Preliminary design of a cryogenic thermoelectric generator.

Preliminary design of a cryogenic thermoelectric generator.

Date: May 2007
Creator: Sivapurapu, Sai Vinay Kumar
Description: A cryogenic thermoelectric generator is proposed to increase the efficiency of a vehicle propulsion system that uses liquid nitrogen as its fuel. The proposed design captures some of the heat required for vaporizing or initial heating of the liquid nitrogen to produce electricity. The thermoelectric generator uses pressurized liquid nitrogen as its cold reservoir and ambient air as the high-temperature reservoir to generate power. This study concentrated on the selection of thermoelectric materials whose properties would result in the highest efficiency over the operating temperature range and on estimating the initial size of the generator. The preliminary selection of materials is based upon their figure of merit at the operating temperatures. The results of this preliminary design investigation of the cryogenic thermoelectric generator indicate that sufficient additional energy can be used to increase overall efficiency of the thermodynamic cycle of a vehicle propulsion system.
Contributing Partner: UNT Libraries
Feminist Design Methodology: Considering the Case of Maria Kipp

Feminist Design Methodology: Considering the Case of Maria Kipp

Date: December 2003
Creator: Lawrence, Anne
Description: This thesis uses the work and career of the textile designer Maria Kipp to stage a prolegomena concerning how to write about a female designer active during the middle of the twentieth century. How can design historians incorporate new methodologies in the writing of design history? This thesis explores the current literature of feminist design history for solutions to the potential problems of the traditional biography and applies these to the work and career of Kipp. It generates questions concerning the application of methodologies, specifically looking at a biographical methodology and new methodologies proposed by feminist design historians. Feminist writers encourage scholarship on unknown designers, while also they call for a different kind of writing and methodology. The goal of this thesis is to examine how these new histories are written and in what ways they might inspire the writing of Kipp into design history.
Contributing Partner: UNT Libraries
Modeling patterns in count data using loglinear and related models

Modeling patterns in count data using loglinear and related models

Date: December 1, 1995
Creator: Atwood, C.L.
Description: This report explains the use of loglinear and logit models, for analyzing Poisson and binomial counts in the presence of explanatory variables. The explanatory variables may be unordered categorical variables or numerical variables, or both. The report shows how to construct models to fit data, and how to test whether a model is too simple or too complex. The appropriateness of the methods with small data sets is discussed. Several example analyses, using the SAS computer package, illustrate the methods.
Contributing Partner: UNT Libraries Government Documents Department
Welding the AT-400A Containment Vessel

Welding the AT-400A Containment Vessel

Date: November 1, 1998
Creator: Brandon, E.
Description: Early in 1994, the Department of Energy assigned Sandia National Laboratories the responsibility for designing and providing the welding system for the girth weld for the AT-400A containment vessel. (The AT-400A container is employed for the shipment and long-term storage of the nuclear weapon pits being returned from the nation's nuclear arsenal.) Mason Hanger Corporation's Pantex Plant was chosen to be the production facility. The project was successfully completed by providing and implementing a turnkey welding system and qualified welding procedure at the Pantex Plant. The welding system was transferred to Pantex and a pilot lot of 20 AT-400A containers with W48 pits was welded in August 1997. This document is intended to bring together the AT-400A welding system and product (girth weld) requirements and the activities conducted to meet those requirements. This document alone is not a complete compilation of the welding development activities but is meant to be a summary to be used with the applicable references.
Contributing Partner: UNT Libraries Government Documents Department
Feasibility of an anticipatory noncontact precrash restraint actuation system

Feasibility of an anticipatory noncontact precrash restraint actuation system

Date: December 31, 1995
Creator: Kercel, S.W. & Dress, W.B.
Description: The problem of providing an electronic warning of an impending crash to a precrash restraint system a fraction of a second before physical contact differs from more widely explored problems, such as providing several seconds of crash warning to a driver. One approach to precrash restraint sensing is to apply anticipatory system theory. This consists of nested simplified models of the system to be controlled and of the system`s environment. It requires sensory information to describe the ``current state`` of the system and the environment. The models use the sensory data to make a faster-than-real-time prediction about the near future. Anticipation theory is well founded but rarely used. A major problem is to extract real-time current-state information from inexpensive sensors. Providing current-state information to the nested models is the weakest element of the system. Therefore, sensors and real-time processing of sensor signals command the most attention in an assessment of system feasibility. This paper describes problem definition, potential ``showstoppers,`` and ways to overcome them. It includes experiments showing that inexpensive radar is a practical sensing element. It considers fast and inexpensive algorithms to extract information from sensor data.
Contributing Partner: UNT Libraries Government Documents Department
Low-cost automated fiber pigtailing machine. Revision 1

