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Particuology 2016年第6期14卷 143-153页

作者： Amit Goel Anu Mittal s.s. Mallick Atul sharma Department of Mechanical Engineering Thapar University Patiala Punjab 147004 India

This paper presents the results of an ongoing investigation into transient pressure pulses using shan- non entropy. Pressure fluctuations （produced by gas-solid two-phase flow during fluidized dense-phase conveying） are recorded by pressure transducers installed at strategic locations along a pipeline. This work validates previous work on identifying the flow mode from pressure signals （Mittal, Mallick, ＆ Wypych, 2014）. Two different powders, namely fly ash （median particle diameter 45 μm, particle den- sity 1950 kg/m3. loosely poured bulk density 950 kg/m3） and cement （median particle diameter 15 p,m, particle density 3060 kg/m3, loosely poured bulk density 1070 kg/m3）, are conveyed through different pipelines （51 mm I.D. × 70 m length and 63 mm I.D. × 24 m length）. The transient nature of pressure fluc- tuations （instead of steady-state behavior） is considered in investigating flow characteristics. shannon entropy is found to increase along straight pipe sections for both solids and both pipelines. However, shannon entropy decreases after a bend. A comparison of shannon entropy among different ranges of superficial air velocity reveals that high shannon entropy corresponds to very low velocities （i.e. 3-5 m/s） and very high velocities （i.e. 11-14 m/s） while low shannon entropy corresponds to mid-range velocities （i.e. 6-8 m/s）.

关键词： Transient pressure fluctuations Fluidized dense phase shannon entropy Flow pattern solid loading ratio superficial air velocity

Adaptations of phytoplankton in the Indian Ocean sector of the southern Ocean during austral summer of 1998-2014

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Frontiers of Earth science 2015年第4期9卷 742-752页

作者： R. k. MIsHRA R. k. NAIk N. ANIL kUMAR EssO-National Centre for Antarctic and Ocean Research Ministry of Earth Sciences (MoES) Vasco-da-Gama Goa India

This study investigates the effects of light and temperature on the surface water diatoms and chloro- phytes, phytoplankton in the Indian Ocean sector of the southern Ocean （sO） during the austral summer of 1998- 2014. significant longitudinal variations in hydrographic and biological parameters were observed at the sub tropical front （sTF）, sub Antarctic front （sAF） and Polar front （PF） along 56°E-58°E. The concentrations of total surface chlorophyll a （Chl a）, diatoms, and chlorophytes measured by the National Aeronautics space Agency （NAsA） estimated by the sea-Viewing Wide Field-of- View sensors （seaWiFs）, the Moderate Resolution Imaging spectro Radiometer （MODIs）, and the NAsA Ocean Biological Model （NOBM） were used in the study. Variations in the concentration of total Chl a was remarkable amongst the fronts during the study period. The contribution of diatoms to the total concentration of surface Chl a increased towards south from the sTF to the PF while it decreased in the case of chlorophytes. The maximum photosynthetically active radiation （PAR） was observed at the sTF and it progressively decreased to the PF through the sAF. At the PF region the contribution of diatoms to the total Chl a biomass was ≥80%. On the other hand, the chlorophytes showed a contrary distribution pattern with ≥ 70% of the total Chl a biomass recorded at the sTF which gradually decreased towards the PF, mainly attributed to the temperate adaptation. This clearly reveals that the trend of diatoms increased at the sTF and decreased at the sAF and the PF. Further, the trend of chlorophytes was increased at the sTF, sAF and PF with a shift in the community in the frontal system of the Indian Ocean sector of the sO.

