States

Mask defect verification using actinic inspection and defect mitigation technology (open access)

Mask defect verification using actinic inspection and defect mitigation technology

The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. The successful production of defect-free masks will depend on the timely development of defect inspection tools, including both mask blank inspection tools and absorber pattern inspection tools to meet the 22 nm half-pitch node. EUV mask blanks with embedded phase defects were inspected with a reticle actinic inspection tool (AIT) and the Lasertec M7360. The Lasertec M7360 is operated at SEMA TECH's Mask blank Development Center (MBDC) in Albany, with sensitivity to multilayer defects down to 40-45 nm, which is not likely sufficient for mask blank development below the 32 nm half-pitch node. Phase defect printability was simulated to calculate the required defect sensitivity for the next generation blank inspection tool to support reticle development for the sub-32 nm half-pitch technology node. This paper will also discuss the kind of infrastructure that will be required in the development and mass production stages.
Date: April 14, 2009
Creator: Huh, Sungmin; Kearney, Patrick; Wurm, Stefan; Goodwin, Frank; Goldberg, Kenneth; Mochi, Iacopo et al.
Object Type: Article
System: The UNT Digital Library
STANFORD IN-SITU HIGH RATE YBCO PROCESS: TRANSFER TO METAL TAPES AND PROCESS SCALE UP (open access)

STANFORD IN-SITU HIGH RATE YBCO PROCESS: TRANSFER TO METAL TAPES AND PROCESS SCALE UP

Executive Summary The materials science understanding of high rate low cost processes for Coated Conductor will benefit the application to power utilities for low loss energy transportation and power generation as well for DOD applications. The research in this program investigated several materials processing approaches that are new and original, and are not being investigated elsewhere. This work added to the understanding of the material science of high rate PVD growth of HTSC YBCO assisted by a liquid phase. A new process discovered uses amorphous glassy precursors which can be made at high rate under flexible conditions of temperature and oxygen, and later brought to conditions of oxygen partial pressure and temperature for rapid conversion to YBCO superconductor. Good critical current densities were found, but further effort is needed to optimize the vortex pinning using known artificial inclusions. A new discovery of the physics and materials science of vortex pinning in the HTSC system using Sm in place of Y came at growth at unusually low oxygen pressure resulting in clusters of a low or non superconducting phase within the nominal high temperature phase. The driving force for this during growth is new physics, perhaps due to the low oxygen. …
Date: April 14, 2009
Creator: Beasley, Malcolm R. & H.Hammond, Robert
Object Type: Report
System: The UNT Digital Library
Final Report: Interphase Analysis and Control in Fiber Reinforced Thermoplastic Composites (open access)

Final Report: Interphase Analysis and Control in Fiber Reinforced Thermoplastic Composites

This research program builds upon a multi-disciplinary effort in interphase analysis and control in thermoplastic matrix polymer matrix composites (PMC). The research investigates model systems deemed of interest by members of the Automotive Composites Consortium (ACC) as well as samples at the forefront of PMC process development (DRIFT and P4 technologies). Finally, the research investigates, based upon the fundamental understanding of the interphases created during the fabrication of thermoplastic PMCs, the role the interphase play in key bulk properties of interest to the automotive industry.
Date: March 14, 2009
Creator: Kellar, Jon J.; Cross, William M. & Kjerengtroen, Lidvin
Object Type: Report
System: The UNT Digital Library
Transcriptome and Biochemical Analyses of Fungal Degradation of Wood (open access)

Transcriptome and Biochemical Analyses of Fungal Degradation of Wood

Lignocellulosic accounts for a large percentage of material that can be utilized for biofuels. The most costly part of lignocellulosic material processing is the initial hydrolysis of the wood which is needed to circumvent the lignin barrier and the crystallinity of cellulose. Enzymes will play an increased role in this conversion in that they potentially provide an alternative to costly and caustic high temperature and acid treatment. The increasing use of enzymes in biotechnology is facilitated by both continued improvements in enzyme technology but also in the discovery of new and novel enzymes. The present proposal is aimed at identifying the enzymes which are known to depolymerize woody biomass. Fundamental understanding of how nature gains access to cellulose and hemicellulose will impact all applications. Because fungi are the only known microbes capable of circumventing the lignin barrier, knowledge of the enzyme they use is of great potential for biofuel processing. Nature has evolved different fungal mechanisms for enzymatic hydrolysis of wood. Most notable are the white-rot fungi (wrf) and the brown-rot fungi (brf). This proposed research aims at determining the complete transcriptome of three wrf and two brf to determine the enzymes involved in lignocellulose degradation. The transcriptome work will …
Date: March 14, 2009
Creator: Tien, Ming
Object Type: Report
System: The UNT Digital Library
Gasificaton Transport: A Multiphase CFD Approach & Measurements (open access)

