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Plasma Science and Technology 2012年第11期14卷 996-1001页

作者： Vahid ABBASI ahmad gholami Kaveh NIAYESH High Voltage and Magnetic Material Research Center Electrical Engineering DepartmentIran University of Science and Technology School of Electrical and Computer Engineering University of Tehran

A three-dimensional （3-D） transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm＇s law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere＇s law, Ohm＇s law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl＇amework of time-dependent magnetohydrodynamic （MHD） equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma （these phenomena are related tO pinch effects and electromagnetic fields）. The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations.

关键词： magnetohydrodynamic (MHD) plasma deformation electromagnetic force kink instability sausage instability

The Effects of SF_6-Cu Mixture on the Arc Characteristics in a Medium Voltage Puffer Gas Circuit Breaker due to Variation of Thermodynamic Properties and Transport Coefficients

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Plasma Science and Technology 2013年第6期15卷 586-592页

作者： Vahid ABBASI ahmad gholami Kaveh NIAYESH Electrical Engineering Department Iran University of Science and TechnologyNarmakTehranIran School of Electical and Computer Engineering College of EngineeringUniversity of TehranIR-14395 TehranIran

In a gas circuit breaker,metal vapor resulting from electrode erosion is injected into the arc *** arc then burns in a mixture of SF;and electrode vapor,which has properties significantly different from those of pure SF;.Thermodynamic properties and transport coefficients of thermal plasmas formed in SF;-copper vapor mixtures change as a function of temperature and *** property that is mostly affected by the presence of copper is electrical conductivity,which is important in magnetohydrodynamic（MHD） *** this study,the transport coefficients of SF;in the presence of 10 percent copper are considered as the basis of MHD *** are made between the results during arc formation for pure SF;and SF;-Cu mixture in a medium voltage（MV） circuit *** to the transport coefficients influenced by the SF;-Cu mixture,the distribution of the electric potential, temperature,electromagnetic force density and current density of the arc column are presented and ***,the arc stability and pinch effect near current zero with 3-D simulation are investigated,which is advantageous to improving the efficiency of arc plasma simulation.

关键词： magnetohydrodynamic(MHD) electromagnetic force SF6-Cu mixture transport coefficients pure SF6

Bacterial nanotechnology as a paradigm in targeted cancer therapeutic delivery and immunotherapy

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Microsystems & Nanoengineering 2024年第4期10卷 43-85页

作者： ahmad gholami Milad Mohkam Saeede Soleimanian Mohammad Sadraeian Antonio Lauto Biotechnology Research Center Shiraz University of Medical SciencesShirazIran Department of Pharmaceutical Biotechnology Shiraz University of Medical SciencesShirazIran Allergy Research Center Shiraz University of Medical SciencesShirazIran Institute for Biomedical Materials and Devices(IBMD) Faculty of ScienceUniversity of Technology SydneySydneyNSW 2007Australia School of Science University of Western SydneyCampbelltownNSW 2560Australia School of Medicine University of Western SydneyCampbelltownNSW 2560Australia

Cancer,a multifaceted and diverse ailment,presents formidable obstacles to traditional treatment *** presents novel prospects for surmounting these challenges through its capacity to facilitate meticulous and regulated administration of therapeutic agents to malignant cells while concurrently modulating the immune system to combat *** and their derivatives have emerged as highly versatile and multifunctional platforms for cancer nanotherapy within the realm of *** comprehensive review delves into the multifaceted and groundbreaking implementations of bacterial nanotechnology within cancer *** review encompasses four primary facets:the utilization of bacteria as living conveyors of medicinal substances,the employment of bacterial components as agents that stimulate the immune system,the deployment of bacterial vectors as tools for delivering genetic material,and the development of bacteria-derived nano-drugs as intelligent ***,we elucidate the merits and modalities of operation pertaining to these bacterial nano-systems,along with their capacity to synergize with other cutting-edge nanotechnologies,such as CRISPR-Cas ***,we offer insightful viewpoints regarding the forthcoming trajectories and prospects within this expanding *** is our deduction that bacterial nanotechnology embodies a propitious and innovative paradigm in the realm of cancer therapy,which has the potential to provide numerous advantages and synergistic effects in enhancing the outcomes and quality of life for individuals afflicted with cancer.

