WorldWideScience

Sample records for energy star guide

  1. THE CHANDRA VARIABLE GUIDE STAR CATALOG

    International Nuclear Information System (INIS)

    Nichols, Joy S.; Lauer, Jennifer L.; Morgan, Douglas L.; Sundheim, Beth A.; Henden, Arne A.; Huenemoerder, David P.; Martin, Eric

    2010-01-01

    Variable stars have been identified among the optical-wavelength light curves of guide stars used for pointing control of the Chandra X-ray Observatory. We present a catalog of these variable stars along with their light curves and ancillary data. Variability was detected to a lower limit of 0.02 mag amplitude in the 4000-10000 A range using the photometrically stable Aspect Camera on board the Chandra spacecraft. The Chandra Variable Guide Star Catalog (VGUIDE) contains 827 stars, of which 586 are classified as definitely variable and 241 are identified as possibly variable. Of the 586 definite variable stars, we believe 319 are new variable star identifications. Types of variables in the catalog include eclipsing binaries, pulsating stars, and rotating stars. The variability was detected during the course of normal verification of each Chandra pointing and results from analysis of over 75,000 guide star light curves from the Chandra mission. The VGUIDE catalog represents data from only about 9 years of the Chandra mission. Future releases of VGUIDE will include newly identified variable guide stars as the mission proceeds. An important advantage of the use of space data to identify and analyze variable stars is the relatively long observations that are available. The Chandra orbit allows for observations up to 2 days in length. Also, guide stars were often used multiple times for Chandra observations, so many of the stars in the VGUIDE catalog have multiple light curves available from various times in the mission. The catalog is presented as both online data associated with this paper and as a public Web interface. Light curves with data at the instrumental time resolution of about 2 s, overplotted with the data binned at 1 ks, can be viewed on the public Web interface and downloaded for further analysis. VGUIDE is a unique project using data collected during the mission that would otherwise be ignored. The stars available for use as Chandra guide stars are

  2. Managing Your Energy: An ENERGY STAR(R) Guide for Identifying Energy Savings in Manufacturing Plants

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Angelini, Tana; Masanet, Eric

    2010-07-27

    In the United States, industry spends over $100 billion annually to power its manufacturing plants. Companies also spend on maintenance, capital outlay, and energy services. Improving energy efficiency is vital to reduce these costs and increase earnings. Many cost-effective opportunities to reduce energy consumption are available, and this Energy Guide discusses energy-efficiency practices and energy-efficient technologies that can be applied over a broad spectrum of companies. Strategies in the guide address hot water and steam, compressed air, pumps, motors, fans, lighting, refrigeration, and heating, ventilation, and air conditioning. This guide includes descriptions of expected energy and cost savings, based on real-world applications, typical payback periods, and references to more detailed information. The information in this Energy Guide is intended to help energy and plant managers achieve cost-effective energy reductions while maintaining product quality. Further research on the economics of all measures--as well as on their applicability to different production practices?is needed to assess their cost effectiveness at individual plants.

  3. Energy production in stars

    International Nuclear Information System (INIS)

    Bethe, Hans.

    1977-01-01

    Energy in stars is released partly by gravitation, partly by nuclear reactions. For ordinary stars like our sun, nuclear reactions predominate. However, at the end of the life of a star very large amounts of energy are released by gravitational collapse; this can amount to as much as 10 times the total energy released nuclear reactions. The rotational energy of pulsars is a small remnant of the energy of gravitation. The end stage of small stars is generally a white dwarf, of heavy stars a neutron star of possibly a black hole

  4. Guide to the universe stars and galaxies

    CERN Document Server

    Jones, Lauren V

    2009-01-01

    This volume in the Greenwood Guides to the Universe series provides the most up-to-date understanding available of the current knowledge about stars. Scientifically sound, but written with the student in mind, Stars is an excellent first step for young people researching the exciting scientific discoveries that continue to extend our knowledge of the universe. Stars is organized thematically to help students better understand these most interesting heavenly bodies.||Stars discusses all areas of what is known about the subject. It will help student understand things such as white dwarfs, neutro

  5. Artificial guide stars for adaptive optics using unmanned aerial vehicles

    Science.gov (United States)

    Basden, A. G.; Brown, Anthony M.; Chadwick, P. M.; Clark, P.; Massey, R.

    2018-06-01

    Astronomical adaptive optics (AO) systems are used to increase effective telescope resolution. However, they cannot be used to observe the whole sky since one or more natural guide stars of sufficient brightness must be found within the telescope field of view for the AO system to work. Even when laser guide stars are used, natural guide stars are still required to provide a constant position reference. Here, we introduce a technique to overcome this problem by using rotary unmanned aerial vehicles (UAVs) as a platform from which to produce artificial guide stars. We describe the concept that relies on the UAV being able to measure its precise relative position. We investigate the AO performance improvements that can be achieved, which in the cases presented here can improve the Strehl ratio by a factor of at least 2 for a 8 m class telescope. We also discuss improvements to this technique, which is relevant to both astronomical and solar AO systems.

  6. ENERGY STAR Certified Telephones

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Telephony (cordless telephones and VoIP...

  7. ENERGY STAR Certified Dehumidifiers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Dehumidifiers that are effective as of October...

  8. ENERGY STAR Certified Televisions

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Televisions that are effective as of October 30,...

  9. ENERGY STAR Certified Boilers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Boilers that are effective as of October 1,...

  10. ENERGY STAR Certified Displays

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Displays that are effective as of July 1, 2016....

  11. StarGuides Plus

    Science.gov (United States)

    Heck, A.

    StarGuides Plus represents the most comprehensive and accurately validated collection of practical data on organizations involved in astronomy, related space sciences and other related fields. This invaluable reference source (and its companion volume, StarBriefs Plus) should be on the reference shelf of every library, organization or individual with any interest in these areas. The coverage includes relevant universities, scientific committees, institutions, associations, societies, agencies, companies, bibliographic services, data centers, museums, dealers, distributors, funding organizations, journals, manufacturers, meteorological services, national norms & standard institutes, parent associations & societies, publishers, software producers & distributors, and so on. Besides astronomy and associated space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, engineering, energetics, environment, geodesy, geophysics, information handling, management, mathematics, meteorology, optics, physics, remote sensing, and so on, are also covered where appropriate. After some thirty years in continuous compilation, verification and updating, StarGuides Plus currently gathers together some 6,000 entries from 100 countries. The information is presented in a clear, uncluttered manner for direct and easy use. For each entry, all practical data are listed: city, postal and electronic-mail addresses, telephone and fax numbers, URLs for WWW access, foundation years, numbers of members and/or numbers of staff, main activities, publications titles (with frequencies, ISS-Numbers and circulations), names and geographical coordinates of observing sites, names of planetariums, awards (prizes and/or distinctions) granted, etc. The entries are listed alphabetically in each country. An exhaustive index gives a breakdown not only by different designations and

  12. Robust remote-pumping sodium laser for advanced LIDAR and guide star applications

    Science.gov (United States)

    Ernstberger, Bernhard; Enderlein, Martin; Friedenauer, Axel; Schwerdt, Robin; Wei, Daoping; Karpov, Vladimir; Leisching, Patrick; Clements, Wallace R. L.; Kaenders, Wilhelm G.

    2015-10-01

    The performance of large ground-based optical telescopes is limited due to wavefront distortions induced by atmospheric turbulence. Adaptive optics systems using natural guide stars with sufficient brightness provide a practical way for correcting the wavefront errors by means of deformable mirrors. Unfortunately, the sky coverage of bright stars is poor and therefore the concept of laser guide stars was invented, creating an artificial star by exciting resonance fluorescence from the mesospheric sodium layer about 90 km above the earth's surface. Until now, mainly dye lasers or sumfrequency mixing of solid state lasers were used to generate laser guide stars. However, these kinds of lasers require a stationary laser clean room for operation and are extremely demanding in maintenance. Under a development contract with the European Southern Observatory (ESO) and W. M. Keck Observatory (WMKO), TOPTICA Photonics AG and its partner MPB Communications have finalized the development of a next-generation sodium guide star laser system which is available now as a commercial off-the-shelf product. The laser is based on a narrow-band diode laser, Raman fiber amplifier (RFA) technology and resonant second-harmonic generation (SHG), thus highly reliable and simple to operate and maintain. It emits > 22 W of narrow-linewidth (≈ 5 MHz) continuous-wave radiation at sodium resonance and includes a re-pumping scheme for boosting sodium return flux. Due to the SHG resonator acting as spatial mode filter and polarizer, the output is diffraction-limited with RMS wavefront error concept of line-replaceable units (LRU). A comprehensive system software, as well as an intuitive service GUI, allow for remote control and error tracking down to at least the LRU level. In case of a failure, any LRU can be easily replaced. With these fiber-based guide star lasers, TOPTICA for the first time offers a fully engineered, off-the-shelf guide star laser system for groundbased optical telescopes

  13. ENERGY STAR Certified Vending Machines

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Refrigerated Beverage Vending Machines that are...

  14. ENERGY STAR Certified Residential Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  15. ENERGY STAR Certified Residential Refrigerators

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Residential Refrigerators and Freezers that are...

  16. ENERGY STAR Certified Smart Thermostats

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Connected Thermostats that are effective as of...

  17. ENERGY STAR Certified Residential Dishwashers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 6.0 ENERGY STAR Program Requirements for Residential Dishwashers that are effective as of...

  18. ENERGY STAR Certified Commercial Dishwashers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Commercial Dishwashers that are effective as of...

  19. ENERGY STAR Certified Commercial Ovens

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.2 ENERGY STAR Program Requirements for Commercial Ovens that are effective as of...

  20. ENERGY STAR Certified Commercial Boilers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Commercial Boilers that are effective as of...

  1. ENERGY STAR Certified Ventilating Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of...

  2. ENERGY STAR Certified Imaging Equipment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Imaging Equipment that are effective as of...

  3. ENERGY STAR Certified Commercial Fryers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Commercial Fryers that are effective as of...

  4. ENERGY STAR Certified Commercial Griddles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Commercial Griddles that are effective as of May...

  5. ENERGY STAR Certified Water Coolers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Water Coolers that are effective as of February...

  6. ENERGY STAR Certified Audio Video

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Audio Video Equipment that are effective as of...

  7. ENERGY STAR Certified Roof Products

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Roof Products that are effective as of July 1,...

  8. ENERGY STAR Certified Pool Pumps

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.1 ENERGY STAR Program Requirements for Pool Pumps that are effective as of February 15,...

  9. ENERGY STAR Certified Ceiling Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1,...

  10. ENERGY STAR Certified Vending Machines

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Refrigerated Beverage Vending Machines that are effective as of March 1, 2013. A detailed listing of key efficiency criteria are available at

  11. Qualitative pre-test of Energy Star advertising : final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-01-01

    Natural Resources Canada launched a print advertising campaign and one 30-second television commercial to promote the Energy Star symbol and to acquaint the public with the program that identifies energy efficient products that reduce energy use, save money and reduce greenhouse gas emissions that contribute to climate change. The Communications Branch of Natural Resources Canada wanted to pre-test the television and print ads. Each print ad focused on a particular product category, including home comfort, appliances, electronics and office equipment. The qualitative research methodology was used in the pre-testing because it is the best learning tool for understanding the range and depth of reactions toward a subject at any given time. The findings were not quantifiable because they are not representative of the population at large. Ten focus groups were surveyed in January 2003 in 5 Canadian centres with a total of 83 participants aged 18 to 54. The target groups included people who were informed about climate change issues as well as those who were note. Participants were questioned about the Energy Star Product. Findings were consistent across all 5 locations. There was some general awareness of EnerGuide on appliances in all groups, but generally a low awareness of the Energy Star symbol. Most people did not place energy efficiency as a high priority when purchasing appliances. This report presented the main findings of attitudes towards climate change, Kyoto and energy efficiency. The reaction to the television and print ads was also included along with opinions regarding their main weaknesses and strengths. Some recommendations for improvement were also included. Samples of the print advertisements were included in both English and French. tabs., figs.

  12. ENERGY STAR Certified Uninterruptible Power Supplies

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Uninterruptible Power Supplies that are...

  13. ENERGY STAR Certified Commercial Ice Machines

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Automatic Commercial Ice Makers that are...

  14. Sky coverage modeling for the whole sky for laser guide star multiconjugate adaptive optics.

    Science.gov (United States)

    Wang, Lianqi; Andersen, David; Ellerbroek, Brent

    2012-06-01

    The scientific productivity of laser guide star adaptive optics systems strongly depends on the sky coverage, which describes the probability of finding natural guide stars for the tip/tilt wavefront sensor(s) to achieve a certain performance. Knowledge of the sky coverage is also important for astronomers planning their observations. In this paper, we present an efficient method to compute the sky coverage for the laser guide star multiconjugate adaptive optics system, the Narrow Field Infrared Adaptive Optics System (NFIRAOS), being designed for the Thirty Meter Telescope project. We show that NFIRAOS can achieve more than 70% sky coverage over most of the accessible sky with the requirement of 191 nm total rms wavefront.

  15. ENERGY STAR Certified Ceiling Fans

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=ceiling_fans.pr_crit_ceiling_fans

  16. ENERGY STAR Certified Ventilating Fans

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of October 1, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=vent_fans.pr_crit_vent_fans

  17. ENERGY STAR Certified Residential Clothes Washers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 8.0 ENERGY STAR Program Requirements for Clothes Washers that are effective as of...

  18. ENERGY STAR Certified Commercial Clothes Washers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 8.0 ENERGY STAR Program Requirements for Clothes Washers that are effective as of...

  19. ENERGY STAR Certified Commercial Steam Cookers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Commercial Steam Cookers that are effective as...

  20. ENERGY STAR Certified Small Network Equipment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Small Networking Equipment that are effective as...

  1. ENERGY STAR Certified Residential Clothes Dryers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.1 ENERGY STAR Program Requirements for Clothes Dryers that are effective as of January...

  2. ENERGY STAR Certified Light Commercial HVAC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Light Commercial HVAC that are effective as of...

  3. ENERGY STAR Certified Room Air Conditioners

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Room Air Conditioners that are effective as of...

  4. ENERGY STAR Certified Geothermal Heat Pumps

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Geothermal Heat Pumps that are effective as of...

  5. ENERGY STAR Certified Room Air Cleaners

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Room Air Cleaners that are effective as of July...

  6. Super-virtual interferometric diffractions as guide stars

    KAUST Repository

    Dai, Wei

    2011-01-01

    A significant problem in seismic imaging is seismically seeing below salt structures: large velocity contrasts and the irregular geometry of the salt-sediment interface strongly defocus both the downgoing and upgoing seismic wavefields. This can result in severely defocused migration images so as to seismically render some subsalt reserves invisible. The potential cure is a good estimate of the subsalt and salt velocity distributions, but that is also the problem: severe velocity contrasts prevent the appearance of coherent subsalt reflections in the surface records so that MVA or tomographic methods can become ineffective. We now present an interferometric method for extracting the diffraction signals that emanate from diffractors, also denoted as seismic guide stars. The signal-to-noise ratio of these interferometric diffractions is enhanced by N, where N is the number of source points coincident with the receiver points. Thus, diffractions from subsalt guide stars can then be rendered visible and so can be used for velocity analysis, migration, and focusing of subsalt reflections. Both synthetic and field data records are used to demonstrate the benefits and limitations of this method. © 2011 Society of Exploration Geophysicists.

  7. Stable dark energy stars

    International Nuclear Information System (INIS)

    Lobo, Francisco S N

    2006-01-01

    The gravastar picture is an alternative model to the concept of a black hole, where there is an effective phase transition at or near where the event horizon is expected to form, and the interior is replaced by a de Sitter condensate. In this work a generalization of the gravastar picture is explored by considering matching of an interior solution governed by the dark energy equation of state, ω ≡ p/ρ < -1/3, to an exterior Schwarzschild vacuum solution at a junction interface. The motivation for implementing this generalization arises from the fact that recent observations have confirmed an accelerated cosmic expansion, for which dark energy is a possible candidate. Several relativistic dark energy stellar configurations are analysed by imposing specific choices for the mass function. The first case considered is that of a constant energy density, and the second choice that of a monotonic decreasing energy density in the star's interior. The dynamical stability of the transition layer of these dark energy stars to linearized spherically symmetric radial perturbations about static equilibrium solutions is also explored. It is found that large stability regions exist that are sufficiently close to where the event horizon is expected to form, so that it would be difficult to distinguish the exterior geometry of the dark energy stars, analysed in this work, from an astrophysical black hole

  8. Adaptive acoustic energy delivery to near and far fields using foldable, tessellated star transducers

    Science.gov (United States)

    Zou, Chengzhe; Harne, Ryan L.

    2017-05-01

    Methods of guiding acoustic energy arbitrarily through space have long relied on digital controls to meet performance needs. Yet, more recent attention to adaptive structures with unique spatial configurations has motivated mechanical signal processing (MSP) concepts that may not be subjected to the same functional and performance limitations as digital acoustic beamforming counterparts. The periodicity of repeatable structural reconfiguration enabled by origami-inspired tessellated architectures turns attention to foldable platforms as frameworks for MSP development. This research harnesses principles of MSP to study a tessellated, star-shaped acoustic transducer constituent that provides on-demand control of acoustic energy guiding via folding-induced shape reconfiguration. An analytical framework is established to probe the roles of mechanical and acoustic geometry on the far field directivity and near field focusing of sound energy. Following validation by experiments and verification by simulations, parametric studies are undertaken to uncover relations between constituent topology and acoustic energy delivery to arbitrary points in the free field. The adaptations enabled by folding of the star-shaped transducer reveal capability for restricting sound energy to angular regions in the far field while also introducing means to modulate sound energy by three orders-of-magnitude to locations near to the transducer surface. In addition, the modeling philosophy devised here provides a valuable approach to solve general sound radiation problems for foldable, tessellated acoustic transducer constituents of arbitrary geometry.

  9. Energy Efficiency Improvement and Cost Saving Opportunities for the Petrochemical Industry - An ENERGY STAR(R) Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Neelis, Maarten; Worrell, Ernst; Masanet, Eric

    2008-09-01

    Energy is the most important cost factor in the U.S petrochemical industry, defined in this guide as the chemical industry sectors producing large volume basic and intermediate organic chemicals as well as large volume plastics. The sector spent about $10 billion on fuels and electricity in 2004. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. petrochemical industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the petrochemical industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in the petrochemical and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers in the U.S. petrochemical industry reduce energy consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures--and on their applicability to different production practices--is needed to assess their cost effectiveness at individual plants.

  10. Energy Efficiency Improvement and Cost Saving Opportunities for the Pharmaceutical Industry. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Galitsky, Christina; Chang, Sheng-chieh; Worrell, Ernst; Masanet, Eric

    2008-03-01

    The U.S. pharmaceutical industry consumes almost $1 billion in energy annually. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. pharmaceutical industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy efficient technologies that can be implemented at the component, process, system, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. pharmaceutical industry is provided along with a description of the major process steps in the pharmaceutical manufacturing process. Expected savings in energy and energy-related costs are given for many energy efficiency measures, based on case study data from real-world applications in pharmaceutical and related facilities worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers reduce energy consumption in a cost-effective manner while meeting regulatory requirements and maintaining the quality of products manufactured. At individual plants, further research on the economics of the measures?as well as their applicability to different production practices?is needed to assess potential implementation of selected technologies.

  11. IMPROVING ENERGY EFFICIENCY AND REDUCING COSTS IN THE DRINKING WATER SUPPLY INDUSTRY: An ENERGY STAR Resource Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Melody, Moya; Dunham Whitehead, Camilla; Brown, Richard

    2010-09-30

    As American drinking water agencies face higher production costs, demand, and energy prices, they seek opportunities to reduce costs without negatively affecting the quality of the water they deliver. This guide describes resources for cost-effectively improving the energy efficiency of U.S. public drinking water facilities. The guide (1) describes areas of opportunity for improving energy efficiency in drinking water facilities; (2) provides detailed descriptions of resources to consult for each area of opportunity; (3) offers supplementary suggestions and information for the area; and (4) presents illustrative case studies, including analysis of cost-effectiveness.

  12. Energy Efficiency Improvement and Cost Saving Opportunities for the Dairy Processing Industry: An ENERGY STAR? Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Brush, Adrian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Worrell, Ernst [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-10-01

    The U.S. dairy processing industry—defined in this Energy Guide as facilities engaged in the conversion of raw milk to consumable dairy products—consumes around $1.5 billion worth of purchased fuels and electricity per year. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. dairy processing industry to reduce energy consumption and greenhouse gas emissions in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. dairy processing industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures applicable to dairy processing plants are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in dairy processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. Given the importance of water in dairy processing, a summary of basic, proven measures for improving water efficiency are also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. dairy processing industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures—as well as on their applicability to different production practices—is needed to assess their cost effectiveness at individual plants.

  13. ENERGY STAR Certified Electric Vehicle Supply Equipment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Electric Vehicle Supply Equipment that are...

  14. ENERGY STAR Certified Commercial Refrigerators and Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Commercial Refrigerators and Freezers that are...

  15. ENERGY STAR Laboratory Grade Refrigerators and Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Laboratory Grade Refrigerators and Freezers that...

  16. ENERGY STAR Certified Data Center Storage

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Data Center Storage that are effective as of December 2, 2013. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/certified-products/detail/data_center_storage

  17. ENERGY STAR Certified Geothermal Heat Pumps

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Geothermal Heat Pumps that are effective as of January 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=geo_heat.pr_crit_geo_heat_pumps

  18. Neutron matter, symmetry energy and neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, Gandolfi [Los Alamos National Laboratory (LANL); Steiner, Andrew W [ORNL

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  19. Energy Efficiency Improvement and Cost Saving Opportunities for the Baking Industry: An ENERGY STAR® Guide for Plant and Energy Managers

    Energy Technology Data Exchange (ETDEWEB)

    Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Therkelsen, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Worrell, Ernst [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division

    2012-12-28

    The U.S. baking industry—defined in this Energy Guide as facilities engaged in the manufacture of commercial bakery products such as breads, rolls, frozen cakes, pies, pastries, and cookies and crackers—consumes over $800 million worth of purchased fuels and electricity per year. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in food processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. A summary of basic, proven measures for improving plant-level water efficiency is also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. baking industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures—as well as on their applicability to different production practices—is needed to assess their cost effectiveness at individual plants.

  20. Energy Efficiency Improvement and Cost Saving Opportunities for the Glass Industry. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Worrell, Ernst; Galitsky, Christina; Masanet, Eric; Graus, Wina

    2008-03-01

    The U.S. glass industry is comprised of four primary industry segments--flat glass, container glass, specialty glass, and fiberglass--which together consume $1.6 billion in energy annually. On average, energy costs in the U.S. glass industry account for around 14 percent of total glass production costs. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There is a variety of opportunities available at individual plants in the U.S. glass industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, system, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. glass industry is provided along with a description of the major process steps in glass manufacturing. Expected savings in energy and energy-related costs are given for many energy efficiency measures, based on case study data from real-world applications in glass production facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers in the U.S. glass industry reduce energy consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of the measures--as well on as their applicability to different production practices--is needed to assess potential implementation of selected technologies at individual plants.

  1. Energy star compliant voice over internet protocol (VoIP) telecommunications network including energy star compliant VoIP devices

    Science.gov (United States)

    Kouchri, Farrokh Mohammadzadeh

    2012-11-06

    A Voice over Internet Protocol (VoIP) communications system, a method of managing a communications network in such a system and a program product therefore. The system/network includes an ENERGY STAR (E-star) aware softswitch and E-star compliant communications devices at system endpoints. The E-star aware softswitch allows E-star compliant communications devices to enter and remain in power saving mode. The E-star aware softswitch spools messages and forwards only selected messages (e.g., calls) to the devices in power saving mode. When the E-star compliant communications devices exit power saving mode, the E-star aware softswitch forwards spooled messages.

  2. ENERGY STAR Unit Reports

    Data.gov (United States)

    Department of Housing and Urban Development — These quarterly Federal Fiscal Year performance reports track the ENERGY STAR qualified HOME units that Participating Jurisdictions record in HUD's Integrated...

  3. ENERGY STAR Certified Commercial Hot Food Holding Cabinet

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Commercial Hot Food Holding Cabinets that are...

  4. Energy Star Concepts for Highway Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L.

    2003-06-24

    The authors of this report, under the sponsorship of the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) Weatherization and Intergovernmental Program, have investigated the possible application of Energy Star ratings to passenger cars and light trucks. This study establishes a framework for formulating and evaluating Energy Star rating methods that is comprised of energy- and environmental-based metrics, potential vehicle classification systems, vehicle technology factors, and vehicle selection criteria. The study tests several concepts and Energy Star rating methods using model-year 2000 vehicle data--a spreadsheet model has been developed to facilitate these analyses. This study tests two primary types of rating systems: (1) an outcome-based system that rates vehicles based on fuel economy, GHG emissions, and oil use and (2) a technology-based system that rates vehicles based on the energy-saving technologies they use. Rating methods were evaluated based on their ability to select vehicles with high fuel economy, low GHG emissions, and low oil use while preserving a full range of service (size and acceleration) and body style choice. This study concludes that an Energy Star rating for passenger cars and light trucks is feasible and that several methods could be used to achieve reasonable tradeoffs between low energy use and emissions and diversity in size, performance, and body type. It also shows that methods that consider only fuel economy, GHG emissions, or oil use will not select a diverse mix of vehicles. Finally, analyses suggest that methods that encourage the use of technology only, may result in increases in acceleration power and weight rather than reductions in oil use and GHG emissions and improvements in fuel economy.

  5. Energy Efficiency Improvement and Cost Saving Opportunities for the Fruit and Vegetable Processing Industry. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Masanet, Eric; Masanet, Eric; Worrell, Ernst; Graus, Wina; Galitsky, Christina

    2008-01-01

    The U.S. fruit and vegetable processing industry--defined in this Energy Guide as facilities engaged in the canning, freezing, and drying or dehydrating of fruits and vegetables--consumes over $800 million worth of purchased fuels and electricity per year. Energy efficiency improvement isan important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. fruit and vegetable processing industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. fruit and vegetable processing industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures applicable to fruit and vegetable processing plants are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in fruit and vegetable processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. Given the importance of water in fruit and vegetable processing, a summary of basic, proven measures for improving plant-level water efficiency are also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. fruit and vegetable processing industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures--as well as on their applicability to different production

  6. Possible dark energy imprints in the gravitational wave spectrum of mixed neutron-dark-energy stars

    Energy Technology Data Exchange (ETDEWEB)

    Yazadjiev, Stoytcho S. [Department of Theoretical Physics, Faculty of Physics, St. Kliment Ohridski University of Sofia, James Bourchier Blvd. 5, 1164 Sofia (Bulgaria); Doneva, Daniela D., E-mail: yazad@phys.uni-sofia.bg, E-mail: daniela.doneva@uni-tuebingen.de [Theoretical Astrophysics, IAAT, Eberhard-Karls University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen (Germany)

    2012-03-01

    In the present paper we study the oscillation spectrum of neutron stars containing both ordinary matter and dark energy in different proportions. Within the model we consider, the equilibrium configurations are numerically constructed and the results show that the properties of the mixed neuron-dark-energy star can differ significantly when the amount of dark energy in the stars is varied. The oscillations of the mixed neuron-dark-energy stars are studied in the Cowling approximation. As a result we find that the frequencies of the fundamental mode and the higher overtones are strongly affected by the dark energy content. This can be used in the future to detect the presence of dark energy in the neutron stars and to constrain the dark-energy models.

  7. Home Performance with ENERGY STAR(R) Exchange

    Energy Technology Data Exchange (ETDEWEB)

    2003-10-01

    Handout for the Energy and Environmental Building Association's Building Solutions 2003 Conference and Expo: Chicago, Illinois, October 2003 The following summaries, provided by implementers of ''Home Performance with ENERGY STAR{reg_sign}'' around the country, are for use in the October 15 discussion during the Energy & Environmental Building Association (EEBA) Building Solutions, 2003 Conference in Chicago. The summaries and session discussions provide an overview of ''Home Performance with ENERGY STAR'', along with results and lessons learned from existing ''Home Performance'' implementers in New York, Wisconsin, Massachusetts, California, and Kansas City. Five future pilot projects set to begin in Georgia/Alabama, Idaho, Missouri, New Jersey and Texas will also be presented and discussed. Session topics will include the use of different training approaches, methods of quality assurance, and the role contractor certification plays in several of the programs. The session will conclude with a roundtable discussion of Home Performance issues by current and emerging implementers, with time for participant questions. ''Home Performance with ENERGY STAR'' uses the growing awareness and credibility of the ENERGY STAR brand to encourage and facilitate whole-house energy improvements in existing homes through self-sustaining energy efficiency programs. Whether you're a state energy official, utility program manager, contractor training professional or efficiency program implementer, you're sure to benefit from the unique presentations and networking opportunities that this session will offer.

  8. Calendar Year 2008 Program Benefits for ENERGY STAR Labeled Products

    Energy Technology Data Exchange (ETDEWEB)

    Homan, GregoryK; Sanchez, Marla; Brown, RichardE; Lai, Judy

    2010-08-24

    This paper presents current and projected savings for ENERGY STAR labeled products, and details the status of the model as implemented in the September 2009 spreadsheets. ENERGY STAR is a voluntary energy efficiency labeling program operated jointly by the Environmental Protection Agency (US EPA) and the U.S. Department of Energy (US DOE), designed to identify and promote energy-efficient products, buildings and practices. Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products, and currently labels more than thirty products, spanning office equipment, heating, cooling and ventilation equipment, commercial and residential lighting, home electronics, and major appliances. ENERGY STAR's central role in the development of regional, national and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with stakeholders. This report presents savings estimates for ENERGY STAR labeled products. We present estimates of energy, dollar, and carbon savings achieved by the program in the year 2008, annual forecasts for 2009 and 2010, and cumulative savings estimates for the period 1993 through 2008 and cumulative forecasts for the period 2009 through 2015. Through 2008 the program saved 8.8 Quads of primary energy and avoided the equivalent of 158 metric tones carbon (MtC). The forecast for the period 2009-2015 is 18.1 Quads or primary energy saved and 316 MtC emissions avoided. The sensitivity analysis bounds the best estimate of carbon avoided between 104 MtC and 213 MtC (1993 to 2008) and between 206 MtC and 444 MtC (2009 to 2015). In this report we address the following questions for ENERGY STAR labeled products: (1) How are ENERGY STAR impacts quantified; (2) What are the ENERGY STAR achievements; and (3) What are the limitations to our method?

  9. Factors influencing willingness-to-pay for the ENERGY STAR label

    International Nuclear Information System (INIS)

    Ward, David O.; Clark, Christopher D.; Jensen, Kimberly L.; Yen, Steven T.; Russell, Clifford S.

    2011-01-01

    In the United States, nearly 17% of greenhouse gas emissions come from residential energy use. Increases in energy efficiency for the residential sector can generate significant energy savings and emissions reductions. Consumer labels, such as the US Environmental Protection Agency's ENERGY STAR, promote conservation by providing consumers with information on energy usage for household appliances. This study examines how the ENERGY STAR label affects consumer preferences for refrigerators. The results of an online survey of a national sample of adults suggest that consumers are, on average, willing to pay an extra $249.82-$349.30 for a refrigerator that has been awarded the ENERGY STAR label. Furthermore, the results provide evidence that respondent willingness-to-pay was motivated by both private (energy cost savings) and public (environmental) benefits. - Research highlights: → Results of a contingent choice experiment from an online survey of a national sample suggest that consumers are, on average, willing to pay an extra $249.82-$349.30 for a refrigerator awarded the ENERGY STAR label. → Preferences for ENERGY STAR refrigerators are motivated by both private (energy cost savings) and public (environmental) benefits. → Preferences for ENERGY STAR refrigerators decrease with age but are stronger among males than among females.

  10. Factors influencing willingness-to-pay for the ENERGY STAR label

    Energy Technology Data Exchange (ETDEWEB)

    Ward, David O. [Department of Agricultural and Resource Economics, University of Tennessee, 302 Morgan Hall, 2621 Morgan Circle, Knoxville, TN 37996 (United States); Clark, Christopher D., E-mail: cdclark@utk.ed [Department of Agricultural and Resource Economics, University of Tennessee, 302 Morgan Hall, 2621 Morgan Circle, Knoxville, TN 37996 (United States); Jensen, Kimberly L.; Yen, Steven T. [Department of Agricultural and Resource Economics, University of Tennessee, 302 Morgan Hall, 2621 Morgan Circle, Knoxville, TN 37996 (United States); Russell, Clifford S. [Vanderbilt University, Nashville, TN (United States); Bowdoin College, Brunswick, ME (United States)

    2011-03-15

    In the United States, nearly 17% of greenhouse gas emissions come from residential energy use. Increases in energy efficiency for the residential sector can generate significant energy savings and emissions reductions. Consumer labels, such as the US Environmental Protection Agency's ENERGY STAR, promote conservation by providing consumers with information on energy usage for household appliances. This study examines how the ENERGY STAR label affects consumer preferences for refrigerators. The results of an online survey of a national sample of adults suggest that consumers are, on average, willing to pay an extra $249.82-$349.30 for a refrigerator that has been awarded the ENERGY STAR label. Furthermore, the results provide evidence that respondent willingness-to-pay was motivated by both private (energy cost savings) and public (environmental) benefits. - Research highlights: {yields} Results of a contingent choice experiment from an online survey of a national sample suggest that consumers are, on average, willing to pay an extra $249.82-$349.30 for a refrigerator awarded the ENERGY STAR label. {yields} Preferences for ENERGY STAR refrigerators are motivated by both private (energy cost savings) and public (environmental) benefits. {yields} Preferences for ENERGY STAR refrigerators decrease with age but are stronger among males than among females.

  11. Nuclear processing during star formation

    International Nuclear Information System (INIS)

    Newman, M.J.

    1978-01-01

    A preliminary survey was conducted of the thermonuclear energy release expected during star formation. The destruction of primordial deuterium provides substantial amounts of energy at surprisingly low temperatures, and must be considered in any meaningful treatment of star formation carried to stages in which the internal temperature exceeds a few hundred thousand degrees. Significant energy generation from consumption of initial lithium requires higher temperatures, of the order of a few million degrees. Depletion of primordial beryllium and boron may never provide an important energy source. The approach to equilibrium of the carbon--nitrogen cycle is dominant at temperatures approaching those characteristic of the central regions of main sequence stars. The present calculation should serve as a useful guide in choosing those nuclear processes to be included in a more detailed study. 8 figures, 2 tables

  12. Kaon condensates, nuclear symmetry energy and cooling of neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, S. E-mail: kubis@alf.ifj.edu.pl; Kutschera, M

    2003-06-02

    The cooling of neutron stars by URCA processes in the kaon-condensed neutron star matter for various forms of nuclear symmetry energy is investigated. The kaon-nucleon interactions are described by a chiral Lagrangian. Nuclear matter energy is parametrized in terms of the isoscalar contribution and the nuclear symmetry energy in the isovector sector. High density behaviour of nuclear symmetry energy plays an essential role in determining the composition of the kaon-condensed neutron star matter which in turn affects the cooling properties. We find that the symmetry energy which decreases at higher densities makes the kaon-condensed neutron star matter fully protonized. This effect inhibits strongly direct URCA processes resulting in slower cooling of neutron stars as only kaon-induced URCA cycles are present. In contrast, for increasing symmetry energy direct URCA processes are allowed in the almost whole density range where the kaon condensation exists.

  13. Kaon condensates, nuclear symmetry energy and cooling of neutron stars

    International Nuclear Information System (INIS)

    Kubis, S.; Kutschera, M.

    2003-01-01

    The cooling of neutron stars by URCA processes in the kaon-condensed neutron star matter for various forms of nuclear symmetry energy is investigated. The kaon-nucleon interactions are described by a chiral Lagrangian. Nuclear matter energy is parametrized in terms of the isoscalar contribution and the nuclear symmetry energy in the isovector sector. High density behaviour of nuclear symmetry energy plays an essential role in determining the composition of the kaon-condensed neutron star matter which in turn affects the cooling properties. We find that the symmetry energy which decreases at higher densities makes the kaon-condensed neutron star matter fully protonized. This effect inhibits strongly direct URCA processes resulting in slower cooling of neutron stars as only kaon-induced URCA cycles are present. In contrast, for increasing symmetry energy direct URCA processes are allowed in the almost whole density range where the kaon condensation exists

  14. ENERGY STAR Certified Products - Lighting

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set contains a simplified list of all currently certified ENERGY STAR Lighting models with basic model information collected across all product categories...

  15. Star Ware: The Amateur Astronomer's Guide to Choosing, Buying, and Using Telescopes and Accessories, 3rd Edition

    Science.gov (United States)

    Harrington, Philip S.

    2002-05-01

    Praise for the Second Edition of Star Ware "Star Ware is still a tour de force that any experienced amateur will find invaluable, and which hardware-minded beginners will thoroughly enjoy." -Robert Burnham, Sky & Telescope magazine "Star Ware condenses between two covers what would normally take a telescope buyer many months to accumulate." -John Shibley, Astronomy magazine Now more than ever, the backyard astronomer has a dazzling array of choices when it comes to telescope shopping-which can make choosing just the right sky-watching equipment a formidable challenge. In this revised and updated edition of Star Ware, the essential guide to buying astronomical equipment, award-winning astronomy writer Philip Harrington does the work for you, analyzing and exploring today's astronomy market and offering point-by-point comparisons of everything you need. Whether you're an experienced amateur astronomer or just getting started, Star Ware, Third Edition will prepare you to explore the farthest reaches of space with: Extensive, expanded reviews of leading models and accessories, including dozens of new products, to help you buy smart A clear, step-by-step guide to all aspects of purchasing everything from telescopes and binoculars to filters, mounts, lenses, cameras, film, star charts, guides and references, and much more Eleven new do-it-yourself projects for making unique astronomical equipment at home Easy tips on maintenance, photography, and star-mapping to help you get the most out of your telescope Lists of where to find everything astronomical, including Internet sites and Web resources; distributors, dealers, and conventions; and corporate listings for products and services

  16. Advanced Energy Retrofit Guide Office Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guopeng; Liu, Bing; Wang, Weimin; Zhang, Jian; Athalye, Rahul A.; Moser, Dave; Crowe, Eliot; Bengtson, Nick; Effinger, Mark; Webster, Lia; Hatten, Mike

    2011-09-27

    The Advanced Energy Retrofit Guide for Office Buildings is a component of the Department of Energy’s Advanced Energy Retrofit Guides for Existing Buildings series. The aim of the guides is to facilitate a rapid escalation in the number of energy efficiency projects in existing buildings and to enhance the quality and depth of those projects. By presenting general project planning guidance as well as financial payback metrics for the most common energy efficiency measures, these guides provide a practical roadmap to effectively planning and implementing performance improvements for existing buildings.

  17. Advanced Energy Retrofit Guide Retail Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guopeng; Liu, Bing; Zhang, Jian; Wang, Weimin; Athalye, Rahul A.; Moser, Dave; Crowe, Eliot; Bengtson, Nick; Effinger, Mark; Webster, Lia; Hatten, Mike

    2011-09-19

    The Advanced Energy Retrofit Guide for Retail Buildings is a component of the Department of Energy’s Advanced Energy Retrofit Guides for Existing Buildings series. The aim of the guides is to facilitate a rapid escalation in the number of energy efficiency projects in existing buildings and to enhance the quality and depth of those projects. By presenting general project planning guidance as well as financial payback metrics for the most common energy efficiency measures, these guides provide a practical roadmap to effectively planning and implementing performance improvements for existing buildings.

  18. Savings potential of ENERGY STAR (registered trademark) voluntary labeling programs

    International Nuclear Information System (INIS)

    Webber, Carrie A.; Brown, Richard E.

    1998-01-01

    In 1993 the U.S. Environmental Protection Agency (EPA) introduced ENERGY STAR (registered trademark), a voluntary labeling program designed to identify and promote energy-efficient products. Since then EPA, now in partnership with the U.S. Department of Energy (DOE), has introduced programs for more than twenty products, spanning office equipment, residential heating and cooling equipment, new homes, commercial and residential lighting, home electronics, and major appliances. We present potential energy, dollar and carbon savings forecasts for these programs for the period 1998 to 2010. Our target market penetration case represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide results under the assumption of 100% market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period. Finally, we assess the sensitivity of our target penetration case forecasts to greater or lesser marketing success by EPA and DOE, lower-than-expected future energy prices, and higher or lower rates of carbon emission by electricity generators. The potential savings of ENERGY STAR are substantial. If all purchasers chose Energy Star-compliant products instead of standard efficiency products over the next 15 years, they would save more than$100 billion on their energy bills during those 15 years. (Bill savings are in 1995 dollars, discounted at a 4% real discount rate.)

  19. The Laser Guide Star System for Adaptive Optics at Subaru Telescope

    Science.gov (United States)

    Hayano, Y.; Saito, Y.; Ito, M.; Saito, N.; Akagawa, K.; Takazawa, A.; Ito, M.; Wada, S.; Takami, H.; Iye, M.

    We report on the current status of developing the new laser guide star (LGS) system for the Subaru adaptive optics (AO) system. We have three major subsystems: the laser unit, the relay optical fiber and the laser launching telescope. A 4W-class all-solid-state 589nm laser has been developed as a light source for sodium laser guide star. We use two mode-locked Nd:YAG lasers operated at the wavelength of 1064nm and 1319nm to generate sum-frequency conversion into 589nm. The side-LD pumped configuration is used for the mode-locked Nd:YAG lasers. We have carefully considered the thermal lens effect in the cavity to achieve a high beam quality with TEM00; M2 = 1.06. The mode-locked frequency is selected at 143 MHz. We obtained the output powers of 16.5 W and 5.0 W at 1064nm and 1319 nm. Sum frequency generated by mixing two synchronized Nd:YAG mode-locked pulsed beams is precisely tuned to the sodium D2 line by thermal control of the etalon in the 1064nm Nd:YAG laser by observing the maximum fluorescence intensity of heated sodium vapor cell. The maximum output power at 589.159 nm reaches to 4.6 W using a PPMgOSLT crystal as a nonlinear optical crystal. And the output power can be maintained within a stability of +/- 1.2% for more than 3 days without optical damage. We developed a single-mode photonic crystal fiber (PCF) to relay the laser beam from laser clean room, in which the laser unit is located on the Nasmyth platform, to the laser launching telescope mounted behind the secondary mirror of Subaru Telescope. The photonic crystal fiber has solid pure silica core with the mode field diameter of 14 micron, which is relatively larger than that of the conventional step-index type single mode fiber. The length of the PCF is 35m and transmission loss due to the pure silica is 10dB/km at 589nm, which means PCF transmits 92% of the laser beam. We have preliminary achieved 75% throughput in total. Small mode-locked pulse width in time allows us to transmit the high

  20. 2004 status report: Savings estimates for the Energy Star(R)voluntarylabeling program

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie A.; Brown, Richard E.; McWhinney, Marla

    2004-03-09

    ENERGY STAR(R) is a voluntary labeling program designed toidentify and promote energy-efficient products, buildings and practices.Operated jointly by the Environmental Protection Agency (EPA) and theU.S. Department of Energy (DOE), ENERGY STAR labels exist for more thanthirty products, spanning office equipment, residential heating andcooling equipment, commercial and residential lighting, home electronics,and major appliances. This report presents savings estimates for a subsetof ENERGY STAR labeled products. We present estimates of the energy,dollar and carbon savings achieved by the program in the year 2003, whatwe expect in 2004, and provide savings forecasts for two marketpenetration scenarios for the periods 2004 to 2010 and 2004 to 2020. Thetarget market penetration forecast represents our best estimate of futureENERGY STAR savings. It is based on realistic market penetration goalsfor each of the products. We also provide a forecast under the assumptionof 100 percent market penetration; that is, we assume that all purchasersbuy ENERGY STAR-compliant products instead of standard efficiencyproducts throughout the analysis period.

  1. Adaptive optics and laser guide stars at Lick observatory

    Energy Technology Data Exchange (ETDEWEB)

    Brase, J.M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    For the past several years LLNL has been developing adaptive optics systems for correction of both atmospheric turbulence effects and thermal distortions in optics for high-power lasers. Our early work focused on adaptive optics for beam control in laser isotope separation and ground-based free electron lasers. We are currently developing innovative adaptive optics and laser systems for sodium laser guide star applications at the University of California`s Lick and Keck Observeratories. This talk will describe our adaptive optics technology and some of its applications in high-resolution imaging and beam control.

  2. Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Blinde, Paul; Neelis, Maarten; Blomen, Eliane; Masanet, Eric

    2010-10-21

    Energy is an important cost factor in the U.S iron and steel industry. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. iron and steel industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the structure, production trends, energy consumption, and greenhouse gas emissions of the iron and steel industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in the steel and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers in the U.S. iron and steel industry reduce energy consumption and greenhouse gas emissions in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures?and on their applicability to different production practices?is needed to assess their cost effectiveness at individual plants.

  3. Cosmic-ray energy densities in star-forming galaxies

    Directory of Open Access Journals (Sweden)

    Persic Massimo

    2017-01-01

    Full Text Available The energy density of cosmic ray protons in star forming galaxies can be estimated from π0-decay γ-ray emission, synchrotron radio emission, and supernova rates. To galaxies for which these methods can be applied, the three methods yield consistent energy densities ranging from Up ~ 0.1 − 1 eV cm−3 to Up ~ 102 − 103 eV cm−3 in galaxies with low to high star-formation rates, respectively.

  4. Tip-tilt compensation: Resolution limits for ground-based telescopes using laser guide star adaptive optics

    International Nuclear Information System (INIS)

    Olivier, S.S.; Max, C.E.; Gavel, D.T.; Brase, J.M.

    1992-01-01

    The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a small angle. Given the observed distribution of stars in the sky, the need to find a tilt reference star quite close to the object restricts the fraction of the sky over which long-exposure images with diffraction limited resolution can be obtained. In this paper, the authors present a comprehensive performance analysis of tip-tilt compensation systems that use a natural star as a tilt reference, taking into account properties of the atmosphere and of the Galactic stellar populations, and optimizing over the system operating parameters to determine the fundamental limits to the long-exposure resolution. Their results show that for a ten meter telescope on Mauna Kea, if the image of the tilt reference star is uncorrected, about half the sky can be imaged in the V band with long-exposure resolution less than 60 milli-arc-seconds (mas), while if the image of the tilt reference star is fully corrected, about half the sky can be imaged in the V band with long-exposure resolution less than 16 mas. Furthermore, V band images long-exposure resolution of less than 16 mas may be obtained with a ten meter telescope on Mauna Kea for unresolved objects brighter than magnitude 22 that are fully corrected by a laser guide star adaptive optics system. This level of resolution represents about 70% of the diffraction limit of a ten meter telescope in the V band and is more than a factor of 45 better than the median seeing in the V band on Mauna Kea

  5. Nuclear symmetry energy and stability of matter in neutron stars

    International Nuclear Information System (INIS)

    Kubis, Sebastian

    2007-01-01

    It is shown that the nuclear symmetry energy is the key quantity in the stability consideration in neutron star matter. The symmetry energy controls the position of crust-core transition and also may lead to new effects in the inner core of neutron star

  6. Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marla Christine; Homan, Gregory; Brown, Richard

    2008-10-31

    ENERGY STAR is a voluntary energy efficiency-labeling program operated jointly by the United States Department of Energy and the United States Environmental Protection Agency (US EPA). Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products. ENERGY STAR's central role in the development of regional, national, and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with committed stakeholders. Through 2007, the program saved 7.1 Quads of primary energy and avoided 128 MtC equivalent. The forecast shows that the program is expected to save 21.2 Quads of primary energy and avoid 375 MtC equivalent over the period 2008-2015. The sensitivity analysis bounds the best estimate of carbon avoided between 84 MtC and 172 MtC (1993 to 2007) and between 243 MtC and 519 MtC (2008 to 2015).

  7. Reducing Energy Use in Existing Homes by 30%: Learning From Home Performance with ENERGY STAR

    Energy Technology Data Exchange (ETDEWEB)

    Liaukus, C. [Building America Research Alliance (BARA), Kent, WA (United States)

    2014-12-01

    The improvement of existing homes in the United States can have a much greater impact on overall residential energy use than the construction of highly efficient new homes. There are over 130 million existing housing units in the U.S., while annually new construction represents less than two percent of the total supply (U.S. Census Bureau, 2013). Therefore, the existing housing stock presents a clear opportunity and responsibility for Building America (BA) to guide the remodeling and retrofit market toward higher performance existing homes. There are active programs designed to improve the energy performance of existing homes. Home Performance with ENERGY STAR (HPwES) is a market-rate program among them. BARA's research in this project verified that the New Jersey HPwES program is achieving savings in existing homes that meet or exceed BA's goal of 30%. Among the 17 HPwES projects with utility data included in this report, 15 have actual energy savings ranging from 24% to 46%. Further, two of the homes achieved that level of energy savings without the costly replacement of heating and cooling equipment, which indicates that less costly envelope packages could be offered to consumers unable to invest in more costly mechanical packages, potentially creating broader market impact.

  8. Calendar Year 2009 Program Benefits for ENERGY STAR Labeled Products

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Gregory K; Sanchez, Marla C.; Brown, Richard E.

    2010-11-15

    ENERGY STAR is a voluntary energy efficiency labeling program operated jointly by the Environmental Protection Agency (US EPA) and the U.S. Department of Energy (US DOE), designed to identify and promote energy-efficient products, buildings and practices. Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products, and currently labels more than thirty products, spanning office equipment, heating, cooling and ventilation equipment, commercial and residential lighting, home electronics, and major appliances. ENERGY STAR's central role in the development of regional, national and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with stakeholders. This report presents savings estimates from the use ENERGY STAR labeled products. We present estimates of energy, dollar, and carbon savings achieved by the program in the year 2009, annual forecasts for 2010 and 2011, and cumulative savings estimates for the period 1993 through 2009 and cumulative forecasts for the period 2010 through 2015. Through 2009 the program saved 9.5 Quads of primary energy and avoided the equivalent of 170 million metric tons carbon (MMTC). The forecast for the period 2009-2015 is 11.5 Quads or primary energy saved and 202 MMTC emissions avoided. The sensitivity analysis bounds the best estimate of carbon avoided between 110 MMTC and 231 MMTC (1993 to 2009) and between 130 MMTC and 285 MMTC (2010 to 2015).

