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2007

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Articles 2131 - 2160 of 3831

Full-Text Articles in Engineering

Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai Feb 2007

Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai

Journal of Electrochemistry

The effects of direct current(DC) bias voltage on the structure of lipid membranes forming on a glassy carbon electrode(GCE) was investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).The experiment showed that the lipid membranes can be formed with either positive or negative bias potential exerted.When bias voltage was exerted,bilayer lipid membranes tended to form due to the electrostatic interaction between the superficial positive charges on the polarized electrode and the negative charged part of PC.When the positive bias voltage overrun the range,the lacunas on s-BLMs would increase,and the BLMs would be broken.A proper equivalent circuit was nonlinearly fitted,based on the …

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Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi Feb 2007

Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi

Journal of Electrochemistry

An experimental setup with two external saturated calomel reference electrodes(SCE)and two flow cells was established for flow battery research application.By using this setup,the cell voltage,potentials and open circuit potentials of the positive and negative electrodes for a lab-scale flow battery single cell,could be determined simultaneously during charge-discharge(C-D) cycle test.Then,the ohmic internal resistance drop(iR drop),overpotentials at the negative and positive electrodes of the cell during C-D process,were calculated.The average iR drop accounts for about 74% of the total voltage losses during the C-D cycle at current density of 60 mA·cm-2,suggesting the voltage efficiency(VE) of vanadium redox-flow battery(VRB) single cell …

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Composite Electroplating And Characterizations Of Sn-Sba15 Anode For Lithium-Ion Batteries, Xiao-Yong Fan, Jin-Mei Xu, Quan-Chao Zhuang, Hong-Hong Jiang, Ling Huang, Yan-Xia Jiang, Quan-Feng Dong, Shi-Gang Sun Feb 2007

Composite Electroplating And Characterizations Of Sn-Sba15 Anode For Lithium-Ion Batteries, Xiao-Yong Fan, Jin-Mei Xu, Quan-Chao Zhuang, Hong-Hong Jiang, Ling Huang, Yan-Xia Jiang, Quan-Feng Dong, Shi-Gang Sun

Journal of Electrochemistry

Sn-SBA15 anode was prepared by composite electroplating. The first discharge and charge capacity was 1075mAh/g and 630mAh/g respectively. After fifty charge/discharge cycles, the charge and discharge capacity of Sn-SBA15 were retained above 400mAh/g. XRD patterns indicated that the Sn-SBA15 has tetragonal crystal type. SEM images showed that the Sn-SBA15 had a honeycombed surface. EIS results indicated that there was SEI film formed on the surface of Sn-SBA15 electrode.

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Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu Feb 2007

Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu

Journal of Electrochemistry

The electrodes in both Li/SOCl2 cells and BCX cells were studied by ac impedance spectroscopy.The results indicate that the resistance of the electrode passive layer increased with the storage time,then became stabilized in both kinds of cells.But the electrode resistance decreased a lot after adding BrCl into the cells.The resistance of the Li electrode decreased about a half to that without BrCl,and the value of the glassy carbon electrode decreased from about 100 kΩ to 2 kΩ.The huge resistance of the glassy carbon electrode indicates that it is the control electrode of the cell.

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Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang Feb 2007

Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang

Journal of Electrochemistry

The electrochemical activity of multi-walled carbon nanotubes(MWNTs) with different sizes,including four different MWNTs with the same length and different diameter,two different MWNTs with the same diameter and different length has been assessed and compared.The various MWNTs modified electrodes were prepared by immobilizing the suitable amount of MWNTs onto a glassy carbon electrode,and their voltammetric responses to ferricyanide,uric acid and dopamine were examined.The corresponding cyclic voltammetric data was showed that the electrochemical and electrocatalytic activities are depended on the nanotube length.The electrochemical reactivity of short MWNT(S-MWNT) is better than that of long MWNT(L-MWNT),which may be mainly attributed to the existence of …

