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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 426 journals)
Showing 1 - 200 of 265 Journals sorted alphabetically
AAS Open Research     Open Access  
ABC Journal of Advanced Research     Open Access  
Accountability in Research: Policies and Quality Assurance     Hybrid Journal   (Followers: 17)
Acta Materialia Transilvanica     Open Access  
Acta Nova     Open Access  
Acta Scientifica Malaysia     Open Access  
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Adıyaman University Journal of Science     Open Access  
Advanced Science     Open Access   (Followers: 12)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 3)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 2)
Advances in Research     Open Access  
Advances in Science and Technology     Full-text available via subscription   (Followers: 16)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 7)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access   (Followers: 4)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 2)
American Academic & Scholarly Research Journal     Open Access   (Followers: 4)
American Journal of Applied Sciences     Open Access   (Followers: 21)
American Journal of Humanities and Social Sciences     Open Access   (Followers: 10)
American Scientist     Full-text available via subscription   (Followers: 12)
ANALES de la Universidad Central del Ecuador     Open Access   (Followers: 1)
Anales del Instituto de la Patagonia     Open Access  
Applied Mathematics and Nonlinear Sciences     Open Access  
Apuntes de Ciencia & Sociedad     Open Access  
Arab Journal of Basic and Applied Sciences     Open Access  
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 1)
Archives Internationales d'Histoire des Sciences     Partially Free   (Followers: 5)
Archives of Current Research International     Open Access  
ARO. The Scientific Journal of Koya University     Open Access  
ARPHA Conference Abstracts     Open Access   (Followers: 1)
ARPHA Proceedings     Open Access  
ArtefaCToS : Revista de estudios sobre la ciencia y la tecnología     Open Access  
Asian Journal of Advanced Research and Reports     Open Access   (Followers: 1)
Asian Journal of Applied Science and Engineering     Open Access  
Asian Journal of Scientific Research     Open Access   (Followers: 2)
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 5)
Australian Field Ornithology     Full-text available via subscription   (Followers: 2)
Australian Journal of Social Issues     Hybrid Journal   (Followers: 7)
Avrasya Terim Dergisi     Open Access  
Bangladesh Journal of Scientific Research     Open Access  
Beni-Suef University Journal of Basic and Applied Sciences     Open Access  
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10)
Berkeley Scientific Journal     Full-text available via subscription  
BIBECHANA     Open Access  
BibNum     Open Access  
Bilge International Journal of Science and Technology Research     Open Access   (Followers: 1)
Bioethics Research Notes     Full-text available via subscription   (Followers: 16)
BJHS Themes     Open Access  
Black Sea Journal of Engineering and Science     Open Access  
Borneo Journal of Resource Science and Technology     Open Access  
Bulletin de la Société Royale des Sciences de Liège     Open Access  
Bulletin of the National Research Centre     Open Access  
Butlletí de la Institució Catalana d'Història Natural     Open Access  
Central European Journal of Clinical Research     Open Access  
Chain Reaction     Full-text available via subscription  
Ciencia Amazónica (Iquitos)     Open Access  
Ciencia en Desarrollo     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencia Ergo Sum     Open Access  
Ciência ET Praxis     Open Access  
Ciencia y Tecnología     Open Access  
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Citizen Science : Theory and Practice     Open Access   (Followers: 1)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Applied Sciences     Open Access  
Comunicata Scientiae     Open Access  
ConCiencia     Open Access  
Conference Papers in Science     Open Access  
Configurations     Full-text available via subscription   (Followers: 11)
COSMOS     Hybrid Journal   (Followers: 1)
Crea Ciencia Revista Científica     Open Access  
Cuadernos de Investigación UNED     Open Access  
Current Issues in Criminal Justice     Hybrid Journal   (Followers: 14)
Current Research in Geoscience     Open Access   (Followers: 6)
Dalat University Journal of Science     Open Access  
Data     Open Access   (Followers: 4)
Data Curation Profiles Directory     Open Access   (Followers: 4)
Dhaka University Journal of Science     Open Access  
Dharmakarya     Open Access  
Diálogos Interdisciplinares     Open Access  
Digithum     Open Access   (Followers: 2)
Discover Sustainability     Open Access   (Followers: 2)
Einstein (São Paulo)     Open Access  
Ekaia : EHUko Zientzia eta Teknologia aldizkaria     Open Access  
Elkawnie : Journal of Islamic Science and Technology     Open Access  
Emergent Scientist     Open Access  
Enhancing Learning in the Social Sciences     Open Access   (Followers: 6)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Entramado     Open Access  
Entre Ciencia e Ingeniería     Open Access  
Epiphany     Open Access   (Followers: 1)
Estação Científica (UNIFAP)     Open Access  
Ethiopian Journal of Education and Sciences     Open Access   (Followers: 5)
Ethiopian Journal of Science and Technology     Open Access  
Ethiopian Journal of Sciences and Sustainable Development     Open Access  
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 4)
European Scientific Journal     Open Access   (Followers: 2)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
Exchanges : the Warwick Research Journal     Open Access   (Followers: 1)
Experimental Results     Open Access  
Extensionismo, Innovación y Transferencia Tecnológica     Open Access  
Facets     Open Access  
