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Gaussian Beam Propagation in a Kerr Type metamaterial medium Using ABCD matrix method

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Communications in Theoretical Physics 2016年第8期65卷 231-236页

作者： A.Keshavarz m.naseri Shiraz University of Technology Shiraz Iran

In this paper, a split step ABCD matrix method is suggested to investigate Gaussian beam propagation in a Kerr type metamaterial medium. This method is based on dividing the medium interval into subsequent ***, Gaussian beam profile in every step is obtained by finding the ABCD matrix of that particular step, and is used to find the ABCD matrix of the next step. Results of the suggested matrix method have been compared with the results of numerical split-step Fourier method for a Kerr medium, which indicates a good agreement. Then, we use the ABCD matrix to investigate Gaussian beams propagation in a Kerr type metamaterial, which is also in agreement with pervious results by other methods.

关键词： ABCD matrix method Kerr type metamaterials paraxial beam beam propagation

Fabrication of plain carbon steel/high chromium white cast iron bimetal by a liquid–solid composite casting process

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International Journal of minerals,metallurgy and materials 2015年第9期22卷 950-955页

作者： V.Javaheri H.Rastegari m.naseri Division of Research and Development Isfahan Casting Industries Co.(ICI) Department of Engineering Birjand University of Technology

High-chromium white cast iron （HCWCI） is one of the most widely used engineering materials in the mining and cement industries. However, in some components, such as the pulverizer plates of ash mills, the poor machinability of HCWCI creates difficulties. The bimetal casting technique is a suitable method for improving the machinability of HCWCI by joining an easily machined layer of plain carbon steel （PCS） to its hard part. In this study, the possibility of PCS/HCWCI bimetal casting was investigated using sand casting. The investigation was conducted by optical and electron microscopy and non-destructive, impact toughness, and tensile tests. The hardness and chemical composition profiles on both sides of the interface were plotted in this study. The results indicated that a conventional and low-cost casting technique could be a reliable method for producing PCSYdCWCI bimetal. The interfacial microstructure comprised two distinct lay- ers： a very fine, partially spheroidized pearlite layer and a coarse full pearlite layer. moreover, characterization of the microstructure revealed that the interface was free of defects.

关键词： bimetals carbon steel cast iron casting interfaces microstructure mechanical properties

Polypyrrole Chitosan Cobalt Ferrite Nanoparticles Composite Layer for measuring the Low Concentration of Fluorene Using Surface Plasmon Resonance

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Chinese Physics Letters 2017年第5期34卷 111-114页

作者： A.R.Sadrolhosseini m.naseri m.K.Halimah Department of Physics Faculty of ScienceMalayer University Department of Physics Faculty of ScienceUniversiti Putra Malaysia

Fluorene is a polycyclic aromatic hydrocarbon, which is a hazardous toxic chemical in the environment. The measurement of low concentrations of fluorene is a subject of intense interest in chemistry and in the environment. Polypyrrole chitosan cobalt ferrite nanoparticles are prepared using the electrochemical method. The prepared layers are characterized using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The layers are used to detect fluorene using the surface plasmon resonance technique at room temperature. The composite layer is evaluated after detection of fluorene using atomic force microscopy. The fluorene is bound on the layer, and the shift of the resonance angle is about 0.0052°, corresponding to the limitation of 0.01 ppm.

关键词： Co NP Polypyrrole Chitosan Cobalt Ferrite Nanoparticles Composite Layer for measuring the Low Concentration of Fluorene Using Surface Plasmon Resonance

Cognitive-emotional feasibility of the effect of visual quality of building form on promoting the sense of place attachment(Case study:Cultural iconic buildings of Iran’s contemporary architecture)

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Frontiers of Architectural Research 2024年第1期13卷 37-56页

作者： Narmin Ariannia Negar naseri mansour Yeganeh Digital Architecture and Artificial Intelligence Lab Department of ArchitectureTarbiat Modares UniversityTehranIran Architectural Design Modeling and Fabrication LabDepartment of ArchitectureTarbiat Modares UniversityTehranIran

The present research studies the relationship between place attachment and the perception of form’s visual quality in fifteen outstanding contemporary Iranian architectural cultural *** study puts forward the hypothesis that there is a correlation between the quality of building form and the sense of place attachment,in the sense that creating high visual quality through enhancing the quality of building form increases citizens’initial satisfaction with and subsequent attachment to the *** visual quality influences people’s experience of the environment and improves the quality of *** attachment highlights how people,on a personal level,recreate a sense of place for *** present study adopts the descriptive-analytical method as its theoretical framework and the survey as the empirical *** were developed using the Likert scale and distributed among experts and ordinary *** analysis using SPSS and the adoption of descriptive-analytical statistics,correlation analysis,and regression showed the relationship among the characteristics of *** results show a positive correlation between form and place attachment mediated through visual quality,and they are causal conditions for one *** addition,only some of the buildings under study evoke the same level of place attachment.

