Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 170011 - 170040 of 198087

Full-Text Articles in Engineering

Triboelectric Separator With Mixing Chamber And Pre-Separator, John M. Stencel, John L. Schaefer, Heng Ban, James K. Neathery, Tianxiang Li Aug 1999

Triboelectric Separator With Mixing Chamber And Pre-Separator, John M. Stencel, John L. Schaefer, Heng Ban, James K. Neathery, Tianxiang Li

Center for Applied Energy Research Faculty Patents

A triboelectrostatic separation apparatus includes a mixing chamber having opposed first and second charging ports, a separator having a separation chamber, first and second electrodes, and a variable voltage source for applying respective positive and negative voltage potentials to the electrodes. First and second particle streams are delivered through the first and second charging ports resulting in the impingement of the particle streams upon each other within the mixing chamber, thus enhancing the electrostatic charging of the particles contained within the particle streams. The apparatus may also include a pre-separator having a pre-separation chamber, a charged particle collection chamber and …


Emissivity Measurements And Modeling Of Silicon Related Materials, Vijay Krishnamurthy Aug 1999

Emissivity Measurements And Modeling Of Silicon Related Materials, Vijay Krishnamurthy

Theses

The objective of the thesis was to study the radiative properties of silicon related materials for applications in rapid thermal proceesing. In particular, three distinct materials have been considered - Silicon, SIMOX and Tantalum.

The research highlights are Establishment of spectral emissometry as a novel, reliable and reproducible technique for a) Determination of wavelength and temperature dependent reflectivity, transmissivity, emissivity of silicon related materials and structures. The emissometer operates in the wavelength range of 1-20µm and temperature range of 300-1200K. b) Establishment of methodoligies to obtain the frnndemental constants. Effects of wavelength, temperature, total available free carriers by doping types …


Modeling Of A Permeable Reactive Barrier, Guatam C. Ijoor Aug 1999

Modeling Of A Permeable Reactive Barrier, Guatam C. Ijoor

Theses

The focus of the presentstudy was centered on the modeling analysis to support the Permeable Reactive Barrier (PRB) design. The flow model formulated to simulate the Permeable Reactive Barrier System integrated the available geologic, hydro geologic and geo-chemical data from numerous recent installations to simulate a subsurface ground water scenario.

Different generic cases that a PRB system would fall into were identified based on its utility and aquifer conditions and then employed to produce different model adaptations. The different simulation codes and interfaces were evaluated, and the most expedient of them was used to simulate the Model.

The simulations were …


Chemical Volatilization Of Heavy Metals For Waste Separation And Real Time Metals Analysis, Mohammad Nasr Ul-Alam Aug 1999

Chemical Volatilization Of Heavy Metals For Waste Separation And Real Time Metals Analysis, Mohammad Nasr Ul-Alam

Theses

One of the major challenges in environmental analysis concerns the rapid and sensitive detection of metals emitted from combustion stacks. An interesting concept for real time analysis is to convert airborne metal oxide particles in a flow reactor into relatively volatile compounds of a single class, and then analyze in the gas phase. In this project, kinetics of chemical volatilization reaction between Sb2O3 and HCl was investigated. To achieve this a laboratory volatilization flow reactor was built and data was collected for the volatilization reaction in terms of conversion, inlet and outlet concentrations and flow rates. A …


Mutual Interference Investigation Of Cebus And X-10 Powerline Signaling, Sajid Pallithotungal Aug 1999

Mutual Interference Investigation Of Cebus And X-10 Powerline Signaling, Sajid Pallithotungal

Theses

Powerline control signaling using CEBus has great potential towards inexpensive home automation. CEBus transmits at 10 kBps using spread spectrum in the 100-400 kHz band while X-l0 sends 60 Bps using bursts of 120 kHz carrier on the power line. However, these two signals may destructively interfere when present simultaneously. X-10 is narrow band and interferes with the CEBus spread spectrum signal. This thesis looks into the mutual interference patterns of Power Line CEBus communication in the presence of X-l0 module signaling and visa versa. The investigation encompasses a series of tests and measurements on a Power Line CEBus-X10 test …


Characterization Of Steel Corrosion In An Aggressive Environment, Sung Min Maeng Aug 1999

Characterization Of Steel Corrosion In An Aggressive Environment, Sung Min Maeng

Theses

As part of the Sustainable Green Manufacturing Program, the corrosion resistance of sputtered tantalum is being studied in order to evaluate it as a replacement coating for electroplated chrome. To accomplish this, studies were conducted to evaluate corrosion properties of the gun barrel steel by employing corrosion rate and bulk measurements including x-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive x-ray spectroscopy (EDX), and x-ray fluorescence (XRF), as well as synchrotron-based x-ray absorption spectroscopy (XAS).