  9. EPA ENERGY STAR: Tackling Growth in Home Electronics and Small Appliances

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marla Christine; Brown, Richard; Homan, Gregory

    2008-11-17

    Over a decade ago, the electricity consumption associated with home electronics and other small appliances emerged onto the global energy policy landscape as one of the fastest growing residential end uses with the opportunity to deliver significant energy savings. As our knowledge of this end use matures, it is essential to step back and evaluate the degree to which energy efficiency programs have successfully realized energy savings and where savings opportunities have been missed.For the past fifteen years, we have quantified energy, utility bill, and carbon savings for US EPA?s ENERGY STAR voluntary product labeling program. In this paper, we present a unique look into the US residential program savings claimed to date for EPA?s ENERGY STAR office equipment, consumer electronics, and other small household appliances as well as EPA?s projected program savings over the next five years. We present a top-level discussion identifying program areas where EPA?s ENERGY STAR efforts have succeeded and program areas where ENERGY STAR efforts did not successfully address underlying market factors, technology issues and/or consumer behavior. We end by presenting the magnitude of ?overlooked? savings.

  10. 2005 Status Report Savings Estimates for the ENERGY STAR(R)Voluntary Labeling Program

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie A.; Brown, Richard E.; Sanchez, Marla

    2006-03-07

    ENERGY STAR(R) is a voluntary labeling program designed toidentify and promote energy-efficient products, buildings and practices.Operated jointly by the Environmental Protection Agency (EPA) and theU.S. Department of Energy (DOE), Energy Star labels exist for more thanforty products, spanning office equipment, residential heating andcooling equipment, commercial and residential lighting, home electronics,and major appliances. This report presents savings estimates for a subsetof ENERGY STAR labeled products. We present estimates of the energy,dollar and carbon savings achieved by the program in the year 2004, whatwe expect in 2005, and provide savings forecasts for two marketpenetration scenarios for the periods 2005 to 2010 and 2005 to 2020. Thetarget market penetration forecast represents our best estimate of futureENERGY STAR savings. It is based on realistic market penetration goalsfor each of the products. We also provide a forecast under the assumptionof 100 percent market penetration; that is, we assume that all purchasersbuy ENERGY STAR-compliant products instead of standard efficiencyproducts throughout the analysis period.

  11. 2007 Status Report: Savings Estimates for the ENERGY STAR(R)VoluntaryLabeling Program

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marla; Webber, Carrie A.; Brown, Richard E.; Homan,Gregory K.

    2007-03-23

    ENERGY STAR(R) is a voluntary labeling program designed toidentify and promote energy-efficient products, buildings and practices.Operated jointly by the Environmental Protection Agency (EPA) and theU.S. Department of Energy (DOE), ENERGY STAR labels exist for more thanthirty products, spanning office equipment, residential heating andcooling equipment, commercial and residential lighting, home electronics,and major appliances. This report presents savings estimates for a subsetof ENERGY STAR labeled products. We present estimates of the energy,dollar and carbon savings achieved by the program in the year 2006, whatwe expect in 2007, and provide savings forecasts for two marketpenetration scenarios for the periods 2007 to 2015 and 2007 to 2025. Thetarget market penetration forecast represents our best estimate of futureENERGY STAR savings. It is based on realistic market penetration goalsfor each of the products. We also provide a forecast under the assumptionof 100 percent market penetration; that is, we assume that all purchasersbuy ENERGY STAR-compliant products instead of standard efficiencyproducts throughout the analysis period.

  12. Savings estimates for the Energy Star(registered trademark) voluntary labeling program

    International Nuclear Information System (INIS)

    Webber, Carrie A.; Brown, Richard E.; Koomey, Jonathan G.

    2000-01-01

    ENERGY STAR7 is a voluntary labeling program designed to identify and promote energy-efficient products. Operated jointly by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), ENERGY STAR labels exist for more than twenty products, spanning office equipment, residential heating and cooling equipment, new homes, commercial and residential lighting, home electronics, and major appliances. We present estimates of the energy, dollar and carbon savings already achieved by the program and provide savings forecasts for several market penetration scenarios for the period 2001 to 2010. The target market penetration forecast represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide a forecast under the assumption of 100 percent market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period. Finally, we assess the sensitivity of our target penetration case forecasts to greater or lesser marketing success by EPA and DOE, lower-than-expected future energy prices, and higher or lower rates of carbon emissions by electricity generators

  13. Effects of laser beam propagation and saturation on the spatial shape of sodium laser guide stars.

    Science.gov (United States)

    Marc, Fabien; Guillet de Chatellus, Hugues; Pique, Jean-Paul

    2009-03-30

    The possibility to produce diffraction-limited images by large telescopes through Adaptive Optics is closely linked to the precision of measurement of the position of the guide star on the wavefront sensor. In the case of laser guide stars, many parameters can lead to a strong distortion on the shape of the LGS spot. Here we study the influence of both the saturation of the sodium layer excited by different types of lasers, the spatial quality of the laser mode at the ground and the influence of the atmospheric turbulence on the upward propagation of the laser beam. Both shape and intensity of the LGS spot are found to depend strongly on these three effects with important consequences on the precision on the wavefront analysis.

  14. Guide to energy management

    International Nuclear Information System (INIS)

    2006-03-01

    A systematic and practical guide to energy management. Energy management signifies here a methodology concerning how an organisation continuously can work on improving all aspects of energy efficiency and energy consumption. Focus is on how energy management can be implemented in the companies already existing environment management systems. Useful recommendations and examples are provided (ml)

  15. 77 FR 46089 - Agency Information Collection Activities; Proposed Collection; Comment Request; EPA's ENERGY STAR...

    Science.gov (United States)

    2012-08-02

    ... Activities; Proposed Collection; Comment Request; EPA's ENERGY STAR Program in the Commercial and Industrial... this action are participants in EPA's ENERGY STAR Program in the Commercial and Industrial Sectors. Title: Information Collection Activities Associated with EPA's ENERGY STAR Program in the Commercial and...

  16. 2003 status report savings estimates for the energy star(R)voluntary labeling program

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie A.; Brown, Richard E.; McWhinney, Marla

    2004-11-09

    ENERGY STAR(R) is a voluntary labeling program designed to identify and promote energy-efficient products, buildings and practices. Operated jointly by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), ENERGY STAR labels exist for more than thirty products, spanning office equipment, residential heating and cooling equipment, commercial and residential lighting, home electronics, and major appliances. This report presents savings estimates for a subset of ENERGY STAR program activities, focused primarily on labeled products. We present estimates of the energy, dollar and carbon savings achieved by the program in the year 2002, what we expect in 2003, and provide savings forecasts for two market penetration scenarios for the period 2003 to 2020. The target market penetration forecast represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide a forecast under the assumption of 100 percent market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period.

  17. 2002 status report: Savings estimates for the ENERGY STAR(R) voluntary labeling program

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie A.; Brown, Richard E.; McWhinney, Marla; Koomey, Jonathan

    2003-03-03

    ENERGY STAR [registered trademark] is a voluntary labeling program designed to identify and promote energy-efficient products, buildings and practices. Operated jointly by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), ENERGY STAR labels exist for more than thirty products, spanning office equipment, residential heating and cooling equipment, commercial and residential lighting, home electronics, and major appliances. This report presents savings estimates for a subset of ENERGY STAR program activities, focused primarily on labeled products. We present estimates of the energy, dollar and carbon savings achieved by the program in the year 2001, what we expect in 2002, and provide savings forecasts for two market penetration scenarios for the period 2002 to 2020. The target market penetration forecast represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide a forecast under the assumption of 100 percent market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period.

  18. User guide to power management for PCs and monitors

    Energy Technology Data Exchange (ETDEWEB)

    Nordman, B.; Piette, M.A.; Kinney, K.; Webber, C. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.

    1997-01-01

    Power management of personal computers (PCs) and monitors has the potential to save significant amounts of electricity as well as deliver other economic and environmental benefits. The Environmental Protection Agency`s ENERGY STAR{reg_sign} program has transformed the PC market so that equipment capable of power management is now widely available. However, previous studies have found that many Energy Star compliant computer systems are not accomplishing energy savings. The principal reasons for this are systems not being enabled for power management or a circumstance that prevents power management from operating. This guide is intended to provide information to computer support workers to increase the portion of systems that successfully power manage. The guide introduces power management concepts and the variety of benefits that power management can bring. It then explains how the parts of a computer system work together to enter and leave power management states. Several common computer system types are addressed, as well as the complications that networks bring to power management. Detailed instructions for checking and configuring several system types are provided, along with trouble shooting advice. The guide concludes with a discussion of how to purchase Energy Star compliant systems and future directions for power management of PCs and related equipment.

  19. Constraints on the symmetry energy from neutron star observations

    International Nuclear Information System (INIS)

    Newton, W G; Gearheart, M; Wen, De-Hua; Li, Bao-An

    2013-01-01

    The modeling of many neutron star observables incorporates the microphysics of both the stellar crust and core, which is tied intimately to the properties of the nuclear matter equation of state (EoS). We explore the predictions of such models over the range of experimentally constrained nuclear matter parameters, focusing on the slope of the symmetry energy at nuclear saturation density L. We use a consistent model of the composition and EoS of neutron star crust and core matter to model the binding energy of pulsar B of the double pulsar system J0737-3039, the frequencies of torsional oscillations of the neutron star crust and the instability region for r-modes in the neutron star core damped by electron-electron viscosity at the crust-core interface. By confronting these models with observations, we illustrate the potential of astrophysical observables to offer constraints on poorly known nuclear matter parameters complementary to terrestrial experiments, and demonstrate that our models consistently predict L < 70 MeV.

  20. Hot neutron stars at birth and energy release

    International Nuclear Information System (INIS)

    Takatsuka, Tatsuyuki

    1994-01-01

    For the discussion of hot neutron stars at birth, it is necessary to calculate the equation of state for a so-called 'supernova matter' consisting of a neutron-rich nuclear matter and degenerated leptons. One of the aims of this paper is to obtain the realistic results for the equation of state. In 10-20s after the birth, new born hot neutron stars are cooled down by neutrino diffusion process, and gradually contract to usual cold neutron starts. It is another aim of this paper to determine how much energy is released during this cooling stage. The points to which attention was paid are explained. A three-nucleon interaction was introduced phenomenologically, as a two-nucleon interaction is insufficient to satisfy the empirical saturation property of symmetric nuclear matters. The separation of uncertain part from well-known part has the merit to clarify the dependence of the results on the present theoretical uncertainties. The validity of the simplified calculation as an approximation for the exact calculation is discussed. The results by both calculations were compared for the case of hot symmetric nuclear matters. The comparison of the density profiles for a hot neutron star and a cold neutron star is shown. The binding energy for hot and cold neutron stars was plotted. These results are examined. (K.I.)

  1. Energy upgrades as financial or strategic investment? Energy Star property owners and managers improving building energy performance

    International Nuclear Information System (INIS)

    Gliedt, Travis; Hoicka, Christina E.

    2015-01-01

    Highlights: • Energy Star property owners/managers view energy as strategic or financial investments. • Energy performance improvements and motivations differ by property type. • Energy projects are most often funded by internal cash reserves. • Motivations and funding sources differ by type of energy project. • Environmental sustainability is an important criterion in many energy projects. - Abstract: Due to its significant carbon footprint and cost-effectiveness for upgrades, the commercial property sector is important for climate change mitigation. Although barriers to energy system changes, such as funding, financing and information, are well recognized, Energy Star property owners and managers are successfully overcoming these barriers and instigating energy efficiency upgrades, renewable energy installations, and behavior and management programs. To examine the decision-making process that leads to energy performance improvements, a national survey of property owners and management organizations of buildings that earned an Energy Star score of 75 or higher was conducted. The extent to which energy upgrades were considered strategic investments motivated by environmental sustainability or corporate social responsibility, or financial investments motivated by payback period or return-on-investment criteria, was contingent upon the property type and type of energy project. Environmental sustainability was found to be an important motivation for energy projects in office spaces in general, but in the case of smaller office spaces was often combined with motivations for corporate social responsibility. Energy projects on education properties were motivated by financial investment. Building envelope and mechanical efficiency upgrades were considered financial investments, while renewable energy, green roofs, and water conservation technologies were considered environmental sustainability initiatives

  2. International nuclear energy guide

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Separate abstracts are included for each of the papers presented concerning current technical and economical events in the nuclear field. Twelve papers have been abstracted and input to the data base. The ''international nuclear energy guide'' gives a general directory of the name, the address and the telephone number of the companies and bodies quoted in this guide; a chronology of the main events 1982. The administrative and professional organization, the nuclear courses and research centers in France are presented, as also the organization of protection and safety, and of nuclear fuel cycle. The firms concerned by the design and the construction of NSSS and the allied nuclear firms are also presented. The last part of this guide deals with the nuclear energy in the world: descriptive list of international organizations, and, the nuclear activities throughout the world (alphabetical order by countries) [fr

  3. The NexStar user’s guide II for the LCM, SLT, SE, CPC, SkyProdigy, and Astro Fi

    CERN Document Server

    Swanson, Michael

    2017-01-01

    As with the first edition, this book is a thorough reference for the telescope models covered. The original NexStar User's Guide has remained very popular among the NexStar owner community. This updated edition has been completely rewritten to cover all current Celestron altitude-azimuth computerized telescopes (German EQ mounts are not discussed). Detailed information on the alignment and operation of these ‘scopes provides a complete reference that expands greatly upon the manuals provided by Celestron. It also serves as a guide to buying the most suitable model for a variety of budgets and interests. Connecting and controlling the telescope with PCs, Macs, tablets, and smartphones is covered in great detail. A chapter is dedicated to updating the firmware in the hand control, mount, and StarSense camera (an optional accessory). Chapters on accessories, collimation, maintenance, and troubleshooting tips round out the book’s extensive coverage of the subject matter. Additionally, the book offers a brief,...

  4. Savings estimates for the ENERGY STAR (registered trademark) voluntary labeling program: 2001 status report

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Carrie A.; Brown, Richard E.; Mahajan, Akshay; Koomey, Jonathan G.

    2002-02-15

    ENERGY STAR(Registered Trademark) is a voluntary labeling program designed to identify and promote energy-efficient products, buildings and practices. Operated jointly by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), ENERGY STAR labels exist for more than thirty products, spanning office equipment, residential heating and cooling equipment, commercial and residential lighting, home electronics, and major appliances. This report presents savings estimates for a subset of ENERGY STAR program activities, focused primarily on labeled products. We present estimates of the energy, dollar and carbon savings achieved by the program in the year 2000, what we expect in 2001, and provide savings forecasts for two market penetration scenarios for the period 2001 to 2020. The target market penetration forecast represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide a forecast under the assumption of 100 percent market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period.

  5. 11 New England Organizations Recognized as Energy Star Partners

    Science.gov (United States)

    The U.S. Environmental Protection Agency’s New England office, along with the U.S. Department of Energy are honoring 11 ENERGY STAR partners for their outstanding contributions to public health and the environment.

  6. Measuring energy-saving retrofits: Experiences from the Texas LoanSTAR program

    Energy Technology Data Exchange (ETDEWEB)

    Haberl, J.S.; Reddy, T.A.; Claridge, D.E.; Turner, W.D.; O`Neal, D.L.; Heffington, W.M. [Texas A and M Univ., College Station, TX (United States). Energy Systems Lab.

    1996-02-01

    In 1988 the Governor`s Energy Management Center of Texas received approval from the US Department of Energy to establish a $98.6 million state-wide retrofit demonstration revolving loan program to fund energy-conserving retrofits in state, public school, and local government buildings. As part of this program, a first-of-its-kind, statewide Monitoring and Analysis Program (MAP) was established to verify energy and dollar savings of the retrofits, reduce energy costs by identifying operational and maintenance improvements, improve retrofit selection in future rounds of the LoanSTAR program, and initiate a data base of energy use in institutional and commercial buildings located in Texas. This report discusses the LoanSTAR MAP with an emphasis on the process of acquiring and analyzing data to measure savings from energy conservation retrofits when budgets are a constraint. This report includes a discussion of the program structure, basic measurement techniques, data archiving and handling, data reporting and analysis, and includes selected examples from LoanSTAR agencies. A summary of the program results for the first two years of monitoring is also included.

  7. The Sun - From the star to domestic energy

    International Nuclear Information System (INIS)

    2009-06-01

    Considered as a star and a deity, for a long period of time the Sun was thought to be another planet, whereas the word 'star' was reserved for all the brilliant points of light in the night sky. The Sun's status as a star in the sense of 'an astral body producing and emitting energy' was firmly established only at the beginning of the 20. century. Today astrophysicists are revealing more and more secrets of the fusion burning region located in its core. It is thanks to the Sun that life has appeared and evolved on Earth; it controls the cycle of 'For the last 4.6 million years the Sun has being providing us with light and heat. Today it is man's ambition to control this energy source'. The seasons and provides us with heat and light. But what exactly is the nature and origin of this prodigious energy source, with which man attempts to provide warmth and produce electricity? What is happening in this gigantic ball of fire, impossible to observe without protective glasses? And finally, how long will it continue to shine? Questions such as these took many centuries to be solved and will continue to be the subject of research for a long time to come. (authors)

  8. Energy Design Guides for Army Barracks: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Deru, M.; Zhivov, A.; Herron, D.

    2008-08-01

    The U.S. Army Corps of Engineers and NREL are developing target energy budgets and design guides to achieve 30% energy savings. This paper focuses the design guide for one type of barracks called unaccompanied enlisted personal housing.

  9. A design guide for energy-efficient research laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Wishner, N.; Chen, A.; Cook, L. [eds.; Bell, G.C.; Mills, E.; Sartor, D.; Avery, D.; Siminovitch, M.; Piette, M.A.

    1996-09-24

    This document--A Design Guide for Energy-Efficient Research Laboratories--provides a detailed and holistic framework to assist designers and energy managers in identifying and applying advanced energy-efficiency features in laboratory-type environments. The Guide fills an important void in the general literature and compliments existing in-depth technical manuals. Considerable information is available pertaining to overall laboratory design issues, but no single document focuses comprehensively on energy issues in these highly specialized environments. Furthermore, practitioners may utilize many antiquated rules of thumb, which often inadvertently cause energy inefficiency. The Guide helps its user to: introduce energy decision-making into the earliest phases of the design process, access the literature of pertinent issues, and become aware of debates and issues on related topics. The Guide does focus on individual technologies, as well as control systems, and important operational factors such as building commissioning. However, most importantly, the Guide is intended to foster a systems perspective (e.g. right sizing) and to present current leading-edge, energy-efficient design practices and principles.

  10. Building America Best Practices Series Volume 11. Builders Challenge Guide to 40% Whole-House Energy Savings in the Marine Climate

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Michael C.; Gilbride, Theresa L.; Hefty, Marye G.; Cole, Pamala C.; Williamson, Jennifer L.; Love, Pat M.

    2010-09-01

    This best practices guide is the eleventh in a series of guides for builders produced by the U.S. Department of Energy’s Building America Program. This guide book is a resource to help builders design and construct homes that are among the most energy-efficient available, while addressing issues such as building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the marine climate (portions of Washington, Oregon, and California) can achieve homes that have whole house energy savings of 40% over the Building America benchmark (a home built to mid-1990s building practices roughly equivalent to the 1993 Model Energy Code) with no added overall costs for consumers. These best practices are based on the results of research and demonstration projects conducted by Building America’s research teams. The guide includes information for managers, designers, marketers, site supervisors, and subcontractors, as well as case studies of builders who are successfully building homes that cut energy use by 40% in the marine climate. This document is available on the web at www.buildingamerica.gov. This report was originally cleared 06-29-2010. This version is Rev 1 cleared in Nov 2010. The only change is the reference to the Energy Star Windows critieria shown on pg 8.25 was updated to match the criteria - Version 5.0, 04/07/2009, effective 01/04/2010.

  11. High energy radiation from neutron stars

    International Nuclear Information System (INIS)

    Ruderman, M.

    1985-04-01

    Topics covered include young rapidly spinning pulsars; static gaps in outer magnetospheres; dynamic gaps in pulsar outer magnetospheres; pulse structure of energetic radiation sustained by outer gap pair production; outer gap radiation, Crab pulsar; outer gap radiation, the Vela pulsar; radioemission; and high energy radiation during the accretion spin-up of older neutron stars. 26 refs., 10 figs

  12. Calendar Year 2007 Program Benefits for U.S. EPA Energy Star Labeled Products: Expanded Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marla; Homan, Gregory; Lai, Judy; Brown, Richard

    2009-09-24

    This report provides a top-level summary of national savings achieved by the Energy Star voluntary product labeling program. To best quantify and analyze savings for all products, we developed a bottom-up product-based model. Each Energy Star product type is characterized by product-specific inputs that result in a product savings estimate. Our results show that through 2007, U.S. EPA Energy Star labeled products saved 5.5 Quads of primary energy and avoided 100 MtC of emissions. Although Energy Star-labeled products encompass over forty product types, only five of those product types accounted for 65percent of all Energy Star carbon reductions achieved to date, including (listed in order of savings magnitude)monitors, printers, residential light fixtures, televisions, and furnaces. The forecast shows that U.S. EPA?s program is expected to save 12.2 Quads of primary energy and avoid 215 MtC of emissions over the period of 2008?2015.

  13. Savings estimates for the ENERGY STAR (registered trademark) voluntary labeling program: 2001 status report; TOPICAL

    International Nuclear Information System (INIS)

    Webber, Carrie A.; Brown, Richard E.; Mahajan, Akshay; Koomey, Jonathan G.

    2002-01-01

    ENERGY STAR(Registered Trademark) is a voluntary labeling program designed to identify and promote energy-efficient products, buildings and practices. Operated jointly by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), ENERGY STAR labels exist for more than thirty products, spanning office equipment, residential heating and cooling equipment, commercial and residential lighting, home electronics, and major appliances. This report presents savings estimates for a subset of ENERGY STAR program activities, focused primarily on labeled products. We present estimates of the energy, dollar and carbon savings achieved by the program in the year 2000, what we expect in 2001, and provide savings forecasts for two market penetration scenarios for the period 2001 to 2020. The target market penetration forecast represents our best estimate of future ENERGY STAR savings. It is based on realistic market penetration goals for each of the products. We also provide a forecast under the assumption of 100 percent market penetration; that is, we assume that all purchasers buy ENERGY STAR-compliant products instead of standard efficiency products throughout the analysis period

  14. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Harrison, Fiona A.; Craig, William W.; Christensen, Finn Erland

    2013-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X...

  15. ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/

  16. High-energy X-ray production in a boundary layer of an accreting neutron star

    International Nuclear Information System (INIS)

    Hanawa, Tomoyuki

    1991-01-01

    It is shown by Monte Carlo simulation that high-energy X-rays are produced through Compton scattering in a boundary layer of an accreting neutron star. The following is the mechanism for the high-energy X-ray production. An accreting neutron star has a boundary layer rotating rapidly on the surface. X-rays radiated from the star's surface are scattered in part in the boundary layer. Since the boundary layer rotates at a semirelativistic speed, the scattered X-ray energy is changed by the Compton effect. Some X-rays are scattered repeatedly between the neutron star and the boundary layer and become high-energy X-rays. This mechanism is a photon analog of the second-order Fermi acceleration of cosmic rays. When the boundary layer is semitransparent, high-energy X-rays are produced efficiently. 17 refs

  17. ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner...

  18. Shedding Light on the EOS-Gravity Degeneracy and Constraining the Nuclear Symmetry Energy from the Gravitational Binding Energy of Neutron Stars

    Directory of Open Access Journals (Sweden)

    He Xiao-Tao

    2016-01-01

    Full Text Available A thorough understanding of properties of neutron stars requires both a reliable knowledge of the equation of state (EOS of super-dense nuclear matter and the strong-field gravity theories simultaneously. To provide information that may help break this EOS-gravity degeneracy, we investigate effects of nuclear symmetry energy on the gravitational binding energy of neutron stars within GR and the scalar-tensor subset of alternative gravity models. We focus on effects of the slope L of nuclear symmetry energy at saturation density and the high-density behavior of nuclear symmetry energy. We find that the variation of either the density slope L or the high-density behavior of nuclear symmetry energy leads to large changes in the binding energy of neutron stars. The difference in predictions using the GR and the scalar-tensor theory appears only for massive neutron stars, and even then is significantly smaller than the difference resulting from variations in the symmetry energy.

  19. America's Star Libraries

    Science.gov (United States)

    Lyons, Ray; Lance, Keith Curry

    2009-01-01

    "Library Journal"'s new national rating of public libraries, the "LJ" Index of Public Library Service, identifies 256 "star" libraries. It rates 7,115 public libraries. The top libraries in each group get five, four, or three Michelin guide-like stars. All included libraries, stars or not, can use their scores to learn from their peers and improve…

  20. How to Launch an Energy Star Energy Efficiency Competition for K-12 Schools

    Science.gov (United States)

    Utebay Kudret; McArthur, Ashley

    2012-01-01

    In recent years, schools have been forced by rising costs and shrinking budgets to stretch their resources further than ever before in order to meet the educational needs of today's students. EPA's ENERGY STAR program helps K-12 schools and districts improve energy efficiency, reduce operating costs and redirect critical resources into the…

  1. Finding a million-star hotel an astro-tourist’s guide to dark sky places

    CERN Document Server

    Mizon, Bob

    2016-01-01

    Finding a Million-Star Hotel explores the modern phenomenon of astro-tourism, the efforts by increasing numbers of people to find nearby and distant locations where they can see the real night sky so often hidden by light pollution. Astronomer Bob Mizon directs readers to dark sky sites in the United Kingdom, the United States, and a few further afield. This is more than just a hotel guide with links for accommodation at or near the locations. There are chapters on choosing telescopes and binoculars, on celestial objects astro-tourists can look for in the night sky, and an investigation into the causes of the skyglow that veils our view of the stars. Most of those who go seeking the stars are not professional astronomers. This book is aimed at those observers with limited knowledge of the night sky who are eager to explore and enjoy it. Even those contemplating setting up astro-themed hotels, campsites, or astronomy events can benefit from reading this book and from the advice included on how to equip such pl...

  2. Energy spectrum of flares of the UV Cet stars and physical measunings of several statistical characteristics of these stars

    International Nuclear Information System (INIS)

    Gershberg, R.E.

    1985-01-01

    Accounting the observed power character of the energy spectrum of flares of the UV Cet-type stars, several statistical characterisitics of there stars are considered. It is shown that a mean amplitude of flares is mainly determined with an amplitude of the faintest flare that can be registered at the star under consideration and therefore - contrary to tradition - the mean flare amplitude cannot be used as a measure of a flare activity of the star. Mean frequencuy of flares registered at a flare star dependes statisticaally certainly ona an absolute magneitude of the star - contary to wide spread belief, true mean frequencies are higher at brighter stars. On the basis of the Cataloque of flare stars in Pleiades by Haro, Chavira and Gonzalez a luminosity function of therese stars is constructed. Using this function and the revealed dependence of flare mean frequencies on stellar absolute magnitudes, a distribution of flare stars in Pleiades along flare mean frequencies is constructed. This shows that the cluster contains flare stars with mean frequencies of photographically registered flares from 10 -4 to 10 -2 hour -1 or within even narrower interval of frequencies and the total number of such stars in the cluster exceeds 1100

  3. Observer’s guide to star clusters

    CERN Document Server

    Inglis, Mike

    2013-01-01

    This book is for amateur astronomers of all expertise, from beginner to experienced. It is intended to be used at the telescope – small, medium, or large – or even by an observer using binoculars or the naked eye. It is organized by constellation and will enable practical observers to locate the approximate positions of important star clusters in the 88 constellations from literally anywhere on Earth.  In practice, GO-TO telescopes can usually locate clusters accurately enough, but this, of course, first requires that the observer knows what is visible in the sky at a given time and from a given location, so as to input a locatable object! This is where the book becomes an essential aid to finding star clusters to observe. Observers who do not have computer-controlled telescopes can of course use the traditional “star-hopping” method to find specific objects, starting from the given reference stars.  The constellation maps in this book are in black and white, so that they can be read by the light of...

  4. Wavefront error budget development for the Thirty Meter Telescope laser guide star adaptive optics system

    Science.gov (United States)

    Gilles, Luc; Wang, Lianqi; Ellerbroek, Brent

    2008-07-01

    This paper describes the modeling effort undertaken to derive the wavefront error (WFE) budget for the Narrow Field Infrared Adaptive Optics System (NFIRAOS), which is the facility, laser guide star (LGS), dual-conjugate adaptive optics (AO) system for the Thirty Meter Telescope (TMT). The budget describes the expected performance of NFIRAOS at zenith, and has been decomposed into (i) first-order turbulence compensation terms (120 nm on-axis), (ii) opto-mechanical implementation errors (84 nm), (iii) AO component errors and higher-order effects (74 nm) and (iv) tip/tilt (TT) wavefront errors at 50% sky coverage at the galactic pole (61 nm) with natural guide star (NGS) tip/tilt/focus/astigmatism (TTFA) sensing in J band. A contingency of about 66 nm now exists to meet the observatory requirement document (ORD) total on-axis wavefront error of 187 nm, mainly on account of reduced TT errors due to updated windshake modeling and a low read-noise NGS wavefront sensor (WFS) detector. A detailed breakdown of each of these top-level terms is presented, together with a discussion on its evaluation using a mix of high-order zonal and low-order modal Monte Carlo simulations.

  5. Supersoft Symmetry Energy Encountering Non-Newtonian Gravity in Neutron Stars

    International Nuclear Information System (INIS)

    Wen Dehua; Li Baoan; Chen Liewen

    2009-01-01

    Considering the non-Newtonian gravity proposed in grand unification theories, we show that the stability and observed global properties of neutron stars cannot rule out the supersoft nuclear symmetry energies at suprasaturation densities. The degree of possible violation of the inverse-square law of gravity in neutron stars is estimated using an equation of state of neutron-rich nuclear matter consistent with the available terrestrial laboratory data.

  6. Symmetry Energy Effects in the Neutron Star Properties

    Science.gov (United States)

    Alvarez-Castillo, D. E.; Kubis, S.

    2012-12-01

    The functional form of the nuclear symmetry energy has only been determined in a very narrow range of densities. Uncertainties concern both the low as well as the high density behaviour of this function. In this work different shapes of the symmetry energy, consistent with the experimental data, were introduced and their consequences for the crustal properties of neutron stars are presented. The resulting models are in agreement with astrophysical observations.

  7. Guide to Operating and Maintaining EnergySmart Schools

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-01-01

    Through a commitment to high performance, school districts are discovering that smart energy choices can create lasting benefits for students, communities, and the environment. For example, an energy efficient school district with 4,000 students can save as much as $160,000 a year in energy costs. Over 10 years, those savings can reach $1.6 million, translating into the ability to hire more teachers, purchase more textbooks and computers, or invest in additional high performance facilities. Beyond these bottomline benefits, schools can better foster student health, decrease absenteeism, and serve as centers of community life. The U.S. Department of Energy's EnergySmart Schools Program promotes a 30 percent improvement in existing school energy use. It also encourages the building of new schools that exceed code (ASHRAE 90.11999) by 50 percent or more. The program provides resources like this Guide to Operating and Maintaining EnergySmart Schools to assist school decisionmakers in planning, financing, operating, and maintaining energy efficient, high performance schools. It also offers education and training for building industry professionals. Operations and maintenance refer to all scheduled and unscheduled actions for preventing equipment failure or decline with the goal of increasing efficiency, reliability, and safety. A preventative maintenance program is the organized and planned performance of maintenance activities in order to prevent system or production problems or failures from occurring. In contrast, deferred maintenance or reactive maintenance (also called diagnostic or corrective maintenance) is conducted to address an existing problem. This guide is a primary resource for developing and implementing a districtor schoolwide operations and maintenance (O&M) program that focuses on energy efficiency. The EnergySmart Schools Solutions companion CD contains additional supporting information for design, renovation, and retrofit projects. The objective

  8. 77 FR 66976 - Star Energy Partners LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2012-11-08

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. ER13-281-000] Star Energy Partners LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Star Energy...

  9. Laser guide stars for optical free-space communications

    Science.gov (United States)

    Mata-Calvo, Ramon; Bonaccini Calia, Domenico; Barrios, Ricardo; Centrone, Mauro; Giggenbach, Dirk; Lombardi, Gianluca; Becker, Peter; Zayer, Igor

    2017-02-01

    The German Aerospace Center (DLR) and the European Southern Observatory (ESO) performed a measurement campaign together in April and July 2016 at Teide-Observatory (Tenerife), with the support of the European Space Agency (ESA), to investigate the use of laser guide stars (LGS) in ground to space optical communications. Atmospheric turbulence causes strong signal fluctuations in the uplink, due to scintillation and beam wander. In space communications, the use of the downlink channel as reference for pointing and for pre-distortion adaptive optics is limited by the size of the isokinetic and isoplanatic angle in relation to the required point-ahead angle. Pointing and phase errors due to the decorrelation between downward and upward beam due to the point-ahead angle may have a severe impact on the required transmit power and the stability of the communications link. LGSs provide a self-tailored reference to any optical ground-to-space link, independently of turbulence conditions and required point-ahead angle. In photon-starved links, typically in deep-space scenarios, LGSs allow dedicating all downlink received signal to communications purposes, increasing the available link margin. The scope of the joint DLR-ESO measurement campaign was, first, to measure the absolute value of the beam wander (uplink-tilt) using a LGS, taking a natural star as a reference, and, second, to characterize the decrease of correlation between uplink-tilt and downlink-tilt with respect to the angular separation between both sources. This paper describes the experiments performed during the measurement campaigns, providing an overview of the measured data and the first outcomes of the data post-processing.

  10. Advanced Energy Retrofit Guide (AERG): Practical Ways to Improve Energy Performance; Healthcare Facilities (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, R.; Leach, M.; Bonnema, E.; Shekhar, D.; Pless, S.

    2013-09-01

    The Advanced Energy Retrofit Guide for Healthcare Facilities is part of a series of retrofit guides commissioned by the U.S. Department of Energy. By presenting general project planning guidance as well as detailed descriptions and financial payback metrics for the most important and relevant energy efficiency measures (EEMs), the guides provide a practical roadmap for effectively planning and implementing performance improvements in existing buildings. The Advanced Energy Retrofit Guides (AERGs) are intended to address key segments of the U.S. commercial building stock: retail stores, office buildings, K-12 schools, grocery stores, and healthcare facilities. The guides' general project planning considerations are applicable nationwide; the energy and cost savings estimates for recommended EEMs were developed based on energy simulations and cost estimates for an example hospital tailored to five distinct climate regions. These results can be extrapolated to other U.S. climate zones. Analysis is presented for individual EEMs, and for packages of recommended EEMs for two project types: existing building commissioning projects that apply low-cost and no-cost measures, and whole-building retrofits involving more capital-intensive measures.

  11. Energy flux determines magnetic field strength of planets and stars.

    Science.gov (United States)

    Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar

    2009-01-08

    The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.

  12. Manual on high energy teletherapy. Incorporating: Applications guide, procedures guide, basics guide

    International Nuclear Information System (INIS)

    1992-01-01

    Apart from a basic guide to the principles of the production of ionizing radiation and to methods of radiation protection and dose measurements, this booklet contains information about radiation protection measures for high-energy teletherapy

  13. A tip / tilt mirror with large dynamic range for the ESO VLT Four Laser Guide Star Facility

    NARCIS (Netherlands)

    Rijnveld, N.; Henselmans, R.; Nijland, B.A.H.

    2011-01-01

    One of the critical elements in the Four Laser Guide Star Facility (4LGSF) for the ESO Very Large Telescope (VLT) is the Optical Tube Assembly (OTA), consisting of a stable 20x laser beam expander and an active tip/tilt mirror, the Field Selector Mechanism (FSM). This paper describes the design and

  14. The Vixen Star Book user guide how to use the star book ten and the original star book

    CERN Document Server

    Chen, James

    2016-01-01

    This book is for anyone who owns, or is thinking of owning, a Vixen Star Book Ten telescope mount or its predecessor. A revolution in amateur astronomy has occurred in the past decade with the wide availability of high tech, computer-driven, Go-To telescopes. Vixen Optics is leading the way by offering the Star Book Ten system, with its unique star map graphics software. The Star Book Ten is the latest version of computer telescope control using star map graphics as a user interface, first introduced in the original Star Book first offered in 2003. The increasingly complicated nature of this software means that learning to optimize this program is not straightforward, and yet the resulting views when all features are correctly deployed can be phenomenal. After a short history of computerized Go-To telescopes for the consumer amateur astronomer market, Chen offers a treasury of technical information. His advice, tips, and solutions aid the user in getting the most out of the Star Book Ten system in observing s...

  15. 78 FR 4467 - UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3...

    Science.gov (United States)

    2013-01-22

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC and UniStar Nuclear Operating Services...

  16. Solar energy guide

    International Nuclear Information System (INIS)

    Lentz, A.; Winter, R.

    1993-07-01

    Many aspects with regard to the practical use of solar energy are discussed. This guide is aimed at informing local and regional administrators, committee members of housing corporations and public utilities and public relations officers on the possibilities to use solar energy. In chapter one an overview is given of the use of solar energy in the housing sector, the recreational sector, agricultural sector, industry, trade and other sectors. In the chapters two, three and four attention is paid to passive solar energy, active thermal solar energy and photovoltaic energy respectively. In the chapters five and six aspects concerning the implementation of solar energy systems in practice are discussed. First an outline of the parties involved in implementing solar energy is given: the municipality, the energy utility, the province, local authorities, advisors, housing constructors and the occupants of the buildings. Then attention is paid to the consequences of implementing solar energy for the building inspection and regulations, the finances, energy savings and the environment. In chapter seven an overview is given of the subsidy regulations of the European Community, the Dutch national and local governments. Chapter contains addresses of solar thermal systems, photovoltaic systems and other institutes operating in the field of solar energy, as well as the titles of a number of brochures and courses. 51 figs., 7 tabs., 86 refs

  17. Capabilities of a Laser Guide Star for a Large Segmented Space Telescope

    Science.gov (United States)

    Clark, James R.; Carlton, Ashley; Douglas, Ewan S.; Males, Jared R.; Lumbres, Jennifer; Feinberg, Lee; Guyon, Olivier; Marlow, Weston; Cahoy, Kerri L.

    2018-01-01

    Large segmented mirror telescopes are planned for future space telescope missions such as LUVOIR (Large UV Optical Infrared Surveyor) to enable the improvement in resolution and contrast necessary to directly image Earth-like exoplanets, in addition to making contributions to general astrophysics. The precision surface control of these complex, large optical systems, which may have over a hundred meter-sized segments, is a challenge. Our initial simulations show that imaging a star of 2nd magnitude or brighter with a Zernike wavefront sensor should relax the segment stability requirements by factors between 10 and 50 depending on the wavefront control strategy. Fewer than fifty stars brighter than magnitude 2 can be found in the sky. A laser guide star (LGS) on a companion spacecraft will allow the telescope to target a dimmer science star and achieve wavefront control to the required stability without requiring slew or repointing maneuvers.We present initial results for one possible mission architecture, with a LGS flying at 100,000 km range from the large telescope in an L2 halo orbit, using a laser transmit power of 8 days) for an expenditure of system, it can be accommodated in a 6U CubeSat bus, but may require an extended period of time to transition between targets and match velocities with the telescope (e.g. 6 days to transit 10 degrees). If the LGS uses monopropellant propulsion, it must use at least a 27U bus to achieve the the same delta-V capability, but can transition between targets much more rapidly (flight are being refined. A low-cost prototype mission (e.g. between a small satellite in LEO and an LGS in GEO) to validate the feasibility is in development.

  18. Energy emergency planning guide: Winter 1977-78

    Energy Technology Data Exchange (ETDEWEB)

    1977-11-01

    This Energy Emergency Planning Guide for Winter, 1977-78 has been prepared in order to: identify and evaluate actions available to deal with energy emergencies this winter; provide an advance indication to the public of those actions considered most likely to be taken by the government, and provide industry, state, and local governments with suggestions about actions which they can take to deal with energy emergencies. The Guide contains specifications for over 50 standby programs and procedures, recommended implementation guidelines for using these programs keyed to a pre-emergency phase and three phases of shortfalls, and a design for an Energy Emergency Center. Flexible implementation guidelines are proposed for natural gas, petroleum, electricity/coal, and propane shortages. (MCW)

  19. Spectrophotometry of Wolf-Rayet stars. I - Continuum energy distributions

    Science.gov (United States)

    Morris, Patrick W.; Brownsberger, Kenneth R.; Conti, Peter S.; Massey, Philip; Vacca, William D.

    1993-01-01

    All available low-resolution IUE spectra are assembled for Galactic, LMC, and SMC W-R stars and are merged with ground-based optical and NIR spectra in order to collate in a systematic fashion the shapes of these energy distributions over the wavelength range 0.1-1 micron. They can be consistently fitted by a power law of the form F(lambda) is approximately equal to lambda exp -alpha over the range 1500-9000 A to derive color excesses E(B-V) and spectral indices by removing the 2175-A interstellar absorption feature. The WN star color excesses derived are found to be in good agreement with those of Schmutz and Vacca (1991) and Koesterke et al. (1991). Significant heterogeneity in spectral index values was generally seen with any given subtype, but the groups consisting of the combined set of Galactic and LMC W-R stars, the separate WN and WC sequences, and the Galactic and LMC W-R stars all showed a striking and consistent Gaussian-like frequency distribution of values.

  20. Danish Sector Guide for Calculation of the Actual Energy Consumption

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard

    2016-01-01

    , the innovation network for sustainable construction, InnoBYG started work on a Danish sector guide for the calculation of actual energy consumption in relation to upgrading of buildings. The focus was to make a common guide for energy calculations that can be used by consultants performing calculations...... consumption compared with the estimated energy demand by calculation. The paper concludes that the result of an energy calculation should not be given as a single figure but rather as a spread between the best and worst case for the assumed conditions. Finally, a brief update on current actions is given...... related to the sector guide for calculation of actual energy consumption. Keywords – Energy calculations, actual energy consumption, energy perfomance...

  1. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Harrison, Fiona A.; Hongjun An

    2014-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers...

  2. Saving Energy. Managing School Facilities, Guide 3.

    Science.gov (United States)

    Department for Education and Employment, London (England). Architects and Building Branch.

    This guide offers information on how schools can implement an energy saving action plan to reduce their energy costs. Various low-cost energy-saving measures are recommended covering heating levels and heating systems, electricity demand reduction and lighting, ventilation, hot water usage, and swimming pool energy management. Additional…

  3. Guide to energy management; Veiledning for energiledelse

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-03-15

    A systematic and practical guide to energy management. Energy management signifies here a methodology concerning how an organisation continuously can work on improving all aspects of energy efficiency and energy consumption. Focus is on how energy management can be implemented in the companies already existing environment management systems. Useful recommendations and examples are provided (ml)

  4. Energy activity guide : simple steps to reduce your household energy use

    Energy Technology Data Exchange (ETDEWEB)

    Byckalo-Khan, F; Wallace, C L [ed.

    2003-07-01

    This guide presents 13 practical activities that can help households reduce energy consumption in order to create a more sustainable lifestyle and to help meet Canada's Kyoto commitment to reduce greenhouse gas emissions. Most energy sources create pollution that harms both human health and the Earth. The burning of fossil fuels creates greenhouse gas emissions that contribute to climate change, smog, pollution and adverse health effects. This guide offers suggestions on how households can reduce the impact on the environment while saving money. Some of the initiatives include lowering the thermostat, replacing incandescent light bulbs with compact fluorescent light bulbs, turning off appliances when not in use, weatherising building envelopes, using a clothes line to dry clothes instead of a dryer, laundering clothes with cold water, and proper maintenance of heating equipment. An energy use chart is included with this guide to help track activities and to estimate how much time and money is required by each activity. refs., figs.

  5. Energy activity guide : simple steps to reduce your household energy use

    Energy Technology Data Exchange (ETDEWEB)

    Byckalo-Khan, F.; Wallace, C.L. (ed.)

    2003-07-01

    This guide presents 13 practical activities that can help households reduce energy consumption in order to create a more sustainable lifestyle and to help meet Canada's Kyoto commitment to reduce greenhouse gas emissions. Most energy sources create pollution that harms both human health and the Earth. The burning of fossil fuels creates greenhouse gas emissions that contribute to climate change, smog, pollution and adverse health effects. This guide offers suggestions on how households can reduce the impact on the environment while saving money. Some of the initiatives include lowering the thermostat, replacing incandescent light bulbs with compact fluorescent light bulbs, turning off appliances when not in use, weatherising building envelopes, using a clothes line to dry clothes instead of a dryer, laundering clothes with cold water, and proper maintenance of heating equipment. An energy use chart is included with this guide to help track activities and to estimate how much time and money is required by each activity. refs., figs.

  6. Design of pre-optics for laser guide star wavefront sensor for the ELT

    Science.gov (United States)

    Muslimov, Eduard; Dohlen, Kjetil; Neichel, Benoit; Hugot, Emmanuel

    2017-12-01

    In the present paper, we consider the optical design of a zoom system for the active refocusing in laser guide star wavefront sensors. The system is designed according to the specifications coming from the Extremely Large Telescope (ELT)-HARMONI instrument, the first-light, integral field spectrograph for the European (E)-ELT. The system must provide a refocusing of the laser guide as a function of telescope pointing and large decentring of the incoming beam. The system considers four moving lens groups, each of them being a doublet with one aspherical surface. The advantages and shortcomings of such a solution in terms of the component displacements and complexity of the surfaces are described in detail. It is shown that the system can provide the median value of the residual wavefront error of 13.8-94.3 nm and the maximum value <206 nm, while the exit pupil distortion is 0.26-0.36% for each of the telescope pointing directions.

  7. Nuclear Statistical Equilibrium for compact stars: modelling the nuclear energy functional

    International Nuclear Information System (INIS)

    Aymard, Francois

    2015-01-01

    The core collapse supernova is one of the most powerful known phenomena in the universe. It results from the explosion of very massive stars after they have burnt all their fuel. The hot compact remnant, the so-called proto-neutron star, cools down to become an inert catalyzed neutron star. The dynamics and structure of compact stars, that is core collapse supernovae, proto-neutron stars and neutron stars, are still not fully understood and are currently under active research, in association with astrophysical observations and nuclear experiments. One of the key components for modelling compact stars concerns the Equation of State. The task of computing a complete realistic consistent Equation of State for all such stars is challenging because a wide range of densities, proton fractions and temperatures is spanned. This thesis deals with the microscopic modelling of the structure and internal composition of baryonic matter with nucleonic degrees of freedom in compact stars, in order to obtain a realistic unified Equation of State. In particular, we are interested in a formalism which can be applied both at sub-saturation and super-saturation densities, and which gives in the zero temperature limit results compatible with the microscopic Hartree-Fock-Bogoliubov theory with modern realistic effective interactions constrained on experimental nuclear data. For this purpose, we present, for sub-saturated matter, a Nuclear Statistical Equilibrium model which corresponds to a statistical superposition of finite configurations, the so-called Wigner-Seitz cells. Each cell contains a nucleus, or cluster, embedded in a homogeneous electron gas as well as a homogeneous neutron and proton gas. Within each cell, we investigate the different components of the nuclear energy of clusters in interaction with gases. The use of the nuclear mean-field theory for the description of both the clusters and the nucleon gas allows a theoretical consistency with the treatment at saturation

  8. Managing Your Energy; An Energy Star Guide for Identifying Energy Savings in Manufacturing Plants

    NARCIS (Netherlands)

    Worrell, E.; Angelini, T.; Masanet, E.

    2010-01-01

    In the United States, industry spends over $100 billion annually to power its manufacturing plants. Companies also spend on maintenance, capital outlay, and energy services. Improving energy efficiency is vital to reduce these costs and increase earnings. Many cost-effective opportunities to reduce

  9. 50% Advanced Energy Design Guides: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, E.; Leach, M.; Pless, S.; Liu, B.; Wang, W.; Thornton, B.; Williams, J.

    2012-07-01

    This paper presents the process, methodology, and assumptions for the development of the 50% Energy Savings Advanced Energy Design Guides (AEDGs), a design guidance document that provides specific recommendations for achieving 50% energy savings above the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004 in four building types: (1) Small to medium office buildings, (2) K-12 school buildings, (3) Medium to big box retail buildings, (4) Large hospital buildings.

  10. Imprint of the symmetry energy on the inner crust and strangeness content of neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Providencia, Constanca; Chiacchiera, Silvia; Grill, Fabrizio; Rabhi, Aziz; Vidana, Isaac [University of Coimbra, Centro de Fisica Computacional, Department of Physics, Coimbra (Portugal); Avancini, Sidney S.; Menezes, Debora P. [Universidade Federal de Santa Catarina, Departamento de Fisica, SC - CP. 476, Florianopolis (Brazil); Cavagnoli, Rafael [Universidade Federal de Pelotas, Departamento de Fisica, CP 354, Pelotas/SC (Brazil); Ducoin, Camille; Margueron, Jerome [Universite Claude Bernard Lyon 1, Institut de Physique Nucleaire de Lyon, Villeurbanne (France)

    2014-02-15

    In this work we study the effect of the symmetry energy on several properties of neutron stars. First, we discuss its effect on the density, proton fraction and pressure of the neutron star crust-core transition. We show that whereas the first two quantities present a clear correlation with the slope parameter L of the symmetry energy, no satisfactory correlation is seen between the transition pressure and L. However, a linear combination of the slope and curvature parameters at ρ = 0.1 fm{sup -3} is well correlated with the transition pressure. In the second part we analyze the effect of the symmetry energy on the pasta phase. It is shown that the size of the pasta clusters, number of nucleons and the cluster proton fraction depend on the density dependence of the symmetry energy: a small L gives rise to larger clusters. The influence of the equation of state at subsaturation densities on the extension of the inner crust of the neutron star is also discussed. Finally, the effect of the density dependence of the symmetry energy on the strangeness content of neutron stars is studied in the last part of the work. It is found that charged (neutral) hyperons appear at smaller (larger) densities for smaller values of the slope parameter L. A linear correlation between the radius and the strangeness content of a star with a fixed mass is also found. (orig.)

