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2001

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Articles 1171 - 1200 of 1795

Full-Text Articles in Engineering

Differences In Civil Engineer Perceptions Of Change Based On Prior Training And Experience, Steven W. Lo Mar 2001

Differences In Civil Engineer Perceptions Of Change Based On Prior Training And Experience, Steven W. Lo

Theses and Dissertations

The Department of Defense (DoD) and the United States Air Force (USAF) have moved toward an aggressive stance to competitively source and privatize (CS&P) support functions as much as possible. This move is intended to shrink support costs and redirect the savings to force and equipment modernization. In addition, the USAF hopes to realize improved services, gain access to technology, share risks with contractors, and allow its forces to focus on the core competencies. In order to implement OS&P, the USAF communicates information through two major pathways, passive and active. Passive communication is similar to traditional classroom learning where information …

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A Methodology For Simulating The Joint Strike Fighter's Prognostics And Health Management System, Michael E. Malley Mar 2001

A Methodology For Simulating The Joint Strike Fighter's Prognostics And Health Management System, Michael E. Malley

Theses and Dissertations

The Autonomic Logistics System Simulation (ALSim) model was developed to provide decision makers a tool to make informed decisions regarding the Joint Strike Fighter's (JSF) Autonomic Logistics System (ALS). The ALS provides real-time maintenance information to ground maintenance crews, supply depots, and air planners to efficiently manage the availability of JSF aircraft. This thesis effort focuses on developing a methodology to model the Prognostics and Health Management (PHM) component of ALS. The PHM component of JSF monitors the aircraft status. To develop a PHM methodology to use in ALSim a neural network approach is used. Notional JSF prognostic signals were …

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Forecasting Readiness: Using Regression To Predict The Mission Capability Of Air Force F-16 Fighter Aircraft, Steven A. Oliver Mar 2001

Forecasting Readiness: Using Regression To Predict The Mission Capability Of Air Force F-16 Fighter Aircraft, Steven A. Oliver

Theses and Dissertations

According to many, the readiness of America's forces deteriorated in the 1990s. In the Air Force, the combat readiness of its fighter aircraft has declined. One of its indicators of combat readiness, the mission capable rate, is used to identify the percentage of aircraft unable to perform their missions. From FY94-FY98, the aggregate total not mission capable rate for maintenance steadily increased from 14% to 18.2% while total not mission capable rate for supply increased from 5.5% to 17.5% between FY86 and FY00. The USAF uses the funding/Availability Multi-Method Allocator for Spares model to forecast these rates for its aircraft. …

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Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker Mar 2001

Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker

Theses and Dissertations

Subsurface contamination by industrial chemicals is one of the most prevalent and costly environmental problems facing the United States government. This contamination problem must be managed to protect human health and the environment. Two basic strategies are used to deal with subsurface contamination: source removal and contaminant containment. While much cost and performance data are available for individual technologies associated with each of these strategies, there have been very few studies that have examined the benefits of implementing source removal technologies in order to reduce contaminant containment (and hopefully total) costs. This study examines the tradeoff between extent of source …

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Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts Mar 2001

Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts

Theses and Dissertations

The purpose of this study is to gain understanding of the dynamics of the processes that degrade Perchloroethene (PCE) to ethene, within the confines of the methanogenic zone of a constructed wetland. A system dynamics modeling approach is used. This model is focused on determining conditions that will enhance contaminant degradation. The chemical and biological processes within the methanogenic zone of a wetland system are extremely complex and dynamic processes. The model is broken up into three simultaneous processes: dechlorination, methanogenesis, and fermentation. The system behavior of the methanogenic zone can be adequately described by the classical formulations of representative …

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Identification Of Critical Roles Of Program Managers And Contracting Officers, Daniel R. Shingledecker Mar 2001

Identification Of Critical Roles Of Program Managers And Contracting Officers, Daniel R. Shingledecker

Theses and Dissertations

The purpose of this research was to identify current disagreement among acquisition professionals in regards to their role and authority; and to identify benefits and risks associated with combining program management and contracting officer roles into a single position. The research questions were answered through a literature review and use of the Delphi technique. The literature review indicated that the DoD has been operating with multiple conflicting perceptions of authority among its key acquisition professionals. The literature also identified the need for complex organizations, such as DoD acquisition offices, to pair high levels of responsibility with equally high levels of …

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Locating Target At High Speed Using Image Decimation Decomposition Processing, Zikuan Chen, Mohammad Rezaul Karim, Majeed M. Hayat Mar 2001

Locating Target At High Speed Using Image Decimation Decomposition Processing, Zikuan Chen, Mohammad Rezaul Karim, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

We develop a decimation-decomposition processing technique that consists of judiciously selecting certain decimation-decomposed components of an image and then performing inter-component processing. For a (kx,ky)-decimation decomposition, there may be up to kxky decimation-decomposed components. The minimal surviving and maximal non-surviving lengths associated with inter-component processing algorithm allows for clutter suppression. By removing detection redundancies, one can locate the target at high speed. A “where-then-what” model is proposed for target tracking and recognition. It locates the target by-image decimation-decomposition processing first and then recognizes the target in question using a suitable image recognition technique.

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A Force Structuring Model For A Moderately-Sized Nato Country, Hakan Bal Mar 2001

A Force Structuring Model For A Moderately-Sized Nato Country, Hakan Bal

Theses and Dissertations

The purpose of this research is to develop a mathematical model which will aid the decision-makers of a moderately-sized NATO country to develop their future force structure composition. As the number of alternatives grows, and as the consequences become more important and more uncertain, the force structuring decision becomes increasingly difficult. The valuable lessons of past experience cannot be ignored. However, when one considers the high rotation rates of most countries' air forces, the rapid change in technology and the vast array of options available, even the most experienced leaders need some assistance. Hence, decision support tools are needed to …

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The Applications Of Confocal Raman Micro-Spectroscopy For Study Of Practical Electrode Materials, Yong Yang, Wei Chu, Jun-Min Nan, Xun-Guang Chen, Zu-Geng Lin Feb 2001

The Applications Of Confocal Raman Micro-Spectroscopy For Study Of Practical Electrode Materials, Yong Yang, Wei Chu, Jun-Min Nan, Xun-Guang Chen, Zu-Geng Lin

Journal of Electrochemistry

Some recent research work about applications of confocal Raman micro spectroscopy for study of practical electrode materials carried out in our lab has been briefly introduced. The examples include study of electrochemical Li+ intercalation process, characterization of surface oxide film on AB5 type electrodes and passive film and pitting corrosion of Rebar electrodes.

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Confocal Microprobe Raman Spectroscopy For Investigating The Electrochemical Interface, Bin Ren, Feng-Ming Liu, Xu-Feng Lin, Zhong-Qun Tian Feb 2001

Confocal Microprobe Raman Spectroscopy For Investigating The Electrochemical Interface, Bin Ren, Feng-Ming Liu, Xu-Feng Lin, Zhong-Qun Tian

Journal of Electrochemistry

The invention of the surface enhanced Raman spectroscopy (SERS) in the mid of 1970s, opened an entirely new and very promising area. However, it was found that SERS of practical application in electrochemistry can only be found on noble metal surfaces, such as Ag, Au and Cu that exhibit huge surface enhancement. This greatly limits the application of SERS in electrochemistry.

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Raman And Afm Characterization Of Au And Cu Nanorod And Nanowire Arrays, Jing Tang, Jian-Lin Yao, Kuan-Hong Xue, De-Yin Wu, Long-Gang Lin, Yu-Xiong Jiang, Bin Ren, Xin Xu, Bing-Wei Mao, Zhong-Qun Tian Feb 2001

Raman And Afm Characterization Of Au And Cu Nanorod And Nanowire Arrays, Jing Tang, Jian-Lin Yao, Kuan-Hong Xue, De-Yin Wu, Long-Gang Lin, Yu-Xiong Jiang, Bin Ren, Xin Xu, Bing-Wei Mao, Zhong-Qun Tian

Journal of Electrochemistry

Recently metal nanowires (nanorods) have aroused tremendous interest because of their novel properties and potential applications in wide fields Many two-dimensional nanowire arrays of semiconductors and metals with different diameter and length have been made by using template synthesis method.

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Surface-Enhanced Raman Spectroscopy Of Metallotetraphenyl Porphyrins Adsorbed On Ag2O And Silver Colloids, Ying-Hui Zhang, Dong-Ming Chen, Tian-Jing He, Fan-Chen Liu Feb 2001

Surface-Enhanced Raman Spectroscopy Of Metallotetraphenyl Porphyrins Adsorbed On Ag2O And Silver Colloids, Ying-Hui Zhang, Dong-Ming Chen, Tian-Jing He, Fan-Chen Liu

Journal of Electrochemistry

The biological significance of porphyrins and metalloporphyrins has stimulated intensive investigations on these compounds for many years. On the other hand, porphyrins and metalloporphyrins also have extensive applications in many other fields such as chemical modified electrodes, organic photovoltaic devices and biomimetic catalysis. The adsorption behavior and chemical reactions of metalloporphyrins on surfaces or interfaces are very important for these applications.

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Electrochemical Impedance Spectroscopy Studies On Inhibitive Performance Of Aluminum Triphosphate Pigment, Yong-Gui Liao, Zhi-Jun Gu, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su Feb 2001

Electrochemical Impedance Spectroscopy Studies On Inhibitive Performance Of Aluminum Triphosphate Pigment, Yong-Gui Liao, Zhi-Jun Gu, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su

Journal of Electrochemistry

The epoxy coatings on A3 steel sheets containing calcite or aluminum triphosphate (AlTP), were investigated by Electrochemical Impedance Spectroscopy (EIS). The results showed that calcite pigment is not an inhibitor, but an extender pigment, and that AlTP pigment can considerably enhance the protective performance of epoxy coating. The triphosphate ion at the interface between the steel substrate and the coating can complex with the corrosion product, such as ferric and ferrous ions, and form a compact protective film which effectively separates the steel substrate from the aggressive media.

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A Study On The Performance Of Matrix Prepared By Tape Cast And Its Molten Carbonate Fuel Cells (Mcfcs), Hua-Xin Lin, Bao-Lian Yi, Li Zhou, Chang-Qing He, Lian-Ying Kong, En-Jun Zhang Feb 2001

A Study On The Performance Of Matrix Prepared By Tape Cast And Its Molten Carbonate Fuel Cells (Mcfcs), Hua-Xin Lin, Bao-Lian Yi, Li Zhou, Chang-Qing He, Lian-Ying Kong, En-Jun Zhang

Journal of Electrochemistry

The matrix prepared with γ-LiAlO2 powder and by tape cast displayed higher ability of preventing from gas cross over and lower ohmic polarization. The voltages of the stack (three cells, 122 cm2) stacked with the matrix were 2.02 and 1.78 V at 200 and 246 mA/cm2, respectively, and the output power reached 53.4 W. The cell (28 cm 2) voltages were 0.85 and 0.75 V at 200 and 300 mA/cm2, respectively, and the output power was about 6.6 W. Compensating the shrinkage of matrix in stacking cells promoted the enhancement of the …

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Rhodium As A Ubiquitous Substrate For Surface Enhanced Raman Spectroscopy, Bin Ren, Xu-Feng Lin, Zhong-Qun Tian Feb 2001

Rhodium As A Ubiquitous Substrate For Surface Enhanced Raman Spectroscopy, Bin Ren, Xu-Feng Lin, Zhong-Qun Tian

Journal of Electrochemistry

Raman Spectroscopy is a powerful technique in characterizing the molecular structure at the molecular level. However, only after the discovery of surface enhanced Raman scattering (SERS) effect, has it become one of the most widely used technique in surface sciences. The limitation that only Ag, Au and Cu can produce prominent SERS signal of practical significance, greatly hinders the application of this technique. Recently our group has made great progress in extending SERS to pure transition metal surfaces, such as Pt, Ni, Fe, Co etc.

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Two-Dimensional Surface Raman Imaging Of A Roughened Iron Electrode In Saline Water, Pei-Gen Cao, Jian-Lin Yao, Jun-Wei Zheng, Bin Ren, Ren-Ao Gu, Zhong-Qun Tian Feb 2001

Two-Dimensional Surface Raman Imaging Of A Roughened Iron Electrode In Saline Water, Pei-Gen Cao, Jian-Lin Yao, Jun-Wei Zheng, Bin Ren, Ren-Ao Gu, Zhong-Qun Tian

Journal of Electrochemistry

The analysis of the composite and distribution of iron oxide due to pit corrosion in saline solutions (3.4% NaCl) is of great importance. Many electrochemical methods, XPS, and other photoelectronic techniques have been applied to this domain. Surface enhanced Raman scattering (SERS) spectroscopy can provide the vibrational information of surface species with high sensitivity and is very useful in the study of surface chemistry of iron. Notwithstanding, the application of SERS in iron corrosion is hampered for its SERS-inactivity. Efforts have been devoted to extend the use of SERS to the study of iron.

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The Charge Transfer Effect Of Sers Induced By The Electrochemical Hydrogen Evolution Reaction, Feng-Ming Liu, Qi Han, Yan-Xia Chen, Qi-Ling Zhong, Bin Ren, Zhong-Qun Tian Feb 2001

The Charge Transfer Effect Of Sers Induced By The Electrochemical Hydrogen Evolution Reaction, Feng-Ming Liu, Qi Han, Yan-Xia Chen, Qi-Ling Zhong, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

As one of the important mechanisms of SERS, the charge transfer (CT) enhancement requires the strong interaction of the adsorbed species with the substrate in order to permit the transition of charge between the metal Fermi level (energy state) and the molecular orbital. The high enhancement needs the match of the energy gap between the Fermi level (or surface state) and the orbital energy level of the adsorbed molecules with the energy of the incident light. The electrode Fermi level is usually adjusted by the applied potential to satisfy the CT resonance. For the electrochemical reaction process, the frontier orbital …

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How Can Direct Mthanol Fuel Cell Benefit From Carbonate Media, Lin Zhuang, Yang Wang, Jun-Tao Lu Feb 2001

How Can Direct Mthanol Fuel Cell Benefit From Carbonate Media, Lin Zhuang, Yang Wang, Jun-Tao Lu

Journal of Electrochemistry

The kinetics of methanol oxidation and oxygen reduction in 0.5 mol/L K2CO3 were compared with those in 0.5 mol/L H2SO 4. Experiments revealed that carbonate media could be more beneficial to direct methanol fuel cell(DMFC). Firstly, both electrode reactions show better performance in the carbonate than in the acid; secondly, materials other than noble metals become possible to be used as the anodic and cathodic catalysts; thirdly, the potential dectease caused by methanol crossover could be depressed by using metal oxide catalysts not stable in acid, such as MnO2.

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Synthesis Of Limn2O4-ΔClΔ Cathode Material By Like-Sol-Gel Methode, Zhao-Yong Chen, Yi He, Xing-Quan Liu, Zhi-Jie Li, Zuo-Long Yu Feb 2001

Synthesis Of Limn2O4-ΔClΔ Cathode Material By Like-Sol-Gel Methode, Zhao-Yong Chen, Yi He, Xing-Quan Liu, Zhi-Jie Li, Zuo-Long Yu

Journal of Electrochemistry

LiMn2O4-δClδ was synthesized by like sol gel methode, with calculated LiOH·H2O, Mn(No3)2⋅6H2O and LiCl·H2O, and made electrochemical test with these compounds as positive materials. Result demostrated that LiMn2O4-δClδ cathode material has exellent stability and nearly no capacity loss after reaching stability.

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Raman Spectroelectrochemical Study On Bioactive Molecules, Xiao-Wei Cao, Hai-Feng Yang, Zhe Su Meng Xiao Yun Wang, Xia-Qin Wu, Zong-Rang Zhang Feb 2001

Raman Spectroelectrochemical Study On Bioactive Molecules, Xiao-Wei Cao, Hai-Feng Yang, Zhe Su Meng Xiao Yun Wang, Xia-Qin Wu, Zong-Rang Zhang

Journal of Electrochemistry

Electron-transfer reaction is known to be one of the key reactions for generating biological functions. Mechanism revelation at a molecular level of such kind reactions is to be very helpful for us to understand life essence. In fact, surface enhanced Raman scattering (SERS) is one of the most powerful tools for the study on metal-electrolyte and metal-vacuum interfaces since 1970's. Moreover, Raman spectroscopic study in enzymology has provided attractive results during last twenty-five years.