Corrosion behavior of steel immersed in an aggressive environment of 37.8 % hydrochloric acid at room temperature was investigated as a function of time from …


Interventions Of Water Jet Technology On Skin Surgery, Kittipat Vichyavichien Aug 1999

Interventions Of Water Jet Technology On Skin Surgery, Kittipat Vichyavichien

Theses

The perfect and precise surgical cut, similar to today's laser one, is very important in many surgeries, especially in dissection and to recanaize arterial occlusive lessions. Causing no coagulation is one of the advantages of water jet because it generates no heat. It also provides omni-directional cutting capabilities at very high speeds, resulting edge quality that is usually superior to other existing conventional cutting processes. Debris is always carried away from incisions by jet stream and less damaged tissue, than mechanical incisions. In addition, water jet exerts minimal contact pressure on the tissue being cut due to the small diameter …


Measurements Of The Effects Of Colored Light On The Body, Lynne Hendrickson Aug 1999

Measurements Of The Effects Of Colored Light On The Body, Lynne Hendrickson

Theses

Colored light is used in movies, restaurants, and other situations to create particular environments. It creates a mood and sets a stage for specific events.

This study used colored light to create relaxation and stress in order to evaluate physiological reactions in the human body. In all four studies of this paper, EEG, EKG, and peripheral blood flow were recorded and observed and in the latter two studies peripheral temperature and conductance were also recorded. An audio stressor was introduced in the first three studies to evaluate the stability of the altered mood of the individuals.

Considerable mood alterations were …


Biomechanical Study Of Performance Of A Plugged Femoral Implant Coupled With A Trochanter Cable System Using Finite Element Analysis, Deanna Yvonne Carstarphen Aug 1999

Biomechanical Study Of Performance Of A Plugged Femoral Implant Coupled With A Trochanter Cable System Using Finite Element Analysis, Deanna Yvonne Carstarphen

Theses

A Finite Element Analysis was conducted to determine the effect of a plug on the performance of the critical section of a femoral implant coupled with a trochanter cable grip system. The critical section was defined near the proximal end of the stem where a hole was designed for the purpose of attaching the cable grip system. Two models were generated for the analysis. One consisted of the critical section with the grip cables and a plug filled in the hole and the other was without the plug. The models were based on design specifications provided by Howmedica Incorporated. Two …


Variable Gain Control Of Brushless Dc Motor Control With Low Resolution Sensors, Chung-Hsiang Wang Aug 1999

Variable Gain Control Of Brushless Dc Motor Control With Low Resolution Sensors, Chung-Hsiang Wang

Theses

In this work, feasibility of using low cost, low resolution sensor for high performance brushless dc (BLDC) motor speed control is investigated. Conventional control, using a tachometer or high resolution encoder, suffers from drawbacks such as high cost, large physical volume, and high sensor processing bandwidth. On the other hand, sensorless BLDC motor, appealing in its hardware simplicity, does not provide sufficient fast performance. Using a standard low resolution sensor, such as a hall sensor or commutation encoder, a compromise between cost and performance can be obtained. However, the use of a low resolution sensor does pose a challenge to …


Computer Automated Experimentation For The Control And Assessment Of The Classically Conditioned Eyeblink Response, Michael Terrence Bergen Aug 1999

Computer Automated Experimentation For The Control And Assessment Of The Classically Conditioned Eyeblink Response, Michael Terrence Bergen

