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Butyl rubber O-ring seals: Revision of test procedures for stockpile materials

Description: Extensive testing showed little correlation between test slab and O-ring performance. New procedures, comparable to those used with the traditional test slabs, were defined for hardness, compression set, and tensile property testing on sacrificial O-ring specimens. Changes in target performance values were made as needed and were, in one case, tightened to reflect the O-ring performance data. An additional study was carried out on O-ring and slab performance vs cure cycle and showed little sensitivity of material performance to large changes in curing time. Aging and spectra of certain materials indicated that two sets of test slabs from current vendor were accidently made from EPDM rather than butyl rubber. Random testing found no O-rings made from EPDM. As a result, and additional spectroscope test will be added to the product acceptance procedures to verify the type of rubber compound used.
Date: December 1, 1996
Creator: Domeier, L.A. & Wagter, K.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

A Method for Achieving Constant Rotation Rates in a Micro-Orthogonal Linkage System

Description: Silicon micromachine designs include engines that consist of orthog- onally oriented linear comb drive actuators mechanically connected to a rotating gear. These gears are as small as 50 {micro}m in diameter and can be driven at rotation rates exceeding 300,000 rpm. Generally, these en- gines will run with non-uniform rotation rates if the drive signals are not properly designed and maintained over a range of system parameters. We present a method for producing constant rotation rates in a micro-engine driven by an orthogonal linkage system. We show that provided the val- ues of certain masses, springs, damping factors, and lever arms are in the right proportions, the system behaves as though it were symmetrical. We will refer to systems built in this way as being quasi-symmetrical. We show that if a system is built quasi-symmetrically , then it is possible to achieve constant rotation rates even if one does not know the form of the friction function, or the value of the friction. We analyze this case in some detail.
Date: May 12, 1999
Creator: Dickey, F.M.; Holswade, S.C. & Romero, L.A.
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Partner: UNT Libraries Government Documents Department

Series fault limiting resistors for Atlas Marx modules

Description: The proposed Atlas design provides a current pulse to the experiment chamber from a set of 20, 3-Marx-unit-wide modules radially positioned around a retangular disk transmission-line system (total of 60 Marxes in parallel){sup 1}. The Atlas circuit is designed to be near-critically-damped network with a total erected capacitance of 200 {mu}F at 600 KV. The justification for the necessary circuit resistance in this approach is based on reliability, fault tolerance and operational maintenance{sup 1}. Also the use of high energy- density capacitors that have lower tolerance to voltage reversal is a primary reason for the damping provided by significant series resistance. To obtain the damping there are two system resistors in the Atlas design. One resistor is a shunt element designed to damp the resonance caused by the relatively high-Q disk transmission-line capacitance and the Marx bank inductance. The second, more significant resistor is a series, fault-current limiting element that also performs the necessary damping for voltage reversal at the bank capacitors. The Series resistor is the subject of this paper.
Date: September 1, 1995
Creator: Thompson, C.; Bowman, D.; Gribble, R.F.; Griego, J.; Hinckley, W.B.; Kasik, R.J. et al.
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Partner: UNT Libraries Government Documents Department

Driving pockels cells using avalanche transistor pulsers

Description: The purpose of this paper is to describe the current state of avalanche transistor based Pockels cell driver development at LLNL and to provide the reader with a set of useful design guidelines. A general description of the units is followed by a short section on the circuit design of avalanche transistor pulsers. A more detailed design guide is given. Techniques for delivering either {1/4} or {1/2} wave voltages to a Pockels cell are covered. Recently these units have been modified for use at repetition rates up to 10kHz. Operating at high repetition rates represents problems for both the driver and the Pockels Cell. Design solutions for the pulser are presented as well as discussion of Pockels cell acoustic resonance.
Date: May 28, 1997
Creator: Fulkerson, E. S.; Norman, D. C. & Booth, R.
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Partner: UNT Libraries Government Documents Department

Individual software plan for the programmable logic controller

Description: This document defines the software quality assurance plan (SQAP) as it shall be applied to the development of the monitor and control system for the Integrated Corrosion Facility (ICF). The purpose of this SQA plan is to provide guidance to the development team in software quality and associated documentation.
Date: July 28, 1997
Creator: Green, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Buoyancy-generated variable-density turbulence