Gasificaton Transport: A Multiphase CFD Approach & Measurements

The objective of this project was to develop predictive theories for the dispersion and mass transfer coefficients and to measure them in the turbulent fluidization regime, using existing facilities. A second objective was to use our multiphase CFD tools to suggest optimized gasifier designs consistent with aims of Future Gen. We have shown that the kinetic theory based CFD codes correctly compute: (1) Dispersion coefficients; and (2) Mass transfer coefficients. Hence, the kinetic theory based CFD codes can be used for fluidized bed reactor design without any such inputs. We have also suggested a new energy efficient method of gasifying coal and producing electricity using a molten carbonate fuel cell. The principal product of this new scheme is carbon dioxide which can be converted into useful products such as marble, as is done very slowly in nature. We believe this scheme is a lot better than the canceled FutureGen, since the carbon dioxide is safely sequestered.
Date: February 14, 2009
Creator: Gidaspow, Dimitri; Jiradilok, Veeraya; Kashyap, Mayank & Chalermsinsuwan, Benjapon
Object Type: Report
System: The UNT Digital Library
DOWNSTREAM IMPACTS OF SLUDGE MASS REDUCTION VIA ALUMINUM DISSOLUTION ON DWPF PROCESSING OF SAVANNAH RIVER SITE HIGH LEVEL WASTE - 9382 (open access)

DOWNSTREAM IMPACTS OF SLUDGE MASS REDUCTION VIA ALUMINUM DISSOLUTION ON DWPF PROCESSING OF SAVANNAH RIVER SITE HIGH LEVEL WASTE - 9382

The SRS sludge that was to become a major fraction of Sludge Batch 5 (SB5) for the Defense Waste Processing Facility (DWPF) contained a large fraction of H-Modified PUREX (HM) sludge, containing a large fraction of aluminum compounds that could adversely impact the processing and increase the vitrified waste volume. It is beneficial to reduce the non-radioactive fraction of the sludge to minimize the number of glass waste canisters that must be sent to a Federal Repository. Removal of aluminum compounds, such as boehmite and gibbsite, from sludge can be performed with the addition of NaOH solution and heating the sludge for several days. Preparation of SB5 involved adding sodium hydroxide directly to the waste tank and heating the contents to a moderate temperature through slurry pump operation to remove a fraction of this aluminum. The Savannah River National Laboratory (SRNL) was tasked with demonstrating this process on actual tank waste sludge in our Shielded Cells Facility. This paper evaluates some of the impacts of aluminum dissolution on sludge washing and DWPF processing by comparing sludge processing with and without aluminum dissolution. It was necessary to demonstrate these steps to ensure that the aluminum removal process would not adversely impact …
Date: January 14, 2009
Creator: Pareizs, J; Cj Bannochie, C; Michael Hay, M & Daniel McCabe, D
Object Type: Article
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT BUCKLING EVALUATION METHODS AND RESULTS FOR THE PRIMARY TANKS (open access)

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT BUCKLING EVALUATION METHODS AND RESULTS FOR THE PRIMARY TANKS

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive anchor bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank …
Date: January 14, 2009
Creator: TC, MACKEY; KI, JOHNSON; JE, DEIBLER; SP, PILLI; MW, RINKER & NK, KARRI
Object Type: Report
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT INCREASED LIQUID LEVEL ANALYSIS FOR 241-AP TANK FARMS (open access)

