Dimensional errors in LIGA-produced metal structures due to thermal expansion and swelling of PMMA. (open access)

Dimensional errors in LIGA-produced metal structures due to thermal expansion and swelling of PMMA.

Numerical methods are used to examine dimensional errors in metal structures microfabricated by the LIGA process. These errors result from elastic displacements of the PMMA mold during electrodeposition and arise from thermal expansion of the PMMA when electroforming is performed at elevated temperatures and from PMMA swelling due to absorption of water from aqueous electrolytes. Both numerical solutions and simple analytical approximations describing PMMA displacements for idealized linear and axisymmetric geometries are presented and discussed. We find that such displacements result in tapered metal structures having sidewall slopes up to 14 {micro}m per millimeter of height for linear structures bounded by large areas of PMMA. Tapers for curved structures are of similar magnitude, but these structures are additionally skewed from the vertical. Potential remedies for reducing dimensional errors are also discussed. Here we find that auxiliary moat-like features patterned into the PMMA surrounding mold cavities can reduce taper by an order of magnitude or more. Such moats dramatically reduce tapers for all structures, but increase skew for curved structures when the radius of curvature is comparable to the structure height.
Date: April 1, 2004
Creator: Kistler, Bruce L.; Dryden, Andrew S.; Crowell, Jeffrey A.W. & Griffiths, Stewart K.
Object Type: Report
System: The UNT Digital Library
History and testimony of competency-based development at Sandia National Laboratories. (open access)

History and testimony of competency-based development at Sandia National Laboratories.

More than ten years ago, Sandia managers defined a set of traits and characteristics that were needed for success at Sandia. Today, the Sandia National Laboratories Success Profile Competencies continue to be powerful tools for employee and leadership development. The purpose of this report is to revisit the historical events that led to the creation and adaptation of the competencies and to position them for integration in future employee selection, development, and succession planning processes. This report contains an account of how the competencies were developed, testimonies of how they are used within the organization, and a description of how they will be foundational elements of new processes.
Date: April 1, 2004
Creator: Burt, Rebecca A. & Narahara, Sheryl K.
Object Type: Report
System: The UNT Digital Library
Tonopah Test Range Post-Closure Inspection Annual Report, Tonopah Test Range, Nevada, Calendar Year 2003 (open access)

Tonopah Test Range Post-Closure Inspection Annual Report, Tonopah Test Range, Nevada, Calendar Year 2003

This post-closure inspection report provides documentation of the semiannual inspection activities, maintenance and repair activities, and conclusions and recommendations for calendar year 2003 for eight corrective action units located on the Tonopah Test Range, Nevada.
Date: April 1, 2004
Creator: United States. National Nuclear Security Administration. Nevada Site Office.
Object Type: Report
System: The UNT Digital Library
Large batch dimensional metrology demonstrated in the example of a LIGA fabricated spring. (open access)

Large batch dimensional metrology demonstrated in the example of a LIGA fabricated spring.

Deep x-ray lithography in combination with electroforming is capable of producing high precision metal parts in small lot series. This study deals with a high aspect ratio structure with overall dimensions on the order of 10 mm x 7 mm x 1.5 mm, with the smallest line width being 150 {micro}m. The lateral deviation from the design is to be kept to a minimum, preferably below 5 {micro}m. To ensure adequate quality control, a semi-automated metrology technique has been established to measure all parts. While the paper will give a brief overview of all involved techniques, it focuses on the method to measure the top and bottom of the parts and the top of geometries following the process. The instrument used is a View Engineering Voyager V6x12 microscope, which is fully programmable. The microscope allows direct measurement of geometries but also is capable of saving all captured data as point clouds. These point clouds play a central role when evaluating part geometry. After measuring the part, the point cloud is compared to the computer aided design (CAD) contour of the part, using a commercially available software package. The challenge of proper edge lighting on a nickel alloy part is evaluated …
Date: April 1, 2004
Creator: Aigeldinger, Georg; Skala, Dawn M. & Ceremuga, Joseph T.
Object Type: Report
System: The UNT Digital Library

2004 DOE Hydrogen, Fuel Cells & Infrastructure Technologies Program Review Presentation COST AND PERFORMANCE ENHANCEMENTS FOR A PEM FUEL CELL TURBOCOMPRESSOR

