3-D Silicon Photonic Lattices- Cornerstone of an Emerging Photonics Revolution (open access)

3-D Silicon Photonic Lattices- Cornerstone of an Emerging Photonics Revolution

Three-dimensional photonic lattices are engineered materials which are the photonic analogues of semiconductors. These structures were first proposed and demonstrated in the mid-to-late 1980's. However, due to fabrication difficulties, lattices active in the infrared are only just emerging. Wide ranges of structures and fabrication approaches have been investigated. The most promising approach for many potential applications is a diamond-like structure fabricated using silicon microprocessing techniques. This approach has enabled the fabrication of 3-D silicon photonic lattices active in the infrared. The structures display band gaps centered from 12{micro} down to 1.55{micro}.
Date: July 8, 1999
Creator: Fleming, J.G. & Lin, Shawn-Yu
Object Type: Article
System: The UNT Digital Library
Air Force Logistics: C-17 Support Plan Does Not Adequately Address Key Issues (open access)

Air Force Logistics: C-17 Support Plan Does Not Adequately Address Key Issues

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO reviewed the Air Force's C-17 logistics support plan, focusing on the: (1) C-17's core logistics capabilities; (2) cost effectiveness of the planned support strategy; and (3) Air Force's implementation of the plan under current law."
Date: July 8, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Air Kerma Calibration Factors and kch Values for PTW Soft X-ray, NACP and Roos Ionization Chambers at Very Low X-ray Energies (0.035 mm - 1.0 mm Al HVL) (open access)

Air Kerma Calibration Factors and kch Values for PTW Soft X-ray, NACP and Roos Ionization Chambers at Very Low X-ray Energies (0.035 mm - 1.0 mm Al HVL)

Several national and international protocols have been established for the dosimetry of x-ray beams used in radiotherapy. For the very low energy x-rays (0.035mm-1.0 mm Al HVL) only two codes are available: the UK IPEMB Code of Practice and the German standard, DIN 6809 Part 4. The measurement of very low energy x-ray beams is normally performed with parallel plate ionization chambers calibrated at a standards laboratory and characterized by an air kerma calibration factor N{sub k}. According to the IPEMB Code of Practice the absorbed dose in the user's beam should be determined by taking measurements with the parallel plate chamber positioned such that its entrance window is at the surface of a full-scatter water equivalent phantom. The absorbed dose to water can then be determined using an equation which includes a factor, k{sub ch}, which accounts for the change in response of the ionization chamber between the calibration in air and measurement at the surface of the phantom. N{sub k} and k{sub ch} values for the PTW soft X-ray, NACP and Roos ionization chambers are reported. It was found that k{sub ch} values varied from about 1.01 to 1.08 depending on the chamber, beam quality and phantom material. …
Date: July 8, 1999
Creator: Ipe, Nisy E.
Object Type: Report
System: The UNT Digital Library
Application of the Two-Parameter J-A2 Description to Ductile Crack Growth (open access)

Application of the Two-Parameter J-A2 Description to Ductile Crack Growth

Typical ASTM fracture testing determines J-integral resistance (J-R) curve or fracture toughness (JIC) based on specimens with high constraint geometry such as those specified in ASTM E1737-96. A three-term asymptotic solution with two parameters J and A2 (a constraint parameter) has been developed for characterizing the constraint effect of various geometries. The present paper extends the J-A2 characterization of a stationary crack tip to the regime of stable crack growth. Similar to the concept of J-controlled crack growth, the J-A2 description can be approximately used to characterize ductile crack growth under certain amount of crack extension. The region of J-A2 controlled crack growth is much larger than that controlled by J-integral alone. From the relationships between A2 and the test data, JIC and tearing modulus (TR), the coefficients used to define a J-R curve can be determined. For non-standard specimens or actual structures, once the constraint parameter A2 is determined, the J-R curves appropriate for these geometries can then be obtained. A procedure of transferring J-R curves determined from the standard ASTM procedure to non-standard specimens or flawed structures is outlined in the paper.
Date: July 8, 1999
Creator: Lam, P.S.
Object Type: Article
System: The UNT Digital Library
B Decays as a probe of spontaneous cp-violation in SUSY models (open access)

B Decays as a probe of spontaneous cp-violation in SUSY models

We consider phenomenological implications of susy models with spontaneously broken CP-symmetry. In particular, we analyze CP-asymmetries in B decays and find that the predictions of these models are vastly different from those of the SM. These features are common to NMSSM-like models with an arbitrary number of sterile superfields and the MSSM with broken R-parity.
Date: July 8, 1999
Creator: Lebedev, Oleg
Object Type: Article
System: The UNT Digital Library
CAT Guide and Beamline Directory. A key to APS Collaborative Access Teams (open access)

