U.S. Energy Information Administration (EIA) Indexed Site
gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation...
F.O.B. Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
API Gravity (Dollars per Barrel) Period: Monthly Annual Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes API Gravity Jul-15 ...
Revised API Gravity ranges of EIA-182 Crude Streams
Gasoline and Diesel Fuel Update (EIA)
API Gravity Ranges of Selected Crude Streams, EIA-182 Gravity 20 or less Alabama Heavy Ca - Coalinga Ca - Cymric Ca - Kern River Ca - Lost Hills Ca - Midway-Sunset Ca OCS - Hondo Ca OCS - Pescado Ca - Wilmington Mississippi Baxterville Gravity 20.1 to 25.0 Ca - Belridge South West Central TX Gravity 25.1 to 30.0 Alaska North Slope Wy Sour Gravity 30.1 to 35.0 Alaska South GC - Eugene Island GC - Heavy Louisiana Sweet (HLS) GC - Hoops Blend GC - Mars Blend La - Louisiana South Mix Montana Sour
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
18.62 19.26 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." 23. Domestic Crude Oil First Purchase Prices by API Gravity Energy...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
20.23 20.91 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." 23. Domestic Crude Oil First Purchase Prices by API Gravity Energy...
,"Domestic Crude Oil First Purchase Prices by API Gravity"
U.S. Energy Information Administration (EIA) Indexed Site
API Gravity" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Domestic Crude Oil First Purchase Prices by API Gravity",6,"Monthly","12/2015","10/15/1993" ,"Release Date:","3/1/2016" ,"Next Release Date:","4/1/2016" ,"Excel File
U.S. Energy Information Administration (EIA) Indexed Site
Florida, Georgia, North Carolina, South Carolina, Virginia, West Virginia. PAD District II: Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska,...
Alternative Fuels Data Center: ASTM Biodiesel Specifications
ASTM Biodiesel Specifications to someone by E-mail Share Alternative Fuels Data Center: ASTM Biodiesel Specifications on Facebook Tweet about Alternative Fuels Data Center: ASTM Biodiesel Specifications on Twitter Bookmark Alternative Fuels Data Center: ASTM Biodiesel Specifications on Google Bookmark Alternative Fuels Data Center: ASTM Biodiesel Specifications on Delicious Rank Alternative Fuels Data Center: ASTM Biodiesel Specifications on Digg Find More places to share Alternative Fuels Data
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Performance (perfSONAR) Software & Tools Development Data for Researchers Partnerships Publications Workshops Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies News & Publications ESnet News Publications and Presentations Galleries ESnet Awards and Honors Blog ESnet Live Home » Network R&D » Data for Researchers » SNMP API Network R&D Software-Defined Networking (SDN) Experimental Network Testbeds Performance (perfSONAR)
Energy Science and Technology Software Center (OSTI)
2012-04-01
We are seeking a code review of patches against DyninstAPI 8.0. DyninstAPI is an open source binary instrumentation library from the University of Wisconsin and University of Maryland. Our patches port DyninstAPI to the BlueGene/P and BlueGene/Q systems, as well as fix DyninstAPI bugs and implement minor new features in DyninstAPI.
Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Progress: ASTM Specifications and 2nd Generation Biodiesel Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel Presentation given at the 2007 Diesel ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
How It Works Who's Using OSCARS? OSCARS and Future Tech OSCARS Standard and Open Grid Forum OSCARS Developers Community Web Browser Interface (WBUI) Web Service Interface (API) ...
Biodiesel ASTM Update and Future Technical Needs | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Biodiesel ASTM Update and Future Technical Needs Biodiesel ASTM Update and Future Technical Needs Latest ASTM fuel specifications on biodiesel blends are summarized as well as future needs for improved fuel quality, process quality controls, and new performance testing procedures. PDF icon deer08_howell.pdf More Documents & Publications Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel Recent Research to Address Technical Barriers to Increased Use of Biodiesel Biodiesel
API is now deprecated http:en.openei.orgcommunityblogutility-rate-database-version-1-api-now-deprecated
There comes a time in every API version's lifecycle when it needs to...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Service Interface (API) Engineering Services The Network OSCARS How It Works Who's Using OSCARS? OSCARS and Future Tech OSCARS Standard and Open Grid Forum OSCARS Developers Community Web Browser Interface (WBUI) Web Service Interface (API) Read More... Fasterdata IPv6 Network Network Performance Tools The ESnet Engineering Team Contact Us Technical Assistance: 1 800-33-ESnet (Inside US) 1 800-333-7638 (Inside US) 1 510-486-7600 (Globally) 1 510-486-7607 (Globally) Report Network Problems:
X:\\Data_Publication\\Pma\\current\\ventura\\pma00.vp
U.S. Energy Information Administration (EIA) Indexed Site
gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation...
X:\\L6046\\Data_Publication\\Pma\\current\\ventura\\pma.vp
U.S. Energy Information Administration (EIA) Indexed Site
gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM: American Society for Testing and Materials. Aviation...
Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Progress: ASTM Specifications and 2nd Generation Biodiesel Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel Presentation given at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT). PDF icon deer07_howell.pdf More Documents & Publications Biodiesel ASTM Update and Future
1986-03-01
Copyright American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA, 19428, USA. This document is available from NTIS under license from ASTM.
ASTM PV INSTALLATON COMMISSIONING, OPERATIONS & MAINTENNCE (ICOMP) STANDARD PRACTICE
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ASTM PV INSTALLATON COMMISSIONING, OPERATIONS & MAINTENNCE (ICOMP) STANDARD PRACTICE MEETING ANNOUNCEMENT ASTM International subcommittee E44.09 Photovoltaic Electric Power Conversion will be holding a meeting for their WK43549 Practice for Installation Commissioning Operation and Maintenance Process task group on Thursday, May 8, 2014 at 8:00am until 1:00pm. This meeting will follow the Sandia/EPRI 2014 PV Systems Symposium. The scope of WK43549 is to work with others around the world to
Energy Science and Technology Software Center (OSTI)
2004-07-01
This code provides an application programming interface to the Macintosh OSX Carbon Databrowser from Macintosh Common Lisp. The Databrowser API is made available to Lisp via high level native CLOS classes and methods, obviating the need to write low-level Carbon code. This code is primarily glue in that its job is to provide an interface between two extant software tools: Macintosh Common Lisp and the OSX Databrowser, both of which are COTS products from privatemore » vendors. The Databrowser is an extremely useful user interface widget that is provided with Apples OSX (and to some extent, OS9) operating systems. One Apple-sanctioned method for using the Databrowser is via an API called Carbon, which is designed for C and C++ programmers. We have translated the low-level Carbon programming interface to the Databrowser into high-level object-oriented Common Lisp calls, functions, methods. and classes to enable MCL programmers to more readily take advantage of the Databrowser from Lisp programs.« less
Correlations estimate volume distilled using gravity, boiling point
Moreno, A.; Consuelo Perez de Alba, M. del; Manriquez, L.; Guardia Mendoz, P. de la
1995-10-23
Mathematical nd graphic correlations have been developed for estimating cumulative volume distilled as a function of crude API gravity and true boiling point (TBP). The correlations can be used for crudes with gravities of 21--34{degree} API and boiling points of 150--540 C. In distillation predictions for several mexican and Iraqi crude oils, the correlations have exhibited accuracy comparable to that of laboratory measurements. The paper discusses the need for such a correlation and the testing of the correlation.
by Ianjkalin(84) Contributor 23 September, 2012 - 15:52 Datapalooza Announcements APIs Big Data Datapalooza EDI EERE Open Data OpenEI New data has been liberated Rmckeel's...
of interest to center. Selected API information will be displayed below. Alternatively, you can download a CSV with this API data. Last reviewed on 08.23.2013 Powered by OpenEI...
Collaboration Topics - Acceleration Hardware and APIs | National...
National Nuclear Security Administration (NNSA)
Simulation and Computing and Institutional R&D Programs NNSACEA Cooperation in Computer Science Collaboration Topics - Acceleration Hardware and APIs Collaboration...
tagging API | OpenEI Community
REEEP REEGLE structured tagging API Reegle and OpenEI share the vision that easy access to energy information will help drive future developments in clean energy development....
Performance Tools & APIs | Argonne Leadership Computing Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
& Profiling Performance Tools & APIs Tuning MPI on BGQ Tuning and Analysis Utilities (TAU) HPCToolkit HPCTW mpiP gprof Profiling Tools Darshan PAPI BGQ Performance Counters...
Api Nova Energia Srl | Open Energy Information
search Name: Api Nova Energia Srl Place: Roma, Italy Zip: 198 Sector: Renewable Energy Product: Develops, builds, finances, acquires, owns and operates energy production...
Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
through 1980 reflect the month of reporting; values since then reflect the month of acquisition, which can be the month of loading, the month of landing, or sometime between those...
Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51, "Transfer Pricing Report," January 1979 through September 1982; Form EP-51,...
Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
2010 2011 2012 2013 2014 2015 View History 20.0º or Less 15.13 17.20 16.66 16.20 18.49 19.81 1978-2015 20.1º to 25.0º 26.01 27.47 29.77 33.87 36.73 38.79 1978-2015 25.1º to 30.0º 5.35 6.02 8.41 8.74 9.78 8.29 1978-2015 30.1º to 35.0º 30.73 30.64 28.31 29.98 26.96 25.22 1978-2015 35.1º to 40.0º 14.35 13.42 12.84 9.67 7.19 7.35 1978-2015 40.1º to 45.0º 5.57 3.58 3.36 1.28 0.75 0.45 1978-2015 45.1º or Greater 2.86 1.68 0.65 0.27 0.11 0.11 1978
Landed Costs of Imported Crude by API Gravity
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
2010 2011 2012 2013 2014 2015 View History 20.0º or Less 71.54 96.89 97.49 95.87 85.31 43.30 1978-2015 20.1º to 25.0º 71.07 93.32 91.32 88.35 81.44 41.32 1978-2015 25.1º to 30.0º 78.35 106.06 105.92 101.63 93.64 49.40 1978-2015 30.1º to 35.0º 79.64 108.76 107.23 102.97 95.20 50.74 1978-2015 35.1º to 40.0º 81.25 110.93 107.27 104.39 94.50 50.93 1978-2015 40.1º to 45.0º 81.09 115.40 112.70 110.66 100.17 54.54 1978-2015 45.1º or Greater 82.17 113.24 115.67 105.88 100.25 52.11 1978
Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
1978; Form ERA-51, "Transfer Pricing Report," January 1979 through September 1982; Form EP-51, "Monthly Foreign Crude Oil Transaction Report," October 1982 through June 1984; Form...
Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51,...
Percentages of Total Imported Crude Oil by API Gravity
Gasoline and Diesel Fuel Update (EIA)
Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 View History 20.0º or Less 20.86 23.41 22.05 18.64 19.05 18.63 1983-2015 20.1º to 25.0º 38.10 36.65 35.89 38.42 41.86 46.59 1983-2015 25.1º to 30.0º 7.57 W 8.69 8.00 7.40 3.93 1983-2015 30.1º to 35.0º 23.42 24.30 25.82 28.39 24.55 22.10 1983-2015 35.1º to 40.0º 9.22 7.74 7.37 6.43 6.87 8.50 1983-2015 40.1º to 45.0º 0.82 W W W W W 1983-2015 45.1º or Greater W W W W 1983
Domestic Crude Oil First Purchase Prices by API Gravity
Gasoline and Diesel Fuel Update (EIA)
2010 2011 2012 2013 2014 2015 View History 20.0º or Less 72.40 101.30 102.79 99.40 87.83 43.88 1993-2015 20.1º to 25.0º 75.04 103.07 101.56 100.70 91.05 45.71 1993-2015 25.1º to 30.0º 71.78 97.12 96.64 94.13 85.48 40.73 1993-2015 30.1º to 35.0º 76.22 99.65 98.48 99.11 90.95 46.82 1993-2015 35.1º to 40.0º 76.03 94.54 93.12 96.24 86.56 44.68 1993-2015 40.0º or Greater 74.48 91.87 91.01 94.76 86.12 43
Landed Costs of Imported Crude by API Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Landed Costs of Imported Crude by API Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Values shown for the current two months are preliminary. Values shown for the previous two months may be revised to account for late submissions and corrections. Final revisions to monthly and annual values are available upon publication of the June Petroleum Marketing Monthly. Annual averages that precede the release of the June Petroleum Marketing Monthly are calculated from monthly data. Data through 2014 are final.
Domestic Crude Oil First Purchase Prices by API Gravity
Gasoline and Diesel Fuel Update (EIA)
Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 View History 20.0º or Less 47.95 40.76 42.34 41.25 37.26 31.39 1993-2015 20.1º to 25.0º 49.38 41.02 42.74 42.49 38.86 34.15 1993-2015 25.1º to 30.0º 45.38 35.09 38.20 38.34 33.90 26.70 1993-2015 30.1º to 35.0º 47.99 43.65 42.93 44.48 39.32 34.00 1993-2015 35.1º to 40.0º 47.99 40.15 42.52 43.01 38.95 32.56 1993-2015 40.0º or Greater 46.86 38.18 40.81 41.78 37.79 31
Costs of Imported Crude Oil by API Gravity
Gasoline and Diesel Fuel Update (EIA)
1993 January ... 11.69 12.53 15.50 16.21 17.71 17.57 W February ... 12.19 13.21 16.75 16.98 18.68 18.67 18.63 March ... 12.81 13.71...
U.S. Energy Information Administration (EIA) Indexed Site
gravity of 22 degrees or below. Interme- diate crudes fall in the range of 22 degrees to 38 de- grees API gravity. ASTM: American Society for Testing and Materials. Aviation...
What is the Vehicle API? | OpenEI Community
What is the Vehicle API? Home > Groups > Developer The vehicle API does not seem to contain any end point. Is there some documentation about this service? http:...
U.S. Energy Information Administration | Petroleum Marketing Monthly
Gasoline and Diesel Fuel Update (EIA)
Glossary API gravity: An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it may be calculated in terms of the following formula: The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the range of 22 degrees to 38 degrees API gravity. ASTM:
The JANA Calibrations and Conditions Database API
David Lawrence
2010-07-01
Calibrations and conditions databases can be accessed from within the JANA Event Processing framework through the API defined in its JCalibration base class. The API is designed to support everything from databases, to web services to flat files for the backend. A Web Service backend using the gSOAP toolkit has been implemented which is particularly interesting since it addresses many modern cybersecurity issues including support for SSL. The API allows constants to be retrieved through a single line of C++ code with most of the context, including the transport mechanism, being implied by the run currently being analyzed and the environment relieving developers from implementing such details.
ASTM sampling methods and analytical validation for lead in paint, dust, soil, and air
Ashley, K.; Schlecht, P.C.; Song, R.; Feng, A.; DeWalt, G.; McKnight, M.E.
1996-12-31
ASTM Subcommittee E06.23 on Abatement/Mitigation of Lead Hazards has developed a number of standards that are concerned with the sampling of leas in environmental media, namely paint, dust, soil and airborne particulate. An ASTM practice for the collection of airborne particulate lead in the workplace has been published. New ASTM standards for the collection of dry paint film samples, surface soil samples, and surface dust wipe samples for subsequent lead analysis have also been promulgated. Other draft standards pertinent to lead sampling are under development. The ASTM standards concerned with lead sample collection are accompanied by separate sample preparation standard practices and a standard analysis method. Sample preparation and analytical methods have been evaluated by interlaboratory testing; such analyses may be used to assess the efficacy of sampling protocols.
Overview of API (COPM) - measurement activities
Beckstrom, J.C.
1995-12-01
The American Petroleum Institute was founded in 1919 as an outgrowth of the National Petroleum War Committee. That committee was comprised of U.S. oil industry leaders who worked together with the federal government to meet the tremendous demand for petroleum fuel during World War I. The experience demonstrated that, oil industry representatives could work together on common problems affecting the industry and still compete with one another in the marketplace. This in an important concept because under U.S. antitrust law, industry competitors can work together toward mutual objectives using API as the forum. API was the first national petroleum trade association to include all five of the major branches of the industry - exploration, production, refining, transportation and marketing. Today, API is the oil industry`s largest trade association with about 250 member companies. As a non-profit organization, API`s objectives, as set fort in its charter, are: (1) Promote the interests of the U.S. oil industry; (2) Encourage the development of petroleum technology; (3) Cooperate with government on matters of national concern; (4) Foster foreign and domestic trade in U.S. petroleum products; and (5) Inform government and the general public on matters affecting the petroleum industry.
OpenEI API. Implementation help | OpenEI Community
OpenEI API. Implementation help Home > Groups > Developer Hi Everyone, I am trying to determine the best way to consume the OpenEI utility rates and have come across the REST API....
Wolf, T.; Fritz, G.T.; Palmer, L.R.
1981-08-01
A standard testing procedure has been devised for fixed-wavelength photometric detectors (FWPD) used in liquid chromatography. The need for this procedure, the objectives for developing it, and the means for accomplishing the objectives are outlined. Salient details of the procedure are discussed including the determination of nine characteristics of FWPDs. After an evaluation by ten laboratories, the revised procedure was balloted and revised again according to ASTM procedures (1). The final revised version is now available from ASTM as Standard Practice E 685 (2).
QER- Comment of American petroleum Institute (API)
Broader source: Energy.gov [DOE]
Please find attached API's comments (and associated attachments) to the Department of Energy's Public Comment on the Quadrennial Energy Review [79 FR 50638, Doc. No. 2014-20114]. Please do not hesitate to contact me should you have any questions or need anything else.
Lujan, Richard E. (Santa Fe, NM)
2001-01-01
A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.
PROJECT PROFILE: UtilityAPI (Incubator 10) | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
UtilityAPI (Incubator 10) PROJECT PROFILE: UtilityAPI (Incubator 10) Project Title: Software for Automatic Utility Data Collection for Solar Proposals utilityapi logo.png Funding Opportunity: SunShot Technology to Market (Incubator 10) SunShot Subprogram: Technology to Market Location: Oakland, CA Amount Awarded: $762,530 Awardee Cost Share: $1,146,290 Project Investigator: Elena Lucas UtilityAPI is automating the process of authorizing, collecting, and cleaning electricity data from utilities.
Investigating an API for resilient exascale computing. (Technical...
Office of Scientific and Technical Information (OSTI)
This report describes an initial investigation of fault types and programming interfaces to mitigate them. Proof-of-concept APIs are presented for the frequent and important cases ...
Is nonrelativistic gravity possible?
Kocharyan, A. A.
2009-07-15
We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.
Reegle mentions OpenEI in video on new Content Pool API | OpenEI...
featured in the video, describes how the reegle tagging api structures and enriches big, unstructured data, turning data into knowledge. The tagging API analyzes documents,...
Impact of ASTM Standard E722 update on radiation damage metrics.
DePriest, Kendall Russell
2014-06-01
The impact of recent changes to the ASTM Standard E722 is investigated. The methodological changes in the production of the displacement kerma factors for silicon has significant impact for some energy regions of the 1-MeV(Si) equivalent fluence response function. When evaluating the integral over all neutrons energies in various spectra important to the SNL electronics testing community, the change in the response results in an increase in the total 1-MeV(Si) equivalent fluence of 2 7%. Response functions have been produced and are available for users of both the NuGET and MCNP codes.
Quantum Field Theory & Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
begin? What is its large scale structure and evolution? How can gravity be unified with quantum mechanics and the Standard Model? Quantum Field Theory, Gravity & Cosmology There...
White Paper Summary of 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding
Sindelar, R.; Louthan, M.; PNNL, B.
2015-05-29
This white paper recommends that ASTM International develop standards to address the potential impact of hydrides on the long term performance of irradiated zirconium alloys. The need for such standards was apparent during the 2nd ASTM International Workshop on Hydrides in Zirconium Alloy Cladding and Assembly Components, sponsored by ASTM International Committee C26.13 and held on June 10-12, 2014, in Jackson, Wyoming. The potentially adverse impacts of hydrogen and hydrides on the long term performance of irradiated zirconium-alloy cladding on used fuel were shown to depend on multiple factors such as alloy chemistry and processing, irradiation and post irradiation history, residual and applied stresses and stress states, and the service environment. These factors determine the hydrogen content and hydride morphology in the alloy, which, in turn, influence the response of the alloy to the thermo-mechanical conditions imposed (and anticipated) during storage, transport and disposal of used nuclear fuel. Workshop presentations and discussions showed that although hydrogen/hydride induced degradation of zirconium alloys may be of concern, the potential for occurrence and the extent of anticipated degradation vary throughout the nuclear industry because of the variations in hydrogen content, hydride morphology, alloy chemistry and irradiation conditions. The tools and techniques used to characterize hydrides and hydride morphologies and their impacts on material performance also vary. Such variations make site-to-site comparisons of test results and observations difficult. There is no consensus that a single material or system characteristic (e.g., reactor type, burnup, hydrogen content, end-of life stress, alloy type, drying temperature, etc.) is an effective predictor of material response during long term storage or of performance after long term storage. Multi-variable correlations made for one alloy may not represent the behavior of another alloy exposed to identical conditions and the material responses to thermo-mechanical exposures will be different depending on the materials and systems used. The discussions at the workshop showed several gaps in the standardization of processes and techniques necessary to assess the long term performance of irradiated zirconium alloy cladding during dry storage and transport. The development of, and adherence to, standards to help bridge these gaps will strengthen the technical basis for long term storage and post-storage operations, provide consistency across the nuclear industry, maximize the value of most observations, and enhance the understanding of behavioral differences among alloys. The need for, and potential benefits of, developing the recommended standards are illustrated in the various sections of this report.
OpenEI API listing | OpenEI Community
strategy conversation just this week, and we spoke somewhat indirectly about a list of energy APIs on OpenEI. We have the Energy Hackathon Resource page, but I want to draw energy...
Utility Rate API v2 | OpenEI Community
Hi, I am running into one issue with the API and that is using an ask query to get the data in the embedded multiple instance template fields. This is the last big problem that...
Investigating an API for resilient exascale computing. (Technical Report) |
Office of Scientific and Technical Information (OSTI)
SciTech Connect Technical Report: Investigating an API for resilient exascale computing. Citation Details In-Document Search Title: Investigating an API for resilient exascale computing. Increased HPC capability comes with increased complexity, part counts, and fault occurrences. In- creasing the resilience of systems and applications to faults is a critical requirement facing the viability of exascale systems, as the overhead of traditional checkpoint/restart is projected to outweigh its
Home Energy Score API User: Spirit Foundation | Department of Energy
Spirit Foundation Home Energy Score API User: Spirit Foundation The Spirit Foundation, a 501(c)(3) organization and Home Energy Score Partner, assists veterans and wounded heroes in sustainable careers. The Spirit Foundation offers Assessor training, sustainable energy evaluations, products, and services for both residential and commercial industries. The API team has released the SCORE! App for the Home Energy Score and is working on the release SCORE! V2.0, a multiplatform, multidevice
Investigating an API for resilient exascale computing. (Technical Report) |
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
SciTech Connect Investigating an API for resilient exascale computing. Citation Details In-Document Search Title: Investigating an API for resilient exascale computing. Increased HPC capability comes with increased complexity, part counts, and fault occurrences. In- creasing the resilience of systems and applications to faults is a critical requirement facing the viability of exascale systems, as the overhead of traditional checkpoint/restart is projected to outweigh its bene ts due to fault
Characterization of Multilayered Multipass Friction Stir Weld on ASTM A572 G50 Steel
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lim, Yong Chae; Sanderson, Samuel; Mahoney, Murray; Yu, Xinghua; Qiao, Dongxiao; Wang, Yanli; Zhang, Wei; Feng, Zhili
2014-01-01
A multilayered multipass friction stir weld (MM-FSW) on ASTM A572 Grade 50 steel was characterized to understand its potential application for thick-section structures. The 15-mm-thick section was fabricated by stacking up three steel plates and then friction stir welding the plates together in a total of 5 passes. The unique butt/lap joint configuration encountered in the multilayer weld was examined to understand the effect of tool rotation direction on the joint quality especially the formation of hooking defect. Charpy V-notch impact toughness tests showed generally higher impact toughness energy for the stir zone than the base metal with a ductilemore » fracture mode. The microhardness value was measured from 195 to 220 HV in the stir zone, while the base metal showed an average value of 170 HV. The microstructure in the stir zone and the adjacent heat affected zone was quantified using Optical and Scanning Electron Microscopy (SEM) including Electron Backscatter Diffraction (EBSD). The increased toughness and hardness were correlated with the refined microstructure in stir zone, resulting from severe plastic deformation and subsequent dynamic recrystallization during friction stir welding.« less
Characterization of Multilayered Multipass Friction Stir Weld on ASTM A572 G50 Steel
Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Yu, Xinghua [ORNL; Qiao, Dongxiao [ORNL; Wang, Yanli [ORNL; Zhang, Wei [ORNL; Feng, Zhili [ORNL
2014-01-01
A multilayered multipass friction stir weld (MM-FSW) on ASTM A572 Grade 50 steel was characterized to understand its potential application for thick-section structures. The 15-mm-thick section was fabricated by stacking up three steel plates and then friction stir welding the plates together in a total of 5 passes. The unique butt/lap joint configuration encountered in the multilayer weld was examined to understand the effect of tool rotation direction on the joint quality especially the formation of hooking defect. Charpy V-notch impact toughness tests showed generally higher impact toughness energy for the stir zone than the base metal with a ductile fracture mode. The microhardness value was measured from 195 to 220 HV in the stir zone, while the base metal showed an average value of 170 HV. The microstructure in the stir zone and the adjacent heat affected zone was quantified using Optical and Scanning Electron Microscopy (SEM) including Electron Backscatter Diffraction (EBSD). The increased toughness and hardness were correlated with the refined microstructure in stir zone, resulting from severe plastic deformation and subsequent dynamic recrystallization during friction stir welding.
Lorenz APIs and REST Services (Technical Report) | SciTech Connect
Office of Scientific and Technical Information (OSTI)
Lorenz APIs and REST Services Citation Details In-Document Search Title: Lorenz APIs and REST Services You are accessing a document from the Department of Energy's (DOE) SciTech ...
Help:US Utility Rate Database API Tutorial | Open Energy Information
with OpenEI API Requests to the OpenEI API can be made in the address bar of your internet search engine. The following is the base of the "request url" that allows a user to...
Visualize energy APIs with a new OpenEI browser | OpenEI Community
Rmckeel's picture Submitted by Rmckeel(297) Contributor 31 August, 2012 - 12:54 APIs Big Data cleanweb data OpenEI OpenEI has created a simple way to see energy APIs available...
Getting Rate Information from the utility_rates api | OpenEI...
Getting Rate Information from the utilityrates api Home > Groups > Utility Rate Hello, I am trying to use the API to generate information similar to what you can see here: http:...
V-142: Oracle Java Reflection API Flaw Lets Remote Users Execute...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
2: Oracle Java Reflection API Flaw Lets Remote Users Execute Arbitrary Code V-142: Oracle Java Reflection API Flaw Lets Remote Users Execute Arbitrary Code April 25, 2013 - 12:14am...
The utility rate database version 1 API is now deprecated | OpenEI...
The utility rate database version 1 API is now deprecated Home > Groups > Utility Rate Rmckeel's picture Submitted by Rmckeel(297) Contributor 6 September, 2013 - 14:00 API Utility...
Department of Energy Implements APIs in the Cloud | Department of Energy
Office of Environmental Management (EM)
Implements APIs in the Cloud Department of Energy Implements APIs in the Cloud November 9, 2012 - 2:43pm Addthis As part of the Digital Strategy, the Department of Energy is making more high-value data sets available through Application Program Interfaces (APIs) - helping programmers develop new opportunities, services and products for citizens. Additionally, these data sets and APIs are now housed on cloud-based servers, helping us to provide easy, scalable access to the public. Moving our data
Table 28. Percentages of Total Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
through 1980 reflect the month of reporting; values since then reflect the month of acquisition, which can be the month of loading, the month of landing, or sometime between those...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
through 1980 reflect the month of reporting; values since then reflect the month of acquisition, which can be the month of loading, the month of landing, or sometime between those...
Table 28. Percentages of Total Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51, "Transfer Pricing Report," January 1979 through September 1982; Form EP-51,...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51, "Transfer Pricing Report," January 1979 through September 1982; Form EP-51,...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
17.18 17.64 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information AdministrationPetroleum Marketing Annual 1999...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
reported. Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information Administration Petroleum Marketing Annual...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
12.17 12.80 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information AdministrationPetroleum Marketing Annual 1998...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
1978; Form ERA-51, "Transfer Pricing Report," January 1979 through September 1982; Form EP-51, "Monthly Foreign Crude Oil Transaction Report," October 1982 through June 1984; Form...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51,...
Table 28. Percentages of Total Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January 1978 through December 1978; Form ERA-51,...
F.O.B. Costs of Imported Crude Oil by API Gravity
Gasoline and Diesel Fuel Update (EIA)
F.O.B. Costs of Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
2009 2010 2011 2012 2013 2014 View History 20.0 or Less 54.76 69.51 94.66 96.07 93.91 82.40 1978-2014 20.1 to 25.0 54.36 69.72 94.15 94.35 91.27 80.16 1978-2014 25.1 to...
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
1993 January ... 4.52 18.16 22.93 28.47 23.99 1.48 0.45 February ... 4.19 18.11 19.48 35.50 17.92 3.57 1.22 March ... 4.98 18.66 20.35...
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Gasoline and Diesel Fuel Update (EIA)
1996 January ... 4.15 22.60 17.85 28.54 23.19 2.19 1.48 February ... 4.52 22.26 14.69 28.79 24.96 3.51 1.27 March ... 3.79 19.54 19.77...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
1997 January ... 18.57 19.34 23.73 22.13 24.80 23.89 23.89 February ... 14.79 17.00 21.18 19.69 22.81 22.74 24.44 March ... 14.56 16.06...
Saunders, W.; Benson, R.; Snelgrove, F.; Soloyanis, S.
1999-07-01
The ASTM Provisional Guide (PS 78-97) for Selecting Surface Geophysical Methods was developed as a guide for project managers, contractors, geologists, and geophysicists to assist in selecting the most likely geophysical method or methods to conduct specific subsurface investigations. Numerous surface geophysical methods and techniques exist that can be used to determine subsurface soil and rock properties and their distribution. These same methods are also widely used to investigate and locate manmade structures such as buried objective and landfills. This paper discusses the general uses of surface geophysics and the use of the provisional guide. This paper is not intended to be used as he guide. The ASTM Provisional Guide provides direction in selecting the most appropriate geophysical method or methods for a specific application under general site conditions. Secondary methods are also proposed that, under certain circumstances, should be evaluated before a final selection is made. Some typical conditions under which a primary or secondary method might or might not provide satisfactory results are given in the provisional guide. references for further information about selected methods and to method-specific ASTM guides are also provided. Secondary methods usually have less than desired performance, higher cost, or greater labor requirements as compared to the primary methods.
Collaboration Topics - Acceleration Hardware and APIs | National Nuclear
National Nuclear Security Administration (NNSA)
Security Administration Acceleration Hardware and APIs | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Library Bios Congressional Testimony Fact Sheets Newsletters Press Releases Photo Gallery Jobs
Development of ASTM Standard for SiC-SiC Joint Testing Final Scientific/Technical Report
Jacobsen, George; Back, Christina
2015-10-30
As the nuclear industry moves to advanced ceramic based materials for cladding and core structural materials for a variety of advanced reactors, new standards and test methods are required for material development and licensing purposes. For example, General Atomics (GA) is actively developing silicon carbide (SiC) based composite cladding (SiC-SiC) for its Energy Multiplier Module (EM2), a high efficiency gas cooled fast reactor. Through DOE funding via the advanced reactor concept program, GA developed a new test method for the nominal joint strength of an endplug sealed to advanced ceramic tubes, Fig. 1-1, at ambient and elevated temperatures called the endplug pushout (EPPO) test. This test utilizes widely available universal mechanical testers coupled with clam shell heaters, and specimen size is relatively small, making it a viable post irradiation test method. The culmination of this effort was a draft of an ASTM test standard that will be submitted for approval to the ASTM C28 ceramic committee. Once the standard has been vetted by the ceramics test community, an industry wide standard methodology to test joined tubular ceramic components will be available for the entire nuclear materials community.
Polchinski, Joseph [Kavli Institute for Theoretical Physics
2010-09-01
Gauge theories, which describe the particle interactions, are well understood, while quantum gravity leads to many puzzles. Remarkably, in recent years we have learned that these are actually dual, the same system written in different variables. On the one hand, this provides our most precise description of quantum gravity, resolves some long-standing paradoxes, and points to new principles. On the other, it gives a new perspective on strong interactions, with surprising connections to other areas of physics. I describe these ideas, and discuss current and future directions.
Library API for Z-Order Memory Layout
Energy Science and Technology Software Center (OSTI)
2015-02-01
This library provides a simple-to-use API for implementing an altnerative to traditional row-major order in-memory layout, one based on a Morton- order space filling curve (SFC) , specifically, a Z-order variant of the Morton order curve. The library enables programmers to, after a simple initialization step, to convert a multidimensional array from row-major to Z- order layouts, then use a single, generic API call to access data from any arbitrary (i,j,k) location from within themore » array, whether it it be stored in row- major or z-order format. The motivation for using a SFC in-memory layout is for improved spatial locality, which results in increased use of local high speed cache memory. The basic idea is that with row-major order layouts, a data access to some location that is nearby in index space is likely far away in physical memory, resulting in poor spatial locality and slow runtime. On the other hand, with a SFC-based layout, accesses that are nearby in index space are much more likely to also be nearby in physical memory, resulting in much better spatial locality, and better runtime performance. Numerous studies over the years have shown significant runtime performance gains are realized by using a SFC-based memory layout compared to a row-major layout, sometimes by as much as 50%, which result from the better use of the memory and cache hierarchy that are attendant with a SFC-based layout (see, for example, [Beth2012]). This library implementation is intended for use with codes that work with structured, array-based data in 2 or 3 dimensions. It is not appropriate for use with unstructured or point-based data.« less
How to get TOU information using REST API... | OpenEI Community
like I have to make more than one API calls (one for zip code to Utility etc.). I am OK with that. I found this page http:en.openei.orgservicesdocrestutilrates that...
API for current energy usage data per consumer | OpenEI Community
API for current energy usage data per consumer Home > Groups > Developer Hello, I'm a web application developer working on an app to determine an individuals environmental impact,...
Where can I find APIs and other resources for developers competing...
Where can I find APIs and other resources for developers competing at Cleanweb hackathons? Home > Groups > Developer Submitted by Rmckeel on 25 June, 2012 - 07:23 1 answer Points:...
A RESTful API for accessing microbial community data for MG-RAST
Wilke, Andreas; Bischof, Jared; Harrison, Travis; Brettin, Tom; D'Souza, Mark; Gerlach, Wolfgang; Matthews, Hunter; Paczian, Tobias; Wilkening, Jared; Glass, Elizabeth M.; Desai, Narayan; Meyer, Folker; Gardner, Paul P.
2015-01-08
Metagenomic sequencing has produced significant amounts of data in recent years. For example, as of summer 2013, MGRAST has been used to annotate over 110,000 data sets totaling over 43 Terabases. With metagenomic sequencing finding even wider adoption in the scientific community, the existing web-based analysis tools and infrastructure in MG-RAST provide limited capability for data retrieval and analysis, such as comparative analysis between multiple data sets. Moreover, although the system provides many analysis tools, it is not comprehensive. By opening MG-RAST up via a web services API (application programmers interface) we have greatly expanded access to MG-RAST data, as well as provided a mechanism for the use of third-party analysis tools with MG-RAST data. This RESTful API makes all data and data objects created by the MG-RAST pipeline accessible as JSON objects. As part of the DOE Systems Biology Knowledgebase project (KBase, http:// kbase.us) we have implemented a web services API for MG-RAST. This API complements the existing MG-RAST web interface and constitutes the basis of KBase’s microbial community capabilities. In addition, the API exposes a comprehensive collection of data to programmers. This API, which uses a RESTful (Representational State Transfer) implementation, is compatible with most programming environments and should be easy to use for end users and third parties. It provides comprehensive access to sequence data, quality control results, annotations, and many other data types. Where feasible, we have used standards to expose data and metadata. Code examples are provided in a number of languages both to show the versatility of the API and to provide a starting point for users. We present an API that exposes the data in MG-RAST for consumption by our users, greatly enhancing the utility of the MG-RAST service.
Home Energy Score API User: EnergySavvy | Department of Energy
EnergySavvy Home Energy Score API User: EnergySavvy EnergySavvy provides cloud-based software for the utility industry. Dedicated to making energy efficiency more controllable and transparent, EnergySavvy's Optix platform provides a modern user experience that delivers predictability to the industry. The Optix platform transforms the way utilities engage customers, automates demand-side management programs, and quantifies results. At New Jersey Natural Gas, EnergySavvy's customized API interface
A RESTful API for accessing microbial community data for MG-RAST
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wilke, Andreas; Bischof, Jared; Harrison, Travis; Brettin, Tom; D'Souza, Mark; Gerlach, Wolfgang; Matthews, Hunter; Paczian, Tobias; Wilkening, Jared; Glass, Elizabeth M.; et al
2015-01-08
Metagenomic sequencing has produced significant amounts of data in recent years. For example, as of summer 2013, MGRAST has been used to annotate over 110,000 data sets totaling over 43 Terabases. With metagenomic sequencing finding even wider adoption in the scientific community, the existing web-based analysis tools and infrastructure in MG-RAST provide limited capability for data retrieval and analysis, such as comparative analysis between multiple data sets. Moreover, although the system provides many analysis tools, it is not comprehensive. By opening MG-RAST up via a web services API (application programmers interface) we have greatly expanded access to MG-RAST data, asmore » well as provided a mechanism for the use of third-party analysis tools with MG-RAST data. This RESTful API makes all data and data objects created by the MG-RAST pipeline accessible as JSON objects. As part of the DOE Systems Biology Knowledgebase project (KBase, http:// kbase.us) we have implemented a web services API for MG-RAST. This API complements the existing MG-RAST web interface and constitutes the basis of KBase’s microbial community capabilities. In addition, the API exposes a comprehensive collection of data to programmers. This API, which uses a RESTful (Representational State Transfer) implementation, is compatible with most programming environments and should be easy to use for end users and third parties. It provides comprehensive access to sequence data, quality control results, annotations, and many other data types. Where feasible, we have used standards to expose data and metadata. Code examples are provided in a number of languages both to show the versatility of the API and to provide a starting point for users. We present an API that exposes the data in MG-RAST for consumption by our users, greatly enhancing the utility of the MG-RAST service.« less
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the Nuclear Fuel Cycle International Committee may bestow on an individual; and the Max Hecht Award, the highest award the Water International Committee can bestow on an - 2 -...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the Nuclear Fuel Cycle International Committee may bestow on an individual; and the Max Hecht Award, the highest award the Water International Committee can bestow on an...