Fides et Ratio : Revista de Difusión Cultural y Científica     Open Access  
Fırat University Turkish Journal of Science & Technology     Open Access  
Fontanus     Open Access  
Forensic Science Policy & Management: An International Journal     Hybrid Journal   (Followers: 239)
Frontiers for Young Minds     Open Access  
Frontiers in Climate     Open Access   (Followers: 3)
Frontiers in Science     Open Access   (Followers: 1)
Fundamental Research     Open Access   (Followers: 4)
Futures & Foresight Science     Hybrid Journal   (Followers: 2)
Gaudium Sciendi     Open Access  
Gazi University Journal of Science     Open Access  
Ghana Studies     Full-text available via subscription   (Followers: 14)
Global Journal of Pure and Applied Sciences     Full-text available via subscription  
Global Journal of Science Frontier Research     Open Access   (Followers: 1)
Globe, The     Full-text available via subscription   (Followers: 3)
HardwareX     Open Access  
Heidelberger Jahrbücher Online     Open Access  
Heliyon     Open Access  
Himalayan Journal of Science and Technology     Open Access  
History of Science and Technology     Open Access   (Followers: 1)
Hoosier Science Teacher     Open Access  
Impact     Open Access   (Followers: 1)
Indian Journal of History of Science     Hybrid Journal  
Indonesian Journal of Fundamental Sciences     Open Access  
Indonesian Journal of Science and Mathematics Education     Open Access   (Followers: 1)
Indonesian Journal of Science and Technology     Open Access  
Ingenieria y Ciencia     Open Access   (Followers: 1)
Innovare : Revista de ciencia y tecnología     Open Access  
Integrated Research Advances     Open Access  
Interciencia     Open Access  
Interface Focus     Full-text available via subscription  
International Annals of Science     Open Access  
International Archives of Science and Technology     Open Access  
International Journal of Academic Research in Business, Arts & Science     Open Access  
International Journal of Advanced Multidisciplinary Research and Review     Open Access  
International Journal of Applied Science     Open Access  
International Journal of Basic and Applied Sciences     Open Access   (Followers: 1)
International Journal of Computational and Experimental Science and Engineering (IJCESEN)     Open Access  
International Journal of Culture and Modernity     Open Access  
International Journal of Engineering, Science and Technology     Open Access  
International Journal of Engineering, Technology and Natural Sciences     Open Access  
International Journal of Innovation and Applied Studies     Open Access   (Followers: 3)
International Journal of Innovative Research and Scientific Studies     Open Access   (Followers: 1)
International Journal of Network Science     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access  
International Journal of Research in Science     Open Access   (Followers: 1)
International Journal of Science & Emerging Technologies     Open Access   (Followers: 1)
International Journal of Social Sciences and Management     Open Access   (Followers: 2)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 6)
International Letters of Social and Humanistic Sciences     Open Access  
International Scientific and Vocational Studies Journal     Open Access  
InterSciencePlace     Open Access  
Investiga : TEC     Open Access  
Investigación Joven     Open Access  
Investigacion y Ciencia     Open Access   (Followers: 1)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
iScience     Open Access   (Followers: 1)
Issues in Science & Technology     Free   (Followers: 7)
Ithaca : Viaggio nella Scienza     Open Access  
Jaunujų mokslininkų darbai     Open Access  
Journal de la Recherche Scientifique de l'Universite de Lome     Full-text available via subscription  
Journal of Chromatography & Separation Techniques     Open Access   (Followers: 10)
Journal of Advanced Research     Open Access   (Followers: 2)
Journal of Al-Qadisiyah for Pure Science     Open Access  
Journal of Alasmarya University     Open Access  
Journal of Analytical Science & Technology     Open Access   (Followers: 4)
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 1)
Journal of Big History     Open Access   (Followers: 3)
Journal of Composites Science     Open Access   (Followers: 3)
Journal of Deliberative Mechanisms in Science     Open Access  
Journal of Diversity Management     Open Access   (Followers: 4)
Journal of Indian Council of Philosophical Research     Hybrid Journal  
Journal of Institute of Science and Technology     Open Access  
Journal of Integrated Science and Technology     Open Access  
Journal of Kerbala University     Open Access  
Journal of King Saud University - Science     Open Access  
Journal of Mathematical and Fundamental Sciences     Open Access  
Journal of Natural Sciences and Mathematics Research     Open Access  
Journal of Natural Sciences Research     Open Access   (Followers: 1)
Journal of Negative and No Positive Results     Open Access  
Journal of Responsible Technology     Open Access  
Journal of Science (JSc)     Open Access  
Journal of Science and Engineering     Open Access  
Journal of Science and Technology     Open Access   (Followers: 2)
Journal of Science and Technology     Open Access   (Followers: 1)
Journal of Science and Technology (Ghana)     Open Access   (Followers: 3)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 1)
Journal of Science Foundation     Open Access   (Followers: 1)
Journal of Science of the University of Kelaniya Sri Lanka     Open Access  
Journal of Scientific Research     Open Access  
Journal of Scientific Research and Reports     Open Access  
Journal of Scientometric Research     Open Access   (Followers: 19)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Social Science Research     Open Access   (Followers: 2)
Journal of Taibah University for Science     Open Access  
Journal of the Asiatic Society of Bangladesh, Science     Open Access  

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Iranian Journal of Science and Technology, Transactions A : Science
Number of Followers: 0  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1028-6276 - ISSN (Online) 2364-1819
Published by Springer-Verlag Homepage  [2469 journals]
  • U-Model-Based Dynamic Inversion Control for a Class of Nonlinear Dynamical
           Systems

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      Abstract: Different types of techniques such as state-space linearization method and state-dependent parameter method are available for designing a control system of nonlinear plant although a little bit disadvantages generally occur. This paper deals with the adaptive controller which is based on recently developed U-Model-based control that has contributed a generic approach for modeling and controlling of various complicated systems. U-Model works with less number of parameters and variables, resulting a simple model configuration and applied to both linear and nonlinear dynamical systems. The single inverted pendulum on a cart being an unstable, nonlinear system is popularly applied as a benchmark for designing different control methodologies. Here, the control objective of this proposed work is to control the system in such a way that when the cart reaches the desired position, this inverted pendulum is balanced in an upright position with a particular angle, for achieving the aforementioned goal this paper has proposed U-Model dynamic inversion control, U-Model-based Model Reference Adaptive Control technique with Massachusetts Institute of Technology rule, Feedback linearization-based dynamic inversion technique and different Model Reference Adaptive Control methodologies. The novel contribution of the proposed work is to implement U-Model-based dynamic inversion technique where the inversion of the closed loop is performed for the development of the invariant controller, and ultimately, the necessity of solving complex diophantine equation is avoided. The MATLAB Simulink environment is applied for simulation of the proposed technique for determining the system performance.
      PubDate: 2022-01-25
       
  • Thermal, Structural Properties and Potential Dynamic Corrosion Study of
           Ti-27Ni-21Nb-2Ta SMA

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      Abstract: In this study, Ti-27Ni-21Nb-2Ta (at. %) alloy was produced by arc-melting method. The physical and chemical properties of the alloys such as phase transformation temperatures, thermal activation energies, microstructure, electrochemical resistance, microhardness were investigated. Phase transformation temperatures were determined by DSC. The thermal activation energies of the alloy were calculated according to the Ozawa, Kissenger, and Takhor methods. The average thermal activation energy obtained according to these calculations was 56.35 kJ/mol. The optical microscope (OM) and SEM images showed that the alloy consisted of a dendritic structure. \(\beta\) -Nb, B2, and B19/ peaks were found in the XRD pattern. Additionally, the crystallite size calculated by the Scherrer equation was estimated to be approximately 29.86 nm. Electrochemical investigation performed in SBF (artificial body fluid) at room temperature (RT) yielded a corrosion resistance rate of 9.38 × 10–6 mmpy analysis. The microhardness measurement of the alloys was taken from five distinct regions with an average of 376 HV0.3.
      PubDate: 2022-01-21
       