关键词： neoplasms breaking realm

Effect of metal oxide arrester on the chaotic oscillations in the voltage transformer with nonlinear core loss model using chaos theory

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Chinese Physics B 2014年第1期23卷 480-488页

作者： Hamid Reza Abbasi ahmad gholami Seyyed Hamid Fathi Ataollah Abbasi Iran University of Science & Technology Electrical & Electronic Engineering Department Narmak *** Tehran Iran Amirkabir University Electrical Engineering Department Tehran 64540 Iran

In this paper, controlling chaos when chaotic ferroresonant oscillations occur in a voltage transformer with nonlin- ear core loss model is performed. The effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of voltage transformers is studied. The metal oxide arrester （MOA） is found to be effective in reducing ferroresonance chaotic oscillations. Also the multiple scales method is used to analyze the chaotic behavior and different types of fixed points in ferroresonance of voltage transformers considering core loss. This phenomenon has nonlinear chaotic dynamics and includes sub-harmonic, quasi-periodic, and also chaotic oscillations. In this paper, the chaotic behavior and various ferroresonant oscillation modes of the voltage transformer is studied. This phenomenon consists of different types of bifur- cations such as period doubling bifurcation （PDB）, saddle node bifurcation （SNB）, Hopf bifurcation （HB）, and chaos. The dynamic analysis of ferroresonant circuit is based on bifurcation theory. The bifurcation and phase plane diagrams are il- lustrated using a continuous method and linear and nonlinear models of core loss. To analyze ferroresonance phenomenon, the Lyapunov exponents are calculated via the multiple scales method to obtain Feigenbaum numbers. The bifurcation diagrams illustrate the variation of the control parameter. Therefore, the chaos is created and increased in the system.

关键词： ferroresonance chaos theory metal oxide arrester Lyapunov exponent

Assessment of drought hazard,vulnerability and risk in Iran using GIS techniques

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Journal of Arid Land 2020年第6期12卷 984-1000页

作者： Esmail HEYDARI ALAMDARLOO Hassan KHOSRAVI Sahar NASABPOUR ahmad gholami Department of Arid and Mountainous Regions Reclamation Faculty of Natural ResourcesUniversity of TehranTehran 31587-77871Iran Department of Organic&Polymer Chemistry Faculty of ChemistryKharazmi UniversityTehran 15719-14911Iran

The drought has enormous adverse effects on agriculture,water resources and environment,and causes damages around the *** risk assessment and prioritization of drought management can help decision makers and planners to manage the adverse effects of *** paper aims to determine the risk of drought in *** the first stage,standardized precipitation index(SPI)was calculated for the period 1981–*** the probability map of different drought classes or drought hazard probability map were *** that the indicator-based vulnerability assessment method was used to determine the drought vulnerability *** indices including climate,topography,waterway density,land use and groundwater resources were chosen as the most critical factors of drought in Iran and followed by the analytical hierarchy process questionnaire,the weights of each index were obtained based on expert *** membership maps of each index and sub-index were prepared using ArcGIS *** drought vulnerability map of Iran was plotted using these weights and maps of each ***,the drought risk map of Iran was provided by multiplying drought hazard and vulnerability *** to the 43-completed questionnaires by experts,climate index has the highest vulnerability to *** does not have an important role in drought hazard index,but it is the most crucial factor to classified drought vulnerability *** results showed that central,northeast,southeast and west parts of Iran are at high risks of *** are regions with different risks in Iran due to unusual weather and climatic *** realized that the climate and the groundwater situation is almost the same in the central,east and south parts of Iran,because the land use plays a crucial role in the drought vulnerability and risk in these *** drought risk decreases from the center of Iran to the southwest and northwest.

关键词： climate map standardized precipitation index analytical hierarchy process fuzzy membership weight

Comparative Study on Characteristics and Cytotoxicity of Bifunctional Magnetic-Silver Nanostructures: Synthesized Using Three Different Reducing Agents

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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 326-334页

作者： Narjes Ebrahimi Sara Rasoul-Amini Alireza Ebrahiminezhad Younes Ghasemi ahmad gholami Hassan Seradj Department of Pharmaceutical Biotechnology School of Pharmacy Shiraz University of Medical Sciences Department of Medicinal Chemistry School of PharmacyShiraz University of Medical Sciences Shiraz Fars Iran Pharmaceutical Sciences Research Center Shiraz University of Medical Sciences Department of Medical Biotechnology School of MedicineFasa University of Medical Sciences Department of Pharmacognosy School of Pharmacy Shiraz University of Medical Sciences

Magnetic-silver nanostructures were synthesized via optimized chemical conditions, and their characteristics and cytotoxicity were compared as candidates for the magnetic delivery of silver nanoparticles toward cancer cells. Magnetic-silver nanostructures were prepared through the reduction of silver ions in the presence of iron oxide nanoparticles using three different reducing agents （glucose, maltose and sodium citrate）. Their physicochemical characteristics were determined using ultraviolet-visible spectroscopy, X-ray diffraction analysis, transmission electron microscopy, selected area electron diffraction analysis, Fourier transformed infrared spectroscopy, atomic absorption spectroscopy, vibrating sample magnetometry and differential scanning calorimetry. Cytotoxic activities were evaluated against a human liver hepatocellular carcinoma cell line. Fabricated nanostructures, which exhibit differences in size, silver content, magnetic saturation value and cytotoxicity, represent sufficient superparamagnetic properties and considerable cytotoxicity to be suggested as effective tools in magnetic targeting of silver nanoparticles as an approach to cancer therapy.