Geometric scalar theory of gravity
Novello, M.; Bittencourt, E.; Goulart, E.; Salim, J.M.; Toniato, J.D.; Moschella, U. E-mail: eduhsb@cbpf.br E-mail: egoulart@cbpf.br E-mail: toniato@cbpf.br
2013-06-01
We present a geometric scalar theory of gravity. Our proposal will be described using the ''background field method'' introduced by Gupta, Feynman, Deser and others as a field theory formulation of general relativity. We analyze previous criticisms against scalar gravity and show how the present proposal avoids these difficulties. This concerns not only the theoretical complaints but also those related to observations. In particular, we show that the widespread belief of the conjecture that the source of scalar gravity must be the trace of the energy-momentum tensor which is one of the main difficulties to couple gravity with electromagnetic phenomenon in previous models does not apply to our geometric scalar theory. From the very beginning this is not a special relativistic scalar gravity. The adjective ''geometric'' pinpoints its similarity with general relativity: this is a metric theory of gravity. Some consequences of this new scalar theory are explored.
Gravity Methods | Open Energy Information
Methods Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gravity Methods Details Activities (0) Areas (0) Regions (0) NEPA(3) Exploration...
Gravity Techniques | Open Energy Information
in density, such as at fault contacts. 2 Gravity techniques are also applied towards reservoir monitoring for subsidence and mass gain or loss within a geothermal reservoir...
Geologic interpretation of gravity anomalies
Andreyev, B.A.; Klushin, I.G.
1990-04-19
This Russian textbook provides a sufficiently complete and systematic illumination of physico-geologic and mathematical aspect of complex problem of interpretation of gravity anomalies. The rational methods of localization of anomalies are examined in detail. All methods of interpreting gravity anomalies are described which have found successful application in practice. Also given are ideas of some new methods of the interpretation of gravity anomalies, the prospects for further development and industrial testing. Numerous practical examples to interpretation are given. Partial Contents: Bases of gravitational field theory; Physico-geologic bases of gravitational prospecting; Principles of geologic interpretation of gravity anomalies; Conversions and calculations of anomalies; Interpretation of gravity anomalies for bodies of correct geometric form and for bodies of arbitrary form; Geologic interpretation of the results of regional gravitational photographing; Searches and prospecting of oil- and gas-bearing structures and of deposits of ore and nonmetalliferous useful minerals.
Category:Gravity Techniques | Open Energy Information
the following 3 subcategories, out of 3 total. A Airborne Gravity Survey 1 pages G Ground Gravity Survey 1 pages M Microgravity-Hybrid Microgravity 1 pages...
Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65
Hashemi, S. H.; Mohammadyani, D.
2011-01-17
The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.
Quantum Field Theory & Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Quantum Field Theory & Gravity Quantum Field Theory & Gravity Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505) 667-5657 Email Quantum Field Theory and Gravity at Los Alamos The HEP effort at Los Alamos in this area is actively pursing a number of questions in this area. What is the final state of complete gravitational collapse? What happens at the event horizon? What is dark energy? How did the
Cosmological perturbations in unimodular gravity
Gao, Caixia; Brandenberger, Robert H.; Cai, Yifu; Chen, Pisin E-mail: rhb@hep.physics.mcgill.ca E-mail: chen@slac.stanford.edu
2014-09-01
We study cosmological perturbation theory within the framework of unimodular gravity. We show that the Lagrangian constraint on the determinant of the metric required by unimodular gravity leads to an extra constraint on the gauge freedom of the metric perturbations. Although the main equation of motion for the gravitational potential remains the same, the shift variable, which is gauge artifact in General Relativity, cannot be set to zero in unimodular gravity. This non-vanishing shift variable affects the propagation of photons throughout the cosmological evolution and therefore modifies the Sachs-Wolfe relation between the relativistic gravitational potential and the microwave temperature anisotropies. However, for adiabatic fluctuations the difference between the result in General Relativity and unimodular gravity is suppressed on large angular scales. Thus, no strong constraints on the theory can be derived.
Philosophy\tof\tNetwork\tOpera3ng Systems\tand\tIntent\tAPIs Inder...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
SDN ONF * ONOS - Carrier-grade SDN network opera3ng system that enables intent via JAVA modules, accessed via REST APIs. * NEMO - Network Modeling language which could serve...
Home Energy Scoring Tools (website) and Application Programming Interfaces, APIs (aka HEScore)
Energy Science and Technology Software Center (OSTI)
2012-05-01
A web-based residential energy rating tool with APIs that runs the LBNL website: Provides customized estimates of residential energy use and energy bills based on building description information provided by the user. Energy use is estimated using engineering models developed at LBNL. Space heating and cooling use is based on the DOE-2. 1E building simulation model. Other end-users (water heating, appliances, lighting, and misc. equipment) are based on engineering models developed by LBNL.
Home Energy Score API User: CakeSystems | Department of Energy
CakeSystems Home Energy Score API User: CakeSystems CakeSystems is a platform that helps efficiency programs, professionals, and homeowners implement scoring tools to help move the market forward. CakeSystems uses a flexible data collection platform to gather the data necessary for a Home Energy Score and incorporates that into other workflows for creating proposals, program tracking, and homeowner engagement. The information also populates in an offline mobile app, available for Android and iOS
Home Energy Score API User: OptiMiser | Department of Energy
OptiMiser Home Energy Score API User: OptiMiser OptiMiser software and data management tools are used by utilities, implementers, programs, and contractors across the country. Features include: Streamlined interface that provides continuous savings estimation Advanced utility bill analysis for accuracy and reduced data entry An array of reports and a built-in report editor A modifiable measures library, simple proposals, and detailed estimations ePortal to remotely pre-load, queue, retrieve, and
API-ANGA-IPAA-AXPC response letter SEAB FracFocus TF
Broader source: Energy.gov (indexed) [DOE]
March 25, 2014 Dr. John Deutch Chair, Secretary of Energy Advisory Board U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 SUBJECT: FracFocus 2.0 Task Force Report Draft Dear Dr. Deutch: The American Petroleum Institute ("API"), American's Natural Gas Alliance ("ANGA"), the Independent Petroleum Association of America ("IPAA"), and the American Exploration & Production Council ("AXPC") (collectively, "Associations")
Emergent Horava gravity in graphene
Volovik, G.E.; L. D. Landau Institute for Theoretical Physics, Kosygina 2, 119334 Moscow ; Zubkov, M.A.
2014-01-15
First of all, we reconsider the tight-binding model of monolayer graphene, in which the variations of the hopping parameters are allowed. We demonstrate that the emergent 2D Weitzenbock geometry as well as the emergent U(1) gauge field appear. The emergent gauge field is equal to the linear combination of the components of the zweibein. Therefore, we actually deal with the gauge fixed version of the emergent 2+1 D teleparallel gravity. In particular, we work out the case, when the variations of the hopping parameters are due to the elastic deformations, and relate the elastic deformations with the emergent zweibein. Next, we investigate the tight-binding model with the varying intralayer hopping parameters for the multilayer graphene with the ABC stacking. In this case the emergent 2D Weitzenbock geometry and the emergent U(1) gauge field appear as well, and the emergent low energy effective field theory has the anisotropic scaling. -- Highlights: The tight-binding model for graphene with varying hopping parameters is considered. The emergent gravity and emergent gauge fields are derived. For the case of the multilayer graphene we obtain the analogue of Horava gravity with anisotropic scaling.
Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer
Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M.; Bertoldi, A.; Bodart, Q.; Cacciapuoti, L.; Angelis, M. de; Prevedelli, M.
2012-09-10
We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.
Growth histories in bimetric massive gravity
Berg, Marcus; Buchberger, Igor; Enander, Jonas; Mrtsell, Edvard; Sjrs, Stefan E-mail: igor.buchberger@kau.se E-mail: edvard@fysik.su.se
2012-12-01
We perform cosmological perturbation theory in Hassan-Rosen bimetric gravity for general homogeneous and isotropic backgrounds. In the de Sitter approximation, we obtain decoupled sets of massless and massive scalar gravitational fluctuations. Matter perturbations then evolve like in Einstein gravity. We perturb the future de Sitter regime by the ratio of matter to dark energy, producing quasi-de Sitter space. In this more general setting the massive and massless fluctuations mix. We argue that in the quasi-de Sitter regime, the growth of structure in bimetric gravity differs from that of Einstein gravity.
Gravity Data for west-central Colorado
Zehner, Richard
2012-04-06
Modeled Bouger Gravity data was extracted from the Pan American Center for Earth and Environmental Studies Gravity Database of the U.S. at http://irpsrvgis08.utep.edu/viewers/Flex/GravityMagnetic/GravityMagnetic_CyberShare/ on 2/29/2012. The downloaded text file was opened in an Excel spreadsheet. This spreadsheet data was then converted into an ESRI point shapefile in UTM Zone 13 NAD27 projection, showing location and gravity (in milligals). This data was then converted to grid and then contoured using ESRI Spatial Analyst. This dataset contains the original spreadsheet data, a point shapefile showing gravity station locations and Bouger gravity, and a line shapefile showing 1 milligal contours. Projection: UTM Zone 13 NAD27 Gravity Contour Shapefile Extent: West -108.366690 East -105.478730 North 40.932318 South 36.961606 Gravity Point Shapefile Extent: West -108.366692 East -105.478847 North 40.932361 South 36.961606 Data from From University of Texas: Pan American Center for Earth and Environmental Studies
Airborne Gravity Survey | Open Energy Information
Gravity Techniques Information Provided by Technique Lithology: Distribution of density in the subsurface enables inference of rock type. StratigraphicStructural:...
Ground Gravity Survey | Open Energy Information
Et Al., 2000) Dixie Valley Geothermal Area 1999 2000 Precise Gravimetry and Geothermal Reservoir Management Ground Gravity Survey At Dixie Valley Geothermal Area (Blackwell, Et...
Naked singularities and quantum gravity
Harada, Tomohiro; Iguchi, Hideo; Nakao, Ken-ichi; Singh, T. P.; Tanaka, Takahiro; Vaz, Cenalo
2001-08-15
There are known models of spherical gravitational collapse in which the collapse ends in a naked shell-focusing singularity for some initial data. If a massless scalar field is quantized on the classical background provided by such a star, it is found that the outgoing quantum flux of the scalar field diverges in the approach to the Cauchy horizon. We argue that the semiclassical approximation (i.e., quantum field theory on a classical curved background) used in these analyses ceases to be valid about one Planck time before the epoch of naked singularity formation, because by then the curvature in the central region of the star reaches the Planck scale. It is shown that during the epoch in which the semiclassical approximation is valid, the total emitted energy is about one Planck unit, and is not divergent. We also argue that back reaction in this model does not become important so long as gravity can be treated classically. It follows that the further evolution of the star will be determined by quantum gravitational effects, and without invoking quantum gravity it is not possible to say whether the star radiates away on a short time scale or settles down into a black hole state.
HDF5-FastQuery: An API for Simplifying Access to Data Storage,Retrieval, Indexing and Querying
Bethel, E. Wes; Gosink, Luke; Shalf, John; Stockinger, Kurt; Wu,Kesheng
2006-06-15
This work focuses on research and development activities that bridge a gap between fundamental data management technology index, query, storage and retrieval and use of such technology in computational and computer science algorithms and applications. The work has resulted in a streamlined applications programming interface (API) that simplifies data storage and retrieval using the HDF5 data I/O library, and eases use of the FastBit compressed bitmap indexing software for data indexing/querying. The API, which we call HDF5-FastQuery, will have broad applications in domain sciences as well as associated data analysis and visualization applications.
Ground Gravity Survey At Clear Lake Area (Skokan, 1993) | Open...
Ground Gravity Survey At Clear Lake Area (Skokan, 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Clear Lake Area...
A new quasidilaton theory of massive gravity (Journal Article...
Office of Scientific and Technical Information (OSTI)
A new quasidilaton theory of massive gravity Citation Details In-Document Search Title: A new quasidilaton theory of massive gravity We present a new quasidilaton theory of...
Ground Gravity Survey At Coso Geothermal Area (1980) | Open Energy...
Ground Gravity Survey At Coso Geothermal Area (1980) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Coso Geothermal...
Ground Gravity Survey At Crump's Hot Springs Area (DOE GTP) ...
Ground Gravity Survey At Crump's Hot Springs Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Crump's Hot...
Category:Airborne Gravity Survey | Open Energy Information
Category Edit History Category:Airborne Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Airborne Gravity Survey...
Ground Gravity Survey At North Brawley Geothermal Area (Biehler...
Ground Gravity Survey At North Brawley Geothermal Area (Biehler, 1964) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At...
Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...
Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (FURUMOTO...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (FURUMOTO, 1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey...
Ground Gravity Survey At Snake River Plain Region (DOE GTP) ...
Ground Gravity Survey At Snake River Plain Region (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Snake River...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Thomas...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Broyles...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Broyles, Et Al., 1979) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity...
Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments...
Negative Effective Gravity in Water Waves by Periodic Resonator...
Office of Scientific and Technical Information (OSTI)
Negative Effective Gravity in Water Waves by Periodic Resonator Arrays Prev Next Title: Negative Effective Gravity in Water Waves by Periodic Resonator Arrays Authors: Hu,...
Del Bravo, R.; Pinacci, P.; Trifilo, R.
1998-07-01
This paper has the aim to give a general overview of the api Energia IGCC project starting from the project background in 1992 and ending with the progress of construction. api Energia S.p.A., a joint VENTURE between api anonima petroli italiana S.p.A., Roma, Italy (51%), ABB Sae Sadelmi S.p.A., Milano, Italy (25%) and Texaco Development Corporation (24%), is building a 280 MW Integrated Gasification Combined Cycle plant in the api refinery at Falconara Marittima, on Italy' s Adriatic coast, using heavy oil residues. The plant is based on the modern concept of employing a highly efficient combined cycle power plant fed with a low heating value fuel gas produced by gasifying heavy refinery residues. This scheme provides consistent advantages in terms of efficiency and environmental impact over alternative applications of the refinery residues. The electric power produced will feed the national grid. The project has been financed using the ``project financing'' scheme: over 1,000 billion Lira, representing 75% of the overall capital requirement, have been provided by a pool of international banks. In November 1996 the project reached financial closure and immediately after the detailed design and procurement activities started. Engineering, Procurement and Construction activities, carried out by a Consortium of companies of the ABB group, are totally in line with the schedule. Commercial operation of the plant, is scheduled for November 1999.
Quantum gravity and renormalization: The tensor track
Rivasseau, Vincent
2012-06-27
We propose a new program to quantize and renormalize gravity based on recent progress on the analysis of large random tensors. We compare it briefly with other existing approaches.
Gauge natural formulation of conformal gravity
Campigotto, M.; Fatibene, L.
2015-03-15
We consider conformal gravity as a gauge natural theory. We study its conservation laws and superpotentials. We also consider the Mannheim and Kazanas spherically symmetric vacuum solution and discuss conserved quantities associated to conformal and diffeomorphism symmetries.
Bouguer gravity map | Open Energy Information
LibraryAdd to library Map: Bouguer gravity mapInfo GraphicMapChart Cartographers J. Behrendt and L. Bajwa Organization U.S. Geological Survey Published U.S. Geological...
Gravity waves from cosmic bubble collisions
Salem, Michael P.; Saraswat, Prashant; Shaghoulian, Edgar E-mail: ps88@stanford.edu
2013-02-01
Our local Hubble volume might be contained within a bubble that nucleated in a false vacuum with only two large spatial dimensions. We study bubble collisions in this scenario and find that they generate gravity waves, which are made possible in this context by the reduced symmetry of the global geometry. These gravity waves would produce B-mode polarization in the cosmic microwave background, which could in principle dominate over the inflationary background.
Measuring antimatter gravity with muonium
Kaplan, Daniel M.; Kirch, Klaus; Mancini, Derrick; Phillips, James D.; Phillips, Thomas J.; Roberts, Thomas J.; Terry, Jeff; Bravina, L.; Foka, Y.; Kabana, S.
2015-05-29
The gravitational acceleration of antimatter, g, has never been directly measured and could bear importantly on our understanding of gravity, the possible existence of a fifth force, and the nature and early history of the universe. Only two avenues for such a measurement appear to be feasible: antihydrogen and muonium. The muonium measurement requires a novel, monoenergetic, low-velocity, horizontal muonium beam directed at an atom interferometer. The precision three-grating interferometer can be produced in silicon nitride or ultrananocrystalline diamond using state-of-the-art nanofabrication. The required precision alignment and calibration at the picometer level also appear to be feasible. With 100 nm grating pitch, a 10% measurement of g can be made using some months of surface-muon beam time, and a 1% or better measurement with a correspondingly larger exposure. This could constitute the first gravitational measurement of leptonic matter, of 2nd-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.
Measuring antimatter gravity with muonium
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kaplan, Daniel M.; Kirch, Klaus; Mancini, Derrick; Phillips, James D.; Phillips, Thomas J.; Roberts, Thomas J.; Terry, Jeff; Bravina, L.; Foka, Y.; Kabana, S.
2015-05-29
The gravitational acceleration of antimatter, ¯g, has never been directly measured and could bear importantly on our understanding of gravity, the possible existence of a fifth force, and the nature and early history of the universe. Only two avenues for such a measurement appear to be feasible: antihydrogen and muonium. The muonium measurement requires a novel, monoenergetic, low-velocity, horizontal muonium beam directed at an atom interferometer. The precision three-grating interferometer can be produced in silicon nitride or ultrananocrystalline diamond using state-of-the-art nanofabrication. The required precision alignment and calibration at the picometer level also appear to be feasible. With 100 nmmore » grating pitch, a 10% measurement of ¯g can be made using some months of surface-muon beam time, and a 1% or better measurement with a correspondingly larger exposure. This could constitute the first gravitational measurement of leptonic matter, of 2nd-generation matter and, possibly, the first measurement of the gravitational acceleration of antimatter.« less
Nonderivative modified gravity: a classification
Comelli, D.; Nesti, F.; Pilo, L. E-mail: fabrizio.nesti@irb.hr
2014-11-01
We analyze the theories of gravity modified by a generic nonderivative potential built from the metric, under the minimal requirement of unbroken spatial rotations. Using the canonical analysis, we classify the potentials V according to the number of degrees of freedom (DoF) that propagate at the nonperturbative level. We then compare the nonperturbative results with the perturbative DoF propagating around Minkowski and FRW backgrounds. A generic V implies 6 propagating DoF at the non-perturbative level, with a ghost on Minkowski background. There exist potentials which propagate 5 DoF, as already studied in previous works. Here, no V with unbroken rotational invariance admitting 4 DoF is found. Theories with 3 DoF turn out to be strongly coupled on Minkowski background. Finally, potentials with only the 2 DoF of a massive graviton exist. Their effect on cosmology is simply equivalent to a cosmological constant. Potentials with 2 or 5 DoF and explicit time dependence appear to be a further viable possibility.
Massive gravity wrapped in the cosmic web
Shim, Junsup; Lee, Jounghun; Li, Baojiu E-mail: jounghun@astro.snu.ac.kr
2014-03-20
We study how the filamentary pattern of the cosmic web changes if the true gravity deviates from general relativity (GR) on a large scale. The f(R) gravity, whose strength is controlled to satisfy the current observational constraints on the cluster scale, is adopted as our fiducial model and a large, high-resolution N-body simulation is utilized for this study. By applying the minimal spanning tree algorithm to the halo catalogs from the simulation at various epochs, we identify the main stems of the rich superclusters located in the most prominent filamentary section of the cosmic web and determine their spatial extents per member cluster to be the degree of their straightness. It is found that the f(R) gravity has the effect of significantly bending the superclusters and that the effect becomes stronger as the universe evolves. Even in the case where the deviation from GR is too small to be detectable by any other observables, the degree of the supercluster straightness exhibits a conspicuous difference between the f(R) and the GR models. Our results also imply that the supercluster straightness could be a useful discriminator of f(R) gravity from the coupled dark energy since it is shown to evolve differently between the two models. As a final conclusion, the degree of the straightness of the rich superclusters should provide a powerful cosmological test of large scale gravity.
Astrophysical black holes in screened modified gravity
Davis, Anne-Christine; Jha, Rahul; Muir, Jessica; Gregory, Ruth E-mail: r.a.w.gregory@durham.ac.uk E-mail: jlmuir@umich.edu
2014-08-01
Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect.
Charged black holes in generalized teleparallel gravity
Rodrigues, M.E.; Houndjo, M.J.S.; Tossa, J.; Momeni, D.; Myrzakulov, R. E-mail: sthoundjo@yahoo.fr E-mail: d.momeni@yahoo.com
2013-11-01
In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity.
Quantum gravity effects in the Kerr spacetime
Reuter, M.; Tuiran, E.
2011-02-15
We analyze the impact of the leading quantum gravity effects on the properties of black holes with nonzero angular momentum by performing a suitable renormalization group improvement of the classical Kerr metric within quantum Einstein gravity. In particular, we explore the structure of the horizons, the ergosphere, and the static limit surfaces as well as the phase space available for the Penrose process. The positivity properties of the effective vacuum energy-momentum tensor are also discussed and the 'dressing' of the black hole's mass and angular momentum are investigated by computing the corresponding Komar integrals. The pertinent Smarr formula turns out to retain its classical form. As for their thermodynamical properties, a modified first law of black-hole thermodynamics is found to be satisfied by the improved black holes (to second order in the angular momentum); the corresponding Bekenstein-Hawking temperature is not proportional to the surface gravity.
Differential geometry, Palatini gravity and reduction
Capriotti, S.
2014-01-15
The present article deals with a formulation of the so called (vacuum) Palatini gravity as a general variational principle. In order to accomplish this goal, some geometrical tools related to the geometry of the bundle of connections of the frame bundle LM are used. A generalization of Lagrange-Poincar reduction scheme to these types of variational problems allows us to relate it with the Einstein-Hilbert variational problem. Relations with some other variational problems for gravity found in the literature are discussed.
Ion source and beam guiding studies for an API neutron generator
Sy, A.; Ji, Q.; Persaud, A.; Ludewigt, B. A.; Schenkel, T.
2013-04-19
Recently developed neutron imaging methods require high neutron yields for fast imaging times and small beam widths for good imaging resolution. For ion sources with low current density to be viable for these types of imaging methods, large extraction apertures and beam focusing must be used. We present recent work on the optimization of a Penning-type ion source for neutron generator applications. Two multi-cusp magnet configurations have been tested and are shown to increase the extracted ion current density over operation without multi-cusp magnetic fields. The use of multi-cusp magnetic confinement and gold electrode surfaces have resulted in increased ion current density, up to 2.2 mA/cm{sup 2}. Passive beam focusing using tapered dielectric capillaries has been explored due to its potential for beam compression without the cost and complexity issues associated with active focusing elements. Initial results from first experiments indicate the possibility of beam compression. Further work is required to evaluate the viability of such focusing methods for associated particle imaging (API) systems.
Ground Gravity Survey At Neal Hot Springs Geothermal Area (Colwell...
and a nearby absolute gravity benchmark was tied in. Gravity data indicated a high density region in-between lower density regions to the east and west. The high density region...
The inverse-square law and quantum gravity
Nieto, M.M.; Goldman, T.; Hughes, R.J.
1988-01-01
This paper briefly discusses a modification to central potential of gravity when antimatter is involved and the possible existence of quantum gravity and a fifth force of nature. 1 ref. (LSP)
Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood...
(Fig. 2) shows a gravity low within the valley area that presumably is related to low-density Cenozoic sediments. The steep gravity gradient along the east side of the valley...
Zero-Gravity Centrifugal Force | GE Global Research
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
to create centrifugal force create its on gravity? Example if you were spinning a iron ball in space, just as the earth spins, does the iron ball create its on gravity? scott...
Ultrasonic hydrometer. [Specific gravity of electrolyte
Swoboda, C.A.
1982-03-09
The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.
U.S. Energy Information Administration (EIA) Indexed Site
Landed Costs of Imported Crude Oil by API Gravity (Dollars per Barrel) | | | | | | | Year | 20.0 |...
Junction conditions in extended Teleparallel gravities
De la Cruz-Dombriz, lvaro; Dunsby, Peter K.S.; Sez-Gmez, Diego E-mail: peter.dunsby@uct.ac.za
2014-12-01
In the context of extended Teleparallel gravity theories, we address the issue of junction conditions required to guarantee the correct matching of different regions of spacetime. In the absence of shells/branes, these conditions turn out to be more restrictive than their counterparts in General Relativity as in other extended theories of gravity. In fact, the general junction conditions on the matching hypersurfaces depend on the underlying theory and a new condition on the induced tetrads in order to avoid delta-like distributions in the field equations. This result imposes strict consequences on the viability of standard solutions such as the Einstein-Straus-like construction. We find that the continuity of the scalar torsion is required in order to recover the usual General Relativity results.
Gravity controlled anti-reverse rotation device
Dickinson, Robert J. (Shaler Township, Allegheny County, PA); Wetherill, Todd M. (Lower Burrell, PA)
1983-01-01
A gravity assisted anti-reverse rotation device for preventing reverse rotation of pumps and the like. A horizontally mounted pawl is disposed to mesh with a fixed ratchet preventing reverse rotation when the pawl is advanced into intercourse with the ratchet by a vertically mounted lever having a lumped mass. Gravitation action on the lumped mass urges the pawl into mesh with the ratchet, while centrifugal force on the lumped mass during forward, allowed rotation retracts the pawl away from the ratchet.
Regulation of flexible arms under gravity
De Luca, A.; Siciliano, B.
1993-08-01
A simple controller is presented for the regulation problem of robot arms with flexible links under gravity. It consists of a joint PD feedback plus a constant feedforward. Global asymptotic stability of the reference equilibrium state is shown under a structural assumption about link elasticity and a mild condition on the proportional gain. The result holds also in the absence of internal damping of the flexible arm. A numerical case study is presented.
Neutron stars as laboratories for gravity physics
Deliduman, Cemsinan
2014-01-01
We study the structure of neutron stars in R+?R gravity model with perturbative method. We obtain mass-radius relations for four representative equations of state (EoS). We find that, for |?|~10? cm, the results differ substantially from the results of general relativity. The effects of modified gravity are seen as mimicking a stiff or soft EoS for neutron stars depending upon whether ? is negative or positive, respectively. Some of the soft EoS that are excluded within the framework of general relativity can be reconciled for certain values of ? of this order with the 2 solar mass neutron star recently observed. Indeed, if the EoS is ever established to be soft, modified gravity of the sort studied here may be required to explain neutron star masses as large as 2 M{sub ?}. The associated length scale ?(?)~10? cm is of the order of the the typical radius of neutron stars implying that this is the smallest value we could find by using neutron stars as a probe. We thus conclude that the true value of ? is most likely much smaller than 10? cm.
Cosmology in general massive gravity theories
Comelli, D.; Nesti, F.; Pilo, L. E-mail: fabrizio.nesti@aquila.infn.it
2014-05-01
We study the cosmological FRW flat solutions generated in general massive gravity theories. Such a model are obtained adding to the Einstein General Relativity action a peculiar non derivative potentials, function of the metric components, that induce the propagation of five gravitational degrees of freedom. This large class of theories includes both the case with a residual Lorentz invariance as well as the case with rotational invariance only. It turns out that the Lorentz-breaking case is selected as the only possibility. Moreover it turns out that that perturbations around strict Minkowski or dS space are strongly coupled. The upshot is that even though dark energy can be simply accounted by massive gravity modifications, its equation of state w{sub eff} has to deviate from -1. Indeed, there is an explicit relation between the strong coupling scale of perturbations and the deviation of w{sub eff} from -1. Taking into account current limits on w{sub eff} and submillimiter tests of the Newton's law as a limit on the possible strong coupling scale, we find that it is still possible to have a weakly coupled theory in a quasi dS background. Future experimental improvements on short distance tests of the Newton's law may be used to tighten the deviation of w{sub eff} form -1 in a weakly coupled massive gravity theory.
Gravity dual of metastable dynamical supersymmetry breaking (Journal
Office of Scientific and Technical Information (OSTI)
Article) | SciTech Connect Gravity dual of metastable dynamical supersymmetry breaking Citation Details In-Document Search Title: Gravity dual of metastable dynamical supersymmetry breaking Metastable, supersymmetry-breaking configurations can be created in flux geometries by placing antibranes in warped throats. Via gauge/gravity duality, such configurations should have an interpretation as supersymmetry-breaking states in the dual field theory. In this paper, we perturbatively determine
A Gravity Dual of Metastable Dynamical Supersymmetry Breaking (Journal
Office of Scientific and Technical Information (OSTI)
Article) | SciTech Connect A Gravity Dual of Metastable Dynamical Supersymmetry Breaking Citation Details In-Document Search Title: A Gravity Dual of Metastable Dynamical Supersymmetry Breaking Metastable, supersymmetry-breaking configurations can be created in flux geometries by placing antibranes in warped throats. Via gauge/gravity duality, such configurations should have an interpretation as supersymmetry-breaking states in the dual field theory. In this paper, we perturbatively
Ground Gravity Survey At Roosevelt Hot Springs Geothermal Area...
Unknown Exploration Basis Faulder 1991 Conceptual Geological Model compilation and literature review of the Roosevelt Hot Springs Geothermal Area. Notes Gravity modeling and...
Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski...
Francisco Volcanic Field Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At San Francisco...
Category:Ground Gravity Survey | Open Energy Information
Apps Datasets Community Login | Sign Up Search Category Edit History Category:Ground Gravity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home...
Lorentz Invariant phenomenological model of quantum gravity: A minimalistic presentation
Bonder, Yuri
2012-08-24
The purpose of this paper is to give a minimalistic and self-contained presentation of a Lorentz Invariant phenomenological model of Quantum Gravity.
Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...
Finally, the gravity survey also shows anomalies that correlate with the seismic and microseismic data. All of these results will be integrated to obtain the most probable...
Gravity Survey of the Carson Sink - Data and Maps
Faulds, James E.
2013-12-31
A detailed gravity survey was carried out for the entire Carson Sink in western Nevada (Figure 1) through a subcontract to Zonge Engineering, Inc. The Carson Sink is a large composite basin containing three known, blind high‐temperature geothermal systems (Fallon Airbase, Stillwater, and Soda Lake). This area was chosen for a detailed gravity survey in order to characterize the gravity signature of the known geothermal systems and to identify other potential blind systems based on the structural setting indicated by the gravity data. Data: Data were acquired at approximately 400, 800, and 1600 meter intervals for a total of 1,243 stations. The project location and station location points are presented in Figure 14. The station distribution for this survey was designed to complete regional gravity coverage in the Carson Sink area without duplication of available public and private gravity coverage. Gravity data were acquired using a Scintrex CG‐5 gravimeter and a LaCoste and Romberg (L&R) Model‐G gravimeter. The CG‐5 gravity meter has a reading resolution of 0.001 milligals and a typical repeatability of less than 0.005 milligals. The L&R gravity meter has a reading resolution of 0.01 milligals and a typical repeatability of 0.02 milligals. The basic processing of gravimeter readings to calculate through to the Complete Bouguer Anomaly was made using the Gravity and Terrain Correction software version 7.1 for Oasis Montaj by Geosoft LTD. Results: The gravity survey of the Carson Sink yielded the following products. Project location and station location map (Figure 14). Complete Bouguer Anomaly @ 2.67 gm/cc reduction density. Gravity Complete Bouguer Anomaly at 2.50 g/cc Contour Map (Figure 15). Gravity Horizontal Gradient Magnitude Shaded Color Contour Map. Gravity 1st Vertical Derivative Color Contour Map. Interpreted Depth to Mesozoic Basement (Figure 16), incorporating drill‐hole intercept values. Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south‐central, east‐central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step‐overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.
Ground Gravity Survey At Truckhaven Area (Warpinski, Et Al.,...
2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Truckhaven Area (Warpinski, Et Al., 2004) Exploration Activity...
Ground Gravity Survey At Lake City Hot Springs Area (Warpinski...
Exploration Activity Details Location Lake City Hot Springs Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes The...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Leslie...
of the seaward extension of the ERZ. Gravity measurements of Puna Ridge show a high density anomaly at depth which corresponds to high velocity data obtained from seismic...
Ground Gravity Survey (Nannini, 1986) | Open Energy Information
depth inside the sedimentary formations of the basement and often present a negative density contrast when compared to the latter. Gravity could help to identify these bodies by...
Ground Gravity Survey At Rio Grande Rift Region (Aiken & Ander...
DOE-funding Unknown References Carlos L.V. Aiken, Mark E. Ander (1981) A Regional Strategy For Geothermal Exploration With Emphasis On Gravity And Magnetotellurics Additional...
Ground Gravity Survey At Blue Mountain Geothermal Area (Fairbank...
search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Blue Mountain Geothermal Area (Fairbank Engineering Ltd, 2003) Exploration Activity Details...
Ground Gravity Survey At Chocolate Mountains Area (Alm, Et Al...
Chocolate Mountains Area (Alm, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Chocolate Mountains Area...
Ground Gravity Survey At Coso Geothermal Area (1990) | Open Energy...
(1990) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1990 Usefulness not indicated DOE-funding Unknown...
Bouguer gravity anomalies, depth to bedrock, and shallow temperature...
Bouguer gravity anomalies, depth to bedrock, and shallow temperature in the Humboldt House geothermal area, Pershing County, Nevada Jump to: navigation, search OpenEI Reference...
A gravity model for the Coso geothermal area, California | Open...
Most of the gravity variations can be explained by two lithologic units: (1) low density wedges of Quarternary alluvium with interbedded thin basalts (2.4 gcmsup 3)...
Ground Gravity Survey At Lightning Dock Geothermal Area (Swanberg...
Basis Examination of geothermal resources of New Mexico Notes detailed gravity and magnetics survey of Lightning Dock to identify burried structures as a source of the thermal...
Ground Gravity Survey At Newberry Caldera Area (DOE GTP) | Open...
Newberry Caldera Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Newberry Caldera Area (DOE GTP)...
Ground Gravity Survey At Mcgee Mountain Area (DOE GTP) | Open...
Mcgee Mountain Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Mcgee Mountain Area (DOE GTP) Exploration...
Ground Gravity Survey At Walker Lake Valley Area (Shoffner, Et...
N. Hinz, A. Sabin, M. Lazaro, S. Alm (2010) Understanding Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada...
Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...
Ground Gravity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....
Ground Gravity Survey At Raft River Geothermal Area (1978) |...
search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Raft River Geothermal Area (1978) Exploration Activity Details Location Raft River...
Perturbations of nested branes with induced gravity
Sbis, Fulvio; Koyama, Kazuya E-mail: kazuya.koyama@port.ac.uk
2014-06-01
We study the behaviour of weak gravitational fields in models where a 4D brane is embedded inside a 5D brane equipped with induced gravity, which in turn is embedded in a 6D spacetime. We consider a specific regularization of the branes internal structures where the 5D brane can be considered thin with respect to the 4D one. We find exact solutions corresponding to pure tension source configurations on the thick 4D brane, and study perturbations at first order around these background solutions. To perform the perturbative analysis, we adopt a bulk-based approach and we express the equations in terms of gauge invariant and master variables using a 4D scalar-vector-tensor decomposition. We then propose an ansatz on the behaviour of the perturbation fields when the thickness of the 4D brane goes to zero, which corresponds to configurations where gravity remains finite everywhere in the thin limit of the 4D brane. We study the equations of motion using this ansatz, and show that they give rise to a consistent set of differential equations in the thin limit, from which the details of the internal structure of the 4D brane disappear. We conclude that the thin limit of the ''ribbon'' 4D brane inside the (already thin) 5D brane is well defined (at least when considering first order perturbations around pure tension configurations), and that the gravitational field on the 4D brane remains finite in the thin limit. We comment on the crucial role of the induced gravity term on the 5D brane.
Testing chameleon gravity with the Coma cluster
Terukina, Ayumu; Yamamoto, Kazuhiro; Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C. E-mail: lucas.lombriser@port.ac.uk E-mail: david.bacon@port.ac.uk E-mail: bob.nichol@port.ac.uk
2014-04-01
We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an attractive fifth force. The presence of an extra gravitational coupling, however, is tightly constrained by local measurements. In chameleon modifications of gravity, local tests can be evaded by employing a screening mechanism that suppresses the fifth force in dense environments. While the chameleon field may be screened in the interior of the cluster, its outer region can still be affected by the extra force, introducing a deviation between the hydrostatic and lensing mass of the cluster. Thus, the chameleon modification can be tested by combining the gas and lensing measurements of the cluster. We demonstrate the operability of our method with the Coma cluster, for which both a lensing measurement and gas observations from the X-ray surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect are available. Using the joint observational data set, we perform a Markov chain Monte Carlo analysis of the parameter space describing the different profiles in both the Newtonian and chameleon scenarios. We report competitive constraints on the chameleon field amplitude and its coupling strength to matter. In the case of f(R) gravity, corresponding to a specific choice of the coupling, we find an upper bound on the background field amplitude of |f{sub R0}| < 6 10{sup ?5}, which is currently the tightest constraint on cosmological scales.