Description: Both a one-point (engineering) and a two-point (spectral) model are tested against numerical data. Deficiencies in these variable-density models are disucssed and modifications are suggested. Attention is restricted to turbulent interactions of two miscible, incompressible Newtonian fluids of different densities. Departures from the limits of validity of the Boussinesq approximation are examined. Results of the buoyancy-generated turbulence are compared with variable-density model predictions. 3 figs, 6 refs.
Date: June 1, 1996
Creator: Sandoval, D.L.; Clark, T.T. & Riley, J.J.
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Partner: UNT Libraries Government Documents Department

1.8.3 Site system engineering FY 1997 program plan

Description: The FY 1997 Multi-Year Work Plan (MYWP) technical baseline describes the functions to be accomplished and the technical standards that govern the work. The following information is provided in this FY 1997 MYWP: technical baseline, work breakdown structure, schedule baseline, cost baseline, and execution year.
Date: September 13, 1996
Creator: Grygiel, M. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Tank 241-T-201, core 192 analytical results for the final report

Description: This document is the final laboratory report for Tank 241-T-201. Push mode core segments were removed from Riser 3 between April 24, 1997, and April 25, 1997. Segments were received and extruded at 222-S Laboratory. Analyses were performed in accordance with Tank 241-T-201 Push Mode Core Sampling and Analysis Plan (TSAP) (Hu, 1997), Letter of Instruction for Core Sample Analysis of Tanks 241-T-201, 241-T-202, 241-T-203, and 241-T-204 (LOI) (Bell, 1997), Additional Core Composite Sample from Drainable Liquid Samples for Tank 241-T-2 01 (ACC) (Hall, 1997), and Safety Screening Data Quality Objective (DQO) (Dukelow, et al., 1995). None of the subsamples submitted for total alpha activity (AT) or differential scanning calorimetry (DSC) analyses exceeded the notification limits stated in DQO. The statistical results of the 95% confidence interval on the mean calculations are provided by the Tank Waste Remediation Systems Technical Basis Group, and are not considered in this report.
Date: August 7, 1997
Creator: Nuzum, J.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Observation of resonant energy transfer between identical-frequency laser beams

Description: Enhanced transmission of a low intensity laser beam is observed when crossed with an identical-frequency beam in a plasma with a flow velocity near the ion sound speed. The time history of the enhancement and the dependence on the flow velocity strongly suggest that this is due to energy transfer between the beams via a resonant ion wave with zero frequency in the laboratory frame. The maximum energy transfer has been observed when the beams cross in a region with Mach 1 flow. The addition of frequency modulation on the crossing beams is seen to reduce the energy transfer by a factor of two. Implications for indirect-drive fusion schemes are discussed.
Date: December 9, 1998
Creator: Afeyan, B. B.; Cohen, B. I.; Estabrook, K. G.; Glenzer, S. H.; Joshi, C.; Kirkwood, R. K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Evaluation of concrete masonry unit walls for lateral natural phenomena hazards loads

Description: Older single-story facilities (Pre-1985 vintage) are commonly constructed of structural steel framing with concrete masonry unit (CMU) walls connected to columns and roof girders of the steel framing system. The CMU walls are designed for lateral wind and seismic loads (perpendicular to the wall) and transmit shear loads from the roof diaphragm to the foundation footings. The lateral loads normally govern their design. The structural framing system and the roof diaphragm system are straight forward when analyzing or upgrading the structure for NPH loads. Because of a buildings design vintage, probable use of empirical methodology, and poor design basis documentation (and record retention); it is difficult to qualify or upgrade CMU walls for lateral Natural Phenomena Hazards (NPH) loads in accordance with References 1, 2 and 3. This paper discusses three analytical approaches and/or techniques (empirical, working stress and yield line) to determine the collapse capacity of a laterally loaded CMU wall, and compares their results
Date: March 8, 1996
Creator: Faires, W.E. Jr.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Micro-machined heat pipes in silicon MCM substrates

