Physical Sciences and Mathematics Commons^™

Progress In The Study Of Cdznte Strip Detectors, O Tousignant, L A. Hamel, J F. Courville, P Paki, John R. Macri, K Larson, M Mayer, Mark L. Mcconnell, James M. Ryan

Space Science Center

We report new performance measurements and computer simulations of a sub-millimeter pitch CdZnTe strip detector under study as a prototype imaging spectrometer for astronomical x-ray and gamma-ray observations. The prototype is 1.5 mm thick with 375 micron strip pitch in both the x and y dimensions. Previously reported work included demonstrations of half-pitch spatial resolution (approximately 190 microns) and good energy resolution and spectral uniformity. Strip detector efficiency measurements have also been presented. A model that includes the photon interaction, carrier transport and the electronics was developed that qualitatively reproduced the measurements. The new studies include measurements of the CdZnTe …

Synthetic Strategies For The Construction Of Enantiomeric Azanoradamantanes, Daniel Becker, Roger Nosal, Daniel L. Zabrowski, Daniel Flynn

Chemistry: Faculty Publications and Other Works

The amino azanoradamantane hexahydro-2,5b-methano-IH-3aS,3aa,6aa-cyclopenta-[clpyrrole-4a-amine 1and the corresponding enantiomer ent-1 have been prepared along with benzamide derivatives SC-52491and SC-52490, respectively, which are of pharmaceutical interest. The key meso-azabicyclo[3.3.0] intermediate 3 was prepared via three separate routes: a [3+2] cycloaddition route, a radical cyclization/ionic cyclization route, and a reductive Pauson-Khand route.

High Resolution Imaging Of Thin-Film Recording Heads By Superparamagnetic Magnetic Force Microscopy Tips, Sy_Hwang Liou, S.S. Malhotra, John Moreland, P.F. Hopkins

Sy-Hwang Liou Publications

We have used superparamagnetic magnetic force microscopy (MFM) tips to obtain high spatial resolution MFM images of recording heads. Profiles of the magnetic field gradient above a thin-film recording head under 3 mA bias current to the head and various tip-head distance conditions are presented. At a low tip-head distance, the gap width, gap location, and gap-field structure can be well resolved in these MFM images. Superparamagnetic tips show promise for the magnetic imaging of recording heads with gap widths below 200 nm.

The Duals Of Warfield Groups, Peter Loth

Mathematics Faculty Publications

A Warfield group is a direct summand of a simply presented abelian group. In this paper, we describe the Pontrjagin dual groups of Warfield groups, both for the p-local and the general case. A variety of characterizations of these dual groups is obtained. In addition, numerical invariants are given that distinguish between two such groups which are not topologically isomorphic.

Normal Lattices And Coseparation Of Lattices, Barry B. Mittag

Mathematics Faculty Publications

No abstract provided.

Nanolithography With Metastable Neon Atoms: Enhanced Rate Of Contamination Resist Formation For Nanostructure Fabrication, Steven J. Rehse, A.D. Glueck, S.A. Lee, A.B. Goulakov

Physics Publications

We report a sevenfold improvement in the rate of contamination resist formation over previous experiments by using metastable neon atoms for nanolithography. Chemically assisted ion beam etching was used to transfer the resist pattern into the substrate. We demonstrate the fabrication of 50-nm-wide features in GaAs with well-defined edges and an aspect ratio >2:1. These are the best resolution and highest aspect ratio features that have been achieved with metastable atom lithography. The resist formation rate by the metastable neon atoms and the etch selectivity of the contamination resist with GaAs were measured.

Computational Methods For Three-Electron Atomic Systems In Hylleraas Coordinates, Z. C. Yan, Gordon W. F. Drake

Physics Publications

General methods for evaluating three-electron integrals in Hylleraas coordinates are given. Formulae are obtained for the matrix elements of various operators arising in Hylleraas-type variational calculations for states of arbitrary angular momentum. For the calculations of Breit interaction, a number of reduction relations are developed for the elimination of singularities in some singular integrals. A numerically stable scheme is presented for the case when one of the powers of r ij is -2.