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Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang Feb 2007

Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang

Journal of Electrochemistry

A MWNTs modified GC electrode was constructed successfully to be used to detect hydrogen peroxide.Two methods of maximum anodic current of cyclic voltommogram and chronoamperometry were adopted to measure the concentration of hydrogen peroxide.The results show that the MWCNTs can enlarge the effective surface area of GC electrode and can enormously enhance the electron transfer.The sensitivity and correlation coefficient for hydrogen peroxide detection are 2.84 μA/mmol·L-1,0.997 and 1.5 μA/mmol·L-1,0.971 for cyclic voltammetry and chronoamperometry,respectively.The procedure of the two methods to detect hydrogen peroxide is simple,and the results obtained are satisfied.

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Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun Feb 2007

Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun

Journal of Electrochemistry

Influence of electrolyte on the electrocatalytic properties of Pt/GC electrodes for formic acid oxidation were studied by using cyclic voltammetry, SEM and electrochemical in situ FTIR spectroscopy. It has demonstrated that the surfaces of Pt/GC electrodes prepared in H2SO4 (Pt/GC1) or in HClO4(Pt/GC2) are all composed of platinum particles, but which crystals are some differences in size and shape.Diameters of platinum particles on the surface Pt/GC1 are of 100~200 nm, and with spheral shape in the majority. The sizes of platinum particles on the Pt/GC2 electrode are larger in general,part of particles is of cube …

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Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu Feb 2007

Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu

Journal of Electrochemistry

For the electrochemical machining of titanium alloys,a passivating film tends to form on the machining surface,which holdbacks the process of machining;and some corrosive pittings can appear on the non-machining surface,which leading to the poor surface quality.So how to improve the machining surface quality,this is a hot problem in aerospace industries.An experiment plan has been made with the method of uniform design and the variance analysis has been carried out using the result data of the previous experiments.The experimental results show that an excellent machining surface with Ra 0.38 μm would be obtained in the electrolyte of 10% NaCl solution,4% Na …

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Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang Feb 2007

Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang

Journal of Electrochemistry

Polymethyl methacrylate(PMMA) based gel polymer electrolytes electrochemical double layer capacitors(GPE-EDLCs) were fabricated by an in situ polymerisatonal method with actived carbon electrodes,using propylene carbonate(PC) and ethylene carbonate(EC) as plasticizer,lithion perchlorate as surporting electrolytes.The ion conductivity values of GPEs were evaluated by AC impedance.The properties of PMMA-based GPEs capacitors were researched by impedance spectrum,cyclic voltammetry,galvanostatic charge-discharge.It showed that the ion conductivities of the PMMA-based gel polymer electrolytes reached to 3.7 mS·cm-1 at ambient tempreture.The working voltage of the capacitors reached to 3.0 V.The specific capacitance of the capacitor was obtained as high as 41.6 F·g-1(I=1 mA·cm-2).The …

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Electrochemical Characteristics Of La0.7-XCeXMg0.3Ni2.4Co0.6(X=0～0.4) Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan Feb 2007

Electrochemical Characteristics Of La0.7-XCeXMg0.3Ni2.4Co0.6(X=0～0.4) Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The effect of partial substitution of Ce for La on the structure and the electrochemical properties of the La0.7-xCexMg0.3Ni2.4Co0.6(x=0～0.4)hydrogen storage alloys have been investigated systematically.The result of X-ray powder diffraction(XRD) show that the alloys are all consisted of the LaNi3 phase and the LaNi5 phase.The maximum discharge capacity is decreased gradually with increase of the Ce contents,but the cycling life is improved obviously.

