75 FR 53686 - Blue Ribbon Commission on America's Nuclear Future, Transportation and Storage Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-01

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Transportation and Storage Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open...) Subcommittee. The T&S Subcommittee is a subcommittee of the Blue Ribbon Commission on America's Nuclear Future...

76 FR 23798 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-28

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Office of Nuclear... meeting of the Blue Ribbon Commission on America's Nuclear Future (the Commission). The Commission was... high-level wastes--in light of the events in Japan. The second purpose is to allow the Co-chairs of the...

The Impact of Leadership Behaviors of Blue Ribbon Catholic School Principals on School Culture

ERIC Educational Resources Information Center

Cardarelli, Rosaline

2014-01-01

The purpose of this study was to conduct an analysis of six successful Blue Ribbon Catholic schools to determine the relationship between principal's leadership behaviors, teacher's perceptions of principals and resulting school culture within six successful Blue Ribbon schools. A mixed methods approach for analysis was used through both…

Perceptions of Factors Affecting the Relative Effectiveness of Temporary Blue Ribbon State Commissions.

ERIC Educational Resources Information Center

Johnson, Janet Rogers-Clarke

Elements in the composition and process of higher education blue ribbon commissions that influence their effectiveness were studied. Blue ribbon commissions, which have been used as one type of statewide planning strategy, are defined here as commissions with (1) a predetermined life span; (2) authority established by the legislature and/or the…

A Comparison of Teachers' Perceptions of Principal Effectiveness in National Blue Ribbon Schools and Matched Sets of Selected Non-Blue Ribbon Schools in Pennsylvania

ERIC Educational Resources Information Center

Giffing, Ryan Robert

2010-01-01

With a focus on leadership, this study examines the leadership characteristics of principals in schools that are recognized as National Blue Ribbon Schools by the United States Department of Education. This mixed methodology study utilizes the causal comparative method to compare what teachers consider to be effective leadership characteristics of…

What Professional and Personal Strategies Do Successful Principals Possess to Cultivate a School Culture That Promotes Academic Success in a Blue Ribbon School

ERIC Educational Resources Information Center

McKinney, Carlos LaTeetha

2012-01-01

Principals who are presiding over schools that have received a blue ribbon certification have evidently used specific professional and personal strategies, as well as behaviors, to enhance the academic and social culture of their schools. The current study examined Mississippi Gulf Coast Schools that received blue ribbon status in the last six…

Blue Ribbon Panel Report-BRP-Cancer Moonshot

Cancer.gov

The Blue Ribbon Panel Report outlines 10 recommendations to accelerate progress against cancer. The panel was established to ensure that the Cancer Moonshot's approaches are grounded in the best science.

Twelve Schools That Succeed.

ERIC Educational Resources Information Center

Horenstein, Mary Ann

This booklet describes 12 Blue Ribbon secondary schools chosen during the 1991 federal recognition program. Representing a cross-section of America, these schools are characterized by a clear vision; empowered, hard-working teachers; a school environment that supports learning; use of local resources; and programs other than classroom learning.…

Blue Ribbon Panel Report

Cancer.gov

An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7.

Report of the Governor's Blue Ribbon Transportation Task Force

DOT National Transportation Integrated Search

1982-12-01

Governor Ray appointed the Blue Ribbon Transportation Task Force to provide guidance concerning specific steps that can be taken to: achieve maximum efficiency in the utilization of transportation resources; preserve essential transportation services...

Blue Ribbon Commission Tour of Hanford Site

ScienceCinema

Paul Saueressig

2017-12-09

The Blue Ribbon Commission on America's Nuclear Future toured the Department of Energy's Hanford Site on July 14, 2010. Commission members, invited guests, and members of the public visited facilities that store high-level, radioactive waste.

Achieving Clean Air and Clean Water: The Report of the Blue Ribbon Panel on Oxygenates in Gasoline

EPA Pesticide Factsheets

The Blue Ribbon Panel's report consists of five issue summaries: water contamination; air quality benefits; prevention; treatment and remediation; fuel supply and cost; and comparing the fuel additives.

The Blue Ribbon Panel on Oxygenates in Gasoline : executive summary and recommendations.

DOT National Transportation Integrated Search

1999-07-27

In November, 1998, U.S. EPA Administrator Carol M. Browner appointed a Blue Ribbon : Panel to investigate the air quality benefits and water quality concerns associated with : oxygenates in gasoline, and to provide independent advice and recommendati...

The Blue Ribbon: An American Way of Life.

ERIC Educational Resources Information Center

Weber, Joseph A.; McCullers, John C.

1986-01-01

The notion that blue ribbons serve to increase the motivation and performance of 4-H youth may not always be true. Studies of the effect of such incentives give cause for reevaluation of the present reward structure in light of current 4-H philosophy. (SK)

75 FR 66766 - NIAID Blue Ribbon Panel Meeting on Adjuvant Discovery and Development

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-29

..., identifies gaps in knowledge and capabilities, and defines NIAID's goals for the continued discovery... DEPARTMENT OF HEALTH AND HUMAN SERVICES NIAID Blue Ribbon Panel Meeting on Adjuvant Discovery and... agenda for the discovery, development and clinical evaluation of adjuvants for use with preventive...

Commissions, Reports, Reforms, and Educational Policy.

ERIC Educational Resources Information Center

Ginsberg, Rick, Ed.; Plank, David N., Ed.

"Blue-ribbon" commissions are an increasingly common feature of the American political landscape. This book examines the roles that blue-ribbon commissions and their reports have played in educational policymaking. The book begins with a foreword by Paul E. Peterson and an introductory chapter, "Commissions and Change" by Rick Ginsberg and David…

76 FR 1608 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-11

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting. SUMMARY: This notice announces an open...- 0544; e-mail [email protected]nuclear.energy.gov . Additional information may also be available at http...

75 FR 35000 - Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of Open Meeting. SUMMARY: This... Avenue, SW., Washington DC 20585, e-mail to [email protected]nuclear.energy.gov , or post comments on the...

75 FR 67958 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-04

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Office of Nuclear...-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional information... and nuclear waste. The Commission is scheduled to submit a draft report to the Secretary of Energy in...

76 FR 2891 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-18

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Office of Nuclear...; telephone (202) 586-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional.... Department of Energy, 1000 Independence Avenue, SW., Washington, DC 20585, e-mail to [email protected]nuclear...

75 FR 25850 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-10

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting. SUMMARY: This notice announces an open...-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional information may...

75 FR 43518 - Blue Ribbon Commission on America's Nuclear Future, Transportation and Storage Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Transportation and Storage Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open...-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional information may...

75 FR 10791 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting. SUMMARY: This notice announces an open...; telephone (202) 586-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov...

75 FR 51247 - Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting. SUMMARY: This...; telephone (202) 586-4243 or facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional...

75 FR 13757 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-23

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting correction. On March 9, 2010, the...., Washington DC 20585, or e-mail [email protected]nuclear.energy.gov . Additionally, every effort is being made to...

75 FR 36648 - Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Disposal Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of open meeting correction. On June 21, 2010, the Department of Energy published a notice announcing an open meeting of the Disposal...

Practices of Blue Ribbon Catholic Schools, 2001.

ERIC Educational Resources Information Center

Kealey, Robert J., Comp.

For almost 20 years, the U.S. Department of Education has invited schools to seek the Blue Ribbon School Award. A large number of Catholic schools have received this award. For this publication, the Department of Elementary Schools Executive Committee requested principals of awarded schools to write a short article on an exemplary school program…

Convergence, Competition, Cooperation: The Report of the Governor's Blue Ribbon Telecommunications Infrastructure Task Force. Volume One.

ERIC Educational Resources Information Center

Wisconsin Governor's Office, Madison.

This report by the Blue Ribbon Task Force on Wisconsin's Telecommunications Infrastructure considers infrastructure to be the common network that connects individual residences, businesses, and agencies, rather than the individual systems and equipment themselves. The task force recognizes that advances in telecommunications technologies and…

75 FR 51025 - Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technology Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle... meeting. SUMMARY: This notice announces an open meeting of the Reactor and Fuel Cycle Technology (RFCT... back end of the nuclear fuel cycle. The Commission will provide advice and make recommendations on...

75 FR 36648 - Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technologies Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technologies Subcommittee AGENCY: Office of Nuclear Energy, DOE. ACTION: Notice of open meeting correction. On June 21, 2010, the Department of Energy published a notice announcing an open meeting of the Reactor...

75 FR 35001 - Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technologies Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technologies Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of Open... facsimile (202) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional information may also be...

75 FR 61139 - Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technology Subcommittee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-04

... DEPARTMENT OF ENERGY Blue Ribbon Commission on America's Nuclear Future, Reactor and Fuel Cycle Technology Subcommittee AGENCY: Department of Energy, Office of Nuclear Energy. ACTION: Notice of Open...) 586- 0544; e-mail [email protected]nuclear.energy.gov . Additional information will be available at http...

A Lasting Legacy: Recommendations of the New England Governors Blue Ribbon Commission on Land Conservation

ERIC Educational Resources Information Center

Barringer, Richard

2010-01-01

In September 2008, New England's governors established a blue-ribbon Commission on Land Conservation to identify the most urgent land-conservation issues facing New England today and provide recommendations to the governors in September 2009. New England faces profound threats to its land and natural-resource base. As the nation urbanizes further,…

Creating a Continuum of Excellence: A U.S. Blue Ribbon Schools of Excellence Conference Proceedings (Coral Gables, Florida, 1999).

ERIC Educational Resources Information Center

Nalley, Donna

These proceedings of the conference "Creating a Continuum of Excellence: A U.S. Blue Ribbon Schools of Excellence Conference," produced by SERVE in collaboration with Nova Southeastern University was held in Coral Gables, Florida, 1999. It lists keynote speakers, action planning meetings, think tanks, and titles of exemplary practice sessions, as…

Partnering for the Clinical Preparation of Education Specialists

ERIC Educational Resources Information Center

Robinson, Suzanne; Cote, Debra

2016-01-01

NCATE's (2010) "Report of the Blue Ribbon Panel" calls for a shift toward clinical preparation and partnerships as a means of adequately preparing new teachers for the 21st century classroom. Looking at special education teacher preparation, there exist few model programs that have paved the road for others in implementing new clinical…

Distinguished Practices of Distinguished Schools.

ERIC Educational Resources Information Center

Council for American Private Education, Germantown, MD.

The Blue Ribbon Schools (BRS) program was designed in 1982 with three purposes in mind: to identify and recognize outstanding schools; to provide schools a tool and criteria for self-assessment and improvement; and to facilitate the sharing of best practices among schools. This book presents profiles and best practices of 12 elementary, 2 middle,…

Coordination, Cooperation, and Collaboration between FIA and NRI

Treesearch

Raymond L. Czaplewski; James Rack; Veronica C. Lessard; David F. Heinzen; Susan Ploetz; Thomas L. Schmidt; Earl C. Leatherberry

2005-01-01

The USDA Forest Service conducts a detailed survey of the Nation's forests through the Forest Inventory and Analysis (FIA) program. The USDA Natural Resources Service conducts an entirely separate survey, the National Resources Inventory (NRI), to monitor status and trends in the Nation's soil and other natural resources. Blue Ribbon Panels for both FIA and...

Preparing the Next Generation of Teacher Educators: The Role of Practitioner Inquiry

ERIC Educational Resources Information Center

Jacobs, Jennifer; Yendol-Hoppey, Diane; Dana, Nancy Fichtman

2015-01-01

Although the NCATE Blue Ribbon Panel Report challenges those responsible for teacher preparation to design clinically rich programs, there is little discussion about preparing teacher educators to actualize these innovations. This study explored how practitioner inquiry could serve as a mechanism to facilitate the development of the next…

A Quantitative Examination of the Educational Technology Characteristics of Ohio Schools and Their Blue Ribbon Status

ERIC Educational Resources Information Center

Goon, Dean A.

2012-01-01

The purpose of this study was to analyze data from Ohio schools and the frequency of use of educational technology, a teacher's comfort level using technology, and a teacher's beliefs about the effect of educational technology on teaching and learning based upon the school's Blue Ribbon award status. The study used an ex-post facto, quantitative…

Best Practices of National Blue Ribbon Schools: A Collection from Distinguished Catholic Schools

ERIC Educational Resources Information Center

Jones, Annette; Gallagher, Gabrielle

2017-01-01

Of the 50 private schools recognized each year as National Blue Ribbon Schools, 75 percent of them are Catholic schools. These are the stories of many of the award-winning schools and the best practices that define them. Learn marketing strategies that can highlight a school's academic success as well as its strong faith formation and make it a…

The Impact an Integrated Workforce of a Rural Southwestern School District Has in the Making of a Blue Ribbon School

ERIC Educational Resources Information Center

Goolsby, Annie J.

2013-01-01

This study utilized a contemporary approach to qualitative research, the descriptive survey design, to discover whether a diverse workforce was a major influence in producing a rural Blue Ribbon School. The population represented the school systems of a county located in the West South Central region of the United States. In this study, the terms…

Changes in Residents' Self-Efficacy Beliefs in a Clinically Rich Graduate Teacher Education Program

ERIC Educational Resources Information Center

Reynolds, Heather M.; Wagle, A. Tina; Mahar, Donna; Yannuzzi, Leigh; Tramonte, Barbara; King, Joseph

2016-01-01

Increasing the clinical preparation of teachers in the United States to meet greater rigor in K-12 education has become a goal of institutions of higher education, especially since the publication of the National Council for the Accreditation of Teacher Education Blue Ribbon Panel Report on Clinical Practice. Using a theoretical framework grounded…

Symposium on Direct Instruction: The Follow Through Data Show That Some Programs Work Better Than Others.

ERIC Educational Resources Information Center

Becker, Wesley C.

The Abt Associates' final report on the Follow-Through Planned Variation Experiment is defended against the critique published by a blue ribbon panel funded by the Ford Foundation. In contrast to the conclusions drawn by House, Glass, McLean, and Walker that Follow Through showed no "winners" or "losers", the National…

Preservice Special Education Teachers' Perceptions of What Influences Their Appropriation of University Coursework Knowledge and Skills during the Clinical Teaching Internship Experience

ERIC Educational Resources Information Center

McElwee, Christine B.

2015-01-01

The clinical internship experience for preservice interns has been described as one of the most important components of teacher preparation programs. The National Council for Accreditation of Teacher Education's (NCATE) "Blue Ribbon Panel Report on Clinical Preparation and Partnerships for Improved Student Learning" suggests that teacher…

New Era for Libraries. A Report from the Iowa Blue Ribbon Task Force on Libraries.

ERIC Educational Resources Information Center

Iowa State Dept. of Cultural Affairs, Des Moines. State Library.

The Director of the Department of Cultural Affairs appointed a task force, to be chaired by the State Librarian of Iowa, to evaluate technologies available for libraries and potential uses for the technologies deemed valuable; discuss problems from the viewpoint of the library user in the establishment of cooperative programs; and develop a…

The Evolution of the Advanced Attack Helicopter

DTIC Science & Technology

1975-06-06

p. 18. C. V. Glines (LTC, USA), "De Bothezat’s Flying Octopus ," Airman, Vol VI, No. I (January, 1962), 43. 29Ross, p. 58. 20 in his own right, being...AIR MOBILE OPIRATIONS, A Report for the Blue Ribbon Defense Panel by COL Jay D. Vanderpool, USA, Ret. (February 1970), 29. F. IY 70A Observation...not produce significant quantitative progress. -Attack Helicopters The Key to Army Air Mobile Operations, A Report for the Blue Ribbon Defense Panel by

Blue Ribbon Child Care Food and Nutrition Skill Series: Idaho Child Nutrition Programs. Second Edition.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise.

Noting that children have different appetites and adjust their food intake on a meal by meal basis, this self study guide presents ideas to help home child care providers meet the nutritional needs of the children in their care. The guide is to be used by individuals and small groups of adults working with infants and children. The guide's eight…

Report to the President and the Secretary of Defense on the Department of Defense by the Blue Ribbon Defense Panel

DTIC Science & Technology

1970-07-01

scientific and industrial community. (3) The Defense procurement policies and practices, par•icularly as they relate to costs , time and quality. (4) Such...procurements. Military hardware development programs continue to be plagued by the now familiar symptoms of trouble: (I ) Major cost growths or overruns...and this uncertainty makes it inevitable that some degree of cost growth, delays and short-falls in desired perfornmance will occur in sonme programs

The Time Needed to Implement the Blue Ribbon Commission Recommendation on Interim Storage - 13124

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voegele, Michael D.; Vieth, Donald

2013-07-01

The report of the Blue Ribbon Commission on America's Nuclear Future [1] makes a number of important recommendations to be considered if Congress elects to redirect U.S. high-level radioactive waste disposal policy. Setting aside for the purposes of this discussion any issues related to political forces leading to stopping progress on the Yucca Mountain project and driving the creation of the Commission, an important recommendation of the Commission was to institute prompt efforts to develop one or more consolidated storage facilities. The Blue Ribbon Commission noted that this recommended strategy for future storage and disposal facilities and operations should bemore » implemented regardless of what happens with Yucca Mountain. It is too easy, however, to focus on interim storage as an alternative to geologic disposal. The Blue Ribbon Commission report does not go far enough in addressing the magnitude of the contentious problems associated with reopening the issues of relative authorities of the states and federal government with which Congress wrestled in crafting the Nuclear Waste Policy Act [2]. The Blue Ribbon Commission recommendation for prompt adoption of an interim storage program does not appear to be fully informed about the actions that must be taken, the relative cost of the effort, or the realistic time line that would be involved. In essence, the recommendation leaves to others the details of the systems engineering analyses needed to understand the nature and details of all the operations required to reach an operational interim storage facility without derailing forever the true end goal of geologic disposal. The material presented identifies a number of impediments that must be overcome before the country could develop a centralized federal interim storage facility. In summary, and in the order presented, they are: 1. Change the law, HJR 87, PL 107-200, designating Yucca Mountain for the development of a repository. 2. Bring new nuclear waste legislation to the floor of the Senate, overcoming existing House support for Yucca Mountain; 3. Change the longstanding focus of Congress from disposal to storage; 4. Change the funding concepts embodied in the Nuclear Waste Policy Act to allow the Nuclear Waste fund to be used to pay for interim storage; 5. Reverse the Congressional policy not to give states or tribes veto or consent authority, and to reserve to Congress the authority to override a state or tribal disapproval; 6. Promulgate interim storage facility siting regulations to reflect the new policies after such changes to policy and law; 7. Complete already underway changes to storage and transportation regulations, possibly incorporating changes to reflect changes to waste disposal law; 8. Promulgate new repository siting regulations if the interim storage facility is to support repository development; 9. Identify volunteer sites, negotiate agreements, and get Congressional approval for negotiated benefits packages; 10. Design, License and develop the interim storage facility. The time required to accomplish these ten items depends on many factors. The estimate developed assumes that certain of the items must be completed before other items are started; given past criticisms of the current program, such an assumption appears appropriate. Estimated times for completion of individual items are based on historical precedent. (authors)« less

38 CFR 21.9700 - Yellow Ribbon Program.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Yellow Ribbon Program. 21... Ribbon Program. (a) Establishment. The “Yellow Ribbon G.I. Education Enhancement Program”, known as the “Yellow Ribbon Program,” permits an institution of higher learning (IHL), at the IHL's option, to enter...

38 CFR 21.9700 - Yellow Ribbon Program.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Yellow Ribbon Program. 21... Ribbon Program. (a) Establishment. The “Yellow Ribbon G.I. Education Enhancement Program”, known as the “Yellow Ribbon Program,” permits an institution of higher learning (IHL), at the IHL's option, to enter...

38 CFR 21.9700 - Yellow Ribbon Program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Yellow Ribbon Program. 21... Ribbon Program. (a) Establishment. The “Yellow Ribbon G.I. Education Enhancement Program”, known as the “Yellow Ribbon Program,” permits an institution of higher learning (IHL), at the IHL's option, to enter...

38 CFR 21.9700 - Yellow Ribbon Program.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Yellow Ribbon Program. 21... Ribbon Program. (a) Establishment. The “Yellow Ribbon G.I. Education Enhancement Program”, known as the “Yellow Ribbon Program,” permits an institution of higher learning (IHL), at the IHL's option, to enter...

38 CFR 21.9700 - Yellow Ribbon Program.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Yellow Ribbon Program. 21... Ribbon Program. (a) Establishment. The “Yellow Ribbon G.I. Education Enhancement Program”, known as the “Yellow Ribbon Program,” permits an institution of higher learning (IHL), at the IHL's option, to enter...

Can shale safely host US nuclear waste?

USGS Publications Warehouse

Neuzil, C.E.

2013-01-01

"Even as cleanup efforts after Japan’s Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America’s Nuclear Future, 2012].However, abandoning Yucca Mountain could also result in broadening geologic options for hosting America’s nuclear waste. Shales and other argillaceous formations (mudrocks, clays, and similar clay-rich media) have been absent from the U.S. repository program. In contrast, France, Switzerland, and Belgium are now planning repositories in argillaceous formations after extensive research in underground laboratories on the safety and feasibility of such an approach [Blue Ribbon Commission on America’s Nuclear Future, 2012; Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (NAGRA), 2010; Organisme national des déchets radioactifs et des matières fissiles enrichies, 2011]. Other nations, notably Japan, Canada, and the United Kingdom, are studying argillaceous formations or may consider them in their siting programs [Japan Atomic Energy Agency, 2012; Nuclear Waste Management Organization (NWMO), (2011a); Powell et al., 2010]."

Blue Ribbon Committee on Bloodborne Parasitic Diseases.

PubMed

2002-09-01

In summary, the A1 recommendations are related to: developing a network (epidemiologic and demographic aspects); undertaking activities within the network; providing support for parasite research testing; developing new policies, and; preparing a Memorandum to Cabinet for submission by September 1, 2001, for funding from April 2002 over 5 years. The A recommendations deal with sustaining the network and addressing existing needs, including Public and professional education Review of current policies Business plan Development of a contribution program to meet operational needs. The B recommendation(s) will be dealt with by the future Treasury Board submission. The group identified no C recommendations.

UCAR group urges STORM program

NASA Astrophysics Data System (ADS)

Richman, Barbara T.

A blue-ribbon panel of scientists has proposed a decade-long, $1 billion program to improve forecasting operations and research of regional and local hazardous weather. The panel, appointed by the University Corporation for Atmospheric Research (UCAR), believes that the program could reduce the $20-billion annual cost of damage from severe weather by $1 billion per year.The primary aim of the program is to ‘enable weather services, public and private, to observe and predict stormscale weather phenomena— such as squall lines, thunderstorms, flash floods, local heavy snows, or tornadoes—with the accuracy and reliability to protect the public, serve the national economy, and meet defense requirements,’ as explained in the report, The National STORM (Stormscale Operational and Research Meteorology) Program: A Call to Action. Stormscale phenomena also include nonviolent weather: freezing rain, dense ground fog, low-lying clouds that disrupt ground or air traffic, persistent temperature inversions, and strong nocturnal cooling that may produce killing frost.

Moonshot Panel Moving Toward Final Report

Cancer.gov

An NCI Cancer Currents blog from acting NCI Director Dr. Doug Lowy providing an update on the activities of the National Cancer Moonshot Initiative’s Blue Ribbon Panel and its work to develop a final report.

77 FR 4405 - Advisory Committee: National Academic Affiliations Council; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... recommendations of the Blue Ribbon Panel on VA Medical School Affiliations and VHA's present educational portfolio and recent educational innovations; and from the VA Office of General Counsel on government ethics...

Electronic toll collection/electronic screening interoperability pilot project : final report synthesis

DOT National Transportation Integrated Search

2005-12-02

In 1998, ITS America established a Blue Ribbon Panel on electronic commerce to study the convergence of transportation and electronic payment systems. Panel members included senior managers from government, toll agencies, motor carrier industry, and ...

International Space Station (ISS)

NASA Image and Video Library

2001-05-08

This is the insignia for the STS-108 mission, which marked a major milestone in the assembly of the International Space Station (ISS) as the first designated Utilization Flight, UF-1. The crew of Endeavour delivered the Expedition Four crew to ISS and returned the Expedition Three crew to Earth. Endeavour launched with a Multi-Purpose Logistics Module (MPLM) that was berthed to the ISS and unloaded. The MPLM was returned to Endeavour for the trip home and used again on a later flight. The crew patch depicts Endeavour and the ISS in the configuration at the time of arrival and docking. The Station is shown viewed along the direction of flight as seen by the Shuttle crew during their final approach and docking along the X-axis. The three ribbons and stars on the left side of the patch signify the returning Expedition Three crew. The red, white and blue order of the ribbons represents the American commander for that mission. The three ribbons and stars on the right depict the arriving Expedition Four crew. The white, blue, and red order of the Expedition Four ribbon matches the color of the Russian flag and signifies that the commander of Expedition Four is a Russian cosmonaut. Each white star in the center of the patch represents the four Endeavour crew members. The names of the four astronauts who crewed Endeavour are shown along the top border of the patch. The three astronauts and three cosmonauts of the two expedition crews are shown on the chevron at the bottom of the patch.

Adolescent Help-Seeking and the Yellow Ribbon Suicide Prevention Program: An Evaluation

ERIC Educational Resources Information Center

Freedenthal, Stacey

2010-01-01

The Yellow Ribbon Suicide Prevention Program has gained national and international recognition for its school- and community-based activities. After the introduction of Yellow Ribbon to a Denver-area high school, staff and adolescents were surveyed to determine if help-seeking behavior had increased. Using a prepost intervention design, staff at…

Governance: current trends in board education, competencies, and qualifications.

PubMed

Nash, David B; Murphy, Sean Patrick; Mullaney, Anne D

2011-01-01

Hospitals and health system boards have been under enormous pressure to be more accountable. However, there is now an emerging trend of voluntary, mandatory, and payer-driven board education programs. Currently, 13 states have some type of formal, organized board education and development initiative, 10 of which are classified as "director and/ or board certificate" or "certification" programs; the American Hospital Association (through and with its affiliated Center for Healthcare Governance) has issued a Blue Ribbon Panel Report on core competencies. Finally, both Congress and the Securities and Exchange Commission require publicly traded companies to disclose board and director qualifications. This article reviews these emerging trends and posits that these developments are a necessary prerequisite not only for accountability and better governance but also for quality care.

Workshop: Stated Preference: What Do We Know? Where Do We Go? (2000)

EPA Pesticide Factsheets

Two day workshop sponsored by EPA's National Center for Environmental Research (NCER) and National Center for Environmental Economics (NCEE) explored the current state of stated preference research-taking stock of advances since NOAA Blue Ribbon panel.

Attachment 1 : appendices : electronic toll collection/electronic screening interoperability pilot project, supplement to the final report

DOT National Transportation Integrated Search

2005-07-29

In 1998, ITS America established a Blue Ribbon Panel on electronic commerce to study the convergence of transportation and electronic payment systems. Panel members included senior managers from government, toll agencies, motor carrier industry, and ...

Education Matters, November 2008

ERIC Educational Resources Information Center

Beckner, Gary, Ed.

2008-01-01

"Education Matters" is the monthly newsletter of the Association of American Educators (AAE), an organization dedicated to advancing the American teaching profession through personal growth, professional development, teacher advocacy and protection. This issue of the newsletter includes: (1) Peeking Behind the Blue Ribbon (Vicki E.…

77 FR 18271 - Notice of Sunshine Act Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

.... Affirmation Session (Public Meeting) (Tentative) a. FirstEnergy Nuclear Operating Co. (Davis-Besse Nuclear... NUCLEAR REGULATORY COMMISSION [NRC-2012-0002] Notice of Sunshine Act Meeting DATE: Weeks of March....m. Briefing on the Final Report of the Blue Ribbon Commission on America's Nuclear Future (Public...

Executive Summary From the National Strength and Conditioning Association's Second Blue Ribbon Panel on Military Physical Readiness: Military Physical Performance Testing.

PubMed

Nindl, Bradley C; Alvar, Brent A; R Dudley, Jason; Favre, Mike W; Martin, Gerard J; Sharp, Marilyn A; Warr, Brad J; Stephenson, Mark D; Kraemer, William J

2015-11-01

The National Strength and Conditioning Association's tactical strength and conditioning program sponsored the second Blue Ribbon Panel on military physical readiness: military physical performance testing, April 18-19, 2013, Norfolk, VA. This meeting brought together a total of 20 subject matter experts (SMEs) from the U.S. Air Force, Army, Marine Corps, Navy, and academia representing practitioners, operators, researchers, and policy advisors to discuss the current state of physical performance testing across the Armed Services. The SME panel initially rated 9 common military tasks (jumping over obstacles, moving with agility, carrying heavy loads, dragging heavy loads, running long distances, moving quickly over short distances, climbing over obstacles, lifting heavy objects, loading equipment) by the degree to which health-related fitness components (e.g., aerobic fitness, muscular strength, muscular endurance, flexibility, and body composition) and skill-related fitness components (e.g., muscular power, agility, balance, coordination, speed, and reaction time) were required to accomplish these tasks. A scale from 1 to 10 (10 being highest) was used. Muscular strength, power, and endurance received the highest rating scores. Panel consensus concluded that (a) selected fitness components (particularly for skill-related fitness components) are currently not being assessed by the military; (b) field-expedient options to measure both health-based and skill-based fitness components are currently available; and (c) 95% of the panel concurred that all services should consider a tier II test focused on both health-related and skill-related fitness components based on occupational, functional, and tactical military performance requirements.

The Blue Ribbon Panel on Depowered and Advanced Airbags — Status Report on Airbag Performance

PubMed Central

Ferguson, Susan A.; Schneider, Lawrence; Segui-Gomez, Maria; Arbogast, Kristy; Augenstein, Jeffrey; Digges, Kennerly H.

2003-01-01

SUMMARY In February 2000, a group of highway safety organizations sent a letter to the Secretary of the U.S. Department of Transportation expressing concern about a possible return to the 30-mph rigid barrier test using unbelted dummies previously required by Federal Motor Vehicle Safety Standard (FMVSS) 208. The letter asked the National Highway Traffic Safety Administration (NHTSA) to expedite data collection of the real-world crash experience of airbag-equipped vehicles certified to the 30-mph sled test using unbelted dummies because of suggestions that depowered airbags may not provide the same level of protection, particularly to larger, unbelted occupants. For the same reason, the letter also recommended that the auto industry commit funding for additional data collection and to establish a panel of experts to evaluate the data. In response, the Alliance of Automobile Manufacturers (Alliance) committed to funding a 3-year program to be managed by an independent third party. A panel of experts consisting of representatives from the highway safety research community, the National Transportation Safety Board, academia, medical institutions, and the insurance industry was established as the Blue Ribbon Panel (BRP) for Evaluation of Depowered and Advanced Airbags and met for the first time in February 2001. The BRP also includes representatives from NHTSA and the automobile industry who participate as observers. The BRP held its first public meeting in April 2003 to provide an update of its activities and to summarize the real-world evidence on the performance of depowered airbags. This AAAM session will provide a brief summary of the public meeting. PMID:12941215

Large area silicon sheet by EFG

NASA Technical Reports Server (NTRS)

Morrison, A. D.; Ravi, K. V.; Rao, C. V. H.; Surek, T.; Bliss, D. F.; Garone, L. C.; Hogencamp, R. W.

1976-01-01

Progress in a program to produce high speed, thin, wide silicon sheets for fabricating 10% efficient solar cells is reported. An EFG ribbon growth system was used to perform growth rate and ribbon thickness experiments. A new, wide ribbon growth system was developed. A theoretical study of stresses in ribbons was also conducted. The EFG ribbons were observed to exhibit a characteristic defect structure which is orientation dependent in the early stages of growth.

Siberian Ribbons

NASA Image and Video Library

2017-12-08

Siberian Ribbons - June 15th, 2005 Description: Vivid colors and bizarre shapes come together in an image that could be an imaginative illustration for a fantasy story. This labyrinth of exotic features is present along the edge of Russia's Chaunskaya Bay (vivid blue half circle) in northeastern Siberia. Two major rivers, the Chaun and Palyavaam, flow into the bay, which in turn opens into the Arctic Ocean. Ribbon lakes and bogs are present throughout the area, created by depressions left by receding glaciers. Credit: USGS/NASA/Landsat 5 To learn more about the Landsat satellite go to: landsat.gsfc.nasa.gov/ NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

NCATE's Blue Ribbon Panel Report and NAPDS: Working Together

ERIC Educational Resources Information Center

Van Scoy, Irma J.

2012-01-01

An expert panel including representatives from schools/districts, teacher education, and professional education associations was convened by the National Council for the Accreditation of Teacher Education (NCATE) to make recommendations regarding clinical preparation in teacher education. This article presents an analysis of how the ten design…

No Blue Ribbon

ERIC Educational Resources Information Center

Wilsey, Matthew; Kloser, Matthew

2015-01-01

Imagine middle and high school science classes without a science fair. Participation in science fairs is declining (Harmon 2011), a trend that some teachers, parents, and students find disturbing. The authors opine that the decline in science fairs calls for critically reviewing the potential disconnect between the aims and outcomes of science…

Pablo Cano--"The Blue Ribbon": The Art of Appropriation

ERIC Educational Resources Information Center

Sickler-Voigt, Debrah C.

2011-01-01

For centuries people from around the world have celebrated storytelling and puppetry for their educational and social functions. In the comprehensive curriculum, storytelling combined with puppet performances enriches the classroom experience by providing students with opportunities to engage in open dialogue, creativity, and structured play.…

3 CFR - Blue Ribbon Commission on America's Nuclear Future

Code of Federal Regulations, 2011 CFR

2011-01-01

... America's Nuclear Future Memorandum for the Secretary of Energy Expanding our Nation's capacity to generate clean nuclear energy is crucial to our ability to combat climate change, enhance energy security... safe, secure, and responsible use of nuclear energy. These efforts are critical to accomplishing many...

The New DOD Instruction 5000.02: An Analysis of the Efficiencies to be Gained

DTIC Science & Technology

2015-06-01

IT, and Information Systems • Post Implementation Review (PIR) • DOD Enterprise Architecture requirement • Cybersecurity Strategy for all IT... dam /rand/pubs/occasional_papers/2010/RAND_OP3 08.pdf President’s Blue Ribbon Commission on Defense Management. (1986). A quest for excellence, final

From Chaos to Consistency

ERIC Educational Resources Information Center

McCloud, Susan

2005-01-01

The US Department of Education designated T. C. Cherry Elementary School in Bowling Green, Kentucky, as a Blue Ribbon School, an honor awarded to only few schools across the nation. The same became possible because they changed the culture of the school from rowdy to calm, from irresponsible to responsible, from noncooperative to cooperative, from…

75 FR 70971 - Special Medical Advisory Group; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-19

... DEPARTMENT OF VETERANS AFFAIRS Special Medical Advisory Group; Notice of Meeting The Department of... Special Medical Advisory Group will meet on December 1, 2010, in Room 830 at VA Central Office, 810... on the Blue Ribbon Panel on VA-Medical School Affiliations Report. Any member of the public wishing...

Advancing and Sustaining a Clinical Teacher Preparation Partnership: An Exploratory Qualitative Case Study

ERIC Educational Resources Information Center

Garrido, Melissa Downey

2012-01-01

The national call to "turn [teacher education] upside down" (National Council for Accreditation of Teacher Education, Report of the Blue Ribbon Panel on Clinical Preparation and Partnerships for Improved Student Learning [NCATE], 2010, p. ii) and states' subsequent commitments to pilot recommendations necessitates study of successful…

76 FR 4646 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-26

.... ADDRESSES: Navy Shipyard, 1333 Isaac Hull Avenue, SE., Washington, DC 20376. FOR FURTHER INFORMATION CONTACT... spent nuclear fuel and nuclear waste. The Commission is scheduled to submit a draft report to the..., high-level waste, and materials derived from nuclear activities.'' In support of that effort, the...

Campus Cyberinfrastructure: A Crucial Enabler for Science

ERIC Educational Resources Information Center

Freeman, Peter A.; Almes, Guy T.

2005-01-01

Driven by the needs of college/university researchers and guided by a blue-ribbon advisory panel chaired by Daniel E. Atkins, the National Science Foundation (NSF) has initiated a broad, multi-directorate activity to create modern cyberinfrastructure and to apply it to transforming the effectiveness of the scientific research enterprise in higher…

75 FR 5485 - Blue Ribbon Commission on America's Nuclear Future

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... Commission on America's Nuclear Future Memorandum for the Secretary of Energy Expanding our Nation's capacity to generate clean nuclear energy is crucial to our ability to combat climate change, enhance energy... the safe, secure, and responsible use of nuclear energy. These efforts are critical to accomplishing...

DoD Yellow Ribbon Program For Reintegration

Science.gov Websites

their families get the support and care they need. VIDEO Video Link Yellow Ribbon Program Eases Post Reintegration Program will help them resolve Velazquez' No. 1 post-deployment challenge: finding a civilian job reintegration event regarding post-traumatic stress: "I need your help." Story Program Fills Gap for

Ribbon cutting opens new ELV offices

NASA Technical Reports Server (NTRS)

2000-01-01

Bobby Bruckner, manager, ELV and Payload Carrier Programs, speaks at the ribbon-cutting ceremony of the E&O Building at KSC. Home for NASA's unmanned missions since 1964, the building has been renovated to house the Expendable Launch Vehicle Program.

A study to improve the mechanical properties of silicon carbide ribbon fibers

NASA Technical Reports Server (NTRS)

Debolt, H. E.; Robey, R. J.

1976-01-01

Preliminary deposition studies of SiC ribbon on a carbon ribbon substrate showed that the dominant strength limiting flaws were at the substrate surface. Procedures for making the carbon ribbon substrate from polyimide film were improved, providing lengths up to 450 meters (1,500 ft.) of flat carbon ribbon substrate 1,900 microns (75 mils) wide by 25 microns (1 mil) thick. The flaws on the carbon ribbon were smaller and less frequent than on carbon ribbon used earlier. SiC ribbon made using the improved substrate, including a layer of pyrolytic graphite to reduce further the severity of substrate surface flaws, showed strength levels up to the 2,068 MPa (300 Ksi) target of the program, with average strength levels over 1,700 MPa (250 Ksi) with coefficient of variation as low as 10% for some runs.

77 FR 23751 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-20

..., Clarissa C., Library--Blue Ribbon News Building, (Davenport MRA) 528 Brady St., Davenport, 83002415 Lend-A-Hand Club, (Davenport MRA) 105 S. Main St., Davenport, 84001459 Petersen's, J. H. C., Sons Wholesale Building, (Davenport MRA) 122- 124 W. River Dr., Davenport, 83002484 Schauder Hotel, (Davenport MRA) 126 W...

Biological and Catalytic Conversion of Sugars and Lignin | Bioenergy | NREL

Science.gov Websites

strings and ribbons twisted on themselves: lilac is labeled "LPMO", red is labeled "Family 5", blue is labeled "Family 6", green is labeled "Family 7", purple is labeled "Family 12", and yellow is labeled "Family 45". Two side-by-side images. The

Missouri Extension Study Commission. Report to the Governor and General Assembly.

ERIC Educational Resources Information Center

Missouri State Extension Study Commission, Jefferson City.

A report on the Missouri Extension Study Commission's (a blue ribbon commission) review of the scope, organization, management, and funding of extension activities conducted by Missouri colleges and universities is presented. Based on information obtained from public hearings and studies, 10 general recommendations are offered that pertain to:…

Panel Finds Few Learning Benefits in High-Stakes Exams

ERIC Educational Resources Information Center

Sparks, Sarah D.

2011-01-01

As Congress debates how to structure the next iteration of federal school accountability, a new national study has raised serious concerns about the effectiveness of test-based incentives to improve education. A blue-ribbon committee of the National Academies' National Research Council undertook a nearly decade-long study of test-based incentive…

Miles to Go: Mississippi. Pre-Kindergarten--Time to Begin

ERIC Educational Resources Information Center

Suitts, Steve

2010-01-01

This report by the Southern Education Foundation (SEF) finds that high-quality pre-kindergarten (Pre-K) is the "first, essential step towards building the educated workforce that will enable a better economic future for Mississippi." The report calls on Mississippi leaders to establish a blue-ribbon, bipartisan commission to develop a…

Commission on the Future of Florida's Public Universities.

ERIC Educational Resources Information Center

Commission on the Future of Florida's Public Universities, Tallahassee.

A 1977 review is presented of Florida's State University System, which was conducted by the Commission on the Future of Florida's Public Universities--a blue ribbon commission. The current status of the system and some indications of the importance of high quality universities to Florida's future are considered, and recommendations for improving…

Blue Ribbon Web Sites Contest Winners.

ERIC Educational Resources Information Center

Southworth, Samuel A.

2001-01-01

Presents a collection of prize-winning Web sites created by K-8 teachers nationwide. Some of the unique features of the Web sites include an online student-written newspaper; a sing-along section; a chronicle of the past 3 years of classes to see how the classes have evolved; and student art and writing projects. (SM)

75 FR 2549 - Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a Meeting of the NIH Blue Ribbon... Coordinator, Office of Biotechnology Activities, Office of Science Policy, Office of the Director, National...

75 FR 15713 - Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-30

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a Meeting of the NIH Blue Ribbon... Lewallen, Advisory Committee Coordinator, Office of Biotechnology Activities, Office of Science Policy...

75 FR 54640 - Notice of a Meeting of a Working Group of the NIH Blue Ribbon Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

..., contact Ms. Kelly Fennington, Senior Health Policy Analyst, Office of Biotechnology Activities, Office of Science Policy, Office of the Director, National Institutes of Health, 6705 Rockledge Drive, Room 750...: September 1, 2010. Amy P. Patterson, Acting Director, Office of Science Policy, National Institutes of...

76 FR 61719 - Notice of a meeting of a working group of the NIH Blue Ribbon Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-05

... concerning this meeting, contact Ms. Kelly Fennington, Senior Health Policy Analyst, Office of Biotechnology Activities, Office of Science Policy, Office of the Director, National Institutes of Health, 6705 Rockledge...: September 27, 2011. Amy P. Patterson, Director, Office of Science Policy, National Institutes of Health. [FR...

Seeking a Justice Reform Review

ERIC Educational Resources Information Center

Dervarics, Charles

2010-01-01

This article reports on the legislation proposed by Senator Jim Webb which authorizes a blue-ribbon commission of experts who would undertake an 18-month review of the nation's criminal justice system, including issues such as the disproportionate share of minorities--particularly African-Americans--in the U.S. prisons. Webb said that the U.S. has…

Marrying Citizens and Educators in Decision Making

ERIC Educational Resources Information Center

Leighninger, Matt

2005-01-01

The growing attraction between citizens and educators can form the basis of a fruitful school-community relationship. This new way of connecting, in which large numbers of people meet regularly to talk about school issues and find solutions, goes far beyond blue-ribbon commissions and school-business partnerships. To make the marriage last,…

Policy Meets Practice: Districts feel the impact of State Regulations

ERIC Educational Resources Information Center

Hazi, Helen M.; Arredondo Rucinski, Daisy

2014-01-01

Stewart Thorson, principal of New Century Technology High School in Huntsville, Alabama, develops plans for his school's professional learning in an environment restricted by state regulations. In Alabama's Title I and low socioeconomic status schools and through initiatives such as Blue Ribbon Schools and the State Department of Education's Plan…

Yucca Mountain nuclear waste repository prompts heated congressional hearing

NASA Astrophysics Data System (ADS)

Showstack, Randy

2011-11-01

Although the final report of the Blue Ribbon Commission on America's Nuclear Future is not expected until January 2012, the tentative conclusions of the commission's draft report were dissected during a recent joint hearing by two subcommittees of the House of Representatives' Committee on Science, Space, and Technology. Among the more heated issues debated at the hearing was the fate of the stalled Yucca Mountain nuclear waste repository in Nevada. The Blue Ribbon Commission's (BRC) draft report includes recommendations for managing nuclear waste and for developing one or more permanent deep geological repositories and interim storage facilities, but the report does not address the future of Yucca Mountain. The BRC charter indicates that the commission is to "conduct a comprehensive review of policies for managing the back end of the nuclear fuel cycle." However, the draft report states that the commission was not asked to consider, and therefore did not address, several key issues. "We have not rendered an opinion on the suitability of the Yucca Mountain site or on the request to withdraw the license application for Yucca Mountain," the draft report states.

Committee to evaluate Sandia`s risk expertise: Final report. Volume 1: Presentations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dudley, E.C.

1998-05-01

On July 1--2, 1997, Sandia National Laboratories hosted the External Committee to Evaluate Sandia`s Risk Expertise. Under the auspices of SIISRS (Sandia`s International Institute for Systematic Risk Studies), Sandia assembled a blue-ribbon panel of experts in the field of risk management to assess their risk programs labs-wide. Panelists were chosen not only for their own expertise, but also for their ability to add balance to the panel as a whole. Presentations were made to the committee on the risk activities at Sandia. In addition, a tour of Sandia`s research and development programs in support of the US Nuclear Regulatory Commissionmore » was arranged. The panel attended a poster session featuring eight presentations and demonstrations for selected projects. Overviews and viewgraphs from the presentations are included in Volume 1 of this report. Presentations are related to weapons, nuclear power plants, transportation systems, architectural surety, environmental programs, and information systems.« less

Stress analysis of ribbon parachutes

NASA Technical Reports Server (NTRS)

Reynolds, D. T.; Mullins, W. M.

1975-01-01

An analytical method has been developed for determining the internal load distribution for ribbon parachutes subjected to known riser and aerodynamic forces. Finite elements with non-linear elastic properties represent the parachute structure. This method is an extension of the analysis previously developed by the authors and implemented in the digital computer program CANO. The present analysis accounts for the effect of vertical ribbons in the solution for canopy shape and stress distribution. Parametric results are presented which relate the canopy stress distribution to such factors as vertical ribbon strength, number of gores, and gore shape in a ribbon parachute.

The Context of Higher Education Reform in the United States

ERIC Educational Resources Information Center

Heller, Donald E.

2009-01-01

Higher education in the United States has received much scrutiny in the recent past from the federal and state governments, the press and the general public. In response to this scrutiny, a number of blue ribbon panels have been formed to examine how effectively higher education is serving American society. In this article, I analyse the…

Higher Education's "Accountability" Imperative: How the University System of Maryland Responded

ERIC Educational Resources Information Center

Kirwan, William E.

2007-01-01

A crucial national dialogue is under way about higher education and its role in securing America's future. Last fall, a blue-ribbon panel on higher education, established by Secretary of Education Margaret Spellings, issued a report expressing concerns that the United States could be losing its status as the world leader in postsecondary…

Capturing Your Students' Attention is Easier with this Month's Software Selections. Blue Ribbon Reviews

ERIC Educational Resources Information Center

Lindroth, Linda

2005-01-01

This article describes new presentation tools and game shows that can make the classroom into a learning stage. RM Easiteach Studio, a presentation software from RM Educational Software, provides teaching tools for use on any interactive whiteboard. Classroom Jeopardy[R] from Educational Insights includes a scoreboard/base control unit, three…

An Evaluation of the 1989 Restructuring of the Navy Medical Department from the Perspective of Financial Managers

DTIC Science & Technology

1991-12-01

Department Managing Organizational Change Department of the Navy Medical Blue Ribbon Panal of 1988-89 19 ABSTRACT (continue on reverse if necessary and...in this section was previously published in the article " Managing Organizational Change within the Navy Medical Department" by Lt John C. Espie, Navy

Design of the Army Chargeback and Cost Accounting System. Study Recommendations Report (Final Design and Implementation Plan),

DTIC Science & Technology

1987-08-07

0MB, and Congress. Vance recommands that the marketing strategy consist of meetings to attend, presentations to give, input to request, briefings to...6.2.3.1.6 Blue Ribbon Panel. Vance recommends that as part of the marketing strategy , the Army convene a panel of senior corporate officials and

75 FR 10293 - Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities; Office of Science Policy; Office of the Director; Notice of a Meeting of the NIH Blue Ribbon... Activities, Office of Science Policy, Office of the Director, National Institutes of Health, 6705 Rockledge...

From Desktop to Teraflop: Exploiting the U.S. Lead in High Performance Computing. NSF Blue Ribbon Panel on High Performance Computing.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC.

