Next generation spindles for micromilling. (open access)

Next generation spindles for micromilling.

There exists a wide variety of important applications for micro- and meso-scale mechanical systems in the commercial and defense sectors, which require high-strength materials and complex geometries that cannot be produced using current MEMS fabrication technologies. Micromilling has great potential to fill this void in MEMS technology by adding the capability of free form machining of complex 3D shapes from a wide variety and combination of traditional, well-understood engineering alloys, glasses and ceramics. Inefficiencies in micromilling result from the relationships between a cutting tool's breaking strength, the applied cutting force, and the metal removal rate. Because machining times in mesofeatures scale inversely to the part size, a feature 1/10th as large will take 10 times as long to machine. Also, required chip sizes of 1 m or less are cut with tools having edge radius of 2-3 m, the cutting edge effectively has a highly negative rake angle, cutting forces are increased significantly causing chip loads to be further reduced and the machining takes even longer than predicted above. However, cutting forces do not increase with cutting speed, so faster spindles with reduced tool runout are the path to achieve efficient mesoscale milling. This research explored the development of new …
Date: December 1, 2004
Creator: Pathak, Jay P. (Machine Tool Research Center, University of Florida, Gainesville, FL); Payne, Scott W. T. (Machine Tool Research Center, University of Florida, Gainesville, FL); Gill, David Dennis; Ziegert, John C. (Machine Tool Research Center, University of Florida, Gainesville, FL) & Jokiel, Bernhard, Jr.
Object Type: Report
System: The UNT Digital Library
Medical waste management plan. (open access)

Medical waste management plan.

This plan describes the process for managing research generated medical waste at Sandia National Laboratories/California. It applies to operations at the Chemical and Radiation Detection Laboratory (CRDL), Building 968, and other biosafety level 1 or 2 activities at the site. It addresses the accumulation, storage, treatment and disposal of medical waste and sharps waste. It also describes the procedures to comply with regulatory requirements and SNL policies applicable to medical waste.
Date: December 1, 2004
Creator: Lane, Todd W. & VanderNoot, Victoria A.
Object Type: Report
System: The UNT Digital Library
P3 microengine development at Washington State University. (open access)

P3 microengine development at Washington State University.

There is a pressing need for miniaturized power systems for a variety of applications requiring a long life in the field of operations. Such power systems are required to be capable of providing power for months to years of operation, which all but eliminates battery technologies and technologies that bring their own fuel systems (except for nuclear fuel systems, which have their own drawbacks) due to constraints of having the all of the chemical fuel necessary for the entire life of the operational run available at the starting point of the operation. Alternatively, harvesting energy directly from the local environment obviates this need for bringing along all of the fuel necessary for operation. Instead, locally available energy, either in the form of chemical, thermal, light, or motion can be harvested and converted into electrical energy for use in sensor applications. The work from this LDRD is focused on developing a thermal engine that can take scavenged thermal gradients and convert them into direct electrical energy. The converter system is a MEMS based external combustion engine that uses a modified Stirling cycle to generate mechanical work on a piezoelectric generator. This piezoelectric generator then produced an AC voltage and current that …
Date: December 1, 2004
Creator: Whalen, Scott (Washington State University, Pullman, WA) & Apblett, Christopher Alan
Object Type: Report
System: The UNT Digital Library
Final report : compliant thermo-mechanical MEMS actuators, LDRD #52553. (open access)

Final report : compliant thermo-mechanical MEMS actuators, LDRD #52553.

Thermal actuators have proven to be a robust actuation method in surface-micromachined MEMS processes. Their higher output force and lower input voltage make them an attractive alternative to more traditional electrostatic actuation methods. A predictive model of thermal actuator behavior has been developed and validated that can be used as a design tool to customize the performance of an actuator to a specific application. This tool has also been used to better understand thermal actuator reliability by comparing the maximum actuator temperature to the measured lifetime. Modeling thermal actuator behavior requires the use of two sequentially coupled models, the first to predict the temperature increase of the actuator due to the applied current and the second to model the mechanical response of the structure due to the increase in temperature. These two models have been developed using Matlab for the thermal response and ANSYS for the structural response. Both models have been shown to agree well with experimental data. In a parallel effort, the reliability and failure mechanisms of thermal actuators have been studied. Their response to electrical overstress and electrostatic discharge has been measured and a study has been performed to determine actuator lifetime at various temperatures and operating …
Date: December 1, 2004
Creator: Walraven, Jeremy Allen; Baker, Michael Sean; Headley, Thomas Jeffrey & Plass, Richard Anton
Object Type: Report
System: The UNT Digital Library
Meso-scale controlled motion for a microfluidic drop ejector. (open access)

Meso-scale controlled motion for a microfluidic drop ejector.

