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2005

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Articles 931 - 960 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Measuring Reaction Probability Ratios To Simulate Neutron-Induced Cross-Sections Of Short-Lived Nuclei, C. Plettner, H. Ai, C. W. Beausang, L. A. Bernstein, L. Ahle, H. Amro, M. Babilon, J. T. Burke, J. A. Caggiano, R. F. Casten, J. A. Church, J. R. Cooper, B. Crider, G. Gurdal, A. Heinz, E. A. Mccutchan, K. Moody, J. A. Punyon, J. Qian, J. J. Ressler, A. Schiller, E. Williams, W. Younes Sep 2005

Measuring Reaction Probability Ratios To Simulate Neutron-Induced Cross-Sections Of Short-Lived Nuclei, C. Plettner, H. Ai, C. W. Beausang, L. A. Bernstein, L. Ahle, H. Amro, M. Babilon, J. T. Burke, J. A. Caggiano, R. F. Casten, J. A. Church, J. R. Cooper, B. Crider, G. Gurdal, A. Heinz, E. A. Mccutchan, K. Moody, J. A. Punyon, J. Qian, J. J. Ressler, A. Schiller, E. Williams, W. Younes

Physics Faculty Publications

Measuring the neutron-induced fission cross-sections of short-lived nuclei represents an experimental challenge due to target activity and the low intensity of neutron beams. One way to alleviate the problems inherent in the direct measurement is to use the surrogate method, where one measures the decay probability of the same compound nucleus formed using a charged beam and a stable target. The decay probability of the compound nucleus is then used to estimate the neutron-induced cross-section. As an extension to the surrogate method, we introduce a new method of reporting the fission probabilities of two compound nuclei as a ratio, which …

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Quadrupole Moment Measurements Of Tsd1 And Tsd2 Bands In 167Lu, G. Gurdal, H. Amro, C. W. Beausang, D. S. Brenner, M. P. Carpenter, R. F. Casten, C. Engelhardt, G. B. Hagemann, C. R. Hansen, D. J. Hartley, B. Herskind, H. Hubel, T. L. Khoo, T. Lauritsen, W. C. Ma, D. A. Meyer, E. F. Moore, A. Neusser, P. Bringel, D. G. Roux, G. Sletten, R. B. Yadav, Y. Zhang Sep 2005

Quadrupole Moment Measurements Of Tsd1 And Tsd2 Bands In 167Lu, G. Gurdal, H. Amro, C. W. Beausang, D. S. Brenner, M. P. Carpenter, R. F. Casten, C. Engelhardt, G. B. Hagemann, C. R. Hansen, D. J. Hartley, B. Herskind, H. Hubel, T. L. Khoo, T. Lauritsen, W. C. Ma, D. A. Meyer, E. F. Moore, A. Neusser, P. Bringel, D. G. Roux, G. Sletten, R. B. Yadav, Y. Zhang

Physics Faculty Publications

The triaxial strongly deformed (TSD) bands in 167Lu were populated by the 123Sb(48Ca, 4n) reaction with a beam energy of 203 MeV. Gamma rays, requiring fivefold or more in prompt coincidence, were detected with the Gammasphere spectrometer. Of particular interests are TSD bands 1 and 2 which have previously been interpreted as zero phonon and one phonon wobbling bands, respectively. Using the Doppler shift attenuation method (DSAM), a preliminary transition quadrupole moment of 6.9+0.3−0.3 eb was extracted for the TSD1 band. Data analysis continues for TSD2 which is considerably more weakly populated.

