Science.gov

Sample records for co-sponsors american vacuum

  1. LTC American`s, Inc. vacuum blasting machine: Baseline report

    SciTech Connect

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC 1073 Vacuum Blasting Machine uses a high-capacity, direct-pressure blasting system which incorporates a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast. It incorporates a vacuum system which removes dust and debris from the surface as it is blasted. The safety and health evaluation during the testing focused on two main areas of exposure: dust and noise.

  2. NASA and Industry Partners Co-sponsor 2015 Unmanned Aircraft Systems Traffic Management (UTM) Convention

    NASA Image and Video Library

    2015-08-07

    With issues about drones becoming front page news, NASA recently co-sponsored the 2015 Unmanned Aerial Systems Traffic Management Convention. Held at NASA’s Ames Research Center, the event brought together representatives from the public, from industry, academia, government and the international community to shape the future of low-altitude air traffic management.

  3. 76 FR 70722 - Request for Co-Sponsors for the Office of Healthcare Quality's Programs To Strengthen...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-15

    ... infections exact a significant toll on human life. They are among the leading causes of preventable death in... HUMAN SERVICES Request for Co-Sponsors for the Office of Healthcare Quality's Programs To Strengthen...: Department of Health and Human Services, Office of the Secretary, ] Office of the Assistant Secretary...

  4. 75 FR 16125 - Call for Co-Sponsors for Office of Healthcare Quality's Programs to Strengthen Coordination and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ... (HAIs) exact a significant toll on human life. They are among the leading causes of preventable death in... HUMAN SERVICES Call for Co-Sponsors for Office of Healthcare Quality's Programs to Strengthen...: Department of Health and Human Services, Office of the Secretary, Office of Public Health and Science,...

  5. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG. Jack Boyd talk of working in the same 6ft w.t. group as Carol Mead.

  6. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofsetter and Carol Mead co-sponsored by the AAAG. clockwise Jack Boyd, Miss Mead daughter of Carol Mead, Carol Mead and Carolyn Hofstetter

  7. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG.. Left to right Barbara Miller, Ames EEO, Computers Carolyn Hofstetter and Carol Mead

  8. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG. Left to right Barbara Miller, Ames EEO, Computers Carolyn Hofstetter and Carol Mead

  9. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG. Left to right Computers Carolyn Hofstetter, Carol Mead and Jack Boyd

  10. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG. Left to right Barbara Miller, Ames EEO, Computers Carolyn Hoffstetter and Carol Mead, talking to Carolyn Hofstetter is Arlene Spencer

  11. Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG.

    NASA Image and Video Library

    2017-02-01

    Ames Women's Influence Network (WIN) Hidden Figures talk with "Computers" Carolyn Hofstetter and Carol Mead co-sponsored by the AAAG. Group photo Front Row left to right; Carolyn Hofstetter, Jack Boyd, Carol Mead Middle Row: Kathy Lee, Annette Randall, Trincella Lewis, Ann Mead (daughter to Carol Mead), Vanessa Kuroda, Netti Halcomb Roozeboom Back Row; Dr Barbara Miller, Dr Wendy Okolo, Denise Snow, Leedjia Svec, Erika Rodriquez, Rhonda Baker, Ray Gilstrap, Glenn Bugos

  12. Vacuum: From Art to Exact Science.

    ERIC Educational Resources Information Center

    Lafferty, James M.

    1981-01-01

    Reviews the history of vacuum technology. Includes vacuum pump developments (mechanical, ion, and cyrogenic pumps), measurement techniques, the development of the American Vacuum Society, and electronics in vacuum technology. (JN)

  13. The New American Home: Las Vegas, Nevada -- 2003

    SciTech Connect

    2002-12-01

    The New American Home is an annual showcase project designed by committee and co-sponsored by the National Association of Home Builder’s National Council of the Housing Industry (NCHI) and Builder Magazine. This year it was a building project for Amland D

  14. VACUUM TRAP

    DOEpatents

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  15. Vacuum Technology

    SciTech Connect

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  16. Vacuum Virtues

    ERIC Educational Resources Information Center

    Rathey, Allen

    2007-01-01

    Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

  17. Vacuum Virtues

    ERIC Educational Resources Information Center

    Rathey, Allen

    2007-01-01

    Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

  18. Vacuum mechatronics

    NASA Technical Reports Server (NTRS)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  19. Gravitational vacuum

    NASA Astrophysics Data System (ADS)

    Grigoryan, L. S.; Saakyan, G. S.

    1984-09-01

    The existence of a special gravitational vacuum is considered in this paper. A phenomenological method differing from the traditional Einsteinian formalization is utilized. Vacuum, metric and matter form a complex determined by field equations and at great distances from gravitational masses vacuum effects are small but could be large in powerful fields. Singularities and black holes justify the approach as well as the Ambartsmyan theory concerning the existence of supermassive and superdense prestallar bodies that then disintegrate. A theory for these superdense bodies is developed involving gravitational field equations that describe the vacuum by an energy momentum tensor and define the field and mass distribution. Computations based on the theory for gravitational radii with incompressible liquid models adequately reflecting real conditions indicate that a gravitational vacuum could have considerable effects on superdense stars and could have radical effects for very large masses.

  20. Vacuum phenomenon.

    PubMed

    Yanagawa, Youichi; Ohsaka, Hiromichi; Jitsuiki, Kei; Yoshizawa, Toshihiko; Takeuchi, Ikuto; Omori, Kazuhiko; Oode, Yasumasa; Ishikawa, Kouhei

    2016-08-01

    This article describes the theory of the formation of the vacuum phenomenon (VP), the detection of the VP, the different medical causes, the different locations of the presentation of the VP, and the differential diagnoses. In the human body, the cavitation effect is recognized on radiological studies; it is called the VP. The mechanism responsible for the formation of the VP is as follows: if an enclosed tissue space is allowed to expand as a rebound phenomenon after an external impact, the volume within the enclosed space will increase. In the setting of expanding volume, the pressure within the space will decrease. The solubility of the gas in the enclosed space will decrease as the pressure of the space decreases. Decreased solubility allows a gas to leave a solution. Clinically, the pathologies associated with the VP have been reported to mainly include the normal joint motion, degeneration of the intervertebral discs or joints, and trauma. The frequent use of CT for trauma patients and the high spatial resolution of CT images might produce the greatest number of chances to detect the VP in trauma patients. The VP is observed at locations that experience a traumatic impact; thus, an analysis of the VP may be useful for elucidating the mechanism of an injury. When the VP is located in the abdomen, it is important to include perforation of the digestive tract in the differential diagnosis. The presence of the VP in trauma patients does not itself influence the final outcome.

  1. Vacuum mechatronics. Proceedings.

    NASA Astrophysics Data System (ADS)

    Belinski, S. E.; Shirazi, M.; Hackwood, S.; Beni, G.

    The discipline of vacuum mechatronics is the design and development of vacuum-compatible, computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. Vacuum mechantronics is relevant to research engineers in integrated circuit manufacturing, surface physics, food processing, biotechnology, materials handling, space sciences and manufacturing.

  2. Quantum vacuum noise in physics and cosmology.

    PubMed

    Davies, P. C. W.

    2001-09-01

    The concept of the vacuum in quantum field theory is a subtle one. Vacuum states have a rich and complex set of properties that produce distinctive, though usually exceedingly small, physical effects. Quantum vacuum noise is familiar in optical and electronic devices, but in this paper I wish to consider extending the discussion to systems in which gravitation, or large accelerations, are important. This leads to the prediction of vacuum friction: The quantum vacuum can act in a manner reminiscent of a viscous fluid. One result is that rapidly changing gravitational fields can create particles from the vacuum, and in turn the backreaction on the gravitational dynamics operates like a damping force. I consider such effects in early universe cosmology and the theory of quantum black holes, including the possibility that the large-scale structure of the universe might be produced by quantum vacuum noise in an early inflationary phase. I also discuss the curious phenomenon that an observer who accelerates through a quantum vacuum perceives a bath of thermal radiation closely analogous to Hawking radiation from black holes, even though an inertial observer registers no particles. The effects predicted raise very deep and unresolved issues about the nature of quantum particles, the role of the observer, and the relationship between the quantum vacuum and the concepts of information and entropy. (c) 2001 American Institute of Physics.

  3. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  4. Natural vacuum electronics

    NASA Technical Reports Server (NTRS)

    Leggett, Nickolaus

    1990-01-01

    The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

  5. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  6. Vacuum sources in obstetrics.

    PubMed

    Wiper, D W; Duchon, M A; Muise, K L

    1996-06-01

    To characterize the performance of vacuum equipment used in operative vaginal deliveries. We measured wall suction in eight Cleveland area labor-and-delivery units. Additionally, we tested samples of hand-operated and electric vacuum pumps. For each apparatus we recorded vacuum in millimeters of mercury using a calibrated, diaphragm-type gauge. We calculated mean maximal vacuum. Work required to produce 500 mm Hg of vacuum was determined for the hand-operated pumps. At increments of vacuum, we compared the vacuum displayed by the gauge head included with the device to our standard. Mean wall suction was 494 mm Hg (range, 248-655). As compared to the Mity-vac, the CMI hand-operated pump needed significantly more work to generate 500 mm Hg of vacuum. Electric pumps produced a reliable and consistent vacuum. Gauges included with the pump had an average error of 4% over 400-600 mm Hg. Wall suction was an unreliable source of vacuum. The two hand-operated pumps tested required significantly different amounts of work to achieve an adequate vacuum. Addition of a fluid trap does not affect the vacuum, and head gauges supplied with vacuum pumps are accurate.

  7. Vacuum-assisted delivery

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000514.htm Vacuum-assisted delivery To use the sharing features on ... the baby through the birth canal. When is Vacuum-assisted Delivery Needed? Even after your cervix is ...

  8. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-03-06

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  9. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  10. The Classical Vacuum.

    ERIC Educational Resources Information Center

    Boyer, Timothy H.

    1985-01-01

    The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

  11. The Classical Vacuum.

    ERIC Educational Resources Information Center

    Boyer, Timothy H.

    1985-01-01

    The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

  12. Nanoscale Vacuum Channel Transistor.

    PubMed

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M

    2017-04-12

    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (<5 V) and provides a high drive current (>3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  13. Troubleshooting crude vacuum tower overhead ejector systems

    SciTech Connect

    Lines, J.R.; Frens, L.L. )

    1995-03-01

    Routinely surveying tower overhead vacuum systems can improve performance and product quality. These vacuum systems normally provide reliable and consistent operation. However, process conditions, supplied utilities, corrosion, erosion and fouling all have an impact on ejector system performance. Refinery vacuum distillation towers use ejector systems to maintain tower top pressure and remove overhead gases. However, as with virtually all refinery equipment, performance may be affected by a number of variables. These variables may act independently or concurrently. It is important to understand basic operating principles of vacuum systems and how performance is affected by: utilities, corrosion and erosion, fouling, and process conditions. Reputable vacuum-system suppliers have service engineers that will come to a refinery to survey the system and troubleshoot performance or offer suggestions for improvement. A skilled vacuum-system engineer may be needed to diagnose and remedy system problems. The affect of these variables on performance is discussed. A case history is described of a vacuum system on a crude tower in a South American refinery.

  14. Indian Vacuum Society: The Indian Vacuum Society

    NASA Astrophysics Data System (ADS)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  15. Gravitational vacuum polarization. II. Energy conditions in the Boulware vacuum

    SciTech Connect

    Visser, M.

    1996-10-01

    Building on techniques developed in the preceding paper, I investigate the various pointwise and averaged energy conditions for the quantum stress-energy tensor corresponding to a conformally coupled massless scalar field in the Boulware vacuum. I work in the test-field limit, restrict attention to the Schwarzschild geometry, and invoke a mixture of analytical and numerical techniques. In contradistinction to the case of the Hartle-Hawking vacuum, wherein violations of the energy conditions were confined to the region between the event horizon and the unstable photon orbit, I show that in the Boulware vacuum (1) all standard (pointwise and averaged) energy conditions are violated throughout the exterior region, all the way from spatial infinity down to the event horizon, and (2) outside the event horizon the standard pointwise energy conditions are violated in a maximal manner: They are violated at all points and for all null or timelike vectors. (The region inside the event horizon is considerably messier and of dubious physical relevance. Nevertheless, the standard pointwise energy conditions seem to be violated even inside the event horizon.) I argue that this is highly suggestive evidence, pointing to the fact that general self-consistent solutions of semiclassical quantum gravity might {ital not} satisfy the energy conditions and may in fact for certain quantum fields and certain quantum states violate {ital all} the energy conditions. {copyright} {ital 1996 The American Physical Society.}

  16. Vacuum pump aids ejectors

    SciTech Connect

    Nelson, R.E.

    1982-12-01

    The steam ejector/vacuum pump hybrid system has been operating satisfactorily since the summer of 1981. This system has essentially been as troublefree as the all-ejector system and, of course, has provided a substantial cost savings. Construction is currently under way to convert the vacuum system of another crude still which is equipped with steam ejectors and barometric condensers to the hybrid system of steam ejectors, surface condensers, and vacuum pumps. This current project is even more financially attractive because it allows a dirty water cooling tower which serves the barometric condensers to be shut down. Providing a vacuum for crude distillation vacuum towers with this hybrid system is by no means the only application of this technique. Any vacuum system consisting of all steam ejectors would be a candidate for this hybrid system and the resulting savings in energy.

  17. Maintaining vacuum furnaces

    SciTech Connect

    Kowalewski, J.

    2000-04-01

    A preventive maintenance program is essential for safe and consistent vacuum furnace operation. The program should be developed in cooperation with safety, maintenance, and furnace operators, implemented as soon as the furnace is commissioned, and adhered to throughout the life of the furnace. This article serves as an introduction to the topic of vacuum furnace preventive maintenance. Basic information about installing a new vacuum furnace also is provided.

  18. Immunologic aspects of chronic fatigue syndrome. Report on a Research Symposium convened by The CFIDS Association of America and co-sponsored by the US Centers for Disease Control and Prevention and the National Institutes of Health.

    PubMed

    Gerrity, Timothy R; Papanicolaou, Dimitris A; Amsterdam, Jay D; Bingham, Stephen; Grossman, Ashley; Hedrick, Terry; Herberman, Ronald B; Krueger, Gerhard; Levine, Susan; Mohagheghpour, Nahid; Moore, Rebecca C; Oleske, James; Snell, Christopher R

    2004-01-01

    Chronic fatigue syndrome (CFS) is a serious health concern affecting over 800,000 Americans of all ages, races, socioeconomic groups and genders. The etiology and pathophysiology of CFS are unknown, yet studies have suggested an involvement of the immune system. A symposium was organized in October 2001 to explore the possibility of an association between immune dysfunction and CFS, with special emphasis on the interactions between immune dysfunction and other abnormalities noted in the neuroendocrine and autonomic nervous systems of individuals with CFS. This paper represents the consensus of the panel of experts who participated in this meeting. Data suggest that persons with CFS manifest changes in immune responses that fall outside normative ranges, but current research does not provide definitive evidence on whether these immune abnormalities are a cause or result of the illness. It has become clear that CFS cannot be understood based on single measurements of immune, endocrine, cardiovascular, or autonomic nervous system dysfunction. This panel encourages a new emphasis on multidisciplinary research into CFS.

  19. Vacuum probe surface sampler

    NASA Technical Reports Server (NTRS)

    Zahlava, B. A. (Inventor)

    1973-01-01

    A vacuum probe surface sampler is described for rapidly sampling relatively large surface areas which possess relatively light loading densities of micro-organism, drug particles or the like. A vacuum head with a hollow handle connected to a suitable vacuum source is frictionally attached to a cone assembly terminating in a flared tip adapted to be passed over the surface to be sampled. A fine mesh screen carried by the vacuum head provides support for a membrane filter which collects the microorganisms or other particles. The head assembly is easily removed from the cone assembly without contacting the cone assembly with human hands.

  20. Gravitation and vacuum field

    SciTech Connect

    Tevikyan, R.V.

    1986-03-01

    This paper presents equations that describe particles with spins s = 0, 1/2, 1 completely and which also describe 2s + 2 limiting fields as E ..-->.. infinity. It is shown that the ordinary Hilbert-Einstein action for the gravitation field must be augmented by the action for the Bose vacuum field. This means that one must introduce in the gravitational equations a cosmological term proportional to the square of the strength of the Bose vacuum field. It is shown that the theory of gravitation describes three realities: matter, field, and vacuum field. A new form of matter--the vacuum field--is introduced into field theory.

  1. American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer.

    PubMed

    Saslow, Debbie; Solomon, Diane; Lawson, Herschel W; Killackey, Maureen; Kulasingam, Shalini L; Cain, Joanna M; Garcia, Francisco A R; Moriarty, Ann T; Waxman, Alan G; Wilbur, David C; Wentzensen, Nicolas; Downs, Levi S; Spitzer, Mark; Moscicki, Anna-Barbara; Franco, Eduardo L; Stoler, Mark H; Schiffman, Mark; Castle, Philip E; Myers, Evan R; Chelmow, David; Herzig, Abbe; Kim, Jane J; Kinney, Walter; Herschel, W Lawson; Waldman, Jeffrey

    2012-07-01

    An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from six working groups, and a recent symposium co-sponsored by the ACS, American Society for Colposcopy and Cervical Pathology (ASCCP), and American Society for Clinical Pathology (ASCP), which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (e.g., management of screen positives and screening interval for screen negatives) of women after screening, age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16/18 infections.

  2. American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology Screening Guidelines for the Prevention and Early Detection of Cervical Cancer

    PubMed Central

    Saslow, Debbie; Solomon, Diane; Lawson, Herschel W.; Killackey, Maureen; Kulasingam, Shalini; Cain, Joanna; Garcia, Francisco A. R.; Moriarty, Ann; Waxman, Alan; Wilbur, David; Wentzensen, Nicolas; Downs, Levi; Spitzer, Mark; Moscicki, Anna-Barbara; Saraiya, Mona; Franco, Eduardo L.; Stoler, Mark H.; Schiffman, Mark; Castle, Philip E.; Myers, Evan R.

    2013-01-01

    An update to the American Cancer Society (ACS) guideline regarding screening for the early detection of cervical precancerous lesions and cancer is presented. The guidelines are based on a systematic evidence review, contributions from six working groups, and a recent symposium co-sponsored by the ACS, American Society for Colposcopy and Cervical Pathology (ASCCP), and American Society for Clinical Pathology (ASCP), which was attended by 25 organizations. The new screening recommendations address age-appropriate screening strategies, including the use of cytology and high-risk human papillomavirus (HPV) testing, follow-up (e.g., management of screen positives and screening interval for screen negatives) of women after screening, age at which to exit screening, future considerations regarding HPV testing alone as a primary screening approach, and screening strategies for women vaccinated against HPV16 and HPV18 infections. PMID:22418039

  3. Working in a Vacuum

    ERIC Educational Resources Information Center

    Rathey, Allen

    2005-01-01

    In this article, the author discusses several myths about vacuum cleaners and offers tips on evaluating and purchasing this essential maintenance tool. These myths are: (1) Amps mean performance; (2) Everyone needs high-efficiency particulate air (HEPA): (3) Picking up a "bowling ball" shows cleaning power; (4) All vacuum bags are the same; (5)…

  4. Working in a Vacuum

    ERIC Educational Resources Information Center

    Rathey, Allen

    2005-01-01

    In this article, the author discusses several myths about vacuum cleaners and offers tips on evaluating and purchasing this essential maintenance tool. These myths are: (1) Amps mean performance; (2) Everyone needs high-efficiency particulate air (HEPA): (3) Picking up a "bowling ball" shows cleaning power; (4) All vacuum bags are the same; (5)…

  5. Microfabricated triggered vacuum switch

    DOEpatents

    Roesler, Alexander W.; Schare, Joshua M.; Bunch, Kyle

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  6. ELETTRA vacuum system

    NASA Astrophysics Data System (ADS)

    Bernardini, M.

    1991-08-01

    A status report of the vacuum system of ELETTRA, the 2 GeV, 400 mA light source under construction in Trieste, will be described. The Vacuum project, presented at ``Synchrotron Radiation Vacuum Workshop'' at Riken (Japan 22-24 March 1990) and more recently at EVC-2, the European Vacuum Conference at Trieste (Italy 21-26 May 1990), is now in the phase of testing a prototype sector, which is 1/24 of the ring circumference. Details and some technological aspects of the fabrication will be reviewed together with the vacuum performances. Results of laboratory experiments on components, standard or not, allowed us to finalize the main choices in light of the general philosophy of the project and will be properly summarized.

  7. Cervical spine annulus vacuum.

    PubMed

    Bohrer, S P; Chen, Y M

    1988-01-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  8. Vacuum tunneling in gravity

    NASA Astrophysics Data System (ADS)

    Cho, Y. M.; Pak, D. G.

    2011-08-01

    Topologically non-trivial vacuum structures in gravity models with Cartan variables (vielbein and contortion) are considered. We study the possibility of vacuum spacetime tunneling in Einstein gravity assuming that the vielbein may play a fundamental role in quantum gravitational phenomena. It has been shown that in the case of RP3 space topology, the tunneling between non-trivial topological vacuums can be realized by means of Eguchi-Hanson gravitational instanton. In the Riemann-Cartan geometric approach to quantum gravity, the vacuum tunneling can be provided by means of contortion quantum fluctuations. We define a double self-duality condition for the contortion and give explicit self-dual configurations which can contribute to vacuum tunneling amplitude.

  9. Housing protects laser in vacuum

    NASA Technical Reports Server (NTRS)

    Canali, V. G.

    1978-01-01

    Airtight housing encloses laser for easy alinement and operation in high-vacuum chamber. Beam is transmitted through window into vacuum chamber. Flexible line runs through vacuum chamber to outside, maintaining laser enclosure at atmospheric pressure.