Massive gravity on de Sitter and unique candidate for partially massless gravity
Rham, Claudia de; Renaux-Petel, Sbastien E-mail: srenaux@lpthe.jussieu.fr
2013-01-01
We derive the decoupling limit of Massive Gravity on de Sitter in an arbitrary number of space-time dimensions d. By embedding d-dimensional de Sitter into d+1-dimensional Minkowski, we extract the physical helicity-1 and helicity-0 polarizations of the graviton. The resulting decoupling theory is similar to that obtained around Minkowski. We take great care at exploring the partially massless limit and define the unique fully non-linear candidate theory that is free of the helicity-0 mode in the decoupling limit, and which therefore propagates only four degrees of freedom in four dimensions. In the latter situation, we show that a new Vainshtein mechanism is at work in the limit m{sup 2} ? 2H{sup 2} which decouples the helicity-0 mode when the parameters are different from that of partially massless gravity. As a result, there is no discontinuity between massive gravity and its partially massless limit, just in the same way as there is no discontinuity in the massless limit of massive gravity. The usual bounds on the graviton mass could therefore equivalently well be interpreted as bounds on m{sup 2}?2H{sup 2}. When dealing with the exact partially massless parameters, on the other hand, the symmetry at m{sup 2} = 2H{sup 2} imposes a specific constraint on matter. As a result the helicity-0 mode decouples without even the need of any Vainshtein mechanism.
A new quasidilaton theory of massive gravity
Mukohyama, Shinji
2014-12-01
We present a new quasidilaton theory of Poincare invariant massive gravity, based on the recently proposed framework of matter coupling that makes it possible for the kinetic energy of the quasidilaton scalar to couple to both physical and fiducial metrics simultaneously. We find a scaling-type exact solution that expresses a self-accelerating de Sitter universe, and then analyze linear perturbations around it. It is shown that in a range of parameters all physical degrees of freedom have non-vanishing quadratic kinetic terms and are stable in the subhorizon limit, while the effective Newton's constant for the background is kept positive.
A high frequency resonance gravity gradiometer
Bagaev, S. N.; Kvashnin, N. L.; Skvortsov, M. N.; Bezrukov, L. B.; Krysanov, V. A.; Oreshkin, S. I.; Motylev, A. M.; Popov, S. M.; Samoilenko, A. A.; Yudin, I. S.; Rudenko, V. N.
2014-06-15
A new setup OGRANthe large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare eventsgravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS.
Harko, Tiberiu; Lobo, Francisco S.N.; Otalora, G.; Saridakis, Emmanuel N. E-mail: flobo@cii.fc.ul.pt
2014-12-01
We present an extension of f(T) gravity, allowing for a general coupling of the torsion scalar T with the trace of the matter energy-momentum tensor T. The resulting f(T,T) theory is a new modified gravity, since it is different from all the existing torsion or curvature based constructions. Applied to a cosmological framework, it leads to interesting phenomenology. In particular, one can obtain a unified description of the initial inflationary phase, the subsequent non-accelerating, matter-dominated expansion, and then the transition to a late-time accelerating phase. Additionally, the effective dark energy sector can be quintessence or phantom-like, or exhibit the phantom-divide crossing during the evolution. Moreover, in the far future the universe results either to a de Sitter exponential expansion, or to eternal power-law accelerated expansions. Finally, a detailed study of the scalar perturbations at the linear level reveals that f(T,T) cosmology can be free of ghosts and instabilities for a wide class of ansatzes and model parameters.
Disformal transformations, veiled General Relativity and Mimetic Gravity
Deruelle, Nathalie; Rua, Josephine E-mail: rua@cbpf.br
2014-09-01
In this Note we show that Einstein's equations for gravity are generically invariant under ''disformations''. We also show that the particular subclass when this is not true yields the equations of motion of ''Mimetic Gravity''. Finally we give the ''mimetic'' generalization of the Schwarzschild solution.
Bimetric gravity doubly coupled to matter: theory and cosmological implications
Akrami, Yashar; Koivisto, Tomi S.; Mota, David F.; Sandstad, Marit E-mail: t.s.koivisto@astro.uio.no E-mail: marit.sandstad@astro.uio.no
2013-10-01
A ghost-free theory of gravity with two dynamical metrics both coupled to matter is shown to be consistent and viable. Its cosmological implications are studied, and the models, in particular in the context of partially massless gravity, are found to explain the cosmic acceleration without resorting to dark energy.
Massive gravitational waves in Chern-Simons modified gravity
Myung, Yun Soo; Moon, Taeyoon E-mail: tymoon@inje.ac.kr
2014-10-01
We consider the nondynamical Chern-Simons (nCS) modified gravity, which is regarded as a parity-odd theory of massive gravity in four dimensions. We first find polarization modes of gravitational waves for θ=x/μ in nCS modified gravity by using the Newman-Penrose formalism where the null complex tetrad is necessary to specify gravitational waves. We show that in the Newman–Penrose formalism, the number of polarization modes is one in addition to an unspecified Ψ{sub 4}, implying three degrees of freedom for θ=x/μ. This compares with two for a canonical embedding of θ=t/μ. Also, if one introduces the Ricci tensor formalism to describe a massive graviton arising from the nCS modified gravity, one finds one massive mode after making second-order wave equations, which is compared to five found from the parity-even Einstein–Weyl gravity.
Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2002...
Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove...
Ground Gravity Survey At Hot Pot Area (DOE GTP) | Open Energy...
Ground Gravity Survey At Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Hot Pot Area (DOE GTP)...
Ground Gravity Survey At Fort Bliss Area (DOE GTP) | Open Energy...
Ground Gravity Survey At Fort Bliss Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Fort Bliss Area (DOE...
Ground Gravity Survey At New River Area (DOE GTP) | Open Energy...
Ground Gravity Survey At New River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At New River Area (DOE...
Ground Gravity Survey At Glass Buttes Area (DOE GTP) | Open Energy...
Ground Gravity Survey At Glass Buttes Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Glass Buttes Area...
Mixing lengths scaling in a gravity flow
Ecke, Robert E [Los Alamos National Laboratory; Rivera, Micheal [Los Alamos National Laboratory; Chen, Jun [Los Alamos National Laboratory; Ecke, Robert E [Los Alamos National Laboratory
2009-01-01
We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model [1]: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadraticatly with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing length, approximately constant over the mixing zone of the stratified shear layer. We show in this paper how, in different flow configurations, this length can be related to the shear length of the flow {radical}({var_epsilon}/{partial_derivative}{sub z}u{sup 3}).
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
Percentages of Total Imported Crude by API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
API Gravity Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes
Perihelion precession for modified Newtonian gravity
Schmidt, Hans-Juergen
2008-07-15
We calculate the perihelion precession {delta} for nearly circular orbits in a central potential V(r). Differently from other approaches to this problem, we do not assume that the potential is close to the Newtonian one. The main idea in the deduction is to apply the underlying symmetries of the system to show that {delta} must be a function of r{center_dot}V{sup ''}(r)/V{sup '}(r) and to use the transformation behavior of {delta} in a rotating system of reference. This is equivalent to say that the effective potential can be written in a one-parameter set of possibilities as the sum of centrifugal potential and potential of the central force. We get the following universal formula valid for V{sup '}(r)>0 reading {delta}(r)=2{pi}{center_dot}[(1/{radical}(3+r{center_dot}V{sup ''}(r)/V{sup '}(r)))-1]. It has to be read as follows: a circular orbit at this value r exists and is stable if and only if this {delta} is well-defined as real; and if this is the case, then the angular difference from one perihelion to the next one for nearly circular orbits at this r is exactly 2{pi}+{delta}(r). Then we apply this result to examples of recent interest like modified Newtonian gravity and linearized fourth-order gravity. In the second part of the paper, we generalize this universal formula to static spherically symmetric space-times ds{sup 2}=-e{sup 2{lambda}}{sup (r)}dt{sup 2}+e{sup 2{mu}}{sup (r)}dr{sup 2}+r{sup 2}d{omega}{sup 2}; for orbits near r it reads {delta}=2{pi}{center_dot}[(e{sup {mu}}{sup (r)}/{radical}(3-2r{center_dot}{lambda}{sup '}(r)+r{center_dot}{lambda}{sup ''}(r)/{lambda}{sup '}(r)))-1] and can be applied to a large class of theories. For the Schwarzschild black hole with mass parameter m>0 it leads to {delta}=2{pi}{center_dot}[(1/{radical}(1-(6m/r)))-1], a surprisingly unknown formula. It represents a strict result and is applicable for all values r>6m and is in good agreement with the fact that stable circular orbits exist for r>6m only. For r>>m, one can develop in powers of m and get the well-known approximation {delta}{approx_equal}(6{pi}m/r)
Ionospheric acoustic and gravity waves associated with midlatitude thunderstorms
Lay, Erin H.; Shao, Xuan -Min; Kendrick, Alexander K.; Carrano, Charles S.
2015-07-30
Acoustic waves with periods of 24 min and gravity waves with periods of 616 min have been detected at ionospheric heights (25350 km) using GPS total electron content measurements. The area disturbed by these waves and the wave amplitudes have been associated with underlying thunderstorm activity. A statistical study comparing Next Generation Weather Radar thunderstorm measurements with ionospheric acoustic and gravity waves in the midlatitude U.S. Great Plains region was performed for the time period of MayJuly 2005. An increase of ionospheric acoustic wave disturbed area and amplitude is primarily associated with large thunderstorms (mesoscale convective systems). Ionospheric gravity wave disturbed area and amplitude scale with thunderstorm activity, with even small storms (i.e., individual storm cells) producing an increase of gravity waves.
Ground Gravity Survey At Dixie Valley Geothermal Area (Iovenitti...
project area. These data were used in conjunction with past gravity data reported in by Smith et al (2001) and Blackwell et al (2005). The analysis of these data had not been...
Ground Gravity Survey At Truckhaven Area (Layman Energy Associates...
9. The 95 magnetotelluric (MT) soundings cover a central area of about 80 square kilometers. The 126 gravity stations extend over a broader area of about 150 square kilometers,...
Geologic interpretation of gravity and magnetic data in the Salida...
interpretation of gravity and magnetic data in the Salida region, Colorado Authors J.E. Case and R.F. Sikora Published U.S. Geological Survey Open-File Report, 1984 Report...
Ground Gravity Survey At Mt Princeton Hot Springs Geothermal...
lithologic distrubtions Notes Gravity low associated with Mt. Princeton Batholith; density contrast of -0.5 gcm3 of valley-fill sediments relative to batholith References J.E....
Ionospheric acoustic and gravity waves associated with midlatitude thunderstorms
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lay, Erin H.; Shao, Xuan -Min; Kendrick, Alexander K.; Carrano, Charles S.
2015-07-30
Acoustic waves with periods of 2–4 min and gravity waves with periods of 6–16 min have been detected at ionospheric heights (25–350 km) using GPS total electron content measurements. The area disturbed by these waves and the wave amplitudes have been associated with underlying thunderstorm activity. A statistical study comparing Next Generation Weather Radar thunderstorm measurements with ionospheric acoustic and gravity waves in the midlatitude U.S. Great Plains region was performed for the time period of May–July 2005. An increase of ionospheric acoustic wave disturbed area and amplitude is primarily associated with large thunderstorms (mesoscale convective systems). Ionospheric gravity wavemore » disturbed area and amplitude scale with thunderstorm activity, with even small storms (i.e., individual storm cells) producing an increase of gravity waves.« less
Ground Gravity Survey At Neal Hot Springs Geothermal Area (U...
survey was completed by MWH Geo-Surveys. Interpretations were made by creating a 3D density inversion map. Gravity and magnetic data were used in siting the first production...
Ground Gravity Survey At Dixie Valley Geothermal Area (Blackwell...
local studies conducted in the past. Gravity data measured in the 1970's by Hunt Oil, Sun Oil, and Southland royalty (all unpublished reports) ware used. These data were combined...
Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...
Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....
Regional Gravity Survey of the Northern Great Salt Lake Desert...
of about -196 mgal over the alluvium-covered graben areas. The gravity high over the Raft River Mountains apparently corresponds with the Raft River Mountains anticline. A belt...
Cosmological stability bound in massive gravity and bigravity
Fasiello, Matteo; Tolley, Andrew J. E-mail: andrew.j.tolley@case.edu
2013-12-01
We give a simple derivation of a cosmological bound on the graviton mass for spatially flat FRW solutions in massive gravity with an FRW reference metric and for bigravity theories. This bound comes from the requirement that the kinetic term of the helicity zero mode of the graviton is positive definite. The bound is dependent only on the parameters in the massive gravity potential and the Hubble expansion rate for the two metrics. We derive the decoupling limit of bigravity and FRW massive gravity, and use this to give an independent derivation of the cosmological bound. We recover our previous results that the tension between satisfying the Friedmann equation and the cosmological bound is sufficient to rule out all observationally relevant FRW solutions for massive gravity with an FRW reference metric. In contrast, in bigravity this tension is resolved due to different nature of the Vainshtein mechanism. We find that in bigravity theories there exists an FRW solution with late-time self-acceleration for which the kinetic terms for the helicity-2, helicity-1 and helicity-0 are generically nonzero and positive making this a compelling candidate for a model of cosmic acceleration. We confirm that the generalized bound is saturated for the candidate partially massless (bi)gravity theories but the existence of helicity-1/helicity-0 interactions implies the absence of the conjectured partially massless symmetry for both massive gravity and bigravity.
Finite field-dependent symmetries in perturbative quantum gravity
Upadhyay, Sudhaker
2014-01-15
In this paper we discuss the absolutely anticommuting nilpotent symmetries for perturbative quantum gravity in general curved spacetime in linear and non-linear gauges. Further, we analyze the finite field-dependent BRST (FFBRST) transformation for perturbative quantum gravity in general curved spacetime. The FFBRST transformation changes the gauge-fixing and ghost parts of the perturbative quantum gravity within functional integration. However, the operation of such symmetry transformation on the generating functional of perturbative quantum gravity does not affect the theory on physical ground. The FFBRST transformation with appropriate choices of finite BRST parameter connects non-linear CurciFerrari and Landau gauges of perturbative quantum gravity. The validity of the results is also established at quantum level using BatalinVilkovisky (BV) formulation. -- Highlights: The perturbative quantum gravity is treated as gauge theory. BRST and anti-BRST transformations are developed in linear and non-linear gauges. BRST transformation is generalized by making it finite and field dependent. Connection between linear and non-linear gauges is established. Using BV formulation the results are established at quantum level also.
TESTING ALTERNATIVE THEORIES OF GRAVITY USING THE SUN
Casanellas, Jordi; Pani, Paolo; Lopes, Ilidio; Cardoso, Vitor E-mail: paolo.pani@ist.utl.pt E-mail: vitor.cardoso@ist.utl.pt
2012-01-20
We propose a new approach to test possible corrections to Newtonian gravity using solar physics. The high accuracy of current solar models and new precise observations allow us to constrain corrections to standard gravity at unprecedented levels. Our case study is Eddington-inspired gravity, an attractive modified theory of gravity which results in non-singular cosmology and collapse. The theory is equivalent to standard gravity in vacuum, but it sensibly differs from it within matter. For instance, it affects the evolution and the equilibrium structure of the Sun, giving different core temperature profiles, and deviations in the observed acoustic modes and in solar neutrino fluxes. Comparing the predictions from a modified solar model with observations, we constrain the coupling parameter of the theory, |{kappa}{sub g}| {approx}< 3 Multiplication-Sign 10{sup 5} m{sup 5} s{sup -2} kg{sup -1}. Our results show that the Sun can be used to efficiently constrain alternative theories of gravity.
Angular momentum transport via internal gravity waves in evolving stars
Fuller, Jim; Lecoanet, Daniel; Cantiello, Matteo; Brown, Ben
2014-11-20
Recent asteroseismic advances have allowed for direct measurements of the internal rotation rates of many subgiant and red giant stars. Unlike the nearly rigidly rotating Sun, these evolved stars contain radiative cores that spin faster than their overlying convective envelopes, but slower than they would in the absence of internal angular momentum transport. We investigate the role of internal gravity waves in angular momentum transport in evolving low-mass stars. In agreement with previous results, we find that convectively excited gravity waves can prevent the development of strong differential rotation in the radiative cores of Sun-like stars. As stars evolve into subgiants, however, low-frequency gravity waves become strongly attenuated and cannot propagate below the hydrogen-burning shell, allowing the spin of the core to decouple from the convective envelope. This decoupling occurs at the base of the subgiant branch when stars have surface temperatures of T ? 5500 K. However, gravity waves can still spin down the upper radiative region, implying that the observed differential rotation is likely confined to the deep core near the hydrogen-burning shell. The torque on the upper radiative region may also prevent the core from accreting high angular momentum material and slow the rate of core spin-up. The observed spin-down of cores on the red giant branch cannot be totally attributed to gravity waves, but the waves may enhance shear within the radiative region and thus increase the efficacy of viscous/magnetic torques.
First tsunami gravity wave detection in ionospheric radio occultation data
Cosson, Pierdavide; Lognonn, Philippe; Walwer, Damian; Rolland, Lucie M.
2015-05-09
After the 11 March 2011 earthquake and tsunami off the coast of Tohoku, the ionospheric signature of the displacements induced in the overlying atmosphere has been observed by ground stations in various regions of the Pacific Ocean. We analyze here the data of radio occultation satellites, detecting the tsunami-driven gravity wave for the first time using a fully space-based ionospheric observation system. One satellite of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) recorded an occultation in the region above the tsunami 2.5 h after the earthquake. The ionosphere was sounded from top to bottom, thus providing the vertical structure of the gravity wave excited by the tsunami propagation, observed as oscillations of the ionospheric Total Electron Content (TEC). The observed vertical wavelength was about 50 km, with maximum amplitude exceeding 1 total electron content unit when the occultation reached 200 km height. We compared the observations with synthetic data obtained by summation of the tsunami-coupled gravity normal modes of the Earth/Ocean/atmosphere system, which models the associated motion of the ionosphere plasma. These results provide experimental constraints on the attenuation of the gravity wave with altitude due to atmosphere viscosity, improving the understanding of the propagation of tsunami-driven gravity waves in the upper atmosphere. They demonstrate that the amplitude of the tsunami can be estimated to within 20% by the recorded ionospheric data.
Correlation between precision gravity and subsidence measurements at Cerro Prieto
Zelwer, R.; Grannell, R.B.
1982-10-01
Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years. Minor subsidence and small related gravity changes for the period preceeding the Victoria earthquake suggest that in spite of large fluid production rates, the reservoir is being almost completely recharged and that a measurable increase in subsurface density may be taking place. The results of measurements of horizontal ground motions made in this area are discussed in relation to the gravity and subsidence observations.
First tsunami gravity wave detection in ionospheric radio occultation data
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Coïsson, Pierdavide; Lognonné, Philippe; Walwer, Damian; Rolland, Lucie M.
2015-05-09
After the 11 March 2011 earthquake and tsunami off the coast of Tohoku, the ionospheric signature of the displacements induced in the overlying atmosphere has been observed by ground stations in various regions of the Pacific Ocean. We analyze here the data of radio occultation satellites, detecting the tsunami-driven gravity wave for the first time using a fully space-based ionospheric observation system. One satellite of the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) recorded an occultation in the region above the tsunami 2.5 h after the earthquake. The ionosphere was sounded from top to bottom, thus providing themore » vertical structure of the gravity wave excited by the tsunami propagation, observed as oscillations of the ionospheric Total Electron Content (TEC). The observed vertical wavelength was about 50 km, with maximum amplitude exceeding 1 total electron content unit when the occultation reached 200 km height. We compared the observations with synthetic data obtained by summation of the tsunami-coupled gravity normal modes of the Earth/Ocean/atmosphere system, which models the associated motion of the ionosphere plasma. These results provide experimental constraints on the attenuation of the gravity wave with altitude due to atmosphere viscosity, improving the understanding of the propagation of tsunami-driven gravity waves in the upper atmosphere. They demonstrate that the amplitude of the tsunami can be estimated to within 20% by the recorded ionospheric data.« less
On the null trajectories in conformal Weyl gravity
Villanueva, J.R.; Olivares, Marco E-mail: marco.olivaresrubilar@gmail.com
2013-06-01
In this work we find analytical solutions to the null geodesics around a black hole in the conformal Weyl gravity. Exact expressions for the horizons are found, and they depend on the cosmological constant and the coupling constants of the conformal Weyl gravity. Then, we study the radial motion from the point of view of the proper and coordinate frames, and compare it with that found in spacetimes of general relativity. The angular motion is also examined qualitatively by means of an effective potential; quantitatively, the equation of motion is solved in terms of wp-Weierstrass elliptic function. Thus, we find the deflection angle for photons without using any approximation, which is a novel result for this kind of gravity.
Monitoring the Bulalo geothermal reservoir, Philippines, using precision gravity data
San Andres, R.B.; Pedersen, J.R.
1993-10-01
Precision gravity monitoring of the Bulalo geothermal field began in 1980 to estimate the natural mass recharge to the reservoir. Between 1980 and 1991, gravity decreases exceeding 2.5 {times} 10{sup {minus}6} N/kg (250 microgals) were observed in response to fluid withdrawals. A maximum rate of {minus}26 microgals per year was observed near the production center. Mass discharges predicted by recent reservoir simulation modeling generally match those inferred from the observed gravity data. According to simulation studies, no recharge occurred between 1980 and 1984. The mass recharge between 1984 and 1991 was estimated to be 30% of net fluid withdrawal during the same period, equivalent to an average rate of 175 kg/s (630 metric tons per hour).
Spectral regularisation: induced gravity and the onset of inflation
Kurkov, Max A.; Sakellariadou, Mairi E-mail: mairi.sakellariadou@kcl.ac.uk
2014-01-01
Using spectral regularisation, we compute the Weyl anomaly and express the anomaly generating functional of the quantum effective action through a collective scalar degree of freedom of all quantum vacuum fluctuations. Such a formulation allows us to describe induced gravity on an equal footing with the anomaly-induced effective action, in a self-consistent way. We then show that requiring stability of the cosmological constant under loop quantum corrections, Sakharov's induced gravity and Starobinsky's anomaly-induced inflation are either both present or both absent, depending on the particle content of the theory.
Minimum length, extra dimensions, modified gravity and black hole remnants
Maziashvili, Michael
2013-03-01
We construct a Hilbert space representation of minimum-length deformed uncertainty relation in presence of extra dimensions. Following this construction, we study corrections to the gravitational potential (back reaction on gravity) with the use of correspondingly modified propagator in presence of two (spatial) extra dimensions. Interestingly enough, for r?0 the gravitational force approaches zero and the horizon for modified Schwarzschild-Tangherlini space-time disappears when the mass approaches quantum-gravity energy scale. This result points out to the existence of zero-temperature black hole remnants in ADD brane-world model.
Stabilization of linear higher derivative gravity with constraints
Chen, Tai-jun; Lim, Eugene A. E-mail: eugene.a.lim@gmail.com
2014-05-01
We show that the instabilities of higher derivative gravity models with quadratic curvature invariant ?R{sup 2}+?R{sub ??}R{sup ??} can be removed by judicious addition of constraints at the quadratic level of metric fluctuations around Minkowski/de Sitter background. With a suitable parameter choice, we find that the instabilities of helicity-0, 1, 2 modes can be removed while reducing the dimensionality of the original phase space. To retain the renormalization properties of higher derivative gravity, Lorentz symmetry in the constrained theory is explicitly broken.
Spherically symmetric static spacetimes in vacuum f(T) gravity
Ferraro, Rafael; Fiorini, Franco
2011-10-15
We show that Schwarzschild geometry remains as a vacuum solution for those four-dimensional f(T) gravitational theories behaving as ultraviolet deformations of general relativity. In the gentler context of three-dimensional gravity, we also find that the infrared-deformed f(T) gravities, like the ones used to describe the late cosmic speed up of the Universe, have as the circularly symmetric vacuum solution a Deser-de Sitter or a Banados, Teitelboim and Zanelli-like spacetime with an effective cosmological constant depending on the infrared scale present in the function f(T).
Gravitomagnetic gyroscope precession in Palatini f(R) gravity
Ruggiero, Matteo Luca
2009-04-15
We study gravitomagnetic effects in the Palatini formalism of f(R) gravity. On using the Kerr-de Sitter metric, which is a solution of f(R) field equations, we calculate the impact of f(R) gravity on the gravitomagnetic precession of an orbiting gyroscope. We show that, even though an f(R) contribution is present in principle, its magnitude is negligibly small and far to be detectable in the present (like GP-B) and foreseeable space missions or observational tests around the Earth.
Gravity Survey of the Carson Sink - Data and Maps
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Faulds, James E.
Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south?central, east?central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step?overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.
Gravity Survey of the Carson Sink - Data and Maps
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Faulds, James E.
2013-12-31
Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south?central, east?central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step?overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.
Flat 3-brane with Tension in Cascading Gravity
Rham, Claudia de; Khoury, Justin; Tolley, Andrew
2009-10-16
In the cascading gravity brane-world scenario, our 3-brane lies within a succession of lower-codimension branes, each with their own induced gravity term, embedded into each other in a higher-dimensional space-time. In the (6+1)-dimensional version of this scenario, we show that a 3-brane with tension remains flat, at least for sufficiently small tension that the weak-field approximation is valid. The bulk solution is singular nowhere and remains in the perturbative regime everywhere.
On the gauge features of gravity on a Lie algebroid structure
Fabi, S. Harms, B. Hou, S.
2014-03-15
We present the geometric formulation of gravity based on the mathematical structure of a Lie Algebroid. We show that this framework provides the geometrical setting to describe the gauge propriety of gravity.
Problems with propagation and time evolution inf(T)gravity (Journal...
Office of Scientific and Technical Information (OSTI)
Problems with propagation and time evolution inf(T)gravity Citation Details In-Document Search Title: Problems with propagation and time evolution inf(T)gravity Authors: Ong, Yen...
Toward large N thermal QCD from dual gravity: The heavy quarkonium...
Office of Scientific and Technical Information (OSTI)
We continue our study on the gravity duals for strongly coupled large N QCD with fundamental flavors both at zero and nonzero temperatures. The gravity dual at zero temperature ...
Toward large N thermal QCD from dual gravity: The heavy quarkonium
Office of Scientific and Technical Information (OSTI)
potential (Journal Article) | SciTech Connect Toward large N thermal QCD from dual gravity: The heavy quarkonium potential Citation Details In-Document Search Title: Toward large N thermal QCD from dual gravity: The heavy quarkonium potential We continue our study on the gravity duals for strongly coupled large N QCD with fundamental flavors both at zero and nonzero temperatures. The gravity dual at zero temperature captures the logarithmic runnings of the coupling constants at far IR and
Complete Bouguer gravity map of the Nevada Test Site and vicinity, Nevada
Healey, D.L.; Harris, R.N.; Ponce, D.A.; Oliver, H.W.
1987-12-31
About 15,000 gravity stations were used to create the gravity map. Gravity studies at the Nevada Test Site were undertaken to help locate geologically favorable areas for underground nuclear tests and to help characterize potential high-level nuclear waste storage sites. 48 refs. (TEM)
Entirely passive heat pipe apparatus capable of operating against gravity
Koenig, Daniel R. (Santa Fe, NM)
1982-01-01
The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 meters and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.
Further stable neutron star models from f(R) gravity
Astashenok, Artyom V.; Capozziello, Salvatore; Odintsov, Sergei D. E-mail: capozziello@na.infn.it
2013-12-01
Neutron star models in perturbative f(R) gravity are considered with realistic equations of state. In particular, we consider the FPS, SLy and other equations of state and a case of piecewise equation of state for stars with quark cores. The mass-radius relations for f(R) = R+R(e{sup ?R/R{sub 0}}?1) model and for R{sup 2} models with logarithmic and cubic corrections are obtained. In the case of R{sup 2} gravity with cubic corrections, we obtain that at high central densities (? > 10?{sub ns}, where ?{sub ns} = 2.7 10{sup 14} g/cm{sup 3} is the nuclear saturation density), stable star configurations exist. The minimal radius of such stars is close to 9 km with maximal mass ? 1.9M{sub ?} (SLy equation). A similar situation takes place for AP4 and BSK20 EoS. Such an effect can give rise to more compact stars than in General Relativity. If observationally identified, such objects could constitute a formidable signature for modified gravity at astrophysical level. Another interesting result can be achieved in modified gravity with only a cubic correction. For some EoS, the upper limit of neutron star mass increases and therefore these EoS can describe realistic star configurations (although, in General Relativity, these EoS are excluded by observational constraints)
Extreme neutron stars from Extended Theories of Gravity
Astashenok, Artyom V.; Capozziello, Salvatore; Odintsov, Sergei D. E-mail: capozziello@na.infn.it
2015-01-01
We discuss neutron stars with strong magnetic mean fields in the framework of Extended Theories of Gravity. In particular, we take into account models derived from f(R) and f(G) extensions of General Relativity where functions of the Ricci curvature invariant R and the Gauss-Bonnet invariant G are respectively considered. Dense matter in magnetic mean field, generated by magnetic properties of particles, is described by assuming a model with three meson fields and baryons octet. As result, the considerable increasing of maximal mass of neutron stars can be achieved by cubic corrections in f(R) gravity. In principle, massive stars with M>4M{sub ?} can be obtained. On the other hand, stable stars with high strangeness fraction (with central densities ?{sub c}?1.52.0 GeV/fm{sup 3}) are possible considering quadratic corrections of f(G) gravity. The magnetic field strength in the star center is of order 68נ10{sup 18} G. In general, we can say that other branches of massive neutron stars are possible considering the extra pressure contributions coming from gravity extensions. Such a feature can constitute both a probe for alternative theories and a way out to address anomalous self-gravitating compact systems.
On singularities of capillary surfaces in the absence of gravity
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Roytburd, V.
1983-01-01
We study numerical solutions to the equation of capillary surfaces in trapezoidal domains in the absence of gravity when the boundary contact angle declines from 90 to some critical value. We also discuss a result on the behavior of solutions in more general domains that confirms numerical calculations.
Cartan gravity, matter fields, and the gauge principle
Westman, Hans F.; Zlosnik, Tom G.
2013-07-15
Gravity is commonly thought of as one of the four force fields in nature. However, in standard formulations its mathematical structure is rather different from the YangMills fields of particle physics that govern the electromagnetic, weak, and strong interactions. This paper explores this dissonance with particular focus on how gravity couples to matter from the perspective of the Cartan-geometric formulation of gravity. There the gravitational field is represented by a pair of variables: (1) a contact vector V{sup A} which is geometrically visualized as the contact point between the spacetime manifold and a model spacetime being rolled on top of it, and (2) a gauge connection A{sub ?}{sup AB}, here taken to be valued in the Lie algebra of SO(2,3) or SO(1,4), which mathematically determines how much the model spacetime is rotated when rolled. By insisting on two principles, the gauge principle and polynomial simplicity, we shall show how one can reformulate matter field actions in a way that is harmonious with Cartans geometric construction. This yields a formulation of all matter fields in terms of first order partial differential equations. We show in detail how the standard second order formulation can be recovered. In particular, the Hodge dual, which characterizes the structure of bosonic field equations, pops up automatically. Furthermore, the energymomentum and spin-density three-forms are naturally combined into a single object here denoted the spin-energymomentum three-form. Finally, we highlight a peculiarity in the mathematical structure of our first-order formulation of YangMills fields. This suggests a way to unify a U(1) gauge field with gravity into a SO(1,5)-valued gauge field using a natural generalization of Cartan geometry in which the larger symmetry group is spontaneously broken down to SO(1,3)U(1). The coupling of this unified theory to matter fields and possible extensions to non-Abelian gauge fields are left as open questions. -- Highlights: Develops Cartan gravity to include matter fields. Coupling to gravity is done using the standard gauge prescription. Matter actions are manifestly polynomial in all field variables. Standard equations recovered on-shell for scalar, spinor and YangMills fields. Unification of a U(1) field with gravity based on the orthogonal group SO(1,5)
Gravity monitoring of CO2 movement during sequestration: Model studies
Gasperikova, E.; Hoversten, G.M.
2008-07-15
We examine the relative merits of gravity measurements as a monitoring tool for geological CO{sub 2} sequestration in three different modeling scenarios. The first is a combined CO{sub 2} enhanced oil recovery (EOR) and sequestration in a producing oil field, the second is sequestration in a brine formation, and the third is for a coalbed methane formation. EOR/sequestration petroleum reservoirs have relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and CO{sub 2}), whereas brine formations usually have much thicker injection intervals and only two components (brine and CO{sub 2}). Coal formations undergoing methane extraction tend to be thin (3-10 m), but shallow compared to either EOR or brine formations. The injection of CO{sub 2} into the oil reservoir produced a bulk density decrease in the reservoir. The spatial pattern of the change in the vertical component of gravity (G{sub z}) is directly correlated with the net change in reservoir density. Furthermore, time-lapse changes in the borehole G{sub z} clearly identified the vertical section of the reservoir where fluid saturations are changing. The CO{sub 2}-brine front, on the order of 1 km within a 20 m thick brine formation at 1900 m depth, with 30% CO{sub 2} and 70% brine saturations, respectively, produced a -10 Gal surface gravity anomaly. Such anomaly would be detectable in the field. The amount of CO{sub 2} in a coalbed methane test scenario did not produce a large enough surface gravity response; however, we would expect that for an industrial size injection, the surface gravity response would be measurable. Gravity inversions in all three scenarios illustrated that the general position of density changes caused by CO{sub 2} can be recovered, but not the absolute value of the change. Analysis of the spatial resolution and detectability limits shows that gravity measurements could, under certain circumstances, be used as a lower-cost alternative to seismic measurements.
Multi-gravity separator: an alternate gravity concentrator to process coal fines
Majumder, A.K.; Bhoi, K.S.; Barnwal, J.P.
2007-08-15
The multi-gravity separator (MGS) is a novel piece of equipment for the separation of fine and ultra-fine minerals. However, the published literature does not demonstrate its use in the separation of coal fines. Therefore, an attempt was made to study the effects of different process variables on the performance of an MGS for the beneficiation of coal fines. The results obtained from this study revealed that among the parameters studied, drum rotation and feed solids concentration play dominating roles in controlling the yield and ash content of the clean coal. Mathematical modeling equations that correlate the variables studied and the yield and ash contents of the clean coal were developed to predict the performance of an MGS under different operating and design conditions. The entire exercise revealed that the MGS could produce a clean coal with an ash content of 14.67% and a yield of 71.23% from a feed coal having an ash content of 24.61 %.
Energy Science and Technology Software Center (OSTI)
2014-12-04
The software serves two purposes. The first purpose of the software is to prototype the Sandia High Performance Computing Power Application Programming Interface Specification effort. The specification can be found at http://powerapi.sandia.gov . Prototypes of the specification were developed in parallel with the development of the specification. Release of the prototype will be instructive to anyone who intends to implement the specification. More specifically, our vendor collaborators will benefit from the availability of the prototype.more » The second is in direct support of the PowerInsight power measurement device, which was co-developed with Penguin Computing. The software provides a cluster wide measurement capability enabled by the PowerInsight device. The software can be used by anyone who purchases a PowerInsight device. The software will allow the user to easily collect power and energy information of a node that is instrumented with PowerInsight. The software can also be used as an example prototype implementation of the High Performance Computing Power Application Programming Interface Specification.« less
IDs to work on Separate values with '|' Maximum number of values 50 (500 for bots) prop - Which properties to get for the titlesrevisionspageids. Module help is available...
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
Glossary API Gravity: An arbitrary scale expressing the gravity or density of liquid petroleum products. The measur- ing scale is calibrated in terms of degrees API; it may be calculated in terms of the following formula: Deg API sp gr degF degF = - 1415 60 60 1315 . . The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below. Intermediate crudes fall in the
Table Definitions, Sources, and Explanatory Notes
Gasoline and Diesel Fuel Update (EIA)
Qualities of Crude Oil Input Definitions Key Terms Definition API Gravity An arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API; it is calculated as follows: Degrees API = (141.5 / (sp. gr. 60ºF / 60ºF)) - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed 38 degrees API and heavy crudes are commonly labeled as all crudes with an API gravity of 22 degrees or below.
Infrared lessons for ultraviolet gravity: the case of massive gravity and Born-Infeld
Jimnez, Jose Beltrn; Heisenberg, Lavinia; Olmo, Gonzalo J. E-mail: Lavinia.Heisenberg@unige.ch
2014-11-01
We generalize the ultraviolet sector of gravitation via a Born-Infeld action using lessons from massive gravity. The theory contains all of the elementary symmetric polynomials and is treated in the Palatini formalism. We show how the connection can be solved algebraically to be the Levi-Civita connection of an effective metric. The non-linearity of the algebraic equations yields several branches, one of which always reduces to General Relativity at low curvatures. We explore in detail a minimal version of the theory, for which we study solutions in the presence of a perfect fluid with special attention to the cosmological evolution. In vacuum we recover Ricci-flat solutions, but also an additional physical solution corresponding to an Einstein space. The existence of two physical branches remains for non-vacuum solutions and, in addition, the branch that connects to the Einstein space in vacuum is not very sensitive to the specific value of the energy density. For the branch that connects to the General Relativity limit we generically find three behaviours for the Hubble function depending on the equation of state of the fluid, namely: either there is a maximum value for the energy density that connects continuously with vacuum, or the energy density can be arbitrarily large but the Hubble function saturates and remains constant at high energy densities, or the energy density is unbounded and the Hubble function grows faster than in General Relativity. The second case is particularly interesting because it could offer an interesting inflationary epoch even in the presence of a dust component. Finally, we discuss the possibility of avoiding certain types of singularities within the minimal model.
Translation invariant time-dependent solutions to massive gravity
Mourad, J.; Steer, D.A. E-mail: steer@apc.univ-paris7.fr
2013-12-01
Homogeneous time-dependent solutions of massive gravity generalise the plane wave solutions of the linearised Fierz-Pauli equations for a massive spin-two particle, as well as the Kasner solutions of General Relativity. We show that they also allow a clear counting of the degrees of freedom and represent a simplified framework to work out the constraints, the equations of motion and the initial value formulation. We work in the vielbein formulation of massive gravity, find the phase space resulting from the constraints and show that several disconnected sectors of solutions exist some of which are unstable. The initial values determine the sector to which a solution belongs. Classically, the theory is not pathological but quantum mechanically the theory may suffer from instabilities. The latter are not due to an extra ghost-like degree of freedom.
Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames
Chakrabarty, Rajan K.; Novosselov, Igor V.; Beres, Nicholas D.; Moosmller, Hans; Sorensen, Christopher M.; Stipe, Christopher B.
