ULXs, Microblazars, and the Unidentified EGERT Sources (open access)

ULXs, Microblazars, and the Unidentified EGERT Sources

We suggest that ultraluminous X-ray sources (ULXs) and some of the variable low latitude EGRET gamma-ray sources may be two different manifestations of the same underlying phenomena: high-mass microquasars with relativistic jets forming a small angle with the line of sight (i.e. microblazars). Microblazars with jets formed by relatively cool plasma (Lorentz factors for the leptons up to a few hundreds) naturally lead to ULXs. If the jet contains very energetic particles (high-energy cutoff above Lorentz factors of several thousands) the result is a relatively strong gamma-ray source. As pointed out by Kaufman Bernads, Romero & Mirabel (2002), a gamma-ray microblazar will always have an X-ray counterpart (although it might be relatively weak), whereas X-ray microblazars might have no gamma-ray counterparts.
Date: May 1, 2003
Creator: Butt, Y M; Romero, G E & Torres, D F
Object Type: Article
System: The UNT Digital Library
How to Determine The Precession of the Inner Accretion Disk in Cygnus X-1 (open access)

How to Determine The Precession of the Inner Accretion Disk in Cygnus X-1

We show that changes in the orientation of the inner accretion disk of Cygnus X-1 affect the shape of the broad Fe K{alpha} emission line emitted from this object, in such a way that eV-level spectral resolution observations (such as those that will be carried out by the ASTRO-E2 satellite) can be used to analyze the dynamics of the disk. We here present a new diagnosis tool, supported by numerical simulations, by which short observations of Cygnus X-1, separated in time, can determine whether its accretion disk actually processes, and if so, determine its period and precession angle. Knowing the precession parameters of Cygnus X-1 would result in a clarification of the origin of such precession, distinguishing between tidal and spin-spin coupling. This approach could also be used for similar studies in other microquasar systems.
Date: January 5, 2005
Creator: Torres, D F; Romero, G E; Barcons, X & Lu, Y
Object Type: Article
System: The UNT Digital Library
Probing the precession of the inner accretion disk in Cygnus X-1 (open access)

Probing the precession of the inner accretion disk in Cygnus X-1

None
Date: March 3, 2005
Creator: Torres, D F; Romero, G E; Barcons, X & Lu, Y
Object Type: Article
System: The UNT Digital Library
Theoretical Modelling of the Diffuse Emission of (gamma)-rays From Extreme Regions of Star Formation: The Case of Arp 220 (open access)

Theoretical Modelling of the Diffuse Emission of (gamma)-rays From Extreme Regions of Star Formation: The Case of Arp 220

Our current understanding of ultraluminous infrared galaxies suggest that they are recent galaxy mergers in which much of the gas in the former spiral disks, particularly that located at distances less than 5 kpc from each of the pre-merger nuclei, has fallen into a common center, triggering a huge starburst phenomenon. This large nuclear concentration of molecular gas has been detected by many groups, and estimates of molecular mass and density have been made. Not surprisingly, these estimates were found to be orders of magnitude larger than the corresponding values found in our Galaxy. In this paper, a self-consistent model of the high energy emission of the super-starburst galaxy Arp 220 is presented. The model also provides an estimate of the radio emission from each of the components of the central region of the galaxy (western and eastern extreme starbursts, and molecular disk). The predicted radio spectrum is found as a result of the synchrotron and free-free emission, and absorption, of the primary and secondary steady population of electrons and positrons. The latter is output of charged pion decay and knock-on leptonic production, subject to a full set of losses in the interstellar medium. The resulting radio spectrum is in …
Date: July 9, 2004
Creator: Torres, D F
Object Type: Article
System: The UNT Digital Library
Energy in Mexico: a profile of solar energy activity in its national context (open access)

Energy in Mexico: a profile of solar energy activity in its national context

The geopolitical, economic, and cultural aspects of the United States of Mexico are presented. Mexico's energy profile includes the following: energy policy objectives, government energy structure, organizations for implementation, indigeneous energy sources, imported energy sources, solar energy research and development, solar energy organizations and solar energy related legislation and administrative policies. International agreements, contacts, manufacturers, and projects are listed. (MRH)
Date: April 1, 1980
Creator: Hawkins, D.
Object Type: Report
System: The UNT Digital Library
Laser based micro forming and assembly. (open access)

Laser based micro forming and assembly.

It has been shown that thermal energy imparted to a metallic substrate by laser heating induces a transient temperature gradient through the thickness of the sample. In favorable conditions of laser fluence and absorptivity, the resulting inhomogeneous thermal strain leads to a measurable permanent deflection. This project established parameters for laser micro forming of thin materials that are relevant to MESA generation weapon system components and confirmed methods for producing micrometer displacements with repeatable bend direction and magnitude. Precise micro forming vectors were realized through computational finite element analysis (FEA) of laser-induced transient heating that indicated the optimal combination of laser heat input relative to the material being heated and its thermal mass. Precise laser micro forming was demonstrated in two practical manufacturing operations of importance to the DOE complex: micrometer gap adjustments of precious metal alloy contacts and forming of meso scale cones.
Date: November 1, 2006
Creator: MacCallum, Danny O'Neill; Wong, Chung-Nin Channy; Knorovsky, Gerald Albert; Steyskal, Michele D.; Lehecka, Tom; Scherzinger, William Mark et al.
Object Type: Report
System: The UNT Digital Library
Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities (open access)

Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.
Date: October 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities (open access)

Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.
Date: October 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water (open access)

Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water

The subject of this report is chemistry and engineering for the application of heterogeneous photocatalysts. The state of the art in catalysts are forms of titanium dioxide or modifications thereof, but work on other heterogeneous catalysts is included.
Date: July 29, 1999
Creator: Blake, D. M.
Object Type: Report
System: The UNT Digital Library
Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water and Air--Update Number 4 to October 2001 (open access)

Bibliography of Work on the Heterogeneous Photocatalytic Removal of Hazardous Compounds from Water and Air--Update Number 4 to October 2001

This report is the fifth in a series of bibliographies of work on the photocatalytic oxidation of organic or inorganic compounds in air or water and on the photocatalytic reduction of inorganic compounds in water. This search contains information extracted from 1149 new references to papers, books, and reports from searches conducted between October 1996 and April 2001.
Date: November 19, 2001
Creator: Blake, D.
Object Type: Report
System: The UNT Digital Library
Mexico City air quality research initiative, volume 3, modeling and simulation (open access)

Mexico City air quality research initiative, volume 3, modeling and simulation

The objective of the modeling and simulation task was to develop, test, and apply an appropriate set of models that could translate emission changes into air quality changes. Specifically, we wanted to develop models that could describe how existing measurements of ozone (O{sub 3}), carbon monoxide (CO), and sulfur dioxide (SO{sub 2}) would be expected to change if their emissions were changed. The modeling must be able to address the effects of difference in weather conditions and changes in land use as well as the effects of changes in emission levels. It must also be able to address the effects of changes in the nature and distribution of the emissions as well as changes in the total emissions. A second objective was to provide an understanding of the conditions that lead to poor air quality in Mexico City. We know in a general sense that Mexico City`s poor air quality is the result of large quantities of emissions in a confined area that is subject to light winds, but we did not know much about many aspects of the problem. For example, is the air quality on a given day primarily the result of emissions on that day...or is there …
Date: June 1, 1994
Creator: Mauzy, A.
Object Type: Report
System: The UNT Digital Library
ORIGINS AND HISTORY OF THE LOS ALAMOS MESON PHYSICS FACILITY. (open access)

ORIGINS AND HISTORY OF THE LOS ALAMOS MESON PHYSICS FACILITY.

None
Date: January 1, 1972
Creator: Livingston, M. Stanley
Object Type: Report
System: The UNT Digital Library
Keeping checkpoint/restart viable for exascale systems. (open access)

Keeping checkpoint/restart viable for exascale systems.

