Search Results

Advanced search parameters have been applied.

MEMS inertial sensors with integral rotation means.

Description: The state-of-the-art of inertial micro-sensors (gyroscopes and accelerometers) has advanced to the point where they are displacing the more traditional sensors in many size, power, and/or cost-sensitive applications. A factor limiting the range of application of inertial micro-sensors has been their relatively poor bias stability. The incorporation of an integral sensitive axis rotation capability would enable bias mitigation through proven techniques such as indexing, and foster the use of inertial micro-sensors in more accuracy-sensitive applications. Fabricating the integral rotation mechanism in MEMS technology would minimize the penalties associated with incorporation of this capability, and preserve the inherent advantages of inertial micro-sensors.
Date: September 1, 2003
Creator: Kohler, Stewart M.
Partner: UNT Libraries Government Documents Department

TRANSMISSION-LINE MISSILE ANTENNAS

Description: Protruding rocket antennas of low silhouette are examined using transmission-line concepts. The theory was developed specifically for nondissipative terminations and line sections; however, the formulas are readily generalized to include ohmic losses in the lines and terminations. Adaptive computations may be made for conductors other than circular and the theory may be used to analyze antennas of other missiles. (J.R.D.)
Date: November 20, 1958
Creator: King, R.W.P.; Harrison, C.W. Jr. & Denton, D.H. Jr.
Partner: UNT Libraries Government Documents Department

GEORGE PROGRAMMING MANUAL

Description: GEORGE is an automatic high-speed electronic digital computer designed and constructed by ANL. Operating features of GEORGE are described, and a practical set of instructions is given that will enable a prospective user to construct codes, operate the machine and its auxiliary equipment, use the basic routines available in the routine library, and decide whether a particular problem is suitable on the basis of capacity, speeds and auxiliary equipment. (W.D.M.)
Date: May 1, 1959
Creator: Kassel, L.
Partner: UNT Libraries Government Documents Department

Automotive Vehicle Sensors

Description: This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.
Date: September 1995
Creator: Sheen, S. H.; Raptis, A. C. & Moscynski, M. J.
Partner: UNT Libraries Government Documents Department

Microfabrication with femtosecond laser processing : (A) laser ablation of ferrous alloys, (B) direct-write embedded optical waveguides and integrated optics in bulk glasses.

Description: At Sandia National Laboratories, miniaturization dominates future hardware designs, and technologies that address the manufacture of micro-scale to nano-scale features are in demand. Currently, Sandia is developing technologies such as photolithography/etching (e.g. silicon MEMS), LIGA, micro-electro-discharge machining (micro-EDM), and focused ion beam (FIB) machining to fulfill some of the component design requirements. Some processes are more encompassing than others, but each process has its niche, where all performance characteristics cannot be met by one technology. For example, micro-EDM creates highly accurate micro-scale features but the choice of materials is limited to conductive materials. With silicon-based MEMS technology, highly accurate nano-scale integrated devices are fabricated but the mechanical performance may not meet the requirements. Femtosecond laser processing has the potential to fulfill a broad range of design demands, both in terms of feature resolution and material choices, thereby improving fabrication of micro-components. One of the unique features of femtosecond lasers is the ability to ablate nearly all materials with little heat transfer, and therefore melting or damage, to the surrounding material, resulting in highly accurate micro-scale features. Another unique aspect to femtosecond radiation is the ability to create localized structural changes thought nonlinear absorption processes. By scanning the focal point within transparent material, we can create three-dimensional waveguides for biological sensors and optical components. In this report, we utilized the special characteristics of femtosecond laser processing for microfabrication. Special emphasis was placed on the laser-material interactions to gain a science-based understanding of the process and to determine the process parameter space for laser processing of metals and glasses. Two areas were investigated, including laser ablation of ferrous alloys and direct-write optical waveguides and integrated optics in bulk glass. The effects of laser and environmental parameters on such aspects as removal rate, feature size, feature definition, and ablation angle during the ablation …
Date: November 1, 2004
Creator: Guo, Junpeng; McDaniel, Karen Lynn; Palmer, Jeremy Andrew; Yang, Pin; Griffith, Michelle Lynn; Vawter, Gregory Allen et al.
Partner: UNT Libraries Government Documents Department

Detection and Measurement of Nuclear Radiation

Description: The technique of radiation characterization is reviewed, with particular emphasis on new methods and their practi-cal aspects. Each type of detector is discussed in terms of its principle of operation and its applicability to various problems in counting and spectrometry. Auxiliary electronic instrumentation and the function of each instrument are described in general terms. Other topics discussed include low-level counting, absolute counting, and the mounting of radioactive sources. (137 references.) (C.H.)
Date: December 1, 1961
Creator: O'Kelley, G. D.
Partner: UNT Libraries Government Documents Department