2014-06-16
We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (?g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in ?g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in ?g flames, which reduces the time to gel for nanoparticles by ?10{sup 6}?s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.
Cosmological perturbations in non-local higher-derivative gravity
Craps, Ben; Jonckheere, Tim De; Koshelev, Alexey S. E-mail: Tim.De.Jonckheere@vub.ac.be
2014-11-01
We study cosmological perturbations in a non-local higher-derivative model of gravity introduced by Biswas, Mazumdar and Siegel. We extend previous work, which had focused on classical scalar perturbations around a cosine hyperbolic bounce solution, in three ways. First, we point out the existence of a Starobinsky solution in this model, which is more attractive from a phenomenological point of view (even though it has no bounce). Second, we study classical vector and tensor pertuxsxrbations. Third, we show how to quantize scalar and tensor perturbations in a de Sitter phase (for choices of parameters such that the model is ghost-free). Our results show that the model is well-behaved at this level, and are very similar to corresponding results in local f(R) models. In particular, for the Starobinsky solution of non-local higher-derivative gravity, we find the same tensor-to-scalar ratio as for the conventional Starobinsky model.
Constraints on axion inflation from the weak gravity conjecture
Rudelius, Tom
2015-09-08
We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C{sub 4} axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C{sub 4} axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.
Structure formation in a nonlocally modified gravity model
Park, Sohyun; Dodelson, Scott
2013-01-01
We study a nonlocally modified gravity model proposed by Deser and Woodard which gives an explanation for current cosmic acceleration. By deriving and solving the equations governing the evolution of the structure in the Universe, we show that this model predicts a pattern of growth that differs from standard general relativity (+dark energy) at the 10-30% level. These differences will be easily probed by the next generation of galaxy surveys, so the model should be tested shortly.
Quantum Gravity corrections and entropy at the Planck time
Basilakos, Spyros; Vagenas, Elias C.; Das, Saurya E-mail: saurya.das@uleth.ca
2010-09-01
We investigate the effects of Quantum Gravity on the Planck era of the universe. In particular, using different versions of the Generalized Uncertainty Principle and under specific conditions we find that the main Planck quantities such as the Planck time, length, mass and energy become larger by a factor of order 10?10{sup 4} compared to those quantities which result from the Heisenberg Uncertainty Principle. However, we prove that the dimensionless entropy enclosed in the cosmological horizon at the Planck time remains unchanged. These results, though preliminary, indicate that we should anticipate modifications in the set-up of cosmology since changes in the Planck era will be inherited even to the late universe through the framework of Quantum Gravity (or Quantum Field Theory) which utilizes the Planck scale as a fundamental one. More importantly, these corrections will not affect the entropic content of the universe at the Planck time which is a crucial element for one of the basic principles of Quantum Gravity named Holographic Principle.
The observational status of Galileon gravity after Planck
Barreira, Alexandre; Li, Baojiu; Baugh, Carlton M.; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: silvia.pascoli@durham.ac.uk
2014-08-01
We use the latest CMB data from Planck, together with BAO measurements, to constrain the full parameter space of Galileon gravity. We constrain separately the three main branches of the theory known as the Cubic, Quartic and Quintic models, and find that all yield a very good fit to these data. Unlike in ?CDM, the Galileon model constraints are compatible with local determinations of the Hubble parameter and predict nonzero neutrino masses at over 5? significance. We also identify that the low l part of the CMB lensing spectrum may be able to distinguish between ?CDM and Galileon models. In the Cubic model, the lensing potential deepens at late times on sub-horizon scales, which is at odds with the current observational suggestion of a positive ISW effect. Compared to ?CDM, the Quartic and Quintic models predict less ISW power in the low l region of the CMB temperature spectrum, and as such are slightly preferred by the Planck data. We illustrate that residual local modifications to gravity in the Quartic and Quintic models may render the Cubic model as the only branch of Galileon gravity that passes Solar System tests.
Cosmological perturbation in f(T) gravity revisited
Izumi, Keisuke; Ong, Yen Chin E-mail: ongyenchin@member.ams.org
2013-06-01
We perform detailed investigation of cosmological perturbations in f(T) theory of gravity coupled with scalar field. Our work emphasizes on the way to gauge fix the theory and we examine all possible modes of perturbations up to second order. The analysis includes pseudoscalar and pseudovector modes in addition to the usual scalar, vector, and tensor modes. We find no gravitational propagating degree of freedom in the scalar, pseudoscalar, vector, as well as pseudovector modes. In addition, we find that the scalar and tensor perturbations have exactly the same form as their counterparts in usual general relativity with scalar field, except that the factor of reduced Planck mass squared M{sub pl}{sup 2}?1/(8?G) that occurs in the latter has now been replaced by an effective time-dependent gravitational coupling ?2(df/dT)|{sub T=T{sub 0}}, with T{sub 0} being the background torsion scalar. The absence of extra degrees of freedom of f(T) gravity at second order linear perturbation indicates that f(T) gravity is highly nonlinear. Consequently one cannot conclusively analyze stability of the theory without performing nonlinear analysis that can reveal the propagation of the extra degrees of freedom.
Disformal theories of gravity: from the solar system to cosmology
Sakstein, Jeremy
2014-12-01
This paper is concerned with theories of gravity that contain a scalar coupled both conformally and disformally to matter through the metric. By systematically deriving the non-relativistic limit, it is shown that no new non-linear screening mechanisms are present beyond the Vainshtein mechanism and chameleon-like screening. If one includes the cosmological expansion of the universe, disformal effects that are usually taken to be absent can be present in the solar system. When the conformal factor is absent, fifth-forces can be screened on all scales when the cosmological field is slowly-rolling. We investigate the cosmology of these models and use local tests of gravity to place new constraints on the disformal coupling and find M?>O(eV), which is not competitive with laboratory tests. Finally, we discuss the future prospects for testing these theories and the implications for other theories of modified gravity. In particular, the Vainshtein radius of solar system objects can be altered from the static prediction when cosmological time-derivatives are non-negligible.
WILSON-BAPPU EFFECT: EXTENDED TO SURFACE GRAVITY
Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun; Lee, Sang-Gak E-mail: wskang@khu.ac.kr E-mail: sanggak@snu.ac.kr
2013-10-01
In 1957, Wilson and Bappu found a tight correlation between the stellar absolute visual magnitude (M{sub V} ) and the width of the Ca II K emission line for late-type stars. Here, we revisit the Wilson-Bappu relationship (WBR) to claim that the WBR can be an excellent indicator of stellar surface gravity of late-type stars as well as a distance indicator. We have measured the width (W) of the Ca II K emission line in high-resolution spectra of 125 late-type stars obtained with the Bohyunsan Optical Echelle Spectrograph and adopted from the Ultraviolet and Visual Echelle Spectrograph archive. Based on our measurement of the emission line width (W), we have obtained a WBR of M{sub V} = 33.76 - 18.08 log W. In order to extend the WBR to being a surface gravity indicator, stellar atmospheric parameters such as effective temperature (T{sub eff}), surface gravity (log g), metallicity ([Fe/H]), and micro-turbulence ({xi}{sub tur}) have been derived from self-consistent detailed analysis using the Kurucz stellar atmospheric model and the abundance analysis code, MOOG. Using these stellar parameters and log W, we found that log g = -5.85 log W+9.97 log T{sub eff} - 23.48 for late-type stars.
Nonlinear structure formation in the cubic Galileon gravity model
Barreira, Alexandre; Li, Baojiu; Hellwing, Wojciech A.; Baugh, Carlton M.; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: c.m.baugh@durham.ac.uk
2013-10-01
We model the linear and nonlinear growth of large scale structure in the Cubic Galileon gravity model, by running a suite of N-body cosmological simulations using the ECOSMOG code. Our simulations include the Vainshtein screening effect, which reconciles the Cubic Galileon model with local tests of gravity. In the linear regime, the amplitude of the matter power spectrum increases by ? 20% with respect to the standard ?CDM model today. The modified expansion rate accounts for ? 15% of this enhancement, while the fifth force is responsible for only ? 5%. This is because the effective unscreened gravitational strength deviates from standard gravity only at late times, even though it can be twice as large today. In the nonlinear regime (k?>0.1h Mpc{sup ?1}), the fifth force leads to only a modest increase (?<8%) in the clustering power on all scales due to the very efficient operation of the Vainshtein mechanism. Such a strong effect is typically not seen in other models with the same screening mechanism. The screening also results in the fifth force increasing the number density of halos by less than 10%, on all mass scales. Our results show that the screening does not ruin the validity of linear theory on large scales which anticipates very strong constraints from galaxy clustering data. We also show that, whilst the model gives an excellent match to CMB data on small angular scales (l?>50), the predicted integrated Sachs-Wolfe effect is in tension with Planck/WMAP results.
Affine group formulation of the Standard Model coupled to gravity
Chou, Ching-Yi; Ita, Eyo; Soo, Chopin
2014-04-15
In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauders affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant ?, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and YangMills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the YangMills and Higgs energy densities, are composed with Yorks integrated time functional. The result, when combined with the imaginary part of the ChernSimons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: WheelerDeWitt equation (WDW) quantized as affine algebra, realizing Klauders program. WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. Constructed a family of physical states for the full, coupled theory via affine coherent states. Fundamental uncertainty relation, predicated on non-vanishing cosmological constant.
Halo model and halo properties in Galileon gravity cosmologies
Barreira, Alexandre; Li, Baojiu; Hellwing, Wojciech A.; Baugh, Carlton M.; Lombriser, Lucas; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: llo@roe.ac.uk E-mail: silvia.pascoli@durham.ac.uk
2014-04-01
We investigate the performance of semi-analytical modelling of large-scale structure in Galileon gravity cosmologies using results from N-body simulations. We focus on the Cubic and Quartic Galileon models that provide a reasonable fit to CMB, SNIa and BAO data. We demonstrate that the Sheth-Tormen mass function and linear halo bias can be calibrated to provide a very good fit to our simulation results. We also find that the halo concentration-mass relation is well fitted by a power law. The nonlinear matter power spectrum computed in the halo model approach is found to be inaccurate in the mildly nonlinear regime, but captures reasonably well the effects of the Vainshtein screening mechanism on small scales. In the Cubic model, the screening mechanism hides essentially all of the effects of the fifth force inside haloes. In the case of the Quartic model, the screening mechanism leaves behind residual modifications to gravity, which make the effective gravitational strength time-varying and smaller than the standard value. Compared to normal gravity, this causes a deficiency of massive haloes and leads to a weaker matter clustering on small scales. For both models, we show that there are realistic halo occupation distributions of Luminous Red Galaxies that can match both the observed large-scale clustering amplitude and the number density of these galaxies.
The role of vector fields in modified gravity scenarios
Tasinato, Gianmassimo; Koyama, Kazuya; Khosravi, Nima E-mail: kazuya.koyama@port.ac.uk
2013-11-01
Gravitational vector degrees of freedom typically arise in many examples of modified gravity models. We start to systematically explore their role in these scenarios, studying the effects of coupling gravitational vector and scalar degrees of freedom. We focus on set-ups that enjoy a Galilean symmetry in the scalar sector and an Abelian gauge symmetry in the vector sector. These symmetries, together with the requirement that the equations of motion contain at most two space-time derivatives, only allow for a small number of operators in the Lagrangian for the gravitational fields. We investigate the role of gravitational vector fields for two broad classes of phenomena that characterize modified gravity scenarios. The first is self-acceleration: we analyze in general terms the behavior of vector fluctuations around self-accelerating solutions, and show that vanishing kinetic terms of vector fluctuations lead to instabilities on cosmological backgrounds. The second phenomenon is the screening of long range fifth forces by means of Vainshtein mechanism. We show that if gravitational vector fields are appropriately coupled to a spherically symmetric source, they can play an important role for defining the features of the background solution and the scale of the Vainshtein radius. Our general results can be applied to any concrete model of modified gravity, whose low-energy vector and scalar degrees of freedom satisfy the symmetry requirements that we impose.
Dust gravitational drift wave in complex plasma under gravity
Salahshoor, M. Niknam, A. R.
2014-12-15
The dispersion relation of electrostatic waves in a complex plasma under gravity is presented. It is assumed that the waves propagate parallel to the external fields. The effects of weak electric field, neutral drag force, and ion drag force are also taken into account. The dispersion relation is numerically examined in an appropriate parameter space in which the gravity plays the dominant role in the dynamics of microparticles. The numerical results show that, in the low pressure complex plasma under gravity, a low frequency drift wave can be developed in the long wavelength limit. The stability state of this wave is switched at a certain critical wavenumber in such a way that the damped mode is transformed into a growing one. Furthermore, the influence of the external fields on the dispersion properties is analyzed. It is shown that the wave instability is essentially due to the electrostatic streaming of plasma particles. It is also found that by increasing the electric field strength, the stability switching occurs at smaller wavenumbers.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
(1986- ) ANSI nuclear standards API (selected) ASCE ASHRAE ASME ASME-BPVC ASQ ASSESAFE ASTM AWS DRM (11th ed.) EIA IAPMO 2009 (Mechanical, Plumbing, Solar) Uncheck "Most Recent...
Constraints on a f(R) gravity dark energy model with early scaling evolution
Park, Chan-Gyung; Hwang, Jai-chan; Noh, Hyerim E-mail: jchan@knu.ac.kr
2011-09-01
The modified gravity with f(R) = R{sup 1+?} (? > 0) allows a scaling solution where the energy density of gravity sector follows the energy density of the dominant fluid. We present initial conditions of background and perturbation variables during the scaling evolution regime in the modified gravity. As a possible dark energy model we consider a gravity with a form f(R) = R{sup 1+?}+qR{sup ?n} (?1 < n ? 0) where the second term drives the late-time acceleration. We show that our f(R) gravity parameters are very sensitive to the baryon perturbation growth and baryon density power spectrum, and present observational constraints on the model parameters. We consider full perturbations of f(R) gravity. Our analysis suggests that only the parameter space extremely close to the ?CDM model is allowed with ??<5 10{sup ?6} and n?>?10{sup ?4}.
Gravity Duals of Lifshitz-Like Fixed Points (Journal Article) | SciTech
Office of Scientific and Technical Information (OSTI)
Connect Gravity Duals of Lifshitz-Like Fixed Points Citation Details In-Document Search Title: Gravity Duals of Lifshitz-Like Fixed Points We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our
Reduced Gravity Education Flight Opportunity for Students at Minority Serving Institutions
Broader source: Energy.gov [DOE]
NASA is offering undergraduate students from Minority Serving Institutions an opportunity to test experiments in microgravity aboard NASA's reduced gravity aircraft.
DETECTING GRAVITY MODES IN THE SOLAR {sup 8} B NEUTRINO FLUX
Lopes, Ildio; Turck-Chize, Sylvaine E-mail: ilopes@uevora.pt
2014-09-10
The detection of gravity modes produced in the solar radiative zone has been a challenge in modern astrophysics for more than 30yr and their amplitude in the core is not yet determined. In this Letter, we develop a new strategy to look for standing gravity modes through solar neutrino fluxes. We note that due to a resonance effect, the gravity modes of low degree and low order have the largest impact on the {sup 8} B neutrino flux. The strongest effect is expected to occur for the dipole mode with radial order 2, corresponding to periods of about 1.5 hr. These standing gravity waves produce temperature fluctuations that are amplified by a factor of 170 in the boron neutrino flux for the corresponding period, in consonance with the gravity modes. From current neutrino observations, we determine that the maximum temperature variation due to the gravity modes in the Sun's core is smaller than 5.8 10{sup 4}. This study clearly shows that due to their high sensitivity to the temperature, the {sup 8} B neutrino flux time series is an excellent tool to determine the properties of gravity modes in the solar core. Moreover, if gravity mode footprints are discovered in the {sup 8} B neutrino flux, this opens a new line of research to probe the physics of the solar core as non-standing gravity waves of higher periods cannot be directly detected by helioseismology but could leave their signature on boron neutrino or on other neutrino fluxes.
Broader source: Energy.gov [DOE]
Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition presentation at the April 2013 peer review meeting held in Denver, Colorado.
Ground Gravity Survey At Salt Wells Area (Bureau of Land Management...
2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Salt Wells Area (Bureau of Land Management, 2009) Exploration...
Ground Gravity Survey At U.S. West Region (Aiken & Ander, 1981...
and southern Colorado References Carlos L.V. Aiken, Mark E. Ander (1981) A Regional Strategy For Geothermal Exploration With Emphasis On Gravity And Magnetotellurics Additional...
Ground Gravity Survey At Blue Mountain Geothermal Area (U.S....
search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Blue Mountain Geothermal Area (U.S. Geological Survey, 2012) Exploration Activity Details...
Ground Gravity Survey At Cove Fort Area (Toksoz, Et Al, 2010...
Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes We...
Ground Gravity Survey At San Emidio Desert Area (DOE GTP) | Open...
Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At San Emidio Desert Area (DOE GTP)...
Ground Gravity Survey At Maui Area (DOE GTP) | Open Energy Information
Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Maui Area (DOE GTP) Exploration Activity Details...
Ground Gravity Survey At Raft River Geothermal Area (1957-1961...
search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Raft River Geothermal Area (1957-1961) Exploration Activity Details Location Raft River...
Translation invariant time-dependent massive gravity: Hamiltonian analysis
Mourad, Jihad; Steer, Danile A.; Noui, Karim E-mail: karim.noui@lmpt.univ-tours.fr
2014-09-01
The canonical structure of the massive gravity in the first order moving frame formalism is studied. We work in the simplified context of translation invariant fields, with mass terms given by general non-derivative interactions, invariant under the diagonal Lorentz group, depending on the moving frame as well as a fixed reference frame. We prove that the only mass terms which give 5 propagating degrees of freedom are the dRGT mass terms, namely those which are linear in the lapse. We also complete the Hamiltonian analysis with the dynamical evolution of the system.
Self-gravity in neutrino-dominated accretion disks
Liu, Tong; Yu, Xiao-Fei; Gu, Wei-Min; Lu, Ju-Fu
2014-08-10
We present the effects of self-gravity on the vertical structure and neutrino luminosity of the neutrino-dominated accretion disks in cylindrical coordinates. It is found that significant changes of the structure appear in the outer region of the disk, especially for high accretion rates (e.g., ? 1 M{sub ?} s{sup 1}), and thus cause the slight increase in the neutrino luminosity. Furthermore, the gravitational instability of the disk is reviewed by the vertical distribution of the Toomre parameter, which may account for the late-time flares in gamma-ray bursts and the extended emission in short-duration gamma-ray bursts.
Properties of solar gravity mode signals in total irradiance observations
Kroll, R.J.; Chen, J.; Hill, H.A.
1988-01-01
Further evidence has been found that a significant fraction of the gravity mode power density in the total irradiance observations appears in sidebands of classified eigenfrequencies. These sidebands whose amplitudes vary from year to year are interpreted as harmonics of the rotational frequencies of the nonuniform solar surface. These findings are for non axisymmetric modes and corroborate the findings of Kroll, Hill and Chen for axisymmetric modes. It is demonstrated the the generation of the sidebands lifts the usual restriction on the parity of the eigenfunctions for modes detectable in total irradiance observations. 14 refs.
Is Cosmic Acceleration Telling Us Something About Gravity?
Trodden, Mark [Syracuse University, Syracuse, New York, United States
2009-09-01
Among the possible explanations for the observed acceleration of the universe, perhaps the boldest is the idea that new gravitational physics might be the culprit. In this colloquium I will discuss some of the challenges of constructing a sensible phenomenological extension of General Relativity, give examples of some candidate models of modified gravity and survey existing observational constraints on this approach. I will conclude by discussing how we might hope to distinguish between modifications of General Relativity and dark energy as competing hypotheses to explain cosmic acceleration.
Confronting DGP braneworld gravity with cosmico observations after Planck data
Xu, Lixin
2014-02-01
The normal branch of Dvali-Gabadadze-Porrati braneworld gravity with brane tension is confronted by the currently available cosmic observations from the geometrical and dynamical perspectives. On the geometrical side, the type Ia supernova as standard candle, the baryon acoustic oscillation as standard ruler and the cosmic microwave background measurement from the first released 15.5 months data were used to fix the background evolutions. On the dynamical side, the redshift space distortion data will be used to determine the evolution of the matter perturbation. Through a Markov chain Monte Carlo analysis, we found the dimensionless crossover scale ?{sub r{sub c}} = 1/(4H{sup 2}{sub 0}r{sup 2}{sub c}) = 0.00183{sub ?0.00183}{sup +0.000338} in a spatially flat normal branch of Dvali-Gabadadze-Porrati braneworld. This result suggests that the crossover scale r{sub c} should be around 12H{sup ?1}{sub 0} which is consistent with the previous result r{sub c} > 3H{sup ?1}{sub 0} and greater. It also implies that the five-dimensional gravity effect is weak to be observed in H{sup ?1}{sub 0} scale.
Simulating the quartic Galileon gravity model on adaptively refined meshes
Li, Baojiu; Barreira, Alexandre; Baugh, Carlton M.; Hellwing, Wojciech A.; Koyama, Kazuya; Zhao, Gong-Bo; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: wojciech.hellwing@durham.ac.uk E-mail: silvia.pascoli@durham.ac.uk
2013-11-01
We develop a numerical algorithm to solve the high-order nonlinear derivative-coupling equation associated with the quartic Galileon model, and implement it in a modified version of the ramses N-body code to study the effect of the Galileon field on the large-scale matter clustering. The algorithm is tested for several matter field configurations with different symmetries, and works very well. This enables us to perform the first simulations for a quartic Galileon model which provides a good fit to the cosmic microwave background (CMB) anisotropy, supernovae and baryonic acoustic oscillations (BAO) data. Our result shows that the Vainshtein mechanism in this model is very efficient in suppressing the spatial variations of the scalar field. However, the time variation of the effective Newtonian constant caused by the curvature coupling of the Galileon field cannot be suppressed by the Vainshtein mechanism. This leads to a significant weakening of the strength of gravity in high-density regions at late times, and therefore a weaker matter clustering on small scales. We also find that without the Vainshtein mechanism the model would have behaved in a completely different way, which shows the crucial role played by nonlinearities in modified gravity theories and the importance of performing self-consistent N-body simulations for these theories.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Jaffe, Todd
2012-01-01
Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Jaffe, Todd
Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012
Translation invariant time-dependent solutions to massive gravity II
Mourad, J.; Steer, D.A. E-mail: steer@apc.univ-paris7.fr
2014-06-01
This paper is a sequel to JCAP 12 (2013) 004 and is also devoted to translation-invariant solutions of ghost-free massive gravity in its moving frame formulation. Here we consider a mass term which is linear in the vielbein (corresponding to a ?{sub 3} term in the 4D metric formulation) in addition to the cosmological constant. We determine explicitly the constraints, and from the initial value formulation show that the time-dependent solutions can have singularities at a finite time. Although the constraints give, as in the ?{sub 1} case, the correct number of degrees of freedom for a massive spin two field, we show that the lapse function can change sign at a finite time causing a singular time evolution. This is very different to the ?{sub 1} case where time evolution is always well defined. We conclude that the ?{sub 3} mass term can be pathological and should be treated with care.
Thermodynamic behavior of particular f(R,T)-gravity models
Sharif, M. Zubair, M.
2013-08-15
We investigate the thermodynamics at the apparent horizon of the FRW universe in f(R, T) theory in the nonequilibrium description. The laws of thermodynamics are discussed for two particular models of the f(R, T) theory. The first law of thermodynamics is expressed in the form of the Clausius relation T{sub h} dS-circumflex{sub h} = {delta} Q , where {delta}Q is the energy flux across the horizon and dS-circumflex is the entropy production term. Furthermore, the conditions for the generalized second law of thermodynamics to be preserved are established with the constraints of positive temperature and attractive gravity. We illustrate our results for some concrete models in this theory.
Phenomenology of electrostatically charged droplet combustion in normal gravity
Anderson, Eric K.; Koch, Jeremy A.; Kyritsis, Dimitrios C.
2008-08-15
Experimental findings are provided on the effect of electrostatically charging a fuel on single-burning droplet combustion in normal gravity. It was established that significant modification of the flame morphology and the droplet burning time could be achieved, solely by the droplet charge, without the application of external electric fields. Negative charging of the droplets of mixtures of isooctane with either ethanol or a commercially available anti-static additive generated intense motion of the flame and abbreviated the droplet burning time by as much as 40% for certain blend compositions. Positive charging of the droplets generated almost spherical flames, because electrostatic attraction toward the droplets countered the effect of buoyancy. By comparing combustion of droplets of the same conductivity but different compositions, coupling of electrostatics with combustion chemistry was established. (author)
The application of Raman laser in gravity measurement and metrology
Ru, Ning; Zhang, Li; Wang, Yu; Fan, Shangchun
2014-05-27
Atom Interferometry is proved to be a potential method for measuring the acceleration of atoms due to Gravity, we are now building a feasible system of cold atom gravimeter, it is based on the atom interferometry technology by coherently manipulating the cold atoms in a fountain (with a height of 1m) with specific Raman lasers, the cold atom wave packet is splitted, combined, and then re-splitted in the process. Then the atomic wave packet will acquire different phase because of the different evolution path. The precise acceleration can be deduced through the precision measurement of atomic interference fringes phase, and this will be a high precision standard of acceleration. At present, the preparation of Raman laser and the precise control of the laser Frequency have been finished, and they have been proved to meet the requirements of the experiment.
INTERNAL GRAVITY WAVES IN MASSIVE STARS: ANGULAR MOMENTUM TRANSPORT
Rogers, T. M.; Lin, D. N. C.; McElwaine, J. N.; Lau, H. H. B. E-mail: lin@ucolick.org E-mail: hblau@astro.uni-bonn.de
2013-07-20
We present numerical simulations of internal gravity waves (IGW) in a star with a convective core and extended radiative envelope. We report on amplitudes, spectra, dissipation, and consequent angular momentum transport by such waves. We find that these waves are generated efficiently and transport angular momentum on short timescales over large distances. We show that, as in Earth's atmosphere, IGW drive equatorial flows which change magnitude and direction on short timescales. These results have profound consequences for the observational inferences of massive stars, as well as their long term angular momentum evolution. We suggest IGW angular momentum transport may explain many observational mysteries, such as: the misalignment of hot Jupiters around hot stars, the Be class of stars, Ni enrichment anomalies in massive stars, and the non-synchronous orbits of interacting binaries.
Self-Consistent Cosmological Simulations of DGP Braneworld Gravity
Schmidt, Fabian; /Chicago U., Astron. Astrophys. Ctr. /KICP, Chicago
2009-09-01
We perform cosmological N-body simulations of the Dvali-Gabadadze-Porrati braneworld model, by solving the full non-linear equations of motion for the scalar degree of freedom in this model, the brane bending mode. While coupling universally to matter, the brane-bending mode has self-interactions that become important as soon as the density field becomes non-linear. These self-interactions lead to a suppression of the field in high-density environments, and restore gravity to General Relativity. The code uses a multi-grid relaxation scheme to solve the non-linear field equation in the quasi-static approximation. We perform simulations of a flat self-accelerating DGP model without cosmological constant. However, the type of non-linear interactions of the brane-bending mode, which are the focus of this study, are generic to a wide class of braneworld cosmologies. The results of the DGP simulations are compared with standard gravity simulations assuming the same expansion history, and with DGP simulations using the linearized equation for the brane bending mode. This allows us to isolate the effects of the non-linear self-couplings of the field which are noticeable already on quasi-linear scales. We present results on the matter power spectrum and the halo mass function, and discuss the behavior of the brane bending mode within cosmological structure formation. We find that, independently of CMB constraints, the self-accelerating DGP model is strongly constrained by current weak lensing and cluster abundance measurements.
Testing universal relations of neutron stars with a nonlinear matter-gravity coupling theory
Sham, Y.-H.; Lin, L.-M.; Leung, P. T. E-mail: lmlin@phy.cuhk.edu.hk
2014-02-01
Due to our ignorance of the equation of state (EOS) beyond nuclear density, there is still no unique theoretical model for neutron stars (NSs). It is therefore surprising that universal EOS-independent relations connecting different physical quantities of NSs can exist. Lau et al. found that the frequency of the f-mode oscillation, the mass, and the moment of inertia are connected by universal relations. More recently, Yagi and Yunes discovered the I-Love-Q universal relations among the mass, the moment of inertia, the Love number, and the quadrupole moment. In this paper, we study these universal relations in the Eddington-inspired Born-Infeld (EiBI) gravity. This theory differs from general relativity (GR) significantly only at high densities due to the nonlinear coupling between matter and gravity. It thus provides us an ideal case to test how robust the universal relations of NSs are with respect to the change of the gravity theory. Due to the apparent EOS formulation of EiBI gravity developed recently by Delsate and Steinhoff, we are able to study the universal relations in EiBI gravity using the same techniques as those in GR. We find that the universal relations in EiBI gravity are essentially the same as those in GR. Our work shows that, within the currently viable coupling constant, there exists at least one modified gravity theory that is indistinguishable from GR in view of the unexpected universal relations.
How Does Gravity Work to Hold a Human Down? | GE Global Research
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Does Gravity Work to Hold a Human Down? Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) How Does Gravity Work to Hold a Human Down? 2012.04.13 Chief Scientist Jim Bray discusses how velocity and gravity affect space travel. 0 Comments Comment Name Email Submit Comment You Might Also Like Lucas_Malta_airplane_V Green
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calculated in terms of the following for- mula: Deg API 141.5 sp gr60degF 60degF - 131.5 The higher the API gravity, the lighter the compound. Light crudes generally exceed...
Generalised BRST symmetry and gaugeon formalism for perturbative quantum gravity: Novel observation
Upadhyay, Sudhaker
2014-05-15
In this paper the novel features of Yokoyama gaugeon formalism are stressed out for the theory of perturbative quantum gravity in the Einstein curved spacetime. The quantum gauge transformations for the theory of perturbative gravity are demonstrated in the framework of gaugeon formalism. These quantum gauge transformations lead to renormalised gauge parameter. Further, we analyse the BRST symmetric gaugeon formalism which embeds more acceptable KugoOjima subsidiary condition. Further, the BRST symmetry is made finite and field-dependent. Remarkably, the Jacobian of path integral under finite and field-dependent BRST symmetry amounts to the exact gaugeon action in the effective theory of perturbative quantum gravity. -- Highlights: We analyse the perturbative gravity in gaugeon formalism. The generalisation of BRST transformation is also studied in this context. Within the generalised BRST framework we found the exact gaugeon modes in the theory.
Gravity survey of Dixie Valley, west-central Nevada | Open Energy...
to library Report: Gravity survey of Dixie Valley, west-central Nevada Author Donald H. Schaefer Published US Geological Survey, 1983 Report Number 82-111 DOI Not Provided...
Violation of the first law of black hole thermodynamics in f(T) gravity
Miao, Rong-Xin; Li, Miao; Miao, Yan-Gang E-mail: mli@itp.ac.cn
2011-11-01
We prove that, in general, the first law of black hole thermodynamics, ?Q = T?S, is violated in f(T) gravity. As a result, it is possible that there exists entropy production, which implies that the black hole thermodynamics can be in non-equilibrium even in the static spacetime. This feature is very different from that of f(R) or that of other higher derivative gravity theories. We find that the violation of first law results from the lack of local Lorentz invariance in f(T) gravity. By investigating two examples, we note that f''(0) should be negative in order to avoid the naked singularities and superluminal motion of light. When f''(T) is small, the entropy of black holes in f(T) gravity is approximatively equal to f'(T)/4 A.
Toward the AdS/CFT gravity dual for high energy collisions. II...
Office of Scientific and Technical Information (OSTI)
II. The stress tensor on the boundary Citation Details In-Document Search Title: Toward the AdSCFT gravity dual for high energy collisions. II. The stress tensor on the boundary ...
Mirzatuny, Nareg; Khosravi, Shahram; Baghram, Shant; Moshafi, Hossein E-mail: khosravi@mail.ipm.ir E-mail: hosseinmoshafi@iasbs.ac.ir
2014-01-01
In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in f(R) framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale dependent bias and growth rate functions. The deviation from ?CDM in the case of primordial non-Gaussian models is in large scales, while the growth rate deviates from ?CDM in small scales for modified gravity theories. We show that the redshift space distortion can be used to distinguish positive and negative f{sub NL} in standard background, while in f(R) theories they are not easily distinguishable. The galaxy power spectrum is generally enhanced in presence of non-Gaussianity and modified gravity. We also obtain the scale dependence of this enhancement. Finally we define galaxy growth rate and galaxy growth rate bias as new observational parameters to constrain cosmology.
Ground Gravity Survey At Cove Fort Area (Warpinski, Et Al., 2004...
Ground Gravity Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....
Microsoft PowerPoint - AAVP.ASTM.Monterey..ppt
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ARM Science Team Meeting Hyatt Regency Monterey Monterey, CA Rickey Petty March 29 th , 2007 ARM Aerial Vehicle Program (AAVP) ARM-UAV conducted 12 major field campaigns Field Campaigns to date: Fall 1993, Edwards AFB, CA Spring 1994, Northern OK Fall 1995, Northern OK Spring 1996, Northern OK Fall 1996, Northern OK Fall 1997, Northern OK Spring 1999, PMRF Kauai, HI Summer 1999, Monterey, CA Winter 2000, Northern OK Fall 2002, Northern OK Fall 2004, North Slope, AK Winter 2006, Darwin, Australia
New Cosmologies on the Horizon. Cosmology and Holography in bigravity and massive gravity
Tolley, Andrew James
2013-03-31
The goal of this research program is to explore the cosmological dynamics, the nature of cosmological and black hole horizons, and the role of holography in a new class of infrared modified theories of gravity. This will capitalize of the considerable recent progress in our understanding of the dynamics of massive spin two fields on curved spacetimes, culminating in the formulation of the first fully consistent theories of massive gravity and bigravity/bimetric theories.
Pure gravity mediation and spontaneous B-L breaking from strong dynamics
Office of Scientific and Technical Information (OSTI)
(Journal Article) | DOE PAGES Pure gravity mediation and spontaneous B-L breaking from strong dynamics « Prev Next » Title: Pure gravity mediation and spontaneous B-L breaking from strong dynamics Authors: Babu, Kaladi S. ; Schmitz, Kai ; Yanagida, Tsutomu T. Publication Date: 2016-04-01 OSTI Identifier: 1236278 Grant/Contract Number: SC0010108 Type: Published Article Journal Name: Nuclear Physics. B Additional Journal Information: Journal Volume: 905; Journal Issue: C; Journal ID: ISSN
Borehole Gravity Meter Surveys at the Waste Treatment Plant, Hanford, Washington.
MacQueen, Jeffrey D.; Mann, Ethan
2007-04-06
Microg-LaCoste (MGL) was contracted by Pacfic Northwest National Laboratories (PNNL) to record borehole gravity density data in 3 wells at the HanfordWaste Treatment Plant (WTP) site. The survey was designed to provide highly accurate density information for use in seismic modeling. The borehole gravity meter (BHGM) tool has a very large depth of investigation (hundreds of feet) compared to other density tools so it is not influenced by casing or near welbore effects, such as washouts.
Topological black holes in Lovelock-Born-Infeld gravity
Dehghani, M. H.; Alinejadi, N.; Hendi, S. H.
2008-05-15
In this paper, we present topological black holes of third order Lovelock gravity in the presence of cosmological constant and nonlinear electromagnetic Born-Infeld field. Depending on the metric parameters, these solutions may be interpreted as black hole solutions with inner and outer event horizons, an extreme black hole or naked singularity. We investigate the thermodynamics of asymptotically flat solutions and show that the thermodynamic and conserved quantities of these black holes satisfy the first law of thermodynamic. We also endow the Ricci flat solutions with a global rotation and calculate the finite action and conserved quantities of these class of solutions by using the counterterm method. We compute the entropy through the use of the Gibbs-Duhem relation and find that the entropy obeys the area law. We obtain a Smarr-type formula for the mass as a function of the entropy, the angular momenta, and the charge, and compute temperature, angular velocities, and electric potential and show that these thermodynamic quantities coincide with their values which are computed through the use of geometry. Finally, we perform a stability analysis for this class of solutions in both the canonical and the grand-canonical ensemble and show that the presence of a nonlinear electromagnetic field and higher curvature terms has no effect on the stability of the black branes, and they are stable in the whole phase space.
Mass gap for gravity localized on Weyl thick branes
Barbosa-Cendejas, N.; Santos, M. A. Reyes; Herrera-Aguilar, A.; Schubert, C.
2008-06-15
We consider thick brane configurations in a pure geometric Weyl integrable 5D space-time, a non-Riemannian generalization of Kaluza-Klein (KK) theory involving a geometric scalar field. Thus, the 5D theory describes gravity coupled to a self-interacting scalar field which gives rise to the structure of the thick branes. We continue the study of the properties of a previously found family of solutions which is smooth at the position of the brane but involves naked singularities in the fifth dimension. Analyzing their graviton spectrum, we find that a particularly interesting situation arises for a special case in which the 4D graviton is separated from the KK gravitons by a mass gap. The corresponding effective Schroedinger equation has a modified Poeschl-Teller potential and can be solved exactly. Apart from the massless 4D graviton, it contains one massive KK bound state, and the continuum spectrum of delocalized KK modes. We also discuss the mass hierarchy problem, and explicitly compute the corrections to Newton's law in the thin brane limit.
Asymptotically flat radiating solutions in third order Lovelock gravity
Dehghani, M. H.; Farhangkhah, N.
2008-09-15
In this paper, we present an exact spherically symmetric solution of third order Lovelock gravity in n dimensions which describes the gravitational collapse of a null dust fluid. This solution is asymptotically (anti-)de Sitter or flat depending on the choice of the cosmological constant. Using the asymptotically flat solution for n{>=}7 with a power-law form of the mass as a function of the null coordinate, we present a model for a gravitational collapse in which a null dust fluid radially injects into an initially flat and empty region. It is found that a naked singularity is inevitably formed whose strength is different for the n=7 and n{>=}8 cases. In the n=7 case, the limiting focusing condition for the strength of curvature singularity is satisfied. But for n{>=}8, the strength of curvature singularity depends on the rate of increase of mass of the spacetime. These considerations show that the third order Lovelock term weakens the strength of the curvature singularity.
