Publisher: Elsevier   (Total: 3147 journals)

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Showing 1 - 200 of 3147 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 39, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 26, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 106, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 44, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 7)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 6)
Acta Astronautica     Hybrid Journal   (Followers: 448, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 30, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 12, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 5, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 326, 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: 2, SJR: 1.793, CiteScore: 6)
Acta Psychologica     Hybrid Journal   (Followers: 26, 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   (Followers: 1)
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: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 18, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 13, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 190, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 13, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 17, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 30, 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: 12, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 12, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, 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: 1, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 35, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, 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: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 29, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 11, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 11, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 21, 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: 16)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 14)
Advances in Digestive Medicine     Open Access   (Followers: 13)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 45, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 30, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 51, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 2)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 68, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 21, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 8, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 4, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 37, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, 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: 9, 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: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 17, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 9, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 26)
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: 5)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18, 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: 6, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 27, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 19)
Advances in Pharmacology     Full-text available via subscription   (Followers: 17, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 10, 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: 11)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
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: 69)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 3, 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: 7)
Advances in Space Research     Full-text available via subscription   (Followers: 431, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 6)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 37, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 57, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 396, 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: 12, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 490, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 18, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 32, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 47, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 8, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 12)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, 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: 11, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 55, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 6, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 6, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 58, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 67, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 48, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 13)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 15, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 40, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 37, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 50)
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: 267, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 67, 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: 32, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 30, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, 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: 67, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 25, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
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: 6, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 216, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 13, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 25, 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: 238, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 8, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)
Annales d'Endocrinologie     Full-text available via subscription   (Followers: 3, SJR: 0.451, CiteScore: 1)

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Similar Journals
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  [3147 journals]
  • Structural, electrical and electrochemical properties of ZnO nanoparticles
           synthesized using dry and wet chemical methods
    • Abstract: Publication date: Available online 23 January 2020Source: Advanced Powder TechnologyAuthor(s): M.G. El-Shaarawy, M. Khairy, M.A. MousaThe effect of particle size and morphological structure on the electrical and electrochemical properties of ZnO (nanowires, nanorods, and nanospheres) prepared by two various routes: soft-wet and dry methods were investigated. The electrochemical performance is analyzed by cyclic voltammetric and galvanostatic charge–discharge measurements in 1 M KOH, whereas their electrical conductivity, and dielectric constant are measured by electrochemical impedance spectroscopy in a temperature range 293–383 K and frequencies from 102 to 107 Hz. All samples showed semiconducting behavior with conductivity values depending on the particle size and the morphological structure of the sample. The prepared samples showed supercapacitance behavior with capacitance values lie between 77 and 330F g−1 and depend upon the morphological structure. The nanowire's structure showed the highest capacitance and good cycling stability. The high performance depends on the nanocrystalline size and the high surface area of the nanowire sample.Graphical abstractGraphical abstract for this article
       
  • Application of response surface methodology to optimize high active
           Cu-Zn-Al mixed metal oxide fabricated via microwave-assisted solution
           combustion method
    • Abstract: Publication date: Available online 22 January 2020Source: Advanced Powder TechnologyAuthor(s): Mojgan Hashemzehi, Vahid Pirouzfar, Hamed Nayebzadeh, Afshar AlihosseiniThe present work deals with evaluation of decisive parameters on performance and structure of Cu0.4Zn0.6Al2O4 catalyst. In this respect, the experiments were designed by the response surface methodology (RSM), considering the main parameters: the amounts of urea and ammonium acetate and the activity were assessed in esterification reaction. The results of statistical analysis showed that the proposed second-order equation is highly compatible with experimental data and the interaction between the ratios of both fuel types is highly effective as well independent variables. The catalyst synthesized with the fuel content higher than the stoichiometric ratio (67% urea and 45% ammonium acetate) has the highest catalytic activity in the esterification reaction, where the efficiency of about 98.2% is obtained in the esterification reaction under the conditions of 180 °C, methanol to oleic acid molar ratio of 9, 3 wt% of catalyst and 6 h of reaction time. The sample fabricated with 67% urea and 45% ammonium acetate as fuel (more than stoichiometric ratio) presented the highest activity that could convert 98.2% of oleic acid to ester. Characterization of the catalysts showed that the particle size reduced from about 18 nm for the catalyst synthesized with single fuel to 12 nm for that synthesized at fuel rich condition. Moreover, the unit cell size was meaningfully changed by using combined fuel that can be related to incorporation of simultaneous Zn and Cu for preparation of aluminate structure. As well as use of combination urea and ammonium acetate led to increase the textural properties (surface area from 4.76 m2·g−1 to 8.39 m2·g−1 and mean pore size from 2.1 nm to 8.9 nm). The results can confirm formation of dopant structure of Zn/CuAl2O4 in which a few amount of single phase was detected.Graphical abstractGraphical abstract for this article
       
  • Green synthesized silver nanoparticle from Allium ampeloprasum aqueous
           extract: Characterization, antioxidant activities, antibacterial and
           cytotoxicity effects
    • Abstract: Publication date: Available online 22 January 2020Source: Advanced Powder TechnologyAuthor(s): Fereshteh Jalilian, Azam Chahardoli, Komail Sadrjavadi, Ali Fattahi, Yalda ShokoohiniaIn the current study for the first time, silver nanoparticles (AgNPs) were biosynthesized by reducing agents from hot water extract of Allium ampeloprasum, an antibacterial and anti-inflammatory edible plant. UV–vis. spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometric, and transmission electron microscopy (TEM) analyses have been applied to confirm the formation of biosynthesized AgNPs. Total phenol content and antioxidant activities of AgNPs and extract together with their antibacterial and cytotoxic properties, were evaluated. According to TEM, AgNPs were spherical with a diameter of 8–50 nm. Total phenolic compounds were 15.58 μg/mL, and 10.94 μg/mL at a concentration of 150 μg/mL for the A. ampeloprasum extract and the biosynthesized AgNPs, respectively. Biosynthesized AgNPs showed significant antioxidant activity (81%) as compared to A. ampeloprasum extract (32%) and were active on multi-drug resistant P. aeruginosa. Besides, the cytotoxic activity response was also demonstrated that AgNPs were more potent than the A. ampeloprasum extract and showed high activity against Hela cell line with an IC50 value of less than 25 µg/mL. In conclusion, AgNPs synthesized by A. ampeloprasum extract with excellent antioxidant and antibacterial effects and acceptable cytotoxicity on cervical cancer cells have the potential to be used in biological applications.Graphical abstractGraphical abstract for this article
       
  • Discrete element method simulation analysis of the generation mechanism of
           cooperative behavior of disks falling in a low-density particle bed
    • Abstract: Publication date: Available online 21 January 2020Source: Advanced Powder TechnologyAuthor(s): Daichi Kawabata, Mikio Yoshida, Atsuko Shimosaka, Yoshiyuki ShirakawaPacheco-Vázquez and Ruiz-Suárez reported an interesting cooperative behavior for disks falling in a particle bed. This behavior involved the formation of upward and downward convex configurations during the falling of five steel disks into a bed of polystyrene particles. We used discrete element method simulations to investigate the generation mechanism for this cooperative behavior. Particles with a diameter of 5.0 mm and a density of 14.0 kg/m3 were placed randomly in a container with a width of 900 mm or 2700 mm and a height of 2700 mm. Model spheres with the same mass and diameter as the steel disks with a diameter of 25.4 mm and a thickness of 5.0 mm were then dropped into the particle bed, and we investigated the cooperative behavior of the model spheres. Similar cooperative behaviors were observed for the containers with widths of 900 mm and 2700 mm, indicating that the container side walls do not affect the occurrence of this behavior when the width is larger than 900 mm. The falling velocity of each disk was strongly dependent on the packing fractions over the disk and the flow velocity of the bed particles around the disks. Based on these results, the generation mechanism of the upward and downward convex configurations is discussed.Graphical abstractGraphical abstract for this article
       
  • Understanding the wetting properties of nanostructured strontium titanate
           and its application for recyclable oil/water separation
    • Abstract: Publication date: Available online 17 January 2020Source: Advanced Powder TechnologyAuthor(s): Parul Raturi, J.P. SinghIn the present work, we have investigated the oil and water wetting properties of strontium titanate nanoparticles. The as-synthesized nanoparticles were coated on the stainless steel mesh to investigate wetting properties. The coated mesh was found to have superhydrophilic and superoleophilic behavior with a contact angle value of nearly zero degree for both water as well as oil. Further underwater oil contact angle was measured, showing underwater superoleophobic behavior of the coated mesh. The underlying mechanism was studied for the wetting behavior of strontium titanate coated mesh. The coated mesh was then utilized for the gravity-driven separation of different oil/water mixtures. The separation mesh can be used multiple times showing its antifouling property along with recyclability. Further, a capillary pressure based model was developed to explain the wettability contrast for water and oil as well as separation of the two liquid phases on passing through the separation device. The approach here used for fabrication is applicable for large-area fabrication making it convenient and cost-effective towards oil/water separation at large scale.Graphical abstractGraphical abstract for this article
       
  • Metal encapsulation in zeolite particles: A rational design of
           zeolite-supported catalyst with maximum site activity
    • Abstract: Publication date: Available online 17 January 2020Source: Advanced Powder TechnologyAuthor(s): Mutjalin Limlamthong, Siriluck Tesana, Alex C.K. YipZeolite-supported metal catalysts have been proven effective in many important catalytic reactions, such as hydrogenation, Fisher-Tropsch synthesis, automobile exhaust catalysis, selective catalytic reduction and many others. Despite the successful preparation of the catalyst through widely adopted methods, including ion exchange and impregnation, the metal dispersion over the zeolite is lack of control with high randomness. This renders the so-called “catalytic performance” an overall contribution from the metal sites located inside the zeolite micropores and those located on the external surface. This is exceptionally true for small to medium pore zeolites with typical free apertures of 0.3–0.6 nm (such as LTA and MFI). A more rational design of zeolite-supported metal catalysts is by encapsulating the metal nanoparticles or clusters within zeolite pores prior to the zeolite formation. Encapsulation of metals in zeolite prevents them from sintering and sulphur poisoning by cage confinement and molecular exclusion (via well-defined pore size and shape), respectively. This paper gives a new perspective on using metal clusters and nanoparticles as catalysts and the design of an effective zeolite-supported catalytic system.Graphical abstractGraphical abstract for this article
       
  • Mesoporous magnetic biochar composite for enhanced adsorption of malachite
           green dye: Characterization, adsorption kinetics, thermodynamics and
           isotherms
    • Abstract: Publication date: Available online 17 January 2020Source: Advanced Powder TechnologyAuthor(s): A.S. Eltaweil, H. Ali Mohamed, Eman M. Abd El-Monaem, G.M. El-SubruitiThis study aimed to prepare a corn straw-derived biochar supported nZVI magnetic composite (nZVI/BC) and evaluate its efficiency in adsorption of malachite green dye (MG). The prepared nZVI/BC composite was characterized by XRD, FTIR, TEM, TEM-EDS, VSM, XPS, TGA, zeta potential and BET surface area. The prepared mesoporous composite showed an enhanced efficiency for the adsorption of MG dye. Adsorption models and kinetic results indicated that the adsorption of MG onto nZVI/BC composite was more fitted to Langmuir isotherm and follows second order kinetics. Intraparticle diffusion model indicated that the adsorption follows a three steps mechanism. The maximum adsorption capacity of nZVI/BC composite (515.77 mg MG/g composite) was much higher than most of reported biochar adsorbents. The removal process of MG onto nZVI/BC composite does not only proceed via adsorption mechanism, but also through an oxidative degradation mechanism. The Magnetic character of the biochar enables its easy separation and reuse for many cycles.Graphical abstractGraphical abstract for this article
       
  • An efficient chemical precipitation route to fabricate 3D flower-like CuO
           and 2D leaf-like CuO for degradation of methylene blue
    • Abstract: Publication date: Available online 17 January 2020Source: Advanced Powder TechnologyAuthor(s): Qian Liu, Wenyong Deng, Qingwen Wang, Xinchen Lin, Lei Gong, Changxiang Liu, Wanming Xiong, Xuliang NieA facile and eco-friendly way for fabrication of CuO is developed based on an one-step chemical precipitation route without calcination procedure or use of surfactant. The structure features of as-prepared CuO are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N2 adsorption-desorption experiment. X-ray diffraction analysis shows that CuO with particle size of 13.5–19.2 nm and crystallinity of 67.0–72.9% can be fabricated by the transformation of Cu(OH)2 precursor at bath temperature above 50 °C. By adjusting the oil bath temperature and the content of ammonium hydroxide, we demonstrate a formation mechanism to control CuO to be 2D leaf-like structure with large specific surface area of 33.4 m2/g and pore volume of 0.226 cm3/g, or 3D flower-like ones with specific surface area of 7.45–18.7 m2/g and pore volume of 0.0249–0.0850 cm3/g. The catalytic performances of as-prepared CuO are evaluated by monitoring degradation of methylene blue in the presence of hydrogen peroxide. Almost 100% methylene blue degradation rate can be reached after reaction for 210 min on 3D flower-like CuO synthesized with 10 mL ammonia content in oil bath of 50 °C. The high activity can be correlated with the morphology and pore volume of CuO. The present synthetic strategy is an inexpensive and convenient way suitable for large-scale fabrication of copper oxides, which are potential catalysts for organic compounds degradation.Graphical abstractGraphical abstract for this article
       
  • Tuning and controlling photocatalytic performance of TiO2/kaolinite
           composite towards ciprofloxacin: Role of 0D/2D structural assembly
    • Abstract: Publication date: Available online 17 January 2020Source: Advanced Powder TechnologyAuthor(s): Chunquan Li, Ningyuan Zhu, Xiongbo Dong, Xiaoyu Zhang, Ting Chen, Shuilin Zheng, Zhiming SunLamellar kaolinite supported monodispersed TiO2 was prepared through rational design and 0D/2D structural assembly, which showed significantly improved photocatalytic performance towards ciprofloxacin. After systematic evaluation, the pseudo-first-order kinetic constant rate of TiO2/kaolinite composite can reach to 0.04549 min−1, which was 6.90 and 1.81 times higher than that of pure TiO2 and P25, respectively. The nano-TiO2/kaolinite composite photocatalyst also displayed good reusability performance, only a slight decline occurred after four repeated experiments, which is beneficial for the large-scale application of photocatalysts. Various characterizations indicated that enhanced photocatalytic performance can be ascribed to the synergistic effect between natural kaolinite and the well distributed TiO2, which enhanced the light absorption ability, assisted the dispersion of pure TiO2, resulted in co-catalysis effect, improved the separation facilitation of photo-induced carriers and promoted the stronger adsorption capacity, etc. These merits effectively regulated the carriers’ lifetime and migration velocity of the photogenerated charge carriers. Considering the excellent properties of natural kaolinite (low cost, abundance, stability, etc.), our study provides a promising candidate for effective degradation of trace amounts of pharmaceutical and personal care product (PPCP) or contaminants with potential high-toxic risk.Graphical abstractGraphical abstract for this article
       
  • High performance of LiFePO4 with nitrogen-doped carbon layers
           for lithium ion batteries
    • Abstract: Publication date: Available online 11 January 2020Source: Advanced Powder TechnologyAuthor(s): Junke Ou, Lin Yang, Feng Jin, Shugen Wu, Jiayi WangHerein, we demonstrate a facile approach to fabricate a cathode material of LiFePO4 with nitrogen-doped carbon layers by applying egg white as both carbon source and nitrogen sources. The nitrogen doped carbon layers are in situ coated on the LiFePO4 particles, which effectively improves the electrical conductivity of rapid Li-ion diffusion. When evaluated as a cathode material for lithium ion batteries (LIBs), LiFePO4 material with nitrogen doped carbon shows high capacities of 164 mA h g−1 at 0.1 C, 144 mA h g−1 at 1 C and 120 mA h g−1 at 5 C. The result implies that such novel LiFePO4 material is a potential cathode material for LIBs.Graphical abstractA novel N-doped carbon coated LiFePO4 can deliver impressive electrochemical performances, with high capacities of 164 mA h g−1 at 0.1 C, 144 mA h g−1 at 1 C and 120 mA h g−1 at 5 C.Graphical abstract for this article
       
