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2001

Materials Science and Engineering

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Articles 31 - 60 of 142

Full-Text Articles in Engineering

Highly Plasma Etch-Resistant Photoresist Composition Containing A Photosensitive Polymeric Titania Precursor, Tony D. Flaim, Douglas J. Guerrero, Michelle R. Fowler, William Joseph James, Vladimir Petrovsky, Harlan U. Anderson Oct 2001

Highly Plasma Etch-Resistant Photoresist Composition Containing A Photosensitive Polymeric Titania Precursor, Tony D. Flaim, Douglas J. Guerrero, Michelle R. Fowler, William Joseph James, Vladimir Petrovsky, Harlan U. Anderson

Chemistry Faculty Research & Creative Works

A composition is derived from an addition polymerizable organotitanium polymer which upon exposure to an oxygen plasma or baking in air, is converted to titanium dioxide (titania) or is converted to a mixed, titanium-containing metal oxide. The metal oxide formed in situ imparts etch- resistant action to a patterned photoresist layer. The composition may also be directly deposited and patterned into permanent metal oxide device features by a photolithographic process.


The Current State Of Research On Academic Dishonesty Among Engineering Students, Trevor S. Harding, Donald D. Carpenter, Susan M. Montgomery, Nicholas H. Steneck Oct 2001

The Current State Of Research On Academic Dishonesty Among Engineering Students, Trevor S. Harding, Donald D. Carpenter, Susan M. Montgomery, Nicholas H. Steneck

Materials Engineering

Academic dishonesty, or cheating, has become a serious problem at colleges and universities. This is particularly true of engineering students who, are among the most likely to cheat in college. The present paper reviews the literature as a basis of broadly understanding academic dishonesty. This discussion focuses on three primary issues: (1) perceptions of and attitudes towards cheating, (2) reasons for student cheating, and (3) methods of promoting academic integrity. A current research project being developed by the authors is also discussed. The premise of this research is that students are constantly making ethical judgements between the pressure to cheat …


Odpady Pestycydowe Jako Paliwo Zastępcze W Piecach Obrotowych Do Wypalania Klinkieru Cementowego, Marian Mazur, Robert Oleniacz, Marek Bogacki, Stanisław Słupek Oct 2001

Odpady Pestycydowe Jako Paliwo Zastępcze W Piecach Obrotowych Do Wypalania Klinkieru Cementowego, Marian Mazur, Robert Oleniacz, Marek Bogacki, Stanisław Słupek

Robert Oleniacz

The clinker burning plant is ideally suited for processing a wide variety of hazardous waste materials. High temperatures existing in cement kilns (ca. 1350-1450 Centigrades in the burning zone) as well as long gas-residence time (ca. 6-10 s) provide potentially excellent conditions for destruction of toxic organic compounds. Non-volatile compounds are retained in the solid phase and built into the clinker. A lot of other (for example acid gases) can also be absorbed by alkaline solid phase. Old pesticide wastes present a big problem in Poland now. They can be use as waste-derived fuels in cement kilns, especially in the …


Process For Making A Lubricating Composition, Stephen J. Miller, Gerald P. Huffman, Naresh Shah Sep 2001

Process For Making A Lubricating Composition, Stephen J. Miller, Gerald P. Huffman, Naresh Shah

Chemical and Materials Engineering Faculty Patents

The invention includes a process of making a lubricating oil composition including: a process for making a high VI lubricating oil composition including the steps of (1) contacting a waste plastics feed including mainly polyethylene in a pyrolysis zone at pyrolysis conditions, whereby at least a portion of the waste plastics feed is cracked, thereby forming a pyrolysis zone effluent including 1-olefins and n-paraffins; (2) passing the pyrolysis zone effluent, including a heavy fraction and a middle fraction, the pyrolysis effluent middle fraction including 1-olefins, to a separations zone; where the pyrolysis effluent heavy fraction portion is separated from the …


Hfco2 Laves Phase Intermetallics - Part Ii: Elastic And Mechanical Properties As A Function Of Composition, Katherine C. Chen, Fuming Chu, Paul G. Kotula, Dan Thoma Sep 2001

Hfco2 Laves Phase Intermetallics - Part Ii: Elastic And Mechanical Properties As A Function Of Composition, Katherine C. Chen, Fuming Chu, Paul G. Kotula, Dan Thoma

Materials Engineering

In efforts to establish and understand structure–property relationships in Laves phase intermetallics, elastic and mechanical properties are studied as a function of composition in the C15 HfCo2 system. Elastic constants and Debye temperatures are determined by resonant ultrasound spectroscopy (RUS) at room temperature. A maximum near the stoichiometric Laves composition is revealed with the Young's modulus, bulk modulus, and Poisson's ratio. In addition, a slight drop in shear modulus is found with Co-rich compositions, and the Debye temperature increases with Co-content. Room temperature Vickers indentation is performed to assess the microhardness and fracture toughness of the HfCo2 alloys. …


Hfco2 Laves Phas Intermetallics - Part I: Solubility Limits And Defect Mechanisms, Katherine C. Chen, Eric J. Peterson, Dan J. Thoma Sep 2001

Hfco2 Laves Phas Intermetallics - Part I: Solubility Limits And Defect Mechanisms, Katherine C. Chen, Eric J. Peterson, Dan J. Thoma

Materials Engineering

Solubility limits and constitutional defects in Laves phase intermetallics are investigated with the C15 HfCo2 system. Several binary alloy compositions based on HfCo2 are characterized by optical and scanning electron microscopy (SEM), electron microprobe analysis (EPMA), X-ray diffraction (XRD), and density measurements. Rietveld refinements of XRD scans are used to determine lattice constants, anisotropic strain parameters, and atomic occupancies. Compositional trends are compared against predicted or calculated trends due to an anti-site substitution or vacancy defect mechanism. Geometric models and atomic size factors are used to establish solubility limits and to give insight into defect mechanisms. Results from …


Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (June 1 – August 31, 2001) Report, Ajit K. Roy, Brendan O'Toole Sep 2001

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (June 1 – August 31, 2001) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The subject task entitled “Hydrogen-Induced Embrittlement of Candidate Target Materials for Applications in Spallation-Neutron-Target Systems” had commenced during the quarter ending on August 31, 2001. A research account has been established, contracts for both faculty and students have been prepared, and efforts are well underway to embark on the related research activities, as proposed.

As the title of this project implies, the primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallationneutron- target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). …


Development Of An Integrated Photonic Sensor For Monitoring Hazardous Organics, Dianhong Luo Aug 2001

Development Of An Integrated Photonic Sensor For Monitoring Hazardous Organics, Dianhong Luo

Dissertations

In this study, an integrated photonic sensor has been designed and fabricated for the purpose of monitoring hazardous organics in the environment. The operation of the sensor is based on the principles of the Mach-Zehnder interferometry. The sensor consists of a patterned waveguide structure made of phosphosilicate core and silica cladding. LPCVD processes were developed to produce undoped cladding and doped core silicon dioxide films. Diethylsilane (DES), Trimethylphosphite (TMP) and oxygen were used as the precursors for the deposition process. The effects of the O2/DES ratio and deposition temperature on the properties Of SiO2 films were investigated. …


High Solid Loading Aqueous Base Metal/Ceramic Feedstock For Injection Molding, Mohammad Behi Aug 2001

High Solid Loading Aqueous Base Metal/Ceramic Feedstock For Injection Molding, Mohammad Behi

Dissertations

Increasing volume fraction of metal powder in feedstock provided lower shrinkage. Reduction of the shrinkage results in better dimensional precision. The rheology of the feedstock material plays an important role to allowing larger volume fractions of the metal powder to be incorporated in the feedstock forinulations. The viscosity of the feedstock inainly depends on the binder viscosity, powder volume fraction and characteristics of metal powder.

