Femtosecond Laser Fabricated All-Optical Fiber Sensors With Ultrahigh Refractive Index Sensitivity: Modeling And Experiment,
2011
Missouri University of Science and Technology
Femtosecond Laser Fabricated All-Optical Fiber Sensors With Ultrahigh Refractive Index Sensitivity: Modeling And Experiment, Lan Jiang, Longjiang Zhao, Sumei Wang, Jinpeng Yang, Hai Xiao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
All-optical fiber sensors based on ultracompact fiber inline Mach-Zehnder interferometer (MZI) are fabricated by side-ablating a Ushape microcavity in a single-mode optical fiber with the fiber core partially removed using femtosecond (fs) laser pulses, in which the two light paths are accordingly formed in the remaining D-type fiber core and the U-shape microcavity. Beam propagation method (BPM) analysis is utilized to illustrate the dependences of good transmission spectra on parameters including the ablation depth, ablation length and the refractive index of Ushape microcavity, which gives some guidelines to optimize parameters for fs laser micromachining and predicts RI (refractive index) sensitivities …
Electrochemical Performance Of Tin Dioxide/Carbon Xerogel Composites As Anode Materials For Lithium-Ion Batteries,
2011
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry,College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Electrochemical Performance Of Tin Dioxide/Carbon Xerogel Composites As Anode Materials For Lithium-Ion Batteries, Xiao-Jing Liu, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
The tin dioxide/carbon xerogel composites were synthesized by using vacuum infiltration method. Structural characterization and morphology of the composites were investigated by using XRD, TEM and SEM techniques. BET test was performed to determine the pore size distributions of carbon xerogels and the composites. The results showed that the nano-sized SnO2 particles (5~10 nm) were encapsulated in the pores of carbon xerogels. During the electrochemical tests the SnO2 in the composites exhibited capacity retention of 61.9% after 100 cycles of charge-discharge tests at 100 mA/g.
Synthesis And Electrochemical Behaviors Of Li2Coxmn1-XSio4 As A Cathode Material For Lithium-Ion Batteries,
2011
State Key Laboratory of Physical Chemistry of Solid Surfaces , College ofChemistry and ChemicalEngineering,Xiamen University, Xiamen 361005,Fujian, China
Synthesis And Electrochemical Behaviors Of Li2Coxmn1-XSio4 As A Cathode Material For Lithium-Ion Batteries, Lin Wang, Dong-Ping Lv, Yong Yang
Journal of Electrochemistry
We have successfully synthesized Li2CoxMn1-xSiO4/C (x=0, 0.1, 0.3, 0.5, 1)/C composites using hydrothermal assisted sol-gel process and ball-milling method. The results of X-ray diffraction show that the solid solutions of Li2CoxMn1-xSiO4 can be achieved when x≤0.3. The initial capacities increase from 70 mAh·g-1 of Li2MnSiO4/C to 105 mAh·g-1 of Li2Co0.3Mn0.7SiO4/C. Cyclic Voltammetry (CV) curves show that the replacement of Mn with Co can reduce the electrochemical polarization, making the insertion-extraction reaction …
Study On Residual Powders Of Lithium-Ion Batteries With Different Voltages After Explosion,
2011
Tianjin Lishen Battery Joint-Stock CO., LTD, Tianjin 300384, China;
Study On Residual Powders Of Lithium-Ion Batteries With Different Voltages After Explosion, He Li, Zhi-Kui Chen, Ji-Na Cao, Guang-Chuan Liang
Journal of Electrochemistry
The residual powders of lithium-ion batteries at different voltages after explosion were obtained by using the battery impact testing machine. And these powders have been investigated by weighing, water solution and X-ray diffraction (XRD). The results showed that the integrity status of copper current collector and weight of residual powders decreased gradually with increasing of battery voltage, rising of burning temperature and releasing of burning duration time. The residual powders could be separated to insoluble powders and soluble powders by the water solution. The proportion of the insoluble powders is more (about 90%) including C, Co and CoO, while the …
Study On The Fluorescent Carbon Nanodots With Electrochemical Methods,
2011
College of Chemistry and Molecular Seiences, Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), and Wuhan Institute of Biotechnology, Wuhan University, Wuhan 430072, China
Study On The Fluorescent Carbon Nanodots With Electrochemical Methods, Bao-Ping Qi, Yan-Min Long, Lei Bao, Cui Liu, Zhi-Ling Zhang, Dai-Wen Pang
Journal of Electrochemistry