Description: Multichip modules (MCMs) containing power components need a substrate with excellent heat spreading capability both to avoid hot spots and to move dissipated heat toward the system heat sinks. Polycrystalline diamond is an excellent MCM heat spreading substrate but remains several orders of magnitude too expensive and somewhat more difficult to process than conventional mother-board materials. Today`s power MCMs concentrate on moderately priced silicon wafers and aluminum nitride ceramic with their improved thermal conductivity and good thermal expansion match to power semiconductor components, in comparison to traditional alumina and printed wiring board materials. However, even silicon and AlN substrates are challenged by designers` thermal needs. We report on the fabrication of micro-heat pipes embedded in silicon MCM substrates (5{times}5 cm) by the use of micromachined capillary wick structures and hermetic micro-cavities. This passive microstructure results in more than a 5 times improvement in heat spreading capability of the silicon MCM substrate over a large range of power densities and operating temperatures as compared with silicon alone. Thus diamond-like cooling is possible at silicon prices.
Date: December 31, 1995
Creator: Benson, D.A.; Mitchell, R.T.; Tuck, M.R.; Adkins, D.R. & Palmer, D.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Quasi-continuous magnets

Description: The National High Magnetic Field Laboratory is completing a quasi-continuous magnet which will sustain a constant field of 60 T for 100 ms in a 32-mm 77 K bore. This magnet consists of 9 mechanically independent, nested, liquid nitrogen-cooled coils which are individually reinforced by high-strength stainless steel outer shells. The coils were wound from rectangular large cross-section, high-strength, high-conductivity copper conductor insulated wtih polyimide and fiberglass tapes. After winding, the coils were inserted into closely fitted, stainless steel reinforcing shells and impregnated with epoxy resin. Design, analysis, material, fabrication and operational issues for this class of magnets are reviewed. Fabrication and quality assurance testing of the 60 T coil set are covered in detail. Future growth of and possible links from this technology to other magnet systems are discussed. Needed improvements in design, analysis, materials, and fabrication are outlined.
Date: May 1, 1996
Creator: Sims, J.R.; Naumovich, G.J.; Hoang, T.A. & Dent, P.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

An Optimizing Algorithm for Automating Lifecycle Assembly Processes

Description: Designing products for ~ assembly and disassembly during its entire Iifecycle for purposes including service, field repair, upgrade, and disposal is a process that involves many disciplines. In additiou finding the best solution often involves considering the design as a whole and by considering its intended Iifecycle. DifFerent goals and cortstmints (compared to initial assembly) require us to re-visit the significant fi,mdamental assumptions and methods that underlie current assembly planning techniques. Previous work in this area has been limited to either academic studies of assembly planning or applied studies of lifecycle assembly processes, which give no attention to automatic planning. It is believed that merging these two areas will result in a much greater ability to design for, analyze, and optimize the disassembly and assembly processes.
Date: December 9, 1998
Creator: Brown, R.G. & Calton, T.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Development of lead-free solders for hybrid microcircuits

Description: Extensive work has been conducted by industry to develop lead-free solders for electronics applications. The driving force behind this effort is pressure to ban or tax the use of lead-bearing solders. There has been further interest to reduce the use of hazardous chemical cleaners. Lead-free soldering and low-residue, ``no clean`` assembly processing are being considered as solutions to these environmental issues. Most of the work has been directed toward commercial and military printed wiring board (PWB) technology, although similar problems confront the hybrid microcircuit (HMC) industry, where the development of lead-free HMC solders is generally lagging. Sandia National Laboratories is responsible for designing a variety of critical, high reliability hybrid components for radars. Sandia has consequently initiated a project, as part of its Environmentally Conscious Manufacturing program, to develop low-residue, lead-free soldering for HMCs. This paper discusses the progress of that work.
Date: January 1, 1996
Creator: Hosking, F.M.; Vianco, P.T.; Frear, D.R. & Robinson, D.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

A Planar Quantum Transistor Based on 2D-2D Tunneling in Double Quantum Well Heterostructures

Description: We report on our work on the double electron layer tunneling transistor (DELTT), based on the gate-control of two-dimensional -- two-dimensional (2D-2D) tunneling in a double quantum well heterostructure. While previous quantum transistors have typically required tiny laterally-defined features, by contrast the DELTT is entirely planar and can be reliably fabricated in large numbers. We use a novel epoxy-bond-and-stop-etch (EBASE) flip-chip process, whereby submicron gating on opposite sides of semiconductor epitaxial layers as thin as 0.24 microns can be achieved. Because both electron layers in the DELTT are 2D, the resonant tunneling features are unusually sharp, and can be easily modulated with one or more surface gates. We demonstrate DELTTs with peak-to-valley ratios in the source-drain I-V curve of order 20:1 below 1 K. Both the height and position of the resonant current peak can be controlled by gate voltage over a wide range. DELTTs with larger subband energy offsets ({approximately} 21 meV) exhibit characteristics that are nearly as good at 77 K, in good agreement with our theoretical calculations. Using these devices, we also demonstrate bistable memories operating at 77 K. Finally, we briefly discuss the prospects for room temperature operation, increases in gain, and high-speed.
Date: December 14, 1998
Creator: Baca, W.E.; Blount, M.A.; Hafich, M.J.; Lyo, S.K.; Moon, J.S.; Reno, J.L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Corrosion of SA1388-1 diodes