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Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd0.2Ce0.8O2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen Feb 2007

Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd0.2Ce0.8O2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen

Journal of Electrochemistry

A Ni-scandia-stabilized zirconia(Ni-ScSZ) cermet anode modified by coating with nano-sized gadolinium-doped ceria(GDC,Gd0.2Ce0.8O2) was prepared using a simple combustion process for the solid oxide fuel cell(SOFC) running on methane fuel. X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated that the surface of Ni-ScSZ was coated by nano-sized GDC particles(<100nm). Single cell testing showed that the 2.0%(by mass) GDC-coated Ni-ScSZ anode had better performance. The highest power densities of the cell with this anode were 825 and 848mW/cm2 at 850℃ in humidified hydrogen and methane, respectively, whereas the corresponding values were 584 and 586mW/cm2 for the cell with Ni-ScSZ anode.Electrochemical impedance spectra(EIS) illustrated that the cell with Ni-ScSZ anode exhibited far greater impedances than the cell with 2.0%(by mass) GDC-coated Ni-ScSZ anode.Then the …

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Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai Feb 2007

Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai

Journal of Electrochemistry

The Ru-Ir /Ti electrode as cathode to electrolysis the synthetic phenolic wastewater was studied. The effect of the initial chloride concentration on the electrolytic treatment result has been discussed. Experiment result shows that the electrochemical oxidation of phenol suits to one kinetics equation in given electrolytic time. If the initial chloride concentration in wastewater increases, the time of the electrochemical oxidation of phenol can be shorten, in other words the apparent rate constant is greater. The middle matters of electrochemical oxidation of phenol in the chloride system detected out by HPLC and GC-MS is mainly 1-chloro-phenol, 4-chloro-phenol, 2,4-dichloro-phenol, 2,6-dichloro-phenol, 2,4,6-trichloro-phenol, …

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Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou Feb 2007

Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou

Journal of Electrochemistry

Diamond-like carbon (DLC) films were deposited on stainless steel substrates at atmospheric pressure and low temperature (60 ℃) by electrolysis in a methanol solution with a pulseddirect current power supply. The morphology and microstructure of the resulting DLC films were analyzed using atomic force microscopy(AFM), scanning electron microscopy (SEM), Raman spectroscopy and Fourier transformation infrared spectrometry (FTIR). The experimental results show that the hydrogenated diamond-like carbon filmsare smooth and compact. Raman spectroscopy analysis confirmed the presence of a strongpeak at 1332.51 cm-1, which is assigned to crystalline diamond. The deposition rate can be enhanced to 0.5 μm/h by …

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Modified Luciferase, Eileen H. Kim Choi, David R. Shonnard, Irina V. Rybina Feb 2007

Modified Luciferase, Eileen H. Kim Choi, David R. Shonnard, Irina V. Rybina

Michigan Tech Patents

The invention comprises modified luciferase proteins which are more resistant to inhibition by test chemicals than wild type luciferase. The modified luciferases also contain greater thermostability than wild type luciferase.

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Reducing Power In Fpga Designs Through Glitch Reduction, Nathaniel Hatley Rollins Feb 2007

Reducing Power In Fpga Designs Through Glitch Reduction, Nathaniel Hatley Rollins

Theses and Dissertations

While FPGAs provide flexibility for performing high performance DSP functions, they consume a significant amount of power. Often, a large portion of the dynamic power is wasted on unproductive signal glitches. Reducing glitching reduces dynamic energy consumption. In this study, retiming is used to reduce the unproductive energy wasted in signal glitches. Retiming can reduce energy by up to 92%. Evaluating energy consumption is an important part of energy reduction. In this work, an activity rate-based power estimation tool is introduced to provide FPGA architecture independent energy estimations at the gate level. This tool can accurately estimate power consumption to …

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Ghz Serial Passive Clock Distribution In Vlsi Using Bidirectional Signaling, Vladimir I. Prodanov, Mihai Banu Feb 2007

Ghz Serial Passive Clock Distribution In Vlsi Using Bidirectional Signaling, Vladimir I. Prodanov, Mihai Banu

Electrical Engineering

We introduce a serial passive clock distribution technique allowing efficient and accurate skew removal at any arbitrary clock drop point. The passive transmission medium may be on-chip electrical transmission lines built in current IC technology or possible optical wave-guides in future developments. The proposed technique is naturally insensitive to practical loses and other non ideal effects and has the capability of covering large chip areas.