Next-generation exascale systems, those capable of performing a quintillion (10{sup 18}) operations per second, are expected to be delivered in the next 8-10 years. These systems, which will be 1,000 times faster than current systems, will be of unprecedented scale. As these systems continue to grow in size, faults will become increasingly common, even over the course of small calculations. Therefore, issues such as fault tolerance and reliability will limit application scalability. Current techniques to ensure progress across faults like checkpoint/restart, the dominant fault tolerance mechanism for the last 25 years, are increasingly problematic at the scales of future systems due to their excessive overheads. In this work, we evaluate a number of techniques to decrease the overhead of checkpoint/restart and keep this method viable for future exascale systems. More specifically, this work evaluates state-machine replication to dramatically increase the checkpoint interval (the time between successive checkpoint) and hash-based, probabilistic incremental checkpointing using graphics processing units to decrease the checkpoint commit time (the time to save one checkpoint). Using a combination of empirical analysis, modeling, and simulation, we study the costs and benefits of these approaches on a wide range of parameters. These results, which cover of number of high-performance …
Date: September 1, 2011
Creator: Riesen, Rolf E.; Bridges, Patrick G. (IBM Research, Ireland, Mulhuddart, Dublin); Stearley, Jon R.; Laros, James H., III; Oldfield, Ron A.; Arnold, Dorian (University of New Mexico, Albuquerque, NM) et al.
Object Type: Report
System: The UNT Digital Library
AAAR 28th Annual Conference Symposia Focusing on Topics of Interest to the U.S. DOE Atmospheric Science Program - October 26-30, 2009 (open access)

AAAR 28th Annual Conference Symposia Focusing on Topics of Interest to the U.S. DOE Atmospheric Science Program - October 26-30, 2009

This report addresses the secondary aerosol is an important component of atmospheric fine particles that generally consists of organics, sulfates, and nitrates.
Date: October 26, 2009
Creator: Ziemann, Paul
Object Type: Article
System: The UNT Digital Library
Workshop on the role of natural analogs in geologic disposal of high-level nuclear waste: Proceedings (open access)

Workshop on the role of natural analogs in geologic disposal of high-level nuclear waste: Proceedings

A Workshop on the Role of Natural Analogs in Geologic Disposal of High-Level Nuclear Waste was held in San Antonio, Texas on July 22--25, 1991. The proceedings comprise seventeen papers submitted by participants at the workshop. A series of papers addresses the relation of natural analog studies to the regulation, performance assessment, and licensing of a geologic repository. Applications of reasoning by analogy are illustrated in papers on the role of natural analogs in studies of earthquakes, petroleum, and mineral exploration. A summary is provided of a recently completed, internationally coordinated natural analog study at Pocos de Caldas, Brazil. Papers also cover problems and applications of natural analog studies in four technical areas of nuclear waste management-. waste form and waste package, near-field processes and environment, far-field processes and environment, and volcanism and tectonics. Summaries of working group deliberations in these four technical areas provide reviews and proposals for natural analog applications. Individual papers have been cataloged separately.
Date: September 1, 1995
Creator: Kovach, L.A. & Murphy, W.M.
Object Type: Article
System: The UNT Digital Library
Ninth Workshop on Geothermal Reservoir Engineering: Proceedings (open access)

Ninth Workshop on Geothermal Reservoir Engineering: Proceedings

The attendance at the Workshop was similar to last year's with 123 registered participants of which 22 represented 8 foreign countries. A record number of technical papers (about 60) were submitted for presentation at the Workshop. The Program Committee, therefore, decided to have several parallel sessions to accommodate most of the papers. This format proved unpopular and will not be repeated. Many of the participants felt that the Workshop lost some of its unique qualities by having parallel sessions. The Workshop has always been held near the middle of December during examination week at Stanford. This timing was reviewed in an open discussion at the Workshop. The Program Committee subsequently decided to move the Workshop to January. The Tenth Workshop will be held on January 22-24, 1985. The theme of the Workshop this year was ''field developments worldwide''. The Program Committee addressed this theme by encouraging participants to submit field development papers, and by inviting several international authorities to give presentations at the Workshop. Field developments in at least twelve countries were reported: China, El Salvador, France, Greece, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, the Philippines, and the United States. There were 58 technical presentations at the Workshop, of …
Date: December 15, 1983
Creator: Ramey, H. J., Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E. & Gudmundsson, J.S.
Object Type: Article
System: The UNT Digital Library
Fourteenth workshop geothermal reservoir engineering: Proceedings (open access)

