Potential of pyroprocessing for partitioning purex wastes (open access)

Potential of pyroprocessing for partitioning purex wastes

The processes are extremely compact. The process reagents are highly resistant to radiation damage and, therefore, can be used to handle short-cooled, highly concentrated waste with negligible degradation. Most reagents can be recycled back through the process many times, thereby minimizing the generation of waste products, and also reducing the process cost. Fission-product wastes are discharged from the process as concentrated, solid wastes, typically in a metal matrix suitable for permanent disposal. Long cooling periods are not needed prior to conversion to a suitable waste form. The recovered actinides are obtained as metals and cen be easily stored or shipped. Pyrochemical processing of nuclear fuels should be considered as a second generation technology.
Date: July 23, 1980
Creator: Coops, M. S. & Sisson, D. H.
System: The UNT Digital Library
Developments in solid state detectors for personnel neutron dosimetry (open access)

Developments in solid state detectors for personnel neutron dosimetry

The personnel neutron exposure potential at the Lawrence Livermore National Laboratory is more diverse than at many other facilities, due to the wide range of neutron producing activities. Albedo energy response problems in the face of the diversity of sources, and a concern about possible photon interferences with the neutron albedo response, have prompted development of some additional dosimetry techniques to augment the personnel monitoring program. This work now consists of two programs - the dosimeter/spectrometer (DOSPEC) in which track etch detectors are added to the albedo badge to provide some energy evaluation and gamma insensitivity, and development of solid state thin film MOS detectors to provide a real time, gamma insensitive dosimeter.
Date: July 23, 1981
Creator: Griffith, R.V.; Davidson, K.J.; Miller, D.E. & Vindelov, K.E.
System: The UNT Digital Library
Digital Frequency Domain Multiplexer for mm-Wavelength Telescopes (open access)

Digital Frequency Domain Multiplexer for mm-Wavelength Telescopes

An FPGA based digital signal processing (DSP) system for biasing and reading out multiplexed bolometric detectors for mm-wavelength telescopes is presented. This readout system is being deployed for balloon-borne and ground based cosmology experiments with the primary goal of measuring the signature of inflation with the Cosmic Microwave Background Radiation. The system consists of analog superconducting electronics running at 250 mK and 4 K, coupled to digital room temperature backend electronics described here. The digital electronics perform the real time functionality with DSP algorithms implemented in firmware. A soft embedded processor provides all of the slow housekeeping control and communications. Each board in the system synthesizes multi-frequency combs of 8 to 32 carriers in the MHz band to bias the detectors. After the carriers have been modulated with the sky-signal by the detectors, the same boards digitize the comb directly. The carriers are mixed down to base-band and low pass filtered. The signal bandwidth of 0.050Hz-100 Hz places extreme requirements on stability and requires powerful filtering techniques to recover the sky-signal from the MHz carriers.
Date: July 23, 2007
Creator: Spieler, Helmuth G; Dobbs, Matt; Bissonnette, Eric & Spieler, Helmuth G.
System: The UNT Digital Library
Exact de Rham Sequences of Spaces Defined on Macro-elements in Two and Three Spatial Dimensions (open access)

Exact de Rham Sequences of Spaces Defined on Macro-elements in Two and Three Spatial Dimensions

This paper proposes new finite element spaces that can be constructed for agglomerates of standard elements that have certain regular structure. The main requirement is that the agglomerates share faces that have closed boundaries composed of 1-d edges. The spaces resulting from the agglomerated elements are subspaces of the original de Rham sequence of H{sup 1}-conforming, H(curl) conforming, H(div) conforming and piecewise constant spaces associated with an unstructured 'fine' mesh. The procedure can be recursively applied so that a sequence of nested de Rham complexes can be constructed. As an illustration we generate coarser spaces from the sequence corresponding to the lowest order Nedelec spaces, lowest order Raviart-Thomas spaces, and for piecewise linear H{sup 1}-conforming spaces, all in three-dimensions. The resulting V-cycle multigrid methods used in preconditioned conjugate gradient iterations appear to perform similar to those of the geometrically refined case.
Date: July 23, 2007
Creator: Pasciak, J. & Vassilevski, P.
System: The UNT Digital Library
Enhancing Scalability of Sparse Direct Methods (open access)