CAT Guide and Beamline Directory. A key to APS Collaborative Access Teams

The Advanced Photon Source (APS), a national user facility for synchrotrons radiation research, is located at Argonne National Laboratory, approximately 25 miles southwest of Chicago, Illinois. The APS is considered a third-generation synchrotrons radiation facility (specifically designed to accommodate insertion devices to serve as radiation sources) and is one of three such facilities in the world. Currently, it is the most brilliant source in the United States for research in such diverse fields as biology, medicine, materials science, chemistry, geology, agriculture and soil science, physics, and manufacturing technology. Researchers use the APS either as members of Collaborative Access Teams (CATS) or as Independent Investigators (IIs). CATS are responsible for designing, building, and operating beamlines in one or more sectors, each sector consisting of an insertion-device (ID) beamline and a bending-magnet (BM) beamline. Each beamline is designed to accommodate a specific type of research program(s) and is optimized accordingly. CAT members are entitled to use 75% of the available beam time to pursue CAT research goals. The remaining 25% of the available beam time must be made available to IIs. This document was written to help prospective IIs determine which beamlines are suitable for their specific experiments.
Date: July 8, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Choosing wind power plant locations and sizes based on electric reliability measures using multiple-year wind speed measurements (open access)

Choosing wind power plant locations and sizes based on electric reliability measures using multiple-year wind speed measurements

To project the US potential to meet future electricity demands with wind energy, estimates of available wind resource and costs to access that resource are critical. The US Department of Energy (DOE) Energy Information Administration (EIA) annually estimates the US market penetration of wind in its Annual Energy Outlook series. For these estimates, the EIA uses wind resource data developed by the Pacific Northwest National Laboratory for each region of the country. However, the EIA multiplies the cost of windpower by several factors, some as large as 3, to account for resource quality, market factors associated with accessing the resource, electric grid impacts, and rapid growth in the wind industry. This paper examines the rationale behind these additional costs and suggests alternatives.
Date: July 8, 1999
Creator: Milligan, M.R. & Artig, R.
Object Type: Article
System: The UNT Digital Library
CROSS DRIFT ALCOVE/NICHE UTILITIES ANALYSIS (open access)

CROSS DRIFT ALCOVE/NICHE UTILITIES ANALYSIS

The purpose of this analysis is to provide the design basis and general arrangement requirements of the non-potable water, waste water, compressed air and ventilation (post excavation) utilities required in support of the Cross Drift alcoves and niches.
Date: July 8, 1999
Creator: Goodin, S.
Object Type: Report
System: The UNT Digital Library
Defense Budget: Observations on the Air Force Flying Hour Program (open access)

Defense Budget: Observations on the Air Force Flying Hour Program

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Air Force's budget formulation process for its flying hour program for fiscal years (FY) 1997 through 1999, focusing on: (1) the extent to which the Air Force has flown the hours requested in its budget; (2) the process that the Air Force uses to determine flying hour requirements; (3) how the requirements and specific cost factors are used to develop the budget estimate for the flying hour program; and (4) program funding and obligations incurred in FY 1997 and FY 1998 and the reasons for the differences."
Date: July 8, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Design and Analysis of a Micro-Optical Position Readout for Acceleration Sensing (open access)

Design and Analysis of a Micro-Optical Position Readout for Acceleration Sensing

Sandia National Laboratories is developing a MEMS-based trajectory safety subsystem, which allows enablement of critical functions only after a particular acceleration environment has been achieved. The device, known as an Environmental Sensing Device (ESD), consists of a suspended moving shuttle that translates a given distance when exposed to an appropriate acceleration environment. The shuttle contains an embedded code, consisting of grating structures, that is illuminated and optically read using a semiconductor laser and detector integrated together in a GaAs-based Photonic Integrated Circuit (PIC) flip-chip bonded to the assembly. This paper will describe the optical design and performance analysis of the embedded code features in the shuttle.
Date: July 8, 1999
Creator: Dickey, Fred M.; Holswade, Scott C. & Shagam, Richard N.
Object Type: Article
System: The UNT Digital Library
Developing a cross-platform port simulation system. (open access)

Developing a cross-platform port simulation system.

