Mine-to-Mill Optimization of Aggregate Production (open access)

Mine-to-Mill Optimization of Aggregate Production

Mine-to-Mill optimization is a total systems approach to the reduction of energy and cost in mining and processing. Developed at the Julius Krutschnitt Mineral Research Center in Queensland, Australia, the Mine-to-Mill approach attempts to minimize energy consumption through optimization of all steps in the size reduction process. The approach involves sampling and modeling of blasting and processing, followed by computer simulation to optimize the operation and develop alternatives. The most promising alternatives are implemented, and sampling is conducted to quantify benefits. In the current project, the primary objective was to adapt Mine-to-Mill technology to the aggregates industry. The first phase of this work was carried out at the Bealeton Quarry near Fredericksburg, Virginia. The second phase was carried out at the Pittsboro Quarry south of Chapel Hill, North Carolina. Both quarries are operated by Luck Stone Corporation of Richmond, Virginia. As a result of the work, several conclusions can be drawn from the project which should assist DOE in assessing the applicability of the Mine-to-Mill approach to the aggregates industry. 1. Implementation of MTM guidelines at Pittsboro has resulted in tangible improvements in productivity. It is clear that MTM guidelines represent an energy savings of around 5% (primary and secondary) …
Date: September 30, 2006
Creator: Adel, Greg; Kojovic, Toni & Thornton, Darren
Object Type: Report
System: The UNT Digital Library
Improved Tubulars for Better Economics in Deep Gas Well Drilling Using Microwave Technology (open access)

Improved Tubulars for Better Economics in Deep Gas Well Drilling Using Microwave Technology

The main objective of the entire research program has been to improve the rate-of-penetration in deep hostile environments by improving the life cycle and performance of coiled-tubing, an important component of a deep well drilling system for oil and gas exploration, by utilizing the latest developments in the microwave materials technology. Based on the results of the Phase I and insurmountable difficulties faced in the extrusion and de-waxing processes, the approach of achieving the goals of the program was slightly changed in the Phase II in which an approach of microwave sintering combined with Cold Isostatic Press (CIP) and joining (by induction or microwave) has been adopted. This process can be developed into a semicontinuous sintering process if the CIP can produce parts fast enough to match the microwave sintering rates. The main objective of the Phase II research program is to demonstrate the potential to economically manufacture microwave processed coiled tubing with improved performance for extended useful life under hostile coiled tubing drilling conditions. After the completion of the Phase II, it is concluded that scale up and sintering of a thin wall common O.D. size tubing that is widely used in the market is still to be proved …
Date: September 30, 2006
Creator: Agrawal, Dinesh
Object Type: Report
System: The UNT Digital Library
Fundamentals of Natural Gas and Species Flows from Hydrate Dissociation - Applications to Safety and Sea Floor Instability (open access)

Fundamentals of Natural Gas and Species Flows from Hydrate Dissociation - Applications to Safety and Sea Floor Instability

Semi-analytical computational models for natural gas flow in hydrate reservoirs were developed and the effects of variations in porosity and permeability on pressure and temperature profiles and the movement of a dissociation front were studied. Experimental data for variations of gas pressure and temperature during propane hydrate formation and dissociation for crushed ice and mixture of crushed ice and glass beads under laboratory environment were obtained. A thermodynamically consistent model for multiphase liquid-gas flows trough porous media was developed. Numerical models for hydrate dissociation process in one dimensional and axisymmetric reservoir were performed. The computational model solved the general governing equations without the need for linearization. A detail module for multidimensional analysis of hydrate dissociation which make use of the FLUENT code was developed. The new model accounts for gas and liquid water flow and uses the Kim-Boshnoi model for hydrate dissociation.
Date: September 30, 2006
Creator: Ahmadi, Goodarz
Object Type: Report
System: The UNT Digital Library
Project Work Plan 100-N Area Strontium-90 Treatability Demonstration Project: Phytoremediation Along the 100-N Columbia River Riparian Zone (open access)

Project Work Plan 100-N Area Strontium-90 Treatability Demonstration Project: Phytoremediation Along the 100-N Columbia River Riparian Zone