  • Platinum Coatings on SS304: Photocatalytic Dye Degradation Application

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      Abstract: This article successfully explains the coating of platinum on stainless steel sample (SS304) by simple direct current electrodeposition (DC) and pulse current electrodeposition (PC) method. All parameters of operation like current density temperature, duty cycle and pH were optimized. Various analysis techniques were used to categorize the platinum deposited sample, including electron dispersive spectroscopy, scanning electron microscopy and atomic force microscopy. Platinum-coated samples show excellent photocatalytic activity towards methylene blue. PC-coated sample shows better dye degradation performance than DC-coated sample which was monitored by using UV–Vis spectrophotometer.
      PubDate: 2022-01-21
       
  • Kinetic and Equilibrium Studies of Cr(VI) Adsorption Using
           Glutaraldehyde-Crosslinked Chitosan Beads

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      Abstract: The increase of pollution in aquifers by heavy metals in Mexico, because of industrialization and urbanization, have had negative effects for the environment and public health. This work aimed to evaluate the kinetic and equilibrium studies of Cr(VI) adsorption using glutaraldehyde-crosslinked chitosan beads in aqueous systems. Glutaraldehyde-crosslinked chitosan beads were prepared, and three different masses (3, 6, 9 g) were evaluated with 5 concentrations of Cr (VI) (20, 30, 50, 80, 100 mg/L). The adsorption mechanisms were studied through the adsorption isotherms of Langmuir and Freundlich, as well as the adsorption kinetics of pseudo-first order, pseudo-second order, and Elovich based on experimental data. Results showed that after 10 min. of exposure, the beads adsorbed more than 50% of the initial concentration of Cr(VI), and after 90 min. it was possible to remove up to 100% of Cr(VI) contained in the water. The adsorption kinetics of pseudo-second order and Elovich showed the best fits compared to pseudo-first order. Based on these results, glutaraldehyde-crosslinked chitosan beads could be proposed as a good alternative for the removal Cr(VI) from aqueous systems.
      PubDate: 2022-01-21
       
  • Estimation and Optimization for Step-Stress Accelerated Degradation Tests
           Under an Inverse Gaussian Process with Tampered Degradation Model

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      Abstract: This paper addresses the estimation and optimization problems for a step-stress accelerated degradation test (SSADT) when a product’s degradation follows an inverse Gaussian (IG) process. Developing a link model to connect the deterioration measurements at different stress levels is a primary concern for this design issue. In this paper, we propose a tampered degradation model and construct a new framework to model the effect of changing stress from a level to another on the degradation path. Parameter estimates are obtained by both maximum likelihood and Bayesian methods. Under the constraint that the total experimental cost does not exceed a pre-specified budget, the optimal settings such as sample size, measurement frequency, and the number of measurements at each stress level are obtained. Finally, a real-world example is analyzed to illustrate the application of the proposed method. A notable finding was that enlarging the difference between the two stress levels makes the test more efficient.
      PubDate: 2022-01-21
       
  • Generalized Diffusion Characteristics of Calcium Model with Concentration
           and Memory of Cells: A Spatiotemporal Approach

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      Abstract: The anomalous diffusion gives a more concise description of the biophysical process. One of the indispensable processes in the nervous system is the diffusion of free calcium ( \(\hbox {Ca}^{2+}\) ) in nerve cells. An alteration/dysfunction of \(\hbox {Ca}^{2+}\) leads to cell death and consequently manifests the early symptoms of many neurological disorders. In the context of this, we have presented a two-dimensional fractional-order reaction–diffusion model to develop a control mechanism of \(\hbox {Ca}^{2+}\) dynamics. We have used the integral transform technique of arbitrary order to find the solution of the proposed \(\hbox {Ca}^{2+}\) diffusion model. Due to the lack of smoothness of the solution, we have presented different schemes to obtain the closed-form solution. Finally, we have simulated the results in MATLAB software to show the diffusion characteristics on the \(\hbox {Ca}^{2+}\) model and exhibit the control strategy to optimize calcium concentration. Furthermore, the obtained results are interpreted with the physiology of Parkinson’s. We observed that when space derivative moved from integer to fractional-order and the time derivative moved from fractional to integer-order we get an optimum control on \(\hbox {Ca}^{2+}\) diffusion due to the intermediate memory and generalized diffusion characteristics of cells. Thus, we conclude that the generalized diffusion characteristics and memory of cells are enhanced the control strategy on the \(\hbox {Ca}^{2+}\) diffusion model.
      PubDate: 2022-01-21
       