Avoidance of singularities in asymptotically safe Quantum Einstein Gravity
Kofinas, Georgios; Zarikas, Vasilios
2015-10-30
New general spherically symmetric solutions have been derived with a cosmological “constant” Λ as a source. This Λ term is not constant but it satisfies the properties of the asymptotically safe gravity at the ultraviolet fixed point. The importance of these solutions comes from the fact that they may describe the near to the centre region of black hole spacetimes as this is modified by the Renormalization Group scaling behaviour of the fields. The consistent set of field equations which respect the Bianchi identities is derived and solved. One of the solutions (with conventional sign of temporal-radial metric components) is timelike geodesically complete, and although there is still a curvature divergent origin, this is never approachable by an infalling massive particle which is reflected at a finite distance due to the repulsive origin. Another family of solutions (of both signatures) range from a finite radius outwards, they cannot be extended to the centre of spherical symmetry, and the curvature invariants are finite at the minimum radius.
Generalized second law of thermodynamics in f(T) gravity
Karami, K.; Abdolmaleki, A. E-mail: AAbdolmaleki@uok.ac.ir
2012-04-01
We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics in the framework of f(T) modified teleparallel gravity. We consider a spatially flat FRW universe containing only the pressureless matter. The boundary of the universe is assumed to be enclosed by the Hubble horizon. For two viable f(T) models containing f(T) = T+?{sub 1}((?T)){sup n} and f(T) = T??{sub 2}T(1?e{sup ?T{sub 0}/T}), we first calculate the effective equation of state and deceleration parameters. Then, (we investigate the null and strong energy conditions and conclude that a sudden future singularity appears in both models. Furthermore, using a cosmographic analysis we check the viability of two models. Finally, we examine the validity of the GSL and find that for both models it) is satisfied from the early times to the present epoch. But in the future, the GSL is violated for the special ranges of the torsion scalar T.
Can f(T) gravity theories mimic ?CDM cosmic history
Setare, M.R.; Mohammadipour, N. E-mail: N.Mohammadipour@uok.ac.ir
2013-01-01
Recently the teleparallel Lagrangian density described by the torsion scalar T has been extended to a function of T. The f(T) modified teleparallel gravity has been proposed as the natural gravitational alternative for dark energy to explain the late time acceleration of the universe. In order to reconstruct the function f(T) by demanding a background ?CDM cosmology we assume that, (i) the background cosmic history provided by the flat ?CDM (the radiation ere with ?{sub eff} = (1/3), matter and de Sitter eras with ?{sub eff} = 0 and ?{sub eff} = ?1, respectively) (ii) the radiation dominate in the radiation era with ?{sub 0r} = 1 and the matter dominate during the matter phases when ?{sub 0m} = 1. We find the cosmological dynamical system which can obey the ?CDM cosmic history. In each era, we find a critical lines that, the radiation dominated and the matter dominated are one points of them in the radiation and matter phases, respectively. Also, we drive the cosmologically viability condition for these models. We investigate the stability condition with respect to the homogeneous scalar perturbations in each era and we obtain the stability conditions for the fixed points in each eras. Finally, we reconstruct the function f(T) which mimics cosmic expansion history.
Slowly rotating neutron and strange stars in R{sup 2} gravity
Staykov, Kalin V.; Yazadjiev, Stoytcho S.; Doneva, Daniela D.; Kokkotas, Kostas D. E-mail: daniela.doneva@uni-tuebingen.de E-mail: kostas.kokkotas@uni-tuebingen.de
2014-10-01
In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity with Lagrangian f(R)=R+aR{sup 2}, where a is a parameter. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in f(R)-gravity and then simultaneously solve numerically the exterior and the interior problem. The structure of the slowly rotating neutron stars is studied for two different hadronic equations of state and a strange matter equation of state. The moment of inertia and its dependence on the stellar mass and the R-squared gravity parameter a is also examined in details. The numerical results show that the neutron star moment of inertia can be up to 30% larger compared to the corresponding general relativistic models. This is much higher than the change in the maximum mass induced by R-squared gravity and is beyond the EOS uncertainty. In this way the future observations of the moment of inertia of compact stars could allow us to distinguish between general relativity and f(R) gravity, and more generally to test the strong field regime of gravity.
Gravity waves from non-minimal quadratic inflation
Pallis, Constantinos; Shafi, Qaisar
2015-03-12
We discuss non-minimal quadratic inflation in supersymmetric (SUSY) and non-SUSY models which entails a linear coupling of the inflaton to gravity. Imposing a lower bound on the parameter c{sub R}, involved in the coupling between the inflaton and the Ricci scalar curvature, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity up to the Planck scale. Working in the non-SUSY context we also consider radiative corrections to the inflationary potential due to a possible coupling of the inflaton to bosons or fermions. We find ranges of the parameters, depending mildly on the renormalization scale, with adjustable values of the spectral index n{sub s}, tensor-to-scalar ratio r≃(2−4)⋅10{sup −3}, and an inflaton mass close to 3⋅10{sup 13} GeV. In the SUSY framework we employ two gauge singlet chiral superfields, a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields, and determine uniquely the superpotential by applying a continuous R and a global U(1) symmetry. When the Kähler manifold exhibits a no-scale-type symmetry, the model predicts n{sub s}≃0.963 and r≃0.004. Beyond no-scale SUGRA, n{sub s} and r depend crucially on the coefficient involved in the fourth order term, which mixes the inflaton with the accompanying non-inflaton field in the Kähler potential, and the prefactor encountered in it. Increasing slightly the latter above (−3), an efficient enhancement of the resulting r can be achieved putting it in the observable range. The inflaton mass in the last case is confined in the range (5−9)⋅10{sup 13} GeV.
Universality of the acceleration due to gravity on the surface of a rapidly rotating neutron star
AlGendy, Mohammad; Morsink, Sharon M.
2014-08-20
On the surface of a rapidly rotating neutron star, the effective centrifugal force decreases the effective acceleration due to gravity (as measured in the rotating frame) at the equator while increasing the acceleration at the poles due to the centrifugal flattening of the star into an oblate spheroid. We compute the effective gravitational acceleration for relativistic rapidly rotating neutron stars and show that for a star with mass M, equatorial radius R{sub e} , and angular velocity ?, the deviations of the effective acceleration due to gravity from the nonrotating case take on a universal form that depends only on the compactness ratio M/R{sub e} , the dimensionless square of the angular velocity ?{sup 2}R{sub e}{sup 3}/GM, and the latitude on the star's surface. This dependence is universal, in that it has very little dependence on the neutron star's equation of state. The effective gravity is expanded in the slow-rotation limit to show the dependence on the effective centrifugal force, oblate shape of the star, and the quadrupole moment of the gravitational field. In addition, an empirical fit and simple formula for the effective gravity is found. We find that the increase in the acceleration due to gravity at the poles is of the same order of magnitude as the decrease in the effective acceleration due to gravity at the equator for all realistic value of mass, radius, and spin. For neutron stars that spin with frequencies near 600 Hz, the difference between the effective gravity at the poles and the equator is about 20%.
A Sea Floor Gravity Survey of the Sleipner Field to Monitor CO2 Migration
Mark Zumberge
2011-09-30
Carbon dioxide gas (CO{sub 2}) is a byproduct of many wells that produce natural gas. Frequently the CO{sub 2} separated from the valuable fossil fuel gas is released into the atmosphere. This adds to the growing problem of the climatic consequences of greenhouse gas contamination. In the Sleipner North Sea natural gas production facility, the separated CO{sub 2} is injected into an underground saline aquifer to be forever sequestered. Monitoring the fate of such sequestered material is important - and difficult. Local change in Earth's gravity field over the injected gas is one way to detect the CO{sub 2} and track its migration within the reservoir over time. The density of the injected gas is less than that of the brine that becomes displaced from the pore space of the formation, leading to slight but detectable decrease in gravity observed on the seafloor above the reservoir. Using equipment developed at Scripps Institution of Oceanography, we have been monitoring gravity over the Sleipner CO{sub 2} sequestration reservoir since 2002. We surveyed the field in 2009 in a project jointly funded by a consortium of European oil and gas companies and the US Department of Energy. The value of gravity at some 30 benchmarks on the seafloor, emplaced at the beginning of the monitoring project, was observed in a week-long survey with a remotely operated vehicle. Three gravity meters were deployed on the benchmarks multiple times in a campaign-style survey, and the measured gravity values compared to those collected in earlier surveys. A clear signature in the map of gravity differences is well correlated with repeated seismic surveys.
Constraining the range of Yukawa gravity interaction from S2 star orbits
Borka, D.; Jovanovi?, V. Borka; Jovanovi?, P.; Zakharov, A.F. E-mail: pjovanovic@aob.rs E-mail: zakharov@itep.ru
2013-11-01
We consider possible signatures for Yukawa gravity within the Galactic Central Parsec, based on our analysis of the S2 star orbital precession around the massive compact dark object at the Galactic Centre, and on the comparisons between the simulated orbits in Yukawa gravity and two independent sets of observations. Our simulations resulted in strong constraints on the range of Yukawa interaction ? and showed that its most probable value in the case of S2 star is around 5000 - 7000 AU. At the same time, we were not able to obtain reliable constrains on the universal constant ? of Yukawa gravity, because the current observations of S2 star indicated that it may be highly correlated with parameter ? in the range (0 < ? < 1). For ? > 2 they are not correlated. However, the same universal constant which was successfully applied to clusters of galaxies and rotation curves of spiral galaxies (? = 1/3) also gives a satisfactory agreement with the observed orbital precession of the S2 star, and in that case the most probable value for the scale parameter is ? ? 30001500 AU. Also, the Yukawa gravity potential induces precession of S2 star orbit in the same direction as General Relativity for ? > 0 and for ? < ?1, and in the opposite direction for ?1 < ? < 0. The future observations with advanced facilities, such as GRAVITY or/and European Extremely Large Telescope, are needed in order to verify these claims.
Astrophysical tests of modified gravity: the morphology and kinematics of dwarf galaxies
Vikram, Vinu; Cabr, Anna; Jain, Bhuvnesh; VanderPlas, J.T. E-mail: annanusca@gmail.com E-mail: jakevdp@cs.washington.edu
2013-08-01
This paper is the third in a series on tests of gravity using observations of stars and nearby dwarf galaxies. We carry out four distinct tests using published data on the kinematics and morphology of dwarf galaxies, motivated by the theoretical work of Hui et al. (2009) and Jain and Vanderplas (2011). In a wide class of gravity theories a scalar field couples to matter and provides an attractive fifth force. Due to their different self-gravity, stars and gas may respond differently to the scalar force leading to several observable deviations from standard gravity. HI gas, red giant stars and main sequence stars can be displaced relative to each other, and the stellar disk can display warps or asymmetric rotation curves aligned with external potential gradients. To distinguish the effects of modified gravity from standard astrophysical phenomena, we use a control sample of galaxies that are expected to be screened from the fifth force. In all cases we find no significant deviation from the null hypothesis of general relativity. The limits obtained from dwarf galaxies are not yet competitive with the limits from cepheids obtained in our first paper, but can be improved to probe regions of parameter space that are inaccessible using other tests. We discuss how our methodology can be applied to new radio and optical observations of nearby galaxies.
Penarrubia, Jorge; Walker, Matthew G.
2012-11-20
We introduce the Minimum Entropy Method, a simple statistical technique for constraining the Milky Way gravitational potential and simultaneously testing different gravity theories directly from 6D phase-space surveys and without adopting dynamical models. We demonstrate that orbital energy distributions that are separable (i.e., independent of position) have an associated entropy that increases under wrong assumptions about the gravitational potential and/or gravity theory. Of known objects, 'cold' tidal streams from low-mass progenitors follow orbital distributions that most nearly satisfy the condition of separability. Although the orbits of tidally stripped stars are perturbed by the progenitor's self-gravity, systematic variations of the energy distribution can be quantified in terms of the cross-entropy of individual tails, giving further sensitivity to theoretical biases in the host potential. The feasibility of using the Minimum Entropy Method to test a wide range of gravity theories is illustrated by evolving restricted N-body models in a Newtonian potential and examining the changes in entropy introduced by Dirac, MONDian, and f(R) gravity modifications.
Neutron stars in a perturbative f(R) gravity model with strong magnetic fields
Cheoun, Myung-Ki; Deliduman, Cemsinan; Gngr, Can; Kele?, Vildan; Ryu, C.Y.; Kajino, Toshitaka; Mathews, Grant J. E-mail: cemsinan@msgsu.edu.tr E-mail: kelesvi@itu.edu.tr E-mail: kajino@nao.ac.jp
2013-10-01
In Kaluza-Klein electromagnetism it is natural to associate modified gravity with strong electromagnetic fields. Hence, in this paper we investigate the combined effects of a strong magnetic field and perturbative f(R) gravity on the structure of neutron stars. The effect of an interior strong magnetic field of about 10{sup 17?18} G on the equation of state is derived in the context of a quantum hadrodynamics (QHD) equation of state (EoS) including effects of the magnetic pressure and energy along with occupied Landau levels. Adopting a random orientation of interior field domains, we solve the modified spherically symmetric hydrostatic equilibrium equations derived for a gravity model with f(R) = R+?R{sup 2}. Effects of both the finite magnetic field and the modified gravity are detailed for various values of the magnetic field and the perturbation parameter ? along with a discussion of their physical implications. We show that there exists a parameter space of the modified gravity and the magnetic field strength, in which even a soft equation of state can accommodate a large ( > 2 M{sub s}un) maximum neutron star mass.
Device for detecting the specific gravity of a liquid. [Patent application
Derouin, C.R.; Kerwin, W.J.; McCormick, J.B.; Bobbett, R.E.
1980-11-18
A device for detecting the specific gravity of a liquid and a device for detecting the state of charge of a liquid phase electrolyte battery are described. In one embodiment of the present invention, a change in the critical angle of total internal reflection is utilized to determine the index of refraction of the liquid to be measured. It is shown that the index of refraction of the liquid is a function of the specific gravity of the liquid. In applications for measuring the state of charge of a battery, the specific gravity is proportional to the state of charge of the battery. A change in intensity of rays intersecting an interface surface indicates the critical angle which is a direct indication of the specific gravity of the liquid and the state of charge of a battery. In another embodiment, a light beam is projected through a transparent medium and then through a portion of the liquid to be measured. A change in refraction due to a change in the index of refraction of the liquid produces a deflection of the beam which is measured by a detector. The magnitude of deflection of the beam is directly proportional to the specific gravity of the liquid and the state of charge of a battery.
Christian, Joshua M.; Ho, Clifford Kuofei
2010-04-01
Understanding the effects of gravity and wind loads on concentrating solar power (CSP) collectors is critical for performance calculations and developing more accurate alignment procedures and techniques. This paper presents a rigorous finite-element model of a parabolic trough collector that is used to determine the impact of gravity loads on bending and displacements of the mirror facets and support structure. The geometry of the LUZ LS-2 parabolic trough collector was modeled using SolidWorks, and gravity-induced loading and displacements were simulated in SolidWorks Simulation. The model of the trough collector was evaluated in two positions: the 90{sup o} position (mirrors facing upward) and the 0{sup o} position (mirrors facing horizontally). The slope errors of the mirror facet reflective surfaces were found by evaluating simulated angular displacements of node-connected segments along the mirror surface. The ideal (undeformed) shape of the mirror was compared to the shape of the deformed mirror after gravity loading. Also, slope errors were obtained by comparing the deformed shapes between the 90{sup o} and 0{sup o} positions. The slope errors resulting from comparison between the deformed vs. undeformed shape were as high as {approx}2 mrad, depending on the location of the mirror facet on the collector. The slope errors resulting from a change in orientation of the trough from the 90{sup o} position to the 0{sup o} position with gravity loading were as high as {approx}3 mrad, depending on the location of the facet.
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Thermodynamics of asymptotically flat charged black holes in third order Lovelock gravity
Dehghani, M.H.; Shamirzaie, M.
2005-12-15
We present a new class of asymptotically flat charge static solutions in third order Lovelock gravity. These solutions present black hole solutions with two inner and outer event horizons, extreme black holes, or naked singularities provided the parameters of the solutions are chosen suitable. We find that the uncharged asymptotically flat solutions can present black holes with two inner and outer horizons. This kind of solution does not exist in Einstein or Gauss-Bonnet gravity, and it is a special effect in third order Lovelock gravity. We compute temperature, entropy, charge, electric potential, and mass of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis by computing the determinant of the Hessian matrix of the mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that there exists only an intermediate stable phase.
An experimental study of pool boiling heat transfer in reduced gravity
Shatto, D.P.; Renzi, K.I.; Peterson, G.P.; Morris, T.K.; Aaron, J.W.
1996-12-31
Experiments were performed in which pool boiling of pure water at reduced pressures was observed for behavior of the critical heatflux (CHF) and nucleate boiling heat transfer coefficients in a reduced gravitational environment. The experiments took place while alternating between microgravity and g/g{sub o} = 1.8 during parabolic flights aboard the NASA 930 (KC-135A). Heat transfer data were also obtained at Martian gravity levels (g/g{sub o} = 1/3). Parts of the test chamber were constructed of transparent materials to allow viewing and recording of the various boiling regimes encountered during the experiments. Results indicate that the onset of nucleate boiling occurred at lower heat fluxes in reduced gravity, resulting in higher two-phase heat transfer coefficients for g/g{sub o} < 1 than for g/g{sub o} = 1.8. In addition, the results indicate a significant reduction in the critical heat flux under reduced gravity conditions.
Inflation in Kaluza-Klein cosmology. 1; Transformation to fourth-order gravity
Schmidt, H.J. )
1990-12-20
This paper reports on the higher- dimensional Einstein equation with {Gamma}-term shown to be comformally equivalent to the four-dimensional field equation of scale-invariant fourth-order gravity. This holds for a general warped product between space-time and internal space of arbitrary dimension m which turns out to be an Einstein space. (The limit m {yields} {infinity} makes sense ) Thus, the results concerning the attractor property of the power- law inflationary solution derived for fourth-order gravity hold for the Kaluza-Klein model, too.
Quasispherical gravitational collapse in 5D Einstein-Gauss-Bonnet gravity
Ghosh, Sushant G.; Jhingan, S.
2010-07-15
We obtain a general five-dimensional quasispherical collapsing solutions of irrotational dust in Einstein gravity with the Gauss-Bonnet combination of quadratic curvature terms. These solutions are a generalization, to Einstein-Gauss-Bonnet gravity, of the five-dimensional quasispherical Szkeres like collapsing solutions in general relativity. It is found that the collapse proceeds in the same way as in the analogous spherical collapse, i.e., there exists regular initial data such that the collapse proceed to form naked singularities violating cosmic censorship conjecture. The effect of Gauss-Bonnet quadratic curvature terms on the formation and locations of the apparent horizon is deduced.
Toward the AdS/CFT gravity dual for high energy collisions. I. Falling into
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the AdS space (Journal Article) | SciTech Connect I. Falling into the AdS space Citation Details In-Document Search Title: Toward the AdS/CFT gravity dual for high energy collisions. I. Falling into the AdS space In the context of the AdS/CFT correspondence we discuss the gravity dual of a high energy collision in a strongly coupled N=4 SYM gauge theory. We suggest a setting in which two colliding objects are made of nondynamical heavy quarks and antiquarks, which allows one to treat the
Zhao, Gong-Bo
2014-04-01
Based on a suite of N-body simulations of the Hu-Sawicki model of f(R) gravity with different sets of model and cosmological parameters, we develop a new fitting formula with a numeric code, MGHalofit, to calculate the nonlinear matter power spectrum P(k) for the Hu-Sawicki model. We compare the MGHalofit predictions at various redshifts (z ? 1) to the f(R) simulations and find that the relative error of the MGHalofit fitting formula of P(k) is no larger than 6% at k ? 1 h Mpc{sup 1} and 12% at k in (1, 10] h Mpc{sup 1}, respectively. Based on a sensitivity study of an ongoing and a future spectroscopic survey, we estimate the detectability of a signal of modified gravity described by the Hu-Sawicki model using the power spectrum up to quasi-nonlinear scales.
Entirely passive heat-pipe apparatus capable of operating against gravity
Koenig, D.R.
1981-02-11
The disclosure is directed to an entirely passive heat pipe apparatus capable of operating against gravity for vertical distances in the order of 3 to 7 and more. A return conduit into which an inert gas is introduced is used to lower the specific density of the working fluid so that it may be returned a greater vertical distance from condenser to evaporator.
Effective matter cosmologies of massive gravity I: non-physical fluids
Y?lmaz, Nejat Tevfik
2014-08-01
For the massive gravity, after decoupling from the metric equation we find a broad class of solutions of the Stckelberg sector by solving the background metric in the presence of a diagonal physical metric. We then construct the dynamics of the corresponding FLRW cosmologies which inherit effective matter contribution through the decoupling solution mechanism of the scalar sector.
Existence of global weak solution for a reduced gravity two and a half layer model
Guo, Zhenhua Li, Zilai Yao, Lei
2013-12-15
We investigate the existence of global weak solution to a reduced gravity two and a half layer model in one-dimensional bounded spatial domain or periodic domain. Also, we show that any possible vacuum state has to vanish within finite time, then the weak solution becomes a unique strong one.
A scaling analysis of thermoacoustic convection in a zero-gravity environment
Krane, R.J.; Parang, M.
1982-01-01
This paper presents a scaling analysis of a one-dimensional thermoacoustic convection heat transfer process in a zero-gravity environment. The relative importance of the terms in the governing equations is discussed for different time scales without attempting to solve the equations. The scaling analysis suggests certain generalizations that can be made in this class of heat transfer problems.
Spherical collapse in Galileon gravity: fifth force solutions, halo mass function and halo bias
Barreira, Alexandre; Li, Baojiu; Baugh, Carlton M.; Pascoli, Silvia E-mail: liqb@mail.ihep.ac.cn E-mail: silvia.pascoli@durham.ac.uk
2013-11-01
We study spherical collapse in the Quartic and Quintic Covariant Galileon gravity models within the framework of the excursion set formalism. We derive the nonlinear spherically symmetric equations in the quasi-static and weak-field limits, focusing on model parameters that fit current CMB, SNIa and BAO data. We demonstrate that the equations of the Quintic model do not admit physical solutions of the fifth force in high density regions, which prevents the study of structure formation in this model. For the Quartic model, we show that the effective gravitational strength deviates from the standard value at late times (z?<1), becoming larger if the density is low, but smaller if the density is high. This shows that the Vainshtein mechanism at high densities is not enough to screen all of the modifications of gravity. This makes halos that collapse at z?<1 feel an overall weaker gravity, which suppresses halo formation. However, the matter density in the Quartic model is higher than in standard ?CDM, which boosts structure formation and dominates over the effect of the weaker gravity. In the Quartic model there is a significant overabundance of high-mass halos relative to ?CDM. Dark matter halos are also less biased than in ?CDM, with the difference increasing appreciably with halo mass. However, our results suggest that the bias may not be small enough to fully reconcile the predicted matter power spectrum with LRG clustering data.
Asymptotically (anti)-de Sitter solutions in Gauss-Bonnet gravity without a cosmological constant
Dehghani, M.H.
2004-09-15
In this paper I show that one can have asymptotically de Sitter, anti-de Sitter (AdS), and flat solutions in Gauss-Bonnet gravity without a cosmological constant term in field equations. First, I introduce static solutions whose three surfaces at fixed r and t have constant positive (k=1), negative (k=-1), or zero (k=0) curvature. I show that for k={+-}1 one can have asymptotically de Sitter, AdS, and flat spacetimes, while for the case of k=0, one has only asymptotically AdS solutions. Some of these solutions present naked singularities, while some others are black hole or topological black hole solutions. I also find that the geometrical mass of these five-dimensional spacetimes is m+2{alpha}|k|, which is different from the geometrical mass m of the solutions of Einstein gravity. This feature occurs only for the five-dimensional solutions, and is not repeated for the solutions of Gauss-Bonnet gravity in higher dimensions. Second, I add angular momentum to the static solutions with k=0, and introduce the asymptotically AdS charged rotating solutions of Gauss-Bonnet gravity. Finally, I introduce a class of solutions which yields an asymptotically AdS spacetime with a longitudinal magnetic field, which presents a naked singularity, and generalize it to the case of magnetic rotating solutions with two rotation parameters.
Non-perturbative and self-consistent models of neutron stars in R-squared gravity
Yazadjiev, Stoytcho S.; Doneva, Daniela D.; Kokkotas, Kostas D.; Staykov, Kalin V. E-mail: daniela.doneva@uni-tuebingen.de E-mail: kalin.v.staikov@gmail.com
2014-06-01
In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in R-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for several equations of state and for wide range of the R-squared gravity parameter a. Even though the deviation from general relativity for nonzero values of a can be large, they are still comparable with the variations due to different modern realistic equations of state. That is why the current observations of the neutron star masses and radii alone can not put constraints on the value of the parameter a. We also compare our results with those obtained within the perturbative method and we discuss the differences between them.
Cosmological bounces in spatially flat FRW spacetimes in metric f(R) gravity
Paul, Niladri; Chakrabarty, Saikat Nil; Bhattacharya, Kaushik E-mail: snilch@iitk.ac.in
2014-10-01
The present work analyzes the various conditions in which there can be a bouncing universe solution in f(R) gravity. In the article an interesting method, to analyze the bouncing FRW solutions in a spatially flat universe using f(R) gravity models using an effective Einstein frame description of the process, is presented. The analysis shows that a cosmological bounce in the f(R) theory need not be described by an equivalent bounce in the Einstein frame description of the process where actually there may be no bounce at all. Nevertheless the Einstein frame description of the bouncing phenomena turns out to be immensely important as the dynamics of the bounce becomes amenable to logic based on general relativistic intuition. The theory of scalar cosmological perturbations in the bouncing universe models in f(R) theories has also been worked out in the Einstein frame.
The Role of Gravity Waves in the Formation and Organization of Clouds during TWPICE
Reeder, Michael J.; Lane, Todd P.; Hankinson, Mai Chi Nguyen
2013-09-27
All convective clouds emit gravity waves. While it is certain that convectively-generated waves play important parts in determining the climate, their precise roles remain uncertain and their effects are not (generally) represented in climate models. The work described here focuses mostly on observations and modeling of convectively-generated gravity waves, using the intensive observations from the DoE-sponsored Tropical Warm Pool International Cloud Experiment (TWP-ICE), which took place in Darwin, from 17 January to 13 February 2006. Among other things, the research has implications the part played by convectively-generated gravity waves in the formation of cirrus, in the initiation and organization of further convection, and in the subgrid-scale momentum transport and associated large-scale stresses imposed on the troposphere and stratosphere. The analysis shows two groups of inertia-gravity waves are detected: group L in the middle stratosphere during the suppressed monsoon period, and group S in the lower stratosphere during the monsoon break period. Waves belonging to group L propagate to the south-east with a mean intrinsic period of 35 h, and have vertical and horizontal wavelengths of about 5-6 km and 3000-6000 km, respectively. Ray tracing calculations indicate that these waves originate from a deep convective region near Indonesia. Waves belonging to group S propagate to the south-south-east with an intrinsic period, vertical wavelength and horizontal wavelength of about 45 h, 2 km and 2000-4000 km, respectively. These waves are shown to be associated with shallow convection in the oceanic area within about 1000 km of Darwin. The intrinsic periods of high-frequency waves are estimated to be between 20-40 minutes. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4-day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4-day modulation is explained by the variation of the convection activity in the TWP-ICE domain. At low rainfall intensity the wave activity increases as rainfall intensity increases. At high values of rainfall intensity, however, the wave activity associated with deep convective clouds is independent of the rainfall intensity. The convection and gravity waves observed during TWP-ICE are simulated with the Weather Research and Forecasting (WRF) Model. These simulations are compared with radiosonde observations described above and are used to determine some of the properties of convectively generated gravity waves. The gravity waves appear to be well simulated by the model. The model is used to explore the relationships between the convection, the gravity waves and cirrus.
The response of plasma density to breaking inertial gravity wave in the lower regions of ionosphere
Tang, Wenbo Mahalov, Alex
2014-04-15
We present a three-dimensional numerical study for the E and lower F region ionosphere coupled with the neutral atmosphere dynamics. This model is developed based on a previous ionospheric model that examines the transport patterns of plasma density given a prescribed neutral atmospheric flow. Inclusion of neutral dynamics in the model allows us to examine the charge-neutral interactions over the full evolution cycle of an inertial gravity wave when the background flow spins up from rest, saturates and eventually breaks. Using Lagrangian analyses, we show the mixing patterns of the ionospheric responses and the formation of ionospheric layers. The corresponding plasma density in this flow develops complex wave structures and small-scale patches during the gravity wave breaking event.
Patterns of gravity induced aggregate migration during casting of fluid concretes
Spangenberg, J. [Department of Mechanical Engineering, Technical University of Denmark (DTU) (Denmark)] [Department of Mechanical Engineering, Technical University of Denmark (DTU) (Denmark); Roussel, N., E-mail: Nicolas.roussel@lcpc.fr [Universite Paris Est, Laboratoire Central des Ponts et Chaussees (LCPC) (France); Hattel, J.H. [Department of Mechanical Engineering, Technical University of Denmark (DTU) (Denmark)] [Department of Mechanical Engineering, Technical University of Denmark (DTU) (Denmark); Sarmiento, E.V.; Zirgulis, G. [Department of Structural Engineering, Norwegian University of Science and Technology (NTNU) (Norway)] [Department of Structural Engineering, Norwegian University of Science and Technology (NTNU) (Norway); Geiker, M.R. [Department of Structural Engineering, Norwegian University of Science and Technology (NTNU) (Norway) [Department of Structural Engineering, Norwegian University of Science and Technology (NTNU) (Norway); Department of Civil Engineering, Technical University of Denmark (DTU) (Denmark)
2012-12-15
In this paper, aggregate migration patterns during fluid concrete castings are studied through experiments, dimensionless approach and numerical modeling. The experimental results obtained on two beams show that gravity induced migration is primarily affecting the coarsest aggregates resulting in a decrease of coarse aggregates volume fraction with the horizontal distance from the pouring point and in a puzzling vertical multi-layer structure. The origin of this multi layer structure is discussed and analyzed with the help of numerical simulations of free surface flow. Our results suggest that it finds its origin in the non Newtonian nature of fresh concrete and that increasing casting rate shall decrease the magnitude of gravity induced particle migration.
EinsteinCartan gravity, Asymptotic Safety, and the running Immirzi parameter
Daum, J.-E.; Reuter, M.
2013-07-15
In this paper we analyze the functional renormalization group flow of quantum gravity on the EinsteinCartan theory space. The latter consists of all action functionals depending on the spin connection and the vielbein field (co-frame) which are invariant under both spacetime diffeomorphisms and local frame rotations. In the first part of the paper we develop a general methodology and corresponding calculational tools which can be used to analyze the flow equation for the pertinent effective average action for any truncation of this theory space. In the second part we apply it to a specific three-dimensional truncated theory space which is parametrized by Newtons constant, the cosmological constant, and the Immirzi parameter. A comprehensive analysis of their scale dependences is performed, and the possibility of defining an asymptotically safe theory on this hitherto unexplored theory space is investigated. In principle Asymptotic Safety of metric gravity (at least at the level of the effective average action) is neither necessary nor sufficient for Asymptotic Safety on the EinsteinCartan theory space which might accommodate different universality classes of microscopic quantum gravity theories. Nevertheless, we do find evidence for the existence of at least one non-Gaussian renormalization group fixed point which seems suitable for the Asymptotic Safety construction in a setting where the spin connection and the vielbein are the fundamental field variables. -- Highlights: A functional RG equation for a first order formulation of gravity is constructed. The theory space constituted by tetrad and spin connection variables is explored. The RG equation is solved in a 3 dimensional truncation of theory space. The flow of Newtons constant, the cosmological constant and the Immirzi parameter is analyzed. Evidence for the nonperturbative renormalizability of the theory is found.
Astrophysical tests of modified gravity: Constraints from distance indicators in the nearby universe
Jain, Bhuvnesh; Vikram, Vinu; Sakstein, Jeremy
2013-12-10
We use distance measurements in the nearby universe to carry out new tests of gravity, surpassing other astrophysical tests by over two orders of magnitude for chameleon theories. The three nearby distance indicatorscepheids, tip of the red giant branch (TRGB) stars, and water masersoperate in gravitational fields of widely different strengths. This enables tests of scalar-tensor gravity theories because they are screened from enhanced forces to different extents. Inferred distances from cepheids and TRGB stars are altered (in opposite directions) over a range of chameleon gravity theory parameters well below the sensitivity of cosmological probes. Using published data, we have compared cepheid and TRGB distances in a sample of unscreened dwarf galaxies within 10 Mpc. We use a comparable set of screened galaxies as a control sample. We find no evidence for the order unity force enhancements expected in these theories. Using a two-parameter description of the models (the coupling strength and background field value), we obtain constraints on both the chameleon and symmetron screening scenarios. In particular we show that f(R) models with background field values f {sub R0} above 5 10{sup 7} are ruled out at the 95% confidence level. We also compare TRGB and maser distances to the galaxy NGC 4258 as a second test for larger field values. While there are several approximations and caveats in our study, our analysis demonstrates the power of gravity tests in the local universe. We discuss the prospects for additional improved tests with future observations.
Constraints on Covariant Horava-Lifshitz Gravity from frame-dragging experiment
Radicella, Ninfa; Lambiase, Gaetano; Parisi, Luca; Vilasi, Gaetano E-mail: lambiase@sa.infn.it E-mail: vilasi@sa.infn.it
2014-12-01
The effects of Horava-Lifshitz corrections to the gravito-magnetic field are analyzed. Solutions in the weak field, slow motion limit, referring to the motion of a satellite around the Earth are considered. The post-newtonian paradigm is used to evaluate constraints on the Horava-Lifshitz parameter space from current satellite and terrestrial experiments data. In particular, we focus on GRAVITY PROBE B, LAGEOS and the more recent LARES mission, as well as a forthcoming terrestrial project, GINGER.
The coupling to matter in massive, bi- and multi-gravity
Noller, Johannes; Melville, Scott E-mail: scott.melville@queens.ox.ac.uk
2015-01-01
In this paper we construct a family of ways in which matter can couple to one or more 'metrics'/spin-2 fields in the vielbein formulation. We do so subject to requiring the weak equivalence principle and the absence of ghosts from pure spin-2 interactions generated by the matter action. Results are presented for Massive, Bi- and Multi-Gravity theories and we give explicit expressions for the effective matter metric in all of these cases.
Tsunami and acoustic-gravity waves in water of constant depth
Hendin, Gali; Stiassnie, Michael
2013-08-15
A study of wave radiation by a rather general bottom displacement, in a compressible ocean of otherwise constant depth, is carried out within the framework of a three-dimensional linear theory. Simple analytic expressions for the flow field, at large distance from the disturbance, are derived. Realistic numerical examples indicate that the Acoustic-Gravity waves, which significantly precede the Tsunami, are expected to leave a measurable signature on bottom-pressure records that should be considered for early detection of Tsunami.
Toward the AdS/CFT gravity dual for high energy collisions. III.
Office of Scientific and Technical Information (OSTI)
Gravitationally collapsing shell and quasiequilibrium (Journal Article) | SciTech Connect III. Gravitationally collapsing shell and quasiequilibrium Citation Details In-Document Search Title: Toward the AdS/CFT gravity dual for high energy collisions. III. Gravitationally collapsing shell and quasiequilibrium The equilibration of matter and onset of hydrodynamics can be understood in the AdS/CFT context as a gravitational collapse process, in which 'collision debris' create a horizon. In
Spherically symmetric analysis on open FLRW solution in non-linear massive gravity
Chiang, Chien-I; Izumi, Keisuke; Chen, Pisin E-mail: izumi@phys.ntu.edu.tw
2012-12-01
We study non-linear massive gravity in the spherically symmetric context. Our main motivation is to investigate the effect of helicity-0 mode which remains elusive after analysis of cosmological perturbation around an open Friedmann-Lemaitre-Robertson-Walker (FLRW) universe. The non-linear form of the effective energy-momentum tensor stemming from the mass term is derived for the spherically symmetric case. Only in the special case where the area of the two sphere is not deviated away from the FLRW universe, the effective energy momentum tensor becomes completely the same as that of cosmological constant. This opens a window for discriminating the non-linear massive gravity from general relativity (GR). Indeed, by further solving these spherically symmetric gravitational equations of motion in vacuum to the linear order, we obtain a solution which has an arbitrary time-dependent parameter. In GR, this parameter is a constant and corresponds to the mass of a star. Our result means that Birkhoff's theorem no longer holds in the non-linear massive gravity and suggests that energy can probably be emitted superluminously (with infinite speed) on the self-accelerating background by the helicity-0 mode, which could be a potential plague of this theory.
Bounce cosmology from F(R) gravity and F(R) bigravity
Bamba, Kazuharu; Nojiri, Shin'ichi; Makarenko, Andrey N.; Odintsov, Sergei D.; Myagky, Alexandr N. E-mail: andre@tspu.edu.ru E-mail: nojiri@phys.nagoya-u.ac.jp
2014-01-01
We reconstruct F(R) gravity models with exponential and power-law forms of the scale factor in which bounce cosmology can be realized. We explore the stability of the reconstructed models with analyzing the perturbations from the background solutions. Furthermore, we study an F(R) gravity model with a sum of exponentials form of the scale factor, where the bounce in the early universe as well as the late-time cosmic acceleration can be realized in a unified manner. As a result, we build a second order polynomial type model in terms of R and show that it could be stable. Moreover, when the scale factor is expressed by an exponential form, we derive F(R) gravity models of a polynomial type in case of the non-zero spatial curvature and that of a generic type in that of the zero spatial curvature. In addition, for an exponential form of the scale factor, an F(R) bigravity model realizing the bouncing behavior is reconstructed. It is found that in both the physical and reference metrics the bouncing phenomenon can occur, although in general the contraction and expansion rates are different each other.
Dehghani, M.H.; Mann, R.B.
2006-05-15
We generalize the quasilocal definition of the stress-energy tensor of Einstein gravity to the case of third order Lovelock gravity, by introducing the surface terms that make the action well-defined. We also introduce the boundary counterterm that removes the divergences of the action and the conserved quantities of the solutions of third order Lovelock gravity with zero curvature boundary at constant t and r. Then, we compute the charged rotating solutions of this theory in n+1 dimensions with a complete set of allowed rotation parameters. These charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes or naked singularities provided the parameters of the solutions are suitably chosen. We compute temperature, entropy, charge, electric potential, mass and angular momenta of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We find a Smarr-type formula and perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable. This is commensurate with the fact that there is no Hawking-Page phase transition for black objects with zero curvature horizon.
Brane gravity, massless bulk scalar, and self-tuning of the cosmological constant
Kim, Jihn E.; Kyae, Bumseok; Shafi, Qaisar
2004-09-15
We show that a self-tuning mechanism of the cosmological constant could work in 5D noncompact space-time with a Z{sub 2} symmetry in the presence of a massless scalar field. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane (brane cosmological constant) by, for instance, electroweak and QCD phase transitions, just gives rise to dynamical shifts of the profiles of the background metric and the scalar field in the extra dimension, keeping 4D space-time flat without any fine-tuning. To avoid naked singularities in the bulk, the brane cosmological constant should be negative. We introduce an additional brane-localized 4D Einstein-Hilbert term so as to provide the observed 4D gravity with the noncompact extra dimension. With a general form of the brane-localized gravity term allowed by the symmetries, the low energy Einstein gravity is successfully reproduced on the brane at long distances. We show this phenomenon explicitly for the case of vanishing bulk cosmological constant.
Smith, L.B.; Durney, T.E. Jr.
1991-04-23
Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up millions of tons of coal fines in refuse piles and ponds. It is anticipated that the new centrifuge can become an important ancillary to the advanced deep cleaning processes for coal. Because of these convictions, CTC has been engaged in a pioneering research effort into the new art of drying fine clean coal in high gravity, high production, batch type of centrifuge, since 1981. This work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. It promises to provide needed fine coal drying capability at somewhat lower capital costs and at substantially lower operating costs than competitive systems. It also promises to do so with no detrimental effects on either the coal quality or the environment. The primary objective of this project is to prove the concept of a high gravity batch centrifuge for drying coal fines in a commercial coal processing plant environment. The proof of concept tests also include testing with a variety of coals from different regions. A further objective is to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology. 2 figs., 3 tabs.
Influence of heterogeneity on second-kind self-similar solutions for viscous gravity currents
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zheng, Zhong; Christov, Ivan C.; Stone, Howard A.
2014-04-16
We report experimental, theoretical and numerical results on the effects of horizontal heterogeneities on the propagation of viscous gravity currents. We use two geometries to highlight these effects: (a) a horizontal channel (or crack) whose gap thickness varies as a power-law function of the streamwise coordinate; (b) a heterogeneous porous medium whose permeability and porosity have power-law variations. We demonstrate that two types of self-similar behaviours emerge as a result of horizontal heterogeneity: (a) a first-kind self-similar solution is found using dimensional analysis (scaling) for viscous gravity currents that propagate away from the origin (a point of zero permeability); (b)more » a second-kind self-similar solution is found using a phase-plane analysis for viscous gravity currents that propagate toward the origin. These theoretical predictions, obtained using the ideas of self-similar intermediate asymptotics, are compared with experimental results and numerical solutions of the governing partial differential equation developed under the lubrication approximation. All three results are found to be in good agreement.« less
Influence of heterogeneity on second-kind self-similar solutions for viscous gravity currents
Zheng, Zhong; Christov, Ivan C.; Stone, Howard A.
2014-04-16
We report experimental, theoretical and numerical results on the effects of horizontal heterogeneities on the propagation of viscous gravity currents. We use two geometries to highlight these effects: (a) a horizontal channel (or crack) whose gap thickness varies as a power-law function of the streamwise coordinate; (b) a heterogeneous porous medium whose permeability and porosity have power-law variations. We demonstrate that two types of self-similar behaviours emerge as a result of horizontal heterogeneity: (a) a first-kind self-similar solution is found using dimensional analysis (scaling) for viscous gravity currents that propagate away from the origin (a point of zero permeability); (b) a second-kind self-similar solution is found using a phase-plane analysis for viscous gravity currents that propagate toward the origin. These theoretical predictions, obtained using the ideas of self-similar intermediate asymptotics, are compared with experimental results and numerical solutions of the governing partial differential equation developed under the lubrication approximation. All three results are found to be in good agreement.
Gardner, S; Gulam, M; Song, K; Li, H; Huang, Y; Zhao, B; Qin, Y; Snyder, K; Kim, J; Gordon, J; Chetty, I; Wen, N
2014-06-01
Purpose: The Varian EDGE machine is a new stereotactic platform, combining Calypso and VisionRT localization systems with a stereotactic linac. The system includes TrueBeam DeveloperMode, making possible the use of XML-scripting for automation of linac-related tasks. This study details the use of DeveloperMode to automate commissioning tasks for Varian EDGE, thereby improving efficiency and measurement consistency. Methods: XML-scripting was used for various commissioning tasks,including couch model verification,beam-scanning,and isocenter verification. For couch measurements, point measurements were acquired for several field sizes (22,44,1010cm{sup 2}) at 42 gantry angles for two couch-models. Measurements were acquired with variations in couch position(rails in/out,couch shifted in each of motion axes) compared to treatment planning system(TPS)-calculated values,which were logged automatically through advanced planning interface(API) scripting functionality. For beam scanning, XML-scripts were used to create custom MLC-apertures. For isocenter verification, XML-scripts were used to automate various Winston-Lutz-type tests. Results: For couch measurements, the time required for each set of angles was approximately 9 minutes. Without scripting, each set required approximately 12 minutes. Automated measurements required only one physicist, while manual measurements required at least two physicists to handle linac positions/beams and data recording. MLC apertures were generated outside of the TPS,and with the .xml file format, double-checking without use of TPS/operator console was possible. Similar time efficiency gains were found for isocenter verification measurements Conclusion: The use of XML scripting in TrueBeam DeveloperMode allows for efficient and accurate data acquisition during commissioning. The efficiency improvement is most pronounced for iterative measurements, exemplified by the time savings for couch modeling measurements(approximately 10 hours). The scripting also allowed for creation of the files in advance without requiring access to TPS. The API scripting functionality enabled efficient creation/mining of TPS data. Finally, automation reduces the potential for human error in entering linac values at the machine console,and the script provides a log of measurements acquired for each session. This research was supported in part by a grant from Varian Medical Systems, Palo Alto, CA.
Probing non-standard gravity with the growth index: a background independent analysis
Steigerwald, Heinrich; Marinoni, Christian; Bel, Julien E-mail: jbel@cpt.univ-mrs.fr
2014-05-01
Measurements of the growth index of linear matter density fluctuations ?(z) provide a clue as to whether Einstein's field equations encompass gravity also on large cosmic scales, those where the expansion of the universe accelerates. We show that the information encoded in this function can be satisfactorily parameterized using a small set of coefficients ?{sub i}, in such a way that the true scaling of the growth index is recovered to better than 1% in most dark energy and dark gravity models. We find that the likelihood of current data, given this formalism and the ? Cold Dark Matter (?CDM) expansion model of Planck, is maximal for ?{sub 0} = 0.74{sup +0.44}{sub ?0.41} and ?{sub 1} = 0.01{sup +0.46}{sub ?0.46}, a measurement compatible with the ?CDM predictions (?{sub 0} = 0.545, ?{sub 1} = ?0.007). In addition, data tend to favor models predicting slightly less growth of structures than the Planck ?CDM scenario. The main aim of the paper is to provide a prescription for routinely calculating, in an analytic way, the amplitude of the growth indices ?{sub i} in relevant cosmological scenarios, and to show that these parameters naturally define a space where predictions of alternative theories of gravity can be compared against growth data in a manner which is independent from the expansion history of the cosmological background. As the standard ?-plane provides a tool to identify different expansion histories H(t) and their relation to various cosmological models, the ?-plane can thus be used to locate different growth rate histories f(t) and their relation to alternatives model of gravity. As a result, we find that the Dvali-Gabadadze-Porrati gravity model is rejected with a 95% confidence level. By simulating future data sets, such as those that a Euclid-like mission will provide, we also show how to tell apart ?CDM predictions from those of more extreme possibilities, such as smooth dark energy models, clustering quintessence or parameterized post-Friedmann cosmological models.
Dandina N. Rao; Subhash C. Ayirala; Madhav M. Kulkarni; Wagirin Ruiz Paidin; Thaer N. N. Mahmoud; Daryl S. Sequeira; Amit P. Sharma
2006-09-30
This is the final report describing the evolution of the project ''Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery'' from its conceptual stage in 2002 to the field implementation of the developed technology in 2006. This comprehensive report includes all the experimental research, models developments, analyses of results, salient conclusions and the technology transfer efforts. As planned in the original proposal, the project has been conducted in three separate and concurrent tasks: Task 1 involved a physical model study of the new GAGD process, Task 2 was aimed at further developing the vanishing interfacial tension (VIT) technique for gas-oil miscibility determination, and Task 3 was directed at determining multiphase gas-oil drainage and displacement characteristics in reservoir rocks at realistic pressures and temperatures. The project started with the task of recruiting well-qualified graduate research assistants. After collecting and reviewing the literature on different aspects of the project such gas injection EOR, gravity drainage, miscibility characterization, and gas-oil displacement characteristics in porous media, research plans were developed for the experimental work to be conducted under each of the three tasks. Based on the literature review and dimensional analysis, preliminary criteria were developed for the design of the partially-scaled physical model. Additionally, the need for a separate transparent model for visual observation and verification of the displacement and drainage behavior under gas-assisted gravity drainage was identified. Various materials and methods (ceramic porous material, Stucco, Portland cement, sintered glass beads) were attempted in order to fabricate a satisfactory visual model. In addition to proving the effectiveness of the GAGD process (through measured oil recoveries in the range of 65 to 87% IOIP), the visual models demonstrated three possible multiphase mechanisms at work, namely, Darcy-type displacement until gas breakthrough, gravity drainage after breakthrough and film-drainage in gas-invaded zones throughout the duration of the process. The partially-scaled physical model was used in a series of experiments to study the effects of wettability, gas-oil miscibility, secondary versus tertiary mode gas injection, and the presence of fractures on GAGD oil recovery. In addition to yielding recoveries of up to 80% IOIP, even in the immiscible gas injection mode, the partially-scaled physical model confirmed the positive influence of fractures and oil-wet characteristics in enhancing oil recoveries over those measured in the homogeneous (unfractured) water-wet models. An interesting observation was that a single logarithmic relationship between the oil recovery and the gravity number was obeyed by the physical model, the high-pressure corefloods and the field data.
Morin, R.L. )
1993-04-01
An arc of mafic and ultramafic rocks is mapped from Asik Mountain to Siniktanneyak Mountain in the northwestern Brooks Range of Alaska. Gravity data, although not very detailed, have been collected over the region and show some very conspicuous circular or oval gravity highs over portions of the mapped mafic-ultramafic bodies. Bodies which have large associated gravity anomalies are Asik Mountain (80 mGal), Avon Hills (20 mGal), Misheguk Mountain (30 mGal), and Siniktanneyak Mountain (20 mGal). Gabbros of the Siniktanneyak Mountain complex, where the gravity coverage is best, have densities of about 3.0 g/cm[sup 3] while the densities of the surrounding sedimentary rocks are about 2.6 g/cm[sup 3]. Volcanic rocks in the area have average densities of about 2.7 g/cm[sup 3]. Three-dimensional modeling indicates that the largest anomaly, on the southwestern part of the complex, could be caused by a polygonal prism of gabbro with vertical sides, about 6 km across and about 4.5 km deep. A smaller lobe of the anomaly on the northeast of the complex could be caused by another oblong polygonal prism about 4 km long and 2 km wide trending northeast and about 1.5 km deep. Modeling this anomaly with densities lower than gabbro would require greater thicknesses to produce the same anomaly. Modeling each anomaly along this arc in 2 1/2-dimensions shows many possible solutions using different body shapes and different density contrasts. There are several other gravity anomalies in this vicinity which could represent unexposed high density rocks. One such anomaly is in the Maiyumerak Mountains northeast of Asik Mountain (30 mGal). Another anomaly is to the northwest of Asik Mountain (20 mGal). There is also an anomaly at Uchugrak (20 mGal) east of Avan Hills. Although many of the anomalies in this region are poorly controlled, an attempt has been made to interpret the data to show possible solutions.
Peralta, J.; Lpez-Valverde, M. A.; Imamura, T.; Read, P. L.; Luz, D.; Piccialli, A.
2014-07-01
This paper is the first of a two-part study devoted to developing tools for a systematic classification of the wide variety of atmospheric waves expected on slowly rotating planets with atmospheric superrotation. Starting with the primitive equations for a cyclostrophic regime, we have deduced the analytical solution for the possible waves, simultaneously including the effect of the metric terms for the centrifugal force and the meridional shear of the background wind. In those cases when the conditions for the method of the multiple scales in height are met, these wave solutions are also valid when vertical shear of the background wind is present. A total of six types of waves have been found and their properties were characterized in terms of the corresponding dispersion relations and wave structures. In this first part, only waves that are direct solutions of the generic dispersion relation are studiedacoustic and inertia-gravity waves. Concerning inertia-gravity waves, we found that in the cases of short horizontal wavelengths, null background wind, or propagation in the equatorial region, only pure gravity waves are possible, while for the limit of large horizontal wavelengths and/or null static stability, the waves are inertial. The correspondence between classical atmospheric approximations and wave filtering has been examined too, and we carried out a classification of the mesoscale waves found in the clouds of Venus at different vertical levels of its atmosphere. Finally, the classification of waves in exoplanets is discussed and we provide a list of possible candidates with cyclostrophic regimes.
Evaluation of an enhanced gravity-based fine-coal circuit for high-sulfur coal
Mohanty, M.K.; Samal, A.R.; Palit, A.
2008-02-15
One of the main objectives of this study was to evaluate a fine-coal cleaning circuit using an enhanced gravity separator specifically for a high sulfur coal application. The evaluation not only included testing of individual unit operations used for fine-coal classification, cleaning and dewatering, but also included testing of the complete circuit simultaneously. At a scale of nearly 2 t/h, two alternative circuits were evaluated to clean a minus 0.6-mm coal stream utilizing a 150-mm-diameter classifying cyclone, a linear screen having a projected surface area of 0.5 m{sup 2}, an enhanced gravity separator having a bowl diameter of 250 mm and a screen-bowl centrifuge having a bowl diameter of 500 mm. The cleaning and dewatering components of both circuits were the same; however, one circuit used a classifying cyclone whereas the other used a linear screen as the classification device. An industrial size coal spiral was used to clean the 2- x 0.6-mm coal size fraction for each circuit to estimate the performance of a complete fine-coal circuit cleaning a minus 2-mm particle size coal stream. The 'linear screen + enhanced gravity separator + screen-bowl circuit' provided superior sulfur and ash-cleaning performance to the alternative circuit that used a classifying cyclone in place of the linear screen. Based on these test data, it was estimated that the use of the recommended circuit to treat 50 t/h of minus 2-mm size coal having feed ash and sulfur contents of 33.9% and 3.28%, respectively, may produce nearly 28.3 t/h of clean coal with product ash and sulfur contents of 9.15% and 1.61 %, respectively.
Tewari, S.N.; Kumar, M.V.; Lee, J.E.; Curreri, P.A.
1990-11-01
Primary dendrite spacings, secondary dendrite spacings, and microsegregation have been examined in PWA-1480 single crystal specimens which were directionally solidified during parabolic maneuvers on the KC-135 aircraft. Experimentally observed growth rate and thermal gradient dependence of primary dendrite spacings are in good agreement with predictions from dendrite growth models for binary alloys. Secondary dendrite coarsening kinetics show a reasonable fit with the predictions from an analytical model proposed by Kirkwood for a binary alloy. The partition coefficients of tantalum, titanium, and aluminum are observed to be less than unity, while that for tungsten and cobalt are greater than unity. This is qualitatively similar to the nickel base binaries. Microsegregation profiles experimentally observed for PWA-1480 superalloy show a good fit with Bower, Brody, and Flemings model developed for binary alloys. Transitions in gravity levels do not appear to affect primary dendrite spacings. A trend of decreased secondary arm spacings with transition from high gravity to the low gravity period was observed at a growth speed of 0.023 cm s(exp -1). However, definite conclusions can only be drawn by experiments at lower growth speeds which make it possible to examine the side-branch coarsening kinetics over a longer duration. Such experiments, not possible due to the insufficient low-gravity time of the KC-135, may be carried out in the low-gravity environment of space.
Probing low-scale quantum gravity with high-energy neutrinos
Ennadifi, Salah Eddine
2013-05-15
Motivated by the quantum structure of space-time at high scales M{sub QG}, we study the propagation behavior of the high-energy neutrino within the quantum gravity effect. We consider the possible induced dispersive effect and derive the resulting vacuum refraction index {eta}{sub vac}(E{sub {nu}}) Asymptotically-Equal-To 1 + E{sub {nu}}{sup 2}/M{sub QG}{sup 2}. Then, by referring to the SN1987A and basing on the recorded neutrino data we approach the corresponding scale M{sub QG} Asymptotically-Equal-To 10{sup 4} GeV.
Generalized uncertainty principle in f(R) gravity for a charged black hole
Said, Jackson Levi; Adami, Kristian Zarb
2011-02-15
Using f(R) gravity in the Palatini formularism, the metric for a charged spherically symmetric black hole is derived, taking the Ricci scalar curvature to be constant. The generalized uncertainty principle is then used to calculate the temperature of the resulting black hole; through this the entropy is found correcting the Bekenstein-Hawking entropy in this case. Using the entropy the tunneling probability and heat capacity are calculated up to the order of the Planck length, which produces an extra factor that becomes important as black holes become small, such as in the case of mini-black holes.
Five-dimensional black strings in Einstein-Gauss-Bonnet gravity
Kobayashi, Tsutomu; Tanaka, Takahiro
2005-04-15
We consider black-string-type solutions in five-dimensional Einstein-Gauss-Bonnet gravity. Numerically constructed solutions under static, axially symmetric and translationally invariant metric ansatz are presented. The solutions are specified by two asymptotic charges: mass of a black string and a scalar charge associated with the radion part of the metric. Regular black string solutions are found if and only if the two charges satisfy a fine-tuned relation, and otherwise the spacetime develops a singular event horizon or a naked singularity. We can also generate bubble solutions from the black strings by using a double Wick rotation.
Phantom-like behavior of a DGP-inspired Scalar-Gauss-Bonnet gravity
Nozari, Kourosh; Azizi, Tahereh; Setare, M.R. E-mail: t.azizi@umz.ac.ir
2009-10-01
We study the phantom-like behavior of a DGP-inspired braneworld scenario where curvature correction on the brane is taken into account. We include a possible modification of the induced gravity on the brane by incorporating higher order curvature terms of Gauss-Bonnet type. We investigate the cosmological implications of the model and we show that the normal branch of the scenario self-accelerates in this modified scenario without introducing any dark energy component. Also, a phantom-like behavior can be realized in this model without introducing any phantom field that suffers from serious difficulties such as violation of the null energy condition.
High-Accuracy Measurements of the Centre of Gravity of Avalanches in Proportional Chambers
DOE R&D Accomplishments [OSTI]
Charpak, G.; Jeavons, A.; Sauli, F.; Stubbs, R.
1973-09-24
In a multiwire proportional chamber the avalanches occur close to the anode wires. The motion of the positive ions in the large electric fields at the vicinity of the wires induces fast-rising positive pulses on the surrounding electrodes. Different methods have been developed in order to determine the position of the centre of the avalanches. In the method we describe, the centre of gravity of the pulse distribution is measured directly. It seems to lead to an accuracy which is limited only by the stability of the spatial distribution of the avalanches generated by the process being measured.
Toward the AdS/CFT gravity dual for high energy collisions. II. The stress
Office of Scientific and Technical Information (OSTI)
tensor on the boundary (Journal Article) | SciTech Connect II. The stress tensor on the boundary Citation Details In-Document Search Title: Toward the AdS/CFT gravity dual for high energy collisions. II. The stress tensor on the boundary In this second paper of the series, we calculate the stress tensor of excited matter, created by debris of high energy collisions at the boundary. The falling open strings, connected to receding charges, produce a nonzero stress tensor which we found
Donovan-Ealy, P.F. . Geology Dept.); Hendricks, J.D. )
1992-01-01
The Hopi Buttes volcanic field is located in the Navajo Nation of northeastern Arizona, near the southern margin of the Colorado Plateau. Explosive phreatomagmatic eruptions from late Miocene to mid-Pliocene time produced more than 300 maar-diatremes and deposited limburgite tuffs and tuff breccia and monchiquite dikes, necks and flows within a roughly circular 2,500 km[sup 2] area. The volcanic and volcaniclastic rocks make up the middle member of the Bidahochi Formation, whose lower and upper members are lacustrine and fluvial, respectively. The Bidahochi Formation overlies gently dipping Mesozoic sedimentary rocks exposed in the southwestern portion of the volcanic field. Two significant gravity and magnetic anomalies appear within the Hopi Buttes volcanic field that are unlike the signatures of other Tertiary volcanic fields on the Colorado Plateau. A circular 20 mGal negative gravity anomaly is centered over exposed sedimentary rocks in the southwestern portion of the field. The anomaly may be due to the large volume of low density pyroclastic rocks in the volcanic field and/or extensive brecciation of the underlying strata from the violent maar eruptions. The second significant anomaly is the northeast-trending Holbrook lineament, a 5 km-wide gravity and magnetic lineament that crosses the southeastern part of the volcanic field. The lineament reflects substantial gravity and magnetic decreases of 1.67 mGals/km and 100 gammas/km respectively, to the southeast. Preliminary two-dimensional gravity and magnetic modeling suggests the lineament represents a major Proterozoic crustal boundary and may correlate with one of several Proterozoic faults exposed in the transition zone of central Arizona. Gravity modeling shows a 3--5 km step'' in the Moho near the crustal boundary. The decrease in depth of the Moho to the northwest indicates either movement along the fault or magmatic upwelling beneath the volcanic field.
Constraining models of f(R) gravity with Planck and WiggleZ power spectrum data
Dossett, Jason; Parkinson, David; Hu, Bin E-mail: hu@lorentz.leidenuniv.nl
2014-03-01
In order to explain cosmic acceleration without invoking ''dark'' physics, we consider f(R) modified gravity models, which replace the standard Einstein-Hilbert action in General Relativity with a higher derivative theory. We use data from the WiggleZ Dark Energy survey to probe the formation of structure on large scales which can place tight constraints on these models. We combine the large-scale structure data with measurements of the cosmic microwave background from the Planck surveyor. After parameterizing the modification of the action using the Compton wavelength parameter B{sub 0}, we constrain this parameter using ISiTGR, assuming an initial non-informative log prior probability distribution of this cross-over scale. We find that the addition of the WiggleZ power spectrum provides the tightest constraints to date on B{sub 0} by an order of magnitude, giving log{sub 10}(B{sub 0}) < ?4.07 at 95% confidence limit. Finally, we test whether the effect of adding the lensing amplitude A{sub Lens} and the sum of the neutrino mass ?m{sub ?} is able to reconcile current tensions present in these parameters, but find f(R) gravity an inadequate explanation.
Benini, Marco Dappiaggi, Claudio; Murro, Simone
2014-08-01
We discuss the quantization of linearized gravity on globally hyperbolic, asymptotically flat, vacuum spacetimes, and the construction of distinguished states which are both of Hadamard form and invariant under the action of all bulk isometries. The procedure, we follow, consists of looking for a realization of the observables of the theory as a sub-algebra of an auxiliary, non-dynamical algebra constructed on future null infinity ??. The applicability of this scheme is tantamount to proving that a solution of the equations of motion for linearized gravity can be extended smoothly to ??. This has been claimed to be possible provided that a suitable gauge fixing condition, first written by Geroch and Xanthopoulos [Asymptotic simplicity is stable, J. Math. Phys. 19, 714 (1978)], is imposed. We review its definition critically, showing that there exists a previously unnoticed obstruction in its implementation leading us to introducing the concept of radiative observables. These constitute an algebra for which a Hadamard state induced from null infinity and invariant under the action of all spacetime isometries exists and it is explicitly constructed.
Spin-orbit alignment for 110 day period KOI368.01 from gravity darkening
Ahlers, John P.; Seubert, Shayne A.; Barnes, Jason W.
2014-05-10
We fit the Kepler photometric light curve of the KOI-368 system using an oblate, gravity-darkened stellar model in order to constrain its spin-orbit alignment. We find that the system is relatively well-aligned with a sky-projected spin-orbit alignment of ? = 10 2, a stellar obliquity of ? = 3 7, and a true spin-orbit alignment of ? = 11 3. Although our measurement differs significantly from zero, the low value for ? is consistent with spin-orbit alignment. We also measure various transit parameters of the KOI-368 system: R {sub KOI-368} = 2.28 0.02 R {sub ?}, R{sub p} = 1.83 0.02 R {sub jup}, and i = 89.221 0.013. This work shows that our gravity-darkened model can constrain long-period, well-aligned planets and M-class stars orbiting fast-rotators, allowing for measurement of a new subcategory of transiting bodies.
Hamiltonian dynamics of an exotic action for gravity in three dimensions
Escalante, Alberto Manuel-Cabrera, J.
2014-04-15
The Hamiltonian dynamics and the canonical covariant formalism for an exotic action in three dimensions are performed. By working with the complete phase space, we report a complete Hamiltonian description of the theory such as the extended action, the extended Hamiltonian, the algebra among the constraints, the Diracs brackets and the correct gauge transformations. In addition, we show that in spite of exotic action and tetrad gravity with a cosmological constant give rise to the same equations of motion, they are not equivalent, in fact, we show that their corresponding Diracs brackets are quite different. Finally, we construct a gauge invariant symplectic form which in turn represents a complete Hamiltonian description of the covariant phase space. -- Highlights: We report a detailed Hamiltonian analysis for an exotic action of gravity. We show that Palatini and exotic actions are not equivalent. The exotic action is a non-commutative theory. The fundamental gauge transformations of the theory are ?-deformed Poincar transformations. A Lorentz and gauge invariant symplectic two-form is constructed.
Preliminary gravity inversion model of basins east of Yucca Flat, Nevada Test Site, Nevada.
Geoffrey A. Phelps; Carter W. Roberts, and Barry C. Moring
2006-03-17
The Yucca Flat eastern extension study area, a 14 kilometer by 45 kilometer region contiguous to Yucca Flat on the west and Frenchman Flat on the south, is being studied to expand the boundary of the Yucca Flat hydrogeologic model. The isostatic residual gravity anomaly was inverted to create a model of the depth of the geologic basins within the study area. Such basins typically are floored by dense pre-Tertiary basement rocks and filled with less-dense Tertiary volcanic and sedimentary rocks and Quaternary alluvium, a necessary condition for the use of gravity modeling to predict the depth to the pre-Tertiary basement rocks within the basins. Three models were created: a preferred model to represent the best estimate of depth to pre-Tertiary basement rocks in the study area, and two end-member models to demonstrate the possible range of solutions. The preferred model predicts shallow basins, generally less than 1,000m depth, throughout the study area, with only Emigrant Valley reaching a depth of 1,100m. Plutonium valley and West Fork Scarp Canyon have maximum depths of 800m and 1,000m, respectively. The end-member models indicate that the uncertainty in the preferred model is less than 200m for most of the study area.
Thermodynamics of rotating black branes in (n+1)-dimensional Einstein-Born-Infeld gravity
Dehghani, M. H.; Sedehi, H. R. Rastegar
2006-12-15
We construct a new class of charged rotating solutions of (n+1)-dimensional Einstein-Born-Infeld gravity with cylindrical or toroidal horizons in the presence of cosmological constant and investigate their properties. These solutions are asymptotically (anti)-de Sitter and reduce to the solutions of Einstein-Maxwell gravity as the Born-Infeld parameters goes to infinity. We find that these solutions can represent black branes, with inner and outer event horizons, an extreme black brane or a naked singularity provided the parameters of the solutions are chosen suitably. We compute temperature, mass, angular momentum, entropy, charge and electric potential of the black brane solutions. We obtain a Smarr-type formula and show that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass of the system with infinite boundary with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable in the whole phase space. Also, we find that there exists an unstable phase when the finite size effect is taken into account.
Thermodynamics of rotating solutions in (n+1)-dimensional Einstein-Maxwell-dilaton gravity
Sheykhi, A.; Riazi, N.; Pakravan, J.; Dehghani, M. H.
2006-10-15
We construct a class of charged, rotating solutions of (n+1)-dimensional Einstein-Maxwell-dilaton gravity with cylindrical or toroidal horizons in the presence of Liouville-type potentials and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We find that these solutions can represent black brane, with inner and outer event horizons, an extreme black brane or a naked singularity provided the parameters of the solutions are chosen suitably. We also compute temperature, entropy, charge, electric potential, mass and angular momentum of the black brane solutions, and find that these quantities satisfy the first law of thermodynamics. We find a Smarr-type formula and perform a stability analysis by computing the heat capacity in the canonical ensemble. We find that the system is thermally stable when the coupling constant between the dilaton and matter field {alpha}{<=}1, while for {alpha}>1 the system has an unstable phase. This shows that the dilaton field makes the solution unstable, while it is stable even in Lovelock gravity.
Thermodynamics of rotating solutions in Gauss-Bonnet-Maxwell gravity and the counterterm method
Dehghani, M. H.; Bordbar, G. H.; Shamirzaie, M.
2006-09-15
By a suitable transformation, we present the (n+1)-dimensional charged rotating solutions of Gauss-Bonnet gravity with a complete set of allowed rotation parameters which are real in the whole spacetime. We show that these charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes, or naked singularities provided the parameters of the solutions are chosen suitable. Using the surface terms that make the action well defined for Gauss-Bonnet gravity and the counterterm method for eliminating the divergences in action, we compute finite action of the solutions. We compute the conserved and thermodynamical quantities through the use of free energy and the counterterm method, and find that the two methods give the same results. We also find that these quantities satisfy the first law of thermodynamics. Finally, we perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable. This is commensurate with the fact that there is no Hawking-Page phase transition for black objects with zero curvature horizon.
Smith, L.B.; Durney, T.E. Jr.
1990-07-24
Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up the millions of tons of coal fines in refuse piles and ponds. It is anticipated that the new centrifuge can become an important ancillary to the advanced deep cleaning processes for coal. Because of these convictions, CTC has been engaged in a pioneering research effort into the new art of drying fine clean coal in high gravity, high production, batch type centrifuges, since 1981. This work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. It promises to provide needed fine coal drying capability at somewhat lower capital costs and at substantially lower operating costs than competitive systems. It also promises to do so with no detrimental effects on either the coal quality or the evironment. The primary objective of this project is to prove the concept in a commercial coal processing plant environment. The proof of concept tests will also include testing with a variety of coals from different regions. A further objective will be to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology.
Tewari, A.; Gokhale, A.M.; Gereman, R.M.
1999-10-08
Gravity affects microstructural evolution when a liquid phase is present during sintering. The effect of gravity on the three-dimensional coordination number distribution of tungsten grains in liquid phase sintered heavy alloy specimens is quantitatively characterized. A combination of montage serial sectioning, digital image processing, and unbiased stereological sampling procedures is used to estimate the coordination number distribution in three-dimensional microstructures. The microgravity environment decreases the mean coordination number. However, hardly any isolated grains are observed in the specimens, liquid phase sintered in a microgravity environment. The effect of microgravity on the coordination numbers mainly resides in its effect on the mean coordination number. In all specimens, there is a strong correlation between grain size and coordination number, which can be expressed as [D{sub c}/{bar D}]{sup 2} = C/C{sub 0} where C{sub 0} is the mean coordination number, {bar D} the global average size of the tungsten grains, and D{sub c} the average size of only those grains which have coordination number C.
Keeton, Charles R.; Petters, A.O.
2005-11-15
We are developing a general, unified, and rigorous analytical framework for using gravitational lensing by compact objects to test different theories of gravity beyond the weak-deflection limit. In this paper we present the formalism for computing corrections to lensing observables for static, spherically symmetric gravity theories in which the corrections to the weak-deflection limit can be expanded as a Taylor series in one parameter, namely, the gravitational radius of the lens object. We take care to derive coordinate-independent expressions and compute quantities that are directly observable. We compute series expansions for the observables that are accurate to second order in the ratio {epsilon}={theta} /{theta}{sub E} of the angle subtended by the lens's gravitational radius to the weak-deflection Einstein radius, which scales with mass as {epsilon}{proportional_to}M {sup 1/2}. The positions, magnifications, and time delays of the individual images have corrections at both first and second order in {epsilon}, as does the differential time delay between the two images. Interestingly, we find that the first-order corrections to the total magnification and centroid position vanish in all gravity theories that agree with general relativity in the weak-deflection limit, but they can remain nonzero in modified theories that disagree with general relativity in the weak-deflection limit. For the Reissner-Nordstroem metric and a related metric from heterotic string theory, our formalism reveals an intriguing connection between lensing observables and the condition for having a naked singularity, which could provide an observational method for testing the existence of such objects. We apply our formalism to the galactic black hole and predict that the corrections to the image positions are at the level of 10 {mu}arc s (microarcseconds), while the correction to the time delay is a few hundredths of a second. These corrections would be measurable today if a pulsar were found to be lensed by the galactic black hole, and they should be readily detectable with planned missions like MAXIM.
Inviscid evolution of large amplitude filaments in a uniform gravity field
Angus, J. R.; Krasheninnikov, S. I.
2014-11-15
The inviscid evolution of localized density stratifications under the influence of a uniform gravity field in a homogeneous, ambient background is studied. The fluid is assumed to be incompressible, and the stratification, or filament, is assumed to be initially isotropic and at rest. It is shown that the center of mass energy can be related to the center of mass position in a form analogous to that of a solid object in a gravity field g by introducing an effective gravity field g{sub eff}, which is less than g due to energy that goes into the background and into non-center of mass motion of the filament. During the early stages of the evolution, g{sub eff} is constant in time and can be determined from the solution of a 1D differential equation that depends on the initial, radially varying density profile of the filament. For small amplitude filaments such that ?{sub 0} ? 1, where ?{sub 0} is the relative amplitude of the filament to the background, the early stage g{sub eff} scales linearly with ?{sub 0}, but as ?{sub 0}??,?g{sub eff}?g and is thus independent of ?{sub 0}. Fully nonlinear simulations are performed for the evolution of Gaussian filaments, and it is found that the time t{sub max}, which is defined as the time for the center of mass velocity to reach its maximum value U{sub max}, occurs very soon after the constant acceleration phase and so U{sub max}?g{sub eff}(t=0)t{sub max}. The simulation results show that U{sub max}?1/t{sub max}??(?{sub 0}) for ?{sub 0} ? 1, in agreement with theory and results from previous authors, but that U{sub max} and t{sub max} both scale approximately with ?(?{sub 0}) for ?{sub 0} ? 1. The fact that U{sub max} and t{sub max} have the same scaling with ?{sub 0} for large amplitude filaments is in agreement with the theory presented in this paper.
Blakely, Richard J.; Sherrod, Brian; Weaver, Craig; Wells, Ray E.; Rohay, Alan C.
2014-06-11
Magnetic and gravity data, collected in south-central Washington near the Yakima Fold and Thrust Belt (YFTB) are used to model upper crustal structure, the extent of the late Columbia River Basalt flow named the Ice Harbor member, the vertical conduits (dikes) that the Ice Harbor erupted from, and whether the dikes are offset or affected by faulting on the Wallula Fault zone.
Oji, L. N.
2015-10-01
August 2015, scale solids from the 16H Evaporator Gravity Drain Line (GDL) to the Tank 38H were delivered to SRNL for analysis. The desired analytical goal was to identify and confirm the crystalline structure of the scale material and determine if the form of the aluminosilicate mineral was consistent with previous analysis of the scale material from the GDL.
Vacuum energy in Einstein-Gauss-Bonnet anti-de Sitter gravity
Kofinas, Georgios; Olea, Rodrigo
2006-10-15
A finite action principle for Einstein-Gauss-Bonnet anti-de Sitter gravity is achieved by supplementing the bulk Lagrangian by a suitable boundary term, whose form substantially differs in odd and even dimensions. For even dimensions, this term is given by the boundary contribution in the Euler theorem with a coupling constant fixed, demanding the spacetime to have constant (negative) curvature in the asymptotic region. For odd dimensions, the action is stationary under a boundary condition on the variation of the extrinsic curvature. A well-posed variational principle leads to an appropriate definition of energy and other conserved quantities using the Noether theorem, and to a correct description of black hole thermodynamics. In particular, this procedure assigns a nonzero energy to anti-de Sitter spacetime in all odd dimensions.
Primordial massive gravitational waves from Einstein-Chern-Simons-Weyl gravity
Myung, Yun Soo; Moon, Taeyoon E-mail: tymoon@inje.ac.kr
2014-08-01
We investigate the evolution of cosmological perturbations during de Sitter inflation in the Einstein-Chern-Simons-Weyl gravity. Primordial massive gravitational waves are composed of one scalar, two vector and four tensor circularly polarized modes. We show that the vector power spectrum decays quickly like a transversely massive vector in the superhorizon limit z?0. In this limit, the power spectrum coming from massive tensor modes decays quickly, leading to the conventional tensor power spectrum. Also, we find that in the limit of m{sup 2}?0 (keeping the Weyl-squared term only), the vector and tensor power spectra disappear. It implies that their power spectra are not gravitationally produced because they (vector and tensor) are decoupled from the expanding de Sitter background, as a result of conformal invariance.
Reconciling induced-gravity inflation in supergravity with the Planck 2013 and BICEP2 results
Pallis, C.