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Novel Layered Scalable Video Coding Transmission Over Mimo Wireless Systems With Partial Csi And Adaptive Channel Selection, Daewon Song, Chang Wen Chen Feb 2007

Novel Layered Scalable Video Coding Transmission Over Mimo Wireless Systems With Partial Csi And Adaptive Channel Selection, Daewon Song, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

In this paper, we present a novel layered scalable video transmission scheme over multi-input multi-output (MIMO) wireless systems. The proposed layered scalable video transmission scheme is able to adaptively select the MIMO sub-channels for prioritized delivery of layered video signals based on only estimated partial channel state information (CSI). This scheme is fundamentally different from open loop (OL)-MIMO systems such as V-BLAST in which the CSI is only available at the receiver side. Without CSI at the transmitter, data sequences in OL-MIMO are transmitted simultaneously with equal power via multiple antennas. Therefore, OL-MIMO systems are not appropriate for transmitting compressed …

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Super Barrier Rectifier - A New Generation Of Power Diode, V. Rodov, A. L. Ankoudinov, Taufik Feb 2007

Super Barrier Rectifier - A New Generation Of Power Diode, V. Rodov, A. L. Ankoudinov, Taufik

Electrical Engineering

The main principle behind the new Super Barrier Rectifier (SBR) approach is to create the "Super" barrier for majority carriers without unreliable metal-semiconductor Schottky contact. SBR technology creates such barrier in the MOS channel. The height of this barrier can be easily adjusted by the doping concentration in the channel. This paper demonstrates that the new power diodes combine high performance and high reliability for low voltage applications (below 100V). The underlying concepts and analysis of operation are presented as well as the lab test results that compare performance and reliability between Schottky and the new SBR diode.

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A Compositional Approach To Asynchronous Design Verification With Automated State Space Reduction, Jared Ahrens Feb 2007

A Compositional Approach To Asynchronous Design Verification With Automated State Space Reduction, Jared Ahrens

USF Tampa Graduate Theses and Dissertations

Model checking is the most effective means of verifying the correctness of asynchronous designs, and state space exploration is central to model checking. Although model checking can achieve very high verification coverage, the high degree of concurrency in asynchronous designs often leads to state explosion during state space exploration. To inhibit this explosion, our approach builds on the ideas of compositional verification. In our approach, a design modeled in a high level description is partitioned into a set of parallel components. Before state space exploration, each component is paired with an over-approximated environment to decouple it from the rest of …

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A Coarse Grain Model For Dna, Thomas A. Knotts, Nitin Rathore, David C. Schwartz, Juan J. De Pablo Feb 2007

A Coarse Grain Model For Dna, Thomas A. Knotts, Nitin Rathore, David C. Schwartz, Juan J. De Pablo

Faculty Publications

Understanding the behavior of DNA at the molecular level is of considerable fundamental and engineering importance. While adequate representations of DNA exist at the atomic and continuum level, there is a relative lack of models capable of describing the behavior of DNA at mesoscopic length scales. We present a mesoscale model of DNA that reduces the complexity of a nucleotide to three interactions sites, one each for the phosphate, sugar, and base, thereby rendering the investigation of DNA up to a few microns in length computationally tractable. The charges on these sites are considered explicitly. The model is parametrized using …

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Black Rock Planet: The Next Two Challenges, Robert J. Twiggs Feb 2007

Black Rock Planet: The Next Two Challenges, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Black Rock Planet: The Next Two Challenges" from February 22, 2007.