Aqueous polysaccharide agar was used as a baseline binder system for this study.The effect of several gel-strengthening additives on 1.5wt% and 2wt% agar gel was evaluated. A new gel-strengthening additive was found to be the …


Characterization Of Alpha And Beta Phases Of Tantalum Coatings, Anto Yohannan Aug 2001

Characterization Of Alpha And Beta Phases Of Tantalum Coatings, Anto Yohannan

Theses

Sputtered tantalum forms two phases - α and β. The α and β phases have distinctly different crystalline structures and properties. The structure and the causes of formation of the β phase are still being studied by researchers. This is a study to distinguish and characterize these two phases. Samples from Bennet Labs and NJIT were characterized using techniques such as SEM, EDX, XRF, XRD, TEM and XAFS. Samples deposited at NJIT were used for an experimental study on the conditions favoring the formation of the phases, by depositing tantalum on heated steel and silicon substrates, additionally TEM analysis was …


Disclination Loop Behavior Near The Nematic-Isotropic Transition, Nikolai V. Priezjev, Robert A. Pelcovits Aug 2001

Disclination Loop Behavior Near The Nematic-Isotropic Transition, Nikolai V. Priezjev, Robert A. Pelcovits

Mechanical and Materials Engineering Faculty Publications

We investigate the behavior of disclination loops in the vicinity of the first-order nematic-isotropic transition in the Lebwohl-Lasher and related models. We find that two independent measures of the transition temperature, the free energy, and the distribution of disclination line segments, give essentially identical values. We also calculate the distribution function D(p) of disclination loops of perimeter p and fit it to a quasiexponential form. Below the transition, D(p) falls off exponentially, while in the neighborhood of the transition, it decays with a power-law exponent approximately equal to 2.5, consistent with a “blowout” of loops at the transition. In a …


Microstructure And Electrochemical Properties Of The Melt_Spinning Zr_(0.9)Ti_(0.1) (Ni,Co,Mn,V)_(2.1) Alloy, Ming-Fen Wen, Yu-Chun Zhai, Lian Chen, Min Tong, Hua Zhen, Rong-Jun Ma Aug 2001

Microstructure And Electrochemical Properties Of The Melt_Spinning Zr_(0.9)Ti_(0.1) (Ni,Co,Mn,V)_(2.1) Alloy, Ming-Fen Wen, Yu-Chun Zhai, Lian Chen, Min Tong, Hua Zhen, Rong-Jun Ma

Journal of Electrochemistry

The microstructure and electrochemical properties of Zr 0.9 Ti 0.1 (Ni,Co,Mn,V) 2.1 alloys prepared by both the melt_spinning method and the conventional induction melting were investigated. XRD studies show that Zr 0.9 Ti 0.1 (Ni,Co,Mn,V) 2.1 alloys at as_cast,melt_spinning and annealing are all face center cubic structure with C15 laves phase,the higher the melt_spinning rate,the more the amorphous content.The electrochemical measurements show that melt_spinning alloys have better active behavior,low discharge capacity(<280 mAh/g); but after annealed,the alloys are activated completely with 30 cycles, the capacities about 340 mAh/g are higher than those of as_cast and melt_spinning alloys;the annealec alloys have a better cycle stability than that of as_cast alloy, and the higher the melt_spinning rate is, the more stable the alloy becomes; at 300 mAh/g current density,the capacity of annealed 40 m/s alloy is up to 85% of the maximum capacity after 800 cycles, the capacity decay rate is about 6.9%.


In Situ Ftir Reflection Spectroscopy Of Bioelectrode, Sa-Ying Dong, Guang-Yu Zhao, Yuzhu Gao, Guang-Zhang Chen, Ming-Xiang Lv Aug 2001

In Situ Ftir Reflection Spectroscopy Of Bioelectrode, Sa-Ying Dong, Guang-Yu Zhao, Yuzhu Gao, Guang-Zhang Chen, Ming-Xiang Lv

Journal of Electrochemistry

In situ FTIR reflection spectroscopy was used to study mediated enzyme electrode and immunoelectrode. We determined and analyzed IR characteristic spectra of GOD and glucose by the use of potential difference spectra and single beam subtractive spectra. At last, we explored the IR absorption characters of enzyme_immunoelectrode.


Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin Aug 2001

Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin

Journal of Electrochemistry

The periodic,aperiodic,chaotic and mixed_mode oscillations can occur in the process of the anodic electrodissolution of carbon steel in the solution of dilute phosphoric acid. More plentiful dynamic behaviors can be found in this system compared with the system of Fe/H 3PO 4/Pt.


A New Method For Impregnating Nafion Solution Into The Electrode Of Pemfc, Qian Tang, Ming Han, Bao-Lian Yi, Zhi-Yin Lin Aug 2001

A New Method For Impregnating Nafion Solution Into The Electrode Of Pemfc, Qian Tang, Ming Han, Bao-Lian Yi, Zhi-Yin Lin

Journal of Electrochemistry

We have developed a new method for impregnating Nafion solution into the catalyst layer of homemade hydrophobic electrode using capillary process. Those electrodes show better performance and higher utilization of catalyst (detected by CV and TEM) than traditional spray method in PEMFC. According to the results of SEM photograph and linear_analysis of sulfur and platinum for the electrode cross_section, we can conclude that the resin is uniform in the catalyst layer and has almost same depth as catalyst in the impregnated electrode. While in traditional method resin is not uniform in the catalyst layer and penetrates into the diffusion layer, …


The Coulostatic Method For Evaluating Corrosion In Reinforced Concrete, Yong Tao Zhao, Jian Hua Wu, Chang-Jiu Zhao Aug 2001

The Coulostatic Method For Evaluating Corrosion In Reinforced Concrete, Yong Tao Zhao, Jian Hua Wu, Chang-Jiu Zhao

Journal of Electrochemistry

In the present paper, the application of the coulostatic method to the corrosion of steel in concrete was reviewed. By comparing with other electrochemical techniques, the results obtained in the previous work reveal that the coulostatic method is an interesting alternative to the usual procedures for estimation of corrosion rate, and is better than them in some respects. The main advantages are as follows. The signal to be used can be instantaneous and as small as desired, so the electrode is minimally perturted during the measuring process. In addition, it is as rapid and quantitative, and at least as reliable …


Charge/Discharge Characteristics And Structural Changing Of Spherical Β-Ni(Oh)_2 Prepared From Different Nickel Salt, Shu-Ting Yang, Yan-Hong Yin, Hong-Jun Chen, Jun-Hua Jia, Ming-Chum Zhang, Li Ding Aug 2001

Charge/Discharge Characteristics And Structural Changing Of Spherical Β-Ni(Oh)_2 Prepared From Different Nickel Salt, Shu-Ting Yang, Yan-Hong Yin, Hong-Jun Chen, Jun-Hua Jia, Ming-Chum Zhang, Li Ding

Journal of Electrochemistry

Spherical β Ni(OH) 2 was prepared from different nickel salt by homogeneous complexing precipitation method. Its charge/discharge and cyclic voltammetry properties were studied. The authors found that there are many differences in the electrochemical properties of the prepared Ni(OH) 2.The specific capacity, cycling life and the discharging plateau of the material prepared from NiSO 4 were superior to those of the material prepared from Ni(NO 3) 2.The reasons of the differences were analyzed by XRD and FTIR measurements, which will become abasis for the selection of raw materials.


Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu Aug 2001

Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu

Journal of Electrochemistry

The possibility of electrodeposition of rare earth alloys from aqueous bath was investigated using varous techniques such as linear potential sweeping, cyclic voltammetry, electrodepositon at constant potential etc. The Ni Ce P alloys with different cerium content were electrodeposited from a weakly acidic solution containing CeCl 3, NaH 2PO 2 and so on the crystal structure and component were characterized by XPS, AES, XRD and SEM observation. The codeposits were found to be more highly corrosion resistent than that of Ni P amorphous alloys by measuring polarization resistance and corrosion potential. The effects of codeposition conditions on the corrosion resistance …


An Analytic Approach Describing Structural Effects On The Properties Of Molecular Fluids, Richard Alan Lesar Aug 2001

An Analytic Approach Describing Structural Effects On The Properties Of Molecular Fluids, Richard Alan Lesar

Richard Alan Lesar

An analytic approach is used to evaluate how the angular structure of a molecular fluid contributes to its thermodynamic properties. The average interactions (energy, forces, etc.) between molecules are first expressed as integrals over a spherical-harmonic expansion of the pair distribution function of the fluid. Angularly averaged interactions for systems described by site−site representations of the intermolecular potentials are then developed. Specifically, homonuclear diatomic molecules described by two-site potential are considered in this paper. These results are used to examine the role that fluid structure plays in determining the average energy, pressure, and forces on a molecule, using as comparison …


The Influence Of Membrane Resistance On The Electrochemical Behavior Of Gold Electrode Modified By Self-Assembled Monolayer, Xiao-Li Cui, Zhi-Yu Jiang Aug 2001

The Influence Of Membrane Resistance On The Electrochemical Behavior Of Gold Electrode Modified By Self-Assembled Monolayer, Xiao-Li Cui, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical behavior of gold electrode modified by hexadecanethiol self_assembled monolayer (SAM) in the solution of Fe(CN) 6 3- /Fe(CN) 6 4- was investigated by cyclic voltammetry and ac impedance spectroscopy. The pinhole_free SAM_modified gold electrode has excellent blocking properties to the interfacial electron transfer from redox couple in solution to the substrate. The current increased exponentially with the overpotential at the high potential region. A good linear relationship between ln( I/η ) and η 1/2 was observed. A model system Au/SAM/Hg was constructed and its I~V curve was measured. Similar phenomena were observed. There was also a linear relationship …


Characterization And Electrochemical Investigation Of Boron-Doped Mesocarbon Microbeads Anode Materials For Lithium-Ion Battery, Mao-Hui Chen, Guo-Tao Wu, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin Aug 2001

Characterization And Electrochemical Investigation Of Boron-Doped Mesocarbon Microbeads Anode Materials For Lithium-Ion Battery, Mao-Hui Chen, Guo-Tao Wu, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The anodic performances of boron doped and undoped mesocarbon microbeads(MCMBs) were comparatively studied and the structures were characterized by XPS,SEM,XRD and electrochemical measurements. It was found that boron doping samples greatly increased the degree of graphitization and the crystallite size,leading to quite different morphology. Electrochemical discharge/charge cycle tests indicate that lithium intercalation occurred at a little higher potential for the boron doped MCMBs, being attended by greater irreversible capacity loss.


The Activation Mechanism Of Al Alloys With Tin And Gallium In Alkaline Electrolytes, Zhen Ya Li, Ling Yi, Zhi Hui Liu, Lin Yang, Jing Xin Su, Yan Ying Chen Aug 2001

The Activation Mechanism Of Al Alloys With Tin And Gallium In Alkaline Electrolytes, Zhen Ya Li, Ling Yi, Zhi Hui Liu, Lin Yang, Jing Xin Su, Yan Ying Chen

Journal of Electrochemistry

The major reason for Al_anode's activation is that Ga and Sn deposit on the aluminum surface and form activated points. The Al_Sn and Al_Ga binary alloys can't be activated in alkaline medium. During the dissolution of the Al_Sn_Ga ternary anode, Sn and Ga dissolve into the solution and transform into ions. After the Sn ions deposit on the surface of Al_anode, the Ga ions will deposit on Sn. The higher activation of the polynary alloy anode is caused by much more new activated points composed of Ga_Sn alloy being continually formed. Ga_Sn alloy with low melting point deposited on the …


Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian Xia Yuan, Nai Xin Xu Aug 2001

Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian Xia Yuan, Nai Xin Xu

Journal of Electrochemistry

Electrochemical impedance spectroscopy was employed to determine the hydrogen diffusion coefficient in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 metal hydride electrode with various states of charge(SOC) at room temperature and with 50% SOC at various temperatures. It was found that hydrogen diffusion coefficient in this electrode decreases with the increase in SOC at ambient temperature, and for the electrode with 50%SOC, hydrogen diffusion coefficient increases with the increase of temperature and the activation energy for hydrogen diffusion in it is 35 kJ/mol.