Theses

The use of the classically conditioned eyeblink response, a form of associative learning, is a growing method of experimentation in modem science. This type of associative learning, has many features that make it useful for applications in the study of specific neurological functions. The goal of this project was to design and implement a software system for the automated control and on-line evaluation of a classical conditioning experiment for use with human subjects. A program was developed in the LabVIEW programming environment by National Instruments. Basic hardware components produce acoustic signals, deliver airpuffs, and sense and condition physiological responses. Safety …


Study Of The Effects Of Deuterium Implantation Upon The Performance Of Thin-Oxide Cmos Devices, Sumit Kishore Aug 1999

Study Of The Effects Of Deuterium Implantation Upon The Performance Of Thin-Oxide Cmos Devices, Sumit Kishore

Theses

The use of ultra thin oxide films in modem semiconductor devices makes them increasingly susceptible to damage due to the hot carrier damage. Deuterium in place of hydrogen was introduced by ion implantation at the silicon oxide-silicon interface during fabrication to satisfy the dangling bonds. Deuterium was implanted at energies of 15, 25 and 35 keV and at a dose of 1x1014/cm2. Some of the wafers were subjected to N2O annealing following gate oxide growth. It was demonstrated that ion implantation is an effective means of introduction of deuterium. Deuterium implantation brings about a …


Analysis Of Long-Term Heart Rate Variability Using Labview, Daniel Yang Aug 1999

Analysis Of Long-Term Heart Rate Variability Using Labview, Daniel Yang

Theses

Long-term heart rate variability measurement is important in understanding the activities of the autonomic nervous system. Many methods and implications of long-terrn HRV were available in the literature. The first two studies focused on two data analysis techniques that were used on a normal subject. The first study focused on the 1/f fluctuations. For this analysis, three 1 1h heart rate variability data sets were collected with the Polar Vantage NV. A LabVIEW program was used to calculate the power spectrum of the heart rate, and then the 1/f line was calculated by taking the log of the power spectrum …


A New Method For Preparing Self-Assembled Lipid Bilayers On Pt Electrode, Peng Diao, Dian-Lu Jiang, Xiao-Li Cui, Deng-Ping Gu, Ru-Ting Tong Aug 1999

A New Method For Preparing Self-Assembled Lipid Bilayers On Pt Electrode, Peng Diao, Dian-Lu Jiang, Xiao-Li Cui, Deng-Ping Gu, Ru-Ting Tong

Journal of Electrochemistry

A new method for preparing Pt-supported bilayer lipid membrane (Pt-BLM) on Pt electrode cleaned by high power ultrasound was reported. The reported method was convenient, costing less platinum and could be used to form large-area Pt-BLM as compared with the traditional Pt-wire-cutting method. The electrical properties of Pt-BLM were studied using electrochemical impedance spectroscopy and cyclic voltammetry. Experimental results showed that the values of membrane capacitance and the voltammetric characteristics were consistent with those of Pt-BLM prepared by traditional method.


The Ac-Impedance Analysis For Pluse Oxide Film Of Aluminium Alloy, Ai-Ling Du, Xi-Cheng Ma, He-Ming Zhang Aug 1999

The Ac-Impedance Analysis For Pluse Oxide Film Of Aluminium Alloy, Ai-Ling Du, Xi-Cheng Ma, He-Ming Zhang

Journal of Electrochemistry

Bode diagrams for aluminum PC (abbreviated from pulse current) oxide films were first obtained by AC-impedance measurements in a wide range of frequency. The experimental results show that different kinds of electrical equivalent circuits can be used for representing PC films and DC (abbreviated from direct current) oxide films separately, the main differences between them are their porous layers, the PC films are more even with little defects.Those are also verified by SEM and V-I characteristic curve measurements.


