Control of a high beta maneuvering reentry vehicle using dynamic inversion. (open access)

Control of a high beta maneuvering reentry vehicle using dynamic inversion.

The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to perform the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for …
Date: May 1, 2005
Creator: Watts, Alfred Chapman
Object Type: Report
System: The UNT Digital Library
Condition monitoring through advanced sensor and computational technology : final report (January 2002 to May 2005). (open access)

Condition monitoring through advanced sensor and computational technology : final report (January 2002 to May 2005).

The overall goal of this joint research project was to develop and demonstrate advanced sensors and computational technology for continuous monitoring of the condition of components, structures, and systems in advanced and next-generation nuclear power plants (NPPs). This project included investigating and adapting several advanced sensor technologies from Korean and US national laboratory research communities, some of which were developed and applied in non-nuclear industries. The project team investigated and developed sophisticated signal processing, noise reduction, and pattern recognition techniques and algorithms. The researchers installed sensors and conducted condition monitoring tests on two test loops, a check valve (an active component) and a piping elbow (a passive component), to demonstrate the feasibility of using advanced sensors and computational technology to achieve the project goal. Acoustic emission (AE) devices, optical fiber sensors, accelerometers, and ultrasonic transducers (UTs) were used to detect mechanical vibratory response of check valve and piping elbow in normal and degraded configurations. Chemical sensors were also installed to monitor the water chemistry in the piping elbow test loop. Analysis results of processed sensor data indicate that it is feasible to differentiate between the normal and degraded (with selected degradation mechanisms) configurations of these two components from the acquired …
Date: May 1, 2005
Creator: Kim, Jung-Taek (Korea Atomic Energy Research Institute, Daejon, Korea) & Luk, Vincent K.
Object Type: Report
System: The UNT Digital Library
Effective Supergravity from the Weakly Coupled HeteroticString (open access)

Effective Supergravity from the Weakly Coupled HeteroticString

The motivation for Calabi-Yau-like compactifications of the weakly coupled E{sub 8} {circle_times} E{sub 8} heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R-parity, are discussed.
Date: May 1, 2005
Creator: Gaillard, Mary K.
Object Type: Article
System: The UNT Digital Library
CH-TRU Waste Content Codes (CH-TRUCON) (open access)

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: May 1, 2005
Creator: Westinghouse TRU Solutions LLC
Object Type: Report
System: The UNT Digital Library
An analytical and computational study of combined rate and size effects on material properties. (open access)

An analytical and computational study of combined rate and size effects on material properties.

The recent interests in developing multiscale model-based simulation procedures have brought about the challenging tasks of bridging different spatial and temporal scales within a unified framework. However, the research focus has been on the scale effect in the spatial domain with the loading rate being assumed to be quasi-static. Although material properties are rate-dependent in nature, little has been done in understanding combined loading rate and specimen size effects on the material properties at different scales. In addition, the length and time scales that can be probed by the molecular level simulations are still fairly limited due to the limitation of computational capability. Based on the experimental and computational capabilities available, therefore, an attempt is made in this report to formulate a hyper-surface in both spatial and temporal domains to predict combined size and rate effects on the mechanical properties of engineering materials. To demonstrate the features of the proposed hyper-surface, tungsten specimens of various sizes under various loading rates are considered with a focus on the uniaxial loading path. The mechanical responses of tungsten specimens under other loading paths are also explored to better understand the size effect. It appears from the preliminary results that the proposed procedure might …
Date: May 1, 2005
Creator: Fang, Huei Eliot; Chen, Zhen (University of Missouri-Columbia, Columbia, MO); Shen, Luming () University of Missouri-Columbia, Columbia, MO) & Gan, Yong (University of Missouri-Columbia, Columbia, MO)
Object Type: Report
System: The UNT Digital Library
Development and Validation of High-Resolution State Wind Resource Maps for the United States (Poster) (open access)

Development and Validation of High-Resolution State Wind Resource Maps for the United States (Poster)