关键词： chlorophyll a diatoms chlorophytes ssT,PAR southern Ocean

A numerical investigation on the seismic isolation potential of rubber/soil mixtures

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Earthquake Engineering and Engineering Vibration 2020年第3期19卷 683-704页

作者： G.A.Pistolas k.Pitilakis A.Anastasiadis Department of Civil Engineering Aristotle University of ThessalonikiGreece

This study examines the use of granular soils mixed with tire derived aggregates(TDA)as an underlying soil layer for surface *** benefit of this geotechnical seismic isolation(GsI)scheme is threefold:the seismic force and displacement are significantly reduced;the construction is similar to that of a regular compacted granular fill and the re-use of scrap tires has an assertive environmental *** features highlight the rubber/soil mixtures(RsM)as a promising seismic isolation technique for infrastructure and large-scale *** seismic isolation capabilities of a rubber-soil foundation layer are investigated,using well defined material properties,and the direct analysis method of the soil-structure system,in the form of a simple oscillator on a soil *** influence of the RsM layer on the fundamental variables of the seismic response,namely the base shear and the total drift displacement of the structure on deformable soil,is *** structure′s overall stability is studied by means of monotonic lateral load analysis and incremental dynamic analysis,varying the slenderness of the structure and the synthesis of the *** effectiveness and capabilities of the RsM isolation scheme are presented and discussed.

关键词： soil rubber seismic

Parallelized volumetric fluorescence microscopy with a reconfigurable coded incoherent light-sheet array

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Light(science & Applications) 2020年第1期9卷 1914-1924页

作者： Yu-Xuan Ren Jianglai Wu Queenie T.k.Lai Hei Ming Lai Dickson M.D.siu Wutian Wu kenneth k.Y.Wong kevin k.Tsia Department of Electrical and Electronic Engineering The University of Hong KongPokfulam RoadHong KongSAR 999077China Department of Physics University of CaliforniaBerkeleyCA 94720USA school of Biomedical sciences Li Ka Shing Faculty of MedicineThe University of Hong KongHong KongSAR 999077China Department of Psychiatry Faculty of MedicineThe Chinese University of Hong KongHong KongSAR 999077China GHM Institute of CNs Regeneration Jinan University601 Huangpu Avenue WestGuangzhou 510632China Re-stem Biotechnology Suzhou 215007China

Parallelized fluorescence imaging has been a long-standing pursuit that can address the unmet need for a comprehensive three-dimensional(3D)visualization of dynamical biological processes with minimal ***,the available approaches are limited to incomplete parallelization in only two dimensions or sparse sampling in three *** hereby develop a novel fluorescence imaging approach,called coded light-sheet array microscopy(CLAM),which allows complete parallelized 3D imaging without mechanical *** the concept of an“infinity mirror”,CLAM generates a light-sheet array with controllable sheet density and degree of ***,CLAM circumvents the common complications of multiple coherent light-sheet generation in terms of dedicated wavefront engineering and mechanical dithering/***,the encoding of multiplexed optical sections in CLAM allows the synchronous capture of all sectioned images within the imaged *** demonstrate the utility of CLAM in different imaging scenarios,including a light-scattering medium,an optically cleared tissue,and microparticles in fluidic *** can maximize the signal-to-noise ratio and the spatial duty cycle,and also provides a further reduction in photobleaching compared to the major scanning-based 3D imaging *** flexible implementation of CLAM regarding both hardware and software ensures compatibility with any light-sheet imaging modality and could thus be instrumental in a multitude of areas in biological research.

关键词： scattering light mirror

Analysing the combined effect of crystallographic orientation and grain refinement on mechanical properties and corrosion behaviour of ECAPed ZE41 Mg alloy

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Journal of Magnesium and Alloys 2020年第4期8卷 1128-1143页

作者： s.Prithivirajan s.Narendranath Vijay Desai Corrosion Engineering Lab Department of Mechanical EngineeringNational Institute of Technology KarnatakaSurcithkalSrinivasanagarMangalore 575025KarnatakaIndia