This report addresses an opportunity to accelerate progress in virtually every branch of science and engineering concurrently, while also boosting the American economy as business firms also learn to exploit these new capabilities. The successful rapid advancement in both science and technology creates its own challenges, four of which are…

From Threshers to Thrashers: In Montana, 4-H Takes a Modern Spin To Engage "Blue-Ribbon Kids."

ERIC Educational Resources Information Center

Linik, Joyce Riha

2002-01-01

A 4-H skateboard club in Bozeman, Montana offers kids community service and educational opportunities as well as something to do after school. Adult and college-student volunteers teach a skateboarding curriculum and help kids fix boards and design ramps. Club members have learned public speaking, fundraising, city planning, and civic involvement…

A Comparison of Mission Statements of National Blue Ribbon Schools and Unacceptable Texas High Schools

ERIC Educational Resources Information Center

Perfetto, John Charles; Holland, Glenda; Davis, Rebecca; Fedynich, La Vonne

2013-01-01

This study was conducted to determine the themes present in the context of high schools, to determine any significant differences in themes for high and low performing high schools, and to determine if significant differences were present for the same sample of high schools based on school size. An analysis of the content of mission statements…

Charting the Future of US Higher Education: A Look at the Spellings Report Ten Years Later

ERIC Educational Resources Information Center

Neuman, W. Russell

2017-01-01

September marked the tenth anniversary of the release of "A Test of Leadership: Charting the Future of US Higher Education," the report of the Secretary of Education's Commission on the Future of Higher Education, also known as the Spellings Commission. Blue ribbon panels rarely say much that is new or stimulate much sustained attention,…

A 30-meter spatial database for the nation's forests

Treesearch

Raymond L. Czaplewski

2002-01-01

The FIA vision for remote sensing originated in 1992 with the Blue Ribbon Panel on FIA, and it has since evolved into an ambitious performance target for 2003. FIA is joining a consortium of Federal agencies to map the Nation's land cover. FIA field data will help produce a seamless, standardized, national geospatial database for forests at the scale of 30-m...

Wyoming Community College Commission Agency 5 Year Strategic Plan, 2015-2019

ERIC Educational Resources Information Center

Wyoming Community College Commission, 2017

2017-01-01

In 2009, the Wyoming Community College Commission was tasked to create a blue-ribbon panel that would forge a Strategic Plan for the Community College System as a whole. This 5 year strategic plan will serve as a road map moving forward, barring any new legislative, commission or federal requirements that may require a change in the agency's…

Wyoming Community College Commission Agency 5 Year Strategic Plan, 2014-2018

ERIC Educational Resources Information Center

Wyoming Community College Commission, 2017

2017-01-01

In 2009, the Wyoming Community College Commission was tasked to create a blue-ribbon panel that would forge a Strategic Plan for the Community College System as a whole. This 5 year strategic plan will serve as a road map moving forward, barring any new legislative, commission or federal requirements that may require a change in the agency's…

Turnaround Schools: Practices Used by Nationally Recognized Principals to Improve Student Achievement in High Poverty Schools

ERIC Educational Resources Information Center

Brown, Angela Antuanette

2012-01-01

The specific purpose of this study was to identify the practices used by leaders of National Blue Ribbon Awarded Schools to successfully turnaround a school or to maintain proficient achievement scores within the school. The school principals answered a four part questionnaire for this study. Part 1 of the questionnaire asked about the extent to…

The Politics of Parochiaid: An Analysis of the 1993 Report on the Roman Catholic Schools in New York State.

ERIC Educational Resources Information Center

Bauer, Norman J.

This paper explores the question of the use of public state funds to support Catholic or any other denominational, nonpublic school. Thomas Sobol, Commissioner of Education, asked the Blue Ribbon Panel to examine the following significant matters: (1) the stress on tradition and work-related economic values derived by graduates of Catholic…

Nye County Nevada Perspectives on the State of the Yucca Mountain Project - 12388

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacy, Darrell; Voegele, Michael; Jaszczak, Casmier

2012-07-01

Responding to the Department of Energy decision to try to withdraw the Yucca Mountain license application and the Administration actions to close down the Yucca Mountain project, Nye County undertook a number of activities to articulate its support for continuing the Yucca Mountain project. The activities included responding to inquiries from federal agencies, including investigations undertaken by the Government Accountability Office addressing other potential uses for the Yucca Mountain site, responding to a Draft Environmental Impact Statement on the possible use of Yucca Mountain for disposal of Greater than Class C wastes, testifying in hearings, and interacting with the President'smore » Blue Ribbon Commission on America's Nuclear Future. The paper summarizes Nye County's position on the Yucca Mountain repository, Nye County's perspectives on the various activities that were developed and considered by the Government Accountability Office, Nye County's concerns with the use of the Nevada National Security Site for Disposal of Greater than Class C Low-Level Radioactive Wastes, testimony of Nye County officials expressing local community support for the Yucca Mountain project, and Nye County's perspectives on recommendations provided by the Blue Ribbon Commission to move the nation's high-level radioactive waste disposal programs forward without consideration of the role Yucca Mountain could have served in those recommendations. Nye County believes that every effort should be made to, at a minimum, fund the Nuclear Regulatory Commission to complete the license application review. Then, if Congress does decide to change the Nuclear Waste Policy Act, there will be valuable information available to support new policy development. This administration contends that Congressional language associated with the FY2010 and FY2011 appropriations and authorization process is sufficient evidence of its intent to terminate the Yucca Mountain repository program. The appropriation process needs to be explicit that, absent explicit language to the contrary, the Nuclear Waste Policy Act stands. It also should include language that requires the Department of Energy to preserve all necessary records until the Nuclear Waste Policy Act is amended or rescinded by specific Congressional action. (authors)« less

Student Evaluation of the Yellow Ribbon Suicide Prevention Program in Midwest Schools.

PubMed

Flynn, Alexandra; Zackula, Rosalee; Klaus, Nicole M; McGinness, Liz; Carr, Susan; Macaluso, Matthew

2016-01-01

Yellow Ribbon is a gatekeeper-type suicide prevention program that is widely used in public schools. However, data on its effectiveness are limited. The purpose of our study was to evaluate self-reported changes in knowledge and comfort level communicating about suicide following Yellow Ribbon training for a large, representative sample of students from a public school system in the midwestern United States. The program was administered to students within the same school district during 2006 through 2009. A pre-post survey using a 4-point Likert scale was administered to rate students' knowledge of risk factors and available resources, comfort level communicating about suicide, estimate of friends at risk for suicide, and behavioral intent toward help-seeking. Aggregate responses from 3,257 students, aged 11 to 18 years, were collected by the schools; 51% were female, 33% were Hispanic, and 30% were white. Suicide-related knowledge of risk factors, where to go for help, and resources, along with comfort level in asking for help, all significantly improved following program participation (Cramer's V = 0.243 to 0.376, P < .001). Responses were associated with age and gender, indicating that younger males may benefit more than older males. Implementation of the Yellow Ribbon school-based suicide prevention program appears to be beneficial for students in the midwestern United States. We observed significant improvement in knowledge, comfort level, and behavioral intent for help-seeking if suicidal thoughts occur. Findings also suggested that Yellow Ribbon training administered during middle school may be especially helpful for males.

Student Evaluation of the Yellow Ribbon Suicide Prevention Program in Midwest Schools

PubMed Central

Flynn, Alexandra; Zackula, Rosalee; Klaus, Nicole M.; McGinness, Liz; Carr, Susan; Macaluso, Matthew

2016-01-01

Objective Yellow Ribbon is a gatekeeper-type suicide prevention program that is widely used in public schools. However, data on its effectiveness are limited. The purpose of our study was to evaluate self-reported changes in knowledge and comfort level communicating about suicide following Yellow Ribbon training for a large, representative sample of students from a public school system in the midwestern United States. Methods The program was administered to students within the same school district during 2006 through 2009. A pre-post survey using a 4-point Likert scale was administered to rate students’ knowledge of risk factors and available resources, comfort level communicating about suicide, estimate of friends at risk for suicide, and behavioral intent toward help-seeking. Results Aggregate responses from 3,257 students, aged 11 to 18 years, were collected by the schools; 51% were female, 33% were Hispanic, and 30% were white. Suicide-related knowledge of risk factors, where to go for help, and resources, along with comfort level in asking for help, all significantly improved following program participation (Cramer’s V = 0.243 to 0.376, P < .001). Responses were associated with age and gender, indicating that younger males may benefit more than older males. Conclusions Implementation of the Yellow Ribbon school-based suicide prevention program appears to be beneficial for students in the midwestern United States. We observed significant improvement in knowledge, comfort level, and behavioral intent for help-seeking if suicidal thoughts occur. Findings also suggested that Yellow Ribbon training administered during middle school may be especially helpful for males. PMID:27733952

Ribbon cutting opens new ELV offices

NASA Technical Reports Server (NTRS)

2000-01-01

The audience applauds and enjoys the official opening of the E&O Building as the new site of the Expendable Launch Vehicle Program. Home for NASA's unmanned missions since 1964, the building has been renovated to house the ELV Program. Cutting the ribbon for the event were Deputy Manager of the ELV and Payload Carrier Programs, Steve Francois; Director of ELV Launch Services, Michael Benik; Center Director Roy Bridges; Manager of the ELV and Payload Carrier Programs, Bobby Bruckner; and Senior Manager of the Boeing ELV Program Support office, Jim Schofield.

The Changing Nature of the Role of the University Supervisor and Function of Preservice Teacher Supervision in an Era of Clinically-Rich Practice

ERIC Educational Resources Information Center

Burns, Rebecca West; Jacobs, Jennifer; Yendol-Hoppey, Diane

2016-01-01

Given the movement to enhanced clinical experiences and school-university collaboration emphasized in the NCATE Blue Ribbon Report, the field of teacher preparation would benefit from an understanding of the research related to preservice teacher (PST) supervision. This article uses qualitative meta-analysis to generate new knowledge about PST…

Southern Connections: Connecting with Each Other, Connecting with the Future. The Final Report of the 1998 Commission on the Future of the South.

ERIC Educational Resources Information Center

Morrison, Ed

Supported by the state governments of the South, the Southern Growth Policies Board creates strategies for regional economic development. Every 6 years, the Board's chairman (a state governor) appoints a blue-ribbon commission to analyze the condition of the South, develop regional objectives, and recommend approaches to regional problems. This…

Ribbon cutting opens new ELV offices

NASA Technical Reports Server (NTRS)

2000-01-01

Center Director Roy Bridges welcomes the audience to a ribbon- cutting ceremony at the E&O Building at KSC. Home for NASA's unmanned missions since 1964, the building has been renovated to house the Expendable Launch Vehicle Program.

An Assessment of Fiscal Year 2013 Beyond Yellow Ribbon Programs

DTIC Science & Technology

2015-01-01

2013 Beyond Yellow Ribbon Programs 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) RAND Corporation,National Defense Research Institute,1776 Main Street, P.O...Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSOR

Ribbon networks for modeling navigable paths of autonomous agents in virtual environments.

PubMed

Willemsen, Peter; Kearney, Joseph K; Wang, Hongling

2006-01-01

This paper presents the Environment Description Framework (EDF) for modeling complex networks of intersecting roads and pathways in virtual environments. EDF represents information about the layout of streets and sidewalks, the rules that govern behavior on roads and walkways, and the locations of agents with respect to navigable structures. The framework serves as the substrate on which behavior programs for autonomous vehicles and pedestrians are built. Pathways are modeled as ribbons in space. The ribbon structure provides a natural coordinate frame for defining the local geometry of navigable surfaces. EDF includes a powerful runtime interface supported by robust and efficient code for locating objects on the ribbon network, for mapping between Cartesian and ribbon coordinates, and for determining behavioral constraints imposed by the environment.

Caught in the act: visualization of an intermediate in the DNA base-flipping pathway induced by HhaI methyltransferase | Center for Cancer Research

Cancer.gov

HHAI methyltransferase (blue ribbon) bound to oligonucleotide (strands with bonds colored yellow and green) containing a pseudorotationally constrained sugar analogue at the target position (orange bonds with cyan atoms). The south-constrained pseudosugar is rotated about its flanking phosphodiester bonds, 90° from its initial position in B-form DNA, but short of a completely

Space Shuttle Projects

NASA Image and Video Library

1995-03-13

The STS-70 crew patch depicts the Space Shuttle Discovery orbiting Earth in the vast blackness of space. The primary mission of deploying a NASA Tracking and Data Relay Satellite (TDRS) is depicted by three gold stars. They represent the triad composed of spacecraft transmitting data to Earth through the TDRS system. The stylized red, white, and blue ribbon represents the American goal of linking space exploration to the advancement of all humankind.

Final Report of the Blue Ribbon Commission on Postsecondary Educational Attainment. State of Maine, 120th Legislature, First Regular Session.

ERIC Educational Resources Information Center

Elliott, David C.

In response to growing concern about the impact on economic prosperity resulting from the low level of higher educational attainment in Maine, two bills calling for study of that issue were introduced in the 120th Maine Legislature. A commission was created to develop a plan to improve the state's level of higher educational attainment. This…

Low Angle Silicon Sheet Growth. Large Area Silicon Sheet Task Low Cost Solar Array Project

NASA Technical Reports Server (NTRS)

1982-01-01

The results of a program to demonstrate the feasibility of a low angle silicon ribbon growth process are described. Twenty-six experimental runs were performed. Ribbons were grown at pull rates from 5 to 68 cm/min. Ribbon lengths up to 74 cm were grown while widths varied from 5 to 25 mm. Thicknesses varied from 0.6 to 2.5 mm, with typical values of about 1 mm.

Ultrastructural visualisation of proteoglycans in early unmineralised dentine of rat tooth germs stained with cuprolinic blue.

PubMed Central

Tenorio, D; Reid, A R; Katchburian, E

1990-01-01

The ultrastructural distribution and localisation of proteoglycans (PGs) of early developing rat dentine were examined using cuprolinic blue in a critical electrolyte concentration procedure. Results show that the cuprolinic blue method produces images of higher morphological quality than other cationic dyes. PGs appeared as ribbon-like electron-opaque precipitates of various sizes, ranging between 1.4 and 0.2 microns in length, distributed throughout the matrix and in close association with well preserved matrix vesicles and collagen fibrils. Matrix vesicles revealed tightly packed PG filaments which appeared to be attached to their membrane. It is possible that the close association of PG filaments with matrix vesicles and collagen indicates that PGs are related to the process of mineralisation of dentine. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:2384338

Pre-Cancer Atlas (PCA) and Other Human Tumor Atlas Network (HTAN) Funding Opportunity Announcements (FOAs) Released | Division of Cancer Prevention

Cancer.gov

There are 3 new funding opportunity announcements about the Pre-Cancer Atlas associated with the Beau Biden Cancer MoonshotSM Initiative that are intended to accelerate cancer research. The purpose of the FOAs is to promote research that results in a comprehensive view of the dynamic, multidimensional tumor ecosystem and is a direct response to the Moonshot Blue Ribbon Panel

The Ecology and Environmental Impact of Marshland and Estuaries

DTIC Science & Technology

1992-12-15

species of water snakes, blue runners , ribbon snakes, black snakes, and bull snakes, as well as water moccassins, rattlesnakes, copperheads, and coral...be encountered there that should receive special consideration is the swallow-tailed kite . Kites in general seem to be seriously declining in parts of...the southern U.S., and a couple have a tenuous hold on their environment or, in the case of the swallow-tailed kite , have an undetermined status

The World Nuclear University Alumni Assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

White-Horton, Jessica L; Lynch, Patrick D; Gilligan, Kimberly V

The World Nuclear University Summer Institute was established by the World Nuclear Association in 2005 as a program for future leaders in the nuclear field. Since the Summer Institute s inception in 2005, a total of some 800 fellows from more than 70 countries have participated in the program. In 2012, the World Nuclear University held its first ever alumni event at the IAEA in Vienna, Austria, and at that time, the precedent was set that the reunion would be held biennially. The 2014 alumni assembly was held at Oak Ridge National Laboratory from March 31 April 4, 2014. Themore » event offered three separate areas of opportunities for the participating alumni: professional development, leadership, and peer-to-peer engagement. The professional development consisted of training groups, while the leadership will involve discussions with invited leaders, including members of the Blue Ribbon Commission. The peer-to-peer engagement not only give past fellows a chance to reconnect with their own classmates, but it allowed for further international engagement, between the speakers and alumni, as well as between the classes themselves.« less

Large area silicon sheet by EFG

NASA Technical Reports Server (NTRS)

Kalejs, J. P.

1982-01-01

Work carried out on the JPL Flat Plate Solar Array Project, for the purpose of developing a method for silicon ribbon production by Edge-defined Film-fed Growth (EEG) for use as low-cost substrate material in terrestrial solar cell manufacture, is described. A multiple ribbon furnace unit that is designed to operate on a continuous basis for periods of at least one week, with melt replenishment and automatic ribbon width control, and to produce silicon sheet at a rate of one square meter per hour, was constructed. Program milestones set for single ribbon furnace operation to demonstrate basic EEG system capabilities with respect to growth speed, thickness and cell performance were achieved for 10 cm wide ribbon: steady-state growth at 4 cm/min and 200 micron thickness over periods of an hour and longer was made routine, and a small area cell efficiency of 13+% demonstrated. Large area cells of average efficiency of 10 to 11%, with peak values of 11 to 12% were also achieved. The integration of these individual performance levels into multiple ribbon furnace operation was not accomplished.

America Promises to Come Back: A New National Strategy

DTIC Science & Technology

1990-12-26

plants, and other government capa- bilities, should be studied by a Blue-Ribbon Panel assisted by 61 industria .. and proressional associations. This ertort...Conference of the International Institute for Strate- gic Studies (IISS) on September 6th, explained that the new strategic concepts would form the basis of...Reserve forces which could be returned within a reasonable period. This may not be the case , and America’s promise to return may indeed be within the

JPRS Report, East Europe

DTIC Science & Technology

1990-08-16

do you think elicited the Prime Minis- ter’s trust in you? [Kadar] I met Jozsef Antall for the first time when the Hid [ Bridge ] group was formed...general eco- nomic-policy concepts of the various parties, the Blue Ribbon Commission, and the Bridge group. Aside from a few trade union circles...their men’s weapons away from them." There is scarcely a Soviet military man who can imagine Soviet divisions staying on in a reunified Germany

Senior Enlisted Advisor to the CNGB - The National Guard

Science.gov Websites

, Army Good Conduct Medal, Army Service Ribbon, National Defense Service Ribbon, Armed Forces Reserve ARNG Command Sergeant Major of the ARNG State Mission Sustainability Training ARNG Distributed Learning Program Training & Technology Battle Lab (T3BL) Civil Support Simulation Exercises Regional Training

High-resolution laser-projection display system using a grating electromechanical system (GEMS)

NASA Astrophysics Data System (ADS)

Brazas, John C.; Kowarz, Marek W.

2004-01-01

Eastman Kodak Company has developed a diffractive-MEMS spatial-light modulator for use in printing and display applications, the grating electromechanical system (GEMS). This modulator contains a linear array of pixels capable of high-speed digital operation, high optical contrast, and good efficiency. The device operation is based on deflection of electromechanical ribbons suspended above a silicon substrate by a series of intermediate supports. When electrostatically actuated, the ribbons conform to the supporting substructure to produce a surface-relief phase grating over a wide active region. The device is designed to be binary, switching between a reflective mirror state having suspended ribbons and a diffractive grating state having ribbons in contact with substrate features. Switching times of less than 50 nanoseconds with sub-nanosecond jitter are made possible by reliable contact-mode operation. The GEMS device can be used as a high-speed digital-optical modulator for a laser-projection display system by collecting the diffracted orders and taking advantage of the low jitter. A color channel is created using a linear array of individually addressable GEMS pixels. A two-dimensional image is produced by sweeping the line image of the array, created by the projection optics, across the display screen. Gray levels in the image are formed using pulse-width modulation (PWM). A high-resolution projection display was developed using three 1080-pixel devices illuminated by red, green, and blue laser-color primaries. The result is an HDTV-format display capable of producing stunning still and motion images with very wide color gamut.

Ribbon-cutting officially opens Consolidated Support Operations Center at CCAS

NASA Technical Reports Server (NTRS)

1999-01-01

Cutting the ribbon at a ceremony for the opening of the Consolidated Support Operations Center at ROCC, Cape Canaveral Air Station, are (left to right) William P. Hickman, program manager, Space Gateway Support; Ed Gormel, executive director, JPMO; Barbara White, supervisor, Mission Support; KSC Center Director Roy Bridges, and Lt Col Steve Vuresky, USAF.

Cryogenic ribbon-cutting

NASA Image and Video Library

2011-03-30

NASA cut the ribbon on a new cryogenics control center at John C. Stennis Space Center on March 30. The new facility is part of a project to strengthen Stennis facilities to withstand the impacts of future storms like hurricane Katrina in 2005. Participants in the ribbon-cutting included (l to r): Jason Zuckerman, director of project management for The McDonnel Group; Keith Brock, director of the NASA Project Directorate at Stennis; Stennis Deputy Director Rick Gilbrech; Steve Jackson, outgoing program manager of the Jacobs Technology NASA Test Operations Group; and Troy Frisbie, Cryo Control Center Construction project manager for NASA Center Operations at Stennis.

The Civilian Airline Industry’s Role in Military Pilot Retention. Beggarman or Thief? Documented Briefing,

DTIC Science & Technology

1995-01-01

against civilian airline hiring, as reported by the Future Aviation Professionals of America ( FAPA ). The hiring data cited in the graph include...requirement for new pilot hires by major airlines. Data through 1992 are historical, from FAPA . Future data, from 1993 onward, are from the Blue Ribbon...historical data, we use actual data from FAPA . For future projections, we assume that (1) the airlines will continue to hire larger shares of military

National Cancer Moonshot Initiative platform | Office of Cancer Genomics

Cancer.gov

As part of the Vice President’s National Cancer Moonshot Initiative, the National Cancer Institute has launched an online engagement platform to enable the research community and the public to submit cancer research ideas to a Blue Ribbon Panel of scientific experts. Any member of the public is encouraged to submit his or her ideas for reducing the incidence of cancer and developing better ways to prevent, treat, and cure all types of cancer. Research ideas may be submitted in the following areas:

The Governance of the City University of New York A System at Odds with Itself

DTIC Science & Technology

2000-01-01

provided thoughtful and incisive commentary on drafts of this document. Early drafts also benefited from the reviews of task force staff mem - bers...requirements on the qualifications of mem - bers of the board. In particular, the law does not attempt to ensure that trustees have a measure of...establishing a blue-ribbon process for the appointment of the mem - bers of the Board of Trustees. Such a process would involve the cre- ation of

Development of variable-width ribbon heating elements for liquid-metal and gas-cooled fast breeder reactor fuel-pin simulators

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCulloch, R.W.; Post, D.W.; Lovell, R.T.

1981-04-01

Variable-width ribbon heating elements that provide a chopped-cosine variable heat flux profile have been fabricated for fuel pin simulators used in test loops by the Breeder Reactor Program Thermal-Hydraulic Out-of-Reactor Safety test facility and the Gas-Cooled Fast Breeder Reactor-Core Flow Test Loop. Thermal, mechanical, and electrical design considerations are used to derive an analytical expression that precisely describes ribbon contour in terms of the major fabrication parameters. These parameters are used to generate numerical control tapes that control ribbon cutting and winding machines. Infrared scanning techniques are developed to determine the optimum transient thermal profile of the coils and relatemore » this profile to that generated by the coils in completed fuel pin simulators.« less

Space Art "Among the Stars and Angels"

NASA Image and Video Library

2006-09-13

Artist Zigi Ben Haim cretaed this large triptych replete with many symbols that helps remember the lost STS-107. The aluminum panels were constructed to center around the ghostly outline of the Columbia space shuttle. References to the crew are evident including flowers representing Laurel Clarke whose nickname was Flora, the patch and a blurred diary of Ilan Roman, a sign on 74th Street in New York named after Kalpana Chawla. At the far right, 7 stars lie in an arc-like constellation. All of them are the same, except one, the Star of David representing Ramon, the first Israeli astronaut. In place of the astronauts’ faces, the artist employed color to capture the spirit of the person and their soul. Other symbols are evident including the NASA logo, a Texas license plate, an American flag, a blue ribbon representing excellence, Albert Einstein representing scientific knowledge and ants carrying heavy objects and propelling life forward. Triptych mixed media, 54x96. 2006. Copyrighted: For more information contact Curator, NASA Art Program.

US/German Collaboration in Salt Repository Research, Design and Operation - 13243

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steininger, Walter; Hansen, Frank; Biurrun, Enrique

2013-07-01

Recent developments in the US and Germany [1-3] have precipitated renewed efforts in salt repository investigations and related studies. Both the German rock salt repository activities and the US waste management programs currently face challenges that may adversely affect their respective current and future state-of-the-art core capabilities in rock salt repository science and technology. The research agenda being pursued by our respective countries leverages collective efforts for the benefit of both programs. The topics addressed by the US/German salt repository collaborations align well with the findings and recommendations summarized in the January 2012 US Blue Ribbon Commission on America's Nuclearmore » Future (BRC) report [4] and are consistent with the aspirations of the key topics of the Strategic Research Agenda of the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP) [5]. Against this background, a revival of joint efforts in salt repository investigations after some years of hibernation has been undertaken to leverage collective efforts in salt repository research, design, operations, and related issues for the benefit of respective programs and to form a basis for providing an attractive, cost-effective insurance against the premature loss of virtually irreplaceable scientific expertise and institutional memory. (authors)« less

Cancer Moonshot: What It Means for Patients.

PubMed

Mayer, Deborah K; Fuld Nasso, Shelley

2017-04-01

You may have heard of the National Cancer Moonshot Initiative led by former Vice President Joe Biden. It has brought together many people through a task force, blue ribbon panel, and many public forums to discuss how best "to dramatically accelerate efforts to prevent, diagnose, and treat cancer - to achieve a decade's worth of progress in 5 years." This initiative was launched after the 2016 State of the Union address, and the task force delivered recommendations to President Barack Obama on October 17, 2016, providing an opportunity to accelerate progress against cancer. 
.

Stress studies in EFG

NASA Technical Reports Server (NTRS)

1982-01-01

A program to study stress generation mechanisms in silicon sheet growth was started. The purpose of the research is to define post-growth temperature profiles for the sheet that can minimize its stress during growth at high speeds, e.g., greater than 3 cm/min. The initial tasks described concern work in progress toward the development of computing capabilities to (1) model stress-temperature relationships in steady-state ribbon growth, and (2) provide a means to calculate realistic temperature fields in ribbon, given growth system component temperatures as boundary conditions. If it is determined that low stress configurations can be achieved, the modeling is to be tested experimentally by constructing low-stress growth systems for EFG silicon ribbon.

A facile approach to fabricate porous nanocomposite gels based on partially hydrolyzed polyacrylamide and cellulose nanocrystals for adsorbing methylene blue at low concentrations.

PubMed

Zhou, Chengjun; Lee, Sunyoung; Dooley, Kerry; Wu, Qinglin

2013-12-15

Porous nanocomposite gels were fabricated by a facile method consisting of the electrospinning and subsequent heat treatment based on partially hydrolyzed polyacrylamide (HPAM) of ultra-high molecular weight, with cellulose nanocrystals (CNCs) as crosslinker. The effects of three electrospinning parameters (i.e., solution concentration, composition of solvent mixture, and CNC loading level) on morphology and diameter of electrospun fibers were systematically investigated. The swelling properties of porous gels and their application in the removal of methylene blue dye (as a compound representative of contaminants) were evaluated. Electrospun fiber morphologies without beads, branches, and ribbons were achieved by optimizing the electrospinning solutions. The thermal crosslinking between HPAM and CNCs was realized through esterification, rendering the product nanocomposite membranes insoluble in water. Electrospun fibers of approximately 220 nm in diameter comprised the 3D porous nanocomposite gels, with porosity greater than 50%. The porous nanocomposite gels displayed a rapid swelling rate and an efficient adsorption capacity in removing methylene blue at low concentrations from aqueous solutions. Copyright © 2013 Elsevier B.V. All rights reserved.

Subscale Test Program for the Orion Conical Ribbon Drogue Parachute

NASA Technical Reports Server (NTRS)

Sengupta, Anita; Stuart, Phil; Machin, Ricardo; Bourland, Gary; Schwing, Allen; Longmire, Ellen; Henning, Elsa; Sinclair, Rob

2011-01-01

A subscale wind tunnel test program for Orion's conical ribbon drogue parachute is under development. The desired goals of the program are to quantify aerodynamic performance of the parachute in the wake of the entry vehicle, including understanding of the coupling of the parachute and command module dynamics, and an improved understanding of the load distribution within the textile elements of the parachute. The test program is ten percent of full scale conducted in a 3x2.1 m (10x7 ft) closed loop subsonic wind tunnel. The subscale test program is uniquely suited to probing the aerodynamic and structural environment in both a quantitative and qualitative manner. Non-intrusive diagnostics, including Particle Image Velocimetry for wake velocity surveys, high speed pressure transducers for canopy pressure distribution, and a high speed photogrammetric reconstruction, will be used to quantify the parachute's performance.

Blue Ribbon Commission on America's Nuclear Future: Report to the Secretary of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2012-01-01

Preamble The Blue Ribbon Commission on America’s Nuclear Future (BRC) was formed by the Secretary of Energy at the request of the President to conduct a comprehensive review of policies for managing the back end of the nuclear fuel cycle and recommend a new strategy. It was co-chaired by Rep. Lee H. Hamilton and Gen. Brent Scowcroft. Other Commissioners are Mr. Mark H. Ayers, the Hon. Vicky A. Bailey, Dr. Albert Carnesale, Sen. Pete Domenici, Ms. Susan Eisenhower, Sen. Chuck Hagel, Mr. Jonathan Lash, Dr. Allison M. Macfarlane, Dr. Richard A. Meserve, Dr. Ernest J. Moniz, Dr. Per Peterson, Mr.more » John Rowe, and Rep. Phil Sharp. The Commission and its subcommittees met more than two dozen times between March 2010 and January 2012 to hear testimony from experts and stakeholders, to visit nuclear waste management facilities in the United States and abroad, and to discuss the issues identified in its Charter. Additionally, in September and October 2011, the Commission held five public meetings, in different regions of the country, to hear feedback on its draft report. A wide variety of organizations, interest groups, and individuals provided input to the Commission at these meetings and through the submission of written materials. Copies of all of these submissions, along with records and transcripts of past meetings, are available at the BRC website (www.brc.gov). This report highlights the Commission’s findings and conclusions and presents recommendations for consideration by the Administration and Congress, as well as interested state, tribal and local governments, other stakeholders, and the public.« less

Large Area Silicon Sheet by EFG

NASA Technical Reports Server (NTRS)

Wald, F. V.

1979-01-01

Displaced die concepts were explored along with some initial work on buckle characterization. Convective impurity redistribution was further studied. Growth from single cartridges was continued to create a quality baseline to allow comparison of the results with those in the upcoming multiple run and to choose the most appropriate die design. Fabrication and assembly work on the actual five ribbon furnace continued. Progress was made toward the development of the video optical system for edge position and meniscus height control. In preparation for a detailed program, designed to explore the buckling problem, ribbon guidance in the machine was improved. Buckle free, full width ribbon was grown under stable conditions without a cold shoe, an achievement essential to finally arrive at quantitative correlations between growth conditions and buckle formation.

Temperature dependent evolution of wrinkled single-crystal silicon ribbons on shape memory polymers.

PubMed

Wang, Yu; Yu, Kai; Qi, H Jerry; Xiao, Jianliang

2017-10-25

Shape memory polymers (SMPs) can remember two or more distinct shapes, and thus can have a lot of potential applications. This paper presents combined experimental and theoretical studies on the wrinkling of single-crystal Si ribbons on SMPs and the temperature dependent evolution. Using the shape memory effect of heat responsive SMPs, this study provides a method to build wavy forms of single-crystal silicon thin films on top of SMP substrates. Silicon ribbons obtained from a Si-on-insulator (SOI) wafer are released and transferred onto the surface of programmed SMPs. Then such bilayer systems are recovered at different temperatures, yielding well-defined, wavy profiles of Si ribbons. The wavy profiles are shown to evolve with time, and the evolution behavior strongly depends on the recovery temperature. At relatively low recovery temperatures, both wrinkle wavelength and amplitude increase with time as evolution progresses. Finite element analysis (FEA) accounting for the thermomechanical behavior of SMPs is conducted to study the wrinkling of Si ribbons on SMPs, which shows good agreement with experiment. Merging of wrinkles is observed in FEA, which could explain the increase of wrinkle wavelength observed in the experiment. This study can have important implications for smart stretchable electronics, wrinkling mechanics, stimuli-responsive surface engineering, and advanced manufacturing.

Large group intervention for military reintegration: peer support & Yellow Ribbon enhancements.

PubMed

Castellano, Cherie; Everly, George S

2010-01-01

University Behavioral HealthCare, University of Medicine and Dentistry of New Jersey in partnership with the New Jersey Department of Military & Veterans Affairs established a program entitled the "New Jersey Veterans Helpline," modeled after the "Cop 2 Cop Helpline," in 2005 to assist veterans and their families within the state. The events of September 11, 2001, demanded an unprecedented response to address the behavioral health care needs of first responders in New Jersey and highlighted the similarities amongst the military population in their response. Although the New Jersey Veterans Helpline program was initiated as a peer based helpline, the need for support in pre- and post-deployment quickly emerged. This paper describes the application of the Cop 2 Cop interventions with the Port Authority Police Department (PAPD) entitled "Acute Stress Management Reentry Program." This program was adapted and combined with Yellow Ribbon Guideline enhancements to create a "60 Day Resiliency & Reintegration Program" led by the New Jersey Veterans program to over 2,400 soldiers returning from war.

Development Of An 80'-Diameter Ribbon Drogue Parachute For The NASA X-38 Vehicle

NASA Technical Reports Server (NTRS)

Behr, Vance L.; Wolf, Dean F.; Rutledge, Bruce A.; Hillebrandt, F. David

2001-01-01

The NASA X-38 program required a larger, more robust drogue parachute. A multi-organizational team from NASA, Sandia National Laboratories, United Space Alliance, and Pioneer Aerospace Corporation has developed and tested a new 80-ft.-dia., quarter-spherical, ribbon drogue parachute. The design requirements, design specifics, margin analyses, and results of testing are all discussed herein. Some of the weight advantages of switching from Kevlar to Zylon for radial, line and riser materials are presented.

STS-29 Discovery, Orbiter Vehicle (OV) 103, crew insignia

NASA Image and Video Library

1988-11-23

S88-40316 (12 Dec. 1988) --- The STS-29 patch was designed to capture and represent the energy and dynamic nature of this nation's space program as America continues to look to the future. The folded ribbon border, the first of its kind in the shuttle patch series, gives a sense of three-dimensional depth to the emblem. The stylistic orbital maneuvering system (OMS) burn symbolizes the powerful forward momentum of the shuttle and a continuing determination to explore the frontiers of space. The colors of the U.S. flag are represented in the patch's basic red, white and blue background. In the border, the seven stars between the STS-29 crew names are a tribute to the crew of Challenger. The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the forms of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, the change will be publicly announced. Photo credit: NASA

Marine Biotoxins: Occurrence, Toxicity, and Detection Methods

NASA Astrophysics Data System (ADS)

Asakawa, M.

2017-04-01

This review summarizes the role of marine organisms as vectors of marine biotoxins, and discusses the need for surveillance to protect public health and ensure the quality of seafood. I Paralytic shellfish poison (PSP) and PSP-bearing organisms-PSP is produced by toxic dinoflagellates species belonging to the genera Alexandrium, Gymnodinium, and Pyrodinium. Traditionally, PSP monitoring programs have only considered filter-feeding molluscs that concentrate these toxic algae, however, increasing attention is now being paid to higher-order predators that carry PSP, such as carnivorous gastropods and crustaceans. II. Tetrodotoxin (TTX) and TTX-bearing organisms - TTX is the most common natural marine toxin that causes food poisonings in Japan, and poses a serious public health risk. TTX was long believed to be present only in pufferfish. However, TTX was detected in the eggs of California newt Taricha torosa in 1964, and since then it has been detected in a wide variety of species belonging to several different phyla. In this study, the main toxic components in the highly toxic ribbon worm Cephalothrix simula and the greater blue-ringed octopus Hapalochlaena lunulata from Japan were purified and analysed.

Societal-Equity-Enhancing Criteria and Facility-Host Incentives Supporting Five Key Elements in the January 2012 Blue Ribbon Commission Report - 13015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eriksson, Leif G.; Dials, George E.; George, Critz H.

2013-07-01

In February 2009, the Obama Administration announced it would abandon USA's only candidate SNF/HLW-disposal facility since 1987. In 2010, all related activities were stopped and the Blue Ribbon Commission on America's Nuclear Future was established 'to recommend a new strategy for managing the back end of the nuclear fuel cycle', which it did in January 2012, emphasizing eight key elements. However, Key Element 1, 'A new, consent-based approach to siting future nuclear facilities', is qualitative/indeterminate rather than quantitative/measurable. It is thus highly-susceptible to semantic permutations that could extend rather than, as intended, expedite the siting of future nuclear facilities unlessmore » it also defines: a) Whose consent is needed?; and b) What constitutes consent? The following 'generic', radiation-risk- and societal-equity-based criteria address these questions: 1. Identify areas affected by projected radiation and other health risks from: a. The proposed nuclear facility (facility stakeholders); and b. The related nuclear-materials-transportation routes (transportation stakeholders); then 2. Surround each stakeholder area with a buffer zone and use this enlarged foot print to identify: a. Stakeholder hosts; and b. Areas not hosting any stakeholder category (interested parties). 3. Define 'consent-based' as being at least 60 percent of the 'population' in the respective stakeholder category and apply this yardstick to both 'in favor' and 'against' votes. Although criteria 1 and 2 also need facility-based definitions to make Key Element 1 measurable, the described siting approach, augmented by related facility-host incentives, would expedite the schedule and reduce the cost for achieving Key Elements 4-6 and 8, politics permitting. (authors)« less

The Environmental Protection Agency's Safety Standards for Disposal of Spent Nuclear Fuel: Potential Path Forward in Response to the Report of the Blue Ribbon Commission on America's Nuclear Future - 13388

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forinash, Betsy; Schultheisz, Daniel; Peake, Tom

2013-07-01

Following the decision to withdraw the Yucca Mountain license application, the Department of Energy created a Blue Ribbon Commission (BRC) on America's Nuclear Future, tasked with recommending a national strategy to manage the back end of the nuclear fuel cycle. The BRC issued its final report in January 2012, with recommendations covering transportation, storage and disposal of spent nuclear fuel (SNF); potential reprocessing; and supporting institutional measures. The BRC recommendations on disposal of SNF and high-level waste (HLW) are relevant to the U.S. Environmental Protection Agency (EPA), which shares regulatory responsibility with the Nuclear Regulatory Commission (NRC): EPA issues 'generallymore » applicable' performance standards for disposal repositories, which are then implemented in licensing. For disposal, the BRC endorses developing one or more geological repositories, with siting based on an approach that is adaptive, staged and consent-based. The BRC recommends that EPA and NRC work cooperatively to issue generic disposal standards-applying equally to all sites-early in any siting process. EPA previously issued generic disposal standards that apply to all sites other than Yucca Mountain. However, the BRC concluded that the existing regulations should be revisited and revised. The BRC proposes a number of general principles to guide the development of future regulations. EPA continues to review the BRC report and to assess the implications for Agency action, including potential regulatory issues and considerations if EPA develops new or revised generic disposal standards. This review also involves preparatory activities to define potential process and public engagement approaches. (authors)« less

Advanced dendritic web growth development and development of single-crystal silicon dendritic ribbon and high-efficiency solar cell program

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Hopkins, R. H.

1986-01-01

Efforts to demonstrate that the dendritic web technology is ready for commercial use by the end of 1986 continues. A commercial readiness goal involves improvements to crystal growth furnace throughput to demonstrate an area growth rate of greater than 15 sq cm/min while simultaneously growing 10 meters or more of ribbon under conditions of continuous melt replenishment. Continuous means that the silicon melt is being replenished at the same rate that it is being consumed by ribbon growth so that the melt level remains constant. Efforts continue on computer thermal modeling required to define high speed, low stress, continuous growth configurations; the study of convective effects in the molten silicon and growth furnace cover gas; on furnace component modifications; on web quality assessments; and on experimental growth activities.

Electro-statically controllable graphene local heater

NASA Astrophysics Data System (ADS)

Wang, Hui-Shan; Deng, Lian-Wen; Li, Lei; Sun, Qiu-Juan; Xie, Hong; Wang, Hao-Min

2018-03-01

We report on current-induced thermal power investigation of graphene nanostructure for potential local-heating applications. It is found that the efficiency of heating can be greatly improved if graphene is patterned into structures with narrow width and long channel. In a narrow graphene-ribbon, the Joule heating power exhibits an obvious dependence on the back-gate voltage. By monitoring Raman spectra, the temperature of graphene-ribbon can be determined. The temperature of graphene-ribbon is modulated by the electric field effect when the sample is sourced with a relatively high current. Project supported by the National Key R&D Program of China (Grant No. 2017YFF0206106), the Chinese Academy of Sciences (Grant No. XDB04040300), the National Natural Science Foundation of China (Grant No. 51772317), and the Science and Technology Commission of Shanghai Municipality, China (Grant No. 16ZR1442700).

Monitoring environmental hazards and public health

NASA Astrophysics Data System (ADS)

Showstack, Randy

Saying that no national system exists to monitor public health problems linked to environmental hazards, former U.S. Senator Lowell Weicker, Jr., announced on May 11 the launch of a Pew Charitable Trusts blue ribbon panel to focus on this issue.The panel, which includes representatives from academia and health care organizations, will focus on how the United States tracks diseases and recommend ways to fill data gaps; review what tools are needed to improve disease tracking; and focus on children's health issues, such as asthma, childhood cancer, and birth defects that may be linked to the environment, according to Pew Environmental Health Commission Executive Director Shelley Hearne.

Progress Toward Cancer Data Ecosystems.

PubMed

Grossman, Robert L

One of the recommendations of the Cancer Moonshot Blue Ribbon Panel report from 2016 was the creation of a national cancer data ecosystem. We review some of the approaches for building cancer data ecosystems and some of the progress that has been made. A data commons is the colocation of data with cloud computing infrastructure and commonly used software services, tools, and applications for managing, integrating, analyzing, and sharing data to create an interoperable resource for the research community. We discuss data commons and their potential role in cancer data ecosystems and, in particular, how multiple data commons can interoperate to form part of the foundation for a cancer data ecosystem.

Characterization of Atrophic Changes in the Cerebral Cortex Using Fractal Dimensional Analysis

PubMed Central

George, Anuh T.; Jeon, Tina; Hynan, Linda S.; Youn, Teddy S.; Kennedy, David N.; Dickerson, Bradford

2010-01-01

The purpose of this project is to apply a modified fractal analysis technique to high-resolution T1 weighted magnetic resonance images in order to quantify the alterations in the shape of the cerebral cortex that occur in patients with Alzheimer’s disease. Images were selected from the Alzheimer’s Disease Neuroimaging Initiative database (Control N=15, Mild-Moderate AD N=15). The images were segmented using a semi-automated analysis program. Four coronal and three axial profiles of the cerebral cortical ribbon were created. The fractal dimensions (Df) of the cortical ribbons were then computed using a box-counting algorithm. The mean Df of the cortical ribbons from AD patients were lower than age-matched controls on six of seven profiles. The fractal measure has regional variability which reflects local differences in brain structure. Fractal dimension is complementary to volumetric measures and may assist in identifying disease state or disease progression. PMID:20740072

KENNEDY SPACE CENTER, FLA. - Daniel L. Tweed, with the Facilities Division, NASA Spaceport Services, addresses attendees at the ribbon cutting for the KSC Security gates. Tweed was project manager. The two new Security gates on Kennedy Parkway (Gate 2) and NASA Parkway (Gate 3) were activated Aug. 1, allowing the general public to have access to the new Space Commerce Way, which will provide access to the Research Park and KSC Visitor Complex, and providing an alternate route for the general public between Titusville and Merritt Island that is accessible 24 hours a day. The gates are staffed 24 hours daily. Others taking part in the ribbon cutting were Center Director Jim Kennedy; Chief, Protective & Safe Guards Office, Calvin L. Burch; SGS Deputy Program Manager William A. Sample; and Bobby Porter, with Oneida Construction.

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - Daniel L. Tweed, with the Facilities Division, NASA Spaceport Services, addresses attendees at the ribbon cutting for the KSC Security gates. Tweed was project manager. The two new Security gates on Kennedy Parkway (Gate 2) and NASA Parkway (Gate 3) were activated Aug. 1, allowing the general public to have access to the new Space Commerce Way, which will provide access to the Research Park and KSC Visitor Complex, and providing an alternate route for the general public between Titusville and Merritt Island that is accessible 24 hours a day. The gates are staffed 24 hours daily. Others taking part in the ribbon cutting were Center Director Jim Kennedy; Chief, Protective & Safe Guards Office, Calvin L. Burch; SGS Deputy Program Manager William A. Sample; and Bobby Porter, with Oneida Construction.

Baffles Promote Wider, Thinner Silicon Ribbons

NASA Technical Reports Server (NTRS)

Seidensticker, Raymond G.; Mchugh, James P.; Hundal, Rolv; Sprecace, Richard P.

1989-01-01

Set of baffles just below exit duct of silicon-ribbon-growing furnace reduces thermal stresses in ribbons so wider ribbons grown. Productivity of furnace increased. Diverts plume of hot gas from ribbon and allows cooler gas from top of furnace to flow around. Also shields ribbon from thermal radiation from hot growth assembly. Ribbon cooled to lower temperature before reaching cooler exit duct, avoiding abrupt drop in temperature as entering duct.

Silicon-sheet and thin-film cell and module technology potential: Issue study

NASA Technical Reports Server (NTRS)

Shimada, K.; Costogue, E. N.; Ferber, R. R.

1984-01-01

The development of high-efficiency low-cost crystalline silicon ribbon and thih-film solar cells for the energy national photovoltaics program was examined. The findings of an issue study conducted are presented. The collected data identified the status of the technology, future research needs, and problems experienced. The potentials of present research activities to meet the Federal/industry long-term technical goal of achieving 15 cents per kilowatt-hour levelized PV energy cost are assessed. Recommendations for future research needs related to crystalline silicon ribbon and thin-film technologies for flat-plate collectors are also included.

Yellow Ribbon Reintegration Program

Science.gov Websites

ABOUT US 10TH BIRTHDAY FIND AN EVENT FIND A RESOURCE EMPLOYMENT RESOURCES FINANCIAL PTSD and TBI they can access information on healthcare, education, employment, and financial and legal benefits

Flare Ribbons Approach Observed by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Ting; Zhang, Jun; Hou, Yijun, E-mail: liting@nao.cas.cn

We report flare ribbons approach (FRA) during a multiple-ribbon M-class flare on 2015 November 4 in NOAA AR 12443, obtained by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. The flare consisted of a pair of main ribbons and two pairs of secondary ribbons. The two pairs of secondary ribbons were formed later than the appearance of the main ribbons, with respective time delays of 15 and 19 minutes. The negative-polarity main ribbon spread outward faster than the first secondary ribbon with the same polarity in front of it, and thus the FRA was generated. Just before theirmore » encounter, the main ribbon was darkening drastically and its intensity decreased by about 70% in 2 minutes, implying the suppression of main-phase reconnection that produced two main ribbons. The FRA caused the deflection of the main ribbon to the direction of secondary ribbon with a deflection angle of about 60°. A post-approach arcade was formed about 2 minutes later and the downflows were detected along the new arcade with velocities of 35–40 km s{sup −1}, indicative of the magnetic restructuring during the process of FRA. We suggest that there are three topological domains with footpoints outlined by the three pairs of ribbons. Close proximity of these domains leads to deflection of the ribbons, which is in agreement with the magnetic field topology.« less

Edge Stabilized Ribbon (ESR); Stress, Dislocation Density and Electronic Performance

NASA Technical Reports Server (NTRS)

Sachs, E. M.