  10. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2001-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  11. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2000-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  12. Gravitational vacuum polarization. IV. Energy conditions in the Unruh vacuum

    SciTech Connect

    Visser, M.

    1997-07-01

    Building on a series of earlier papers, I investigate the various pointwise and averaged energy conditions in the Unruh vacuum. I consider the quantum stress-energy tensor corresponding to a conformally coupled massless scalar field, work in the test-field limit, restrict attention to the Schwarzschild geometry, and invoke a mixture of analytical and numerical techniques. I construct a semianalytic model for the stress-energy tensor that globally reproduces all known numerical results to within 0.8{percent}, and satisfies all known analytic features of the stress-energy tensor. I show that in the Unruh vacuum (1) all standard pointwise energy conditions are violated throughout the exterior region, all the way from spatial infinity down to the event horizon, and (2) the averaged null energy condition is violated on all outgoing radial null geodesics. In a pair of appendices I indicate a general strategy for constructing semianalytic models for the stress-energy tensor in the Hartle-Hawking and Boulware states, and show that the Page approximation is in a certain sense the minimal {ital Ansatz} compatible with general properties of the stress energy in the Hartle-Hawking state. {copyright} {ital 1997} {ital The American Physical Society}

  13. Collapse of vacuum bubbles in a vacuum

    NASA Astrophysics Data System (ADS)

    Ng, Kin-Wang; Wang, Shang-Yung

    2011-02-01

    We revisit the dynamics of a false vacuum bubble in a background de Sitter spacetime. We find that there exists a large parameter space that allows the bubble to collapse into a black hole or to form a wormhole. This may have interesting implications for the creation of a baby universe in the laboratory, the string landscape where the bubble nucleation takes place among a plenitude of metastable vacua, and the inflationary physics.

  14. Collapse of vacuum bubbles in a vacuum

    SciTech Connect

    Ng, Kin-Wang; Wang, Shang-Yung

    2011-02-15

    We revisit the dynamics of a false vacuum bubble in a background de Sitter spacetime. We find that there exists a large parameter space that allows the bubble to collapse into a black hole or to form a wormhole. This may have interesting implications for the creation of a baby universe in the laboratory, the string landscape where the bubble nucleation takes place among a plenitude of metastable vacua, and the inflationary physics.

  15. Vacuum mechatronics first international workshop

    SciTech Connect

    Belinski, S.E.; Shirazi, M.; Hackwood, S.; Beni, G. )

    1989-01-01

    This report contains papers on the following topics: proposed epitaxial thin film growth in the ultra-vacuum of space; particle monitoring and control in vacuum processing equipment; electrostatic dust collector for use in vacuum systems; materials evaluation of an electrically noisy vacuum slip ring assembly; an overview of lubrication and associated materials for vacuum service; the usage of lubricants in a vacuum environment; guidelines and practical applications for lubrication in vacuum; recent development in leak detector and calibrator designs; the durability of ballscrews for ultrahigh vacuum; vacuum-compatible robot for self-contained manufacturing systems; the design, fabrication, and assembly of an advanced vacuum robotics system for space payload calibration; design criteria for mechanisms used in space; and concepts and requirements for semiconductor multiprocess integration in vacuum. These papers are indexed separately elsewhere.

  16. The classical vacuum

    NASA Astrophysics Data System (ADS)

    Boyer, T. H.

    1985-08-01

    The history of vacuum concepts is reviewed, noting that no way is known to physically produce a true void. Even at absolute zero, a pattern of electromagnetic wave fluctuations are still present. The fluctuations are called zero-point radiation (ZPR). To be invariant to Lorentz transformation, ZPR has a spectral intensity proportional to the cube of each frequency. ZPR does not change in response to compression and produces a force between objects that is inversely proportional to the 4th power of the separation distance. The ZPR scale value has been measured to be one-half of the Planck constant, and is the measure of the energy of a harmonic oscillator, such as the electron, in a vacuum. Finally, since gravitational accelerations always occur in the physical space, a minimum thermal radiation can also be found for the vacuum, implying that a fixed relationship exists between thermal radiation and the classical vacuum.

  17. Vacuum Camera Cooler

    NASA Technical Reports Server (NTRS)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  18. Welding space vacuum technology

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1991-01-01

    The objective was to assist the EH 42 Division in putting together a vacuum system that could attain the desired pressure and be large enough to accommodate the gas-metal arc (GMA) welding fixture apparatus. A major accomplishment was the design and fabrication of the controller/annunciator for the 4' by 8' system. It contains many safety features such as thermocouple set point relays that will only allow inlet and exit gas and vacuum valves to be operated at pre-selected system pressures, and a fail safe mode for power interruptions and operator mistakes. It is felt that significant progress was made in this research effort to weld in a vacuum environment. With continued efforts to increase the pump speeds for vacuum chambers and further studies on weld fixtures and gas inlet pressures, the NASA program will be successful.

  19. TFTR diagnostic vacuum controller

    SciTech Connect

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller.

  20. Vacuum self-magnetization?

    SciTech Connect

    Perez Rojas, H.; Rodriguez Querts, E.

    2006-06-19

    We study vacuum properties in a strong magnetic field as the zero temperature and zero density limit of quantum statistics. For charged vector bosons (W bosons) the vacuum energy density diverges for B > B{sub c} = m{sub w}{sup 2}/e, leading to vacuum instability. A logarithmic divergence of vacuum magnetization is found for B = Bc, which suggests that if the magnetic field is large enough, it is self-consistently maintained, and this mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the instability of the ground state for B > B{sub c}{sup '} = m{sub n}{sup 2}/q also leads to the vacuum energy density divergence for fields B > B{sub c}{sup '} and to the magnetization divergence for B B{sub c}{sup '}. The possibility of virtual electron-positron pairs bosonization in strong magnetic field and the applicability of the neutral bosons model to describe the virtual positronium behavior in a magnetic field are discussed. We conjecture that this could lead to vacuum self-magnetization in QED.

  1. Gravitational vacuum polarization. I. Energy conditions in the Hartle-Hawking vacuum

    SciTech Connect

    Visser, M.

    1996-10-01

    When a quantum field theory is constructed on a curved background spacetime, the gravitationally induced vacuum polarization typically induces a nonzero vacuum expectation value for the quantum stress-energy tensor. It is well known that this gravitational vacuum polarization often violates the pointwise energy conditions and sometimes violates the averaged energy conditions. In this paper I begin a systematic attack on the question of where and by how much the various energy conditions are violated. To keep the discussion manageable, I work in the test-field limit, and focus on conformally coupled massless scalar fields in Schwarzschild spacetime, using the Hartle-Hawking vacuum. The discussion invokes a mixture of analytical and numerical techniques, and critically compares the qualitative behavior to be expected from the Page approximation with that adduced from the numerical calculations of Anderson, Hiscock, and Samuel. I show that the various pointwise energy conditions are violated in a series of onionlike layers located between the unstable photon orbit and the event horizon, the sequence of violations being DEC, WEC, and (NEC+SEC). Furthermore, the ANEC is violated for {ital some} of the null geodesics trapped in this region. Having established the basic machinery in this paper, the Boulware vacuum will be treated in a companion paper, while studies of the Unruh vacuum should be straightforward, as should extensions to nonconformal couplings, massive scalars, and Reissner-Nordstr{umlt o}m geometries. {copyright} {ital 1996 The American Physical Society.}

  2. ISABELLE vacuum systems

    SciTech Connect

    Halama, H J

    1980-01-01

    The Intersecting Storage Accelerator (ISABELLE) consists of two rings having a circumference of 3.8 km each. In these rings superconducting magnets, held at 4 K, bend and focus the proton beam which is accelerated up to 400 GeV. Due to very different pressure requirements, ISABELLE has two completely independent vacuum systems. One, which operates at 1 x 10/sup -11/ Torr, provides a very clean environment for the circulating proton beam. Here only ion and titanium sublimation pumps are used to provide the vacuum. The other system maintains superconducting magnet vessels at a pressure below 1 x 10/sup -4/ Torr, since at this pressure the gas conduction becomes negligible. In this so-called insulating vacuum system, turbomolecular pumps pump the inadvertent small helium leaks. Other gases are cryocondensed on the cold surfaces of the cryogenic system. The basic element of ISABELLE known as Full Cell containing 45 meters of beam tube, 8 pumping stations, 8 superconducting magnets and complete instrumentation has been constructed, leak checked and tested. All design parameters have been achieved in both vacuum systems. The two vacuum systems are described with particular emphasis on the influence of superconducting magnets in the selection of materials and UHV components.

  3. Improving Vacuum Cleaners

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  4. K-130 Cyclotron vacuum system

    NASA Astrophysics Data System (ADS)

    Yadav, R. C.; Bhattacharya, S.; Bhole, R. B.; Roy, Anindya; Pal, Sarbajit; Mallik, C.; Bhandari, R. K.

    2012-11-01

    The vacuum system for K-130 cyclotron has been operational since 1977. It consists of two sub-systems, main vacuum system and beam line vacuum system. The main vacuum system is designed to achieve and maintain vacuum of about 1 × 10-6 mbar inside the 23 m3 volume of acceleration chamber comprising the Resonator tank and the Dee tank. The beam line vacuum system is required for transporting the extracted beam with minimum loss. These vacuum systems consist of diffusion pumps backed by mechanical pumps like roots and rotary pumps. The large vacuum pumps and valves of the cyclotron vacuum system were operational for more than twenty five years. In recent times, problems of frequent failures and maintenance were occurring due to aging and lack of appropriate spares. Hence, modernisation of the vacuum systems was taken up in order to ensure a stable high voltage for radio frequency system and the extraction system. This is required for efficient acceleration and transportation of high intensity ion beam. The vacuum systems have been upgraded by replacing several pumps, valves, gauges and freon units. The relay based control system for main vacuum system has also been replaced by PLC based state of the art control system. The upgraded control system enables inclusion of additional operational logics and safety interlocks into the system. The paper presents the details of the vacuum system and describes the modifications carried out for improving the performance and reliability of the vacuum system.

  5. Superoleophobicity under vacuum

    NASA Astrophysics Data System (ADS)

    Liu, Xinjie; Wang, Xiaolong; Liang, Yongmin; Bell, Steven E. J.; Liu, Weimin; Zhou, Feng

    2011-05-01

    By using superoleophobic alumina and low vapor pressure oils we have been able to study wetting behavior at high vacuum. Here, we show that a superoleophobic state can exist for some probe liquids, even under high vacuum. However, with other liquids the surfaces are only superoloephobic because air is trapped beneath the droplet and the contact angle decreases dramatically (150°-120°) if this air is removed. These observations open up the possibility of designing materials which fully exploit the potential of physically trapped air to achieve extreme oleophobicity and/or hydrophobicity.

  6. Electrostatic Levitator Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (beam passes through the window at left), positioning lasers (one port is at center), and lamps to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  7. VACUUM SEALING MEANS FOR LOW VACUUM PRESSURES

    DOEpatents

    Milleron, N.

    1962-06-12

    S>A vacuum seal is designed in which the surface tension of a thin layer of liquid metal of low vapor pressure cooperates with adjacent surfaces to preclude passages of gases across pressure differentials as low as 10/sup -8/ mm Hg. Mating contiguous surfaces composed of copper, brass, stainless steel, nickel, molybdenum, tungsten, tantalum, glass, quartz, and/or synthetic mica are disposed to provide a maximum tolerance, D, expressed by 2 gamma /P/sub 1/, where gamma is the coefflcient of the surface tension of the metal sealant selected in dynes/cm/sub 2/. Means for heating the surfaces remotely is provided where temperatures drop below about 250 deg C. A sealant consisting of an alloy of gallium, indium, and tin, among other combinations tabulated, is disposed therebetween after treating the surfaces to improve wettability, as by ultrasonic vibrations, the surfaces and sealants being selected according to the anticipated experimental conditions of use. (AEC)

  8. Vacuum Kundt waves

    NASA Astrophysics Data System (ADS)

    McNutt, David; Milson, Robert; Coley, Alan

    2013-03-01

    We discuss the invariant classification of vacuum Kundt waves using the Cartan-Karlhede algorithm and determine the upper bound on the number of iterations of the Karlhede algorithm to classify the vacuum Kundt waves (Collins (1991 Class. Quantum Grav. 8 1859-69), Machado Ramos (1996 Class. Quantum Grav. 13 1589)). By choosing a particular coordinate system we partially construct the canonical coframe used in the classification to study the functional dependence of the invariants arising at each iteration of the algorithm. We provide a new upper bound, q ⩽ 4, and show that this bound is sharp by analyzing the subclass of Kundt waves with invariant count beginning with (0, 1,…) to show that the class with invariant count (0, 1, 3, 4, 4) exists. This class of vacuum Kundt waves is shown to be unique as the only set of metrics requiring the fourth covariant derivatives of the curvature. We conclude with an invariant classification of the vacuum Kundt waves using a suite of invariants.

  9. Sorption vacuum trap

    NASA Technical Reports Server (NTRS)

    Barrington, A. E.; Caruso, A. J.

    1970-01-01

    Modified sorption trap for use in high vacuum systems contains provisions for online regeneration of sorbent material. Trap is so constructed that it has a number of encapsulated resistance heaters and a valving and pumping device for removing gases from heated sorbing material. Excessive downtime is eliminated with this trap.

  10. Various unique vacuum holders

    SciTech Connect

    Gregar, J.S.

    1992-12-01

    Glassblowers use vacuum holding devices to support a flat plate in the glassflowing lathe to seal onto the end of, or inside of, a glass cylinder. Glassblowing blowhose swivels tend to leak; a rotating union from the hydraulics industry is better. Various graphite holder designs are described.

  11. Vacuum ultraviolet holography

    NASA Technical Reports Server (NTRS)

    Bjorklund, G. C.; Harris, S. E.; Young, J. F.

    1974-01-01

    The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded.

  12. Gas injected vacuum switch

    DOEpatents

    Hardin, K. Dan

    1977-01-01

    The disclosure relates to a gas injected vacuum switch comprising a housing having an interior chamber, a conduit for evacuating the interior chamber, within the chamber an anode and a cathode spaced from the anode, and a detonator for injecting electrically conductive gas into the chamber between the anode and the cathode to provide a current path therebetween.

  13. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  14. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  15. Furnace brazing under partial vacuum

    NASA Technical Reports Server (NTRS)

    Mckown, R. D.

    1979-01-01

    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  16. Gas bearing operates in vacuum

    NASA Technical Reports Server (NTRS)

    Perkins, G. S.

    1975-01-01

    Bearing has restrictions to reduce air leaks and is connected to external pumpout facility which removes exhausted air. Token amount of air which is lost to vacuum is easily removed by conventional vacuum pump.

  17. Tritium handling in vacuum systems

    SciTech Connect

    Gill, J.T.; Coffin, D.O.

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  18. Furnace brazing under partial vacuum

    NASA Technical Reports Server (NTRS)

    Mckown, R. D.

    1979-01-01

    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  19. A radiation hard vacuum switch

    DOEpatents

    Boettcher, G.E.

    1988-07-19

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction. 3 figs.

  20. Bakeout Chamber Within Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Taylor, Daniel M.; Soules, David M.; Barengoltz, Jack B.

    1995-01-01

    Vacuum-bakeout apparatus for decontaminating and measuring outgassing from pieces of equipment constructed by mounting bakeout chamber within conventional vacuum chamber. Upgrade cost effective: fabrication and installation of bakeout chamber simple, installation performed quickly and without major changes in older vacuum chamber, and provides quantitative data on outgassing from pieces of equipment placed in bakeout chamber.

  1. Surge-damping vacuum valve

    DOEpatents

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  2. Portable vacuum object handling device

    DOEpatents

    Anderson, Gordon H.

    1983-08-09

    The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object.

  3. Bakeout Chamber Within Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Taylor, Daniel M.; Soules, David M.; Barengoltz, Jack B.

    1995-01-01

    Vacuum-bakeout apparatus for decontaminating and measuring outgassing from pieces of equipment constructed by mounting bakeout chamber within conventional vacuum chamber. Upgrade cost effective: fabrication and installation of bakeout chamber simple, installation performed quickly and without major changes in older vacuum chamber, and provides quantitative data on outgassing from pieces of equipment placed in bakeout chamber.

  4. Mercury vacuum cleaner operational test and evaluation

    SciTech Connect

    Bennett, R.G.

    1981-03-01

    The Dental Investigation Service, USAFSAM, Brooks AFB, has outlined the need for a vacuum unit to be used in the Air Force dental clinics. The unit must be capable of effectively picking up mercury and at the same time not redistribute mercury vapors throughout the dental clinic during normal operations or mercury-spill situations. The Dental Investigation Service selected the MRS-3, Minuteman Mercury Recovery System, product of American Cleaning Equipment Corporation as the mercury vacuum to be used for T E. The USAF OEHL/ECH was requested by the Dental Investigation Service to perform the T E on the MRS-3 for possible health hazards due to exposures of mercury vapors.

  5. Vacuum tool manipulator

    DOEpatents

    Zollinger, William T.

    1993-01-01

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

  6. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  7. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  8. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  9. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  10. Integrated structure vacuum tube

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Kerwin, W. J. (Inventor)

    1976-01-01

    High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

  11. Electrostatic Levitator Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), poisitioning lasers (one port is at center), and lamps (such as the deuterium arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  12. Edison's vacuum technology patents

    NASA Astrophysics Data System (ADS)

    Waits, Robert K.

    2003-07-01

    During 1879 Thomas Edison's Menlo Park, New Jersey laboratory developed the means to evacuate glass lamp globes to less than a mTorr in 20 min and in mid-1880 began production of carbon-filament incandescent lamps. Among Edison's nearly 1100 U.S. patents are five for vacuum pump improvements, and at least eight others that are vacuum-related; all applied for between 1880 and 1886. Inspired by an 1878 article by De La Rue and Müller [Philos. Trans. R. Soc. London, Ser. A 169, 155 (1878)] on studies of glow discharges, Edison devised a combination pump using the Geissler pump as a rough pump and the Sprengel pump for continuous exhaustion. Edison's patents described means to control the mercury flow and automate the delivery of the mercury to banks of up to a hundred pumps. Other patents described various means to remove residual gases during lamp processing.

  13. Vacuum tool manipulator

    SciTech Connect

    Zollinger, W.T.

    1992-12-31

    This invention is comprised of an apparatus for manipulating a vacuum hose in a reactor vessel comprising a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

  14. Vacuum tool manipulator

    DOEpatents

    Zollinger, W.T.

    1993-11-23

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm. 6 figures.

  15. An automated vacuum system

    SciTech Connect

    Atkins, W.H. ); Vaughn, G.D. ); Bridgman, C. )

    1991-01-01

    Software tools available with the Ground Test Accelerator (GTA) control system provide the capability to express a control problem as a finite state machine. System states and transitions are expressed in terms of accelerator parameters and actions are taken based on state transitions. This is particularly useful for sequencing operations which are modal in nature or are unwieldy when implemented with conventional programming. State diagrams are automatically translated into code which is executed by the control system. These tools have been applied to the vacuum system for the GTA accelerator to implement automatic sequencing of operations. With a single request, the operator may initiate a complete pump-down sequence. He can monitor the progress and is notified if an anomaly occurs requiring intervention. The operator is not required to have detailed knowledge of the vacuum system and is protected from taking inappropriate actions. 1 ref., 6 figs.

  16. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  17. Vacuum in a strong magnetic field as a hyperbolic metamaterial.

    PubMed

    Smolyaninov, Igor I

    2011-12-16

    As demonstrated by Chernodub, vacuum in a strong magnetic field behaves as Abrikosov vortex lattice in a type-II superconductor. We investigate electromagnetic behavior of vacuum in this state and demonstrate that vacuum behaves as a hyperbolic metamaterial. If the magnetic field is constant, low frequency extraordinary photons experience this medium as a (3+1) Minkowski spacetime in which the role of time is played by the spatial z coordinate. Variations of the magnetic field curve this spacetime, and may lead to formation of "electromagnetic black holes." Since hyperbolic metamaterials behave as diffractionless "perfect lenses," and large enough magnetic fields probably existed in the early Universe, the demonstrated hyperbolic behavior of early vacuum may have imprints in the large scale structure of the present-day Universe. © 2011 American Physical Society

  18. Application of porcelain enamel as an ultra-high-vacuum-compatible electrical insulator

    SciTech Connect

    Biscardi, C.; Hseuh, H.; Mapes, M.

    2000-07-01

    Many accelerator vacuum system components require electrical insulation internal to the vacuum system. Some accelerator components at Brookhaven National Laboratory are installed in ultra-high-vacuum systems which require the insulation to have excellent vacuum characteristics, be radiation resistant, and be able to withstand high temperatures when used on baked systems. Porcelain enamel satisfies all these requirements. This article describes the process and application of coating metal parts with porcelain enamel to provide electrical insulation. The mechanical and vacuum testing of Marman flanges coated with porcelain and using metal Helicoflex seals to form a zero-length electrical break are detailed. The use of porcelain enameled parts is attractive since it can be done quickly, is inexpensive and environmentally safe, and most of all satisfies stringent vacuum system requirements. (c) 2000 American Vacuum Society.

