Powered by Deep Web Technologies
Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Category:Atlanta, GA | Open Energy Information  

Open Energy Info (EERE)

GA GA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Atlanta, GA" The following 16 files are in this category, out of 16 total. SVFullServiceRestaurant Atlanta GA Georgia Power Co.png SVFullServiceRestauran... 81 KB SVHospital Atlanta GA Georgia Power Co.png SVHospital Atlanta GA ... 81 KB SVLargeHotel Atlanta GA Georgia Power Co.png SVLargeHotel Atlanta G... 74 KB SVLargeOffice Atlanta GA Georgia Power Co.png SVLargeOffice Atlanta ... 82 KB SVMediumOffice Atlanta GA Georgia Power Co.png SVMediumOffice Atlanta... 84 KB SVMidriseApartment Atlanta GA Georgia Power Co.png SVMidriseApartment Atl... 82 KB SVOutPatient Atlanta GA Georgia Power Co.png SVOutPatient Atlanta G... 83 KB SVPrimarySchool Atlanta GA Georgia Power Co.png SVPrimarySchool Atlant...

2

In: Proceedings of the 1995 International environmental conference; 1995 May 7-10; Atlanta, GA. Atlanta, GA: TAPPI PRESS: 445-448; 1995.  

E-Print Network [OSTI]

. Atlanta, GA: TAPPI PRESS: 445-448; 1995. ENVIRONMENTALLY SOUND ALTERNATIVES FOR UPGRADING MIXED OFFICE

Abubakr, Said

3

FUPWG Meeting Agenda - Atlanta, GA | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Atlanta, GA Atlanta, GA FUPWG Meeting Agenda - Atlanta, GA October 7, 2013 - 3:16pm Addthis Energy on My Mind / FUPWG / Atlanta, GA / May 3-4, 2006 Hosted by: AGL Resources Logo May 3-4, 2006 Hosted by AGL Resources Atlanta, Georgia Tuesday, May 2, 2006 5:00 - 6:30 Steering Committee meeting in the Danube Tigris Room 6:30 until... Networking dinner at the Marriott Wednesday, May 3, 2006 7:45 am Registration/Continental Breakfast 8:30 - 8:45 Welcome from Suzanne Sitherwood, SVP, Southern Operations, President, Atlanta Gas Light, Chattanooga Gas & Florida City Gas 8:45 - 9:00 FEMP Southeast Regional Office Welcome Traci Leath, FEMP 9:00 - 9:45 Washington Update David McAndrew, FEMP 9:45 - 10:15 Break - Networking 10:15 - 11:20 Navy Technical Program Update Paul Kistler, U.S. Navy

4

1ACM SIGCSE'14, Atlanta, GA Using Gamification in Technical  

E-Print Network [OSTI]

1ACM SIGCSE'14, Atlanta, GA Using Gamification in Technical Higher Education: An XP Report. Epema, An Experience Report on Using Gamification in Technical Higher Education, ACM SIGCSE'14. http's not you, it's me · New ambition of GamificationU (Top-20 Eng/Tech*) ·

Iosup, Alexandru

5

E-Print Network 3.0 - atlanta ga usa Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics and Astronomy, Georgia State University, Atlanta, Georgia... 30303, USA 3 NDP Optronics, Mableton, Georgia 30126, USA *Corresponding author: wzshen... -band imaging device,...

6

Source Apportionment of Daily Fine Particulate Matter at Jefferson Street, Atlanta, GA, during Summer and Winter  

E-Print Network [OSTI]

, especially wood burning, as well as vehicular exhaust, and suggest that secondary aerosol for- mation dominates in summer in Atlanta. TECHNICAL PAPER ISSN 1047-3289 J. Air & Waste Manage. Assoc. 57:228­242 Copyright 2007 Air & Waste Management Association 228 Journal of the Air & Waste Management Association

Zheng, Mei

7

NJ WY AK AL CA AR CO CT DE FL GA HI ID KS IL IN IA IA KY LA  

Gasoline and Diesel Fuel Update (EIA)

0.00-1.99 0.00-1.99 2.00-2.99 3.00-3.99 4.00-4.99 5.00-5.99 6.00-6.99 7.00+ NJ WY AK AL CA AR CO CT DE FL GA HI ID KS IL IN IA IA KY LA ME MI MA MD MN MS MT MO NE ND OH NV NM NY NH NC OK OR PA RI SC SD TN TX UT VT WA WV WI AZ VA DC 0.00-1.99 2.00-2.99 3.00-3.99 4.00-4.99 5.00-5.99 6.00-6.99 7.00+ 18. Average Price of Natural Gas Delivered to U.S. Onsystem Industrial Consumers, 1996 (Dollars per Thousand Cubic Feet) Figure 19. Average Price of Natural Gas Delivered to U.S. Electric Utilities, 1996 (Dollars per Thousand Cubic Feet) Figure Sources: Federal Energy Regulatory Commission (FERC), Form FERC-423, "Monthly Report of Cost and Quality of Fuels for Electric Plants," and Energy Information Administration (EIA), Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition." Note: In 1996, consumption of natural gas for agricultural use

8

Atlanta Survey  

U.S. Energy Information Administration (EIA) Indexed Site

Profile of Motor-Vehicle Fleets in Atlanta 1994 Profile of Motor-Vehicle Fleets in Atlanta 1994 Assessing the Market for Alternative-Fuel Vehicles 13 Data Tables for Private Fleets There are two types of tables. One type provides counts of the number of fleets that fall into various categories of data. The other provides counts of the number of vehicles by characteristics. Where only fleet data are provided instead of vehicle data, it means that particular questionnaire item was asked at the fleet level only. Vehicle questions were recorded by type of vehicle not by individual vehicle. Table 1. Number of Private Fleets in Atlanta by Fleet Size and Selected Characteristics Fleet Size (number of vehicles) Selected Characteristics Total 6 to 19 20 to 49 50 or More Total Number of Fleets . . . . . . . . . . . . . . . 3,589

9

2009 National Electric Transmission Congestion Study - Atlanta Workshop |  

Broader source: Energy.gov (indexed) [DOE]

2009 National Electric Transmission Congestion Study - Atlanta 2009 National Electric Transmission Congestion Study - Atlanta Workshop 2009 National Electric Transmission Congestion Study - Atlanta Workshop On July 29, 2008, DOE hosted a regional pre-study workshop in Atlanta, GA to receive input and suggestions concerning the 2009 National Electric Transmission Congestion Study. The agenda and full transcript are available below. 7-29-08 Congestion Workshop Agenda - Atlanta, GA.pdf Transcript - 2009 National Electric Transmission Congestion Study Atlanta Workshop.pdf More Documents & Publications 2009 National Electric Transmission Congestion Study - San Francisco Workshop 2012 National Electric Transmission Congestion Study - St. Louis Workshop 2009 National Electric Transmission Congestion Study - Las Vegas Workshop

10

EECBG Success Story: Atlanta Suburb Greases the Path to Savings...  

Energy Savers [EERE]

Atlanta Suburb Greases the Path to Savings with Biodiesel The new energy efficient IT Data Center in Savannah, Georgia. | Courtesy of the City of Savannah, GA. EECBG Success...

11

Atlanta, Georgia: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Atlanta, Georgia: Energy Resources Atlanta, Georgia: Energy Resources (Redirected from Atlanta, GA) Jump to: navigation, search Equivalent URI DBpedia Coordinates 33.7489954°, -84.3879824° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.7489954,"lon":-84.3879824,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

12

TEC Rail TG Summary_Atlanta  

Broader source: Energy.gov (indexed) [DOE]

March 5-6, 2007 Atlanta, GA March 5-6, 2007 Atlanta, GA Rail Topic Group Alex Thrower began the meeting and welcomed all topic group participants and support contractor staff. Mr. Thrower established that the following issues and sub-topic group matters required further consideration and in some cases next steps needed to be planned. These include: Inspections Checklist Mr. Thrower requested that members submit their feedback on the items inspected during point of origin and en route inspections in the form of a short listing. Next steps involve: * Presenting the checklist to Federal Railroad Administration (FRA) state managers in a preliminary format; * Discussions with DOT in regard to formatting the checklist; and * Development of a complete reference list to be placed onto blue cards to be used

13

Table 2 -Lime use and practices on Corn, major producing states, 2001 CO GA IL IN IA KS KY MI MN MO NE NY NC ND OH PA SD TX WI Area  

E-Print Network [OSTI]

Table 2 - Lime use and practices on Corn, major producing states, 2001 CO GA IL IN IA KS KY MI MN.7 Table 2 - Lime use and practices on Corn, major producing states, 2000 CO IL IN IA KS KY MI MN MO NE NY use and practices on Corn, major producing states, 1999 CO IL IN IA KS KY MI MN MO NE NC OH SD TX WI

Kammen, Daniel M.

14

Atlanta- Sustainable Development Design Standards  

Broader source: Energy.gov [DOE]

In December 2003, the City of Atlanta passed a green building [http://www.atlantaga.gov/modules/showdocument.aspx?documentid=547 ordinance] that applies to city-owned facilities and city-funded...

15

Atlanta TEC Meeting -- Tribal Group Summary 3-6-07  

Broader source: Energy.gov (indexed) [DOE]

Atlanta, GA - January 31, 2007 Atlanta, GA - January 31, 2007 Session Chaired by: Jay Jones (DOE, Office of Civilian Radioactive Waste Management, OCRWM) Regular Members in Attendance: Kenny Anderson (Las Vegas Paiute Tribe), Richard Arnold (Las Vegas Indian Center/Pahrump Paiute Tribe), Tony Boyd (Pueblo of Acoma), Rob Burnside (Confederated Tribes of the Umatilla Indian Reservation, CTUIR), Floyd Chaney (Mohegan Tribe), Sandra Covi (Union Pacific Railroad), Martha Crosland (DOE/Office of General Counsel, GC), Kristen Ellis (DOE/Intergovernmental and External Affairs, CI), Frank Gavigan (Mohegan Tribe), Ed Gonzales (ELG Engineering/Pueblo de San Ildefonso), Robert Gruenig (National Tribal Environmental Council, NTEC), Paloma Hill (OCRWM Intern), Judith Holm (OCRWM), Gayl Honanie (Hopi Tribe), Lisa Janairo

16

City of Atlanta Video (Text Version)  

Broader source: Energy.gov [DOE]

Aaron Bastian: According to the U.S. EPA, Atlanta is one of the top ten cities in the country for green buildings. It is a city that is walk and bike friendly, and now Atlanta is second in the...

17

Microsoft PowerPoint - 6-03 DOE EM TEM Atlanta AREVA CCIM final 111010.ppt  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

November 17, 2010 November 17, 2010 Next-Generation Induction Melter Technology Development DOE EM Waste Processing Technical Exchange, Nov 16-18, 2010, Atlanta, GA Eric Tchemitcheff, AFS Print Close > DOE EM Waste Processing Technical Exchange - Nov 16-18, 2010 - Atlanta, GA 3 Presentation Outline Introduction CCIM Key Attributes CCIM Target Performance for Hanford WTP Applications EM Tank Waste R&D Plan Initiative 5.2.1  Scope and Objectives - CCIM Project CCIM Project - Proposed HLW Tasks and Milestones CCIM Project - Proposed LAW Tasks and Milestones CCIM Project - Summary FY10 Accomplishments CCIM Project - Anticipated Near-term Outcomes CCIM Project - Summary - Focus Areas Print Close > DOE EM Waste Processing Technical Exchange - Nov 16-18, 2010 - Atlanta, GA 4 DOE EM radwaste vitrification processing challenges are

18

Atlanta Chemical Engineering LLC | Open Energy Information  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Atlanta Chemical Engineering LLC Jump to: navigation, search Logo: Atlanta Chemical Engineering LLC Name Atlanta Chemical Engineering LLC Place Marietta, Georgia Zip 30064 Country United States Sector Biomass Year founded 2008 Company Type For Profit Company Ownership Private Small Business Yes References Atlanta Chemical Engineering LLC[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Atlanta Chemical Engineering LLC is a company based in Marietta, Georgia. References ↑ "Atlanta Chemical Engineering LLC" Retrieved from "http://en.openei.org/w/index.php?title=Atlanta_Chemical_Engineering_LLC&oldid=699086"

19

Better Buildings Challenge, Atlanta Nears Halfway Mark in Meeting...  

Broader source: Energy.gov (indexed) [DOE]

Challenge Breakout Session Panel with representatives from the City of Atlanta Office of Sustainability, Southface, the U.S. General Services Administration, and two Atlanta BBC...

20

Federal Utility Partnership Working Group: Atlanta Gas Light...  

Broader source: Energy.gov (indexed) [DOE]

Group: Atlanta Gas Light Resources Federal Utility Partnership Working Group: Atlanta Gas Light Resources Presentation-given at the April 2012 Federal Utility Partnership Working...

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG  

Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

Atlanta Airport Atlanta Airport Converts Shuttles to CNG to someone by E-mail Share Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Facebook Tweet about Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Twitter Bookmark Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Google Bookmark Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Delicious Rank Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on Digg Find More places to share Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG on AddThis.com... Sept. 9, 2012 Atlanta Airport Converts Shuttles to CNG L earn how an Atlanta company saves money and conserves fuel with compressed natural gas airport shuttles.

22

Microsoft Word - Transcript_Pre-2009 Congestion Study_Atlanta.doc  

Broader source: Energy.gov (indexed) [DOE]

7/29/2008 7/29/2008 Atlanta, GA Page 1 U.S. Department of Energy Pre-Congestion Study Regional Workshops for the 2009 National Electric Congestion Study Atlanta, GA July 29, 2008 9:00 a.m.-12:30 p.m. Transcript David Meyer: Ladies and gentlemen, I'm David Meyer from the Department of Energy. I want to welcome you to our workshop for upcoming 2009 congestion studies. I'm going to make a short presentation here scoping out what we have in mind and what our purposes are in holding this workshop. But, before I do that, I want to introduce some of my colleagues here, particularly Lot Cooke who is from our General Counsel's office. Several other people from my office at the Department of Energy: Mark Whitenton and Elliott Nethercutt; and Elizabeth

23

Workplace Charging Challenge Partner: City of Atlanta | Department...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Partner City of Atlanta. View more videos on the Alternative Fuels and Advanced Vehicles Data Center. Skyline view of the City of Atlanta at sunset. Text version Meet Challenge...

24

E-Print Network 3.0 - atlanta georgia metropolitan Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: University; Atlanta, Georgia September 1996 - Assistant Professor of Political Science Emory University... ; Atlanta, Georgia September 1993 - August 1996 On...

25

IA Blog Archive  

Broader source: Energy.gov (indexed) [DOE]

71 IA Blog Archive en IA News Archive http:energy.goviaia-news-archive IA News Archive

26

Atlanta Community Leaders' Institute Conference | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Atlanta Community Leaders' Institute Conference Atlanta Community Leaders' Institute Conference Atlanta Community Leaders' Institute Conference April 15, 2013 - 1:31pm Addthis Dr. David Satcher speaks at the Community Leaders' Institute at Morehouse School of Medicine in Atlanta, Georgia. Dr. David Satcher speaks at the Community Leaders' Institute at Morehouse School of Medicine in Atlanta, Georgia. What does this project do? Goal 1. Protect human health and the environment The Atlanta Community Leaders Institute (CLI) held a conference on February 8 and 9 at Morehouse School of Medicine, in Atlanta, Georgia. The conference was sponsored by the Medical University of South Carolina, U.S. Department of Energy, Southeastern Virtual Institute for Health and Wellness, U.S. Department of Defense, DeKalb County, Morehouse School of

27

Atlanta Community Leaders' Institute Conference | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Atlanta Community Leaders' Institute Conference Atlanta Community Leaders' Institute Conference Atlanta Community Leaders' Institute Conference April 15, 2013 - 1:31pm Addthis Dr. David Satcher speaks at the Community Leaders' Institute at Morehouse School of Medicine in Atlanta, Georgia. Dr. David Satcher speaks at the Community Leaders' Institute at Morehouse School of Medicine in Atlanta, Georgia. What does this project do? Goal 1. Protect human health and the environment The Atlanta Community Leaders Institute (CLI) held a conference on February 8 and 9 at Morehouse School of Medicine, in Atlanta, Georgia. The conference was sponsored by the Medical University of South Carolina, U.S. Department of Energy, Southeastern Virtual Institute for Health and Wellness, U.S. Department of Defense, DeKalb County, Morehouse School of

28

Building America Technology Solutions for New and Existing Homes: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia (Fact Sheet),  

Broader source: Energy.gov [DOE]

This case study describes the construction of a new test home in Atlanta, GA, that demonstrates current best practices for the mixed-humid climate, including a building envelope featuring advanced air sealing details and low density spray foam insulation, glazing that exceeds ENERGY STAR requirements, and a high performance heating and cooling system.

29

Making Connections for Atlanta Students | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Making Connections for Atlanta Students Making Connections for Atlanta Students Making Connections for Atlanta Students June 4, 2013 - 4:29pm Addthis Mary Shoemaker A rising senior at Georgia Tech Editor's note: In the last week in April, Director Dot Harris of the U.S. Department of Energy's Office of Economic Impact and Diversity gathered alongside local energy leaders at Clark Atlanta University for the Atlanta Students in Energy and Climate Forum. Mary Shoemaker, a rising senior at Georgia Tech, was one of the student speakers at the event. The following is her perspective of the event. On a beautiful afternoon in April, I found myself surrounded by like-minded individuals: students, entrepreneurs, and professors gathered to share experiences and motivations in their pursuit of environmental stewardship.

30

E-Print Network 3.0 - atlanta urban rain Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(2008). Shem and Shepherd (2009) noted that Atlanta creates enhanced convergence at the rural-urban... delineation of urban convection for Atlanta, Georgia. Int. J. Climatol., 30,...

31

Microsoft Word - Atlanta Agenda FINAL _2_.doc  

Broader source: Energy.gov (indexed) [DOE]

Westin Peachtree Plaza Hotel Westin Peachtree Plaza Hotel Atlanta, Georgia July 29, 2008 AGENDA 8:00 - 9:00 am Registration 9:00 - 9:15 am DOE Presentation Plans for the 2009 Congestion Study and Objectives of Workshop 9:15 - 10:30 am Panel I Panelists: Cindy Miller, Senior Attorney, Office of General Counsel, Florida Public Service Commission The Honorable Jim Sullivan, President, Alabama Public Service Commission Charles Terreni, Executive Director, South Carolina Public Service Commission Burl D. Till, III, Manager, Transmission Planning Department, Tennessee Valley Authority The Honorable Stan Wise, Commissioner, Georgia Public Service Commission 10:30 -10:45 am Break 10:45 - 12:00 pm Panel II Panelists: George Bartlett, Director, Transmission Planning and Operations, Entergy Services

32

Terahertz absorption in AlGaAs films and detection using heterojunctions  

E-Print Network [OSTI]

a Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA b NDP Optronics, LLC-mail address: uperera@gsu.edu (A.G.U. Perera). 1 Also at NDP Optronics LLC. Infrared Physics & Technology 47

Perera, A. G. Unil

33

Atlanta NAVIGATOR case study. Final report, May 1996--Jun 1997  

SciTech Connect (OSTI)

The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation Systems (ITS) deployments in the United States. This deployment included several individual projects--a Central Transportation Management Center (TMC), six Traffic Control Centers (TCC), one Transit Information Center (TIC), the Travel Information Showcase (TIS), and the extension of the Metropolitan Atlanta Rapid Transit Authority (MARTA) rail network and the new high-occupancy vehicle (HOV) lanes on I-85 and I-75. The Atlanta Centennial Olympic Games and Paralympic Games created a focus for these projects. All of these systems were to be brought on line in time for the Olympic Games. This report presents the findings of the NAVIGATOR Case Study and documents the lessons learned from the Atlanta ITS deployment experience in order to improve other ITS deployments in the future. The Case Study focuses on the institutional, programmatic, and technical issues and opportunities from planning and implementing the ITS deployment in Atlanta. The Case Study collected data and information from interviews, observations, focus groups, and documentation reviews. It presents a series of lessons learned and recommendations for enabling successful ITS deployments nationwide.

Amodei, R.; Bard, E.; Brong, B.; Cahoon, F.; Jasper, K.

1998-11-01T23:59:59.000Z

34

Microsoft Word - Final TEC Notes Atlanta 07.doc  

Broader source: Energy.gov (indexed) [DOE]

TRANSPORTATION EXTERNAL COORDINATION WORKING GROUP MEETING January 31-February 1, 2007 Atlanta, Georgia Welcome and Meeting Overview The U.S. Department of Energy (DOE), Transportation External Coordination Working Group (TEC) held its 27th meeting on January 31-February 1, 2007, in Atlanta, Georgia. One hundred thirteen participants, representing national, State, Tribal, and local government; industry; professional organizations; and other interested parties, met to address a variety of issues related to DOE's radioactive materials transportation activities. The TEC process includes the involvement of these key stakeholders in developing solutions to DOE transportation issues through their actual participation in the work product. These members

35

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY ATLANTA FEDERAL CENTER  

E-Print Network [OSTI]

Number 2001-10096 Subject: COE Regulatory Final Environmental Impact Statement (FEIS) for "PCS Phosphate) regulatory Final Environmental Impact Statement (FEIS). This FEIS evaluates the environmental consequencesUNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4 ATLANTA FEDERAL CENTER 61 FORSYTH STREET

Demers, Nora Egan

36

North Atlanta, Georgia: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

North Atlanta, Georgia: Energy Resources North Atlanta, Georgia: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 33.8651033°, -84.3365917° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.8651033,"lon":-84.3365917,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

37

Category:Mason, IA | Open Energy Information  

Open Energy Info (EERE)

IA IA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Mason, IA" The following 16 files are in this category, out of 16 total. SVQuickServiceRestaurant Mason IA MidAmerican Energy Co (Iowa).png SVQuickServiceRestaura... 64 KB SVFullServiceRestaurant Mason IA MidAmerican Energy Co (Iowa).png SVFullServiceRestauran... 64 KB SVHospital Mason IA MidAmerican Energy Co (Iowa).png SVHospital Mason IA Mi... 73 KB SVLargeHotel Mason IA MidAmerican Energy Co (Iowa).png SVLargeHotel Mason IA ... 72 KB SVLargeOffice Mason IA MidAmerican Energy Co (Iowa).png SVLargeOffice Mason IA... 73 KB SVMediumOffice Mason IA MidAmerican Energy Co (Iowa).png SVMediumOffice Mason I... 69 KB SVMidriseApartment Mason IA MidAmerican Energy Co (Iowa).png

38

Better Buildings Challenge, Atlanta Nears Halfway Mark in Meeting Citywide Goal of 20% Energy Savings  

Broader source: Energy.gov [DOE]

The Energy Department yesterday recognized Atlanta for its progress and leadership in meeting a citywide goal to improve the energy performance of its buildings by 20% by 2020.

39

New approaches for modeling type Ia supernovae  

E-Print Network [OSTI]

ich and J. Stein. On the thermonuclear runaway in Type IaSmall-Scale Stability of Thermonuclear Flames o in Type IaS. E. Woosley. The thermonuclear explosion of chandrasekhar

Zingale, Michael; Almgren, Ann S.; Bell, John B.; Day, Marcus S.; Rendleman, Charles A.; Woosley, Stan

2007-01-01T23:59:59.000Z

40

Statement by Energy Secretary Steven Chu on Opening of Atlanta Job Training  

Broader source: Energy.gov (indexed) [DOE]

Opening of Atlanta Job Opening of Atlanta Job Training Center Statement by Energy Secretary Steven Chu on Opening of Atlanta Job Training Center October 26, 2010 - 12:00am Addthis WASHINGTON, D.C. - U.S. Energy Secretary Steven Chu issued the following statement on today's grand opening of the Southeast Weatherization & Energy Efficiency Training (SWEET) Center in Atlanta, Georgia. "The SWEET Center in Atlanta will play a critical role in training thousands of workers for new jobs, laying the foundation for continued growth in this developing industry. With help from the Recovery Act, this program will provide workers with the skills they need to offer local homeowners quality energy efficiency upgrades that will save them money by saving energy." BACKGROUND INFORMATION ON TODAY'S ANNOUNCEMENT

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Abstract IA37: Clinical genomics  

Science Journals Connector (OSTI)

...Research. 15 October 2014 meeting-abstract Clinical Genomics Clinical Genomics: Oral Presentations - Invited Abstracts Abstracts...2013; San Diego, CA Abstract IA37: Clinical genomics Katherine A. Janeway Dana-Farber Cancer Institute...

Katherine A. Janeway

2014-10-15T23:59:59.000Z

42

Building America Case Study: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia (Fact Sheet)  

SciTech Connect (OSTI)

As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA in the mixed-humid climate. This home serves as a residence and home office for the firm's owners, as well as a demonstration of their design approach to potential and current clients. Southface believes the home demonstrates current best practices for the mixed-humid climate, including a building envelope featuring advanced air sealing details and low density spray foam insulation, glazing that exceeds ENERGY STAR requirements, and a high performance heating and cooling system. Construction quality and execution was a high priority for TaC Studios and was ensured by a third party review process. Post construction testing showed that the project met stated goals for envelope performance, an air infiltration rate of 2.15 ACH50. The homeowner's wished to further validate whole house energy savings through the project's involvement with Building America and this long-term monitoring effort. As a Building America test home, this home was evaluated to detail whole house energy use, end use loads, and the efficiency and operation of the ground source heat pump and associated systems. Given that the home includes many non-typical end use loads including a home office, pool, landscape water feature, and other luxury features not accounted for in Building America modeling tools, these end uses were separately monitored to determine their impact on overall energy consumption.

Not Available

2014-09-01T23:59:59.000Z

43

Community transportation : alternative transportation provision in a low-income neighborhoods in southeast Atlanta  

E-Print Network [OSTI]

Regional transit agencies are ineffective at meeting many of the basic transportation needs of a clustered "Study Area" of low-income Atlanta neighborhoods. For transit dependant residents in the Study Area, getting to the ...

Alexander, James W., 1977-

2004-01-01T23:59:59.000Z

44

E-Print Network 3.0 - atlanta georgia usa Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

georgia usa Search Powered by Explorit Topic List Advanced Search Sample search results for: atlanta georgia usa Page: << < 1 2 3 4 5 > >> 1 (virulence) CAI-1 System Summary: OF...

45

RECIPIENT:Gwinnett Co, GA  

Broader source: Energy.gov (indexed) [DOE]

Gwinnett Co, GA Gwinnett Co, GA u.s DEPARUIENT OFENllRGY EERE PROJECT MANAGEMENT CENTER NllPA DETERl\JINATION PROJECr TITLE: Gwinnett Co, GA EEC8G Page I or2 STATE: GA Funding Opportunity Announcement Number Procu~ment Instrument Number N[PA Control Number CID Number DE-EEOOOOS05.005 0 Based on my review ortbe information concerning tbe proposed action, as NEPA Compliance Officer (authorized under DOE Order 4SI.IA), I bave made the following determination: ex, EA, EIS APPENDIX AND NUMBER: Description: 8 5.1 Actions to conserve energy, demonstrate potential energy conservation, and promote energy-efficiency that do not increase the indoor concentrations of potentially harmful substances. These actions may involve financial and technical assistance to individuals (such as builders, owners, consultants, designers), organizations (such as utilities), and state

46

String Landscape and Supernovae Ia  

E-Print Network [OSTI]

We present a model for the triggering of Supernovae Ia (SN Ia) by a phase transition to exact supersymmetry (susy) in the core of a white dwarf star. The model, which accomodates the data on SN Ia and avoids the problems of the standard astrophysical accretion based picture, is based on string landscape ideas and assumes that the decay of the false broken susy vacuum is enhanced at high density. In a slowly expanding susy bubble, the conversion of pairs of fermions to pairs of degenerate scalars releases a significant amount of energy which induces fusion in the surrounding normal matter shell. After cooling, the absence of degeneracy pressure causes the susy bubble to collapse to a black hole of about 0.1 solar mass or to some other stable susy object.

L. Clavelli

2011-10-09T23:59:59.000Z

47

No evidence for acid-catalyzed secondary organic aerosol formation in power plant plumes over metropolitan Atlanta, Georgia - article no. L06801  

SciTech Connect (OSTI)

Aircraft-based measurements of the water-soluble fraction of fine PM organic carbon (WSOC) and inorganic salt composition in the Atlanta, GA region were conducted in the summer of 2004. Five notable plumes of SO{sub 2}, apparently from coal-fired power plants, were intercepted, and had NH{sub 4}{sup +}/SO4{sup 2-} molar ratios ranging from approximately 0.8 to 1.4 compared to molar ratios near 2 outside of the plumes. Sulfate aerosol concentrations increased from a regional background of 5 - 8 {mu} g m{sup -3} to as high as 19.5 {mu} g m{sup -3} within these plumes. No increase in WSOC concentrations was observed in plumes compared to out-of-plumes within a WSOC measurement uncertainty of 8%. These measurements suggest that secondary organic aerosol formation via heterogeneous acid-catalyzed reactions within power plant plumes are not likely a significant contributor to the ambient aerosol mass loading in Atlanta and the surrounding region. Because this region is rich in both biogenic and anthropogenic volatile organic carbon (VOC), the results may be widely applicable.

Peltier, R.E.; Sullivan, A.P.; Weber, R.J.; Wollny, A.G.; Holloway, J.S.; Brock, C.A.; de Gouw, J.A.; Atlas, E.L. [Georgia Institute for Technology, Atlanta, GA (United States). School for Earth and Atmospheric Science

2007-03-15T23:59:59.000Z

48

Atlanta Suburb Greases the Path to Savings with Biodiesel | Department of  

Broader source: Energy.gov (indexed) [DOE]

Atlanta Suburb Greases the Path to Savings with Biodiesel Atlanta Suburb Greases the Path to Savings with Biodiesel Atlanta Suburb Greases the Path to Savings with Biodiesel December 7, 2011 - 3:33pm Addthis Downtown Smyrna, Georgia, a town that's poised to see big savings thanks to their investment in biodiesel. | Photo by Ken Cook Downtown Smyrna, Georgia, a town that's poised to see big savings thanks to their investment in biodiesel. | Photo by Ken Cook Chris Galm Marketing & Communications Specialist, Office of Energy Efficiency & Renewable Energy What does this project do? Reduces fuel consumption Saves the city money Extends the lifespan of city owned service vehicles "We sat down and actually met with several people out of the biodiesel industry and found out how amazingly simple it was for us to do this. To

49

Atlanta Suburb Greases the Path to Savings with Biodiesel | Department of  

Broader source: Energy.gov (indexed) [DOE]

Atlanta Suburb Greases the Path to Savings with Biodiesel Atlanta Suburb Greases the Path to Savings with Biodiesel Atlanta Suburb Greases the Path to Savings with Biodiesel December 7, 2011 - 3:33pm Addthis Downtown Smyrna, Georgia, a town that's poised to see big savings thanks to their investment in biodiesel. | Photo by Ken Cook Downtown Smyrna, Georgia, a town that's poised to see big savings thanks to their investment in biodiesel. | Photo by Ken Cook Chris Galm Marketing & Communications Specialist, Office of Energy Efficiency & Renewable Energy What does this project do? Reduces fuel consumption Saves the city money Extends the lifespan of city owned service vehicles "We sat down and actually met with several people out of the biodiesel industry and found out how amazingly simple it was for us to do this. To

50

Microsoft PowerPoint - Clark Atlanta DOE MEI Small Business presentation August 2009 for pdf.ppt [Compatibility Mode]  

Broader source: Energy.gov (indexed) [DOE]

CLARK ATLANTA UNIVERSITY CLARK ATLANTA UNIVERSITY CLARK ATLANTA UNIVERSITY Presentation at the Presentation at the CLARK ATLANTA UNIVERSITY CLARK ATLANTA UNIVERSITY Presentation at the Presentation at the 10 10 th th Annual DOE MEI Small Business Conference Annual DOE MEI Small Business Conference CAU's Energy Related Research Capabilities CAU's Energy Related Research Capabilities 10 10 th th Annual DOE MEI Small Business Conference Annual DOE MEI Small Business Conference CAU's Energy Related Research Capabilities CAU's Energy Related Research Capabilities Ishrat M Khan Ph.D. Ishrat M Khan Ph.D. Ishrat M Khan Ph.D. Ishrat M Khan Ph.D. Director, Center for Functional Director, Center for Functional Nanoscale Nanoscale Materials Materials ikhan@cau.edu ikhan@cau.edu www cau edu/research www

51

Black and White Commuting Behavior in a Large Southern City: Evidence from Atlanta  

E-Print Network [OSTI]

Black and White Commuting Behavior in a Large Southern City: Evidence from Atlanta Clark, W. A. VV430X. William A. V. Clark Youqin Huang Black and White Commuting Behavior in a Large Southern City and white households are consistent with the overall hypothesis that households min- imize their commuting

Huang, Youqin

52

Analyzing the Performance of a Multiobjective GA-P Algorithm for Learning Fuzzy Queries in  

E-Print Network [OSTI]

Analyzing the Performance of a Multiobjective GA-P Algorithm for Learning Fuzzy Queries in a Machine Learning Environment Oscar Cord´on1 , Enrique Herrera-Viedma1 , Mar´ia Luque1 , F´elix de Moya2- tionary algorithms (EAs) [1], such as genetic algorithm-programming (GA-P) [11] or simulated annealing

Fernandez, Thomas

53

Synthesis and properties of green phosphor SrGa2S4:Eu2 emission displays by an environmentally clean technique  

E-Print Network [OSTI]

by an environmentally clean technique Y.D. Jianga , G. Villalobosa , J.C. Souriaua , H. Parisa , C.J. Summersa , Z.L. Wangb,* a Phosphor Technology Center of Excellence, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA b School of Materials Science and Engineering, Georgia

Wang, Zhong L.

54

Steamboat IA Geothermal Facility | Open Energy Information  

Open Energy Info (EERE)

IA Geothermal Facility IA Geothermal Facility Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Steamboat IA Geothermal Facility General Information Name Steamboat IA Geothermal Facility Facility Steamboat IA Sector Geothermal energy Location Information Location Washoe, Nevada Coordinates 40.5608387°, -119.6035495° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.5608387,"lon":-119.6035495,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

55

Summary of Needs and Opportunities from the 2011 Residential Energy Efficiency Stakeholders Meeting: Atlanta, Georgia-- March 16-18, 2011  

Broader source: Energy.gov [DOE]

This summary report outlines needs and issues for increasing energy efficiency of new and existing U.S homes, as identified at the U.S Department of Energy Building America program Spring 2011 stakeholder meeting in Atlanta, Georgia.

56

A Dynamic GISMulticriteria Technique for Siting the NASAClark Atlanta Urban Rain Gauge Network  

Science Journals Connector (OSTI)

Because Atlanta, Georgia, is a model of rapid transition from forest/agriculture land use to urbanization, NASA and other agencies have initiated programs to identify and understand how urban heat islands (UHIs) impact the environment in terms of ...

J. Marshall Shepherd; Olayiwola O. Taylor; Carlos Garza

2004-09-01T23:59:59.000Z

57

THE LOCAL HOSTS OF TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

We use multi-wavelength, matched aperture, integrated photometry from the Galaxy Evolution Explorer (GALEX), the Sloan Digital Sky Survey, and the RC3 to estimate the physical properties of 166 nearby galaxies hosting 168 well-observed Type Ia supernovae (SNe Ia). The ultraviolet (UV) imaging of local SN Ia hosts from GALEX allows a direct comparison with higher-redshift hosts measured at optical wavelengths that correspond to the rest-frame UV. Our data corroborate well-known features that have been seen in other SN Ia samples. Specifically, hosts with active star formation produce brighter and slower SNe Ia on average, and hosts with luminosity-weighted ages older than 1 Gyr produce on average more faint, fast, and fewer bright, slow SNe Ia than younger hosts. New results include that in our sample, the faintest and fastest SNe Ia occur only in galaxies exceeding a stellar mass threshold of approx10{sup 10} M{sub sun}, leading us to conclude that their progenitors must arise in populations that are older and/or more metal rich than the general SN Ia population. A low host extinction subsample hints at a residual trend in peak luminosity with host age, after correcting for light-curve shape, giving the appearance that older hosts produce less-extincted SNe Ia on average. This has implications for cosmological fitting of SNe Ia, and suggests that host age could be useful as a parameter in the fitting. Converting host mass to metallicity and computing {sup 56}Ni mass from the supernova light curves, we find that our local sample is consistent with a model that predicts a shallow trend between stellar metallicity and the {sup 56}Ni mass that powers the explosion, but we cannot rule out the absence of a trend. We measure a correlation between {sup 56}Ni mass and host age in the local universe that is shallower and not as significant as that seen at higher redshifts. The details of the age-{sup 56}Ni mass correlations at low and higher redshift imply a luminosity-weighted age threshold of approx3 Gyr for SN Ia hosts, above which they are less likely to produce SNe Ia with {sup 56}Ni masses above approx0.5 M{sub sun}.

Neill, James D.; Martin, D. Christopher; Barlow, Tom A.; Foster, Karl; Friedman, Peter G.; Morrissey, Patrick; Wyder, Ted K. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Sullivan, Mark [University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Dr., Suite 102, Goleta, CA 93117 (United States); Conley, Alex [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ONM5S3H8 (Canada); Seibert, Mark; Madore, Barry F. [The Observatories of the Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA, 91101 (United States); Neff, Susan G. [Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Schiminovich, David [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Bianchi, Luciana [Center for Astrophysical Sciences, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Donas, Jose; Milliard, Bruno [Laboratoire d'Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12 (France); Heckman, Timothy M. [Department of Physics and Astronomy, Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Lee, Young-Wook [Center for Space Astrophysics, Yonsei University, Seoul 120-749 (Korea, Republic of); Rich, R. Michael [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

2009-12-20T23:59:59.000Z

58

STATEMENT OF CONSIDERATIONS REQUEST BY ATLANTA GAS LIGHT AND ADSORBENT RESEARCH  

Broader source: Energy.gov (indexed) [DOE]

AUub. -5'94(THU) 14:09 DO PLD-CHICAGO TEL:1 70 252 2779 P, 004 AUub. -5'94(THU) 14:09 DO PLD-CHICAGO TEL:1 70 252 2779 P, 004 STATEMENT OF CONSIDERATIONS REQUEST BY ATLANTA GAS LIGHT AND ADSORBENT RESEARCH GROUP (AGLARG) FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN PATENT RIGHTS UNDER SUBCONTRACT NO. 466590 AT BROOKHAVEN NATIONAL LABORATORY; W(A) -9421, CH-0839 The Atlanta Gac Light and Adsorbent Rcscarch Group (AGLARG), a large business coneortium, hao petitioned for an advance waiver of patent rights under its Subcontract No. 466590 from Brookhaven National Laboratory, operated by Associated Univeraitico, Inc. under DOE Contract No. DE-AC02-76CH00016. The purpooc of this subcontract includes the design, fabrication, testing and demonstration of a fuel storage and fuel delivery system for at least two natural gas powered engines in light duty vehicles

59

Atlanta Centennial Olympic Games and Paralympic Games event study, 1996. Final report, July 1996--August 1996  

SciTech Connect (OSTI)

The Atlanta metropolitan region was the location of one of the most ambitious Intelligent Transportation Systems (ITS) deployments in the United States. This deployment included several individual projects--a Central Transportation Management Center (TMC), six Traffic Control Centers (TCCs), one Transit Information Center (TIC), The Travel Information Showcase (TIS), and the extension of the Metropolitan Atlanta Rapid Transit Authority (MARTA) Rail network and the new high-occupancy vehicle (HOV) lanes on I-85 and I-75. The 1996 Atlanta Centennial Olympic Games and Paralympic Games created a focus for these projects. All of these systems were to be brought on-line in time for the Olympic Games. This report presents the findings of the 1996 Olympic and Paralympic Games Events Study--a compilation of findings of system performance, the benefits realized, and the lessons learned during their operations over the event period. The study assessed the performance of the various Travel Demand Management (TDM) plans employed for Olympic Games traffic management.

Amodei, R.; Bard, E.; Brong, B.; Cahoon, F.; Jasper, K.

1998-11-01T23:59:59.000Z

60

Supersoft Sources as SN Ia Progenitors  

E-Print Network [OSTI]

of the existence of supersoft X­ray sources. It is argued that SNe Ia are thermonuclear explosions of accreting C is that they represent thermonuclear disruptions of mass accreting white dwarfs (WDs). Thus, the basic ingredient

Greiner, Jochen

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

ETODOS NUM ERICOS EN INGENIER IA  

E-Print Network [OSTI]

CONSERVATIVOS ENERG #19; IA-MOMENTO Jos#19;e M. Goicolea Ruig#19;omez y Juan Carlos Garc#19;#16;a Orden EscuelaM #19; ETODOS NUM #19; ERICOS EN INGENIER #19; IA R. Abascal, J. Dom#19;#16;nguez y G. Bugeda (Eds.upm.es Palabras clave: Din#19;amica no lineal, mecanismos, sistemas multicuerpo exibles, energ#19;#16;a- momento

Romero, Ignacio

62

Capacitance hysteresis in GaN/AlGaN heterostructures L. E. Byrum,1  

E-Print Network [OSTI]

Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA 2 NDP Optronics

Matsik, Steven G.

63

GaN/AlGaN heterojunction infrared detector responding in 814 and 2070 m ranges  

E-Print Network [OSTI]

, Georgia State University, Atlanta, Georgia 30303 S. G. Matsik NDP Optronics LLC, Mableton, Georgia 30126 A

Perera, A. G. Unil

64

Rolling Hills (IA) | Open Energy Information  

Open Energy Info (EERE)

Rolling Hills (IA) Rolling Hills (IA) Jump to: navigation, search Name Rolling Hills (IA) Facility Rolling Hills (IA) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner MidAmerican Energy Company Developer MidAmerican Energy Company Energy Purchaser MidAmerican Energy Company Location Massena IA Coordinates 41.230443°, -94.75459° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.230443,"lon":-94.75459,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

65

Presented at the ASHRAE Winter Meeting, Atlanta, GA, February 1721, 1996, and to be published in the Proceedings  

E-Print Network [OSTI]

, and to be published in the Proceedings A Comparison Between Calculated and Measured SHGC for Complex Fenestration Calculated and Measured SHGC for Complex Fenestration Systems J. H. Klems, J. L. Warner, and G. O. Kelley;A Comparison Between Calculated and Measured SHGC for Complex Fenestration Systems J. H. Klems, J. L

66

Thermal comfort in naturally-ventilated and air-conditioned classrooms in the tropics.  

E-Print Network [OSTI]

in kindergartens. IAQ '91 Healthy Buildings, Atlanta, GA,kindergartens. in IAQ '91 Healthy Buildings. 1991. Atlanta,in kindergartens. IAQ '91 Healthy Buildings, Atlanta, GA,

Kwok, Alison G

1997-01-01T23:59:59.000Z

67

A threat-based definition of IA and IA-enabled products.  

SciTech Connect (OSTI)

This paper proposes a definition of 'IA and IA-enabled products' based on threat, as opposed to 'security services' (i.e., 'confidentiality, authentication, integrity, access control or non-repudiation of data'), as provided by Department of Defense (DoD) Instruction 8500.2, 'Information Assurance (IA) Implementation.' The DoDI 8500.2 definition is too broad, making it difficult to distinguish products that need higher protection from those that do not. As a consequence the products that need higher protection do not receive it, increasing risk. The threat-based definition proposed in this paper solves those problems by focusing attention on threats, thereby moving beyond compliance to risk management. (DoDI 8500.2 provides the definitions and controls that form the basis for IA across the DoD.) Familiarity with 8500.2 is assumed.

Shakamuri, Mayuri; Schaefer, Mark A.; Campbell, Philip LaRoche

2010-09-01T23:59:59.000Z

68

A threat-based definition of IA- and IA-enabled products.  

SciTech Connect (OSTI)

This paper proposes a definition of 'IA and IA-enabled products' based on threat, as opposed to 'security services' (i.e., 'confidentiality, authentication, integrity, access control or non-repudiation of data'), as provided by Department of Defense (DoD) Instruction 8500.2, 'Information Assurance (IA) Implementation.' The DoDI 8500.2 definition is too broad, making it difficult to distinguish products that need higher protection from those that do not. As a consequence the products that need higher protection do not receive it, increasing risk. The threat-based definition proposed in this paper solves those problems by focusing attention on threats, thereby moving beyond compliance to risk management. (DoDI 8500.2 provides the definitions and controls that form the basis for IA across the DoD.) Familiarity with 8500.2 is assumed.

Shakamuri, Mayuri; Schaefer, Mark A.; Campbell, Philip LaRoche

2010-07-01T23:59:59.000Z

69

Comparison of Recent SnIa datasets  

E-Print Network [OSTI]

We rank the six latest Type Ia supernova (SnIa) datasets (Constitution (C), Union (U), ESSENCE (Davis) (E), Gold06 (G), SNLS 1yr (S) and SDSS-II (D)) in the context of the Chevalier-Polarski-Linder (CPL) parametrization $w(a)=w_0+w_1 (1-a)$, according to their Figure of Merit (FoM), their consistency with the cosmological constant ($\\Lambda$CDM), their consistency with standard rulers (Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO)) and their mutual consistency. We find a significant improvement of the FoM (defined as the inverse area of the 95.4% parameter contour) with the number of SnIa of these datasets ((C) highest FoM, (U), (G), (D), (E), (S) lowest FoM). Standard rulers (CMB+BAO) have a better FoM by about a factor of 3, compared to the highest FoM SnIa dataset (C). We also find that the ranking sequence based on consistency with $\\Lambda$CDM is identical with the corresponding ranking based on consistency with standard rulers ((S) most consistent, (D), (C), (E), (U), (G) least consistent). The ranking sequence of the datasets however changes when we consider the consistency with an expansion history corresponding to evolving dark energy $(w_0,w_1)=(-1.4,2)$ crossing the phantom divide line $w=-1$ (it is practically reversed to (G), (U), (E), (S), (D), (C)). The SALT2 and MLCS2k2 fitters are also compared and some peculiar features of the SDSS-II dataset when standardized with the MLCS2k2 fitter are pointed out. Finally, we construct a statistic to estimate the internal consistency of a collection of SnIa datasets. We find that even though there is good consistency among most samples taken from the above datasets, this consistency decreases significantly when the Gold06 (G) dataset is included in the sample.

J. C. Bueno Sanchez; S. Nesseris; L. Perivolaropoulos

2009-10-01T23:59:59.000Z

70

COOPERATIVE AND NON-COOPERATIVE DECISION BEHAVIORS IN RESPONSE TO THE INSPECTION AND MAINTENANCE PROGRAM IN THE ATLANTA  

E-Print Network [OSTI]

COOPERATIVE AND NON-COOPERATIVE DECISION BEHAVIORS IN RESPONSE TO THE INSPECTION AND MAINTENANCE BEHAVIORS IN RESPONSE TO THE INSPECTION AND MAINTENANCE PROGRAM IN THE ATLANTA AIRSHED, 1997-2001 Bryan G not have been able to cover the immense research landscape that is presented in this dissertation. Bryan

Vermont, University of

71

Elsevier, Journal of Transport Geography, volume 24, 2012 Atlanta: A Mega Logistics Center in the Piedmont Atlantic Megaregion (PAM)  

E-Print Network [OSTI]

1 Elsevier, Journal of Transport Geography, volume 24, 2012 Atlanta: A Mega Logistics Center.ross@coa.gatech.edu Abstract This paper looks at spatial patterns of freight and logistics activities and the planning and policy issues associated with them. Two important characteristics of the geography of the logistics

Paris-Sud XI, Université de

72

Microsoft PowerPoint - 9-05 Lutze LUTZE - Atlanta Nov 2010.ppt  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

DuraLith Geopolymer Low DuraLith Geopolymer Low Temperature Waste Forms Werner Lutze, Weiliang Gong, and Ian L. Pegg Vitreous State Laboratory The Catholic University of America Washington, DC EM Waste Processing Technical Exchange Atlanta , , Nov. 16 - 18, 2010 Print Close 2 DuraLith Geopolymer Low Temperature Waste Forms A Geopolymer is .... .... an inorganic solid formed by poly-condensation: NaOH n{-O-Si-OH + HO-Al-O-}  {-O-Si-O-Al-O-} n + nH 2 O General formula: (Na,K) n [(SiO 2 ) z -AlO 2 ] n ·wH 2 O 'w' << 1 1≤ z ≤ 3 Print Close 3 DuraLith Geopolymer Low Temperature Waste Forms Geopolymers ....  ... can be made at room temperature from any reactive aluminosilicate with alkali hydroxide or alkali polysilicates  ... contain very little water after complete hardening  ... are resistant to acids

73

NJ WY AK AL CA AR CO CT DE FL GA HI ID KS IL IN IA IA KY LA  

Gasoline and Diesel Fuel Update (EIA)

accomplishments accomplishments are impressive in themselves, and associ- ated with each milestone is the expansion of future produc- tion opportunities as another technical barrier is overcome. The extension of recovery opportunities into deep water has established the deep offshore as an area of considerable national significance. A second source of increased supply is gas from coalbed formations. Natural gas production from coalbed methane fields continued to grow in 1996 as projects initiated mainly in the early to mid 1990's matured through the dewatering phase into higher rates of gas production. Coalbed forma- tions contribute almost 1 trillion cubic feet, roughly 5 per- cent, to total U.S. production. Continued production growth from coalbeds is not likely in light of the precipitous drop in new wells completed in coalbed formations since the termination of the production tax

74

Category:Des Moines, IA | Open Energy Information  

Open Energy Info (EERE)

IA IA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Des Moines, IA" The following 16 files are in this category, out of 16 total. SVFullServiceRestaurant Des Moines IA MidAmerican Energy Co (Iowa).png SVFullServiceRestauran... 64 KB SVQuickServiceRestaurant Des Moines IA MidAmerican Energy Co (Iowa).png SVQuickServiceRestaura... 64 KB SVHospital Des Moines IA MidAmerican Energy Co (Iowa).png SVHospital Des Moines ... 73 KB SVLargeHotel Des Moines IA MidAmerican Energy Co (Iowa).png SVLargeHotel Des Moine... 72 KB SVLargeOffice Des Moines IA MidAmerican Energy Co (Iowa).png SVLargeOffice Des Moin... 73 KB SVMediumOffice Des Moines IA MidAmerican Energy Co (Iowa).png SVMediumOffice Des Moi... 69 KB SVMidriseApartment Des Moines IA MidAmerican Energy Co (Iowa).png

75

DOE - Office of Legacy Management -- Bendix Aviation Corp Pioneer Div - IA  

Office of Legacy Management (LM)

Bendix Aviation Corp Pioneer Div - Bendix Aviation Corp Pioneer Div - IA 05 FUSRAP Considered Sites Site: BENDIX AVIATION CORP., PIONEER DIV. (IA.05 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Pioneer Division, Bendix Aviation Corporation Bendix Aviation Corporation Bendix Pioneer Division IA.05-1 IA.05-2 IA.05-3 Location: Davenport , Iowa IA.05-1 Evaluation Year: 1990 IA.05-2 IA.05-4 Site Operations: Conducted studies to investigate the feasibility of using sonic cleaning equipment to decontaminate uranium contaminated drums. IA.05-1 Site Disposition: Eliminated - Potential for contamination considered remote based on limited operations at the site IA.05-2 IA.05-4 IA.05-5 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium IA.05-1

76

DOE - Office of Legacy Management -- Titus Metals - IA 04  

Office of Legacy Management (LM)

from consideration under FUSRAP Also see Documents Related to TITUS METALS IA.04-1 - Argonne National Laboratory Memorandum; Lonergan to Novak; Subject: Extrusion of Billets,...

