Resource Type

144 Matching Results

Results open in a new window/tab.

Optimization of the LCLS Single Pulse Shutter (open access)

Optimization of the LCLS Single Pulse Shutter

A mechanical shutter which operates on demand is used to isolate a single pulse from a 120 Hz X-ray source. This is accomplished with a mechanical shutter which is triggered on demand with frequencies ranging from 0 to 10 Hz. The single pulse shutter is an iron blade that oscillates on a pivot in response to a force generated by a pair of pulsed electromagnets (current driven teeter-totter). To isolate an individual pulse from the X-ray beam, the motion of the mechanical shutter should be synchronized in such a way that it allows a single pulse to pass through the aperture and blocks the other incoming pulses. Two consecutive pulses are only {approx} 8 ms apart and the shutter is required to complete one full cycle such that no two pulses pass through the opening. Also the opening of the shutter blade needs to be at least 4 mm so that a 1 mm diameter rms Gaussian beam can pass through without modulation. However, the 4 mm opening is difficult to obtain due to blade rebound and oscillation of the blade after colliding with the electromagnet. The purpose of this project is to minimize and/or totally eliminate the rebound of …
Date: August 25, 2010
Creator: Adera, Solomon & /Georgia Tech., Atlanta /SLAC
System: The UNT Digital Library
Assistance to States on Electric Industry Issues (open access)

Assistance to States on Electric Industry Issues

This project seeks to educate state policymakers through a coordinated approach involving state legislatures, regulators, energy officials, and governors’ staffs. NCSL’s activities in this project focus on educating state legislators. Major components of this proposal include technical assistance to state legislatures, briefing papers, coordination with the National Council on Electricity Policy, information assistance, coordination and outreach, meetings, and a set of transmission-related activities.
Date: October 25, 2010
Creator: Andersen, Glen
System: The UNT Digital Library
The European Parliament (open access)

The European Parliament

This report discusses the construction and history of the European Parliament (EP), its role in functions of the EU as well as internationally, various international supports and criticisms of the EP, and the EP's ties with the U.S. Congress.
Date: February 25, 2010
Creator: Archick, Kristin & Mix, Derek E.
System: The UNT Digital Library
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

This report provides a summary overview of issues regarding the relationship between the United States and the EU, many of which may be of interest to the second session of the 111th Congress. The global financial crisis and recession has challenged both sides to forge a common response. The United States and EU have a number of lingering trade disputes, but have led the push to liberalize world trade, and have sought to reduce non-tariff and regulatory barriers in the transatlantic marketplace.
Date: February 25, 2010
Creator: Archick, Kristin & Mix, Derek E.
System: The UNT Digital Library
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

This report provides a brief overview of the European Union (EU), an economic and political partnership between 27 sovereign member states. The report describes the formation of the EU, the three main institutions of the EU, and the EU's relationship with the United States.
Date: August 25, 2010
Creator: Archick, Kristin & Mix, Derek E.
System: The UNT Digital Library
The Market Structure of the Health Insurance Industry (open access)

The Market Structure of the Health Insurance Industry

This report discusses whether or not the current health insurance market structure hinders the U.S. health system's ability to reach the policy goals of expanding health insurance coverage and containing health care costs. It also describes the forces that have shaped the health insurance industry, including its historical evolution, characteristics of health care and health insurance, determinants of supply and demand for health insurance, and the nature of competition among health insurers.
Date: May 25, 2010
Creator: Austin, D. Andrew & Hungerford, Thomas L.
System: The UNT Digital Library
Exploratory Experimentation and Computation (open access)

Exploratory Experimentation and Computation

We believe the mathematical research community is facing a great challenge to re-evaluate the role of proof in light of recent developments. On one hand, the growing power of current computer systems, of modern mathematical computing packages, and of the growing capacity to data-mine on the Internet, has provided marvelous resources to the research mathematician. On the other hand, the enormous complexity of many modern capstone results such as the Poincare conjecture, Fermat's last theorem, and the classification of finite simple groups has raised questions as to how we can better ensure the integrity of modern mathematics. Yet as the need and prospects for inductive mathematics blossom, the requirement to ensure the role of proof is properly founded remains undiminished.
Date: February 25, 2010
Creator: Bailey, David H. & Borwein, Jonathan M.
System: The UNT Digital Library
Data Quality Objectives Supporting Radiological Air Emissions Monitoring for the PNNL Site (open access)

Data Quality Objectives Supporting Radiological Air Emissions Monitoring for the PNNL Site

This document of Data Quality Objectives (DQOs) was prepared based on the U.S. Environmental Protection Agency (EPA) Guidance on Systematic Planning Using the Data Quality Objectives Process, EPA, QA/G4, 2/2006 (EPA 2006) as well as several other published DQOs. Pacific Northwest National Laboratory (PNNL) is in the process of developing a radiological air monitoring program for the PNNL Site that is distinct from that of the nearby Hanford Site. Radiological emissions at the PNNL Site result from Physical Sciences Facility (PSF) major emissions units. A team was established to determine how the PNNL Site would meet federal regulations and address guidelines developed to monitor and estimate offsite air emissions of radioactive materials. The result is a program that monitors the impact to the public from the PNNL Site.
Date: May 25, 2010
Creator: Barnett, J. M.; Meier, Kirsten M.; Snyder, Sandra F.; Fritz, Brad G.; Poston, Ted M. & Rhoads, Kathleen
System: The UNT Digital Library
Characterization of High Level Waste from a Hybrid LIFE Engine for Enhanced Repository Performance (open access)

Characterization of High Level Waste from a Hybrid LIFE Engine for Enhanced Repository Performance

None
Date: August 25, 2010
Creator: Beckett, E. & Fratoni, M.
System: The UNT Digital Library
Thermometric- and Acoustic-Based Beam Power Monitor for Ultra-Bright X-Rays (open access)

Thermometric- and Acoustic-Based Beam Power Monitor for Ultra-Bright X-Rays

A design for an average beam power monitor for ultra-bright X-ray sources is proposed that makes simultaneous use of calorimetry and radiation acoustics. Radiation incident on a solid target will induce heating and ultrasonic vibrations, both of which may be measured to give a fairly precise value of the beam power. The monitor is intended for measuring ultra-bright Free-Electron Laser (FEL) X-ray beams, for which traditional monitoring technologies such as photo-diodes or scintillators are unsuitable. The monitor consists of a Boron Carbide (B{sub 4}C) target designed to absorb most of the incident beam's energy. Resistance temperature detectors (RTD) and piezoelectric actuators are mounted on the outward faces of the target to measure the temperature changes and ultrasonic vibrations induced by the incident beam. The design was tested using an optical pulsed beam (780 nm, 120 and 360 Hz) from a Ti:sapphire oscillator at several energies between 0.8 and 2.6 mJ. The RTDs measured an increase in temperature of about 10 K over a period of several minutes. The piezoelectric sensors recorded ringing acoustic oscillations at 580 {+-} 40 kHz. Most importantly, the amplitude of the acoustic signals was observed to scale linearly with beam power up to 2 mJ of …
Date: August 25, 2010
Creator: Bentsen, Gregory & /SLAC, /Rochester U.
System: The UNT Digital Library
Physical Properties of Hanford Transuranic Waste (open access)

Physical Properties of Hanford Transuranic Waste

The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.
Date: March 25, 2010
Creator: Berg, John C.
System: The UNT Digital Library
Dark Energy Camera for Blanco (open access)

Dark Energy Camera for Blanco

In order to make accurate measurements of dark energy, a system is needed to monitor the focus and alignment of the Dark Energy Camera (DECam) to be located on the Blanco 4m Telescope for the upcoming Dark Energy Survey. One new approach under development is to fit out-of-focus star images to a point spread function from which information about the focus and tilt of the camera can be obtained. As a first test of a new algorithm using this idea, simulated star images produced from a model of DECam in the optics software Zemax were fitted. Then, real images from the Mosaic II imager currently installed on the Blanco telescope were used to investigate the algorithm's capabilities. A number of problems with the algorithm were found, and more work is needed to understand its limitations and improve its capabilities so it can reliably predict camera alignment and focus.
Date: August 25, 2010
Creator: Binder, Gary A. & /SLAC, /Caltech
System: The UNT Digital Library
A New United Nations Entity for Women: Issues for Congress (open access)

A New United Nations Entity for Women: Issues for Congress

In September 2009, U.N. member states, including the United States, adopted a General Assembly resolution expressing strong support for the consolidation of four U.N. bodies addressing women's issues into one composite entity. This report discusses possible policy issues that may arise as the composite gender entity is established, including its funding mechanisms, the creation of an effective governance structure, the entity's possible impact on U.N. system in-country operational capacity, and the relationships and coordination between the entity and other U.N. system bodies. The report also discusses the entity in the context of broader U.N. reform efforts and examines the involvement of nongovernmental organizations (NGOs). Finally, it analyzes U.S. policy toward the new entity, including its possible role in U.S. foreign policy and the level and extent of U.S. financial contributions to existing U.N. system gender entities.
Date: May 25, 2010
Creator: Blanchfield, Luisa
System: The UNT Digital Library
War in Afghanistan: Strategy, Military Operations, and Issues for Congress (open access)

War in Afghanistan: Strategy, Military Operations, and Issues for Congress

The character of the war in Afghanistan evolved from a violent struggle against al Qaeda and its Taliban supporters to a multi-faceted counterinsurgency (COIN) effort. This report provides an examination of the war's background, context, and early execution; an analytical discussion of the COIN war to date, including strategy, organization, participation, and key facets of the effort including population security, advising the Afghan National Security Forces (ANSF), counter-narcotics, reconciliation, community outreach, and civil-military coordination; and an analysis of major strategic and operational issues and options that the 111th Congress may opt to consider.
Date: February 25, 2010
Creator: Bowman, Steve & Dale, Catherine
System: The UNT Digital Library
Legislative Branch Revolving Funds (open access)

