller rotational speed from 10 RPM to 70 RPM resulted in higher granular temperature values. By evaluating the diffusivity coefficient and Peclet number, it was concluded that the dominant mixing mechanism in the current mixing system was diffusion.Graphical abstractGraphical abstract for this article
       
  • Two-phase lattice Boltzmann simulation of natural convection in a Cu-water
           nanofluid-filled porous cavity: Effects of thermal boundary conditions on
           heat transfer and entropy generation
    • Abstract: Publication date: Available online 2 August 2018Source: Advanced Powder TechnologyAuthor(s): Dhrubajyoti Kashyap, Anoop K. Dass The present work investigates the effect of four different thermal boundary conditions on natural convection in a fluid-saturated square porous cavity to make a judicious choice of optimal boundary condition on the basis of entropy generation, heat transfer and degree of temperature uniformity. Four different heating conditions- uniform, sinusoidal and two different linear temperature distributions are applied on the left vertical wall of the cavity respectively while maintaining the right vertical wall uniformly cooled and the horizontal walls thermally insulated. The two-phase thermal lattice Boltzmann (TLBM) model for nanofluid is extended to simulate nanofluid flow through a porous medium by incorporating the Brinkman–Forchheimer-extended Darcy model. The close agreement between present LBM solutions with the existing published results lends validity to the present findings. The current results indicate that the uniform and bottom to top linear heating are found to be efficient heating strategies depending on Rayleigh number (103 ≤ Ra ≤ 105) and Darcy number (10−1 ≤ Da ≤ 10−6). It is observed that the nanofluid improves the energy efficiency by reducing the total entropy generation and enhancing the heat transfer rate although its augmentation depends on the optimal volume fraction of nanoparticles.Graphical abstractGraphical abstract for this article
       
  • Evaluation of single-phase, discrete, mixture and combined model of
           discrete and mixture phases in predicting nanofluid heat transfer
           characteristics for laminar and turbulent flow regimes
    • Abstract: Publication date: Available online 1 August 2018Source: Advanced Powder TechnologyAuthor(s): E.J. Onyiriuka, A.I. Obanor, M. Mahdavi, D.R.E. Ewim It is essential to investigate the appropriate model for simulating nanofluid flow for different flow regimes because, at present, most previous studies do not agree with each other. It was, therefore, the purpose of this study to present a Computational Fluids Dynamics (CFD) investigation of heat transfer coefficients of internal forced convective flow of nanofluids in a circular tube subject to constant wall heat flux boundary conditions. A complete three-dimensional (3D) cylindrical geometry was used. Laminar and turbulent flow regimes were considered. Three two-phase models (mixture model, discrete phase model (DPM) and the combined model of discrete and mixture phases) and the single-phase homogeneous model (SPM) were considered with both constant and variable properties. For the turbulent flow regime, it was found that the DPM with variable properties closely predicted the local heat transfer coefficients with an average deviation of 9%, and the SPM deviated from the DPM model by 2%. It was also found that the mixture and the combined discrete and the mixture phase model gave unrealistic results. For laminar flow, the DPM model with variable properties predicted the heat transfer coefficients with an average deviation of 9%.Graphical abstractGraphical abstract for this article
       
  • Numerical investigation of influence of treatment of the coke component on
           hydrodynamic and catalytic cracking reactions in an industrial riser
    • Abstract: Publication date: Available online 31 July 2018Source: Advanced Powder TechnologyAuthor(s): D.C. Pelissari, H.C. Alvares-Castro, J.L.G. Vergel, M. Mori A three dimensional gas-solid reactive flow model based on the Eulerian-Eulerian approach was used to simulate the hydrodynamic, heat transfer and catalytic cracking reaction within in a conventional Fluid Catalytic cracking (FCC) riser. A 12-lump kinetic model was used to represent the catalytic cracking reaction network. It was proposed a catalyst deactivation model as a function of the weight percentage of coke amount on the catalyst to replace the deactivation model dependent of the residence time. It was compared the effects of novel treatment for coke component (coke produced in the solid phase) with common treatment (coke produced in the gas phase) on the fluid dynamic and catalytic cracking. The results showed that the treatment for coke component affects radial distribution of coke mass flow. It also showed that the treatment for coke plays an important role in simulation with catalyst deactivation as a function of coke amount on catalyst.Graphical abstractGraphical abstract for this article
       