The objective of this LDRD was to develop a uniquely capable, novel droplet solution based manufacturing system built around a new MEMS drop ejector. The development all the working subsystems required was completed, leaving the integration of these subsystems into a working prototype still left to accomplish. This LDRD report will focus on the three main subsystems: (1) MEMS drop ejector--the MEMS ''sideshooter'' effectively ejected 0.25 pl drops at 10 m/s, (2) packaging--a compact ejector package based on a modified EMDIP (Electro-Microfluidic Dual In-line Package--SAND2002-1941) was fabricated, and (3) a vision/stage system allowing precise ejector package positioning in 3 dimensions above a target was developed.
Date: December 1, 2004
Creator: Galambos, Paul C.; Givler, Richard C.; Pohl, Kenneth Roy; Czaplewski, David A.; Luck, David L.; Braithwaite, Mark J. et al.
Object Type: Report
System: The UNT Digital Library
Lipid membranes on nanostructured silicon. (open access)

Lipid membranes on nanostructured silicon.

A unique composite nanoscale architecture that combines the self-organization and molecular dynamics of lipid membranes with a corrugated nanotextured silicon wafer was prepared and characterized with fluorescence microscopy and scanning probe microscopy. The goal of this project was to understand how such structures can be assembled for supported membrane research and how the interfacial interactions between the solid substrate and the soft, self-assembled material create unique physical and mechanical behavior through the confinement of phases in the membrane. The nanometer scale structure of the silicon wafer was produced through interference lithography followed by anisotropic wet etching. For the present study, a line pattern with 100 nm line widths, 200 nm depth and a pitch of 360 nm pitch was fabricated. Lipid membranes were successfully adsorbed on the structured silicon surface via membrane fusion techniques. The surface topology of the bilayer-Si structure was imaged using in situ tapping mode atomic force microscopy (AFM). The membrane was observed to drape over the silicon structure producing an undulated topology with amplitude of 40 nm that matched the 360 nm pitch of the silicon structure. Fluorescence recovery after photobleaching (FRAP) experiments found that on the microscale those same structures exhibit anisotropic lipid mobility that …
Date: December 1, 2004
Creator: Slade, Andrea Lynn; Lopez, Gabriel P. (University of New Mexico, Albuquerque, NM); Ista, Linnea K. (University of New Mexico, Albuquerque, NM); O'Brien, Michael J. (University of New Mexico, Albuquerque, NM); Sasaki, Darryl Yoshio; Bisong, Paul (University of New Mexico, Albuquerque, NM) et al.
Object Type: Report
System: The UNT Digital Library
Revolutionary systems for catalytic combustion and diesel catalytic particulate traps. (open access)

Revolutionary systems for catalytic combustion and diesel catalytic particulate traps.

This report is a summary of an LDRD project completed for the development of materials and structures conducive to advancing the state of the art for catalyst supports and diesel particulate traps. An ancillary development for bio-medical bone scaffolding was also realized. Traditionally, a low-pressure drop catalyst support, such as a ceramic honeycomb monolith, is used for catalytic reactions that require high flow rates of gases at high-temperatures. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. ''Robocasting'' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low-pressure drops. These alternative 3-dimensional geometries may also provide a foundation for the development of self-regenerating supports capable of trapping and combusting soot particles from a diesel engine exhaust stream. This report describes the structures developed and characterizes the improved catalytic performance that can result. The results show that, relative to honeycomb monolith supports, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a …
Date: December 1, 2004
Creator: Stuecker, John Nicholas; Witze, Peter O.; Ferrizz, Robert Matthew; Cesarano, Joseph, III & Miller, James Edward
Object Type: Report
System: The UNT Digital Library
A digital accelerometer array utilizing suprathreshold stochastic resonance for detection of sub-Brownian noise floor accelerations. (open access)

A digital accelerometer array utilizing suprathreshold stochastic resonance for detection of sub-Brownian noise floor accelerations.

