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Ceramic microstructures and their elucidation by imaging, diffraction and spectroscopic methods

Description: The development and potential utilization of ceramic materials is dependent on a systematic effort involving processing, characterization and appropriate property measurements. The methods of characterization are numerous and it is important to employ the one that is appropriate to the problem both in terms of its information content and the achievable level of resolution. With the incorporation of fine probe forming capabilities in a transmission electron microscope and the development of rela… more
Date: February 1, 1992
Creator: Kirshnan, K.M.
Partner: UNT Libraries Government Documents Department
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The IGAC activity for the development of global emissions inventories: Description and initial results

Description: Modeling assessments of the atmospheric chemistry, air quality and climatic conditions of the past, present and future require as input inventories of emissions of the appropriate chemical species constructed on appropriate spatial and temporal scales. The task of the Global Emissions Inventories Activity (GEIA) of the International Global Atmospheric Chemistry Project (IGAC) is the production of global inventories suitable for a range of research applications. Current GEIA programs are general… more
Date: February 1, 1992
Creator: Benkovitz, C.M. (Brookhaven National Lab., Upton, NY (United States)) & Graedel, T.E. (AT and T Bell Labs., Murray Hill, NJ (United States))
Partner: UNT Libraries Government Documents Department
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Condensing economizers: Thermal performance and particulate removal efficiencies

Description: Condensing economizers can be used to increase the thermal efficiency of boilers and furnaces. This project has involved a study of these specifically for application to coal-water mixture fuels although the results can be extended to other fuels. experimental studies to evaluate thermal performance and removal of particulates across indirect contract economizers have been performed. The test arrangement incorporates oil firing with the injection of flyash into the flue gas to simulate coal com… more
Date: February 1, 1992
Creator: Butcher, T.A.; Litzke, Wai Lin (Brookhaven National Lab., Upton, NY (United States)) & Park, N. (Stony Brook Scientific, Ltd., Morristown, PA (United States))
Partner: UNT Libraries Government Documents Department
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Application of automated deduction to the search for single axioms for exponent groups

Description: We present new results in axiomatic group theory obtained by using automated deduction programs. The results include single axioms, some with the identity and others without, for groups of exponents 3, 4, 5 and 7, and a general form for single axioms for groups of odd exponent. The results were obtained by using the programs in three separate ways: as a symbolic calculator, to search for proofs,and to search for couterexamples. We also touch on relations between logic programming and automated … more
Date: February 11, 1992
Creator: McCune, W. & Wos, L.
Partner: UNT Libraries Government Documents Department
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Operation and radiation resistance of a FOXFET biasing structure for silicon strip detectors

Description: AC-coupled strip detectors biased with a FOXFET transistor structure have been studied. Measurement results for the basic operational characteristics of the FOXFET are presented together with a brief description of the physics underlying its operation. Radiation effects were studied using photons from a {sup 137}Cs source. Changes in the FOXFET characteristics as a function of radiation dose up to 1 MRad are reported. Results about the effect of radiation on the noise from a FOXFET biased detec… more
Date: February 1, 1992
Creator: Laakso, M. (Fermi National Accelerator Lab., Batavia, IL (United States) Helsinki Univ. (Finland). Dept. of High Energy Physics); Singh, P.; Engels, E. Jr. & Shepard, P. (Pittsburgh Univ., PA (United States). Dept. of Physics and Astronomy)
Partner: UNT Libraries Government Documents Department
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The RQM triangle: A paradigm for relativistic quantum mechanics

Description: A simple way to relate Lorentz transformations to a finite and discrete model of counter firings is presented. We first abstract from counter firings with finite resolution to rational fraction velocities and a finite step-length. Discrete Lorentz transformations and quantized rotations follow. These are encoded by three integers and a triangle with integer sides: the RQM Triangle. The double slit experiment allows us to observe quantized space steps and measure invariant step lengths for any p… more
Date: February 1, 1992
Creator: Noyes, H. Pierre
Partner: UNT Libraries Government Documents Department
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Z yields jets+. gamma. as a signal for R-parity violation

Description: Supersymmetric models with explicit R-parity violation can induce new rare decay modes of the Z boson into single supersymmetric particles. Here, the rate and signature for one such decay, Z {yields} {tilde {upsilon}} {gamma}, is examined, where it is found that the rate is at least an order of magnitude smaller than that for the process Z{yields} H{gamma}, even with larger values of the R-parity violating couplings.
Date: February 1, 1992
Creator: Hewett, J.L.
Partner: UNT Libraries Government Documents Department
open access

On the measuremnt of. pi

Description: Inspired by Stillman Drake's definition of Galilean Units as those for which (L/T{sup 2} = ({pi}{sup 2}/8)g) where g is any finite, constant acceleration measured in units of L and T, we construct a kinematical dimensional analysis based only on two universal, dimensionless constants. For the linear relation between L and T we use Einsteinian Units L/ = (1)c. For orbiting masses negligible compared to some mass unit M, we use Keplerian Units based on his second law (L{sup 2}/T = (1/2{pi})h/M). … more
Date: February 1, 1992
Creator: Noyes, H. Pierre
Partner: UNT Libraries Government Documents Department
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Inverse phase transitions: Does baryogenesis lead to dark matter