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Accurate Target Geolocation And Vision-Based Landing With Application To Search And Engage Missions For Miniature Air Vehicles, Duncan B. Barber Feb 2007

Accurate Target Geolocation And Vision-Based Landing With Application To Search And Engage Missions For Miniature Air Vehicles, Duncan B. Barber

Theses and Dissertations

Miniature air vehicles (MAVs) have attracted a large amount of interest recently both from the research community and from the public. New battery technologies as well as rapid developments in embedded processing and MEMS sensor technologies have greatly increased the potential of these vehicles. MAVs have been envisioned playing significant roles in both civil and military applications. Examples include: fire monitoring, search and rescue, traffic monitoring, crop monitoring, convoy protection, border surveillance, troop support, law enforcement, natural disaster relief, and aerial photography. The application of MAVs tends to center on the ability of the MAV to collect and deliver visual …

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Selective Assembly Of Nanoparticles On Block Copolymer By Surface Modification, Sanjun Niu, Ravi F. Saraf Feb 2007

Selective Assembly Of Nanoparticles On Block Copolymer By Surface Modification, Sanjun Niu, Ravi F. Saraf

Ravi Saraf Publications

We have developed a method to selectively deposit nanoparticles on the ordered nanoscale elements of PS–PI–PS (polystyrene– polyisoprene–polystyrene) block copolymer film. The process utilizes reactive ion plasma to selectively modify the PS surface with amine groups to electrostatically attract negatively charged Au nanoparticles. In spite of the strong interparticle Coulombic repulsion, the deposition on PS domains is significantly high. It is observed that the deposition at the edges of the domain is particularly high, forming a percolating nanoparticle necklace. The latter may lead to interesting avenues to fabricate electronic devices.

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Synthesis Of Gold Micro- And Nano-Wires By Infiltration And Thermolysis, E.A. Olevsky, X. Wang, E. Bruce, M.B. Stern, S. Wildhack, F. Aldinger Feb 2007

Synthesis Of Gold Micro- And Nano-Wires By Infiltration And Thermolysis, E.A. Olevsky, X. Wang, E. Bruce, M.B. Stern, S. Wildhack, F. Aldinger

Industrial and Manufacturing Engineering

An approach for synthesizing micro- and nano-sized gold wires by infiltration and thermolysis is investigated. A porous ZrO2 ceramic preform with aligned pores obtained by unidirectional freezing and freeze-drying is employed as an infiltration template. The sintered porous ZrO2 preform is then infiltrated by a brushing gold solution. The thermolysis is conducted at 600 °C in air. Micro- and nano-sized gold wires are developed within the walls of the pores after thermolysis. The diameter of the gold wires ranges from several hundred nanometers to several microns.

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Monte Carlo Simulation Of Scanning Electron Microscopy Bright Contrast Images Of Suspended Carbon Nanofibers, Makoto Suzuki, Toshishige Yamada, Cary Y. Yang Feb 2007

Monte Carlo Simulation Of Scanning Electron Microscopy Bright Contrast Images Of Suspended Carbon Nanofibers, Makoto Suzuki, Toshishige Yamada, Cary Y. Yang

Electrical and Computer Engineering

The authors present a Monte Carlo study of previously observed bright contrast from carbon nanofibers suspended over the underlying substrate using scanning electron microscopy (SEM). The analysis shows that the origin of the bright contrast is mainly the increase in the secondary electron signal from the substrate when a gap between the nanofiber and substrate exists. The SEM signal dependence on the gap height is well reproduced by Monte Carlo simulation as well as a derived analytical expression. The bright contrast prevails when the SEM beam size is much smaller than the nanofiber diameter.