The objective is to assist the Department of Energy in the development of a low cost, reliable and high performance air compressor/expander. Technical Objective 1: Perform a turbocompressor systems PEM fuel cell trade study to determine the enhanced turbocompressor approach. Technical Objective 2: Using the results from technical objective 1, an enhanced turbocompressor will be fabricated. The design may be modified to match the flow requirements of a selected fuel cell system developer. Technical Objective 3: Design a cost and performance enhanced compact motor and motor controller. Technical Objective 4: Turbocompressor/motor controller development.
Date: April 1, 2004
Creator: Gee, Mark K.
Object Type: Presentation
System: The UNT Digital Library
X-Ray Line Measurements with High Efficiency Bragg Crystals (open access)

X-Ray Line Measurements with High Efficiency Bragg Crystals

We have studied the focusing properties of two highly oriented pyrolitic graphite (HOPG) spectrometers, which differ in the degree of the mosaic spread: ZYA with a low mosaic spread ({gamma}=0.4 degrees) and ZYH with a large mosaic spread ({gamma}=3.5 degrees). In order to assess the crystal performance for a variety of different experiments, various K{alpha} and K{beta} x-ray lines have been produced using a high-intensity ({approx}>10{sup 17} W/cm{sup 2}) short-pulse ({approx} 100 fs) laser beam focused onto Ti, V, Zn, and Cu foils. The measured spectral resolution of the HOPG crystals in both first and second order diffraction has been compared with theoretical predictions. Using known values for the peak reflectivity of HOPG crystals, we have also computed K{alpha} x-ray conversion efficiencies of Ti, V, Zn, and Cu. These results are important to estimate the optimal conditions under which different types of HOPG monochromators can be used for the detection of weak x-ray signals as the one encountered in x-ray Thomson/Compton scattering experiments.
Date: April 1, 2004
Creator: Pak, A; Gregori, G; Knight, J; Campbell, K; Landen, O & Glenzer, S
Object Type: Article
System: The UNT Digital Library
A Measurement of the Top Quark Mass with the D0 Detector at s**(1/2) = 1.96-TeV using the Matrix Element Method (open access)

A Measurement of the Top Quark Mass with the D0 Detector at s**(1/2) = 1.96-TeV using the Matrix Element Method

Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.
Date: April 1, 2004
Creator: Kroeninger, Kevin Alexander
Object Type: Report
System: The UNT Digital Library
From Minnesota to New Mexico, E85 Expands beyond the Corn Belt; State Energy Program (SEP) Case Studies (open access)

From Minnesota to New Mexico, E85 Expands beyond the Corn Belt; State Energy Program (SEP) Case Studies

DOE's State Energy Program published this case study in conjunction with the New Mexico Division of Energy Conservation and Management. It describes an emerging corridor of service stations selling a specific alternative fuel-E85 ethanol-along highways in New Mexico.
Date: April 1, 2004
Creator: unknown
Object Type: Text
System: The UNT Digital Library
The Production Cross Sections of the Weak Vector Bosons in Proton Antiproton Collisions at s**(1/2) = 1.96-TeV and a Measurement of the W Boson Decay Width (open access)

The Production Cross Sections of the Weak Vector Bosons in Proton Antiproton Collisions at s**(1/2) = 1.96-TeV and a Measurement of the W Boson Decay Width

The theory that describes the fundamental particle interactions is called the Standard Model, which is a gauge field theory that comprises the Glashow-Weinberg-Salam model [1, 2, 3] of the weak and electromagnetic interactions and quantum chromodynamics (QCD) [4, 5, 6], the theory of the strong interactions. The discovery of the W [7, 8] and Z [9, 10] bosons in 1983 by the UA1 and UA2 collaborations at the CERN p{bar p} collider provided a direct confirmation of the unification of the weak and electromagnetic interactions. Since then, many experiments have refined our understanding of the characteristics of the W and Z bosons.
Date: April 1, 2004
Creator: Varganov, Alexei Valerievich
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Implementation of Frictional Contact Conditions in Surface to Surface, Mortar Based Computational Frameworks (open access)