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In Situ Raman Spectroelectrochemical Characterization Of The Prussian Blue/Platinum Modified Electrode, Xiao-Wei Cao, Rong Wang, Gui-Hua Wang, Zong-Rang Zhang Feb 2001

In Situ Raman Spectroelectrochemical Characterization Of The Prussian Blue/Platinum Modified Electrode, Xiao-Wei Cao, Rong Wang, Gui-Hua Wang, Zong-Rang Zhang

Journal of Electrochemistry

Prussian Blue is known to be deposited electrochemically on the electrode surface, producing a dense redox active layer. Since the Prussian Blue modified electrode was first reported by Neff in 1978, different in situ spectroelectrochemical techniques have been widely used to investigate its electrochemical mechanism. But no research work related to the in situ Raman spectroscopic studies on it has been reported. In this paper we try to characterize the nature of thin Prussian Blue films on platinum substrates with in situ Raman spectroelectrochemical technique.

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Adsorption Behavior Of Co At The Ultrathin Rh And Pt Film Electrodes, Yong Xie, Xiao-Qin Li, Bin Ren, Zhong-Qun Tian Feb 2001

Adsorption Behavior Of Co At The Ultrathin Rh And Pt Film Electrodes, Yong Xie, Xiao-Qin Li, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

Pt group metals have been widely used in catalysis such as hydrogenation of organic compounds and the oxidation of carbon monoxide. The information about CO adsorption on the Pt group surfaces and the influence of other surface species, such as hydrogen and CO2 will be greatly helpful to elucidate the adsorption behavior of CO on Pt group metal surfaces and get a deeper understanding of catalytic mechanisms of Pt group metals. Surface enhanced Raman spectroscopy (SERS) has been becoming an increasingly important means to characterize the electrochemical metal solution interface over the past two decades. Our laboratory has successfully …

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Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode Ii. Eqcm And In-Situ Ftir Spectroscopic Studies In Acid Media, Guo-Liang Chen, Sheng-Pei Chen, Zhi-You Zhou, Chun-Hua Zhen, Shi-Gang Sun Feb 2001

Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode Ii. Eqcm And In-Situ Ftir Spectroscopic Studies In Acid Media, Guo-Liang Chen, Sheng-Pei Chen, Zhi-You Zhou, Chun-Hua Zhen, Shi-Gang Sun

Journal of Electrochemistry

The adsorption and oxidation of ethanol on nm Pt/GC electrode in acid solutions containing 0.1 mol·L -1 H2SO4 +0.1 mol·L -1 CH3CH2OH was investigated by using cyclic voltammetry, EQCM and in situ FTIR spectroscopy. The experimental results demonstrated that the oxidation of CH3CH2OH is closely relaed to solution acidity and oxygen species on electrode surface; CH3CH2OH was oxidized on nm Pt/GC electrode in acidic media via a dual path reaction mechanism, i.e . CH3CH2OH may be oxidized into CO2 through …

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The Photoelectrochemistry Of Tio2-Polyaniline Composite Film, Huai-Guo Huang, Zhi-Xin Zheng, Jin Luo, Hong-Ping Zhang, Ling-Ling Wu, Zhong-Hua Lin Feb 2001

The Photoelectrochemistry Of Tio2-Polyaniline Composite Film, Huai-Guo Huang, Zhi-Xin Zheng, Jin Luo, Hong-Ping Zhang, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

A TiO2 and polyaniline (PANI) composite film was obtained by electrochemical methods. The SEM image of the composite film showed that the PANI film is almost completely covered with TiO2 efficiency. The spectra of photocurrent for the TiO2-PANI composite film were different from these of TiO2 film photosensitized by PANI. The bandgap energy of TiO2 film on partially oxidized PANI film was determined as 3.0 eV by the threshold energy of photocurrent band for TiO2. The spectra of photocurrent for partially oxidized PANI film electrode suggested that it has the characteristics of …

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Catalytic Effect Of Cl- On Electrodeposition Of Binary Zinc Alloys With Iron Group Metals, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao, A.Za Karia, Rong-Ming Zhou Feb 2001

Catalytic Effect Of Cl- On Electrodeposition Of Binary Zinc Alloys With Iron Group Metals, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao, A.Za Karia, Rong-Ming Zhou