Legislative Branch Revolving Funds

Legislative branch revolving funds support the "business-type activities" of the House, Senate, and legislative branch agencies. This report traces the establishment, use, and recent development of these funds. Where available, the current status of funds is provided, using standard federal government budget object classifications.
Date: August 25, 2010
Creator: Brudnick, Ida A. & Straus, Jacob R.
System: The UNT Digital Library
The Endangered Species Act (ESA) in the 111th Congress: Conflicting Values and Difficult Choices (open access)

The Endangered Species Act (ESA) in the 111th Congress: Conflicting Values and Difficult Choices

None
Date: February 25, 2010
Creator: Buck, Eugene H.; Corn, M. Lynne; Sheikh, Pervaze A.; Meltz, Robert & Alexander, Kristina
System: The UNT Digital Library
Asian Carp and the Great Lakes Region (open access)

Asian Carp and the Great Lakes Region

Four species of non-indigenous Asian carp are expanding their range in U.S. waterways, resulting in a variety of concerns and problems. Three species—bighead, silver, and black carp—are of particular note, based on the perceived degree of environmental concern. This report examines current controversy relating to what measures might be necessary and sufficient to prevent movement of Asian carp from the Mississippi River drainage into the Great Lakes through the Chicago Area Waterway System. Movement of Asian carp into the Great Lakes is ultimately of concern because increased numbers of carp in the Great Lakes increases the risk that Asian carp will establish reproducing populations in these waters. Bills have been introduced in the 111th Congress to direct actions to avoid the possibility of carp becoming established in the Great Lakes.
Date: May 25, 2010
Creator: Buck, Eugene H.; Upton, Harold F.; Stern, Charles V. & Nichols, James E.
System: The UNT Digital Library
Asian Carp and the Great Lakes Region (open access)

Asian Carp and the Great Lakes Region

Report describing threats to waterways in the Great Lakes area by invasive carp species. It includes background about the various species, the potential negative impacts and federal responses, as well as litigation, international concerns (regarding Canada), and areas of interest for Congress.
Date: June 25, 2010
Creator: Buck, Eugene H.; Upton, Harold F.; Stern, Charles V. & Nichols, James E.
System: The UNT Digital Library
"Don't Ask, Don't Tell:" The Law and Military Policy on Same-Sex Behavior (open access)

"Don't Ask, Don't Tell:" The Law and Military Policy on Same-Sex Behavior

This report describes the "Don't Ask, Don't Tell" military policy. Under this policy, but not the law, service members are not to be asked about nor allowed to discuss their "same-sex orientation." This report also describes recent efforts by certain Members of Congress to amending this policy.
Date: March 25, 2010
Creator: Burrelli, David F.
System: The UNT Digital Library
Executive Orders: Issuance and Revocation (open access)

Executive Orders: Issuance and Revocation

This report reviews the "definition" of an executive order and how it is distinguishable from other written instruments, and then provides an overview of the President's constitutional authority to issue such directives. It also discusses the legal framework relied on by the courts to analyze the validity of presidential actions, and the roles of the President and Congress in modifying and revoking executive orders.
Date: March 25, 2010
Creator: Burrows, Vanessa K.
System: The UNT Digital Library
Supreme Court Nominee Elena Kagan: Administrative Law and the Nondelegation Doctrine (open access)

Supreme Court Nominee Elena Kagan: Administrative Law and the Nondelegation Doctrine

None
Date: June 25, 2010
Creator: Burrows, Vanessa K.
System: The UNT Digital Library
Health Reform and the 111th Congress (open access)

Health Reform and the 111th Congress

This report presents basic background information on health insurance that may be useful to legislators considering health insurance reforms. It describes health insurance reform approaches and provides brief descriptions of health insurance reform bills introduced in the 111th Congress.
Date: February 25, 2010
Creator: Chaikind, Hinda
System: The UNT Digital Library
Afghanistan Casualties: Military Forces and Civilians (open access)

Afghanistan Casualties: Military Forces and Civilians

This report collects statistics from a variety of sources on casualties sustained during Operation Enduring Freedom (OEF), which began on October 7, 2001. OEF actions took place primarily in Afghanistan; however, OEF casualties also includes American casualties in Pakistan, Uzbekistan, Guantanamo Bay (Cuba), Djibouti, Eritrea, Ethiopia, Jordan, Kenya, Kyrgyzstan, the Philippines, Seychelles, Sudan, Tajikistan, Turkey, and Yemen.
Date: March 25, 2010
Creator: Chesser, Susan G.
System: The UNT Digital Library
The Uniformed and Overseas Citizens Absentee Voting Act: Overview and Issues (open access)

The Uniformed and Overseas Citizens Absentee Voting Act: Overview and Issues

This report discusses the Uniformed and Overseas Citizens Absentee Voting Act (UOCAVA) of 1986, which was enacted to improve absentee registration and voting for this group of voters and to consolidate existing laws.
Date: May 25, 2010
Creator: Coleman, Kevin J.
System: The UNT Digital Library