The 100-N Area Innovative Treatment and Remediation Demonstration (ITRD) identified phyto¬remediation as a potential technology both for the removal of 90Sr from the soil of the riparian zone and as a filter for groundwater along the Columbia River. Recent greenhouse and growth chamber studies have demonstrated the viability of phytoextraction to remove 90Sr from this area’s soil/water; in conjunction with monitored natural attenuation and an apatite barrier the process would make an effective treatment for remediation of the 100-N Area 90Sr plume. All activities associated with the 100-NR-1 and 100-NR-2 Operable Units of the Hanford 100-N Area have had, and continue to have, significant regulatory and stakeholder participation. Beginning in 1998 with the ITRD process, presentations to the ITRD TAG were heavily attended by EPA, Washington State Department of Ecology, and stakeholders. In addition, three workshops have been held to receive regulatory and stakeholder feedback on monitored natural attenuation, the apatite barrier, and phytoremediation; these were held in Richland in August 2003, December 2004, and August 2005. The apatite injection treatability test plan (DOE 2005) describes phytoremediation as a technology to be evaluated during the March 2008 evaluation milestone as described in the Tri-Party Agreement change request (M-16-06-01 Change Control …
Date: April 30, 2006
Creator: Ainsworth, Calvin C.
Object Type: Report
System: The UNT Digital Library
Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals (open access)

Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

This project extends previously discovered Fe-based catalysts to hydrogen-poor synthesis gas streams derived from coal and biomass sources. These catalysts have shown unprecedented Fischer-Tropsch synthesis rates and selectivities for feedstocks consisting of synthesis gas derived from methane. During the first reporting period, we certified a microreactor, installed required analytical equipment, and reproduced synthetic protocols and catalytic results previously reported. During the second reporting period, we prepared several Fe-based compositions for Fischer-Tropsch Synthesis and tested the effects of product recycle under both subcritical and supercritical conditions. During the third and fourth reporting periods, we improved the catalysts preparation method, which led to Fe-based FT catalysts with the highest FTS reaction rates and selectivities so far reported, a finding that allowed their operation at lower temperatures and pressures with high selectivity to desired products (C{sub 5+}, olefins). During the fifth reporting period, we studied the effects of different promoters on catalytic performance, specifically how their sequence of addition dramatically influenced the performance of these materials in the Fischer-Tropsch synthesis. We also continued our studies of the kinetic behavior of these materials. Specifically, the effects of H{sub 2}, CO, and CO{sub 2} on the rates and selectivities of Fischer-Tropsch Synthesis reactions led us …
Date: September 30, 2006
Creator: Akio; Ishikawa; Ojeda, Manuel; Yao, Nan & Iglesia, Enrique
Object Type: Report
System: The UNT Digital Library
Plasma Biasing to Control the Growth Conditions of Diamond-Like Carbon (open access)

Plasma Biasing to Control the Growth Conditions of Diamond-Like Carbon

It is well known that the structure and properties ofdiamond-like carbon, and in particular the sp3/sp2 ratio, can becontrolled by the energy of the condensing carbon ions or atoms. In manypractical cases, the energy of ions arriving at the surface of thegrowing film is determined by the bias applied to the substrate. The biascauses a sheath to form between substrate and plasma in which thepotential difference between plasma potential and surface potentialdrops. In this contribution, we demonstrate that the same results can beobtained with grounded substrates by shifting the plasma potential. This"plasma biasing" (as opposed to "substrate biasing") is shown to workwell with pulsed cathodic carbon arcs, resulting in tetrahedral amorphouscarbon (ta-C) films that are comparable to the films obtained with theconventional substrate bias. To verify the plasma bias approach, ta-Cfilms were deposited by both conventional and plasma bias andcharacterized by transmission electron microscopy (TEM) and electronenergy loss spectrometry (EELS). Detailed data for comparison of thesefilms are provided.
Date: April 30, 2006
Creator: Anders, Andre; Pasaja, Nitisak; Lim, Sunnie H.N.; Petersen, TimC. & Keast, Vicki J.
Object Type: Article
System: The UNT Digital Library
The International Linear Collider Beam Dumps (open access)

The International Linear Collider Beam Dumps

The ILC beam dumps are a key part of the accelerator design. At Snowmass 2005, the current status of the beam dump designs was reviewed, and the options for the overall dump layout considered. This paper describes the available dump options for the baseline and the alternatives and considers issues for the dumps that require resolution.
Date: January 30, 2006
Creator: Appleby, R.; Keller, L.; Markiewicz, T.; Seryi, A.; Walz, D. & Sugahara, R.
Object Type: Article
System: The UNT Digital Library
The European Parliament (open access)

The European Parliament

This report mainly discusses The European Parliament which is a key institution of 25 member European Union. The role of the European Parliament in the legislative has expanded steadily over time as the scope of EU policy has grown.
Date: March 30, 2006
Creator: Archick, Kristin
Object Type: Report
System: The UNT Digital Library
Anisotropic x-ray magnetic linear dichroism at the Fe L2,3 edgesin Fe3O4 (open access)

Anisotropic x-ray magnetic linear dichroism at the Fe L2,3 edgesin Fe3O4

X-ray magnetic linear dichroism at the Fe L{sub 2,3} edges of the ferrimagnet Fe{sub 3}O{sub 4} was found to exhibit a strong dependence on the relative orientation of external magnetic field, x-ray polarization, and crystalline axes. Spectral shape and magnitude of the effect were determined for Fe{sub 3}O{sub 4}(011) and Fe{sub 3}O{sub 4}(001) thin films varying the in-plane orientation of field and polarization. All dichroism spectra can be described as a linear combination of three fundamental spectra which in turn give a good agreement with calculated spectra using atomic multiplet theory. The angular dependence of the magnetic dichroism reflects the crystal field symmetry. It can be used to estimate the crystal field splitting and allows determining the spin quantization axis.
Date: April 30, 2006
Creator: Arenholz, Elke; van der Laan, Gerrit; Chopdekar, Rajesh V. & Suzuki, Yuri
Object Type: Article
System: The UNT Digital Library
Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide (open access)

Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Several pulsed corona discharge (PCD) reactors have been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. Visual observation shows that the corona is not uniform throughout the reactor. The corona is stronger near the top of the reactor in argon, while nitrogen and mixtures of argon or nitrogen with H{sub 2}S produce stronger coronas near the bottom of the reactor. Both of these effects appear to be explainable base on the different electron collision interactions with monatomic versus polyatomic gases. A series of experiments varying reactor operating parameters, including discharge capacitance, pulse frequency, and discharge voltage were performed while maintaining constant power input to the reactor. At constant reactor power input, low capacitance, high pulse frequency, and high voltage operation appear to provide the highest …
Date: September 30, 2006
Creator: Argyle, Morris D.; Ackerman, John F.; Muknahallipatna, Suresh; Hamann, Jerry C.; Legowski, Stanislaw; Zhao, Guibing et al.
Object Type: Report
System: The UNT Digital Library
COST-EFFECTIVE METHOD FOR PRODUCING SELF SUPPORTED PALLADIUM ALLOY MEMBRANES FOR USE IN EFFICIENT PRODUCTION OF COAL DERIVED HYDROGEN (open access)

COST-EFFECTIVE METHOD FOR PRODUCING SELF SUPPORTED PALLADIUM ALLOY MEMBRANES FOR USE IN EFFICIENT PRODUCTION OF COAL DERIVED HYDROGEN

In the past quarter, we have conducted additional characterization and permeation tests on different Pd alloy membranes including PdCuTa ternary alloy materials. We attempted to address some discrepancies between SwRI{reg_sign} and CSM relating to PdCu stoichiometry by preparing a range of PdCu membranes with compositions from {approx}58-65 at% Pd (bal. Cu). While some difficulties in cutting and sealing these thin membranes at CSM continue, some progress has been made in identifying improved membrane support materials. We have also completed an initial cost analysis for large-scale vacuum deposition and fabrication of thin Pd ally membranes and project that the process can meet DOE cost targets. Minimal progress was made in the past quarter relating to the testing of prototype membrane modules at Idatech. In the past quarter Idatech was acquired by a UK investment firm, which we believe may have impacted the ability of key technical personnel to devote sufficient time to support this effort. We are hopeful their work can be completed by the end of the calendar year.
Date: September 30, 2006
Creator: Arps, J. & Coulter, K.
Object Type: Report
System: The UNT Digital Library
Fabrication and Characterization of Suspended Carbon Nanotube Devices in Liquid (open access)

