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Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis
Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. The importance of this symbiosis to reef-building corals and reef nutrient and carbon cycles is well documented, but little is known about the mechanisms by which the partners establish and regulate the symbiosis. Because the dinoflagellate symbionts live inside the cells of their host coral, the interactions between the partners occur on cellular and molecular levels, as each partner alters the expression of genes and proteins to facilitate the partnership. These interactions can examined using high-throughput techniques that allow thousands of genes to be examined simultaneously. We are developing the groundwork so that we can use DNA microarray profiling to identify genes involved in the Montastraea faveolata and Acropora palmata symbioses. Here we report results from the initial steps in this microarray initiative, that is, the construction of cDNA libraries from 4 of 16 target stages, sequencing of 3450 cDNA clones to generate Expressed Sequenced Tags (ESTs), and annotation of the ESTs to identify candidate genes to include in the microarrays. An understanding of how the coral-dinoflagellate symbiosis is regulated will have implications for atmospheric and ocean sciences, conservation biology, the study and diagnosis of …
Date:
March 1, 2005
Creator:
Schwarz, Jodi; Brokstein, Peter; Manohar, Chitra; Coffroth, MaryAlice; Szmant, Alina & Medina, Monica
Object Type:
Article
System:
The UNT Digital Library
Users manual for CAFE-3D : a computational fluid dynamics fire code.
The Container Analysis Fire Environment (CAFE) computer code has been developed to model all relevant fire physics for predicting the thermal response of massive objects engulfed in large fires. It provides realistic fire thermal boundary conditions for use in design of radioactive material packages and in risk-based transportation studies. The CAFE code can be coupled to commercial finite-element codes such as MSC PATRAN/THERMAL and ANSYS. This coupled system of codes can be used to determine the internal thermal response of finite element models of packages to a range of fire environments. This document is a user manual describing how to use the three-dimensional version of CAFE, as well as a description of CAFE input and output parameters. Since this is a user manual, only a brief theoretical description of the equations and physical models is included.
Date:
March 1, 2005
Creator:
Khalil, Imane; Lopez, Carlos & Suo-Anttila, Ahti Jorma (Alion Science and Technology, Albuquerque, NM)
Object Type:
Report
System:
The UNT Digital Library
Physics of arcing, and implications to sputter deposition
Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or non-stationary with cold cathodes (cathodic arcs). A brief review on cathodic arc properties serves as the starting point to better understand arcing phenomena in sputtering. Although arcing occurs in both metal and reactive sputtering, it is more of an issue in the reactive case. Arcing occurs if sufficiently high field strength leads to thermal runaway of an electron emission site. The role of insulating layers and surface potential adjustment through current leakage is highlighted. In the situation of magnetron sputtering with ''racetrack'', the need for a model with two spatial dimensions is shown. In many cases, arcing is initiated by breakdown of dielectric layers and inclusions. It is most efficiently prevented if formation and excessive charge-up of dielectric layers and inclusions can be avoided.
Date:
March 15, 2005
Creator:
Anders, Andre
Object Type:
Article
System:
The UNT Digital Library
Use of Coal Drying to Reduce Water Consumed in Pulverized Coal Power Plants Quarterly Report: October-December 2004
This is the eighth Quarterly Report for this project. The background and technical justification for the project are described, including potential benefits of reducing fuel moisture, prior to firing in a pulverized coal boiler. Analyses were performed to determine the effects of coal product moisture on unit performance. Results are given showing how the coal product moisture level affects parameters such as boiler efficiency, power required to drive the fluidizing air fan, other station service power needed for fans and pulverizers, net unit heat rate, thermal energy rejected by the cooling tower, and stack emissions.
Date:
March 1, 2005
Creator:
Sarunac, Nenad & Levy, Edward
Object Type:
Report
System:
The UNT Digital Library
Detection and Tracking of the Back-Reflection of KDP Images in the Presence or Absence of a Phase Mask
The KDP crystals present in the final optics assembly at the National Ignition Facility (NIF) are used for conversion of infrared laser light beam into ultraviolet. The conversion is highest for a certain incident angle, the alignment of which is determined from the position of the back reflection beam, which exhibits a distinct characteristics shape. When a phase plate device is introduced before the final assembly to increase the uniformity of the beam, the back reflection pattern changes drastically. The algorithm which is best for tracking the special shaped beam is no longer suitable to track the phase modified beam. The work presented here discusses our detection schemes for both the situations. In particular, we demonstrate how the algorithm senses the modified beam using a newly proposed criterion of ''correlation peak pedestal area'' and execute an alternate algorithm in real time without operator intervention. This new algorithm continuously tracks the beam pattern to guarantee reliable and repeatable sensing. Results from simulation and real world implementation of the algorithm at the NIF facility are presented.