The goal of this LDRD project was to evaluate the possibilities of utilizing Stochastic resonance in micromechanical sensor systems as a means for increasing signal to noise for physical sensors. A careful study of this field reveals that in the case of a single sensing element, stochastic resonance offers no real advantage. We have, however, identified a system that can utilize very similar concepts to stochastic resonance in order to achieve an arrayed sensor system that could be superior to existing technologies in the field of inertial sensors, and could offer a very low power technique for achieving navigation grade inertial measurement units.
Date: December 1, 2004
Creator: Carr, Dustin Wade & Olsson, Roy H.
Object Type: Report
System: The UNT Digital Library
Performance of Personal Workspace Controls Final Report (open access)

Performance of Personal Workspace Controls Final Report

One of the key deliverables for the DOE-funded controls research at LBNL for FY04 was the development of a prototype Personal Workspace Control system. The successful development of this system is a critical milestone for the LBNL Lighting Controls Research effort because this system demonstrates how IBECS can add value to today's Task Ambient lighting systems. LBNL has argued that by providing both the occupant and the facilities manager with the ability to precisely control the operation of overhead lighting and all task lighting in a coordinated manner, that task ambient lighting can optimize energy performance and occupant comfort simultaneously [Reference Task Ambient Foundation Document]. The Personal Workspace Control system is the application of IBECS to this important lighting problem. This report discusses the development of the Personal Workspace Control to date including descriptions of the different fixture types that have been converted to IBECS operation and a detailed description of the operation of PWC Scene Controller, which provides the end user with precise control of his task ambient lighting system. The objective, from the Annual Plan, is to demonstrate improvements in efficiency, lighting quality and occupant comfort realized using Personal Workspace Controls (PWC) designed to optimize the delivery of …
Date: December 1, 2004
Creator: Rubinstein, Francis; Kiliccote, Sila; Loffeld, John; Pettler,Pete & Snook, Joel
Object Type: Report
System: The UNT Digital Library
Climate change effects on international stability : a white paper. (open access)

Climate change effects on international stability : a white paper.

This white paper represents a summary of work intended to lay the foundation for development of a climatological/agent model of climate-induced conflict. The paper combines several loosely-coupled efforts and is the final report for a four-month late-start Laboratory Directed Research and Development (LDRD) project funded by the Advanced Concepts Group (ACG). The project involved contributions by many participants having diverse areas of expertise, with the common goal of learning how to tie together the physical and human causes and consequences of climate change. We performed a review of relevant literature on conflict arising from environmental scarcity. Rather than simply reviewing the previous work, we actively collected data from the referenced sources, reproduced some of the work, and explored alternative models. We used the unfolding crisis in Darfur (western Sudan) as a case study of conflict related to or triggered by climate change, and as an exercise for developing a preliminary concept map. We also outlined a plan for implementing agents in a climate model and defined a logical progression toward the ultimate goal of running both types of models simultaneously in a two-way feedback mode, where the behavior of agents influences the climate and climate change affects the agents. Finally, …
Date: December 1, 2004
Creator: Murphy, Kathryn; Taylor, Mark A.; Fujii, Joy; Malczynski, Leonard A.; McNamara, Laura A.; Reinert, Rhonda K. et al.
Object Type: Report
System: The UNT Digital Library
Corrective measures evaluation work plan : Technical Area V Groundwater : revision 0. (open access)

Corrective measures evaluation work plan : Technical Area V Groundwater : revision 0.

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: December 1, 2004
Creator: Lebow, Patrick S.; Dettmers, Dana L. & Hall, Kevin A.
Object Type: Report
System: The UNT Digital Library
NorthAm Fest : fostering a North American continent approach to countering terrorism. (open access)

NorthAm Fest : fostering a North American continent approach to countering terrorism.