  • Steady-State and Transient Raman Gain Coefficients of Semiconductor
           Magneto-plasmas (Calculated for n-InSb-CO2 Laser System)

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      Abstract: Assuming that the origin of stimulated Raman scattering (SRS) lies in third-order effective (Raman) susceptibility arising due to nonlinear induced polarization, we obtained expressions for steady-state and transient Raman gain coefficients of weakly polar semiconductors magneto-plasmas under various geometrical configurations. The threshold pump intensity and optimum pulse duration for the onset of transient SRS have been estimated. For numerical calculations, we consider n-InSb crystal at 77 K temperature as a Raman active medium irradiated by a pulsed CO2 laser. The dependence of Raman gain coefficients on doping concentration, external magnetostatic field and its inclination, scattering angle and pump pulse duration have been explored in detail with aim to determine suitable values of these controllable parameters to enhance Raman gain coefficients at lower threshold intensities, and to search the feasibility of efficient semiconductor nonlinear devices based on Raman nonlinearities. Most expectedly, the technological potentiality of weakly polar semiconductor magneto-plasmas as hosts for compression of scattered pulses and fabrication of efficient nonlinear devices such as frequency converters, Raman amplifiers and oscillators based on Raman nonlinearities have been established.
      PubDate: 2022-01-13
       
  • Blind Signature Protocol Based on Hidden Discrete Logarithm Problem Set in
           a Commutative Algebra

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      Abstract: A new blind signature scheme is proposed which is characterized in that it is based on a hidden discrete logarithm problem defined in a finite commutative associative algebra. The used algebraic support represents a 4-dimensional commutative associative algebra defined over the ground finite field GF(p), commutative group of which possesses 4-dimensional cyclicity. The public key represents a triple of vectors contained in different cyclic subgroup of the multiplicative group. Correspondingly, three different blinding factors are used to insure the anonymity property of the introduced blind signature protocol.
      PubDate: 2022-01-04
       
  • Modify RF Cavity of 10 MeV Cyclotron to Improve the Beam Gain by Beam
           Dynamic Analysis

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      Abstract: In this study, the central region and beam dynamic of a 10 MeV H− AVF cyclotron called IranCYC10 have been considered. The aim of this cyclotron is to accelerate H− ions up to 10 MeV energy and extract H+ ions to produce PET radioisotopes for medical applications. The cyclotron that is currently in fabrication consists of four sector magnets and two RF cavity parts which operate in 71 MHz frequency. The internal cold-cathode Penning Ion Gauge ion source that was used in this cyclotron, caused the central region design to become very sensitive and complex. In the first step, in order to obtain the optimized beam efficiency at the central region, the beam injection conditions, design of magnet center poles and adjustment of the pullers position have been determined. In contrast to conventional methods which design desired structure of central region based on trial and error, this design is carried out due to consideration of equilibrium orbit. In addition to the beam dynamic analysis in the early turns such as usual works, it is calculated until the extraction of the beam, as the second step. Our new developed code named BDIC (Beam Dynamic of Iran Cyclotron) has been developed for the calculation of the central region and beam dynamics of the cyclotron based on proposed algorithm. This code has been written in C++ program that uses the conventional Runge–Kutta method. The input data of this code including the electric and magnetic field distribution have been designed by OPERA-3D/TOSCA. In order to verify the BDIC code, optimized results of the code have been compared with the results of well-known beam dynamic programs, CYCLONE.
      PubDate: 2021-12-23
       