A poster presentation for AWEA's WindPower 2005 conference in Denver, Colorado, May 15 -18, 2005 that provides an outline of the approach and process used for validating U.S. wind resource maps.
Date: May 1, 2005
Creator: Elliott, D. & Schwartz, M.
Object Type: Article
System: The UNT Digital Library
Laser Guiding at Relativistic Intensities and Wakefield ParticleAcceleration in Plasma Channels (open access)

Laser Guiding at Relativistic Intensities and Wakefield ParticleAcceleration in Plasma Channels

High quality electron beams with hundreds of picoCoulombs ofcharge inpercent energy spread above 80 MeV were produced for the firsttime in high gradient laser wakefield accelerators by guiding the drivelaser pulse.
Date: May 1, 2005
Creator: Geddes, C. G. R.; Toth, Cs.; van Tilborg, J.; Esarey, E.; Schroeder, C. B.; Bruhwiler, D. et al.
Object Type: Article
System: The UNT Digital Library
Macro-System Model (Poster) (open access)

Macro-System Model (Poster)

Poster presentation on Macro-System Model for the 2005 Hydrogen, Fuel Cells & Infrastructure Technologies Program Annual Review held in Arlington, Virginia on May 23-26, 2005
Date: May 1, 2005
Creator: Ruth, M.
Object Type: Article
System: The UNT Digital Library
The effects of process parameters on injection-molded PZT ceramics part fabrication- compounding process rheology. (open access)

The effects of process parameters on injection-molded PZT ceramics part fabrication- compounding process rheology.

Solid solutions of lead-based perovskites are the backbone materials of the piezoelectric components for transducer, actuator, and resonator applications. These components, typically small in size, are fabricated from large sintered ceramic slugs using grinding and lapping processes. These operations increase manufacturing costs and produce a large hazardous waste stream, especially when component size decreases. To reduce costs and hazardous wastes associated with the production of these components, an injection molding technique is being investigated to replace the machining processes. The first step in the new technique is to compound an organic carrier with a ceramic powder. The organic carrier is a thermoplastic based system composed of a main carrier, a binder, and a surfactant. Understanding the rheology of the compounded material is necessary to minimize the creation of defects such as voids or cavities during the injection-molding process. An experiment was performed to model the effects of changes in the composition and processing of the material on the rheological behavior. Factors studied included: the surfactant of the organic carrier system, the solid loading of the compounded material, and compounding time. The effects of these factors on the viscosity of the material were investigated.
Date: May 1, 2005
Creator: Halbleib, Laura L.; Yang, Pin; Mondy, Lisa Ann & Burns, George Robert
Object Type: Report
System: The UNT Digital Library
2005 Research Briefs : Materials and Process Sciences Center. (open access)

2005 Research Briefs : Materials and Process Sciences Center.

This report is the latest in a continuing series that highlights the recent technical accomplishments associated with the work being performed within the Materials and Process Sciences Center. Our research and development activities primarily address the materials-engineering needs of Sandia's Nuclear-Weapons (NW) program. In addition, we have significant efforts that support programs managed by the other laboratory business units. Our wide range of activities occurs within six thematic areas: Materials Aging and Reliability, Scientifically Engineered Materials, Materials Processing, Materials Characterization, Materials for Microsystems, and Materials Modeling and Simulation. We believe these highlights collectively demonstrate the importance that a strong materials-science base has on the ultimate success of the NW program and the overall DOE technology portfolio.
Date: May 1, 2005
Creator: Cieslak, Michael J.
Object Type: Report
System: The UNT Digital Library
LIMITS OF Nb3Sn ACCELERATOR MAGNETS (open access)

LIMITS OF Nb3Sn ACCELERATOR MAGNETS

Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Tevatron at Fermilab and the LHC at CERN. Exceeding the current density limits of NbTi superconductor, Nb{sub 3}Sn is at present the only practical superconductor capable of generating fields beyond 10 T. Several Nb{sub 3}Sn pilot magnets, with fields as high as 16 T, have been built and tested, paving the way for future attempts at fields approaching 20 T. High current density conductor is required to generate high fields with reduced conductor volume. However this significantly increases the Lorentz force and stress. Future designs of coils and structures will require managing stresses of several 100's of MPa and forces of 10's of MN/m. The combined engineering requirements on size and cost of accelerator magnets will involve magnet technology that diverges from the one currently used with NbTi conductor. In this paper we shall address how far the engineering of high field magnets can be pushed, and what are the issues and limitations before such magnets can be used in particle accelerators.
Date: May 1, 2005
Creator: Caspi, Shlomo & Ferracin, Paolo
Object Type: Article
System: The UNT Digital Library
Burn site groundwater interim measures work plan. (open access)

Burn site groundwater interim measures work plan.

This Work Plan identifies and outlines interim measures to address nitrate contamination in groundwater at the Burn Site, Sandia National Laboratories/New Mexico. The New Mexico Environment Department has required implementation of interim measures for nitrate-contaminated groundwater at the Burn Site. The purpose of interim measures is to prevent human or environmental exposure to nitrate-contaminated groundwater originating from the Burn Site. This Work Plan details a summary of current information about the Burn Site, interim measures activities for stabilization, and project management responsibilities to accomplish this purpose.
Date: May 1, 2005
Creator: Witt, Jonathan L. (North Wind, Inc., Idaho Falls, ID) & Hall, Kevin A. (North Wind, Inc., Idaho Falls, ID)
Object Type: Report
System: The UNT Digital Library
An Assessment of Radiation Damage Models and Methods (open access)

An Assessment of Radiation Damage Models and Methods

The current state of development of the primary models used for investigating and simulating irradiation effects in structural alloys of interest to the U.S. DOE's Generation-IV reactor program are discussed. The underlying theory that supports model development is also described where appropriate. First, the key processes that underlie radiation-induced changes in material properties are summarized, and the types of radiation effects that subsequently arise are described. Future development work needed in order for theory, modeling, and computational materials science to support and add value to the Gen IV reactor materials program are then outlined. The expected specific outcomes and overall benefits of the required effort are: the knowledge to extrapolate material behavior to conditions for which there are no experimental data; systematic understanding of mechanisms and processes to enable confident interpolation between point-by-point experimental observations; acceleration of the development, selection, and qualification of materials for reactor service; and prediction of material response to real-world operating load histories which often involve a complicated superposition of time, temperature, radiation dose rate, and mechanical loading conditions. Opportunities for international collaboration to accelerate progress in all of the required research areas are briefly discussed, particularly in the context of two well coordinated, broad-based research …
Date: May 1, 2005
Creator: Stoller, Roger E. & Mansur, Louis K.
Object Type: Report
System: The UNT Digital Library
Final report on Weeks Island Monitoring Phase : 1999 through 2004. (open access)

Final report on Weeks Island Monitoring Phase : 1999 through 2004.

This Final Report on the Monitoring Phase of the former Weeks Island Strategic Petroleum Reserve crude oil storage facility details the results of five years of monitoring of various surface accessible quantities at the decommissioned facility. The Weeks Island mine was authorized by the State of Louisiana as a Strategic Petroleum Reserve oil storage facility from 1979 until decommissioning of the facility in 1999. Discovery of a sinkhole over the facility in 1992 with freshwater inflow to the facility threatened the integrity of the oil storage and led to the decision to remove the oil, fill the chambers with brine, and decommission the facility. Thereafter, a monitoring phase, by agreement between the Department of Energy and the State, addressed facility stability and environmental concerns. Monitoring of the surface ground water and the brine of the underground chambers from the East Fill Hole produced no evidence of hydrocarbon contamination, which suggests that any unrecovered oil remaining in the underground chambers has been contained. Ever diminishing progression of the initial major sinkhole, and a subsequent minor sinkhole, with time was verification of the response of sinkholes to filling of the facility with brine. Brine filling of the facility ostensively eliminates any further …
Date: May 1, 2005
Creator: Ehgartner, Brian L. & Munson, Darrell Eugene
Object Type: Report
System: The UNT Digital Library
Pseudo-stationary separation materials for highly parallel separations. (open access)

Pseudo-stationary separation materials for highly parallel separations.