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT INCREASED LIQUID LEVEL ANALYSIS FOR 241-AP TANK FARMS

The essential difference between Revision 1 and the original issue of this report is the analysis of the anchor bolts that tie the steel dome of the primary tank to the concrete tank dome. The reevaluation of the AP anchor bolts showed that (for a given temperature increase) the anchor shear load distribution did not change significantly from the initially higher stiffness to the new secant shear stiffness. Therefore, the forces and displacements of the other tank components such as the primary tanks stresses, secondary liner strains, and concrete tank forces and moments also did not change significantly. Consequently, the revised work in Revision 1 focused on the changes in the anchor bolt responses and a full reevaluation of all tank components was judged to be unnecessary.
Date: January 14, 2009
Creator: Mackey, T. C.; Deibler, J. E.; Rinker, M. W.; Johnson, K. I.; Pilli, S. P.; Karri, N. K. et al.
Object Type: Report
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SEISMIC ANALYSIS IN SUPPORT OF INCREASED LIQUID LEVEL IN 241-AP TANK FARMS (open access)

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SEISMIC ANALYSIS IN SUPPORT OF INCREASED LIQUID LEVEL IN 241-AP TANK FARMS

The essential difference between Revision 1 and the original issue of this report is in the spring constants used to model the anchor bolt response for the anchor bolts that tie the steel dome of the primary tank to the concrete tank dome. Consequently, focus was placed on the changes in the anchor bolt responses, and a full reevaluation of all tank components was judged to be unnecessary. To confirm this judgement, primary tank stresses from the revised analysis of the BES-BEC case are compared to the original analysis and it was verified that the changes are small, as expected.
Date: January 14, 2009
Creator: Mackey, T. C.; Abatt, F. G. & Rinker, M. W.
Object Type: Report
System: The UNT Digital Library
Highly 15N-Enriched Chondritic Clasts in the Isheyevo Meteorite (open access)

Highly 15N-Enriched Chondritic Clasts in the Isheyevo Meteorite

The metal-rich carbonaceous chondrites (CB and CH) have the highest whole-rock {sup 15}N enrichment ({delta}{sup 15}N up to +1500{per_thousand}), similar to {delta}{sup 15}N values reported in micron-sized regions (hotspots) of Interplanetary Dust Particles (IDPs) of possibly cometary origin and fine-grained matrices of unmetamorphosed chondrites. These {sup 15}N-rich hotspots are commonly attributed to low-temperature ion-molecule reactions in the protosolar molecular cloud or in the outer part of the protoplanetary disk. The nature of the whole-rock {sup 15}N enrichment of the metal-rich chondrites is not understood. We report a discovery of a unique type of primitive chondritic clasts in the CH/CB-like meteorite Isheyevo, which provides important constraints on the origin of {sup 15}N anomaly in metal-rich chondrites and nitrogen-isotope fractionation in the Solar System. These clasts contain tiny chondrules and refractory inclusions (5-15 {micro}m in size), and abundant ferromagnesian chondrule fragments (1-50 {micro}m in size) embedded in the partly hydrated, fine-grained matrix material composed of olivines, pyroxenes, poorly-organized aromatic organics, phyllosilicates and other hydrous phases. The mineralogy and oxygen isotope compositions of chondrules and refractory inclusions in the clasts are similar to those in the Isheyevo host, suggesting formation at similar heliocentric distances. In contrast to the previously known extraterrestrial samples, the …
Date: January 14, 2009
Creator: Bonal, L; Huss, G R; Krot, A N; Nagashima, K; Ishii, H A; Bradley, J P et al.
Object Type: Article
System: The UNT Digital Library
Progress Report and Technical Evaluation of the Iscr Pilot Test Conducted at the Former CCC/Usda Grain Storage Facility in Centralia, Kansas. (open access)

Progress Report and Technical Evaluation of the Iscr Pilot Test Conducted at the Former CCC/Usda Grain Storage Facility in Centralia, Kansas.