The Virginia Wetlands Report Vol. 12, No. 1, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Double-Crested Cormorant. Julie G. Bradshaw
• What is the Coastal Primary Sand Dune Protection Act? William Roberts
• Playing” Wetland Board is Excellent Learning Tool for Virginia Beach Students. Karla Schillinger
• Atlantic Silverside. Lyle Varnell
• GIS as an Educational Tool. Marcia Berman
• Medicinal Uses of Wetlands. Pam Mason

Molecular Dynamics Of Crosslinked And Normal Hemoglobins, Liang Zhao

Master's Theses

No abstract provided.

Development Of Crosslinking Reagents, And Intra- And Intermolecular Multi-Linking Hemoglobin Molecules As Potential Blood Substitutes, Yaguo Zheng

Dissertations

No abstract provided.

Multinuclear Magnetic Resonance Studies Of Anion Binding To Copper, Zinc-Superoxide Dismutase, And Of Lithium Transport And Binding In Cultured Neuroblastoma Cells, Cherian Zachariah

Dissertations

No abstract provided.

Ionic Interaction Studies Of Bovine Copper, Zinc-Superoxide Dismutase, Hanan A. Hasan

Dissertations

No abstract provided.

The Computational Study Of "Model" Pollutants In Clay Montmorillonite, Sung-Ho Park

Dissertations

No abstract provided.

Ph And Osmolality Effects On Lipid-Enhanced Sickle And Normahemoglobin Oxidation, Sharron Kay Jenkins

Dissertations

No abstract provided.

Raman-Scattering Study Of The Order-Disorder Phase Transition In Kscn, R. Li, John R. Hardy

John R. Hardy Papers

Raman measurements were performed from room temperature to above the phase transition at 413 K on KSCN crystals. The internal mode spectra reveal a sideband above the internal CN stretching vibration which shows softening in frequency approaching the phase transition, while the CN mode shifts toward higher frequencies. Given that the sideband is a two-phonon process, involving an off-zone-center CN stretching mode and a lattice phonon, the substantial softening in its frequency shift indicates the possibility of an off-zone-center lattice instability related to the order-disorder phase transition. An anomalous temperature dependence was also found for the intensity of both the …

1997 Platte River Basin Ecosystem Symposium Proceedings

Water Current Newsletter

No abstract provided.

Implementing Uneven-Aged Redwood Management At Cal Poly's School Forest, An Update, Douglas D. Piirto, Richard P. Thompson, Kevin L. Piper

Natural Resources Management and Environmental Sciences

California Polytechnic State University's School Ranch and Forest, called Swanton Pacific Ranch, is located just north of Santa Cruz, California and encompasses approximately 3,800 acres of crop, range, and forested areas. Coast redwood (Sequoia sempervirens [D. Don] Endl.), Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) and tanoak (Lithocarpus densiflorus [Hook. & Arn.] Rehd.) occur on approciximately 1,900 acres of the Swanton Pacific Ranch and at Valencia. Because of its high stumpage value, coast redwood is the preferred management species. In addition to economic reality, California Forest Practice laws severely limit the extent of stand manipulation that …

Agent-Based Expert Assistance For Visual Problem Solving, Erika Rogers, Robin R. Murphy, Barb Ericson

Computer Science and Software Engineering

This paper presents a domain-independent architecture for facilitating visual problem solving between robots or softbots and humans. The architecture defines virtual and human agents in terms of their inherent cognitive and perceptual abilities, and their weak and strong knowledge sources. It introduces a third agent, an expert assistant called teleVIA, to mediate the flow of information, facilitate cooperation, filter and cache data, and generate the appropriate visual displays. The agent architecture addresses the technical issues of using an expert assistant to coordinate perception, thought, and action, manage sensing and perception, facilitate diagnosis, and to support the collaboration between people and …