On September 14-16, 2004, the Advanced Concepts Group of Sandia National Laboratories in conjunction with the University of Texas at El Paso and the North American Institute hosted a workshop (fest) designed to explore the concept of a North American continental approach to countering terrorism. The fest began with the basic premise that the successful defense of North America against the threat of terrorism will require close collaboration among the North American allies--Canada, Mexico and the U.S.--as well as a powerful set of information collection and analysis tools and deterrence strategies. The NorthAm Fest recast the notion of ''homeland defense'' as a tri-national effort to protect the North American continent against an evolving threat that respects no borders. This is a report of the event summarizing the ideas explored. The fest examined the uniqueness of dealing with terrorism from a tri-national North American viewpoint, the role and possible features of joint security systems, concepts for ideal continental security systems for North America, and the challenges and opportunities for such systems to become reality. The following issues were identified as most important for the advancement of this concept. (1) The three countries share a set of core values--democracy, prosperity and security--which …
Date: December 1, 2004
Creator: Gerdes, Dick (North American Institute, Santa Fe, NM); Moore, Judy Hennessey; Whitley, John B.; Turnley, Jessica Glicken (Galisteo Consulting Group, Inc., Albuquerque, NM) & Oborotova, Marina (Center for International Studies of El Colegio de Mexico)
Object Type: Report
System: The UNT Digital Library
Evaluation of ingredients for the development of new insensitive munitions. (open access)

Evaluation of ingredients for the development of new insensitive munitions.

Several ingredients being considered by the U.S. Army for the development of new insensitive munitions have been examined. One set of ingredients consists of 2,4-dinitrophenylhydrazine (DNPH) and hexahydro-1,3,5-trinitro-s-triazine (RDX). In this set, the decomposition of the mixture was examined to determine whether adding DNPH to RDX would generate a sufficient quantity of gas to rupture the case of a munition prior to the onset of the rapid reaction of RDX, thus mitigating the violence of reaction. The second set of ingredients consists of three different reduced sensitivity RDX (RS-RDX) powders manufactured by SNPE and Dyno-Nobel. In this set, the objective was to determine properties of RS-RDX powders that may distinguish them from normal RDX powder and may account for their reduced shock sensitivity. The decomposition reactions and sublimation properties of these materials were examined using two unique instruments: the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) instrument and the Fourier Transform ion cyclotron resonance (FTICR) mass spectrometry instrument. These instruments provide the capability to examine the details of decomposition reactions in energetic materials. DNPH does not appear to be a good candidate to mitigate the violence of the RDX reaction in a munition. DNPH decomposes between 170 C and 180 …
Date: December 1, 2004
Creator: Maharrey, Sean P.; Johnston, Lois A.; Behrens, Richard, Jr. & Wiese-Smith, Deneille
Object Type: Report
System: The UNT Digital Library
Development of the augmented musculature device. (open access)

Development of the augmented musculature device.

We developed an Augmented Musculature Device (AMD) that assists the movements of its wearer. It has direct application to aiding military and law enforcement personnel, the neurologically impaired, or those requiring any type of cybernetic assistance. The AMD consists of a collection of artificial muscles, each individually actuated, strategically placed along the surface of the human body. The actuators employed by the AMD are known as 'air muscles' and operate pneumatically. They are commercially available from several vendors and are relatively inexpensive. They have a remarkably high force-to-weight ratio--as high as 400:1 (as compared with 16:1 typical of DC motors). They are flexible and elastic, even when powered, making them ideal for interaction with humans.
Date: December 1, 2004
Creator: Rohrer, Brandon Robinson & Pankretz, Ty
Object Type: Report
System: The UNT Digital Library
Initial cost analysis of a desalination process utilizing hydrotalcite and permutite for ion sequestration. (open access)

Initial cost analysis of a desalination process utilizing hydrotalcite and permutite for ion sequestration.

An initial cost analysis of a proposed desalination process was performed. The proposed process utilizes tailored inorganic ion exchangers, hydrotalcite and permutite, to sequester anions and cations from a brackish water solution. Three different process scenarios were considered: (1) disposal of the spent exchangers as dry waste (2) conventional chemical regeneration, and (3) acid regeneration of permutite coupled with thermal (550 C) regeneration of hydrotalcite. Disposal of the resin and conventional regeneration are not viable options from an economic standpoint. Applying limited data and optimistic assumptions to the third scenario yielded an estimate of $2.34/kgal of product water. Published values for applying conventional reverse osmosis to similar water streams range from $0.70 to $2.65/kgal. Consistent with these baseline values, the Water Treatment Estimation Routine, WaTER, developed by the United States Department of the Interior, Bureau of Reclamation produced a cost estimate of $1.16/kgal for brackish water reverse osmosis.
Date: December 1, 2004
Creator: Miller, James Edward & Evans, Lindsey R.
Object Type: Report
System: The UNT Digital Library
LDRD final report on nanovehicle light-driven propulsion. (open access)

LDRD final report on nanovehicle light-driven propulsion.