  19. Vacuum bell therapy

    PubMed Central

    Sesia, Sergio

    2016-01-01

    Background For specific therapy to correct pectus excavatum (PE), conservative treatment with the vacuum bell (VB) was introduced more than 10 years ago in addition to surgical repair. Preliminary results using the VB were encouraging. We report on our 13-year experience with the VB treatment including the intraoperative use during the Nuss procedure and present some technical innovations. Methods A VB with a patient-activated hand pump is used to create a vacuum at the anterior chest wall. Three different sizes of vacuum bells, as well as a model fitted for young women, exist. The appropriate size is selected according to the individual patient’s age and ventral surface. The device should be used at home for a minimum of 30 minutes (twice a day), and may be used up to a maximum of several hours daily. The intensity of the applied negative pressure can be evaluated with an integrated pressure gauge during follow-up visits. A prototype of an electronic model enables us to measure the correlation between the applied negative pressure and the elevation of the anterior chest wall. Results Since 2003, approx. 450 patients between 2 to 61 years of age started the VB therapy. Age and gender specific differences, depth of PE, symmetry or asymmetry, and concomitant malformations such as scoliosis and/or kyphosis influence the clinical course and success of VB therapy. According to our experience, we see three different groups of patients. Immediate elevation of the sternum was confirmed thoracoscopically during the Nuss procedure in every patient. Conclusions The VB therapy has been established as an alternative therapeutic option in selected patients suffering from PE. The initial results up to now are encouraging, but long-term results comprising more than 15 years are so far lacking, and further evaluation and follow-up studies are necessary. PMID:27747177

  20. Polymers in a Vacuum

    SciTech Connect

    Deutsch, J. M.

    2007-12-07

    In a variety of situations, isolated polymer molecules are found in a vacuum, and here we examine their properties. Angular momentum conservation is shown to significantly alter the average size of a chain and its conservation is only broken slowly by thermal radiation. For an ideal chain, the time autocorrelation for monomer position oscillates with a period proportional to chain length. The oscillations and damping are analyzed in detail. Short-range repulsive interactions suppress oscillations and speed up relaxation, but stretched chains still show damped oscillatory correlations.

  1. Rolling through a vacuum

    NASA Astrophysics Data System (ADS)

    van der Schaar, Jan Pieter; Yang, I.-Sheng

    2013-12-01

    We clarify under what conditions slow-roll inflation can continue almost undisturbed, while briefly evolving through a (semi-classically) metastable false vacuum. Furthermore, we look at potential signatures in the primordial power spectrum that could point towards the existence of traversed metastable false vacua. Interestingly, the theoretical constraints for the existence of traversable metastable vacua imply that Planck should be able to detect the resulting features in the primordial power spectrum. In other words, if Planck does not see features this immediately implies the non-existence of metastable false vacua rolled through during the inflationary epoch.

  2. Avoiding Death by Vacuum

    NASA Astrophysics Data System (ADS)

    Barroso, A.; Ferreira, P. M.; Ivanov, I.; Santos, R.; Silva, João P.

    2013-07-01

    The two-Higgs doublet model (2HDM) can have two electroweak breaking, CP-conserving, minima. The possibility arises that the minimum which corresponds to the known elementary particle spectrum is metastable, a possibility we call the "panic vacuum". We present analytical bounds on the parameters of the softly broken Peccei-Quinn 2HDM which are necessary and sufficient conditions to avoid this possibility. We also show that, for this particular model, the current LHC data already tell us that we are necessarily in the global minimum of the theory, regardless of any cosmological considerations about the lifetime of the false vacua.

  3. Vacuum Beat Wave Accelerator

    NASA Astrophysics Data System (ADS)

    Moore, C. I.; Hafizi, B.; Ting, A.; Burris, H. R.; Sprangle, P.; Esarey, E.; Ganguly, A.; Hirshfield, J. L.

    1997-11-01

    The Vacuum Beat Wave Accelerator (VBWA) is a particle acceleration scheme which uses the non-linear ponderomotive beating of two different frequency laser beams to accelerate electrons. A proof-of-principle experiment to demonstrate the VBWA is underway at the Naval Research Laboratory (NRL). This experiment will use the beating of a 1054 nm and 527 nm laser pulse from the NRL T-cubed laser to generate the beat wave and a 4.5 MeV RF electron gun as the electron source. Simulation results and the experimental design will be presented. The suitability of using axicon or higher order Gaussian laser beams will also be discussed.

  4. Plasmons in QED vacuum

    NASA Astrophysics Data System (ADS)

    Petrov, E. Yu.; Kudrin, A. V.

    2016-09-01

    The problem of longitudinal oscillations of an electric field and a charge polarization density in a quantum electrodynamics (QED) vacuum is considered. Within the framework of semiclassical analysis, we calculate time-periodic solutions of bosonized (1 +1 )-dimensional QED (massive Schwinger model). Applying the Bohr-Sommerfeld quantization condition, we determine the mass spectrum of charge-zero bound states (plasmons) which correspond in quantum theory to the found classical solutions. We show that the existence of such plasmons does not contradict any fundamental physical laws and study qualitatively their excitation in a (3 +1 )-dimensional real world.

  5. Thermal Vacuum Test Facility.

    DTIC Science & Technology

    1984-01-31

    tne power has a rear terminal sensor input for this Probe, use it. Otherwiseq connect the probe to the front panel. The end of the sensor should be...outlet on the front panel of the vacuum chamber. BUS CONNECTtONS: Plug the 1/0 expander card into one of the three calculator slots. Cover the other two...mating cable. Soth connectors on the slave disk are identical, so either one can be used. This cable also locks into place at each end . Connect the other

  6. R&D ERL: Vacuum

    SciTech Connect

    Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

    2010-01-01

    The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The

  7. Portable vacuum object handling device

    DOEpatents

    Anderson, G.H.

    1983-08-09

    The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object. 1 fig.

  8. Vacuum vapor deposition

    NASA Technical Reports Server (NTRS)

    Poorman, Richard M. (Inventor); Weeks, Jack L. (Inventor)

    1995-01-01

    A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate.

  9. MOLECULAR VACUUM PUMP

    DOEpatents

    Eckberg, E.E.

    1960-09-27

    A multiple molecular vacuum pump capable of producing a vacuum of the order of 10/sup -9/ mm Hg is described. The pump comprises a casing of an aggregate of paired and matched cylindrical plates, a recessed portion on one face of each plate concentrically positioned formed by a radially extending wall and matching the similarly recessed portion of its twin plate of that pair of plates and for all paired and matched plates; a plurality of grooves formed in the radially extending walls of each and all recesses progressing in a spiral manner from their respective starting points out at the periphery of the recess inwardly to the central area; a plurality of rotors rotatably mounted to closely occupy the spaces as presented by the paired and matched recesses between all paired plates; a hollowed drive-shaft perforated at points adjacent to the termini of all spiral grooves; inlet ports at the starting points of all grooves and through all plates at common points to each respectively; and a common outlet passage presented by the hollow portion of the perforated hollowed drive-shaft of the molecular pump. (AEC)

  10. Motor actuated vacuum door

    NASA Astrophysics Data System (ADS)

    Hanagud, A. V.

    1986-10-01

    Doors that allow scientific instruments to record and retrieve the observed data are often required to be designed and installed as a part of sounding rocket hardware. The motor-actuated vacuum door was designed to maintain a medium vacuum of the order of 0.0001 torr or better while closed, and to provide an opening 15 inches long x 8.5 inches wide while open for cameras to image Halley's comet. When the electric motor receives the instruction to open the door through the payload battery, timer, and relay circuit, the first operation is to unlock the door. After unlatching, the torque transmitted by the motor to the main shaft through the links opens the door. A microswitch actuator, which rides on the linear motion conversion mechanism, is adjusted to trip the limit switch at the end of the travel. The process is repeated in the reverse order to close the door. 'O' rings are designed to maintain the seal. Door mechanisms similar to the one described have flown on Aerobee 17.018 and Black Brant 27.047 payloads.

  11. Accelerator Vacuum Protection System

    NASA Astrophysics Data System (ADS)

    Barua, Pradip; Kothari, Ashok; Archunan, M.; Joshi, Rajan

    2012-11-01

    A new and elaborate automatic vacuum protection system using fast acting valve has been installed to avoid accidental venting of accelerator from experimental chamber side. To cover all the beam lines and to reduce the system cost, it has been installed at a common point from where all the seven beam lines originate. The signals are obtained by placing fast response pressure sensing gauges (HV SENSOR) near all the experimental stations. The closing time of the fast valve is 10 milli-second. The fast closing system protects only one vacuum line at a time. At IUAC, we have seven beam lines so one sensor was placed in each of the beam lines near experimental chamber and a multiplexer was incorporated into the fast closing system. At the time of experiment, the sensor of the active beam line is selected through the multiplexer and the Fast closing valve is interlocked with the selected sensor. As soon as the pressure sensor senses the pressure rise beyond a selected pressure, the signal is transferred and the fast valve closes within 10 to 12 millisecond.

  12. Vacuum leak detector and method

    DOEpatents

    Edwards, Jr., David

    1983-01-01

    Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

  13. Vacuum metastability with black holes

    NASA Astrophysics Data System (ADS)

    Burda, Philipp; Gregory, Ruth; Moss, Ian G.

    2015-08-01

    We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evaporation process. Finally, we comment on the application of these results to vacuum decay seeded by black holes produced in particle collisions.

  14. LIGO vacuum system study

    NASA Technical Reports Server (NTRS)

    Livas, Jeffrey C.; Moore, Boude C.

    1988-01-01

    A laser interferometer gravitational wave observatory (LIGO) is being developed with sensitivities which will have a high probability of detecting gravitational waves from astrophysical sources. A major component of LIGO is a total of 16 km of 1.2 m (48 inch) diameter tube at a pressure of less than 10 to the minus 8th power torr. It will be of 304L stainless steel procured directly from the steel mills with the initial hydrogen content specially reduced. Projections of the outgassing rates of hydrogen and of water vapor as a function of time are given and the uncertainties discussed. Based on these, a preliminary analysis of the vacuum system is presented.

  15. ULTRA HIGH VACUUM VALVE

    DOEpatents

    Fry, W.A.

    1962-05-29

    A valve for high vacuum applications such as the CStellarator where chamber pressures as low as 2 x 10/sup -10/ mm Hg are necessary is designed with a line-of-sight path through the valve for visual inspection of the contents of reactants in such chambers. The valve comprises a turnable resilient metal ball having an aperture therethrough, means for selectively turning the ball to rotate the axis of its line-of-sight path, and soft, deformable opposing orifices that are movable relatively toward said ball to seal with opposite ball surfaces upon said movement of said axis of said line-of-sight path. The valve also includes a bellows seal connected between said orifices and internal actuating means that eliminates the requirement for gasketed turnable valve closing stems. (AEC)

  16. THERMOCOUPLE VACUUM GAUGE

    DOEpatents

    Price, G.W.

    1954-08-01

    A protector device is described for use in controlling the pressure within a cyclotron. In particular, an electrical circuit functions to actuate a vacuum pump when a predetermined low pressure is reached and disconnect the pump when the pressure increases abcve a certain value. The principal feature of the control circuit lies in the use of a voltage divider network at the input to a relay control tube comprising two parallel, adjustable resistances wherein one resistor is switched into the circuit when the relay connects the pump to a power source. With this arrangement the relay is energized at one input level received from a sensing element within the cyclotron chamber and is de-energized when a second input level, representing the higher pressure limit, is reached.

  17. Vacuum Energy Sequestering and Graviton Loops.

    PubMed

    Kaloper, Nemanja; Padilla, Antonio

    2017-02-10

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  18. Vacuum Energy Sequestering and Graviton Loops

    NASA Astrophysics Data System (ADS)

    Kaloper, Nemanja; Padilla, Antonio

    2017-02-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  19. Abdominal intrauterine vacuum aspiration.

    PubMed

    Tjalma, W A A

    2014-01-01

    Evaluating and "cleaning" of the uterine cavity is probably the most performed operation in women. It is done for several reasons: abortion, evaluation of irregular bleeding in premenopausal period, and postmenopausal bleeding. Abortion is undoubtedly the number one procedure with more than 44 million pregnancies terminated every year. This procedure should not be underestimated and a careful preoperative evaluation is needed. Ideally a sensitive pregnancy test should be done together with an ultrasound in order to confirm a uterine pregnancy, excluding extra-uterine pregnancy, and to detect genital and/or uterine malformations. Three out of four abortions are performed by surgical methods. Surgical methods include a sharp, blunt, and suction curettage. Suction curettage or vacuum aspiration is the preferred method. Despite the fact that it is a relative safe procedure with major complications in less than one percent of cases, it is still responsible for 13% of all maternal deaths. All the figures have not declined in the last decade. Trauma, perforation, and bleeding are a danger triage. When there is a perforation, a laparoscopy should be performed immediately, in order to detect intra-abdominal lacerations and bleeding. The bleeding should be stopped as soon as possible in order to not destabilize the patient. When there is a perforation in the uterus, this "entrance" can be used to perform the curettage. This is particularly useful if there is trauma of the isthmus and uterine wall, and it is difficult to identify the uterine canal. A curettage is a frequent performed procedure, which should not be underestimated. If there is a perforation in the uterus, then this opening can safely be used for vacuum aspiration.

  20. Vacuum flash evaporated polymer composites

    DOEpatents

    Affinito, J.D.; Gross, M.E.

    1997-10-28

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  1. Vacuum flash evaporated polymer composites

    DOEpatents

    Affinito, John D.; Gross, Mark E.

    1997-01-01

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  2. Vacuum Enhanced Cutaneous Biopsy Instrument

    SciTech Connect

    Collins, Joseph

    1999-06-25

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  3. Vacuum enhanced cutaneous biopsy instrument

    DOEpatents

    Collins, Joseph

    2000-01-01

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  4. Breather cloth for vacuum curing

    NASA Technical Reports Server (NTRS)

    Reed, M. W.

    1979-01-01

    Finely-woven nylon cloth that has been treated with Teflon improves vacuum adhesive bonding of coatings to substrates. Cloth is placed over coating; entire assembly, including substrate, coating, and cloth, is placed in plastic vacuum bag for curing. Cloth allows coating to "breathe" when bag is evacuated. Applications include bonding film coatings to solar concentrators and collectors.

  5. Multipurpose Vacuum Induction Processing System

    NASA Astrophysics Data System (ADS)

    Govindaraju, M.; Kulkarni, Deepak; Balasubramanian, K.

    2012-11-01

    Multipurpose vacuum processing systems are cost effective; occupy less space, multiple functional under one roof and user friendly. A multipurpose vacuum induction system was designed, fabricated and installed in a record time of 6 months time at NFTDC Hyderabad. It was designed to function as a) vacuum induction melting/refining of oxygen free electronic copper/pure metals, b) vacuum induction melting furnace for ferrous materials c) vacuum induction melting for non ferrous materials d) large vacuum heat treatment chamber by resistance heating (by detachable coil and hot zone) e) bottom discharge vacuum induction melting system for non ferrous materials f) Induction heat treatment system and g) directional solidification /investment casting. It contains provision for future capacity addition. The attachments require to manufacture multiple shaped castings and continuous rod casting can be added whenever need arises. Present capacity is decided on the requirement for 10years of development path; presently it has 1.2 ton liquid copper handling capacity. It is equipped with provision for capacity addition up to 2 ton liquid copper handling capacity in future. Provision is made to carry out the capacity addition in easy steps quickly. For easy operational maintenance and troubleshooting, design was made in easily detachable sections. High vacuum system is also is detachable, independent and easily movable which is first of its kind in the country. Detailed design parameters, advantages and development history are presented in this paper.

  6. Vacuum Gas Tungsten Arc Welding

    NASA Technical Reports Server (NTRS)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  7. Purifying Aluminum by Vacuum Distillation

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  8. Purifying Aluminum by Vacuum Distillation

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1985-01-01

    Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

  9. Cosmology with decaying vacuum energy

    SciTech Connect

    Freese, K.; Adams, F.; Frieman, J.; Mottola, E.

    1987-09-01

    Motivated by recent attempts to solve the cosmological constant problem, we examine the observational consequences of a vacuum energy density which decays in time. For all times later than t approx. 1 sec, the ratio of the vacuum to the total energy density of the universe must be small. Although the vacuum cannot provide the ''missing mass'' required to close the universe today, its presence earlier in the history of the universe could have important consequences. We discuss restrictions on the vacuum energy arising from primordial nucleosynthesis, the microwave and gamma ray background spectra, and galaxy formation. A small vacuum component at the era of nucleosynthesis, 0.01 < rho/sub vac//rho/sup rad/ < 0.1, increase the number of allowed neutino species to N/sup nu/ > 5, but in some cases would severely distort the microwave spectrum. 9 refs., 3 figs.

  10. Hadron Contribution to Vacuum Polarisation

    NASA Astrophysics Data System (ADS)

    Davier, M.; Hoecker, A.; Malaescu, B.; Zhang, Z.

    2016-10-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle-antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e- annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingredients to high precision tests of the Standard Theory.

  11. Bubbling the false vacuum away

    SciTech Connect

    Gleiser, M.; Rogers, B.; Thorarinson, J.

    2008-01-15

    We investigate the role of nonperturbative, bubblelike inhomogeneities on the decay rate of false-vacuum states in two- and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum, as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubblelike inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay--known as resonant nucleation--is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and crossover. Possible applications are briefly discussed.

  12. Vacuum Energy and Its Consequences

    NASA Astrophysics Data System (ADS)

    Hewett, Lionel

    2009-10-01

    Intuitively one would think that a perfect vacuum should contain no energy. However, quantum mechanics asserts that virtual particles popping in and out of existence too fast to be observed directly should produce a non-zero average energy density for empty space. This presentation discusses how quantum mechanics predicts too large a value for this energy density, how the Casimir effect correctly predicts the measured value of the vacuum energy between closely spaced objects, how time-symmetric cosmology predicts the energy density of interstellar space, how vacuum energy produces negative pressure, how vacuum energy causes the current universe to accelerate its expansion, and why vacuum energy cannot be tapped so as to produce an inexhaustible source of energy for all mankind.

  13. The AGS Booster vacuum systems

    SciTech Connect

    Hseuh, H.C.

    1989-01-01

    The AGS Booster is a synchrotron for the acceleration of both protons and heavy ions. The design pressure of low 10{sup {minus}11} mbar is required to minimize beam loss of the partially stripped heavy ions. To remove contaminants and to reduce outgassing, the vacuum chambers and the components located in them will be chemically cleaned, vacuum fired, baked then treated with nitric oxide. The vacuum sector will be insitu baked to a minimum of 200{degree}C and pumped by the combination of sputter ion pumps and titanium sublimation pumps. This paper describes the design and the processing of this ultra high vacuum system, and the performance of some half-cell vacuum chambers. 9 refs., 7 figs.

  14. Vacuum fiber-fiber coupler

    NASA Astrophysics Data System (ADS)

    Heinrici, Axel; Bjelajac, Goran; Jonkers, Jeroen; Jakobs, Stefan; Olschok, Simon; Reisgen, Uwe

    2017-02-01

    Research and development carried out by the ISF Welding and Joining Institute of RWTH Aachen University has proven that combining high power laser and low vacuum atmosphere provides a welding performance and quality, which is comparable to electron beam welding. The developed welding machines are still using a beam forming which takes place outside the vacuum and the focusing laser beam has to be introduced to the vacuum via a suitable window. This inflexible design spoils much of the flexibility of modern laser welding. With the target to bring a compact, lightweight flying optics with flexible laser transport fibers into vacuum chambers, a high power fiber-fiber coupler has been adapted by II-VI HIGHYAG that includes a reliable vacuum interface. The vacuum-fiber-fiber coupler (V-FFC) is tested with up to 16 kW sustained laser power and the design is flexible in terms of a wide variety of laser fiber plug systems and vacuum flanges. All that is needed to implement the V-FFC towards an existing or planned vacuum chamber is an aperture of at least 100 mm (4 inch) diameter with any type of vacuum or pressure flange. The V-FFC has a state-of-the-art safety interface which allows for fast fiber breakage detection for both fibers (as supported by fibers) by electric wire breakage and short circuit detection. Moreover, the System also provides connectors for cooling and electric signals for the laser beam optics inside the vacuum. The V-FFC has all necessary adjustment options for coupling the laser radiation to the receiving fiber.

  15. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  16. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  17. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  18. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  19. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  20. Vacuum Brazing of Accelerator Components

    NASA Astrophysics Data System (ADS)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  1. Thermal Vacuum Testing

    NASA Image and Video Library

    2017-09-27

    Engineers guiding the GPM Core Observatory into the thermal vacuum chamber. Credit: NASA/Goddard The Global Precipitation Measurement (GPM) mission is an international partnership co-led by NASA and the Japan Aerospace Exploration Agency (JAXA) that will provide next-generation global observations of precipitation from space. GPM will study global rain, snow and ice to better understand our climate, weather, and hydrometeorological processes. As of Novermber 2013 the GPM Core Observatory is in the final stages of testing at NASA Goddard Space Flight Center. The satellite will be flown to Japan in the fall of 2013 and launched into orbit on an HII-A rocket in early 2014. For more on the GPM mission, visit gpm.gsfc.nasa.gov/. NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  2. Vacuum plasma spray coating

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Mckechnie, Timothy N.

    1989-01-01

    Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

  3. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-10-27

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

  4. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and variious laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels.

  5. Vacuum phenomenon: Clinical relevance.

    PubMed

    Gohil, Ishan; Vilensky, Joel A; Weber, Edward C

    2014-04-01

    Vacuum phenomenon (VP) is an anatomical entity of potential confusion in the diagnosis and evaluation of joint pathology. Observation of this phenomenon has been demonstrated on basic radiographs, computed tomography, and magnetic resonance imaging. Although VP is most often associated with degenerative joint disease, it is observed with other pathologies. Two problematic scenarios can occur: a false-positive diagnosis of serious pathology instead of benign VP and a false-negative diagnosis of benign VP with a more serious underlying process Despite this potential for confusion, criteria for distinguishing VP from other causes of joint pain and for evaluating a suspected case of VP have not been fully established. We reviewed the literature to determine underlying mechanism, symptomology, associated pathologies, and clinical importance of VP. The formation of VP can be explained by gas solubility, pressure-volume relationships, and human physiology. CT, GRE-MRI, and multipositional views are the best imaging studies to view VP. Although most cases of VP are benign, it can be associated with clinical signs and symptoms. VP outside the spine is an underreported finding on imaging studies. VP should be on the differential diagnosis for joint pain, especially in the elderly. We have proposed criteria for diagnosing VP and generated a basic algorithm for its workup. Underreporting of this phenomenon shows a lack of awareness of VP on the part of physicians. By identifying true anatomic VP, we can prevent harm from suboptimal treatment of patients.