  • Implementation of ZnSnO3 nanosheets and their RE (Er, Eu, and Pr)
           materials: Enhanced photocatalytic activity
    • Abstract: Publication date: Available online 10 January 2020Source: Advanced Powder TechnologyAuthor(s): G. Gnanamoorthy, K. Ramar, A. Padmanaban, Virendra Kumar Yadav, K. Suresh Babu, V. Karthikeyan, V. NarayananZnSnO3, ZnSnO3@Er, ZnSnO3@Eu, and ZnSnO3@Pr materials were synthesized by a hydrothermal method, these active materials characterized by XRD, Raman, DRS-UV, FT-IR, BET surface areas and Scanning electron microscopy studies. The ZnSnO3 nanosheets meta-stable form was confirmed by XRD. Here, addressing to the pure and doped materials functional groups were evaluated by FT-IR spectroscopy. ZnSnO3, ZnSnO3@Er, ZnSnO3@Eu, and ZnSnO3@Pr rotational vibrations frequency modes were predicted by the Raman spectroscopy. Our results are marvelously, the obtained bandgap energies at 3.5 eV for pure sample and ZnSnO3@Er, ZnSnO3@Eu and ZnSnO3@Pr energies at 3.06 eV, 3.04 eV and 3.02 eV. The synthesized pure samples get a sheet-like morphology and doped for RE metals than morphology was changing for nanocubes. We assess for all samples that were focused on photocatalytic dye degradation for Methylene blue dye; hence, we are discussing these approaches, ZnSnO3@Pr/Methylene blue sample was a great improvement and high decolorization efficiency compared with ZnSnO3@Er, ZnSnO3@Eu nanocubes. The ZnSnO3@Pr sample surface area was investigated by BET analysis. In addition, we are testing the phenol degradation with wastewater. The ZnSnO3@Er, ZnSnO3@Eu catalysts were determined to the less efficiency when comparing to the ZnSnO3@Pr material. The ZnSnO3@Pr material results have more efficiency and a very good recyclable stability nature.Graphical abstractGraphical abstract for this article
       
  • Novel monopolar arrangement of multiple iron electrodes for the
           large-scale production of magnetite nanoparticles for electrochemical
           reactors
    • Abstract: Publication date: Available online 10 January 2020Source: Advanced Powder TechnologyAuthor(s): Puspita Nurlilasari, W. Widiyastuti, Heru SetyawanHigh-purity magnetite nanoparticles with a mixed quasi-spherical and cubic morphology have been successfully synthesized using a new alternating monopolar arrangement of multiple iron electrodes in water. The magnetite nanoparticles have a narrow size distribution with a mean size ranging from 20 to 30 nm, depending on the applied voltage and pH. The formation of magnetite nanoparticles is favored only in the pH range of 7–10; outside this range, magnetite nanoparticles cannot be produced. The magnetite nanoparticles exhibit ferromagnetic properties with saturation magnetization ranging from 16 to 75 emu/g. They demonstrated to be a promising electrocatalyst for oxygen reduction reactions in basic media. This facile method is a promising production route for magnetite nanoparticles and can be easily scaled up for large production.Graphical abstractGraphical abstract for this article
       
  • Synthesis and characterization of high-performance spherical urchin-like
           CoAl2O4 pigment prepared via microemulsion-hydrothermal-precipitation
           method
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Qikun Wang, Yongqing Wang, Kun Liu, Jianlei Liu, Chao Wang, Yang Wang, Qibing ChangIn this study, the spherical urchin-like CoAl2O4 pigment was prepared using a microemulsion-hydrothermal-precipitation (M-H-P) method. This method was used to prepare the high-performance CoAl2O4 pigment, which has good dispersibility, small particle size, narrow particle size distribution, and large BET surface area. Use of this method also successfully achieved the recycling of organic solvents. SEM and TEM results show that the CoAl2O4 pigment is the soft-aggregation of lamellar nanocrystals with a mean particle size of 1–1.2 μm. The urchin-like pigment exhibits better color performance than the previously reported CoAl2O4 pigment. After applying the pigment on a high-temperature transparent glaze, the pigment exhibits excellent coloration, indicating its potential application in ceramic decoration and ceramic ink-jet technology. This study provides a new method for preparing high-performance powders.Graphical abstractUltrafine spherical urchin-like CoAl2O4 pigment has been successfully prepared by microemulsion-hydrothermal-precipitation (M-H-P) method. This method not only prepared the high-performance CoAl2O4 pigment with good dispersibility, small particle size, narrow particle size distribution, large BET surface area and high color performance, but also successfully achieved the recycling of organic solvents.Graphical abstract for this article
       
  • Synthesis of rutile TiO2 powder by microwave-enhanced roasting followed by
           hydrochloric acid leaching
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Juanxue Kang, Lei Gao, Mingyuan Zhang, Jing Pu, Lin He, Rongsheng Ruan, Mamdouh Omran, Jinghui Peng, Guo ChenIn this paper, the preparation of synthetic rutile TiO2 powder from titanium slag by microwave-assisted activation roasting followed by hydrochloric acid leaching was investigated. The effects of the additive Na2CO3 on the crystal form, cell, crystallinity, phase transformation, surface functional groups and micro-surface structure of the calcined product were systematically studied using X-ray powder diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The results confirmed that the strongest characteristic Raman bands of rutile TiO2 and the weakest FT-IR bands of (CO3)−2 were found when the Na2CO3 mass ratio was 0.4. Accordingly, the crystallinity for the product, namely short rod structure rutile TiO2 powder, reached its peak value of 99.21% with a corresponding average grain size of 43.5 nm. The excessive Na2CO3 was found to be disadvantageous for the crystallinity of the product, since it formed a coverage on the surface of titanium slag which prevented the oxidation reaction for the decomposition of anosovite.Graphical abstractGraphical abstract for this article
       
  • Novel application of g-C3N4/NaNbO3 composite for photocatalytic selective
           oxidation of biomass-derived HMF to FFCA under visible light irradiation
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Yekun Zhu, Yun Zhang, Lili Cheng, Mohammed Ismael, Zhiyuan Feng, Ying WuThe g-C3N4/NaNbO3 photocatalyst was synthesized by simply calcining the mixture of NaNbO3 and melamine. The synthesized composite exhibits high photocatalytic performance in the selective oxidation of 5-Hydroxymethylfurfural (HMF) to 5-formyl-2-furancarboxylic acid (FFCA) when using water as solvent. The structure and composition of g-C3N4/NaNbO3 photocatalysts were characterized by TG, XRD, SEM, UV–Vis, FT-IR, and XPS methods, and the optical and electrochemical properties were investigated by EIS, PC, and PL techniques. O2− was inferred to be the primary active species in this process based on the active species trapping experiment. Heterostructure formation of g-C3N4/NaNbO3 composites efficiently promoted the separation of photo-generated electron-hole pairs and accelerated the electron transfer rate, thus reduced the formation of OH, and sequentially improved the selectivity of FFCA. The highest HMF conversion of 35.8% with FFCA selectivity of 87.4% was achieved on C/N-59.6 photocatalyst under the irradiation of visible light. The possible mechanism and reaction route were also proposed.Graphical abstractFFCA was achieved in high selectivity by photocatalytic oxidation of HMF over g-C3N4/NaNbO3 under visible light.Graphical abstract for this article
       
  • Effect of particle size on powder compaction and tablet strength using
           limestone
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Ramon Cabiscol, Hao Shi, Isabell Wünsch, Vanessa Magnanimo, Jan Henrik Finke, Stefan Luding, Arno KwadeProcessability of powders in high load compaction constitutes a challenge due to particle rearrangement, compression and breakage occurring simultaneously. Although tableting is a central operation in pharmaceutical technology, a better understanding of the link between the macroscopic powder behaviour and its micro-mechanical properties is still required. In the present study, a dual focus on the powder compaction behaviour and the quality properties of final tablets using a compaction simulator is presented. Tableting has been performed with a wide size range of limestone powders at various pressures from 10 to 400 MPa, in order to understand and compare the powder compaction behaviour at both low and high confining stresses.Compactibility of limestone, the relation between porosity and stress, has been assessed with both the classical (logarithmic) Heckel model and the newly proposed (double logarithmic) Wünsch model, confirming the improvement of the latter to enhance the description of the porosity change during compaction, as well as the model robustness towards non-pharmaceutical powders. The qualitative effect of particle size and thus cohesion on the bulk density at high pressure compaction is found to be very similar to the low pressure regime. However, the geometrical interlocking influence of large size powders found in a previous study becomes irrelevant at such high pressures. For d50
       
  • A comparative study of eco-friendly silver nanoparticles synthesis using
           Prunus domestica plum extract and sodium citrate reducing agents
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Seraj Mohaghegh, Karim Osouli-Bostanabad, Hossein Nazemiyeh, Yousef Javadzadeh, Alireza Parvizpur, Mohammad Barzegar-Jalali, Khosro AdibkiaThrough the current comparative study, colloidal silver nanoparticles (AgNPs) synthesized with various morphologies and sizes using Prunus domestica (P-dom) extract and sodium citrate as green and chemical reducing agents, respectively. AgNPs were synthesized employing different concentrations of the reducing agents in an aqueous solution at various pH values (3–10) and temperatures (25–85 °C). The UV–visible absorption spectrum indicated characteristic SPR peaks of AgNPs at 380–450 nm. Fourier transform infrared spectroscopy revealed aqueous-soluble polyols (such as glycosides, phenols, and flavanols) participation in Ag ions reduction to the corresponding AgNPs at various pH values. The crystallinity of AgNPs detected by an X-ray diffractometer. Different morphologies (polygonal, oval, and spherical) of AgNPs with varying pH values were confirmed conducting transmission electron microscopy (TEM). Average particle sizes of 16–50 nm were determined using scanning electron microscopy, TEM, and dynamic light scattering assessments for AgNPs synthesized at various reaction conditions. This study is a demonstration for a facile, cheap, and eco-friendly stimuli-sensitive synthesize of AgNPs.Graphical abstractGraphical abstract for this article
       
  • Numerical analysis of flow field and particle motion in a dynamic cyclonic
           selector
    • Abstract: Publication date: Available online 9 January 2020Source: Advanced Powder TechnologyAuthor(s): Chiara Galletti, Andrea Rum, Veronica Turchi, Cristiano NicolellaComputational Fluid Dynamics is employed to investigate the flow field and the fate of particles in a dynamic cyclonic classifier which is used to separate fine particles of dried sludge, produced as waste by pulp and paper-making processes. The cyclonic classifier is equipped with a rotating impeller, which improves the tangential flow, and a circular baffle, which distributes the inlet stream of gas and particles. Unsteady Reynolds-averaged Navier-Stokes equations are solved for the continuous phase, addressing the impeller motion though the Sliding Mesh approach, whereas Lagrangian tracking is employed for the particles. Surprisingly, the removal efficiency is found to be non monotonic with particle size, instead presenting a fish-hook shape. This is partly imputed to the presence of the circular baffle that promotes, in the bottom region of the cyclone, the formation of a nearly toroidal recirculation zone which entrains small particles, subsequently separated at the bottom. Moreover, too high inlet velocities were found to hamper the action of impeller rotation with a resulting detrimental effect on removal efficiency.Graphical abstractGraphical abstract for this article
       
  • Changes in the oxygen content, morphology, and microstructure of Mo-10Nb
           composite powders during mechanical alloying
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): Haiguang Li, Qingkui Li, Mangmang Guo, Xiaochao Wu, Kaijun Yang, Kunming Pan, Jilin HeThe prefabrication of Mo-Nb composite powders is an effective way of improving the homogeneity of Mo-10Nb targets, which have broad application prospects in the photoelectric sensor industry. However, this aspect has been rarely addressed so far. Therefore, we prepared Mo-10Nb composite powders by mechanical alloying (MA), and investigated the effects of the experimental parameters such as the milling speed and duration on the particle morphology, size distribution, compositional homogeneity, crystallite size, inner strain, and oxygen content. High-quality Mo-10Nb composite powders with 3-μm spherical particles of narrow size distribution, homogeneous elemental distribution, and nanometric crystalline structure were obtained by implementing optimum MA parameters, viz., a milling speed of 250 rpm and duration of 36 h using an MITR QM-QX-4L omnidirectional ball mill. The mechanically alloyed Mo-10Nb composite powders were prone to oxidation when exposed to air, which led to a sharp increase in the oxygen content to ∼5400 ppm. X-ray photoelectron spectroscopic analysis revealed the presence of Nb2O5, MoO2, and MoO3 on the surface of the Mo-10Nb particle. We believe that this study demonstrates an interesting strategy for the fabrication of high-quality Mo-10Nb targets.Graphical abstractGraphical abstract for this article
       
  • Particle behavior and parameter optimization in treatment of waste
           petroleum reforming catalysts based on a compound dry separator
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): Jinpeng Qiao, Pengfei Wen, Chenlong Duan, Weinan WangIn this research, the motion and distribution characteristics of waste palladium catalysts in a compound dry separator were investigated by DEM-CFD. Based on the actual separation experiments, the effects of various process parameters on separation performance were studied. The significance of both single factor and factor combination were analyzed. In addition, parametric majorization and further experimental verification were conducted. The results showed that, in the separation process, the rod-shaped catalysts are mainly distributed in backplane region and move along the backplane with a gradual weakening spiral motion, and the spherical catalysts are distributed in lattice-bar region and directly move to the discharge end. The maximum efficiency Ef is obtained when the amplitude (AM) is 3.0–3.5 mm, frequency (FR) is 32–38 Hz, gas velocity (GV) is around 1 m/s, and lateral-gradient (θ) is 4°–6°. The influence degree of various factors on Ef follows the order: FR > θ > AM > GV. An actual separation efficiency was 99.61% when GV = 0.96 mm, FR = 35.98 Hz, AM = 3.28 mm and θ = 5.64°, indicating a satisfactory separation performance of waste palladium catalysts using a compound dry separator.Graphical abstractGraphical abstract for this article
       
  • Shear controllable synthesis of barium sulfate particles using lobed inner
           cylinder Taylor-Couette flow reactor
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): Lu Liu, Xiaogang Yang, Guang Li, Xiani Huang, Chenyang XueA novel lobed inner cylinder assembled in Taylor-Couette flow reactor (LTC) has been adopted to synthesize barium sulfate particles. The fluid dynamics that affects synthesis of particles using both the LTC and the classical Taylor-Couette flow reactor (CTC) was investigated through CFD modelling and experiments. The results have demonstrated that the Taylor vortices and turbulence induced shear rate distribution in the reactors have a significant influence on the final particle size distribution. The narrower shear rate distribution in the LTC is beneficial to the synthesis of particles with smaller size. The local turbulence intensification in the intra-Taylor vortices in the LTC effectively reduces the low shear strain regions. A strong correlation between the synthesized particle size and the local turbulent dissipation rate is existing. Shear induced by small turbulent eddies can inhibit particle growth. The LTC can be used for effectively shear controllable synthesis of particles.Graphical abstractGraphical abstract for this article
       
  • Analysis of flame structure using detailed chemistry and applicability of
           flamelet/progress variable model in the laminar counter-flow diffusion
           flames of pulverized coals
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): Shota Akaotsu, Yohsuke Matsushita, Hideyuki Aoki, Weeratunge MalalasekeraPulverized coal is still found in many practical devices even though it is recognized as “dirty fuel” because of its CO2 and pollutant emissions. To overcome this problem, advanced coal utilization technologies have been developed using numerical simulations. In this study, the structures of the laminar counter-flow diffusion flames of pulverized coals were investigated by performing simulations based on detailed chemistry. The high-temperature region became narrower as the coal/air ratio increased, because of the departure from the stoichiometric mixture and local quenching by the heat transfer between the gas and solid phases. Further, the applicability of the flamelet/progress-variable (FPV) model was investigated through a priori and a posteriori tests. The a priori test confirmed that the FPV model is capable of reproducing the numerical solutions obtained using the detailed chemistry, including the mass fractions of minor species. In the a posteriori test, there was a slight difference between the FPV model and detailed chemistry results due to overestimation of the progress of the chemical reactions. Given the sufficiently high accuracy of the FPV model in various numerical conditions, it can be concluded that the extended FPV model has potential for use in turbulent coal combustion simulations.Graphical abstractGraphical abstract for this article
       