Fabrication and Characterization of Suspended Carbon Nanotube Devices in Liquid

Suspended carbon nanotube devices are a promising platform for future bio-electronic applications. Suspended carbon nanotube transistors have been previously fabricated in air; however all previous attempts to bring them into liquid failed. We analyze forces acting on the suspended nanotube devices during immersion into liquids and during device operation and show that surface tension forces acting on the suspended nanotubes during transfer into the liquid phase are responsible for the nanotube damage. We have developed a new strategy that circumvents these limitations by coating suspended nanotubes with a rigid inorganic shell in the gas phase. The coating reinforces the nanotubes and allows them to survive transfer through the interface. Subsequent removal of the coating in the solution phase restores pristine suspended nanotubes. We demonstrate that devices fabricated using this technique preserve their original electrical characteristics.
Date: October 30, 2006
Creator: Artyukhin, A.; Stadermann, M.; Stroeve, P.; Bakajin, O. & Noy, A.
Object Type: Article
System: The UNT Digital Library
Search for Charmonium States Decaying to J/\psi\gamma \gamma $ Using Initial-State Radiation Events (open access)

Search for Charmonium States Decaying to J/\psi\gamma \gamma $ Using Initial-State Radiation Events

We study the processes e{sup +}e{sup -} {yields} (J/{psi}{gamma}{gamma}){gamma} and e{sup +}e{sup -} {yields} (J/{psi}{pi}{sup -}{pi}{sup +}){gamma} where the hard photon radiated from an initial e{sup +}e{sup -} collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/{psi}{gamma}{gamma} we consider J/{psi}{pi}{sup 0}, J/{psi}{eta}, {chi}{sub c1}{gamma}, and {chi}c{sub 2}{gamma} candidates. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} CM energy in each event, so these data can be compared with direct e{sup +}e{sup -} measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/{psi}{gamma}{gamma} channels in the Y (4260) mass region.
Date: November 30, 2006
Creator: Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Absolute Branching FractionsB to D\pi, D^*\pi, D^{**}\pi with aMissing Mass Method (open access)

Measurement of the Absolute Branching FractionsB to D\pi, D^*\pi, D^{**}\pi with aMissing Mass Method

We present branching fraction measurements of charged and neutral B decays to D{pi}{sup -}, D*{pi}{sup -} and D**{pi}{sup -} with a missing mass method, based on a sample of 231 million {Upsilon}(4S) {yields} B{bar B} pairs collected by the BABAR detector at the PEP-II e{sup +}e{sup -} collider. One of the B mesons is fully reconstructed and the other one decays to a reconstructed charged {pi} and a companion charmed meson identified by its recoil mass, inferred by kinematics. Here D** refers to the sum of all the non-strange charm meson states with masses in the range 2.2-2.8 GeV/c{sup 2}.
Date: November 30, 2006
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Observation of B^+ to Phi Phi K^+ and Evidence for B^0 to Phi Phi K^0 below Eta_C Threshold. (open access)

Observation of B^+ to Phi Phi K^+ and Evidence for B^0 to Phi Phi K^0 below Eta_C Threshold.