Date:
March 4, 2005
Creator:
Awwal, A.; McClay, W. A.; Ferguson, S. W.; Candy, J. V.; Salmon, J. T. & Wegner, P. J.
Object Type:
Article
System:
The UNT Digital Library
Glider communications and controls for the sea sentry mission.
This report describes a system level study on the use of a swarm of sea gliders to detect, confirm and kill littoral submarine threats. The report begins with a description of the problem and derives the probability of detecting a constant speed threat without networking. It was concluded that glider motion does little to improve this probability unless the speed of a glider is greater than the speed of the threat. Therefore, before detection, the optimal character for a swarm of gliders is simply to lie in wait for the detection of a threat. The report proceeds by describing the effect of noise on the localization of a threat once initial detection is achieved. This noise is estimated as a function of threat location relative to the glider and is temporally reduced through the use of an information or Kalman filtering. In the next section, the swarm probability of confirming and killing a threat is formulated. Results are compared to a collection of stationary sensors. These results show that once a glider has the ability to move faster than the threat, the performance of the swarm is equal to the performance of a stationary swarm of gliders with confirmation and …
Date:
March 1, 2005
Creator:
Feddema, John Todd & Dohner, Jeffrey Lynn
Object Type:
Report
System:
The UNT Digital Library
Statistical Analysis of Elevated Radium and Gross Alpha Measurements in the Sanitary Landfill
None
Date:
March 31, 2005
Creator:
Tuckfield, Richard
Object Type:
Report
System:
The UNT Digital Library
Field-Scale Effective Matrix Diffusion Coefficient for FracturedRock: Results From Literature Survey
Matrix diffusion is an important mechanism for solutetransport in fractured rock. We recently conducted a literature survey onthe effective matrix diffusion coefficient, Dem, a key parameter fordescribing matrix diffusion processes at the field scale. Forty fieldtracer tests at 15 fractured geologic sites were surveyed and selectedfor study, based on data availability and quality. Field-scale Dem valueswere calculated, either directly using data reported in the literature orby reanalyzing the corresponding field tracer tests. Surveyed dataindicate that the effective-matrix-diffusion-coefficient factor FD(defined as the ratio of Dem to the lab-scale matrix diffusioncoefficient [Dem]of the same tracer) is generally larger than one,indicating that the effective matrix diffusion coefficient in the fieldis comparatively larger than the matrix diffusion coefficient at therock-core scale. This larger value could be attributed to the manymass-transfer processes at different scales in naturally heterogeneous,fractured rock systems. Furthermore, we observed a moderate trend towardsystematic increase in the emDFmDDF value with observation scale,indicating that the effective matrix diffusion coefficient is likely tobe statistically scale dependent. The FD value ranges from 1 to 10,000for observation scales from 5 to 2,000 m. At a given scale, the FD valuevaries by two orders of magnitude, reflecting the influence of differingdegrees of fractured rock heterogeneity at different …
Date:
March 28, 2005
Creator:
Zhou, Quanlin; Liu, Hui Hai; Molz, Fred J.; Zhang, Yingqi & Bodvarsson, Gudmundur S.
Object Type:
Article
System:
The UNT Digital Library
Innovative applications of energy storage in a restructured electricity marketplace : Phase III final report : a study for the DOE Energy Storage Systems Program.
This report describes Phase III of a project entitled Innovative Applications of Energy Storage in a Restructured Electricity Marketplace. For this study, the authors assumed that it is feasible to operate an energy storage plant simultaneously for two primary applications: (1) energy arbitrage, i.e., buy-low-sell-high, and (2) to reduce peak loads in utility ''hot spots'' such that the utility can defer their need to upgrade transmission and distribution (T&D) equipment. The benefits from the arbitrage plus T&D deferral applications were estimated for five cases based on the specific requirements of two large utilities operating in the Eastern U.S. A number of parameters were estimated for the storage plant ratings required to serve the combined application: power output (capacity) and energy discharge duration (energy storage). In addition to estimating the various financial expenditures and the value of electricity that could be realized in the marketplace, technical characteristics required for grid-connected distributed energy storage used for capacity deferral were also explored.