  • Flow phenomenon of micron-sized particles during cold spray additive
           manufacturing: High-speed optic observation and characterization
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): Libin Lalu Koithara, Rija Nirina Raoelison, Sophie CostilA high-speed laser shadowgraph observation of the particles flow during cold spraying enables a good phenomenological characterization. The particles in-flight behaviour develops a kinematics with two regimes regardless the powder nature. When leaving the nozzle, the particles form a regime of uniform jet over a certain distance along the flow direction, and then a regime of sparse jet while particles deviate in the radial direction. This dispersion increases away from the nozzle exit and exhibits thereby an event of oblique collision during an additive route process. Under such conditions, kinematic deficiency prevails since oblique collision has shown to alter the deposition efficiency, in the literature. Albeit these particles flow regimes represent a generic behaviour, there are differences in the powder’s response depending of their features that can be combined using the parameter ρpDp. The variance ρpDp in cold spraying is scaled through a few cases of powders (copper, aluminium, magnesium, cermet, and PEEK). The powders dispersion becomes more and more important as ρpDp decreases from high value (large Cu powders) down to low value (case of Mg powders). However, this tendency cannot be extrapolated to lightweight powders represented by the fine PEEK powders (low ρpDp) which are more stable over a larger distance due to a higher sensitivity to the axial component of the gas velocity. They get unstable later in the jet since they become sensitive to the radial component of the gas velocity due to a progressive decrease of the axial gas velocity. The fine WC-Co powders adopt similar behaviour since they are lightweight as the PEEK powders due to their porous structure.Graphical abstractGraphical abstract for this article
       
  • Adaptive Neuro-Fuzzy inference system analysis on sorption studies of
           strontium and cesium cations onto a novel impregnated nano-zeolite
    • Abstract: Publication date: Available online 8 January 2020Source: Advanced Powder TechnologyAuthor(s): H.S. Hassan, O.A. Abdel Moamen, W.F. ZaherIn this research, a novel impregnated nano-zeolite (NAASMS-Z) was synthesized and characterized using different characterization techniques. Excellent properties, such as high specific surface area (∼502.77 m2/g), low pore size (∼8.92 Å) and the existence of numerous functional groups caused the efficient elimination of Sr2+ and Cs+ cations from aquatic systems. The sorption performance of the nano-particles was enhanced by impregnation up to 60% in the aquatic media. The kinetic study indicated that the elimination process of both the concerned cations is controlled by external film mass transfer through the boundary within the first 30 min then controlled by intra-particle diffusion. The sorption equilibrium data suggested that the sorption process occurs on the heterogeneous sorbent surface. Parameters affecting the elimination of Sr2+ and Cs+ from a single metal sorption system, such as pH, initial contaminant concentration (Ci) and contact time (t), were investigated and optimized. A predictive model based on an Adaptive Neuro-Fuzzy Inference system (ANFIS) analysis was applied to evaluate the experimental parameters affecting the elimination of Sr2+ and Cs+ cations from aquatic system. A Mamdani-type FIS was employed to justify a collection of 16 rules (If-Then format) by means of centroid membership functions. The suggested fuzzy model revealed high predictive concert with high correlation coefficient (R2) and satisfactory deviation from the experimental data, affirming its appropriateness to predict Sr2+ and Cs+ elimination efficacy from the studied system. Rooted in experimental data and statistical analysis, the synthetized material was effective for treating contaminated aquatic solutions containing Sr2+ and Cs+ cations.Graphical abstractGraphical abstract for this article
       
  • Effects of metal oxide nanoparticles on combustion and gas-generating
           performance of NaN3/Al composite powders ignited using a microhotplate
           platform
    • Abstract: Publication date: Available online 7 January 2020Source: Advanced Powder TechnologyAuthor(s): Ho Sung Kim, Ji Hoon Kim, Ji Hye Ku, Myung Hoon Cho, Jung Keun Cha, Jong Man Kim, Hyung Woo Lee, Soo Hyung KimWe investigated the effects of different metal oxide (MO) nanoparticles (e.g., CuO, KIO4, Fe2O3) on the combustion and gas-generating characteristics of sodium azide microparticle (NaN3 MP; gas-generating agent) and aluminum nanoparticle (Al NP; heat source) composite powders. The NaN3 MP/Al NP/MO NP composite powders were stably ignited using a microhotplate (MHP) heater. The addition of CuO and KIO4 to the NaN3 MP/Al NP composite powders resulted in relatively high burn rates and high pressurization rates upon MHP-assisted ignition. This suggests that the highly reactive CuO and KIO4 NPs significantly increased the combustion of the Al NPs; as a result, sufficient heat energy was generated via the active aluminothermic reaction to thermally decompose the NaN3 MPs. Finally, the gas generating properties of NaN3 MP/Al NP composite powders mixed with various MO NPs were tested using homemade inflatable small airbags. The airbags were fully inflated within ∼20 ms when CuO and KIO4 NPs were added to the NaN3 MP/Al NP composite powders. However, the addition of Fe2O3 NPs to the NaN3 MP/Al NP composite powder resulted in a slow and only partial inflation of the airbag due to an incomplete aluminothermic reaction, which was due to a slow combustion reaction between the Al NPs and relatively weak oxidizer of the Fe2O3 NPs. This suggests that the rapid, stable, and complete thermal decomposition of NaN3 MP/Al NP composites can be effectively achieved by employing highly reactive nanoscale oxidizers.Graphical abstractGraphical abstract for this article
       
  • Simulation and experimental study on the stone powder separator of a
           vertical shaft impact crusher
    • Abstract: Publication date: Available online 7 January 2020Source: Advanced Powder TechnologyAuthor(s): Huaiying Fang, Jianhong Yang, Yi Song, Wenjing Huang, Junlong ChenDuring the sand-making process, the stone powder produced by means of a vertical shaft impact (VSI) crusher affects the sand quality and pollutes the environment. This paper focuses on experiments and simulations with a stone powder separator (SPS) that is installed in a VSI crusher. Using FLUENT software, a coupling model of computational fluid dynamics (CFD) and the discrete phase model (DPM) is used to simulate the airflow distribution and particle traces in a VSI crusher. The stone powder separation and large particle retention performance are evaluated considering two important factors: the structure of the SPS and the air volume of the induced draft fan. The simulation results show that the air volume of the induced draft fan intuitively influences the particle traces and the distributions of particles of different sizes in the crushing chamber and the SPS chamber. There are many vortexes in the crushing chamber that cause the aggregate particles to be fully dispersed under the action of turbulence, and the SPS structure with radius decreasing from bottom to top can form an airflow velocity gradient in the SPS chamber and selectively remove particles according to size, thus improving the stone powder separation performance (SPSP). For this structure, when the air volume of the induced draft fan is set to approximately 40% of the maximum value, it can not only avoid large particles being massively removed but also ensure better SPSP of the device. Finally, the simulation results are verified by experiments. The results of this paper provide a reliable numerical model for the calculation of the flow field in a VSI crusher and provide a reference for the structural optimization of the stone powder separation device and for the selection of the best air volume of the induced draft fan.Graphical abstractGraphical abstract for this article
       
  • Experimental study on the stable morphology and self-attraction effect of
           subaqueous barchan dunes
    • Abstract: Publication date: Available online 6 January 2020Source: Advanced Powder TechnologyAuthor(s): Bin Yang, Yong Su, Nan He, Bo Zhang, Xiaosi Zhou, Zhang YangThe evolutionary process of isolated dunes under the action of a unidirectional steady water flow is recorded from a bottom-up visual angle by optical synchronization imaging measurements. The morphological characteristics of dunes formed from different initial sand pile configurations are analyzed by an image-processing method. Results show that the trend of reproducing the crescent shape of the dune is shown in all sand piles, which is independent of the initial configuration. The triangular initial sand pile is found to be the first to stabilize to a crescent shape, whereas the square initial sand pile takes the longest time to form a stable crescent shape. This finding is essentially due to the shape effect of the triangle, which effectively reduces the amount of transverse moving sand particles. Based on the aspect ratio of the barchan dune that is stable at approximately 1, we determine that the evolution time required for the final stability of barchan dunes reproduced from different initial sand piles is approximately 200 s within the restriction of the present closed-water-tunnel experimental condition. Moreover, a dimensionless comparison of the profile curves of barchan dunes’ stable morphologies reveals a “streamwise–spanwise” dimension of the dune, which essentially synthesizes characteristic information about windward face and two horns. This “streamwise–spanwise” dimension ultimately presents the self-attraction effect of the crescent shape.Graphical abstractFig. 10. Processing technique of the profile curve of a stable barchan dune.Fig. 10 shows an example for frame 4100 (225 s) of the evolution of initial square sand pile into a barchan dune. Some moving particles exist around the edge of the barchan dune, inevitably leading to some undulations in the profile of the edge shape. Thus, one polar angle can correspond to several polar diameters in the final curve shape. However, the representation of characteristic points of the crescent shape on the curve is basically not affected. The curves obtained by the processing can necessarily represent the stable shapes of barchan dunes.Graphical abstract for this article
       
  • Effect of excitation parameters on motion characteristics and
           classification performance of rigid-flexible coupled elastic screen
           surface for moist coal
    • Abstract: Publication date: Available online 6 January 2020Source: Advanced Powder TechnologyAuthor(s): Haishen Jiang, Miao Pan, Chenlong Duan, Yuemin Zhao, Zhiguo Zhou, Chusheng Liu, Jinpeng Qiao, Long Huang, Guofu DaiElastic screen surfaces are widely used for classification of moist steam coal. In this study, a novel rigid-flexible coupled elastic screen surface was proposed, and its motion characteristics were investigated. Furthermore, the effect of excitation parameters on classification performance was analyzed. The results showed that the acceleration of the flexible elastic screen surface were markedly larger than those of the screen box due to the large deformation. The y-axis acceleration amplitudes of the elastic screen surface were about 150% higher than those of screen box, and showed a more pronounced increase during the feeding process, but decreased during the stable state compared to the no-load condition. With increasing total excitation force and frequency, the accelerations increased, the screening efficiency increased first and then decreased, while total misplaced materials changed in the opposite direction. The maximum screening efficiency of 83.15%, indicating the satisfactory classification performance for moist coal.Graphical abstractGraphical abstract for this article
       
  • Synthesis of nano titanium oxide with controlled oxygen content using
           pulsed discharge in water
    • Abstract: Publication date: Available online 6 January 2020Source: Advanced Powder TechnologyAuthor(s): Xin Gao, Chunxiao Xu, Hao Yin, Pengwan Chen, Xiaoguang Wang, Qiuzhi Song, Jianjun LiuDifferent titanium oxide nanoparticles were formed through pulsed discharge of Ti wires in distilled water and H2O2 solution. The recovered samples were characterized by various techniques, such as XRD, SEM and TEM. The results confirm the presence of various titanium oxide nanoparticles including TiO2 phases (anatase and rutile) and various nonstoichiometric TiO2−x in recovered samples owing to the oxygen deficient circumstance through pulsed discharge. The titanium oxide nanoparticles exhibit a spherical shape with a size of 10–300 nm. The results show that the energy input adjusted by charging voltage is one major factor to control the phases of titanium oxide and the overall oxygen content of recovered samples. In addition, the H2O2 content in distilled water also affects the oxygen content of recovered samples. The sample recovered from 10% H2O2 solution is pure TiO2 consisting of anatase and rutile without nonstoichiometric TiO2−x. Moreover, the UV–Vis absorption spectra of recovered samples show their intensive visible light absorption and the correlation between the visible light absorption and the experimental conditions (charging voltage and H2O2 content).Graphical abstractGraphical abstract for this article
       
  • Dynamic capture and accumulation of multiple types of magnetic particles
           based on fully coupled multiphysics model in multiwire matrix for
           high-gradient magnetic separation
    • Abstract: Publication date: Available online 6 January 2020Source: Advanced Powder TechnologyAuthor(s): Feiwang Wang, Dongdong Tang, Likun Gao, Huixin Dai, Peng Jiang, Mengyu LuHigh-gradient magnetic separation (HGMS) effectively separates fine weakly magnetic minerals using a magnetic matrix. The basic principle of single-wire capture of magnetic particles in HGMS has received considerable attention. In practice, however, a real matrix is made of numerous magnetic wires. Transport of magnetic particles inside a multiwire matrix under various operating conditions has not been sufficiently investigated, and it is not clear whether single-wire and multiwire matrices differ significantly. A fully coupled multiphysics model based on the idealized capture model was developed to investigate the 2D capture and accumulation of multiple types of particles in single-wire and multiwire matrices. In this model, the properties of multiple types of particles were defined. Then, particle tracing via the fluid flow model was used to calculate the dynamic capture and accumulation of particles under the determined magnetic and flow fields. The time-dependent dynamic capture mode used in this study can reveal the details of particle capture and accumulation in single-wire and multiwire matrices. All the calculations and analyses indicate that single-wire and multiwire matrices both exhibit basically the similar capture tendency as the particle size, slurry feed velocity, and magnetic induction are gradually increased, and a single-wire matrix always has a much higher capture selectivity than a multiwire matrix. This difference in selectivity between the single-wire and multiwire matrices results mainly from magnetic coupling between magnetic wires in the multiwire matrix, where the fluid flow is also quite complicated. In addition, adjacent columns of wires are staggered vertically, increasing the probability of collisions between the particles and the wires; thus, intergrowth particles that are not captured by the upstream wires are more easily captured by the downstream wires. By comparing the experimental results with the simulation results, the correctness of the HGMS recovery and grade prediction results was verified.Graphical abstractGraphical abstract for this article
       
  • Characterization of mechanically alloyed and pressureless sintered
           Al-7 wt% Si-2 wt% LaB6-2 wt% (MoSi2, WSi2) hybrid composites
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Emre Tekoğlu, Yakup Yürektürk, Duygu Ağaoğulları, Didem Ovalı, Sıddıka Mertdinç, M. Lütfi ÖveçoğluThe purpose of this research is to investigate the dual effect of silicide (MoSi2 or WSi2) and LaB6 reinforcing particles on the microstructural and mechanical properties of Al-7 wt% Si (Al7Si) matrix. Hypoeutectic Al7Si blends prepared from elemental Al and Si powders were mechanically alloyed (MA’d) for 12 h in a planetary ball mill (at 300 rpm). Afterwards, 2 wt% silicide reinforcements (MoSi2 or WSi2) with various particle size distributions (micron, bimodal, submicron) were separately added into these MA’d Al7Si powders together with 2 wt% of LaB6 particles. Powders having compositions of Al7Si, Al7Si-2 wt% LaB6, Al7Si-2 wt% LaB6-2 wt% MoSi2 and Al7Si-2 wt% LaB6-2 wt% WSi2 were milled for 30 min using a high-energy ball mill (at 1200 rpm) in order to obtain homogeneous distribution throughout the microstructure. Compositional, microstructural and mechanical characterization studies were performed on the sintered samples. The results showed that high-energy ball milling ensured the homogeneous distribution of micron-sized MoSi2 and WSi2 particles within the matrix rather than those of bimodal and submicron-sized ones. Micron-sized MoSi2 and WSi2 reinforced hybrid composites displayed dramatically higher hardness and wear resistance than those of composites reinforced with different size of MoSi2 and WSi2 particles. The striking point of the study was the remarkably higher hardness and wear resistance properties of the hybrid composites compared to those of un-reinforced and only LaB6-reinforced ones. As a conclusion, hybrid composites extremely displayed promising mechanical properties.Graphical abstractGraphical abstract for this article
       
  • Synthesis and characterization of tantalum carbide nanoparticles using
           concentrated solar energy
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Yannely Carvajal-Campos, Laura Ceballos-Mendivil, Francisco Baldenebro-López, Carlos Pérez-Rábago, Claudio A. EstradaTantalum carbide (TaC) nanoparticles were synthesized using the IER-UNAM (HoSIER) solar furnace, which reduces polluting gas emissions and dependence on fossil fuels through the use of concentrated solar energy. TaC synthesis was performed through a carbothermal reduction method from Ta/O/C complex, using tantalum pentachloride (TaCl5) and synthesized phenolic resin as sources of tantalum and carbon, respectively, at a temperature of 1200 °C, in a reaction time of 30 min, under argon atmosphere. A solar reactor equipped with a quartz window was used, designed to work in controlled atmospheres. Complex Ta/O/C bonds and thermal decomposition were analyzed by FT-IR and TG/DSC, respectively, while the structure and morphology of TaC were analyzed by XRD, TEM, and SEM techniques. Results showed a TaC with a cubic crystalline structure, a low amount of Ta2O5 and a near-spherical morphology. According to Debye-Scherrer, the average crystallite size was 21 nm.Graphical abstractGraphical abstract for this article
       
  • Polymeric micropowders from thermal reversible crosslinking of oligomers
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Hansol Nam, Won-Ji Lee, Sang-Ho Cha, Kyung Jin LeePolymeric microparticles provide great potentials for applications originated from their high surface area and functionalities and thus have attained many attentions in various fields. Here, we attempt to fabricate polymeric micropowders based on the reversible thermal crosslinking (Diels-Alder reaction). Initially, poly(FEEMA) obtained from the radical polymerization of furan functionalized monomer and partially crosslinked poly(FEEMA) respectively. The physical properties of base-polymer for fabrication of microparticles have changed in order to control thermal responsible property of final micro particles. Based on Diels-Alder reaction, microparticles in the size range of 200 nm–2 μm were successfully prepared using polymer precursors and cross-linker in oil-in-water emulsion. Controlling the molecular weight as well as crosslinked density of polymer precursors makes it possible to adjust the thermal properties (glass transition temperature and retro-Diels-Alder temperature) of the microparticles. These series of method can provide thermal triggered, selective meltdown microparticles for several application fields such as selective gluing, patching, filling or healing by applying external heat.Graphical abstractPolymeric micropowders cross-linked by thermally reversible cross-linker were prepared from well-designed furan containing polymer precursors and via step-polymerization using bismaleimide as a crosslinker in oil-in-water emulsion. The thermal properties of microparticles (glass transition temperature, retro-Diels-Alder temperature) can be readily controlled by adjusting properties of polymeric precursors.Graphical abstract for this article
       
  • Research on mine dust suppression by spraying: Development of an
           air-assisted PM10 control device based on CFD technology
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Huitian Peng, Wen Nie, Haiming Yu, Weimin Cheng, Peng Bai, Qiang Liu, Zhiqiang Liu, Shibo Yang, Changwei Xu, Yun Hua, Cheng Guo, Qingxin MaIn order to solve the serious pollution problem of PM10 in a fully mechanized mining face, focusing on the drum cutting process which produces the most dust, a new type of shearer sprayer is developed in the paper. At present, it is difficult for a single spray device to meet the dust control demands of a mine. Therefore, in combination with the airflow-carrying-droplet mechanism, a fan is added to the shearer’s spray device to develop an air-assisted PM10 control device. A No. III nozzle is optimally chosen following the spray experiments, and CFD software is used for a numerical simulation of the 4307 fully mechanized mining face of the Bailu Coal Mine. According to the airflow and spraying field distribution, it is observed that when the spray device’s pressure is 8 MPa, the spraying field’s microscopic parameters are more conducive to the settling of PM10 by the mist droplets. The PM10 data measured at 1#-3# measuring points of the 4307 fully mechanized mining face of the Bailu Coal Mine have shown that the best PM10 settling effect is at a spraying pressure of 8 MPa. The PM10 concentrations at 1#-3# measure points were reduced to 0.987 mg/m3, 0.405 mg/m3 and 0.262 mg/m3 respectively, with the dust control rate being above 90%. Thus the serious PM10 pollution problem in a fully mechanized mining face has been solved effectively.Graphical abstractThe air-assisted PM10 control device was designed. We optimized the nozzle according to the spraying field’s multi-characteristic experimental platform and verified through a spray experiment – CFD numerical simulation. Then, we obtained the distribution law of spraying field and the best spray parameters of the air-assisted PM10 control device by CFD simulation. The test was carried out on the 4307 fully mechanized mining face, and the dust concentration was measured and analyzed.Graphical abstract for this article
       
  • Simulation analysis and engineering application of distribution
           characteristics about multi-stage atomization field for cutting dust in
           fully mechanized mining face
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Wenjing Yin, Gang Zhou, Danhong GaoTo improve the dust suppression efficiency of the external spray systems of shearers, a dust reduction method consisting of shearer external multi-stage atomization and dust removal fan was proposed. Computational fluid dynamics-based numerical simulation was combined with atomization experiments to analyze the migration and distribution of the cutting dust and multi-stage atomization field under airflow at the 2307 fully mechanized mining face of the Tangkou mine. The results show that with adding dust removal fan and multi-stage atomization points, the peak area of wind speed appeared on both sides of the shearer, and the wind speed was greater than 2.7 m/s, the dust concentration on the downside side of the shearer decreased, the spray coverage area increased significantly, and the droplet concentration at the shearer drum was the largest, exceeding 0.05 kg/m3. According to the research results, the multi-stage atomization arrangement of single-fluid water nozzles of shearer was put forward, and the field application was carried out. Compared with the engineering application results of the single-stage atomization dust suppression system, the total dust reduction rate of the synergistic effect of multi-stage atomization external spray with dust removal fan for the shearer is 87.12%, which is 38.59% higher than that of the conventional single-stage atomization dust suppression system.Graphical abstractGraphical abstract for this article
       
  • Estimation of uncertainty of percentile values in particle size
           distribution analysis as a function of number of particles
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Tatsushi MatsuyamaIn the analysis of particle size distribution (PSD), evaluation of the uncertainty of the percentile values is often required. Both theoretical and data processing methods are applicable to estimate standard deviations of percentile values. In this paper, a theory, applicable both in paramedic and non-parametric ways, is introduced. As a practical example, theoretical results based on a lognormal distribution are compared to those obtained by bootstrap method. Excellent agreement is demonstrated between the theory and the direct data processing method.Graphical abstractGraphical abstract for this article
       
  • Ion reduction in iron oxide and oxyhydroxide nanoparticles during
           ultrasonic treatment
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): S.V. Stolyar, O.A. Bayukov, R.N. Yaroslavtsev, Yu.V. Knyazev, V.P. Ladygina, Yu.V. Gerasimova, R.S. IskhakovThe effect of ultrasonic treatment of iron oxide and iron oxyhydroxide nanoparticles (ferrihydrite nanoparticles synthesized by Klebsiella oxytoca microorganisms, ferrihydrite nanoparticles synthesized by a chemical method and hematite nanoparticles) is studied. Samples of nanoparticles were investigated using transmission electron microscopy, Mössbauer spectroscopy and X-ray diffraction methods. The formation of the α-Fe metal phase from nanoparticles of iron oxides and iron oxyhydroxides was detected. The metal phase is formed as a result of the reduction of iron ions during cavitation treatment. According to the experimental results, the presence of a protein or a polysaccharide component is necessary for the course of this reaction.Graphical abstractGraphical abstract for this article
       
  • Robust green synthetic approach for the production of iron oxide nanorods
           and its potential environmental and cytotoxicity applications
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): K. Ramar, A. Jafar Ahamed, K. MuralidharanA facile and eco-friendly green method has been developed for the synthesis of hematite nanorod-like architecture (G-Fe2O3 NRs) using the resin obtained from the stem of the banana flower (Musa Paradisiaca Linn). In this green hydrothermal synthesis, the resin played dual roles as oxygen source and as structure directing stabilizing agents, which followed the facile one-step process, and it is suitable for scaling up to large-scale synthesis. Various techniques were used to investigate the physicochemical properties such as structural, morphological, surface area, thermal, magnetic, band gap and lifetime properties of the green synthesised G-Fe2O3 NRs. Investigations of G-Fe2O3 NRs by electron microscopes showed the average length and girth of the NRs were ranging from 528 ± 173 nm and 72 ± 21 nm. Significant impact on the physicochemical properties by this green synthetic approach yielded concrete results in their catalytic activities overcoming major environmental concerns. Especially, our green catalyst showed better redox kinetics with the lesser over potential than the commercially available bulk counterparts upon evaluating the photoelectrochemical water splitting ability such as oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Moreover, the photocatalytic efficiency of G-Fe2O3 NRs was evaluated by solar induced photoreduction of dichromate [toxic hexavalent chromium Cr(VI) to sustainable harmless trivalent chromium Cr(III)] and degradation of malachite green (MG). Both the processes involve the photocatalytic conversion by sequential adsorption of analytes on mineral surface and the overall efficiency was achieved mainly due to the high surface area (59.87 m2/g) of the catalyst. The cytotoxicity studies indicate that G-Fe2O3 NRs possesses much potential to work against A-549 (lung cancer) cell line.Graphical abstractGraphical abstract for this article
       
  • Densification of pure magnesium by spark plasma sintering-discussion of
           sintering mechanism
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Ruifeng Liu, Wenxian Wang, Hongsheng Chen, Zhen Lu, Wei Zhao, Tingting ZhangIn this study, high-quantity pure magnesium was prepared by SPS, and the sintering densification mechanism was discussed by using numerical simulation and simultaneous experiment. Results show that a layer of dense magnesium oxide was formed at the surface of Mg particles, and the oxide reduction can be observed owing to the effect of oxide film removal in SPS. The high energy pulsed current flows preferentially through particle contact surfaces, which provides the conditions for the generation of micro-arc between particles and the temperature at the particles contact point can be up to 1979 °C. With the low pressure at the initial sintering stage, local high temperature induced by micro-arc makes the melting (even evaporation) appearance. At the same sintering temperature of 570 °C, the obvious difference in bending strength also demonstrates the significance of spark discharge in SPS. The formation process of sintering neck demonstrates that sintering process is the reflection of melting (even evaporation), diffusion and plastic deformation. In order to realize tiny area and high-quality connection between powder particles, an innovative powder sintering technology using high-frequency pulse electric current (High frequency pulse current assisted sintering) is proposed based on the enlightenment of the skin, proximity and arc discharge effect of high-frequency pulse current. This technology is also instructive for other alloys and engineering materials.Graphical abstractGraphical abstract for this article
       
  • Prediction of segregation behavior of binary mixture in a pulsed fluidized
           bed
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Kai Zhang, Shuai Wang, Yuxiang Tang, Yurong HeA three-dimensional simulation is carried out to investigate the impact of pulsation flow on segregation behavior of binary mixture in a fluidized bed via the multi-fluid model. The simulated results are compared against the experimental data. The impacts of pulsation frequency and operating condition on flow and segregation behavior of binary mixture are discussed. The results reveal that an excessive increase of pulsation frequency and operating temperature is not beneficial to the enhancement of segregation efficiency. The pulsation frequency plays a more important role in segregation efficiency under a small size discrepancy of binary mixture. Meanwhile, the effect of pulsed air flow waveform on segregation efficiency of particles is also analyzed.Graphical abstractGraphical abstract for this article
       
  • Mixed convection of non-Newtonian nanofluid in an H-shaped cavity with
           cooler and heater cylinders filled by a porous material: Two phase
           approach
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Zhixiong Li, Pouya Barnoon, Davood Toghraie, Reza Balali Dehkordi, Masoud AfrandIn the present problem, two-phase mixed convection of a non-Newtonian nanofluid in a porous H-shaped cavity is studied. Inside the enclosure there are four rotating cylinders, using the Boussinesq approximation, mixed convection is created. Nanofluid includes H2O + 0.5% CMC and copper oxide nanoparticles. The mixture model was used to model physical phenomena. Different aspect ratios were used in order to achieve the best heat transfer rate. The Darcy and Richardson numbers ranges are 10−4 ≤ Da ≤ 10−2 and 1 ≤ Ri ≤ 100 respectively. Also, the aspect ratio and dimensionless angular velocities of cylinders ranges are 1.4 ≤ AR ≤ 1.6 and −10 ≤ Ω ≤ 10 respectively. Streamlines and isotherm-lines contours have been obtained for the variation of Darcy and Richardson numbers, aspect ratio and angular velocity. The heat transfer rates have been obtained for various aspect ratios, Darcy and Richardson numbers, and the direction of the cylinder's rotation, and are compared with each other. The results show that the direction of cylinders rotation influences the strength and extent of the generation vortices. Also, the use of porous material in high permeability can be a good alternative to lowering the angular velocity of the cylinders and ultimately reducing the need for less energy.Graphical abstractGraphical abstract for this article
       
  • Three-dimensional periodic structures of gold nanoclusters in the
           interstices of sub-100 nm polymer particles toward surface-enhanced
           Raman scattering
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Ayumi Yahata, Haruyuki Ishii, Kosuke Nakamura, Kanako Watanabe, Daisuke NagaoRegularly ordered polymer nanoparticle (PNP) assemblies incorporating gold nanoparticle (Au NP) clusters into the PNP interstices were fabricated by a simultaneous deposition of PNPs and Au NPs on a glass substrate. Monodisperse PNPs with an average size of 66 nm were employed as a template in the co-assembly to create the sub-100 nm periodic Au nanostructures on the substrate. First, mono-layering of PNP array with incorporation of 14 nm Au NPs was performed by a drop-casting to examine the number ratio of Au NPs to PNPs for multi-layering. Absorption spectra of the mono-layered co-assemblies of PNPs and Au NPs were employed to characterize the clustered state of Au NPs in the interstices of mono-layered PNPs. The number ratio suitable for homogeneous incorporation of Au NPs clustered in the interstice was found to be ranged from 6 to 8 in the characterization. Then, multi-layered co-assemblies of PNPs and clustered Au NPs were fabricated by a vertical deposition method with the Au NP number ratio of 8 to PNPs. Lifting rate of the substrate on which the PNPs were deposited was varied in the vertical deposition method to tune the film thickness of NP co-assembly. A decrease in the lifting rate to 1 μm/s could thicken the film to 0.71 μm corresponding to 13 layers of PNPs, resulting in the fabrication of periodic structures of Au NP clusters with a high packing density. Signal-to-noise ratio in the Raman measurement using p-mercaptobenzoic acid as a target molecule was successfully enhanced by multi-layering of the co-assembly, indicating that Au NP clusters were homogeneously incorporated into the interstices of PNPs in the co-assemblies.Graphical abstractGraphical abstract for this article
       
  • Collision dynamics of wet particles: Comparison of literature models to
           new experiments
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Britta Buck, Stefan HeinrichCollision dynamics of wet particles are often investigated in literature, since their knowledge is important for the design and modeling of granular process involving liquid layers or moisture. Several models were already reported predicting rebound behavior of wet particles. However, most of them are either developed for a viscous dominant regime, neglecting capillary effects all together, or capillary effects are strongly simplified. This work summarizes the various models and compares them to new experimental results for liquids at small and moderate viscosities, to check for applicability also for these materials. Several discrepancies between experiments at small liquid viscosities and models were found and reasons for these differences are discussed. Mainly, the negligence or simplification of capillary forces regarding energy dissipation during the collision leads to an overprediction of rebound velocities compared to the experiments reported in this work. Furthermore, selection of appropriate models for viscous forces during wet particle collisions has to be conducted with care.Graphical abstractGraphical abstract for this article
       