With the advent of networked computer systems that connect disparate computer hardware and operating systems, it is important for port simulation systems to be able to run on a wide variety of computer platforms. This paper describes the design and implementation issues in reengineering the PORTSIM model in order to field the model to Windows-based systems as well as to Unix-based systems such as the Sun, Silicon Graphics, and HP workstations. The existing PORTSIM model was written to run on a Sun workstation running Unix. The model was initially implemented in MODSIM and C and utilized embedded SQL to retrieve port, ship, and cargo data from back-end OMCLE databases. Output reports, graphs, and tables for model results were written in C, utilizing third-party graphics libraries. This design and implementation worked well for the intended hardware platform and configuration, but as the number of model users grew and as the capabilities of the model expanded, a need developed to field the model to varying hardware configurations. This new requirement demanded that the existing design be modified to more easily allow for model fielding and maintenance. A phased approach is described that (1) identifies the existing model from which cross-platform development began, …
Date: July 8, 1999
Creator: Nevins, M. R.
Object Type: Article
System: The UNT Digital Library
Development of an Integrated Global Energy Model (open access)

Development of an Integrated Global Energy Model

The primary objective of this research was to develop a forefront analysis tool for application to enhance understanding of long-term, global, nuclear-energy and nuclear-material futures. To this end, an existing economics-energy-environmental (E{sup 3}) model was adopted, modified, and elaborated to examine this problem in a multi-regional (13), long-term ({approximately}2,100) context. The E{sup 3} model so developed was applied to create a Los Alamos presence in this E{sup 3} area through ''niche analyses'' that provide input to the formulation of policies dealing with and shaping of nuclear-energy and nuclear-materials futures. Results from analyses using the E{sup 3} model have been presented at a variety of national and international conferences and workshops. Through use of the E{sup 3} model Los Alamos was afforded the opportunity to participate in a multi-national E{sup 3} study team that is examining a range of global, long-term nuclear issues under the auspices of the IAEA during the 1998-99 period . Finally, the E{sup 3} model developed under this LDRD project is being used as an important component in more recent Nuclear Material Management Systems (NMMS) project.
Date: July 8, 1999
Creator: Krakowski, Robert A.
Object Type: Report
System: The UNT Digital Library
The development of Sn-Li coolant/breeding material for APEX/ALPS applications. (open access)

The development of Sn-Li coolant/breeding material for APEX/ALPS applications.

A Sn-Li alloy has been identified to be a coolant/breeding material for D-T fusion applications. The key feature of this material is its very low vapor pressure, which will be very useful for free surface concepts employed in APEX, ALPS and inertial confinement fission. The vapor is dominated by lithium, which has very low Z. Initial assessment of the material indicates acceptable tritium breeding capability, high thermal conductivity, expected low tritium volubility, and expected low chemical reactivities with water and air. Some key concerns are the high activation and material compatibility issues. The initial assessment of this material, for fission applications, is presented in this paper.
Date: July 8, 1999
Creator: Sze, D.-K.
Object Type: Article
System: The UNT Digital Library
DOD Animal Research: Controls on Animal Use Are Generally Effective, but Improvements Are Needed (open access)

DOD Animal Research: Controls on Animal Use Are Generally Effective, but Improvements Are Needed

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO examined the Department of Defense's (DOD) management and oversight of its animal research programs, focusing on the extent projects funded or performed by DOD utilizing animals: (1) were directed toward military objectives; (2) unnecessarily duplicated other research; and (3) incorporated alternatives that reduced, replaced, or refined the use of animals."
Date: July 8, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Environmental Protection Agency: Regional Haze Regulations (open access)

Environmental Protection Agency: Regional Haze Regulations

Other written product issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO reviewed the Environmental Protection Agency's (EPA) new rule on regional haze regulations. GAO noted that: (1) the rule calls for states to establish goals and emission reduction strategies for improving visibility in all 156 mandatory Class I national parks and wilderness areas; (2) specific provisions are included in the rule allowing nine western states to implement the recommendations of the Grand Canyon Visibility Transport Commission within the framework of the national regional haze program; and (3) EPA complied with applicable requirements in promulgating the rule."
Date: July 8, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Environmentally benign manufacturing of compact disc stampers [Final Phase II report] (open access)

Environmentally benign manufacturing of compact disc stampers [Final Phase II report]