1984-01-01

The edge stabilized ribbon (ESR) silicon ribbon was grown in widths of 1, 2.2 and 4.0 inches at speeds ranging from .6 to 7 in/min, which result in ribbon thicknesses of 5 to 400 microns. One of the primary problems remaining in ESR growth is that of thermally induced mechanical stresses. This problem is manifested as ribbon with a high degree of residual stress or as ribbon with buckled ribbon. Thermal stresses result in a high dislocation density in the grown material, resulting in compromised electronic performance. Improvements in ribbon flatness were accomplished by modification of the ribbon cooling profile. Ribbon flatness and other experimental observations of ESR ribbon are discussed. Laser scanner measurements show a good correlation between diffusion length and dislocation density which indicates that the high dislocation densities are the primary cause of the poor current performance of ESR materials. Dislocation densities were reduced and improved electronic performance resulted. Laser scanner data on new and old material are presented.

Enlargement of Ribbons in Zebrafish Hair Cells Increases Calcium Currents But Disrupts Afferent Spontaneous Activity and Timing of Stimulus Onset

PubMed Central

Schreck, Mary; Petralia, Ronald S.; Wang, Ya-Xian; Zhang, Qiuxiang

2017-01-01

In sensory hair cells of auditory and vestibular organs, the ribbon synapse is required for the precise encoding of a wide range of complex stimuli. Hair cells have a unique presynaptic structure, the synaptic ribbon, which organizes both synaptic vesicles and calcium channels at the active zone. Previous work has shown that hair-cell ribbon size is correlated with differences in postsynaptic activity. However, additional variability in postsynapse size presents a challenge to determining the specific role of ribbon size in sensory encoding. To selectively assess the impact of ribbon size on synapse function, we examined hair cells in transgenic zebrafish that have enlarged ribbons, without postsynaptic alterations. Morphologically, we found that enlarged ribbons had more associated vesicles and reduced presynaptic calcium-channel clustering. Functionally, hair cells with enlarged ribbons had larger global and ribbon-localized calcium currents. Afferent neuron recordings revealed that hair cells with enlarged ribbons resulted in reduced spontaneous spike rates. Additionally, despite larger presynaptic calcium signals, we observed fewer evoked spikes with longer latencies from stimulus onset. Together, our work indicates that hair-cell ribbon size influences the spontaneous spiking and the precise encoding of stimulus onset in afferent neurons. SIGNIFICANCE STATEMENT Numerous studies support that hair-cell ribbon size corresponds with functional sensitivity differences in afferent neurons and, in the case of inner hair cells of the cochlea, vulnerability to damage from noise trauma. Yet it is unclear whether ribbon size directly influences sensory encoding. Our study reveals that ribbon enlargement results in increased ribbon-localized calcium signals, yet reduces afferent spontaneous activity and disrupts the timing of stimulus onset, a distinct aspect of auditory and vestibular encoding. These observations suggest that varying ribbon size alone can influence sensory encoding, and give further insight into how hair cells transduce signals that cover a wide dynamic range of stimuli. PMID:28546313

Can Shale Safely Host U.S. Nuclear Waste?

NASA Astrophysics Data System (ADS)

Neuzil, C. E.

2013-07-01

Even as cleanup efforts after Japan's Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America's Nuclear Future, 2012].

White House nominates nuclear commissioner

NASA Astrophysics Data System (ADS)

Showstack, Randy

2012-06-01

Just 3 days after U.S. Nuclear Regulatory Commission chairman Gregory Jaczko announced his intention to resign (Eos, 93(22), 211, doi:10.1029/2012EO220005, 2012), President Barack Obama nominated Allison Macfarlane to serve out the remainder of Jaczko's term, through June 2013. The White House announced that upon her appointment, Macfarlane would be designated as chair of the commission. Macfarlane is an associate professor of environmental science and policy at George Mason University. A member of the Blue Ribbon Commission on America's Nuclear Future from March 2010 to January 2012, she is also the author of the 2006 book Uncertainty Underground: Yucca Mountain and the Nation's High-Level Nuclear Waste and is an AGU member.

Ribbon Crystals

PubMed Central

Bohr, Jakob; Markvorsen, Steen

2013-01-01

A repetitive crystal-like pattern is spontaneously formed upon the twisting of straight ribbons. The pattern is akin to a tessellation with isosceles triangles, and it can easily be demonstrated with ribbons cut from an overhead transparency. We give a general description of developable ribbons using a ruled procedure where ribbons are uniquely described by two generating functions. This construction defines a differentiable frame, the ribbon frame, which does not have singular points, whereby we avoid the shortcomings of the Frenet–Serret frame. The observed spontaneous pattern is modeled using planar triangles and cylindrical arcs, and the ribbon structure is shown to arise from a maximization of the end-to-end length of the ribbon, i.e. from an optimal use of ribbon length. The phenomenon is discussed in the perspectives of incompatible intrinsic geometries and of the emergence of long-range order. PMID:24098360

Constellation Program: Lessons Learned. Volume 1; Executive Summary

NASA Technical Reports Server (NTRS)

Rhatigan, Jennifer L. (Editor)

2011-01-01

This document (Volume I) provides an executive summary of the lessons learned from the Constellation Program. A companion Volume II provides more detailed analyses for those seeking further insight and information. In this volume, Section 1.0 introduces the approach in preparing and organizing the content to enable rapid assimilation of the lessons. Section 2.0 describes the contextual framework in which the Constellation Program was formulated and functioned that is necessary to understand most of the lessons. Context of a former program may seem irrelevant in the heady days of new program formulation. However, readers should take some time to understand the context. Many of the lessons would be different in a different context, so the reader should reflect on the similarities and differences in his or her current circumstances. Section 3.0 summarizes key findings developed from the significant lessons learned at the program level that appear in Section 4.0. Readers can use the key findings in Section 3.0 to peruse for particular topics, and will find more supporting detail and analyses in Section 4.0 in a topical format. Appendix A contains a white paper describing the Constellation Program formulation that may be of use to readers wanting more context or background information. The reader will no doubt recognize some very similar themes from previous lessons learned, blue-ribbon committee reviews, National Academy reviews, and advisory panel reviews for this and other large-scale human spaceflight programs; including Apollo, Space Shuttle, Shuttle/Mir, and the ISS. This could represent an inability to learn lessons from previous generations; however, it is more likely that similar challenges persist in the Agency structure and approach to program formulation, budget advocacy, and management. Perhaps the greatest value of these Constellation lessons learned can be found in viewing them in context with these previous efforts to guide and advise the Agency and its stakeholders.

The SSMEPF opens with a ribbon-cutting ceremony

NASA Technical Reports Server (NTRS)

1998-01-01

KSC Center Director Roy D. Bridges Jr. and U.S. Congressman Dave Weldon (holding scissors) cut the ribbon at a ceremony on July 6 to open KSC's new 34,600-square-foot Space Shuttle Main Engine Processing Facility (SSMEPF). Joining in the ribbon cutting are (left) Ed Adamek, vice president and associate program manager for Ground Operations of United Space Alliance; Marvin L. Jones, director of Installation Operations; Donald R. McMonagle, manager of Launch Integration; (right) Wade Ivey of Ivey Construction, Inc.; Robert B. Sieck, director of Shuttle Processing; and John Plowden, vice president of Rocketdyne. A major addition to the existing Orbiter Processing Facility Bay 3, the SSMEPF replaces the Shuttle Main Engine Shop located in the Vehicle Assembly Building (VAB). The decision to move the shop out of the VAB was prompted by safety considerations and recent engine processing improvements. The first three main engines to be processed in the new facility will fly on Shuttle Endeavour's STS-88 mission in December 1998.

Ribbon curling

NASA Astrophysics Data System (ADS)

Juel, Anne; Prior, Chris; Moussou, Julien; Chakrabarti, Buddhapriya; Jensen, Oliver

The procedure of curling a ribbon by running it over a sharp blade is commonly used when wrapping presents. Despite its ubiquity, a quantitative explanation of this everyday phenomenon is still lacking. We address this using experiment and theory, examining the dependence of ribbon curvature on blade curvature, the longitudinal load imposed on the ribbon and the speed of pulling. Experiments in which a ribbon is drawn steadily over a blade under a fixed load show that the ribbon curvature is generated over a restricted range of loads, the curvature/load relationship can be non-monotonic, and faster pulling (under a constant imposed load) results in less tightly curled ribbons. We develop a theoretical model that captures these features, building on the concept that the ribbon under the imposed deformation undergoes differential plastic stretching across its thickness, resulting in a permanently curved shape. The model identifies factors that optimize curling and clarifies the physical mechanisms underlying the ribbon's nonlinear response to an apparently simple deformation.

Controlling the microstructure and associated magnetic properties of Ni 0.2Mn 3.2Ga 0.6 melt-spun ribbons by annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Mahmud; Alshammari, Ohud; Balasubramanian, Balamurugan

2017-03-01

Here we report on the structural and magnetic properties of Ni 0.2Mn 3.2Ga 0.6 melt-spun ribbons. The as-spun ribbons were found to exhibit mixed cubic phases that transform to non-cubic structure upon annealing. Additionally, an amorphous phase was found to co-exist in all ribbons. The SEM images show that minor grain formation occurs on the as-spun ribbons. However, the formation of extensive nano-grains was observed on the surfaces of the annealed ribbons. While the as-spun ribbons exhibit predominantly paramagnetic behavior, the ribbons annealed under various thermal conditions were found to be ferromagnetic with a Curie temperature of about 380 K.more » The ribbons annealed at 450 °C for 30 minutes exhibit a large coercive field of about 2500 Oe. The experimental results show that the microstructure and associated magnetic properties of the ribbons can be controlled by annealing techniques. The coercive fields and the shape of the magnetic hysteresis loops vary significantly with annealing conditions. As a result, exchange bias effects have also been observed in the annealed ribbons.« less

Generation Mechanisms of Quasi-parallel and Quasi-circular Flare Ribbons in a Confined Flare

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernandez-Perez, Aaron; Thalmann, Julia K.; Veronig, Astrid M.

We analyze a confined multiple-ribbon M2.1 flare (SOL2015-01-29T11:42) that originated from a fan-spine coronal magnetic field configuration, within active region NOAA 12268. The observed ribbons form in two steps. First, two primary ribbons form at the main flare site, followed by the formation of secondary ribbons at remote locations. We observe a number of plasma flows at extreme-ultraviolet temperatures during the early phase of the flare (as early as 15 minutes before the onset) propagating toward the formation site of the secondary ribbons. The secondary ribbon formation is co-temporal with the arrival of the pre-flare generated plasma flows. The primarymore » ribbons are co-spatial with Ramaty High Energy Spectroscopic Imager ( RHESSI ) hard X-ray sources, whereas no enhanced X-ray emission is detected at the secondary ribbon sites. The (E)UV emission, associated with the secondary ribbons, peaks ∼1 minute after the last RHESSI hard X-ray enhancement. A nonlinear force-free model of the coronal magnetic field reveals that the secondary flare ribbons are not directly connected to the primary ribbons, but to regions nearby. Detailed analysis suggests that the secondary brightenings are produced due to dissipation of kinetic energy of the plasma flows (heating due to compression), and not due to non-thermal particles accelerated by magnetic reconnection, as is the case for the primary ribbons.« less

Kinematics of ribbon-fin locomotion in the bowfin, Amia calva.

PubMed

Jagnandan, Kevin; Sanford, Christopher P

2013-12-01

An elongated dorsal and/or anal ribbon-fin to produce forward and backward propulsion has independently evolved in several groups of fishes. In these fishes, fin ray movements along the fin generate a series of waves that drive propulsion. There are no published data on the use of the dorsal ribbon-fin in the basal freshwater bowfin, Amia calva. In this study, frequency, amplitude, wavelength, and wave speed along the fin were measured in Amia swimming at different speeds (up to 1.0 body length/sec) to understand how the ribbon-fin generates propulsion. These wave properties were analyzed to (1) determine whether regional specialization occurs along the ribbon-fin, and (2) to reveal how the undulatory waves are used to control swimming speed. Wave properties were also compared between swimming with sole use of the ribbon-fin, and swimming with simultaneous use of the ribbon and pectoral fins. Statistical analysis of ribbon-fin kinematics revealed no differences in kinematic patterns along the ribbon-fin, and that forward propulsive speed in Amia is controlled by the frequency of the wave in the ribbon-fin, irrespective of the contribution of the pectoral fin. This study is the first kinematic analysis of the ribbon-fin in a basal fish and the model species for Amiiform locomotion, providing a basis for understanding ribbon-fin locomotion among a broad range of teleosts. © 2013 Wiley Periodicals, Inc.

Is Yucca Mountain a long-term solution for disposing of US spent nuclear fuel and high-level radioactive waste?

PubMed

Thorne, M C

2012-06-01

On 26 January 2012, the Blue Ribbon Commission on America's Nuclear Future released a report addressing, amongst other matters, options for the managing and disposal of high-level waste and spent fuel. The Blue Ribbon Commission was not chartered as a siting commission. Accordingly, it did not evaluate Yucca Mountain or any other location as a potential site for the storage or disposal of spent nuclear fuel and high-level waste. Nevertheless, if the Commission's recommendations are followed, it is clear that any future proposals to develop a repository at Yucca Mountain would require an extended period of consultation with local communities, tribes and the State of Nevada. Furthermore, there would be a need to develop generally applicable regulations for disposal of spent fuel and high-level radioactive waste, so that the Yucca Mountain site could be properly compared with alternative sites that would be expected to be identified in the initial phase of the site-selection process. Based on what is now known of the conditions existing at Yucca Mountain and the large number of safety, environmental and legal issues that have been raised in relation to the DOE Licence Application, it is suggested that it would be imprudent to include Yucca Mountain in a list of candidate sites for future evaluation in a consent-based process for site selection. Even if there were a desire at the local, tribal and state levels to act as hosts for such a repository, there would be enormous difficulties in attempting to develop an adequate post-closure safety case for such a facility, and in showing why this unsaturated environment should be preferred over other geological contexts that exist in the USA and that are more akin to those being studied and developed in other countries.

27 CFR 9.182 - Ribbon Ridge.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Ribbon Ridge. (a) Name. The name of the viticultural area described in this section is “Ribbon Ridge.” (b) Approved Maps. The appropriate maps used to determine the boundaries of the Ribbon Ridge viticultural area... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ribbon Ridge. 9.182...

27 CFR 9.182 - Ribbon Ridge.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Ribbon Ridge. (a) Name. The name of the viticultural area described in this section is “Ribbon Ridge.” (b) Approved Maps. The appropriate maps used to determine the boundaries of the Ribbon Ridge viticultural area... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ribbon Ridge. 9.182...

77 FR 9624 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Rescission, in Part, of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...) Multicolor Inc.; (7) Novelty Handicrafts Co., Ltd.; (8) Pacific Imports; (9) Papillon Ribbon & Bow (Canada... Lion Ribbon Company, Inc., for the following companies: (1) Apex Ribbon; (2) Apex Trimmings; (3) FinerRibbon.com ; (4) Hsien Chan Enterprise Co., Ltd.; (5) Hubschercorp; (6) Intercontinental Skyline; (7...

Patterned helical metallic ribbon for continuous edge winding applications

DOEpatents

Liebermann, Howard H.; Frischmann, Peter G.; Rosenberry, Jr., George M.

1983-04-19

Metallic ribbon having cutout patterns therein is provided in continuous helical form. The cutout patterns may be situated to intersect either or both of the ribbon edges or may be situated entirely within the ribbon. The helical ribbon with the cutout patterns may additionally have a nesting, or self-stacking, feature.

TWISTED RIBBON FUEL ELEMENT

DOEpatents

Breden, C.R.; Schultz, A.B.

1961-06-01

A reactor core formed of bundles of parallel fuel elements in the form of ribbons is patented. The fuel ribbons are twisted about their axes so as to have contact with one another at regions spaced lengthwise of the ribbons and to be out of contact with one another at locations between these spaced regions. The contact between the ribbons is sufficient to allow them to be held together in a stable bundle in a containing tube without intermediate support, while permitting enough space between the ribbon for coolant flowing.

When confrontational images may be counter productive: reinforcing the case for pre-testing communications in sensitive areas.

PubMed

Donovan, Robert J; Jalleh, Geoffrey; Fielder, Lynda; Ouschan, Robyn

2008-08-01

White Ribbon Day is an international campaign that encourages men to speak out about and demonstrate their opposition to violence against women by wearing a white ribbon on 25 November. This study assesses the effectiveness of a graphic confrontational image in the Australian 2006 campaign versus an alternative non-violent image to motivate men to wear a white ribbon on White Ribbon Day. An intercept survey was conducted with a sample of 45 males aged 30-49 years recruited in an inner city suburban shopping strip. Respondents were presented with two alternatives: a graphic 'amputated arm' image and a non-violent 'father-daughter' image. The primary dependent variable was the relative ability of the two alternatives in motivating respondents to wear a white ribbon on White Ribbon Day. The vast majority of respondents nominated the 'father-daughter' as image being more motivating than the 'amputated arm' image to wear a white ribbon on White Ribbon Day: 84% vs 9%. The bland 'father-daughter' image was far more motivating than the macabre/violent 'amputated arm' image in motivating men to wear a white ribbon on White Ribbon Day. This is contrary to the UNIFEM Australia and White Ribbon Day assertion that 'confrontational/provocative' images are necessary to achieve this behaviour.

Elasticity and Fluctuations of Incompatible Nanoribbons

NASA Astrophysics Data System (ADS)

Grossman, Doron; Sharon, Eran; Diamant, Haim

Geometrically incompatible ribbons are ubiquitous in nature, from the growing of biological tissues, to self assemblies of peptides and lipids. These exhibit unusual characteristics such shape bifurcations, and abnormal mechanical properties. When considering nano and micro ribbons, thermal fluctuations convert these properties into nontrivial statistics. We derive a reduced quasi-one-dimensional theory, which describes a wide range of incompatible elastic ribbons, and can be integrated into statistical mechanics formalism. Using it, we compute equilibrium configurations and statistical properties of two types of incompatible ribbons, with experimental significance: ribbons with positive spontaneous curvature, and ribbons with negative spontaneous curvature. The former, above a critical width, has a continuous family of degenerate configurations. In turn this causes the ribbons to behave as a random coils. The latter, however, exhibits a twisted-to-helical transition at a critical width, and behaves as an abnormal coil. It's persistence length is non-monotonic in the ribbon width and vanishes at a critical width, with principal modes of deformation different than compatible ribbons. Measurements of twisted ribbons made of chiral peptides, confirm some predictions of the model. European Research Council SoftGrowth project and The Harvey M. Kruger Family Center of Nanoscience and Nanotechnology.

Development of a process for producing ribbon shaped filaments. [production of silicon carbide filaments

NASA Technical Reports Server (NTRS)

Debolt, H. E.; Krukonis, V. J.

1973-01-01

Silicon carbide (SiC) ribbon filaments were produced on a carbon ribbon substrate, about 1500 microns (60 mils) wide and 100 microns (4 mils) thick in lengths up to 2 meters (6 ft), and with tensile strengths up to 142 KN/cm sq (206 Ksi). During the course of the study, ribbon filaments of boron were also produced on the carbon ribbon substrate; the boron ribbon produced was extremely fragile. The tensile strength of the SiC ribbon was limited by large growths or flaws caused by anomalies at the substrate surface; these anomalies were either foreign dirt or substrate imperfections or both. Related work carried out on round 100 micron (4 mils) diameter SiC filaments on a 33 micron (1.3 mil) diameter, very smooth carbon monofilament substrate has shown that tensile strengths as high as 551 KN/cm sq (800 Ksi) are obtainable with the SiC-carbon round substrate combination, and indicates that if the ribbon substrate surface and ribbon deposition process can be improved similar strengths can be realizable. Cost analysis shows that 100 micron x 5-10 micron SiC ribbon can be very low cost reinforcement material.

SEPARATION OF THE RIBBON FROM GLOBALLY DISTRIBUTED ENERGETIC NEUTRAL ATOM FLUX USING THE FIRST FIVE YEARS OF IBEX OBSERVATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwadron, N. A.; Moebius, E.; Kucharek, H.

2014-11-01

The Interstellar Boundary Explorer (IBEX) observes the IBEX ribbon, which stretches across much of the sky observed in energetic neutral atoms (ENAs). The ribbon covers a narrow (∼20°-50°) region that is believed to be roughly perpendicular to the interstellar magnetic field. Superimposed on the IBEX ribbon is the globally distributed flux that is controlled by the processes and properties of the heliosheath. This is a second study that utilizes a previously developed technique to separate ENA emissions in the ribbon from the globally distributed flux. A transparency mask is applied over the ribbon and regions of high emissions. We thenmore » solve for the globally distributed flux using an interpolation scheme. Previously, ribbon separation techniques were applied to the first year of IBEX-Hi data at and above 0.71 keV. Here we extend the separation analysis down to 0.2 keV and to five years of IBEX data enabling first maps of the ribbon and the globally distributed flux across the full sky of ENA emissions. Our analysis shows the broadening of the ribbon peak at energies below 0.71 keV and demonstrates the apparent deformation of the ribbon in the nose and heliotail. We show global asymmetries of the heliosheath, including both deflection of the heliotail and differing widths of the lobes, in context of the direction, draping, and compression of the heliospheric magnetic field. We discuss implications of the ribbon maps for the wide array of concepts that attempt to explain the ribbon's origin. Thus, we present the five-year separation of the IBEX ribbon from the globally distributed flux in preparation for a formal IBEX data release of ribbon and globally distributed flux maps to the heliophysics community.« less

Curling dynamics of naturally curved ribbons from high to low Reynolds numbers

NASA Astrophysics Data System (ADS)

Albarran Arriagada, Octavio; Massiera, Gladys; Abkarian, Manouk

2012-11-01

Curling deformation of thin elastic sheets appears in numerous structures in nature, such as membranes of red blood cells, epithelial tissues or green algae colonies to cite just a few examples. However, despite its ubiquity, the dynamics of curling propagation in a naturally curved material remains still poorly investigated. Here, we present a coupled experimental and theoretical study of the dynamical curling deformation of naturally curved ribbons. Using thermoplastic and metallic ribbons molded on cylinders of different radii, we tune separately the natural curvature and the geometry to study curling dynamics in air, water and in viscous oils, thus spanning a wide range of Reynolds numbers. Our theoretical and experimental approaches separate the role of elasticity, gravity and hydrodynamic dissipation from inertia and emphasize the fundamental differences between the curling of a naturally curved ribbon and a rod described by the classical Elastica. Our work shows evidence for the propagation of a single instability front, selected by a local buckling condition. We show that depending on gravity, and both the Reynolds and the Cauchy numbers, the curling speed and shape are modified by the large scale drag and the local lubrication forces. This work was supported by the French Ministry of Research, the CNRS Physics-Chemistry-Biology Interdisciplinary Pro- gram, the University Montpellier 2 Interdisciplinary Program and the Region Languedoc-Roussillon.

Deep Clouds

NASA Image and Video Library

2008-05-27

Bright puffs and ribbons of cloud drift lazily through Saturn's murky skies. In contrast to the bold red, orange and white clouds of Jupiter, Saturn's clouds are overlain by a thick layer of haze. The visible cloud tops on Saturn are deeper in its atmosphere due to the planet's cooler temperatures. This view looks toward the unilluminated side of the rings from about 18 degrees above the ringplane. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera on April 15, 2008 at a distance of approximately 1.5 million kilometers (906,000 miles) from Saturn. Image scale is 84 kilometers (52 miles) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA09910

Low cost silicon solar arrays

NASA Technical Reports Server (NTRS)

Ravi, K. V.; Serreze, H. B.; Bates, H. E.; Morrison, A. D.; Jewett, D. N.; Ho, J. C. T.; Schwuttke, G. H.; Ciszek, T. F.; Kran, A.

1975-01-01

Continuous growth methodology for silicon solar cell ribbons deals with capillary effects, die effects, thermal effects and crystal shape effects. Emphasis centers on the shape of the meniscus at the ribbon edge as a factor contributing to ribbon quality with respect to defect densities. Structural and electrical characteristics of edge defined, film-fed grown silicon ribbons are elaborated. Ribbon crystal solar cells produce AMO efficiencies of 6 to 10%.

Laser-zone growth in a Ribbon-To-Ribbon, RTR, process silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.

1977-01-01

A ribbon-to-ribbon process was used for routine growth of samples for analysis and fabrication into solar cells. One lot of solar cells was completely evaluated: ribbon solar cell efficiencies averaged 9.23% with a highest efficiency of 11.7%. Spherical reflectors have demonstrated significant improvements in laser silicon coupling efficiencies. Material analyses were performed including silicon photovoltage and open circuit photovoltage diffusion length measurements, crystal morphology studies, modulus of rupture measurements, and annealing/gettering studies. An initial economic analysis was performed indicating that ribbon-to-ribbon add-on costs of $.10/watt might be expected in the early 1980's.

Twisted, multifilament Nb3Sn superconductive ribbon

NASA Technical Reports Server (NTRS)

Coles, W. D.

1972-01-01

An experimental study of superconductor stabilization has resulted in the successful application of the concepts of filamentary structure and conductor twist to Nb3Sn ribbon. The Nb3Sn is formed in parallel, helical paths, which are continuous around the ribbon. Short lengths (12-18cm) of 1.27 cm wide superconductive ribbon were produced. The filamentary and twist characteristics are incorporated in the ribbon by means of an inert mask formed on the ribbon surface early in the fabrication process. Diffusion reaction of the niobium and tin is prevented at the filament boundaries. Described are the conductor methods of fabrication, and test results obtained. The technology required to adapt the processes for the production of long lengths of ribbon is available.

Silicon ribbon growth by a capillary action shaping technique

NASA Technical Reports Server (NTRS)

Schwuttke, G. H.; Schwuttke, G. H.; Ciszek, T. F.; Kran, A.

1977-01-01

Substantial improvements in ribbon surface quality are achieved with a higher melt meniscus than that attainable with the film-fed (EFG) growth technique. A capillary action shaping method is described in which meniscus shaping for the desired ribbon geometry occurs at the vertex of a wettable die. As ribbon growth depletes the melt meniscus, capillary action supplies replacement material. Topics discussed cover experimental apparatus and growth procedures; die materials investigations, fabrication and evaluation; process development for 25 mm, 38 mm, 50 mm and 100 mm silicon ribbons; and long grain direct solidification of silicon. Methods for the structural and electrical characterization of cast silicon ribbons are assessed as well as silicon ribbon technology for the 1978 to 1986 period.

Ca(2+) influx and neurotransmitter release at ribbon synapses.

PubMed

Cho, Soyoun; von Gersdorff, Henrique

2012-01-01

Ca(2+) influx through voltage-gated Ca(2+) channels triggers the release of neurotransmitters at presynaptic terminals. Some sensory receptor cells in the peripheral auditory and visual systems have specialized synapses that express an electron-dense organelle called a synaptic ribbon. Like conventional synapses, ribbon synapses exhibit SNARE-mediated exocytosis, clathrin-mediated endocytosis, and short-term plasticity. However, unlike non-ribbon synapses, voltage-gated L-type Ca(2+) channel opening at ribbon synapses triggers a form of multiquantal release that can be highly synchronous. Furthermore, ribbon synapses appear to be specialized for fast and high throughput exocytosis controlled by graded membrane potential changes. Here we will discuss some of the basic aspects of synaptic transmission at different types of ribbon synapses, and we will emphasize recent evidence that auditory and retinal ribbon synapses have marked differences. This will lead us to suggest that ribbon synapses are specialized for particular operating ranges and frequencies of stimulation. We propose that different types of ribbon synapses transfer diverse rates of sensory information by expressing a particular repertoire of critical components, and by placing them at precise and strategic locations, so that a continuous supply of primed vesicles and Ca(2+) influx leads to fast, accurate, and ongoing exocytosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of wheel speed and annealing temperature on microstructure and texture evolution of Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} ribbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Yan, E-mail: yanfeng@nwpu.edu.cn

Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} magnetic shape memory alloy was successfully produced as preferentially textured ribbon by melting spinning with different wheel speed. X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) were used to study structure and texture evolution of these melt-spun ribbons. The thickness of melt-spun ribbon is 42 μm, 65 μm and 30 μm depending on wheel speed of 1 0 m/s, 15 m/s and 20 m/s, respectively. Density of α fiber texture (〈100〉//ND) vary with wheel speed changes, and is most intensive in the ribbon with wheel speed of 15 m/s. Grains of the ribbons growmore » after being annealed at 873 K, 973 K, 1073 K and 1173 K, recrystallization was not observed in ribbons after being annealed at 873 K but occurred in ribbons after being annealed at higher temperatures. The α fiber texture becomes weaker to some extent after annealing at different temperatures, due to new recrystallization texture formed at the process of annealing. - Highlights: •Sectional part of shape memory ribbon is firstly investigated by EBSD method. •Thickness and texture of ribbons vary with wheel speed. •Annealing temperature affect texture and microstructure evolution greatly. •Recrystallization textures were observed in ribbons after being annealed.« less

Thick silicon growth techniques

NASA Technical Reports Server (NTRS)

Bates, H. E.; Mlavsky, A. I.; Jewett, D. N.

1973-01-01

Hall mobility measurements on a number of single crystal silicon ribbons grown from graphite dies have shown some ribbons to have mobilities consistent with their resistivities. The behavior of other ribbons appears to be explained by the introduction of impurities of the opposite sign. Growth of a small single crystal silicon ribbon has been achieved from a beryllia dia. Residual internal stresses of the order of 7 to 18,000 psi have been determined to exist in some silicon ribbon, particularly those grown at rates in excess of 1 in./min. Growth experiments have continued toward definition of a configuration and parameters to provide a reasonable yield of single crystal ribbons. High vacuum outgassing of graphite dies and evacuation and backfilling of growth chambers have provided significant improvements in surface quality of ribbons grown from graphite dies.

Are All Flare Ribbons Simply Connected to the Corona?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Judge, Philip G.; Paraschiv, Alin; Lacatus, Daniela

We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode , Solar Dynamics Observatory , and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, withmore » no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission.« less

Dry Ribbon for Heated Head Automated Fiber Placement

NASA Technical Reports Server (NTRS)

Hulcher, A. Bruce; Marchello, Joseph M.; Hinkley, Jeffrey A.; Johnston, Norman J.; Lamontia, Mark A.

2000-01-01

Ply-by-ply in situ processes involving automated heated head deposition are being developed for fabrication of high performance, high temperature composite structures from low volatile content polymer matrices. This technology requires (1) dry carbon fiber towpreg, (2) consolidation of towpreg to quality, placement-grade unidirectional ribbon or tape, and (3) rapid, in situ, accurate, ply-by-ply robotic placement and consolidation of this material to fabricate a composite structure. In this study, the physical properties of a candidate thermoplastic ribbon, PIXA/IM7, were evaluated and screened for suitability in robotic placement. Specifically, towpreg was prepared from PIXA powder. Various conditions (temperatures) were used to convert the powder-coated towpreg to ribbons with varying degrees of processability. Ribbon within preset specifications was fabricated at 3 temperatures: 390, 400 and 410 C. Ribbon was also produced out-of-spec by purposely overheating the material to a processing temperature of 450 C. Automated placement equipment at Cincinnati Milacron and NASA Langley was used to fabricate laminates from these experimental ribbons. Ribbons were placed at 405 and 450 C by both sets of equipment. Double cantilever beam and wedge peel tests were used to determine the quality of the laminates and, especially, the interlaminar bond formed during the placement process. Ribbon made under conditions expected to be non-optimal (overheated) resulted in poor placeability and composites with weak interlaminar bond strengths, regardless of placement conditions. Ribbon made under conditions expected to be ideal showed good processability and produced well-consolidated laminates. Results were consistent from machine to machine and demonstrated the importance of ribbon quality in heated-head placement of dry material forms. Preliminary screening criteria for the development and evaluation of ribbon from new matrix materials were validated.

Process for fabricating continuous lengths of superconductor

DOEpatents

Kroeger, Donald M.; List, III, Frederick A.

1998-01-01

A process for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor precursor between said first substrate ribbon and said second substrates ribbon. The layered superconductor precursor is then heat treated to form a super conductor layer.

Acute destruction of the synaptic ribbon reveals a role for the ribbon in vesicle priming.

PubMed

Snellman, Josefin; Mehta, Bhupesh; Babai, Norbert; Bartoletti, Theodore M; Akmentin, Wendy; Francis, Adam; Matthews, Gary; Thoreson, Wallace; Zenisek, David

2011-07-24

In vision, balance and hearing, sensory receptor cells translate sensory stimuli into electrical signals whose amplitude is graded with stimulus intensity. The output synapses of these sensory neurons must provide fast signaling to follow rapidly changing stimuli while also transmitting graded information covering a wide range of stimulus intensity and must be able to sustain this signaling for long time periods. To meet these demands, specialized machinery for transmitter release, the synaptic ribbon, has evolved at the synaptic outputs of these neurons. We found that acute disruption of synaptic ribbons by photodamage to the ribbon markedly reduced both sustained and transient components of neurotransmitter release in mouse bipolar cells and salamander cones without affecting the ultrastructure of the ribbon or its ability to localize synaptic vesicles to the active zone. Our results indicate that ribbons mediate both slow and fast signaling at sensory synapses and support an additional role for the synaptic ribbon in priming vesicles for exocytosis at active zones.

Ribbon curling via stress relaxation in thin polymer films

PubMed Central

Prior, Chris; Moussou, Julien; Chakrabarti, Buddhapriya

2016-01-01

The procedure of curling a ribbon by running it over a sharp blade is commonly used when wrapping presents. Despite its ubiquity, a quantitative explanation of this everyday phenomenon is still lacking. We address this using experiment and theory, examining the dependence of ribbon curvature on blade curvature, the longitudinal load imposed on the ribbon, and the speed of pulling. Experiments in which a ribbon is drawn steadily over a blade under a fixed load show that the ribbon curvature is generated over a restricted range of loads, the curvature/load relationship can be nonmonotonic, and faster pulling (under a constant imposed load) results in less tightly curled ribbons. We develop a theoretical model that captures these features, building on the concept that the ribbon under the imposed deformation undergoes differential plastic stretching across its thickness, resulting in a permanently curved shape. The model identifies factors that optimize curling and clarifies the physical mechanisms underlying the ribbon’s nonlinear response to an apparently simple deformation. PMID:26831118

Innervation regulates synaptic ribbons in lateral line mechanosensory hair cells

PubMed Central

Pujol, Remy; Cunningham, Dale E.; Hailey, Dale W.; Prendergast, Andrew; Rubel, Edwin W.; Raible, David W.

2016-01-01

ABSTRACT Failure to form proper synapses in mechanosensory hair cells, the sensory cells responsible for hearing and balance, leads to deafness and balance disorders. Ribbons are electron-dense structures that tether synaptic vesicles to the presynaptic zone of mechanosensory hair cells where they are juxtaposed with the post-synaptic endings of afferent fibers. They are initially formed throughout the cytoplasm, and, as cells mature, ribbons translocate to the basolateral membrane of hair cells to form functional synapses. We have examined the effect of post-synaptic elements on ribbon formation and maintenance in the zebrafish lateral line system by observing mutants that lack hair cell innervation, wild-type larvae whose nerves have been transected and ribbons in regenerating hair cells. Our results demonstrate that innervation is not required for initial ribbon formation but suggest that it is crucial for regulating the number, size and localization of ribbons in maturing hair cells, and for ribbon maintenance at the mature synapse. PMID:27103160

Innervation regulates synaptic ribbons in lateral line mechanosensory hair cells.

PubMed

Suli, Arminda; Pujol, Remy; Cunningham, Dale E; Hailey, Dale W; Prendergast, Andrew; Rubel, Edwin W; Raible, David W

2016-06-01

Failure to form proper synapses in mechanosensory hair cells, the sensory cells responsible for hearing and balance, leads to deafness and balance disorders. Ribbons are electron-dense structures that tether synaptic vesicles to the presynaptic zone of mechanosensory hair cells where they are juxtaposed with the post-synaptic endings of afferent fibers. They are initially formed throughout the cytoplasm, and, as cells mature, ribbons translocate to the basolateral membrane of hair cells to form functional synapses. We have examined the effect of post-synaptic elements on ribbon formation and maintenance in the zebrafish lateral line system by observing mutants that lack hair cell innervation, wild-type larvae whose nerves have been transected and ribbons in regenerating hair cells. Our results demonstrate that innervation is not required for initial ribbon formation but suggest that it is crucial for regulating the number, size and localization of ribbons in maturing hair cells, and for ribbon maintenance at the mature synapse. © 2016. Published by The Company of Biologists Ltd.

Texture inheritance from austenite to 7 M martensite in Ni-Mn-Ga melt-spun ribbons

NASA Astrophysics Data System (ADS)

Li, Zongbin; Jiang, Yiwen; Li, Zhenzhuang; Yang, Yiqiao; Yang, Bo; Zhang, Yudong; Esling, Claude; Zhao, Xiang; Zuo, Liang

In this work, Ni53Mn22Ga25 and Ni51Mn27Ga22 ribbons with austenite and 7 M martensite at room temperature respectively, were prepared by melt-spinning. Through the detailed crystallographic analyses, the preferred orientation in ribbons was confirmed. It is shown that the austenite in Ni53Mn22Ga25 ribbons forms a preferred orientation with {4 0 0}A in parallel to ribbon plane, whereas the 7 M martensite in Ni51Mn27Ga22 ribbons develops the preferred orientation with {2 0 -20}7M, {2 0 20}7M, and {0 4 0}7M crystallographic planes parallel to the ribbon plane. Since {2 0 -20}7M, {2 0 20}7M, and {0 4 0}7M are originated from {4 0 0}A, the preferred orientation in ribbons thus can be inherited after the martensitic transformation. Such texture inheritance is attributed to the intrinsic orientation relationship between austenite and 7 M martensite.

The status of silicon ribbon growth technology for high-efficiency silicon solar cells

NASA Technical Reports Server (NTRS)

Ciszek, T. F.

1985-01-01

More than a dozen methods have been applied to the growth of silicon ribbons, beginning as early as 1963. The ribbon geometry has been particularly intriguing for photovoltaic applications, because it might provide large area, damage free, nearly continuous substrates without the material loss or cost of ingot wafering. In general, the efficiency of silicon ribbon solar cells has been lower than that of ingot cells. The status of some ribbon growth techniques that have achieved laboratory efficiencies greater than 13.5% are reviewed, i.e., edge-defined, film-fed growth (EFG), edge-supported pulling (ESP), ribbon against a drop (RAD), and dendritic web growth (web).

OBSERVATIONS OF AN X-SHAPED RIBBON FLARE IN THE SUN AND ITS THREE-DIMENSIONAL MAGNETIC RECONNECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Y.; Ding, M. D.; Yang, K.

2016-05-20

We report evolution of an atypical X-shaped flare ribbon that provides novel observational evidence of three-dimensional (3D) magnetic reconnection at a separator. The flare occurred on 2014 November 9. High-resolution slit-jaw 1330 Å images from the Interface Region Imaging Spectrograph reveal four chromospheric flare ribbons that converge and form an X-shape. Flare brightening in the upper chromosphere spreads along the ribbons toward the center of the “X” (the X-point), and then spreads outward in a direction more perpendicular to the ribbons. These four ribbons are located in a quadrupolar magnetic field. Reconstruction of magnetic topology in the active region suggestsmore » the presence of a separator connecting to the X-point outlined by the ribbons. The inward motion of flare ribbons in the early stage therefore indicates 3D magnetic reconnection between two sets of non-coplanar loops that approach laterally, and reconnection proceeds downward along a section of vertical current sheet. Coronal loops are also observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory confirming the reconnection morphology illustrated by ribbon evolution.« less

CIRCULARITY OF THE INTERSTELLAR BOUNDARY EXPLORER RIBBON OF ENHANCED ENERGETIC NEUTRAL ATOM (ENA) FLUX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Funsten, H. O.; Higdon, D. M.; Larsen, B. A.

2013-10-10

As a sharp feature in the sky, the ribbon of enhanced energetic neutral atom (ENA) flux observed by the Interstellar Boundary Explorer (IBEX) mission is a key signature for understanding the interaction of the heliosphere and the interstellar medium through which we are moving. Over five nominal IBEX energy passbands (0.7, 1.1, 1.7, 2.7, and 4.3 keV), the ribbon is extraordinarily circular, with a peak location centered at ecliptic (λ{sub RC}, β{sub RC}) = (219.°2 ± 1.°3, 39.°9 ± 2.°3) and a half cone angle of φ{sub C} = 74.°5 ± 2.°0. A slight elongation of the ribbon, generally perpendicularmore » to the ribbon center-heliospheric nose vector and with eccentricity ∼0.3, is observed over all energies. At 4.3 keV, the ribbon is slightly larger and displaced relative to lower energies. For all ENA energies, a slice of the ribbon flux peak perpendicular to the circular arc is asymmetric and systematically skewed toward the ribbon center. We derive a spatial coherence parameter δ{sub C} ≤ 0.014 that characterizes the spatial uniformity of the ribbon over its extent in the sky and is a key constraint for understanding the underlying processes and structure governing the ribbon ENA emission.« less

Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares

NASA Astrophysics Data System (ADS)

Hinterreiter, J.; Veronig, A. M.; Thalmann, J. K.; Tschernitz, J.; Pötzi, W.

2018-03-01

A statistical study of the chromospheric ribbon evolution in Hα two-ribbon flares was performed. The data set consists of 50 confined (62%) and eruptive (38%) flares that occurred from June 2000 to June 2015. The flares were selected homogeneously over the Hα and Geostationary Operational Environmental Satellite (GOES) classes, with an emphasis on including powerful confined flares and weak eruptive flares. Hα filtergrams from the Kanzelhöhe Observatory in combination with Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) magnetograms were used to derive the ribbon separation, the ribbon-separation velocity, the magnetic-field strength, and the reconnection electric field. We find that eruptive flares reveal statistically larger ribbon separation and higher ribbon-separation velocities than confined flares. In addition, the ribbon separation of eruptive flares correlates with the GOES SXR flux, whereas no clear dependence was found for confined flares. The maximum ribbon-separation velocity is not correlated with the GOES flux, but eruptive flares reveal on average a higher ribbon-separation velocity (by ≈ 10 km s-1). The local reconnection electric field of confined (cc=0.50 ±0.02) and eruptive (cc=0.77 ±0.03) flares correlates with the GOES flux, indicating that more powerful flares involve stronger reconnection electric fields. In addition, eruptive flares with higher electric-field strengths tend to be accompanied by faster coronal mass ejections.

Centrifugally decoupling touchdown bearings

DOEpatents

Post, Richard F

2014-06-24

Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

Are All Flare Ribbons Simply Connected to the Corona?

NASA Astrophysics Data System (ADS)

Judge, Philip G.; Paraschiv, Alin; Lacatus, Daniela; Donea, Alina; Lindsey, Charlie

2017-04-01

We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode, Solar Dynamics Observatory, and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, with no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission. The National Center for Atmospheric Research is sponsored by the National Science Foundation.

Holographic hierarchy in the Gaussian matrix model via the fuzzy sphere

NASA Astrophysics Data System (ADS)

Garner, David; Ramgoolam, Sanjaye

2013-10-01

The Gaussian Hermitian matrix model was recently proposed to have a dual string description with worldsheets mapping to a sphere target space. The correlators were written as sums over holomorphic (Belyi) maps from worldsheets to the two-dimensional sphere, branched over three points. We express the matrix model correlators by using the fuzzy sphere construction of matrix algebras, which can be interpreted as a string field theory description of the Belyi strings. This gives the correlators in terms of trivalent ribbon graphs that represent the couplings of irreducible representations of su(2), which can be evaluated in terms of 3j and 6j symbols. The Gaussian model perturbed by a cubic potential is then recognised as a generating function for Ponzano-Regge partition functions for 3-manifolds having the worldsheet as boundary, and equipped with boundary data determined by the ribbon graphs. This can be viewed as a holographic extension of the Belyi string worldsheets to membrane worldvolumes, forming part of a holographic hierarchy linking, via the large N expansion, the zero-dimensional QFT of the Matrix model to 2D strings and 3D membranes. Note that if, after removing the white vertices, the graph contains a blue edge connecting to the same black vertex at both ends, then the triangulation generated from the black edges will contain faces that resemble cut discs. These faces are triangles with two of the edges identified.

78 FR 14963 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Rescission, in Part, of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... companies: (1) Apex Ribbon; (2) Apex Trimmings Inc. (d.b.a. Papillon Ribbon & Bow (Canada)) (Apex Trimmings... an administrative review for the following companies: (1) Apex Ribbon; (2) Apex Trimmings; (3...; (2) Apex Trimmings; (3) Hubschercorp; (4) [[Page 14964

Silicon ribbon growth by a capillary action shaping technique

NASA Technical Reports Server (NTRS)

Schwuttke, G. H.; Ciszek, T. F.; Kran, A.; Yang, K.

1977-01-01

The crystal-growth method under investigation is a capillary action shaping technique. Meniscus shaping for the desired ribbon geometry occurs at the vertex of a wettable dye. As ribbon growth depletes the melt meniscus, capillary action supplies replacement material. The configuration of the technique used in our initial studies is shown. The crystal-growth method has been applied to silicon ribbons it was found that substantial improvements in ribbon surface quality could be achieved with a higher melt meniscus than that attainable with the EFG technique.

Statistical mechanics of ribbons under bending and twisting torques.

PubMed

Sinha, Supurna; Samuel, Joseph

2013-11-20

We present an analytical study of ribbons subjected to an external torque. We first describe the elastic response of a ribbon within a purely mechanical framework. We then study the role of thermal fluctuations in modifying its elastic response. We predict the moment-angle relation of bent and twisted ribbons. Such a study is expected to shed light on the role of twist in DNA looping and on bending elasticity of twisted graphene ribbons. Our quantitative predictions can be tested against future single molecule experiments.

Apparatus for fabricating continuous lengths of superconductor

DOEpatents

Kroeger, Donald M.; List, III, Frederick A.

2002-01-01

A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

Apparatus for fabricating continuous lengths of superconductor

DOEpatents

Kroeger, Donald M.; List, III, Frederick A.

2001-01-01

A process and apparatus for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.

Continuous lengths of oxide superconductors

DOEpatents

Kroeger, Donald M.; List, III, Frederick A.

2000-01-01

A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.

Guidance system for low angle silicon ribbon growth

DOEpatents

Jewett, David N.; Bates, Herbert E.; Milstein, Joseph B.

1986-07-08

In a low angle silicon sheet growth process, a puller mechanism advances a seed crystal and solidified ribbon from a cooled growth zone in a melt at a low angle with respect to the horizontal. The ribbon is supported on a ramp adjacent the puller mechanism. Variations in the vertical position of the ribbon with respect to the ramp are isolated from the growth end of the ribbon by (1) growing the ribbon so that it is extremely thin, preferably less than 0.7 mm, (2) maintaining a large growth zone, preferably one whose length is at least 5.0 cm, and (3) spacing the ramp from the growth zone by at least 15 cm.

KSC-00pp1668

NASA Image and Video Library

2000-11-08

The audience applauds and enjoys the official opening of the E&O Building as the new site of the Expendable Launch Vehicle Program. Home for NASA’s unmanned missions since 1964, the building has been renovated to house the ELV Program.; Cutting the ribbon for the event were Deputy Manager of the ELV and Payload Carrier Programs, Steve Francois; Director of ELV Launch Services, Michael Benik; Center Director Roy Bridges; Manager of the ELV and Payload Carrier Programs, Bobby Bruckner; and Senior Manager of the Boeing ELV Program Support office, Jim Schofield

Chirality effect in disordered graphene ribbon junctions

NASA Astrophysics Data System (ADS)

Long, Wen

2012-05-01

We investigate the influence of edge chirality on the electronic transport in clean or disordered graphene ribbon junctions. By using the tight-binding model and the Landauer-Büttiker formalism, the junction conductance is obtained. In the clean sample, the zero-magnetic-field junction conductance is strongly chirality-dependent in both unipolar and bipolar ribbons, whereas the high-magnetic-field conductance is either chirality-independent in the unipolar or chirality-dependent in the bipolar ribbon. Furthermore, we study the disordered sample in the presence of magnetic field and find that the junction conductance is always chirality-insensitive for both unipolar and bipolar ribbons with adequate disorders. In addition, the disorder-induced conductance plateaus can exist in all chiral bipolar ribbons provided the disorder strength is moderate. These results suggest that we can neglect the effect of edge chirality in fabricating electronic devices based on the magnetotransport in a disordered graphene ribbon.