  6. Vacuum still bottoms viscometer

    SciTech Connect

    Dinsmore, T.V.; Wilson, J.H.

    1985-01-01

    A viscometer system that is capable of measuring VSB viscosity on-line has been designed, constructed, and tested. The viscometer will not only provide continuous on-line measurements for process control purposes, but will also determine viscosity as functions of temperature and shear rate. The latter results may be used to verify design-base information for direct coal liquefaction demonstration plants. The viscosities of Wilsonville samples of VSB and LSRC were determined as functions of shear rate and, in the case of LSRC, temperature. The VSB viscosity was found to be shear-rate sensitive, while the LSRC viscosity was temperature sensitive. A 24-h test run was unsuccessful, apparently because the check valves in the pump plugged; however, all other mechanical, electrical, and electronic equipment operated satisfactorily. The source of the plugging was thought to be degradation products, which should not cause difficulties in the pilot plant where fresh vacuum bottoms feed is always available. In summary, the results obtained in this study indicate that the viscometer system is ready to be transported to a plant such as Wilsonville and operated on-line. 7 figs., 5 tabs.

  7. Precooler Ring Vacuum System

    SciTech Connect

    Moenich, J.

    1980-10-02

    The precooler vacuum system, as proposed by FNAL, is based on a suitable modification of the existing Electron Cooling Ring System. Because of the magnetic cycle of the bending magnets, distributed ion pumping, as exists in the Electron Cooling Ring, is not applicable. Instead, the proposed pumping will be done with commercial appendage ion pumps mounted approximately every two meters around the circumference of the ring. The loss of effective pumping speed and non-uniformity of system pressure with appendage pumps may not be major considerations but the large number required does effect experimental and analytical equipment placement considerations. There is a distributed pumping technique available which: (1) is not affected by the magnetic cycle of the bending magnets; (2) will provide a minimum of four times the hydrogen pumping speed of the proposed appendage ion pumps; (3) will require no power during pumping after the strip is activated; (4) will provide the heat source for bakeout; (5) is easily replaceable; and (6) can be purchased, installed, and operated at a generous economic advantage over the presently proposed ion pumped system. The pumping technique referred to is non-evaporable gettering with ST101 Zr/Al pumping strip. A technical description of this pumping strip is given on Data Sheet 1 and 2 attached to this report.

  8. Quantum Vacuum Pathway Theory

    NASA Astrophysics Data System (ADS)

    Habegger, Eric John

    2005-02-01

    It is theorized that the quantum vacuum is a random electromagnetic field that permeates the universe. It will be shown that acceleration between a quark and a random electromagnetic energy field is an analog of the reaction between a charge moving at constant velocity with respect to an organized electromagnetic field. The difference is that with a quark any natural perpendicular deflection during that motion, as predicted by Lorentz, is contained by the strong force, which results in a change in the angular momentum of the spin of a quark. The first derivative of the equations of motion of charges in an organized electromagnetic field may be used when applied to a random electromagnetic field to invoke the same fields modeled by Maxwell's equations. Mass is intimately bound up with a quark's spin angular momentum and the energy for that increase comes directly from the local field. The underlying randomness of the local field normally remains intact through these energy exchanges but it is speculated that in a quantum entanglement, an absolute level of order is imposed on the field along a path between two particles. This causes the non local effects seen in quantum entanglement. The mechanism that may cause this effect is discussed and a simple experiment is proposed that can test the hypothesis. Also discussed are new theoretical constructs for electromagnetic radiation, mass, the skin effect, self-inductance, superposition, and gravity. The emphasis will be on an intuitive and logical approach more than a mathematical approach.

  9. Fume incinerator with vacuum baffle

    SciTech Connect

    Houston, R.

    1994-01-04

    A single unit, shell and tube fume incinerator utilizes a vacuum baffle structure proximate a combustion zone to control the flow of combustion exhaust gas. The vacuum baffle is located slightly above the hot ends of a plurality of heat exchange tubes to deflect the hot exhaust gases from the combustion zone away from the ends of the tubes, and back to the outside of the tubes, thereby controlling the time at temperature'' for contaminants in the impure gas feed. A vacuum effect is created just below the baffle to draw cleansed exhaust below the baffle back up into the combustion zone to prevent the escape of impure gas. 3 figs.

  10. (Higgs) vacuum decay during inflation

    NASA Astrophysics Data System (ADS)

    Joti, Aris; Katsis, Aris; Loupas, Dimitris; Salvio, Alberto; Strumia, Alessandro; Tetradis, Nikolaos; Urbano, Alfredo

    2017-07-01

    We develop the formalism for computing gravitational corrections to vacuum decay from de Sitter space as a sub-Planckian perturbative expansion. Non-minimal coupling to gravity can be encoded in an effective potential. The Coleman bounce continuously deforms into the Hawking-Moss bounce, until they coincide for a critical value of the Hubble constant. As an application, we reconsider the decay of the electroweak Higgs vacuum during inflation. Our vacuum decay computation reproduces and improves bounds on the maximal inflationary Hubble scale previously computed through statistical techniques.

  11. Simulation modelling in vacuum engineering

    NASA Astrophysics Data System (ADS)

    Dmitrieva, V. V.; Averyanov, G. P.; Ulin, S. E.

    2017-01-01

    The article deals with the latest version of a computer part of Vacuum Engineering laboratory in which means of fragmentary pumping and receiving of fine vacuum are studied. The virtual laboratory allows to carry out a heatup and processing of preselected surface materials of the pumped-out objects in acceptable time limits by using any means of preselected pumping (from the built-in database). It is possible to retrace online dynamics of receiving fine vacuum in time by having started the procedure of pumping.

  12. Vacuum applications of metal foams

    NASA Technical Reports Server (NTRS)

    Kendall, B. R. F.

    1980-01-01

    Several vacuum applications of copper foams in the density range 2-5% and pore sizes of 0.5-0.7 mm are discussed, such as a foreline hydrocarbon trap in a mechanical vacuum pump, a molecular-flow resistor, a diffuser, and a water injector. Other suggested applications include the use of foam copper in the form of an externally heated plug to remove traces of oxygen from inert gases bled into a vacuum system through a stainless steel line and the use of the porous surface for minimizing release of secondary electrons from electrodes in the path of charged particle beams.

  13. Photoelectron backscattering in vacuum phototubes

    NASA Astrophysics Data System (ADS)

    Lubsandorzhiev, B. K.; Vasiliev, R. V.; Vyatchin, Y. E.; Shaibonov, B. A. J.

    2006-11-01

    In this article we describe results of studies of a photoelectron backscattering effect in vacuum phototubes: classical photomultipliers (PMT) and hybrid phototubes (PH). Late pulses occurring in PMTs are attributed to the photoelectron backscattering and distinguished from pulses due to an anode glow effect. The late pulses are measured in a number of PMTs and HPs with various photocathode sizes covering 1 50 cm range and different types of the first dynode materials and construction designs. It is shown that the late pulses are a generic feature of all vacuum photodetectors—PMTs and PHs—and they do not deteriorate dramatically amplitude and timing responses of vacuum phototubes.

  14. Vacuum-Assisted Vaginal Delivery

    PubMed Central

    Ali, Unzila A; Norwitz, Errol R

    2009-01-01

    Approximately 5% (1 in 20) of all deliveries in the United States are operative vaginal deliveries. The past 20 years have seen a progressive shift away from the use of forceps in favor of the vacuum extractor as the instrument of choice. This article reviews in detail the indications, contraindications, patient selection criteria, choice of instrument, and technique for vacuum-assisted vaginal delivery. The use of vacuum extraction at the time of cesarean delivery will also be discussed. With vacuum extraction becoming increasingly popular, it is important that obstetric care providers are aware of the maternal and neonatal risks associated with such deliveries and of the options available to effect a safe and expedient delivery. PMID:19399290

  15. [Wound healing after vacuum drainage].

    PubMed

    Davydov, Iu A; Larichev, A B; Abramov, A Iu

    1992-01-01

    Vacuum therapy was applied in the management of 63 patients with postoperative ventral hernias, 101 patients with a similar pathological conditions were treated by the traditional method for wound healing. From analysis of the results of treatment and with due consideration for the results of additional methods of examination it was established that vacuum prevents accumulation of exudate and blood clots in the wound cavity and removes the risk medium for the development of pyo-inflammatory complications. Moreover, by promoting the coming together of the wound edges and liquidation of the wound cavity, vacuum therapy affects the metabolic reorganizations in the tissues and leads to stabilization of the regeneration mechanisms. The use of vacuum therapy in the postoperative period creates the possibility of regulating the reparative reactions through an active effect on the healing of the wound in the phase of inflammation, protecting in this manner the biology of the wound process and preventing infectious complications.

  16. Alumina barrier for vacuum brazing

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.

    1980-01-01

    Heating platens of vacuum-brazing press will not stick to workpiece if aluminum oxide "paper" is interposed. Paper does not disintegrate in press, will not contaminate braze alloy, and helps form smoothly contoured, regular fillet at brazed edges.

  17. APS storage ring vacuum system

    SciTech Connect

    Niemann, R.C.; Benaroya, R.; Choi, M.; Dortwegt, R.J.; Goeppner, G.A.; Gonczy, J.; Krieger, C.; Howell, J.; Nielsen, R.W.; Roop, B.; Wehrle, R.B.

    1990-01-01

    The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's experimental program. The Storage Ring's 1104 m circumference is divided into 40 functional sectors. The sectors include vacuum, beam transport, control, acceleration and insertion device components. The vacuum system, which is designed to operate at a pressure of 1 n Torr, consists of 240 connected sections, the majority of which are fabricated from an aluminum alloy extrusion. The sections are equipped with distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. The details of the vacuum system design, selected results of the development program and general construction plans are presented. 11 refs., 6 figs., 3 tabs.

  18. IRIS Leaves Thermal Vacuum Chamber

    NASA Image and Video Library

    This video shows the transportation of the IRIS observatory from the thermal vacuum chamber back to the clean tent for final testing and preparations for delivery to the launch site at Vandenberg A...

  19. Alumina barrier for vacuum brazing

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.

    1980-01-01

    Heating platens of vacuum-brazing press will not stick to workpiece if aluminum oxide "paper" is interposed. Paper does not disintegrate in press, will not contaminate braze alloy, and helps form smoothly contoured, regular fillet at brazed edges.

  20. Silicon source for vacuum deposition

    NASA Technical Reports Server (NTRS)

    Racette, G. W.; Rutecki, D. J.

    1979-01-01

    Device using two independent silicon sources for ultra-high-vacuum deposition on large substrates can deposit P and N types of silicon simultaneously. Efficient water cooled copper shield supports and cools structure and isolates two filaments.

  1. Electric Propulsion Laboratory Vacuum Chamber

    NASA Image and Video Library

    1964-06-21

    Engineer Paul Reader and his colleagues take environmental measurements during testing of a 20-inch diameter ion engine in a vacuum tank at the Electric Propulsion Laboratory (EPL). Researchers at the Lewis Research Center were investigating the use of a permanent-magnet circuit to create the magnetic field required power electron bombardment ion engines. Typical ion engines use a solenoid coil to create this magnetic field. It was thought that the substitution of a permanent magnet would create a comparable magnetic field with a lower weight. Testing of the magnet system in the EPL vacuum tanks revealed no significant operational problems. Reader found the weight of the two systems was similar, but that the thruster’s efficiency increased with the magnet. The EPL contained a series of large vacuum tanks that could be used to simulate conditions in space. Large vacuum pumps reduced the internal air pressure, and a refrigeration system created the cryogenic temperatures found in space.

  2. Vacuum lamination of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1982-01-01

    Vacuum lamination of terrestrial photovoltaic modules is a new high volume process requiring new equipment and newly develop materials. Equipment development, materials research, and some research in related fields and testing methods are discussed.

  3. [Endoscopic vacuum-assisted closure].

    PubMed

    Wedemeyer, J; Lankisch, T

    2013-03-01

    Anastomotic leakage in the upper and lower intestinal tract is associated with high morbidity and mortality. Within the last 10 years endoscopic treatment options have been accepted as sufficient treatment option of these surgical complications. Endoscopic vacuum assisted closure (E-VAC) is a new innovative endoscopic therapeutic option in this field. E-VAC transfers the positive effects of vacuum assisted closure (VAC) on infected cutaneous wounds to infected cavities that can only be reached endoscopically. A sponge connected to a drainage tube is endoscopically placed in the leakage and a continuous vacuum is applied. Sponge and vacuum allow removal of infected fluids and promote granulation of the leakage. This results in clean wound grounds and finally allows wound closure. Meanwhile the method was also successfully used in the treatment of necrotic pancreatitis.

  4. VACUUM DEPOSITION OF THIN FILMS,

    DTIC Science & Technology

    The book deals with methods of obtaining and processing thin films , methods of measuring the deposition rate and thickness of thin-film layers, and...the main fields of application of thin films . Vacuum requirements and the requirements for the composition of the residual medium in thermal...evaporation and cathode sputtering are given, and modern methods of producing and measuring vacuums and the equipment used in obtaining thin films are described. (Author)

  5. Technical specification for vacuum systems

    SciTech Connect

    Khaw, J.

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)

  6. Cold cathode vacuum gauging system

    DOEpatents

    Denny, Edward C.

    2004-03-09

    A vacuum gauging system of the cold cathode type is provided for measuring the pressure of a plurality of separate vacuum systems, such as in a gas centrifuge cascade. Each casing is fitted with a gauge tube assembly which communicates with the vacuum system in the centrifuge casing. Each gauge tube contains an anode which may be in the form of a slender rod or wire hoop and a cathode which may be formed by the wall of the gauge tube. The tube is provided with an insulated high voltage connector to the anode which has a terminal for external connection outside the vacuum casing. The tube extends from the casing so that a portable magnet assembly may be inserted about the tube to provide a magnetic field in the area between the anode and cathode necessary for pressure measurements in a cold cathode-type vacuum gauge arrangement. The portable magnetic assembly is provided with a connector which engages the external high voltage terminal for providing power to the anode within in the gauge tube. Measurement is made in the same manner as the prior cold cathode gauges in that the current through the anode to the cathode is measured as an indication of the pressure. By providing the portable magnetic assembly, a considerable savings in cost, installation, and maintenance of vacuum gauges for pressure measurement in a gas centrifuge cascade is realizable.

  7. Vacuum Systems Consensus Guideline for Department of Energy Accelerator Laboratories

    SciTech Connect

    Casey,R.; Haas, E.; Hseuh, H-C.; Kane, S.; Lessard, E.; Sharma, S.; Collins, J.; Toter, W. F.; Olis, D. R.; Pushka, D. R.; Ladd, P.; Jobe, R. K.

    2008-09-09

    Vacuum vessels, including evacuated chambers and insulated jacketed dewars, can pose a potential hazard to equipment and personnel from collapse, rupture due to back-fill pressurization, or implosion due to vacuum window failure. It is therefore important to design and operate vacuum systems in accordance with applicable and sound engineering principles. 10 CFR 851 defines requirements for pressure systems that also apply to vacuum vessels subject to back-fill pressurization. Such vacuum vessels are potentially subject to the requirements of the American Society of Mechanical Engineers (ASME) Pressure Vessel Code Section VIII (hereafter referred to as the 'Code'). However, the scope of the Code excludes vessels with internal or external operating pressure that do not exceed 15 pounds per square inch gauge (psig). Therefore, the requirements of the Code do not apply to vacuum systems provided that adequate pressure relief assures that the maximum internal pressure within the vacuum vessel is limited to less than 15 psig from all credible pressure sources, including failure scenarios. Vacuum vessels that cannot be protected from pressurization exceeding 15 psig are subject to the requirements of the Code. 10 CFR 851, Appendix A, Part 4, Pressure Safety, Section C addresses vacuum system requirements for such cases as follows: (c) When national consensus codes are not applicable (because of pressure range, vessel geometry, use of special materials, etc.), contractors must implement measures to provide equivalent protection and ensure a level of safety greater than or equal to the level of protection afforded by the ASME or applicable state or local code. Measures must include the following: (1) Design drawings, sketches, and calculations must be reviewed and approved by a qualified independent design professional (i.e., professional engineer). Documented organizational peer review is acceptable. (2) Qualified personnel must be used to perform examinations and

  8. Vacuum-jacketed hydrofluoric acid solution calorimeter

    USGS Publications Warehouse

    Robie, R.A.

    1965-01-01

    A vacuum-jacketed metal calorimeter for determining heats of solution in aqueous HF was constructed. The reaction vessel was made of copper and was heavily gold plated. The calorimeter has a cooling constant of 0.6 cal-deg -1-min-1, approximately 1/4 that of the air-jacketed calorimeters most commonly used with HF. It reaches equilibrium within 10 min after turning off the heater current. Measurements of the heat of solution of reagent grade KCl(-100 mesh dried 2 h at 200??C) at a mole ratio of 1 KCl to 200 H2O gave ??H = 4198??11 cal at 25??C. ?? 1965 The American Institute of Physics.

  9. Vacuum-Gauge Connection For Shipping Container

    NASA Technical Reports Server (NTRS)

    Henry, Robert H.

    1990-01-01

    External connector enables measurement of vacuum in stored part. Remote-readout connector added to shipping container and connected to thermo-couple vacuum gauge in vacuum-insulated cryogenic line packed in container. Enables monitoring of condition of vacuum without opening container.

  10. Vacuum-Gauge Connection For Shipping Container

    NASA Technical Reports Server (NTRS)

    Henry, Robert H.

    1990-01-01

    External connector enables measurement of vacuum in stored part. Remote-readout connector added to shipping container and connected to thermo-couple vacuum gauge in vacuum-insulated cryogenic line packed in container. Enables monitoring of condition of vacuum without opening container.

  11. Vacuum Packaging for Microelectromechanical Systems (MEMS)

    DTIC Science & Technology

    2002-10-01

    The Vacuum Packaging for MEMS Program focused on the development of an integrated set of packaging technologies which in totality provide a low cost...high volume product-neutral vacuum packaging capability which addresses all MEMS vacuum packaging requirements. The program balanced the need for...near term component and wafer-level vacuum packaging with the development of advanced high density wafer-level packaging solutions. Three vacuum

  12. Probability distribution of the vacuum energy density

    SciTech Connect

    Duplancic, Goran; Stefancic, Hrvoje; Glavan, Drazen

    2010-12-15

    As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.

  13. Measurement of partial pressures in vacuum technology and vacuum physics

    NASA Technical Reports Server (NTRS)

    Huber, W. K.

    1986-01-01

    It is pointed out that the measurement of gaseous pressures of less than 0.0001 torr is based on the ionization of gas atoms and molecules due to collisions with electrons. The particle density is determined in place of the pressure. The ionization cross sections for molecules of various gases are discussed. It is found that the true pressure in a vacuum system cannot be determined with certainty if it is unknown which gas is present. Effects of partial pressure determination on the condition of the vacuum system are discussed together with ion sources, systems of separation, and ion detection.

  14. VACUUM TRAP AND VALVE COMBINATION

    DOEpatents

    Milleron, N.; Levenson, L.

    1963-02-19

    This patent relates to a vacuum trap and valve combination suitable for use in large ultra-high vacuum systems. The vacuum trap is a chamber having an inlet and outlet opening which may be made to communicate with a chamber to be evacuated and a diffusion pump, respectively. A valve is designed to hermeticaliy seal with inlet opening and, when opened, block the line-of- sight'' between the inlet and outlet openings, while allowing a large flow path between the opened vaive and the side walls of the trap. The interior of the trap and the side of the valve facing the inlet opening are covered with an impurity absorbent, such as Zeolite or activated aluminum. Besides the advantage of combining two components of a vacuum system into one, the present invention removes the need for a baffle between the pump and the chamber to be evacuated. In one use of a specific embodiment of this invention, the transmission probability was 45 and the partial pressure of the pump fluid vapor in the vacuum chamber was at least 100 times lower than its vapor pressure. (AEC)

  15. Vacuum-assisted cesarean section

    PubMed Central

    McQuivey, Ross W; Block, Jon E

    2017-01-01

    There has been a dramatic rise in the frequency of cesarean sections, surpassing 30% of all deliveries in the US. This upsurge, coupled with a decreasing willingness to allow vaginal birth after cesarean section, has resulted in an expansion of the use of vacuum assistance to safely extract the fetal head. By avoiding the use of a delivering hand or forceps blade, the volume being delivered through the uterine incision can be decreased when the vacuum is used properly. Reducing uterine extensions with their associated complications (eg, excessive blood loss) in difficult cases is also a theoretical advantage of vacuum delivery. Maternal discomfort related to excessive fundal pressure may also be lessened. To minimize the risk of neonatal morbidity, proper cup placement over the “flexion point” remains essential to maintain vacuum integrity and reduce the chance of inadvertent detachment and uterine extensions. Based on the published literature and pragmatic clinical experience, utilization of the vacuum device is a safe and effective technique to assist delivery during cesarean section. PMID:28331371

  16. D-Zero Vacuum System

    SciTech Connect

    Wintercorn, S.J.; /Fermilab

    1986-04-07

    The system pumping speed was calculated by taking the reciprocal of the sum of the reciprocal pump speed and the reciprocal line conductances. The conductances of the pipe were calculated from the following formulas taken from the Varian vacuum manual. This report updates the original to reflect the pumping curves and basic vacuum system characteristics for the purchased components and installed piping of the D-Zero vacuum system. The system consists of two Edward's E2M275 two stage mechanical pumps, a Leybold-Heraeus WSU2000 Blower and three Varian 4' diffusion pumps (one for each cryostat). Individual pump and system pumping speed curves and a diagram of the system is included.