  11. Symmetry energy, unstable nuclei and neutron star crusts

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Kei [Kochi University, Department of Natural Science, Kochi (Japan); RIKEN Nishina Center, Saitama (Japan); Oyamatsu, Kazuhiro [RIKEN Nishina Center, Saitama (Japan); Aichi Shukutoku University, Department of Human Informatics, Aichi (Japan)

    2014-02-15

    The phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crusts including nuclear pasta. We finally discuss the possibility of constraining the density dependence of the symmetry energy from experiments on unstable nuclei and even observations of quasi-periodic oscillations in giant flares of soft gamma-ray repeaters. (orig.)

  12. Neutron stars as probes of extreme energy density matter

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... Neutron stars have long been regarded as extraterrestrial laboratories from which we can learn about extreme energy density matter at low temperatures. In this article, some of the recent advances made in astrophysical observations and related theory are highlighted. Although the focus is on the much ...

  13. Smart Metering Guide. Energy Saving and the Customer. Edition 2010

    Energy Technology Data Exchange (ETDEWEB)

    Kester, J.C.P. (ed.) [Energy research Centre of the Netherlands ECN, Petten (Netherlands); Gonzalez Burgos, M.J. (ed.) [Endesa Ingenieria, Madrid (Spain); Parsons, J. (ed.) [British Electrotechnical and Allied Manufacturers Association BEAMA, London (United Kingdom)

    2010-11-15

    Smart metering can provide the foundations for a radically different approach to energy reduction schemes. However, the implementation of smart metering is a complex undertaking and its success depends on getting many factors right, from technology choice to how the information is presented to final customers. Making the expected reduction in energy consumption depends on achieving a positive reaction from final customers. Maintaining and increasing these savings will need the engagement of Energy Retailers, energy agencies and others. This Guide has been produced to bring together the lessons learnt from smart metering systems and trials, targeted on the promotion of End Use Energy Efficiency. The aim is to assist those groups who are considering implementing smart metering for this purpose and to maximise the benefits arising from those implementations. . The main target audience for the Guide are utilities, ESCO's and service providers across Europe. In most countries these are the parties investing in the smart metering systems and providing the smart metering services. In addition to these, governments, regulators, consumer bodies and energy agencies, as well as suppliers and system integrators, will also find valuable information in the Guide. As the subtitle of the Guide indicates, the focus of this Guide is on the application of smart metering for delivering energy saving. Making the expected reduction in energy consumption depends on achieving a positive reaction from final customers. In general, the successful provision of smart metering services is highly dependent on the right involvement of the energy final customer. This guide is not a ready-to-go manual for the installation of a specific type of smart metering system. Rather, the authors have tried to give the reader an insight into some of the complexities of the whole implementation process of smart metering systems. Also the guide is impartial regarding different technologies unless there is

  14. EMACSS: Evolve Me A Cluster of StarS

    Science.gov (United States)

    Alexander, Poul E. R.; Gieles, Mark

    2012-03-01

    The star cluster evolution code Evolve Me A Cluster of StarS (EMACSS) is a simple yet physically motivated computational model that describes the evolution of some fundamental properties of star clusters in static tidal fields. The prescription is based upon the flow of energy within the cluster, which is a constant fraction of the total energy per half-mass relaxation time. According to Henon's predictions, this flow is independent of the precise mechanisms for energy production within the core, and therefore does not require a complete description of the many-body interactions therein. Dynamical theory and analytic descriptions of escape mechanisms is used to construct a series of coupled differential equations expressing the time evolution of cluster mass and radius for a cluster of equal-mass stars. These equations are numerically solved using a fourth-order Runge-Kutta integration kernel; the results were benchmarked against a data base of direct N-body simulations. EMACSS is publicly available and reproduces the N-body results to within 10 per cent accuracy for the entire post-collapse evolution of star clusters.

  15. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance; Grocery Stores (Revised) (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, B.

    2013-07-01

    The U.S. Department of Energy developed the Advanced Energy Retrofit Guides (AERGs) to provide specific methodologies, information, and guidance to help energy managers and other stakeholders successfully plan and execute energy efficiency improvements. Detailed technical discussion is fairly limited in these guides. Instead, we emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluations of the most promising retrofit measures for each building type. A series of AERGs is under development, addressing key segments of the commercial building stock. Grocery stores were selected as one of the highest priority sectors, because they represent one of the most energy-intensive market segments.

  16. The guide to sustainable energy technologies for schools; Un guide pour les technologies energetiques durables dans les ecoles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    There are significant attractions for municipalities to opt for sustainable solutions which involve energy efficient technologies and measures. This is the challenging background which led to the production the Guide to Sustainable Energy Technologies for Schools. This guide is a decision-making tool intended for European municipalities and school managers. Its aim is to: assist them in choosing between the energy technologies that will be used in school building or retrofitting projects and provide them with a framework for measuring and comparing different aspects of energy performance that can be used to convince decision-makers to select sustainable energy technologies and measures. The guide is composed of three parts: an illustrative list of sustainable energy technologies, an introduction to energy performance indicators and fifteen case studies describing practical sustainable energy solutions applied to schools in seven European countries. (A.L.B.)

  17. Research of low-carbon transition path of star hotels--A case study of Guilin

    Directory of Open Access Journals (Sweden)

    Tang Fengling

    2016-01-01

    Full Text Available A general trend of the world economic development is the low-carbon economic transition. With a wide influencing range and rapid development, the hotel industry has prominent problems in the energy con-sumption, resources occupancy and environmental unfriendliness, so it is imperative to develop low-carbon ho-tels. This paper proposes the low-carbon transition of the star hotels in Guilin in terms of constructing the energy conservation and innovative management mode, adopting new technologies and ways, developing low-carbon hotel products and guiding low-carbon consumption through analysis about the inevitability of establishing low-carbon hotels in Guilin, the running status of the existing star hotels and the situation of energy consumption, thus further promoting the development of low-carbon tourism in Guilin.

  18. Modeling update for the Thirty Meter Telescope laser guide star dual-conjugate adaptive optics system

    Science.gov (United States)

    Gilles, Luc; Wang, Lianqi; Ellerbroek, Brent

    2010-07-01

    This paper describes the modeling efforts undertaken in the past couple of years to derive wavefront error (WFE) performance estimates for the Narrow Field Infrared Adaptive Optics System (NFIRAOS), which is the facility laser guide star (LGS) dual-conjugate adaptive optics (AO) system for the Thirty Meter Telescope (TMT). The estimates describe the expected performance of NFIRAOS as a function of seeing on Mauna Kea, zenith angle, and galactic latitude (GL). They have been developed through a combination of integrated AO simulations, side analyses, allocations, lab and lidar experiments.

  19. 76 FR 81994 - UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit...

    Science.gov (United States)

    2011-12-29

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear Regulatory Commission (NRC or the Commission ) a...

  20. Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars

    International Nuclear Information System (INIS)

    Li Baoan; Chen Liewen; Gearheart, Michael; Hooker, Joshua; Krastev, Plamen G; Lin Weikang; Newton, William G; Wen Dehua; Xu Chang; Ko Cheming; Xu Jun

    2011-01-01

    Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclear matter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the ω-mode frequency and damping time of gravitational wave emission of neutron stars.

  1. U.S. Department of Energy Solar Decathlon Visitors Guide 2015

    Energy Technology Data Exchange (ETDEWEB)

    2015-09-03

    The U.S. Department of Energy 2015 Visitors Guide is a free, hard-copy publication distributed free to those attending the Solar Decathlon event. The publications' objectives are to serve as the primary information resource for those in attendance, and to deliver a compelling message about the Solar Decathlon's success as a proven workforce development program and its role in educating students and the public about clean energy products and design solutions. The U.S. Department of Energy 2015 Visitors Guide SD15 Visitors Guide goals are to guide attendees through the Solar Decathlon village; List and explain the 10 contests; educate attendees about the participating teams and their competition houses; provide access to more information on the Solar Decathlon website through the use of QR codes; and acknowledge the support of all event sponsors.

  2. Energy and environment design guide

    Energy Technology Data Exchange (ETDEWEB)

    Harman, K. [Royal Australian Institute of Architects, Canberra, ACT (Australia)

    1996-04-01

    The Royal Australian Institute of Architects (RAIA) released an Environment Policy for architects in September 1994 which forms part of the RAIA Code of Professional Conduct. Prior to releasing the policy, it was recognised that members needed information and education in the area of energy and environment in order to adopt and implement the guide. This document is a report on the scope, work programme and achievements of a project to provide an easy reference resource for architects and other building designers, and bring together a wide range of information and research. It includes the Environment Policy as an appendix. The project produced 24 notes entitled the `Environment Design Guide - energy/environment notes` covering a wide range of topics, and four newsletters. Feedback received from architects to date indicates that the development of the notes has had a positive effect on their knowledge of these issues, resulting in the making of informed design decisions. The topics covered by the notes are expected to expand in 1996 with the preparation of additional notes which provide information on products and sustainable construction.

  3. Renewable energy systems the earthscan expert guide to renewable energy technologies for home and business

    CERN Document Server

    Jenkins, Dilwyn

    2013-01-01

    This book is the long awaited guide for anyone interested in renewables at home or work. It sweeps away scores of common misconceptions while clearly illustrating the best in renewable and energy efficiency technologies. A fully illustrated guide to renewable energy for the home and small business, the book provides an expert overview of precisely which sustainable energy technologies are appropriate for wide-spread domestic and small business application. The sections on different renewable energy options provide detailed descriptions of each technology along with case studies, installatio

  4. Effect of the Curved Spacetime on the Electrostatic Potential Energy Distribution of Strange Stars

    Institute of Scientific and Technical Information of China (English)

    陈次星; 张家铝

    2001-01-01

    The effect of the strong gravitational field of the strange core of a strange star on its surface electrostatic potential energy distribution is discussed. We present the general-relativistic hydrodynamics equations of fluids in the presence of the electric fields and investigate the surface electrostatic potential distribution of the strange core of a strange star in hydrostatic equilibrium to correct Alcock and coworker's result [Astrophys. J. 310 (1986) 261]. Also, we discuss the temperature distribution of the bare strange star surface and give the related formulae, which may be useful if we are concerned further about the physical processes near the quark atter surfaces of strange stars.

  5. HySTAR: the hydrogen safety training and risk workplace

    International Nuclear Information System (INIS)

    Hay, R.

    2006-01-01

    This paper shows the output of the software package HySTAR, the Hydrogen Safety, Training and Risk Workplace. This is the software output of the CTFA, Canadian Hydrogen Safety Program projects. It shows the Hydrogen Virtual Interactive Expert Workplace, a guide for permitting and code enforcement for officials and other parties involved in approving hydrogen energy facilities. It also shows the Hydrogen Codes and Standards Report (Site Level) as well as Hydrogen Distances and Clearances Report

  6. Community energy and emissions planning : a guide for BC local governments

    International Nuclear Information System (INIS)

    2008-09-01

    British Columbia (BC) local governments are becoming more interested in completing an energy and greenhouse gas emissions plan for their community as awareness of climate change grows and energy prices escalate. The purpose of this guide was to support local government elected officials and staff in undertaking an energy and emissions planning process. This guide described the purpose and content of a community energy and emissions plan, its benefits, and how to go about creating one. Specifically, the guide provided practical tips, examples from BC communities, and links to more detailed information. Topics that were presented in the guide included engagement; inventories; target-setting; action plan; implementation and monitoring; and funding and resources. It was concluded that the key to long-term success is to maintain good communication with council/board, staff and the public. The document emphasized that it is important to make sure that people know the work being undertaken, and the results achieved, so that momentum is not lost. refs., tabs., figs

  7. Neutron star/red giant encounters in globular clusters

    International Nuclear Information System (INIS)

    Bailyn, C.D.

    1988-01-01

    The author presents a simple expression for the amount by which xsub(crit) is diminished as a star evolves xsub(crit) Rsub(crit)/R*, where Rsub(crit) is the maximum distance of closest approach between two stars for which the tidal energy is sufficient to bind the system, and R* is the radius of the star on which tides are being raised. Also it is concluded that tidal capture of giants by neutron stars resulting in binary systems is unlikely in globular clusters. However, collisions between neutron stars and red giants, or an alternative process involving tidal capture of a main-sequence star into an initially detached binary system, may result either in rapidly rotating neutron stars or in white dwarf/neutron star binaries. (author)

  8. Financing Energy Upgrades for K-12 School Districts: A Guide to Tapping into Funding for Energy Efficiency and Renewable Energy Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Goggio Borgeson, Merrian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Zimring, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division

    2013-04-01

    This guide focuses on clean energy financing options for school administrators, facility managers, and other K-12 school decision makers who are considering investments in high performance school projects. This guide explicitly focuses on comprehensive energy upgrades, those that involve multiple measures and are targeted toward achieving significant energy savings. Successful implementation of clean energy upgrades in schools is a matter of understanding the opportunity, making the commitment, and creatively tapping into available financing. This guide attempts to provide the foundation needed for successful projects in U.S. schools. It walks through the financing options available to K-12 schools and provides case studies of six school districts from around the country.

  9. Eco-labeling for energy efficiency and sustainability: a meta-evaluation of US programs

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Abhijit; Solomon, Barry D

    2003-01-01

    Eco-labeling is a promising market-based approach for improving the environmental performance of products through consumer choice. While eco-labeling itself is not new, eco-labeling to promote energy efficiency or sustainability is a more recent phenomenon. Five such energy-labeling programs in the US are evaluated: Green Seal, Scientific Certification Systems, Energy Guide, Energy Star, and Green-e. Of these, the first four certify energy-efficient appliances while the last one certifies renewable electricity. While Energy Guide and Energy Star are government-run programs, the rest are privately administered. Two evaluation criteria were used--consumer response and manufacturer/marketer response. Very few studies have been done on the private programs making comparative analysis more difficult. It was found that government programs, in general, and Energy Star, in particular, were much more successful than the private programs. For appliance energy labeling, the private programs were found to have an almost insignificant effect on the market. Government support proved to be crucial in determining a program's credibility, financial stability, and long-term viability. Further, targeting of specific product categories, legislative mandates, incentives, and partnerships were found to be other important factors for program success. Simple seal-of-approval logos and labels have generally affected consumer behavior more than the complex information-disclosure labels.

  10. Eco-labeling for energy efficiency and sustainability: a meta-evaluation of US programs

    International Nuclear Information System (INIS)

    Banerjee, Abhijit; Solomon, Barry D.

    2003-01-01

    Eco-labeling is a promising market-based approach for improving the environmental performance of products through consumer choice. While eco-labeling itself is not new, eco-labeling to promote energy efficiency or sustainability is a more recent phenomenon. Five such energy-labeling programs in the US are evaluated: Green Seal, Scientific Certification Systems, Energy Guide, Energy Star, and Green-e. Of these, the first four certify energy-efficient appliances while the last one certifies renewable electricity. While Energy Guide and Energy Star are government-run programs, the rest are privately administered. Two evaluation criteria were used--consumer response and manufacturer/marketer response. Very few studies have been done on the private programs making comparative analysis more difficult. It was found that government programs, in general, and Energy Star, in particular, were much more successful than the private programs. For appliance energy labeling, the private programs were found to have an almost insignificant effect on the market. Government support proved to be crucial in determining a program's credibility, financial stability, and long-term viability. Further, targeting of specific product categories, legislative mandates, incentives, and partnerships were found to be other important factors for program success. Simple seal-of-approval logos and labels have generally affected consumer behavior more than the complex information-disclosure labels

  11. Alternative Energy: A Guide to Free Information for Educators.

    Science.gov (United States)

    White, Janet A.

    This guide was compiled to help teachers and students locate free educational materials (both lessons and nontechnical background references) on renewable energy resources and energy conservation. The 214 entries are arranged by these topic areas: (1) energy efficiency and renewables; (2) biomass; (3) hydropower; (4) solar thermal energy; (5)…

  12. International nuclear energy guide

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The aim of this French-English bilingual Guide is to present a synthesis embracing all the aspects and all the implications of the development of nuclear energy by situating it both within the French administrative and professional framework and in the world context. Special attention has been paid to the protection of man and the environment and to safety and security problems; most of the other questions -technological, economic, industrial- which arise at all points in the nuclear cycle. Teaching and research are outlined and a special appendix is devoted to nuclear information [fr

  13. The star book an introduction to stargazing and the solar system

    CERN Document Server

    Grego, Peter

    2012-01-01

    An Introduction to Stargazing and the Solar System is an introductory section taken from The Star Book that guides you through the night skies, from the history and lives of the stars, to deep-sky objects beyond the Milky Way, and the Celestial Sphere. Followed by an introductory guide to the solar system with high quality images and observational drawings of the planets, covering the Sun, Moon, Inferior and Superior planets. Everyone is interested in the stars and on a clear night astonished by them. The Star Book will answer any questions you may have whe

  14. Manual on high energy teletherapy. Incorporating: Applications guide, procedures guide, basics guide

    International Nuclear Information System (INIS)

    1996-01-01

    This publication is part of practical radiation safety manual series for different fields of application aimed primarily at persons handling radiation sources on a daily routine basis, which could at same time be used by the competent authorities, supporting their efforts in the radiation protection training of workers or medical assistance personnel or helping on-site management to set up local radiation protection rules. It is dedicated to high energy radiotherapy: its application and procedures guides

  15. Energy Technology Roadmaps: A Guide to Development and Implementation. 2014 edition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-03-01

    New low-carbon technologies show clear potential for transforming the global energy system, but a key challenge remains: what steps do governments and industry need to take to ensure their development and deployment? Roadmapping, used for decades in technology-intensive industries, is a useful tool to help address complicated issues strategically at the national, regional and global levels. To help turn political statements and analytical work into concrete action, the International Energy Agency (IEA) is developing a series of global roadmaps devoted to low-carbon energy technologies. Drawing upon the extensive IEA experience, this guide is aimed at providing countries and companies with the context, information and tools needed to design, manage and implement an effective energy technology roadmap process relevant to their own local circumstances and objectives. This edition of the Energy Technology Roadmaps: a guide to development and implementation includes more detailed guidance on how to identify key stakeholders, develop a technology baseline and development of indicators to help track progress against roadmap milestones. The IEA hopes that this guide and the examples and references it offers, together with the new IEA How2Guides, which provide technology-specific guidance, will help national and local policy makers and industry to develop strategies that accelerate the deployment of low-carbon energy technologies worldwide.

  16. Nuclear physics of stars

    CERN Document Server

    Iliadis, Christian

    2015-01-01

    Most elements are synthesized, or ""cooked"", by thermonuclear reactions in stars. The newly formed elements are released into the interstellar medium during a star's lifetime, and are subsequently incorporated into a new generation of stars, into the planets that form around the stars, and into the life forms that originate on the planets. Moreover, the energy we depend on for life originates from nuclear reactions that occur at the center of the Sun. Synthesis of the elements and nuclear energy production in stars are the topics of nuclear astrophysics, which is the subject of this book

  17. SPECTRAL ENERGY DISTRIBUTIONS OF YOUNG STARS IN IC 348: THE ROLE OF DISKS IN ANGULAR MOMENTUM EVOLUTION OF YOUNG, LOW-MASS STARS

    International Nuclear Information System (INIS)

    Le Blanc, Thompson S.; Stassun, Keivan G.; Covey, Kevin R.

    2011-01-01

    Theoretical work suggests that a young star's angular momentum content and rotation rate may be strongly influenced by magnetic interactions with its circumstellar disk. A generic prediction of these 'disk-locking' theories is that a disk-locked star will be forced to co-rotate with the Keplerian angular velocity of the inner edge of the disk; that is, the disk's inner-truncation radius should equal its co-rotation radius. These theories have also been interpreted to suggest a gross correlation between young stars' rotation periods and the structural properties of their circumstellar disks, such that slowly rotating stars possess close-in disks that enforce the star's slow rotation, whereas rapidly rotating stars possess anemic or evacuated inner disks that are unable to brake the stars and instead the stars spin up as they contract. To test these expectations, we model the spectral energy distributions (SEDs) of 33 young stars in IC 348 with known rotation periods and infrared excesses indicating the presence of circumstellar disks. For each star, we match the observed SED, typically sampling 0.6-8.0 μm, to a grid of 200,000 pre-computed star+disk radiative transfer models, from which we infer the disk's inner-truncation radius. We then compare this truncation radius to the disk's co-rotation radius, calculated from the star's measured rotation period. We do not find obvious differences in the disk truncation radii of slow rotators versus rapid rotators. This holds true both at the level of whether close-in disk material is present at all, and in analyzing the precise location of the inner disk edge relative to the co-rotation radius among the subset of stars with close-in disk material. One interpretation is that disk locking is unimportant for the IC 348 stars in our sample. Alternatively, if disk locking does operate, then it must operate on both the slow and rapid rotators, potentially producing both spin-up and spin-down torques, and the transition from the

  18. Neutron Star Science with the NuSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-16

    The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, helped scientists obtain for the first time a sensitive high-­energy X-­ray map of the sky with extraordinary resolution. This pioneering telescope has aided in the understanding of how stars explode and neutron stars are born. LLNL is a founding member of the NuSTAR project, with key personnel on its optics and science team. We used NuSTAR to observe and analyze the observations of different neutron star classes identified in the last decade that are still poorly understood. These studies not only help to comprehend newly discovered astrophysical phenomena and emission processes for members of the neutron star family, but also expand the utility of such observations for addressing broader questions in astrophysics and other physics disciplines. For example, neutron stars provide an excellent laboratory to study exotic and extreme phenomena, such as the equation of state of the densest matter known, the behavior of matter in extreme magnetic fields, and the effects of general relativity. At the same time, knowing their accurate populations has profound implications for understanding the life cycle of massive stars, star collapse, and overall galactic evolution.

  19. Eco-labeling for energy efficiency and sustainability: a meta-evaluation of US programs

    Energy Technology Data Exchange (ETDEWEB)

    Abhijit Banerjee [University of Delaware, Newark, DE (United States). Center for Energy and Environmental Policy; Solomon, B.D. [Michigan Technological University, Houghton, MI (United States). Dept. of Social Sciences

    2003-01-01

    Eco-labeling is a promising market-based approach for improving the environmental performance of products through consumer choice. While eco-labeling itself is not new, eco-labeling to promote energy efficiency or sustainability is a more recent phenomenon. Five such energy-labeling programs in the US are evaluated: Green Seal, Scientific Certification Systems, Energy Guide, Energy Star, and Green-e. Of these, the first four certify energy-efficient appliances while the last one certifies renewable electricity. While Energy Guide and Energy Star are government-run programs, the rest are privately administered. Two evaluation criteria were used - consumer response and manufacturer/marketer response. Very few studies have been done on the private programs making comparative analysis more difficult. It was found that government programs, in general, and Energy Star, in particular, were much more successful than the private programs. For appliance energy labeling, the private programs were found to have an almost insignificant effect on the market. Government support proved to be crucial in determining a program's credibility, financial stability, and long-term viability. Further, targeting of specific product categories, legislative mandates, incentives, and partnerships were found to be other important factors for program success. Simple seal-of-approval logos and labels have generally affected consumer behavior more than the complex information-disclosure labels. (author)

  20. CHAPTER 1. Miktoarm Star (µ-Star) Polymers: A Successful Story

    KAUST Repository

    Iatrou, Hermis; Avgeropoulos, Apostolos; Sakellariou, Georgios; Pitsikalis, Marinos; Hadjichristidis, Nikolaos

    2017-01-01

    The term miktoarm stars (coming from the Greek word μιτσ meaning mixed) was adopted in 1992 by our group for star polymers with either chemical (e.g., AB), molecular weight (e.g., AA′), topological (e.g., (AB)-junction-(BA)), or functional group (e.g., AA) asymmetry. The first μ-stars synthesized by anionic polymerization, on the one hand, guided polymer chemists working with other types of polymerization techniques towards this direction and, on the other hand, helped polymer physicists to carry out experiments and develop theories on the influence of the architecture on the morphology of block copolymers. Synthetic strategies based on anionic polymerization, as well as a few examples showing the influence of the miktoarm structure on the morphology of block copolymers, are reviewed in this chapter.

  1. CHAPTER 1. Miktoarm Star (µ-Star) Polymers: A Successful Story

    KAUST Repository

    Iatrou, Hermis

    2017-04-13

    The term miktoarm stars (coming from the Greek word μιτσ meaning mixed) was adopted in 1992 by our group for star polymers with either chemical (e.g., AB), molecular weight (e.g., AA′), topological (e.g., (AB)-junction-(BA)), or functional group (e.g., AA) asymmetry. The first μ-stars synthesized by anionic polymerization, on the one hand, guided polymer chemists working with other types of polymerization techniques towards this direction and, on the other hand, helped polymer physicists to carry out experiments and develop theories on the influence of the architecture on the morphology of block copolymers. Synthetic strategies based on anionic polymerization, as well as a few examples showing the influence of the miktoarm structure on the morphology of block copolymers, are reviewed in this chapter.

  2. Energy efficiency improvement and cost saving opportunities forpetroleum refineries

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Galitsky, Christina

    2005-02-15

    The petroleum refining industry in the United States is the largest in the world, providing inputs to virtually any economic sector,including the transport sector and the chemical industry. The industry operates 146 refineries (as of January 2004) around the country,employing over 65,000 employees. The refining industry produces a mix of products with a total value exceeding $151 billion. Refineries spend typically 50 percent of cash operating costs (i.e., excluding capital costs and depreciation) on energy, making energy a major cost factor and also an important opportunity for cost reduction. Energy use is also a major source of emissions in the refinery industry making energy efficiency improvement an attractive opportunity to reduce emissions and operating costs. Voluntary government programs aim to assist industry to improve competitiveness through increased energy efficiency and reduced environmental impact. ENERGY STAR (R), a voluntary program managed by the U.S. Environmental Protection Agency, stresses the need for strong and strategic corporate energy management programs. ENERGY STAR provides energy management tools and strategies for successful corporate energy management programs. This Energy Guide describes research conducted to support ENERGY STAR and its work with the petroleum refining industry.This research provides information on potential energy efficiency opportunities for petroleum refineries. This Energy Guide introduces energy efficiency opportunities available for petroleum refineries. It begins with descriptions of the trends, structure, and production of the refining industry and the energy used in the refining and conversion processes. Specific energy savings for each energy efficiency measure based on case studies of plants and references to technical literature are provided. If available, typical payback periods are also listed. The Energy Guide draws upon the experiences with energy efficiency measures of petroleum refineries worldwide

  3. Flare stars

    International Nuclear Information System (INIS)

    Nicastro, A.J.

    1981-01-01

    The least massive, but possibly most numerous, stars in a galaxy are the dwarf M stars. It has been observed that some of these dwarfs are characterized by a short increase in brightness. These stars are called flare stars. These flare stars release a lot of energy in a short amount of time. The process producing the eruption must be energetic. The increase in light intensity can be explained by a small area rising to a much higher temperature. Solar flares are looked at to help understand the phenomenon of stellar flares. Dwarfs that flare are observed to have strong magnetic fields. Those dwarf without the strong magnetic field do not seem to flare. It is believed that these regions of strong magnetic fields are associated with star spots. Theories on the energy that power the flares are given. Astrophysicists theorize that the driving force of a stellar flare is the detachment and collapse of a loop of magnetic flux. The mass loss due to stellar flares is discussed. It is believed that stellar flares are a significant contributor to the mass of interstellar medium in the Milky Way

  4. Solar Energy Installers Curriculum Guides. Final Report.

    Science.gov (United States)

    Walker, Gene C.

    A project was conducted to develop solar energy installers curriculum guides for use in high school vocational centers and community colleges. Project activities included researching job competencies for the heating, ventilation, and air conditioning industry and determining through interviews and manufacturers' literature what additional…

  5. TURBOVELOCITY STARS: KICKS RESULTING FROM THE TIDAL DISRUPTION OF SOLITARY STARS

    International Nuclear Information System (INIS)

    Manukian, Haik; Guillochon, James; Ramirez-Ruiz, Enrico; O'Leary, Ryan M.

    2013-01-01

    The centers of most known galaxies host supermassive black holes (SMBHs). In orbit around these black holes are a centrally concentrated distribution of stars, both in single and in binary systems. Occasionally, these stars are perturbed onto orbits that bring them close to the SMBH. If the star is in a binary system, the three-body interaction with the SMBH can lead to large changes in orbital energy, depositing one of the two stars on a tightly-bound orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In this Letter, we show that the disruption of solitary stars can also lead to large positive increases in orbital energy. The kick velocity depends on the amount of mass the star loses at pericenter, but not on the ratio of black hole to stellar mass, and are at most the star's own escape velocity. We find that these kicks are usually too small to result in the ejection of stars from the Milky Way, but can eject the stars from the black hole's sphere of influence, reducing their probability of being disrupted again. We estimate that ∼ 10 5 stars, ∼ 1% of all stars within 10 pc of the galactic center, are likely to have had mass removed by the central black hole through tidal interaction, and speculate that these 'turbovelocity' stars will at first be redder, but eventually bluer, and always brighter than their unharassed peers.

  6. Motion-blurred star acquisition method of the star tracker under high dynamic conditions.

    Science.gov (United States)

    Sun, Ting; Xing, Fei; You, Zheng; Wei, Minsong

    2013-08-26

    The star tracker is one of the most promising attitude measurement devices used in spacecraft due to its extremely high accuracy. However, high dynamic performance is still one of its constraints. Smearing appears, making it more difficult to distinguish the energy dispersive star point from the noise. An effective star acquisition approach for motion-blurred star image is proposed in this work. The correlation filter and mathematical morphology algorithm is combined to enhance the signal energy and evaluate slowly varying background noise. The star point can be separated from most types of noise in this manner, making extraction and recognition easier. Partial image differentiation is then utilized to obtain the motion parameters from only one image of the star tracker based on the above process. Considering the motion model, the reference window is adopted to perform centroid determination. Star acquisition results of real on-orbit star images and laboratory validation experiments demonstrate that the method described in this work is effective and the dynamic performance of the star tracker could be improved along with more identified stars and guaranteed position accuracy of the star point.

  7. Laser guide stars for daytime thermal IR observations

    Science.gov (United States)

    Beckers, Jacques M.

    2008-04-01

    In connection with the planning for Extremely Large Telescopes, I revisit a 2001 paper in which Cacciani and I describe the use of Sodium Laser Guide Stars (LGSs) for diffraction limited daytime astronomical observations. The enabling technology for seeing LGSs in broad daylight is the availability of very narrow band magneto-optical filters. Considering the dominance of the atmospheric scattering of sunlight at wavelengths below 3.5 μm, daytime use is only indicated for mid- and thermal IR observations. The launch of the 6.5 meter aperture James Web Space Telescope (JWST) appears to be assured and planned for 2013, preceding the most optimistic projections for the completion date of the first ELT. The projected thermal background of the JWST is very much less than that of ground-based telescopes so that any competing ground-based observations are limited to those parameters not covered by the JWST: angular resolution (requiring apertures > 6.5 meter) and spectral resolution (R>3000). I compare the benefits of daytime observations with Na-LGS equipped telescopes and interferometers at moderate latitudes and in the Antarctic (specifically Dome C). In both cases daytime observations extend the amount of observing time available for TIR observations. Antarctic observations have the advantage of having very good seeing during the daytime, significantly better than nighttime seeing. In contrast the seeing at moderate latitude sites significantly deteriorates during daytime resulting in lower quality observations than during nighttime. In addition Antarctic sites are less hostile to maintenance and operations during daytime (summer) observations as compared to nighttime (winter) observations.

  8. The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-ray Mission

    Science.gov (United States)

    Harrison, Fiona A.; Craig, Willliam W.; Christensen, Finn E.; Hailey, Charles J.; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Cook, W. Rick; Forster, Karl; Giommi, Paolo; hide

    2013-01-01

    High-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the 10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to thepeak epoch of galaxy assembly in the universe (at z 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6 inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.

  9. Spectrophotometry of carbon stars

    Energy Technology Data Exchange (ETDEWEB)

    Oganesyan, R.K.; Karapetyan, M.S.; Nersisyan, S.E.

    1986-01-01

    The results are given of the spectrophotometric investigation of 56 carbon stars in the spectral range from 4000 to 6800 A with resolution 3 A. The observed energy distributions of these stars are determined relative to the flux at the wavelength /sub 0/ = 5556; they are presented in the form of graphs. The energy distributions have been obtained for the first time for 35 stars. Variation in the line Ba II 4554 A has been found in the spectra of St Cam, UU Aur, and RV Mon. Large changes have taken place in the spectra of RT UMa and SS Vir. It is noted that the spectra of carbon stars have a depression, this being situated in different spectral regions for individual groups of stars.

  10. Star/galaxy separation at faint magnitudes: Application to a simulated Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Soumagnac, M.T.; et al.

    2013-06-21

    We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the Gravitational Weak Lensing and Large Scale Structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by Point Spread Function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use Principal Component Analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multi-parameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SExtractor), especially at faint magnitudes: it increases the purity by up to 20% for stars and by up to 12% for galaxies, at i-magnitude fainter than 23.

  11. Star/galaxy separation at faint magnitudes: application to a simulated Dark Energy Survey

    Energy Technology Data Exchange (ETDEWEB)

    Soumagnac, M. T.; Abdalla, F. B.; Lahav, O.; Kirk, D.; Sevilla, I.; Bertin, E.; Rowe, B. T. P.; Annis, J.; Busha, M. T.; Da Costa, L. N.; Frieman, J. A.; Gaztanaga, E.; Jarvis, M.; Lin, H.; Percival, W. J.; Santiago, B. X.; Sabiu, C. G.; Wechsler, R. H.; Wolz, L.; Yanny, B.

    2015-04-14

    We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the gravitational weak lensing and large-scale structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by point spread function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use principal component analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multiparameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SExtractor), especially at faint magnitudes: it increases the purity by up to 20 per cent for stars and by up to 12 per cent for galaxies, at i-magnitude fainter than 23.

  12. Best Practices Guide for Energy-Efficient Data Center Design: Revised March 2011 (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-03-01

    This guide provides an overview of best practices for energy-efficient data center design which spans the categories of Information Technology (IT) systems and their environmental conditions, data center air management, cooling and electrical systems, on-site generation, and heat recovery. IT system energy efficiency and environmental conditions are presented first because measures taken in these areas have a cascading effect of secondary energy savings for the mechanical and electrical systems. This guide concludes with a section on metrics and benchmarking values by which a data center and its systems energy efficiency can be evaluated. No design guide can offer 'the most energy-efficient' data center design but the guidelines that follow offer suggestions that provide efficiency benefits for a wide variety of data center scenarios.

  13. Technology Roadmaps: How2Guide for Wind Energy Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-03-01

    Whether in OECD, emerging or developing country economies, governments are increasingly looking to diversify their energy mix beyond simply fossil fuels. While wind energy is developing towards a mainstream, competitive and reliable technology, a range of barriers can delay progress, such as financing, grid integration, social acceptance and aspects of planning processes. National and regional technology roadmaps can play a key role in supporting wind energy development and implementation, helping countries to identify priorities and pathways tailored to local resources and markets. Recognising this, the IEA has started the How2Guides - a new series co-ordinated by the International Low-Carbon Energy Technology Platform to address the need for more focused guidance in the development of national roadmaps, or strategies, for specific low-carbon technologies. This builds on the success of the IEA global technology roadmap series and responds to a growing number of requests for IEA guidance to adapt the findings of the IEA global technology roadmaps to national circumstances. A successful roadmap contains a clear statement of the desired outcome, followed by a specific pathway for reaching it. The How2Guide for Wind Energy builds on the IEA well established methodology for roadmap development and shares wind specific recommendations on how to address the four phases to developing and implementing a wind energy roadmap: Planning; Visioning; Development; and Implementation. The manual also offers menus of recommendations on policy and technical options for deployment of utility-scale wind energy installations. A matrix of barriers-versus-realistic solutions options is cross-listed with considerations such as planning, development, electricity market and system, infrastructure, and finance and economics. Drawing on several case studies from around the globe, as well as on the IEA Technology Roadmap for Wind Energy, the How2Guide for Wind Energy it is intended as a

  14. A Model for Infusing Energy Concepts into Vocational Education Programs. Solar Energy Curriculum Guide.

    Science.gov (United States)

    Delta Vocational Technical School, Marked Tree, AR.

    This solar energy curriculum guide is designed to assist teachers in infusing energy concepts into vocational education programs. It consists of 31 competency-based instructional units organized into 10 sections. Covered in the sections are the following topics: related instructions (history and development; human relations; general safety;…

  15. Spectral energy distributions of T Tauri stars - disk flaring and limits on accretion

    International Nuclear Information System (INIS)

    Kenyon, S.J.; Hartmann, L.

    1987-01-01

    The Adams et al. (1987) conclusion that much of the IR excess emission in the spectral energy distribution of T Tauri stars arises from reprocessing of stellar radiation by a dusty circumstellar disk is presently supported by analyses conducted in light of various models of these stars' spectra. A low mass reprocessing disk can, however, produce these spectra as well as a massive accretion disk. The detection of possible boundary layer radiation in the optical and near-UV regions poses the strongest limits on accretion rates. Disk accretion in the T Tauri phase does not significantly modify stellar evolution. 85 references

  16. Energy Efficient Wireless Vehicular-Guided Actuator Network

    KAUST Repository

    Boudellioua, Imene

    2013-06-09

    In this paper, we present an energy-efficient vehicular guided system for environmental disaster management using wireless sensor/actuator networks. Sensor nodes within clusters are controlled by a master node that is dynamically selected. Actuators support mobility for every sensor node in the area of interest. The system maintains energy efficiency using statistical, correlation, and confidence for determining actuator actions and implements an adaptive energy scheme to prolong the system lifespan. Experimental results show that the system is capable of saving up to 2.7Watt for every 28KByte of data exchanged. We also show that actuator actions are correct with a 90% confidence.

  17. Neutron stars as X-ray burst sources. II. Burst energy histograms and why they burst

    International Nuclear Information System (INIS)

    Baan, W.A.

    1979-01-01

    In this work we explore some of the implications of a model for X-ray burst sources where bursts are caused by Kruskal-Schwarzschild instabilities at the magnetopause of an accreting and rotating neutron star. A number of simplifying assumptions are made in order to test the model using observed burst-energy histograms for the rapid burster MXB 1730--335. The predicted histograms have a correct general shape, but it appears that other effects are important as well, and that mode competition, for instance, may suppress the histograms at high burst energies. An explanation is ventured for the enhancement in the histogram at the highest burst energies, which produces the bimodal shape in high accretion rate histograms. Quantitative criteria are given for deciding when accreting neutron stars are steady sources or burst sources, and these criteria are tested using the X-ray pulsars

  18. Full PWA Report: An Assessment of Energy, Waste, and Productivity Improvements for North Star Steel Iowa

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-06-25

    North Star Steel's Wilton, Iowa plant (NSSI) was awarded a subcontract through a competitive process to use Department of Energy/OIT funding to examine potential processes and technologies that could save energy, reduce waste, and increase productivity.

  19. Renewable Energy Data, Analysis, and Decisions: A Guide for Practitioners

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sarah L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lopez, Anthony J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Watson, Andrea C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Grue, Nicholas W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Leisch, Jennifer E. [United States Agency for International Development (USAID)

    2018-03-16

    High-quality renewable energy resource data and other geographic information system (GIS) data are essential for the transition to a clean energy economy that prioritizes local resources, improves resiliency, creates jobs, and promotes energy independence. This guide is intended to support policymakers and planners, as well as technical experts, consultants, and academics in incorporating improved data and analysis into renewable energy decision-making.

  20. Energy efficiency the definitive guide to the cheapest, cleanest, fastest source of energy

    CERN Document Server

    Fawkes, Steven

    2013-01-01

    Energy risk has reappeared on the corporate and social agenda with a bang and the complexity of the issues has increased many-fold since the days of the last great wave of concern following the oil crises of the 1970s. Steven Fawkes' Energy Efficiency is a comprehensive guide for managers and policy-makers to the fundamental questions underpinning energy-efficiency and our responses to it: ¢ what do we really mean by energy efficiency? ¢ what is the potential (in different dimensions)? ¢ why it is important? ¢ what management processes lead to optimisation of energy efficiency? ¢ what technolo

  1. Technical Support Document: The Development of the Advanced Energy Design Guide for Small Retail Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing; Jarnagin, Ronald E.; Winiarski, David W.; Jiang, Wei; McBride, Merle F.; Crall, C.

    2006-09-30

    The Advanced Energy Design Guide for Small Retail Buildings (AEDG-SR) was developed by a partnership of organizations, including the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IESNA), the United States Green Buildings Council (USGBC), and the Department of Energy (DOE). The guide is intended to offer recommendations to achieve 30% energy savings and thus to encourage steady progress towards net-zero energy buildings. The baseline level energy use was set at buildings built at the turn of the millennium, which are assumed to be based on ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings (refer to as the ?Standard? in this report). ASHRAE and its partners are engaged in the development of a series of guides for small commercial buildings, with the AEDG-SR being the second in the series. Previously the partnership developed the Advanced Energy Design Guide for Small Office Buildings: Achieving 30% Energy Savings Over ANSI/ASHRAE/IESNA Standard 90.1-1999, which was published in late 2004. The technical support document prepared by PNNL details how the energy analysis performed in support of the Guide and documents development of recommendation criteria.

  2. Energy Efficiency Improvement and Cost Saving Opportunities for Breweries: An ENERGY STAR(R) Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Martin, Nathan; Worrell, Ernst; Lehman, Bryan

    2003-09-01

    Annually, breweries in the United States spend over $200 million on energy. Energy consumption is equal to 38 percent of the production costs of beer, making energy efficiency improvement an important way to reduce costs, especially in times of high energy price volatility. After a summary of the beer making process and energy use, we examine energy efficiency opportunities available for breweries. We provide specific primary energy savings for each energy efficiency measure based on case studies that have implemented the measures, as well as references to technical literature. If available, we have also listed typical payback periods. Our findings suggest that given available technology, there are still opportunities to reduce energy consumption cost-effectively in the brewing industry. Brewers value highly the quality, taste and drinkability of their beer. Brewing companies have and are expected to continue to spend capital on cost-effective energy conservation measures that meet these quality, taste and drinkability requirements. For individual plants, further research on the economics of the measures, as well as their applicability to different brewing practices, is needed to assess implementation of selected technologies.

  3. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance, K-12 Schools (Book)

    Energy Technology Data Exchange (ETDEWEB)

    2013-12-01

    The U.S. Department of Energy developed the Advanced Energy Retrofit Guides (AERGs) to provide specific methodologies, information, and guidance to help energy managers and other stakeholders plan and execute energy efficiency improvements. Detailed technical discussion is fairly limited. Instead, we emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluations of the most promising retrofit energy efficiency measures for each building type. A series of AERGs is under development, addressing key segments of the commercial building stock. K-12 schools were selected as one of the highest priority building sectors, because schools affect the lives of most Americans. They also represent approximately 8% of the energy use and 10% of the floor area in commercial buildings nationwide. U.S. K-12 school districts spend more than $8 billion each year on energy - more than they spend on computers and textbooks combined. Most occupy older buildings that often have poor operational performance - more than 30% of schools were built before 1960. The average age of a school is about 42 years - which is nearly the expected serviceable lifespan of the building. K-12 schools offer unique opportunities for deep, cost-effective energy efficiency improvements, and this guide provides convenient and practical guidance for exploiting these opportunities in the context of public, private, and parochial schools.

  4. Neutron Stars and NuSTAR

    Science.gov (United States)

    Bhalerao, Varun

    2012-05-01

    My thesis centers around the study of neutron stars, especially those in massive binary systems. To this end, it has two distinct components: the observational study of neutron stars in massive binaries with a goal of measuring neutron star masses and participation in NuSTAR, the first imaging hard X-ray mission, one that is extremely well suited to the study of massive binaries and compact objects in our Galaxy. The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing high energy X-ray telescope to orbit. NuSTAR has an order-of-magnitude better angular resolution and has two orders of magnitude higher sensitivity than any currently orbiting hard X-ray telescope. I worked to develop, calibrate, and test CdZnTe detectors for NuSTAR. I describe the CdZnTe detectors in comprehensive detail here - from readout procedures to data analysis. Detailed calibration of detectors is necessary for analyzing astrophysical source data obtained by the NuSTAR. I discuss the design and implementation of an automated setup for calibrating flight detectors, followed by calibration procedures and results. Neutron stars are an excellent probe of fundamental physics. The maximum mass of a neutron star can put stringent constraints on the equation of state of matter at extreme pressures and densities. From an astrophysical perspective, there are several open questions in our understanding of neutron stars. What are the birth masses of neutron stars? How do they change in binary evolution? Are there multiple mechanisms for the formation of neutron stars? Measuring masses of neutron stars helps answer these questions. Neutron stars in high-mass X-ray binaries have masses close to their birth mass, providing an opportunity to disentangle the role of "nature" and "nurture" in the observed mass distributions. In 2006, masses had been measured for only six such objects, but this small sample showed the greatest diversity in masses

  5. Effect of pressurization on helical guided wave energy velocity in fluid-filled pipes.

    Science.gov (United States)

    Dubuc, Brennan; Ebrahimkhanlou, Arvin; Salamone, Salvatore

    2017-03-01

    The effect of pressurization stresses on helical guided waves in a thin-walled fluid-filled pipe is studied by modeling leaky Lamb waves in a stressed plate bordered by fluid. Fluid pressurization produces hoop and longitudinal stresses in a thin-walled pipe, which corresponds to biaxial in-plane stress in a plate waveguide model. The effect of stress on guided wave propagation is accounted for through nonlinear elasticity and finite deformation theory. Emphasis is placed on the stress dependence of the energy velocity of the guided wave modes. For this purpose, an expression for the energy velocity of leaky Lamb waves in a stressed plate is derived. Theoretical results are presented for the mode, frequency, and directional dependent variations in energy velocity with respect to stress. An experimental setup is designed for measuring variations in helical wave energy velocity in a thin-walled water-filled steel pipe at different levels of pressure. Good agreement is achieved between the experimental variations in energy velocity for the helical guided waves and the theoretical leaky Lamb wave solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Global Infrared–Radio Spectral Energy Distributions of Galactic Massive Star-Forming Regions

    Science.gov (United States)

    Povich, Matthew Samuel; Binder, Breanna Arlene

    2018-01-01

    We present a multiwavelength study of 30 Galactic massive star-forming regions. We fit multicomponent dust, blackbody, and power-law continuum models to 3.6 µm through 10 mm spectral energy distributions obtained from Spitzer, MSX, IRAS, Herschel, and Planck archival survey data. Averaged across our sample, ~20% of Lyman continuum photons emitted by massive stars are absorbed by dust before contributing to the ionization of H II regions, while ~50% of the stellar bolometric luminosity is absorbed and reprocessed by dust in the H II regions and surrounding photodissociation regions. The most luminous, infrared-bright regions that fully sample the upper stellar initial mass function (ionizing photon rates NC ≥ 1050 s–1 and total infrared luminosity LTIR ≥ 106.8 L⊙) have higher percentages of absorbed Lyman continuum photons (~40%) and dust-reprocessed starlight (~80%). The monochromatic 70-µm luminosity L70 is linearly correlated with LTIR, and on average L70/LTIR = 50%, in good agreement with extragalactic studies. Calibrated against the known massive stellar content in our sampled H II regions, we find that star formation rates based on L70 are in reasonably good agreement with extragalactic calibrations, when corrected for the smaller physical sizes of the Galactic regions. We caution that absorption of Lyman continuum photons prior to contributing to the observed ionizing photon rate may reduce the attenuation-corrected Hα emission, systematically biasing extragalactic calibrations toward lower star formation rates when applied to spatially-resolved studies of obscured star formation.This work was supported by the National Science Foundation under award CAREER-1454333.

  7. Transition density and pressure in hot neutron stars

    International Nuclear Information System (INIS)

    Xu Jun; Chen Liewen; Ko, Che Ming; Li Baoan

    2010-01-01

    Using the momentum-dependent effective interaction (MDI) for nucleons, we have studied the transition density and pressure at the boundary between the inner crust and the liquid core of hot neutron stars. We find that their values are larger in neutrino-trapped neutron stars than in neutrino-free neutron stars. Furthermore, both are found to decrease with increasing temperature of a neutron star as well as increasing slope parameter of the nuclear symmetry energy, except that the transition pressure in neutrino-trapped neutron stars for the case of small symmetry energy slope parameter first increases and then decreases with increasing temperature. We have also studied the effect of the nuclear symmetry energy on the critical temperature above which the inner crust in a hot neutron star disappears and found that with increasing value of the symmetry energy slope parameter, the critical temperature decreases slightly in neutrino-trapped neutron stars but first decreases and then increases in neutrino-free neutron stars.

  8. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  9. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    International Nuclear Information System (INIS)

    Liu Tie; Wu Yuefang; Zhang Huawei; Qin Shengli

    2012-01-01

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10 3 cm –3 and kinematic temperature ∼20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  10. Book Review: "Inside Stars. A Theory of the Internal Constitution of Stars, and the Sources of Stellar Energy According to General Relativity" (Letters to Progress in Physics

    Directory of Open Access Journals (Sweden)

    Millette P. A.

    2014-01-01

    Full Text Available This book provides a general relativistic theory of the internal constitution of liquid stars. It is a solid contribution to our understanding of stellar structure from a general relativistic perspective. It raises new ideas on the constitution of stars and planetary systems, and proposes a new approach to stellar structure an d stellar energy generation which is bound to help us better understand stellar astrophysics.