  • The impact of vertical internals array on the key hydrodynamic parameters
           in a gas-solid fluidized bed using an advance optical fiber probe
    • Abstract: Publication date: Available online 25 July 2018Source: Advanced Powder TechnologyAuthor(s): Haidar Taofeeq, Muthanna Al-Dahhan The effect of a circular configuration of intense vertical immersed tubes on the hydrodynamic parameters has been investigated in a gas-solid fluidized bed of 0.14 m inside diameter. The experiments were performed using glass beads solid particles of 365 μm average particle size, with a solid density of 2500 kg/m3 (Geldart B). An advanced optical fiber probe technique was used to study the behavior of six essential local hydrodynamic parameters (i.e., local solids holdup, particles velocity, bubble rise velocity, bubble frequency, and bubble mean chord length) in the presence of vertical immersed tubes. The experimental measurements were carried out at six radial positions and three axial heights, which represent the three key zones of the bed: near the distributor plate, the middle of the fluidizing bed, and near the freeboard of the column. Furthermore, four superficial gas velocities (u/umf = 1.6, 1.76, 1.96, and 2.14) were employed to study the effect of operating conditions. The experimental results demonstrated that the vertical internals had a significant effect on all the studied local hydrodynamic characteristics such that when using internals, both the solids holdup and bubble mean chord length decreased, while the particles velocity, bubble rise velocity, and bubble frequency increased. The measured values of averaged bubble rise velocities and averaged bubble chord lengths at different axial heights and superficial gas velocities have been compared with most used correlations available in the literature. It was found that the measured values are in good agreement with values calculated using predicted correlation for the case without vertical internals. While, the absolute percentage relative error between the measured and calculated values of these two hydrodynamic parameters indicate large differences for the case of vertical internals.Graphical abstractGraphical abstract for this article
       
  • Optimum milling parameters for production of highly uniform metal-matrix
           nanocomposites with improved mechanical properties
    • Abstract: Publication date: Available online 20 July 2018Source: Advanced Powder TechnologyAuthor(s): A. Wagih, A. Fathy, A.M. Kabeel In the present paper, a system dynamic model is presented to predict the final particle size of milled powder during ball milling process. The presented model is used to obtain the optimum ball size, milling speed and milling time that achieve the best particle size reduction of metal-matrix nanocomposites. Parametric study is performed using the presented analytical model to study the influence of ball size and milling speed on the milling efficiency. The predictions of the presented model are validated with experimental results done during this work for Cu-5%ZrO2 nanocomposite and others available in the literature. The results show that the milling time required to achieve the steady state condition for Cu-5%ZrO2 nanocomposite is 15 h. At 15 h of milling, ZrO2 particles are highly uniform distributed in Cu matrix and the microhardness is increased from 75.4 HV for Cu to 197.6 HV for Cu-5%ZrO2 nanocomposite. After 15 h, the particle size reduction rate is too low and the hardness improvement rate is too low as well (204.1 HV after 20 h milling) which make the milling process after 15 h is not appreciable.Graphical abstractGraphical abstract for this article
       
  • The synthesis of a porous-type of TiO2 with rutile structure
    • Abstract: Publication date: Available online 17 July 2018Source: Advanced Powder TechnologyAuthor(s): Yukiya Yamashita, Kei Ishiguro, Daisuke Nakai, Masayoshi Fuji The synthesis of a porous-type of TiO2 with rutile structure was studied. The focuses were on the thermal treatment temperature and time. AEROXIDE® TiO2 P 25, as a fumed TiO2, was thermally treated in a vertical-type tubular furnace by the natural dropping method. Even though the thermal treatment time was less than 1 s, a drastic increase of polymorphism from anatase structure to rutile structure was observed. The relationships between the rutile structure transformation ratio and surface area of obtained porous type of TiO2 were investigated depending on the thermal treatment temperature. The porous-type of fumed TiO2 showed high dispersibility in the sedimentation test although is showed large particle size.Graphical abstractGraphical abstract for this article
       
  • Synthesis of highly crystalline hexagonal cesium tungsten bronze
           nanoparticles by flame-assisted spray pyrolysis
    • Abstract: Publication date: Available online 14 July 2018Source: Advanced Powder TechnologyAuthor(s): Tomoyuki Hirano, Shuhei Nakakura, Febrigia Ghana Rinaldi, Eishi Tanabe, Wei-Ning Wang, Takashi Ogi Highly crystalline and hexagonal single-phase cesium tungsten bronze (Cs0.32WO3) nanoparticles were successfully synthesized by a flame-assisted spray pyrolysis followed by annealing under a reducing gas atmosphere. The resulting Cs0.32WO3 nanoparticles featured a pure hexagonal Cs0.32WO3 phase with a high crystallinity and homogeneous chemical composition. Unlike conventional methods, the proposed process in this paper has several advantages, including a short reaction time and the ability to yield products with high purity and good energy efficiency. Furthermore, the Cs0.32WO3 nanoparticles produced in this research showed a remarkable near-infrared shielding ability with a 97.7% cut-off at 1500 nm.Graphical abstractGraphical abstract for this article
       