The authors report measurements of the decays B{sup +} {yields} {phi}{phi}K{sup +} and B{sup 0} {yields} {phi}{phi}K{sup 0} using a sample of 231 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The branching fractions are measured to be {Beta}(B{sup +} {yields} {phi}{phi}K{sup +}) = (7.5 {+-} 1.0(stat) {+-} 0.7(syst)) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}{phi}K{sup 0}) = (4.1{sub -1.4}{sup +1.7}(stat) {+-} 0.4(syst)) x 10{sup -6} for a {phi}{phi} invariant mass below 2.85 GeV/c{sup 2}.
Date: November 30, 2006
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Trace-level beryllium analysis in the laboratory and in the field: State of the art, challenges, and opportunities (open access)

Trace-level beryllium analysis in the laboratory and in the field: State of the art, challenges, and opportunities

Control of workplace exposure to beryllium is a growing issue in the United States and other nations. As the health risks associated with low-level exposure to beryllium are better understood, the need increases for improved analytical techniques both in the laboratory and in the field. These techniques also require a greater degree of standardization to permit reliable comparison of data obtained from different locations and at different times. Analysis of low-level beryllium samples, in the form of air filters or surface wipes, is frequently required for workplace monitoring or to provide data to support decision-making on implementation of exposure controls. In the United States and the United Kingdom, the current permissible exposure level is 2 {micro}g/m{sup 3} (air), and the United States Department of Energy has implemented an action level of 0.2 {micro}g/m{sup 3} (air) and 0.2 {micro}g/100 cm{sup 2} (surface). These low-level samples present a number of analytical challenges, including (1) a lack of suitable standard reference materials, (2) unknown robustness of sample preparation techniques, (3) interferences during analysis, (4) sensitivity (sufficiently low detection limits), (5) specificity (beryllium speciation), and (6) data comparability among laboratories. Additionally, there is a need for portable, real-time (or near real-time) equipment for beryllium …
Date: March 30, 2006
Creator: BRISSON, MICHAEL
Object Type: Article
System: The UNT Digital Library
CFD Simulation of Flow Tones from Grazing Flow past a Deep Cavity (open access)

CFD Simulation of Flow Tones from Grazing Flow past a Deep Cavity

None
Date: May 30, 2006
Creator: Bagwell, T.
Object Type: Report
System: The UNT Digital Library
Review of An Introduction to Parallel and Vector Scientific Computing (open access)

Review of An Introduction to Parallel and Vector Scientific Computing

On one hand, the field of high-performance scientific computing is thriving beyond measure. Performance of leading-edge systems on scientific calculations, as measured say by the Top500 list, has increased by an astounding factor of 8000 during the 15-year period from 1993 to 2008, which is slightly faster even than Moore's Law. Even more importantly, remarkable advances in numerical algorithms, numerical libraries and parallel programming environments have led to improvements in the scope of what can be computed that are entirely on a par with the advances in computing hardware. And these successes have spread far beyond the confines of large government-operated laboratories, many universities, modest-sized research institutes and private firms now operate clusters that differ only in scale from the behemoth systems at the large-scale facilities. In the wake of these recent successes, researchers from fields that heretofore have not been part of the scientific computing world have been drawn into the arena. For example, at the recent SC07 conference, the exhibit hall, which long has hosted displays from leading computer systems vendors and government laboratories, featured some 70 exhibitors who had not previously participated. In spite of all these exciting developments, and in spite of the clear need to …
Date: June 30, 2006
Creator: Bailey, David H. & Lefton, Lew
Object Type: Report
System: The UNT Digital Library
Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants (open access)

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. Our approach towards immobilizing the potassium salt of the molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the far end of an optical fiber is to embed the cluster in a thermally cured sol-gel matrix particle. Due to the improved mechanical properties of this approach high temperature sensor measurements were performed up to 100 C. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.
Date: September 30, 2006
Creator: Baker, Gregory L.; Ghosh, Ruby N.; Osborn, D. J. & Zhang, Po
Object Type: Report
System: The UNT Digital Library
Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants (open access)