  11. Metallicity and the spectral energy distribution and spectral types of dwarf O-stars

    NARCIS (Netherlands)

    Mokiem, MR; Martin-Hernandez, NL; Lenorzer, A; de Koter, A; Tielens, AGGA

    We present a systematic study of the effect of metallicity on the stellar spectral energy distribution (SED) of 0 main sequence (dwarf) stars, focussing on the hydrogen and helium ionizing continua, and on the optical and near-IR lines used for spectral classification. The spectra are based on

  12. Metallicity and the spectral energy distribution and spectral types of dwarf O-stars

    NARCIS (Netherlands)

    Mokiem, M.R.; Martín-Hernández, N.L.; Lenorzer, A.; de Koter, A.; Tielens, A.G.G.M.

    2004-01-01

    We present a systematic study of the effect of metallicity on the stellar spectral energy distribution (SED) of O main sequence (dwarf) stars, focussing on the hydrogen and helium ionizing continua, and on the optical and near-IR lines used for spectral classification. The spectra are based on

  13. The formation of stars

    CERN Document Server

    Stahler, Steven W

    2008-01-01

    This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text f

  14. Strange-quark-matter stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-11-01

    We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 13 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to consist of individual hadrons. We conclude that it is implausible that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, is a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation if strange matter is stable at an energy density exceeding about 5.4 times that of nuclear matter. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 34 refs., 10 figs., 1 tab

  15. Boston in Top 25 of EPA’s List of Cities with the Most Energy Star Certified Buildings

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has announced its tenth annual Top Cities list, which ranks the 25 U.S. metropolitan areas with the most Energy Star certified buildings and superior energy performance in the preceding calendar year.

  16. Low Density Symmetry Energy Effects and the Neutron Star Crust Properties

    International Nuclear Information System (INIS)

    Kubis, S.; Alvarez-Castillo, D.E.; Porebska, J.

    2010-01-01

    The form of the nuclear symmetry energy E s around saturation point density leads to a different crust-core transition point in the neutron star and affects the crust properties. We show that the knowledge of E s close to the saturation point is not sufficient to determine the position of the transition point and the very low density behaviour is required. We also claim that crust properties are strongly influenced by the very high density behaviour of E s , so in order to conclude about the form of low density part of the symmetry energy from astrophysical data one must isolate properly the high density part. (authors)

  17. Constraints on the symmetry energy from neutron star equation of state

    CERN Document Server

    Miyazaki, K

    2006-01-01

    We develop an equation of state (EOS) for neutron star (NS) matter, which forbids the direct URCA cooling and satisfies the recent information on the mass and the radius, simultaneously. At sub-saturation densities, the symmetry energy of the EOS is well described by a function E_{sym}(\\rho)=31.6(\\rho/\\rho_0)^{\\gamma} with 0.70\\leq\\gamma\\leq0.77. This constraint on the density dependence of the symmetry energy is much severer than that obtained from the analysis of the isospin diffusion date in heavy-ion collisions. Consequently, we can obtain the valuable information on nuclear matter from the astrophysical observations of NSs.

  18. Carbon Stars T. Lloyd Evans

    Indian Academy of Sciences (India)

    that the features used in estimating luminosities of ordinary giant stars are just those whose abundance ... This difference between the spectral energy distributions (SEDs) of CH stars and the. J stars, which belong to .... that the first group was binaries, as for the CH stars of the solar vicinity, while those of the second group ...

  19. The Performance of the Robo-AO Laser Guide Star Adaptive Optics System at the Kitt Peak 2.1 m Telescope

    Science.gov (United States)

    Jensen-Clem, Rebecca; Duev, Dmitry A.; Riddle, Reed; Salama, Maïssa; Baranec, Christoph; Law, Nicholas M.; Kulkarni, S. R.; Ramprakash, A. N.

    2018-01-01

    Robo-AO is an autonomous laser guide star adaptive optics (AO) system recently commissioned at the Kitt Peak 2.1 m telescope. With the ability to observe every clear night, Robo-AO at the 2.1 m telescope is the first dedicated AO observatory. This paper presents the imaging performance of the AO system in its first 18 months of operations. For a median seeing value of 1.″44, the average Strehl ratio is 4% in the i\\prime band. After post processing, the contrast ratio under sub-arcsecond seeing for a 2≤slant i\\prime ≤slant 16 primary star is five and seven magnitudes at radial offsets of 0.″5 and 1.″0, respectively. The data processing and archiving pipelines run automatically at the end of each night. The first stage of the processing pipeline shifts and adds the rapid frame rate data using techniques optimized for different signal-to-noise ratios. The second “high-contrast” stage of the pipeline is eponymously well suited to finding faint stellar companions. Currently, a range of scientific programs, including the synthetic tracking of near-Earth asteroids, the binarity of stars in young clusters, and weather on solar system planets are being undertaken with Robo-AO.

  20. Energy Efficiency Improvement and Cost Saving Opportunities for Cement Making. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Worrell, Ernst; Galitsky, Christina

    2008-01-01

    The cost of energy as part of the total production costs in the cement industry is significant, warranting attention for energy efficiency to improve the bottom line. Historically, energy intensity has declined, although more recently energy intensity seems to have stabilized with the gains. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Most recently, there is a slight increase in the use of waste fuels, including tires. Between 1970 and 1999, primary physical energy intensity for cement production dropped 1 percent/year from 7.3 MBtu/short ton to 5.3 MBtu/short ton. Carbon dioxide intensity due to fuel consumption and raw material calcination dropped 16 percent, from 609 lb. C/ton of cement (0.31 tC/tonne) to 510 lb. C/ton cement (0.26 tC/tonne). Despite the historic progress, there is ample room for energy efficiency improvement. The relatively high share of wet-process plants (25 percent of clinker production in 1999 in the U.S.) suggests the existence of a considerable potential, when compared to other industrialized countries. We examined over 40 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. The report describes the measures and experiences of cement plants around the wold with these practices and technologies. Substantial potential for energy efficiency improvement exists in the cement industry and in individual plants. A portion of this potential will be achieved as part of (natural) modernization and expansion of existing facilities, as well as construction of new plants in particular regions. Still, a relatively large potential for improved energy management practices exists.

  1. Energy generation in convective shells of low mass, low metallicity stars

    International Nuclear Information System (INIS)

    Bazan, G.

    1989-01-01

    We report on the non-negligible energy generation from the 13 C neutron source and neutron capture reactions in low mass, low metallicity AGB stars. About 10 4 L circle-dot are generated within the thermal pulse convective shell by the combination of the 13 C(α, n) 16 O rate and the sum of the Y(Z,A)(n,γ)Y(Z,A + 1) reactions and beta decays. The inclusion of this energy source in an AGB thermal pulse evolution is shown to alter the evolution of the convective shell boundaries, and, hence, how the 13 C is ingested into the convective shell. Also, the duration of the pulse itself is reduced by the additional energy input. The nucleosynthetic consequences are discussed for these evolutionary changes. 17 refs., 5 figs

  2. Guide to energy efficiency opportunities in Canadian foundries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    In Canada, the foundry sector employs about 15000 people and most of the companies are members of the Canadian Foundry Association (CFA). The CFA is committed to reducing its greenhouse gas emissions and is therefore looking for energy savings which, in addition to reducing emissions, would help the industry save costs and improve its competitiveness. The aim of this document is to provide operators with a guide to improving energy efficiency in their foundries. The report provides guidance on carrying out energy audits, gathering energy saving ideas, prioritizing projects, and charting the course of improved energy performance. Many different energy saving ideas for many kinds of operation are presented in this guidebook as a help to operators in finding where they could improve their energy efficiency; references to energy saving methods from all over the world are provided. This guidebook is a useful tool for helping foundry operators improve energy efficiency in their operations.

  3. Measuring improvement in energy efficiency of the US cement industry with the ENERGY STAR Energy Performance Indicator

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, G.; Zhang, G. [Department of Economics, Duke University, Box 90097, Durham, NC 27708 (United States)

    2013-02-15

    The lack of a system for benchmarking industrial plant energy efficiency represents a major obstacle to improving efficiency. While estimates are sometimes available for specific technologies, the efficiency of one plant versus another could only be captured by benchmarking the energy efficiency of the whole plant and not by looking at its components. This paper presents an approach used by ENERGY STAR to implement manufacturing plant energy benchmarking for the cement industry. Using plant-level data and statistical analysis, we control for factors that influence energy use that are not efficiency, per se. What remains is an estimate of the distribution of energy use that is not accounted for by these factors, i.e., intra-plant energy efficiency. By comparing two separate analyses conducted at different points in time, we can see how this distribution has changed. While aggregate data can be used to estimate an average rate of improvement in terms of total industry energy use and production, such an estimate would be misleading as it may give the impression that all plants have made the same improvements. The picture that emerges from our plant-level statistical analysis is more subtle; the most energy-intensive plants have closed or been completely replaced and poor performing plants have made efficiency gains, reducing the gap between themselves and the top performers, whom have changed only slightly. Our estimate is a 13 % change in total source energy, equivalent to an annual reduction of 5.4 billion/kg of energy-related carbon dioxide emissions.

  4. Quantitative characterization of the reliability of simplex buses and stars to compare their benefits in fieldbuses

    International Nuclear Information System (INIS)

    Barranco, Manuel; Proenza, Julián; Almeida, Luís

    2015-01-01

    Fieldbuses targeted to highly dependable distributed embedded systems are shifting from bus to star topologies. Surprisingly, despite the efforts into this direction, engineers lack of analyses that quantitatively characterize the system reliability achievable by buses and stars. Thus, to guide engineers in developing adequate bus and star fieldbuses, this work models, quantifies and compares the system reliability provided by simplex buses and stars for the case of the Controller Area Network (CAN). It clarifies how relevant dependability-related aspects affect reliability, refuting some intuitive ideas, and revealing some previously unknown bus and star benefits. - Highlights: • SANs models that quantify the reliability of simplex buses/stars in fieldbuses. • Models cover system relevant dependability-related features abstracted in the literature. • Results refute intuitive ideas about buses and stars and show some unexpected effects. • Models and results can guide the design of reliable simplex bus/stars fieldbuses

  5. Guiding principles for energy policy in Schleswig-Holstein

    International Nuclear Information System (INIS)

    1982-01-01

    The principles of energy policy in Schleswig-Holstein set forward in this brochure are neither an energy programme nor a descriptive report on the policy of the day. Rather, they are intended to mark the energy-political frame of action within which the government of the Land will more. At the same time their purpose is to provide a medium-term orientation for politics and the power economy, consumers and producers. They are thus consciously made to contrast with political trends conceiving energy policy first of all as a plan-dependent activity. With these guiding principles the government of the Land consistantly continues an energy policy it has exposed in detail in its answer to the Question submitted by the CDU parliamentary party on December 8, 1980. (orig./UA) [de

  6. On the evolution of stars

    International Nuclear Information System (INIS)

    Kippenhahn, R.

    1989-01-01

    A popular survey is given of the present knowledge on evolution and ageing of stars. Main sequence stars, white dwarf stars, and red giant stars are classified in the Hertzsprung-Russell (HR)-diagram by measurable quantities: surface temperature and luminosity. From the HR-diagram it can be concluded to star mass and age. Star-forming processes in interstellar clouds as well as stellar burning processes are illustrated. The changes occurring in a star due to the depletion of the nuclear energy reserve are described. In this frame the phenomena of planetary nebulae, supernovae, pulsars, neutron stars as well as of black holes are explained

  7. Advanced Energy Design Guide K-12: Next Generation of School Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Torcellini, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pless, Shanti [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-01-01

    Driven by energy efficiency advances and renewable energy cost reductions, zero energy buildings are popping up all around the country. Although zero energy represents a bold paradigm shift - from buildings that consume energy to buildings that produce enough energy to meet their energy needs on an annual basis - it isn't a sudden shift. Zero energy buildings are the result of steady, incremental progress by researchers and building professionals working together to improve building energy performance. ASHRAE is taking the lead by publishing - in partnership with the American Institute of Architects (AIA), the Illuminating Engineering Society (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE) - a new series of advanced energy design guides (AEDGs) focused on zero energy buildings. The recently completed Advanced Energy Design Guide for K-12 School Buildings: Achieving Zero Energy (K-12 ZE AEDG) is the first in this series.

  8. Observing and Measuring Visual Double Stars

    CERN Document Server

    2013-01-01

    In these days of high-precision astrometric satellites, tremendous contributions to the science of astrometry are being made by amateur astronomers around the globe. This second edition of Observing and Measuring Visual Double Stars contains a significant amount of completely new material inspired by the work done by observers - particularly in the USA - since the first edition was published. Fifteen skilled and experienced astronomers have contributed chapters on their own specialization in the various fields. These include how to use the Internet to carry out precise astronomical measurement, an excellent guide to sketching double stars, and information on how to image double stars of unequal brightness. This new edition is the definitive book for those who are serious about this fascinating aspect of astronomy! Author Bob Argyle has been observing visual double stars for more than 40 years, some with the help of the world's biggest refractors, and has been director of the Webb Society Double Star Se...

  9. Best Practices Guide for Energy-Efficient Data Center Design

    Energy Technology Data Exchange (ETDEWEB)

    O. VanGeet: NREL

    2010-02-24

    This guide provides an overview of best practices for energy-efficient data center design which spans the categories of Information Technology (IT) systems and their environmental conditions, data center air management, cooling and electrical systems, on-site generation, and heat recovery.

  10. Prototype of a laser guide star wavefront sensor for the Extremely Large Telescope

    Science.gov (United States)

    Patti, M.; Lombini, M.; Schreiber, L.; Bregoli, G.; Arcidiacono, C.; Cosentino, G.; Diolaiti, E.; Foppiani, I.

    2018-06-01

    The new class of large telescopes, like the future Extremely Large Telescope (ELT), are designed to work with a laser guide star (LGS) tuned to a resonance of atmospheric sodium atoms. This wavefront sensing technique presents complex issues when applied to big telescopes for many reasons, mainly linked to the finite distance of the LGS, the launching angle, tip-tilt indetermination and focus anisoplanatism. The implementation of a laboratory prototype for the LGS wavefront sensor (WFS) at the beginning of the phase study of MAORY (Multi-conjugate Adaptive Optics Relay) for ELT first light has been indispensable in investigating specific mitigation strategies for the LGS WFS issues. This paper presents the test results of the LGS WFS prototype under different working conditions. The accuracy within which the LGS images are generated on the Shack-Hartmann WFS has been cross-checked with the MAORY simulation code. The experiments show the effect of noise on centroiding precision, the impact of LGS image truncation on wavefront sensing accuracy as well as the temporal evolution of the sodium density profile and LGS image under-sampling.

  11. Discriminating strange star mergers from neutron star mergers by gravitational-wave measurements

    International Nuclear Information System (INIS)

    Bauswein, A.; Oechslin, R.; Janka, H.-T.

    2010-01-01

    We perform three-dimensional relativistic hydrodynamical simulations of the coalescence of strange stars and explore the possibility to decide on the strange matter hypothesis by means of gravitational-wave measurements. Self-binding of strange quark matter and the generally more compact stars yield features that clearly distinguish strange star from neutron star mergers, e.g. hampering tidal disruption during the plunge of quark stars. Furthermore, instead of forming dilute halo structures around the remnant as in the case of neutron star mergers, the coalescence of strange stars results in a differentially rotating hypermassive object with a sharp surface layer surrounded by a geometrically thin, clumpy high-density strange quark matter disk. We also investigate the importance of including nonzero temperature equations of state in neutron star and strange star merger simulations. In both cases we find a crucial sensitivity of the dynamics and outcome of the coalescence to thermal effects, e.g. the outer remnant structure and the delay time of the dense remnant core to black hole collapse depend on the inclusion of nonzero temperature effects. For comparing and classifying the gravitational-wave signals, we use a number of characteristic quantities like the maximum frequency during inspiral or the dominant frequency of oscillations of the postmerger remnant. In general, these frequencies are higher for strange star mergers. Only for particular choices of the equation of state the frequencies of neutron star and strange star mergers are similar. In such cases additional features of the gravitational-wave luminosity spectrum like the ratio of energy emitted during the inspiral phase to the energy radiated away in the postmerger stage may help to discriminate coalescence events of the different types. If such characteristic quantities could be extracted from gravitational-wave signals, for instance with the upcoming gravitational-wave detectors, a decision on the

  12. Delta isobars in neutron stars

    Directory of Open Access Journals (Sweden)

    Pagliara Giuseppe

    2015-01-01

    Full Text Available The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.

  13. The Chemical Cosmos A Guided Tour

    CERN Document Server

    Miller, Steve

    2012-01-01

    If you have ever wondered how we get from the awesome impersonality of the Big Bang universe to the point where living creatures can start to form, and evolve into beings like you, your friends and your family, wonder no more. Steve Miller provides us with a tour through the chemical evolution of the universe, from the formation of the first molecules all the way to the chemicals required for life to evolve. Using a simple Hydrogen molecule – known as H-three-plus - as a guide, he takes us on a journey that starts with the birth of the first stars, and how, in dying, they pour their hearts out into enriching the universe in which we live. Our molecular guide makes its first appearance at the source of the Chemical Cosmos, at a time when only three elements and a total of 11 molecules existed. From those simple beginnings, H-three-plus guides us down river on the violent currents of exploding stars, through the streams of the Interstellar Medium, and into the delta where new stars and planets form. We are fi...

  14. Book Review: Stars (Copyright 1985, Golden Press; New York)

    Science.gov (United States)

    Marigza, R. N., Jr.

    2009-06-01

    Stars is a part of the Golden Guides collection produced by Golden Press. It is a small 160 page paperback guide to the constellations, the sun, the moon, planets, and other celestial bodies. The book is convenient to carry along wherever you go, making it an easy to access reference material.

  15. EVIDENCE OF SIGNIFICANT ENERGY INPUT IN THE LATE PHASE OF A SOLAR FLARE FROM NuSTAR X-RAY OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kuhar, Matej; Krucker, Säm [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland); Hannah, Iain G.; Wright, Paul J. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Glesener, Lindsay [School of Physics and Astronomy, University of Minnesota—Twin Cities, Minneapolis, MN 55455 (United States); Saint-Hilaire, Pascal; Hudson, Hugh S.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Grefenstette, Brian W.; Harrison, Fiona A. [Cahill Center for Astrophysics, 1216 E. California Boulevard, California Institute of Technology, Pasadena, CA 91125 (United States); White, Stephen M. [Air Force Research Laboratory, Albuquerque, NM (United States); Smith, David M.; Marsh, Andrew J. [Physics Department and Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2017-01-20

    We present observations of the occulted active region AR 12222 during the third Nuclear Spectroscopic Telescope ARray ( NuSTAR ) solar campaign on 2014 December 11, with concurrent Solar Dynamics Observatory ( SDO )/AIA and FOXSI-2 sounding rocket observations. The active region produced a medium-size solar flare 1 day before the observations, at ∼18 UT on 2014 December 10, with the post-flare loops still visible at the time of NuSTAR observations. The time evolution of the source emission in the SDO/ AIA 335 Å channel reveals the characteristics of an extreme-ultraviolet late-phase event, caused by the continuous formation of new post-flare loops that arch higher and higher in the solar corona. The spectral fitting of NuSTAR observations yields an isothermal source, with temperature 3.8–4.6 MK, emission measure (0.3–1.8) × 10{sup 46} cm{sup −3}, and density estimated at (2.5–6.0) × 10{sup 8} cm{sup −3}. The observed AIA fluxes are consistent with the derived NuSTAR temperature range, favoring temperature values in the range of 4.0–4.3 MK. By examining the post-flare loops’ cooling times and energy content, we estimate that at least 12 sets of post-flare loops were formed and subsequently cooled between the onset of the flare and NuSTAR observations, with their total thermal energy content an order of magnitude larger than the energy content at flare peak time. This indicates that the standard approach of using only the flare peak time to derive the total thermal energy content of a flare can lead to a large underestimation of its value.

  16. Kaon Condensation in Neutron Stars and High Density Behaviour of Nuclear Symmetry Energy

    International Nuclear Information System (INIS)

    Kubis, S.; Kutschera, M.

    1999-01-01

    We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaon-nucleon couplings at any density. There exists a threshold coupling above which the kaon condensate forms at densities exceeding some critical value. This is in contrast to the case of rising symmetry energy, as e.g. for relativistic mean field models, when the kaon condensate can form for any coupling at a sufficiently high density. Properties of the condensate are also different in both cases. (author)

  17. Kaon Condensation in Neutron Stars and High Density Behaviour of Nuclear Symmetry Energy

    International Nuclear Information System (INIS)

    Kubis, S.; Kutschera, M.

    1999-04-01

    We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaon-nucleon couplings at any density. There exists a threshold coupling above which the kaon condensate forms at densities exceeding some critical value. This is in contrast to the case of rising symmetry energy, as e.g. for relativistic mean field models, when the kaon condensate can form for any coupling at a sufficiently high density. Properties of the condensate are also different in both cases

  18. Star-forming galaxy models: Blending star formation into TREESPH

    Science.gov (United States)

    Mihos, J. Christopher; Hernquist, Lars

    1994-01-01

    We have incorporated star-formation algorithms into a hybrid N-body/smoothed particle hydrodynamics code (TREESPH) in order to describe the star forming properties of disk galaxies over timescales of a few billion years. The models employ a Schmidt law of index n approximately 1.5 to calculate star-formation rates, and explicitly include the energy and metallicity feedback into the Interstellar Medium (ISM). Modeling the newly formed stellar population is achieved through the use of hybrid SPH/young star particles which gradually convert from gaseous to collisionless particles, avoiding the computational difficulties involved in creating new particles. The models are shown to reproduce well the star-forming properties of disk galaxies, such as the morphology, rate of star formation, and evolution of the global star-formation rate and disk gas content. As an example of the technique, we model an encounter between a disk galaxy and a small companion which gives rise to a ring galaxy reminiscent of the Cartwheel (AM 0035-35). The primary galaxy in this encounter experiences two phases of star forming activity: an initial period during the expansion of the ring, and a delayed phase as shocked material in the ring falls back into the central regions.

  19. Dynamical Boson Stars

    Directory of Open Access Journals (Sweden)

    Steven L. Liebling

    2012-05-01

    Full Text Available The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.

  20. Prediction of Wind Energy Resources (PoWER) Users Guide

    Science.gov (United States)

    2016-01-01

    ARL-TR-7573● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER) User’s Guide by David P Sauter...manufacturer’s or trade names does not constitute an official endorsement or approval of the use thereof. Destroy this report when it is no longer needed. Do...not return it to the originator. ARL-TR-7573 ● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER

  1. Gravitational instability, evolution of galaxies and star formation

    International Nuclear Information System (INIS)

    Palous, J.

    1979-01-01

    The gravitational collapse is the key to the theories of galaxy and star formation. The observations, showing intrinsic differences between elliptical and spiral galaxies, guide our fundamental conceptions on the formation and evolution of systems in question. Stars in elliptical galaxies and in spherical components of spiral galaxies were formed in a short period of time during early phases of protogalactic collapse, at a time of violent star formation. The disc-like components of spiral galaxies, however, were built gradually in the course of galactic evolution. Star formation in elliptical galaxies is described by the collision model of interstellar clouds, while star formation in discs is characterised by several processes: the expansion of HII regions, the expansion of supernovae remnants and the shock wave related to the presence of the spiral structure. (author)

  2. Six policy actions for accelerated deployment of renewable energy. READy Renewable Energy Action on Deployment. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-03-15

    The READy book presents a kaleidoscope of policy options that have proven to accelerate the deployment of renewable energy technologies, based on experiences around the world at the local and national levels. Lessons learned from successful cases are distilled into six essential action points. Together these categories of policy actions compose the ACTION Star, a guide for taking action now while preparing for growth over the long term.

  3. On the structure of critical energy levels for the cubic focusing NLS on star graphs

    International Nuclear Information System (INIS)

    Adami, Riccardo; Noja, Diego; Cacciapuoti, Claudio; Finco, Domenico

    2012-01-01

    We provide information on a non-trivial structure of phase space of the cubic nonlinear Schrödinger (NLS) on a three-edge star graph. We prove that, in contrast to the case of the standard NLS on the line, the energy associated with the cubic focusing Schrödinger equation on the three-edge star graph with a free (Kirchhoff) vertex does not attain a minimum value on any sphere of constant L 2 -norm. We moreover show that the only stationary state with prescribed L 2 -norm is indeed a saddle point. (fast track communication)

  4. The mysterious SU UMa stars

    International Nuclear Information System (INIS)

    Charles, P.A.

    1990-01-01

    This paper discusses the characteristics and the source of energy of the explosive stars called cataclysmic variables (CVs), with special attention given to the SU UMa stars, which represent CVs which have disks. In SU UMa binaries, a gas stream from a cool reddish star hits an accretion disk spiraling around a white dwarf. The impact of the stream produces a bright 'hot spot' on the edge of the disk, seen only when the system is quiescent and the disk is relatively dim (during outbursts, the hot spot is swamped by the light of the disk itself). The principal source of energy and light of most CVs is the gravitational potential energy released by matter falling from the dim reddish companion onto the white dwarf. The mechanism involved in the overflow of the reddish star is believed to be magnetic braking. Simulations are presented that explain the SU UMa phenomena and which may be applicable to other high-mass-ratio interacting binaries

  5. Technical Support Document: Development of the Advanced Energy Design Guide for Small Office Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Jarnagin, Ronald E.; Liu, Bing; Winiarski, David W.; McBride, Merle F.; Suharli, L.; Walden, D.

    2006-11-30

    This Technical Support Document (TSD) describes the process and methodology for the development of the Advanced Energy Design Guide for Small Office Buildings (AEDG-SO), a design guidance document intended to provide recommendations for achieving 30% energy savings in small office buildings over levels contained in ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings. The AEDG-SO is the first in a series of guides being developed by a partnership of organizations, including the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IESNA), the New Buildings Institute (NBI), and the U.S. Department of Energy (DOE). Each of the guides in the AEDG series will provide recommendations and user-friendly design assistance to designers, developers and owners of small commercial buildings that will encourage steady progress towards net-zero energy buildings. The guides will provide prescriptive recommendation packages that are capable of reaching the energy savings target for each climate zone in order to ease the burden of the design and construction of energy-efficient small commercial buildings The AEDG-SO was developed by an ASHRAE Special Project committee (SP-102) made up of representatives of each of the partner organizations in eight months. This TSD describes the charge given to the committee in developing the office guide and outlines the schedule of the development effort. The project committee developed two prototype office buildings (5,000 ft2 frame building and 20,000 ft2 two-story mass building) to represent the class of small office buildings and performed an energy simulation scoping study to determine the preliminary levels of efficiency necessary to meet the energy savings target. The simulation approach used by the project committee is documented in this TSD along with

  6. Technical Support Document: The Development of the Advanced Energy Design Guide for Highway Lodging Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Wei; Jarnagin, Ronald E.; Gowri, Krishnan; McBride, M.; Liu, Bing

    2008-09-30

    This Technical Support Document (TSD) describes the process and methodology for development of the Advanced Energy Design Guide for Highway Lodgings (AEDG-HL or the Guide), a design guidance document intended to provide recommendations for achieving 30% energy savings in highway lodging properties over levels contained in ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings. The AEDG-HL is the fifth in a series of guides being developed by a partnership of organizations, including the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IESNA), the United States Green Buildings Council (USGBC), and the U.S. Department of Energy (DOE).

  7. Energy Renovations: Volume 17: Insulation - A Guide for Contractors to Share with Homeowners

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Michael C.; Adams, Karen; Hefty, Marye G.; Gilbride, Theresa L.; Love, Pat M.

    2012-05-15

    This report was prepared by PNNL for DOE's Building America program and is intended as a guide that energy performance contractors can share with homeowners to describe various insulation options for improving the energy performance and comfort of existing homes. The report provides descriptions of many common insulation types, including their advantages and disadvantages, R-values, characteristics, and typical uses. The report also describes potentially hazardous products such as asbestos and formaldehyde and safety issues when conducting energy-efficient upgrades including radon. The guide is available for download at the DOE Building America website, www.buildingamerica.gov.

  8. Stability properties of Q-stars

    International Nuclear Information System (INIS)

    Becerril, R.; Bernal, A.; Guzman, F.S.; Nucamendi, U.

    2007-01-01

    We present the evolution of Q-star configurations using numerical methods. We solve the full Einstein-Klein-Gordon system of equations and show that: Q-stars can be stable and unstable. The unstable branch is two fold: configurations with negative binding energy that collapse and form black holes, and others with positive binding energy that explode and release the scalar field

  9. Imprints of the nuclear symmetry energy on gravitational waves from the axial w-modes of neutron stars

    International Nuclear Information System (INIS)

    Wen Dehua; Li Baoan; Krastev, Plamen G.

    2009-01-01

    The eigenfrequencies of the axial w-modes of oscillating neutron stars are studied using the continued fraction method with an equation of state (EOS) partially constrained by the recent terrestrial nuclear laboratory data. It is shown that the density dependence of the nuclear symmetry energy E sym (ρ) affects significantly both the frequencies and the damping times of these modes. Besides confirming the previously found universal behavior of the mass-scaled eigenfrequencies as functions of the compactness of neutron stars, we explored several alternative universal scaling functions. Moreover, the w II -mode is found to exist only for neutron stars having a compactness of M/R≥0.1078 independent of the EOS used.

  10. Spectrophotometry of carbon stars

    International Nuclear Information System (INIS)

    Gow, C.E.

    1975-01-01

    Observations of over one hundred carbon stars have been made with the Indiana rapid spectral scanner in the red and, when possible, in the visual and blue regions of the spectrum. Five distinct subtypes of carbon stars (Barium, CH, R, N, and hydrogen deficient) are represented in the list of observed stars, although the emphasis was placed on the N stars when the observations were made. The rapid scanner was operated in the continuous sweep mode with the exit slit set at twenty angstroms, however, seeing fluctuations and guiding errors smear the spectrum to an effective resolution of approximately thirty angstroms. Nightly observations of Hayes standard stars yielded corrections for atmospheric extinction and instrumental response. The reduction scheme rests on two assumptions, that thin clouds are gray absorbers and the wavelength dependence of the sky transparency does not change during the course of the night. Several stars have been observed in the blue region of the spectrum with the Indiana SIT vidicon spectrometer at two angstroms resolution. It is possible to derive a color temperature for the yellow--red spectral region by fitting a black-body curve through two chosen continuum points. Photometric indices were calculated relative to the blackbody curve to measure the C 2 Swan band strength, the shape of the CN red (6,1) band to provide a measure of the 12 C/ 13 C isotope ratio, and in the hot carbon stars (Barium, CH, and R stars) the strength of an unidentified feature centered at 400 angstroms. An extensive abundance grid of model atmospheres was calculated using a modified version of the computer code ATLAS

  11. ENERGY STAR® Retail Products Platform (RPP): Conditions and Considerations in Evaluating Market Transformation Programs and Evaluation Guidance for RPP

    Energy Technology Data Exchange (ETDEWEB)

    Li, Michael [U.S. Department of Energy; Banwell, Peter [U.S. Environmental Protection Agency

    2018-01-09

    The purpose of this guide is to provide a resource for state utility regulators, utilities, the evaluation community and regulatory stakeholders on methods to measure energy savings from the ENERGY STAR Retail Products Platform (link is external). The guidelines outlined in this document were developed by evaluation experts.

  12. Analysis of Illinois Home Performance with ENERGY STAR(R) Measure Packages

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.; Yee, S.; Brand, L.

    2013-09-01

    Through the Chicagoland Single Family Housing Characterization and Retrofit Prioritization report, the Partnership for Advanced Residential Retrofit characterized 15 housing types in the Chicagoland region based on assessor data, utility billing history, and available data from prior energy efficiency programs. Within these 15 groups, a subset showed the greatest opportunity for energy savings based on BEopt Version 1.1 modeling of potential energy efficiency package options and the percent of the housing stock represented by each group. In this project, collected field data from a whole-home program in Illinois are utilized to compare marketplace-installed measures to the energy saving optimal packages previously developed for the 15 housing types. Housing type, conditions, energy efficiency measures installed, and retrofit cost information were collected from 19 homes that participated in the Illinois Home Performance with ENERGY STAR program in 2012, representing eight of the characterized housing groups. Two were selected for further case study analysis to provide an illustration of the differences between optimal and actually installed measures. Taken together, these homes are representative of 34.8% of the Chicagoland residential building stock. In one instance, actual installed measures closely matched optimal recommended measures.

  13. Energy Flows in Low-Entropy Complex Systems

    Directory of Open Access Journals (Sweden)

    Eric J. Chaisson

    2015-12-01

    Full Text Available Nature’s many complex systems—physical, biological, and cultural—are islands of low-entropy order within increasingly disordered seas of surrounding, high-entropy chaos. Energy is a principal facilitator of the rising complexity of all such systems in the expanding Universe, including galaxies, stars, planets, life, society, and machines. A large amount of empirical evidence—relating neither entropy nor information, rather energy—suggests that an underlying simplicity guides the emergence and growth of complexity among many known, highly varied systems in the 14-billion-year-old Universe, from big bang to humankind. Energy flows are as centrally important to life and society as they are to stars and galaxies. In particular, the quantity energy rate density—the rate of energy flow per unit mass—can be used to explicate in a consistent, uniform, and unifying way a huge collection of diverse complex systems observed throughout Nature. Operationally, those systems able to utilize optimal amounts of energy tend to survive and those that cannot are non-randomly eliminated.

  14. Experimental study on ultrasound-guided intratumoral injection of "Star-99" in treatment of hepatocellular carcinoma of nude mice

    Institute of Scientific and Technical Information of China (English)

    Li-Wu Lin; Xiao-Dong Lin; Yi-Mi He; Shang-Da Gao; En-Sheng Xue

    2003-01-01

    AIM: To investigate the anti-cancer effect and the immunological mechanism of ultrasound-guided intratumoral injection of Chinese medicine "Star-99" in hepatocellular carcinoma (HCC) of nude mice.METHODS: Twenty-eight human hepatocellular carcinoma SMMC-7721 transplanted nude mice, 14 of hypodermically implanted and 14 of orthotopic liver transplanted, were randomly divided into three groups of which 14 mice with Star-99, and 7 with ethanol and saline respectively. Ten days after the transplantation the medicines were injected into the tumors of all the nude mice once every 5 days.After 4 injections the nude mice were killed. The diameters of three dimension of the tumors were measured by high frequency ultrasound before and after the treatment and the tumor growth indexes* (TGI) were calculated.Radioimmunoassay was used to detect the serum levels of interleukin-2 (IL-2) and tumor necrosis factor (TNF)-alpha.The tumor tissues were sent for flow cytometry (FCM) DNA analysis. Apoptotic cells were visualized by TUNEL assay.All the experiments were carried out by double blind method. zRESULTS: The TGI of Star-99 group (0.076±0.024) was markedly lower than that of the saline group (4.654±1.283)(P<0.01). It also seemed to be lower than that of the ethanol group (0.082±0.028), but not significantly different (P>0.05).Serum levels of IL-2 and TNF-α were markedly higher than those of ethanol group and saline groups (P<0.05). The mean apoptotic index (AI: percentage of TUNEL signal positive cells)in Star-99 group (48.98±5.09 %) was significantly higher than that of the ethanol group (11.95±2.24 %) and the saline group (10.48±3.85 %) (P<0.01). FCM DNA analysis showed that the appearance rate of the apoptosis peak in Srar-99group was 92.9 %, markedly higher than that of the ethanol group (14.3 %) and the saline group (0.0 %) (P<0.01).Correlation (r=0.499, P<0.05) was found between AI and serum level of TNF-α.CONCLUSION: Star-99 has an effect on the

  15. Urban energy management: a course on the administration of public energy programs. An instructor's guide

    Energy Technology Data Exchange (ETDEWEB)

    Mandelbaum, Dr., Len; Olsen, Dr., Marvin; Hyman, Dr., Barry; Sheridan, Mimi; Dahlberg, Judy; O' Brien, Jeremy

    1980-12-01

    The course provides local government administrators, staff, and students with the background knowledge to deal with a broad range of energy management concerns and is not to train technical energy conservation specialists. Section II contains the Instructor's Guide and Section III provides the Student Outlines and Handouts on the following subjects: The Energy Problem; National Energy Politics and Programs; State and Local Energy Programs; Techniques of Energy Planning; Techniques of Energy Conservation; Techniques of Renewable Energy Production; Strategies for Voluntary Energy Management; Strategies for Finan. Energy Management; and Strategies for Mandatory Energy Management. (MCW)

  16. High-energy emission from star-forming galaxies

    International Nuclear Information System (INIS)

    Persic, M.; Rephaeli, Y.

    2011-01-01

    Adopting the convection-diffusion model for energetic electron and proton propagation, and accounting for al lthe relevant hadronic and leptonic processes, the steady-state energy distributions of these particles in the starburst galaxies M 82 and NGC 253 can be determined with a detailed numerical treatment. The electron distribution is directly normalized by the measured synchrotron radioemission from the central starburst region; a commonly expected theoretical relationis then used to normalize the proton spectrum in thisr egion, and a radial profile is assumed for the magnetic field. The resulting radiative yields of electrons and protons are calculated: thepredicted > 100MeV and > 100GeV fluxes are in agreement with the corresponding quantities measured with the orbiting Fermite lescope and the ground-based VERITAS and HESS Cherenkov telescopes. The cosmic-rayenergy densities in central regions of starburst galaxies, as inferred from the radioand γ-ray measurements of (respectively) non-thermal synchrotron and π 0 -decay emission, are U p = O(100)eVcm -3 , i.e. at least an order of magnitude larger than near the Galactic center and in other non-very-actively star-forming galaxies. These very different energy density levelsr eflect a similar disparity in the respective supernova rates in the two environments. A L γ proper to SFR 1.4 relationship is then predicted, in agreement with preliminary observational evidence.

  17. Spectrophotometric observations of symbiotic stars

    International Nuclear Information System (INIS)

    Ipatov, A.P.; Yudin, B.F.

    1985-01-01

    The data of spectrophotometric observations of symbiotic stars Z And, AX Per, CI Cyg, BF Cyg, YY Her, V 443 Her, AG Dra, AG Peg, AS 296, EG And, V 1016 Cyg, and HM Sge are presented. The spectral range of observations is 3300-7500 A, resolution is 50 A. The data obtained allowed to reveal specific characteristics inherent to the radiation of symbiotic stars and to estimate the parameters of their individual components. Analysis of the spectra of symbiotic stars in the range of 1300-7500 A wavelengths suggests a hypothesis, according to which a hot source in the Rayleigh - Jeans spectral range has a less steep inclination in the energy distribution, than a black-body one. A disk, formed during cold star substance accretion through an internal Lagrangian point onto a denser component of the system, can play the role of the source. In this case one manages to obtain the energy distribution in the symbiotic star spectrum consistent with the observed distribution

  18. Space-Based Astronomy: An Educator Guide with Activities for Science, Mathematics, and Technology Education

    Science.gov (United States)

    Vogt, Gregory L.

    2001-01-01

    If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.

  19. ELECTROMAGNETIC EXTRACTION OF ENERGY FROM BLACK-HOLE–NEUTRON-STAR BINARIES

    International Nuclear Information System (INIS)

    McWilliams, Sean T.; Levin, Janna

    2011-01-01

    The coalescence of black-hole-neutron-star binaries is expected to be a principal source of gravitational waves for the next generation of detectors, Advanced LIGO and Advanced Virgo. For black hole masses not much larger than the neutron star mass, the tidal disruption of the neutron star by the black hole provides one avenue for generating an electromagnetic counterpart. However, in this work, we demonstrate that, for all black-hole-neutron-star binaries observable by Advanced LIGO/Virgo, the interaction of the black hole with the magnetic field of the neutron star will generate copious luminosity, comparable to supernovae and active galactic nuclei. This novel effect may have already been observed as a new class of very short gamma-ray bursts by the Swift Gamma-Ray Burst Telescope. These events may be observable to cosmological distances, so that any black-hole-neutron-star coalescence detectable with gravitational waves by Advanced LIGO/Virgo could also be detectable electromagnetically.

  20. Home Performance with ENERGY STAR: Utility Bill Analysis on Homes Participating in Austin Energy's Program

    Energy Technology Data Exchange (ETDEWEB)

    Belzer, D.; Mosey, G.; Plympton, P.; Dagher, L.

    2007-07-01

    Home Performance with ENERGY STAR (HPwES) is a jointly managed program of the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA). This program focuses on improving energy efficiency in existing homes via a whole-house approach to assessing and improving a home's energy performance, and helping to protect the environment. As one of HPwES's local sponsors, Austin Energy's HPwES program offers a complete home energy analysis and a list of recommendations for efficiency improvements, along with cost estimates. To determine the benefits of this program, the National Renewable Energy Laboratory (NREL) collaborated with the Pacific Northwest National Laboratory (PNNL) to conduct a statistical analysis using energy consumption data of HPwES homes provided by Austin Energy. This report provides preliminary estimates of average savings per home from the HPwES Loan Program for the period 1998 through 2006. The results from this preliminary analysis suggest that the HPwES program sponsored by Austin Energy had a very significant impact on reducing average cooling electricity for participating households. Overall, average savings were in the range of 25%-35%, and appear to be robust under various criteria for the number of households included in the analysis.

  1. Evolution of star systems supplied by external stars: a model for Galaxy nuclei

    International Nuclear Information System (INIS)

    Dokuchaev, V.I.; Ozernoj, L.M.; AN SSSR, Moscow. Inst. Yadernykh Issledovanij)

    1985-01-01

    Extended rarefied environments around the core of a non-isothermic galaxy nucleus can supply the core by both energies and masses of external stars due to relaxation mechanisms. These factors can influence considerably the secular evolution of the core when competing with usual star evaporation from it. Conditions are found under which external environments influence the core evolution much more than star evaporation. This results in expansion of the core instead of its collapse

  2. Spectrophotometry of peculiar B and A stars. II. Eleven mercury-manganese stars

    International Nuclear Information System (INIS)

    Adelman, S.J.; Pyper, D.M.

    1979-01-01

    Spectrophotometry of eleven HgMn stars is presented for the optical region. As found in Paper I, the HgMn stars have systematically larger Δiota* and Δa values than the normal main sequence stars due to differences with respect to the mean continuum particularly of the lambda4464 values and the lambda5200 region, respectively. The HgMn stars exhibit a continuous range in the behavior of both the lambda4200 and lambda5200 regions between those stars that have index values larger than the appropriate criterion of presence and present definite evidence for the features to those stars with only a slight possibility of such features. The strengths of the lambda4200 and lambda5200 features appear not to be correlated. In the HgMn stars, both features may be due to differential line blocking. In the energy distribution of all eleven stars, the Balmer jump regions best fit the predictions of slightly hotter solar composition, log g=4.0, fully line blanketed model atmospheres than do the corresponding Paschen continua

  3. 2015 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2014-01-01

    Compact, easy to use and reliable, this popular guide has been providing star gazers with everything they need to know about the southern night sky for the past 25 years. The 2015 guide will celebrate this landmark with highlights from the past as well as monthly astronomy maps, viewing tips and highlights, and details of the year's exciting celestial events.Wherever you are in Australia or New Zealand, easy calculations allow you to estimate local rise and set times for the Sun, Moon and planets. The 2015 Australasian Sky Guide also provides information on the solar system, updated with the l

  4. Energy flux due to electromagnetic fluctuations during guide field magnetic reconnection

    International Nuclear Information System (INIS)

    Kuwahata, Akihiro; Inomoto, Michiaki; Ono, Yasushi; Yanai, Ryoma

    2016-01-01

    Large electromagnetic fluctuations inside the current sheet and large reconnection electric fields are observed during fast magnetic reconnection in the presence of a guide field. The fluctuations transport 2.5% of the dissipated magnetic energy from the reconnection region. Although the energy gains of the ions and electrons are approximately 60% and 12%, respectively, of the dissipated magnetic energy after the fast reconnection, the energy of fluctuations is not comparable to their energy gains. The fluctuations do not directly contribute to the energy conversion but might cause the fast reconnection leading to the rapid release of magnetic energy. (author)

  5. Constraints on the symmetry energy from observational probes of the neutron star crust

    International Nuclear Information System (INIS)

    Newton, William G.; Hooker, Joshua; Gearheart, Michael; Fattoyev, Farrukh J.; Li, Bao-An; Murphy, Kyleah; Wen, De-Hua

    2014-01-01

    A number of observed phenomena associated with individual neutron star systems or neutron star populations find explanations in models in which the neutron star crust plays an important role. We review recent work examining the sensitivity to the slope of the symmetry energy L of such models, and constraints extracted on L from confronting them with observations. We focus on six sets of observations and proposed explanations: (i) The cooling rate of the neutron star in Cassiopeia A, confronting cooling models which include enhanced cooling in the nuclear pasta regions of the inner crust; (ii) the upper limit of the observed periods of young X-ray pulsars, confronting models of magnetic field decay in the crust caused by the high resistivity of the nuclear pasta layer; (iii) glitches from the Vela pulsar, confronting the paradigm that they arise due to a sudden recoupling of the crustal neutron superfluid to the crustal lattice after a period during which they were decoupled due to vortex pinning; (iv) the frequencies of quasi-periodic oscillations in the X-ray tail of light curves from giant flares from soft gamma-ray repeaters, confronting models of torsional crust oscillations; (v) the upper limit on the frequency to which millisecond pulsars can be spun-up due to accretion from a binary companion, confronting models of the r-mode instability arising above a threshold frequency determined in part by the viscous dissipation timescale at the crust-core boundary; and (vi) the observations of precursor electromagnetic flares a few seconds before short gamma-ray bursts, confronting a model of crust shattering caused by resonant excitation of a crustal oscillation mode by the tidal gravitational field of a companion neutron star just before merger. (orig.)

  6. Constraints on the symmetry energy from observational probes of the neutron star crust

    Energy Technology Data Exchange (ETDEWEB)

    Newton, William G.; Hooker, Joshua; Gearheart, Michael; Fattoyev, Farrukh J.; Li, Bao-An [Texas A and M University-Commerce, Department of Physics and Astronomy, Commerce (United States); Murphy, Kyleah [Texas A and M University-Commerce, Department of Physics and Astronomy, Commerce (United States); Umpqua Community College, Roseburg, Oregon (United States); Wen, De-Hua [Texas A and M University-Commerce, Department of Physics and Astronomy, Commerce (United States); South China University of Technology, Department of Physics, Guangzhou (China)

    2014-02-15

    A number of observed phenomena associated with individual neutron star systems or neutron star populations find explanations in models in which the neutron star crust plays an important role. We review recent work examining the sensitivity to the slope of the symmetry energy L of such models, and constraints extracted on L from confronting them with observations. We focus on six sets of observations and proposed explanations: (i) The cooling rate of the neutron star in Cassiopeia A, confronting cooling models which include enhanced cooling in the nuclear pasta regions of the inner crust; (ii) the upper limit of the observed periods of young X-ray pulsars, confronting models of magnetic field decay in the crust caused by the high resistivity of the nuclear pasta layer; (iii) glitches from the Vela pulsar, confronting the paradigm that they arise due to a sudden recoupling of the crustal neutron superfluid to the crustal lattice after a period during which they were decoupled due to vortex pinning; (iv) the frequencies of quasi-periodic oscillations in the X-ray tail of light curves from giant flares from soft gamma-ray repeaters, confronting models of torsional crust oscillations; (v) the upper limit on the frequency to which millisecond pulsars can be spun-up due to accretion from a binary companion, confronting models of the r-mode instability arising above a threshold frequency determined in part by the viscous dissipation timescale at the crust-core boundary; and (vi) the observations of precursor electromagnetic flares a few seconds before short gamma-ray bursts, confronting a model of crust shattering caused by resonant excitation of a crustal oscillation mode by the tidal gravitational field of a companion neutron star just before merger. (orig.)

  7. Energy Efficiency Improvement and Cost Saving Opportunities for the Vehicle Assembly Industry: An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Galitsky, Christina; Worrell, Ernst

    2008-01-01

    The motor vehicle industry in the U.S. spends about $3.6 billion on energy annually. In this report, we focus on auto assembly plants. In the U.S., over 70 assembly plants currently produce 13 million cars and trucks each year. In assembly plants, energy expenditures is a relatively small cost factor in the total production process. Still, as manufacturers face an increasingly competitive environment, energy efficiency improvements can provide a means to reduce costs without negatively affecting the yield or the quality of the product. In addition, reducing energy costs reduces the unpredictability associated with variable energy prices in today?s marketplace, which could negatively affect predictable earnings, an important element for publicly-traded companies such as those in the motor vehicle industry. In this report, we first present a summary of the motor vehicle assembly process and energy use. This is followed by a discussion of energy efficiency opportunities available for assembly plants. Where available, we provide specific primary energy savings for each energy efficiency measure based on case studies, as well as references to technical literature. If available, we have listed costs and typical payback periods. We include experiences of assembly plants worldwide with energy efficiency measures reviewed in the report. Our findings suggest that although most motor vehicle companies in the U.S. have energy management teams or programs, there are still opportunities available at individual plants to reduce energy consumption cost effectively. Further research on the economics of the measures for individual assembly plants, as part of an energy management program, is needed to assess the potential impact of selected technologies at these plants.

  8. High energy neutrinos from the tidal disruption of stars

    Energy Technology Data Exchange (ETDEWEB)

    Lunardini, Cecilia [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Winter, Walter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2017-05-17

    We study the production of high energy neutrinos in jets from the tidal disruption of stars by supermassive black holes. The diffuse neutrino flux expected from these tidal disruption events (TDEs) is calculated both analytically and numerically, taking account the dependence of the rate of TDEs on the redshift and black hole mass. We find that ∝ 10% of the observed diffuse flux at IceCube at an energy of about 1 PeV can come from TDEs if the characteristics of known jetted tidal disruption events are assumed to apply to the whole population of these sources. If, however, plausible scalings of the jet Lorentz factor or variability timescale with the black hole mass are taken into account, the contribution of the lowest mass black holes to the neutrino flux is enhanced. In this case, TDEs can account for most of the neutrino flux detected at IceCube, describing both the neutrino flux normalization and spectral shape with moderate baryonic loadings. While the uncertainties on our assumptions are large, a possible signature of TDEs as the origin of the IceCube signal is the transition of the flux flavor composition from a pion beam to a muon damped source at the highest energies, which will also result in a suppression of Glashow resonance events.