  • Response of Lettuce to Silver Nanoparticles Under Drought Conditions

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      Abstract: Nano-fertilization is an emerging technology to improve agricultural productivity under diverse ecosystems. Our study was conducted to investigate the effects of foliar fertilization of silver nanoparticles (AgNPs) on the growth, enzyme activities and water use efficiency (WUE) of lettuce (Lactuca sativa, L.) under drought conditions. A pot culture study with 4 AgNPs rates × 2 stress levels in a factorial combination of randomized complete block (RCB) design was conducted. The AgNPs levels were 0 (control), 25, 50, 75 and 100 mg/L) were imposed on lettuce seedlings under ambient and simulated drought (~50% field moisture capacity of soil) conditions. Lettuce plant height, total yields, leaf relative water content (RWC), chlorophyll content, membrane injury (MII), glutathione S-transferase (GST), glutathione reductase (GR), carboxylesterase (CaE), total phenolics and flavonoids and WUE were determined and/or calculated. The results showed that GST activity reduced in treatments of AgNPs + stress compared to stressed plants. In treatment of 100 mg L−1 AgNPs + stress, GR activity increased in treatments of 25, 50 and 75 mg L−1 AgNPs, but showed a significant decrease in 100 mg L−1 AgNPs + stress. CaE activity enhanced in 100 mg L−1 AgNPs + stress (about 1.55-fold) compared to stressed plants. Total flavonoid and phenolic contents were the highest in 50 mg L−1 AgNPs + stress. It was not obtained significant effects in the WUE rates. In 100 mg L−1 AgNPs, MII rates were the highest, and RWC rates were the lowest. Leaf width, plant height and total yield decreased at doses of AgNPs.
      PubDate: 2021-12-02
       
  • Correction to: On the Signed Complete Graphs with Maximum Index

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      PubDate: 2021-12-01
       
  • Oil Sorbent Based on Luffa Fiber-Graft-Poly(Butyl Acrylate) Copolymer

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      Abstract: Luffa cylindrica is primarily used as a vegetable, but its dry fiber can be also used as a sponge. L. cylindrica has a ligneous fibrous netting system, in which the fibrous cords are disposed in a multidirectional array, forming a natural mat. In this work, we aim to synthesize a potential material for oil spill cleanup by the graft polymerization of butyl acrylate (BA) onto Luffa fiber (LF) using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The grafting process has been controlled by monomer and AIBN concentrations, reaction time and temperature, in which the optimal condition for the highest graft yield of 40.60% is [AIBN] = 0.035 mol/L, [BA] = 1.50 mol/L, 180 min at 75 °C. The graft copolymer LF-g-BA is structurally characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. In the presence of crosslinking agent divinyl benzene, the oil sorption capacity of the synthetic LF-g-BA reaches 20.60 g oil/g sorbent for 48-h treatment. The LF-g-BA material can be seen as a potential sorbent due to its swelling property in non/weak polar mediums and reusable feature.
      PubDate: 2021-12-01
       
  • Extraction of Oleic Acid from Animals Oil and Its Anti-inflammatory Effect
           on Network Pharmacology

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      Abstract: The purpose of this paper is to explore the possible mechanisms of anti-inflammatory and scar repair by Mongolian horse oil. We used TCM database and literature mining to collect active compounds of horse oil and used Swiss TargetPrediction and SuperPred server to find targets of compounds. Anti-inflammatory drug targets were collected through the CTD database. Go annotation of targets and KEGG pathway were enriched and analyzed through Metascape database platform. Molecular docking between active ingredients and targets was verified by AutoDock software. Metascape analysis revealed that the key candidate targets were significantly enriched in a number of pathways associated with inflammatory pathology. The results of molecular docking showed that oleic acid, a major component of animals oil, could influence the regulatory functions of TNF, NGF, IL6, IL1B, Jun, and CDK1. This suggests that animals oil can regulate the development of inflammation through its active ingredient, oleic acid, and can influence the expression of multiple signaling pathways, with theoretical endogenous interactions with TNF, NGF, IL6, IL1B, JUN, and CDK1 proteins.
      PubDate: 2021-12-01
       
  • Dopamine D2 Receptor Antagonist Alters the Testosterone Release and
           Kisspeptin/GPR54 Signaling in Food-Restricted Rats