  17. Microscale Digital Vacuum Electronic Gates

    NASA Technical Reports Server (NTRS)

    Manohara, Harish (Inventor); Mojarradi, Mohammed M. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement microscale digital vacuum electronic gates. In one embodiment, a microscale digital vacuum electronic gate includes: a microscale field emitter that can emit electrons and that is a microscale cathode; and a microscale anode; where the microscale field emitter and the microscale anode are disposed within at least a partial vacuum; where the microscale field emitter and the microscale anode are separated by a gap; and where the potential difference between the microscale field emitter and the microscale anode is controllable such that the flow of electrons between the microscale field emitter and the microscale anode is thereby controllable; where when the microscale anode receives a flow of electrons, a first logic state is defined; and where when the microscale anode does not receive a flow of electrons, a second logic state is defined.

  18. Gravity-Induced Vacuum Dominance

    SciTech Connect

    Lima, William C. C.; Vanzella, Daniel A. T.

    2010-04-23

    It has been widely believed that, except in very extreme situations, the influence of gravity on quantum fields should amount to just small, subdominant contributions. This view seemed to be endorsed by the seminal results obtained over the last decades in the context of renormalization of quantum fields in curved spacetimes. Here, however, we argue that this belief is false by showing that there exist well-behaved spacetime evolutions where the vacuum energy density of free quantum fields is forced, by the very same background spacetime, to become dominant over any classical energy-density component. By estimating the time scale for the vacuum energy density to become dominant, and therefore for backreaction on the background spacetime to become important, we argue that this (infrared) vacuum dominance may bear unexpected astrophysical and cosmological implications.

  19. Gravity-induced vacuum dominance.

    PubMed

    Lima, William C C; Vanzella, Daniel A T

    2010-04-23

    It has been widely believed that, except in very extreme situations, the influence of gravity on quantum fields should amount to just small, subdominant contributions. This view seemed to be endorsed by the seminal results obtained over the last decades in the context of renormalization of quantum fields in curved spacetimes. Here, however, we argue that this belief is false by showing that there exist well-behaved spacetime evolutions where the vacuum energy density of free quantum fields is forced, by the very same background spacetime, to become dominant over any classical energy-density component. By estimating the time scale for the vacuum energy density to become dominant, and therefore for backreaction on the background spacetime to become important, we argue that this (infrared) vacuum dominance may bear unexpected astrophysical and cosmological implications.

  20. Method for vacuum fusion bonding

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2001-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  1. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

  2. Silicon crystal growth in vacuum

    NASA Technical Reports Server (NTRS)

    Khattak, C. P.; Schmid, F.

    1982-01-01

    The most developed process for silicon crystal growth is the Czochralski (CZ) method which was in production for over two decades. In an effort to reduce cost of single crystal silicon for photovoltaic applications, a directional solidification technique, Heat Exchanger Method (HEM), was adapted. Materials used in HEM and CZ furnaces are quite similar (heaters, crucibles, insulation, etc.). To eliminate the cost of high purity argon, it was intended to use vacuum operation in HEM. Two of the major problems encountered in vacuum processing of silicon are crucible decomposition and silicon carbide formation in the melt.

  3. Vacuum Cleaner Fan Being Improved

    NASA Technical Reports Server (NTRS)

    Tweedt, Daniel L.

    1997-01-01

    As part of the technology utilization program at the NASA Lewis Research Center, efforts are underway to transfer aerospace technologies to new areas of practical application. One such effort involves using advanced computational fluid dynamics (CFD) codes for turbomachinery to analyze the internal fluid dynamics of low-speed fans and blowers. This year, the Kirby Company in Cleveland, Ohio, approached NASA with a request for technologies that could help them improve their vacuum cleaners. Of particular interest to Kirby is the high-frequency blade-passing noise generation of their vacuum cleaner fan at low airflow rates.

  4. Vacuum-jacketed line spacer

    NASA Technical Reports Server (NTRS)

    Houte, F. A.; Mckee, H. B.; Patten, T. C.

    1976-01-01

    Device has three integral, equally spaced leaf springs. Springs separate outer vacuum jacket from fluid carrying line, yet minimize conductive heat leaks and liquid boiloff. One-piece heat spring has sufficient flexibility to accommodate differential thermal expansion of inner and outer line.

  5. Vacuum-insulated catalytic converter

    DOEpatents

    Benson, David K.

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  6. Plates for vacuum thermal fusion

    DOEpatents

    Davidson, James C.; Balch, Joseph W.

    2002-01-01

    A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

  7. Vacuum Flushing of Sewer Solids

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  8. Degassing procedure for ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Moore, B. C.

    1979-01-01

    Calculations based on diffusion coefficients and degassing rates for stainless-steel vacuum chambers indicate that baking at lower temperatures for longer periods give lower ultimate pressures than rapid baking at high temperatures. Process could reduce pressures in chambers for particle accelerators, fusion reactors, material research, and other applications.

  9. Cleaner Vacuum-Bag Curing

    NASA Technical Reports Server (NTRS)

    Clemons, J. M.; Penn, B. G.; Ledbetter, Frank E., III; Daniels, J. G.

    1987-01-01

    Improvement upon recommended procedures saves time and expense. Autoclave molding in vacuum bag cleaner if adhesive-backed covering placed around caul plate as well as on mold plate. Covering easy to remove after curing and leaves caul plate free of resin deposits.

  10. Vacuum mounting for piezoelectric transducers

    NASA Technical Reports Server (NTRS)

    Tiede, D. A.

    1977-01-01

    Special housing couples piezoelectric transducers to nonporous surfaces for ultrasonic or acoustic-emission testing. Device, while providing sound isolation on flat or nonflat surfaces, can be attached and detached quickly. Vacuum sealing mechanism eliminates need for permanent or semipermanent bonds, viscous coupling liquids, weights, magnets, tape, or springs ordinarily used.

  11. Vacuum barrier for excimer lasers

    DOEpatents

    Shurter, R.P.

    1992-09-15

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput. 3 figs.

  12. Vacuum barrier for excimer lasers

    DOEpatents

    Shurter, Roger P.

    1992-01-01

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

  13. Quantum gravity without vacuum dispersion

    NASA Astrophysics Data System (ADS)

    Coumbe, D. N.

    A generic prediction of quantum gravity is the vacuum dispersion of light, and hence that a photon’s speed depends on its energy. We present further numerical evidence for a scale-dependent speed of light in the causal dynamical triangulation (CDT) approach to quantum gravity. We show that the observed scale-dependent speed of light in CDT can be accounted for by a scale-dependent transformation of geodesic distance, whose specific functional form implies a discrete equidistant area spectrum. We make two nontrivial tests of the proposed scale transformation: a comparison with the leading-order quantum correction to the gravitational potential and a comparison with the generalized uncertainty principle. In both cases, we obtain the same functional form. However, contrary to the widespread prediction of vacuum dispersion in quantum gravity, numerous experiments have now definitively ruled out linear vacuum dispersion beyond Planckian energy scales EP, and have even constrained quadratic dispersion at the level ˜ 10‑8E P. Motivated by these experimental constraints, we seek to reconcile quantum gravity with the absence of vacuum dispersion. We point out that given a scale-dependent geodesic distance, a scale-dependent time interval becomes essential to maintaining an invariant speed of light. We show how a particular scale-dependent time interval allows a photon’s speed to remain independent of its energy.

  14. Quantum Vacuum Structure and Cosmology

    SciTech Connect

    Rafelski, Johann; Labun, Lance; Hadad, Yaron; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC

    2011-12-05

    Contemporary physics faces three great riddles that lie at the intersection of quantum theory, particle physics and cosmology. They are: (1) The expansion of the universe is accelerating - an extra factor of two appears in the size; (2) Zero-point fluctuations do not gravitate - a matter of 120 orders of magnitude; and (3) The 'True' quantum vacuum state does not gravitate. The latter two are explicitly problems related to the interpretation and the physical role and relation of the quantum vacuum with and in general relativity. Their resolution may require a major advance in our formulation and understanding of a common unified approach to quantum physics and gravity. To achieve this goal we must develop an experimental basis and much of the discussion we present is devoted to this task. In the following, we examine the observations and the theory contributing to the current framework comprising these riddles. We consider an interpretation of the first riddle within the context of the universe's quantum vacuum state, and propose an experimental concept to probe the vacuum state of the universe.

  15. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    Dr. M.A. Ebadian

    2000-01-13

    The purpose of the project is to increase the productivity and economics of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCB's and lead-base paint and provides worker and environmental protection by continuously recycling the blast media and the full containment of the dust generated in the process.

  16. Vacuum pumping system for TPX

    SciTech Connect

    St. Onge, K.D.

    1995-12-31

    The design of the vacuum pumping system for is discussed, and progress in the research and development effort is summarized. The TPX vacuum system will use cryocondensation pumps for hydrogenic divertor pumping and turbomolecular pumps for torus evacuation, glow discharge cleaning, and deuterium-helium divertor pumping. A set of poloidally and toroidally symmetric vacuum ducts will connect the torus to the vacuum pumps; this symmetry will permit simultaneous equal pumping speed at the upper and lower divertors, and it will minimize toroidal variations in divertor pumping speed. At the divertor plena the total cryocondensation pumping speed for D{sub 2} at 65 C and 1 mTorr will be 80 m{sup 3}/s and the total turbomolecular pumping speed for D{sub 2} or He at 65 C and 1 mTorr will be 18 m{sup 3}/s; the system will be compatible with upgrades to improve pumping speed, to operate continuously, or to operate with D-T fuel. The cryocondensation pumps will be custom units capable of completing a low temperature regeneration cycle in 1 hour.

  17. A vacuum ultraviolet spectrophotometric system

    NASA Technical Reports Server (NTRS)

    Spann, James F.; Keffer, Charles E.; Zukic, Muamer

    1993-01-01

    The development of a vacuum ultraviolet spectrophotometric system for measuring transmittance and reflectance at variable angles is presented. Using various detectors and sources, the spectrophotometric system has been used for wavelengths from 80 nm to 300 nm with optical components up to 80 mm in diameter. The capability exists to make measurements through the visible range.

  18. Conformal invariant vacuum nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Denisov, V. I.; Dolgaya, E. E.; Sokolov, V. A.; Denisova, I. P.

    2017-08-01

    In this paper, a general case of conformal invariant vacuum nonlinear electrodynamics is studied. We analyze the consistency of this electrodynamics model with fundamental principles such as causality, unitarity, and the Ellis-Hawking dominant energy condition. Certain features of the electromagnetic waves in this model are investigated.

  19. Degassing procedure for ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Moore, B. C.

    1979-01-01

    Calculations based on diffusion coefficients and degassing rates for stainless-steel vacuum chambers indicate that baking at lower temperatures for longer periods give lower ultimate pressures than rapid baking at high temperatures. Process could reduce pressures in chambers for particle accelerators, fusion reactors, material research, and other applications.

  20. Vacuum Flushing of Sewer Solids

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  1. Regulating vacuum pump speed with feedback control

    SciTech Connect

    Ludington, D.C.; Aneshansley, D.J.; Pellerin, R.; Guo, F.

    1992-01-01

    Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m{sup 3}/min or cfm) of the vacuum pump always exceeds the capacity needed to milk cows and wash pipelines. Vacuum pumps run at full speed and load regardless of actual need for air. Excess air is admitted through a controller. Energy can be saved from electrical demand reduced by regulating vacuum pump speed according to air based on air usage. An adjustable speed drive (ASD) on the motor and controlled based upon air usage, can reduce the energy used by the vacuum pump. However, the ASD unit tested could not maintain vacuum levels within generally accepted guidelines when air usage changed. Adding a high vacuum reserve and a dual vacuum controller between the vacuum pump and the milking pipeline brought vacuum stability within guidelines. The ASD/dual vacuum system can reduce energy consumption and demand by at least 50 percent during milking and provide better vacuum stability than conventional systems. Tests were not run during washing cycles. Using 1990 costs and only the energy saved during milking, the simple payback on investment in new equipment for a 5 hp motor, speed controller and vacuum regulator would be about 5 years.

  2. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    1999-05-31

    The objective of this project is to improve the productivity and lower the expense of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCBs, and lead-based paint and provides worker protection by continuously recycling the material and dust for the decontamination tasks. The proposed work would increase the cleaning rate and provide safe and cost-effective decontamination of the DOE sites. This work focuses on redesigning and improving existing vacuum blasting technology including blast head nozzles, ergonomic handling of the blast head by reducing its weight; brush-ring design, vacuum level regulator, efficiency of the dust separator, and operational control sensors. The redesign is expected to enhance the productivity and economy of the vacuum blasting system by at least 50% over current vacuum blasting systems. There are three phases in the project. Phase I consists of developing and testing mathematical models. Phase II consists of pre-prototype design and fabrication and pre-prototype unit testing. Phase III consists of prototype design and field verification testing. In phase I, mathematical models are developed and analyzed for the nozzle, blast head, wind curtain, and dust separator, first as individual devices and then combined as an integrated model. This allows study of respective airflow and design parameters. The Contractor shall, based on the results of the mathematical modeling studies, design experimental models of the components and test these models. In addition, the Contractor shall develop sensors to detect the relationship of the blast head to the blast surfaces and controls to minimize the dependency on an operator's skill and judgment to obtain optimum positioning, as well as real-time characterization sensors to determine as the blast head is moving the depth to which coatings must be removed, thereby improving production and minimizing waste. In phase II, the Contractor shall design and

  3. Vacuum polarization and Hawking radiation

    NASA Astrophysics Data System (ADS)

    Rahmati, Shohreh

    Quantum gravity is one of the interesting fields in contemporary physics which is still in progress. The purpose of quantum gravity is to present a quantum description for spacetime at 10-33cm or find the 'quanta' of gravitational interaction.. At present, the most viable theory to describe gravitational interaction is general relativity which is a classical theory. Semi-classical quantum gravity or quantum field theory in curved spacetime is an approximation to a full quantum theory of gravity. This approximation considers gravity as a classical field and matter fields are quantized. One interesting phenomena in semi-classical quantum gravity is Hawking radiation. Hawking radiation was derived by Stephen Hawking as a thermal emission of particles from the black hole horizon. In this thesis we obtain the spectrum of Hawking radiation using a new method. Vacuum is defined as the possible lowest energy state which is filled with pairs of virtual particle-antiparticle. Vacuum polarization is a consequence of pair creation in the presence of an external field such as an electromagnetic or gravitational field. Vacuum polarization in the vicinity of a black hole horizon can be interpreted as the cause of the emission from black holes known as Hawking radiation. In this thesis we try to obtain the Hawking spectrum using this approach. We re-examine vacuum polarization of a scalar field in a quasi-local volume that includes the horizon. We study the interaction of a scalar field with the background gravitational field of the black hole in the desired quasi-local region. The quasi-local volume is a hollow cylinder enclosed by two membranes, one inside the horizon and one outside the horizon. The net rate of particle emission can be obtained as the difference of the vacuum polarization from the outer boundary and inner boundary of the cylinder. Thus we found a new method to derive Hawking emission which is unitary and well defined in quantum field theory.

  4. Vacuum casting of thick polymeric films

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Moacanin, J.

    1979-01-01

    Bubble formation and layering, which often plague vacuum-evaporated films, are prevented by properly regulating process parameters. Vacuum casting may be applicable to forming thick films of other polymer/solvent solutions.

  5. Ceramic-to-metal vacuum seal

    NASA Technical Reports Server (NTRS)

    Sackerlotzky, O. H.

    1979-01-01

    Knife-edge sealing technique forms reliable, vacuum-tight bonds between materials having very different thermal-expansion characteristics. Seal is thin and flexible and absorb shear, hoop, and bonding stresses at joint so that seal remains vacuum tight.

  6. Rating of electrical wires in vacuum environments

    NASA Technical Reports Server (NTRS)

    Schaefer, J. L.; Svenson, F. C.

    1968-01-01

    Electric conductors used in vacuum environments have smaller cross sections. This report provides data on the correct size wire for a required current load in free-air, low-pressure oxygen, and vacuum environments.

  7. Materials for ultra-high vacuum

    SciTech Connect

    Lee, G.

    1989-08-15

    This report discusses materials for use in ultrahigh vacuum systems of 1 {times} 10{sup {minus}9} Torr or lower. The author briefly discusses alloys, solders, insulators and joining methods for vacuum systems. (JDL)

  8. Breakdown-Resistant RF Connectors for Vacuum

    NASA Technical Reports Server (NTRS)

    Caro, Edward R.; Bonazza, Walter J.

    1987-01-01

    Resilient inserts compensate for insulation shrinkage. Coaxial-cable connector for radio-frequency (RF) energy resists electrical breakdown in vacuum. Used on RF equipment in vacuum chambers as well as in spaceborne radar and communication gear.

  9. Switching Circuit for Shop Vacuum System

    NASA Technical Reports Server (NTRS)

    Burley, R. K.

    1987-01-01

    No internal connections to machine tools required. Switching circuit controls vacuum system draws debris from grinders and sanders in machine shop. Circuit automatically turns on vacuum system whenever at least one sander or grinder operating. Debris safely removed, even when operator neglects to turn on vacuum system manually. Pickup coils sense alternating magnetic fields just outside operating machines. Signal from any coil or combination of coils causes vacuum system to be turned on.

  10. A Review of Maintenance of Vacuum inside Vacuum Insulation Panels

    NASA Astrophysics Data System (ADS)

    Yang, Chun Guang; Xu, Lie

    The growing concerns over global energy crisis and the phasing out of polyurethane foams blown with CFC-11, which has high Ozone Depletion Potential(ODP), have pushed thermal insulation technology to improve its efficiency. Vacuum Insulation Panel(VIP) has been regarded as a super thermal insulation material with a thermal resistance of about 5-10 times higher than conventional thermal insulation. Appropriate vacuum in VIP is one of the most important factors contributing to the long term heat insulation performance of VIP. In this paper, the researches on three factors, which influence internal pressure inside VIP, including gas and water vapor permeation through the barrier, gas absorption by getters and desiccants and outgassing of the kernel, were reviewed respectively. Following this, the research emphasis and suggestions, which should be paid attention to, were summarized.

  11. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a.... (b) Each vacuum air system line and fitting on the discharge side of the pump that might contain...

  12. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes...

  13. 46 CFR 154.804 - Vacuum protection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Vacuum protection. 154.804 Section 154.804 Shipping... Systems § 154.804 Vacuum protection. (a) Except as allowed under paragraph (b) of this section, each cargo tank must have a vacuum protection system meeting paragraph (a)(1) of this section and either...

  14. Drying leather with vacuum and toggling sequentially

    USDA-ARS?s Scientific Manuscript database

    We investigated a drying method that will enable leather to be dried under vacuum and stretch sequentially to improve area yield. Vacuum drying offers fast speed at a low temperature, which would be advantageous to heat-vulnerable chrome-free leather. Adding a toggle action after vacuum drying cou...

  15. Utilize Vacuum Forming to Make Interdisciplinary Connections

    ERIC Educational Resources Information Center

    Love, Tyler S.; Valenza, Frank

    2011-01-01

    The concept of vacuum forming has been around since the 19th century, despite not being fully utilized in industry until the 1950s. In the past, industrial arts classes have used vacuum-forming projects to concentrate solely on the manufacturing process and the final product. However, vacuum forming is not just an old industrial arts activity; it…

  16. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Vacuum systems. 25.1433 Section 25.1433... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There... discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

  17. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Vacuum systems. 25.1433 Section 25.1433... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There... discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

  18. 46 CFR 154.804 - Vacuum protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Vacuum protection. 154.804 Section 154.804 Shipping... Systems § 154.804 Vacuum protection. (a) Except as allowed under paragraph (b) of this section, each cargo tank must have a vacuum protection system meeting paragraph (a)(1) of this section and either...

  19. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Vacuum systems. 25.1433 Section 25.1433... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There... discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

  20. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes...

  1. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes...

  2. 46 CFR 154.804 - Vacuum protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Vacuum protection. 154.804 Section 154.804 Shipping... Systems § 154.804 Vacuum protection. (a) Except as allowed under paragraph (b) of this section, each cargo tank must have a vacuum protection system meeting paragraph (a)(1) of this section and either...

  3. 14 CFR 29.1433 - Vacuum systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes...

  4. The APS beamline front end vacuum system

    SciTech Connect

    Nielsen, R.W.

    1993-10-15

    This report discusses the design of the vacuum system for the advanced photon source beamline front ends. Included in this report are discussions on: vacuum calculations, the differential pump; front end vacuum set points; cleaning methods and agents; and continuing and completed research and development.

  5. Ion pump provides increased vacuum pumping speed

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Multiple-cell ion pumps with increased vacuum pumping speed are used for producing ultrahigh vacuums in vacuum tubes and mass spectrometers. The pump has eight cathode-anode magnetron cells arranged in a cylinder which increase the surface area of the cathode.