  9. High energy neutrinos from the tidal disruption of stars

    International Nuclear Information System (INIS)

    Lunardini, Cecilia

    2017-01-01

    We study the production of high energy neutrinos in jets from the tidal disruption of stars by supermassive black holes. The diffuse neutrino flux expected from these tidal disruption events (TDEs) is calculated both analytically and numerically, taking account the dependence of the rate of TDEs on the redshift and black hole mass. We find that ∝ 10% of the observed diffuse flux at IceCube at an energy of about 1 PeV can come from TDEs if the characteristics of known jetted tidal disruption events are assumed to apply to the whole population of these sources. If, however, plausible scalings of the jet Lorentz factor or variability timescale with the black hole mass are taken into account, the contribution of the lowest mass black holes to the neutrino flux is enhanced. In this case, TDEs can account for most of the neutrino flux detected at IceCube, describing both the neutrino flux normalization and spectral shape with moderate baryonic loadings. While the uncertainties on our assumptions are large, a possible signature of TDEs as the origin of the IceCube signal is the transition of the flux flavor composition from a pion beam to a muon damped source at the highest energies, which will also result in a suppression of Glashow resonance events.

  10. Transverse energy measurement in Au + Au collisions by the STAR experiment

    International Nuclear Information System (INIS)

    Sahoo, R.

    2011-01-01

    Transverse energy (E T ) has been measured with both of its components, namely hadronic (E T had ) and electromagnetic (E T em ) in a common phase space at mid-rapidity for 62.4 GeV Au+Au collisions by the STAR experiment. E T production with centrality and √S NN is studied with similar measurements from SPS to RHIC and is compared with a final state gluon saturation model (EKRT). The most striking feature is the observation of a nearly constant value of E T /N ch ∼ 0.8 GeV from AGS, SPS to RHIC. The initial energy density estimated by the boost-invariant Bjorken hydrodynamic model, is well above the critical density for a deconfined matter of quarks and gluons predicted by lattice QCD calculations. (author)

  11. Energy Dissipation and Dynamics in Large Guide Field Turbulence Driven Reconnection at the Magnetopause

    Science.gov (United States)

    TenBarge, J. M.; Shay, M. A.; Sharma, P.; Juno, J.; Haggerty, C. C.; Drake, J. F.; Bhattacharjee, A.; Hakim, A.

    2017-12-01

    Turbulence and magnetic reconnection are the primary mechanisms responsible for the conversion of stored magnetic energy into particle energy in many space and astrophysical plasmas. The magnetospheric multiscale mission (MMS) has given us unprecedented access to high cadence particle and field data of turbulence and magnetic reconnection at earth's magnetopause. The observations include large guide field reconnection events generated within the turbulent magnetopause. Motivated by these observations, we present a study of large guide reconnection using the fully kinetic Eulerian Vlasov-Maxwell component of the Gkeyll simulation framework, and we also employ and compare with gyrokinetics to explore the asymptotically large guide field limit. In addition to studying the configuration space dynamics, we leverage the recently developed field-particle correlations to diagnose the dominant sources of dissipation and compare the results of the field-particle correlation to other energy dissipation measures.

  12. Vanguard Preparatory School Observations of the Double Star STF 1692

    Science.gov (United States)

    Anderson, Serenity; Buccola, Breck; Garcia, Karen; Gosney, Matthew; Housatchenko, Jonathan; Martinez, Lilian; Myskow, Wyatt; Renteria, Noah; Schlosser, Ruth; Thompson, Leone; Estrada, Reed; Estrada, Chris

    2016-01-01

    Using a 22-inch Newtonian Alt/Az telescope and a Celestron Micro Guide eyepiece, students from Vanguard Preparatory observed the binary star Cor Caroli (STF 1692) and found a position angle of 228 degrees as well as an average separation of 21.10". This project was a part of the Vanguard Preparatory Double Star Workshop 2015 in Apple Valley, California.

  13. Development of the Advanced Energy Design Guide for K-12 Schools -- 50% Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, E.; Leach, M.; Pless, S.; Torcellini, P.

    2013-02-01

    This Technical Support Document (TSD) describes the process and methodology for the development of the Advanced Energy Design Guide for K-12 School Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-K12) (ASHRAE et al. 2011a). The AEDG-K12 provides recommendations for achieving 50% whole-building energy savings in K-12 schools over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-K12 was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE).

  14. The stargazer's guide to the night sky

    CERN Document Server

    Lisle, Jason, Dr

    2012-01-01

    Explore the night sky, identify stars, constellations, and even planets. Stargaze with a telescope, binoculars, or even your naked eye. Allow Dr. Jason Lisle, a research scientist with a masters and PhD in astrophysics, to guide you in examining the beauty of God's Creation with 150 full color star-charts. Learn the best ways and optimal times to observe planets and stars with easy to use illustrations. Create or expand the hobby of stargazing; an outdoor, educational hobby to enjoy with friends or family.

  15. The spectrophotometric investigation of 4 parent stars

    International Nuclear Information System (INIS)

    Tereshchenko, V.M.

    2005-01-01

    The absolute energy distribution in spectra of four parent stars was obtained. The synthetic color indexes for the investigated stars were calculated. They were used for determination of the fundamental parameters of the parent stars: effective temperatures and metallicities. (author)

  16. Energy Guiding and Harvesting through Phonon-Engineered Graphene

    Science.gov (United States)

    2016-01-28

    Graphene The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official Department of the...ABSTRACT Final Report: Energy Guiding and Harvesting through Phonon-Engineered Graphene Report Title The work performed under this proposal was primarily...Justin Wu, Xinran Wang, Kristof Tahy, Debdeep Jena, Hongjie Dai, Eric Pop. Thermally Limited Current Carrying Ability of Graphene Nanoribbons

  17. Guide to energy R and D programs for universities and other research groups

    International Nuclear Information System (INIS)

    1984-06-01

    The purpose of this guide to provide researchers in universities and other research institutions with summary-level information on the various research and development programs supported by the Department. Collectively, DOE programs support a wide range of research activities - from studies on the fundamental nature of matter and energy to exploratory and advanced research on the development of new technical approaches leading to new energy technologies. The guide summarizes, in one source, basic information on DOE's energy research and development and related programs, interests and needs. It supplies information on current Federal and DOE grant and contract policies and procedures and lists the names of DOE staff, by program area, from whom additional information may be obtained

  18. Technical Support Document: Development of the Advanced Energy Design Guide for K-12 Schools--30% Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Pless, S.; Torcellini, P.; Long, N.

    2007-09-01

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for K-12 School Buildings (K-12 AEDG), a design guidance document intended to provide recommendations for achieving 30% energy savings in K-12 Schools over levels contained in ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings. The 30% energy savings target is the first step toward achieving net-zero energy schools; schools that, on an annual basis, draw from outside sources less or equal energy than they generate on site from renewable energy sources.

  19. Guiding of low-energy electrons by highly ordered Al2 O3 nanocapillaries

    DEFF Research Database (Denmark)

    Milosavljević, A.R.; Víkor, G.; Pešić, Z.D.

    2007-01-01

    We report an experimental study of guided transmission of low-energy (200-350 eV) electrons through highly ordered Al2 O3 nanocapillaries with large aspect ratio (140 nm diameter and 15 μm length). The nanochannel array was prepared using self-ordering phenomena during a two-step anodization...... process of a high-purity aluminum foil. The experimental results clearly show the existence of the guiding effect, as found for highly charged ions. The guiding of the electron beam was observed for tilt angles up to 12°. As seen for highly charged ions, the guiding efficiency increases with decreasing...

  20. Energy Provisions of the ICC-700, LEED for Homes, and ENERGY STAR Mapped to the 2009 IECC

    Energy Technology Data Exchange (ETDEWEB)

    Britt, Michelle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Robin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kora, Angela R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Makela, Eric J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Makela, Erin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2011-05-01

    This document provides the results of a comparison of building energy efficient elements of the ICC-700 National Green Building Standard, LEED for Homes, and ENERGY STAR versions 2, 2.5, and 3.0 to the 2009 International Energy Conservation Code (2009 IECC). This comparison will provide a tool for states and local municipalities as they consider adoption of these programs. The comparison is presented in a series of appendices. The first appendix provides a summary chart that visually represents the comprehensive comparison of the programs to the 2009 IECC topic areas. Next there are a series of individual tables (one appendix for each program) that include the specific program mapping to the 2009 IECC elements with comments that briefly discuss how well the elements mapped. Finally, a comprehensive table is included that shows all five of the programs mapped to the 2009 IECC elements to allow a detailed comparison.

  1. Neutron stars: Observational diversity and evolution

    Science.gov (United States)

    Safi-Harb, S.

    2017-12-01

    Ever since the discovery of the Crab and Vela pulsars in their respective Supernova Remnants, our understanding of how neutron stars manifest themselves observationally has been dramatically shaped by the surge of discoveries and dedicated studies across the electromagnetic spectrum, particularly in the high-energy band. The growing diversity of neutron stars includes the highly magnetized neutron stars (magnetars) and the Central Compact Objects shining in X-rays and mostly lacking pulsar wind nebulae. These two subclasses of high-energy objects, however, seem to be characterized by anomalously high or anomalously low surface magnetic fields (thus dubbed as ‘magnetars’ and ‘anti-magnetars’, respectively), and have pulsar characteristic ages that are often much offset from their associated SNRs’ ages. In addition, some neutron stars act ‘schizophrenic’ in that they occasionally display properties that seem common to more than one of the defined subclasses. I review the growing diversity of neutron stars from an observational perspective, then highlight recent and on-going theoretical and observational work attempting to address this diversity, particularly in light of their magnetic field evolution, energy loss mechanisms, and supernova progenitors’ studies.

  2. Evolution of Neutron Stars and Observational Constraints

    Directory of Open Access Journals (Sweden)

    Lattimer J.

    2010-10-01

    Full Text Available The structure and evolution of neutron stars is discussed with a view towards constraining the properties of high density matter through observations. The structure of neutron stars is illuminated through the use of several analytical solutions of Einstein’s equations which, together with the maximally compact equation of state, establish extreme limits for neutron stars and approximations for binding energies, moments of inertia and crustal properties as a function of compactness. The role of the nuclear symmetry energy is highlighted and constraints from laboratory experiments such as nuclear masses and heavy ion collisions are presented. Observed neutron star masses and radius limits from several techniques, such as thermal emissions, X-ray bursts, gammaray flares, pulsar spins and glitches, spin-orbit coupling in binary pulsars, and neutron star cooling, are discussed. The lectures conclude with a discusson of proto-neutron stars and their neutrino signatures.

  3. AgSTAR

    Science.gov (United States)

    AgSTAR promotes biogas recovery projects, which generate renewable energy and other beneficial products from the anaerobic digestion of livestock manure and organic wastes while decreasing greenhouse gas emissions from the agriculture sector.

  4. Power performance measurements on Wave Star in Nissum Bredning. Final report; Wave energy converter; Effektmaalinger paa Wave Star i Nissum Bredning. Afsluttende rapport

    Energy Technology Data Exchange (ETDEWEB)

    Frigaard, P.; Lykke Andersen, T.

    2009-04-15

    The Wave Star test machine in Nissum Bredning was put in continuous operation on 24 July 2006. Over the past 2 1/2 years the produced power was measured continuously and with only minor interruptions. The measurements cover operation for all seasons in a very changeable climate. There is thus gaining operational experience under different wave conditions. In the period the machine has been running with a simple form of control and Power Take Off system (PTO), which form the background for effect measurements with the existing control strategy. Calculations have shown that the use of more advanced forms of control can increase the efficiency of Wave Star significantly. New control systems are therefore still under development with the primary objective to increase performance from the wave energy plant. To test and develop the methods, a new mini-hydraulic station with associated second generation PTO was developed and constructed for testing in Nissum Bredning. The mini-hydraulic station is coupled to a single float, while the other machine's 39 floats are still connected to the existing PTO system. As the existing PTO system can be applied to the 39 floats simultaneously with the new PTO used on 1 float, effect can be measured on the two systems simultaneously. The first tentative experiments with the new second generation PTO seem very promising. During the first measurements made in March 2009 the new system achieved an average yield of 3.1 times the average output from a float on the existing machine. In the coming period more experiments will be performed with the mini-hydraulic station to test the new PTO in various sea conditions. Since the mini-hydraulic station can simulate various forms of control, they also will be tested under real wave conditions in Nissum Bredning. The effect optimization should continue to be subject to a greater targeted effort, as improvements in this area can increase energy production and thus reduce the kWh cost of energy

  5. Systematic search for very-high-energy gamma-ray emission from bow shocks of runaway stars

    Science.gov (United States)

    H.E.S.S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Coffaro, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Richter, S.; Rieger, F.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.

    2018-04-01

    Context. Runaway stars form bow shocks by ploughing through the interstellar medium at supersonic speeds and are promising sources of non-thermal emission of photons. One of these objects has been found to emit non-thermal radiation in the radio band. This triggered the development of theoretical models predicting non-thermal photons from radio up to very-high-energy (VHE, E ≥ 0.1 TeV) gamma rays. Subsequently, one bow shock was also detected in X-ray observations. However, the data did not allow discrimination between a hot thermal and a non-thermal origin. Further observations of different candidates at X-ray energies showed no evidence for emission at the position of the bow shocks either. A systematic search in the Fermi-LAT energy regime resulted in flux upper limits for 27 candidates listed in the E-BOSS catalogue. Aim. Here we perform the first systematic search for VHE gamma-ray emission from bow shocks of runaway stars. Methods: Using all available archival H.E.S.S. data we search for very-high-energy gamma-ray emission at the positions of bow shock candidates listed in the second E-BOSS catalogue release. Out of the 73 bow shock candidates in this catalogue, 32 have been observed with H.E.S.S. Results: None of the observed 32 bow shock candidates in this population study show significant emission in the H.E.S.S. energy range. Therefore, flux upper limits are calculated in five energy bins and the fraction of the kinetic wind power that is converted into VHE gamma rays is constrained. Conclusions: Emission from stellar bow shocks is not detected in the energy range between 0.14 and 18 TeV.The resulting upper limits constrain the level of VHE gamma-ray emission from these objects down to 0.1-1% of the kinetic wind energy.

  6. Stars the size of planets

    International Nuclear Information System (INIS)

    Whitehouse, D.

    1984-01-01

    Red dwarf stars, the faintest and smallest stars that can be seen, sometimes host flares of immense violence. The article discusses the energy of these flares in terms of mass, x-rays, brightness, variation in light output, the sun and magnetic phenomena. (U.K.)

  7. The reHABITAT Guide: For Energy- and Resource-Efficient Retrofit Strategies

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-07-01

    This guide seeks to advance the goal of the U.S. Department of Energy’s Existing Residential Buildings Program (ERBP): to develop approaches that will enable the housing retrofit industry to deliver energy-efficient housing improvements.

  8. Observations of the star Cor Caroli at the Apple Valley Workshop 2016

    Science.gov (United States)

    Estrada, Reed; Boyd, Sidney; Estrada, Chris; Evans, Cody; Rhoades, Hannah; Rhoades, Mark; Rhoades, Trevor

    2017-06-01

    Using a 22-inch Newtonian Alt/Az telescope and Celestron Micro Guide eyepiece, students participating in a workshop observed the binary star Cor Caroli (STF 1692) and found a position angle of 231.0 degrees as well as an average separation of 18.7" This observation compared favorably with the 2015 Washington Double Star published position. This project was part of Mark Brewer's Apple Valley Double Star Workshop. The results were analyzed using bias and circle error probability calculations.

  9. Energy Management in Four and Five Star Hotels in Algarve (Portugal

    Directory of Open Access Journals (Sweden)

    Joana Mendes

    2014-07-01

    Full Text Available Tourism is the sector of the global economy that has grown faster, in such way that the United Nations World Tourism Organization (UNWTO predicts a global average annual growth between 1995 and 2020, around 4.1%. This growth should contribute to a sustainable development and, be accompanied by environmental awareness of all stakeholders, and strategies of change pointing towards the preservation of environment, so as not to endanger the natural resources of future generations. Energy Management in tourism is the central theme of this research. The setting was 4 and 5 star hotels in Algarve, the most important tourist destination of Portugal. The main objectives of the study were to assess the current state of energy management in those hotels, understand the policies and strategies followed to optimize energy management, and analyze best practices. Results show a higher level of implementation of practices directly related to the optimization of energy than those related to reducing environmental impacts. In general, respondents consider that energy management is part of the concerns of those responsible for the hotels, the level of implementation of good practices in this area is high (78% and that both employees and tourists attach great importance to this issue.

  10. Guided transmission of highly charged ions through nanocapillaries in PET. Study of the energy dependencies

    International Nuclear Information System (INIS)

    Helhammer, R.; Pesic, Z.D.; Sobocinski, P.; Bundesmann, J.; Fink, D.; Stolterfoht, N.; Sulik, B.

    2004-01-01

    Full text: Recently we reported experiments in which slow highly charged ions are transmitted through nanocapillaries of 100nm diameter in an insulating PET foil of 10μm thickness [1]. The results of this work differ significantly from previous studies, which have been focused on capillaries in metals [2]. We measured the transmission of 3 keV Ne 7+ ions through the capillaries and focused the attention on ions whose charge has not changed during the passage through the capillary. The observation that the angular distribution for PET has a peak maximum whose position is equal to the tilt angle indicates a guiding of the Ne 7+ ion within the capillary. This guiding shows that the inner walls of the capillaries are charged up in a self-organizing process and collisions with the surface are finally prevented. We studied the time evolution of the capillary guiding as well as dependencies on the tilt angle [3]. Our most recent measurements were focussed on the investigation of the energy dependency for the guiding of Ne 7+ through capillaries. The measurements were done in an energy range from 2 keV up to 10 keV.We measured higher guiding efficiency for lower energies consistent with a previously developed model, which predicted an increase of the guiding efficiency with decreasing projectile energy [3]. In addition we found the effect of a narrower width of the angular distribution of transmitted ions. This effect is also well described by the model. However, further work is needed to explain the amount of charges to build up the deflection field at the end of the capillaries

  11. The reHABITAT Guide: For Energy- and Resource-Efficient Retrofit Strategies; February 2003--February 2004

    Energy Technology Data Exchange (ETDEWEB)

    2004-07-01

    The reHABITAT Guide for Energy- and Resource-Efficient Retrofit Strategies seeks to advance the goal of the U.S. Department of Energy's Existing Residential Buildings Program (ERBP): to develop approaches that will enable the housing retrofit industry to deliver energy-efficient housing improvements and to ensure that energy-efficient retrofit technologies incorporated into projects are viable over conventional approaches. This guide was developed for Habitat for Humanity International and is the result of lessons learned from demonstration retrofit projects undertaken by Habitat for Humanity affiliates in Newburgh, New York; Baltimore, Maryland; and Philadelphia, Pennsylvania; with building systems consulting and technical assistance provided by Steven Winter Associates, Inc. (SWA).

  12. Contracting for Efficiency. A Best Practices Guide for Energy-Efficient Product Procurement

    Energy Technology Data Exchange (ETDEWEB)

    Bunch, Saralyn [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Payne, Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-01

    The requirement to buy energy- and water-efficient products applies to federal purchases made through any procurement pathway (e.g., purchase cards, e-retailers, and solicitations) and to a wide variety of federal projects. The Federal Energy Management Program’s (FEMP's) Buy Energy-Efficient Products buyer overview fact sheet and Contracting for Efficiency best practices guide for product procurement are designed to support federal buyers in the purchase of energy- and water-efficient products.

  13. Contracting for Efficiency: A Best Practices Guide for Energy Efficient Product Procurement

    Energy Technology Data Exchange (ETDEWEB)

    Bunch, Saralyn [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Payne, Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-11-01

    The requirement to buy energy- and water-efficient products applies to federal purchases made through any procurement pathway (e.g., purchase cards, e-retailers, and solicitations) and to a wide variety of federal projects. The Federal Energy Management Program’s (FEMP's) Buy Energy-Efficient Products buyer overview fact sheet and Contracting for Efficiency best practices guide for product procurement are designed to support federal buyers in the purchase of energy- and water-efficient products.

  14. Nuclear physics of stars

    CERN Document Server

    Iliadis, Christian

    2007-01-01

    Thermonuclear reactions in stars is a major topic in the field of nuclear astrophysics, and deals with the topics of how precisely stars generate their energy through nuclear reactions, and how these nuclear reactions create the elements the stars, planets and - ultimately - we humans consist of. The present book treats these topics in detail. It also presents the nuclear reaction and structure theory, thermonuclear reaction rate formalism and stellar nucleosynthesis. The topics are discussed in a coherent way, enabling the reader to grasp their interconnections intuitively. The book serves bo

  15. Mass-Radius diagram for compact stars

    International Nuclear Information System (INIS)

    Carvalho, G A; Jr, R M Marinho; Malheiro, M

    2015-01-01

    The compact stars represent the final stage in the evolution of ordinary stars, they are formed when a star ceases its nuclear fuel, in this point the process that sustain its stability will stop. After this, the internal pressure can no longer stand the gravitational force and the star colapses [2]. In this work we investigate the structure of these stars which are described by the equations of Tolman-Openheimer-Volkof (TOV) [1]. These equations show us how the pressure varies with the mass and radius of the star. We consider the TOV equations for both relativistic and non-relativistic cases. In the case of compact stars (white dwarfs and neutron stars) the internal pressure that balances the gravitational pressure is essentialy the pressure coming from the degeneracy of fermions. To have solved the TOV equations we need a equation of state that shows how this internal pressure is related to the energy density or mass density. Instead of using politropic equations of state we have solved the equations numericaly using the exact relativistic energy equation for the model of fermion gas at zero temperature. We obtain results for the mass-radius relation for white dwarfs and we compared with the results obtained using the politropic equations of state. In addition we discussed a good fit for the mass-radius relation. (paper)

  16. The origin of Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Doom, C.

    1987-01-01

    The paper reviews the origin of Wolf-Rayet (WR) stars, with emphasis on the so-called Population I WR stars which are associated with the young and luminous stellar population. A description is given of the observational characteristics i.e. classification, luminosities composition, etc. of WR stars. The origin and evolution of WR stars is described, including the single, binary, subtypes and ratio WR/O. The interaction of the WR stars with their environment is discussed with respect to the energy deposition and composition anomalies. A brief account of the discovery of WR stars in other galaxies is given. Finally, some of the main issues in the research into the structure and evolution of WR stars are outlined. (U.K.)

  17. The embedded young stars in the Taurus-Auriga molecular cloud. I - Models for spectral energy distributions

    Science.gov (United States)

    Kenyon, Scott J.; Calvet, Nuria; Hartmann, Lee

    1993-01-01

    We describe radiative transfer calculations of infalling, dusty envelopes surrounding pre-main-sequence stars and use these models to derive physical properties for a sample of 21 heavily reddened young stars in the Taurus-Auriga molecular cloud. The density distributions needed to match the FIR peaks in the spectral energy distributions of these embedded sources suggest mass infall rates similar to those predicted for simple thermally supported clouds with temperatures about 10 K. Unless the dust opacities are badly in error, our models require substantial departures from spherical symmetry in the envelopes of all sources. These flattened envelopes may be produced by a combination of rotation and cavities excavated by bipolar flows. The rotating infall models of Terebey et al. (1984) models indicate a centrifugal radius of about 70 AU for many objects if rotation is the only important physical effect, and this radius is reasonably consistent with typical estimates for the sizes of circumstellar disks around T Tauri stars.

  18. Energy efficiency improvement and cost saving opportunities for the Corn Wet Milling Industry: An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Worrell, Ernst; Ruth, Michael

    2003-07-01

    Corn wet milling is the most energy intensive industry within the food and kindred products group (SIC 20), using 15 percent of the energy in the entire food industry. After corn, energy is the second largest operating cost for corn wet millers in the United States. A typical corn wet milling plant in the United States spends approximately $20 to $30 million per year on energy, making energy efficiency improvement an important way to reduce costs and increase predictable earnings, especially in times of high energy-price volatility. This report shows energy efficiency opportunities available for wet corn millers. It begins with descriptions of the trends, structure and production of the corn wet milling industry and the energy used in the milling and refining process. Specific primary energy savings for each energy efficiency measure based on case studies of plants and references to technical literature are provided. If available, typical payback periods are also listed. The report draws upon the experiences of corn, wheat and other starch processing plants worldwide for energy efficiency measures. The findings suggest that given available resources and technology, there are opportunities to reduce energy consumption cost-effectively in the corn wet milling industry while maintaining the quality of the products manufactured. Further research on the economics of the measures, as well as the applicability of these to different wet milling practices, is needed to assess the feasibility of implementation of selected technologies at individual plants.

  19. Guide to funding sources for renewable energy in schools and colleges

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This guide has been designed specifically to identify sources of funding for renewable energy projects in schools, such as a wind generator or a solar water heating system. It is intended for teachers or Friends of associations. (author)

  20. Possibilities of saving energy by using intelligent star-delta switches; Energiesparmoeglichkeiten mit intelligenten Stern-Dreieckschaltern

    Energy Technology Data Exchange (ETDEWEB)

    Gloor, R.

    2006-07-01

    This final report published by the Swiss Federal Office of Energy (SFOE) presents the results of a study made on so-called intelligent switches that switch an induction motor automatically into star configuration when at low load and, when higher loading returns, back again into the delta configuration. The results of theoretical calculations and measurements made in practice are discussed. The results are presented for various application areas including hydraulics, dynamic converters and standard applications. Also, the use of switches in applications such as wood-cutters, transport systems and stone-crushers are looked at. The results are discussed and the possible risks involved in the use of star-delta switches are looked at. Conclusions are drawn on their use from the economical point of view.

  1. CG-DAR-1: Guide to the declassified areas of nuclear energy research

    International Nuclear Information System (INIS)

    Lytle, J.E.

    1984-08-01

    This guide, which is based on classification of information by the Atomic Energy Act of 1954, as amended, and on subsequent declassification actions by the Department of Energy (DOE) and its predecessors, is intended to identify those areas of nuclear research and development that have been removed from the Restricted Data (RD) category and declassified

  2. Guide for biogas energy utilization in Hokkaido; Hokkaido bio gas energy riyo guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of smoothly introducing biogas plants to Hokkaido in the future, the following were conducted: collection of the data on samples of development/introduction of biogas plants, survey of the organizations concerned, etc., study of economical efficiency, etc. Those were arranged as a guide for biogas energy utilization in Hokkaido. In the biogas plant, organic matters such as animal faces, garbage, etc. are anaerobicly fermented at medium temperatures between 35 and 38 degrees C or at about 55 degrees C to obtain biogas including methane gas of approximately 60%. From this gas, heat is obtained by gas boiler, and also electricity and heat are obtained by gas cogeneration or fuel cells. In the case of introducing the biogas plant using animal faces as raw material in Hokkaido, it is important to cover all the electricity and heat used to maintain the plant with the biogas obtained, from a viewpoint of economical efficiency. In the present situation, it is the most economical for each farmer to introduce an individual plant to be installed and to obtain the power generated and heat. (NEDO)

  3. Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Regnier, Cindy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

  4. B- AND A-TYPE STARS IN THE TAURUS-AURIGA STAR-FORMING REGION

    International Nuclear Information System (INIS)

    Mooley, Kunal; Hillenbrand, Lynne; Rebull, Luisa; Padgett, Deborah; Knapp, Gillian

    2013-01-01

    We describe the results of a search for early-type stars associated with the Taurus-Auriga molecular cloud complex, a diffuse nearby star-forming region noted as lacking young stars of intermediate and high mass. We investigate several sets of possible O, B, and early A spectral class members. The first is a group of stars for which mid-infrared images show bright nebulae, all of which can be associated with stars of spectral-type B. The second group consists of early-type stars compiled from (1) literature listings in SIMBAD, (2) B stars with infrared excesses selected from the Spitzer Space Telescope survey of the Taurus cloud, (3) magnitude- and color-selected point sources from the Two Micron All Sky Survey, and (4) spectroscopically identified early-type stars from the Sloan Digital Sky Survey coverage of the Taurus region. We evaluated stars for membership in the Taurus-Auriga star formation region based on criteria involving: spectroscopic and parallactic distances, proper motions and radial velocities, and infrared excesses or line emission indicative of stellar youth. For selected objects, we also model the scattered and emitted radiation from reflection nebulosity and compare the results with the observed spectral energy distributions to further test the plausibility of physical association of the B stars with the Taurus cloud. This investigation newly identifies as probable Taurus members three B-type stars: HR 1445 (HD 28929), τ Tau (HD 29763), 72 Tau (HD 28149), and two A-type stars: HD 31305 and HD 26212, thus doubling the number of stars A5 or earlier associated with the Taurus clouds. Several additional early-type sources including HD 29659 and HD 283815 meet some, but not all, of the membership criteria and therefore are plausible, though not secure, members.

  5. Spectroscopic survey of Kepler stars - II. FIES/NOT observations of A- and F-type stars

    Science.gov (United States)

    Niemczura, E.; Polińska, M.; Murphy, S. J.; Smalley, B.; Kołaczkowski, Z.; Jessen-Hansen, J.; Uytterhoeven, K.; Lykke, J. M.; Triviño Hage, A.; Michalska, G.

    2017-09-01

    We have analysed high-resolution spectra of 28 A and 22 F stars in the Kepler field, observed using the Fibre-Fed Échelle Spectrograph at the Nordic Optical Telescope. We provide spectral types, atmospheric parameters and chemical abundances for 50 stars. Balmer, Fe I and Fe II lines were used to derive effective temperatures, surface gravities and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined from the spectral line analysis. The stars analysed include chemically peculiar stars of the Am and λ Boo types, as well as stars with approximately solar chemical abundances. The wide distribution of projected rotational velocity, vsin I, is typical for A and F stars. The microturbulence velocities obtained are typical for stars in the observed temperature and surface gravity ranges. Moreover, we affirm the results of Niemczura et al. that Am stars do not have systematically higher microturbulent velocities than normal stars of the same temperature.

  6. Röntgen spheres around active stars

    Science.gov (United States)

    Locci, Daniele; Cecchi-Pestellini, Cesare; Micela, Giuseppina; Ciaravella, Angela; Aresu, Giambattista

    2018-01-01

    X-rays are an important ingredient of the radiation environment of a variety of stars of different spectral types and age. We have modelled the X-ray transfer and energy deposition into a gas with solar composition, through an accurate description of the electron cascade following the history of the primary photoelectron energy deposition. We test and validate this description studying the possible formation of regions in which X-rays are the major ionization channel. Such regions, called Röntgen spheres may have considerable importance in the chemical and physical evolution of the gas embedding the emitting star. Around massive stars the concept of Röntgen sphere appears to be of limited use, as the formation of extended volumes with relevant levels of ionization is efficient just in a narrow range of gas volume densities. In clouds embedding low-mass pre-main-sequence stars significant volumes of gas are affected by ionization levels exceeding largely the cosmic-ray background ionization. In clusters arising in regions of vigorous star formation X-rays create an ionization network pervading densely the interstellar medium, and providing a natural feedback mechanism, which may affect planet and star formation processes.

  7. Thin accretion disks around cold Bose-Einstein condensate stars

    Energy Technology Data Exchange (ETDEWEB)

    Danila, Bogdan [Babes-Bolyai University, Department of Physics, Cluj-Napoca (Romania); Harko, Tiberiu [University College London, Department of Mathematics, London (United Kingdom); Kovacs, Zoltan

    2015-05-15

    Due to their superfluid properties some compact astrophysical objects, like neutron or quark stars, may contain a significant part of their matter in the form of a Bose-Einstein condensate (BEC). Observationally distinguishing between neutron/quark stars and BEC stars is a major challenge for this latter theoretical model. An observational possibility of indirectly distinguishing BEC stars from neutron/quark stars is through the study of the thin accretion disks around compact general relativistic objects. In the present paper, we perform a detailed comparative study of the electromagnetic and thermodynamic properties of the thin accretion disks around rapidly rotating BEC stars, neutron stars and quark stars, respectively. Due to the differences in the exterior geometry, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution, equilibrium radiation spectrum, and efficiency of energy conversion) are different for these classes of compact objects. Hence in this preliminary study we have pointed out some astrophysical signatures that may allow one to observationally discriminate between BEC stars and neutron/quark stars. (orig.)

  8. The Destructive Birth of Massive Stars and Massive Star Clusters

    Science.gov (United States)

    Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

    2017-01-01

    Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

  9. The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets.

    Science.gov (United States)

    Shields, Aomawa L; Meadows, Victoria S; Bitz, Cecilia M; Pierrehumbert, Raymond T; Joshi, Manoj M; Robinson, Tyler D

    2013-08-01

    Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. In this study, we explored this effect with a one-dimensional (1-D), line-by-line, radiative transfer model to calculate broadband planetary albedos as input to a seasonally varying, 1-D energy balance climate model. A three-dimensional (3-D) general circulation model was also used to explore the atmosphere's response to changes in incoming stellar radiation, or instellation, and surface albedo. Using this hierarchy of models, we simulated planets covered by ocean, land, and water-ice of varying grain size, with incident radiation from stars of different spectral types. Terrestrial planets orbiting stars with higher near-UV radiation exhibited a stronger ice-albedo feedback. We found that ice extent was much greater on a planet orbiting an F-dwarf star than on a planet orbiting a G-dwarf star at an equivalent flux distance, and that ice-covered conditions occurred on an F-dwarf planet with only a 2% reduction in instellation relative to the present instellation on Earth, assuming fixed CO(2) (present atmospheric level on Earth). A similar planet orbiting the Sun at an equivalent flux distance required an 8% reduction in instellation, while a planet orbiting an M-dwarf star required an additional 19% reduction in instellation to become ice-covered, equivalent to 73% of the modern solar constant. The reduction in instellation must be larger for planets orbiting cooler stars due in large part to the stronger absorption of longer-wavelength radiation by icy surfaces on these planets in addition to stronger absorption by water vapor and CO(2) in their atmospheres, which provides increased downwelling longwave radiation. Lowering the IR and visible-band surface ice and snow albedos for an M-dwarf planet increased the planet's climate stability against changes in instellation and slowed the descent into global ice

  10. Alaska: a guide to geothermal energy development

    Energy Technology Data Exchange (ETDEWEB)

    Basescu, N.; Bloomquist, R.G.; Higbee, C.; Justus, D.; Simpson, S.

    1980-06-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  11. Washington: a guide to geothermal energy development

    Energy Technology Data Exchange (ETDEWEB)

    Bloomquist, R.G.; Basescu, N.; Higbee, C.; Justus, D.; Simpson, S.

    1980-01-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  12. The energy-momentum tensor for the linearized Maxwell-Vlasov and kinetic guiding center theories

    International Nuclear Information System (INIS)

    Pfirsch, D.; Morrison, P.J.; Texas Univ., Austin

    1990-02-01

    A modified Hamilton-Jacobi formalism is introduced as a tool to obtain the energy-momentum and angular-momentum tensors for any kind of nonlinear or linearized Maxwell-collisionless kinetic theories. The emphasis is on linearized theories, for which these tensors are derived for the first time. The kinetic theories treated - which need not be the same for all particle species in a plasma - are the Vlasov and kinetic guiding center theories. The Hamiltonian for the guiding center motion is taken in the form resulting from Dirac's constraint theory for non-standard Lagrangian systems. As an example of the Maxwell-kinetic guiding center theory, the second-order energy for a perturbed homogeneous magnetized plasma is calculated with initially vanishing field perturbations. The expression obtained is compared with the corresponding one of Maxwell-Vlasov theory. (orig.)

  13. The energy-momentum tensor for the linearized Maxwell-Vlasov and kinetic guiding center theories

    International Nuclear Information System (INIS)

    Pfirsch, D.; Morrison, P.J.

    1990-02-01

    A modified Hamilton-Jacobi formalism is introduced as a tool to obtain the energy-momentum and angular-momentum tensors for any king of nonlinear or linearized Maxwell-collisionless kinetic theories. The emphasis is on linearized theories, for which these tensors are derived for the first time. The kinetic theories treated --- which need not be the same for all particle species in a plasma --- are the Vlasov and kinetic guiding center theories. The Hamiltonian for the guiding center motion is taken in the form resulting from Dirac's constraint theory for non-standard Lagrangian systems. As an example of the Maxwell-kinetic guiding center theory, the second-order energy for a perturbed homogeneous magnetized plasma is calculated with initially vanishing field perturbations. The expression obtained is compared with the corresponding one of Maxwell-Vlasov theory. 11 refs

  14. SEE Action Guide for States: Energy Efficiency as a Least-Cost Strategy to Reduce Greenhouse Gases and Air Pollution and Meet Energy Needs in the Power Sector

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leventis, Greg [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steven R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fadrhonc, Emily Martin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); shenot, John [US Department of Energy, Washington, DC (United States); Colburn, Ken [US Department of Energy, Washington, DC (United States); James, Chris [US Department of Energy, Washington, DC (United States); Zetterberg, Johanna [US Department of Energy, Washington, DC (United States); Roy, Molly [US Department of Energy, Washington, DC (United States)

    2016-02-01

    This guide is designed to provide information to state decision makers and staff on options to advance energy efficiency through strategies designed or implemented at the state and local levels of government and in the private sector.1 The information in this guide is intended to be useful to a wide variety of partners and stakeholders involved in energy-related discussions and decision-making at state and local levels. These energy efficiency options, or “pathways” as they are identified in this guide, can assist states in using energy efficiency to meet air pollution reduction and other policy objectives such as energy affordability and reliability. A pathway is a set of interdependent actions that results in measurable energy savings streams and associated avoided air emissions and other benefits over a period of time. These activities can include state, local, or private sector regulations, policies, programs and other activities. For each of five broad pathways that offer sizable cost-effective energy savings, the guide addresses likely questions policy makers and regulators face when screening for the best opportunities to advance energy efficiency in their state.

  15. Cooling of Accretion-Heated Neutron Stars

    Indian Academy of Sciences (India)

    Rudy Wijnands

    2017-09-12

    Sep 12, 2017 ... the magnetic field might play an important role in the heating and cooling of the neutron stars. .... Source near Sgr A ..... marked the start of the research field that uses the cool- ... This curve is just to guide the eye for the individual sources and it is clear ..... Not all accretion-induced nuclear reactions might.

  16. Spectroscopic survey of Kepler stars - II. FIES/NOT observations of A- and F-type stars

    DEFF Research Database (Denmark)

    Niemczura, E.; Polinska, M.; Murphy, S. J.

    2017-01-01

    to derive effective temperatures, surface gravities and microturbulent velocities. We determined chemical abundances and projected rotational velocities using a spectrum synthesis technique. Effective temperatures calculated by spectral energy distribution fitting are in good agreement with those determined...... obtained are typical for stars in the observed temperature and surface gravity ranges. Moreover, we affirm the results of Niemczura et al. that Am stars do not have systematically higher microturbulent velocities than normal stars of the same temperature....

  17. Energy efficiency survey in Nigeria. A guide to developing policy and legislation

    Energy Technology Data Exchange (ETDEWEB)

    Uyigue, Etiosa; Agho, Matthew; Edevbaro, Agharese; Godfrey, Ogbemudia Osamuyi; Uyigue, Osazee Paul; Okungbowa, Ose Golden

    2009-09-15

    In Nigeria, experts have asserted that Nigeria can save up to half of the energy currently consumed in the country if energy is efficiently utilized. The major challenge has been that energy policy in Nigeria has undermined the importance and gains of energy efficiency to the environment and economic growth. In the midst of the prevailing energy crisis in Nigeria, energy efficiency will play a pivotal role in ensuring access to energy. Efficiency is not only cheaper than all other options; it also leads to growth in jobs and personal income. By reducing energy bills, it frees up money that can be spent elsewhere in the economy. It appears that the concept of energy efficiency seems to be poorly developed in Nigeria. Having discovered the policy gaps in the Nigerian system on energy efficiency, the Community Research and Development Centre designed and embarked on a research that will help to provide guideline for developing policy and legislation in the energy sector. We discovered that there is absence of research materials and data that will guide and strengthen regulatory measures to use energy efficiently in Nigeria. Hence the research was embarked upon to elicit information that will guide the development of energy efficiency policy which will in turn strengthen regulatory measures to use energy efficiently in Nigeria. In this study, we are focusing on the management of electricity; though energy efficiency is applicable to other forms of energy. Another objective of the study is to identify commercially and behaviorally low-cost ways of reducing energy consumption in the residential, public and private sectors in Nigeria. The information from this study, we believe will help to develop energy efficiency policy document applicable in Nigeria. The research will also help to identify renewable energy potential in the different regions of Nigeria. This document will also serve as a training manual for conferences and workshops.

  18. Procuring Solar Energy: A Guide for Federal Facility Decision Makers, September 2010

    Energy Technology Data Exchange (ETDEWEB)

    Stoltenberg, B.; Partyka, E.

    2010-09-01

    This guide presents an overview of the process for successfully planning for and installing solar technology on a federal site. It is specifically targeted to managers of federal buildings and sites, contracting officers, energy and sustainability officers, and regional procurement managers. The solar project process is outlined in a concise, easy-to-understand, step-by-step format. Information includes a brief overview of legislation and executive orders related to renewable energy and the compelling reasons for implementing a solar project on a federal site. It also includes how to assess a facility to identify the best solar installation site, project recommendations and considerations to help avoid unforeseen issues, and guidance on financing and contracting options. Case studies with descriptions of successful solar deployments across multiple agencies are presented. In addition, detailed information and sample documents for specific tasks are referenced with Web links or included in the appendixes. The guide concentrates on distributed solar generation and not large, centralized solar energy generation.

  19. Procuring Solar Energy: A Guide for Federal Facility Decision Makers, September 2010

    International Nuclear Information System (INIS)

    Stoltenberg, B.; Partyka, E.

    2010-01-01

    This guide presents an overview of the process for successfully planning for and installing solar technology on a federal site. It is specifically targeted to managers of federal buildings and sites, contracting officers, energy and sustainability officers, and regional procurement managers. The solar project process is outlined in a concise, easy-to-understand, step-by-step format. Information includes a brief overview of legislation and executive orders related to renewable energy and the compelling reasons for implementing a solar project on a federal site. It also includes how to assess a facility to identify the best solar installation site, project recommendations and considerations to help avoid unforeseen issues, and guidance on financing and contracting options. Case studies with descriptions of successful solar deployments across multiple agencies are presented. In addition, detailed information and sample documents for specific tasks are referenced with Web links or included in the appendixes. The guide concentrates on distributed solar generation and not large, centralized solar energy generation.

  20. NWTC Helps Guide U.S. Offshore R&D; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-07-01

    The National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) is helping guide our nation's research-and-development effort in offshore renewable energy, which includes: Design, modeling, and analysis tools; Device and component testing; Resource characterization; Economic modeling and analysis; Grid integration.

  1. Solar Energy Education. Home economics: teacher's guide. Field test edition. [Includes glossary

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    An instructional aid is provided for home economics teachers who wish to integrate the subject of solar energy into their classroom activities. This teacher's guide was produced along with the student activities book for home economics by the US Department of Energy Solar Energy Education. A glossary of solar energy terms is included. (BCS)

  2. UV-luminous, star-forming hosts of z ˜ 2 reddened quasars in the Dark Energy Survey

    Science.gov (United States)

    Wethers, C. F.; Banerji, M.; Hewett, P. C.; Lemon, C. A.; McMahon, R. G.; Reed, S. L.; Shen, Y.; Abdalla, F. B.; Benoit-Lévy, A.; Brooks, D.; Buckley-Geer, E.; Capozzi, D.; Carnero Rosell, A.; CarrascoKind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Doel, P.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jeltema, T.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Martini, P.; Menanteau, F.; Miquel, R.; Nichol, R. C.; Nord, B.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Walker, A. R.

    2018-04-01

    We present the first rest-frame UV population study of 17 heavily reddened, high-luminosity [E(B - V)QSO ≳ 0.5; Lbol > 1046 erg s-1] broad-line quasars at 1.5 VISTA Hemisphere Survey and UKIDSS Large Area Survey data, from which the reddened quasars were initially identified. We demonstrate that the significant dust reddening towards the quasar in our sample allows host galaxy emission to be detected at the rest-frame UV wavelengths probed by the DES photometry. By exploiting this reddening effect, we disentangle the quasar emission from that of the host galaxy via spectral energy distribution fitting. We find evidence for a relatively unobscured, star-forming host galaxy in at least 10 quasars, with a further three quasars exhibiting emission consistent with either star formation or scattered light. From the rest-frame UV emission, we derive instantaneous, dust-corrected star formation rates (SFRs) in the range 25 < SFRUV < 365 M⊙ yr-1, with an average SFRUV = 130 ± 95 M⊙ yr-1. We find a broad correlation between SFRUV and the bolometric quasar luminosity. Overall, our results show evidence for coeval star formation and black hole accretion occurring in luminous, reddened quasars at the peak epoch of galaxy formation.

  3. Municipal energy audit: a practical guide to the identification of energy expenditures

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This publication was designed to provide small- to medium-sized Canadian municipalities with a ready-to-use, practical guide to indentify energy consumption and costs in all those operations that normally fall under the control of municipal governments. The manual was based on 7 pilot audits conducted in Ottawa, Ontario, Montague and Summerside, Prince Edward Island, Granby, Quebec, Victoria, British Columbia, St. John, New Brunswick, and Winnipeg, Manitoba, from which summaries of energy consumption patterns were drawn. Audit analysis is explained for such municipal responsibilities as street lighting, water supply, sewage disposal, public transit, police and fire protection services, garbage collection and disposal, snow and ice control and road maintenance in general, with figures presented from the survey results. A description of the audit method and worksheet forms are also included. 3 figs., 33 tabs.

  4. The STAR experiment at RHIC

    International Nuclear Information System (INIS)

    Marx, J.N.

    1994-01-01

    STAR (Solenoidal Tracker at RHIC) will be one of two large, sophisticated experiments ready to take data when the Relativistic Heavy Ion Collider (RHIC) comes on-line in 1999. The design of STAR, its construction and commissioning and the physics program using the detector are the responsibility of a collaboration of over 250 members from 30 institutions, world-wide. The overall approach of the STAR Collaboration to the physics challenge of studying collisions of highly relativistic nuclei is to focus on measurements of the properties of the many hadrons produced in the collisions. The STAR detector is optimized to detect and identify hadrons over a large solid angle so that individual events can be characterized, in detail, based on their hadronic content. The broad capabilities of the STAR detector will permit an examination of a wide variety of proposed signatures for the Quark Gluon Plasma (QGP), using the sample of events which, on an event-by-event basis, appear to come from collisions resulting in a large energy density over a nuclear volume. In order to achieve this goal, the STAR experiment is based on a solenoid geometry with tracking detectors using the time projection chamber approach and covering a large range of pseudo-rapidity so that individual tracks can be seen within the very high track density expected in central collisions at RHIC. STAR also uses particle identification by the dE/dx technique and by time-of-flight. Electromagnetic energy is detected in a large, solid-angle calorimeter. The construction of STAR, which will be located in the Wide Angle Hall at the 6 o'clock position at RHIC, formally began in early 1993

  5. YOUNG, ULTRAVIOLET-BRIGHT STARS DOMINATE DUST HEATING IN STAR-FORMING GALAXIES

    International Nuclear Information System (INIS)

    Law, Ka-Hei; Gordon, Karl D.; Misselt, K. A.

    2011-01-01

    In star-forming galaxies, dust plays a significant role in shaping the ultraviolet (UV) through infrared (IR) spectrum. Dust attenuates the radiation from stars, and re-radiates the energy through equilibrium and non-equilibrium emission. Polycyclic aromatic hydrocarbons (PAHs), graphite, and silicates contribute to different features in the spectral energy distribution; however, they are all highly opaque in the same spectral region-the UV. Compared to old stellar populations, young populations release a higher fraction of their total luminosity in the UV, making them a good source of the energetic UV photons that can power dust emission. However, given their relative abundance, the question of whether young or old stellar populations provide most of these photons that power the IR emission is an interesting question. Using three samples of galaxies observed with the Spitzer Space Telescope and our dusty radiative transfer model, we find that young stellar populations (on the order of 100 million years old) dominate the dust heating in star-forming galaxies, and old stellar populations (13 billion years old) generally contribute less than 20% of the far-IR luminosity.

  6. Illustrated Guide to Astronomical Wonders From Novice to Master Observer

    CERN Document Server

    Thompson, Robert

    2011-01-01

    With the advent of inexpensive, high-power telescopes priced at under 250, amateur astronomy is now within the reach of anyone, and this is the ideal book to get you started. The Illustrated Guide to Astronomical Wonders offers you a guide to the equipment you need, and shows you how and where to find hundreds of spectacular objects in the deep sky -- double and multiple stars as well as spectacular star clusters, nebulae, and galaxies. You get a solid grounding in the fundamental concepts and terminology of astronomy, and specific advice about choosing, buying, using, and maintaining the eq

  7. CALIBRATION OF THE NuSTAR HIGH-ENERGY FOCUSING X-RAY TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, Kristin K.; Harrison, Fiona A.; Grefenstette, Brian W.; Miyasaka, Hiromasa; Forster, Karl; Fuerst, Felix; Rana, Vikram; Walton, Dominic J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Markwardt, Craig B. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); An, Hongjun [Department of Physics, McGill University, Montreal, Quebec, H3A 2T8 (Canada); Bachetti, Matteo [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Kitaguchi, Takao [RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Bhalerao, Varun [Inter-University Center for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India); Boggs, Steve; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektronvej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, NY 10027 (United States); Perri, Matteo; Puccetti, Simonetta [ASI Science Data Center, via Galileo Galilei, I-00044, Frascati (Italy); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); and others

    2015-09-15

    We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles and energies, compared to the assumed spectrum, are typically better than ±2% up to 40 keV and 5%–10% above due to limited counting statistics. An empirical adjustment to the theoretical two-dimensional point-spread function (PSF) was found using several strong point sources, and no increase of the PSF half-power diameter has been observed since the beginning of the mission. We report on the detector gain calibration, good to 60 eV for all grades, and discuss the timing capabilities of the observatory, which has an absolute timing of ±3 ms. Finally, we present cross-calibration results from two campaigns between all the major concurrent X-ray observatories (Chandra, Swift, Suzaku, and XMM-Newton), conducted in 2012 and 2013 on the sources 3C 273 and PKS 2155-304, and show that the differences in measured flux is within ∼10% for all instruments with respect to NuSTAR.

  8. The star book stargazing throughout the seasons in the Northern hemisphere

    CERN Document Server

    Grego, Peter

    2012-01-01

    Stargazing Throughout the Seasons in the Northern Hemisphere is an excerpt from The Star Book that guides you through the night skies in the Northern Hemisphere, through wide-angle star charts. Looking at the main constellations, stars and celestial showpieces of the northern celestial sphere, beginning with constellations around the north pole and then taking a season by season view. Most northern constellations are as familiar to today's stargazers as they were to the ancient Greeks. Everyone is interested in the stars and on a clear night astonished by them. Stargazing Throughout the Seasons in the Northern Hemisphere will answer any questions you may have when you look up into the night sky.

  9. Demonstrating the likely neutron star nature of five M31 globular cluster sources with Swift-NuSTAR spectroscopy

    DEFF Research Database (Denmark)

    Maccarone, Thomas J.; Yukita, Mihoko; Hornschemeier, Ann

    2016-01-01

    of simultaneous Swift and NuSTAR spectra which cover a broader range of energies. These new observations reveal spectral curvature above 6-8 keV that would be hard to detect without the broader energy coverage the NuSTAR data provide relative to Chandra and XMM-Newton. We show that the other three sources...

  10. Dynamic energy conservation model REDUCE. Extension with experience curves, energy efficiency indicators and user's guide

    International Nuclear Information System (INIS)

    Uyterlinde, M.A.; Rijkers, F.A.M.

    1999-12-01

    The main objective of the energy conservation model REDUCE (Reduction of Energy Demand by Utilization of Conservation of Energy) is the evaluation of the effectiveness of economical, financial, institutional, and regulatory measures for improving the rational use of energy in end-use sectors. This report presents the results of additional model development activities, partly based on the first experiences in a previous project. Energy efficiency indicators have been added as an extra tool for output analysis in REDUCE. The methodology is described and some examples are given. The model has been extended with a method for modelling the effects of technical development on production costs, by means of an experience curve. Finally, the report provides a 'users guide', by describing in more detail the input data specification as well as all menus and buttons. 19 refs

  11. The energy-efficient Frankfurt. Travel-guide; Das energieeffiziente Frankfurt. Reisefuehrer

    Energy Technology Data Exchange (ETDEWEB)

    Gehbauer-Schumacher, Bettina

    2013-06-01

    Frankfurt is well along the way to being a 'Green City'. Its CO{sub 2} emissions have been reduced by more than 10% in the last 20 years. The energy-efficient office buildings, the Passive Houses, the combined heat and power production, the solar installations and the biomass power stations all contribute to climate protection in Frankfurt. This book leads you with guided tours through suburbs, past office buildings, estates and cultural establishments, all having remarkable energy saving measures and splendid architectural features, whilst at the same time pointing out significant sights. (orig.)

  12. Dinosaurs and Power Plants. Energy from the Past for the Future. Teacher's Lesson Plan and Activity Guide; Teacher's Guide Supplement of Reproducible Graphics.

    Science.gov (United States)

    Department of Energy, Washington, DC. Office of Fossil Energy.

    This teacher's guide and its accompanying supplement were prepared for use with the U.S. Department of Energy's Dinosaurs and Power Plants, a publication designed for students in grades 5-8 about the history, detection, extraction, transportation, use, environmental problem/solutions, and future of fossil energy. The study of energy science shows…

  13. Gravitational-Wave Luminosity of Binary Neutron Stars Mergers

    Science.gov (United States)

    Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim

    2018-03-01

    We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.

  14. Gravitational-Wave Luminosity of Binary Neutron Stars Mergers.

    Science.gov (United States)

    Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim

    2018-03-16

    We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.

  15. Lost-in-Space Star Identification Using Planar Triangle Principal Component Analysis Algorithm

    Directory of Open Access Journals (Sweden)

    Fuqiang Zhou

    2015-01-01

    Full Text Available It is a challenging task for a star sensor to implement star identification and determine the attitude of a spacecraft in the lost-in-space mode. Several algorithms based on triangle method are proposed for star identification in this mode. However, these methods hold great time consumption and large guide star catalog memory size. The star identification performance of these methods requires improvements. To address these problems, a star identification algorithm using planar triangle principal component analysis is presented here. A star pattern is generated based on the planar triangle created by stars within the field of view of a star sensor and the projection of the triangle. Since a projection can determine an index for a unique triangle in the catalog, the adoption of the k-vector range search technique makes this algorithm very fast. In addition, a sharing star validation method is constructed to verify the identification results. Simulation results show that the proposed algorithm is more robust than the planar triangle and P-vector algorithms under the same conditions.

  16. Symmetry energy and neutron star properties in the saturated Nambu–Jona-Lasinio model

    Directory of Open Access Journals (Sweden)

    Si-Na Wei

    2016-12-01

    Full Text Available In this work, we adopt the Nambu–Jona-Lasinio (NJL model that ensures the nuclear matter saturation properties to study the density dependence of the symmetry energy. With the interactions constrained by the chiral symmetry, the symmetry energy shows novel characters different from those in conventional mean-field models. First, the negative symmetry energy at high densities that is absent in relativistic mean-field (RMF models can be obtained in the RMF approximation by introducing a chiral isovector–vector interaction, although it would be ruled out by the neutron star (NS stability. Second, with the inclusion of the isovector–scalar interaction the symmetry energy exhibits a general softening at high densities even for the large slope parameter of the symmetry energy. The NS properties obtained in the present NJL model can be in accord with the observations. The NS maximum mass obtained with various isovector–scalar couplings and momentum cutoffs is well above the 2M⊙, and the NS radius obtained well meets the limits extracted from recent measurements. In particular, the significant reduction of the canonical NS radius occurs with the moderate decrease of the slope of the symmetry energy.

  17. Observations of the Star Cor Caroli at the Apple Valley Workshop 2016 (Abstract)

    Science.gov (United States)

    Estrada, R.; Boyd, S.; Estrada, C.; Evans, C.; Rhoades, H.; Rhoades, M.; Rhoades, T.

    2017-12-01

    (Abstract only) Using a 22-inch Newtonian Alt/Az telescope and Celestron Micro Guide eyepiece, students participating in a workshop observed the binary star Cor Caroli (STF 1692; alpha CVn) and found a position angle of 231.0 degrees as well as an average separation of 18.7" This observation compared favorably with the 2015 Washington Double Star published position. This project was part of Mark Brewer's Apple Valley Double Star Workshop. The results were analyzed using bias and circle error probability calculations.

  18. Ultraviolet energy distributions and the temperatures of peculiar B and A stars

    International Nuclear Information System (INIS)

    Adelman, S.J.; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1985-01-01

    Color temperatures have been estimated by comparing ultraviolet observations of HgMn and magnetic Ap stars with those of normal stars. Ultraviolet data from the OAO-2, ANS, TD-1, and IUE satellites generally give similar results. The values for the normal stars were derived from comparison of fluxes predicted by solar-composition fully line-blanketed model atmospheres with optical region spectrophotometry. The ultraviolet temperatures of the HgMn stars cover a narrower temperature range than do their optical region values. Magnetic Ap stars with similar optical region temperatures can show substantial differences in their ultraviolet color temperatures. This may result from magnetic field configuration and abundance differences. 27 references

  19. Chaplygin dark star

    International Nuclear Information System (INIS)

    Bertolami, O.; Paramos, J.

    2005-01-01

    We study the general properties of a spherically symmetric body described through the generalized Chaplygin equation of state. We conclude that such an object, dubbed generalized Chaplygin dark star, should exist within the context of the generalized Chaplygin gas (GCG) model of unification of dark energy and dark matter, and derive expressions for its size and expansion velocity. A criteria for the survival of the perturbations in the GCG background that give origin to the dark star are developed, and its main features are analyzed

  20. New CO and HCN sources associated with IRAS carbon stars

    Science.gov (United States)

    NGUYEN-Q-RIEU; Epchtein, N.; TRUONG-BACH; Cohen, M.

    1987-01-01

    Emission of CO and HCN was detected in 22 out of a sample of 53 IRAS sources classified as unidentified carbon-rich objects. The sample was selected according to the presence of the silicon carbide feature as revealed by low-resolution spectra. The molecular line widths indicate that the CO and HCN emission arises from the circumstellar envelopes of very highly evolved stars undergoing mass loss. The visible stars tend to be deficient in CO as compared with unidentified sources. Most the detected CO and HCN IRAS stars are distinct and thick-shelled objects, but their infrared and CO luminosities are similar to those of IRC + 102156 AFGL and IRC-CO evolved stars. The 12 micron flux seems to be a good indicator of the distance, hence a guide for molecular searches.

  1. Guide to UK renewable energy companies 2001. 6. ed.

    International Nuclear Information System (INIS)

    2001-01-01

    This 2001 edition of the guide to UK renewable companies and equipment and service providers presents summaries of the different industry sectors covering wind power, photovoltaics, solar water heating, geothermal heat pump, hydroelectric power, marine current and wave technology, bioenergy, power generation from landfill gas, energy from waste, and cogeneration. A UK company classification listing and index is provided along with listing of UK organisations and companies and an index of advertisers

  2. The fluorine destruction in stars: First experimental study of the 19F(p,α)16O reaction at astrophysical energies

    International Nuclear Information System (INIS)

    La Cognata, M.; Mukhamedzhanov, A.; Spitaleri, C.; Indelicato, I.; Aliotta, M.; Burjan, V.; Cherubini, S.; Coc, A.; Gulino, M.; Hons, Z.; Kiss, G. G.; Kroha, V.; Lamia, L.; Mrazek, J.; Palmerini, S.; Piskor, S.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.

    2012-01-01

    The 19 F(p,α) 16 O reaction is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars and it might also play a role in hydrogendeficient post-AGB star nucleosynthesis. So far, available direct measurements do not reach the energy region of astrophysical interest (E cm ∼ 300 keV), because of the hindrance effect of the Coulomb barrier. The Trojan Horse (TH) method was thus used to access this energy region, by extracting the quasi-free contribution to the 2 H( 19 F,α 16 O)n reaction. The TH measurement of the α 0 channel, which is the dominant one at such energies, shows the presence of resonant structures not observed before that cause an increase of the reaction rate at astrophysical temperatures up to a factor of 1.7, with potential important consequences for stellar nucleosynthesis.

  3. Strangeon and Strangeon Star

    Science.gov (United States)

    Xiaoyu, Lai; Renxin, Xu

    2017-06-01

    The nature of pulsar-like compact stars is essentially a central question of the fundamental strong interaction (explained in quantum chromo-dynamics) at low energy scale, the solution of which still remains a challenge though tremendous efforts have been tried. This kind of compact objects could actually be strange quark stars if strange quark matter in bulk may constitute the true ground state of the strong-interaction matter rather than 56Fe (the so-called Witten’s conjecture). From astrophysical points of view, however, it is proposed that strange cluster matter could be absolutely stable and thus those compact stars could be strange cluster stars in fact. This proposal could be regarded as a general Witten’s conjecture: strange matter in bulk could be absolutely stable, in which quarks are either free (for strange quark matter) or localized (for strange cluster matter). Strange cluster with three-light-flavor symmetry is renamed strangeon, being coined by combining “strange nucleon” for the sake of simplicity. A strangeon star can then be thought as a 3-flavored gigantic nucleus, and strangeons are its constituent as an analogy of nucleons which are the constituent of a normal (micro) nucleus. The observational consequences of strangeon stars show that different manifestations of pulsarlike compact stars could be understood in the regime of strangeon stars, and we are expecting more evidence for strangeon star by advanced facilities (e.g., FAST, SKA, and eXTP).

  4. Life and death of the stars

    CERN Document Server

    Srinivasan, Ganesan

    2014-01-01

    This volume is devoted to one of the fascinating things about stars: how they evolve as they age. This evolution is different for stars of different masses. How stars end their lives when their supply of energy is exhausted also depends on their masses. Interestingly, astronomers conjectured about the ultimate fate of the stars even before the details of their evolution became clear. Part I of this book gives an account of the remarkable predictions made during the 1920s and 1930s concerning the ultimate fate of stars. Since much of this development hinged on quantum physics that emerged during this time, a detailed introduction to the relevant physics is included in the book. Part II is a summary of the life history of stars. This discussion is divided into three parts: low-mass stars, like our Sun, intermediate-mass stars, and massive stars. Many of the concepts of contemporary astrophysics were built on the foundation erected by Subrahmanyan Chandrasekhar in the 1930s. This book, written during his birth c...

  5. Advancing adaptive optics technology: Laboratory turbulence simulation and optimization of laser guide stars

    Science.gov (United States)

    Rampy, Rachel A.

    optimizing the laser beacons used to bring AO correction to parts of the sky that lack a naturally bright light source for measuring atmospheric distortion. Long pulse length laser guide stars (LGS) that use fluorescence from the D 2 transition in mesospheric sodium are valuable both due to their high altitude, and because they permit Rayleigh blanking and fratricide avoidance in multiple LGS systems. Bloch equation simulations of sodium-light interactions in Mathematica show that certain spectral formats and pulse lengths (on the order of 30 μs), with high duty cycles (20-50%), should be able to achieve photon returns within 10% of what is seen from continuous wave (CW) excitation. Utilizing this recently developed code (called LGSBloch), I investigated the time dependent characteristics of sodium fluorescence. I then identified the optimal format for the new LGS that will be part of the upgrade to the AO system on the Shane 3 meter telescope at the Lick Observatory. I discuss these results, along with their general applicability to other LGS systems, and provide a brief description of the potential benefits of uplink correction. Predictions from the LGSBloch simulation package are compared to data from currently operating LGS systems. For a CW LGS, the return flux measurements and theory show reasonable agreement, but for short pulse lasers, such as those at the Lick and Keck Observatories, the code seems to be overestimating the data by a factor of 2--3. Several tactics to explicate this discrepancy are explored, such as verifying parameters involved in the measurements and including greater detail in the modeling. Although these efforts were unsuccessful at removing the discrepancy, they illuminated other facets of the problem that deserve further consideration. Use of the sophisticated LGSBloch model has allowed detailed study of the evolution of the energy level populations and other physical effects (e.g. Larmor precession, atomic recoil, and collisions). This has

  6. 2013 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2012-01-01

    Compact, easy to use and reliable, this popular guide contains everything you need to know about the southern night sky with monthly star maps, diagrams and details of all the year's exciting celestial events. Wherever you are in Australia or New Zealand, easy calculations allow you to determine when the Sun, Moon and planets will rise and set throughout the year. Also included is information on the latest astronomical findings from space probes and telescopes around the world. The Sky guide has been published annually by the Powerhouse Museum, Sydney, since 1991. It is recommended for photogr

  7. Photoionization-regulated star formation and the structure of molecular clouds

    Science.gov (United States)

    Mckee, Christopher F.

    1989-01-01

    A model for the rate of low-mass star formation in Galactic molecular clouds and for the influence of this star formation on the structure and evolution of the clouds is presented. The rate of energy injection by newly formed stars is estimated, and the effect of this energy injection on the size of the cloud is determined. It is shown that the observed rate of star formation appears adequate to support the observed clouds against gravitational collapse. The rate of photoionization-regulated star formation is estimated and it is shown to be in agreement with estimates of the observed rate of star formation if the observed molecular cloud parameters are used. The mean cloud extinction and the Galactic star formation rate per unit mass of molecular gas are predicted theoretically from the condition that photionization-regulated star formation be in equilibrium. A simple model for the evolution of isolated molecular clouds is developed.

  8. Guide to purchasing green power. Renewable electricity, renewable energy certificates and on-site renewable generation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-09-30

    The Guide to Purchasing Green Power is intended for organizations that are considering the merits of buying green power as well as those that have decided to buy it and want help doing so. The Guide was written for a broad audience, including businesses, government agencies, universities, and all organizations wanting to diversify their energy supply and to reduce the environmental impact of their electricity use.The Guide provides an overview of green power markets and describes the necessary steps to buying green power. This section summarizes the Guide to help readers find the information they need.

  9. Overview Michelin Star Reputation Restaurant in Hospitality Industry

    Directory of Open Access Journals (Sweden)

    Agung Gita Subakti

    2013-05-01

    Full Text Available For most chefs and Restaurateur, having his restaurant being awarded one or more stars in the famous Michelin Guide Rouge represents a major achievement, recognition of their work, and also important publicity generating increased notoriety. In this specific industry, experts play a decisive role, and reputation of restaurants and chefs are basically established according to their opinions. The aim of this paper is to overview some of the Restaurants achieving the Michelin Star Reputation and able to sustain it for years. Moreover, how these reputations are made and to understand better the development of gaining such a high reputation.

  10. Thirteen-colour photometry of Be stars

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, M; Schuster, W J [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

    1981-01-01

    Thirteen-colour photometry made at the San Pedro Martir Observatory in Baja California, for a number of spectroscopically variable Be and shell stars is presented. Several of these stars also show photometric variability in the ultraviolet and/or infrared over a time base of two to three years. We analyze the more interesting stars in terms of colour-colour diagrams, colour excesses, spectral characteristics and changes in their energy distributions. Prospects for future research are discussed.

  11. Thirteen-colour photometry of Be stars

    International Nuclear Information System (INIS)

    Alvarez, M.; Schuster, W.J.

    1981-01-01

    Thirteen-colour photometry made at the San Pedro Martir Observatory in Baja California, for a number of spectroscopically variable Be and shell stars is presented. Several of these stars also show photometric variability in the ultraviolet and/or infrared over a time base of two to three years. We analyze the more interesting stars in terms of colour-colour diagrams, colour excesses, spectral characteristics and changes in their energy distributions. Prospects for future research are discussed. (author)

  12. STAR facility tritium accountancy

    International Nuclear Information System (INIS)

    Pawelko, R. J.; Sharpe, J. P.; Denny, B. J.

    2008-01-01

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5 g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed. (authors)

  13. The Department of Energy`s Rocky Flats Plant: A guide to record series useful for health-related research. Volume VII. Employee occupational exposure and health

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This is the seventh in a series of seven volumes which constitute a guide to records of the Rocky Flats Plant useful for conducting health-related research. The primary purpose of Volume VII is to describe record series pertaining to employee occupational exposure and health at the Department of Energy`s (DOE) Rocky Flats Plant, now named the Rocky Flats Environmental Technology Site, near Denver, Colorado. History Associates Incorporated (HAI) prepared this guide as part of its work as the support services contractor for DOE`s Epidemiologic Records Inventory Project. This introduction briefly describes the Epidemiologic Records Inventory Project and HAI`s role in the project, provides a history of occupational exposure monitoring and health practices at Rocky Flats, and identifies organizations contributing to occupational exposure monitoring and health policies and activities. Other topics include the scope and arrangement of the guide and the organization to contact for access to these records. Comprehensive introductory and background information is available in Volume 1. Other volumes in the guide pertain to administrative and general subjects, facilities and equipment, production and materials handling, environmental and workplace monitoring, and waste management. In addition, HAI has produced a subject-specific guide, titled The September 1957 Rocky Flats Fire: A Guide to Record Series of the Department of Energy and Its Contractors, which researchers should consult for further information about records related to this incident.

  14. Massive stars and the energy balance of the ISM: I. The imapct of an isolated 60 M star

    Science.gov (United States)

    Yorke, H. W.; Freyer, T.; Hensler, G.

    2002-01-01

    We present results of numerical simulations carried out with a 2D radiation hydrodynamics code in order to study the impact of massive stars on their surrounding interstellar medium. This first paper deals with the evolution of the circumstellar gas around an isolated 60 M star.

  15. Astronomy: A Self-Teaching Guide, 6th Edition

    Science.gov (United States)

    Moché, Dinah L.

    2004-02-01

    "A lively, up-to-date account of the basic principles of astronomy and exciting current field of research."-Science Digest For a quarter of a century, Astronomy: A Self-Teaching Guide has been making students and amateur stargazers alike feel at home among the stars. From stars, planets and galaxies, to black holes, the Big Bang and life in space, this title has been making it easy for beginners to quickly grasp the basic concepts of astronomy for over 25 years. Updated with the latest discoveries in astronomy and astrophysics, this newest edition of Dinah Moché's classic guide now includes many Web site addresses for spectacular images and news. And like all previous editions, it is packed with valuable tables, charts, star and moon maps and features simple activities that reinforce readers' grasp of basic concepts at their own pace, as well as objectives, reviews, and self-tests to monitor their progress. Dinah L. Moché, PhD (Rye, NY), is an award-winning author, educator, and lecturer. Her books have sold over nine million copies in seven languages.

  16. BPS Skyrmions as neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Adam, C., E-mail: adam@fpaxp1.usc.es [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Naya, C.; Sanchez-Guillen, J.; Vazquez, R. [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Reymonta 4, Kraków (Poland)

    2015-03-06

    The BPS Skyrme model has been demonstrated already to provide a physically intriguing and quantitatively reliable description of nuclear matter. Indeed, the model has both the symmetries and the energy–momentum tensor of a perfect fluid, and thus represents a field theoretic realization of the “liquid droplet” model of nuclear matter. In addition, the classical soliton solutions together with some obvious corrections (spin–isospin quantization, Coulomb energy, proton-neutron mass difference) provide an accurate modeling of nuclear binding energies for heavier nuclei. These results lead to the rather natural proposal to try to describe also neutron stars by the BPS Skyrme model coupled to gravity. We find that the resulting self-gravitating BPS Skyrmions provide excellent results as well as some new perspectives for the description of bulk properties of neutron stars when the parameter values of the model are extracted from nuclear physics. Specifically, the maximum possible mass of a neutron star before black-hole formation sets in is a few solar masses, the precise value of which depends on the precise values of the model parameters, and the resulting neutron star radius is of the order of 10 km.

  17. RFA-based 589-nm guide star lasers for ESO VLT: a paradigm shift in performance, operational simplicity, reliability, and maintenance

    Science.gov (United States)

    Friedenauer, Axel; Karpov, Vladimir; Wei, Daoping; Hager, Manfred; Ernstberger, Bernhard; Clements, Wallace R. L.; Kaenders, Wilhelm G.

    2012-07-01

    Large telescopes equipped with adaptive optics require 20-25W CW 589-nm sources with emission linewidths of ~5 MHz. These Guide Star (GS) lasers should also be highly reliable and simple to operate and maintain for many years at the top of a mountain facility. Under contract from ESO, industrial partners TOPTICA and MPBC are nearing completion of the development of GS lasers for the ESO VLT, with delivery of the first of four units scheduled for December 2012. We report on the design and performance of the fully-engineered Pre-Production Unit (PPU), including system reliability/availability analysis, the successfully-concluded qualification testing, long-term component and system level tests and long-term maintenance and support planning. The chosen approach is based on ESO's patented narrow-band Raman Fiber Amplifier (EFRA) technology. A master oscillator signal from a linearly-polarized TOPTICA 20-mW, 1178-nm CW diode laser, with stabilized emission frequency and controllable linewidth up to a few MHz, is amplified in an MPBC polarization-maintaining (PM) RFA pumped by a high-power 1120-nm PM fiber laser. With efficient stimulated Brillouin scattering suppression, an unprecedented 40W of narrow-band RFA output has been obtained. This is then mode-matched into a resonant-cavity doubler with a free-spectral-range matching the sodium D2a to D2b separation, allowing simultaneous generation of an additional frequency component (D2b line) to re-pump the sodium atom electronic population. With this technique, the return flux can be increased without having to resort to electro-optical modulators and without the risk of introducing optical wave front distortions. The demonstrated output powers with doubling efficiencies >80% at 589 nm easily exceed the 20W design goal and require less than 700 W of electrical power. In summary, the fiber-based guide star lasers provide excellent beam quality and are modular, turn-key, maintenance-free, reliable, efficient, and ruggedized

  18. Hot mantles, moderate photospheres for Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Underhill, A.B.

    1982-01-01

    The amount of continuous energy from Wolf-Rayet stars and the shape of the continuous spectrum from the ultraviolet to the near infrared correspond to effective temperatures in the range 25000 to 30000 K. The value of log g is of the order of 4.0 +- 0.5. Thus the photospheres of Wolf-Rayet stars correspond to those of moderately hot stars. The line spectra of Wolf-Rayet stars, however, indicate that electron temperatures greater than 30000 K occur in the outer atmospheres or mantles of these stars. Here outflow is important. (Auth.)

  19. STAR-H2: a battery-type lead-cooled fast reactor for hydrogen manufacture in a sustainable hierarchical hub-spoke energy infrastructure

    International Nuclear Information System (INIS)

    Wade, D.C.; Doctor, R. D.; Peddicord, K.L.

    2003-01-01

    The Secure Transportable Autonomous Reactor for Hydrogen production STAR-H2 is designed to fit into a sustainable global, mid-21st century hierarchical hub-spoke nuclear energy supply architecture based on nuclear fuel, hydrogen, and electricity energy carriers and having favorable energy security, ecological and nonproliferation features. It will produce hydrogen, oxygen and potable water to service cities and their surrounding regions under an assumed electrical generation network based on fuel cells and microturbines and an assumed transportation sector using hydrogen fueled vehicles. STAR-H2 is a long refueling interval (Battery) turnkey heat supply reactor intended for production of hydrogen by thermochemical water cracking. The reactor is a Pb-cooled, mixed U-TRU-Nitride-fueled, fast spectrum reactor delivering 400 MW th of heat at 800degC core outlet temperature. The primary coolant circulates by natural circulation; the 400 MW th heat rating is set by dual requirements for natural circulation; the 400 MW th heat rating is set by dual requirements for natural circulation and for rail shippability of the vessel. An intermediate low pressure He loop carries the heat to a Ca-Br thermochemical water cracking cycle for the manufacture of H 2 (and O 2 ). The water cracking cycle rejects heat at 550degC and that heat is used in a supercritical CO 2 Brayton cycle turbogenerator to provide hotel load electricity. A thermal desalinisation plant receives discharge heat at 125degC from the Brayton cycle and the brine provides for ultimate heat rejection from the cascaded thermodynamic cycles. The modified UT-3 cycle used in STAR-H2, called the Ca-Br cycle, operates at atmospheric pressure and 750-725degC, uses solid/gas separation steps and achieves about 44% efficiency. Unlike UT-3, it employs a single-stage HBr-dissociation step based on a plasma chemistry technique operating near ambient conditions. The STAR-H2 power plant will operate on a 20 year refueling interval

  20. Tracking and trailing. A travel guide for the energy transition

    International Nuclear Information System (INIS)

    Hekkenberg, M.; Londo, M.

    2011-09-01

    Our energy system, which is one of the pillars of the Dutch society, will probably be subjected to drastic changes in the coming decades. It will become a difficult and painful process at times. Policy makers have the task of directing these changes with a clear view on opportunities and threats. This guide aims to offer Dutch policy makers some strategic insights and tools. [nl

  1. Symbiotic stars observed from the IRAS satellite

    International Nuclear Information System (INIS)

    Luud, L.; Tuvikene, T.

    1987-01-01

    Symbiotic stars according to Alfven's catalogue have been checked for coincidence with the IRAS-observed for-infrared sources. 72 symbiotic and possible symbiotic stars have been identified with the IRAS-observed sources. A catalogue of identified stars and energy distributions of representative stars are given. It turns out that the dust in symbiotic stars is a more widespread phenomenon than that it was believed before. Almost 40% of systems are the dusty ones. Among objects with dust temperature some tens of K have been found. It is shown that the only useful two-color diagram is (K-m 12 )-(m 12 -m 25 ). Attention is paid to a type of symbiotic stars with G spectral class cold component which needs special investigation

  2. The Nuclear Spectroscopic Telescope Array (NuSTAR)

    DEFF Research Database (Denmark)

    Harrison, Fiona A.; Boggs, Steve; Christensen, Finn Erland

    2010-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing hard X-ray (6 - 80 keV) telescope to orbit. NuSTAR will offer a factor 50 - 100 sensitivity improvement compared to previous collimated or coded mask imagers that have operated...... in this energy band. In addition, NuSTAR provides sub-arcminute imaging with good spectral resolution over a 12-arcminute eld of view. After launch, NuSTAR will carry out a two-year primary science mission that focuses on four key programs: studying the evolution of massive black holes through surveys carried...... on-orbit deployment of an extendable mast. An aspect and alignment metrology system enable reconstruction of the absolute aspect and variations in the telescope alignment resulting from mast exure during ground data processing. Data will be publicly available at GSFC's High Energy Archive Research...

  3. Achieving 50% Energy Savings in New Schools, Advanced Energy Design Guides: K-12 Schools (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-09-01

    This fact sheet summarizes recommendations for designing elementary, middle, and high school buildings that will result in 50% less energy use than conventional new schools built to minimum code requirements. The recommendations are drawn from the Advanced Energy Design Guide for K-12 School Buildings, an ASHRAE publication that provides comprehensive recommendations for designing low-energy-use school buildings (see sidebar). Designed as a stand-alone document, this fact sheet provides key principles and a set of prescriptive design recommendations appropriate for smaller schools with insufficient budgets to fully implement best practices for integrated design and optimized performance. The recommendations have undergone a thorough analysis and review process through ASHRAE, and have been deemed the best combination of measures to achieve 50% savings in the greatest number of schools.

  4. Emerging anisotropic compact stars in f(G,T) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Shamir, M.F.; Ahmad, Mushtaq [National University of Computer and Emerging Sciences, Lahore (Pakistan)

    2017-10-15

    The possible emergence of compact stars has been investigated in the recently introduced modified Gauss-Bonnet f(G,T) gravity, where G is the Gauss-Bonnet term and T is the trace of the energy-momentum tensor (Sharif and Ikram, Eur Phys J C 76:640, 2016). Specifically, for this modified f(G,T) theory, the analytic solutions of Krori and Barua have been applied to an anisotropic matter distribution. To determine the unknown constants appearing in the Krori and Barua metric, the well-known three models of the compact stars, namely 4U1820-30, Her X-I, and SAX J 1808.4-3658 have been used. The analysis of the physical behaviour of the compact stars has been presented and the physical features like energy density and pressure, energy conditions, static equilibrium, stability, measure of anisotropy, and regularity of the compact stars, have been discussed. (orig.)

  5. Dwarf Star Erupts in Giant Flare

    Science.gov (United States)

    2005-01-01

    This movie taken by NASA'S Galaxy Evolution Explorer shows one of the largest flares, or star eruptions, ever recorded at ultraviolet wavelengths. The star, called GJ 3685A, just happened to be in the Galaxy Evolution Explorer's field of view while the telescope was busy observing galaxies. As the movie demonstrates, the seemingly serene star suddenly exploded once, then even more intensely a second time, pouring out in total about one million times more energy than a typical flare from our Sun. The second blast of light constituted an increase in brightness by a factor of at least 10,000. Flares are huge explosions of energy stemming from a single location on a star's surface. They are caused by the brief destruction of a star's magnetic fields. Many types of stars experience them, though old, small, rapidly rotating 'red dwarfs' like GJ 3685A tend to flare more frequently and dramatically. These stars, called flare stars, can experience powerful eruptions as often as every few hours. Younger stars, in general, also erupt more often. One of the reasons astronomers study flare stars is to gain a better picture and history of flare events taking place on the Sun. A preliminary analysis of the GJ 3685A flare shows that the mechanisms underlying stellar eruptions may be more complex than previously believed. Evidence for the two most popular flare theories was found. Though this movie has been sped up (the actual flare lasted about 20 minutes), time-resolved data exist for each one-hundredth of a second. These observations were taken at 2 p.m. Pacific time, April 24, 2004. In the still image, the time sequence starts in the upper left panel, continues in the upper right, then moves to the lower left and ends in the lower right. The circular and linear features that appear below and to the right of GJ 3685A during the flare event are detector artifacts caused by the extreme brightness of the flare.

  6. Young Star Cluster Found Aglow With Mysterious X-Ray Cloud

    Science.gov (United States)

    2002-12-01

    A mysterious cloud of high-energy electrons enveloping a young cluster of stars has been discovered by astronomers using NASA's Chandra X-ray Observatory. These extremely high-energy particles could cause dramatic changes in the chemistry of the disks that will eventually form planets around stars in the cluster. Known as RCW 38, the star cluster covers a region about 5 light years across. It contains thousands of stars formed less than a million years ago and appears to be forming new stars even today. The crowded environment of a star cluster is thought to be conducive to the production of hot gas, but not high-energy particles. Such particles are typically produced by exploding stars, or in the strong magnetic fields around neutron stars or black holes, none of which is evident in RCW 38. "The RCW 38 observation doesn't agree with the conventional picture," said Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, lead author of an Astrophysical Journal Letters paper describing the Chandra observation. "The data show that somehow extremely high-energy electrons are being produced there, although it is not clear how." RCW 38 RCW 38 X-ray, Radio, Infrared Composite Electrons accelerated to energies of trillions of volts are required to account for the observed X-ray spectrum of the gas cloud surrounding the ensemble of stars, which shows an excess of high-energy X-rays. As these electrons move in the magnetic field that threads the cluster, they produce X-rays. One possible origin for the high-energy electrons is a previously undetected supernova that occurred in the cluster. Although direct evidence for the supernova could have faded away thousands of years ago, a shock wave or a rapidly rotating neutron star produced by the outburst could be acting in concert with stellar winds to produce the high-energy electrons. "Regardless of the origin of the energetic electrons," said Wolk, "their presence would change the chemistry of proto

  7. The Sun among the stars. Pt. 3

    International Nuclear Information System (INIS)

    Hardorp, J.

    1980-01-01

    Energy distributions from 3308 to 8390 Angstroem of two candidates for a solar spectral analog and of 14 other northern G-type dwarfs are compared to the solar energy distribution via stellar spectrophotometric standards. The reliability of the stellar and solar flux-calibrations is evaluated. While the stellar calibration seems to be in good shape, solar calibrations differ widely. Labs.and Neckel's calibration is the best match to the energy distributions from 4500 to 8390 Angstroem of those four stars that share the Sun's ultraviolet line spectrum (16 Cyg B, G5V, and the three Hyades stars VB 64, 106, and 142). Below 4500 Angstroem, discrepancies of up to 6% remain which do not seem to be genuine Sun-star differences. An error in the Labs and Neckel tables between 5700 and 6000 Angstroem is corrected. The NASA Standard Tables of Solar Spectral Irradiance cannot be trusted, since there seems to be no star in the sky that look like the NASA-sun. The four stars mentioned are taken to be perfect solar spectral analogs. An improved table of solar spectral irradiance is then given by the magnitudes of 16 Cyg B minus 32.945, based on Tueg's atellar and Labs and Neckel's solar calibrations. The Sun's place in the UBV system is V = -26.71 +- 0.03, B-V = 0.665 +- 0.005, and U-B = 0.20 +- 0.01. Most previous photometric investigations found a bluer Sun because they used the wrong solar calibration. For deriving accurate albedos of planets, any one of the calibrated G-type stars can be used as a standard star, when corrections are applied, although the solar analogs themselves are to be preferred. The MK system of spectral classification should be revised. (orig.)

  8. Close binary star type x-ray star and its mechanism of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, R [Rikkyo Univ., Tokyo (Japan). Dept. of Physics

    1975-09-01

    Recent progress of the study of an X-ray star is described. In 1970, the periodical emission of pulsed X-rays from Cen X-3 and Her X-1 was observed. An optically corresponding celestial object for the Cen X-3 was reported in 1973, and the mass of Cen X-3 was revised. The optical object was named after Krzeminsky. From the observed variation of luminosity, it is said that the Krzeminsky's star is deformed. This fact gave new data on the mass of the Cen X-3, and the mass is several times as large as the previously estimated value. The behavior of the Her X-1 shows four kinds of clear time variation, and indicates the characteristics of an X-ray star. The Her X-1 is an X-ray pulser the same as Cen X-3, and is a close binary star. The opposite star is known as HZ-Her, and shows weaker luminosity than the intensity of X-ray from the Her X-1. Thirty-five day period was seen in the intensity variation of X-ray. The mechanism of X-ray pulsing can be explained by material flow into a neutron star. The energy spectrum from Her X-1 is different from that from the Cen X-3. Another X-ray star, Cyg X-1, is considered to be a black hole from its X-ray spectrum.

  9. Neutron star evolution and emission

    Science.gov (United States)

    Epstein, R. I.; Edwards, B. C.; Haines, T. J.

    1997-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.

  10. The Productivity of Oxygenic Photosynthesis around Cool, M Dwarf Stars

    Science.gov (United States)

    Lehmer, Owen R.; Catling, David C.; Parenteau, Mary N.; Hoehler, Tori M.

    2018-06-01

    In the search for life around cool stars, the presence of atmospheric oxygen is a prominent biosignature, as it may indicate oxygenic photosynthesis (OP) on the planetary surface. On Earth, most oxygenic photosynthesizing organisms (OPOs) use photons between 400 and 750 nm, which have sufficient energy to drive the photosynthetic reaction that generates O2 from H2O and CO2. OPOs around cool stars may evolve similar biological machinery capable of producing oxygen from water. However, in the habitable zones (HZs) of the coolest M dwarf stars, the flux of 400–750 nm photons may be just a few percent that of Earth’s. We show that the reduced flux of 400–750 nm photons around M dwarf stars could result in Earth-like planets being growth limited by light, unlike the terrestrial biosphere, which is limited by nutrient availability. We consider stars with photospheric temperatures between 2300 and 4200 K and show that such light-limited worlds could occur at the outer edge of the HZ around TRAPPIST-1-like stars. We find that even if OP can use photons longer than 750 nm, there would still be insufficient energy to sustain the Earth’s extant biosphere throughout the HZ of the coolest stars. This is because such stars emit largely in the infrared and near-infrared, which provide sufficient energy to make the planet habitable, but limits the energy available for OP. TRAPPIST-1f and g may fall into this category. Biospheres on such planets, potentially limited by photon availability, may generate small biogenic signals, which could be difficult for future observations to detect.

  11. Biology Students Building Computer Simulations Using StarLogo TNG

    Science.gov (United States)

    Smith, V. Anne; Duncan, Ishbel

    2011-01-01

    Confidence is an important issue for biology students in handling computational concepts. This paper describes a practical in which honours-level bioscience students simulate complex animal behaviour using StarLogo TNG, a freely-available graphical programming environment. The practical consists of two sessions, the first of which guides students…

  12. On neutron stars and gravitation

    International Nuclear Information System (INIS)

    Castagnino, M.A.

    1987-01-01

    From the variational principle for the total internal energy of a neutron star and some restrictions of the form of the metric coefficients, equations of structure which are valid for every metric theory of gravitation have been found. Some simple solutions of the structure equations to find the maximum mass of a neutron star are also presented. Finally it is studied this problem using a post post-Newtonian parametrization

  13. Technical Support Document: Development of the Advanced Energy Design Guide for Large Hospitals - 50% Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, E.; Leach, M.; Pless, S.

    2013-06-01

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Large Hospitals: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-LH) ASHRAE et al. (2011b). The AEDG-LH is intended to provide recommendations for achieving 50% whole-building energy savings in large hospitals over levels achieved by following Standard 90.1-2004. The AEDG-LH was created for a 'standard' mid- to large-size hospital, typically at least 100,000 ft2, but the strategies apply to all sizes and classifications of new construction hospital buildings. Its primary focus is new construction, but recommendations may be applicable to facilities undergoing total renovation, and in part to many other hospital renovation, addition, remodeling, and modernization projects (including changes to one or more systems in existing buildings).

  14. Pulsating stars

    CERN Document Server

    Catelan, M?rcio

    2014-01-01

    The most recent and comprehensive book on pulsating stars which ties the observations to our present understanding of stellar pulsation and evolution theory.  Written by experienced researchers and authors in the field, this book includes the latest observational results and is valuable reading for astronomers, graduate students, nuclear physicists and high energy physicists.

  15. Limiting rotational period of neutron stars

    Science.gov (United States)

    Glendenning, Norman K.

    1992-11-01

    We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442Msolar neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars.

  16. Limiting rotational period of neutron stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1992-01-01

    We seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties in which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass shedding would occur, is 0.33 ms for a M=1.442M circle-dot neutron star (the mass of PSR1913+16). A still lower curve, based only on the structure of Einstein's equations, limits any star whatsoever to lie in the plane above it. Hypothetical stars such as strange stars, if the matter of which they are made is self-bound in bulk at a sufficiently large equilibrium energy density, can lie in the region above the general-relativistic forbidden region, and in the region forbidden to neutron stars

  17. Supernovae, compact stars and nuclear physics

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-01-01

    We briefly review the current understanding of supernova. We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 12 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to plausibly consist of individual hadrons. We conclude that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, cannot be a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation under appropriate conditions. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 39 refs., 8 figs., 2 tabs

  18. Quark Deconfinement in Rotating Neutron Stars

    Directory of Open Access Journals (Sweden)

    Richard D. Mellinger

    2017-01-01

    Full Text Available In this paper, we use a three flavor non-local Nambu–Jona-Lasinio (NJL model, an improved effective model of Quantum Chromodynamics (QCD at low energies, to investigate the existence of deconfined quarks in the cores of neutron stars. Particular emphasis is put on the possible existence of quark matter in the cores of rotating neutron stars (pulsars. In contrast to non-rotating neutron stars, whose particle compositions do not change with time (are frozen in, the type and structure of the matter in the cores of rotating neutron stars depends on the spin frequencies of these stars, which opens up a possible new window on the nature of matter deep in the cores of neutron stars. Our study shows that, depending on mass and rotational frequency, up to around 8% of the mass of a massive neutron star may be in the mixed quark-hadron phase, if the phase transition is treated as a Gibbs transition. We also find that the gravitational mass at which quark deconfinement occurs in rotating neutron stars varies quadratically with spin frequency, which can be fitted by a simple formula.

  19. Neutron Star Physics and EOS

    Directory of Open Access Journals (Sweden)

    Lattimer James M.

    2016-01-01

    Full Text Available Neutron stars are important because measurement of their masses and radii will determine the dense matter equation of state. They will constrain the nuclear matter symmetry energy, which controls the neutron star matter pressure and the interior composition, and will influence the interpretation of nuclear experiments. Astrophysical observations include pulsar timing, X-ray bursts, quiescent low-mass X-ray binaries, pulse profiles from millisecond pulsars, neutrino observations from gravitational collapse supernovae,and gravitational radiation from compact object mergers. These observations will also constrain the neutron star interior, including the properties of superfluidity there, and determine the existence of a possible QCD phase transition.

  20. GLAS: engineering a common-user Rayleigh laser guide star for adaptive optics on the William Herschel Telescope

    Science.gov (United States)

    Talbot, Gordon; Abrams, Don Carlos; Apostolakos, Nikolaos; Bassom, Richard; Blackburn, Colin; Blanken, Maarten; Cano Infantes, Diego; Chopping, Alan; Dee, Kevin; Dipper, Nigel; Elswijk, Eddy; Enthoven, Bernard; Gregory, Thomas; ter Horst, Rik; Humphreys, Ron; Idserda, Jan; Jolley, Paul; Kuindersma, Sjouke; McDermid, Richard; Morris, Tim; Myers, Richard; Pico, Sergio; Pragt, Johan; Rees, Simon; Rey, Jürg; Reyes, Marcos; Rutten, René; Schoenmaker, Ton; Skvarc, Jure; Tromp, Niels; Tulloch, Simon; Veninga, Auke

    2006-06-01

    The GLAS (Ground-layer Laser Adaptive-optics System) project is to construct a common-user Rayleigh laser beacon that will work in conjunction with the existing NAOMI adaptive optics system, instruments (near IR imager INGRID, optical integral field spectrograph OASIS, coronagraph OSCA) and infrastructure at the 4.2-m William Herschel Telescope (WHT) on La Palma. The laser guide star system will increase sky coverage available to high-order adaptive optics from ~1% to approaching 100% and will be optimized for scientific exploitation of the OASIS integral-field spectrograph at optical wavelengths. Additionally GLAS will be used in on-sky experiments for the application of laser beacons to ELTs. This paper describes the full range of engineering of the project ranging through the laser launch system, wavefront sensors, computer control, mechanisms, diagnostics, CCD detectors and the safety system. GLAS is a fully funded project, with final design completed and all equipment ordered, including the laser. Integration has started on the WHT and first light is expected summer 2006.

  1. Ultraviolet spectrophotometry of some stars in the Orion OBI association

    International Nuclear Information System (INIS)

    Oganesyan, R.Kh.; Gasparyan, K.G.

    1980-01-01

    The results of measurements of 56 short wavelength spectra of 22 stars in the Orion OBI association obtained by means of the space observatory Orion-2 are presented. The absolute energy distribution in their continuum is obtained. The measured energy distributions in the spectra of B-type stars in the region 2150-3700 A are in good agreement with the theoretical blocking model developed by Van Citters and Morton, and those of two A-type stars with Kurucz model. It has been found that for several B-type Orion stars there exists some discrepancy between the spectral type and their effective temperature, the last one being higher than for MK spectral types. The depression in the continuous spectra of A-type stars can be explained by the blocking effect

  2. Rainbow's stars

    Energy Technology Data Exchange (ETDEWEB)

    Garattini, Remo [Universita degli Studi di Bergamo, Department of Engineering and Applied Sciences, Dalmine, Bergamo (Italy); I.N.F.N.-sezione di Milano, Milan (Italy); Mandanici, Gianluca [Universita degli Studi di Bergamo, Department of Engineering and Applied Sciences, Dalmine, Bergamo (Italy)

    2017-01-15

    In recent years, a growing interest in the equilibrium of compact astrophysical objects like white dwarf and neutron stars has been manifested. In particular, various modifications due to Planck-scale energy effects have been considered. In this paper we analyze the modification induced by gravity's rainbow on the equilibrium configurations described by the Tolman-Oppenheimer-Volkoff (TOV) equation. Our purpose is to explore the possibility that the rainbow Planck-scale deformation of space-time could support the existence of different compact stars. (orig.)

  3. Dynamics of H II regions around exiled O stars

    Science.gov (United States)

    Mackey, Jonathan; Langer, Norbert; Gvaramadze, Vasilii V.

    2013-11-01

    At least 25 per cent of massive stars are ejected from their parent cluster, becoming runaways or exiles, travelling with often-supersonic space velocities through the interstellar medium (ISM). Their overpressurized H II regions impart kinetic energy and momentum to the ISM, compress and/or evaporate dense clouds, and can constrain properties of both the star and the ISM. Here, we present one-, two- and (the first) three-dimensional simulations of the H II region around a massive star moving supersonically through a uniform, magnetized ISM, with properties appropriate for the nearby O star ζ Oph. The H II region leaves an expanding overdense shell behind the star and, inside this, an underdense wake that should be filled with hot gas from the shocked stellar wind. The gas column density in the shell is strongly influenced by the ISM magnetic field strength and orientation. Hα emission maps show that H II region remains roughly circular, although the star is displaced somewhat from the centre of emission. For our model parameters, the kinetic energy feedback from the H II region is comparable to the mechanical luminosity of the stellar wind, and the momentum feedback rate is >100 times larger than that from the wind and ≈10 times larger than the total momentum input rate available from radiation pressure. Compared to the star's eventual supernova explosion, the kinetic energy feedback from the H II region over the star's main-sequence lifetime is >100 times less, but the momentum feedback is up to 4 times larger. H II region dynamics are found to have only a small effect on the ISM conditions that a bow shock close to the star would encounter.

  4. Identification of new fluorescence processes in the UV spectra of cool stars from new energy levels of Fe II and Cr II

    Science.gov (United States)

    Johansson, Sveneric; Carpenter, Kenneth G.

    1988-01-01

    Two fluorescence processes operating in atmospheres of cool stars, symbiotic stars, and the Sun are presented. Two emission lines, at 1347.03 and 1360.17 A, are identified as fluorescence lines of Cr II and Fe II. The lines are due to transitions from highly excited levels, which are populated radiatively by the hydrogen Lyman alpha line due to accidental wavelength coincidences. Three energy levels, one in Cr II and two in Fe II, are reported.

  5. Spectrophotometry of peculiar B and A stars. I. On the detection of the lambda4200 and lambda5200 broad, continuum features of peculiar A stars

    International Nuclear Information System (INIS)

    Adelman, S.J.

    1979-01-01

    Photometric indices are used to study the broad, continuum features that are present in the energy distributions of many peculiar A stars and that may be indicators of the atmospheric structure. Values of Maitzen's Δa index, which is a measure of the lambda5200 feature, are synthesized from spectrophotometric data to examine the properties of this photometric system as well as to establish a preliminary criterion of presence for the feature. Many Ap stars definitely exhibit this feature, which normal main sequence stars lack. Two indices Δiota and Δiota* are calculated from spectrophotometry to measure the strength of the lambda4200 feature. About 90% of the Ap stars are found to have definite positive results based on the preliminary criterion of presence of the latter index. For the Ap stars there is a general tendency for Δa to increase with Δiota and Δiota*. This most likely reflects the tendency for most abundances to increase together in the Ap stars. The HgMn stars have systematically larger Δiota* and Δa values than the normal stars. This does not necessarily mean that they have the lambda4200 and lambda5200 features of the peculiar A stars. To study this question requires careful comparison of the energy distributions of the HgMn stars with those of other stars and with the predictions of model atmospheres

  6. Demonstrating the Likely Neutron Star Nature of Five M31 Globular Cluster Sources with Swift-NuSTAR Spectroscopy

    Science.gov (United States)

    Maccarone, Thomas J.; Yukita, Mihoko; Hornschemeier, Ann; Lehmer, Bret D.; Antoniou, Vallia; Ptak, Andrew; Wik, Daniel R.; Zezas, Andreas; Boyd, Padi; Kennea, Jamie; hide

    2016-01-01

    We present the results of a joint Swift-NuSTAR spectroscopy campaign on M31. We focus on the five brightest globular cluster X-ray sources in our fields. Two of these had previously been argued to be black hole candidates on the basis of apparent hard-state spectra at luminosities above those for which neutron stars are in hard states. We show that these two sources are likely to be Z-sources (i.e. low magnetic field neutron stars accreting near their Eddington limits), or perhaps bright atoll sources (low magnetic field neutron stars which are just a bit fainter than this level) on the basis of simultaneous Swift and NuSTAR spectra which cover a broader range of energies. These new observations reveal spectral curvature above 6-8 keV that would be hard to detect without the broader energy coverage the NuSTAR data provide relative to Chandra and XMM-Newton. We show that the other three sources are also likely to be bright neutron star X-ray binaries, rather than black hole X-ray binaries. We discuss why it should already have been realized that it was unlikely that these objects were black holes on the basis of their being persistent sources, and we re-examine past work which suggested that tidal capture products would be persistently bright X-ray emitters. We discuss how this problem is likely due to neglecting disc winds in older work that predict which systems will be persistent and which will be transient.