Sm5(Fe,Ti)17 melt-spun ribbons with high coercivity

NASA Astrophysics Data System (ADS)

Saito, Tetsuji; Horita, Toru

2018-05-01

It has previously been reported that annealing of amorphous Sm5Fe17 melt-spun ribbon resulted in the formation of the Sm5Fe17 phase and the resultant Sm5Fe17 melt-spun ribbon exhibited a high coercivity. However, the annealing condition of the amorphous Sm5Fe17 melt-spun ribbon was somewhat critical and it was not easy to obtain Sm5Fe17 grains with high coercivity. In the present study, it was found that the small substitution of Ti for Fe in the Sm5Fe17 melt-spun ribbon stabilized the Sm5Fe17 phase. Annealed Sm5Fe16.7Ti0.3 melt-spun ribbon consisted of small and homogeneous Sm5(Fe,Ti)17 grains and exhibited a higher coercivity than the annealed Sm5Fe17 melt-spun ribbon.

Asymmetric Die Grows Purer Silicon Ribbon

NASA Technical Reports Server (NTRS)

Kalejs, J. P.; Chalmers, B.; Surek, T.

1983-01-01

Concentration of carbide impurities in silicon ribbon is reduced by growing crystalline ribbon with die one wall higher than other. Height difference controls shape of meniscus at liquid/crystal interface and concentrates silicon carbide impurity near one of broad faces. Opposite face is left with above-average purity. Significantly improves efficiency of solar cells made from ribbon.

Investigation of ablation of thin foil aluminum ribbon array at 1.5 MA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Fan, E-mail: yefan1931@126.com; Li, Zhenghong; Chen, Faxin

We present experimental studies of initiation and ablation of a thin foil aluminum ribbon array at the 1.5 MA current level. In contrast to the previous work, we employ ribbon arrays with different ribbon gap parameters to investigate how this affects plasma initiation and foil ablation. Gated narrowband ultraviolet imaging indicated that the current was disorderly distributed at early period of discharge. But later on, it became axially stable and azimuthally symmetrical even for load with a gap as small as 0.1 mm. Using magnetic field probes installed inside and outside the array, we also observed that precursor current at positionsmore » with a distance of less than 2.7 mm to the central axis for 4-mm-radius arrays decreased when ribbon gap became small. Results of 0.2 mm gap ribbon array showed an evidence that ribbons can be merged. These observations imply that thin foil ribbon arrays may have potential applications in z-pinch experiments on large scale pulsed power facilities.« less

Large area silicon sheet by EFG

NASA Technical Reports Server (NTRS)

1981-01-01

Progress was made in improving ribbon flatness and reducing stress, and in raising cell performance for 10 cm wide ribbon grown in single cartridge EFG furnaces. Optimization of growth conditions resulted in improved ribbon thickness uniformity at a thickness of 200 micron, grown at 4 cm/minute, and growth at this target speed is routinely achieved over periods of the order of one hour or more. With the improved ribbon flatness, fabrication of large area (50 cm2) cells is now possible, and 10 to 11% efficiencies were demonstrated on ribbon grown at 3.5 to 4 cm/minute. Factors limiting performance of the existing multiple ribbon furnace were identified, and growth system improvements implemented to help raise throughput rates and the time percentage of simultaneous three-ribbon growth. However, it is evident that major redesign of this furnace would be needed to overcome shortfalls in its ability to achieve the Technical Features Demonstration goals of 1980. It was decided to start construction of a new multiple ribbon furnace and to incorporate the desired improvements into its design. The construction of this furnace is completed.

KENNEDY SPACE CENTER, FLA. - Hundreds of guests attend a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

NASA Image and Video Library

2003-06-20

KENNEDY SPACE CENTER, FLA. - Hundreds of guests attend a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

Roller compaction: Effect of morphology and amorphous content of lactose powder on product quality.

PubMed

Omar, Chalak S; Dhenge, Ranjit M; Osborne, James D; Althaus, Tim O; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

2015-12-30

The effect of morphology and amorphous content, of three types of lactose, on the properties of ribbon produced using roller compaction was investigated. The three types of lactose powders were; anhydrous SuperTab21AN, α-lactose monohydrate 200 M, and spray dried lactose SuperTab11SD. The morphology of the primary particles was identified using scanning electron microscopy (SEM) and the powder amorphous content was quantified using NIR technique. SEM images showed that 21AN and SD are agglomerated type of lactose whereas the 200 M is a non-agglomerated type. During ribbon production, an online thermal imaging technique was used to monitor the surface temperature of the ribbon. It was found that the morphology and the amorphous content of lactose powders have significant effects on the roller compaction behaviour and on ribbon properties. The agglomerated types of lactose produced ribbon with higher surface temperature and tensile strength, larger fragment size, lower porosity and lesser fines percentages than the non-agglomerated type of lactose. The lactose powder with the highest amorphous content showed to result in a better binding ability between the primary particles. This type of lactose produced ribbons with the highest temperature and tensile strength, and the lowest porosity and amount of fines in the product. It also produced ribbon with more smooth surfaces in comparison to the other two types of lactose. It was noticed that there is a relationship between the surface temperature of the ribbon during production and the tensile strength of the ribbon; the higher the temperature of the ribbon during production the higher the tensile strength of the ribbon. Copyright © 2015 Elsevier B.V. All rights reserved.

Synaptic Ribbon Active Zones in Cone Photoreceptors Operate Independently from One Another

PubMed Central

Grassmeyer, Justin J.; Thoreson, Wallace B.

2017-01-01

Cone photoreceptors depolarize in darkness to release glutamate-laden synaptic vesicles. Essential to release is the synaptic ribbon, a structure that helps organize active zones by clustering vesicles near proteins that mediate exocytosis, including voltage-gated Ca2+ channels. Cone terminals have many ribbon-style active zones at which second-order neurons receive input. We asked whether there are functionally significant differences in local Ca2+ influx among ribbons in individual cones. We combined confocal Ca2+ imaging to measure Ca2+ influx at individual ribbons and patch clamp recordings to record whole-cell ICa in salamander cones. We found that the voltage for half-maximal activation (V50) of whole cell ICa in cones averaged −38.1 mV ± 3.05 mV (standard deviation [SD]), close to the cone membrane potential in darkness of ca. −40 mV. Ca2+ signals at individual ribbons varied in amplitude from one another and showed greater variability in V50 values than whole-cell ICa, suggesting that Ca2+ signals can differ significantly among ribbons within cones. After accounting for potential sources of technical variability in measurements of Ca2+ signals and for contributions from cone-to-cone differences in ICa, we found that the variability in V50 values for ribbon Ca2+ signals within individual cones showed a SD of 2.5 mV. Simulating local differences in Ca2+ channel activity at two ribbons by shifting the V50 value of ICa by ±2.5 mV (1 SD) about the mean suggests that when the membrane depolarizes to −40 mV, two ribbons could experience differences in Ca2+ influx of >45%. Further evidence that local Ca2+ changes at ribbons can be regulated independently was obtained in experiments showing that activation of inhibitory feedback from horizontal cells (HCs) to cones in paired recordings changed both amplitude and V50 of Ca2+ signals at individual ribbons. By varying the strength of synaptic output, differences in voltage dependence and amplitude of Ca2+ signals at individual ribbons shape the information transmitted from cones to downstream neurons in vision. PMID:28744203

Variation of Hardness and Modulus across thickness of Zr-Cu-Al Metallic Glass Ribbons

Treesearch

Z. Humberto Melgarejo; J.E. Jakes; J. Hwang; Y.E. Kalay; M.J. Kramer; P.M. Voyles; D.S. Stone

2012-01-01

We investigate through-thickness hardness and modulus of Zr50Cu45Al5 metallic glass melt-spun ribbon. Because of their thinness, the ribbons are challenging to measure, so we employ a novel nanoindentation based-method to remove artifacts caused by ribbon flexing and edge effects. Hardness and modulus...

ARC-2008-ACD08-0065-051

NASA Image and Video Library

2008-04-11

Lunar Science Institute (LSI) Grand Opening. Ribbon Cutting, L-R: James Green, Director, Planetary Programs, NASA Headquarters, Mike Honda, U.S. Congressman,15th District, Apollo Astronaut Buzz Aldrin, S. Pete Worden, Director, NASA Ames Research Center, David Morrison, Interiu Director, NASA Lunar Science Institute. David Morse at podium.

Tree Wave Migration Across an Elevation Gradient in the Altai Mountains, Siberia

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Dvinskaya, Maria L.; Ranson, Kenneth J.; Petrov, Il'ya

2017-01-01

The phenomenon of tree waves (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberian pine (Pinus sibirica) forms hedges on windward slopes and ribbons on the leeward ones. Hedges were formed by prevailing winds and oriented along winds direction. Ribbons were formed by snow blowing and accumulating on the leeward slope and perpendicular to the prevailing winds, as well as to the elevation gradient. Hedges were always linked with microtopography features, whereas ribbons were not. Trees are migrating upward by waves and new ribbons and hedges are forming at or near tree line, whereas at lower elevations ribbons and hedges are being transformed into closed forests. 19 Time series of high-resolution satellite scenes (from 1968 to 2010) indicated an upslope shift in the position ribbons averaged 15526 m (or 3.7 m yr -1) and crown closure increased (about 3590). The hedges advance was limited by poor regeneration establishment and was negligible. Regeneration within the ribbon zone was approximately 2.5 times (5060 vs 2120 ha -1) higher then within the hedges zone. During the last four decades, Siberian pine in both hedges and ribbons strongly increased its growth increment and recent tree growth rate for 50 year old trees was about twice higher than recorded for similarly aged trees at the beginning of the 20th century. Hedges and ribbons are phenomena that are widespread within the southern and northern Siberian Mountains

Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare

NASA Astrophysics Data System (ADS)

Li, Ting; Yang, Shuhong; Zhang, Qingmin; Hou, Yijun; Zhang, Jun

2018-06-01

We analyze a unique event with an M1.8 confined circular-ribbon flare on 2016 February 13, with successive formations of two circular ribbons at the same location. The flare had two distinct phases of UV and extreme ultraviolet emissions with an interval of about 270 s, of which the second peak was energetically more important. The first episode was accompanied by the eruption of a mini-filament and the fast elongation motion of a thin circular ribbon (CR1) along the counterclockwise direction at a speed of about 220 km s‑1. Two elongated spine-related ribbons were also observed, with the inner ribbon co-temporal with CR1 and the remote brightenings forming ∼20 s later. In the second episode, another mini-filament erupted and formed a blowout jet. The second circular ribbon and two spine-related ribbons showed similar elongation motions with that during the first episode. The extrapolated three-dimensional coronal magnetic fields reveal the existence of a fan-spine topology, together with a quasi-separatrix layer (QSL) halo surrounding the fan plane and another QSL structure outlining the inner spine. We suggest that continuous null-point reconnection between the filament and ambient open field occurs in each episode, leading to the sequential opening of the filament and significant shifts of the fan plane footprint. For the first time, we propose a compound eruption model of circular-ribbon flares consisting of two sets of successively formed ribbons and eruptions of multiple filaments in a fan-spine-type magnetic configuration.

Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares.

PubMed

Hinterreiter, J; Veronig, A M; Thalmann, J K; Tschernitz, J; Pötzi, W

2018-01-01

A statistical study of the chromospheric ribbon evolution in H[Formula: see text] two-ribbon flares was performed. The data set consists of 50 confined (62%) and eruptive (38%) flares that occurred from June 2000 to June 2015. The flares were selected homogeneously over the H[Formula: see text] and Geostationary Operational Environmental Satellite (GOES) classes, with an emphasis on including powerful confined flares and weak eruptive flares. H[Formula: see text] filtergrams from the Kanzelhöhe Observatory in combination with Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) magnetograms were used to derive the ribbon separation, the ribbon-separation velocity, the magnetic-field strength, and the reconnection electric field. We find that eruptive flares reveal statistically larger ribbon separation and higher ribbon-separation velocities than confined flares. In addition, the ribbon separation of eruptive flares correlates with the GOES SXR flux, whereas no clear dependence was found for confined flares. The maximum ribbon-separation velocity is not correlated with the GOES flux, but eruptive flares reveal on average a higher ribbon-separation velocity (by ≈ 10 km s -1 ). The local reconnection electric field of confined ([Formula: see text]) and eruptive ([Formula: see text]) flares correlates with the GOES flux, indicating that more powerful flares involve stronger reconnection electric fields. In addition, eruptive flares with higher electric-field strengths tend to be accompanied by faster coronal mass ejections. The online version of this article (10.1007/s11207-018-1253-1) contains supplementary material, which is available to authorized users.

Passive diffusion as a mechanism underlying ribbon synapse vesicle release and resupply.

PubMed

Graydon, Cole W; Zhang, Jun; Oesch, Nicholas W; Sousa, Alioscka A; Leapman, Richard D; Diamond, Jeffrey S

2014-07-02

Synaptic ribbons are presynaptic protein structures found at many synapses that convey graded, "analog" sensory signals in the visual, auditory, and vestibular pathways. Ribbons, typically anchored to the presynaptic membrane and surrounded by tethered synaptic vesicles, are thought to regulate or facilitate vesicle delivery to the presynaptic membrane. No direct evidence exists, however, to indicate how vesicles interact with the ribbon or, once attached, move along the ribbon's surface to reach the presynaptic release sites at its base. To address these questions, we have created, validated, and tested a passive vesicle diffusion model of retinal rod bipolar cell ribbon synapses. We used axial (bright-field) electron tomography in the scanning transmission electron microscopy to obtain 3D structures of rat rod bipolar cell terminals in 1-μm-thick sections of retinal tissue at an isotropic spatial resolution of ∼3 nm. The resulting structures were then incorporated with previously published estimates of vesicle diffusion dynamics into numerical simulations that accurately reproduced electrophysiologically measured vesicle release/replenishment rates and vesicle pool sizes. The simulations suggest that, under physiologically realistic conditions, diffusion of vesicles crowded on the ribbon surface gives rise to a flow field that enhances delivery of vesicles to the presynaptic membrane without requiring an active transport mechanism. Numerical simulations of ribbon-vesicle interactions predict that transient binding and unbinding of multiple tethers to each synaptic vesicle may achieve sufficiently tight association of vesicles to the ribbon while permitting the fast diffusion along the ribbon that is required to sustain high release rates. Copyright © 2014 the authors 0270-6474/14/348948-15$15.00/0.

Fluid-Structure Interaction Study on a Pre-Buckled Deformable Flat Ribbon

NASA Astrophysics Data System (ADS)

Fovargue, Lauren; Shams, Ehsan; Watterson, Amy; Corson, Dave; Filardo, Benjamin; Zimmerman, Daniel; Shan, Bob; Oberai, Assad

2015-11-01

A Fluid-Structure Interaction study is conducted for the flow over a deformable flat ribbon. This mechanism, which is called ribbon frond, maybe used as a device for pumping water and/or harvesting energy in rivers. We use a lower dimensional mathematical model, which represents the ribbon as a pre-buckled structure. The surface forces from the fluid flow, dictate the deformation of the ribbon, and the ribbon in turn imposes boundary conditions for the incompressible Navier-Stokes equations. The mesh motion is handled using an Arbitrary Lagrangian-Eulerian (ALE) scheme and the fluid-structure coupling is handled by iterating over the staggered governing equations for the structure, the fluid and the mesh. Simulations are conducted at three different free stream velocities. The results, including the frequency of oscillations, show agreement with experimental data. The vortical structures near the surface of the ribbon and its deformation are highly correlated. It is observed that the ribbon motion exhibits deviation from a harmonic motion, especially at lower free stream velocities. The behavior of the ribbon is compared to swimming animals, such as eels, in order to better understand its performance. The authors acknowledge support from ONR SBIR Phase II, contract No. N0001412C0604 and USDA, NIFA SBIR Phase I, contract No. 2013-33610-20836 and NYSERDA PON 2569, contract No. 30364.

Melt dumping in string stabilized ribbon growth

DOEpatents

Sachs, Emanuel M.

1986-12-09

A method and apparatus for stabilizing the edge positions of a ribbon drawn from a melt includes the use of wettable strings drawn in parallel up through the melt surface, the ribbon being grown between the strings. A furnace and various features of the crucible used therein permit continuous automatic growth of flat ribbons without close temperature control or the need for visual inspection.

Self-assembly of a nanotube from a black phosphorus nanoribbon on a string of fullerenes at low temperature.

PubMed

Cai, Kun; Shi, Jiao; Liu, Ling-Nan; Qin, Qing-Hua

2017-09-13

A string of fullerenes is used for generating a nanotube by self-assembly of a black phosphorus (BP) nanoribbon at a temperature of 8 K. Among the fullerenes in the string, there are at least two fixed fullerenes placed along the edge of the BP ribbon for keeping its configuration stability during winding. By way of molecular dynamics simulations, it is found that successful generation of a BP nanotube depends on the bending stiffness of the ribbon and the attraction between the fullerenes and the ribbon. When the attraction is strong enough, the two edges (along the zigzag direction) of the BP ribbon will be able to bond covalently to form a nanotube. By the molecular dynamics approach, the maximum width of the BP ribbon capable of forming a nanotube with a perfect length is investigated in three typical models. The maximum width of the BP ribbon becomes larger with the string containing more fullerenes. This finding reveals a way to control the width of the BP ribbon which forms a nanotube. It provides guidance for fabricating a BP nanotube with a specified length, the same as to the width of the ribbon.

Scandal and Tragedy Or Acquisition Lessons Relearned by the F-35 Program

DTIC Science & Technology

2017-01-01

Ribbon Commission on Defense Management , referred to as the Packard Commission Report, determined that MDAPs take too long to develop, cost too much...understanding program management discipline. Yin (1994) and Patton (2002) believed a deep-rooted and multilevel case study analysis could help formulate... management ), good recommendations come from open questions, often applying the researcher’s and SME’s own expe- riences, instead of from scientific

Wearable energy-smart ribbons for synchronous energy harvest and storage

PubMed Central

Li, Chao; Islam, Md. Monirul; Moore, Julian; Sleppy, Joseph; Morrison, Caleb; Konstantinov, Konstantin; Dou, Shi Xue; Renduchintala, Chait; Thomas, Jayan

2016-01-01

A promising energy source for many current and future applications is a ribbon-like device that could simultaneously harvest and store energy. Due to the high flexibility and weavable property, a fabric/matrix made using these ribbons could be highly beneficial for powering wearable electronics. Unlike the approach of using two separate devices, here we report a ribbon that integrates a solar cell and a supercapacitor. The electrons generated by the solar cell are directly transferred and stored on the reverse side of its electrode which in turn also functions as an electrode for the supercapacitor. When the flexible solar ribbon is illuminated with simulated solar light, the supercapacitor holds an energy density of 1.15 mWh cm−3 and a power density of 243 mW cm−3. Moreover, these ribbons are successfully woven into a fabric form. Our all-solid-state ribbon unveils a highly flexible and portable self-sufficient energy system with potential applications in wearables, drones and electric vehicles. PMID:27834367

Laser-zone growth in a Ribbon-To-Ribbon (RTR) process silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.; Wise, J.; Ellis, R. J.

1977-01-01

The Ribbon-to-Ribbon (RTR) approach to silicon ribbon growth was investigated. An existing RTR apparatus, RTR#1, was upgraded to allow for 5 cm wide ribbon growth with a finite stroke length of at least 15 cm. A second RTR apparatus, RTR#2, was designed, built, and operated which utilizes continuous feed mechanisms and allows continuous growth of 7.5 cm wide ribbons. RTR#2 includes development and utilization of advanced beam scanning (or shaping), high power lasers, and thermal profile modification elements to attain maximum growth velocities (with a design goal of 18 cm/min). Materials studies, process development, and thermal analyses are also described. Residual stresses and dislocation densities were minimized through theoretical and experimental efforts towards optimization of thermal profiles. Growth runs were performed on RTR#2 and solar cells were fabricated which demonstrated efficiencies greater than 10%.

Wearable energy-smart ribbons for synchronous energy harvest and storage

NASA Astrophysics Data System (ADS)

Li, Chao; Islam, Md. Monirul; Moore, Julian; Sleppy, Joseph; Morrison, Caleb; Konstantinov, Konstantin; Dou, Shi Xue; Renduchintala, Chait; Thomas, Jayan

2016-11-01

A promising energy source for many current and future applications is a ribbon-like device that could simultaneously harvest and store energy. Due to the high flexibility and weavable property, a fabric/matrix made using these ribbons could be highly beneficial for powering wearable electronics. Unlike the approach of using two separate devices, here we report a ribbon that integrates a solar cell and a supercapacitor. The electrons generated by the solar cell are directly transferred and stored on the reverse side of its electrode which in turn also functions as an electrode for the supercapacitor. When the flexible solar ribbon is illuminated with simulated solar light, the supercapacitor holds an energy density of 1.15 mWh cm-3 and a power density of 243 mW cm-3. Moreover, these ribbons are successfully woven into a fabric form. Our all-solid-state ribbon unveils a highly flexible and portable self-sufficient energy system with potential applications in wearables, drones and electric vehicles.

Wearable energy-smart ribbons for synchronous energy harvest and storage.

PubMed

Li, Chao; Islam, Md Monirul; Moore, Julian; Sleppy, Joseph; Morrison, Caleb; Konstantinov, Konstantin; Dou, Shi Xue; Renduchintala, Chait; Thomas, Jayan

2016-11-11

A promising energy source for many current and future applications is a ribbon-like device that could simultaneously harvest and store energy. Due to the high flexibility and weavable property, a fabric/matrix made using these ribbons could be highly beneficial for powering wearable electronics. Unlike the approach of using two separate devices, here we report a ribbon that integrates a solar cell and a supercapacitor. The electrons generated by the solar cell are directly transferred and stored on the reverse side of its electrode which in turn also functions as an electrode for the supercapacitor. When the flexible solar ribbon is illuminated with simulated solar light, the supercapacitor holds an energy density of 1.15 mWh cm -3 and a power density of 243 mW cm -3 . Moreover, these ribbons are successfully woven into a fabric form. Our all-solid-state ribbon unveils a highly flexible and portable self-sufficient energy system with potential applications in wearables, drones and electric vehicles.

The Role of Ribbons at Sensory Synapses

PubMed Central

LoGiudice, Lisamarie; Matthews, Gary

2009-01-01

Synaptic ribbons are organelles that tether vesicles at the presynaptic active zones of sensory neurons in the visual, auditory and vestibular systems. These neurons generate sustained, graded electrical signals in response to sensory stimuli, and fidelity of transmission therefore requires their synapses to release neurotransmitter continuously at high rates. It has long been thought that the ribbons at the active zones of sensory synapses accomplish this task by enhancing the size and accessibility of the readily releasable pool of synaptic vesicles, which may represent the vesicles attached to the ribbon. Recent evidence suggests that synaptic ribbons immobilize vesicles in the resting cell and coordinate the transient, synchronous release of vesicles in response to stimulation, but it is not yet clear how the ribbon can efficiently mobilize and coordinate multiple vesicles for release. However, detailed anatomical, electrophysiological and optical studies have begun to reveal the mechanics of release at ribbon synapses, and this multidisciplinary approach promises to reconcile structure, function, and mechanism at these important sensory synapses. PMID:19264728

Laser-zone growth in a Ribbon-To-Ribbon (RTR) process, silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.

1976-01-01

The objective of this research is to fully investigate the Ribbon-To-Ribbon (R-T-R) approach to silicon ribbon growth. Initial work has concentrated on modification and characterization of an existing R-T-R apparatus. In addition, equipment for auxiliary heating of the melt is being evaluated and acquired. Modification of the remote viewing system and mechanical staging are nearly complete. Characterization of the laser and other components is in progress and several auxiliary heating techniques are being investigated.

Elasticity and Fluctuations of Frustrated Nanoribbons

NASA Astrophysics Data System (ADS)

Grossman, Doron; Sharon, Eran; Diamant, Haim

2016-06-01

We derive a reduced quasi-one-dimensional theory of geometrically frustrated elastic ribbons. Expressed in terms of geometric properties alone, it applies to ribbons over a wide range of scales, allowing the study of their elastic equilibrium, as well as thermal fluctuations. We use the theory to account for the twisted-to-helical transition of ribbons with spontaneous negative curvature and the effect of fluctuations on the corresponding critical exponents. The persistence length of such ribbons changes nonmonotonically with the ribbon's width, dropping to zero at the transition. This and other statistical properties qualitatively differ from those of nonfrustrated fluctuating filaments.

Amorphous ribbon transducers

NASA Astrophysics Data System (ADS)

Meydan, T.; Overshott, K. J.

1984-02-01

Amorphous ribbon transducers have been investigated which consist of toroidally wound amorphous ribbon with a primary (magnetizing) winding and secondary (search coil) windings. The application of a force to the ribbon gives a linear search coil voltage against applied force characteristic. The positioning of the windings with respect to the applied force has been studied, and it is shown that the effect of the applied force is localized. Domain studies have shown that the applied force produces domain wall motion which can be correlated to the performance. These results have elucidated the operation of ac amorphous ribbon transducers and enabled improved designs to be produced.

Using finite element modelling and experimental methods to investigate planar coil sensor topologies for inductive measurement of displacement

NASA Astrophysics Data System (ADS)

Moreton, Gregory; Meydan, Turgut; Williams, Paul

2018-04-01

The usage of planar sensors is widespread due to their non-contact nature and small size profiles, however only a few basic design types are generally considered. In order to develop planar coil designs we have performed extensive finite element modelling (FEM) and experimentation to understand the performance of different planar sensor topologies when used in inductive sensing. We have applied this approach to develop a novel displacement sensor. Models of different topologies with varying pitch values have been analysed using the ANSYS Maxwell FEM package, furthermore the models incorporated a movable soft magnetic amorphous ribbon element. The different models used in the FEM were then constructed and experimentally tested with topologies that included mesh, meander, square coil, and circular coil configurations. The sensors were used to detect the displacement of the amorphous ribbon. A LabView program controlled both the displacement stage and the impedance analyser, the latter capturing the varying inductance values with ribbon displacement. There was good correlation between the FEM models and the experimental data confirming that the methodology described here offers an effective way for developing planar coil based sensors with improved performance.

Design, fabrication and test of prototype furnace for continuous growth of wide silicon ribbon

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.

1975-01-01

Progress is reported during the apparatus design, fabrication, and assembly phases of a program to grow wide, thin silicon dendritic web. The growth facility was essentially completed with any significant problems arising. A complete set of detailed fabrication drawings is included as an appendix.

Numerical Simulation Of Silicon-Ribbon Growth

NASA Technical Reports Server (NTRS)

Woda, Ben K.; Kuo, Chin-Po; Utku, Senol; Ray, Sujit Kumar

1987-01-01

Mathematical model includes nonlinear effects. In development simulates growth of silicon ribbon from melt. Takes account of entire temperature and stress history of ribbon. Numerical simulations performed with new model helps in search for temperature distribution, pulling speed, and other conditions favoring growth of wide, flat, relatively defect-free silicon ribbons for solar photovoltaic cells at economically attractive, high production rates. Also applicable to materials other than silicon.

76 FR 35379 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island, SC...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-17

..., Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island, SC; Danger Zone AGENCY... use these portions of Archers Creek, Ribbon Creek, and the Broad River when the rifle and pistol.... 334.480 to read as follows: Sec. 334.480 Archers Creek, Ribbon Creek, and Broad River; U.S. Marine...

Guidelines for safe work practices in human and animal medical diagnostic laboratories. Recommendations of a CDC-convened, Biosafety Blue Ribbon Panel.

PubMed

Miller, J Michael; Astles, Rex; Baszler, Timothy; Chapin, Kimberle; Carey, Roberta; Garcia, Lynne; Gray, Larry; Larone, Davise; Pentella, Michael; Pollock, Anne; Shapiro, Daniel S; Weirich, Elizabeth; Wiedbrauk, Danny

2012-01-06

Prevention of injuries and occupational infections in U.S. laboratories has been a concern for many years. CDC and the National Institutes of Health addressed the topic in their publication Biosafety in Microbiological and Biomedical Laboratories, now in its 5th edition (BMBL-5). BMBL-5, however, was not designed to address the day-to-day operations of diagnostic laboratories in human and animal medicine. In 2008, CDC convened a Blue Ribbon Panel of laboratory representatives from a variety of agencies, laboratory organizations, and facilities to review laboratory biosafety in diagnostic laboratories. The members of this panel recommended that biosafety guidelines be developed to address the unique operational needs of the diagnostic laboratory community and that they be science based and made available broadly. These guidelines promote a culture of safety and include recommendations that supplement BMBL-5 by addressing the unique needs of the diagnostic laboratory. They are not requirements but recommendations that represent current science and sound judgment that can foster a safe working environment for all laboratorians. Throughout these guidelines, quality laboratory science is reinforced by a common-sense approach to biosafety in day-to-day activities. Because many of the same diagnostic techniques are used in human and animal diagnostic laboratories, the text is presented with this in mind. All functions of the human and animal diagnostic laboratory--microbiology, chemistry, hematology, and pathology with autopsy and necropsy guidance--are addressed. A specific section for veterinary diagnostic laboratories addresses the veterinary issues not shared by other human laboratory departments. Recommendations for all laboratories include use of Class IIA2 biological safety cabinets that are inspected annually; frequent hand washing; use of appropriate disinfectants, including 1:10 dilutions of household bleach; dependence on risk assessments for many activities; development of written safety protocols that address the risks of chemicals in the laboratory; the need for negative airflow into the laboratory; areas of the laboratory in which use of gloves is optional or is recommended; and the national need for a central site for surveillance and nonpunitive reporting of laboratory incidents/exposures, injuries, and infections.

Modified Withdrawal Slot Increases Silicon Production

NASA Technical Reports Server (NTRS)

Piotrowsky, P. A.; Duncan, C. S.

1988-01-01

New shape reduces ribbon breakage and resulting idle time. Shape for slot through which single-crystal silicon ribbon pulled from melt increases productivity. Reduces tendency of emerging ribbon to grow thin and break.

Tree Waves Upward Migration in the Altai Mountains, Siberia

NASA Astrophysics Data System (ADS)

Kharuk, Viacheslav; Im, Sergei; Dvinskaya, Maria; Petrov, Il'ya

2017-04-01

The phenomenon of "tree waves" (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberian pine (Pinus sibirica) forms hedges on windward slopes and ribbons on the leeward ones. Hedges were formed by prevailing winds and oriented along winds direction. Ribbons were formed by snow blowing and accumulating on the leeward slope and perpendicular to the prevailing winds, as well as to the elevation gradient. Hedges were always linked with microtopography features, whereas ribbons were not. Trees are migrating upward by waves and new ribbons and hedges are forming at or near tree line, whereas at lower elevations ribbons and hedges are being transformed into closed forests. Time series of high-resolution satellite scenes (from 1968 to 2010) indicated an upslope shift in the position ribbons averaged 155±26 m (or 3.7 m yr -1) and crown closure increased (about 35-90%). The hedges advance was limited by poor regeneration establishment and was negligible. Regeneration within the "ribbon zone" was approximately 2.5 times (5060 vs 2120 ha -1) higher then within the "hedges zone". During the last four decades, Siberian pine in both hedges and ribbons strongly increased its growth increment and recent tree growth rate for 50 year old trees was about twice higher than recorded for similarly aged trees at the beginning of the 20th century. Growth increment increase was strongly correlated with CO2 concentration in the ambient air (R2 = 0.9), which may indicated CO2- fertilization. Hedges and ribbons are phenomena that are widespread within the southern and northern Siberian Mountains

Skills Today for Advancement Tomorrow (STAT). A National Workplace Literacy Partnership. Final Performance Report.

ERIC Educational Resources Information Center

Saint Louis Community Coll., MO.

The 18-month Skills Today for Advancement Tomorrow (STAT) program, a partnership among St. Louis Community College, the St. Louis Public Schools' Adult Basic Education Program, and Blue Cross and Blue Shield of Missouri, had the following objectives: (1) provide counseling and training for 370 current Blue Cross and Blue Shield workers; (2)…

KSC-03PD-2451

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. Daniel L. Tweed, with the Facilities Division, NASA Spaceport Services, addresses attendees at the ribbon cutting for the KSC Security gates. Tweed was project manager. The two new Security gates on Kennedy Parkway (Gate 2) and NASA Parkway (Gate 3) were activated Aug. 1, allowing the general public to have access to the new Space Commerce Way, which will provide access to the Research Park and KSC Visitor Complex, and providing an alternate route for the general public between Titusville and Merritt Island that is accessible 24 hours a day. The gates are staffed 24 hours daily. Others taking part in the ribbon cutting were Center Director Jim Kennedy; Chief, Protective & Safe Guards Office, Calvin L. Burch; SGS Deputy Program Manager William A. Sample; and Bobby Porter, with Oneida Construction.

The preparation and hydrogen brittleness resistance of Pd71.5Cu12Si16.5 metallic glass ribbons

NASA Astrophysics Data System (ADS)

Du, Xiaoqing; Ye, Xiaoqiu; Ren, Qingbo

2017-12-01

Pd71.5Cu12Si16.5 metallic glass ribbons as wide as 10mm were prepared by splat quenching. Structure was identified with X-ray diffraction (XRD) spectrums from the conventional X-ray diffractometer and also short wavelength X-ray stress analyzer. The results confirm fully amorphous structure of the ribbons. Multiple H2 adsorption and desorption cycles under a pressure of 100kPa were carried out in the metallic glass ribbon and also pure palladium membrane for comparison. The former didn’t show any cracks after more than 10 cycles, and thermal desorption spectroscopy (TDS) measurement confirms that hydrogen was adsorbed abundantly in the metallic glass ribbon. Pd71.5Cu12Si16.5 metallic glass ribbons demonstrate excellent hydrogen brittleness resistance.

Laser-zone growth in a Ribbon-To-Ribbon (RTR) process. Silicon sheet growth development for the large area sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Baghdadi, A.; Gurtler, R. W.; Legge, R.; Sopori, B.; Ellis, R. J.

1978-01-01

A new calculation of the effects of thermal stresses during growth on silicon ribbon quality is reported. Thermal stress distributions are computed for ribbon growth under a variety of temperature profiles. A growth rate of 55 cu cm/min with a single ribbon was achieved. The growth of RTR ribbon with a fairly uniform parallel dendritic structure was demonstrated. Results with two approaches were obtained for reducing the Mo impurity level in polycrystalline feedstock. Coating the Mo substrate with Si3N4 does not effect thermal shear separation of the polyribbon; this process shows promise of improving cell efficiency and also increasing the useful life of the molybdenum substrate. A number of solar cells were fabricated on RTR silicon grown from CVD feedstock.

Electronic properties and mechanical strength of β-phosphorene nano-ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok, E-mail: ashok@cup.ac.in

We have performed first principles calculations to find out the effect of mechanical strain on the electronic properties of zig-zag edged nano ribbons of β-phosphorene. It is found that electronic band-gap get opened-up to 2.61 eV by passivation of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75 GPa to 2.65 GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The band-gap value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable properties ofmore » β-phospherene with passivation with H-atom and applying mechanical strain offer its use in tunable nano electronics.« less

Elongation of Flare Ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu, Jiong; Longcope, Dana W.; Cassak, Paul A.

2017-03-20

We present an analysis of the apparent elongation motion of flare ribbons along the polarity inversion line (PIL), as well as the shear of flare loops in several two-ribbon flares. Flare ribbons and loops spread along the PIL at a speed ranging from a few to a hundred km s{sup −1}. The shear measured from conjugate footpoints is consistent with the measurement from flare loops, and both show the decrease of shear toward a potential field as a flare evolves and ribbons and loops spread along the PIL. Flares exhibiting fast bidirectional elongation appear to have a strong shear, whichmore » may indicate a large magnetic guide field relative to the reconnection field in the coronal current sheet. We discuss how the analysis of ribbon motion could help infer properties in the corona where reconnection takes place.« less

Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

DOEpatents

Goyal, Amit [Knoxville, TN

2012-07-24

A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

DOEpatents

Goyal, Amit

2013-07-09

A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Observations and Numerical Modeling of the Jovian Ribbon

NASA Technical Reports Server (NTRS)

Cosentino, R. G.; Simon, A.; Morales-Juberias, R.; Sayanagi, K. M.

2015-01-01

Multiple wavelength observations made by the Hubble Space Telescope in early 2007 show the presence of a wavy, high-contrast feature in Jupiter's atmosphere near 30 degrees North. The "Jovian Ribbon," best seen at 410 nanometers, irregularly undulates in latitude and is time-variable in appearance. A meridional intensity gradient algorithm was applied to the observations to track the Ribbon's contour. Spectral analysis of the contour revealed that the Ribbon's structure is a combination of several wavenumbers ranging from k equals 8-40. The Ribbon is a dynamic structure that has been observed to have spectral power for dominant wavenumbers which vary over a time period of one month. The presence of the Ribbon correlates with periods when the velocity of the westward jet at the same location is highest. We conducted numerical simulations to investigate the stability of westward jets of varying speed, vertical shear, and background static stability to different perturbations. A Ribbon-like morphology was best reproduced with a 35 per millisecond westward jet that decreases in amplitude for pressures greater than 700 hectopascals and a background static stability of N equals 0.005 per second perturbed by heat pulses constrained to latitudes south of 30 degrees North. Additionally, the simulated feature had wavenumbers that qualitatively matched observations and evolved throughout the simulation reproducing the Jovian Ribbon's dynamic structure.

Silicon ribbon growth by a capillary action shaping technique

NASA Technical Reports Server (NTRS)

Schwuttke, G. H.; Ciszek, T. F.; Kran, A.

1976-01-01

The technique of silicon ribbon growth by the capillary action shaping is assessed for applicability to photovoltaic power device material. Ribbons 25 mm in width and up to 0.5 m in length have been grown from SiC dies, and some new characteristics of growth from such dies have been identified. Thermal modifiers have been studied, and systems were developed which reduce the frozen-in stress un silicon ribbons and improve the thickness uniformity of the ribbons. Preliminary spreading resistance measurements indicate that neither surface striations nor twin boundaries give rise to appreciable resistivity variations, but that large-angle grain boundaries cause local resistivity increases of up to 200%.

Propulsion and hydrodynamic particle transport of magnetically twisted colloidal ribbons

NASA Astrophysics Data System (ADS)

Massana-Cid, Helena; Martinez-Pedrero, Fernando; Navarro-Argemí, Eloy; Pagonabarraga, Ignacio; Tierno, Pietro

2017-10-01

We describe a method to trap, transport and release microscopic particles in a viscous fluid using the hydrodynamic flow field generated by a magnetically propelled colloidal ribbon. The ribbon is composed of ferromagnetic microellipsoids that arrange with their long axis parallel to each other, a configuration that is energetically favorable due to their permanent magnetic moments. We use an external precessing magnetic field to torque the anisotropic particles forming the ribbon, and to induce propulsion of the entire structure due to the hydrodynamic coupling with the close substrate. The propulsion speed of the ribbon can be controlled by varying the driving frequency, or the amplitude of the precessing field. The latter parameter is also used to reduce the average inter particle distance and to induce the twisting of the ribbon due to the increase in the attraction between the rotating ellipsoids. Furthermore, non magnetic particles are attracted or repelled with the hydrodynamic flow field generated by the propelling ribbon. The proposed method may be used in channel free microfluidic applications, where the precise trapping and transport of functionalized particles via non invasive magnetic fields is required.

Fabrication of an ideal nanoring from a black phosphorus nanoribbon upon movable bundling carbon nanotubes

NASA Astrophysics Data System (ADS)

Cai, Kun; Shi, Jiao; Liu, Lingnan; Qin, Qing H.

2017-09-01

As a low dimensional material, black phosphorus (BP) continues to attract much attention from researchers due to its excellent electric properties. In particular, the one-dimensional material, in the form of a ring or tube formed from BP, has been extensively studied and found to be a perfect semiconductor. But the BP ring has never been reported in laboratories. To form an ideal ring from a rectangular BP ribbon, we choose a carbon nanotube (CNT) bundle to attract the ribbon and move one or more CNTs in the bundle to induce the unsaturated ends of the BP ribbon to become covalently bonded. Numerical experiments are applied to BP ribbons with lengths either equal to, shorter, or longer than the perimeter of the CNT bundle, to investigate the formation of a BP ring. Experiments show that if one end of the BP ribbon is attracted by a CNT, moving the other CNTs away endows the ribbon with high probability of forming an ideal ring. The conclusions drawn from these results will benefit future in situ experiments involving forming a ring from a BP ribbon.

Polymorphism complexity and handedness inversion in serum albumin amyloid fibrils.

PubMed

Usov, Ivan; Adamcik, Jozef; Mezzenga, Raffaele

2013-12-23

Protein-based amyloid fibrils can show a great variety of polymorphic structures within the same protein precursor, although the origins of these structural homologues remain poorly understood. In this work we investigate the fibrillation of bovine serum albumin--a model globular protein--and we follow the polymorphic evolution by a statistical analysis of high-resolution atomic force microscopy images, complemented, at larger length scales, by concepts based on polymer physics formalism. We identify six distinct classes of coexisting amyloid fibrils, including flexible left-handed twisted ribbons, rigid right-handed helical ribbons and nanotubes. We show that the rigid fibrils originate from flexible fibrils through two diverse polymorphic transitions, first, via a single-fibril transformation when the flexible left-handed twisted ribbons turn into the helical left-handed ribbons, to finally evolve into nanotube-like structures, and second, via a double-fibril transformation when two flexible left-handed twisted ribbons wind together resulting in a right-handed twisted ribbon, followed by a rigid right-handed helical ribbon polymorphic conformation. Hence, the change in handedness occurs with an increase in the level of the fibril's structural organization.

KENNEDY SPACE CENTER, FLA. - Former astronaut James Lovell addresses the audience at a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

NASA Image and Video Library

2003-06-20

KENNEDY SPACE CENTER, FLA. - Former astronaut James Lovell addresses the audience at a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

Position of the IBEX ribbon as a key to understand its origin

NASA Astrophysics Data System (ADS)

Swaczyna, Pawel; Bzowski, Maciej; Sokół, Justyna M.; Christian, Eric R.; Funsten, Herbert O.; McComas, David J.; Schwadron, Nathan A.

2017-04-01

Observations of the energetic neutral atom (ENA) emission by the Interstellar Boundary Explorer (IBEX) allow for remote sensing of the plasma properties in heliosheath. The first IBEX results revealed an unexpected arc-like enhancement of the ENA flux in the sky, dubbed the IBEX ribbon. This discovery led to formulation of more than a dozen hypotheses on its origin. The emission source region proposed in these hypotheses span the heliospheric termination shock up to a hypothetical nearby interface between the Local Interstellar Cloud and a local bay in the Local Bubble. Among these hypotheses is the concept that the ribbon is produced by the secondary ENA mechanism, operating in the outer heliosheath. The observational strategy of IBEX allows observation of the same part of the sky from the opposite sides of the Sun every six months and thus provides parallax viewing with a baseline of 2 AU. After correcting the observations for the Compton-Getting effect and for gravitational deflection and radiation pressure, we use this parallax viewing to precisely determine the apparent position of the maximum flux associated with the ribbon. We find that the ribbon peak position differs semi-annually by an angle of 0.41±0.15 deg, which we interpret as the parallax effect. This angle corresponds to a distance of 140-38+84 AU, and thus suggests that most likely the ribbon's source is located just beyond the heliopause. Comparison of the IBEX ribbon position in five energy steps of IBEX-Hi shows a systematic shift, which changes the position of the ribbon center by ˜10 deg. We find that it can be explained using an analytic model of the secondary ENA mechanism with the neutralized supersonic solar wind as the source of the primary ENAs, which are ionized in the outer heliosheath, picked up by the ambient magnetic field, and eventually re-neutralized (as originally conceived, McComas et al. 2009). We use a realistic model of the solar wind evolution dependent on heliographic latitude, calculated the neutral solar wind flux and averaged it over the solar cycle, which was then used as the input in the analytic model of the secondary ENAs. The modeled ENA emission signal as observed at IBEX reproduces the observed features of the IBEX ribbon: the relative signal intensity along the ribbon in each energy channel and the shift of the ribbon center. The combination of the distance to the ribbon source obtained from parallax and the energy progression of the ribbon center location suggest that the secondary ENA mechanism is a plausible explanation for the ribbon origin. A better resolution of the ENA detectors expected on the IMAP mission will enable a more accurate determination of the ribbon's position and will extend observations to higher energies. In consequence, a better determination of its parallax should be possible, and time-dependent effects resulting from the evolution of the supersonic solar wind structure with time will provide additional, critical signatures of the ribbon origin.

Plastic deformation of silicon dendritic web ribbons during the growth

NASA Technical Reports Server (NTRS)

Cheng, L. J.; Dumas, K. A.; Su, B. M.; Leipold, M. H.

1984-01-01

The distribution of slip dislocations in silicon dendritic web ribbons due to plastic deformation during the cooling phase of the growth was studied. The results show the existence of two distinguishable stress regions across the ribbon formed during the plastic deformation stage, namely, shear stress at the ribbon edges and tensile stress at the middle. In addition, slip dislocations caused by shear stress near the edges appear to originate at the twin plane.

Electrostatics-Driven Hierarchical Buckling of Charged Flexible Ribbons.

PubMed

Yao, Zhenwei; Olvera de la Cruz, Monica

2016-04-08

We investigate the rich morphologies of an electrically charged flexible ribbon, which is a prototype for many beltlike structures in biology and nanomaterials. Long-range electrostatic repulsion is found to govern the hierarchical buckling of the ribbon from its initially flat shape to its undulated and out-of-plane twisted conformations. In this process, the screening length is the key controlling parameter, suggesting that a convenient way to manipulate the ribbon morphology is simply to change the salt concentration. We find that these shapes originate from the geometric effect of the electrostatic interaction, which fundamentally changes the metric over the ribbon surface. We also identify the basic modes by which the ribbon reshapes itself in order to lower the energy. The geometric effect of the physical interaction revealed in this Letter has implications for the shape design of extensive ribbonlike materials in nano- and biomaterials.

Thermally induced spin rate ripple on spacecraft with long radial appendages

NASA Technical Reports Server (NTRS)

Fedor, J. V.

1983-01-01

A thermally induced spin rate ripple hypothesis is proposed to explain the spin rate anomaly observed on ISEE-B. It involves the two radial 14.5 meter beryllium copper tape ribbons going in and out of the spacecraft hub shadow. A thermal lag time constant is applied to the thermally induced ribbon displacements which perturb the spin rate. It is inferred that the averaged thermally induced ribbon displacements are coupled to the ribbon angular motion. A possible exponential build up of the inplane motion of the ribbon which in turn causes the spin rate ripple, ultimately limited by damping in the ribbon and spacecraft is shown. It is indicated that qualitative increase in the oscillation period and the thermal lag is fundamental for the period increase. found that numerical parameter values required to agree with in orbit initial exponential build up are reasonable; those required for the ripple period are somewhat extreme.

Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

NASA Astrophysics Data System (ADS)

Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

2018-06-01

The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

Passive Diffusion as a Mechanism Underlying Ribbon Synapse Vesicle Release and Resupply

PubMed Central

Graydon, Cole W.; Zhang, Jun; Oesch, Nicholas W.; Sousa, Alioscka A.; Leapman, Richard D.