Low-cost automated fiber pigtailing machine. Revision 1

Date: January 1, 1996
Creator: Strand, O.T.
Description: The goal of this 2-year ARPA-funded project was to design and build 3 low-cost machines to perform sub-micron alignment and attachments of single-mode fibers to different OE devices. These Automated Fiber Pigtailing Machines (AFPMs) are intended to be compatible with a manufacturing environment and have a modular design for maximum flexibility and standardization of parts. Machine vision enables the AFPM to perform sufficient alignment to couple light for maximization. This work was a collaboration among Uniphase Telecommunications Products (formerly United Technologies Photonics, UTP), Ortel, Newport/Klinger, the Massachusetts Institute of Technology Manufacturing Institute (MIT), and Lawrence Livermore National Laboratory (LLNL). UTP and Ortel are the industrial partners for whom two of the AFPMs were built. MIT and LLNL made up the design and assembly team of the project, while Newport/Klinger was a potential manufacturer of the AFPM and provided guidance to ensure that the design of the AFPM is marketable and compatible with a manufacturing environment. The AFPM for UTP pigtails LiNbO{sub 3} waveguide devices and the AFPM for Ortel pigtails photodiodes. Both of these machines contain proprietary information, so the third AFPM, residing at LLNL, pigtails a non-proprietary waveguide device for demonstrations to US industry and further development.
Contributing Partner: UNT Libraries Government Documents Department
Guidelines for preparing and reviewing applications for the licensing of non-power reactors: Standard review plan and acceptance criteria. NUREG - 1537, Part 2

Guidelines for preparing and reviewing applications for the licensing of non-power reactors: Standard review plan and acceptance criteria. NUREG - 1537, Part 2

Date: February 1, 1996
Creator: unknown
Description: NUREG - 1537, Part 2 gives guidance on the conduct of licensing action reviews to NRC staff who review non-power reactor licensing applications. These licensing actions include construction permits and initial operating licenses, license renewals, amendments, conversions from highly enriched uranium to low-enriched uranium, decommissioning, and license termination.
Contributing Partner: UNT Libraries Government Documents Department
Comparison of damage identification algorithms on experimental modal data from a bridge

Comparison of damage identification algorithms on experimental modal data from a bridge

Date: December 31, 1995
Creator: Jauregui, D.V. & Farrar, C.R.
Description: Over the past 25 years detecting damage in a structure from changes in dynamic parameters has received a considerable amount of attention from the aerospace, civil, and mechanical engineering communities. The general idea is that changes in the structure`s physical properties (i.e., stiffness, mass, and/or damping) will, in turn, alter the dynamic characteristics (i.e., resonant frequencies, modal damping, and mode shapes) of the structure. Properties such as the flexibility matrix, stiffness matrix, and mode shape curvature, which are obtained from modal parameters, have shown promise for localizing structural damage. In this paper, several different techniques for damage assessment are demonstrated and compared using experimental modal data from an undamaged and damaged bridge.
Contributing Partner: UNT Libraries Government Documents Department
Solar Heat-Pipe Receiver Wick Modeling

Solar Heat-Pipe Receiver Wick Modeling

Date: December 21, 1998
Creator: Andraka, C.E.
Description: Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. In previous experimented work, we have demonstrated that a heat pipe receiver can significantly improve system performance-over a directly-illuminated heater head. The design and operating conditions of a heat pipe receiver differ significantly from typical laboratory heat pipes. New wick structures have been developed to exploit the characteristics of the solar generation system. Typically, these wick structures allow vapor generation within the wick. Conventional heat pipe models do not handle this enhancement yet it can more than double the performance of the wick. In this study, I develop a steady-state model of a boiling-enhanced wick for a solar heat pipe receiver. The model is used for design-point calculations and is written in FORTRAN90. Some limited comparisons have been made with actual test data.
Contributing Partner: UNT Libraries Government Documents Department
Workshop on rock mechanics issues in repository design and performance assessment

Workshop on rock mechanics issues in repository design and performance assessment

Date: April 1, 1996
Creator: unknown
Description: The Center for Nuclear Waste Regulatory Analyses organized and hosted a workshop on ``Rock Mechanics Issues in Repository Design and Performance Assessment`` on behalf its sponsor the U.S. Nuclear Regulatory Commission (NRC). This workshop was held on September 19- 20, 1994 at the Holiday Inn Crowne Plaza, Rockville, Maryland. The objectives of the workshop were to stimulate exchange of technical information among parties actively investigating rock mechanics issues relevant to the proposed high-level waste repository at Yucca Mountain and identify/confirm rock mechanics issues important to repository design and performance assessment The workshop contained three technical sessions and two panel discussions. The participants included technical and research staffs representing the NRC and the Department of Energy and their contractors, as well as researchers from the academic, commercial, and international technical communities. These proceedings include most of the technical papers presented in the technical sessions and the transcripts for the two panel discussions. Selected papers have been indexed separately for inclusion the Energy Science and Technology Database.
Contributing Partner: UNT Libraries Government Documents Department
FIRST PREV 1 2 3 4 5 NEXT LAST