Modeling, Fabrication, And Optimization Of Niobium Cavities – Phase I: Quarterly Progress Report May 15, 2001 - August 15, 2001, Robert A. Schill Jr., Mohamed Trabia Aug 2001

Modeling, Fabrication, And Optimization Of Niobium Cavities – Phase I: Quarterly Progress Report May 15, 2001 - August 15, 2001, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Multipacting is one of the major loss mechanisms in rf superconductivity cavities for accelerators. This loss mechanism limits the maximum amount of energy/power supported by the cavities. Optimal designs have been identified in others’ studies. In practice, these designs are not easily manufactured. Chemical etching processes used to polish the cavity walls result in a nonuniform surface etch compromising the optimal geometrical design. Past multipacting studies have not examined the impact of wall perturbations.

It is the purpose of this study to examine the chemical etching process in the design of niobium cavities so to maximize the surface quality of …


Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry Aug 2001

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

The goal is to achieve a basic understanding of the corrosion of stainless steel by Lead Bismuth Eutectic (LBE), which has been proposed for use in the transmuter as both a coolant and as a sputtering target.


Finite-Temperature Dislocation Interactions, Richard Alan Lesar, J. M. Rickman Aug 2001

Finite-Temperature Dislocation Interactions, Richard Alan Lesar, J. M. Rickman

Richard Alan Lesar

We obtain quantitatively the interaction free energy between two fluctuating dislocation lines that are in contact with a thermal bath. By examining both in-plane and transverse-fluctuation polarizations, we identify attractive and repulsive contributions to the free energy and interpret the results in terms of effective multipolar interactions and the screening of separated lines. We find that the usual form of the dislocation force should be modified to include an additional net attractive force when entropic effects are taken into account.


Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823 For Transmutation Applications, Ajit K. Roy, Brendan O'Toole Aug 2001

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823 For Transmutation Applications, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the elevated temperature tensile properties of Alloy EP- 823, a leading target material for accelerator-driven waste transmutation applications. This alloy has been proven to be an excellent structural material to contain the lead-bismuth-eutectic (LBE) nuclear coolant needed for fast spectrum operations. However, very little data exist in the open literature on the tensile properties of this alloy. The selection of Alloy EP-823 as the test material in the proposed task is based on the recommendation of our collaborator at the Los Alamos National Laboratory (LANL). The test material will be thermally treated …


Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen Aug 2001

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes of two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. …


Effect Of Bonding Variables In Thermal Bonding Of Polypropylene Nonwovens, Praveen Kumar Jangala Aug 2001

Effect Of Bonding Variables In Thermal Bonding Of Polypropylene Nonwovens, Praveen Kumar Jangala

Doctoral Dissertations

The aim of this research was to investigate the effect of some of the process variables on the structure and properties of the webs in a thermal point bonding process. The main objectives were to understand the changes taking place in the fiber structure due to applied heat and pressure, the effect of bond area and bond size on fiber morphology, and the physical properties of the web. Thermally bonded carded webs were produced and characterized in order to determine the role of bond area and bond size on strength and stiffness of the point bonded fabrics and fiber morphology. …


Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy Aug 2001

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the effect of hydrogen on cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The test materials will undergo appropriate thermal treatments prior to being hydrogen-charged by potentiostatic cathodic polarization technique in a simulated aqueous environment at different temperatures of interest. The specimens, upon completion of testing, will be metallographically examined. Further, the scanning electron microscopy (SEM) will be used to determine the extent and nature of cracking in the specimens tested. The thrust of the proposed …