2014-01-01

Synaptic ribbons are presynaptic protein structures found at many synapses that convey graded, “analog” sensory signals in the visual, auditory, and vestibular pathways. Ribbons, typically anchored to the presynaptic membrane and surrounded by tethered synaptic vesicles, are thought to regulate or facilitate vesicle delivery to the presynaptic membrane. No direct evidence exists, however, to indicate how vesicles interact with the ribbon or, once attached, move along the ribbon's surface to reach the presynaptic release sites at its base. To address these questions, we have created, validated, and tested a passive vesicle diffusion model of retinal rod bipolar cell ribbon synapses. We used axial (bright-field) electron tomography in the scanning transmission electron microscopy to obtain 3D structures of rat rod bipolar cell terminals in 1-μm-thick sections of retinal tissue at an isotropic spatial resolution of ∼3 nm. The resulting structures were then incorporated with previously published estimates of vesicle diffusion dynamics into numerical simulations that accurately reproduced electrophysiologically measured vesicle release/replenishment rates and vesicle pool sizes. The simulations suggest that, under physiologically realistic conditions, diffusion of vesicles crowded on the ribbon surface gives rise to a flow field that enhances delivery of vesicles to the presynaptic membrane without requiring an active transport mechanism. Numerical simulations of ribbon–vesicle interactions predict that transient binding and unbinding of multiple tethers to each synaptic vesicle may achieve sufficiently tight association of vesicles to the ribbon while permitting the fast diffusion along the ribbon that is required to sustain high release rates. PMID:24990916

Vesicle Pool Size at the Salamander Cone Ribbon Synapse

PubMed Central

Bartoletti, Theodore M.; Babai, Norbert

2010-01-01

Cone light responses are transmitted to postsynaptic neurons by changes in the rate of synaptic vesicle release. Vesicle pool size at the cone synapse constrains the amount of release and can thus shape contrast detection. We measured the number of vesicles in the rapidly releasable and reserve pools at cone ribbon synapses by performing simultaneous whole cell recording from cones and horizontal or off bipolar cells in the salamander retinal slice preparation. We found that properties of spontaneously occurring miniature excitatory postsynaptic currents (mEPSCs) are representative of mEPSCs evoked by depolarizing presynaptic stimulation. Strong, brief depolarization of the cone stimulated release of the entire rapidly releasable pool (RRP) of vesicles. Comparing charge transfer of the EPSC with mEPSC charge transfer, we determined that the fast component of the EPSC reflects release of ∼40 vesicles. Comparing EPSCs with simultaneous presynaptic capacitance measurements, we found that horizontal cell EPSCs constitute 14% of the total number of vesicles released from a cone terminal. Using a fluorescent ribeye-binding peptide, we counted ∼13 ribbons per cone. Together, these results suggest each cone contacts a single horizontal cell at ∼2 ribbons. The size of discrete components in the EPSC amplitude histogram also suggested ∼2 ribbon contacts per cell pair. We therefore conclude there are ∼20 vesicles per ribbon in the RRP, similar to the number of vesicles contacting the plasma membrane at the ribbon base. EPSCs evoked by lengthy depolarization suggest a reserve pool of ∼90 vesicles per ribbon, similar to the number of additional docking sites further up the ribbon. PMID:19923246

Oil Slick in the Gulf of Mexico May 24th View

NASA Image and Video Library

2017-12-08

NASA image acquired May 24, 2010 On May 24, 2010, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this false-color, high-resolution view of the very tip of the Mississippi River Delta. Ribbons and patches of oil that have leaked from the Deepwater Horizon well offshore are silver against the light blue color of the adjacent water. Vegetation is red. To learn more about this image go to: earthobservatory.nasa.gov/NaturalHazards/view.php?id=44078 To learn more about the oil spill go to: www.nasa.gov/topics/earth/features/oil-creep.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

The use of commercial off-the-shelf equipment and its impact on C3 (Command, Control and Communications EMP (electromagnetic pulse) survivability

NASA Astrophysics Data System (ADS)

Hoke, Melvin D., Jr.

1988-04-01

The President's Blue Ribbon Commission on Defense Management has recommended that the military should make greater use of off-the-shelf components, systems, and services (also know as Non-Developmental Items or NDI). This recommendation, if blindly implemented, could have an adverse impact on the survivability of critical command, control, and communications assets. The study evaluates how the electromagnetic pulse (EMP) survivability of a strategic, time-urgent, fixed, ground-based, Command, Control, and Communications (C3) facility would be impacted by the use of off-the-shelf C3 equipments. The study concludes that to have a quantifiable measure of confidence in the facility's EMP survivability, the piece of off-the-shelf equipment under consideration will first have to be subjected to some degree of EMP testing.

Preparing Solar Cells for Soldering

NASA Technical Reports Server (NTRS)

Hagerty, J. J.

1983-01-01

Solder paste and contact ribbon dispensed in synchronism. Solder-paste dispenser operates on one cell at a time. Ribbon fed up ramps and into positioned while solder paste is applied. When ramps are moved out of way, ribbon lies down onto cell.

Blue Guardian: open architecture intelligence, surveillance, and reconnaissance (ISR) demonstrations

NASA Astrophysics Data System (ADS)

Shirey, Russell G.; Borntrager, Luke A.; Soine, Andrew T.; Green, David M.

2017-04-01

The Air Force Research Laboratory (AFRL) - Sensors Directorate has developed the Blue Guardian program to demonstrate advanced sensing technology utilizing open architectures in operationally relevant environments. Blue Guardian has adopted the core concepts and principles of the Air Force Rapid Capabilities Office (AFRCO) Open Mission Systems (OMS) initiative to implement an open Intelligence, Surveillance and Reconnaissance (ISR) platform architecture. Using this new OMS standard provides a business case to reduce cost and program schedules for industry and the Department of Defense (DoD). Blue Guardian is an early adopting program of OMS and provides much needed science and technology improvements, development, testing, and implementation of OMS for ISR purposes. This paper presents results and lessons learned under the Blue Guardian Project Shepherd program which conducted Multi-INT operational demonstrations in the Joint Interagency Task Force - South (JIATF-S) and USSOUTHCOM area of operations in early 2016. Further, on-going research is discussed to enhance Blue Guardian Multi-INT ISR capabilities to support additional mission sets and platforms, including unmanned operations over line of sight (LOS) and beyond line of sight (BLOS) datalinks. An implementation of additional OMS message sets and services to support off-platform sensor command and control using OMS/UCI data structures and dissemination of sensor product data/metadata is explored. Lastly, the Blue Guardian team is working with the AgilePod program to use OMS in a full Government Data Rights Pod to rapidly swap these sensors to different aircraft. The union of the AgilePod (which uses SOSA compliant standards) and OMS technologies under Blue Guardian programs is discussed.

Electronic and transport properties of 1D aluminum at atomic scale

NASA Astrophysics Data System (ADS)

Bhuyan, Prabal Dev; Gupta, Sanjeev K.; Sonvane, Yogesh; Kumar, Ashok

2018-04-01

In this paper, we have studied the structural, electronic and transport properties of 1D carbyne like chain and ribbon like zigzag structures of aluminum (Al) nanowire. The ribbon with width of 4.79Å (2R) and 7.01Å (3R) shows better room temperature conductivity i.e. 3.50×1019 (Ω m s)-1 and 3.91×1019 (Ω m s)-1 respectively. We have observed that Al chain conducts better than Al ribbon; however the conductivity for the ribbon can be enhanced by increasing the width. On the other hand, higher thermal conductivity has been found to possess Al ribbon (3R) structure.

Advanced dendritic web growth development

NASA Technical Reports Server (NTRS)

Hopkins, R. H.

1985-01-01

A program to develop the technology of the silicon dendritic web ribbon growth process is examined. The effort is being concentrated on the area rate and quality requirements necessary to meet the JPL/DOE goals for terrestrial PV applications. Closed loop web growth system development and stress reduction for high area rate growth is considered.

Learning Where They Teach

ERIC Educational Resources Information Center

Robelen, Erik W.

2007-01-01

In 2004, High Tech High, a charter school chain based in San Diego, California, became the state's first charter-management organization (CMO) to gain state approval to operate its own teacher-credentialing program. It is not stopping there. In August, it will cut the ribbon on the High Tech High graduate school of education, which appears to be…

Biomedical wellness standoff screening by unsupervised learning

NASA Astrophysics Data System (ADS)

Szu, Harold H.; Hsu, Charles; Hoekstra, Philip; Beeney, Jerry

2009-04-01

Biomedical Wellness (BMW) surveillance system may become indispensible in public health riding on four confluent trends: (i) The surge of retirement waves of WWII baby boomers; (ii) The longevity of the seniors, thanks to 3 decades steady NIH budgets 23B per year; (iii) The economic melting down is exasperating resources for entitlements; (iv) The emergent Next Gen Internet having the last mile challenges solved entirely and friendly with IT wired and wireless delivery system, thanks to DoD/DARPA pioneer and numerous entrepreneurs visionary efforts. To be effective in job recreation in current economic slag, BMW needs a jump start, WH/HHS should establish a balanced investment policy in health care, not just to illness but to wellness, and a BMW blue ribbon panel (BMWbrp), which must be, however, independent of NIHbrp, recommending additional resources, say 5B budget for BMW infrastructure building that will surely create new jobs to prepare badly needed geriatric caretakers. Being governmental investment, the BMWbrp must come back with a upward-conversion compatible infrastructure Blue-Print, version#1, an open architecture of standard interfaces, workable with distributed data bases and programming languages. The infrastructure must be simple, transparent, scalable, to leverage with a win-win-win(senior) CRADA from the private investments worldwide, e.g. from the insurance companies and home security companies, etc. that can further attract senior community center BOT. To start whenever the rubber meets the road, we shall enlist the military infrastructure, their sensors suite located in DoD & DHS labs supported with their affiliated contractors and universities. However, the down selections should be done under open bids, oversight by BMWbrp, under HHS $5B budget, to translate their sophisticated military persistent and precision surveillance know-how technology to watch out, no longer the enemy of USA but also, the enemy of mankind, the malicious microorganisms and disorders. The degree of friendliness must be demanded and measured by the standoff methodology such as 4 nones: noninvasive, noncontact, and none-stop-to-measure, in this order.

Neuraminidase Ribbon Diagram

NASA Technical Reports Server (NTRS)

2004-01-01

Ribbons is a program developed at UAB used worldwide to graphically depict complicated protein structures in a simplified format. The program uses sophisticated computer systems to understand the implications of protein structures. The Influenza virus remains a major causative agent for a large number of deaths among the elderly and young children and huge economic losses due to illness. Finding a cure will have a general impact both on the basic research of viral pathologists of fast evolving infectious agents and clinical treatment of influenza virus infection. The reproduction process of all strains of influenza are dependent on the same enzyme neuraminidase. Shown here is a segmented representation of the neuraminidase inhibitor compound sitting inside a cave-like contour of the neuraminidase enzyme surface. This cave-like formation present in every neuraminidase enzyme is the active site crucial to the flu's ability to infect. The space-grown crystals of neuraminidase have provided significant new details about the three-dimensional characteristics of this active site thus allowing researchers to design drugs that fit tighter into the site. Principal Investigator: Dr. Larry DeLucas

Magnetic properties enhancement of melt spun CoZrB ribbons by elemental substitutions

NASA Astrophysics Data System (ADS)

Chang, H. W.; Tsai, C. F.; Hsieh, C. C.; Shih, C. W.; Chang, W. C.; Shaw, C. C.

2013-11-01

Effect of elemental substitution of M (M=C, Cu, Ga, Al and Si) for Zr on the magnetic properties, phase evolution, and microstructure of melt spun Co80Zr18-xMxB2 (x=0-2) ribbons have been investigated. The x-ray diffraction (XRD) and thermal magnetic analysis (TMA) results showed that two magnetically soft phases, namely fcc-Co and Co23Zr6, coexisted with hard phase Co5Zr in Co80Zr17M1B2 ribbons with M=Cu, Ga, Al and Si, while an extra unknown magnetic phase was present in ribbons with M=C. The ribbons with M=C and Si were found to improve the remanence (σr) of the Co80Zr17M1B2 ribbons. However, only M=Si could improve the whole magnetic properties, including Br, intrinsic coercivity (iHc) and energy product ((BH)max) of the above ribbons. The optimal magnetic properties of Br=5.2 kG, iHc=4.5 kOe, and (BH)max=5.3 MGOe were obtained in Co80Zr17Si1B2 ribbons, which possessed Co5Zr and minor fcc-Co phases with much finer grain size (10-30 nm) in comparison with its counterpart Co80Zr18B2 (20-60 nm).

Continuous-annealing method for producing a flexible, curved, soft magnetic amorphous alloy ribbon

NASA Astrophysics Data System (ADS)

Francoeur, Bruno; Couture, Pierre

2012-04-01

A method has been developed for continuous annealing of an amorphous alloy ribbon moving forward at several meters per second, giving a curved shape to the ribbon that remains flexible afterward and can be easily wound into a toroidal core with excellent soft magnetic properties. A heat pulse was applied by a compact system on a Metglas 2605HB1 ribbon moving forward at 5 m/s to initiate a thermal treatment at 460 °C, near crystallization onset. The treatment duration was less than 0.1 s, and the heating and cooling rates were above 10 000 °C/s, which helped preserve most of the alloy as-cast ductility state. Such high temperature rates were achieved by forcing a static contact between the moving ribbon and a temperature-controlled roller. A tensile stress and a series of bending configurations were applied on the moving ribbon during the treatment to induce the development of magnetic anisotropy and to obtain the desired natural curvature radius. The core losses at 60 Hz of a toroidal test core wound with the resulting ribbon are lower than the specific values reported by the alloy manufacturer. This method can be implemented at the casting plant for supplying a low-cost, ready-to-use ribbon, easy to handle and cut, for mass production of toroidal cores for distribution transformer kernels (core and coil only), pulse power cores, etc.

Contoured Orifice for Silicon-Ribbon Die

NASA Technical Reports Server (NTRS)

Mackintosh, B. H.

1985-01-01

Die configuration encourages purity and stable growth. Contour of die orifice changes near ribbon edges. As result, silicon ribbon has nearly constant width and little carbon contamination. Die part of furnace being developed to produce high-quality, low-cost material for solar cells.

The Disease Protein Tulp1 Is Essential for Periactive Zone Endocytosis in Photoreceptor Ribbon Synapses

PubMed Central

Wahl, Silke; Magupalli, Venkat Giri; Dembla, Mayur; Katiyar, Rashmi; Schwarz, Karin; Köblitz, Louise; Alpadi, Kannan; Krause, Elmar; Rettig, Jens; Sung, Ching-Hwa; Goldberg, Andrew F. X.

2016-01-01

Mutations in the Tulp1 gene cause severe, early-onset retinitis pigmentosa (RP14) in humans. In the retina, Tulp1 is mainly expressed in photoreceptors that use ribbon synapses to communicate with the inner retina. In the present study, we demonstrate that Tulp1 is highly enriched in the periactive zone of photoreceptor presynaptic terminals where Tulp1 colocalizes with major endocytic proteins close to the synaptic ribbon. Analyses of Tulp1 knock-out mice demonstrate that Tulp1 is essential to keep endocytic proteins enriched at the periactive zone and to maintain high levels of endocytic activity close to the synaptic ribbon. Moreover, we have discovered a novel interaction between Tulp1 and the synaptic ribbon protein RIBEYE, which is important to maintain synaptic ribbon integrity. The current findings suggest a new model for Tulp1-mediated localization of the endocytic machinery at the periactive zone of ribbon synapses and offer a new rationale and mechanism for vision loss associated with genetic defects in Tulp1. SIGNIFICANCE STATEMENT Mutations in the Tulp1 gene cause severe, early-onset retinitis pigmentosa (RP14) and Leber congenital amaurosis (LCA15) in human patients. In this study, we discovered that the phosphoinositol-4,5-bisphosphate-binding protein Tulp1 is essential for the structural and functional organization of the periactive zone in photoreceptor synapses. Using Tulp1 knock-out mice, we found that Tulp1 is required to enrich major endocytic proteins at the periactive zone next to the synaptic ribbon. We demonstrate that Tulp1 is needed to promote endocytic vesicle retrieval at the periactive zone. Moreover, we discovered a novel interaction between Tulp1 and the synaptic ribbon protein RIBEYE. This newly discovered disease-sensitive interaction provides a molecular model for the control of endocytosis close to the synaptic ribbon. PMID:26911694

Evolutionary analysis of a novel zinc ribbon in the N-terminal region of threonine synthase.

PubMed

Kaur, Gurmeet; Subramanian, Srikrishna

2017-10-18

Threonine synthase (TS) catalyzes the terminal reaction in the biosynthetic pathway of threonine and requires pyridoxal phosphate as a cofactor. TSs share a common catalytic domain with other fold type II PALP dependent enzymes. TSs are broadly grouped into two classes based on their sequence, quaternary structure, and enzyme regulation. We report the presence of a novel zinc ribbon domain in the N-terminal region preceding the catalytic core in TS. The zinc ribbon domain is present in TSs belonging to both classes. Our sequence analysis reveals that archaeal TSs possess all zinc chelating residues to bind a metal ion that are lacking in the structurally characterized homologs. Phylogenetic analysis suggests that TSs with an N-terminal zinc ribbon likely represents the ancestral state of the enzyme while TSs without a zinc ribbon must have diverged later in specific lineages. The zinc ribbon and its N- and C-terminal extensions are important for enzyme stability, activity and regulation. It is likely that the zinc ribbon domain is involved in higher order oligomerization or mediating interactions with other biomolecules leading to formation of larger metabolic complexes.

Preventing Freezeup in Silicon Ribbon Growth

NASA Technical Reports Server (NTRS)

Mackintosh, B.

1983-01-01

Carefully-shaped heat conductor helps control thermal gradients crucial to growth of single-crystal silicon sheets for solar cells. Ends of die through which silicon sheet is drawn as ribbon from molten silicon. Profiled heat extractor prevents ribbon ends from solidifying prematurely and breaking.

Carbon nanotube fiber spun from wetted ribbon

DOEpatents

Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

2014-04-29

A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

Decomposition of the linking number of a closed ribbon: A problem from molecular biology

PubMed Central

Fuller, F. Brock

1978-01-01

A closed duplex DNA molecule relaxed and containing nucleosomes has a different linking number from the same molecule relaxed and without nucleosomes. What does this say about the structure of the nucleosome? A mathematical study of this question is made, representing the DNA molecule by a ribbon. It is shown that the linking number of a closed ribbon can be decomposed into the linking number of a reference ribbon plus a sum of locally determined “linking differences.” PMID:16592550

Silicon ribbon growth by a capillary action shaping technique

NASA Technical Reports Server (NTRS)

Schwuttke, G. H.; Ciszek, T. F.; Kran, A.

1976-01-01

The crystal growth method described is a capillary action shaping technique. Meniscus shaping for the desired ribbon geometry occurs at the vertex of a wettable die. As ribbon growth depletes the melt meniscus, capillary action supplies replacement material. A capillary die is so designed that the bounding edges of the die top are not parallel or concentric with the growing ribbon. The new dies allow a higher melt meniscus with concomitant improvements in surface smoothness and freedom from SiC surface particles, which can degrade perfection.

Web-dendritic ribbon growth

NASA Technical Reports Server (NTRS)

Hilborn, R. B., Jr.; Faust, J. W., Jr.

1976-01-01

A web furnace was constructed for pulling dendritic-web samples. The effect of changes in the furnace thermal geometry on the growth of dendritic-web was studied. Several attempts were made to grow primitive dendrites for use as the dendritic seed crystals for web growth and to determine the optimum twin spacing in the dendritic seed crystal for web growth. Mathematical models and computer programs were used to determine the thermal geometries in the susceptor, crucible melt, meniscus, and web. Several geometries were determined for particular furnace geometries and growth conditions. The information obtained was used in conjunction with results from the experimental growth investigations in order to achieve proper conditions for sustained pulling of two dendrite web ribbons. In addition, the facilities for obtaining the following data were constructed: twin spacing, dislocation density, web geometry, resistivity, majority charge carrier type, and minority carrier lifetime.

Onset of a Large Ejective Solar Eruption from a Typical Coronal-jet-base Field Configuration

NASA Astrophysics Data System (ADS)

Joshi, Navin Chandra; Sterling, Alphonse C.; Moore, Ronald L.; Magara, Tetsuya; Moon, Yong-Jae

2017-08-01

Utilizing multiwavelength observations and magnetic field data from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), SDO/Helioseismic and Magnetic Imager (HMI), the Geostationary Operational Environmental Satellite (GOES), and RHESSI, we investigate a large-scale ejective solar eruption of 2014 December 18 from active region NOAA 12241. This event produced a distinctive “three-ribbon” flare, having two parallel ribbons corresponding to the ribbons of a standard two-ribbon flare, and a larger-scale third quasi-circular ribbon offset from the other two. There are two components to this eruptive event. First, a flux rope forms above a strong-field polarity inversion line and erupts and grows as the parallel ribbons turn on, grow, and spread apart from that polarity inversion line; this evolution is consistent with the mechanism of tether-cutting reconnection for eruptions. Second, the eruption of the arcade that has the erupting flux rope in its core undergoes magnetic reconnection at the null point of a fan dome that envelops the erupting arcade, resulting in formation of the quasi-circular ribbon; this is consistent with the breakout reconnection mechanism for eruptions. We find that the parallel ribbons begin well before (˜12 minutes) the onset of the circular ribbon, indicating that tether-cutting reconnection (or a non-ideal MHD instability) initiated this event, rather than breakout reconnection. The overall setup for this large-scale eruption (diameter of the circular ribbon ˜105 km) is analogous to that of coronal jets (base size ˜104 km), many of which, according to recent findings, result from eruptions of small-scale “minifilaments.” Thus these findings confirm that eruptions of sheared-core magnetic arcades seated in fan-spine null-point magnetic topology happen on a wide range of size scales on the Sun.

The application of terahertz pulsed imaging in characterising density distribution of roll-compacted ribbons.

PubMed

Zhang, Jianyi; Pei, Chunlei; Schiano, Serena; Heaps, David; Wu, Chuan-Yu

2016-09-01

Roll compaction is a commonly used dry granulation process in pharmaceutical, fine chemical and agrochemical industries for materials sensitive to heat or moisture. The ribbon density distribution plays an important role in controlling properties of granules (e.g. granule size distribution, porosity and strength). Accurate characterisation of ribbon density distribution is critical in process control and quality assurance. The terahertz imaging system has a great application potential in achieving this as the terahertz radiation has the ability to penetrate most of the pharmaceutical excipients and the refractive index reflects variations in density and chemical compositions. The aim of this study is to explore whether terahertz pulse imaging is a feasible technique for quantifying ribbon density distribution. Ribbons were made of two grades of microcrystalline cellulose (MCC), Avicel PH102 and DG, using a roll compactor at various process conditions and the ribbon density variation was investigated using terahertz imaging and section methods. The density variations obtained from both methods were compared to explore the reliability and accuracy of the terahertz imaging system. An average refractive index is calculated from the refractive index values in the frequency range between 0.5 and 1.5THz. It is shown that the refractive index gradually decreases from the middle of the ribbon towards to the edges. Variations of density distribution across the width of the ribbons are also obtained using both the section method and the terahertz imaging system. It is found that the terahertz imaging results are in excellent agreement with that obtained using the section method, demonstrating that terahertz imaging is a feasible and rapid tool to characterise ribbon density distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

Flexible cryogenic conduit

DOEpatents

Brindza, Paul Daniel; Wines, Robin Renee; Takacs, James Joseph

1999-01-01

A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

Microstructure, magnetic and magnetocaloric properties in Ni42.9Co6.9Mn38.3Sn11.9 alloy ribbons

NASA Astrophysics Data System (ADS)

Ma, S. C.; Ge, Q.; Yang, S.; Liu, K.; Han, X. Q.; Yu, K.; Song, Y.; Zhang, Z. S.; Jiang, Q. Z.; Chen, C. C.; Liu, R. H.; Zhong, Z. C.

2018-05-01

The microstructure, magnetic and magnetocaloric properties are investigated in the melt-spun and annealed Ni42.9Co6.9Mn38.3Sn11.9 ribbons. The columnar grains grow perpendicular to ribbon surfaces. After annealing, the grain size increases greatly. Meanwhile, the parent phase is suppressed and therefore L10 martensite predominates, indicating obvious shift of martensitic transformation to high temperature. More interestingly, the martensite variants are distinctly observed on the fractured cross-section of annealed ribbons, not just on the free surface in general. The significant enhancement of magnetic entropy change and effective refrigerant capacities with relatively smaller thermal hysteresis make annealed ribbons potential candidate in magnetic refrigeration around room temperature.

High speed shutter. [electrically actuated ribbon loop for shuttering optical or fluid passageways

NASA Technical Reports Server (NTRS)

Mcclenahan, J. O. (Inventor)

1974-01-01

A shutter element is described which is formed by a loop of an electrically conductive ribbon disposed adjacent to the end of a passageway to be shuttered. The shuttered end of the passageway is cut at an acute angle. The two leg portions of the ribbon loop are closely spaced to each other and disposed in a plane parallel to the axis of the passageway. A pulse of high current is switched through the loop to cause the current flowing in opposite directions through adjacent leg portions of the ribbon. This produces a magnetically induced pressure on one of the legs of the ribbon forcing the leg over the end of the passageway in gas tight sealing engagement, and thereby blocking passageway.

77 FR 15188 - Proposed Information Collection Activity Comment Request: Yellow Ribbon Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... Activity Comment Request: Yellow Ribbon Agreement AGENCY: Veterans Benefits Administration, Department of Veterans Affairs. ACTION: Notice. SUMMARY: The Veterans Benefits Administration (VBA), Department of... institutions of higher learning (IHLs) will be participating in the Yellow Ribbon G. I. Education Enhancement...

Effect of heat treatment procedure on magnetic and magnetocaloric properties of Ni43Mn46In11 melt spun ribbons

NASA Astrophysics Data System (ADS)

Kaya, M.; Elerman, Y.; Dincer, I.

2018-07-01

The effect of heat treatment on the structural, magnetic and magnetocaloric properties of Ni43Mn46In11 melt-spun ribbons was systematically investigated using X-ray powder diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), magnetic force microscope (MFM) and magnetic measurements. From the XRD studies, tetragonal and cubic phases were detected at room temperature for as-spun, quenched and slow-cooled ribbons. Furthermore, it was observed, upon annealing martensite transition temperatures increased when compared to the as-spun ribbon. To avoid magnetic hysteresis losses in the vicinity of the structural transition region, the magnetic entropy changes-ΔS m of the investigated ribbons were evaluated from temperature-dependent magnetisation-M(T) curves on cooling for different applied magnetic fields. The maximum ΔS m value was found to be 6.79 J kg-1 K-1 for the quenched ribbon in the vicinity of structural transition region for a magnetic field change of 50 kOe.

Large Area Silicon Sheet by EFG. [quality control and productivity of edge-defined film-fed growth of ribbons

NASA Technical Reports Server (NTRS)

1979-01-01

Influences on ribbon quality which might be caused by various materials of construction which are used in the growth furnace were assessed. At the present level of ribbon quality, which has produced 8.5% to 9.5% efficient solar cells, no particular influence of any furnace part was detected. The experiments led to the suspicion that the general environment and the somewhat unoptimized materials handling procedures might be responsible for the current variations in ribbon quality and that, therefore, continuous work with this furnace under rather more stringent environmental conditions and operating procedures could perhaps improve materials quality to some extent. The work on the multiple furnace was continued with two multiple growth runs being performed. In these runs, the melt replenishment system performed poorly and extensive modifications to it were designed to make reliable melt feeding for five ribbon growth possible. Additional characterization techniques for wide ribbons, stress measurements, and growth dynamics experiments are reported.

Tuning conductivity in boron nanowire by edge geometry

NASA Astrophysics Data System (ADS)

Bhuyan, Prabal Dev; Gupta, Sanjeev K.; Sonvane, Yogesh; Gajjar, P. N.

2018-04-01

In present study, we have investigated electronic and temperature dependent transport properties of carbyne like linear chain and ribbon like zigzag structures of Boron (B) nanowire. The linear chain structure showed higher electric and thermal conductivity, as it is sp-hybridized, than its counterpart ribbon (R) structure. However the conductivity of ribbon structure increases with increases in width due to edge geometry effect. The ribbon (3R) structure showed high electric and thermal conductivity of 8.0×1019 1/Ω m s and 0.59×1015 W/ m K respectively. Interestingly we have observed that B linear chain showed higher thermal conductivity of 0.23×1015 W/ m K than its ribbon R and 2R structure above 600K. Because of high Seebeck co-efficient of boron chain and ribbon (R) structures at low temperature, they could find applications in thermoelectric sensors. Our results show that tuning conductivity property of boron nanowire could be of great interest in research for future electric connector in nanodevices.

Multiple EFG silicon ribbon technology as the basis for manufacturing low-cost terrestrial solar cells. [Epitaxial Film Growth

NASA Technical Reports Server (NTRS)

Mackintosh, B.; Kalejs, J. P.; Ho, C. T.; Wald, F. V.

1981-01-01

Mackintosh et al. (1978) have reported on the development of a multiple ribbon furnace based on the 'edge defined film fed growth' (EFG) process for the fabrication of silicon ribbon. It has been demonstrated that this technology can meet the requirements for a silicon substrate material to be used in the manufacture of solar panels which can meet requirements regarding a selling price of $0.70/Wp when certain goals in terms of throughput and quality are achieved. These goals for the multiple ribbon technology using 10 cm wide ribbon require simultaneous growth of 12 ribbons by one operator at average speeds of 4 to 4.5 cm/min, and 13% efficient solar cells. A description is presented of the progress made toward achieving these goals. It is concluded that the required performance levels have now been achieved. The separate aspects of technology must now be integrated into a single prototype furnace.

Mena–GRASP65 interaction couples actin polymerization to Golgi ribbon linking

PubMed Central

Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

2016-01-01

In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. PMID:26538023

ProteinShader: illustrative rendering of macromolecules

PubMed Central

Weber, Joseph R

2009-01-01

Background Cartoon-style illustrative renderings of proteins can help clarify structural features that are obscured by space filling or balls and sticks style models, and recent advances in programmable graphics cards offer many new opportunities for improving illustrative renderings. Results The ProteinShader program, a new tool for macromolecular visualization, uses information from Protein Data Bank files to produce illustrative renderings of proteins that approximate what an artist might create by hand using pen and ink. A combination of Hermite and spherical linear interpolation is used to draw smooth, gradually rotating three-dimensional tubes and ribbons with a repeating pattern of texture coordinates, which allows the application of texture mapping, real-time halftoning, and smooth edge lines. This free platform-independent open-source program is written primarily in Java, but also makes extensive use of the OpenGL Shading Language to modify the graphics pipeline. Conclusion By programming to the graphics processor unit, ProteinShader is able to produce high quality images and illustrative rendering effects in real-time. The main feature that distinguishes ProteinShader from other free molecular visualization tools is its use of texture mapping techniques that allow two-dimensional images to be mapped onto the curved three-dimensional surfaces of ribbons and tubes with minimum distortion of the images. PMID:19331660

SYMMETRY OF THE IBEX RIBBON OF ENHANCED ENERGETIC NEUTRAL ATOM (ENA) FLUX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Funsten, H. O.; Cai, D. M.; Higdon, D. M.

2015-01-20

The circular ribbon of enhanced energetic neutral atom (ENA) emission observed by the Interstellar Boundary Explorer (IBEX) mission remains a critical signature for understanding the interaction between the heliosphere and the interstellar medium. We study the symmetry of the ribbon flux and find strong, spectrally dependent reflection symmetry throughout the energy range 0.7-4.3 keV. The distribution of ENA flux around the ribbon is predominantly unimodal at 0.7 and 1.1 keV, distinctly bimodal at 2.7 and 4.3 keV, and a mixture of both at 1.7 keV. The bimodal flux distribution consists of partially opposing bilateral flux lobes, located at highest and lowest heliographic latitude extentsmore » of the ribbon. The vector between the ribbon center and heliospheric nose (which defines the so-called BV plane) appears to play an organizing role in the spectral dependence of the symmetry axis locations as well as asymmetric contributions to the ribbon flux. The symmetry planes at 2.7 and 4.3 keV, derived by projecting the symmetry axes to a great circle in the sky, are equivalent to tilting the heliographic equatorial plane to the ribbon center, suggesting a global heliospheric ordering. The presence and energy dependence of symmetric unilateral and bilateral flux distributions suggest strong spectral filtration from processes encountered by an ion along its journey from the source plasma to its eventual detection at IBEX.« less

Process Makes Thermoplastic Prepreg Ribbon

NASA Technical Reports Server (NTRS)

Wilson, Maywood L.; Johnson, Gary S.

1995-01-01

Manufacturing process produces ribbon of composite material (prepreg) consisting of continuous lengthwise fibers impregnated with thermoplastic resin. Ribbon can later be cut into sheets of required sizes and shapes, stacked, then heated under pressure to form composite-material structural components. Process accommodates variety of thermoplastic resins and variety of fibers.

A bill to amend title 38, United States Code, to extend the Yellow Ribbon G.I. Education Enhancement Program to cover recipients of Marine Gunnery Sergeant John David Fry scholarship, and for other purposes.

THOMAS, 113th Congress

Sen. Brown, Sherrod [D-OH

2013-03-11

Senate - 06/12/2013 Committee on Veterans' Affairs. Hearings held. Hearings printed: S.Hrg. 113-111. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Silicon ribbon stress/strain workshop

NASA Technical Reports Server (NTRS)

Leipold, M. H.

1985-01-01

Highlights of the Flat Plate Solar Array Project sponsored Silicon Ribbon Stress/Strain Workshop that was held 23 to 24 January 1985 are reported. The presentations and discussions were aimed at acquiring a generic understanding of the sources of stress, deformation, and structural characteristics occurring during the growth of silicon ribbon.

ON THE GEOMETRY OF THE IBEX RIBBON

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sylla, Adama; Fichtner, Horst

2015-10-01

The Energetic Neutral Atom (ENA) full-sky maps obtained with the Interstellar Boundary Explorer (IBEX) show an unexpected bright narrow band of increased intensity. This so-called ENA ribbon results from charge exchange of interstellar neutral atoms with protons in the outer heliosphere or beyond. Among other hypotheses it has been argued that this ribbon may be related to a neutral density enhancement, or H-wave, in the local interstellar medium. Here we quantitatively demonstrate, on the basis of an analytical model of the principal large-scale heliospheric structure, that this scenario for the ribbon formation leads to results that are fully consistent withmore » the observed location of the ribbon in the full-sky maps at all energies detected with high-energy sensor IBEX-Hi.« less

Effects of substitution of Mo for Nb on less-common properties of Finemet alloys

NASA Astrophysics Data System (ADS)

Butvin, P.; Butvinová, B.; Silveyra, J. M.; Chromčíková, M.; Janičkovič, D.; Sitek, J.; Švec, P.; Vlasák, G.

2010-10-01

Particular properties of Fe-Nb/Mo-Cu-B-Si rapidly quenched ribbons were examined. Apart from minor variation, no significant difference due to the Mo for Nb substitution was observed in alloy density and its annealing-induced changes. The same holds for the anisotropic thermal expansion of as-cast ribbon when annealed and for induced anisotropy when annealed under stress. The Mo-substituted ribbons show only slightly higher crystallinity and lower coercivity if annealed in inert gas ambience than in vacuum. Some diversity in surface to interior heterogeneity of the differently annealed ribbons can still be distinguished. Preserving a minor percentage of Nb together with Mo does not seem substantiated to obtain favorable soft magnetic properties of ribbons annealed in inert gas.

Variation of magnetic properties with mischmetal content in the resource saving magnets of MM-Fe-B ribbons

NASA Astrophysics Data System (ADS)

Li, Zhu-bai; Wang, Li-chen; Geng, Xiao-peng; Hu, Feng-xia; Sun, Ji-rong; Shen, Bao-gen

2017-03-01

Magnetic materials of MM-Fe-B (MM=mischmetal) ribbons were prepared using melt spinning method by varying the content of MM. The ribbons contain minor phases besides the main phase of Re2Fe14B. X-ray techniques show that the diffraction peak intensities of the minor phase Fe3B vary with the content of constituent elements, indicating that the amount of minor phase could be tunable. The squareness of hysteresis loop is the best in MM13Fe80.5B6.5 ribbons, which should mainly ascribe to the less amount of minor phase. Henkel plots verify the more uniform magnetization reversals in MM13Fe80.5B6.5 ribbons, and the energy product achieves to the maximum of 12.74 MGOe with the coercivity of 6.50 kOe. With the increase of MM content the coercivity increases monotonically, and reaches to 9.13 kOe in MM15Fe77.5B7.5 ribbons, which should be related with the nature of the defects in the main phase. These investigations show that optimizing the content of constituent elements and phase constitution could improve magnetic properties in the resource-saving magnets of MM-Fe-B ribbons.

Technical progress in silicon sheet growth under DOE/JPL FSA program, 1975-1986

NASA Technical Reports Server (NTRS)

Kalejs, J. P.

1986-01-01

The technical progress made in the Silicon Sheet Growth Program during its 11 years was reviewed. At present, in 1986, only two of the original 9 techniques have survived to the start-up, pilot-plant stage in industry. These two techniques are the edge-defined, film-fed growth (EFG) technique that produces closed shape polygons, and the WEB dendritic technique that produces single ribbons. Both the status and future concerns of the EFG and WEB techniques were discussed.

Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy.

PubMed

Colić, Miodrag; Rudolf, Rebeka; Stamenković, Dragoslav; Anzel, Ivan; Vucević, Dragana; Jenko, Monika; Lazić, Vojkan; Lojen, Gorazd

2010-01-01

Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.

The influence of API concentration on the roller compaction process: modeling and prediction of the post compacted ribbon, granule and tablet properties using multivariate data analysis.

PubMed

Boersen, Nathan; Carvajal, M Teresa; Morris, Kenneth R; Peck, Garnet E; Pinal, Rodolfo

2015-01-01

While previous research has demonstrated roller compaction operating parameters strongly influence the properties of the final product, a greater emphasis might be placed on the raw material attributes of the formulation. There were two main objectives to this study. First, to assess the effects of different process variables on the properties of the obtained ribbons and downstream granules produced from the rolled compacted ribbons. Second, was to establish if models obtained with formulations of one active pharmaceutical ingredient (API) could predict the properties of similar formulations in terms of the excipients used, but with a different API. Tolmetin and acetaminophen, chosen for their different compaction properties, were roller compacted on Fitzpatrick roller compactor using the same formulation. Models created using tolmetin and tested using acetaminophen. The physical properties of the blends, ribbon, granule and tablet were characterized. Multivariate analysis using partial least squares was used to analyze all data. Multivariate models showed that the operating parameters and raw material attributes were essential in the prediction of ribbon porosity and post-milled particle size. The post compacted ribbon and granule attributes also significantly contributed to the prediction of the tablet tensile strength. Models derived using tolmetin could reasonably predict the ribbon porosity of a second API. After further processing, the post-milled ribbon and granules properties, rather than the physical attributes of the formulation were needed to predict downstream tablet properties. An understanding of the percolation threshold of the formulation significantly improved the predictive ability of the models.

An academic, business, and community alliance to promote evidence-based public health policy: the case of primary seat belt legislation.

PubMed

Goldzweig, Irwin A; Schlundt, David G; Moore, Wayne E; Smith, Patricia E; Zoorob, Roger J; Levine, Robert S

2013-08-01

An academic, business, and community alliance comprising 285 organizations, including 43 national groups represented on a Blue Ribbon Panel organized by the U.S. Secretary of Transportation, targeted Arkansas, Florida, Mississippi, Minnesota, Tennessee, and Wisconsin for high involvement/intervention consisting of community organization and other political action to support passage of primary seat belt laws. State-level alliance activities began in January 2003. All six states enacted a primary seat belt law between 2004 and 2009. From January 2003 to May 2010, passage of primary legislation was 4.5 times as likely (95% CI 1.90, 10.68) in states with high versus low alliance involvement. Positive interaction between high alliance involvement and offers of federal incentives may have occurred as well. This evidence of success suggests that academic-business-community alliances for action to promote evidence-based public health policy may be effective.

Agility in adversity: Vaccines on Demand.

PubMed

De Groot, Anne S; Moise, Leonard; Olive, David; Einck, Leo; Martin, William

2016-09-01

Is the US ready for a biological attack using Ebola virus or Anthrax? Will vaccine developers be able to produce a Zika virus vaccine, before the epidemic spreads around the world? A recent report by The Blue Ribbon Study Panel on Biodefense argues that the US is not ready for these challenges, however, technologies and capabilities that could address these deficiencies are within reach. Vaccine technologies have advanced and readiness has improved in recent years, due to advances in sequencing technology and computational power making the 'vaccines on demand' concept a reality. Building a robust strategy to design effective biodefense vaccines from genome sequences harvested by real-time biosurveillance will benefit from technologies that are being brought to bear on the cancer cure 'moonshot'. When combined with flexible vaccine production platforms, vaccines on demand will relegate expensive and, in some cases, insufficiently effective vaccine stockpiles to the dust heap of history.

Can Sisyphus succeed? Getting U.S. high-level nuclear waste into a geological repository.

PubMed

North, D Warner

2013-01-01

The U.S. government has the obligation of managing the high-level radioactive waste from its defense activities and also, under existing law, from civilian nuclear power generation. This obligation is not being met. The January 2012 Final Report from the Blue Ribbon Commission on America's Nuclear Future provides commendable guidance but little that is new. The author, who served on the federal Nuclear Waste Technical Review Board from 1989 to 1994 and subsequently on the Board on Radioactive Waste Management of the National Research Council from 1994 to 1999, provides a perspective both on the Commission's recommendations and a potential path toward progress in meeting the federal obligation. By analogy to Sisyphus of Greek mythology, our nation needs to find a way to roll the rock to the top of the hill and have it stay there, rather than continuing to roll back down again. © 2012 Society for Risk Analysis.

75 FR 7244 - Narrow Woven Ribbons with Woven Selvedge from the People's Republic of China: Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

.... (``Guangzhou Complacent''); Ningbo Huarui Import & Export Co., Ltd.; Ningbo Jinfeng Thread & Ribbon Co. Ltd... limited to nylon, polyester, rayon, polypropylene, and polyethylene teraphthalate), metal threads and/or... 13) or rubber thread; (4) narrow woven ribbons of a kind used for the manufacture of typewriter or...

78 FR 10130 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

... Department selected two respondents for review, Precious Planet Ribbons & Bows Co., Ltd. (``Precious Planet'') and Hubschercorp. On January 24, 2012, Precious Planet timely withdrew its request for an...\\ See Letter from Precious Planet to the Secretary of Commerce, ``Narrow Woven Ribbons With Woven...

The silicon on dust substrate path to make solar cells directly from a gaseous feedstock

NASA Astrophysics Data System (ADS)

Serra, J M; Pinto, C R; Silva, J A; Brito, M C; Maia Alves, J; Vallêra, A M

2009-04-01

In this paper, we present a silicon on dust substrate (SDS) process, a new method for the growth of silicon ribbons. As a demonstration of the concept, we also present results on solar cells made of these new silicon ribbons. SDS ribbons were obtained directly from a gaseous feedstock by a fast CVD step using silane. The resulting self-supported intrinsic ribbons were microcrystalline and porous. To make these ribbon films suitable for photovoltaic applications, a novel recrystallization with an in situ doping step was developed. To this purpose, the ribbons were sprayed with boric acid and then recrystallized by float zone melting. Simple solar cells were prepared by employing: aluminium back contacts, Ti/Pd/Ag front grid contacts, with no anti-reflective coating, doping optimization, passivation or gettering. The 1-sun I-V characteristics of the cells were: Voc ~ 530 mV and Jsc ~ 24 mA cm-2. The minority carrier diffusion length obtained from a spectral response at long wavelengths gave values of Ln ~ 70 µm.

Non-Hookean statistical mechanics of clamped graphene ribbons

NASA Astrophysics Data System (ADS)

Bowick, Mark J.; Košmrlj, Andrej; Nelson, David R.; Sknepnek, Rastko

2017-03-01

Thermally fluctuating sheets and ribbons provide an intriguing forum in which to investigate strong violations of Hooke's Law: Large distance elastic parameters are in fact not constant but instead depend on the macroscopic dimensions. Inspired by recent experiments on free-standing graphene cantilevers, we combine the statistical mechanics of thin elastic plates and large-scale numerical simulations to investigate the thermal renormalization of the bending rigidity of graphene ribbons clamped at one end. For ribbons of dimensions W ×L (with L ≥W ), the macroscopic bending rigidity κR determined from cantilever deformations is independent of the width when W <ℓth , where ℓth is a thermal length scale, as expected. When W >ℓth , however, this thermally renormalized bending rigidity begins to systematically increase, in agreement with the scaling theory, although in our simulations we were not quite able to reach the system sizes necessary to determine the fully developed power law dependence on W . When the ribbon length L >ℓp , where ℓp is the W -dependent thermally renormalized ribbon persistence length, we observe a scaling collapse and the beginnings of large scale random walk behavior.

Highly conductive ribbons prepared by stick-slip assembly of organosoluble gold nanoparticles.

PubMed

Lawrence, Jimmy; Pham, Jonathan T; Lee, Dong Yun; Liu, Yujie; Crosby, Alfred J; Emrick, Todd

2014-02-25

Precisely positioning and assembling nanoparticles (NPs) into hierarchical nanostructures is opening opportunities in a wide variety of applications. Many techniques employed to produce hierarchical micrometer and nanoscale structures are limited by complex fabrication of templates and difficulties with scalability. Here we describe the fabrication and characterization of conductive nanoparticle ribbons prepared from surfactant-free organosoluble gold nanoparticles (Au NPs). We used a flow-coating technique in a controlled, stick-slip assembly to regulate the deposition of Au NPs into densely packed, multilayered structures. This affords centimeter-scale long, high-resolution Au NP ribbons with precise periodic spacing in a rapid manner, up to 2 orders-of-magnitude finer and faster than previously reported methods. These Au NP ribbons exhibit linear ohmic response, with conductivity that varies by changing the binding headgroup of the ligands. Controlling NP percolation during sintering (e.g., by adding polymer to retard rapid NP coalescence) enables the formation of highly conductive ribbons, similar to thermally sintered conductive adhesives. Hierarchical, conductive Au NP ribbons represent a promising platform to enable opportunities in sensing, optoelectronics, and electromechanical devices.

Wrinkles, loops, and topological defects in twisted ribbons

NASA Astrophysics Data System (ADS)

Chopin, Julien

Nature abounds with elastic ribbon like shapes including double-stranded semiflexible polymers, graphene and metal oxide nanoribbons which are examples of elongated elastic structures with a strongly anisotropic cross-section. Due to this specific geometry, it is far from trivial to anticipate if a ribbon should be considered as a flat flexible filament or a narrow thin plate. We thus perform an experiment in which a thin elastic ribbon is loaded using a twisting and traction device coupled with a micro X-ray computed tomography machine allowing a full 3D shape reconstruction. A wealth of morphological behaviors can be observed including wrinkled helicoids, curled and looped configurations, and faceted ribbons. In this talk, I will show that most morphologies can be understood using a far-from-threshold approach and simple scaling arguments. Further, we find that the various shapes can be organized in a phase diagram using the twist, the tension, and the geometry of the ribbon as control parameters. Finally, I will discuss the spontaneous formation of topological defects with negatively-signed Gaussian charge at large twist and small but finite stretch.

Transport gap engineering by contact geometry in graphene nanoribbons: Experimental and theoretical studies on artificial materials

NASA Astrophysics Data System (ADS)

Stegmann, Thomas; Franco-Villafañe, John A.; Kuhl, Ulrich; Mortessagne, Fabrice; Seligman, Thomas H.

2017-01-01

Electron transport in small graphene nanoribbons is studied by microwave emulation experiments and tight-binding calculations. In particular, it is investigated under which conditions a transport gap can be observed. Our experiments provide evidence that armchair ribbons of width 3 m +2 with integer m are metallic and otherwise semiconducting, whereas zigzag ribbons are metallic independent of their width. The contact geometry, defining to which atoms at the ribbon edges the source and drain leads are attached, has strong effects on the transport. If leads are attached only to the inner atoms of zigzag edges, broad transport gaps can be observed in all armchair ribbons as well as in rhomboid-shaped zigzag ribbons. All experimental results agree qualitatively with tight-binding calculations using the nonequilibrium Green's function method.

String stabilized ribbon growth a method for seeding same

DOEpatents

Sachs, Emanuel M.