  • Amine-impregnated MCM-41 in post-combustion CO2 capture: Synthesis,
           characterization, isotherm modelling
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Satyajit Mukherjee, Akshay, Amar N. SamantaIn this study, a composite mesoporous silica material MCM-41 (Mobil composite matter) is impregnated with monoethanolamine (MEA) as primary linear amine, benzylamine (BZA) as primary cyclic amine and N-(2-aminoethyl) ethanolamine (AEEA) as secondary diamine and the effects of amine loading, amine type, CO2 partial pressure and adsorption temperatures on the CO2 adsorption are investigated. The CO2 adsorption performances of MCM-41 and amine impregnated MCM-41 samples are studied up to 1 bar of CO2 partial pressure and the temperature range of 25–60 °C. The amine loadings (% impregnation) are optimized for maximum CO2 uptake. The materials are characterised using N2 adsorption/desorption isotherm, Fourier Transform Infrared (FT-IR) Spectroscopy, Thermogravimetric (TGA) and Elemental (CHNS) analysis. The materials have shown good structural and thermal stability. The MCM-41-40%AEEA, MCM-41-40%BZA and MCM-41-50%MEA samples are exhibited the CO2 adsorption capacity of 2.34 mmol/g (102.98 mg/g), 0.908 mmol/g (39.96 mg/g) and 1.47 mmol/g (64.69 mg/g) respectively. The CO2 uptake of MCM-41-40%AEEA is 3.5 times higher than that of in MCM-41 (0.68 mmol/g) and it is also the highest reported value as di-amine impregnated MCM-41. The results indicated that the adsorption capacities of the materials (MCM-41 and MCM-41-40%AEEA) are decreased with an increase of adsorption temperature in the range of 25–60 °C. The Freundlich, Langmuir, Sips and Toth isotherm models are used to correlate and predict experimental CO2 adsorption data. The Sips and Toth isotherm models are found to be better fitted with the experimental data. The isosteric heat of adsorption of MCM-41 and MCM-41-40%AEEA samples are also calculated from Van’t Hoff plot using iSorbHP-win instrumental analysis software in the experimental temperature range.Graphical abstractGraphical abstract for this article
       
  • Influence of clean air and inlet configuration on the performance of slit
           nozzle virtual impactor
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Muhammad Zeeshan Zahir, Ji-Eun Heo, Se-Jin YookA two-partitioned horizontal inlet was developed for improving the collection efficiency and minimizing the wall loss problem in slit virtual impactor. The two-partitions were provided to simultaneously supply both aerosol and clean air to the virtual impactor. Both numerical and experimental investigations were carried out on the developed inlet configuration by considering different flowrate ratios of aerosol to clean air. The horizontal inlet was helpful in reducing the cutoff diameter, whereas the clean air prevented the particle deposition on the virtual impactor walls. The performance of two-partitioned horizontal inlet was compared with the conventional vertical inlet configuration for PM2.5, PM5 and PM10 virtual impactors. All the operating conditions and geometric parameters, such as the inlet flowrate; the width of collection nozzle; the width, length and span of acceleration nozzle; and the distance between collection and acceleration nozzles, were kept the same and only the inlet configuration was changed. The major-to-total flowrate ratio was kept at 0.9 and minor-to-total flowrate ratio at 0.1. It was observed that by using the two-partitioned horizontal inlet configuration, the cutoff diameters for PM2.5, PM5 and PM10 virtual impactors, were reduced by 16%, 10% and 11%, respectively, while the wall loss of particles near the cutoff size in all three cases were reduced from 16% to about 1%.Graphical abstractGraphical abstract for this article
       
  • Synthesis and characterization of new nanosphere hybrid nanocomposite
           polyoxometalate@ceramic@polyaniline as a heterogeneous catalyst for
           oxidative desulfurization of real fuel
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Mohammad Ali Rezvani, Parvin RahmaniIn this manuscript, the catalytic oxidative desulfurization (CODS) was proceeded using PMoV@CuO@PAN hybrid nanocatalyst. The nanocatalyst was prepared by the composition of potassium salt of 11-molybdo-1-vanadophosphat (PMoV), copper oxide (CuO), and polyaniline (PAN). The samples were characterized through various methods like FT-IR, XRD, SEM, and EDX. Thiophene (Th), benzothiophene (BT), and dibenzothiophene (DBT) were selected as the target sulfur compounds for CODS of simulated fuel. The oxidation processes were conducted under different conditions to evaluate the effects of individual reaction variables, including reaction time, reaction temperature, and nanocatalyst dosage. Moreover, a kinetic study was carried out and the activation energies for CODS of Th, BT, and DBT were determined. The investigations on CODS of real gasoline revealed that the sulfur content was reduced from 0.4987 to 0.0246 wt% and the mercaptans concentration was lowered from 98 to 5 ppm. Based on experimental results, the PMoV@CuO@PAN nanocatalyst retained a high removal yield of DBT compound after five rounds of reaction cycles and can be used as a reusable hybrid heterogeneous nanocatalyst in CODS treatments.Graphical abstractGraphical abstract for this article
       
  • Effect of nonlinear thermal radiation on 3D magneto slip flow of
           Eyring-Powell nanofluid flow over a slendering sheet with binary chemical
           reaction and Arrhenius activation energy
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): S.R.R. Reddy, P. Bala Anki Reddy, Krishnendu BhattacharyyaAn analysis is performed to study the combined effects of nonlinear thermal radiation, Arrhenius activation energy, chemical reaction and heat generation/absorption on the steady three-dimensional magnetohydrodynamic flow of Eyring-Powell nanofluid flow over a slendering stretchable sheet with velocity, thermal and solutal slips. The prevailing partial differential equations are transmuted into coupled non-linear ordinary differential equations via with the suitable similarity transformations. The resultant non-linear coupled differential equations are solved numerically by using the R-K 4th order method along with shooting scheme. The results are calculated to measure the influence of sundry parameters on velocity, temperature, concentration, shear stress, temperature gradient and concentration gradient are presented graphically and in tabular form. It is noticed that the temperature is more impactable for higher values of radiative heat transport. The local Sherwood number decays exponentially for all the values of the chemical reaction parameter. We compared the present results for the limiting cases with previously published results, which has shown reliability and efficiency.Graphical abstractPhysical configuration of the problem.Graphical abstract for this article
       
  • Ag/AgCl-GO: A composite for degradation of Rhodamine B in dye wastewater
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Cuiling Ai, Sikai Yang, Fan Zhang, Xiangwen Shao, Junge XuAg/AgCl-GO composite was fabricated by deposition–precipitation method and photoplasmic reduction method at room temperature. The resulting products were characterized by XRD, XPS, SEM, TEM, Zeta potential and UV–Vis DRS. The results indicated that the samples were composed of Ag, AgCl and graphene oxide (GO). During the photoreduction, the crystallinity of Ag0 particles gradually increased with prolonging the time of UV irradiation, then remained stable after 90 min. The addition of GO had little effect on the crystal structure of Ag/AgCl, however, this reduced the particle size and enhances the dispersibility of the composite. After 100 min of visible light irradiation, the degradation efficiency of rhodamine B (RhB) reached 98.43%. Therefore, the Ag/AgCl-GO photocatalyst exhibited significant photocatalytic activity during the degradation of RhB under visible light.Graphical abstractSynthesis mechanism of Ag/AgCl-GO composites. A negatively charged group (OH, COOH, etc.) on GO adsorbs Ag+ in the solution under the action of electrostatic force. AgCl particles were supported on the thin layer of GO by adding the KCl dropwise. The generated electrons by the intrinsic excitation of AgCl migrated to its surface and were captured by Ag+ to form Ag0 under ultraviolet light.Graphical abstract for this article
       
  • Recyclable and highly efficient photocatalytic fabric of
           Fe(III)@BiVO4/cotton via thiol-ene click reaction with visible-light
           response in water
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Haisheng Zhang, Dan Yu, Wei Wang, Pin Gao, Lishan Zhang, Shan Zhong, Baojiang LiuIn this article, we designed a photocatalytic cotton fabric of Fe(III)@BiVO4/cotton via thiol-ene click reaction and achieved an enhanced photocatalytic performance and excellent recyclability under visible-light irradiation. The Fe(III)@BiVO4 and cotton fabric were modified with KH570 (including CC groups) and KH580 (including SH groups), respectively. Then, the Fe(III)@BiVO4/KH570 and KH580/cotton reacted and connected via thiol-ene click reaction, which can effectively solve its recyclability in practical application and realize ideal all-in-one structure. The as-prepared Fe(III)@BiVO4/cotton not only exhibited an excellent photocatalytic performance in reducing Cr(VI) to Cr(III), but also showed a remarkable performance in degradation of C.I. reactive blue 19 (RB-19) under visible-light. Meanwhile, various analysis technique were used to confirm the successful connection between Fe(III)@BiVO4 and cotton fabric via thiol-ene click reaction. Moreover, the photocatalytic mechanism was also discussed comprehensively in view of trapping experiments and ESR analysis.Graphical abstractThe process of synthesizing the Fe(III)@BiVO4/cotton fabric and the possible mechanism of reduction of Cr(VI) and oxidation of RB-19 under visible-light irradiation.Graphical abstract for this article
       
  • Superparamagnetic magnesium ferrite/silica core-shell nanospheres: A
           controllable SiO2 coating process for potential magnetic hyperthermia
           application
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Harinarayan Das, Nipa Debnath, Takashi Arai, Takahiko Kawaguchi, Naonori Sakamoto, Kazuo Shinozaki, Hisao Suzuki, Naoki WakiyaThe control of coating shell becoming important to improve the applicability of magnetic nanoparticles. Herein, we present the scalable technique for preparing MgFe2O4/SiO2 core-shell nanospheres with finely tuned shell thickness and their efficiency in magnetic hyperthermia heating agent. At first, MgFe2O4 dense nanosphere derived from one-step ultrasonic spray pyrolysis (USP) technique. Silica shells were then coated on the as prepared nanospheres with tunable thickness from 10 to 30 nm. We show that the thickness of this coating is finely controlled at allowing our proposed level by using the required amount of SiO2 precursor (SiC8H20O4)/acidic catalyst (HCl) ratio where the surface area of core nanospheres are significantly considered. X-ray diffraction reveals the cubic spinel ferrite structure of core particles with crystallite size 9.6 ± 1.8 nm and Fourier transform infrared spectrum analysis confirmed the formation of SiO2. The morphological observation clarified the uniform and smooth SiO2 shell where core-shell nanostructure is highly monodispersed in a liquid medium. M-H loops confirmed the superparamagnetic nature of all samples at room temperature. Significantly reduced ion release concentration in an aqueous solvent of the coated nanospheres compared with uncoated sample demonstrates the hermetically coating feature of dense SiO2. This MgFe2O4/SiO2 core-shell nanospheres with thine SiO2 shell (10 nm) shows effective heating rate in the operative region (
       
  • Particle conveying under microgravity in a vibrating vessel
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): C.X. Li, K.J. Dong, Y.S. Shen, A.B. YuThis paper presents a numerical study on the conveying of particles in a vibrating vessel under microgravity. Such a vessel is composed of parallel plates with sawtooth wavy surfaces, which are specifically designed to convey particles using simple vibration. The numerical model was validated by good agreement between the simulated and experimental results. Then the effects of key variables, including the vessel geometry, vibration amplitude and frequency and gravity level, were systematically investigated by a series of controlled simulations. The results confirm the optimised design from the previous experiments, and numerically demonstrate that using such a system a steady conveying operation can be achieved under microgravity. The convey rate is positively affected by the vibration amplitude and frequency in a complicated way, which cannot be simply described by the commonly used vibration intensity or velocity amplitude. The gravity level also has a significant effect on the convey rate when it is over 0.001g. The convey rate can be estimated by the product of the average solid fraction and velocity. And the effects of the variables can be better understood through the analyses on these two parameters. Finally, a predictive model is proposed to estimate the convey rate under different operational conditions. The findings are useful for the design of particle conveying techniques for outer space applications.Graphical abstractGraphical abstract for this article
       
  • Large eddy simulation of pulverized coal combustion in multi-burner
           system–effect of in-furnace blending method on NO emission
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Masaya Muto, Hiroaki Watanabe, Ryoichi KuroseLarge-eddy simulation (LES) is applied to a multi-burner pulverized coal combustion furnace in which three advanced low-NOx burners, each with a coal combustion capacity of approximately 100 kg/h, are vertically installed. The effects of an in-furnace blending method, in which different types of coal (high-fuel-ratio coal and low-fuel-ratio coal) are injected at each burner stage, on NO emission and unburned carbon fraction in fly ash are investigated. Pulverized Newlands coal and Tanito Harum coal that are classified as high-fuel-ratio coal and low-fuel-ratio coal, respectively, are used as fuels. The results indicate that oxygen is consumed rapidly and NO decreases near the burner from which the high-fuel-ratio coal is injected because the reducing atmosphere becomes dominant owing to the lack of oxygen. Further, the unburned carbon fraction decreases when low-fuel-ratio coal is injected from the upper burner because the residence time is longer for the combustion of high-fuel-ratio coal than when low-fuel-ratio coal is injected from the lower burner.Graphical abstractComparisons of contour distributions of gas temperature and NO mole fractions between simulations and experiments.Graphical abstract for this article
       
  • Characteristics of a single jet injected into an incipiently fluidized
           bed: A magnetic resonance imaging study
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): C.M. Boyce, A. Penn, M. Lehnert, K.P. Pruessmann, C.R. MüllerRapid magnetic resonance imaging (MRI) was used to characterize properties of a single central gas jet injected into a 3D gas fluidized bed under incipient fluidization conditions. Snapshots of both particle concentration and particle velocity are provided. The average jet height, oscillations in jet height and the size of bubbles breaking off from the jet increased with increasing jet velocity. The frequency of bubble breakoff from the jet decreased with increasing jet velocity. The jet height measurements are compared with various correlations in the literature, and the quantitative data provided here can be compared directly with that from numerical simulations and theoretical predictions for validation purposes.Graphical abstractGraphical abstract for this article
       
  • Simulation of coal pressurized pyrolysis process in an industrial-scale
           spout-fluid bed reactor
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Guanwen Zhou, Wenqi Zhong, Aibing Yu, Jun XieA three-dimensional Eulerian-Lagrangian model, facilitated with multiphase particle-in-cell (MP-PIC) method, was developed to simulate gas-solid flow and pyrolysis characteristics of coal (with the capacity of 500 thousand tons per year) in an industrial-scale spout-fluid bed reactor (H = 16.6 m and D = 3.1 m), aiming at providing guidance for industrial application of pressurized grade conversion of coal. The performance of the reactor and the effects of operating parameters such as coal feeding rate, semi-coke to coal ratio, and particle sizes were numerically investigated. It was found that the flow pattern in this case is a “jet in the fluidized bed with bubbling”. The raise of pressure has a positive impact on the spouting structure and the flow uniformly. The increase of the semi-coke to coal ratio is beneficial to the coal pyrolysis, but the improvement of the pyrolysis is limited and the number of particles in the reactor will be sharply increased. With the increase of particle sizes, the flow pattern in the pyrolysis reactor tends to be stable while the mixing effectiveness is getting worse. It is suggested that the particle size of the material should range within 0–6 mm.Graphical abstractGraphical abstract for this article
       
  • Preparation, formulation and deposition of mica flake supported cobalt
           oxide for nanostructured lithium ion battery anodes
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Alexandra Helmer, Anna Sophie Rink, Julian Esper, Yanlin Wu, Julien Bachmann, Robin N. Klupp TaylorWe describe the fabrication and morphological and electrochemical characterisation of lithium ion battery anodes whereby the active material is supported on flake-like microparticles. Using various physical analytical techniques we verify that nanostructured cobalt (II, III) oxide can be directly grown onto commercial titanium dioxide-coated mica flakes by a liquid phase oxidation route. We then investigate the formulation and deposition of this material along with carbon black in order to form electrodes. Here we consider two binder/solvent systems, one widely used based on polyvinylidene fluoride in N-methy-2-pyrrolidone, and one more recently identified based on sodium alginate in water. We show that the latter system is preferable for the formation of anodes using the cobalt oxide coated flake-like particles as it leads to a more homogeneous distribution of active and conductive material in the electrode. Using cyclic voltammetry and electrochemical impedance spectroscopy we show that this feature improves the access to active material and facilitates efficient charge transfer in the electrode while maintaining electrode integrity. Moreover, an electrode based on the alginate binder exhibited a high reversible specific capacity of 650 mAh/g along with 84.8% capacity retention after 70 cycles. Overall our study indicates the promise of including shape anisotropic particles such as microflakes in battery electrodes.Graphical abstractGraphical abstract for this article
       