Fourteenth workshop geothermal reservoir engineering: Proceedings

The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.
Date: January 1, 1989
Creator: Ramey, H. J., Jr.; Kruger, P.; Horne, R. N.; Miller, F. G.; Brigham, W. E. & Cook, J. W.
Object Type: Article
System: The UNT Digital Library
Fourteenth workshop geothermal reservoir engineering: Proceedings (open access)

Fourteenth workshop geothermal reservoir engineering: Proceedings

The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.
Date: December 31, 1989
Creator: Ramey, H. J. Jr.; Kruger, P.; Horne, R. N.; Miller, F. G.; Brigham, W. E. & Cook, J. W.
Object Type: Article
System: The UNT Digital Library
UNIVERSITY OF CALIFORNIA RESEARCH AND DEVELOPMENT (UCDRD) ACTIVITIES FOR FISCAL YEAR 1998 (open access)

UNIVERSITY OF CALIFORNIA RESEARCH AND DEVELOPMENT (UCDRD) ACTIVITIES FOR FISCAL YEAR 1998

None
Date: December 1, 1999
Creator: PORTER, J. C.
Object Type: Report
System: The UNT Digital Library
APS Science 2007. (open access)

APS Science 2007.

This report provides research highlights from the Advanced Photon Source (APS). Although these highlights represent less than 10% of the published work from the APS in 2007, they give a flavor of the diversity and impact of user research at the facility. In the strategic planning the aim is to foster the growth of existing user communities and foresee new areas of research. This coming year finds the APS engaged in putting together, along with the users, a blueprint for the next five years, and making the case for a set of prioritized investments in beamlines, the accelerator, and infrastructure, each of which will be transformational in terms of scientific impact. As this is written plans are being formulated for an important user workshop on October 20-21, 2008, to prioritize strategic plans. The fruit from past investments can be seen in this report. Examples include the creation of a dedicated beamline for x-ray photon correlation spectroscopy at Sector 8, the evolution of dedicated high-energy x-ray scattering beamlines at sectors 1 and 11, a dedicated imaging beamline at Sector 32, and new beamlines for inelastic scattering and powder diffraction. A single-pulse facility has been built in collaboration with Sector 14 (BioCARS) …
Date: May 30, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Proceedings of the second United Nations symposium on the development and use of geothermal resources held at San Francisco, California, May 20--29, 1975. Volume 1 (open access)

Proceedings of the second United Nations symposium on the development and use of geothermal resources held at San Francisco, California, May 20--29, 1975. Volume 1

The 299 papers in the Proceedings are presented in three volumes and are divided into twelve sections, each section dealing with a different aspect of geothermal energy. Rapporturs' summaries of the contents of each section are grouped together in Vol. 1 of the Proceedings; a separate abstract was prepared for each summary. Volume 1 also contains ninety-eight papers under the following section headings: present status of resources development; geology, hydrology, and geothermal systems; and geochemical techniques in exploration. Separate abstracts were prepared for ninety-seven papers. One paper was previously abstracted for ERA and appeared as CONF-750525--17. (LBS)
Date: 1976
Creator: unknown
Object Type: Article
System: The UNT Digital Library
2010 Annual Progress Report: DOE Hydrogen Program (open access)

2010 Annual Progress Report: DOE Hydrogen Program

In the past year, the DOE Hydrogen Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.
Date: February 1, 2011
Creator: unknown
Object Type: Report
System: The UNT Digital Library