77

Conformal cosmological model and SNe Ia data  

SciTech Connect (OSTI)

Now there is a huge scientific activity in astrophysical studies and cosmological ones in particular. Cosmology transforms from a pure theoretical branch of science into an observational one. All the cosmological models have to pass observational tests. The supernovae type Ia (SNe Ia) test is among the most important ones. If one applies the test to determine parameters of the standard Friedmann-Robertson-Walker cosmological model one can conclude that observations lead to the discovery of the dominance of the {Lambda} term and as a result to an acceleration of the Universe. However, there are big mysteries connected with an origin and an essence of dark matter (DM) and the {Lambda} term or dark energy (DE). Alternative theories of gravitation are treated as a possible solution of DM and DE puzzles. The conformal cosmological approach is one of possible alternatives to the standard {Lambda}CDM model. As it was noted several years ago, in the framework of the conformal cosmological approach an introduction of a rigid matter can explain observational data without {Lambda} term (or dark energy). We confirm the claim with much larger set of observational data.

Zakharov, A. F., E-mail: zakharov@itep.ru [National Astronomical Observatories of Chinese Academy of Sciences (China); Pervushin, V. N. [Joint Institute for Nuclear Research, Bogoliubov Laboratory for Theoretical Physics (Russian Federation)

2012-11-15T23:59:59.000Z

78

Type Ia Supernova Explosion: Gravitationally Confined Detonation  

Science Journals Connector (OSTI)

We present a new mechanism for Type Ia supernova explosions in massive white dwarfs. The scenario follows from relaxing assumptions of symmetry and involves a detonation born near the stellar surface. The explosion begins with an essentially central ignition of a deflagration that results in the formation of a buoyancy-driven bubble of hot material that reaches the stellar surface at supersonic speeds. The bubble breakout laterally accelerates fuel-rich outer stellar layers. This material, confined by gravity to the white dwarf, races along the stellar surface and is focused at the location opposite to the point of the bubble breakout. These streams of nuclear fuel carry enough mass and energy to trigger a detonation just above the stellar surface that will incinerate the white dwarf and result in an energetic explosion. The stellar expansion following the deflagration redistributes mass in a way that ensures production of intermediate-mass and iron group elements with ejecta having a strongly layered structure and a mild amount of asymmetry following from the early deflagration phase. This asymmetry, combined with the amount of stellar expansion determined by details of the evolution (principally the energetics of deflagration, timing of detonation, and structure of the progenitor), can be expected to create a family of mildly diverse Type Ia supernova explosions.

T. Plewa; A. C. Calder; D. Q. Lamb

2004-01-01T23:59:59.000Z

79

The distant type Ia supernova rate  

SciTech Connect (OSTI)

We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample,which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R.S.; Aldering, G.; Astier, P.; Deustua, S.E.; Fruchter, A.S.; Goldhaber, G.; Goobar, A.; Groom, D.E.; Hardin, D.; Hook, I.M.; Howell, D.A.; Irwin, M.J.; Kim, A.G.; Kim, M.Y.; Knop, R.A.; Lee, J.C.; Perlmutter, S.; Ruiz-Lapuente, P.; Schahmaneche, K.; Schaefer, B.; Walton, N.A.

2002-05-20T23:59:59.000Z

80

The Distant Type Ia Supernova Rate  

DOE R&D Accomplishments [OSTI]

We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample, which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.

Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R. S.; Aldering, G.; Astier, P.; Deustua, S. E.; Fruchter, A. S.; Goldhaber, G.; Goobar, A.; Groom, D. E.; Hardin, D.; Hook, I. M.; Howell, D. A.; Irwin, M. J.; Kim, A. G.; Kim, M. Y.; Knop, R. A.; Lee, J. C.; Perlmutter, S.; Ruiz-Lapuente, P.; Schahmaneche, K.; Schaefer, B.; Walton, N. A.

2002-05-28T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Intermediate-band Photometry of Type Ia Supernovae  

E-Print Network [OSTI]

We present optical light curves of five Type Ia supernovae (2002er, 2002fk, 2003cg, 2003du, 2003fk). The photometric observations were performed in a set of intermediate-band filters. SNe 2002er, 2003du appear to be normal SN Ia events with similar light curve shapes, while SN 2003kf shows the behavior of a brighter SN Ia with slower decline rate after maximum. The light curves of SN 2003cg is unusual; they show a fast rise and dramatic decline near maximum and do not display secondary peak at longer wavelengths during 15-30 days after maximum light. This suggests that SN 2003cg is likely to be an intrinsically subluminous, 91bg-like SN Ia. Exploration of SN Ia feature lines through intermediate-band photometry is briefly discussed.

Wang, X; Zhang, T; Li, Z; Wang, Xiaofeng; Zhou, Xu; Zhang, Tianmeng; Li, Zongwei

2004-01-01T23:59:59.000Z

82

Visualizing Type Ia Supernova Explosions at NERSC  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Supernova Explosions Supernova Explosions Visualizing Type Ia Supernova Explosions Childs1a-Supernovasm.png Deep inside a dying star in a galaxy far, far away, a carbon fusion flame ignites. Ignition may happen in the middle or displaced slightly to one side, but this simulation explores the consequences of central ignition. In a localized hot spot, represented here by a deformed sphere with an average radius of 100 km, carbon is assumed to have already fused to iron, producing hot ash (~10 billion K) with a density about 20% less than its surroundings. As the burning progresses, this hot buoyant ash rises up and interacts with cold fuel. Rayleigh-Taylor fingers give rise to shear and turbulence, which interacts with the flame, causing it to move faster. In about 2 seconds, the energy released blows the entire white dwarf star up,

83

Performance improvements of ultraviolet/infrared dual-band detectors A.G.U. Perera a,*, G. Ariyawansa a  

E-Print Network [OSTI]

University, Atlanta, GA 30303, United States b NDP Optronics, Mableton, GA 30126, United States c School

Dietz, Nikolaus

84

DOE - Office of Legacy Management -- Iowa Army Ammunition Plant - IA 02  

Office of Legacy Management (LM)

Army Ammunition Plant - IA 02 Army Ammunition Plant - IA 02 FUSRAP Considered Sites Iowa Army Ammunition Plant, IA Alternate Name(s): Burlington Ordnance Plant Iowa Ordnance Plant Silas Mason Company IA.02-3 Location: Located in Township 70 North, Range 3 West, Section 32, 5th Principal Meridian, Des Moines County, Burlington, Iowa IA.02-1 IA.02-5 Historical Operations: Assembled nuclear weapons, primarily high explosive components and conducted explosives testing using the high explosive components and depleted uranium. AEC and ERDA operations conducted under permit from the Department of the Army. IA.02-3 IA.02-4 Eligibility Determination: Eligible IA.02-5 Radiological Survey(s): Assessment Survey IA.02-2 Site Status: Cleanup pending by U.S. Army Corps of Engineers. IA.02-6

85

Summary of Needs and Opportunities from the 2011 Residential Energy Efficiency Stakeholders Meeting: Atlanta, Georgia -- March 16-18, 2011  

Broader source: Energy.gov (indexed) [DOE]

Needs and Needs and Opportunities from the 2011 Residential Energy Efficiency Stakeholders Meeting Atlanta, Georgia - March 16-18, 2011 May 2011 ii NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or

86

Al fraction induced effects on the capacitance characteristics -GaN/AlxGa1-xN IR detectors  

E-Print Network [OSTI]

, Georgia State University, Atlanta, Georgia 30303, USA; bNDP Optronics LLC, Mableton, Georgia 30126, USA; c

Dietz, Nikolaus

87

UMore Ph IA CR Report 7-8-10.pdf  

Broader source: Energy.gov (indexed) [DOE]

PHASE IA ARCHAEOLOGICAL AND PHASE IA ARCHAEOLOGICAL AND ARCHITECTURAL HISTORY SURVEY FOR THE UMORE PARK RESEARCH WIND TURBINE PROJECT, DAKOTA COUNTY, MINNESOTA SHPO File No. Pending Client No. Pending The 106 Group Project No. 10-18 Submitted to: Barr Engineering Company 4700 West 77th Street Minneapolis, MN 55435-4803 Submitted by: The 106 Group Ltd. The Dacotah Building 370 Selby Avenue St. Paul, MN 55102 Principal Investigators: AnneKetz, M.A., RPA Greg Mathis, M.C.R.P. Report Authors: Mark Doperalski, B.S. Miranda Van Vleet, M.H.P July 2010 UMore Park Wind Turbine Project Phase IA Archaeological and Architectural History Survey Page i MANAGEMENT SUMMARY During May of 2010, The 106 Group Ltd. (106 Group) conducted a Phase IA archaeological and architectural history survey for the University of Minnesota Outreach, Research, and

88

CIRCUMSTELLAR ABSORPTION IN DOUBLE DETONATION TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

Upon formation, degenerate He core white dwarfs are surrounded by a radiative H-rich layer primarily supported by ideal gas pressure. In this Letter, we examine the effect of this H-rich layer on mass transfer in He+C/O double white dwarf binaries that will eventually merge and possibly yield a Type Ia supernova (SN Ia) in the double detonation scenario. Because its thermal profile and equation of state differ from the underlying He core, the H-rich layer is transferred stably onto the C/O white dwarf prior to the He core's tidal disruption. We find that this material is ejected from the binary system and sweeps up the surrounding interstellar medium hundreds to thousands of years before the SN Ia. The close match between the resulting circumstellar medium profiles and values inferred from recent observations of circumstellar absorption in SNe Ia gives further credence to the resurgent double detonation scenario.

Shen, Ken J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Guillochon, James [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Foley, Ryan J., E-mail: kenshen@astro.berkeley.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-06-20T23:59:59.000Z

89

Abstract IA14: Functional genomics and cancer vulnerabilities  

Science Journals Connector (OSTI)

...Cancer Research. November 2014 meeting-abstract Genomics Genomics: Oral Presentations - Invited Abstracts Abstracts...2013; San Diego, CA Abstract IA14: Functional genomics and cancer vulnerabilities William C. Hahn Dana-Farber...

William C. Hahn

2014-11-01T23:59:59.000Z

90

EARLY EMISSION FROM TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

A unique feature of deflagration-to-detonation (DDT) white dwarf explosion models of supernovae of type Ia is the presence of a strong shock wave propagating through the outer envelope. We consider the early emission expected in such models, which is produced by the expanding shock-heated outer part of the ejecta and precedes the emission driven by radioactive decay. We expand on earlier analyses by considering the modification of the pre-detonation density profile by the weak shocks generated during the deflagration phase, the time evolution of the opacity, and the deviation of the post-shock equation of state from that obtained for radiation pressure domination. A simple analytic model is presented and shown to provide an acceptable approximation to the results of one-dimensional numerical DDT simulations. Our analysis predicts a {approx}10{sup 3} s long UV/optical flash with a luminosity of {approx}1 to {approx}3 Multiplication-Sign 10{sup 39} erg s{sup -1}. Lower luminosity corresponds to faster (turbulent) deflagration velocity. The luminosity of the UV flash is predicted to be strongly suppressed at t > t{sub drop} {approx} 1 hr due to the deviation from pure radiation domination.

Rabinak, Itay; Waxman, Eli [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Livne, Eli, E-mail: itay.rabinak@weizmann.ac.il [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

2012-09-20T23:59:59.000Z

91

The 1.05-?m feature in the spectrum of the Type Ia supernova 1994D: He in SNe Ia?  

Science Journals Connector (OSTI)

......SNe Ia). Although the agreed basic scenario is thermonuclear fusion within a white dwarf (WD), the process leading...a pressure wave into the WD which then triggers thermonuclear fusion in the core. In this scenario, explosion can......

P. A. Mazzali; L. B. Lucy

1998-04-01T23:59:59.000Z

92

Simulations of Turbulent Thermonuclear Burning in Type Ia Supernovae  

E-Print Network [OSTI]

Type Ia supernovae have recently received considerable attention because it appears that they can be used as "standard candles" to measure cosmic distances out to billions of light years away from us. Observations of type Ia supernovae seem to indicate that we are living in a universe that started to accelerate its expansion when it was about half its present age. These conclusions rest primarily on phenomenological models which, however, lack proper theoretical understanding, mainly because the explosion process, initiated by thermonuclear fusion of carbon and oxygen into heavier elements, is difficult to simulate even on supercomputers. Here, we investigate a new way of modeling turbulent thermonuclear deflagration fronts in white dwarfs undergoing a type Ia supernova explosion. Our approach is based on a level set method which treats the front as a mathematical discontinuity and allows for full coupling between the front geometry and the flow field. New results of the method applied to the problem of type Ia supernovae are obtained. It is shown that in 2-D with high spatial resolution and a physically motivated subgrid scale model for the nuclear flames numerically "converged" results can be obtained, but for most initial conditions the stars do not explode. In contrast, simulations in 3-D, do give the desired explosions and many of their properties, such as the explosion energies, lightcurves and nucleosynthesis products, are in very good agreement with observed type Ia supernovae.

W. Hillebrandt; M. Reinecke; W. Schmidt; F. K. Roepke; C. Travaglio; J. C. Niemeyer

2004-05-11T23:59:59.000Z

93

Urban airshed modeling of air quality impacts of alternative transportation fuel use in Los Angeles and Atlanta  

SciTech Connect (OSTI)

The main objective of NREL in supporting this study is to determine the relative air quality impact of the use of compressed natural gas (CNG) as an alternative transportation fuel when compared to low Reid vapor pressure (RVP) gasoline and reformulated gasoline (RFG). A table lists the criteria, air toxic, and greenhouse gas pollutants for which emissions were estimated for the alternative fuel scenarios. Air quality impacts were then estimated by performing photochemical modeling of the alternative fuel scenarios using the Urban Airshed Model Version 6.21 and the Carbon Bond Mechanism Version IV (CBM-IV) (Geary et al., 1988) Using this model, the authors examined the formation and transport of ozone under alternative fuel strategies for motor vehicle transportation sources for the year 2007. Photochemical modeling was performed for modeling domains in Los Angeles, California, and Atlanta, Georgia.

NONE

1997-12-01T23:59:59.000Z

94

Type Ia Supernovae Yielding Distances with 3-4% Precision  

E-Print Network [OSTI]

The luminosities of Type Ia supernovae (SN), the thermonuclear explosions of white dwarf stars, vary systematically with their intrinsic color and light-curve decline rate. These relationships have been used to calibrate their luminosities to within ~0.14-0.20 mag from broadband optical light curves, yielding individual distances accurate to ~7-10%. Here we identify a subset of SN Ia that erupt in environments having high ultraviolet surface brightness and star-formation surface density. When we apply a steep model extinction law, these SN can be calibrated to within ~0.065-0.075 mag, corresponding to ~3-4% in distance -- the best yet with SN Ia by a substantial margin. The small scatter suggests that variations in only one or two progenitor properties account for their light-curve-width/color/luminosity relation.

Kelly, Patrick L; Burke, David L; Hicken, Malcolm; Ganeshalingam, Mohan; Zheng, Weikang

2014-01-01T23:59:59.000Z

95

Signatures of A Companion Star in Type Ia Supernovae  

E-Print Network [OSTI]

While type Ia Supernovae (SNe Ia) have been used as precise cosmological distance indicators, their progenitor systems remain unresolved. One of the key questions is if there is a non-degenerate companion star at the time of a thermonuclear explosion of a white dwarf (WD). In this paper, we investigate if an interaction between the SN ejecta and the companion star may result in observable footprints around the maximum brightness and thereafter, by performing multi-dimensional radiation transfer simulations based on hydrodynamic simulations of the interaction. We find that such systems result in variations in various observational characteristics due to different viewing directions, while the predicted behaviors (redder and fainter for the companion direction) are opposite to what were suggested by the previous study. The variations are generally modest and within observed scatters. However, the model predicts trends between some observables different from observationally derived, thus a large sample of SNe Ia...

Maeda, Keiichi; Shigeyama, Toshikazu

2014-01-01T23:59:59.000Z

96

Double degenerates and progenitors of supernovae type Ia  

E-Print Network [OSTI]

We report on systematic radial velocity surveys for white dwarf - white dwarf binaries (double degenerates - DDs) including SPY (ESO Supernovae Ia progenitor survey) recently carried out at the VLT. A large sample of DD will allow us to put strong constrains on the phases of close binary evolution of the progenitor systems and to perform an observational test of the DD scenario for supernovae of type Ia. We explain how parameters of the binaries can be derived from various methods. Results for a sample of DDs are presented and discussed.

R. Napiwotzki; L. Yungelson; G. Nelemans; T. R. Marsh; B. Leibundgut; A. Renzini; D. Homaier; D. Koester; S. Moehler; N. Christlieb; D. Reimers; H. Drechsel; U. Heber; C. Karl; E. -M. Pauli

2004-03-25T23:59:59.000Z

97

Search for double degenerate progenitors of supernovae type Ia with SPY  

E-Print Network [OSTI]

We report on a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY).

R. Napiwotzki; H. Drechsel; U. Heber; C. Karl; E. -M. Pauli; N. Christlieb; H. -J. Hagen; D. Reimers; D. Koester; S. Moehler; D. Homeier; B. Leibundgut; A. Renzini; T. R. Marsh; G. Nelemans; L. Yungelson

2002-10-07T23:59:59.000Z

98

Spectral Observations and Analyses of Low-Redshift Type Ia Supernovae  

E-Print Network [OSTI]

1.3.2 Thermonuclear Supernovae . . . . . . . . 1.4 Why WriteIa are the result of thermonuclear explosions of C/O whiteIa are the result of thermonuclear explosions of C/O white

Silverman, Jeffrey Michael

2011-01-01T23:59:59.000Z

99

INDECOMPOSABLE RACKS OF ORDER p 2 MAT IAS GRA  

E-Print Network [OSTI]

INDECOMPOSABLE RACKS OF ORDER p 2 MAT ?? IAS GRA ? NA Abstract. We classify indecomposable racks order is trivial. 1. Introduction Racks and quandles have been considered by G. Wraith and J. Conway categories, one is immediately led to the notion of a rack. On the other hand, in [ESS, EGS, S] and [LYZ1

Graña, Matías

100

INCOMPLETE CARBON-OXYGEN DETONATION IN TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

Incomplete carbon-oxygen detonation with reactions terminating after burning of C{sup 12} in the leading C{sup 12} + C{sup 12} reaction (C-detonation) may occur in the low-density outer layers of white dwarfs exploding as Type Ia supernovae (SNe Ia). Previous studies of carbon-oxygen detonation structure and stability at low densities were performed under the assumption that the velocity of a detonation wave is derived from complete burning of carbon and oxygen to iron. In fact, at densities {rho} {<=} 10{sup 6} g cm{sup -3} the detonation in SNe Ia may release less than a half of the available nuclear energy. In this paper, we study basic properties of such detonations. We find that the length of an unsupported steady-state C-detonation is {approx_equal}30-100 times greater than previously estimated and that the decreased energy has a drastic effect on the detonation stability. In contrast to complete detonations which are one-dimensionally stable, C-detonations may be one-dimensionally unstable and propagate by periodically re-igniting themselves via spontaneous burning. The re-ignition period at {rho} {<=} 10{sup 6} g cm{sup -3} is estimated to be greater than the timescale of an SN Ia explosion. This suggests that propagation and quenching of C-detonations at these densities could be affected by the instability. Potential observational implications of this effect are discussed.

Dominguez, Inma [Departamento de Fisica Teorica y del Cosmos, University of Granada, 18071 Granada (Spain); Khokhlov, Alexei [Department of Astronomy and Astrophysics and the Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States)

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

The EqIA Publishing Template Impact Assessment Summary  

E-Print Network [OSTI]

The EqIA Publishing Template Impact Assessment Summary 1. Name of policy, function or service. Bedgebury 5 year strategy and development plan. This is a partial assessment. 2. Purpose and aims with ETWF: Sustainable Resource, Climate Change, Natural Environment, Quality of Life, Business and Markets

102

HOSPITALITY AND TOURISM MANAGEMENT MAJOR Virgu1iaTech  

E-Print Network [OSTI]

Hospitality Facilities Planning and Methods I (3) Management (3) #HTM 3484 Socio-Cultural Impacts of Tourism 4414 Food and Beverage Management (Pre: HTM 3414) * #HTM 4464 Human Resources Management in HospHOSPITALITY AND TOURISM MANAGEMENT MAJOR Virgu1iaTech Panplil College of BusIness Department

Virginia Tech

103

Circumstellar interaction of the type Ia supernova 2002ic  

Science Journals Connector (OSTI)

......with arguments in favour of a high-energy SN Ia event in this case, raises...WD explosion with a high kinetic energy of ejecta. The SN 1.5 origin of...2002ic-like events requires an accurate energy audit, for which the direct detection......

N. N. Chugai; R. A. Chevalier; P. Lundqvist

2004-12-01T23:59:59.000Z

104

Thermonuclear supernova models, and observations of Type Ia supernovae  

E-Print Network [OSTI]

In this paper, we review the present state of theoretical models of thermonuclear supernovae, and compare their predicitions with the constraints derived from observations of Type Ia supernovae. The diversity of explosion mechanisms usually found in one-dimensional simulations is a direct consequence of the impossibility to resolve the flame structure under the assumption of spherical symmetry. Spherically symmetric models have been successful in explaining many of the observational features of Type Ia supernovae, but they rely on two kinds of empirical models: one that describes the behaviour of the flame on the scales unresolved by the code, and another that takes account of the evolution of the flame shape. In contrast, three-dimensional simulations are able to compute the flame shape in a self-consistent way, but they still need a model for the propagation of the flame in the scales unresolved by the code. Furthermore, in three dimensions the number of degrees of freedom of the initial configuration of the white dwarf at runaway is much larger than in one dimension. Recent simulations have shown that the sensitivity of the explosion output to the initial conditions can be extremely large. New paradigms of thermonuclear supernovae have emerged from this situation, as the Pulsating Reverse Detonation. The resolution of all these issues must rely on the predictions of observational properties of the models, and their comparison with current Type Ia supernova data, including X-ray spectra of Type Ia supernova remnants.

E. Bravo; C. Badenes; D. Garcia-Senz

2004-12-07T23:59:59.000Z

105

Timothy J. Bartness Departments of Biology and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30303. Gregory E. Demas Department of Biology and Program in Neural  

E-Print Network [OSTI]

University, Bloomington, IN 47405. Neurobiology of Food and Fluid Intake, 2nd Ed., Volume 14 of Handbook, and from humans, many or most of the fundamental problems in ingestive behavior 423 #12;have not been shaped by evolu- tionary forces, we might gain greater insight into the functional and adaptive signif

Demas, Greg

106

Toughening and asymmetry in peeling of heterogeneous adhesives Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405, USA  

E-Print Network [OSTI]

at the macroscale. Our study reveals three elementary mechanisms in heterogeneous systems involving front force resulting in dramatically en- hanced resistance to peeling; (ii) optimized arrangements of pinning sites with large adhesion energy are shown to control the effective system resistance, allowing

107

ChemKey Search Database. Heterodata, Inc. 1055 Rosewood Drive, Atlanta, GA 30306. http://euch6f.chem.emory.edu/index.html. $325.00.  

Science Journals Connector (OSTI)

The database relies on text searching only; there is no provision for structural searches. ... Entering a fragment of a search term is sufficient:? for example, ion rapidly finds all citations containing words beginning with those three characters, such as ion, ionic, ionization, etc. Entering =ion finds only ion, whereas entry of *ion finds words that contain those characters at any position, including anion and cation. ... The speed of searches is impressive:? with the exception of internal string searches (using *), which may take 30 s or so, all other searches provide results within a second or two, even with multiple search terms. ...

William H. Pearson

2007-06-02T23:59:59.000Z

108

An Analysis of Department of Defense Instruction 8500.2 'Information Assurance (IA) Implementation.'  

SciTech Connect (OSTI)

The Department of Defense (DoD) provides its standard for information assurance in its Instruction 8500.2, dated February 6, 2003. This Instruction lists 157 'IA Controls' for nine 'baseline IA levels.' Aside from distinguishing IA Controls that call for elevated levels of 'robustness' and grouping the IA Controls into eight 'subject areas' 8500.2 does not examine the nature of this set of controls, determining, for example, which controls do not vary in robustness, how this set of controls compares with other such sets, or even which controls are required for all nine baseline IA levels. This report analyzes (1) the IA Controls, (2) the subject areas, and (3) the Baseline IA levels. For example, this report notes that there are only 109 core IA Controls (which this report refers to as 'ICGs'), that 43 of these core IA Controls apply without variation to all nine baseline IA levels and that an additional 31 apply with variations. This report maps the IA Controls of 8500.2 to the controls in NIST 800-53 and ITGI's CoBIT. The result of this analysis and mapping, as shown in this report, serves as a companion to 8500.2. (An electronic spreadsheet accompanies this report.)

Campbell, Philip LaRoche

2012-01-01T23:59:59.000Z

109

Learning from the scatter in type Ia supernovae  

SciTech Connect (OSTI)

Type Ia Supernovae are standard candles so their mean apparent magnitude has been exploited to learn about the redshift-distance relationship. Besides intrinsic scatter in this standard candle, additional scatter is caused by gravitational magnification by large scale structure. Here we probe the dependence of this dispersion on cosmological parameters and show that information about the amplitude of clustering, {sigma}{sub 8}, is contained in the scatter. In principle, it will be possible to constrain {sigma}{sub 8} to within 5% with observations of 2000 Type Ia Supernovae. We identify three sources of systematic error - evolution of intrinsic scatter, baryon contributions to lensing, and non-Gaussianity of lensing - which will make this measurement difficult.

Dodelson, Scott [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 (United States); Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637-1433 (United States); Vallinotto, Alberto [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 (United States); Department of Physics, The University of Chicago, Chicago, Illinois 60637-1433 (United States)

2006-09-15T23:59:59.000Z

110

RADIOACTIVELY POWERED RISING LIGHT CURVES OF TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

The rising luminosity of the recent, nearby supernova 2011fe shows a quadratic dependence with time during the first Almost-Equal-To 0.5-4 days. In addition, studies of the composite light curves formed from stacking together many Type Ia supernovae (SNe Ia) have found similar power-law indices for the rise, but may also show some dispersion that may indicate diversity. I explore what range of power-law rises are possible due to the presence of radioactive material near the surface of the exploding white dwarf (WD). I summarize what constraints such a model places on the structure of the progenitor and the distribution and velocity of ejecta. My main conclusion is that for the inferred explosion time for SN 2011fe, its rise requires an increasing mass fraction X {sub 56} Almost-Equal-To (4-6) Multiplication-Sign 10{sup -2} of {sup 56}Ni distributed between a depth of Almost-Equal-To 10{sup -2} and 0.3 M {sub Sun} below the WD's surface. Radioactive elements this shallow are not found in simulations of a single C/O detonation. Scenarios that may produce this material include helium-shell burning during a double-detonation ignition, a gravitationally confined detonation, and a subset of deflagration to detonation transition models. In general, the power-law rise can differ from quadratic depending on the details of the velocity, density, and radioactive deposition gradients in a given event. Therefore, comparisons of this work with observed bolometric rises of SNe Ia would place strong constraints on the properties of the shallow outer layers, providing important clues for identifying the elusive progenitors of SNe Ia.

Piro, Anthony L., E-mail: piro@caltech.edu [Theoretical Astrophysics, California Institute of Technology, 1200 East California Boulevard, M/C 350-17, Pasadena, CA 91125 (United States)

2012-11-10T23:59:59.000Z

111

The Diversity of Variations in the Spectra of Type Ia Supernovae  

E-Print Network [OSTI]

for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Lifan Wang Committee Members, Nicholas Suntze George Kattawar Sean McDeavitt Head of Department, George R. Welch August 2012 Major Subject: Physics iii ABSTRACT The Diversity... of Variations in the Spectra of Type Ia Supernovae. (August 2012) Andrew James Wagers, B.A., Berea College; M.S., Stephen F. Austin State University Chair of Advisory Committee: Dr. Lifan Wang Type Ia supernovae (SNe Ia) are currently the best probe...

Wagers, Andrew James

2012-10-19T23:59:59.000Z

112

Experto Universitario Java Enterprise 2012-2013 Depto. Ciencia de la Computacin e IA  

E-Print Network [OSTI]

Experto Universitario Java Enterprise © 2012-2013 Depto. Ciencia de la Computación e IA Lenguaje Lenguaje Java Avanzado © 2012-2013 Depto. Ciencia de la Computación e IA Lenguaje Java 2 Índice. Ciencia de la Computación e IA Lenguaje Java 3 Java · Java es un lenguaje OO creado por Sun Microsystems

Escolano, Francisco

113

Experto Universitario Java Enterprise 2012-2013 Depto. Ciencia de la Computacin e IA  

E-Print Network [OSTI]

Experto Universitario Java Enterprise © 2012-2013 Depto. Ciencia de la Computación e IA Lenguaje Avanzado © 2012-2013 Depto. Ciencia de la Computación e IA Depuración y logs - 2 · El depurador de Eclipse Enterprise Lenguaje Java Avanzado © 2012-2013 Depto. Ciencia de la Computación e IA Depuración y logs - 3 El

Escolano, Francisco

114

Teor'ia de Grupos y Mec'anica Qu'antica Luis A. Seco  

E-Print Network [OSTI]

determinado por el Hamiltoniano de la energ'ia, un operador que, actuando sobre una funci'on /(x 1 ; : : : ; xTeor'ia de Grupos y Mec'anica Qu'antica Luis A. Seco Universidad de Toronto. Notas del curso; Teor'ia de Grupos y Mec'anica Cu'antica, L. Seco. U.I.M.P. La Coru~na, 27 Junio -- 1 Julio, 1994

Seco, Luis A.

115

Turbulence-Flame Interactions in Type Ia Supernovae  

E-Print Network [OSTI]

The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame structure are fully resolved. The range of densities examined, 1 to $8 \\times 10^7$ g cm$^{-3}$, spans the transition from the laminar flamelet regime to the distributed burning regime where small scale turbulence disrupts the flame. The use of a low Mach number algorithm facilitates the accurate resolution of the thermal structure of the flame and the inviscid turbulent kinetic energy cascade, while implicitly incorporating kinetic energy dissipation at the grid-scale cutoff. For an assumed background of isotropic Kolmogorov turbulence with an energy characteristic of SN Ia, we find a transition density between 1 and $3 \\times 10^7$ g cm$^{-3}$ where the nature of the burning changes qualitatively. By $1 \\times 10^7$ g cm$^{-3}$, energy diffusion by conduction and radiation is exceeded, on the flame scale, by turbulent advection. As a result, the effective Lewis Number approaches unity. That is, the flame resembles a laminar flame, but is turbulently broadened with an effective diffusion coefficient, $D_T \\sim u' l$, where $u'$ is the turbulent intensity and $l$ is the integral scale. For the larger integral scales characteristic of a real supernova, the flame structure is predicted to become complex and unsteady. Implications for a possible transition to detonation are discussed.

A. J. Aspden; J. B. Bell; M. S. Day; S. E. Woosley; M. Zingale

2008-11-17T23:59:59.000Z

116

Impact of Fixed Exterior Shading on Daylighting: A Case Study of the David Brower Center  

E-Print Network [OSTI]

ASHRAE: Atlanta, GA. 4. Autodesk (2011). Ecotect Analysisbuilding design software (Autodesk, 2011). 34 Model geometry

Zelenay, Krystyna

2011-01-01T23:59:59.000Z

117

The Recurrent Nova U Scorpii - A Type Ia Supernova Progenitor  

E-Print Network [OSTI]

We derive the mass of the white dwarf in the eclipsing recurrent nova U Sco from the radial velocity semi-amplitudes of the primary and secondary stars. Our results give a high white dwarf mass of M_1 = 1.55 \\pm 0.24M_\\odot, consistent with the thermonuclear runaway model of recurrent nova outbursts. We confirm that U Sco is the best Type Ia supernova progenitor known, and predict that the time to explosion is within ~700,000 years.

T. D. Thoroughgood; V. S. Dhillon; S. P. Littlefair; T. R. Marsh; D. A. Smith

2001-09-28T23:59:59.000Z

118

Tension in the Recent Type Ia Supernovae Datasets  

E-Print Network [OSTI]

In the present work, we investigate the tension in the recent Type Ia supernovae (SNIa) datasets Constitution and Union. We show that they are in tension not only with the observations of the cosmic microwave background (CMB) anisotropy and the baryon acoustic oscillations (BAO), but also with other SNIa datasets such as Davis and SNLS. Then, we find the main sources responsible for the tension. Further, we make this more robust by employing the method of random truncation. Based on the results of this work, we suggest two truncated versions of the Union and Constitution datasets, namely the UnionT and ConstitutionT SNIa samples, whose behaviors are more regular.

Hao Wei

2010-04-07T23:59:59.000Z

119

Composition and Interface Analysis of InGaN/GaN Multiquantum...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Analysis of InGaNGaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography. Composition and Interface Analysis of InGaNGaN Multiquantum-Wells on GaN...

120

KPD1930+2752 - a candidate Type Ia supernova progenitor  

E-Print Network [OSTI]

We present spectra of the pulsating sdB star KPD1930+2752 which confirm that this star is a binary. The radial velocities measured from the H-alpha and HeI6678 spectral lines vary sinusoidally with the same period (2h 17m) as the ellipsoidal variability seen by Billeres et al. (2000). The amplitude of the orbital motion (349.3+-2.7 km/s) combined with the canonical mass for sdB stars (0.5 solar masses) implies a total mass for the binary of 1.47+-0.01 solar masses The unseen companion star is almost certainly a white dwarf star. The binary will merge within about 200 million years due to gravitational wave radiation. The accretion of helium and other elements heavier than hydrogen onto the white dwarf which then exceeds the Chandrasekhar mass (1.4 solar masses) is a viable model for the cause of Type Ia supernovae. KPD1930+2752 is the first star to be discovered which is a good candidate for the progenitor of a Type Ia supernova of this type which will merge on an astrophysically interesting timescale.

P. F. L. Maxted; T. R. Marsh; R. C. North

2000-07-18T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Search for progenitors of supnernovae type Ia with SPY  

E-Print Network [OSTI]

We have started a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (ESO SN Ia Progenitor surveY - SPY). About 400 white dwarfs were checked for radial velocity variations during the first 15 months of this project, twice the number of white dwarfs investigated during the last 20 years. We give an overview of the SPY project and present first results Fifty four new DDs have been discovered, seven of them double lined (only 18 and 6 objects of these groups were known before, respectively). The final sample is expected to contain 150 to 200 DDs. Eight new pre-cataclysmic binaries were also detected. SPY is the first DD survey which encompasses also non-DA white dwarfs. SPY produces an immense, unique sample of very high resolution white dwarf spectra, which provides a lot of spin-off opportunities. We describe our projects to exploit the SPY sample for the determination of basic parameters, kinematics, and rotational velocities of white dwarfs. A catalogue with a first subset of our white dwarf data has already been published by Koester et al. 2001.

R. Napiwotzki; N. Christlieb; H. Drechsel; H. -J. Hagen; U. Heber; D. Homeier; C. Karl; D. Koester; B. Leibundgut; T. R. Marsh; S. Moehler; G. Nelemans; E. -M. Pauli; D. Reimers; A. Renzini; L. Yungelson

2002-03-09T23:59:59.000Z

122

Meeting Briefs from Atlanta  

Science Journals Connector (OSTI)

"Certain organic materials have the undesirable property of increasing the dissolution of plutonium in groundwaters and potentially enhancing its transport away from a disposal site," says U.S. Geological Survey chemist Jess M. Cleveland. ... Cleveland and associates examined the groundwater near three plutonium disposal sites to find what chemical form the element was taking and what its chemical and hydrologie behaviors were under various environmental conditions. ... At Maxey Flats in Kentucky, for instance, where these organic agents are present, the researchers found water samples with as much as 300,000 picocuries (10 -12 curie) of plutonium per liter. ...

1981-04-13T23:59:59.000Z

123

GaN High Power Devices  

SciTech Connect (OSTI)

A brief review is given of recent progress in fabrication of high voltage GaN and AlGaN rectifiers, GaN/AlGaN heterojunction bipolar transistors, GaN heterostructure and metal-oxide semiconductor field effect transistors. Improvements in epitaxial layer quality and in fabrication techniques have led to significant advances in device performance.

PEARTON,S.J.; REN,F.; ZHANG,A.P.; DANG,G.; CAO,X.A.; LEE,K.P.; CHO,H.; GILA,B.P.; JOHNSON,J.W.; MONIER,C.; ABERNATHY,C.R.; HAN,JUNG; BACA,ALBERT G.; CHYI,J.-I.; LEE,C.-M.; NEE,T.-E.; CHUO,C.-C.; CHI,G.C.; CHU,S.N.G.

2000-07-17T23:59:59.000Z

124

Search for double degenerate progenitors of supernovae type Ia with SPY  

E-Print Network [OSTI]

We report on a large survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae with the UVES spectrograph at the ESO VLT (SN Ia Progenitor surveY - SPY). About 560 white dwarfs were checked for radial velocity variations until now. Ninety new DDs have been discovered, including short period systems with masses close to the Chandrasekhar mass.

R. Napiwotzki; N. Christlieb; H. Drechsel; H. -J. Hagen; U. Heber; D. Homeier; C. Karl; D. Koester; B. Leibundgut; T. R. Marsh; S. Moehler; G. Nelemans; E. -M. Pauli; D. Reimers; A. Renzini; L. Yungelson

2002-10-29T23:59:59.000Z

125

Analytical Expressions For Light-Curves Of Ordinary And Superluminous Supernovae Type Ia  

E-Print Network [OSTI]

Ordinary supernovae of type Ia (SNeIa) may be produced by the thermonuclear explosion of white dwarfs (WDs), which after their nascence in proto-planetary nebulae accrete fall-back matter and approach the Chandrasekhar mass limit. If the detonation continues into the fall-back layer and/or if the SNIa debris collide with it, they may produce a super Chandrasekhar SNIa. A few underlying physical assumptions of such model yield a very simple master formula that reproduces quite well the bolometric light-curves of both ordinary and supeluminous SNeIa. Other main properties of SNeIa, including the empirical 'brighter-slower' Philipps' relation that was used to standardize ordinary SNeIa as distance indicators and led to the discovery of the accelerating expansion of the universe are also reproduced.

Shlomo Dado; Arnon Dar

2014-02-06T23:59:59.000Z

126

Type Ia supernova rate studies from the SDSS-II Supernova Study  

SciTech Connect (OSTI)

The author presents new measurements of the type Ia SN rate from the SDSS-II Supernova Survey. The SDSS-II Supernova Survey was carried out during the Fall months (Sept.-Nov.) of 2005-2007 and discovered {approx} 500 spectroscopically confirmed SNe Ia with densely sampled (once every {approx} 4 days), multi-color light curves. Additionally, the SDSS-II Supernova Survey has discovered several hundred SNe Ia candidates with well-measured light curves, but without spectroscopic confirmation of type. This total, achieved in 9 months of observing, represents {approx} 15-20% of the total SNe Ia discovered worldwide since 1885. The author describes some technical details of the SN Survey observations and SN search algorithms that contributed to the extremely high-yield of discovered SNe and that are important as context for the SDSS-II Supernova Survey SN Ia rate measurements.

Dilday, Benjamin; /Chicago U.

2008-08-01T23:59:59.000Z

127

Type Ia supernovae selection and forecast of cosmology constraints for the Dark Energy Survey  

Science Journals Connector (OSTI)

We present the results of a study of selection criteria to identify Type Ia supernovae photometrically in a simulated mixed sample of Type Ia supernovae and core collapse supernovae. The simulated sample is a mockup of the expected results of the Dark Energy Survey. Fits to the \\{MLCS2k2\\} and SALT2 Type Ia supernova models are compared and used to help separate the Type Ia supernovae from the core collapse sample. The Dark Energy Task Force Figure of Merit (modified to include core collapse supernovae systematics) is used to discriminate among the various selection criteria. This study of varying selection cuts for Type Ia supernova candidates is the first to evaluate core collapse contamination using the Figure of Merit. Different factors that contribute to the Figure of Merit are detailed. With our analysis methods, both SALT2 and \\{MLCS2k2\\} Figures of Merit improve with tighter selection cuts and higher purities, peaking at 98% purity.

Eda Gjergo; Jefferson Duggan; John D. Cunningham; Steve Kuhlmann; Rahul Biswas; Eve Kovacs; Joseph P. Bernstein; Harold Spinka

2013-01-01T23:59:59.000Z

128

Category:Savannah, GA | Open Energy Information  

Open Energy Info (EERE)

Savannah, GA Savannah, GA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Savannah, GA" The following 16 files are in this category, out of 16 total. SVFullServiceRestaurant Savannah GA Georgia Power Co.png SVFullServiceRestauran... 80 KB SVHospital Savannah GA Georgia Power Co.png SVHospital Savannah GA... 80 KB SVLargeHotel Savannah GA Georgia Power Co.png SVLargeHotel Savannah ... 75 KB SVLargeOffice Savannah GA Georgia Power Co.png SVLargeOffice Savannah... 82 KB SVMediumOffice Savannah GA Georgia Power Co.png SVMediumOffice Savanna... 85 KB SVMidriseApartment Savannah GA Georgia Power Co.png SVMidriseApartment Sav... 80 KB SVOutPatient Savannah GA Georgia Power Co.png SVOutPatient Savannah ... 84 KB SVPrimarySchool Savannah GA Georgia Power Co.png

129

GA SNC Solar | Open Energy Information  

Open Energy Info (EERE)

GA SNC Solar Jump to: navigation, search Name: GA-SNC Solar Place: Nevada Sector: Solar Product: Nevada-based PV project developer and joint venture of GA-Solar North America and...

130

Microsoft PowerPoint - IEEE IAS PES 102313.pptx  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

DOE's ARRA DOE's ARRA Smart Grid Program Steve Bossart, Senior Energy Analyst IEEE IAS/PES Pittsburgh Section October 23, 2013 ‹#› Topics * OE ARRA Smart Grid Program * OE ARRA Smart Grid Progress * Results and Case Studies * Life After ARRA Smart Grid ‹#› DOE OE ARRA Smart Grid Program ‹#› American Recovery and Reinvestment Act ($4.5B) * Smart Grid Investment Grants (99 projects) - $3.4 billion Federal; $4.7 billion private sector - > 800 PMUs covering almost 100% of transmission - ~ 8000 distribution automation circuits - > 15 million smart meters * Smart Grid Demonstration Projects (32 projects) - $685 million Federal; $1 billion private sector - 16 storage projects - 16 regional demonstrations Smart Grid ARRA Activities ‹#› Smart Grid investment from ARRA field projects

131

Type Ia Supernova: Burning and Detonation in the Distributed Regime  

E-Print Network [OSTI]

A simple, semi-analytic representation is developed for nuclear burning in Type Ia supernovae in the special case where turbulent eddies completely disrupt the flame. The speed and width of the ``distributed'' flame front are derived. For the conditions considered, the burning front can be considered as a turbulent flame brush composed of corrugated sheets of well-mixed flames. These flames are assumed to have a quasi-steady-state structure similar to the laminar flame structure, but controlled by turbulent diffusion. Detonations cannot appear in the system as long as distributed flames are still quasi-steady-state, but this condition is violated when the distributed flame width becomes comparable to the size of largest turbulent eddies. When this happens, a transition to detonation may occur. For current best estimates of the turbulent energy, the most likely density for the transition to detonation is in the range 0.5 - 1.5 x 10^7 g cm^{-3}.

S. E. Woosley

2007-09-26T23:59:59.000Z

132

SciTech Connect: enriched uranium  

Office of Scientific and Technical Information (OSTI)

enriched uranium Find enriched uranium Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

133

SciTech Connect: auroras  

Office of Scientific and Technical Information (OSTI)

auroras Find auroras Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

134

SciTech Connect: "plasma science"  

Office of Scientific and Technical Information (OSTI)

plasma science" Find plasma science" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

135

SciTech Connect: "Greenhouse Effect"  

Office of Scientific and Technical Information (OSTI)

Greenhouse Effect" Find Greenhouse Effect" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

136

SciTech Connect: higgs  

Office of Scientific and Technical Information (OSTI)

higgs Find higgs Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

137

SciTech Connect: "fuel cells"  

Office of Scientific and Technical Information (OSTI)

fuel cells" Find fuel cells" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

138

SciTech Connect: plasma  

Office of Scientific and Technical Information (OSTI)

plasma Find plasma Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

139

SciTech Connect: "enriched uranium"  

Office of Scientific and Technical Information (OSTI)

enriched uranium" Find enriched uranium" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

140

SciTech Connect: "oil shale"  

Office of Scientific and Technical Information (OSTI)

oil shale" Find oil shale" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

SciTech Connect: "higgs boson"  

Office of Scientific and Technical Information (OSTI)

higgs boson" Find higgs boson" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

142

SciTech Connect: "geomagnetic storms"  

Office of Scientific and Technical Information (OSTI)

geomagnetic storms" Find geomagnetic storms" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

143

Type Ia Supernova Hubble Residuals and Host-Galaxy Properties  

SciTech Connect (OSTI)

Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spec- trophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ? 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at ? 1?, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement the Hubble residual step with host mass is 0.045 ? 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch param- eters: Steps at> 2? significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light- curve width and color around peak (similar to the?m15 and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20 to 30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.

Nearby Supernova Factory; Kim, A. G.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Feindt, U.; Fleury, M.; Gangler, E.; Greskovic, P.; Guy, J.; Kowalski, M.; Lombardo, S.; Nordin, J.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Saunders, C.; Scalzo, R.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.

2014-01-17T23:59:59.000Z

144

A mutant of Escherichia coli defective in penicillin-binding protein 5 and lacking D-alanine carboxypeptidase IA.  

Science Journals Connector (OSTI)

...preparation of D-alanrne car- boxypeptidase IA of...IA, because a mutant defective in D-alanine carbox...both activities were defective or both were normal...residual D-alanine car- boxypeptidase IA activity...and to obtain a mutant defective in PBP-6 are in progress...

Y Nishimura; H Suzuki; Y Hirota; J T Park

1980-07-01T23:59:59.000Z

145

GaN/AlGaN ultraviolet/infrared dual-band detector G. Ariyawansa, M. B. M. Rinzan, M. Alevli, M. Strassburg, N. Dietz, and A. G. U. Pereraa  

E-Print Network [OSTI]

, Atlanta, Georgia 30303 S. G. Matsik NDP Optronics, Mableton, Georgia 30126 A. Asghar and I. T. Ferguson

Perera, A. G. Unil

146

Building America Technology Solutions for New and Existing Homes...  