Implementation of Frictional Contact Conditions in Surface to Surface, Mortar Based Computational Frameworks

A number of recent works have established the mortar technique as an accurate and robust spatial discretization method for contact problems in computational solid mechanics. Since methods based on this idea rely on an integral, non-local representation of the contact operators, their formulation is somewhat more involved than is true for more traditional ''point to surface'' contact algorithms; in particular, the integral projections have nontrivial linearizations in the fully large deformation context. In this work, we concentrate on another aspect of formulations of this type--definition and implementation of frictional contact operators within the mortar contact framework. Issues associated with frame indifference of frictional tractions and kinematics are discussed, and a numerical demonstration of the technique is given.
Date: April 1, 2004
Creator: Laursen, T. A.; Yang, B. & Puso, M. A.
Object Type: Article
System: The UNT Digital Library
A 3D Frictional Segment-to-Segment Contact Method for Large Deformations and Quadratic Elements (open access)

A 3D Frictional Segment-to-Segment Contact Method for Large Deformations and Quadratic Elements

Node-on-segment contact is the most common form of contact used today but has many deficiencies ranging from potential locking to non-smooth behavior with large sliding. Furthermore, node-on-segment approaches are not at all applicable to higher order discretizations (e.g. quadratic elements). In a previous work, [3, 4] we developed a segment-to-segment contact approach for eight node hexahedral elements based on the mortar method that was applicable to large deformation mechanics. The approach proved extremely robust since it eliminated the over-constraint that caused 'locking' and provided smooth force variations in large sliding. Here, we extend this previous approach to treat frictional contact problems. In addition, the method is extended to 3D quadratic tetrahedrals and hexahedrals. The proposed approach is then applied to several challenging frictional contact problems that demonstrate its effectiveness.
Date: April 1, 2004
Creator: Puso, M; Laursen, T & Solberg, J
Object Type: Article
System: The UNT Digital Library
Biodiesel is Working Hard in Kentucky (open access)

Biodiesel is Working Hard in Kentucky

This 4-page Clean Cities fact sheet describes the use of biodiesel fuel in 6 school districts throughout Kentucky. It contains usage information for each school district, as well as contact information for local Clean Cities Coordinators and Biodiesel suppliers.
Date: April 1, 2004
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Consider Installing Turbulators on Two- and Three-Pass Firetube Boilers; Industrial Technologies Program (ITP) (open access)

Consider Installing Turbulators on Two- and Three-Pass Firetube Boilers; Industrial Technologies Program (ITP)

These tip sheets provide steam system optimization information that can be implemented immediately in manufacturing facilities to achieve more energy-efficient processes.
Date: April 1, 2004
Creator: unknown
Object Type: Text
System: The UNT Digital Library
National Renewable Energy Laboratory 2003 Research Review (open access)

National Renewable Energy Laboratory 2003 Research Review

In-depth articles on several NREL technologies and advances, including: production of hydrogen using renewable resources and technologies; use of carbon nanotubes for storing hydrogen; enzymatic reduction of cellulose to simple sugars as a platform for making fuel, chemicals, and materials; and the potential of electricity from wind energy to offset carbon dioxide emissions. Also covered are NREL news, awards and honors received by the Laboratory, and patents granted to NREL researchers.
Date: April 1, 2004
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Introduction to Building Systems Performance: Houses That Work II; Period of Performance: January 2003--December 2003 (open access)

Introduction to Building Systems Performance: Houses That Work II; Period of Performance: January 2003--December 2003

Buildings should be suited to their environments. Design and construction must be responsive to varying seismic risks, wind loads, and snow loads, as well as soil conditions, frost depth, orientation, and solar radiation. In addition, building envelopes and mechanical systems should be designed for a specific hygro-thermal regions, rain exposure, and interior climate. The Building Science Consortium (BSC) design recommendations are based on the hygro-thermal regions with reference to the annual rainfall. Local climate must be addressed if it differs significantly from the climate described for a particular design.
Date: April 1, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Electron Cloud Phase Transitions (open access)

Electron Cloud Phase Transitions

N/A
Date: April 1, 2004
Creator: U., Iriso & Peggs, S.
Object Type: Report
System: The UNT Digital Library
Final Phase II Report : QuickSite{reg_sign} investigation, Centralia, Kansas. (open access)

Final Phase II Report : QuickSite{reg_sign} investigation, Centralia, Kansas.

