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Suitable triggering algorithms for detecting strong ground motions using MEMS accelerometers

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Earthquake Engineering and Engineering Vibration 2015年第1期14卷 27-35页

作者： Ravi Sankar Jakka siddharth Garg Department of Earthquake Engineering Indian Institute of Technology

With the recent development of digital Micro Electro Mechanical System （MEMS） sensors, the cost of monitoring and detecting seismic events in real time can be greatly reduced. Ability of MEMS accelerograph to record a seismic event depends upon the efficiency of triggering algorithm, apart from the sensor＇s sensitivity. There are several classic triggering algorithms developed to detect seismic events, ranging from basic amplitude threshold to more sophisticated pattern recognition. Algorithms based on STA/LTA are reported to be computationally efficient for real time monitoring. In this paper, we analyzed several STA/LTA algorithms to check their efficiency and suitability using data obtained from the Quake Catcher Network （network of MEMS accelerometer stations）. We found that most of the STA/LTA algorithms are suitable for use with MEMS accelerometer data to accurately detect seismic events. However, the efficiency of any particular algorithm is found to be dependent on the parameter set used （i.e., window width of STA, LTA and threshold level）.

关键词： strong ground motion triggering algorithms seismic event detection MEMS accelerometers STA/LTA based algorithms

Tidal force effects and bound orbits in null naked singularity spacetime

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Chinese Physics C 2024年第11期48卷 193-202页

作者： siddharth Madan Parth Bambhaniya P.D.Patel Institute of Applied Sciences Charusat UniversityAnand-388421GujaratIndia International Centre for Space and Cosmology School of Arts and SciencesAhmedabad UniversityAhmedabad 380009GujaratIndia

Naked singularities form during the gravitational collapse of inhomogeneous matter *** final nature of the singularity depends on the initial conditions of the matter properties and types of matter *** naked singularities can also be divided into two types:null-like and timelike *** spacelike singularity of the Schwarzschild black hole can be distinguished from the null and timelike naked singularity *** light of this,we investigate the precession of timelike bound orbits in the null naked singularity spacetime,as well as tidal force effects and geodesic deviation *** a result,we find that the orbital precession of the timelike bound orbits in null naked singularity spacetime could be distinguished from the Schwarzschild precession *** radial component of the tidal force has an intriguing profile,whereas the angular component has a profile that is comparable to that of a Schwarzschild black hole *** geodesic deviation equation is then solved numerically,yielding results that resemble Schwarzschild black *** characteristic features can then be used to discern among these singularities.

关键词： black hole naked singularity tidal force bound orbits

Thermodynamic limits for simultaneous energy harvesting from the hot sun and cold outer space

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Light(Science & Applications) 2020年第1期9卷 1373-1383页

作者： Wei Li siddharth Buddhiraju Shanhui Fan Department of Electrical Engineering Ginzton LaboratoryStanford UniversityStanfordCA 94305USA

The sun and outer space are two of the most important fundamental thermodynamic resources for renewable energy harvesting.A significant amount of work has focused on understanding the fundamental limit of energy harvesting from the *** recently,there have been several theoretical analyses of the fundamental limit of energy harvesting from outer ***,far less is understood about the fundamental limits of simultaneous energy harvesting from both the sun and outer ***,we consider and introduce various schemes that are capable of simultaneous energy harvesting and elucidate the fundamental thermodynamic limits of these *** show that the theoretical limits can far exceed the previously established limit associated with utilizing only one thermodynamic *** results highlight the significant potential of simultaneous energy harvesting and indicate new fundamental opportunities for improving the efficiency of energy harvesting systems.

关键词： outer harvesting simultaneous

Investigation of cubic Pt alloys for ammonia oxidation reaction

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Nano Research 2020年第7期13卷 1920-1927页

作者： Yat Tung Chan Kumar siddharth Minhua Shao Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

As a promising fuel candidate,ammonia has been successtully used as anode feed in alkaline fuel ***,current technology in catalysts for ammonia electro-oxidation reaction(AOR)with respect to both cost and performance is inadequate to ensure large scale commercial application of direct ammonia fuel *** studies found that alloying Pt with different transition metals and controlling the morphology of catalysts can improve the AOR activity,and thus potentially can solve the cost ***,(100)-terminated Pt-M nanocubes(M=3d-transition metals Fe,Co,Ni,Zn)are synthesized via wet-chemistry method and their catalytic activities toward AOR are *** addition of Fe,Co,Ni and Zn elements can enhance the AOR activity due to decrease in oxophilicity of platinum and bifunctional ***-Zn exhibits the maximum mass activity and specific ativity with values of 0.41 A/mgpt and 169 mA/cm2 that are 1.6 and 1.8 times higher than Pt nanocubes,***-Fe,Pt-Co and PI-Ni nanocubes also ilustrate higher mass and specific activities compared to Pt nanocubes.