1987-08-25

This invention is a method of initiating or seeding the growth of a crystalline or polycrystalline ribbon by the String Stabilized Ribbon Growth Method. The method for seeding the crystal growth comprises contacting a melt surface with a seed and two strings used in edge stabilization. The wetted strings attach to the wetted seed as a result of the freezing of the liquid melt. Upon drawing the seed, which is attached to the strings, away from the melt surface a melt liquid meniscus, a seed junction, and a growth interface forms. Further pulling of the attached seed causes a crystal ribbon to grow at the growth interface. The boundaries of the growing ribbon are: at the top the seed junction, at the bottom the freezing boundary of the melt liquid meniscus, and at the edges frozen-in strings.

Laser-zone Growth in a Ribbon-to-ribbon (RTR) Process Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Solar Array Project

NASA Technical Reports Server (NTRS)

Baghdadi, A.; Gurtler, R. W.; Legge, R.; Sopori, B.; Rice, M. J.; Ellis, R. J.

1979-01-01

A technique for growing limited-length ribbons continually was demonstrated. This Rigid Edge technique can be used to recrystallize about 95% of the polyribbon feedstock. A major advantage of this method is that only a single, constant length silicon ribbon is handled throughout the entire process sequence; this may be accomplished using cassettes similar to those presently in use for processing Czochralski waters. Thus a transition from Cz to ribbon technology can be smoothly affected. The maximum size being considered, 3 inches x 24 inches, is half a square foot, and will generate 6 watts for 12% efficiency at 1 sun. Silicon dioxide has been demonstrated as an effective, practical diffusion barrier for use during the polyribbon formation.

Surface effects on the magnetic properties of nearly zero-magnetostriction amorphous ribbons subjected to nonuniform stresses

NASA Astrophysics Data System (ADS)

Buttino, G.; Cecchetti, A.; Poppi, M.; Zini, G.

1992-11-01

A remarkable initial permeability associated with a decrease of the disaccomodation has been obtained in nearly zero-magnetostrictive Metglas by applying weak elastic bending stresses. The stresses are produced by winding the ribbons to form toroids of different radii. The above effects depend on the way of winding the ribbon i.e whether the shiny surface of the ribbon is at the inside or the outside of the core. The discussion emphasizes a different role of the two surface layers of the ribbon on the behaviour of the samples. The results are explained on the basis of the hypothesis advanced by Hernando et al. who assume the λ s ≃ 0 condition in the above materials as due to the coexistence of different magnetostrictive phases on a macroscopic scale.

Effect of Mechanical Stresses in Rapidly Heated Fe73Cu1Nb3Si16B7 Ribbon Arising During the Ring Core Formation on Their Magnetic Properties

NASA Astrophysics Data System (ADS)

Nosenko, Anton; Mika, Taras; Semyrga, Olexandr; Nosenko, Viktor

2017-04-01

The influence of winding-induced mechanical stresses on the magnetic anisotropy and core loss in toroidal cores made of Fe73Cu1Nb3Si16B7 ribbon is studied. The ribbon for the cores was rapidly pre-heated under tensile stress up to 120 MPa. It was found that magnetic characteristics of the material (magnetic anisotropy energy and the core loss) can be controlled by varying the tensile stress during the preliminary rapid heating of the ribbon. It was shown that with reducing core diameter, the magnetic anisotropy energy and core loss significantly increase. However, relatively high winding-induced core loss in small cores can be significantly reduced by increasing tensile stresses applied to the ribbon during pre-heating.

Effect of Mechanical Stresses in Rapidly Heated Fe73Cu1Nb3Si16B7 Ribbon Arising During the Ring Core Formation on Their Magnetic Properties.

PubMed

Nosenko, Anton; Mika, Taras; Semyrga, Olexandr; Nosenko, Viktor

2017-12-01

The influence of winding-induced mechanical stresses on the magnetic anisotropy and core loss in toroidal cores made of Fe 73 Cu 1 Nb 3 Si 16 B 7 ribbon is studied. The ribbon for the cores was rapidly pre-heated under tensile stress up to 120 MPa. It was found that magnetic characteristics of the material (magnetic anisotropy energy and the core loss) can be controlled by varying the tensile stress during the preliminary rapid heating of the ribbon. It was shown that with reducing core diameter, the magnetic anisotropy energy and core loss significantly increase. However, relatively high winding-induced core loss in small cores can be significantly reduced by increasing tensile stresses applied to the ribbon during pre-heating.

Transmission line design for a power distribution system at 20 kHz for aircraft

NASA Technical Reports Server (NTRS)

Zelby, L. W.; Mathes, J. B.; Shawver, J. W.

1986-01-01

A low inductance, low characteristic impedance transmission line was designed for a 20 kHz power distribution system. Several different conductor configurations were considered: strip lines, interdigitated metal ribbons, and standard insulated wires in multiwire configurations (circular and rectangular cylindrical arrangements). The final design was a rectangular arrangement of multiple wires of the same gauge with alternating polarities from wire to wire. This offered the lowest inductance per unit length (on the order of several nanohenries/meter) and the lowest characteristic impedance (on the order of one Ohm). Standard multipin connectors with gold-plated elements were recommended with this transmission line, the junction boxes to be internally connected with flat metal ribbons for low inductance, and the line to be constructed in sections of suitable length. Computer programs for the calculation of inductance of multiwire lines and of capacitances of strip lines were developed.

Onset of a Large Ejective Solar Eruption from a Typical Coronal-jet-base Field Configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, Navin Chandra; Magara, Tetsuya; Moon, Yong-Jae

Utilizing multiwavelength observations and magnetic field data from the Solar Dynamics Observatory ( SDO )/Atmospheric Imaging Assembly (AIA), SDO /Helioseismic and Magnetic Imager (HMI), the Geostationary Operational Environmental Satellite ( GOES ), and RHESSI , we investigate a large-scale ejective solar eruption of 2014 December 18 from active region NOAA 12241. This event produced a distinctive “three-ribbon” flare, having two parallel ribbons corresponding to the ribbons of a standard two-ribbon flare, and a larger-scale third quasi-circular ribbon offset from the other two. There are two components to this eruptive event. First, a flux rope forms above a strong-field polarity inversionmore » line and erupts and grows as the parallel ribbons turn on, grow, and spread apart from that polarity inversion line; this evolution is consistent with the mechanism of tether-cutting reconnection for eruptions. Second, the eruption of the arcade that has the erupting flux rope in its core undergoes magnetic reconnection at the null point of a fan dome that envelops the erupting arcade, resulting in formation of the quasi-circular ribbon; this is consistent with the breakout reconnection mechanism for eruptions. We find that the parallel ribbons begin well before (∼12 minutes) the onset of the circular ribbon, indicating that tether-cutting reconnection (or a non-ideal MHD instability) initiated this event, rather than breakout reconnection. The overall setup for this large-scale eruption (diameter of the circular ribbon ∼10{sup 5} km) is analogous to that of coronal jets (base size ∼10{sup 4} km), many of which, according to recent findings, result from eruptions of small-scale “minifilaments.” Thus these findings confirm that eruptions of sheared-core magnetic arcades seated in fan–spine null-point magnetic topology happen on a wide range of size scales on the Sun.« less

Large area silicon sheet by EFG. [Edge-defined Film-fed Growth

NASA Technical Reports Server (NTRS)

Rao, C. V. H.; Surek, T.; Mackintosh, B.; Ravi, K. V.; Wald, F. V.

1978-01-01

The edge-defined, film-fed growth (EFG) technique has been employed to grow silicon ribbons for photovoltaic applications. Considerable progress has been made in recent years in developing the technique to the point that long lengths of silicon ribbon can be routinely grown. In order to attain the full low-cost potential of the EFG technique, several further developments such as the growth of thinner and wider ribbons, increase in ribbon growth rate, and improvements in material quality are needed. The technological problems to be solved and the approaches employed to achieve these goals are discussed.

Electron Transport in Multi-Terminal Graphene Nanodevice with Inclined Cross Structures

NASA Astrophysics Data System (ADS)

Ye, En-Jia; Shi, Yi-Jian; Zhao, Xuean

2014-12-01

The DC and AC transport properties are investigated in multi-terminal graphene nanoribbon (GNR) devices. The devices are composed of three or four graphene ribbons connected with different angles. It is found that DC and AC conductances depend on the structural configurations and ribbon properties. In the vicinity of Dirac point, the intersection of graphene ribbons forms band mixing and results in resonant or anti-resonant states. The edge and width, as well as, the angles of the graphene ribbons influence the DC and AC transport properties drastically. These properties can be used to build future graphene-based nanoelectronics.

THE ENERGY-DEPENDENT POSITION OF THE IBEX RIBBON DUE TO THE SOLAR WIND STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaczyna, Paweł; Bzowski, Maciej; Sokół, Justyna M., E-mail: pswaczyna@cbk.waw.pl

2016-08-10

Observations of energetic neutral atoms (ENAs) allow for remote studies of the condition of plasma in the heliosphere and the neighboring local interstellar medium. The first results from the Interstellar Boundary Explorer ( IBEX ) revealed an arc-like enhancement of the ENA intensity in the sky, known as the ribbon. The ribbon was not expected from the heliospheric models prior to the launch of IBEX . One proposed explanation for the ribbon is the mechanism of secondary ENA emission. The ribbon reveals energy-dependent structure in the relative intensity along its circumference and in its position. That is, the geometric centermore » of the ribbon varies systematically by about 10° in the energy range 0.7–4.3 keV. Here, we show by analytical modeling that this effect is a consequence of the helio-latitudinal structure of the solar wind reflected in the secondary ENAs. Along with a recently measured distance to the ribbon’s source just beyond the heliopause, our findings support the connection of the ribbon with the local interstellar magnetic field by the mechanism of secondary ENA emission. However, the magnitude of the center shift in the highest IBEX energy channel is much larger in the observations than expected from the modeling. This may be due to another, not currently recognized, process of ENA generation.« less

Insights into the Structure and Function of Ciliary and Flagellar Doublet Microtubules

PubMed Central

Linck, Richard; Fu, Xiaofeng; Lin, Jianfeng; Ouch, Christna; Schefter, Alexandra; Steffen, Walter; Warren, Peter; Nicastro, Daniela

2014-01-01

Cilia and flagella are conserved, motile, and sensory cell organelles involved in signal transduction and human disease. Their scaffold consists of a 9-fold array of remarkably stable doublet microtubules (DMTs), along which motor proteins transmit force for ciliary motility and intraflagellar transport. DMTs possess Ribbons of three to four hyper-stable protofilaments whose location, organization, and specialized functions have been elusive. We performed a comprehensive analysis of the distribution and structural arrangements of Ribbon proteins from sea urchin sperm flagella, using quantitative immunobiochemistry, proteomics, immuno-cryo-electron microscopy, and tomography. Isolated Ribbons contain acetylated α-tubulin, β-tubulin, conserved protein Rib45, >95% of the axonemal tektins, and >95% of the calcium-binding proteins, Rib74 and Rib85.5, whose human homologues are related to the cause of juvenile myoclonic epilepsy. DMTs contain only one type of Ribbon, corresponding to protofilaments A11-12-13-1 of the A-tubule. Rib74 and Rib85.5 are associated with the Ribbon in the lumen of the A-tubule. Ribbons contain a single ∼5-nm wide filament, composed of equimolar tektins A, B, and C, which interact with the nexin-dynein regulatory complex. A summary of findings is presented, and the functions of Ribbon proteins are discussed in terms of the assembly and stability of DMTs, ciliary motility, and other microtubule systems. PMID:24794867

Flow Caster Produces Custom Alloy Magnetic Ribbon

NASA Image and Video Library

2016-12-21

NASA Glenn’s large-scale, 5 kg planar flow caster cools a vat of molten metallic alloy, producing a magnetic ribbon that spouts into a collection bin. The caster has the ability to produce a magnetized ribbon that measures up to one mile long and 50 mm wide to support NASA’s hybrid electric aircraft propulsion and power management work.

Ultrasonic Measurement Of Silicon-Growth Interface

NASA Technical Reports Server (NTRS)

Heyser, Richard C.

1988-01-01

Position of interface between silicon melt and growing ribbon of silicon measured with aid of reflected ultrasound, according to proposal. Reflections reveal characteristics of ribbon and melt. Ultrasound pulses travel through rods to silicon ribbon growing by dendritic-web process. Rods return reflections of pulses to sonic transducers. Isolate transducers thermally, but not acoustically, from hot silicon melt.

Thin-Ribbon Tapered Couplers For Dielectric Waveguides

NASA Technical Reports Server (NTRS)

Otoshi, Tom Y.; Shimabukuro, Fred I.; Yeh, Cavour

1996-01-01

Thin-ribbon tapered couplers proposed for launching electro-magnetic waves into dielectric waveguides, which include optical fibers. Intended for use with ribbon dielectric waveguides designed for operation at millimeter or submillimeter wavelengths, made of high-relative-permittivity, low-loss materials and thicknesses comparable to or less than free-space design wavelengths. Coupling efficiencies exceeds those of older tapered couplers.

77 FR 30592 - Agency Information Collection (Yellow Ribbon Agreement Under Title 38 U.S.C. Chapter 33) Activity...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-23

... McLamb, Program Analyst, Enterprise Records Service. [FR Doc. 2012-12384 Filed 5-22-12; 8:45 am] BILLING... Office of Management and Budget (OMB) for review and comment. The PRA submission describes the nature of... the Submission Contact: Denise McLamb, Enterprise Records Service (005R1B), Department of Veterans...

Simulations of a dynamic solar cycle and its effects on the interstellar boundary explorer ribbon and globally distributed energetic neutral atom flux

DOE PAGES

Zirnstein, E. J.; Heerikhuisen, J.; Pogorelov, N. V.; ...

2015-04-23

Observations by the Interstellar Boundary Explorer (IBEX) have vastly improved our understanding of the interaction between the solar wind (SW) and local interstellar medium through direct measurements of energetic neutral atoms (ENAs); this informs us about the heliospheric conditions that produced them. An enhanced feature of flux in the sky, the so-called IBEX ribbon, was not predicted by any global models before the first IBEX observations. A dominating theory of the origin of the ribbon, although still under debate, is a secondary charge-exchange process involving secondary ENAs originating from outside the heliopause. According to this mechanism, the evolution of themore » solar cycle should be visible in the ribbon flux. Therefore, in this paper we simulate a fully time-dependent ribbon flux, as well as globally distributed flux from the inner heliosheath (IHS), using time-dependent SW parameters from Sokol et al. as boundary conditions for our time-dependent heliosphere simulation. After post-processing the results to compute H ENA fluxes, these results show that the secondary ENA ribbon indeed should be time dependent, evolving with a period of approximately 11 yr, with differences depending on the energy and direction. Our results for the IHS flux show little periodic change with the 11 yr solar cycle, but rather with short-term fluctuations in the background plasma. And, while the secondary ENA mechanism appears to emulate several key characteristics of the observed IBEX ribbon, it appears that our simulation does not yet include all of the relevant physics that produces the observed ribbon.« less

SIMULATIONS OF A DYNAMIC SOLAR CYCLE AND ITS EFFECTS ON THE INTERSTELLAR BOUNDARY EXPLORER RIBBON AND GLOBALLY DISTRIBUTED ENERGETIC NEUTRAL ATOM FLUX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zirnstein, E. J.; Heerikhuisen, J.; Pogorelov, N. V.

2015-05-01

Since 2009, observations by the Interstellar Boundary Explorer (IBEX) have vastly improved our understanding of the interaction between the solar wind (SW) and local interstellar medium through direct measurements of energetic neutral atoms (ENAs), which inform us about the heliospheric conditions that produced them. An enhanced feature of flux in the sky, the so-called IBEX ribbon, was not predicted by any global models before the first IBEX observations. A dominating theory of the origin of the ribbon, although still under debate, is a secondary charge-exchange process involving secondary ENAs originating from outside the heliopause. According to this mechanism, the evolutionmore » of the solar cycle should be visible in the ribbon flux. Therefore, in this paper we simulate a fully time-dependent ribbon flux, as well as globally distributed flux from the inner heliosheath (IHS), using time-dependent SW parameters from Sokół et al. as boundary conditions for our time-dependent heliosphere simulation. After post-processing the results to compute H ENA fluxes, our results show that the secondary ENA ribbon indeed should be time dependent, evolving with a period of approximately 11 yr, with differences depending on the energy and direction. Our results for the IHS flux show little periodic change with the 11 yr solar cycle, but rather with short-term fluctuations in the background plasma. While the secondary ENA mechanism appears to emulate several key characteristics of the observed IBEX ribbon, it appears that our simulation does not yet include all of the relevant physics that produces the observed ribbon.« less

THE 2-3 kHz HELIOSPHERIC RADIATION, THE IBEX RIBBON, AND THE THREE-DIMENSIONAL SHAPE OF THE HELIOPAUSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuselier, Stephen A.; Cairns, Iver H.

2013-07-10

Recent Interstellar Boundary Explorer (IBEX) observations indicate that the total dynamic pressure in the interstellar medium is closely partitioned between the plasma and the magnetic field, with an Alfven Mach number M{sub A} {approx} 1 and a sonic Mach number {approx}2. Observations of the IBEX Ribbon provide a unique determination of the orientation of the undraped interstellar magnetic field along the heliopause. There is also a striking correspondence between the Ribbon location and the source locations of 2-3 kHz radiation determined from Voyager observations: the radiation sources north of the ecliptic form a line parallel to but offset by aboutmore » 30 Degree-Sign from the Ribbon. A general Rankine-Hugoniot analysis is used to argue that the heliopause should not be symmetric about the velocity vector V{sub ISM} of the interstellar medium relative to the Sun (the nominal nose direction). Furthermore, the closest point on the heliopause to the Sun should be on the Ribbon for M{sub A} = 0 and at least 9 Degree-Sign from the nominal nose direction toward the Ribbon for M{sub A} = 1. These new results are combined into a conceptual model of the heliopause that includes (1) a plasma depletion layer formed as the interstellar magnetic field drapes against the heliopause, (2) a minimum inner heliosheath thickness and closest point between the Sun and heliopause along (or close to) the Ribbon rather than in the nominal nose direction (along V{sub ISM}), and (3) inference of an asymmetric heliopause shape from the angular offset of the radio sources and Ribbon and from the Rankine-Hugoniot analysis.« less

Customized ATP towpreg. [Automated Tow Placement

NASA Technical Reports Server (NTRS)

Sandusky, Donald A.; Marchello, Joseph M.; Baucom, Robert M.; Johnston, Norman J.

1992-01-01

Automated tow placement (ATP) utilizes robotic technology to lay down adjacent polymer-matrix-impregnated carbon fiber tows on a tool surface. Consolidation and cure during ATP requires that void elimination and polymer matrix adhesion be accomplished in the short period of heating and pressure rolling that follows towpreg ribbon placement from the robot head to the tool. This study examined the key towpreg ribbon properties and dimensions which play a significant role in ATP. Analysis of the heat transfer process window indicates that adequate heating can be achieved at lay down rates as high as 1 m/sec. While heat transfer did not appear to be the limiting factor, resin flow and fiber movement into tow lap gaps could be. Accordingly, consideration was given to towpreg ribbon having uniform yet non-rectangular cross sections. Dimensional integrity of the towpreg ribbon combined with customized ribbon architecture offer great promise for processing advances in ATP of high performance composites.

High temperature (900-1300 C) mechanical behaviour of dendritic web grown silicon ribbons - Strain rate and temperature dependence of the yield stress

NASA Technical Reports Server (NTRS)

Mathews, V. K.; Gross, T. S.

1987-01-01

The mechanical behavior of dendritic web Si ribbons close the melting point was studied experimentally. The goal of the study was to generate data for modeling the generation of stresses and dislocation structures during growth of dendritic web Si ribbons, thereby permitting modifications to the production process, i.e., the temperature profile, to lower production costs for the photovoltaic ribbons. A laser was used to cut specimens in the direction of growth of sample ribbons, which were then subjected to tensile tests at temperatures up to 1300 C in an Ar atmosphere. The tensile strengths of the samples increased when the temperature rose above 1200 C, a phenomena which was attributed to the diffusion of oxygen atoms to the quasi-dislocation sites. The migration to the potential dislocations sites effectively locked the dislocations.

Self-Assembly of Helical Ribbons

NASA Astrophysics Data System (ADS)

Zastavker, Yevgeniya V.; Asherie, Neer; Lomakin, Aleksey; Pande, Jayanti; Donovan, Joanne M.; Schnur, Joel M.; Benedek, George B.

1999-07-01

The self-assembly of helical ribbons is examined in a variety of multicomponent enantiomerically pure systems that contain a bile salt or a nonionic detergent, a phosphatidylcholine or a fatty acid, and a steroid analog of cholesterol. In almost all systems, two different pitch types of helical ribbons are observed: high pitch, with a pitch angle of 54± 2 degrees, and low pitch, with a pitch angle of 11± 2 degrees. Although the majority of these helices are right-handed, a small proportion of left-handed helices is observed. Additionally, a third type of helical ribbon, with a pitch angle in the range 30-47 degrees, is occasionally found. These experimental findings suggest that the helical ribbons are crystalline rather than liquid crystal in nature and also suggest that molecular chirality may not be the determining factor in helix formation. The large yields of helices produced will permit a systematic investigation of their individual kinetic evolution and their elastic moduli.

Metal — Insulator Transition-like in Nano-Crystallized Ni-Fe-Zr Metallic Glasses

NASA Astrophysics Data System (ADS)

Hamed, F.; Obaidat, I. M.; Benkraouda, M.

2007-08-01

Ni-Fe-Zr based Metallic glassy ribbons were prepared by melt spinning technique. The compositional and structural integrity of the melt spun ribbons were verified by means of X-ray diffraction, SEM, EDX and DSC. 5 to 7 cm long ribbons of Ni-Fe-Zr based metallic glasses with different compositions were sealed inside quartz ampoules under vacuum. The sealed metallic glassy ribbons were nano-crystallized at 973 K for varying periods of time. The temperature dependence of the electrical resistivity of the nano-crystallized samples had been investigated over the temperature range 25-280 K. The crystallized ribbons at 973 K for periods for less than 4 hours displayed insulating electrical behavior like at low temperatures, while those annealed for more than 4 hours showed metallic behavior like. Nonlinear I-V characteristics were also observed at low temperatures for samples annealed for less than four hours.

Effect of Heat Treatment on Microstructure and Magnetostrictive Property of Melt-Spun Fe85Ga15 Ribbons

NASA Astrophysics Data System (ADS)

Liu, Hao; Wang, Haiou; Cao, Mengxiong; Tan, Weishi; Shi, Yangguang; Chen, Yu; Huang, Yuying

2013-09-01

In order to study the microstructure of Fe-Ga alloy, Fe85Ga15 ribbons prepared with different wheel velocity were studied by high resolution X-ray diffraction (HRXRD) and extend X-ray absorption fine structure (EXAFS). HRXRD patterns showed that only disordered A2 phase was observed in as-cast Fe85Ga15 alloy. A modified-DO3 phase was detected in all of the melt spun samples. The HRXRD associated with EXAFS results indicated that Ga atoms were located as second-nearest neighbor along [100] orientation. A little DO3 phase was found in ribbons annealed at 1000°C under 0.06 MPa Ar atmosphere. The result of magnetostriction measurement revealed that in the ribbon prepared with higher wheel velocity, more modified-DO3 phase will enhance the magnetostriction. DO3 phase in the annealed sample will deteriorate the magnetostrictive properties of Fe-Ga ribbons.

Magnetostructural transitions and magnetocaloric effects in Ni50Mn35In14.25B0.75 ribbons

NASA Astrophysics Data System (ADS)

Pandey, Sudip; Quetz, Abdiel; Ibarra-Gaytan, P. J.; Sánchez-Valdés, C. F.; Aryal, Anil; Dubenko, Igor; Sanchez Llamazares, Jose Luis; Stadler, Shane; Ali, Naushad

2018-05-01

The structural, thermal, and magnetic behaviors, as well as the martensitic phase transformation and related magnetocaloric response of Ni50Mn35In14.25B0.75 annealed ribbons have been investigated using room-temperature X-ray diffraction (XRD), differential scanning calorimetry (DSC), and magnetization measurements. Ni50Mn35In14.25B0.75 annealed ribbons show a sharper change in magnetization at the martensitic transition, resulting in larger magnetic entropy changes in comparison to bulk Ni50Mn35In14.25B0.75. A drastic shift in the martensitic transformation temperature (TM) of 70 K to higher temperature was observed for the annealed ribbons relative to that of the bulk (TM = 240 K). The results obtained for magnetic, thermal, structural, and magnetocaloric properties of annealed ribbons have been compared to those of the corresponding bulk alloys.

Powder-Coated Towpreg: Avenues to Near Net Shape Fabrication of High Performance Composites

NASA Technical Reports Server (NTRS)

Johnston, N. J.; Cano, R. J.; Marchello, J. M.; Sandusky, D. A.

1995-01-01

Near net shape parts were fabricated from powder-coated preforms. Key issues including powder loss during weaving and tow/tow friction during braiding were addressed, respectively, by fusing the powder to the fiber prior to weaving and applying a water-based gel to the towpreg prior to braiding. A 4:1 debulking of a complex 3-D woven powder-coated preform was achieved in a single step utilizing expansion rubber molding. Also, a process was developed for using powder-coated towpreg to fabricate consolidated ribbon having good dimensional integrity and low voids. Such ribbon will be required for in situ fabrication of structural components via heated head advanced tow placement. To implement process control and ensure high quality ribbon, the ribbonizer heat transfer and pulling force were modeled from fundamental principles. Most of the new ribbons were fabricated from dry polyarylene ether and polymide powders.

Earth Observations taken by the Expedition 23 Crew

NASA Image and Video Library

2010-05-29

ISS023-E-058455 (29 May 2010) --- Aurora Australis is featured in this image photographed by an Expedition 23 crew member on the International Space Station. Among the views of Earth afforded crew members aboard the ISS, surely one of the most spectacular is of the aurora. These ever-shifting displays of colored ribbons, curtains, rays, and spots are most visible near the North (Aurora Borealis) and South (Aurora Australis) Poles as charged particles streaming from the sun (the solar wind) interact with Earth’s magnetic field, resulting in collisions with atoms of oxygen and nitrogen in the upper atmosphere. The atoms are excited by these collisions, and typically emit photons as a means of returning to their original energy state. The photons form the aurora that we see. The most commonly observed color of aurora is green, caused by photons (light) emitted by excited oxygen atoms at wavelengths centered at 0.558 micrometers, or millionths of a meter. Visible light is reflected from healthy (green) plant leaves at approximately the same wavelength. Red auroras are generated by light emitted at a longer wavelength (0.630 micrometers), and other colors such as blue and purple are also sometimes observed. While auroras are generally only visible close to the poles, severe magnetic storms impacting Earth’s magnetic field can shift them towards the equator. This striking aurora image was taken during a geomagnetic storm that was most likely caused by a coronal mass ejection from the sun on May 24, 2010. The ISS was located over the Southern Indian Ocean at an altitude of 350 kilometers, with the observer most likely looking towards Antarctica (not visible) and the South Pole. The aurora has a sinuous ribbon shape that separates into discrete spots near the lower right corner of the image. While the dominant coloration of the aurora is green, there are faint suggestions of red photon emission as well (light fuscia tones at center left). Dense cloud cover is dimly visible below the aurora. The curvature of Earth’s horizon, or limb, is clearly visible as is the faint blue line of the upper atmosphere directly above at top center. Several stars appear as bright pinpoints against the blackness of space at top right.

The discovery of 9/8-ribbons, β/γ-peptides with curved shapes governed by a combined configuration-conformation code.

PubMed

Grison, Claire M; Robin, Sylvie; Aitken, David J

2015-11-21

The de novo design of a β/γ-peptidic foldamer motif has led to the discovery of an unprecedented 9/8-ribbon featuring an uninterrupted alternating C9/C8 hydrogen-bonding network. The ribbons adopt partially curved topologies determined synchronistically by the β-residue configuration and the γ-residue conformation sets.

Polymer film composite transducer

DOEpatents

Owen, Thomas E.

2005-09-20

A composite piezoelectric transducer, whose piezoeletric element is a "ribbon wound" film of piezolectric material. As the film is excited, it expands and contracts, which results in expansion and contraction of the diameter of the entire ribbon winding. This is accompanied by expansion and contraction of the thickness of the ribbon winding, such that the sound radiating plate may be placed on the side of the winding.

33 CFR 334.480 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Broad River; U.S. Marine Corps Recruit Depot, Parris Island, South Carolina; danger zones. 334.480... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek, and Broad River... danger zone on Archers Creek (between the Broad River and Beaufort River), Ribbon Creek, and the Broad...

33 CFR 334.480 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Broad River; U.S. Marine Corps Recruit Depot, Parris Island, South Carolina; danger zones. 334.480... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek, and Broad River... danger zone on Archers Creek (between the Broad River and Beaufort River), Ribbon Creek, and the Broad...

33 CFR 334.480 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Broad River; U.S. Marine Corps Recruit Depot, Parris Island, South Carolina; danger zones. 334.480... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek, and Broad River... danger zone on Archers Creek (between the Broad River and Beaufort River), Ribbon Creek, and the Broad...

Synaptic ribbon. Conveyor belt or safety belt?

PubMed

Parsons, T D; Sterling, P

2003-02-06

The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

Utilization of multiwalled boron nitride nanotubes for the reinforcement of lightweight aluminum ribbons

PubMed Central

2013-01-01

Multiwalled boron nitride nanotubes (BNNTs) have very attractive mechanical and thermal properties, e.g., elasticity, tensile strength, and high resistance to oxidation, and may be considered as ideal reinforcing agents in lightweight metal matrix composites. Herein, for the first time, Al-BNNT ribbons with various BNNT contents (up to 3 wt.%) were fabricated via melt spinning in an argon atmosphere. BNNTs were randomly dispersed within a microcrystalline Al matrix under ribbon casting and led to more than doubling of room-temperature ultimate tensile strength of the composites compared to pure Al ribbons produced at the similar conditions. PMID:23279813

Improving feeding powder distribution to the compaction zone in the roller compaction.

PubMed

Yu, Mingzhe; Omar, Chalak; Schmidt, Alexander; Litster, James D; Salman, Agba D

2018-07-01

In the roller compaction process, powder flow properties have a significant influence on the uniformity of the ribbon properties. The objective of this work was to improve the powder flow in the feeding zone by developing novel feeding guiders which are located in the feeding zone close to the rollers in the roller compactor (side sealing system). Three novel feeding guiders were designed by 3D printing and used in the roller compactor, aiming to control the amount of powder passing across the roller width. The new feeding guiders were used to guide more powder to the sides between the rollers and less powder to the centre comparing to the original feeding elements. Temperature profile and porosity across the ribbon width indicated the uniformity of the ribbon properties. Using the novel feeding guiders resulted in producing ribbons with uniform temperature profile and porosity distribution across the ribbon width. The design of the feeding guiders contributed to improving the tensile strength of the ribbons produced from the compaction stage as well as reducing the fines produced from the crushing stage. Copyright © 2018 Elsevier B.V. All rights reserved.

Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

DOE PAGES

Jayaraman, T. V.; Meka, V. M.; Jiang, X.; ...

2018-01-09

Here we investigated the ambient temperature structural properties (thickness, width, microstructure, and lattice parameter), and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties—saturation magnetization (M S) and intrinsic coercivity (H CI)—of rapidly-solidified (melt-spun) Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbonsmore » ranged between ~15 and 60 μm and 500–800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). The wheel surface speed showed an insignificant effect on M S while increased silicon content resulted in a decreasing trend in M S. Elevated temperature evaluation of the magnetization (M-T curves at ~7.96 kA/m) in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from that of the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The M S for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 to 900 K). While H CI increased with the increase in temperature for all the wheel surface speed and composition combination, its nature of increase is distinct for Fe-8 wt.% Si alloy ribbons compared to Fe-3 & 5 wt.% Si alloys ribbons. Finally, it appears that rapidly-solidified Fe-3 wt.% Si and Fe-5 wt.% Si alloys ribbons are primarily comprised of the α phase (disordered phase) while the Fe-8 wt.% Si alloy ribbons are comprised primarily of disordered phase along with minor constituents of an ordered phase.« less

Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayaraman, T. V.; Meka, V. M.; Jiang, X.

Here we investigated the ambient temperature structural properties (thickness, width, microstructure, and lattice parameter), and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties—saturation magnetization (M S) and intrinsic coercivity (H CI)—of rapidly-solidified (melt-spun) Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbonsmore » ranged between ~15 and 60 μm and 500–800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). The wheel surface speed showed an insignificant effect on M S while increased silicon content resulted in a decreasing trend in M S. Elevated temperature evaluation of the magnetization (M-T curves at ~7.96 kA/m) in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from that of the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The M S for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 to 900 K). While H CI increased with the increase in temperature for all the wheel surface speed and composition combination, its nature of increase is distinct for Fe-8 wt.% Si alloy ribbons compared to Fe-3 & 5 wt.% Si alloys ribbons. Finally, it appears that rapidly-solidified Fe-3 wt.% Si and Fe-5 wt.% Si alloys ribbons are primarily comprised of the α phase (disordered phase) while the Fe-8 wt.% Si alloy ribbons are comprised primarily of disordered phase along with minor constituents of an ordered phase.« less

KENNEDY SPACE CENTER, FLA. - Daniel LeBlanc, chief operating officer of Delaware North Companies Parks and Resorts at KSC, makes the opening remarks to hundreds of guests and media representatives attending a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

NASA Image and Video Library

2003-06-20

KENNEDY SPACE CENTER, FLA. - Daniel LeBlanc, chief operating officer of Delaware North Companies Parks and Resorts at KSC, makes the opening remarks to hundreds of guests and media representatives attending a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

KENNEDY SPACE CENTER, FLA. - Center Director and former astronaut Roy D. Bridges, Jr., (holding scissors) cuts the ribbon at a ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. Invited guests and dignitaries look on, such as former astronauts Edgar D. Mitchell on Bridges' left and James Lovell on his right. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

NASA Image and Video Library

2003-06-20

KENNEDY SPACE CENTER, FLA. - Center Director and former astronaut Roy D. Bridges, Jr., (holding scissors) cuts the ribbon at a ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. Invited guests and dignitaries look on, such as former astronauts Edgar D. Mitchell on Bridges' left and James Lovell on his right. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

33 CFR 334.480 - Archers Creek, Ribbon Creek and Broad River, S.C.; U.S. Marine Corps Recruit Depot rifle and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Broad River, S.C.; U.S. Marine Corps Recruit Depot rifle and pistol ranges, Parris Island. 334.480... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek and Broad River... navigation: (1) At the rifle range. Archers Creek between Broad River and Beaufort River and Ribbon Creek...

33 CFR 334.480 - Archers Creek, Ribbon Creek and Broad River, S.C.; U.S. Marine Corps Recruit Depot rifle and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Broad River, S.C.; U.S. Marine Corps Recruit Depot rifle and pistol ranges, Parris Island. 334.480... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek and Broad River... navigation: (1) At the rifle range. Archers Creek between Broad River and Beaufort River and Ribbon Creek...

Sensor assembly

DOEpatents

Bennett, Thomas E.; Nelson, Drew V.

2004-04-13

A ribbon-like sensor assembly is described wherein a length of an optical fiber embedded within a similar lengths of a prepreg tow. The fiber is ""sandwiched"" by two layers of the prepreg tow which are merged to form a single consolidated ribbon. The consolidated ribbon achieving a generally uniform distribution of composite filaments near the embedded fiber such that excess resin does not ""pool"" around the periphery of the embedded fiber.

Ireland

NASA Image and Video Library

2017-12-08

On August 7, 2003, the NASA Aqua MODIS instrument acquired this image of Ireland on the first day this summer that most of the island hasn´t been completely obscured by cloud cover. Called the Emerald Isle for a good reason, Ireland is draped in vibrant shades of green amidst the blue Atlantic Ocean and Celtic (south) and Irish (east) Seas. Faint ribbons of blue-green phytoplankton drift in the waters of the Celtic Sea, just south of Dublin. Dublin itself appears as a large grayish-brown spot on the Republic of Ireland´s northeastern coast. This large capital city (population 1.12 million) sits on the River Liffey, effectively splitting the city in half. Northern Ireland´s capital city, Belfast, also sits on a river: the River Lagan. This city, though its population is only a fifth of the size of Dublin´s, is also clearly visible in the image as a grayish-brown spot on the coast of the Irish Sea. Sensor Aqua/MODIS Credit Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC For more information go to: visibleearth.nasa.gov/view_rec.php?id=5744 NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

1401315

NASA Image and Video Library

2014-09-12

RIBBON CUTTING AT VERTICAL ASSEMBLY CENTER, MICHOUD ASSEMBLY FACILITY, SEPTEMBER 12, 2014, (L TO R): CLAY KIEFABER, CEO OF ESAB (COMPANY THAT BUILT WELDING TOOL)…PATRICK SCHEUERMANN…ROBERT LIGHTFOOT…TODD MAY…MISSISSIPPI CONGRESSMAN STEVEN PALAZZO…CHARLIE BOLDEN…LOUISIANA SENATOR DAVID VITTER…VIRGINIA BARNES, VICE-PRESIDENT AND PROGRAM MANAGER FOR SLS - BOEING… MITCH LANDRIEU, MAYOR OF NEW ORLEANS… JOHN ELBON, VICE PRESIDENT/GENERAL MANAGER, SPACE EXPLORATIONS – BOEING…PATRICK FORRESTER, ASTRONAUT…ROY MALONE.

Effects of surface crystallization and oxidation in nanocrystalline FeNbCuSiB(P) ribbons

NASA Astrophysics Data System (ADS)

Butvinová, B.; Butvin, P.; Brzózka, K.; Kuzminski, M.; Maťko, I.; Švec, P., Sr.; Chromčíková, M.

2017-02-01

Si-poor Fe74Nb3Cu1Si8B14-xPx, (x=0, 3) nanocrystalline ribbon-form alloys often form surfaces, which exert in-plane force on underlying ribbon interior when nanocrystallized in even modest presence of oxygen. Mostly unwanted hard-ribbon-axis magnetic anisotropy is standard result. Essential sources of the surface-caused stress have been sought and influence of P instead of B substitution on this effect was studied too. Preferred surface crystallization (PSC) was found to be the major reason. However P substitution suppresses PSC and promotes Fe-oxide formation, which eases the stress, softens the surfaces and provides different annealing evolution of surface properties.

Apparatus for assembling space structure

NASA Technical Reports Server (NTRS)

Johnston, J. D.; Tuggle, R. H., Jr.; Burch, J. L.; Clark, K. H. (Inventor)

1978-01-01

An apparatus for producing a structure in outer space from rolls of prepunched ribbon or sheet material that are transported from the earth to the apparatus located in outer space is described. The apparatus spins the space structure similar to a spider spinning a web utilizing the prepunched ribbon material. The prepunched ribbon material is fed through the apparatus and is shaped into a predetermined channel-shaped configuration. Trusses are punched out of the ribbon and are bent downwardly and attached to a track which normally is a previously laid sheet of material. The size of the overall space structure may be increased by merely attaching an additional roll of sheet material to the apparatus.

Interaction of Graphene ribbon with atmospheric chemical species

DTIC Science & Technology

2017-04-14

graphene ribbons is an important process in interaction of atmospheric radical with graphene. This study examines how the size of the graphene ribbon...an important process in interaction of atmospheric  radical  with  graphene.   This  study  examines how  the  size of  the  graphene  ribbon affects  the... journals   [a1]  Journal  name:CARBON              Title: Size dependence of graphene chemistry: A computational  study  on CO desorption reaction    Date

Defects in High Speed Growth of EFG Silicon Ribbon

NASA Technical Reports Server (NTRS)

Rao, C. V. H. N.; Cretella, M. C.

1984-01-01

Silicon ribbons grown by the Edge-defined Film-fed Growth (EFG) technique exhibit a characteristic defect structure typified by twins, dislocations, grain boundaries and silicon carbide inclusions. As growth speed is increased from less than 2.5 cm per minute, the structural details change. The major difference between the ribbons grown at speeds below and above 2.5 cm per minute is in the generation of a cellular structure at the higher growth speeds, observable in the ribbon cross section. The presence of the cross sectional structure leads, in general, to a reduction in cell performance. Models to explain the formation of such a cross sectional structure are presented and discussed.

Large area silicon sheet by EFG

NASA Technical Reports Server (NTRS)

1981-01-01

The influence of parameters such as CO2 concentration, gas flow patterns, quartz in the bulk melt, melt doping level and growth speed on ribbon properties was examined for 10 cm wide ribbon. Ribbon quality is optimized for ambient CO2 in argon concentrations in the range from 1000 to 5000 ppm. Cell performance degrades at CO2 concentrations above 5000 ppm and IR interstitial oxygen levels decrease. These experiments were done primarily at a growth speed of 3.5 cm/minute. Cartridge parameters influencing the ribbon thickness were studied and thickness uniformity at 200 micrometers (8 mils) has been improved. Growth stability at the target speed of 4.0 cm/minute was improved significantly.

Thermoplastic Ribbon-Ply Bonding Model

NASA Technical Reports Server (NTRS)

Hinkley, Jeffrey A.; Marchello, Joseph M.; Messier, Bernadette C.

1996-01-01

The aim of the present work was to identify key variables in rapid weldbonding of thermoplastic tow (ribbon) and their relationship to matrix polymer properties and to ribbon microstructure. Theoretical models for viscosity, establishment of ply-ply contact, instantaneous (Velcro) bonding, molecular interdiffusion (healing), void growth suppression, and gap filling were reviewed and synthesized. Consideration of the theoretical bonding mechanisms and length scales and of the experimental weld/peel data allow the prediction of such quantities as the time and pressure required to achieve good contact between a ribbon and a flat substrate, the time dependence of bond strength, pressures needed to prevent void growth from dissolved moisture and conditions for filling gaps and smoothing overlaps.

How Do Rab Proteins Determine Golgi Structure?

PubMed Central

Liu, Shijie; Storrie, Brian

2015-01-01

Rab proteins, small GTPases, are key regulators of mammalian Golgi apparatus organization. Based on the effect of Rab activation state, Rab proteins fall into two functional classes. In Class1, inactivation induces Golgi ribbon fragmentation and/or redistribution of Golgi enzymes to the ER, while overexpression of wild type or activation has little, if any, effect on Golgi ribbon organization. In Class 2, the reverse is true. We give emphasis to Rab6, the most abundant Golgi-associated Rab protein. Rab6 depletion in HeLa cells causes an increase in Golgi cisternal number, longer, more continuous cisternae, and a pronounced accumulation of vesicles; the effect of Rab6 on Golgi ribbon organization is probably through regulation of vesicle transport. In effector studies, motor proteins and their regulators are found to be key Rab6 effectors. A related Rab, Rab41, affects Golgi ribbon organization in a contrasting manner. The balance between minus- and plus-end directed motor recruitment may well be the major Rab-dependent factor in Golgi ribbon organization. PMID:25708460

Geometry and surface controlled formation of nanoparticle helical ribbons

NASA Astrophysics Data System (ADS)

Pham, Jonathan; Lawrence, Jimmy; Lee, Dong; Grason, Gregory; Emrick, Todd; Crosby, Alfred

2013-03-01

Helical structures are interesting because of their space efficiency, mechanical tunability and everyday uses in both the synthetic and natural world. In general, the mechanisms governing helix formation are limited to bilayer material systems and chiral molecular structures. However, in a special range of dimensions where surface energy dominates (i.e. high surface to volume ratio), geometry rather than specific materials can drive helical formation of thin asymmetric ribbons. In an evaporative assembly technique called flow coating, based from the commonly observed coffee ring effect, we create nanoparticle ribbons possessing non-rectangular nanoscale cross-sections. When released into a liquid medium of water, interfacial tension between the asymmetric ribbon and water balances with the elastic cost of bending to form helices with a preferred radius of curvature and a minimum pitch. We demonstrate that this is a universal mechanism that can be used with a wide range of materials, such as quantum dots, metallic nanoparticles, or polymers. Nanoparticle helical ribbons display excellent structural integrity with spring-like characteristics and can be extended high strains.

First-principles investigation of armchair boron nitride nanoribbons for sensing PH3 gas molecules

NASA Astrophysics Data System (ADS)

Srivastava, Pankaj; Jaiswal, Neeraj K.; Sharma, Varun

2014-09-01

The present work exhibits density functional theory (DFT) based first-principles calculations to explore the sensing properties of bare armchair boron nitride nanoribbons (ABNNR) for PH3 gas molecules. Edges of the ribbon were considered as the sites of possible adsorption with two different configurations i.e. adsorption at one edge and adsorption at both edges of the ribbon. It is revealed that B atoms of the ribbons are more energetically favorable sites for the adsorption of PH3 molecules as compared with N atoms. The adsorption of PH3 affects the electronic properties of nanoribbons. One edge PH3 adsorbed ribbons are metallic whereas in both edges PH3 adsorption, the band gap is decreased than that of bare ribbon. The changes in electronic properties caused by PH3 adsorption are further supported by the current-voltage (I-V) characteristics of the considered configurations. The results show that ABNNR can serve as a potential candidate for PH3 sensing applications.

Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives.

PubMed

Haigler, C H; White, A R; Brown, R M; Cooper, K M

1982-07-01

In vivo cellulose ribbon assembly by the Gram-negative bacterium Acetobacter xylinum can be altered by incubation in carboxymethylcellulose (CMC), a negatively charged water-soluble cellulose derivative, and also by incubation in a variety of neutral, water-soluble cellulose derivatives. In the presence of all of these substituted celluloses, normal fasciation of microfibril bundles to form the typical twisting ribbon is prevented. Alteration of ribbon assembly is most extensive in the presence of CMC, which often induces synthesis of separate, intertwining bundles of microfibrils. Freeze-etch preparations of the bacterial outer membrane suggest that particles that are thought to be associated with cellulose synthesis or extrusion may be specifically organized to mediate synthesis of microfibril bundles. These data support the previous hypothesis that the cellulose ribbon of A. xylinum is formed by a hierarchical, cell-directed, self-assembly process. The relationship of these results to the regulation of cellulose microfibril size and wall extensibility in plant cell walls is discussed.

Elevated temperature strengthening of a melt spun austenitic steel by TiB2

NASA Technical Reports Server (NTRS)

Michal, G. M.; Glasgow, T. K.; Moore, T. J.

1986-01-01

Mechanical properties of an iron-based alloy containing (by wt pct) 33Ni, 2Al, 6Ti, and 2B (resulting in an alloy containing 10 vol pct TiB2) were evaluated by hardness and tensile testing. The alloy was cast as a ribbon using a dual 'free-jet' variation of Jech et al. (1984) method of chill-block melt-spinning against a copper wheel; to simulate thermal cycles the alloy ribbon would experience during compaction into shapes, various segments of the ribbon were annealed under a vacuum at temperatures ranging from 500 to 1150 C. The results show that maximum strengths at 650 and 760 C were developed in ribbons annealed at 1100 C; in these ribbons an optimal combination of grain coarsening with minimum TiB2 particle growth was observed. However, the elevated-temperature strength of the TiB2-strengthened alloy under optimal annealing conditions was poorer than that of conventional iron-based superalloys strengthened by gamma-prime precipitates.

Symmetries and band gaps in nanoribbons

NASA Astrophysics Data System (ADS)

Zhang, Zhiwei; Tian, Yiteng; Fernando, Gayanath; Kocharian, Armen

In ideal graphene-like systems, time reversal and sublattice symmetries preserve the degeneracies at the Dirac point(s). We have examined such degeneracies in the band structure as well as the transport properties in various arm-twisted (graphene-related) nanoribbons. A twist angle is defined such that at 0 degrees the ribbon is a rectangular ribbon and at 60 degrees the ribbon is cut from a honeycomb lattice. Using model Hamiltonians and first principles calculations in these nanoribbons with Z2 topology, we have monitored the band structure as a function of the twist angle θ. In twisted ribbons, it turns out that the introduction of an extra hopping term leads to a gap opening. We have also calculated the size and temperature broadening effects in similar ribbons in addition to Rashba-induced transport properties. The authors acknowledge the computing facilities provided by the Center for Functional Nanomaterials, Brookhaven National Laboratory supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No.DE-AC02- 98CH10886.