  • Heulandite/polyaniline hybrid composite for efficient removal of acidic
           
    • Abstract: Publication date: Available online 12 July 2018Source: Advanced Powder TechnologyAuthor(s): Mostafa R. Abukhadra, Mohamed Rabia, Mohamed Shaban, Francis Verpoort Heulandite/polyaniline (HU/PANI) composite was prepared by mechanical mixing from natural heulandite and synthesized polyaniline. HU/PANI was characterized by XRD, SEM, TEM, FT-IR, and UV–Vis spectroscopy. The product is of polycrystalline nature with an average crystallite size of 25.7 nm and optical band gap of 1.69 eV. HU/PANI shows higher efficiency in the removal of light green SF dye than natural HU or PANI in the dark and under artificial illumination. The equilibrium time was attained after 360 and 480 min in the dark and under illumination, respectively. The results fitted well with pseudo second order and Elovich kinetic models. The adsorption isotherm in the dark fitted well with Langmuir isotherm model and the calculated qmax was 44.6 mg/g. Using illumination, the data fitted better with the Freundlich and Temkin model than with the Langmuir model. Based on response surface analysis, the predicted conditions for maximum removal of light green SF dye in the dark (70.9%) were 5.5 mg/L, 24 mg, 3, and 430 min for dye concentration, HU/PANI dose, pH, and contact time, respectively. Whereas, under light illumination (97%) at operating conditions of 15 mg/L, 15 mg, 3, and 589 min, respectively. The composite also shows high efficiencies in the removal of other types of acidic and basic dyes.Graphical abstractGraphical abstract for this article
       
  • Large-scale GPU based DEM modeling of mixing using irregularly shaped
           particles
    • Abstract: Publication date: Available online 11 July 2018Source: Advanced Powder TechnologyAuthor(s): Nicolin Govender, Daniel N. Wilke, Chuan-Yu Wu, Raj Rajamani, Johannes Khinast, Benjamin J. Glasser Mixing of particulate systems is an important process to achieve uniformity, in particular pharmaceutical processes that requires the same amount of active ingredient per tablet. Several mixing processes exist, this study is concerned with mechanical mixing of crystalline particles using a four-blade mixer. Although numerical investigations of mixing using four-blades have been conducted, the simplification of particle shape to spherical or rounded superquadric particle systems is universal across these studies. Consequently, we quantify the effect of particle shape, that include round shapes and sharp edged polyhedral shapes, on the mixing kinematics (Lacey Mixing Index bounded by 0 and 1) that include radial and axial mixing as well as the inter-particle force chain network in a numerical study. We consider six 100 000 particles systems that include spheres, cubes, scaled hexagonal prism, bilunabirotunda, truncated tetrahedra, and a mixed particle system. This is in addition to two six million particle systems consisting of sphere and truncated tetrahedra particles that we can simulate within a realistic time frame due to GPU computing. We found that spherical particles mixed the fastest with Lacey mixing indices of up to 0.9, while polyhedral shaped particle systems mixing indexes varied between 0.65 and 0.87, for the same mixing times. In general, to obtain a similar mixing index (of 0.7), polyhedral shaped particle systems needed to be mixed for 50% longer than a spherical particle system which is concerning given the predominant use of spherical particles in mixing studies.Graphical abstractGraphical abstract for this article
       
  • A novel route to prepare the metastable vaterite phase of CaCO3 from CaCl2
           ethanol solution and Na2CO3 aqueous solution
    • Abstract: Publication date: Available online 7 July 2018Source: Advanced Powder TechnologyAuthor(s): Jiuxin Jiang, Yue Wu, Chuanjie Chen, Xuelian Wang, Huakang Zhao, Songsong Xu, CanCan Yang, Bowen Xiao Vaterite, the least stable phase among three anhydrous polymorphs of calcium carbonate (CaCO3), was prepared via the reaction between the ethanol solution of calcium chloride (CaCl2) and the aqueous solution of sodium carbonate (Na2CO3), which is named ethanol-calcium method. The effects of aging times and reaction temperatures on the formation of vaterite were investigated. The polymorphs and morphologies were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, and Fourier transform infrared spectroscopy (FT-IR) was used to verify the existence of vaterite. XRD results indicate that the amount of vaterite decreases from 90.4% to 81.4% as increasing in aging times from 0 min to 42 h and decreases from 85.8% to 70.2% as increasing in reaction temperatures from 0 °C to 60 °C. SEM results show that vaterite and calcite as-prepared are their typical morphologies of spherical and rhombohedral, respectively. This research extends the route to prepare the metastable vaterite and provides new insights into its controllable synthesis.Graphical abstractComplexation between CaCl2 and ethanol occurs when CaCl2 powder is added in anhydrous ethanol. The complex CaCl2·nC2H5OH (n = 4 or 6, taking n = 6 as an example) distributes homogeneously in anhydrous ethanol, forming a transparent solution. Based on the fact that the system becomes turbid as soon as the addition of transparent Na2CO3 aqueous solution, it can be concluded that the decomplexation of CaCl2·6C2H5OH, the ionization of CaCl2 in water and the combination of Ca2+ and CO32− occur instantaneously and in sequence. According to previous research, amorphous calcium carbonate (ACC) nucleates firstly, followed by crystallization in different polymorphs, or crystallization as metastable vaterite phase and then transformation to the most stable calcite phase.Graphical abstract for this article
       
  • Highly efficient degradation of 2-chlorophenol and methylene blue with
           Rb0.27WO3/NiFe-CLDH composites under visible light irradiation
    • Abstract: Publication date: Available online 7 July 2018Source: Advanced Powder TechnologyAuthor(s): Guoqing Zhao, Dan Zhang, Yaliang Huang, Jingang Yu, Xinyu Jiang, Feipeng Jiao Novel magnetically composites photocatalyst Rb0.27WO3/NiFe-CLDH (RWCLDH) was fabricated via a simple method. The as-prepared catalysts were characterized using XRD, XPS, SEM, TEM, HRTEM, BET, UV–Vis DRS spectra and PL analysis. The RWCLDH-700 composites exhibit a two-fold enhancement in photocatalytic activity toward degradation of 2-chlorophenol (2-CP) and Methylene blue (MB) under visible light irradiation compared to that of Rb0.27WO3 and NiFe-CLDH. The photocatalytic efficiency of the Rb0.27WO3 and NiFe-CLDH is 39%, 45% and 42%, 34%, respectively, whereas for RWCLDH-700 composites are 91% and 93%. This enhancement in photocatalytic activity is attributed to the effective separation of electron-hole pairs. Moreover, the catalyst exhibited higher photocatalytic stability and retained its degradation efficiency up to 81% after four cycles. Finally, a possible decomposition mechanism was also discussed.Graphical abstractGraphical abstract for this article
       
  • Effects of specularity and particle-particle restitution coefficients on
           the recirculation characteristics of dispersed gas-particle flows through
           a sudden expansion
    • Abstract: Publication date: Available online 6 July 2018Source: Advanced Powder TechnologyAuthor(s): Subrat Kotoky, Amaresh Dalal, Ganesh Natarajan We numerically investigate the effects of restitution and specularity coefficients on the characteristics of dispersed gas-particle flows through a sudden expansion. The studies are carried out using an indigenous finite volume flow solver in a collocated framework with two-fluid model. Parametric studies are performed to gain insights into the differences in recirculation patterns that arise due to variations in restitution and specularity coefficients. The simulations show that particle-particle interactions, quantified by restitution coefficient (e) have a greater impact on recirculation characteristics than particle-wall interactions, which are quantified by specularity coefficient (ϕ). Studies reveal that the recirculation lengths tend to decrease as particle collisions become more elastic (as e tends to unity) while they increase, as the value of ϕ increases. However, the changes in recirculation length is very gradual and less pronounced when only particle-wall interactions are considered as compared to particle-particle interactions. From the range of parametric variations studied in this work, the maximum recirculation length has been found when the value of ϕ is maximum and that of e is minimum.Graphical abstractGraphical abstract for this article
       
  • Synthesis of metastable cubic tungsten carbides by electrical explosion of
           tungsten wire in liquid paraffin
    • Abstract: Publication date: Available online 6 July 2018Source: Advanced Powder TechnologyAuthor(s): Shigeru Tanaka, Ivan Bataev, Hayato Oda, Kazuyuki Hokamoto This paper describes experiments addressing the synthesis of WC1−x (metastable cubic tungsten carbide). The experiments involved exploding tungsten wires of different diameters by passing high-current electric pulses through them. This was done while the wire was immersed in a liquid-paraffin media. The explosion was studied using a high-speed video camera and by analysis of the voltage and current signals. The different stages of the wire explosion were explained based on an analysis of the recorded signals and simple thermodynamic considerations. In most of the experiments, the wire was sublimated, and the formation of carbide particles occurred due to a chemical reaction between the explosion products and the paraffin, as well as the rapid condensation of the vapors. The synthesized powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA). It was found that, regardless of the experimental conditions, the WC1−x phase contained approximately 42.5 at.% carbon. If the energy injected into the wire was not sufficient to completely evaporate the tungsten, large particles consisting of WC, W2C, and W phases were formed via the liquid-state diffusion mechanism.Graphical abstractGraphical abstract for this article
       