  6. Utilize Vacuum Forming to Make Interdisciplinary Connections

    ERIC Educational Resources Information Center

    Love, Tyler S.; Valenza, Frank

    2011-01-01

    The concept of vacuum forming has been around since the 19th century, despite not being fully utilized in industry until the 1950s. In the past, industrial arts classes have used vacuum-forming projects to concentrate solely on the manufacturing process and the final product. However, vacuum forming is not just an old industrial arts activity; it…

  7. Open vacuum tube in space.

    PubMed

    Gonfalone, A A; Arends, H J

    1979-11-01

    After having reviewed briefly the reliability of vacuum tubes on spacecraft, it is shown that the operation in space of a vacuum tube with an open structure is possible provided adequate measures are taken. The tube considered here is a multielectrode electron gun emitting electrons into space, in order to control the potential of a satellite. To avoid the failure of the most sensitive element of the gun, namely the impregnated tungsten cathode, the gun design includes such characteristics as a slow warming up of the heater element, a reactivation program used in case of cathode contamination, and a clean opening system which is not contaminant. Similarities with communication tubes are considered and the advantages of open tubes are mentioned.

  8. In-vacuum exposure shutter

    DOEpatents

    Johnson, Terry A.; Replogle, William C.; Bernardez, Luis J.

    2004-06-01

    An in-vacuum radiation exposure shutter device can be employed to regulate a large footprint light beam. The shutter device includes (a) a source of radiation that generates an energy beam; (2) a shutter that includes (i) a frame defining an aperture toward which the energy beam is directed and (ii) a plurality of blades that are secured to the frame; and (3) device that rotates the shutter to cause the plurality of blades to intercept or allow the energy beam to travel through the aperture. Each blade can have a substantially planar surface and the plurality of blades are secured to the frame such that the planar surfaces of the plurality of blades are substantially parallel to each other. The shutter device is particularly suited for operation in a vacuum environment and can achieve shuttering speeds from about 0.1 second to 0.001 second or faster.

  9. Mirror fusion vacuum technology developments

    SciTech Connect

    Batzer, T.H.; Call, W.R.

    1983-11-21

    Magnetic Mirror Fusion experiments, such as MFTF-B+T (Mirror Fusion Test Facility-B, Tritium Upgrade) and foreseeable follow-on devices, have operational and maintenance requirements that have not yet been fully demonstrated. Among those associated with vacuum technology are the very-high continuous-pumping speeds, 10/sup 7/ to 10/sup 8/ l/s for D/sub 2/, T/sub 2/ and, to a lesser extent, He; the early detection of water leaks from the very-high heat-flux neutral-beam dumps and the detection and location of leaks in the superconducting magnets not protected by guard vacuums. Possible solutions to these problems have been identified and considerable progress has been made toward successfully demonstrating their feasibility.

  10. Radiation reaction in quantum vacuum

    NASA Astrophysics Data System (ADS)

    Seto, Keita

    2015-02-01

    Since the development of the radiating electron theory by P. A. M. Dirac in 1938 [P. A. M. Dirac, Proc. R. Soc. Lond. A 167, 148 (1938)], many authors have tried to reformulate this model, called the "radiation reaction". Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. In our recent research, we found a stabilized model of the radiation reaction in quantum vacuum [K. Seto et al., Prog. Theor. Exp. Phys. 2014, 043A01 (2014)]. It led us to an updated Fletcher-Millikan charge-to-mass ratio including radiation. In this paper, I will discuss the generalization of our previous model and the new equation of motion with the radiation reaction in quantum vacuum via photon-photon scatterings and also introduce the new tensor d{E}^{μ ν α β }/dm, as the anisotropy of the charge-to-mass ratio.

  11. Deflated--victims of vacuum.

    PubMed

    Sanders, Roy E

    2007-04-11

    Atmospheric pressure combined with a partial vacuum within chemical plant or refinery tanks can result in some ego-deflating moments. This article will review three catastrophic vessel failures in detail and touch on several other incidents. A 4000-gal acid tank was destroyed by a siphoning action; a well maintained tank truck was destroyed during a routine delivery; and a large, brand new refinery mega-vessel collapsed as the steam within it condensed. Seasoned engineers are aware of the frail nature of tanks and provide safeguards or procedures to limit damages. The purpose of this paper is to ensure this new generation of chemical plant/refinery employees understand the problems of the past and take the necessary precautions to guard against tank damages created by partial vacuum conditions.

  12. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    2001-08-31

    The Department of Energy (DOE) needs improved technologies to decontaminate large areas of both concrete and steel surfaces. The technology should have high operational efficiency, minimize exposures to workers, and produce low levels of secondary waste. In order to meet the DOE's needs, an applied research and development project for the improvement of a current decontamination technology, Vacuum Blasting, is proposed. The objective of this project is to improve the productivity and lower the expense of the existing vacuum blasting technology which has been widely used in DOE sites for removing radioactive contamination, PCBs, and lead-based paint. The proposed work would increase the productivity rate and provide safe and cost-effective decontamination of the DOE sites.

  13. Decoherence delays false vacuum decay

    NASA Astrophysics Data System (ADS)

    Bachlechner, Thomas C.

    2013-05-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling \\Gamma \\sim \\Gamma _{CDL}^{2}, where ΓCDL is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincaré recurrence in de Sitter space.

  14. Improved Vacuum-Tight Connector

    NASA Technical Reports Server (NTRS)

    Rudin, Frank

    1989-01-01

    Simple reinforcing tube increases service life and improves seal. Short stainless-steel tube inserted in copper tube to reinforce against compression, preventing leaks due to thermal distortion or to collapse under squeeze of ferrule in compressure fitting. Several test specimens of improved connector constructed, tested, and evaluated. Fittings not only operated successfully at required operating conditions of vacuum and temperature but also consistently demonstrated high reliability after loosened and tightened many times.

  15. Low-Cost "Vacuum Desiccator"

    NASA Astrophysics Data System (ADS)

    Sweet, Frederick

    2004-10-01

    Described are individualized, low-cost, and safe desiccators that can be efficiently and rapidly made with an inexpensive kitchen aid sold for shrink-wrapping food. The device can be used for enclosing small vials or bottles and also jars that are too large to be placed in conventional glass or plastic desiccators. This shrink-wrapping device is proposed for producing "vacuum desiccators" in large undergraduate chemistry laboratories or in graduate and research laboratories.

  16. 6 MV Vacuum Voltmeter Development

    DTIC Science & Technology

    2009-06-01

    reversed). The draw rod compresses o-ring seals between the insulators and rings to allow operation in vacuum. The insulator outer surfaces are coated...small-diameter ends, and have toroidal conductors attached at their large-diameter ends. The field shaper surfaces are treated to increase the...the direction to emit electrons toward the VVM insulator stack. The field magnitude is about 0.5 MV/cm, and would probably emit without the surface

  17. The solar vacuum water pump

    SciTech Connect

    Ryduchowski, K.W.

    1983-12-01

    In this paper the conception of the solar vacuum water pump is presented. The working medium of the pump consists of the water vapour with temperature about 100/sup 0/C, which is produced by solar energy Fresnel-lens collector. The pressure difference between the condensing chamber /3/ and ambient atmosphere caused by the direct condensation of the water vapour at the surface of the pumped water, creates the necessary pumping force.

  18. Cold cathode vacuum discharge tube

    DOEpatents

    Boettcher, Gordon E.

    1998-01-01

    A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging.

  19. Cold cathode vacuum discharge tube

    DOEpatents

    Boettcher, Gordon E.

    1998-01-01

    A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging.

  20. Random numbers from vacuum fluctuations

    NASA Astrophysics Data System (ADS)

    Shi, Yicheng; Chng, Brenda; Kurtsiefer, Christian

    2016-07-01

    We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

  1. Vacuum distillation of americium metal

    SciTech Connect

    Berry, J W; Knighton, J B; Nannie, C A

    1982-01-22

    High-purity americium metal has been distilled in multigram quantities from a plutonium-americium alloy. The procedure consisted of a two-stage vacuum distillation carried out at 1200/sup 0/C and 10/sup -6/ torr pressure. Four batches of americium metal were produced ranging in weight from 13.3 grams to 54.1 grams. The purity of the americium product ranged from 99.27 to 99.79%.

  2. Improved Vacuum-Tight Connector

    NASA Technical Reports Server (NTRS)

    Rudin, Frank

    1989-01-01

    Simple reinforcing tube increases service life and improves seal. Short stainless-steel tube inserted in copper tube to reinforce against compression, preventing leaks due to thermal distortion or to collapse under squeeze of ferrule in compressure fitting. Several test specimens of improved connector constructed, tested, and evaluated. Fittings not only operated successfully at required operating conditions of vacuum and temperature but also consistently demonstrated high reliability after loosened and tightened many times.

  3. Compound Walls For Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    Frazer, Robert E.

    1988-01-01

    Proposed compound-wall configuration enables construction of large high-vacuum chambers without having to use thick layers of expensive material to obtain necessary strength. Walls enclose chambers more than 1 m in diameter and several kilometers long. Compound wall made of strong outer layer of structural-steel culvert pipe welded to thin layer of high-quality, low-outgassing stainless steel.

  4. Random numbers from vacuum fluctuations

    SciTech Connect

    Shi, Yicheng; Kurtsiefer, Christian; Chng, Brenda

    2016-07-25

    We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

  5. Cosmic vacuum and galaxy formation

    NASA Astrophysics Data System (ADS)

    Chernin, A. D.

    2006-04-01

    It is demonstrated that the protogalactic perturbations must enter the nonlinear regime before the red shift z≈ 1; otherwise they would be destroyed by the antigravity of the vacuum dark energy at the subsequent epoch of the vacuum domination. At the zrrV={M/[(8π/3)ρV]}1/3, where M is the mass of a given over-density and ρV is the vacuum density. The criterion provides a new relation between the largest mass condensations and their spatial scales. All the real large-scale systems follow this relation definitely. It is also shown that a simple formula is possible for the key quantity in the theory of galaxy formation, namely the initial amplitude of the perturbation of the gravitational potential in the protogalactic structures. The amplitude is time independent and given in terms of the Friedmann integrals, which are genuine physical characteristics of the cosmic energies. The results suggest that there is a strong correspondence between the global design of the Universe as a whole and the cosmic structures of various masses and spatial scales.

  6. Improved Aerogel Vacuum Thermal Insulation

    NASA Technical Reports Server (NTRS)

    Ruemmele, Warren P.; Bue, Grant C.

    2009-01-01

    An improved design concept for aerogel vacuum thermal-insulation panels calls for multiple layers of aerogel sandwiched between layers of aluminized Mylar (or equivalent) poly(ethylene terephthalate), as depicted in the figure. This concept is applicable to both the rigid (brick) form and the flexible (blanket) form of aerogel vacuum thermal-insulation panels. Heretofore, the fabrication of a typical aerogel vacuum insulating panel has involved encapsulation of a single layer of aerogel in poly(ethylene terephthalate) and pumping of gases out of the aerogel-filled volume. A multilayer panel according to the improved design concept is fabricated in basically the same way: Multiple alternating layers of aerogel and aluminized poly(ethylene terephthalate) are assembled, then encapsulated in an outer layer of poly(ethylene terephthalate), and then the volume containing the multilayer structure is evacuated as in the single-layer case. The multilayer concept makes it possible to reduce effective thermal conductivity of a panel below that of a comparable single-layer panel, without adding weight or incurring other performance penalties. Implementation of the multilayer concept is simple and relatively inexpensive, involving only a few additional fabrication steps to assemble the multiple layers prior to evacuation. For a panel of the blanket type, the multilayer concept, affords the additional advantage of reduced stiffness.

  7. Running Jobs in the Vacuum

    NASA Astrophysics Data System (ADS)

    McNab, A.; Stagni, F.; Ubeda Garcia, M.

    2014-06-01

    We present a model for the operation of computing nodes at a site using Virtual Machines (VMs), in which VMs are created and contextualized for experiments by the site itself. For the experiment, these VMs appear to be produced spontaneously "in the vacuum" rather having to ask the site to create each one. This model takes advantage of the existing pilot job frameworks adopted by many experiments. In the Vacuum model, the contextualization process starts a job agent within the VM and real jobs are fetched from the central task queue as normal. An implementation of the Vacuum scheme, Vac, is presented in which a VM factory runs on each physical worker node to create and contextualize its set of VMs. With this system, each node's VM factory can decide which experiments' VMs to run, based on site-wide target shares and on a peer-to-peer protocol in which the site's VM factories query each other to discover which VM types they are running. A property of this system is that there is no gate keeper service, head node, or batch system accepting and then directing jobs to particular worker nodes, avoiding several central points of failure. Finally, we describe tests of the Vac system using jobs from the central LHCb task queue, using the same contextualization procedure for VMs developed by LHCb for Clouds.

  8. Matter, spacetime and the vacuum.

    PubMed

    Overduin, J; Fahr, H J

    2001-12-01

    We distinguish three historical and scientific views of matter, spacetime, and the relationship between them: the absolute approach of Newton, the relational approach most often associated with Mach, and a third, geometrical approach which inspired Einstein and continues to drive efforts toward a unified theory of fundamental interactions today. Which is correct? We suggest that this is, to a large extent, an "ill-posed question," reminiscent of the wave/particle debate in earlier times. The boundary between matter and spacetime is no longer easy to draw, and it is likely that they are complementary aspects of the same reality. There is no clearer illustration of this than the modern view of the vacuum. We review the importance of this concept in cosmology, and explore the extent to which the old idea of an "empty" vacuum might still be maintained. If the real cosmological vacuum is far from empty, as observations now suggest, then it may be possible to achieve an even simpler goal: a Universe with a net energy of zero.

  9. Vacuum-Packaging Technology for IRFPAs

    NASA Astrophysics Data System (ADS)

    Matsumura, Takeshi; Tokuda, Takayuki; Tsutinaga, Akinobu; Kimata, Masafumi; Abe, Hideyuki; Tokashiki, Naotaka

    We developed vacuum-packaging equipment and low-cost vacuum packaging technology for IRFPAs. The equipment is versatile and can process packages with various materials and structures. Getters are activated before vacuum packaging, and we can solder caps/ceramic-packages and caps/windows in a high-vacuum condition using this equipment. We also developed a micro-vacuum gauge to measure pressure in vacuum packages. The micro-vacuum gauge uses the principle of thermal conduction of gases. We use a multi-ceramic package that consists of six packages fabricated on a ceramic sheet, and confirm that the pressure in the processed packages is sufficiently low for high-performance IRFPA.

  10. Vacuum Technology and Standardization-An Update

    NASA Astrophysics Data System (ADS)

    Akram, H. M.; Rashid, H.

    2011-06-01

    Vacuum technology has been vital for the progress in almost every field of modern industrial & scientific research and technological developments. Research in this field is therefore important for the rapid progress in other sophisticated technologies. The modern society require precise know-how of vacuum metrology for its complex and sophisticated manufacturing processes and research activities. Accuracy in vacuum measurements is therefore an essential need for every application. The required accuracy is achieved with the help of well-calibrated vacuum gauges and this is possible only, if there exist proper vacuum standards of required range and accuracy. In this paper, a brief review of recently developed different vacuum standards, namely Standard Mercury Manometer, Standard Volume Expansion System and Standard Orifice Flow System will be presented, employed for the calibration of low, medium and high vacuum gauges respectively. Our recently developed standards are simple in design, least in vibration & degassing rate with desired accuracy, ease of operation and cost effective.

  11. Compactified Vacuum in Ten Dimensions.

    NASA Astrophysics Data System (ADS)

    Wurmser, Daniel

    1987-09-01

    Since the 1920's, theories which unify gravity with the other fundamental forces have called for more than the four observed dimensions of space-time. According to such a theory, the vacuum consists of flat four-dimensional space-time described by the Minkowski metric M ^4 and a "compactified" space B. The dimensions of B are small, and the space can only be observed at distance scales smaller than the present experimental limit. These theories have had serious difficulties. The equations of gravity severely restrict the possible choices for the space B. The allowed spaces are complicated and difficult to study. The vacuum is furthermore unstable in the sense that a small perturbation causes the compactified dimensions to expand indefinitely. There is an addition a semi-classical argument which implies that the compactified vacuum be annihilated by virtual black holes. It follows that a universe with compactified extra dimensions could not have survived to the present. These results were derived by applying the equations of general relativity to spaces of more than four dimensions. The form of these equations was assumed to be unchanged by an increase in the number of dimensions. Recently, it has been proposed that gravity in more than four dimensions may involve terms of higher order in the curvature as well as the linear terms present in ordinary general relativity. I illustrate the effect of such terms by considering the example B = S^6 where S ^6 is the six-dimensional sphere. Only when the extra terms are included is this choice of the compactified space allowed. I explore the effect of a small perturbation on such a vacuum. The ten-dimensional spherically symmetric potential is examined, and I determine conditions under which the formation of virtual black holes is forbidden. The example M^4 times S^6 is still plagued by the semi -classical instability, but this result does not hold in general. The requirement that virtual black holes be forbidden provides a

  12. High throughput vacuum chemical epitaxy

    NASA Astrophysics Data System (ADS)

    Fraas, L. M.; Malocsay, E.; Sundaram, V.; Baird, R. W.; Mao, B. Y.; Lee, G. Y.

    1990-10-01

    We have developed a vacuum chemical epitaxy (VCE) reactor which avoids the use of arsine and allows multiple wafers to be coated at one time. Our vacuum chemical epitaxy reactor closely resembles a molecular beam epitaxy system in that wafers are loaded into a stainless steel vacuum chamber through a load chamber. Also as in MBE, arsenic vapors are supplied as reactant by heating solid arsenic sources thereby avoiding the use of arsine. However, in our VCE reactor, a large number of wafers are coated at one time in a vacuum system by the substitution of Group III alkyl sources for the elemental metal sources traditionally used in MBE. Higher wafer throughput results because in VCE, the metal-alkyl sources for Ga, Al, and dopants can be mixed at room temperature and distributed uniformly though a large area injector to multiple substrates as a homogeneous array of mixed element molecular beams. The VCE reactor that we have built and that we shall describe here uniformly deposits films on 7 inch diameter substrate platters. Each platter contains seven two inch or three 3 inch diameter wafers. The load chamber contains up to nine platters. The vacuum chamber is equipped with two VCE growth zones and two arsenic ovens, one per growth zone. Finally, each oven has a 1 kg arsenic capacity. As of this writing, mirror smooth GaAs films have been grown at up to 4 μm/h growth rate on multiple wafers with good thickness uniformity. The background doping is p-type with a typical hole concentration and mobility of 1 × 10 16/cm 3 and 350 cm 2/V·s. This background doping level is low enough for the fabrication of MESFETs, solar cells, and photocathodes as well as other types of devices. We have fabricated MESFET devices using VCE-grown epi wafers with peak extrinsic transconductance as high as 210 mS/mm for a threshold voltage of - 3 V and a 0.6 μm gate length. We have also recently grown AlGaAs epi layers with up to 80% aluminum using TEAl as the aluminum alkyl source. The Al

  13. Advances in CIS devices fabricated by a non-vacuum technique

    SciTech Connect

    Leidholm, C.R.; Norsworthy, G.A.; Roe, R.; Halani, A.; Basol, B.M.; Kapur, V.K.

    1999-03-01

    A novel, non-vacuum technique based on nano-particle deposition has been developed for the formation of CIS-type solar cell absorbers. Solar cells with {gt}12{percent} efficiency were previously demonstrated using this technique. Improvements in module integration processes have recently yielded 8{percent} minimodules of 75 cm{sup 2} area. {copyright} {ital 1999 American Institute of Physics.}

  14. Running vacuum cosmological models: linear scalar perturbations

    NASA Astrophysics Data System (ADS)

    Perico, E. L. D.; Tamayo, D. A.

    2017-08-01

    In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Λ(H2) or Λ(R). Such models assume an equation of state for the vacuum given by bar PΛ = - bar rhoΛ, relating its background pressure bar PΛ with its mean energy density bar rhoΛ ≡ Λ/8πG. This equation of state suggests that the vacuum dynamics is due to an interaction with the matter content of the universe. Most of the approaches studying the observational impact of these models only consider the interaction between the vacuum and the transient dominant matter component of the universe. We extend such models by assuming that the running vacuum is the sum of independent contributions, namely bar rhoΛ = Σibar rhoΛi. Each Λ i vacuum component is associated and interacting with one of the i matter components in both the background and perturbation levels. We derive the evolution equations for the linear scalar vacuum and matter perturbations in those two scenarios, and identify the running vacuum imprints on the cosmic microwave background anisotropies as well as on the matter power spectrum. In the Λ(H2) scenario the vacuum is coupled with every matter component, whereas the Λ(R) description only leads to a coupling between vacuum and non-relativistic matter, producing different effects on the matter power spectrum.

  15. Case study: Vacuuming for VOCs

    SciTech Connect

    Das, A.; Mazowiecki, C.R.

    1996-06-01

    The soil-vapor extraction system, which draws VOC-laden vapors from the subsurface, has become a popular remediation tool. The soil-vapor extraction (SVE) system, also know as {open_quotes}venting,{close_quotes} has proven to be a popular and cost-effective choice to remediate sites contaminated with volatile organic compounds (VOCs) in the vadose zone. The SVE system includes airflow in the subsurface by applying a vacuum through extraction wells. The system is described in this article, with a report on performance monitoring included.

  16. Nature Abhors an Empty Vacuum,

    DTIC Science & Technology

    1981-08-01

    Schrodingers cat .) Perhaps it migt still be possible to approximate the standard view (in which "observations" replace mixed states by pure states) in...8217AD-A106 362 MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTE--ETC F/ S 20/10I NATURE ABHORS AN EMPTY VACUUM,(U) AUG Si M MINSKY N0001479’C-0260...COVERED S ŕ Nature Abhors an Empty Vacuumemorandum _ _ _ _ _A. PERFORMING ORG. REPORT NUMBER J. AUTHN0R(a) S .. CONTRACT onGRANT NUM0E .,- ’.A Marvin

  17. Wet/Dry Vacuum Cleaner

    NASA Technical Reports Server (NTRS)

    Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike

    1995-01-01

    Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

  18. Cold cathode vacuum discharge tube

    DOEpatents

    Boettcher, G.E.