Description: The phase structure of a field theory can have two qualitatively different forms- the less familiar of which involves high temperature symmetry breaking and low temperature symmetry restoration and is dubbed an inverse phase transition. After a general discussion of such inverse phase transitions we present an application of this phenomenon in which the symmetry under consideration is baryon number. The model has the virtues of generating the observed quark-antiquark asymmetry (with no explicit… more
Date: February 1, 1992
Creator: Dodelson, S. (Fermi National Accelerator Lab., Batavia, IL (United States)); Greene, B.R. (Cornell Univ., Ithaca, NY (United States). Newman Lab. of Nuclear Studies) & Widrow, L.M. (Toronto Univ., ON (Canada). Canadian Inst. for Theoretical Astrophysics)
Partner: UNT Libraries Government Documents Department
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Information systems for engineering sustainable development

Description: The ability of a country to follow sustainable development paths is determined to a large extent by the capacity or capabilities of its people and its institutions. Specifically, capacity-building in the UNCED terminology encompasses the country's human, scientific, technological, organizational, institutional, and resource capabilities. A fundamental goal of capacity-building is to enhance the ability to pose, evaluate and address crucial questions related to policy choices and methods of impl… more
Date: February 27, 1992
Creator: Leonard, R.S.
Partner: UNT Libraries Government Documents Department
open access

The 17 keV neutrino and neutrino tagging

Description: P-788 at FNAL proposed to search for neutrino oscillations in a tagged neutrino line. A K{sub L} beam and the decay modes K{sub L} {yields} {pi}{mu}{nu}{sub {mu}} and K {sub L} {yields} {pi}e{nu}{sub e} provides the neutrino flux. An upstream tagging spectrometer then identifies the hadron and lepton and reconstructs the K{sub L} decay; the lepton identification will specifies the neutrino as {nu}{sub e} or {nu}{sub {mu}} and distinguishes {nu} from {bar {nu}} at the decay vertex. A neutrino de… more
Date: February 1, 1992
Creator: Bernstein, R.H.
Partner: UNT Libraries Government Documents Department
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Cluster assembly of hierarchical nanostructures

Description: In the past few years, atom clusters with diameters in the range of 2--20 nm of a variety of materials, including both metals and ceramics, have been synthesized by evaporation and condensation in high-purity gases and subsequently consolidated in situ under ultrahigh vacuum conditions to create nanophase materials. These new utlrafine-grained materials have properties that are often significantly different and considerably improved relative to those of their coarser-grained counterparts owing … more
Date: February 1, 1992
Creator: Siegel, R. W.
Partner: UNT Libraries Government Documents Department
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Investigation of the oxygen-vacancy (A-center) defect complex profile in neutron irradiated high resistivity silicon junction particle detectors

Description: Distributions of the A-center (oxygen-vacancy) in neutron silicon detectors have been studied using Deep Level Transient Spectroscopy. A-centers have been found to be nearly uniformly distributed in the silicon water depth for medium resistivity (0.1 {minus} 0.2 k{Omega}-cm) silicon detectors. A positive filling pulse was needed to detect the A-centers in high resistivity (>4 k{Omega}-cm) silicon detectors, and this effect was found to be dependent on the oxidation temperature. A discussion of … more
Date: February 1, 1992
Creator: Li, Zheng; Kraner, H.W. (Brookhaven National Lab., Upton, NY (United States)); Verbitskaya, E.; Eremin, V.; Ivanov, A. (AN SSSR, St. Petersburg (Russian Federation). Physico-Technical Inst.); Rattaggi, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of high beam rates on TPC's

Description: The TPC's (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchroton) were exposed to silicon ion fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to measure the distortion of the electric field caused by positive ions in the drift region. Results of these tests are presented and the consequences for the TPC based experiment at RHIC (Relativistic Heavy Ion Collider) are discussed.
Date: February 6, 1992
Creator: Etkin, A.; Eiseman, S. E.; Foley, K. J.; Hackenburg, R. W.; Longacre, R. S.; Love, W. A. et al.
Partner: UNT Libraries Government Documents Department
open access

An approximation method for dynamic response of strain-hardening structures

Description: An approximation method is being developed to predict the dynamic plastic response of rigid, strain-hardening structures. This method is analogous to the instantaneous mode techniques used to treat rigid, perfectly plastic structures in that deflection shape involving a number of arbitrary functions of time selected, based on static deformation profiles. Two stress fields are associated with the deflection shape: one satisfies the equations of motion with appropriate boundary and continuity con… more
Date: February 1, 1992
Creator: Youngdahl, C.K.
Partner: UNT Libraries Government Documents Department
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Mechanism of strain release in carbon nanotubes

