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Seed Mediated Growth of Gold Nanoparticles Based on Liquid Arc Discharge

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Plasma Science and Technology 2013年第4期15卷 376-381页

作者： Ali akbar ASHKARRAN Department of Physics Faculty of Basic Sciences University of MazandaranBabolsar Iran

We report studies on the growth of gold nanoparticles by a seed-mediated approach in solution. The synthetic method is adapted from one we published earlier （Ashkarran et al. Appl. Phys. A 2009, 96, 423）. The synthesized gold nanoparticles were characterized by X-ray diffraction （XRD）, dynamic light scattering （DLS）, UV-Vis spectroscopy, optical imaging and atomic force microscopy （AFM）. Optical absorption spectroscopy of the prepared samples at 15 A arc current in HAuCI4 solution shows a surface plasmon resonance around 520 nm. It is found that sodium citrate acts as a stabilizer and surface capping agent of the colloidal nanoparticles. The intensity of the plasmonic peak of the prepared gold nanoparticles for 1 minute arc duration gradually increases due to seed mediation for up to 6 hours. The formation time of gold nanoparticles at higher seed concentrations is less than that at lower seed concentrations.

关键词： gold nanoparticles liquid arc discharge seed mediation optical properties

Zataria multiflora and its constituent,carvacrol,counteract sepsis-induced aortic and cardiac toxicity in rat:Involvement of nitric oxide and oxidative stress

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Animal Models and Experimental Medicine 2023年第3期6卷 221-229页

作者： Mahmoud Hosseini Zohreh Arab Farimah Beheshti akbar Anaeigoudari Farzaneh Shakeri Arezoo Rajabian Psychiatry and Behavioral Sciences Research Center Mashhad University of Medical SciencesMashhadIran Applied Biomedical Research Center Mashhad University of Medical SciencesMashhadIran Neuroscience Research Center Torbat Heydariyeh University of Medical SciencesTorbat HeydariyehIran Department of Physiology School of Paramedical SciencesTorbat Heydariyeh University of Medical SciencesTorbat HeydariyehIran Department of Physiology School of MedicineJiroft University of Medical SciencesJiroftIran Natural Products and Medicinal Plants Research Center North Khorasan University of Medical SciencesBojnurdIran Department of Physiology and Pharmacology School of MedicineNorth Khorasan University of Medical SciencesBojnurdIran Department of Internal Medicine Faculty of MedicineMashhad University of Medical SciencesMashhadIran

Background:Zataria multiflora and carvacrol showed various pharmacological prop-erties including anti-inflammatory and anti-oxidant ***,up to now no studies have explored its potential benefits in ameliorating sepsis-induced aortic and cardiac ***,this study aimed to investigate the effects of *** and carvacrol on nitric oxide(NO)and oxidative stress indicators in lipopolysaccharide(LPS)-induced aortic and cardiac ***:Adult male Wistar rats were assigned to:Control,lipopolysaccharide(LPS)(1 mg/kg,intraperitoneal(i.p.)),and *** hydro-ethanolic extract(ZME,50–200 mg/kg,oral)-and carvacrol(25–100 mg/kg,oral)-treated *** was in-jected daily for 14 *** with ZME and carvacrol started 3 days before LPS administration and treatment continued during LPS *** the end of the study,the levels of malondialdehyde(MDA),NO,thiols,and antioxidant enzymes were ***:Our findings showed a significant reduction in the levels of superoxide dis-mutase(SOD),catalase(CAT),and thiols in the LPS group,which were restored by ZME and ***,ZME and carvacrol decreased MDA and NO in car-diac and aortic tissues of LPS-injected ***:The results suggest protective effects of ZME and carvacrol on LPS-induced cardiovascular injury via improved redox hemostasis and attenuated NO ***,additional studies are needed to elucidate the effects of ZME and its constituents on inflammatory responses mediated by LPS.

关键词： carvacrol lipopolysaccharide nitric oxide oxidative injury sepsis Z.multiflora

Thermodynamic Interpretation of Field Equations at Horizon of BTZ Black Hole

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Chinese Physics Letters 2007年第5期24卷 1158-1161页

作者： M. akbar Institute of Theoretical Physics Chinese Academy of Sciences PO Box 2735 Beijing 100080

A spacetime horizon comprising with a black hole singularity acts like a boundary of a thermal system associated with the notions of temperature and entropy. In the case of static metric of Banados-Teitelboim-Zanelli （BTZ） black hole, the field equations near the horizon boundary can be expressed as a thermal identity dE = TdS＋ Pr dA, where E = M is the mass of BTZ black hole, dA is the change in the area of the black hole horizon when the horizon is displaced infinitesimally small, Pr is the radial pressure provided by the source of Einstein equations, S = 41πa is the entropy and T =κ/2π is the Hawking temperature associated with the horizon. This approach is studied further to generalize it for non-static BTZ black hole, showing that it is also possible to interpret the field equation near horizon as a thermodynamic identity dE = TdS ＋ PrdA ＋Ω＋dJ, where Ω＋ is the angular velocity and J is the angular momentum of BTZ black hole. These results indicate that the field equations for BTZ black hole possess intrinsic thermodynamic properties near the horizon.