Two step equal channel angular pressing carried out on as cast ZE41 Mg alloy resulted in a remarkable grain *** compared to grain size of 46p.m in as cast sample,refinement upto 2.5^01 was achieved after 8th pass equal channel angular pressing(ECAP).The combined effect of crystallographic orientation and grain refinement was investigated by analysing the mechanical properties and corrosion behaviour of ZE41 Mg alloy using electron back scattered diffraction(EBsD).The first stage comprises of 1st,2nd,3rd and 4th passes at a processing temperature of 300℃while the 5th,6th,7th and 8th passes were ECAPed at 275℃in second *** mechanical properties of ZE41 Mg 158 yield tensile strength(YTs),230 ultimate tensile strength(UTs)and 7%elongation in as cast condition is enhanced to 236 YTs,295 UTs and 19.76%,respectively,after first stage *** yield tensile strength deteriorated due to the effect of texture predominating grain refinement during the second stage *** corrosion resistance of ZE41 Mg was significantly enhanced by ECAP and is inferred from electrochemical impedance spectroscopy(EIs)and potentiodynamic polarisation *** role of microstructure was minimal on corrosion behaviour of ZE41 Mg due to extra resistance when tested in 0M ***,the influence of grain refinement greatly influenced the improvement in corrosion resistance of ZE4I Mg rather than crystallographic orientation observed from *** contrast,the crystallographic orientation predominated the effect of grain refinement during ZE41 Mg corrosion in chloride containing(0.1 M and 1 M NaCl)*** the observation of results it is found that equal channel angular pressing has the dual advantage of improving mechanical properties and corrosion resista nee of ZE41 Mg alloy.

关键词： Corrosion EBsD Equal channel angular pressing Magnesium alloy

An investigation into flow mode transition and pressure fluctuations for fluidized dense-phase pneumatic conveying of fine powders

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Particuology 2014年第5期12卷 187-195页

作者： A.Mittal s.s.Mallick P.W.Wypych Department of Mechanical Engineering Thapar UniversityPatialaPunjab 147004India Faculty of Engineering and Information sciences University of WollongongWollongongNSW 2500Australia

This paper presents the results of an ongoing investigation into the fluctuations of pressure signals due to solids-gas flows for dense-phase pneumatic conveying of fine powders. Pressure signals were obtained from pressure transducers installed along different locations of a pipeline for the fluidized dense-phase pneumatic conveying of fly ash （median particle diameter 30μm; particle density 2300 kg/m^3; loose- poured bulk density 700 kg/m^3） and white powder （median particle diameter 55 p.m; particle density 1600 kg/m^3 ; loose-poured bulk density 620 kg/m^3） from dilute to fluidized dense-phase. standard deviation and shannon entropy were employed to investigate the pressure signal fluctuations. It was found that there is an increase in the values of shannon entropy and standard deviation for both of the prod- ucts along the flow direction through the straight pipe sections. However, both the shannon entropy and standard deviation values tend to decrease after the flow through bend（s）, This result could be attributed to the deceleration of particles while flowing through the bends, resulting in dampened particle fluctua- tion and turbulence. Lower values of shannon entropy in the early parts of the pipeline could be due to the non-suspension nature of flow （dense-phase）, i.e., there is a higher probability that the particles are concentrated toward the bottom of pipe, compared with dilute-phase or suspension flow （high velocity）, where the particles could be expected to be distributed homogenously throughout the pipe bore （as the flow is in suspension）. Changes in straight-pipe pneumatic conveying characteristics along the flow direction also indicate a change in the flow regime along the flow.

关键词： Fluidized dense-phase Pneumatic conveying Fine powders shannon entropy Flow transition Particle turbulence

A survey on control issues in renewable energy integration and microgrid

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Protection and Control of Modern Power systems 2019年第1期4卷 89-115页

作者： Faisal R.Badal Purnima Das subrata k.sarker sajal k.Das Department of Mechatronics Engineering Rajshahi University of Engineering and TechnologyKajlaRajshahi-6204Bangladesh

This paper describes the usefulness of renewable energy throughout the world to generate power. Renewable energy adds a remarkable scope in power system. Renewable energy sources act as the prime mover of a microgrid. The Microgrid is a small network of power system with distributed generation (DG) units connected in parallel. The integration challenges of renewable energy sources and the control of microgrid are described in this paper. The varied nature of DG system produces voltage and frequency deviation. The unknown nature of the load produces un-modeled dynamics. This un-modeled dynamic introduces measurable effects on the performance of the microgrid. This paper investigates the performance of the microgrid against different scenarios. The voltage of the microgrid is controlled by using different controllers and their results are also investigated. The performance of controllers is investigated using MATLAB/simulink simPowersystems.

