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A microemulsion method for preparation of thiol-functionalized gold nanoparticles

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Particuology 2018年第2期16卷 33-36页

作者： somayeh Tianimoghadam Alireza Salabat Department of Chemistry Faculty of Science Lorestan University 68137-1-7133 Khorramabad Iran Department of Chemistry Faculty of Science Arak University 38156-8-8349 Arak Iran Institue of Nanosciences & Nanotechnolgy Arak University 38156-8-8349 Arak Iran

A new microemulsion method using tetraoctylammonium bromide as a cationic surfactant has been formulated to fabricate thiol-functionalized gold nanoparticles, The nanoparticles were compared with those synthesized by the multistep Brust two-phase *** nanoparticle sizes and size distributions fabricated by the two methods were characterized by UV-vis ahsorbance spectroscopy and transmittance electron microscopy. The simple microemulsion method produced the same results as those obtained by the Brust method,

关键词： Gold nanoparticles Brust method Microemulsion Thiol-functionalized gold

Exact Solutions of Five Complex Nonlinear Schr¨odinger Equations by Semi-Inverse Variational Principle

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Communications in Theoretical Physics 2014年第9期61卷 301-307页

作者： Mohammad Najafi somayeh Arbabi Medical Biology Research Center Kermanshah University of Medical SciencesKermanshah Iran

In this paper, we establish exact solutions for five complex nonlinear Schr¨odinger equations. The semiinverse variational principle(SVP) is used to construct exact soliton solutions of five complex nonlinear Schr¨odinger equations. Many new families of exact soliton solutions of five complex nonlinear Schr¨odinger equations are successfully obtained.

关键词： two-dimensional Schr¨odinger equation three-dimensional Schr¨odinger equation unstable Schr¨odinger equation

Application of the BASNEF Model in Safety Training in Automobile Manufacturing Plants

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Sound & Vibration 2022年第4期56卷 297-306页

作者： Fereydoon Laal Amir Hossein Khoshakhlagh Esmaeil Zarei Rohollah Fallah Madvari somayeh Farhang Dehghan Student Research Committee Department of Occupational Health and Safety EngineeringSchool of Public Health&SafetyShahid Beheshti University of Medical SciencesTehranIran Department of Occupational Health and Safety Engineering Social Determinants of Health Research CenterBirjand University of Medical SciencesBirjandIran Department of Occupational Health Engineering School of HealthKashan University of Medical SciencesKashanIran Department of Safety Science College of AviationEmbry-Riddle Aeronautical UniversityPrescottAZ86301USA Robertson Safety Institute(RSI) Embry-Riddle Aeronautical UniversityPrescottAZ86301USA Department of Occupational Health Engineering Occupational Health Research CenterSchool of Public HealthShahid Sadoughi University of Medical SciencesYazdIran Environmental and Occupational Hazards Control Research Center School of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran

After controls,including engineering and management,theﬁnal way to control noise is to use hearing protection *** ofastandardized questionnaireregarding investigatingworkers’use of hearing protection devices on the basis of the BASNEF behavioral model,the present study was conducted to investigate the effect of health education based on the BASNEF model on the use of hearing protection devices in workers of an auto-mobile manufacturing plant in *** quasi-experimental and prospective intervention study was performed on 80 workers at an automobile manufacturing plant who are exposed to noise levels above 85 decibels and donot use hearing protection *** this study,40 people working in a cast iron foundry were selected as the inter-vention group,and 40 working in aluminum casting were chosen as the control *** were ana-lyzed at the beginning of the intervention and three months after the intervention in the intervention and control *** was no signiﬁcant difference between the intervention and control groups before the *** was a signiﬁcant difference between the intervention and control groups after the intervention in the area of knowledge.A signiﬁcant correlation was observed between the intervention and control groups after the inter-vention program in all areas of the BASNEF educational model except behavioral *** this study,the effect of educational intervention on the use of hearing protection devices was investigated,and with the educa-tional intervention,it was tried to get help from inﬂuential people and enabling factors in education based on the BASNEF *** results showed that the educational intervention based on the BASNEF model can improve the knowledge of individuals in both the intervention and control groups.