Description: Article on the mechanism of strain release in carbon nanotubes.
Date: February 15, 1998
Creator: Buongiorno Nardelli, Marco; Yakobson, Boris I. & Bernholc, Jerry
Partner: UNT College of Arts and Sciences
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Studies of helium based drift chamber gases for high-luminosity low energy machines

Description: Future high luminosity low energy machines will need low mass tracking chambers to order to minimize multiple scattering of the relatively low momentum tracks produced at these facilities. A drift chamber using a helium based gas rather than a conventional argon based gas would greatly reduce the amount of multiple scattering. This paper summarizes measurements of the drift velocity and position resolution for gas mixtures of helium with CO{sub 2} and isobutane and helium with DME. Good spatial… more
Date: February 1, 1992
Creator: Boyarski, A.; Briggs, D. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Burchat, P.R. (California Univ., Santa Cruz, CA (United States). Inst. for Particle Physics)
Partner: UNT Libraries Government Documents Department
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Observation of electron polarization above 80% in photoemission from strained III-V compounds

Description: Spin-polarized electron photoemission has been investigated for strained III--V compounds; (1) strained In{sub x}Ga{sub 1-x}As epitaxially grown on a GaAs substrate, and (2) strained GaAs grown on a GaAs{sub 1-x}P{sub x} buffer layer. The lattice mismatched heterostructure results in a highly strained epitaxial layer, and electron spin polarization as high as 90% has been observed.
Date: February 1, 1992
Creator: Garwin, E. L.; Maruyama, T. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Prepost, R. & Zapalac, G. H. (Wisconsin Univ., Madison, WI (United States). Dept. of Physics)
Partner: UNT Libraries Government Documents Department
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A possible design for the NLC e sup + source

Description: The Next Linear Collider (NLC) currently under investigation at SLAC requires a positron source with a flux of about 8.6 {times} 10{sup 13} particles per second, 14.4 times more than the SLC source. Based on the SLC experience, a source for NLC is proposed that can be realized with present accelerator technology. It consists of a 7 GeV S-band electron linac, a solid moving target, a 1.8 GeV L-band positron accelerator and a pre-damping ring with a large acceptance. The pre-damping ring performs… more
Date: February 1, 1992
Creator: Braun, H. (Paul Scherrer Inst. (PSI), Villigen (Switzerland)); Clendenin, J.; Eucklund, S.; Kulikov, A. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Pitthan, R. (European Organization for Nuclear Research, Geneva (Switzerland))
Partner: UNT Libraries Government Documents Department
open access

Ideas for a long-baseline neutrino detector

Description: The Atmospheric Neutrino Deficit defines a region in {Delta}m{sup 2}-sin{sup 2}2{theta} space which ought to be conclusively tested in a long-baseline experiment. This talk sets out a region to cover (which may change as more data is analyzed) and translates that region into an L/E. I present exclusion curves for different experiments based on their distance and their precision; I conclude that an experiment which can detect oscillations down to 1% located at 1200 km will cleanly test the allow… more
Date: February 1, 1992
Creator: Bernstein, R.
Partner: UNT Libraries Government Documents Department
open access

Applications of circularly polarized photons at the ALS with a bend magnet source

Description: The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studi… more
Date: February 1, 1992
Partner: UNT Libraries Government Documents Department
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Modeling of a dissolution system for transuranic compounds

Description: A system is currently being developed at Lawrence Livermore Laboratory to treat transuranic wastes by means of a mediated electrochemical oxidation process. The process involves generating Ag({sup ++}) from a solution of silver nitrate and nitric acid in an electrochemical cell. Ag({sup ++}) is highly reactive and is capable of attacking many organic and inorganic substances. In particular, if a mixture of particles containing transuranic and other scrap metal oxides is allowed to react with Ag… more
Date: February 1, 1991
Creator: Chiba, Z. & Dease, C.
Partner: UNT Libraries Government Documents Department
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SLAC B Factory computing

Description: As part of the research and development program in preparation for a possible B Factory at SLAC, a group has been studying various aspects of HEP computing. In particular, the group is investigating the use of UNIX for all computing, from data acquisition, through analysis, and word processing. A summary of some of the results of this study will be given, along with some personal opinions on these topics.
Date: February 1, 1992
Creator: Kunz, P. F.
Partner: UNT Libraries Government Documents Department
open access

The audit checklist: Your key to audit success

Description: As the old saying goes, If you have no objective, any road will take your there.'' So it is with the audit checklist. The checklist is the primary tool for providing order to Quality Assurance audit activities. With a well-planned and well-defined checklist, success is achievable. Without a checklist, the auditor has a disjointed, disorganized activity and no place to document his or her failed efforts. A number of formal quality programs which include audits as one of their program elements re… more
Date: February 1, 1992
Creator: Maday, J.H. Jr.
Partner: UNT Libraries Government Documents Department
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