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), formerly operated a grain storage facility approximately 1,100 ft north of Centralia from 1949 until 1971. Subsequently, a concrete mixing plant operated on the site (FSA 1997). None of the CCC/USDA structures remain, though belowgrade foundations related to structures associated with the concrete mixing operations are evident. Two additional grain storage facilities currently exist in and near Centralia: the Nemaha County Co-op, approximately 4,000 ft south of the former CCC/USDA facility, and a private grain storage facility near the Don Morris residence, 3,500 ft north of the former CCC/USDA facility (Figure 1.1). The property on which the former facility was located is currently owned by Jeanne Burdett Lacky of Seneca, Kansas. In August-September 1998 the Kansas Department of Health and Environment (KDHE) conducted preliminary investigations at the former CCC/USDA facility, on the basis of the detection of carbon tetrachloride in the domestic well at the Don Morris residence (north of the former CCC/USDA facility). Prior to 1986, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the grain storage industry to preserve grain. The details of previous investigations in the area and …
Date: April 1, 2004
Creator: LaFreniere, L. (Environmental Research)
Object Type: Report
System: The UNT Digital Library
A reformulation of intrabeam scattering theory (open access)

A reformulation of intrabeam scattering theory

N/A
Date: April 1, 2004
Creator: Parzen, G.
Object Type: Report
System: The UNT Digital Library
Results from ORNL Characterization of Archive German Particles (open access)

Results from ORNL Characterization of Archive German Particles

This document is a compilation of the characterization data obtained on a sample of TRISO-coated 500 {micro}m UO{sub 2} produced by the Germans and obtained by the AGR program for use as a reference material. This sample came from the EUO 2358-2365 composite studied by General Atomics (GA) and referenced in GA document No.910852 'Acceptance Test report for German Fuel Particles'. The ORNL designation for the material characterized was AGR-06.
Date: April 1, 2004
Creator: Hunn, John D
Object Type: Report
System: The UNT Digital Library
MOAB : a mesh-oriented database. (open access)

MOAB : a mesh-oriented database.

A finite element mesh is used to decompose a continuous domain into a discretized representation. The finite element method solves PDEs on this mesh by modeling complex functions as a set of simple basis functions with coefficients at mesh vertices and prescribed continuity between elements. The mesh is one of the fundamental types of data linking the various tools in the FEA process (mesh generation, analysis, visualization, etc.). Thus, the representation of mesh data and operations on those data play a very important role in FEA-based simulations. MOAB is a component for representing and evaluating mesh data. MOAB can store structured and unstructured mesh, consisting of elements in the finite element 'zoo'. The functional interface to MOAB is simple yet powerful, allowing the representation of many types of metadata commonly found on the mesh. MOAB is optimized for efficiency in space and time, based on access to mesh in chunks rather than through individual entities, while also versatile enough to support individual entity access. The MOAB data model consists of a mesh interface instance, mesh entities (vertices and elements), sets, and tags. Entities are addressed through handles rather than pointers, to allow the underlying representation of an entity to change …
Date: April 1, 2004
Creator: Tautges, Timothy James; Ernst, Corey; Stimpson, Clint; Meyers, Ray J. & Merkley, Karl
Object Type: Report
System: The UNT Digital Library
Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation; Coeur d'Alene Tribe Fish, Water, and Wildlife Program, REVISED 2002 Annual Report. (open access)

Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation; Coeur d'Alene Tribe Fish, Water, and Wildlife Program, REVISED 2002 Annual Report.