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications has been developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. We report on a fiber optic technique for detection of gas phase oxygen up to 100 C based on the {sup 3}O{sub 2} quenching of the luminescence from molybdenum chloride clusters, K{sub 2}Mo{sub 6}Cl{sub 14}. The inorganic sensing film is a composite of sol-gel particles embedded in a thin, oxygen permeable sol-gel binder. The particles are comprised of thermally stable, luminescent K{sub 2}Mo{sub 6}Cl{sub 14} clusters dispersed in a fully equilibrated sol-gel matrix. From 40 to 100 C, the fiber sensor switches {approx}6x in intensity in response to alternating pulses of <0.001% O2 and 21% O{sub 2} between two well defined levels with a response time of 10 s. The sensor signal is a few nW for an input pump power of 250 {micro}W. The normalized sensor signal is linear with molar oxygen concentration and fits the theoretical Stern-Volmer relationship. Although the sensitivity decreases with temperature, sensitivity at 100 C is 160 [O{sub 2}]{sup -1}. These parameters are well suited for …
Date: September 30, 2006
Creator: Baker, Gregory L.; Ghosh, Ruby N.; Osborn, D. J. & Zhang, Po
Object Type: Report
System: The UNT Digital Library
Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants (open access)

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. Our approach towards immobilizing the potassium salt of the molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the far end of an optical fiber is to embed the cluster in a thermally cured sol-gel matrix particle. This particle-in-binder approach affords fibers with greatly improved mechanical properties, as compared to previous approaches. The sensor was characterized in 2-21% gas phase oxygen at 40, 70 and 100 C. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.
Date: June 30, 2006
Creator: Baker, Gregory L.; Ghosh, Ruby N.; Osborn, D.J. & Zhang, Po
Object Type: Report
System: The UNT Digital Library
Oxygen Transport Ceramic Membranes (open access)

Oxygen Transport Ceramic Membranes

None
Date: September 30, 2006
Creator: Bandopadhyay, S. & Nithyanantham, T.
Object Type: Report
System: The UNT Digital Library
Oxygen Transport Ceramic Membranes (open access)

Oxygen Transport Ceramic Membranes

A non-agglomerated and nanocrystalline-sized powder was successfully produced using ethylene glycol nitrate methods. The LSFT powder prepared using this method exhibits well dispersed and nano-sized particles about 100-200 nm. The density of LSFT sintered at 1300 C was about 90% of the theoretical density at which is 100 C less than that of the previous LSFT which was sintered at 1400 C. The sample sintered at 1400 C exhibited the evidence of a liquid phase at the grain boundaries and 2nd phase formation which probably caused low mechanical stability. The electrical conductivity and Seebeck coefficient were measured as a function of temperature. The LSFT-CGO specimens were cut from the as sintered bars and used for the evaluation of Mechanical Properties after polishing. The effect of strain rate on the flexural strength of the LSFT-CGO test specimens was studied. Three strain rates 6, 60 and 600 {micro}m/ min were chosen for this study. It is observed from the results that with increasing cross head speed the membrane takes higher loads to fail. A reduction in the strength of the membrane was observed at 1000 C in N{sub 2}. Two different routes were investigated to synthesis GDC using either formate or carbonate …
Date: June 30, 2006
Creator: Bandopadhyay, S. & Nithyanantham, T.
Object Type: Report
System: The UNT Digital Library
High-Temperature High-Power Packaging Techniques for HEV Traction Applications (open access)

High-Temperature High-Power Packaging Techniques for HEV Traction Applications

A key issue associated with the wider adoption of hybrid-electric vehicles (HEV) and plug in hybrid-electric vehicles (PHEV) is the implementation of the power electronic systems that are required in these products [1]. To date, many consumers find the adoption of these technologies problematic based on a financial analysis of the initial cost versus the savings available from reduced fuel consumption. Therefore, one of the primary industry goals is the reduction in the price of these vehicles relative to the cost of traditional gasoline powered vehicles. Part of this cost reduction must come through optimization of the power electronics required by these vehicles. In addition, the efficiency of the systems must be optimized in order to provide the greatest range possible. For some drivers, any reduction in the range associated with a potential HEV or PHEV solution in comparison to a gasoline powered vehicle represents a significant barrier to adoption and the efficiency of the power electronics plays an important role in this range. Likewise, high efficiencies are also important since lost power further complicates the thermal management of these systems. Reliability is also an important concern since most drivers have a high level of comfort with gasoline powered vehicles …
Date: November 30, 2006
Creator: Barlow, F.D. & Elshabini, A.
Object Type: Report
System: The UNT Digital Library