Molecular Engineering Of Side-Chain Liquid Crystalline Polymers By Living Polymerizations, Coleen Pugh, Alan L. Kiste

Chemistry and Biochemistry

“Living” anionic, cationic, metalloporphyrin and ring-opening metathesis polymerizations have been used to prepare well-defined side-chain liquid crystalline homopolymers, block and graft copolymers and statistical copolymers. This paper analyzes their successes and failures by reviewing the mechanistic aspects and experimental conditions of each type of polymerization, and identifies other classes of mesogenic monomers that could be polymerized in a controlled manner in the future. The emerging structure/property relationships are then identified using well-defined SCLCPs in which only one structural feature is varied while all others remain constant.

The thermal transitions of liquid crystalline polymethacrylates, polynorbomenes and poly(viny1 ether)s reach their limiting …

Galactic Black Hole Binaries: High-Energy Radiation, J E. Grove, J E. Grindlay, B A. Harmon, X M. Hua, D Kazanas, Mark L. Mcconnell

Space Science Center

Observations of galactic black hole candidates made by the instruments aboard the Compton GRO in the hard X-ray and γ-ray bands have significantly enhanced our knowledge of the phenomenology of the emission from these objects. Understanding these observations presents a formidable challenge to theoretical models of the accretion flow onto the compact object and of the physical mechanisms that generate high-energy radiation. Here we summarize the current state of observations and theoretical interpretation of the emission from black holecandidates above 20 keV. The all-sky monitoring capability of BATSE allows, for the first time, nearly continuous studies of the high-energy emission …

5 Years Of Crab Pulsar Observations With Comptel, R Much, K Bennett, C Winkler, R Diehl, G G. Lichti, V Schonfelder, H Steinle, A W. Strong, M Varendorff, W Hermsen, L Kuiper, R Van Der Meulen, A Connors, Mark L. Mcconnell, James M. Ryan, R Buccheri

Space Science Center

Using the COMPTEL data of the first 5 years of the CGRO mission we have derived the average pulsed spectrum of the Crab Pulsar, as well as phase-resolved spectra of the pulsed emission of the Crab Pulsar. The spectra in the COMPTEL energy range (0.75 to 30 MeV) are compared to those in the neighboring energy bands. The pulsed flux has been examined for its stability. Pulsed lightcurves have been derived for different energy intervals. Preliminary results of this analysis are presented.

Evidence For Γ-Ray Flares In 3c 279 And Pks 1622-297 At ∼10 Mev, W Collmar, V Schonfelder, H Bloemen, J J. Blom, W Hermsen, Mark L. Mcconnell, J G. Stacy, K Bennett, O R. Williams

Space Science Center

The EGRET experiment aboard the Compton Gamma-Ray Observatory (CGRO) has observed at energies above 100 MeV strong gamma-ray flares with short-term time variability from thegamma-ray blazars 3C 279 [1] and PKS 1622-297 [2]. During these flaring periods both blazarshave been detected by the COMPTEL experiment aboard CGRO at photon energies of ∼10 MeV, revealing simultaneous γ-ray activity down to these energies. For both cases the derived fluxes exceed those measured in previous observations, and 3C 279 shows an indication for time variability within the observational period. Both sources show evidence for ‘hard’ MeV spectra. In general the behaviour of both …

Improved Comptel 10–30 Mev Event Selections For Point Sources From Inflight Data, W Collmar, U Wessolowski, V Schonfelder, G Weidenspointer, S C. Kappadath, Mark L. Mcconnell, K Bennett

Space Science Center

After several years in orbit the COMPTEL experiment aboard the COMPTON Gamma-RayObservatory has collected a substantial amount of data from the MeV sky. We have used the inflight event data collected from the Crab, which is the brightest point source at MeV energies, to optimize our event selections for point sources. For the COMPTEL 10–30 MeV range we have derived a set of improved parameter selections, which leads to a reduction of background events and—at the same time—increases the number of source events, resulting in an obvious improvement in the signal-to-background ratio for point sources. Due to a revised cut …