  • A facile preparation of graphene/reduced graphene oxide/Ni(OH)2 two
           dimension nanocomposites for high performance supercapacitors
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Jie Tian, Qian Shan, Xianglu Yin, Wei WuA Ni(OH)2 composite with good electrochemical performances was prepared by a facile method. Ni(OH)2 was homogeneously grown on the hydrophilic graphene/graphene oxide (G/GO) nanosheets, which can be prepared in large scale in my lab. Then G/GO/Ni(OH)2 was reduced by L-Ascorbic acid to obtain G/RGO/Ni(OH)2. Caused by the synergy effects among the components, the G/RGO/Ni(OH)2 electrode showed good electrochemical properties. The G/RGO/Ni(OH)2 electrode possessed a specific capacitance as high as 1510 F g−1 at 2 A g−1 and even 890 F g−1 at 40 A g−1. An asymmetric supercapacitor device consisting of G/RGO/Ni(OH)2 and reduced graphene oxide (RGO) was installed and displayed a high energy density of 44.9 W h kg−1 at the power energy density of 400.1 W kg−1. It was verified that the G/GO nanosheets are ideal supporting material in supercapacitor.Graphical abstractGraphical abstract for this article
       
  • What dominates heat transfer performance of hybrid nanofluid in single
           pass shell and tube heat exchanger'
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): S. Anitha, Tiju Thomas, V. Parthiban, M. PichumaniInfluence of nanoparticle volume concentration and proportion on heat transfer performance (HTP) of Al2O3 – Cu/water hybrid nanofluid in a single pass shell and tube heat exchanger is analyzed. Multiphase mixture model is adopted to model the flow. Three-dimensional governing equations and associated boundary conditions are solved using finite volume method. The numerical results are validated with the experimental results. Results indicate that optimized nanoparticle volume concentration and proportion dominate HTP of hybrid nanofluid. Heat transfer coefficient and Nusselt number are monotonic increase functions of nanoparticle volume concentration and proportion. The percentage increase in heat transfer coefficient of hybrid nanofluid is 139% than water and 25% than Cu/water nanofluid. At higher Reynolds number, the increment in Number of Transfer Units (NTU) between water and hybrid nanofluid is close to 75%. Maximum enhancement in Nusselt number for hybrid nanofluid exceeds 90% when compared to nanofluid (Al2O3/Water nanofluid). Consequently, highest heat transfer performance is attained for hybrid nanofluid systems. Effectiveness of heat exchanger increases almost to 124% when hybrid nanofluid is employed. We show that it is higher than water as well (conventional coolant). Results are expected to be helpful in further industrial-scale deployment of nanofluids, which is an area that is currently relevant for ongoing academia-industry partnership efforts worldwide.Graphical abstractGraphical abstract for this article
       
  • Synthesis of (Sn,Zn)(O,S) bimetallic oxysulfide catalyst for the
           detoxification of Cr+6 in aqueous solution
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Osman Ahmed Zelekew, Dong-Hau Kuo, Hairus AbdullahHerein, we report the bimetallic (Sn,Zn)(O,S) oxysulfide nanocatalyst with a facile method. The Sn-based catalyst with the addition of Zn was synthesized with the proportions of 0, 20, 30 and 50% of Zn to Sn precursors for preparation. The catalysts were characterized by XRD, TEM, SEM XPS, and UV–vis instruments. The nanocatalysts were also tested for the detoxification of Cr+6. The Sn-20 catalyst with 20 M percent of Zn(Ac)2·2H2O showed an excellent performance for the induced photocatalytic reduction of Cr+6 under visible light irradiation at room temperature. The complete reduction of Cr+6 was achieved within 80 min by Sn-20 catalyst. However, 85.6, 97, and 94% of Cr+6 reductions were achieved within 80 min under visible light illumination by Sn-0, Sn-30, and Sn-50 catalysts, respectively. Hence, the bimetallic (Sn,Zn)(O,S) oxysulfide nanocatalyst will be a candidate and highly potential material for the detoxification of Cr(VI)-containing polluted water.Graphical abstractThe reduction reaction mechanism for Cr(VI) under visible light by Sn-20 catalyst.Graphical abstract for this article
       
  • Synthesis of monodispersed silver particles: Synthetic techniques to
           control shapes, particle size distribution and lightness of silver
           particles
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Kanetaro Sannohe, Tingli Ma, Shuzi HayaseThe purpose of this paper is to give process for preparing monodispersed silver particles with round shape having aspect ratio of 1, because the shape is suitable for preparing silver grids with fine pattern size. We found that the combination of gelatin and hydrazine gave the monodispersed silver particles with the aspect ratio of 1. Presence of the high molecular compounds is crucial probably because they are adsorbed on the surface of growing silver particles and control the uniform crystal growth. In addition, the relationship between these reaction conditions and the particle shape are discussed in detail.Graphical abstractGraphical abstract for this article
       
  • Active electrode materials of graphene balls and their composites for
           supercapacitors: A perspective view
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Chongmin Lee, Sun Kyung Kim, Hankwon Chang, Hee Dong JangIn recent years, supercapacitors have received considerable research attention for energy storage systems due to their high-power density, fast charge-discharge processes, and long cycle life. The superior performance of supercapacitors is considerably dependent on the electrode materials. Among electrode materials, graphene balls (GBs) and their composites have recently attracted strong interest. They are considered ideal for the fabrication of electrode materials because of their unique characteristics of large specific surface area and superior electric conductivity, which should make them very effective for use in supercapacitors. In particular, GBs and their microstructured composites have recently been proven promising candidates for supercapacitor electrodes. Their unique 3D morphology provides highly porous graphene structures for decoration with active materials. In this perspective, recent studies were highlighted and discussed that focus on GBs and their composites for the potential energy storage devices called supercapacitors, (i.e., electric double layer capacitors and pseudocapacitors).Graphical abstractGraphical abstract for this article
       
  • The effect of copper granules on interfacial bonding and properties of the
           copper-graphite composite prepared by flake powder metallurgy
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Manish Dixit, Rajeev SrivastavaThe study evaluates the effect of introducing Cu granules and control milling on the microstructure, interfacial bonding and mechanical properties including sintered density, hardness, compressive strength, flexural strength and electrical conductivity of Copper-Graphite (Gr) composite synthesize by flake powder metallurgy (Flake PM). It develops the flake composite particles by control mechanical alloying (MA) which further laminates over the refine granules surface. This encapsulation facilitates the strong interfacial bonding among the composite constituents during sintering. Results highlight that the 10% Cu granules in Cu-10Gr composite exhibit excellent mechanical properties. It increases the relative density, hardness, compressive strength, and flexural strength by 4.19%, 28.23%, 98.31%, and 11.8% respectively. However, the electrical conductivity increases by 6.73% (%IACS) for 15% of Cu granules in the Cu-10Gr composite. The improvements in the results are the synergistic coordination of dispersion homogeneity, surface integrity, work hardening, and the superior interfacial adhesion between composite powder and Cu granules.Graphical abstractGraphical abstract for this article
       
  • Numerical simulation of gas-solid flows in fluidized bed gasification
           reactor
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Akhilesh Kumar Sahu, Vasudevan Raghavan, B.V.S.S.S. PrasadA numerical model for simulating a fluidized bed gasifier should include appropriate parameters to capture the dynamics of gas-solid flows, gasification kinetics and the interaction between these two. The focus of the present study is to analyze the effects of coal gasification chemistry models reported in literature on the prediction of product gas composition in a fluidized bed gasification reactor. Numerical results are validated against the experimental data available in literature. The validated model is used to examine the available chemical kinetics schemes for water gas shift reaction, steam methane reforming reaction and char heterogeneous reactions. It is also used to assess the effects of hydrodynamic models parameters such as drag model, particle-particle restitution coefficient and specularity coefficient on exit gas composition. Results show that the predictions of product gas composition are notably affected by the choices of the kinetics schemes for water gas shift and steam methane reforming reactions. Systematic analysis using the available choices to simulate initial processes such as moisture removal, volatile and tar cracking is reported. Drag models and the value of specularity coefficient are shown to have no effect on product gas composition, and the particle-particle restitution coefficient slightly influences the predicted gas composition.Graphical abstractGraphical abstract for this article
       
  • Development of the fumed TiO2 having high content of rutile structure and
           dispesibility using the dry-type of surface modification and the thermal
           treatment
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Yukiya Yamashita, Masayoshi FujiThe effect of dry-type surface modification of a fumed TiO2 and the thermal treatment were studied to synthesize the new fumed TiO2 having a high content of rutile structure and high dispersibility. The fumed TiO2 was modified with various metallic alkoxides to prepare precursors and next the resulted precursors were thermally-treated by the novel natural dropping method with a very short heating time, less than 1 s. The focus of this investigation was on the metallic alkoxide species as a surface modification agent and morphologies of both the precursor and thermally-treated fumed TiO2. The morphologies and nanostructures of the obtained fumed TiO2 were characterized. The carbon content and agglomerate of the precursor influenced on the transformation ratio from anatase to rutile structure. It was confirmed that the dry-type surface modification with tetraethoxysilane (TEOS) and titanium tetra-isopropoxide (TTIP) at room temperature is very effective method to prepare precursors for the next thermal treatment. The thermally-treated fumed TiO2 modified with TTIP showed 100% rutile structure with pure TiO2 composition at 1400 °C. The thermally-treated fumed TiO2 modified with small quantities of TEOS exhibited both 100% rutile structure and excellent dispersibility. This high dispersibility caused from a sponge-like structural characteristic of the agglomerate and static electricity repellence by coated SiO2 layer. The thermally-treated fumed TiO2 modified with TEOS and TTIP showed the color tone shift can be attributed to rutile structure. It was revealed that the combination of dry-type surface modification and natural dropping thermal treatment is an attractive method to prepare the new fumed TiO2 with 100% rutile structure maintaining the high dispersiblity.Graphical abstractGraphical abstract for this article
       
  • Simulation on coal-fired supercritical CO2 circulating fluidized bed
           boiler: Coupled combustion with heat transfer
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Ying Cui, Wenqi Zhong, Jun Xiang, Guoyao LiuUsing supercritical carbon dioxide (S-CO2) as the working fluid integrated in a circulating fluidized bed (CFB) boiler is a rising technology used to improve the power generation efficiency and reduce gas pollutant emissions in coal-fired power generation systems. This study established a comprehensive 3-D model based on an Eulerian-Lagrangian frame to simulate the combustion process. A new method was presented using constant heat flux as the boundary obtained from the coupled simulation of heat transfer and combustion. The gas phase was described with large eddy simulation (LES). The solid phase used the multi-phase particle-in-cell (MP-PIC) approach. Simulations were carried out in a 10 MW S-CO2 CFB boiler (with cross section area of 3.557 × 3 m2 and height of 21.01 m). Combustion characteristics obtained in boundary heat flux and excess air ratio were numerically investigated. Results showed that the temperature profile was relatively uniform in the whole boiler and the furnace temperature increased with the increase of boundary heat flux. Emissions of CO2 and SO2 declined with the increase of boundary heat flux while CO emission increased. An increased excess air ratio caused a decrease in furnace temperature and the rise of CO and SO2. The characteristics of combustion and pollutant emissions were optimal with the heat flux at around 25–37 kW/m2 and an excess air ratio at 1.18–1.25.Graphical abstractGraphical abstract for this article
       
  • Refining single-crystalline epsilon iron oxide nanorods via
           low-temperature aging
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Ji Ma, Yunguo Wang, Kezheng ChenRefinement of ε-Fe2O3 phase in ε-Fe2O3/SiO2 composite powder is an urgent need in terms of its practical applications in high-density magnetic storage media. In this work, two types of refinement routes were employed for this purpose. It was found that short-time tempering treatment was not an ideal route for the refinement, because ε-Fe2O3 nanorods were ruptured to nanoparticles with an extremely wide size distribution, and their low coercivity of merely 1.0 kOe was not desirable for expected applications. By contrast, low-temperature aging route facilitated the formation of uniform ε-Fe2O3 nanorods with a length of about 200 nm and a width of about 40 nm. Because of their narrow size distribution and high crystallinity, these nanorods possessed large coercivity around 19 kOe, pronounced remanent squareness and prominent thermomagnetic behaviors, making them fairly desirable for further applications in magnetically-relevant field.Graphical abstractGraphical abstract for this article
       
  • Clusters identification and meso-scale structures in a circulating
           fluidized bed based on image processing
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Shangyi Yin, Wenqi Zhong, Tao Song, Ping Lu, Yuhang ChenTo understand the behaviors of particle clusters in the circulating fluidized bed (CFB), experiments were conducted with glass beads to acquire the image sequences of gas-solid flow on a CFB riser with a 100 mm × 25 mm cross-section and 3.2 m in length by adopting high-speed photography. An image multilevel thresholding approach using k-means algorithm was applied to perform image segmentation to identify clusters as well as core clusters in the riser, automatically. Cluster characteristics, such as the density and the number of clusters were obtained subsequently. The results show the image segmentation method based on k-means algorithm has made some improvement in terms of precision and systematicness for cluster identification. In addition, the internal structure of the cluster was analysed. Collectively, the cluster always consists of a dense core with highest solids holdup surrounded by a relatively dilute cloud with no clear boundary. High solids holdup enhances the cluster formation. On the contrary, the core cluster disappears at low solids holdup condition, indicating the cluster is only composed of cluster cloud in this case. Furthermore, based on the present experimental data, the correlations between the cluster density and the local time-mean solids holdup are presented.Graphical abstractParticle clustering behaviors in circulating fluidized bed riser are experimentally investigated by the high-speed video system. An image multilevel thresholding approach using k-means algorithm is developed to perform image segmentation to identify the cluster as well as its internal structure. Additionally, the dynamics properties of particle clusters are discussed.Graphical abstract for this article
       
  • Coupled DEM-SPH simulations of wet continuous screening
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Darius Markauskas, Harald Kruggel-EmdenDuring screening, a liquid stream, besides the vibration, can be applied for the acceleration of the separation. The discrete element method coupled with the smoothed particle hydrodynamics (DEM-SPH) is used to numerically analyse wet continuous screening here. Within the applied DEM-SPH a new simple model for the representation of the screening surface is suggested in this study. In this model, the influence of the screening surface on the fluid is represented using external forces, which act on the SPH particles in close vicinity of the screen. A required validation of the DEM-SPH method for the analysis of a vibrated particle-laden system is performed by comparing obtained DEM-SPH results with the results derived using the DEM coupled with finite volume method. The performed simulations of dry and wet continuous screening demonstrate that flowing water, in most simulated cases, accelerates the separation of particles. The presented study demonstrates the potential of the coupled DEM-SPH method for the analysis of wet screening processes. To our best knowledge, the simulation of wet screening using a two-way coupled numerical DEM-SPH approach not resolving the flow around individual particles is demonstrated in the scientific literature for the first time.Graphical abstractGraphical abstract for this article
       
  • Diffusion mechanism and release profile of a multivitamin from
           TiO2 hollow particles
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Yoko Tominaga, Kazunori Kadota, Akira Kitayama, Atsuko Shimosaka, Mikio Yoshida, Yoshiyuki ShirakawaThe present study aimed to control the release rate profile of a multivitamin that has hydrophilic and hydrophobic properties and to investigate its diffusion rate from titanium dioxide (TiO2) hollow particles. The TiO2 hollow particles encapsulating the vitamins C and E were prepared via a sol-gel process using an inkjet nozzle. The obtained particles were evaluated by scanning electron microscopy and energy dispersive X-ray spectroscopy. The sustained release rate was estimated by the dialysis bag method. Additionally, a diffusion mechanism for the multivitamin from the TiO2 hollow particles was proposed.TiO2 particles prepared by this method exhibited spherical porous structures. The TiO2 hollow particles were successful in encapsulating both the hydrophilic vitamin C and the hydrophobic vitamin E, resulting in a sustained release profile for these two components from the TiO2 hollow particles. The release behavior of the multivitamin was quite different from that of each single vitamin. This is related to the adsorption state of each vitamin on the TiO2 particle surface. The effective diffusion coefficient of VC derivative (8.403 × 10−13 cm2/s) was faster than that of VE derivative (1.671 × 10−13 cm2/s). This tendency may be attributed to the difference between hydrophilic and hydrophobic properties. Additionally, the value of effective diffusion coefficient in multi-component was always larger than that in single component. The value of Knudsen diffusion coefficient in VC and VE derivative was 2.684 × 10−3 and 2.264 × 10−3 cm2/s, respectively. In all samples, Knudsen diffusion coefficient was larger than molecular diffusion coefficient. The diffusion mechanism of the active ingredients likely depends on the pore size of TiO2 and the molecular size of the active ingredients.Graphical abstractGraphical abstract for this article
       