Enhancing Scalability of Sparse Direct Methods

TOPS is providing high-performance, scalable sparse direct solvers, which have had significant impacts on the SciDAC applications, including fusion simulation (CEMM), accelerator modeling (COMPASS), as well as many other mission-critical applications in DOE and elsewhere. Our recent developments have been focusing on new techniques to overcome scalability bottleneck of direct methods, in both time and memory. These include parallelizing symbolic analysis phase and developing linear-complexity sparse factorization methods. The new techniques will make sparse direct methods more widely usable in large 3D simulations on highly-parallel petascale computers.
Date: July 23, 2007
Creator: Li, Xiaoye S.; Demmel, James; Grigori, Laura; Gu, Ming; Xia,Jianlin; Jardin, Steve et al.
System: The UNT Digital Library
Comparing Computer Run Time of Building Simulation Programs (open access)

Comparing Computer Run Time of Building Simulation Programs

This paper presents an approach to comparing computer run time of building simulation programs. The computing run time of a simulation program depends on several key factors, including the calculation algorithm and modeling capabilities of the program, the run period, the simulation time step, the complexity of the energy models, the run control settings, and the software and hardware configurations of the computer that is used to make the simulation runs. To demonstrate the approach, simulation runs are performed for several representative DOE-2.1E and EnergyPlus energy models. The computer run time of these energy models are then compared and analyzed.
Date: July 23, 2008
Creator: Hong, Tianzhen; Buhl, Fred; Haves, Philip; Selkowitz, Stephen & Wetter, Michael
System: The UNT Digital Library
ATLAS TrackingEvent Data Model -- 12.0.0 (open access)

ATLAS TrackingEvent Data Model -- 12.0.0

In this report the event data model (EDM) relevant for tracking in the ATLAS experiment is presented. The core component of the tracking EDM is a common track object which is suited to describe tracks in the innermost tracking sub-detectors and in the muon detectors in offline as well as online reconstruction. The design of the EDM was driven by a demand for modularity and extensibility while taking into account the different requirements of the clients. The structure of the track object and the representation of the tracking-relevant information are described in detail.
Date: July 23, 2006
Creator: ATLAS; Akesson, F.; Atkinson, T.; Costa, M.J.; Elsing, M.; Fleischmann, S. et al.
System: The UNT Digital Library
Ovarian carcinomas with genetic and epigenetic BRCA1 loss havedistinct molecular abnormalities (open access)

Ovarian carcinomas with genetic and epigenetic BRCA1 loss havedistinct molecular abnormalities

Subclassification of ovarian carcinomas can be used to guide treatment and determine prognosis. Germline and somatic mutations, loss of heterozygosity (LOH), and epigenetic events such as promoter hypermethylation can lead to decreased expression of BRCA1/2 in ovarian cancers. The mechanism of BRCA1/2 loss is a potential method of subclassifying high grade serous carcinomas. A consecutive series of 49 ovarian cancers was assessed for mutations status of BRCA1 and BRCA2, LOH at the BRCA1 and BRCA2 loci, methylation of the BRCA1 promoter, BRCA1, BRCA2, PTEN, and PIK3CA transcript levels, PIK3CA gene copy number, and BRCA1, p21, p53, and WT-1 immunohistochemistry. Eighteen (37%) of the ovarian carcinomas had germline or somatic BRCA1 mutations, or epigenetic loss of BRCA1. All of these tumors were high-grade serous or undifferentiated type. None of the endometrioid (n = 5), clear cell (n = 4), or low grade serous (n = 2) carcinomas showed loss of BRCA1, whereas 47% of the 38 high-grade serous or undifferentiated carcinomas had loss of BRCA1. It was possible to distinguish high grade serous carcinomas with BRCA1 mutations from those with epigenetic BRCA1 loss: tumors with BRCA1 mutations typically had decreased PTEN mRNA levels while those with epigenetic loss of BRCA1 had …
Date: July 23, 2007
Creator: Press, Joshua Z.; De Luca, Alessandro; Boyd, Niki; Young, Sean; Troussard, Armelle; Ridge, Yolanda et al.
System: The UNT Digital Library
Fast Neutron Radioactivity and Damage Studies on Materials (open access)