  • Modeling and simulations of nanofluids using classical molecular dynamics:
           Particle size and temperature effects on thermal conductivity
    • Abstract: Publication date: Available online 6 July 2018Source: Advanced Powder TechnologyAuthor(s): El Mehdi Achhal, Hicham Jabraoui, Soukaina Zeroual, Hamid Loulijat, Abdellatif Hasnaoui, Said Ouaskit We use molecular dynamics simulations to investigate the thermal conductivity of argon-based nanofluid with copper nanoparticles through the Green-Kubo formalism. To describe the interaction between argon-argon atoms, we used the well-known Lennard-Jones (L-J) potential, while the copper–copper interactions are modeled using the embedded atom method (EAM) potential that takes the metallic bonding into account. The thermal conductivity of the pure argon liquid obtained in the present simulation agreed with available experimental results. In the case of nanofluid, our simulation predicted thermal conductivity values larger than those found by the existing analytical models, but in a good accordance with experimental results. This implies that our simulation is more adequate, to describe the thermal conductivity of nanofluids than the previous analytical models. The efficiency of nanofluids is improved and the thermal conductivity enhancement is appeared when the particle size and temperature increase.Graphical abstractGraphical abstract for this article
       
  • Investigating the fluidization of disk-like particles in a fluidized bed
           using CFD-DEM simulation
    • Abstract: Publication date: Available online 5 July 2018Source: Advanced Powder TechnologyAuthor(s): Huaqing Ma, Yongzhi Zhao Fluidization of monodispersed disk-like particles with different aspect ratios in the fluidized bed is simulated by CFD-DEM, with disk-like particles being modeled by the super-ellipsoids. The relatively comprehensive investigations are performed in order to understand the fluidization behaviors of disk-like particles and to evaluate how the aspect ratio influences the fluidization. The results obtained demonstrate that disk-like particles with a larger aspect ratio possess stronger particle movement and more apparent fluidization. Comparisons between spherical particles and disk-like particles elucidate their differences in the fluidization behavior. Particle orientation is also investigated in this paper due to its important influence on the fluidization. Particles possess different preferred orientations in the static bed and in the fluidization state, and a reduced aspect ratio can drive particles to be in the preferred orientation. The existence of the walls will prompt particles to align their cross sections to be parallel to the plane of the walls.Graphical abstractGraphical abstract for this article
       
  • Densification and microstructural evolution of spark plasma sintered NiTi
           shape memory alloy
    • Abstract: Publication date: Available online 4 July 2018Source: Advanced Powder TechnologyAuthor(s): C. Velmurugan, V. Senthilkumar, Krishanu Biswas, Surekha Yadav The effect of particle size and sintering temperature on the densification and microstructural characteristics of nickel-titanium shape memory alloy (NiTi-SMA) has been investigated using spark plasma sintering (SPS) process. The Ni and Ti elements in different particle sizes were alloyed in the composition of Ni50.6Ti49.4. The milled NiTi powders were consolidated using SPS process in a temperature range of 700–900 °C. The densification was characterized by plotting temperature, current and relative displacement of punch as a function of holding time. The results showed that a maximum relative density of ∼98% can be achieved for NiTi-SMA with an average particle size of 10 µm at a sintering temperature of 900 °C. The microstructure of the sintered NiTi-SMA was examined using scanning electron microscope (SEM) and composition of NiTi alloy was analyzed using energy dispersive spectroscopy (EDS) analysis. The effect of sintering temperature on the microstructural evolution and transformation was also studied.Graphical abstractGraphical abstract for this article
       
  • High purity synthesis of ZrB2 by a combined ball milling and carbothermal
           method: Structural and magnetic properties
    • Abstract: Publication date: Available online 4 July 2018Source: Advanced Powder TechnologyAuthor(s): Mustafa Baris, Tuncay Simsek, Telem Simsek, Sadan Ozcan, Bora Kalkan The present work provides a new insight into the high purity synthesis of zirconium diboride (ZrB2) powders and a method of controlling impurity during the synthesis process. The single phase ZrB2 nano-powder was synthesized by a combined ball milling and carbothermal method using zirconium oxide (ZrO2), boron oxide (B2O3) and carbon (C) as starting materials. The reaction pathway, phase purity, and morphology of the ZrB2 produced are elucidated from X-ray diffraction (XRD) and scanning electron microscopy studies. The details of the impure phases generated during synthesis were obtained from multi-phase Rietveld refinements of XRD data. Experiments revealed that the method of synthesis carried out at 1750 °C involving ZrB2:B2O3:C at a molar ratio of 1:4.5:7.5 could produce highly pure ZrB2 nano-powders of 67 nm average crystallite size. The magnetometry studies on such pure form of ZrB2 nano-powders indicated that both paramagnetic and diamagnetic characteristics coexisted in ZrB2, which could be attributed to its polycrystallinity.Graphical abstractGraphical abstract for this article
       