关键词： Visual preferences Environmental quality Environmental psychology mental schemas Contemporary architecture

大型柴油机高氮氧化物转化率的排放控制系统的研发

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汽车与新动力 2015年第5期47卷 43-50页

作者： m.naseri R.Conway H.Hess C.Aydin S.Chatterjee 左彤梅谷丽娟

选择性催化还原(SCR)系统已被证明是大型柴油机控制氮氧化物(NOx)排放的有效方案。未来的大型柴油机被设计为有更高的NOx排放量,以提高燃油经济性,这需要越来越高的NOx转化效率以满足排放法规要求。为此,未来的后处理设计可采用先进的技... 详细信息

选择性催化还原(SCR)系统已被证明是大型柴油机控制氮氧化物(NOx)排放的有效方案。未来的大型柴油机被设计为有更高的NOx排放量,以提高燃油经济性,这需要越来越高的NOx转化效率以满足排放法规要求。为此,未来的后处理设计可采用先进的技术,如选择性催化转化(SCR)涂覆颗粒滤清器(SCRF)和涂覆在高孔隙度直通式载体上的SCR,以获得高转化效率。评价了不同的高NOx转化效率系统。首先,通过使用SCRF单元和附加的涂覆在高孔隙度载体的SCR涂层,设计了高性能的NOx控制催化剂。第二,评价了不同的控制策略,以了解还原剂剂量策略和热管理对NOx转化效率的影响。在1台大型柴油机上进行瞬态循环试验。提高氨投入量而不是尿素可进一步提高转化效率,尤其是在低温下无法喷入尿素的时候。此外,实施热管理改善了低温时的NOx转化效率。结果证明,这种系统加上发动机控制策略的改进可以使瞬态FTP测试循环中的NOx转化效率达到95%以上,从而可使柴油机满足未来排放法规和燃油经济性的目标。

关键词：冷态循环预饱和处理热管理尿素转化效率

Frequency-dependent viscoelasticity effects on the wave attenuation performance of multi-layered periodic foundations

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 407-424页

作者： m.SAFI m.VAKILIFARD m.J.mAHmOODI Faculty of Civil Water&Environmental EngineeringShahid Beheshti UniversityTehran ***Iran Faculty of mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

In this paper,layered periodic foundations(LPFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency *** different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into ***,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss *** the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COmSOL *** parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse *** results show that considering the rubber viscoelasticity enhances the wave attenuation ***,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal *** 6-layer unit-cell LPF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关键词： layered metamaterial periodic foundation complex dispersion curve wave transmission diagram

Numerical Investigation of Effect of Inlet Swirl and Total-pressure Distortion on Performance and Stability of an Axial Transonic Compressor

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Journal of Thermal Science 2016年第6期25卷 501-510页

作者： A.naseri m.Boroomand S.Sammak Aerospace Engineering Department Amirkabir University of Technology

This paper represents numerical simulation of flow inside an axial transonic compressor subject to inlet flow distortion,to evaluate its effect on compressor performance and *** types of inlet distortion,namely inlet swirl and total pressure distortion are *** study the effect of combined distortion patterns,different combinations of inlet swirl and total pressure distortion are also *** for cases with total pressure distortion indicate that hub radial distortion improves stability range of the compressor while tip radial distortion deteriorates *** explanation for this observation is presented based on redistribution of flow parameters caused by distortion and the way it interacts with stall inception mechanisms in a transonic axial *** also show that while co-swirl patterns slightly improve stability range of the compressor,counter-swirl patterns diminish *** of combined distortion cases reveals that superimposition of effects of each individual pattern could predict the effect of a combined pattern on compressor's performance within an accuracy of 1%.However,it is unable to predict the associated effect on compressor's stability.

关键词： compressor stall distortion blade inlet axial radial rotor rotating counter

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： S.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： Semiconductor TiO_(2) Rare earths Congo red methylene blue Solar spectrum Photodegradation

Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVARI m.R.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis