WorldWideScience

Sample records for hole oceanographic institution

  1. Archive of Geosample Data and Information from the Woods Hole Oceanographic Institution (WHOI) Seafloor Samples Laboratory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Woods Hole Oceanographic Institution (WHOI) Seafloor Samples Laboratory is a partner in the Index to Marine and Lacustrine Geological Samples (IMLGS) database,...

  2. Woods Hole Oceanographic Institute's Martha's Vineyard Coastal Observatory component locations (ESRI POINT SHAPEFILE, MVCO)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Woods Hole Oceanographic Institution has built the Martha's Vineyard Coastal Observatory (MVCO) near South Beach in Edgartown, Massachusetts. The project was...

  3. Laser safety program at Woods Hole Oceanographic Institution.

    Science.gov (United States)

    Reif, Ronald H; Fraser, Leanora A; Liffers, Mark L

    2013-02-01

    Implementing a laser safety program at the Woods Hole Oceanographic Institution (WHOI) presents many challenges and opportunities for improving safety performance. Getting all laser users to take ownership of safety and comply with all laser safety requirements are key ingredients of a successful laser safety program. WHOI's laser safety program includes the following elements: registration of high power lasers, hazard analysis of laser facilities, proper design of laser facilities, selection of hazard controls, laser safe operating procedures, laser safety training for all laser users, and routine inspections of laser facilities. Laser owners are required to sign the high power laser registration form and agree to comply with all applicable requirements. All laser users are required to sign the laser safe operating procedure that applies to their facility and follow the requirements. Laser users are included in the development of laser safe operating procedures, design of their facilities, review of hazard analysis calculations for their lasers, and in the selection of hazard controls. Laser safety training for new laser users includes a tour of established laser facilities, review of laser safe operating procedure, and a review of basic laser safety information. By engaging the laser users in all elements of the laser safety program, ownership of laser safety at the user level is more easily established and compliance with safety requirements is significantly improved. New laser owners and users are mentored by experienced laser users and are given an opportunity to observe the implementation of laser safety procedures at established laser facilities before operating their own high power lasers. Increased compliance with safety requirements has been demonstrated with fewer non-compliance items noted during annual laser safety inspections, more participation in initial and annual refresher training, and more requests from higher power laser users for assistance

  4. Geophysical Fluid Dynamics Laboratory Open Days at the Woods Hole Oceanographic Institution

    Science.gov (United States)

    Hyatt, Jason; Cenedese, Claudia; Jensen, Anders

    2015-11-01

    This event was hosted for one week for two consecutive years in 2013 and 2014. It targeted postdocs, graduate students, K-12 students and local community participation. The Geophysical Fluid Dynamics Laboratory at the Woods Hole Oceanographic Institution hosted 10 hands-on demonstrations and displays, with something for all ages, to share the excitement of fluid mechanics and oceanography. The demonstrations/experiments spanned as many fluid mechanics problems as possible in all fields of oceanography and gave insight into using fluids laboratory experiments as a research tool. The chosen experiments were `simple' yet exciting for a 6 year old child, a high school student, a graduate student, and a postdoctoral fellow from different disciplines within oceanography. The laboratory is a perfect environment in which to create excitement and stimulate curiosity. Even what we consider `simple' experiments can fascinate and generate interesting questions from both a 6 year old child and a physics professor. How does an avalanche happen? How does a bath tub vortex form? What happens to waves when they break? How does a hurricane move? Hands-on activities in the fluid dynamics laboratory helped students of all ages in answering these and other intriguing questions. The laboratory experiments/demonstrations were accompanied by `live' videos to assist in the interpretation of the demonstrations. Posters illustrated the oceanographic/scientific applicability and the location on Earth where the dynamics in the experiments occur. Support was given by the WHOI Doherty Chair in Education.

  5. Ocean observation data from Woods Hole Oceanographic Institution ships Oceanus, Knorr, and Atlantis, in world-wide oceans from 1993-06-26 to 2011-08-05

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are part of a collection of ocean observation data from Woods Hole Oceanographic Institution ships OCEANUS (call sign WXAQ; built 1975.00; IMO 7603617),...

  6. Physical trajectory profile data from glider sp065 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-10-01 to 2016-01-07 (NCEI Accession 0145716)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  7. Physical trajectory profile data from glider sp010 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2017-07-07 to 2017-09-12 (NCEI Accession 0166618)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution. (This deployment supported by NOAA.) The National Centers for Environmental Information (NCEI)...

  8. Physical trajectory profile data from glider sp066 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-12-17 to 2016-04-06 (NCEI Accession 0153789)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  9. Physical trajectory profile data from glider sp066 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2016-08-18 to 2016-09-28 (NCEI Accession 0156697)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  10. Physical trajectory profile data from glider sp010 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-04-09 to 2015-06-25 (NCEI Accession 0139261)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  11. Physical trajectory profile data from glider sp055 deployed by Woods Hole Oceanographic Institution in the East Coast - US/Canada from 2015-07-16 to 2015-10-16 (NCEI Accession 0145714)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spray glider profile data from Woods Hole Oceanographic Institution (supported by NOAA). The National Centers for Environmental Information (NCEI) received the data...

  12. RADIATION MEASUREMENTS BY BROOKHAVEN NATIONAL LABORATORY DURING THE WOODS HOLE OCEANOGRAPHIC INSTITUTION INTERCOMPARISON STUDY, MAY-JUNE 2000.

    Energy Technology Data Exchange (ETDEWEB)

    REYNOLDS, R.M.; BARTHOLOMEW, M.J.; MILLER, M.A.; SMITH, S.; EDWARDS, R.

    2000-12-01

    The WHOI buoy radiometer intercomparison took place during May and June, 2000 at the WHOI facility. The WHOI IMET, JAMSTEC Triton, and NOAA TAO buoy systems were operated from a beach site and the Brookhaven National Laboratory set up two Portable Radiation Package systems (P01 and P02) alongside the WHOI instrumentation on the roof of the Clark Building, about 300 m away. The BNL instruments were named ''P01'' and ''P02'' and were identical. Buoy instruments were all leveled to {+-}1{degree} to horizontal. The purpose of the project was to compare the buoy systems with precision measurements so that any differences in data collection or processing would be evaluated. BNL was pleased to participate so the PRP system could be evaluated as a calibration tool. The Portable Radiation Package is an integral component of the BNL Shipboard Oceanographic and Atmospheric Radiation (SOAR) system. It is designed to make accurate downwelling radiation measurements, including the three solar irradiance components (direct normal, diffuse and global) at six narrowband channels, aerosol optical depth measurements, and broadband longwave and shortwave irradiance measurements.

  13. The Environmental Impacts of Boating; Proceedings of a Workshop held at Woods Hole Oceanographic Institution, Woods Hole MA USA, December 7 to 9, 1994.

    Science.gov (United States)

    1998-03-01

    presentations are available on diskette from Michael Moore, MS 33, WHOI, Woods Hole, MA 02543. The editors also thank Bruno Broughton of Ruddington...subject of a federal court case in 1981. A marine contractor was replacing one of the overseas highway bridges in the lower Keys. The marine 35...episodes. Allowing for slower resettlement and even longer phosphorus suspension times (Yousef 1980), these episodes could have cumulative effects

  14. A review of the Oceanographic Research Institute's Cooperative ...

    African Journals Online (AJOL)

    The Oceanographic Research Institute's (ORI) Cooperative Fish Tagging Project was initiated in 1984 and is one of the most enduring and successful environmental projects of its kind in South Africa. By the end of 2011, 5 130 anglers had joined the project, of whom 3 457 had tagged one or more fish. In the project's ...

  15. In situ, meteorological, navigational, physical and profile data collected by University of Hawaii at Manoa and Woods Hole Oceanographic Institution at OceanSITES site WHOTS from 2004-08-12 to 2016-09-02 (NCEI Accession 0131449)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In situ, meteorological, navigational, physical and profile oceanographic data were collected, including AIR TEMPERATURE, BAROMETRIC PRESSURE, CONDUCTIVITY, CURRENT...

  16. In situ, meteorological, navigational, physical and profile data collected by Woods Hole Oceanographic Institution at OceanSITES site Stratus from 2000-10-07 to 2016-10-06 (NCEI Accession 0131163)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In situ, meteorological, navigational, physical and profile oceanographic data were collected, including AIR TEMPERATURE, BAROMETRIC PRESSURE, CONDUCTIVITY, CURRENT...

  17. In situ, meteorological, navigational, physical and profile data collected by Woods Hole Oceanographic Institution at OceanSITES site NTAS from 2001-03-30 to 2016-10-06 (NCEI Accession 0131154)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In situ, meteorological, navigational, physical and profile oceanographic data were collected, including AIR TEMPERATURE, BAROMETRIC PRESSURE, CONDUCTIVITY, CURRENT...

  18. NATO Advanced Study Institute on Advanced Physical Oceanographic Numerical Modelling

    CERN Document Server

    1986-01-01

    This book is a direct result of the NATO Advanced Study Institute held in Banyuls-sur-mer, France, June 1985. The Institute had the same title as this book. It was held at Laboratoire Arago. Eighty lecturers and students from almost all NATO countries attended. The purpose was to review the state of the art of physical oceanographic numerical modelling including the parameterization of physical processes. This book represents a cross-section of the lectures presented at the ASI. It covers elementary mathematical aspects through large scale practical aspects of ocean circulation calculations. It does not encompass every facet of the science of oceanographic modelling. We have, however, captured most of the essence of mesoscale and large-scale ocean modelling for blue water and shallow seas. There have been considerable advances in modelling coastal circulation which are not included. The methods section does not include important material on phase and group velocity errors, selection of grid structures, advanc...

  19. In situ, navigational, physical and profile data collected by Woods Hole Oceanographic Institution at OceanSITES site LINE-W from 2001-10-05 to 2008-09-23 (NCEI Accession 0130038)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In situ, navigational, physical and profile oceanographic data were collected, including CURRENT SPEED - EAST/WEST COMPONENT (U), CURRENT SPEED - NORTH/SOUTH...

  20. Collaborative Oceanographic Research Opportunities with Schmidt Ocean Institute

    Science.gov (United States)

    Zykov, V.

    2014-12-01

    Schmidt Ocean Institute (http://www.schmidtocean.org/) was founded by Dr. Eric Schmidt and Wendy Schmidt in 2009 to support frontier oceanographic research and exploration to expand the understanding of the world's oceans through technological advancement, intelligent, data-rich observation and analysis, and open sharing of information. Schmidt Ocean Institute operates a state-of-the-art globally capable research vessel Falkor (http://www.schmidtocean.org/story/show/47). After two years of scientific operations in the Atlantic Ocean, Gulf of Mexico, Caribbean, Eastern and Central Pacific, R/V Falkor is now preparing to support research in the Western Pacific and Eastern Indian Oceans in 2015 and 2016. As part of the long term research program development for Schmidt Ocean Institute, we aim to identify initiatives and projects that demonstrate strong alignment with our strategic interests. We focus on scientific opportunities that highlight effective use of innovative technologies to better understand the oceans, such as, for example, research enabled with remotely operated and autonomous vehicles, acoustics, in-situ sensing, telepresence, etc. Our technology-first approach to ocean science gave rise to infrastructure development initiatives, such as the development of a new full ocean depth Hybrid Remotely Operated Vehicle, new 6000m scientific Autonomous Underwater Vehicle, live HD video streaming from the ship to YouTube, shipboard high performance supercomputing, etc. We also support projects focusing on oceanographic technology research and development onboard R/V Falkor. We provide our collaborators with access to all of R/V Falkor's facilities and instrumentation in exchange for a commitment to make the resulting scientific data openly available to the international oceanographic community. This presentation aims to expand awareness about the interests and capabilities of Schmidt Ocean Institute and R/V Falkor among our scientific audiences and further

  1. Oceanographic Research of Marine Hydrophysical Institute in the Southern Ocean

    Directory of Open Access Journals (Sweden)

    Yu.V. Artamonov

    2016-12-01

    Full Text Available Basic stages of the oceanographic research carried out by Marine Hydrophysical Institute in the Southern ocean are considered. Each stage of the studies is illustrated by the schemes of expeditionary work; the most important results are presented. The oceanographic studies of Marine Hydrophysical Institute in the Southern ocean are shown to be developed in two basic directions: marine expeditionary research and analysis of the archival hydrometeorological data. Based on the results of expeditionary studies, the mechanisms of formation and variability of the water structure and circulation in the Antarctic coastal regions are described. Anomalies of hydrometeorological fields occurring along the route to Antarctica are assessed due to the measurements from the passing vessels. The archival hydrological and satellite data constitute a foundation for revealing the features of seasonal and interannual variability of the ocean surface temperature, fronts and sea ice in Antarctica. The effect of El Niño events on the interannual variation of the characteristics of Scotia Sea Front is revealed. It is shown that the formation of warm water positive anomaly areas in the tropical Pacific is caused by El Niño events. It’s accompanied by an appreciable displacement of the front to the south, by the weakening of its intensity and the decrease of temperature on the front axes. It is shown that maximum seasonal variation of the ice concentration is observed in the Weddell and Lazarev Seas. The ice in the Weddell, Amundsen and Bellingshausen Sea are shown to be exposed to the highest interannual variability.

  2. Summer Study Program in Geophysical Fluid Dynamics, Woods Hole Oceanographic Institution: Chaos.

    Science.gov (United States)

    1985-11-01

    Chaotic Boundaries In the Disc Dynamo Kirk Brattkus ....... .. ....................... 202 Convection with Mixed Up Boundary Conditions William Morrell...D p s t s (2). -. I.-, .-. . . . |* 4 + % . . .... . . .I . .’.. • . 01 P Figure 2: A bicycle seat -the beginnings of a strange attractor. The...instability (e.g. Childress and Spiegel, 1980) with the Lorenz equations for the convective dynamo process that generates the flux pumped into the layer. An

  3. Summer Study Program in Geophysical Fluid Dynamics, The Woods Hole Oceanographic Institution, Dynamic Differentiation.

    Science.gov (United States)

    1984-01-01

    wavelength) modes does not occur through an Onsoger- Kolmogoroff cascade. This is shown in two different ways. The time fluctuations of the space power...far-field. In solidifying, the dendrites reject -.- - heavy, compositionally enriched fluid which descends into the spaces between _ the dendrites...where the temperature is lower. Further crystallization can take place in these spaces , which also releases heavy fluid. The overall process suggests

  4. Final Report on Contract N00014-89-D-0255 (Woods Hole Oceanographic Institution)

    Science.gov (United States)

    1991-06-30

    operation were: (1) to demonstrate new tools and techniques for application to naval operations in tactical underwater terrains; (2) to conduct engineering...field tests of new capabilities for multiscale, multisensor seafloor characterization; and ;A! o .,. (3) to complete a limited scientific field program...to the finest level using man-in-the loop systems (optical imaging and seafloor sampling with DSV Turtle and the Jason- MEDEA system). Information

  5. Coastal Research Center Woods Hole Oceanographic Institution Report for the Period March 1986-July 1988

    Science.gov (United States)

    1989-03-01

    research programs. Dr. Donald Riloads and Dr. Larry Boyer of Yale Univesity donated the racetrack flume to the Coastal Research Center, and by doing so...interest across all departments in the coastal zone. We hope to continue funding to increase these educational opportunities which serve to solidify

  6. Communicating Ocean Sciences to Informal Audiences (COSIA): Universities, Oceanographic Institutions, Science Centers and Aquariums Working Together to Improve Ocean Education and Public Outreach

    Science.gov (United States)

    Glenn, S.; McDonnell, J.; Halversen, C.; Zimmerman, T.; Ingram, L.

    2007-12-01

    and inquiry-based ocean sciences activities for children and families visiting informal institutions. The following COSIA partners have taught the course: Hampton University - Virginia Aquarium; Oregon State University - Hatfield Marine Science Visitor's Center; Rutgers University - Liberty Science Center; University of California, Berkeley - Lawrence Hall of Science; University of Southern California - Aquarium of the Pacific; and Scripps Institution of Oceanography - Birch Aquarium. Communicating Ocean Sciences has also been taught at Stanford, Woods Hole Oceanographic Institute, University of Oregon (GK-12 program), University of Washington, and others. Data from surveys of students demonstrates improvement in their understanding of how people learn and how to effectively communicate. Providing college students with a background in current learning theory, and applying that theory through practical science communication experiences, will empower future generations of scientists to meet the communication challenges they will encounter in their careers.

  7. The New Oceanographic Research Institution: Scripps in the ``Broader Impact'' Era

    Science.gov (United States)

    Kennel, C. F.; Orcutt, J. A.; Peach, C. L.; Franks, S. E.

    2004-12-01

    Things are changing at Scripps Institution of Oceanography. Long renowned for excellence in Earth, ocean, atmospheric and interdisciplinary research as well as graduate student training, the Institution is now being called upon to address a new set of challenges. Opportunities to address diverse societal needs abound, and we at Scripps are prepared to respond. As the problems facing the globe in reconciling human and economic development with the limitations of the Earth system become more and more pressing, the potential impact of Scripps research on society grows. The full value of our work cannot be realized unless we share it with established and future economists, international relations specialists, public policy experts, and business leaders. To help our scientists realize this goal while maintaining their research excellence, Scripps has committed to: 1) expanding its faculty's role in undergraduate teaching; 2) establishment of the Center for Educational Outreach Connections that will enable Scripps scientists to participate in educational outreach efforts locally, regionally, nationally and internationally; 3) pursuing joint education programs with other elements of the UCSD community; and 4) launching a new interdisciplinary Center for Earth Observations and Applications in which scholars from throughout the university will develop new collaborations, new technologies, and new knowledge in many fields affecting the environment. Our ambition is to generate a continuous awareness of how Earth is behaving - an awareness that could be an integral part of all kinds of decisions about the environment. Scripps is not alone in recognizing and responding to societal needs. Funding agencies are increasingly requiring scientists to articulate how their research has impact beyond the academic community. With the establishment of the Centers for Ocean Sciences Education Excellence, NSF has led the way in assembling and leveraging the intellectual and organizational

  8. Communicating Ocean Sciences to Informal Audiences (COSIA): Universities, Oceanographic Institutions, Science Centers and Aquariums Working Together to Improve Ocean Education and Public Outreach

    Science.gov (United States)

    Glenn, S.; McDonnell, J.; Halversen, C.; Zimmerman, T.

    2006-12-01

    institutions and promoting the broader impact of research; and provide diverse role models and inquiry-based ocean sciences activities for children and families visiting ISEI. COSIA partners include: Hampton University Virginia Aquarium; Oregon State University Hatfield Marine Science Visitor's Center; Rutgers University Liberty Science Center; University of California, Berkeley Lawrence Hall of Science; and University of Southern California Aquarium of the Pacific. COS has been or will soon be taught at Rutgers University, UC Berkeley, Stanford, Woods Hole Oceanographic Institute, University of Oregon (GK-12 program), Scripps Institution of Oceanography, and others. Data from surveys of students demonstrates improvement in their understanding of how people learn and how to effectively communicate. For example, there was a decrease in agreement with statements describing traditional didactic teaching strategies suggesting that students who took the course developed a more sophisticated, inquiry-based philosophy of learning. Providing college students with a background in current learning theory, and applying that theory through practical science communication experiences, will empower future generations of scientists to meet the communication challenges they will encounter in their careers.

  9. Women oceanographers

    Science.gov (United States)

    The number of female physical oceanographers holding Ph.D's will grow by at least 15% this year when three female oceanography graduate students at Florida State University (FSU) receive their doctorates, according to James J. O'Brien, FSU professor of meteorology and oceanography and editor of the Oceans section of the Journal of Geophysical Research. The students (see Figure 1), Ruth Preller, Germana Peggion, and Sirpa Hakkinen, have all completed requirements for the doctorate degree.

  10. Temperature, salinity, oxygen and other parameter profile data collected by CTD in the NW Atlantic Ocean by Woods Hole Oceanographic Institution, Feb-Mar 1990 (NODC Accession 9100130)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data was collected by the R/V COLUMBUS ISELIN in NW Atlantic (limit-40 W) during the Amazon Shelf Sediment Study (AMASSEDS) from February to March 1990. The data...

  11. A Study on the Feasibility of Creating a Web-Accessible Marine Mammal Sound Library Based upon the Collections at the Woods Hole Oceanographic Institution

    Science.gov (United States)

    2008-09-01

    caused by a nearby ship. Some Physeter clicking throughout recording. 64119 Ambient; Amphibia 12/9/1964 Bligh Sound, New Zealand S45 E167 2 08...are visible. Much reverb. 60024 Amphibia ; Fish, sensu lato; Insecta //1960 Various unknown unknown 1 24:02.884 7 Low ambient recording

  12. Oceanographic Station Data from bottle casts from the KNORR as part of the International Decade of Ocean Exploration (IDOE) from 18 May 1972 to 03 June 1972 (NODC Accession 7200809)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data were collected from bottle casts from the KNORR from 18 May 1972 to 03 June 1972. Data were collected by the Woods Hole Oceanographic...

  13. Oceanographic Monthly Summary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Monthly Summary contains sea surface temperature (SST) analyses on both regional and ocean basin scales for the Atlantic, Pacific, and Indian Oceans....

  14. National oceanographic information system

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, B.N.; Kunte, P.D.; Bhargava, R.M.S.

    Ocean study is inherently interdisciplinary and therefore calls for a controlled and integrated approach for information generation, processing and decision making. In this context, Indian National Oceanographic Data Centre (INODC) of National...

  15. Controlled Vocabularies and Ontologies for Oceanographic Data: The R2R Eventlogger Project

    Science.gov (United States)

    Coburn, E.; Maffei, A. R.; Chandler, C. L.; Raymond, L. M.

    2012-12-01

    Research vessels coordinated by the United States University-National Oceanographic Laboratory System (US-UNOLS) collect data which is considered an important oceanographic resource. The NSF-funded Rolling Deck to Repository (R2R) project aims to improve access to this data and diminish the barriers to use. One aspect of the R2R project has been to develop a shipboard scientific event logging system, Eventlogger, that incorporates best practice guidelines, controlled vocabularies, a cruise metadata schema, and a scientific event log. This will facilitate the eventual ingestion of datasets into oceanographic data repositories for subsequent integration and synthesis by investigators. One important aspect of this system is the careful use of controlled vocabularies and ontologies. Existing ontologies, where available, will be used and others will be developed. The use of internationally-informed, consensus-driven controlled vocabularies will make datasets more interoperable, and discoverable. The R2R Eventlogger project is led by Woods Hole Oceanographic Institution (WHOI), and the management of the controlled vocabularies and mapping of these vocabularies to authoritative community vocabularies are led by the Data Librarian in the Marine Biological Laboratory/Woods Hole Oceanographic Institution (MBLWHOI) Library. The first target vocabulary is oceanographic instruments. Management of this vocabulary has thus far consisted of reconciling local community terms with the more widely used SeaDataNet Device Vocabulary terms. Rather than adopt existing terms, often the local terms are mapped by data managers in the NSF-funded Biological and Chemical Oceanographic Data Management Office (BCO-DMO) to the existing terms as they are given by investigators and often provide important information and meaning. New terms (often custom, or modified instruments) are submitted for review to the SeaDataNet community listserv for discussion and eventual incorporation into the Device

  16. Federated provenance of oceanographic research cruises: from metadata to data

    Science.gov (United States)

    Thomas, Rob; Leadbetter, Adam; Shepherd, Adam

    2016-04-01

    The World Wide Web Consortium's Provenance Data Model and associated Semantic Web ontology (PROV-O) have created much interest in the Earth and Space Science Informatics community (Ma et al., 2014). Indeed, PROV-O has recently been posited as an upper ontology for the alignment of various data models (Cox, 2015). Similarly, PROV-O has been used as the building blocks of a data release lifecycle ontology (Leadbetter & Buck, 2015). In this presentation we show that the alignment between different local data descriptions of an oceanographic research cruise can be achieved through alignment with PROV-O and that descriptions of the funding bodies, organisations and researchers involved in a cruise and its associated data release lifecycle can be modelled within a PROV-O based environment. We show that, at a first-order, this approach is scalable by presenting results from three endpoints (the Biological and Chemical Oceanography Data Management Office at Woods Hole Oceanographic Institution, USA; the British Oceanographic Data Centre at the National Oceanography Centre, UK; and the Marine Institute, Ireland). Current advances in ontology engineering, provide pathways to resolving reasoning issues from varying perspectives on implementing PROV-O. This includes the use of the Information Object design pattern where such edge cases as research cruise scheduling efforts are considered. PROV-O describes only things which have happened, but the Information Object design pattern allows for the description of planned research cruises through its statement that the local data description is not the the entity itself (in this case the planned research cruise) and therefore the local data description itself can be described using the PROV-O model. In particular, we present the use of the data lifecycle ontology to show the connection between research cruise activities and their associated datasets, and the publication of those data sets online with Digital Object Identifiers and

  17. Atlantic Oceanographic and Meteorological Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Atlantic Oceanographic and Meteorological Laboratory conducts research to understand the physical, chemical, and biological characteristics and processes of the...

  18. tiated by the Oceanographic Research Institute (ORI)

    African Journals Online (AJOL)

    spamer

    Bass et al. (1973) continued the study by tagging and releasing a further. 2 316 dusky sharks, of which 97 (4.2%) were recap- tured. Tag returns from that study showed a distinct geographical segregation of dusky sharks in terms of sex and size, and the southern KwaZulu-Natal coast was identified as a primary nursery area ...

  19. Documentation of the U.S. Geological Survey Oceanographic Time-Series Measurement Database

    Science.gov (United States)

    Montgomery, Ellyn T.; Martini, Marinna A.; Lightsom, Frances L.; Butman, Bradford

    2008-01-02

    The U.S. Geological Survey (USGS) Oceanographic Time-Series Data Collection (previously named the USGS Oceanographic Time-Series Measurement Database) contains oceanographic observations made as part of studies designed to increase understanding of sediment transport processes and associated dynamics. Analysis of these data has contributed to more accurate prediction of the movement and fate of sediments and other suspended materials in the coastal ocean. The measurements were collected primarily by investigators at the USGS Woods Hole Coastal and Marine Science Center (WHCMSC) and colleagues, beginning in 1975. Most of the field experiments were carried out on the U.S. continental shelf and slope.

  20. New Navigation Post-Processing Tools for Oceanographic Submersibles

    Science.gov (United States)

    Kinsey, J. C.; Whitcomb, L. L.; Yoerger, D. R.; Howland, J. C.; Ferrini, V. L.; Hegrenas, O.

    2006-12-01

    We report the development of Navproc, a new set of software tools for post-processing oceanographic submersible navigation data that exploits previously reported improvements in navigation sensing and estimation (e.g. Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract OS32A- 0225, 2003). The development of these tools is motivated by the need to have post-processing software that allows users to compensate for errors in vehicle navigation, recompute the vehicle position, and then save the results for use with quantitative science data (e.g. bathymetric sonar data) obtained during the mission. Navproc does not provide real-time navigation or display of data nor is it capable of high-resolution, three dimensional (3D) data display. Navproc supports the ASCII data formats employed by the vehicles of the National Deep Submergence Facility (NDSF) operated by the Woods Hole Oceanographic Institution (WHOI). Post-processing of navigation data with Navproc is comprised of three tasks. First, data is converted from the logged ASCII file to a binary Matlab file. When loaded into Matlab, each sensor has a data structure containing the time stamped data sampled at the native update rate of the sensor. An additional structure contains the real-time vehicle navigation data. Second, the data can be displayed using a Graphical User Interface (GUI), allowing users to visually inspect the quality of the data and graphically extract portions of the data. Third, users can compensate for errors in the real-time vehicle navigation. Corrections include: (i) manual filtering and median filtering of long baseline (LBL) ranges; (ii) estimation of the Doppler/gyro alignment using previously reported methodologies; and (iii) sound velocity, tide, and LBL transponder corrections. Using these corrections, the Doppler and LBL positions can be recomputed to provide improved estimates of the vehicle position compared to those computed in real-time. The data can be saved in either binary or ASCII

  1. TZCF Oceanographic Survey (SE1505)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic data were collected along the 159W and Meridional from 26? 30'N-32? 30'N. CTD casts were conducted at predetermined stations. CTDs were equipped with...

  2. Satellite transmission of oceanographic data

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Desai, R.G.P.; DeSa, E.J.

    Oceanographic data collected on a research vessel has been transmitted to a shore laboratory using the INMARSAT maritime satellite The system configuration used, consisted of Satellite Communication Terminals interfaced to desk top computers...

  3. Black Hole Simulation

    Science.gov (United States)

    1999-01-01

    This graphic shows the computer simulation of a black hole from start to finish. Plasma is falling slowly toward the black hole in a (at the upper left). The plasma has a magnetic field, shown by the white lines. It picks up speed as it falls toward the hole in b (at the upper right), c (lower left) and d (lower right). However, the rotating black hole twists up space itself (and the magnetic field lines) and ejects electromagnetic power along the north and south poles above the black hole. The red and white color shows the immense electromagnetic power output, which eventually will pick up particles and form squirting jets. This simulation was conducted using supercomputers at Japan's National Institute for Fusion Science.

  4. Communications and Control for Enhanced Autonomy in Underwater Vehicles for Deep Oceanographic Research

    Science.gov (United States)

    Jakuba, M.; Kinsey, J. C.; Yoerger, D. R.; Whitcomb, L. L.; Camilli, R.; Murphy, C.; Bowen, A.; German, C. R.

    2010-12-01

    NASA’s Astrobiology Science and Technology for Exploring Planets (ASTEP) program is a science-driven program to produce advances in scientific and technological capabilities for planetary exploration. Oceanographic robotic vehicles and planetary exploration robots have proven to be highly effective scientific tools for performing scientific research in remote, extreme, and hostile environments that preclude direct human presence. In both domains, the planets and the world’s oceans, human oversight of remote robotic exploration can dramatically enhance scientific return in comparison to purely pre-planned missions by combining the perception, intelligence, and domain knowledge of the human operators with the super-human physical and sensory capabilities of robots. The degree of human oversight, however, is restricted in sea and space by physical limits on the bandwidth and time delay of communications between human operators and remote robotic platforms. Enhanced robotic autonomy can alleviate this obstacle. We present a communications and control architecture for underwater oceanographic robot vehicles that has permitted us to introduce elements of enhanced autonomy into operations with the Woods Hole Oceanographic Institution's Autonomous Underwater Vehicles (AUVs) Nereus and Sentry. Our architecture is designed to facilitate: (1) autonomous distillation of scientific data and transmission of salient synopses from the remote vehicle to its human operators; (2) high-level near real-time human supervision and control of mission programming; (3) semi-supervised learning of environmental models for enhanced survey and search mission effectiveness. Specific capabilities our group has demonstrated include selective data delivery via acoustic link; near real-time reprogramming of vehicle mission programs during otherwise preplanned dives; and validation of autonomous decision-making processes with human-supervision. These elements have been recently demonstrated

  5. Oceanographic profile Temperature and Salinity measurements collected using bottle from various platforms in the Arctic Ocean from 1920 to 1934 (NODC Accession 0043759)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity data received at NODC from STATE OCEANOGRAPHIC INSTITUTION; ROSGIDROMET (Moscow) , digitized by the submitting institute as part of the...

  6. Oceanographic station data from bottle casts from UNKNOWN PLATFORMS and Other Platforms from 01 January 1957 to 01 December 1964 (NODC Accession 7400853)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from UNKNOWN PLATFORMS. Data were collected by Danish Institute for Fishery and Marine Research and other institutions from...

  7. Temperature, salinity, and nutrients data from bottle casts in the North Atlantic from the PHYSALIA by the Woods Hole Oceanographic Institute from 23 January 1946 to 13 July 1946 (NODC Accession 0000410)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bottle and other data were collected in the North Atlantic Ocean from the PHYSALIA from 23 January 1946 to 13 July 1946. Bottle data include profiles of temperature,...

  8. Physical trajectory profile data from glider whoi_406 deployed by Woods Hole Oceanographic Institution in the Mid-Atlantic Bight from 2016-09-02 to 2016-09-20 (NCEI Accession 0156640)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slocum glider dataset gathered as part of the TEMPESTS (The Experiment to Measure and Predict East coast STorm Strength), funded by NOAA through CINAR (Cooperative...

  9. Uses of the Drupal CMS Collaborative Framework in the Woods Hole Scientific Community (Invited)

    Science.gov (United States)

    Maffei, A. R.; Chandler, C. L.; Work, T. T.; Shorthouse, D.; Furfey, J.; Miller, H.

    2010-12-01

    Organizations that comprise the Woods Hole scientific community (Woods Hole Oceanographic Institution, Marine Biological Laboratory, USGS Woods Hole Coastal and Marine Science Center, Woods Hole Research Center, NOAA NMFS Northeast Fisheries Science Center, SEA Education Association) have a long history of collaborative activity regarding computing, computer network and information technologies that support common, inter-disciplinary science needs. Over the past several years there has been growing interest in the use of the Drupal Content Management System (CMS) playing a variety of roles in support of research projects resident at several of these organizations. Many of these projects are part of science programs that are national and international in scope. Here we survey the current uses of Drupal within the Woods Hole scientific community and examine reasons it has been adopted. The promise of emerging semantic features in the Drupal framework is examined and projections of how pre-existing Drupal-based websites might benefit are made. Closer examination of Drupal software design exposes it as more than simply a content management system. The flexibility of its architecture; the power of its taxonomy module; the care taken in nurturing the open-source developer community that surrounds it (including organized and often well-attended code sprints); the ability to bind emerging software technologies as Drupal modules; the careful selection process used in adopting core functionality; multi-site hosting and cross-site deployment of updates and a recent trend towards development of use-case inspired Drupal distributions casts Drupal as a general-purpose application deployment framework. Recent work in the semantic arena casts Drupal as an emerging RDF framework as well. Examples of roles played by Drupal-based websites within the Woods Hole scientific community that will be discussed include: science data metadata database, organization main website, biological

  10. Oceanographic data collected from station Scripps Pier in the Coastal Waters of California by Southern California Coastal Ocean Observing System (SCCOOS) at Scripps Institution of Oceanography (SIO) and assembled by Southern California Coastal Ocean Observing System (SCCOOS) Regional Association from 2005-06-16 to 2016-12-31 (NCEI Accession 0157035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157035 contains oceanographic and surface meteorological data collected from an automated shore station with a suite of sensors that are attached to...

  11. Oceanographic and surface meteorological data collected from station sispnj by Florida Institute of Technology (FIT) and assembled by Southeast Coastal Ocean Observing Regional Association (SECOORA) in the Coastal Waters of Florida and North Atlantic Ocean from 2014-02-27 to 2015-07-18 (NODC Accession 0118769)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Accession 0118769 contains oceanographic and surface meteorological data in netCDF formatted files, which follow the Climate and Forecast metadata convention (CF)...

  12. Japanese Oceanographic Data Center Japan Land Gravity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (4,381 records) were compiled by the Japanese Oceanographic Data Center. This data base was received in July 1988. The data are in the...

  13. TZCF Oceanographic Survey (SE0802, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic data were collected along the 158?W Meridional from 22?30?N-35?00?N. CTD cats were conducted at predetermined stations. CTDs were equipped with oxygen...

  14. Mooring Line for an Oceanographic Buoy System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A mooring line for an oceanographic buoy system includes four sections. The first section is a protected cable that is connectable to the buoy. The second section is...

  15. Role of LAN in oceanographic information management

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Bhargava, R.M.S.

    ) LAN and its capabilities, (2) information processing infrastructure at NIO, (3) functioning of INODC and (4) suitability of LAN in increasing efficiency in oceanographic information management. It has been concluded that, LAN can play a very...

  16. Coronal Holes

    Directory of Open Access Journals (Sweden)

    Steven R. Cranmer

    2009-09-01

    Full Text Available Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations, and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are established in the extended corona. For example, the importance of kinetic plasma physics and turbulence in coronal holes has been affirmed by surprising measurements from the UVCS instrument on SOHO that heavy ions are heated to hundreds of times the temperatures of protons and electrons. These observations point to specific kinds of collisionless Alfvén wave damping (i.e., ion cyclotron resonance, but complete theoretical models do not yet exist. Despite our incomplete knowledge of the complex multi-scale plasma physics, however, much progress has been made toward the goal of understanding the mechanisms ultimately responsible for producing the observed properties of coronal holes.

  17. Helping parents live with the hole in their heart: The role of health care providers and institutions in the bereaved parents' grief journeys.

    Science.gov (United States)

    Snaman, Jennifer M; Kaye, Erica C; Torres, Carlos; Gibson, Deborah V; Baker, Justin N

    2016-09-01

    Bereaved parents experience significant psychosocial and health sequelae, suggesting that this population may benefit from the ongoing extension of support and resources throughout the grief journey. The interaction of hospital staff with patients and families at the end of a child's life and after death profoundly affects parental grief, offering a unique opportunity for the medical community to positively impact the bereavement experience. The current study was conducted to explore the role of the health care team and medical institutions in the grief journeys of parents whose child died a cancer-related death. Eleven bereaved parents participated in 2 focus groups. Responses to each of the 3 main prompts were coded and analyzed independently using semantic content analysis techniques. Four main concepts were identified within the parental narratives, including the importance of strong and ongoing relationships between providers and bereaved families, the importance of high-quality communication, the effect of negative experiences between providers and families on parental grief, and the importance of the institution's role in the grief journeys of bereaved parents. Bereaved parents consistently identified the critical role played by medical staff and medical institutions throughout the grief journey. Key components of bereavement support identified by parents should serve to guide the actions of providers as well as provide a template for the development of a comprehensive bereavement program within an institution. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2757-2765. © 2016 American Cancer Society. © 2016 American Cancer Society.

  18. Quantum black holes

    CERN Document Server

    Calmet, Xavier; Winstanley, Elizabeth

    2014-01-01

    Written by foremost experts, this short book gives a clear description of the physics of quantum black holes. The reader will learn about quantum black holes in four and higher dimensions, primordial black holes, the production of black holes in high energy particle collisions, Hawking radiation, black holes in models of low scale quantum gravity and quantum gravitational aspects of black holes.

  19. Points of Contact for Oceanographic Institutes in Europe and Russia

    Science.gov (United States)

    1993-05-20

    Cellular: :,i¢ategouy- instrumentation Notes: Pme ?•wfti Instituto di Ricerche aftl Vlf•il.fltmm 3971 55313 First Name: Elio Middle in"i: Last Name...Address 1: Plarnlcon dole t Recherche, Sci ot Tech Address 2: B.P. 1346 City Rebot State: Zip+ 4: Country: Maroc Phone: Fax: Home Phone: Cellular...rArmement A-192 -Sournia Directeur de recherche au CNRS FRONTAL First Name: A- dle Initial:. Name Sournia Tide: Dr. Company: Directeur de recherche au

  20. Physical oceanographic investigation procedure for a sea - Outfall project

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Sarma, R.V.

    oceanographic investigations are inevitable at each location of interest for proper planning and design of an outfall. Indeed, besides physical oceanographic parameters the overall planning also requires, chemical, biological, geological and engineering...

  1. ICON - North Norman's Patch Reef 2004 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  2. ICON - Media Luna Reef 2010 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  3. ICON - Media Luna Reef 2009 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  4. ICON - Salt River Bay 2010 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  5. ICON - Little Cayman, Cayman Islands 2010 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  6. ICON - Salt River Bay 2005 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  7. ICON - Salt River Bay 2009 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  8. ICON - Little Cayman, Cayman Islands 2009 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  9. ICON - North Norman's Patch Reef 2005 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  10. ICOADS: Lessons Learned and Oceanographic Data Linkages

    Science.gov (United States)

    Worley, S. J.; Freeman, E.; Angel, W.; Brohan, P.; Dumenil-Gates, L.; Kent, E. C.; Smith, S. R.; Woodruff, S. D.

    2016-02-01

    The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is the largest collection of surface marine in situ observations, spanning 1662 to present, and provides access to a wealth of surface atmospheric elements over the ocean. This presentation will review a number of past innovations in ICOADS data management and quality control. More recently for example, in developing ICOADS Release 3.0 (planned for availability by mid 2016), the benefits of including a more extensive range of near-surface oceanographic parameters alongside surface meteorological parameters are being realized. A new Near-Surface Oceanographic (Nocn) "attachment" to the extensible International Maritime Meteorological Archive (IMMA) format has been developed to include oceanographic elements, such as near-surface salinity and temperature, their associated measurement depths and other selected observational metadata. The inclusion of the oceanographic parameters allows users to locate surface oceanographic and lower atmospheric observations over the ocean within a single dataset and in a common format, for potential uses such as studies of air-sea interactions and coupled ocean-atmosphere model validations. Release 3.0 includes near-surface ocean profile measurements from sources such as the World Ocean Database (WOD 2013). In addition, the Nocn attachment will be used to provide underway surface ocean observations from ships participating in the Shipboard Automated Meteorological and Oceanographic System (SAMOS) and Global Ocean Surface Underway Data (GOSUD) initiatives, and to expand the range of parameters available from moored buoys. An in-depth description of the Nocn attachment, lessons learned during its development, and anticipated uses and advantages for the marine community will be further discussed.

  11. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    Science.gov (United States)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  12. Strange Bedfellows; Physical and Biological Oceanographers

    Science.gov (United States)

    Wooster, W. S.

    2002-12-01

    When I started graduate study at Scripps in 1947, both the text, "The Oceans", and the curriculum - all students took the introductory courses in physics, chemistry, biology, and geology - conspired to create awareness of the interactions among these fields. In their preface, the authors spoke of the book as "an aid to the beginner and specialist alike in the coordination of the various fields of oceanography." Harald Sverdrup, perhaps the best known physical oceanographer of his day, introduced us to the interdisciplinary organization, ICES, wrote an important paper (1953) on "the vernal blooming of phytoplankton", and together with fishery biologist O.E.Sette, launched the world renowned CalCOFI program. Another noted physical oceanographer, Henry Stommel, 1949, teamed up with biologist Gordon Riley in a major study of the quantitative ecology of plankton. At the time, physical and biological oceanographers often seemed to be engaged in the same mission. The curriculum format, with its four basic courses, spread to most other graduate programs in oceanography, but the forces of specialization also spread. While the biological oceanographers have always seen the need to understand the milieu within which their creatures function, the physicists often seemed to chafe against wasting their time on squishy subjects like biology when there were so many more important and fascinating things to study. Interactions were further complicated by the confusion between "biological oceanography" and "marine biology", and by the status of "fishery biology" which was often disdained by oceanographers of all stripes. I propose to discuss the evolution of the relationship among these fields during the 60 years since "The Oceans" was first published, concluding with the present marriage of convenience, or at least amicable co-habitation, forced by the widespread concern over the threat of global warming and the need to understand its consequences. It has become clear that

  13. CSIR - National Institute of Oceanography

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    ), the largest international collaborative effort ever undertaken in the oceans. The institute has since grown into a multi- disciplinary oceanographic research institution of international repute. The principal focus of research has been on observing... (JGOFS) and Climate and Ocean: Variability, Predictability and Change (CLIVAR), but also to conduct research under various in-house and national programmes. A number of important bilateral projects were also undertaken especially in collaboration...

  14. Oceanographic Station Data from bottle casts from the MELVILLE as part of the International Decade of Ocean Exploration / Geochemical Ocean Study (IDOE/GEOSECS) from 30 August 1973 to 08 June 1974 (NODC Accession 7601522)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data were collected from bottle casts from the MELVILLE from 30 August 1973 to 08 June 1974. Data were collected by the Scripps Institution of...

  15. Surfing a Black Hole

    Science.gov (United States)

    2002-10-01

    Star Orbiting Massive Milky Way Centre Approaches to within 17 Light-Hours [1] Summary An international team of astronomers [2], lead by researchers at the Max-Planck Institute for Extraterrestrial Physics (MPE) , has directly observed an otherwise normal star orbiting the supermassive black hole at the center of the Milky Way Galaxy. Ten years of painstaking measurements have been crowned by a series of unique images obtained by the Adaptive Optics (AO) NAOS-CONICA (NACO) instrument [3] on the 8.2-m VLT YEPUN telescope at the ESO Paranal Observatory. It turns out that earlier this year the star approached the central Black Hole to within 17 light-hours - only three times the distance between the Sun and planet Pluto - while travelling at no less than 5000 km/sec . Previous measurements of the velocities of stars near the center of the Milky Way and variable X-ray emission from this area have provided the strongest evidence so far of the existence of a central Black Hole in our home galaxy and, implicitly, that the dark mass concentrations seen in many nuclei of other galaxies probably are also supermassive black holes. However, it has not yet been possible to exclude several alternative configurations. In a break-through paper appearing in the research journal Nature on October 17th, 2002, the present team reports their exciting results, including high-resolution images that allow tracing two-thirds of the orbit of a star designated "S2" . It is currently the closest observable star to the compact radio source and massive black hole candidate "SgrA*" ("Sagittarius A") at the very center of the Milky Way. The orbital period is just over 15 years. The new measurements exclude with high confidence that the central dark mass consists of a cluster of unusual stars or elementary particles, and leave little doubt of the presence of a supermassive black hole at the centre of the galaxy in which we live . PR Photo 23a/02 : NACO image of the central region of the Milky Way

  16. Black hole dynamics in general relativity

    Indian Academy of Sciences (India)

    69, No. 1. — journal of. July 2007 physics pp. 77–92. Black hole dynamics in general relativity. ABHAY ASHTEKAR. 1,2. 1. Institute for Gravitational Physics and Geometry, Physics Department,. Penn State University, University Park, PA 16802, USA. 2. Institute for Theoretical Physics, University of Utrecht, Princetonplein 5,.

  17. Life inside black holes

    OpenAIRE

    Dokuchaev, V. I.

    2012-01-01

    We consider test planet and photon orbits of the third kind inside a black hole, which are stable, periodic and neither come out of the black hole nor terminate at the singularity. Interiors of supermassive black holes may be inhabited by advanced civilizations living on planets with the third-kind orbits. In principle, one can get information from the interiors of black holes by observing their white hole counterparts.

  18. Mineralogy and Origin of Sediments From Drill Holes on the Continental Margin Off Florida, 1965-1969 (NODC Accession 7100714)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Drill cores obtained during the Joint Oceanographic Institutions' Deep Earth Sampling Program from the continental shelf, the Florida-Hatteras Slope, and the Blake...

  19. NODC Standard Product: Oceanographic station profile time series (NODC Accession 0095191)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanographic Data Center and the World Data Center-A for Oceanography compiled from the NODC Oceanographic Station Data File a set of oceanographic...

  20. Higher spin black holes

    National Research Council Canada - National Science Library

    Gutperle, Michael; Kraus, Per

    2011-01-01

    .... We find solutions that generalize the BTZ black hole and carry spin-3 charge. The black hole entropy formula yields a result for the asymptotic growth of the partition function at finite spin-3 chemical potential...

  1. A Framework for Integrating Oceanographic Data Repositories

    Science.gov (United States)

    Rozell, E.; Maffei, A. R.; Beaulieu, S. E.; Fox, P. A.

    2010-12-01

    Oceanographic research covers a broad range of science domains and requires a tremendous amount of cross-disciplinary collaboration. Advances in cyberinfrastructure are making it easier to share data across disciplines through the use of web services and community vocabularies. Best practices in the design of web services and vocabularies to support interoperability amongst science data repositories are only starting to emerge. Strategic design decisions in these areas are crucial to the creation of end-user data and application integration tools. We present S2S, a novel framework for deploying customizable user interfaces to support the search and analysis of data from multiple repositories. Our research methods follow the Semantic Web methodology and technology development process developed by Fox et al. This methodology stresses the importance of close scientist-technologist interactions when developing scientific use cases, keeping the project well scoped and ensuring the result meets a real scientific need. The S2S framework motivates the development of standardized web services with well-described parameters, as well as the integration of existing web services and applications in the search and analysis of data. S2S also encourages the use and development of community vocabularies and ontologies to support federated search and reduce the amount of domain expertise required in the data discovery process. S2S utilizes the Web Ontology Language (OWL) to describe the components of the framework, including web service parameters, and OpenSearch as a standard description for web services, particularly search services for oceanographic data repositories. We have created search services for an oceanographic metadata database, a large set of quality-controlled ocean profile measurements, and a biogeographic search service. S2S provides an application programming interface (API) that can be used to generate custom user interfaces, supporting data and application

  2. Monopole black hole skyrmions

    OpenAIRE

    Moss, I.G.; Shiiki, N.; Winstanley, E.

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  3. 46 CFR 188.10-53 - Oceanographic research vessel.

    Science.gov (United States)

    2010-10-01

    ... research, including those studies about the sea such as seismic, gravity meter, and magnetic exploration... 46 Shipping 7 2010-10-01 2010-10-01 false Oceanographic research vessel. 188.10-53 Section 188.10-53 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS...

  4. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  5. Charged cosmological black hole

    Science.gov (United States)

    Moradi, Rahim; Stahl, Clément; Firouzjaee, Javad T.; Xue, She-Sheng

    2017-11-01

    The cosmological black holes are black holes living not in an asymptotically flat universe but in an expanding spacetime. They have a rich dynamics especially for their mass and horizon. In this article, we perform a natural step in investigating this new type of black hole: we consider the possibility of a charged cosmological black hole. We derive the general equations of motion governing its dynamics and report a new analytic solution for the special case of the charged Lematre-Tolman-Bondi equations of motion that describe a charged cosmological black hole. We then study various relevant quantities for the characterization of the black hole, such as the C-function, the effect of the charge on the black hole flux, and the nature of the singularity. We also perform numerical investigations to strengthen our results. Finally, we challenge a model of gamma ray burst within our framework.

  6. Oceanographic and Biogeochemical Insights from Diatom Genomes

    Science.gov (United States)

    Bowler, Chris; Vardi, Assaf; Allen, Andrew E.

    2010-01-01

    Diatoms are the most successful group of eukaryotic phytoplankton in the modern ocean and have risen to dominance relatively quickly over the last 100 million years. Recently completed whole genome sequences from two species of diatom, Thalassiosira pseudonana and Phaeodactylum tricornutum, have revealed a wealth of information about the evolutionary origins and metabolic adaptations that have led to their ecological success. A major finding is that they have incorporated genes both from their endosymbiotic ancestors and by horizontal gene transfer from marine bacteria. This unique melting pot of genes encodes novel capacities for metabolic management, for example, allowing the integration of a urea cycle into a photosynthetic cell. In this review we show how genome-enabled approaches are being leveraged to explore major phenomena of oceanographic and biogeochemical relevance, such as nutrient assimilation and life histories in diatoms. We also discuss how diatoms may be affected by climate change-induced alterations in ocean processes.

  7. Black Holes Have Simple Feeding Habits

    Science.gov (United States)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  8. Using STOQS to Understand Molecular Biology and Oceanographic Data

    Science.gov (United States)

    McCann, M. P.; Ryan, J. P.; Messié, M.; Harvey, J.; Cline, D.; Michisaki, R.

    2014-12-01

    Advances in technology enable us to collect massive amounts of diverse data. With the ability to collect more data, the problem of comparative analysis becomes increasing difficult. The Monterey Bay Aquarium Research Institute (MBARI) designed the Spatial Temporal Oceanographic Query System (STOQS) to create new capabilities for scientists to gain insight from data collected by oceanographic platforms. STOQS uses a geospatial database and a web-based user interface (UI) to allow scientists to explore large collections of data. The UI is optimized to provide a quick overview of data in spatial and temporal dimensions, as well as in parameter and platform space. A user may zoom into a feature of interest and select it, initiating a filter operation updating the UI with an overview of all the data in the new filtered selection. When details are desired, radio buttons and check boxes can be selected to generate a number of different types of visualizations. These include color-filled temporal section plots, parameter-parameter plots, and both 2D and 3D spatial visualizations. The ISO/IEC 19775-1, Extensible 3D (X3D) standard provides the technology for presenting 3D data in a web browser. STOQS has been in use at MBARI for four years and is helping us manage and visualize data from month-long multi-platform observational campaigns. These campaigns produce tens of millions of diverse measurements. These volumes are too great to really understand - even with an effective data exploration UI. Effective management of these diverse data in STOQS is achieved through a two-step harmonization process: 1) conversion of all data to OGC CF-NetCDF Discrete Sampling Geometry feature types and 2) loading all data into the STOQS data model. Having all of the data easily accessible via this data model made development of the UI possible. This same method of access is also being used for development of visualization and analysis programs for tasks that cannot be executed within the UI

  9. Sustainable Oceanographic Vessels - Setting an Example

    Science.gov (United States)

    van Leer, J. C.

    2009-12-01

    In response to climate change, global warming and post “peak oil” fuel scarcity, the oceanographic community should consider reducing its carbon foot print. Why should scientists operate inefficient vessels while lecturing the general public on the need to reduce CO2 emissions? We have already seen curtailment of ship schedules and ship lay-ups, due in part to rising fuel costs, following $140/barrel crude oil. When the global recession ends, upward pressure on oil prices will again commence. Who can forecast how high fuel prices may ultimately rise during the typical 25-30 year lifetime of a research vessel? Are we to curtail future work at sea when oceanic climate research is becoming ever more important? A catamaran research vessel has been designed which can be electrically propelled from by a combination of high efficiency generators, photovoltaic panels and/or sails. Sail produced power is transformed with propellers and motor/generators into electric power which is stored in battery banks. This vessel could operate as the first true hybrid oceanographic research vessel. It could even continue operations without fuel in cases of a severe fuel shortage or fueling denial. Since the power produced by any water turbine increases with the cube of the velocity flowing over its propeller, the low fluid friction and high stability of a catamaran, with reasonably slender hulls, provide an important boost to efficient hybrid operation. The author has chartered a 42’ hybrid catamaran sailboat and found it efficient and extremely easy to operate and control. A 79’ motor sailing catamaran research vessel by Lock Crowther Designs will be presented as one example of a sustainable research vessel with excellent speed and sea-keeping. A center well makes operation as a small drilling/coring ship for coastal climate investigation possible. The center well also supports a host of remote sensing and robotic gear handling capabilities.

  10. Stimulated Black Hole Evaporation

    CERN Document Server

    Spaans, Marco

    2016-01-01

    Black holes are extreme expressions of gravity. Their existence is predicted by Einstein's theory of general relativity and is supported by observations. Black holes obey quantum mechanics and evaporate spontaneously. Here it is shown that a mass rate $R_f\\sim 3\\times 10^{-8} (M_0/M)^{1/2}$ $M_0$ yr$^{-1}$ onto the horizon of a black hole with mass $M$ (in units of solar mass $M_0$) stimulates a black hole into rapid evaporation. Specifically, $\\sim 3 M_0$ black holes can emit a large fraction of their mass, and explode, in $M/R_f \\sim 3\\times 10^7 (M/M_0)^{3/2}$ yr. These stimulated black holes radiate a spectral line power $P \\sim 2\\times 10^{39} (M_0/M)^{1/2}$ erg s$^{-1}$, at a wavelength $\\lambda \\sim 3\\times 10^5 (M/M_0)$ cm. This prediction can be observationally verified.

  11. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  12. Oceanographic Data Repositories: An Analysis of the International Situation

    Directory of Open Access Journals (Sweden)

    Fabiano Couto Corrêa da Silva

    2017-04-01

    Full Text Available The preservation and organization of oceanographic research data enables the scientific community to consult and reuse information of different kinds, and this is made possible by the repositories, meaning the services that facilitate data storage and dissemination. This paper reviews the current situation of oceanographic data repositories across different countries and evaluates them according to a series of indicators. The writers propose that although interest in storing and reusing oceanographic data has increased in recent years, the repositories are still in the process of developing their systems for processing, disseminating and reusing data. The repositories also differ in terms of architecture and the organizational level of the content they offer.

  13. Chandrasekhar, Black Holes, and Singularities Roger Penrose

    Indian Academy of Sciences (India)

    Administrator

    Mathematical Institute, University of Oxford, Oxford 0X1 3LB, UK. 1. .... (Lifshitz and Khalatnikov had omitted a certain degree of freedom in their .... abled him to separate and decouple the equations. Chandra was a relative latecomer to the study of black holes. In his early work on white dwarf stars and the inevitability of their ...

  14. Hole crystallization in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bonitz, M [Institut fuer Theoretische Physik und Astrophysik, Christian-Albrechts-Universitaet Kiel, 24098 Kiel (Germany); Filinov, V S [Institut fuer Theoretische Physik und Astrophysik, Christian-Albrechts-Universitaet Kiel, 24098 Kiel (Germany); Fortov, V E [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation); Levashov, P R [Institute for High Energy Density, Russian Academy of Sciences, Izhorskay 13/19, Moscow 127412 (Russian Federation); Fehske, H [Institut fuer Physik, Universitaet Greifswald, l7487 Greifswald (Germany)

    2006-04-28

    When electrons in a solid are excited to a higher energy band they leave behind a vacancy (hole) in the original band which behaves like a positively charged particle. Here we predict that holes can spontaneously order into a regular lattice in semiconductors with sufficiently flat valence bands. The critical hole to electron effective mass ratio required for this phase transition is found to be of the order of 80.

  15. Hole crystallization in semiconductors

    OpenAIRE

    Bonitz, M.; Filinov, V. S.; Fortov, V. E.; Levashov, P. R.; Fehske, H.

    2005-01-01

    When electrons in a solid are excited to a higher energy band they leave behind a vacancy (hole) in the original band which behaves like a positively charged particle. Here we predict that holes can spontaneously order into a regular lattice in semiconductors with sufficiently flat valence bands. The critical hole to electron effective mass ratio required for this phase transition is found to be of the order of 80.

  16. Measuring spin of black holes in the universe

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Measuring spin of black holes in the universe. Department of Physics Indian Institute of Science Bangalore. Notes: 74th Annual Meeting of Indian Academy of Science.

  17. Asymptotic black holes

    Science.gov (United States)

    Ho, Pei-Ming

    2017-04-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  18. Revisiting Black Holes as Dark Matter

    Science.gov (United States)

    Kohler, Susanna

    2017-02-01

    /Jason Cowan (Astronomy Technology Center)]A team of scientists led by Evencio Mediavilla (Institute of Astrophysics of the Canaries, University of La Laguna) has now used our observations of quasar microlensing to place constraints on the amount of dark matter that could be made up of intermediate-mass primordial black holes.Poor Outlook for Primordial Black HolesMediavilla and collaborators used simulations to estimate the effects of a distribution of masses on light from distant quasars, and they then compared their results to microlensing magnification measurements from 24 gravitationally lensed quasars. In this way, they were able to determine both the abundance and masses of possible objects causing the quasar microlensing effects we see.The authors find that the observations constrain the mass of the possible microlensing objects to be between 0.05 and 0.45 solar masses not at all the intermediate-mass black holes postulated. Whats more, they find that the lensing objects make up 20% of the total matter, which is barely more than expected for normal stellar matter. This suggests that normal stars are doing the majority of the quasar microlensing, not a large population of intermediate-mass black holes.What does this mean for primordial black holes as dark matter? Black holes in the range of 10200 stellar masses are unlikely to account for much (if any) dark matter, Mediavilla and collaborators conclude which means that LIGOs detection of gravitational waves likely came from two black holes collapsed from stars, not primordial black holes.CitationE. Mediavilla et al 2017 ApJL 836 L18. doi:10.3847/2041-8213/aa5dab

  19. Oceanographic profile temperature, salinity, and nutrients measurements collected using bottle, XBT, CTD, XCTD from various platforms in the Atlantic and Pacific from 2001 to 2007 (NODC Accession 0045591)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are pleased to send you the Oceanographic Data observed by research institutes in Japan as a part of the lODE activity promoted by IOC/UNESCO. Enclosed CD-ROM...

  20. Oceanographic measurements from the Texas Automated Buoy System (TABS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Texas Automated Buoy System contains daily oceanographic measurements from seven buoys off the Texas coast from Brownsville to Sabine. The Texas General Land...

  1. U.S. Naval Oceanographic Office Cores (BOCKMAN65 shapefile)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The results of the sediment size analysis performed by the U.S.Naval Oceanographic Office Geological Laboratory for six Phleger gravity cores are presented in this...

  2. TZCF Oceanographic Survey (SE0902L1, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic data were collected along the 158?W Meridional from 22?30?N-36?00?N. CTD cats were conducted at predetermined stations. CTDs were equipped with oxygen...

  3. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of ...

  4. Black hole levitron

    NARCIS (Netherlands)

    Arsiwalla, X.D.; Verlinde, E.P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.’s multicenter

  5. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  6. Black hole Berry phase

    NARCIS (Netherlands)

    de Boer, J.; Papadodimas, K.; Verlinde, E.

    2009-01-01

    Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry’s phase: under adiabatic variations of the

  7. Black holes an introduction

    CERN Document Server

    Raine, Derek

    2005-01-01

    This introduction to the fascinating subject of black holes fills a significant gap in the literature which exists between popular, non-mathematical expositions and advanced textbooks at the research level. It is designed for advanced undergraduates and first year postgraduates as a useful stepping-stone to the advanced literature. The book provides an accessible introduction to the exact solutions of Einstein’s vacuum field equations describing spherical and axisymmetric (rotating) black holes. The geometry and physical properties of these spacetimes are explored through the motion of particles and light. The use of different coordinate systems, maximal extensions and Penrose diagrams is explained. The association of the surface area of a black hole with its entropy is discussed and it is shown that with the introduction of quantum mechanics black holes cease to be black and can radiate. This result allows black holes to satisfy the laws of thermodynamics and thus be consistent with the rest of physics.

  8. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical ...

  9. The Thermodynamics of Black Holes

    National Research Council Canada - National Science Library

    Emparan, Roberto; Tinto, Massimo; Barbero G, J Fernando; Heusler, Markus; Rendall, Alan D; Adamo, Timothy M; Liebling, Steven L; Sasaki, Misao; Poisson, Eric; Wald, Robert M; Postnov, Konstantin A; Amendola, Luca; Shibata, Masaru; Tagoshi, Hideyuki; Reall, Harvey S; Kozameh, Carlos; Palenzuela, Carlos; Yungelson, Lev R; Villaseñor, Eduardo J. S; Appleby, Stephen; Taniguchi, Keisuke; Dhurandhar, Sanjeev V; Bacon, David; Newman, Ezra T; Baker, Tessa; Baldi, Marco; Bartolo, Nicola; Blanchard, Alain; Bonvin, Camille; Borgani, Stefano; Branchini, Enzo; Burrage, Clare; Camera, Stefano; Carbone, Carmelita; Casarini, Luciano; Cropper, Mark; de Rham, Claudia; Di Porto, Cinzia; Ealet, Anne; Ferreira, Pedro G; Finelli, Fabio; García-Bellido, Juan; Giannantonio, Tommaso; Guzzo, Luigi; Heavens, Alan; Heisenberg, Lavinia; Heymans, Catherine; Hoekstra, Henk; Hollenstein, Lukas; Holmes, Rory; Horst, Ole; Jahnke, Knud; Kitching, Thomas D; Koivisto, Tomi; Kunz, Martin; La Vacca, Giuseppe; March, Marisa; Majerotto, Elisabetta; Markovic, Katarina; Marsh, David; Marulli, Federico; Massey, Richard; Mellier, Yannick; Mota, David F; Nunes, Nelson J; Percival, Will; Pettorino, Valeria; Porciani, Cristiano; Quercellini, Claudia; Read, Justin; Rinaldi, Massimiliano; Sapone, Domenico; Scaramella, Roberto; Skordis, Constantinos; Simpson, Fergus; Taylor, Andy; Thomas, Shaun; Trotta, Roberto; Verde, Licia; Vernizzi, Filippo; Vollmer, Adrian; Wang, Yun; Weller, Jochen; Zlosnik, Tom

    ...We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds...

  10. Hole-ness of point clouds

    Science.gov (United States)

    Gronz, Oliver; Seeger, Manuel; Klaes, Björn; Casper, Markus C.; Ries, Johannes B.

    2015-04-01

    Accurate and dense 3D models of soil surfaces can be used in various ways: They can be used as initial shapes for erosion models. They can be used as benchmark shapes for erosion model outputs. They can be used to derive metrics, such as random roughness... One easy and low-cost method to produce these models is structure from motion (SfM). Using this method, two questions arise: Does the soil moisture, which changes the colour, albedo and reflectivity of the soil, influence the model quality? How can the model quality be evaluated? To answer these questions, a suitable data set has been produced: soil has been placed on a tray and areas with different roughness structures have been formed. For different moisture states - dry, medium, saturated - and two different lighting conditions - direct and indirect - sets of high-resolution images at the same camera positions have been taken. From the six image sets, 3D point clouds have been produced using VisualSfM. The visual inspection of the 3D models showed that all models have different areas, where holes of different sizes occur. But it is obviously a subjective task to determine the model's quality by visual inspection. One typical approach to evaluate model quality objectively is to estimate the point density on a regular, two-dimensional grid: the number of 3D points in each grid cell projected on a plane is calculated. This works well for surfaces that do not show vertical structures. Along vertical structures, many points will be projected on the same grid cell and thus the point density rather depends on the shape of the surface but less on the quality of the model. Another approach has been applied by using the points resulting from Poisson Surface Reconstructions. One of this algorithm's properties is the filling of holes: new points are interpolated inside the holes. Using the original 3D point cloud and the interpolated Poisson point set, two analyses have been performed: For all Poisson points, the

  11. Imaging display method for airborne oceanographic LIDAR

    Science.gov (United States)

    Davis, Jon P.; Keck, Timothy; Umehara, Michael J.

    1990-09-01

    Typical airborne Light Detection and Ranging (LIDAR) used for oceanographic measurements collect data at rates in the range of 1 Megabyte per second. This paper presents a method for organizing and displaying this great bulk of data to allow screening for areas of interest. In addition, this method can be transferred to dedicated hardware, to provide a 100% real time data display system at a reasonable cost. A typical airborne LIDAR system contains a scanning transceiver, and digitizes returned waveforms as the aircraft ffies some search pattern. Thus the data is inherently four dimensional (intensity and three spatial dimensions). This method reliesupon collapsing the four dimensional data into three dimensions; color and X,Y screen coordinates. This is doneby translating depth into an RGB color mix, and return intensity into RGB intensity. Thus color represents depth, and brightness represents signal strength. This data is then displayed on a high resolution color display. In order for this to be successful, some preprocessing is necessary to normalize the waveforms, so that changes in the displayreflect changes in the water column. In addition, some digital filtering is beneficial to increase the signal to noise ratio. This system is currentlyimplemented in Greenhills 'C' under CLIX (UnixVport toClipper) running on a Zaiaz 933 compute engine, with RASIL graphics software package on a Zaiaz FB 640 Graphics frame buffer. This hardware provides 5 MIPS average execution rate and 16.7 million colors on a 768 x 576 pixel display.

  12. Antarctic Ozone Hole, 2000

    Science.gov (United States)

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  13. Seasonality and variability of coccolithophore fluxes in response to diverse oceanographic regimes in the Bay of Bengal: sediment trap results. M.V.S. Gupthaa & b, Lina P. Mergulhaoa,*, Daniela Ungerc and V.S.N. Murtyd a National Institute of Oceanography, Dona Paula, Goa - 403 004, India b 62, Sagar Society, Dona Paula, Goa - 403 004, India c Center for Tropical Marine Ecology, Fahrenheitstrasse 6, D 28359 Bremen, Germany d National Institute of Oceanography, 176, Lawsons Bay Colony, Visakhapatnam - 530 017, India

    Science.gov (United States)

    Medimi, M.

    2011-12-01

    A study on coccolithophores both in shallow and deep sediment trap samples, collected over a period of one year (January 1992 - December 1992) from three trap locations in the Bay of Bengal were used to understand their production and export processes in relation to diverse oceanographic regimes associated with reversing monsoons. A total of 25 species of coccolithophores were identified, which includes some of the important species, Gephyrocapsa oceanica, Umbilicosphaera sibogae, Florisphaera profunda, Umbellosphaera irregularis, Emiliania huxleyi, Oolithotus antillarum, Umbellosphaera tenuis, Helicosphaera carteri and Calcidiscus leptoporus. The total coccolithophore fluxes increased from the northern to southern Bay of Bengal where G. oceanica, U. sibogae¬ and E. huxleyi were dominant species displaying seasonality with peak fluxes occurring during southwest (SW) and northeast (NE) monsoons reflecting their affinity for nutrient-rich waters brought in by river plumes, divergences and cyclonic eddies. U. irregularis, an indicator of oligotrophic/warm water, recorded peak abundance fluxes only during the spring intermonsoon period at all trap locations thus inferring its preference for oligotrophic conditions caused by increased Sea Surface Temperature (SST), stratification and lack of nutrient supply due to weak wind velocities. The deep dwelling species, F. profunda recorded high fluxes during the fall intermonsoon (October/November) in the northern and southern traps and during the spring intermonsoon. The peak fluxes during the spring intermonsoon (April/May) in the central and southern traps indicated the prevalence of a deep nutricline when oligotrophic conditions prevailed at the surface. Interestingly, dissolution was encountered throughout the year evidenced by the presence of corroded coccoliths.

  14. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)

    2015-05-11

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  15. Scalarized Hairy Black Holes

    CERN Document Server

    Kleihaus, Burkhard; Yazadjiev, Stoytcho

    2015-01-01

    In the presence of a complex scalar field scalar-tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and ordinary hairy black holes. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  16. Black hole uncertainties

    CERN Document Server

    Danielsson, U H

    1993-01-01

    In this work the quantum theory of two dimensional dilaton black holes is studied using the Wheeler De Witt equation. The solutions correspond to wave functions of the black hole. It is found that for an observer inside the horizon, there are uncertainty relations for the black hole mass and a parameter in the metric determining the Hawking flux. Only for a particular value of this parameter, can both be known with arbitrary accuracy. In the generic case there is instead a relation which is very similar to the so called string uncertainty relation.

  17. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  18. Scalarized hairy black holes

    Directory of Open Access Journals (Sweden)

    Burkhard Kleihaus

    2015-05-01

    Full Text Available In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  19. [The Instituto Oceanográfico da Universidade de São Paulo: a chapter in the emergence and firm establishment of the oceanographic sciences in Brazil, 1946-1969].

    Science.gov (United States)

    Varela, Alex Gonçalves

    2014-01-01

    Historians of science have yet to study the process by which the oceanographic sciences emerged and became firmly established in Brazil. The main goal of this article is to offer a preliminary analysis of this process by focusing on the contribution of the Instituto Paulista de Oceanografia (Paulista Institute of Oceanography), Brazil's first institution for oceanographic research; it was founded in 1946 and became part of the University of São Paulo in 1951, at which time it was renamed the Instituto Oceanográfico da Universidade de São Paulo (Oceanographic Institute of the University of São Paulo). The analysis centers on the role of three scientists who were on the facility's early research staff: Wladimir Besnard, Ingvar Emilsson, and Marta Vannucci.

  20. National Oceanographic Fleet Operating Schedules for 1983.

    Science.gov (United States)

    1983-01-01

    187 DAVID STARR JORDAN .................................................. 188 MCARTHUR...8217TLANT9 S!A OCEAN A C A 141I A4 ALF3fTQC% IV ALPUA HELIX A%TFLCPF* ATLRTIS H 1 * atLUE FINJ CApr rLCPIL’ CAPr HATTERAS* CAPr I’ENLOPIN It * DAVID STAPP...ALBATROSS IV LAST CHANGED 15 OCT 82 OPS SCHEDULE FOR PERIOD 01 JAN 83 THRU 31 DEC F3 N4FS NOIA DEP: 22 FEB S3 WOODS HOLE MACKEREL ACOUSTICSARR: 04

  1. Black Hole Shadows of Charged Spinning Black Holes

    OpenAIRE

    Takahashi, Rohta

    2005-01-01

    We propose a method for measuring the black hole charge by imaging a black hole shadow in a galactic center by future interferometers. Even when the black hole is uncharged, it is possible to confirm the charge neutrality by this method. We first derive the analytic formulae of the black hole shadow in an optically thin medium around a charged spinning black hole, and then investigate how contours of the black hole shadow depend on the spin and the charge of the black hole for several inclina...

  2. Black holes with halos

    Science.gov (United States)

    Monten, Ruben; Toldo, Chiara

    2018-02-01

    We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

  3. Blue Holes & Hurricanes

    National Research Council Canada - National Science Library

    David Levin

    2017-01-01

    A blue hole in the ocean is a striking sight. Fly over remote areas of the Caribbean Sea and you'll see shallow turquoise water stretching for miles, interrupted only by occasional sand bars and coral reefs...

  4. Illuminating black holes

    Science.gov (United States)

    Barr, Ian A.; Bull, Anne; O'Brien, Eileen; Drillsma-Milgrom, Katy A.; Milgrom, Lionel R.

    2016-07-01

    Two-dimensional shadows formed by illuminating vortices are shown to be visually analogous to the gravitational action of black holes on light and surrounding matter. They could be useful teaching aids demonstrating some of the consequences of general relativity.

  5. Nonsingular black hole

    Science.gov (United States)

    Chamseddine, Ali H.; Mukhanov, Viatcheslav

    2017-03-01

    We consider the Schwarzschild black hole and show how, in a theory with limiting curvature, the physical singularity "inside it" is removed. The resulting spacetime is geodesically complete. The internal structure of this nonsingular black hole is analogous to Russian nesting dolls. Namely, after falling into the black hole of radius rg, an observer, instead of being destroyed at the singularity, gets for a short time into the region with limiting curvature. After that he re-emerges in the near horizon region of a spacetime described by the Schwarzschild metric of a gravitational radius proportional to rg^{1/3}. In the next cycle, after passing the limiting curvature, the observer finds himself within a black hole of even smaller radius proportional to rg^{1/9}, and so on. Finally after a few cycles he will end up in the spacetime where he remains forever at limiting curvature.

  6. Black hole quantum spectrum

    National Research Council Canada - National Science Library

    Corda, Christian

    2013-01-01

    Introducing a black hole (BH) effective temperature, which takes into account both the non-strictly thermal character of Hawking radiation and the countable behavior of emissions of subsequent Hawking quanta, we recently re...

  7. Holographic black hole chemistry

    National Research Council Canada - National Science Library

    Karch, Andreas; Robinson, Brandon

    2015-01-01

    Thermodynamic quantities associated with black holes in Anti-de Sitter space obey an interesting identity when the cosmological constant is included as one of the dynamical variables, the generalized Smarr relation...

  8. RIMPAC 08: Naval Oceanographic Office glider operations

    Science.gov (United States)

    Mahoney, Kevin L.; Grembowicz, Ken; Bricker, Bruce; Crossland, Steve; Bryant, Danielle; Torres, Marc; Giddings, Tom

    2009-05-01

    The Naval Oceanographic Office (NAVOCEANO) Glider Operations Center (GOC) supported its first joint-mission exercise during Rim of the Pacific (RIMPAC) 08, a multi-national naval exercise conducted during July 2008 near the Hawaiian Islands. NAVOCEANO personnel deployed four Seagliders from USNS SUMNER for Anti-submarine Warfare (ASW) operations and four Slocum gliders for Mine Warfare (MIW) operations. Each Seaglider was equipped with a Sea-Bird Electronics (SBE) 41cp CTD and Wet Labs, Inc. bb2fl ECO-puck optical sensor. The instrumentation suite on the Slocum gliders varied, but each Slocum glider had an SBE 41cp CTD combined with one of the following optical sensors: a Wet Labs, Inc. AUVb scattering sensor, a Wet Labs, Inc. bb3slo ECO-puck backscattering sensor, or a Satlantic, Inc. OCR radiometer. Using Iridium communications, the GOC had command and control of all eight gliders, with Department of Defense (DoD) personnel and DoD contractors serving as glider pilots. Raw glider data were transmitted each time a glider surfaced, and the subsequent data flow included processing, quality-control procedures, and the generation of operational and tactical products. The raw glider data were also sent to the Naval Research Laboratory at Stennis Space Center (NRLSSC) for fusion with satellite data and modeled data (currents, tides, etc.) to create optical forecasting, optical volume, and electro-optical identification (EOID) performance surface products. The glider-based products were delivered to the ASW and MIW Reach Back Cells for incorporation into METOC products and for dissemination to the Fleet. Based on the metrics presented in this paper, the inaugural joint-mission operation was a success.

  9. Charged Galileon black holes

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, Eugeny; Charmousis, Christos [Laboratoire de Physique Théorique (LPT), Univ. Paris-Sud, CNRS UMR 8627, F-91405 Orsay (France); Hassaine, Mokhtar, E-mail: eugeny.babichev@th.u-psud.fr, E-mail: christos.charmousis@th.u-psud.fr, E-mail: hassaine@inst-mat.utalca.cl [Instituto de Matemática y Física, Universidad de Talca, Casilla 747, Talca (Chile)

    2015-05-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.

  10. World War II (1939-1945 Oceanographic Observations

    Directory of Open Access Journals (Sweden)

    S Levitus

    2013-09-01

    Full Text Available We document the geographical and temporal distributions of oceanographic vertical profile observations made during World War II (1939-1945 that are included in the " World Ocean Database " (WOD. The WOD is a product of the NOAA/National Oceanographic Data Center, USA and its co-located ICSU World Data Center for Oceanography. The WOD is the largest collection of ocean profile data available internationally without restriction. All data shown in this paper are available online without restriction and at no cost. The WOD is built upon the international exchange of oceanographic data with contributions of data received from many countries. Most of the data shown in this paper and the data within the WOD in which these data reside in a uniform format were gathered under the auspices of the International Oceanographic Data and Information Exchange (IODE committee of the Intergovernmental Oceanographic Commission (IOC of UNESCO and the ICSU (International Council of Science World Data Center system, which is now part of the ICSU World Data System. The WOD contains 112,714 ocean station data casts and 45,003 mechanical bathythermograph profiles for 1939-1945

  11. The Thermodynamics of Black Holes

    Directory of Open Access Journals (Sweden)

    Wald Robert M.

    2001-01-01

    Full Text Available We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  12. An Oceanographic Decision Support System for Scientific Field Experiments

    Science.gov (United States)

    Maughan, T.; Das, J.; McCann, M. P.; Rajan, K.

    2011-12-01

    Thom Maughan, Jnaneshwar Das, Mike McCann, Danelle Cline, Mike Godin, Fred Bahr, Kevin Gomes, Tom O'Reilly, Frederic Py, Monique Messie, John Ryan, Francisco Chavez, Jim Bellingham, Maria Fox, Kanna Rajan Monterey Bay Aquarium Research Institute Moss Lading, California, United States Many of the coastal ocean processes we wish to observe in order to characterize marine ecosystems have large spatial extant (tens of square km) and are dynamic moving kilometers in a day with biological processes spanning anywhere from minutes to days. Some like harmful algal blooms generate toxins which can significantly impact human health and coastal economies. In order to obtain a viable understanding of the biogeochemical processes which define their dynamics and ecology, it is necessary to persistently observe, track and sample within and near the dynamic fields using augmented methods of observation such as autonomous platforms like AUVs, gliders and surface craft. Field experiments to plan, execute and manage such multitude of assets are challenging. To alleviate this problem the autonomous systems group with its collaborators at MBARI and USC designed, built and fielded a prototype Oceanographic Decision Support System (ODSS) that provides situational awareness and a single portal to visualize and plan deployments for the large scale October 2010 CANON field program as well as a series of 2 week field programs in 2011. The field programs were conducted in Monterey Bay, a known 'red tide' incubator, and varied from as many as twenty autonomous platforms, four ships and 2 manned airplanes to coordinated AUV operations, drifters and a single ship. The ODSS web-based portal was used to assimilate information from a collection of sources at sea, including AUVs, moorings, radar data as well as remote sensing products generated by partner organizations to provide a synthesis of views useful to predict the movement of a chlorophyll patch in the confines of the northern Monterey Bay

  13. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  14. ICON - Media Luna Reef 2011 Meteorological and Oceanographic Observations (NODC Accession 0098078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  15. ICON - West Fore Reef, Discovery Bay, Jamaica 2008 Meteorological and Oceanographic Observations (NODC Accession 0054499)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  16. ICON - Salt River Bay 2007 Meteorological and Oceanographic Observations (NODC Accession 0049438)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  17. ICON - Media Luna Reef 2013 Meteorological and Oceanographic Observations (NODC Accession 0124000)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  18. ICON - Buccoo Reef 2013 Meteorological and Oceanographic Observations (NODC Accession 0123996)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  19. ICON - Little Cayman 2013 Meteorological and Oceanographic Observations (NODC Accession 0123997)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  20. ICON - Lao Lao Bay 2014 Meteorological and Oceanographic Observations (NCEI Accession 0137094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  1. ICON - Buccoo Reef 2014 Meteorological and Oceanographic Observations (NCEI Accession 0137094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  2. ICON - Salt River Bay 2014 Meteorological and Oceanographic Observations (NCEI Accession 0137094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  3. ICON - Molasses Reef (secondary) 2012 Meteorological and Oceanographic Observations (NODC Accession 0117728)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  4. ICON - Media Luna Reef 2008 Meteorological and Oceanographic Observations (NODC Accession 0039700)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  5. ICON - North Norman's Patch Reef 2007 Meteorological and Oceanographic Observations (NODC Accession 0049875)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  6. ICON - Lao Lao Bay 2013 Meteorological and Oceanographic Observations (NODC Accession 0123998)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  7. ICON - Media Luna Reef 2006 Meteorological and Oceanographic Observations (NODC Accession 0049876)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  8. ICON - Media Luna Reef 2007 Meteorological and Oceanographic Observations (NODC Accession 0049877)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  9. ICON - Salt River Bay 2013 Meteorological and Oceanographic Observations (NODC Accession 0124001)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  10. ICON - Salt River Bay 2011 Meteorological and Oceanographic Observations (NODC Accession 0098077)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  11. ICON - Angel's Reef 2013 Meteorological and Oceanographic Observations (NODC Accession 0123995)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  12. ICON - Salt River Bay 2006 Meteorological and Oceanographic Observations (NODC Accession 0049446)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  13. ICON - Buccoo Reef 2015 Meteorological and Oceanographic Observations (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  14. ICON - Little Cayman 2015 Meteorological and Oceanographic Observations (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  15. ICON - Lao Lao Bay, Saipan 2011 Meteorological and Oceanographic Observations (NODC Accession 0098076)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  16. ICON - Little Cayman 2012 Meteorological and Oceanographic Observations (NODC Accession 0117730)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  17. ICON - Catuan Wreck 2015 Meteorological and Oceanographic Observations (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  18. ICON - Lao Lao Bay 2012 Meteorological and Oceanographic Observations (NODC Accession 0117721)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  19. ICON - Molasses Reef (secondary) 2013 Meteorological and Oceanographic Observations (NODC Accession 0123999)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  20. ICON - Puerto Plata 2015 Meteorological and Oceanographic Observations (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  1. ICON - Angel's Reef 2014 Meteorological and Oceanographic Observations (NCEI Accession 0137094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  2. ICON - Media Luna Reef 2012 Meteorological and Oceanographic Observations (NODC Accession 0117729)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  3. ICON - Angel's Reef 2015 Meteorological and Oceanographic Observations (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  4. ICON - Little Cayman, Cayman Islands 2011 Meteorological and Oceanographic Observations (NODC Accession 0098079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  5. ICON - Salt River Bay 2012 Meteorological and Oceanographic Observations (NODC Accession 0117726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  6. ICON - Salt River Bay 2008 Meteorological and Oceanographic Observations (NODC Accession 0057130)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  7. ICON - West Fore Reef, Discovery Bay, Jamaica 2007 Meteorological and Oceanographic Observations (NODC Accession 0054497)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  8. ICON - Little Cayman 2014 Meteorological and Oceanographic Observations (NCEI Accession 0137094)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  9. ICON - North Norman's Patch Reef 2003 Meteorological and Oceanographic Observations (CMRC2) (NODC Accession 0049873)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  10. ICON - North Norman's Patch Reef 2006 Meteorological and Oceanographic Observations (NODC Accession 0049874)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  11. Oceanographic cruise Indian Ocean and Java Trench June 1969 (NODC Accession 7100908)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard H.M.A.S DIAMANTINA during an oceanographic cruise in the Java Trench and the Indian Ocean during...

  12. Oceanographic cruise: Coral Sea, Arafura Sea, and Java Trench, April - May 1969 (NODC Accession 7100914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard HMAS DIAMANTINA during an oceanographic cruise in the Coral Sea, Arafura Sea, and Java Trench...

  13. SOCIB applications for oceanographic data management

    Science.gov (United States)

    Troupin, Charles; Pau Beltran, Joan; Frontera, Biel; Gómara, Sonia; Lora, Sebastian; March, David; Sebastian, Kristian; Tintoré, Joaquin

    2015-04-01

    The Balearic Islands Coastal Ocean Observing and Forecasting System (SOCIB, http://www.socib.es), is a multi-platform Marine Research Infrastructure that provides free, open and quality-controlled data from near-shore to the open sea. To collect the necessary data, the SOCIB system is made up of: a research vessel, a high-frequency (HF) radar system, weather stations, tide gauges, moorings, drifting buoys, ARGO profilers, and gliders (autonomous underwater vehicles). In addition, the system has recently begun incorporating oceanographic sensors attached to sea turtles. High-resolution numerical models provide forecast for hydrodynamics (ROMS) and waves (SAPO). According to SOCIB principles, data have to be: discoverable and accessible; freely available; interoperable, quality-controlled and standardized. The Data Centre (DC) manages the different steps of data processing, including: acquisition using SOCIB platforms (gliders, drifters, HF radar, ...), numerical models (hydrodynamics, waves, ...) or information generated by other data sources, distribution through dedicated web and mobile applications dynamic visualisation. The SOCIB DC constitutes an example of marine information systems within the framework of new coastal ocean observatories. In this work we present some of the applications developed for specific type of users, as well as the technologies used for their implementation: DAPP (Deployments application, http://apps.socib.es/dapp/), a web application to display information related to mobile platform trajectories. LW4NC2 (http://thredds.socib.es/lw4nc2), a web application for multidimensional (grid) data from NetCDF files (numerical models, HF radar). SACOSTA (http://gis.socib.es/sacosta), a viewer for cartographic data such as environmental sensitivity of the coastline. SEABOARD (http://seaboard.socib.es), a tool to disseminate SOCIB real time data to different types of users. Smart-phone apps to access data, platform trajectories and forecasts in real

  14. Microstate solutions from black hole deconstruction

    Czech Academy of Sciences Publication Activity Database

    Raeymaekers, Joris; Van den Bleeken, D.

    2015-01-01

    Roč. 2015, č. 12 (2015), s. 095 ISSN 1029-8479 R&D Projects: GA ČR(CZ) GA14-31689S Grant - others:AV ČR(CZ) TUB-14-03 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : back hole s in string theory * AdS-CFT correspondence * D-branes * M-theory Subject RIV: BE - Theoretical Physics Impact factor: 6.023, year: 2015

  15. Organization of an Oceanographic Data Bank for the Peruvian Navy.

    Science.gov (United States)

    1981-09-01

    AD-AI14 548 NAVAL POSTGRADUATE SCHOOL MONTEREY CA F/B 8/3 ORGANIZATION OF AN OCEANOGRAPHIC DATA BANK FOR THE PERUVIAN NAV--ETC(U) SEP 81 H S SOLDI...were used to obtain monthly graphs of sound speed profiles. These profiles were grouped by quarters: Jan-Mar, Apr-Jun, Jul- Sep and Oct-Dec. They were...Oceanographic Station Data, Informal Report #67-X NAVOCEANO. Zarate, A., 1555: Historia del Descubrimiento y Conquista del Peru, con las Cosas Naturales que

  16. A New Meteo-oceanographic and Environmental Monitoring Laboratory in Brazil

    Science.gov (United States)

    Fontes, Roberto F. C.; Dottori, Marcelo; Silveira, Ilson C. A.; Castro, Belmiro M.

    2013-04-01

    The newer oil provinces in the pre-salt regions off the Brazilian Coast have raised the necessity of the creation of monitoring and observational centers, regarding the best comprehension on the ocean and atmosphere dynamics. The relation between industry and university is a concept based on collaboration, and it is an innovative social experiment in Brazil. The sustainability of that collaboration depends on the balance of mutual interests on private business and public academic institutions. The entrepreneur needs continuous accesses to the new academic researches, and the greatest benefit, for the academy, are funding complementation and personnel qualification. We need to establish a thread of new challenges, some of them based on disruption of paradigms in the Brazilian academic culture, and removal of obstructive clauses from the entrepreneur. Questioning and methods revalidation, in the oceanic environment areas, also requires a collaborative and interdisciplinary effort, congregating the physical aspects along with others compartments of the environmental monitoring. We proposed the creation of a Meteo-oceanographic and Environmental Monitoring Laboratory - LAMMOA (Portuguese acronym), which will be installed in a new facility funded by PETROBRAS (the Brazilian leading oil company) and ruled by USP, UNESP and UNICAMP, the state public universities in Santos (São Paulo State, Brazil). The new facility will be a research center in oil and gas activities, named CENPEG-BS (Portuguese acronym for Research Center of Oil and Gas in the Bay of Santos). Several laboratories and groups will work together, in a highly collaborative environment and so, capable of quickly respond to sudden demands on offshore activities and logistic operations, as well as in contingency situations. LAMMOA will continuous monitor oceanic regions where the pre-salt activities of oil exploitation occur. It will monitor meteo-oceanographic parameters like winds, waves and currents

  17. Merging Black Holes

    Science.gov (United States)

    Centrella, John

    2009-01-01

    The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GEO600, as well as the space-based LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

  18. Black hole gravitohydromagnetics

    CERN Document Server

    Punsly, Brian

    2008-01-01

    Black hole gravitohydromagnetics (GHM) is developed from the rudiments to the frontiers of research in this book. GHM describes plasma interactions that combine the effects of gravity and a strong magnetic field, in the vicinity (ergosphere) of a rapidly rotating black hole. This topic was created in response to the astrophysical quest to understand the central engines of radio loud extragalactic radio sources. The theory describes a "torsional tug of war" between rotating ergospheric plasma and the distant asymptotic plasma that extracts the rotational inertia of the black hole. The recoil from the struggle between electromagnetic and gravitational forces near the event horizon is manifested as a powerful pair of magnetized particle beams (jets) that are ejected at nearly the speed of light. These bipolar jets feed large-scale magnetized plasmoids on scales as large as millions of light years (the radio lobes of extragalactic radio sources). This interaction can initiate jets that transport energy fluxes exc...

  19. Merging Black Holes

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  20. Black-hole astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  1. Ozone Hole Over Antarctica

    Science.gov (United States)

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  2. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  3. Braneless Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Rajaraman, Arvind

    2003-06-02

    It is known that the naive version of D-brane theory is inadequate to explain the black hole entropy in the limit in which the Schwarzschild radius becomes larger than all compactification radii. We present evidence that a more consistent description can be given in terms of strings with rescaled tensions. We show that the rescaling can be interpreted as a redshift of the tension of a fundamental string in the gravitational field of the black hole. An interesting connection is found between the string level number and the Rindler energy. Using this connection, we reproduce the entropies of Schwarzschild black holes in arbitrary dimensions in terms of the entropy of a single string at the Hagedorn temperature.

  4. Oceanographic Research Towers in European Waters

    Science.gov (United States)

    1992-12-01

    16m Administration, Persons or Contact, and Access Administration * Istituto (formerly Laboratorio) per lo Studio della Dinamica delle Grandi Masse...also written Istituto Studio Dinamica Grandi Masse (ISDGM)], San Polo 1364, 1-30125 Venezia, Italy Persons of Contact Director of the Institute * Dr

  5. Characterizing Black Hole Mergers

    Science.gov (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard

    2010-01-01

    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  6. Magnonic Black Holes

    Science.gov (United States)

    Roldán-Molina, A.; Nunez, Alvaro S.; Duine, R. A.

    2017-02-01

    We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons—the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.

  7. Superfluid Black Holes.

    Science.gov (United States)

    Hennigar, Robie A; Mann, Robert B; Tjoa, Erickson

    2017-01-13

    We present what we believe is the first example of a "λ-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid ^{4}He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically anti-de Sitter hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  8. Magnonic Black Holes.

    Science.gov (United States)

    Roldán-Molina, A; Nunez, Alvaro S; Duine, R A

    2017-02-10

    We show that the interaction between the spin-polarized current and the magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons-the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.

  9. Are Black Holes Springy?

    CERN Document Server

    Good, Michael R R

    2014-01-01

    A $(3+1)$-dimensional asymptotically flat Kerr black hole angular speed $\\Omega_+$ can be used to define an effective spring constant, $k=m\\Omega_+^2$. Its maximum value is the Schwarzschild surface gravity, $k = \\kappa $, which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: $2\\pi T = \\kappa - k$. Hooke's law, in the extremal limit, provides the force $F = 1/4$, which is consistent with the conjecture of maximum force in general relativity.

  10. Publication Of Oceanographic Data on CD-ROM

    Science.gov (United States)

    Hilland, Jeffrey E.; Smith, Elizabeth A.; Martin, Michael D.

    1992-01-01

    Large collections of oceanographic data and other large collections of data published on CD-ROM's in formats facilitating access and analysis. Involves four major steps: preprocessing, premastering, mastering, and verification. Large capacity, small size, commercial availability, long-life, and standard format of CD-ROM's offer advantages over computer-compatible magnetic tape.

  11. Web catalog of oceanographic data using GeoNetwork

    Science.gov (United States)

    Marinova, Veselka; Stefanov, Asen

    2017-04-01

    Most of the data collected, analyzed and used by Bulgarian oceanographic data center (BgODC) from scientific cruises, argo floats, ferry boxes and real time operating systems are spatially oriented and need to be displayed on the map. The challenge is to make spatial information more accessible to users, decision makers and scientists. In order to meet this challenge, BgODC concentrate its efforts on improving dynamic and standardized access to their geospatial data as well as those from various related organizations and institutions. BgODC currently is implementing a project to create a geospatial portal for distributing metadata and search, exchange and harvesting spatial data. There are many open source software solutions able to create such spatial data infrastructure (SDI). Finally, the GeoNetwork open source is chosen, as it is already widespread. This software is free, effective and "cheap" solution for implementing SDI at organization level. It is platform independent and runs under many operating systems. Filling of the catalog goes through these practical steps: • Managing and storing data reliably within MS SQL spatial data base; • Registration of maps and data of various formats and sources in GeoServer (most popular open source geospatial server embedded with GeoNetwork) ; • Filling added meta data and publishing geospatial data at the desktop of GeoNetwork. GeoServer and GeoNetwork are based on Java so they require installing of a servlet engine like Tomcat. The experience gained from the use of GeoNetwork Open Source confirms that the catalog meets the requirements for data management and is flexible enough to customize. Building the catalog facilitates sustainable data exchange between end users. The catalog is a big step towards implementation of the INSPIRE directive due to availability of many features necessary for producing "INSPIRE compliant" metadata records. The catalog now contains all available GIS data provided by BgODC for Internet

  12. Almost BPS black holes

    NARCIS (Netherlands)

    Goldstein, K.D.|info:eu-repo/dai/nl/314132376; Katmadas, S.

    2009-01-01

    We study non-BPS black hole solutions to ungauged supergravity with 8 supercharges coupled to vector multiplets in four and five dimensions. We identify a large class of five dimensional non-BPS solutions, which we call ``almost BPS'', that are supersymmetric on local patches and satisfy a first

  13. Nonsingular black hole

    Energy Technology Data Exchange (ETDEWEB)

    Chamseddine, Ali H. [American University of Beirut, Physics Department, Beirut (Lebanon); I.H.E.S., Bures-sur-Yvette (France); Mukhanov, Viatcheslav [Niels Bohr Institute, Niels Bohr International Academy, Copenhagen (Denmark); Ludwig-Maximilians University, Theoretical Physics, Munich (Germany); MPI for Physics, Munich (Germany)

    2017-03-15

    We consider the Schwarzschild black hole and show how, in a theory with limiting curvature, the physical singularity ''inside it'' is removed. The resulting spacetime is geodesically complete. The internal structure of this nonsingular black hole is analogous to Russian nesting dolls. Namely, after falling into the black hole of radius r{sub g}, an observer, instead of being destroyed at the singularity, gets for a short time into the region with limiting curvature. After that he re-emerges in the near horizon region of a spacetime described by the Schwarzschild metric of a gravitational radius proportional to r{sub g}{sup 1/3}. In the next cycle, after passing the limiting curvature, the observer finds himself within a black hole of even smaller radius proportional to r{sub g}{sup 1/9}, and so on. Finally after a few cycles he will end up in the spacetime where he remains forever at limiting curvature. (orig.)

  14. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  15. "Holes": Folklore Redux.

    Science.gov (United States)

    Mascia, Elizabeth G.

    2001-01-01

    Demonstrates that a careful reading of the book for young adults, "Holes" by Louis Sachar, reveals how this contemporary story is grounded in folklore, and that it is this debt to folk literature that allows readers to accept an improbable plot. Shows how the story weaves together elements from traditional folk literature and stretches them across…

  16. The Antarctic Ozone Hole.

    Science.gov (United States)

    Stolarski, Richard S.

    1988-01-01

    Discusses the Airborne Antarctic Ozone Experiment (1987) and the findings of the British Antarctic Survey (1985). Proposes two theories for the appearance of the hole in the ozone layer over Antarctica which appears each spring; air pollution and natural atmospheric shifts. Illustrates the mechanics of both. Supports worldwide chlorofluorocarbon…

  17. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  18. Black Hole: The Interior Spacetime

    CERN Document Server

    Ong, Yen Chin

    2016-01-01

    The information loss paradox is often discussed from the perspective of the observers who stay outside of a black hole. However, the interior spacetime of a black hole can be rather nontrivial. We discuss the open problems regarding the volume of a black hole, and whether it plays any role in information storage. We also emphasize the importance of resolving the black hole singularity, if one were to resolve the information loss paradox.

  19. String physics and black holes

    Energy Technology Data Exchange (ETDEWEB)

    Susskind, L. [Stanford Univ., CA (United States). Dept. of Physics; Uglum, J. [Stanford Univ., CA (United States). Dept. of Physics

    1996-02-01

    In these lectures we review the quantum physics of large Schwarzschild black holes. Hawking`s information paradox, the theory of the stretched horizon and the principle of black hole complementarity are covered. We then discuss how the ideas of black hole complementarity may be realized in string theory. Finally, arguments are given that the world may be a hologram. (orig.).

  20. Orbital, tectonic and oceanographic controls on Pliocene climate and atmospheric circulation in Arctic Norway

    Science.gov (United States)

    Panitz, Sina; Salzmann, Ulrich; Risebrobakken, Bjørg; De Schepper, Stijn; Pound, Matthew J.; Haywood, Alan M.; Dolan, Aisling M.; Lunt, Daniel J.

    2018-02-01

    During the Pliocene Epoch, a stronger-than-present overturning circulation has been invoked to explain the enhanced warming in the Nordic Seas region in comparison to low to mid-latitude regions. While marine records are indicative of changes in the northward heat transport via the North Atlantic Current (NAC) during the Pliocene, the long-term terrestrial climate evolution and its driving mechanisms are poorly understood. We present the first two-million-year-long Pliocene pollen record for the Nordic Seas region from Ocean Drilling Program (ODP) Hole 642B, reflecting vegetation and climate in Arctic Norway, to assess the influence of oceanographic and atmospheric controls on Pliocene climate evolution. The vegetation record reveals a long-term cooling trend in northern Norway, which might be linked to a general decline in atmospheric CO2 concentrations over the studied interval, and climate oscillations primarily controlled by precession (23 kyr), obliquity (54 kyr) and eccentricity (100 kyr) forcing. In addition, the record identifies four major shifts in Pliocene vegetation and climate mainly controlled by changes in northward heat transport via the NAC. Cool temperate (warmer than present) conditions prevailed between 5.03-4.30 Ma, 3.90-3.47 Ma and 3.29-3.16 Ma and boreal (similar to present) conditions predominated between 4.30-3.90 Ma, 3.47-3.29 and after 3.16 Ma. A distinct decline in sediment and pollen accumulation rates at c. 4.65 Ma is probably linked to changes in ocean currents, marine productivity and atmospheric circulation. Climate model simulations suggest that changes in the strength of the Atlantic Meridional Overturning Circulation during the Early Pliocene could have affected atmospheric circulation in the Nordic Seas region, which would have affected the direction of pollen transport from Scandinavia to ODP Hole 642B.

  1. Hole pairs in a spin liquid: Influence of electrostatic hole-hole repulsion

    Science.gov (United States)

    Gazza, Claudio; Martins, George B.; Riera, José; Dagotto, Elbio

    1999-01-01

    The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to 2×30 sites. For a nearest-neighbor (NN) hole-hole repulsion, the two-holes bound state is surprisingly robust and breaks only when the repulsion is several times the exchange J. At ~10% hole doping the pairs break only for a NN repulsion as large as V~4J. Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper oxides is remarked.

  2. Interdisciplinary oceanographic observations: the wave of the future

    Directory of Open Access Journals (Sweden)

    Tommy D. Dickey

    2005-06-01

    Full Text Available Oceanographic measurements, though difficult and expensive, are essential for effective study, stewardship, preservation, and management of our oceanic and atmospheric systems. Ocean sciences have been driven by technologiesenabling new observations, discoveries, and modelling of diverse interdisciplinary phenomena. Despite rapid advances inocean sampling capabilities, the numbers of disciplinary variables that are necessary to solve oceanographic problems arelarge and increasing. In addition, the time and space scales of key processes span over ten orders of magnitude; presently, there remain major spectral gaps in our sampling. Thus, undersampling presents the main limitation to our understanding of global climate change; variability in fish biomass and regime shifts; and episodic and extreme events. Fortunately, recentadvances in ocean platforms and in situ autonomous sampling systems and satellite sensors are enabling unprecedented rates of data acquisition as well as the expansion of temporal and spatial coverage. Consequently, improved sampling strategies will lead to a reduction in ocean forecasting error for predictions of a multitude of atmospheric and oceanic processes. Nonetheless, major challenges remain to massively increase the variety and quantity of ocean measurements and to effectively coordinate, synthesize, and distribute oceanographic data sets. In particular, numbers of measurements are limited by the costs of instruments and their deployment as well as data processing and production of useful data products and visualizations. Looking forward, many novel and innovative technologies involving computing, nanotechnology, robotics, information and telemetry technologies, space sciences, and molecular biology are being developed at a fast pace for numerous applications (Kaku, 1997; Kurzweil, 1999. It is anticipated that several of these can and will be transitioned to the ocean sciences and will prove to be extremely beneficial

  3. Nonsingular Black Holes

    CERN Document Server

    Olmo, Gonzalo J

    2011-01-01

    We find that if general relativity is modified at the Planck scale by a Ricci-squared term, electrically charged black holes may be nonsingular. These objects concentrate their mass in a microscopic sphere of radius $r_{core}\\approx N_q^{1/2}l_P/3$, where $l_P$ is the Planck length and $N_q$ is the number of electric charges. The singularity is avoided if the mass of the object satisfies the condition $M_0^2\\approx m_P^2 \\alpha_{em}^{3/2} N_q^3/2$, where $m_P$ is the Planck mass and $\\alpha_{em}$ is the fine-structure constant. For astrophysical black holes this amount of charge is so small that their external horizon almost coincides with their Schwarzschild radius. We work within a first-order (Palatini) approach.

  4. Prisons of light : black holes

    Science.gov (United States)

    Ferguson, Kitty

    What is a black hole? Could we survive a visit to one -- perhaps even venture inside? Have we yet discovered any real black holes? And what do black holes teach us about the mysteries of our Universe? These are just a few of the tantalizing questions examined in this tour-de-force, jargon-free review of one of the most fascinating topics in modern science. In search of the answers, we trace a star from its birth to its death throes, take a hypothetical journey to the border of a black hole and beyond, spend time with some of the world's leading theoretical physicists and astronomers, and take a whimsical look at some of the wild ideas black holes have inspired. Prisons of Light - Black Holes is comprehensive and detailed. Yet Kitty Ferguson's lightness of touch and down-to-earth analogies set this book apart from all others on black holes and make it a wonderfully stimulating and entertaining read.

  5. Turbulent and Transitional Modeling of Drag on Oceanographic Measurement Devices

    Directory of Open Access Journals (Sweden)

    J. P. Abraham

    2012-01-01

    Full Text Available Computational fluid dynamic techniques have been applied to the determination of drag on oceanographic devices (expendable bathythermographs. Such devices, which are used to monitor changes in ocean heat content, provide information that is dependent on their drag coefficient. Inaccuracies in drag calculations can impact the estimation of ocean heating associated with global warming. Traditionally, ocean-heating information was based on experimental correlations which related the depth of the device to the fall time. The relation of time-depth is provided by a fall-rate equation (FRE. It is known that FRE depths are reasonably accurate for ocean environments that match the experiments from which the correlations were developed. For other situations, use of the FRE may lead to depth errors that preclude XBTs as accurate oceanographic devices. Here, a CFD approach has been taken which provides drag coefficients that are used to predict depths independent of an FRE.

  6. Exploiting the Capabilities of NASA's Giovanni System for Oceanographic Education

    Science.gov (United States)

    Acker, James G.; Petrucio, Emil; Leptoukh, Gregory; Shen, Suhung

    2007-01-01

    The NASA Goddard Earth Science Data and Information Services Center (GES DISC) Giovanni system [GES DISC Interactive Online Visualization ANd aNalysis Infrastructure] has significant capabilities for oceanographic education and independent research utilizing ocean color radiometry data products. Giovanni allows Web-based data discovery and basic analyses, and can be used both for guided illustration of a variety of marine processes and phenomena, and for independent research investigations. Giovanni's capabilities are particularly suited for advanced secondary school science and undergraduate (college) education. This presentation will describe a variety of ways that Giovanni can be used for oceanographic education. Auxiliary information resources that can be utilized will also be described. Several testimonies of Giovanni usage for instruction will be provided, and a recent case history of Giovanni utilization for instruction and research at the undergraduate level is highlighted.

  7. University of the seas, 15 years of oceanographic schools on board of the Marion Dufresne

    Science.gov (United States)

    Malaize, Bruno; Deverchere, Jacques; Leau, Hélène; Graindorge, David

    2015-04-01

    Since the first University at Sea, proposed by two French Universities (Brest and Bordeaux) in 1999, the R/V Marion Dufresne, in collaboration with the French Polar institute (IPEV), has welcome 12 oceanographic schools. The main objective of this educational and scientific program is to stimulate the potential interest of highly graduated students in scientific fields dealing with oceanography, and to broaden exchanges with foreign universities, strengthening a pool of excellence at a high international scientific level. It is a unique opportunity for the students to discover and to be involved in the work in progress of collecting scientific data on board of a ship, and to attend international research courses given by scientists involved in the cruise program. They also experience the final task of the scientific work by presenting their own training results, making posters on board, and writing a cruise report. For some University at Sea, students had also updated a daily journal, available on internet, hosted by the main institutions involved (as IPEV or EPOC, Bordeaux University). All this work is done in English, a common language to all the participants. An overview of these 15 years background experience will be presented, underlying the financial supports used, the logistic on board, as well as all the benefits acquiered by all former students, now in permanent positions in different international institutions.

  8. A Sensor web architecture for sharing oceanographic sensor data

    OpenAIRE

    Jirka, Simon; Toma, Daniel; Río Fernandez, Joaquín del; Delory, Eric

    2014-01-01

    This paper introduces the Sensor Web architecture of the NeXOS project as example how interoperable standards help, to facilitate the creation of an infrastructure for sharing oceanographic observation data and the integration of sensor data into applications. Important technological foundations of the NeXOS Sensor Web architecture are the concepts of spatial data infrastructures and the Sensor Web Enablement framework of the Open Geospatial Consortium. As a result an ...

  9. An Oceanographic and Climatological Atlas of Bristol Bay

    Science.gov (United States)

    1987-10-01

    have a profound the bay North Pacific water which has just entered effect on regional oceanographic phenomena. An the Bering Sea through Unimak Pass... Unimak circulation in outer Bristol Bay consists of a Island, much of the coastal current is entrained typically unclosed counterclockwise gyre open to...Peninsula and become more face currents. cyclonic and rotary offshore. National Ocean Sea level changes on either side of Unimak Survey current tables

  10. Diagnostic tools for 3D unstructured oceanographic data

    OpenAIRE

    Cotter, CJ; Gorman, GJ

    2007-01-01

    Most ocean models in current use are built upon structured meshes. It follows that most existing tools for extracting diagnostic quantities (volume and surface integrals, for example) from ocean model output are constructed using techniques and software tools which assume structured meshes. The greater complexity inherent in unstructured meshes (especially fully unstructured grids which are unstructured in the vertical as well as the horizontal direction) has left some oceanographers, accusto...

  11. WARPED DISK AROUND A BRIGHT BLACK HOLE (ARTWORK)

    Science.gov (United States)

    2002-01-01

    This diagram shows the geometry of a warped disk of dust surrounding a suspected black hole in the active galaxy NGC 6251. The diagram is based on NASA Hubble Space Telescope images of the disk which reveal that only one side reflects light emitted from a suspected black hole, hence the disk is warped. Such a warp could be due to gravitational perturbations in the galaxy's nucleus that keep the disk from being perfectly flat, or from precession of the rotation axis of the black hole relative to the rotation axis of the galaxy. Perpendicular to the disk is a jet of high-energy particles blasted into space along the black hole's spin axis. Illustration: James Gitlin (Space Telescope Science Institute)

  12. Identification of genetically and oceanographically distinct blooms of jellyfish.

    Science.gov (United States)

    Lee, Patricia L M; Dawson, Michael N; Neill, Simon P; Robins, Peter E; Houghton, Jonathan D R; Doyle, Thomas K; Hays, Graeme C

    2013-03-06

    Reports of nuisance jellyfish blooms have increased worldwide during the last half-century, but the possible causes remain unclear. A persistent difficulty lies in identifying whether blooms occur owing to local or regional processes. This issue can be resolved, in part, by establishing the geographical scales of connectivity among locations, which may be addressed using genetic analyses and oceanographic modelling. We used landscape genetics and Lagrangian modelling of oceanographic dispersal to explore patterns of connectivity in the scyphozoan jellyfish Rhizostoma octopus, which occurs en masse at locations in the Irish Sea and northeastern Atlantic. We found significant genetic structure distinguishing three populations, with both consistencies and inconsistencies with prevailing physical oceanographic patterns. Our analyses identify locations where blooms occur in apparently geographically isolated populations, locations where blooms may be the source or result of migrants, and a location where blooms do not occur consistently and jellyfish are mostly immigrant. Our interdisciplinary approach thus provides a means to ascertain the geographical origins of jellyfish in outbreaks, which may have wide utility as increased international efforts investigate jellyfish blooms.

  13. Legacy2Drupal: Conversion of an existing relational oceanographic database to a Drupal 7 CMS

    Science.gov (United States)

    Work, T. T.; Maffei, A. R.; Chandler, C. L.; Groman, R. C.

    2011-12-01

    Content Management Systems (CMSs) such as Drupal provide powerful features that can be of use to oceanographic (and other geo-science) data managers. However, in many instances, geo-science data management offices have already designed and implemented customized schemas for their metadata. The NSF funded Biological Chemical and Biological Data Management Office (BCO-DMO) has ported an existing relational database containing oceanographic metadata, along with an existing interface coded in Cold Fusion middleware, to a Drupal 7 Content Management System. This is an update on an effort described as a proof-of-concept in poster IN21B-1051, presented at AGU2009. The BCO-DMO project has translated all the existing database tables, input forms, website reports, and other features present in the existing system into Drupal CMS features. The replacement features are made possible by the use of Drupal content types, CCK node-reference fields, a custom theme, and a number of other supporting modules. This presentation describes the process used to migrate content in the original BCO-DMO metadata database to Drupal 7, some problems encountered during migration, and the modules used to migrate the content successfully. Strategic use of Drupal 7 CMS features that enable three separate but complementary interfaces to provide access to oceanographic research metadata will also be covered: 1) a Drupal 7-powered user front-end; 2) REST-ful JSON web services (providing a Mapserver interface to the metadata and data; and 3) a SPARQL interface to a semantic representation of the repository metadata (this feeding a new faceted search capability currently under development). The existing BCO-DMO ontology, developed in collaboration with Rensselaer Polytechnic Institute's Tetherless World Constellation, makes strategic use of pre-existing ontologies and will be used to drive semantically-enabled faceted search capabilities planned for the site. At this point, the use of semantic

  14. Using the STOQS Web Application for Access to in situ Oceanographic Data

    Science.gov (United States)

    McCann, M. P.

    2012-12-01

    Using the STOQS Web Application for Access to in situ Oceanographic Data Mike McCann 7 August 2012 With increasing measurement and sampling capabilities of autonomous oceanographic platforms (e.g. Gliders, Autonomous Underwater Vehicles, Wavegliders), the need to efficiently access and visualize the data they collect is growing. The Monterey Bay Aquarium Research Institute has designed and built the Spatial Temporal Oceanographic Query System (STOQS) specifically to address this issue. The need for STOQS arises from inefficiencies discovered from using CF-NetCDF point observation conventions for these data. The problem is that access efficiency decreases with decreasing dimension of CF-NetCDF data. For example, the Trajectory Common Data Model feature type has only one coordinate dimension, usually Time - positions of the trajectory (Depth, Latitude, Longitude) are stored as non-indexed record variables within the NetCDF file. If client software needs to access data between two depth values or from a bounded geographic area, then the whole data set must be read and the selection made within the client software. This is very inefficient. What is needed is a way to easily select data of interest from an archive given any number of spatial, temporal, or other constraints. Geospatial relational database technology provides this capability. The full STOQS application consists of a Postgres/PostGIS database, Mapserver, and Python-Django running on a server and Web 2.0 technology (jQuery, OpenLayers, Twitter Bootstrap) running in a modern web browser. The web application provides faceted search capabilities allowing a user to quickly drill into the data of interest. Data selection can be constrained by spatial, temporal, and depth selections as well as by parameter value and platform name. The web application layer also provides a REST (Representational State Transfer) Application Programming Interface allowing tools such as the Matlab stoqstoolbox to retrieve data

  15. Development of an Oceanographic Data Archiving and Service System for the Korean Researchers

    Science.gov (United States)

    Kim, Sung Dae; Park, Hyuk Min; Baek, Sang Ho

    2014-05-01

    Oceanographic Data and Information Center of Korea Institute of Ocean Science and Technology (KIOST) started to develop an oceanographic data archiving and service system in 2010 to support the Korean ocean researchers by providing quality controlled data continuously. Many physical oceanographic data available in the public domain and Korean domestic data were collected periodically, quality controlled, manipulated and provided to ocean modelers who need ocean data continuously and marine biologists who don't know well physical data but need it. The northern limit and the southern limit of the spatial coverage are 20°N and 55°N, and the western limit and the eastern limit are 110°E and 150°E, respectively. To archive TS (Temperature and Salinity) profile data, ARGO data were gathered from ARGO GDACs (France and USA) and many historical TS profile data observed by CTD, OSD and BT were retrieved from World Ocean Database 2009. The quality control software for TS profile data, which meets QC criteria suggested by the ARGO program and the GTSPP (Global Temperature-Salinity Profile Program), was programmed and applied to the collected data. By the end of 2013, the total number of vertical profile data from the ARGO GDACs was 59,642 and total number of station data from WOD 2009 was 1,604,422. We also collected the global satellite SST data produced by NCDC and global SSH data from AVISO every day. An automatic program was coded to collect satellite data, extract sub data sets of the North West Pacific area and produce distribution maps. The total number of collected satellite data sets was 3,613 by the end of 2013. We use 3 different data services to provide archived data to the Korean experts. A FTP service was prepared to allow data users to download data in the original format. We developed TS database system using Oracle RDBMS to contain all collected temperature salinity data and support SQL data retrieval with various conditions. The KIOST ocean data portal

  16. PRAMANA Black holes in brane worlds M s MODGIL, s PANDA and ...

    Indian Academy of Sciences (India)

    Black holes in brane worlds. M s MODGIL, s PANDA and G sENGUPTA. Department of Physics, Indian Institute of Technology, Kanpur 208 016, India. Abstract. A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane world by considering a rotating five-.

  17. Primary Black Hole Spin in OJ 287 as Determined by the General Relativity Centenary Flare

    Czech Academy of Sciences Publication Activity Database

    Valtonen, M.J.; Zola, H.; Ciprini, S.; Gopakumar, A.; Matsumoto, K.; Sadakane, K.; Kidger, M.; Gazeas, K.; Nilsson, K.; Berdyugin, A.; Hudec, René; Jelínek, Martin; Štrobl, Jan

    2016-01-01

    Roč. 819, č. 2 (2016), L37/1-L37/6 ISSN 2041-8205 Grant - others:GA ČR(CZ) GA13-33324S Institutional support: RVO:67985815 Keywords : black hole physics * quasars * supermassive black hole s Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.522, year: 2016

  18. Thermal BEC Black Holes

    Directory of Open Access Journals (Sweden)

    Roberto Casadio

    2015-10-01

    Full Text Available We review some features of Bose–Einstein condensate (BEC models of black holes obtained by means of the horizon wave function formalism. We consider the Klein–Gordon equation for a toy graviton field coupled to a static matter current in a spherically-symmetric setup. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with a continuous occupation number. An attractive self-interaction is needed for bound states to form, the case in which one finds that (approximately one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The horizon wave function formalism is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons, resulting in agreement with the semiclassical calculations and which does not hold for a single very massive particle. The spectrum of these systems has two components: a discrete ground state of energy m (the bosons forming the black hole and a continuous spectrum with energy ω > m (representing the Hawking radiation and modeled with a Planckian distribution at the expected Hawking temperature. Assuming the main effect of the internal scatterings is the Hawking radiation, the N-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy M = Nm and Entropy 2015, 17 6894 a Planckian distribution for E > M at the same Hawking temperature. This can be used to compute the partition function and to find the usual area law for the entropy, with a logarithmic correction related to the Hawking component. The backreaction of modes with ω > m is also shown to reduce

  19. stu Black Holes Unveiled

    CERN Document Server

    Bellucci, S; Marrani, A; Yeranyan, A

    2008-01-01

    The general solutions of the radial attractor flow equations for extremal black holes, both for non-BPS with non-vanishing central charge Z and for Z=0, are obtained for the so-called stu model, the minimal rank-3 N=2 symmetric supergravity in d=4 space-time dimensions. Comparisons with previous results, as well as the fake supergravity (first order) formalism and an analysis of the BPS bound all along the non-BPS attractor flows and of the marginal stability of corresponding D-brane configurations, are given.

  20. stu Black Holes Unveiled

    Science.gov (United States)

    Bellucci, Stefano; Ferrara, Sergio; Marrani, Alessio; Yeranyan, Armen

    2008-12-01

    The general solutions of the radial attractor flow equations for extremal black holes, both for non-BPS with non-vanishing central charge Z and for Z = 0, are obtained for the so-called stu model, the minimal rank-3 N = 2 symmetric supergravity in d = 4 space-time dimensions. Comparisons with previous results, as well as the fake supergravity (first order) formalism and an analysis of the BPS bound all along the non-BPS attractor flows and of the marginal stability of corresponding D-brane configurations, are given.

  1. Black hole squeezers

    Science.gov (United States)

    Su, Daiqin; Ho, C. T. Marco; Mann, Robert B.; Ralph, Timothy C.

    2017-09-01

    We show that the gravitational quasinormal modes (QNMs) of a Schwarzschild black hole play the role of a multimode squeezer that can generate particles. For a minimally coupled scalar field, the QNMs "squeeze" the initial state of the scalar field (even for the vacuum) and produce scalar particles. The maximal squeezing amplitude is inversely proportional to the cube of the imaginary part of the QNM frequency, implying that the particle generation efficiency is higher for lower decaying QNMs. Our results show that the gravitational perturbations can amplify Hawking radiation.

  2. Artificial ozone holes

    CERN Document Server

    Dolya, S N

    2014-01-01

    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

  3. Artificial black holes

    CERN Document Server

    Visser, Matt; Volovik, Grigory E

    2009-01-01

    Physicists are pondering on the possibility of simulating black holes in the laboratory by means of various "analog models". These analog models, typically based on condensed matter physics, can be used to help us understand general relativity (Einstein's gravity); conversely, abstract techniques developed in general relativity can sometimes be used to help us understand certain aspects of condensed matter physics. This book contains 13 chapters - written by experts in general relativity, particle physics, and condensed matter physics - that explore various aspects of this two-way traffic.

  4. Black holes in massive gravity

    CERN Document Server

    Babichev, Eugeny

    2015-01-01

    We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...

  5. Black Hole's 1/N Hair

    CERN Document Server

    Dvali, Gia

    2013-01-01

    According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

  6. Workshop I – Black holes and compact objects: Classical aspects

    Indian Academy of Sciences (India)

    Workshop I – Black holes and compact objects: Classical aspects. B S RAMACHANDRA and C V VISHVESHWARA. Indian Institute of Astrophysics, Bangalore 560 034, India. Email: bsr@iiap.ernet.in; vishu@iiap.ernet.in. Abstract. This is a summary of the papers presented in session W1 on the papers submitted to the.

  7. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.

    2008-09-01

    Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.

  8. Black holes and the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Garriga, Jaume [Departament de Fisica Fonamental i Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti i Franques, 1, Barcelona, 08028 Spain (Spain); Vilenkin, Alexander; Zhang, Jun, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: jun.zhang@tufts.edu [Institute of Cosmology, Tufts University, 574 Boston Ave, Medford, MA, 02155 (United States)

    2016-02-01

    Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleating during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse.

  9. Thermodynamics of Accelerating Black Holes.

    Science.gov (United States)

    Appels, Michael; Gregory, Ruth; Kubizňák, David

    2016-09-23

    We address a long-standing problem of describing the thermodynamics of an accelerating black hole. We derive a standard first law of black hole thermodynamics, with the usual identification of entropy proportional to the area of the event horizon-even though the event horizon contains a conical singularity. This result not only extends the applicability of black hole thermodynamics to realms previously not anticipated, it also opens a possibility for studying novel properties of an important class of exact radiative solutions of Einstein equations describing accelerated objects. We discuss the thermodynamic volume, stability, and phase structure of these black holes.

  10. Hole dynamics in noble metals

    OpenAIRE

    Campillo, I.; Rubio, A.; Pitarke, J. M.; Goldmann, A.; Echenique, P. M.

    2000-01-01

    We present a detailed analysis of hole dynamics in noble metals (Cu and Au), by means of first-principles many-body calculations. While holes in a free-electron gas are known to live shorter than electrons with the same excitation energy, our results indicate that d-holes in noble metals exhibit longer inelastic lifetimes than excited sp-electrons, in agreement with experiment. The density of states available for d-hole decay is larger than that for the decay of excited electrons; however, th...

  11. Design and Fabrication of Nereid-UI: A Remotely Operated Underwater Vehicle for Oceanographic Access Under Ice

    Science.gov (United States)

    Whitcomb, L. L.; Bowen, A. D.; Yoerger, D.; German, C. R.; Kinsey, J. C.; Mayer, L. A.; Jakuba, M. V.; Gomez-Ibanez, D.; Taylor, C. L.; Machado, C.; Howland, J. C.; Kaiser, C. L.; Heintz, M.; Pontbriand, C.; Suman, S.; O'hara, L.

    2013-12-01

    The Woods Hole Oceanographic Institution and collaborators from the Johns Hopkins University and the University of New Hampshire are developing for the Polar Science Community a remotely-controlled underwater robotic vehicle capable of being tele-operated under ice under remote real-time human supervision. The Nereid Under-Ice (Nereid-UI) vehicle will enable exploration and detailed examination of biological and physical environments at glacial ice-tongues and ice-shelf margins, delivering high-definition video in addition to survey data from on board acoustic, chemical, and biological sensors. Preliminary propulsion system testing indicates the vehicle will be able to attain standoff distances of up to 20 km from an ice-edge boundary, as dictated by the current maximum tether length. The goal of the Nereid-UI system is to provide scientific access to under-ice and ice-margin environments that is presently impractical or infeasible. FIBER-OPTIC TETHER: The heart of the Nereid-UI system is its expendable fiber optic telemetry system. The telemetry system utilizes many of the same components pioneered for the full-ocean depth capable HROV Nereus vehicle, with the addition of continuous fiber status monitoring, and new float-pack and depressor designs that enable single-body deployment. POWER SYSTEM: Nereid-UI is powered by a pressure-tolerant lithium-ion battery system composed of 30 Ah prismatic pouch cells, arranged on a 90 volt bus and capable of delivering 15 kW. The cells are contained in modules of 8 cells, and groups of 9 modules are housed together in oil-filled plastic boxes. The power distribution system uses pressure tolerant components extensively, each of which have been individually qualified to 10 kpsi and operation between -20 C and 40 C. THRUSTERS: Nereid-UI will employ eight identical WHOI-designed thrusters, each with a frameless motor, oil-filled and individually compensated, and designed for low-speed (500 rpm max) direct drive. We expect an end

  12. Black holes under external influence £

    Indian Academy of Sciences (India)

    KTF MFF UK

    of the flux of external fields across charged and rotating black holes which are approaching extremal states. Recently this effect has been shown to occur for black hole solutions in string theory. We also discuss black holes surrounded by rings and disks and rotating black holes accelerated by strings. Keywords. Black holes ...

  13. SeaView: bringing EarthCube to the Oceanographer

    Science.gov (United States)

    Stocks, K. I.; Diggs, S. C.; Arko, R. A.; Kinkade, D.; Shepherd, A.

    2016-12-01

    As new instrument types are developed, and new observational programs start, that support a growing community of "dry" oceanographers, the ability to find, access, and visualize existing data of interest becomes increasingly critical. Yet ocean data, when available, is are held in multiple data facilities, in different formats, and accessible through different pathways. This creates practical problems with integrating and working across different data sets. The SeaView project is building connections between the rich data resources in five major oceanographic data facilities - BCO-DMO, CCHDO, OBIS, OOI, and R2R* - creating a federated set of thematic data collections that are organized around common characteristics (geographic location, time, expedition, program, data type, etc.) and published online in Web Accessible Folders using standard file formats such as ODV and NetCDF. The work includes not simply reformatting data, but identifying and, where possible, addressing interoperability challenges: which common identifiers for core concepts can connect data across repositories, which terms a scientist may want to search that, if added to the data repositories, will increase discoverability; the presence of duplicate data across repositories, etc. We will present the data collections available to date, including data from the OOI Pioneer Array region, and seek scientists' input on the data types and formats they prefer, the tools they use to analyze and visualize data, and their specific recommendations for future data collections to support oceanographic science. * Biological and Chemical Oceanography Data Management Office (BCO-DMO), CLIVAR and Carbon Hydrographic Data Office (CCHDO), International Ocean Biogeographic Information System (iOBIS), Ocean Observatories Initiative (OOI), and Rolling Deck to Repository (R2R) Program.

  14. Oceanographic station data from bottle casts from the USS H. W. TUCKER in support of the Fleet Observations of Oceanographic Data (FLOOD) project on 01 October 1970 (NODC Accession 7100288)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the USS H. W. TUCKER in support of the Fleet Observations of Oceanographic Data (FLOOD) project. Data were collected...

  15. Black-Hole Mass Measurements

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2004-01-01

    The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized.......The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized....

  16. Black Holes in Our Universe

    Indian Academy of Sciences (India)

    Black holes are bits of space, or more precisely, 'space-time', from which even light cannot escape, because they are regions of extremely strong gravity. We now know that black holes, es- pecially those that are a million times heavier than our Sun or more, i.e., 'supermassive', are abundant in our universe, occur- ring in the ...

  17. Drilling miniature holes, Part III

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1978-07-01

    Miniature components for precision electromechanical mechanisms such as switches, timers, and actuators typically require a number of small holes. Because of the precision required, the workpiece materials, and the geometry of the parts, most of these holes must be produced by conventional drilling techniques. The use of such techniques is tedious and often requires considerable trial and error to prevent drill breakage, minimize hole mislocation and variations in hole diameter. This study of eight commercial drill designs revealed that printed circuit board drills produced better locational and size repeatability than did other drills when centerdrilling was not used. Boring holes 1 mm in dia, or less, as a general rule did not improve hole location in brass or stainless steel. Hole locations of patterns of 0.66-mm holes can be maintained within 25.4-..mu..m diametral positional tolerance if setup misalignments can be eliminated. Size tolerances of +- 3.8 ..mu..m can be maintained under some conditions when drilling flat plates. While these levels of precision are possible with existing off-the-shelf drills, they may not be practical in many cases.

  18. ATLAS simulated black hole event

    CERN Multimedia

    Pequenão, J

    2008-01-01

    The simulated collision event shown is viewed along the beampipe. The event is one in which a microscopic-black-hole was produced in the collision of two protons (not shown). The microscopic-black-hole decayed immediately into many particles. The colors of the tracks show different types of particles emerging from the collision (at the center).

  19. Asymmetric black dyonic holes

    Directory of Open Access Journals (Sweden)

    I. Cabrera-Munguia

    2015-04-01

    Full Text Available A 6-parametric asymptotically flat exact solution, describing a two-body system of asymmetric black dyons, is studied. The system consists of two unequal counterrotating Kerr–Newman black holes, endowed with electric and magnetic charges which are equal but opposite in sign, separated by a massless strut. The Smarr formula is generalized in order to take into account their contribution to the mass. The expressions for the horizon half-length parameters σ1 and σ2, as functions of the Komar parameters and of the coordinate distance, are displayed, and the thermodynamic properties of the two-body system are studied. Furthermore, the seven physical parameters satisfy a simple algebraic relation which can be understood as a dynamical scenario, in which the physical properties of one body are affected by the ones of the other body.

  20. Holocene oceanographic changes in SW Labrador Sea, off Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Pearce, Christof

    2016-01-01

    between the cold, ice-loaded Labrador Current (LC) in the north and the warm Gulf Stream (GS) waters to the south. After the Younger Dryas termination, the influence of GS-derived water increased and was further strengthened at 10.7 cal. kyr BP through enhanced northward flow of Atlantic water via...... by extensive meltwater release from ice sheets in Arctic Canada and is concurrent with a general shift in oceanographic conditions in the Labrador Sea region. Around 4.0 cal. kyr BP, conditions became more stable with a slight increase in salinity, indicating a decrease in meltwater transported via the LC...

  1. Supplemental List of Naval Oceanographic Office Technical Notes,

    Science.gov (United States)

    1981-10-01

    Bahamas - Site 1 Deep Reef, by J.G. McDermid. 7210-5-80 Data Report: Moored Current Meter Measurements Unimak Pass, August 1974 7300-5-80 Procedures for the...Moored Current Meter Measurements Unimak Pass 7210-5-80 Data Report: Physical Oceanographic Observation on the Southern California Shelf (July) 7100-11...Loss 3440-C15-78, 3700-86-79, 9000-91-79, 7300-SI-80, 7300-C8-80, 7300-9-80 Unimak Pass 7210-5-80 United Kingdom 3700-008-78 UNIVAC 1108 3700-77-78

  2. Magnetic fields around black holes

    Science.gov (United States)

    Garofalo, David A. G.

    Active Galactic Nuclei are the most powerful long-lived objects in the universe. They are thought to harbor supermassive black holes that range from 1 million solar masses to 1000 times that value and possibly greater. Theory and observation are converging on a model for these objects that involves the conversion of gravitational potential energy of accreting gas to radiation as well as Poynting flux produced by the interaction of the rotating spacetime and the electromagnetic fields originating in the ionized accretion flow. The presence of black holes in astrophysics is taking center stage, with the output from AGN in various forms such as winds and jets influencing the formation and evolution of the host galaxy. This dissertation addresses some of the basic unanswered questions that plague our current understanding of how rotating black holes interact with their surrounding magnetized accretion disks to produce the enormous observed energy. Two magnetic configurations are examined. The first involves magnetic fields connecting the black hole with the inner accretion disk and the other involves large scale magnetic fields threading the disk and the hole. We study the effects of the former type by establishing the consequences that magnetic torques between the black hole and the inner accretion disk have on the energy dissipation profile. We attempt a plausible explanation to the observed "Deep Minimum" state in the Seyfert galaxy MCG-6- 30-15. For the latter type of magnetic geometry, we study the effects of the strength of the magnetic field threading the black hole within the context of the cherished Blandford & Znajek mechanism for black hole spin energy extraction. We begin by addressing the problem in the non-relativistic regime where we find that the black hole-threading magnetic field is stronger for greater disk thickness, larger magnetic Prandtl number, and for a larger accretion disk. We then study the problem in full relativity where we show that our

  3. When Charged Black Holes Merge

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    Most theoretical models assume that black holes arent charged. But a new study shows that mergers of charged black holes could explain a variety of astrophysical phenomena, from fast radio bursts to gamma-ray bursts.No HairThe black hole no hair theorem states that all black holes can be described by just three things: their mass, their spin, and their charge. Masses and spins have been observed and measured, but weve never measured the charge of a black hole and its widely believed that real black holes dont actually have any charge.That said, weve also never shown that black holes dont have charge, or set any upper limits on the charge that they might have. So lets suppose, for a moment, that its possible for a black hole to be charged. How might that affect what we know about the merger of two black holes? A recent theoretical study by Bing Zhang (University of Nevada, Las Vegas) examines this question.Intensity profile of a fast radio burst, a sudden burst of radio emission that lasts only a few milliseconds. [Swinburne Astronomy Productions]Driving TransientsZhangs work envisions a pair of black holes in a binary system. He argues that if just one of the black holes carries charge possibly retained by a rotating magnetosphere then it may be possible for the system to produce an electromagnetic signal that could accompany gravitational waves, such as a fast radio burst or a gamma-ray burst!In Zhangs model, the inspiral of the two black holes generates a global magnetic dipole thats perpendicular to the plane of the binarys orbit. The magnetic flux increases rapidly as the separation between the black holes decreases, generating an increasingly powerful magnetic wind. This wind, in turn, can give rise to a fast radio burst or a gamma-ray burst, depending on the value of the black holes charge.Artists illustration of a short gamma-ray burst, thought to be caused by the merger of two compact objects. [ESO/A. Roquette]Zhang calculates lower limits on the charge

  4. Prisons of Light - Black Holes

    Science.gov (United States)

    Ferguson, Kitty

    1998-05-01

    In this jargon-free review of one of the most fascinating topics in modern science, acclaimed science writer Kitty Ferguson examines the discovery of black holes, their nature, and what they can teach us about the mysteries of the universe. In search of the answers, we trace a star from its birth to its death throes, take a hypothetical journey to the border of a black hole and beyond, spend time with some of the world's leading theoretical physicists and astronomers, and take a whimsical look at some of the wild ideas black holes have inspired. Prisons of Light--Black Holes is comprehensive and detailed. Yet Kitty Ferguson's lightness of touch and down-to-earth analogies set this book apart from all others on black holes and make it a wonderfully stimulating and entertaining read.

  5. String-Corrected Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, V.

    2005-01-12

    We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically alter the causal structure of the solution, converting seemingly pathological null singularities into timelike singularities hidden behind a finite area horizon. We establish, analytically and numerically, that the string-corrected two-charge black hole metric has the same Penrose diagram as the extremal four-charge black hole. The higher derivative terms lead to another dramatic effect--the gravitational force exerted by a black hole on an inertial observer is no longer purely attractive. The magnitude of this effect is related to the size of the compactification manifold.

  6. Are LIGO's Black Holes Made From Smaller Black Holes?

    Science.gov (United States)

    Kohler, Susanna

    2017-05-01

    The recent successes of the Laser Interferometer Gravitational-Wave Observatory (LIGO) has raised hopes that several long-standing questions in black-hole physics will soon be answerable. Besides revealing how the black-hole binary pairs are built, could detections with LIGO also reveal how the black holes themselves form?Isolation or HierarchyThe first detection of gravitational waves, GW150914, was surprising for a number of reasons. One unexpected result was the mass of the two black holes that LIGO saw merging: they were a whopping 29 and 36 solar masses.On the left of this schematic, two first-generation (direct-collapse) black holes form a merging binary. The right illustrates a second-generation hierarchical merger: each black hole in the final merging binary was formed by the merger of two smaller black holes. [Adapted fromGerosa et al., a simultaneously published paper that also explores the problem of hierarchical mergers and reaches similar conclusions]How do black holes of this size form? One possibility is that they form in isolation from the collapse of a single massive star. In an alternative model, they are created through the hierarchical merger of smaller black holes, gradually building up to the size we observed.A team of scientists led by Maya Fishbach (University of Chicago) suggests that we may soon be able to tell whether or not black holes observed by LIGO formed hierarchically. Fishbach and collaborators argue that hierarchical formation leaves a distinctive signature on the spins of the final black holes and that as soon as we have enough merger detections from LIGO, we can use spin measurements to statistically determine if LIGO black holes were formed hierarchically.Spins from Major MergersWhen two black holes merge, both their original spins and the angular momentum of the pair contribute to the spin of the final black hole that results. Fishbach and collaborators calculate the expected distribution of these final spins assuming that

  7. Area spectrum of slowly rotating black holes

    OpenAIRE

    Myung, Yun Soo

    2010-01-01

    We investigate the area spectrum for rotating black holes which are Kerr and BTZ black holes. For slowly rotating black holes, we use the Maggiore's idea combined with Kunstatter's method to derive their area spectra, which are equally spaced.

  8. New entropy formula for Kerr black holes

    OpenAIRE

    Gonzalez, Hernan; Grumiller, Daniel; Merbis, Wout; Wutte, Raphaela

    2017-01-01

    We introduce a new entropy formula for Kerr black holes inspired by recent results for 3-dimensional black holes and cosmologies with soft Heisenberg hair. We show that also Kerr-Taub-NUT black holes obey the same formula.

  9. ICON - Rainbow Gardens Reef 2002 Meteorological and Oceanographic Observations (CMRC1-Lee Stocking Island, Bahamas) (NODC Accession 0048471)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  10. ICON - Rainbow Gardens Reef 2003 Meteorological and Oceanographic Observations (CMRC1-Lee Stocking Island, Bahamas) (NODC Accession 0049498)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  11. ICON - Salt River Bay 2002 Meteorological and Oceanographic Observations (SRVI1-Salt River, St Croix) (NODC Accession 0049497)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  12. ICON - 2015 Meteorological and Oceanographic Observations: Puerto Plata, Catuan Wreck, Little Cayman, Angel's Reef, and Port Everglades (NCEI Accession 0156578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  13. ICON - Salt River Bay 2003 Meteorological and Oceanographic Observations (SRVI1-Salt River, St. Croix) (NODC Accession 0049477)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  14. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2002 Meteorological and Oceanographic Observations (NODC Accession 0049497)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  15. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2003 Meteorological and Oceanographic Observations (NODC Accession 0049477)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  16. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2006 Meteorological and Oceanographic Observations (NODC Accession 0049446)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  17. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2011 Meteorological and Oceanographic Observations (NODC Accession 0098077)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  18. Integrated Coral Observing Network (ICON) - West Fore Reef (Discovery Bay, Jamaica) 2007 Meteorological and Oceanographic Observations (NODC Accession 0054497)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  19. Integrated Coral Observing Network (ICON) - Rainbow Gardens Reef (Lee Stocking Island, Bahamas) 2003 Meteorological and Oceanographic observations (NODC Accession 0049498)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  20. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2008 Meteorological and Oceanographic Observations (NODC Accession 0057130)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  1. Integrated Coral Observing Network (ICON) - Lao Lao Bay, Saipan 2011 Meteorological and Oceanographic Observations (NODC Accession 0098076)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  2. Integrated Coral Observing Network (ICON) - Norman's Patch Reef (Bahamas) 2006 Meteorological and Oceanographic Observations (NODC Accession 0049874)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  3. Integrated Coral Observing Network (ICON) - Rainbow Gardens Reef (Lee Stocking Island, Bahamas) 2002 Meteorological and Oceanographic observations (NODC Accession 0048471)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  4. Integrated Coral Observing Network (ICON) - West Fore Reef (Discovery Bay, Jamaica) 2008 Meteorological and Oceanographic Observations (NODC Accession 0054499)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  5. Integrated Coral Observing Network (ICON) - Norman's Patch Reef (Bahamas) 2007 Meteorological and Oceanographic Observations (NODC Accession 0049875)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  6. Integrated Coral Observing Network (ICON) - Salt River Bay (St. Croix, USVI) 2007 Meteorological and Oceanographic Observations (NODC Accession 0049438)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  7. Temperature, salinity, and sound speed profile data from the US Naval Oceanographic Office (NAVOCEANO) Master Oceanographic Observation Data Set (MOODS), 2002 update (NODC Accession 0000768)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2002, the US Naval Oceanographic Office (NAVOCEANO) submitted these data to NODC in accordance with a Memorandum of Agreement between NODC and NAVOCEANO to...

  8. SCSPOD14, a South China Sea physical oceanographic dataset derived from in situ measurements during 1919–2014

    Science.gov (United States)

    Zeng, Lili; Wang, Dongxiao; Chen, Ju; Wang, Weiqiang; Chen, Rongyu

    2016-01-01

    In addition to the oceanographic data available for the South China Sea (SCS) from the World Ocean Database (WOD) and Array for Real-time Geostrophic Oceanography (Argo) floats, a suite of observations has been made by the South China Sea Institute of Oceanology (SCSIO) starting from the 1970s. Here, we assemble a SCS Physical Oceanographic Dataset (SCSPOD14) based on 51,392 validated temperature and salinity profiles collected from these three datasets for the period 1919–2014. A gridded dataset of climatological monthly mean temperature, salinity, and mixed and isothermal layer depth derived from an objective analysis of profiles is also presented. Comparisons with the World Ocean Atlas (WOA) and IFREMER/LOS Mixed Layer Depth Climatology confirm the reliability of the new dataset. This unique dataset offers an invaluable baseline perspective on the thermodynamic processes, spatial and temporal variability of water masses, and basin-scale and mesoscale oceanic structures in the SCS. We anticipate improvements and regular updates to this product as more observations become available from existing and future in situ networks. PMID:27116565

  9. VTrans Small Culvert Inventory - Access Holes

    Data.gov (United States)

    Vermont Center for Geographic Information — Vermont Agency of Transportation Small Culvert Inventory: Access Holes. This data contains access hole locations along VTrans maintained roadways. The data was...

  10. A variable resolution right TIN approach for gridded oceanographic data

    Science.gov (United States)

    Marks, David; Elmore, Paul; Blain, Cheryl Ann; Bourgeois, Brian; Petry, Frederick; Ferrini, Vicki

    2017-12-01

    Many oceanographic applications require multi resolution representation of gridded data such as for bathymetric data. Although triangular irregular networks (TINs) allow for variable resolution, they do not provide a gridded structure. Right TINs (RTINs) are compatible with a gridded structure. We explored the use of two approaches for RTINs termed top-down and bottom-up implementations. We illustrate why the latter is most appropriate for gridded data and describe for this technique how the data can be thinned. While both the top-down and bottom-up approaches accurately preserve the surface morphology of any given region, the top-down method of vertex placement can fail to match the actual vertex locations of the underlying grid in many instances, resulting in obscured topology/bathymetry. Finally we describe the use of the bottom-up approach and data thinning in two applications. The first is to provide thinned, variable resolution bathymetry data for tests of storm surge and inundation modeling, in particular hurricane Katrina. Secondly we consider the use of the approach for an application to an oceanographic data grid of 3-D ocean temperature.

  11. Black Holes Are The Rhythm at The Heart of Galaxies

    Science.gov (United States)

    2008-11-01

    The powerful black holes at the center of massive galaxies and galaxy clusters act as hearts to the systems, pumping energy out at regular intervals to regulate the growth of the black holes themselves, as well as star formation, according to new data from NASA's Chandra X-Ray Observatory. People Who Read This Also Read... Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago A New Way To Weigh Giant Black Holes Discovery of Most Recent Supernova in Our Galaxy NASA Unveils Cosmic Images Book in Braille for Blind Readers Scientists from the University of Michigan, the Max-Planck Institute for Extraterrestrial Physics in Germany, the University of Maryland, Baltimore County (UMBC), the Harvard-Smithsonian Center for Astrophysics and Jacobs University in Germany contributed to the results. The gravitational pull of black holes is so strong that not even light can escape from them. Supermassive black holes with masses of more than a billion suns have been detected at the center of large galaxies. The material falling on the black holes causes sporadic or isolated bursts of energy, by which black holes are capable of influencing the fate of their host galaxies. The insight gained by this new research shows that black holes can pump energy in a gentler and rhythmic fashion, rather then violently. The scientists observed and simulated how the black hole at the center of elliptical galaxy M84 dependably sends bubbles of hot plasma into space, heating up interstellar space. This heat is believed to slow both the formation of new stars and the growth of the black hole itself, helping the galaxy remain stable. Interstellar gases only coalesce into new stars when the gas is cool enough. The heating is more efficient at the sites where it is most needed, the scientists say. Alexis Finoguenov, of UMBC and the Max-Planck Institute for Extraterrestrial Physics in Germany, compares the central black hole to a heart muscle. "Just like our hearts periodically pump our

  12. Black Hole Grabs Starry Snack

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Poster Version This artist's concept shows a supermassive black hole at the center of a remote galaxy digesting the remnants of a star. NASA's Galaxy Evolution Explorer had a 'ringside' seat for this feeding frenzy, using its ultraviolet eyes to study the process from beginning to end. The artist's concept chronicles the star being ripped apart and swallowed by the cosmic beast over time. First, the intact sun-like star (left) ventures too close to the black hole, and its own self-gravity is overwhelmed by the black hole's gravity. The star then stretches apart (middle yellow blob) and eventually breaks into stellar crumbs, some of which swirl into the black hole (cloudy ring at right). This doomed material heats up and radiates light, including ultraviolet light, before disappearing forever into the black hole. The Galaxy Evolution Explorer was able to watch this process unfold by observing changes in ultraviolet light. The area around the black hole appears warped because the gravity of the black hole acts like a lens, twisting and distorting light.

  13. Evolutionary institutionalism.

    Science.gov (United States)

    Fürstenberg, Dr Kai

    Institutions are hard to define and hard to study. Long prominent in political science have been two theories: Rational Choice Institutionalism (RCI) and Historical Institutionalism (HI). Arising from the life sciences is now a third: Evolutionary Institutionalism (EI). Comparative strengths and weaknesses of these three theories warrant review, and the value-to-be-added by expanding the third beyond Darwinian evolutionary theory deserves consideration. Should evolutionary institutionalism expand to accommodate new understanding in ecology, such as might apply to the emergence of stability, and in genetics, such as might apply to political behavior? Core arguments are reviewed for each theory with more detailed exposition of the third, EI. Particular attention is paid to EI's gene-institution analogy; to variation, selection, and retention of institutional traits; to endogeneity and exogeneity; to agency and structure; and to ecosystem effects, institutional stability, and empirical limitations in behavioral genetics. RCI, HI, and EI are distinct but complementary. Institutional change, while amenable to rational-choice analysis and, retrospectively, to criticaljuncture and path-dependency analysis, is also, and importantly, ecological. Stability, like change, is an emergent property of institutions, which tend to stabilize after change in a manner analogous to allopatric speciation. EI is more than metaphorically biological in that institutional behaviors are driven by human behaviors whose evolution long preceded the appearance of institutions themselves.

  14. Institutional advantage

    NARCIS (Netherlands)

    Martin, Xavier

    Is there such a thing as institutional advantage—and what does it mean for the study of corporate competitive advantage? In this article, I develop the concept of institutional competitive advantage, as distinct from plain competitive advantage and from comparative institutional advantage. I first

  15. Atlantic coastal plain geothermal test holes, Virginia: hole completion reports

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, L.B.; Radford, L.; Glascock, M.

    1979-03-01

    A description of the Atlantic Coastal Plain Geothermal Drilling Program and data for the following geothermal test holes drilled in Virginia are summarized: Creeds, Norfolk Naval Base, Langley Air Force Base, Wattsville, Withams, and Atlantic.

  16. Unveiling the edge of time black holes, white holes, wormholes

    CERN Document Server

    Gribbin, John

    1992-01-01

    Acclaimed science writer John Gribbin recounts dramatic stories that have led scientists to believe black holes and their more mysterious kin are not only real, but might actually provide a passage to other universes and travel through time.

  17. Quantum mechanics of black holes.

    Science.gov (United States)

    Witten, Edward

    2012-08-03

    The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general relativity. These objects swallow up whatever comes near and emit nothing. Physicists who have tried to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived at quite a different picture. The difference is analogous to the difference between thermodynamics and statistical mechanics. The thermodynamic description is a good approximation for a macroscopic system, but statistical mechanics describes what one will see if one looks more closely.

  18. Orbital resonances around black holes.

    Science.gov (United States)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

  19. Black holes and Higgs stability

    CERN Document Server

    Tetradis, Nikolaos

    2016-09-20

    We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum. We find that the energy barrier for transitions to the new vacuum, which characterizes the exponential suppression of the nucleation rate, can be reduced significantly in the black-hole background. A precise analysis is required in order to determine whether the the existence of primordial black holes is compatible with the form of the Higgs potential at high temperature or density in the Standard Model or its extensions.

  20. Heating solar coronal holes

    Science.gov (United States)

    Parker, E. N.

    1991-01-01

    It has been shown that the coronal hole, and the associated high-speed stream in the solar wind, are powered by a heat input of the order of 500,000 ergs/sq cm s, with most of the heat injected in the first 1-2 solar radii, and perhaps 100,000 ergs/sq cm s introduced at distances of several solar radii to provide the high speed of the issuing solar wind. The traditional view has been that this energy is obtained from Alfven waves generated in the subphotospheric convection, which dissipate as they propagate outward, converting the wave energy into heat. This paper reviews the generation of waves and the known wave dissipation mechanisms, to show that the necessary Alfven waves are not produced under the conditions presently understood to exist in the sun, nor would such waves dissipate significantly in the first 1-2 solar radii if they existed. Wave dissipation occurs only over distances of the order of 5 solar radii or more.

  1. Bottom hole blowout preventer

    Energy Technology Data Exchange (ETDEWEB)

    Lineham, D.H.

    1991-04-24

    An automatically controlled ball-valve type bottom-hole blowout preventer is provided for use in drilling oil or gas wells. The blowout preventer of the invention operates under normal drilling conditions in a fully open position with an unrestricted bore. This condition is maintained by a combination of spring and mud flow pressure acting against the upper surfaces of the valve. In the event of a well kick or blowout, pressures from gas or fluid volumes acting against the lower surfaces of the valve force it into the fully closed position. A system of ports and check valves within the blowout preventer forces hydraulic fluid from one chamber to another. The metering effect of these ports determines the rate of closure of the valve, thereby allowing normal running and pulling of the drill string or tubing, without interference to pipe fill-up or drainage, from valve closure. The blowout preventer is placed in a subassembly that is an integral part of the drill string and can be incorporated in a string in any location. 3 figs.

  2. Black hole meiosis

    Science.gov (United States)

    van Herck, Walter; Wyder, Thomas

    2010-04-01

    The enumeration of BPS bound states in string theory needs refinement. Studying partition functions of particles made from D-branes wrapped on algebraic Calabi-Yau 3-folds, and classifying states using split attractor flow trees, we extend the method for computing a refined BPS index, [1]. For certain D-particles, a finite number of microstates, namely polar states, exclusively realized as bound states, determine an entire partition function (elliptic genus). This underlines their crucial importance: one might call them the ‘chromosomes’ of a D-particle or a black hole. As polar states also can be affected by our refinement, previous predictions on elliptic genera are modified. This can be metaphorically interpreted as ‘crossing-over in the meiosis of a D-particle’. Our results improve on [2], provide non-trivial evidence for a strong split attractor flow tree conjecture, and thus suggest that we indeed exhaust the BPS spectrum. In the D-brane description of a bound state, the necessity for refinement results from the fact that tachyonic strings split up constituent states into ‘generic’ and ‘special’ states. These are enumerated separately by topological invariants, which turn out to be partitions of Donaldson-Thomas invariants. As modular predictions provide a check on many of our results, we have compelling evidence that our computations are correct.

  3. Institutional entrepreneurship:

    DEFF Research Database (Denmark)

    Gretzinger, Susanne

    2018-01-01

    of agents or organisations in the policy arena. The present chapter understands institutional entrepreneurship as the process of changing institutionalised practices. Based on a literature review, it describes the triggers, activities and potential effects of institutional entrepreneurs. The chapter......Institutional entrepreneurship pays specific attention to the process and outcomes of agents who are willing and capable of changing institutions. It has some common ground with the political entrepreneur, a concept that proposes change in norms and institutions because of commitment and activities...... concludes by tentatively arguing that political entrepreneurs can be institutional entrepreneurs, but institutional entrepreneurship can be considered as the broader concept that incorporates strategies and visions as well as interpretative-discursive power into the conceptual framework....

  4. Erratic Black Hole Regulates Itself

    Science.gov (United States)

    2009-03-01

    New results from NASA's Chandra X-ray Observatory have made a major advance in explaining how a special class of black holes may shut off the high-speed jets they produce. These results suggest that these black holes have a mechanism for regulating the rate at which they grow. Black holes come in many sizes: the supermassive ones, including those in quasars, which weigh in at millions to billions of times the mass of the Sun, and the much smaller stellar-mass black holes which have measured masses in the range of about 7 to 25 times the Sun's mass. Some stellar-mass black holes launch powerful jets of particles and radiation, like seen in quasars, and are called "micro-quasars". The new study looks at a famous micro-quasar in our own Galaxy, and regions close to its event horizon, or point of no return. This system, GRS 1915+105 (GRS 1915 for short), contains a black hole about 14 times the mass of the Sun that is feeding off material from a nearby companion star. As the material swirls toward the black hole, an accretion disk forms. This system shows remarkably unpredictable and complicated variability ranging from timescales of seconds to months, including 14 different patterns of variation. These variations are caused by a poorly understood connection between the disk and the radio jet seen in GRS 1915. Chandra, with its spectrograph, has observed GRS 1915 eleven times since its launch in 1999. These studies reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole. The wind is believed to shut down the jet by depriving it of matter that would have otherwise fueled it. Conversely, once the wind dies down, the jet can re-emerge. "We think the jet and wind around this black hole are in a sort of tug of war," said Joseph Neilsen, Harvard graduate student and lead author of the paper appearing in the journal Nature. "Sometimes one is winning and then, for reasons we don

  5. Black Hole Caught Zapping Galaxy into Existence?

    Science.gov (United States)

    2009-11-01

    across the whole electromagnetic spectrum; particularly spectacular is the case of quasars, where the active core is so overwhelmingly bright that it outshines the luminosity of the host galaxy. [2] This part of the study is based on observations performed at mid-infrared wavelengths, with the powerful VLT spectrometer and imager for the mid-infrared (VISIR) instrument at the VLT, combined with additional data including: spectra acquired using VLT-FORS, optical and infrared images from the NASA/ESA Hubble Space Telescope, and radio observations from the Australia Telescope National Facility. [3] Most galaxies in the local Universe contain a supermassive black hole with a mass about 1/700th the mass of the stellar bulge. The origin of this black hole mass versus stellar mass relation is one of the most debated subjects in modern astrophysics. More information This research was presented in papers published in the journal Astronomy & Astrophysics: "Quasar induced galaxy formation: a new paradigm?" by Elbaz et al., and in the Astrophysical Journal "The QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG" by Jahnke et al. The team is composed of David Elbaz (Service d'Astrophysique, CEA Saclay, France), Knud Jahnke (Max Planck Institute for Astronomy, Heidelberg, Germany), Eric Pantin (Service d'Astrophysique, CEA Saclay, France), Damien Le Borgne (Paris University 6 and CNRS, Institut d'Astrophysique de Paris, France) and Géraldine Letawe (Institut d'Astrophysique et de Géophysique, Université de Liège, Belgium). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design

  6. The physics of black holes

    CERN Document Server

    Susskind, Leonard

    1997-01-01

    I will describe profound revolution in our understanding of black holes and their relation to quantum mechanics that has occured over the last few years as a result of a deeper understanding of string theory.

  7. Chandra Clinches Case for Missing Link Black Hole

    Science.gov (United States)

    2000-09-01

    The strongest evidence yet that the universe is home to a new type of black hole was reported by several groups of scientists today Using NASA's Chandra X-ray Observatory, scientists have zeroed in on a mid-mass black hole in the galaxy M82. This black hole - located 600 light years away from the center of a galaxy - may represent the missing link between smaller stellar black holes and the supermassive variety found at the centers of galaxies. "This opens a whole new field of research," said Martin Ward of the University of Leicester, UK, a lead author involved with the observations. "No one was sure that such black holes existed, especially outside the centers of galaxies." The black hole in M82 packs the mass of at least 500 suns into a region about the size of the Moon. Such a black hole would require extreme conditions for its creation, such as the collapse of a "hyperstar" or the merger of scores of black holes. The result comes as Chandra starts its second year of operation and is testimony to how Chandra's power and precision is changing the field of astronomy. "This black hole might eventually sink to the center of the galaxy," said Dr. Hironori Matsumoto of the Massachusetts Institute of Technology, the lead author on one of three Chandra papers scheduled to be published on the mid-mass black hole, "where it could grow to become a supermassive black hole." Although previous X-ray data from the German-U.S. Roentgen Satellite and the Japan-U.S. ASCA Satellite suggested that a mid-mass black hole might exist in M82, the crucial breakthrough came when astronomers compared the new high resolution Chandra data with optical, radio, and infrared maps of the region. They determined that most of the X-rays were coming from a single bright source. Repeated observations of M82 over a period of eight months showed the bright X-ray source gradually peaking in X-ray brightness before dimming. Another critical discovery was that the intensity of the X rays was rising and

  8. Hole dephasing caused by hole-hole interaction in a multilayered black phosphorus.

    Science.gov (United States)

    Li, Lijun; Khan, Muhammad Atif; Lee, Yoontae; Lee, Inyeal; Yun, Sun Jin; Youn, Doo-Hyeb; Kim, Gil-Ho

    2017-11-01

    We study the magnetotransport of holes in a multilayered black phosphorus in a temperature range of 1.9 to 21.5 K. We observed a negative magnetoresistance at magnetic fields up to 1.5 T. This negative magetoresistance was analyzed by weak localization theory in diffusive regime. At the lowest temperature and the highest carrier density we found a phase coherence length of 48 nm. The linear temperature dependence of the dephasing rate shows that the hole-hole scattering processes with small energy transfer are the dominant contribution in breaking the carrier phase coherence.

  9. Measuring the Value of Research Data: A Citation Analysis of Oceanographic Data Sets

    Science.gov (United States)

    Belter, Christopher W.

    2014-01-01

    Evaluation of scientific research is becoming increasingly reliant on publication-based bibliometric indicators, which may result in the devaluation of other scientific activities - such as data curation – that do not necessarily result in the production of scientific publications. This issue may undermine the movement to openly share and cite data sets in scientific publications because researchers are unlikely to devote the effort necessary to curate their research data if they are unlikely to receive credit for doing so. This analysis attempts to demonstrate the bibliometric impact of properly curated and openly accessible data sets by attempting to generate citation counts for three data sets archived at the National Oceanographic Data Center. My findings suggest that all three data sets are highly cited, with estimated citation counts in most cases higher than 99% of all the journal articles published in Oceanography during the same years. I also find that methods of citing and referring to these data sets in scientific publications are highly inconsistent, despite the fact that a formal citation format is suggested for each data set. These findings have important implications for developing a data citation format, encouraging researchers to properly curate their research data, and evaluating the bibliometric impact of individuals and institutions. PMID:24671177

  10. Measuring the value of research data: a citation analysis of oceanographic data sets.

    Science.gov (United States)

    Belter, Christopher W

    2014-01-01

    Evaluation of scientific research is becoming increasingly reliant on publication-based bibliometric indicators, which may result in the devaluation of other scientific activities--such as data curation--that do not necessarily result in the production of scientific publications. This issue may undermine the movement to openly share and cite data sets in scientific publications because researchers are unlikely to devote the effort necessary to curate their research data if they are unlikely to receive credit for doing so. This analysis attempts to demonstrate the bibliometric impact of properly curated and openly accessible data sets by attempting to generate citation counts for three data sets archived at the National Oceanographic Data Center. My findings suggest that all three data sets are highly cited, with estimated citation counts in most cases higher than 99% of all the journal articles published in Oceanography during the same years. I also find that methods of citing and referring to these data sets in scientific publications are highly inconsistent, despite the fact that a formal citation format is suggested for each data set. These findings have important implications for developing a data citation format, encouraging researchers to properly curate their research data, and evaluating the bibliometric impact of individuals and institutions.

  11. The 2002 Antarctic Ozone Hole

    Science.gov (United States)

    Newman, P. A.; Nash, E. R.; Douglass, A. R.; Kawa, S. R.

    2003-01-01

    Since 1979, the ozone hole has grown from near zero size to over 24 Million km2. This area is most strongly controlled by levels of inorganic chlorine and bromine oncentrations. In addition, dynamical variations modulate the size of the ozone hole by either cooling or warming the polar vortex collar region. We will review the size observations, the size trends, and the interannual variability of the size. Using a simple trajectory model, we will demonstrate the sensitivity of the ozone hole to dynamical forcing, and we will use these observations to discuss the size of the ozone hole during the 2002 Austral spring. We will further show how the Cly decreases in the stratosphere will cause the ozone hole to decrease by 1-1.5% per year. We will also show results from a 3-D chemical transport model (CTM) that has been continuously run since 1999. These CTM results directly show how strong dynamics acts to reduce the size of the ozone hole.

  12. Black Hole Spin Measurement Uncertainty

    Science.gov (United States)

    Salvesen, Greg; Begelman, Mitchell C.

    2018-01-01

    Angular momentum, or spin, is one of only two fundamental properties of astrophysical black holes, and measuring its value has numerous applications. For instance, obtaining reliable spin measurements could constrain the growth history of supermassive black holes and reveal whether relativistic jets are powered by tapping into the black hole spin reservoir. The two well-established techniques for measuring black hole spin can both be applied to X-ray binaries, but are in disagreement for cases of non-maximal spin. This discrepancy must be resolved if either technique is to be deemed robust. We show that the technique based on disc continuum fitting is sensitive to uncertainties regarding the disc atmosphere, which are observationally unconstrained. By incorporating reasonable uncertainties into black hole spin probability density functions, we demonstrate that the spin measured by disc continuum fitting can become highly uncertain. Future work toward understanding how the observed disc continuum is altered by atmospheric physics, particularly magnetic fields, will further strengthen black hole spin measurement techniques.

  13. GOODS Missing Black Hole Report: Hundreds Found!

    Science.gov (United States)

    2007-10-01

    Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away Normal Galaxies Normal Galaxies The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there are hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance. "Active, supermassive black holes are everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Dickinson is a co-author of two new papers appearing in the Nov. 10 issue of the Astrophysical Journal. Emanuele Daddi of the Commissariat a l'Energie Atomique in France led the research. The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spend their youths building monstrous black holes at their cores. For decades, large populations of active black holes have been considered missing. These highly energetic structures, also called quasars, consist of a dusty, doughnut-shaped cloud that surrounds and feeds a growing supermassive black hole. They give off a lot of X-rays that can be detected as a general glow in space, but sometimes the quasars themselves can't be seen because dust and gas blocks their X-rays from our point of view. "We knew from other studies from about 30 years ago that there must be more quasars in the universe, but we didn't know where to find them until now," said Daddi. Daddi and his team initially set out to study 1,000 dusty, massive galaxies that are busy making stars, and were thought to lack quasars. The galaxies are about the same mass as our own spiral Milky Way galaxy, but irregular in shape. At 9 to 11 billion light-years away, they exist at a

  14. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the conjecture that the primordial black holes ...

  15. Formation and Coalescence of Electron Solitary Holes

    DEFF Research Database (Denmark)

    Saeki, K.; Michelsen, Poul; Pécseli, H. L.

    1979-01-01

    Electron solitary holes were observed in a magnetized collisionless plasma. These holes were identified as Bernstein-Green-Kruskal equilibria, thus being purely kinetic phenomena. The electron hole does not damp even though its velocity is close to the electron thermal velocity. Two holes attract...

  16. Relationships between tuna catch and variable frequency oceanographic conditions

    Directory of Open Access Journals (Sweden)

    F. I. Ormaza-González

    2016-08-01

    Full Text Available Skipjack (Katsuwunus pelamis, yellow fin (Thunnus albacares and albacore (Thunnus alulunga tunas landed in the Eastern Pacific Ocean (EPO countries and Ecuador were correlated to the Indexes Oceanic El Niño (ONI and Multivariate Enso Index (MEI. The temporal series 1983–2012, and 1977–1999 (warm Pacific Decadal Oscillation, PDO, and 2000–2012 (cold PDO were analyzed. Linear correlation showed that at least 11 % of the total landings were associated with the MEI, with a slightly negative gradient from cold to warm conditions. When non-linear regression (n  =  6, the R2 was higher up to 0.304 (MEI, r =  0.551. The correlation shows high spread from −0.5 to +0.5 for both MEI/ONI; the highest landings occurred at 0.34–0.45; both indexes suggested that at extreme values < −1.0 and > 1.1 total landings tend to decrease. Landings were associated up to 21.9 % (MEI in 2000–2012, 1983–1999 rendered lower R2 (< 0.09; i.e., during cold PDO periods there was a higher association between landings and oceanographic conditions. For the non-linear regression (n  =  6 a R2 of 0.374 (MEI and 0.408 (ONI were registered, for the 2000–2012, a higher R2 was observed in 1983–1999, 0.443 and 0.711 for MEI and ONI respectively, suggesting that is better to analyze split series (1983–1999, 2000–2012 than as a whole (1983–2012, due to noise produced by the transition from hot to cold PDOs. The highest landings were in the range −0.2 to 0.5 for MEI/ONI. The linear regression of skipjack landings in Ecuador gave an R2 of 0.140 (MEI and 0.066 (ONI and the non-linear were 0.440 and 0.183 respectively. Total landings in the EPO associated to oceanographic events of high and low frequencies could be used somehow as predictors of the high El Niño o La Niña. There is a clear evidence that tuna fish biomass are at higher levels when the PDO is on cold phase (2000–2030 and vice versa on warm phase (1980–1999. The

  17. Self-shading correction for oceanographic upwelling radiometers.

    Science.gov (United States)

    Leathers, Robert; Downes, Trijntje; Mobley, Cutris

    2004-10-04

    We present the derivation of an analytical model for the self-shading error of an oceanographic upwelling radiometer. The radiometer is assumed to be cylindrical and can either be a profiling instrument or include a wider cylindrical buoy for floating at the sea surface. The model treats both optically shallow and optically deep water conditions and can be applied any distance off the seafloor. We evaluate the model by comparing its results to those from Monte Carlo simulations. The analytical model performs well over a large range of environmental conditions and provides a significant improvement to previous analytical models. The model is intended for investigators who need to apply self-shading corrections to radiometer data but who do not have the ability to compute shading corrections with Monte Carlo simulations. The model also can provide guidance for instrument design and cruise planning.

  18. Glacial oceanographic contrasts explain phylogeography of Australian bull kelp.

    Science.gov (United States)

    Fraser, Ceridwen I; Spencer, Hamish G; Waters, Jonathan M

    2009-05-01

    The evolutionary effects of Southern Hemisphere Pleistocene oceanographic conditions - marked by fluctuations in sea levels and water temperatures, and redirected currents - are poorly understood. The southeastern tip of Australia presents an intriguing model system for studying the biological impacts of palaeoceanography. In particular, contrasting oceanographic conditions that existed on eastern vs. western sides of the Bassian Isthmus during Pleistocene glacial periods allow for natural comparisons between putative refugial vs. re-invading populations. Whereas many western Tasmanian marine taxa were likely eliminated by cold subantarctic water during the last glacial period, eastern Tasmanian populations would have persisted in relatively warm temperatures mediated by the ongoing influence of the East Australian Current (EAC). Here we test for the effects of contrasting palaeoceanographic conditions on endemic bull kelp, Durvillaea potatorum, using DNA sequence analysis (COI; rbcL) of more than 100 individuals from 14 localities in southeastern Australia. Phylogenetic reconstructions reveal a deep (maximum divergence 4.7%) genetic split within D. potatorum, corresponding to the 'eastern' and 'western' geographical regions delimited by the Bassian Isthmus, a vicariant barrier during low Pleistocene sea levels. Concordant with the western region's cold glacial conditions, samples from western Tasmania and western Victoria are genetically monomorphic, suggesting postglacial expansion from a mainland refugium. Eastern samples, in contrast, comprise distinct regional haplogroups, suggesting the species persisted in eastern Tasmania throughout recent glacial periods. The deep east-west divergence seems consistent with earlier reports of morphological differences between 'western' and 'eastern' D. potatorum, and it seems likely that these forms represent reproductively isolated species.

  19. Oceanographic controls over sediment water content: northern Bermuda rise

    Energy Technology Data Exchange (ETDEWEB)

    Baker, M.; Laine, E.P.

    1985-01-01

    Cores taken from the plateaus of Northern Bermuda Rise show that the region is underlain at depths of 1-5 m by a 1-3 m thick layer of hemipelagic lutites with anomalously high water contents. The lack of visually apparent textural and lithological changes in this extremely fine grained sediment rule out these common causes for variation in water content. The water content averages 175% within this layer and 100% immediately above and below it. This is an increase of 9.5% in porosity. The high water content sediment is confined to a period between 12 and 16 ka. Current work on the mineralogy of the sediments which comprise this layer suggest two oceanographic factors that may have influenced its formation. A meltwater spike associated with deglaciation may have altered the ecological conditions above the thermocline sufficiently to promote the increased production of radiolaria, resulting in the deposition of silica enriched sediment on the sea floor. A combination of textural and perhaps chemical factors caused by the silica enrichment may have influenced the increase in water content. Intensified bottom currents at this time also may have eroded smectite rich sediments from exposures of Neogene age and deposited them on the plateaus. An increase in smectite would increase the water content due to the extremely fine grain size and the chemistry of the clay. Thus, the lateral continuity and isochroniety of this layer, combined with its mineralogical characteristics suggests that oceanographic changes can influence water content and perhaps other geotechnical properties on a regional scale.

  20. Rethinking Black Hole Accretion Discs

    Science.gov (United States)

    Salvesen, Greg

    Accretion discs are staples of astrophysics. Tapping into the gravitational potential energy of the accreting material, these discs are highly efficient machines that produce copious radiation and extreme outflows. While interesting in their own right, accretion discs also act as tools to study black holes and directly influence the properties of the Universe. Black hole X-ray binaries are fantastic natural laboratories for studying accretion disc physics and black hole phenomena. Among many of the curious behaviors exhibited by these systems are black hole state transitions -- complicated cycles of dramatic brightening and dimming. Using X-ray observations with high temporal cadence, we show that the evolution of the accretion disc spectrum during black hole state transitions can be described by a variable disc atmospheric structure without invoking a radially truncated disc geometry. The accretion disc spectrum can be a powerful diagnostic for measuring black hole spin if the effects of the disc atmosphere on the emergent spectrum are well-understood; however, properties of the disc atmosphere are largely unconstrained. Using statistical methods, we decompose this black hole spin measurement technique and show that modest uncertainties regarding the disc atmosphere can lead to erroneous spin measurements. The vertical structure of the disc is difficult to constrain due to our ignorance of the contribution to hydrostatic balance by magnetic fields, which are fundamental to the accretion process. Observations of black hole X-ray binaries and the accretion environments near supermassive black holes provide mounting evidence for strong magnetization. Performing numerical simulations of accretion discs in the shearing box approximation, we impose a net vertical magnetic flux that allows us to effectively control the level of disc magnetization. We study how dynamo activity and the properties of turbulence driven by the magnetorotational instability depend on the

  1. Regular black hole in three dimensions

    OpenAIRE

    Myung, Yun Soo; Yoon, Myungseok

    2008-01-01

    We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.

  2. Electrically charged matter in rigid rotation around magnetized black hole

    Czech Academy of Sciences Publication Activity Database

    Kovář, J.; Slaný, P.; Cremaschini, C.; Stuchlík, Z.; Karas, Vladimír; Trova, Audrey

    2014-01-01

    Roč. 90, č. 4 (2014), 044029/1-044029/14 ISSN 1550-7998 R&D Projects: GA ČR GB14-37086G Grant - others:GA ČR(CZ) GP14-07753P Institutional support: RVO:67985815 Keywords : black hole s * accretion disks Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.643, year: 2014

  3. Oceanographic Survey in waters of the Northern Mariana Islands, Guam, and Micronesia (SE1003, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of the cruise were to collect acoustic backscatter and oceanographic data at the vicinity of CNMI, Guam, and in the northern part of Micronesia. Data...

  4. Oceanographic Survey in the American Samoa Exclusive Economic Zone (EEZ) (OES0602, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic data were collected along five predetermined transects in the American Samoa EEZ and consisted of CTD casts, trawl samples, and continuous current and...

  5. Oceanographic Survey of Cross Seamount and Control Sites (OES0703L1, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of the cruise were to collect acoustic backscatter and oceanographic data at Cross Seamount (18?43.285? N, longitude 158? 15.710? W), with an approximately...

  6. Data from Oceanographer, Lydonia, and Gilbert Canyons acquired in 1965 (SCHWARTZ65 shapefile)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Submarine canyons occur at the edge of the continental shelf and cut across the slope and rise along the U.S. east coast. Three of these canyons (Oceanographer,...

  7. AFSC/ABL: Little Port Walter Marine Research Station Supply Run Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In November, 2006, Oceanographic observations were initiated during the resupply cruises to the Little Port Walter Research Station on lower Baranof Island,...

  8. Design and performance evaluation of a hall effect magnetic compass for oceanographic and meteorological applications

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desai, R.G.P.; Agarvadekar, Y.; Tengali, T.; Mishra, M.; Fadate, C.; Gomes, L.

    A Hall Effect magnetic compass, suitable for oceanographic and meteorological applications, has been designed and its performance characteristics have been evaluated. Slope of the least-squares-fitted linear graph was found to be close to the ideal...

  9. Japan Oceanographic Data Center (JODC) Descriptions of Seafloor Sediment Through 1975

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This file was compiled by the Japan Oceanographic Data Center using the IOC Marine Geological Data Format. It includes 748 master records and 1740 data records. It...

  10. USGS HYDRoacoustic dataset in support of the Surface Water Oceanographic Topography satellite mission (HYDRoSWOT)

    Data.gov (United States)

    Department of the Interior — HYDRoSWOT – HYDRoacoustic dataset in support of Surface Water Oceanographic Topography – is a data set that aggregates channel and flow data collected from the USGS...

  11. Oceanographic Survey of Cross Seamount and Control Sites (OES0505, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the cruise was to collect physical and biological oceanographic data at three distinct environment in the lee of the Island of Hawaii: a relatively...

  12. Oceanographic Profile Data from Glacier Fjords of Alaska, 2004-2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains physical oceanographic data within four fjords in the coastal area of the Gulf of Alaska. Data were collected with a Seabird Electronics...

  13. The coastal regulation zone of Goa: Oceanographic, environmental and societal perspectives

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.

    sufficient oceanographic and environmental validity to be upheld. However, this instrument is being opposed and misinterpreted. Sectoral practices, partisan policies, unbalanced tourism, and absence of political will have all contributed to the CRZ being...

  14. Charge carrier holes and Majorana fermions

    Science.gov (United States)

    Liang, Jingcheng; Lyanda-Geller, Yuli

    2017-05-01

    Understanding Luttinger holes in low dimensions is crucial for numerous spin-dependent phenomena and nanotechnology. In particular, hole quantum wires that are proximity coupled to a superconductor is a promising system for the observation of Majorana fermions. Earlier treatments of confined Luttinger holes ignored a mutual transformation of heavy and light holes at the heteroboundaries. We derive the effective hole Hamiltonian in the ground state. The mutual transformation of holes is crucial for Zeeman and spin-orbit coupling, and results in several spin-orbit terms linear in momentum in hole quantum wires. We discuss the criterion for realizing Majorana modes in charge carrier hole systems. GaAs or InSb hole wires shall exhibit stronger topological superconducting pairing, and provide additional opportunities for its control compared to InSb electron systems.

  15. Institutional actorhood

    DEFF Research Database (Denmark)

    Madsen, Christian Uhrenholdt

    In this paper I describe the changing role of intra-organizational experts in the face of institutional complexity of their field. I do this through a qualitative investigation of the institutional and organizational roles of actors in Danish organizations who are responsible for the efforts...... to comply with the Danish work environment regulation. And by doing so I also describe how institutional complexity and organizational responses to this complexity are particular important for the changing modes of governance that characterizes contemporary welfare states....

  16. Lectures on Quantum Black Holes

    CERN Document Server

    Dabholkar, Atish

    2012-01-01

    In these notes we describe recent progress in understanding finite size corrections to the black hole entropy. Much of the earlier work concerning quantum black holes has been in the limit of large charges when the area of the even horizon is also large. In recent years there has been substantial progress in understanding the entropy of supersymmetric black holes within string theory going well beyond the large charge limit. It has now become possible to begin exploring finite size effects in perturbation theory in inverse size and even nonperturbatively, with highly nontrivial agreements between thermodynamics and statistical mechanics. Unlike the leading Bekenstein-Hawking entropy which follows from the two-derivative Einstein-Hilbert action, these finite size corrections depend sensitively on the phase under consideration and contain a wealth of information about the details of compactification as well as the spectrum of nonperturbative states in the theory. Finite-size corrections are therefore very inter...

  17. Massive Black Holes and Galaxies

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Evidence has been accumulating for several decades that many galaxies harbor central mass concentrations that may be in the form of black holes with masses between a few million to a few billion time the mass of the Sun. I will discuss measurements over the last two decades, employing adaptive optics imaging and spectroscopy on large ground-based telescopes that prove the existence of such a massive black hole in the Center of our Milky Way, beyond any reasonable doubt. These data also provide key insights into its properties and environment. Most recently, a tidally disrupting cloud of gas has been discovered on an almost radial orbit that reached its peri-distance of ~2000 Schwarzschild radii in 2014, promising to be a valuable tool for exploring the innermost accretion zone. Future interferometric studies of the Galactic Center Black hole promise to be able to test gravity in its strong field limit.

  18. The black hole quantum atmosphere

    Science.gov (United States)

    Dey, Ramit; Liberati, Stefano; Pranzetti, Daniele

    2017-11-01

    Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate. Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan-Boltzmann law. In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor. We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about 4 MG, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon. This long distance origin of Hawking radiation could have a profound impact on our understanding of the information and transplanckian problems.

  19. Black holes and galaxy formation

    CERN Document Server

    Propst, Raphael J

    2010-01-01

    Galaxies are the basic unit of cosmology. The study of galaxy formation is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning. The physics of galaxy formation is complicated because it deals with the dynamics of stars, thermodynamics of gas and energy production of stars. A black hole is a massive object whose gravitational field is so intense that it prevents any form of matter or radiation to escape. It is hypothesized that the most massive galaxies in the universe- "elliptical galaxies"- grow simultaneously with the supermassive black holes at their centers, giving us much stronger evidence that black holes control galaxy formation. This book reviews new evidence in the field.

  20. Black holes and random matrices

    Science.gov (United States)

    Cotler, Jordan S.; Gur-Ari, Guy; Hanada, Masanori; Polchinski, Joseph; Saad, Phil; Shenker, Stephen H.; Stanford, Douglas; Streicher, Alexandre; Tezuka, Masaki

    2017-05-01

    We argue that the late time behavior of horizon fluctuations in large anti-de Sitter (AdS) black holes is governed by the random matrix dynamics characteristic of quantum chaotic systems. Our main tool is the Sachdev-Ye-Kitaev (SYK) model, which we use as a simple model of a black hole. We use an analytically continued partition function | Z( β + it)|2 as well as correlation functions as diagnostics. Using numerical techniques we establish random matrix behavior at late times. We determine the early time behavior exactly in a double scaling limit, giving us a plausible estimate for the crossover time to random matrix behavior. We use these ideas to formulate a conjecture about general large AdS black holes, like those dual to 4D super-Yang-Mills theory, giving a provisional estimate of the crossover time. We make some preliminary comments about challenges to understanding the late time dynamics from a bulk point of view.

  1. Lee–Wick black holes

    Directory of Open Access Journals (Sweden)

    Cosimo Bambi

    2017-01-01

    Full Text Available We derive and study an approximate static vacuum solution generated by a point-like source in a higher derivative gravitational theory with a pair of complex conjugate ghosts. The gravitational theory is local and characterized by a high derivative operator compatible with Lee–Wick unitarity. In particular, the tree-level two-point function only shows a pair of complex conjugate poles besides the massless spin two graviton. We show that singularity-free black holes exist when the mass of the source M exceeds a critical value Mcrit. For M>Mcrit the spacetime structure is characterized by an outer event horizon and an inner Cauchy horizon, while for M=Mcrit we have an extremal black hole with vanishing Hawking temperature. The evaporation process leads to a remnant that approaches the zero-temperature extremal black hole state in an infinite amount of time.

  2. The black hole quantum atmosphere

    Directory of Open Access Journals (Sweden)

    Ramit Dey

    2017-11-01

    Full Text Available Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate. Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan–Boltzmann law. In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor. We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about 4MG, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon. This long distance origin of Hawking radiation could have a profound impact on our understanding of the information and transplanckian problems.

  3. Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of a single row of holes with compound angle orientations producing film cooling at high blowing ratios. This film cooling configuration is important because similar arrangements are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 6d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 1.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes.

  4. Macular Hole in Behcet's Disease

    Directory of Open Access Journals (Sweden)

    Shwu-Jiuan Sheu

    2004-11-01

    Full Text Available Behcet's disease is an inflammatory disorder of unknown cause, characterized by recurrent oral aphthous ulcers, genital ulcers, uveitis, and skin lesions. Ocular involvement occurs in 60-80% of patients with Behcet's disease and presents as panuveitis in most cases. Posterior segment involvement may lead to irreversible alterations and significant vision loss. The development of a partial or full-thickness macular hole, though rarely reported, may cause serious vision loss. In this report, we present two cases of macular hole in the worse eye of bilateral cases of Behcet's disease, and discuss the possible mechanisms and management in such cases.

  5. Institutional Controls

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of institutional control data from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different...

  6. Institutional upbringing

    DEFF Research Database (Denmark)

    Gulløv, Eva

    2008-01-01

    current testing of Danish language fluency levels among pre-school minority children. Testing language skills marks and defines distinctions that reinforce images of deviance that, in turn, legitimize initiatives to enrol children, specifically minority children, in child care institutions....

  7. Institutional ethnography

    DEFF Research Database (Denmark)

    Lund, Rebecca; Tienari, Janne

    2016-01-01

    of managerial respondents. This leads to another bias in the study of M&As: an managerial one. These critiques are an important step in pinpointing some of the problematic aspects in the field, which we suggest can be part remedied by institutional ethnography developed by Dorothy Smith and her colleagues....... In institutional ethnography the notion of objectification is applied to describe research processes like those that have been found to dominate in scholarly work on M&As. In this chapter, we offer an outline of Smiths critique of objectification, elucidate how institutional ethnography seeks to address it......, and point to some of the problems in M&A studies identified through this lens. Finally, we argue why institutional ethnography, in comparison with other methods of inquiry, is particularly fruitful in the study of mergers and acquisitions....

  8. Institutional Investors

    DEFF Research Database (Denmark)

    Birkmose, Hanne Søndergaard; Strand, Therese

    Research Question/Issue: Institutional investors are facing increased pressure and threats of legislation from the European Union to abandon passive ownership strategies. This study investigates the prerequisites for – and potential dissimilarities in the practice of, active ownership among....../Policy Implications: Regulators should be aware of the impact by local governance mechanisms, and how shareholders react under different legal and practical prerequisites. The paper also highlights legal elements that differ between Denmark and Sweden, and which might affect institutional activism....

  9. Implementing DOIs for Oceanographic Satellite Data at PO.DAAC

    Science.gov (United States)

    Hausman, J.; Tauer, E.; Chung, N.; Chen, C.; Moroni, D. F.

    2013-12-01

    The Physical Oceanographic Distributed Active Archive Center (PO.DAAC) is NASA's archive for physical oceanographic satellite data. It distributes over 500 datasets from gravity, ocean wind, sea surface topography, sea ice, ocean currents, salinity, and sea surface temperature satellite missions. A dataset is a collection of granules/files that share the same mission/project, versioning, processing level, spatial, and temporal characteristics. The large number of datasets is partially due to the number of satellite missions, but mostly because a single satellite mission typically has multiple versions or even temporal and spatial resolutions of data. As a result, a user might mistake one dataset for a different dataset from the same satellite mission. Due to the PO.DAAC'S vast variety and volume of data and growing requirements to report dataset usage, it has begun implementing DOIs for the datasets it archives and distributes. However, this was not as simple as registering a name for a DOI and providing a URL. Before implementing DOIs multiple questions needed to be answered. What are the sponsor and end-user expectations regarding DOIs? At what level does a DOI get assigned (dataset, file/granule)? Do all data get a DOI, or only selected data? How do we create a DOI? How do we create landing pages and manage them? What changes need to be made to the data archive, life cycle policy and web portal to accommodate DOIs? What if the data also exists at another archive and a DOI already exists? How is a DOI included if the data were obtained via a subsetting tool? How does a researcher or author provide a unique, definitive reference (standard citation) for a given dataset? This presentation will discuss how these questions were answered through changes in policy, process, and system design. Implementing DOIs is not a trivial undertaking, but as DOIs are rapidly becoming the de facto approach, it is worth the effort. Researchers have historically referenced the source

  10. The Dissolved Oxygen Controversy: Reconciling Oceanographic Versus Geological Perspectives

    Science.gov (United States)

    Tyson, R. V.

    2003-12-01

    Geological models for the origin of black shales have invoked a preservative effect of dysoxia-anoxia for nearly a century, yet during the last 30 years some oceanographers have used modern sediment data to question and even deny the importance of dissolved oxygen. This schism over the origin of organic-rich sediments must be addressed and healed. With regard to modern sediment observations the problem appears to be how representative the data are, how and where oxygen hypotheses are tested (and against what expectations), and how the findings may have been extrapolated and generalised. It is increasingly clear that the total organic carbon (TOC) content of sediments is a classic multivariate problem where input (productivity), preservation, and inorganic dilution must all be considered simultaneously. The most common low oxygen environments in the modern ocean are oxygen minimum zones (OMZ), but these are also characterised by high productivities, high sedimentation rates, and generally high preservation, and are thus a very poor place to isolate the role of oxygen. Furthermore, OMZ studies have used a comparative analysis of TOC above, within, and below the OMZ, where the latter is defined only by local minima, not oxygen values considered likely to have a significant effect on benthos or geochemical preservation. Sometimes hypotheses have been constructed based on data from only a narrow (suboxic-dysoxic) oxygen range, fully oxic regimes, or areas too strongly influenced by grain size. The organic-rich nature of modern deep Black Sea sediments has also been denied, but seems indisputable relative to similar oxic regimes. A critique and analysis of the available modern data (increasing all the time, but still limited) suggest that the oceanographic view that oxygen is not important is impossible to sustain as a generality, indeed a statistical non-linear effect can be identified by multiple regression analysis. In many modern settings other factors are definitely

  11. Physical Oceanographic Real-Time System (PORTS) (Invited)

    Science.gov (United States)

    Wright, D.

    2013-12-01

    The 1999 Assessment of U.S. Marine Transportation System report to Congress noted that the greatest safety concern voiced by the maritime community was the availability of timely, accurate, and reliable navigation information, including real time environment data. Real time oceanographic and meteorological data, along with other navigation tools, gives the mariner a good situational understanding of their often challenging operational environment, to make the best safety of life and property decisions. The National Oceanic and Atmospheric Administration's (NOAA) Physical Oceanographic Real Time System (PORTS) was developed in response to accidents like the Sunshine Skyway Bridge collision in Tampa, FL in 1980, where the lack of accurate, reliable and timely environmental conditions directly contributed to an accident that resulted in a high loss of life and property. Since that time, PORTS has expanded to over 20 locations around the country, and its capabilities have been continually expanded and improved as well. PORTS primary mission is to prevent maritime accidents. Preventing an accident from occurring is the most cost effective approach and the best way to avoid damage to the environment. When accidents do occur, PORTS data is used to improve the effectiveness of response efforts by providing input for trajectory models and real time conditions for response efforts. However, benefits derived from PORTS go well beyond navigation safety. Another large benefit to the local maritime community is potential efficiencies in optimizing use of the existing water column. PORTS provides information that can be used to make economic decisions to add or offload cargo to a vessel and/or to maintain or adjust transit schedules based upon availability of water depth, strength/timing of tidal currents, and other conditions. PORTS data also helps improve and validate local National Weather Service marine weather forecasts. There are many benefits beyond the local maritime

  12. Improved Black Hole Fireworks: Asymmetric Black-Hole-to-White-Hole Tunneling Scenario

    CERN Document Server

    De Lorenzo, Tommaso

    2015-01-01

    A new scenario for gravitational collapse has been recently proposed by Haggard and Rovelli. Presenting the model under the name of black hole fireworks, they claimed that the accumulation of quantum gravitational effects outside the horizon can cause the tunneling of geometry from a black hole to a white hole, allowing a bounce of the collapsing star which can eventually go back to infinity. In this paper we discuss the instabilities of this model and propose a simple minimal modification which eliminates them, as well as other related instabilities discussed in the literature. The new scenario is a time-asymmetric version of the original model with a time-scale for the final explosion that is shorter than m log m in Planck units. Our analysis highlights the importance of irreversibility in gravitational collapse which, in turn, uncovers important issues that cannot be addressed in detail without a full quantum gravity treatment.

  13. Black Holes and Exotic Spinors

    Directory of Open Access Journals (Sweden)

    J. M. Hoff da Silva

    2016-05-01

    Full Text Available Exotic spin structures are non-trivial liftings, of the orthogonal bundle to the spin bundle, on orientable manifolds that admit spin structures according to the celebrated Geroch theorem. Exotic spin structures play a role of paramount importance in different areas of physics, from quantum field theory, in particular at Planck length scales, to gravity, and in cosmological scales. Here, we introduce an in-depth panorama in this field, providing black hole physics as the fount of spacetime exoticness. Black holes are then studied as the generators of a non-trivial topology that also can correspond to some inequivalent spin structure. Moreover, we investigate exotic spinor fields in this context and the way exotic spinor fields branch new physics. We also calculate the tunneling probability of exotic fermions across a Kerr-Sen black hole, showing that the exotic term does affect the tunneling probability, altering the black hole evaporation rate. Finally we show that it complies with the Hawking temperature universal law.

  14. Black Holes in Our Universe

    Indian Academy of Sciences (India)

    Abstract. Current technologies have enabled glimpses at the many facetsof black holes, which we know to be plentiful in our cosmos.A panoramic view of the evidence for them is presented hereacross the large range of masses that they span.

  15. Extremal Higher Spin Black Holes

    NARCIS (Netherlands)

    Bañados, M.; Castro, A.; Faraggi, A.; Jottar, J.I.

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal

  16. From Pinholes to Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  17. Rotating black hole and quintessence

    CERN Document Server

    Ghosh, Sushant G

    2015-01-01

    We discuss spherically symmetric exact solutions of the Einstein equations for quintessential matter surrounding a black hole (BH), which has additional parameters ($\\alpha$ and $\\omega$) due to the quintessential matter, apart from the mass ($M$). In turn, we employ the Newman\\(-\\)Janis complex transformation to this spherical quintessence BH solution and present a rotating counterpart that is identified, for $\\alpha=-e^2 \

  18. 'Black holes': escaping the void.

    Science.gov (United States)

    Waldron, Sharn

    2013-02-01

    The 'black hole' is a metaphor for a reality in the psyche of many individuals who have experienced complex trauma in infancy and early childhood. The 'black hole' has been created by an absence of the object, the (m)other, so there is no internalized object, no (m)other in the psyche. Rather, there is a 'black hole' where the object should be, but the infant is drawn to it, trapped by it because of an intrinsic, instinctive need for a 'real object', an internalized (m)other. Without this, the infant cannot develop. It is only the presence of a real object that can generate the essential gravity necessary to draw the core of the self that is still in an undeveloped state from deep within the abyss. It is the moving towards a real object, a (m)other, that relativizes the absolute power of the black hole and begins a reformation of its essence within the psyche. © 2013, The Society of Analytical Psychology.

  19. Black Hole Macro-Quantumness

    CERN Document Server

    Dvali, Gia

    2014-01-01

    It is a common wisdom that properties of macroscopic bodies are well described by (semi)classical physics. As we have suggested this wisdom is not applicable to black holes. Despite being macroscopic, black holes are quantum objects. They represent Bose-Einstein condensates of N-soft gravitons at the quantum critical point, where N Bogoliubov modes become gapless. As a result, physics governing arbitrarily-large black holes (e.g., of galactic size) is a quantum physics of the collective Bogoiliubov modes. This fact introduces a new intrinsically-quantum corrections in form of 1/N, as opposed to exp(-N). These corrections are unaccounted by the usual semiclassical expansion in h and cannot be recast in form of a quantum back-reaction to classical metric. Instead the metric itself becomes an approximate entity. These 1/N corrections abolish the presumed properties of black holes, such as non existence of hair, and are the key to nullifying the so-called information paradox.

  20. Rapid Deployment of a RESTful Service for Oceanographic Research Cruises

    Science.gov (United States)

    Fu, Linyun; Arko, Robert; Leadbetter, Adam

    2014-05-01

    The Ocean Data Interoperability Platform (ODIP) seeks to increase data sharing across scientific domains and international boundaries, by providing a forum to harmonize diverse regional data systems. ODIP participants from the US include the Rolling Deck to Repository (R2R) program, whose mission is to capture, catalog, and describe the underway/environmental sensor data from US oceanographic research vessels and submit the data to public long-term archives. R2R publishes information online as Linked Open Data, making it widely available using Semantic Web standards. Each vessel, sensor, cruise, dataset, person, organization, funding award, log, report, etc, has a Uniform Resource Identifier (URI). Complex queries that federate results from other data providers are supported, using the SPARQL query language. To facilitate interoperability, R2R uses controlled vocabularies developed collaboratively by the science community (eg. SeaDataNet device categories) and published online by the NERC Vocabulary Server (NVS). In response to user feedback, we are developing a standard programming interface (API) and Web portal for R2R's Linked Open Data. The API provides a set of simple REST-type URLs that are translated on-the-fly into SPARQL queries, and supports common output formats (eg. JSON). We will demonstrate an implementation based on the Epimorphics Linked Data API (ELDA) open-source Java package. Our experience shows that constructing a simple portal with limited schema elements in this way can significantly reduce development time and maintenance complexity.

  1. Development of a 300 L Calibration Bath for Oceanographic Thermometers

    Science.gov (United States)

    Baba, S.; Yamazawa, K.; Nakano, T.; Saito, I.; Tamba, J.; Wakimoto, T.; Katoh, K.

    2017-11-01

    The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been developing a 300 L calibration bath to calibrate 24 oceanographic thermometers (OT) simultaneously and thereby reduce the calibration work load necessary to service more than 180 OT every year. This study investigated characteristics of the developed 300 L calibration bath using a SBE 3plus thermometer produced by an OT manufacturer. We also used 11 thermistor thermometers that were calibrated to be traceable to the international temperature scale of 1990 (ITS-90) within 1 mK of standard uncertainty through collaboration of JAMSTEC and NMIJ/AIST. Results show that the time stability of temperature of the developed bath was within ± 1 mK. Furthermore, the temperature uniformity was ± 1.3 mK. The expanded uncertainty (k=2) components for the characteristics of the developed 300 L calibration bath were estimated as 2.9 mK, which is much less than the value of 10 mK: the required specification for uncertainty of calibration for the OT. These results demonstrated the utility of this 300 L calibration bath as a device for use with a new calibration system.

  2. Application of Open Source Technologies for Oceanographic Data Analysis

    Science.gov (United States)

    Huang, T.; Gangl, M.; Quach, N. T.; Wilson, B. D.; Chang, G.; Armstrong, E. M.; Chin, T. M.; Greguska, F.

    2015-12-01

    NEXUS is a data-intensive analysis solution developed with a new approach for handling science data that enables large-scale data analysis by leveraging open source technologies such as Apache Cassandra, Apache Spark, Apache Solr, and Webification. NEXUS has been selected to provide on-the-fly time-series and histogram generation for the Soil Moisture Active Passive (SMAP) mission for Level 2 and Level 3 Active, Passive, and Active Passive products. It also provides an on-the-fly data subsetting capability. NEXUS is designed to scale horizontally, enabling it to handle massive amounts of data in parallel. It takes a new approach on managing time and geo-referenced array data by dividing data artifacts into chunks and stores them in an industry-standard, horizontally scaled NoSQL database. This approach enables the development of scalable data analysis services that can infuse and leverage the elastic computing infrastructure of the Cloud. It is equipped with a high-performance geospatial and indexed data search solution, coupled with a high-performance data Webification solution free from file I/O bottlenecks, as well as a high-performance, in-memory data analysis engine. In this talk, we will focus on the recently funded AIST 2014 project by using NEXUS as the core for oceanographic anomaly detection service and web portal. We call it, OceanXtremes

  3. Taking the Pulse of a Black Hole System

    Science.gov (United States)

    2011-01-01

    amount of energy into its surroundings," said Neilsen. "All that energy has profound consequences for the disk, even very far from the black hole." Changes in the X-ray spectrum observed by RXTE during each heartbeat reveal that the inner region of the disk, at only a few times the radius of the black hole's event horizon, emits enough radiation to push material away from the black hole. Eventually the disk gets so bright and so hot that it essentially disintegrates and plunges towards the black hole. Then the cycle begins again. "This behavior is a clear and startling demonstration of the power of radiation in the fight against gravity," said co-author Ron Remillard of the Massachusetts Institute of Technology. "During the heartbeat state, radiation prevents the black hole from ingesting as much material as it would otherwise." Neilsen and his colleagues estimated that the rate at which material falls onto the black hole changes by about a factor of ten during each cycle, with the maximum rate coinciding with the X-ray pulse. Between pulses, the inner part of the disk refills from material farther away from the black hole. The astronomers also used Chandra's high-resolution spectrograph to study the effects of this heartbeat variation on regions of the disk very far from the black hole, at distances of about 100,000 to a million times the radius of the event horizon. By analyzing the Chandra spectrum, they found a very strong wind being driven away from the outer parts of the disk. The wind changed significantly in just 5 seconds, nearly 100 times faster than has ever been seen in a wind from a stellar-mass black hole. The researchers concluded that the strong X-ray pulse from the inner disk must heat the outer disk. This heating process launches a wind, so that each new pulse drives more wind from the disk. The rate of mass expelled in this wind is remarkably high, as much as 25 times the maximum rate at which matter falls onto the black hole. "All that energy blows

  4. Supersymmetric black holes and Freudenthal duality

    Science.gov (United States)

    Marrani, Alessio; Mandal, Taniya; Tripathy, Prasanta K.

    2017-07-01

    We study the effect of Freudenthal duality on supersymmetric extremal black hole attractors in 𝒩 = 2, D = 4 ungauged supergravity. Freudenthal duality acts on the dyonic black hole charges as an anti-involution which keeps the black hole entropy and the critical points of the effective black hole potential invariant. We analyze its effect on the recently discovered distinct, mutually exclusive phases of axionic supersymmetric black holes, related to the existence of nontrivial involutory constant matrices. In particular, we consider a supersymmetric D0 - D4 - D6 black hole and we explicitly Freudenthal-map it to a supersymmetric D0 - D2 - D4 - D6 black hole. We thus show that the charge representation space of a supersymmetric D0 - D2 - D4 - D6 black hole also contains mutually exclusive domains.

  5. Spin distribution of primordial black holes

    Science.gov (United States)

    Chiba, Takeshi; Yokoyama, Shuichiro

    2017-08-01

    We estimate the spin distribution of primordial black holes based on the recent study of the critical phenomena in the gravitational collapse of a rotating radiation fluid. We find that primordial black holes are mostly slowly rotating.

  6. Implementing black hole as efficient power plant

    CERN Document Server

    Wei, Shao-Wen

    2016-01-01

    Treating the black hole molecules as working substance and considering its phase structure, we study the black hole heat engine by a charged anti-de Sitter black hole. In the reduced temperature-entropy chart, it is found that the work, heat, and efficiency of the engine are independent of the black hole charge. Applying the Rankine cycle with or without a back pressure mechanism to the black hole heat engine, the efficiency is numerically solved. The result shows that the black hole engine working along the Rankine cycle with a back pressure mechanism has a higher efficiency. This provides a novel and efficient mechanism to produce the useful mechanical work with black hole, and such heat engine may act as a possible energy source for the high energy astrophysical phenomena near the black hole.

  7. Mass Inflation in the Loop Black Hole

    CERN Document Server

    Brown, Eric G; Modesto, Leonardo

    2011-01-01

    In classical general relativity the Cauchy horizon within a two-horizon black hole is unstable via a phenomenon known as mass inflation, in which the mass parameter (and the spacetime curvature) of the black hole diverges at the Cauchy horizon. Here we study this effect for loop black holes -- quantum gravitationally corrected black holes from loop quantum gravity -- whose construction alleviates the $r=0$ singularity present in their classical counterparts. We use a simplified model of mass inflation, which makes use of the generalized DTR relation, to conclude that the Cauchy horizon of loop black holes indeed results in a curvature singularity similar to that found in classical black holes. The DTR relation is of particular utility in the loop black hole because it does not directly rely upon Einstein's field equations. We elucidate some of the interesting and counterintuitive properties of the loop black hole, and corroborate our results using an alternate model of mass inflation due to Ori.

  8. Foundations of Black Hole Accretion Disk Theory

    National Research Council Canada - National Science Library

    Abramowicz, Marek A; Fragile, P. Chris

    2013-01-01

    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves...

  9. Extremal higher spin black holes

    Energy Technology Data Exchange (ETDEWEB)

    Bañados, Máximo [Instituto de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile); Castro, Alejandra [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, Postbus 94485, Amsterdam, 1090 GL (Netherlands); Faraggi, Alberto [Instituto de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile); Jottar, Juan I. [Institut für Theoretische Physik, ETH Zürich,Zürich, CH-8093 (Switzerland)

    2016-04-13

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require supersymmetry, we exemplify its consequences in the context of sl(3|2)⊕sl(3|2) Chern-Simons theory and show that, as usual, not all extremal solutions preserve supersymmetries. Remarkably, we find in addition that the higher spin setup allows for non-extremal supersymmetric black hole solutions. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2)⊕sl(3|2) Chern-Simons theory and two-dimensional CFTs with W{sub (3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W{sub (3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  10. A New Cosmological Model: Black Hole Universe

    OpenAIRE

    Zhang T. X.

    2009-01-01

    A new cosmological model called black hole universe is proposed. According to this model, the universe originated from a hot star-like black hole with several solar masses, and gradually grew up through a supermassive black hole with billion solar masses to the present state with hundred billion-trillion solar masses by accreting ambient mate- rials and merging with other black holes. The entire space is structured with infinite layers hierarchically. The innermost three laye...

  11. Institutional Awareness

    DEFF Research Database (Denmark)

    Ahlvik, Carina; Boxenbaum, Eva

    Drawing on dual-process theory and mindfulness research this article sets out to shed light on the conditions that need to be met to create “a reflexive shift in consciousness” argued to be a key foundational mechanism for agency in institutional theory. Although past research has identified diff...... in consciousness to emerge and argue for how the varying levels of mindfulness in the form of internal and external awareness may manifest as distinct responses to the institutional environment the actor is embedded in....

  12. Compensating Scientism through "The Black Hole."

    Science.gov (United States)

    Roth, Lane

    The focal image of the film "The Black Hole" functions as a visual metaphor for the sacred, order, unity, and eternal time. The black hole is a symbol that unites the antinomic pairs of conscious/unconscious, water/fire, immersion/emersion, death/rebirth, and hell/heaven. The black hole is further associated with the quest for…

  13. Black Hole Monodromy and Conformal Field Theory

    NARCIS (Netherlands)

    Castro, A.; Lapan, J.M.; Maloney, A.; Rodriguez, M.J.

    2013-01-01

    The analytic structure of solutions to the Klein-Gordon equation in a black hole background, as represented by monodromy data, is intimately related to black hole thermodynamics. It encodes the "hidden conformal symmetry" of a nonextremal black hole, and it explains why features of the inner event

  14. On Quantum Contributions to Black Hole Growth

    NARCIS (Netherlands)

    Spaans, M.

    2013-01-01

    The effects of Wheeler’s quantum foam on black hole growth are explored from an astrophysical per- spective. Quantum fluctuations in the form of mini (10−5 g) black holes can couple to macroscopic black holes and allow the latter to grow exponentially in mass on a time scale of 109 years.

  15. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Abstract. Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the con- jecture that the primordial ...

  16. On black holes and gravitational waves

    CERN Document Server

    Loinger, Angelo

    2002-01-01

    Black holes and gravitational waves are theoretical entities of today astrophysics. Various observed phenomena have been associated with the concept of black hole ; until now, nobody has detected gravitational waves. The essays contained in this book aim at showing that the concept of black holes arises from a misinterpretation of general relativity and that gravitational waves cannot exist.

  17. Extremal black holes in N=2 supergravity

    NARCIS (Netherlands)

    Katmadas, S.

    2011-01-01

    An explanation for the entropy of black holes has been an outstanding problem in recent decades. A special case where this is possible is that of extremal black holes in N=2 supergravity in four and five dimensions. The best developed case is for black holes preserving some supersymmetry (BPS),

  18. Chandra Catches "Piranha" Black Holes

    Science.gov (United States)

    2007-07-01

    Supermassive black holes have been discovered to grow more rapidly in young galaxy clusters, according to new results from NASA's Chandra X-ray Observatory. These "fast-track" supermassive black holes can have a big influence on the galaxies and clusters that they live in. Using Chandra, scientists surveyed a sample of clusters and counted the fraction of galaxies with rapidly growing supermassive black holes, known as active galactic nuclei (or AGN). The data show, for the first time, that younger, more distant galaxy clusters contained far more AGN than older, nearby ones. Galaxy clusters are some of the largest structures in the Universe, consisting of many individual galaxies, a few of which contain AGN. Earlier in the history of the universe, these galaxies contained a lot more gas for star formation and black hole growth than galaxies in clusters do today. This fuel allows the young cluster black holes to grow much more rapidly than their counterparts in nearby clusters. Illustration of Active Galactic Nucleus Illustration of Active Galactic Nucleus "The black holes in these early clusters are like piranha in a very well-fed aquarium," said Jason Eastman of Ohio State University (OSU) and first author of this study. "It's not that they beat out each other for food, rather there was so much that all of the piranha were able to really thrive and grow quickly." The team used Chandra to determine the fraction of AGN in four different galaxy clusters at large distances, when the Universe was about 58% of its current age. Then they compared this value to the fraction found in more nearby clusters, those about 82% of the Universe's current age. The result was the more distant clusters contained about 20 times more AGN than the less distant sample. AGN outside clusters are also more common when the Universe is younger, but only by factors of two or three over the same age span. "It's been predicted that there would be fast-track black holes in clusters, but we never

  19. Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

    OpenAIRE

    Takahashi, Rohta

    2004-01-01

    Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin paramete...

  20. The stable problem of the black-hole connected region in the Schwarzschild black hole

    OpenAIRE

    Tian, Guihua

    2005-01-01

    The stability of the Schwarzschild black hole is studied. Using the Painlev\\'{e} coordinate, our region can be defined as the black-hole-connected region(r>2m, see text) of the Schwarzschild black hole or the white-hole-connected region(r>2m, see text) of the Schwarzschild black hole. We study the stable problems of the black-hole-connected region. The conclusions are: (1) in the black-hole-connected region, the initially regular perturbation fields must have real frequency or complex frequen...

  1. Oceanography for the Visually Impaired

    Science.gov (United States)

    Fraser, Kate

    2008-01-01

    Amy Bower is a physical oceanographer and senior scientist at the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts--she has also been legally blind for 14 years. Through her partnership with the Perkins School for the Blind in Watertown, Massachusetts, the oldest K-12 school for the visually impaired in the United States,…

  2. Institutional Assessment

    International Development Research Centre (IDRC) Digital Library (Canada)

    Organizational incentives refer to the way an organization's system of rewards and punishments either encourages or discourages behaviours – in the case of research institutions, productivity and creativity. Incentives are important to individual research careers and to overall organizational success and can help ...

  3. European Institutions?

    NARCIS (Netherlands)

    Meacham, Darian

    2016-01-01

    The aim of this article is to sketch a phenomenological theory of political institutions and to apply it to some objections and questions raised by Pierre Manent about the project of the European Union and more specifically the question of “European Construction”, i.e. what is the aim of the

  4. Spectral Hole Burning via Kerr Nonlinearity

    Science.gov (United States)

    Khan, Anwar Ali; Abdul Jabar, M. S.; Jalaluddin, M.; Bacha, Bakht Amin; Iftikhar, Ahmad

    2015-10-01

    Spectral hole burning is investigated in an optical medium in the presence of Doppler broadening and Kerr nonlinearity. The Kerr nonlinearity generates coherent hole burning in the absorption spectrum. The higher order Kerr nonlinearity enhances the typical lamb dip of the hole. Normal dispersion in the hole burning region while Steep anomalous dispersion between the two hole burning regions also enhances with higher order Kerr effect. A large phase shift creates large delay or advancement in the pulse propagation while no distortion is observed in the pulse. These results provide significant steps to improve optical memory, telecom devices, preservation of information and image quality. Supported by Higher Education Commission (HEC) of Pakistan

  5. Black hole thermodynamics with conical defects

    Science.gov (United States)

    Appels, Michael; Gregory, Ruth; Kubizňák, David

    2017-05-01

    Recently we have shown [1] how to formulate a thermodynamic first law for a single (charged) accelerated black hole in AdS space by fixing the conical deficit angles present in the spacetime. Here we show how to generalise this result, formulating thermodynamics for black holes with varying conical deficits. We derive a new potential for the varying tension defects: the thermodynamic length, both for accelerating and static black holes. We discuss possible physical processes in which the tension of a string ending on a black hole might vary, and also map out the thermodynamic phase space of accelerating black holes and explore their critical phenomena.

  6. Black-hole creation in quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Chao, Wu [Rome, Univ. `La Sapienza` (Italy). International Center for Relativistic Astrophysics]|[Specola Vaticana, Vatican City State (Vatican City State, Holy See)

    1997-11-01

    It is proven that the probability of a black hole created from the de Sitter space-time background, at the Wkb level, is the exponential of one quarter of the sum of the black hole and cosmological horizon areas, or the total entropy of the universe. This is true not only for the spherically symmetric cases of the Schwarzschild or Reissner-Nordstroem black holes, but also for the rotating cases of the Kerr black hole and the rotating charged case of the Newman black hole. The de Sitter metric is the most probable evolution at the Planckian era of the universe.

  7. Oceanographic gradients and seabird prey community dynamics in glacial fjords

    Science.gov (United States)

    Arimitsu, Mayumi L.; Piatt, John F.; Madison, Erica N.; Conaway, Jeff; Hillgruber, N.

    2012-01-01

    Glacial fjord habitats are undergoing rapid change as a result of contemporary global warming, yet little is known about how glaciers influence marine ecosystems. These ecosystems provide important feeding, breeding and rearing grounds for a wide variety of marine organisms, including seabirds of management concern. To characterize ocean conditions and marine food webs near tidewater glaciers, we conducted monthly surveys of oceanographic variables, plankton, fish and seabirds in Kenai Fjords, Alaska, from June to August of 2007 and 2008. We also measured tidal current velocities near glacial features. We found high sediment load from glacial river runoff played a major role in structuring the fjord marine ecosystem. Submerged moraines (sills) isolated cool, fresh, stratified and silt-laden inner fjord habitats from oceanic influence. Near tidewater glaciers, surface layers of turbid glacial runoff limited availability of light to phytoplankton, but macrozooplankton were abundant in surface waters, perhaps due to the absence of a photic cue for diel migration. Fish and zooplankton community structure varied along an increasing temperature gradient throughout the summer. Acoustic measurements indicated that low density patches of fish and zooplankton were available in the surface waters near glacial river outflows. This is the foraging habitat occupied most by Kittlitz's murrelet (Brachyramphus brevirostris), a rare seabird that appears to be specialized for life in glacially influenced environments. Kittlitz's murrelets were associated with floating glacial ice, and they were more likely to occur near glaciers, in deeper water, and in areas with high acoustic backscatter. Kittlitz's murrelet at-sea distribution was limited to areas influenced by turbid glacial outflows, and where prey was concentrated near the surface in waters with low light penetration. Tidewater glaciers impart unique hydrographic characteristics that influence marine plankton and fish

  8. Water column methanotrophy controlled by a rapid oceanographic switch

    Science.gov (United States)

    Steinle, Lea; Graves, Carolyn; Treude, Tina; Biastoch, Arne; Ferré, Bénédicte; Bussmann, Ingeborg; Berndt, Christian; Krastel, Sebastian; James, Rachael H.; Behrens, Erik; Böning, Claus W.; Greinert, Jens; Sapart, Célia-Julia; Sommer, Stefan; Lehmann, Moritz F.; Niemann, Helge

    2015-04-01

    Large amounts of the greenhouse gas methane are released from the seabed to the water column where it may be consumed by aerobic methanotrophic bacteria. This microbial filter is consequently the last marine sink for methane before its liberation into the atmosphere. The size and activity of methanotrophic communities, which determine the capacity of the water column methane filter, are thought to be mainly controlled by nutrient and redox dynamics, but little is known about the effects of ocean currents. Here we show that cold bottom water at methane seeps west of Svalbard, containing a large number of aerobic methanotrophs, was rapidly displaced by warmer water with a considerably smaller methanotrophic community. This community replacement led to a reduction of methane oxidation rates of 60 % and was independent of methane input. Measurements of temperature and salinity, combined with the output of a high-resolution ocean/sea-ice simulation model (VIKING20) showed that this water mass exchange was caused by short-term variations of the West Spitsbergen Current (WSC), which is characterized by two principal modes: The warm core of the WSC either flows along the continental shelf break and thus above the methane seeps (nearshore mode), or it meanders offshore thereby entraining colder shelf water, which then flows over the seeps (offshore mode). We could link the larger community to the colder shelf water during the offshore mode, and the smaller community and lower methane oxidation rates to the presence of the warmer WSC water above the seeps. As a result, the meandering of the WSC can be considered as an oceanographic switch severely reducing methanotrophic activity in the water column. Output from the ORCA12 model showed that strong and fluctuating bottom currents are common features at methane seep systems. We thus argue that the variability of physical water mass transport is a globally important control on the distribution and abundance of methanotrophs and

  9. Antenna Pattern Measurements for Oceanographic Radars Using Small Aerial Drones

    Science.gov (United States)

    Washburn, L.; Romero, E.; Johnson, C.; Emery, B.; Gotschalk, C.

    2016-12-01

    We describe a method employing small, quadrotor drone aircraft for antenna pattern measurements (APMs) of high-frequency (HF) oceanographic radars used for observing ocean surface currents. During APMs, the drones carry small radio signal sources in circular arcs centered on receive antenna arrays at HF radar sites, similarly to conventional boat-based APMs. Previous studies have shown that accurate surface current measurements using HF radar require APMs. In the absence of APMs so-called "ideal" antenna patterns are assumed and these can differ substantially from measured patterns. Typically APMs are obtained using small research vessels, an expensive procedure requiring sea-going technicians, a vessel, and other equipment necessary to support small boat operations. Adverse sea conditions and obstacles in the water can limit the ability of small vessels to conduct APMs. In contrast, drones can successfully conduct APMs at much lower cost and in a broader range of sea states with comparable accuracy. Drone-based patterns can extend farther shoreward since they are not affected by the surf zone and thereby expand the range of bearings over which APMs are conducted. We describe recent progress in the use of drones for APMs including: (1) evaluation of the accuracy APM flight trajectories; (2) estimates of radial velocity components due to deviation of flight paths from circular arcs; and (3) the effects of altitude with respect to ground wave versus direct signal propagation. Use of drones simplifies APMs and it is hoped that this will lead to more frequent APMs and improved surface current measurements from HF radar networks.

  10. The Oceanographic Multipurpose Software Environment (OMUSE v1.0)

    Science.gov (United States)

    Pelupessy, Inti; van Werkhoven, Ben; van Elteren, Arjen; Viebahn, Jan; Candy, Adam; Portegies Zwart, Simon; Dijkstra, Henk

    2017-08-01

    In this paper we present the Oceanographic Multipurpose Software Environment (OMUSE). OMUSE aims to provide a homogeneous environment for existing or newly developed numerical ocean simulation codes, simplifying their use and deployment. In this way, numerical experiments that combine ocean models representing different physics or spanning different ranges of physical scales can be easily designed. Rapid development of simulation models is made possible through the creation of simple high-level scripts. The low-level core of the abstraction in OMUSE is designed to deploy these simulations efficiently on heterogeneous high-performance computing resources. Cross-verification of simulation models with different codes and numerical methods is facilitated by the unified interface that OMUSE provides. Reproducibility in numerical experiments is fostered by allowing complex numerical experiments to be expressed in portable scripts that conform to a common OMUSE interface. Here, we present the design of OMUSE as well as the modules and model components currently included, which range from a simple conceptual quasi-geostrophic solver to the global circulation model POP (Parallel Ocean Program). The uniform access to the codes' simulation state and the extensive automation of data transfer and conversion operations aids the implementation of model couplings. We discuss the types of couplings that can be implemented using OMUSE. We also present example applications that demonstrate the straightforward model initialization and the concurrent use of data analysis tools on a running model. We give examples of multiscale and multiphysics simulations by embedding a regional ocean model into a global ocean model and by coupling a surface wave propagation model with a coastal circulation model.

  11. The Oceanographic Multipurpose Software Environment (OMUSE v1.0

    Directory of Open Access Journals (Sweden)

    I. Pelupessy

    2017-08-01

    Full Text Available In this paper we present the Oceanographic Multipurpose Software Environment (OMUSE. OMUSE aims to provide a homogeneous environment for existing or newly developed numerical ocean simulation codes, simplifying their use and deployment. In this way, numerical experiments that combine ocean models representing different physics or spanning different ranges of physical scales can be easily designed. Rapid development of simulation models is made possible through the creation of simple high-level scripts. The low-level core of the abstraction in OMUSE is designed to deploy these simulations efficiently on heterogeneous high-performance computing resources. Cross-verification of simulation models with different codes and numerical methods is facilitated by the unified interface that OMUSE provides. Reproducibility in numerical experiments is fostered by allowing complex numerical experiments to be expressed in portable scripts that conform to a common OMUSE interface. Here, we present the design of OMUSE as well as the modules and model components currently included, which range from a simple conceptual quasi-geostrophic solver to the global circulation model POP (Parallel Ocean Program. The uniform access to the codes' simulation state and the extensive automation of data transfer and conversion operations aids the implementation of model couplings. We discuss the types of couplings that can be implemented using OMUSE. We also present example applications that demonstrate the straightforward model initialization and the concurrent use of data analysis tools on a running model. We give examples of multiscale and multiphysics simulations by embedding a regional ocean model into a global ocean model and by coupling a surface wave propagation model with a coastal circulation model.

  12. New applications for autonomous aerial vehicles in coastal oceanographic research

    Science.gov (United States)

    Washburn, L.; Romero, E.; Johnson, C.; Emery, B. M.

    2016-02-01

    We describe the use of small, autonomous aerial vehicles (AAVs) for two applications to improve observations of the coastal ocean. Two types of aerial vehicles are used in these applications: small, fixed-wing airplanes and quad-rotor vehicles constructed in our laboratory. A key characteristic of these vehicles is their ability to accurately follow prescribed flight trajectories. The first application is a new method using AAVs for antenna pattern measurements (APMs) of high frequency (HF), oceanographic radars. HF radar is arguably the best observational approach for mapping coastal surface currents. Accurate surface current measurements by HF radar require APMs and these are typically made from small vessels carrying radio transponders in arcs around individual radar sites. This is costly because it requires sea-going technicians, a vessel, and other equipment for small boat operations. Adverse sea conditions often limit small vessels in conducting APMs. AAVs can conduct APMs at much lower cost and in a broader range of sea states with comparable accuracy. The AAVs carry small radio-frequency signal sources designed and fabricated in our laboratory. AAV-based patterns extend farther shoreward through the surf zone. This increases the range of bearings over which APMs are determined. Use of AAVs also allows more frequent APMs. The second application is water sample collection by AAVs for calibrating time series obtained from newly available pH sensors. Influx of low pH waters into subtidal and intertidal habitats is an emerging threat to coastal ecosystems. Acquisition of bottle samples for calibrating these sensors is important for accurate pH measurement. We have developed a lightweight sampling bottle as a payload for quad-rotor AAVs to collect water samples near moored pH sensors. The use of quad-rotor AAVs allows collection of numerous samples during sensor deployments so the effects of sensor drift and bio-fouling can be quantified.

  13. From Black Holes to Quivers

    CERN Document Server

    Manschot, Jan; Sen, Ashoke

    2012-01-01

    Middle cohomology states on the Higgs branch of supersymmetric quiver quantum mechanics - also known as pure Higgs states - have recently emerged as possible microscopic candidates for single-centered black hole micro-states, as they carry zero angular momentum and appear to be robust under wall-crossing. Using the connection between quiver quantum mechanics on the Coulomb branch and the quantum mechanics of multi-centered black holes, we propose a general algorithm for reconstructing the full moduli-dependent cohomology of the moduli space of an arbitrary quiver, in terms of the BPS invariants of the pure Higgs states. We analyze many examples of quivers with loops, including all cyclic Abelian quivers and several examples with two loops or non-Abelian gauge groups, and provide supporting evidence for this proposal. We also develop methods to count pure Higgs states directly.

  14. Black hole with quantum potential

    Directory of Open Access Journals (Sweden)

    Ahmed Farag Ali

    2016-08-01

    Full Text Available In this work, we investigate black hole (BH physics in the context of quantum corrections. These quantum corrections were introduced recently by replacing classical geodesics with quantal (Bohmian trajectories and hence form a quantum Raychaudhuri equation (QRE. From the QRE, we derive a modified Schwarzschild metric, and use that metric to investigate BH singularity and thermodynamics. We find that these quantum corrections change the picture of Hawking radiation greatly when the size of BH approaches the Planck scale. They prevent the BH from total evaporation, predicting the existence of a quantum BH remnant, which may introduce a possible resolution for the catastrophic behavior of Hawking radiation as the BH mass approaches zero. Those corrections also turn the spacelike singularity of the black hole to be timelike, and hence this may ameliorate the information loss problem.

  15. Black hole with quantum potential

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed Farag, E-mail: ahmed.ali@fsc.bu.edu.eg [Department of Physics, Faculty of Science, Benha University, Benha 13518 (Egypt); Khalil, Mohammed M., E-mail: moh.m.khalil@gmail.com [Department of Electrical Engineering, Alexandria University, Alexandria 12544 (Egypt)

    2016-08-15

    In this work, we investigate black hole (BH) physics in the context of quantum corrections. These quantum corrections were introduced recently by replacing classical geodesics with quantal (Bohmian) trajectories and hence form a quantum Raychaudhuri equation (QRE). From the QRE, we derive a modified Schwarzschild metric, and use that metric to investigate BH singularity and thermodynamics. We find that these quantum corrections change the picture of Hawking radiation greatly when the size of BH approaches the Planck scale. They prevent the BH from total evaporation, predicting the existence of a quantum BH remnant, which may introduce a possible resolution for the catastrophic behavior of Hawking radiation as the BH mass approaches zero. Those corrections also turn the spacelike singularity of the black hole to be timelike, and hence this may ameliorate the information loss problem.

  16. "Twisted" black holes are unphysical

    CERN Document Server

    Gray, Finnian; Schuster, Sebastian; Visser, Matt

    2016-01-01

    So-called "twisted" black holes have recently been proposed by Zhang (1609.09721 [gr-qc]), and further considered by Chen and Jing (1610.00886 [gr-qc]), and more recently by Ong (1610.05757 [gr-qc]). While these spacetimes are certainly Ricci-flat, and so mathematically satisfy the vacuum Einstein equations, they are also merely minor variants on Taub--NUT spacetimes. Consequently they exhibit several unphysical features that make them quite unreasonable as realistic astrophysical objects. Specifically, these "twisted" black holes are not (globally) asymptotically flat. Furthermore, they contain closed timelike curves that are not hidden behind any event horizon --- the most obvious of these closed timelike curves are small azimuthal circles around the rotation axis, but the effect is more general. The entire region outside the horizon is infested with closed timelike curves.

  17. Van der Waals black hole

    Directory of Open Access Journals (Sweden)

    Aruna Rajagopal

    2014-10-01

    Full Text Available In the context of extended phase space, where the negative cosmological constant is treated as a thermodynamic pressure in the first law of black hole thermodynamics, we find an asymptotically AdS metric whose thermodynamics matches exactly that of the Van der Waals fluid. We show that as a solution of Einstein's equations, the corresponding stress energy tensor obeys (at least for certain range of metric parameters all three weak, strong, and dominant energy conditions.

  18. Opportunity Leaves a Trail of 'Rat' Holes

    Science.gov (United States)

    2004-01-01

    NASA's Mars Exploration Rover Opportunity's rock abrasion tool, known informally as the 'Rat,' has nibbled seven holes into the slope of 'Endurance Crater.' This image from the rover's navigation camera was released previously (PIA06716) without the Rat holes labeled so that viewers could try to find the holes themselves. Here, the holes have been identified. Starting from the uppermost pictured (closest to the crater rim) to the lowest, the Rat hole targets are: 'Tennessee,' 'Cobblehill,' 'Virginia,' 'London,' 'Grindstone,' 'Kettlestone,' and 'Drammensfjorden.' These holes were drilled on sols 138 (June 13, 2004), 143 (June 18), 145 (June 20), 148 (June 23), 151 (June 26), 153 (June 28) and 161 (July 7), respectively. Each hole is 4.5 centimeters (1.8 inches) in diameter.

  19. Collision of two rotating Hayward black holes

    Energy Technology Data Exchange (ETDEWEB)

    Gwak, Bogeun [Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of)

    2017-07-15

    We investigate the spin interaction and the gravitational radiation thermally allowed in a head-on collision of two rotating Hayward black holes. The Hayward black hole is a regular black hole in a modified Einstein equation, and hence it can be an appropriate model to describe the extent to which the regularity effect in the near-horizon region affects the interaction and the radiation. If one black hole is assumed to be considerably smaller than the other, the potential of the spin interaction can be analytically obtained and is dependent on the alignment of angular momenta of the black holes. For the collision of massive black holes, the gravitational radiation is numerically obtained as the upper bound by using the laws of thermodynamics. The effect of the Hayward black hole tends to increase the radiation energy, but we can limit the effect by comparing the radiation energy with the gravitational waves GW150914 and GW151226. (orig.)

  20. Plasma electron-hole kinematics: momentum conservation

    CERN Document Server

    Hutchinson, I H

    2016-01-01

    We analyse the kinematic properties of a plasma electron hole: a non-linear self-sustained localized positive electric potential perturbation, trapping electrons, that behaves as a coherent entity. When a hole accelerates or grows in depth, ion and electron plasma momentum is changed both within the hole and outside it, by an energization process we call jetting. We present a comprehensive analytic calculation of the momentum changes of an isolated general one-dimensional hole. The conservation of the total momentum gives the hole's kinematics, determining its velocity evolution. Our results explain many features of the behavior of hole speed observed in numerical simulations, including self-acceleration at formation, and hole pushing and trapping by ion streams.

  1. Reed's Conjecture on hole expansions

    CERN Document Server

    Fouquet, Jean-Luc

    2012-01-01

    In 1998, Reed conjectured that for any graph $G$, $\\chi(G) \\leq \\lceil \\frac{\\omega(G) + \\Delta(G)+1}{2}\\rceil$, where $\\chi(G)$, $\\omega(G)$, and $\\Delta(G)$ respectively denote the chromatic number, the clique number and the maximum degree of $G$. In this paper, we study this conjecture for some {\\em expansions} of graphs, that is graphs obtained with the well known operation {\\em composition} of graphs. We prove that Reed's Conjecture holds for expansions of bipartite graphs, for expansions of odd holes where the minimum chromatic number of the components is even, when some component of the expansion has chromatic number 1 or when a component induces a bipartite graph. Moreover, Reed's Conjecture holds if all components have the same chromatic number, if the components have chromatic number at most 4 and when the odd hole has length 5. Finally, when $G$ is an odd hole expansion, we prove $\\chi(G)\\leq\\lceil\\frac{\\omega(G)+\\Delta(G)+1}{2}\\rceil+1$.

  2. Soft Hair on Black Holes.

    Science.gov (United States)

    Hawking, Stephen W; Perry, Malcolm J; Strominger, Andrew

    2016-06-10

    It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

  3. Entanglement Entropy of Black Holes

    Directory of Open Access Journals (Sweden)

    Sergey N. Solodukhin

    2011-10-01

    Full Text Available The entanglement entropy is a fundamental quantity, which characterizes the correlations between sub-systems in a larger quantum-mechanical system. For two sub-systems separated by a surface the entanglement entropy is proportional to the area of the surface and depends on the UV cutoff, which regulates the short-distance correlations. The geometrical nature of entanglement-entropy calculation is particularly intriguing when applied to black holes when the entangling surface is the black-hole horizon. I review a variety of aspects of this calculation: the useful mathematical tools such as the geometry of spaces with conical singularities and the heat kernel method, the UV divergences in the entropy and their renormalization, the logarithmic terms in the entanglement entropy in four and six dimensions and their relation to the conformal anomalies. The focus in the review is on the systematic use of the conical singularity method. The relations to other known approaches such as ’t Hooft’s brick-wall model and the Euclidean path integral in the optical metric are discussed in detail. The puzzling behavior of the entanglement entropy due to fields, which non-minimally couple to gravity, is emphasized. The holographic description of the entanglement entropy of the black-hole horizon is illustrated on the two- and four-dimensional examples. Finally, I examine the possibility to interpret the Bekenstein-Hawking entropy entirely as the entanglement entropy.

  4. SEAKEYS - Sand Key 2009 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  5. SEAKEYS - Sand Key 1996 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  6. SEAKEYS - Fowey Rocks 2002 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  7. SEAKEYS - Sombrero Key 2009 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  8. SEAKEYS - Long Key 1992 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  9. SEAKEYS - Sombrero Key 2008 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  10. SEAKEYS DATA - Fowey Rocks 1996 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  11. SEAKEYS DATA-Fowey Rocks 1993 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  12. SEAKEYS - Sand Key 2000 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  13. SEAKEYS - Molasses Reef 2002 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  14. SEAKEYS - Fowey Rocks 1994 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  15. SEAKEYS - Fowey Rocks 1997 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  16. SEAKEYS - Dry Tortugas 1997 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  17. SEAKEYS - Fowey Rocks 2001 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  18. SEAKEYS - Dry Tortugas 1992 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  19. SEAKEYS - Dry Tortugas 1994 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  20. SEAKEYS - Dry Tortugas 2001 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  1. SEAKEYS - Dry Tortugas 1998 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  2. SEAKEYS - Dry Tortugas 1993 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  3. SEAKEYS - Dry Tortugas 2000 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  4. SEAKEYS - Dry Tortugas 1996 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  5. SEAKEYS - Dry Tortugas 1995 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  6. SEAKEYS - Dry Tortugas 2002 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  7. SEAKEYS-Dry Tortugas 1999 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  8. SEAKEYS - Sombrero Key 2001 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  9. SEAKEYS - Molasses Reef 2008 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  10. SEAKEYS -Molasses Reef 2010 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  11. SEAKEYS - Sombrero Key 2000 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  12. SEAKEYS - Sand Key 1998 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  13. SEAKEYS - Sand Key 1994 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  14. SEAKEYS - Sand Key 2008 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  15. SEAKEYS - Sand Key 1992 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  16. SEAKEYS - Sand Key 2001 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  17. SEAKEYS - Sand Key 2002 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  18. SEAKEYS - Sand Key 1993 Meteorological and Oceanographic Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida Institute of Oceanography's (FIO) SEAKEYS (Sustained Ecological Research Related to Management of the Florida Keys Seascape) program began in 1989 and...

  19. Early Student Support for Process Studies of Surface Freshwater Dispersal

    Science.gov (United States)

    2016-06-24

    region to the north, and intrusions of saline w::tter are seen subsurface in the southern part of the section. (c) Black : Amount of heat contained ... Hole Oceanographic Institution REPORT NUMBER Department of Physical Oceanography - MS #29 FINAL Woods Hole , MA 02543 9. SPONSORING/MONITORING AGENCY...ONRREPORT Early Student Support Process Studies of Surface Freshwater Dispersal June 24, 2016 Amala Mahadevan Woods Hole Oceanographic Institution

  20. Residual triamcinolone acetonide sequestered in the fovea after macular hole repair.

    Science.gov (United States)

    Payne, John F; Bergstrom, Chris; Yan, Jiong; Aaberg, Thomas M; Srivastava, Sunil K

    2011-01-01

    To report the macular hole closure rate and visual outcomes of patients with residual triamcinolone acetonide in the fovea after macular hole repair. We reviewed the medical records of consecutive patients who underwent macular hole surgery at our institution between 2005 and 2008. Only patients with visible triamcinolone in the fovea in the first postoperative month were included. Six patients with Stage III or IV macular holes were included. All patients underwent pars plana vitrectomy, internal limiting membrane peeling, and gas tamponade. Triamcinolone acetonide was used to visualize the vitreous in every patient, and diluted indocyanine green was used to stain the internal limiting membrane in five patients. The median preoperative best-corrected visual acuity was 20/200, which improved to a median of 20/40 at the last follow-up. Five patients eventually developed retinal pigment epithelial alterations. Anatomic hole closure was achieved in every patient. The mean follow-up was 23 months (range, 3-36 months). Residual triamcinolone sequestered in the fovea after macular hole surgery did not affect hole closure or prevent improvement in visual acuity. It is unclear whether the retinal pigment epithelial alterations in our patients represent toxicity or are unrelated to the triamcinolone exposure.

  1. Plasma electron hole kinematics. II. Hole tracking Particle-In-Cell simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C.; Hutchinson, I. H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2016-08-15

    The kinematics of a 1-D electron hole is studied using a novel Particle-In-Cell simulation code. A hole tracking technique enables us to follow the trajectory of a fast-moving solitary hole and study quantitatively hole acceleration and coupling to ions. We observe a transient at the initial stage of hole formation when the hole accelerates to several times the cold-ion sound speed. Artificially imposing slow ion speed changes on a fully formed hole causes its velocity to change even when the ion stream speed in the hole frame greatly exceeds the ion thermal speed, so there are no reflected ions. The behavior that we observe in numerical simulations agrees very well with our analytic theory of hole momentum conservation and the effects of “jetting.”.

  2. XFEM Modelling of Multi-holes Plate with Single-row and Staggered Holes Configurations

    Directory of Open Access Journals (Sweden)

    Supar Khairi

    2017-01-01

    Full Text Available Joint efficiency is the key to composite structures assembly design, good structures response is dependent upon multi-holes behavior as subjected to remote loading. Current benchmarking work were following experimental testing series taken from literature on multi-holes problem. Eleven multi-hole configurations were investigated with various pitch and gage distance of staggered holes and non-staggered holes (single-row holes. Various failure modes were exhibited, most staggered holes demonstrates staggered crack path but non-staggered holes series displayed crack path along net-section plane. Stress distribution were carried out and good agreement were exhibited in experimental observation as reported in the respective literature. Consequently, strength prediction work were carried out under quasi-static loading, most showed discrepancy between 8% -31%, better prediction were exhibited in thicker and non-staggered holes plate combinations.

  3. Profiles of temperature, salinity, and other measurements from CTD, XBT, and bottle samplers received from the Japan Oceanographic Data Center (NODC Accession 0054093)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Profiles of temperature, salinity, and other measurements received from the Japan Oceanographic Data Center, Hydrographic and Oceanographic Department as a...

  4. Integrated Coral Observing Network (ICON) - Angel's Reef (Trinidad and Tobago) 2013 Meteorological and Oceanographic Observations from 2013-11-28 to 2013-12-31 (NODC Accession 0123995)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  5. Oceanographic station data from bottle casts from the T-3 in the Arctic Ocean from 29 May 1958 to 17 June 1958 (NODC Accession 7601275)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the T-3 in the Arctic Ocean. Data were collected by the Fisheries Research Board of Canada; Atlantic Oceanographic...

  6. Integrated Coral Observing Network (ICON) - Buccoo Reef (Trinidad and Tobago) 2013 Meteorological and Oceanographic Observations from 2013-11-27 to 2013-12-31 (NODC Accession 0123996)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  7. Integrated Coral Observing Network (ICON) - Media Luna (LPPR1 - La Parguera Natural Reserve, Puerto Rico) 2006 Meteorological and Oceanographic Observations (NODC Accession 0049876)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  8. Integrated Coral Observing Network (ICON) - Media Luna (LPPR1 - La Parguera Natural Reserve, Puerto Rico) 2007 Meteorological and Oceanographic Observations (NODC Accession 0049877)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  9. Integrated Coral Observing Network (ICON) - Salt River Bay (SRVI2 - St. Croix, USVI) Meteorological and Oceanographic Observations from 01 Jan to 31 Dec 2012 (NODC Accession 0117726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  10. Integrated Coral Observing Network (ICON) - Port Everglades (PVGF1 - Port Everglades, Florida) Meteorological and Oceanographic Observations from 01 Jan to 31 Dec 2012 (NODC Accession 0117727)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  11. Integrated Coral Observing Network (ICON) - Little Cayman (Cayman Islands) 2013 Meteorological and Oceanographic Observations from 2013-10-23 to 2013-12-31 (NODC Accession 0123997)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  12. Integrated Coral Observing Network (ICON) - Media Luna (LPPR1 - La Parguera Natural Reserve, Puerto Rico) 2011 Meteorological and Oceanographic Observations (NODC Accession 0098078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  13. Integrated Coral Observing Network (ICON) - Little Cayman, Cayman Islands 2011 Meteorological and Oceanographic observations from January to December, 2011 (NODC Accession 0098079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  14. Integrated Coral Observing Network (ICON) - Media Luna (LPPR1 - La Parguera Natural Reserve, Puerto Rico) 2008 Meteorological and Oceanographic Observations (NODC Accession 0039700)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  15. Integrated Coral Observing Network (ICON) - Norman's Patch Reef (near Lee Stocking Island, Bahamas) 2003 Meteorological and Oceanographic Observations (NODC Accession 0049873)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  16. Integrated Coral Observing Network (ICON) - Little Cayman (LCIY2 - Little Cayman, Cayman Islands) 2012 Meteorological and Oceanographic Observations from 01 Jan to 26 Oct 2012 (NODC Accession 0117730)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlantic Oceanographic and Meteorological Laboratory (AOML) of OAR is conducting research on the influence of meteorological and oceanographic factors upon coral...

  17. Oceanographic station data from bottle casts from the ST CATHARINES from 23 January 1965 to 10 March 1965 (NODC Accession 7601100)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the ST CATHARINES. Data were collected by the Fisheries Research Board of Canada; Pacific Oceanographic Group from 16...

  18. Underway sea surface temperature and salinity data from thermosalinographs collected from multiple platforms assembled by NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains sea surface oceanographic data in netCDF and ASCII formatted files assembled by the NOAA Atlantic Oceanographic and Meteorological...

  19. Surface oceanographic fronts influencing deep-sea biological activity: Using fish stable isotopes as ecological tracers

    Science.gov (United States)

    Louzao, Maite; Navarro, Joan; Delgado-Huertas, Antonio; de Sola, Luis Gil; Forero, Manuela G.

    2017-06-01

    Ecotones can be described as transition zones between neighbouring ecological systems that can be shaped by environmental gradients over a range of space and time scales. In the marine environment, the detection of ecotones is complex given the highly dynamic nature of marine systems and the paucity of empirical data over ocean-basin scales. One approach to overcome these limitations is to use stable isotopes from animal tissues since they can track spatial oceanographic variability across marine systems and, in turn, can be used as ecological tracers. Here, we analysed stable isotopes of deep-sea fishes to assess the presence of ecological discontinuities across the western Mediterranean. We were specifically interested in exploring the connection between deep-sea biological activity and particular oceanographic features (i.e., surface fronts) occurring in the pelagic domain. We collected samples for three different abundant deep-sea species in May 2004 from an experimental oceanographic trawling cruise (MEDITS): the Mictophydae jewel lanternfish Lampanyctus crocodilus and two species of the Gadidae family, the silvery pout Gadiculus argenteus and the blue whiting Micromesistius poutassou. The experimental survey occurred along the Iberian continental shelf and the upper and middle slopes, from the Strait of Gibraltar in the SW to the Cape Creus in the NE. The three deep-sea species were highly abundant throughout the study area and they showed geographic variation in their isotopic values, with decreasing values from north to south disrupted by an important change point around the Vera Gulf. Isotopic latitudinal gradients were explained by pelagic oceanographic conditions along the study area and confirm the existence of an ecotone at the Vera Gulf. This area could be considered as an oceanographic boundary where waters of Atlantic origin meet Mediterranean surface waters forming important frontal structures such as the Almeria-Oran front. In fact, our results

  20. Multichannel seismic/oceanographic/biological monitoring of the oceans

    Science.gov (United States)

    Hello, Y.; Leymarie, E.; Ogé, A.; Poteau, A.; Argentino, J.; Sukhovich, A.; Claustre, H.; Nolet, G.

    2011-12-01

    Delays in seismic P wave are used to make scans or 3D images of the variations in seismic wave speed in the Earth's interior using the techniques of seismic tomography. Observations of such delays are ubiquitous on the continents but rare in oceanic regions. Free-drifting profiling floats that measure the temperature, salinity and current of the upper 2000 m of the ocean are used by physical oceanographers for continuous monitoring in the Argo program. Recently, seismologists developed the idea to use such floats in order to compensate for the lack of seismic delay observations, especially in the southern hemisphere. In project Globalseis, financed by a grant from the European Research Council (ERC), we have developed and tested a prototype of such a seismological sensor using an Apex float from Teledyne Webb Research, a Rafos hydrophone, and electronics developed in collaboration with Osean, a small engineering firm in France. `MERMAID', for `Mobile Earthquake Recorder in Marine Areas by Independent Divers' is approaching its final design and should become available off the shelf in 2012. In the meantime we initiated a collaboration between Globalseis and another ERC project, remOcean, for the acquisition of radiometric, bio-geochemical data and meteorological observations in addition to salinity and temperature (Bio-Argo program). In this collaboration of Geoazur and LOV (Laboratoire d'Océanologie de Villefranche sur mer), two laboratories located at the Observatory of Villefranche, we developed a multichannel acquisition hardware electronics called 'PAYLOAD' that allows commercial floats such as Apex (TWR) and Provor (NKE) to serve multiple observing missions simultaneously. Based on an algorithm using wavelet transforms PAYLOAD continuously analyzes acoustic signals to detect major seismic events and weather phenomena such rain, drizzle, open sea and ice during drift diving phase. The bio-geochemical and other parameters are recorded and analyzed during ascent

  1. Holocene climate variability and oceanographic changes off western South Africa

    Science.gov (United States)

    Zhao, Xueqin; Dupont, Lydie; E Meadows, Michael; Schefuß, Enno; Bouimetarhan, Ilham; Wefer, Gerold

    2017-04-01

    South Africa is located at a critical transition zone between subtropical and warm-temperate climate zones influenced by the Indian and Atlantic oceans. Presently, the seasonal changes of atmospheric and oceanic systems induce a pronounced rainfall seasonality comprised of two different rainfall zones over South Africa. How did this seasonality develop during the Holocene? To obtain a better understanding of how South African climates have evolved during the Holocene, we conduct a comprehensive spatial-temporal approach including pollen and dinoflagellate cyst records from marine sediment samples retrieved from the Namaqualand mudbelt, a Holocene terrigenous mud deposit on the shelf of western South Africa. The representation of different vegetation communities in western South Africa is assessed through pollen analysis of surface sediments. This approach allows for climate reconstructions of the summer rainfall zone (SRZ) using Group 1 (Poaceae, Cyperaceae, Phragmites-type and Typha) and winter rainfall zone (WRZ) using Group 2 (Restionaceae, Ericaceae, Anthospermum, Stoebe/Elytropappus-type, Cliffortia, Passerina, Artemisia-type and Pentzia-type) from a single marine archive. The fossil pollen data from gravity core GeoB8331-4 indicate contrasting climate patterns in the SRZ and WRZ especially during the early and middle Holocene. The rainfall amount in the SRZ is dominated by insolation forcing, while in the WRZ it is mainly attributed to the latitudinal position of the southern westerlies. Dinoflagellate cyst data show significantly different oceanographic conditions associated with climate changes on land. High percentages of autotrophic taxa like Operculodinium centrocarpum and Spiniferites spp. indicate warm and stratified conditions during the early Holocene, suggesting reduced upwelling. In contrast, the middle Holocene is characterized by a strong increase in heterotrophic taxa in particular Lejeunecysta paratenella and Echinidinium spp., indicating cool

  2. Oceanographic data at your fingertips: the SOCIB App for smartphones

    Science.gov (United States)

    Lora, Sebastian; Sebastian, Kristian; Troupin, Charles; Pau Beltran, Joan; Frontera, Biel; Gómara, Sonia; Tintoré, Joaquín

    2015-04-01

    The Balearic Islands Coastal Ocean Observing and Forecasting System (SOCIB, http://www.socib.es), is a multi-platform Marine Research Infrastructure that generates data from nearshore to the open sea in the Western Mediterranean Sea. In line with SOCIB principles of discoverable, freely available and standardized data, an application (App) for smartphones has been designed, with the objective of providing an easy access to all the data managed by SOCIB in real-time: underwater gliders, drifters, profiling buoys, research vessel, HF Radar and numerical model outputs (hydrodynamics and waves). The Data Centre, responsible for the aquisition, processing and visualisation of all SOCIB data, developed a REpresentational State Transfer (REST) application programming interface (API) called "DataDiscovery" (http://apps.socib.es/DataDiscovery/). This API is made up of RESTful web services that provide information on : platforms, instruments, deployments of instruments. It also provides the data themselves. In this way, it is possible to integrate SOCIB data in third-party applications, developed either by the Data Center or externally. The existence of a single point for the data distribution not only allows for an efficient management but also makes easier the concepts and data access for external developers, who are not necessarily familiar with the concepts and tools related to oceanographic or atmospheric data. The SOCIB App for Android (https://play.google.com/store/apps/details?id=com.socib) uses that API as a "data backend", in such a way that it is straightforward to manage which information is shown by the application, without having to modify and upload it again. The only pieces of information that do not depend on the services are the App "Sections" and "Screens", but the content displayed in each of them is obtained through requests to the web services. The API is not used only for the smartphone app: presently, most of SOCIB applications for data visualisation

  3. International Polar Year 2007: An Integrated Heliospheric and Oceanographic Program?

    Science.gov (United States)

    Johnson, G.; Davila, J.

    An international symposium SPerspectives of Modern Polar ResearchT was convened - in Bad Durkeim, Germany 2001 to celebrated the 175the anniversary of the birth of Georg von Neumayer. At that symposium the Nermayer Declaration was adopted to commemorate the 125th anniversary of the IPY in 2007. SA 125th year IPY program be initiated using new and present technologies to determine: 1 . Causes and effects of climatic variability-air/sea/ice interactins, and 2. Lithosphere dynamicsUevolution and history of crust and sedimentary cover. The po lar regions would be the focus.T Polar oceanographic contributions to global climate change are still a matter of conjecture, and to a large extent so are the extraterrestrial contributions. The proposed IPY would focus on these issues. As part of the global heat engine, the polar regions hav a major role in the worldSs transfer of energy, and the ocean/stmosphere system is known to be both an indicator and a componenet of climate change. It is clear that acomplex suite of significant, interrelated, atmospheric, oceanic and terrestrial changes has occurred in the the polsar regions in recent decades. These events are affecting every part of the polar environment and are having repercussions on society. In a similar vein an International Heliophysical Year (IHY) has been proposed to obtain a coordinated set of observations to study at the largest scale the solar genergated events that affect life and climate on Earth as has been documented in the Holocene sedimentary recofd. A modeling capability is the ultimate goal so the physical process can be tracked throughout the entire Sun-Earth system. This program will require an integrated, holistic system approach encompassing a side range of disciplines with new and improved technologies for long term measurements on the seabed, in the water column and in space over all seasons. Coordination, collaboration and documentation of an interated science plan with international scientific

  4. Available climatological and oceanographical data for site investigation program

    Energy Technology Data Exchange (ETDEWEB)

    Lindell, S.; Ambjoern, C.; Juhlin, B.; Larsson-McCann, S.; Lindquist, K. [Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden)

    2000-03-15

    Information on available data, measurements and models for climate, meteorology, hydrology and oceanography for six communities have been analysed and studied. The six communities are Nykoeping, Oesthammar, Oskarshamn, Tierp, Hultsfred and Aelvkarleby all of them selected by Svensk Kaernbraenslehantering AB, SKB, for a pre-study on possibilities for deep disposal of used nuclear fuel. For each of them a thorough and detailed register of available climatological data together with appropriate statistical properties are listed. The purpose is to compare the six communities concerning climatological and oceanographical data available and analyse the extent of new measurements or model applications needed for all of the selected sites. Statistical information on precipitation, temperature and runoff has good coverage in all of the six communities. If new information concerning any of these variables is needed in sites where no data collection exist today new installation can be made. Data on precipitation in form of snow and days with snow coverage is also available but to a lesser extent. This concerns also days with ground frost and average ground frost level where there is no fully representation of data. If more information is wanted concerning these variables new measurements or model calculations must be initiated. Data on freeze and break-up of ice on lakes is also insufficient but this variable can be calculated with good result by use of one-dimensional models. Data describing air pressure tendency and wind velocity and direction is available for all communities and this information should be sufficient for the purpose of SKB. This is also valid for the variables global radiation and duration of sunshine where no new data should be needed. Measured data on evaporation is normally not available in Sweden more than in special research basins. Actual evaporation is though a variable that easily can be calculated by use of models. There are many lakes in the six

  5. Institutional ethnography

    DEFF Research Database (Denmark)

    Lund, Rebecca; Tienari, Janne

    2016-01-01

    The study of M&As is dominated by positivist and functionalist world views and the use of quantitative methods. Although extant research also uses qualitative and mixed methods, it can be criticized for viewing its subject matter through an abstract and external lens. The researcher is placed in ......, and point to some of the problems in M&A studies identified through this lens. Finally, we argue why institutional ethnography, in comparison with other methods of inquiry, is particularly fruitful in the study of mergers and acquisitions....