Historically, the Coeur d'Alene Indian Tribe depended on runs of anadromous salmon and steelhead along the Spokane River and Hangman Creek, as well as resident and adfluvial forms of trout and char in Coeur d'Alene Lake, for survival. Dams constructed in the early 1900s on the Spokane River in the City of Spokane and at Little Falls (further downstream) were the first dams that initially cut-off the anadromous fish runs from the Coeur d'Alene Tribe. These fisheries were further removed by the construction of Chief Joseph and Grand Coulee Dams on the Columbia River. Together, these actions forced the Tribe to rely solely on the resident fish resources of Coeur d'Alene Lake (Staff Communication). The Coeur d'Alene Tribe is estimated to have historically harvested around 42,000 westslope cutthroat trout (Oncorhynchus clarki) per year (Scholz et al. 1985). In 1967, Mallet (1969) reported that 3,329 cutthroat were harvested from the St. Joe River, and a catch of 887 was reported from Coeur d'Alene Lake. This catch is far less than the 42,000 fish per year the tribe harvested historically. Today, only limited opportunities exist to harvest cutthroat trout in the Coeur d'Alene Basin. The declines in native salmonid fish populations, particularly …
Date: April 1, 2004
Creator: Vitale, Angelo; Lamb, Dave & Scott, Jason
Object Type: Report
System: The UNT Digital Library
Development of the Embedded Membrane Concept (open access)

Development of the Embedded Membrane Concept

Recent evaluations in the field of biomass separations have resulted in a novel concept termed the “embedded membrane.” Biomass solutions, which typically consist of a sludge-like material, contain a wide range of particle types and concentrations. These highly abusive solutions have the potential to cause reduced flux and even catastrophic failure through erosion mechanisms within the membrane. The embedded membrane concept relies on embedding finer, filtration inducing particles (e.g. ceramic such as TiO2) into the interstices of a macroporous support (e.g., sintered metal such as sintered stainless steel). It is believed that the embedded membrane would be resistant to erosion processes, since only the macroporous support material would be subjected to the harsh hydrodynamic properties of the flowing bulk process fluid. Moreover, the finer, filtration inducing embedded particles that provide the necessary filtration efficiency are protected from the bulk process fluid. In an effort to investigate the embedded membrane concept, samples of sintered stainless steel membranes embedded with ceramic particles have been prepared.
Date: April 1, 2004
Creator: Mann, Nick R.; Herbst, R. S. & Trowbridge, T. L.
Object Type: Article
System: The UNT Digital Library
New geothermal site identification and qualification. Final report (open access)

New geothermal site identification and qualification. Final report

This study identifies remaining undeveloped geothermal resources in California and western Nevada, and it estimates the development costs of each. It has relied on public-domain information and such additional data as geothermal developers have chosen to make available. Reserve estimation has been performed by volumetric analysis with a probabilistic approach to uncertain input parameters. Incremental geothermal reserves in the California/Nevada study area have a minimum value of 2,800 grosss MW and a most-likely value of 4,300 gross MW. For the state of California alone, these values are 2,000 and 3,000 gross MW, respectively. These estimates may be conservative to the extent that they do not take into account resources about which little or no public-domain information is available. The average capital cost of incremental generation capacity is estimated to average $3,100/kW for the California/Nevada study area, and $2,950/kW for the state of California alone. These cost estimates include exploration, confirmation drilling, development drilling, plant construction, and transmission-line costs. For the purposes of this study, a capital cost of $2,400/kW is considered competitive with other renewable resources. The amount of incremental geothermal capacity available at or below $2,400/kW is about 1,700 gross MW for the California/Nevada study area, and the same …
Date: April 1, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Corrective measures evaluation work plan Technical Area V groundwater. (open access)

Corrective measures evaluation work plan Technical Area V groundwater.

This document, which is prepared as directed by the Compliance Order on Consent (COOC) issued by the New Mexico Environment Department, identifies and outlines a process to evaluate remedial alternatives to identify a corrective measure for the Sandia National Laboratories New Mexico Technical Area (TA)-V Groundwater. The COOC provides guidance for implementation of a Corrective Measures Evaluation (CME) for the TA-V Groundwater. This Work Plan documents an initial screening of remedial technologies and presents a list of possible remedial alternatives for those technologies that passed the screening. This Work Plan outlines the methods for evaluating these remedial alternatives and describes possible site-specific evaluation activities necessary to estimate remedy effectiveness and cost. These methods will be reported in the CME Report. This Work Plan outlines the CME Report, including key components and a description of the corrective measures process.
Date: April 1, 2004
Creator: Lebow, Patrick S.; Dettmers, Dana L. & Hall, Kevin A.
Object Type: Report
System: The UNT Digital Library