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      Abstract: It is well established that acute food restriction (FR) has a suppressive effect on the reproductive system that may be mediated through attenuating the kisspeptin/GPR54 signaling in the hypothalamus. Kisspeptin neurons have been shown to express the dopamine D2 receptor (D2R). The aim of the present study was to investigate the effect of chronic food restriction and/or antagonism of D2R by sulpiride on testosterone release and kisspeptin/GPR54 signaling in male rats. Sixty-six male Wistar rats, weighing-200 ± 20 g, were divided into seven groups including control, sham, 25%FR, 50%FR, 75%FR, sulpiride (50 µg/rat i.c.v., once at the end of treatment), 75%FR + sulpiride. FR was applied for 21 days. At the end, the mean serum testosterone level and the hypothalamic mRNAs expression of KiSS1, GPR54, D2R, and dopamine concentration were evaluated. The results demonstrated that the testosterone level significantly decreased in 50% and 75% food-restricted animals, and in sulpiride group, compared to control rats (P < 0.05). Injection of sulpiride to 75% food-restricted animals reduced the testosterone levels compared to all other groups (P < 0.05). Also, chronic 75%-FR significantly increased kisspeptin mRNA, dopamine concentration, but decreased D2R-mRNA (P < 0.05), and non-significantly decreased the GPR54mRNA (P > 0.05) compared to the control. Sulpiride injection to 75% food-restricted animals significantly decreased kisspeptin mRNA and increased dopamine concentration (P < 0.05), but had no significant effect on GPR54 or D2R-mRNAs expression, compared to 75% food-restricted group. In conclusion, we suggest that chronic food restriction decreases the testosterone release and then increases the kisspeptin/GPR54 signaling, and that the involvement of dopamine D2 receptor in these effects.
      PubDate: 2021-12-01
       
  • Poisson Noise Removal Using Non-convex Total Generalized Variation

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      Abstract: As is well-known that the total generalized variation model performs well in reducing the staircasing effect while removing noise, but it tends to cause the undesirable edge details blurring. To overcome this drawback, the current paper introduces the non-convex restriction into the total generalized variation regularizer and constructs an improved edge-preserving optimization model for Poissonian images restoration. For solving the minimization problem, we propose an efficient alternating minimization method by skillfully combining the classical iteratively reweighted \(\ell _1\) algorithm and primal-dual framework. Some visual experiments presented in the illustration section, which are compared with some related denoising methods, demonstrate the better performance of the developed scheme in staircase artifacts reduction and image features protection. Besides, the measurable comparisons also indicate that our outcomes enjoy the best restoration accuracy against other popular competitors.
      PubDate: 2021-12-01
       
  • Assessment of Phenolic Contents and Antibacterial, Cytotoxic, and
           Antioxidant Activities of Five Brown Algae from the Persian Gulf

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      Abstract: Marine sources have attracted worldwide attention due to their various biological activities. This study reports the cytotoxic, antioxidant, and antibacterial activities and phenolic contents of solvent extracts sequentially prepared by 80% methanol (MeOH), MeOH, and dichloromethane (DCM), of five brown algae from the Persian Gulf: Colpomenia sinuosa (C. sinuosa), Sargassum acinaciforme (S. acinaciforme), Iyengaria stellata (I. stellata), Sirophysalis trinodis (S. trinodis), and Padina gymnospora (P. gymnospora). The cytotoxicity of the extracts was determined against human acute lymphoblastic leukemia (MOLT-4) cells. We have determined the DCM extracts of C. sinuosa and S. acinaciforme and I. stellata as the most potent cytotoxic agents with IC50 values of 23.95 ± 1.9, 31.6 ± 8.5, and 36.0 ± 6.0 µg/mL, respectively. Additionally, the extracts were subjected to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and Folin-Ciocalteu total phenolic assays. The MeOH extract of P. gymnospora showed the highest antioxidant activity with the highest radical scavenging potential (IC50 = 746.76 ± 94.15 µg/ml DPPH), which was consistent with its highest phenolic content (70.24 ± 5.40 mg equivalent to gallic acid in 1 g algal extract: mg EG/g AE). Finally, the antibacterial activity of the extracts was assessed against three Gram-positive and four Gram-negative bacteria using the broth dilution method by determination of the minimum inhibitory concentrations (MICs). The MeOH and 80% MeOH extracts of P. gymnospora and C. sinuosa exhibited the strongest antibacterial activity against all tested microorganisms, with the MIC values ranging from 0.62 to 5.00 mg/mL. In conclusion, the DCM extracts of the algae are suggested as the best sources of cytotoxic metabolites, while the MeOH and 80% algal extracts were week antioxidants (IC50s 746.76–5000 µg/ml DPPH) and contained lower amounts of phenolics (1.61–70.24 mg EG/g AE), but they are better source (0.62 to 5.00 mg/mL) of antibacterial metabolites.
      PubDate: 2021-12-01
       
  • Interactions Between Ecological Factors in the Development and Survival of
           Bufotes variabilis: Resilience to Change