Description: After 5 y storage at Allied Signal, a subassembly with SA1388-1 diodes failed testing and the cause was an unacceptable current leak rate in one of the diodes. This was traced to a CuS deposit in a single production lot of diodes; however only about 0.3% failed the specification. A study was performed to determine the cause and potential long-term significance of this problem. Probable cause was determined to be the P-bearing braze material not being compatible with the Ag immersion plating solution (cyanide-based) and to the storage environment containing sulfur.
Date: June 1, 1996
Creator: Krska, C.; Stimetz, C.; Braithwaite, J.; Sorensen, R. & Hlava, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Insitu-Impregnated Capacitor for Pulse-Discharge Applications

Description: Capacitor designs for DOE and/or DoD applications are now driven by two major factors; first, the need to reduce component volumes (attain higher energy density) to permit inclusion of additional components and/ or sensors in systems and second, the continuing budget constraints. The reduced volume and cost must be achieved with no sacrifices in functionality, reliability and safety. Since this study was initiated, we have seen a general, continuous increase in resulting short-time breakdown (STB) values, with particular improvements noted on thermal cycled capacitors. Process and results support our prediction that a 50Y0-650A volume reduction can be achieved with no reduction in performance and reliability.
Date: January 15, 1999
Creator: Brooks, R.A.; Harris, J.O. & Pollard, J.R.
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Partner: UNT Libraries Government Documents Department

Generator acceptance test and inspection report

Description: This Acceptance Test Report(ATR) is the completed testing and inspection of the new portable generator. The testing and inspection is to verify that the generator provided by the vendor meets the requirements of specification WHC-S-0252, Revision 2. Attached is various other documentation to support the inspection and testing.
Date: July 24, 1997
Creator: Johns, B.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

ATP for the portable 500 CFM exhauster POR-006 skid D

Description: This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-006 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.
Date: July 29, 1997
Creator: Keller, C.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Development work on a new package design for the next generation microelectronics. Final report

Description: AlliedSignal and Micro-Mode Products joined under a DOE CRADA to develop a new package for next-generation electronics devices. Requirements included low cost of manufacture, ability to satisfy thermal expansion requirements, ability to satisfy thermal dissipation requirements, acceptable digital and microwave performance, and hermeticity. Four processes were tested; vacuum deposition of paralene, epoxy powder coating, transfer molding, and manual encapsulation. Transfer molding and manual potting improved the hermeticity but produced microcracking and reduced heat transfer ability following encapsulation. Additional study on manufacturing and encapsulating of the package is needed.
Date: November 1, 1996
Creator: Adams, B.E. & DeMarco, V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Development of a new class of satellites: a composite lightweight affordable spacecraft structure

Description: The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) has successfully designed and tested a Composite Lightweight Affordable Structure (CLASS). The use of advanced composites in space applications is well developed, but the application of an all-composite satellite structure has not been achieved until now. The development of this low-cost, lightweight, composite technology for use in small satellite structures, in this case, for the Fast On-Orbit Recording of Transient Events (FORT{acute E}) satellite mission will make a considerable contribution to the advanced spacecraft community. A common practice for constructing small spacecraft structures is to use an all-aluminum spacecraft bus. Compared to a composite structure, this reduces the payload capacity significantly; however, the cost of the aluminum structure has historically been lower than one of that uses lightweight components. LANL mission requirements dictate the need for a long term solution that substantially increased the ratio of payload to structural mass while maintaining a low-risk low-cost approach. LANL intends to use the concept developed for FORT{acute E} on future missions requiring similar enhanced payload capacities. 1 fig.
Date: June 1, 1996
Creator: Thompson, T.C. & Parietti, L.
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Partner: UNT Libraries Government Documents Department