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Sample records for proceedings washington dc

  1. Arms control in space: workshop proceedings, Washington, DC, January 30-31, 1984

    International Nuclear Information System (INIS)

    1984-05-01

    In late 1982 and early 1983, the Subcommittee on Arms Control, Oceans, International Operations, and Environment of the Senate Committee on Foreign Relations held hearings on space weapons and arms control. To explore these issues further in a discussion format not easily achieved in hearings, Sen. Larry Pressler, Chairman of the Subcommittee, asked OTA to conduct a workshop focusing on antisatellite (ASAT) weapons as one aspect of space arms control. The workshop held in Washington, DC on January 30 and 31, 1984, provided an opportunity for technical, diplomatic, military, and policy-analysis experts to interact, think out loud, and build each other's ideas. The workshop was organized into six sessions, although issues involving anti-satellite weapons and arms control are not easily compartmentalized into distinct subject areas. Each session was introduced by a 10- or 15-minute informal oral presentation which set the stage for further discussion. This workshop proceedings volume is organized along the same divisions as the sessions, with some rearrangement

  2. Problems of Journalism; Proceedings of the 1975 Annual Convention of the American Society of Newspaper Editors (Washington, D.C., April 16-18, 1975).

    Science.gov (United States)

    American Society of Newspaper Editors, Easton, PA.

    This document reports the 1975 proceedings of the American Society of Newspaper Editors (ASNE) convention held in Washington, D.C., April 16-18. The contents include a list of officers and directors, past presidents of the society, and a copy of the ASNE Code of Ethics. Also contained in the document are reports on such individual sessions as…

  3. Drunk Driving. Surgeon General's Workshop. Proceedings (Washington, D.C., December 14-16, 1988).

    Science.gov (United States)

    Janus Associates.

    This volume presents solutions, recommendations, and strategies in eleven interrelated areas considered at the Surgeon General's Workshop on Drunk Driving held in Washington, D.C. in December of 1988. Lists of the members of the Workshop Planning Committee and members of the federal advisory group on follow-up activities for the workshop are…

  4. Trends and determinants of cycling in the Washington, DC region.

    Science.gov (United States)

    2011-01-01

    This report analyzes cycling trends, policies, and commuting in the Washington, DC area. The analysis is divided into two parts. : Part 1 focuses on cycling trends and policies in Washington (DC), Alexandria (VA), Arlington County (VA), Fairfax Count...

  5. Summary Proceedings of the Future Navigation Systems Planning Conference, held 3-4 August 1982, Washington, DC.

    Science.gov (United States)

    1982-09-01

    U.S. civil system managed by the civil administration, but it would be even easier if it were a system agreed to and Jointly financed by ICAO or some... Unicorns Park Drive 955 L’Enfant Plaza Woburn, MA 01801 Washington, D.C. 20024 84 r. C. Dennis Wright Aircraft Owners & Pilots Association P.O. Box 5800

  6. Proceedings of the 1993 Particle Accelerator Conference Held in Washington, DC on May 17-20, 1993. Volume 2

    Science.gov (United States)

    1993-05-20

    Shapiro, S. Bethke, 0. Chamberlain, R. Fuzesy, M. Kowitt, D. Pripstein, B. Schumm, H. Steiner , M. Zolotorev, LBL; P. Rowson, Columbia; D. Blockus, H...Conference Proceedings, March 1989. 2. Rudolf P. Sevems, and Gordon E. Bloom, "Modern DC- to-DC Switchmode Power Converter Circuits," Van Nostrand...R. E. 2471 Steiner , H. 2172 Sytnikov, V. 2769 Thevenot, M. 670, 697 Steinhauer. L. C. 2564, 2581, Thiagarajan, V. 3372 2614 Thieberger, P. 3178

  7. Flavonoids and heart health: Proceedings of the ILSI North America Flavonoids Workshop may 31-june 1, 2005, Washington DC

    NARCIS (Netherlands)

    Erdman, J.W.; Balentine, D.; Arab, L.; Beecher, G.; Dwyer, J.T.; Folts, J.; Harnly, J.; Hollman, P.C.H.; Keen, C.L.; Mazza, G.; Messina, M.; Scalbert, A.; Vita, J.; Williamson, G.; Burrows, J.

    2007-01-01

    This article provides an overview of current research on flavonoids as presented during a workshop entitled, "Flavonoids and Heart Health," held by the ILSI North America Project Committee on Flavonoids in Washington, DC, May 31 and June 1, 2005. Because a thorough knowledge and understanding about

  8. Early Restoration Public Meeting, Washington, DC | NOAA Gulf Spill

    Science.gov (United States)

    benefit injured marshes, coastal dune and nearshore habitats, oysters, and human uses (on water recreation . Department of Commerce Herbert Hoover Building Auditorium 1401 Constitution Ave., NW Washington, D.C. 20230

  9. Drilling history core hole DC-6 Hanford, Washington

    International Nuclear Information System (INIS)

    1978-06-01

    Core hole DC-6 was completed in May 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scisson, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-6. Core hole DC-6 is located within the boundary of the Hanford Site at the old Hanford town site. The Hanford Site coordinates for DC-6 are North 54,127.17 feet and West 17,721.00 feet. The surface elevation is approximately 402 feet above sea level. The purpose of core hole DC-6 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection and to provide a borehole for hydrologic testing. The total depth of core hole DC-6 was 4336 feet. Core recovery was 98.4% of the total footage cored

  10. Energy Savings Analysis of the Proposed Revision of the Washington D.C. Non-Residential Energy Code

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, Michael I.; Athalye, Rahul A.; Hart, Philip R.

    2017-12-01

    This report presents the results of an assessment of savings for the proposed Washington D.C. energy code relative to ASHRAE Standard 90.1-2010. It includes annual and life cycle savings for site energy, source energy, energy cost, and carbon dioxide emissions that would result from adoption and enforcement of the proposed code for newly constructed buildings in Washington D.C. over a five year period.

  11. Sidwell Friends Quaker School, Washington, DC, by KieranTimberlake Architects

    DEFF Research Database (Denmark)

    Vibæk, Kasper Sánchez; Stylsvig Madsen, Ulrik

    2012-01-01

    In 2006 the new Middle School Building on the campus of Sidwell Friends School in Washington DC was completed at a cost of $28 million. The project is a renovation and addition to a fifty-year-old educational facility transforming the building and the surrounding landscape into a green expression...

  12. Proceedings of the American Psychological Association, Incorporated, for the legislative year 2015: Minutes of the Annual Meeting of the Council of Representatives February 20-22, 2015, Washington, DC, and August 5 and August 7, 2015, Washington, DC, and minutes of the February, June, August, and December 2015 meetings of the Board of Directors.

    Science.gov (United States)

    Kelly, Jennifer F

    2016-01-01

    This article provides the minutes of the Annual Meeting of the Council of Representatives February 20-22, 2015, Washington, DC, and August 5 and August 7, 2015, Washington, DC, and minutes of the February, June, August, and December 2015 meetings of the Board of Directors. These minutes are the official record of the actions of the Association taken during the year by both the Board of Directors (the Board) and the Council of Representatives (Council). They are arranged in topical rather than chronological order, and subheadings are used when appropriate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. Partners In Motion And Customer Satisfaction In The Washington Dc Metropolitan Area

    Science.gov (United States)

    1999-06-01

    PARTNERS IN MOTION IS A PROGRAM AIMED AT IMPROVING THE QUALITY, QUANTITY, AND AVAILABILITY OF TRAVEL INFORMATION TO TRANSPORTATION AGENCIES, THE MEDIA, AND, ULTIMATELY, TO THE TRAVELER IN THE WASHINGTON, D.C. METROPOLITAN AREA. THE PROGRAM WAS INITIA...

  14. 78 FR 37104 - Establishment of Area Navigation (RNAV) Routes; Washington, DC

    Science.gov (United States)

    2013-06-20

    ...-0081; Airspace Docket No. 12-AEA-5] RIN 2120-AA66 Establishment of Area Navigation (RNAV) Routes... Register approves this incorporation by reference action under 1 CFR part 51, subject to the annual... establishing five RNAV routes in the Washington, DC area (78 FR 29615). Subsequent to publication, it was...

  15. Alcohol Outlets and Violent Crime in Washington D.C.

    Directory of Open Access Journals (Sweden)

    Pan, William K

    2010-08-01

    Full Text Available Objective: Alcohol is more likely than any other drug to be involved in substance-related violence. In 2000 violence-related and self-directed injuries accounted for an estimated $37 billion and $33 billion in productivity losses and medical treatment, respectively. A review of emergency department data revealed violence and clinically identified trauma-related injuries have the strongest correlation among alcohol-dependent injuries. At the environmental level there is a relationship between alcohol outlet density and violent crime. A limited number of studies have examined the relationship between alcohol outlet type and the components of violent crime. The aim of this study is to examine the relationship between the aggregate components of violent crime and alcohol outlet density by type of outlet.Methods: For this study we used Washington, D.C. census tract data from the 2000 census to examine neighborhood characteristics. Alcohol outlet, violent crime, and population-level data for Washington, D.C. were drawn from various official yet publicly available sources. We developed an analytic database to examine the relationship between alcohol outlet category and four types of violent crime. After estimating spatial correlation and determining spatial dependence, we used a negative binomial regression analysis to assess the alcohol availability-violent crime association, while controlling for structural correlates of violence.Results: Independent of alternative structural correlates of violent crime, including the prevalence of weapons and illicit drugs, community-level alcohol outlet density is significantly associated with assaultive violence. Outlets were significantly related to robbery, assault, and sexual offenses. In addition, the relationship among on-premise and off-premise outlets varied across violent crime categories.Conclusion: In Washington, D.C., alcohol outlet density is significantly associated with the violent crimes. The

  16. A green roof grant program for Washington DC

    International Nuclear Information System (INIS)

    Johnson, P.A.

    2007-01-01

    The Chesapeake Bay Foundation (CBF) began its green roof demonstration project with $300,000 in funding provided by the DC Water and Sewer Authority. This paper reviewed the history of the project, its goals and early findings. The main objective was to demonstrate the technical, policy and economic feasibility of installing green roofs on commercial buildings in Washington DC and to promote green roofs as a means to manage storm water and improve water quality through the reduction of excessive runoff. The CBF has issued grants for the installation of 7 green roofs varying in size, design, location, and use. The projects included both new and existing structures designed to improve storm-water management in an urban area with significant pollution stress on the adjacent rivers. This paper provided technical, cost, and performance evaluations of each roof. A public outreach segment provided information to decision-makers to encourage more widespread replication of green roof technology throughout the metropolitan area. Much of the District of Columbia is served by a combined sewer system that becomes overloaded and discharges raw sewage into adjacent rivers during even moderately heavy rains. An average of 75 overflow events each year result in 1.5 billion gallons discharged into the Anacostia River. The installation of green roofs on buildings in the combined sewer area would retain storm water during these heavy rains and reduce the amount of overflow discharges. Apartments, as well as commercial and government buildings with mostly flat roofs are the most likely candidates for green roofs. The demonstration roofs are intended to become models, which all building owners could use as a guide for future plans for construction or re-construction to expand green roof coverage in Washington DC. It was emphasized that although such large-scale replication will take time and financial investments, it is achievable given enough political will and commercial awareness of

  17. DC Rocks! Using Place-Based Learning to Introduce Washington DC's K-12 Students to the Geosciences

    Science.gov (United States)

    Mayberry, G. C.; Mattietti, G. K.

    2017-12-01

    The Washington DC area has interesting geology and a multitude of agencies that deal with the geosciences, yet K-12 public school students in DC, most of whom are minorities, have limited exposure to the geosciences. Geoscience agencies in the DC area have a unique opportunity to address this by introducing the geosciences to local students who otherwise may not have such an opportunity, by highlighting the geology in the students' "backyard," and by leveraging partnerships among DC-based geoscience-related agencies. The USGS and George Mason University are developing a project called DC Rocks, which will give DC's students an exciting introduction into the world of geoscience with place-based learning opportunities that will make geoscience relevant to their lives and their futures. Both the need in DC and the potential for lasting impact are great; the geosciences have the lowest racial diversity of all the science, technology, engineering, and math (STEM) fields, 89% of students in DC public schools are minorities, and there is no dedicated geoscience curriculum in DC. DC Rocks aims to give these students early exposure to the earth sciences, and encourage them to consider careers in the profession. DC Rocks will work with partner agencies to apply several methods that are recommended by researchers to increase the participation of minority students in the geosciences, including providing profoundly positive experiences that spark interest in the geosciences (Levine et al., 2007); increasing students' sense of belonging in the geosciences (Huntoon, et al, 2016); and place-based teaching practices that emphasize the study of local sites (Semken, 2005), such as DC's Rock Creek Park. DC Rocks will apply these methods by coordinating local geoscientists and resources to provide real-world examples of the geosciences' impact on students' lives. Through the DC Rocks website, educators will be able to request geoscience-related resources such as class presentations by

  18. National Nuclear Waste Policy Act of 1981. Hearings before the Committee on Environment and Public Works, United States Senate, Ninety-Seventh Congress, First Session on S. 1662, October 31, 1981, Richland, Washington; November 9, 1981, Washington, DC

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Hearings were held on October 31, 1981 in Richland, Washington and on November 9, 1981 in Washington, DC to discuss the effort in S. 1662 to establish a national policy and an environmentally acceptable program for managing nuclear wastes from domestic commercial activities. The Richland hearing was held in recognition that Washington State will bear the major impact of the legislation. Witnesses at the Washington, DC hearing included officials from states that are potential sites for radioactive waste storage and disposal facilities. The hearing record includes the testimony of 16 witnesses in Richland and seven in Washington, DC, followed by a reprint of S. 1662 and additional material submitted for the record

  19. Drug Treatment in New York City and Washington, D.C.: Followup Studies.

    Science.gov (United States)

    Burt Associates, Inc., Bethesda, MD.

    This report assesses the experiences of clients who had contact with or received drug abuse treatment from programs of the Addiction Services Agency in New York City and the Narcotics Treatment Administration in Washington, D.C. during the early 1970's. To answer the questions of what happens to former clients once they leave drug treatment…

  20. Recent developments: Washington focus

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    November was a quiet month in Washington. Although Congress has recessed until 1991, the Senate filled vacancies in party leadership positions created by November's elections. The House is expected to proceed with its changes in early December. The Nuclear Energy Forum was held in Washington, DC on November 11-14 to discuss the status of the nuclear industry in the USA. The Forum, held in conjunction with the American Nuclear Society's annual meeting, assembled a large number of CEO's from US, European, and Far Eastern utilities and vendors. The meeting concluded with an announcement by Philip Bayne, President of NYPA and chairman of the Nuclear Power Oversight Committee (NPOC), of the results of a year-long NPOC study entitled a open-quotes Strategic Plan for Building New Nuclear Power Plants.close quotes

  1. The hydrogeology of urbanization: The lost springs of Washington, D.C., late Tertiary and Quaternary sediments of D.C., and the Baltimore Long Term Ecological Research site (LTER): Chapter

    Science.gov (United States)

    Bhaskar, Aditi; Pavich, Milan J.; Sharp, John M.

    2015-01-01

    Urbanization is a major process now shaping the environment. This field trip looks at the hydrogeology of the general Washington, D.C., area and focuses on the city's lost springs. Until 150 years ago, springs and shallow dug wells were the main source of drinking water for residents of Washington, D.C. Celebrating the nation's bicentennial, Garnett P. Williams of the U.S. Geological Survey examined changes in water supply and water courses since 1776. He examined old newspaper files to determine the location of the city's springs. This field trip visits sites of some of these springs (few of which are now flowing), discusses the hydrologic impacts of urbanization and the general geological setting, and finishes with the Baltimore Long Term Ecological Research site at Dead Run and its findings. The field trip visits some familiar locations in the Washington, D.C., area, and gives insights into their often hidden hydrologic past and present.

  2. Residential Energy Efficiency Research Planning Meeting Summary Report: Washington, D.C. - October 27-28, 2011

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-01

    This report summarizes key findings and outcomes from the U.S. Department of Energy's Building America Residential Energy Efficiency Research Planning meeting, held on October 28-29, 2011, in Washington, D.C.

  3. Proceedings of public hearings: plutonium and the other transuranium elements, Washington, D.C., December 10--11, 1974. Volume 1

    International Nuclear Information System (INIS)

    1974-01-01

    The Environmental Protection Agency embarked on a program to evaluate the environmental impact of the transuranium elements and to consider whether further guidelines or standards are needed to assure adequate protection of the general ambient environment and of the public health from potential contamination of the environment by radionuclides of these elements. Public hearings were held in Washington, D. C., and Denver, Colorado, to gather information regarding the public and social implications of plutonium utilization; the factors involved in the balancing of costs vs benefits; dosimetry, health, and environmental effects; environmental levels and pathways; applications using plutonium; and control and cleanup technology. The proceedings of the hearing in Washington, D. C., Dec. 10-11, 1974, are presented. Data are included on current and potential sources of transuranium elements in the environment; animal studies on the tissue distribution of 233 U, 237 Np, 238 Pu, 239 Pu, 241 Am, 244 Cm, 249 Bk, 252 Cf, and 253 Es and pathological effects of body burdens of these radionuclides; and data on the health status of personnel known to have body burdens of 238 Pu or 239 Pu acquired during acute or chronic exposure, many of them over 30 years previously. It is pointed out that the lack of demonstrable biological effects of Pu in man provides presumptive evidence that the radiation protection standards in effect are adequate. (U.S.)

  4. Can learning in informal settings mitigate disadvantage and promote urban sustainability? School gardens in Washington, DC

    Science.gov (United States)

    Fisher-Maltese, Carley; Fisher, Dana R.; Ray, Rashawn

    2017-09-01

    This article explores how school gardens provide learning opportunities for school-aged children while concurrently helping cities achieve sustainability. The authors analyse this process in Washington, DC, a particularly innovative metropolis in the United States. This national capital city boasts two of the most progressive examples of legislation aimed at improving environmental awareness and inciting citizens to engage in environmental stewardship, both of which focus on school-aged children: (1) the Healthy Schools Act of 2010 and (2) the Sustainable DC Act of 2012. Together these policies focus on bringing healthy lifestyles and environmental awareness, including meaningful outdoor learning experiences, to students and families in the District of Columbia. This article is organised into three parts. The first part discusses how Washington, DC became a sustainable learning city through the implementation of these specific policies. The next part presents the results of a pilot study conducted in one kindergarten to Grade 5 (K-5) elementary school located in Ward 8, the poorest part of the city. The authors' analysis considers the support and the obstacles teachers and principals in the District of Columbia (DC) are experiencing in their efforts to integrate school gardens into the curriculum and the culture of their schools. Exploring the impacts of the school garden on the students, the local community, and the inter-generational relationships at and beyond schools, the authors aim to shed light on the benefits and the challenges. While Washington, DC is fostering its hope that the benefits prevail as it provides a model for other cities to follow, the authors also candidly present the challenges of implementing these policies. In the final part, they discuss the implications of their findings for school gardens and sustainable learning cities more broadly. They encourage further research to gain more insights into effective ways of promoting environmental

  5. Effects of the 2002 sniper attacks on the homeless population in Washington, DC.

    Science.gov (United States)

    Fullerton, Carol S; Gifford, Robert K; Flynn, Brian W; Peterson, Karen M; Ahearn, Frederick L; Donaldson, Linda Plitt; Ursano, Robert J

    2009-10-01

    Despite the prevalence of homelessness, this population has rarely been included in disaster and terrorism planning. To better understand the mental health needs of the homeless during a terrorist event and to highlight the need to address methodological limitations in research in this area, we examined responses to the October 2002 Washington, DC, sniper attacks. We interviewed 151 homeless individuals 1 year after the Washington, DC, sniper attacks. The majority (92.7%) was aware of the sniper events; 84.1% stayed informed through the media and 72.7% had someone to turn to for emotional support. Almost half (44%) reported identification with victims and 41% increased substance use during the attacks. More than half (61.7%) felt extremely frightened or terrified and 57.6% reported high perceived threat. Females, nonwhites, and participants with less than a high school education experienced greater threat. Women, nonwhites, and younger (homeless population may be difficult to reach or reluctant to comply with public health programs. Addressing barriers to health care in vulnerable groups is critical to effective public health disaster response.

  6. Brief research report: sociodemographic factors associated with HIV status among African American women in Washington, DC

    Directory of Open Access Journals (Sweden)

    Perkins EL

    2013-09-01

    Full Text Available Emory L Perkins,1 Dexter R Voisin,2 Kesslyn A Brade Stennis1 1Department of Social Work, Bowie State University, Bowie, MD, USA; 2School of Social Service Administration, University of Chicago, Chicago, IL, USA Introduction: African American women living in Washington, DC have one of the highest Human immunodeficiency virus (HIV incidence rates in the US. However, this population has been understudied, especially as it relates to factors associated with HIV status. Methods: This cross-sectional study examined sociodemographic factors that were associated with having a negative or positive HIV status among a sample of 115 African American women between the ages of 24 and 44 years. We assessed such factors as age, education, sexual orientation, household income, sources of income, number of children, length of residency tenure in Washington, DC, and level of HIV-prevention knowledge. Results: Among the overall sample, 53 women self-identified as HIV-positive and 62 as HIV-negative. Compared to their HIV-negative counterparts, women who reported being HIV-positive were less educated, had lower household income, and had longer residency tenure in Washington, DC. There were no differences in HIV knowledge between HIV-positive and -negative study participants. Conclusion: These findings may provide important directions for targeting specific subpopulations of African Americans for HIV-prevention/intervention programs. Keywords: HIV status, African American women, sociodemographic factors

  7. Report of the Annual Scientific Sessions of the American College of Cardiology (ACC), Washington DC.

    Science.gov (United States)

    Hiro, Takafumi

    2017-05-25

    The 66 th Annual Scientific Sessions and Expo of the American College of Cardiology (ACC) were held at the Walter E. Washington Convention Center, Washington DC, from March 17 th to 19 th , 2017. This meeting offered 23 Late-Breaking Clinical Trial (LBCT) presentations, 17 Featured Clinical Research presentations with and without LBCT, and 2,572 abstracts presented in oral and poster sessions by over 2,000 experts. This report presents the highlights of this meeting, including the opening showcase, several important LBCTs and some international joint symposiums.

  8. Breakfast and Learning in Children. Symposium Proceedings (Washington, DC, April 22, 1999).

    Science.gov (United States)

    Food, Nutrition, and Consumer Services (USDA), Washington, DC. Center for Nutrition Policy and Promotion.

    Noting that many schools do not participate in the U.S. Department of Agriculture's School Breakfast Program despite evidence that poor nutrition affects children's school attendance and performance, this document presents the proceedings of a 1999 symposium on links between breakfast and school performance and the implications for public policy.…

  9. 75 FR 1406 - National Mall and Memorial Parks, Washington, DC; Notice of Availability of an Environmental...

    Science.gov (United States)

    2010-01-11

    ... Washington, DC. The National Mall Plan is a long-range management plan that focuses on the use and... Spain, Project Executive. Before including your address, phone number, e-mail address, or other personal... Impact Statement. FOR FURTHER INFORMATION CONTACT: Susan Spain, Project Executive, National Mall Plan at...

  10. Spacelab ready for transport to Washington, DC

    Science.gov (United States)

    1998-01-01

    Spacelab is wrapped and ready for transport to the National Air and Space Museum in Washington, DC. Spacelab was designed by the European Space Agency (ESA) for the Space Shuttle program and first flew on STS-9 in November 1983. Its final flight was the STS-90 Neurolab mission in April 1998. A sister module will travel home and be placed on display in Europe. The Spacelab concept of modular experiment racks in a pressurized shirt-sleeve environment made it highly user-friendly and accessible. Numerous experiments conceived by hundreds of scientists on the ground were conducted by flight crews in orbit. Spacelab modules served as on-orbit homes for everything from squirrel monkeys to plant seeds. They supported astronomical as well as Earth observations, for servicing the Hubble Space Telescope and for research preparatory to the International Space Station. One of the greatest benefits afforded by the Spacelab missions was the opportunity to fly a mission more than once, with the second or third flight building on the experiences and data gathered from its predecessors.

  11. Making Difficult History Public: The Pedagogy of Remembering and Forgetting in Two Washington DC Museums

    Science.gov (United States)

    Segall, Avner

    2014-01-01

    In this article, Avner Segall explores some pedagogical processes in the context of two museums in Washington, DC, that focus on difficult knowledge, the National Museum of the American Indian (NMAI) and the United States Holocaust Memorial Museum. In doing so, Segall's aim is not to explore the museums as a whole or provide a comprehensive…

  12. Cigarette price variation around high schools: evidence from Washington DC.

    Science.gov (United States)

    Cantrell, Jennifer; Ganz, Ollie; Anesetti-Rothermel, Andrew; Harrell, Paul; Kreslake, Jennifer M; Xiao, Haijun; Pearson, Jennifer L; Vallone, Donna; Kirchner, Thomas R

    2015-01-01

    This study examines lowest cigarette prices in all tobacco retail outlets in Washington D.C. (n=750) in relation to the type and number of high schools nearby, controlling for confounders. The lowest overall and Newport menthol prices were significantly lower at outlets near public non-charter and charter schools compared with outlets near private schools. Given higher smoking prevalence and more price-sensitive youth subgroups in U.S. public schools, exposure to low prices may contribute to tobacco-related health disparities in minority and low-income populations. Tobacco taxes combined with policies to minimize the increasing use of price as a marketing tool are critical. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. 2013 EFRC PI Meeting -- Science for Our Nation's Energy Future: Energy Frontier Research Centers Principal Investigators' Meeting, Washington, D.C., July 18-19, 2013

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-07-01

    2013 EFRC Principal Investigators’ Meeting, July 18-19, 2013 in Washington D.C. By invitation only--about 500 attendees from the EFRCs and DOE, 235 senior EFRC members and 165 EFRC early career scientists from more than 80 institutions in 31 states, 2 foreign countries and Washington D.C. Over 115 talks and 225 posters

  14. Enjoying green cities: Assessing visitors' attitude and preferences of urban forests in Washington, D.C.

    Science.gov (United States)

    Rogelio II Andrada; Jinyang. Deng

    2012-01-01

    This study examined the attitudes and preferences of visitors toWashington, D.C., one of the top tourism cities in the United States. Results of a visitor survey conducted at two sites show that respondents have a highly positive attitude towards the city's urban forest and that their appreciation of the urban forest has a positive influence on their experiences...

  15. Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications

    OpenAIRE

    Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.

    2017-01-01

    in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...

  16. Natural gas pipeline leaks across Washington, DC.

    Science.gov (United States)

    Jackson, Robert B; Down, Adrian; Phillips, Nathan G; Ackley, Robert C; Cook, Charles W; Plata, Desiree L; Zhao, Kaiguang

    2014-01-01

    Pipeline safety in the United States has increased in recent decades, but incidents involving natural gas pipelines still cause an average of 17 fatalities and $133 M in property damage annually. Natural gas leaks are also the largest anthropogenic source of the greenhouse gas methane (CH4) in the U.S. To reduce pipeline leakage and increase consumer safety, we deployed a Picarro G2301 Cavity Ring-Down Spectrometer in a car, mapping 5893 natural gas leaks (2.5 to 88.6 ppm CH4) across 1500 road miles of Washington, DC. The δ(13)C-isotopic signatures of the methane (-38.2‰ ± 3.9‰ s.d.) and ethane (-36.5 ± 1.1 s.d.) and the CH4:C2H6 ratios (25.5 ± 8.9 s.d.) closely matched the pipeline gas (-39.0‰ and -36.2‰ for methane and ethane; 19.0 for CH4/C2H6). Emissions from four street leaks ranged from 9200 to 38,200 L CH4 day(-1) each, comparable to natural gas used by 1.7 to 7.0 homes, respectively. At 19 tested locations, 12 potentially explosive (Grade 1) methane concentrations of 50,000 to 500,000 ppm were detected in manholes. Financial incentives and targeted programs among companies, public utility commissions, and scientists to reduce leaks and replace old cast-iron pipes will improve consumer safety and air quality, save money, and lower greenhouse gas emissions.

  17. Needs Assessment of the Healthcare Sector in the Washington, D.C., Metropolitan Area. Research Report. Business Needs Assessment Study.

    Science.gov (United States)

    Northern Virginia Community Coll., Annandale. Office of Institutional Research.

    According to the U.S. Bureau of Labor Statistics, the growing population of elderly citizens will result in an increased demand for healthcare services that will rise for a full 50 years. This study assesses the need for healthcare sector workers in the Washington, D.C. metropolitan area. Information on the skills, education, and experience that…

  18. 108th Convention of the American Psychological Association. Washington, DC, August 4-8, 2000

    Science.gov (United States)

    2000-04-01

    Washington, DC--the nation's capital--celebrates a history rich in diversity and character. One of the most popular cities for sightseeing, Washington contains countless points of interest for its visitors. The world's largest museum complex, the Smithsonian Institution, invites you to explore exhibits that highlight the scientific, cultural, political, and technological developments of the United States and its people. Visit the home to original pieces of the American heritage, such as the Declaration of Independence, the Constitution, and the Bill of Rights, that have helped to shape the way we live today. The art lovers among you will delight in the seven major art galleries. See the modern art and sculpture of the Hirshhorn Museum and the newly opened Sculpture Garden; the Sackler Gallery's collection of Asian art; and the only museum devoted to the art and culture of Africa, the National Museum of African Art. In Washington, there is music in the air, from the Kennedy Center's many stages and the clubs of Georgetown and Adams Morgan to the military bands that give concerts on the Mall. Whatever your culinary desire, be it authentic Texas chili or the finest Asian cuisine, you'll find it at one of the city's internationally famous eateries. What a perfect place for APA to convene its first annual convention of the new millennium!

  19. THE ROLE OF HISTORICAL AERIAL PHOTOGRAPHS IN THE REMEDIATION OF WWI CHEMICAL CONTAMINATION IN THE SPRING VALLEY SUPERFUND SITE, WASHINGTON, DC

    Science.gov (United States)

    During World War 1, The American University in Washington D.C. was used by the U.S. Army as an experiment station for the development and testing of a variety of battlefield munitions including chemical weapons such as Mustard Gas, Phosgene, Ricin and Lewisite, among others. Afte...

  20. An Analysis of Wintertime Winds in Washington, D.C.

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Larry K.; Allwine, K Jerry

    2006-06-20

    This report consists of a description of the wintertime climatology of wind speed and wind direction around the National Mall in Washington, D.C. Meteorological data for this study were collected at Ronald Reagan Washington National Airport (Reagan National), Dulles International Airport (Dulles), and a set of surface meteorological stations that are located on a number of building tops around the National Mall. A five-year wintertime climatology of wind speed and wind direction measured at Reagan National and Dulles are presented. A more detailed analysis was completed for the period December 2003 through February 2004 using data gathered from stations located around the National Mall, Reagan National, and Dulles. Key findings of our study include the following: * There are systematic differences between the wind speed and wind direction observed at Reagan National and the wind speed and wind direction measured by building top weather stations located in the National Mall. Although Dulles is located much further from the National Mall than Reagan National, there is better agreement between the wind speed and wind direction measured at Dulles and the weather stations in the National Mall. * When the winds are light (less than 3 ms-1 or 7 mph), there are significant differences in the wind directions reported at the various weather stations within the Mall. * Although the mean characteristics of the wind are similar at the various locations, significant, short-term differences are found when the time series are compared. These differences have important implications for the dispersion of airborne contaminants. In support of wintertime special events in the area of the National Mall, we recommend placing four additional meteorological instruments: three additional surface stations, one on the east bank of the Potomac River, one south of the Reflecting Pool (to better define the flow within the Mall), and a surface station near the Herbert C. Hoover Building; and wind

  1. Patterns of HIV/AIDS, STI, Substance Abuse and Hepatitis Risk among Selected Samples of Latino and African-American Youth in Washington, DC

    Science.gov (United States)

    Edberg, Mark C.; Collins, Elizabeth; Harris, Meredith; McLendon, Hedda; Santucci, Patricia

    2009-01-01

    In order to address evolving risk factors among youth in Washington, DC (District of Columbia), with respect to HIV/AIDS, sexually transmitted infections (STIs), substance abuse, and hepatitis, a targeted, community-needs assessment was conducted through a partnership between the Department of Prevention and Community Health at George Washington…

  2. Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C.

    Science.gov (United States)

    Lyttle, Peter T.; Aleinikoff, John N.; Burton, William C.; Crider, E. Allen; Drake, Avery A.; Froelich, Albert J.; Horton, J. Wright; Kasselas, Gregorios; Mixon, Robert B.; McCartan, Lucy; Nelson, Arthur E.; Newell, Wayne L.; Pavlides, Louis; Powars, David S.; Southworth, C. Scott; Weems, Robert E.

    2018-01-02

    The Washington West 30’ × 60’ quadrangle covers an area of approximately 4,884 square kilometers (1,343 square miles) in and west of the Washington, D.C., metropolitan area. The eastern part of the area is highly urbanized, and more rural areas to the west are rapidly being developed. The area lies entirely within the Chesapeake Bay drainage basin and mostly within the Potomac River watershed. It contains part of the Nation's main north-south transportation corridor east of the Blue Ridge Mountains, consisting of Interstate Highway 95, U.S. Highway 1, and railroads, as well as parts of the Capital Beltway and Interstate Highway 66. Extensive Federal land holdings in addition to those in Washington, D.C., include the Marine Corps Development and Education Command at Quantico, Fort Belvoir, Vint Hill Farms Station, the Naval Ordnance Station at Indian Head, the Chesapeake and Ohio Canal National Historic Park, Great Falls Park, and Manassas National Battlefield Park. The quadrangle contains most of Washington, D.C.; part or all of Arlington, Culpeper, Fairfax, Fauquier, Loudoun, Prince William, Rappahannock, and Stafford Counties in northern Virginia; and parts of Charles, Montgomery, and Prince Georges Counties in Maryland.The Washington West quadrangle spans four geologic provinces. From west to east these provinces are the Blue Ridge province, the early Mesozoic Culpeper basin, the Piedmont province, and the Coastal Plain province. There is some overlap in ages of rocks in the Blue Ridge and Piedmont provinces. The Blue Ridge province, which occupies the western part of the quadrangle, contains metamorphic and igneous rocks of Mesoproterozoic to Early Cambrian age. Mesoproterozoic (Grenville-age) rocks are mostly granitic gneisses, although older metaigneous rocks are found as xenoliths. Small areas of Neoproterozoic metasedimentary rocks nonconformably overlie Mesoproterozoic rocks. Neoproterozoic granitic rocks of the Robertson River Igneous Suite intruded

  3. Texts of joint USA-USSR statements following the summit meeting in Washington, D.C., 31 May - 3 June 1990

    International Nuclear Information System (INIS)

    1990-07-01

    The texts of joint USA-USSR statements following the summit meeting in Washington, D.C., 31 May - 3 June 1990 are reproduced. One is a joint statement on non-proliferation of nuclear weapons, missile and missile technology and chemical weapons, another one is a joint statement on the International Thermonuclear Experimental Reactor and the last one is a joint statement on Cooperation in Peaceful Uses of Atomic Energy

  4. U.S. Department of Energy Hydrogen and Fuel Cells Program 2014 Annual Merit Review and Peer Evaluation Report: June 16-20, 2014, Washington, D.C.

    Energy Technology Data Exchange (ETDEWEB)

    2014-10-01

    The fiscal year (FY) 2014 U.S. Department of Energy (DOE) Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting (AMR), in conjunction with DOE's Vehicle Technologies Office AMR, was held from June 16-20, 2014, at the Washington Marriott Wardman Park in Washington, D.C. This report is a summary of comments by AMR peer reviewers about the hydrogen and fuel cell projects funded by DOE's Office of Energy Efficiency and Renewable Energy (EERE).

  5. VSP - Discussion: The Common Interest on Planning Hulls and Plan for Collaboration Studies between NSWC and KRISO - Washington DC

    Science.gov (United States)

    2016-03-07

    planning hulls and plan for N62909-15-1-2052 collaboration studies between NSWC and KRISO - Washington DC Sb. GRANT NUMBER N62909-15-1-2052 Sc. PROGRAM...be carried out in MASK’s facilities. We discussed common interests on planing hulls, and made plans for collaboration studies between NSWC and KRISO ...Presentation of USV project in KRISO 8/19/2015 (Wed) • Discussion of common interests about planing hu lls • Planning for collaboration studies

  6. Survey about pedestrian safety and attitudes toward automated traffic enforcement in Washington, D.C.

    Science.gov (United States)

    Cicchino, Jessica B; Wells, Joann K; McCartt, Anne T

    2014-01-01

    Pedestrians represent more than one third of all traffic deaths in Washington, D.C. The District plans to expand its long-standing automated traffic enforcement program in 2013 from speed and red light cameras to cameras to enforce pedestrian right-of-way laws at crosswalks and stop sign laws. This study collected information on the opinions, behaviors, and knowledge of D.C. residents related to camera enforcement and pedestrian safety issues. A telephone survey of 801 adult D.C. residents was conducted in November 2012 with approximately equal numbers of respondents in each of D.C.'s eight wards. Quotas were used to ensure that the sample was representative of the demographic characteristics of adults in each ward. For analyses combining responses across the wards, data were weighted to correspond with the demographic characteristics of adults in the city. Most respondents believed that drivers speeding, running red lights, running stop signs, and not stopping for pedestrians are serious threats to their safety. Respondents strongly supported the speed and red light camera programs, with 76 percent of respondents favoring speed cameras and 87 percent favoring red light cameras. Support was more limited for the camera enforcement that was not yet in place at the time of the survey, with 50 percent of respondents favoring stop sign cameras and 47 percent of respondents favoring crosswalk cameras. Twenty-four percent of respondents had not driven a car in D.C. in the past month, and higher proportions of these nondrivers favored speed cameras (90%), stop sign cameras (67%), and crosswalk cameras (59%) than respondents who drove in D.C. in the past month. Respondents who supported camera enforcement cited safety as their main reason. More than 9 in 10 respondents knew that D.C. law requires drivers to stop for pedestrians crossing the street in marked crosswalks at intersections without traffic signals and midblock, but only 54 percent knew that drivers must stop for

  7. An assessment of solar hot water heating in the Washington, D.C. area - Implications for local utilities

    Science.gov (United States)

    Stuart, M. W.

    1980-04-01

    A survey of residential solar hot water heating in the Washington, D.C. area is presented with estimates of the total solar energy contribution per year. These estimates are examined in relation to a local utility's peak-load curves to determine the impact of a substantial increase in solar domestic hot water use over the next 20 yr in the area of utility management. The results indicate that a 10% market penetration of solar water heaters would have no detrimental effect on the utility's peak-load profile and could save several million dollars in new plant construction costs.

  8. 75 FR 68686 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-14, DC-9-15, and DC-9-15F...

    Science.gov (United States)

    2010-11-09

    ... Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer... requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Wahib Mina, Aerospace...

  9. Modeling the effect of transient populations on epidemics in Washington DC.

    Science.gov (United States)

    Parikh, Nidhi; Youssef, Mina; Swarup, Samarth; Eubank, Stephen

    2013-11-06

    Large numbers of transients visit big cities, where they come into contact with many people at crowded areas. However, epidemiological studies have not paid much attention to the role of this subpopulation in disease spread. We evaluate the effect of transients on epidemics by extending a synthetic population model for the Washington DC metro area to include leisure and business travelers. A synthetic population is obtained by combining multiple data sources to build a detailed minute-by-minute simulation of population interaction resulting in a contact network. We simulate an influenza-like illness over the contact network to evaluate the effects of transients on the number of infected residents. We find that there are significantly more infections when transients are considered. Since much population mixing happens at major tourism locations, we evaluate two targeted interventions: closing museums and promoting healthy behavior (such as the use of hand sanitizers, covering coughs, etc.) at museums. Surprisingly, closing museums has no beneficial effect. However, promoting healthy behavior at the museums can both reduce and delay the epidemic peak. We analytically derive the reproductive number and perform stability analysis using an ODE-based model.