Energy Savers [EERE]

Atlanta, Georigia (Fact Sheet), This case study describes the construction of a new test home in Atlanta, GA, that demonstrates current best practices for the mixed-humid...

147

RECYCLING: SUPPLY, ECONOMICS, ENVIRONMENT, AND TECHNOLOGY  

E-Print Network [OSTI]

Proceedings Technology Park/Atlanta P. O. Box 105113 Atlanta, GA 303+8-5113, USA on recycled paper 416 / TAPPI

Abubakr, Said

148

Stellar Populations and the White Dwarf Mass Function: Connections To Supernova Ia Luminosities  

E-Print Network [OSTI]

We discuss the luminosity function of SNe Ia under the assumption that recent evidence for dispersion in this standard candle is related to variations in the white dwarf mass function (WDMF) in the host galaxies. We develop a simple parameterization of the WDMF as a function of age of a stellar population and apply this to galaxies of different morphological types. We show that this simplified model is consistent with the observed WDMF of Bergeron et al. (1992) for the solar neighborhood. Our simple models predict that WDMF variations can produce a range of more than 1.8 mag in M$_B$(SN Ia), which is comparable to the observed value using the data of Phillips (1993) and van den Bergh (1996). We also predict a galaxy type dependence of M$_B$(SN Ia) under standard assumptions of the star formation history in these galaxies and show that M$_B$(SN Ia) can evolve with redshift. In principle both evolutionary and galaxy type corrections should be applied to recover the intrinsic range of M$_B$(SN Ia) from the observed values. Our current inadequate knowledge of the star formation history of galaxies coupled with poor physical understanding of the SN Ia mechanism makes the reliable estimation of these corrections both difficult and controversial. The predictions of our models combined with the observed galaxy and redshift correlations may have the power to discriminate between the Chandrasekhar and the sub-Chandrasekhar progenitor scenarios for SNe Ia.

Ted von Hippel; G. D. Bothun; R. A. Schommer

1997-06-11T23:59:59.000Z

149

Beta decay of Ga-62  

E-Print Network [OSTI]

We report a study of the beta decay of Ga-62, whose dominant branch is a superallowed 0(+)-->0(+) transition to the ground state of Zn-62. We find the total half-life to be 115.84+/-0.25 ms. This is the first time that the Ga-62 half-life has been...

Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.

2003-01-01T23:59:59.000Z

150

Tension and Systematics in the Gold06 SnIa Dataset  

E-Print Network [OSTI]

The Gold06 SnIa dataset recently released in astro-ph/0611572 consists of five distinct subsets defined by the group or instrument that discovered and analyzed the corresponding data. These subsets are: the SNLS subset (47 SnIa), the HST subset (30 SnIa), the HZSST subset (41 SnIa), the SCP subset (26 SnIa) and the Low Redshift (LR) subset (38 SnIa). These subsets sum up to the 182 SnIa of the Gold06 dataset. We use Monte-Carlo simulations to study the statistical consistency of each one of the above subsets with the full Gold06 dataset. In particular, we compare the best fit $w(z)$ parameters (w_0,w_1) obtained by subtracting each one of the above subsets from the Gold06 dataset (subset truncation), with the corresponding best fit parameters (w^r_0,w^r_1) obtained by subtracting the same number of randomly selected SnIa from the same redshift range of the Gold06 dataset (random truncation). We find that the probability for (w^r_0,w^r_1)=(w_0,w_1) is large for the Gold06 minus SCP (Gold06-SCP) truncation but is less than 5% for the Gold06-SNLS, Gold06-HZSST and Gold06-HST truncations. This result implies that the Gold06 dataset is not statistically homogeneous. By comparing the values of the best fit (w_0,w_1) for each subset truncation we find that the tension among subsets is such that the SNLS and HST subsets are statistically consistent with each other and `pull' towards LCDM (w_0=-1,w_1=0) while the HZSST subset is statistically distinct and strongly `pulls' towards a varying w(z) crossing the line $w=-1$ from below (w_00). We also isolate six SnIa that are mostly responsible for this behavior of the HZSST subset.

S. Nesseris; L. Perivolaropoulos

2007-01-09T23:59:59.000Z

151

Solar abundance of manganese: a case for the existence of near Chandrasekhar-mass Type Ia supernova progenitors  

E-Print Network [OSTI]

Context: Manganese is predominantly synthesised in Type Ia supernova (SN Ia) explosions. Owing to the entropy dependence of the Mn yield in explosive thermonuclear burning, SNe Ia involving near Chandrasekhar-mass white dwarfs (WDs) are predicted to produce Mn to Fe ratios significantly exceeding those of SN Ia explosions involving sub-Chandrasekhar mass primary WDs. Of all current supernova explosion models, only SN Ia models involving near-Chandrasekhar mass WDs produce [Mn/Fe] > 0.0. Aims: Using the specific yields for competing SN Ia scenarios, we aim to constrain the relative fractions of exploding near-Chandrasekhar mass to sub-Chandrasekhar mass primary WDs in the Galaxy. Methods: We extract the Mn yields from three-dimensional thermonuclear supernova simulations referring to different initial setups and progenitor channels. We then compute the chemical evolution of Mn in the Solar neighborhood, assuming SNe Ia are made up of different relative fractions of the considered explosion models. Results: We ...

Seitenzahl, Ivo R; Roepke, Friedrich K; Ruiter, Ashley J

2013-01-01T23:59:59.000Z

152

INDECOMPOSABLE RACKS OF ORDER p2 MAT'IAS GRA"NA  

E-Print Network [OSTI]

INDECOMPOSABLE RACKS OF ORDER p2 MAT'IAS GRA"NA Abstract.We classify indecomposable racks of order p2(p a prime). There a of prime order is trivial. 1.Introduction Racks and quandles have

Graña, Matías

153

Structural studies of allosteric regulation in the class Ia Ribonucleotide reductase from Escherichia coli  

E-Print Network [OSTI]

Ribonucleotide reductase (RNR) converts ribonucleotides to deoxyribonucleotides, the building blocks for DNA replication and repair. The E. coli class Ia enzyme requires two subunits to catalyze the radical-based reduction ...

Zimanyi, Christina Marie

2013-01-01T23:59:59.000Z

154

Type Ia supernova rate at a redshift of ~;0.1  

SciTech Connect (OSTI)

We present the type Ia rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type Ia were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type Ia supernova explosion rate at a redshift {approx} 0.13. The result is 0.125{sub -0.034-0.028}{sup +0.044+0.028} h{sub 70}{sup 2} SNu where 1 SNu = 1 SN/10{sup 10} L{sub {circle_dot}}{sup B}/century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type Ia supernova rate.

Blanc, G.; Afonso, C.; Alard, C.; Albert, J.N.; Aldering, G.; Amadon, A.; Andersen, J.; Ansari, R.; Aubourg, E.; Balland, C.; Bareyre,P.; Beaulieu, J.P.; Charlot, X.; Conley, A.; Coutures, C.; Dahlen, T.; Derue, F.; Fan, X.; Ferlet, R.; Folatelli, G.; Fouque, P.; Garavini, G.; Glicenstein, J.F.; Goldman, B.; Goobar, A.; Gould, A.; Graff, D.; Gros,M.; Haissinski, J.; Hamadache, C.; Hardin, D.; Hook, I.M.; deKat, J.; Kent, S.; Kim, A.; Lasserre, T.; LeGuillou, L.; Lesquoy, E.; Loup, C.; Magneville, C.; Marquette, J.B.; Maurice, E.; Maury, A.; Milsztajn, A.; Moniez, M.; Mouchet, M.; Newberg, H.; Nobili, S.; Palanque-Delabrouille,N.; Perdereau, O.; Prevot, L.; Rahal, Y.R.; Regnault, N.; Rich, J.; Ruiz-Lapuente, P.; Spiro, M.; Tisserand, P.; Vidal-Madjar, A.; Vigroux,L.; Walton, N.A.; Zylberajch, S.

2004-05-11T23:59:59.000Z

155

~ VII -ATTiVIT EDILIZIE .. Servizio di Ateneo per lEnergIa  

E-Print Network [OSTI]

~ VII - ATTiVIT? EDILIZIE n'p. .' .. Servizio di Ateneo per lEnergIa - N AlJZ43 ········ - .·:tri

Di Pillo, Gianni

156

Infrastructure Assessment Mission: USACE Infrastructure Assessment (IA) Planning and Response Teams (PRTs) have two main  

E-Print Network [OSTI]

, and structural engineering applications; urban search & rescue (US&R) support; and water/wastewater) include pre- and post-declaration support for deploying an IA management cell, water/wastewater assessment

US Army Corps of Engineers

157

Gamma-rays from Type Ia supernova SN2014J  

E-Print Network [OSTI]

The whole set of INTEGRAL observations of type Ia supernova SN2014J, covering the period 16-162 days after the explosion has being analyzed. For spectral fitting the data are split into early and late periods covering days 16-35 and 50-162, respectively, optimized for Ni-56 and Co-56 lines. As expected for the early period much of the gamma-ray signal is confined to energies below $\\sim$200 keV, while for the late period it is most strong above 400 keV. In particular, in the late period Co-56 lines at 847 and 1248 keV are detected at 4.7 and 4.3 sigma respectively. The lightcurves in several representative energy bands are calculated for the entire period. The resulting spectra and lightcurves are compared with a subset of models. We confirm our previous finding that the gamma-ray data are broadly consistent with the expectations for canonical 1D models, such as delayed detonation or deflagration models for a near-Chandrasekhar mass WD. Late optical spectra (day 136 after the explosion) show rather symmetric ...

Churazov, E; Isern, J; Bikmaev, I; Bravo, E; Chugai, N; Grebenev, S; Jean, P; Kndlseder, J; Lebrun, F; Kuulkers, E

2015-01-01T23:59:59.000Z

158

GaAs, AlGaAs and InGaP Tunnel Junctions for Multi-Junction Solar Cells Under Concentration: Resistance Study  

SciTech Connect (OSTI)

The following four TJ designs, AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs are studied to determine minimum doping concentration to achieve a resistance of <10{sup -4} {omega}{center_dot}cm{sup 2} and a peak tunneling current suitable for MJ solar cells up to 1500-suns concentration (operating current of 21 A/cm{sup 2}). Experimentally calibrated numerical models are used to determine how the resistance changes as a function of doping concentration. The AlGaAs/GaAs TJ design is determined to require the least doping concentration to achieve the specified resistance and peak tunneling current, followed by the GaAs/GaAs, and AlGaAs/AlGaAs TJ designs. The AlGaAs/InGaP TJ design can only achieve resistances >5x10{sup -4} {omega}cm{sup 2}.

Wheeldon, Jeffrey F.; Valdivia, Christopher E.; Walker, Alex; Kolhatkar, Gitanja; Hall, Trevor J.; Hinzer, Karin [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada); Masson, Denis; Riel, Bruno; Fafard, Simon [Cyrium Technologies Inc., Ottawa, ON (Canada); Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent [Centre de Recherche en Nanofabrication et en Nanocaracterisation CRN2, Universite de Sherbrooke, Sherbrooke, QC (Canada)

2010-10-14T23:59:59.000Z

159

2010-2011 Depto. Ciencia de la Computacin e IA Especialista Universitario Java Enterprise  

E-Print Network [OSTI]

© 2010-2011 Depto. Ciencia de la Computación e IA Especialista Universitario Java Enterprise Struts Sesión 4: Introducción a Struts 2 #12;© 2010-2011 Depto. Ciencia de la Computación e IA Especialista · Taglibs · Internacionalización · Validación · Conceptos nuevos en Struts 2 #12;© 2010-2011 Depto. Ciencia

Escolano, Francisco

160

Experto Universitario Java Enterprise 2012-2013 Depto. Ciencia de la Computacin e IA  

E-Print Network [OSTI]

Experto Universitario Java Enterprise © 2012-2013 Depto. Ciencia de la Computación e IA Lenguaje Java Avanzado Sesión 3: Tratamiento de errores #12;Lenguaje Java Avanzado © 2012-2013 Depto. Ciencia de · Tipos genéricos #12;Lenguaje Java Avanzado © 2012-2013 Depto. Ciencia de la Computación e IA Errores - 3

Escolano, Francisco

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Constraining the double-degenerate scenario for Type Ia supernovae from merger ejected matter  

E-Print Network [OSTI]

We follow the mass blown during the WD-WD merger process in the Double-Degenerate (DD) scenario for type Ia supernovae (SN Ia), and find that the interaction of the SN ejecta with this wind affects the early (thermal energy and then to additional radiation. The radiation could be interpreted as an explosion originating from a progenitor having a radius of one solar radius or more, contradicting observations of SN 2011fe.

Levanon, Naveh; Garca-Berro, Enrique

2014-01-01T23:59:59.000Z

162

THE DISCOVERY OF THE MOST DISTANT KNOWN TYPE Ia SUPERNOVA AT REDSHIFT 1.914  

SciTech Connect (OSTI)

We present the discovery of a Type Ia supernova (SN) at redshift z = 1.914 from the CANDELS multi-cycle treasury program on the Hubble Space Telescope (HST). This SN was discovered in the infrared using the Wide-Field Camera 3, and it is the highest-redshift Type Ia SN yet observed. We classify this object as a SN Ia by comparing its light curve and spectrum with those of a large sample of Type Ia and core-collapse SNe. Its apparent magnitude is consistent with that expected from the {Lambda}CDM concordance cosmology. We discuss the use of spectral evidence for classification of z > 1.5 SNe Ia using HST grism simulations, finding that spectral data alone can frequently rule out SNe II, but distinguishing between SNe Ia and SNe Ib/c can require prohibitively long exposures. In such cases, a quantitative analysis of the light curve may be necessary for classification. Our photometric and spectroscopic classification methods can aid the determination of SN rates and cosmological parameters from the full high-redshift CANDELS SN sample.

Jones, David O.; Rodney, Steven A.; Riess, Adam G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Dahlen, Tomas; Casertano, Stefano; Koekemoer, Anton [Space Telescope Science Institute, Baltimore, MD 21218 (United States); McCully, Curtis; Keeton, Charles R.; Patel, Brandon [Department of Physics and Astronomy, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States); Frederiksen, Teddy F.; Hjorth, Jens [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Strolger, Louis-Gregory [Department of Physics, Western Kentucky University, Bowling Green, KY 42101 (United States); Wiklind, Tommy G. [Joint ALMA Observatory, ESO, Santiago (Chile); Challis, Peter [Harvard/Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Graur, Or [School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Hayden, Brian; Garnavich, Peter [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Weiner, Benjamin J. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); and others

2013-05-10T23:59:59.000Z

163

CIMAT, VIII Escuela de verano, 30 de julio -12 de agos* Introducci'on a la Geometr'ia de la Mec'anic*  

E-Print Network [OSTI]

* *fluencia de una fuerza F(x) se define su energ'ia (como funci'on de su posici'on y velocidad) por E = T +* * V donde la energ'ia cin'etica T = m(x`)2=2 y la energ'ia potencial V (x) es una funci'on que(x) entonces su energ* *'ia E se mantiene constante en el tiempo (la Ley de Conservaci'on de Energ'ia

Bor, Gil

164

Novel GaAs Devices  

Science Journals Connector (OSTI)

As the dimensions of GaAs devices shrink, the effective electron velocity should increase, leading to a shorter transit time and to a ballistic or near-ballistic mode of operation (see Chapter 2). At the same ...

Michael Shur

1987-01-01T23:59:59.000Z

165

Characterisation of Ga-coated and Ga-brazed aluminium  

SciTech Connect (OSTI)

This work is devoted to the brazing of aluminium using liquid gallium. Gallium was deposited on aluminium samples at {approx} 50 Degree-Sign C using a liquid gallium 'polishing' technique. Brazing was undertaken for 30 min at 500 Degree-Sign C in air. EDS (Energy Dispersive X-ray Spectroscopy) and AES (Auger Electron Spectroscopy) characterisation of Ga-coated samples has shown that the Ga surface layer thickness is of ten (or a few tens of) nanometres. Furthermore, aluminium oxide layer (Al{sub 2}O{sub 3}) was shown to be 'descaled' during Ga deposition, which ensures good conditions for further brazing. Cross-section examination of Ga-coated samples shows that liquid gallium penetrates into the aluminium grain boundaries during deposition. The thickness of the grain boundary gallium film was measured using an original EDS technique and is found to be of a few tens of nanometres. The depth of gallium grain boundary penetration is about 300 {mu}m at the deposition temperature. The fracture stress of the brazed joints was measured from tensile tests and was determined to be 33 MPa. Cross-section examination of brazed joints shows that gallium has fully dissolved into the bulk and that the joint is really autogenous. - Highlights: Black-Right-Pointing-Pointer Aluminium can be brazed using liquid gallium deposited by a 'polishing' technique. Black-Right-Pointing-Pointer The aluminium oxide layer is 'descaled' during liquid Ga 'polishing' deposition. Black-Right-Pointing-Pointer EDS can be used for determination of surface and grain boundary Ga film thickness. Black-Right-Pointing-Pointer The surface and grain boundary Ga film thickness is of a few tens of nm. Black-Right-Pointing-Pointer Surface and grain boundary gallium dissolves in the bulk during brazing.

Ferchaud, E. [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Christien, F., E-mail: frederic.christien@univ-nantes.fr [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France); Barnier, V. [Ecole Nationale Superieure des Mines, MPI, CNRS UMR5146, Centre SMS, 158 Cours Fauriel, 42023 Saint Etienne (France); Paillard, P. [Universite de Nantes, Polytech'Nantes, Laboratoire Genie des Materiaux et Procedes Associes, Rue Christian Pauc, 44306 Nantes Cedex 3 (France)

2012-05-15T23:59:59.000Z

166

Verifying the Cosmological Utility of Type Ia Supernovae: Implications of a Dispersion in the Ultraviolet Spectra  

SciTech Connect (OSTI)

We analyze the mean rest-frame ultraviolet (UV) spectrum of Type Ia Supernovae (SNe) and its dispersion using high signal-to-noise ratio Keck-I/LRIS-B spectroscopy for a sample of 36 events at intermediate redshift (z=0.5) discovered by the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). We introduce a new method for removing host galaxy contamination in our spectra, exploiting the comprehensive photometric coverage of the SNLS SNe and their host galaxies, thereby providing the first quantitative view of the UV spectral properties of a large sample of distant SNe Ia. Although the mean SN Ia spectrum has not evolved significantly over the past 40percent of cosmic history, precise evolutionary constraints are limited by the absence of a comparable sample of high-quality local spectra. The mean UV spectrum of our z~;;=0.5 SNe Ia and its dispersion is tabulated for use in future applications. Within the high-redshift sample, we discover significant UV spectral variations and exclude dust extinction as the primary cause by examining trends with the optical SN color. Although progenitor metallicity may drive some of these trends, the variations we see are much larger than predicted in recent models and do not follow expected patterns. An interesting new result is a variation seen in the wavelength of selected UV features with phase. We also demonstrate systematic differences in the SN Ia spectral features with SN light curve width in both the UV and the optical. We show that these intrinsic variations could represent a statistical limitation in the future use of high-redshift SNe Ia for precision cosmology. We conclude that further detailed studies are needed, both locally and at moderate redshift where the rest-frame UV can be studied precisely, in order that future missions can confidently be planned to fully exploit SNe Ia as cosmological probes.

Nugent, Peter E; Ellis, R.S.; Sullivan, M.; Nugent, P.E.; Howell, D.A.; Gal-Yam, A.; Astier, P.; Balam, D.; Balland, C.; Basa, S.; Carlberg, R.; Conley, A.; Fouchez, D.; Guy, J.; Hardin, D.; Hook, I.; Pain, R.; Perrett, K.; Pritchet, C.J.; Regnault, N.

2008-02-28T23:59:59.000Z

167

Utilizing Type Ia Supernovae in a Large, Fast, Imaging Survey to Constrain Dark Energy  

E-Print Network [OSTI]

We study the utility of a large sample of type Ia supernovae that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider information from the traditional luminosity distance test as well as the spread in SNeIa fluxes at fixed redshift induced by gravitational lensing. We include a treatment of photometric redshift uncertainties in our analysis. Our primary result is that the information contained in the mean distance moduli of SNeIa and the dispersion among SNeIa distance moduli complement each other, breaking a degeneracy between the present dark energy equation of state and its time variation without the need for a high-redshift supernova sample. To address photometric redshift uncertainties, we present dark energy constraints as a function of the size of an external set of spectroscopically-observed SNeIa that may be used for redshift calibration, nspec. We find that an imaging survey can constrain the dark energy equation of state at the epoch where it is best constrained with a 1-sigma error of sigma(wpiv)~0.03-0.09$, depending upon various assumptions. In addition, the marginal improvement in the error sigma(wpiv) from an increase in the spectroscopic calibration sample drops once nspec ~ 10^3. This result is important because it is of the order of the size of calibration samples likely to be compiled in the coming decade and because, for samples of this size, the spectroscopic and imaging surveys individually place comparable constraints on the dark energy equation of state. In all cases, it is best to calibrate photometric redshifts with a set of spectroscopically-observed SNeIa with relatively more objects at high redshift than the parent sample of imaging SNeIa.

Andrew R. Zentner; Suman Bhattacharya

2008-12-01T23:59:59.000Z

168

Intense terahertz emission from molecular beam epitaxy-grown GaAs/GaSb(001)  

SciTech Connect (OSTI)

Intense terahertz (THz) electromagnetic wave emission was observed in undoped GaAs thin films deposited on (100) n-GaSb substrates via molecular beam epitaxy. GaAs/n-GaSb heterostructures were found to be viable THz sources having signal amplitude 75% that of bulk p-InAs. The GaAs films were grown by interruption method during the growth initiation and using various metamorphic buffer layers. Reciprocal space maps revealed that the GaAs epilayers are tensile relaxed. Defects at the i-GaAs/n-GaSb interface were confirmed by scanning electron microscope images. Band calculations were performed to infer the depletion region and electric field at the i-GaAs/n-GaSb and the air-GaAs interfaces. However, the resulting band calculations were found to be insufficient to explain the THz emission. The enhanced THz emission is currently attributed to a piezoelectric field induced by incoherent strain and defects.

Sadia, Cyril P.; Laganapan, Aleena Maria; Agatha Tumanguil, Mae; Estacio, Elmer; Somintac, Armando; Salvador, Arnel [National Institute of Physics, University of the Philippines Diliman, Quezon City 1101 (Philippines); Que, Christopher T. [Physics Department, De La Salle University, 2401 Taft Avenue, Manila 1004 (Philippines); Yamamoto, Kohji; Tani, Masahiko [Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507 (Japan)

2012-12-15T23:59:59.000Z

169

Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report  

SciTech Connect (OSTI)

Type Ia supernovae (SNe Ia; exploding white-dwarf stars) were the key to the Nobel-worthy 1998 discovery and subsequent verification that the expansion of the Universe is accelerating, driven by the effects of dark energy. Understanding the nature of this mysterious, yet dominant, component of the Universe is at the forefront of research in cosmology and fundamental physics. SNe Ia will continue to play a leading role in this enterprise, providing precise cosmological distances that improve constraints on the nature of dark energy. However, for this effort to succeed, we need to more thoroughly understand relatively nearby SNe Ia, because our conclusions come only from comparisons between them and distant (high-redshift) SNe Ia. Thus, detailed studies of relatively nearby SNe Ia are the focus of this research program. Many interesting results were obtained during the course of this project; these were published in 32 refereed research papers that acknowledged the grant. A major accomplishment was the publication of supernova (SN) rates derived from about a decade of operation of the Lick Observatory Supernova Search (LOSS) with the 0.76-meter Katzman Automatic Imaging Telescope (KAIT). We have determined the most accurate rates for SNe of different types in large, nearby galaxies in the present-day Universe, and these can be compared with SN rates far away (and hence long ago in the past) to set constraints on the types of stars that explode. Another major accomplishment was the publication of the light curves (brightness vs. time) of 165 SNe Ia, along with optical spectroscopy of many of these SNe as well as other SNe Ia, providing an extensive, homogeneous database for detailed studies. We have conducted intensive investigations of a number of individual SNe Ia, including quite unusual examples that allow us to probe the entire range of SN explosions and provide unique insights into these objects and the stars before they explode. My team's studies have also led to the identification of subsamples of SNe Ia that can be used to provide the most reliable cosmological distances, and we developed ways to deal with the dust that makes SNe Ia appear fainter than they really are. Using the KAIT/LOSS sample, we produced an excellent Hubble diagram (galaxy recession speed vs. distance), accurately showing the expansion of the Universe. Even smaller scatter was achieved when spectroscopic characteristics were taken into account. Another high-quality Hubble diagram was constructed with SNe Ia from the Sloan Digital Sky Survey (SDSS). These Hubble diagrams provide useful new constraints on the nature of the dark energy that is accelerating the expansion of the Universe. As an added bonus of our research, we also studied core-collapse SNe, which differ fundamentally from SNe Ia.

Filippenko, Alexei Vladimir [Univ. California, Berkeley

2014-05-09T23:59:59.000Z

170

3/5/09 11:36 AMTech composes the music of fish | ajc.com Page 1 of 3http://www.ajc.com/metro/content/metro/atlanta/stories/2009/02/22/tech_music_fish.html  

E-Print Network [OSTI]

3/5/09 11:36 AMTech composes the music of fish | ajc.com Page 1 of 3http://www.ajc.com/metro/content/metro/atlanta/stories/2009/02/22/tech_music_fish.html Enlarge this image CURTIS COMPTON / ccompton@ajc.com Dr. Bruce Walker (right), project lead, and researcher Carrie Bruce watch fish during work on a Center for Music

171

New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems  

SciTech Connect (OSTI)

GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

2005-11-01T23:59:59.000Z

172

High Efficiency Large Area AlGaAs/GaAs Concentrator Solar Cells  

Science Journals Connector (OSTI)

A 1-kWp ( peak at 100 mw/cm2 incident power dencity ) concentrating photovoltaic array with 180 square Presnel plastic lenses and AlGaAs/GaAs concentrator solar cells has been constructed. The AlGaAs/GaAs concetr...

S. Yoshida; K. Mitsui; T. Oda; Y. Yukimoto

1981-01-01T23:59:59.000Z

173

GaSb/GaAs type II quantum dot solar cells for enhanced infrared spectral response  

E-Print Network [OSTI]

GaSb/GaAs type II quantum dot solar cells for enhanced infrared spectral response R. B Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 Received 27 infrared spectral response of GaAs-based solar cells that incorporate type II GaSb quantum dots QDs formed

Jalali. Bahram

174

Self-aligned AlGaN/GaN transistors for sub-mm wave applications  

E-Print Network [OSTI]

This thesis describes work done towards realizing self-aligned AlGaN/GaN high electron mobility transistors (HEMTs). Self-aligned transistors are important for improving the frequency of AlGaN/GaN HEMTs by reducing source ...

Saadat, Omair I

2010-01-01T23:59:59.000Z

175

Plasmonic nanoparticle enhanced photocurrent in GaN/InGaN/GaN quantum well solar cells  

E-Print Network [OSTI]

Plasmonic nanoparticle enhanced photocurrent in GaN/InGaN/GaN quantum well solar cells Imogen M of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA 2 Semiconductor Nanoscience Institute, California Institute of Technology, Pasadena, California 91125, USA Received 26

Atwater, Harry

176

GaAsbased quantum cascade lasers  

Science Journals Connector (OSTI)

...N. Murdin GaAs-based quantum cascade lasers Sirtori H. Page C. Becker...state-of-the-art of GaAs-based quantum cascade lasers. These new light sources...2000.0739 GaAs-based quantum cascade lasers By C. Sirtori, H. Page...

2001-01-01T23:59:59.000Z

177

CfA4: LIGHT CURVES FOR 94 TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

We present multi-band optical photometry of 94 spectroscopically confirmed Type Ia supernovae (SNe Ia) in the redshift range 0.0055-0.073, obtained between 2006 and 2011. There are a total of 5522 light-curve points. We show that our natural-system SN photometry has a precision of {approx}< 0.03 mag in BVr'i', {approx}< 0.06 mag in u', and {approx}< 0.07 mag in U for points brighter than 17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010, 0.012, 0.014, 0.046, and 0.073 mag in BVr'i'u'U, respectively. Comparisons of our standard-system photometry with published SN Ia light curves and comparison stars reveal mean agreement across samples in the range of {approx}0.00-0.03 mag. We discuss the recent measurements of our telescope-plus-detector throughput by direct monochromatic illumination by Cramer et al. This technique measures the whole optical path through the telescope, auxiliary optics, filters, and detector under the same conditions used to make SN measurements. Extremely well characterized natural-system passbands (both in wavelength and over time) are crucial for the next generation of SN Ia photometry to reach the 0.01 mag accuracy level. The current sample of low-z SNe Ia is now sufficiently large to remove most of the statistical sampling error from the dark-energy error budget. But pursuing the dark-energy systematic errors by determining highly accurate detector passbands, combining optical and near-infrared (NIR) photometry and spectra, using the nearby sample to illuminate the population properties of SNe Ia, and measuring the local departures from the Hubble flow will benefit from larger, carefully measured nearby samples.

Hicken, Malcolm; Challis, Peter; Kirshner, Robert P.; Bakos, Gaspar; Berlind, Perry; Brown, Warren R.; Caldwell, Nelson; Calkins, Mike; Falco, Emilio; Fernandez, Jose; Friedman, Andrew S.; Groner, Ted; Hartman, Joel [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Rest, Armin [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Cramer, Claire E. [NIST (National Institute of Standards and Technology), Gaithersburg, MD 20899 (United States); Wood-Vasey, W. Michael [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Currie, Thayne [NASA, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); De Kleer, Kathy [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Esquerdo, Gil; Everett, Mark, E-mail: mhicken@cfa.harvard.edu [Planetary Science Institute, 1700 East Fort Lowell Road, Tucson, AZ 85719 (United States); and others

2012-06-01T23:59:59.000Z

178

Effect of buffer structures on AlGaN/GaN high electron mobility transistor reliability  

SciTech Connect (OSTI)

AlGaN/GaN high electron mobility transistors (HEMTs) with three different types of buffer layers, including a GaN/AlGaN composite layer, or 1 or 2 lm GaN thick layers, were fabricated and their reliability compared. The HEMTs with the thick GaN buffer layer showed the lowest critical voltage (Vcri) during off-state drain step-stress, but this was increased by around 50% and 100% for devices with the composite AlGaN/GaN buffer layers or thinner GaN buffers, respectively. The Voff - state for HEMTs with thin GaN and composite buffers were 100 V, however, this degraded to 50 60V for devices with thick GaN buffers due to the difference in peak electric field near the gate edge. A similar trend was observed in the isolation breakdown voltage measurements, with the highest Viso achieved based on thin GaN or composite buffer designs (600 700 V), while a much smaller Viso of 200V was measured on HEMTs with the thick GaN buffer layers. These results demonstrate the strong influence of buffer structure and defect density on AlGaN/GaN HEMT performance and reliability.

Liu, L. [University of Florida, Gainesville; Xi, Y. Y. [University of Florida, Gainesville; Ren, F. [University of Florida; Pearton, S. J. [University of Florida; Laboutin, O. [Kopin Corporation, Taunton, MA; Cao, Yu [Kopin Corporation, Taunton, MA; Johnson, Wayne J. [Kopin Corporation, Taunton, MA; Kravchenko, Ivan I [ORNL

2012-01-01T23:59:59.000Z

179

IAS15: a fast, adaptive, high-order integrator for gravitational dynamics, accurate to machine precision over a billion orbits  

Science Journals Connector (OSTI)

......error behaves like a random walk. Our tests show that ias15 is superior to a mixed-variable...that ias15 follows Brouwer's law. We test our integrator in a wide variety of cases...focus on the two-body problem, a simple test case where we know the correct answer......

Hanno Rein; David S. Spiegel

2015-01-01T23:59:59.000Z

180

Coulomb excitation of 73Ga  

E-Print Network [OSTI]

The B(E2; Ii -> If) values for transitions in 71Ga and 73Ga were deduced from a Coulomb excitation experiment at the safe energy of 2.95 MeV/nucleon using post-accelerated beams of 71,73Ga at the REX-ISOLDE on-line isotope mass separator facility. The emitted gamma rays were detected by the MINIBALL-detector array and B(E2; Ii->If) values were obtained from the yields normalized to the known strength of the 2+ -> 0+ transition in the 120Sn target. The comparison of these new results with the data of less neutron-rich gallium isotopes shows a shift of the E2 collectivity towards lower excitation energy when adding neutrons beyond N = 40. This supports conclusions from previous studies of the gallium isotopes which indicated a structural change in this isotopical chain between N = 40 and N = 42. Combined with recent measurements from collinear laser spectroscopy showing a 1/2- spin and parity for the ground state, the extracted results revealed evidence for a 1/2-; 3/2- doublet near the ground state in 73 31Ga42 differing by at most 0.8 keV in energy.

J. Diriken; I. Stefanescu; D. Balabanski; N. Blasi; A. Blazhev; N. Bree; J. Cederkll; T. E. Cocolios; T. Davinson; J. Eberth; A. Ekstrm; D. V. Fedorov; V. N. Fedosseev; L. M. Fraile; S. Franchoo; G. Georgiev; K. Gladnishki; M. Huyse; O. V. Ivanov; V. S. Ivanov; J. Iwanicki; J. Jolie; T. Konstantinopoulos; Th. Krll; R. Krcken; U. Kster; A. Lagoyannis; G. Lo Bianco; P. Maierbeck; B. A. Marsh; P. Napiorkowski; N. Patronis; D. Pauwels; P. Reiter; M. Seliverstov; G. Sletten; J. Van de Walle; P. Van Duppen; D. Voulot; W. B. Walters; N. Warr; F. Wenander; K. Wrzosek

2010-10-13T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Charakterisierung und Prparation von GaN und Herstellung von In-Plane-Gate Transistoren in AlxGa1-xN/GaN Heterostrukturen.  

E-Print Network [OSTI]

??Gegenstand der Arbeit sind GaN-Volumenmaterial und AlxGa1-xN/GaN HEMTs (high electron mobility transistor), welche ein zweidimensionales Elektronengas (2DEG) besitzen. Die Materialien wurden durch elektrische Messungen, insbesondere (more)

Ebbers, Andr

2003-01-01T23:59:59.000Z

182

FROM RACKS TO POINTED HOPF ALGEBRAS AS ANDRUSKIEWITSCH AND MAT IAS GRA ~  

E-Print Network [OSTI]

FROM RACKS TO POINTED HOPF ALGEBRAS NICOL #19; AS ANDRUSKIEWITSCH AND MAT #19; IAS GRA ~ NA (C X; c q ), where X is a rack and q is a 2-cocycle on X with values in C #2; . Racks and cohomology of racks appeared also in the work of topologists. This leads us to the study of the structure of racks

Graña, Matías

183

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame  

E-Print Network [OSTI]

Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame S. E of these regions can be supersonic and could initiate a detonation. Subject headings: supernovae: general a late time transition of the thermonuclear burning to a detonation wave (e.g., Hoflich et al. 1995

184

Section I. Summary of Project Activities Section I-A. 2008-2009 Project Summary  

E-Print Network [OSTI]

Section I. Summary of Project Activities Section I-A. 2008-2009 Project Summary University year, we accomplished the following: · Established a dual career opportunity procedure vetted to address, communicate procedures for the new daycare facility, and to explore the potential

Farritor, Shane

185

SEASONAL V A R IA TIONS IN STRUCTURE AND CIRCULATION IN THE RED SEA  

E-Print Network [OSTI]

SEASONAL V A R IA TIONS IN STRUCTURE AND CIRCULATION IN THE RED SEA A DISSERTATION SUBMITTE D and surface circulation in the Red Sea, occur r ing along the north-south axis of the Sea and extending fr om on in the northern Red Sea is frorn the nor th-northwest throughout the year' during the winter ( fr om October

Luther, Douglas S.

186

Seminar Ia, cetrti letnik, stari program LONGITUDINAL DYNAMICS OF PARTICLES IN ACCELERATORS  

E-Print Network [OSTI]

Seminar Ia, cetrti letnik, stari program LONGITUDINAL DYNAMICS OF PARTICLES IN ACCELERATORS Author motion of charged particles in particle accelerators. The technique of acceleration by electromagnetic waves is explored and the stability of motion under such acceleration is inspected. The seminar

?umer, Slobodan

187

Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae  

SciTech Connect (OSTI)

The final technical report from the project "Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae" led at Rutgers the State University of New Jersey by Prof. Saurabh W. Jha is presented, including all publications resulting from this award.

Saurabh W. Jha

2012-10-03T23:59:59.000Z

188

SponSored by http://www.ntu.edu.sg/ias/oCpA8  

E-Print Network [OSTI]

SponSored by http://www.ntu.edu.sg/ias/oCpA8 International Conference on physics education · Statistical and Nonlinear physics · Science Education · Women in Physics Sir Michael PEPPER Univ. College or poster presentations. All posters at the conference will be considered for the 2014 OCPA-APS Outstanding

Faraon, Andrei

189

THE CARNEGIE SUPERNOVA PROJECT: SECOND PHOTOMETRY DATA RELEASE OF LOW-REDSHIFT TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

The Carnegie Supernova Project (CSP) was a five-year observational survey conducted at Las Campanas Observatory that obtained, among other things, high-quality light curves of {approx}100 low-redshift Type Ia supernovae (SNe Ia). Presented here is the second data release of nearby SN Ia photometry consisting of 50 objects, with a subset of 45 having near-infrared follow-up observations. Thirty-three objects have optical pre-maximum coverage with a subset of 15 beginning at least five days before maximum light. In the near-infrared, 27 objects have coverage beginning before the epoch of B-band maximum, with a subset of 13 beginning at least five days before maximum. In addition, we present results of a photometric calibration program to measure the CSP optical (uBgVri) bandpasses with an accuracy of {approx}1%. Finally, we report the discovery of a second SN Ia, SN 2006ot, similar in its characteristics to the peculiar SN 2006bt.

Stritzinger, Maximilian D. [The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm (Sweden); Phillips, M. M.; Campillay, Abdo; Morrell, Nidia; Krzeminski, Wojtek; Roth, Miguel [Carnegie Observatories, Las Campanas Observatory, La Serena (Chile); Boldt, Luis N. [Argelander Institut fuer Astronomie, Universitaet Bonn, D-53111 Bonn (Germany); Burns, Chris; Freedman, Wendy L.; Madore, Barry F.; Persson, Sven E. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Contreras, Carlos [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Victoria 3122 (Australia); Gonzalez, Sergio [Atacama Large Millimeter/Submillimeter Array, European Southern Observatory (Chile); Folatelli, Gaston [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Salgado, Francisco [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); DePoy, D. L.; Marshall, J. L.; Rheault, Jean-Philippe; Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Hamuy, Mario, E-mail: max.stritzinger@astro.su.se, E-mail: max@dark-cosmology.dk, E-mail: mstritzinger@lco.cl [Departamento de Astronomia, Universidad de Chile, Santiago (Chile)

2011-11-15T23:59:59.000Z

190

Abstract IA08: PTEN and PI3K signaling in brain development and disease  

Science Journals Connector (OSTI)

...Abstract IA08: PTEN and PI3K signaling in brain development and disease Suzanne J. Baker...an increased genetic susceptibility to brain tumors. However, inherited mutation of...and tumor suppression in the mammalian brain. Recently, germline or somatic mutations...

Suzanne J. Baker

2014-12-01T23:59:59.000Z

191

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1  

E-Print Network [OSTI]

Turbulent Oxygen Flames in Type Ia Supernovae A. J. Aspden1 , J. B. Bell1 , and S. E. Woosley2 oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen

192

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n  

E-Print Network [OSTI]

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n , P.V. Leksin s t r a c t A review of our recent results on the spin valve effect is presented. We have used coefficient DF and the exchange splitting I of the conduction band in the F layer [1]. For pure Fe the value

Fominov, Yakov

193

Magnetism and transport properties of epitaxial Fe-Ga thin films on GaAs(001)  

SciTech Connect (OSTI)

Epitaxial Fe-Ga thin films in disordered bcc {alpha}-Fe crystal structure (A2) have been grown on GaAs(001) by molecular beam epitaxy. The saturated magnetization (M{sub S}) decreased from 1371 to 1105 kA/m with increasing Ga concentration from 10.5 to 24.3 % at room temperature. The lattice parameter increased with the increase in Ga content because of the larger atomic radius of Ga atom than that of Fe. The increase in carrier density with Ga content caused in lower resistivity.

Duong Anh Tuan; Shin, Yooleemi; Cho, Sunglae [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Dang Duc Dung [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet road, Ha Noi (Viet Nam); Vo Thanh Son [Centers for Nanobioenineering and Spintronics, Chungnam National University, Daejon 350-746 (Korea, Republic of)

2012-04-01T23:59:59.000Z

194

CIMAT, VIII Escuela de verano, 30 de julio -12 de ago* Introducci'on a la Geometr'ia de la Mec'ani*  

E-Print Network [OSTI]

con un valor fijo de la energ* *'ia corresponden a secciones del cono del inciso (a) por * *energ'ia tienen el mismo semi-eje mayor. 11.Demuestra la tercera ley de Kepler: toda soluci'on peri Introducci'on a la Geometr'ia de la Mec'ani* *ca Cl'asica Problemas 7 - 12

Bor, Gil

195

Quantification of the Heterogeneity in Breast Cancer Cell Lines Using Whole-Cell Impedance Spectroscopy  

Science Journals Connector (OSTI)

...School of Electrical and Computer Engineering, Georgia...Department of Electrical and Computer Engineering, Texas...Atlanta, GA; and 3 School of Electrical and Computer Engineering, Georgia...Technology, Atlanta, GA Grant support: NIH/National...

Arum Han; Lily Yang; and A. Bruno Frazier

2007-01-01T23:59:59.000Z

196

Composition dependence of interband transition intensities in GaPN, GaAsN, and GaPAs alloys  

Science Journals Connector (OSTI)

Using large (512-atom) pseudopotential supercell calculations, we have investigated the composition dependence of the momentum matrix element Mv,c for transitions between the valence-band maximum and the conduction-band minimum of three semiconductor alloys:?GaP1-xNx and GaAs1-xNx, exhibiting large chemical and size differences between their alloyed elements, and GaP1-xAsx, which is a weakly perturbed alloy. In the composition ranges where these alloys have a direct band gap, we find that (i) in GaP1-xAsx, Mv,c is large (like the virtual-crystal value) and nearly composition independent; (ii) in GaAs1-xNx, Mv,c is strongly composition dependent: large for small x and small for large x; and (iii) in GaP1-xNx, Mv,c is only slightly composition dependent and is significantly reduced relative to the virtual-crystal value. The different behavior of GaP1-xAsx, GaP1-xNx, and GaAs1-xNx is traced to the existence/absence of impurity levels at the dilute alloy limits: (a) there are no gap-level impurity states at the x?1 or x?0 limits of GaP1-xAsx, (b) an isolated As impurity in GaN (GaN?:As) has a deep band gap impurity level but no deep impurity state is found for N in GaAs, and (c) GaN?:P exhibits a P-localized deep band-gap impurity state and GaP?:N has an N-localized resonant state. The existence of deep levels leads to wave-function localization in real space, thus to a spectral spread in momentum space and to a reduction of Mv,c. These impurity levels are facilitated by atomic relaxations, as evident by the fact that unrelaxed GaN?:As and GaN?:P, show no deep levels, have extended wave functions, and have large interband transition elements.

L. Bellaiche; Su-Huai Wei; Alex Zunger

1997-10-15T23:59:59.000Z

197

November 9, 2011 Planned Development Amendment  

E-Print Network [OSTI]

105 Tempe, AZ 85281 Cleanroom, HP Imaging, HPM HOK 191 Peachtree St. Suite 4100 Atlanta, GA 30303 Lab

Pritchard, Jonathan

198

Accepted with minor revisions by TNNLS Special Issue on Learning in Nonstationary and Evolving Environments  

E-Print Network [OSTI]

of Technology, Atlanta, GA 30332­0250 2Entergy Services, Inc., New Orleans, LA 70053 3Howard University, NW

Ji, Chuanyi

199

The Red-Cockaded Woodpecker: A Selectively Annotated Bibliography  

E-Print Network [OSTI]

species act. In TAPPI Proceedings of International1085-1092). Atlanta, GA: TAPPI Press. Provides a detailed

Wishard, Lisa

1998-01-01T23:59:59.000Z

200

Choice Based Revenue Management for Parallel Flights  

E-Print Network [OSTI]

Mar 6, 2014 ... We formulate corresponding deterministic (fluid) optimization ... and Systems Engineering, Georgia Institute of Technology, Atlanta, GA...

Jim Dai

2014-03-06T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Ultra-Thin, Triple-Bandgap GaInP/GaAs/GaInAs Monolithic Tandem Solar Cells  

SciTech Connect (OSTI)

The performance of state-of-the-art, series-connected, lattice-matched (LM), triple-junction (TJ), III-V tandem solar cells could be improved substantially (10-12%) by replacing the Ge bottom subcell with a subcell having a bandgap of {approx}1 eV. For the last several years, research has been conducted by a number of organizations to develop {approx}1-eV, LM GaInAsN to provide such a subcell, but, so far, the approach has proven unsuccessful. Thus, the need for a high-performance, monolithically integrable, 1-eV subcell for TJ tandems has remained. In this paper, we present a new TJ tandem cell design that addresses the above-mentioned problem. Our approach involves inverted epitaxial growth to allow the monolithic integration of a lattice-mismatched (LMM) {approx}1-eV GaInAs/GaInP double-heterostructure (DH) bottom subcell with LM GaAs (middle) and GaInP (top) upper subcells. A transparent GaInP compositionally graded layer facilitates the integration of the LM and LMM components. Handle-mounted, ultra-thin device fabrication is a natural consequence of the inverted-structure approach, which results in a number of advantages, including robustness, potential low cost, improved thermal management, incorporation of back-surface reflectors, and possible reclamation/reuse of the parent crystalline substrate for further cost reduction. Our initial work has concerned GaInP/GaAs/GaInAs tandem cells grown on GaAs substrates. In this case, the 1-eV GaInAs experiences 2.2% compressive LMM with respect to the substrate. Specially designed GaInP graded layers are used to produce 1-eV subcells with performance parameters nearly equaling those of LM devices with the same bandgap (e.g., LM, 1-eV GaInAsP grown on InP). Previously, we reported preliminary ultra-thin tandem devices (0.237 cm{sup 2}) with NREL-confirmed efficiencies of 31.3% (global spectrum, one sun) (1), 29.7% (AM0 spectrum, one sun) (2), and 37.9% (low-AOD direct spectrum, 10.1 suns) (3), all at 25 C. Here, we include recent results of testing similar devices under the concentrated AMO spectrum, and also present the first demonstration of a high-efficiency, ultra-thin GaInP/GaAs/GaInAs tandem cell processed on a flexible kapton handle.

Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

2007-02-01T23:59:59.000Z

202

Princeton Plasma Physics Lab - General Atomics (GA)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

general-atomics-ga General general-atomics-ga General Atomics en The Scorpion's Strategy: "Catch and Subdue" http://www.pppl.gov/node/1132

American Fusion News Category: 
ga">General Atomics (GA)
203

Preview of AAAS Meeting, Atlanta  

Science Journals Connector (OSTI)

...Science Teachers Association. Arranged by Katherine Hertzka, Hoke Smith High School and...Bradford D. Ansley, Edwina Davis, and Katherine Barnwell. Roland H. Berg will preside...of Business-Administration. George Wheeler, Oglethorpe Univer-sity. Committee...

Raymond L. Taylor

1955-12-02T23:59:59.000Z

204

Preview of AAAS Meeting, Atlanta  

Science Journals Connector (OSTI)

...Laboratories; Clyde L. 'Cowan, Jr., Los Alamos Scien-tific Laboratory; Arthur E...Pharmaceuti-cals. Color; 15 min. The Suspension Bridge. U.S. Steel Corp. Color...Dal-las, and San Francisco; 9,300 employees are engaged in the annual production...

Raymond L. Taylor

1955-12-02T23:59:59.000Z

205

IA REP0 SAND85-2809 Unlimited Release UC-92A  

Office of Scientific and Technical Information (OSTI)

IA REP0 SAND85-2809 Unlimited Release UC-92A IA REP0 SAND85-2809 Unlimited Release UC-92A Printed July 1986 High Energy Gas Fracture Experiments in Fluid-Filled Boreholes-Potential Geothermal Application J. F. Cuderman, T. Y. Chu, J. Jung, R. D. Jacobson Prepared by Sandia National Laboratories Albuquerque, New Mexico 87 185 and Livermore, California 94550 for the United States Department of Energy under Contract DE-AC04-76DP00789 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process

206

File:USDA-CE-Production-GIFmaps-IA.pdf | Open Energy Information  

Open Energy Info (EERE)

IA.pdf IA.pdf Jump to: navigation, search File File history File usage Iowa Ethanol Plant Locations Size of this preview: 776 × 600 pixels. Full resolution ‎(1,650 × 1,275 pixels, file size: 303 KB, MIME type: application/pdf) Description Iowa Ethanol Plant Locations Sources United States Department of Agriculture Related Technologies Biomass, Biofuels, Ethanol Creation Date 2010-01-19 Extent State Countries United States UN Region Northern America States Iowa External links http://www.nass.usda.gov/Charts_and_Maps/Ethanol_Plants/ File history Click on a date/time to view the file as it appeared at that time. Date/Time Thumbnail Dimensions User Comment current 16:13, 27 December 2010 Thumbnail for version as of 16:13, 27 December 2010 1,650 × 1,275 (303 KB) MapBot (Talk | contribs) Automated bot upload

207

Mechanistic studies of proton-coupled electron transfer in aminotyrosine- and fluorotyrosine- substituted class Ia Ribonucleotide reductase  

E-Print Network [OSTI]

Ribonucleotide reductase (RNR) catalyzes the conversion of nucleotides to 2'- deoxynucleotides in all organisms. The class Ia RNR from Escherichia coli is active as an a2p2 complex and utilizes an unprecedented mechanism ...