Having demonstrated the possibility of constructing nanoscale metallic vehicular bodies as described in last year's proposal, our goals have been to make uniform preparations of the metallized lipid assemblies and to determine the feasibility of powering these nanostructures with biological motors that are activated and driven by visible light. We desired that the propulsion system be constructed entirely by self-assembly and powered by a photocatalytic process partially already built into the nanovehicle. The nanovehicle we desire to build is composed of both natural biological components (ATPase, kinesin-microtubules) and biomimetic components (platinized liposomes, photosynthetic membrane) as functional units. The vehicle's body was originally envisioned to be composed of a surfactant liposomal bilayer coated with platinum nanoparticles, but instead of the expected nanoparticles we were able to grow dendritic 2-nm thick platinum sheets on the liposomes. Now, we have shown that it is possible to completely enclose the liposomes with sheeting to form porous platinum spheres, which show good structural stability as evidenced by their ability to survive the stresses of electron-microscopy sample preparation. Our goals were to control the synthesis of the platinized liposomes well enough to make uniform preparations of the coated individual liposomes and to develop the propulsion system …
Date: December 1, 2004
Creator: Singh, Anup K.; van Swol, Frank B.; Shelnutt, John Allen; Medforth, Craig J. & Song, Yujiang
Object Type: Report
System: The UNT Digital Library
Geologic investigation of Playa Lakes, Tonopah Test Range, Nevada : data report. (open access)

Geologic investigation of Playa Lakes, Tonopah Test Range, Nevada : data report.

Subsurface geological investigations have been conducted at two large playa lakes at the Tonopah Test Range in central Nevada. These characterization activities were intended to provide basic stratigraphic-framework information regarding the lateral distribution of ''hard'' and ''soft'' sedimentary materials for use in defining suitable target regions for penetration testing. Both downhole geophysical measurements and macroscopic lithilogic descriptions were used as a surrogate for quantitative mechanical-strength properties, although some quantitative laboratory strength measurements were obtained as well. Both rotary (71) and core (19) holes on a systematic grid were drilled in the southern half of the Main Lake; drill hole spacings are 300 ft north-south and 500-ft east-west. The drilled region overlaps a previous cone-penetrometer survey that also addressed the distribution of hard and soft material. Holes were drilled to a depth of 40 ft and logged using both geologic examination and down-hole geophysical surveying. The data identify a large complex of very coarse-grained sediment (clasts up to 8 mm) with interbedded finer-grained sands, silts and clays, underlying a fairly uniform layer of silty clay 6 to 12 ft thick. Geophysical densities of the course-grained materials exceed 2.0 g/cm{sup 2}, and this petrophysical value appears to be a valid discriminator of …
Date: December 1, 2004
Creator: Rautman, Christopher Arthur
Object Type: Report
System: The UNT Digital Library
A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes (open access)

A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes

Above-boiling temperature conditions, as encountered, forexample, in geothermal reservoirs and in geologic repositories for thestorage of heat-producing nuclear wastes, may give rise to stronglyaltered liquid and gas flow processes in porous subsurface environments.The magnitude of such flow perturbation is extremely hard to measure inthe field. We therefore propose a simple temperature-profile method thatuses high-resolution temperature data for deriving such information. Theenergy that is transmitted with the vapor and water flow creates a nearlyisothermal zone maintained at about the boiling temperature, referred toas a heat pipe. Characteristic features of measured temperature profiles,such as the differences in the gradients inside and outside of the heatpipe regions, are used to derive the approximate magnitude of the liquidand gas fluxes in the subsurface, for both steady-state and transientconditions.
Date: December 6, 2004
Creator: Birkholzer, Jens T.
Object Type: Article
System: The UNT Digital Library
Characterization of U(VI) Sorption-Desoprtion Processes and Model Upscaling (open access)