  10. Modeling the effect of transient populations on epidemics in Washington DC

    Science.gov (United States)

    Parikh, Nidhi; Youssef, Mina; Swarup, Samarth; Eubank, Stephen

    2013-11-01

    Large numbers of transients visit big cities, where they come into contact with many people at crowded areas. However, epidemiological studies have not paid much attention to the role of this subpopulation in disease spread. We evaluate the effect of transients on epidemics by extending a synthetic population model for the Washington DC metro area to include leisure and business travelers. A synthetic population is obtained by combining multiple data sources to build a detailed minute-by-minute simulation of population interaction resulting in a contact network. We simulate an influenza-like illness over the contact network to evaluate the effects of transients on the number of infected residents. We find that there are significantly more infections when transients are considered. Since much population mixing happens at major tourism locations, we evaluate two targeted interventions: closing museums and promoting healthy behavior (such as the use of hand sanitizers, covering coughs, etc.) at museums. Surprisingly, closing museums has no beneficial effect. However, promoting healthy behavior at the museums can both reduce and delay the epidemic peak. We analytically derive the reproductive number and perform stability analysis using an ODE-based model.

  11. Childhood sexual abuse and HIV-related risks among men who have sex with men in Washington, DC.

    Science.gov (United States)

    Phillips, Gregory; Magnus, Manya; Kuo, Irene; Rawls, Anthony; Peterson, James; Montanez, Luz; West-Ojo, Tiffany; Jia, Yujiang; Opoku, Jenevieve; Greenberg, Alan E

    2014-05-01

    Childhood sexual abuse (CSA) has been reported to be disproportionately higher among men who have sex with men (MSM) than among heterosexual men; it has also been found to be significantly positively associated with HIV status and HIV risk factors, including unprotected anal intercourse. The purpose of this study was to assess the correlates of CSA in a sample of community-recruited MSM, investigate race as a potential effect modifier, and describe the independent association between CSA and HIV infection in Washington, DC. A total of 500 MSM were recruited by venue-based sampling in 2008 as part of the National HIV Behavioral Surveillance. More than one-half of MSM identified as White, while one-third identified as Black. CSA was reported by 17.5 % of the 451 MSM, with the first instance of abuse occurring at a median age of 8.3 (interquartile range = 5.0, 11.0). In multivariable analysis, HIV-positive men were significantly more likely to report a history of CSA compared to HIV-negative men after adjusting for intimate partner violence in the last 12 months, having been arrested in the last 12 months, and depressive symptoms. HIV-positive MSM had more than four times the odds of reporting CSA after controlling for other correlates (aOR = 4.19; 95 % CI 2.26, 7.75). Despite hypothesizing that race modified the effect of CSA on HIV infection we found this was not the case in this sample. More research is needed to investigate the potential pathway between a history of CSA and HIV infection, and how this contributes to driving the HIV epidemic among MSM in Washington, DC.

  12. Map Sensitivity vs. Map Dependency: A Case Study of Subway Maps’ Impact on Passenger Route Choices in Washington DC

    Directory of Open Access Journals (Sweden)

    John Xu

    2017-10-01

    Full Text Available This paper addresses the key assumption in behavioral and transportation planning literature that, when people use a transit system more frequently, they become less dependent on and less sensitive to transit maps in their decision-making. Therefore, according to this assumption, map changes are much less impactful to travel decisions of frequent riders than to that of first-time or new passengers. This assumption—though never empirically validated—has been the major hurdle for transit maps to becoming a planning tool to change passengers’ behavior. This paper examines this assumption using the Washington DC metro map as a case study by conducting a route choice experiment between 30 Origin-Destination (O-D pairs on seven metro map designs. The experiment targets two types of passengers: frequent metro riders through advertisements on a free daily newspaper available at DC metro stations, and general residents in the Washington metropolitan area through Amazon Mechanical Turk, an online crowdsourcing platform. A total of 255 and 371 participants made 2024 and 2960 route choices in the respective experiments. The results show that frequent passengers are in fact more sensitive to subtle changes in map design than general residents who are less likely to be familiar with the metro map and therefore unaffected by map changes presented in the alternative designs. The work disproves the aforementioned assumption and further validates metro maps as an effective planning tool in transit systems.

  13. Psychological resilience: the impact of affectivity and coping on state anxiety and positive emotions during and after the Washington, DC sniper killings.

    Science.gov (United States)

    Moore, Philip J; Chrabaszcz, Jeffrey S; Peterson, Rolf A; Rohrbeck, Cynthia A; Roemer, Enid C; Mercurio, Andrea E

    2014-01-01

    This research examined the impact of affectivity and coping on state anxiety and positive emotions among young adults living in the Washington, DC metro area both during and after the Washington, DC sniper killings. Participants completed questionnaires during three waves of data collection: (1) during the sniper attacks (n=92); (2) within two weeks after the snipers were captured (n=45); and (3) six months later (n=43). Affectivity (measured by neuroticism) was significantly associated with state anxiety and positive emotions during all three time periods. Coping (measured by constructive thinking) predicted state anxiety and positive emotions during the shootings, but was unrelated to either outcome immediately after the attacks, and marginally related to them six months later. Consistent with the Dynamic Model of Affect, state anxiety and positive emotions were more strongly (and negatively) correlated with each other during the killings than they were after the snipers were apprehended. Taken together, these results support transactional models of stress that emphasize the interaction between dispositional and situational influences, and they suggest that affectivity reflects a fundamental set of reactions to one's environment, while coping dispositions result in more stress-specific responses. Additional theoretical and practical implications of these findings are also discussed.

  14. Distress of Routine Activities and Perceived Safety Associated with Post-Traumatic Stress, Depression, and Alcohol Use: 2002 Washington, DC, Sniper Attacks.

    Science.gov (United States)

    Fullerton, Carol S; Herberman Mash, Holly B; Benevides, K Nikki; Morganstein, Joshua C; Ursano, Robert J

    2015-10-01

    For over 3 weeks in October 2002, a series of sniper attacks in the Washington, DC, area left 10 people dead and 3 wounded. This study examined the relationship of distress associated with routine activities and perceived safety to psychological and behavioral responses. Participants were 1238 residents of the Washington, DC, metropolitan area (aged 18 to 90 years, mean=41.7 years) who completed an Internet survey including the Impact of Event Scale-Revised, Patient Health Questionnaire-9, and items pertaining to distress related to routine activities, perceived safety, and alcohol use. Data were collected at one time point approximately 3 weeks after the first sniper shooting and before apprehension of the suspects. Relationships of distress and perceived safety to post-traumatic stress, depressive symptoms, and increased alcohol use were examined by using linear and logistic regression analyses. Approximately 8% of the participants met the symptom criteria for probable post-traumatic stress disorder, 22% reported mild to severe depression, and 4% reported increased alcohol use during the attacks. Distress related to routine activities and perceived safety were associated with increased post-traumatic stress and depressive symptoms and alcohol use. Distress and perceived safety are associated with specific routine activities and both contribute to psychological and behavioral responses during a terrorist attack. These findings have implications for targeted information dissemination and risk communication by community leaders.

  15. Drilling history core hole DC-4

    International Nuclear Information System (INIS)

    1978-12-01

    Core hole DC-4 was completed at a depth of 3998 feet in December, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Sicsson, Inc. furnished the engineering, daily supervision of the cable tool and core drilling activities, and geological core logging for DC-4. Core hole DC-4 is located on the Hanford Site about 3 miles east of the Yakima Barricade and approximately 103 feet southwest of rotary hole DC-5, which was completed to 3990 feet in February, 1978. Hanford Site coordinates reported for hole DC-4 are north 49,385.62 feet and west 85,207.63 feet, and Washington State coordinates are north 454,468.73 feet and east 2,209,990.87 feet. No elevation survey is available for hole DC-4, but it is approximately 745 feet above mean sea level based upon the survey of hole DC-5, which has a reported elevation of 745.16 feet on the top of the 3-inch flange. The purpose of core hole DC-4 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing, cross-hole seismic shear, and pressure wave velocity studies with rotary hole DC-5. Hole DC-4 was drilled through the overburden into basalt bedrock by cable tool methods (0-623 feet) and continuously cored through the final interval (623 to 3998 feet).Core recovery was 95.8 percent of the total footage cored

  16. Large Dog Relinquishment to Two Municipal Facilities in New York City and Washington, D.C.: Identifying Targets for Intervention

    Science.gov (United States)

    Weiss, Emily; Slater, Margaret; Garrison, Laurie; Drain, Natasha; Dolan, Emily; Scarlett, Janet M.; Zawistowski, Stephen L.

    2014-01-01

    Simple Summary While the overall trend in euthanasia has been decreasing nationally, large dogs are at a higher risk of euthanasia than other-sized dogs in most animal shelters in the United States. We hypothesized that one way to increase the lives saved with regard to large dogs in shelters is to keep them home in the first place when possible. Our research is the first to collect data in New York City and Washington, D.C., identifying the process leading to the owner relinquishment of large dogs. We found that targets for interventions to decrease large dog relinquishment are likely different in each community. Abstract While the overall trend in euthanasia has been decreasing nationally, large dogs are at a higher risk of euthanasia than other sized dogs in most animal shelters in the United States. We hypothesized one way to increase the lives saved with respect to these large dogs is to keep them home when possible. In order to develop solutions to decrease relinquishment, a survey was developed to learn more about the reasons owners relinquish large dogs. The survey was administered to owners relinquishing their dogs at two large municipal facilities, one in New York City and one in Washington, D.C. There were 157 responses between the two facilities. We found both significant similarities and differences between respondents and their dogs from the two cities. We identified opportunities to potentially support future relinquishers and found that targets for interventions are likely different in each community. PMID:26480315

  17. Quantifying the Consumptive Landscape in the Potomac Watershed Upstream From Washington DC

    Science.gov (United States)

    Kearns, M.; Zegre, N.; Fernandez, R.

    2017-12-01

    Some of the largest and fastest-growing eastern cities depend upon Appalachian headwaters for their fresh water. Today's relative abundance of water may be at risk: changes in climate and land use could alter the availability of surface water and human consumption could increase to meet the needs of a growing population and economy. Neither the supply of surface water nor the various withdrawals that support our population, irrigation, energy, and industry are distributed uniformly throughout our watersheds. This study correlates surface water withdrawals, consumptive use coefficients, and land-use/land-cover datasets to create a model for quantifying anthropogenic water consumption. The model suggests a method for downscaling and redistributing USGS county-level surface water withdrawals to 30 meter cells. Initially completed for the Potomac River watershed upstream from Washington DC's public supply intake, this approach could easily scale regionally or nationally. When combined with runoff estimates over the same landscape, the net-production or net-consumption of an area of interest may be calculated at high resolution. By better understanding the spatial relationship between hydrologic supply and demand, we can seek to improve the efficiency and security of our water resources.

  18. The Society for Pediatric Radiology, 38th annual meeting, Washington, DC, USA, April 27-30, 1995. Gold medalists, honorary members, pioneer session, abstracts

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The contribution reports the highlights of the 38th annual meeting of the Society for Pediatric Radiology in Washington, DC, from 27 - 30 April, 1995. The abstracts of the 96 papers presented at the sessions on all pediatric subject fields are reproduced, and the gold medalists of the Society of the year 1995 are introduced with a brief c.v. and a survey of their careers. (VHE) [de

  19. A Study of Gaps in Attack Analysis

    Science.gov (United States)

    2016-10-12

    Communications Security, CCS 2003, Washington, DC, USA, October 27-30, 2003, pages 281–289, 2003. [9] Adam Barth, Collin Jackson, and John C. Mitchell. Robust...Proceedings of the 2014 IEEE Symposium on Security and Privacy, SP ’14, pages 605–620, Washington, DC, USA, 2014. IEEE Computer Society. [42] Trevor Jim

  20. PROCEEDINGS OF INTERNATIONAL CONFERENCE ON ORAL EDUCATION OF THE DEAF. VOLUME I. (WASHINGTON, D.C., NOVEMBER 1, 1967).

    Science.gov (United States)

    Alexander Graham Bell Association for the Deaf, Inc., Washington, DC.

    THE PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON ORAL EDUCATION OF THE DEAF ARE THE WRITTEN RECORD OF A CONFERENCE HELD AT CLARKE SCHOOL FOR THE DEAF AND LEXINGTON SCHOOL FOR THE DEAF IN JUNE 1967. VOLUME I CONTAINS THE PAPERS FROM FIVE PLENARY SESSIONS AND SEVERAL SECTIONAL MEETINGS PRESENTED BY REPRESENTATIVES FROM 16 COUNTRIES. SUBJECTS…

  1. Proceedings of the 1993 Particle Accelerator Conference Held in Washington, DC on May 17-20, 1993. Volume 5

    Science.gov (United States)

    1994-05-18

    stability. o)i-_ =o)- +I +aOc. Summarizing above relations, the net transfer of power per electron with kinetic energy W is written RI ado ;k of d method•. as... Porno . equations (3)XS) in cylindrical[V~ -lA!-]+ (Ip+2q)A coordinates for a general, Le. not necessarily azxiymanet-2a dC ric, beam. It is valid for

  2. Spatial and temporal structure of typhoid outbreaks in Washington, D.C., 1906–1909: evaluating local clustering with the Gi* statistic

    Directory of Open Access Journals (Sweden)

    Curtis Andrew

    2006-03-01

    Full Text Available Abstract Background To better understand the distribution of typhoid outbreaks in Washington, D.C., the U.S. Public Health Service (PHS conducted four investigations of typhoid fever. These studies included maps of cases reported between 1 May – 31 October 1906 – 1909. These data were entered into a GIS database and analyzed using Ripley's K-function followed by the Gi* statistic in yearly intervals to evaluate spatial clustering, the scale of clustering, and the temporal stability of these clusters. Results The Ripley's K-function indicated no global spatial autocorrelation. The Gi* statistic indicated clustering of typhoid at multiple scales across the four year time period, refuting the conclusions drawn in all four PHS reports concerning the distribution of cases. While the PHS reports suggested an even distribution of the disease, this study quantified both areas of localized disease clustering, as well as mobile larger regions of clustering. Thus, indicating both highly localized and periodic generalized sources of infection within the city. Conclusion The methodology applied in this study was useful for evaluating the spatial distribution and annual-level temporal patterns of typhoid outbreaks in Washington, D.C. from 1906 to 1909. While advanced spatial analyses of historical data sets must be interpreted with caution, this study does suggest that there is utility in these types of analyses and that they provide new insights into the urban patterns of typhoid outbreaks during the early part of the twentieth century.

  3. Washington, D.C. | Midmarket Solar Policies in the United States | Solar

    Science.gov (United States)

    development have kept SREC prices high. Recent DC solar initiatives (e.g., the Solar Advantage Plus Program ) have targeted low-income residents. Small businesses may be able to leverage resources from the DC residential and commercial customer-generators with systems powered by renewable-energy sources. DC's net

  4. U.S. Department of Energy Hydrogen and Fuel Cells Program 2016 Annual Merit Review and Peer Evaluation Report: June 6-10, 2016, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Popovich, Neil

    2016-10-01

    The fiscal year 2016 U.S. Department of Energy (DOE) Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting (AMR), in conjunction with DOE's Vehicle Technologies Office AMR, was held from June 6-10, 2015, in Washington, D.C.. This report is a summary of comments by AMR peer reviewers about the hydrogen and fuel cell projects funded by DOE's Office of Energy Efficiency and Renewable Energy.

  5. Organic Compounds in Potomac River Water Used for Public Supply near Washington, D.C., 2003-05

    Science.gov (United States)

    Brayton, Michael J.; Denver, Judith M.; Delzer, Gregory C.; Hamilton, Pixie A.

    2008-01-01

    Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including, in part, pesticides, solvents, gasoline hydrocarbons, personal care and domestic-use products, and refrigerants and propellants. A total of 85 of 277 compounds were detected at least once among the 25 samples collected approximately monthly during 2003-05 at the intake of the Washington Aqueduct, one of several community water systems on the Potomac River upstream from Washington, D.C. The diversity of compounds detected indicate a variety of different sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including treated wastewater outfalls located upstream, overland runoff, and ground-water discharge) to drinking-water supplies. Seven compounds were detected year-round in source-water intake samples, including selected herbicide compounds commonly used in the Potomac River Basin and in other agricultural areas across the United States. Two-thirds of the 26 compounds detected most commonly in source water (in at least 20 percent of the samples) also were detected most commonly in finished water (after treatment but prior to distribution). Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the detected compounds. On the basis of this screening-level assessment, adverse effects to human health are expected to be negligible (subject to limitations of available human-health benchmarks).

  6. Washington DC Metropolitan Area Drug Study Homeless and Transient Population (DC-MADST-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  7. An annotated checklist of the vascular flora of Washington County Mississippi

    Science.gov (United States)

    Field explorations have yielded 257 species new to Washington County, Mississippi and Calandrinia ciliata (Ruiz & Pav.) DC. and Ruellia nudiflora (Engelm. & Gray) Urban new to the state. An annotated list of 796 taxa for Washington County is provided and excludes 62 species that were reported from ...

  8. Organochlorine chemical residues in Northern Cardinal (Cardinalis cardinalis) eggs from Greater Washington, DC USA

    Science.gov (United States)

    Schmitt, Christopher J.; Echols, Kathy R.; Peterman, Paul; Orazio, Carl; Grimm, Christiana; Tan, Shirlee; Diggs, Nora E.; Marra, Peter P.

    2018-01-01

    Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination.

  9. Drilling history core hole DC-8

    International Nuclear Information System (INIS)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored

  10. Drilling history core hole DC-8

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored.

  11. Proceedings of the American Psychological Association for the Legislative Year 2006: Minutes of the Annual Meeting of the Council of Representatives, February 17-19, 2006, Washington, DC; and August 17 and 21, 2006, New Orleans, LA; and Minutes of the February, June, August, and December 2006 Meetings of the Board of Directors

    Science.gov (United States)

    Paige, Ruth Ullmann

    2007-01-01

    Minutes of the Annual Meeting of the Council of Representatives (February 17-19, 2006, Washington, DC; and August 17 and 21, 2006, New Orleans, LA) and of the 2006 meetings of the Board of Directors (February, June, August, and December) are provided. These minutes are the official record of the actions of the American Psychological Association…

  12. Washington DC Metropolitan Area Drug Study Household and Non-Household Populations (DC-MADSH-1991)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DC Metropolitan Area Drug Study (DCMADS) was conducted in 1991, and included special analyses of homeless and transient populations and of women delivering live...

  13. 78 FR 56852 - Exemption of Records Systems Under the Privacy Act

    Science.gov (United States)

    2013-09-16

    ... responsible for civil proceedings related to laws against drug trafficking or related financial crimes or... investigations, criminal or civil law enforcement proceedings, and other law enforcement activities; would impose... Civil Liberties, National Place Building, 1331 Pennsylvania Avenue NW., Suite 1000, Washington, DC 20530...

  14. Do Not Forget About Public Transportation: Analysis of the Association of Active Transportation to School Among Washington, DC Area Children With Parental Perceived Built Environment Measures.

    Science.gov (United States)

    Roberts, Jennifer D; Rodkey, Lindsey; Ray, Rashawn; Saelens, Brian E

    2018-03-23

    Although the active transportation (AT) indicator received an F grade on the 2016 US Report Card on Physical Activity for Children and Youth, this AT assessment excluded public transportation. An objective of the Built Environment and Active Play Study was to assess youth AT, including public transportation, among Washington, DC area children in relation to parental perceptions of neighborhood built environment (BE) variables. Questionnaires were mailed to 2000 parents of children aged 7-12 years. AT to school (ATS) was assessed with the question: "In an average school week, how many days does your child use each of the following ways to get to and from school? (a) Walk; (b) Bike; (c) Car; (d) Bus or Metro." Parental perceived BE data were obtained through questionnaire items, and logistic regression was conducted to determine if BE variables were associated with youth ATS. The sample included 144 children (50% female; average age 9.7 years; 56.3% white; 23.7% African American; 10.4% Asian American). Over 30% used ATS-public transportation 5 days per week, and nearly 13% used ATS-walking daily. Parental perceived BE variables significantly predicted youth ATS-walking and ATS-public transportation. ATS-public transportation is common among Washington, DC area youth, and parental perceptions of BE can significantly predict ATS.

  15. Population structure of the bacterial pathogen Xylella fastidiosa among street trees in Washington D.C.

    Science.gov (United States)

    Harris, Jordan Lee; Balci, Yilmaz

    2015-01-01

    Bacterial leaf scorch, associated with the bacterial pathogen Xylella fastidiosa, is a widely established and problematic disease of landscape ornamentals in Washington D.C. A multi-locus sequence typing analysis was performed using 10 housekeeping loci for X. fastidiosa strains in order to better understand the epidemiology of leaf scorch disease in this municipal environment. Samples were collected from 7 different tree species located throughout the District of Columbia, consisting of 101 samples of symptomatic and asymptomatic foliage from 84 different trees. Five strains of the bacteria were identified. Consistent with prior data, these strains were host specific, with only one strain associated with members of the red oak family, one strain associated with American elm, one strain associated with American sycamore, and two strains associated with mulberry. Strains found for asymptomatic foliage were the same as strains from the symptomatic foliage on individual trees. Cross transmission of the strains was not observed at sites with multiple species of infected trees within an approx. 25 m radius of one another. X. fastidiosa strain specificity observed for each genus of tree suggests a highly specialized host-pathogen relationship.

  16. Population structure of the bacterial pathogen Xylella fastidiosa among street trees in Washington D.C.

    Directory of Open Access Journals (Sweden)

    Jordan Lee Harris

    Full Text Available Bacterial leaf scorch, associated with the bacterial pathogen Xylella fastidiosa, is a widely established and problematic disease of landscape ornamentals in Washington D.C. A multi-locus sequence typing analysis was performed using 10 housekeeping loci for X. fastidiosa strains in order to better understand the epidemiology of leaf scorch disease in this municipal environment. Samples were collected from 7 different tree species located throughout the District of Columbia, consisting of 101 samples of symptomatic and asymptomatic foliage from 84 different trees. Five strains of the bacteria were identified. Consistent with prior data, these strains were host specific, with only one strain associated with members of the red oak family, one strain associated with American elm, one strain associated with American sycamore, and two strains associated with mulberry. Strains found for asymptomatic foliage were the same as strains from the symptomatic foliage on individual trees. Cross transmission of the strains was not observed at sites with multiple species of infected trees within an approx. 25 m radius of one another. X. fastidiosa strain specificity observed for each genus of tree suggests a highly specialized host-pathogen relationship.

  17. Doctors of Osteopathy Licensed in Washington.

    Science.gov (United States)

    Senters, Jo

    Based on information gathered by the Health Manpower Project through a survey cosponsored with the Washington Osteopathic Medical Association, this report begins with a statement of philosophy of osteopathic medicine and proceeds to comment on where such professional education is available. Remarks on the type of educational background of the…

  18. NRC regulatory information conference: Proceedings

    International Nuclear Information System (INIS)

    1989-09-01

    This volume of the report provides the proceedings from the Nuclear Regulatory Commission (NRC) Regulatory Information Conference that was held at the Mayflower Hotel, Washington, DC, on April 18, 19, and 20, 1989. This conference was held by the NRC and chaired by Dr. Thomas E. Mosley, Director, Office of Nuclear Reactor Regulations (NRR) and coordinated by S. Singh Bajwa, Chief, Technical Assistance Management Section, NRR. There were approximately 550 participants from nine countries at the conference. The countries represented were Canada, England, Italy, Japan, Mexico, Spain, Taiwan, Yugoslavia, and the United States. The NRC staff discussed with nuclear industry its regulatory philosophy and approach and the bases on which they have been established. Furthermore, the NRC staff discussed several initiatives that have been implemented recently and their bases as well as NRC's expectations for new initiatives to further improve safety. The figures contained in Appendix A to the volume correspond to the slides that were shown during the presentations. Volume 2 of this report contains the formal papers that were distributed at the beginning of the Regulatory Information Conference and other information about the conference

  19. Large Dog Relinquishment to Two Municipal Facilities in New York City and Washington, D.C.: Identifying Targets for Intervention

    Directory of Open Access Journals (Sweden)

    Emily Weiss

    2014-07-01

    Full Text Available While the overall trend in euthanasia has been decreasing nationally, large dogs are at a higher risk of euthanasia than other sized dogs in most animal shelters in the United States. We hypothesized one way to increase the lives saved with respect to these large dogs is to keep them home when possible. In order to develop solutions to decrease relinquishment, a survey was developed to learn more about the reasons owners relinquish large dogs. The survey was administered to owners relinquishing their dogs at two large municipal facilities, one in New York City and one in Washington, D.C. There were 157 responses between the two facilities. We found both significant similarities and differences between respondents and their dogs from the two cities. We identified opportunities to potentially support future relinquishers and found that targets for interventions are likely different in each community.

  20. 75 FR 19454 - Montreal, Maine & Atlantic Railway, Ltd.-Discontinuance of Service and Abandonment-in Aroostook...

    Science.gov (United States)

    2010-04-14

    ...-No. 1), 395 E Street, SW., Washington, DC 20423-0001. FOR FURTHER INFORMATION CONTACT: Joseph Dettmar.... By the Board, Rachel D. Campbell, Director, Office of Proceedings. Jeffrey Herzig, Clearance Clerk...

  1. Characteristics of Black Men Who Have Sex With Men in Baltimore, Philadelphia, and Washington, D.C.: Geographic Diversity in Socio-Demographics and HIV Transmission Risk.

    Science.gov (United States)

    German, Danielle; Brady, Kathleen; Kuo, Irene; Opoku, Jenevieve; Flynn, Colin; Patrick, Rudy; Park, Ju Nyeong; Adams, Joella; Carroll, Makeda; Simmons, Ron; Smith, Carlton R; Davis, Wendy W

    2017-07-01

    Baltimore, Philadelphia, and Washington, DC are geographically proximate cities with high HIV prevalence, including among black men who have sex with men (BMSM). Using data collected among BMSM in CDC's National HIV Behavioral Surveillance project, we compared socio-demographic characteristics, HIV risk behaviors, and service utilization to explore similarities and differences that could inform local and regional HIV intervention approaches. BMSM were recruited through venue time location sampling, June-December, 2011. Participants completed identical socio-behavioral surveys and voluntary HIV testing. Analyses were conducted among the full sample and those aged 18-24. Participants included 159 (DC), 364 (Baltimore), and 331 (Philadelphia) eligible BMSM. HIV prevalence was 23.1% (DC), 48.0% (Baltimore), 14.6% (Philadelphia) with 30.6%, 69.0%, 33.3% unrecognized HIV infection, respectively. Among BMSM 18-24, HIV prevalence was 11.1% (DC), 38.9% (Baltimore), 9.6% (Philadelphia) with unrecognized HIV infection 0.0%, 73.8%, 60.0% respectively. Compared with the other 2 cities, Baltimore participants were less likely to identify as gay/homosexual; more likely to report unemployment, incarceration, homelessness, sex exchange; and least likely to use the internet for partners. DC participants were more likely to have a college degree and employment. Philadelphia participants were more likely to report gay/homosexual identity, receptive condomless anal sex, having only main partners, and bars/clubs as partner meeting places. Sexually transmitted disease testing was universally low. Analyses showed especially high HIV prevalence among BMSM in Baltimore including among young BMSM. Socio-demographic characteristics and HIV infection correlates differed across cities but unrecognized HIV infection and unknown partner status were universally high.

  2. "Comets, Origins, and Life:” Promoting Interdisciplinary Science in Secondary and Middle Schools in the Washington, DC and Saint Louis, MO Metro Areas

    Science.gov (United States)

    Bonev, Boncho; Gibb, E. L.; Brewer, G.; Novak, R.; Mandell, A. M.; Seaton, P.; Price, J.; Long, T.; Bahar, S.; Edwards, S. S.

    2010-10-01

    Developing a full-year program to support secondary and middle school science education is a key part of the "broader impact” component of NSF Grant AST- 0807939 (PI/Co-PI Bonev/Gibb). This program is realized at two stages: (1) a professional development course for teachers is offered during the summer; (2) during the subsequent academic year we collaborate with educators in lessons planning or curriculum development as demanded in their particular schools. We successfully offered the course “ Comets, Origins, and Life: Interdisciplinary Science in the Secondary Classroom ” (45 contact hours; 3 credits) in the summers of 2009 and 2010 at the Catholic University of America. This class demonstrates how a complex hypothesis - for the delivery of water and prebiotic organic matter to early Earth - is being tested by integrating astronomy, physics, chemistry, biology, and Earth and planetary science. Collaborations with participants from the 2009 class include curriculum development within the Earth Science program in Prince Georges county, MD and strengthening science in Washington DC public schools. Our next step is to offer our class in the Saint Louis, MO area. The main challenge in our work with educators is not to present them with "interesting information", but to fit what we offer within the very particular curriculum expectations of their school districts. These curriculum expectations often vary from district to district and sometimes from year to year. We gratefully acknowledge the support by the NSF, allowing to fully integrate our research area into education. We also gratefully acknowledge our collaborations with the Goddard Center for Astrobiology and the Howard B. Owens Science Center (both in MD) in developing our class curriculum. Educators interested in this program can contact Boncho Bonev (bonev@cua.edu; for the Washington DC and Baltimore, MD areas) and Erika Gibb (gibbe@umsl.edu; for the Saint Louis, MO area).

  3. Lithologic Coring in the Lower Anacostia Tidal Watershed, Washington, D.C., July 2002

    Science.gov (United States)

    Tenbus, Frederick J.

    2003-01-01

    Little is known about the volumetric flux of ground water to the lower tidal Anacostia River, or whether ground-water flow is an important component of the contaminant load in this part of the Anacostia River. The watershed is in the eastern part of Washington, D.C., and has been subjected to over 200 years of urbanization and modifications of the river channel and nearby land areas. These anthropogenic factors, along with tidal fluctuations in the river, make ground-water data collection and interpretations difficult. The U.S. Geological Survey is cooperating with the District of Columbia Department of Health, Environmental Health Administration, Bureau of Environmental Quality, Water Quality Division, in a study to assess nonpoint-source pollution from ground water into the lower tidal Anacostia River. Lithologic cores from drilling activities conducted during July 2002 in the study area have been interpreted in the context of geologic and hydrogeologic information from previous studies in the lower Anacostia tidal watershed. These interpretations can help achieve the overall project goals of characterizing ground-water flow and contaminant load in the study area. Hydrostratigraphic units encountered during drilling generally consisted of late Pleistocene to Holocene fluvial deposits overlying Cretaceous fluvial/deltaic deposits. Cores collected in Beaverdam Creek and the Anacostia River indicated high- and low-energy environments of deposition, respectively. Two cores collected near the river showed different types of anthropogenic fill underlain by low-energy deposits, which were in turn underlain by sand and gravel. A third core collected near the river consisted primarily of sand and gravel with no artificial fill.

  4. Solar Decathlon Visitors Guide 2011, National Mall, West Potomac Park, Washington, D.C., September 23 - October 2, 2011 (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-09-01

    Guide to the student-designed houses, ten contests, exhibits, and workshops of the U.S. Department of Energy 2011 Solar Decathlon, held in Washington, D.C., from September 23 through October 2, 2011. Teams of college students designed and built the solar-powered houses on display here. They represent 13 U.S. states, five countries, and four continents. Now the teams are rising to the challenge by competing in 10 contests over nine days, with the championship trophy on the line. This is their time to shine. The 2011 teams may share a common goal - to design and build the best energy-efficient house powered by the sun - but their strategies are different. One house is made of precast concrete, while another 'dances' in response to its environment. Another house is meant to sit atop a building, proving the sky's the limit for energy innovation. Whatever your idea of sustainable living may be, you are bound to find it at the Solar Decathlon.

  5. Father Secchi Goes to Washington

    Science.gov (United States)

    McCarthy, M. F.

    1994-12-01

    In 1848 a small group of Jesuit refugees arrived at Georgetown College near Washington, D.C. Among them was a young priest, Angelo Secchi, who had finished theology studies in Rome, but had not been able to complete his final examinations. This done successfully, Secchi turned to astronomy and the new facilities of the Georgetown College Observatory, directed by its founder, Fr. James Curley. During his two years in Washington, Secchi studied physics, wrote an article on Electrical Rheometry for the Smithsonian Institution, and formed a friendship with Matthew Fontaine Maury of the U.S. Navy, who headed the Chart Service and in 1844 was named superintendent of the National Observatory. This was later named the U.S. Naval Observatory. Secchi's friendships formed during the Washington visit proved most helpful for relations between European astronomers and U.S. colleagues. Secchi, after his return to Rome constructed the Observatory of the Collegio Romano atop the baroque Church of St. Ignatius in Rome and began his work in spectral classification of stars.

  6. 78 FR 50141 - Illinois Central Railroad Company-Trackage Rights Exemption-BNSF Railway Company

    Science.gov (United States)

    2013-08-16

    ...., Washington, DC 20423-0001. In addition, a copy of each pleading must be served on Audrey L. Brodrick..., Rachel D. Campbell, Director, Office of Proceedings. Jeffrey Herzig, Clearance Clerk. [FR Doc. 2013-19937...

  7. 10 CFR 12.310 - Payment of award.

    Science.gov (United States)

    2010-01-01

    ... REGULATORY COMMISSION IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN AGENCY PROCEEDINGS Procedures for... Regulatory Commission, Washington, DC 20555. The NRC will pay the amount awarded to the applicant within 60 days. ...

  8. Scaling of economic benefits from green roof implementation in Washington, DC.

    Science.gov (United States)

    Niu, Hao; Clark, Corrie; Zhou, Jiti; Adriaens, Peter

    2010-06-01

    Green roof technology is recognized for mitigating stormwater runoff and energy consumption. Methods to overcome the cost gap between green roofs and conventional roofs were recently quantified by incorporating air quality benefits. This study investigates the impact of scaling on these benefits at the city-wide scale using Washington, DC as a test bed because of the proposed targets in the 20-20-20 vision (20 million ft(2) by 2020) articulated by Casey Trees, a nonprofit organization. Building-specific stormwater benefits were analyzed assuming two proposed policy scenarios for stormwater fees ranging from 35 to 50% reduction for green roof implementation. Heat flux calculations were used to estimate building-specific energy savings for commercial buildings. To assess benefits at the city scale, stormwater infrastructure savings were based on operational savings and size reduction due to reduced stormwater volume generation. Scaled energy infrastructure benefits were calculated using two size reductions methods for air conditioners. Avoided carbon dioxide, nitrogen oxide (NO(x)), and sulfur dioxide emissions were based on reductions in electricity and natural gas consumption. Lastly, experimental and fugacity-based estimates were used to quantify the NO(x) uptake by green roofs, which was translated to health benefits using U.S. Environmental Protection Agency models. The results of the net present value (NPV) analysis showed that stormwater infrastructure benefits totaled $1.04 million (M), while fee-based stormwater benefits were $0.22-0.32 M/y. Energy savings were $0.87 M/y, while air conditioner resizing benefits were estimated at $0.02 to $0.04 M/y and avoided emissions benefits (based on current emission trading values) were $0.09 M-0.41 M/y. Over the lifetime of the green roof (40 years), the NPV is about 30-40% less than that of conventional roofs (not including green roof maintenance costs). These considerable benefits, in concert with current and

  9. An Urban Soccer Stadium for Washington D.C.

    OpenAIRE

    Ard, John Christopher

    2014-01-01

    Expansive parking lots, miles of asphalt, and traffic jams: this is what the modern sport stadia has come to represent. Does it have to be this way? What does the future of sports stadia hold? Can we build a stadium that is better integrated to the community around it? The stadium must become a major urban element again and it must engage the urban context. D.C. United, the most storied franchise in MLS history, needs a new home. Baltimore and other locations in Maryland would gladly we...

  10. Mood Sensitivity to Seasonal Changes in African College Students Living in the Greater Washington D.C. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Alvaro Guzman

    2007-01-01

    Full Text Available The purpose of this study was to estimate the degree of seasonality and prevalence of winter- and summer-type seasonal affective disorder (SAD in African immigrant college students in comparison with African American peers. A convenience sample of 246 African immigrants and 599 African Americans studying in Washington, D.C. completed the Seasonal Pattern Assessment Questionnaire (SPAQ, which was used to calculate a global seasonality score (GSS and to estimate the prevalence of winter- and summer-type SAD. Degree of seasonality was related to a complex interaction between having general awareness of SAD, ethnicity, and gender. A greater percentage of African students reported experiencing a problem with seasonal changes relative to African American students, and had summer SAD, but the groups did not differ on GSS and winter SAD. African students reported more difficulties with seasonal changes than their African American peers, which could represent a manifestation of incomplete acclimatization to a higher latitude and temperate climate. As Africans also had a greater rate of summer SAD, this argues against acclimatization to heat.

  11. Legal Immigration Status is Associated with Depressive Symptoms among Latina Transgender Women in Washington, DC

    Directory of Open Access Journals (Sweden)

    Thespina Yamanis

    2018-06-01

    Full Text Available Latina transgender women (LTW are disproportionately vulnerable to depression, although the role of immigration/documentation status (legal authority to live/work in the U.S. in depression has not been explored. LTW in Washington, DC were recruited into a cross-sectional study via convenience sampling. Most were Spanish-speaking Central American immigrants. Participants completed rapid HIV tests, and a Spanish-language survey assessing recent depressive symptoms (PHQ-2, sociodemographics, and factors from the minority stress framework: structural stressors (documentation status, stable housing, social stressors (discrimination, fear of deportation, violence and coping resources (social support, resilience. Among immigrant LTW (n = 38, 24 were undocumented. Among the undocumented, the average PHQ-2 score was 2.7, and among the documented, the average PHQ-2 score was 1.4 (p < 0.05. Undocumented LTW were significantly more likely to experience employment discrimination, recent unstable housing, and fear of deportation. Bivariate and multiple linear regressions were performed to assess the relationship between documentation status and other correlates of past two week depressive symptoms. In multivariate analysis, PHQ-2 scores were inversely associated with being documented (p < 0.01, having an income above the federal poverty level, higher friends’ social support, and increased resiliency. Documentation status is an important correlate of depressive symptoms among LTW that should be considered within the context of health interventions.

  12. 75 FR 33736 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2010-06-15

    ...., Stop 0237, Washington, DC 20250-0237; telephone: (202) 720-2491, Fax: (202) 720-8938, or E-mail: Laurel... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 [Doc. No. AO-370-A8; AMS..., Oregon, Utah, Washington, and Wisconsin; Withdrawal of Proposed Rule AGENCY: Agricultural Marketing...

  13. 2013 NIEHS/EPA Children's Centers Annual Meeting: Protecting Children's Health for a Lifetime

    Science.gov (United States)

    This report includes proceedings from the 2013 NIEHS/EPA Children's Centers Annual Meeting, held in Washington D.C. in October, 2013. Summaries of presentations, speaker biosketches, poster abstracts, and a meeting participant list are all included.

  14. Examining the Influence of a New Light Rail Line on the Health of a Demographically Diverse and Understudied Population within the Washington, D.C. Metropolitan Area: A Protocol for a Natural Experiment Study

    Directory of Open Access Journals (Sweden)

    Jennifer D. Roberts

    2018-02-01

    Full Text Available Approximately two-thirds of adults and youth in Prince George’s County, Maryland, a suburb of Washington, D.C. are overweight or obese and less than half are achieving daily physical activity recommendations. Active transportation (AT, such as walking, biking or using public transportation (PT, is a strategic pathway to improving physical activity levels and thus reducing excess weight. Utilizing an expansion of the Washington, D.C. area transportation system with a new light rail line, the Purple Line Outcomes on Transportation (PLOT Study will exam pre- and post-Purple Line PT use, AT behaviors and attitudes and physical activity among Prince George’s County adults and youth. The PLOT Study will take advantage of this natural experiment in an area enduring significant racial/ethnic and gender-based overweight or obesity and physical inactivity disparities. While similar natural experiments on AT have been conducted in other U.S. cities, those studies lacked diverse and representative samples. To effectively evaluate these physical activity outcomes among this population, efforts will be used to recruit African American and Latino populations, the first and second most common racial/ethnic groups in Prince George’s County. Finally, the PLOT Study will also examine how contextual effects (e.g., neighborhood built environment impact PT, AT and physical activity.

  15. Examining the Influence of a New Light Rail Line on the Health of a Demographically Diverse and Understudied Population within the Washington, D.C. Metropolitan Area: A Protocol for a Natural Experiment Study

    Science.gov (United States)

    Saksvig, Brit Irene; Brachman, Micah L.; Durand, Casey P.

    2018-01-01

    Approximately two-thirds of adults and youth in Prince George’s County, Maryland, a suburb of Washington, D.C. are overweight or obese and less than half are achieving daily physical activity recommendations. Active transportation (AT), such as walking, biking or using public transportation (PT), is a strategic pathway to improving physical activity levels and thus reducing excess weight. Utilizing an expansion of the Washington, D.C. area transportation system with a new light rail line, the Purple Line Outcomes on Transportation (PLOT) Study will exam pre- and post-Purple Line PT use, AT behaviors and attitudes and physical activity among Prince George’s County adults and youth. The PLOT Study will take advantage of this natural experiment in an area enduring significant racial/ethnic and gender-based overweight or obesity and physical inactivity disparities. While similar natural experiments on AT have been conducted in other U.S. cities, those studies lacked diverse and representative samples. To effectively evaluate these physical activity outcomes among this population, efforts will be used to recruit African American and Latino populations, the first and second most common racial/ethnic groups in Prince George’s County. Finally, the PLOT Study will also examine how contextual effects (e.g., neighborhood built environment) impact PT, AT and physical activity.

  16. Proceedings of the Annual National Conference on Ada (Trademark) Technology (7th) Held in Washington, D.C. on March 13-16, 1989

    Science.gov (United States)

    1989-03-16

    encouraged by the method. to review a tested design rather than mere paper design. DCDS The method requires the use of control-flow diagrams, flowcharts ...offered. The form of tie file is: & GET_SPARE are proccdui..s and TAKEOFFTIRE & PUTONSPARE are tasks. OPERATORS The tutorial allows the beginner to proceed...learning it on many levels. The beginners learned Program structure Ada concepts and structure without (in some casesO Discrete types (wit necessary i/O

  17. Senior executive transportation & public safety summit : national traffic incident management leadership & innovation roadmap for success

    Science.gov (United States)

    2012-09-05

    This report summarizes the proceedings, findings, and recommendations from a two-day Senior Executive Summit on Transportation and Public Safety, held June 26 and 27, 2012 at the United States Department of Transportation (USDOT) in Washington, D.C. ...

  18. The effects of water filtration systems on fluoride: Washington, D.C. metropolitan area.

    Science.gov (United States)

    Jobson, M D; Grimm, S E; Banks, K; Henley, G

    2000-01-01

    According to the U.S. Environmental Protection Agency (EPA), approximately one in eight Americans is exposed to potentially harmful microbes, pesticides, lead, or radioactive radon whenever they drink a glass of tap water or take a shower. One reason for this exposure is that the water plants are aging or ill equipped to process the huge amounts of raw sewage and agricultural pollutants that are still being discharged into our drinking-water sources. Other compounds such as fluoride and chloride have been added to the community water supplies for health benefits. Water filtration systems are becoming more popular as people become concerned with pollutants in the public water supply and questions are being raised as to whether fluoride is affected by these filters. The aim of this pilot study was to assess the efficacy of three types of water filtration systems and to determine their impact on fluoride content of the water in the Washington, D.C. metropolitan area. One sample of water was collected daily for fourteen days, from one location. The sample was divided to use as a control and the test samples which were processed through various filter systems. With the use of a fluoride ion specific electrode, the fluoride concentration level was tested in all samples in order to determine the percentage of fluoride removed. This study was intended to prove that the water filtration systems did not affect the advantage offered by optimum water fluoride levels. The experimental samples were ascertained and compared to the control group, resulting in three of the four carbon filters showing statistically significant amounts of fluoride removed from the water. Both Reverse Osmosis and Distillation, as expected, removed the fluoride at a high rate.

  19. Seasonal variation of heavy metals in ambient air and precipitation at a single site in Washington, DC

    International Nuclear Information System (INIS)

    Melaku, Samuel; Morris, Vernon; Raghavan, Dharmaraj; Hosten, Charles

    2008-01-01

    Atmospheric samples of precipitation and ambient air were collected at a single site in Washington, DC, for 7 months (for ambient air samples) and 1 year (for wet deposition samples) and analyzed for arsenic, cadmium, chromium and lead. The ranges of heavy metal concentrations for 6-day wet deposition samples collected over the 1-year period were 0.20-1.3 μg/l, 0.060-5.1 μg/l, 0.062-4.6 μg/l and 0.11-3.2 μg/l for arsenic, cadmium, chromium and lead, respectively, with a precision better than 5% for more than 95% of the measurements. The ranges of heavy metal concentrations for the 6-day ambient air samples were 0.800-15.7 ng/m 3 , 1.50-30.0 ng/m 3 , 16.8-112 ng/m 3 , and 2.90-137 ng/m 3 for arsenic, cadmium, chromium and lead, respectively, with a precision better than 10%. The spread in the heavy metal concentration over the observation period suggests a high seasonal variability for heavy metal content in both ambient air and wet deposition samples. - High seasonal variability of heavy metals were observed in both ambient air and wet deposition samples

  20. Speech to Text: Today and Tomorrow. Proceedings of a Conference at Gallaudet University (Washington, D.C., September, 1988). GRI Monograh Series B, No. 2.

    Science.gov (United States)

    Harkins, Judith E., Ed.; Virvan, Barbara M., Ed.

    The conference proceedings contains 23 papers on telephone relay service, real-time captioning, and automatic speech recognition, and a glossary. The keynote address, by Representative Major R. Owens, examines current issues in federal legislation. Other papers have the following titles and authors: "Telephone Relay Service: Rationale and…

  1. The Influence of Family Dog Ownership and Parental Perceived Built Environment Measures on Children's Physical Activity within the Washington, DC Area.

    Science.gov (United States)

    Roberts, Jennifer D; Rodkey, Lindsey; Grisham, Cortney; Ray, Rashawn

    2017-11-16

    Sedentary behavior and physical inactivity are significant contributors to youth obesity in the United States. Neighborhood dog walking is an outlet for physical activity (PA). Therefore, understanding the relationship between built environment, dog ownership, and youth PA is essential. This study examined the influence of dog ownership and parental built environment perceptions on children's PA in the Washington, D.C. area. In 2014, questionnaires were mailed to 2000 parents to assess family dog ownership; children's outdoor dog walking or playing; and parental perceived built environment measures. Chi-square analyses examined differences in parental perceived built environment measures between children with and without family dogs. The sample included 144 children (50% female; average-age 9.7 years; 56.3% White; 23.7% African-American; 10.4% Asian-American; 29.9% owned dog). Only 13% and 5.6% of the children walked or played outdoors with the dog daily, respectively. A significantly greater proportion ( p -value supports children's outdoor PA through dog walking and playing.

  2. Technology 2004, Vol. 2

    Science.gov (United States)

    1995-01-01

    Proceedings from symposia of the Technology 2004 Conference, November 8-10, 1994, Washington, DC. Volume 2 features papers on computers and software, virtual reality simulation, environmental technology, video and imaging, medical technology and life sciences, robotics and artificial intelligence, and electronics.

  3. Proceedings of the Interservice/Industry Training Equipment Conference (5th) Held at Washington, DC on November 14-16, 1983. Volume 2.

    Science.gov (United States)

    1983-11-16

    sitting at the table damn near furious and he looked at me and said, "Control yourself." So I sketched out on a napkin the next verse that she should give...34 i . . . . .. . . . . . II I I I 210 the Congress? That was rhetoric, though. They proceeded to violate that before the ink was dry. But...01-0 22Z >£0: 0010: - I .4 041_ J- m W u r C, 2 0:4 WLJ’.. rWm 0: 01 Q4 0i LL 0. t.--W> 2-m0 0:0.0 0Wu >r Enp > > . Z 0 oltl Oro 2 01010, ink m20 >1

  4. Proceedings of the Annual Military Librarians’ Workshop (31st): Information Management and Intelligence Held in Washington, D.C. on 20-23 October 1987

    Science.gov (United States)

    1987-10-23

    marks an important step forward in the transformation of the worn out late Roman Empire into the new and vigorous organization of the Medieval ...presumably read and used. The fact that officers in the Byzantine Army had to be able to read and write by itself sets it apart from other medieval ... Literatura Washington: Central Intelligence Agency, 1955. 13. GRABO, Cynthia M. W~arn g•J.~jttliancxA McLean, Virginia: Association of Former Intelligence

  5. Βιβλιοκρισία:A. WEYL CARR - A. NICOLAIDES (eds., Asinou across Time: Studies in the Architecture and Murals of the Panagia Phorbiotissa, Cyprus. Dumbarton Oaks Studies, 43. Washington, DC:, 2012.

    Directory of Open Access Journals (Sweden)

    Bασιλική ΦΩΣΚΟΛΟΥ

    2015-04-01

    Full Text Available Bιβλιοκρισία:Annemarie Weyl Carr -Andréas Nicolaïdès (eds., Asinou across Time: Studies in the Architecture and Murals of the Panagia Phorbiotissa, Cyprus. Dumbarton Oaks Studies, 43. Washington, DC: Dumbarton Oaks Research Library and Collection, 2012. Pp. xii, 431.  ISBN 9780884023494.

  6. Proceedings of the Federal Transit Administration's Urban Maglev Workshop

    Science.gov (United States)

    2005-09-01

    The Federal Transit Administrations (FTA) Urban Maglev Workshop was held at FTA Headquarters in Washington, DC, on September 8-9, 2005. The key workshop goals were to review progress, share lessons learned among the grantees, and discuss future di...

  7. Report of a workshop on nuclear forces and nonproliferation Woodrow Wilson international center for scholars, Washington, DC October 28, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Pilat, Joseph F [Los Alamos National Laboratory

    2010-12-08

    A workshop sponsored by the Los Alamos National Laboratory in cooperation with the Woodrow Wilson International Center for Scholars was held at the Wilson Center in Washington, DC, on October 28, 2010. The workshop addressed evolving nuclear forces and their impacts on nonproliferation in the context of the new strategic environment, the Obama Administration's Nuclear Posture Review and the 2010 NPT Review Conference. The discussions reflected the importance of the NPR for defining the role of US nuclear forces in dealing with 21st century threats and providing guidance for National Nuclear Security Administration (NNSA) and Department of Defense (DoD) programs and, for many but not all participants, highlighted its role in the successful outcome of the NPT RevCon. There was widespread support for the NPR and its role in developing the foundations for a sustainable nuclear-weapon program that addresses nuclear weapons, infrastructure and expertise in the broader nonproliferation, disarmament and international security contexts. However, some participants raised concerns about its implementation and its long-term effectiveness and sustainability.

  8. 76 FR 40365 - Sunshine Act Meeting

    Science.gov (United States)

    2011-07-08

    ... Room, Washington, DC. STATUS: Part of the meeting will be in Open Session and the remainder of the... Financial Responsibility Requirements (Performance). Closed Session 1. Discussion of Transpacific... Discussion of the Reconstruction Proceedings and Chapter 15 Bankruptcy Petition of The Containership Company...

  9. Census Cities experiment in urban change detection. [mapping of land use changes in San Francisco, Washington D.C., Phoenix, Tucson, Boston, New Haven, Cedar Rapids, and Pontiac

    Science.gov (United States)

    Wray, J. R. (Principal Investigator); Milazzo, V. A.

    1974-01-01

    The author has identified the following significant results. Mapping of 1970 and 1972 land use from high-flight photography has been completed for all test sites: San Francisco, Washington, Phoenix, Tucson, Boston, New Haven, Cedar Rapids, and Pontiac. Area analysis of 1970 and 1972 land use has been completed for each of the mandatory urban areas. All 44 sections of the 1970 land use maps of the San Francisco test site have been officially released through USGS Open File at 1:62,500. Five thousand copies of the Washington one-sheet color 1970 land use map, census tract map, and point line identification map are being printed by USGS Publication Division. ERTS-1 imagery for each of the eight test sites is being received and analyzed. Color infrared photo enlargements at 1:100,000 of ERTS-1 MSS images of Phoenix taken on October 16, 1972 and May 2, 1973 are being analyzed to determine to what level land use and land use changes can be identified and to what extent the ERTS-1 imagery can be used in updating the 1970 aircraft photo-derived land use data base. Work is proceeding on the analysis of ERTS-1 imagery by computer manipulation of ERTS-1 MSS data in digital format. ERTS-1 CCT maps at 1:24,000 are being analyzed for two dates over Washington and Phoenix. Anniversary tape sets have been received at Purdue LARS for some additional urban test sites.

  10. A one-size-fits-all HIV prevention and education approach?: Analyzing and interpreting divergent HIV risk perceptions between African American and East African immigrant women in Washington, DC

    Science.gov (United States)

    De Jesus, Maria; Taylor, Juanita; Maine, Cathleen; Nalls, Patricia

    2015-01-01

    Background To date, there are very few comparative US studies and none in DC that distinguish between US-born and foreign-born Black women to examine and compare their perceptions of HIV risk. This qualitative study, therefore, analyzes African American and East African women’s perceptions of HIV risk in the Washington DC Metropolitan area, which has the highest AIDS rate in the US. Methods Forty in-depth, semi-structured interviews and 10 cognitive interviews were conducted among a sample of 25 African American women and 25 East African born women between October 2012 and March 2013 to examine perceptions regarding HIV risk. The in-depth semi-structured interviews were preceded by the cognitive interviews and accompanying survey. Study protocol was reviewed and approved by the American University Institutional Review Board. Results Adopting Boerma and Weir’s Proximate Determinants conceptual framework to interpret the data, the results of the study demonstrate that African American and East African immigrant women have divergent perceptions of HIV risk. While African American women ascribe HIV risk to individual-level behaviors and choices such as unprotected sex, East African women attribute HIV risk to conditions of poverty and survival. Conclusions Study findings suggest that addressing HIV prevention and education among Black women in DC will require distinct and targeted strategies that are culturally and community-centered in order to resonate with these different audiences. PMID:26766523

  11. Health-hazard-evaluation report HETA 87-376-2018, US Department of Justice, United States Marshals Service, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Reh, C.M.; Klein, M.K.

    1990-03-01

    In response to a request from the United States Marshals Service (SIC-9221) in Washington, D.C. for assistance in testing the effect of renovations to the ventilation system of their indoor firing range, lead (7439921) exposures were measured during handgun qualifying sessions. Each qualifying session of firing consisted of 60 rounds fired in 10 to 12 minutes. Personal breathing zone air samples were taken from three shooters and the range officer. Lead exposure concentrations measured were 2073, 1786, 172, and 142 micrograms of lead per cubic meter of air (microg/cu m). Eight hour time weighted average concentrations were calculated to be 194, 167, 101, and 13microg/cu m, respectively. The three shooters were therefore overexposed to lead. Bulk sampling of the sand from the bullet trap indicated it to be contaminated, containing 41% lead by weight. The authors concluded that a health hazard existed from exposure to lead. The authors recommended changes to improve the ventilation system. Following modification of the system, tests were again conducted and 11 of the 12 samples taken were below the limits of detection for the method used. The authors conclude that after modification, a hazard did not exist during qualifying sessions. The authors recommend specific measures to protect personnel from exposure to lead.

  12. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). History Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The History section of the proceedings contains the following 15 selected papers: "Attacking the Messenger: The Cartoon Campaign against 'Harper's Weekly' in the Election of 1884" (Harlen Makemson); "Fact or Friction: The Research Battle behind Advertising's Creative Revolution, 1958-1972" (Patricia M. Kinneer); "Bee So…

  13. 24 CFR 14.345 - Payment of award.

    Science.gov (United States)

    2010-04-01

    ... IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN ADMINISTRATIVE PROCEEDINGS Procedures for Considering... Equal Opportunity and Administrative Law, Room 10244, Department of Housing and Urban Development, Washington, DC 20410. A statement that review of the underlying decision is not being sought in the United...

  14. Predictability of Ice Concentration in the High-Latitude North Atlantic from Statistical Analysis of SST (Sea Surface Temperature) and Ice Concentration Data.

    Science.gov (United States)

    1987-09-01

    Nautical- Metorological Annuals (Yearbooks), Charlottenlund, Copenhagen. Jokill, 1953-67: Reports of sea ice off the Icelandic coasts (Annual reports...Proceeding of 7th annual climate diagnostic workshop (NOAA) pub. Washington, D.C., 189-195. * Weeks, W. F., 1978: Sea ice conditions in the Arctic. In

  15. Building-Resolved CFD Simulations for Greenhouse Gas Transport and Dispersion over Washington DC / Baltimore

    Science.gov (United States)

    Prasad, K.; Lopez-Coto, I.; Ghosh, S.; Mueller, K.; Whetstone, J. R.

    2015-12-01

    The North-East Corridor project aims to use a top-down inversion methodology to quantify sources of Greenhouse Gas (GHG) emissions over urban domains such as Washington DC / Baltimore with high spatial and temporal resolution. Atmospheric transport of tracer gases from an emission source to a tower mounted receptor are usually conducted using the Weather Research and Forecasting (WRF) model. For such simulations, WRF employs a parameterized turbulence model and does not resolve the fine scale dynamics generated by the flow around buildings and communities comprising a large city. The NIST Fire Dynamics Simulator (FDS) is a computational fluid dynamics model that utilizes large eddy simulation methods to model flow around buildings at length scales much smaller than is practical with WRF. FDS has the potential to evaluate the impact of complex urban topography on near-field dispersion and mixing difficult to simulate with a mesoscale atmospheric model. Such capabilities may be important in determining urban GHG emissions using atmospheric measurements. A methodology has been developed to run FDS as a sub-grid scale model within a WRF simulation. The coupling is based on nudging the FDS flow field towards that computed by WRF, and is currently limited to one way coupling performed in an off-line mode. Using the coupled WRF / FDS model, NIST will investigate the effects of the urban canopy at horizontal resolutions of 10-20 m in a domain of 12 x 12 km. The coupled WRF-FDS simulations will be used to calculate the dispersion of tracer gases in the North-East Corridor and to evaluate the upwind areas that contribute to tower observations, referred to in the inversion community as influence functions. Results of this study will provide guidance regarding the importance of explicit simulations of urban atmospheric turbulence in obtaining accurate estimates of greenhouse gas emissions and transport.

  16. Science meets public service in Washington, D.C.

    Science.gov (United States)

    Vasavada, Ashwin R.

    Same planet, different worlds—that's how many scientists see the relationship between science and government. Yet science and technology have become so infused into society that those worlds are colliding. Today, a number of national issues share a strong connection to science, from stem cells to climate change and energy to bioterrorism. For scientists who can adapt to the culture of politics, working in the collision zone can be an exciting and rewarding way to spend a year or even a career.This past year, I was one of 35 scientists in Washington serving as Congressional Science and Technology Fellows, sponsored by a number of scientific societies, including AGU. The Fellows vary widely in age and carry resumes listing Ph.D.s in not only physics, biology, and chemistry but also in Earth science, food safety, psychology, and veterinary medicine. With a group like that, weekly lunches and happy hours become the kind of broadening experience that one rarely gets in focused academic departments. And then there's the politics.

  17. 76 FR 50216 - Sunshine Act Meeting

    Science.gov (United States)

    2011-08-12

    ... Room, Washington, DC. STATUS: Part of the meeting will be in Open Session and the remainder of the... Draft Proposed Rule on Passenger Vessel Financial Responsibility Requirements. Closed 1. Staff Briefing... Proceedings and Chapter 15 Bankruptcy Petition of the Containership Company A/S. CONTACT PERSON FOR MORE...

  18. Chi Ka Sha Goes to Washington: Chickasaw Narratives on the NMAI

    Science.gov (United States)

    Hinson, Joshua Don

    2005-01-01

    This narrative describes the author's visit to Washington DC to attend the opening of the National Museum of the American Indian (NMAI). As a member of the Chickasaw, the author pondered what he would find in the museum that would represent the Chickasaw Nation. Would the museum reflect his people in all their diversity? Would he see something of…

  19. Proceedings of the Third International Workshop on Advances in Electrocorticography.

    NARCIS (Netherlands)

    Ritaccio, A.; Beauchamp, M.; Bosman, C.; Brunner, P.; Chang, E.; Crone, N.; Gunduz, A.; Gupta, D.; Knight, R.; Leuthardt, E.; Litt, B.; Moran, D.; Ojemann, J.; Parvizi, K.; Ramsey, N.; Rieger, J.; Viventi, J.; Voytek, B.; Williams, J.; Schalk, G.

    2012-01-01

    The Third International Workshop on Advances in Electrocorticography (ECoG) was convened in Washington, DC, on November 10-11, 2011. As in prior meetings, a true multidisciplinary fusion of clinicians, scientists, and engineers from many disciplines gathered to summarize contemporary experiences in

  20. Proceedings, Conference on the Defense Planning, Programming, and Budgeting System (PPBS): Past, Present, and Future Held at Washington, DC on 4-6 November 1982

    Science.gov (United States)

    1982-11-06

    They are reviewed by the Deputy Chief of Staff for Installations and Logistics to de - The DC/S for manpower then goes on to a termine the logistica ...analyses have manages its programming process. concentrated on such innovations as the De - fense Resources Board and Defense Guidance. * Discussions of... transport that fighting force to the every student of any kind of management at all beach or into battle, then all of General would say that if you

  1. Geographic Information Systems: A Primer

    Science.gov (United States)

    1990-10-01

    Albert Bargeski Page Building 1 2001 Wisconsin Ave., N.W. Washington, DC 20235 (202) 673-5594 DATA: Physical Biological Chemical National Technical...Information Systems Proceedings. ’an Francisco, CA, Oct. 26-30. ASPRS and ACSM. Vol. 1. pp. 1’ - 147. John, N. 1982. Megatrends - Ten New Directions

  2. DC electric springs with DC/DC converters

    DEFF Research Database (Denmark)

    Wang, Qingsong; Cheng, Ming; Jiang, Yunlei

    2016-01-01

    The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi-directio......The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi...... and/or constant discharging for batteries is adopted and four operating modes are analyzed as charging-positive, charging-negative, discharging-positive and discharging-negative modes. An additional mechanism for fast charging or fast discharging is also designed to secure normal operation...... of batteries. With the proposed DCES, the power fluctuations due to intermittent RESs can be passed to non-critical loads (NCLs) and batteries while power on critical loads (CLs) is kept stable. This is possibly the first attempt to design a DCES with only DC/DC converters. The performances of the proposed...

  3. 75 FR 12718 - United States Navy Restricted Area, Puget Sound, Naval Station Everett, Washington

    Science.gov (United States)

    2010-03-17

    ... . Follow the instructions for submitting comments. E-mail: david.b.olson@usace.army.mil . Include the..., Attn: CECW-CO (David B. Olson), 441 G Street, NW., Washington, DC 20314-1000. Hand Delivery/Courier... copy form. FOR FURTHER INFORMATION CONTACT: Mr. David Olson, Headquarters, Operations and Regulatory...

  4. Superfund 16: Conference and exhibition proceedings. Volume 2

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    This conference was held November 6--8, 1995 in Washington, D.C. The purpose of the conference was to provide a multidisciplinary forum dealing with state-of-the-art methods and site characterization technologies for environmental monitoring and remedial action planning of hazardous wastes. Individual papers have been processed separately for inclusion in the appropriate data bases

  5. Superfund 16: Conference and exhibition proceedings. Volume 1

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    This conference was held November 6--8, 1995 in Washington, D.C. The purpose of the conference was to provide a multidisciplinary forum dealing with state-of-the-art methods and site characterization technologies for environmental monitoring and remedial action planning of hazardous wastes. Individual papers have been processed separately for inclusion in the appropriate data bases

  6. Improving Health, Social Welfare, and Human Development Through Women's Empowerment in Developing Countries: The 2016 Girl Up Leadership Summit, Washington, DC, USA.

    Science.gov (United States)

    Mendoza, Janel

    2016-01-01

    The United Nations Foundation's Girl Up campaign, an initiative dedicated to promoting the health, education, and leadership of adolescent girls in developing communities around the world, hosted its annual Girl Up Leadership Summit in Washington, DC from July 11-13, 2016. The summit welcomed more than 275 girl empowerment and women empowerment proponents to take part in leadership training, listen to and learn from influential figures like United Nations Deputy High Commissioner for Human Rights Kate Gilmore and Treasurer of the United States Rosie Rios, as well as engage in an official lobby day in the nation's capital. Topics discussed at the summit ranged from the issue of child marriage and sexual and reproductive health rights to intersectional feminism and the importance of the next generation of global girl advocates. The purpose and, later on, achievement of the conference was the development of such leaders and Girl Up representatives. Summit attendee and Girl Up Campus Leader Janel Mendoza shares her experience as a longstanding Girl Up supporter and reflects on the preeminent conversations held during and following the summit.

  7. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

  8. 12 CFR 19.100 - Filing documents.

    Science.gov (United States)

    2010-01-01

    ... and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY RULES OF PRACTICE AND PROCEDURE... referred to the Comptroller or the administrative law judge in any proceeding under this part must be filed with the Hearing Clerk, Office of the Comptroller of the Currency, 250 E Street, SW., Washington, DC...

  9. 29 CFR 1614.308 - Practices and procedures of the Special Panel.

    Science.gov (United States)

    2010-07-01

    ... Systems Protection Board, 1120 Vermont Avenue, NW., Washington, DC 20419. One copy of each submission... 29 Labor 4 2010-07-01 2010-07-01 false Practices and procedures of the Special Panel. 1614.308... Special Panel. (a) Scope. The rules in this subpart apply to proceedings before the Special Panel. (b...

  10. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Public Relations Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The Public Relations section of the proceedings contains the following 11 selected papers: "If We Build It, Will They Come? Testing the Theory of Planned Behavior as a Predictive Model for Use in Determining How Career Counseling Centers Can Better Promote Their Facilities and Services" (Carolyn Ringer Lepre); "Student Preferences…

  11. Summer Computer Simulation Conference, Washington, DC, July 15-17, 1981, Proceedings

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    Aspects of simulation technology are discussed, taking into account microcomputers in simulation, heuristic/adaptive systems, differential equations approaches, available simulation packages, selected operations research applications, and mathematical and statistical tools. Hybrid systems are discussed along with topics of chemical sciences. Subjects related to physical and engineering sciences are explored, giving attention to aeronautics and astronautics, physical processes, nuclear/electrical power technology, advanced computational methods and systems, avionics systems, dynamic systems analysis and control, and industrial systems. Environmental sciences are considered along with biomedical systems, managerial and social sciences, questions of simulation credibility and validation, and energy systems. A description is provided of simulation facilities, and topics related to system engineering and transportation are investigated

  12. Tungsten and refractory metals 3, proceedings

    International Nuclear Information System (INIS)

    Bose, A.; Dowding, R.J.

    1996-01-01

    The Third International Conference on Tungsten and Refractory Metals was held in Greater Washington DC at the McLean Hilton, McLean Virginia, on November 15--16, 1995. This meeting was the third in a series of conferences held in the Washington DC area. The first meeting was in 1992 and was entitled ''International Conference on Tungsten and Tungsten Alloys.'' In 1994, the scope of the meeting was expanded to include other refractory metals such as molybdenum, iridium, rhenium, tantalum and niobium. The tremendous success of that meeting was the primary motivation for this Conference. The broader scope (the inclusion of other refractory metals and alloys) of the Conference was kept intact for this meeting. In fact, it was felt that the developments in the technology of these materials required a common forum for the interchange of current research information. The papers presented in this meeting examined the rapid advancements in the technology of refractory metals, with special emphasis on the processing, structure, and properties. Among the properties there was emphasis on both quasi-static and dynamic rates. Another topic that received considerable interest was the area of refractory carbides and tungsten-copper composites. One day of concurrent session was necessary to accommodate all of the presentations

  13. 78 FR 75560 - Biofuels Washington LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2013-12-12

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER14-506-000] Biofuels Washington LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding, of Biofuels...

  14. How Can Improvements Be Made to the United States Metrorail System (With a Focus on the Washington Metropolitan Area Transit Authority Metrorail System) to Enhance Safety for Its Riders

    Science.gov (United States)

    2016-06-10

    on the rail system, and recommended improvements to improve the safety of the Metrorail system. These three influences show a holistic view of the...due to special events in the area to include Washington Redskins football , Washington National baseball, and other events held in the Washington, D.C...Station in Washington, DC. The accident resulted in nine people including the train operator were killed. Emergency response agencies reported

  15. A Unidirectional DC-DC Autotransformer for DC Grid Application

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2018-03-01

    Full Text Available Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT and a unidirectional step-down DC-DC autotransformer (DUDAT are studied. The UUDAT and DUDAT are composed of a series connection of diode bridges and voltage source converters. Topologies of UUDAT and DUDAT are detailed. The harmonic and un-controllability issues are discussed. Control and possible application scenarios for UUDAT and DUDAT are depicted. DC fault isolation mechanism and the methods of dimensioning the voltage and power ratings of the components in UUDAT and DUDAT are studied. Extensive simulations on power system level and experiments on a UUDAT and DUDAT prototype verified their technical feasibility.

  16. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Media Ethics Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The Media Ethics section of the proceedings contains the following 7 selected papers: "The Ethics Agenda of the Mass Communication Professorate" (Jay Black, Bruce Garrison, Fred Fedler, and Doug White); "What Would the Editor Do? A Three-Year Study of Student-Journalists and the Naming of Rape Victims in the Press" (Kim E.…

  17. Seasonal Changes in Sleep Duration in African American and African College Students Living In Washington, D.C.

    Directory of Open Access Journals (Sweden)

    Janna Volkov

    2007-01-01

    Full Text Available Duration of nocturnal melatonin secretion, a marker of “biological night” that relates to sleep duration, is longer in winter than in summer in patients with seasonal affective disorder (SAD, but not in healthy controls. In this study of African and African American college students, we hypothesized that students who met criteria for winter SAD or subsyndromal SAD (S-SAD would report sleeping longer in winter than in summer. In addition, based on our previous observation that Africans report more “problems” with change in seasons than African Americans, we expected that the seasonal changes in sleep duration would be greater in African students than in African American students. Based on Seasonal Pattern Assessment Questionnaire (SPAQ responses, African American and African college students in Washington, D.C. (N = 575 were grouped into a winter SAD/S-SAD group or a no winter diagnosis group, and winter and summer sleep length were determined. We conducted a 2 (season × 2 (sex × 2 (ethnicity × 2 (winter diagnosis group ANCOVA on reported sleep duration, controlling for age. Contrary to our hypothesis, we found that African and African American students with winter SAD/S-SAD report sleeping longer in the summer than in the winter. No differences in seasonality of sleep were found between African and African American students. Students with winter SAD or S-SAD may need to sacrifice sleep duration in the winter, when their academic functioning/efficiency may be impaired by syndromal or subsyndromal depression, in order to meet seasonally increased academic demands.

  18. Nuclear waste - A view from Washington, DC

    International Nuclear Information System (INIS)

    Mc Cormack, M.

    1984-01-01

    The view from Washington is an optimistic one. With support of the vast amount of research, development and engineering that scientists and engineers have completed and will do in the future, this country certainly is now headed towards a successful and orderly program for handling all radioactive wastes safely and inexpensively. The high-level waste program, for instance, will require only about 2% of the cost of electricity produced from nuclear power. It is the need for the federal government to create, by law, a public corporation for handling the fuel cycle for commercial nuclear fuel. Such a Federal Nuclear Fuel Cycle Corporation (FNFCC) would handle almost all of the nuclear power fuel cycle in a manner similar to the DOE management of the fuel cycle for the weapons program. Except for the mining and milling of uranium and the fabrication of uranium (only) fuel elements, the federal government would pre-empt ownership of all facilities used in the fuel cycle and operate them by contract with private industry (as with the weapons fuel cycle). Ownership of all fissile and fertile material (and all existing and future fuel elements) would be preempted by law and vested in the FNFCC. Reprocessing fuel to extract and glassify waste for permanent geologic disposal is the most attractive method for handling spent fuel from a safety and environmental perspective. Also recycling fuel is probably more environmentally attractive than mining more uranium, especially from lower grade ores. This concept of an FNFCC has been suggested to the Administration and to some Congressional leaders. There has been no known opposition expressed, but there is some indication of a reluctance to undertake such a major problem-solving initiative in one step

  19. Improving Health, Social Welfare, and Human Development Through Women’s Empowerment in Developing Countries: The 2016 Girl Up Leadership Summit, Washington, DC, USA

    Science.gov (United States)

    Mendoza, Janel

    2016-01-01

    The United Nations Foundation’s Girl Up campaign, an initiative dedicated to promoting the health, education, and leadership of adolescent girls in developing communities around the world, hosted its annual Girl Up Leadership Summit in Washington, DC from July 11-13, 2016. The summit welcomed more than 275 girl empowerment and women empowerment proponents to take part in leadership training, listen to and learn from influential figures like United Nations Deputy High Commissioner for Human Rights Kate Gilmore and Treasurer of the United States Rosie Rios, as well as engage in an official lobby day in the nation’s capital. Topics discussed at the summit ranged from the issue of child marriage and sexual and reproductive health rights to intersectional feminism and the importance of the next generation of global girl advocates. The purpose and, later on, achievement of the conference was the development of such leaders and Girl Up representatives. Summit attendee and Girl Up Campus Leader Janel Mendoza shares her experience as a longstanding Girl Up supporter and reflects on the preeminent conversations held during and following the summit. PMID:28058195

  20. A One-Size-Fits-All HIV Prevention and Education Approach?: Interpreting Divergent HIV Risk Perceptions Between African American and East African Immigrant Women in Washington, DC Using the Proximate-Determinants Conceptual Framework.

    Science.gov (United States)

    De Jesus, Maria; Taylor, Juanita; Maine, Cathleen; Nalls, Patricia

    2016-02-01

    To date, there are very few comparative US studies and none in DC that distinguish between US-born and foreign-born black women to examine and compare their perceptions of HIV risk. This qualitative study, therefore, analyzes African American and East African women's perceptions of HIV risk in the Washington DC Metropolitan area, which has the highest AIDS rate in the United States. Forty in-depth, semistructured interviews and 10 cognitive interviews were conducted among a sample of 25 African American women and 25 East African born women between October 2012 and March 2013 to examine perceptions regarding HIV risk. The in-depth semistructured interviews were preceded by the cognitive interviews and accompanying survey. Study protocol was reviewed and approved by the American University Institutional Review Board. Adopting Boerma and Weir's Proximate Determinants conceptual framework to interpret the data, the results of the study demonstrate that African American and East African immigrant women have divergent perceptions of HIV risk. Although African American women ascribe HIV risk to individual-level behaviors and choices such as unprotected sex, East African women attribute HIV risk to conditions of poverty and survival. Study findings suggest that addressing HIV prevention and education among black women in DC will require distinct and targeted strategies that are culturally and community-centered to resonate with these different audiences.

  1. Proceedings Report from the Sustainability Education Summit, September 20-21, 2010

    Science.gov (United States)

    US Department of Education, 2011

    2011-01-01

    The first-ever U. S. Department of Education summit on sustainability, "Sustainability Education Summit: Citizenship and Pathways for a Green Economy," was held on Sept. 20-21, 2010, in Washington, D.C. The Sustainability Education Summit (the Summit) brought together leaders from higher education, business and industry, labor,…

  2. Proceedings: Second international conference on managing hazardous air pollutants, 1993

    International Nuclear Information System (INIS)

    Chow, W.; Levin, L.

    1994-09-01

    This volume contains the Proceedings of the Second International Conference on Managing Hazardous Air Pollutants, held in Washington, DC on July 13--15, 1993. This conference provided an important forum for sharing information and strategies at a critical time for electric utilities in the US and elsewhere. As mandated by the Clean Air Act Amendments of 1990, the US EPA is currently conducting a risk analysis of air toxic emissions from power plants which is expected in November 1995. This conference presented the results of recent research conducted by the EPA and others that may eventually be reflected in an assessment of power plant risks. New research in a number of areas will provide important inputs to a comprehensive and credible risk assessment. These research areas include the concentrations of toxic contaminants in fossil fuels, the development and testing of improved methods for measuring toxics in power plant emissions, the effectiveness of control devices in removing specific air toxics, the transport and dispersion of toxics through the air and other media, and the potential responses of the human body and environment to exposure to these pollutants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database

  3. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Minorities and Communication Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The Minorities and Communication section of the proceedings contains the following 4 selected papers: "Differences in Media by Online Business in Black- and White-Targeted Magazines: The Potential Impact of the Digital Divide on Ad Placement" (Osei Appiah and Matthew Wagner); "Racial Stereotyping and Mass Mediated Contact"…

  4. 76 FR 71005 - Brazos River Authority; Notice of Application Accepted for Filing, Soliciting Comments, Motions...

    Science.gov (United States)

    2011-11-16

    ..., Young and Stephens Counties, Texas. g. Filed Pursuant to: Federal Power Act, 16 U.S.C. 791a-825r. h..., 888 First Street NE., Washington, DC 20426. Commenters can submit brief comments up to 6,000... motion to intervene in accordance with the Commission's Rules may become a party to the proceeding. Any...

  5. Proceedings of the Military Operations Research Society Mini-Symposium on Analysis of Tactical Transportation: Progress and Challenges (TACTRAN) Held in Alexandria, Virginia on 16-17 February 1988

    Science.gov (United States)

    1989-10-31

    V ) oLC . WL LUU ( nElI .0 .&M z : OI C) ~ QO2. E7 a~I 0 Lndlu 2 0 g w w USiII s.. LL U , CC W jc C LIr c cc Q. o C3 * L _ (r MI >I~ LI a Fiue1...Washington, DC 20301 Washington, DC 20310 Office Phone: (202)-695-9212, A/V: 225-9212 Office Phone: MR Fred W Solarczyk MR Stanley L Spaulding McDonnell

  6. Pesticides in groundwater in the Anacostia River and Rock Creek watersheds in Washington, D.C., 2005 and 2008

    Science.gov (United States)

    Koterba, Michael T.; Dieter, Cheryl A.; Miller, Cherie V.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the District Department of the Environment, conducted a groundwater-quality investigation to (a) determine the presence, concentrations, and distribution of selected pesticides in groundwater, and (b) assess the presence of pesticides in groundwater in relation to selected landscape, hydrogeologic, and groundwater-quality characteristics in the shallow groundwater underlying the Anacostia River and Rock Creek watersheds in Washington, D.C. With one exception, well depths were 100 feet or less below land surface. The USGS obtained or compiled ancillary data and information on land use (2001), subsurface sediments, and groundwater samples from 17 wells in the lower Anacostia River watershed from September through December 2005, and from 14 wells in the lower Anacostia River and lower Rock Creek watersheds from August through September 2008. Twenty-seven pesticide compounds, reflecting at least 19 different types of pesticides, were detected in the groundwater samples obtained in 2005 and 2008. No fungicides were detected. In relation to the pesticides detected, degradate compounds were as or more likely to be detected than applied (parent) compounds. The detected pesticides chiefly reflected herbicides commonly used in urban settings for non-specific weed control or insecticides used for nonspecific haustellate insects (insects with specialized mouthparts for sucking liquid) or termite-specific control. Detected pesticides included a combination of pesticides currently (2008) in use, banned or under highly restricted use, and some that had replaced the banned or restricted-use pesticides. The presence of banned and restricted-use pesticides illustrates their continued persistence and resistance to complete degradation in the environment. The presence of the replacement pesticides indicates the susceptibility of the surficial aquifer to contamination irrespective of the changes in the pesticides used. A

  7. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...

  8. Proceedings of the 10th ASIS SIG/CR classification research workshop

    DEFF Research Database (Denmark)

    This volume is a working copy of the papers presented at the 9th ASIS SIG/CR workshop on classification research, held in Washington, DC, at the ASIS Annual Meeting on Sunday 31 October 1999. The contributions printed here are working papers, and thus, not necessarily in their final form...

  9. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage......DC-DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which......-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc-dc converters are presented and summarized with comparative study of different voltage-boosting techniques....

  10. USING THE SEDIMENT QUALITY TRIAD (SQT) APPROACH TO ASSESS SEDIMENTARY CONTAMINATION IN THE ANACOSTIA RIVER, WASHINGTON

    Science.gov (United States)

    Using the Sediment Quality Triad (SQT) Approach to Assess Sedimentary Contamination in the Anacostia River, Washington, D.C. Velinsky, DJ*1, Ashley, JTF1,2, Pinkney, F.3, McGee, BL3 and Norberg-King, TJ.4 1Academy of Natural Sciences-PCER, Philadelphia, PA. 2Philadelphia Universi...

  11. A resonant dc-dc power converter assembly

    OpenAIRE

    Madsen, Mickey Pierre

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or fo...

  12. A Prospective Longitudinal Study of Seasonality in African Students Living in the Greater Washington, D.C. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Alvaro Guzman

    2007-01-01

    Full Text Available We conducted a prospective, longitudinal study of seasonality in a vulnerable population, i.e., African students who migrated to a temperate climate. Consistent with previous cross-sectional studies, we hypothesized lower mood and energy, and higher appetite and weight, in fall/winter than in spring/summer. Four cohorts of African students attending a year-long nursing school program without vacation in Washington, D.C., were assessed monthly for 1 year. Forty-three subjects (mean age = 33.46 ± 6.25, consisting of predominantly females (76.7%, completed the study. The cohorts began their academic program in different seasons (one each in winter, spring, summer, and fall, inherently minimizing confounding influences on seasonality, such as academic and immigration stress, as well as allowing adjustment for an order effect. At each assessment, students completed three 100-mm visual analog scales for mood, energy, and appetite, and were weighed on a digital scale. For each standardized dependent variable, a repeated measure ANOVA was used and, if a significant effect of month was identified, averages for spring/summer and fall/winter were compared using paired ttests. In addition, a mixed model for repeated measures was applied to raw (nonstandardized data. Body weight was significantly higher in fall/winter than in spring/summer (p < 0.01. No seasonal differences in mood, energy, or appetite were found. Benefiting from certain unique features of our cohorts allowing adjustment for order effects, this is the first study to identify a seasonal variation in body weight with a peak in winter using longitudinal monthly measurements.

  13. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Cultural and Critical Studies Division.

    Science.gov (United States)

    Association for Education in Journalism and Mass Communication.

    The Cultural and Critical Studies section of the proceedings contains the following 10 selected papers: "Sex Noise Makes Macho Magazines Both Teasing and Tedious" (Jacqueline Lambiase and Tom Reichert); "The Buccaneer as Cultural Metaphor: Pirate Mythology in Nineteenth-Century American Periodicals" (Janice Hume); "Looking…

  14. Proceedings of the Real-Time Systems Engineering Workshop

    Science.gov (United States)

    2001-08-01

    real - time systems engineering. The workshop was held as part of the SEI Symposium in...Washington, DC, during September 2000. The objective of the workshop was to identify key issues and obtain feedback from attendees concerning real - time systems engineering...and interoperability. This report summarizes the workshop in terms of foundation, management, and technical topics, and it contains a discussion related to developing a community of interest for real - time systems

  15. Tobacco retail outlet advertising practices and proximity to schools, parks and public housing affect Synar underage sales violations in Washington, DC.

    Science.gov (United States)

    Kirchner, Thomas R; Villanti, Andrea C; Cantrell, Jennifer; Anesetti-Rothermel, Andrew; Ganz, Ollie; Conway, Kevin P; Vallone, Donna M; Abrams, David B

    2015-03-01

    To examine the cross-sectional association between illicit sales of tobacco to minors, Washington DC tobacco outlet advertising practices, retail store type, the demographic make-up of the area surrounding each outlet, and the proximity of each outlet to high schools, recreational parks and public housing. Seven hundred and fifty tobacco outlets in the DC area, n=347 of which were randomly selected for inspection by the Synar Inspection Program in 2009-2010. The presence of tobacco advertisements on the interior and exterior of each outlet, and illicit tobacco sales to Synar Inspection Program youth volunteers. The presence of tobacco advertisements on the exterior of gas stations was much greater than on other retail store types (OR=6.68; 95% CI 4.05 to 11.01), as was the absence of any advertisements at bars or restaurants that sold tobacco (OR=0.33; 95% CI 0.22 to 0.52). Exterior tobacco advertisements were also more likely in predominantly African-American areas of the city (OR=3.11; 95% CI 2.28 to 4.25), and particularly likely on storefronts located closer to parks (OR=1.87; 95% CI 1.06 to 3.28). Illicit sales to minors were more common at gas stations (OR=3.01; 95% CI 1.5 to 6.3), outlets that displayed exterior tobacco advertisements closer to parks (OR=3.36; 95% CI 1.38 to 8.21), and outlets located closer to high schools in majority African-American block groups (OR=1.29; 95% CI 1.07 to 1.58). Findings demonstrate that while illicit tobacco sales to minors are occurring at acceptably low rates by Synar standards, illicit sales vary considerably by retail store type, advertising approach and proximity to high schools, parks and African-American residential areas. Future work may help inform regulatory efforts to reduce youth access at the neighbourhood, city, state and national levels. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage...

  17. Image Understanding: Proceedings of a Workshop (14th) Held at Arlington, Virginia on 23 June 1983

    Science.gov (United States)

    1983-06-01

    Washington d.c ’ br idge ’ ’connects’ fur ’theodore roosevelt memoria ’Virginia’ ’ nor times t Washington’ crossover" for "theodore...natural surfaces and their images. Fractal Hrownian functions 1 ’ ■ 186 . . do not, of course, arcounl for such largo -scale sjKitial... largo in itselt, has properties which allow considerable annlyjis to bo peilnrmed. Formulae are developed for points on the suiface of an SHGC and

  18. Nutrition across the lifespan for healthy aging: proceedings of a workshop--in brief

    Science.gov (United States)

    On September 13-14, 2016, the National Academies of Sciences, Engineering & Medicine, and Medicine's Food Forum convened a workshop in Washington DC, to (1) examine trends and patterns in aging and factors related to healthy aging in the United States with a focus on nutrition; (2) examine how nutri...

  19. 75 FR 23571 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-05-04

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... amends Sec. 39.13 by adding the following new AD: 2010-09-12 McDonnell Douglas Corporation: Amendment 39... to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  20. Proceedings: energy from urban wastes workshop, Washington, DC, September 11-12, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, A.S.; Brooks, C. (eds.)

    1979-06-01

    This workshop, for members of public interest groups, was sponsored by DOE's Urban Waste Technology Branch to provide information on the use of urban waste as an energy resource. A separate abstract was prepared for each of seven presentations plus the Summary of discussions. Two acts are included as appendices: (1) Public Law 95-238: Department of Energy Act of 1978 - Civilian Applications; and (2) Public Law 94-580: Resource Conservation and Recovery Act of 1976.

  1. Proceedings of the Acquisition Research Symposium Held in Washington, DC, October 1989

    Science.gov (United States)

    1989-10-01

    PRICE, SLIM COCOMO, JS-3, SPQR -20, Softcost-R, etc) Cost questionnaire/ interview process Cost i methodology ueslionnaire/inlerview proc«»s...investigate the applicability of several cost models for trusted code cost and schedule estimation. The models examined were: SPQR /20...unsuccessful in calibrating either SPQR /20 or Softcost-R to a trusted code development environment. SPQR /20’s Internal calibration feature

  2. Washington International Renewable Energy Conference 2008 Pledges: Methodology and Assumptions Summary

    Energy Technology Data Exchange (ETDEWEB)

    Babiuch, B.; Bilello, D. E.; Cowlin, S. C.; Mann, M.; Wise, A.

    2008-08-01

    The 2008 Washington International Renewable Energy Conference (WIREC) was held in Washington, D.C., from March 4-6, 2008, and involved nearly 9,000 people from 125 countries. The event brought together worldwide leaders in renewable energy (RE) from governments, international organizations, nongovernmental organizations, and the private sector to discuss the role that renewables can play in alleviating poverty, growing economies, and passing on a healthy planet to future generations. The conference concluded with more than 140 governments, international organizations, and private-sector representatives pledging to advance the uptake of renewable energy. The U.S. government authorized the National Renewable Energy Laboratory (NREL) to estimate the carbon dioxide (CO2) savings that would result from the pledges made at the 2008 conference. This report describes the methodology and assumptions used by NREL in quantifying the potential CO2 reductions derived from those pledges.

  3. A Biogeochemical and Spectral Analysis of Vegetation Affected by External Abiotic Agents: Results of an Investigation from Kitsap County, Washington

    Science.gov (United States)

    1990-12-01

    delineated using a remote sensing tech- nique, as proposed, the method may provide a faster and more economic means for environmental assessments and for...NC," Economic Geology, vol 78, no. 4, 1983, pp 605-617. Palazzo, A.J., and Leggett, D.C. (1986). Effect and disposition of TNT in a terrestrial...CECOM R&D Tech Lib. Ft Monmouth. NJ; CEHSC-FU-N (Krajewski). Ft Belvoir. VA: Ch of Engrs. DAEN-C’WE-M. Washington. DC:, Ch of Engrs. DAEN- MPU

  4. Processes Controlling CH2O Over the Baltimore/Washington DC Metropolitan Region: A Box Model Analysis Using Data from DISCOVER-AQ

    Science.gov (United States)

    Olson, J. R.; Crawford, J. H.; Fried, A.; Wisthaler, A.; Weinheimer, A. J.; Barrick, J. D.; Diskin, G. S.; Duncan, B. N.; Mikoviny, T.

    2012-12-01

    The first deployment for NASA's Earth Venture campaign DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) took place over the Baltimore/Washington DC region during July of 2011. Observations of CH2O in the lowest kilometer (pressure-altitude) indicate that median concentrations can vary day to day by as much as 5 ppbv. Further, variability within a single day can correlate with a number of species, including H2O, temperature, isoprene, and/or CO. The NASA Langley photochemical box model is used to examine the dominant budget terms for CH2O during DISCOVER-AQ and to diagnose the drivers of the CH2O variability. Modeling results show that the source of CH2O is largely dominated by isoprene. However, the variability of CH2O within single flight days is rarely directly correlated to isoprene. Rather, most often, CH2O variability is correlated to the oxidative capacity of the atmosphere, defined by OH and driven by OH precursors such as H2O, O3 photolysis rates, and NO. Sensitivity model runs where isoprene is held constant to daily medians show excellent ability to predict both the overall CH2O concentration (dominated by isoprene) and the variability of CH2O throughout a day (driven by variations in oxidative capacity).

  5. DC Home Appliances for DC Distribution System

    Directory of Open Access Journals (Sweden)

    MUHAMMAD KAMRAN

    2017-10-01

    Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

  6. Method development and survey of Sudan I-IV in palm oil and chilli spices in the Washington, DC, area.

    Science.gov (United States)

    Genualdi, Susie; MacMahon, Shaun; Robbins, Katherine; Farris, Samantha; Shyong, Nicole; DeJager, Lowri

    2016-01-01

    Sudan I, II, III and IV dyes are banned for use as food colorants in the United States and European Union because they are toxic and carcinogenic. These dyes have been illegally used as food additives in products such as chilli spices and palm oil to enhance their red colour. From 2003 to 2005, the European Union made a series of decisions requiring chilli spices and palm oil imported to the European Union to contain analytical reports declaring them free of Sudan I-IV. In order for the USFDA to investigate the adulteration of palm oil and chilli spices with unapproved colour additives in the United States, a method was developed for the extraction and analysis of Sudan dyes in palm oil, and previous methods were validated for Sudan dyes in chilli spices. Both LC-DAD and LC-MS/MS methods were examined for their limitations and effectiveness in identifying adulterated samples. Method validation was performed for both chilli spices and palm oil by spiking samples known to be free of Sudan dyes at concentrations close to the limit of detection. Reproducibility, matrix effects, and selectivity of the method were also investigated. Additionally, for the first time a survey of palm oil and chilli spices was performed in the United States, specifically in the Washington, DC, area. Illegal dyes, primarily Sudan IV, were detected in palm oil at concentrations from 150 to 24 000 ng ml(-1). Low concentrations (spices and are most likely a result of cross-contamination during preparation and storage and not intentional adulteration.

  7. Method development and survey of Sudan I–IV in palm oil and chilli spices in the Washington, DC, area

    Science.gov (United States)

    Genualdi, Susie; MacMahon, Shaun; Robbins, Katherine; Farris, Samantha; Shyong, Nicole; DeJager, Lowri

    2016-01-01

    Sudan I, II, III and IV dyes are banned for use as food colorants in the United States and European Union because they are toxic and carcinogenic. These dyes have been illegally used as food additives in products such as chilli spices and palm oil to enhance their red colour. From 2003 to 2005, the European Union made a series of decisions requiring chilli spices and palm oil imported to the European Union to contain analytical reports declaring them free of Sudan I–IV. In order for the USFDA to investigate the adulteration of palm oil and chilli spices with unapproved colour additives in the United States, a method was developed for the extraction and analysis of Sudan dyes in palm oil, and previous methods were validated for Sudan dyes in chilli spices. Both LC-DAD and LC-MS/MS methods were examined for their limitations and effectiveness in identifying adulterated samples. Method validation was performed for both chilli spices and palm oil by spiking samples known to be free of Sudan dyes at concentrations close to the limit of detection. Reproducibility, matrix effects, and selectivity of the method were also investigated. Additionally, for the first time a survey of palm oil and chilli spices was performed in the United States, specifically in the Washington, DC, area. Illegal dyes, primarily Sudan IV, were detected in palm oil at concentrations from 150 to 24 000 ng ml−1. Low concentrations (spices and are most likely a result of cross-contamination during preparation and storage and not intentional adulteration. PMID:26824489

  8. Proceedings of the fifth workshop on containment integrity

    Energy Technology Data Exchange (ETDEWEB)

    Parks, M.B.; Hughey, C.E. [eds.] [Sandia National Labs., Albuquerque, NM (United States)

    1992-07-01

    The Fifth Workshop on Containment integrity was held in Washington, DC, on May 12--14, 1992. The purpose of these workshops is to provide an international forum for the exchange of information on performance of containments in nuclear power plants under severe accident loadings. Severe accident investigations of existing containment designs as well as future advanced containments were presented during the workshop. There were 145 participants at the workshop from 15 countries. Individual papers have been cataloged separately.

  9. Family of multiport bidirectional DC-DC converters

    NARCIS (Netherlands)

    Tao, H.; Kotsopoulos, A.; Duarte, J.L.; Hendrix, M.A.M.

    2006-01-01

    Multiport DC-DC converters are of potential interest in applications such as generation systems utilising multiple sustainable energy sources. A family of multiport bidirectional DC-DC converters derived from a general topology is presented. The topology shows a combination of DC-link and magnetic

  10. Experiments on cleaning effects of TDC, GDC and ECR-DC in the JFT-2M tokamak

    International Nuclear Information System (INIS)

    Matsuzaki, Y.; Ogawa, H.; Miura, Y.; Ohtsuka, H.; Suzuki, N.; Yamauchi, T.; Tani, T.; Mori, M.

    1987-01-01

    The cleaning effects of Taylor-type discharge cleaning (TDC), glow discharge cleaning (GDC) and ECR discharge cleaning (ECR-DC) were studied in the JFT-2M tokamak by comparing the properties of resulting tokamak plasmas, by observing the surface composition of samples and by residual gas analysis. The operational parameters of the three discharge cleaning techniques were as follows; the plasma current for TDC is 20 kA, the DC current for GDC is 3 A and the RF power for ECR-DC is 2.3 kW. Parameters of the tokamak plasmas such as loop voltages, radiation losses, spectra emission of oxygen, maximum mean electron densities and profiles of electron temperature were improved as the TDC and ECR-DC proceeded. Changes in the surface composition of samples were measured by Auger electron spectrosopy. The results showed that during the TDC and ECR-DC oxygen was reduced, while GDC reduced mainly carbon. Residual gas analysis performed during discharge cleaning corroborated these results. (orig.)

  11. Aircraft Accident Report; Uncontrolled Impact with Terrain, Fine Airlines Flight 101, Douglas DC-8-61, N27UA, Miami, Florida, August 7, 1997

    Science.gov (United States)

    1998-06-16

    Transcolombiana de Carga ATI Air Transport International ATOS Air Transportation Oversight System ATP airline transport pilot CAM cockpit area microphone...495,000 fine against Aero Transcolombiana de Carga (ATC) for operating a DC-8-51 "over the weight limits set forth in its FAA-approved flight manual...PB98-910402 NTSB/AAR-98/02 DCA97MA059 NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. 20594 AIRCRAFT ACCIDENT REPORT c>C== UNCONTROLLED IMPACT

  12. Five-Level Active-Neutral-Point-Clamped DC/DC Converter for Medium-Voltage DC Grids

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2017-01-01

    This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...... effectively eliminate high voltage leaps caused by the dead time effect. In addition, a capacitor voltage control strategy is proposed for the 5L-ANPC dc/dc converter to ensure the balanced flying capacitor voltage and desired five-level voltage waveforms. Finally, simulation and experimental studies...

  13. Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...

  14. Crafting glass vessels: current research on the ancient glass collections in the Freer Gallery of Art, Washington, D.C.

    Science.gov (United States)

    Nagel, Alexander; McCarthy, Blythe; Bowe, Stacy

    Our knowledge of glass production in ancient Egypt has been well augmented by the publication of recently excavated materials and glass workshops, but also by more recent materials analysis, and experiments of modern glass-makers attempting to reconstruct the production process of thin-walled coreformed glass vessels. From the mounting of a prefabricated core to the final glass product our understanding of this profession has much improved. The small but well preserved glass collection of the Freer Gallery of Art in Washington, D.C. is a valid tool for examining and studying the technology and production of ancient Egyptian core formed glass vessels. Charles Lang Freer (1854-1919) acquired most of the material from Giovanni Dattari in Cairo in 1909. Previously the glass had received only limited discussion, suggesting that most of these vessels were produced in the 18th Dynasty in the 15th and 14th centuries BCE, while others date from the Hellenistic period and later. In an ongoing project we conducted computed radiography in conjunction with qualitative x-ray fluorescence analysis on a selected group of vessels to understand further aspects of the ancient production process. This paper will provide an overview of our recent research and present our data-gathering process and preliminary results. How can the examinations of core formed glass vessels in the Freer Gallery contribute to our understanding of ancient glass production and technology? By focusing on new ways of looking at old assumptions using the Freer Gallery glass collections, we hope to increase understanding of the challenges of the production process of core-vessel technology as represented by these vessels.

  15. IGBT Based DC/DC Converter

    Directory of Open Access Journals (Sweden)

    M. Akherraz

    1997-12-01

    Full Text Available This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high  frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.

  16. Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2014-01-01

    A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...

  17. Three new DC-to-DC Single-Switch Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2017-06-01

    Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.

  18. Design and construction of a DC high-brightness laser driven electron gun

    Science.gov (United States)

    Zhao, K.; Geng, R. L.; Wang, L. F.; Zhang, B. C.; Yu, J.; Wang, T.; Wu, G. F.; Song, J. H.; Chen, J. E.

    1996-02-01

    A DC high-brightness laser driven photoemissive electron gun is being developed at Peking University, in order to produce 50-100 ps electron bunches of high quality. The gun consists of a photocathode preparation chamber and a DC acceleration cavity. Different ways of fabricating photocathodes, such as chemical vapor deposition, ion beam implantation and ion beam enhanced deposition, can be adopted. The acceleration gap is designed with the aid of simulation codes EGUN and POISSON. The laser system is a mode-locked Nd-YAG oscillator proceeded by an amplifier at 10 Hz repetition rate, which can deliver three different wavelengths (1064/532/266 nm). The combination of a superconducting cavity with the photocathode preparation chamber is also discussed in this paper.

  19. 75 FR 60602 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-10-01

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... adding the following new AD: 2010-20-14 McDonnell Douglas Corporation: Amendment 39-16449. Docket No. FAA... the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD. (1) McDonnell Douglas Corporation...

  20. 75 FR 38943 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-07-07

    ...-0672; Directorate Identifier 2010-NM-047-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0672; Directorate Identifier 2010-NM-047-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10...

  1. Intelligent Network-Centric Sensors Development Program

    Science.gov (United States)

    2012-07-31

    Vasconcelos , W.; Sleeman, D.; Colley, S.; Porta, T.L. An ontology-based approach to sensor-mission assignment. In Proceedings of First Annual Conference of...the International Technology Alliance, Washington, DC, USA, September 2007. 12. Preece, A.; Gomez, M.; Mel, G.D.; Vasconcelos , W.; Sleeman, D.; Colley...13. Preece, A.; Gomez, M.; Mel, G.D.; Vasconcelos , W.; Sleeman, D.; Colley, S.; Porta, T.L. An ontology-based approach to sensor-mission assignment

  2. 75 FR 66057 - Waybill Data Released in Three-Benchmark Rail Rate Proceedings

    Science.gov (United States)

    2010-10-27

    ... (CSX Transp. II), 584 F.3d 1076 (DC Cir. 2009), the Board modified its simplified rail rate guidelines...- Benchmark approach for smaller rail rate disputes. The Three-Benchmark method compares a challenged rate of...: The RSAM and R/VC >180 benchmarks. See Rate Guidelines--Non-Coal Proceedings, (Rate Guidelines) 1 S.T...

  3. Occurrence and Distribution of Organic Wastewater Compounds in Rock Creek Park, Washington, D.C., 2007-08

    Science.gov (United States)

    Phelan, Daniel J.; Miller, Cherie V.

    2010-01-01

    The U.S. Geological Survey, and the National Park Service Police Aviation Group, conducted a high-resolution, low-altitude aerial thermal infrared survey of the Washington, D.C. section of Rock Creek Basin within the Park boundaries to identify specific locations where warm water was discharging from seeps or pipes to the creek. Twenty-three stream sites in Rock Creek Park were selected based on the thermal infrared images. Sites were sampled during the summers of 2007 and 2008 for the analysis of organic wastewater compounds to verify potential sources of sewage and other anthropogenic wastewater. Two sets of stormwater samples were collected, on June 27-28 and September 6, 2008, at the Rock Creek at Joyce Road water-quality station using an automated sampler that began sampling when a specified stage threshold value was exceeded. Passive-sampler devices that accumulate organic chemicals over the duration of deployment were placed in July 2008 at the five locations that had the greatest number of detections of organic wastewater compounds from the June 2007 base-flow sampling. During the 2007 base-flow synoptic sampling, there were ubiquitous low-level detections of dissolved organic wastewater indicator compounds such as DEET, caffeine, HHCB, and organophosphate flame retardants at more than half of the 23 sites sampled in Rock Creek Park. Concentrations of DEET and caffeine in the tributaries to Rock Creek were variable, but in the main stem of Rock Creek, the concentrations were constant throughout the length of the creek, which likely reflects a distributed source. Organophosphate flame retardants in the main stem of Rock Creek were detected at estimated concentrations of 0.2 micrograms per liter or less, and generally did not increase with distance downstream. Overall, concentrations of most wastewater indicators in whole-water samples in the Park were similar to the concentrations found at the upstream sampling station at the Maryland/District of Columbia

  4. 75 FR 6160 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-02-08

    ...-0032; Directorate Identifier 2009-NM-213-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0032; Directorate Identifier 2009-NM-213-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  5. 75 FR 61989 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-8-31, DC-8-32, DC-8-33, DC-8-41...

    Science.gov (United States)

    2010-10-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and... to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently... the following new airworthiness directive (AD): 2010-21-03 McDonnell Douglas Corporation: Amendment 39...

  6. Proceedings of Conference on Variable-Resolution Modeling, Washington, DC, 5-6 May 1992

    Science.gov (United States)

    1992-05-01

    lag (MM Kim (S󈨘-M 881 received the B.S.IM1. and M.S.F.n degrees from Ptisan National t.’ni- veisnv. Korea , and kwmpook National Univer- sity. Koiea...position in the Department Electronics. National Fisheries University of Pusan. Pusan. Korea , research interests include artificial intelligence...with the data or the modeler/analyst/ gamer is forced to make up interactions such as fire allocation, detailed acquisition predictions, small unit

  7. Multi Bus DC-DC Converter in Electric Hybrid Vehicles

    Science.gov (United States)

    Krithika, V.; Subramaniam, C.; Sridharan, R.; Geetha, A.

    2018-04-01

    This paper is cotncerned with the design, simulation and fabrication of the prototype of a Multi bus DC- DC converter operating from 42V DC and delivering 14V DC and 260V DC. As a result, three DC buses are interconnected through a single power electronic circuitry. Such a requirement is energized in the development of a hybrid electric automobile which uses the technology of fuel cell. This is implemented by using a Bidirectional DC-DC converter configuration which is ideally suitable for multiple outputs with mutual electrical isolation. For the sake of reduced size and cost of step-up transformer, selection of a high frequency switching cycle at 10 KHz was done.

  8. Step-Up DC-DC Power Converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a step-up DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage and an input...... being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...

  9. AC-DC PFC Converter Using Combination of Flyback Converter and Full-bridge DC-DC Converter

    Directory of Open Access Journals (Sweden)

    Moh. Zaenal Efendi

    2014-06-01

    Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.

  10. Early Oscillation Detection for DC/DC Converter Fault Diagnosis

    Science.gov (United States)

    Wang, Bright L.

    2011-01-01

    The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

  11. Research borehole drilling activity for boreholes DH-18, DH-19, DC-12, DC-13, DC-14, DC-15, and deepening of existing borehole DC-7

    International Nuclear Information System (INIS)

    1979-09-01

    This report is an environmental evaluation of the impacts of proposed borehole drilling activities at the Hanford Site, northwest of Richland, Washington. The proposed action is to drill six research boreholes ranging in depth from 137 to 1372 meters (m) [250 to 4500 +- feet (ft)]. In addition, an existing borehole (DC-7) will be extended from 1249 to 1524 m (4099 to 5000 +- ft). The purpose of the US Department of Energy's (DOE) borehole drilling activities is to collect data on in situ rock formations that are considered potentialy suitable for nuclear waste repositories. The technical program efforts necessary to identify and qualify specific underground waste facility sites in candidate rock formations include geologic and hydrologic studies (seismicity and tectonics, rock structure and stratigraphy, lithology, etc.). Borehole drilling is an integral part of the geological studies and is essential to a thorough understanding of potentially suitable geologic formations. The purpose of the proposed drilling activities is to obtain data for evaluating Columbia River basalts that are being evaluated by the National Waste Terminal Storage (NWTS) Program to determine their suitability potential for nuclear waste repositories. Unavoidable impact to the environment is limited primarily to the clearing of land needed for access and drilling operations. Considerations exercised during site preparation, drilling, and subsequent site restoration will limit modification of the natural environment to the minimum required for accomplishment of test objectives

  12. Superconducting energy stabilizer with charging and discharging DC-DC converters

    International Nuclear Information System (INIS)

    Kim, S.H.; Kostecki, E.L.; DeWinkel, C.C.

    1992-01-01

    This patent describes a superconducting energy stabilizer having multiple load connections and employing DC-DC conversion for storing energy in a superconducting inductive energy storage device having a first end and a second end, and for releasing the stored energy from the superconducting inductive energy storage device to a load or loads or to a utility or an industrial electrical distribution system, the superconducting energy stabilizer having multiple load connections and employing DC-DC conversion. It comprises: energy storage cell means for supplying energy to the load, discharging DC-DC converter means for releasing energy from the superconducting inductive energy storage device to the energy storage cell means, the discharging DC-DC converter means having input terminals, output terminals, and a discharging control line means for carrying signals controlling the operation of the discharging DC-DC converter means, one of the input terminals of the discharging DC-DC converter means coupled to the first end of the superconducting energy storage device

  13. Restoring the Lost Rivers of Washington: Can a city's hydrologic past inform its future?

    OpenAIRE

    Millay, Curtis A.

    2005-01-01

    Washington, D.C., like many older U.S. cities, suffers the woes of rapid urbanization and aging infrastructure. The cityâ s combined sewer and stormwater system dumps millions of gallons of raw sewage into the Anacostia and Potomac Rivers over 70 times annually during significant rain events. While many groups, both public and private, attempt to clean the river, billions of dollars are still necessary over several years to remedy the combined sewer overfl ow (CSO) problem alone. Current pla...

  14. dc Arc Fault Effect on Hybrid ac/dc Microgrid

    Science.gov (United States)

    Fatima, Zahra

    The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

  15. Milliwatt dc/dc Inverter

    Science.gov (United States)

    Mclyman, C. W.

    1983-01-01

    Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

  16. 75 FR 63040 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-10-14

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10... following new airworthiness directive (AD): 2010-21-13 McDonnell Douglas Corporation: Amendment 39-16473... November 18, 2010. Affected ADs (b) None. Applicability (c) This AD applies to McDonnell Douglas...

  17. 75 FR 68246 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-11-05

    ...-1044; Directorate Identifier 2010-NM-033-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas..., 2007) and adding the following new AD: McDonnell Douglas Corporation: Docket No. FAA-2010-1044.... Applicability (c) This AD applies to all McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

  18. Overview of Multi-DC-Bus Solutions for DC Microgrids

    DEFF Research Database (Denmark)

    Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco

    2013-01-01

    DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...... could provide a continuative power supply to the loads. An overview of Multi-DC-Bus solutions is presented in this paper. The performances are compared on the basis of possible DC microgrid configurations, redundancy, different DC voltage levels....

  19. Proceedings of the Conference on the Environmental Effects of Explosives and Explosions (2nd) 13-14 October 1976

    Science.gov (United States)

    1977-07-25

    of contusions on the lining of the gastrointestinal track begin to occur along with petechial lung hemorrhages, The incidence and severity of these...Maryland 20640 Attn: LCDR 3. W. McConnell Director Naval Research Laboratory Washington, D.C. 20375 Attni Geoffrey 0. Thomas, Code 8410 Kenneth N. Fever

  20. DC to DC power converters and methods of controlling the same

    Science.gov (United States)

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  1. Laser Beam Shaping XIII, Proceedings of SPIE Vol. 8490

    CSIR Research Space (South Africa)

    Forbes, A

    2012-09-01

    Full Text Available .1117/12.2013615 Proc. of SPIE Vol. 8490 849001-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 10/17/2012 Terms of Use: http://spiedl.org/terms The papers included in this volume were part of the technical conference cited on the cover and title..., Bellingham, Washington 98227-0010 USA Telephone +1 360 676 3290 (Pacific Time)? Fax +1 360 647 1445 SPIE.org Copyright ? 2012, Society of Photo-Optical Instrumentation Engineers. Copying of material in this book for internal or personal use...

  2. Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2014-01-01

    Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.

  3. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    OpenAIRE

    Liwen Pan; Chengning Zhang

    2016-01-01

    This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for m...

  4. PENGGUNAAN FUZZY LOGIC UNTUK KONTROL PARALLEL CONVERTER DC-DC

    Directory of Open Access Journals (Sweden)

    Bambang Prio Hartono

    2012-09-01

    Full Text Available Abstract: Using system fuzzy logic as control  technology have been used on low load dc-dc converter with combined parallel compiled  dc-dc converter can  obtain big load.   With existence of differrence of component parameter and each parallel compiled converter can obtained different current  and voltage output.  Function of controller  for to do adjustment, so that current which is applied  to  load by each converter  can be obtained  difference error as small as possible or same. The object of research is developing design of large signal dc-dc converter which is  combined with using  FLC so that  obtain  better performance.  To get better performance have been made plant model and simulation with CDE method.  The more systematic  system and design is needed to overcome bigger load  on dc-dc converter, so that parallel  compiled current master slave control system on dc-dc converter with using fuzzy logic  controller is used. Result of  research showed that error or difference of  current  which is applied to load can handled by fuzzy logic  controller.  Technic of current and voltage controller co to do adjustment current and voltage distribution  equally to load.  Distribution of iL1,iL2 and  output voltage Vo on dc-dc  converter with load 2,25 until  7,875 and voltage  100  until 120 volt,  load current beetwen  12 until 48, % relatif  error  Vo  0,4% until  0,9%.

  5. 77 FR 24369 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

    Science.gov (United States)

    2012-04-24

    ..., VOR-A, Amdt 7 Washington, DC, Ronald Reagan Washington National, COPTER ILS OR LOC/DME RWY 1, Amdt 1 Washington, DC, Ronald Reagan Washington National, ILS OR LOC/DME RWY 1, ILS RWY 1 (SA CAT I), ILS RWY 1 (CAT II), Amdt 41 Washington, DC, Ronald Reagan Washington National, RNAV (RNP) RWY 1, Amdt 1 Washington...

  6. Full range ZVS DC-DC converter

    International Nuclear Information System (INIS)

    Upadhyay, Rinki; Badapanda, M.K.; Hannurkar, P.R.

    2011-01-01

    A 500 V, 24 Amp DC-DC converter with digital signal processor (DSP) based control and protection has been designed, fabricated and tested. Its power circuit consists of IGBT based single phase inverter bridge, ferrite transformer and diode rectifier. All IGBTs in the inverter bridge are operated in zero voltage switching (ZVS) mode to minimize switching losses thereby increasing the efficiency of the converter significantly. The efficiency of this converter is measured to be greater than 97% at full load. In a conventional full bridge inverter, typically ZVS is achieved under full load condition while at light load ZVS is lost. An auxiliary LC circuit has been intentionally incorporated in this converter to achieve ZVS even at light loaded conditions. Detailed simulation of the converter circuit is carried out and crucial waveforms have been presented in this paper. Microchip make dsPIC30F2020 DSP is employed to provide phase shifted PWMs to IGBTs in the inverter bridge. All the crucial parameters are also monitored by this DSP and in case of any unfavorable conditions, the converter is tripped off. Suitable experiments were carried out in this DC-DC converter under different loaded conditions and a close match between the simulated and experimental results were obtained. Such DC-DC converters can be connected in series or parallel for the development of solid state modular power supplies for various applications. (author)

  7. TOPOLOGICAL REVIEW AND ANALYSIS OF DC-DC BOOST CONVERTERS

    Directory of Open Access Journals (Sweden)

    V. INDRA GANDHI

    2017-06-01

    Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.

  8. Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

    Science.gov (United States)

    Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

    2018-03-01

    There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

  9. DC/DC converters for integration of double-layer condensers in onboard power supply; DC/DC-Wandler zur Einbindung von Doppelschichtkondensatoren in das Fahrzeugenergiebordnetz

    Energy Technology Data Exchange (ETDEWEB)

    Polenov, Dieter

    2010-01-15

    The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.

  10. Chaos analysis and chaotic EMI suppression of DC-DC converters

    CERN Document Server

    Zhang, Bo

    2014-01-01

    Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co

  11. Full wave dc-to-dc converter using energy storage transformers

    Science.gov (United States)

    Moore, E. T.; Wilson, T. G.

    1969-01-01

    Full wave dc-to-dc converter, for an ion thrustor, uses energy storage transformers to provide a method of dc-to-dc conversion and regulation. The converter has a high degree of physical simplicity, is lightweight and has high efficiency.

  12. Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

    CERN Document Server

    Choi, Byungcho

    2013-01-01

    This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

  13. Shock Spectrum Calculation from Acceleration Time Histories

    Science.gov (United States)

    1980-09-01

    accurate and economical . If the velocity is desired, it can be calculated with Equation A-8b. As it stands it is exact. Approx- imation will be...Washington DC; DAEN-MCE.D (R L Wight) Washington DC; DAEN.MPE-D Washington DC; DAEN- MPU . Washington DC; DARCOM; ERADCOM Tech Supp Dir. (DELSD-L) Ft

  14. Triple voltage dc-to-dc converter and method

    Science.gov (United States)

    Su, Gui-Jia

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  15. Shortcomings in Information Sharing Facilitates Transnational Organized Crime

    Science.gov (United States)

    2017-06-09

    Intelligence (Washington, DC: Government Printing Office, 2013). 7 Interagency: Of or pertaining to U.S. Government agencies and departments.20...Congress, The Intelligence Community in the 21st Century (Washington, DC: Government Printing Office, 1996), 6. 55 Geospatial- Intelligence Agency...Publication 2, Joint Intelligence . Washington, DC: Government Printing Office, 2013. Kundra, Vivek. Federal Cloud Computing Strategy. Washington, DC

  16. Application and evaluation of the WRF-CMAQ modeling system to the 2011 DISCOVER-AQ Baltimore-Washington D.C. study

    Science.gov (United States)

    Appel, W.; Gilliam, R. C.; Pouliot, G. A.; Godowitch, J. M.; Pleim, J.; Hogrefe, C.; Kang, D.; Roselle, S. J.; Mathur, R.

    2013-12-01

    The DISCOVER-AQ project (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality), is a joint collaboration between NASA, U.S. EPA and a number of other local organizations with the goal of characterizing air quality in urban areas using satellite, aircraft, vertical profiler and ground based measurements (http://discover-aq.larc.nasa.gov). In July 2011, the DISCOVER-AQ project conducted intensive air quality measurements in the Baltimore, MD and Washington, D.C. area in the eastern U.S. To take advantage of these unique data, the Community Multiscale Air Quality (CMAQ) model, coupled with the Weather Research and Forecasting (WRF) model is used to simulate the meteorology and air quality in the same region using 12-km, 4-km and 1-km horizontal grid spacings. The goal of the modeling exercise is to demonstrate the capability of the coupled WRF-CMAQ modeling system to simulate air quality at fine grid spacings in an urban area. Development of new data assimilation techniques and the use of higher resolution input data for the WRF model have been implemented to improve the meteorological results, particularly at the 4-km and 1-km grid resolutions. In addition, a number of updates to the CMAQ model were made to enhance the capability of the modeling system to accurately represent the magnitude and spatial distribution of pollutants at fine model resolutions. Data collected during the 2011 DISCOVER-AQ campaign, which include aircraft transects and spirals, ship measurements in the Chesapeake Bay, ozonesondes, tethered balloon measurements, DRAGON aerosol optical depth measurements, LIDAR measurements, and intensive ground-based site measurements, are used to evaluate results from the WRF-CMAQ modeling system for July 2011 at the three model grid resolutions. The results of the comparisons of the model results to these measurements will be presented, along with results from the various sensitivity simulations

  17. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    Science.gov (United States)

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  18. The performance of the DC motor by the PID controlling PWM DC-DC boost converter

    OpenAIRE

    Can, Erol; Sayan, Hasan Hüseyin

    2017-01-01

    This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

  19. On and off controlled resonant dc-dc power converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter comprising an input side circuit comprising a positive and a negative input terminal for receipt of an input voltage or current and an output side circuit comprising positive and negative output terminals for supply of a converter...... output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...

  20. The Topologies Research of a Soft Switching Bidirectional DC/DC Converter

    DEFF Research Database (Denmark)

    Zhang, Qi; Zhang, Yongping; Sun, Xiangdong

    2017-01-01

    A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....

  1. 75 FR 27401 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-05-17

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes... airworthiness directive (AD) for certain Model DC-9-30, DC-9-40, and DC-9-50 series airplanes. This AD requires... this AD to detect and correct the potential for an arc/spark condition to occur within the fuel boost...

  2. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    Directory of Open Access Journals (Sweden)

    Haojie Wang

    2016-07-01

    Full Text Available It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.

  3. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Yan, Wenli

    2016-01-01

    It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed...... for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load...... changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control....

  4. Using PBL to Improve Educational Outcomes and Student Satisfaction in the Teaching of DC/DC and DC/AC Converters

    Science.gov (United States)

    Martinez-Rodrigo, Fernando; Herrero-De Lucas, Luis Carlos; de Pablo, Santiago; Rey-Boue, Alexis B.

    2017-01-01

    This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results…

  5. Improved Control Strategy for T-type Isolated DC/DC Converters

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Wang, Yanbo

    2017-01-01

    T-type isolated DC/DC converters have recently attracted attention due to their numerous advantages, including few components, low cost, and symmetrical operation of transformers. This study proposes an improved control strategy for increasing the efficiency of T-type isolated DC/DC converters....... Under the proposed strategy, the primary circulating current flows through the auxiliary switches (metal–oxide–semiconductor field-effect transistors) instead of their body diodes in free-wheeling periods. Such feature can reduce conduction losses, thereby improving the efficiency of T-type isolated DC...

  6. High power density dc/dc converter: Selection of converter topology

    Science.gov (United States)

    Divan, Deepakraj M.

    1990-01-01

    The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

  7. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2016-06-01

    Full Text Available This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs. The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.

  8. Federal Information Policies: The Impact on Competitiveness. A Summary of Proceedings of a Federal Library and Information Center Committee (FLICC) Annual Forum on Federal Information Policies (5th, Washington, DC, March 7, 1988).

    Science.gov (United States)

    Brooks, Douglas C.

    This booklet summarizes the proceedings of a forum on the state of federal information policies as they relate to aiding American competitiveness in industrial and information markets at home and abroad. Speakers whose remarks are summarized include Librarian of Congress James H. Billington; New York Congressman Sherwood Boehlert, the keynote…

  9. RESONANT STEP-DOWN DC-DC POWER CONVERTERS

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant step-down DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage...... charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier by a semiconductor switch arrangement in accordance with a switch control signal to produce the converter output voltage. The resonant step-down DC-DC power converter comprises an electrical short......-circuit connection across the galvanic isolation barrier connecting, in a first case, the second negative electrode of the output capacitor to the positive input terminal of the primary side circuit or, in a second case, connecting the second positive electrode of the output capacitor to the negative input terminal...

  10. Atmel Microcontroller Based Soft Switched PWM ZVS Full Bridge DC to DC Converter

    Directory of Open Access Journals (Sweden)

    DEEPAK KUMAR NAYAK

    2010-12-01

    Full Text Available This paper deals with the simulation and implementation of soft switched PWM ZVS full bridge DC to DC converter. The 48V DC is efficiently reduced to 12V DC using a DC to DC converter. This converter has advantages like reduced switching losses, stresses and EMI. Input DC is converted into high frequency AC and it is stepped down to 12V level. Later it is rectified using a full wave rectifier. Laboratory model of microcontroller based DC to DC converter is fabricated and tested. The experimental results are compared with the simulation results.

  11. Quasi-Z-Source Half-Bridge DC-DC Converter for Photovoltaic Applications

    OpenAIRE

    Vinnikov, D; Chub, A; Husev, O; Zaķis, J

    2015-01-01

    This paper presents a novel quasi-Z-source halfbridge galvanically isolated DC-DC converter intended for the photovoltaic applications. The topology could be envisioned as an alternative to the boost half-bridge DC-DC converter but the benefit of its symmetric structure reduces the threat of transformer saturation due to the dc flux. The proposed converter features the continuous input current and could be used either with one or two input voltage sources.

  12. DC motor operation controlled from a DC/DC power converter in pulse mode with low duty cycle

    OpenAIRE

    Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana

    2016-01-01

    In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.

  13. 78 FR 15053 - Simpson Lumber Company, LLC, Shelton, Washington; Simpson Lumber Company, LLC, Tacoma, Washington...

    Science.gov (United States)

    2013-03-08

    ...,372B] Simpson Lumber Company, LLC, Shelton, Washington; Simpson Lumber Company, LLC, Tacoma, Washington; Simpson Lumber Company, LLC, Longview, Washington; Notice of Revised Determination on Reconsideration On... Reconsideration for the workers and former workers of Simpson Lumber Company, LLC, Shelton, Washington (TA-W-81...

  14. Control of the DC-DC Converter used into Energy Generation System

    International Nuclear Information System (INIS)

    Bizon, Nicu; Oproescu, Mihai

    2006-01-01

    This paper presents an investigation of the DC-DC Converter controller used into Energy Generation System. The full bridge is used into an Energy Generation System (EGS) as second power interface between the energy source and the high DC bus. The simulation results show that the DC-DC Converter behavior can be improved using a well designed PI control surface. The used Simulink models for the EGS blocks and some design considerations are presented, too. (authors)

  15. PREFACE PASREG: The 7th International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials (Washington DC, 29-31 July 2010) PASREG: The 7th International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials (Washington DC, 29-31 July 2010)

    Science.gov (United States)

    Freyhardt, Herbert; Cardwell, David; Strasik, Mike

    2010-12-01

    Large grain, (RE)BCO bulk superconductors fabricated by top seeded melt growth (TSMG) are able to generate large magnetic fields compared to conventional, iron-based permanent magnets. Following 20 years of development, these materials are now beginning to realize their considerable potential for a variety of engineering applications such as magnetic separators, flywheel energy storage and magnetic bearings. MgB2 has also continued to emerge as a potentially important bulk superconducting material for engineering applications below 20 K due to its lack of granularity and the ease with which complex shapes of this material can be fabricated. This issue of Superconductor Science and Technology contains a selection of papers presented at the 7th International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials, including MgB2, held 29th-31sy July 2010 at the Omni Shoreham Hotel, Washington DC, USA, to report progress made in this field in the previous three year period. The workshop followed those held previously in Cambridge, UK (1997), Morioka, Japan (1999), Seattle, USA (2001), Jena, Germany (2003), Tokyo, Japan (2005) and again in Cambridge, UK (2007). The scope of the seventh PASREG workshop was extended to include processing and characterization aspects of the broader spectrum of bulk high temperature superconducting (HTS) materials, including melt-cast Bi-HTS and bulk MgB2, recent developments in the field and innovative applications of bulk HTS. A total of 38 papers were presented at this workshop, of which 30 were presented in oral form and 8 were presented as posters. The organizers wish to acknowledge the efforts of Sue Butler of the University of Houston for her local organization of the workshop. The eighth PASREG workshop will be held in Taiwan in the summer of 2012.

  16. Financial implications of the accident at Three Mile Island. Oversight hearings before the Committee on Interior and Insular Affairs, House of Representatives, Ninety-Seventh Congress, First Session on financial implications of the accident at Three Mile Island, hearings held in Washington, DC, May 4-5, 1981

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    Five panel presentations and a total of 21 witnesses testified at a two-day hearing May 4-5, 1981, in Washington, DC, on the financial consequences of the Three Mile Island (TMI) accident and the economic issues of the cleanup. The committee's goal was to listen to recommendations for government response and to determine the government's proper role and whether legislation is necessary to fulfill that role. Another issue under consideration was the restart of the undamaged unit one. The hearing record includes testimony of witnesses representing the nuclear power industry, environmental groups, and the financial and insurance industries and three appendices with additional materials

  17. A Cluster Analytic Examination of Acculturation and Health Status among Asian Americans in the Washington DC Metropolitan Area, United States

    Science.gov (United States)

    Lee, Sunmin; Chen, Lu; He, Xin; Miller, Matthew J.; Juon, Hee-Soon

    2013-01-01

    Previous studies reported mixed findings on the relationship between acculturation and health status among Asian Americans due to different types of acculturation measures used or different Asian subgroups involved in various studies. We aim to fill the gap by applying multiple measures of acculturation in a diverse sample of Asian subgroups. A cross sectional study was conducted among Chinese, Korean and Vietnamese Americans in Washington D.C. Metropolitan Area to examine the association between health status and acculturation using multiple measures including the Suinn-Lew Asian Self-Identity Acculturation (SL-ASIA) scale, clusters based on responses to SL-ASIA, language preference, length of stay, age at arrival in the United Sates and self-identity. Three clusters (Asian (31%); Bicultural (47%); and American (22%)) were created by using a two-step hierarchical method and Bayesian Information Criterion values. Across all the measures, more acculturated individuals were significantly more likely to report good health than those who were less acculturated after adjusting for covariates. Specifically, those in the American cluster were 3.8 times (95% Confidence Interval (CI): 2.2, 6.6) more likely and those in the Bicultural cluster were 1.7 times more likely (95% CI: 1.1, 2.4) to report good health as compared to those in the Asian cluster. When the conventional standardized SL-ASIA summary score (range: −1.4 to 1.4) was used, a one point increase was associated with 2.2 times greater odds of reporting good health (95% CI: 1.5, 3.2). However, the interpretation may be challenging due to uncertainty surrounding the meaning of a one point increase in SL-ASIA summary score. Among all the measures used, acculturation clusters better approximated the acculturation process and provided us with a more accurate test of the association in the population. Variables included in this measure were more relevant for our study sample and may have worked together to capture the

  18. Novel composite resonance DC-DC converter with voltage doubler rectifier

    OpenAIRE

    Kato, Hisatsugu; Matsuo, Hirohumi; Eguchi, Masaki; Sakamoto, Yukitaka; Nakaishi, Masaki

    2009-01-01

    This paper deals with a novel composite resonance DC-DC converter with the voltage doubler rectifier, which is developed to be applied to the power conditioner of the photovoltaic generation system. The proposed DC-DC converter has the current and voltage resonance functions. Therefore, the output voltage regulation can be achieved for the large variations of the input voltage and load. Also, this converter has the high power efficiency. The maximum power efficiency 96.1% can be realized.

  19. Ultra-high Efficiency DC-DC Converter using GaN Devices

    DEFF Research Database (Denmark)

    Ramachandran, Rakesh

    2016-01-01

    properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...

  20. 75 FR 61352 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-30, DC-10-30F, DC-10-30F (KC...

    Science.gov (United States)

    2010-10-05

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10...-13 McDonnell Douglas Corporation: Amendment 39-16448; Docket No. FAA-2010-0553; Directorate.... Applicability (c) This AD applies to McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A...

  1. Sliding-Mode Control of a Charger/Discharger DC/DC Converter for DC-Bus Regulation in Renewable Power Systems

    Directory of Open Access Journals (Sweden)

    Sergio Ignacio Serna-Garcés

    2016-03-01

    Full Text Available Stand-alone power systems based on renewable energy sources are used to replace generators based on fossil fuels. Those renewable power systems also require Energy Storage Devices (ESD interfaced by a charger/discharger power converter, which consist of a bidirectional DC/DC converter, and a DC bus. This paper proposes a single sliding-mode controller (SMC for the charger/discharger DC/DC converter to provide a stable DC bus voltage in any operation condition: charging or discharging the ESD, or even without any power exchange between the ESD and the DC bus. Due to the non-linear nature of the power converter, the SMC parameters are adapted on-line to ensure global stability in any operation condition. Such stability of the adaptive SMC is mathematically demonstrated using analytical expressions for the transversality, reachability and equivalent control conditions. Moreover, a design procedure for the adaptive SMC parameters is provided in order to ensure the dynamic response required for the correct operation of the load. Finally, simulations and experimental tests validate the proposed controller and design procedure.

  2. Design and Analysis of Two-Phase Boost DC-DC Converter

    OpenAIRE

    Taufik Taufik; Tadeus Gunawan; Dale Dolan; Makbul Anwari

    2010-01-01

    Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results fr...

  3. SCM Handbooks for dc-to-dc Converters

    Science.gov (United States)

    Lee, F.; Mohmoud, M.; Yu, Y.

    1984-01-01

    Two documents aid in design of control modules for dc-to-dc converters. Features of SCM include: Adaptive stability, power component stress limiting, implementation of various control laws, unified design approach. Analysis and quidelines contained in handbooks enable engineer to design SCM circuit and confidently predict resulting overall performance.

  4. Isolated step-down DC -DC converter for electric vehicles

    Science.gov (United States)

    Kukovinets, O. V.; Sidorov, K. M.; Yutt, V. E.

    2018-02-01

    Modern motor-vehicle industrial sector is moving rapidly now towards the electricity-driving cars production, improving their range and efficiency of components, and in particular the step-down DC/DC converter to supply the onboard circuit 12/24V of electric vehicle from the high-voltage battery. The purpose of this article - to identify the best circuitry topology to design an advanced step-down DC/DC converters with the smallest mass, volume, highest efficiency and power. And this will have a positive effect on driving distance of electric vehicle (EV). On the basis of computational research of existing and implemented circuit topologies of step-down DC/DC converters (serial resonant converter, full bridge with phase-shifting converter, LLC resonant converter) a comprehensive analysis was carried out on the following characteristics: specific volume, specific weight, power, efficiency. The data obtained was the basis for the best technical option - LLC resonant converter. The results can serve as a guide material in the process of components design of the traction equipment for electric vehicles, providing for the best technical solutions in the design and manufacturing of converting equipment, self-contained power supply systems and advanced driver assistance systems.

  5. Virginia Tech launches Energy Efficiency Partnership with Hannon Armstrong and Pepco Energy Services aimed at greening greater Washington, D.C.

    OpenAIRE

    Micale, Barbara L.

    2007-01-01

    Virginia Tech announced Monday the "Energy Efficiency Partnership of Greater Washington," a landmark initiative to tackle the problem of global warming by retrofitting existing buildings with energy efficiency products designed to decrease energy use and significantly cut carbon emissions.

  6. Augmented Reality for Maintenance and Repair (ARMAR)

    Science.gov (United States)

    2007-08-01

    implementations by leveraging more robust vision algorithms or by using fiducials. 57 Fi gu re 2 3. A ug m en te d co nt ro ls st at e di ag ra m 58...34 Proceedings of the IEEE Conference on Virtual Reality (VR 󈧇), Washington, DC, 2003, p. 199. [18] W. Friedrich , "ARVIKA-Augmented Reality for...and ACM International Symposium on Mixed and Augmented Reality (ISMAR 󈧊), Santa Barbara , CA, 2006, pp. 105-108. [33] S. G. Rao, S. J. Schmugge

  7. 75 FR 75872 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-12-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes...: We are adopting a new airworthiness directive (AD) for the McDonnell Douglas Corporation airplanes... to include an airworthiness directive (AD) that would apply to certain McDonnell Douglas Model DC-9...

  8. A Component-Reduced Zero-Voltage Switching Three-Level DC-DC Converter

    DEFF Research Database (Denmark)

    Qin, Zian; Pang, Ying; Wang, Huai

    2016-01-01

    The basic Zero-Voltage Switching (ZVS) three-level DC-DC converter has one clamping capacitor to realize the ZVS of the switches, and two clamping diodes to clamp the voltage of the clamping capacitor. In order to reduce the reverse recovery loss of the diode as well as its cost, this paper...... proposes to remove one of the clamping diodes in basic ZVS three-level DC-DC converter. With less components, the proposed converter can still have a stable clamping capacitor voltage, which is clamped at half of the dc link voltage. Moreover, the ZVS performance will be influenced by removing the clamping...

  9. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-05-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  10. Laboratory manual for pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2015-01-01

    Designed to complement a range of power electronics study resources, this unique lab manual helps students to gain a deep understanding of the operation, modeling, analysis, design, and performance of pulse-width modulated (PWM) DC-DC power converters.  Exercises focus on three essential areas of power electronics: open-loop power stages; small-signal modeling, design of feedback loops and PWM DC-DC converter control schemes; and semiconductor devices such as silicon, silicon carbide and gallium nitride. Meeting the standards required by industrial employers, the lab manual combines program

  11. A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modula......This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase...

  12. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  13. Proceedings of the Conference on the Standardization of Safety and Performance Tests for Energetic Materials. Volume 1

    Science.gov (United States)

    1977-09-01

    EE Dover, NJ 07801 DEXTER, Robert F. Bureau of Alcohol , Tobacco and Firearms 12th and Penna. Ave, N.W. Federal Bldg. RM 8233 Washington, DC...the digestion in alcoholic KOH. This point should be further investigated by developing a quantitative TLC or high performance liquid...the anti- oxydant neutralizes most of the oxidizing gas, then when the antioxydant is completely depleted, all the samples similarly began showing an

  14. Water quality in the Anacostia River, Maryland and Rock Creek, Washington, D.C.: Continuous and discrete monitoring with simulations to estimate concentrations and yields of nutrients, suspended sediment, and bacteria

    Science.gov (United States)

    Miller, Cherie V.; Chanat, Jeffrey G.; Bell, Joseph M.

    2013-01-01

    Concentrations and loading estimates for nutrients, suspended sediment, and E. coli bacteria were summarized for three water-quality monitoring stations on the Anacostia River in Maryland and one station on Rock Creek in Washington, D.C. Both streams are tributaries to the Potomac River in the Washington, D.C. metropolitan area and contribute to the Chesapeake Bay estuary. Two stations on the Anacostia River, Northeast Branch at Riverdale, Maryland and Northwest Branch near Hyattsville, Maryland, have been monitored for water quality during the study period from 2003 to 2011 and are located near the shift from nontidal to tidal conditions near Bladensburg, Maryland. A station on Paint Branch is nested above the station on the Northeast Branch Anacostia River, and has slightly less developed land cover than the Northeast and Northwest Branch stations. The Rock Creek station is located in Rock Creek Park, but the land cover in the watershed surrounding the park is urbanized. Stepwise log-linear regression models were developed to estimate the concentrations of suspended sediment, total nitrogen, total phosphorus, and E. coli bacteria from continuous field monitors. Turbidity was the strongest predictor variable for all water-quality parameters. For bacteria, water temperature improved the models enough to be included as a second predictor variable due to the strong dependence of stream metabolism on temperature. Coefficients of determination (R2) for the models were highest for log concentrations of suspended sediment (0.9) and total phosphorus (0.8 to 0.9), followed by E. coli bacteria (0.75 to 0.8), and total nitrogen (0.6). Water-quality data provided baselines for conditions prior to accelerated implementation of multiple stormwater controls in the watersheds. Counties are currently in the process of enhancing stormwater controls in both watersheds. Annual yields were estimated for suspended sediment, total nitrogen, total phosphorus, and E. coli bacteria using

  15. CISH is induced during DC development and regulates DC-mediated CTL activation.

    Science.gov (United States)

    Miah, Mohammad Alam; Yoon, Cheol-Hee; Kim, Joonoh; Jang, Jinah; Seong, Young-Rim; Bae, Yong-Soo

    2012-01-01

    The cytokine inducible SH2-domain protein (CISH) is a well-known STAT5 target gene, but its role in the immune system remains uncertain. In this study, we found that CISH is predominantly induced during dendritic cell (DC) development from mouse bone marrow (BM) cells and plays a crucial role in type 1 DC development and DC-mediated CTL activation. CISH knockdown reduced the expression of MHC class I, co-stimulatory molecules and pro-inflammatory cytokines in BMDCs. Meanwhile, the DC yield was markedly enhanced by CISH knockdown via cell-cycle activation and reduction of cell apoptosis. Down-regulation of cell proliferation at the later stage of DC development was found to be associated with CISH-mediated negative feedback regulation of STAT5 activation. In T-cell immunity, OT-1 T-cell proliferation was significantly reduced by CISH knockdown in DCs, whereas OT-2 T-cell proliferation was not affected by CISH knockdown. CTLs generated by DC vaccination were also markedly reduced by CISH knockdown, followed by significant impairment of DC-based tumor immunotherapy. Taken together, our data suggest that CISH expression at the later stage of DC development triggers the shutdown of DC progenitor cell proliferation and facilitates DC differentiation into a potent stimulator of CTLs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A Bidirectional Multi-Port DC-DC Converter Integrating Voltage Equalizer

    DEFF Research Database (Denmark)

    Chen, Jianfei; Hou, Shiying; Deng, Fujin

    2015-01-01

    A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalize...... battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.......A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...

  17. A Current-Fed Isolated Bidirectional DC-DC Converter

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng

    2017-01-01

    This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...

  18. Bi-Directional DC-DC Converter for PHEV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Abas Goodarzi

    2011-01-31

    Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

  19. Determination of input/output characteristics of full-bridge AC/DC/DC converter for arc welding

    OpenAIRE

    Stefanov, Goce; Karadzinov, Ljupco; Sarac, Vasilija; Cingoski, Vlatko; Gelev, Saso

    2016-01-01

    This paper describes the design and practical implementation of AC/DC/DC converter in mode of arc welding. An analysis of the operation of AC/DC/DC converter and its input/output characteristics are determined with computer simulations. The practical part is consisted of AC/DC/DC converter prototype for arc welding with output power of 3 kW and switching frequency of 64 kHz. The operation of AC/DC/DC converter is validated with experimental measurements.

  20. ITAR Free Commercial-of-the-Shelf DC/DC Converter

    Science.gov (United States)

    Denzinger, Wolfgang; Hintze, Thomas

    2014-08-01

    A commercial-of-the-shelf (COTS) DC/DC converter for digital space equipment has been developed by ASP under ESA contract with special emphasis on low cost, no use of ITAR listed EEE parts like Mosfets, minimum number of rad-hard digital IC's and a design tolerance against single event effects by appropriate filtering. However, the intention to qualify this discrete converter design for a low cost FM series production was difficult due to the high up-sceening cost of EEE-parts with one lot guarantee and minimum-by. To overcome this problem, in a next step a redesign of the DC/DC converter was performed with all semiconductors like bipolar transistors, rectifiers and zener diodes packaged into hybrids. With this approach it was possible to buy a high number of less expensive wafers or dies from one lot, to perform a lot acceptance test and to integrate the dies into hybrid packages with further up- screening for FM use. The semiconductors have been packaged into three signal hybrids with 44 pins and one power hybrid with 24 pins for the dissipating transistors and rectifiers. The design of the hybrids is such, that all integrated semiconductors can be tested individually. The qualification of four EQM DC/DC converters with different combinations of output voltages has been successfully performed and two FM's have been manufactured and tested.

  1. Performance of 22.4-kW nonlaminated-frame dc series motor with chopper controller. [a dc to dc voltage converter

    Science.gov (United States)

    Schwab, J. R.

    1979-01-01

    Performance data obtained through experimental testing of a 22.4 kW traction motor using two types of excitation are presented. Ripple free dc from a motor-generator set for baseline data and pulse width modulated dc as supplied by a battery pack and chopper controller were used for excitation. For the same average values of input voltage and current, the motor power output was independent of the type of excitation. However, at the same speeds, the motor efficiency at low power output (corresponding to low duty cycle of the controller) was 5 to 10 percentage points lower on chopped dc than on ripple free dc. The chopped dc locked-rotor torque was approximately 1 to 3 percent greater than the ripple free dc torque for the same average current.

  2. Characterising and modelling extended conducted electromagnetic interference in densely packed DC-DC converter

    CSIR Research Space (South Africa)

    Grobler, Inus

    2013-09-01

    Full Text Available . The military specified DC-DC converters are applicable, spanning from 100 W handheld power managers up to 2 kW DC-DC battery chargers. Circuit layout high frequency effects as well as high frequency impedances of the power components were characterised...

  3. A New Sliding Mode Controller for DC/DC Converters in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    M. Sarvi

    2013-01-01

    Full Text Available DC/DC converters are widely used in many industrial and electrical systems. As DC/DC converters are nonlinear and time-variant systems, the application of linear control techniques for the control of these converters is not suitable. In this paper, a new sliding mode controller is proposed as the indirect control method and compared to a simple direct control method in order to control a buck converter in photovoltaic applications. The solar arrays are dependent power sources with nonlinear voltage-current characteristics under different environmental conditions (insolation and temperature. From this point of view, the DC/DC converter is particularly suitable for the application of the sliding mode control in photovoltaic application, because of its controllable states. Simulations are performed in Matlab/Simulink software. The simulation results are presented for a step change in reference voltage and input voltage as well as step load variations. The simulations results of proposed method are compared with the conventional PID controller. The results show the good performance of the proposed sliding mode controller. The proposed method can be used for the other DC/DC converter.

  4. 75 FR 58413 - Center for Scientific Review; Notice of Closed Meetings

    Science.gov (United States)

    2010-09-24

    ... evaluate grant applications. Place: The Ritz-Carlton, Washington DC, 1150 22nd Street, NW., Washington, DC... p.m. to 5 p.m. Agenda: To review and evaluate grant applications. Place: The Ritz-Carlton...Continental Hotel, 1401 Pennsylvania Avenue, NW., Washington, DC 20004. Contact Person: Eugene Carstea, PhD...

  5. 76 FR 55737 - Proposed Privacy Act Systems of Records

    Science.gov (United States)

    2011-09-08

    ...., Washington, DC 20219-0001. (4) Bureau of Engraving and Printing (BEP): 14th & C Streets, SW. Washington, DC... Street, NW., Washington, DC 20239. (9) Financial Crimes Enforcement Network (FinCEN), Vienna, VA 22183... structured around need and is determined by the person's role in the organization. Printed materials are...

  6. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  7. Sheppard-Taylor Isolated High Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

    2017-01-01

    This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can...

  8. A DC-DC Conversion Powering Scheme for the CMS Phase-1 Pixel Upgrade

    CERN Document Server

    Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Sammet, Jan Domenik; Wlochal, Michael

    2012-01-01

    The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking betwe...

  9. Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2014-01-01

    Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.

  10. Regulation of DC development and DC-mediated T-cell immunity via CISH

    OpenAIRE

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-01-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  11. Regulation of DC development and DC-mediated T-cell immunity via CISH.

    Science.gov (United States)

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-03-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  12. 12 CFR 4.4 - Washington office.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Washington office. 4.4 Section 4.4 Banks and... EXAMINERS Organization and Functions § 4.4 Washington office. The Washington office of the OCC is the main office and headquarters of the OCC. The Washington office directs OCC policy, oversees OCC operations...

  13. Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

    Science.gov (United States)

    Chrzastowski, Michael J.

    1983-01-01

    Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

  14. Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

    International Nuclear Information System (INIS)

    Li Hong; Zhang Bo; Li Zhong; Halang, Wolfgang A.; Chen Guanrong

    2009-01-01

    In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

  15. Biennial Wind Energy Conference and Workshop, 5th, Washington, DC, October 5-7, 1981, Proceedings

    Science.gov (United States)

    1982-05-01

    The results of studies funded by the Federal government to advance the state of the art of wind energy conversion systems (WECS) construction, operation, applications, and financial viability are presented. The economics of WECS were considered in terms of applicable tax laws, computer simulations of net value of WECS to utilities, and the installation of Mod-2 2.5 MW and WTS-4 4MW wind turbines near Medicine Bow, WY to test the operation of two different large WECS on the same utility grid. Potential problems of increasing penetration of WECS-produced electricity on a utility grid were explored and remedies suggested. The structural dynamics of wind turbines were analyzed, along with means to predict potential noise pollution from large WECS, and to make blade fatigue life assessments. Finally, Darrieus rotor aerodynamics were investigated, as were dynamic stall in small WECS and lightning protection for wind turbines and components.

  16. Proceedings of the AMEDD Psychology Symposium Held at Washington, DC on 27-31 October 1980

    Science.gov (United States)

    1983-12-01

    other conditions as lung cancer, major cardiovascular disease, drug and alcohol abuse, and motorcycle and automobile accidents. The remaining data in...response incompatible with anxiety is known as: 1. operant shaping. 2. reciprocal inhibition. 3. Pavlovian conditioning . 4. conditioned reflex... conditions of their service. Labelling contract evasion as a drug rehabilitation treatment failure belies the ~* .~goal of the program as a manpower

  17. Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

    Directory of Open Access Journals (Sweden)

    Sreenivasappa Veeranna Bhupasandra

    2010-01-01

    Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

  18. Analysis of high voltage step-up nonisolated DC-DC boost converters

    Science.gov (United States)

    Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

    2016-05-01

    A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

  19. Common mode noise in three-level DC-DC converters

    CSIR Research Space (South Africa)

    Grobler, Inus

    2009-09-01

    Full Text Available that three-level buck DC-DC converters in general generate much lower common mode currents than conventional two-level buck converters. Further, reductions in common mode currents are achieved by using the improved three-level topologies that have been...

  20. Analysis and Design of Bi-Directional DC-DC Converter in the Extended Run Time DC UPS System Based on Fuel Cell and Supercapacitor

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes. The deli......Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes...

  1. DC-DC power converter research for Orbiter/Station power exchange

    Science.gov (United States)

    Ehsani, M.

    1993-01-01

    This project was to produce innovative DC-DC power converter concepts which are appropriate for the power exchange between the Orbiter and the Space Station Freedom (SSF). The new converters must interface three regulated power buses on SSF, which are at different voltages, with three fuel cell power buses on the Orbiter which can be at different voltages and should be tracked independently. Power exchange is to be bi-directional between the SSF and the Orbiter. The new converters must satisfy the above operational requirements with better weight, volume, efficiency, and reliability than is available from the present conventional technology. Two families of zero current DC-DC converters were developed and successfully adapted to this application. Most of the converters developed are new and are presented.

  2. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Department of Biological Sciences, George Washington University, 333 Lisner Hall, 2023 G St. NW, Washington, DC 20052, USA; Institute for Neuroscience, George Washington University, 636 Ross Hall, 2300 I St. NW, Washington DC 20037, USA; Department of Biology, Genome Evolution Laboratory, National University ...

  3. Force Characteristics Analysis for Linear Machine with DC Field Excitations

    Directory of Open Access Journals (Sweden)

    A/L Krishna Preshant

    2018-01-01

    Full Text Available In urban regions and particularly in developing countries such as Malaysia with its ever-growing transport sector, there is the need for energy efficient systems. In urban railway systems there is a requirement of frequent braking and start/stop motion, and energy is lost during these processes. To improve the issues of the conventional braking systems, particularly in Japan, they have introduced linear induction motor techniques. The drawbacks of this method, however, is the use of permanent magnets, which not only increase the weight of the entire system but also increases magnetic cogging. Hence an alternative is required which uses the same principles as Magnetic-Levitation but using a magnet-less system. Therefore, the objective of this research is to propose an electromagnetic rail brake system and to analyze the effect of replacing permanent magnets with a magnet-less braking systems to produce a significant amount of brake thrust as compared with the permanent magnet system. The modeling and performance analysis of the model is done using Finite Element Analysis (FEA. The mechanical aspects of the model are designed on Solidworks and then imported to JMAG Software to proceed with the electro-magnetic analysis of the model. There are 3 models developed: Base Model (steel, Permanent Magnet (PM Model and DC Coil Model. The performance of the proposed 2D models developed is evaluated in terms of average force produced and motor constant square density. By comparing the values for the 3 models for the same case of 9A current supplied for a 0.1mm/s moving velocity, the base model, permanent magnet model and DC coil model produced an average force of 7.78 N, 7.55 N, and 8.34 N respectively, however, with increase in DC current supplied to the DC coil model, the average force produced is increased to 13.32 N. Thus, the advantage of the DC coil (magnet-less model, is, that the force produced can be controlled by varying the number of turns in the

  4. Reliability and Engineering of Thin-Film Photovoltaic Modules. Research forum proceedings

    Science.gov (United States)

    Ross, R. G., Jr. (Editor); Royal, E. L. (Editor)

    1985-01-01

    A Research Forum on Reliability and Engineering of Thin Film Photovoltaic Modules, under sponsorship of the Jet Propulsion Laboratory's Flat Plate Solar Array (FSA) Project and the U.S. Department of Energy, was held in Washington, D.C., on March 20, 1985. Reliability attribute investigations of amorphous silicon cells, submodules, and modules were the subjects addressed by most of the Forum presentations. Included among the reliability research investigations reported were: Arrhenius-modeled accelerated stress tests on a Si cells, electrochemical corrosion, light induced effects and their potential effects on stability and reliability measurement methods, laser scribing considerations, and determination of degradation rates and mechanisms from both laboratory and outdoor exposure tests.

  5. Sliding-mode control of single input multiple output DC-DC converter

    Science.gov (United States)

    Zhang, Libo; Sun, Yihan; Luo, Tiejian; Wan, Qiyang

    2016-10-01

    Various voltage levels are required in the vehicle mounted power system. A conventional solution is to utilize an independent multiple output DC-DC converter whose cost is high and control scheme is complicated. In this paper, we design a novel SIMO DC-DC converter with sliding mode controller. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage DC bus and middle-voltage output terminals, which endow the converter with characteristics of simple structure, low cost, and convenient control. In addition, the sliding mode control (SMC) technique applied in our converter can enhance the performances of a certain SIMO DC-DC converter topology. The high-voltage DC bus can be regarded as the main power source to the high-voltage facility of the vehicle mounted power system, and the middle-voltage output terminals can supply power to the low-voltage equipment on an automobile. In the respect of control algorithm, it is the first time to propose the SMC-PID (Proportion Integration Differentiation) control algorithm, in which the SMC algorithm is utilized and the PID control is attended to the conventional SMC algorithm. The PID control increases the dynamic ability of the SMC algorithm by establishing the corresponding SMC surface and introducing the attached integral of voltage error, which endow the sliding-control system with excellent dynamic performance. At last, we established the MATLAB/SIMULINK simulation model, tested performance of the system, and built the hardware prototype based on Digital Signal Processor (DSP). Results show that the sliding mode control is able to track a required trajectory, which has robustness against the uncertainties and disturbances.

  6. Y-Source Boost DC/DC Converter for Distributed Generation

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...

  7. SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO

    2007-07-01

    The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

  8. Multi-level cascaded DC/DC converters for PV applications

    Directory of Open Access Journals (Sweden)

    Ahmed A.A. Hafez

    2015-12-01

    Full Text Available A robust multi-level cascaded DC/DC system for Photovoltaic (PV application is advised in this article. There are three PV generators, each is coupled to a half-bridge buck cell. Each PV-generator–buck-converter channel is controlled such that maximum power is captured independently under different irradiation and temperature levels. The system operation under normal and abnormal conditions was comprehensively investigated. Internal Model Control (IMC technique was adopted for tuning the controllers. An elaborate switching modulation strategy was used to reduce the current ripple and inductor size, while maintaining high efficiency. Annotative, simple and robust remedial strategies were proposed to mitigate different anticipated faults. Comprehensive simulation results in Matlab environment were illustrated for corroborating the performance of the advised cascaded DC/DC system under normal/abnormal conditions. The proposed system enjoys the merits of independency, reduced volumetric dimensions and improved efficiency. Furthermore, the system is inherently fault-tolerant.

  9. Job Satisfaction among Information Technology Professionals in the Washington DC Area: An Analysis Based on the Minnesota Satisfaction Questionnaire

    Science.gov (United States)

    Diala, Ify S.

    2010-01-01

    Information technology (IT) has in the recent times dominated all aspect of the business world, and, for this reason, today's business environment is more challenging and more dynamic than in previous years. Therefore, this study focused on examining job satisfaction of Information Technology professionals in the D.C. area, paying particular…

  10. Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Max Rauch; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

    2014-01-01

    A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

  11. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  12. Dc-To-Dc Converter Uses Reverse Conduction Of MOSFET's

    Science.gov (United States)

    Gruber, Robert P.; Gott, Robert W.

    1991-01-01

    In modified high-power, phase-controlled, full-bridge, pulse-width-modulated dc-to-dc converters, switching devices power metal oxide/semiconductor field-effect transistors (MOSFET's). Decreases dissipation of power during switching by eliminating approximately 0.7-V forward voltage drop in anti-parallel diodes. Energy-conversion efficiency increased.

  13. Better Jobs, Brighter Futures, a Stronger Washington. Washington's Community and Technical Colleges

    Science.gov (United States)

    Washington State Board for Community and Technical Colleges, 2015

    2015-01-01

    The world is changing rapidly. With changes in technology, demographics, and workforce trends, Washington needs colleges to not only keep pace, but lead the way. Washington's 34 community and technical colleges answer that call. The community and technical colleges have proven uniquely positioned to adapt to, embrace, and ignite change. Community…

  14. 78 FR 66027 - Center for Scientific Review; Amended Notice of Meeting

    Science.gov (United States)

    2013-11-04

    ... will be held at the Ritz-Carlton Hotel, 1150 22nd Street NW., Washington, DC 20037. The meeting will..., 2013, 11:00 a.m., Washington Hilton, 1919 Connecticut Avenue, Washington, DC 20009, which was published...

  15. Development of a green mode DC/DC converter available to portable nuclear instrument

    International Nuclear Information System (INIS)

    Gao Feiyan; Wu Longxiong; Tan Wei; Tang Yaogeng

    2010-01-01

    A green mode DC/DC converter was developed which suitable to the portable nuclear instrument which is powered by battery and is sometime at stand-by mode. Some updated control approaches such as pseudo-resonant type power supply control and synchronous rectification were adopted to makethe DC/DC converter operate with low power consumption and high efficiency. The test results the battery can be prolonged with this converter. (authors)

  16. Oil spill response issues in Washington State

    International Nuclear Information System (INIS)

    Lempriere, P.R.

    1997-01-01

    Washington State statutes and regulations applicable to oil transport and oil spills were described. Specific provisions of the statutes and regulations and other relevant matters were also discussed. Among these were: (1) Washington State oil spill prevention plans, (2) Washington State oil spill contingency plans, (3) best achievable protection, (4) Intertanko's lawsuit against Washington State, (5) oil spill removal organizations, (6) certificates of financial responsibility in Washington State, (7) extent of potential liability under Washington Law, (8) disposal of cleanup materials, and (9) definition of 'qualified individuals' on marine vessels having the authority to implement removal actions

  17. 78 FR 7791 - Center for Scientific Review; Notice of Closed Meetings

    Science.gov (United States)

    2013-02-04

    ...; Notice of Closed Meetings Pursuant to section 10(d) of the Federal Advisory Committee Act, as amended (5...: Doubletree Hotel Washington, 1515 Rhode Island Avenue NW., Washington, DC 20005. Contact Person: Joanne T.... Place: Washington Plaza Hotel, 10 Thomas Circle NW., Washington, DC 20005. Contact Person: Jin Huang, Ph...

  18. A Dual-Buck–Boost AC/DC Converter for DC Nanogrid With Three Terminal Outputs

    DEFF Research Database (Denmark)

    Wu, Weimin; Wang, Houqing; Liu, Yuan

    2017-01-01

    Due to the widely used dc characterized loads and more distributed power generation sources, the dc nanogrid becomes more and more popular, and it is seen as an alternative to the ac grid. For safety considerations, the dc nanogrid should provide reliable grounding for the residential loads...... such as the low-voltage ac power system. There are three typical grounding configurations for a dc nanogrid: the united grounding, the unidirectional grounding, and the virtual isolated grounding. Each grounding configuration has its own specifications to ac/dc converters. In this paper, a dual-buck-boost ac/dc...... converter for use in the united-grounding-configuration-based dc nanogrid with three terminal outputs is proposed. The working principle of this converter is presented in detail through analyzing the equivalent circuits. Experiments are carried out to verify the theoretical analysis....

  19. Research & Implementation of AC - DC Converter with High Power Factor & High Efficiency

    Directory of Open Access Journals (Sweden)

    Hsiou-Hsian Nien

    2014-05-01

    Full Text Available In this paper, we design and develop a high power factor, high efficiency two-stage AC - DC power converter. This paper proposes a two-stage AC - DC power converter. The first stage is boost active power factor correction circuit. The latter stage is near constant frequency LLC resonant converter. In addition to traditional LLC high efficiency advantages, light-load conversion efficiency of this power converter can be improved. And it possesses high power factor and near constant frequency operating characteristics, can significantly reduce the electromagnetic interference. This paper first discusses the main structure and control manner of power factor correction circuit. And then by the LLC resonant converter equivalent model proceed to circuit analysis to determine the important parameters of the converter circuit elements. Then design a variable frequency resonant tank. The resonant frequency can change automatically on the basis of the load to reach near constant frequency operation and a purpose of high efficiency. Finally, actually design and produce an AC – DC power converter with output of 190W to verify the characteristics and feasibility of this converter. The experimental results show that in a very light load (9.5 W the efficiency is as high as 81%, the highest efficiency of 88% (90 W. Full load efficiency is 87%. At 19 W ~ 190 W power changes, the operating frequency change is only 0.4 kHz (AC 110 V and 0.3 kHz (AC 220 V.

  20. DESIGN OPTIMIZATION OF RESONANT DC-DC CONVERTERS

    OpenAIRE

    Belqasem Aljafari

    2016-01-01

    Resonant DC/DC converters are the class of converters, which have L-C resonant tank serving as a major part of the power conversion process. The fundamental concept of the resonant converter is that the circulating energy in an L-C resonant circuit is manageable by changing the operating frequency, and therefore the converter can condition the input power to the desired output voltage. The development in power conversion technology is steady demand for high power efficiency and high power den...

  1. High Voltage Coil Current Sensor for DC-DC Converters Employing DDCC

    Directory of Open Access Journals (Sweden)

    M. Drinovsky

    2015-12-01

    Full Text Available Current sensor is an integral part of every switching converter. It is used for over-current protection, regulation and in case of multiphase converters for balancing. A new high voltage current sensor for coil-based current sensing in DC-DC converters is presented. The sensor employs DDCC with high voltage input stage and gain trimming. The circuit has been simulated and implemented in 0.35 um BCD technology as part of a multiphase DC-DC converter where its function has been verified. The circuit is able to sustain common mode voltage on the input up to 40 V, it occupies 0.387*0.345 mm2 and consumes 3.2 mW typically.

  2. On the modelling of linear-assisted DC-DC voltage regulators for photovoltaic solar energy systems

    Science.gov (United States)

    Martínez-García, Herminio; García-Vílchez, Encarna

    2017-11-01

    This paper shows the modelling of linear-assisted or hybrid (linear & switching) DC/DC voltage regulators. In this kind of regulators, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching DC/DC converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC/DC converters provide. Linear-assisted DC/DC regulators are feedback systems with potential instability. Therefore, their modelling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system.

  3. A Feedback Passivation Design for DC Microgrid and Its DC/DC Converters

    Directory of Open Access Journals (Sweden)

    Feifan Ji

    2016-12-01

    Full Text Available There are difficulties in analyzing the stability of microgrids since they are located on various network structures. However, considering that the network often consists of passive elements, the passivity theory is applied in this paper to solve the above-mentioned problem. It has been formerly shown that when the network is weakly strictly positive real (WSPR, the DC microgrid is stable if all interfaces between the microgrid and converters are made to be passive, which is called interface passivity. Then, the feedback passivation method is proposed for the controller design of various DC–DC converters to achieve the interface passivity. The interface passivity is different from the passivity of closed-loop systems on which the passivity based control (PBC concentrates. The feedback passivation design is detailed for typical buck converters and boost converters in terms of conditions that the controller parameters should satisfy. The theoretical results are verified by a hardware-in-loop real-time labotray (RTLab simulation of a DC microgrid with four generators.

  4. Test Results of Selected Commercial DC/DC Converters under Cryogenic Temperatures - A Digest

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad

    2010-01-01

    DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.

  5. A Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Al-Durra, Ahmed

    2018-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant dc-dc converters, and meanwhile achieves high efficiency...... losses. The operation principles and characteristics of the proposed converter are firstly analyzed in this paper. Then the analytical solutions for the voltage gain, soft-switching, and rms currents are derived, which facilitates the parameters design and optimization. Finally, the proposed topology...... and analysis are verified with experimental results obtained from a 1-kW converter prototype....

  6. Y-source impedance-network-based isolated boost DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Town, Graham; Loh, Poh Chiang

    2014-01-01

    A dc-dc converter with very high voltage gain is proposed in this paper for any medium-power application requiring a high voltage boost with galvanic isolation. The proposed converter topology can be realized using only two switches. With this topology a very high voltage boost can be achieved even...... with a relatively low duty cycle of the switches, and the gain obtainable is presently not matched by any existing impedance network based converter operated at the same duty ratio. The proposed converter has a Y-source impedance network to boost the voltage at the intermediate dc-link side and a push......-pull transformer for square-wave AC inversion and isolation. The voltage-doubler rectifier provides a constant dc voltage at the output stage. A theoretical analysis of the converter is presented, supported by simulation and experimental results. A 250 W down-scaled prototype was implemented in the laboratory...

  7. Multilevel DC link inverter

    Science.gov (United States)

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  8. Stability analysis of a high-step-Up DC grid-connected two-stage boost DC-DC converter

    Directory of Open Access Journals (Sweden)

    El Aroudi A.

    2014-01-01

    Full Text Available High conversion ratio switching converters are used whenever there is a need to step-up dc source voltage level to a much higher output dc voltage level such as in photovoltaic systems, telecommunications and in some medical applications. A simple solution for achieving this high conversion ratio is by cascading different stages of dc-dc boost converters. The individual converters in such a cascaded system are usually designed separately applying classical design criteria. However these criteria may not be applicable for the complete cascaded system . This paper first presents a glimpse on the bifurcation behavior that a cascade connection of two boost converters can exhibit. It is shown that the desired periodic orbit can undergo period doubling leading to subharmonic oscillations and chaotic regimes. Then, in order to simplify the analysis the second stage is considered as constant current sink and design-oriented analysis is carried out to obtain stability boundaries in the parameter space by taking into account slope interactions between the state variables in the two-different stages.

  9. Studi Komparasi Fungsi Keanggotaan Fuzzy sebagai Kontroler Bidirectional DC-DC Converter pada Sistem Penyimpan Energi

    Directory of Open Access Journals (Sweden)

    Eka Prasetyono

    2015-09-01

    Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.

  10. Digitally intensive DC-DC converter for extreme space environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro-Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  11. Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

    Science.gov (United States)

    Lin, Bor-Ren

    2018-04-01

    This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

  12. A Fixed-Frequency Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede

    2017-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant DC-DC converters, and meanwhile achieves high efficiency...... and characteristics of the proposed converter are analyzed. Finally, a 1-kW converter prototype is built and the experimental results verify the theoretical analyses....

  13. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  14. Digitally intensive DC-DC converter for extreme space environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro –Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  15. DC Voltage Droop Control Implementation in the AC/DC Power Flow Algorithm: Combinational Approach

    DEFF Research Database (Denmark)

    Akhter, F.; Macpherson, D.E.; Harrison, G.P.

    2015-01-01

    of operational flexibility, as more than one VSC station controls the DC link voltage of the MTDC system. This model enables the study of the effects of DC droop control on the power flows of the combined AC/DC system for steady state studies after VSC station outages or transient conditions without needing...... to use its complete dynamic model. Further, the proposed approach can be extended to include multiple AC and DC grids for combined AC/DC power flow analysis. The algorithm is implemented by modifying the MATPOWER based MATACDC program and the results shows that the algorithm works efficiently....

  16. 75 FR 60123 - Notice of Agreements Filed

    Science.gov (United States)

    2010-09-29

    .... Coleman, Esq.; Hoppel, Mayer & Coleman; 1000 Connecticut Avenue, NW.; Washington, DC 20036. [[Page 60124...: Paul D. Coleman, Esq.; Hoppel, Mayer & Coleman; 1050 Connecticut Avenue, NW.; Tenth Floor; Washington....; Hoppel, Mayer & Coleman; 1000 Connecticut Avenue, NW.; Washington, DC 20036. Synopsis: The amendment...

  17. High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

    2017-01-01

    This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...

  18. Computer Simulation of Phase Shifted Series Resonant DC to DC Converter

    Directory of Open Access Journals (Sweden)

    P. PARVATHY

    2016-01-01

    Full Text Available This paper deals with digital simulation of phase shifted series resonant DC to DC converter using Matlab Simulink. The Simulink models for open loop and closed loop systems are developed and they are used for simulation studies. This converter is capable of producing ripple free DC output. Switching losses and switching stresses are reduced by using soft switching. This converter has advantages like high power density and low switching losses. Theoretical predictions are well supported by the simulation results.

  19. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  20. Light weight, high power, high voltage dc/dc converter technologies

    Science.gov (United States)

    Kraus, Robert; Myers, Ira; Baumann, Eric

    1990-01-01

    Power-conditioning weight reductions by orders of magnitude will be required to enable the megawatt-power-level space systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. An interagency program has been initiated to develop an 0.1-kg/kW dc/dc converter technology base for these future space applications. Three contractors are in the first phase of a competitive program to develop a megawatt dc/dc converter. Researchers at NASA Lewis Research Center are investigating innovative converter topology control. Three different converter subsystems based on square wave, resonant, and super-resonant topologies are being designed. The components required for the converter designs cover a wide array of technologies. Two different switches, one semiconductor and the other gas, are under development. Issues related to thermal management and material reliability for inductors, transformers, and capacitors are being investigated in order to maximize power density. A brief description of each of the concepts proposed to meet the goals of this program is presented.

  1. Planning and the Interagency Process: How can the United States Department of Defense and the Department of State Prepare for Future Joint Operations in a Time of Reduced Budgets?

    Science.gov (United States)

    2012-04-30

    Gabriel Marcella , ed., Affairs of State: The interagency and National Security (Washington, D.C., Strategic Studies Institute, 2008), 26. 6 James...8 Gabriel Marcella , 27. 9 Headquarters U.S. Marine Corps, Marine Corps Planning Process, MCWP 5-1 (Washington, D.C.: U.S. Marine Corps, August...17, 2012). Marcella , Gabriel, ed., Affairs of State: The Interagency and National Security (Washington, D.C., Strategic Studies Institute, 2008

  2. Corps G-2 Staff Competencies: A Desert Storm Case Study

    Science.gov (United States)

    2017-06-09

    Department of the Army, Army Doctrine Reference Publication (ADRP) 2-0, Intelligence (Washington, DC: Government Printing Office, August 2012), 3-2...Washington, DC: Government Printing Office, August 2012), 5-9. Intelligence Operations The second key corps G-2 intelligence meta-competency...Publication (ADRP) 2-0, Intelligence (Washington, DC: Government Printing Office, 2016), 4-2 to 4-9. Intelligence Analysis The final corps G-2

  3. Evolving Military Intelligence: The Effect of the Military Intelligence Service (MIS) and the Military Intelligence Organization (MIO) During the Korean and Vietnam Wars

    Science.gov (United States)

    2017-06-09

    Doctrine Publication (ADP) 2-0, Intelligence (Washington, DC: Government Printing Office, 2012), 1. 2 Scott D. Berrier, “ILE Branch Day” (Lecture, Command...Combat Intelligence (Washington, DC: Government Printing Office, 1951), 11-15. 6 groups of MI specialist teams within a larger tactical unit; allowing...Department of the Army, TOE 30- 115T, Combat Electronic Warfare Intelligence Battalion, Division (Washington, DC: Government Printing Office, 1976

  4. Digital peak current mode control with adaptive slope compensation for DC-DC converters

    DEFF Research Database (Denmark)

    Andersen, Karsten Holm; Nymand, Morten

    2017-01-01

    performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical......This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic...

  5. DC-Link Compensation Method for Slim DC Link Drives Fed by Soft Grid

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu

    2010-01-01

    Slim DC-link PWM (AC) drives for lowperformance applications are emerging on the market. Such drives equipped with a small DC-link capacitance exhibit instability tendencies, if installed on a soft line, giving a degraded performance. The total harmonic distortion (THD) and the partially weighted...... harmonic distortion (PWHD) of the line current are degraded, if resonance between the line impedance and the DC-link capacitance occurs. Likewise, the motor performance is affected negatively giving extra torque ripple, vibration and acoustic-noise emission. This paper proposes a novel DC-link compensation...

  6. High-power three-port three-phase bidirectional DC-DC converter

    NARCIS (Netherlands)

    Tao, H.; Duarte, J.L.; Hendrix, M.A.M.

    2007-01-01

    This paper proposes a three-port three-phase bidirectional dc-dc converter suitable for high-power applications. The converter combines a slow primary source and a fast storage to power a common load (e.g., an inverter). Since this type of system is gaining popularity in sustainable energy

  7. Book review: Pre-Clovis in the Americas: International Science Conference Proceedings

    Directory of Open Access Journals (Sweden)

    Jennifer Anderson

    2016-03-01

    Full Text Available This volume is comprised of papers presented at the “Pre-Clovis in the Americas” conference, held in 2012 at the Smithsonian Institution in Washington, D.C. The conference was convened to discuss the current state of research concerning Pre-Clovis occupations in the Americas. The goals of the conference were twofold: to gain a better understanding of Pre-Clovis artifact assemblages and to identify possible patterning in those assemblages that could point to the origin or origins of Pre-Clovis. The eleven papers in this volume present data from numerous Pre-Clovis sites across North and South America and offer unique suggestions for identifying new sites and assemblages that predate Clovis occupations in the Americas.

  8. Precharge strategies for isolated modular DC-DC converters under two different start-up conditions

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Li, Binbin

    2017-01-01

    The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value of capaci......The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value...... of capacitance in the IMDCC, proper precharge strategies before the start-up are significant for the safety and reliability of the whole system. This paper presents two closed-loop precharge control strategies to fully charge the sub-module (SM) capacitors of the IMDCC, considering two different start...

  9. 5 CFR Appendix C to Subpart B of... - Appropriated Fund Wage and Survey Areas

    Science.gov (United States)

    2010-01-01

    ... of Columbia, Washington, DC Survey Area District of Columbia: Washington, DC Maryland: Charles... Illinois: Cook Du Page Kane Lake McHenry Will Area of Application. Survey area plus: Illinois: Boone De...: Harrison Jennings Scott Washington Louisiana Lake Charles-Alexandria Survey Area Louisiana: Allen...

  10. Modeling and analysis of fractional order DC-DC converter.

    Science.gov (United States)

    Radwan, Ahmed G; Emira, Ahmed A; AbdelAty, Amr M; Azar, Ahmad Taher

    2017-07-11

    Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present. For example, the peak inductor current at steady state increases with decreasing the inductor order. Advanced Design Systems (ADS) circuit simulations are used to verify the derived formulas, where the fractional order inductor is simulated using Valsa Constant Phase Element (CPE) approximation and Generalized Impedance Converter (GIC). Different simulation results are introduced with good matching to the theoretical formulas for the three DC-DC converter topologies under different fractional orders. A comprehensive comparison with the recently published literature is presented to show the advantages and disadvantages of each approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Proceedings of the American Power Conference. Volume 58-I

    International Nuclear Information System (INIS)

    McBride, A.E.

    1996-01-01

    This is volume 58-I of the proceedings of the American Power Conference, 1996, Technology for Competition and Globalization. The topics of the papers include power plant DC issues; cost of environmental compliance; advanced coal systems -- environmental performance; technology for competition in dispersed generation; superconductivity technologies for electric utility applications; power generation trends and challenges in China; aging in nuclear power plants; innovative and competitive repowering options; structural examinations, modifications and repairs; electric load forecasting; distribution planning; EMF effects; fuzzy logic and neural networks for power plant applications; electrokinetic decontamination of soils; integrated gasification combined cycle; advances in fusion; cooling towers; relays; plant controls; flue gas desulfurization; waste product utilization; and improved technologies

  12. Magnetically coupled high-gain Y-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

  13. Proceedings of a Seminar on Water Quality R&D: Successful Bridging between Theory and Applications Held in New Orleans, Louisiana on 25-27 February 1986.

    Science.gov (United States)

    1986-06-01

    disposal, and sub- aqueous capping using cleaner sediment. Options for controlling confined disposal impacts include treatment, storage, and reuse . Evaluate...dominated first by Anabaena felisii and then replaced by Anabaena spiroides and Aphanizomenon flos- aguae (all filamentous, mat-forming blue-green...Protection Agency, Washington, DC, 1980. 247 Metcalf and Eddy, Inc., Wastewater Engineering Treatment/Disposal/ Reuse , McGraw Hill Book Company, New York

  14. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  15. Radiated electromagnetic emissions of DC-DC converters

    International Nuclear Information System (INIS)

    Feld, L; Jussen, R; Karpinski, W; Klein, K; Sammet, J; Wlochal, M

    2010-01-01

    For the CMS tracker at SLHC a new powering scheme is considered to be mandatory to allow the detector to provide at least the same performance as today at the LHC. The baseline solution of CMS foresees the use of DC-DC converters to provide larger currents with smaller losses. An important component of most converters are inductors which, however, tend to radiate the switching noise generated by the converter. The emissions of different inductors have been measured and simulated, the coil design has been optimized and noise susceptibility measurements, with present CMS hardware, have been performed. This article summarizes the results.

  16. Modeling, Analysis and Control of Different DC-DC Converter Topologies for Photo Voltaic Emulator

    Directory of Open Access Journals (Sweden)

    Mohammad Tauquir Iqbal

    2016-05-01

    Full Text Available This paper presents the modeling, analysis and control of different DC-DC converter topologies to emulate the photovoltaic (PV system. A PV emulator is basically a DC-DC converter having same electrical characteristics that of solar PV panel.  The emulator helps to achieve real characteristics of PV system in a better way in an environment where using actual PV systems can produce inconsistent results due to variation in weather conditions. The paper describes different types of DC-DC converters like buck, Resonant and Quasi Resonant Converter. The complete system is modelled in MATLAB® Simulink SimPowerSystem software package. The Simulation results obtained from the MATLAB® Simulink SimPowerSystem software package for different topologies under steady and dynamic conditions are analyzed and presented. An evaluation table is also presented at the end of the paper, presenting the effectiveness of each topology.

  17. As the Child Reads: The Treatment of Minorities in Textbooks and Other Teaching Materials. Conference Report, National NEA-PR&R Conference on Civil and Human Rights in Education (Washington, D. C., February 8-10, 1967).

    Science.gov (United States)

    Hart, Elinor, Ed.

    The conference on "The Treatment of Minorities in Textbooks and Other Teaching Materials" was held on February 8-10, 1967 in Washington, D.C. It was sponsored by the National Education Association and the Committee on Civil and Human Rights of Educators of the Commission on Professional Rights and Responsibilities. Attending the conference were…

  18. ACT-R/E: An Embodied Cognitive Architecture for Human-Robot Interaction

    Science.gov (United States)

    2013-01-01

    Threaded Cognition: An Integrated Theory of Concurrent Multitasking . Psychological Review, 115(1), 101–130, http://dx.doi.org/10.1037/0033-295X...Trafton, Naval Research Laboratory, Washington, DC, USA Email : greg.trafton@nrl.navy.mil Laura Hiatt, Naval Research Laboratory, Washington, DC, USA Email ...laura.hiatt@nrl.navy.mil Anthony Harrison, Naval Research Laboratory, Washington, DC, USA Email : anthony.harrison@nrl.navy.mil Frank Tamborello, Naval

  19. Homopolar dc motor and trapped flux brushless dc motor using high temperature superconductor materials

    Science.gov (United States)

    Crapo, Alan D.; Lloyd, Jerry D.

    1991-03-01

    Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.

  20. Differential Mode EMI Filter Design for Isolated DC-DC Boost Converter

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, Morten

    2014-01-01

    A Differential Mode EMI filter for a low input voltage high-current isolated dc-dc boost converter is designed and presented in this paper. The primary side Differential Mode noise voltage is low due to the high transformer turn ratio, however, the input current is very high and since the EMI limit...... also does not change for such converters, it requires greatly optimized design approach for the filter including the correct sizing of the filter components. A complete analytical filter design process is carried out such a way that the Differential Mode noise voltage source in the converter...... is identified first. The DM noise model is then established and based on the harmonic analysis of the noise source voltage waveform, the complete Differential Mode EMI filter, including the filter resonance damping branch, is designed for a 3kW isolated dc-dc boost converter. The noise model and its theoretical...

  1. Current Mode Control for LLC Series Resonant DC-to-DC Converters

    Directory of Open Access Journals (Sweden)

    Jinhaeng Jang

    2015-06-01

    Full Text Available Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a new current mode control scheme which could consistently provide good closed-loop performance for LLC resonant converters for the entire operational range. The proposed control scheme employs an additional feedback from the current of the resonant tank network to overcome the limitation of the existing voltage mode control. The superiority of the proposed current mode control over the conventional voltage mode control is verified using an experimental 150 W LLC series resonant DC-to-DC converter.

  2. Report of the workshop on rf heating in mirror systems

    International Nuclear Information System (INIS)

    Price, R.E.; Woo, J.T.

    1980-08-01

    This report is prepared from the proceedings of the Workshop on RF Heating in Magnetic Mirror Systems held at DOE Headquarters in Washington, DC, on March 10-12, 1980. The workshop was organized into four consecutive half-day sessions of prepared talks and one half-day discussion. The first session on tandem mirror concepts and program plans served to identify the opportunities for the application of rf power and the specific approaches that are being pursued. A summary of the ideas presented in this session is given. The following sessions of the workshop were devoted to an exposition of current theoretical and experimental knowledge on the interaction of rf power with magnetically confined, dense, high temperature plasmas at frequencies near the electron cyclotron resonance, lower hybrid resonance and ion cyclotron resonance (including magnetosonic) ranges. The conclusions from these proceedings are presented

  3. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-04-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  4. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-01-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  5. Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

    Science.gov (United States)

    Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

    2018-04-01

    Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

  6. Application of Distributed DC/DC Electronics in Photovoltaic Systems

    Science.gov (United States)

    Kabala, Michael

    In a typical residential, commercial or utility grade photovoltaic (PV) system, PV modules are connected in series and in parallel to form an array that is connected to a standard DC/AC inverter, which is then connected directly to the grid. This type of standard installation; however, does very little to maximize the energy output of the solar array if certain conditions exist. These conditions could include age, temperature, irradiance and other factors that can cause mismatch between PV modules in an array that severely cripple the output power of the system. Since PV modules are typically connected in series to form a string, the output of the entire string is limited by the efficiency of the weakest module. With PV module efficiencies already relatively low, it is critical to extract the maximum power out of each module in order to make solar energy an economically viable competitor to oil and gas. Module level DC/DC electronics with maximum power point (MPP) tracking solves this issue by decoupling each module from the string in order for the module to operate independently of the geometry and complexity of the surrounding system. This allows each PV module to work at its maximum power point by transferring the maximum power the module is able to deliver directly to the load by either boosting (stepping up) the voltage or bucking (stepping down) the voltage. The goal of this thesis is to discuss the development of a per-module DC/DC converter in order to maximize the energy output of a PV module and reduce the overall cost of the system by increasing the energy harvest.

  7. Quasiperiodicity and Torus Breakdown in a Power Electronic DC/DC Converter

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Soukhoterin, Evgeniy; Mosekilde, Erik

    2007-01-01

    This paper discusses the mechanisms of torus formation and torus destruction in a dc/dc converter with relay control and hysteresis. We establish a chart of the dynamical modes in the input voltage versus load resistance parameter plane. This chart displays several different torus bifurcations...

  8. DC Distribution Systems and Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez

    2017-01-01

    summarized. Due to its attractive characteristics in terms of compliance with modern generation, storage and electronic load technologies, high reliability and current carrying capacity, as well as simple control, DC systems are already an indispensable part of power systems. Moreover, the existing......A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been...... challenges such as protection issues will be effectively resolved in the near future due to fast progress of semiconductor technology which is a key enabler cheap and reliable future DC solid-state protection systems. Therefore, it is the view of the author that more and more DC systems will appear...

  9. Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Achim Kienle

    2009-03-01

    Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.

  10. Proceedings of the Molecular Electronic Devices Workshop Held at Washington, DC on 23-24 March 1981.

    Science.gov (United States)

    1981-10-22

    state in the gas phase. Deuteron quadrupole coupling constant (DQCC) studies by Jackman (4) gave the same result for the solution state of the molecule...3157 (1979). 4. L.M. Jackman , J.C. Trewella and R.C. Haddon, J. Am. Chem. Soc. 102, 2519 (1980). 5. C. Svensson, S.C. Abrahams, J.L. Bernstein and...Science, 175, 991-993 (1972). 7. L. Pauling, "The Nature of the Chemical Bond," Cornell Univ. Press, Ithaca, N. Y., 3rd Ed., 1960. 8. M. N. Hughes , "The

  11. Attitudes, perceptions, and behaviors toward HIV testing among African American and East African immigrant women in Washington, D.C.: Implications for targeted HIV testing promotion and communication strategies

    Science.gov (United States)

    De Jesus, Maria; Carrete, Claudia; Maine, Cathleen; Nalls, Patricia

    2015-01-01

    Objectives The objective of the study was to examine and compare the HIV testing attitudes, perceptions, and behaviors between African American and East African immigrant women in the Washington, D.C. Metropolitan area. Methods Adopting an inductive, qualitative methodological approach, we conducted a total of 40 in-depth, semi-structured interviews between October 2012 and March 2013. Qualitative thematic analysis was used to analyze the data. Results Overall, African American women held more favorable views toward HIV testing than East African immigrant women. Very few East African immigrant women sought HIV testing intentionally. The majority of East African participants were tested inadvertently, while others tested for immigration- or employment-related purposes. There were many barriers that impede women from seeking an HIV test including: negative assumptions (e.g., ‘Getting an HIV test implies that I am HIV positive’); negative emotions (e.g., ‘Fear of being diagnosed with HIV and what this will mean for me’); and potential negative reactions from partner or others (e.g., ‘Getting an HIV test can signal distrust, disrespect, or infidelity’). There were nuances in how each group articulated some of these barriers and East African women expressed unique concerns that originated from experiences in their home countries. Conclusions The study shed light into the complexity of factors that constrain women from presenting themselves voluntarily for an HIV test and highlighted the nuances between African American and East African perceptions. Implications of findings for effective targeted HIV screening promotion and communication strategies among these groups of women are discussed. PMID:25897146

  12. Single Event Burnout in DC-DC Converters for the LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Claudio H. Rivetta et al.

    2001-09-24

    High voltage transistors in DC-DC converters are prone to catastrophic Single Event Burnout in the LHC radiation environment. This paper presents a systematic methodology to analyze single event effects sensitivity in converters and proposes solutions based on de-rating input voltage and output current or voltage.

  13. Area-Efficiency Trade-Offs in Integrated Switched-Capacitor DC-DC Converters

    DEFF Research Database (Denmark)

    Spliid, Frederik Monrad; Larsen, Dennis Øland; Knott, Arnold

    2016-01-01

    This paper analyzes the relationship between efficiency and chip area in a fully integrated switched capacitor voltage divider dc-dc converter implemented in 180nm-technology and a 1/2 topology. A numerical algorithm for choosing the optimal sizes of individual components, in terms of power loss...

  14. Roles for National Guard Components: Current Thoughts and Future Possibilities

    Science.gov (United States)

    2000-04-01

    Gen Russell C. Davis, chief, National Guard Bureau, remarks at the National Chamber of Commerce , Washington, D.C., June 1999. 5 Moskos and Burk, 176...Lt Gen Russell C. Davis, chief, National Guard Bureau, remarks at the National Chamber of Commerce , Washington, D.C., June 9 1999. 5 National Guard...National Guard Bureau, remarks to the National Chamber of Commerce , Washington, D.C., June 1999, n.p. On-line. Internet, 27 February 2000, available at

  15. Device 2F112 (F-14A WST (Weapon System Trainers)) Instructor Console Review.

    Science.gov (United States)

    1983-12-01

    irdividuals adequately trained in the use of a particular trainer. ’S G. L. RICARD Scientific Officer 9., - 5 * NAVTRAEQUIPCEN 81-M-1121-1 TABLE OF...through verbal comunication with the instructors at the console. Several problems exist in the use of the flyout mismatch page. a. The automatic display...Washington, DC 20350 Washington, DC 20301 Chief of Naval Operations Commanding Officer OP-596C Air Force Office of Scientific Washington, DC 20350

  16. Egr2 induced during DC development acts as an intrinsic negative regulator of DC immunogenicity.

    Science.gov (United States)

    Miah, Mohammad Alam; Byeon, Se Eun; Ahmed, Md Selim; Yoon, Cheol-Hee; Ha, Sang-Jun; Bae, Yong-Soo

    2013-09-01

    Early growth response gene 2 (Egr2), which encodes a zinc finger transcription factor, is rapidly and transiently induced in various cell types independently of de novo protein synthesis. Although a role for Egr2 is well established in T-cell development, Egr2 expression and its biological function in dendritic cells (DCs) have not yet been described. Here, we demonstrate Egr2 expression during DC development, and its role in DC-mediated immune responses. Egr2 is expressed in the later stage of DC development from BM precursor cells. Even at steady state, Egr2 is highly expressed in mouse splenic DCs. Egr2-knockdown (Egr2-KD) DCs showed increased levels of major histocompatability complex (MHC) class I and II and co-stimulatory molecules, and enhanced antigen uptake and migratory capacities. Furthermore, Egr2-KD abolished SOCS1 expression and signal transducer and activator of transcription 5 (STAT5) activation during DC development, probably resulting in the enhancement of IL-12 expression and Th1 immunogenicity of a DC vaccine. DC-mediated cytotoxic T lymphocyte (CTL) activation and antitumor immunity were significantly enhanced by Egr2-KD, and impaired by Egr2 overexpression in antigen-pulsed DC vaccines. These data suggest that Egr2 acts as an intrinsic negative regulator of DC immunogenicity and can be an attractive molecular target for DC vaccine development. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. The 16th International Geological Congress, Washington, 1933

    Science.gov (United States)

    Nelson, C.M.

    2009-01-01

    In 1933, the International Geological Congress (IGC) returned to the United States of America (USA) for its sixteenth meeting, forty-two years after the 5th IGC convened in Washington. The Geological Society of America and the U.S. Geological Survey (USGS) supplied the major part of the required extra-registration funding after the effects of the Great Depression influenced the 72th U.S. Congress not to do so. A reported 1, 182 persons or organizations, representing fifty-four countries, registered for the 16 th IGC and thirty-four countries sent 141 official delegates. Of the total number of registrants, 665 actually attended the meeting; 500 came from the USA; and fifteen had participated in the 5th IGC. The 16 th Meeting convened in the U.S. Chamber of Commerce Building from 22 to 29 July. The eighteen half-day scientific sections-orogenesis (four), major divisions of the Paleozoic (three), miscellaneous (three), batholiths and related intrusives (two), arid-region geomorphic processes and products (one), fossil man and contemporary faunas (one), geology of copper and other ore deposits (one), geology of petroleum (one), measuring geologic time (one), and zonal relations of metalliferous deposits (one)-included 166 papers, of which fifty (including several of the key contributions) appeared only by title. The Geological Society of Washington, the National Academy of Sciences, and the U.S. Bureau of Mines hosted or contributed to evening presentations or receptions. Twenty-eight of the 16th IGC's thirty new guidebooks and one new USGS Bulletin aided eight pre-meeting, seven during-meeting, and four post-meeting field trips of local, regional, or national scope. The remaining two new guidebooks outlined the USA's structural geology and its stratigraphic nomenclature. The 16th IGC published a two-volume monograph on the world's copper resources (1935) and a two-volume report of its proceedings (1936).

  18. 77 FR 46185 - United States v. United Technologies Corporation and Goodrich Corporation; Proposed Final...

    Science.gov (United States)

    2012-08-02

    ...''), but smaller aircraft can use either AC or direct current (``DC''). AC generators can produce variable... Justice, Antitrust Division, Antitrust Documents Group, 450 Fifth Street NW., Suite 1010, Washington, DC... Street NW., Suite 8700, Washington, DC 20530 (telephone: (202) 307-0924). Patricia A. Brink, Director of...

  19. Impact of DC link control strategies on the power-flow convergence of integrated AC–DC systems

    Directory of Open Access Journals (Sweden)

    Shagufta Khan

    2016-03-01

    Full Text Available For the power-flow solution of integrated AC–DC systems, five quantities are required to be solved per converter, against three independent equations available. These three equations consist of two basic converter equations and one DC network equation, corresponding to each converter. Thus, for solution, two additional equations are required. These two equations are derived from the control specifications adopted for the DC link. Depending on the application, several combinations of valid control specifications are possible. A set of valid control specifications constitutes a control strategy. It is observed that the control strategy adopted for the DC link strongly affects the power-flow convergence of integrated AC–DC systems. This paper investigates how different control strategies affect the power flow convergence of integrated AC–DC systems. Sequential method is used to solve the DC variables in the Newton Raphson (NR power flow model. Seven typical control strategies have been taken into consideration. This is validated by numerous case studies carried out with multiple DC links incorporated in the IEEE 118-bus and 300-bus test systems.

  20. Proceedings of the 5th symposium on accelerator science and technology

    International Nuclear Information System (INIS)

    1985-01-01

    This proceedings are included 157 papers to submitting 5th Symposium on Accelerator Science and Technology. The papers are presented under the following main topics: a) invited talk (3 papers), b) status of accelerator construction and operation (12 papers), c) ion source and DC accelerator(7 papers), d) linac (16 papers), e) RF acceleration system (15 papers), f) beam monitor and beam handling (20 papers), g) magnet and power supply (13 papers), h) vacuum (12 papers), i) beam dynamics (20 papers), j) accelerator operation and control (22 papers), k) radiation and safety (8 papers), 1) future project (8 papers) and so on. (J.P.N.)

  1. 75 FR 47820 - Generic Drug User Fee; Public Meeting; Request for Comments

    Science.gov (United States)

    2010-08-09

    ... Hilton Washington DC/ Rockville and Executive Meeting Center, 1750 Rockville Pike, Rockville, MD 20852... 17, 2010, at the Hilton Washington DC/Rockville and Executive Meeting Center, see Location). In...

  2. Investigation of DC-DC Boost Converter for Reliability of Operational Planning

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Ashouri, Mani; Silva, Filipe Miguel Faria da

    2018-01-01

    of the interests related to reliability is the power semiconductor switches, which are the most vulnerable elements. The failure of one-power switches can reduce the system reliability. Interleaved technique for DC-DC converters is a redundant strategy to improve the reliability, but at the cost of increasing...

  3. Comparison of solar panel cooling system by using dc brushless fan and dc water

    International Nuclear Information System (INIS)

    Irwan, Y M; Leow, W Z; Irwanto, M; M, Fareq; Hassan, S I S; Amelia, A R; Safwati, I

    2015-01-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer. (paper)

  4. Willingness of community-recruited men who have sex with men in Washington, DC to use long-acting injectable HIV pre-exposure prophylaxis.

    Directory of Open Access Journals (Sweden)

    Matthew E Levy

    Full Text Available Clinical trials are currently investigating the safety and efficacy of long-acting injectable (LAI agents as HIV pre-exposure prophylaxis (PrEP. Using National HIV Behavioral Surveillance data, we assessed the self-reported willingness of men who have sex with men (MSM to use LAI PrEP and their preference for LAI versus daily oral PrEP.In 2014, venue-based sampling was used to recruit MSM aged ≥18 years in Washington, DC. Participants completed an interviewer-administered survey followed by voluntary HIV testing. This analysis included MSM who self-reported negative/unknown HIV status at study entry. Correlates of being "very likely" to use LAI PrEP and preferring it to daily oral PrEP were identified using multivariable logistic regression.Of 314 participants who self-reported negative/unknown HIV status, 50% were <30 years old, 41% were non-Hispanic Black, 37% were non-Hispanic White, and 14% were Hispanic. If LAI PrEP were offered for free or covered by health insurance, 62% were very likely, 25% were somewhat likely, and 12% were unlikely to use it. Regarding preferred PrEP modality, 67% chose LAI PrEP, 24% chose oral PrEP, and 9% chose neither. Correlates of being very likely versus somewhat likely/unlikely to use LAI PrEP included age <30 years (aOR 1.64; 95% CI 1.00-2.68, reporting ≥6 (vs. 1 sex partners in the last year (aOR 2.60; 95% CI 1.22-5.53, previous oral PrEP use (aOR 3.67; 95% CI 1.20-11.24, and being newly identified as HIV-infected during study testing (aOR 4.83; 95% CI 1.03-22.67. Black (vs. White men (aOR 0.48; 95% CI 0.24-0.96 and men with an income of <$20,000 (vs. ≥$75,000; aOR 0.37; 95% CI 0.15-0.93 were less likely to prefer LAI to oral PrEP.If LAI PrEP were found to be efficacious, its addition to the HIV prevention toolkit could facilitate more complete PrEP coverage among MSM at risk for HIV.

  5. 75 FR 47199 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-10 Series Airplanes, DC-9-30...

    Science.gov (United States)

    2010-08-05

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-10 Series Airplanes, DC-9-30 Series... existing airworthiness directive (AD), which applies to all McDonnell Douglas Model DC-9-10 series..., 2010). That AD applies to all McDonnell Douglas Corporation Model DC-9-10 series airplanes, DC-9-30...

  6. Attitudes, perceptions and behaviours towards HIV testing among African-American and East African immigrant women in Washington, DC: implications for targeted HIV testing promotion and communication strategies.

    Science.gov (United States)

    De Jesus, Maria; Carrete, Claudia; Maine, Cathleen; Nalls, Patricia

    2015-12-01

    The objective of the study was to examine and compare the HIV testing attitudes, perceptions and behaviours between African-American and East African immigrant women in the Washington, DC metropolitan area. Adopting an inductive, qualitative methodological approach, we conducted a total of 40 in-depth, semistructured interviews between October 2012 and March 2013. Qualitative thematic analysis was used to analyse the data. Overall, African-American women held more favourable views towards HIV testing than East African immigrant women. Very few East African immigrant women sought HIV testing intentionally. The majority of East African participants were tested inadvertently, while others tested for immigration-related or employment-related purposes. There were many barriers that impede women from seeking an HIV test including negative assumptions (eg, "Getting an HIV test implies that I am HIV positive"), negative emotions (eg, "Fear of being diagnosed with HIV and what this will mean for me") and potential negative reactions from partner or others (eg, "Getting an HIV test can signal distrust, disrespect, or infidelity"). There were nuances in how each group articulated some of these barriers and East African women expressed unique concerns that originated from experiences in their home countries. The study shed light into the complexity of factors that constrain women from presenting themselves voluntarily for an HIV test and highlighted the nuances between African-American and East African perceptions. Implications of findings for effective targeted HIV screening promotion and communication strategies among these groups of women are discussed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2017-01-01

    A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...