Fast Neutron Radioactivity and Damage Studies on Materials

None
Date: July 23, 2007
Creator: Anderson, S.; Spencer, J.; Wolf, Z.; Gallagher, G.; Pellett, D.; Boussoufi, M. et al.
System: The UNT Digital Library
Shock anomaly and s-d transition in high-pressure lanthanum (open access)

Shock anomaly and s-d transition in high-pressure lanthanum

Linear-muffin-tin orbital calculations of the band structure and pressure-volume isotherms for fcc La, both at zero and finite temperatures. The calculated bulk modulus shows a rapid stiffening in the range from 40 to 50% compression, due to termination of the 6s to 5d electronic transition. When combined with a simple Slater model analysis, these results yield a temperature dependent peak in the lattice Grueneisen parameter. Experimental confirmation of this peak is found in an anomalous stiffening seen in the shock compression data for La, and it may also have some bearing on the observed saturation of the superconducting transition temperature in La around 200 kbar.
Date: July 23, 1981
Creator: McMahan, A.K.; Skriver, H.L. & Johansson, B.
System: The UNT Digital Library
DSP accelerator for the wavelet compression/decompression of high- resolution images (open access)

DSP accelerator for the wavelet compression/decompression of high- resolution images

A Texas Instruments (TI) TMS320C30-based S-Bus digital signal processing (DSP) module was used to accelerate a wavelet-based compression and decompression algorithm applied to high-resolution fingerprint images. The law enforcement community, together with the National Institute of Standards and Technology (NISI), is adopting a standard based on the wavelet transform for the compression, transmission, and decompression of scanned fingerprint images. A two-dimensional wavelet transform of the input image is computed. Then spatial/frequency regions are automatically analyzed for information content and quantized for subsequent Huffman encoding. Compression ratios range from 10:1 to 30:1 while maintaining the level of image quality necessary for identification. Several prototype systems were developed using SUN SPARCstation 2 with a 1280 {times} 1024 8-bit display, 64-Mbyte random access memory (RAM), Tiber distributed data interface (FDDI), and Spirit-30 S-Bus DSP-accelerators from Sonitech. The final implementation of the DSP-accelerated algorithm performed the compression or decompression operation in 3.5 s per print. Further increases in system throughput were obtained by adding several DSP accelerators operating in parallel.
Date: July 23, 1993
Creator: Hunt, M. A.; Gleason, S. S. & Jatko, W. B.
System: The UNT Digital Library
Functional One-Dimensional Lipid Bilayers on Carbon Nanotube Templates (open access)

Functional One-Dimensional Lipid Bilayers on Carbon Nanotube Templates

We present one-dimensional (1-D) lipid bilayer structures that integrate carbon nanotubes with a key biological environment-phospholipid membrane. Our structures consist of lipid bilayers wrapped around carbon nanotubes modified with a hydrophilic polymer cushion layer. Despite high bilayer curvature, the lipid membrane maintains its fluidity and can sustain repeated damage-recovery cycles. We also present the first evidence of spontaneous insertion of pore-forming proteins into 1-D lipid bilayers. These structures could lead to the development of new classes of biosensors and bioelectronic devices.
Date: July 23, 2004
Creator: Artyukhin, Alexander; Shestakov, Alexei; Harper, Jennifer; Bakajin, Olgica; Stroeve, Pieter & Noy, Aleksandr
System: The UNT Digital Library
Multiple Oscillation Stabilizing Control (open access)

Multiple Oscillation Stabilizing Control

This paper presents a strategy that may be used to guide stabilizing control design for multiple oscillations, which are difficult to control using conventional control design procedures. A multiple oscillation phenomena is observed in an example power system. A local bifurcation and an interarea bifurcation develop in an example power system due to multiple bifurcation parameter variations. The dynamic behaviors of the bifurcating system are complex due to the overlapping of the two different bifurcation subsystems and are shown to be difficult to control. The double bifurcations are studied in this paper and in order to stabilize them, three kind of {mu}-synthesis robust controls are designed, (a) {mu}-synthesis power system stabilizer (MPSS); (b) {mu}-synthesis SVC control (MSVC); and (c) a mixed MPSS/MSVC control. Based on the bifurcation subsystem analysis, the measurement signals and locations of the controls are selected. The control performances of three kind of controls are evaluated and compared. The conclusions are given according to the analysis and time simulation results.
Date: July 23, 2004
Creator: Yue, M.; Schlueter, R.; Azarm, M. & Bari, R.
System: The UNT Digital Library
Operational Experience with the Frontier System in CMS (open access)