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Investigation Of Coupled Lateral And Torsional Vibrations Of A Cracked Rotor Under Radial Load, Xi Mu, Jim Meagher, Clinton Judd Feb 2007

Investigation Of Coupled Lateral And Torsional Vibrations Of A Cracked Rotor Under Radial Load, Xi Mu, Jim Meagher, Clinton Judd

Mechanical Engineering

A practical cracked rotor model with two disks representing a turbine and generator is studied using a four degree of freedom model; two transverse displacements and two torsional angular displacements. The differential equations of a rotor with a crack, unbalance, and constant radial force are first derived in detail using energy principles. The nonlinearities related with a “breathing” crack are incorporated, which distinguishes this paper from others studying stiffness anisotropy of a rotor with a similar rotor configuration. Through numerical simulations, this paper demonstrates the lateral-torsional coupling that occurs with a shaft crack and predicts torsional critical speed frequencies at …

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Response Of A Warped Flexible Rotor With A Fluid Bearing, Jim Meagher, Xi Wu, Chris Lencioni Feb 2007

Response Of A Warped Flexible Rotor With A Fluid Bearing, Jim Meagher, Xi Wu, Chris Lencioni

Mechanical Engineering

A two complex degrees of freedom model is developed and compared to experimental data for various amounts of rotor bow and its orientation to mass imbalance of the rotor. The equation of motion is developed by adding constant forces that rotate with the rotor to a Bently-Muszynska two-mode isotropic rotor model with a plane journal bearing. Diagnostic information discernable from probes at the bearing is emphasized and compared to midspan response where previous research has concentrated. Good agreement between the analytical model and experiment demonstrate that the analysis presented can be useful to diagnose and balance residual shaft bow from …

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Estimating The Probability Of Failure And Associated Risk Of The California Bay Delta Levee System, Robb E.S. Moss, J. Michael Eller Feb 2007

Estimating The Probability Of Failure And Associated Risk Of The California Bay Delta Levee System, Robb E.S. Moss, J. Michael Eller

Civil and Environmental Engineering

Recent events in New Orleans have shown the magnitude of life loss and property damage that can occur due to the failure of man-made levees. The California Bay Delta and Sacramento levee systems in California pose a similar or greater level of risk to life and property. In order to effectively mitigate the hazard associated with levee failure a systematic evaluation of risk must be carried out. This paper presents preliminary research into the risk associated with the California Bay Delta. A comprehensive list of failure modes for man-made levees is presented. Preliminary empirical data on the temporal frequency of …

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The Relationship Between The Location Of Obstacle And Indoor Particle Deposition, Je-Ee Ho, Hong T. Young Feb 2007

The Relationship Between The Location Of Obstacle And Indoor Particle Deposition, Je-Ee Ho, Hong T. Young

Journal of Marine Science and Technology–Taiwan

An appropriate ventilation system design not only increases the indoor ventilation effect but effectively improves the particle concentration distribution. The locations of indoor furniture are used to analyze the indoor airflow and particle distribution by numerical skill in this study. Also, a 45 cm × 45 cm × 45 cm chamber is setup as experiment apparatus which is made by acrylic resin board with 16 holes connected to supply air flow. In order to simulate the furniture effect, some wooden blocks are located at the chamber. The temperature and humidity sensors are connected to the data acquisition system with a …

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Spherical Silicon-Shell Photonic Band Gap Structures Fabricated By Laser-Assisted Chemical Vapor Deposition, H. Wang, Z. Y. Yang, Yongfeng Lu Feb 2007

Spherical Silicon-Shell Photonic Band Gap Structures Fabricated By Laser-Assisted Chemical Vapor Deposition, H. Wang, Z. Y. Yang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Laser-assisted chemical vapor deposition was applied in fabricating three-dimensional (3D) spherical-shell photonic band gap (PBG) structures by depositing silicon shells covering silica particles, which had been self-assembled into 3D colloidal crystals. The colloidal crystals of self-assembled silica particles were formed on silicon substrates using the isothermal heating evaporation approach. A continuous wave Nd:YAG laser (1064 nm wavelength) was used to deposit silicon shells by thermally decomposing disilane gas. Periodic silicon-shell/silica-particle PBG structures were obtained. By removing the silica particles enclosed in the silicon shells using hydrofluoric acid, hollow spherical silicon-shell arrays were produced. This technique is capable of fabricating structures …

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