  6. User requirements for NASA data base management systems. Part 1: Oceanographic discipline

    Science.gov (United States)

    Fujimoto, B.

    1981-01-01

    Generic oceanographic user requirements were collected and analyzed for use in developing a general multipurpose data base management system for future missions of the Office of Space and Terrestrial Applications (OSTA) of NASA. The collection of user requirements involved; studying the state-of-the-art technology in data base management systems; analyzing the results of related studies; formulating a viable and diverse list of scientists to be interviewed; developing a presentation format and materials; and interviewing oceanographic data users. More effective data management systems are needed to handle the increasing influx of data.

  7. Limits on P: filling in holes vs. falling in holes

    Directory of Open Access Journals (Sweden)

    Peter Svenonius

    2004-01-01

    Full Text Available All Germanic languages make extensive use of verb-particle combinations (known as separable-prefix verbs in the OV languages. I show some basic differences here distinguishing the Scandinavian type from the OV West Germanic languages, with English superficially patterning with Scandinavian but actually manifesting a distinct type. Specifically, I argue that the P projection is split into p and P (in accordance with earlier work, roughly analogous to v and V in the verb phrase. In English, p is always present in PP, and enables P to assign case, if P has an internal argument (as it does in "fall in the hole". The arguments of particle verbs are then arguments of p, external arguments of the particle (as in "throw the rock in". OV West Germanic allows p to be missing completely, thus having a type of unaccusative particle whose inner argument must receive case from the verb (corresponding to "fall the hole in," impossible in English. Scandinavian allows p to be missing, so that there is no external argument of the particle, but provides an alternative source for case for the internal argument (giving examples corresponding to "pour in the glass". Thus English and Scandinavian are different from OV West Germanic in lacking the unaccusative type of particle, while Scandinavian differs from OV West Germanic and English in having an alternative source of case.

  8. Positioning In Macular hole Surgery (PIMS): statistical analysis plan for a randomised controlled trial.

    Science.gov (United States)

    Bell, Lauren; Hooper, Richard; Bunce, Catey; Pasu, Saruban; Bainbridge, James

    2017-06-13

    using Snellen charts at a standard distance of 6 m; patient-reported health and quality of life assessed using the National Eye Institute Visual Function Questionnaire (VFQ-25). The PIMS trial is the first multicentre randomised control trial to investigate the value of face-down positioning following macular hole standardised surgery. International Standard Randomised Controlled Trials Number registry, ID: ISRCTN12410596. Registered on 11 February 2015. United Kingdom Clinical Research Network, ID: UKCRN17966 . Registered on 26 November 2014.

  9. Boosting jet power in black hole spacetimes

    Science.gov (United States)

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W.; Liebling, Steven L.; Motl, Patrick M.; Garrett, Travis

    2011-01-01

    The extraction of rotational energy from a spinning black hole via the Blandford–Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux. PMID:21768341

  10. Boosting jet power in black hole spacetimes.

    Science.gov (United States)

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W; Liebling, Steven L; Motl, Patrick M; Garrett, Travis

    2011-08-02

    The extraction of rotational energy from a spinning black hole via the Blandford-Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux.

  11. Monitoring Holes in the Sun's Corona

    Science.gov (United States)

    Kohler, Susanna

    2016-09-01

    Coronal holes are where the fast solar wind streams out of the Suns atmosphere, sending charged particles on rapid trajectories out into the solar system. A new study examines how the distribution of coronal holes has changed over the last 40 years.Coronal holes form where magnetic field lines open into space (B) instead of looping back to the solar surface (A). [Sebman81]Source of the Fast Solar WindAs a part of the Suns natural activity cycle, extremely low-density regions sometimes form in the solar corona. These coronal holes manifest themselves as dark patches in X-ray and extreme ultraviolet imaging, since the corona is much hotter than the solar surface that peeks through from underneath it.Coronal holes form when magnetic field lines open into space instead of looping back to the solar surface. In these regions, the solar atmosphere escapes via these field lines, rapidly streaming away from the Suns surface in whats known as the fast solar wind.Coronal Holes Over Space and TimeAutomated detection of coronal holes from image-based analysis is notoriously difficult. Recently, a team of scientists led by Kenichi Fujiki (ISEE, Nagoya University, Japan) has developed an automated prediction technique for coronal holes that relies instead on magnetic-field data for the Sun, obtained at the National Solar Observatorys Kitt Peak between 1975 and 2014. The team used these data to produce a database of 3335 coronal hole predictions over nearly 40 years.Latitude distribution of 2870 coronal holes (each marked by an x; color indicates polarity), overlaid on the magnetic butterfly map of the Sun. The low-latitude coronal holes display a similar butterfly pattern, in which they move closer to the equator over the course of the solar cycle. Polar coronal holes are more frequent during solar minima. [Fujiki et al. 2016]Examining trends in the coronal holes distribution in latitude and time, Fujiki and collaborators find a strong correlation between the total area covered

  12. The Recovery of the Antarctic Ozone Hole

    Science.gov (United States)

    Newman, Paul A.

    2004-01-01

    The ozone hole is a massive loss of ozone that annually occurs over Antarctica during the Austral spring (August-November). Man-made chlorine and bromine compounds cause the ozone hole. As opposed to local urban pollution, the hole illustrates how man-made chemicals can affect the atmosphere over enormous regions remote from their release point. These chlorine and bromine gases have long lifetimes in the atmosphere; hence, the ozone hole will slowly recover into the next few decades. In this talk I will briefly cover some of the history of the Antarctic ozone hole and the theory behind the phenomena. I will then discuss the recovery of ozone over Antarctica. State-of-the-art computer models project the recovery of the ozone hole to 1980 levels by about 2050. However, this recovery may be affected by greenhouse warming.

  13. Information Retention by Stringy Black Holes

    CERN Document Server

    Ellis, John

    2015-01-01

    Building upon our previous work on two-dimensional stringy black holes and its extension to spherically-symmetric four-dimensional stringy black holes, we show how the latter retain information. A key r\\^ole is played by an infinite-dimensional $W_\\infty$ symmetry that preserves the area of an isolated black-hole horizon and hence its entropy. The exactly-marginal conformal world-sheet operator representing a massless stringy particle interacting with the black hole necessarily includes a contribution from $W_\\infty$ generators in its vertex function. This admixture manifests the transfer of information between the string black hole and external particles. We discuss different manifestations of $W_\\infty$ symmetry in black-hole physics and the connections between them.

  14. What does a black hole look like?

    CERN Document Server

    Bailyn, Charles D

    2014-01-01

    Emitting no radiation or any other kind of information, black holes mark the edge of the universe--both physically and in our scientific understanding. Yet astronomers have found clear evidence for the existence of black holes, employing the same tools and techniques used to explore other celestial objects. In this sophisticated introduction, leading astronomer Charles Bailyn goes behind the theory and physics of black holes to describe how astronomers are observing these enigmatic objects and developing a remarkably detailed picture of what they look like and how they interact with their surroundings. Accessible to undergraduates and others with some knowledge of introductory college-level physics, this book presents the techniques used to identify and measure the mass and spin of celestial black holes. These key measurements demonstrate the existence of two kinds of black holes, those with masses a few times that of a typical star, and those with masses comparable to whole galaxies--supermassive black holes...

  15. Braneworld black holes and entropy bounds

    Directory of Open Access Journals (Sweden)

    Y. Heydarzade

    2018-01-01

    Full Text Available The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.

  16. Braneworld black holes and entropy bounds

    Science.gov (United States)

    Heydarzade, Y.; Hadi, H.; Corda, C.; Darabi, F.

    2018-01-01

    The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.

  17. Hole spin relaxation in quantum dots

    Science.gov (United States)

    Woods, L. M.; Reinecke, T. L.; Kotlyar, R.

    2004-03-01

    We present results for relaxation of the spin of a hole in a cylindrical quantum dot due to acoustic phonon assisted spin flips at low temperatures with an applied magnetic field. The hole dispersion is calculated by numerical diagonalization of the Luttinger Hamiltonian and applying perturbation theory with respect to the magnetic field, and the hole-phonon coupling is described by the Bir-Pikus Hamiltonian. We find that the decoherence time for hole spins for dots ≲20 nm is on the order of 10-8 s. This is several orders smaller than the decoherence time due to phonon assisted processes for electron spins in similar dots and is comparable to the total decoherence time of an electron spin in a quantum dot, which is controlled by the hyperfine interaction with nuclei. We obtain the dependence of the relaxation rate of the hole spin on dot size and hole mass.

  18. BSW process of the slowly evaporating charged black hole

    OpenAIRE

    Wang, Liancheng; He, Feng; Fu, Xiangyun

    2015-01-01

    In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.

  19. Institute news

    Science.gov (United States)

    1999-11-01

    Joining the team A new member of staff has recently joined the Institute of Physics Education Department (Schools and Colleges) team. (Dr) Steven Chapman will have managerial responsibility for physics education issues in the 11 - 16 age range, particularly on the policy side. He will work closely with Mary Wood, who spends much of her time out and about doing the practical things to support physics education pre-16. Catherine Wilson will be spending more of her time working to support the Post-16 Physics Initiative but retains overall responsibility for the department. Steven graduated in Physics and Astronomy and then went on to do his doctorate at Sussex University. He stayed in the research field for a while, including a period at NPL. Then, having decided to train as a teacher, he taught for the last five years, most recently at a brand new school in Sutton where he was Head of Physics. Physics update Dates for `Physics Update' courses in 2000, intended for practising science teachers, are as follows: 1 - 3 April: Malvern College 9 - 10 June: Stirling University 8 - 10 July: York University 8 - 10 December: Oxford University The deadline for applications for the course to be held on 11 - 13 December 1999 at the School of Physics, Exeter University, is 12 November, so any late enquiries should be sent to Leila Solomon at The Institute of Physics, 76 Portland Place, London W1N 3DH (tel: 020 7470 4821) right away. Name that teacher! Late nominations are still welcome for the Teachers of Physics/Teachers of Primary Science awards for the year 2000. Closing date for nominations is `the last week in November'. Further details can be obtained from Catherine Wilson or Barbara Hill in the Institute's Education Department. Forward and back! The Education Group's one-day meeting on 13 November is accepting bookings until almost the last minute, so don't delay your application! The day is entitled `Post-16 physics: Looking forward, learning from the past' and it aims to

  20. Oblique magnetic fields and the role of frame dragging near a rotating black hole

    Czech Academy of Sciences Publication Activity Database

    Karas, Vladimír; Kopáček, Ondřej; Kunneriath, Devaky; Hamerský, Jaroslav

    2014-01-01

    Roč. 54, č. 6 (2014), s. 398-413 ISSN 1210-2709 R&D Projects: GA ČR GB14-37086G; GA MŠk(CZ) LH14049 Institutional support: RVO:67985815 Keywords : black hole s * accretion discs Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  1. X-ray Measurements of Black Hole X-ray Binary Source GRS 1915+ ...

    Indian Academy of Sciences (India)

    tribpo

    X-ray Measurements of Black Hole X-ray Binary Source GRS. 1915+105 and the Evolution of Hard X-ray Spectrum. R. K. Manchanda, Tata Institute of Fundamental Research, Mumbai 400 005, India,. Received 1999 December 28; accepted 2000 February 9. Abstract. We report the spectral measurement of GRS 1915+105 ...

  2. Black hole spin dependence of general relativistic multi-transonic accretion close to the horizon

    Czech Academy of Sciences Publication Activity Database

    Das, T. K.; Nag, S.; Hedge, S.; Bhattacharya, S.; Maity, I.; Czerny, B.; Barai, P.; Wiita, P. J.; Karas, Vladimír; Naskar, T.

    2015-01-01

    Roč. 37, May (2015), s. 81-104 ISSN 1384-1076 R&D Projects: GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : black hole s * accretion discs Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.085, year: 2015

  3. Investigating the Relativistic Motion of the Stars Near the Supermassive Black Hole in the Galactic Center

    Czech Academy of Sciences Publication Activity Database

    Parsa, M.; Eckart, A.; Shahzamanian, B.; Karas, Vladimír; Zajaček, M.; Zensus, J. A.; Straubmeier, C.

    2017-01-01

    Roč. 845, č. 1 (2017), 22/1-22/19 ISSN 0004-637X EU Projects: European Commission(XE) 312789 - STRONGGRAVITY Institutional support: RVO:67985815 Keywords : :astrometry * black hole physics * galactic center Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.533, year: 2016

  4. Beyond the standard model of the disc-line spectral profiles from black hole accretion discs

    Czech Academy of Sciences Publication Activity Database

    Sochora, Vjačeslav; Karas, Vladimír; Svoboda, Jiří; Dovčiak, Michal

    2014-01-01

    Roč. 54, č. 4 (2014), s. 301-304 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : accretion discs * black hole physics * galactic nuclei Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  5. Magnetic Neutral Points and Electric Lines of Force in Strong Gravity of a Rotating Black Hole

    Czech Academy of Sciences Publication Activity Database

    Karas, Vladimír; Kopáček, Ondřej; Kunneriath, Devaky

    2013-01-01

    Roč. 3, 3A (2013), s. 18-24 ISSN 2161-4717 R&D Projects: GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : galaxies * nuclei * black hole physics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  6. From holes to huts: reconstructing an extinct type of architecture at the Sixth Nile Cataract

    Czech Academy of Sciences Publication Activity Database

    Varadzin, Ladislav; Varadzinová, L.; Pacina, J.

    2017-01-01

    Roč. 91, č. 357 (2017), s. 589-604 ISSN 0003-598X Institutional support: RVO:67985912 Keywords : North Africa * Sudan * Sixth Nile Cataract * Mesolithic * architecture * drilled holes Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 1.536, year: 2016

  7. Superradiance by mini black holes with mirror

    OpenAIRE

    Lee, Jong-Phil

    2011-01-01

    The superradiant scattering of massive scalar particles by a rotating mini black hole is investigated. Imposing the mirror boundary condition, the system becomes the so called black-hole bomb where the rotation energy of the black hole is transferred to the scattered particle exponentially with time. Bulk emissions as well as brane emissions are considered altogether. It is found that the largest effects are expected for the brane emission of lower angular modes with lighter mass and larger a...

  8. Gravitational lensing by a Horndeski black hole

    Science.gov (United States)

    Badía, Javier; Eiroa, Ernesto F.

    2017-11-01

    In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to black holes in General Relativity. We analyze the astrophysical consequences in the case of the nearest supermassive black holes.

  9. Computational Complexity and Black Hole Horizons

    OpenAIRE

    Susskind, Leonard

    2014-01-01

    Computational complexity is essential to understanding the properties of black hole horizons. The problem of Alice creating a firewall behind the horizon of Bob's black hole is a problem of computational complexity. In general we find that while creating firewalls is possible, it is extremely difficult and probably impossible for black holes that form in sudden collapse, and then evaporate. On the other hand if the radiation is bottled up then after an exponentially long period of time firewa...

  10. Cool horizons for entangled black holes

    OpenAIRE

    Maldacena, Juan; Susskind, Leonard

    2013-01-01

    General relativity contains solutions in which two distant black holes are connected through the interior via a wormhole, or Einstein-Rosen bridge. These solutions can be interpreted as maximally entangled states of two black holes that form a complex EPR pair. We suggest that similar bridges might be present for more general entangled states. In the case of entangled black holes one can formulate versions of the AMPS(S) paradoxes and resolve them. This suggests possible resolutions of the fi...

  11. Geometrothermodynamics of Van der Waals black hole

    Science.gov (United States)

    Hu, Yumin; Chen, Juhua; Wang, Yongjiu

    2017-12-01

    We study the geometrothermodynamics of a special asymptotically AdS black hole, i.e. Van der Waals ( VdW) black hole, in the extended phase space where the negative cosmological constant Λ can be regarded as thermodynamic pressure. Analysing some special conditions of this black hole with geometrothermodynamical method, we find a good correlation with ordinary cases according to the state equation.

  12. Techniques for Binary Black Hole Simulations

    Science.gov (United States)

    Baker, John G.

    2006-01-01

    Recent advances in techniques for numerical simulation of black hole systems have enabled dramatic progress in astrophysical applications. Our approach to these simulations, which includes new gauge conditions for moving punctures, AMR, and specific tools for analyzing black hole simulations, has been applied to a variety of black hole configurations, typically resulting in simulations lasting several orbits. I will discuss these techniques, what we've learned in applications, and outline some areas for further development.

  13. A New Model of Black Hole Formation

    Directory of Open Access Journals (Sweden)

    Thayer G. D.

    2013-10-01

    Full Text Available The formation of a black hole and its event horizon are described. Conclusions, which are the result of a thought experiment, show that Schwarzschild [1] was correct: A singularity develops at the event horizon of a newly-formed black hole. The intense gravitational field that forms near the event horizon results in the mass-energy of the black hole accumulating in a layer just inside the event horizon, rather than collapsing into a central singularity.

  14. Black hole evaporation in conformal gravity

    Science.gov (United States)

    Bambi, Cosimo; Modesto, Leonardo; Porey, Shiladitya; Rachwał, Lesław

    2017-09-01

    We study the formation and the evaporation of a spherically symmetric black hole in conformal gravity. From the collapse of a spherically symmetric thin shell of radiation, we find a singularity-free non-rotating black hole. This black hole has the same Hawking temperature as a Schwarzschild black hole with the same mass, and it completely evaporates either in a finite or in an infinite time, depending on the ensemble. We consider the analysis both in the canonical and in the micro-canonical statistical ensembles. Last, we discuss the corresponding Penrose diagram of this physical process.

  15. Rotating black holes in brane worlds

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Valeri P.; Stojkovic, Dejan; Fursaev, Dmitri V. E-mail: fursaev@thsun1.jinr.ru

    2004-06-01

    We study interaction of rotating higher dimensional black holes with a brane in space-times with large extra dimensions. We demonstrate that a rotating black hole attached to a brane can be stationary only if the null Killing vector generating the black hole horizon is tangent to the brane world-sheet. The characteristic time when a rotating black hole with the gravitational radius r{sub 0} reaches this final stationary state is T {approx} r{sub 0}{sup p}'-'1/(G{sigma}), where G is the higher dimensional gravitational coupling constant, {sigma} is the brane tension, and p is the number of extra dimensions. (author)

  16. Rotating black holes in brane worlds

    OpenAIRE

    Frolov, Valeri P.; Fursaev, Dmitri V.; Stojkovic, Dejan

    2004-01-01

    We study interaction of rotating higher dimensional black holes with a brane in space-times with large extra dimensions. We demonstrate that a rotating black hole attached to a brane can be stationary only if the null Killing vector generating the black hole horizon is tangent to the brane world-sheet. The characteristic time when a rotating black hole with the gravitational radius $r_0$ reaches this final stationary state is $T\\sim r_0^{p-1}/(G\\sigma)$, where $G$ is the higher dimensional gr...

  17. Planar domain walls in black hole spacetimes

    Science.gov (United States)

    Ficek, Filip; Mach, Patryk

    2018-02-01

    We investigate the behavior of low-mass, planar domain walls in the so-called ϕ4 model of the scalar field on the Schwarzschild and Kerr backgrounds. We focus on a transit of a domain wall through a black hole and solve numerically the equations of motion for a range of parameters of the domain wall and the black hole. We observe a behavior resembling an occurrence of ringing modes. Perturbations of domain walls vanish during latter evolution, suggesting their stability against a passage through the black hole. The results obtained for Kerr and Reissner-Nordström black holes are also compared.

  18. Rotating black holes and Coriolis effect

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chia-Jui, E-mail: agoodmanjerry.ep02g@nctu.edu.tw [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan, ROC (China); Wu, Xiaoning, E-mail: wuxn@amss.ac.cn [Institute of Mathematics, Academy of Mathematics and System Science, CAS, Beijing, 100190 (China); Yang, Yi, E-mail: yiyang@mail.nctu.edu.tw [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan, ROC (China); Yuan, Pei-Hung, E-mail: phyuan.py00g@nctu.edu.tw [Institute of Physics, National Chiao Tung University, Hsinchu, Taiwan, ROC (China)

    2016-10-10

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the suitable boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  19. Rotating black holes and Coriolis effect

    Directory of Open Access Journals (Sweden)

    Chia-Jui Chou

    2016-10-01

    Full Text Available In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the suitable boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  20. Schwarzschild black holes can wear scalar wigs.

    Science.gov (United States)

    Barranco, Juan; Bernal, Argelia; Degollado, Juan Carlos; Diez-Tejedor, Alberto; Megevand, Miguel; Alcubierre, Miguel; Núñez, Darío; Sarbach, Olivier

    2012-08-24

    We study the evolution of a massive scalar field surrounding a Schwarzschild black hole and find configurations that can survive for arbitrarily long times, provided the black hole or the scalar field mass is small enough. In particular, both ultralight scalar field dark matter around supermassive black holes and axionlike scalar fields around primordial black holes can survive for cosmological times. Moreover, these results are quite generic in the sense that fairly arbitrary initial data evolve, at late times, as a combination of those long-lived configurations.

  1. Particle accelerators inside spinning black holes.

    Science.gov (United States)

    Lake, Kayll

    2010-05-28

    On the basis of the Kerr metric as a model for a spinning black hole accreting test particles from rest at infinity, I show that the center-of-mass energy for a pair of colliding particles is generically divergent at the inner horizon. This shows not only that classical black holes are internally unstable, but also that Planck-scale physics is a characteristic feature within black holes at scales much larger that the Planck length. The novel feature of the divergence discussed here is that the phenomenon is present only for black holes with rotation, and in this sense it is distinct from the well-known Cauchy horizon instability.

  2. Drilling history core hole DC-8

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

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

  3. Low-mass black holes as the remnants of primordial black hole formation.

    Science.gov (United States)

    Greene, Jenny E

    2012-01-01

    Bridging the gap between the approximately ten solar mass 'stellar mass' black holes and the 'supermassive' black holes of millions to billions of solar masses are the elusive 'intermediate-mass' black holes. Their discovery is key to understanding whether supermassive black holes can grow from stellar-mass black holes or whether a more exotic process accelerated their growth soon after the Big Bang. Currently, tentative evidence suggests that the progenitors of supermassive black holes were formed as ∼10(4)-10(5) M(⊙) black holes via the direct collapse of gas. Ongoing searches for intermediate-mass black holes at galaxy centres will help shed light on this formation mechanism.

  4. Superluminality, black holes and EFT

    Science.gov (United States)

    Goon, Garrett; Hinterbichler, Kurt

    2017-02-01

    Under the assumption that a UV theory does not display superluminal behavior, we ask what constraints on superluminality are satisfied in the effective field theory (EFT). We study two examples of effective theories: quantum electrodynamics (QED) coupled to gravity after the electron is integrated out, and the flat-space galileon. The first is realized in nature, the second is more speculative, but they both exhibit apparent superluminality around non-trivial backgrounds. In the QED case, we attempt, and fail, to find backgrounds for which the superluminal signal advance can be made larger than the putative resolving power of the EFT. In contrast, in the galileon case it is easy to find such backgrounds, indicating that if the UV completion of the galileon is (sub)luminal, quantum corrections must become important at distance scales of order the Vainshtein radius of the background configuration, much larger than the naive EFT strong coupling distance scale. Such corrections would be reminiscent of the non-perturbative Schwarzschild scale quantum effects that are expected to resolve the black hole information problem. Finally, a byproduct of our analysis is a calculation of how perturbative quantum effects alter charged Reissner-Nordstrom black holes.

  5. The Black Hole Accretion Code

    CERN Document Server

    Porth, Oliver; Mizuno, Yosuke; Younsi, Ziri; Rezzolla, Luciano; Moscibrodzka, Monika; Falcke, Heino; Kramer, Michael

    2016-01-01

    We present the black hole accretion code (BHAC), a new multidimensional general-relativistic magnetohydrodynamics module for the MPI-AMRVAC framework. BHAC has been designed to solve the equations of ideal general-relativistic magnetohydrodynamics in arbitrary spacetimes and exploits adaptive mesh refinement techniques with an efficient block-based approach. Several spacetimes have already been implemented and tested. We demonstrate the validity of BHAC by means of various one-, two-, and three-dimensional test problems, as well as through a close comparison with the HARM3D code in the case of a torus accreting onto a black hole. The convergence of a turbulent accretion scenario is investigated with several diagnostics and we find accretion rates and horizon-penetrating fluxes to be convergent to within a few percent when the problem is run in three dimensions. Our analysis also involves the study of the corresponding thermal synchrotron emission, which is performed by means of a new general-relativistic radi...

  6. Silent film: The Carlsberg Foundation’s Oceanographic Expedition Round the World, 1928–30

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2016-01-01

    Danish marine scientist, Johannes Schmidt was also a pioneer when it comes to popularizing deep-sea marine research through the use of mass media. When Schmidt headed the Carlsberg Foundation’s Oceanographical Expedition Round the World, 1928-1930, he brought along a film camera, documenting...

  7. A descriptive analysis of temporal and spatial patterns of variability in Puget Sound oceanographic properties

    Science.gov (United States)

    Stephanie Moore; Nathan J. Mantua; Jan A. Newton; Mitsuhiro Kawase; Mark J. Warner; Jonathan P. Kellogg

    2008-01-01

    Temporal and spatial patterns of variability in Puget Sound's oceanographic properties are determined using continuous vertical profile data from two long-term monitoring programs; monthly observations at 16 stations from 1993 to 2002, and biannual observations at 40 stations from 1998 to 2003. Climatological monthly means of temperature, salinity, and density...

  8. Early Student Support for Application of Advanced Multi-Core Processor Technologies to Oceanographic Research

    Science.gov (United States)

    2016-05-07

    Student Support for Appl ication of Advanced Multi-Core Processor N00014-12-1-0298 Technologies to Oceanographic Research Sb. GRANT NUMBER Sc...JavaScript, and C to date) to interface with our data storage and distribution application programming interfaces (APis). The second is a complete

  9. TRIGA OCEANOGRAPHIC POWER SUPPLY FOR A MANNED UNDERWATER STATION. VOLUME I. REFERENCE DESIGN.

    Science.gov (United States)

    The TRIGA Oceanographic Power Supply (TOPS) is designed to provide 100 kw of electrical power for a Manned Underwater Station (MUS). The design is... TRIGA research reactor. It contains the entire pressurized water primary coolant circuit and the steam generator. The U-ZrH-fueled, water-cooled core

  10. A simple low cost speed log interface for oceanographic data acquisition system

    Digital Repository Service at National Institute of Oceanography (India)

    Khedekar, V.D.; Phadte, G.M.

    A speed log interface is designed with parallel Binary Coded Decimal output. This design was mainly required for the oceanographic data acquisition system as an interface between the speed log and the computer. However, this can also be used as a...

  11. Shared Semantics for Oceanographic Research: Development of Standard ``Cruise-Level'' Metadata

    Science.gov (United States)

    Arko, R. A.; Milan, A.; Chandler, C. L.; Miller, S. P.; Ferrini, V.; Mesick, S.; Mize, J.; Paver, C.; Sullivan, B.; Sweeney, A.

    2010-12-01

    There is a general need in the ocean science community for a widely accepted standards-based “cruise-level” metadata profile that describes the basic elements of a seagoing expedition (e.g. cruise identifier, vessel name, operating institution, dates/ports, navigation track, survey targets, science party, funding sources, scientific instruments, daughter platforms, and data sets). The need for such a profile is increasingly urgent as seagoing programs become more complex and interdisciplinary; funding agencies mandate public dissemination of the resulting data; and data centers link post-field/derived products to original field data sets. We are developing a standard implementation for cruise-level metadata that serves the needs of multiple U.S. programs, in an effort to promote interoperability and facilitate collaboration. Testbed development has focused on the Rolling Deck to Repository (R2R) and Extended Continental Shelf (ECS) programs - both tasked with routinely documenting and archiving large volumes of data from a wide array of U.S. research vessels - and draws from the cruise-level metadata profile published by the University-National Oceanographic Laboratory System (UNOLS) Data Management Best Practices Committee in 2008. Our XML implementation is based on the ISO 19115-2:2009 standard for geospatial metadata, with controlled vocabulary terms directly embedded as Uniform Resource Identifier (URI) references that can be validated in e.g. ISO Schematron. Our choice of the ISO standard reflects ANSI's adoption of the ISO 19115 North American Profile in 2009, and the adoption of ISO 19115 by related programs including the Integrated Ocean Drilling Program (IODP) and the SeaDataNet program in Europe. We envision a hierarchical framework where a single “cruise-level” record is linked to multiple “dataset-level” records that may be published independently. Our results published online will include a best practices guide for authoring records

  12. Error quantification of abnormal extreme high waves in Operational Oceanographic System in Korea

    Science.gov (United States)

    Jeong, Sang-Hun; Kim, Jinah; Heo, Ki-Young; Park, Kwang-Soon

    2017-04-01

    In winter season, large-height swell-like waves have occurred on the East coast of Korea, causing property damages and loss of human life. It is known that those waves are generated by a local strong wind made by temperate cyclone moving to eastward in the East Sea of Korean peninsula. Because the waves are often occurred in the clear weather, in particular, the damages are to be maximized. Therefore, it is necessary to predict and forecast large-height swell-like waves to prevent and correspond to the coastal damages. In Korea, an operational oceanographic system (KOOS) has been developed by the Korea institute of ocean science and technology (KIOST) and KOOS provides daily basis 72-hours' ocean forecasts such as wind, water elevation, sea currents, water temperature, salinity, and waves which are computed from not only meteorological and hydrodynamic model (WRF, ROMS, MOM, and MOHID) but also wave models (WW-III and SWAN). In order to evaluate the model performance and guarantee a certain level of accuracy of ocean forecasts, a Skill Assessment (SA) system was established as a one of module in KOOS. It has been performed through comparison of model results with in-situ observation data and model errors have been quantified with skill scores. Statistics which are used in skill assessment are including a measure of both errors and correlations such as root-mean-square-error (RMSE), root-mean-square-error percentage (RMSE%), mean bias (MB), correlation coefficient (R), scatter index (SI), circular correlation (CC) and central frequency (CF) that is a frequency with which errors lie within acceptable error criteria. It should be utilized simultaneously not only to quantify an error but also to improve an accuracy of forecasts by providing a feedback interactively. However, in an abnormal phenomena such as high-height swell-like waves in the East coast of Korea, it requires more advanced and optimized error quantification method that allows to predict the abnormal

  13. FEASTING BLACK HOLE BLOWS BUBBLES

    Science.gov (United States)

    2002-01-01

    A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. Known as a peculiar galaxy because of its unusual shape, NGC 4438 is in the Virgo Cluster, 50 million light-years from Earth. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box. These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths. The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate. Compared with the life of the galaxy, this bubble-blowing phase is a short-lived event. The bubble is much brighter on one side of the galaxy's center because the jet smashed into a denser amount of gas. The brighter bubble is 800 light-years tall and 800 light-years across. The observations are being presented June 5 at the American Astronomical Society meeting in Rochester, N.Y. Both pictures were taken March 24, 1999 with the Wide Field and Planetary Camera 2. False colors were used to enhance the details of the bubbles. The red regions in the picture denote the hot gas

  14. Conference: Seeing two black holes merge (with gravitational waves!) | 14 September | Uni Dufour

    CERN Multimedia

    2016-01-01

    GW150914: the first direct observation of gravitational waves from the inspiral and merger of two black holes - Conference by Prof. Bruce Allen, Albert Einstein Institute Hannover.   "Seeing two black holes merge (with gravitational waves!)" Uni Dufour - Auditorium U300 Wednesday, 14 September at 7 p.m.   Bruce Allen. (Photo: ©F. Vinken/MPG) Abstract: On 14 September 2015, the advanced LIGO gravitational wave instruments detected the gravitational wave signal emitted as two black holes, about one billion light years away from Earth, made a final few orbits around each other then merged together. This was big news around the world, because scientists have tried to make such observations for more than half a century. Before they merged, the two black holes were about 29 and 36 times as massive as the sun; after the merger was complete, a single black hole about 62 times the sun's mass was left behind. I'll describe what black holes are, how they (...

  15. ATLAS: Black hole production and decay

    CERN Document Server

    2004-01-01

    This track is an example of simulated data modelled for the ATLAS detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. These tracks would be produced if a miniature black hole was produced in the proton-proton collision. Such a small black hole would decay instantly to various particles via a process known as Hawking radiation.

  16. The reluctant father of black holes [Einstein].

    Science.gov (United States)

    Bernstein, J.

    1996-06-01

    Albert Einstein's equations of gravity are the foundation of the modern view of black holes; ironically, he used the equations in trying to prove these objects cannot exist. The author discusses quantum statistics, white dwarfs and black holes outlining the work of the key protagonists.

  17. Slowly Rotating Black Holes with Nonlinear Electrodynamics

    Directory of Open Access Journals (Sweden)

    S. H. Hendi

    2014-01-01

    4 dimensions. These solutions are asymptotically AdS and their horizon has spherical topology. We calculate the physical properties of these black holes and study their dependence on the rotation parameter a as well as the nonlinearity parameter β. In the limit β→∞, the solution describes slowly rotating AdS type black holes.

  18. Scalar absorption by charged rotating black holes

    Science.gov (United States)

    Leite, Luiz C. S.; Benone, Carolina L.; Crispino, Luís C. B.

    2017-08-01

    We compute numerically the absorption cross section of planar massless scalar waves impinging upon a Kerr-Newman black hole with different incidence angles. We investigate the influence of the black hole electric charge and angular momentum in the absorption spectrum, comparing our numerical computations with analytical results for the limits of high and low frequency.

  19. 5D Black Holes and Matrix Strings

    OpenAIRE

    Dijkgraaf, R; Verlinde, E.; Verlinde, H.

    1997-01-01

    We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA fivebrane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory.

  20. Quantum aspects of black hole entropy

    Indian Academy of Sciences (India)

    Abstract. This survey intends to cover recent approaches to black hole entropy which attempt to go beyond the standard semiclassical perspective. Quantum corrections to the semiclassical Bekenstein–. Hawking area law for black hole entropy, obtained within the quantum geometry framework, are treated in some detail.