Operational Experience with the Frontier System in CMS

None
Date: July 23, 2012
Creator: Blumenfeld, Barry; Dykstra, Dave; Kreuzer, Peter; Du, Ran & Wang, Weizhen
System: The UNT Digital Library
The LCLS Timing Event System (open access)

The LCLS Timing Event System

The Linac Coherent Light Source requires precision timing trigger signals for various accelerator diagnostics and controls at SLAC-NAL. A new timing system has been developed that meets these requirements. This system is based on COTS hardware with a mixture of custom-designed units. An added challenge has been the requirement that the LCLS Timing System must co-exist and 'know' about the existing SLC Timing System. This paper describes the architecture, construction and performance of the LCLS timing event system.
Date: July 23, 2012
Creator: Dusatko, John; Allison, S.; Browne, M. & Krejcik, P.
System: The UNT Digital Library
The LCLS Undulator Beam Loss Monitor Readout System (open access)

The LCLS Undulator Beam Loss Monitor Readout System

The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.
Date: July 23, 2012
Creator: Dusatko, John; Browne, M.; Fisher, A. S.; Kotturi, D.; Norum, S. & Olsen, J.
System: The UNT Digital Library
Multi-Level Bitmap Indexes for Flash Memory Storage (open access)

Multi-Level Bitmap Indexes for Flash Memory Storage

Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data at the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.
Date: July 23, 2010
Creator: Wu, Kesheng; Madduri, Kamesh & Canon, Shane
System: The UNT Digital Library
Search for a light Higgs decaying to two gluons or ssbar in the radiative decays of Upsilon( 1S ) (open access)

Search for a light Higgs decaying to two gluons or ssbar in the radiative decays of Upsilon( 1S )

None
Date: July 23, 2013
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Grauges, E.; /Barcelona U., ECM et al.
System: The UNT Digital Library
Application of PILATUS II Detector Modules for High Resolution X-Ray Imaging Crystal Spectrometers on the Alcator C-Mod Tokamak (open access)

Application of PILATUS II Detector Modules for High Resolution X-Ray Imaging Crystal Spectrometers on the Alcator C-Mod Tokamak

A new type of X-ray imaging crystal spectrometer for Doppler measurements of the radial profiles of the ion temperature and plasma rotation velocity in tokamak plasmas is presently being developed in a collaboration between various laboratories. The spectrometer will consist of a spherically bent crystal and a two-dimensional position sensitive detector; and it will record temporally and spatially resolved X-ray line spectra from highly-charged ions. The detector must satisfy challenging requirements with respect to count rate and spatial resolution. The paper presents the results from a recent test of a PILATUS II detector module on Alcator C-Mod, which demonstrate that the PILATUS II detector modules will satisfy these requirements.
Date: July 23, 2007
Creator: M.L. Bitter, Ch. Borennimann, E.F. Eikenberry, K.W. Hill, A. Ince-Chushman, S.G. Lee, J.E. Rice, and S. Scott.
System: The UNT Digital Library
A Heterobimetallic Complex With an Unsupported Uranium(III)-Aluminum(I) Bond: (CpSiMe3)3U-AlCp* (Cp* = C5Me5) (open access)

A Heterobimetallic Complex With an Unsupported Uranium(III)-Aluminum(I) Bond: (CpSiMe3)3U-AlCp* (Cp* = C5Me5)

The discovery of molecular metal-metal bonds has been of fundamental importance to the understanding of chemical bonding. For the actinides, examples of unsupported metal-metal bonds are relatively uncommon, consisting of Cp{sub 3}U-SnPh{sub 3}, and several actinide-transition metal complexes. Traditionally, bonding in the f-elements has been described as electrostatic; however, elucidating the degree of covalency is a subject of recent research. In carbon monoxide complexes of the trivalent uranium metallocenes, decreased {nu}{sub CO} values relative to free CO suggest that the U(III) atom acts as a {pi}-donor. Ephritikhine and coworkers have demonstrated that {pi}-accepting ligands can differentiate trivalent lanthanide and actinide ions, an effect that renders this chemistry of interest in the context of nuclear waste separation technology.
Date: July 23, 2008
Creator: Minasian, Stefan; Krinsky Ph.D., Jamin; Williams, Valerie & Arnold Ph.D., John
System: The UNT Digital Library
2010 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 18-23, 2010 (open access)