    1998-03-10

    A cold cathode vacuum discharge tube, and method for making same, are disclosed with an interior surface of the trigger probe coated with carbon deposited by carbon vapor deposition (CVD) or diamond-like carbon (DLC) deposition. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 15 figs.

  19. Cold cathode vacuum discharge tube

    DOEpatents

    Boettcher, G.E.

    1998-04-14

    A cold cathode vacuum discharge tube, and method for making same, with an interior surface of the trigger probe coated with carbon deposited by chemical vapor deposition (CVD) or diamond-like carbon (DLC) deposition are disclosed. Preferably a solid graphite insert is employed in the probe-cathode structure in place of an aluminum bushing employed in the prior art. The CVD or DLC probe face is laser scribed to allow resistance trimming to match available trigger voltage signals and to reduce electrical aging. 14 figs.

  20. Ultra high vacuum seal arrangement

    DOEpatents

    Flaherty, Robert

    1981-01-01

    Arrangement for demountably sealing two concentric metallic tubes in an ultra high vacuum system which facilitates remote actuation. A tubular seal includes integral spaced lips which circumferentially engage the metallic tubes. The lips plastically deform the metallic tubes by mechanical forces resulting from a martensite to austenite transformation of the tubular seal upon application of a predetermined temperature. The sealing force is released upon application of another temperature which causes a transformation from the stronger austenite to the weaker martensite. Use of a dual acting sealing ring and driving ring circumferentially contacting the sealing ring is particularly applicable to sealing larger diameter concentric metallic members.

  1. Vacuum Decay via Lorentzian Wormholes

    NASA Astrophysics Data System (ADS)

    Rosales, J. L.

    We speculate about the space-time description due to the presence of Lorentzian worm-holes (handles in space-time joining two distant regions or other universes) in quantum gravity. The semiclassical rate of production of these Lorentzian wormholes in Reissner-Nordström space-times is calculated as a result of the spontaneous decay of vacuum due to a real tunneling configuration. In the magnetic case it only depends on the value of the field theoretical fine structure constant. We predict that the quantum probability corresponding to the nucleation of such geodesically complete space-times should be acutally negligible in our physical Universe.

  2. Laser-triggered vacuum switch

    DOEpatents

    Brannon, Paul J.; Cowgill, Donald F.

    1990-01-01

    A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable.

  3. Vacuum Friction in Rotating Particles

    SciTech Connect

    Manjavacas, A.; Garcia de Abajo, F. J.

    2010-09-10

    We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

  4. Extraordinary vacuum black string solutions

    SciTech Connect

    Kim, Hyeong-Chan; Lee, Jungjai

    2008-01-15

    In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.

  5. Robot design for a vacuum environment

    NASA Technical Reports Server (NTRS)

    Belinski, S.; Trento, W.; Imani-Shikhabadi, R.; Hackwood, S.

    1987-01-01

    The cleanliness requirements for many processing and manufacturing tasks are becoming ever stricter, resulting in a greater interest in the vacuum environment. Researchers discuss the importance of this special environment, and the development of robots which are physically and functionally suited to vacuum processing tasks. Work is in progress at the Center for robotic Systems in Microelectronics (CRSM) to provide a robot for the manufacture of a revolutionary new gyroscope in high vacuum. The need for vacuum in this and other processes is discussed as well as the requirements for a vacuum-compatible robot. Finally, researchers present details on work done at the CRSM to modify an existing clean-room compatible robot for use at high vacuum.

  6. Casimir Repulsion between Metallic Objects in Vacuum

    DTIC Science & Technology

    2010-08-27

    Casimir Repulsion between Metallic Objects in Vacuum Michael Levin,1 Alexander P. McCauley,2 Alejandro W. Rodriguez,2 M. T. Homer Reid,2 and Steven G...Received 19 March 2010; published 26 August 2010) We give an example of a geometry in which two metallic objects in vacuum experience a repulsive Casimir ...12.20.m Introduction.—The Casimir force between two parallel metal plates in vacuum is always attractive. A longstanding question is whether this is

  7. Advanced Photon Source accelerator ultrahigh vacuum guide

    SciTech Connect

    Liu, C.; Noonan, J.

    1994-03-01

    In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), booster synchrotron ring, storage ring, and insertion devices, and (3) cleaning procedures of ultrahigh vacuum (UHV) components presently used at APS.

  8. Invariant solutions for the static vacuum equation

    NASA Astrophysics Data System (ADS)

    Leandro, Benedito; Pina, Romildo

    2017-07-01

    We consider the static vacuum Einstein space-time when the spatial factor (or, base) is conformal to a pseudo-Euclidean space, which is invariant under the action of a translation group. We characterize all such solitons. Moreover, we give examples of static vacuum Einstein solutions for Einstein's field equation. Applications provide an explicit example of a complete static vacuum Einstein space-time.

  9. Foil Patches Seal Small Vacuum Leaks

    NASA Technical Reports Server (NTRS)

    Spiegel, Kirk W.; Reed, David W.

    1995-01-01

    Report discloses technique to patch holes in nickel-alloy rocket-engine nozzle parts prior to vacuum brazing. Technique involves lightly spot-welding nickel foil 0.002 in. thick over hole patched, then spot-welding corrosion-resistant steel foil of same thickness over nickel foil. Once patches subject to pressure and temperature of vacuum brazing, nickel foil diffuses to bond with nickel-alloy nozzle, making vacuum-tight seal.

  10. Foil Patches Seal Small Vacuum Leaks

    NASA Technical Reports Server (NTRS)

    Spiegel, Kirk W.; Reed, David W.

    1995-01-01

    Report discloses technique to patch holes in nickel-alloy rocket-engine nozzle parts prior to vacuum brazing. Technique involves lightly spot-welding nickel foil 0.002 in. thick over hole patched, then spot-welding corrosion-resistant steel foil of same thickness over nickel foil. Once patches subject to pressure and temperature of vacuum brazing, nickel foil diffuses to bond with nickel-alloy nozzle, making vacuum-tight seal.

  11. Soft Photon Effects on Vacuum Power Flow.

    DTIC Science & Technology

    1981-12-01

    Voltage as Function of Insulator Angle ............... 14 6. Vacuum Flashover Component Configuration ....................... 20 7. Radiation Temperature ...application. First, when an insulator is used in a vacuum , its ability to stand off voltage is severely limited on and near its surface . Bulk breakdown...investigate the following two problem areas inherent in vacuum nower flow under soft photon fluence: 1. Insulator Flashover : When a voltage is applied

  12. Polymer Lubricants For Use In Vacuum

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.

    1989-01-01

    Report describes tests of lubricating properties of 10 polymer-based materials - in particular, polyimides - in vacuum. Commercially available materials, in forms of solid bodies and films on metals, were tested on pin-on-disk apparatus in vacuum. Best low-wear, low-friction material was 80 PMDA/20 BTDA solid-body polyimide. Friction and wear properties of most polyimides so good in vacuum that solid-lubricant additives not necessary.

  13. Vacuum Attachment for XRF Scanner

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    Vacuum apparatuses have been developed for increasing the range of elements that can be identified by use of x-ray fluorescent (XRF) scanners of the type mentioned in the two immediately preceding articles. As a consequence of the underlying physical principles, in the presence of air, such an XRF scanner is limited to analysis of chlorine and elements of greater atomic number. When the XRF scanner is operated in a vacuum, it extends the range of analysis to lower atomic numbers - even as far as aluminum and sodium. Hence, more elements will be available for use in XRF labeling of objects as discussed in the two preceding articles. The added benefits of the extended capabilities also have other uses for NASA. Detection of elements of low atomic number is of high interest to the aerospace community. High-strength aluminum alloys will be easily analyzed for composition. Silicon, a major contaminant in certain processes, will be detectable before the process is begun, possibly eliminating weld or adhesion problems. Exotic alloys will be evaluated for composition prior to being placed in service where lives depend on them. And in the less glamorous applications, such as bolts and fasteners, substandard products and counterfeit items will be evaluated at the receiving function and never allowed to enter the operation

  14. Vacuum Technology Considerations For Mass Metrology

    PubMed Central

    Abbott, Patrick J.; Jabour, Zeina J.

    2011-01-01

    Vacuum weighing of mass artifacts eliminates the necessity of air buoyancy correction and its contribution to the measurement uncertainty. Vacuum weighing is also an important process in the experiments currently underway for the redefinition of the SI mass unit, the kilogram. Creating the optimum vacuum environment for mass metrology requires careful design and selection of construction materials, plumbing components, pumping, and pressure gauging technologies. We review the vacuum technology1 required for mass metrology and suggest procedures and hardware for successful and reproducible operation. PMID:26989593

  15. Electrical Strength of Multilayer Vacuum Insulators

    SciTech Connect

    Harris, J R; Kendig, M; Poole, B; Sanders, D M; Caporaso, G J

    2008-07-01

    The electrical strength of vacuum insulators is a key constraint in the design of particle accelerators and pulsed power systems. Vacuum insulating structures assembled from alternating layers of metal and dielectric can result in improved performance compared to conventional insulators, but previous attempts to optimize their design have yielded seemingly inconsistent results. Here, we present two models for the electrical strength of these structures, one assuming failure by vacuum arcing between adjacent metal layers and the other assuming failure by vacuum surface flashover. These models predict scaling laws which are in agreement with the experimental data currently available.

  16. Cold vacuum drying facility design requirements

    SciTech Connect

    IRWIN, J.J.

    1999-07-01

    This document provides the detailed design requirements for the Spent Nuclear Fuel Project Cold Vacuum Drying Facility. Process, safety, and quality assurance requirements and interfaces are specified.

  17. Test stand system for vacuum chambers

    NASA Technical Reports Server (NTRS)

    Newman, D. F. (Inventor)

    1973-01-01

    A test stand system for supporting test items in a vacuum chamber is described. The system consists of a frame adapted to conform to the inside of the vacuum chamber and supporting a central vertical shaft. The shaft rotates on bearings located at each end of the shaft. Several vertically spaced plates which fixed to the vertical shaft may be adjusted for height to support the test equipment as required. The test equipment may be rotated during tests without disturbing the vacuum by a manually actuated drive external to the vacuum chamber.

  18. APS Storage Ring vacuum chamber fabrication

    SciTech Connect

    Goeppner, G.A.

    1990-01-01

    The 1104-m circumference Advanced Photon Source Storage Ring Vacuum System is composed of 240 individual sections, which are fabricated from a combination of aluminum extrusions and machined components. The vacuum chambers will have 3800 weld joints, each subject to strict vacuum requirements, as well as a variety of related design criteria. The vacuum criteria and chamber design are reviewed, including a discussion of the weld joint geometries. The critical fabrication process parameters for meeting the design requirements are discussed. The experiences of the prototype chamber fabrication program are presented. Finally, the required facilities preparation for construction activity is briefly described. 6 refs., 6 figs., 1 tab.

  19. LCLS XTOD Tunnel Vacuum System (XVTS)

    SciTech Connect

    Beale, R; Duffy, P; Kishiyama, K; Mckernan, M; McMahon, D; Lewis, S; Trent, J; Tung, L; Shen, S

    2005-11-04

    The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.

  20. Attractor Explosions and Catalyzed Vacuum Decay

    SciTech Connect

    Green, Daniel; Silverstein, Eva; Starr, David

    2006-05-05

    We present a mechanism for catalyzed vacuum bubble production obtained by combining moduli stabilization with a generalized attractor phenomenon in which moduli are sourced by compact objects. This leads straightforwardly to a class of examples in which the Hawking decay process for black holes unveils a bubble of a different vacuum from the ambient one, generalizing the new endpoint for Hawking evaporation discovered recently by Horowitz. Catalyzed vacuum bubble production can occur for both charged and uncharged bodies, including Schwarzschild black holes for which massive particles produced in the Hawking process can trigger vacuum decay. We briefly discuss applications of this process to the population and stability of metastable vacua.

  1. Feasibility assessment of vacuum cooling followed by immersion vacuum cooling on water-cooked pork.

    PubMed

    Dong, Xiaoguang; Chen, Hui; Liu, Yi; Dai, Ruitong; Li, Xingmin

    2012-01-01

    Vacuum cooling followed by immersion vacuum cooling was designed to cool water-cooked pork (1.5±0.05 kg) compared with air blast cooling (4±0.5°C, 2 m/s), vacuum cooling (10 mbar) and immersion vacuum cooling. This combined cooling method was: vacuum cooling to an intermediate temperature of 25°C and then immersion vacuum cooling with water of 10°C to the final temperature of 10°C. It was found that the cooling loss of this combined cooling method was significantly lower (P<0.05) than those of air blast cooling and vacuum cooling. This combined cooling was faster (P<0.05) than air blast cooling and immersion vacuum cooling in terms of cooling rate. Moreover, the pork cooled by combined cooling method had significant differences (P<0.05) in water content, color and shear force.

  2. Advanced light source vacuum policy and vacuum guidelines for beamlines and experiment endstations

    SciTech Connect

    Hussain, Z.

    1995-08-01

    The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third generation synchrotron radiation source whose beam lifetime depends on the quality of the vacuum in the storage ring and the connecting beamlines. The storage ring and most of the beamlines share a common vacuum and are operated under ultra-high-vacuum (UHV) conditions. All endstations and beamline equipment must be operated so as to avoid contamination of beamline components, and must include proper safeguards to protect the storage ring vacuum from an accidental break in the beamline or endstation vacuum systems. The primary gas load during operation is due to thermal desorption and electron/photon induced desorption of contaminants from the interior of the vacuum vessel and its components. The desorption rates are considerably higher for hydrocarbon contamination, thus considerable emphasis is placed on eliminating these sources of contaminants. All vacuum components in a beamline and endstation must meet the ALS vacuum specifications. The vacuum design of both beamlines and endstations must be approved by the ALS Beamline Review Committee (BRC) before vacuum connections to the storage ring are made. The vacuum design is first checked during the Beamline Design Review (BDR) held before construction of the beamline equipment begins. Any deviation from the ALS vacuum specifications must be approved by the BRC prior to installation of the equipment on the ALS floor. Any modification that is incorporated into a vacuum assembly without the written approval of the BRC is done at the user`s risk and may lead to rejection of the whole assembly.

  3. Gravitational correction to vacuum polarization

    NASA Astrophysics Data System (ADS)

    Jentschura, U. D.

    2015-02-01

    We consider the gravitational correction to (electronic) vacuum polarization in the presence of a gravitational background field. The Dirac propagators for the virtual fermions are modified to include the leading gravitational correction (potential term) which corresponds to a coordinate-dependent fermion mass. The mass term is assumed to be uniform over a length scale commensurate with the virtual electron-positron pair. The on-mass shell renormalization condition ensures that the gravitational correction vanishes on the mass shell of the photon, i.e., the speed of light is unaffected by the quantum field theoretical loop correction, in full agreement with the equivalence principle. Nontrivial corrections are obtained for off-shell, virtual photons. We compare our findings to other works on generalized Lorentz transformations and combined quantum-electrodynamic gravitational corrections to the speed of light which have recently appeared in the literature.

  4. TRIUMF cyclotron vacuum system refurbishing

    NASA Astrophysics Data System (ADS)

    Sekachev, I.

    2008-03-01

    The cyclotron at TRIUMF was commissioned to full energy in 1974. The volume of the cyclotron vacuum tank is about 100 m3 and it operates at 5×10-8 Torr pressure during beam production. The pumping is mainly based on a Phillips B-20 cryogenerator (Stirling cycle 4-cylinder engine). The cryogenerator supplies helium gas at 16 K and 70 K to cryopanels in the tank. The decreasing reliability of the B-20 and demanding maintenance requirements triggered the decision to completely overhaul or replace the cryogenerator. Replacement with the LINDE-1630 helium refrigerator was found to be the most attractive (technically and economically) option. The details of the proposal with installation of the helium refrigerator and with a continuous flow liquid nitrogen shield cooling system are presented.

  5. Laser sealed vacuum insulation window

    DOEpatents

    Benson, David K.; Tracy, C. Edwin

    1987-01-01

    A laser sealed evacuated window panel is comprised of two glass panes held spaced apart in relation to each other by a plurality of spherical glass beads and glass welded around the edges to provide an evacuated space between the glass panes that is completely glass sealed from the exterior. The glass welded edge seal is obtained by welding the edges of the glass panes together with a laser beam while the glass panes and bead spacers are positioned in a vacuum furnace and heated to the annealing point of the glass to avoid stress fracture in the area of the glass weld. The laser welding in the furnace can be directed around the perimeter of the glass panel by a combination of rotating the glass panel and linearly translating or aiming the laser with a relay mirror.

  6. Repetitively pulsed vacuum insulator flashover

    SciTech Connect

    Ginn, J.W.; Buttram, M.T.

    1987-01-01

    Experiments were performed to determine the flashover strength of various vacuum insulators under conditions of repetitive pulsing. The pulse duration was 30 ns, and the thickness of a typical insulator sample was 1.8 cm. Data were taken for 45 insulators from five different materials. An insulator was subjected to an extended series of pulses at a given repetition rate and field. If flashover was not detected, the field level was increased and the sequence repeated. At rates up to 50 pulses per second, there was no apparent dependence of flashover field on rate. In addition, some ''single shot'' data were taken, including various modifications of the geometries and surface textures of the insulators. Only two to the modifications increased the flashover strength significantly over that of a 45 sample: (1) annealing some plastics (roughly a 35% increase), and (2) extending the insulator to cover the surfaces of both electrodes (an increase of nearly a factor of two).

  7. Vacuum Plasma Sprayed Metallic Coatings

    NASA Astrophysics Data System (ADS)

    Shankar, S.; Koenig, D. E.; Dardi, L. E.

    1981-10-01

    Recognizing the fundamental cost advantage, technical capabilities, and compositional flexibility of reduced pressure (vacuum) plasma spraying compared to other overlay coating methods, an advanced, second generation, closed chamber deposition process called VPX (a Howmet trademark) was developed. An automated experimental facility for coating gas turbine engine components was also constructed. This paper describes several important features of the process and equipment. It shows that the use of optimized spray parameters combined with an appropriate schedule of relative orientations between the gun and work-piece can be used to produce dense and highly reproducible coatings of either uniform or controlled thickness distributions. The chemical composition, microstructure, and interfacial characteristics of typical MCrAlY coatings are reported. Some effects of operating procedures and MCrAlY chemical composition on coating density are noted. The results of mechanical property and burner rig tests of coated material are also described.

  8. Laser sealed vacuum insulating window

    DOEpatents

    Benson, D.K.; Tracy, C.E.

    1985-08-19

    A laser sealed evacuated window panel is comprised of two glass panes held spaced apart in relation to each other by a plurality of spherical glass beads and glass welded around the edges to provide an evacuated space between the glass panes that is completely glass sealed from the exterior. The glass welded edge seal is obtained by welding the edges of the glass panes together with a laser beam while the glass panes and bead spacers are positioned in a vacuum furnace and heated to the annealing point of the glass to avoid stress fracture in the area of the glass weld. The laser welding in the furnace can be directed around the perimeter of the galss panel by a combination of rotating the glass panel and linearly translating or aiming the laser with a relay mirror.

  9. Sugar maple sap volume increases as vacuum level is increased

    Treesearch

    Russell S. Walters; H. Clay Smith

    1975-01-01

    Maple sap yields collected by using plastic tubing with a vacuum pump increased as the vacuum level was increased. Sap volumes collected at the 10- and 15-inch mercury vacuum levels were statistically significantly higher than volumes collected at the 5-inch level. Although the 15-inch vacuum yielded more sap than the 10-inch vacuum, the difference was not...

  10. Variations in vacuum gap location in a microsecond plasma opening switch

    SciTech Connect

    Lisitsyn, I.V.; Kohno, S.; Kawauchi, T.; Akiyama, H.

    1997-10-01

    The process of vacuum gap formation in a microsecond plasma opening switch has been studied using a He{endash}Ne laser interferometer. Time and spatially resolved density measurements are performed in the plasma opening switch, showing a density decrease during switch opening in almost the whole interelectrode gap. Despite fine triggering accuracy and generally good shot-to-shot reproducibility of voltage and current waveforms, measurements made with the same laser beam location indicated remarkable shot-to-shot variation. The unstable formation of the vacuum gap in the microsecond plasma opening switch may be a major limiting factor for efficient switch operation. {copyright} {ital 1997 American Institute of Physics.}

  11. Bakeable, all-metal demountable vacuum seal to a flat glass surface

    NASA Astrophysics Data System (ADS)

    Ng, N.; Collins, R. E.; Lenzen, M.

    2002-07-01

    A technique is described for making a demountable vacuum seal of reasonably good quality between an all-metal evacuation cup and a flat glass surface. The seal is bakeable to temperatures close to the softening point of glass. The stainless steel evacuation cup has two concentric and coplanar sealing surfaces. The regions defined by these surfaces are differentially pumped. Pressures typically below 1 Torr are achieved in the annular space between the two sealing surfaces using a conventional rotary pump. The center region inside the inner sealing surface is typically evacuated to below 10-4 Torr using conventional diffusion or turbomolecular pumps. copyright 2002 American Vacuum Society.

  12. Global three-neutrino vacuum oscillation fits to the solar and atmospheric anomalies

    SciTech Connect

    Barger, V. |; Whisnant, K.