  • Enhancement of methane production by Methanosarcina barkeri using Fe3O4
           nanoparticles as iron sustained release agent
    • Abstract: Publication date: Available online 3 July 2018Source: Advanced Powder TechnologyAuthor(s): Rong Chen, Yasuhiro Konishi, Toshiyuki Nomura Anaerobic digestion has attracted attention because it does not require power for aeration, it reduces excess sludge and it generates methane gas. However, the growth rate of anaerobic microorganisms is slow, resulting in low treatment efficiency. In this study, the impact of Fe3O4 nanoparticles (NPs) on the growth of methanogens, which is the rate-determining step in anaerobic digestion, was investigated using a pure culture of Methanosarcina barkeri as the model methanogen. M. barkeri were cultivated in iron free medium, as well as in media amended with various concentrations of Fe3O4 NPs with a mean diameter of 8.1 ± 2.4 nm. The production of methane gas was greatly increased when organisms were cultured in media containing NPs. After the methane production was saturated, methanol was newly added to the culture, which resulted in additional methane generation at a higher production rate than occurred during the initial round of cultivation in media containing 20 ppm Fe3O4 NPs. In addition, no evidence of negative impacts of Fe3O4 NPs on the growth of M. barkeri was observed. Taken together, these results strongly suggest that adding Fe3O4 NPs into the fermenter as an agent of sustained iron release can enable sustainable methane fermentation.Graphical abstractGraphical abstract for this article
       
  • Wavelet multi-resolution analysis on particle dynamics in a horizontal
           pneumatic conveying
    • Abstract: Publication date: Available online 2 July 2018Source: Advanced Powder TechnologyAuthor(s): Yan Zheng, Akira Rinoshika The particle velocities are measured by the high-speed particle image velocimetry (PIV) in the acceleration and fully developed regimes of a horizontal pneumatic conveying. Based on the measured particle fluctuation velocities, continuous wavelet transform and one-dimensional orthogonal wavelet decomposition were applied to reveal particle dynamics in terms of time frequency analysis, the contribution from wavelet level to the particle fluctuation energy, spatial correlation and probability distribution of wavelet levels. The time frequency characteristics of particle fluctuation velocity suggest that the small-scale particle motions are suppressed and tend to transfer into large scale particle motions from acceleration regime to fully developed regime. In the near bottom part of pipe, the fluctuation energy of axial particle motion is mainly contributed from the wavelet levels of relatively low frequency, however, in the near top part of pipe, wavelet levels of relatively high frequency make comparable contribution to the axial particle fluctuation energy in the suspension flow regime, and this contribution decreases as particles are accelerated along the pipe. The low frequency wavelet levels exhibit large spatial correlation, and this spatial correlation increases as the particles flow from acceleration regime to fully developed regime. The skewness factor and kurtosis factor of wavelet level suggest that the deviation of Gaussian probability distribution is associated with the central frequency of wavelet level, and the deviation from Gaussian distribution is more evident as increasing central frequency. The higher wavelet levels can be linked to small sale particle motions, which lead to irregular particle fluctuation velocity.Graphical abstractGraphical abstract for this article
       
  • Effect of Mn doping concentration on structural, vibrational and magnetic
           properties of NiO nanoparticles
    • Abstract: Publication date: Available online 2 July 2018Source: Advanced Powder TechnologyAuthor(s): Kiran N. Patel, M.P. Deshpande, Krishna Chauhan, Piyush Rajput, Vivek P. Gujarati, Swati Pandya, Vasant Sathe, S.H. Chaki The Ni1−xMnxO (x = 0.00, 0.02, 0.04 and 0.06) nanoparticles were synthesized by chemical precipitation route followed by calcination at 500 °C for 4 h. The prepared samples were characterized by energy dispersive analysis of X-rays (EDAX), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). Rietveld refinement of XRD data confirms the structural phase purity and XRD patterns are well indexed to NaCl like rock salt fcc crystal structure with Fm-3m space group. The particle size of Mn doped samples is found to be less than that of pure NiO sample. However, the particle size increases slightly on increasing the Mn concentration due to surface/grain boundary diffusion. The vibrational properties of the synthesized nanoparticles were investigated by Raman and FT-IR spectroscopy. The results of room temperature magnetization (M-H) and temperature dependent magnetization (M-T) measurements are explained with a core-shell model. The synthesized nanoparticles show weak ferromagnetic and super-paramagnetic like behavior at room temperature.Graphical abstractGraphical abstract for this article
       