  8. Characterization of diode valve in medium voltage dc/dc converter for wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne

    2016-01-01

    This paper proposes a methodology for characterization of medium voltage (MV), medium frequency (MF) rectifier diode valve. The intended application is for 10MW dc/dc converters used in DC offshore wind turbines. Sensitivity to semiconductor component parameter variation, snubber component tolera...... tolerance, influence of temperature and stray capacitance are analyzed. It is concluded that the largest impact on sensitivity is given by reverse recovery charge variation and differences of temperature between adjacent devices....

  9. Operation and control of a DC-grid offshore wind farm under DC transmission system faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    . Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

  10. Open- and Short-Circuit Fault Identification for a Boost dc/dc Converter in PV MPPT Systems

    Directory of Open Access Journals (Sweden)

    Diego R. Espinoza Trejo

    2018-03-01

    Full Text Available This paper proposes a fault identification system for short and open-circuit switch faults (SOCSF for a dc/dc converter acting as a Maximum Power Point Tracker (MPPT in Photovoltaic (PV systems. A closed-loop operation is assumed for the boost dc/dc converter. A linearizing control plus a Proportional-Derivative (PD controller is suggested for PV voltage regulation at the maximum power point (MPP. In this study, the SOCSF are modeled by using an additive fault representation and the fault identification (FI system is synthesized departing from a Luenberger observer. Hence, an FI signal is obtained, which is insensitive to irradiance and load current changes, but affected by the SOCSF. For FI purposes, only the sensors used in the control system are needed. Finally, an experimental evaluation is presented by using a solar array simulator dc power supply and a boost dc/dc converter of 175 W in order to validate the ideas this study exposes.

  11. Research on Two-channel Interleaved Two-stage Paralleled Buck DC-DC Converter for Plasma Cutting Power Supply

    DEFF Research Database (Denmark)

    Yang, Xi-jun; Qu, Hao; Yao, Chen

    2014-01-01

    As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...

  12. Pulsed-DC selfsputtering of copper

    International Nuclear Information System (INIS)

    Wiatrowski, A; Posadowski, W M; Radzimski, Z J

    2008-01-01

    At standard magnetron sputtering conditions (argon pressure ∼0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (∼550W/cm 2 ). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%

  13. Pulsed-DC selfsputtering of copper

    Science.gov (United States)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-03-01

    At standard magnetron sputtering conditions (argon pressure ~0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (~550W/cm2). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%.

  14. DC injection into low voltage AC networks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.

  15. 78 FR 13358 - National Institute of Mental Health; Notice of Closed Meetings

    Science.gov (United States)

    2013-02-27

    ... Washington, DC, 2401 M Street, NW., Washington, DC 20037. Contact Person: Rebecca C Steiner, Ph.D..., (Telephone Conference Call). Contact Person: Rebecca C Steiner, Ph.D., Scientific Review Officer, Division of...

  16. Transition towards DC micro grids: From an AC to a hybrid AC and DC energy infrastructure

    Directory of Open Access Journals (Sweden)

    Evi Ploumpidou

    2017-12-01

    Full Text Available Our electricity is predominantly powered by alternating current (AC, ever since the War of Currents ended in the favor of Nicola Tesla at the end of the 19th century. However, lots of the appliances we use, such as electronics and lights with light-emitting diode (LED technology, work internally on direct current (DC and it is projected that the number of these appliances will increase in the near future. Another contributor to the increase in DC consumption is the ongoing electrification of mobility (Electric Vehicles (EVs. At the same time, photovoltaics (PV generate DC voltages, while the most common storage technologies also use DC. In order to integrate all these appliances and technologies to the existing AC grid, there is a need for converters which introduce power losses. By distributing DC power to DC devices instead of converting it to AC first, it is possible to avoid substantial energy losses that occur every time electricity is converted. This situation initiated the concept for the implementation of the DC-Flexhouse project. A prototype DC installation will be developed and tested in one of the buildings of the developing living lab area called the District of Tomorrow (De Wijk van Morgen which is located in Heerlen, the Netherlands. A neighborhood cooperative (Vrieheide cooperatie is also part of the consortium in order to address the aspect of social acceptance. Although DC seems to be a promising solution for a more sustainable energy system, the business case is still debatable due to both technology- and market-related challenges. The current energy infrastructure is predominantly based on AC, manufacturers produce devices based on AC standards and people are using many AC products across a long life span. This Smart Energy Buildings & Cities (SEB&C PDEng project is a contribution to the DC-Flexhouse project. The aim is to analyze the challenges in the transition to DC micro grids, assess the market potential of DC

  17. Socrates in Washington, D.C.

    Science.gov (United States)

    2008-08-01

    neoclassical architecture , his flowing robes practically blended in. At any rate, he didn’t get more than a passing glance from the pedes- trians and...American cinema and TV. “And I do believe it was this same Hawkeye who said, ‘If we don’t go crazy once in a while, we’ll all go crazy.’” We settled down

  18. Superconductivity in Washington, D.C

    International Nuclear Information System (INIS)

    Ritter, D.

    1988-01-01

    The author provides insights into the federal government's activity in superconductors. He says the President's most important legislative proposal is a change in anti-trust laws to allow businesses to cooperate on joint production ventures. The President has also directed the Department of Energy, the Department of Commerce, the National Aeronautics and Space Administration, the National Science Foundation, and the Department of Defense to establish Superconductivity Research Centers to conduct research and disseminate information. The author says he thinks it is worthwhile to pursue the President's proposal for cooperation with Japan in superconductivity research and development. The author explains why he supports this and other key legislation related to superconductivity. He says if the United States does not do all that it can, as fast as it can, both domestically and internationally, the U.S. could lose the cutting edge of technological and commercial leadership in the latter 20th century and the 21st century. This is what superconductivity represents

  19. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  20. High voltage dc cables

    Energy Technology Data Exchange (ETDEWEB)

    Bjustrom, B

    1965-12-01

    How stress distribution in dc cables varies with temperature and stress level, influence of polarity reversals and space charges, and different types of overvoltage to which dc cable may be subjected are discussed. Design problems, especially as related to corrosion protection and to mechanical stress caused by wire armoring during manufacturing and laying, accessories and work done on test methods, and the possibility of designing 400 to 600 kV dc cables for transmitting 2000 to 4000 MW are described.

  1. Comparative evaluation of bidirectional dual active bridge DC-DC converter variants

    NARCIS (Netherlands)

    Sfakianakis, G.; Everts, J.; Huisman, H.; Lomonova, E.A.

    2016-01-01

    For the realization of DC-DC converters in automotive industry, the Dual Active Bridge (DAB) converter seems to be a promising choice because of its soft-switching and high-power-density capability. Contrary to the traditional 3 level - 3 level (3-3L) DAB, a 3 level - 5 level (3-5L) DAB can operate

  2. Improvement of burst-mode control of piezoelectric transformer based DC/DC converter

    International Nuclear Information System (INIS)

    Vasic, Dejan; Liu, Yuan-Ping; Costa, François; Schwander, Denis; Wu, Wen-Jong

    2013-01-01

    Burst-mode operation is adopted sometimes in piezoelectric transformer based converters for two major purposes: (1) to achieve voltage regulation in DC/DC converters and (2) to achieve dimming control in backlight inverters. Burst-mode control enables the converter to operate at a constant switching frequency as well as to maintain good efficiency at light load conditions. However, in practice, the piezoelectric transformer cannot instantly stop vibrating in the burst-mode due to its high quality factor. The delay in the output voltage change resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit. The proposed control strategy is verified by experiments in a step-down 9 W DC/DC converter. (paper)

  3. 78 FR 33691 - Distribution of Source Material to Exempt Persons and to General Licensees and Revision of...

    Science.gov (United States)

    2013-06-05

    ..., Washington, DC 20555-0001, telephone: 301-415- 8106, email: [email protected] or Tomas Herrera, Office of..., Washington, DC 20555-0001, telephone: 301-415- 7138, email: Tomas.Herrera@nrc.gov . SUPPLEMENTARY INFORMATION...

  4. Modular Power System Configured with Standard Product Hybrid DC-DC Converters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — VPT proposes an innovative concept whereby complex NASA space power electronic systems can be configured using a small number of qualified hybrid DC-DC converter and...

  5. DIAGNOSTIC/PROGNOSTIC EXPERIMENTS FOR CAPACITOR DEGRADATION AND HEALTH MONITORING IN DC-DC CONVERTERS

    Data.gov (United States)

    National Aeronautics and Space Administration — Studying and analyzing the ageing mechanisms of electronic components avionics in systems such as the GPS and INAV are of critical importance. In DC-DC power...

  6. Simulating and Testing a DC-DC Half-Bridge SLR Converter

    Science.gov (United States)

    2013-06-01

    future pulse power demands with ship power, a large bank of capacitors or similar rapid discharge source is required. If capacitors are charged...Single Pulsed Avalanche Energy (j) I" Avalanche Current (i) E,, Repetilive Avalanche Energy (i) dv/dt Peak Diode Recovery dv/dt ® Po Total Power...SLR), battery charging, DC-DC, pulse power, power electronics, SLR converter 15. NUMBER OF PAGES 119 16. PRICE CODE 17. SECURITY CLASSIFICATION

  7. Efficient Visible Light Communication Transmitters Based on Switching-Mode dc-dc Converters

    Science.gov (United States)

    2018-01-01

    Visible light communication (VLC) based on solid-state lighting (SSL) is a promising option either to supplement or to substitute existing radio frequency (RF) wireless communication in indoor environments. VLC systems take advantage of the fast modulation of the visible light that light emitting diodes (LEDs) enable. The switching-mode dc-to-dc converter (SMCdc-dc) must be the cornerstone of the LED driver of VLC transmitters in order to incorporate the communication functionality into LED lighting, keeping high power efficiency. However, the new requirements related to the communication, especially the high bandwidth that the LED driver must achieve, converts the design of the SMCdc-dc into a very challenging task. In this work, three different methods for achieving such a high bandwidth with an SMCdc-dc are presented: increasing the order of the SMCdc-dc output filter, increasing the number of voltage inputs, and increasing the number of phases. These three strategies are combinable and the optimum design depends on the particular VLC application, which determines the requirements of the VLC transmitter. As an example, an experimental VLC transmitter based on a two-phase buck converter with a fourth-order output filter will demonstrate that a bandwidth of several hundred kilohertz (kHz) can be achieved with output power levels close to 10 W and power efficiencies between 85% and 90%. In conclusion, the design strategy presented allows us to incorporate VLC into SSL, achieving high bit rates without damaging the power efficiency of LED lighting. PMID:29642455

  8. Proceedings of the International Wire and Cable Symposium (32nd) Held at Cherry Hill, New Jersey on November 15, 16 and 17, 1983.

    Science.gov (United States)

    1983-11-17

    34 tion principle allows the fabrication of /6/ Zielinski , H.G., S. Mlinger, Fibre long cable lengths adopted to the expec- Optical Coupling Techniques and... Dave graduated in 1949 from Georgetown University, Washington, D.C., with BS in Chemistry. He performed graduate work at Northwestern University in...Marketing prior to serving in U.S. Army, Chemical Corps. Dave joined Du Pont in 1954 after leaving the Army. His present assignment as Senior Development

  9. DC-Voltage Fluctuation Elimination Through a DC-Capacitor Current Control for DFIG Converters Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Changjin; Xu, Dehong; Zhu, Nan

    2013-01-01

    Unbalanced grid voltage causes a large second-order harmonic current in the dc-link capacitors as well as dc-voltage fluctuation, which potentially will degrade the lifespan and reliability of the capacitors in voltage source converters. This paper proposes a novel dc-capacitor current control...... method for a grid-side converter (GSC) to eliminate the negative impact of unbalanced grid voltage on the dc-capacitors. In this method, a dc-capacitor current control loop, where a negative-sequence resonant controller is used to increase the loop gain, is added to the conventional GSC current control...... loop. The rejection capability to the unbalanced grid voltage and the stability of the proposed control system are discussed. The second-order harmonic current in the dc capacitor as well as dc-voltage fluctuation is very well eliminated. Hence, the dc capacitors will be more reliable under unbalanced...

  10. 76 FR 32359 - Sunshine Act Meeting

    Science.gov (United States)

    2011-06-06

    ... Washington, DC, City Center Hotel, 1400 M Street NW., Washington, DC 20005, Phone number (202) 429-1700... EAC's program activities and budget. The Board will receive updates on the Voting System Testing and...

  11. AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-12-01

    Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

  12. First Implementation of a Two-Stage DC-DC Conversion Powering Scheme for the CMS Phase-2 Outer Tracker

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Pauls, Alexander Josef; Preuten, Marius; Rauch, Max Philip; Wangelik, Frederik; Wlochal, Michael

    2017-01-01

    The 2S silicon strip modules for the CMS Phase-2 tracker upgrade will require two operating voltages. These will be provided via a two-step DC-DC conversion powering scheme, in which one DC-DC converter delivers 2.5\\,V while the second DC-DC converter receives 2.5\\,V at its input and converts it to 1.2\\,V. The DC-DC converters will be mounted on a flex PCB, the service hybrid, together with an opto-electrical converter module (VTRx+) and a serializer (LP-GBT). The service hybrid will be mounted directly on the 2S module. A prototype service hybrid has been developed and its performance has been evaluated, including radiative and conductive noise emissions, and efficiency. In addition system tests with a prototype module have been performed. In this report the service hybrid will be described and the test results will be summarized.

  13. A suitable model plant for control of the set fuel cell-DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)

    2008-04-15

    In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)

  14. 78 FR 66032 - Center for Scientific Review; Notice of Closed Meetings

    Science.gov (United States)

    2013-11-04

    ... applications. Place: The Ritz-Carlton, 1150 22nd Street NW., Washington, DC 20037. Contact Person: Eduardo A.... Place: The Ritz-Carlton, 1150 22nd Street NW., Washington, DC 20037. Contact Person: Eduardo A Montalvo...

  15. 78 FR 3012 - National Institute of Diabetes and Digestive and Kidney Diseases; Notice of Closed Meetings

    Science.gov (United States)

    2013-01-15

    ... applications. Place: Ritz Carlton Hotel, 1150 22nd Street NW., Washington, DC 20037. Contact Person: Thomas A... applications. Place: Ritz Carlton Hotel, 1150 22nd Street NW., Washington, DC 20037. Contact Person: Thomas A...

  16. Research of digital controlled DC/DC converter based on STC12C5410AD

    Science.gov (United States)

    Chen, Dan-Jiang; Jin, Xin; Xiao, Zhi-Hong

    2010-02-01

    In order to study application of digital control technology on DC/DC converter, principle of increment mode PID control algorithm was analyzed in the paper. Then, a SCM named STC12C5410AD was introduced with its internal resources and characteristics. The PID control algorithm can be implemented easily based on it. The output of PID control was used to change the value of a variable that is 255 times than duty cycle, and this reduced the error of calculation. The valid of the presented algorithm was verified by an experiment for a BUCK DC/DC converter. The experimental results indicated that output voltage of the BUCK converter is stable with low ripple.

  17. On-grid and Off-grid Operation of Multi-Input Single-Output DC/DC Converter based Fuel Cell Generation System

    Directory of Open Access Journals (Sweden)

    Noroozian

    2009-06-01

    Full Text Available This paper presents the modeling and simulation of a proton exchange membrane fuel cell (PEMFC generation system for off-grid and on-grid operation and configuration. A fuel cell DG system consists of a fuel cell power plant, a DC/DC converter and a DC/AC inverter. The dynamic model for fuel cell array and its power electronic interfacing are presented also a multi-input single output (MISO DC/DC converter and its control scheme is proposed and analyzed. This DC/DC converter is capable of interfacing fuel cell arrays to the DC/AC inverter. Also the mathematical model of the inverter is obtained by using average technique. Then the novel control strategy of DC/AC inverter for different operating conditions is demonstrated. The simulation results show the effectiveness of the suggested control systems under both on-grid and off-grid operation modes.

  18. RF-superimposed DC and pulsed DC sputtering for deposition of transparent conductive oxides

    International Nuclear Information System (INIS)

    Stowell, Michael; Mueller, Joachim; Ruske, Manfred; Lutz, Mark; Linz, Thomas

    2007-01-01

    Transparent conductive oxide films are widely used materials for electronic applications such as flat panel displays and solar cells. The superposition of DC and pulsed DC power by a certain fraction of RF power was applied to deposit indium tin oxide films. This technique allows an additional tuning of different parameters relevant to film growth, and yields high quality films even under kinetically limited conditions. A long-term stable RF/DC process could be realized by using different combinations of standard power supply components, which includes a fully reliable arc handling system for both the RF and DC generators. The effectiveness of the arc handling system is illustrated by the current and voltage behavior recorded for actual arcing events. The resistivity of indium tin oxide films is strongly influenced by the respective sputtering mode. The best resistivity values of 145-148 μΩ cm were obtained by RF-superimposed pulsed DC sputtering at a pulse frequency between 100 and 200 kHz and a substrate temperature as low as 140 deg. C. In addition, the films were extremely smooth with a surface roughness of 1-2.5 nm

  19. The application of standardized control and interface circuits to three dc to dc power converters.

    Science.gov (United States)

    Yu, Y.; Biess, J. J.; Schoenfeld, A. D.; Lalli, V. R.

    1973-01-01

    Standardized control and interface circuits were applied to the three most commonly used dc to dc converters: the buck-boost converter, the series-switching buck regulator, and the pulse-modulated parallel inverter. The two-loop ASDTIC regulation control concept was implemented by using a common analog control signal processor and a novel digital control signal processor. This resulted in control circuit standardization and superior static and dynamic performance of the three dc-to-dc converters. Power components stress control, through active peak current limiting and recovery of switching losses, was applied to enhance reliability and converter efficiency.

  20. Design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters

    CERN Document Server

    Cravero, Jean-Marc

    2013-01-01

    This technical report presents the design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters. The power stage is based on a half bridge series resonant converter in Discontinuous Conduction Mode (DCM). This simple and robust topology allows obtaining a current source behavior with a low switching losses power stage. The associated control stage is implemented using a commercial controller which has differenti nternal circuits that allows a high integration of the converter control system. The report presents the design and tuning criteria for the DC-DC converter, including the power stage and the control system.

  1. Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how......Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...... the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes...

  2. Design and Implementation of Digital Current Mode Controller for DC-DC Converters

    DEFF Research Database (Denmark)

    Taeed, Fazel

    to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog...

  3. Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

    International Nuclear Information System (INIS)

    Adib, Ehsan; Farzanehfard, Hosein

    2009-01-01

    In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis.

  4. Design and modelling of high gain DC-DC converters for fuel cell hybrid electric vehicles

    Science.gov (United States)

    Elangovan, D.; Karthigeyan, V.; Subhanu, B.; Ashwin, M.; Arunkumar, G.

    2017-11-01

    Transportation (Diesel and petrol internal combustion engine vehicles) approximately contributes to 25.5% of total CO2 emission. Thus diesel and petrol engine vehicles are the most dominant contributors of CO2 emission which leads global warming which causes climate change. The problem of CO2 emission and global warming can be reduced by focusing on renewable energy vehicles. Out of the available renewable energy sources fuel cell is the only source which has reasonable efficiency and can be used in vehicles. But the main disadvantage of fuel cell is its slow response time. So energy storage systems like batteries and super capacitors are used in parallel with the fuel cell. Fuel cell is used during steady state vehicle operation while during transient conditions like starting, acceleration and braking batteries and super capacitors can supply or absorb energy. In this paper a unidirectional fuel cell DC-DC converter and bidirectional energy storage system DC-DC converter is proposed, which can interface dc sources at different voltage levels to the dc bus and also it can independently control the power flow from each energy source to the dc bus and vice versa. The proposed converters are designed and simulated using PSIM version 9.1.1 and gate pulse pattern, input and output voltage waveforms of the converters for steady state operation are studied.

  5. Modelling and Control Design of a Dual Buck-Boost AC/DC Converter Used in the DC Nano-Grid

    DEFF Research Database (Denmark)

    Wu, Weimin; Liu, Yuan; Wang, Houqing

    2016-01-01

    Due to widely used DC characterized loads and more distributed power generation sources, the DC Nano-grid becomes more and more popular and seen as an alternative to the AC-grid in future. For the safety considerations, the DC Nano-grid should provide reliable grounding for the residential loads...... like the low voltage AC power system. In this paper, a dual Buck-Boost AC/DC converter for use in the united grounding configuration based DC Nano-grid with three terminal outputs is proposed. It will be much easy to construct an efficient DC Nano-grid based on the existing low AC power system by using...

  6. Magnetically integrated high step-up resonant DC-DC converter for distributed photovoltaic systems

    DEFF Research Database (Denmark)

    Vinnikov, Dmitri; Chub, Andrii; Liivik, Elizaveta

    2017-01-01

    In this paper magnetically integrated resonant single-switch quasi-Z-source DC-DC converter is evaluated as a candidate topology for the low-cost photovoltaic microconverter. The derivation of the topology and its basic operation principle are explained. Generalized design guidelines...

  7. 77 FR 44603 - Petition for Waiver of LG Electronics, Inc. From the Department of Energy Residential...

    Science.gov (United States)

    2012-07-30

    ....com . Of counsel: John A. Hodges, Wiley Rein LLP, 1776 K Street NW., Washington, DC 20006, Phone: 202....com . Of counsel: John A. Hodges, Wiley Rein LLP, 1776 K Street NW., Washington, DC 20006, Phone: 202...

  8. Implementation of a Multimodal Mobile System for Point-of-Sale Surveillance: Lessons Learned From Case Studies in Washington, DC, and New York City.

    Science.gov (United States)

    Cantrell, Jennifer; Ganz, Ollie; Ilakkuvan, Vinu; Tacelosky, Michael; Kreslake, Jennifer; Moon-Howard, Joyce; Aidala, Angela; Vallone, Donna; Anesetti-Rothermel, Andrew; Kirchner, Thomas R

    2015-01-01

    In tobacco control and other fields, point-of-sale surveillance of the retail environment is critical for understanding industry marketing of products and informing public health practice. Innovations in mobile technology can improve existing, paper-based surveillance methods, yet few studies describe in detail how to operationalize the use of technology in public health surveillance. The aims of this paper are to share implementation strategies and lessons learned from 2 tobacco, point-of-sale surveillance projects to inform and prepare public health researchers and practitioners to implement new mobile technologies in retail point-of-sale surveillance systems. From 2011 to 2013, 2 point-of-sale surveillance pilot projects were conducted in Washington, DC, and New York, New York, to capture information about the tobacco retail environment and test the feasibility of a multimodal mobile data collection system, which included capabilities for audio or video recording data, electronic photographs, electronic location data, and a centralized back-end server and dashboard. We established a preimplementation field testing process for both projects, which involved a series of rapid and iterative tests to inform decisions and establish protocols around key components of the project. Important components of field testing included choosing a mobile phone that met project criteria, establishing an efficient workflow and accessible user interfaces for each component of the system, training and providing technical support to fieldworkers, and developing processes to integrate data from multiple sources into back-end systems that can be utilized in real-time. A well-planned implementation process is critical for successful use and performance of multimodal mobile surveillance systems. Guidelines for implementation include (1) the need to establish and allow time for an iterative testing framework for resolving technical and logistical challenges; (2) developing a streamlined

  9. Implementation of a Multimodal Mobile System for Point-of-Sale Surveillance: Lessons Learned From Case Studies in Washington, DC, and New York City

    Science.gov (United States)

    Ganz, Ollie; Ilakkuvan, Vinu; Tacelosky, Michael; Kreslake, Jennifer; Moon-Howard, Joyce; Aidala, Angela; Vallone, Donna; Anesetti-Rothermel, Andrew; Kirchner, Thomas R

    2015-01-01

    Background In tobacco control and other fields, point-of-sale surveillance of the retail environment is critical for understanding industry marketing of products and informing public health practice. Innovations in mobile technology can improve existing, paper-based surveillance methods, yet few studies describe in detail how to operationalize the use of technology in public health surveillance. Objective The aims of this paper are to share implementation strategies and lessons learned from 2 tobacco, point-of-sale surveillance projects to inform and prepare public health researchers and practitioners to implement new mobile technologies in retail point-of-sale surveillance systems. Methods From 2011 to 2013, 2 point-of-sale surveillance pilot projects were conducted in Washington, DC, and New York, New York, to capture information about the tobacco retail environment and test the feasibility of a multimodal mobile data collection system, which included capabilities for audio or video recording data, electronic photographs, electronic location data, and a centralized back-end server and dashboard. We established a preimplementation field testing process for both projects, which involved a series of rapid and iterative tests to inform decisions and establish protocols around key components of the project. Results Important components of field testing included choosing a mobile phone that met project criteria, establishing an efficient workflow and accessible user interfaces for each component of the system, training and providing technical support to fieldworkers, and developing processes to integrate data from multiple sources into back-end systems that can be utilized in real-time. Conclusions A well-planned implementation process is critical for successful use and performance of multimodal mobile surveillance systems. Guidelines for implementation include (1) the need to establish and allow time for an iterative testing framework for resolving technical and

  10. Washington State Biofuels Industry Development

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, Richard [Univ. of Washington, Seattle, WA (United States)

    2017-04-09

    The funding from this research grant enabled us to design, renovate, and equip laboratories to support University of Washington biofuels research program. The research that is being done with the equipment from this grant will facilitate the establishment of a biofuels industry in the Pacific Northwest and enable the University of Washington to launch a substantial biofuels and bio-based product research program.

  11. DC-DC Type High-Frequency Link DC for Improved Power Quality of Cascaded Multilevel Inverter

    Science.gov (United States)

    Sadikin, Muhammad; Senjyu, Tomonobu; Yona, Atsushi

    2013-06-01

    Multilevel inverters are emerging as a new breed of power converter options for power system applications. Recent advances in power switching devices enabled the suitability of multilevel inverters for high voltage and high power applications because they are connecting several devices in series without the need of component matching. Usually, a transformerless battery energy storage system, based on a cascaded multilevel inverter, is used as a measure for voltage and frequency deviations. System can be reduced in size, weight, and cost of energy storage system. High-frequency link circuit topology is advantageous in realizing compact and light-weight power converters for uninterruptible power supply systems, new energy systems using photovoltaic-cells, fuel-cells and so on. This paper presents a DC-DC type high-frequency link DC (HFLDC) cascaded multilevel inverter. Each converter cell is implemented a control strategy for two H-bridge inverters that are controlled with the same multicarrier pulse width modulation (PWM) technique. The proposed cascaded multilevel inverter generates lower voltage total harmonic distortion (THD) in comparison with conventional cascaded multilevel inverter. Digital simulations are carried out using PSCAD/EMTDC to validate the performance of the proposed cascaded multilevel inverter.

  12. 78 FR 61177 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Science.gov (United States)

    2013-10-03

    ... Distribution Centre (MDC) rack panel is subject to flexing, due to the weight of the two DC Generator Control... Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. Hand Delivery: U.S. Department of...., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service...

  13. Wide Temperature Range DC-DC Boost Converters for Command/Control/Drive Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...

  14. DC Microgrids—Part II

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez

    2016-01-01

    distribution applications such as traction, telecom, vehicular and distributed power systems can be classified under DC MG framework and ongoing development and expansion of the field is largely influenced by concepts used over there. This paper aims firstly to shed light on the practical design aspects of DC...... MG technology concerning typical power hardware topologies and their suitability for different emerging smart grid applications. Then, an overview of the state of the art in DC MG protection and grounding is provided. Owing to the fact that there is no zero current crossing, an arc that appears upon...

  15. Selection of DC/DC converter for offshore wind farms with MVDC power collection

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2017-01-01

    Four DC/DC converters are analyzed and compared with respects to availability, efficiency, ratings, repair costs and power density. Intended application is offshore wind farms with MVDC power collection. The selected topology is a new series resonant converter, which offers 99% efficiency across...

  16. United States’ Grand Strategy through the Lens of Lebanon in 1983 and Iraq in 2003

    Science.gov (United States)

    2012-06-08

    National Security Council. See: Gabriel Marcella , Affairs of State: The Interagency and National Security (Washington, DC: National Strategic Studies... Marcella , Gabriel. Affairs of State: The Interagency and National Security (Washington, DC: National Strategic Studies Institute, December 2008

  17. 78 FR 19533 - Investigations Regarding Eligibility To Apply for Worker Adjustment Assistance

    Science.gov (United States)

    2013-04-01

    ... Constitution Avenue NW., Washington, DC 20210. Signed at Washington, DC, this 20th day of March 2013. Michael W.../13 03/13/13 (Workers). 82559 Kimberly-Clark Corporation-- Belmont, MI 03/14/13 03/12/13 Jackson...

  18. 77 FR 77185 - Veterans' Rural Health Advisory Committee, Notice of Meeting

    Science.gov (United States)

    2012-12-31

    ... Rural Health (ORH), 1722 I Street, NW., Washington, DC. The toll-free number for the meeting is 1- 800... Affairs, 810 Vermont Avenue NW, Washington, DC 20420, or email at rural.health.inquiry@va.gov . Any member...

  19. Integrated Three-Port DC-DC Converter for Photovoltaic (PV) Battery Stand-alone Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2016-01-01

    of solar energy. Moreover, a novel transformer configuration enables variable turns ratio controlled by the phase between the two current excitations subjected to the primary windings, allowing a wider input/output range. 1 kW experimental prototype has been built to demonstrate a wellmanaged power flow......Several power sources such as PV solar arrays and battery are often used to manage the power flow for a photovoltaic (PV) based stand-alone power system due to the fluctuation nature of solar energy resource, and deliver a continuous power to the users in an appropriate form. Traditionally, three...... different single-input single-output (SISO) dc/dc converters would have been used. To reduce the cost and improve the power density of the system, an integrated three-port isolated dc/dc converter is proposed in this paper. It can realize all functions of the energy delivery due to the fluctuation nature...

  20. Integrating DC/DC Conversion with Possible Reconfiguration within Submodule Solar Photovoltaic Systems

    Science.gov (United States)

    Huang, Peter Jen-Hung

    This research first proposes a method to merge photovoltaic (PV) cells or PV panels within the internal components DC-DC converters. The purpose of this merged structure is to reconfigure the PV modules between series and parallel connections using high switching frequencies (hundreds of kHz). This leads to multi-levels of voltages and currents that become applied to the output filter of the converter. Further, this research introduces a concept of a switching cell that utilizes the reconfiguration of series and parallel connections in DC-DC converters. The switching occurs at high switching frequency and the switches can be integrated to be within the solar panels or in between the solar cells. The concept is generalized and applied to basic buck and boost topologies. As examples of the new types of converters: reconfigurable PV-buck and PV-boost converter topologies are presented. It is also possible to create other reconfigurable power converters: non-isolated and isolated topologies. Analysis, simulation and experimental verification for the reconfigurable PV-buck and PV-boost converters are presented extensively to illustrate proof of concept. Benefits and drawbacks of the new approach are discussed. The second part of this research proposes to utilize the internal solar cell capacitance and internal solar module wire parasitic inductances to replace the input capacitor and filter inductor in boost derived DC-DC converters for energy harvesting applications. High switching frequency (MHz) hard switched and resonant boost converters are proposed. Their analysis, simulation and experimental prototypes are presented. A specific proof-of-concept application is especially tested for foldable PV panels, which are known for their high internal wire inductance. The experimental converters successfully boost solar module voltage without adding any external input capacitance or filter inductor. Benefits and drawbacks of new proposed PV submodule integrated boost

  1. Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

    Energy Technology Data Exchange (ETDEWEB)

    Adib, Ehsan; Farzanehfard, Hosein [Dept. of Electrical and Computer Engineering, Isfahan Univ. of Technology (Iran)

    2009-12-15

    In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis. (author)

  2. Retrospective evaluation of early and aggressive decompressive craniectomy (DC) for severe head injury. Was that DC necessary?

    International Nuclear Information System (INIS)

    Hagihara, Yasushi; Ueno, Masato; Mizushima, Yasuaki; Matsuoka, Tetsuya

    2011-01-01

    Recently, decompressive craniectomy (DC) for refractory intracranial hypertension (IH) has been widely reevaluated, and many researchers support the advantages of early and aggressive DC in the management of severe head trauma. We too applied DC in the early stages of IH, and confirmed its favorable results compared to those of the standard treatment. In patients with evacuate masses (EM), DC was determined based on the intraoperative condition of the brain parenchyma; in those without EM, intracranial pressure (ICP) ≥30 mmHg was considered the criterion for DC. However, in some cases, the expected brain edema (BE) was absent after DC, and DC seemed unnecessary on retrospection. Here, the effectiveness of DC performed at our hospital and its predictive factors were investigated. Of the 26 DCs performed in the past 3.5 years, 9 were ineffective because the expected BEs were absent on postoperative computed tomography. In those 9 cases, the Glasgow coma scale (GCS) scores and D-dimer of fibrinogen degradation product (FDP-DD) were significantly higher and lower, respectively, than those of the control group. Patients with EM showed similar trends regarding the GCS score and FDP-DD, both of which are probable indicators of BE. In patients without EM, the GCS score and FDP-DD were normal, but their base excess at admission was significantly low with increased ICP, requiring DC. GCS score and FDP-DD may represent the extent of mechanically damaged brain, and this may explain their relation with DC effectiveness in patients with EM. In patients without EM and with mild brain damage, base excess that reflects the respiratory or circulatory disorder should be the predictor for BE. (author)

  3. Exploration of Charge Recycling DC-DC Conversion Using a Switched Capacitor Regulator

    Directory of Open Access Journals (Sweden)

    Mircea R. Stan

    2013-07-01

    Full Text Available The increasing popularity of DVFS (dynamic voltage frequency scaling schemes for portable low power applications demands highly efficient on-chip DC-DC converters. The primary aim of this work is to enable increased efficiency of on-chip DC-DC conversion for near-threshold operation of multicore chips. The idea is to supply nominal (high off-chip voltage to the cores which are then “voltage-stacked” to generate the near-threshold (low voltages based on Kirchhoff’s voltage law through charge recycling. However, the effectiveness of this implicit down-conversion is affected by the current imbalance among the cores. The paper presents a design methodology and optimization strategy for highly efficient charge recycling on-chip regulation using a push-pull switched capacitor (SC circuit. A dual-boundary hysteretic feedback control circuit has been designed for stacked loads. A stacked-voltage domain with its self-regulation capability combined with a SC converter has shown average efficiency of 78%–93% for 2:1 down-conversion with ILoad (max of 200 mA and workload imbalance varying from 0–100%.

  4. Hierarchical Control for Multiple DC-Microgrids Clusters

    DEFF Research Database (Denmark)

    Shafiee, Qobad; Dragicevic, Tomislav; Vasquez, Juan Carlos

    2014-01-01

    DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed in this p......DC microgrids (MGs) have gained research interest during the recent years because of many potential advantages as compared to the ac system. To ensure reliable operation of a low-voltage dc MG as well as its intelligent operation with the other DC MGs, a hierarchical control is proposed...

  5. High-Efficiency High Step-Up DC-DC Converter with Dual Coupled Inductors for Grid-Connected Photovoltaic Systems

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Shen, Yanfeng; Siwakoti, Yam Prasad

    2018-01-01

    with a common ground connection of the input and output make the proposed topology a proper candidate for a transformer-less grid connected photovoltaic systems. The operating performance, analysis and mathematical derivations of the proposed dc-dc converter have been demonstrated in the paper. Moreover......This paper introduces a non-isolated high step-up dc-dc converter with dual coupled inductors suitable for distributed generation applications. By implementing an input parallel connection, the proposed dc-dc structure inherits shared input current with low ripple, which also requires small...... capacitive filter at its input. Moreover, this topology can reach high voltage gain by using dual coupled inductors in series connection at the output stage. The proposed converter uses active clamp circuits with a shared clamp capacitor for the main switches. In addition to the active clamp circuit...

  6. Design and Implementation of Anti-windup PI Control on DC-DC Bidirectional Converter for Hybrid Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Muh. Zakiyullah Romdlony

    2012-07-01

    Full Text Available Well-regulated DC bus voltage is the important point to guarantee the power demand in hybrid vehicle applications. Voltage regulation can be achieved with control method that build switching signal on DC-DC converter. This paper describes design and small scale experimental results of bus voltage regulation control of the DC-DC bidirectional converter with battery and supercapacitor as energy source. The control system consists of two control loops, the outer loop that get DC bus voltage feedback using PI anti-windup back calculation control method. This outer loop will generate a reference current for the inner loop that implement hysteresis control. The inner control loop will compare that reference curent with the source current obtained from the current sensor. Simulation and experimental results show that bus voltage is well-regulated under the load changes with 1% voltage ripple.

  7. Light-weight DC to very high voltage DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  8. Current Mode Control for LLC Series Resonant DC-to-DC Converters

    OpenAIRE

    Jinhaeng Jang; Syam Kumar Pidaparthy; Byungcho Choi

    2015-01-01

    Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a...

  9. University of Washington

    Data.gov (United States)

    Federal Laboratory Consortium — The theme of the University of Washington based Center for Child Environmental Health Risks Research (CHC) is understanding the biochemical, molecular and exposure...

  10. 78 FR 13213 - Regional Reliability Standard PRC-006-NPCC-1- Automatic Underfrequency Load Shedding

    Science.gov (United States)

    2013-02-27

    ...-006- NPCC-1 applies to generator owners, planning coordinators, distribution providers, and... Street NE., Washington, DC 20426, Telephone: (202) 502-6750, [email protected] . Matthew... First Street NE., Washington, DC 20426, Telephone: (202) 502-8408, [email protected

  11. 77 FR 30593 - Veterans' Rural Health Advisory Committee, Notice of Meeting

    Science.gov (United States)

    2012-05-23

    ...), 1722 I Street NW., Washington, DC. The toll-free number for the meeting is 1-800-767-1750, and the...., Washington, DC 20420, or email at rural.health.inquiry@va.gov . Any member of the public seeking additional...

  12. 78 FR 57221 - Citizens Coinage Advisory Committee Meeting

    Science.gov (United States)

    2013-09-17

    ... members of the public may attend the meeting at the United States Mint; 801 9th Street NW.; Washington, DC... CONTACT: William Norton, United States Mint Liaison to the CCAC; 801 9th Street NW.; Washington, DC 20220...

  13. Proceedings of the IDA Workshop on Formal Specification and Verification of Ada (Trade Name) (1st) Held in Alexandria, Virginia on 18-20 March 1985.

    Science.gov (United States)

    1985-12-01

    on the third day. 5 ADA VERIFICATION WORKSHOP MARCH 18-20, 1985 LIST OF PARTICIPANTS Bernard Abrams ABRAMS@ADA20 Grumman Aerospace Corporation Mail...20301-3081 (202) 694-0211 Mark R. Cornwell CORNWELL @NRL-CSS Code 7590 Naval Research Lab Washington, D.C. 20375 (202) 767-3365 Jeff Facemire FACEMIRE...accompanied by descriptions of their purpose in English, to LUCKHAM@SAIL for annotation. - X-2 DISTRIBUTION LIST FOR M-146 Bernard Abrams ABRAMS@USC-ECLB

  14. Floating high step-down stacked dc-dc converter based on buck-boost cells

    NARCIS (Netherlands)

    Tibola, G.; Duarte, J.L.; Blinov, A.