关键词： SITTER SPACETIMES 1ST LAW GRAVITY ENTROPY

Viscous Cosmology and Thermodynamics of Apparent Horizon

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Chinese Physics Letters 2008年第12期25卷 4199-4202页

作者： M. akbar Centre for Advanced Mathematics and Physics National University of Sciences and Technology Peshawar Road Rawalpindi Pakistan

It is shown that the differential form of Friedmann equations of Friedman-Robertson-Walker （FRW） universe can be recast as a similar form of the first law ThdSh = dE＋ WdV of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid. It is also shown that by employing the general expression of temperature Th=｜k｜/2π=1/2π~rA（1-2~rA/2H^rA）associated with the apparent horizon of an FRW universe and assumed that the temperature Tm of the energy inside the apparent horizon is proportional to the horizon temperature Tm=bTh, we are able to show that the generalized second law of thermodynamics holds in the Einstein gravity provided Th-Tm/~rA≤（ρ＋~P）.

关键词： field emission molybdenum dioxide enhancement factor

Short-term prediction of NO_(2) and NO_(x) concentrations using multilayer perceptron neural network: a case study of Tabriz, Iran

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Ecological Processes 2017年第1期6卷 21-29页

作者： akbar Rahimi Department of Landscape Engineering Agricultural FacultyUniversity of TabrizBolvare 29 BahmanTabrizIran

Introduction:Due to the health effects caused by airborne pollutants in urban areas,forecasting of air quality parameters is one of the most important topics of air quality *** recent years,statistical models based on artificial neural networks(ANNs)have been increasingly applied and evaluated for forecasting of air ***:The development of ANN and multiple linear regressions(MLRs)has been applied to short-term prediction of the NO_(2) and NO_(x) concentrations as a function of meteorological *** optimum structure of ANN was determined by a trial and error *** used hourly NO_(x) and NO_(2) concentrations and metrological parameters,automatic monitoring network during October and November 2012 for two monitoring sites(Abrasan and Farmandari sites)in Tabriz,***:Designing of the network architecture is based on the approximation theory of Kolmogorov,and the structure of ANN with 30 neurons had the best *** trained by scaled-conjugate-gradient(trainscg)training algorithm has implemented to *** also demonstrates that MLP neural networks offer several advantages over linear MLR *** results show that the correlation coefficient(R2)values are 0.92 and 0/94 for NO_(2) and NO_(x) concentrations,*** in MLR model,R2 values were 0.41 and 0.44 for NO_(2) and NO_(x) concentrations,***:This work shows that MLP neural networks can accurately model the relationship between local meteorological data and NO_(2) and NO_(x) concentrations in an urban environment compared to linear models.

关键词： Air pollution prediction Artificial neural network Multilayer perceptron NO_(2) NO_(x)

Correlation between process parameters,grain size and hardness of friction-stir-welded Cu-Zn alloys

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Rare Metals 2018年第5期37卷 388-398页

作者： akbar Heidarzadeh Tohid Saeid Faculty of Materials Engineering Sahand University of Technology

In this study, the effects of tool rotational speed, tool traverse speed, and Zn content on the grain size and hardness of the friction-stir-welded （FSWed） Cu-Zn alloy joints were investigated. The microstructures of the joints were examined using optical microscope （OM） and scanning transmission electron microscope （STEM）. Vickers hardness test was conducted to evaluate the hardness of the joints. In addition, the relationships between the process parameters, grain size, and hardness of the joints were established. The results show that the developed relationships predict the grain size and hardness of the joints accurately. The Zn content of the alloys is the most effective parameter on the grain size and hardness, where the tool traverse speed has the minimum effect. The relationship between the hardness and grain size of the joints has a deviation from the Hall-Petch equation due to formation of high dislocation density inside the grains. At higher Zn amounts, the dislocation tangles with high density form instead of dislocation cells, and hence, lower conformity with the Hall-Petch relationship is observed.

关键词： Friction stir welding Grain size Hardness Cu-Zn alloy

Synthesis of clay-supported nanoscale zero-valent iron using green tea extract for the removal of phosphorus from aqueous solutions

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Chinese Journal of Chemical Engineering 2017年第7期25卷 924-930页

作者： akbar Soliemanzadeh Majid Fekri Department of Soil Sdence College of AgricultureShahid Bahonar University of KermanKermanlran

This study addresses the synthesis of nanoscale zero-valent iron(n ZVI) in the presence of natural bentonite(B-n ZVI) using green tea extract. The natural bentonite and B-n ZVI were then applied for the removal of phosphorus from aqueous solutions at various concentrations, p H levels and contact time. The desorption of phosphorus(P) from adsorbents was done immediately after sorption at the maximum initial concentration using the successive dilution method. The characterization of FTIR, SEM, and XRD indicated that n ZVI was successfully loaded to the surface of natural bentonite. The sorption of phosphorus on B-n ZVI was observed to be p H-dependent, with maximum phosphorus removal occurring at the p H range of 2 to 5. The results demonstrate that the maximum sorption capacities of natural bentonite and B-n ZVI were 4.61 and 27.63 mg·g^(-1), ***, Freundlich, and Redlich–Peterson models properly described the sorption isotherm data. For either adsorbent, desorption isotherms did not coincide with their corresponding sorption isotherms, suggesting the occurrence of irreversibility and hysteresis. The average percentages of retained phosphorus released from natural bentonite and B-n ZVI were 80% and 9%, respectively. The results indicated that sorption kinetics was best described by the pseudo-second-order model. The present study suggests that B-n ZVI could be used as a suitable adsorbent for the removal of phosphorus from aqueous solutions.

关键词：绿茶提取物零价铁水溶液除磷纳米合成天然膨润土吸附等温线

Multiobjective optimization scheme for industrial synthesis gas sweetening plant in GTL process

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Journal of Natural Gas Chemistry 2011年第1期20卷 99-109页

作者： Alireza Behroozsarand akbar Zamaniyan Department of Chemical Engineering Islamic Azad University Department of Natural Gas Conversion Gas Research Division Research Institute of Petroleum Industry (RIPI)

In industrial amine plants the optimized operating conditions are obtained from the conclusion of occurred events and challenges that are normal in the working units. For the sake of reducing the costs, time consuming, and preventing unsuitable accidents, the optimization could be performed by a computer program. In this paper, simulation and parameter analysis of amine plant is performed at first. The optimization of this unit is studied using Non-Dominated Sorting Genetic Algorithm-II in order to produce sweet gas with CO 2 mole percentage less than 2.0% and H 2 S concentration less than 10 ppm for application in Fischer-Tropsch synthesis. The simulation of the plant in HYSYS v.3.1 software has been linked with MATLAB code for real-parameter NSGA-II to simulate and optimize the amine process. Three scenarios are selected to cover the effect of （DEA/MDEA） mass composition percent ratio at amine solution on objective functions. Results show that sour gas temperature and pressure of 33.98 ？ C and 14.96 bar, DEA/CO 2 molar flow ratio of 12.58, regeneration gas temperature and pressure of 94.92 ？ C and 3.0 bar, regenerator pressure of 1.53 bar, and ratio of DEA/MDEA = 20%/10% are the best values for minimizing plant energy consumption, amine circulation rate, and carbon dioxide recovery.

关键词： amine plant multiobjective optimization Non-Dominated Sorting Genetic Algorithm amine circulation rate

Ricci Symmetries of Static Space-Times with Maximal Symmetric Transverse Spaces

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Communications in Theoretical Physics 2008年第5期49卷 1229-1234页

作者： M.akbar Centre for Advanced Mathematics and Physics National University of Sciences and TechnologyPeshawar RoadRawalpindiPakistan

在纸[M。akbar 和 R.G 蔡， Commun。Theor。Phys。45 (2006 ) 95 ] ，一个完全的分类提供向量地 V 的至少一个部件是零。在这篇论文，我与所有非零部件认为向量地是 V，有最大的对称的横向的空格的静态的空间时间根据他们的 Ricci 关... 详细信息

在纸[M。akbar 和 R.G 蔡， Commun。Theor。Phys。45 (2006 ) 95 ] ，一个完全的分类提供向量地 V 的至少一个部件是零。在这篇论文，我与所有非零部件认为向量地是 V，有最大的对称的横向的空格的静态的空间时间根据他们的 Ricci 关口线条被分类。这些为非退化的 Ricci 张肌 det R ≠ 被调查0。结果唯一的关口线条由这些承认空格能是十，七，六或四。它也作为一个空间案例盖住我们的以前的结果。承认合适的 Ricci 关口线条的一些新度量标准也被调查。

关键词：爱因斯坦精确解最大相对空间相对论