Minnihan, Ellen Catherine

2012-01-01T23:59:59.000Z

208

Generation of a stable, aminotyrosyl radical-induced ?2?2 complex of Escherichia coli class Ia ribonucleotide reductase  

E-Print Network [OSTI]

Ribonucleotide reductase (RNR) catalyzes the conversion of nucleoside diphosphates to deoxynucleoside diphosphates (dNDPs). The Escherichia coli class Ia RNR uses a mechanism of radical propagation by which a cysteine in ...

Minnihan, Ellen Catherine

209

IA --"-IScience Service Featuse 'I WHY T i E IJEAYIiER ?  

E-Print Network [OSTI]

No. 591 April 3 IA --"-IScience Service Featuse 'I WHY T i E IJEAYIiER ? II city located oa the Ice.pp';g a% Bidialo, The ice c h i l l s a t h i n laye:. of a i r aver the Sake aridto laewwd. NOW$ vhen r may be srrfficionl t o produce a sheet cloud and g i ~ eBuffalo a day not oalg dwnt arid chilly Lu

210

Especialista Universitario Java Enterprise 2010-2011 Depto. Ciencia de la Computacin e IA  

E-Print Network [OSTI]

Especialista Universitario Java Enterprise © 2010-2011 Depto. Ciencia de la Computación e IA Sesión 1: Introducción a JMS #12;Servicios de Mensajes con JMS © 2010-2011 Depto. Ciencia de la Computación · Una Aplicación JMS · PTP · Pub/Sub #12;Servicios de Mensajes con JMS © 2010-2011 Depto. Ciencia de la

Escolano, Francisco

211

On the Thermonuclear Runaway in Type Ia Supernovae: How to Run Away?  

Science Journals Connector (OSTI)

Type Ia supernovae (SNe Ia) are thought to be thermonuclear explosions of massive white dwarfs (WDs). We present the first study of multidimensional effects during the final hours prior to the thermonuclear runaway that leads to the explosion. The calculations utilize an implicit, two-dimensional hydrodynamic code. Mixing and the ignition process are studied in detail. We find that the initial chemical structure of the WD is changed, but the material is not fully homogenized. In particular, the exploding WD sustains a central region with a low C/O ratio. This implies that the explosive nuclear burning will begin in a partially carbon-depleted environment. The thermonuclear runaway happens in a well-defined region close to the center. It is induced by compressional heat when matter is brought inward by convective flows. We find no evidence for multiple spot or strong off-center ignition. Convective velocities in the WD are on the order of 100 km s-1, which is well above the effective burning speeds in SNe Ia previously expected right after the runaway. In our calculations, the ignition occurs near the center. Then, for ? 0.5-1 s, the speed of the burning front will neither be determined by the laminar speed nor the Rayleigh-Taylor instabilities but by convective flows produced prior to the runaway. The consequences are discussed for our understanding of the detailed physics of the flame propagation, the deflagration to detonation transition, and the nucleosynthesis in the central layers. Our results strongly suggest the preconditioning of the progenitor as a key factor for our understanding of the diversity in SNe Ia.

P. Hflich; J. Stein

2002-01-01T23:59:59.000Z

212

GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators  

SciTech Connect (OSTI)

We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

2005-08-01T23:59:59.000Z

213

Testing the DistanceDuality Relation with Galaxy Clusters and Type Ia Supernovae  

Science Journals Connector (OSTI)

In this Letter, we propose a new and model-independent cosmological test for the distance-duality (DD) relation, ? = DL (z)(1 + z)2/DA (z) = 1, where DL and DA are, respectively, the luminosity and angular diameter distances. For DL we consider two sub-samples of Type Ia supernovae (SNe Ia) taken from Constitution data whereas DA distances are provided by two samples of galaxy clusters compiled by De Filippis etal. and Bonamente etal. by combining Sunyaev-Zeldovich effect and X-ray surface brightness. The SNe Ia redshifts of each sub-sample were carefully chosen to coincide with the ones of the associated galaxy cluster sample (?z DA (z) ? DL (z), we have tested the DD relation by assuming that ? is a function of the redshift parameterized by two different expressions: ?(z) = 1 + ?0 z and ?(z) = 1 + ?0 z/(1 + z), where ?0 is a constant parameter quantifying a possible departure from the strict validity of the reciprocity relation (?0 = 0). In the best scenario (linear parameterization), we obtain ?0 = 0.28+0.44 0.44 (2?, statistical + systematic errors) for the De Filippis etal. sample (elliptical geometry), a result only marginally compatible with the DD relation. However, for the Bonamente etal. sample (spherical geometry) the constraint is ?0 = 0.42+0.34 0.34 (3?, statistical + systematic errors), which is clearly incompatible with the duality-distance relation.

R. F. L. Holanda; J. A. S. Lima; M. B. Ribeiro

2010-01-01T23:59:59.000Z

214

Evaluation of copper for divider subassembly in MCO Mark IA and Mark IV scrap fuel baskets  

SciTech Connect (OSTI)

The K Basin Spent Nuclear Fuel (SNF) Project Multi-Canister Overpack (MCO) subprojection eludes the design and fabrication of a canister that will be used to confine, contain, and maintain fuel in a critically safe array to enable its removal from the K Basins, vacuum drying, transport, staging, hot conditioning, and interim storage (Goldinann 1997). Each MCO consists of a shell, shield plug, fuel baskets (Mark IA or Mark IV), and other incidental equipment. The Mark IA intact and scrap fuel baskets are a safety class item for criticality control and components necessary for criticality control will be constructed from 304L stainless steel. It is proposed that a copper divider subassembly be used in both Mark IA and Mark IV scrap baskets to increase the safety basis margin during cold vacuum drying. The use of copper would increase the heat conducted away from hot areas in the baskets out to the wall of the MCO by both radiative and conductive heat transfer means. Thus copper subassembly will likely be a safety significant component of the scrap fuel baskets. This report examines the structural, cost and corrosion consequences associated with using a copper subassembly in the stainless steel MCO scrap fuel baskets.

Graves, C.E.

1997-09-29T23:59:59.000Z

215

Observational constraints from SNe Ia and Gamma-Ray Bursts on a clumpy universe  

E-Print Network [OSTI]

The luminosity distance describing the effect of local inhomogeneities in the propagation of light proposed by Zeldovich-Kantowski-Dyer-Roeder (ZKDR) is tested with two probes for two distinct ranges of redshifts: supernovae Ia (SNe Ia) in 0.015 gamma-ray bursts (GRBs) in 1.547 < z < 3.57. Our analysis is performed by a Markov Chain Monte Carlo (MCMC) code that allows us to constrain the matter density parameter \\Omega_m as well as the smoothness parameter $\\alpha$ that measures the inhomogeneous-homogeneous rate of the cosmic fluid in a flat \\LambdaCDM model. The obtained best fits are (\\Omega_m=0.285^{+0.019}_{-0.018}, \\alpha= 0.856^{+0.106}_{-0.176}) from SNe Ia and (\\Omega_m=0.259^{+0.028}_{-0.028}, \\alpha=0.587^{+0.201}_{-0.202}) from GRBs, while from the joint analysis the best fits are (\\Omega_m=0.284^{+0.021}_{-0.020}, \\alpha= 0.685^{+0.164}_{-0.171}) with a \\chi^2_{\\rm red}=0.975. The value of the smoothness parameter $\\alpha$ indicates a clumped universe however it does not have an impact on the amount of dark energy (cosmological constant) needed to fit observations. This result may be an indication that the Dyer-Roeder approximation does not describe in a precise form the effects of clumpiness in the expansion of the universe.

Nora Bretn; Ariadna Montiel

2013-03-06T23:59:59.000Z

216

Especialista Universitario Java Enterprise Componentes de presentacin 2012-2013 Depto. Ciencia de la Computacin e IA Sesin 4  

E-Print Network [OSTI]

Especialista Universitario Java Enterprise Componentes de presentación © 2012-2013 Depto. Ciencia presentación © 2012-2013 Depto. Ciencia de la Computación e IA Sesión 4 Experto Universitario Java Enterprise Componentes de presentación © 2012-2013 Depto. Ciencia de la Computación e IA Sesión 4 Experto Universitario

Escolano, Francisco

217

Experto Universitario Java Enterprise Componentes de presentacin 2012-2013 Depto. Ciencia de la Computacin e IA Sesin 1  

E-Print Network [OSTI]

Experto Universitario Java Enterprise Componentes de presentación © 2012-2013 Depto. Ciencia de la Universitario Java Enterprise Componentes de presentación © 2012-2013 Depto. Ciencia de la Computación e IA Componentes de presentación © 2012-2013 Depto. Ciencia de la Computación e IA Sesión 1 Experto Universitario

Escolano, Francisco

218

Structural and optical properties of InGaNGaN nanowire heterostructures grown by molecular beam epitaxy  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaN to higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, ?-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applications in optoelectronics and photovoltaics.

Limbach, F. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jlich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Gotschke, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jlich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Stoica, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jlich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Calarco, R. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jlich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Sutter, E. [Brookhaven National Lab., Upton, NY (United States); Ciston, J. [Brookhaven National Lab., Upton, NY (United States); Cusco, R. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Artus, L. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Kremling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Hofling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Worschech, L. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Grutzmacher, D. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jlich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)

2011-01-07T23:59:59.000Z

219

Violet to deep-ultraviolet InGaN/GaN and GaN/AlGaN quantum structures for UV electroabsorption modulators  

E-Print Network [OSTI]

focused on the demonstration of ultraviolet UV optoelectronic devices. Such devices hold promise, material related problems complicate the growth of such optoelectronic devices oper- ating at short wavelengths. With the use of InGaN/GaN quantum structures, optoelectronic devices operating in vis- ible

Demir, Hilmi Volkan

220

Utilizing Type Ia Supernovae in a Large, Fast, Imaging Survey to Constrain Dark Energy  

Science Journals Connector (OSTI)

We study the utility of a large sample of Type Ia supernovae (SNe Ia) that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider both the information contained in the traditional luminosity distance test as well as the spread in Ia SN fluxes at fixed redshift induced by gravitational lensing. As would be required from an imaging survey, we include a treatment of photometric redshift uncertainties in our analysis. Our primary result is that the information contained in the mean distance moduli of SNe Ia and the dispersion of SN Ia distance moduli complement each other, breaking a degeneracy between the present dark energy equation of state and its time variation without the need for a high-redshift (z 0.8) SN sample. Including lensing information also allows for some internal calibration of photometric redshifts. To address photometric redshift uncertainties, we present dark energy constraints as a function of the size of an external set of spectroscopically observed SNe that may be used for redshift calibration, N spec. Depending upon the details of potentially available, external SN data sets, we find that an imaging survey can constrain the dark energy equation of state at the epoch where it is best constrained w p, with a 1? error of ?(w p) ? 0.03-0.09. In addition, the marginal improvement in the error ?(w p) from an increase in the spectroscopic calibration sample drops once N spec ~ a few ? 103. This result is important because it is of the order of the size of calibration samples likely to be compiled in the coming decade and because, for samples of this size, the spectroscopic and imaging surveys individually place comparable constraints on the dark energy equation of state. In all cases, it is best to calibrate photometric redshifts with a set of spectroscopically observed SNe with relatively more objects at high redshift (z 0.5) than the parent sample of imaging SNe.

Andrew R. Zentner; Suman Bhattacharya

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

US SoAtl GA Site Consumption  

Gasoline and Diesel Fuel Update (EIA)

GA GA Site Consumption million Btu $0 $500 $1,000 $1,500 $2,000 $2,500 US SoAtl GA Expenditures dollars ALL ENERGY average per household (excl. transportation) 0 4,000 8,000 12,000 16,000 US SoAtl GA Site Consumption kilowatthours $0 $300 $600 $900 $1,200 $1,500 $1,800 US SoAtl GA Expenditures dollars ELECTRICITY ONLY average per household * Site energy consumption (89.5 million Btu) and energy expenditures per household ($2,067) in Georgia are similar to the U.S. household averages. * Per household electricity consumption in Georgia is among the highest in the country, but similar to other states in the South. * Forty-five percent of homes in Georgia were built since 1990, a characteristic typically associated with lower per household consumption. Georgia homes,

222

US SoAtl GA Site Consumption  

U.S. Energy Information Administration (EIA) Indexed Site

GA GA Site Consumption million Btu $0 $500 $1,000 $1,500 $2,000 $2,500 US SoAtl GA Expenditures dollars ALL ENERGY average per household (excl. transportation) 0 4,000 8,000 12,000 16,000 US SoAtl GA Site Consumption kilowatthours $0 $300 $600 $900 $1,200 $1,500 $1,800 US SoAtl GA Expenditures dollars ELECTRICITY ONLY average per household * Site energy consumption (89.5 million Btu) and energy expenditures per household ($2,067) in Georgia are similar to the U.S. household averages. * Per household electricity consumption in Georgia is among the highest in the country, but similar to other states in the South. * Forty-five percent of homes in Georgia were built since 1990, a characteristic typically associated with lower per household consumption. Georgia homes,

223

Electron Transport in a Two-Dimensional Electron Gas at GaAs/AlGaAs Heterointerface  

E-Print Network [OSTI]

in condensed matters. Two-dimensional electron gas (2DEG) at the GaAs/AlGaAs hetero-interface o ersThesis Electron Transport in a Two-Dimensional Electron Gas at GaAs/AlGaAs Heterointerface under of the art samples, the mean free path of electrons exceeds 10;4 m at low temperature. The achievement

Katsumoto, Shingo

224

CIMAT, VI Escuela de verano, 25 de julio 7 de agosto 1999 Introducci'on a la Geometr'ia de la Mec'anica Cl'asica  

E-Print Network [OSTI]

parametrizada por (x(t); ?? x(t)): (d) Dibujar las gr'aficas de su energ'ia cin'etica T = ( ?? x) 2 =2 y potencial­ vaci'on de energ'ia, E = T + V = constante: (e) Repetir los 4 incisos anteriores con x(1) = 2; ?? x(0CIMAT, VI Escuela de verano, 25 de julio ­ 7 de agosto 1999 Introducci'on a la Geometr'ia de la Mec

Bor, Gil

225

CIMAT, VI Escuela de verano, 25 de julio -7 de agosto 1999 Introducci'on a la Geometr'ia de la Mec'anica Cl'asica  

E-Print Network [OSTI]

(t), `x(t)). (d)Dibujar las gr'aficas de su energ'ia cin'etica T = (x`)2=2 y potencial* * V = x2- vaci'on de energ'ia, E = T + V = constante. (e)Repetir los 4 incisos anteriores con x(1) = 2, `x CIMAT, VI Escuela de verano, 25 de julio - 7 de agosto 1999 Introducci'on a la Geometr'ia de la

Bor, Gil

226

Synthesis, morphology and optical properties of GaN and AlGaN semiconductor nanostructures  

SciTech Connect (OSTI)

Hexagonal Gallium Nitride (GaN) and Aluminum Gallium Nitride (AlGaN) nanoparticles were synthesized by sol-gel method using Ethylene Diamine Tetra Acetic acid (EDTA) complex route. Powder X-ray diffraction (PXRD) analysis confirms the hexagonal wurtzite structure of GaN and Al{sub 0.25}Ga{sub 0.75}N nanoparticles. Surface morphology and elemental analysis were carried out by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX). The room temperature Photoluminescence (PL) study shows the near band edge emission for GaN at 3.35 eV and at 3.59 eV for AlGaN nanoparticles. The Aluminum (Al) composition of 20% has been obtained from PL emission around 345 nm.

Kuppulingam, B., E-mail: drbaskar2009@gmail.com; Singh, Shubra, E-mail: drbaskar2009@gmail.com; Baskar, K., E-mail: drbaskar2009@gmail.com [Crystal Growth Centre, Anna University, Chennai-600025 (India)

2014-04-24T23:59:59.000Z

227

Multi-bands photoconductive response in AlGaN/GaN multiple quantum wells  

SciTech Connect (OSTI)

Based on the optical transitions among the quantum-confined electronic states in the conduction band, we have fabricated multi-bands AlGaN/GaN quantum well infrared photodetectors. Crack-free AlGaN/GaN multiple quantum wells (MQWs) with atomically sharp interfaces have been achieved by inserting an AlN interlayer, which releases most of the tensile strain in the MQWs grown on the GaN underlayer. With significant reduction of dark current by using thick AlGaN barriers, photoconductive responses are demonstrated due to intersubband transition in multiple regions with center wavelengths of 1.3, 2.3, and 4??m, which shows potential applications on near infrared detection.

Chen, G.; Rong, X.; Xu, F. J.; Tang, N. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Wang, X. Q., E-mail: wangshi@pku.edu.cn; Shen, B., E-mail: bshen@pku.edu.cn [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Fu, K.; Zhang, B. S. [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Ruoshui Road 398, 215123 Suzhou (China); Hashimoto, H.; Yoshikawa, A. [Center for SMART Green Innovation Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)

2014-04-28T23:59:59.000Z

228

Ohmic contacts to n-GaSb  

E-Print Network [OSTI]

in the semiconductor is measured during the deposition of the metal contact. In using method 1, the I-V characteristics is plotted. The thermionic emission theory predicts the current-voltage characteristics of Schottky diodes as [13]: J(rhcrmionic) = A" T' exp... of different work functions. This situation is also true for metal contacts to n-GaSb. Polyakov et al. [14] examined the Schottky diodes of Al, Au, In, Pd, Ga, and Sb on Te doped n-GaSb. They used the C-V measurements methods. They reported that barrier...

Yang, Zhengchong

2012-06-07T23:59:59.000Z

229

Study of the Detonation Phase in the Gravitationally Confined Detonation Model of Type Ia Supernovae  

Science Journals Connector (OSTI)

We study the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia) through the detonation phase and into homologous expansion. In the GCD model, a detonation is triggered by the surface flow due to single-point, off-center flame ignition in carbon-oxygen white dwarfs (WDs). The simulations are unique in terms of the degree to which nonidealized physics is used to treat the reactive flow, including weak reaction rates and a time-dependent treatment of material in nuclear statistical equilibrium (NSE). Careful attention is paid to accurately calculating the final composition of material which is burned to NSE and frozen out in the rapid expansion following the passage of a detonation wave over the high-density core of the WD; and an efficient method for nucleosynthesis postprocessing is developed which obviates the need for costly network calculations along tracer particle thermodynamic trajectories. Observational diagnostics are presented for the explosion models, including abundance stratifications and integrated yields. We find that for all of the ignition conditions studied here a self-regulating process comprised of neutronization and stellar expansion results in final 56Ni masses of ~1.1M ?. But, more energetic models result in larger total NSE and stable Fe-peak yields. The total yield of intermediate mass elements is ~0.1M ? and the explosion energies are all around 1.5 ? 1051 erg. The explosion models are briefly compared to the inferred properties of recent SN Ia observations. The potential for surface detonation models to produce lower-luminosity (lower 56Ni mass) SNe is discussed.

Casey A. Meakin; Ivo Seitenzahl; Dean Townsley; George C. Jordan IV; James Truran; Don Lamb

2009-01-01T23:59:59.000Z

230

IS WX CEN A POSSIBLE TYPE Ia SUPERNOVA PROGENITOR WITH WIND-DRIVEN MASS TRANSFER?  

SciTech Connect (OSTI)

WX Cen is one of a few compact binary supersoft X-ray sources (CBSS) in the Galaxy that is a possible Type Ia supernova (SN Ia) progenitor. The supersoft X-ray radiation is explained as hydrostatic nuclear burning on the surface of the white dwarf component that is accreting hydrogen from a stellar companion at a high rate. If the mass donor in this system has a low mass, as has been suggested in the literature, one would expect a high wind-driven mass transfer rate. In that case, the orbital period of the system should increase. To test this theoretical prediction, we have monitored the system photometrically since 2010. By using four newly determined eclipse timings together with those collected from the literature, we discovered that the orbital period is decreasing at a rate of dP/dt = -5.15 Multiplication-Sign 10{sup -7} days yr{sup -1}. The long-term decrease in the orbital period is contrary to the prediction that the system is powered by wind-driven accretion. It therefore seems plausible that the mass donor could be more massive than the white dwarf, and that the mass transfer is driven by the thermal instability of the donor star. This finding suggests that WX Cen is a key object to check the physical mechanisms of mass accretion in CBSS. The corresponding timescale of the period change is about P/P-dot {approx} 0.81 x 10{sup 6} yr, indicating that WX Cen may evolve into an SNe Ia within one million years in the Galaxy.

Qian, S.-B.; Shi, G.; Zhu, L.-Y.; Liu, L.; Zhao, E.-G.; Li, L.-J. [Yunnan Observatories, Chinese Academy of Sciences (CAS), P.O. Box 110, 650011 Kunming (China); Fernandez Lajus, E.; Di Sisto, R. P., E-mail: qsb@ynao.ac.cn [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, 1900 La Plata, Buenos Aires (Argentina)

2013-08-01T23:59:59.000Z

231

On the Thermonuclear Runaway in Type Ia Supernovae: How to run away?  

E-Print Network [OSTI]

Type Ia Supernovae are thought to be thermonuclear explosions of massive white dwarfs (WD). We present the first study of multi-dimensional effects during the final hours prior to the thermonuclear runaway which leads to the explosion. The calculations utilize an implicit, 2-D hydro code.Mixing and the ignition process are studied in detail. We find that the initial chemical structure of the WD is changed but the material is not fully homogenized. The exploding WD sustains a central region with a low C/O ratio. This implies that the explosive nuclear burning will begin in a partially C-depleted environment. The thermonuclear runaway happens in a well defined region close to the center. It is induced by compressional heat when matter is brought inwards by convective flows. We find no evidence for multiple spot or strong off-center ignition. Convective velocities are of the order of 100 km/sec which is well above the effective burning speeds in SNe Ia previously expected right after the runaway. For about 0.5 to 1 sec, the speed of the burning front will neither be determined by the laminar speed nor the Rayleigh-Taylor instabilities but by convective flows produced prior to the runaway. The consequences are discussed for our under- standing of the detailed physics of the flame propagation, the deflagration detonation transition, and the nucleosynthesis in the central layers. Our results strongly suggest the pre-conditioning of the progenitor as a key-factor for our understanding of the diversity in SNeIa.

P. Hoeflich; J. Stein

2001-12-07T23:59:59.000Z

232

Simplified 2DEG carrier concentration model for composite barrier AlGaN/GaN HEMT  

SciTech Connect (OSTI)

The self consistent solution of Schrodinger and Poisson equations is used along with the total charge depletion model and applied with a novel approach of composite AlGaN barrier based HEMT heterostructure. The solution leaded to a completely new analytical model for Fermi energy level vs. 2DEG carrier concentration. This was eventually used to demonstrate a new analytical model for the temperature dependent 2DEG carrier concentration in AlGaN/GaN HEMT.

Das, Palash, E-mail: d.palash@gmail.com; Biswas, Dhrubes, E-mail: d.palash@gmail.com [Indian Institute of Technology Kharagpur, Kharagpur - 721302, West Bengal (India)

2014-04-24T23:59:59.000Z

233

Ultra-high frequency photoconductivity decay in GaAs/Ge/GaAs double heterostructure grown by molecular beam epitaxy  

SciTech Connect (OSTI)

GaAs/Ge/GaAs double heterostructures (DHs) were grown in-situ using two separate molecular beam epitaxy chambers. High-resolution x-ray rocking curve demonstrates a high-quality GaAs/Ge/GaAs heterostructure by observing Pendelloesung oscillations. The kinetics of the carrier recombination in Ge/GaAs DHs were investigated using photoconductivity decay measurements by the incidence excitation from the front and back side of 15 nm GaAs/100 nm Ge/0.5 {mu}m GaAs/(100)GaAs substrate structure. High-minority carrier lifetimes of 1.06-1.17 {mu}s were measured when excited from the front or from the back of the Ge epitaxial layer, suggests equivalent interface quality of GaAs/Ge and Ge/GaAs. Wavelength-dependent minority carrier recombination properties are explained by the wavelength-dependent absorption coefficient of Ge.

Hudait, M. K.; Zhu, Y. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Johnston, S. W. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)] [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Maurya, D.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States); Umbel, R. [Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

2013-03-04T23:59:59.000Z

234

Reconstruction of Hessence Dark Energy and the Latest Type Ia Supernovae Gold Dataset  

E-Print Network [OSTI]

Recently, many efforts have been made to build dark energy models whose equation-of-state parameter can cross the so-called phantom divide $w_{de}=-1$. One of them is the so-called hessence dark energy model in which the role of dark energy is played by a non-canonical complex scalar field. In this work, we develop a simple method based on Hubble parameter $H(z)$ to reconstruct the hessence dark energy. As examples, we use two familiar parameterizations for $H(z)$ and fit them to the latest 182 type Ia supernovae Gold dataset. In the reconstruction, measurement errors are fully considered.

Hao Wei; Ningning Tang; Shuang Nan Zhang

2007-02-28T23:59:59.000Z

235

Reconstruction of a Deceleration Parameter from the Latest Type Ia Supernovae Gold Dataset  

E-Print Network [OSTI]

In this paper, a parameterized deceleration parameter $q(z)= 1/2 - a/(1 + z)^b$ is reconstructed from the latest type Ia supernovae gold dataset. It is found out that the transition redshift from decelerated expansion to accelerated expansion is at $z_T=0.35^{+0.14}_{-0.07}$ with $1\\sigma$ confidence level in this parameterized deceleration parameter. And, the best fit values of parameters in $1\\sigma$ errors are $a=1.56^{+0.99}_{-0.55}$ and $b=3.82^{+3.70}_{-2.27}$.

Lixin Xu; Chengwu Zhang; Baorong Chang; Hongya Liu

2007-01-17T23:59:59.000Z

236

On the Stability of Thermonuclear Burning Fronts in Type Ia Supernovae  

E-Print Network [OSTI]

The propagation of cellularly stabilized thermonuclear flames is investigated by means of numerical simulations. In Type Ia supernova explosions the corresponding burning regime establishes at scales below the Gibson length. The cellular flame stabilization - which is a result of an interplay between the Landau-Darrieus instability and a nonlinear stabilization mechanism - is studied for the case of propagation into quiescent fuel as well as interaction with vortical fuel flows. Our simulations indicate that in thermonuclear supernova explosions stable cellular flames develop around the Gibson scale and that deflagration-to-detonation transition is unlikely to be triggered from flame evolution effects here.

F. K. Roepke; W. Hillebrandt

2004-04-26T23:59:59.000Z

237

Unbiased Estimate of Dark Energy Density from Type Ia Supernova Data  

Science Journals Connector (OSTI)

Type Ia supernovae (SNe Ia) are currently the best probes of the dark energy in the universe. To constrain the nature of dark energy, we assume a flat universe and that the weak energy condition is satisfied, and we allow the density of dark energy, ?X(z), to be an arbitrary function of redshift. Using simulated data from a space-based SN pencil-beam survey, we find that by optimizing the number of parameters used to parameterize the dimensionless dark energy density, f(z) = ?X(z)/?X(z = 0), we can obtain an unbiased estimate of both f(z) and the fractional matter density of the universe, ?m. A plausible SN pencil-beam survey (with a square degree field of view and for an observational duration of 1 yr) can yield about 2000 SNe Ia with 0 ? z ? 2. Such a survey in space would yield SN peak luminosities with a combined intrinsic and observational dispersion of ?(mint) = 0.16 mag. We find that for such an idealized survey, ?m can be measured to 10% accuracy, and the dark energy density can be estimated to ~20% to z ~ 1.5, and ~20%-40% to z ~ 2, depending on the time dependence of the true dark energy density. Dark energy densities that vary more slowly can be more accurately measured. For the anticipated Supernova/Acceleration Probe (SNAP) mission, ?m can be measured to 14% accuracy, and the dark energy density can be estimated to ~20% to z ~ 1.2. Our results suggest that SNAP may gain much sensitivity to the time dependence of the dark energy density and ?m by devoting more observational time to the central pencil-beam fields to obtain more SNe Ia at z > 1.2. We use both a maximum likelihood analysis and a Monte Carlo analysis (when appropriate) to determine the errors of estimated parameters. We find that the Monte Carlo analysis gives a more accurate estimate of the dark energy density than the maximum likelihood analysis.

Yun Wang; Geoffrey Lovelace

2001-01-01T23:59:59.000Z

238

GA Solar | Open Energy Information  

Open Energy Info (EERE)

Solar Solar Jump to: navigation, search Name GA-Solar Place Madrid, Spain Zip 28045 Sector Solar Product Madrid based solar project developer, owned by Spanish industrial group Corporacion Gestamp. Coordinates 40.4203°, -3.705774° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.4203,"lon":-3.705774,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

239

Characterization of GaSb/GaAs interfacial misfit arrays using x-ray diffraction  

Science Journals Connector (OSTI)

We report a nondestructive large-area method to characterize dislocation formation at a highly lattice-mismatched interface. The analysis is based on x-ray diffraction and reciprocal space mapping using a standard lab-based diffractometer. We use this technique to identify and analyze a two-dimensional array of 90 misfit dislocations at a GaSb/GaAs interface. The full width at half maximum of the GaSb 004 reciprocal lattice point is shown to decrease with increasing GaSb epilayer thickness as expected from theoretical models. Based on these measurements the variation in the spatial dislocation frequency is calculated to be 1%.

Charles J. Reyner; Jin Wang; Kalyan Nunna; Andrew Lin; Baolai Liang; Mark S. Goorsky; D. L. Huffaker

2011-01-01T23:59:59.000Z

240

One-dimensional delayed-detonation models of Type Ia supernovae: Confrontation to observations at bolometric maximum  

E-Print Network [OSTI]

The delayed-detonation explosion mechanism applied to a Chandrasekhar-mass white dwarf offers a very attractive model to explain the inferred characteristics of Type Ia supernovae (SNe Ia). The resulting ejecta are chemically stratified, have the same mass and roughly the same asymptotic kinetic energy, but exhibit a range in 56Ni mass. We investigate the contemporaneous photometric and spectroscopic properties of a sequence of delayed-detonation models, characterized by 56Ni masses between 0.18 and 0.81 Msun. Starting at 1d after explosion, we perform the full non-LTE, time-dependent radiative transfer with the code CMFGEN, with an accurate treatment of line blanketing, and compare our results to SNe Ia at bolometric maximum. Despite the 1D treatment, our approach delivers an excellent agreement to observations. We recover the range of SN Ia luminosities, colours, and spectral characteristics from the near-UV to 1 micron, for standard as well as low-luminosity 91bg-like SNe Ia. Our models predict an increase...

Blondin, Stphane; Hillier, D John; Khokhlov, Alexei M

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

The p-Process in the Carbon Deflagration Model for Type Ia Supernovae and Chronology of the Solar System Formation  

SciTech Connect (OSTI)

We study nucleosynthesis of p-nuclei in the carbon deflagration model for Type Ia supernovae (SNe Ia) by assuming that seed nuclei are produced by the s-process in accreting layers on a carbon-oxygen white dwarf during mass accretion from a binary companion. We find that about 50 % of the p-nuclides are synthesized in proportion to the solar abundance and that p-isotopes of Mo and Ru which are significantly underproduced in Type II supernovae (SNe II) are produced up to a level close to other p-nuclei. Comparing the yields of iron and p-nuclei in SNe Ia we find that SNe Ia can contribute to the galactic evolution of the p-nuclei. Next, we consider nucleochronology of the solar system formation by using four radioactive nuclides and apply the result of the p-process nucleosynthesis to simple galactic chemical evolution models. We find that when assumed three phases of interstellar medium are mixed by the interdiffusion with the timescale of about 40 Myr 53Mn/55Mn value in the early solar system is consistent with a meteoritic value. In addition, we put constraints to a scenario that SNe Ia induce the core collapse of the molecular cloud, which leads to the formation of the solar system.

Kusakabe, Motohiko [Department of Astronomy, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Iwamoto, Nobuyuki [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Nomoto, Ken'ichi [Department of Astronomy, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2006-07-12T23:59:59.000Z

242

Stable isotope-assisted NMR characterization of interaction between lipid A and sarcotoxin IA, a cecropin-type antibacterial peptide  

SciTech Connect (OSTI)

Highlights: ? Recombinant sarcotoxin IA was successfully produced with {sup 13}C- and {sup 15}N-labeling. ? Sarcotoxin IA adopts an N-terminal ?-helix upon binding to lipid A-embedding micelles. ? Two lysine residues are involved in lipid A-mediated antibacterial activities. -- Abstract: Sarcotoxin IA is a 39-residue cecropin-type peptide from Sarcophaga peregrina. This peptide exhibits antibacterial activity against Gram-negative bacteria through its interaction with lipid A, a core component of lipopolysaccharides. To acquire detailed structural information on this specific interaction, we performed NMR analysis using bacterially expressed sarcotoxin IA analogs with {sup 13}C- and {sup 15}N-labeling along with lipid A-embedding micelles composed of dodecylphosphocholine. By inspecting the stable isotope-assisted NMR data, we revealed that the N-terminal segment (Leu3Arg18) of sarcotoxin IA formed an amphiphilic ?-helix upon its interaction with the aqueous micelles. Furthermore, chemical shift perturbation data indicated that the amino acid residues displayed on this ?-helix were involved in the specific interaction with lipid A. On the basis of these data, we successfully identified Lys4 and Lys5 as key residues in the interaction with lipid A and the consequent antibacterial activity. Therefore, these results provide unique information for designing chemotherapeutics based on antibacterial peptide structures.

Yagi-Utsumi, Maho [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan) [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Yamaguchi, Yoshiki [Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan) [Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Boonsri, Pornthip [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan) [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Iguchi, Takeshi [Bioscience Research Laboratory, Fujiya Co., Ltd., Hadano, Kanagawa 257-0031 (Japan)] [Bioscience Research Laboratory, Fujiya Co., Ltd., Hadano, Kanagawa 257-0031 (Japan); Okemoto, Kazuo [Department of Biochemistry and Cell Biology, National Institute of Infectious Disease, Tokyo 162-8640 (Japan)] [Department of Biochemistry and Cell Biology, National Institute of Infectious Disease, Tokyo 162-8640 (Japan); Natori, Shunji [National Institute of Agrobiological Sciences, Tsukuba 305-8602 (Japan)] [National Institute of Agrobiological Sciences, Tsukuba 305-8602 (Japan); Kato, Koichi, E-mail: kkatonmr@ims.ac.jp [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan) [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); The Glycoscience Institute, Ochanomizu University, Tokyo 135-0064 (Japan); GLYENCE Co., Ltd., Nagoya 474-0858 (Japan)

2013-02-08T23:59:59.000Z

243

GaNInGaN LED efficiency reduction from parasitic electron currents in p-GaN  

Science Journals Connector (OSTI)

Abstract This paper presents observations of a previously unidentified source of performance limitation for GaNInGaN LED devices. While most studies focus on output saturation known as current droop from InGaN layer effects, we show an alike influence from p-type GaNs inherent background electron concentration. p-GaN material was investigated to confirm that, even though the material had an excess of holes, the background electrons were indeed present and were influencing the charge flow across device electrodes. This current does not cross LED heterojunctions but rather drifts toward its proximal device electrode, causing a source of heating while providing no carriers for light emitting recombination. The effects of this current were explored in an LED configuration, whose output showed weak efficiency at very low biases in addition to that from current droop. While the shortcoming under small currents has previously been attributed to electron tunneling across the junction, we propose that the background electrons inside p-GaN could be another explanation.

G. Togtema; V. Georgiev; D. Georgieva; R. Gergova; K.S.A. Butcher; D. Alexandrov

2015-01-01T23:59:59.000Z

244

Category:Utility Rate Impacts on PV Economics By Location | Open Energy  

Open Energy Info (EERE)

Utility Rate Impacts on PV Economics By Location Utility Rate Impacts on PV Economics By Location Jump to: navigation, search Impact of Utility Rates on PV Economics Montgomery, AL Little Rock, AR Flagstaff, AZ Phoenix, AZ Tucson, AZ Arcata, CA LA, CA San Francisco, CA Boulder, CO Eagle County, CO Pueblo, CO Bridgeport, CT Wilmington, DE Miami, FL Tampa, FL Atlanta, GA Savannah, GA Des Moines, IA Mason, IA Boise, ID Chicago, IL Springfield, IL Indianapolis, IN Goodland, KS Wichita, KS Lexington, KY New Orleans, LA Shreveport, LA Boston, MA Baltimore, MD Caribou, ME Portland, ME Detroit, MI Houghton-Lake, MI Traverse City, MI International Falls, MN Minneapolis, MN Kansas City, MO Jackson, MS Billings, MT Greensboro, NC Wilmington, NC Bismarck, ND Minot, ND Omaha, NE Concord, NH Atlantic City, NJ Albuquerque, NM Las Vegas, NV Reno, NV New York, NY

245

GaTe semiconductor for radiation detection  

DOE Patents [OSTI]

GaTe semiconductor is used as a room-temperature radiation detector. GaTe has useful properties for radiation detectors: ideal bandgap, favorable mobilities, low melting point (no evaporation), non-hygroscopic nature, and availability of high-purity starting materials. The detector can be used, e.g., for detection of illicit nuclear weapons and radiological dispersed devices at ports of entry, in cities, and off shore and for determination of medical isotopes present in a patient.

Payne, Stephen A. (Castro Valley, CA); Burger, Arnold (Nashville, TN); Mandal, Krishna C. (Ashland, MA)

2009-06-23T23:59:59.000Z

246

Inference for the dark energy equation of state using Type IA supernova data  

E-Print Network [OSTI]

The surprising discovery of an accelerating universe led cosmologists to posit the existence of "dark energy"--a mysterious energy field that permeates the universe. Understanding dark energy has become the central problem of modern cosmology. After describing the scientific background in depth, we formulate the task as a nonlinear inverse problem that expresses the comoving distance function in terms of the dark-energy equation of state. We present two classes of methods for making sharp statistical inferences about the equation of state from observations of Type Ia Supernovae (SNe). First, we derive a technique for testing hypotheses about the equation of state that requires no assumptions about its form and can distinguish among competing theories. Second, we present a framework for computing parametric and nonparametric estimators of the equation of state, with an associated assessment of uncertainty. Using our approach, we evaluate the strength of statistical evidence for various competing models of dark energy. Consistent with current studies, we find that with the available Type Ia SNe data, it is not possible to distinguish statistically among popular dark-energy models, and that, in particular, there is no support in the data for rejecting a cosmological constant. With much more supernova data likely to be available in coming years (e.g., from the DOE/NASA Joint Dark Energy Mission), we address the more interesting question of whether future data sets will have sufficient resolution to distinguish among competing theories.

Christopher Genovese; Peter Freeman; Larry Wasserman; Robert Nichol; Christopher Miller

2008-05-27T23:59:59.000Z

247

Flame-driven deflagration-to-detonation transitions in Type Ia supernovae?  

E-Print Network [OSTI]

Although delayed detonation models of thermonuclear explosions of white dwarfs seem promising for reproducing Type Ia supernovae, the transition of the flame propagation mode from subsonic deflagration to supersonic detonation remains hypothetical. A potential instant for this transition to occur is the onset of the distributed burning regime, i.e. the moment when turbulence first affects the internal flame structure. Some studies of the burning microphysics indicate that a deflagration-to-detonation transition may be possible here, provided the turbulent intensities are strong enough. Consequently, the magnitude of turbulent velocity fluctuations generated by the deflagration flame is analyzed at the onset of the distributed burning regime in several three-dimensional simulations of deflagrations in thermonuclear supernovae. It is shown that the corresponding probability density functions fall off towards high turbulent velocity fluctuations much more slowly than a Gaussian distribution. Thus, values claimed to be necessary for triggering a detonation are likely to be found in sufficiently large patches of the flame. Although the microphysical evolution of the burning is not followed and a successful deflagration-to-detonation transition cannot be guaranteed from simulations presented here, the results still indicate that such events may be possible in Type Ia supernova explosions.

F. K. Roepke

2007-09-26T23:59:59.000Z

248

Flame Evolution During Type Ia Supernovae and the Deflagration Phase in the Gravitationally Confined Detonation Scenario  

E-Print Network [OSTI]

We develop an improved method for tracking the nuclear flame during the deflagration phase of a Type Ia supernova, and apply it to study the variation in outcomes expected from the gravitationally confined detonation (GCD) paradigm. A simplified 3-stage burning model and a non-static ash state are integrated with an artificially thickened advection-diffusion-reaction (ADR) flame front in order to provide an accurate but highly efficient representation of the energy release and electron capture in and after the unresolvable flame. We demonstrate that both our ADR and energy release methods do not generate significant acoustic noise, as has been a problem with previous ADR-based schemes. We proceed to model aspects of the deflagration, particularly the role of buoyancy of the hot ash, and find that our methods are reasonably well-behaved with respect to numerical resolution. We show that if a detonation occurs in material swept up by the material ejected by the first rising bubble but gravitationally confined to the white dwarf (WD) surface (the GCD paradigm), the density structure of the WD at detonation is systematically correlated with the distance of the deflagration ignition point from the center of the star. Coupled to a suitably stochastic ignition process, this correlation may provide a plausible explanation for the variety of nickel masses seen in Type Ia Supernovae.

D. M. Townsley; A. C. Calder; S. M. Asida; I. R. Seitenzahl; F. Peng; N. Vladimirova; D. Q. Lamb; J. W. Truran

2007-06-07T23:59:59.000Z

249

Constraining a bulk viscous matter-dominated cosmological model using SNe Ia, CMB and LSS  

E-Print Network [OSTI]

We present and constrain a cosmological model which component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a constant bulk viscosity coefficient \\zeta_m. The possible values of \\zeta_m are constrained using the cosmological tests of SNe Ia Gold 2006 sample, the CMB shift parameter R from the three-year WMAP observations, the Baryon Acoustic Oscillation (BAO) peak A from the Sloan Digital Sky Survey (SDSS) and the Second Law of Thermodynamics (SLT). It was found that this model is in agreement with the SLT using only the SNe Ia test. However when the model is submitted to the three cosmological tests together (SNe+CMB+BAO) the results are: 1.- the model violates the SLT, 2.- predicts a value of H_0 \\approx 53 km sec^{-1} Mpc^{-1} for the Hubble constant, and 3.- we obtain a bad fit to data with a \\chi^2_{min} \\approx 400 (\\chi^2_{d.o.f.} \\approx 2.2). These results indicate that this model is ruled out by the observations.

Arturo Avelino; U. Nucamendi; F. S. Guzmn

2008-01-10T23:59:59.000Z

250

Parametrizing the transition to the phantom epoch with Supernovae Ia and Standard Rulers  

E-Print Network [OSTI]

The properties of some particular parametrizations of the dark energy Equation of State (EoS) are studied by using Supernovae Ia data (HST Cluster Supernova Survey) combined with Standard Ruler datasets (Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO)). In this sense, we propose some parametrizations that may present a (fast) transition to a phantom dark energy EoS (where $w_{DE}<-1$) and compare the results with the $\\Lambda$CDM model. The best fit of the models is obtained by using Sne Ia and Standard Ruler datasets, which provides some information about whether the phantom transition may be supported by the observations. In this regard, the crossing of the phantom barrier is allowed statistically but the occurrence of a future singularity seems unlikely. Furthermore, the reconstruction of a (non-)canonical scalar field Lagrangian from the EoS parameter is studied, where shown that EoS parametrizations can be well reconstructed in terms of scalar fields.

Leanizbarrutia, Iker

2014-01-01T23:59:59.000Z

251

Verifying the Cosmological Utility of Type Ia Supernovae:Implications of a Dispersion in the Ultraviolet Spectra  

SciTech Connect (OSTI)

We analyze the mean rest-frame ultraviolet (UV) spectrum ofType Ia Supernovae(SNe) and its dispersion using high signal-to-noiseKeck-I/LRIS-B spectroscopyfor a sample of 36 events at intermediateredshift (z=0.5) discoveredby the Canada-France-Hawaii TelescopeSupernova Legacy Survey (SNLS). Weintroduce a new method for removinghost galaxy contamination in our spectra,exploiting the comprehensivephotometric coverage of the SNLS SNe and theirhost galaxies, therebyproviding the first quantitative view of the UV spectralproperties of alarge sample of distant SNe Ia. Although the mean SN Ia spectrumhas notevolved significantly over the past 40 percent of cosmic history,preciseevolutionary constraints are limited by the absence of acomparable sample ofhigh quality local spectra. The mean UV spectrum ofour z 0.5 SNe Ia and itsdispersion is tabulated for use in futureapplications. Within the high-redshiftsample, we discover significant UVspectral variations and exclude dust extinctionas the primary cause byexamining trends with the optical SN color. Although progenitormetallicity may drive some of these trends, the variations we see aremuchlarger than predicted in recent models and do not follow expectedpatterns.An interesting new result is a variation seen in the wavelengthof selected UVfeatures with phase. We also demonstrate systematicdifferences in the SN Iaspectral features with SN lightcurve width inboth the UV and the optical. Weshow that these intrinsic variations couldrepresent a statistical limitation in thefuture use of high-redshift SNeIa for precision cosmology. We conclude thatfurther detailed studies areneeded, both locally and at moderate redshift wherethe rest-frame UV canbe studied precisely, in order that future missions canconfidently beplanned to fully exploit SNe Ia as cosmological probes.

Ellis, R.S.; Sullivan, M.; Nugent, P.E.; Howell, D.A.; Gal-Yam,A.; Astier, P.; Balam, D.; Balland, C.; Basa, S.; Carlberg, R.G.; Conley,A.; Fouchez, D.; Guy, J.; Hardin, D.; Hook, I.; Pain, R.; Perrett, K.; Pritchet, C.J.; Regnault, N.

2007-11-02T23:59:59.000Z

252

Direct-bonded GaAs/InGaAs tandem solar cell Katsuaki Tanabe,a  

E-Print Network [OSTI]

Direct-bonded GaAs/InGaAs tandem solar cell Katsuaki Tanabe,a Anna Fontcuberta i Morral,b and Harry, Pasadena, California 91125 Daniel J. Aiken Emcore Photovoltaics, Albuquerque, New Mexico 87123 Mark W. Wanlass National Renewable Energy Laboratory, Golden, Colorado 80401 Received 19 March 2006; accepted 26

Atwater, Harry

253

Lattice-matched epitaxial GaInAsSb/GaSb thermophotovoltaic devices  

SciTech Connect (OSTI)

The materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for lattice-matched thermophotovoltaic (TPV) devices is reported. Epilayers with cutoff wavelength 2--2.4 {micro}m at room temperature and lattice-matched to GaSb substrates were grown by both low-pressure organometallic vapor phase epitaxy and molecular beam epitaxy. These layers exhibit high optical and structural quality. For demonstrating lattice-matched thermophotovoltaic devices, p- and n-type doping studies were performed. Several TPV device structures were investigated, with variations in the base/emitter thicknesses and the incorporation of a high bandgap GaSb or AlGaAsSb window layer. Significant improvement in the external quantum efficiency is observed for devices with an AlGaAsSb window layer compared to those without one.

Wang, C.A.; Choi, H.K.; Turner, G.W.; Spears, D.L.; Manfra, M.J. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

254

Study and development of tunable, single mode AlGaAs/GaAs lasers  

SciTech Connect (OSTI)

Liquid phase epitaxy has been employed in this study to fabricate two-section wavelength tunable lasers. GaAs/AlGaAs and In GaAsP/InP material system have been used for fabricating the lasers. Both direct (butt) coupling and evanescent coupling approaches have been studied. The complications associated with the regrowth process have been responsible for poor laser performance. Some DBR gratings for three-section lasers have been made using the electron beam lithography at UCSD. A simple set up has been tested to measure the wavelength shift of GaAs/AlGaAs lasers. Also, a simple structure which avoids the regrowth process has been proposed for the two-section laser. 9 refs., 14 figs.

Yu, P.K.L.; Liu, J.C. (California Univ., San Diego, La Jolla, CA (USA). Dept. of Electrical and Computer Engineering)

1990-09-01T23:59:59.000Z

255

Auditory Menus Are Not Just Spoken Visual Menus: A Case Study of  

E-Print Network [OSTI]

Interface Copyright is held by the author/owner(s). CHI 2010, April 10­15, 2010, Atlanta, Georgia, USA. ACM Institute of Technology 654 Cherry Street, Atlanta, GA, 30332 USA davison@gatech.edu Bruce N. Walker Street, Atlanta, GA, 30332 USA bruce.walker@psych.gatech.edu CHI 2010: Work-in-Progress (Spotlight

256

CIMAT, VIII Escuela de verano, 30 de julio -10 de ago* Introducci'on a la Geometr'ia de la Mec'ani*  

E-Print Network [OSTI]

conservativo. 18.Sea A(E) el 'area dentro de una curva de fase cerrada que corresponde a nive* *l de energ'ia Introducci'on a la Geometr'ia de la Mec'ani* *ca Cl'asica Problemas 13 - 19

Bor, Gil

257

Defect studies in low-temperature-grown GaAs  

SciTech Connect (OSTI)

High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V{sub Ga}. The neutral AsGa-related defects were measured by infrared absorption at 1{mu}m. Gallium vacancies, V{sub Ga}, was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10{sup 19} cm{sup {minus}3} Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As{sub Ga} in the layer. As As{sub Ga} increases, photoquenchable As{sub Ga} decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As{sub Ga} content around 500C, similar to irradiation damaged and plastically deformed Ga{sub As}, as opposed to bulk grown GaAs in which As{sub Ga}-related defects are stable up to 1100C. The lower temperature defect removal is due to V{sub Ga} enhanced diffusion of As{sub Ga} to As precipitates. The supersaturated V{sub GA} and also decreases during annealing. Annealing kinetics for As{sub Ga}-related defects gives 2.0 {plus_minus} 0.3 eV and 1.5 {plus_minus} 0.3 eV migration enthalpies for the As{sub Ga} and V{sub Ga}. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As{sub Ga}-related defects anneal with an activation energy of 1.1 {plus_minus} 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As{sub Ga}-Be{sub Ga} pairs. Si donors can only be partially activated.

Bliss, D.E.

1992-11-01T23:59:59.000Z

258

Defect studies in low-temperature-grown GaAs  

SciTech Connect (OSTI)

High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

Bliss, D.E.

1992-11-01T23:59:59.000Z

259

LATE-TIME SPECTRAL OBSERVATIONS OF THE STRONGLY INTERACTING TYPE Ia SUPERNOVA PTF11kx  

SciTech Connect (OSTI)

PTF11kx was a Type Ia supernova (SN Ia) that showed time-variable absorption features, including saturated Ca II H and K lines that weakened and eventually went into emission. The strength of the emission component of H{alpha} gradually increased, implying that the SN was undergoing significant interaction with its circumstellar medium (CSM). These features, and many others, were blueshifted slightly and showed a P-Cygni profile, likely indicating that the CSM was directly related to, and probably previously ejected by, the progenitor system itself. These and other observations led Dilday et al. to conclude that PTF11kx came from a symbiotic nova progenitor like RS Oph. In this work we extend the spectral coverage of PTF11kx to 124-680 rest-frame days past maximum brightness. The late-time spectra of PTF11kx are dominated by H{alpha} emission (with widths of full width at half-maximum intensity Almost-Equal-To 2000 km s{sup -1}), strong Ca II emission features ({approx}10,000 km s{sup -1} wide), and a blue 'quasi-continuum' due to many overlapping narrow lines of Fe II. Emission from oxygen, He I, and Balmer lines higher than H{alpha} is weak or completely absent at all epochs, leading to large observed H{alpha}/H{beta} intensity ratios. The H{alpha} emission appears to increase in strength with time for {approx}1 yr, but it subsequently decreases significantly along with the Ca II emission. Our latest spectrum also indicates the possibility of newly formed dust in the system as evidenced by a slight decrease in the red wing of H{alpha}. During the same epochs, multiple narrow emission features from the CSM temporally vary in strength. The weakening of the H{alpha} and Ca II emission at late times is possible evidence that the SN ejecta have overtaken the majority of the CSM and agrees with models of other strongly interacting SNe Ia. The varying narrow emission features, on the other hand, may indicate that the CSM is clumpy or consists of multiple thin shells.

Silverman, Jeffrey M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Nugent, Peter E.; Filippenko, Alexei V.; Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Pan, Yen-Chen; Hook, Isobel M., E-mail: jsilverman@astro.as.utexas.edu [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

2013-08-01T23:59:59.000Z

260

SciTech Connect: "light emitting diodes"  

Office of Scientific and Technical Information (OSTI)

light emitting diodes" Find light emitting diodes" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

SciTech Connect: "August 2003 blackout"  

Office of Scientific and Technical Information (OSTI)

August 2003 blackout" Find August 2003 blackout" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

262

SciTech Connect: "solar plasma wind"  

Office of Scientific and Technical Information (OSTI)

solar plasma wind" Find solar plasma wind" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

263

SciTech Connect: "gamma ray bursts"  

Office of Scientific and Technical Information (OSTI)

gamma ray bursts" Find gamma ray bursts" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

264

Energy absorption in Ni-Mn-Ga/ polymer composites  

E-Print Network [OSTI]

In recent years Ni-Mn-Ga has attracted considerable attention as a new kind of actuator material. Off-stoichiometric single crystals of Ni2MnGa can regularly exhibit 6% strain in tetragonal martensites and orthorhombic ...

Feuchtwanger, Jorge

2006-01-01T23:59:59.000Z

265

Type Ia supernova diversity: white dwarf central density as a secondary parameter in three-dimensional delayed detonation models  

Science Journals Connector (OSTI)

......function of redshift. The standard model of SNe Ia relies on the nuclear fusion of the initial composition (predominantly 12C and 16O) of...generated from a Monte Carlo based algorithm. The primary input parameters are the number of the ignition kernels and the......

I. R. Seitenzahl; F. Ciaraldi-Schoolmann; F. K. Rpke

2011-07-01T23:59:59.000Z

266

EARLY RADIO AND X-RAY OBSERVATIONS OF THE YOUNGEST NEARBY TYPE Ia SUPERNOVA PTF 11kly (SN 2011fe)  

SciTech Connect (OSTI)

On 2011 August 24 (UT) the Palomar Transient Factory (PTF) discovered PTF11kly (SN 2011fe), the youngest and most nearby Type Ia supernova (SN Ia) in decades. We followed this event up in the radio (centimeter and millimeter bands) and X-ray bands, starting about a day after the estimated explosion time. We present our analysis of the radio and X-ray observations, yielding the tightest constraints yet placed on the pre-explosion mass-loss rate from the progenitor system of this supernova. We find a robust limit of M-dot {approx}<10{sup -8}(w/100 km s{sup -1}) M{sub sun} yr{sup -1} from sensitive X-ray non-detections, as well as a similar limit from radio data, which depends, however, on assumptions about microphysical parameters. We discuss our results in the context of single-degenerate models for SNe Ia and find that our observations modestly disfavor symbiotic progenitor models involving a red giant donor, but cannot constrain systems accreting from main-sequence or sub-giant stars, including the popular supersoft channel. In view of the proximity of PTF11kly and the sensitivity of our prompt observations, we would have to wait for a long time (a decade or longer) in order to more meaningfully probe the circumstellar matter of SNe Ia.

Horesh, Assaf; Kulkarni, S. R.; Carpenter, John; Kasliwal, Mansi M.; Ofek, Eran O. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Fox, Derek B. [Astronomy and Astrophysics, Eberly College of Science, Pennsylvania State University, University Park, PA 16802 (United States); Quimby, Robert [IPMU, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba (Japan); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); De Bruyn, A. G. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, NL-7990 AA Dwingeloo (Netherlands); Kamble, Atish; Wijers, Ralph A. M. J. [Center for Gravitation and Cosmology, University of Wisconsin, Milwaukee, WI 53211 (United States); Van der Horst, Alexander J. [Universities Space Research Association, NSSTC, Huntsville, AL 35805 (United States); Kouveliotou, Chryssa [Space Science Office, VP-62, NASA-Marshall Space Flight Center, Huntsville, AL 35805 (United States); Podsiadlowski, Philipp; Sullivan, Mark; Maguire, Kate [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Santa Barbara, CA 93117 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Gehrels, Neil [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); and others

2012-02-10T23:59:59.000Z

267

Experto Universitario Java Enterprise Validacin e internacionalizacin 2012-2013 Depto. Ciencia de la Computacin e IA Spring  

E-Print Network [OSTI]

Experto Universitario Java Enterprise Validación e internacionalización © 2012-2013 Depto. Ciencia #12;Experto Universitario Java Enterprise Validación e internacionalización © 2012-2013 Depto. Ciencia Java Enterprise Validación e internacionalización © 2012-2013 Depto. Ciencia de la Computación e IA

Escolano, Francisco

268

TheThe ScienceScience ForumForum (as I(as I picturepicture itit)) Scholarly work  

E-Print Network [OSTI]

#12;Robotics TheThe ScienceScience ForumForum (as I(as I picturepicture itit)) Humanities Scholarly of photonics, robotics, telematics, dynamic physical rendering and intelligent sensors served as the basis to inspire four bestselling authors. The results are four short stories which paint amusing, thought

Torras, Carme

269

EXCELLENTIA CoLumbIA ENgINEErINg66 echanical engineers think about the design, construction, material proper-  

E-Print Network [OSTI]

responsibility for understanding how engines work, how buildings can be more efficiently built, and howHEALTH EXCELLENTIA CoLumbIA ENgINEErINg66 M echanical engineers think about the design the environment affects bridge architecture. They also apply their knowledge to the workings of the human body

Hone, James

270

ANALYSIS OF LIMIT CYCLE STABILITY IN A TAP-CHANGING TRANSFORMER V. Donde I.A. Hiskens  

E-Print Network [OSTI]

ANALYSIS OF LIMIT CYCLE STABILITY IN A TAP-CHANGING TRANSFORMER V. Donde I.A. Hiskens Department of transformer tap changing and load dynamics. Lin- earization of a Poincar´e map is used to prove local of the region of attraction can then be obtained. 1. INTRODUCTION Interactions between tap-changing transformers

Hiskens, Ian A.

271

A Precision Photometric Comparison between SDSS-II and CSP Type Ia Supernova Data  

E-Print Network [OSTI]

Consistency between Carnegie Supernova Project (CSP) and SDSS-II supernova (SN) survey ugri measurements has been evaluated by comparing SDSS and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023 magnitude level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011 magnitudes in ugri, with rms scatter ranging from 0.043 to 0.077 magnitudes. The u band agreement is promising, with the caveat that only four of the nine supernovae are well-observed in u and these four exhibit an 0.038 magnitude supernova-to-supernova scatter in this filter.

Mosher, J; Corlies, L; Folatelli, G; Frieman, J; Holtzman, J; Jha, S W; Kessler, R; Marriner, J; Phillips, M M; Stritzinger, M; Morrell, N; Schneider, D P

2012-01-01T23:59:59.000Z

272

Beyond the bubble catastrophe of Type Ia supernovae: Pulsating Reverse Detonation models  

E-Print Network [OSTI]

We describe a mechanism by which a failed deflagration of a Chandrasekhar-mass carbon-oxygen white dwarf can turn into a successful thermonuclear supernova explosion, without invoking an ad hoc high-density deflagration-detonation transition. Following a pulsating phase, an accretion shock develops above a core of 1 M_sun composed of carbon and oxygen, inducing a converging detonation. A three-dimensional simulation of the explosion produced a kinetic energy of 1.05E51 ergs and 0.70 M_sun of 56Ni, ejecting scarcely 0.01 M_sun of C-O moving at low velocities. The mechanism works under quite general conditions and is flexible enough to account for the diversity of normal Type Ia supernovae. In given conditions the detonation might not occur, which would reflect in peculiar signatures in the gamma and UV-wavelengths

Eduardo Bravo; Domingo Garcia-Senz

2006-04-03T23:59:59.000Z

273

Sensitivity study of explosive nucleosynthesis in type Ia supernovae: Modification of individual thermonuclear reaction rates  

Science Journals Connector (OSTI)

Background: Type Ia supernovae contribute significantly to the nucleosynthesis of many Fe-group and intermediate-mass elements. However, the robustness of nucleosynthesis obtained via models of this class of explosions has not been studied in depth until now.Purpose: We explore the sensitivity of the nucleosynthesis resulting from thermonuclear explosions of massive white dwarfs with respect to uncertainties in nuclear reaction rates. We put particular emphasis on indentifying the individual reactions rates that most strongly affect the isotopic products of these supernovae.Method: We have adopted a standard one-dimensional delayed detonation model of the explosion of a Chandrasekhar-mass white dwarf and have postprocessed the thermodynamic trajectories of every mass shell with a nucleosynthetic code to obtain the chemical composition of the ejected matter. We have considered increases (decreases) by a factor of 10 on the rates of 1196 nuclear reactions (simultaneously with their inverse reactions), repeating the nucleosynthesis calculations after modification of each reaction rate pair. We have computed as well hydrodynamic models for different rates of the fusion reactions of 12C and of 16O. From the calculations we have selected the reactions that have the largest impact on the supernova yields, and we have computed again the nucleosynthesis using two or three alternative prescriptions for their rates, taken from the JINA REACLIB database. For the three reactions with the largest sensitivity we have analyzed as well the temperature ranges where a modification of their rates has the strongest effect on nucleosynthesis.Results: The nucleosynthesis resulting from the type Ia supernova models is quite robust with respect to variations of nuclear reaction rates, with the exception of the reaction of fusion of two 12C nuclei. The energy of the explosion changes by less than ?4% when the rates of the reactions 12C+12C or 16O+16O are multiplied by a factor of 10 or 0.1. The changes in the nucleosynthesis owing to the modification of the rates of these fusion reactions are also quite modest; for instance, no species with a mass fraction larger than 0.02 experiences a variation of its yield larger than a factor of 2. We provide the sensitivity of the yields of the most abundant species with respect to the rates of the most intense reactions with protons, neutrons, and ?. In general, the yields of Fe-group nuclei are more robust than the yields of intermediate-mass elements. Among the species with yields larger than 10?8M?, 35S has the largest sensitivity to the nuclear reaction rates. It is remarkable that the reactions involving elements with Z>22 have a tiny influence on the supernova nucleosynthesis. Among the charged-particle reactions, the most influential on supernova nucleosynthesis are 30Si+p?31P+?, 20Ne+??24Mg+?, and 24Mg+??27Al+p. The temperatures at which a modification of their rate has a larger impact are in the range 2?T?4 GK.Conclusions: The explosion model (i.e., the assumed conditions and propagation of the flame) chiefly determines the element production of type Ia supernovae and derived quantities such as their luminosity, while the nuclear reaction rates used in the simulations have a small influence on the kinetic energy and final chemical composition of the ejecta. Our results show that the uncertainty in individual thermonuclear reaction rates cannot account for discrepancies of a factor of 2 between isotopic ratios in type Ia supernovae and those in the solar system, especially within the Fe group.

Eduardo Bravo and Gabriel Martnez-Pinedo

2012-05-18T23:59:59.000Z

274

A PRECISION PHOTOMETRIC COMPARISON BETWEEN SDSS-II AND CSP TYPE Ia SUPERNOVA DATA  

SciTech Connect (OSTI)

Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023 mag level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011 mag in ugri, with rms scatter ranging from 0.043 to 0.077 mag. The u-band agreement is promising, with the caveat that only four of the nine supernovae are well observed in u and these four exhibit an 0.038 mag supernova-to-supernova scatter in this filter.

Mosher, J.; Sako, M.; Corlies, L. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Folatelli, G. [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Frieman, J.; Kessler, R. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Holtzman, J. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Jha, S. W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Marriner, J. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Phillips, M. M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Stritzinger, M. [Oskar Klein Centre for Cosmo Particle Physics, AlbaNova University Center, 106 91 Stockholm (Sweden); Schneider, D. P., E-mail: jmosher@sas.upenn.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

2012-07-15T23:59:59.000Z

275

A Precision Photometric Comparison between SDSS-II and CSP Type Ia Supernova Data  

SciTech Connect (OSTI)

Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023 mag level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011 mag in ugri, with rms scatter ranging from 0.043 to 0.077 mag. The u-band agreement is promising, with the caveat that only four of the nine supernovae are well observed in u and these four exhibit an 0.038 mag supernova-to-supernova scatter in this filter.

Mosher, J.; /Pennsylvania U.; Sako, M.; /Pennsylvania U.; Corlies, L.; /Pennsylvania U. /Columbia U.; Folatelli, G.; /Tokyo U. /Carnegie Inst. Observ.; Frieman, J.; /Chicago U., KICP /Chicago U., Astron. Astrophys. Ctr.; Holtzman, J.; /New Mexico State U.; Jha, S.W.; /Rutgers U., Piscataway; Kessler, R.; /Chicago U., Astron. Astrophys. Ctr. /Chicago U., KICP; Marriner, J.; /Fermilab; Phillips, M.M.; /Carnegie Inst. Observ.; Stritzinger, M.; /Aarhus U. /Stockholm U., OKC /Bohr Inst. /Carnegie Inst. Observ.

2012-06-01T23:59:59.000Z

276

{chi}{sup 2} versus median statistics in supernova type Ia data analysis  

SciTech Connect (OSTI)

In this paper we compare the performances of the {chi}{sup 2} and median likelihood analysis in the determination of cosmological constraints using type Ia supernovae data. We perform a statistical analysis using the 307 supernovae of the Union 2 compilation of the Supernova Cosmology Project and find that the {chi}{sup 2} statistical analysis yields tighter cosmological constraints than the median statistic if only supernovae data is taken into account. We also show that when additional measurements from the cosmic microwave background and baryonic acoustic oscillations are considered, the combined cosmological constraints are not strongly dependent on whether one applies the {chi}{sup 2} statistic or the median statistic to the supernovae data. This indicates that, when complementary information from other cosmological probes is taken into account, the performances of the {chi}{sup 2} and median statistics are very similar, demonstrating the robustness of the statistical analysis.

Barreira, A. [Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Avelino, P. P. [Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2011-10-15T23:59:59.000Z

277

Small-scale Interaction of Turbulence with Thermonuclear Flames in Type Ia Supernovae  

E-Print Network [OSTI]

Microscopic turbulence-flame interactions of thermonuclear fusion flames occuring in Type Ia Supernovae were studied by means of incompressible direct numerical simulations with a highly simplified flame description. The flame is treated as a single diffusive scalar field with a nonlinear source term. It is characterized by its Prandtl number, Pr << 1, and laminar flame speed, S_L. We find that if S_L ~ u', where u' is the rms amplitude of turbulent velocity fluctuations, the local flame propagation speed does not significantly deviate from S_L even in the presence of velocity fluctuations on scales below the laminar flame thickness. This result is interpreted in the context of subgrid-scale modeling of supernova explosions and the mechanism for deflagration-detonation-transitions.

J. C. Niemeyer; W. K. Bushe; G. R. Ruetsch

1999-05-07T23:59:59.000Z

278

Initiation of the Detonation in the Gravitationally Confined Detonation Model of Type Ia Supernovae  

Science Journals Connector (OSTI)

We study the initiation of the detonation in the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia). In this model, ignition occurs at one or several off-center points, resulting in a burning bubble of hot ash that rises rapidly, breaks through the surface of the star, and collides at a point on the stellar surface opposite the breakout, producing a high-velocity inwardly directed flow. Initiation of the detonation occurs spontaneously in a region where the length scale of the temperature gradient extending from the flow (in which carbon burning is already occurring) into unburned fuel is commensurate to the range of critical length scales which have been derived from one-dimensional simulations that resolve the initiation of a detonation. By increasing the maximum resolution in a truncated cone that encompasses this region, beginning somewhat before initiation of the detonation occurs, we successfully simulate in situ the first gradient-initiated detonation in a whole-star simulation. The detonation emerges when a compression wave overruns a pocket of fuel situated in a Kelvin-Helmholtz cusp at the leading edge of the inwardly directed jet of burning carbon. The compression wave preconditions the temperature in the fuel in such a way that the Zel'dovich gradient mechanism can operate and a detonation ensues. We explore the dependence of the length scale of the temperature gradient on spatial resolution and discuss the implications for the robustness of this detonation mechanism. We find that the time and the location at which initiation of the detonation occurs varies with resolution. In particular, initiation of a detonation had not yet occurred in our highest resolution simulation by the time we ended the simulation because of the computational demand it required. However, it may detonate later. We suggest that the turbulent shear layer surrounding the inwardly directed jet provides the most favorable physical conditions, and therefore the most likely location, for initiation of a detonation in the GCD model.

Ivo R. Seitenzahl; Casey A. Meakin; Don Q. Lamb; James W. Truran

2009-01-01T23:59:59.000Z

279

Study of the Detonation Phase in the Gravitationally Confined Detonation Model of Type Ia Supernovae  

E-Print Network [OSTI]

We study the gravitationally confined detonation (GCD) model of Type Ia supernovae through the detonation phase and into homologous expansion. In the GCD model, a detonation is triggered by the surface flow due to single point, off-center flame ignition in carbon-oxygen white dwarfs. The simulations are unique in terms of the degree to which non-idealized physics is used to treat the reactive flow, including weak reaction rates and a time dependent treatment of material in nuclear statistical equilibrium (NSE). Careful attention is paid to accurately calculating the final composition of material which is burned to NSE and frozen out in the rapid expansion following the passage of a detonation wave over the high density core of the white dwarf; and an efficient method for nucleosynthesis post-processing is developed which obviates the need for costly network calculations along tracer particle thermodynamic trajectories. Observational diagnostics are presented for the explosion models, including abundance stratifications and integrated yields. We find that for all of the ignition conditions studied here, a self regulating process comprised of neutronization and stellar expansion results in final \\iso{Ni}{56} masses of $\\sim$1.1\\msun. But, more energetic models result in larger total NSE and stable Fe peak yields. The total yield of intermediate mass elements is $\\sim0.1$\\msun and the explosion energies are all around 1.5$\\times10^{51}$ ergs. The explosion models are briefly compared to the inferred properties of recent Type Ia supernova observations. The potential for surface detonation models to produce lower luminosity (lower \\iso{Ni}{56} mass) supernovae is discussed.

Casey A. Meakin; Ivo Seitenzahl; Dean Townsley; George C. Jordan IV; James Truran; Don Lamb

2008-06-30T23:59:59.000Z

280

Initiation of the detonation in the gravitationally confined detonation model of type Ia supernovae.  

SciTech Connect (OSTI)

We study the initiation of the detonation in the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia). In this model, ignition occurs at one or several off-center points, resulting in a burning bubble of hot ash that rises rapidly, breaks through the surface of the star, and collides at a point on the stellar surface opposite the breakout, producing a high-velocity inwardly directed flow. Initiation of the detonation occurs spontaneously in a region where the length scale of the temperature gradient extending from the flow (in which carbon burning is already occurring) into unburned fuel is commensurate to the range of critical length scales which have been derived from one-dimensional simulations that resolve the initiation of a detonation. By increasing the maximum resolution in a truncated cone that encompasses this region, beginning somewhat before initiation of the detonation occurs, we successfully simulate in situ the first gradient-initiated detonation in a whole-star simulation. The detonation emerges when a compression wave overruns a pocket of fuel situated in a Kelvin-Helmholtz cusp at the leading edge of the inwardly directed jet of burning carbon. The compression wave preconditions the temperature in the fuel in such a way that the Zel'dovich gradient mechanism can operate and a detonation ensues. We explore the dependence of the length scale of the temperature gradient on spatial resolution and discuss the implications for the robustness of this detonation mechanism. We find that the time and the location at which initiation of the detonation occurs varies with resolution. In particular, initiation of a detonation had not yet occurred in our highest resolution simulation by the time we ended the simulation because of the computational demand it required. However, it may detonate later. We suggest that the turbulent shear layer surrounding the inwardly directed jet provides the most favorable physical conditions, and therefore the most likely location, for initiation of a detonation in the GCD model.

Seitenzahl, I. R.; Meakin, C. A.; Lamb, D. Q.; Truran, J. W. (Physics); (Univ. of Chicago); (Max-Planck-Inst. for Astrophysics); (Univ. of Arizona)

2009-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Study of the detonation phase in the gravitationally confined detonation model of type Ia supernovae.  

SciTech Connect (OSTI)

We study the initiation of the detonation in the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia). In this model, ignition occurs at one or several off-center points, resulting in a burning bubble of hot ash that rises rapidly, breaks through the surface of the star, and collides at a point on the stellar surface opposite the breakout, producing a high-velocity inwardly directed flow. Initiation of the detonation occurs spontaneously in a region where the length scale of the temperature gradient extending from the flow (in which carbon burning is already occurring) into unburned fuel is commensurate to the range of critical length scales which have been derived from one-dimensional simulations that resolve the initiation of a detonation. By increasing the maximum resolution in a truncated cone that encompasses this region, beginning somewhat before initiation of the detonation occurs, we successfully simulate in situ the first gradient-initiated detonation in a whole-star simulation. The detonation emerges when a compression wave overruns a pocket of fuel situated in a Kelvin-Helmholtz cusp at the leading edge of the inwardly directed jet of burning carbon. The compression wave preconditions the temperature in the fuel in such a way that the Zeldovich gradient mechanism can operate and a detonation ensues. We explore the dependence of the length scale of the temperature gradient on spatial resolution and discuss the implications for the robustness of this detonation mechanism. We find that the time and the location at which initiation of the detonation occurs varies with resolution. In particular, initiation of a detonation had not yet occurred in our highest resolution simulation by the time we ended the simulation because of the computational demand it required. However, it may detonate later. We suggest that the turbulent shear layer surrounding the inwardly directed jet provides the most favorable physical conditions, and therefore the most likely location, for initiation of a detonation in the GCD model.

Meakin, C. A.; Seitenzahl, I.; Jordan, G. C.; Truran,, J.; Lamb, D.; Physics; Univ. of Chicago; Univ. of Arizona

2009-07-20T23:59:59.000Z

282

NUCLEOSYNTHESIS IN TWO-DIMENSIONAL DELAYED DETONATION MODELS OF TYPE Ia SUPERNOVA EXPLOSIONS  

SciTech Connect (OSTI)

For the explosion mechanism of Type Ia supernovae (SNe Ia), different scenarios have been suggested. In these, the propagation of the burning front through the exploding white dwarf (WD) star proceeds in different modes, and consequently imprints of the explosion model on the nucleosynthetic yields can be expected. The nucleosynthetic characteristics of various explosion mechanisms are explored based on three two-dimensional explosion simulations representing extreme cases: a pure turbulent deflagration, a delayed detonation following an approximately spherical ignition of the initial deflagration, and a delayed detonation arising from a highly asymmetric deflagration ignition. Apart from this initial condition, the deflagration stage is treated in a parameter-free approach. The detonation is initiated when the turbulent burning enters the distributed burning regime. This occurs at densities around 10{sup 7} g cm{sup -3}-relatively low as compared to existing nucleosynthesis studies for one-dimensional spherically symmetric models. The burning in these multidimensional models is different from that in one-dimensional simulations as the detonation wave propagates both into unburned material in the high-density region near the center of a WD and into the low-density region near the surface. Thus, the resulting yield is a mixture of different explosive burning products, from carbon-burning products at low densities to complete silicon-burning products at the highest densities, as well as electron-capture products synthesized at the deflagration stage. Detailed calculations of the nucleosynthesis in all three models are presented. In contrast to the deflagration model, the delayed detonations produce a characteristic layered structure and the yields largely satisfy constraints from Galactic chemical evolution. In the asymmetric delayed detonation model, the region filled with electron capture species (e.g., {sup 58}Ni, {sup 54}Fe) is within a shell, showing a large off-set, above the bulk of {sup 56}Ni distribution, while species produced by the detonation are distributed more spherically.

Maeda, K. [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Roepke, F.K.; Fink, M.; Hillebrandt, W.; Travaglio, C. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, 85741 Garching (Germany); Thielemann, F.-K., E-mail: keiichi.maeda@ipmu.j [Department Physik, Universitaet Basel, CH-4056 Basel (Switzerland)

2010-03-20T23:59:59.000Z

283

INITIATION OF THE DETONATION IN THE GRAVITATIONALLY CONFINED DETONATION MODEL OF TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

We study the initiation of the detonation in the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia). In this model, ignition occurs at one or several off-center points, resulting in a burning bubble of hot ash that rises rapidly, breaks through the surface of the star, and collides at a point on the stellar surface opposite the breakout, producing a high-velocity inwardly directed flow. Initiation of the detonation occurs spontaneously in a region where the length scale of the temperature gradient extending from the flow (in which carbon burning is already occurring) into unburned fuel is commensurate to the range of critical length scales which have been derived from one-dimensional simulations that resolve the initiation of a detonation. By increasing the maximum resolution in a truncated cone that encompasses this region, beginning somewhat before initiation of the detonation occurs, we successfully simulate in situ the first gradient-initiated detonation in a whole-star simulation. The detonation emerges when a compression wave overruns a pocket of fuel situated in a Kelvin-Helmholtz cusp at the leading edge of the inwardly directed jet of burning carbon. The compression wave preconditions the temperature in the fuel in such a way that the Zel'dovich gradient mechanism can operate and a detonation ensues. We explore the dependence of the length scale of the temperature gradient on spatial resolution and discuss the implications for the robustness of this detonation mechanism. We find that the time and the location at which initiation of the detonation occurs varies with resolution. In particular, initiation of a detonation had not yet occurred in our highest resolution simulation by the time we ended the simulation because of the computational demand it required. However, it may detonate later. We suggest that the turbulent shear layer surrounding the inwardly directed jet provides the most favorable physical conditions, and therefore the most likely location, for initiation of a detonation in the GCD model.

Seitenzahl, Ivo R. [Department of Physics, University of Chicago, Chicago, IL 60637 (United States); Meakin, Casey A.; Truran, James W. [Joint Institute for Nuclear Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Lamb, Don Q. [Center for Astrophysical Thermonuclear Flashes, University of Chicago, Chicago, IL 60637 (United States)

2009-07-20T23:59:59.000Z

284

SN 2003du: Signatures of the Circumstellar Environment in a Normal Type Ia Supernova?  

E-Print Network [OSTI]

We present observations of the Type Ia supernova 2003du and report the detectionof an unusual, high-velocity component in the Ca II infrared triplet, similar tofeatures previously observed in SN 2000cx and SN 2001el. This feature exhibits a large expansion velocity (~18,000 km/s) which is nearly constant between -7 and +2 days relative to maximum light, and disappears shortly thereafter. Otherthan this feature, the spectral evolution and light curve resemble those of a normal SN Ia. We find that the Ca II feature can plausibly be caused by a dense shell formed when circumstellar material of solar abundance is overrun by the rapidly expanding outermost layers of the SN ejecta. Model calculations show that the optical and infrared spectra are remarkably unaffected by the circumstellar interaction. In particular, no hydrogen lines are detectable in either absorption or emission. The only qualitatively different features are the strong, high-velocity feature in the Ca II IR-triplet, and a somewhat weaker O I feature near 7,300 AA. The morphology and time evolution of these features provide an estimate for the amount of accumulated matter and an indication of the mixing in the dense shell. We apply these diagnostic tools to SN 2003du and infer that about 2 x 10^{-2} M_sun of solar abundance material may have accumulated in a circumstellar shell prior to the observations. Furthermore, the early light curve data imply that the circumstellar material was originally very close to the progenitor system, perhaps from an accretion disk, Roche lobe or common envelope.

C. L. Gerardy; P. Hoeflich; R. A. Fesen; G. H. Marion; K. Nomoto; R. Quimby; B. E. Schaefer; L. Wang; J. C. Wheeler

2003-09-23T23:59:59.000Z

285

Sensitivity study of explosive nucleosynthesis in Type Ia supernovae: I. Modification of individual thermonuclear reaction rates  

E-Print Network [OSTI]

We explore the sensitivity of the nucleosynthesis due to type Ia supernovae with respect to uncertainties in nuclear reaction rates. We have adopted a standard one-dimensional delayed detonation model of the explosion of a Chandrasekhar-mass white dwarf, and have post-processed the thermodynamic trajectories of every mass-shell with a nucleosynthetic code, with increases (decreases) by a factor of ten on the rates of 1196 nuclear reactions. We have computed as well hydrodynamic models for different rates of the fusion reactions of 12C and of 16O. For selected reactions, we have recomputed the nucleosynthesis with alternative prescriptions for their rates taken from the JINA REACLIB database, and have analyzed the temperature ranges where modifications of their rates have the strongest effect on nucleosynthesis. The nucleosynthesis resulting from the Type Ia supernova models is quite robust with respect to variations of nuclear reaction rates, with the exception of the reaction of fusion of 12C nuclei. The energy of the explosion changes by less than \\sim4%. The changes in the nucleosynthesis due to the modification of the rates of fusion reactions are as well quite modest, for instance no species with a mass fraction larger than 0.02 experiences a variation of its yield larger than a factor of two. We provide the sensitivity of the yields of the most abundant species with respect to the rates of the most intense reactions with protons, neutrons, and alphas. In general, the yields of Fe-group nuclei are more robust than the yields of intermediate-mass elements. Among the charged particle reactions, the most influential on supernova nucleosynthesis are 30Si + p \\rightleftarrows 31P + {\\gamma}, 20Ne + {\\alpha} \\rightleftarrows 24Mg + {\\gamma}, and 24Mg + {\\alpha} \\rightleftarrows 27Al + p. The temperatures at which a modification of their rate has a larger impact are in the range 2 < T < 4 GK. (abridged)

Eduardo Bravo; Gabriel Martnez-Pinedo

2012-04-09T23:59:59.000Z

286

Incompatibility of a comoving Ly-alpha forest with supernova-Ia luminosity distances  

E-Print Network [OSTI]

Recently Perlmutter et al. suggested a positive value of Einstein's cosmological constant Lambda on the basis of luminosity distances from type-Ia supernovae. However, Lambda world models had earlier been proposed by Hoell & Priester and Liebscher et al. on the basis of quasar absorption-line data. Employing more general repulsive fluids ("dark energy") encompassing the Lambda component we quantitatively compare both approaches with each other. Fitting the SN-data by a minimum-component model consisting of dark energy + dust yields a closed universe with a large amount of dust exceeding the baryonic content constrained by big-bang nucleosynthesis. The nature of the dark energy is hardly constrained. Only when enforcing a flat universe there is a clear tendency to a dark-energy Lambda fluid and the `canonical' value Omega_M = 0.3 for dust. Conversely, fitting the quasar-data by a minimum-component model yields a sharply defined, slightly closed model with a low dust density ruling out significant pressureless dark matter. The dark-energy component obtains an equation-of-state P = -0.96 epsilon close to that of a Lambda-fluid. Omega_M = 0.3 or a precisely flat spatial geometry are inconsistent with minimum-component models. It is found that quasar and supernova data sets cannot be reconciled with each other via (repulsive ideal fluid+dust+radiation)-world models. Compatibility could be reached by drastic expansion of the parameter space with at least two exotic fluids added to dust and radiation as world constituents. If considering such solutions as far-fetched one has to conclude that the quasar absorption line and the SN-Ia constraints are incompatible.

Jens Thomas; Hartmut Schulz

2001-03-18T23:59:59.000Z

287

Carrier capture dynamics of single InGaAs/GaAs quantum-dot layers  

SciTech Connect (OSTI)

Using 800 nm, 25-fs pulses from a mode locked Ti:Al{sub 2}O{sub 3} laser, we have measured the ultrafast optical reflectivity of MBE-grown, single-layer In{sub 0.4}Ga{sub 0.6}As/GaAs quantum-dot (QD) samples. The QDs are formed via two-stage Stranski-Krastanov growth: following initial InGaAs deposition at a relatively low temperature, self assembly of the QDs occurs during a subsequent higher temperature anneal. The capture times for free carriers excited in the surrounding GaAs (barrier layer) are as short as 140 fs, indicating capture efficiencies for the InGaAs quantum layer approaching 1. The capture rates are positively correlated with initial InGaAs thickness and annealing temperature. With increasing excited carrier density, the capture rate decreases; this slowing of the dynamics is attributed to Pauli state blocking within the InGaAs quantum layer.

Chauhan, K. N.; Riffe, D. M.; Everett, E. A.; Kim, D. J.; Yang, H. [Physics Department, Utah State University, Logan, Utah 84322-4415 (United States)] [Physics Department, Utah State University, Logan, Utah 84322-4415 (United States); Shen, F. K. [Center for Surface Analysis and Applications, Utah State University, Logan, Utah 84322-4415 (United States)] [Center for Surface Analysis and Applications, Utah State University, Logan, Utah 84322-4415 (United States)

2013-05-28T23:59:59.000Z

288

GA-AL-SC | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

GA-AL-SC GA-AL-SC GA-AL-SC October 1, 2012 ALA-1-N Wholesale Power Rate Schedule Area: PowerSouth Energy Cooperative System: Georgia-Alabama-South Carolina October 1, 2012 Duke-1-E Wholesale Power Rate Schedule Area: Duke On-System System: Georgia-Alabama-South Carolina October 1, 2012 Duke-2-E Wholesale Power Rate Schedule Area: Central System: Georgia-Alabama-South Carolina October 1, 2012 Duke-3-E Wholesale Power Rate Schedule Area: None System: Georgia-Alabama-South Carolina October 1, 2012 Duke-4-E Wholesale Power Rate Schedule Area: Duke Self-Schedulers System: Georgia-Alabama-South Carolina October 1, 2012 MISS-1-N Wholesale Power Rate Schedule Area: South Mississippi Electric Power Association System: Georgia-Alabama-South Carolina October 1, 2012 Pump-1-A Wholesale Power Rate Schedule

289

Low Efficiency Droop Green Nano-Pyramid {10 -11} InGaN/GaN Multiple Quantum Well LED  

Science Journals Connector (OSTI)

We report a low efficiency droop 520 nm green nano-pyramid InGaN/GaN multiple quantum well (MQW) LED. MQWs were grown on the semipolar {10 1} nano-pyramid facets. The device physics...

Cheng, Yuh-Jen; Chang, Shih-Pang; Lin, Da-Wei; Kuo, Hao-chung; Xiong, Kang-lin

290

InGaN working electrodes with assisted bias generated from GaAs solar cells for efficient water splitting  

Science Journals Connector (OSTI)

Hydrogen generation through water splitting by n-InGaN working electrodes with bias generated from GaAs solar cell was studied. Instead of using an external bias provided by power...

Liu, Shu-Yen; Sheu, J K; Lin, Yu-Chuan; Chen, Yu-Tong; Tu, S J; Lee, M L; Lai, W C

2013-01-01T23:59:59.000Z

291

Reaktive Molekularstrahlepitaxie und Charakterisierung von GaN/(Al,Ga)N-Heterostrukturen auf SiC(0001).  

E-Print Network [OSTI]

??Thema dieser Arbeit ist die Synthese von hexagonalen GaN/(Al,Ga)N-Heterostrukturen mittels reaktiver Molekularstrahlepitaxie (MBE) auf SiC(0001)-Substraten. Der Einflu der Wachstumsbedingungen auf die strukturellen, morphologischen, optischen und (more)

Thamm, Andreas

2001-01-01T23:59:59.000Z

292

HELIUM-IGNITED VIOLENT MERGERS AS A UNIFIED MODEL FOR NORMAL AND RAPIDLY DECLINING TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

The progenitors of Type Ia supernovae (SNe Ia) are still unknown, despite significant progress during the past several years in theory and observations. Violent mergers of two carbon-oxygen (CO) white dwarfs (WDs) are a candidate scenario suggested to be responsible for at least a significant fraction of normal SNe Ia. Here, we simulate the merger of two CO WDs using a moving-mesh code that allows for the inclusion of thin helium (He) shells (0.01 M{sub Sun }) on top of the WDs at an unprecedented numerical resolution. The accretion of He onto the primary WD leads to the formation of a detonation in its He shell. This detonation propagates around the CO WD and sends a converging shock wave into its core, known to robustly trigger a second detonation, as in the well-known double-detonation scenario for He-accreting CO WDs. However, in contrast to that scenario where a massive He shell is required to form a detonation through thermal instability, here the He detonation is ignited dynamically. Accordingly the required He-shell mass is significantly smaller, and hence its burning products are unlikely to affect the optical display of the explosion. We show that this scenario, which works for CO primary WDs with CO- as well as He-WD companions, has the potential to explain the different brightness distributions, delay times, and relative rates of normal and fast declining SNe Ia. Finally, we discuss extensions to our unified merger model needed to obtain a comprehensive picture of the full observed diversity of SNe Ia.

Pakmor, R.; Springel, V. [Heidelberger Institut fuer Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg (Germany); Kromer, M. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Taubenberger, S. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

2013-06-10T23:59:59.000Z

293

Nucleation and Growth of GaN on GaAs (001) Substrates  

SciTech Connect (OSTI)

The nucleation of GaN thin films on GaAs is investigated for growth at 620 "C. An rf plasma cell is used to generate chemically active nitrogen from N2. An arsenic flux is used in the first eight monolayer of nitride growth to enhance nucleation of the cubic phase. Subsequent growth does not require an As flux to preserve the cubic phase. The nucleation of smooth interfaces and GaN films with low stacking fault densities is dependent upon relative concentrations of active nitrogen species in the plasma and on the nitrogen to gallium flux ratio.

Drummond, Timothy J.; Hafich, Michael J.; Heller, Edwin J.; Lee, Stephen R.; Liliental-Weber, Zuzanna; Ruvimov, Sergei; Sullivan, John P.

1999-05-03T23:59:59.000Z

294

Lattice-Mismatched GaAs/InGaAs Two-Junction Solar Cells by Direct Wafer Bonding  

SciTech Connect (OSTI)

Direct bonded interconnect between subcells of a lattice-mismatched III-V compound multijunction cell would enable dislocation-free active regions by confining the defect network needed for lattice mismatch accommodation to tunnel junction interfaces, while metamorphic growth inevitably results in less design flexibility and lower material quality than is desirable. The first direct-bond interconnected multijunction solar cell, a two-terminal monolithic GaAs/InGaAs two-junction solar cell, is reported and demonstrates viability of direct wafer bonding for solar cell applications. The tandem cell open-circuit voltage was approximately the sum of the subcell open-circuit voltages. This achievement shows direct bonding enables us to construct lattice-mismatched III-V multijunction solar cells and is extensible to an ultrahigh efficiency InGaP/GaAs/InGaAsP/InGaAs four-junction cell by bonding a GaAs-based lattice-matched InGaP/GaAs subcell and an InP-based lattice-matched InGaAsP/InGaAs subcell. The interfacial resistance experimentally obtained for bonded GaAs/InP smaller than 0.10 Ohm-cm{sup 2} would result in a negligible decrease in overall cell efficiency of {approx}0.02%, under 1-sun illumination.

Tanabe, K.; Aiken, D. J.; Wanlass, M. W.; Morral, A. F.; Atwater, H. A.

2006-01-01T23:59:59.000Z

295

Growth and characterization of M-plane GaN and (In,Ga)N/GaN multiple quantum wells.  

E-Print Network [OSTI]

??Thema dieser Arbeit ist die Synthese von Wurtzit M-plane (In,Ga)N(1-100)-Heterostrukturen auf g-LiAlO2(100) mittels plasmauntersttzter Molekularstrahlepitaxie (MBE). Der Einflu der Wachstumsbedingungen auf die strukturellen, morphologischen, und (more)

Sun, Yue-Jun

2004-01-01T23:59:59.000Z

296

Development of Polarized Electron Source of GaAs-AlGaAs Superlattice and Strained GaAs  

Science Journals Connector (OSTI)

At Nagoya University, we have continued the development of GaAs polarized electron source (PES) for several years. Our test ... a gun producing (15) KeV polarized electrons and a standard 100 KeV Mott polarimete...

T. Nakanishi; S. Nakamura

1991-01-01T23:59:59.000Z

297

New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy  

E-Print Network [OSTI]

We have discovered 21 new Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to trace the history of cosmic expansion over the last 10 billion years. These objects, which include 13 spectroscopically confirmed SNe Ia at z > 1, were discovered during 14 epochs of reimaging of the GOODS fields North and South over two years with the Advanced Camera for Surveys on HST. Together with a recalibration of our previous HST-discovered SNe Ia, the full sample of 23 SNe Ia at z > 1 provides the highest-redshift sample known. Combined with previous SN Ia datasets, we measured H(z) at discrete, uncorrelated epochs, reducing the uncertainty of H(z>1) from 50% to under 20%, strengthening the evidence for a cosmic jerk--the transition from deceleration in the past to acceleration in the present. The unique leverage of the HST high-redshift SNe Ia provides the first meaningful constraint on the dark energy equation-of-state parameter at z >1. The result remains consistent with a cosmological constant (w(z)=-1), and rules out rapidly evolving dark energy (dw/dz >>1). The defining property of dark energy, its negative pressure, appears to be present at z>1, in the epoch preceding acceleration, with ~98% confidence in our primary fit. Moreover, the z>1 sample-averaged spectral energy distribution is consistent with that of the typical SN Ia over the last 10 Gyr, indicating that any spectral evolution of the properties of SNe Ia with redshift is still below our detection threshold.

Adam G. Riess; Louis-Gregory Strolger; Stefano Casertano; Henry C. Ferguson; Bahram Mobasher; Ben Gold; Peter J. Challis; Alexei V. Filippenko; Saurabh Jha; Weidong Li; John Tonry; Ryan Foley; Robert P. Kirshner; Mark Dickinson; Emily MacDonald; Daniel Eisenstein; Mario Livio; Josh Younger; Chun Xu; Tomas Dahlen; Daniel Stern

2006-11-17T23:59:59.000Z

298

Auger recombination suppression and band alignment in GaAsBi/GaAs heterostructures  

SciTech Connect (OSTI)

Using a combination of experimental and theoretical techniques we present the dependence of the bandgap E{sub g} and the spin orbit splitting energy ?{sub so}, with Bi concentration in GaAsBi/GaAs samples. We find that the concentration at which ?{sub so},> E{sub g} occurs at 9%. Both spectroscopic as well as first device results indicate a type I alignment.

Hild, K.; Batool, Z.; Jin, S. R.; Hossain, N.; Marko, I. P.; Sweeney, S. J. [Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Hosea, T. JC. [1 Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, GU2 7XH, UK and also, Ibnu Sina Institute, Universiti Teknologi Malaysia, Johor Bahru, 81310 (Malaysia); Lu, X. [Department of Electrical and Computer Engineering, University of Victoria, Victoria BC, V8W 3P6, Canada and now VarianSemiconductor Equipment Associates, Gloucester, MA 01930 (United States); Tiedje, T. [Department of Electrical and Computer Engineering, University of Victoria, Victoria BC, V8W 3P6 (Canada)

2013-12-04T23:59:59.000Z

299

Recent progress in InGaAsSb/GaSb TPV devices  

SciTech Connect (OSTI)

AstroPower is developing InGaAsSb thermophotovoltaic (TPV) devices. This photovoltaic cell is a two-layer epitaxial InGaAsSb structure formed by liquid-phase epitaxy on a GaSb substrate. The (direct) bandgap of the In{sub 1{minus}x}Ga{sub x}As{sub 1{minus}y}Sb{sub y} alloy is 0.50 to 0.55 eV, depending on its exact alloy composition (x,y); and is closely lattice-matched to the GaSb substrate. The use of the quaternary alloy, as opposed to a ternary alloy--such as, for example InGaAs/InP--permits low bandgap devices optimized for 1,000 to 1,500 C thermal sources with, at the same time, near-exact lattice matching to the GaSb substrate. Lattice matching is important since even a small degree of lattice mismatch degrades device performance and reliability and increases processing complexity. Internal quantum efficiencies as high as 95% have been measured at a wavelength of 2 microns. At 1 micron wavelengths, internal quantum efficiencies of 55% have been observed. The open-circuit voltage at currents of 0.3 A/cm{sup 2} is 0.220 volts and 0.280 V for current densities of 2 A/cm{sup 2}. Fill factors of 56% have been measured at 60 mA/cm{sup 2}. However, as current density increases there is some decrease in fill factor. The results to date show that the GaSb-based quaternary compounds provide a viable and high performance energy conversion solution for thermophotovoltaic systems operating with 1,000 to 1,500 C source temperatures.

Shellenbarger, Z.A.; Mauk, M.G.; DiNetta, L.C. [AstroPower, Inc., Newark, DE (United States); Charache, G.W. [Lockheed Martin Corp., Schenectady, NY (United States)

1996-05-01T23:59:59.000Z

300

Radio-frequency reflectometry on an undoped AlGaAs/GaAs single electron transistor  

SciTech Connect (OSTI)

Radio frequency reflectometry is demonstrated in a sub-micron undoped AlGaAs/GaAs device. Undoped single electron transistors (SETs) are attractive candidates to study single electron phenomena, due to their charge stability and robust electronic properties after thermal cycling. However, these devices require a large top-gate, which is unsuitable for the fast and sensitive radio frequency reflectometry technique. Here, we demonstrate that rf reflectometry is possible in an undoped SET.

MacLeod, S. J.; See, A. M.; Keane, Z. K.; Scriven, P.; Micolich, A. P.; Hamilton, A. R., E-mail: Alex.Hamilton@unsw.edu.au [School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Aagesen, M.; Lindelof, P. E. [Nanoscience Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)] [Nanoscience Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)

2014-01-06T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

LBNL-4183E-rev1 N NA AT TU UR RA AL L G GA AS S V VA AR RI  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

4183E-rev1 4183E-rev1 N NA AT TU UR RA AL L G GA AS S V VA AR RI IA AB BI IL LI IT TY Y I IN N C CA AL LI IF FO OR RN NI IA A: : E EN NV VI IR RO ON NM ME EN NT TA AL L I IM MP PA AC CT TS S A AN ND D D DE EV VI IC CE E P PE ER RF FO OR RM MA AN NC CE E E EX XP PE ER RI IM ME EN NT TA AL L E EV VA AL LU UA AT TI IO ON N O OF F I IN NS ST TA AL LL LE ED D C CO OO OK KI IN NG G E EX XH HA AU US ST T F FA AN N P PE ER RF FO OR RM MA AN NC CE E Brett C. Singer, William W. Delp and Michael G. Apte Indoor Environment Department Atmospheric Sciences Department Environmental Energy Technologies Division July 2011 (Revised February 2012) Disclaimer 1 This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of

302

Multiband GaNAsP Quaternary Alloys  

SciTech Connect (OSTI)

We have synthesized GaN{sub x}As{sub 1-y}P{sub y} alloys (x {approx} 0.3-1% and y = 0-0.4) using nitrogen N ion implantation into GaAsP epilayers followed by pulsed laser melting and rapid thermal annealing techniques. As predicted by the band anticrossing model, the incorporation of N splits the conduction band (E{sub M}) of the GaAs{sub 1-y}P{sub y} substrate, and strong optical transitions from the valence band to the lower (E{sub -}) and upper (E{sub +}) conduction subbands are observed. The relative strengths of the E{sub -} and E{sub +} transition change as the localized N level E{sub N} emerges from the conduction band forming narrow intermediate band for y > 0.3. The results show that GaN{sub x}As{sub 1-x-y}P{sub y} alloys with y > 0.3 is a three band semiconductor alloy with potential applications for high-efficiency intermediate band solar cells.

Yu, K.M.; Walukiewicz, W.; Ager III, J.W.; Bour, D.; Farshchi,R.; Dubon, O.D.; Li, S.X.; Sharp, I.D.; Haller, E.E.

2005-12-08T23:59:59.000Z

303

Implantation of carbon in GaAs  

SciTech Connect (OSTI)

Carbon implanted into GaAs and thermally annealed typically exhibits very low (<3%) electrical activity. It has been demonstrated that the electrical activity of C can be significantly enhanced by co-implantation with Ga. Improved activation may result from either additional damage of the crystal lattice or from stoichiometric changes, forcing the C atoms onto As sites. To determine the relative importance of each of these effects, I have undertaken a systematic study of carbon activation in GaAs. A range of co-implants have been used: group III (B, Ga), group V (N, P, As) and noble gases (Ar, Kr). The damage introduced to the substrate will depend on the mass of the ion implanted. The group III and group V co-implants will affect the crystal stoichiometry. The results indicate that both lattice damage and crystal stoichiometry are important for high electrical activity of C. Increasing the damage will increase the activation due to the increased number of As vacancies but maximum activation can be obtained only by a co-implant which not only damages the lattice but also forces the C to occupy an As site.

Moll, A.J.

1992-03-01T23:59:59.000Z

304

O?[]O? nuclear ?-decay of ?Ga  

E-Print Network [OSTI]

The branching ratio for the ?-Decay of ?Ga to the first excited O? state in ?Zn has been measured. It is possible to use this branching ratio to test the theoretical method of calculating the [] component of the charge correction term [], which...

Hyman, Bruce Carl

2012-06-07T23:59:59.000Z

305

Nano-scale characterization of GaAsP/GaAs strained superlattice structure by nano-beam electron diffraction  

SciTech Connect (OSTI)

Distribution of lattice strain in a GaAsP/GaAs superlattice with a periodicity of 10?nm thickness, deposited on a 100?nm GaAs basal layer has been measured by nano-beam electron diffraction. The superlattice on the (001) plane of the basal GaAs layer shows a constant lattice strain from the bottom to the top layers, whereas the superlattice on the basal GaAs surface sloped by 16 from the (001) plane shows a variation of the lattice strain and crystal orientation. The difference of the strain distributions was discussed from the viewpoint of average strain. This tilt was explained by an atomistic model.

Jin, Xiuguang [Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Nakahara, Hirotaka [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Saitoh, Koh; Tanaka, Nobuo [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Takeda, Yoshikazu [Nagoya Industrial Science Research Institute, Nagoya 464-0819 (Japan); Aichi Synchrotron Radiation Center, Aichi Science and Technology Foundation, Seto 489-0965 (Japan)

2014-03-17T23:59:59.000Z

306

Chemical beam epitaxy growth of AlGaAs/GaAs tunnel junctions using trimethyl aluminium for multijunction solar cells  

SciTech Connect (OSTI)

AlGaAs/GaAs tunnel junctions for use in high concentration multijunction solar cells were designed and grown by chemical beam epitaxy (CBE) using trimethyl aluminium (TMA) as the p-dopant source for the AlGaAs active layer. Controlled hole concentration up to 4?10{sup 20} cm{sup ?3} was achieved through variation in growth parameters. Fabricated tunnel junctions have a peak tunneling current up to 6140 A/cm{sup 2}. These are suitable for high concentration use and outperform GaAs/GaAs tunnel junctions.

Paquette, B.; DeVita, M.; Turala, A.; Kolhatkar, G.; Boucherif, A.; Jaouad, A.; Aimez, V.; Ars, R. [Institut Interdisciplinaire d'Innovation Technologique (3IT), Universit de Sherbrooke, Sherbrooke, Qubec (Canada)] [Institut Interdisciplinaire d'Innovation Technologique (3IT), Universit de Sherbrooke, Sherbrooke, Qubec (Canada); Wilkins, M.; Wheeldon, J. F.; Walker, A. W.; Hinzer, K. [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada)] [Centre for Research in Photonics, University of Ottawa, Ottawa, ON (Canada); Fafard, S. [Cyrium Technologies Inc., Ottawa, ON (Canada)] [Cyrium Technologies Inc., Ottawa, ON (Canada)

2013-09-27T23:59:59.000Z

307

Electron tunneling spectroscopy study of electrically active traps in AlGaN/GaN high electron mobility transistors  

SciTech Connect (OSTI)

We investigate the energy levels of electron traps in AlGaN/GaN high electron mobility transistors by the use of electron tunneling spectroscopy. Detailed analysis of a typical spectrum, obtained in a wide gate bias range and with both bias polarities, suggests the existence of electron traps both in the bulk of AlGaN and at the AlGaN/GaN interface. The energy levels of the electron traps have been determined to lie within a 0.5?eV band below the conduction band minimum of AlGaN, and there is strong evidence suggesting that these traps contribute to Frenkel-Poole conduction through the AlGaN barrier.

Yang, Jie, E-mail: jie.yang@yale.edu; Cui, Sharon; Ma, T. P. [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States)] [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States); Hung, Ting-Hsiang; Nath, Digbijoy; Krishnamoorthy, Sriram; Rajan, Siddharth [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2013-11-25T23:59:59.000Z

308

CP Tech Center I Iowa State University I 2711 S. Loop Dr. Suite 4700,Ames, IA 50010-8664 I 515-294-5798 FOR MORE INFORMATION  

E-Print Network [OSTI]

CP Tech Center I Iowa State University I 2711 S. Loop Dr. Suite 4700,Ames, IA 50010-8664 I 515 calcium sulfate in the form of hemihydrate (plaster) in the cement (false set) or the uncontrolled early

309

??eia e e et ??? oa0 to 3i5ontinBoB5 PieeFi5e Hinea tiTiUation ...  

E-Print Network [OSTI]

PieeFi5e Hinea tiTiUation. I.R. de Farias JR., M. ?hao, and H. ?hao. State University of New York at jumalo. {defariasy m|haoy |hon??ia}@??ffalo.ed?.

310

LAX XXlCfl jX?iK, Idd+?KYLViG?IA  

Office of Legacy Management (LM)

f f , : I~&l, samtier cipwati8Aa CffUm - . Jiux.lCJ d,# 1754 - - _- - .- t :; . Jesse e. ahizmn*~*ter -2.' -------- - _ &tV' hi@A l f izau Bkteriala ;' . . 1 -7 I _' i' . Fpr&G& r&Q Q,&& fu &fI& L;&& -l&d 2;,i' iI,;/Qi' rIGN CQ&GgJy p;E& p;~p>gyf LAX XXlCfl jX?iK, Idd+?KYLViG?IA i-icfer~~o is &o ta yaw rwarandu3;: l P iimwmbec L?, 1953, reque&in~ a d&q.&ti of khority tA A&sister prog= for th+zz developmrrrl, Ii-&k& & acyui8itti ef c;uYletit*type and reswitlitc-type urtim bi:aPing eres and far t3-u jx*uctim and acquisitian 6f W ;aniU CCm- csa:ratc~ fhzi awes wit2n Lhe Six&e of Pemlsyzvania. 1 da not b&i- the projscrt fmr the pkcch2670 +S eroa from i&d.&

311

Direct numerical simulations of type Ia supernovae flames I: The landau-darrieus instability  

SciTech Connect (OSTI)

Planar flames are intrinsically unstable in open domains due to the thermal expansion across the burning front--the Landau-Darrieus instability. This instability leads to wrinkling and growth of the flame surface, and corresponding acceleration of the flame, until it is stabilized by cusp formation. We look at the Landau-Darrieus in stability for C/O thermonuclear flames at conditions relevant to the late stages of a Type Ia supernova explosion. Two-dimensional direct numerical simulations of both single-mode and multi-mode perturbations using a low Mach number hydrodynamics code are presented. We show the effect of the instability on the flame speed as a function of both the density and domain size, demonstrate the existence of the small scale cutoff to the growth of the instability, and look for the proposed breakdown of the non-linear stabilization at low densities. The effects of curvature on the flame as quantified through measurements of the growth rate and computation of the corresponding Markstein number. While accelerations of a few percent are observed, they are too small to have any direct outcome on the supernova explosion.

Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

2003-11-24T23:59:59.000Z

312

Thermonuclear .Ia Supernovae from Helium Shell Detonations: Explosion Models and Observables  

Science Journals Connector (OSTI)

During the early evolution of an AM Canum Venaticorum system, helium is accreted onto the surface of a white dwarf under conditions suitable for unstable thermonuclear ignition. The turbulent motions induced by the convective burning phase in the He envelope become strong enough to influence the propagation of burning fronts and may result in the onset of a detonation. Such an outcome would yield radioactive isotopes and a faint rapidly rising thermonuclear ".Ia" supernova. In this paper, we present hydrodynamic explosion models and observable outcomes of these He shell detonations for a range of initial core and envelope masses. The peak UVOIR bolometric luminosities range by a factor of 10 (from 5 ? 1041 to 5 ? 1042 erg s1), and the R-band peak varies from M R,peak = 15 to 18. The rise times in all bands are very rapid (40Ca through 56Ni) and unburnt He. Thus, the spectra around peak light lack signs of intermediate-mass elements and are dominated by CaII and TiII features, with the caveat that our radiative transfer code does not include the nonthermal effects necessary to produce He features.

Ken J. Shen; Dan Kasen; Nevin N. Weinberg; Lars Bildsten; Evan Scannapieco

2010-01-01T23:59:59.000Z

313

Comparison of the Legacy and Gold SnIa Dataset Constraints on Dark Energy Models  

E-Print Network [OSTI]

We have performed a comparative analysis of three recent and reliable SnIa datasets available in the literature: the Full Gold (FG) dataset (157 data points $0dataset (140 data points $0dataset (115 data points $0datasets are consistent with each other at the 95% confidence level, the latest (SNLS) dataset shows distinct trends which are not shared by the Gold datasets. We find that the best fit dynamical $w(z)$ obtained from the SNLS dataset does not cross the PDL $w=-1$ and remains above and close to the $w=-1$ line for the whole redshift range $0datasets (FG and TG) clearly crosses the PDL and departs significantly from the PDL $w=-1$ line while the LCDM parameter values are about $2\\sigma$ away from the best fit $w(z)$. In addition, the $(\\Omega_{0m},\\Omega_\\Lambda)$ parameters in a LCDM parametrization without a flat prior, fit by the SNLS dataset, favor the minimal flat LCDM concordance model. The corresponding fit with the Gold datasets mildly favors a closed universe and the flat LCDM parameter values are $1\\sigma - 2\\sigma$ away from the best fit $(\\Omega_{0m},\\Omega_\\Lambda)$.

S. Nesseris; L. Perivolaropoulos

2005-12-02T23:59:59.000Z

314

Phenomenology for Supernova Ia Data Based on a New Cosmic Time  

E-Print Network [OSTI]

A new phenomenological theory for the expansion of our universe is presented. Because fundamental supporting theory is still in development, its discussion is not presented in this paper. The theory is based on a new algebraic expression for cosmic time G Rho t^2=3/32Pi, which correctly predicts the WMAP measured cosmological constants and the fundamental Hubble parameter H(t) for the expansion of the universe. A replacement for dark matter, called here "dark mass", is proposed which scales as with the expansion and incorporated. It does not react with ordinary matter, except gravitationally, and produces flat rotational curves for spiral galaxies. Also a new expression for the approaching velocity of radiation in a closed 3-sphere expanding universe is given that accounts for the early degrading negative approach of radiation for z > 1.7. The expression is v = Hr-c. Combining these three elements produces a luminosity distance dL that successfully predicts the apparent magnitude of exploding supernova Ia stars and even the new gamma ray bursts with no need for dark energy or acceleration of the expansion of the universe.

Charles B. Leffert

2007-07-26T23:59:59.000Z

315

Evaluating Systematic Dependencies of Type Ia Supernovae: The Influence of Deflagration to Detonation Density  

E-Print Network [OSTI]

We explore the effects of the deflagration to detonation transition (DDT) density on the production of Ni-56 in thermonuclear supernova explosions (type Ia supernovae). Within the DDT paradigm, the transition density sets the amount of expansion during the deflagration phase of the explosion and therefore the amount of nuclear statistical equilibrium (NSE) material produced. We employ a theoretical framework for a well-controlled statistical study of two-dimensional simulations of thermonuclear supernovae with randomized initial conditions that can, with a particular choice of transition density, produce a similar average and range of Ni-56 masses to those inferred from observations. Within this framework, we utilize a more realistic "simmered" white dwarf progenitor model with a flame model and energetics scheme to calculate the amount of Ni-56 and NSE material synthesized for a suite of simulated explosions in which the transition density is varied in the range 1-3x10^7 g/cc. We find a quadratic dependence ...

Jackson, Aaron P; Townsley, Dean M; Chamulak, David A; Brown, Edward F; Timmes, F X

2010-01-01T23:59:59.000Z

316

A Test of Tully-Fisher Distance Estimates Using Cepheids and Type Ia Supernovae  

E-Print Network [OSTI]

We update and extend the results of Shanks (1997, MNRAS, 290, L77) by making a direct test of Tully-Fisher distance estimates to thirteen spiral galaxies with HST Cepheid distances and to ten spiral galaxies with Type Ia supernova (SNIa) distances. The results show that the Tully-Fisher distance moduli are too short with respect to the Cepheid distances by 0.46+-0.11mag and too short with respect to the SNIa distances by 0.49+-0.18mag. Combining the HST Cepheid and the best SNIa data suggests that, overall, previous Tully-Fisher distances at v~1000 kms-1 were too short by 0.43+-0.09mag, a result which is significant at the 4.6 sigma level. These data therefore indicate that previous Tully-Fisher distances should be revised upwards by 22+-5% implying, for example, a Virgo distance of 19.0+-1.8Mpc. The value of Ho from Tully-Fisher estimates is correspondingly revised downwards from Ho=84+-10kms-1Mpc-1 to Ho=69+-8kms-1Mpc-1. There is evidence that the Tully-Fisher relation at large distances is affected by Malmquist bias. In this case, we argue that Ho<50kms-1Mpc-1 cannot be ruled out by Tully-Fisher considerations.

T. Shanks

1999-01-24T23:59:59.000Z

317

Parametrizing the transition to the phantom epoch with Supernovae Ia and Standard Rulers  

E-Print Network [OSTI]

The reconstruction of a (non)canonical scalar field Lagrangian from the dark energy Equation of State (EoS) parameter is studied, where it is shown that any EoS parametrization can be well reconstructed in terms of scalar fields. Several examples of EoS parameters are studied and the particular scalar field Lagrangian is reconstructed. Then, we propose some new parametrizations that may present a (fast) transition to a phantom dark energy EoS (where $w_{DE}dark energy EoS are studied by using supernovae Ia data (HST Cluster Supernova Survey) combined with Standard Ruler datasets [Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO)] and its comparison with the $\\Lambda$CDM model is analyzed. Then, the best fit of the models is obtained, which provides some information about whether a phantom transition may be supported by the observations. In this regard, the crossing of the phantom barrier is allowed statistically but the occurrence of a future singularity seems unlikely.

Iker Leanizbarrutia; Diego Sez-Gmez

2014-04-14T23:59:59.000Z

318

Infrared emission from the substrate of GaAs-based semiconductor lasers Mathias Ziegler,1,a  

E-Print Network [OSTI]

GaP single QW surrounded by AlGaInP waveguide WG and cladding layers, whereas the NIR laser incorporates a GaInfrared emission from the substrate of GaAs-based semiconductor lasers Mathias Ziegler,1,a Robert in GaAs-based broad-area laser diodes. Spectrally and spatially resolved scanning optical microscopy

Peinke, Joachim

319

A POSSIBLE EVOLUTIONARY SCENARIO OF HIGHLY MAGNETIZED SUPER-CHANDRASEKHAR WHITE DWARFS: PROGENITORS OF PECULIAR TYPE Ia SUPERNOVAE  

SciTech Connect (OSTI)

Several recently discovered peculiar Type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard Type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses {approx}2.1-2.8 M{sub Sun }, M{sub Sun} being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses have already been established as potential candidates for the progenitors of peculiar Type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here, we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens multiple possible evolution scenarios ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, such as the recent discovery of a large number of magnetized white dwarfs by the Sloan Digital Sky Survey.

Das, Upasana; Mukhopadhyay, Banibrata [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Rao, A. R., E-mail: upasana@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in, E-mail: arrao@tifr.res.in [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

2013-04-10T23:59:59.000Z

320

Type Ia Supernovae with Bi-Modal Explosions Are Common -- Possible Smoking Gun for Direct Collisions of White-Dwarfs  

E-Print Network [OSTI]

We discover clear doubly-peaked line profiles in 3 out of ~20 type Ia supernovae (SNe Ia) with high-quality nebular-phase spectra. The profiles are consistently present in three well-separated Co/Fe emission features. The two peaks are respectively blue-shifted and red-shifted relative to the host galaxies and are separated by ~5000 km/s. The doubly-peaked profiles directly reflect a bi-modal velocity distribution of the radioactive Ni56 in the ejecta that powers the emission of these SNe. Due to their random orientations, only a fraction of SNe with intrinsically bi-modal velocity distributions will appear as doubly-peaked spectra. Therefore SNe with intrinsic bi-modality are likely common, especially among the SNe in the low-luminosity (~40% of all SNe Ia) part on the Philips relation \\Delta m15(B) >~ 1.3. Bi-modality is naturally expected from direct collisions of white dwarfs (WDs) due to the detonation of both WDs and is demonstrated in a 3D 0.64 M_Sun-0.64 M_Sun WD collision simulation.

Dong, Subo; Kushnir, Doron; Prieto, Jose L

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Three-Dimensional Simulations of the Deflagration Phase of the Gravitationally Confined Detonation Model of Type Ia Supernovae  

E-Print Network [OSTI]

We report the results of a series of three-dimensional (3-D) simulations of the deflagration phase of the gravitationally confined detonation mechanism for Type Ia supernovae. In this mechanism, ignition occurs at one or several off-center points, resulting in a burning bubble of hot ash that rises rapidly, breaks through the surface of the star, and collides at a point opposite breakout on the stellar surface. We find that detonation conditions are robustly reached in our 3-D simulations for a range of initial conditions and resolutions. Detonation conditions are achieved as the result of an inwardly-directed jet that is produced by the compression of unburnt surface material when the surface flow collides with itself. A high-velocity outwardly-directed jet is also produced. The initial conditions explored in this paper lead to conditions at detonation that can be expected to produce large amounts of $^{56}$Ni and small amounts of intermediate mass elements. These particular simulations are therefore relevant only to high luminosity Type Ia supernovae. Recent observations of Type Ia supernovae imply a compositional structure that is qualitatively consistent with that expected from these simulations.

G C Jordan IV; R T Fisher; D M Townsley; A C Calder; C Graziani; S Asida; D Q Lamb; J W Truran

2007-03-21T23:59:59.000Z

322

The Joint Efficient Dark-energy Investigation (JEDI): Measuring the cosmic expansion history from type Ia supernovae  

E-Print Network [OSTI]

JEDI (Joint Efficient Dark-energy Investigation) is a candidate implementation of the NASA-DOE Joint Dark Energy Mission (JDEM). JEDI will probe dark energy in three independent methods: (1) type Ia supernovae, (2) baryon acoustic oscillations, and (3) weak gravitational lensing. In an accompanying paper, an overall summary of the JEDI mission is given. In this paper, we present further details of the supernova component of JEDI. To derive model-independent constraints on dark energy, it is important to precisely measure the cosmic expansion history, H(z), in continuous redshift bins from z \\~ 0-2 (the redshift range in which dark energy is important). SNe Ia at z > 1 are not readily accessible from the ground because the bulk of their light has shifted into the near-infrared where the sky background is overwhelming; hence a space mission is required to probe dark energy using SNe. Because of its unique near-infrared wavelength coverage (0.8-4.2 microns), JEDI has the advantage of observing SNe Ia in the rest frame J band for the entire redshift range of 0 energy are discussed, with special emphasis on the improved precision afforded by the rest frame near-infrared data.

M. M. Phillips; Peter Garnavich; Yun Wang; David Branch; Edward Baron; Arlin Crotts; J. Craig Wheeler; Edward Cheng; Mario Hamuy; for the JEDI Team

2006-06-28T23:59:59.000Z

323

Constraining the dark energy and smoothness parameter with typeIa supernovae and gamma-ray bursts  

Science Journals Connector (OSTI)

The existence of inhomogeneities in the observed Universe modifies the distance-redshift relations thereby affecting the results of cosmological tests in comparison to the ones derived assuming spatially uniform models. By modeling the inhomogeneities through a Zeldovich-Kantowski-Dyer-Roeder approach which is phenomenologically characterized by a smoothness parameter ?, we rediscuss the constraints on the cosmic parameters based on typeIa supernovae (SNeIa) and gamma-ray bursts (GRBs) data. The present analysis is restricted to a flat ?CDM model with the reasonable assumption that ? does not clump. A ?2 analysis using 557 SNeIa data from the Union2 compilation data (R. Amanullah et al., Astrophys. J. 716, 712 (2010).) constrains the pair of parameters (?m, ?) to ?m=0.27-0.03+0.08 (2?) and ??0.25. A similar analysis based only on 59 Hymnium GRBs (H. Wei, J. Cosmol. Astropart. Phys. 08 (2010) 020.) constrains the matter density parameter to be ?m=0.35-0.24+0.62 (2?) while all values for the smoothness parameter are allowed. By performing a joint analysis, it is found that ?m=0.27-0.03+0.06 and ??0.52. As a general result, although considering that current GRB data alone cannot constrain the smoothness ? parameter, our analysis provides an interesting cosmological probe for dark energy even in the presence of inhomogeneities.

V. C. Busti; R. C. Santos; J. A. S. Lima

2012-05-07T23:59:59.000Z

324

0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell  

SciTech Connect (OSTI)

We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

2006-01-01T23:59:59.000Z

325

Direct observation of Ga-rich microdomains in crack-free AlGaN grown on patterned GaNsapphire substrates  

E-Print Network [OSTI]

.e., a homogeneous aluminum content, is found near the sample surface. However, the strong rise of quantum efficiency for AlGaN because the Al alloys also nucleate on the mask materials. Recently, growth on patterned structured into a periodic grid of trenches and terraces along 1100 . Prior to the final AlGaN ( Al 0

Nabben, Reinhard

326

Monolithic integration of GaAs and h~~~~Ga~.~Aslasers by molecular epitaxy on GaAs  

E-Print Network [OSTI]

where the thick cladding layer below the active laser region acts as a buffer layer to-yield comparable epitaxial regrowth of Ino.aGaesAs lasers through dielectric masks between GaAs laser stripes on a GaAs substrate has been used for the -first time- to monolithically integrate these two lasers emitting near 1

327

Kohlenstoffhaltige ternre Verbindungen (V-Ge-C, Nb-Ga-C, Ta-Ga-C, Ta-Ge-C, Cr-Ga-C und Cr-Ge-C)  

Science Journals Connector (OSTI)

Die ternren Phasen V2GeC, Cr2GaC und Cr2GeC werden aus den Komponenten hergestellt und als H-Phasen identifiziert. Ferner drften auch die H-Phasen Ti2GaC, und Ti2GeC existieren. In gleicher Weise hergestellte L...

W. Jeitschko; H. Nowotny; F. Benesovsky

1963-01-01T23:59:59.000Z

328

Effect of AlGaN/GaN strained layer superlattice period on InGaN MQW laser diodes[Multiple Quantum Wells  

SciTech Connect (OSTI)

AlGaN/GaN strained layer superlattices have been employed in the cladding layers of InGaN multi-quantum well laser diodes grown by metalorganic chemical vapor deposition (MOCVD). Superlattices have been investigated for strain relief of the cladding layer, as well as an enhanced hole concentration, which is more than ten times the value obtained for bulk AlGaN films. Laser diodes with strained layer superlattices as cladding layers were shown to have superior structural and electrical properties compared to laser diodes with bulk AlGaN cladding layers. As the period of the strained layer superlattices is decreased, the threshold voltage, as well as the threshold current density, is decreased. The resistance to vertical conduction through p-type superlattices with increasing superlattice period is not offset by the increase in hole concentration for increasing superlattice spacing, resulting in higher voltages.

Hansen, M.; Abare, A.C.; Kozodoy, P.; Katona, T.M.; Craven, M.D.; Speck, J.S.; Mishra, U.K.; Coldren, L.A.; DenBaars, S.P.

2000-07-01T23:59:59.000Z

329

Radiation Hard AlGaN Detectors and Imager  

SciTech Connect (OSTI)

Radiation hardness of AlGaN photodiodes was tested using a 65 MeV proton beam with a total proton fluence of 3x10{sup 12} protons/cm{sup 2}. AlGaN Deep UV Photodiode have extremely high radiation hardness. These new devices have mission critical applications in high energy density physics (HEDP) and space explorations. These new devices satisfy radiation hardness requirements by NIF. NSTec is developing next generation AlGaN optoelectronics and imagers.

None

2012-05-01T23:59:59.000Z

330

Optimisation of doping cladding layers in AlGaInP/GaInP laser heterostructures  

SciTech Connect (OSTI)

The influence of cladding doping level on the characteristics of laser diodes, which are based on an AlGaInP/GaInP/GaAs system and emit at wavelengths of 670-680 nm, is studied. It is shown experimentally that, as the ratio of the cladding doping levels P/N increases, the inversion current density J{sub 0} and the differential gain {beta} also increase. A monotonic increase in the characteristic temperature T{sub 0} accompanies this process. The internal quantum yield {eta}{sub 0} of stimulated recombination has a maximum at P/N=2.1. Laser diodes with a mesastripe width of 100 {mu}m are manufactured. The cw radiation power emitted by them is as high as 1000 mW at an efficiency of 1.55 W A{sup -1}. (active media. lasers)

Chel'nyi, A A; Aluev, A V; Maslov, S V [M.F. Stel'makh Polyus Research and Development Institute, Moscow (Russian Federation)

2004-01-31T23:59:59.000Z

331

Graphene in ohmic contact for both n-GaN and p-GaN  

SciTech Connect (OSTI)

The wrinkles of single layer graphene contacted with either n-GaN or p-GaN were found both forming ohmic contacts investigated by conductive atomic force microscopy. The local IV results show that some of the graphene wrinkles act as high-conductive channels and exhibiting ohmic behaviors compared with the flat regions with Schottky characteristics. We have studied the effects of the graphene wrinkles using density-functional-theory calculations. It is found that the standing and folded wrinkles with zigzag or armchair directions have a tendency to decrease or increase the local work function, respectively, pushing the local Fermi level towards n- or p-type GaN and thus improving the transport properties. These results can benefit recent topical researches and applications for graphene as electrode material integrated in various semiconductor devices.

Zhong, Haijian; Liu, Zhenghui; Shi, Lin; Xu, Gengzhao; Fan, Yingmin; Huang, Zengli [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Wang, Jianfeng; Ren, Guoqiang; Xu, Ke, E-mail: kxu2006@sinano.ac.cn [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Suzhou Nanowin Science and Technology Co., Ltd., Suzhou 215123 (China)

2014-05-26T23:59:59.000Z

332

Efficiency enhancement of InGaN/GaN solar cells with nanostructures  

SciTech Connect (OSTI)

We demonstrate InGaN/GaN multi-quantum-well solar cells with nanostructures operating at a wavelength of 520?nm. Nanostructures with a periodic nanorod or nanohole array are fabricated by means of modified nanosphere lithography. Under 1 sun air-mass 1.5 global spectrum illumination, a fill factor of 50 and an open circuit voltage of 1.9?V are achieved in spite of very high indium content in InGaN alloys usually causing degradation of crystal quality. Both the nanorod array and the nanohole array significantly improve the performance of solar cells, while a larger enhancement is observed for the nanohole array, where the conversion efficiency is enhanced by 51%.

Bai, J.; Yang, C. C.; Athanasiou, M.; Wang, T. [Department of Electronics and Electrical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

2014-02-03T23:59:59.000Z

333

Optoelectrical characteristics of green light-emitting diodes containing thick InGaN wells with digitally grown InN/GaN  

Science Journals Connector (OSTI)

Compared with conventionally grown thin InGaN wells, thick InGaN wells with digitally grown InN/GaN exhibit superior optical properties. The activation energy (48 meV) of thick InGaN...

Yu, Chun-Ta; Lai, Wei-Chih; Yen, Cheng-Hsiung; Hsu, Hsu-Cheng; Chang, Shoou-Jinn

2014-01-01T23:59:59.000Z

334

THE HUBBLE SPACE TELESCOPE CLUSTER SUPERNOVA SURVEY. III. CORRELATED PROPERTIES OF TYPE Ia SUPERNOVAE AND THEIR HOSTS AT 0.9 < z < 1.46  

SciTech Connect (OSTI)

Using the sample of Type Ia supernovae (SNe Ia) discovered by the Hubble Space Telescope (HST) Cluster Supernova Survey and augmented with HST-observed SNe Ia in the Great Observatories Origins Deep Survey (GOODS) fields, we search for correlations between the properties of SNe and their host galaxies at high redshift. We use galaxy color and quantitative morphology to determine the red sequence in 25 clusters and develop a model to distinguish passively evolving early-type galaxies from star-forming galaxies in both clusters and the field. With this approach, we identify 6 SN Ia hosts that are early-type cluster members and 11 SN Ia hosts that are early-type field galaxies. We confirm for the first time at z > 0.9 that SNe Ia hosted by early-type galaxies brighten and fade more quickly than SNe Ia hosted by late-type galaxies. We also show that the two samples of hosts produce SNe Ia with similar color distributions. The relatively simple spectral energy distributions expected for passive galaxies enable us to measure stellar masses of early-type SN hosts. In combination with stellar mass estimates of late-type GOODS SN hosts from Thomson and Chary, we investigate the correlation of host mass with Hubble residual observed at lower redshifts. Although the sample is small and the uncertainties are large, a hint of this relation is found at z > 0.9. By simultaneously fitting the average cluster galaxy formation history and dust content to the red-sequence scatters, we show that the reddening of early-type cluster SN hosts is likely E(B - V) {approx}< 0.06. The similarity of the field and cluster early-type host samples suggests that field early-type galaxies that lie on the red sequence may also be minimally affected by dust. Hence, the early-type-hosted SNe Ia studied here occupy a more favorable environment to use as well-characterized high-redshift standard candles than other SNe Ia.

Meyers, J.; Barbary, K.; Fakhouri, H. K.; Goldhaber, G. [Department of Physics, University of California Berkeley, Berkeley, CA 94720 (United States); Aldering, G.; Faccioli, L.; Hsiao, E. [E.O. Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, CA 94720 (United States); Barrientos, L. F. [Departmento de Astronomia, Pontificia Universidad Catolica de Chile, Santiago (Chile); Brodwin, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dawson, K. S. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Deustua, S.; Fruchter, A. S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Doi, M.; Ihara, Y. [Institute of Astronomy, Graduate School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Eisenhardt, P. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Gilbank, D. G. [Department of Physics and Astronomy, University Of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Gladders, M. D. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Gonzalez, A. H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Hattori, T. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North Aohaku Place, Hilo, HI 96720 (United States); Kashikawa, N., E-mail: jmeyers314@berkeley.edu [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Collaboration: Supernova Cosmology Project; and others

2012-05-01T23:59:59.000Z

335

PULSATING REVERSE DETONATION MODELS OF TYPE Ia SUPERNOVAE. I. DETONATION IGNITION  

SciTech Connect (OSTI)

Observational evidences point to a common explosion mechanism of Type Ia supernovae based on a delayed detonation of a white dwarf (WD). Although several scenarios have been proposed and explored by means of one, two, and three-dimensional simulations, the key point still is the understanding of the conditions under which a stable detonation can form in a destabilized WD. One of the possibilities that have been invoked is that an inefficient deflagration leads to the pulsation of a Chandrasekhar-mass WD, followed by formation of an accretion shock around a carbon-oxygen rich core. The accretion shock confines the core and transforms kinetic energy from the collapsing halo into thermal energy of the core, until an inward moving detonation is formed. This chain of events has been termed Pulsating Reverse Detonation (PRD). In this work we explore the robustness of the detonation ignition for different PRD models characterized by the amount of mass burned during the deflagration phase, M {sub defl}. The evolution of the WD up to the formation of the accretion shock has been followed with a three-dimensional hydrodynamical code with nuclear reactions turned off. We found that detonation conditions are achieved for a wide range of M {sub defl}. However, if the nuclear energy released during the deflagration phase is close to the WD binding energy ({approx}0.46 x 10{sup 51} erg {yields} M {sub defl} {approx} 0.30 M {sub sun}) the accretion shock cannot heat and confine the core efficiently and detonation conditions are not robustly achieved.

Bravo, Eduardo; GarcIa-Senz, Domingo [Department de FIsica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain)], E-mail: eduardo.bravo@upc.edu, E-mail: domingo.garcia@upc.edu

2009-04-20T23:59:59.000Z

336

The effect of turbulent intermittency on the deflagration to detonation transition in SN Ia explosions  

E-Print Network [OSTI]

We examine the effects of turbulent intermittency on the deflagration to detonation transition (DDT) in Type Ia supernovae. The Zel'dovich mechanism for DDT requires the formation of a nearly isothermal region of mixed ash and fuel that is larger than a critical size. We primarily consider the hypothesis by Khokhlov et al. and Niemeyer and Woosley that the nearly isothermal, mixed region is produced when the flame makes the transition to the distributed regime. We use two models for the distribution of the turbulent velocity fluctuations to estimate the probability as a function of the density in the exploding white dwarf that a given region of critical size is in the distributed regime due to strong local turbulent stretching of the flame structure. We also estimate lower limits on the number of such regions as a function of density. We find that the distributed regime, and hence perhaps DDT, occurs in a local region of critical size at a density at least a factor of 2-3 larger than predicted for mean conditions that neglect intermittency. This factor brings the transition density to be much larger than the empirical value from observations in most situations. We also consider the intermittency effect on the more stringent conditions for DDT by Lisewski et al. and Woosley. We find that a turbulent velocity of $10^8$ cm/s in a region of size $10^6$ cm, required by Lisewski et al., is rare. We expect that intermittency gives a weaker effect on the Woosley model with stronger criterion. The predicted transition density from this criterion remains below $10^7$ g/cm$^3$ after accounting for intermittency using our intermittency models.

Liubin Pan; J. Craig Wheeler; John Scalo

2008-03-12T23:59:59.000Z

337

THE DETONATION MECHANISM OF THE PULSATIONALLY ASSISTED GRAVITATIONALLY CONFINED DETONATION MODEL OF Type Ia SUPERNOVAE  

SciTech Connect (OSTI)

We describe the detonation mechanism composing the 'pulsationally assisted' gravitationally confined detonation (GCD) model of Type Ia supernovae. This model is analogous to the previous GCD model reported in Jordan et al.; however, the chosen initial conditions produce a substantively different detonation mechanism, resulting from a larger energy release during the deflagration phase. The resulting final kinetic energy and {sup 56}Ni yields conform better to observational values than is the case for the 'classical' GCD models. In the present class of models, the ignition of a deflagration phase leads to a rising, burning plume of ash. The ash breaks out of the surface of the white dwarf, flows laterally around the star, and converges on the collision region at the antipodal point from where it broke out. The amount of energy released during the deflagration phase is enough to cause the star to rapidly expand, so that when the ash reaches the antipodal point, the surface density is too low to initiate a detonation. Instead, as the ash flows into the collision region (while mixing with surface fuel), the star reaches its maximally expanded state and then contracts. The stellar contraction acts to increase the density of the star, including the density in the collision region. This both raises the temperature and density of the fuel-ash mixture in the collision region and ultimately leads to thermodynamic conditions that are necessary for the Zel'dovich gradient mechanism to produce a detonation. We demonstrate feasibility of this scenario with three three-dimensional (3D), full star simulations of this model using the FLASH code. We characterized the simulations by the energy released during the deflagration phase, which ranged from 38% to 78% of the white dwarf's binding energy. We show that the necessary conditions for detonation are achieved in all three of the models.

Jordan, G. C. IV; Graziani, C.; Weide, K.; Norris, J.; Hudson, R.; Lamb, D. Q. [Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States); Fisher, R. T. [Department of Physics, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Townsley, D. M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Meakin, C. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Reid, L. B. [NTEC Environmental Technology, Subiaco WA 6008 (Australia)

2012-11-01T23:59:59.000Z

338

Off-center ignition in type Ia supernova: I. Initial evolution and implications for delayed detonation  

E-Print Network [OSTI]

The explosion of a carbon-oxygen white dwarf as a Type Ia supernova is known to be sensitive to the manner in which the burning is ignited. Studies of the pre-supernova evolution suggest asymmetric, off-center ignition, and here we explore its consequences in two- and three-dimensional simulations. Compared with centrally ignited models, one-sided ignitions initially burn less and release less energy. For the distributions of ignition points studied, ignition within two hemispheres typically leads to the unbinding of the white dwarf, while ignition within a small fraction of one hemisphere does not. We also examine the spreading of the blast over the surface of the white dwarf that occurs as the first plumes of burning erupt from the star. In particular, our studies test whether the collision of strong compressional waves can trigger a detonation on the far side of the star as has been suggested by Plewa et al. (2004). The maximum temperature reached in these collisions is sensitive to how much burning and expansion has already gone on, and to the dimensionality of the calculation. Though detonations are sometimes observed in 2D models, none ever happens in the corresponding 3D calculations. Collisions between the expansion fronts of multiple bubbles also seem, in the usual case, unable to ignite a detonation. "Gravitationally confined detonation" is therefore not a robust mechanism for the explosion. Detonation may still be possible in these models however, either following a pulsation or by spontaneous detonation if the turbulent energy is high enough.

F. K. Roepke; S. E. Woosley; W. Hillebrandt

2006-09-04T23:59:59.000Z

339

A Three-Dimensional Picture of the Delayed-Detonation Model of Type Ia Supernovae  

E-Print Network [OSTI]

Deflagration models poorly explain the observed diversity of SNIa. Current multidimensional simulations of SNIa predict a significant amount of, so far unobserved, carbon and oxygen moving at low velocities. It has been proposed that these drawbacks can be resolved if there is a sudden jump to a detonation (delayed detonation), but this kind of models has been explored mainly in one dimension. Here we present new three-dimensional delayed detonation models in which the deflagraton-to-detonation transition (DDT) takes place in conditions like those favored by one-dimensional models. We have used a SPH code adapted to SNIa with algorithms devised to handle subsonic as well as supersonic combustion fronts. The starting point was a C-O white dwarf of 1.38 solar masses. When the average density on the flame surface reached 2-3x10^7 g/cm^3 a detonation was launched. The detonation wave processed more than 0.3 solar masses of carbon and oxygen, emptying the central regions of the ejecta of unburned fuel and raising its kinetic energy close to the fiducial 10^51 ergs expected from a healthy Type Ia supernova. The final amount of 56Ni synthesized also was in the correct range. However, the mass of carbon and oxygen ejected is still too high. The three-dimensional delayed detonation models explored here show an improvement over pure deflagration models, but they still fail to coincide with basic observational constraints. However, there are many aspects of the model that are still poorly known (geometry of flame ignition, mechanism of DDT, properties of detonation waves traversing a mixture of fuel and ashes). Therefore, it will be worth pursuing its exploration to see if a good SNIa model based on the three-dimensional delayed detonation scenario can be obtained.

Eduardo Bravo; Domingo Garcia-Senz

2007-12-04T23:59:59.000Z

340

Timescale stretch parameterization of Type Ia supernova B-band light curves  

SciTech Connect (OSTI)

R-band intensity measurements along the light curve of Type Ia supernovae discovered by the Cosmology Project (SCP) are fitted in brightness to templates allowing a free parameter the time-axis width factor w identically equal to s times (1+z). The data points are then individually aligned in the time-axis, normalized and K-corrected back to the rest frame, after which the nearly 1300 normalized intensity measurements are found to lie on a well-determined common rest-frame B-band curve which we call the ''composite curve.'' The same procedure is applied to 18 low-redshift Calan/Tololo SNe with Z < 0.11; these nearly 300 B-band photometry points are found to lie on the composite curve equally well. The SCP search technique produces several measurements before maximum light for each supernova. We demonstrate that the linear stretch factor, s, which parameterizes the light-curve timescale appears independent of z, and applies equally well to the declining and rising parts of the light curve. In fact, the B band template that best fits this composite curve fits the individual supernova photometry data when stretched by a factor s with chi 2/DoF {approx} 1, thus as well as any parameterization can, given the current data sets. The measurement of the data of explosion, however, is model dependent and not tightly constrained by the current data. We also demonstrate the 1 + z light-cure time-axis broadening expected from cosmological expansion. This argues strongly against alternative explanations, such as tired light, for the redshift of distant objects.

Goldhaber, G.; Groom, D.E.; Kim, A.; Aldering, G.; Astier, P.; Conley, A.; Deustua, S.E.; Ellis, R.; Fabbro, S.; Fruchter, A.S.; Goobar, A.; Hook, I.; Irwin, M.; Kim, M.; Knop, R.A.; Lidman, C.; McMahon, R.; Nugent, P.E.; Pain, R.; Panagia, N.; Pennypacker, C.R.; Perlmutter, S.; Ruiz-Lapuente, P.; Schaefer, B.; Walton, N.A.; York, T.

2001-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Exploring Cosmological Expansion Parametrizations with the Gold SnIa Dataset  

E-Print Network [OSTI]

We use the SnIa Gold dataset to compare LCDM with 10 representative parametrizations of the recent Hubble expansion history $H(z)$. For the comparison we use two statistical tests; the usual $\\chi_{min}^2$ which is insensitive to the parametrization number of parameters, and a statistic we call the p-test which depends on both the value of $\\chi_{min}^2$ and the number $n$ of the parametrization parameters. The p-test measures the confidence level to which the parameter values corresponding to LCDM are excluded from the viewpoint of the parametrization tested. For example, for a linear equation of state parametrization $w(z)=w_0 + w_1 z$ the LCDM parameter values ($w_0=-1$, $w_1=0$) are excluded at 75% confidence level. We use a flat prior and $\\Omega_{0m}=0.3$. All parametrizations tested are consistent with the Gold dataset at their best fit. According to both statistical tests, the worst fits among the 10 parametrizations, correspond to the Chaplygin gas, the brane world and the Cardassian parametrizations. The best fit is achieved by oscillating parametrizations which can exclude the parameter values corresponding to LCDM at 85% confidence level. Even though this level of significance does not provide a statistically significant exclusion of LCDM (it is less than $2\\sigma$) and does not by itself constitute conclusive evidence for oscillations in the cosmological expansion, when combined with similar independent recent evidence for oscillations coming from the CMB and matter power spectra it becomes an issue worth of further investigation.

R. Lazkoz; S. Nesseris; L. Perivolaropoulos

2005-11-10T23:59:59.000Z

342

Surface Science Analysis of GaAs Photocathodes Following Sustained...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Spectrometry (RBS), Atomic Force Microscopy (AFM) and Secondary Ion Mass Spectrometry (SIMS). In addition, strained super-lattice GaAs photocathode samples, removed from the CEBAF...

343

P-type doping of GaN  

SciTech Connect (OSTI)

After implantation of As, As + Be, and As + Ga into GaN and annealing for short durations at temperatures as high as 1500 C, the GaN films remained highly resistive. It was apparent from c-RBS studies that although implantation damage did not create an amorphous layer in the GaN film, annealing at 1500 C did not provide enough energy to completely recover the radiation damage. Disorder recovered significantly after annealing at temperatures up to 1500 C, but not completely. From SIMS analysis, oxygen contamination in the AIN capping layer causes oxygen diffusion into the GaN film above 1400 C. The sapphire substrate (A1203) also decomposed and oxygen penetrated into the backside of the GaN layer above 1400 C. To prevent donor-like oxygen impurities from the capping layer and the substrate from contaminating the GaN film and compensating acceptors, post-implantation annealing should be done at temperatures below 1500 C. Oxygen in the cap could be reduced by growing the AIN cap on the GaN layer after the GaN growth run or by depositing the AIN layer in a ultra high vacuum (UHV) system post-growth to minimize residual oxygen and water contamination. With longer annealing times at 1400 C or at higher temperatures with a higher quality AIN, the implantation drainage may fully recover.

Wong, R.K.

2000-04-10T23:59:59.000Z

344

Electronic properties of the AlGaN/GaN heterostructure and two-dimensional electron gas observed by electroreflectance  

Science Journals Connector (OSTI)

A contacted electroreflectance technique was used to investigate AlGaN/GaN heterostructures and their intrinsic electric field-induced properties. By studying variations in the electroreflectance with applied field spectral features associated with the AlGaN barrier the two-dimensional electron gas at the interface and bulk GaN were identified. Barrier-layer composition and electric field were determined from the AlGaN FranzKeldysh oscillations. For a high mobilityheterostructure grown on SiC measured AlGaN polarizationelectric field and two-dimensional electron gas density approached values predicted by a standard bandstructure model. The two-dimensional electron gas produced a broad field-tunable first derivative electroreflectance feature. With a dielectric function calculation we describe the line shape and relative amplitude of the two-dimensional electron gas electroreflectance feature for a wide range of electron density and applied field values.

S. R. Kurtz; A. A. Allerman; D. D. Koleske; A. G. Baca; R. D. Briggs

2004-01-01T23:59:59.000Z

345

Spectral-kinetic properties of heterostructures with GaAsSb/InGaAs/GaAs-based quantum wells emitting in the range of 1.0-1.2 {mu}m  

SciTech Connect (OSTI)

The spectral-kinetic properties of heterostructures with GaAs/GaAsSb-based and GaAsSb/InGaAs/GaAs-based quantum wells, emitting in the range of 1.0-1.2 {mu}m are studied with picosecond and nanosecond temporal resolution. Intense photoluminescence in the GaAsSb/InGaAs/GaAs structure, as well as an increase in the photoluminescence wavelength by a factor of 2.5 and a shift of the location of the maximum of the peak ({approx}100 meV) to the longer-wavelength region were observed up to room temperature. It is established that as the molar fraction of Sb and the thickness of the InGaAs layer increase, the energy of the fundamental transition decreases by a factor of 140 meV compared with the GaAsSb/InGaAs/GaAs structure with a lower Sb content and a smaller thickness of the InGaAs layer. At 300 K, the emission wavelength of such a structure was 1.18 {mu}m. In addition, an increase in the thickness of the InGaAs layer led to an increase in the room-temperature photoluminescence intensity by a factor of 60, which is associated with a decrease in the energy of the fundamental state for electrons in the InGaAs layer and, consequently, to larger electron localization and smaller temperature quenching of photoluminescence.

Morozov, S. V., E-mail: more@ipm.sci.-nnov.ru; Kryzhkov, D. I.; Aleshkin, V. Ya. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N.; Vikhrova, O. I. [Nizhni Novgorod State University, Physical-Technical Research Institute (Russian Federation)] [Nizhni Novgorod State University, Physical-Technical Research Institute (Russian Federation)

2013-11-15T23:59:59.000Z

346

Vacancy-Induced 22 Reconstruction of the Ga(111) Surface of GaAs  

Science Journals Connector (OSTI)

Vacancy formation on the GaAs(111) surface is calculated to be strongly exothermic in character. The creation of one vacancy in each 22 cell allows the remaining Ga surface atoms to have a large inward relaxation, resulting in a 2.3-eV reduction in energy. It also transforms the polar (111) surface into a nonpolar (110)-like surface. The calculations provide strong support for the vacancy model of Tong et al., which is determined from analysis of low-energy-electron-diffraction data.

D. J. Chadi

1984-05-21T23:59:59.000Z

347

GaAs single quantum dot embedded into AlGaAs nanowire  

SciTech Connect (OSTI)

We report on a study of the photoluminescence spectra taken from quasi one-dimensional and quasi zero-dimensional semiconductor heterostructures. The structures were grown by molecular-beam epitaxy in (111) direction and were cylindrical nanowires based on AlGaAs, of 20 - 50 nm in diameter and 0.5 - 1 ?m in length. Inside the nanowires contain one or two GaAs quantum dots, of 2 nm thick and 15 - 45 nm in diameter. We studied a single nanowire. The photoluminescence and photoluminescence excitation spectra were registered as a function of the intensity of optical excitation.

Kochereshko, V. P.; Kats, V. N. [A.F.Ioffe Physical-Technical Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russia and Spin Optics Laboratory, Saint Petersburg State University, Ul'yanovskaya 1, Petrodvorets, St. Petersburg, 198904 (Russian Federation); Platonov, A. V. [A.F.Ioffe Physical-Technical Institute, Politekhnicheskaya 26, 194021, St. Petersburg (Russian Federation); Cirlin, G. E.; Bouravleuv, A. D.; Samsonenko, Yu. B. [A.F.Ioffe Physical-Technical Institute, Politekhnicheskaya 26, 194021, St. Petersburg, Russia and St. Petersburg Academic University of the RAS Khlopina 8/3, 195220, St. Petersburg (Russian Federation); Besombes, L.; Mariette, H. [CEA-CNRS group Nanophysique et Semiconducteurs, CEA, INAC, SP2M, and Institut Nel, 17 rue des Martyrs, F-38054 Grenoble (France)

2013-12-04T23:59:59.000Z

348

Observation of photo darkening in self assembled InGaAs/GaAs quantum dots  

SciTech Connect (OSTI)

Photo darkening was observed in epitaxial InGaAs/GaAs quantum dots (QDs). The photoluminescence (PL) intensity of the QDs showed a non-reversible decrease under continuous laser irradiation. The time constants varied from tens of minutes to several hours, depending on the applied laser power. Based on the spectral evolution, it was concluded that the observed phenomenon should originate from laser induced structural damage and a sustained increase of non-radiative recombination rate in the wetting layer. Additionally, according to the PL decay dynamics at different laser powers, it is argued that there should exist other processes that hinder PL degradation at a high laser power.

Zhang Hongyi; Chen Yonghai; Zhou Xiaolong; Jia Yanan; Ye Xiaoling; Xu Bo; Wang Zhanguo [Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

2013-05-07T23:59:59.000Z

349

Nitrogen-concentration control in GaNAs/AlGaAs quantum wells using nitrogen ?-doping technique  

SciTech Connect (OSTI)

GaNAs/Al{sub 0.35}Ga{sub 0.65}As multiple quantum wells (MQWs) with nitrogen ?-doping were fabricated on GaAs (100) substrates by plasma-assisted molecular beam epitaxy. High controllability of nitrogen-concentrations in the MQWs was achieved by tuning nitrogen ?-doping time. The maximum nitrogen concentration in the MQWs was 2.8%. The MQWs exhibit intense, narrow photoluminescence emission.

Mano, Takaaki; Jo, Masafumi; Kuroda, Takashi; Noda, Takeshi; Sugimoto, Yoshimasa; Sakuma, Yoshiki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Elborg, Martin; Sakoda, Kazuaki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan and Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)

2014-05-15T23:59:59.000Z

350

Theoretical studies of optical gain tuning by hydrostatic pressure in GaInNAs/GaAs quantum wells  

SciTech Connect (OSTI)

In order to describe theoretically the tuning of the optical gain by hydrostatic pressure in GaInNAs/GaAs quantum wells (QWs), the optical gain calculations within kp approach were developed and applied for N-containing and N-free QWs. The electronic band structure and the optical gain for GaInNAs/GaAs QW were calculated within the 10-band kp model which takes into account the interaction of electron levels in the QW with the nitrogen resonant level in GaInNAs. It has been shown that this interaction increases with the hydrostatic pressure and as a result the optical gain for GaInNAs/GaAs QW decreases by about 40% and 80% for transverse electric and transverse magnetic modes, respectively, for the hydrostatic pressure change from 0 to 40 kilobars. Such an effect is not observed for N-free QWs where the dispersion of electron and hole energies remains unchanged with the hydrostatic pressure. This is due to the fact that the conduction and valence band potentials in GaInAs/GaAs QW scale linearly with the hydrostatic pressure.

Gladysiewicz, M.; Wartak, M. S. [Institute of Physics, Wroclaw University of Technology, 50-370 Wroclaw, Wybrzeze Wyspianskiego 27 (Poland); Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Kudrawiec, R. [Institute of Physics, Wroclaw University of Technology, 50-370 Wroclaw, Wybrzeze Wyspianskiego 27 (Poland)

2014-01-21T23:59:59.000Z

351

Partially filled intermediate band of Cr-doped GaN films  

SciTech Connect (OSTI)

We investigated the band structure of sputtered Cr-doped GaN (GaCrN) films using optical absorption, photoelectron yield spectroscopy, and charge transport measurements. It was found that an additional energy band is formed in the intrinsic band gap of GaN upon Cr doping, and that charge carriers in the material move in the inserted band. Prototype solar cells showed enhanced short circuit current and open circuit voltage in the n-GaN/GaCrN/p-GaN structure compared to the GaCrN/p-GaN structure, which validates the proposed concept of an intermediate-band solar cell.

Sonoda, S. [Department of Electronics, Kyoto Institute of Technology, Kyoto 606-8585 (Japan)

2012-05-14T23:59:59.000Z

352

Localized corrosion of GaAs surfaces and formation of porous GaAs  

SciTech Connect (OSTI)

The present work deals with pitting corrosion of p- and n-type GaAs (100). Pit growth can be electrochemically initiated on both conduction types in chloride-containing solutions and leads after extended periods of time to the formation of a porous GaAs structure. In the case of p-type material, localized corrosion is only observed if a passivating film is present on the surface, otherwise -- e.g. in acidic solutions -- the material suffers from a uniform attack (electropolishing) which is independent of the anion present. In contrast, pitting corrosion of n-type material can be triggered independent of the presence of an oxide film. This is explained in terms of the different current limiting factor for the differently doped materials (oxide film in the case of the p- and a space charge layer in the case of the n-GaAs). The porous structure was characterized by SEM, EDX and AES, and consists mainly of GaAs. From scratch experiments it is clear that the pit initiation process is strongly influenced by surface defects. For n-type material, AFM investigations show that light induced roughening of the order of several hundred nm occurs under non-passivating conditions. This nm- scale roughening however does not affect the pitting process.

Schmuki, P.; Vitus, C.M.; Isaacs, H.S. [Brookhaven National Lab., Upton, NY (United States); Fraser, J.; Graham, M.J. [National Research Council of Canada, Ottawa, ON (Canada). Inst. for Microstructural Sciences

1995-12-01T23:59:59.000Z

353

GaAs/AlGaAs nanostructured composites for free-space and integrated optical devices  

E-Print Network [OSTI]

after development with MIBK:IPA=1:2 for 2min. Different fillon GaAs developed with MIBK:IPA=1:2 for (a) 1 min; (b) 2d) shows a nonoptimized developer, MIBK:IPA=2:1, used for 3

Tsai, Chia-Ho

2006-01-01T23:59:59.000Z

354

Reliability of AlGaN/GaN high electron mobility transistors on low dislocation density bulk GaN substrate: Implications of surface step edges  

SciTech Connect (OSTI)

To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gate leakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths. Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges of surface steps.

Killat, N., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk; Montes Bajo, M.; Kuball, M., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk [Center for Device Thermography and Reliability (CDTR), H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Paskova, T. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States) [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Materials Science and Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 (United States); Evans, K. R. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States)] [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Leach, J. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States) [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Li, X.; zgr, .; Morko, H. [Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States)] [Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Chabak, K. D.; Crespo, A.; Gillespie, J. K.; Fitch, R.; Kossler, M.; Walker, D. E.; Trejo, M.; Via, G. D.; Blevins, J. D. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)] [Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

2013-11-04T23:59:59.000Z

355

Categorical Exclusion Determination Form Proposed Action Title...  

Broader source: Energy.gov (indexed) [DOE]

will take place at Varentec Inc. (San Jose, CA), Georgia Tech University (Atlanta, GA), Electric Power Research Institute (Knoxville, TN), and Waukesha Electric Systems Inc....

356

Review of Strategies and Technologies for Demand-Side Management on Isolated Mini-Grids  

E-Print Network [OSTI]

Center for Appropriate Technology. Alice Springs, Australia.Report of Intermediate Technology Consultants to Overseasand Communication Technologies and Development. Atlanta, GA.

Harper, Meg

2014-01-01T23:59:59.000Z

357

About the Data in Buildings Performance Database | Department...  

Broader source: Energy.gov (indexed) [DOE]

College* Arlington County, VA* Arvada, CO* Atlanta, GA* Beaverton, OR* Boston, MA* Camas School District, WA* Chicago, IL* Clark County, NV* Cleveland, OH* Columbia, MO*...

358

Home Depot Foundation | Open Energy Information  

Open Energy Info (EERE)

Name: Home Depot Foundation Place: Atlanta, GA Website: http:www.homedepotfoundation References: Home Depot Foundation1 Information About Partnership with NREL Partnership...

359

Standard Method of Test for Integrated Heat Pumps  

Broader source: Energy.gov [DOE]

Lead Performer: Oak Ridge National Laboratory - Oak Ridge, TN Partners: -- ASHRAE - Atlanta, GA -- Air Conditioning, Heating, and Refrigeration Institute (AHRI) - Arlington, VA

360

SR0006  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and technology are on display at the Department of Energy Environmental Management Science Program (EMSP) National Workshop in Atlanta, GA on April 25-27 at the Westin...

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Early Lessons Learned  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Lessons Learned Deploying a 100Gbps Network Steve Cotter Dept Head, Energy Sciences Network May 4, 2011 Enterprise Innovation Symposium Atlanta, GA Lawrence Berkeley National...

362

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

Plants Division FY 2013 1012012 - 09302013 Isaac "Andy" Aurelio Atlanta, GA Optimization of Pressurized Oxy-Combustion with Flameless Reactor - Phase I Georgia Tech will...

363

A Survey and Critical Review of the Literature on Indoor Air Quality, Ventilation and Health Symptoms in Schools  

E-Print Network [OSTI]

from the California Healthy Building Study, Phase 1.ASHRAE IAQ 91 Healthy Buildings, Atlanta, GA, ASHRAE, 228-1 of the California Healthy Building Study. Indoor Air, 3:

Daisey, Joan M.

2010-01-01T23:59:59.000Z

364

E-Print Network 3.0 - african-american women participating Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Atlanta, GA African Americans in low-income, urban communities are at high... that low income African Americans living ... Source: Duong, Timothy Q. - Yerkes National Primate...

365

E-Print Network 3.0 - aerosol monitoring Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dodd Way, Atlanta, GA, 30332, U.S.A. Abstract. Atmospheric aerosols scatter and absorb solar Source: Bergin, Mike - Schools of Civil and Environmental Engineering & Earth and...

366

FY 2014 VEHICLES INCUBATOR DE-FOA-0000988 SELECTION TABLE  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

shell non- intercalation cathodes and anodes Atlanta, GA This project will develop a nano- stuctured core to limit particle volume changes and protect the active material from...

367

E-Print Network 3.0 - animal structures Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1 Evaluating Animations as Student Aids in Learning Computer Algorithms Michael D. Byrne Psychology... Atlanta, GA 30332-0280 Abstract We conducted two experiments designed to...

368

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

Alternative Fuel and Advanced Technology Vehicle Project Install compressed natural gas fueling station at 4420 Buford Hwy. Atlanta, GA. Steven Richardson Digitally signed by...

369

Fisica Geral IA (2010/1) Nome 1 2 3 R1 R2 R3 Media Conc  

E-Print Network [OSTI]

Fisica Geral IA (2010/1) Nome 1 2 3 R1 R2 R3 M´edia Conc 1 ANDERSON SILVEIRA SALDANHA 0.5 5.2 4.7 0.7 3.5 4.5 1.5 - - 3.57 D M´edia 2.60 4.64 5.93 5.54 6.08 8.37 4.60 #12;20 40 60 80 100 A B C D FF 23

Stariolo, Daniel Adrián

370

The development of integrated chemical microsensors in GaAs  

SciTech Connect (OSTI)

Monolithic, integrated acoustic wave chemical microsensors are being developed on gallium arsenide (GaAs) substrates. With this approach, arrays of microsensors and the high frequency electronic components needed to operate them reside on a single substrate, increasing the range of detectable analytes, reducing overall system size, minimizing systematic errors, and simplifying assembly and packaging. GaAs is employed because it is both piezoelectric, a property required to produce the acoustic wave devices, and a semiconductor with a mature microelectronics fabrication technology. Many aspects of integrated GaAs chemical sensors have been investigated, including: surface acoustic wave (SAW) sensors; monolithic SAW delay line oscillators; GaAs application specific integrated circuits (ASIC) for sensor operation; a hybrid sensor array utilizing these ASICS; and the fully monolithic, integrated SAW array. Details of the design, fabrication, and performance of these devices are discussed. In addition, the ability to produce heteroepitaxial layers of GaAs and aluminum gallium arsenide (AlGaAs) makes possible micromachined membrane sensors with improved sensitivity compared to conventional SAW sensors. Micromachining techniques for fabricating flexural plate wave (FPW) and thickness shear mode (TSM) microsensors on thin GaAs membranes are presented and GaAs FPW delay line and TSM resonator performance is described.

CASALNUOVO,STEPHEN A.; ASON,GREGORY CHARLES; HELLER,EDWIN J.; HIETALA,VINCENT M.; BACA,ALBERT G.; HIETALA,S.L.

1999-11-01T23:59:59.000Z

371

CoNiGa High Temperature Shape Memory Alloys  

E-Print Network [OSTI]

commercially successful SMAs such as NiTi and Cu-based alloys. In recent years, the CoNiGa system has emerged as a new ferromagnetic shape memory alloy with some compositions exhibiting high martensitic transformation temperatures which makes CoNiGa a potential...

Dogan, Ebubekir

2011-10-21T23:59:59.000Z

372

The Essentials for GA Water Planning The Relationship  

E-Print Network [OSTI]

Water Plan and the Alabama-Florida-Georgia Water Sharing Dispute (The failure to agree on the two Management F. Conservation & Reuse a. Programs for Water Use Efficiency b. Consumptive Use & Return Flows GThe Essentials for GA Water Planning The Relationship Between the Proposed GA State Comprehensive

Rosemond, Amy Daum

373

Structure of a Si(100)22-Ga surface  

Science Journals Connector (OSTI)

The 22 structure formed on a Ga-adsorbed Si(100) surface is determined using tensor low-energy electron diffraction. I-V curves of the parallel dimer model are in excellent agreement with those of the experiment, indicating that the actual surface has parallel dimer structure. Specific displacements of the topmost two surface layers (the protrusion of the Ga dimer toward the vacuum, the increase of the bond length of the Ga dimer, the stretching of the Si dimer, and the movement of the Si dimer toward the Ga dimer) with the elongation of the Si dimer back bond are observed in the optimized geometry. The Ga-Si bond angle measured from the Si(100) surface plane is recovered with these displacements from that of the ideal geometry where each bond length is assumed to be the sum of Pauling covalent radii. Subsurface layers are also deformed to keep the bond lengths near their bulk values.

H. Sakama; K. Murakami; K. Nishikata; A. Kawazu

1994-11-15T23:59:59.000Z

374

Electronic structure of metallic antiperovskite compound GaCMn3  

Science Journals Connector (OSTI)

We have investigated the electronic structures of antiperovskite GaCMn3 and related Mn compounds SnCMn3, ZnCMn3, and ZnNMn3. In the paramagnetic state of GaCMn3, the Fermi surface nesting feature along the ?R direction is observed, which induces the antiferromagnetic (AFM) spin ordering with the nesting vector Q??R. Calculated susceptibilities confirm the nesting scenario for GaCMn3, and also explain various magnetic structures of other antiperovskite compounds. Through the band folding effect, the AFM phase of GaCMn3 is stabilized. Nearly equal densities of states at the Fermi level in the ferromagnetic and AFM phases of GaCMn3 indicate that two phases are competing in the ground state.

J. H. Shim; S. K. Kwon; B. I. Min

2002-07-10T23:59:59.000Z

375

Improved photovoltaic performance of InGaN/GaN solar cells with optimized transparent current spreading layers  

Science Journals Connector (OSTI)

In0.135Ga0.865N/GaN pin solar cells are fabricated and investigated with three types of transparent current spreading layers (TCSLs): Ni/Au layer type (Ni/Au-L), Ni/Au grid type (Ni/Au-G), and ITO layer type (I...

X. M. Cai; Y. Wang; Z. D. Li; X. Q. Lv; J. Y. Zhang; L. Y. Ying

2013-05-01T23:59:59.000Z

376

Analysis of the reduced thermal conductivity in InGaAs/GaAs quantum dot lasers from chirp characteristics  

E-Print Network [OSTI]

injection which we term "thermal impact" , the ther- mal conductivity of the active region is estimatedAnalysis of the reduced thermal conductivity in InGaAs/GaAs quantum dot lasers from chirp; published online 21 September 2006 The thermal conductivity of self-organized quantum dot QD active regions

Klotzkin, David

377

Surface roughening during depth profiling by Secondary Ion Mass Spectrometry (SIMS) in GaAlAs and GaAs  

Science Journals Connector (OSTI)

During bombardment of Ga1?xAlxAs and GaAs with oxygen we found an abrupt transition to higher sputter rates, change of the useful yield and significant increase of surface roughness at a well defined depth, which...

M. Gericke; T. Lill; M. Trapp; C. -E. Richter

378

GaN/ZnO and AlGaN/ZnO heterostructure LEDs: growth, fabrication, optical and electrical characterization  

E-Print Network [OSTI]

radiation hardness than Si, GaAs, CdS and GaN, therefore it should be suitable for space applications. Last novel optoelectronic devices circumventing the problem of p-type doping of ZnO. In such Al devices become reality: the problem of p-type doping of ZnO. So far, there is no way to reliably produce

Wetzel, Christian M.

379

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate  

E-Print Network [OSTI]

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium-effect transistors have been formed by incorporating barium strontium titanate (BST) deposited by rf magnetron in increased leakage. Due to its large dielectric constant, barium strontium ti- tanate [Ba1-xSrxTiO3, (BST

York, Robert A.

380

Si-CMOS-Like Integration of AlGaN/GaN Dielectric-Gated High-Electron-Mobility Transistors  

E-Print Network [OSTI]

the engineering of high mobility, high carrier density channels at III-Nitride heterointerfaces. In order to seize market share from silicon, the cost of manufacturing GaN-based devices must be further reduced. With the successful realization of 200mm GaN-on-Si...

Johnson, Derek Wade

2014-07-31T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

High-Performance Integrated Dual-Gate AlGaN/GaN Enhancement-Mode Transistor  

E-Print Network [OSTI]

In this letter, we present a new AlGaN/GaN enhancement-mode (E-mode) transistor based on a dual-gate structure. The dual gate allows the transistor to combine an E-mode behavior with low on-resistance and very high breakdown ...

Lu, Bin

382

High Breakdown ( > \\hbox {1500 V} ) AlGaN/GaN HEMTs by Substrate-Transfer Technology  

E-Print Network [OSTI]

In this letter, we present a new technology to increase the breakdown voltage of AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on Si substrates. This new technology is based on the removal of the original Si ...

Lu, Bin

383

Highly Ordered Ga Nanodroplets on a GaAs Surface Formed by a Focused Ion Beam Qiangmin Wei,1  

E-Print Network [OSTI]

Highly Ordered Ga Nanodroplets on a GaAs Surface Formed by a Focused Ion Beam Qiangmin Wei,1 Jie Lian,2,3 Wei Lu,4 and Lumin Wang1,5,* 1 Department of Materials Science and Engineering, University Arbor, Michigan 48109, USA 3 Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer

Lu, Wei

384

An AlGaAsGaAs quantum cascade laser operating with a thermoelectric cooler for spectroscopy of NH3  

E-Print Network [OSTI]

out using a compact thermo-electrically cooled laser package. The QCL described here is designedAn AlGaAs­GaAs quantum cascade laser operating with a thermoelectric cooler for spectroscopy of NH3. Langford b a Department of Electronics and Electrical Engineering, Rankine Building, University of Glasgow

385

Inductively Coupled Plasma Reactive Ion Etching of AlGaAsSb and InGaAsSb for Quaternary Antimonide MIM Thermophotovoltaics  

SciTech Connect (OSTI)

In this letter we report on the inductively coupled plasma reactive ion etching (ICP-RIE) of InGaAsSb and AlGaAsSb for the fabrication of quaternary monolithic interconnected module (MIM) thermophotovoltaic (TPV) devices. A rapid dry etch process is described that produces smooth surfaces using BCl[sub]3 for AlGaAsSb and InGaAsSb capped with GaSb. Uncapped InGaAsSb was etched by adding an H[sub]2 plasma preclean to reduce surface oxides. InGaAsSb etch rate was studied as a function of accelerating voltage, RF power, temperature and pressure. The etch conditions found for InGaAsSb were used for AlGaAsSb etching to determine the effectiveness for isolation of the MIM cells.

Palmisiano, M. N.; Peake, G. M.; Shul, R. J.; Ashby, C. I.; Cederberg, J. G.; Hafich, M. J.; Biefeld, R. M.

2002-10-01T23:59:59.000Z

386

GaAs/AlGaAs quantum wells with indirect-gap AlGaAs barriers for solar cell applications  

SciTech Connect (OSTI)

We have fabricated GaAs/AlGaAs quantum well (QW) solar cells in which 3?nm-thick QWs and indirect-gap Al{sub 0.78}Ga{sub 0.22}As barriers are embedded, and we studied extraction processes of photogenerated carriers in this QW system. The photocurrent under 700?nm light illumination at voltages close to the open-circuit voltage shows only a small reduction, indicating that the carrier recombination inside QWs is largely suppressed. We attribute this result to an efficient extraction of electrons from the QWs through the X-valley of AlGaAs. The insertion of QWs is shown to be effective in extending the absorption wavelengths and in enhancing the photocurrent. The use of indirect-gap materials as barriers is found to enhance carrier extraction processes, and result in an improved performance of QW solar cells.

Noda, T., E-mail: NODA.Takeshi@nims.go.jp; Otto, L. M.; Elborg, M.; Jo, M.; Mano, T.; Kawazu, T.; Han, L. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Sakaki, H. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Toyota Technological Institute, Nagoya 468-8511 (Japan)

2014-03-24T23:59:59.000Z

387

Magnetic-field effects on quasi-two-dimensional excitons in coupled GaAs?(Ga,Al)As quantum wells  

Science Journals Connector (OSTI)

We have used the variational procedure in the effective-mass and nondegenerate parabolic band approximations in order to investigate the effects of a magnetic field on the exciton effective mass and dispersion in semiconductor heterostructures. Calculations are performed for bulk GaAs, and two-dimensional and quasi-two-dimensional excitons in coupled GaAs?(Ga,Al)As quantum wells for applied magnetic fields perpendicular to the layers. A simple hydrogenlike envelope wave function provides the expected behavior for the exciton dispersion in a wide range of the center-of-mass momenta, and an analytical expression for the exciton effective mass is obtained. Present results lead to a magnetic-field dependent exciton effective mass and dispersion in quite good agreement with available experimental measurements in coupled GaAs?(Ga,Al)As quantum wells.

E. Reyes-Gmez, L. E. Oliveira, and M. de Dios-Leyva

2005-01-14T23:59:59.000Z

388

Atlanta, Georgia: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Jump to: navigation, search Jump to: navigation, search Equivalent URI DBpedia Coordinates 33.7489954°, -84.3879824° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.7489954,"lon":-84.3879824,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

389

First detection of $^{56}$Co gamma-ray lines from type Ia supernova (SN2014J) with INTEGRAL  

E-Print Network [OSTI]

We report the first ever detection of $^{56}$Co lines at 847 and 1237 keV and a continuum in the 200-400 keV band from the Type Ia supernova SN2014J in M82 with INTEGRAL observatory. The data were taken between 50th and 100th day since the SN2014J outburst. The line fluxes suggest that $0.62\\pm0.13~M\\odot$ of radioactive $^{56}$Ni were synthesized during the explosion. Line broadening gives a characteristic ejecta expansion velocity $V_e\\sim 2100\\pm 500~{\\rm km~s^{-1}}$. The flux at lower energies (200-400 keV) flux is consistent with the three-photon positronium annihilation, Compton downscattering and absorption in the $\\sim~1.4~M\\odot$ ejecta composed from equal fractions of iron-group and intermediate-mass elements and a kinetic energy $E_k\\sim 1.4~10^{51}~{\\rm erg}$. All these parameters are in broad agreement with a "canonical" model of an explosion of a Chandrasekhar-mass White Dwarf (WD), providing an unambiguous proof of the nature of Type Ia supernovae as a thermonuclear explosion of a solar mass co...

Churazov, E; Isern, J; Kndlseder, J; Jean, P; Lebrun, F; Chugai, N; Grebenev, S; Bravo, E; Sazonov, S; Renaud, M

2014-01-01T23:59:59.000Z

390

Chasing the phantom: A closer look at type Ia supernovae and the dark energy equation of state  

Science Journals Connector (OSTI)

Some recent observations provide >2? evidence for phantom dark energya value of the dark energy equation of state less than the cosmological-constant value of ?1. We focus on constraining the equation of state by combining current data from the most mature geometrical probes of dark energy: type Ia supernovae (SNe Ia) from the Supernova Legacy Survey (SNLS3), the Supernova Cosmology Project (Union2.1), and the Pan-STARRS1 survey (PS1); cosmic microwave background measurements from Planck and WMAP9; and a combination of measurements of baryon acoustic oscillations. The combined data are consistent with w=?1 for the Union2.1 sample, though they present moderate (?1.9?) evidence for a phantom value when either the SNLS3 or PS1 sample is used instead. We study the dependence of the constraints on the redshift, stretch, color, and host galaxy stellar mass of SNe, but we find no unusual trends. In contrast, the constraints strongly depend on any external H0 prior: a higher adopted value for the direct measurement of the Hubble constant (H0?71??km/s/Mpc) leads to ?2? evidence for phantom dark energy. Given Planck data, we can therefore make the following statement at 2? confidence: either the SNLS3 and PS1 data have systematics that remain unaccounted for or the Hubble constant is below 71??km/s/Mpc; else the dark energy equation of state is indeed phantom.

Daniel L. Shafer and Dragan Huterer

2014-03-06T23:59:59.000Z

391

Foreign Obligations Implementation Status Presentation  

National Nuclear Security Administration (NNSA)

January 13, 2004 Crowne Plaza Ravinia Atlanta, January 13, 2004 Crowne Plaza Ravinia Atlanta, January 13, 2004 Crowne Plaza Ravinia Atlanta, Georgia Georgia Obligations Accounting Implementation Workshop Obligations Accounting Implementation Workshop Foreign Obligations Implementation Status Brian G. Horn U.S. Nuclear Regulatory Commission January 13, 2004 Obligations Accounting Implementation Workshop January 13, 2 Obligations Accounting Implementation Workshop January 13, 2004 Crowne Plaza Ravinia Atlanta, GA 004 Crowne Plaza Ravinia Atlanta, GA Overview of Meeting Overview of Meeting * Review how the Obligation Tracking System is working * Presentations: - Review of Government notification procedures - Establishment of the beginning Obligation Balances for sites

392

Sputtering of Si, SiC, InAs, InP, Ge, GaAs, GaSb, and GaN by electrosprayed nanodroplets  

SciTech Connect (OSTI)

This article presents a characterization of the damage caused by energetic beams of electrosprayed nanodroplets striking the surfaces of single-crystal semiconductors including Si, SiC, InAs, InP, Ge, GaAs, GaSb, and GaN. The sputtering yield (number of atoms ejected per projectile's molecule), sputtering rate, and surface roughness are measured as functions of the beam acceleration potential. The maximum values of the sputtering yields range between 1.9 and 2.2 for the technological important but difficult to etch SiC and GaN respectively, and 4.5 for Ge. The maximum sputtering rates for the non-optimized beam flux conditions used in our experiments vary between 409?nm/min for SiC and 2381?nm/min for GaSb. The maximum sputtering rate for GaN is 630?nm/min. Surface roughness increases modestly with acceleration voltage, staying within 2?nm and 20?nm for all beamlet acceleration potentials and materials except Si. At intermediate acceleration potentials, the surface of Si is formed by craters orders of magnitude larger than the projectiles, yielding surface roughness in excess of 60?nm. The effect of projectile dose is studied in the case of Si. This parameter is correlated with the formation of the large craters typical of Si, which suggests that the accumulation of damage following consecutive impacts plays an important role in the interaction between beamlet and target.

Borrajo-Pelaez, Rafael; Grustan-Gutierrez, Enric; Gamero-Castao, Manuel, E-mail: mgameroc@uci.edu [Department of Mechanical and Aerospace Engineering, University of California, Irvine, California 92697 (United States)

2013-11-14T23:59:59.000Z

393

Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution  

E-Print Network [OSTI]

We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to provide the first conclusive evidence for cosmic deceleration that preceded the current epoch of cosmic acceleration. These objects, discovered during the course of the GOODS ACS Treasury program, include 6 of the 7 highest-redshift SNe Ia known, all at z>1.25, and populate the Hubble diagram in unexplored territory. The luminosity distances to these and 170 previous SNe Ia are provided. A purely kinematic interpretation of the SN Ia sample provides evidence at the > 99% confidence level for a transition from deceleration to acceleration or similarly, strong evidence for a cosmic jerk. Using a simple model of the expansion history, the transition between the two epochs is constrained to be at z=0.46 +/- 0.13. The data are consistent with the cosmic concordance model of Omega_M ~ 0.3, Omega_Lambda~0.7 (chi^2_dof=1.06), and are inconsistent with a simple model of evolution or dust as an alternative to dark energy. For a flat Universe with a cosmological constant. When combined with external flat-Universe constraints we find w=-1.02 + 0.13 - 0.19 (and $dark energy, P = w\\rho c^2. Joint constraints on both the recent equation of state of dark energy, $w_0$, and its time evolution, dw/dz, are a factor of ~8 more precise than its first estimate and twice as precise as those without the SNe Ia discovered with HST. Our constraints are consistent with the static nature of and value of w expected for a cosmological constant (i.e., w_0 = -1.0, dw/dz = 0), and are inconsistent with very rapid evolution of dark energy. We address consequences of evolving dark energy for the fate of the Universe.

Adam G. Riess; Louis-Gregory Strolger; John Tonry; Stefano Casertano; Henry C. Ferguson; Bahram Mobasher; Peter Challis; Alexei V. Filippenko; Saurabh Jha; Weidong Li; Ryan Chornock; Robert P. Kirshner; Bruno Leibundgut; Mark Dickinson; Mario Livio; Mauro Giavalisco; Charles C. Steidel; Narciso Benitez; Zlatan Tsvetanov

2004-02-23T23:59:59.000Z

394

Failed-detonation Supernovae: Subluminous Low-velocity Ia Supernovae and their Kicked Remnant White Dwarfs with Iron-rich Cores  

Science Journals Connector (OSTI)

Type Ia supernovae (SNe Ia) originate from the thermonuclear explosions of carbon-oxygen (C-O) white dwarfs (WDs). The single-degenerate scenario is a well-explored model of SNe Ia where unstable thermonuclear burning initiates in an accreting, Chandrasekhar-mass WD and forms an advancing flame. By several proposed physical processes, the rising, burning material triggers a detonation, which subsequently consumes and unbinds the WD. However, if a detonation is not triggered and the deflagration is too weak to unbind the star, a completely different scenario unfolds. We explore the failure of the gravitationally confined detonation mechanism of SNe Ia, and demonstrate through two-dimensional and three-dimensional simulations the properties of failed-detonation SNe. We show that failed-detonation SNe expel a few 0.1 M ? of burned and partially burned material and that a fraction of the material falls back onto the WD, polluting the remnant WD with intermediate-mass and iron-group elements that likely segregate to the core forming a WD whose core is iron rich. The remaining material is asymmetrically ejected at velocities comparable to the escape velocity from the WD, and in response, the WD is kicked to velocities of a few hundred km s1. These kicks may unbind the binary and eject a runaway/hypervelocity WD. Although the energy and ejected mass of the failed-detonation SN are a fraction of typical thermonuclear SNe, they are likely to appear as subluminous low-velocity SNe Ia. Such failed detonations might therefore explain or are related to the observed branch of peculiar SNe Ia, such as the family of low-velocity subluminous SNe (SN 2002cx/SN 2008ha-like SNe).

George C. Jordan, IV; Hagai B. Perets; Robert T. Fisher; Daniel R. van Rossum

2012-01-01T23:59:59.000Z

395

FAILED-DETONATION SUPERNOVAE: SUBLUMINOUS LOW-VELOCITY Ia SUPERNOVAE AND THEIR KICKED REMNANT WHITE DWARFS WITH IRON-RICH CORES  

SciTech Connect (OSTI)

Type Ia supernovae (SNe Ia) originate from the thermonuclear explosions of carbon-oxygen (C-O) white dwarfs (WDs). The single-degenerate scenario is a well-explored model of SNe Ia where unstable thermonuclear burning initiates in an accreting, Chandrasekhar-mass WD and forms an advancing flame. By several proposed physical processes, the rising, burning material triggers a detonation, which subsequently consumes and unbinds the WD. However, if a detonation is not triggered and the deflagration is too weak to unbind the star, a completely different scenario unfolds. We explore the failure of the gravitationally confined detonation mechanism of SNe Ia, and demonstrate through two-dimensional and three-dimensional simulations the properties of failed-detonation SNe. We show that failed-detonation SNe expel a few 0.1 M{sub Sun} of burned and partially burned material and that a fraction of the material falls back onto the WD, polluting the remnant WD with intermediate-mass and iron-group elements that likely segregate to the core forming a WD whose core is iron rich. The remaining material is asymmetrically ejected at velocities comparable to the escape velocity from the WD, and in response, the WD is kicked to velocities of a few hundred km s{sup -1}. These kicks may unbind the binary and eject a runaway/hypervelocity WD. Although the energy and ejected mass of the failed-detonation SN are a fraction of typical thermonuclear SNe, they are likely to appear as subluminous low-velocity SNe Ia. Such failed detonations might therefore explain or are related to the observed branch of peculiar SNe Ia, such as the family of low-velocity subluminous SNe (SN 2002cx/SN 2008ha-like SNe).

Jordan, George C. IV; Van Rossum, Daniel R. [Center for Astrophysical Thermonuclear Flashes, University of Chicago, Chicago, IL 60637 (United States); Perets, Hagai B. [Physics Department, Technion, Israel Institute of Technology, Haifa 32000 (Israel); Fisher, Robert T. [Department of Physics, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02740 (United States)

2012-12-20T23:59:59.000Z

396

He H`ike no ka Ho`opihapiha `ia o ka Pepa Noi Komo no ka Papahana Ho`omkaukau Kumu `iwi `o Kahuawaiola  

E-Print Network [OSTI]

45 a `oi ma ka pae 300 a ma luna a`e paha a e k ana n koina `lelo a mo`omeheu Hawai`i e helu `ia nei`omeheu Hawai`i. 7. ka puka `ana ma ho`okahi o n papa penei: HWST 205, 471, 472, 473, 474; a i `ole ka `ae a ka `ekolu kau kona l`ihi i kkulu `ia no ka ho`omkaukau `ana i n kumu Mauli Ola Hawai`i no ka ho`ona`auao ma

Wiegner, Tracy N.

397

Large linear magnetoresistance in a GaAs/AlGaAs heterostructure  

SciTech Connect (OSTI)

We report non-saturating linear magnetoresistance (MR) in a two-dimensional electron system (2DES) at a GaAs/AlGaAs heterointerface in the strongly insulating regime. We achieve this by driving the gate voltage below the pinch-off point of the device and operating it in the non-equilibrium regime with high source-drain bias. Remarkably, the magnitude of MR is as large as 500% per Tesla with respect to resistance at zero magnetic field, thus dwarfing most non-magnetic materials which exhibit this linearity. Its primary advantage over most other materials is that both linearity and the enormous magnitude are retained over a broad temperature range (0.3 K to 10 K), thus making it an attractive candidate for cryogenic sensor applications.

Aamir, Mohammed Ali, E-mail: aamir@physics.iisc.ernet.in; Goswami, Srijit, E-mail: aamir@physics.iisc.ernet.in; Ghosh, Arindam [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Baenninger, Matthias; Farrer, Ian; Ritchie, David A. [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Tripathi, Vikram [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Pepper, Michael [Department of Electrical and Electronic Engineering, University College, London WC1E 7JE (United Kingdom)

2013-12-04T23:59:59.000Z

398

Enhanced optical property in quaternary GaInAsSb/AlGaAsSb quantum wells  

SciTech Connect (OSTI)

High quality GaInAsSb/AlGaAsSb quantum wells (QWs) have been grown by molecular beam epitaxy using proper interface treatments. By controlling the group-V elements at interfaces, we obtained excellent optical quality QWs, which were free from undesired localized trap states, which may otherwise severely affect the exciton recombination. Strong and highly efficient exciton emissions up to room temperature with a wavelength of 2.2 ?m were observed. A comprehensive investigation on the QW quality was carried out using temperature dependent and power dependent photoluminescence (PL) measurements. The PL emission intensity remains nearly constant at low temperatures and is free from the PL quenching from the defect induced localized states. The temperature dependent emission energy had a bulk-like behavior, indicating high quality well/barrier interfaces. Because of the uniformity of the QWs and smooth interfaces, the low temperature limit of inhomogeneous line width broadening is as small as 5?meV.

Lin, Chien-Hung, E-mail: chlin.ee97g@g2.nctu.edu.tw; Lee, Chien-Ping [Department of Electronics Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

2014-10-21T23:59:59.000Z

399

Exciton recombination dynamics in InxGa1-xAs/GaAs quantum wells  

Science Journals Connector (OSTI)

Low-temperature decay times ?PL are reported for a series of InxGa1-xAs/GaAs quantum wells. These show a nearly linear increase with increasing thickness (4?Lz?10 nm, x=0.15) but recombination in the widest well (12 nm) is dominated by nonradiative effects. The decay time increases almost linearly with temperature up to 50 K, as expected for free excitons. An increase in ?PL with increasing In composition (0.05?x?0.25, Lz=8 nm) is also observed. Wells with different In compositions exhibit a similar temperature behavior and there is a weak influence of strain on the decay time. Additional peaks in the photoluminescence spectra occur to the low-energy side of the free-exciton peaks. These features, which exhibit longer decay times, are attributed to excitons localized in In-rich islands arising from indium segregation.

Haiping Yu; Christine Roberts; Ray Murray

1995-07-15T23:59:59.000Z

400

Sidewall passivation for InGaN/GaN nanopillar light emitting diodes  

SciTech Connect (OSTI)

We studied the effect of sidewall passivation on InGaN/GaN multiquantum well-based nanopillar light emitting diode (LED) performance. In this research, the effects of varying etch rate, KOH treatment, and sulfur passivation were studied for reducing nanopillar sidewall damage and improving device efficiency. Nanopillars prepared under optimal etching conditions showed higher photoluminescence intensity compared with starting planar epilayers. Furthermore, nanopillar LEDs with and without sulfur passivation were compared through electrical and optical characterization. Suppressed leakage current under reverse bias and four times higher electroluminescence (EL) intensity were observed for passivated nanopillar LEDs compared with unpassivated nanopillar LEDs. The suppressed leakage current and EL intensity enhancement reflect the reduction of non-radiative recombination at the nanopillar sidewalls. In addition, the effect of sulfur passivation was found to be very stable, and further insight into its mechanism was gained through transmission electron microscopy.

Choi, Won Hyuck; Abraham, Michael; Yu, Shih-Ying [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); You, Guanjun; Liu, Jie; Wang, Li; Xu, Jian, E-mail: jianxu@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Mohney, Suzanne E., E-mail: mohney@ems.psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2014-07-07T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Photovoltaic properties of GaAs:Be nanowire arrays  

SciTech Connect (OSTI)

Arrays of GaAs:Be nanowires are synthesized by molecular beam epitaxy on GaAs(111)B substrates. Prototypes of photovoltaic converters in which the grown nanowire arrays are used as active layers are produced by means of successive photolithography, etching, and metallization processes. Studying the photovoltaic properties of the fabricated structures using a solar radiation simulator demonstrates that the solarenergy conversion efficiency is about 0.1%. The value of the efficiency recalculated with the area occupied by the p-type nanowires on the surface of the n-type GaAs substrate taken into account amounts to 1.1%.

Bouravleuv, A. D.; Beznasyuk, D. V.; Gilstein, E. P. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Tchernycheva, M.; Luna Bugallo, A. De; Rigutti, L. [University Paris Sud 11, Institut d'Electronique Fondamentale UMR CNRS 8622 (France); Yu, L. [CNRS, Laboratoire de Physique des Interfaces et des Couches Minces (LPICM), Ecole Polytechnique (France); Proskuryakov, Yu. [University of Liverpool, Stephenson Institute for Renewable Energy (United Kingdom); Shtrom, I. V.; Timofeeva, M. A. [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Center (Russian Federation); Samsonenko, Yu. B.; Khrebtov, A. I.; Cirlin, G. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2013-06-15T23:59:59.000Z

402

Photocurrent Spectroscopy of Single Wurtzite GaAs Nanowires  

SciTech Connect (OSTI)

Photocurrent of single wurtzite GaAs nanowires grown by Au-assisted molecular beam epitaxy is measured at room and low temperature (10 K). At room temperature a high photo-response with more than two orders of magnitude increase of current is observed. The wavelength dependence of the photocurrent shows a sharp change near the zinc blende GaAs band gap. The absence of the free exciton peak in the low temperature photocurrent spectrum, and problems related to determining the exact position of the energy bandgap of wurtzite GaAs from the observed data are discussed.

Kim, D. C.; Ahtapodov, L.; Boe, A. B.; Moses, A. F.; Dheeraj, D. L.; Fimland, B. O.; Weman, H. [Department of Electronics and Telecommunications, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Choi, J. W.; Ji, H.; Kim, G. T. [School of Electrical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

2011-12-23T23:59:59.000Z

403

Effects of Ga ion-beam irradiation on monolayer graphene  

SciTech Connect (OSTI)

The effects of Ga ion on the single layer graphene (SLG) have been studied by Raman spectroscopy (RS), SEM, and field-effect characterization. Under vacuum conditions, Ga ion-irradiation can induce disorders and cause red shift of 2D band of RS, rather than lattice damage in high quality SLG. The compressive strain induced by Ga ion decreases the crystalline size in SLG, which is responsible for the variation of Raman scattering and electrical properties. Nonlinear out-put characteristic and resistance increased are also found in the I-V measurement. The results have important implications during CVD graphene characterization and related device fabrication.

Wang, Quan; Mao, Wei; Zhang, Yanmin; Shao, Ying; Ren, Naifei [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China)] [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Ge, Daohan [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China) [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2013-08-12T23:59:59.000Z

404

Electroreflectance study of effects of indium segregation in molecular-beam-epitaxy-grown InGaAs/GaAs  

Science Journals Connector (OSTI)

Electrolyte electroreflectance (EER) experiments were performed on In 0.22 Ga 0.78 As/GaAs single quantum wells grown by the conventional molecular-beam-epitaxy (MBE) shutter operation and also by modified MBE shutter operation intended to form more compositionally abrupt normal and inverted interfaces. The latter included controlled thermal desorption of the surface segregated In at the InGaAs layer surface (flash off) and the deposition of In at the InGaAs/GaAs interface to eliminate compositional broadening (predeposition). The fundamental energy gap and subband transitions were determined experimentally and compared with an accurate calculation of the potential well problem including strain. These results confirmed the segregation of In atoms near the interface. The segregation was maximum in the conventional (normal) MBE sample and least with the modified growth incorporating predeposition and flash off as expected. The segregated atoms are observed to act as dopants and form junctions near the InGaAs/GaAs interface. This study shows that EER can be used as an effective tool for studying the segregation process in MBE growth.

K. Chattopadhyay; J. Aubel; S. Sundaram; J. E. Ehret; R. Kaspi; Keith R. Evans

1997-01-01T23:59:59.000Z

405

The effect of CdS QDs structure on the InGaP/GaAs/Ge triple junction solar cell efficiency  

Science Journals Connector (OSTI)

This work describes optical and electrical characteristics of InGaP/GaAs/Ge triple-junction (T-J) solar cells with CdS quantum dots (QDs) ... quantum dot effectively enhance the overall power conversion efficiency

Chen-Chen Chung; Binh Tinh Tran; Hau-Vei Han; Yen-Teng Ho

2014-03-01T23:59:59.000Z

406

Improvement of orange ii photobleaching by moderate Ga3+ doping of titania and detrimental effect of structural disorder on Ga overloading  

Science Journals Connector (OSTI)

Highly photoactive Ga3+-doped anatase modification of titania was prepared by homogeneous hydrolysis of aqueous solutions mixture of titanium oxo-sulphate TiOSO4 and gallium(III) nitrate with urea. Incorporation of Ga3+ ...

Vclav tengl, Jil Henych, Michaela Slun, Tom Matys Grygar, Jana Velick, Martin Kormunda

2014-01-01T23:59:59.000Z

407

Kinetics of indirect photoluminescence in GaAs/AlxGa1?x As double quantum wells in a random potential with a large amplitude  

Science Journals Connector (OSTI)

The kinetics of indirect photoluminescence of GaAs/AlxGa1?x As double quantum wells, characterized by a random potential with a large amplitude (the linewidth of the indirect photoluminescence is ...

L. V. Butov; A. V. Mintsev; A. I. Filin

1999-05-01T23:59:59.000Z

408

Microscopic, electrical and optical studies on InGaN/GaN quantum wells based LED devices  

SciTech Connect (OSTI)

We report here on the micro structural, electronic and optical properties of a GaN-based InGaN/GaN MQW LED grown by the MOVPE method. The present study shows that the threading dislocations present in these LED structures are terminated as V pits at the surface and have an impact on the electrical and optical activity of these devices. It has been pointed that these dislocations were of edge, screw and mixed types. EBIC maps suggest that the electrically active defects are screw and mixed dislocations and behave as nonradiative recombinant centres.

Mutta, Geeta Rani; Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna [Department of Physics and Astronomy, University of Bologna, Viale Carlo Berti Pichat 6/II, 40127 Bologna (Italy); Meneghini, Matteo; Zanoni, Enrico; Meneghesso, Gaudenzio [University of Padova, Department of Information Engineering, via Gradenigo 6/B, Padova 35131 (Italy); Zhu, Dandan; Humphreys, Colin [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

2014-02-21T23:59:59.000Z

409

Structural and optical properties of GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells  

SciTech Connect (OSTI)

GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells are grown by laser-assisted sputtering. Structural and optical studies of the heterostructures are carried out. A broad photoluminescence line is observed in the wavelength range from 1300 to 1650 nm. The line corresponds to indirect transitions in the momentum space of the Ge quantum wells and to transitions between the In{sub 0.28}Ga{sub 0.72}As and Ge layers, indirect in coordinate space, but direct in momentum space.

Aleshkin, V. Ya.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Drozdov, M. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Nizhni Novgorod State University, Research Physical Technical Institute (Russian Federation); Kudryavtsev, K. E.; Tonkikh, A. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

2013-05-15T23:59:59.000Z

410

Time-resolved photoluminescence, positron annihilation, and Al0.23Ga0.77N/GaN heterostructure growth studies on low defect density polar and nonpolar freestanding GaN substrates grown by hydride vapor phase epitaxy  

Science Journals Connector (OSTI)

Time-resolved photoluminescence(TRPL) and positron annihilation measurements as well as Al0.23Ga0.77N/GaN heterostructuregrowth by metalorganic vapor phase epitaxy were carried out on very low defect density polar c-plane and nonpolar m-plane freestanding GaN (FS-GaN) substrates grown by hydride vapor phase epitaxy. Room-temperature photoluminescence(PL) lifetime for the near-band-edge (NBE) excitonic emission of the FS-GaN substrates increases with increasing positron diffusion length (L +); i.e. decreasing gross concentration of charged and neutral point defects and complexes. The best undoped c-plane FS-GaN exhibits record-long L + being 116?nm. The fast component of the PL lifetime for its NBE emission increases with temperature rise up to 100?K and levels off at approximately 1.1?ns. The result implies a saturation in thermal activation of nonradiative recombination centers. The surface and interface roughnesses for a Si-doped Al0.23Ga0.77N/GaN/Al0.18Ga0.82N/GaN heterostructure are improved by the use of FS-GaN substrates in comparison with the structure fabricated on a standard GaN template. The emission signals related to the recombination of a two-dimensional electron gas and excited holes are recognized for an Al0.23Ga0.77N/GaN single heterostructuregrown on the c-plane FS-GaN substrate.

S. F. Chichibu; K. Hazu; Y. Ishikawa; M. Tashiro; H. Namita; S. Nagao; K. Fujito; A. Uedono

2012-01-01T23:59:59.000Z

411

Polarization charges and polarization-induced barriers in AlxGa1xNGaN and InyGa1yNGaN heterostructures  

E-Print Network [OSTI]

N?GaN heterostructures L. Jia,a) E. T. Yu, D. Keogh, and P. M. Asbeck Department of Electrical and Computer EngineeringGa1 yN surrounded by n-GaN, capacitance­ voltage profiling studies combined with elementary will most likely require further improvements in p-type GaN conduc- tivity and fabrication of low-resistance

Yu, Edward T.

412

Elba Island, GA Natural Gas Liquefied Natural Gas Imports from...  

U.S. Energy Information Administration (EIA) Indexed Site

Egypt (Million Cubic Feet) Elba Island, GA Natural Gas Liquefied Natural Gas Imports from Egypt (Million Cubic Feet) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2011 5,780...

413

Lattice vibrations of pure and doped GaSe  

SciTech Connect (OSTI)

The Bridgman method is used to grow especially undoped and doped single crystals of GaSe. Composition and impurity content of the grown crystals were determined using X-ray fluorescence (XRF) method. X-ray diffraction, Raman scattering, photoluminescence (PL), and IR transmission measurements were performed at room temperature. The long wavelength lattice vibrations of four modifications of GaSe were described in the framework of modified one-layer linear-chain model which also takes into consideration the interaction of the selenium (Se) atom with the second nearest neighbor gallium (Ga) atom in the same layer. The existence of an eight-layer modification of GaSe is suggested and the vibrational frequencies of this modification are explained in the framework of a lattice dynamical model considered in the present work. Frequencies and the type of vibrations (gap, local, or resonance) for the impurity atoms were calculated and compared with the experimental results.

Allakhverdiev, K. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey) and Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan)]. E-mail: kerim.allahverdi@mam.gov.tr; Baykara, T. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Ellialtioglu, S. [Department of Physics, Middle East Technical University, Ankara 06531 (Turkey); Hashimzade, F. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Huseinova, D. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Kawamura, K. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan); Kaya, A.A. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Kulibekov, A.M. [Department of Physics, Mugla University, Mugla 48000 (Turkey); Onari, S. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan)

2006-04-13T23:59:59.000Z

414

GaAs solar cells close to the thermodynamic limit  

Science Journals Connector (OSTI)

The efficiency of GaAs solar cells can be increased by applying angularly selective filters. It is shown in terms of detailed balance model, why this happens and the concept is proven...

Hoehn, Oliver; Kraus, Tobias; Bauhuis, Gerard; Schwarz, Ulrich T; Blsi, Benedikt

415

Transverse acoustic actuation of Ni-Mn-Ga single crystals  

E-Print Network [OSTI]

Two methods for the transverse acoustic actuation of {110}-cut Ni-Mn-Ga single crystals are discussed. In this actuation mode, crystals are used that have the {110}- type twinning planes parallel to the base of the crystal. ...

Simon, Jesse Matthew

2007-01-01T23:59:59.000Z

416

Modeling of InGaN/Si tandem solar cells  

Science Journals Connector (OSTI)

We investigate theoretically the characteristics of monolithic InGaN/Si two-junction series-connected solar cells using the air mass 1.5 global irradiance spectrum. The addition of an InGaN junction is found to produce significant increases in the energy conversion efficiency of the solar cell over that of one-junction Si cells. Even when Si is not of high quality such two-junction cells could achieve efficiencies high enough to be practically feasible. We also show that further though smaller improvements of the efficiency can be achieved by adding another junction to form an InGaN/InGaN/Si three-junction cell.

L. Hsu; W. Walukiewicz

2008-01-01T23:59:59.000Z

417

Exciton front propagation in photoexcited GaAs quantum wells  

E-Print Network [OSTI]

We report on the study of spatiotemporal self-organization of carriers in photoexcited GaAs quantum wells. Propagating interfaces between electron-rich and hole-rich regions are seen as expanding and collapsing exciton ...

Yang, Sen

418

Evaporation-based Ge/.sup.68 Ga Separation  

DOE Patents [OSTI]

Micro concentrations of .sup.68 Ga in secular equilibrium with .sup.68 Ge in strong aqueous HCl solution may readily be separated in ionic form from the .sup.68 Ge for biomedical use by evaporating the solution to dryness and then leaching the .sup.68 Ga from the container walls with dilute aqueous solutions of HCl or NaCl. The chloro-germanide produced during the evaporation may be quantitatively recovered to be used again as a source of .sup.68 Ga. If the solution is distilled to remove any oxidizing agents which may be present as impurities, the separation factor may easily exceed 10.sup.5. The separation is easily completed and the .sup.68 Ga made available in ionic form in 30 minutes or less.

Mirzadeh, Saed (Albuquerque, NM); Whipple, Richard E. (Los Alamos, NM); Grant, Patrick M. (Los Alamos, NM); O'Brien, Jr., Harold A. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

419

Homogeneous AlGaN/GaN superlattices grown on free-standing (1100) GaN substrates by plasma-assisted molecular beam epitaxy  

SciTech Connect (OSTI)

Two-dimensional and homogeneous growth of m-plane AlGaN by plasma-assisted molecular beam epitaxy has been realized on free-standing (1100) GaN substrates by implementing high metal-to-nitrogen (III/N) flux ratio. AlN island nucleation, often reported for m-plane AlGaN under nitrogen-rich growth conditions, is suppressed at high III/N flux ratio, highlighting the important role of growth kinetics for adatom incorporation. The homogeneity and microstructure of m-plane AlGaN/GaN superlattices are assessed via a combination of scanning transmission electron microscopy and high resolution transmission electron microscopy (TEM). The predominant defects identified in dark field TEM characterization are short basal plane stacking faults (SFs) bounded by either Frank-Shockley or Frank partial dislocations. In particular, the linear density of SFs is approximately 5 10{sup ?5} cm{sup ?1}, and the length of SFs is less than 15 nm.

Shao, Jiayi; Malis, Oana [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States); Zakharov, Dmitri N. [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973 (United States); Edmunds, Colin [Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States)] [Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States); Manfra, Michael J. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 49707 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 49707 (United States)

2013-12-02T23:59:59.000Z

420

High-efficiency GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy  

Science Journals Connector (OSTI)

We report the initial results of GaAs and GaInP solar cells grown by all solid-state molecular- ... (MBE) technique. For GaAs single-junction solar cell, with the application of AlInP as ... back surface field la...

Shulong Lu; Lian Ji; Wei He; Pan Dai; Hui Yang

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Organometallic Vapor Phase Epitaxy of n-GaSb and n-GaInAsSb for Low Resistance Ohmic Contacts  

SciTech Connect (OSTI)

A comparison of n-GaSb and n-GaInAsSb epilayers for ohmic contacts in GaSb-based devices is studied. The epilayers were grown by organometallic vapor phase epitaxy and doped with Te. At similar electron concentrations, the atomic Te concentration, as determined by secondary ion mass spectroscopy, is more than 2 times higher in n-GaSb compared to n-GaInAsSb. In addition, the electron mobility is lower in n-GaSb than n-GaInAsSb at similar electron concentrations. The electron concentration saturates at about 1.3 x 10{sup 18} cm{sup -3} for n-GaSb, but linearly increases for n-GaInAsSb. Pd/Ge/Au/Pt/Au metallization was studied for ohmic contacts. A specific contact resistivity of 1 x 10{sup -5}{Omega}-cm{sup 2} for n-GaSb was measured. The specific contact resistivity can be greatly improved by contacting n-GaInAsSb, and a significantly lower specific contact resistivity of 2 x 10{sup -6} {Omega}-cm{sup 2} for n-GaInAsSb was measured.

C.A. Wang; D.A. Shiau; R.K. Huang; C.T. Harris; M.K. Connors

2003-07-10T23:59:59.000Z

422

60 GHz Harmonic Optoelectronic Up-Conversion Using an InAlAs/InGaAs Metamorphic High-Electron-Mobility Transistor on a GaAs Substrate  

E-Print Network [OSTI]

60 GHz Harmonic Optoelectronic Up-Conversion Using an InAlAs/InGaAs Metamorphic High optoelectronic up-conversion using an InAlAs/InGaAs metamorphic high-electron-mobility transistor (HEMT) on a Ga 1 GHz signals into a 60 GHz band. After investigating the dependences of optoelectronic mixing

Choi, Woo-Young

423

The crucial role of doping for high repetition rate monolithic mode locking of multiple quantum well GaAs/AlGaAs lasers  

E-Print Network [OSTI]

have been operated in GaAs/AlGaAs and InP/InGaAsP mul- tiple quantum well MQW materials showed no evidence of mode-locked operation. Band-edge absorption spectra are also presented which

424

Electronic properties of the Ga vacancy in GaP(110) surfaces determined by scanning tunneling microscopy  

Science Journals Connector (OSTI)

The electronic properties of uncharged Ga monovacancies in GaP(110) surfaces are determined from voltage-dependent scanning tunneling microscopy images. The signatures of localized defect states in the band gap are analyzed and their spatial location is determined. Empty and occupied defect states exist. Depressed dangling bonds in the occupied-state images indicate an inward relaxation of the neighboring P atoms. The results agree with recent theoretical work.

Ph. Ebert and K. Urban

1998-07-15T23:59:59.000Z

425

Microscopic identification of the compensation mechanisms in Si-doped GaAs  

Science Journals Connector (OSTI)

The compensation mechanisms of SiGa donors in GaAs are determined by scanning tunneling microscopy. With increasing Si concentration the SiGa donors are consecutively electrically deactivated by SiAs acceptors, Si clusters, and SiGa-Ga-vacancy complexes. A microscopic model based on the screened Coulomb interaction between charged dopants, the amphoteric nature of Si, and the Fermi-level effect is proposed. It explains the observed defects, the critical Si concentrations of each identified mechanism, and predicts the solubility limit of Si in GaAs. 1996 The American Physical Society.

C. Domke, Ph. Ebert, M. Heinrich, and K. Urban

1996-10-15T23:59:59.000Z

426

Suppression of nuclear spin diffusion at a GaAs/AlGaAs interface measured with a single quantum dot nano-probe  

E-Print Network [OSTI]

Nuclear spin polarization dynamics are measured in optically pumped individual GaAs/AlGaAs interface quantum dots by detecting the time-dependence of the Overhauser shift in photoluminescence (PL) spectra. Long nuclear polarization decay times of ~ 1 minute have been found indicating inefficient nuclear spin diffusion from the GaAs dot into the surrounding AlGaAs matrix in externally applied magnetic field. A spin diffusion coefficient two orders lower than that previously found in bulk GaAs is deduced.

A. E. Nikolaenko; E. A. Chekhovich; M. N. Makhonin; I. W. Drouzas; A. B. Vankov; J. Skiba-Szymanska; M. S. Skolnick; P. Senellart; A. Lemaitre; A. I. Tartakovskii

2009-01-15T23:59:59.000Z

427

A review of methods to match building energy simulation modelsto measured data  

E-Print Network [OSTI]

Younger W. Handbook of energy audits. 7th ed.. Lilburn, GA:for commercial building energy audits. 2nd ed. Atlanta, GA:B. Investment grade energy audit. In: Proceedings of the

Coakley, Daniel; Raftery, Paul; Keane, Marcus

2014-01-01T23:59:59.000Z

428

Liquid Crystalline Polymer (LCP) Based Lumped-Element Bandpass Filters for Multiple WirelessApplications'  

E-Print Network [OSTI]

, Inc., Atlanta, GA 30332, USA Abstract - This paper presents for the first time the design* *Schoolof Electrical Engineering, Georga Institute of Technology,Atlanta, GA 30332,USA **JacketMicro Devices the sides used as inpdoutput terminals thus minimizing radiation losses and EM1 interference, 2) using

Swaminathan, Madhavan

429

2196 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 53, NO. 6, JUNE 2005 Layout-Level Synthesis of RF Inductors and Filters  

E-Print Network [OSTI]

is with Jacket Micro Devices Inc., Atlanta, GA, 30308 USA. M. Swaminathan is with the Department of Electrical Devices Inc., Atlanta, GA, 30308 USA. Digital Object Identifier 10.1109/TMTT.2005.848782 factor and stripline configuration are within 5% of data obtained from electromagnetic (EM) simulations. For RF

Swaminathan, Madhavan

430

Persistent photoconductivity in AlGaN/GaN heterojunction channels caused by the ionization of deep levels in the AlGaN barrier layer  

SciTech Connect (OSTI)

Time-dependent responses of drain current (I{sub d}) in an AlGaN/GaN HEMT under UV (3.3 eV) and red (2.0 eV) light illumination have been studied at 300 K and 250 K. UV illumination enhances I{sub d} by about 10 %, indicating that the density of two-dimensional electrons is raised by about 10{sup 12} cm{sup ?2}. When UV light is turned off at 300 K, a part of increased I{sub d} decays quickly but the other part of increment is persistent, showing a slow decay. At 250 K, the majority of increment remains persistent. It is found that such a persistent increase of I{sub d} at 250 K can be partially erased by the illumination of red light. These photo-responses are explained by a simple band-bending model in which deep levels in the AlGaN barrier get positively charged by the UV light, resulting in a parabolic band bending in the AlGaN layer, while some potion of those deep levels are neutralized by the red light.

Murayama, H.; Akiyama, Y.; Niwa, R.; Sakashita, H.; Sakaki, H. [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511 (Japan); Kachi, T. [Toyota Central R and D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Sugimoto, M. [Toyota Motor Corporation, 543 Kirigahora, Nishihirose-cho, Toyota, Aichi 470-0309 (Japan)

2013-12-04T23:59:59.000Z

431

Lasing characteristics of GaSb/GaAs self-assembled quantum dots embedded in an InGaAs quantum well  

E-Print Network [OSTI]

Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico, New Mexico 87545 Received 26 February 2007; accepted 1 June 2007; published online 28 June 2007 intriguing optoelectronic device possibilities on GaAs substrates including lasers, detectors, or solar cells

Jalali. Bahram

432

Growth of Core?Shell Ga?GaN Nanostructures via a Conventional Reflux Method and the Formation of Hollow GaN Spheres  

Science Journals Connector (OSTI)

Gallium nitride (GaN) is an important III?V semiconductor with a wide direct band gap of ?3.4 eV. ... LiHMDS exhibits good solubility in TOA. ... The products were collected by centrifugation twice at 7000 rpm for 2 min in hexane, isopropanol, ethanol, and then deionized water. ...

Tz-Jun Kuo; Chi-Liang Kuo; Chun-Hong Kuo; Michael H. Huang

2009-02-05T23:59:59.000Z

433

Maskless lateral epitaxial overgrowth of GaN on sapphire  

SciTech Connect (OSTI)

The authors demonstrate a technique of lateral epitaxial overgrowth (LEO) of GaN, termed maskless LEO, in which no mask is deposited prior to LEO regrowth. Instead, a bulk (> 2 {micro}m) GaN layer on sapphire is selectively dry etched, leaving {approximately} 5 {micro}m-wide stripe mesas oriented in the <10{bar 1}0>{sub GaN} direction, with a 20 {micro}m period. These stripes serve as seeds for LEO GaN growth, which proceeds from the tops of the stripes and expands laterally, resulting in a T, or overhang, morphology. As for LEO over an SiO{sub 2} mask, significant defect reduction (from {approximately} 10{sup 9} cm{sup {minus}2} to {approximately} 10{sup 6} cm{sup {minus}2}) is observed in cross-sectional transmission electron microscopy (TEM). Atomic force microscopy of the top surface of the LEO GaN reveals that no threading dislocations with screw component terminate at the surfaces of laterally overgrown regions. X-ray diffraction measurements reveal that the wings exhibit a crystallographic tilt away from the seed regions in an azimuth perpendicular to the stripe direction; the tilt angle ({approximately} 0.4--0.5{degree}) is relatively independent of growth temperature and wing aspect ratio.

Fini, P.; Marchand, H.; Ibbetson, J.P.; Moran, B.; Zhao, L.; Denbaars, S.P.; Speck, J.S.; Mishra, U.K.

1999-07-01T23:59:59.000Z

434

Metal contacts on ZnSe and GaN  

SciTech Connect (OSTI)

Recently, considerable interest has been focused on the development of blue light emitting materials and devices. The focus has been on GaN and ZnSe, direct band gap semiconductors with bands gaps of 3.4 and 2.6 eV, respectively. To have efficient, reliable devices it is necessary to have thermally and electrically stable Ohmic contacts. This requires knowledge of the metal-semiconductor reaction behavior. To date few studies have investigated this behavior. Much information has accumulated over the years on the behavior of metals on Si and GaAs. This thesis provides new knowledge for the more ionic wide band gap semiconductors. The initial reaction temperatures, first phases formed, and phase stability of Pt, Pd, and Ni on both semiconductors were investigated. The reactions of these metals on ZnSe and GaN are discussed in detail and correlated with predicted behavior. In addition, comparisons are made between these highly ionic semiconductors and Si and GaAs. The trends observed here should also be applicable to other II-VI and III-Nitride semiconductor systems, while the information on phase formation and stability should be useful in the development of contacts for ZnSe and GaN devices.

Duxstad, K.J. [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1997-05-01T23:59:59.000Z

435

Corrosion-induced degradation of GaAs PHEMTs under operation in high humidity conditions  

E-Print Network [OSTI]

We have comprehensively investigated the degradation mechanism of AlGaAs/InGaAs pseudomorphic high-electron-mobility transistors (PHEMTs) under operation in high humidity conditions. PHEMTs degradation under high humidity ...

Hisaka, Takayuki

436

Site-controlled fabrication of Ga nanodroplets by focused ion beam  

SciTech Connect (OSTI)

Ga droplets are created by focused ion beam irradiation of GaAs surface. We report that ordered Ga droplets can be formed on the GaAs surface without any implantation damage. The droplets are characterized with bigger sizes than those droplets formed on damaged area. These aligned Ga droplets are formed via the migration of Ga atoms from ion irradiation area to the edge of undamaged GaAs surface and further nucleation into droplets. The morphological evolution and size distribution of these nanodroplets are investigated systematically with different beam irradiation time and incident angles. Based on this method, well positioned Ga nanodroplets, such as chains, are achieved by using focus ion beam patterning. The controllable assembly of droplets on undamaged semiconductor surface can be used to fabricate templates, to fabricate quantum structures and quantum devices by droplet epitaxy technique.

Xu, Xingliang; Wang, Zhiming M., E-mail: zhmwang@gmail.com [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Science, Beijing 100083 (China); Wu, Jiang; Li, Handong; Zhou, Zhihua [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Wang, Xiaodong [Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Science, Beijing 100083 (China)

2014-03-31T23:59:59.000Z

437

Nonlinear optical waveguides based on near-infrared intersubband transitions in GaN/AlN  

E-Print Network [OSTI]

. Hasama, "Subpicosecond saturation of intersubband absorption in (CdS/ZnSe)/BeTe quantum well waveguides. Cho, "Intersubband absorption at ~ 1.55 m in well- and modulation-doped GaN/AlGaN multiple quantum

438

Atomic-Level Study of Melting Behavior of GaN Nanotubes. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Melting Behavior of GaN Nanotubes. Atomic-Level Study of Melting Behavior of GaN Nanotubes. Abstract: Molecular dynamics simulations with a Stillinger-Weber potential have been...

439

Electric field engineering in GaN high electron mobility transistors  

E-Print Network [OSTI]

In the last few years, AlGaN/GaN high electron mobility transistors (HEMTs) have become the top choice for power amplification at frequencies up to 20 GHz. Great interest currently exists in industry and academia to increase ...

Zhao, Xu, S.M. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

440

Device-level thermal analysis of GaN-based electronics  

E-Print Network [OSTI]

Gallium nitride (GaN)-based microelectronics are one of the most exciting semiconductor technologies for high power density and high frequency electronics. The excellent electrical properties of GaN and its related alloys ...

Bagnall, Kevin Robert

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Structural ordering and interface morphology in symmetrically strained(GaIn)As/Ga(PAs) superlattices grown on off-oriented GaAs(100)  

Science Journals Connector (OSTI)

In this work we investigate the structural properties of symmetrically strained (GaIn)As/GaAs/Ga(PAs)/GaAs superlattices by means of x-ray diffraction, reciprocal-space mapping, and x-ray reflectivity. The multilayers were grown by metalorganic vapor-phase epitaxy on (001) GaAs substrates intentionally off-oriented towards one of the nearest ?110? directions. High-resolution triple-crystal reciprocal-space maps recorded for different azimuth angles in the vicinity of the (004) Bragg diffraction clearly show a double periodicity of the x-ray peak intensity that can be ascribed to a lateral and a vertical periodicity occurring parallel and perpendicular to the growth surface. Moreover, from the intensity modulation of the satellite peaks, a lateral-strain gradient within the epilayer unit cell is found, varying from a tensile to a compressive strain. Thus, the substrate off-orientation promotes a lateral modulation of the layer thickness (ordered interface roughness) and of the lattice strain, giving rise to laterally ordered macrosteps. In this respect, contour maps of the specular reflected beam in the vicinity of the (000) reciprocal lattice point were recorded in order to inspect the vertical and lateral interface roughness correlation. A semiquantitative analysis of our results shows that the interface morphology and roughness is greatly influenced by the off-orientation angle and the lateral strain distribution. Two mean spatial wavelengths can be determined, one corresponding exactly to the macrostep periodicity and the other indicating a further interface waviness along the macrosteps. The same spatial periodicities were found on the surface by atomic-force-microscopy images confirming the x-ray results and revealing a strong vertical correlation of the interfaces up to the outer surface.

C. Giannini; L. Tapfer; Y. Zhuang; L. De Caro; T. Marschner; W. Stolz

1997-02-15T23:59:59.000Z

442

THERMAL STUDY OF A GaN-BASED HEMT A Dissertation  

E-Print Network [OSTI]

of gallium-nitride (GaN) high-electron-mobility transistors (HEMTs) under bias conditions. An experimental

Sen, Mihir

443

Substrate-dependent wetting layer formation during GaN growth: Impact on the morphology of the films  

SciTech Connect (OSTI)

We have compared epitaxial growth of GaN films on 6H-SiC(0001)-({radical}(3)x{radical}(3))R30 deg. -Ga and on (0001)-sapphire. Predeposited Ga layers were nitrided by ion beam assisted molecular beam epitaxy. Whereas on SiC the initially deposited Ga covers the substrate surface completely, on sapphire only Ga droplets are present. The different distribution of the predeposited Ga affects the morphology of GaN significantly. Scanning electron microscopy and atomic force microscopy analysis of the grown films show that the complete wetting of the SiC substrate with Ga enhances finally the size and the flatness of GaN terraces and thus the quality of the film. X-ray photoelectron spectroscopy measurements reveal that metallic Ga resides also on top of the GaN films during the growth.

Sidorenko, A.; Peisert, H.; Neumann, H.; Chasse, T. [Universitaet Tuebingen, Institut fuer Physikalische und Theoretische Chemie, Auf der Morgenstelle 8, D-72076 Tuebingen (Germany); Leibniz-Institut fuer Oberflaechenmodifizierung e.V. Permoserstrasse 15, D-04318 Leipzig (Germany); Universitaet Tuebingen, Institut fuer Physikalische und Theoretische Chemie, Auf der Morgenstelle 8, D-72076 Tuebingen (Germany)

2007-08-15T23:59:59.000Z

444

Doping and isolation of GaN, InGaN and InAlN using ion implantation  

SciTech Connect (OSTI)

Both n- and p-type doping have been achieved in GaN using Si{sup +} or Mg{sup +}/P{sup +} implantation, respectively, followed annealing at {ge} 1050{degrees}C. Using proximity rapid thermal annealing (10sec) the GaN surface retains both smooth morphology and its original stoichiometry. Variable temperature Hall measurements reveal approximate energy levels of 62meV for the implanted Si and 171meV for the Mg, which are similar to their values in epitaxially grown GaN. Implant isolation of both n- and p-type GaN, and n-type In{sub 0.75}Al{sub 0.25}N with multiple energy inert species (e.g. N{sup +} or F{sup +}) produces high resistivity ({ge}10{sup 8}{omega}/{open_square}) after subsequent annealing in the range 600-700{degrees}C. Smaller increases in sheet resistance are observed for In{sub x}Ga{sup 1-x}N (x=0.33-0.75) under the same conditions due to the smaller energy bandgaps and the shallower energy levels of the damage-related states controlling the resistivity.

Pearton, S.J.; Vartuli, C.B.; Abernathy, C.R. [Univ. of Florida, Gainesville, FL (United States)] [and others

1995-08-01T23:59:59.000Z

445

Simulation of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors performances: Limiting factors and optimum design  

SciTech Connect (OSTI)

The performance capabilities of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors have been investigated by using a drift-diffusion transport model. Numerical results have been employed to study the effect of the p-type Mg doping and its incomplete ionization on device performance. The high base resistance induced by the deep acceptor level is found to be the cause of limited current gain values for Npn devices. Several computation approaches have been considered to improve their performance. Reasonable improvement of the DC current gain {beta} is observed by realistically reducing the base thickness in accordance with processing limitations. Base transport enhancement is also predicted by the introduction of a quasi-electric field in the base. The impact of the base resistivity on high-frequency characteristics is investigated for Npn AlGaN/GaN devices. Optimized predictions with maximum oscillation frequency value as high as f{sub MAX} = 20 GHz and a unilateral power gain--U = 25 dB make this bipolar GaN-based technology compatible with communication applications. Simulation results reveal that the restricted amount of free carriers from the p-doped emitter limits Pnp's DC performances operating in common emitter configuration. A preliminary analysis of r.f. characteristics for the Pnp counterpart indicates limited performance mainly caused by the degraded hole mobility.

MONIER,C.; REN,F.; HAN,JUNG; CHANG,PING-CHIH; SHUL,RANDY J.; LEE,K.P.; ZHANG,A.P.; BACA,ALBERT G.; PEARTON,S.J.

2000-04-25T23:59:59.000Z

446

Spin dependent transport properties of Mn-Ga/MgO/Mn-Ga magnetic tunnel junctions with metal(Mg, Co, Cr) insertion layer  

SciTech Connect (OSTI)

We report a first principles theoretical investigation of spin polarized quantum transport in Mn{sub 2}Ga/MgO/Mn{sub 2}Ga and Mn{sub 3}Ga/MgO/Mn{sub 3}Ga magnetic tunneling junctions (MTJs) with the consideration of metal(Mg, Co, Cr) insertion layer effect. By changing the concentration of Mn, our calculation shows a considerable disparity in transport properties: A tunneling magnetoresistance (TMR) ratio of 852% was obtained for Mn{sub 2}Ga-based MTJs, however, only a 5% TMR ratio for Mn{sub 3}Ga-based MTJs. In addition, the influence of insertion layer has been considered in our calculation. We found the Co insertion layer can increase the TMR of Mn{sub 2}Ga-based MTJ to 904%; however, the Cr insertion layer can decrease the TMR by 668%; A negative TMR ratio can be obtained with Mg insertion layer. Our work gives a comprehensive understanding of the influence of different insertion layer in Mn-Ga based MTJs. It is proved that, due to the transmission can be modulated by the interfacial electronic structure of insertion, the magnetoresistance ratio of Mn{sub 2}Ga/MgO/Mn{sub 2}Ga MTJ can be improved by inserting Co layer.

Liang, S. H.; Tao, L. L.; Liu, D. P., E-mail: dpliu@iphy.ac.cn; Han, X. F., E-mail: xfhan@iphy.ac.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Lu, Y. [Institut Jean Lamour, UMR 7198, CNRS-Nancy Universit, BP 239, 54506 Vandoeuvre (France)

2014-04-07T23:59:59.000Z

447

Novel photoaffinity ligands for the GA-receptor  

SciTech Connect (OSTI)

Previous studies from this laboratory have shown that certain N-substituted phthalimides (NSPs) exhibit GA-like activity in a range of specific bioassays and that bioactive NSPs compete with ({sup 3}H)-GA{sub 4} for soluble binding sites in cucumber homogenates. As such, these compounds may prove useful in the purification and characterization of GA receptor proteins. To this end, five azido-NSPs have been synthesized and are currently being screened for biological activity and photochemical stability. Three azido-NSPs elicit {alpha}-amylase production in barley half-seeds and stimulate tissue elongation in d{sub 5} maize, lettuce, sunflower, and soybean. Further evaluations are in progress and these data as well as the utility of these compounds as photo-affinity ligands will be discussed.

Suttle, J.C.; Hultstrand, J.F.; Tanaka, F.S. (USDA/ARS Biosciences Research Laboratory, Fargo, ND (USA))

1990-05-01T23:59:59.000Z

448

The polygallides: Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub2}.  

SciTech Connect (OSTI)

Yb{sub 3}Ga{sub 7}Ge{sub 3} and YbGa{sub 4}Ge{sub 2} were obtained from reactions of Yb and Ge in excess liquid gallium. The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} was refined using X-ray and neutron diffraction data on selected single crystals. Yb{sub 3}Ga{sub 7}Ge{sub 3} crystallizes in the monoclinic space group C2/c with lattice constants a = 12.2261(20) {angstrom}, b = 10.7447(20) {angstrom}, c = 8.4754(17) {angstrom} and {beta} = 110.288(30){sup o} (neutron diffraction data). The crystal structure of Yb{sub 3}Ga{sub 7}Ge{sub 3} is an intergrowth of planar layers of YbGa{sub x}Ge{sub y} and puckered layers of (Ge)n. YbGa{sub 4}Ge{sub 2} crystallizes in a modified PuGa{sub 6} structure type in the tetragonal polar space group I4cm with lattice constants a = b = 5.9874(6) {angstrom} and c = 15.1178(19) {angstrom}. The structure of YbGa{sub 4}Ge{sub 2} is an intergrowth of puckered Ga layers and puckered Ga{sub x}Ge{sub y} layers with Yb atoms residing within the channels formed by the connection of the two layers. Physical properties, resistivity ({rho}), magnetic susceptibility ({chi}) and specific heat (C) were measured for Yb{sub 3}Ga{sub 7}Ge{sub 3}. No magnetic ordering was observed. It was found that at low temperatures, {rho} varied as T{sup 2} and C{alpha}T, indicating Fermi-liquid regime in Yb{sub 3}Ga{sub 7}Ge{sub 3} at low temperatures.

Peter, S. C.; Malliakas, C. D.; Nakotte, H.; Kothapilli, K.; Rayaprol, S.; Schultz, A. J.; Kanatzidis, M. G. (Materials Science Division); ( XSD); (Northwestern Univ.); (Jawaharlal Nehru Centre for Adv. Sci. Res.); (New Mexico State Univ.); (Los Alamos Nat. Lab.); (UGC-DAE Consortium for Sci. Res.)

2012-03-01T23:59:59.000Z

449

Invited Paper GaAs/A1O photonic bandgap material fabrication and characterization  

E-Print Network [OSTI]

semiconductor crystals, photonic crystals do not occur naturally. There are, therefore, several seemingly direct bandgap semiconductors, such as GaAs, A1GaAs, InP, InGaAsP, etc., in which the radiative-dimensional photonic bandgaps for microwave and millimeter-wave radiation, and for shorter optical wavelengths in one

Zhou, Weidong

450

Drift dominated InP/GaP photodiodes Yanning Sun a,*, Aristo Yulius a  

E-Print Network [OSTI]

Drift dominated InP/GaP photodiodes Yanning Sun a,*, Aristo Yulius a , Guohua Li b , Jerry MP photodiodes fabricated on GaP substrate with unique drift dominated design, which can build an electric field throughout the active region by varying the doping concentration. The InP/GaP photodiodes have been grown

Woodall, Jerry M.

451

DISSERTATION DEVICE PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS  

E-Print Network [OSTI]

DISSERTATION DEVICE PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Submitted by Markus Gloeckler PHYSICS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS BE ACCEPTED AS FULFILLING IN PART REQUIREMENTS OF Cu(In,Ga)Se2 THIN-FILM SOLAR CELLS Thin-film solar cells have the potential to be an important

Sites, James R.

452

Free carrier induced spectral shift for GaAs filled metallic hole arrays  

E-Print Network [OSTI]

. Soref, and J. A. D. Alamo, "Carrier-induced change in refractive index of InP, GaAs, and InGaAsP," IEEE-photon absorption (3PA) assisted by strongly enhanced local fields, reduce the refractive index of GaAs in ~200-nm thick active area through band filling and free carrier absorption. Therefore, the surface plasma wave

New Mexico, University of

453

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy  

E-Print Network [OSTI]

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy A. J. Ptak, L. J-assisted molecular-beam epitaxy to study the dependence of oxygen incorporation on polarity and oxygen partial pressure. Oxygen incorporates at a rate ten times faster on nitrogen-polar GaN than on the Ga polarity

Myers, Tom

454

Testing Models of Intrinsic Brightness Variations in Type Ia Supernovae, and their Impact on Measuring Cosmological Parameters  

E-Print Network [OSTI]

For spectroscopically confirmed type Ia supernovae we evaluate models of intrinsic brightness variations with detailed data/Monte-Carlo comparisons of the dispersion in the following quantities: Hubble-diagram scatter, color difference (B-V-c) between the true B-V color and the fitted color (c) from the SALT-II light curve model, and photometric redshift residual. The data sample includes 251 ugriz light curves from the 3-season Sloan Digital Sky Survey-II, and 191 griz light curves from the Supernova Legacy Survey 3-year data release. We find that the simplest model of a wavelength independent (coherent) scatter is not adequate, and that to describe the data the intrinsic scatter model must have wavelength-dependent variations. We use Monte Carlo simulations to examine the standard approach of adding a coherent scatter term in quadrature to the distance-modulus uncertainty in order to bring the reduced chi2 to unity when fitting a Hubble diagram. If the light curve fits include model uncertainties with the c...

Kessler, Richard; Marriner, John; Betoule, Marc; Brinkmann, Jon; Cinabro, David; El-Hage, Patrick; Frieman, Joshua; Jha, Saurabh; Mosher, Jennifer; Schneider, Donald P

2012-01-01T23:59:59.000Z

455

GA Hot Cell D&D Closeout Report  

Office of Legacy Management (LM)

GENERAL ATOMICS GENERAL ATOMICS HOT CELL FACILITY DECONTAMINATION & DECOMMISSIONING PROJECT FINAL PROJECT CLOSEOUT REPORT prepared for GA HOT CELL D&D PROJECT CONTRACT NUMBERS DE-AC03-84SF11962 and DE-AC03-95SF20798 PBS VL-GA-0012 Approvals Prepared by: James Davis, III Date Project Manager, Oakland Environmental Programs Office Reviewed by: John Lee Date Deputy, Oakland Environmental Programs Office Approved by: Laurence McEwen Date Acting Director, Oakland Environmental Programs Office General Atomics Hot Cell Facility D&D Project Closeout Report Contents Page i CONTENTS CONTENTS.....................................................................................................................................

456

Simple intrinsic defects in GaAs : numerical supplement.  

SciTech Connect (OSTI)

This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.

Schultz, Peter Andrew

2012-04-01T23:59:59.000Z

457

Surface morphology and magnetic anisotropy in (Ga,Mn)As  

E-Print Network [OSTI]

Atomic Force Microscopy and Grazing incidence X-ray diffraction measurements have revealed the presence of ripples aligned along the $[1\\bar{1}0]$ direction on the surface of (Ga,Mn)As layers grown on GaAs(001) substrates and buffer layers, with periodicity of about 50 nm in all samples that have been studied. These samples show the strong symmetry breaking uniaxial magnetic anisotropy normally observed in such materials. We observe a clear correlation between the amplitude of the surface ripples and the strength of the uniaxial magnetic anisotropy component suggesting that these ripples might be the source of such anisotropy.

S. Piano; X. Marti; A. W. Rushforth; K. W. Edmonds; R. P. Campion; O. Caha; T. U. Schulli; V. Holy; B. L. Gallagher

2010-10-01T23:59:59.000Z

458

Operating experience with a GaAs photoemission electron source  

SciTech Connect (OSTI)

We report on the development of several operating procedures that promise to make GaAs photoemission electron sources easier to construct, more reliable to operate, and more amenable to use in dynamic vacuum systems. We describe in particular a method for ''ohmically'' heating a <100> crystal of GaAs under vacuum to approximately 600 /sup 0/C. We also discuss our observations of the role of oxygen in the activation of the crystal surface, the use of continuous cesiation, and of the performance of the crystal under varying vacuum conditions.

Tang, F.C.; Lubell, M.S.; Rubin, K.; Vasilakis, A.; Eminyan, M.; Slevin, J.

1986-12-01T23:59:59.000Z

459

An investigation on reliable passivation of GaP  

E-Print Network [OSTI]

reports the results of a study of sputtered Silicon Nitride 3N4) and Anodic Oxide as passivating techniques for Gallium Phosphide. Anodic Oxide was grown on GaP by anodizing the semiconductor in 30% hydrogen peroxide. The resulting oxide had an index... reports the results of a study of sputtered Silicon Nitride 3N4) and Anodic Oxide as passivating techniques for Gallium Phosphide. Anodic Oxide was grown on GaP by anodizing the semiconductor in 30% hydrogen peroxide. The resulting oxide had an index...

Greaves King, Carlos A.

2012-06-07T23:59:59.000Z

460

Interband transitions in molecular?beam?epitaxial Al x Ga1?x As/GaAs  

Science Journals Connector (OSTI)

Interband transition energies for Al x Ga1?x As layers grown by molecular?beam epitaxy(MBE) techniques have been determined using the electrolyte electroreflectance (EER) technique. The observed data fit quadratic relations for E 0 E 0+?0 E 1 and E 1+?1 to describe variations of energy with composition. Although the x values were not accurately known the internal consistency of the data is excellent. Given a single bowing parameter we show that accurate values of x can be determined. The EER technique can provide x values with an accuracy better than 0.02 and information on changes in x as small as 0.002. It is thus ideally suited for studying MBE materials.

J. L. Aubel; U. K. Reddy; S. Sundaram; W. T. Beard; James Comas

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ga atlanta ia" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Ultralow damage depth by electron cyclotron resonance plasma etching of GaAs/InGaAs quantum wells  

Science Journals Connector (OSTI)

Dry etch induced damage of GaAs/InGaAs/GaAs heterostructures in an electron cyclotron resonance (ECR) argon discharge has been investigated as a function of additional radio frequency self?biasing of the sample and process pressure in argon ECR discharges. We used depth resolved photoluminescence measurements to determine the influence of the etch process on the samples. We observe a decreasing damage depth for smaller bias voltages reaching its lowest value of 1.7 nm at 20 V bias and a pressure of 0.15 Pa. For lower pressures we observe a strong increase of the damage which is attributed predominantly to high energetic vacuum ultraviolet radiation from the ECR region.

T. Bickl; B. Jacobs; J. Straka; A. Forchel

1993-01-01T23:59:59.000Z

462

High-performance broadband optical coatings on InGaN/GaN solar cells for multijunction device integration  

SciTech Connect (OSTI)

We demonstrate InGaN/GaN multiple quantum well solar cells grown by metalorganic chemical vapor deposition on a bulk (0001) substrate with high-performance broadband optical coatings to improve light absorption. A front-side anti-reflective coating and a back-side dichroic mirror were designed to minimize front surface reflections across a broad spectral range and maximize rear surface reflections only in the spectral range absorbed by the InGaN, making the cells suitable for multijunction solar cell integration. Application of optical coatings increased the peak external quantum efficiency by 56% (relative) and conversion efficiency by 37.5% (relative) under 1 sun AM0 equivalent illumination.

Young, N. G., E-mail: ngyoung@engineering.ucsb.edu; Farrell, R. M.; Iza, M.; Speck, J. S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Perl, E. E.; Keller, S. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); Bowers, J. E.; Nakamura, S.; DenBaars, S. P. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

2014-04-21T23:59:59.000Z

463

Strong enhancement of terahertz emission from GaAs in InAs/GaAs quantum dot structures  

SciTech Connect (OSTI)

We report on the intense terahertz emission from InAs/GaAs quantum dot (QD) structures grown by molecular beam epitaxy. Results reveal that the QD sample emission was as high as 70% of that of a p-type InAs wafer, the most intense semiconductor emitter to date. Excitation wavelength studies showed that the emission was due to absorption in strained undoped GaAs, and corresponds to a two order-of-magnitude enhancement. Moreover, it was found that multilayer QDs emit more strongly compared with a single layer QD sample. At present, we ascribe the intense radiation to huge strain fields at the InAs/GaAs interface.

Estacio, Elmer; Pham, Minh Hong; Takatori, Satoru; Cadatal-Raduban, Marilou; Nakazato, Tomoharu; Shimizu, Toshihiko; Sarukura, Nobuhiko [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Somintac, Armando; Defensor, Michael; Awitan, Fritz Christian B.; Jaculbia, Rafael B.; Salvador, Arnel [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Garcia, Alipio [Department of Physical Sciences, University of the Philippines, Baguio City 2600 (Philippines)

2009-06-08T23:59:59.000Z

464

Ga-assisted catalyst-free growth mechanism of GaAs nanowires by molecular beam epitaxy  

Science Journals Connector (OSTI)

The mechanisms of Ga-assisted GaAs nanowires grown by molecular beam epitaxy are addressed. The axial and radial growth rates as a function of the Ga rate and As pressure indicate that on the opposite of what is observed in thin film epitaxy, the growth rate of the nanowires is arsenic limited. As a consequence, the axial growth rate of the wires can be controlled by the As4 pressure. Additionally, due to the small As4 pressure leading to nanowire growth, the deposition on the facets is very slow, leading to a much lower radial growth rate. Finally, we present a model that is able to accurately describe the presented observations and predicts a maximum length of nontapered nanowires of 40?m.

C. Colombo; D. Spirkoska; M. Frimmer; G. Abstreiter; A. Fontcuberta i Morral

2008-04-28T23:59:59.000Z

465

Carrier effective masses in symmetrically strained (GaIn)As/Ga(PAs) multiple-quantum-well structures  

Science Journals Connector (OSTI)

The carrier effective masses in symmetrically strained (GaIn)As/Ga(PAs) multiple-quantum-well heterostructures have been determined as a function of the incorporated compressive strain in the (GaIn)As quantum-well layer by applying magneto-optical studies. The precise structural parameters, i.e., individual layer thicknesses, strain values, and crystalline perfection, have been determined independently by high-resolution x-ray diffraction and transmission electron microscopy. By analyzing both the allowed and forbidden optical transitions as a function of the magnetic field, detected by polarization-dependent magnetophotoluminescence excitation spectroscopy, the exciton binding energy as well as the effective in-plane electron and heavy-hole masses have been determined quantitatively as a function of strain. The theoretically predicted significant decrease of the in-plane heavy-hole mass with increasing strain has been observed. The obtained results are discussed and compared with the contradictory results reported in the literature.

M. Volk; S. Lutgen; T. Marschner; W. Stolz; E. O. Gbel; P. C. M. Christianen; J. C. Maan

1995-10-15T23:59:59.000Z

466

Determination of subband energies and 2DEG characteristics of Al{sub x}Ga{sub 1?x}N/GaN heterojunctions using variational method  

SciTech Connect (OSTI)

A physics-based model based on the variational method for analyzing the two dimensional electron gas (2DEG) characteristics of polar AlGaN/GaN heterojunctions is developed. The 2DEG carrier concentration, the first and second energy subbands, and the position of the Fermi energy level are calculated for various barrier thicknesses, Al mole fractions, background dopant concentrations, and gate voltages for gated AlGaN/GaN heterojunctions. The results are in good agreement with the data reported based on self-consistent method. Whereas the aforementioned report has dealt with specific values of Al mole fraction, barrier thickness, and unintentional doping level, the present work provides a basis for calculating the 2DEG characteristics for the full range of these parameters. Furthermore, according to the proposed model, the applicability of the triangular approximation of the quantum well in AlGaN/GaN heterojunctions is evaluated.

Manouchehri, Farzin; Valizadeh, Pouya; Kabir, M. Z., E-mail: kabir@encs.concordia.ca [Department of Electrical and Computer Engineering, Concordia University, Montreal, H3G 1M8 (Canada)

2014-03-15T23:59:59.000Z

467

InGaAs heterostructure formation in catalyst-free GaAs nanopillars by selective-area metal-organic vapor phase epitaxy  

SciTech Connect (OSTI)

We investigate axial GaAs/InGaAs/GaAs heterostructures embedded in GaAs nanopillars via catalyst-free selective-area metal-organic chemical vapor deposition. Structural characterization by transmission electron microscopy with energy dispersive x-ray spectroscopy (EDS) indicates formation of axial In{sub x}Ga{sub 1-x}As (x{approx}0.20) inserts with thicknesses from 36 to 220 nm with {+-}10% variation and graded Ga:In transitions controlled by In segregation. Using the heterointerfaces as markers, the vertical growth rate is determined to increase linearly during growth. Photoluminescence from 77 to 290 K and EDS suggest the presence of strain in the shortest inserts. This capability to control the formation of axial nanopillar heterostructures is crucial for optimized device integration.

Shapiro, J. N.; Lin, A.; Wong, P. S.; Scofield, A. C.; Tu, C.; Senanayake, P. N.; Mariani, G.; Liang, B. L.; Huffaker, D. L. [Department of Electrical Engineering and California Nano-Systems Institute, University of California at Los Angeles, Los Angeles, California 90095 (United States)

2010-12-13T23:59:59.000Z

468

Tunneling and nonlinear transport in a vertically coupled GaAs/AlGaAs double quantum wire system.  

SciTech Connect (OSTI)

We report low-dimensional tunneling in an independently contacted vertically coupled quantum wire system. This nanostructure is fabricated in a high quality GaAs/AlGaAs parallel double quantum well heterostructure. Using a unique flip chip technique to align top and bottom split gates to form low-dimensional constrictions in each of the independently contacted quantum wells we explicitly control the subband occupation of the individual wires. In addition to the expected two-dimensional (2D)-2D tunneling results, we have found additional tunneling features that are related to the one-dimensional quantum wires.

Seamons, John Andrew; Lilly, Michael Patrick; Reno, John Louis; Bielejec, Edward Salvador

2004-11-01T23:59:59.000Z

469

Structure of negatively charged muonium in n-type GaAs  

Science Journals Connector (OSTI)

Muon level-crossing resonance and muon-spin-rotation measurements on heavily doped n-type GaAs:Si and GaAs:Te show that the majority of positive muons implanted at room temperature form an isolated diamagnetic muonium center located at a high-symmetry site with Ga neighbors along the ?111? direction(s). These experiments, together with theoretical considerations, imply that negatively charged muonium is at or near the tetrahedral interstitial site with four Ga nearest-neighbor atoms. Except for zero-point energy differences, these results should model negatively charged isolated hydrogen in GaAs.

K.H. Chow; R.F. Kiefl; W.A. MacFarlane; J.W. Schneider; D.W. Cooke; M. Leon; M. Paciotti; T.L. Estle; B. Hitti; R.L. Lichti; S.F.J. Cox; C. Schwab; E.A. Davis; A. Morrobel-Sosa; L. Zavieh

1995-05-15T23:59:59.000Z

470

Metal-insulator-semiconductor structures on p-type GaAs with low interface state density  

E-Print Network [OSTI]

Metal-insulator-semiconductor structures on p-type GaAs with low interface state density Zhi Chen properties of in situ deposited Si3N4 /Si/p-GaAs metal-insulator-semiconductor structures have been offered by a low gate leakage technology in GaAs, such as metal insulator structures, func- tional Ga

Chen, Zhi

471

INCREASED CELL EFFICIENCY IN InGaAs THIN FILM SOLAR CELLS WITH DIELECTRIC AND METAL BACK REFLECTORS  

E-Print Network [OSTI]

INCREASED CELL EFFICIENCY IN InGaAs THIN FILM SOLAR CELLS WITH DIELECTRIC AND METAL BACK REFLECTORS solar cells using back reflectors. We studied absorption enhancement in InGaAs and InGaAsP thin film and metal, on InGaAs thin film solar cell performance by device modeling and nu- merical simulations. DEVICE

Atwater, Harry

472

Optical phonon modes in InGaN/GaN dot-in-a-wire heterostructures grown by molecular beam epitaxy  

SciTech Connect (OSTI)

We report on the studies of optical phonon modes in nearly defect-free GaN nanowires embedded with intrinsic InGaN quantum dots by using oblique angle transmission infrared spectroscopy. These phonon modes are dependent on the nanowire fill-factor, doping densities of the nanowires, and the presence of InGaN dots. These factors can be applied for potential phonon based photodetectors whose spectral responses can be tailored by varying a combination of these three parameters. The optical anisotropy along the growth (c-) axis of the GaN nanowire contributes to the polarization agility of such potential photodetectors.

Titus, J.; Perera, A. G. U. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)] [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States); Nguyen, H. P. T.; Mi, Z. [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada)] [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada)

2013-03-25T23:59:59.000Z