  • Time-dependent evolution pathway of CIGSe nanocrystals by low-temperature
           process
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): M. Latha, R. Aruna-Devi, S. Velumani, Jaime Santoyo-Salazar, F. de Moure-FloresWe report a systematic time-dependent investigation of Cu(In0.7, Ga0.3)Se2 nanocrystals (CIGSe NCs) by the hot-injection process at low reaction temperature. The reaction time was varied from 0 min to 16 h, to study the reaction mechanism and growth process of CIGSe NCs. Structural analysis showed the formation of β-CuSe phase at 0 min and mixed phase of β-CuSe and CIGSe, when the reaction time was between 5 min and 4 h. The size of NCs was increased from 3 to 38 nm as the reaction time increases. The composition of Cu/(In + Ga) was decreased while Ga/(In + Ga) increased as a function of reaction time. Based on the results, the possible formation mechanism of CIGSe NCs was proposed. The sequence of CIGSe formation is initiated from binary β-CuSe and then the mixture of β-CuSe and CIGSe, which subsequently transferred to single phase CIGSe by gradual incorporation of In3+ and Ga3+ ions into the β-CuSe crystal lattice. Formation of single phase CIGSe with the optimum bandgap of 1.24 eV and targeted composition was obtained at 8 h. Additionally, thin films were prepared by drop casting of NCs ink. Single phase CIGSe NCs films showed significant improvement in the morphological, electrical and optoelectronic properties than other films, indicating their potential applicability in low-cost thin film solar cells.Graphical abstractGraphical abstract for this article
       
  • Flamelet modeling of laminar pulverized coal combustion with different
           particle sizes
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Xu Wen, Jianren FanIn this work, flamelet modeling of pulverized coal flame stabilized in a laminar counterflow is conducted. Particularly, the effects of particle size on the flamelet model performance are investigated. The a priori tabulated thermo-chemical quantities are compared with the corresponding values in the detailed chemistry solutions, which are obtained by solving the transport equations for all species mass fractions existing in the employed detailed chemical reaction mechanism. The detailed chemistry solutions show that the pulverized coal flame structure can be changed significantly by varying the particle size. While pulverized coal flame structure with small particles is similar to the pure gas flame, it becomes much more complex when the particle Stokes number is larger than unity. Large coal particles can directly cross the flame front to the opposite side and disperse over a large region, resulting a significantly wrinkled flame front and a considerably broadened reaction zone. Comparisons between the tabulated thermo-chemical quantities and the detailed chemistry solutions show that the CH4, O2 and H2O species mass fractions and their RMS (root mean square) values for all cases can be well predicted by the classical flamelet model without any modification, while the peak values of OH mass fraction, gas temperature and heat release rate for the large particle case cannot be correctly captured. For all cases, the mass fractions of combustion-mode-sensitive species cannot be correctly predicted in the premixed flame reaction zone by the employed diffusion-flame-based flamelet model. Such discrepancies are even more pronounced at large particle conditions since the premixed flame reaction zone tends to be broadened.Graphical abstractGraphical abstract for this article
       
  • Relationship between water distribution and shear properties of wet
           granules
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Takumi Kusano, Masaaki Tani, Osamu Hiruta, Hiroshi NakamuraWet granules are utilized in various fields due to their high workability and cost performance. However, it is difficult to observe the water distribution of wet granules directly because such granules only contain extremely small amounts of water. In this study, the water distribution of wet granules was investigated using a confocal laser microscope and quantitatively analyzed using an autocorrelation function. Furthermore, the correlation length of wet granules estimated from the autocorrelation function was compared with the shear properties of the granules. Consequently, it was found that the internal friction angle of wet granules decreased as the water volume between particles increased. These results indicated that the water in wet granules works as a drag reduction agent under shear conditions.Graphical abstractGraphical abstract for this article
       
  • Synthesis of porous Mg-doped CeO2 powders via self-propagating
           high-temperature synthesis route
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Zahra Hashemzaei, Mahmood Sharifitabar, Hamideh Saravani, Meissam NoroozifarThe aim of this study was synthesis of Mg-doped porous cerium oxide powder by self-propagating high-temperature synthesis reaction of Mg-xCeO2-O2 system. Results indicated that doping Mg in the CeO2 crystal structure increased its lattice parameter slightly, and shifted the Ce-O band in the FTIR spectra from 490 to 574 cm−1. Moreover, the EDS results revealed the distribution of Mg in the CeO2 microstructure. There were a high volume fraction of interconnected macro-pores in the microstructure of cerium oxide after the synthesis process. Increase in the x-value from 0.05 to 0.25 mol decreased the mean size and volume fraction of pores from 2.4 to 1 µm and 50 to 30 vol%, respectively. In addition, the BET surface area of porous CeO2 varied between 0.3 and 1.57 m2/g. Finally, it was inferred that the SHS technique can be introduced as a rapid and novel method for synthesis of Mg-doped porous CeO2 powders.Graphical abstractGraphical abstract for this article
       
  • Fluidization using pseudoplastic liquids – Elutriation and ANN
           modeling
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Samit Bikas Maiti, Nirjhar Bar, Sudip Kumar DasExperimental work on elutriation of irregularly shaped sand particles (0.538–2.03 mm diameter) was carried out in three different Perspex columns (47 mm, 72 mm and 92.3 mm) using different non-Newtonian pseudoplastic liquids (0.4–0.8 kg/m3 SCMC solution). The effects of operating parameters, column diameter, bed weight, particle diameter, particle sphericity, liquid rheological properties on the minimum elutriation velocity were examined. The statistically accepted empirical correlation was developed. ANN model could predict the experimental data of minimum elutriation velocity with a correlation coefficient of 0.9951.Graphical abstractGraphical abstract for this article
       
  • Cold-pressing and vacuum arc melting of γ-TiAl based alloys
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): M.N. Mathabathe, A.S. Bolokang, G. Govender, C.W. Siyasiya, R.J. MostertBeta (β) solidifying γ-TiAl intermetallic alloys of nominal composition Ti-48Al, Ti-48Al-2Nb, Ti-48Al-2Nb-0.7Cr alloys have been cold pressed and vacuum arc melted. The Al loss was due to compaction method used prior to the melting technique, since it was evident after compaction that Al particles migrated to the surface in contact with the die facets after cold pressing. Electron backscatter diffraction (EBSD)-orientation mapping demonstrated that the α-precipitation from the parent β-phase follows the Blackburn orientation relationship (BOR). Microstructural characterization of the alloys was studied by scanning electron microscopy (SEM) equipped with energy dispersion spectroscopy (EDS) for micro-analysis. X-ray diffraction (XRD) technique was used to detect phase compositions.Graphical abstractGraphical abstract for this article
       
  • Template-assisted spray-drying method for the fabrication of porous
           particles with tunable structures
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Asep Bayu Dani Nandiyanto, Takashi Ogi, Wei-Ning Wang, Leon Gradon, Kikuo OkuyamaDeveloping strategies for the production of porous particles with controllable structures using a spray-drying method has attracted attention of researchers for decades. Although many papers have reported their successful production of porous particles using this method, information on how to create and control the porous structures as well as what parameters involving and what formation mechanism occurring during the synthesis process are still not clear. To meet these demands, the present review covers strategies in the spray-drying developments for the fabrication of porous particles with controllable structure. This information is important for optimizing the production of porous particles with desirable properties. Regulation of process conditions and precursor formulations are also explained, including composition, type, and physicochemical properties of droplet and raw components used (i.e., host component, template, and solvent). The electrostatic interactions between the individual components and the droplets are also presented, while this information tends to be neglected in the conventional spray-drying process. To clarify how the porous particles are designed, current experimental results completed with illustrations for the proposal particle formation mechanism are presented. The review also completed with the opportunities and potential roles of the changing porous structures in practical uses. This review would provide information on how to produce porous particles that can be used for advanced functional materials, such as catalysts, adsorbents, and sensors.Graphical abstractGraphical abstract for this article
       
  • A facile preparation of pomegranate-like porous carbon by carbonization
           and activation of phenolic resin prepared via hydrothermal synthesis in
           KOH solution for high performance supercapacitor electrodes
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Jianbing Zang, Pengfei Tian, Guoping Yang, Shaopei Jia, Shuyu Zhou, Hanqing Xu, Yanhui WangHigh electrochemical performance pomegranate-like porous carbon was synthesized by the carbonization and activation of phenolic resin which was prepared by adding phenolic resin monomer mixture into KOH aqueous solution and hydrothermal treatment. In the process of hydrothermal, KOH solution could hinder the polymerization of phenolic resin monomer to form big phenolic resin particles. During the carbonization, phenolic resin plays the role of forming small particles and binder during carbonization, which can simultaneously achieve high specific surface area and form three dimensional structures to improve the conductivity. The results showed that pomegranate-like porous carbon composed of small nanometer-scale particles was observed. The obtained porous carbon electrode materials had a high content of micropores with specific surface area as high as 2199.9 m2 g−1. The porous carbon exhibited a high specific capacitance of 341.3 F g−1 at 0.1 A g−1, good rate capability with 71.0% retention from 0.1 to 5 A g−1. Moreover, it showed high capacitance retention of 96.1% after 5000 cycles at a scan rate of 50 mV s−1, indicating excellent cycling stability. The assembled symmetrical supercapacitor showed high energy densities of 17.0 Wh kg−1 and 8.5 Wh kg−1 with the corresponding power densities of 49.6 W kg−1 and 1.8 kW kg−1, respectively. The facile method could be a promising candidate for preparing porous carbon electrode materials with excellent electrochemical performance in the fields of supercapacitors.Graphical abstractGraphical abstract for this article
       
  • Catalytic peroxygen activation by biosynthesized iron nanoparticles for
           enhanced degradation of Congo red dye
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Gautham B. Jegadeesan, S. Amirthavarshini, J. Divya, G.I. GunaraniIn this study, biogenic iron (Fe) NPs (B-Fe) were synthesized using Terminalia Bellirica plant extracts and used to activate persulfate (PS) and peroxymonosulfate (PMS) oxidants for degradation of Congo red (CR) dye. Chemogenic Fe-NPs (C-Fe) were also synthesized using borohydride reduction method for comparison. The synthesized Fe NPs were characterized for their surface morphology using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS)-based particle size analysis. Biogenic B-Fe NPs were more uniform in size and smaller (67–125 nm), compared to chemogenic C-Fe (59–277 nm), due to the capping effect of the biomolecules in plant extracts. Degradation efficiencies using the nanoparticle – oxidant system followed the order: C-Fe-PMS (86%) ∼ B-Fe-PMS (83%) > C-Fe-PS (75%) > B-Fe-PS (63%). Post-degradation UV–Vis absorbance spectra indicated the absence of intermediates in the PS/PMS systems, suggesting complete mineralization of the dye. The kinetics of the process is best described by shifting order rate kinetics. Alkaline pH conditions, low oxidant loading and high initial dye concentration hindered degradation kinetics, while catalyst loading had minimal impact on the oxidation process. The data strongly suggested that biogenic Fe NPs activated oxidant system is an effective alternative to existing hydroxyl – radical based advanced oxidation processes.Graphical abstractGraphical abstract for this article
       
  • Tensile strength of cohesive powders
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Pablo García-Triñanes, Stefan Luding, Hao ShiMeasurement and prediction of cohesive powder behaviour related to flowability, flooding or arching in silos is found to be very challenging. Previous round robin [52] attempts with ring shear testers did not furnish reliable data and have shown considerable degrees of scatter and uncertainty in key measurements. Thus studies to build a reliable experimental database using reference materials are needed in order to evaluate the repeatability and effectiveness of shear testers and the adopted procedures.In this paper, we study the effect of particle size on the yield locus for different grades of limestone (calcium carbonate). We use the nonlinear Warren Spring equation to obtain the values of cohesion C, tensile strength T, and the shear index n. We recover linear (n = 1) yield loci for d50>70 μm with respectively small C and T, with consistent, finite macroscopic friction C/T = 0.7. With particle size decreasing below 70 μm the response becomes more and more cohesive and non-linear (1
       
  • Controllable preparation of antimony powders by electrodeposition in
           choline chloride-ethylene glycol
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Jiaojiao Bu, Juanjian Ru, Zhiwei Wang, Yixin Hua, Cunying Xu, Yuan Zhang, Yun WangAntimony powders with different morphologies have been prepared by electrodeposition at 313–353 K and 10–50 mA·cm−2 in 0.1 mol·L−1 SbCl3 + ChCl-EG solution. The electrochemical behavior of Sb(III) on titanium electrode are studied by cyclic voltammetry. Results show that the electrochemical reduction of Sb(III) in SbCl3 + ChCl-EG solution is a quasi-reversible process via a one-step reaction and the apparent activation energy is 50.723 kJ·mol−1. The effects of current density and temperature on current efficiency and specific energy consumption are also investigated. The current efficiency increases with the increasing of current density and temperature. The specific energy consumption increased with the increase of current density, while decreased with the raising of temperature. When the current density is 40 mA·cm−2 at 353 K, the current efficiency and specific energy consumption are up to 97.89% and 1251.277 kW·h·t−1, respectively. The morphology and phase of the products are analyzed by FESEM and XRD. It demonstrates that the deposition products are pure antimony powders and their preferred crystal plane is (0 1 2). The pineal, wheat grain, badminton, dendritic, and cluster-like antimony powders can be prepared by controlling electrodeposition parameters. The particles size range of antimony powders are 0.21–261.05 μm.Graphical abstractGraphical abstract for this article
       
  • Control of particle charge by atmospheric pressure plasma jet (APPJ): A
           review
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s): Shuji MatsusakaAtmospheric pressure plasma jets (APPJs) have more advantages regarding flexibility of operation than low pressure plasmas. Because the ions and/or electrons in the APPJ can be arbitrarily extracted to a gas-phase space by changing the DC bias voltage and efficiently deposited onto particle surfaces in an external electric field, this operating technique can be applied towards controlling particle charge. Several methods to control the particle charge using an APPJ system have already been reported. This article summarizes the specifications and operations of these systems, their mechanisms of charge transfer, and methods for particle charging, based on previously reported work. The methods are categorized into three groups, i.e., direct charging of particles, direct charging of a powder bed, and indirect charging of particles, and the corresponding experimental setups, procedures, results, and discussions are presented.Graphical abstractGraphical abstract for this article
       
  • Full title (Editorial Board Members)
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s):
       
  • Inside Front Cover (Aims & Scope, Editors)
    • Abstract: Publication date: December 2019Source: Advanced Powder Technology, Volume 30, Issue 12Author(s):
       
  • Experimental investigation on the packed bed of rodlike particles
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Wenguang Nan, Yueshe Wang, Houhuan SunRodlike particles have been usually found in industrial applications, such as the straw and needle catalyst in energy and chemical engineering. Compared to spherical particles, rodlike particles exhibit different behaviour in the packing structure due to their rotational movement. In this work, we have experimentally explored the packing structure and its friction factor for fluid flow. The porosity of packing structure generated by two packing methods is measured for four kinds of rodlike particles. The experimental results show that the porosity of bed of rodlike particles in the poured packing is not a monotonic function of the aspect ratio of particles. This is due to the competition between the “self-fitting” effect and excluded effect. The porosity of bed of rodlike particles is more sensitive to the packing method than that of spherical particles. To describe the pressure drop of fluid flow through the packing structure, the Ergun equation is further modified by introducing the modified Reynolds number and Galileo number. By combing the experimental data for packed bed generated by the fluidised packing method, and other experimental work in current literature, a new empirical equation is proposed to predict the friction factor of the packing structure of rodlike particles, in which the effects of the particle orientation and particle shape are both considered by the equivalent sphericity. These experimental results would be of interest from applied standpoints as well as revealing fundamental effects of the aspect ratio of rodlike particles on the packing structure.Graphical abstractGraphical abstract for this article
       