2010 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 18-23, 2010

The 2010 Gordon Research Conference on Microbial Stress Responses provides an open and exciting forum for the exchange of scientific discoveries on the remarkable mechanisms used by microbes to survive in nearly every niche on the planet. Understanding these stress responses is critical for our ability to control microbial survival, whether in the context of biotechnology, ecology, or pathogenesis. From its inception in 1994, this conference has traditionally employed a very broad definition of stress in microbial systems. Sessions will cover the major steps of stress responses from signal sensing to transcriptional regulation to the effectors that mediate responses. A wide range of stresses will be represented. Some examples include (but are not limited to) oxidative stress, protein quality control, antibiotic-induced stress and survival, envelope stress, DNA damage, and nutritional stress. The 2010 meeting will also focus on the role of stress responses in microbial communities, applied and environmental microbiology, and microbial development. This conference brings together researchers from both the biological and physical sciences investigating stress responses in medically- and environmentally relevant microbes, as well as model organisms, using cutting-edge techniques. Computational, systems-level, and biophysical approaches to exploring stress responsive circuits will be integrated throughout the sessions alongside the …
Date: July 23, 2011
Creator: Ades, Sarah
System: The UNT Digital Library
LATTICE QCD AT FINITE DENSITY. (open access)

LATTICE QCD AT FINITE DENSITY.

I discuss different approaches to finite density lattice QCD. In particular, I focus on the structure of the phase diagram and discuss attempts to determine the location of the critical end-point. Recent results on the transition line as function of the chemical potential (T{sub c}({mu}{sub q})) are reviewed. Along the transition line, hadronic fluctuations have been calculated; which can be used to characterize properties of the Quark Gluon plasma and eventually can also help to identify the location of the critical end-point in the QCD phase diagram on the lattice and in heavy ion experiments. Furthermore, I comment on the structure of the phase diagram at large {mu}{sub q}.
Date: July 23, 2006
Creator: SCHMIDT, C.
System: The UNT Digital Library
Wide-field surveys from the SNAP mission (open access)

Wide-field surveys from the SNAP mission

The Supernova/Acceleration Probe (SNAP) is a proposed space-borne observatory that will survey the sky with a wide-field optical/NIR imager. The images produced by SNAP will have an unprecedented combination of depth, solid-angle, angular resolution, and temporal sampling. Two 7.5 square-degree fields will be observed every four days over 16 months to a magnitude depth of AB = 27.7 in each of nine filters. Co-adding images over all epochs will give an AB = 30.3 per filter. A 300 square-degree field will be surveyed with no repeat visits to AB = 28 per filter. The nine filters span 3500-17000 {angstrom}. Although the survey strategy is tailored for supernova and weak gravitational lensing observations, the resulting data supports a broad range of auxiliary science programs.
Date: July 23, 2002
Creator: agkim@lbl.gov
System: The UNT Digital Library
ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES) (open access)

ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES)

The International Organization for Standardization (ISO) has published a Guide to the expression of Uncertainty in Measurement (GUM). The IUPAC Commission on Isotopic Abundance and Atomic Weight (CIAAW) began attaching uncertainty limits to their recommended values about forty years ago. CIAAW's method for determining and assigning uncertainties has evolved over time. We trace this evolution to their present method and their effort to incorporate the basic ISO/GUM procedures into evaluations of these uncertainties. We discuss some dilemma the CIAAW faces in their present method and whether it is consistent with the application of the ISO/GUM rules. We discuss the attempt to incorporate variations in measured isotope ratios, due to natural fractionation, into the ISO/GUM system. We make some observations about the inconsistent treatment in the incorporation of natural variations into recommended data and uncertainties. A recommendation for expressing atomic weight values using a tabulated range of values for various chemical elements is discussed.
Date: July 23, 2007
Creator: Holden, N. E.
System: The UNT Digital Library