关键词： Renewable energy Integral challenges Microgrid Control process Voltage control

单壁碳纳米管径向形变对介电常数和吸收光谱的影响

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人工晶体学报 2009年第3期38卷 638-641,647页

作者：王利光郭良王畅颜浩然 Terence k．s．W. 江南大学理学院无锡214122 黑龙江八一农垦大学理学院大庆163319 新加坡南洋理工大学电气与电子工程学院新加坡639798

采用广义梯度近似方法中的PBE（***、***和***）技术,对结构为（10,0）的锯齿型单壁碳纳米管在径向发生0.0-0.5扁率时的介电常数ε和光谱特性进行了理论研究。结果显示：（10,0）型单壁碳纳米管的径向形变对其介电常数峰值及光谱峰值的... 详细信息

采用广义梯度近似方法中的PBE（***、***和***）技术,对结构为（10,0）的锯齿型单壁碳纳米管在径向发生0.0-0.5扁率时的介电常数ε和光谱特性进行了理论研究。结果显示：（10,0）型单壁碳纳米管的径向形变对其介电常数峰值及光谱峰值的大小、位置和频率范围都有较大的影响。当入射光偏振方向垂直管轴时,介电常数峰值向低频区偏移,光谱峰值则依赖于初始位置。当入射光的偏振方向平行于管轴时,主要特征是介电常数幅值的变化和光谱范围的拓宽,同时,介电常数峰值向低频区偏移。

关键词：单壁碳纳米管径向形变广义梯度近似吸收光谱介电常数

Design of an Efficient Binary Vedic Multiplier for High speed Applications Using Vedic Mathematics with Bit Reduction Technique

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Circuits and systems 2016年第9期7卷 2593-2602页

作者： s. k. Manikandan C. Palanisamy Department of EEE Velalar College of Engineering and Technology Erode India Department of Information Technology Bannari Amman Institute of Technology Sathyamangalam India

Vedic mathematics is the system of mathematics followed in ancient Indian and it is applied in various mathematical branches. The word “Vedic” represents the storehouse of all knowledge. Because using Vedic Mathematics, the arithmetical problems are solved easily. The mathematical algorithms are formed from 16 sutras and 13 up-sutras. But there are some limitations in each sutra. Here, two sutras Nikhilam sutra and karatsuba algorithm are considered. In this research paper, a novel algorithm for binary multiplication based on Vedic mathematics is designed using bit reduction technique. Though Nikhilam sutra is used for multiplication, it is not used in all applications. Because it is special in multiplication. The remainder is derived from this sutra by reducing the remainder bit size to N-2 bit. Here, the number of bits of the remainder is constantly maintained as N-2 bits. By using karatsuba algorithm, the overall structure of the multiplier is designed. Unlike the conventional karatsuba algorithm, the proposed algorithm requires only one multiplier with N-2 bits only. The speed of the proposed algorithm is improved with balancing the area and the power. Even though there is a deviation in lower order bits, this method shows larger difference in higher bit lengths.

关键词： karatsuba Nikhilam sutra Bit Reduction Remainder Multipliers

Ambient Noise Tomography, Green’s Function and Earthquakes

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International Journal of Geosciences 2022年第12期13卷 1082-1088页

作者： Panayiotis k. Varotsos Efthimios s. skordas Department of Geology and Geoenvironment National and Kapodistrian University of Athens Athens Greece Department of Physics Section of Condensed Matter Physics and Solid Earth Physics Institute National and Kapodistrian University of Athens Athens Greece

Green’s function is well-known, among others, in the application of ambient noise tomography methodologies that may demonstrate the potential of hydrocarbon entrapment in the study area. Here it is also shown to be of key importance in identifying the fractal dimension in the unified scaling law for earthquakes as well as in studying an explicit relationship of a future strong earthquake epicenter to the average earthquake potential score. such studies are now in progress.

关键词： surface Wave Tomography shear Velocity Model Inversion Green’s Function Ambient Noise Earthquakes