2014-10-01
We generalize the embedding of induced-gravity inflation beyond the no-scale Supergravity presented in ref. [1] employing two gauge singlet chiral superfields, a superpotential uniquely determined by applying a continuous R and a discrete Z{sub n} symmetries, and a logarithmic Khler potential including all the allowed terms up to fourth order in powers of the various fields. We show that, increasing slightly the prefactor (-3) encountered in the adopted Khler potential, an efficient enhancement of the resulting tensor-to-scalar ratio can be achieved rendering the predictions of the model consistent with the recent BICEP2 results, even with subplanckian excursions of the original inflaton field. The remaining inflationary observables can become compatible with the data by mildly tuning the coefficient involved in the fourth order term of the Khler potential which mixes the inflaton with the accompanying non-inflaton field. The inflaton mass is predicted to be close to 10{sup 14}GeV.
?CDM model in f(T) gravity: reconstruction, thermodynamics and stability
Salako, I.G.; Kpadonou, A.V.; Houndjo, M.J.S.; Tossa, J.; Rodrigues, M.E. E-mail: esialg@gmail.com E-mail: sthoundjo@yahoo.fr
2013-11-01
We investigate some cosmological features of the ?CDM model in the framework of the generalized teleparallel theory of gravity f(T) where T denotes the torsion scalar. Its reconstruction is performed giving rise to an integration constant Q and other input parameters according to which we point out more analysis. Thereby, we show that for some values of this constant, the first and second laws of thermodynamics can be realized in the equilibrium description, for the universe with the temperature inside the horizon equal to that at the apparent horizon. Moreover, still within these suitable values of the constant, we show that the model may be stable using the de Sitter and Power-Law cosmological solutions.
Thermodynamics of black holes in (n+1)-dimensional Einstein-Born-Infeld-dilaton gravity
Sheykhi, A.; Riazi, N.
2007-01-15
We construct a new class of (n+1)-dimensional (n{>=}3) black hole solutions in Einstein-Born-Infeld-dilaton gravity with Liouville-type potential for the dilaton field and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We find that these solutions can represent black holes, with inner and outer event horizons, an extreme black hole, or a naked singularity provided the parameters of the solutions are chosen suitably. We compute the thermodynamic quantities of the black hole solutions and find that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis and investigate the effect of dilaton on the stability of the solutions.
Gas-assisted gravity drainage (GAGD) process for improved oil recovery
Rao, Dandina N. (Baton Rouge, LA)
2012-07-10
A rapid and inexpensive process for increasing the amount of hydrocarbons (e.g., oil) produced and the rate of production from subterranean hydrocarbon-bearing reservoirs by displacing oil downwards within the oil reservoir and into an oil recovery apparatus is disclosed. The process is referred to as "gas-assisted gravity drainage" and comprises the steps of placing one or more horizontal producer wells near the bottom of a payzone (i.e., rock in which oil and gas are found in exploitable quantities) of a subterranean hydrocarbon-bearing reservoir and injecting a fluid displacer (e.g., CO.sub.2) through one or more vertical wells or horizontal wells. Pre-existing vertical wells may be used to inject the fluid displacer into the reservoir. As the fluid displacer is injected into the top portion of the reservoir, it forms a gas zone, which displaces oil and water downward towards the horizontal producer well(s).
Assessment of zero gravity effects on space worker health and safety
Not Available
1980-11-01
One objective of the study is to assess the effects of all currently known deviations from normal of medical, physiological, and biochemical parameters which appear to be due to zero gravity (zero-g) environment and to acceleration and deceleration to be experienced, as outlined in the reference Solar Power Satellite (SPS) design, by space worker. Study results include identification of possible health or safety effects on space workers - either immediate or delayed - due to the zero gravity environment and acceleration and deceleration; estimation of the probability that an individual will be adversely affected; description of the possible consequence to work efficiently in persons adversely affected; and description of the possible/probable consequences to immediate and future health of individuals exposed to this environment. A research plan, which addresses the uncertainties in current knowledge regarding the health and safety hazards to exposed SPS space workers, is presented. Although most adverse affects experienced during space flight soon disappeared upon return to the Earth's environment, there remains a definite concern for the long-term effects to SPS space workers who might spend as much as half their time in space during a possible five-year career period. The proposed 90-day up/90 day down cycle, coupled with the fact that most of the effects of weightlessness may persist throughout the flight along with the realization that recovery may occupy much of the terrestrial stay, may keep the SPS workers in a deviant physical condition or state of flux for 60 to 100% of their five-year career. (JGB)
Press Room - Press Releases - U.S. Energy Information Administration (EIA)
Gasoline and Diesel Fuel Update (EIA)
30, 2015 EIA expands monthly reporting of crude oil production with new data by API gravity New data released today by the U.S. Energy Information Administration (EIA) show that for the first nine months of 2015, the majority of crude oil produced in the Lower 48 states was light oil. As categorized by API gravity, a measure of the density of oil, the largest share of production was in the 40.1 to 45 degree API gravity range (see chart). U.S. estimated distributed and utility-scale solar PV
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
5.d - discussed at May OS face to face * Assignment given at May OS - Present draft language at June Face to Face - Completed - Subcommittee review and decide if additional...
Paul, B.C.; Honaker, R.Q.; Ho, K.
1993-12-31
Illinois Basin coal often contains a significant portion of finely dispersed pyrite. Most of the free pyrite particles exist in the fine size fractions, which are generally treated using froth flotation. An inherent problem of the froth flotation process is the inefficient treatment of middling particles containing a small amount of coal on their surface. On the other hand, gravity-based processes can effectively remove middling particles containing only a small amount of coal. Falcon Concentrators Inc. and Knelson Gold Concentrators Inc. have developed full-scale, enhanced gravity separators for the treatment of heavy minerals. This project will evaluate the potential of using these concentrators to de-ash and de-sulfurize Illinois coal fines, thus, producing coal products that meet the requirements for Phase I of the Clean Air Act. Since both continuous separators are commercially available, the results obtained in this investigation should be applicable to industrial operations.
Couch, Sean M.; Graziani, Carlo; Flocke, Norbert
2013-12-01
Self-gravity computation by multipole expansion is a common approach in problems such as core-collapse and Type Ia supernovae, where single large condensations of mass must be treated. The standard formulation of multipole self-gravity in arbitrary coordinate systems suffers from two significant sources of error, which we correct in the formulation presented in this article. The first source of error is due to the numerical approximation that effectively places grid cell mass at the central point of the cell, then computes the gravitational potential at that point, resulting in a convergence failure of the multipole expansion. We describe a new scheme that avoids this problem by computing gravitational potential at cell faces. The second source of error is due to sub-optimal choice of location for the expansion center, which results in angular power at high multipole l values in the gravitational field, requiring a highand expensivevalue of multipole cutoff l {sub max}. By introducing a global measure of angular power in the gravitational field, we show that the optimal coordinate for the expansion is the square-density-weighted mean location. We subject our new multipole self-gravity algorithm, implemented in the FLASH simulation framework, to two rigorous test problems: MacLaurin spheroids for which exact analytic solutions are known, and core-collapse supernovae. We show that key observables of the core-collapse simulations, particularly shock expansion, proto-neutron star motion, and momentum conservation, are extremely sensitive to the accuracy of the multipole gravity, and the accuracy of their computation is greatly improved by our reformulated solver.
David S. Schechter
1998-04-30
The objective is to assess the economic feasibility of CO2 flooding of the naturally fractured Straberry Trend Area in west Texas. Research is being conducted in the extensive characterization of the reservoirs, the experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, the analytical and numerical simulation of Spraberry reservoirs, and the experimental investigations on CO2 gravity drainage in Spraberry whole cores.
Detection method and observed data of high-energy gamma rays under the influence of quantum gravity
Kifune, T.
2014-05-20
The interaction of high-energy particles affected by quantum gravity is argued from the experimental viewpoint of raising a question, 'our detection method for high-energy ?-rays supplies trustworthy observation data and we are now seeing the true image of the universe through high-energy ?-rays?' The modified dispersion relation (MDR) for particles' energy and momentum is applied to the equation of energy-momentum conservation in particle reactions, to study the restriction imposed on the kinematic state of high-energy particles by the Lorentz invariance violation (LIV) due to quantum gravity, as a function of the incident particle energy of the reaction. The result suggests that the interaction utilized for ?-ray detection is not free from the effect of quantum gravity when ?-ray energy is higher than 10{sup 13} ? 10{sup 17} eV depending on models of MDR. Discussion is presented on the prospect of finding clear evidence of the LIV effect from ?-ray observations, as well as on the radiation and propagation mechanism of ?-rays under the influence of the LIV effect.
Rouhani, S. Zia (Idaho Falls, ID)
1996-01-01
In most electrochemical batteries which generate electricity through the reaction of a battery electrode with an electrolyte solution, the chemical composition, and thus the weight and density, of the electrode changes as the battery discharges. The invention measures a parameter of the battery which changes as the weight of the electrode changes as the battery discharges and relates that parameter to the value of the parameter when the battery is fully charged and when the battery is functionally discharged to determine the state-of-charge of the battery at the time the parameter is measured. In one embodiment, the weight of a battery electrode or electrode unit is measured to determine the state-of-charge. In other embodiments, where a battery electrode is located away from the geometrical center of the battery, the position of the center of gravity of the battery or shift in the position of the center of gravity of the battery is measured (the position of the center of gravity changes with the change in weight of the electrode) and indicates the state-of-charge of the battery.
Rouhani, S.Z.
1996-12-03
In most electrochemical batteries which generate electricity through the reaction of a battery electrode with an electrolyte solution, the chemical composition, and thus the weight and density, of the electrode changes as the battery discharges. The invention measures a parameter of the battery which changes as the weight of the electrode changes as the battery discharges and relates that parameter to the value of the parameter when the battery is fully charged and when the battery is functionally discharged to determine the state-of-charge of the battery at the time the parameter is measured. In one embodiment, the weight of a battery electrode or electrode unit is measured to determine the state-of-charge. In other embodiments, where a battery electrode is located away from the geometrical center of the battery, the position of the center of gravity of the battery or shift in the position of the center of gravity of the battery is measured (the position of the center of gravity changes with the change in weight of the electrode) and indicates the state-of-charge of the battery. 35 figs.
Guo, Y.; Keller, J.; LaCava, W.
2012-09-01
This computational work investigates planetary gear load sharing of three-mount suspension wind turbine gearboxes. A three dimensional multibody dynamic model is established, including gravity, bending moments, fluctuating mesh stiffness, nonlinear tooth contact, and bearing clearance. A flexible main shaft, planetary carrier, housing, and gear shafts are modeled using reduced degrees-of-freedom through modal compensation. This drivetrain model is validated against the experimental data of Gearbox Reliability Collaborative for gearbox internal loads. Planet load sharing is a combined effect of gravity, bending moment, bearing clearance, and input torque. Influences of each of these parameters and their combined effects on the resulting planet load sharing are investigated. Bending moments and gravity induce fundamental excitations in the rotating carrier frame, which can increase gearbox internal loads and disturb load sharing. Clearance in carrier bearings reduces the bearing load carrying capacity and thus the bending moment from the rotor can be transmitted into gear meshes. With bearing clearance, the bending moment can cause tooth micropitting and can induce planet bearing fatigue, leading to reduced gearbox life. Planet bearings are susceptible to skidding at low input torque.
Induced-gravity inflation in no-scale supergravity and beyond
Pallis, C.
2014-08-01
Supersymmetric versions of induced-gravity inflation are formulated within Supergravity (SUGRA) employing two gauge singlet chiral superfields. The proposed superpotential is uniquely determined by applying a continuous R and a discrete Z{sub n} symmetry. We select two types of logarithmic Khler potentials, one associated with a no-scale-type SU(2,1)/SU(2)נU(1){sub R}Z{sub n} Khler manifold and one more generic. In both cases, imposing a lower bound on the parameter c{sub R} involved in the coupling between the inflaton and the Ricci scalar curvature e.g. c{sub R}?>76,105,310 for n=2,3 and 6 respectively , inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity. In the case of no-scale SUGRA we show that, for every n, the inflationary observables remain unchanged and in agreement with the current data while the inflaton mass is predicted to be 310{sup 13} GeV. Beyond no-scale SUGRA the inflationary observables depend mildly on n and crucially on the coefficient involved in the fourth order term of the Khler potential which mixes the inflaton with the accompanying non-inflaton field.
Couplings between Chern-Simons gravities and 2p-branes
Miskovic, Olivera; Zanelli, Jorge
2009-08-15
The interaction between Chern-Simons (CS) theories and localized external sources (2p-branes) is analyzed. This interaction generalizes the minimal coupling between a point charge (0-brane) and a gauge connection. The external currents that define the 2p branes are covariantly constant (D-2p-1)-forms coupled to (2p-1) CS forms. The general expression for the sources--charged with respect to the corresponding gauge algebra--is presented, focusing on two special cases: 0-branes and (D-3)-branes. In any dimension, 0-branes are constructed as topological defects produced by a surface deficit of (D-2)-sphere in anti-de Sitter space, and they are not constant curvature spaces for D>3. They correspond to dimensionally continued black holes with negative mass. On the other hand, in the case of CS (super) gravities, the (D-3)-branes are naked conical singularities (topological defects) obtained by identification of points with a Killing vector. In 2+1 dimensions, extremal spinning branes of this type are Bogomol'nyi-Prasad-Sommerfield states. Stable (D-3)-branes are shown to exist also in higher dimensions, as well. Classical field equations are also discussed, and in the presence of sources there is a large number of inequivalent and disconnected sectors in solution space.
Black holes in an asymptotically safe gravity theory with higher derivatives
Cai, Yi-Fu; Easson, Damien A. E-mail: easson@asu.edu
2010-09-01
We present a class of spherically symmetric vacuum solutions to an asymptotically safe theory of gravity containing high-derivative terms. We find quantum corrected Schwarzschild-(anti)-de Sitter solutions with running gravitational coupling parameters. The evolution of the couplings is determined by their corresponding renormalization group flow equations. These black holes exhibit properties of a classical Schwarzschild solution at large length scales. At the center, the metric factor remains smooth but the curvature singularity, while softened by the quantum corrections, persists. The solutions have an outer event horizon and an inner Cauchy horizon which equate when the physical mass decreases to a critical value. Super-extremal solutions with masses below the critical value correspond to naked singularities. The Hawking temperature of the black hole vanishes when the physical mass reaches the critical value. Hence, the black holes in the asymptotically safe gravitational theory never completely evaporate. For appropriate values of the parameters such stable black hole remnants make excellent dark matter candidates.
Smith, L.B.; Durney, T.E. Jr.
1990-10-24
Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up the millions of tons of coal fines in refuse piles and ponds. Work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. The primary objective of this project is to prove the concept in a commercial coal processing plant environment. The proof of concept tests will include testing with a variety of coals from different regions. A further objective will be to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology. To supply some perspective on the ability of the new centrifuges to successfully dry a variety of coals from various coal fields, it was decided that coals ranging from very fine to course size consists and with both low and high inherent moistures would be tested. Coals tested include: Pittsburgh no. 8 seam (Pennsylvania), Pittsburgh no. 8 seam (West Virginia), and Blue Creek Seam (Alabama). 6 figs.
Barnhart, Kevin Scott
2013-10-01
We proposed to customize emerging in situ geophysical monitoring technology to generate time-series data during sporadic rain events in a semi-arid region. Electrodes were to be connected to wireless %5Cnodes%22 which can be left in the eld for many months. Embedded software would then increase sampling frequency during periods of rainfall. We hypothesized that this contrast between no-volume ow in karst passageways dur- ing dry periods and partial- or saturated-volume ow during a rain event is detectable by these Wireless Sensor Network (WSN) geophysical nodes, we call this a Wireless Resistivity Network (WRN). The development of new methodologies to characterize semi-arid karst hydrology is intended to augment Sandia National Laboratorys mission to lead e orts in energy technologies, waste disposal and climate security by helping to identify safe and secure regions and those that are at risk. Development and initial eld testing identi ed technological barriers to using WRNs for identifying semi-arid karst, exposing R&D which can be targeted in the future. Gravity, seismic, and resis- tivity surveys elucidated how each technique might e ectively be used to characterize semi-arid karst. This research brings to light the importance and challenges with char- acterizing semi-arid karst through a multi-method geophysical study. As there have been very few studies with this emphasis, this study has expanded the body of practical experience needed to protect the nations water and energy security interests.
Modified Eddington-inspired-Born-Infeld gravity with a trace term
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chen, Che -Yu; Bouhmadi-López, Mariam; Chen, Pisin
2016-01-22
In this study, a modified Eddington-inspired-Born-Infeld (EiBI) theory with a pure trace term gμνR being added to the determinantal action is analysed from a cosmological point of view. It corresponds to the most general action constructed from a rank two tensor that contains up to first order terms in curvature. This term can equally be seen as a conformal factor multiplying the metric gμν . This very interesting type of amendment has not been considered within the Palatini formalism despite the large amount of works on the Born-Infeld-inspired theory of gravity. This model can provide smooth bouncing solutions which weremore » not allowed in the EiBI model for the same EiBI coupling. Most interestingly, for a radiation filled universe there are some regions of the parameter space that can naturally lead to a de Sitter inflationary stage without the need of any exotic matter field. Finally, in this model we discover a new type of cosmic “quasi-sudden” singularity, where the cosmic time derivative of the Hubble rate becomes very large but finite at a finite cosmic time.« less
Distorting general relativity: gravity's rainbow and f(R) theories at work
Garattini, Remo
2013-06-01
We compute the Zero Point Energy in a spherically symmetric background combining the high energy distortion of Gravity's Rainbow with the modification induced by a f(R) theory. Here f(R) is a generic analytic function of the Ricci curvature scalar R in 4D and in 3D. The explicit calculation is performed for a Schwarzschild metric. Due to the spherically symmetric property of the Schwarzschild metric we can compare the effects of the modification induced by a f(R) theory in 4D and in 3D. We find that the final effect of the combined theory is to have finite quantities that shift the Zero Point Energy. In this context we setup a Sturm-Liouville problem with the cosmological constant considered as the associated eigenvalue. The eigenvalue equation is a reformulation of the Wheeler-DeWitt equation which is analyzed by means of a variational approach based on gaussian trial functionals. With the help of a canonical decomposition, we find that the relevant contribution to one loop is given by the graviton quantum fluctuations around the given background. A final discussion on the connection of our result with the observed cosmological constant is also reported.
Reconciling induced-gravity inflation in supergravity with the Planck 2013 & BICEP2 results
Pallis, C.
2014-10-23
We generalize the embedding of induced-gravity inflation beyond the no-scale Supergravity presented in ref. http://dx.doi.org/10.1088/1475-7516/2014/08/057 employing two gauge singlet chiral superfields, a superpotential uniquely determined by applying a continuous R and a discrete ℤ{sub n} symmetries, and a logarithmic Kähler potential including all the allowed terms up to fourth order in powers of the various fields. We show that, increasing slightly the prefactor (−3) encountered in the adopted Kähler potential, an efficient enhancement of the resulting tensor-to-scalar ratio can be achieved rendering the predictions of the model consistent with the recent BICEP2 results, even with subplanckian excursions of the original inflaton field. The remaining inflationary observables can become compatible with the data by mildly tuning the coefficient involved in the fourth order term of the Kähler potential which mixes the inflaton with the accompanying non-inflaton field. The inflaton mass is predicted to be close to 10{sup 14} GeV.
On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs
Faybishenko, B.; Bodvarsson, G.S.; Salve, R.
2002-04-01
To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Tonopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility, using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variations of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff, incorporating the time dependent processes of water redistribution in the fracture-matrix system.
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
402 Crude Oil Refiner Acquisition Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 1A - Domestic First Purchases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - from selected States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 - by API gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 - for selected crude streams . . . . . . . . . . . . . . . . . . . . . . . . . 19 - Imports F.O.B. Costs . . . . . . .
This Week In Petroleum Summary Printer-Friendly Version
Gasoline and Diesel Fuel Update (EIA)
34.2, the highest in the country last year. (API gravity is an inverse measure of the density of a petroleum liquid relative to water. The higher the number, the lower the density...
U.S. Crude Oil Production to 2025: Updated Projection of Crude...
U.S. Energy Information Administration (EIA) Indexed Site
... Consistent with recent classification decisions from the U.S. Department of Commerce, Bureau of Industry and Security, 4 minimal processing of crude streams with an API gravity of ...
Marr, W.A.; Fairhurst, C.E.
1999-07-01
The purpose of the symposium was to highlight recent developments in nondestructive and automated testing for soil and rock properties. Speakers present results of recent research in these areas that have practical application for the rapid and economical testing of soil and rock. Authors were encouraged to identify which testing equipment and methods have sufficient practical application to warrant standards development.
Field instrumentation for soil and rock. ASTM special technical publication 1358
Durham, G.N.; Marr, W.A.
1999-07-01
Papers are arranged under the following topical sections: Instrumentation associated with soil structure interaction; Instrumentation support construction activities; Instrumentation to monitor landfills; Instrumentation for monitoring settlement and stability; Data acquisition and data management; and Instrumentation for measuring physical properties in the field. Papers within scope have been processed separately for inclusion on the data base.
Observation of Cleavage Fracture after Substantial Dimple Rupture in ASTM A710 Steel
Reuter, Walter Graham; Lloyd, Wilson Randolph
2000-07-01
A major concern often arising in structural integrity predictions is the possibility that low-energy brittle fracture could result as a consequence of cleavage either under normal operating or design accident conditions. This can be especially troublesome when the leak-before-break (LBB) approach shows an additional safety margin of the design. For LBB to be applicable, the fracture process must remain ductile (dimple rupture), and not change to cleavage. The American Society for Mechanical Engineers Boiler and Pressure Vessel Code (Code) provides guidelines for avoiding cleavage fracture for Code-accepted materials. Experimental results for a non-Code steel are provided, and show that cleavage may occur for a thickness under16 mm (where the code suggests it will not) after stable crack growth (?a) of up to 20 mm. This work is still in progress; test results are provided along with possible reasons for the mode transition, but complete explanations are still being developed.
Smith, L.B.; Durney, T.
1991-01-01
The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer's systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)
Knight, Bill; Schechter, David S.
2002-07-26
The goal of this project was to assess the economic feasibility of CO2 flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. This provides results of the final year of the six-year project for each of the four areas.
Schechter, D.S.
1999-02-03
The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and, (4) experimental investigations on CO2 gravity drainage in Spraberry whole cores. This report provides results of the third year of the five-year project for each of the four areas including a status report of field activities leading up to injection of CO2.
COLLISIONS BETWEEN GRAVITY-DOMINATED BODIES. I. OUTCOME REGIMES AND SCALING LAWS
Leinhardt, Zoee M.; Stewart, Sarah T. E-mail: sstewart@eps.harvard.edu
2012-01-20
Collisions are the core agent of planet formation. In this work, we derive an analytic description of the dynamical outcome for any collision between gravity-dominated bodies. We conduct high-resolution simulations of collisions between planetesimals; the results are used to isolate the effects of different impact parameters on collision outcome. During growth from planetesimals to planets, collision outcomes span multiple regimes: cratering, merging, disruption, super-catastrophic disruption, and hit-and-run events. We derive equations (scaling laws) to demarcate the transition between collision regimes and to describe the size and velocity distributions of the post-collision bodies. The scaling laws are used to calculate maps of collision outcomes as a function of mass ratio, impact angle, and impact velocity, and we discuss the implications of the probability of each collision regime during planet formation. Collision outcomes are described in terms of the impact conditions and the catastrophic disruption criteria, Q*{sub RD}-the specific energy required to disperse half the total colliding mass. All planet formation and collisional evolution studies have assumed that catastrophic disruption follows pure energy scaling; however, we find that catastrophic disruption follows nearly pure momentum scaling. As a result, Q*{sub RD} is strongly dependent on the impact velocity and projectile-to-target mass ratio in addition to the total mass and impact angle. To account for the impact angle, we derive the interacting mass fraction of the projectile; the outcome of a collision is dependent on the kinetic energy of the interacting mass rather than the kinetic energy of the total mass. We also introduce a new material parameter, c*, that defines the catastrophic disruption criteria between equal-mass bodies in units of the specific gravitational binding energy. For a diverse range of planetesimal compositions and internal structures, c* has a value of 5 {+-} 2; whereas for strengthless planets, we find c* = 1.9 {+-} 0.3. We refer to the catastrophic disruption criteria for equal-mass bodies as the principal disruption curve, which is used as the reference value in the calculation of Q*{sub RD} for any collision scenario. The analytic collision model presented in this work will significantly improve the physics of collisions in numerical simulations of planet formation and collisional evolution.
Jacobson, R. A.
2014-11-01
French et al. determined the orbits of the Uranian rings, the orientation of the pole of Uranus, and the gravity harmonics of Uranus from Earth-based and Voyager ring occultations. Jacobson et al. determined the orbits of the Uranian satellites and the masses of Uranus and its satellites from Earth-based astrometry and observations acquired with the Voyager 2 spacecraft; they used the gravity harmonics and pole from French et al. Jacobson and Rush reconstructed the Voyager 2 trajectory and redetermined the Uranian system gravity parameters, satellite orbits, and ring orbits in a combined analysis of the data used previously augmented with additional Earth-based astrometry. Here we report on an extension of that work that incorporates additional astrometry and ring occultations together with improved data processing techniques.
Paul, B.C.; Honaker, R.Q.
1994-09-01
It is well known that froth flotation is inefficient for treating fine coal fractions containing a significant portion of middling particles. On the other hand, gravity-based processes can effectively remove middling particles containing only a small amount of coal. Falcon Concentrators Inc. and Knelson Gold Concentrators Inc. have developed full-scale, enhanced gravity separators for the treatment of heavy minerals. This project is evaluating the potential of using these concentrators to treat Illinois Basin coal fines. During this reporting period, -28 mesh run-of-mine Illinois No. 5 and No. 6 coal samples were processed using a continuous Falcon concentrator having a 10-inch bowl diameter. For the Illinois No. 5 coal sample, the ash content was reduced in the 100 {times} 325 mesh size fraction from about 18% to 8% while achieving a high combustible recovery value of nearly 97%. In addition, the total sulfur content was substantially decreased from 2.6% to 1.7%. Similar results were obtained from the treatment of the Illinois No. 6 coal sample where ash rejections ranged from 40%-70% for a 28 {times} 325 mesh feed having 7% ash. Combustible recovery values from these tests were greater than 87% while treating mass feed rates between 1 to 2 tons/hour. A parametric study found that lower feed solids contents provided marginally lower product ash and total sulfur contents while feed rate and bowl speed appeared to have no significant effect over the range of values tested.
Arctic Energy Technology Development Laboratory (Part 3)
See OSTI ID Number 960443
2008-12-31
Various laboratory tests were carried at the R & D facility of BJ Services in Tomball, TX with BJ Services staff to predict and evaluate the performance of the Ceramicrete slurry for its effective use in permafrost cementing operations. Although other standards such as those of the American Standard for Testing Materials (ASTM) and Construction Specification Institute (CSI) exist, all these tests were standardized by the API. A summary of the tests traditionally used in the cement slurry design as well as the API tests reference document are provided in Table 7. All of these tests were performed within the scope of this research to evaluate properties of the Ceramicrete.
Influence of strontium addition on the mechanical properties of gravity cast Mg-3Al-3Sn alloy
Germen, Gl?ah ?evik, Hseyin; Kurnaz, S. Can
2013-12-16
In this study, the effect of strontium (0.01, 0.1, 0.5, 1 wt%) addition on the microstructure and mechanical properties of the gravity cast Mg-3Al-3Sn alloy were investigated. X-ray diffractometry revealed that the main phases are ??Mg, ??Mg{sub 17}Al{sub 12} and Mg{sub 2}Sn in the Mg-3Al-3Sn alloy. With addition The tensile testing results showed that the yield and ultimate tensile strength and elongation of Mg-3Al-3Sn alloy increased by adding Sr up to 0.1 wt.% and then is gradually decreased with the addition of more alloying element.
Haro, Jaume; Amors, Jaume E-mail: jaume.amoros@upc.edu
2014-12-01
We consider the matter bounce scenario in F(T) gravity and Loop Quantum Cosmology (LQC) for phenomenological potentials that at early times provide a nearly matter dominated Universe in the contracting phase, having a reheating mechanism in the expanding or contracting phase, i.e., being able to release the energy of the scalar field creating particles that thermalize in order to match with the hot Friedmann Universe, and finally at late times leading to the current cosmic acceleration. For these potentials, numerically solving the dynamical perturbation equations we have seen that, for the particular F(T) model that we will name teleparallel version of LQC, and whose modified Friedmann equation coincides with the corresponding one in holonomy corrected LQC when one deals with the flat Friedmann-Lematre-Robertson-Walker (FLRW) geometry, the corresponding equations obtained from the well-know perturbed equations in F(T) gravity lead to theoretical results that fit well with current observational data. More precisely, in this teleparallel version of LQC there is a set of solutions which leads to theoretical results that match correctly with last BICEP2 data, and there is another set whose theoretical results fit well with Planck's experimental data. On the other hand, in the standard holonomy corrected LQC, using the perturbed equations obtained replacing the Ashtekar connection by a suitable sinus function and inserting some counter-terms in order to preserve the algebra of constrains, the theoretical value of the tensor/scalar ratio is smaller than in the teleparallel version, which means that there is always a set of solutions that matches with Planck's data, but for some potentials BICEP2 experimental results disfavours holonomy corrected LQC.
Maeda, Hideki
2006-05-15
We give a model of the higher-dimensional spherically symmetric gravitational collapse of a dust cloud including the perturbative effects of quantum gravity. The n({>=}5)-dimensional action with the Gauss-Bonnet term for gravity is considered and a simple formulation of the basic equations is given for the spacetime M{approx_equal}M{sup 2}xK{sup n-2} with a perfect fluid and a cosmological constant. This is a generalization of the Misner-Sharp formalism of the four-dimensional spherically symmetric spacetime with a perfect fluid in general relativity. The whole picture and the final fate of the gravitational collapse of a dust cloud differ greatly between the cases with n=5 and n{>=}6. There are two families of solutions, which we call plus-branch and the minus-branch solutions. A plus-branch solution can be attached to the outside vacuum region which is asymptotically anti-de Sitter in spite of the absence of a cosmological constant. Bounce inevitably occurs in the plus-branch solution for n{>=}6, and consequently singularities cannot be formed. Since there is no trapped surface in the plus-branch solution, the singularity formed in the case of n=5 must be naked. On the other hand, a minus-branch solution can be attached to the outside asymptotically flat vacuum region. We show that naked singularities are massless for n{>=}6, while massive naked singularities are possible for n=5. In the homogeneous collapse represented by the flat Friedmann-Robertson-Walker solution, the singularity formed is spacelike for n{>=}6, while it is ingoing-null for n=5. In the inhomogeneous collapse with smooth initial data, the strong cosmic censorship hypothesis holds for n{>=}10 and for n=9 depending on the parameters in the initial data, while a naked singularity is always formed for 5{<=}n{<=}8. These naked singularities can be globally naked when the initial surface radius of the dust cloud is fine-tuned, and then the weak cosmic censorship hypothesis is violated.
Hansen, Jakob; Yeom, Dong-han
2015-09-07
We investigate the relation between the existence of mass inflation and model parameters of string-inspired gravity models. In order to cover various models, we investigate a Brans-Dicke theory that is coupled to a U(1) gauge field. By tuning a model parameter that decides the coupling between the Brans-Dicke field and the electromagnetic field, we can make both of models such that the Brans-Dicke field is biased toward strong or weak coupling directions after gravitational collapses. We observe that as long as the Brans-Dicke field is biased toward any (strong or weak) directions, there is no Cauchy horizon and no mass inflation. Therefore, we conclude that to induce a Cauchy horizon and mass inflation inside a charged black hole, either there is no bias of the Brans-Dicke field as well as no Brans-Dicke hair outside the horizon or such a biased Brans-Dicke field should be well trapped and controlled by a potential.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Padrino-Inciarte, Juan Carlos; Ma, Xia; VanderHeyden, W. Brian; Zhang, Duan Zhong
2016-01-01
General ensemble phase averaged equations for multiphase flows have been specialized for the simulation of the steam assisted gravity drainage (SAGD) process. In the average momentum equation, fluid-solid and fluid-fluid viscous interactions are represented by separate force terms. This equation has a form similar to that of Darcy’s law for multiphase flow but augmented by the fluid-fluid viscous forces. Models for these fluid-fluid interactions are suggested and implemented into the numerical code CartaBlanca. Numerical results indicate that the model captures the main features of the multiphase flow in the SAGD process, but the detailed features, such as plumes are missed.more » We find that viscous coupling among the fluid phases is important. Advection time scales for the different fluids differ by several orders of magnitude because of vast viscosity differences. Numerically resolving all of these time scales is time consuming. To address this problem, we introduce a steam surrogate approximation to increase the steam advection time scale, while keeping the mass and energy fluxes well approximated. This approximation leads to about a 40-fold speed-up in execution speed of the numerical calculations at the cost of a few percent error in the relevant quantities.« less
Padrino-Inciarte, Juan Carlos; Ma, Xia; VanderHeyden, W. Brian; Zhang, Duan Zhong
2016-01-01
General ensemble phase averaged equations for multiphase flows have been specialized for the simulation of the steam assisted gravity drainage (SAGD) process. In the average momentum equation, fluid-solid and fluid-fluid viscous interactions are represented by separate force terms. This equation has a form similar to that of Darcys law for multiphase flow but augmented by the fluid-fluid viscous forces. Models for these fluid-fluid interactions are suggested and implemented into the numerical code CartaBlanca. Numerical results indicate that the model captures the main features of the multiphase flow in the SAGD process, but the detailed features, such as plumes are missed. We find that viscous coupling among the fluid phases is important. Advection time scales for the different fluids differ by several orders of magnitude because of vast viscosity differences. Numerically resolving all of these time scales is time consuming. To address this problem, we introduce a steam surrogate approximation to increase the steam advection time scale, while keeping the mass and energy fluxes well approximated. This approximation leads to about a 40-fold speed-up in execution speed of the numerical calculations at the cost of a few percent error in the relevant quantities.
Lebach, D. E.; Ratner, M. I.; Shapiro, I. I.; Bartel, N.; Bietenholz, M. F.; Lederman, J. I.; Ransom, R. R.; Campbell, R. M.; Gordon, D.
2012-07-01
When very long baseline interferometry (VLBI) observations are used to determine the position or motion of a radio source relative to reference sources nearby on the sky, the astrometric information is usually obtained via (1) phase-referenced maps or (2) parametric model fits to measured fringe phases or multiband delays. In this paper, we describe a 'merged' analysis technique which combines some of the most important advantages of these other two approaches. In particular, our merged technique combines the superior model-correction capabilities of parametric model fits with the ability of phase-referenced maps to yield astrometric measurements of sources that are too weak to be used in parametric model fits. We compare the results from this merged technique with the results from phase-referenced maps and from parametric model fits in the analysis of astrometric VLBI observations of the radio-bright star IM Pegasi (HR 8703) and the radio source B2252+172 nearby on the sky. In these studies we use central-core components of radio sources 3C 454.3 and B2250+194 as our positional references. We obtain astrometric results for IM Peg with our merged technique even when the source is too weak to be used in parametric model fits, and we find that our merged technique yields astrometric results superior to the phase-referenced mapping technique. We used our merged technique to estimate the proper motion and other astrometric parameters of IM Peg in support of the NASA/Stanford Gravity Probe B mission.
Lee, S.I.; No, H.C.; Bang, Y.S.; Kim, H.J.
1996-10-01
The objective of the present work is to improve the analysis capability of RELAP5/MOD3.1 on the direct contact condensation in the core makeup tank (CMT) of passive high-pressure injection system (PHPIS) in the CARR Passive Reactor (CP-1300). The gravity-driven injection experiment is conducted by using a small scale test facility to identify the parameters having significant effects on the gravity-driven injection and the major condensation modes. It turns out that the larger the water subcooling is, the more initiation of injection is delayed, and the sparger and the natural circulation of the hot water from the steam generator accelerate the gravity-driven injection. The condensation modes are divided into three modes: sonic jet, subsonic jet, and steam cavity. RELAP5/MOD3.1 is chosen to evaluate the cod predictability on the direct contact condensation in the CMT. It is found that the predictions of MOD3.1 are in better agreement with the experimental data than those of MOD3.0. From the nodalization study of the test section, the 1-node model shows better agreement with the experimental data than the multi-node models. RELAP5/MOD3.1 identifies the flow regime of the test section as vertical stratification. However, the flow regime observed in the experiment is the subsonic jet with the bubble having the vertical cone shape. To accurately predict the direct contact condensation in the CMT with RELAP5/MOD3.1, it is essential that a new set of the interfacial heat transfer coefficients and a new flow regime map for direct contact condensation in the CMT be developed.
SIMPJ21541055: A NEW LOW-GRAVITY L4? BROWN DWARF CANDIDATE MEMBER OF THE ARGUS ASSOCIATION
Gagn, Jonathan; Lafrenire, David; Doyon, Ren; Artigau, tienne; Malo, Lison; Robert, Jasmin; Nadeau, Daniel
2014-09-01
We present SIMPJ215434541055308, a new L4? brown dwarf identified in the SIMP survey that displays signs of low gravity in its near-infrared spectrum. Using BANYAN II, we show that it is a candidate member of the Argus association, albeit with a 21% probability that it is a contaminant from the field. Measurements of radial velocity and parallax will be needed to verify its membership. If it is a member of Argus (age 30-50Myr), then this object would have a planetary mass of 10 0.5M {sub Jup}.
Smith, L.B.; Durney, T.
1991-12-31
The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer`s systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)
Schechter, D.S.
1997-12-01
The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding in the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the first year of the five-year project for each of the four areas.
Quantum gravity slows inflation
Tsamis, N.C. |; Woodard, R.P.
1996-02-01
We consider the quantum gravitational back-reaction on an initially inflating, homogeneous and isotropic universe whose topology is T{sup 3} {times} {Re}. Although there is no secular effect at one loop, an explicit calculation shows that two-loop processes act to slow the rate of expansion by an amount which becomes non-pertubatively large at late times. By exploiting Feynman`s tree theorem we show that all higher loops act in the same sense. 18 refs., 1 fig.
Coal liquefaction process wherein jet fuel, diesel fuel and/or ASTM No. 2 fuel oil is recovered
Bauman, Richard F.; Ryan, Daniel F.