Nanoporous Ag prepared from the melt-spun Cu-Ag alloys

NASA Astrophysics Data System (ADS)

Li, Guijing; Song, Xiaoping; Sun, Zhanbo; Yang, Shengchun; Ding, Bingjun; Yang, Sen; Yang, Zhimao; Wang, Fei

2011-07-01

Nanoporous Ag ribbons with different morphology and porosity were achieved by the electrochemical corrosion of the melt-spun Cu-Ag alloys. The Cu-rich phase in the alloys was removed, resulting in the formation of the nanopores distributed across the whole ribbon. It is found that the structures, morphology and porosity of the nanoporous Ag ribbons were dependent on the microstructures of the parent alloys. The most of ligaments presented a rod-like shape due to the formation of pseudoeutectic microstructure in the melt-spun Cu 55Ag 45 and Cu 70Ag 30 alloys. For nanoporous Ag prepared from Cu 85Ag 15 alloys, the ligaments were camber-like because of the appearance of the divorced microstructures. Especially, a novel bamboo-grove-like structure could be observed at the cross-section of the nanoporous Ag ribbons. The experiment reveals that nanoporous Ag ribbons exhibited excellent enhancement of surface-enhanced Raman scattering (SERS) effect, but a slight difference existed due to the discrepancy of their morphology.

Use of Data to Develop a Code Blue Training Program

DTIC Science & Technology

2017-01-28

MDW/SGVU SUBJECT: Professional Presentation Approval 7 FEB 2016 1. Your paper, entitled Use of Data to Develop a Code Blue Training Program...3039 must be submitted for review and approval.) 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: Use of Data to Develop a Code Blue Training ...January 19, 2017 D N/A 29. COMMENTS ~ APPROVED 0 DISAPPROVED Approved training presentation with appropriate disclaimers based on training curriculum

Ribbon electron beam formation by a forevacuum plasma electron source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klimov, A. S., E-mail: klimov@main.tusur.ru; Burdovitsin, V. A.; Grishkov, A. A.

2016-01-15

Results of the numerical analysis and experimental research on ribbon electron beam generation based on hollow cathode discharge at forevacuum gas pressure are presented. Geometry of the accelerating gap has modified. It lets us focus the ribbon electron beam and to transport it on a distance of several tens of centimeters in the absence of an axial magnetic field. The results of numerical simulations are confirmed by the experiment.

Web-dendritic growth. [single crystal silicon ribbons for solar cells

NASA Technical Reports Server (NTRS)

Hilborn, R. B.; Faust, J. W., Jr.; Rhodes, C.

1977-01-01

The effects of various machine design parameters on the growth of web dendritic silicon ribbon were investigated. Ribbons were grown up to lengths of one meter, with widths increasing linearly up to one cm at the point of termination of growth. Thermal data were collected and evaluated for actual seeding and growth with variations in parameters affecting heat loss. It was found that for suitable growth, the mechanical system should be very rigid and stable, and the tolerances and specifications of the quartz crucibles must be far tighter than normal quartz tolerances. The widening rates of the ribbons were found to be a function of the temperature gradient rather than the temperature differences alone. A twin spacing in the seed of 3 microns to 2 microns was found to be unfavorable for growth; whereas spacing of 0.9 microns to 2 microns and 8 microns to 2 microns were favorable. Thermal modeling studies of the effects of furnace design parameters on the temperature distributions in melt and the growth of the dendritic web ribbon showed that the pull rate of the ribbon is strongly dependent on the temperature of the top thermal shield, the spacing between this shield and the melt, and the thickness of the growing web.

The Disturbing Effect of the Stray Magnetic Fields on Magnetoimpedance Sensors

PubMed Central

Wang, Tao; Zhou, Yong; Lei, Chong; Zhi, Shaotao; Guo, Lei; Li, Hengyu; Wu, Zhizheng; Xie, Shaorong; Luo, Jun; Pu, Huayan

2016-01-01

The disturbing effect of the stray magnetic fields of Fe-based amorphous ribbons on the giant magnetoimpedance (GMI) sensor has been investigated systematically in this paper. Two simple methods were used for examining the disturbing effect of the stray magnetic fields of ribbons on the GMI sensor. In order to study the influence of the stray magnetic fields on the GMI effect, the square-shaped amorphous ribbons were tested in front, at the back, on the left and on the top of a meander-line GMI sensor made up of soft ferromagnetic films, respectively. Experimental results show that the presence of ribbons in front or at the back of GMI sensor shifts the GMI curve to a lower external magnetic field. On the contrary, the presence of ribbons on the left or on the top of the GMI sensor shifts the GMI curve to a higher external magnetic field, which is related to the coupling effect of the external magnetic field and the stray magnetic fields. The influence of the area and angle of ribbons on GMI was also studied in this work. The GMI sensor exhibits high linearity for detection of the stray magnetic fields, which has made it feasible to construct a sensitive magnetometer for detecting the typical stray magnetic fields of general soft ferromagnetic materials. PMID:27763498

The response of macrophages to a Cu-Al-Ni shape memory alloy.

PubMed

Colić, Miodrag; Tomić, Sergej; Rudolf, Rebeka; Anzel, Ivan; Lojen, Gorazd

2010-09-01

Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but little is known about their biocompatibility. The aim of this work was to study the response of rat peritoneal macrophages (PMØ) to a Cu-Al-Ni SMA in vitro, by measuring the functional activity of mitochondria, necrosis, apoptosis, and production of proinflammatory cytokines. Rapidly solidified (RS) thin ribbons were used for the tests. The control alloy was a permanent mold casting of the same composition, but without the shape memory effect. Our results showed that the control alloy was severely cytotoxic, whereas RS ribbons induced neither necrosis nor apoptosis of PMØ. These findings correlated with the data that RS ribbons are significantly more resistant to corrosion compared to the control alloy, as judged by the lesser release of Cu and Ni in the conditioning medium. However, the ribbons generated intracellular reactive oxygen species and upregulated the production of IL-6 by PMØ. These effects were almost completely abolished by conditioning the RS ribbons for 5 weeks. In conclusion, RS significantly improves the corrosion stability and biocompatibility of Cu-Al-Ni SMA. The biocompatibility of this functional material could be additionally enhanced by conditioning the ribbons in cell culture medium.

Impacts of amorphous and crystalline cobalt ferrite layers on the giant magneto-impedance response of a soft ferromagnetic amorphous ribbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mukherjee, D.; Devkota, J.; Ruiz, A.

2014-09-28

A systematic study of the effect of depositing CoFe₂O₄ (CFO) films of various thicknesses (d = 0–600 nm) on the giant magneto-impedance (GMI) response of a soft ferromagnetic amorphous ribbon Co₆₅Fe₄Ni₂Si₁₅B₁₄ has been performed. The CFO films were grown on the amorphous ribbons by the pulsed laser deposition technique. X-ray diffraction and transmission electron microscopy revealed a structural variation of the CFO film from amorphous to polycrystalline as the thickness of the CFO film exceeded a critical value of 300 nm. Atomic force microscopy evidenced the increase in surface roughness of the CFO film as the thickness of the CFOmore » film was increased. These changes in the crystallinity and morphology of the CFO film were found to have a distinct impact on the GMI response of the ribbon. Relative to the bare ribbon, coating of amorphous CFO films significantly enhanced the GMI response of the ribbon, while polycrystalline CFO films decreased it considerably. The maximum GMI response was achieved near the onset of the structural transition of the CFO film. These findings are of practical importance in developing high-sensitivity magnetic sensors.« less

Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking.

PubMed

Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

2016-01-01

In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. © 2016 Tang et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Concurrent gradients of ribbon volume and AMPA-receptor patch volume in cochlear afferent synapses on gerbil inner hair cells.

PubMed

Zhang, Lichun; Engler, Sina; Koepcke, Lena; Steenken, Friederike; Köppl, Christine

2018-07-01

The Mongolian gerbil is a classic animal model for age-related hearing loss. As a prerequisite for studying age-related changes, we characterized cochlear afferent synaptic morphology in young adult gerbils, using immunolabeling and quantitative analysis of confocal microscopic images. Cochlear wholemounts were triple-labeled with a hair-cell marker, a marker of presynaptic ribbons, and a marker of postsynaptic AMPA-type glutamate receptors. Seven cochlear positions covering an equivalent frequency range from 0.5 - 32 kHz were evaluated. The spatial positions of synapses were determined in a coordinate system with reference to their individual inner hair cell. Synapse numbers confirmed previous reports for gerbils (on average, 20-22 afferents per inner hair cell). The volumes of presynaptic ribbons and postsynaptic glutamate receptor patches were positively correlated: larger ribbons associated with larger receptor patches and smaller ribbons with smaller patches. Furthermore, the volumes of both presynaptic ribbons and postsynaptic receptor patches co-varied along the modiolar-pillar and the longitudinal axes of their hair cell. The gradients in ribbon volume are consistent with previous findings in cat, guinea pig, mouse and rat and further support a role in differentiating the physiological properties of type I afferents. However, the positive correlation between the volumes of pre- and postsynaptic elements in the gerbil is different to the opposing gradients found in the mouse, suggesting species-specific differences in the postsynaptic AMPA receptors that are unrelated to the fundamental classes of type I afferents. Copyright © 2018 Elsevier B.V. All rights reserved.

Inter-ribbon tunneling in graphene: An atomistic Bardeen approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van de Put, Maarten L., E-mail: maarten.vandeput@uantwerpen.be; Magnus, Wim; imec, B-3001 Heverlee

A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases inmore » current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states.« less

Hard magnetic property enhancement of Co{sub 7}Hf-based ribbons by boron doping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, H. W.; Liao, M. C.; Shih, C. W.

2014-11-10

Hard magnetic property enhancement of melt spun Co{sub 88}Hf{sub 12} ribbons by boron doping is demonstrated. B-doping could not only remarkably enhance the magnetic properties from energy product ((BH){sub max}) of 2.6 MGOe and intrinsic coercivity ({sub i}H{sub c}) of 1.5 kOe for B-free Co{sub 88}Hf{sub 12} ribbons to (BH){sub max} = 7.7 MGOe and {sub i}H{sub c} = 3.1 kOe for Co{sub 85}Hf{sub 12}B{sub 3} ribbons but also improve the Curie temperature (T{sub C}) of 7:1 phase. The (BH){sub max} value achieved in Co{sub 85}Hf{sub 12}B{sub 3} ribbons is the highest in Co-Hf alloy ribbons ever reported, which is about 15% higher thanmore » that of Co{sub 11}Hf{sub 2}B ribbons spun at 16 m/s [M. A. McGuire, O. Rios, N. J. Ghimire, and M. Koehler, Appl. Phys. Lett. 101, 202401 (2012)]. The structural analysis confirms that B enters the orthorhombic Co{sub 7}Hf (7:1) crystal structure as interstitial atoms, forming Co{sub 7}HfB{sub x}, in the as-spun state. Yet B may diffuse out from the 7:1 phase after post-annealing, leading to the reduction of Curie temperature and the magnetic properties. The uniformly refined microstructure with B-doping results in high remanence (B{sub r}) and improves the squareness of demagnetization curve. The formation of interstitial-atom-modified Co{sub 7}HfB{sub x} phase and the microstructure refinement are the main reasons to give rise to the enhancement of hard magnetic properties in the B-containing Co{sub 7}Hf-based ribbons.« less

The Lord Howe Rise continental ribbon: a fragment of eastern Gondwana that reveals the drivers of continental rifting and plate tectonics

NASA Astrophysics Data System (ADS)

Saito, S.; Hackney, R. I.; Bryan, S. E.; Kimura, J. I.; Müller, D.; Arculus, R. J.; Mortimer, N. N.; Collot, J.; Tamura, Y.; Yamada, Y.

2016-12-01

Plate tectonics and resulting changes in crustal architecture profoundly influence global climate, oceanic circulation, and the origin, distribution and sustainability of life. Ribbons of continental crust rifted from continental margins are one product of plate tectonics that can influence the Earth system. Yet we have been unable to fully resolve the tectonic setting and evolution of huge, thinned, submerged, and relatively inaccessible continental ribbons like the Lord Howe Rise (LHR), which formed during Cretaceous fragmentation of eastern Gondwana. Thinned continental ribbons like the LHR are not easily explained or predicted by plate-tectonic theory. However, because Cretaceous rift basins on the LHR preserve the stratigraphy of an un-accreted and intact continental ribbon, they can help to determine whether plate motion is self-organised—passively driven by the pull of negatively-buoyant subducting slabs—or actively driven by convective flow in the mantle. In a self-organising scenario, the LHR formed in response to ocean-ward retreat of the long-lived eastern Gondwana subduction zone and linked upper-plate extension. In the mantle-driven scenario, the LHR resulted from rifting near the eastern edge of Gondwana that was triggered by processes linked to emplacement of a silicic Large Igneous Province. These scenarios can be distinguished using the ribbon's extensional history and the composition and tectonic affinity of igneous rocks within rift basins. However, current knowledge of LHR rift basins is based on widely-distributed marine and satellite geophysical data, limited dredge samples, and sparse shallow drilling (<600 m below-seafloor). This limits our ability to understand the evolution of extended continental ribbons, but a recent deep crustal seismic survey across the LHR and a proposed IODP deep stratigraphic well through a LHR rift basin provide new opportunities to explore the drivers behind rifting, continental ribboning and plate tectonics.

A systems engineering initiative for NASA's space communications

NASA Technical Reports Server (NTRS)

Hornstein, Rhoda S.; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

1993-01-01

In addition to but separate from the Red and Blue Teams commissioned by the NASA Administrator, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper, without compromising safety. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo. The Blue Team process and results are summarized. The Associate Administrator for Space Communications subsequently convened a special management session to discuss the significance and implications of the Blue Team's report and to lay the groundwork and teamwork for the next steps, including the transition from engineering systems to systems engineering. The methodology and progress toward realizing the Code O Family vision and accomplishing the systems engineering initiative for NASA's space communications are presented.

Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayaraman, T. V.; Meka, V. M.; Jiang, X.

In this work, we investigated the ambient temperature structural properties (~300 K) and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties of melt-spun Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The thickness, width, lattice parameter, saturation magnetization (MS), and intrinsic coercivity (HCI) of the melt spun ribbons are presented and compared with data in the literature. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbonsmore » produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbons ranged between ~15-60 μm and 500-800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel-surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). Wheel surface speed was not shown to have a significant effect on the magnetization, but primarily impacted the ribbon structure. A decreasing trend in the saturation magnetization was observed as a function of increased silicon content. The intrinsic coercivity of the melt-spun alloys ranged between ~50 to 200 A/m. Elevated temperature evaluation of the magnetization in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The MS for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 – 900 K). The percentage decrease in MS from 300 K to 900 K for the Fe-3 wt.% Si and Fe-5 wt.% Si alloys was ~19-22 %, while the percentage decrease in the same temperature range for Fe-8 wt.% Si alloy was ~26-30 %. It appears that Fe-3 wt.% Si and Fe-5 wt.% Si alloys ribbons are primarily comprised of the α phase (disordered phase) with any minor constituents being beyond the detection limits of the studies performed, while the Fe-8 wt.% Si alloy ribbons are comprised of disordered and regions of short-range ordering.« less

BlueJ Visual Debugger for Learning the Execution of Object-Oriented Programs?

ERIC Educational Resources Information Center

Bennedsen, Jens; Schulte, Carsten

2010-01-01

This article reports on an experiment undertaken in order to evaluate the effect of a program visualization tool for helping students to better understand the dynamics of object-oriented programs. The concrete tool used was BlueJ's debugger and object inspector. The study was done as a control-group experiment in an introductory programming…

Using Evaluability Assessment to Improve Program Evaluation for the Blue-Throated Macaw Environmental Education Project in Bolivia

ERIC Educational Resources Information Center

Salvatierra da Silva, Daniela; Jacobson, Susan K.; Monroe, Martha C.; Israel, Glenn D.

2016-01-01

An evaluability assessment of a program to save a critically endangered bird helped prepare the Blue-throated Macaw Environmental Education Project for evaluation and program improvement. The evaluability assessment facilitated agreement among key stakeholders on evaluation criteria and intended uses of evaluation information in order to maximize…

Robotic Telesurgery Research

DTIC Science & Technology

2009-03-01

closed (right) positions. The upper jaw is constructed out of a super-elastic shape- memory nickel titanium alloy ( Nitinol ) ribbon (Memry Corporation...tissue. The Nitinol ribbon is glued to a fixed nylon rod insert that fits inside the bottom jaw. The nylon rod is also glued to the bottom jaw, and...configurations (bottom). The two collar pieces are connected to one another by two 0.12 mm thick Nitinol ribbons that are anchored to the collar walls. A

Michigan's Physician Group Incentive Program offers a regional model for incremental 'fee for value' payment reform.

PubMed

Share, David A; Mason, Margaret H

2012-09-01

Blue Cross Blue Shield of Michigan partnered with providers across the state to create an innovative, "fee for value" physician incentive program that would deliver high-quality, efficient care. The Physician Group Incentive Program rewards physician organizations-formal groups of physicians and practices that can accept incentive payments on behalf of their members-based on the number of quality and utilization measures they adopt, such as generic drug dispensing rates, and on their performance on these measures across their patient populations. Physicians also receive payments for implementing a range of patient-centered medical home capabilities, such as patient registries, and they receive higher fees for office visits for incorporating these capabilities into routine practice while also improving performance. Taken together, the incentive dollars, fee increases, and care management payments amount to a potential increase in reimbursement of 40 percent or more from Blue Cross Blue Shield of Michigan for practices designated as high-performing patient-centered medical homes. At the same time, we estimate that implementing the patient-centered medical home capabilities was associated with $155 million in lower medical costs in program year 2011 for Blue Cross Blue Shield of Michigan members. We intend to devote a higher percentage of reimbursement over time to communities of caregivers that offer high-value, system-based care, and a lower percentage of reimbursement to individual physicians on a service-specific basis.

Effect of short wavelength illumination on the characteristic bulk diffusion length in ribbon silicon solar cells

NASA Technical Reports Server (NTRS)

Ho, C. T.; Mathias, J. D.

1981-01-01

The influence of short wavelength light on the characteristic bulk minority carrier diffusion length of the ribbon silicon photovoltaic cell has been investigated. We have measured the intensity and wavelength dependence of the diffusion length in an EFG ribbon cell, and compared it with a standard Czochralski grown silicon cell. While the various short wavelength illuminations have shown no influence on the diffusion length in the CZ cell, the diffusion lengths in the ribbon cell exhibit a strong dependence on the volume generation rate as well as on the wavelength of the superimposed lights. We have concluded that the trap-filling phenomenon at various depths in the bulk neutral region of the cell is consistent with the experimental observation.

Bending effects on magnetic properties of nearly zeromagnetostrictive Co-rich amorphous ribbons

NASA Astrophysics Data System (ADS)

Buttino, G.; Cecchetti, A.; Poppi, M.; Zini, G.

1991-06-01

In as received nearly zeromagnetostriction Co-based Metglas, magnetic properties in low magnetic field are anomalously affected by bending stresses. The behavior of Co-based alloys, in particular 2714A Metglas, is here compared with that of Fe-rich Metglas for which λ s ranges between 10 × 10 -6 and 35 × 10 -6. The specimens here analyzed are in the form of flat ribbons and tape-wound toroids with different radii. In 2714A Metglas, the bending effects on the ac initial permeability are unexpectedly large and depend on the way of winding the ribbons. These results emphasize a significant and different role of the two ribbon sides in determining the magnetomechanical properties of Co-based alloys.

Deformation of fluctuating chiral ribbons

NASA Astrophysics Data System (ADS)

Panyukov, Sergey

2003-03-01

We find analytical solution of the model of a fluctuating filament with a spontaneously twisted noncircular cross section in the presence of external force and torque. We show that when such ribbon is subjected to a sufficiently strong extensional force, it exhibits an asymmetric response to large degrees of overwinding and unwinding. We construct the stability diagram that describes the buckling transition of such ribbons under the opposing action of force and torque and show that all the observed behaviors can be understood in terms of continuous transformations between straight and spiral states of the ribbon. The relation between our results and experimental observations on DNA is discussed and a new reentrant spiral to rod transition is predicted at intermediate values of twist rigidity and applied force.

Characteristics that Produce White-light Enhancements in Solar Flares Observed by Hinode/SOT

NASA Astrophysics Data System (ADS)

Watanabe, Kyoko; Kitagawa, Jun; Masuda, Satoshi

2017-12-01

To understand the conditions that produce white-light (WL) enhancements in solar flares, a statistical analysis of visible continuum data as observed by Hinode/Solar Optical Telescope (SOT) was performed. In this study, approximately 100 flare events from M- and X-class flares were selected. The time period during which the data were recorded spans from 2011 January to 2016 February. Of these events, approximately half are classified as white-light flares (WLFs), whereas the remaining events do not show any enhancements of the visible continuum (non-WLF; NWL). To determine the existence of WL emission, running difference images of not only the Hinode/SOT WL (G-band, blue, green, and red filter) data, but also the Solar Dynamics Observatory/Helioseismic and Magnetic Imager continuum data are used. A comparison between these two groups of WL data in terms of duration, temperature, emission measure of GOES soft X-rays, distance between EUV flare ribbons, strength of hard X-rays, and photospheric magnetic field strength was undertaken. In this statistical study, WLF events are characterized by a shorter timescale and shorter ribbon distance compared with NWL events. From the scatter plots of the duration of soft X-rays and the energy of non-thermal electrons, a clear distinction between WLF and NWL events can be made. It is found that the precipitation of large amounts of accelerated electrons within a short time period plays a key role in generating WL enhancements. Finally, it was demonstrated that the coronal magnetic field strength in the flare region is one of the most important factors that allow the individual identification of WLF events from NWL events.

Re-engineering NASA's space communications to remain viable in a constrained fiscal environment

NASA Astrophysics Data System (ADS)

Hornstein, Rhoda Shaller; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

1994-11-01

Along with the Red and Blue Teams commissioned by the NASA Administrator in 1992, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo, including current work processes, functional distinctions, interfaces, and information flow, as well as traditional management and system development practices. The Blue Team's unconstrained, non-parochial, and imaginative look at NASA's space communications program produced a simplified representation of the space communications infrastructure that transcends organizational and functional boundaries, in addition to existing systems and facilities. Further, the Blue Team adapted the 'faster, better, cheaper' charter to be relevant to the multi-mission, continuous nature of the space communications program and to serve as a gauge for improving customer services concurrent with achieving more efficient operations and infrastructure life cycle economies. This simplified representation, together with the adapted metrics, offers a future view and process model for reengineering NASA's space communications to remain viable in a constrained fiscal environment. Code O remains firm in its commitment to improve productivity, effectiveness, and efficiency. In October 1992, the Associate Administrator reconstituted the Blue Team as the Code O Success Team (COST) to serve as a catalyst for change. In this paper, the COST presents the chronicle and significance of the simplified representation and adapted metrics, and their application during the FY 1993-1994 activities.

Re-engineering NASA's space communications to remain viable in a constrained fiscal environment

NASA Technical Reports Server (NTRS)

Hornstein, Rhoda Shaller; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

1994-01-01

Along with the Red and Blue Teams commissioned by the NASA Administrator in 1992, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo, including current work processes, functional distinctions, interfaces, and information flow, as well as traditional management and system development practices. The Blue Team's unconstrained, non-parochial, and imaginative look at NASA's space communications program produced a simplified representation of the space communications infrastructure that transcends organizational and functional boundaries, in addition to existing systems and facilities. Further, the Blue Team adapted the 'faster, better, cheaper' charter to be relevant to the multi-mission, continuous nature of the space communications program and to serve as a gauge for improving customer services concurrent with achieving more efficient operations and infrastructure life cycle economies. This simplified representation, together with the adapted metrics, offers a future view and process model for reengineering NASA's space communications to remain viable in a constrained fiscal environment. Code O remains firm in its commitment to improve productivity, effectiveness, and efficiency. In October 1992, the Associate Administrator reconstituted the Blue Team as the Code O Success Team (COST) to serve as a catalyst for change. In this paper, the COST presents the chronicle and significance of the simplified representation and adapted metrics, and their application during the FY 1993-1994 activities.

KSC-98pc783

NASA Image and Video Library

1998-07-06

KSC Center Director Roy D. Bridges Jr. and U.S. Congressman Dave Weldon (holding scissors) cut the ribbon at a ceremony on July 6 to open KSC's new 34,600-square-foot Space Shuttle Main Engine Processing Facility (SSMEPF). Joining in the ribbon cutting are (left) Ed Adamek, vice president and associate program manager for Ground Operations of United Space Alliance; Marvin L. Jones, director of Installation Operations; Donald R. McMonagle, manager of Launch Integration; (right) Wade Ivey of Ivey Construction, Inc.; Robert B. Sieck, director of Shuttle Processing; and John Plowden, vice president of Rocketdyne. A major addition to the existing Orbiter Processing Facility Bay 3, the SSMEPF replaces the Shuttle Main Engine Shop located in the Vehicle Assembly Building (VAB). The decision to move the shop out of the VAB was prompted by safety considerations and recent engine processing improvements. The first three main engines to be processed in the new facility will fly on Shuttle Endeavour's STS-88 mission in December 1998

The ribbon-cutting ceremony unveils the reactivated altitude chamber inside the O&C high bay

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Operations and Checkout Building high bay, Center Director Roy Bridges remarks on the accomplishment of the joint NASA/Boeing team in renovating an altitude chamber formerly used on the Apollo program. Project team members, management, media and onlookers are present for the ribbon cutting. The chamber was reactivated, after a 24-year hiatus, to perform leak tests on International Space Station pressurized modules at the launch site. Originally, two chambers were built to test the Apollo command and lunar service modules. They were last used in 1975 during the Apollo-Soyuz Test Project. After installation of new vacuum pumping equipment and controls, a new control room, and a new rotation handling fixture, the chamber again became operational in February 1999. The chamber, which is 33 feet in diameter and 50 feet tall, is constructed of stainless steel. The first module that will be tested for leaks is the U.S. Laboratory. No date has been determined for the test.

The SSMEPF opens with a ribbon-cutting ceremony

NASA Technical Reports Server (NTRS)

1998-01-01

Participants in the ribbon cutting for KSC's new 34,600-square- foot Space Shuttle Main Engine Processing Facility (SSMEPF) pose in front of a Space Shuttle Main Engine on display for the ceremony. From left, they are Ed Adamek, vice president and associate program manager for Ground Operations of United Space Alliance; John Plowden, vice president of Rocketdyne; Donald R. McMonagle, manager of Launch Integration; U.S. Congressman Dave Weldon; KSC Center Director Roy D. Bridges Jr.; Wade Ivey of Ivey Construction, Inc.; and Robert B. Sieck, director of Shuttle Processing. A major addition to the existing Orbiter Processing Facility Bay 3, the SSMEPF replaces the Shuttle Main Engine Shop located in the Vehicle Assembly Building (VAB). The decision to move the shop out of the VAB was prompted by safety considerations and recent engine processing improvements. The first three main engines to be processed in the new facility will fly on Shuttle Endeavour's STS-88 mission in December 1998.

Silicon web process development. [for low cost solar cells

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Hopkins, R. H.; Seidensticker, R. G.; Mchugh, J. P.; Hill, F. E.; Heimlich, M. E.; Driggers, J. M.

1979-01-01

Silicon dendritic web, a single crystal ribbon shaped during growth by crystallographic forces and surface tension (rather than dies), is a highly promising base material for efficient low cost solar cells. The form of the product smooth, flexible strips 100 to 200 microns thick, conserves expensive silicon and facilitates automation of crystal growth and the subsequent manufacturing of solar cells. These characteristics, coupled with the highest demonstrated ribbon solar cell efficiency-15.5%-make silicon web a leading candidate to achieve, or better, the 1986 Low Cost Solar Array (LSA) Project cost objective of 50 cents per peak watt of photovoltaic output power. The main objective of the Web Program, technology development to significantly increase web output rate, and to show the feasibility for simultaneous melt replenishment and growth, have largely been accomplished. Recently, web output rates of 23.6 sq cm/min, nearly three times the 8 sq cm/min maximum rate of a year ago, were achieved. Webs 4 cm wide or greater were grown on a number of occassions.

Assessment of a Post-deployment Yellow Ribbon Reintegration Program for National Guard Members and Supporters

PubMed Central

Scherrer, Jeffrey F.; Widner, Greg; Shroff, Manan; Matthieu, Monica; Balan, Sundari; van den Berk-Clark, Carissa; Price, Rumi Kato

2014-01-01

The Yellow Ribbon Reintegration Program (YRRP) was created to meet the needs of National Guard members and their families throughout the deployment cycle. This study examined the perceived utility of the YRRP’s delivery of information and assistance during the post-deployment reintegration period by National Guard members and accompanying supporters who were mostly spouses. Over 22 months, from 10 YRRP events, 683 service members and 411 supporters completed questionnaires immediately after the YRRP. We analyzed questions on information and help provision, timeliness and concerns related to education, employment, legal, family, and health. Service members and supporters most often endorsed education needs being met (76.8% and 78.2% respectively) and were least likely to endorse legal needs being met (63.5% and 60% respectively). Significantly more supporters than service members (p < 0.0001) reported that the YRRP was the first time they learned of available services across all domains. Service members were significantly more likely than supporters to report concerns about education, employment, and health; while supporters were significantly more likely to report concerns about family. Results suggest the YRRP fills gaps in supporter knowledge and provides needed information and resources to most National Guard families 2-4 months after a deployment. PMID:25373071

Assessment of a postdeployment Yellow Ribbon Reintegration Program for National Guard members and supporters.

PubMed

Scherrer, Jeffrey F; Widner, Greg; Shroff, Manan; Matthieu, Monica; Balan, Sundari; van den Berk-Clark, Carissa; Price, Rumi K

2014-11-01

The Yellow Ribbon Reintegration Program (YRRP) was created to meet the needs of National Guard members and their families throughout the deployment cycle. This study examined the perceived utility of the YRRP's delivery of information and assistance during the postdeployment reintegration period by National Guard members and accompanying supporters who were mostly spouses. Over 22 months, from 10 YRRP events, 683 service members and 411 supporters completed questionnaires immediately after the YRRP. We analyzed questions on information and avenues for help, timeliness and concerns related to education, employment, legal, family, and health. Service members and supporters most often endorsed information delivery on education being met (76.8% and 78.2%, respectively) and were least likely to endorse legal information delivery (63.5% and 60%, respectively). Significantly more supporters than service members (p < 0.0001) reported that the YRRP was the first time they learned of available services across all domains. Service members were significantly more likely than supporters to report concerns about education, employment, and health, while supporters were significantly more likely to report concerns about family. Results suggest the YRRP fills gaps in supporter knowledge and provides needed information and resources to most National Guard families 2 to 4 months after a deployment. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

The Role of Pickup Ion Dynamics Outside of the Heliopause in the Limit of Weak Pitch Angle Scattering: Implications for the Source of the IBEX Ribbon.

PubMed

Zirnstein, E J; Heerikhuisen, J; Dayeh, M A

2018-01-01

We present a new model of the Interstellar Boundary Explorer ( IBEX ) ribbon based on the secondary energetic neutral atom (ENA) mechanism, under the assumption that there is negligible pitch angle scattering of pickup ions (PUIs) outside the heliopause. Using the results of an MHD-plasma/kinetic-neutral simulation of the heliosphere, we generate PUIs in the outer heliosheath, solve their transport using guiding center theory, and compute ribbon ENA fluxes at 1 AU. We implement several aspects of the PUI dynamics, including (1) parallel motion along the local interstellar magnetic field (ISMF), (2) advective transport with the interstellar plasma, (3) the mirror force acting on PUIs propagating along the ISMF, and (4) betatron acceleration of PUIs as they are advected within an increasing magnetic field towards the heliopause. We find that ENA fluxes at 1 AU are reduced when PUIs are allowed to move along the ISMF, and ENA fluxes are reduced even more by the inclusion of the mirror force, which pushes particles away from IBEX lines-of-sight. Inclusion of advection and betatron acceleration do not result in any significant change in the ribbon. Interestingly, the mirror force reduces the ENA fluxes from the inner edge of the ribbon more than its outer edge, effectively reducing the ribbon's width by ∼6° and increasing its radius projected on the sky. This is caused by the asymmetric draping of the ISMF around the heliopause, such that ENAs from the ribbon's inner edge originate closer to the heliopause, where the mirror force is strongest.

Calmodulin enhances ribbon replenishment and shapes filtering of synaptic transmission by cone photoreceptors

PubMed Central

Parmelee, Caitlyn M.; Chen, Minghui; Cork, Karlene M.; Curto, Carina; Thoreson, Wallace B.

2014-01-01

At the first synapse in the vertebrate visual pathway, light-evoked changes in photoreceptor membrane potential alter the rate of glutamate release onto second-order retinal neurons. This process depends on the synaptic ribbon, a specialized structure found at various sensory synapses, to provide a supply of primed vesicles for release. Calcium (Ca2+) accelerates the replenishment of vesicles at cone ribbon synapses, but the mechanisms underlying this acceleration and its functional implications for vision are unknown. We studied vesicle replenishment using paired whole-cell recordings of cones and postsynaptic neurons in tiger salamander retinas and found that it involves two kinetic mechanisms, the faster of which was diminished by calmodulin (CaM) inhibitors. We developed an analytical model that can be applied to both conventional and ribbon synapses and showed that vesicle resupply is limited by a simple time constant, τ = 1/(Dρδs), where D is the vesicle diffusion coefficient, δ is the vesicle diameter, ρ is the vesicle density, and s is the probability of vesicle attachment. The combination of electrophysiological measurements, modeling, and total internal reflection fluorescence microscopy of single synaptic vesicles suggested that CaM speeds replenishment by enhancing vesicle attachment to the ribbon. Using electroretinogram and whole-cell recordings of light responses, we found that enhanced replenishment improves the ability of cone synapses to signal darkness after brief flashes of light and enhances the amplitude of responses to higher-frequency stimuli. By accelerating the resupply of vesicles to the ribbon, CaM extends the temporal range of synaptic transmission, allowing cones to transmit higher-frequency visual information to downstream neurons. Thus, the ability of the visual system to encode time-varying stimuli is shaped by the dynamics of vesicle replenishment at photoreceptor synaptic ribbons. PMID:25311636

Low-loss terahertz ribbon waveguides.

PubMed

Yeh, Cavour; Shimabukuro, Fred; Siegel, Peter H

2005-10-01

The submillimeter wave or terahertz (THz) band (1 mm-100 microm) is one of the last unexplored frontiers in the electromagnetic spectrum. A major stumbling block hampering instrument deployment in this frequency regime is the lack of a low-loss guiding structure equivalent to the optical fiber that is so prevalent at the visible wavelengths. The presence of strong inherent vibrational absorption bands in solids and the high skin-depth losses of conductors make the traditional microstripline circuits, conventional dielectric lines, or metallic waveguides, which are common at microwave frequencies, much too lossy to be used in the THz bands. Even the modern surface plasmon polariton waveguides are much too lossy for long-distance transmission in the THz bands. We describe a concept for overcoming this drawback and describe a new family of ultra-low-loss ribbon-based guide structures and matching components for propagating single-mode THz signals. For straight runs this ribbon-based waveguide can provide an attenuation constant that is more than 100 times less than that of a conventional dielectric or metallic waveguide. Problems dealing with efficient coupling of power into and out of the ribbon guide, achieving low-loss bends and branches, and forming THz circuit elements are discussed in detail. One notes that active circuit elements can be integrated directly onto the ribbon structure (when it is made with semiconductor material) and that the absence of metallic structures in the ribbon guide provides the possibility of high-power carrying capability. It thus appears that this ribbon-based dielectric waveguide and associated components can be used as fundamental building blocks for a new generation of ultra-high-speed electronic integrated circuits or THz interconnects.

Antiguided fiber ribbon laser

DOEpatents

Wilcox, Russel B [El Cerrito, CA; Page, Ralph H [Castro Valley, CA; Beach, Raymond J [Livermore, CA; Feit, Michael D [Livermore, CA; Payne, Stephen A [Castro Valley, CA

2003-05-27

The invention is a ribbon of an optical material with a plurality of cores that run along its length. The plurality of cores includes lasing impurity doped cores in an alternating spaced arrangement with index-modifying impurity doped cores. The ribbon comprises an index of refraction that is substantially equal to or greater than the indices of refraction of said array of lasing impurity doped cores. Index-increasing impurity doped cores promote antiguiding and leaky modes which provide more robust single "supermode" operation.

Evaluation of ULV Applications Against Old World Sand Fly (Diptera: Psychodidae) Species in Equatorial Kenya

DTIC Science & Technology

2011-01-01

patterns of UV-labeled droplets captured on cotton ribbons adjacent to sand ßy cages in spray plots did not match patterns ofmortality.Wediscuss the...untreated areas. Surprisingly, ULV active ingredient deposition inferred from patterns of UV-labeled droplets captured on cotton ribbons adjacent to...the west plot on the second spray day; looking south. Cotton droplet capture ribbons have already been attached in position between the posts at each

Shape Memory Characteristics of Rapidly Solidified Ti-37.8Cu-18.7Ni Alloy Ribbons

NASA Astrophysics Data System (ADS)

Ramos, Alana Pereira; de Castro, Walman Benicio

Amorphization and martensitic transformation (Ms) characteristics of Ti-Ni-Cu alloy ribbons prepared by melt spinning were investigated by means of differential scanning calorimetry and X-ray diffraction. In these experiments particular attention has been paid to change the wheel linear velocity from 21 to 63 m/s. Then the cooling rates of ribbons were controlled. The effect of this cooling rate and alloy composition on martensitic transformation behavior is discussed.

Spontaneous Periodic Delamination of Thin Films To Form Crack-Free Metal and Silicon Ribbons with High Stretchability.

PubMed

Zhang, Qiuting; Tang, Yichao; Hajfathalian, Maryam; Chen, Chunxu; Turner, Kevin T; Dikin, Dmitriy A; Lin, Gaojian; Yin, Jie

2017-12-27

Design of electronic materials with high stretchability is of great importance for realizing soft and conformal electronics. One strategy of realizing stretchable metals and semiconductors is to exploit the buckling of materials bonded to elastomers. However, the level of stretchability is often limited by the cracking and fragmentation of the materials that occurs when constrained buckling occurs while bonded to the substrate. Here, we exploit a failure mechanism, spontaneous buckling-driven periodic delamination, to achieve high stretchability in metal and silicon films that are deposited on prestrained elastomer substrates. We find that both globally periodic buckle-delaminated pattern and ordered cracking patterns over large areas are observed in the spontaneously buckle-delaminated thin films. The geometry of periodic delaminated buckles and cracking periodicity can be predicted by theoretical models. By patterning the films into ribbons with widths smaller than the predicted cracking periodicity, we demonstrate the design of crack-free and spontaneous delaminated ribbons on highly prestrained elastomer substrates, which provides a high stretchability of about 120% and 400% in Si and Au ribbons, respectively. We find that the high stretchability is mainly attributed to the largely relaxed strain in the ribbons via spontaneous buckling-driven delamination, as made evident by the small maximum tensile strain in both ribbons, which is measured to be over 100 times smaller than that of the substrate prestrain.

RIBEYE(B)-domain binds to lipid components of synaptic vesicles in an NAD(H)-dependent, redox-sensitive manner.

PubMed

Schwarz, Karin; Schmitz, Frank

2017-03-20

Synaptic ribbons are needed for fast and continuous exocytosis in ribbon synapses. RIBEYE is a main protein component of synaptic ribbons and is necessary to build the synaptic ribbon. RIBEYE consists of a unique A-domain and a carboxyterminal B-domain, which binds NAD(H). Within the presynaptic terminal, the synaptic ribbons are in physical contact with large numbers of synaptic vesicle (SV)s. How this physical contact between ribbons and synaptic vesicles is established at a molecular level is not well understood. In the present study, we demonstrate that the RIBEYE(B)-domain can directly interact with lipid components of SVs using two different sedimentation assays with liposomes of defined chemical composition. Similar binding results were obtained with a SV-containing membrane fraction. The binding of liposomes to RIBEYE(B) depends upon the presence of a small amount of lysophospholipids present in the liposomes. Interestingly, binding of liposomes to RIBEYE(B) depends on NAD(H) in a redox-sensitive manner. The binding is enhanced by NADH, the reduced form, and is inhibited by NAD + , the oxidized form. Lipid-mediated attachment of vesicles is probably part of a multi-step process that also involves additional, protein-dependent processes. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Ribbons of semithin sections: an advanced method with a new type of diamond knife.

PubMed

Blumer, Michael J F; Gahleitner, P; Narzt, T; Handl, C; Ruthensteiner, B

2002-10-15

Complete series of semithin sections are imperative for 3-D reconstruction, but with traditional microtomy techniques it is difficult and time-consuming to trace stained and labeled structures. In the present study we introduce a method for making and collecting ribbons of semithin sections with a new, commercial available diamond knife (histo-jumbo-diamond knife, Diatome AG, Biel, Switzerland). The special feature of the diamond knife is the large water bath (boat) into which a glass slide can be dipped. The method has distinct advantages and the handling is simple. The resin block is trimmed into a truncated pyramid. Contact glue is applied to the leading face of the pyramid, which makes sections stick together to form a ribbon. Following sectioning, the ribbons are mounted onto glass slides and aligned in parallel. Stretching out and drying the ribbons on a hot plate is the final step of the method. Major advantages of this method are the perfect alignment of sections with identical orientation of structures, the completeness of series, and the significant saving of time. This facilitates tracing of stained and labeled structures, yielding quick 3-D reconstruction. Semithin sections can be cut from 0.5 to 2 micro m and several ribbons can be mounted side by side onto the slide. Two examples are presented to illustrate the advantages of the method.

Structure and magnetic properties of Alnico ribbons

NASA Astrophysics Data System (ADS)

Zhang, Ce; Li, Ying; Han, Xu-Hao; Du, Shuai-long; Sun, Ji-bing; Zhang, Ying

2018-04-01

Al-Ni-Co alloy has been widely applied in various industrial fields due to its excellent thermal and magnetic stability. In this paper, new Al-Ni-Co ribbons are prepared by simple processes combining melt-spinning with annealing, and their phase transition, microstructure and magnetic properties are studied. The results show that after as-spun ribbons are annealed, the grain size of ribbons increases from 1.1 ± 0.3 μm to 4.8 ± 0.8 μm, but still much smaller than that of the bulk Al-Ni-Co alloy manufactured by traditional technologies. In addition, some rod-like Al70Co20Ni10-type, Al9Co2-type and Fe2Nb-type phases are precipitated at grain boundaries; simultaneously, the distinct spinodal decomposition microstructure with periodic ingredient variation is thoroughly formed in all grains by the reaction of α → α1 + α2. Furthermore, the α1 and α2 distribute alternately like a maze, the Fe-Co-rich α1 phase holds 35.9-47.3 vol%, while the Al-Ni-rich α2 phase occupies the rest. Finally, the coercivity of annealed ribbons can reach to 485.3 ± 76.6 Oe. If the annealed ribbons are further aged at 560 °C, their Hc even increases to 738.1 ± 81.0 Oe. The coercivity mechanism is discussed by the combination of microstructure and domain structure.

Adiabatic magnetocaloric effect in Ni50Mn35In15 ribbons

NASA Astrophysics Data System (ADS)

Álvarez-Alonso, P.; Aguilar-Ortiz, C. O.; Camarillo, J. P.; Salazar, D.; Flores-Zúñiga, H.; Chernenko, V. A.

2016-11-01

Heusler-type Ni-Mn-based metamagnetic shape memory alloys (MetaMSMAs) are promising candidates for magnetic refrigeration. To increase heat exchange rate and efficiency of cooling, the material should have a high surface/volume ratio. In this work, the typical Ni50Mn35In15 MetaMSMA was selected to fabricate thin ribbons by melt-spinning. The characteristic transformations of the ribbons were determined by calorimetry, X-ray diffraction, scanning electron microscopy and thermomagnetization measurements. The inverse and conventional magnetocaloric effects (MCEs) associated with the martensitic transformation (MT) and the ferromagnetic transition of the austenite (TCA), respectively, were measured directly by the adiabatic method (ΔTad) and indirectly by estimating the magnetic entropy change from magnetization measurements. It is found that the ribbons exhibit large values of ΔTad = -1.1 K at μ0ΔH = 1.9 T, in the vicinity of the MT temperature of 300 K for inverse MCE, and ΔTad = 2.3 K for conventional MCE at TCA = 309 K. This result strongly motivates further development of different MetaMSMA refrigerants shaped as ribbons.

Electromigration process for the purification of molten silicon during crystal growth

DOEpatents

Lovelace, Alan M. Administrator of the National Aeronautics and Space; Shlichta, Paul J.

1982-01-01

A process for the purification of molten materials during crystal growth by electromigration of impurities to localized dirty zones. The process has particular applications for silicon crystal growth according to Czochralski techniques and edge-defined film-fed growth (EFG) conditions. In the Czochralski crystal growing process, the impurities are electromigrated away from the crystallization interface by applying a direct electrical current to the molten silicon for electromigrating the charged impurities away from the crystal growth interface. In the EFG crystal growth process, a direct electrical current is applied between the two faces which are used in forming the molten silicon into a ribbon. The impurities are thereby migrated to one side only of the crystal ribbon. The impurities may be removed or left in place. If left in place, they will not adversely affect the ribbon when used in solar collectors. The migration of the impurity to one side only of the silicon ribbon is especially suitable for use with asymmetric dies which preferentially crystallize uncharged impurities along one side or face of the ribbon.

Low field magnetocaloric effect in bulk and ribbon alloy La(Fe0.88Si0.12)13

NASA Astrophysics Data System (ADS)

Vuong, Van-Hiep; Do-Thi, Kim-Anh; Nguyen, Duy-Thien; Nguyen, Quang-Hoa; Hoang, Nam-Nhat

2018-03-01

Low-field magnetocaloric effect occurred in itinerant metamagnetic materials is at core for magnetic cooling application. This works reports the magnetocaloric responses obtained at 1.35 T for the silicon-doped iron-based binary alloy La(Fe0.88Si0.12)13 in the bulk and ribbon form. Both samples possess a same symmetry but with different crystallite sizes and lattice parameters. The ribbon sample shows a larger maximum entropy change (nearly 8.5 times larger) and a higher Curie temperature (5 K higher) in comparison with that of the bulk sample. The obtained relative cooling power for the ribbon is also larger and very promising for application (RCP = 153 J/kg versus 25.2 J/kg for the bulk). The origin of the effect observed is assigned to the occurrence of negative magnetovolume effect in the ribbon structure with limit crystallization, caused by rapid cooling process at the preparation, which induced smaller crystallite size and large lattice constant at the overall weaker local crystal field.

Mass distribution and spatial organization of the linear bacterial motor of Spiroplasma citri R8A2.

PubMed

Trachtenberg, Shlomo; Andrews, S Brian; Leapman, Richard D

2003-03-01

In the simple, helical, wall-less bacterial genus Spiroplasma, chemotaxis and motility are effected by a linear, contractile motor arranged as a flat cytoskeletal ribbon attached to the inner side of the membrane along the shortest helical line. With scanning transmission electron microscopy and diffraction analysis, we determined the hierarchical and spatial organization of the cytoskeleton of Spiroplasma citri R8A2. The structural unit appears to be a fibril, approximately 5 nm wide, composed of dimers of a 59-kDa protein; each ribbon is assembled from seven fibril pairs. The functional unit of the intact ribbon is a pair of aligned fibrils, along which pairs of dimers form tetrameric ring-like repeats. On average, isolated and purified ribbons contain 14 fibrils or seven well-aligned fibril pairs, which are the same structures observed in the intact cell. Scanning transmission electron microscopy mass analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified cytoskeletons indicate that the 59-kDa protein is the only constituent of the ribbons.

Laser-zone growth in a Ribbon-To-Ribbon (RTR) process. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Gurtler, R. W.; Baghdadi, A.; Legge, R.; Sopori, B.; Ellis, R. J.