  7. Capturing Neutrinos from a Star's Final Hours

    Science.gov (United States)

    Hensley, Kerry

    2018-04-01

    What happens on the last day of a massive stars life? In the hours before the star collapses and explodes as a supernova, the rapid evolution of material in its core creates swarms of neutrinos. Observing these neutrinos may help us understand the final stages of a massive stars life but theyve never been detected.A view of some of the 1,520 phototubes within the MiniBooNE neutrino detector. Observations from this and other detectors are helping to illuminate the nature of the mysterious neutrino. [Fred Ullrich/FNAL]Silent Signposts of Stellar EvolutionThe nuclear fusion that powers stars generates tremendous amounts of energy. Much of this energy is emitted as photons, but a curious and elusive particle the neutrino carries away most of the energy in the late stages of stellar evolution.Stellar neutrinos can be created through two processes: thermal processesand beta processes. Thermal processes e.g.,pair production, in which a particle/antiparticle pair are created depend on the temperature and pressure of the stellar core. Beta processes i.e.,when a proton converts to a neutron, or vice versa are instead linked to the isotopic makeup of the stars core. This means that, if we can observe them, beta-process neutrinos may be able to tell us about the last steps of stellar nucleosynthesis in a dying star.But observing these neutrinos is not so easilydone. Neutrinos arenearly massless, neutral particles that interact only feebly with matter; out of the whopping 1060neutrinos released in a supernova explosion, even the most sensitive detectors only record the passage of just a few. Do we have a chance of detectingthe beta-process neutrinos that are released in the final few hours of a stars life, beforethe collapse?Neutrino luminosities leading up to core collapse. Shortly before collapse, the luminosity of beta-process neutrinos outshines that of any other neutrino flavor or origin. [Adapted from Patton et al. 2017]Modeling Stellar CoresTo answer this question, Kelly

  8. A COMPREHENSIVE CENSUS OF NEARBY INFRARED EXCESS STARS

    Energy Technology Data Exchange (ETDEWEB)

    Cotten, Tara H.; Song, Inseok, E-mail: tara@physast.uga.edu, E-mail: song@physast.uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

    2016-07-01

    The conclusion of the Wide-Field Infrared Survey Explorer ( WISE ) mission presents an opportune time to summarize the history of using excess emission in the infrared as a tracer of circumstellar material and exploit all available data for future missions such as the James Webb Space Telescope . We have compiled a catalog of infrared excess stars from peer-reviewed articles and perform an extensive search for new infrared excess stars by cross-correlating the Tycho-2 and all-sky WISE (AllWISE) catalogs. We define a significance of excess in four spectral type divisions and select stars showing greater than either 3 σ or 5 σ significance of excess in the mid- and far-infrared. Through procedures including spectral energy distribution fitting and various image analyses, each potential excess source was rigorously vetted to eliminate false positives. The infrared excess stars from the literature and the new stars found through the Tycho-2 and AllWISE cross-correlation produced nearly 500 “Prime” infrared excess stars, of which 74 are new sources of excess, and >1200 are “Reserved” stars, of which 950 are new sources of excess. The main catalog of infrared excess stars are nearby, bright, and either demonstrate excess in more than one passband or have infrared spectroscopy confirming the infrared excess. This study identifies stars that display a spectral energy distribution suggestive of a secondary or post-protoplanetary generation of dust, and they are ideal targets for future optical and infrared imaging observations. The final catalogs of stars summarize the past work using infrared excess to detect dust disks, and with the most extensive compilation of infrared excess stars (∼1750) to date, we investigate various relationships among stellar and disk parameters.

  9. NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1

    Energy Technology Data Exchange (ETDEWEB)

    Fürst, Felix; Grefenstette, Brian W.; Harrison, Fiona; Madsen, Kristin K.; Walton, Dominic J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Pottschmidt, Katja [Center for Space Science and Technology, University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Wilms, Jörn [Dr. Karl-Remeis-Sternwarte and ECAP, Sternwartstr. 7, D-96049 Bamberg (Germany); Tomsick, John A.; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Bachetti, Matteo [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Miller, Jon M. [Department of Astronomy, The University of Michigan, Ann Arbor, MI 48109 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Zhang, William [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 662, Greenbelt, MD 20771 (United States)

    2014-01-10

    We present NuSTAR observations of Vela X-1, a persistent, yet highly variable, neutron star high-mass X-ray binary (HMXB). Two observations were taken at similar orbital phases but separated by nearly a year. They show very different 3-79 keV flux levels as well as strong variability during each observation, covering almost one order of magnitude in flux. These observations allow, for the first time ever, investigations on kilo-second time-scales of how the centroid energies of cyclotron resonant scattering features (CRSFs) depend on flux for a persistent HMXB. We find that the line energy of the harmonic CRSF is correlated with flux, as expected in the sub-critical accretion regime. We argue that Vela X-1 has a very narrow accretion column with a radius of around 0.4 km that sustains a Coulomb interaction dominated shock at the observed luminosities of L {sub x} ∼ 3 × 10{sup 36} erg s{sup –1}. Besides the prominent harmonic line at 55 keV the fundamental line around 25 keV is clearly detected. We find that the strengths of the two CRSFs are anti-correlated, which we explain by photon spawning. This anti-correlation is a possible explanation for the debate about the existence of the fundamental line. The ratio of the line energies is variable with time and deviates significantly from 2.0, also a possible consequence of photon spawning, which changes the shape of the line. During the second observation, Vela X-1 showed a short off-state in which the power-law softened and a cut-off was no longer measurable. It is likely that the source switched to a different accretion regime at these low mass accretion rates, explaining the drastic change in spectral shape.

  10. Impacts of WIMP dark matter upon stellar evolution: main-sequence stars

    CERN Document Server

    Scott, Pat; Edsjo, Joakim

    2008-01-01

    The presence of large amounts of WIMP dark matter in stellar cores has been shown to have significant effects upon models of stellar evolution. We present a series of detailed grids of WIMP-influenced stellar models for main sequence stars, computed using the DarkStars code. We describe the changes in stellar structure and main sequence evolution which occur for masses ranging from 0.3 to 2.0 solar masses and metallicities from Z = 0.0003-0.02, as a function of the rate of energy injection by WIMPs. We then go on to show what rates of energy injection can be obtained using realistic orbital parameters for stars near supermassive black holes, including detailed considerations of dark matter halo velocity and density profiles. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits, causing WIMP annihilation to provide up to 100 times the energy of hydrogen fusion in stars at the Galactic centre.

  11. NUCLEOSYNTHESIS AND EVOLUTION OF MASSIVE METAL-FREE STARS

    International Nuclear Information System (INIS)

    Heger, Alexander; Woosley, S. E.

    2010-01-01

    The evolution and explosion of metal-free stars with masses 10-100 M sun are followed, and their nucleosynthetic yields, light curves, and remnant masses determined. Such stars would have been the first to form after the big bang and may have left a distinctive imprint on the composition of the early universe. When the supernova yields are integrated over a Salpeter initial mass function (IMF), the resulting elemental abundance pattern is qualitatively solar, but with marked deficiencies of odd-Z elements with 7 ≤ Z ≤ 13. Neglecting the contribution of the neutrino wind from the neutron stars that they form, no appreciable abundances are made for elements heavier than germanium. The computed pattern compares favorably with what has been observed in metal-deficient stars with [Z] ∼ sun ; where 1 B = 1 Bethe = 10 51 erg) for a Salpeter IMF, and may have played a role in reionizing the universe. Neglecting rotation, most of the stars end their lives as blue supergiants and form supernovae with distinctive light curves resembling SN 1987A, but some produce primary nitrogen due to dredge-up and become red supergiants. These make brighter supernovae like typical Type IIp's. For the lower mass supernovae considered, the distribution of remnant masses clusters around typical modern neutron star masses, but above 20-30 M sun , with the value depending on explosion energy, black holes are copiously formed by fallback, with a maximum hole mass of ∼40 M sun . A novel automated fitting algorithm is developed for determining optimal combinations of explosion energy, mixing, and IMF in the large model database to agree with specified data sets. The model is applied to the low-metallicity sample of Cayrel et al. and the two ultra-iron-poor stars HE0107-5240 and HE1327-2326. Best agreement with these very low metallicity stars is achieved with very little mixing, and none of the metal-deficient data sets considered show the need for a high-energy explosion component. In

  12. NEW X-RAY DETECTIONS OF WNL STARS

    International Nuclear Information System (INIS)

    Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel; Schmutz, Werner; Sokal, Kimberly R.

    2012-01-01

    Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (L x ) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v ∞ ). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing L x with wind luminosity L wind = (1/2)M-dot v 2 ∞ , suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

  13. NEW X-RAY DETECTIONS OF WNL STARS

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Stephen L. [Center for Astrophysics and Space Astronomy (CASA), University of Colorado, Boulder, CO 80309-0389 (United States); Zhekov, Svetozar A. [Space and Solar-Terrestrial Research Institute, Moskovska str. 6, Sofia-1000 (Bulgaria); Guedel, Manuel [Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Schmutz, Werner [Physikalisch-Meteorologisches Observatorium Davos (PMOD), Dorfstrasse 33, CH-7260 Davos Dorf (Switzerland); Sokal, Kimberly R., E-mail: Stephen.Skinner@colorado.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2012-05-15

    Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2-WN6 spectral subtypes. Later WN7-WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (L{sub x} ) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v{sub {infinity}}). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing L{sub x} with wind luminosity L{sub wind} = (1/2)M-dot v{sup 2}{sub {infinity}}, suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

  14. Nucleation of Quark Matter in Neutron Stars:. Role of Color Superconductivity

    Science.gov (United States)

    Bombaci, Ignazio; Lugones, Germán; Vidaña, Isaac

    2008-02-01

    Pure hadronic compact stars ("neutron stars") above a critical mass Mcr are metastable1,2 for the conversion to quark stars (hybrid or strange stars). This conversion process liberates an enormous amount of energy (Econv ~ 1053 ergs), which could power some of the observed gamma ray bursts.1-3 In cold deleptonized hadronic stars, the conversion process is triggered by the quantum nucleation of a quark matter drop in the stellar center. These drops can be made up of normal (i.e. unpaired) quark matter, or color superconducting quark matter, depending on the details of the equation of state of quark and hadronic matter.4 In this talk, we present the results of recent calculations5 of the effects of color superconductivity on the conversion of hadronic stars to quark stars. In particular, we study the dependence of the critical mass Mcr and conversion energy Econv on the quark-quark pairing gap Δ, the bag constant B, and the surface tension σ of the quark-hadron interface.

  15. Energy Value Housing Award Guide: How to Build and Profit with Energy Efficiency in New Home Construction

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, J. L.

    2001-06-01

    As concern over the environment grows, builders have the potential to fulfill a market niche by building homes that use fewer resources and have lower environmental impact than conventional construction. Builders can increase their marketability and customer satisfaction and, at the same time, reduce the environmental impact of their homes. However, it takes dedication to build environmentally sound homes along with a solid marketing approach to ensure that customers recognize the added value of energy and resource efficiency. This guide is intended for builders seeking suggestions on how to improve energy and resource efficiency in their new homes. It is a compilation of ideas and concepts for designing, building, and marketing energy- and resource-efficient homes based on the experience of recipients of the national Energy Value Housing Award (EVHA).

  16. StarSmasher: Smoothed Particle Hydrodynamics code for smashing stars and planets

    Science.gov (United States)

    Gaburov, Evghenii; Lombardi, James C., Jr.; Portegies Zwart, Simon; Rasio, F. A.

    2018-05-01

    Smoothed Particle Hydrodynamics (SPH) is a Lagrangian particle method that approximates a continuous fluid as discrete nodes, each carrying various parameters such as mass, position, velocity, pressure, and temperature. In an SPH simulation the resolution scales with the particle density; StarSmasher is able to handle both equal-mass and equal number-density particle models. StarSmasher solves for hydro forces by calculating the pressure for each particle as a function of the particle's properties - density, internal energy, and internal properties (e.g. temperature and mean molecular weight). The code implements variational equations of motion and libraries to calculate the gravitational forces between particles using direct summation on NVIDIA graphics cards. Using a direct summation instead of a tree-based algorithm for gravity increases the accuracy of the gravity calculations at the cost of speed. The code uses a cubic spline for the smoothing kernel and an artificial viscosity prescription coupled with a Balsara Switch to prevent unphysical interparticle penetration. The code also implements an artificial relaxation force to the equations of motion to add a drag term to the calculated accelerations during relaxation integrations. Initially called StarCrash, StarSmasher was developed originally by Rasio.

  17. Greening Federal Facilities: An Energy, Environmental, and Economic Resource Guide for Federal Facility Managers and Designers; Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.

    2001-05-16

    Greening Federal Facilities, Second Edition, is a nuts-and-bolts resource guide compiled to increase energy and resource efficiency, cut waste, and improve the performance of Federal buildings and facilities. The guide highlights practical actions that facility managers, design and construction staff, procurement officials, and facility planners can take to save energy and money, improve the comfort and productivity of employees, and benefit the environment. It supports a national effort to promote energy and environmental efficiency in the nation's 500,000 Federal buildings and facilities. Topics covered include current Federal regulations; environmental and energy decision-making; site and landscape issues; building design; energy systems; water and wastewater; materials; waste management, and recycling; indoor environmental quality; and managing buildings.

  18. A selection of hot subluminous stars in the GALEX survey - I. Correlation with the Guide Star Catalog

    Czech Academy of Sciences Publication Activity Database

    Vennes, Stephane; Kawka, Adela; Németh, Péter

    2011-01-01

    Roč. 410, č. 3 (2011), s. 2095-2112 ISSN 0035-8711 R&D Projects: GA AV ČR(CZ) IAA300030908; GA AV ČR IAA301630901; GA ČR GAP209/10/0967 Institutional research plan: CEZ:AV0Z10030501 Keywords : star s * fundamental parameters * subdwarfs Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.900, year: 2011

  19. MONTE CARLO NEUTRINO TRANSPORT THROUGH REMNANT DISKS FROM NEUTRON STAR MERGERS

    Energy Technology Data Exchange (ETDEWEB)

    Richers, Sherwood; Ott, Christian D. [TAPIR, Mailcode 350-17, Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Kasen, Daniel; Fernández, Rodrigo [Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); O’Connor, Evan [Department of Physics, Campus Code 8202, North Carolina State University, Raleigh, NC 27695 (United States)

    2015-11-01

    We present Sedonu, a new open source, steady-state, special relativistic Monte Carlo (MC) neutrino transport code, available at bitbucket.org/srichers/sedonu. The code calculates the energy- and angle-dependent neutrino distribution function on fluid backgrounds of any number of spatial dimensions, calculates the rates of change of fluid internal energy and electron fraction, and solves for the equilibrium fluid temperature and electron fraction. We apply this method to snapshots from two-dimensional simulations of accretion disks left behind by binary neutron star mergers, varying the input physics and comparing to the results obtained with a leakage scheme for the cases of a central black hole and a central hypermassive neutron star. Neutrinos are guided away from the densest regions of the disk and escape preferentially around 45° from the equatorial plane. Neutrino heating is strengthened by MC transport a few scale heights above the disk midplane near the innermost stable circular orbit, potentially leading to a stronger neutrino-driven wind. Neutrino cooling in the dense midplane of the disk is stronger when using MC transport, leading to a globally higher cooling rate by a factor of a few and a larger leptonization rate by an order of magnitude. We calculate neutrino pair annihilation rates and estimate that an energy of 2.8 × 10{sup 46} erg is deposited within 45° of the symmetry axis over 300 ms when a central BH is present. Similarly, 1.9 × 10{sup 48} erg is deposited over 3 s when an HMNS sits at the center, but neither estimate is likely to be sufficient to drive a gamma-ray burst jet.

  20. MONTE CARLO NEUTRINO TRANSPORT THROUGH REMNANT DISKS FROM NEUTRON STAR MERGERS

    International Nuclear Information System (INIS)

    Richers, Sherwood; Ott, Christian D.; Kasen, Daniel; Fernández, Rodrigo; O’Connor, Evan

    2015-01-01

    We present Sedonu, a new open source, steady-state, special relativistic Monte Carlo (MC) neutrino transport code, available at bitbucket.org/srichers/sedonu. The code calculates the energy- and angle-dependent neutrino distribution function on fluid backgrounds of any number of spatial dimensions, calculates the rates of change of fluid internal energy and electron fraction, and solves for the equilibrium fluid temperature and electron fraction. We apply this method to snapshots from two-dimensional simulations of accretion disks left behind by binary neutron star mergers, varying the input physics and comparing to the results obtained with a leakage scheme for the cases of a central black hole and a central hypermassive neutron star. Neutrinos are guided away from the densest regions of the disk and escape preferentially around 45° from the equatorial plane. Neutrino heating is strengthened by MC transport a few scale heights above the disk midplane near the innermost stable circular orbit, potentially leading to a stronger neutrino-driven wind. Neutrino cooling in the dense midplane of the disk is stronger when using MC transport, leading to a globally higher cooling rate by a factor of a few and a larger leptonization rate by an order of magnitude. We calculate neutrino pair annihilation rates and estimate that an energy of 2.8 × 10 46 erg is deposited within 45° of the symmetry axis over 300 ms when a central BH is present. Similarly, 1.9 × 10 48 erg is deposited over 3 s when an HMNS sits at the center, but neither estimate is likely to be sufficient to drive a gamma-ray burst jet

  1. Imaging ultrasonic dispersive guided wave energy in long bones using linear radon transform.

    Science.gov (United States)

    Tran, Tho N H T; Nguyen, Kim-Cuong T; Sacchi, Mauricio D; Le, Lawrence H

    2014-11-01

    Multichannel analysis of dispersive ultrasonic energy requires a reliable mapping of the data from the time-distance (t-x) domain to the frequency-wavenumber (f-k) or frequency-phase velocity (f-c) domain. The mapping is usually performed with the classic 2-D Fourier transform (FT) with a subsequent substitution and interpolation via c = 2πf/k. The extracted dispersion trajectories of the guided modes lack the resolution in the transformed plane to discriminate wave modes. The resolving power associated with the FT is closely linked to the aperture of the recorded data. Here, we present a linear Radon transform (RT) to image the dispersive energies of the recorded ultrasound wave fields. The RT is posed as an inverse problem, which allows implementation of the regularization strategy to enhance the focusing power. We choose a Cauchy regularization for the high-resolution RT. Three forms of Radon transform: adjoint, damped least-squares, and high-resolution are described, and are compared with respect to robustness using simulated and cervine bone data. The RT also depends on the data aperture, but not as severely as does the FT. With the RT, the resolution of the dispersion panel could be improved up to around 300% over that of the FT. Among the Radon solutions, the high-resolution RT delineated the guided wave energy with much better imaging resolution (at least 110%) than the other two forms. The Radon operator can also accommodate unevenly spaced records. The results of the study suggest that the high-resolution RT is a valuable imaging tool to extract dispersive guided wave energies under limited aperture. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Shock-induced star formation in a model of the Mice

    OpenAIRE

    Barnes, Joshua E.

    2004-01-01

    Star formation plays an important role in the fate of interacting galaxies. To date, most galactic simulations including star formation have used a density-dependent star formation rule designed to approximate a Schmidt law. Here, I present a new star formation rule which is governed by the local rate of energy dissipation in shocks. The new and old rules are compared using self-consistent simulations of NGC 4676; shock-induced star formation provides a better match to the observations of thi...

  3. Generalised model for anisotropic compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, S.K. [University of Nizwa, Department of Mathematical and Physical Sciences College of Arts and Science, Nizwa (Oman); Gupta, Y.K. [Raj Kumar Goel Institute of Technology, Department of Mathematics, Ghaziabad, Uttar Pradesh (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Deb, Debabrata [Indian Institute of Engineering Science and Technology, Shibpur, Department of Physics, Howrah, West Bengal (India)

    2016-12-15

    In the present investigation an exact generalised model for anisotropic compact stars of embedding class 1 is sought with a general relativistic background. The generic solutions are verified by exploring different physical aspects, viz. energy conditions, mass-radius relation, stability of the models, in connection to their validity. It is observed that the model presented here for compact stars is compatible with all these physical tests and thus physically acceptable as far as the compact star candidates RXJ 1856-37, SAX J 1808.4-3658 (SS1) and SAX J 1808.4-3658 (SS2) are concerned. (orig.)

  4. Fixed Target Collisions at STAR

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Kathryn C.

    2016-12-15

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. Previous results have been used to claim that the onset of deconfinement occurs at a center-of-mass energy of 7 GeV. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies of 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb potential analysis of Au + Au fixed-target collisions are presented and are found to be consistent with results from previous experiments. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared to published results from the AGS.

  5. A Policymaker's Guide to Scaling Home Energy Upgrades

    Energy Technology Data Exchange (ETDEWEB)

    LeBaron, Robin [Home Performance Coalition, Moon, PA (United States); Saul-Rinaldi, Kara [Home Performance Coalition, Moon, PA (United States)

    2015-09-01

    There has never been a better time to launch initiatives to promote residential energy efficiency savings. Over the past several decades, residential retrofit programs have demonstrated that energy efficiency measures contribute to achieving multiple benefits, including but not limited to reductions in home energy consumption, stabilization improvements for the grid by shaving peak loads, saving consumers millions on utility bills, and significantly reducing carbon emissions. Although a number of barriers to widespread uptake of home energy upgrades persist, the lessons learned as a result of the 2009 stimulus funding1 have resulted in a set of policy approaches that create new strategies for taking residential energy efficiency to scale.2 The identification of these approaches is well timed; energy efficiency is often the least expensive and most cost effective way to comply with a variety of federal, state and local policies. This Guide is designed to help state and local policymakers to take full advantage of new policy developments by providing them with a comprehensive set of tools to support launching or accelerating residential energy efficiency programs. It is written primarily for state and local policymakers, including state and local executives, legislators, public utility commissioners, and the staff who advise them.

  6. The effective temperatures of early Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Schmutz, W.

    1982-01-01

    Nussbaumer et al. (1981) (NSSW) have calculated temperatures of 15 Wolf-Rayet stars, which cover most subtypes in the WN and WC sequences. Some Wolf-Rayet stars are found to have a blackbody-like energy distribution and therefore their effective temperature can be well determined, others show deviation from the blackbody shape. This deviation is probably due to an extended continuum emitting region. In view of these later cases NSSW adopted a temperature which they derived from a Zanstra analysis of the He II recombination lines. According to their analysis there should be a continuum jump at 2050 A. New IUE observations of the WN 5 star HD 50896 however did not show any trace of such an absorption edge. This implies that the effective temperature of this WN 5 star and probably of all WR stars with a non blackbody energy distribution is not yet known accurately. Therefore the author started a detailed analysis with a spherically symmetric atmosphere model. Though the model has not yet reached its final shape he has obtained as a first result that the location of HD 50896 in the HR-diagram is to the left of the ZAMS and that the Zanstra analysis is indeed not valid for this star. (Auth.)

  7. Stellar Wind Retention and Expulsion in Massive Star Clusters

    Science.gov (United States)

    Naiman, J. P.; Ramirez-Ruiz, E.; Lin, D. N. C.

    2018-05-01

    Mass and energy injection throughout the lifetime of a star cluster contributes to the gas reservoir available for subsequent episodes of star formation and the feedback energy budget responsible for ejecting material from the cluster. In addition, mass processed in stellar interiors and ejected as winds has the potential to augment the abundance ratios of currently forming stars, or stars which form at a later time from a retained gas reservoir. Here we present hydrodynamical simulations that explore a wide range of cluster masses, compactnesses, metallicities and stellar population age combinations in order to determine the range of parameter space conducive to stellar wind retention or wind powered gas expulsion in star clusters. We discuss the effects of the stellar wind prescription on retention and expulsion effectiveness, using MESA stellar evolutionary models as a test bed for exploring how the amounts of wind retention/expulsion depend upon the amount of mixing between the winds from stars of different masses and ages. We conclude by summarizing some implications for gas retention and expulsion in a variety of compact (σv ≳ 20 kms-1) star clusters including young massive star clusters (105 ≲ M/M⊙ ≲ 107, age ≲ 500 Myrs), intermediate age clusters (105 ≲ M/M⊙ ≲ 107, age ≈ 1 - 4 Gyrs), and globular clusters (105 ≲ M/M⊙ ≲ 107, age ≳ 10 Gyrs).

  8. Slowly braked, rotating neutron stars

    Science.gov (United States)

    Sato, H.

    1975-01-01

    A slowly braked, rotating neutron star is believed to be a star which rapidly rotates, has no nebula, is nonpulsing, and has a long initial braking time of ten thousand to a million years because of a low magnetic field. Such an object might be observable as an extended weak source of infrared or radio wave radiation due to the scattering of low-frequency strong-wave photons by accelerated electrons. If these objects exist abundantly in the Galaxy, they would act as sources of relatively low-energy cosmic rays. Pulsars (rapidly braked neutron stars) are shown to have difficulties in providing an adequate amount of cosmic-ray matter, making these new sources seem necessary. The possibility that the acceleration mechanism around a slowly braked star may be not a direct acceleration by the strong wave but an acceleration due to plasma turbulence excited by the strong wave is briefly explored. It is shown that white dwarfs may also be slowly braked stars with braking times longer than 3.15 million years.

  9. Modeling Atmospheric Activity of Cool Stars

    Science.gov (United States)

    Schrijver, C. J.

    2003-10-01

    This review discusses a set of simple models for cool-star activity with which we compute (1) photospheric field patterns on stars of different activity levels, (2) the associated outer-atmospheric field configurations, and (3) the soft X-ray emission that is expected to result from the ensemble of loop atmospheres in the coronae of these stars. The model is based on empirically-determined properties of solar activity. It allows us to extrapolate to stars of significantly higher and lower activity than seen on the present-day Sun through its cycle. With it, we can, for example, gain insight into stellar field patterns (including a possible formation mechanism for polar starspots), as well as in the properties of coronal heating (helpful in the identification of the quiescent coronal heating mechanism). Lacking comprehensive theoretical understanding, the model's reliance on empirical solar data means that the multitude of processes involved are approximated to be independent of rotation rate, activity level, and fundamental stellar parameters, or -- where unavoidably necessary -- assumed to simply scale with activity. An evaluation of the most important processes involved guides a discussion of the limits of the model, of the limitations in our knowledge, and of future needs. "I propose to adopt such rules as will ensure the testability of scientific statements; which is to say, their falsifiability." Karl Popper (1902-1994)

  10. Explosion of a low mass neutron star

    International Nuclear Information System (INIS)

    Blinnikov, S.I.; Imshennik, V.S.; Nadyozhin, D.K.; Novikov, I.D.; Polnarev, A.G.; AN SSSR, Moscow. Fizicheskij Inst.); Perevodchikova, T.V.

    1990-01-01

    The hydrodynamical disruption of a low mass neutron star is investigated for the case when the stellar mass becomes smaller than the minimum value, M min ≅0.1 M sun . The final phase of the process is shown to proceed explosively, leading to an expansion of all the star, with a kinetic energy of 4.8 MeV per nucleon. The results of calculations are virtually independent of the way in which the neutron star mass goes down below M min (mass exchange in a close binary stellar system, nucleon decay, or some effective mass loss due to a hypothetical decrease of the gravitational constant). The neutron star disruption is followed by a short (0.01-0.1 s) burst of thermal hard X-rays and soft gamma-rays (kT=10-100 keV) with a subsequent much more prolonged tail of radiation induced by decays of long-lived radioactive nuclides. Some fraction of the explosion energy may be emitted in the form of neutrinos. (orig.)

  11. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    Directory of Open Access Journals (Sweden)

    Zheng You

    2013-04-01

    Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

  12. Optical system error analysis and calibration method of high-accuracy star trackers.

    Science.gov (United States)

    Sun, Ting; Xing, Fei; You, Zheng

    2013-04-08

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

  13. The STAR Vertex Position Detector

    Energy Technology Data Exchange (ETDEWEB)

    Llope, W.J., E-mail: llope@rice.edu [Rice University, Houston, TX 77005 (United States); Zhou, J.; Nussbaum, T. [Rice University, Houston, TX 77005 (United States); Hoffmann, G.W. [University of Texas, Austin, TX 78712 (United States); Asselta, K. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Brandenburg, J.D.; Butterworth, J. [Rice University, Houston, TX 77005 (United States); Camarda, T.; Christie, W. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Crawford, H.J. [University of California, Berkeley, CA 94720 (United States); Dong, X. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Engelage, J. [University of California, Berkeley, CA 94720 (United States); Eppley, G.; Geurts, F. [Rice University, Houston, TX 77005 (United States); Hammond, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Judd, E. [University of California, Berkeley, CA 94720 (United States); McDonald, D.L. [Rice University, Houston, TX 77005 (United States); Perkins, C. [University of California, Berkeley, CA 94720 (United States); Ruan, L.; Scheblein, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

    2014-09-21

    The 2×3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2×19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event “start time” needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ∼100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ∼1 cm.

  14. Assessing magnetic torques and energy fluxes in close-in star-planet systems

    OpenAIRE

    Strugarek, A

    2016-01-01

    Planets in close-in orbit interact with the magnetized wind of their hosting star. This magnetic interaction was proposed to be a source for enhanced emissions in the chromosphere of the star, and to participate in setting the migration time-scale of the close-in planet. The efficiency of the magnetic interaction is know to depend on the magnetic properties of the host star, of the planet, and on the magnetic topology of the interaction. We use a global, three-dimensional numerical model of c...

  15. Birth, evolution and death of stars

    CERN Document Server

    Lequeux, James

    2013-01-01

    It has been known for a long time that stars are similar to our Sun. But it was only in 1810 that they were shown to be made of an incandescent gas. The chemical composition of this gas began to be determined in 1860. In 1940, it was demonstrated that the energy radiated by the stars is of thermonuclear origin. How stars form from interstellar matter and how they evolve and die was understood only recently, with our knowledge still incomplete. It was also realized recently that close double stars present a wide variety of extraordinary phenomena, which are far from being completely explored. This book explains all these aspects, and also discusses how the evolution of stars determine that of galaxies. The most interesting observations are illustrated by spectacular images, while the theory is explained as simply as possible, without however avoiding some mathematical or physical developments when they are necessary for a good understanding of what happens in stars. Without being a textbook for specialists, t...

  16. Classifier-Guided Sampling for Complex Energy System Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Backlund, Peter B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Eddy, John P. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    This report documents the results of a Laboratory Directed Research and Development (LDRD) effort enti tled "Classifier - Guided Sampling for Complex Energy System Optimization" that was conducted during FY 2014 and FY 2015. The goal of this proj ect was to develop, implement, and test major improvements to the classifier - guided sampling (CGS) algorithm. CGS is type of evolutionary algorithm for perform ing search and optimization over a set of discrete design variables in the face of one or more objective functions. E xisting evolutionary algorithms, such as genetic algorithms , may require a large number of o bjecti ve function evaluations to identify optimal or near - optimal solutions . Reducing the number of evaluations can result in significant time savings, especially if the objective function is computationally expensive. CGS reduce s the evaluation count by us ing a Bayesian network classifier to filter out non - promising candidate designs , prior to evaluation, based on their posterior probabilit ies . In this project, b oth the single - objective and multi - objective version s of the CGS are developed and tested on a set of benchm ark problems. As a domain - specific case study, CGS is used to design a microgrid for use in islanded mode during an extended bulk power grid outage.

  17. A novel double fine guide sensor design on space telescope

    Science.gov (United States)

    Zhang, Xu-xu; Yin, Da-yi

    2018-02-01

    To get high precision attitude for space telescope, a double marginal FOV (field of view) FGS (Fine Guide Sensor) is proposed. It is composed of two large area APS CMOS sensors and both share the same lens in main light of sight. More star vectors can be get by two FGS and be used for high precision attitude determination. To improve star identification speed, the vector cross product in inter-star angles for small marginal FOV different from traditional way is elaborated and parallel processing method is applied to pyramid algorithm. The star vectors from two sensors are then used to attitude fusion with traditional QUEST algorithm. The simulation results show that the system can get high accuracy three axis attitudes and the scheme is feasibility.

  18. 77 FR 43586 - Southern Star Central Gas Pipeline, Inc.; Notice of Intent To Prepare an Environmental Assessment...

    Science.gov (United States)

    2012-07-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-479-000] Southern Star... abandonment of facilities by Southern Star Central Gas Pipeline, Inc. (Southern Star) in Logan and Oklahoma... concern. Southern Star provided landowners with a fact sheet prepared by the FERC entitled ``An Interstate...

  19. The Monthly Sky Guide: Sixth Edition

    Science.gov (United States)

    Ridpath, Ian; Tirion, Wil

    2003-06-01

    The latest edition of Ian Ridpath and Wil Tirion's popular guide to the night sky is updated for planet positions and forthcoming eclipses up to the end of the year 2007. With one chapter for each month of the year, this is an easy-to-use handbook for anyone wanting to identify constellations, star clusters, nebulae, to plot the movement of planets, or witness solar and lunar eclipses. Most of the features discussed are visible to the naked eye and all can be seen with a small telescope or binoculars. Ian Ridpath has been a full-time writer, broadcaster and lecturer on astronomy and space for more than twenty-five years. He has written and edited more than 40 books, including A Comet Called Haley (Cambridge, 1985). Wil Tirion made his first star map in 1977. It showed stars to the magnitude of 6.5 and was issued as a set of maps by the British Astronomical Association in 1981. He has illustrated numerous books and magazines, including The Cambridge Star Atlas (Cambridge, 2001). Previous Edition Pb (1999): 0-521-66771-2

  20. The fluorine destruction in stars: First experimental study of the {sup 19}F(p,{alpha}){sup 16}O reaction at astrophysical energies

    Energy Technology Data Exchange (ETDEWEB)

    La Cognata, M.; Mukhamedzhanov, A.; Spitaleri, C.; Indelicato, I.; Aliotta, M.; Burjan, V.; Cherubini, S.; Coc, A.; Gulino, M.; Hons, Z.; Kiss, G. G.; Kroha, V.; Lamia, L.; Mrazek, J.; Palmerini, S.; Piskor, S.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S. [INFN-LNS, Catania (Italy); Cyclotron Institute, Texas A and M University, College Station, Texas (United States); University of Catania and INFN-LNS, Catania (Italy); and others

    2012-11-12

    The {sup 19}F(p,{alpha}){sup 16}O reaction is an important fluorine destruction channel in the proton-rich outer layers of asymptotic giant branch (AGB) stars and it might also play a role in hydrogendeficient post-AGB star nucleosynthesis. So far, available direct measurements do not reach the energy region of astrophysical interest (E{sub cm}{approx} 300 keV), because of the hindrance effect of the Coulomb barrier. The Trojan Horse (TH) method was thus used to access this energy region, by extracting the quasi-free contribution to the {sup 2}H({sup 19}F,{alpha}{sup 16}O)n reaction. The TH measurement of the {alpha}{sub 0} channel, which is the dominant one at such energies, shows the presence of resonant structures not observed before that cause an increase of the reaction rate at astrophysical temperatures up to a factor of 1.7, with potential important consequences for stellar nucleosynthesis.

  1. Spectral energy distribution analysis of class I and class II FU Orionis stars

    Energy Technology Data Exchange (ETDEWEB)

    Gramajo, Luciana V.; Gómez, Mercedes [Observatorio Astronómico, Universidad Nacional de Córdoba, Argentina, Laprida 854, 5000 Córdoba (Argentina); Rodón, Javier A., E-mail: luciana@oac.uncor.edu, E-mail: mercedes@oac.uncor.edu, E-mail: jrodon@eso.org [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile)

    2014-06-01

    FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ∼80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ∼10{sup –7} M {sub ☉} yr{sup –1} versus ∼10{sup –5} M {sub ☉} yr{sup –1} for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (∼70%) have envelope mass accretion rates above 10{sup –7} M {sub ☉} yr{sup –1}. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.

  2. On the Stability of Strange Dwarf Hybrid Stars

    Energy Technology Data Exchange (ETDEWEB)

    Alford, Mark G.; Harris, Steven P. [Physics Department, Washington University, St. Louis, MO 63130 (United States); Sachdeva, Pratik S., E-mail: harrissp@wustl.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2017-10-01

    We investigate the stability of “strange dwarfs”: white-dwarf-sized stars with a density discontinuity between a small dense core of quark matter and a thick low-density mantle of degenerate electrons. Previous work on strange dwarfs suggested that such a discontinuity could stabilize stars that would have been classified as unstable by the conventional criteria based on extrema in the mass–radius relation. We investigate the stability of such stars by numerically solving the Sturm–Liouville equations for the lowest-energy modes of the star. We find that the conventional criteria are correct, and strange dwarfs are not stable.

  3. Astronomy a visual guide

    CERN Document Server

    Garlick, Mark A

    2004-01-01

    Space has fascinated man and challenged scientists for centuries and astronomy is the oldest and one of the most dynamic of the sciences. Here is a book that will stimulate your curiosity and feed your imagination. Detailed and fascinating text is clearly and richly illustrated with fabulous, vibrant photographs and diagrams. This is a comprehensive guide to understanding and observing the night sky, from distant stars and galaxies to our neighbouring planets; from comets to shooting stars; from eclipses to black holes. With details of the latest space probes, a series of monthly sky maps to provide guidance for the amateur observer and the latest photos from space, this book brings the beauty and wonder of our universe into your living room and will have you reaching for the telescope!

  4. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    Energy Technology Data Exchange (ETDEWEB)

    Theodorakis, P E [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Avgeropoulos, A [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Freire, J J [Departamento de Ciencias y Tecnicas FisicoquImicas, Universidad Nacional de Educacion a Distancia, Facultad de Ciencias, Senda del Rey 9, 28040 Madrid (Spain); Kosmas, M [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece); Vlahos, C [Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

    2007-11-21

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

  5. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    Science.gov (United States)

    Theodorakis, P. E.; Avgeropoulos, A.; Freire, J. J.; Kosmas, M.; Vlahos, C.

    2007-11-01

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results.

  6. Monte Carlo simulation of star/linear and star/star blends with chemically identical monomers

    International Nuclear Information System (INIS)

    Theodorakis, P E; Avgeropoulos, A; Freire, J J; Kosmas, M; Vlahos, C

    2007-01-01

    The effects of chain size and architectural asymmetry on the miscibility of blends with chemically identical monomers, differing only in their molecular weight and architecture, are studied via Monte Carlo simulation by using the bond fluctuation model. Namely, we consider blends composed of linear/linear, star/linear and star/star chains. We found that linear/linear blends are more miscible than the corresponding star/star mixtures. In star/linear blends, the increase in the volume fraction of the star chains increases the miscibility. For both star/linear and star/star blends, the miscibility decreases with the increase in star functionality. When we increase the molecular weight of linear chains of star/linear mixtures the miscibility decreases. Our findings are compared with recent analytical and experimental results

  7. Low-mass neutron stars: universal relations, the nuclear symmetry energy and gravitational radiation

    Science.gov (United States)

    O. Silva, Hector; Berti, Emanuele; Sotani, Hajime

    2016-03-01

    Compact objects such as neutron stars are ideal astrophysical laboratories to test our understanding of the fundamental interactions in the regime of supranuclear densities, unachievable by terrestrial experiments. Despite recent progress, the description of matter (i.e., the equation of state) at such densities is still debatable. This translates into uncertainties in the bulk properties of neutron stars, masses and radii for instance. Here we will consider low-mass neutron stars. Such stars are expected to carry important information on nuclear matter near the nuclear saturation point. It has recently been shown that the masses and surface redshifts of low-mass neutron stars smoothly depend on simple functions of the central density and of a characteristic parameter η associated with the choice of equation of state. Here we extend these results to slowly-rotating and tidally deformed stars and obtain empirical relations for various quantities, such as the moment of inertia, quadrupole moment and ellipticity, tidal and rotational Love numbers, and rotational apsidal constants. We discuss how these relations might be used to constrain the equation of state by future observations in the electromagnetic and gravitational-wave spectra.

  8. Five-Star Schools: Defining Quality in Early Childhood Programs

    Science.gov (United States)

    Hertzog, Nancy B.

    2012-01-01

    Hakeem, Emily, Jose, and Latisha are all entering preschool in the fall. Their mothers are looking for the highest quality early childhood program they can find. Is there a guide for them to find a five-star program? Are all certified or accredited programs of equal quality? How do these parents and guardians know what defines quality in early…

  9. Wolf-Rayet stars as gamma-ray burst progenitors

    NARCIS (Netherlands)

    Langer, N.; van Marle, A. -J; Yoon, S.C.

    2010-01-01

    It became clear in the last few years that long gamma-ray bursts are associated with the endpoints of massive star evolution. They occur in star forming regions at cosmological distances (Jakobsson et al., 2005), and are associated with supernova-type energies. The collapsar model explains gamma-ray

  10. Transformation toward a Secure and Precaution-Oriented Energy System with the Guiding Concept of Resilience—Implementation of Low-Exergy Solutions in Northwestern Germany

    Directory of Open Access Journals (Sweden)

    Urte Brand

    2015-07-01

    Full Text Available Climate changes, incidents like nuclear disasters, and associated political objectives call for significant changes to the current energy system. Despite these far-reaching transformation processes, within the intended changes security of supply and precautions against the possible consequences of climate change must be ensured. Consequently, the question arises how to direct energy systems. In this context the processes of guiding orientations with the help of the guiding concept of “resilient systems” and feasible and addressee-oriented guiding design principles can be an option to provide guidance in transformation processes. However, it is questionable whether and how such processes are effective in the long term and if they are able to give direction by doing so. Within the framework of empirical studies of a regional guiding orientation process for the energy system of Northwestern Germany, the long-term effectiveness of the process and its spread resilient guiding design principles of “low-exergy solutions” and “climate-adapted and energy-efficient refrigeration” has been confirmed. Such effectiveness requires the implementation of a four-phase guiding orientation process which takes content-related and process-related effectiveness factors into account. Therefore, the study shows how regional energy systems can be designed toward the major challenges of ensuring security and precaution.

  11. Gravitational waves from rotating strained neutron stars

    International Nuclear Information System (INIS)

    Jones, D I

    2002-01-01

    In this review we examine the dynamics and gravitational wave detectability of rotating strained neutron stars. The discussion is divided into two halves: triaxial stars and precessing stars. We summarize recent studies on how crustal strains and magnetic fields can sustain triaxiality, and suggest that Magnus forces connected with pinned superfluid vortices might contribute to deformation also. The conclusions that could be drawn following the successful gravitational wave detection of a triaxial star are discussed, and areas requiring further study identified. The latest ideas regarding free precession are then outlined, and the recent suggestion of Middleditch et al (Middleditch et al 2000 New Astronomy 5 243; 2000 Preprint astro-ph/0010044) that the remnant of SN1987A contains a freely precessing star, spinning down by gravitational wave energy loss, is examined critically. We describe what we would learn about neutron stars should the gravitational wave detectors prove this hypothesis to be correct

  12. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    Energy Technology Data Exchange (ETDEWEB)

    Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Leonidaki, I.; Xilouris, E. M. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece); Weiß, A.; Henkel, C. [Max-Planck-Institut fur Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Z.-Y. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Van der Werf, P.; Meijerink, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, 43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Evans, A. S. [Astronomy Department, University of Virginia Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Universidad de Alcala de Henares, Departamento de Fśica, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Harris, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Naylor, D. A. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada); Smith, H. A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spaans, M., E-mail: t.greve@ucl.ac.uk [Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen (Netherlands); and others

    2014-10-20

    We present FIR [50-300 μm]–CO luminosity relations (i.e., log L{sub FIR}=αlog L{sub CO}{sup ′}+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub μm]} > 10{sup 11} L {sub ☉}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>10{sup 4} cm{sup –3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for

  13. Night sky a falcon field guide

    CERN Document Server

    Nigro, Nicholas

    2012-01-01

    Night Sky: A Falcon Field Guide covers both summer and winter constellations, planets, and stars found in the northern hemisphere. Conveniently sized to fit in a pocket and featuring detailed photographs, this informative guide makes it easy to identify objects in the night sky even from one's own backyard. From information on optimal weather conditions, preferred viewing locations, and how to use key tools of the trade, this handbook will help you adeptly navigate to and fro the vast and dynamic nighttime skies, and you'll fast recognize that the night sky's the limit.

  14. Stellar equilibrium configurations of compact stars in f(R,T) theory of gravity

    Science.gov (United States)

    Moraes, P. H. R. S.; Arbañil, José D. V.; Malheiro, M.

    2016-06-01

    In this article we study the hydrostatic equilibrium configuration of neutron stars and strange stars, whose fluid pressure is computed from the equations of state p=ωρ5/3 and p=0.28(ρ-4Script B), respectively, with ω and Script B being constants and ρ the energy density of the fluid. We start by deriving the hydrostatic equilibrium equation for the f(R,T) theory of gravity, with R and T standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Such an equation is a generalization of the one obtained from general relativity, and the latter can be retrieved for a certain limit of the theory. For the f(R,T)=R+2λ T functional form, with λ being a constant, we find that some physical properties of the stars, such as pressure, energy density, mass and radius, are affected when λ is changed. We show that for a fixed central star energy density, the mass of neutron and strange stars can increase with λ. Concerning the star radius, it increases for neutron stars and it decreases for strange stars with the increment of λ. Thus, in f(R,T) theory of gravity we can push the maximum mass above the observational limits. This implies that the equation of state cannot be eliminated if the maximum mass within General Relativity lies below the limit given by observed pulsars.

  15. Stellar equilibrium configurations of compact stars in f ( R , T ) theory of gravity

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, P.H.R.S.; Arbañil, José D.V.; Malheiro, M., E-mail: moraes.phrs@gmail.com, E-mail: arbanil@ita.br, E-mail: malheiro@ita.br [ITA—Instituto Tecnológico de Aeronáutica—Departamento de Física, 12228-900, São José dos Campos, São Paulo (Brazil)

    2016-06-01

    In this article we study the hydrostatic equilibrium configuration of neutron stars and strange stars, whose fluid pressure is computed from the equations of state p =ωρ{sup 5/3} and p =0.28(ρ−4B), respectively, with ω and B being constants and ρ the energy density of the fluid. We start by deriving the hydrostatic equilibrium equation for the f ( R , T ) theory of gravity, with R and T standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Such an equation is a generalization of the one obtained from general relativity, and the latter can be retrieved for a certain limit of the theory. For the f ( R , T )= R +2λ T functional form, with λ being a constant, we find that some physical properties of the stars, such as pressure, energy density, mass and radius, are affected when λ is changed. We show that for a fixed central star energy density, the mass of neutron and strange stars can increase with λ. Concerning the star radius, it increases for neutron stars and it decreases for strange stars with the increment of λ. Thus, in f ( R , T ) theory of gravity we can push the maximum mass above the observational limits. This implies that the equation of state cannot be eliminated if the maximum mass within General Relativity lies below the limit given by observed pulsars.

  16. Gravitational radiation emitted when a mass falls onto a compact star.

    Science.gov (United States)

    Borelli, A.

    1997-03-01

    The authors study the energy spectrum related to the axial perturbations of a compact star when a particle falls spiralling onto it. They find that both slowly-damped quasi-normal modes and strongly damped w-modes are excited, and that a part of the energy in the process is associated to these w-modes. A substantial difference between the energy spectra of compact stars and black holes is shown.

  17. Radial stability of anisotropic strange quark stars

    Energy Technology Data Exchange (ETDEWEB)

    Arbañil, José D.V.; Malheiro, M., E-mail: jose.arbanil@upn.pe, E-mail: malheiro@ita.br [ITA—Instituto Tecnológico de Aeronáutica—Departamento de Física, 12228-900, São José dos Campos, São Paulo (Brazil)

    2016-11-01

    The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original version to include this effect. The strange matter inside the quark stars is described by the MIT bag model equation of state. For the anisotropy two different kinds of local anisotropic σ = p {sub t} − p {sub r} are considered, where p {sub t} and p {sub r} are respectively the tangential and the radial pressure: one that is null at the star's surface defined by p {sub r} ( R ) = 0, and one that is nonnull at the surface, namely, σ {sub s} = 0 and σ {sub s} {sub ≠} {sub 0}. In the case σ {sub s} = 0, the maximum mass value and the zero frequency of oscillation are found at the same central energy density, indicating that the maximum mass marks the onset of the instability. For the case σ {sub s} {sub ≠} {sub 0}, we show that the maximum mass point and the zero frequency of oscillation coincide in the same central energy density value only in a sequence of equilibrium configurations with the same value of σ {sub s} . Thus, the stability star regions are determined always by the condition dM / d ρ {sub c} {sub >} {sub 0} only when the tangential pressure is maintained fixed at the star surface's p {sub t} ( R ). These results are also quite important to analyze the stability of other anisotropic compact objects such as neutron stars, boson stars and gravastars.

  18. On hot and cool stars, spectroscopic investigations in the ultraviolet

    International Nuclear Information System (INIS)

    Hucht, K.A. van der.

    1978-01-01

    Measured ultraviolet stellar spectra are compared with theoretically synthesised spectra. Three A-type and some B-type stars have been observed. The expanding outer layers of cool giants and supergiants are dealt with. K-type and M-type stars are discussed. The problem of the continuous energy distribution of Wolf-Tayet stars derived from observations is considered. (C.F.)

  19. Consumer protection issues in energy: a guide for attorneys general. Insulation, solar, automobile device, home devices

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Harry I.; Hulse, William S.; Jones, Robert R.; Langer, Robert M.; Petrucelli, Paul J.; Schroeder, Robert J.