Deactivation Of Nickel Oxide/Hydroxide To Electrooxidation Of H2Po2 Anions On Nickel Electrodes In Alkaline Solutions, Tai-Xiang Jiang, Hui-Huang Wu Aug 1999

Deactivation Of Nickel Oxide/Hydroxide To Electrooxidation Of H2Po2 Anions On Nickel Electrodes In Alkaline Solutions, Tai-Xiang Jiang, Hui-Huang Wu

Journal of Electrochemistry

Electrooxidation of hypophosphite anions on polycrystalline nickel in alkaline solutions has been investigated by cyclic voltammetry and open circuit potential measurements. The results are explained based on the mechanism that the first step of hypophosphite oxidation is the adsorption of hypophosphite ions on nickel, followed by the homolysis of its hydrogen bond with the formation of radicals. The oxidation of hypophosphite on nickel in alkaline medium occurs at lower potentials between ca. -0.8 V— -1.1 V (SCE) and phosphite ion is the only oxidation product. There is no indication of hypophosphite oxidation at higher potentials. Severe deactivation of the surface …


Structural And Electrochemical Studies On Lithium Manganese Oxide Containing Li+ Prepared By Hydrothermal Method For Lithium Ion Batteries, De-Yao Liu, Jin-Kua You, Wei Chu, Yong Yang, Zu-Geng Lin Aug 1999

Structural And Electrochemical Studies On Lithium Manganese Oxide Containing Li+ Prepared By Hydrothermal Method For Lithium Ion Batteries, De-Yao Liu, Jin-Kua You, Wei Chu, Yong Yang, Zu-Geng Lin

Journal of Electrochemistry

In this paper, Todorokite manganese oxides containing Li+ with large tunnel structure (sample M5) have been synthesized by hydrothermal methods from natural manganese oxide nano fiber (sample M4). The structure and composition of the samples were characterized and analyzed by XRD, ICP, TGA and DTA. Its electrochemical behavior as a cathode materials for rechargeable lithium ion insertion were studied by galvanostatic charge/discharge measurements. XRD results show that the sample M4 is mainly composed of Birnessite and Vernadite structure. Although the sample M4 shows a high initial capacity of approximately 150 mAh/g, its performances decrease gradually over 30 cycles. It …


Calculation Of Corrosion Rate Of Passive Metals With Charge Curve Analysis Technique, Yuan-Sheng Zhang, Min Gong Aug 1999

Calculation Of Corrosion Rate Of Passive Metals With Charge Curve Analysis Technique, Yuan-Sheng Zhang, Min Gong

Journal of Electrochemistry

This work contains two parts: (1) A charge curve equation having no appro-ximation for passivated metal corrosion systems is derived and compared with the routine charge curve equation, which is virtual only when the polarization is minim(linear range). (2) It is simpler to analyze charge curve data by from of charge differential equation than from charge curve equation. After the charge curve data are measured, the slope of charge curve is computed by numerical differentiation method, then the charge differential equation may be transformed to a set of linear equations using polynomial approximation. The electrochemical parameters of corrosion system would …


Direct Electrolysis Of Seawater On Conducting Film For Microbial Anticorrosion 1. Simulation And Measurement Technique, Wei-Ling Hu, Ling-Ling Wu, Jing Zhou, Jing-Xin Li, Jin Luo, Zhong-Hua Lin Aug 1999

Direct Electrolysis Of Seawater On Conducting Film For Microbial Anticorrosion 1. Simulation And Measurement Technique, Wei-Ling Hu, Ling-Ling Wu, Jing Zhou, Jing-Xin Li, Jin Luo, Zhong-Hua Lin

Journal of Electrochemistry

Based on the electrochemical micro probe and the weak signal detection technique, simulated test and measurement system were set up by the use of four-electrode cell(including a micro electrode), bipotentiostat, lock-in amplifier and three-dimensional micro manipulating device. Based on the system, the micrometer scale concentration distribution of trace hypochlorite, which is produced by direct electrolysis of seawater on the conducting film for preventing microbial corrosion has been obtained for the first time. Both relationships between concentration of hypochlorite and its reduction current, which is termed an working curve, and between the reduction current of hypochlorite and measured time are reported.


The Techniques Of The Paired Electrosynthesis, Hong-Kun Zhang, Deng-Ping Gu Aug 1999

The Techniques Of The Paired Electrosynthesis, Hong-Kun Zhang, Deng-Ping Gu

Journal of Electrochemistry

In this Paper, we introduce our work on paired electrosynthesis. In conjunction with our research practice, we introduce electrolytic conditions,such as material of electrode ,courrent density and electrolytic temperature etc,as reference for researcher. We categorize the paired electrosynthesis techniques to widen our view on the paired electroorganic synthesis and to promote the deveopments of paired electrosynthesis techniques.