Date:
March 1, 2005
Creator:
Eyer, James M.; Erdman, Bill & Iannucci, Joseph J., Jr.
Object Type:
Report
System:
The UNT Digital Library
Final report to NASA JSC : thermal abuse performance of MOLI, Panasonic and Sanyo 18650 Li-ion cells.
Thermal property measurements of 18650 cells for the Space Shuttle Orbiter Advanced Hydraulic Power System (AHPS, formerly known as EAPU) have been performed. Cells were measured from three commercial manufacturers: E-One MOLI (12 cells), Panasonic (5 cells) and Sanyo (5 cells). Thermal property measurements of the MOLI 18650 cells included measurements of specific heat, self discharge (microcalorimetry), overcharge response and thermal runaway by accelerating rate calorimetry (ARC). The Panasonic and Sanyo cells were measured only for thermal runaway response in the ARC at increasing states of charge (3.8V, 4.0V, 4.2V, 4.3V).
Date:
March 1, 2005
Creator:
Roth, Emanuel Peter
Object Type:
Report
System:
The UNT Digital Library
Revisiting the U-238 thermal capture cross section and gamma-raymission probabilities from Np-239 decay
The precise value of the thermal capture cross section of238U is uncertain, and evaluated cross sections from various sourcesdiffer by more than their assigned uncertainties. A number of theoriginal publications have been reviewed to assess the discrepant data,corrections were made for more recent standard cross sections andotherconstants, and one new measurement was analyzed. Due to the strongcorrelations in activation measurements, the gamma-ray emissionprobabilities from the beta decay of 239Np were also analyzed. As aresult of the analysis, a value of 2.683 +- 0.012 barns was derived forthe thermal capture cross section of 238U. A new evaluation of thegamma-ray emission probabilities from 239Np decay was alsoundertaken.
Date:
March 3, 2005
Creator:
Trkov, A.; Molnar, G. L.; Revay, Z. S.; Mughabghab, S. F.; Firestone, R. B.; Pronyaev, V. G. et al.
Object Type:
Article
System:
The UNT Digital Library
Low-cost inertial measurement unit.
Sandia National Laboratories performs many expensive tests using inertial measurement units (IMUs)--systems that use accelerometers, gyroscopes, and other sensors to measure flight dynamics in three dimensions. For the purpose of this report, the metrics used to evaluate an IMU are cost, size, performance, resolution, upgradeability and testing. The cost of a precision IMU is very high and can cost hundreds of thousands of dollars. Thus the goals and results of this project are as follows: (1) Examine the data flow in an IMU and determine a generic IMU design. (2) Discuss a high cost IMU implementation and its theoretically achievable results. (3) Discuss design modifications that would save money for suited applications. (4) Design and implement a low cost IMU and discuss its theoretically achievable results. (5) Test the low cost IMU and compare theoretical results with empirical results. (6) Construct a more streamlined printed circuit board design reducing noise, increasing capabilities, and constructing a self-contained unit. Using these results, we can compare a high cost IMU versus a low cost IMU using the metrics from above. Further, we can examine and suggest situations where a low cost IMU could be used instead of a high cost IMU for saving …
Date:
March 1, 2005
Creator:
Deyle, Travis Jay
Object Type:
Report
System:
The UNT Digital Library
Diamond-like nanocomposite coatings for LIGA-fabricated nickel alloy parts.
A commercial plasma enhanced chemical vapor deposition (PECVD) technique with planetary substrate rotation was used to apply a thin (200-400 nm thick) conformal diamond-like carbon (DLC) coating (known as a diamond-like nanocomposite (DLN)) on LIGA fabricated Ni-Mn alloy parts. The PECVD technique is known to overcome the drawbacks associated with the line-of-sight nature of physical vapor deposition (PVD) and substrate heating inherent with traditional chemical vapor deposition (CVD). The purpose of the present study is to characterize the coverage, adhesion, and tribological (friction and wear) behavior of DLN coatings applied to planar and sidewall surfaces of small featured LIGA Ni-Mn fabricated parts, e.g. 280 {micro}m thick sidewalls. Friction and wear tests were performed in dry nitrogen, dry air, and air with 50% RH at Hertzian contact pressures ranging from 0.3 to 0.6 GPa. The friction coefficient of bare Ni-Mn alloy was determined to be 0.9. In contrast, low friction coefficients ({approx}0.02 in dry nitrogen and {approx}0.2 in 50% RH air) and minimal amount of wear were exhibited for the DLN coated LIGA Ni-Mn alloy parts and test coupons. This behavior was due to the ability of the coating to transfer to the rubbing counterface providing low interfacial shear at the …
Date:
March 1, 2005
Creator:
Prasad, Somuri V. & Scharf, Thomas W.