1982-01-01
An improved process for the liquefaction of coal and similar solid carbonaceous materials wherein a hydrogen donor solvent or diluent derived from the solid carbonaceous material is used to form a slurry of the solid carbonaceous material and wherein the naphthenic components from the solvent or diluent fraction are separated and used as jet fuel components. The extraction increases the relative concentration of hydroaromatic (hydrogen donor) components and as a result reduces the gas yield during liquefaction and decreases hydrogen consumption during said liquefaction. The hydrogenation severity can be controlled to increase the yield of naphthenic components and hence the yield of jet fuel and in a preferred embodiment jet fuel yield is maximized while at the same time maintaining solvent balance.
McDonald, P.
1998-06-01
The objective of the Spraberry CO{sub 2} pilot project is to determine the technical and economic feasibility of continuous CO{sub 2} injection in the naturally fractured reservoirs of the Spraberry Trend. In order to describe, understand, and model CO{sub 2} flooding in the naturally fractured Spraberry reservoirs, characterization of the fracture system is a must. Additional reservoir characterization was based on horizontal coring in the second year of the project. In addition to characterization of natural fractures, horizontal coring has confirmed a previously developed rock model for describing the Spraberry Trend shaly sands. A better method for identifying Spraberry pay zones has been verified. The authors have completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. The authors have completed extensive imbibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. The authors have also made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. They have completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix.
Portals 4 network API definition and performance measurement
Brightwell, R. B.
2012-03-01
Portals is a low-level network programming interface for distributed memory massively parallel computing systems designed by Sandia, UNM, and Intel. Portals has been designed to provide high message rates and to provide the flexibility to support a variety of higher-level communication paradigms. This project developed and analyzed an implementation of Portals using shared memory in order to measure and understand the impact of using general-purpose compute cores to handle network protocol processing functions. The goal of this study was to evaluate an approach to high-performance networking software design and hardware support that would enable important DOE modeling and simulation applications to perform well and to provide valuable input to Intel so they can make informed decisions about future network software and hardware products that impact DOE applications.
Home Energy Score API User: United Illuminating Company and Eversource...
Eversource, administering conservation, and load management programs funded by the Connecticut Energy Efficiency Fund, are Home Energy Score Partners. Home Energy Solutions...
Energy API and dataset overview | OpenEI Community
2012 - 14:36 cleanweb hackathon resource webinar Today, Ian Kalin, a presidential innovation fellow, and the OpenEI team recorded an "energy resource" overview for developers of...
Home Energy Score API User: United Illuminating Company and Eversource
Broader source: Energy.gov [DOE]
The United Illuminating Company and Eversource, administering conservation, and load management programs funded by the Connecticut Energy Efficiency Fund, are Home Energy Score Partners. Home...
Schechter, D.S.
1998-07-01
The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the second year of the five-year project for each of the four areas. In the first area, the author has completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. In the second area, the author has completed extensive inhibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. In the third area, the author has made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. In the fourth area, the author has completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix. The final three years of this project involves implementation of the CO{sub 2} pilot. Up to twelve new wells are planned in the pilot area; water injection wells to contain the CO{sub 2}, three production wells to monitor performance of CO{sub 2}, CO{sub 2} injection wells including one horizontal injection well and logging observation wells to monitor CO{sub 2} flood fronts. Results of drilling these wells will be forthcoming.
Barnes, Jason W.; Van Eyken, Julian C.; Jackson, Brian K.; Ciardi, David R.
2013-09-01
PTFO 8-8695b represents the first transiting exoplanet candidate orbiting a pre-main-sequence star (van Eyken et al. 2012, ApJ, 755, 42). We find that the unusual lightcurve shapes of PTFO 8-8695 can be explained by transits of a planet across an oblate, gravity-darkened stellar disk. We develop a theoretical framework for understanding precession of a planetary orbit's ascending node for the case when the stellar rotational angular momentum and the planetary orbital angular momentum are comparable in magnitude. We then implement those ideas to simultaneously and self-consistently fit two separate lightcurves observed in 2009 December and 2010 December. Our two self-consistent fits yield M{sub p} = 3.0 M{sub Jup} and M{sub p} = 3.6 M{sub Jup} for assumed stellar masses of M{sub *} = 0.34 M{sub Sun} and M{sub *} = 0.44 M{sub Sun} respectively. The two fits have precession periods of 293 days and 581 days. These mass determinations (consistent with previous upper limits) along with the strength of the gravity-darkened precessing model together validate PTFO 8-8695b as just the second hot Jupiter known to orbit an M-dwarf. Our fits show a high degree of spin-orbit misalignment in the PTFO 8-8695 system: 69 Degree-Sign {+-} 2 Degree-Sign or 73. Degree-Sign 1 {+-} 0. Degree-Sign 5, in the two cases. The large misalignment is consistent with the hypothesis that planets become hot Jupiters with random orbital plane alignments early in a system's lifetime. We predict that as a result of the highly misaligned, precessing system, the transits should disappear for months at a time over the course of the system's precession period. The precessing, gravity-darkened model also predicts other observable effects: changing orbit inclination that could be detected by radial velocity observations, changing stellar inclination that would manifest as varying vsin i, changing projected spin-orbit alignment that could be seen by the Rossiter-McLaughlin effect, changing transit shapes over the course of the precession, and differing lightcurves as a function of wavelength. Our measured planet radii of 1.64 R{sub Jup} and 1.68 R{sub Jup} in each case are consistent with a young, hydrogen-dominated planet that results from a ''hot-start'' formation mechanism.
U.S. Energy Information Administration (EIA) Indexed Site
Percentages of Total Imported Crude Oil by API Gravity" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Percentages of Total Imported Crude Oil by API Gravity",7,"Monthly","12/2015","1/15/1983" ,"Release Date:","3/1/2016" ,"Next Release Date:","4/1/2016"
U.S. Energy Information Administration (EIA) Indexed Site
API Gravity" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","F.O.B. Costs of Imported Crude Oil by API Gravity",7,"Monthly","12/2015","1/15/1983" ,"Release Date:","3/1/2016" ,"Next Release Date:","4/1/2016" ,"Excel File
U.S. Energy Information Administration (EIA) Indexed Site
API Gravity" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Landed Costs of Imported Crude by API Gravity",7,"Monthly","12/2015","1/15/1983" ,"Release Date:","3/1/2016" ,"Next Release Date:","4/1/2016" ,"Excel File
Heckman, Tracy; Schechter, David S.
2000-04-11
The overall goal of this project was to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective was accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the fourth year of the five-year project for each of the four areas including a status report of field activities leading up to injection of CO{sub 2}.
Joseph Moore
2011-08-24
The Steamboat Springs geothermal system provides the most dramatic example of subhorizontal thermal-fluid aquifers in crystalline rock in the Basin and Range, but this is by no means an isolated case. Similar but more diffuse subhorizontal permeability has been reported at Roosevelt Hot Springs and Cove-Fort Sulphurdale, Utah; and a km-scale gravity-slide block channels injectate at Dixie Valley, Nevada. During the course of this phase of the project 2543 reports including text, figures and large format enclosures, 1428 maps, and 698 well logs were scanned. The information is stored in a Microsoft Access Database on the Geothermal Server. Detailed geologic cross sections of the Desert Peak geothermal field were developed to identify the structural controls on the geothermal system and locate possible fluid flow paths. The results of this work were published by Lutz and others (2009, Appendix 1) in the Stanford Reservoir Engineering Conference Proceedings.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; et al
2016-03-07
A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13 TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1 TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. As a result, limits aremore » also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions.« less
Knight, Bill; Schechter, David S.
2001-11-19
The goal of this project was to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. The four areas have been completed and reported in the previous annual reports. This report provides the results of the final year of the project including two SPE papers (SPE 71605 and SPE 71635) presented in the 2001 SPE Annual Meeting in New Orleans, two simulation works, analysis of logging observation wells (LOW) and progress of CO{sub 2} injection.
Zempolich, W.G.; Hardie, L.A. )
1991-03-01
The Vajont Limestone is predominantly composed of resedimented oolite that was deposited by gravity-flow processes in a deep-water setting. The present study examines associated micrite ooze and micrite-chip breccias found in upper and lower slope settings. An open seaway gravity-flow model is proposed for Vajont deposition. A peri-platform ooze facies was found to overlie a thick succession of oolitic gravity-flow deposits. This facies is composed of (1) bedded, platform-derived, radiolaride-rich micrite; and (2) channelized, fossil- and clast-rich, oolitic debris flows. Bedded micrite contains burrows and borings that are filled by micrite and/or oolite. These features suggest that bioturbation occurred before and after lithification. Channelized debris flows contain skeletal fragments, oolite, and pebble- to boulder-size clasts of platform lithologies. Micrite-chip breccias are found in lower slope settings and are composed of micrite clasts and oolite. Breccias exhibit both clast- and matrix-supported fabric and are found at the base of fining- and thinning-upward depositional cycles. Micrite clasts contain burrows and borings similar to those found in bedded micrites. These data suggest that breakup and transportation of micrite clasts and oolite, by gravity flow processes, occurred after significant periods of hemipelagic sedimentation in upper slope settings. Peri-platform micrite ooze and micrite-chip breccias exhibit a complex history of sediment deposition, bioturbation, and lithification in upper and lower slope environs. These and other field data suggest that an open seaway gravity-flow model is appropriate for Vajont deposition.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Heavy Oil Heavy oil is a vast U.S. oil resource that is underexploited because its highly viscous nature renders it difficult to produce and to refine. As higher-gravity crudes (lighter oil) become increasingly scarce in the U.S., American operators are looking more and more to low-gravity crudes (heavy oil) to prop up the Nation's declining oil output. Heavy oil generally is defined as having an API (American Petroleum Institute) gravity of 10-20 degrees. Oil sources with even lower gravities,
Garca-Diaz, Alberto A.
2014-01-14
Using the Schwarzschild coordinate frame for a static cyclic symmetric metric in 2+1 gravity coupled minimally to a dilaton logarithmically depending on the radial coordinate in the presence of an exponential potential, by solving first order linear Einstein equations, the general solution is derived and it is identified with the ChanMann dilaton solution. In these coordinates, a new stationary dilaton solution is obtained; it does not allow for a de SitterAnti-de Sitter limit at spatial infinity, where its structural functions increase indefinitely. On the other hand, it is horizonless and allows for a naked singularity at the origin of coordinates; moreover, one can identify at a large radial coordinate a (quasi-local) mass parameter and in the whole space a constant angular momentum. Via a general SL(2,R)transformation, applied on the static cyclic symmetric metric, a family of stationary dilaton solutions has been generated. A particular SL(2,R)transformation is identified, which gives rise to the rotating ChanMann dilaton solution. All the exhibited solutions have been characterized by their quasi-local energy, mass, and momentum through their series expansions at spatial infinity. The algebraic structure of the Riccienergy-momentum, and Cotton tensors is given explicitly.
Thomas G. Hildenbrand; Geoffrey A. Phelps; Edward A. Mankinen
2006-09-21
A three-dimensional inversion of gravity data from the Rainier Mesa area and surrounding regions reveals a topographically complex pre-Cenozoic basement surface. This model of the depth to pre-Cenozoic basement rocks is intended for use in a 3D hydrogeologic model being constructed for the Rainier Mesa area. Prior to this study, our knowledge of the depth to pre-Cenozoic basement rocks was based on a regional model, applicable to general studies of the greater Nevada Test Site area but inappropriate for higher resolution modeling of ground-water flow across the Rainier Mesa area. The new model incorporates several changes that lead to significant improvements over the previous regional view. First, the addition of constraining wells, encountering old volcanic rocks lying above but near pre-Cenozoic basement, prevents modeled basement from being too shallow. Second, an extensive literature and well data search has led to an increased understanding of the change of rock density with depth in the vicinity of Rainier Mesa. The third, and most important change, relates to the application of several depth-density relationships in the study area instead of a single generalized relationship, thereby improving the overall model fit. In general, the pre-Cenozoic basement surface deepens in the western part of the study area, delineating collapses within the Silent Canyon and Timber Mountain caldera complexes, and shallows in the east in the Eleana Range and Yucca Flat regions, where basement crops out. In the Rainier Mesa study area, basement is generally shallow (< 1 km). The new model identifies previously unrecognized structures within the pre-Cenozoic basement that may influence ground-water flow, such as a shallow basement ridge related to an inferred fault extending northward from Rainier Mesa into Kawich Valley.
1996-12-01
Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Lightweight Radioisotope Heater Unit (LWRHU) for Cassini/Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is generally assumed to be recession corresponding to 75% and 100% of the wall thickness. The 75% recession failure criteria allows for uncertainties that result mainly because of the high energies involved in the VVEJGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact with a clad that had been molten. Within the limitations of the methodologies and assumptions of the analyses, the results indicate that: (1) For a side-on stable LWRHU reentry, aeroshell ablation failures occur for all reentry angles. (2)For a side-on spinning LWRHU reentry, aeroshell ablation failures are minimal. (3) For the tumbling LWRHU reentry, the aeroshell survives for most angles. (4) For the thermostructural analyses, using both a 1% and 5% allowable strain, all reentry angles and orientations examined resulted in small localized failures, but aeroshell breach is not predicted for any case. The analyses included in this report concentrate on VVEJGA reentry scenarios. Analyses reported previously have demonstrated that the LWRHU has adequate design margin to survive reentry from orbital decay scenarios and most injection scenarios at speeds up to escape speeds. The exception is a narrow range of flight path angles that produce multiple skip trajectories which may have excessive ablation.
Schechter, D.S.
1996-12-17
The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) analytical and numerical simulation of Spraberry reservoirs, and, (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the first year of the five-year project for each of the four areas.
Smith, L.B.; Durney, T.E. Jr.
1990-07-24
Coal Technology Corporation (CTC) believes that the new CTC high gravity, high production, batch type centrifugal dryer technology can play a significant role in improving the product quality as well as costs of operation in coal processing plants. It is further believed that the new centrifugal dryer technology can form an important part in systems used to clean up the millions of tons of coal fines in refuse piles and ponds. It is anticipated that the new centrifuge can become an important ancillary to the advanced deep cleaning processes for coal. Because of these convictions, CTC has been engaged in a pioneering research effort into the new art of drying fine clean coal in high gravity, high production, batch type centrifuges, since 1981. This work has progressed to the point where the new centrifugal dryer technology is nearly ready for commercialization. It promises to provide needed fine coal drying capability at somewhat lower capital costs and at substantially lower operating costs than competitive systems. It also promises to do so with no detrimental effects on either the coal quality or the evironment. The primary objective of this project is to prove the concept in a commercial coal processing plant environment. The proof of concept tests will also include testing with a variety of coals from different regions. A further objective will be to optimize the efficiency and the cost effectiveness of the new centrifugal dryer technology.
Henry, T.W.; Wardlaw, B.R.
1987-01-01
The Pacific Enewetak Atoll Crater Exploration (PEACE) Program was established to resolve a number of questions for the Department of Defense (DOD) about the geologic and material-properties parameters of two craters (KOA and OAK), formed by near-surface bursts of high-yield thermonuclear devices on the northern margin of Enewetak Atoll, Marshall Islands, in 1958. The multidisciplinary studies conducted by the USGS in collaboration with other organizations during 1984 through 1987 were part of a much larger research initiative by the DNA to better understand the dynamic properties of strategic-scale nuclear bursts and the relevance of the Pacific Proving Grounds (PPG) craters to issues of strategic basing and targeting of nuclear weapons. Major topics include: Borehole gravity; Palentologic evidence for mixing; Electron paramagnetic resonance studies; Bathymetric studies of OAK crater; Constraints on densification and piping for OAK; and Additional studies of geologic crater models.
Process and economic model of in-field heavy oil upgrading using aqueous pyrolysis
Thorsness, C. B., LLNL
1997-01-21
A process and economic model for aqueous pyrolysis in-field upgrading of heavy oil has been developed. The model has been constructed using the ASPEN PLUS chemical process simulator. The process features cracking of heavy oil at moderate temperatures in the presence of water to increase oil quality and thus the value of the oil. Calculations with the model indicate that for a 464 Mg/day (3,000 bbl/day) process, which increases the oil API gravity of the processed oil from 13.5{degree} to 22.4{degree}, the required value increase of the oil would need to be at least $2.80/Mg{center_dot}{degree}API($0.40/bbl{center_dot}{degree}API) to make the process economically attractive. This level of upgrading has been demonstrated in preliminary experiments with candidate catalysts. For improved catalysts capable of having the coke make and increasing the pyrolysis rate, a required price increase for the oil as low as $1.34/Mg{center_dot}{degree}API ($0.21/bbl{center_dot}{degree}API)has been calculated.
Recent Research to Address Technical Barriers to Increased Use...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Biodiesel ASTM Update and Future Technical Needs Biodiesel Research Update Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel
Geology and geochemistry of crude oils, Bolivar coastal fields, Venezuela
Bockmeulen, H.; Barker, C.; Dickey, P.A.
1983-02-01
The Bolivar Coastal Fields (BCF) are located on the eastern margin of Lake Maracaibo, Venezuela. They form the largest oil field outside of the Middle East and contain mostly heavy oil with a gravity less than 22/sup 0/ API. Thirty crude oils from the BCF were collected along two parallel and generally southwest-northeast trends. These oils were characterized by their API gravity, percent saturates, aromatics, NSO and asphalitic compounds, gas chromatograms for whole oils, C/sub 4/-C/sub 7/ fractions, and aromatics. Also, 24 associated waters were sampled and analyzed for Ca/sup + +/, Mg/sup + +/, Na/sup +/, HCO/sub 3//sup -/, CO/sub 3//sup - -/, SO/sub 4//sup - -/, pH, and total dissolved solids (TDS). The geological and geochemical significances of these analyses are discussed with particular emphasis on the genesis of the petroleum.
Stephens, D. C.; Leggett, S. K.; Geballe, T. R.; Cushing, Michael C.; Marley, Mark S.; Saumon, D.; Golimowski, David A.; Noll, K. S.; Fan Xiaohui
2009-09-01
We present new 5.2-14.5 {mu}m low-resolution spectra of 14 mid-L to mid-T dwarfs. We also present new 3.0-4.1 {mu}m spectra for five of these dwarfs. These data are supplemented by existing red and near-infrared spectra ({approx}0.6-2.5 {mu}m), as well as red through mid-infrared spectroscopy of seven other L and T dwarfs presented by Cushing et al. We compare these spectra to those generated from the model atmospheres of Saumon and Marley. The models reproduce the observed spectra well, except in the case of one very red L3.5 dwarf, 2MASS J22244381-0158521. The broad wavelength coverage allows us to constrain almost independently the four parameters used to describe these photospheres in our models: effective temperature (T {sub eff}), surface gravity, grain sedimentation efficiency (f{sub sed}), and vertical gas transport efficiency (K{sub zz} ). The CH{sub 4} bands centered at 2.2, 3.3, and 7.65 {mu}m and the CO band at 2.3 {mu}m are sensitive to K{sub zz} , and indicates that chemical mixing is important in all L and T dwarf atmospheres. The sample of L3.5 to T5.5 dwarfs spans the range 1800 K{approx}> T{sub eff} {approx}>1000 K, with an L-T transition (spectral types L7 to T4) that lies between 1400 and 1100 K for dwarfs with typical near-infrared colors; bluer and redder dwarfs can be 100 K warmer or cooler, respectively, when using infrared spectral types. When using optical spectral types, the bluer dwarfs have more typical T {sub eff} values as they tend to have earlier optical spectral types. In this model analysis, f {sub sed} increases rapidly between types T0 and T4, indicating that increased sedimentation can explain the rapid disappearance of clouds at this stage of brown dwarf evolution. There is a suggestion that the transition to dust-free atmospheres happens at lower temperatures for lower gravity dwarfs.
Press Room - U.S. Energy Information Administration (EIA)
Gasoline and Diesel Fuel Update (EIA)
Press Releases EIA now provides monthly state-level estimates of small-scale solar PV capacity and generation December 1, 2015 EIA expands monthly reporting of crude oil production with new data by API gravity November 30, 2015 U.S. proved oil and natural gas reserves rise in 2014 November 23, 2015 MEDIA ADVISORY: EIA to Release Winter Fuels Outlook September 29, 2015 More press releases... Congressional Testimony Oversight of the renewable fuel standard pdf Subject: EIA, Renewable, Forecasts
Stalheim, Mr. Douglas; Boggess, Todd; San Marchi, Chris; Jansto, Steven; Somerday, Dr. B; Muralidharan, Govindarajan; Sofronis, Prof. Petros
2010-01-01
The continued growth of the world s developing countries has placed an ever increasing demand on traditional fossil fuel energy sources. This development has lead to increasing research and development of alternative energy sources. Hydrogen gas is one of the potential alternative energy sources under development. Currently the most economical method of transporting large quantities of hydrogen gas is through steel pipelines. It is well known that hydrogen embrittlement has the potential to degrade steel s mechanical properties when hydrogen migrates into the steel matrix. Consequently, the current pipeline infrastructure used in hydrogen transport is typically operated in a conservative fashion. This operational practice is not conducive to economical movement of significant volumes of hydrogen gas as an alternative to fossil fuels. The degradation of the mechanical properties of steels in hydrogen service is known to depend on the microstructure of the steel. Understanding the levels of mechanical property degradation of a given microstructure when exposed to hydrogen gas under pressure can be used to evaluate the suitability of the existing pipeline infrastructure for hydrogen service and guide alloy and microstructure design for new hydrogen pipeline infrastructure. To this end, the 2 Copyright 2010 by ASME microstructures of relevant steels and their mechanical properties in relevant gaseous hydrogen environments must be fully characterized to establish suitability for transporting hydrogen. A project to evaluate four commercially available pipeline steels alloy/microstructure performance in the presences of gaseous hydrogen has been funded by the US Department of Energy along with the private sector. The microstructures of four pipeline steels were characterized and then tensile testing was conducted in gaseous hydrogen and helium at pressures of 800, 1600 and 3000 psi. Based on measurements of reduction of area, two of the four steels that performed the best across the pressure range were selected for evaluation of fracture and fatigue performance in gaseous hydrogen at 800 and 3000 psi. This paper will describe the work performed on four commercially available pipeline steels in the presence of gaseous hydrogen at pressures relevant for transport in pipelines. Microstructures and mechanical property performances will be compared. In addition, recommendations for future work related to gaining a better understanding of steel pipeline performance in hydrogen service will be discussed.
Utility Rates API Version 2 is Live! | OpenEI Community
utility Utility Companies utility rate Utility Rates version 1 version 2 version 3 web service Smart meter After several months of development and testing, the next...
API-ANGA-IPAA-AXPC response letter SEAB FracFocus TF
Broader source: Energy.gov (indexed) [DOE]
... 2011, lead to the conclusion that the oil and gas industry has met this challenge in ... the seventeen states are Alabama, California, Colorado, Kansas, Louisiana, ...
Announcing New Utility Rate Database and API Features! | OpenEI...
more to come): Via the System Advisor Model for PV economic value analysis. See http:sam.nrel.gov for more information about downloading the free SAM tool and how utility rates...
How to get TOU information using REST API... | OpenEI Community
relevant. I am looking for different rates for different times of use. I see a nice matrix display of data with numbers (1,2,3 etc) representing different rates, in the Energy...
How to discover the API key needed for table creation in the...
a JSON file to create table ExampleTable in schema snafu get apikey for dhiller2 from cassandra using cqlsh (0x736f6d65756e697175656b6579666f72726567697374726174696f6e) yes, I...
Lorenz APIs and REST Services (Technical Report) | SciTech Connect
Office of Scientific and Technical Information (OSTI)
Research Org: Lawrence Livermore National Laboratory (LLNL), Livermore, CA Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 97 MATHEMATICS, ...
Vehicle Technologies Office Merit Review 2015: Alternative Fuels Data Center and API
Broader source: Energy.gov [DOE]
Presentation given by National Renewable Energy Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about...
Gravity Data for west-central Colorado
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Zehner, Richard
2012-04-06
West -108.366692 East -105.478847 North 40.932361 South 36.961606 Data from From University of Texas: Pan American Center for Earth and Environmental Studies
Dirac matrices for Chern-Simons gravity
Izaurieta, Fernando; Ramirez, Ricardo; Rodriguez, Eduardo
2012-10-06
A genuine gauge theory for the Poincare, de Sitter or anti-de Sitter algebras can be constructed in (2n- 1)-dimensional spacetime by means of the Chern-Simons form, yielding a gravitational theory that differs from General Relativity but shares many of its properties, such as second order field equations for the metric. The particular form of the Lagrangian is determined by a rank n, symmetric tensor invariant under the relevant algebra. In practice, the calculation of this invariant tensor can be reduced to the computation of the trace of the symmetrized product of n Dirac Gamma matrices {Gamma}{sub ab} in 2n-dimensional spacetime. While straightforward in principle, this calculation can become extremely cumbersome in practice. For large enough n, existing computer algebra packages take an inordinate long time to produce the answer or plainly fail having used up all available memory. In this talk we show that the general formula for the trace of the symmetrized product of 2n Gamma matrices {Gamma}{sub ab} can be written as a certain sum over the integer partitions s of n, with every term being multiplied by a numerical cofficient {alpha}{sub s}. We then give a general algorithm that computes the {alpha}-coefficients as the solution of a linear system of equations generated by evaluating the general formula for different sets of tensors B{sup ab} with random numerical entries. A recurrence relation between different coefficients is shown to hold and is used in a second, 'minimal' algorithm to greatly speed up the computations. Runtime of the minimal algorithm stays below 1 min on a typical desktop computer for up to n = 25, which easily covers all foreseeable applications of the trace formula.
High frequency background quantization of gravity
von Borzeszkowski, H.
1982-06-01
Considering background quantization of gravitational fields, it is generally assumed that the classical background satisfies Einstein's gravitational equations. However, there exist arguments showing that, for high frequency (quantum) fluctuations, this assumption has to be replaced by a condition describing the back reaction of fluctuations on the background. It is shown that such an approach leads to limitations for the quantum procedure which occur at distances larger than Planck's elementary length 1 = (Gh/c/sup 3/)/sup 1/2/.
Gravity Data for west-central Colorado
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Zehner, Richard
West -108.366692 East -105.478847 North 40.932361 South 36.961606 Data from From University of Texas: Pan American Center for Earth and Environmental Studies
EQUATORIAL ZONAL JETS AND JUPITER's GRAVITY
Kong, D.; Liao, X.; Zhang, K.; Schubert, G.
2014-08-20
The depth of penetration of Jupiter's zonal winds into the planet's interior is unknown. A possible way to determine the depth is to measure the effects of the winds on the planet's high-order zonal gravitational coefficients, a task to be undertaken by the Juno spacecraft. It is shown here that the equatorial winds alone largely determine these coefficients which are nearly independent of the depth of the non-equatorial winds.
Gasoline and Diesel Fuel Update (EIA)
Crude oil and lease condensate production by API gravity category in selected Lower 48 states and the Federal Gulf of Mexico thousand barrels per day API Year-to-date State/Area Category Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 Volume Share Lower 48 <=20.0 492 481 460 479 466 437 440 442 437 437 441 431 453 5.1% 20.1-25.0 288 312 263 299 257 189 220 197 248 252 231 251 250 2.8% 25.1-30.0 609 575 592 601 574 548 673 737 653 653 689 701 634 7.1%
Recent Research to Address Technical Barriers to Increased Use of Biodiesel
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
| Department of Energy Biodiesel ASTM Update and Future Technical Needs Biodiesel Research Update Biodiesel Progress: ASTM Specifications and 2nd Generation Biodiesel
Assays for important Mexican crudes updated
Manriguez, L.; Moreno, A.; Anaya, C.G. )
1991-03-04
Compared to Isthmus and Maya, Olmeca crude is the lightest of the Mexican export. It has fewer contaminants, and its 540{degrees} C. TBP distillation produces the largest quantity of distillate. The Olmeca fractions also have the lowest total sulfur content. The Maya crude is heavy, with an API gravity of 22.2{sup {degrees}}. It has a high contaminant content that induces corrosion in process equipment and causes low running times in thermal cracking units, such as visbreakers and cokers. A proposed refining scheme for the bottom of the Maya barrel consists of atmospheric distillation, vacuum distillation, the Impex process, and visbreaking.
U.S. Refinery Crude Oil Input Qualities
Gasoline and Diesel Fuel Update (EIA)
Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 View History Sulfur Content, Weighted Average (Percent) 1.39 1.36 1.36 1.37 1.44 1.44 1985-2015 API Gravity, Weighted Average (Degrees) 31.73 31.69 31.44 31.53 31.67 31.31 1985-2015 - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: Totals may not equal sum of components due to independent rounding. See Definitions, Sources, and Notes link above for more information on this
U.S. Refinery Crude Oil Input Qualities
U.S. Energy Information Administration (EIA) Indexed Site
2010 2011 2012 2013 2014 2015 View History Sulfur Content, Weighted Average (Percent) 1.39 1.40 1.42 1.44 1.45 1.40 1985-2015 API Gravity, Weighted Average (Degrees) 30.71 30.69 31.0 30.79 31.77 31.68 1985-2015 - = No Data Reported; -- = Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: Totals may not equal sum of components due to independent rounding. See Definitions, Sources, and Notes link above for more information on this table. Release
Using supercritical fluids to refine hydrocarbons
Yarbro, Stephen Lee
2015-06-09
A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.
Press Room - Press Releases - U.S. Energy Information Administration (EIA)
Gasoline and Diesel Fuel Update (EIA)
Year: 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 Press Releases EIA now provides monthly state-level estimates of small-scale solar PV capacity and generation December 1, 2015 EIA expands monthly reporting of crude oil production with new data by API gravity November 30, 2015 U.S. proved oil and natural gas reserves rise in 2014 November 23, 2015 MEDIA ADVISORY: EIA to Release Winter Fuels Outlook September 29, 2015 Effect of removing crude
Technical Standards Newsletter - April 2007 | Department of Energy
Office of Environmental Management (EM)
2 *American Society of Mechanical Engineers (ASME) ... 2 *ASTM International ... 2 *American Nuclear Society (ANS)...
Non-relativistic Gravity in Entropic Quantum Dynamics
Johnson, David T.; Caticha, Ariel
2011-03-14
Symmetries and transformations are explored in the framework of entropic quantum dynamics. This discussion leads to two conditions that are required for any transformation to qualify as a symmetry. The heart of this work lies in the application of these conditions to the extended Galilean transformation, which admits features of both special and general relativity. The effective gravitational potential representative of the strong equivalence principle arises naturally.
Ground Gravity Survey At Long Valley Caldera Geothermal Area...
Permanent Scatterer (PS) InSAR data to infer strain at depth, (2) working with Lane Johnson to develop a dynamic faulting model, and (3) acquiring InSAR data for the region...
Gravity Duals of Lifshitz-Like Fixed Points (Journal Article...
Office of Scientific and Technical Information (OSTI)
DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article Resource Relation: Journal Name: Phys.Rev.D78:106005,2008 Research Org: Stanford Linear Accelerator Center...
Ground Gravity Survey At Roosevelt Hot Springs Geothermal Area...
model. References S. H. Ward, W. T. Parry, W. P. Nash, W. R. Sill, K. L. Cook, R. B. Smith, D. S. Chapman, F. H. Brown, J. A. Whelan, J. R. Bowman (1978) A Summary of the...
Ground Gravity Survey At North Brawley Geothermal Area (Department...
mentioned in an environmental impact report written for the planning of the first experimental power plant at North Brawley References County of Imperial Planning Department...
Ground Gravity Survey At Waunita Hot Springs Geothermal Area...
to the coarse scale of the conducted survey, it is hard to explicitly identify Tomichi Dome or other local features . References A. L. Lange (1981) The Geophysical Environment...
Spontaneous Lorentz and diffeomorphism violation, massive modes, and gravity
Bluhm, Robert; Fung Shuhong; Kostelecky, V. Alan
2008-03-15
Theories with spontaneous local Lorentz and diffeomorphism violation contain massless Nambu-Goldstone modes, which arise as field excitations in the minimum of the symmetry-breaking potential. If the shape of the potential also allows excitations above the minimum, then an alternative gravitational Higgs mechanism can occur in which massive modes involving the metric appear. The origin and basic properties of the massive modes are addressed in the general context involving an arbitrary tensor vacuum value. Special attention is given to the case of bumblebee models, which are gravitationally coupled vector theories with spontaneous local Lorentz and diffeomorphism violation. Mode expansions are presented in both local and spacetime frames, revealing the Nambu-Goldstone and massive modes via decomposition of the metric and bumblebee fields, and the associated symmetry properties and gauge fixing are discussed. The class of bumblebee models with kinetic terms of the Maxwell form is used as a focus for more detailed study. The nature of the associated conservation laws and the interpretation as a candidate alternative to Einstein-Maxwell theory are investigated. Explicit examples involving smooth and Lagrange-multiplier potentials are studied to illustrate features of the massive modes, including their origin, nature, dispersion laws, and effects on gravitational interactions. In the weak static limit, the massive mode and Lagrange-multiplier fields are found to modify the Newton and Coulomb potentials. The nature and implications of these modifications are examined.
Cosmological singularities in Born-Infeld determinantal gravity...
Office of Scientific and Technical Information (OSTI)
American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text Accepted...
Galileons coupled to massive gravity: general analysis and cosmological solutions
Goon, Garrett; Trodden, Mark; Gmrko?lu, A. Emir; Hinterbichler, Kurt; Mukohyama, Shinji E-mail: Emir.Gumrukcuoglu@nottingham.ac.uk E-mail: shinji.mukohyama@ipmu.jp
2014-08-01
We further develop the framework for coupling galileons and Dirac-Born-Infeld (DBI) scalar fields to a massive graviton while retaining both the non-linear symmetries of the scalars and ghost-freedom of the theory. The general construction is recast in terms of vielbeins which simplifies calculations and allows for compact expressions. Expressions for the general form of the action are derived, with special emphasis on those models which descend from maximally symmetric spaces. We demonstrate the existence of maximally symmetric solutions to the fully non-linear theory and analyze their spectrum of quadratic fluctuations. Finally, we consider self-accelerating cosmological solutions and study their perturbations, showing that the vector and scalar modes have vanishing kinetic terms.
The Origin of Mass and the Feebleness of Gravity
Wilczek, Frank
2010-09-01
BSA Distinguished Lecture presented by Frank Wilczek, co-winner of the 2004 Nobel Prize in Physics. Einstein's famous equation E=mc^2 asserts that energy and mass are different aspects of the same reality. The general public usually associates the equation with the idea that small amounts of mass can be converted into large amounts of energy, as in nuclear reactors and bombs. For physicists who study the basic nature of matter, however, the more important idea is just the opposite.
Ground Gravity Survey At Mokapu Penninsula Area (Thomas, 1986...
it may be assumed that if a thermal resource is associated with the Koolau caldera, its temperature is probably very low. References Donald M. Thomas (1 January 1986) Geothermal...
Ground Gravity Survey At Lightning Dock Area (Cunniff & Bowers...
stations in nine linear traverses that covered more than one hundred (100) square kilometers centered on the known resource area in Section 7 (figure 3). References Roy A....
Ground Gravity Survey At Marysville Mt Area (Blackwell) | Open...
and with the heat flow anomaly. References D. D. Blackwell (Unknown) Exploration In A Blind Geothermal Area Near Marysville, Montana, Usa Additional References Retrieved from...
Ground Gravity Survey At Dixie Valley Geothermal Field Area ...
most useful in identifying the surface projection of subsurface contacts of greatest density contrast, (Blackwell et al., 2002). Thus where the contact is sharp and large the...
Ground Gravity Survey At Lightning Dock Area (Warpinski, Et Al...
into the combined thermal, hydrologic, and subsurface stratigraphic information data sets to provide a comprehensive integrated geothermal model. From all of this...
A Gravity Dual of Metastable Dynamical Supersymmetry Breaking...
Office of Scientific and Technical Information (OSTI)
Subject: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; DUALITY; EXPECTATION VALUE; RENORMALIZATION; SUPERGRAVITY; SUPERSYMMETRY; SYMMETRY BREAKING; SU GROUPS Theory-HEP,HEPTH...
Ground Gravity Survey At Dixie Valley Geothermal Area (Allis...
R. G. Allis, P. Gettings, D. S. Chapman (2000) Precise Gravimetry and Geothermal Reservoir Management Additional References Retrieved from "http:en.openei.orgw...
Application Of Gravity And Deep Dipole Geoelectrics In The Volcanic...
classes, by a trial-and-error adjustment to the relationship between resistivity and density, a 3-D block model of the basement was finally constructed, which consistently...
Ground Gravity Survey At Long Valley Caldera Geothermal Area...
(Battaglia et al., 2003a,b). Data suggest that the shallower source is of intermediate density between magma and aqueous fluid, and so uplift of the resurgent dome may relate to...
Non-minimal Kinetic coupling to gravity and accelerated expansion
Granda, L.N.
2010-07-01
We study a scalar field with kinetic term coupled to itself and to the curvature, as a source of dark energy, and analyze the role of this new coupling in the accelerated expansion at large times. In the case of scalar field dominance, the scalar field and potential giving rise to power-law expansion are found in some cases, and a dynamical equation of state is calculated for a given solution of the field equations. A behavior very close to that of the cosmological constant was found.
General non-minimal kinetic coupling to gravity
Granda, L.N.; Cardona, W. E-mail: wilalbca@univalle.edu.co
2010-07-01
We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, as a source of dark energy, and analyze the cosmological dynamics of this model and the issue of accelerated expansion. Solutions giving rise to power-law expansion have been found. The dynamical equation of state is studied for the two cases, without and with free kinetic term . In the first case, a behavior very close to that of the cosmological constant was found. In the second case, a solution was found, which match the current phenomenology of the dark energy. The model shows a rich variety of dynamical scenarios.
Problems with propagation and time evolution in f ( T ) gravity...
Office of Scientific and Technical Information (OSTI)
D Additional Journal Information: Journal Volume: 88; Journal Issue: 2; Journal ID: ISSN 1550-7998 Publisher: American Physical Society Sponsoring Org: USDOE Country of...