    2015-01-01

    In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a

  15. UNJUK KERJA PENGUBAH TEGANGAN DC-DC TOPOLOGI BOOST DENGAN NILAI INDUKTANSI DAN KAPASITANSI YANG DIOPTIMASI PADA KEADAAN TRANSIEN

    Directory of Open Access Journals (Sweden)

    I Wayan Arta Wijaya

    2009-05-01

    Full Text Available Pengubah daya DC-DC topologi boost dapat menghasilkan tegangan yang lebih tinggi dari tegangan input dengan riak (ripple yang kecil dan efisiensi yang cukup tinggi. Nilai dari sebuah induktansi dan kapasitansi dari pengubah daya DC-DC dengan menggunakan topologi boost dioptimalkan menggunakan analisa transien. Fungsi ini diatur berdasarkan pada analisa dari pengubah daya selama kondisi transien. Nilai induktansi dan kapasitansi yang telah dioptimalkan dengan perhitungan dibandingkan dalam simulasi pada pengubah daya DC-DC dan hasilnya akan dibuktikan dengan menggunakan hasil percobaan. Nilai optimal untuk kapasitor dan induktor pada frekuensi 666,7 Hz, siklus kerja (duty cycle 66,7 %, resistansi output 36 Ώ dan tegangan input 12 volt adalah 1038 μF dan 11,9 mH

  16. Rhesus macaque and chimpanzee DC-SIGN act as HIV/SIV gp120 trans-receptors, similar to human DC-SIGN

    NARCIS (Netherlands)

    Geijtenbeek, T. B.; Koopman, G.; van Duijnhoven, G. C.; van Vliet, S. J.; van Schijndel, A. C.; Engering, A.; Heeney, J. L.; van Kooyk, Y.

    2001-01-01

    Dendritic cells (DC) have been implicated in the pathogenesis of both human and simian immunodeficiency viruses (HIV and SIV, respectively). The DC-specific HIV-1 trans-receptor DC-SIGN is thought to be essential for viral dissemination by DC. Abundant expression in lymphoid tissues also implies a

  17. The Chaotic-Based Control of Three-Port Isolated Bidirectional DC/DC Converters for Electric and Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    2016-01-01

    Full Text Available Three-port isolated (TPI bidirectional DC/DC converters have three energy ports and offer advantages of large voltage gain, galvanic isolation ability and high power density. For this reason this kind of converters are suitable to connect different energy sources and loads in electric and hybrid vehicles. The purpose of this paper is to propose chaotic modulation and the related control scheme for TPI bidirectional DC/DC converters, in such a way that the switching harmonic peaks can be suppressed in spectrum and the conducted electromagnetic interference (EMI is reduced. Two chaotic modulation strategies, namely the continuously chaotic modulation and the discretely chaotic modulation are presented. These two chaotic modulation strategies are applied for TPI bidirectional DC/DC converters with shifted-phase angle based control and phase-shifted PWM control. Both simulation and experiments are given to verify the validity of the proposed chaotic modulation-based control schemes.

  18. Poder, Ideología y el Consenso de Washington: Desarrollo y Expansión de la Política Chilena de Vivienda.

    Directory of Open Access Journals (Sweden)

    Alan Gilbert

    2003-01-01

    Full Text Available Es bien sabido que a menudo la realidad supera la ficción. Esto ciertamente se aplica en el caso del modelo de subsidio habitacional en Chile. Desarrollado por los chilenos con ayuda de la ideología neo-liberal inventada en Chicago, las poderosas instituciones de Washington DC aparecen como actores menores en la escena chilena. Inicialmente, Chile necesitaba el apoyo y financiamiento del Banco Mundial pero una vez conseguidos, Chile siguió su propia agenda. El Banco de Desarrollo Interamericano y USAID no lograron mucho más. Chile era el amo y señor en su propia casa. ¿Fue ésta una victoria para la autonomía nacional por sobre el poder del financiamiento internacional?. Ciertamente no, porque el nuevo modelo que se estaba aplicando en Chile fue el precursor de mucho de lo que se estaba implementando desde Washington en los días de ajuste estructural. Chile “ganó” porque aceptó las reglas del nuevo juego establecido por instituciones muchísimo más poderosas que los bancos de desarrollo multilaterales. Washington del Desarrollo aprendió mucho de Chile y luego aplicó lo aprendido a los países más endeudados, más pequeños y menos sofisticados.

  19. A Markovian Approach Applied to Reliability Modeling of Bidirectional DC-DC Converters Used in PHEVs and Smart Grids

    Directory of Open Access Journals (Sweden)

    M. Khalilzadeh

    2016-12-01

    Full Text Available In this paper, a stochastic approach is proposed for reliability assessment of bidirectional DC-DC converters, including the fault-tolerant ones. This type of converters can be used in a smart DC grid, feeding DC loads such as home appliances and plug-in hybrid electric vehicles (PHEVs. The reliability of bidirectional DC-DC converters is of such an importance, due to the key role of the expected increasingly utilization of DC grids in modern Smart Grid. Markov processes are suggested for reliability modeling and consequently calculating the expected effective lifetime of bidirectional converters. A three-leg bidirectional interleaved converter using data of Toyota Prius 2012 hybrid electric vehicle is used as a case study. Besides, the influence of environment and ambient temperature on converter lifetime is studied. The impact of modeling the reliability of the converter and adding reliability constraints on the technical design procedure of the converter is also investigated. In order to investigate the effect of leg increase on the lifetime of the converter, single leg to five-leg interleave DC-DC converters are studied considering economical aspect and the results are extrapolated for six and seven-leg converters. The proposed method could be generalized so that the number of legs and input and output capacitors could be an arbitrary number.

  20. 77 FR 59151 - Regional Reliability Standard PRC-006-NPCC-1-Automatic Underfrequency Load Shedding

    Science.gov (United States)

    2012-09-26

    ... approval. The proposed regional Reliability Standard applies to generator owners, planning coordinators... Commission, Secretary of the Commission, 888 First Street NE., Washington, DC 20426. Instructions: For... Commission, 888 First Street NE., Washington, DC 20426, Telephone: (202) 502-6750, [email protected

  1. Informal Science Educators' Views about Nature of Scientific Knowledge

    Science.gov (United States)

    Holliday, Gary M.; Lederman, Norman G.

    2014-01-01

    Publications such as "Surrounded by science: Learning science in informal environments" [Fenichel, M., & Schweingruber, H. A. (2010). Washington, DC: The National Academies Press] and "Learning science in informal environments: People, places, and pursuits" [National Research Council. (2009). Washington, DC: National…

  2. Applying a Qualitative Modeling Shell to Process Diagnosis: The Caster System.

    Science.gov (United States)

    1986-03-01

    of Leyden AFOSR Baltimore, MD 21204 Education Research Center Boiling AFB Boerhaavelaan 2 Washington, DC 20332 Dr. Davida Charney 2334 EN Leyden ...Charles Lewis Washington, DC 20002 Department of Psychology Faculteit Sociale Wetenschappen Dr. Kathleen McKeown Community College of Rijksuniversiteit

  3. 78 FR 1832 - National Wildlife Services Advisory Committee; Notice of Solicitation for Membership

    Science.gov (United States)

    2013-01-09

    ...., Washington, DC 20250, Attn: Secretary's National Wildlife Services Advisory Committee. Nomination packages... demonstrated ability to represent minorities, women, and persons with disabilities. Done in Washington, DC... Services Advisory Committee. DATES: Consideration will be given to nominations received on or before March...

  4. PI and Fuzzy Control Strategies for High Voltage Output DC-DC Boost Power Converter - Hardware Implementation and Analysis

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Siano, Pierluigi

    2016-01-01

    This paper presents the control strategies by Proportional-Integral (P-I) and Fuzzy Logic (FL) for a DC-DC boost power converter for high output voltage configuration. Standard DC-DC converters are traditionally used for high voltage direct current (HVDC) power transmission systems. But, lack its...... converter with inbuilt voltage-lift technique and overcome the aforementioned deficiencies. Further, the control strategy is adapted based on proportional-integral (P-I) and fuzzy logic, closed-loop controller to regulate the outputs and ensure the performances. Complete hardware prototype of EHV converter...... performances in terms of efficiency, reduced transfer gain and increased cost with sensor units. Moreover, the internal self-parasitic components reduce the output voltage and efficiency of classical high voltage converters (HVC). This investigation focused on extra high-voltage (EHV) DC-DC boost power...

  5. A Novel Quasi-SEPIC High-Voltage Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; N. Soltani, Mohsen; Blaabjerg, Frede

    2017-01-01

    This paper proposes a modified coupled-inductor SEPIC dc-dc converter for low power and high voltage gain applications such as for piezoelectric drive systems. The converter uses the same components as of SEPIC converter with an additional diode. Compared to conventional topologies with similar...... voltage gain expression, the proposed topology uses less components to achieve same or even higher voltage gain. This helps to design a very compact and light weight converter with higher power density at lower cost. Due to brevity, the principle of operation, theoretical analysis and comparison supported...

  6. Properties of DLC coatings deposited by dc and dc with superimposed pulsed vacuum arc

    International Nuclear Information System (INIS)

    Zavaleyev, V.; Walkowicz, J.; Aksyonov, D.S.; Luchaninov, A.A.; Reshetnyak, E.N.; Strel'nitskij, V.E.

    2014-01-01

    Comparative studies of the structure, mechanical and tribological properties of DLC coatings deposited in DC and DC with superimposed high current pulse modes of operation vacuum-arc plasma source with the graphite cathode are presented. Imposition the pulses of high current on DC vacuum-arc discharge allows both increase the deposition rate of DLC coating and reduce the residual compressive stress in the coatings what promotes substantial improvement the adhesion to the substrate. Effect of vacuum arc plasma filtration with Venetian blind filter on the deposition rate and tribological characteristics of the coatings analyzed.

  7. Light-weight DC to very high voltage DC converter

    Science.gov (United States)

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  8. The 25 kW resonant dc/dc power converter

    Science.gov (United States)

    Robson, R. R.

    1983-01-01

    The feasibility of processing 25-kW of power with a single, transistorized, series resonant converter stage was demonstrated by the successful design, development, fabrication, and testing of such a device which employs four Westinghouse D7ST transistors in a full-bridge configuration and operates from a 250-to-350 Vdc input bus. The unit has an overall worst-case efficiency of 93.5% at its full rated output of 1000 V and 25 A dc. A solid-state dc input circuit breaker and output-transient-current limiters are included in and integrated into the design. Full circuit details of the converter are presented along with the test data.

  9. DC grid for home applications

    Science.gov (United States)

    Elangovan, D.; Archana, R.; Jayadeep, V. J.; Nithin, M.; Arunkumar, G.

    2017-11-01

    More than fifty percent Indian population do not have access to electricity in daily lives. The distance between the power generating stations and the distribution centers forms one of the main reasons for lack of electrification in rural and remote areas. Here lies the importance of decentralization of power generation through renewable energy resources. In the present world, electricity is predominantly powered by alternating current, but most day to day devices like LED lamps, computers and electrical vehicles, all run on DC power. By directly supplying DC to these loads, the number of power conversion stages was reduced, and overall system efficiency increases. Replacing existing AC network with DC is a humongous task, but with power electronic techniques, this project intends to implement DC grid at a household level in remote and rural areas. Proposed work was designed and simulated successfully for various loads amounting to 250 W through appropriate power electronic convertors. Maximum utilization of the renewable sources for domestic and commercial application was achieved with the proposed DC topology.

  10. Management of Bottom Sediments Containing Toxic Substances. Proceedings of the U.S./Japan Experts Meeting (8th) Held at Tokyo, Japan on 8-10 November 1982

    Science.gov (United States)

    1984-07-01

    Erosion Board, Washington, D.C., May 1950. HALL, J.V. and WATTS, G.M.,, Beach Rehabilitation by Fill and Nourishment. TYazactionz o6 the AmeAican...Demonstration Project 9J a statistically significant 1ioaccumulation of PCB. The capping exercise was based upon two premises: (1) that the capped mound would...Health., 18:22-2.9 (1969). (6) Prineas, .𔃻. Tre pathogenesis of dying-back polyneuropathies , II. An ultrastructural study of experimental acrylamide

  11. Advances and trends in structures and dynamics; Proceedings of the Symposium, Washington, DC, October 22-25, 1984

    Science.gov (United States)

    Noor, A. K. (Editor); Hayduk, R. J. (Editor)

    1985-01-01

    Among the topics discussed are developments in structural engineering hardware and software, computation for fracture mechanics, trends in numerical analysis and parallel algorithms, mechanics of materials, advances in finite element methods, composite materials and structures, determinations of random motion and dynamic response, optimization theory, automotive tire modeling methods and contact problems, the damping and control of aircraft structures, and advanced structural applications. Specific topics covered include structural design expert systems, the evaluation of finite element system architectures, systolic arrays for finite element analyses, nonlinear finite element computations, hierarchical boundary elements, adaptive substructuring techniques in elastoplastic finite element analyses, automatic tracking of crack propagation, a theory of rate-dependent plasticity, the torsional stability of nonlinear eccentric structures, a computation method for fluid-structure interaction, the seismic analysis of three-dimensional soil-structure interaction, a stress analysis for a composite sandwich panel, toughness criterion identification for unidirectional composite laminates, the modeling of submerged cable dynamics, and damping synthesis for flexible spacecraft structures.

  12. Static and Dynamic Characteristics of DC-DC Converter Using a Digital Filter

    Science.gov (United States)

    Kurokawa, Fujio; Okamatsu, Masashi

    This paper presents the regulation and dynamic characteristics of the dc-dc converter with digital PID control, the minimum phase FIR filter or the IIR filter, and then the design criterion to improve the dynamic characteristics is discussed. As a result, it is clarified that the DC-DC converter using the IIR filter method has superior performance characteristics. The regulation range is within 1.3%, the undershoot against the step change of the load is less than 2% and the transient time is less than 0.4ms with the IIR filter method. In this case, the switching frequency is 100kHz and the step change of the load R is from 50 Ω to 10 Ω. Further, the superior characteristics are obtained when the first gain, the second gain and the second cut-off frequency are relatively large, and the first cut-off frequency and the passing frequency are relatively low. Moreover, it is important that the gain strongly decreases at the second cut-off frequency because the upper band pass frequency range must be always less than half of the sampling frequency based on the sampling theory.

  13. Washington Tsunami Hazard Mitigation Program

    Science.gov (United States)

    Walsh, T. J.; Schelling, J.

    2012-12-01

    Washington State has participated in the National Tsunami Hazard Mitigation Program (NTHMP) since its inception in 1995. We have participated in the tsunami inundation hazard mapping, evacuation planning, education, and outreach efforts that generally characterize the NTHMP efforts. We have also investigated hazards of significant interest to the Pacific Northwest. The hazard from locally generated earthquakes on the Cascadia subduction zone, which threatens tsunami inundation in less than hour following a magnitude 9 earthquake, creates special problems for low-lying accretionary shoreforms in Washington, such as the spits of Long Beach and Ocean Shores, where high ground is not accessible within the limited time available for evacuation. To ameliorate this problem, we convened a panel of the Applied Technology Council to develop guidelines for construction of facilities for vertical evacuation from tsunamis, published as FEMA 646, now incorporated in the International Building Code as Appendix M. We followed this with a program called Project Safe Haven (http://www.facebook.com/ProjectSafeHaven) to site such facilities along the Washington coast in appropriate locations and appropriate designs to blend with the local communities, as chosen by the citizens. This has now been completed for the entire outer coast of Washington. In conjunction with this effort, we have evaluated the potential for earthquake-induced ground failures in and near tsunami hazard zones to help develop cost estimates for these structures and to establish appropriate tsunami evacuation routes and evacuation assembly areas that are likely to to be available after a major subduction zone earthquake. We intend to continue these geotechnical evaluations for all tsunami hazard zones in Washington.

  14. DC-Compensated Current Transformer †

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  15. Reliability study of high gain DC-DC converters based on RRPP I-IIA ...

    Indian Academy of Sciences (India)

    J DIVYA NAVAMANI

    2018-05-10

    May 10, 2018 ... Energy Storage Modules (ESM), Propulsion Motor Mod- ules (PMM) and ... All Electric Ship (AES) is the best way to power all the loads in the ship ... also used to derive quadratic step down DC-DC converters. [6]. The attractive ...... Exhibition on Ecological Vehicles and Renewable Energies,. TamilNadu ...

  16. Influence of DC arc jets on flow fields analyzed by an integrated numerical model for a DC-RF hybrid plasma

    International Nuclear Information System (INIS)

    Seo, Jun Ho; Park, Jin Myung; Hong, Sang Hee

    2008-01-01

    The influence of DC arc jets on the flow fields in a hybrid plasma torch is numerically analyzed by an integrated direct current-radio frequency (DC-RF) plasma model based on magneto-hydrodynamic formulations. The calculated results reveal that the increase in DC arc gas flow rate raises the axial flow velocity along the central column of the DC-RF hybrid plasma together with the enhanced backflow streams in the peripheral wall region. The temperature profiles on the torch exit plane are little affected due to the reheating process of the central column by the combined RF plasma. Accordingly, the exit enthalpy emitted from the DC-RF hybrid torch can be concentrated to the central column of the plasma and controlled by adjusting the DC arc gas flow rate. The swirl in the sheath gas flow turns out to have the opposite effect on the DC arc gas flow rate. The swirling motion of the sheath gas can reduce the back flows near the induction tube wall as well as the axial velocities in the central column of the plasma. Accordingly, the swirl in the sheath gas flow can be used for the functional operation of the DC-RF hybrid plasma along with the DC arc gas flow rate to suppress the back flows at the wall region and to reduce the excessive interactions between the DC arc jet and the ambient RF plasmas. The effects of DC input current on the flow fields of hybrid plasma are similar to those of the DC arc gas flow rate, but the axial velocities for the higher current relatively quickly decay along the centerline. This is in contrast to the increase in the axial velocity remaining in proportion to the increase in the DC arc gas flow rate all the way up to the exit of the DC-RF hybrid plasma. Accordingly, the present integrated numerical analysis suggests that the hybrid plasma field profiles and the entrainment of ambient air from the torch exit are controllable by adjusting the DC arc gas flow rate, the DC input current and swirl in the sheath gas flow taking advantage of

  17. Dilation and Curettage (D&C)

    Science.gov (United States)

    ... For Patients About ACOG Dilation and Curettage (D&C) Home For Patients Search FAQs Dilation and Curettage ( ... February 2016 PDF Format Dilation and Curettage (D&C) Special Procedures What is dilation and curettage (D& ...

  18. The Commander’s Emergency Response Program: A Model for Future Implementation

    Science.gov (United States)

    2010-04-07

    Koontz (Washington D.C.: Center of Military History, 2008), 543. Historically, military humanitarian aid operations have utilized manpower...Enduring Voices: Oral Histories of the U.S. Army Experience in Afghanistan 2003-2005. Edited by Christopher Koontz Washington D.C.: Center of Military

  19. 7 CFR 2.91 - Director, Office of Operations.

    Science.gov (United States)

    2010-01-01

    ..., excess property pool, resource recovery, shipping and receiving, forms, labor services, issuing of... maintaining the security of physical facilities, self-protection, and warden services, in the Washington, DC..., Office of Operations: (1) Provide services for Department headquarters in the Washington, DC metropolitan...

  20. 40 CFR 262.83 - Notification and consent.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Transfrontier Shipments of Hazardous Waste...), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460, with the words “Attention... (2254A), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460, with the...

  1. 40 CFR 262.53 - Notification of intent to export.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Exports of Hazardous Waste § 262.53...), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. Hand-delivered notifications... St. and Pennsylvania Ave., NW., Washington, DC 20004. In both cases, the following shall be...

  2. Qualitative Student Models,

    Science.gov (United States)

    1986-05-01

    University of Leyden AFOSR Baltimore, MD 21204 Education Research Center Bol g Boerhaavelaan 2 asolling ADCDr. Davida Charney 2334 EN Leyden Washington, DC...Kotovsky Dr. Charles Lewis Washington, DC 20002Department of Psychology Faculteit Sociale Wetenschappen Dr. Kathleen McKeownCommunity College of

  3. Using and Evaluating Differential Modeling in Intelligent Tutoring and Apprentice Learning Systems.

    Science.gov (United States)

    1987-01-01

    University of Leyden AFOSR Baltimore, Yj 21204 Education Research Center Boiling AFB Boerhaavelaan 2 Washington, DC 20332Dr. Davida Charney 2334 EN Leyden ...Washington, DC * Dr. Kenneth Kotovsky Dr. Charles Lewis Department ot Psychology Faculteit Sociale Wetenschappen Dr. Kathleen McKeuwn Community College

  4. NASA/DoD Aerospace Knowledge Diffusion Research Project. Report Number 6. The Relationship between the Use of U.S. Government Technical Reports by U.S. Aerospace Engineers and Scientists and Selected Institutional and Sociometric Variables

    Science.gov (United States)

    1991-01-01

    Peter R.; James D. Schriner; Bettie F. Farace ; and Richard V. Farace . The Assessment of NASA Technical Information. NASA CR-181367. Washington, DC... Farace ; and Richard V. Farace . The Assessment of NASA Technical Information. NASA CR-181367. Washington, DC: National Aeronautics and Space

  5. 76 FR 7590 - Distribution of 2000, 2001, 2002, and 2003 Cable Royalty Funds

    Science.gov (United States)

    2011-02-10

    ... Madison Memorial Building, LM-401, 101 Independence Avenue, SE., Washington, DC 20559-6000. If delivered... Madison Memorial Building, LM-403, 101 Independence Avenue, SE., Washington, DC 20559-6000. FOR FURTHER... of the major categories of copyrightable content (movies, sports programming, music, etc.) requesting...

  6. Ultrahigh-density trench cpacitors in silicon and their application to integrated DC-DC conversion

    NARCIS (Netherlands)

    Roozeboom, F.; Bergveld, H.J.; Nowak, K.; Le Cornec, F.; Guiraud, L.; Bunel, C.; Iochem, S.; Ferreira, J.; Ledain, S.; Pieraerts, E.; Pommier, M.

    2009-01-01

    This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an

  7. Spectral shaping of a randomized PWM DC-DC converter using maximum entropy probability distributions

    CSIR Research Space (South Africa)

    Dove, Albert

    2017-01-01

    Full Text Available maintaining constraints in a DC-DC converter is investigated. A probability distribution whose aim is to ensure maximal harmonic spreading and yet mainaint constraints is presented. The PDFs are determined from a direct application of the method of Maximum...

  8. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  9. Hybrid Non-Isolated and Non Inverting Nx Interleaved DC-DC Multilevel Boost Converter for Renewable Energy Applications

    DEFF Research Database (Denmark)

    Bhaskar, Mahajan Sagar; Kulkarni, Rishi M.; Padmanaban, Sanjeevi Kumar

    2016-01-01

    In this paper hybrid non isolated/ non inverting Nx interleaved DC-DC multilevel Boost Converter for renewable energy applications is presented. The presented hybrid topology is derived from the conventional interleaved converter and the Nx Multilevel boost converter. In renewable energy...... applications, generated energy cannot be directly used at application end. In most of the cases it needs to be stepped up with DC-DC converter at operating voltage levels as per the requirement of the application. Though conventional boost converter can theoretically be used for this purpose, but obtaining...

  10. A comprehensive analysis and hardware implementation of control strategies for high output voltage DC-DC boost power converter

    OpenAIRE

    Padmanaban, Sanjeevikumar; Grandi, Gabriele; Blaabjerg, Frede; Wheeler, Patrick; Siano, Pierluigi; Hammami, Manel

    2017-01-01

    Classical DC-DC converters used in high voltage direct current (HVDC) power transmission systems, lack in terms of efficiency, reduced transfer gain and increased cost with sensor (voltage/current) numbers. Besides, the internal self-parasitic behavior of the power components reduces the output voltage and efficiency of classical HV converters. This paper deals with extra high-voltage (EHV) dc-dc boost converter by the application of voltage-lift technique to overcome the aforementioned defic...

  11. Proceedings of the Cloud Impacts on DoD Operations and Systems 1993 Conference (CIDOS - 93) Held in Fort Belvoir, Virginia on 16-19 November 1993

    Science.gov (United States)

    1994-07-01

    t (0704-0 188). Washington. DC 20503 1. AGENCY USE ONLY (Leave blank) 12. REPORT DATE 3 REPORT TYPE AND DATES COVERED I 1 July 1994I cientific ...this Conference. Only pursuits which could legitimately be reported in a refereed technical journal are included in this accounting. The A;r Force...COMMAND HANSCOM AIR FORCE BASE, MA 01731-3010 94-32914 This report has been reviewed by the ESC Public Affairs Office (PA) and is releasable to the

  12. Direct switching control of DC-DC power electronic converters using hybrid system theory

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J.; Lin, F. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wang, C. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wayne State Univ., Detroit, MI (United States). Div. of Engineering Technology

    2010-07-01

    A direct switching control (DSC) scheme for power electronics converters was described. The system was designed for use in both traditional and renewable energy applications as well as in electric drive vehicles. The proposed control scheme was based on a detailed hybrid system converter model that used model predictive control (MPC), piecewise affine (PWA) approximations and constrained optimal control methods. A DC-DC converter was modelled as a hybrid machine. Switching among different modes of the DC-DC converter were modelled as discrete events controlled by the hybrid controller. The modelling scheme was applied to a Buck converter. The DSC was used to control the switch of the power converter based on a hybrid machine model. Results of the study showed that the method can be used to regulate output voltage and inductor currents. The method also provides fast transient responses and effectively regulates both currents and voltage. The controller can be used to provide immediate responses to dynamic disturbances and output voltage fluctuations. 23 refs., 7 figs.

  13. Informational model verification of ZVS Buck quasi-resonant DC-DC converter

    Science.gov (United States)

    Vakovsky, Dimiter; Hinov, Nikolay

    2016-12-01

    The aim of the paper is to create a polymorphic informational model of a ZVS Buck quasi-resonant DC-DC converter for the modeling purposes of the object. For the creation of the model is applied flexible open standards for setting, storing, publishing and exchange of data in distributed information environment. The created model is useful for creation of many and different by type variants with different configuration of the composing elements and different inner model of the examined object.

  14. Switched capacitor DC-DC converter with switch conductance modulation and Pesudo-fixed frequency control

    DEFF Research Database (Denmark)

    Larsen, Dennis Øland; Vinter, Martin; Jørgensen, Ivan Harald Holger

    A switched capacitor dc-dc converter with frequency-planned control is presented. By splitting the output stage switches in eight segments the output voltage can be regulated with a combination of switching frequency and switch conductance. This allows for switching at predetermined frequencies, 31...

  15. A Novel Dual-input Isolated Current-Fed DC-DC Converter for Renewable Energy System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2010-01-01

    In this paper, a novel isolated current-fed DC-DC converter (boost-type) with two input power sources based on multi-transformer structure, which is suitable for fuel cells and super-capacitors hybrid energy system, is proposed and designed. With particular transformer windings connection strategy...

  16. Experience from design, prototyping and production of a DC-DC conversion powering scheme for the CMS Phase-1 Pixel Upgrade

    International Nuclear Information System (INIS)

    Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Preuten, M.; Rauch, M.; Schmitz, S.; Wlochal, M.

    2016-01-01

    The CMS collaboration has adopted a DC-DC conversion powering scheme for the Phase-1 Upgrade of its pixel detector. DC-DC buck converters with a conversion ratio of around 3 are installed on the support structures, outside of the sensitive tracking region, requiring a re-design of the low and high voltage distribution to the pixel modules. After several years of R and D, the project has entered the production phase. A total of 1800 DC-DC converters are being produced, and rigorous quality assurance and control is being employed during the production process. The testing program is outlined, results from mass production are presented and issues that have been encountered are described. In addition, two system level challenges, namely the choice of output voltage in the presence of large, load-dependent voltage drops, and the thermal management required to remove the heat load caused by the DC-DC converters, are discussed

  17. Analytical Comparison of Dual-Input Isolated dc-dc Converter with an ac or dc Inductor for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Mira Albert, Maria del Carmen; Andersen, Michael A. E.

    2017-01-01

    This paper presents two configurations of dualinput (DI) or three-port (TPC) isolated dc-dc converters for hybrid renewable energy systems such as photovoltaics and batteries. These two converters are derived by integrating an interleaved boost converter and a single-active bridge converter...... and control perspective, distinct in operation principles, voltage/power transfer functions, loss distributions, soft-switching constraints, and power efficiency under the same operating conditions. Moreover, the inductor design differs greatly between these two cases. In this paper, a comprehensive...

  18. Analysis of a high power, resonant DC-DC converter for DC wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2018-01-01

    This paper is introducing a new method of operation for a series resonant converter, with intended application in megawatt high-voltage DC wind turbines. Compared to a frequency controlled series resonant converter operated in sub resonant mode, the method (entitled pulse removal technique) allows...

  19. High-Efficiency Photovoltaic System Using Partially-Connected DC-DC Converter

    Science.gov (United States)

    Uno, Masatoshi; Kukita, Akio; Tanaka, Koji

    Power conversion electronics for photovoltaic (PV) systems are desired to operate as efficiently as possible to exploit the power generated by PV modules. This paper proposes a novel PV system in which a dc-dc converter is partially connected to series-connected PV modules. The proposed system achieves high power-conversion efficiency by reducing the passing power and input/output voltages of the converter. The theoretical operating principle was experimentally validated. Resultant efficiency performances of the proposed and conventional systems demonstrated that the proposed system was more efficient in terms of power conversion though the identical converter was used for the both systems.

  20. Very High Frequency Resonant DC/DC Converters for LED Lighting

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    This paper presents a very high frequency DC/DC converter for LED lighting. Several resonant topologies are compared and their usability discussed. At the end the resonant SEPIC converter is chosen based on the achievable power density and total bill of material. Simulations of a 51 MHz converter...... with 40 V input and 15 V output are made. The simulation shows possibility of achieving efficiency up to 87 % even with a HEXFET Power MOSFET. Three prototypes of the simulated converter are implemented showing good correlation with simulations. The prototypes have efficiencies up to 84 % and power...

  1. A THREE-PHASE BOOST DC-AC CONVERTER

    African Journals Online (AJOL)

    dc-ac converter (inverter) based on the dc-dc boost converters. ... Sliding mode controllers are designed to perform a robust control for the ... Computer simulations and spectral analysis demon- ... the conventional three-phase buck inverter,.

  2. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne; Yong, Xia

    1999-01-01

    In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form of constra......In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form.......TRSL is a real-time extension of the RAISE Specification Language (RSL) [Rlg92] which together with its associated method [Rmg95]and tools has shown to be very useful in the industrial development of software systems. Therefore, a promising approach for the development of real-time systemscould be to use DC...... for high-level specifications of real-time requirementsand TRSL for specifying real-time implementations in the form of timed communicating concurrent processes.In order to link DC and TRSL together in a well-founded way, we formally define what it means for a TRSL process to satisfy a DC requirement...

  3. Employee Turnover and Absenteeism: A Future Research Agenda.

    Science.gov (United States)

    1981-08-01

    Department (NMPC-6) Washington, DC 20350 Naval Training Analysis and Evaluation Group Orlando, FL 32813 Commanding Officer ATTN: TIC , Bldg. 2068 Naval...RD-i Washington, DC 20380 Educacion Advisor Education Center (E031) MCDEC Quantico, VA 22134 Commanding Officer Education Center (E031) MCDZC Quantico

  4. 77 FR 10511 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

    Science.gov (United States)

    2012-02-22

    ... Activities; Submission to OMB for Review and Approval; Comment Request; Requirements for Generators...), 1200 Pennsylvania Ave. NW., Washington, DC 20460, and (2) OMB by mail to: Office of Information and... NW., Washington, DC 20503. FOR FURTHER INFORMATION CONTACT: Bryan Groce, Office of Resource [[Page...

  5. 77 FR 10478 - Quarterly Update to Annual Listing of Foreign Government Subsidies on Articles of Cheese Subject...

    Science.gov (United States)

    2012-02-22

    ... Constitution Ave. NW., Washington, DC 20230, telephone: (202) 482-3338. SUPPLEMENTARY INFORMATION: Section 702... Constitution Ave., NW., Washington, DC 20230. This determination and notice are in accordance with section 702..., Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and the United Kingdom. [FR Doc...

  6. 76 FR 12643 - Proposed Establishment of Helicopter Area Navigation (RNAV) Routes; Northeast United States

    Science.gov (United States)

    2011-03-08

    ... (RNAV) Routes; Northeast United States AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... northeast corridor between the Washington, DC and New York City metropolitan areas. The FAA is proposing... northeast corridor between the New York City and Washington, DC, metropolitan areas. The routes would serve...

  7. 75 FR 63214 - Errata Notice; Notice of Public Workshop on a Potential Rulemaking for Spent Nuclear Fuel...

    Science.gov (United States)

    2010-10-14

    ... of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, DC 20555..., 2010, workshop will be held at the Hilton Washington, DC/Rockville Hotel & Executive Meeting Center... October 19-20, 2010, at the Sheraton Albuquerque Uptown Hotel, located at 2600 Louisiana Boulevard NE...

  8. 75 FR 10013 - Agency Information Collection Activities: Request for Comments; Renewed Approval of Information...

    Science.gov (United States)

    2010-03-04

    ...., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Kathleen Facer, 785-228-2544, Office of Real Estate... Right-of-Way Operations Manuals, OMB Control Number: 2125-0586 AGENCY: Federal Highway Administration...., Washington, DC 20590. SUPPLEMENTARY INFORMATION: Title: State Right-of-Way Operations Manuals, OMB Control...

  9. 17 CFR 38.3 - Procedures for designation.

    Science.gov (United States)

    2010-04-01

    ... application for designation with the Secretary of the Commission at its Washington, DC, headquarters. Except... partnership or limited liability company, third-party regulatory service, or member or user agreements, that... filing such a request with the Commission at its Washington, DC, headquarters. Withdrawal of an...

  10. 17 CFR 36.3 - Exempt commercial markets.

    Science.gov (United States)

    2010-04-01

    ... provided, shall be filed with the Secretary of the Commission at its Washington, DC headquarters, in... the Secretary of the Commission at its Washington, DC headquarters. Submissions must include the... company, third-party regulatory service, or member or user agreements, that enable or empower the...

  11. 75 FR 57969 - Center for Scientific Review; Notice of Closed Meetings

    Science.gov (United States)

    2010-09-23

    ... applications. Place: The Ritz-Carlton Hotel, 1150 22nd Street, NW., Washington, DC 20037. Contact Person... applications. Place: St. Gregory Hotel, 2033 M Street, NW., Washington, DC 20036. Contact Person: Yvonne.... Place: Villa Florence Hotel, 225 Powell Street, San Francisco, CA 94102. Contact Person: Maria...

  12. USMC Relocation to Guam: Political Pressure and Poor Plam1ing to Blame for an Ill-Postured U.S. Military in the Pacific

    Science.gov (United States)

    2010-03-19

    Projects and Programs to Support a Larger Military Presence (Washington, D.C.: Government Accountability Office, 2009), 1. 22 Akiko Yamamoto , "Rice, on...Washington, D.C.: Government Accountability Office, 2009. Yamamoto , Akiko . "Rice, on Japan Visit, Offers U.S. Regrets Over Alleged Rape

  13. 77 FR 56824 - Notice of Submission for OMB Review; Office of Special Education and Rehabilitative Services...

    Science.gov (United States)

    2012-09-14

    ... DEPARTMENT OF EDUCATION Notice of Submission for OMB Review; Office of Special Education and... Education, 400 Maryland Avenue SW., LBJ, Washington, DC 20202-4537. Copies of the proposed information... Education, 400 Maryland Avenue SW., LBJ, Washington, DC 20202-4537. Requests may also be electronically...

  14. 77 FR 42764 - Distribution of the 2005, 2006, 2007 and 2008 Digital Audio Recording Technology Royalty Funds...

    Science.gov (United States)

    2012-07-20

    ... Congress, James Madison Memorial Building, LM-401, 101 Independence Avenue SE., Washington, DC 20559-6000... Madison Memorial Building, LM-403, 101 Independence Avenue SE., Washington, DC 20559-6000. FOR FURTHER... certain claimants' (i.e., Broadcast Music, Inc., the American Society of Composers, Authors and Publishers...

  15. 75 FR 15668 - Information Collection Activity; Comment Request

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    2010-03-30

    ...., STOP 1522, Room 5159, South Building, Washington, DC 20250-1522. Telephone: (202) 690-1078. Fax: (202...., Washington, DC 20250-1522. Fax: (202) 720-8435. Title: Broadband Grant Program. OMB Control Number: 0572-0127...'' basis. The ``community-oriented connectivity'' concept integrates the deployment of broadband...

  16. 78 FR 52786 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Members Of SGIP 2...

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    2013-08-26

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  17. A Four-Phase High Voltage Conversion Ratio Bidirectional DC-DC Converter for Battery Applications

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    Li-Kun Xue

    2015-06-01

    Full Text Available This study presents a four-phase interleaved high voltage conversion ratio bidirectional DC-DC converter circuit based on coupled inductors and switched capacitors, which can eliminate the defects of conventional high voltage conversion ratio bidirectional DC-DC converters in terms of high-voltage/current stress, less efficiency and low-power limitation. Parallel channels are used to reduce current stress at the low-voltage side and series connected switched capacitors are used to enlarge voltage conversion ratio, reduce voltage stress and achieve auto current sharing. This paper proposes the operation principle, feature analysis and optimization design considerations. On this basis the objectives of high voltage conversion ratio, low voltage/current stress, high power density, high efficiency and high-power applications can be achieved. Some experimental results based on a 500 W prototype converter (24 V to 48 V at low-voltage side, 400 V at high-voltage side are given to verify the theoretical analysis and the effectiveness of the proposed converter.

  18. Model Based Optimization of Integrated Low Voltage DC-DC Converter for Energy Harvesting Applications

    Science.gov (United States)

    Jayaweera, H. M. P. C.; Muhtaroğlu, Ali

    2016-11-01

    A novel model based methodology is presented to determine optimal device parameters for the fully integrated ultra low voltage DC-DC converter for energy harvesting applications. The proposed model feasibly contributes to determine the maximum efficient number of charge pump stages to fulfill the voltage requirement of the energy harvester application. The proposed DC-DC converter based power consumption model enables the analytical derivation of the charge pump efficiency when utilized simultaneously with the known LC tank oscillator behavior under resonant conditions, and voltage step up characteristics of the cross-coupled charge pump topology. The verification of the model has been done using a circuit simulator. The optimized system through the established model achieves more than 40% maximum efficiency yielding 0.45 V output with single stage, 0.75 V output with two stages, and 0.9 V with three stages for 2.5 kΩ, 3.5 kΩ and 5 kΩ loads respectively using 0.2 V input.

  19. The Cost Growth Problem: A Realistic Diagnosis and Solution.

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    1983-06-01

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  20. State trajectories used to observe and control dc-to-dc converters

    Science.gov (United States)

    Burns, W. W., III; Wilson, T. G.

    1976-01-01

    State-plane analysis techniques are employed to study the voltage stepup energy-storage dc-to-dc converter. Within this framework, an example converter operating under the influence of a constant on-time and a constant frequency controller is examined. Qualitative insight gained through this approach is used to develop a conceptual free-running control law for the voltage stepup converter which can achieve steady-state operation in one on/off cycle of control. Digital computer simulation data are presented to illustrate and verify the theoretical discussions presented.