关键词： ammonia oxidation reaction electrocatalysts Pt-3d transition metal nanocubes OH adsorption

Review of Energy Management and Planning of Islanded Microgrids

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CSEE Journal of Power and Energy Systems 2020年第2期6卷 329-343页

作者： Alexander A.Anderson siddharth Suryanarayanan EmpowerPack SPC North BendWA 98045 USA Department of Electrical Engineering Colorado State UniversityFort CollinsCO 80523 USA

This survey paper provides a critical overview of optimization formulations for planning and operation of islanded microgrids,including optimization objectives,constraints,and control *** optimization approaches reviewed address methods both for increasing the resiliency of advanced distribution systems and electrification of remote *** paper examines over 120 individual optimization studies and discovers that all optimizations studies of islanded microgrids are based on formulations selecting a combination of 16 possible objective functions,14 constraints,and 13 control *** of the objectives,constraints,and variables are discussed exhaustively both from the perspective of their importance to islanded microgrids and chronological trends in their popularity.

关键词： Energy system planning islanded microgrids multi-objective optimization power system operation renewables forecasting

Application and Improvements of the Wing Deformation Capture with Simulation for Flapping Micro Aerial Vehicle

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Journal of Bionic Engineering 2020年第6期17卷 1096-1108页

作者： Wee-Beng Tay siddharth Jadhav Jian-Lei Wang Centre for Aerodynamics&Propulsion Temasek LaboratoriesNational University of SingaporeSingapore 117411Republic of Singapore Shaanxi Aerospace Flight Vehicle Design Key Laboratory School of AstronauticsNorthwestern Polytechnical UniversityXi'an 710072China

Wing deformation capture with simulation is a mixed experimental-numerical approach whereby the wing deformation during flapping is captured using high-speed cameras and used as an input for the numerical *** is an alternative approach compared to pure experiment or full fluid structure interaction *** study is an update to the previous paper by Tay et al.,which aims to address the previous *** show through thrust and vorticity contour plots that this approach can simulate Flapping Micro Aerial Vehiclex(FMAVs)with reasonable ***,we use this approach to explain the thrust improvement when an additional rib is added to the original membrane wing,which is due to longer duration for the new wing to open during the fling ***,by decreasing the number of points and frames per cycle on the wing,we can simplify and shorten the digitization *** results show that this approach is an accurate and practical alternative which can be applied to general bio-inspired research.

关键词： flapping MAV immersed boundary method wing deformation membrane wings

Graph theory approach to determine configurations of multidentate and high coverage adsorbates for heterogeneous catalysis

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npj Computational Materials 2020年第1期6卷 998-1003页

作者： siddharth Deshpande Tristan Maxson Jeffrey Greeley Davidson School of Chemical Engineering Purdue University480 W Stadium Mall DriveWest LafayetteIN 47907USA

Heterogeneous catalysts constitute a crucial component of many industrial processes,and to gain an understanding of the atomicscale features of such catalysts,ab initio density functional theory is widely ***,growing computational power has permitted the extension of such studies to complex reaction networks involving either high adsorbate coverages or multidentate adsorbates,which bind to the surface through multiple *** all possible adsorbate configurations for such systems,however,is often not possible based on chemical intuition *** systematically treat such complexities,we present a generalized Python-based graph theory approach to convert atomic scale models into undirected graph *** representations,when combined with workflows such as evolutionary algorithms,can systematically generate high coverage adsorbate models and classify unique minimum energy multidentate adsorbate configurations for surfaces of low symmetry,including multi-elemental alloy surfaces,steps,and kinks.

关键词： configuration theory catalysis

Study of the Geometry and Folding Pattern of Leaves of Mimosa pudica

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Journal of Bionic Engineering 2007年第1期4卷 19-23页

作者： H. S. Patil siddharth Vaijapurkar Department of Applied Mechanics S.V. National Institute of Technology Ichchanath Surat Gujarath 395007 India

Many structural and functional properties possessed by plants have great potentials to stimulate new concepts and innovative ideas in the field of biomimetic engineering. The key inputs from biology can be used for creation of efficient and optimized structures. The study of the geometry and folding pattern of leaves of Mimosa pudica, referred as Sensitive Plant, reveals some of the peculiar characteristics during folding and unfolding. When the leaf is touched, it quickly folds its leaflets and pinnae and droops downward at the petiole attachment. With the help of experiments on simulation model, the variations in angle of leaflets and degree of compaction after folding are investigated.

关键词： bionics biomimetics folding geometry leaves Mimosa pudica

Dispersion Management with Higher Order Mode Fibers

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光学学报 2003年第S1期23卷 573-574页

作者： siddharth Ramachandran OFS Laboratories 600 Mountain Avenue Murray Hill NJ-07974 USA

Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low non-linearity of this technology can improve system OSNR, leading to enhancements in transmission distances.

关键词： mode or that DCM Dispersion Management with Higher Order Mode Fibers OSNR DCF with than been RDS of MPI