  • Synthesis of Ni-doped LaSrMnO3 nanopowders by hydrothermal method for SOFC
           interconnect applications
    • Abstract: Publication date: Available online 30 June 2018Source: Advanced Powder TechnologyAuthor(s): Sang Yun Lee, Juyeon Yun, Weon-Pil Tai Ni-doped lanthanum strontium manganite (LSMN) nanopowders, La0.7Sr0.3Mn1−xNixO3 (0.05 ≤ x ≤ 0.3) were synthesized at 150 °C for 8 h by hydrothermal reaction as a function of Ni doping concentration. The SEM analyses suggested that the calcination treatment influenced the morphology of the nanopowders. The calcined nanopowders at 1300 °C had agglomerated spherical structure of 44–77 nm. Meanwhile, the XRD studies revealed that the nanopowders have single crystalline phase over the range x = 0.05–0.2. In addition, the LSMN nanopowders were sintered at elevated temperatures, 1250–1350 °C to examine their electrical conductivity for solid oxide fuel cell (SOFC) interconnect applications under actual SOFC working condition. Their electrical conductivity gradually increased to 90.05 S/cm with Ni doping concentration x = 0.2, which were sintered at 1300 °C. These results suggest La0.7Sr0.3Mn0.8Ni0.2O3 displays a good performance as an optimal composition of the LSMN.Graphical abstractGraphical abstract for this article
       
  • Improved dust management at a longwall top coal caving (LTCC) face –
           A CFD modelling approach
    • Abstract: Publication date: Available online 28 June 2018Source: Advanced Powder TechnologyAuthor(s): Ting Ren, Zhongwei Wang, Jian Zhang Dust management at longwall faces has always been a concern for mine operators. Recent respirable dust monitoring at a longwall top coal caving (LTCC) face indicated that extremely high dust exposure levels have been experienced at the face. Dust contamination from intake ventilation and the incorrect use of ventilation arrangements (i.e. curtains) at maingate (MG) area were identified as the main cause of this issue. Computational Fluid Dynamics (CFD) modelling studies were therefore conducted to investigate the impact of different ventilation arrangements on the dispersion behaviour of respirable dust at the LTCC face, with a special focus on the airflow patterns and the aerodynamics of fugitive dust at the intersection of MG and face. Field investigation was first carried out to observe the dust issue and obtain essential data for the development and validation of base model. Then parametric studies were conducted to evaluate the effectiveness of two different curtain configurations at MG considering the worst scenario of intake dust contamination to face (dust from travel road and beam stage loader (BSL) discharge point flows towards face) with the shearer cutting into the MG. Model results demonstrate that the occurrence of flow separation and incorrect use of curtains account for the main reasons of high dust exposure level at the intersection of MG and face, especially when the shearer is cutting into the MG. Ventilation arrangements at the MG and face entry are critical to minimise the impact of flow separation on the dust flow patterns at the intersection. Based on model results, new ventilation arrangements at the MG and face entry have been proposed and evaluated through which significant dust mitigation effect can be achieved at face entry, contributing to the overall reduction of dust exposure levels along the face.Graphical abstractGraphical abstract for this article
       
  • An investigation into the parameters affecting the breakdown voltage and
           inter-particle bonding in the electrical discharge compaction of metal
           powders
    • Abstract: Publication date: Available online 27 June 2018Source: Advanced Powder TechnologyAuthor(s): A. Darvizeh, M. Alitavoli, N. Namazi The aim of present investigation is to gain deeper understanding of breakdown behavior and inter-particle bonding by conducting experimental tests. This may lead to improve the state of compaction by relative arrangement of initial parameters to maintain uniform distribution of current density and producing compacts with sufficient mechanical strength. Experimental work was carried out using two different set-ups. The first arrangement was employed to provide steady-state alternating voltage. The effect of column geometry and particle size on breakdown voltage was investigated under this condition. The second set-up, capacitor discharge circuit, was used to provide impulse voltage. Under this condition, the influence of column geometry, particle size, application of axial pressure, evacuation of air, energy input, electrode material and configuration on breakdown voltage was studied. Also, scanning electron microscopy was employed to study the effect of different parameters on inter-particle bonding. The results of experiments conducted on the influence of each of the voltage and capacitance on the compaction properties are also discussed.Graphical abstractGraphical abstract for this article
       