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Sink-To-Sensors Congestion Control, Ramanuja Vedantham, Raghupathy Sivakumar, Seung Jong Park Sep 2005

Sink-To-Sensors Congestion Control, Ramanuja Vedantham, Raghupathy Sivakumar, Seung Jong Park

Computer Science Faculty Research & Creative Works

The problem of congestion in sensor networks is significantly different from conventional ad-hoc networks and has not been studied to any great extent thus far. In this paper, we focus on providing congestion control from the sink to the sensors in a sensor field. We identify the different reasons for congestion from the sink to the sensors and show the uniqueness of the problem in sensor network environments. We propose a scalable, distributed approach that addresses congestion from the sink to the sensors in a sensor network. Through ns2 based simulations, we evaluate the proposed framework, and show that it …

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Isomers And Seniority In The Trans-Pb Nuclei, J. J. Ressler, C. W. Beausang, R. F. Casten, N. V. Zamfir, H. Ai, H. Amro, M. Babilon, R. Cakirli, J. A. Caggiano, G. Gurdal, A. Heinz, R. O. Hughes, S. D. Langdown, E. A. Mccutchan, D. A. Meyer, C. Plettner, J. Qian, P. H. Regan, M.J. S. Sciacchitano, N. J. Thomas, E. Williams, A. Yamamoto Sep 2005

Isomers And Seniority In The Trans-Pb Nuclei, J. J. Ressler, C. W. Beausang, R. F. Casten, N. V. Zamfir, H. Ai, H. Amro, M. Babilon, R. Cakirli, J. A. Caggiano, G. Gurdal, A. Heinz, R. O. Hughes, S. D. Langdown, E. A. Mccutchan, D. A. Meyer, C. Plettner, J. Qian, P. H. Regan, M.J. S. Sciacchitano, N. J. Thomas, E. Williams, A. Yamamoto

Physics Faculty Publications

Low-energy excited states of 210Ra and 208Ra were investigated at the Wright Nuclear Structure Laboratory of Yale University. Fusion evaporation recoils were selected using the gas-filled spectrometer, SASSYER. Delayed γ -rays, following isomeric decays, were detected at the focal plane of SASSYER with a small array of HPGe detectors. Transitions following the proposed J π = 8+ isomers were observed, and the half-lives measured. The experiments are discussed and results compared to expectations from the seniority scheme.

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Spatial And Temporal Variations In Epikarst Storage And Flow In South Central Kentucky’S Pennyroyal Plateau Sinkhole Plain, Chris Groves, Carl Bolster, Joe Meiman Sep 2005

Spatial And Temporal Variations In Epikarst Storage And Flow In South Central Kentucky’S Pennyroyal Plateau Sinkhole Plain, Chris Groves, Carl Bolster, Joe Meiman

Earth, Environmental, and Atmospheric Sciences Faculty Publications

The well-developed karst aquifers of south central Kentucky’s Pennyroyal Plateau are impacted by contamination from animal waste and other agricultural inputs. Understanding fate and transport of these and other contaminants first requires knowledge of flow and storage behaviors within the impacted aquifers, complicated by significant heterogeneity, anisotropy, and rapid temporal variations. Here we report on spatial and temporal variations in vadose zone flow and water chemistry (or quality) within Cave Spring Caverns, Kentucky beneath agricultural lands on a well-developed sinkhole plain. Weekly sampling of three underground waterfalls show statistically significant differences in water quality, though the sites are laterally within …

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Generalized Williamson And Wallis-Whiteman Constructions For Improved Square Order-8 Co Stbcs, Le Chung Tran, Tadeusz A. Wysocki, Jennifer Seberry, A. Mertins, Sarah A. Spence Sep 2005

Generalized Williamson And Wallis-Whiteman Constructions For Improved Square Order-8 Co Stbcs, Le Chung Tran, Tadeusz A. Wysocki, Jennifer Seberry, A. Mertins, Sarah A. Spence

Faculty of Informatics - Papers (Archive)

Constructions of square, maximum rate Complex Orthogonal Space-Time Block Codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols equally disperse through transmit antennas. Those codes, referred to as the improved square CO STBCs, have the advantages that …

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Simultaneous Map Estimation Of Inhomogeneity And Segmentation Of Brain Tissues From Mr Images, Wanqing Li, C. Desilver, Y. Attikiouzel Sep 2005

Simultaneous Map Estimation Of Inhomogeneity And Segmentation Of Brain Tissues From Mr Images, Wanqing Li, C. Desilver, Y. Attikiouzel

Faculty of Informatics - Papers (Archive)

Intrascan and interscan intensity inhomogeneities have been identified as a common source of making many advanced segmentation techniques fail to produce satisfactory results in separating brains tissues from multi-spectral magnetic resonance (MR) images. A common solution is to correct the inhomogeneity before applying the segmentation techniques. This paper presents a method that is able to achieve simultaneous semi-supervised MAP (maximum a-posterior probability) estimation of the inhomogeneity field and segmentation of brain tissues, where the inhomogeneity is parameterized. Our method can incorporate any available incomplete training data and their contribution can be controlled in a flexible manner and therefore the segmentation …

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Debye Series Analysis Of Scattering Of A Plane Wave By A Spherical Bragg Grating, James A. Lock Sep 2005

Debye Series Analysis Of Scattering Of A Plane Wave By A Spherical Bragg Grating, James A. Lock

Physics Faculty Publications

The Debye series decomposition of the partial-wave scattering amplitudes of a multilayer sphere is derived. The partial-wave transmission and reflection terms appearing in the Debye series are multiple-scattering amplitudes written in terms of four basic quantities and combined together layer by layer in an identical way. The resulting expressions are then used to calculate the scattered intensity of a spherical Bragg grating covering a dielectric core particle and to analyze a number of new structures appearing in the scattered intensity. (c) 2005 Optical Society of America.

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Abundance Of Elements Beyond The Iron Group In Cool Do White Dwarfs, Pierre Chayer, Stéphane Vennes, Jean Jean François, Jeffrey W. Kruk Sep 2005

Abundance Of Elements Beyond The Iron Group In Cool Do White Dwarfs, Pierre Chayer, Stéphane Vennes, Jean Jean François, Jeffrey W. Kruk

Aerospace, Physics, and Space Science Faculty Publications

We report the presence of elements beyond the iron group in the atmospheres of the cool DO white dwarfs HD 149499 B and HZ 21. Photospheric lines of germanium (Z = 32), arsenic (33), selenium (34), tin (50), tellurium (52), iodine (53), and perhaps bromine (35) are observed in ultraviolet spectra of HD 149499 B obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE), the Goddard High Resolution Spectrograph (GHRS), and the International Ultraviolet Explorer. Germanium, arsenic, and tellurium are also observed in FUSE and GHRS spectra of HZ 21. Light elements such as carbon, silicon, phosphorus, and sulfur are present …

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First Glimpse Results On The Stellar Structure Of The Galaxy., R. Benjamin, E. Churchwell, B. Babler, R. Indebetouw, M. Meade, B. Whitney, C. Watson, M. Wolfire, M. Wolff, Richard Ignace, T. Bania, S. Bracker, D. Clemens, L. Chomiuk, M. Cohen, J. Dickey, J. Jackson, H. Kobulnicky, E. Mercer, J. Mathis, S. Stolovy, B. Uzpen Sep 2005

First Glimpse Results On The Stellar Structure Of The Galaxy., R. Benjamin, E. Churchwell, B. Babler, R. Indebetouw, M. Meade, B. Whitney, C. Watson, M. Wolfire, M. Wolff, Richard Ignace, T. Bania, S. Bracker, D. Clemens, L. Chomiuk, M. Cohen, J. Dickey, J. Jackson, H. Kobulnicky, E. Mercer, J. Mathis, S. Stolovy, B. Uzpen

ETSU Faculty Works

The GLIMPSE (Galactic Legacy Mid-Plane Survey Extraordinaire) Point Source Catalog of ~ 30 million mid-infrared sources towards the inner Galaxy, 10 < |l| < 65 degrees and |b| < 1 degree, was used to determine the distribution of stars in Galactic longitude, latitude, and apparent magnitude. The counts versus longitude can be approximated by the modified Bessel function N=N_0*(l/l_0)*K_1(l/l_0), where l_0 is insensitive to limiting magnitude, band choice, and side of Galactic center: l_0= 17-30 degrees with a best fit value in the the 4.5 micron band of l_0=24 +/- 4 degrees. Modeling the source distribution as an exponential disk yields a radial scale length of H= 3.9 +/- 0.6 kpc. There is a pronounced north-south asymmetry in source counts for |l| < 30 degrees, with ~ 25% more stars in the north. For l=10-30 degrees, there is a strong enhancement of stars of m= 11.5-13.5 mag. A linear bar passing through the Galactic center with half-length R_bar=4.4 +/- 0.5 kpc, tilted by phi=44 +/- 10 degrees to the Sun-Galactic Center line, provides the simplest interpretation of this data. We examine the possibility that enhanced source counts at l=26-28 degrees, 31.5-34 degrees, and 306-309 degrees are related to Galactic spiral structure. Total source counts are depressed in regions where the counts of red objects (m_K-m_[8.0] >3) peak. In these areas, the counts are reduced by extinction due to molecular gas and/or high diffuse backgrounds associated with star formation.

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First Glimpse Results On The Stellar Structure Of The Galaxy., R. A. Benjamin, E. Churchwell, B. L. Babler, R. Indebetouw, M. R. Meade, B. A. Whitney, C. Watson, M. G. Wolfire, M. J. Wolff, R. Ignace, T. M. Bania, S. Bracker, D. P. Clemens, L. Chomiuk, M. Cohen, J. M. Dickey, J. M. Jackson, H. A. Kobulnicky, E. P. Mercer, J. S. Mathis, S. R. Stolovy, B. Uzpen Sep 2005

First Glimpse Results On The Stellar Structure Of The Galaxy., R. A. Benjamin, E. Churchwell, B. L. Babler, R. Indebetouw, M. R. Meade, B. A. Whitney, C. Watson, M. G. Wolfire, M. J. Wolff, R. Ignace, T. M. Bania, S. Bracker, D. P. Clemens, L. Chomiuk, M. Cohen, J. M. Dickey, J. M. Jackson, H. A. Kobulnicky, E. P. Mercer, J. S. Mathis, S. R. Stolovy, B. Uzpen

Richard Ignace

The GLIMPSE (Galactic Legacy Mid-Plane Survey Extraordinaire) Point Source Catalog of ~ 30 million mid-infrared sources towards the inner Galaxy, 10 < |l| < 65 degrees and |b| < 1 degree, was used to determine the distribution of stars in Galactic longitude, latitude, and apparent magnitude. The counts versus longitude can be approximated by the modified Bessel function N=N_0*(l/l_0)*K_1(l/l_0), where l_0 is insensitive to limiting magnitude, band choice, and side of Galactic center: l_0= 17-30 degrees with a best fit value in the the 4.5 micron band of l_0=24 +/- 4 degrees. Modeling the source distribution as an exponential disk yields a radial scale length of H= 3.9 +/- 0.6 kpc. There is a pronounced north-south asymmetry in source counts for |l| < 30 degrees, with ~ 25% more stars in the north. For l=10-30 degrees, there is a strong enhancement of stars of m= 11.5-13.5 mag. A linear bar passing through the Galactic center with half-length R_bar=4.4 +/- 0.5 kpc, tilted by phi=44 +/- 10 degrees to the Sun-Galactic Center line, provides the simplest interpretation of this data. We examine the possibility that enhanced source counts at l=26-28 degrees, 31.5-34 degrees, and 306-309 degrees are related to Galactic spiral structure. Total source counts are depressed in regions where the counts of red objects (m_K-m_[8.0] >3) peak. In these areas, the counts are reduced by extinction due to molecular gas and/or high diffuse backgrounds associated with star formation.

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Cross-Validated Bagged Prediction Of Survival, Sandra E. Sinisi, Romain Neugebauer, Mark J. Van Der Laan Sep 2005

Cross-Validated Bagged Prediction Of Survival, Sandra E. Sinisi, Romain Neugebauer, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In this article, we show how to apply our previously proposed Deletion/Substitution/Addition algorithm in the context of right-censoring for the prediction of survival. Furthermore, we introduce how to incorporate bagging into the algorithm to obtain a cross-validated bagged estimator. The method is used for predicting the survival time of patients with diffuse large B-cell lymphoma based on gene expression variables.

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Imaging Solar Neutrons Below 10 Mev In The Inner Heliosphere, U Bravar Sep 2005

Imaging Solar Neutrons Below 10 Mev In The Inner Heliosphere, U Bravar

Space Science Center

Inner heliosphere measurements of the Sun can be conducted with the proposed Solar Sentinel spacecraft and mission. One of the key measurements that can be made inside the orbit of the Earth is that of lower energy neutrons that arise in flares from nuclear reactions. Solar flare neutrons below 10 MeV suffer heavy weak-decay losses before reaching 1 AU. For heliocentric radii as close as 0.3 AU, the number of surviving neutrons from a solar event is dramatically greater. Neutrons from 1-10 MeV provide a new measure of heavy ion interactions at low energies, where the vast majority of energetic …

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Red Rock Desert Learning Center: The Vision, Red Rock Desert Learning Center Sep 2005

Red Rock Desert Learning Center: The Vision, Red Rock Desert Learning Center

Oliver Ranch Project

A public meeting will be held to introduce the Red Rock Learning Center, the first outdoor education center for local fifth grade children in Southern Nevada. Designed to enhance math and science skills, the school will be built in the Red Rock Canyon National Conservation Area. It will feature a curriculum that teaches children about conservation and the natural world by increasing their knowledge and understanding of the Mojave Desert ecosystem.

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The Effect Of Particles On Dynamic Recrystallization And Fabric Development Of Granular Ice During Creep, Min Song, Ian Baker, David M. Cole Sep 2005

The Effect Of Particles On Dynamic Recrystallization And Fabric Development Of Granular Ice During Creep, Min Song, Ian Baker, David M. Cole

Dartmouth Scholarship

The mechanical behavior and microstructural evolution of laboratory-prepared, particle-free fresh-water ice and ice with 1 wt.% (~0.43 vol.%) silt-sized particles were investigated under creep with a stress level of 1.45 MPa at −10°C. The particles were present both within the grains and along the grain boundaries. The creep rates of specimens with particles were always higher than those of particle-free ice. Dynamic recrystallization occurred for both sets of specimens, with new grains nucleating along grain boundaries in the early stages of creep. The ice with particles showed a higher nucleation rate. This resulted in a smaller average grain-size for the …

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The Open Network Laboratory (A Resource For High Performance Networking Research), John Dehart, Fred Kuhns, Jyoti Parwatikar, Jonathan Turner, Ken Wong Sep 2005

The Open Network Laboratory (A Resource For High Performance Networking Research), John Dehart, Fred Kuhns, Jyoti Parwatikar, Jonathan Turner, Ken Wong

All Computer Science and Engineering Research

The Open Network Laboratory (ONL) is a remotely accessible network testbed designed to enable network researchers to conduct experiments using high performance routers and applications. ONL™s Remote Laboratory Interface (RLI) allows users to easily configure a network topology, initialize and modify the routers™ routing tables, packet classification tables and queuing parameters. It also enables users to add software plugins to the embedded processors available at each of the routers™ ports, enabling the introduction of new functionality. The routers provide a large number of built-in counters to track various aspects of system usage, and the RLI software makes these available through …

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Semiparametric Estimation In General Repeated Measures Problems, Xihong Lin, Raymond J. Carroll Sep 2005

Semiparametric Estimation In General Repeated Measures Problems, Xihong Lin, Raymond J. Carroll

Harvard University Biostatistics Working Paper Series

This paper considers a wide class of semiparametric problems with a parametric part for some covariate effects and repeated evaluations of a nonparametric function. Special cases in our approach include marginal models for longitudinal/clustered data, conditional logistic regression for matched case-control studies, multivariate measurement error models, generalized linear mixed models with a semiparametric component, and many others. We propose profile-kernel and backfitting estimation methods for these problems, derive their asymptotic distributions, and show that in likelihood problems the methods are semiparametric efficient. While generally not true, with our methods profiling and backfitting are asymptotically equivalent. We also consider pseudolikelihood methods …

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The Optimal Discovery Procedure: A New Approach To Simultaneous Significance Testing, John D. Storey Sep 2005

The Optimal Discovery Procedure: A New Approach To Simultaneous Significance Testing, John D. Storey

UW Biostatistics Working Paper Series

Significance testing is one of the main objectives of statistics. The Neyman-Pearson lemma provides a simple rule for optimally testing a single hypothesis when the null and alternative distributions are known. This result has played a major role in the development of significance testing strategies that are used in practice. Most of the work extending single testing strategies to multiple tests has focused on formulating and estimating new types of significance measures, such as the false discovery rate. These methods tend to be based on p-values that are calculated from each test individually, ignoring information from the other tests. As …

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Quantum Amplified Isomerization:  A New Concept For Polymeric Optical Materials, Jason G. Gillmore, J. D. Neiser, K. A. Mcmanus, Y. Roh, G. W. Dombrowski, T. G. Brown, J. P. Dinnocenzo, S. Farid, D. R. Robello Sep 2005

Quantum Amplified Isomerization:  A New Concept For Polymeric Optical Materials, Jason G. Gillmore, J. D. Neiser, K. A. Mcmanus, Y. Roh, G. W. Dombrowski, T. G. Brown, J. P. Dinnocenzo, S. Farid, D. R. Robello

Faculty Publications

The preparation and evaluation of a new class of photoresponsive polymers are described on the basis of a process called quantum amplified isomerization (QAI). The QAI process utilizes photoinitiated, cation radical isomerization chemistry in a polymeric medium. Two classes of materials are described:  one where the QAI reactant is molecularly doped in the polymer matrix and another where the reactant is part of a functionalized polymer. Quantum yield experiments demonstrate that the isomerization reaction can proceed by a chain process with modest efficiencies. Photochemical conversion experiments show that high extents of conversion of the QAI reactants are possible. The rate …

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Galactic Open Clusters, Ted Von Hippel Sep 2005

Galactic Open Clusters, Ted Von Hippel

Publications

The study of open clusters has a classic feel to it since the subject predates anyone alive today. Despite the age of this topic, I show via an ADS search that its relevance and importance in astronomy has grown faster in the last few decades than astronomy in general. This is surely due to both technical reasons and the interconnection of the field of stellar evolution to many branches of astronomy. In this review, I outline what we know today about open clusters and what they have taught us about a range of topics from stellar evolution to Galactic structure …

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Origin Of Enantioselection In Chiral Alcohol Oxidation Catalyzed By Pd[(–)-Sparteine]Cl2, J. A. Mueller, Anne Cowell, Bert D. Chandler, M. S. Sigman Sep 2005

Origin Of Enantioselection In Chiral Alcohol Oxidation Catalyzed By Pd[(–)-Sparteine]Cl2, J. A. Mueller, Anne Cowell, Bert D. Chandler, M. S. Sigman

Chemistry Faculty Research

A kinetic investigation into the origin of enantioselectivity for the Pd[(–)-sparteine]Cl2-catalyzed aerobic oxidative kinetic resolution (OKR) is reported. A mechanism to account for a newly discovered chloride dissociation from Pd[(–)-sparteine]Cl2 prior to alcohol binding is proposed. The mechanism includes (1) chloride dissociation from Pd[(–)-sparteine]Cl2 to form cationic Pd(–)-sparteine]Cl, (2) alcohol binding, (3) deprotonation of Pd-bound alcohol to form a Pd-alkoxide, and (4) β-hydride elimination of Pd–alkoxide to form ketone product and a Pd–hydride. Utilizing the addition of (–)-sparteine HCl to control the [Cl–] and [H+] and the resulting derived rate law, …

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Chemistry Weekly, Volume 1 Issue 23, September 5 - 9, 2005 Sep 2005

Chemistry Weekly, Volume 1 Issue 23, September 5 - 9, 2005

Department of Chemistry: Department Information

COLLOQUIUM, Professor Bruce S. Hudson: “Vibrations of Molecules in Solids: Periodic DFT and Inelastic Neutron Scattering”
NEW CHEMISTRY DEPARTMENT STAFF; UNL EMPLOYEE SERVICE AWARDS; Hamilton Hall - Renovation News;
EHS COLLOQUIUM SERIES FOR RESEARCH PIs presents “Personal Protective Equipment (Laboratory),” Dr. Jim Zeigler, DuPont Personal Protection;
SEMINAR Sponsored By: Center for Materials Research & Analysis / NSF-MRSEC Title: Q & A on Synthesis of Nanoparticles and Nanotubes Speaker: Professor Stephen O'Brien, Dept. of Materials Science & Engineering, Columbia University;
Nebraska MRSEC 3rd Annual Review & Symposium—SEPT. 20-21

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Linear Equality Constraints And Homomorphous Mappings In Pso, Christopher K. Monson, Kevin Seppi Sep 2005

Linear Equality Constraints And Homomorphous Mappings In Pso, Christopher K. Monson, Kevin Seppi

Faculty Publications

We present a homomorphous mapping that converts problems with linear equality constraints into fully unconstrained and lower-dimensional problems for optimization with PSO. This approach, in contrast with feasibility preservation methods, allows any unconstrained optimization algorithm to be applied to a problem with linear equality constraints, making available tools that are known to be effective and simplifying the process of choosing an optimizer for these kinds of constrained problems. The application of some PSO algorithms to a problem that has undergone the mapping presented here is shown to be more effective and more consistent than other approaches to handling linear equality …

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Doppler Shift As A Tool For Studies Of Resonant (P,N) Reactions With Ribs: Spectroscopy Of 7he, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wöhr Sep 2005

Doppler Shift As A Tool For Studies Of Resonant (P,N) Reactions With Ribs: Spectroscopy Of 7he, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wöhr

Faculty Publications

We report on a new methods for studies of neutron rich systems through resonant (p,n) reaction with radioactive ion beams. A specific example of the spectroscopy of 7He and future application of the proposed methods are discussed.

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A-Stripping Reactions With Exotic Nuclei: 12c7be,3he)16o, H. Amro, F. D. Becchetti, Yu Chen, H. Jiang, M. Ojaruega, H. C. Griffin, J. J. Kolata, B. B. Skorodumov, J. D. Hinnefeld, Graham F. Peaslee Sep 2005

A-Stripping Reactions With Exotic Nuclei: 12c7be,3he)16o, H. Amro, F. D. Becchetti, Yu Chen, H. Jiang, M. Ojaruega, H. C. Griffin, J. J. Kolata, B. B. Skorodumov, J. D. Hinnefeld, Graham F. Peaslee

Faculty Publications

The 12C(7Be,3He)16O reaction has been studied at E(7Be)=34 MeV. At this energy this Reaction exhibits a high selectivity for populating known α‐cluster states in 16O (Jπ = 0+,3−,2+,1−,4+, and 6+). The angular distributions for the 0+,3−,2+,1−, and 4+ levels are obtained at forward angles. Likewise, large reaction rates were measured for the 3He transfer channel, i.e. 12C(7Be,α)15O

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Caster: A Concept For A Black Hole Finder Probe Based On The Use Of New Scintillator Technologies, Mark L. Mcconnell, Peter F. Bloser, G L. Case, M L. Cherry, J Cravens, T G. Guzik, K Hurley, R M. Kippen, John R. Macri, R S. Miller, W Paciesas, James M. Ryan, B Schaefer, J G. Stacy, W T. Vestrand, J P. Wefel Sep 2005

Caster: A Concept For A Black Hole Finder Probe Based On The Use Of New Scintillator Technologies, Mark L. Mcconnell, Peter F. Bloser, G L. Case, M L. Cherry, J Cravens, T G. Guzik, K Hurley, R M. Kippen, John R. Macri, R S. Miller, W Paciesas, James M. Ryan, B Schaefer, J G. Stacy, W T. Vestrand, J P. Wefel

Space Science Center

The primary scientific mission of the Black Hole Finder Probe (BHFP), part of the NASA Beyond Einstein program, is to survey the local Universe for black holes over a wide range of mass and accretion rate. One approach to such a survey is a hard X-ray coded-aperture imaging mission operating in the 10-600 keV energy band, a spectral range that is considered to be especially useful in the detection of black hole sources. The development of new inorganic scintillator materials provides improved performance (for example, with regards to energy resolution and timing) that is well suited to the BHFP science …

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Gas Micro-Well Track Imaging Detectors For Gamma-Ray Astronomy, Peter F. Bloser, S Hunter, James M. Ryan, Mark L. Mcconnell, John R. Macri Sep 2005