关键词： Health education BASNEF model hearing protection devices automobile manufacturing plant

Dependence of Nitrogen/Argon Reaction Gas Amount on Structural,Mechanical and Optical Properties of Thin WNx Films

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Chinese Physics Letters 2017年第12期34卷 56-60页

作者： somayeh Asgary Amir Hoshang Ramezani Department of Physics West Tehran BranchIslamic Azad UniversityTehranIran

WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas *** data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.

关键词： SEM Mechanical and Optical Properties of Thin WN_x Films Dependence of Nitrogen/Argon Reaction Gas Amount on Structural

Comprehensive study of nanostructured supports with high surface area for Fischer-Tropsch synthesis

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Journal of Energy Chemistry 2013年第4期22卷 573-581页

作者： somayeh Farzad Ali Haghtalab Alimorad Rashidi Department of Chemical Engineering Tarbiat Modares University Nanotechnology Research Center Research Institute of Petroleum Industry (RIPI)

An extensive study of Fischer-Tropsch synthesis on nanostructure supports with high surface area such as nanostructure -y-alumina, single wall carbon nanotubes （SWNTs）, and the hybrid of SWNTs/nanostructure -y-alumina has been investigated. The nanostructure γ-alumina was promoted with lanthanum to obtain better performance of catalyst and 15 wt% cobalt loading was the basis of our investigation. Fischer- Tropsch synthesis was performed in a fixed bed reactor under different reaction conditions （220-240 ℃, 15-25 bar, H2/CO ratio of 2, GHSV of 900-1400） in order to study the effects of temperature, pressure and gas hourly space velocity （GHSV） changes on hydrocarbon selec- tivity and catalyst activity. The catalysts were extensively characterized by different methods including X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, inductively coupled plasma （ICP）, hydrogen （H2） chemisorption and temperature-programmed reduction （TPR）. The results showed that the yield of hybrid supported catalyst （55.4%） is higher than that of nanos- tructure -y-alumina supported catalyst （55.0%） and lower than that of SWNTs supported cobalt catalyst （71.0%）. The hybrid supported catalyst showed higher reduction degree and dispersion of cobalt particles. The temperature, pressure and GHSV effects on hybrid supported catalyst were studied and results showed that higher pressure favors the chain growth and temperature increase leads to the increases in methane selec- tivity and CO conversion. Higher hydrocarbon selectivity and CO conversion showed positive relationship with increasing GHSV while lower hydrocarbon selectivity diminishes.

关键词： Fischer-Tropsch synthesis single wall carbon nanotubes nanostructure γ-Al2O3 cobalt catalyst fixed bed reactor

Perovskites for Laser and Detector Applications

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Energy & Environmental Materials 2019年第2期2卷 146-153页

作者： Saunak Das somayeh Gholipour Michael Saliba Institute of Physical Chemistry(IPC) Friedrich Schiller University JenaHelmholtzweg 4Jena 07743Germany Leibniz Institute of Photonic Technology(IPHT) Albert-Einstein-Str.907745Jena Germany Adolphe Merkle Institute University of Fribourg CH 1700Switzerland Institute of Materials Science Technical University of DarmstadtD-64287Germany

Perovskite materials have triggered a renewed interest in photovoltaic research in the recent *** display crystal forms with 0D,1D and 2D,3D motifs,and several chemical forms,namely inorganic(titanates,rubidiates,nobiates,tantalates etc.),organic/inorganic metal halides with single to multiple cations,and even organic polymer or quantum dot-infused *** crystal type and chemical form are endowed with specific physicochemical,optical,electronic,and morphological *** unique properties render them suitable for targeted applications,namely photovoltaics,LEDs,photocatalysis/electrolysis/solar fuels/solar and Li-ion batteries,gas-sensors,ferroelectrics,capacitors,transistors and memristors,photodetectors,and lasers,for advanced quantum cryptography and outer space *** first,the crystal and material types,and physicochemical,morphological,and optoelectronic properties of perovskite materials are ***,we focus on those properties which cumulatively contribute to their application in the abovementioned ***,a comprehensive discussion about the advances in each field is ***/property/application relationships with key advances demonstrate the versatility of perovskites in modern optoelectronic technologies.

关键词： 2D perovskites hybrid perovskites micro-lasers X-ray detectors c-ray detectors

Numerical Solutions of Fractional Differential Equations by Using Fractional Taylor Basis

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IEEE/CAA Journal of Automatica Sinica 2017年第1期4卷 98-106页

作者： Vidhya Saraswathy Krishnasamy somayeh Mashayekhi Mohsen Razzaghi Department of Mathematics and Statistics Mississippi State University Department of Mathematics Florida State University

In this paper, a new numerical method for solving fractional differential equations(FDEs) is presented. The method is based upon the fractional Taylor basis approximations. The operational matrix of the fractional integration for the fractional Taylor basis is introduced. This matrix is then utilized to reduce the solution of the fractional differential equations to a system of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of this technique.

关键词： Caputo derivative fractional differential equations(FEDs) fractional Taylor basis operational matrix Riemann-Liouville fractional integral operator

Kaempferol attenuates cognitive deficit via regulating oxidative stress and neuroinflammation in an ovariectomized rat model of sporadic dementia

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Neural Regeneration Research 2018年第10期13卷 1827-1832页

作者： somayeh Kouhestani Adele Jafari Parvin Babaei Cellular and Molecular Research Center Faculty of MedicineGuilan University of Medical Sciences Department of Physiology Faculty of MedicineGuilan University of Medical Sciences Neuroscience Research Center Guilan University of Medical Sciences

Alzheimer＇s disease（AD） is associated with oxidative stress, and ultimately results in cognitive deficit. Despite existing literature on the pathophysiology of AD, there is currently no cure for AD. The present study investigated the effects of kaempferol（Kmp） isolated from the extract of Mespilus germanica L.（medlar） leaves on cognitive impairment, hippocampal antioxidants, apoptosis, lipid peroxidation and neuro-inflammation markers in ovariectomized（OVX） rat models of sporadic AD. Kaempferol, as the main flavonoid of medlar extract has been previously known for anti-oxidative, anti-inflammatory and anti-neurotoxic effects. Thirty-two female Wistar rats were ovariectomized, and randomly divided into four groups： sham, OVX ＋ saline, OVX ＋ streptozotocin（STZ）＋ saline, OVX ＋ STZ ＋ Kmp. Animals received intracerebroventricular injection of STZ（3 mg/kg, twice with one day interval） to establish models of sporadic AD. Intraperitoneal injection of Kmp（10 mg/kg） for 21 days was performed in the OVX ＋ STZ ＋ Kmp group. Spatial learning and memory of rats were evaluated using a Morris water maze. Finally, brain homogenates were used for biochemical analysis by enzyme-linked immunosorbent assay. The results showed a significant improvement in spatial learning and memory as evidenced by shortened escape latency and searching distance in Morris water maze in the OVX ＋ STZ ＋ Kmp group compared with the OVX ＋ STZ group. Kmp also exhibited significant elevations in brain levels of antioxidant enzymes of superoxide dismutase and glutathione, while reduction in tumor necrosis factor-α and malondialdehyde. Our results demonstrate that Kmp is capable of alleviating STZ-induced memory impairment in OVX rats, probably by elevating endogenous hippocampal antioxidants of superoxide dismutase and glutathione, and reducing neuroinflammation. This study suggests that Kmp may be a potential neuroprotective agent against cognitive deficit in AD.

关键词： Alzheimer's disease oxidative stress neuroinflammation Mespilus germanica L. Kaempferol neural regeneration

Design and analysis of superlens based on complex two-dimensional square lattice photonic crystal

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Chinese Optics Letters 2013年第10期11卷 83-86页

作者： somayeh Rafiee Dastjerdi Majid Ghanaatshoar Toshiaki Hattori Laser and Plasma Research Institute Shahid Beheshti University Institute of Applied Physics University of Tsukuba

We theoretically demonstrate the imaging properties of a complex two-dimensional(2D) face-centered square lattice photonic crystal(PC) made from germanium cylinders in air background. The finitedifference time-domain(FDTD) method is employed to calculate the band structure and simulate image construction. The band diagram of the complex structure is significantly compressed. Negative refraction occurs in the second energy band with negative phase velocity at a frequency of 0.228(2πc/a), which is lower than results from previous studies. Lower negative refraction frequency leads to higher image resolution. Numerical results show that the spatial resolution of the system reaches 0.7296λ, which is lower than the incident wavelength.

关键词： Design and analysis of superlens based on complex two-dimensional square lattice photonic crystal