Goal of this study was to develop and characterize novel polymeric materials as pseudostationary phases in electrokinetic chromatography. Fundamental studies have characterized the chromatographic selectivity of the materials as a function of chemical structure and molecular conformation. The selectivities of the polymers has been studied extensively, resulting in a large body of fundamental knowledge regarding the performance and selectivity of polymeric pseudostationary phases. Two polymers have also been used for amino acid and peptide separations, and with laser induced fluorescence detection. The polymers performed well for the separation of derivatized amino acids, and provided some significant differences in selectivity relative to a commonly used micellar pseudostationary phase. The polymers did not perform well for peptide separations. The polymers were compatible with laser induced fluorescence detection, indicating that they should also be compatible with chip-based separations.
Date: May 1, 2005
Creator: Singh, Anup K. & Palmer, Christopher (University of Montana, Missoula, MT)
Object Type: Report
System: The UNT Digital Library
Building America Research is Leading the Way to Zero Energy Homes (open access)

Building America Research is Leading the Way to Zero Energy Homes

During times of peak demand, a near zero energy home generates more power than it uses and reduces power demand on the utility provider. In a Florida study, a prototype near zero energy home outperforms a conventional model by providing most of its own power needs throughout the year.
Date: May 1, 2005
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Analysis of the Use of Wind Energy to Supplement the Power Needs at McMurdo Station and Amundsen-Scott South Pole Station, Antarctica (open access)

Analysis of the Use of Wind Energy to Supplement the Power Needs at McMurdo Station and Amundsen-Scott South Pole Station, Antarctica

This report summarizes an analysis of the inclusion of wind-driven power generation technology into the existing diesel power plants at two U.S. Antarctic research stations, McMurdo and Amundsen-Scott South Pole Station. Staff at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) conducted the analysis. Raytheon Polar Services, which currently holds the private sector support contract for the two research stations, was a major contributor to this report. To conduct the analysis, available data were obtained on the wind resources, power plant conditions, load, and component cost. Whenever possible, we validated the information. We then used NREL's Hybrid2 power system modeling software to analyze the potential and cost of using wind turbine generators at the two aforementioned facilities. Unfortunately, the power systems and energy allocations at McMurdo and South Pole Station are being redeveloped, so it is not possible to validate future fuel use. This report is an initial assessment of the potential use of wind energy and should be followed by further, more detailed analysis if this option is to be considered further.
Date: May 1, 2005
Creator: Baring-Gould, I.; Robichaud, R. & McLain, K.
Object Type: Report
System: The UNT Digital Library
Fitting the luminosity decay in the Tevatron (open access)

Fitting the luminosity decay in the Tevatron

This paper explores how to fit the decay of the luminosity in the Tevatron. The standard assumptions of a fixed-lifetime exponential decay are only appropriate for very short time intervals. A ''1/time'' functional form fits well, and is supported by analytical derivations. A more complex form, assuming a time-varying lifetime-like term, also produces good results. Changes in the luminosity can be factored into two phenomena: The luminosity burn-off rate, and the burn-off rate from non-luminosity effects. This is particularly relevant for the antiprotons in the Tevatron. The luminous and the non-luminous burn rate of the antiprotons are shown for Tevatron stores.
Date: May 1, 2005
Creator: McCrory, E.; Shiltsev, V.; Slaughter, A. J. & Xiao, A.
Object Type: Article
System: The UNT Digital Library
Using star tracks to determine the absolute pointing of the Fluorescence Detector telescopes of the Pierre Auger Observatory (open access)

Using star tracks to determine the absolute pointing of the Fluorescence Detector telescopes of the Pierre Auger Observatory