In October, 2007, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) presented the document Interim Measure Conceptual Design (Argonne 2007a) to the Kansas Department of Health and Environment, Bureau of Environmental Remediation (KDHE/BER), for a proposed non-emergency Interim Measure (IM) at the site of the former CCC/USDA grain storage facility in Centralia, Kansas (Figure 1.1). The IM was recommended to mitigate existing levels of carbon tetrachloride contamination identified in the vadose zone soils beneath the former facility and in the groundwater beneath and in the vicinity of the former facility, as well as to moderate or decrease the potential future concentrations of carbon tetrachloride in the groundwater. The Interim Measure Conceptual Design (Argonne 2007a) was developed in accordance with the KDHE/BER Policy No.BERRS-029, Policy and Scope of Work: Interim Measures (KDHE 1996). The hydrogeologic, geochemical, and contaminant distribution characteristics of the Centralia site, as identified by the CCC/USDA, factored into the development of the nonemergency IM proposal. These characteristics were summarized in the Interim Measure Conceptual Design (Argonne 2007a) and were discussed in detail in previous Argonne reports (Argonne 2002a, 2003, 2004, 2005a,b,c, 2006a,b, 2007b). The identified remedial goals of the proposed IM were as follows: (1) …
Date: January 14, 2009
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Record of Technical Change for Corrective Action Plan for Corrective Action Unit 139 (open access)

Record of Technical Change for Corrective Action Plan for Corrective Action Unit 139

None
Date: January 14, 2009
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Sensor Development and Readout Prototyping for the STAR Pixel Detector (open access)

Sensor Development and Readout Prototyping for the STAR Pixel Detector

The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) is designing a new vertex detector. The purpose of this upgrade detector is to provide high resolution pointing to allow for the direct topological reconstruction of heavy flavor decays such as the D{sup 0} by finding vertices displaced from the collision vertex by greater than 60 microns. We are using Monolithic Active Pixel Sensor (MAPS) as the sensor technology and have a coupled sensor development and readout system plan that leads to a final detector with a <200 {micro}s integration time, 400 M pixels and a coverage of -1 < {eta} < 1. We present our coupled sensor and readout development plan and the status of the prototyping work that has been accomplished.
Date: January 14, 2009
Creator: Greiner, L.; Anderssen, E.; Matis, H. S.; Ritter, H. G.; Stezelberger, T.; Szelezniak, M. et al.
Object Type: Article
System: The UNT Digital Library
Structure and Electrochemistry of LiNi1/3Co1/3-yMyMn1/3O2 (M=Ti, Al, Fe) Positive Electrode Materials (open access)

Structure and Electrochemistry of LiNi1/3Co1/3-yMyMn1/3O2 (M=Ti, Al, Fe) Positive Electrode Materials

A series of materials based on the LiNi1/3Co1/3-yMyMn1/3O2 (M = Ti,Al,Fe) system has been synthesized and examined structurally and electrochemically. It is found that the changes in electrochemical performance depend highly on the nature of the substituting atom and its effect on the crystal structure. Substitution with small amounts of Ti4+ (y = 1/12) leads to the formation of a high-capacity and high-rate positive electrode material. Iron substituted materials suffer from an increased antisite defect concentration and exhibit lower capacities and poor rate capabilities. Single-phase materials are found for LiNi1/3Co1/3-yAlyMn1/3O2 when y<_ 1/4 and all exhibit decreased capacities when cycled to 4.3 V. However, an increase in rate performance and cycle stability upon aluminum substitution is correlated with an improved lamellar structure.
Date: January 14, 2009
Creator: Wilcox, James; Patoux, Sebastien & Doeff, Marca
Object Type: Article
System: The UNT Digital Library
Theoretical Overview on Recent Developments in Transverse Spin Physics (open access)

Theoretical Overview on Recent Developments in Transverse Spin Physics

Transverse-spin physics has been very active and rapidly developing in the last few years. In this talk, I will briefly summarize recent theoretical developments, focusing on the associated QCD dynamics in transverse spin physics.
Date: January 14, 2009
Creator: Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Solid-State Lighting on a Shoestring Budget: The Economics of Off-Grid Lighting for Small Businesses in Kenya (open access)

Solid-State Lighting on a Shoestring Budget: The Economics of Off-Grid Lighting for Small Businesses in Kenya

superior lighting services to low income people in off-grid areas of developing countries, many of whom currently rely on fuel based lighting sources such as kerosene. If this potential is to be achieved in the near term, however, manufacturers must produce off-grid lighting products that are inexpensive, perform well, and meet the needs of potential end users. At present, relatively few products meet all three of these goals. In this article, we report results from a detailed study of lighting use by micro-enterprises in two small towns in Kenya's Rift Valley Province. The work included a survey about lighting use by 50 small businesses, careful measurements of kerosene lighting use patterns and associated costs for 23 of these businesses, and a subsequent field trial in which 14 of the 23 businesses purchased and used low cost LED lamps over a number of months.
Date: December 14, 2008
Creator: Radecsky, Kristen; Johnstone, Peter; Jacobson, Arne & Mills, Evan
Object Type: Report
System: The UNT Digital Library
Accelerating scientific discovery : 2007 annual report. (open access)

Accelerating scientific discovery : 2007 annual report.

As a gateway for scientific discovery, the Argonne Leadership Computing Facility (ALCF) works hand in hand with the world's best computational scientists to advance research in a diverse span of scientific domains, ranging from chemistry, applied mathematics, and materials science to engineering physics and life sciences. Sponsored by the U.S. Department of Energy's (DOE) Office of Science, researchers are using the IBM Blue Gene/L supercomputer at the ALCF to study and explore key scientific problems that underlie important challenges facing our society. For instance, a research team at the University of California-San Diego/ SDSC is studying the molecular basis of Parkinson's disease. The researchers plan to use the knowledge they gain to discover new drugs to treat the disease and to identify risk factors for other diseases that are equally prevalent. Likewise, scientists from Pratt & Whitney are using the Blue Gene to understand the complex processes within aircraft engines. Expanding our understanding of jet engine combustors is the secret to improved fuel efficiency and reduced emissions. Lessons learned from the scientific simulations of jet engine combustors have already led Pratt & Whitney to newer designs with unprecedented reductions in emissions, noise, and cost of ownership. ALCF staff members provide …
Date: November 14, 2008
Creator: Beckman, P.; Dave, P. & Drugan, C.
Object Type: Report
System: The UNT Digital Library
Accessing tri-gluon correlations in the nucleon via the singlespin asymmetry in open charm production (open access)

Accessing tri-gluon correlations in the nucleon via the singlespin asymmetry in open charm production

We calculate the single transverse-spin asymmetry for open charm production in pp collisions within the QCD collinear factorization approach. We include contributions from both twist-three quark-gluon and tri-gluon correlation functions. We find that the quark-gluon correlation functions alone generate only a very small asymmetry for open charm production in the kinematic region of current interest at RHIC, so that the observation of any significant single-spin asymmetry would be a clear indication of the presence of tri-gluon correlations inside a polarized proton. We furthermore demonstrate that the tri-gluon contribution could be very different for the production of D and \bar{D} mesons. These features make the single spin asymmetry in open charm production in polarized pp collisions at RHIC an excellent probe of tri-gluon correlation functions.
Date: November 14, 2008
Creator: Kang, Zhong-Bo; Qiu, Jian-Wei; Vogelsang, Werner & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Analysis of Cost-Effective Off-Board Hydrogen Storage and Refueling Stations (open access)

Analysis of Cost-Effective Off-Board Hydrogen Storage and Refueling Stations

This report highlights design and component selection considerations for compressed gas hydrogen fueling stations operating at 5000 psig or 350 bar. The primary focus is on options for compression and storage – in terms of practical equipment options as well as various system configurations and how they influence delivery performance and station economics.
Date: November 14, 2008
Creator: Barnes, Ted & Liss, William
Object Type: Report
System: The UNT Digital Library
Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials (open access)

Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials

In an extension of the Associated Particle Imaging technique that is used for the detection and imaging of hidden explosives, the present measurements use a beam of tagged 14.1 MeV neutrons in coincidence with two or more gammas to probe for the presence of fissionable materials. We have measured neutron-gamma-gamma coincidences with targets of depleted uranium, tungsten, lead, iron, and carbon and will present results that show the multiple-coincidence counting rate for the depleted uranium is substantially higher than any of the non-fissionable materials. In addition, the presence of coincidences involving delayed particle spectra provides a signature for fissionable materials that is distinct from that for non-fissionable ones. Information from the tagged neutron involved in the coincidence event is used to compute the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is compact and portable, and produces relatively low levels of background radiation. Simultaneous measurements on packages of interest for both explosives and fissionable materials are now feasible.
Date: November 14, 2008
Creator: Tinsley, J.R., Hurley, J.P., Trainham, R., Keegan, R.P.
Object Type: Article
System: The UNT Digital Library
Performance Contracting and Energy Efficiency in the State Government Market (open access)

Performance Contracting and Energy Efficiency in the State Government Market

There is growing interest in energy efficiency (EE) among state policymakers as a result of increasing environmental concerns, rising electricity and natural gas prices, and lean economic times that motivate states to look more aggressively for cost-saving opportunities in public sector buildings. One logical place for state policymakers to demonstrate their commitment to energy efficiency is to 'lead by example' by developing and implementing strategies to reduce the energy consumption of state government facilities through investments in energy efficient technologies. Traditionally, energy efficiency improvements at state government facilities are viewed as a subset in the general category of building maintenance and construction. These projects are typically funded through direct appropriations. However, energy efficiency projects are often delayed or reduced in scope whereby not all cost-effective measures are implemented because many states have tight capital budgets. Energy Savings Performance Contracting (ESPC) offers a potentially useful strategy for state program and facility managers to proactively finance and develop energy efficiency projects. In an ESPC project, Energy Service Companies (ESCOs) typically guarantee that the energy and cost savings produced by the project will equal or exceed all costs associated with implementing the project over the term of the contract. ESCOs typically provide turnkey …
Date: November 14, 2008
Creator: Bharvirkar, Ranjit; Goldman, Charles; Gilligan, Donald; Singer, Terry E.; Birr, David; Donahue, Patricia et al.
Object Type: Report
System: The UNT Digital Library
Problem Proposed for the American Mathematical Monthly (open access)

Problem Proposed for the American Mathematical Monthly

The problem is to define: P(x) := {Sigma}{sub k = 1}{sup {infinity}} arctan (x - 1/(k + x + 1) {radical}(k + 1) + (k + 2) {radical}(k + x)). (1) (a) Find explicit, finite-expression evaluations of P(n) for all integers n {ge} 0. (b) Show {tau} := lim{sub x {yields} -1{sup +}} P(x) exists, and find an explicit evaluation for {tau}. (c) Are there a more general closed forms for P, say at half-integers? Solution with the abbreviations: r := {radical} (k + 1), s := {radical} (k + x) the argument of arctan in (1) becomes s{sup 2} - r{sup 2}/(s{sup 2} + 1) r + (r{sup 2} + 1) s = s - r/r s + 1 = 1/r - 1/s / 1 + 1/r 1/s.
Date: November 14, 2008
Creator: Bailey, David H.; Borwein, Jonathan M. & Waldvogel, Jorg
Object Type: Article
System: The UNT Digital Library
Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules (open access)

Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules

This research program was designed to enhance our understanding of the behavior of fluids and fluid mixtures containing chain-like molecules. The original objective was to explain and predict the experimentally observed thermophysical properties, including phase equilibria and dynamics, of systems containing long flexible molecules ranging in length from alkanes to polymers. Over the years the objectives were expanded to include the treatment of molecules that were not chain-like. Molecular dynamics and Monte Carlo computer simulations were used to investigate how variations in molecular size, shape and architecture influence the types of phase equilibria, thermodynamic properties, structure and surface interactions that are observed experimentally. The molecular insights and theories resulting from this program could eventually serve as the foundation upon which to build correlations of the properties of fluids that are both directly and indirectly related to the Nation’s energy resources including: petroleum, natural gas, and polymer solutions, melts, blends, and materials.
Date: November 14, 2008
Creator: Hall, Carol K.
Object Type: Report
System: The UNT Digital Library
3-D Microprobe Metrology (open access)

3-D Microprobe Metrology

This report documents the results of a project undertaken to develop an ultra-high-accuracy measurement capability, which is necessary to address a rising trend toward miniaturized mechanical products exhibiting dramatically reduced product tolerances. A significant improvement in measurement capability is therefore required to insure that a 4:1 ratio can be maintained between product tolerances and measurement uncertainty.
Date: October 14, 2008
Creator: Swallow, Kevin
Object Type: Report
System: The UNT Digital Library