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      Abstract: Invasive species and climate change are important factors in amphibian declines. Climate change mediates impacts on water level fluctuations and amphibian densities. In this study, the interaction effects of invasive species (Gambusia holbrooki), desiccation, and high density were investigated on growth, size, time and percentage of metamorphosis, and survival Bufotes variabilis larvae within 60 d. We designed a 2 × 2 × 3 factorial experiment, crossing two levels of predatory cues (presence/absence), two levels of tadpole density (low/ high) and three levels of water (low/high/ decreasing). Results of the experiment showed mean larval growth rate was highest for both of presence of predator × high water level × high density and presence of predator × decreasing water level × low density treatments (0.30 mm/day). The slowest development time, the lowest percentage of metamorphosis and survival rate were observed at the presence of predator × high water level × high density treatment. Except for the significant impact of the presence of predator and density of tadpoles on survival, independent and interactive effects of three factors showed not significant effects on growth and survival. According to the results of the experiments, although each of the factors of predatory cues, density and water level influence the larval period, size and percentage of metamorphosis separately, however, their interactive effect is not significant. For effective conservation management, this study suggests that more research is needed on different species of amphibians.
      PubDate: 2021-12-01
       
  • Effects of Aging on Magnetic and Thermal Characteristics of NiMnCoSn
           Magnetic Shape Memory Alloys

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      Abstract: Heusler shape memory alloys are important for many applications due to their typical magnetic and shape memory behaviors. In this study, a Ni50Mn36Sn12Co2 (at.%) alloy was manufactured by arc-melting technique, then the ingot cooled to ambient temperature in the natural atmosphere. Three different temperatures, including 500 °C (773 K), 700 °C (973 K), and 900 °C (1173 K), was selected for aging the samples cut from the main ingot. The impact of aging on the crystalline; microstructure; caloric; and magnetic properties of the alloys were investigated through x-ray diffraction (XRD); scanning electron microscope; differential scanning calorimetric (DSC), differential thermal analysis, and thermal gravimetric (TG); and physical property measuring system was investigated, respectively. The aging in different temperatures led to the shift DSC curve, such that the martensitic phase transformation temperatures of the sample aged at 773 K increased, however, the transformation at 973 and 1173 K decreased compared to the as-casted alloy. The different phase transformation behavior showed that the alloy aged at 773 K has the maximum elastic energy, enthalpy and entropy change compared to the reset of samples, on the other hand, its crystallite sized obtained from XRD analysis comparably diminished. Besides, the TG analysis revealed that the mass gain almost occurs at a temperature above 773 K, therefore the magnetization of the alloys aged at 973 and 1173 K decreased due to a thin oxide layer formed on the surface of the alloys.
      PubDate: 2021-12-01
       
  • Magnetic Dispersive Solid Phase Extraction of Cu (II) as 1-
           (2-pyridylazo)-2-naphthol Chelates on Fe3O4@XAD-16

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      Abstract: Fe3O4@XAD-16 has been used as adsorbent for magnetic dispersive solid phase extraction of Cu(II) as with 1- (2-pyridylazo) -2-naphthol (PAN) complex prior to flame atomic absorption spectrometric detection of copper. The effects of important parameters affecting extraction efficiency such as pH, adsorbent amount, eluent concentration and volume, model solution volume and ultrasonic bath time on magnetic solid phase extraction were studied in detail. The optimum pH for the extraction of Cu (II) was 6.0. The enrichment factor was 25. The accuracy of the extraction method was determined by the analysis of HR-1 (river sediment) and TMDA-53.3 (lake water) certified reference materials. The method was applied to determination of copper contents of food and water samples.
      PubDate: 2021-12-01
       
  • Evaluation of the Natural Radioactivity of Samples of Some Types of Field
           Crops in Different Areas of Tikrit, Iraq

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      Abstract: This study aims to assess the concentrations of natural radionuclides activity (226Ra,232Th and 40 K) and calculate a number of radiation risk indicators in some types of field crops in different areas of Tikrit City-Salah Al-Din Governorate-Iraq. The measurement was carried out using a gamma-ray spectroscopy connected with a scintillation detector crystallized with thallium-activated sodium iodide NaI(TI). The results were that the mean concentrations of elements (226Ra, 232Th and 40 K) were (6.79 \(\pm 0.331\, Bq/kg,10.79 \pm 0.640\, Bq/kg, 133.34 \pm 5.895\, Bq/kg\) ), respectively. And, the radiation risk indicators were less than the international permissible and the recommended average, so that the samples under study are safe and suitable for human and animal consumption.
      PubDate: 2021-10-03
      DOI: 10.1007/s40995-021-01222-0
       
 
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