To accurately reconstruct a shower axis from the Fluorescence Detector data it is essential to establish with high precision the absolute pointing of the telescopes. To d that they calculate the absolute pointing of a telescope using sky background data acquired during regular data taking periods. The method is based on the knowledge of bright star's coordinates that provide a reliable and stable coordinate system. it can be used to check the absolute telescope's pointing and its long-term stability during the whole life of the project, estimated in 20 years. They have analyzed background data taken from January to October 2004 to determine the absolute pointing of the 12 telescopes installed both in Los Leones and Coihueco. The method is based on the determination of the mean-time of the variance signal left by a star traversing a PMT's photocathode which is compared with the mean-time obtained by simulating the track of that star on the same pixel.
Date: May 1, 2005
Creator: De Donato, Cinzia; Sanchez, Federico; /Milan U. /INFN, Milan; Santander, Marcos; Natl.Tech.U., San Rafael; Camin, Daniel et al.
Object Type: Article
System: The UNT Digital Library
Advances in the understanding and operations of superconducting colliders (open access)

Advances in the understanding and operations of superconducting colliders

Chromaticity drift during injection is a well-known phenomenon in superconducting colliders, such as the Tevatron, HERA and RHIC. Imperfect compensation of the drift effects can contribute to beam loss and emittance growth. It is caused by the drift of the sextupole component in the dipole magnets due to current redistribution in its superconducting coils. Recently extensive studies of chromaticity drift were conducted at the Tevatron, aiming at the improvement of the luminosity performance in the ongoing run II. These studies included not only beam experiments, but also extensive off-line magnetic measurements on spare Tevatron dipoles. Less known, until recently, is that chromaticity drift is often accompanied by tune and coupling drift. This was recently discovered in the Tevatron. We believe that these effects are the product of systematic beam offset in conjunction with the sextupole drifts (and their compensation in the chromaticity correctors). These discoveries are most relevant to the upcoming LHC, where the drift effects will have even more dramatic consequences given the high beam current. It is therefore not a surprise that CERN has been the source of major advances in the understanding of dynamic effects during the LHC superconducting magnet development. The following will briefly review the …
Date: May 1, 2005
Creator: Annala, G.; Bauer, P.; Bottura, L.; Martens, M. A.; Sammut, N.; Velev, G. et al.
Object Type: Article
System: The UNT Digital Library
US accelerator contribution to the LHC (open access)

US accelerator contribution to the LHC

In 1998, the United States entered into an agreement with CERN to help build the Large Hadron Collider (LHC), with contributions to the accelerator and to the large HEP detectors. To accomplish this, the US LHC Accelerator Project was formed, encompassing expertise from Brookhaven National Laboratory (BNL), Fermi National Accelerator Laboratory (FNAL) and the Lawrence Berkeley National Laboratory (LBNL). This report is a summary of these contributions including the progress towards project completion, as well as a discussion of future plans for continued US participation in the LHC accelerator.
Date: May 1, 2005
Creator: Lamm, Michael J.
Object Type: Article
System: The UNT Digital Library
Field quality study in Nb(3)Sn accelerator magnets (open access)

Field quality study in Nb(3)Sn accelerator magnets

Four nearly identical Nb{sub 3}Sn dipole models of the same design were built and tested at Fermilab. It provided a unique opportunity of systematic study the field quality effects in Nb{sub 3}Sn accelerator magnets. The results of these studies are reported in the paper.
Date: May 1, 2005
Creator: Kashikhin, V. V.; Ambrosio, G.; Andreev, N.; Barzi, E.; Bossert, R.; DiMarco, J. et al.
Object Type: Article
System: The UNT Digital Library
Clean Cities Now, Vol. 9, No. 2 - May 2005 (open access)

Clean Cities Now, Vol. 9, No. 2 - May 2005

Monthly electronic newsletter features success stories, coalition news, upcoming events, a coordinator profile and an article on technical assistance.
Date: May 1, 2005
Creator: unknown
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library

Hydrogen Transition Infrastructure Analysis

Presentation for the 2005 U.S. Department of Energy Hydrogen Program review analyzes the hydrogen infrastructure needed to accommodate a transitional hydrogen fuel cell vehicle demand.
Date: May 1, 2005
Creator: Melendez, M. & Milbrandt, A.
Object Type: Presentation
System: The UNT Digital Library