A Brief Discussion of Radiation Hardening of CMOS Microelectronics

Description: Commercial microchips work well in their intended environments. However, generic microchips will not fimction correctly if exposed to sufficient amounts of ionizing radiation, the kind that satellites encounter in outer space. Modern CMOS circuits must overcome three specific concerns from ionizing radiation: total-dose, single-event, and dose-rate effects. Minority-carrier devices such as bipolar transistors, optical receivers, and solar cells must also deal with recombination-generation centers caused by displacement damage, which are not major concerns for majority-carrier CMOS devices. There are ways to make the chips themselves more resistant to radiation. This extra protection, called radiation hardening, has been called both a science and an art. Radiation hardening requires both changing the designs of the chips and altering the ways that the chips are manufactured.
Date: December 18, 1998
Creator: Myers, D.R.
Partner: UNT Libraries Government Documents Department

Direct-Write Precision Resistors for Ceramic Packages

Description: A direct-write approach to f abricate high precision resistors is reported. Special attention is paid to the effect of print thickrw;s on the resistance value of buried resistors after a low temperature co-firing process. The results show that the direct-write approach provides a superior line definition and thickness control over a traditional screen printing process. Microstructural analysis indicates that there is an interdiffused layer developed between the resistor material and the low temperature co-fired ceramic substrate. These observations are consistent with electrical IIH.SUKHIlentS which show that resistance increases as the effective cross-sectional area is reduced. Th: resistance data show that the standard deviations for resistors printed on a 6" x 6" area are 59Z0 and 15$Z0 for the direct-write and the screen-printed patterns, respectively.
Date: November 30, 1998
Creator: Dai, S.; Dimos, D.; Huang, R.F.; Rodriguez, M.A.; Wilcox, D. & Yang, P.
Partner: UNT Libraries Government Documents Department

Planning, Scheduling, and Expediting Engineering Projects With the Aid of Electronic Computers

Description: >Submitted to Illinois Inst. of Tech., Chicago. Two methods for planning, scheduling, and monitoring engineering and scientific research and development projects are discussed. They are the Critical Path Method and PERT. The specific development and implementation of network analysis techniques being used in the construction of the Zero Gradient Synchrotron are described. The historical development of the Critical Path Method and PERT is outlined. Network diagrams, numbering network diagrams, activity duration times, mathematical evaluation of the network, government and industrial use of PERT and CPM, and applications of network analysis techniques are discussed. (M.C.G.)
Date: May 1, 1962
Creator: Pollock, J. C.
Partner: UNT Libraries Government Documents Department

Predicting Electronic Failure from Smoke

Description: Smoke can cause electronic equipment to fail through increased leakage currents and shorts. Sandia National Laboratories is studying the increased leakage currents caused by smoke with varying characteristics. The objective is to develop models to predict the failure of electronic equipment exposed to smoke. This requires the collection of data on the conductivity of smoke and knowledge of critical electrical systems that control high-consequence operations. We have found that conductivity is a function of the type of fuel, how it is burned, and smoke density. Video recordings of highly biased dc circuits exposed in a test chamber show that during a fire, smoke is attracted to high voltages and can build fragile carbon bridges that conduct leakage currents. The movement of air breaks the bridges, so the conductivity decreases after the fire is extinguished and the test chamber is vented. During the fire, however, electronic equipment may not operate correctly, leading to problems for critical operations dependent on electronic control. The potential for electronic failure is highly dependent on the type of electrical circuit, and Sandia National Laboratories plans to include electrical circuit modeling in the failure models.
Date: January 15, 1999
Creator: Tanaka, T.J.
Partner: UNT Libraries Government Documents Department

Electronics for Calorimeters at LHC

Description: Some principal design features of front-end electronics for calorimeters in experiments at the LHC will be highlighted. Some concerns arising in the transition from the research and development and design phase to the construction will be discussed. Future challenges will be indicated.
Date: September 11, 2001
Creator: Radeka, V.
Partner: UNT Libraries Government Documents Department

Electronics for Calorimeters at LHC

Description: Some principal design features of front-end electronics for calorimeters in experiments at the LHC will be highlighted. Some concerns arising in the transition from the research and development and design phase to the construction will be discussed. Future challenges will be indicated.
Date: September 11, 2001
Creator: Radeka, V.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen