2004 Electron Donor Acceptor Interactions Gordon Conference - August 8-13, 2004 (open access)

2004 Electron Donor Acceptor Interactions Gordon Conference - August 8-13, 2004

The 2004 Gordon Conference on Donor/Acceptor Interactions will take place at Salve Regina University in Newport, Rhode Island on August 8-13, 2004. The conference will be devoted to the consequences of charge interaction and charge motion in molecular and materials systems.
Date: September 14, 2005
Creator: GUILFORD JONES BOSTON UNIVERSITY PHOTONICS CENTER 8 ST. MARY'S ST BOSTON, MA 02215
Object Type: Article
System: The UNT Digital Library
Comment on Form Factor Shape and Extraction of $|V_{ub}|$ from $B\to\pi l \nu$ (open access)

Comment on Form Factor Shape and Extraction of $|V_{ub}|$ from $B\to\pi l \nu$

We point out that current experimental data for partial B {yields} {pi}l{nu} branching fractions reduce the theoretical input required for a precise extraction of |V{sub ub}| to the form-factor normalization at a single value of the pion energy. Different parameterizations of the form factor shape leading to this conclusion are compared and the role of dispersive bounds on heavy-to-light form factors is clarified.
Date: September 14, 2005
Creator: Becher, Thomas & Hill, Richard J.
Object Type: Article
System: The UNT Digital Library
Comparative genome analysis of Bacillus cereus group genomes withBacillus subtilis (open access)

Comparative genome analysis of Bacillus cereus group genomes withBacillus subtilis

Genome features of the Bacillus cereus group genomes (representative strains of Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis sub spp israelensis) were analyzed and compared with the Bacillus subtilis genome. A core set of 1,381 protein families among the four Bacillus genomes, with an additional set of 933 families common to the B. cereus group, was identified. Differences in signal transduction pathways, membrane transporters, cell surface structures, cell wall, and S-layer proteins suggesting differences in their phenotype were identified. The B. cereus group has signal transduction systems including a tyrosine kinase related to two-component system histidine kinases from B. subtilis. A model for regulation of the stress responsive sigma factor sigmaB in the B. cereus group different from the well studied regulation in B. subtilis has been proposed. Despite a high degree of chromosomal synteny among these genomes, significant differences in cell wall and spore coat proteins that contribute to the survival and adaptation in specific hosts has been identified.
Date: September 14, 2005
Creator: Anderson, Iain; Sorokin, Alexei; Kapatral, Vinayak; Reznik, Gary; Bhattacharya, Anamitra; Mikhailova, Natalia et al.
Object Type: Article
System: The UNT Digital Library
Effective Interactions and Operators in Nuclei within the No-Core Shell Model (open access)

Effective Interactions and Operators in Nuclei within the No-Core Shell Model

We review the application of effective operator formalism to the ab initio no core shell model (NCSM). For short-range operators, such as the nucleon-nucleon potential, the unitary-transformation method works extremely well at the two-body cluster approximation and good results are obtained for the binding energies and excitation spectra of light nuclei (A {<=} 16). However, for long-range operators, such as the radius or the quadrupole moment, performing this unitary transformation at the two-body cluster level, does not include the higher-order correlations needed to renormalize these long-range operators adequately. Usually, such correlations can be obtained either by increasing the order of the cluster approximation, or by increasing the model space. We will discuss the difficulties of these approaches as well as alternate possible solutions for including higher-order correlations in small model spaces.
Date: September 14, 2005
Creator: Barrett, B; Navratil, P; Stetcu, I & Vary, J
Object Type: Article
System: The UNT Digital Library
Equilibrium Beam Invariants of an Electron Storage Ring with Linear x-y Coupling (open access)

Equilibrium Beam Invariants of an Electron Storage Ring with Linear x-y Coupling

In accelerators, it is common that the motion of the horizontal x-plane is coupled to that of the vertical y-plane. Such coupling will induce tune shifts and can cause instabilities. The damping and diffusion rates are also affected, which in turn will lead to a change in the equilibrium invariants. With the perturbative approach which is also used for synchrobetatron coupling [B. Nash, J.Wu, and A. Chao, work in progress], we study the x-y coupled case in this paper. Starting from the one-turn map, we give explicit formulae for the tune shifts, damping and diffusion rates, and the equilibrium invariants. We focus on the cases where the system is near the integer or half integer, and sum or difference resonances where small coupling can cause a large change in the beam distribution.
Date: September 14, 2005
Creator: Wu, Juhao; Nash, B.E. & Chao, A.W.
Object Type: Article
System: The UNT Digital Library
Gas Storage Technology Consortium Quarterly Report: April-June 2005 (open access)

Gas Storage Technology Consortium Quarterly Report: April-June 2005

Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide …
Date: September 14, 2005
Creator: Morrison, Joel
Object Type: Report
System: The UNT Digital Library
High-Brightness Milestone Report to DOE OFES, FY05 Q4 (open access)

High-Brightness Milestone Report to DOE OFES, FY05 Q4

We have met this milestone by making measurements of electrons, as described in our FY05 Q3 Milestone Report, and simulating the same conditions with the WARP/POSINST code. This code has been developed over the last three years, by adding self-consistent electron and gas populations to the beam-dynamics particle-in-cell code, WARP, and combining it with the electron-cloud code from LBNL, POSINST. This code development effort has advanced to the point where almost all elements of a comprehensive ''roadmap'' are available. The WARP simulations shown here replicate experimental results, with agreement ranging from semi-quantitative agreement to close quantitative agreement.
Date: September 14, 2005
Creator: Molvik, A W
Object Type: Report
System: The UNT Digital Library
Improved Electron Yield and Spin-Polarizaton from III-V Photocathodes Via Bias Enhanced Carrier Drift (open access)

Improved Electron Yield and Spin-Polarizaton from III-V Photocathodes Via Bias Enhanced Carrier Drift

Spin-polarized electrons are commonly used in high energy physics. Future work will benefit from greater polarization. Polarizations approaching 90% have been achieved at the expense of yield. The primary paths to higher polarization are material design and electron transport. Our work addresses the latter. Photoexcited electrons may be preferentially emitted or suppressed by an electric field applied across the active region. We are tuning this forward bias for maximum polarization and yield, together with other parameters, e.g., doping profile. Preliminary measurements have been carried out on bulk and thin film GaAs. As expected, the yield change far from the bandgap is quite large for bulk material. The bias is applied to the bottom (non-activated) side of the cathode so that the accelerating potential as measured with respect to the ground potential chamber walls is unchanged for different front-to-back cathode bias values. The size of the bias to cause an appreciable effect is rather small reflecting the low drift kinetic energy in the zero bias case.
Date: September 14, 2005
Creator: Mulhollan, Gregory A.; Bierman, John; Brachmann, Axel; Clendenin, James E.; Garwin, Edward; Kirby, Robert et al.
Object Type: Article
System: The UNT Digital Library
Macroscopic Subdivision of Silica Aerogel Collectors for Sample Return Missions (open access)

Macroscopic Subdivision of Silica Aerogel Collectors for Sample Return Missions

Silica aerogel collector tiles have been employed for the collection of particles in low Earth orbit and, more recently, for the capture of cometary particles by NASA's Stardust mission. Reliable, reproducible methods for cutting these and future collector tiles from sample return missions are necessary to maximize the science output from the extremely valuable embedded particles. We present a means of macroscopic subdivision of collector tiles by generating large-scale cuts over several centimeters in silica aerogel with almost no material loss. The cut surfaces are smooth and optically clear allowing visual location of particles for analysis and extraction. This capability is complementary to the smaller-scale cutting capabilities previously described [Westphal (2004), Ishii (2005a, 2005b)] for removing individual impacts and particulate debris in tiny aerogel extractions. Macroscopic cuts enable division and storage or distribution of portions of aerogel tiles for immediate analysis of samples by certain techniques in situ or further extraction of samples suited for other methods of analysis.
Date: September 14, 2005
Creator: Ishii, H A & Bradley, J P
Object Type: Article
System: The UNT Digital Library
MEMS CHIP CO2 SENSOR FOR BUILDING SYSTEMS INTEGRATION (open access)

MEMS CHIP CO2 SENSOR FOR BUILDING SYSTEMS INTEGRATION

The objective of this research was to develop an affordable, reliable sensor to enable demand controlled ventilation (DCV). A significant portion of total energy consumption in the United States is used for heating or air conditioning (HVAC) buildings. To assure occupant safety and fresh air levels in large buildings, and especially those with sealed windows, HVAC systems are frequently run in excess of true requirements as automated systems cannot now tell the occupancy level of interior spaces. If such a sensor (e.g. thermostat sized device) were available, it would reduce energy use between 10 and 20% in such buildings. A quantitative measure of ''fresh air'' is the concentration of carbon dioxide (CO{sub 2}) present. An inert gas, CO{sub 2} is not easily detected by chemical sensors and is usually measured by infrared spectroscopy. Ion Optics research developed a complete infrared sensor package on a single MEMS chip. It contains the infrared (IR) source, IR detector and IR filter. The device resulting from this DOE sponsored research has sufficient sensitivity, lifetime, and drift rate to meet the specifications of commercial instrument manufacturers who are now testing the device for use in their building systems.
Date: September 14, 2005
Creator: Greenwald, Anton Carl
Object Type: Report
System: The UNT Digital Library
NABIR Assessment Element, Expanded Rapid, Comprehensive, Lipid Biomarker Analysis for Subsurface, Community Composition and Nutritional/Physiological Status as Monitors of Remediation and Detoxification Effectiveness (open access)

NABIR Assessment Element, Expanded Rapid, Comprehensive, Lipid Biomarker Analysis for Subsurface, Community Composition and Nutritional/Physiological Status as Monitors of Remediation and Detoxification Effectiveness

NABIR funding at the University of Tennessee Center for Biomarker Analysis (CBA) has led to several key contributions to the investigation of bioremediation of metals and radionuclides. This lab has played an integral part in assessing microbial communities at the field scale at the ORNL FRC (Istok et al., 2004) and two UMTRA sites (Anderson et al., 2003, Chang et al., 2001). Our work over the period of the grant has resulted in 42-peer reviewed publications, 62 presentations (14 of which were international), and one patent pending. Currently CBA has 2 papers in press. The main objectives relating to the field portion of this program were to provide comprehensive biomarker analysis for NABIR collaborators to enhance the understanding of microbial geo-bioprocesses involved in the effective immobilization of metals (We have worked with and published or currently are publishing with 10 groups of NAIBR investigators). The laboratory portion of our research centered on methods development and has led to three major innovations that could result in a systematic way of evaluating sites for potential bioremediation. The first of these is the development of an in situ sampling device (Peacock et al., 2004, Anderson et al., 2003, Istok et al., 2004) for …
Date: September 14, 2005
Creator: White, David C.
Object Type: Report
System: The UNT Digital Library
Novel Concepts Research in Geologic Storage of CO2, Phase III Progress Report: April-June 2005 (open access)

Novel Concepts Research in Geologic Storage of CO2, Phase III Progress Report: April-June 2005

None
Date: September 14, 2005
Creator: Gupta, Neeraj
Object Type: Report
System: The UNT Digital Library
Predictability and Diagnosis of Low-Frequency Climate Processes in the Pacific (open access)

Predictability and Diagnosis of Low-Frequency Climate Processes in the Pacific

please see report.
Date: September 14, 2005
Creator: Miiler, Dr. Arthur J. & Schneider, Dr. Niklas
Object Type: Report
System: The UNT Digital Library
Progress in Development of Kharkov X-Ray Generator Nestor (open access)

Progress in Development of Kharkov X-Ray Generator Nestor

The sources of the X-rays based on Compton scattering of intense Nd:YAG laser beam on electron beam circulating in a storage ring with beam energy 43-225 MeV is under construction in NSC KIPT. In the paper the progress in development and construction of Kharkov X-ray generator NESTOR is presented. The current status of the main facility system design and development are described. New scheme and main parameters of injection system are presented. The status of power supply system and control system is described. The facility is going to be in operation in the middle of 2007 and generated X-rays flux is expected to be of about 10{sup 13} phot/s.
Date: September 14, 2005
Creator: Androsov, V.; Bulyak, V.; Dovbnya, A.; Drebot, I.; Gladkikh, P.; Grevtsev, V. et al.
Object Type: Article
System: The UNT Digital Library
STRATIGRAPHY OF THE PB-1 WELL, NOPAL 1 URANIUM DEPOSIT, PENA BLANCA, CHIHUAHUA, MEXICO (open access)

STRATIGRAPHY OF THE PB-1 WELL, NOPAL 1 URANIUM DEPOSIT, PENA BLANCA, CHIHUAHUA, MEXICO

The objectives of this report are: (1) Stratigraphic study part of integrated research project examining migration of radionuclides at Pena Blanca; (2) Immediate objectives of study include: locate stratigraphic contacts in third dimension; measure rock properties (matrix permeability, porosity, mineralogy, cation exchange capacity) of cored section; determine fracture frequency and orientation; (3) Results of study serve as primary inputs to flow and transport models.
Date: September 14, 2005
Creator: Dobson, P.
Object Type: Report
System: The UNT Digital Library
Study of Rare Radiative B Decay to K*(1430) Meson Using the BABAR Detector (open access)

Study of Rare Radiative B Decay to K*(1430) Meson Using the BABAR Detector

Radiative B Meson decay through the b {yields} s{gamma} process has been one of the most sensitive probe of new physics beyond the Standard Model, because of its importance in understanding the phenomenon of CP violation, which is believed to be necessary to explain the excess of matter over anti-matter in our universe. The inclusive picture of the b {yields} s{gamma} process is well established; however, our knowledge of the exclusive final states in radiative B meson decays is rather limited. We have investigated one of them, the exclusive, radiative B decay to the charmless K*{sub 2}(1430) meson, in a sample of 88.5 x 10{sup 6} B{bar B} events with the BABAR detector at the PEP-II storage ring. We present a measurement of the branching fractions {Beta}(B{sup 0} {yields} K*{sub 2}(1430){sup 0}{gamma}) = (1.22 {+-} 0.25 {+-} 0.10) x 10{sup -5} and {Beta}(B{sup +} {yields} K*{sub 2}(1430){sup +}){gamma} = (1.45 {+-} 0.40 {+-} 0.15) x 10{sup -5}, where the first error is statistical and the second systematic. In addition, we have performed the first search for direct CP violation in this decay with the measured asymmetry in B{sup 0} {yields} K*{sub 2}(1430){sup 0}{gamma} of {Alpha}{sub CP} = -0.08 {+-} 0.15 …
Date: September 14, 2005
Creator: Guo, Qinghua
Object Type: Report
System: The UNT Digital Library
UPDATE TO THE PROBABILISTIC VOLCANIC HAZARD ANALYSIS, YUCCA MOUNTAIN, NEVADA (open access)

UPDATE TO THE PROBABILISTIC VOLCANIC HAZARD ANALYSIS, YUCCA MOUNTAIN, NEVADA

A probabilistic volcanic hazard analysis (PVHA) was conducted in 1996 for the proposed repository at Yucca Mountain, Nevada. Based on data gathered by the Yucca Mountain Project over the course of about 15 years, the analysis integrated the judgments of a panel of ten volcanic experts using methods of formal expert elicitation. PVHA resulted in a probability distribution of the annual frequency of a dike intersecting the repository, which ranges from 10E-7 to 10E-10 (mean 1.6 x 10E-8). The analysis incorporates assessments of the future locations, rates, and types of volcanic dikes that could intersect the repository, which lies about 300 m below the surface. A particular focus of the analysis is the quantification of uncertainties. Since the 1996 PVHA, additional aeromagnetic data have been collected in the Yucca Mountain region, including a high-resolution low-altitude survey. A number of anomalies have been identified within alluvial areas and modeling suggests that some of these may represent buried eruptive centers (basaltic cinder cones). A program is currently underway to drill several of the anomalies to gain information on their origin and, if basalt, their age and composition. To update the PVHA in light of the new aeromagnetic and drilling data as well …
Date: September 14, 2005
Creator: Coppersmith, K.J.
Object Type: Report
System: The UNT Digital Library