Object Type:
Report
System:
The UNT Digital Library
Robust hermetic packaging techniques for MEMS integrated microsystems.
This work is the result of a Sandia National Laboratories LDRD funded fellowship at the University of Michigan. Although, guidance and suggestions were offered by Sandia, the work contained here is primarily the work of Brian H. Stark, and his advisor, Professor Khalil Najafi. Junseok Chae, Andrew Kuo, and their coworkers at the University of Michigan helped to record some of the data. The following is an abstract of their work. We have developed a vacuum packaging technology using a thick nickel film to seal MEMS structures at the wafer level. The package is fabricated in a three-mask process by electroplating a 40 micro-meter thick nickel film over an 8 micro-meter sacrificial photoresist that is removed prior to package sealing. Implementation of electrical feedthroughs in this process requires no planarization. The large release channel enables an 800x800 micro-meter package to be released in less than three hours. Several mechanisms, based upon localized melting and lead/tin solder bumping, for sealing the release channel have been investigated. We have also developed Pirani gauges, integrated with this package, which can be used to establish the hermeticity of the different sealing technologies. They have measured a sealing pressure of approximately 1.5 Torr. Our work …
Date:
March 1, 2005
Creator:
Chae, Junseok (University of Michigan); Stark, Brian H. (University of Michigan); Kuo, Andrew (University of Michigan); Oliver, Andrew David & Najafi, Khalil (University of Michigan)
Object Type:
Report
System:
The UNT Digital Library
Microcalibrator system for chemical signature and reagent delivery.
Networked systems of low-cost, small, integrable chemical sensors will enable monitoring of Nonproliferation and Materials Control targets and chemical weapons threats. Sandia-designed prototype chemical sensor systems are undergoing extended field testing supported by DOE and other government agencies. A required surety component will be verification of microanalytical system performance, which can be achieved by providing a programmable source of chemical signature(s) for autonomous calibration of analytical systems. In addition, such a controlled chemical source could be used to dispense microaliquots of derivatization reagents, extending the analysis capability of chemical sensors to a wider range of targets. We have developed a microfabricated system for controlled release of selected compounds (calibrants) into the analytical stream of microsensor systems. To minimize pumping and valve requirements of microfluidic systems, and to avoid degradation issues associated with storage of dilute solutions, we have utilized thermally labile organic salts as solid-phase reservoir materials. Reproducible deposition of tetrapropyl ammonium hydroxide onto arrays of microfabricated heating elements can provide a pair of calibration marker compounds (one fast and one slow-eluting compound) for GC analyses. The use of this microaliquot gas source array for hydrogen generation is currently under further development. The goal of the latter effort will be …
Date:
March 1, 2005
Creator:
Staton, Alan W.; Simonson, Robert Joseph; Adkins, Douglas Ray; Rawlinson, Kim Scott; Robinson, Alex Lockwood; Hance, Bradley G. et al.
Object Type:
Report
System:
The UNT Digital Library
An Integrated Modeling Analysis of Unsaturated Flow Patterns inFractured Rock
Characterizing percolation patterns in unsaturated zones hasposed a greater challenge to numerical modeling investigations thancomparable saturated zone studies, because of the heterogeneous nature ofunsaturated media as well as the great number of variables impactingunsaturated zone flow. This paper presents an integrated modelingmethodology for quantitatively characterizing percolation patterns in theunsaturated zone of Yucca Mountain, Nevada, a proposed undergroundrepository site for storing high-level radioactive waste. It takes intoaccount the multiple coupled processes of air, water, heat flow andchemical isotopic transport in Yucca Mountain s highly heterogeneous,unsaturated fractured tuffs. The modeling approach integrates a widevariety of moisture, pneumatic, thermal, and isotopic geochemical fielddata into a comprehensive three-dimensional numerical model for modelinganalyses. Modeling results are examined against different types offield-measured data and then used to evaluate different hydrogeologicalconceptual models and their results of flow patterns in the unsaturatedzone. In particular, this integration model provides a much clearerunderstanding of percolation patterns and flow behavior through theunsaturated zone, both crucial issues in assessing repositoryperformance. The integrated approach for quantifying Yucca Mountain sflow system is also demonstrated to provide a comprehensive modeling toolfor characterizing flow and transport processes in complex subsurfacesystems.