  • Antibiofilm, anti cancer and ecotoxicity properties of collagen based ZnO
           nanoparticles
    • Abstract: Publication date: Available online 23 June 2018Source: Advanced Powder TechnologyAuthor(s): Sekar Vijayakumar, Baskaralingam Vaseeharan The use of natural biopolymers in the synthesis of nanomaterials can have a low cost and eco-friendly approach. ZnO nanoparticles synthesized through biological method has been reported to have biomedical applications to control pathogenic microbes as it is cost effective compared to commonly used physical and chemical methods. In this work we would like to report the “bioinspired” synthesis of ZnO nanopowders (ZnO-NPs) using type 1 collagen. Collagen based ZnO NPs (Cl-ZnO NPs) were bio-physically characterized by UV–vis Spectroscopy, XRD, FTIR, HR-TEM, EDX and Zeta potential analysis. HR-TEM recorded the presence of hexagonal wurtzite structure of Cl-ZnO NPs with particle size ranged between 20–50 nm. Further, Cl-ZnO NPs exhibited antibacterial and antibiofilm activity against Gram positive Streptococcus mutans, Gram negative Proteus vulgaris and fungi Candida albicans at 75 μg/ml. Moreover, the cytotoxicity assay demonstrated that the Cl-ZnO NPs was not toxic to murine (RAW 264.7) macrophage cells up to 75 μg/ml. However, it exhibited cytotoxicity against human liver cancer (HepG2) cells at 75 μg/ml. The HepG2 cell viability was significantly reduced at 75 μg/ml. In addition, the ecotoxicity of Cl-ZnO NPs on the freshwater micro crustacean Daphnia longicephala showed no mortality up to 250 μg/ml. The current study clearly demonstrated that the Cl-ZnO NPs had greater potential for antimicrobial and anticancer activities.Graphical abstractGraphical abstract for this article
       
  • Tweaking the diameter and concentration of carbon nanotubes and sintering
           duration in Copper based composites for heat transfer applications
    • Abstract: Publication date: Available online 22 June 2018Source: Advanced Powder TechnologyAuthor(s): R. Vignesh Babu, Kunwar Avanish Verma, M. Charan, S. Kanagaraj Copper (Cu) gained its importance in several applications due to its attractive thermal characteristics. However, its applications are limited, wherever high strength and high thermal conductivity are desirable. Thus, an attempt was made to develop Cu/CNT composites having the improved mechanical and thermal properties. Initially, Cu/CNT composite powder was synthesized through molecular level mixing technique, where the functionalized 20–40 nm and 40–60 nm diameter CNT with varying concentrations from 0.25 to 1.0 wt.% with an increment of 0.25 wt.% were used. The powder was uniaxially compacted at 800 MPa and sintered in the range of 2–8 hr at 900 °C. The best characteristics of Cu/CNT composites obtained from the present study are as follows: Relative density (RD) – 89.1%, Hardness – 61.2 ± 0.58 VHN, Thermal conductivity – 343 W/mK and these characteristics obtained their maximum value at 0.25 wt.% CNT concentration and started to decrease irrespective of CNT diameter.Graphical abstractGraphical abstract for this article
       
  • Experimental and numerical investigation of effects of particle shape and
           size distribution on particles’ dispersion in a coaxial jet flow
    • Abstract: Publication date: Available online 21 June 2018Source: Advanced Powder TechnologyAuthor(s): Wei Zhang, Kazuki Tainaka, Seongyool Ahn, Hiroaki Watanabe, Toshiaki Kitagawa In this study, an experimental and a numerical investigations are performed to investigate the effect of particle’s shape and size distribution on its dispersion behavior. Firstly, particle dispersion of pulverized coal and spherical polymer particles is observed by Particle Image Velocimetry (PIV) technique in the experiment. Secondly, a simulation is performed to analyze the particle dispersion in detail. Spherical and spheroidal motion models are applied to particle’s movement to investigate the shape effect. Furthermore, monodisperse and polydisperse for particles are applied to investigate the size distribution effect on the dispersion. Experimental results show that in the jet turbulence flow, pulverized coal particles, which have complex shapes and various sizes, have quite different dispersion behavior compared to spherical particles. In terms of the results of the simulation, this difference is mainly caused by the size distribution effect. Although particle’s shape affects the dispersity, it is weakened by the size distribution effect.Graphical abstractGraphical abstract for this article
       
 
 
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