Optical data storage is currently a $10B/yr. business. With the introduction of the high capacity Digital Versatile Disc (D/D) as well as the continued growth of CD-Audio and CD-ROM worldwide sales of optical data products as a whole are growing at rate of more than 10% per year. In North America, more than 2.5 billion optical discs will be sold in 1998. By 1999, the numbers of optical discs produced for the North American market will grow to almost three billion. The optical disc manufacturing industry is dominated by Asian and European companies (e.g. Sony of Japan and Philips of Netherlands). Prism Corporation has created a process that could significantly improve US competitiveness in the business of optical disc production. The objectives of the Phase II STTR project were to build and test an ion machining system (IMS) for stamper fabrication, prove overall manufacturing system feasibility by fabrication stampers and replicas, and evaluate alternative materials and alternative process parameters to optimize the process. During tie period of the Phase II project Prism Corporation was able to meet these objectives. In the course of doing so, adjustments had been made to better the project and in turn the final product. An …
Date: July 8, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Experiences Using a Meta-Data Based Integration Infrastructure (open access)

Experiences Using a Meta-Data Based Integration Infrastructure

A data warehouse that presents data from many of the genomics community data sources in a consistent, intuitive fashion has long been a goal of bioinformatics. Unfortunately, it is one of the goals that has not yet been achieved. One of the major problems encountered by previous attempts has been the high cost of creating and maintaining a warehouse in a dynamic environment. In this abstract we have outlined a meta-data based approach to integrating data sources that begins to address this problem. We have used this infrastructure to successfully integrate new sources into an existing warehouse in substantially less time than would have traditionally been required--and the resulting mediators are more maintainable than the traditionally defined ones would have been. In the final paper, we will describe in greater detail both our architecture and our experiences using this framework. In particular, we will outline the new, XML based representation of the meta-data, describe how the mediator generator works, and highlight other potential uses for the meta-data.
Date: July 8, 1999
Creator: Critchlow, T.; Masick, R. & Slezak, T.
Object Type: Article
System: The UNT Digital Library
Flight Performance of UV Filters on the ALEXIS Satellite (open access)

Flight Performance of UV Filters on the ALEXIS Satellite

The ALEXIS (Array of Low-Energy X-ray Imaging Sensors) mission, serving as the first dedicated all-sky monitor in the extreme UV, has been collecting data since its launch in 1993. ALEXIS operates in a 70{degree} inclination orbit at an altitude of 800 km. The ALEXIS science mission is to observe the cosmic UV background and to study variability of EUV sources. The ALEXIS experiment is composed of six telescopes. Although the telescopes were only designed for a one-year technology verification mission, they are still functioning with much the same effectiveness as at the beginning of the mission. The telescopes comprise: (1) layered synthetic microstructure (LSM) spherical mirrors, (2) thin foil filters, and (3) microchannel plate (MCP) detectors, all enshrouded within the telescope body. The LSM mirrors select the bandpass for each telescope, while rejecting some of the HeII 304{angstrom} geocoronal radiation. The filters, constructed either from aluminum/carbon or Lexan/titanium/boron, serve to strongly reject the geocoronal radiation, as well as longer wavelength emission from bright OB stars. Each telescope detector consists of two plates, the outermost of which is curved to accurately match the spherical focal surface of the mirror. By reviewing the ground and flight histories, this paper analyzes the flight …
Date: July 8, 1999
Creator: Bloch, J.J.; Roussel-Dupre, D. & Starin, S.
Object Type: Article
System: The UNT Digital Library
Food Stamp Program: Households Collect Benefits for Persons Disqualified for Intentional Program Violations (open access)

Food Stamp Program: Households Collect Benefits for Persons Disqualified for Intentional Program Violations

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on households collecting Food Stamp benefits for persons disqualified for intentional program violations, focusing on: (1) how many individuals were included as members of food stamp households in four states while disqualified from the program in calendar year 1997 and estimated the value of the benefits that were improperly issued to those households; and (2) why these individuals were improperly included in households and what actions the Department of Agriculture (USDA) and state agencies could take to detect and prevent disqualified participation."
Date: July 8, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Gas Phase Chemical Detection with an Integrated Chemical Analysis System (open access)

Gas Phase Chemical Detection with an Integrated Chemical Analysis System

Microfabrication technology has been applied to the development of a miniature, multi-channel gas phase chemical laboratory that provides fast response, small size, and enhanced versatility and chemical discrimination. Each analysis channel includes a sample concentrator followed by a gas chromatographic separator and a chemically selective surface acoustic wave detector array to achieve high sensitivity and selectivity. The performance of the components, individually and collectively, is described. The design and performance of novel micromachined acoustic wave devices, with the potential for improved chemical sensitivity, are also described.
Date: July 8, 1999
Creator: Baca, Albert G.; Casalnuovo, Stephen A.; Frye-Mason, Gregory C.; Heller, Edwin J.; Hietala, Susan L.; Hietala, Vincent M. et al.
Object Type: Article
System: The UNT Digital Library
High-Aspect-Ratio Nanophotonic Components Fabricated by Cl(2) RIBE (open access)

High-Aspect-Ratio Nanophotonic Components Fabricated by Cl(2) RIBE

We describe highly anisotropic reactive ion beam etching of nanophotonic structures in AlGaAs based on the ion beam divergence angle and chamber pressure. The divergence angle is shown to influence the shape of the upper portion of the etch while the chamber pressure controls the shape of the lower portion. This predictable region of parameter space resulted in highly anisotropic nanostructures. Deeply etched distributed Bragg reflectors are etched to an aspect ratio of 8:1 with 100 nm trench widths. The profile of the grating etch is straight with smooth sidewalls, flat bottoms, and squared corners. Two-dimensional photonic crystal post arrays are fabricated with smooth and vertical sidewalls, with structures as small as 180 nm in diameter and 2.0 {micro}m in height.
Date: July 8, 1999
Creator: Zubrzycki, W. J.; Vawter, G. A. & Wendt, J. R.
Object Type: Article
System: The UNT Digital Library
High-resolution wavefront control of high-power laser systems (open access)

High-resolution wavefront control of high-power laser systems

Nearly every new large-scale laser system application at LLNL has requirements for beam control which exceed the current level of available technology. For applications such as inertial confinement fusion, laser isotope separation, laser machining, and laser the ability to transport significant power to a target while maintaining good beam quality is critical. There are many ways that laser wavefront quality can be degraded. Thermal effects due to the interaction of high-power laser or pump light with the internal optical components or with the ambient gas are common causes of wavefront degradation. For many years, adaptive optics based on thing deformable glass mirrors with piezoelectric or electrostrictive actuators have be used to remove the low-order wavefront errors from high-power laser systems. These adaptive optics systems have successfully improved laser beam quality, but have also generally revealed additional high-spatial-frequency errors, both because the low-order errors have been reduced and because deformable mirrors have often introduced some high-spatial-frequency components due to manufacturing errors. Many current and emerging laser applications fall into the high-resolution category where there is an increased need for the correction of high spatial frequency aberrations which requires correctors with thousands of degrees of freedom. The largest Deformable Mirrors currently available …
Date: July 8, 1999
Creator: Brase, J.; Brown, C.; Carrano, C.; Kartz, M.; Olivier, S.; Pennington, D. et al.
Object Type: Article
System: The UNT Digital Library
Improved Oil Recovery in Mississippian Carbonate Reservoirs of Kansas -- Near-Term -- Class 2 (open access)

Improved Oil Recovery in Mississippian Carbonate Reservoirs of Kansas -- Near-Term -- Class 2

This report describes progress during the third year of the project entitled ''Improved Oil Recovery in Mississippian Carbonate Reservoirs in Kansas''. This project funded under the Department of Energy's Class 2 program targets improving the reservoir performance of mature oil fields located in shallow shelf carbonate reservoirs. The focus of this project is development and demonstration of cost-effective reservoir description and management technologies to extend the economic life of mature reservoirs in Kansas and mid-continent. The project introduced a number of potentially useful technologies, and demonstrated these technologies in actual oil field operations. Advanced technology was tailored specifically to the scale appropriate to the operations of Kansas producers. An extensive technology transfer effort is ongoing. Traditional technology transfer methods (e.g., publications and workshops) are supplemented with a public domain relational database and an online package of project results that is available through the Internet. The goal is to provide the independent complete access to project data, project results and project technology on their desktop. Included in this report is a summary of significant project results at the demonstration site (Schaben Field, Ness County, Kansas). The value of cost-effective techniques for reservoir characterization and simulation at Schaben Field were demonstrated to …
Date: July 8, 1999
Creator: Carr, Timothy R.; Green, Don W. & Willhite, G. Paul
Object Type: Report
System: The UNT Digital Library
Master equipment list 500 CFM portable exhauster POR-005 skid C (open access)

Master equipment list 500 CFM portable exhauster POR-005 skid C

The Master Equipment List (MEL) lists all the major components of the 500 cfm exhauster PORO5. The purpose of this Master Equipment List is to provide basic information and references to other documents for the listed components.
Date: July 8, 1999
Creator: KRISKOVICH, J.R.
Object Type: Report
System: The UNT Digital Library