Gas Micro-Well Track Imaging Detectors For Gamma-Ray Astronomy, Peter F. Bloser, S Hunter, James M. Ryan, Mark L. Mcconnell, John R. Macri

Space Science Center

We describe our program to develop gas micro-well detectors (MWDs) as three-dimensional charged particle trackers for use in advanced gamma-ray telescope concepts. A micro-well detector consists of an array of individual micro-patterned gas proportional counters opposite a planar drift electrode. The well anodes and cathodes may be connected in X and Y strips, respectively, to provide two-dimensional imaging. When combined with transient digitizer electronics, which record the time signature of the charge collected in the wells of each strip, full three-dimensional reconstruction of charged-particle tracks in large gas volumes is possible. Such detectors hold great promise for advanced Compton telescope …

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Mega: A Medium-Energy Gamma-Ray Astronomy Mission Concept, Peter F. Bloser, James M. Ryan, Mark L. Mcconnell, John R. Macri, U Bravar, G Kanbach, R Andritsche, M Ajello, A Zoglauer, S Hunter, B F. Phlips, Eric Wulf, Dieter H. Hartman, R S. Miller, W Paciesas, Allen Zych, R M. Kippen, W T. Vestrand, M L. Cherry, T G. Guzik, J G. Stacy, J P. Wefel, V Reglero, G Dicocco, J Cravens Sep 2005

Mega: A Medium-Energy Gamma-Ray Astronomy Mission Concept, Peter F. Bloser, James M. Ryan, Mark L. Mcconnell, John R. Macri, U Bravar, G Kanbach, R Andritsche, M Ajello, A Zoglauer, S Hunter, B F. Phlips, Eric Wulf, Dieter H. Hartman, R S. Miller, W Paciesas, Allen Zych, R M. Kippen, W T. Vestrand, M L. Cherry, T G. Guzik, J G. Stacy, J P. Wefel, V Reglero, G Dicocco, J Cravens

Space Science Center

The Medium Energy Gamma-ray Astronomy (MEGA) telescope concept will soon be proposed as a MIDEX mission. This mission would enable a sensitive all-sky survey of the medium-energy gamma-ray sky (0.4 - 50 MeV) and bridge the huge sensitivity gap between the COMPTEL and OSSE experiments on the Compton Gamma Ray Observatory, the SPI and IBIS instruments on INTEGRAL, and the visionary Advanced Compton Telescope (ACT) mission. The scientific goals include, among other things, compiling a much larger catalog of sources in this energy range, performing far deeper searches for supernovae, better measuring the galactic continuum and line emissions, and identifying …

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A Handheld Polarimeter For Aerosol Remote Sensing, James W. Frost, Fouad Nasraddine, J. Rodriguez, I. Andino, Brian Cairns Sep 2005

A Handheld Polarimeter For Aerosol Remote Sensing, James W. Frost, Fouad Nasraddine, J. Rodriguez, I. Andino, Brian Cairns

Publications and Research

In this paper we show how measurements made by a simple handheld polarimeter in conjunction with automated sunsky radiometers can be used to effectively constrain the real part of the complex refractive index of aerosols. We find that even measurements over a limited angular range near 90° scattering angle are sufficient for this purpose. We also note that because of the effect of surface reflectance on the observed degree of linear polarization (DOLP) it is sensible to select spectral bands for these measurements for which the surface is relatively dark and homogeneous (i.e. wavelengths shorter than 700 nm are to …

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Measurement Of Ɓ(T→Wb)/ Ɓ(T→Wb) At The Collider Detector At Fermilab, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Sep 2005

Measurement Of Ɓ(T→Wb)/ Ɓ(T→Wb) At The Collider Detector At Fermilab, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the ratio of top-quark branching fractions R=Ɓ (t→Wb)/ Ɓ(t→Wq), where q can be a b, s, or a d quark, using lepton-plus-jets and dilepton data sets with an integrated luminosity of ~162 pb-1 collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t t̅ events with different multiplicity of identified secondary vertices. We set a lower limit of R>0.61 at 95% confidence level.

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