Characterization of U(VI) Sorption-Desoprtion Processes and Model Upscaling

In order to apply predictive reactive transport models to the Hanford site, detailed knowledge of the speciation of contaminants is required. Important speciation parameters include: (1) oxidation state; (2) the local molecular structure surrounding contaminant elements; (3) the type and binding of a contaminant ion sorption complex (if adsorbed); (4) the type(s) of phase within which a contaminant is structurally incorporated [e.g., present in a three-dimensional precipitate(s)]; (5) the phase associations of a contaminant; (6) the microscopic distribution of a contaminant within sediments and soils. In the present study, we have used synchrotron-based X-ray spectroscopic methods to study the speciation of U and Cu in contaminated soil and sediment samples from the Hanford Site. To complement and complete our initial XAFS investigation of U speciation in contaminated vadose zone sediments below tank BX-102, we have also performed mXRD studies of two sediment sample to identify the specific U(VI)-silicate phase present. Samples from the 300 Area were examined by mSXRF to determine the microscopic distribution and element associations of Cu and U. These samples were also analyzed by U LIII- and Cu K-edge XAFS spectroscopy to determine the chemical speciation of these elements.
Date: December 1, 2004
Creator: Ball, William P.
Object Type: Report
System: The UNT Digital Library
An Analysis of Energy Savings Possible Through Advances in Automotive Tooling Technology (open access)

An Analysis of Energy Savings Possible Through Advances in Automotive Tooling Technology

The use of lightweight and highly formable advanced materials in automobile and truck manufacturing has the potential to save fuel. Advances in tooling technology would promote the use of these materials. This report describes an energy savings analysis performed to approximate the potential fuel savings and consequential carbon-emission reductions that would be possible because of advances in tooling in the manufacturing of, in particular, non-powertrain components of passenger cars and heavy trucks. Separate energy analyses are performed for cars and heavy trucks. Heavy trucks are considered to be Class 7 and 8 trucks (trucks rated over 26,000 lbs gross vehicle weight). A critical input to the analysis is a set of estimates of the percentage reductions in weight and drag that could be achieved by the implementation of advanced materials, as a consequence of improved tooling technology, which were obtained by surveying tooling industry experts who attended a DOE Workshop, Tooling Technology for Low-Volume Vehicle Production, held in Seattle and Detroit in October and November 2003. The analysis is also based on 2001 fuel consumption totals and on energy-audit component proportions of fuel use due to drag, rolling resistance, and braking. The consumption proportions are assumed constant over time, but …
Date: December 3, 2004
Creator: Rick Schmoyer, RLS
Object Type: Report
System: The UNT Digital Library
Simplified Design Criteria for Very High Temperature Applications in Generation IV Reactors (open access)

Simplified Design Criteria for Very High Temperature Applications in Generation IV Reactors

The goal of this activity is to provide simplified criteria which can be used in rapid feasibility assessments of the structural viability of very high temperature components in conceptual and early preliminary design phases for Generation IV reactors. The current criteria in ASME Code Section III, Subsection NH, hereafter referred to as NH, (and Code Case N-201 for core support structures) are difficult and require a complex deconstruction of finite element analysis results for their implementation. Further, and most important, times, temperatures and some materials of interest to the very high temperature Generation IV components are not covered by the current provisions of NH. Future revisions to NH are anticipated that will address very high temperature Generation IV components and materials requirements but, until that occurs interim guidance is required for design activities to proceed. These simplified criteria are for design guidance and are not necessarily in rigorous compliance with NH methodology. Rather, the objective is for criteria which address the early design needs of very high temperature Generation IV components and materials. The intent is to provide simplified but not overly conservative design methods. When more rigorous criteria and methods are incorporated in NH, the degree of conservatism should …
Date: December 15, 2004
Creator: McGreevy, TE
Object Type: Report
System: The UNT Digital Library
Rapid detection of biothreat agents based on cellular machinery. (open access)

Rapid detection of biothreat agents based on cellular machinery.

This research addresses rapid and sensitive identification of biological agents in a complex background. We attempted to devise a method by which the specificity of the cellular transcriptional machinery could be used to detect and identify bacterial bio-terror agents in a background of other organisms. Bacterial cells contain RNA polymerases and transcription factors that transcribe genes into mRNA for translation into proteins. RNA polymerases in conjunction with transcription factors recognize regulatory elements (promoters) upstream of the gene. These promoters are, in many cases, recognized by the polymerase and transcription factor combinations of one species only. We have engineered a plasmid, for Escherichia coli, containing the virA promoter from the target species Shigella flexneri. This promoter was fused to a reporter gene Green Fluorescent Protein (GFP). In theory the indicator strain (carrying the plasmid) is mixed with the target strain and the two are lysed. The cellular machinery from both cells mixes and the GFP is produced. This report details the results of testing this system.
Date: December 1, 2004
Creator: Lane, Todd W. & Gantt, Richard W.
Object Type: Report
System: The UNT Digital Library
Database of prompt gamma rays from slow neutron capture forelemental analysis (open access)

Database of prompt gamma rays from slow neutron capture forelemental analysis

The increasing importance of Prompt Gamma-ray ActivationAnalysis (PGAA) in a broad range of applications is evident, and has beenemphasized at many meetings related to this topic (e.g., TechnicalConsultants' Meeting, Use of neutron beams for low- andmedium-fluxresearch reactors: radiography and materialscharacterizations, IAEA Vienna, 4-7 May 1993, IAEA-TECDOC-837, 1993).Furthermore, an Advisory Group Meeting (AGM) for the Coordination of theNuclear Structure and Decay Data Evaluators Network has stated that thereis a need for a complete and consistent library of cold- and thermalneutron capture gammaray and cross-section data (AGM held at Budapest,14-18 October 1996, INDC(NDS)-363); this AGM also recommended theorganization of an IAEA CRP on the subject. The International NuclearData Committee (INDC) is the primary advisory body to the IAEA NuclearData Section on their nuclear data programmes. At a biennial meeting in1997, the INDC strongly recommended that the Nuclear Data Section supportnew measurements andupdate the database on Neutron-induced PromptGamma-ray Activation Analysis (21st INDC meeting, INDC/P(97)-20). As aconsequence of the various recommendations, a CRP on "Development of aDatabase for Prompt Gamma-ray Neutron Activation Analysis (PGAA)" wasinitiated in 1999. Prior to this project, several consultants had definedthe scope, objectives and tasks, as approved subsequently by the IAEA.Each CRP participant assumed responsibility for the execution of specifictasks. …
Date: December 31, 2004
Creator: Firestone, R. B.; Choi, H. D.; Lindstrom, R. M.; Molnar, G. L.; Mughabghab, S. F.; Paviotti-Corcuera, R. et al.
Object Type: Report
System: The UNT Digital Library
Sustaining the Landscape: A Method for Comparing Current and Desired Future Conditions of Forest Ecosystems in the North Cumberland Plateau and Mountains (open access)

Sustaining the Landscape: A Method for Comparing Current and Desired Future Conditions of Forest Ecosystems in the North Cumberland Plateau and Mountains

This project initiates an integrated-landscape conservation approach within the Northern Cumberlands Project Area in Tennessee and Kentucky. The mixed mesophytic forests within the Cumberland Plateau and Mountains are among the most diverse in North America; however, these forests have been impacted by and remain threatened from changes in land use across this landscape. The integrated-landscape conservation approach presented in this report outlines a sequence of six conservation steps. This report considers the first three of these steps in two, successive stages. Stage 1 compares desired future conditions (DFCs) and current prevailing conditions (CPCs) at the landscape-scale utilizing remote sensing imagery, remnant forests, and descriptions of historical forest types within the Cumberland Plateau. Subsequently, Stage 2 compares DFCs and CPCs for at-risk forest types identified in Stage 1 utilizing structural, compositional, or functional attributes from USFS Forest Inventory and Analysis data. Ecological indicators will be developed from each stage that express the gaps between these two realizations of the landscape. The results from these first three steps will directly contribute to the final three steps of the integrated-landscape conservation approach by providing guidance for the generation of new conservation strategies in the Northern Cumberland Plateau and Mountains.
Date: December 22, 2004
Creator: Druckenbrod, D. L.
Object Type: Report
System: The UNT Digital Library