Carbon nanodots are a new class of fluorescent nanoparticles with a carbon-based core, which possess wavelength-tunable luminescence, high photostability, resistance to photobleaching, water-solubility, and ease of bioconjugation. Owing to their attractive merits, carbon nanodots like other carbon nanomaterials such as fullerene, carbon nanotubes and graphene, have attracted much attention. In addition, carbon nanodots can be inexpensively produced by electrochemical methods with simple post-processing under mild conditions. Electrochemical approaches have unique advantages in the analysis of surface structures and luminescence mechanism of materials. In this review, recent advances in electrochemical methods used for the synthesis and luminescence mechanism of fluorescent carbon …
Study On The Electrochemical Behaviors Of Gc Electrode Modified With Carbon Nanotube-Polyelectrolytes And Its Application For Rutin Detection,
2011
Chemistry Department, Shanghai Normal University, Shanghai 200234, China
Study On The Electrochemical Behaviors Of Gc Electrode Modified With Carbon Nanotube-Polyelectrolytes And Its Application For Rutin Detection, Liang Hua, Xia-Qin Wu, Rong Wang
Journal of Electrochemistry
The electrochemical behaviors of rutin and ascorbic acid at single-wall carbon nanotube and polyelectrolytes (dimethyl-diallylammonium chloride, PDDA) film modified glassy carbon electrode was investigated. The cyclic voltammetric results showed that electron transfer of rutin at PDDA/SWCNTs/GC modified electrode is an adsorption-controlled process. The separation of oxidation peak potentials of rutin and ascorbic acid was more than 200 mV. The rutin concentration in the presence of AA were detected by differential pulse voltammetry (DPV). The experimental results indicated that the PDDA/SWCNTs/GC modified electrode can be used for the detection of rutin in the presence of high concentration of AA. The DPV …
Synthesis Of Limnpo4/C Used As Cathode Material For Lithium Ion Batteries,
2011
Dalian University of Technology School of Chemical Engineering School of Petrochemical Engineering, Dalian,116024;
Synthesis Of Limnpo4/C Used As Cathode Material For Lithium Ion Batteries, Xin Yang, Xue-Wu Liu, Gui-Chang Liu, Zhi-Cong Shi, Xin Li, Guo-Hua Chen
Journal of Electrochemistry
The LiMnPO4/C composites were prepared using a solid-state reaction with addition of the resorcinol formaldehyde resin as the carbon source. The effects of reaction temperature and time on the crystal structure, morphology and electrochemical properties of the LiMnPO4/C composites were investigated. The results show that the best performance was achieved with the LiMnPO4/C composites synthesized at 600 oC for 12 h which had the particle sizes about 100~200 nm. The initial discharge capacities were 121.6 mAh·g-1 at 0.02C, 110 mAh·g-1 at 0.1C and more than 60 mAh·g-1 at 1C. An …
Electrelectrochemical Performances Of C-Coating And Co-Doping Lifepo4,
2011
Key Laboratory of Photovoltaic Materials of Henan Province and School of Physics & Electronics, Henan University,Kaifeng 475004, Henan, China
Electrelectrochemical Performances Of C-Coating And Co-Doping Lifepo4, Ying Bai, Jue-Ming Yang, Chun-Bo Qing, Wei-Feng Zhang
Journal of Electrochemistry
Phospho-olivine LiFePO4 cathode materials were prepared by hydrothermal reaction at 200 oC. Sucrose was added as C-coating resource and Co was doped into the crystal lattice of LiFePO4. In order to investigate the improvements in the electrochemical properties of Co-doped LiFePO4, three samples, LiFePO4, C-coated LiFePO4 and C-coating-Co-doped LiFePO4, were synthesized under the same preparation conditions. Charge/discharge studies reveal that the Co-doped LiFePO4/C composite annealed at 400 oC exhibits marked improvement of specific capacity by diminishing the particle sizes and enhancement in the degree of crystallinity. …
Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material,
2011
Key Laboratory of Analytical Chemistry for Life Science (MOE), School of Chemistry andChemical Engineering, Nanjing University, Nanjing 210008, China
Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material, Zhen-Zhen Zhao, Wen-Bin Ni, Neng-Yue Gao, Hong-Bo Wang, Jian-Wei Zhao
Journal of Electrochemistry
The enhanced electrochemical properties of Ni(OH)2 by the oxidation defected graphene were studied by both experimental method and theoretical calculation. The composite material of nano-Ni(OH)2/graphene was prepared by potentiostatic deposition on the graphene substrate. Observed by TEM, the Ni(OH)2 nanoparticles were well dispersed on the graphene substrate with the diameter of 5.0±0.5 nm. The capacitance of the system measured by the electrochemical test was 1928 F·g-1. As indicated by the theoretical calculations, the composite material becomes conductive since Ni(OH)2 is combined with surface functional groups of the graphene through the strong chemical interaction. …
Active Impedance Matching And Sensitivity Optimized Phased Array Feed Design For Radio Astronomy,
2011
Brigham Young University - Provo
Active Impedance Matching And Sensitivity Optimized Phased Array Feed Design For Radio Astronomy, David E. Carter
Theses and Dissertations