A Study Of The Corrosion On Bronze, Hong-Fan Zhu, Hao Zhou Aug 1999

A Study Of The Corrosion On Bronze, Hong-Fan Zhu, Hao Zhou

Journal of Electrochemistry

The bronze is the treasure in chinese metallic antique, which was typified by product in Shang-Zhou period (three thousands years ago). Because of corrosion, archaeological messages, such as inscription and pattern on the surface of bronze, would be damaged then the value of bronze antique decreased. The bronze disease is a common disease which forms powdery rust on the surface of bronze in atmospheric environment, the powdery rust emerge from under incrusted rust, then spreads, and eventually leads to bronze damaged. This paper investigates the bronze disease. According to the chemical and electrochemical tests in simulated occluded cell, the variation …


Influence Of Thiourea And Its Derivate On The Process Of Cathodic Electrodeposition Of Copper, Yun-Hui Dong, Ai-Hong Zou, Yun-Xia Zhao Aug 1999

Influence Of Thiourea And Its Derivate On The Process Of Cathodic Electrodeposition Of Copper, Yun-Hui Dong, Ai-Hong Zou, Yun-Xia Zhao

Journal of Electrochemistry

The effects of thiourea and its derivate on the electrodeposition of copper from the dilute acid sulphate solutions have been studied by using potential sweep techniques at quasisteady state. Limiting current densities (Id), exchange current densities (i0) and αn are obtained by data processing with the least square method. Thiourea has a depolarizing effect on the copper depositing at concentrations below 8 mg·L-1, and a polarizing effect at higher concentration (>10 mg·L-1), and it changes the mechanism of copper deposition reaction. Propenyltiourea and Phenylthiourea have a depolarizing effect on the …


Study On Synthesizing Of 2-Methylbutanoic Acid By Indirect Electrooxidation, Chong-Tao Zhao, Ze-Shan Zhu Aug 1999

Study On Synthesizing Of 2-Methylbutanoic Acid By Indirect Electrooxidation, Chong-Tao Zhao, Ze-Shan Zhu

Journal of Electrochemistry

The working conditions of synthesizing 2-methylbutanoic acid by oxidizing 2-methyl-1-butanol with tetrabutylammonium hydrosulfate (TBAS) or tetrabutylammonium perchlorate (TBAP) as phase transfer catalyst in sulfuric acid Cr(Ⅵ) oxidation medium was studied. The Cr(Ⅵ) oxidation medium could be electrolytic regenerated from Cr(Ⅲ), during above oxidation reaction. Under the optinum condition, the yield of 2-methylbutanoic acid is more than 95%.


Electrochemical Synthesis Of Fes Electrode And Its Behavior Measurement, Cong-Sheng Guan Aug 1999

Electrochemical Synthesis Of Fes Electrode And Its Behavior Measurement, Cong-Sheng Guan

Journal of Electrochemistry

The Potential for the electrochemical synthesis of FeS electrode has been obtained by cyclic voltammetry. FeS electrodes were synthesiaed by controlling Fe electrode at -1.0 V in LiCl-KCl-Li2S and Li(FClI)-Li2S melts and their behavior were measured also. The FeS electrode synthesized in molten Li(FClI)-Li2S has the best charge and discharge properties.


The Effects Of Metallic Cobalt Abbition On The Performance Of Pasted Nickel Electrodes, An-Bao Yuan, Jian-Qing Zhang, Wan-Chun Ding, Shao-An Cheng, Chu-Nan Cao Aug 1999

The Effects Of Metallic Cobalt Abbition On The Performance Of Pasted Nickel Electrodes, An-Bao Yuan, Jian-Qing Zhang, Wan-Chun Ding, Shao-An Cheng, Chu-Nan Cao

Journal of Electrochemistry

The Ni-foam pasted nickel electrodes prepared by coprecipitated Ni1-XZnX(OH)2 with and without cobalt power addition have been studied. The electrode with addition of metallic cobalt showed a higher performance both in discharge capacity and cycle life. It is known from the experiment results that the addition of Co can remarkably increase the active material utilization which is suggested to be improvement of discharge depth due to the conducting CoOOH formed in the first activation charging. The superior capacity during cycling could be attributed to the synergistic action of zinc and cobalt addition ,especially to the …