    1979-11-01

    The guide attempts to bring together two important and current issues: energy and consumer protection. Perhaps the most basic consumer-protection issue in the energy area is assuring adequate supplies at adequate prices. It is anticipated, though, that consumers will want to consider new ways to lower enegy consumption and cost, and will thus be susceptible to fraudulent energy claims. Information is prepared on insulation, solar, energy-saving devices for the home, and energy-saving devices for the automobile.

  20. The NuSTAR Extragalactic Survey: A First Sensitive Look at the High-Energy Cosmic X-Ray Background Population

    Science.gov (United States)

    Alexander, D. M.; Stern, D.; DelMoro, A.; Lansbury, G. B.; Assef, R. J.; Aird, J.; Ajello, M.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.; hide

    2013-01-01

    We report on the first 10 identifications of sources serendipitously detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) to provide the first sensitive census of the cosmic X-ray background source population at approximately greater than 10 keV. We find that these NuSTAR-detected sources are approximately 100 times fainter than those previously detected at approximately greater than 10 keV and have a broad range in redshift and luminosity (z = 0.020-2.923 and L(sub 10-40 keV) approximately equals 4 × 10(exp 41) - 5 × 10(exp 45) erg per second; the median redshift and luminosity are z approximately equal to 0.7 and L(sub 10-40 keV) approximately equal to 3 × 10(exp 44) erg per second, respectively. We characterize these sources on the basis of broad-band approximately equal to 0.5 - 32 keV spectroscopy, optical spectroscopy, and broad-band ultraviolet-to-mid-infrared spectral energy distribution analyses. We find that the dominant source population is quasars with L(sub 10-40 keV) greater than 10(exp 44) erg per second, of which approximately 50% are obscured with N(sub H) approximately greater than 10(exp 22) per square centimeters. However, none of the 10 NuSTAR sources are Compton thick (N(sub H) approximately greater than 10(exp 24) per square centimeters) and we place a 90% confidence upper limit on the fraction of Compton-thick quasars (L(sub 10-40 keV) greater than 10(exp 44) erg per second) selected at approximately greater than 10 keV of approximately less than 33% over the redshift range z = 0.5 - 1.1. We jointly fitted the rest-frame approximately equal to 10-40 keV data for all of the non-beamed sources with L(sub 10-40 keV) greater than 10(exp 43) erg per second to constrain the average strength of reflection; we find R less than 1.4 for gamma = 1.8, broadly consistent with that found for local active galactic nuclei (AGNs) observed at approximately greater than 10 keV. We also constrain the host-galaxy masses and find a median stellar

  1. 76 FR 41788 - Southern Star Central Gas Pipeline, Inc.; Notice of Intent To Prepare an Environmental Assessment...

    Science.gov (United States)

    2011-07-15

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. CP11-481-000] Southern Star... Southern Star Central Gas Pipeline, Inc. (Southern Star) in Rice County, Kansas. This EA will be used by... Facility On My Land? What Do I Need To Know?'' was attached to the project notice Southern Star provided to...

  2. Similarity solutions for explosions in radiating stars with time-dependent energy and idealized magnetic field

    International Nuclear Information System (INIS)

    Verma, G.B.; Vishwakarma, J.P.; Sharan, V.

    1983-01-01

    A stellar model in which density in the undisturbed conducting-gas medium is assumed to obey a power law is considered. Similarity solutions for central explosion in radiating stars have been obtained under the assumption of isothermal-shock conditions. For the existence of self-similar character, it has been assumed that both radiation pressure and energy are negligible. The results of numerical calculations for different models are illustrated through graphs. Moreover, a comparative study has been made between the results in ordinary gasdynamics and those obtained in magnetogasdynamics

  3. SEE Action Guide for States: Evaluation, Measurement, and Verification Frameworks$-$Guidance for Energy Efficiency Portfolios Funded by Utility Customers

    Energy Technology Data Exchange (ETDEWEB)

    Li, Michael [Dept. of Energy (DOE), Washington DC (United States); Dietsch, Niko [US Environmental Protection Agency (EPA), Cincinnati, OH (United States)

    2018-01-01

    This guide describes frameworks for evaluation, measurement, and verification (EM&V) of utility customer–funded energy efficiency programs. The authors reviewed multiple frameworks across the United States and gathered input from experts to prepare this guide. This guide provides the reader with both the contents of an EM&V framework, along with the processes used to develop and update these frameworks.

  4. U. S. EPA voluntary programs and the oil and gas industry : Natural Gas STAR and Energy STAR Buildings Partnership

    International Nuclear Information System (INIS)

    Gunnung, P.

    2000-01-01

    The structure of two EPA programs directed towards wasted energy in buildings, reducing emissions, increasing energy efficiency and maximizing profits are described. The programs are based on a partnership approach between EPA and participants, and involve elements of plans and performance benchmarks, an integrated approach and communications and demonstration of successful initiatives. EPA provides planning and technical support in the form of a website, software tools, manuals, electronic sources and a purchasing tool kit. The Energy STAR Building Partnership has over 3,000 participants, and can boast of a cumulative saving of over $ 1.4 billion in energy bills and carbon dioxide emission reduction of 44.1 billion pounds, resulting from efficiency upgrades. The Natural Gas Partnership between the EPA and the oil and natural gas industry to cost effectively reduce methane emissions from the production, transmission, and distribution of natural gas also has had a number of successful initiatives such as replacement or retrofit of high bleed pneumatic devices, installation of flash tank separators on glycol dehydrators and other partner-reported projects such as replacement of wet seals with dry seals on compressors and connecting glycol pump to vapour recovery unit. As a results of these and other initiatives, annual methane emission was reduced by 22.2 bcf in 1998 as opposed to 3.4 bcf prior to the beginning of the program in 1993. Approximately 67 per cent of all reductions can be attributed to partner innovation. Overall assessment is that the program is innovative, achieves both economic and environmental goals, facilitates government and industry cooperation and is living proof that non-regulatory, cooperative programs work

  5. Neutron stars

    International Nuclear Information System (INIS)

    Irvine, J.M.

    1978-01-01

    The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

  6. Effective interaction: From nuclear reactions to neutron stars

    Indian Academy of Sciences (India)

    pact stars. The nuclear EoS for β-equilibrated neutron star (NS) matter obtained using density-dependent effective nucleon–nucleon interaction satisfies the constraints from the observed flow data from heavy-ion collisions. The energy density of quark matter is lower than that of the nuclear EoS at higher densities implying ...

  7. A Practical Guide to Lightcurve Photometry and Analysis

    CERN Document Server

    Warner, Brian D

    2006-01-01

    A Practical Guide to Lightcurve Photometry and Analysis provides, for those with access to even a modest telescope and CCD camera, all the information needed to take part in the scientific study of asteroids and variable stars. Using commercially available equipment, amateur astronomers can determine the rotation rate, size, and shape of asteroids. Similarly, it is possible to discover the size, temperature, and orbits of stars in binary systems by using this powerful technique. A Practical Guide to Lightcurve Photometry and Analysis contains all the material needed for readers to understand the theory, and avoid the practical pitfalls of lightcurve photometry. Detailed examples are given for obtaining data, and of course for the exciting and rewarding task of analyzing the data to determine the physical properties of the object. Any college student or amateur astronomer who wants to go beyond mere imaging with a CCD camera and enter the challenging world of "real science" via the lightcurves of asteroids and...

  8. Hadrons in compact stars

    Indian Academy of Sciences (India)

    At normal nuclear matter density, neutron star matter mainly consists of neutrons, protons and electrons. The particle population is so arranged as to attain a min- imum energy configuration maintaining electrical charge neutrality and chemical equilibrium. At higher baryon density, hyperon formation becomes energetically.

  9. Hard X ray lines from neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; La Padula, C.; Ubertini, P.

    1982-01-01

    Experimental evidence is presented and evaluated concerning the features of the hard X-ray spectra detected in a number of cosmic X-ray sources which contain a neutron star. The strong emission line at cyclotron resonance detected in the spectrum of Her XI at an energy of 58 keV is evaluated and the implications of this finding are discussed. Also examined is the presence of spectral features in the energy range 20-80 keV found in the spectra of gamma-ray bursts, which have been interpreted as cyclotron resonance from interstellar-gas-accreting neutron stars. The less understood finding of a variable emission line at approximately 70 keV in the spectrum of the Crab Pulsar is considered. It is determined that several features varying with time are present in the spectra of cosmic X-ray sources associated with neutron stars. If these features are due to cyclotron resonance, it is suggested that they provide a direct measurement of neutron star magnetic fields on the order of 10 to the 11th-10 to the 13th Gauss. However, the physical condition of the emitting region and its geometry are still quite obscure.

  10. A new deterministic model of strange stars

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Farook; Shit, G.C. [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Chakraborty, Koushik [Government Training College, Department of Physics, Hooghly, West Bengal (India); Kuhfittig, P.K.F. [Milwaukee School of Engineering, Department of Mathematics, Milwaukee, WI (United States); Rahman, Mosiur [Meghnad Saha Institute of Technology, Department of Mathematics, Kolkata (India)

    2014-10-15

    The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass-radius relation due to Buchdahl is satisfied in our model. We find the surface redshift (Z) corresponding to the compactness of the stars. Finally, from our results, we predict some characteristics of a strange star of radius 9.9 km. (orig.)

  11. Effects of the nuclear symmetry energy on gravitational waves from the axial W-modes of isolated neutron stars

    International Nuclear Information System (INIS)

    Wen, Dehua; Li, Baoan; Krastev, P.G.

    2010-01-01

    The frequencies and damping times of the axial w-mode oscillations of neutron stars are investigated using a nuclear equation of state (EOS) partially constrained by the available terrestrial laboratory data. It is found that the nuclear symmetry energy E sym (ρ), especially its high density behavior, plays an important role in determining both the eigen-frequencies and the damping times of these oscillations. (author)

  12. What CoRoT tells us about δ Scuti stars

    Directory of Open Access Journals (Sweden)

    Michel Eric

    2017-01-01

    Full Text Available Inspired by the so appealing example of red giants, where going from a handful of stars to thousands revealed the structure of the eigenspectrum, we inspected a large homogeneous set of around 1860 δ Scuti stars observed with CoRoT. This unique data set reveals a common regular pattern which appears to be in agreement with island modes featured by theoretical non-perturbative treatments of fast rotation. The comparison of these data with models and linear stability calculations suggests that spectra can be fruitfully characterized to first order by a few parameters which might play the role of seismic indices for δ Scuti stars, as Δv and vmax do for red giants. The existence of this pattern offers an observational support for guiding further theoretical works on fast rotation. It also provides a framework for further investigation of the observational material collected by CoRoT ([1] and Kepler ([2]. Finally, it sketches out the perspective of using δ Scuti stars pulsations for ensemble asteroseismology

  13. THE COOLING OF THE CASSIOPEIA A NEUTRON STAR AS A PROBE OF THE NUCLEAR SYMMETRY ENERGY AND NUCLEAR PASTA

    Energy Technology Data Exchange (ETDEWEB)

    Newton, William G.; Hooker, Joshua; Li, Bao-An [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce, TX 75429-3011 (United States); Murphy, Kyleah [Umpqua Community College, Roseburg, OR 97470 (United States)

    2013-12-10

    X-ray observations of the neutron star (NS) in the Cas A supernova remnant over the past decade suggest the star is undergoing a rapid drop in surface temperature of ≈2%-5.5%. One explanation suggests the rapid cooling is triggered by the onset of neutron superfluidity in the core of the star, causing enhanced neutrino emission from neutron Cooper pair breaking and formation (PBF). Using consistent NS crust and core equations of state (EOSs) and compositions, we explore the sensitivity of this interpretation to the density dependence of the symmetry energy L of the EOS used, and to the presence of enhanced neutrino cooling in the bubble phases of crustal ''nuclear pasta''. Modeling cooling over a conservative range of NS masses and envelope compositions, we find L ≲ 70 MeV, competitive with terrestrial experimental constraints and other astrophysical observations. For masses near the most likely mass of M ≳ 1.65 M {sub ☉}, the constraint becomes more restrictive 35 ≲ L ≲ 55 MeV. The inclusion of the bubble cooling processes decreases the cooling rate of the star during the PBF phase, matching the observed rate only when L ≲ 45 MeV, taking all masses into consideration, corresponding to NS radii ≲ 11 km.

  14. Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Leach, Matt [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pless, Shanti [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-06-05

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.

  15. Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, E.; Leach, M.; Pless, S.

    2013-06-01

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.

  16. Promotion of solar thermal energy - guide and comparison of experience

    Energy Technology Data Exchange (ETDEWEB)

    Ballot, E [ALTER Alsace (France)

    2004-01-01

    One of the objectives of the guide is to analyse the methods of the various partners of the project (Germany, Cyprus, Town of Barcelona and France) and to make a list with the most important ones, which could eventually be reproduced and adapted in other regions. Also, try to find out the problems that the various partners encounter (lack of information, technical and financial tools...), look for the best ways for developing the solar thermal energy and try to find out some answers from the stake holders of this domain and from our partners. (author)

  17. 2012 Australasian sky guide

    CERN Document Server

    Lomb, Nick

    2011-01-01

    Compact, easy to use and reliable, this popular guide contains everything you need to know about the southern night sky with monthly star maps, diagrams and details of all the year's exciting celestial events. Wherever you are in Australia or New Zealand, easy calculations allow you to determine when the Sun, Moon and planets will rise and set throughout the year. Also included is information on the latest astronomical findings from space probes and telescopes around the world.

  18. Neutron stars, magnetic fields, and gravitational waves

    International Nuclear Information System (INIS)

    Lamb, F.K.

    2001-01-01

    The r-modes of rapidly spinning young neutron stars have recently attracted attention as a promising source of detectable gravitational radiation. These neutron stars are expected to have magnetic fields ∼ 10 12 G. The r-mode velocity perturbation causes differential motion of the fluid in the star; this is a kinematic effect. In addition, the radiation-reaction associated with emission of gravitational radiation by r-waves drives additional differential fluid motions; this is a dynamic effect. These differential fluid motions distort the magnetic fields of neutron stars and may therefore play an important role in determining the structure of neutron star magnetic fields. If the stellar field is ∼ 10 16 (Ω/Ω B ) G or stronger, the usual r-modes are no longer normal modes of the star; here Ω and Ω B are the angular velocities of the star and at which mass shedding occurs. Much weaker magnetic fields can prevent gravitational radiation from amplifying the r-modes or damp existing r-mode oscillations on a relatively short timescale by extracting energy from the modes faster than gravitational wave emission can pump energy into them. The onset of proton superconductivity in the cores of newly formed magnetic neutron stars typically increases the effect on the r-modes of the magnetic field in the core by many orders of magnitude. Once the core has become superconducting, magnetic fields of the order of 10 12 G or greater are usually sufficient to damp r-modes that have been excited by emission of gravitational radiation and to suppress any further emission. A rapid drop in the strength of r-mode gravitational radiation from young neutron stars may therefore signal the onset of superconductivity in the core and provide a lower bound on the strength of the magnetic field there. Hence, measurements of r-mode gravitational waves from newly formed neutron stars may provide valuable diagnostic information about magnetic field strengths, cooling processes, and the

  19. Star Formation in Dusty Quasars

    Science.gov (United States)

    Lumsden, Stuart; Croom, Scott

    2012-04-01

    Quasar mode feedback is thought to be a crucial ingredient in galaxy formation for luminous merging and star-bursting systems at high redshift. The energy from the active nucleus should cause significant gas outflows, reducing the available free gas reservoir for future star formation. It is currently unknown which observational state best corresponds to the stage at which this "blowout" should occur. We intend to test one possible source population for this transition phase, by studying the molecular gas content in a small, statistically complete sample of 3 K-band selected reddened quasars from the AUS survey. All lie in the redshift range 2stars for form as well.

  20. Observational diagnostics of accretion on young stars and brown dwarfs

    Science.gov (United States)

    Stelzer, Beate; Argiroffi, Costanza

    I present a summary of recent observational constraints on the accretion properties of young stars and brown dwarfs with focus on the high-energy emission. In their T Tauri phase young stars assemble a few percent of their mass by accretion from a disk. Various observational signatures of disks around pre-main sequence stars and the ensuing accretion process are found in the IR and optical regime: e.g. excess emission above the stellar photosphere, strong and broad emission lines, optical veiling. At high energies evidence for accretion is less obvious, and the X-ray emission from stars has historically been ascribed to magnetically confined coronal plasmas. While being true for the bulk of the emission, new insight obtained from XMM-Newton and Chandra observations has unveiled contributions from accretion and outflow processes to the X-ray emission from young stars. Their smaller siblings, the brown dwarfs, have been shown to undergo a T Tauri phase on the basis of optical/IR observations of disks and measurements of accretion rates. Most re-cently, first evidence was found for X-rays produced by accretion in a young brown dwarf, complementing the suspected analogy between stars and substellar objects.

  1. The spectral energy distributions of isolated neutron stars in the resonant cyclotron scattering model

    Science.gov (United States)

    Tong, Hao; Xu, Renxin

    2013-03-01

    The X-ray dim isolated neutron stars (XDINSs) are peculiar pulsar-like objects, characterized by their very well Planck-like spectrum. In studying their spectral energy distributions, the optical/UV excess is a long standing problem. Recently, Kaplan et al. (2011) have measured the optical/UV excess for all seven sources, which is understandable in the resonant cyclotron scattering (RCS) model previously addressed. The RCS model calculations show that the RCS process can account for the observed optical/UV excess for most sources. The flat spectrum of RX J2143.0+0654 may due to contribution from bremsstrahlung emission of the electron system in addition to the RCS process.

  2. Astronomy of the milky way the observer’s guide to the northern sky

    CERN Document Server

    Inglis, Mike

    2017-01-01

    This second edition of Mike Inglis's classic guide to observing the Milky Way in the Northern Hemisphere updates all of the science with new findings from the astrophysics field, as well as featuring a larger format with entirely re-drawn maps. Newly laid out for ease of use with an increased number of images in color, it updates and improves the first edition to remain the most comprehensive book on the subject. One of the wonders of the universe we live in is the Milky Way, and this book provides a wonderful tour of its highlights for amateur astronomers. Northern hemisphere observers interested in viewing our own galaxy's finest features will find herein detailed descriptions for every constellation that the Milky Way passes through, including stars, double and multiple stars, emission nebulae, planetary nebulae, dark nebulae and supernovae remnants, open and globular clusters, and galaxies. Inglis also describes the one thing that is often left out of observing guides - the amazing star clouds of the Milk...

  3. Stellar winds and coronae of low-mass Population II/III stars

    Science.gov (United States)

    Suzuki, Takeru K.

    2018-06-01

    We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.

  4. Stellar winds and coronae of low-mass Population II/III stars

    Science.gov (United States)

    Suzuki, Takeru K.

    2018-04-01

    We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6-0.8) M⊙ and metallicity Z = (0-1) Z⊙, where M⊙ and Z⊙ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z⊙ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, \\dot{M}, is 4.5-20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ˜1-30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of \\dot{M} as \\dot{M}∝ L R_{\\star }^{11/9} M_{\\star }^{-10/9} T_eff^{11/2}[\\max (Z/Z_{⊙},0.01)]^{-1/5}, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.

  5. Symbiotic stars according to IRAS observations

    International Nuclear Information System (INIS)

    Luud, L.; Tuvikene, T.

    1987-01-01

    Symbiotic stars contained in Allen's catalog are examined with a view to establishing their coincidence with sources of far infrared radiation in the catalog of point sources observed with the IRAS satellite. Altogether, 72 symbiotic or suspected symbiotic objects have been identified. A list of the identified stars has been compiled, and the energy distributions in the infrared spectra of selected stars are given. It has been found that the presence of dust in symbiotic systems is a more widespread phenomenon than hitherto believed. Almost 40% of them are dust systems. Among them, objects with dust temperature of several tens of degrees kelvin have been found. It is shown that the only useful two-color diagram is the (K - m 12 )-(m 12 - m 25 ) diagram. Finally, attention is drawn to a type of symbiotic stars having cold components of the spectral class G; these require a special investigation

  6. Which of Kepler's Stars Flare?

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    The habitability of distant exoplanets is dependent upon many factors one of which is the activity of their host stars. To learn about which stars are most likely to flare, a recent study examines tens of thousands of stellar flares observed by Kepler.Need for a Broader SampleArtists rendering of a flaring dwarf star. [NASAs Goddard Space Flight Center/S. Wiessinger]Most of our understanding of what causes a star to flare is based on observations of the only star near enough to examine in detail the Sun. But in learning from a sample size of one, a challenge arises: we must determine which conclusions are unique to the Sun (or Sun-like stars), and which apply to other stellar types as well.Based on observations and modeling, astronomers think that stellar flares result from the reconnection of magnetic field lines in a stars outer atmosphere, the corona. The magnetic activity is thought to be driven by a dynamo caused by motions in the stars convective zone.HR diagram of the Kepler stars, with flaring main-sequence (yellow), giant (red) and A-star (green) stars in the authors sample indicated. [Van Doorsselaere et al. 2017]To test whether these ideas are true generally, we need to understand what types of stars exhibit flares, and what stellar properties correlate with flaring activity. A team of scientists led by Tom Van Doorsselaere (KU Leuven, Belgium) has now used an enormous sample of flares observed by Kepler to explore these statistics.Intriguing TrendsVan Doorsselaere and collaborators used a new automated flare detection and characterization algorithm to search through the raw light curves from Quarter 15 of the Kepler mission, building a sample of 16,850 flares on 6,662 stars. They then used these to study the dependence of the flare occurrence rate, duration, energy, and amplitude on the stellar spectral type and rotation period.This large statistical study led the authors to several interesting conclusions, including:Flare star incidence rate as a a

  7. A prescription and fast code for the long-term evolution of star clusters

    Science.gov (United States)

    Alexander, Poul E. R.; Gieles, Mark

    2012-06-01

    We introduce the star cluster evolution code Evolve Me A Cluster of StarS (EMACSS), a simple yet physically motivated computational model that describes the evolution of some fundamental properties of star clusters in static tidal fields. We base our prescription upon the flow of energy within the cluster, which is a constant fraction of the total energy per half-mass relaxation time. According to Hénon's predictions, this flow is independent of the precise mechanisms for energy production within the core, and therefore does not require a complete description of the many-body interactions therein. For a cluster of equal-mass stars, we use dynamical theory and analytic descriptions of escape mechanisms to construct a series of coupled differential equations expressing the evolution of cluster mass and radius. These equations are numerically solved using a fourth-order Runge-Kutta integration kernel, and the results benchmarked against a data base of direct N-body simulations. We use simulations containing a modest initial number of stars (1024 ≤N≤ 65 536) and point-mass tidal fields of various strengths. Our prescription is publicly available and reproduces the N-body results to within ˜10 per cent accuracy for the entire post-collapse evolution of star clusters.

  8. NICER Eyes on Bursting Stars

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    What happens to a neutron stars accretion disk when its surface briefly explodes? A new instrument recently deployed at the International Space Station (ISS) is now watching bursts from neutron stars and reporting back.Deploying a New X-Ray MissionLaunch of NICER aboard a Falcon 9 rocket in June 2017. [NASA/Tony Gray]In early June of 2017, a SpaceX Dragon capsule on a Falcon 9 rocket launched on a resupply mission to the ISS. The pressurized interior of the Dragon contained the usual manifest of crew supplies, spacewalk equipment, and vehicle hardware. But the unpressurized trunk of the capsule held something a little different: the Neutron star Interior Composition Explorer (NICER).In the two weeks following launch, NICER was extracted from the SpaceX Dragon capsule and installed on the ISS. And by the end of the month, the instrument was already collecting its first data set: observations of a bright X-ray burst from Aql X-1, a neutron star accreting matter from a low-mass binary companion.Impact of BurstsNICERs goal is to provide a new view of neutron-star physics at X-ray energies of 0.212 keV a window that allows us to explore bursts of energy that neutron stars sometimes emit from their surfaces.Artists impression of an X-ray binary, in which a compact object accretes material from a companion star. [ESA/NASA/Felix Mirabel]In X-ray burster systems, hydrogen- and helium-rich material from a low-mass companion star piles up in an accretion disk around the neutron star. This material slowly funnels onto the neutron stars surface, forming a layer that gravitationally compresses and eventually becomes so dense and hot that runaway nuclear fusion ignites.Within seconds, the layer of material is burned up, producing a burst of emission from the neutron star that outshines even the inner regions of the hot accretion disk. Then more material funnels onto the neutron star and the process begins again.Though we have a good picture of the physics that causes these bursts

  9. VUV Spectroscopy of the Sun as a Star

    Science.gov (United States)

    Kankelborg, Charles; Philip, Judge; Winebarger, Amy R.; Kobayashi, Ken; Smart, Roy

    2017-08-01

    We describe a new sounding rocket mission to obtain the first high resolution, high quality VUV (100-200 nm) spectrum of the Sun-as-a-star. Our immediate science goal is to understand better the processes of chromospheric and coronal heating. HST data exist for a dozen or so Sun-like stars of a quality already beyond our ability to construct a comparable sun-as-a-star UV spectrum. The solar spectrum we obtain will enable us to understand the nature of magnetic energy dissipation as a Sun-like star evolves, and the dependence of magnetic activity on stellar mass and metallicity. This poster presents the instrument design, scientific prospects, and broader impacts of the proposed mission.

  10. Relaxation near Supermassive Black Holes Driven by Nuclear Spiral Arms: Anisotropic Hypervelocity Stars, S-stars, and Tidal Disruption Events

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, Adrian S. [Institute for Advanced Study, School of Natural Sciences, Einstein Drive, Princeton, NJ 08540 (United States); Perets, Hagai B., E-mail: hamers@ias.edu [Technion—Israel Institute of Technology, Haifa 32000 (Israel)

    2017-09-10

    Nuclear spiral arms are small-scale transient spiral structures found in the centers of galaxies. Similarly to their galactic-scale counterparts, nuclear spiral arms can perturb the orbits of stars. In the case of the Galactic center (GC), these perturbations can affect the orbits of stars and binaries in a region extending to several hundred parsecs around the supermassive black hole (SMBH), causing diffusion in orbital energy and angular momentum. This diffusion process can drive stars and binaries to close approaches with the SMBH, disrupting single stars in tidal disruption events (TDEs), or disrupting binaries, leaving a star tightly bound to the SMBH and an unbound star escaping the galaxy, i.e., a hypervelocity star (HVS). Here, we consider diffusion by nuclear spiral arms in galactic nuclei, specifically the Milky Way GC. We determine nuclear-spiral-arm-driven diffusion rates using test-particle integrations and compute disruption rates. Our TDE rates are up to 20% higher compared to relaxation by single stars. For binaries, the enhancement is up to a factor of ∼100, and our rates are comparable to the observed numbers of HVSs and S-stars. Our scenario is complementary to relaxation driven by massive perturbers. In addition, our rates depend on the inclination of the binary with respect to the Galactic plane. Therefore, our scenario provides a novel potential source for the observed anisotropic distribution of HVSs. Nuclear spiral arms may also be important for accelerating the coalescence of binary SMBHs and for supplying nuclear star clusters with stars and gas.

  11. Neutron Skins and Neutron Stars in the Multimessenger Era

    Science.gov (United States)

    Fattoyev, F. J.; Piekarewicz, J.; Horowitz, C. J.

    2018-04-01

    The historical first detection of a binary neutron star merger by the LIGO-Virgo Collaboration [B. P. Abbott et al., Phys. Rev. Lett. 119, 161101 (2017), 10.1103/PhysRevLett.119.161101] is providing fundamental new insights into the astrophysical site for the r process and on the nature of dense matter. A set of realistic models of the equation of state (EOS) that yield an accurate description of the properties of finite nuclei, support neutron stars of two solar masses, and provide a Lorentz covariant extrapolation to dense matter are used to confront its predictions against tidal polarizabilities extracted from the gravitational-wave data. Given the sensitivity of the gravitational-wave signal to the underlying EOS, limits on the tidal polarizability inferred from the observation translate into constraints on the neutron-star radius. Based on these constraints, models that predict a stiff symmetry energy, and thus large stellar radii, can be ruled out. Indeed, we deduce an upper limit on the radius of a 1.4 M⊙ neutron star of R⋆1.4Pb 208 to the symmetry energy, albeit at a lower density, we infer a corresponding upper limit of about Rskin208≲0.25 fm . However, if the upcoming PREX-II experiment measures a significantly thicker skin, this may be evidence of a softening of the symmetry energy at high densities—likely indicative of a phase transition in the interior of neutron stars.

  12. SEE Action Guide for States: Guidance on Establishing and Maintaining Technical Reference Manuals for Energy Efficiency Measures

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-06-01

    The goal of this guide is to support the development, maintenance, and use of accurate and reliable Technical Reference Manuals (TRMs). TRMs provide information primarily used for estimating the energy and demand savings of end-use energy efficiency measures associated with utility customer-funded efficiency programs.

  13. O stars and Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Conti, P.S.; Underhill, A.B.; Jordan, S.; Thomas, R.

    1988-01-01

    Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented

  14. O stars and Wolf-Rayet stars

    Science.gov (United States)

    Conti, Peter S.; Underhill, Anne B.; Jordan, Stuart (Editor); Thomas, Richard (Editor)

    1988-01-01

    Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented.

  15. 77 FR 55212 - North Star Hydro Services CA, LLC; Notice of Preliminary Permit Application Accepted for Filing...

    Science.gov (United States)

    2012-09-07

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14379-000] North Star Hydro..., Motions To Intervene, and Competing Applications On March 30, 2012, North Star Hydro Services CA, LLC... approximately 3.8 gigawatthours. Applicant Contact: David Holland, North Star Hydro Services CA, LLC, 1110 West...

  16. Utility Energy Services Contracts Guide

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-09-01

    The UESC Guide is a compilation of samples and templates developed as a resource to help contracting officers implement task orders for UESCs under existing U.S. General Services Administration areawide contracts.

  17. A robust star identification algorithm with star shortlisting

    Science.gov (United States)

    Mehta, Deval Samirbhai; Chen, Shoushun; Low, Kay Soon

    2018-05-01

    A star tracker provides the most accurate attitude solution in terms of arc seconds compared to the other existing attitude sensors. When no prior attitude information is available, it operates in "Lost-In-Space (LIS)" mode. Star pattern recognition, also known as star identification algorithm, forms the most crucial part of a star tracker in the LIS mode. Recognition reliability and speed are the two most important parameters of a star pattern recognition technique. In this paper, a novel star identification algorithm with star ID shortlisting is proposed. Firstly, the star IDs are shortlisted based on worst-case patch mismatch, and later stars are identified in the image by an initial match confirmed with a running sequential angular match technique. The proposed idea is tested on 16,200 simulated star images having magnitude uncertainty, noise stars, positional deviation, and varying size of the field of view. The proposed idea is also benchmarked with the state-of-the-art star pattern recognition techniques. Finally, the real-time performance of the proposed technique is tested on the 3104 real star images captured by a star tracker SST-20S currently mounted on a satellite. The proposed technique can achieve an identification accuracy of 98% and takes only 8.2 ms for identification on real images. Simulation and real-time results depict that the proposed technique is highly robust and achieves a high speed of identification suitable for actual space applications.

  18. Star-Branched Polymers (Star Polymers)

    KAUST Repository

    Hirao, Akira

    2015-09-01

    The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm ABC, 9-arm ABC, 12-arm ABC, 13-arm ABCD, 9-arm AB, 17-arm AB, 33-arm AB, 7-arm ABC, 15-arm ABCD, and 31-arm ABCDE miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

  19. A guide for business promotion in the energy sector; Wegweiser zur Unternehmensfoerderung im Energiebereich

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Investments in energy-saving measures are economical: The conscious use of electricity saves money, increases the yields and contributes to the climate protection. Especially, the promotion of small and medium-sized enterprises in the areas of energy efficiency and climate protection forms the main focus of the funding programmes of the Federal Ministry of Economics and Technology (Berlin, Federal Republic of Germany). The funding programmes range from financial grants for energy consulting and implementation of concrete energy saving measures in a company through financial grants for the development of innovative products and services up to a support when exporting energy efficient technologies. The brochure is supposed to be a guide for the advanced support package. The seven funding programmes of the Federal Ministry of Economics and Technology in the energy sector are presented.

  20. Solar Energy Installers Curriculum Guides. Book I.

    Science.gov (United States)

    Walker, Gene C.

    This first volume of a comprehensive curriculum guide for the heating-ventilation-air conditioning-refrigeration-solar student is designed to assist high school area vocational centers or community college instructors in the implementation and operation of comfort training programs. Following an introductory section, the guide provides job…

  1. Ultraviolet radiation from stellar flares and the coronal X-ray emission for dwarf-Me stars

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, J.G.; Butler, C.J. (Armagh Observatory, Northern Ireland (UK))

    1985-01-31

    The authors correlate Einstein observations of the X-ray flux of quiescent dMe stars with the time-averaged energy emitted by flares in the Johnson-U band, showing that the X-ray energy emitted by the coronae of these stars is about an order of magnitude greater than the U-band flare energy. From the estimate of the ratio of the total radiation emitted to the U-band flux, it is possible that, if a similar amount of energy were dissipated in the stellar atmosphere, then the observed flare events could heat the coronae of these stars.

  2. PSR1987A: the case for strange-quark stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-01-01

    The new fast pulsar observed in the remnant of SN1987A, together with other considerations, provide evidence that there are two types of collapsed stars: neutron stars, having moderate central densities and subject to the usual mass constraint, and strange-quark-matter stars. We show that (i) all known pulsar masses and frequencies, with the exception of the new one, can be accounted for by plausible neutron star models; (ii) no known neutron star model can withstand the fast rotation of the new pulsar unless the central energy density is ∼ 15 that of normal nuclei, at which densities hadrons cannot plausibly exist as constituents; and (iii) if strange-quark matter is the true ground state of the strong interactions, strange-quark stars can sustain the high rotation imputed to the new pulsar. In the absence of another plausible structure that can withstand the fast rotation, we provisionally infer that the new pulsar is such a star. (author)

  3. Building America Best Practices Series, Volume 9: Builders Challenge Guide to 40% Whole-House Energy Savings in the Hot-Dry and Mixed-Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Michael C.; Gilbride, Theresa L.; Hefty, Marye G.; Williamson, Jennifer L.; Ruiz, Kathleen A.; Bartlett, Rosemarie; Love, Pat M.

    2009-10-23

    This best practices guide is the ninth in a series of guides for builders produced by the U.S. Department of Energy’s Building America Program. This guide book is a resource to help builders design and construct homes that are among the most energy-efficient available, while addressing issues such as building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the hot-dry and mixed-dry climates can achieve homes that have whole house energy savings of 40% over the Building America benchmark (a home built to mid-1990s building practices roughly equivalent to the 1993 Model Energy Code) with no added overall costs for consumers. These best practices are based on the results of research and demonstration projects conducted by Building America’s research teams. The guide includes information for managers, designers, marketers, site supervisors, and subcontractors, as well as case studies of builders who are successfully building homes that cut energy use by 40% in the hot-dry and mixed-dry climates.

  4. Energy Renovations: Volume 14: HVAC - A Guide for Contractors to Share with Homeowners

    Energy Technology Data Exchange (ETDEWEB)

    Gilbride, Theresa L.; Baechler, Michael C.; Hefty, Marye G.; Hand, James R.; Love, Pat M.

    2011-08-29

    This report was prepared by PNNL for DOE's Building America program and is intended as a guide that energy performance contractors can share with homeowners to describe various energy-efficient options for heating, cooling, and ventilating existing homes. The report provides descriptions of many common and not-so-common HVAC systems, including their advantages and disadvantages, efficiency ranges and characteristics of high-performance models, typical costs, and climate considerations. The report also provides decision trees and tables of useful information for homeowners who are making decisions about adding, replacing, or upgrading existing HVAC equipment in their homes. Information regarding home energy performance assessments (audits) and combustion safety issues when replacing HVAC equipment are also provided.

  5. Cyclotron Lines in Accreting Neutron Star Spectra

    Science.gov (United States)

    Wilms, Jörn; Schönherr, Gabriele; Schmid, Julia; Dauser, Thomas; Kreykenbohm, Ingo

    2009-05-01

    Cyclotron lines are formed through transitions of electrons between discrete Landau levels in the accretion columns of accreting neutron stars with strong (1012 G) magnetic fields. We summarize recent results on the formation of the spectral continuum of such systems, describe recent advances in the modeling of the lines based on a modification of the commonly used Monte Carlo approach, and discuss new results on the dependence of the measured cyclotron line energy from the luminosity of transient neutron star systems. Finally, we show that Simbol-X will be ideally suited to build and improve the observational database of accreting and strongly magnetized neutron stars.

  6. Electron cyclotron maser instability (ECMI in strong magnetic guide field reconnection

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2017-08-01

    Full Text Available The ECMI model of electromagnetic radiation from electron holes is shown to be applicable to spontaneous magnetic reconnection. We apply it to reconnection in strong current-aligned magnetic guide fields. Such guide fields participate only passively in reconnection, which occurs in the antiparallel components to both sides of the guide-field-aligned current sheets with current carried by kinetic Alfvén waves. Reconnection generates long (the order of hundreds of electron inertial scales electron exhaust regions at the reconnection site X point, which are extended perpendicular to the current and the guide fields. Exhausts contain a strongly density-depleted hot electron component and have properties similar to electron holes. Exhaust electron momentum space distributions are highly deformed, exhibiting steep gradients transverse to both the reconnecting and guide fields. Such properties suggest application of the ECMI mechanism with the fundamental ECMI X-mode emission beneath the nonrelativistic guide field cyclotron frequency in localized source regions. An outline of the mechanism and its prospects is given. Potential applications are the kilometric radiation (AKR in auroral physics, solar radio emissions during flares, planetary emissions and astrophysical scenarios (radiation from stars and compact objects involving the presence of strong magnetic fields and field-aligned currents. Drift of the exhausts along the guide field maps the local field and plasma properties. Escape of radiation from the exhaust and radiation source region still poses a problem. The mechanism can be studied in 2-D particle simulations of strong guide field reconnection which favours 2-D, mapping the deformation of the electron distribution perpendicular to the guide field, and using it in the numerical calculation of the ECMI growth rate. The mechanism suggests also that reconnection in general may become a source of the ECMI with or without guide fields. This is

  7. Electron cyclotron maser instability (ECMI) in strong magnetic guide field reconnection

    Science.gov (United States)

    Treumann, Rudolf A.; Baumjohann, Wolfgang

    2017-08-01

    The ECMI model of electromagnetic radiation from electron holes is shown to be applicable to spontaneous magnetic reconnection. We apply it to reconnection in strong current-aligned magnetic guide fields. Such guide fields participate only passively in reconnection, which occurs in the antiparallel components to both sides of the guide-field-aligned current sheets with current carried by kinetic Alfvén waves. Reconnection generates long (the order of hundreds of electron inertial scales) electron exhaust regions at the reconnection site X point, which are extended perpendicular to the current and the guide fields. Exhausts contain a strongly density-depleted hot electron component and have properties similar to electron holes. Exhaust electron momentum space distributions are highly deformed, exhibiting steep gradients transverse to both the reconnecting and guide fields. Such properties suggest application of the ECMI mechanism with the fundamental ECMI X-mode emission beneath the nonrelativistic guide field cyclotron frequency in localized source regions. An outline of the mechanism and its prospects is given. Potential applications are the kilometric radiation (AKR) in auroral physics, solar radio emissions during flares, planetary emissions and astrophysical scenarios (radiation from stars and compact objects) involving the presence of strong magnetic fields and field-aligned currents. Drift of the exhausts along the guide field maps the local field and plasma properties. Escape of radiation from the exhaust and radiation source region still poses a problem. The mechanism can be studied in 2-D particle simulations of strong guide field reconnection which favours 2-D, mapping the deformation of the electron distribution perpendicular to the guide field, and using it in the numerical calculation of the ECMI growth rate. The mechanism suggests also that reconnection in general may become a source of the ECMI with or without guide fields. This is of particular

  8. 77 FR 73651 - North Star Hydro Services, CA LLC; Notice of Preliminary Permit Application Accepted for Filing...

    Science.gov (United States)

    2012-12-11

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14465-000] North Star Hydro..., Motions To Intervene, and Competing Applications On November 6, 2012, North Star Hydro Services CA, LLC.... Applicant Contact: Mr. David Holland, North Star Hydro Services CA, LLC, 1110 West 131st Street South, Jenks...

  9. Neutron stars as probes of extreme energy density matter

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... and the orbital period decay due to the emission of gravitational radiation. ˙P = −. 192π ... masses severely restrict the EoS of neutron star matter. Masses ..... (9) Is unstable burning of carbon (C) the real cause of superbursts?

  10. Intense electromagnetic outbursts from collapsing hypermassive neutron stars

    Science.gov (United States)

    Lehner, Luis; Palenzuela, Carlos; Liebling, Steven L.; Thompson, Christopher; Hanna, Chad

    2012-11-01

    We study the gravitational collapse of a magnetized neutron star using a novel numerical approach able to capture both the dynamics of the star and the behavior of the surrounding plasma. In this approach, a fully general relativistic magnetohydrodynamics implementation models the collapse of the star and provides appropriate boundary conditions to a force-free model which describes the stellar exterior. We validate this strategy by comparing with known results for the rotating monopole and aligned rotator solutions and then apply it to study both rotating and nonrotating stellar collapse scenarios and contrast the behavior with what is obtained when employing the electrovacuum approximation outside the star. The nonrotating electrovacuum collapse is shown to agree qualitatively with a Newtonian model of the electromagnetic field outside a collapsing star. We illustrate and discuss a fundamental difference between the force-free and electrovacuum solutions, involving the appearance of large zones of electric-dominated field in the vacuum case. This provides a clear demonstration of how dissipative singularities appear generically in the nonlinear time evolution of force-free fluids. In both the rotating and nonrotating cases, our simulations indicate that the collapse induces a strong electromagnetic transient, which leaves behind an uncharged, unmagnetized Kerr black hole. In the case of submillisecond rotation, the magnetic field experiences strong winding, and the transient carries much more energy. This result has important implications for models of gamma-ray bursts. Even when the neutron star is surrounded by an accretion torus (as in binary merger and collapsar scenarios), a magnetosphere may emerge through a dynamo process operating in a surface shear layer. When this rapidly rotating magnetar collapses to a black hole, the electromagnetic energy released can compete with the later output in a Blandford-Znajek jet. Much less electromagnetic energy is

  11. Dependence of absolute magnitudes (energies) of flares on the cluster age containing flare stars

    International Nuclear Information System (INIS)

    Parsamyan, Eh.S.

    1976-01-01

    Dependences between Δmsub(u) and msub(u) are given for the Orion, NGC 7000, Pleiades and Praesepe aggregations. Maximum absolute values of flares have been calculated for stars with different luminosities. It has been shown that the values of flares can be limited by a straight line which gives the representation on the distribution of maximum values of amplitudes for the stars with different luminosities in an aggregation. Presented are k and m 0 parameters characterizing the lines fot the Orion, NGC 7000, Pleiades and Praesepe aggregation and their age T dependence. From the dependence between k (angular coefficient of straight lines) and lgT for the aggregation with known T the age of those aggregation involving a great amount of flaring stars can be found. The age of flaring stars in the neighbourhood of the Sun has been determined. The age of UV Ceti has been shown by an order to exceed that of the rest stars

  12. Polarized X-Ray Emission from Magnetized Neutron Stars: Signature of Strong-Field Vacuum Polarization

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C.

    2003-08-01

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  13. Polarized x-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization.

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C G

    2003-08-15

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  14. Gravity Defied From Potato Asteroids to Magnetised Neutron Stars

    Indian Academy of Sciences (India)

    Gravity Defied. From Potato Asteroids to Magnetised Neutron Stars. 2. ... objects that just missed being stars in this particular install- ment. 1. .... However, the total energy that can be made .... trial metals in which the electrons form a degenerate Fermi gas. ... In deuterium fusion, a deuterium nucleus and a proton combine to.

  15. Statistical investigation of flare stars. III. Flare stars in the general galactic star field

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.; Ambaryan, V.V.; Garibdzhanyan, A.T.; Mirzoyan, A.L.

    1989-01-01

    Some questions relating to the existence of a large number of flare stars in the general star field of the Galaxy are discussed. It is shown that only a small proportion of them can be found by photographic observations, and the fraction of field flare stars among such stars found in the regions of star clusters and associations does not exceed 10%. The ratio of the numbers of flare stars of the foreground and the background for a particular system depends on its distance, reaching zero at a distance of about 500 pc. The spatial density of flare stars in the Pleiades is at least two orders of magnitude greater than in the general galactic field. A lower limit for the number of flare stars in the Galaxy is estimated at 4.2 ·10 9 , and the number of nonflare red dwarfs at 2.1·10 10 . There are grounds for believing that they were all formed in star clusters and associations

  16. Red but not dead: unveiling the star-forming far-infrared spectral energy distribution of SpARCS brightest cluster galaxies at 0 < z < 1.8

    Science.gov (United States)

    Bonaventura, N. R.; Webb, T. M. A.; Muzzin, A.; Noble, A.; Lidman, C.; Wilson, G.; Yee, H. K. C.; Geach, J.; Hezaveh, Y.; Shupe, D.; Surace, J.

    2017-08-01

    We present the results of a Spitzer/Herschel infrared photometric analysis of the largest (716) and the highest-redshift (z = 1.8) sample of brightest cluster galaxies (BCGs), those from the Spitzer Adaptation of the Red-Sequence Cluster Survey Given the tension that exists between model predictions and recent observations of BCGs at z energy distributions (SEDs) to a variety of model templates in the literature, we identify the major sources of their infrared energy output, in multiple redshift bins between 0 solar masses per year down to z = 0.5. This discovery challenges the accepted belief that BCGs should only passively evolve through a series of gas-poor, minor mergers since z ˜ 4, but agrees with an improved semi-analytic model of hierarchical structure formation that predicts star-forming BCGs throughout the epoch considered. We attribute the star formation inferred from the stacked infrared SEDs to both major and minor 'wet' (gas-rich) mergers, based on a lack of key signatures (to date) of cooling-flow-induced star formation, as well as a number of observational and simulation-based studies that support this scenario.

  17. Constraining neutron star matter with Quantum Chromodynamics

    CERN Document Server

    Kurkela, Aleksi; Schaffner-Bielich, Jurgen; Vuorinen, Aleksi

    2014-01-01

    In recent years, there have been several successful attempts to constrain the equation of state of neutron star matter using input from low-energy nuclear physics and observational data. We demonstrate that significant further restrictions can be placed by additionally requiring the pressure to approach that of deconfined quark matter at high densities. Remarkably, the new constraints turn out to be highly insensitive to the amount --- or even presence --- of quark matter inside the stars.

  18. Symbiotic stars

    International Nuclear Information System (INIS)

    Boyarchuk, A.A.

    1975-01-01

    There are some arguments that the symbiotic stars are binary, where one component is a red giant and the other component is a small hot star which is exciting a nebula. The symbiotic stars belong to the old disc population. Probably, symbiotic stars are just such an evolutionary stage for double stars as planetary nebulae for single stars. (Auth.)

  19. Atypical Mg-poor Milky Way Field Stars with Globular Cluster Second-generation-like Chemical Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Trincado, J. G.; Geisler, D.; Tang, B.; Villanova, S.; Mennickent, R. E. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Zamora, O.; García-Hernández, D. A.; Dell’Agli, F.; Prieto, Carlos Allende [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Souto, Diogo; Cunha, Katia [Observatório Nacional, Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400 (Brazil); Schiavon, R. P. [Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Hasselquist, Sten [New Mexico State University, Las Cruces, NM 88003 (United States); Shetrone, M. [University of Texas at Austin, McDonald Observatory, Fort Davis, TX 79734 (United States); Vieira, K. [Centro de Investigaciones de Astronomía, AP 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Zasowski, G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Sobeck, J.; Hayes, C. R.; Majewski, S. R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22903 (United States); Placco, V. M., E-mail: jfernandezt@astro-udec.cl, E-mail: jfernandezt87@gmail.com [Department of Physics and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556 (United States); and others

    2017-09-01

    We report the peculiar chemical abundance patterns of 11 atypical Milky Way (MW) field red giant stars observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). These atypical giants exhibit strong Al and N enhancements accompanied by C and Mg depletions, strikingly similar to those observed in the so-called second-generation (SG) stars of globular clusters (GCs). Remarkably, we find low Mg abundances ([Mg/Fe] < 0.0) together with strong Al and N overabundances in the majority (5/7) of the metal-rich ([Fe/H] ≳ −1.0) sample stars, which is at odds with actual observations of SG stars in Galactic GCs of similar metallicities. This chemical pattern is unique and unprecedented among MW stars, posing urgent questions about its origin. These atypical stars could be former SG stars of dissolved GCs formed with intrinsically lower abundances of Mg and enriched Al (subsequently self-polluted by massive AGB stars) or the result of exotic binary systems. We speculate that the stars Mg-deficiency as well as the orbital properties suggest that they could have an extragalactic origin. This discovery should guide future dedicated spectroscopic searches of atypical stellar chemical patterns in our Galaxy, a fundamental step forward to understanding the Galactic formation and evolution.

  20. Gamma-Ray Bursts from Neutron Star Kicks

    Science.gov (United States)

    Huang, Y. F.; Dai, Z. G.; Lu, T.; Cheng, K. S.; Wu, X. F.

    2003-09-01

    The idea that gamma-ray bursts might be a phenomenon associated with neutron star kicks was first proposed by Dar & Plaga. Here we study this mechanism in more detail and point out that the neutron star should be a high-speed one (with proper motion larger than ~1000 km s-1). It is shown that the model agrees well with observations in many aspects, such as the energetics, the event rate, the collimation, the bimodal distribution of durations, the narrowly clustered intrinsic energy, and the association of gamma-ray bursts with supernovae and star-forming regions. We also discuss the implications of this model on the neutron star kick mechanism and suggest that the high kick speed was probably acquired as the result of the electromagnetic rocket effect of a millisecond magnetar with an off-centered magnetic dipole.