The Prompt Cosmic-Ray-Induced Background In The Orbiting Compton Telescope Comptel, James M. Ryan, S C. Kappadath, Mark L. Mcconnell, D Morris, V Schonfelder, M Varendorff, G Weidenspointer, W Hermsen, K Bennett

Space Science Center

The authors report the spectrum of background events that the COMPTEL instrument on ComptonGamma Ray Observatory experiences due to the instantaneous effects of cosmic rays. Otherbackgrounds are present in the data of this Compton telescope, but the components that closely follow the instantaneous flux of cosmic rays are the most identifiable. The background varies approximately linearly with the cosmic-ray intensity and exhibits a broad feature from about 1 to 10 MeV suggestive of the nuclear nature of the events. Above 10 MeV there is a marked change in the nature of thebackground that is not understood. It appears that the …

How Some Risk Frameworks Disenfranchise The Public, Kristin Shrader-Frechette

RISK: Health, Safety & Environment (1990-2002)

The author responds to recent characterizations of her work.

The Decision To Reactivate A First-Generation Soviet Nuclear Power Plant: Conceptual And Decision-Analytic Frameworks, John M. Gleason

RISK: Health, Safety & Environment (1990-2002)

Explores a variety of factors that led to reopening the Armenian Metsamor facility notwithstanding general agreement that this is unwarranted technologically.

Book Review Of Bruce M. Owen Et Al., The Economics Of A Disaster - The Exxon Valdez Oil Spill, William C. Shaw Ii

RISK: Health, Safety & Environment (1990-2002)

Review of Bruce M. Owen, David A. Argue, Harold W. Furchtgott-Roth, Gloria J. Hurdle & Gale Mosteller, The Economics of a Disaster - The Exxon Valdez Oil Spill (Quorum Books 1995). Acknowledgments, appendices, author index, figures, selected bibliography, subject index, tables. LC 95- 3782; ISBN 0-89930-987-9. [200 pp. Cloth $55.00. 88 Post Road West, Westport CT 06881.]

Operation And Control In A Competitive Market: Distributed Generation In A Restructured Industry, Judith Cardell, Richard Tabors

Engineering: Faculty Publications

The prospect of independent ownership for distributed technologies is being encouraged by the current deregulation of the industry, and it is possible that the new generators will be independently operated as well as independently owned. The siting of numerous small-scale generators in distribution feeders is likely to have an impact on the operations and control of the power system, a system designed to operate with large, central generating facilities. In response to the new and potentially conflicting economic and technical demands of a growing number of independent players, the power system may require new means for coordinating system operations. Price …

Using Atm Networks For Processing Global Earth Data, Barbara L. Kess, Phillip R. Romig Iii, Stephen E. Reichenbach, Ashok K. Samal

CSE Conference and Workshop Papers

amount of computational power to researchers at an affordable cost, making it feasible to use workstations rather than expensive supercomputers to perform scientific analysis of large data sets, such as the Global Land 1-Km AVHRR data. In addition to this, inexpensive high speed ATM networks have the potential to improve the overall computational efficiency of workstations by using several workstations in a distributed environment. This research studies the practicality of using distributed workstations interconnected with a 155 Mb ATM network for analysis and compression of the Global Land 1-Km AVHRR data versus sequential computing on one of the workstations. Performance …

Synthesis For Testability By Two-Clock Control, Shashank K. Mehta, Sharad C. Seth, Kent L. Einspahr

CSE Conference and Workshop Papers

In previous studies clock control has been inserted after design to improve the testability of a sequential circuit. In this paper we propose a two-clock control scheme that is included as a part of the logic synthesis of a finite state machine (fsm). The scheme has low area overhead and competes well with scan methods in its ability to initialize and observe circuit states. The states of the machine are assigned a pair of binary values using a novel split coding system. The purpose of the encoding is to ease navigation between any pair of states using a combination of …