R&D ERL: Low level RF (open access)

R&D ERL: Low level RF

A superconducting RF (SRF) Energy Recovery Linac (ERL) is currently under development at the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The major components from an RF perspective are (a) a 5-cell SRF ERL cavity, (b) an SRF photocathode electron gun, and (c) a drive laser for the photocathode gun. Each of these RF subsystems has its own set of RF performance requirements, as well as common requirements for ensuring correct synchronism between them. A low level RF (LLRF) control system is currently under development, which seeks to leverage both technology and experience gained from the recently commissioned RHIC LLRF system upgrade. This note will review the LLRF system requirements and describe the system to be installed at the ERL.
Date: January 15, 2010
Creator: Smith, K.
Object Type: Report
System: The UNT Digital Library
Research and Development (R&D) to Enhance Homeland Security: CRS Experts (open access)

Research and Development (R&D) to Enhance Homeland Security: CRS Experts

This report includes a table which provides access to names and contact information for CRS experts on policy concerns relating to research and development (R&D) to enhance homeland security.
Date: January 15, 2010
Creator: Gottron, Frank
Object Type: Report
System: The UNT Digital Library
Results-Oriented Cultures: Office of Personnel Management Should Review Administrative Law Judge Program to Improve Hiring and Performance Management (open access)

Results-Oriented Cultures: Office of Personnel Management Should Review Administrative Law Judge Program to Improve Hiring and Performance Management

A letter report issued by the Government Accountability Office with an abstract that begins "The Administrative Procedure Act established unique conditions for administrative law judges' (ALJ) hiring and employment to protect their decisional independence. However, the potential for a wave of retirements and other events have focused attention on how ALJs are hired and managed. In response to the Consolidated Appropriations Act of 2008, this report examines, among other things, (1) the process for hiring ALJs and selected agencies' observations of the process; (2) ALJs' retirement eligibility and retirement issues; (3) and agency managers' reported ALJ performance management practices and stakeholders' views of these practices. To address these objectives GAO reviewed relevant statutes, regulations, Office of Personnel Management (OPM) retirement-related data, and other program-related documents, and interviewed officials from OPM, ALJ professional associations, and the two largest federal agencies employing ALJs--the Social Security Administration (SSA) and the Department of Health and Human Services (HHS)."
Date: January 15, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Rotatable magnetic anisotropy of CoO/Fe/Ag(001) in ultrathin regime of the CoO layer (open access)

Rotatable magnetic anisotropy of CoO/Fe/Ag(001) in ultrathin regime of the CoO layer

None
Date: January 15, 2010
Creator: Park, J. S.; Wu, J.; Arenholz, E.; Liberati, M.; Scholl, A.; Meng, Y. et al.
Object Type: Article
System: The UNT Digital Library
Short-term antibiotic treatment has differing long-term impacts on the human throat and gut microbiome (open access)

Short-term antibiotic treatment has differing long-term impacts on the human throat and gut microbiome

Antibiotic administration is the standard treatment for the bacterium Helicobacter pylori, the main causative agent of peptic ulcer disease and gastric cancer. However, the long-term consequences of this treatment on the human indigenous microbiota are relatively unexplored. Here we studied short- and long-term effects of clarithromycin and metronidazole treatment, a commonly used therapy regimen against H. pylori, on the indigenous microbiota in the throat and in the lower intestine. The bacterial compositions in samples collected over a four year period were monitored by analyzing the 16S rRNA gene using 454-based pyrosequencing and terminal-restriction fragment length polymorphism (T-RFLP). While the microbial communities of untreated control subjects were relatively stable over time, dramatic shifts were observed one week after antibiotic treatment with reduced bacterial diversity in all treated subjects in both locations. While the microbiota of the different subjects responded uniquely to the antibiotic treatment some general trends could be observed; such as a dramatic decline in Actinobacteria in both throat and feces immediately after treatment. Although the diversity of the microbiota subsequently recovered to resemble the pre treatment states, the microbiota remained perturbed in some cases for up to four years post treatment. In addition, four years after treatment high levels …
Date: January 15, 2010
Creator: Jakobsson, H.; Jernberg, C.; Andersson, A.F.; Sjolund-Karlsson, M.; Jansson, J.K. & Engstrand, L.
Object Type: Article
System: The UNT Digital Library
The Smart Grid: An Estimation of the Energy and CO2 Benefits (open access)

The Smart Grid: An Estimation of the Energy and CO2 Benefits

This report articulates nine mechanisms by which the smart grid can reduce energy use and carbon impacts associated with electricity generation and delivery. The quantitative estimates of potential reductions in electricity sector energy and associated CO2 emissions presented are based on a survey of published results and simple analyses. This report does not attempt to justify the cost effectiveness of the smart grid, which to date has been based primarily upon the twin pillars of cost-effective operation and improved reliability. Rather, it attempts to quantify the additional energy and CO2 emission benefits inherent in the smart grid’s potential contribution to the nation’s goal of mitigating climate change by reducing the carbon footprint of the electric power system.
Date: January 15, 2010
Creator: Pratt, Robert G.; Balducci, Patrick J.; Gerkensmeyer, Clint; Katipamula, Srinivas; Kintner-Meyer, Michael CW; Sanquist, Thomas F. et al.
Object Type: Report
System: The UNT Digital Library
Social Security: Calculation and History of Taxing Benefits (open access)