Date:
March 21, 2005
Creator:
Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua & Bodvarsson,Gudmundur S.
Object Type:
Article
System:
The UNT Digital Library
Deciphering the genetic regulatory code using an inverse error control coding framework.
We have found that developing a computational framework for reconstructing error control codes for engineered data and ultimately for deciphering genetic regulatory coding sequences is a challenging and uncharted area that will require advances in computational technology for exact solutions. Although exact solutions are desired, computational approaches that yield plausible solutions would be considered sufficient as a proof of concept to the feasibility of reverse engineering error control codes and the possibility of developing a quantitative model for understanding and engineering genetic regulation. Such evidence would help move the idea of reconstructing error control codes for engineered and biological systems from the high risk high payoff realm into the highly probable high payoff domain. Additionally this work will impact biological sensor development and the ability to model and ultimately develop defense mechanisms against bioagents that can be engineered to cause catastrophic damage. Understanding how biological organisms are able to communicate their genetic message efficiently in the presence of noise can improve our current communication protocols, a continuing research interest. Towards this end, project goals include: (1) Develop parameter estimation methods for n for block codes and for n, k, and m for convolutional codes. Use methods to determine error control …
Date:
March 1, 2005
Creator:
Rintoul, Mark Daniel; May, Elebeoba Eni; Brown, William Michael; Johnston, Anna Marie & Watson, Jean-Paul
Object Type:
Report
System:
The UNT Digital Library
Development of an efficient large-aperture high damage-threshold sol-gel diffraction grating.
In order to develop the next generation of high peak intensity lasers, new grating technology providing higher damage thresholds and large apertures is required. The current assumption is that this technical innovation will be multilayer dielectric gratings, wherein the uppermost layer of a thin film mirror is etched to create the desired binary phase grating. A variant of this is explored with the upper grating layer being a lower density gelatin-based volume phase grating in either sol-gel or dichromated gelatin. One key benefit is the elimination of the etching step.
Date:
March 1, 2005
Creator:
Ashley, Carol S.; Rambo, Patrick K.; Schwarz, Jens; Dunphy, Darren Robert; Branson, Eric D.; Smith, Ian Craig et al.
Object Type:
Report
System:
The UNT Digital Library
Increasing Production from Low-Permeability Gas Reservoirs by Optimizing Zone Isolation for Successful Stimulation Treatments
Maximizing production from wells drilled in low-permeability reservoirs, such as the Barnett Shale, is determined by cementing, stimulation, and production techniques employed. Studies show that cementing can be effective in terms of improving fracture effectiveness by 'focusing' the frac in the desired zone and improving penetration. Additionally, a method is presented for determining the required properties of the set cement at various places in the well, with the surprising result that uphole cement properties in wells destined for multiple-zone fracturing is more critical than those applied to downhole zones. Stimulation studies show that measuring pressure profiles and response during Pre-Frac Injection Test procedures prior to the frac job are critical in determining if a frac is indicated at all, as well as the type and size of the frac job. This result is contrary to current industry practice, in which frac jobs are designed well before the execution, and carried out as designed on location. Finally, studies show that most wells in the Barnett Shale are production limited by liquid invasion into the wellbore, and determinants are presented for when rod or downhole pumps are indicated.