  • Effect of level of overflow solid outlet on pressure drop of a bubbling
           fluidized-bed
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Daewook Kim, Gyoung Woo Lee, Yoo Sube Won, Jeong-Hoo Choi, Ji Bong Joo, Ho-Jung Ryu, Sung-Ho JoThe effect of level of the overflow outlet for continuous flow of solid particles on the pressure drop of a bubbling fluidized-bed that employed an in-bed inlet for solid feed was investigated with changing solid properties, solid feed rate, gas velocity, and level of the overflow outlet. The pressure drop of fluidized-bed (Δpbed,f) decreased with increasing gas velocity, but increased with either solid feed rate or level of the overflow solid outlet (L). The Δpbed,f/L increased with L. Irrespective of particle size and density, bed height converted for minimum fluidization condition (pressure head by bed weight, Hmf,f) decreased with increasing the volume flow rate of bubble but increased with either the solid feed rate or the level of the overflow solid outlet. The nominal vertical height, height between the Hmf,f and the level of the overflow outlet, that bubbles transported particles while drawing the solid particles out of the fluidized-bed increased as either the volume flow rate of bubble or level of the overflow outlet increased. However, it decreased as the solid feed rate increased. It appeared that the power of bubble for lifting solid to be discharged through the overflow outlet was same at the fixed volume flow rate of bubble, solid feed rate, and level of the overflow solid exit. The power of bubble increased with the level of the overflow outlet but not linearly. The correlation proposed for the pressure drop across the bubbling fluidized-bed was useful to predict the pressure drop across the recycle chamber of the loop seal and the external solid circulation rate in the circulating fluidized-bed system.Graphical abstractEffects of solid feed rate and level of overflow solid outlet on pressure drop of bubbling fluidized-bed.Graphical abstract for this article
       
  • Effect of temperature-related factors on densification, microstructure and
           mechanical properties of powder metallurgy TiAl-based alloys
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Dongjun Wang, Honggang Zhao, Wei ZhengIn the present work, the influence of temperature-related factors, including sintering temperature, heating step and temperature-control mode, on the densification, microstructure and mechanical properties of Ti-46.5Al-2.15Cr-1.90Nb-(B, Y, Mo) alloys prepared by SPS has been investigated and discussed in detail. The results obviously indicate that the sintering temperature plays a key role on densification and phase transition, when compared with the heating step and temperature-control mode. Based on the experimental results and theoretical analysis, the densification process and microstructural evolution of TiAl-based alloys during sintering are studied. Moreover, the mechanical properties of the sintered alloys are determined by the combined effects of the densification and microstructure. The obtained results will help to optimize the microstructure and properties for this kind of intermetallic alloys through controlling sintering parameters during powder metallurgy process.Graphical abstractGraphical abstract for this article
       
  • Ball-milling properties and sintering behavior of
           Fe-Tm2O3 mixture powders
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Yongshuai Mu, Guang Ran, Weisong Wu, Chao YeAimed at the existing problems of current neutron absorbers that were used in control rods to safely operate a nuclear reactor, new type of Fe-based Tm2O3 composites and Fe-based TmFeO3 composites, which were synthesized from the Fe-25.68 wt.%Tm2O3 mixture powders by ball milling, cold isostatic pressing and sintering, were designed as next generation neutron absorbers in the present work. During ball milling, Tm2O3 was fined, nano-crystallized, amorphized and then dissolved into Fe crystal lattice to form Fe (Tm, O) nanocrystalline solid solution. The effect of sintering temperature and oxygen content at sintering environment on the phases of the sintered bulks were researched, and the corresponding mechanism was discussed. Nanoscale TmFeO3 and Tm2O3 particles were distributed in the sintered bulk matrix. The microhardness, compression strength, and the coefficients of thermal expansion of the bulks sintered at different conditions were measured and discussed. The coefficient of linear expansion and compressive strength increased with increasing ball-milling time. The microhardness increased with increasing sintering temperature when the temperature was lower than 1200 °C. Meanwhile, the microhardness and compressive strength of Fe-based Tm2O3 composites were larger than that of Fe-based TmFeO3 composites, opposite for the coefficients of thermal expansion.Graphical abstractGraphical abstract for this article
       
  • The effect of ball milling on properties of sintered manganese-doped
           alumina
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): S. Filipović, N. Obradović, S. Marković, M. Mitrić, I. Balać, A. Đorđević, V. PavlovićAlumina-based compounds have many technological applications and attract great attention even after decades of investigation, due to their good chemical, electrical, and mechanical properties. A mixture of several alumina modifications (α-, κ-, γ-Al2O3) doped with 1 wt% of Mn2O3 was used for this experiment. The powder was mechanically activated for 60 min in an ethanol medium. After compaction, green bodies were sintered in the temperature range from 1200 to 1400 °C. Microstructures of the obtained specimens were investigated by scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The influence of morphological changes on electrical and mechanical properties was examined in detail. We have developed a test fixture and corresponding software for measurement of the relative dielectric permittivity and the loss tangent of ceramic specimens. This new method overcomes the problems of dimensions and shape of samples, as well as the problem of applying silver paste. The accuracy is around 2% for ε'r and 0.003 for tanδ. We demonstrate that the mechanical activation (MA) has the dominant influence on lowering the characteristic temperatures and microstructure development, which further leads to increased permittivity and tensile strength.Graphical abstractInfluence of mechanical activation, in wet media, on relative dielectric permeability was measured using new method of collecting and processing of data.Graphical abstract for this article
       
  • CO2 pretreatment and hydrothermal treatment of commercial γ-Al2O3 powders
           for purification and refinement
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Min Gao, Ping Zhao, Benxue Liu, Xibin Yi, Yue XuUltrapure, nanosized alumina (Al2O3) powders are highly required for high performance Al2O3 ceramics. However, the synthesis of the powders via an efficient and low-cost way is still a challenge. In the present research, we treated commercial γ-Al2O3 powders via hydrothermal treatment combined with CO2 pretreatment technique. The effect of hydrothermal pressure on the crystal phase, particle size and purity of the treated powders were investigated. In addition, the effect of CO2 pretreatment on the purification of the powders was discussed. Commercial γ-Al2O3 powders are fully converted to boehmite (AlOOH, a derived form of Al2O3) at a hydrothermal pressure of 3.5 MPa. The boehmite powders reduce to the minimum particle size of 50–100 nm after being hydrothermal treated at 3.5 MPa. CO2 pretreatment has been found to be very efficient in the purification of the powders. The Al2O3 content of the powders after being CO2 pretreated at 1 MPa could reach up to 99.9410% which is much larger than that of commercial γ-Al2O3 powders (99.5096%). The as-received ultrapure, nanosized boehmite powders are promised raw materials for high performance Al2O3 ceramics.Graphical abstractGraphical abstract for this article
       
  • Analysis of grinding kinetics in a laboratory ball mill using
           population-balance-model and discrete-element-method
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Hansol Lee, Kwanho Kim, Hoon LeeGrinding processing consumes a lot of energy in mineral processing, but it is a low-efficiency process in which only approximately 1% of the total energy is used to reduce the actual particle size. Therefore, an efficient operation in the grinding process increases the competitiveness of the production and is an essential for enhancing the energy efficiency of the entire mineral processing procedure.Therefore, the study will focus on to finding a different method to predicting the particle size distribution of the ball mill, by using the PBM which reflects the actual size distributions of ground product and the DEM which can understand the internal particle behavior in the mill chamber. First, the grinding parameters were calculated by applying size distributions of ground product under various conditions to PBM and the behaviors of the particles inside the ball mill obtained through DEM were analyzed to predict the distribution of the impact energy used for grinding. Next, the relational expression between the grinding rate parameter and the normal force applied to the grinding materials was derived. Using the relational expression derived from this study, it was confirmed that the size distributions in other conditions can be predicted.Graphical abstractGraphical abstract for this article
       
  • CFD analysis of employing a novel ecofriendly nanofluid in a miniature pin
           fin heat sink for cooling of electronic components: Effect of different
           configurations
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Mehdi Bahiraei, Saeed Heshmatian, Marjan Goodarzi, Hossein MoayediThis research aims to study the thermal and hydraulic attributes as well as energy efficiency of a new ecofriendly nanofluid including functionalized graphene nanoplatelets in a mini heat sink with three different pin fins. The circular, triangular and drop-shaped pin fins are investigated and compared with each other. The effects of nanoparticle fraction and flow velocity on the thermal resistance, temperature uniformity, convective heat transfer coefficient, maximum surface temperature, average surface temperature, pressure loss and pumping power are assessed. Increasing the concentration or velocity reduces the temperature on the heated wall, and also improves the temperature distribution uniformity. At both constant velocity and invariant pumping power, the heat sink fitted with the circular pin fins leads to the best performance while that equipped with the triangular pin fins results in the worst efficiency. In addition, the Figure of Merit (FoM) is greater than 1 for all conditions, which proves that the nanoparticle suspension possesses a greater merit to be employed as the coolant in the heat sinks compared to the base fluid.Graphical abstractGraphical abstract for this article
       
  • A contact model for the deformation behaviour of pharmaceutical pellets
           under cyclic loading
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Dominik Weis, Fabian Krull, Julia Mathy, Maria Evers, Markus Thommes, Sergiy AntonyukSpherical pharmaceutical pellets are commonly produced by an extrusion-spheronization process. In the spheronizer, the wet cylindrical extrudates are rounded into spheres due to multiple collisions. In order to model this rounding, a suitable contact model, which can predict the dominantly plastic deformation behaviour, is necessary. In this study, a novel cyclic model for wet and dry pellets was developed. Various single particle compression and impact tests with pellets produced from microcrystalline cellulose (MCC) and lactose were conducted to calibrate and validate this model. It was found that the model is able to predict the energy dissipation as well as the deformation during pellet impact in the velocity range which is relevant for the spheronization process. Since the pellets are loaded multiple times during this process, the model was designed in order to account for the increasing flattening and hardening in the contact area as a function of the number of loading cycles. Therefore, the presented model allows the description of the pellet deformation by repeated stressing.Graphical abstractGraphical abstract for this article
       
  • Hydrothermal processing on potassic syenite powder: Zeolite synthesis and
           potassium release kinetics
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Changjiang Liu, Hongwen Ma, Yuan GaoTo make potassium accessible to agricultural application from K-silicates, processing on potassic syenite powder under mild alkaline hydrothermal conditions was conducted, as a result of which, potassium became accessible into solution, and to two zeolite powders (analcime and hydroxycancrinite) were successfully obtained. A scale-up operation in 25L-hydrothermal reactor supported the feasibility of further industrial implementation. The kinetic model derived from geochemical study was adopted to describe K+ release behavior, and two kinetic factors, reaction order and apparent activation energy, over temperature range of 477–531 K were 2.61 and 46.61 kJ/mol. The concentrated alkaline solution giving rise to higher reaction order and lower apparent activation energy was a dominated factor accelerating K-feldspar dissolution accomplished within hours. The hydrothermal approach proposed in this work is a simplified and green chemical way for the comprehensive utilization of K-silicates.Graphical abstractGraphical abstract for this article
       
  • Microstructure and properties of Cu-Cr-Nb alloy powder prepared by argon
           gas atomization
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Xueqian Lv, Zuming Liu, Ting Lei, Quan Li, Fan Zhao, Kai Peng, Yake Ren, Sizhe Lu, Bizhong NongThe Cu-2Cr-1Nb (at%) alloy powder was prepared by close-coupled argon gas atomization. The morphology, microstructure and phase were characterized by SEM, TEM, HRTEM, SAED and XRD. The effects of heat treatment on the microstructure and microhardness of the powder were investigated. The alloy matrix had equiaxed crystal structure, and the second phase was Cr2Nb intermetallic compound in sub-micron and nano-scale. Compared with large powder, the second phase of small powder is finer, and its distribution in the matrix is more uniform, the microhardness of the small powder is higher. After heat treatment at 773 K for 1 h, Cr and Nb precipitated and formed a large number of small precipitates, age hardening and peak aging phenomena occurred, and the peak hardness of the powder reached 130 HV. With the increase of heat treatment temperature, the second phase was coarsened. When the heat treatment temperature was 973 K, the short-time heat treatment hardening and long-time heat treatment softening were shown. However, after the heat treatment at 1223 K, only softening phenomenon was observed. This method can be used to prepare the excellent powder for Cu-Cr-Nb alloy, which can be used as a potential structural material for aerospace.Graphical abstractThe second phase in the alloy powder prepared by close coupled argon atomization was submicron and nanometer scale, and distributed in the copper matrix uniformly. The strengthening effect could be increased evidently.Graphical abstract for this article
       
  • Comprehensive numerical modelling of the hot isostatic pressing of
           Ti-6Al-4V powder: From filling to consolidation
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s): Alessandro Abena, Miren Aristizabal, Khamis EssaHot Isostatic Pressing (HIP) is a manufacturing process for production of near-net-shape components, where models based on Finite Element Method (FEM) are generally used for reducing the expensive experimental trials for canister design. Researches up to date implement in the simulation a uniform powder relative density distribution prior HIPping. However, it has been experimentally observed that the powder distribution is inhomogeneous after filling, leading to a non-uniform tool shrinkage. In this study a comprehensive numerical model for HIPping of Ti-6Al-4V powder is developed to improve model prediction by simulating powder filling and pre-consolidation by means of a two-dimensional Discrete Element Method (DEM). Particles’ dimension has been scaled up in order to reduce the computational cost of the analysis. An analytical model has been developed to calculate the relative density distribution from powder particle distribution provided by DEM, which is then passed in information to a three-dimensional FEM implementing the Abouaf and co-workers model for simulating powder densification during HIPping. Results obtained implementing the initial relative density distribution calculated from DEM are compared with those obtained considering a uniform relative density distribution over the powder domain (classic approach) at the beginning of the analysis. Experimental work has been carried out for validating the DEM (filling) and FEM (HIP) model. Comparison between experimental and numerical results shows the ability of the DEM model to represent the powder flow during filling and pre-consolidation, providing also a reliable values of the relative density distribution. It also highlights that taking into account the non-uniform powder distribution inside the canister prior HIP is vital to improve numerical results and produce near-net-shape components.Graphical abstractGraphical abstract for this article
       
  • Full title (Editorial Board Members)
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s):
       
  • Inside Front Cover (Aims & Scope, Editors)
    • Abstract: Publication date: November 2019Source: Advanced Powder Technology, Volume 30, Issue 11Author(s):
       
  • Dry powder formulation combining bedaquiline with pyrazinamide for latent
           and drug-resistant tuberculosis
    • Abstract: Publication date: Available online 4 September 2019Source: Advanced Powder TechnologyAuthor(s): Mohammad A.M. Momin, Bhamini Rangnekar, Ian Larson, Shubhra Sinha, Shyamal C. DasThe purpose of this study was to develop an inhalable combination dry powder formulation of bedaquiline and pyrazinamide and study their physicochemical properties and safety since this combination acts synergistically against Mycobacterium tuberculosis while pyrazinamide alone is active against latent TB and bedaquiline alone is active against drug-resistant TB. The cospray-dried powder of bedaquiline and pyrazinamide with 20% w/w of L-leucine consisted of spherical, porous particles of inhalable size with a diameter ≤3.2 µm. The aerosolization efficiency of the combination powder (FPF:>66%) evaluated using a next generation impactor was higher than bedaquiline-only (FPF: 31.3%) and pyrazinamide-only (FPF: 5.1%) powders, which could be due to the differences in the morphology of the powders. The combination powder was stable during storage for one month in a desiccator and 75% RH and also safe to both Calu-3 and A549 cells up to 100 µg/ml. This is the first report on the development of an inhalable combination dry powder formulation of bedaquiline and pyrazinamide with high aerosolization efficiency. This formulation has the potential to improve the treatment of both latent and drug-resistant TB.Graphical abstractGraphical abstract for this article
       
 
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