Social Security: Calculation and History of Taxing Benefits

None
Date: January 15, 2010
Creator: Scott, Christine & Mulvey, Janemarie
Object Type: Report
System: The UNT Digital Library
Spectral induced polarization signatures of abiotic FeS precipitation (open access)

Spectral induced polarization signatures of abiotic FeS precipitation

In recent years, geophysical methods have been shown to be sensitive to microbial induced mineralization processes. The spectral induced polarization (SIP) method appears to be very promising for monitoring mineralization and microbial processes. With this work, we study the links of mineralization and SIP signals, in the absence of microbial activity. We recorded the SIP response during abiotic FeS precipitation. We show that the SIP signals are diagnostic of FeS mineralization and can be differentiated from SIP signals from bio-mineralization processes. More specifically the imaginary conductivity shows almost linear dependence on the amount of FeS precipitating out of solution, above the threshold value 0.006 gr under our experimental conditions. This research has direct implications for the use of the SIP method as a monitoring, and decision making, tool for sustainable remediation of metals in contaminated soils and groundwater.
Date: January 15, 2010
Creator: Ntarlagiannis, D.; Doherty, R. & Williams, K. H.
Object Type: Article
System: The UNT Digital Library
Spin-orbit Coupling Induced Magnetism in the d-density Wave Phase of La2-xBaxCuO4 Superconductors (open access)

Spin-orbit Coupling Induced Magnetism in the d-density Wave Phase of La2-xBaxCuO4 Superconductors

We study the effects of spin-orbit coupling in the d-density wave (DDW) phase. In the low-temperature orthorhombic phase of La{sub 2-x}Ba{sub x}CuO{sub 4}, we find that spin-orbit coupling induces ferromagnetic moments in the DDW phase, which are polarized along the [110] direction with a considerable magnitude. This effect does not exist in the superconducting phase. On the other hand, if the d-density wave order does not exist at zero field, a magnetic field along the [110] direction always induces such a staggered orbital current. We discuss experimental constraints on the DDW states in light of our theoretical predictions.
Date: January 15, 2010
Creator: Wu, Congjun; /Stanford U., Phys. Dept. /Santa Barbara, KITP; Zaanen, Jan; Zhang, Shou-Cheng & /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Spin Splitting and Spin Current in Strained Bulk Semiconductors (open access)

Spin Splitting and Spin Current in Strained Bulk Semiconductors

We present a theory for two recent experiments in bulk strained semiconductors and show that a new, previously overlooked, strain spin-orbit coupling term may play a fundamental role. We propose simple experiments that could clarify the origin of strain-induced spin-orbit coupling terms in inversion asymmetric semiconductors. We predict that a uniform magnetization parallel to the electric field will be induced in the samples studied in for specific directions of the applied electric field. We also propose special geometries to detect spin currents in strained semiconductors.
Date: January 15, 2010
Creator: Bernevig, B.Andrei; Zhang, Shou-Cheng & /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
A sufficient condition for the absence of the sign problem in the fermionic quantum Monte-Carlo algorithm (open access)

A sufficient condition for the absence of the sign problem in the fermionic quantum Monte-Carlo algorithm

Quantum Monte-Carlo (QMC) simulations involving fermions have the notorious sign problem. Some well-known exceptions of the auxiliary field QMC algorithm rely on the factorizibility of the fermion determinant. Recently, a fermionic QMC algorithm has been found in which the fermion determinant may not necessarily factorizable, but can instead be expressed as a product of complex conjugate pairs of eigenvalues, thus eliminating the sign problem for a much wider class of models. In this paper, we present general conditions for the applicability of this algorithm and point out that it is deeply related to the time reversal symmetry of the fermion matrix. We apply this method to various models of strongly correlated systems at all doping levels and lattice geometries, and show that many novel phases can be simulated without the sign problem.
Date: January 15, 2010
Creator: Wu, Congjun; Zhang, Shou-Cheng & /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Texas Register, Volume 35, Number 3, Pages 299-406, January 15, 2010 (open access)

Texas Register, Volume 35, Number 3, Pages 299-406, January 15, 2010

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: January 15, 2010
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area (open access)

Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area

Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).
Date: January 15, 2010
Creator: Pruess, K. & Doughty, C.
Object Type: Article
System: The UNT Digital Library
U.S. Immigration Policy on Haitian Migrants (open access)

U.S. Immigration Policy on Haitian Migrants

This report discusses whether the balance should tip more toward humanitarian immigration policies as a consequence of the humanitarian crises that resulted from the January 12, 2010 earthquake in Haiti.
Date: January 15, 2010
Creator: Wasem, Ruth Ellen
Object Type: Report
System: The UNT Digital Library