One of the many challenges in radio astronomy is the ability to make accurate measurements quickly. In recent years engineers and astronomers have begun implementing phased array feeds (PAFs) as a way to negate the long observation times required by single antenna feeds. Unfortunately, large mutual coupling and other loss terms result in low sensitivity, restricting PAF usefulness in on dish observation. This thesis addresses several ways to reduce mutual coupling and maximize sensitivity for PAFs in radio astronomy. Antenna design of this magnitude requires accurate modeling capabilities. To this end, electromagnetic software models and low loss component designs are …
Light Extraction Improvement Of Gan Leds Using Nano-Scale Top Transmission Gratings,
2011
California Polytechnic State University - San Luis Obispo
Light Extraction Improvement Of Gan Leds Using Nano-Scale Top Transmission Gratings, Greg Chavoor, Xiaomin Jin, Ashton Ellaboudy, Xing-Xing Fu, Xiang-Ning Kang, Bei Zhang, Guo-Yi Zhang
Electrical Engineering
In this paper, we use a Finite-Difference Time-Domain GaN LED model to study constant wave (CW) average power of extracted light. The structure simulated comprises of a 200nm-thick p-GaN substrate, 50nm-thick MQW, 400nm-thick n-GaN substrate, and a 200nm n-GaN two-dimensional Photonic Crystal(2PhC) grating. We focus on optimizing three design parameters: grating period (A), grating height (d), and fill factor (FF). In the primary set of simulations, we fix the fill factor at 50% and simulate ten different grating periods (100 to 1000nm in steps of 100nm) and four different grating heights (50 to 200nm in steps of 50nm), and calculate …
Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs),
2011
University of Connecticut - Storrs
Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward
Master's Theses
This study focuses on both the numerical and experimental investigations of the novel, passively operated, tubular-shaped, Direct Methanol Fuel Cell (DMFC) as an alternative geometry to the traditional planar-shaped fuel cell. The benefit of the tubular geometry compared to the planar geometry is the higher instantaneous volumetric power density provided by the larger active area, which could be beneficial in applications that require a high instantaneous power while occupying a small volume. First, a two-dimensional, two-phase, non-isothermal model was developed to investigate the steady-state performance and design characteristics of a tubular-shaped, passive DMFC. It was found that a higher ambient …
Improvement Of Solar Cell Efficiency Using Nano-Scale Top And Bottom Grating,
2011
California Polytechnic State University - San Luis Obispo
Improvement Of Solar Cell Efficiency Using Nano-Scale Top And Bottom Grating, Xiaomin Jin, Ashton Ellaboudy, Greg Chavoor
Electrical Engineering
We study solar-cell designs using nano-grating on both top (transmission) and bottom (reflection) of the solar cell. First, we perform simulations based on rigorous coupled wave analysis (RCWA) to evaluate the diffraction top gratins. In RCWA method, we calculate up to 20 harmonics, and sweep the launch angle of incident light from 0 to 90 degree. The incident light varies from100nm to 1200nm wavelength. Triangular grating can achieve higher light absorption compared to the rectangular grating. The best top grating is around 200nm grating period, 100nm grating height, and 50% filling factor, which responses to 37% improvement for triangular grating …
Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference,
2011
Missouri University of Science and Technology
Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant
Electrical and Computer Engineering Faculty Research & Creative Works
Two proportionate affine projection sign algorithms (APSAs) are proposed for system identification applications, such as network echo cancellation (NEC), where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristic of l1-norm algorithms, affine projection, and proportionate matrix, the new algorithms are robust to impulsive interferences and colored input and achieve much faster convergence rate in sparse impulse responses than the original APSA, the normalized sign algorithm (NSA), and the proportionate …
Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs,
2011
Missouri University of Science and Technology
Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding
Electrical and Computer Engineering Faculty Research & Creative Works
We study the design optimization of linear precoders that maximize the mutual information in complex-valued vector Gaussian channels under finite alphabet inputs. It is well known that mutual information of a vector channel with discrete constellation source is a highly nonlinear and nonconcave function of the linear precoder matrix G, thereby complicating the precoder design optimization. in this paper, we show that the mutual information is a concave function of W = GhHhHG, where H is the complex-valued channel matrix and superscript "h" represents conjugate transpose. We further propose an iterative algorithm for solving the globally optimal linear precoder G. …
Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems,
2011
Missouri University of Science and Technology
Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy
Electrical and Computer Engineering Faculty Research & Creative Works
For Artificial Neural Networks (ANN) to become more widely used in power systems and the future smart grids, ANN based algorithms must be capable of scaling up as they try to identify and control larger and larger parts of a power system. This paper goes through the process of scaling up an ANN based identifier as it is driven to identify increasingly larger portions of a power system. Distributed and centralized approaches for scaling up are taken and the pros and cons of each are presented. the New England/New York 68-bus power network is used as the test bed for …
Adaptive Critic Design Based Dynamic Optimal Power Flow Controller For A Smart Grid,
2011
Missouri University of Science and Technology
Adaptive Critic Design Based Dynamic Optimal Power Flow Controller For A Smart Grid, Jiaqi Liang, Ronald G. Harley, Ganesh K. Venayagamoorthy
Electrical and Computer Engineering Faculty Research & Creative Works
An adaptive critic design (ACD) based dynamic optimal power flow control (DOPFC) is proposed in this paper as a solution to the smart grid operation in a high short-term uncertainty and variability environment. with the increasing penetration of intermittent renewable generation, power system stability and security need to be ensured dynamically as the system operating condition continuously changes. the proposed DOPFC dynamically tracks the power system optimal operating point by continuously adjusting the steady state set points from the traditional OPF algorithms. the ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal control, where …
Wide Area Monitoring In Power Systems Using Cellular Neural Networks,
2011
Missouri University of Science and Technology
Wide Area Monitoring In Power Systems Using Cellular Neural Networks, Bipul Luitel, Ganesh K. Venayagamoorthy
Electrical and Computer Engineering Faculty Research & Creative Works
The demand of power and the size and complexity of the power system is increasing. Wide area monitoring and control is an integral part in transitioning from the traditional power system to a Smart Grid. However, wide area monitoring becomes challenging as the size of the electric power grid, and consequently the number of components to be monitored, grows. Wide area monitor (WAM) designed using feed-forward and feedback neural network architectures do not scale up to handle the growing complexity of the Smart Grid. in this paper, cellular neural network (CNN) is presented as a way to provide scalability in …
Optimal Location And Sizing Of Energy Storage Modules For A Smart Electric Ship Power System,
2011
Missouri University of Science and Technology
Optimal Location And Sizing Of Energy Storage Modules For A Smart Electric Ship Power System, Chuan Yan, Ganesh K. Venayagamoorthy, Keith Corzine
Electrical and Computer Engineering Faculty Research & Creative Works
The Navy's next generation electric ship's power system will support high energy loads and critical equipment. Energy storage modules will be needed to meet the demands of these loads as well as increase the overall high quality of service. This paper describes an approach to evaluate the impact of energy storage module location and sizing for ship survivability and quality of service. Specifically, a multi-objective optimization algorithm, the multi-objective particle swarm optimization -, is used to obtain Pareto optimal solutions considering survivability, quality of service, and cost. Results based multi-objective particle swarm optimization study show that optimal ESM location and …
Software Development Approach For Discrete Simulators,
2011
University of Nevada, Las Vegas
Software Development Approach For Discrete Simulators, Grzegorz Chmaj, Dawid Maksymilian Zydek
Electrical & Computer Engineering Faculty Research
Simulation is the most common approach to perform the problem research. Among several types of simulation, the most common way is the discrete simulation, which assumes the division of the time scale into fixed length time slots. Depending on investigated problem, simulation packages may be used or it could be necessary to design and create own simulation system. In this paper, we propose the complete pre-study scheme and the most commonly appearing implementation problems with suggested solutions. We also describe how to implement the exemplary simulator in C++.