In Situ Ftirs Studies Of The Electrochemically Induced Coupling Of Osmium Nitrido Species In Acetonitrile, Sheng-Pei Chen, Shi-Gang Sun Aug 1999

In Situ Ftirs Studies Of The Electrochemically Induced Coupling Of Osmium Nitrido Species In Acetonitrile, Sheng-Pei Chen, Shi-Gang Sun

Journal of Electrochemistry

/


Preparation And Ionic Conductivity Of Nanometer-Sized Li2+XGdXSi1+XO3 By The Sol-Gel Method, Ru-Fen Chen, Xiu-Qin Song, Hua-Ting Liu Aug 1999

Preparation And Ionic Conductivity Of Nanometer-Sized Li2+XGdXSi1+XO3 By The Sol-Gel Method, Ru-Fen Chen, Xiu-Qin Song, Hua-Ting Liu

Journal of Electrochemistry

Li2+xGdxSi1-xO3(x =0~0.15) samples have been prepared by the Sol-Gel method. The power samples were characterized by DTA-TG, XRD and TEM. Ionic conductivity of the sinter was determined by means of A-C impedance measurements. The experimental results showed that the range of solid-solution was 0 < x ≤ 0.09, while the conductivity of samples raised with increasing amount of Gd2O3 added, and average grain size of samples was 80 nm. In comparing with the samples by the conventional solid state reaction, the samples prepared by Sol-Gel method required lower temperature and presented higher ionic conductivity.


A Study Self-Passivation Of Passivie Film Of Stainless Steel In Vinylon Aldehyde Solution, Si-Fu Hu, Chuan-Bi Xu, Zhu-Qiu Cheng Aug 1999

A Study Self-Passivation Of Passivie Film Of Stainless Steel In Vinylon Aldehyde Solution, Si-Fu Hu, Chuan-Bi Xu, Zhu-Qiu Cheng

Journal of Electrochemistry

Properties of self-passivation for the anodic passive film of 1Cr18Ni9Ti and the firsthand passive film of SUS 36 stainless steel in vinylon aldehyde solution(H2SO4(240 g/L)+Na2SO4(70 g/L)+HCHO(25 g/L)+[Fe3+](35.4 mg/L)+[Cl-](240 mg/L) at 70 ℃ were studied by galvanostatic and potentiostatic polarization mesurements. The effects of compponents of vinylon aldehyde solution, i.e. Fe3+ and Cl-, on the passivation behaviours of stainless steel have also been investigated. The experimental results showed there is a conversion zone of the active/passive state if the area ratio of active/passive state on these …


When Bad Leads To Good: Airplane Crashes And The Political Psychology Of Stress, Ibpp Editor Aug 1999

When Bad Leads To Good: Airplane Crashes And The Political Psychology Of Stress, Ibpp Editor

International Bulletin of Political Psychology

This article begins a series on research presented at the 1999 Annual Convention of the American Psychological Association. The article suggests some of the complexities in the construct of stress and applies them to research on the psychological aftermath of surviving an airplane crash.


An Assessment Of Renewable Energy Options At Brooks Camp, Katmai National Park And Preserve, Florida Solar Energy Center, Gerard Ventre Aug 1999

An Assessment Of Renewable Energy Options At Brooks Camp, Katmai National Park And Preserve, Florida Solar Energy Center, Gerard Ventre

FSEC Energy Research Center®

At the request of Brad Richie, NPS Alaska Support Office and manager of the Brooks Camp relocation project, a renewable energy team (RET) from the Department of Energy/Federal Energy Management Program (DOE/FEMP) conducted an on-site power system assessment at Brooks Camp. The assessment included:

  • An evaluation of the current electrical loads at the site,
  • An evaluation of the current facility power system,
  • A review of the plans for the relocated facility and planned power needs,
  • An assessment of the renewable resources and possible siting options, and
  • The identification of potential opportunities for renewable power systems.

The RET activities were coordinated …