Date:
March 31, 2005
Creator:
Sabins, Fred
Object Type:
Report
System:
The UNT Digital Library
CH-TRU Waste Content Codes (CH-TRUCON)
The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container. Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 …
Date:
March 15, 2005
Creator:
Westinghouse TRU Solutions LLC
Object Type:
Report
System:
The UNT Digital Library
AFM Morphology Study of Si1-Y GeY:H Films Deposited by LF PE CVD from Silane-Germane with Different
The morphology of Si{sub 1-Y} Ge{sub Y}:H films in the range of Y=0.23 to 0.9 has been studied by AFM. The films were deposited by Low Frequency (LF) PE CVD at substrate temperature T{sub s}=300 C and discharge frequency f=110 kHz from silane+germane mixture with and without, Ar and H{sub 2} dilution. The films were deposited on silicon and glass substrates. AFM images were taken and analyzed for 2 x 2 mm{sup 2} area. All the images demonstrated ''grain'' like structure, which was characterized by the height distribution function F(H) average roughness <H>, standard height deviation Rq, lateral correlation length L{sub c} area distribution function F(s), mean grain area <s>, diameter distribution function F(d), and mean grain diameter <d>. The roughness <H> of the films monotonically increases with Y for all dilutions, but more significantly in the films deposited without dilution. L{sub c} continuously grows with Y in the films deposited without dilution, while more complex behavior L{sub c}(Y) is observed in the films deposited with H- or Ar dilution. The sharpness of F(H) characterized by curtosis {gamma} depends on dilution and the sharpest F(H) are for the films deposited with Ar ({gamma}=5.30,Y=0.23) and without dilution ({gamma}=4.3, Y=0.45). Isothermal annealing …
Date:
March 28, 2005
Creator:
Sanchez, L & Kosarev, A
Object Type:
Article
System:
The UNT Digital Library
Restart of the chemical preparation process for the fabrication of ZnO varistors for ferroelectric neutron generator power supplies.
To date, all varistors used in ferroelectric neutron generators have been supplied from a single, proprietary source, General Electric Corporate Research and Development (GE CR&D). To protect against the vulnerability of a single source, Sandia initiated a program in the early 1980's to develop a second source for this material. A chemical preparation process for making homogeneous, high purity ZnO-based varistor powder was generated, scaled to production quantities, and transferred to external suppliers. In 1992, the chem-prep varistor program was suspended when it appeared there was sufficient inventory of GE CR&D material to supply ferroelectric neutron generator production for many years. In 1999, neutron generator production schedules increased substantially, resulting in a predicted exhaustion of the existing supply of varistor material within five years. The chem-prep program was restarted in January, 2000. The goals of the program were to (1) duplicate the chem-prep powder synthesis process that had been qualified for WR production, (2) demonstrate sintered billets from the chem-prep powder met requirements, (3) develop a process for rod fabrication and demonstrate that all component specifications could be met, and (4) optimize the process from powder synthesis through component fabrication for full-scale production. The first three of these goals have …
Date:
March 1, 2005
Creator:
Lockwood, Steven John
Object Type:
Report
System:
The UNT Digital Library
EMPHASIS/Nevada UTDEM user guide : version 1.0.
The Unstructured Time-Domain ElectroMagnetics (UTDEM) portion of the EMPHASIS suite solves Maxwell's equations using finite-element techniques on unstructured meshes. This document provides user-specific information to facilitate the use of the code for applications of interest.
Date:
March 1, 2005
Creator:
Turner, C. David; Seidel, David Bruce & Pasik, Michael Francis
Object Type:
Report
System:
The UNT Digital Library
ORNL/IAT ARMATURE DIAGNOSTICS DEMONSTRATION TEST REPORT
This test established feasibility for 'on the fly' temperature measurements of rail gun projectiles. In addition, an approach for projectile velocity measurement was also demonstrated. Insight was gained into other useful optical and fiberoptic diagnostic approaches. Instantaneous diagnostics could be critical for achieving further improvements in rail gun operation. They have the potential to enable design enhancements by providing information on the state of the armature and its relationship to the rail as it proceeds down the bore. To that end, the following was accomplished: (1) Optical fibers successfully delivered optical excitation and returned reflective and fluorescence signals as desired. (2) Luminescent coatings survived multiple firings--approximately 40 shots. (3) Optical triggering effectively synchronized an ultraviolet laser pulse to strike the moving armature. (4) Velocity measurements were successfully accomplished by either triggering on the armature front edge using two red diode lasers or by using a single laser and grooved marks a known distance apart on the armature surface. (5) Velocities ranged from 19 to 88 m/s. (6) Temperatures of 30 to 92 C were measured with a precision of about 2 C-: (a) This precision was achieved with a single laser shot and (b) Motion effect was observed but a …
Date:
March 1, 2005
Creator:
Allison, Stephen W; Cates, Michael R; Goedeke, Shawn; Crawford, M. T.; Ferraro, S. B. & Akerman, A.
Object Type:
Report
System:
The UNT Digital Library