Journal of Electrochemistry

Zinc iron group metal alloys were deposited under coulostatic (10C⋅cm-2) at 40 ℃ chloride baths. The deposited alloys were quantitatively analyzed by Atomic Absorption Spectrometry. The current efficiency, percent content and partial polarization curves were obtained by the results. The morphology of the deposits was observed by means of Scanning Electron Microscopy(SEM). We observe that the electrodeposition of zinc iron group metal alloys is one of the best known examples of anomalous codeposition. We found the catalytic effect of Cl- on the electrodeposition behavior of iron group metal. Overpotential of iron group metal droped abruptly at high …

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Immunosorbents With Developed Binding Efficiency And Method Of Manufacture , William H. Velander Feb 2001

Immunosorbents With Developed Binding Efficiency And Method Of Manufacture , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

The antitope of an antibody is masked with a masking agent, followed by immobilization on a support. The masking agent is then eluted to produce an improved immunosorbent, which is capable of binding more than double the amount of an antigen than existing immunosorbents having the same antibody bound at the same density. Preferably, the masking agent is an antigen or other compound having an epitope for which the antitope of the bound antibody has an avidity. In a preferred embodiment, greater than 30% of the bound antibodies maintain the same vicinity as when unbound for specific antigen or hapten …

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Proactive Rideshare Opportunity Brokering Services (Probs), Robert J. Twiggs, Brian Horais, Charles Byvik Feb 2001

Proactive Rideshare Opportunity Brokering Services (Probs), Robert J. Twiggs, Brian Horais, Charles Byvik

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professors Bob Twiggs, Brian Horais, and Charles Byvik titled "Proactive Rideshare Opportunity Brokering Services (PROBS) presented at the 2001 IEEE Aerospace Conference on February 26, 2001.

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Enhanced Transition Temperature In A Quantum Confined High-TC Superconductor, L. Menon, D. Yu, Yi Liu, B. Jayaram Feb 2001

Enhanced Transition Temperature In A Quantum Confined High-TC Superconductor, L. Menon, D. Yu, Yi Liu, B. Jayaram

P. F. (Paul Frazer) Williams Publications

A slight enhancement of the onset transition temperature Tc has been observed in quantum dots of the high-Tc superconductor yttrium–barium–copper oxide (Y1Ba2Cu3O7-δ). The dots were formed when YBCO particles (diameter ≤600 nm) were exposed to an RF plasma to produce a Coulomb crystal. The plasma damages the particles and causes 20–25 nm sized isolated islands of the correct 1-2-3 stoichiometry to segregate within each particle. We believe that quantum confinement of carriers within these islands leads to discretization of the quasi-particle density-of-states which can account for the slight increase …

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Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm Feb 2001

Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

A biodegradable polyester resin was polymerized from N-benzyloxycarbonyl-L-glutamic acid and ethylene glycol. Rhizopus delemar lipase was used as a biocatalyst for the rupture of ester bonds during the hydrolysis studies. Depoly-merization was observed to followa Michaelis–Menten mechanism, with the maximumrate of monomer formation dP/dtmax = 1.12 x 10-8 mol/s and the rate constant Km x 2.03 x 10-4 mol. Subject to initial conditions described by the most probable distribution and Michaelis–Menten–type depolymerization rate expressions, population density distribution dynamics of the polymeric molecules that formed the resin were explicitly described using a deterministic approach.

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Semiautomated Skeletonization Of The Pulmonary Arterial Tree In Micro-Ct Images, Christopher C. Hanger, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson Feb 2001

Semiautomated Skeletonization Of The Pulmonary Arterial Tree In Micro-Ct Images, Christopher C. Hanger, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

We present a simple and robust approach that utilizes planar images at different angular rotations combined with unfiltered back-projection to locate the central axes of the pulmonary arterial tree. Three-dimensional points are selected interactively by the user. The computer calculates a sub- volume unfiltered back-projection orthogonal to the vector connecting the two points and centered on the first point. Because more x-rays are absorbed at the thickest portion of the vessel, in the unfiltered back-projection, the darkest pixel is assumed to be the center of the vessel. The computer replaces this point with the newly computer-calculated point. A second back-projection …

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