1977-01-01

The Ribbon-to-Ribbon (RTR) approach to silicon ribbon growth is investigated. An existing RTR apparatus is to be upgraded to its full capabilities and operated routinely to investigate and optimize the effects of various growth parameters on growth results. A new RTR apparatus was constructed to incorporate increased capabilities and improvements over the first apparatus and to be capable of continuous growth. New high power lasers were implemented and this led to major improvements in growth velocity -- 4 inch/min. growth has been demonstrated. A major step in demonstration of the full feasibility of the RTR process is reported in the demonstration of RTR growth from CVD polyribbon rather than sliced polyribbon ingots. Average solar cell efficiencies of greater than 9% and a best cell efficiency of 11.7% are reported. Processing was shown to provide a substantial improvement in material minority carrier diffusion length. An economic analysis is reported which treats both the polyribbon fabrication and RTR processes.

Effect of Sm content on energy product of rapidly quenched and oriented SmCo5 ribbons

NASA Astrophysics Data System (ADS)

Zhang, Wenyong; Li, Xingzhong; Valloppilly, Shah

2015-03-01

The Sm-content dependence of phase composition, anisotropy, and other magnetic properties of Sm1+ δ Co5 ( δ ≤ 0.12) ribbons melt spun at 10 m/s has been studied. The samples consist of hexagonal SmCo5 grains whose c axes are preferentially aligned along the long direction of the ribbon. The lattice parameter a and the cell volume ( V) increase with increasing Sm content δ, whereas c decreases. Sm addition appears to improve the degree of the preferred orientation of the c-axis and to increase the mean grain size, which weakens the effective intergranular exchange coupling. Therefore, the remanence ratio, coercivity, and squareness of the hysteresis loops are significantly enhanced. The remanence ratio of 0.91 and the maximum energy product of 21.2 MGOe, which is the highest value reported so far for Sm-Co ribbons, are achieved for δ = 0.06. High performance in combination with simple processing may facilitate high-temperature applications for anisotropic Sm1+ δ Co5 ribbons.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-10-05

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Extrusion of metal oxide superconducting wire, tube or ribbon

DOEpatents

Dusek, Joseph T.

1993-01-01

A process for extruding a superconducting metal oxide composition YBa.sub.2 Cu.sub.3 O.sub.7-x provides a wire (tube or ribbon) having a cohesive mass and a degree of flexibility together with enhanced electrical properties. Wire diameters in the range of 6-85 mils have been produced with smaller wires on the order of 10 mils in diameter exhibiting enhanced flexibility for forming braided, or multistrand, configurations for greater current carrying capacity. The composition for extrusion contains a polymeric binder to provide a cohesive mass to bind the particles together during the extrusion process with the binder subsequently removed at lower temperatures during sintering. The composition for extrusion further includes a deflocculent, an organic plasticizer and a solvent which also are subsequently removed during sintering. Electrically conductive tubing with an inner diameter of 52 mil and an outer diameter of 87-355 mil has also been produced. Flat ribbons have been produced in the range of 10-125 mil thick by 100-500 mil wide. The superconducting wire, tube or ribbon may include an outer ceramic insulating sheath co-extruded with the wire, tubing or ribbon.

Effects of Zr on microstructure and mechanical properties of Al-Cu base ribbons spun by planar flow casting

NASA Astrophysics Data System (ADS)

Lee, S. M.; Hong, C. P.

1998-04-01

The effects of the Zr addition on the solidification behavior and mechanical properties of the AI-Cu alloy ribbon have been investigated. Zr addition reduced the average grain size of the ribbon at the wheel-side surface, and promoted the microstructural transition into cellular/dendritic structure. Another noteworthy effect of Zr was the homogenization of the microstructure. The addition of Zr up to 0.5 wt.% in the /U-4.3 wt.% Cu ribbon resulted in a considerable increase in hardness at both the wheel-side and the air-side surfaces. The yield strength increased with the addition of Zr due to the grain refincment and more homogeneous distribution of ZrAI, particles. despite no noticeable improvement of the ductility.

Shape selection of twist-nematic-elastomer ribbons

PubMed Central

Sawa, Yoshiki; Ye, Fangfu; Urayama, Kenji; Takigawa, Toshikazu; Gimenez-Pinto, Vianney; Selinger, Robin L. B.; Selinger, Jonathan V.

2011-01-01

How microscopic chirality is reflected in macroscopic scale to form various chiral shapes, such as straight helicoids and spiral ribbons, and how the degree of macroscopic chirality can be controlled are a focus of studies on the shape formation of many biomaterials and supramolecular systems. This article investigates both experimentally and theoretically how the chiral arrangement of liquid crystal mesogens in twist-nematic-elastomer films induces the formation of helicoids and spiral ribbons because of the coupling between the liquid crystalline order and the elasticity. It is also shown that the pitch of the formed ribbons can be tuned by temperature variation. The results of this study will facilitate the understanding of physics for the shape formation of chiral materials and the designing of new structures on basis of microscopic chirality. PMID:21464276

A new analysis of the unwinding ribbon as a delayed arming device

NASA Astrophysics Data System (ADS)

Dunn, W. P.

1982-06-01

The objective of this work was to formulate theoretical methods to enable engineers to design unwinding ribbons for use as delay arming mechanisms with reasonable accuracy and a minimum development effort. The unwinding ribbon considered here is a "wrapped' spring, which is a spiral spring made from flat metal stock closely wound. In the unstressed condition all the coils of the spring are touching. The results of the analysis are given and compared with the experimental results obtained by T. B. Alfriend. This is a more complete study than that of Alfriend since no assumptions are made concerning the moment of inertia of the coil and hub or the tension force in the ribbon bridge. Hence, two empirical constants in Alfriend's analysis were dropped in favor of exact expressions.

On the deformation of fluctuating chiral ribbons

NASA Astrophysics Data System (ADS)

Panyukov, S.; Rabin, Y.

2002-02-01

A theoretical analysis of the effect of force and torque on fluctuating chiral ribbons is presented. We find that when a filament with a straight centerline and a spontaneously twisted noncircular cross-section is subjected to a sufficiently strong extensional force, it exhibits an asymmetric response to large degrees of overwinding and unwinding. We construct the stability diagram that describes the buckling transition of such ribbons under the opposing action of force and torque and show that all the observed behaviors can be understood in terms of continuous transformations between straight and spiral states of the ribbon. The relation between our results and experimental observations on DNA is discussed and a new re-entrant spiral-to-rod transition is predicted at intermediate values of twist rigidity and applied force.

SSPF Operational Upgrades

NASA Image and Video Library

2016-11-15

During a ribbon cutting ceremony in the high bay of the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, center director Bob Cabana, far left, is joined by Bill Dowdell, Kennedy's International Space Station technical director, Josephine Burnett, director of Exploration Research and Technology, Andy Allen, Jacobs vice president and general manager and Test and Operations Support Contract program manager, and Jeff McAlear, Jacobs director of Processing Services. The event celebrated completion of facility modifications to improve processing and free up zones tailored to a variety of needs supporting a robust assortment of space-bound hardware including NASA programs and commercial space companies.

HRTEM and neutron diffraction study of Li{sub x}Mo{sub 5}O{sub 17}: From the ribbon (x=5) structure to the rock salt (x=12) structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebedev, O.I.; Caignaert, V.; Raveau, B.

2011-04-15

Structure determination of the fully intercalated phase Li{sub 12}Mo{sub 5}O{sub 17} and of the deintercalated oxide Li{sub 5}Mo{sub 5}O{sub 17} has been carried out by electron microscopy and neutron powder diffraction. The reversible topotactic transformation between the ordered rock salt structure of the former and the ribbon structure of the latter (closely related to that of Li{sub 4}Mo{sub 5}O{sub 17}) is explained on the following basis: both structures can be described as strips built up as an assembly of infinite ribbons of MoO{sub 6} octahedra that are five octahedra thick, and that differ by slight displacements of the octahedral ribbons.more » We show that the electrochemical behavior of the Li{sub x}Mo{sub 5}O{sub 17} system is based on two sorts of Li{sup +} sites; those that are located within the strips between the ribbons, and those that are located at the border of the strips. The high rate of Li intercalation in this oxide and its reversibility are discussed in terms of its peculiar structure. -- Graphical abstract: Structure determination of the fully intercalated phase Li{sub 12}Mo{sub 5}O{sub 17} and of the deintercalated oxide Li{sub 5}Mo{sub 5}O{sub 17} has been carried out by electron microscopy and neutron powder diffraction. The reversible topotactic transformation between the ordered rock salt structure of the former and the ribbon structure of the latter is explained on the following basis: both structures can be described as strips built up as an assembly of infinite ribbons of MoO{sub 6} octahedra that are five octahedra thick, and that differ by slight displacements of the octahedral ribbons. We show that the electrochemical behavior of the Li{sub x}Mo{sub 5}O{sub 17} system is based on two sorts of Li{sup +} sites; those that are located within the strips between the ribbons, and those that are located at the border of the strips. The high rate of Li intercalation in this oxide and its reversibility are discussed in terms of its peculiar structure. Research highlights: {yields} Electron microscopy and neutron powder diffraction structure determination {yields} We have explained the reversible topotactic transformation between an ordered rock salt structure and a ribbon structure {yields} We show that the electrochemical behavior of the Li{sub x}Mo{sub 5}O{sub 17} system is based on two sorts of Li{sup +} sites {yields} The high rate of Li intercalation in this oxide and its reversibility are discussed in terms of its peculiar structure.« less

Magnetoimpedance studies on urine treated Co66Ni7Si7B20 ribbons

NASA Astrophysics Data System (ADS)

Kotagiri, Ganesh; Markandeyulu, G.; Doble, Mukesh; Nandakumar, V.

2015-11-01

Magnetoimpedance (MI) response of Co66Ni7Si7B20 ribbons treated with artificial urine with protein bovine serum albumin (BSA), artificial urine without protein BSA and healthy male urine was studied as a function of time of incubation. The maximum MI [(MI)m] values of the ribbons treated with artificial urine without protein (RTAU) after 3 h, 6 h, 12 h and 24 h of incubation are 30% (at 4 MHz), 15% (at 5 MHz), 14% (at 10 MHz) and 8% (at 13 MHz) respectively. On the other hand, the respective (MI)m values of the ribbons treated with artificial urine with protein (RTAUP) are 33% (at 4 MHz), 25% (at 5 MHz), 20% (at 8 MHz) and 15% (12 MHz). However (MI)m values of the ribbons treated with healthy male urine (RTHMU) after 4 h, 5 h, 10 h and 15 h of incubation are 71% (at 3 MHz), 57% (at 3 MHz), 25% (at 6 MHz) and 25% (at 5 MHz), respectively. The saturation magnetization (Ms) values of RTAU after 3 h, 6 h, 12 h and 24 h of incubation are 71 emu/g, 65 emu/g, 63 emu/g and 60 emu/g respectively whereas, the respective Ms values of RTAUP are 73 emu/g, 69 emu/g, 67 emu/g and 64 emu/g. The Ms values of RTHMU after 4 h, 5 h, 10 h and 15 h of incubation are 96 emu/g, 90 emu/g, 75 emu/g and 75 emu/g respectively. The decrease in Ms and (MI)m values in RTAU and RTAUP compared to as-quenched ribbon is related to the amounts of various elements etched out from the ribbons and increased surface roughness. The Ms and (MI)m values of RTHMU are seen to have increased after 4 h and 5 h of incubation, due to strain relaxation through removal of strain developed during rapid quenching of the ribbons. On the other hand, the Ms and (MI)m values of RTHMU after 10 h and 15 h have decreased due to deterioration of the surface of the ribbons and thus, increase in magnetic (surface) anisotropy. The decrease in (MI)m and MS of RTAU with the time of incubation are more rapid compared to that of RTAUP, probably due to the larger surface anisotropy due to rapid deterioration of the surface of the RTAU than in RTAUP. Asymmetry in MI profiles of RTAU, RTAUP and RTHMU was observed and is attributed to the non-uniform etching of the surface of the ribbons leading to pinning of the domain wall motion.

Center Director Bridges addresses guests at ribbon cutting for the new Checkout & Launch Control

NASA Technical Reports Server (NTRS)

2000-01-01

KSC Director Roy Bridges addresses attendees at a ribbon cutting for the new Checkout and Launch Control System (CLCS) at the Hypergolic Maintenance Facility (HMF). The CLCS was declared operational in a ribbon cutting ceremony earlier. The new control room will be used to process the Orbital Maneuvering System pods and Forward Reaction Control System modules at the HMF. This hardware is removed from Space Shuttle orbiters and routinely taken to the HMF for checkout and servicing.

NASA Associate Administrator for Space Flight Rothenberg addresses guests at ribbon cutting for the

NASA Technical Reports Server (NTRS)

2000-01-01

NASA Associate Administrator for Space Flight Joseph Rothenberg addresses attendees at a ribbon cutting for the new Checkout and Launch Control System (CLCS) at the Hypergolic Maintenance Facility (HMF). The CLCS was declared operational in a ribbon cutting ceremony earlier. The new control room will be used to process the Orbital Maneuvering System pods and Forward Reaction Control System modules at the HMF. This hardware is removed from Space Shuttle orbiters and routinely taken to the HMF for checkout and servicing.

Stennis cuts ribbon on records retention facility

NASA Image and Video Library

2010-08-24

NASA's John C. Stennis Space Center cut the ribbon Aug. 24 on a new, storm-resistant Records Retention Facility that consolidates and protects records storage at the nation's premier rocket engine test facility. This facility will also house history office operations. Participants in the ribbon-cutting included: (l to r) Gay Irby, Center Operations deputy director at Stennis; Linda Cureton, NASA chief information officer; Patrick Scheuermann, Stennis director; Jane Odom, NASA chief archivist; Dinna Cottrell, Stennis chief information officer; and James Cluff, Stennis records manager.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benedek, George; Casparay, Alfred H.

In this project, we are developing a new system for measuring forces within and between nanoscale biological molecules based on mesoscopic springs made of cholesterol helical ribbons. These ribbons self-assemble in a wide variety of complex fluids containing sterol, a mixture of surfactants and water [1] and have spring constants in the range from 0.5 to 500 pN/nm [2-4]. By the end of this project, we have demonstrated that the cholesterol helical ribbons can be used for measuring forces between biological objects and for mapping the strain fields in hydrogels.

Woven ribbon cable for cryogenic instruments

NASA Astrophysics Data System (ADS)

Cunningham, C. R.; Hastings, P. R.; Strachan, J. M. D.

Robust woven ribbon cables are described for connecting sensors at low temperatures to higher temperature systems. Woven cables have several advantages over conventional wiring or flat ribbon cables in cryostats: heat sinking is easier; twisted pairs may be used; and miniature multi-way connectors are easily incorporated. Their use is demonstrated in making connections from 131 bolometers in two arrays mounted in a dilution refrigerator at 100 mK. Thermal and electrical properties are discussed, as are other possible applications in cryogenic instruments.

Silicon web process development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Skutch, M. E.; Driggers, J. M.; Hopkins, R. H.

1981-01-01

The silicon web process takes advantage of natural crystallographic stabilizing forces to grow long, thin single crystal ribbons directly from liquid silicon. The ribbon, or web, is formed by the solidification of a liquid film supported by surface tension between two silicon filaments, called dendrites, which border the edges of the growing strip. The ribbon can be propagated indefinitely by replenishing the liquid silicon as it is transformed to crystal. The dendritic web process has several advantages for achieving low cost, high efficiency solar cells. These advantages are discussed.

Evaluation of a high-visibility seat belt enforcement program on the Blue Ridge Parkway.

DOT National Transportation Integrated Search

2014-11-01

The National Park Service (NPS) conducted a high-visibility enforcement (HVE) seat belt program on a 24-mile section of the Blue Ridge Parkway (BRP) known as the Roanoke Corridor, that carries both park and commuter traffic. Seat belts are required b...

Progress in color reflection holography

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.; Huang, Qiang; Jeong, Tung H.

1998-02-01

The recording technique of Denisyuk color reflection holograms has been simplified by using `white' laser light. The Slavich red-green-blue (RGB) sensitized ultra-high resolution silver halide emulsion was used for the hologram recording. The employed laser wavelengths were 633 nm, 531 nm, and 476 nm, generated by a helium-neon, a mixed argon- krypton ion, and an argon ion laser, respectively. A beam combination mechanism with dichroic filters enabled a simultaneously RGB exposure, which made the color balance and overall exposure energy easy to control as well as simplifying the recording procedure. Various approaches have been investigated in generating color hologram which have sufficiently high diffraction efficiency combined with improved color saturation. A specially designed test object consisting of the 1931 CIE chromaticity diagram, a rainbow ribbon cable, pure yellow dots, and a cloisonne elephant was used for color recording experiments. In addition, the Macbeth Color Checker chart was used. Both colorimetric evaluation and scattering noise measurements were performed using the PR-650 Photo Research SpectraScan SpectraCalorimeter.

Rehabilitation Research at the National Institutes of Health: Moving the Field Forward (Executive Summary)

PubMed Central

Frontera, Walter R.; Bean, Jonathan F.; Damiano, Diane; Ehrlich-Jones, Linda; Fried-Oken, Melanie; Jette, Alan; Jung, Ranu; Lieber, Rick L.; Malec, James F.; Mueller, Michael J.; Ottenbacher, Kenneth J.; Tansey, Keith E.; Thompson, Aiko

2017-01-01

Approximately 53 million Americans live with a disability. For decades, the National Institutes of Health (NIH) has been conducting and supporting research to discover new ways to minimize disability and enhance the quality of life of people with disabilities. After the passage of the Americans With Disabilities Act, NIH established the National Center for Medical Rehabilitation Research, with the goal of developing and implementing a rehabilitation research agenda. Currently, 17 institutes and centers at NIH invest more than $500 million per year in rehabilitation research. Recently, the director of NIH, Francis Collins, appointed a Blue Ribbon Panel to evaluate the status of rehabilitation research across institutes and centers. As a follow-up to the work of that panel, NIH recently organized a conference, “Rehabilitation Research at NIH: Moving the Field Forward.” This report is a summary of the discussions and proposals that will help guide rehabilitation research at NIH in the near future. PMID:28422639

KSC-03PD-2014

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. Hundreds of guests attend a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert 'Hoot' Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, H. W.; Liao, M. C.; Shih, C. W.

2015-05-07

Magnetic properties of melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons made with various wheel speeds have been studied. The ribbons with x = 0–1 are not easy to crystallize and thus display soft magnetic behavior even at wheel speed of 10 m/s. In contrast, the ribbons with x = 1.5–4 at optimized wheel speed exhibit good permanent magnetic properties of B{sub r} = 0.41–0.59 T, {sub i}H{sub c} = 120–400 kA/m, and (BH){sub max} = 10.6–48.1 kJ/m{sup 3}. The optimal magnetic properties of B{sub r} = 0.59 T, {sub i}H{sub c} = 384 kA/m, and (BH){sub max} = 48.1 kJ/m{sup 3} are achieved for Co{sub 80}Hf{sub 14}B{sub 6} ribbons at wheel speed of 30 m/s. X-ray diffraction, thermo-magnetic analysis, and transmission electron microscopy resultsmore » show that good hard magnetic properties of Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons (x = 2–4) are originated from the Co{sub 11}Hf{sub 2} phase well coupled with the Co phase. The change of magnetic properties for Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons spun at various wheel speeds is correlated to microstructure and phase constitution. The strong exchange-coupling effect between magnetic grains for the ribbons with x = 2–3 at wheel speed = 30 m/s leads to remarkable permanent magnetic properties. The presented results suggest that the optimized Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 2–3) ribbons are much suitable than others (x = 0–1.5 and 4) for making rare earth and Pt-free magnets.« less

INFINITY ribbon-cutting

NASA Image and Video Library

2012-04-11

Stennis Space Center welcomes participants during ribbon-cutting activities for the INFINITY at NASA Stennis Space Center facility April 11, 2012. The visitor center and museum is located on Interstate 10, Exit 2, in south Mississippi.

Self-deploying boom

NASA Technical Reports Server (NTRS)

Tumulty, W. T.; Sours, W. P.

1972-01-01

Development and operation of metal ribbon which acts like self deploying boom are described. Metal ribbon is retained on two rollers for storage and extends into nonretractable tubular structure upon release. Illustration of equipment is provided.

1400879

NASA Image and Video Library

2014-08-13

AIDING IN THE OFFICIAL BUILDING 4220 RIBBON-CUTTING ARE, FROM LEFT, JOHN HONEYCUTT, DEPUTY MANAGER OF THE SPACE LAUNCH SYSTEM PROGRAM OFFICE; LT. COL. TOM NELSON, DEPUTY COMMANDER OF THE U.S. ARMY CORPS OF ENGINEERS-MOBILE DISTRICT; U.S. SEN. JEFF SESSIONS OF ALABAMA; MARSHALL CENTER DIRECTOR PATRICK SCHEUERMANN; U.S. REP. MO BROOKS OF ALABAMA'S 5TH DISTRICT; MARSHALL DEPUTY DIRECTOR TERESA VANHOOSER; AND MARSHALL ENGINEER DAVID SKRIDULIS, TEAM LEAD FOR THE FACILITIES MANAGEMENT OFFICE'S CIVIL STRUCTURAL GROUP.

Large Area Silicon Sheet by EFG

NASA Technical Reports Server (NTRS)

Wald, F. V.

1979-01-01

Progress made in the development of EFG ribbon growth is discussed. Specific areas covered include: (1) demonstration of multiple growth for ribbons 5 cm wide in runs of 12 and 20 hours duration; (2) a single cartridge crystal growth station was built expanding observational capacity by virtue of an anamorphic optical-video system which allows close observation of the meniscus over 7.5 cm wide, as well as video taping of the ribbon growth process; (3) growth station no.1 achieved reproducible and reliable growth of 7.5 cm wide ribbon at speeds up to 4 cm/min; (4) introduction of the 'mini cold shoe'; (5) increases in cell efficiency due to interface shaping using the 'displaced die' concept; and (6) clarification of the role of gaseous impurities in cartridge furnaces and stabilization of their destabilizing influence on growth.

From Cylindrical to Stretching Ridges and Wrinkles in Twisted Ribbons

NASA Astrophysics Data System (ADS)

Pham Dinh, Huy; Démery, Vincent; Davidovitch, Benny; Brau, Fabian; Damman, Pascal

2016-09-01

Twisted ribbons under tension exhibit a remarkably rich morphology, from smooth and wrinkled helicoids, to cylindrical or faceted patterns. This complexity emanates from the instability of the natural, helicoidal symmetry of the system, which generates both longitudinal and transverse stresses, thereby leading to buckling of the ribbon. Here, we focus on the tessellation patterns made of triangular facets. Our experimental observations are described within an "asymptotic isometry" approach that brings together geometry and elasticity. The geometry consists of parametrized families of surfaces, isometric to the undeformed ribbon in the singular limit of vanishing thickness and tensile load. The energy, whose minimization selects the favored structure among those families, is governed by the tensile work and bending cost of the pattern. This framework describes the coexistence lines in a morphological phase diagram, and determines the domain of existence of faceted structures.

EBIC/TEM investigations of defects in solar silicon ribbon materials

NASA Technical Reports Server (NTRS)

Ast, D. G.

1981-01-01

Transmission electron microscopy was used to investigate the defect structure of edge defined film growth (EFG) material, web dentritic ribbons (WEB), and ribbon to ribbon recrystallized material (RTR). The most common defects in all these materials are coherent first order twin boundaries. These coherent twins can be very thin, a few atomic layers. Bundles of the twins which contain odd numbers of twins will in optical images appear as a seemingly single first twin boundary. First-order coherent twin boundaries are not electrically active, except at locations where they contain intrinsic (grain boundary) dislocations. These dislocations take up small deviations from the ideal twin relation and play the same role in twin boundaries as conventional and play the some role in twin boundaries as conventional edge and screw dislocations in small angle tilt and twist boundaries.

Large area silicon sheet by EFG. [furnace growth techniques

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a technique for the production of silicon ribbon is discussed. Extensive characterization of the multiple ribbon Furnace 3A main zone temperature profile was performed and the information used to improve uniformity of heating. Irregularities in the main zone heater were associated with growth difficulties at specific cartridge locations, and growth conditions subsequently improved by profiling the main zone heater. Good growth conditions were established in all three cartridge positions. These improvements allowed multiple growth of three 10 cm wide ribbons to be demonstrated for periods of an hour on several occasions. A gas distribution system for the 10 cm cartridge was introduced and demonstrated to lead to improved ambient control during growth. Growth without and with CO2 showed that quality improvement in 10 cm ribbon grown with cold shoes results from ambient manipulation.

Homogeneity and structure of CuZrAlY metallic glass ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fetić, A. Salčinović, E-mail: amra.s@pmf.unsa.ba; Selimović, A.; Hrvat, K.

2016-03-25

Metallic glasses are metastable amorphous structures produced by quenching-rapid cooling technique. Due to very high cooling rates during the production process, it is very difficult to produce homogeneous samples with identical chemical composition. In this paper we will present preliminary results of homogeneity and structure examinations of a CuZrAlY metallic glass ribbon. The ribbon, approximately 1.5 m long and 1 mm wide, was produced using melt spinning technique. Samples from the middle and the end of the ribbon were chosen for further examination. Surface was checked by metallographic and electron scanning microscopy. Chemical composition in different areas of each sample was checkedmore » by energy-dispersive X-ray spectroscopy. Electrical resistivity measurements in the temperature range from 80 K to 280 K were also conducted.« less

Design of a LiNbO(3) ribbon waveguide for efficient difference-frequency generation of terahertz wave in the collinear configuration.

PubMed

Takushima, Y; Shin, S Y; Chung, Y C

2007-10-29

We propose and investigate a ribbon waveguide for difference-frequency generation of terahertz (THz) wave from infrared light sources. The proposed ribbon waveguide is composed of a nonlinear optic crystal and has a thickness less than the wavelength of the THz wave to support the surface-wave mode in the THz region. By utilizing the waveguide dispersion of the surface-wave mode, the phase matching condition between infrared pump, idler and THz waves can be realized in the collinear configuration. Owing to the weak mode confinement of the THz wave, the absorption coefficient can also be reduced. We design the ribbon waveguide which uses LiNbO(3) crystal and discuss the phase-matching condition for DFG of THz wave. Highly efficient THz-wave generation is confirmed by numerical simulations.

Microstructure and mechanical properties of the NiNbZrTiAl amorphous alloys with 10 and 25 at.% Nb content.

PubMed

Czeppe, T; Ochin, P; Sypień, A; Major, L

2010-03-01

The results of investigation of two different Ni-based glasses with compositions Ni(58)Nb(10)Zr(13)Ti(12)Al(7) and Ni(58)Nb(25)Zr(8)Ti(6)Al(3) are presented. The structure of the melt spun ribbons was amorphous. The supercooled liquid range decreased and primary crystallization temperature increased with increasing Nb content while the parameter T(g)/T(m) slightly increased. The crystallization process proceeded in a different way. The ribbon containing 10 at.% Nb showed typical primary crystallization of the 50 nm grains of the NiTi(Nb) cubic phase; the ribbon containing 25 at.% of Nb revealed high thermal stability of the amorphous phase, which crystallized only in a small amount in the range of primary crystallization, preserving large fraction of the amorphous phase even high above the end of the crystallization. The tensile load-displacement curves were also different. In both cases, the ribbons revealed quite a large range of the plastic elongation. The ribbon containing 10% Nb showed stress relaxation and was maximally elongated up to 0.6. The ribbon with 25 at.% Nb revealed a hardening effect and the slightly smaller maximal elongation following it. The microstructure of the deformed specimens showed deformation bands parallel to the tensile axis, microcracks formation along shear bands and river-like pattern at the fracture surfaces. In both cases, high resolution electron microscope did not reveal any crystallization after deformation.

Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material.

PubMed

Gu, X N; Li, X L; Zhou, W R; Cheng, Y; Zheng, Y F

2010-06-01

Rapidly solidified (RS) Mg–3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s(-1), 30 m s(-1) and 45 m s(-1) with the as-cast Mg–3Ca alloy ingot as a raw material. The RS45 Mg–3Ca alloy ribbon showed a much more fine grain size feature (approximately 200–500 nm) in comparison to the coarse grain size (50–100 μm)of the original as-cast Mg–3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg–3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds(1.43 mm yr(-1) for RS15, 0.94 mm yr(-1) for RS30 and 0.36 mm yr(-1) for RS45). The RS Mg–3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg–3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg–3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells,whereas the as-cast Mg–3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg–3Ca alloy ribbons than that of the as-cast Mg–3Ca alloy ingot.

ProFile Vortex and Vortex Blue Nickel-Titanium Rotary Instruments after Clinical Use.

PubMed

Shen, Ya; Zhou, Huimin; Coil, Jeffrey M; Aljazaeri, Bassim; Buttar, Rene; Wang, Zhejun; Zheng, Yu-feng; Haapasalo, Markus

2015-06-01

The aim of this study was to analyze the incidence and mode of ProFile Vortex and Vortex Blue instrument defects after clinical use in a graduate endodontic program and to examine the impact of clinical use on the instruments' metallurgical properties. A total of 330 ProFile Vortex and 1136 Vortex Blue instruments from the graduate program were collected after each had been used in 3 teeth. The incidence and type of instrument defects were analyzed. The lateral surfaces and fracture surfaces of the fractured files were examined by using scanning electron microscopy. Unused and used instruments were examined by full and partial differential scanning calorimetry. No fractures were observed in the 330 ProFile Vortex instruments, whereas 20 (6.1%) revealed bent or blunt defects. Only 2 of the 1136 Vortex Blue files fractured during clinical use. The cause of fracture was shear stress. The fractures occurred at the tip end of the spirals. Only 1.8% (21 of 1136) of the Vortex Blue files had blunt tips. Austenite-finish temperatures were very similar for unused and used ProFile Vortex files and were all greater than 50°C. The austenite-finish temperatures of used and unused Vortex Blue files (38.5°C) were lower than those in ProFile Vortex instruments (P < .001). However, the transformation behavior of Vortex Blue files had an obvious 2-stage transformation, martensite-to-R phase and R-to-austenite phase. The trends of differential scanning calorimetry plots of unused Vortex Blue instruments and clinically used instruments were very similar. The risk of ProFile Vortex and Vortex Blue instrument fracture is very low when instruments are discarded after clinical use in the graduate endodontic program. The Vortex Blue files have metallurgical behavior different from ProFile Vortex instruments. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evolution of flare ribbons, electric currents, and quasi-separatrix layers during an X-class flare

NASA Astrophysics Data System (ADS)

Janvier, M.; Savcheva, A.; Pariat, E.; Tassev, S.; Millholland, S.; Bommier, V.; McCauley, P.; McKillop, S.; Dougan, F.

2016-07-01

Context. The standard model for eruptive flares has been extended to three dimensions (3D) in the past few years. This model predicts typical J-shaped photospheric footprints of the coronal current layer, forming at similar locations as the quasi-separatrix layers (QSLs). Such a morphology is also found for flare ribbons observed in the extreme ultraviolet (EUV) band, and in nonlinear force-free field (NLFFF) magnetic field extrapolations and models. Aims: We study the evolution of the photospheric traces of the current density and flare ribbons, both obtained with the Solar Dynamics Observatory instruments. We aim to compare their morphology and their time evolution, before and during the flare, with the topological features found in a NLFFF model. Methods: We investigated the photospheric current evolution during the 06 September 2011 X-class flare (SOL2011-09-06T22:20) occurring in NOAA AR 11283 from observational data of the magnetic field obtained with the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory. We compared this evolution with that of the flare ribbons observed in the EUV filters of the Atmospheric Imager Assembly. We also compared the observed electric current density and the flare ribbon morphology with that of the QSLs computed from the flux rope insertion method-NLFFF model. Results: The NLFFF model shows the presence of a fan-spine configuration of overlying field lines, due to the presence of a parasitic polarity, embedding an elongated flux rope that appears in the observations as two parts of a filament. The QSL signatures of the fan configuration appear as a circular flare ribbon that encircles the J-shaped ribbons related to the filament ejection. The QSLs, evolved via a magnetofrictional method, also show similar morphology and evolution as both the current ribbons and the EUV flare ribbons obtained several times during the flare. Conclusions: For the first time, we propose a combined analysis of the photospheric traces of an eruptive flare, in a complex topology, with direct measurements of electric currents and QSLs from observational data and a magnetic field model. The results, obtained by two different and independent approaches 1) confirm previous results of current increase during the impulsive phase of the flare and 2) show how NLFFF models can capture the essential physical signatures of flares even in a complex magnetic field topology. A movie associated to Fig. 1 is available in electronic form at http://www.aanda.org

Instrumented roll technology for the design space development of roller compaction process.

PubMed

Nesarikar, Vishwas V; Vatsaraj, Nipa; Patel, Chandrakant; Early, William; Pandey, Preetanshu; Sprockel, Omar; Gao, Zhihui; Jerzewski, Robert; Miller, Ronald; Levin, Michael

2012-04-15

Instrumented roll technology on Alexanderwerk WP120 roller compactor was developed and utilized successfully for the measurement of normal stress on ribbon during the process. The effects of process parameters such as roll speed (4-12 rpm), feed screw speed (19-53 rpm), and hydraulic roll pressure (40-70 bar) on normal stress and ribbon density were studied using placebo and active pre-blends. The placebo blend consisted of 1:1 ratio of microcrystalline cellulose PH102 and anhydrous lactose with sodium croscarmellose, colloidal silicon dioxide, and magnesium stearate. The active pre-blends were prepared using various combinations of one active ingredient (3-17%, w/w) and lubricant (0.1-0.9%, w/w) levels with remaining excipients same as placebo. Three force transducers (load cells) were installed linearly along the width of the roll, equidistant from each other with one transducer located in the center. Normal stress values recorded by side sensors and were lower than normal stress values recorded by middle sensor and showed greater variability than middle sensor. Normal stress was found to be directly proportional to hydraulic pressure and inversely to screw to roll speed ratio. For active pre-blends, normal stress was also a function of compressibility. For placebo pre-blends, ribbon density increased as normal stress increased. For active pre-blends, in addition to normal stress, ribbon density was also a function of gap. Models developed using placebo were found to predict ribbon densities of active blends with good accuracy and the prediction error decreased as the drug concentration of active blend decreased. Effective angle of internal friction and compressibility properties of active pre blend may be used as key indicators for predicting ribbon densities of active blend using placebo ribbon density model. Feasibility of on-line prediction of ribbon density during roller compaction was demonstrated using porosity-pressure data of pre-blend and normal stress measurements. Effect of vacuum to de-aerate pre blend prior to entering the nip zone was studied. Varying levels of vacuum for de-aeration of placebo pre blend did not affect the normal stress values. However, turning off vacuum completely caused an increase in normal stress with subsequent decrease in gap. Use of instrumented roll demonstrated potential to reduce the number of DOE runs by enhancing fundamental understanding of relationship between normal stress on ribbon and process parameters. Copyright © 2012 Elsevier B.V. All rights reserved.

Studying the Water Cycle in an Environmental Context: The "Blue Planet" Program.

ERIC Educational Resources Information Center

Ben-zvi-assaraf, Orit; Orion, Nir

The Blue Planet program aims to develop an understanding of and insight into the environment among students by introducing environmental problems such as pollution. This paper presents a study investigating junior high school students' previous knowledge and understanding of environmental issues and perceptions on the nature of the water cycle.…

The identification of a sensitizing component used in the manufacturing of an ink ribbon.

PubMed

Anderson, Stacey E; Tapp, Loren; Durgam, Srinivas; Meade, B Jean; Jackson, Laurel G; Cohen, David E

2012-01-01

Skin diseases including dermatitis constitute ≈ 30% of all occupational illnesses, with a high incidence in the printing industry. An outbreak of contact dermatitis among employees at an ink ribbon manufacturing plant was investigated by scientists from the National Institute for Occupational Safety and Health (NIOSH). Employees in the process areas of the plant were exposed to numerous chemicals and many had experienced skin rashes, especially after the introduction of a new ink ribbon product. To identify the causative agent(s) of the occupational dermatitis, the murine local lymph node assay (LLNA) was used to identify the potential of the chemicals used in the manufacture of the ink ribbon to induce allergic contact dermatitis. Follow-up patch testing with the suspected allergens was conducted on exposed employees. Polyvinyl butyral, a chemical component used in the manufacture of the ink ribbon in question and other products, tested positive in the LLNA, with an EC3 of 3.6%, which identifies it as a potential sensitizer; however, no employees tested positive to this chemical during skin patch testing. This finding has implications beyond those described in this report because of occupational exposure to polyvinyl butyral outside of the printing industry.

Ultra-broad polypyrrole (PPy) nano-ribbons seeded by racemic surfactants aggregates and their high-performance electromagnetic radiation elimination.

PubMed

Jiao, Yingzhi; Wu, Fan; Zhang, Kun; Sun, Mengxiao; Xie, Aming; Dong, Wei

2017-08-04

Ribbon-like nano-structures possess high aspect ratios, and thus have great potential in the development of high-performance microwave absorption (MA) materials that can effectively eliminate adverse electromagnetic radiation. However, these nano-structures have been scarcely constructed in the field of MA, because of the lack of efficient synthetic routes. Herein, we developed an efficient method to successfully construct polypyrrole (PPy) nano-ribbons using the self-assembly aggregates of a racemic surfactant as the seeds. The frequency range with a reflection loss value of lower than -10 dB reached 7.68 GHz in the frequency range of 10.32-18.00 GHz, and surpassed all the currently reported PPy nano-structures, as well as most other MA nano-materials. Through changing the amount of surfactant, both the nano-structures and MA performance can be effectively regulated. Furthermore, the reason behind the high-performance MA of PPy nano-ribbons has been deeply explored. It opens up the opportunity for the application of conducting polymer nano-ribbons as a lightweight and tunable high-performance MA material, especially in applications of special aircraft and flexible electronics.

The identification of a sensitizing component used in the manufacturing of an ink ribbon

PubMed Central

Anderson, Stacey E.; Tapp, Loren; Durgam, Srinivas; Meade, B. Jean; Jackson, Laurel G.; Cohen, David E.

2015-01-01

Skin diseases including dermatitis constitute ≈ 30% of all occupational illnesses, with a high incidence in the printing industry. An outbreak of contact dermatitis among employees at an ink ribbon manufacturing plant was investigated by scientists from the National Institute for Occupational Safety and Health (NIOSH). Employees in the process areas of the plant were exposed to numerous chemicals and many had experienced skin rashes, especially after the introduction of a new ink ribbon product. To identify the causative agent(s) of the occupational dermatitis, the murine local lymph node assay (LLNA) was used to identify the potential of the chemicals used in the manufacture of the ink ribbon to induce allergic contact dermatitis. Follow-up patch testing with the suspected allergens was conducted on exposed employees. Polyvinyl butyral, a chemical component used in the manufacture of the ink ribbon in question and other products, tested positive in the LLNA, with an EC3 of 3.6%, which identifies it as a potential sensitizer; however, no employees tested positive to this chemical during skin patch testing. This finding has implications beyond those described in this report because of occupational exposure to polyvinyl butyral outside of the printing industry. PMID:22375946

Edge-Dependent Electronic and Magnetic Characteristics of Freestanding β 12-Borophene Nanoribbons

NASA Astrophysics Data System (ADS)

Izadi Vishkayi, Sahar; Bagheri Tagani, Meysam

2018-03-01

This work presents an investigation of nanoribbons cut from β 12-borophene sheets by applying the density functional theory. In particular, the electronic and magnetic properties of borophene nanoribbons (BNR) are studied. It is found that all the ribbons considered in this work behave as metals, which is in good agreement with the recent experimental results. β 12-BNR has significant diversity due to the existence of five boron atoms in a unit cell of the sheet. The magnetic properties of the ribbons are strongly dependent on the cutting direction and edge profile. It is interesting that a ribbon with a specific width can behave as a normal or a ferromagnetic metal with magnetization at just one edge or two edges. Spin anisotropy is observed in some ribbons, and the magnetic moment is not found to be the same in both edges in an antiferromagnetic configuration. This effect stems from the edge asymmetry of the ribbons and results in the breaking of spin degeneracy in the band structure. Our findings show that β 12 BNRs are potential candidates for next-generation spintronic devices. [Figure not available: see fulltext.

Fish Marketing of Ribbon Fish (Trichiurus sp.) in Nusantara Fishing Port (NFP)at Palabuhanratu, West Java

NASA Astrophysics Data System (ADS)

Bambang, Azis Nur

2018-02-01

The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp.), including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP), Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters). The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman's share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman's share.

Stretchable interconnections for flexible electronic systems.

PubMed

Jianhui, Lin; Bing, Yan; Xiaoming, Wu; Tianling, Ren; Litian, Liu

2009-01-01

Sensors, actuators and integrated circuits (IC) can be encapsulated together on an elastic substrate, which makes a flexible electronic system. In this system, electrical interconnections that can sustain large and reversible stretching are in great need. This paper is devoted to the fabrication of highly stretchable metal interconnections. Transfer printing technology is utilized, which mainly involves the transfer of 100-nm-thick gold ribbons from silicon wafers to pre-stretched elastic substrates. After the elastic substrates relax from the pre-strain, the gold ribbons buckle and form wavy geometries. These wavy geometries change in shapes to accommodate the applied strain and can be reversely stretched without cracks or fractures occurring, which will greatly raise the stretchability of the gold ribbons. As an application example, some of these wavy ribbons can accommodate high levels of stretching (up to 100%) and bending (with curvature radius down to 1.20 mm). Moreover, the efficiency and reliability of the transfer, especially for slender ribbons, have been increased due to the improvement of the technology. All the characteristics above will permit making stretchable gold conductors as interconnections for flexible electronic systems such as implantable medical systems and smart clothes.

Ultra-broad polypyrrole (PPy) nano-ribbons seeded by racemic surfactants aggregates and their high-performance electromagnetic radiation elimination

NASA Astrophysics Data System (ADS)

Jiao, Yingzhi; Wu, Fan; Zhang, Kun; Sun, Mengxiao; Xie, Aming; Dong, Wei

2017-08-01

Ribbon-like nano-structures possess high aspect ratios, and thus have great potential in the development of high-performance microwave absorption (MA) materials that can effectively eliminate adverse electromagnetic radiation. However, these nano-structures have been scarcely constructed in the field of MA, because of the lack of efficient synthetic routes. Herein, we developed an efficient method to successfully construct polypyrrole (PPy) nano-ribbons using the self-assembly aggregates of a racemic surfactant as the seeds. The frequency range with a reflection loss value of lower than -10 dB reached 7.68 GHz in the frequency range of 10.32-18.00 GHz, and surpassed all the currently reported PPy nano-structures, as well as most other MA nano-materials. Through changing the amount of surfactant, both the nano-structures and MA performance can be effectively regulated. Furthermore, the reason behind the high-performance MA of PPy nano-ribbons has been deeply explored. It opens up the opportunity for the application of conducting polymer nano-ribbons as a lightweight and tunable high-performance MA material, especially in applications of special aircraft and flexible electronics.

Magnetic properties and macroscopic heterogeneity of FeCoNbB Hitperms

NASA Astrophysics Data System (ADS)

Butvin, Pavol; Butvinová, Beata; Sitek, Jozef; Degmová, Jarmila; Vlasák, Gabriel; Švec, Peter; Janičkovič, Dušan

Nanocrystalline ribbons of Fe 81-xCo xNb 7B 12 (where x ranges from 0 to 40.5 at%) Hitperm alloys have been investigated as to their basic magnetic properties and the influence of the macroscopic heterogeneity. Different crystalline share at surfaces compared with the volume average is observed by conversion electron Mössbauer spectroscopy (CEMS) and Mössbauer spectroscopy (MS), respectively. This marks the presence of macroscopic heterogeneity in these Hitperms. The heterogeneity is generally more significant in Ar-annealed samples than in the vacuum-annealed ones. The characteristic slant hysteresis loops (hard-ribbon-axis) are seen as a rule with few exceptions. An inspection of hysteresis loop response of resin potted samples shows that the surfaces bi-axially squeeze the ribbon interior in heterogeneous Hitperms when the ribbons cool down after annealing. Certain compositions show macroscopic viscous flow prior to crystallization so the heterogeneity gets another chance to induce anisotropy during annealing. The induction attains 1.5 T but saturates poorly due to the heterogeneity and the ensuing anisotropy. Moreover the heterogeneity appears to hamper the crystallization within the ribbon interior. Unlike Finemets, the density of these Hitperms show no pronounced trend with annealing.

Displaced capillary dies

DOEpatents

Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas

1982-01-01

An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

Displaced capillary dies

DOEpatents

Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas

1984-01-01

An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

KENNEDY SPACE CENTER, FLA. - Center Director and former astronaut Roy D. Bridges, Jr., (holding scissors) cuts the ribbon at a ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. Invited guests and dignitaries look on, such as former astronauts Edgar D. Mitchell on Bridges' left and James Lovell (hand up) and Buzz Aldrin on his right. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

NASA Image and Video Library

2003-06-20

KENNEDY SPACE CENTER, FLA. - Center Director and former astronaut Roy D. Bridges, Jr., (holding scissors) cuts the ribbon at a ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. Invited guests and dignitaries look on, such as former astronauts Edgar D. Mitchell on Bridges' left and James Lovell (hand up) and Buzz Aldrin on his right. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.

Systems and Methods for Fabricating Structures Including Metallic Glass-Based Materials Using Ultrasonic Welding

NASA Technical Reports Server (NTRS)

Hofmann, Douglas C. (Inventor); Roberts, Scott N. (Inventor)

2017-01-01

Systems and methods in accordance with embodiments of the invention fabricate objects including metallic glass-based materials using ultrasonic welding. In one embodiment, a method of fabricating an object that includes a metallic glass-based material includes: ultrasonically welding at least one ribbon to a surface; where at least one ribbon that is ultrasonically welded to a surface has a thickness of less than approximately 150.mu.m; and where at least one ribbon that is ultrasonically welded to a surface includes a metallic glass-based material.

Cryogenic ribbon-cutting

NASA Image and Video Library

2011-03-30

NASA cut the ribbon on a new cryogenics control center at John C. Stennis Space Center on March 30. The new facility is part of a project to strengthen Stennis facilities to withstand the impacts of future storms like hurricane Katrina in 2005. Participants in the ribbon-cutting included (l to r): Jason Zuckerman, director of project management for The McDonnel Group; Keith Brock, director of the NASA Project Directorate at Stennis; Stennis Deputy Director Rick Gilbrech; Steve Jackson of Jacobs Technology; and Troy Frisbie, Cryo Control Center Construction project manager for NASA Center Operations at Stennis.

Large area silicon sheet by EFG

NASA Technical Reports Server (NTRS)

1981-01-01

A multiple growth run with three 10 cm cartridges was carried out with the best throughput rates and time percentage of simultaneous three ribbon growth achieved to date in this system. Growth speeds were between 3.2 and 3.6 cm/minute on all three cartridges and simultaneous full width growth of three ribbons was achieved 47 percent of the time over the eight hour duration of the experiment. Improvements in instrumentation and in the main zone temperature uniformity were two factors that have led to more reproducible growth conditions in the multiple ribbon furnace.

Study of Defect Behaviour in Ga2O3 Nanowires and Nano-Ribbons under Reducing Gas Annealing Conditions: Applications to Sensing

DTIC Science & Technology

2007-01-01

Study of defect behaviour in Ga2O3 nanowires and nano-ribbons under reducing gas annealing conditions: applications to...estd.nrl.navy.mil E-mail: Carlos@bloch.nrl.navy.mil E-mail: Glaser@ bloch.nrl.navy.mil *Corresponding author Abstract: The growth of monoclinic Ga2O3 ...an Au catalyst, while single crystal nano-ribbons and nano-sheets require no metal catalyst for growth. Since bulk Ga2O3 is a promising material

Low-loss silicide/silicon plasmonic ribbon waveguides for mid- and far-infrared applications.

PubMed

Cho, Sang-Yeon; Soref, Richard A

2009-06-15

We report low-loss silicide/silicon plasmonic ribbon waveguides for mid- and far-IR applications. The composite modes in silicide ribbon waveguides offer a low-loss and highly confined mode profile, giving excellent plasmon waveguiding for long-wavelength applications. The calculated propagation loss of the composite long-range surface-plasmon polariton mode at a wavelength of 100 microm is 2.18 dB/cm with a mode height of less than 30 microm. The results presented provide important design guidelines for silicide/Si plasmon waveguides.