关键词： Bifunctional nanostructure Magnetic-silver nanostructure Silver nanoparticle Cytotoxicity Reducing agent

Exploring the potential and safety of quantum dots in allergy diagnostics

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Microsystems & Nanoengineering 2023年第6期9卷 1-23页

作者： Milad Mohkam Mohammad Sadraeian Antonio Lauto ahmad gholami Seyed Hesamodin Nabavizadeh Hossein Esmaeilzadeh Soheila Alyasin Allergy Research Center Shiraz University of Medical SciencesShirazIran Institute for Biomedical Materials and Devices(IBMD) Faculty of ScienceUniversity of Technology SydneySydneyNSW2007Australia School of Science University of Western SydneyCampbelltownNSW2560Australia School of Medicine University of Western SydneyCampbelltownNSW2560Australia Biotechnology Research Center Shiraz University of Medical SciencesShirazIran Department of Pharmaceutical Biotechnology School of PharmacyShiraz University of Medical SciencesShirazIran Department of Allergy and Clinical Immunology Namazi HospitalShiraz University of Medical SciencesShirazIran

Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved *** dots(QDs)are promising nanomaterials that possess a wide array of advantageous properties,including electronic properties,optical properties,and engineered biocompatibility under physiological *** to these characteristics,QDs are mainly used for biomedical labeling and theranostic(therapeutic-diagnostic)*** can be functionalized with ligands to facilitate their interaction with the immune system,specific IgE,and effector cell ***,undesirable side effects such as hypersensitivity and toxicity may occur,requiring further *** review systematically summarizes the potential uses of QDs in the allergy *** overview of the definition and development of QDs is provided,along with the applications of QDs in allergy studies,including the detection of allergen-specific IgE(sIgE),food allergens,and sIgE in cellular *** potential treatment of allergies with QDs is also described,highlighting the toxicity and biocompatibility of these ***,we discuss the current findings on the immunotoxicity of *** favorable points regarding the use of QDs for allergy diagnosis and treatment are noted.

关键词： allergy diagnosis potential

Analysis of Chaotic Ferroresonance Phenomena in Unloaded Transformers Including MOV

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Energy and Power Engineering 2011年第4期3卷 478-482页

作者： Ataollah Abbasi Mehrdad Rostami ahmad gholami Hamid R. Abbasi 不详

We study the effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of transformers. It is expected that the arresters generally cause ferroresonance drop out. Simulation has been done on a three phase power transformer with one open phase. Effect of varying input voltage is studied. The simulation results reveal that connecting the arrester to transformers poles, exhibits a great mitigating effect on ferroresonant over voltages. Phase plane along with bifurcation diagrams are also presented. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos and magnitude of ferroresonant voltages is obtained, shown and tabulated.

关键词： Power Transformer Phase Plane Diagram Bifurcation Diagram Chaotic Ferroresonance

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 101-122页

作者： M.gholami M.EFTEKHARI Department of Mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGM) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGM pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGM composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGM porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

关键词： Galerkin methods

Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1887-1897页

作者： Hamed gholami Bahram Rezai ahmad Hassanzadeh Akbar Mehdilo Mohammadreza Yarahmadi Department of Mining and Metallurgical Engineering Amirkabir University of TechnologyTehran 158754413Iran Department of Geoscience and Petroleum Faculty of Engineering ScienceNorwegian University of Science and TechnologyNO-7491TrondheimNorway Faculty of Engineering University of Mohaghegh ArdabiliArdabil ***Iran Research and Development Division Sarcheshmeh Copper MineNational Iranian Copper Industries CompanyRafsanjanIran

The present study initially investigates the kinetics of microwave-assisted grinding and flotation in a porphyry copper *** tests were conducted on untreated and microwave-irradiated samples by varying the exposure time from 15 to 150 *** microscopy,energy-dispersive X-ray spectroscopy,and scanning electron microscopy were conducted to determine the mineral liberation and particle surface properties,and to perform mineralogical *** showed that the ore breakage rate constant monotonically increased by increasing the exposure time,particularly for the coarsest fraction size(400μm)due to the creation of thermal stress fractures alongside grain *** irradiation time(>60 s)led to the creation of oxidized and porous surfaces along with a dramatic change in particle morphologies that result in a substantial reduction of chalcopyrite and pyrite flotation rate constants and ultimate *** concluded that MW-pretreated copper ore was ground faster than the untreated variety,but the two types have slightly similar floatabilities.

关键词： grinding microwave copper