    1999-05-01

    We determine the three-neutrino mixing and mass parameters that are allowed by the solar and atmospheric neutrino data when vacuum oscillations are responsible for both phenomena. The global fit does not appreciably change the allowed regions for the parameters obtained from effective two-neutrino fits. We discuss how measurements of the solar electron energy spectrum below 6.5 GeV in Super-Kamiokande and seasonal variations in the Super-Kamiokande, {sup 71}Ga, and BOREXINO experiments can distinguish the different solar vacuum solutions. {copyright} {ital 1999} {ital The American Physical Society}

  13. Elastic vacuum seal for cryogenic temperatures

    SciTech Connect

    Kolenko, E.A.

    1988-06-01

    Cold-hardened silicone rubber is proposed as a vacuum seal in units that contain materials with vastly different expansion coefficients and which operate at cryogenic temperatures. The cold vulcanization process and the polymerization catalyst used to accelerate and stabilize the process are described. Test results obtained for vacuum tightness in liquid nitrogen are assessed.

  14. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Vacuum systems. 25.1433 Section 25.1433 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There...

  15. Decoherence of quantum states in QCD vacuum

    NASA Astrophysics Data System (ADS)

    Kuvshinov, V.; Bagashov, E.

    2017-09-01

    The stochastic vacuum of quantum chromodynamics is used as an environment for quarks considered as color state vectors. It is shown that during interaction with the stochastic vacuum information of the quark color state is lost with time (decoherence of the quark state vector occurs), which effectively means that it is impossible to observe the quark as a free color particle (confinement).

  16. False vacuum as an unstable state

    NASA Astrophysics Data System (ADS)

    Urbanowski, K.

    2016-11-01

    Calculations performed within the Standard Model suggest that the electroweak vacuum is unstable if MH < 126 GeV, (MH is the mass of the Higgs particle). LHC discovery of the Higgs boson indicates that MH ≃ 125 GeV. So the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory. At asymptotically late times the survival probability as a function of time t has an inverse power-like form. We show that at this time region the energy of the false vacuum states tends to the energy of the true vacuum state as 1/t2 for t → ∞. This means that the energy density in the unstable vacuum state should have analogous properties and hence the cosmological constant Λ = Λ(t) too. So Λ in the Universe with the unstable vacuum should have a form of the sum of the "bare" cosmological constant and of the term of a type 1/t^2:Λ (t) ≡ Λbare + d/t^2, (where Λbare is the cosmological constant for the Universe with the true vacuum).

  17. Use of vacuum residue in thermal cracking

    SciTech Connect

    Mikulla, K.D.; Wernicke, H.J.

    1981-03-24

    Vacuum residue is used for production of olefins by first separating, preferably by solvent extraction, the asphalt therein , blending resultant asphalt depleted fraction with a lighter fraction, E.G., a vacuum gas oil, and then subjecting the blend to a conventional catalytic hydrogenation step prior to thermal cracking. The hydrogenate may be separated into fractions with the heavy fraction only being thermally cracked.

  18. Nonperturbative vacuum and hard scattering processes

    SciTech Connect

    Sakai, N.

    1980-08-01

    A number of interesting suggestions for the QCD nonperturbative vacuum have been advocated in recent years by a group of people in Copenhagen. Some of the main ideas are briefly reviewed. An attempt to obtain the physical effects of the nonperturbative vacuum by studying hard scattering processes such as e/sup +/e/sup -/ ..-->.. hadrons is also described. 2 figures.

  19. Intelligent control of vacuum aluminum brazing

    SciTech Connect

    Zhong, G.; Pai, D.M.; Badgley, S.

    1995-06-01

    Vacuum brazing is a versatile modern day metal joining method. It usually includes vacuum producing, heating and residual gas analyzing systems. When used to join aluminum parts, the quality of the brazed joint is highly dependent on the residual gases in the vacuum, especially the residual oxygen and water vapor in the vacuum chamber which affect the formation of oxides. These vacuum environment brazing contaminants are reduced during the out-gassing processes of degassing and desorption during heating under vacuum. Exceeding the boundary limits of these contaminants causes unacceptable flow of braze filler in the joints during the brazing process. Identification of the quality control boundary for vacuum brazing of aluminum alloy makes computer control of vacuum brazing quality for aluminum alloys possible. The present study utilizes a residual gas analyzer (RGA) to monitor the partial pressures of residual gases during brazing. These data are transported to computer through the RS-232 interface port on the RGA, and used in real time to monitor the brazing quality by an algorithm based on the quality control boundary. If the quality is bad, the computer will send a ``hold`` signal to the heating system via another Rs-232 port until the environment is reestablished within the acceptable boundary.

  20. 46 CFR 154.804 - Vacuum protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Systems § 154.804 Vacuum protection. (a) Except as allowed under paragraph (b) of this section, each cargo tank must have a vacuum protection system meeting paragraph (a)(1) of this section and either paragraph (a)(2) or (a)(3) of this section. (1) There must be a means of testing the operation of the system...

  1. 14 CFR 25.1433 - Vacuum systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vacuum systems. 25.1433 Section 25.1433... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There must be means, in addition to the normal pressure relief, to automatically relieve the pressure in the...

  2. Vacuum deposition and curing of liquid monomers

    DOEpatents

    Affinito, John D.

    1993-01-01

    The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of "standard" polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

  3. Vacuum deposition and curing of liquid monomers

    DOEpatents

    Affinito, John D.

    1995-01-01

    The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of "standard" polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal or oxide may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

  4. Vacuum deposition and curing of liquid monomers

    DOEpatents

    Affinito, J.D.

    1993-11-09

    The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of standard polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

  5. Maxwell electrodynamics subjected to quantum vacuum fluctuations

    SciTech Connect

    Gevorkyan, A. S.; Gevorkyan, A. A.

    2011-06-15

    The propagation of electromagnetic waves in the vacuum is considered taking into account quantum fluctuations in the limits of Maxwell-Langevin (ML) equations. For a model of 'white noise' fluctuations, using ML equations, a second order partial differential equation is found which describes the quantum distribution of virtual particles in vacuum. It is proved that in order to satisfy observed facts, the Lamb Shift etc, the virtual particles should be quantized in unperturbed vacuum. It is shown that the quantized virtual particles in toto (approximately 86 percent) are condensed on the 'ground state' energy level. It is proved that the extension of Maxwell electrodynamics with inclusion of the vacuum quantum field fluctuations may be constructed on a 6D space-time continuum with a 2D compactified subspace. Their influence on the refraction indexes of vacuum is studied.

  6. A new vacuum for loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Dittrich, Bianca; Geiller, Marc

    2015-06-01

    We construct a new vacuum and representation for loop quantum gravity. Because the new vacuum is based on BF theory, it is physical for (2+1)-dimensional gravity, and much closer to the spirit of spin foam quantization in general. To construct this new vacuum and the associated representation of quantum observables, we introduce a modified holonomy-flux algebra that is cylindrically consistent with respect to the notion of refinement by time evolution suggested in Dittrich and Steinhaus (2013 arXiv:1311.7565). This supports the proposal for a construction of the physical vacuum made in Dittrich and Steinhaus (2013 arXiv:1311.7565) and Dittrich (2012 New J. Phys. 14 123004), and for (3+1)-dimensional gravity. We expect that the vacuum introduced here will facilitate the extraction of large scale physics and cosmological predictions from loop quantum gravity.

  7. Vacuum deposition and curing of liquid monomers

    DOEpatents

    Affinito, J.D.

    1995-03-07

    The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of ``standard`` polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal or oxide may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

  8. [Ambulant treatment of wounds by vacuum sealing].

    PubMed

    Ziegler, U E; Schmidt, K; Breithaupt, B; Menig, R; Debus, E S; Thiede, A

    2000-01-01

    The treatment of chronic wounds by vacuum sealing as an outpatient procedure is a new method of wound conditioning before closing the defect. The quality of life for the patient in his usual surrounding is maintained. Financial aspects also play a role in this treatment since costs for the health care system can be reduced. Various vacuum pumps, drainages and polymere foams are available and suitable for the outpatient treatment. The most important condition is to regularly check the vacuum. This can performed by the patient, the relatives or nursing staff. The main complication consists in loss of vacuum but technical and local or systemic complications can also appear. Individually applied vacuum dressings (polyvinyl foam, drainage tube and polymere foil) are practical. The ideal pump systems for the outpatient treatment are still not trial.

  9. Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters

    NASA Astrophysics Data System (ADS)

    Cheng, Shaoyong; Xiu, Shixin; Wang, Jimei; Shen, Zhengchao

    2006-11-01

    The greenhouse effect of SF6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.

  10. Electroweak vacuum instability and renormalized Higgs field vacuum fluctuations in the inflationary universe

    NASA Astrophysics Data System (ADS)

    Kohri, Kazunori; Matsui, Hiroki

    2017-08-01

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations < δ phi 2 > enlarge in proportion to the Hubble scale H2. Therefore, the large inflationary vacuum fluctuations of the Higgs field < δ phi 2 > are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations < δ phi 2 >, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field phi determined by the effective potential V eff( phi ) in curved space-time and the renormalized vacuum fluctuations < δ phi 2 >ren via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling ξ(μ). In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field phi, or the formations of AdS domains or bubbles unless the Hubble scale is small enough H< ΛI .

  11. American Women and American Studies.

    ERIC Educational Resources Information Center

    Chmaj, Betty E.

    The American Studies Association (ASA) is an interprofessional group, representing a cross-section of persons from American literature, American history, the social sciences, philosophy, archeology, Black Studies, Urban Studies, American Studies, and others. This document by the ASA Commission on the Status of Women includes: (1) a report of the…

  12. Wireless Integrated Microelectronic Vacuum Sensor System

    NASA Technical Reports Server (NTRS)

    Krug, Eric; Philpot, Brian; Trott, Aaron; Lawrence, Shaun

    2013-01-01

    NASA Stennis Space Center's (SSC's) large rocket engine test facility requires the use of liquid propellants, including the use of cryogenic fluids like liquid hydrogen as fuel, and liquid oxygen as an oxidizer (gases which have been liquefied at very low temperatures). These fluids require special handling, storage, and transfer technology. The biggest problem associated with transferring cryogenic liquids is product loss due to heat transfer. Vacuum jacketed piping is specifically designed to maintain high thermal efficiency so that cryogenic liquids can be transferred with minimal heat transfer. A vacuum jacketed pipe is essentially two pipes in one. There is an inner carrier pipe, in which the cryogenic liquid is actually transferred, and an outer jacket pipe that supports and seals the vacuum insulation, forming the "vacuum jacket." The integrity of the vacuum jacketed transmission lines that transfer the cryogenic fluid from delivery barges to the test stand must be maintained prior to and during engine testing. To monitor the vacuum in these vacuum jacketed transmission lines, vacuum gauge readings are used. At SSC, vacuum gauge measurements are done on a manual rotation basis with two technicians, each using a handheld instrument. Manual collection of vacuum data is labor intensive and uses valuable personnel time. Additionally, there are times when personnel cannot collect the data in a timely fashion (i.e., when a leak is detected, measurements must be taken more often). Additionally, distribution of this data to all interested parties can be cumbersome. To simplify the vacuum-gauge data collection process, automate the data collection, and decrease the labor costs associated with acquiring these measurements, an automated system that monitors the existing gauges was developed by Invocon, Inc. For this project, Invocon developed a Wireless Integrated Microelectronic Vacuum Sensor System (WIMVSS) that provides the ability to gather vacuum

  13. Apparatus For Metal/Inert-Gas Welding In Vacuum

    NASA Technical Reports Server (NTRS)

    Stocks, C. O.

    1994-01-01

    Metal/inert-gas welding-torch assembly operates in vacuum. Plasma generated in interior chamber and focused onto workpiece in vacuum. Pinch rollers feed wire to weld puddle. Controlled flow of plasma reduces dispersal in vacuum, preventing extinction.

  14. Vacuum transitions and eternal inflation

    NASA Astrophysics Data System (ADS)

    Johnson, Matthew C.

    In this thesis, we focus on aspects of inflation and eternal inflation arising in scalar field theories coupled to gravity which possess a number of metastable states. Such theories contain instantons that interpolate between the metastable potential minima, corresponding to the nucleation of bubbles containing a new phase in a background of the old phase. In the first part of this thesis, we describe the classical dynamics and quantum nucleation of vacuum bubbles. We classify all possible spherically symmetric, thin-wall solutions with arbitrary interior and exterior cosmological constant, and find that bubbles possessing a turning point are unstable to aspherical perturbations. Next, we turn to the quantum nucleation of bubbles with zero mass. Focusing on instantons interpolating between positive and negative energy minima, we find that there exists a "Great Divide" in the space of potentials, across which the lifetime of metastable states differs drastically. Generalizing a semi-classical Hamiltonian formalism to treat the nucleation of bubbles with nonzero mass, we show that a number of tunneling mechanisms can be unified in the thin-wall limit, and directly compare their probabilities. In the second part of this thesis, we discuss the measure problem in eternal inflation. We give a detailed analysis of the prospects for making predictions in eternal inflation, and describe the existing probability measures and the connections between them. We then show that all existing measures exhibit a number of rather generic phenomena, for example strongly weighting vacua that can undergo rapid transitions between each other. It is argued that making predictions will require a measure that weights histories as opposed to vacua, and we develop a formalism to addresses this. Finally, we assess the prospects for observing collisions between vacuum bubbles in an eternally inflating universe. Contrary to conventional wisdom, we find that under certain assumptions most

  15. Dynamics of false vacuum bubbles with nonminimal coupling

    SciTech Connect

    Lee, Bum-Hoon; Lee, Chul H.; Lee, Wonwoo; Nam, Siyoung; Park, Chanyong

    2008-03-15

    We study the dynamics of false vacuum bubbles. A nonminimally coupled scalar field gives rise to the effect of negative tension. The mass of a false vacuum bubble from an outside observer's point of view can be positive, zero, or negative. The interior false vacuum has de Sitter geometry, while the exterior true vacuum background can have geometry depending on the vacuum energy. We show that there exist expanding false vacuum bubbles without the initial singularity in the past.

  16. O.H. Module Vacuum Lifting Fixture

    SciTech Connect

    McGivern, Paul; /Fermilab

    1987-12-31

    In order to move the 800 lb. copper plates that make up the O.H. modules a vacuum lifting device has been made that will lift the plates safely. The purpose of this report is to provide documentation for the structural integrity of the system and to make sure that it passes all of the safety requirements that have been established for a system of this nature. The vacuum system is composed of a PIAB model M125 vacuum pump that has the pumping capacity of 27 in. Hg. This pump will produce vacuum for three 8 1/2 in. diameter suction cups or pads. A pressure gauge is fixed on the unit to allow the operator to continually monitor the pressure during all lifts. An additional safety feature is a mechanical vacuum monitoring device that is set to emit a shrill tone if the system vacuum falls below 24 in. Hg. A 'bleed' valve fixed on the unit will be used to let the system go to atmospheric pressure once the lift is complete. A 3 psi. check valve and a vacuum reserve of 384 in. is used to insure that the device will not just drop the object if the pump fails. A schematic for the pumping system is given in Figure 1.

  17. Medium-Assisted Vacuum Force

    NASA Astrophysics Data System (ADS)

    Tomaš, M. S.

    We discuss some implications of a very recently obtained result for the force on a slab in a planar cavity based on the calculation of the vacuum Lorentz force [C.Raabe and D.-G. Welsch, Phys. Rev. A 71 (2005) 013814]. We demonstrate that, according to this formula, the total force on the slab consists of a medium-screened Casimir force and, in addition to it, a medium-assisted force. The sign of of the medium-assisted force is determined solely by the properties of the cavity mirrors. In the Lifshitz configuration, this force is proportional to 1/d at small distances and is very small compared with the corresponding van der Waals force. At large distances, however, it is proportional to 1/d4 and comparable with the Casimir force, especially for denser media. The exponents in these power laws decrease by 1 in the case of a thin slab. The formula for the medium-assisted force also describes the force on a layer of the cavity medium, which has similar properties. For dilute media, it implies an atom-mirror interaction of the Coulomb type at small and of the Casimir-Polder type at large atom-mirror distances. For a perfectly reflecting mirror, the latter force is effectively only three-times smaller than the Casimir-Polder force.

  18. Vacuum brazing beryllium to Monel

    SciTech Connect

    Glenn, T.G.; Grotsky, V.K.; Keller, D.L.

    1982-10-01

    The tensile strength of beryllium to Monel vacuum furnace brazed joints was studied. The filler used was the 72% Ag-28%Cu(BAg-8) alloy. The strength of these joints, which require the use of a titanium hydride powder or physical vapor deposited titanium wetting agent on the beryllium, was found to approach the yield strength of the base metals. Strength was found to be reduced by the interaction of increased titanium hydride quantity and brazing time. Metallographic and scanning electron microscope (SEM) studies correlated these effects with microstructure. The formation of the brittle copper-beryllium delta phase was found to require conditions of high brazing temperature and the presence of a reservoir of the copper-containing filler such as found in fillet areas. Two other filler metals: pure silver, and a 60% Ag-30% Cu-10%Sn (BAg-17) alloy were shown to be acceptable alternatives to the BAg-8 alloy in cases where the filler metal can be preplaced between the base metal surfaces.

  19. Vacuum coupling of rotating superconducting rotor

    DOEpatents

    Shoykhet, Boris A.; Zhang, Burt Xudong; Driscoll, David Infante

    2003-12-02

    A rotating coupling allows a vacuum chamber in the rotor of a superconducting electric motor to be continually pumped out. The coupling consists of at least two concentric portions, one of which is allowed to rotate and the other of which is stationary. The coupling is located on the non-drive end of the rotor and is connected to a coolant supply and a vacuum pump. The coupling is smaller in diameter than the shaft of the rotor so that the shaft can be increased in diameter without having to increase the size of the vacuum seal.

  20. Vacuum system for the SAMURAI spectrometer

    NASA Astrophysics Data System (ADS)

    Shimizu, Y.; Otsu, H.; Kobayashi, T.; Kubo, T.; Motobayashi, T.; Sato, H.; Yoneda, K.

    2013-12-01

    The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.

  1. Vacuum control subsystem for the Fermilab Tevatron

    SciTech Connect

    Zagel, J.R.; Chapman, L.J.

    1981-06-01

    The CAMAC 170 module and CIA crate provide a convenient, cost effective method of interfacing any system requiring a large number of simple devices to be multiplexed into the Accelerator Control System. The system is ideal for relatively slowly changing systems where ten bit analog to digital conversions are sufficiently accurate. Together with vacuum interface CIA cards and prom-based software resident in the 170, this system is used to provide intelligent local monitoring and control for the Tevatron vacuum subsystems. Although not implemented in the vacuum interface, digital to analog converters could be included on the plug in modules as well, providing a total digital and analog multiplexing scheme. 2 refs.

  2. Vacuum resource provision for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Laskey, Kenneth J.; Mordfin, Theodore G.; Russ, Thomas W.

    1989-01-01

    The use of vacuum resources is integral to a number of proposed concepts for gas disposal from Space Staton Freedom. These include both direct overboard venting and onboard collection and storage of waste gases. A methodology is presented for determining flowrates through proposed vacuum lines. The flowrates through overboard vents are used to calculate number column densities, which are compared with current Freedom program requirements. The results are combined with discussions about the relative merits of some proposed and alternate concepts for providing vacuum resources.

  3. Cold vacuum drying facility site evaluation report

    SciTech Connect

    Diebel, J.A.

    1996-03-11

    In order to transport Multi-Canister Overpacks to the Canister Storage Building they must first undergo the Cold Vacuum Drying process. This puts the design, construction and start-up of the Cold Vacuum Drying facility on the critical path of the K Basin fuel removal schedule. This schedule is driven by a Tri-Party Agreement (TPA) milestone requiring all of the spent nuclear fuel to be removed from the K Basins by December, 1999. This site evaluation is an integral part of the Cold Vacuum Drying design process and must be completed expeditiously in order to stay on track for meeting the milestone.

  4. Local quasiequivalence and adiabatic vacuum states

    NASA Astrophysics Data System (ADS)

    Lüders, Christian; Roberts, John E.

    1990-11-01

    The problem of determining the physically relevant states acquires a new dimension in curved spacetime where there is, in general, no natural definition of a vacuum state. It is argued that there is a unique local quasiequivalence class of physically relevant states and it is shown how this class can be specified for the free Klein-Gordon field on a Robertson-Walker spacetime by using the concept of an adiabatic vacuum state. Any two adiabatic vacuum states of order two are locally quasiequivalent.

  5. Report of the Synchrotron Radiation Vacuum Workshop

    SciTech Connect

    Avery, R.T.

    1984-06-01

    The Synchrotron Radiation Vacuum Workshop was held to consider two vacuum-related problems that bear on the design of storage rings and beam lines for synchrotron radiation facilities. These problems are gas desorption from the vacuum chamber walls and carbon deposition on optical components. Participants surveyed existing knowledge on these topics and recommended studies that should be performed as soon as possible to provide more definitive experimental data on these topics. This data will permit optimization of the final design of the Advanced Light Source (ALS) and its associated beam lines. It also should prove useful for other synchrotron radiation facilities as well.

  6. Two-color bright squeezed vacuum

    SciTech Connect

    Agafonov, Ivan N.; Chekhova, Maria V.

    2010-07-15

    In a strongly pumped nondegenerate traveling-wave optical parametric amplifier, we produce a two-color squeezed vacuum with up to millions of photons per pulse. Our approach to registering this macroscopic quantum state is direct detection of a large number of transverse and longitudinal modes, which is achieved by making the detection time and area much larger than the coherence time and area, respectively. Using this approach, we obtain a record value of twin-beam squeezing for direct detection of bright squeezed vacuum. This makes direct detection of macroscopic squeezed vacuum a practical tool for quantum information applications.

  7. Improved Bakeout Chambers Within Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R.; Taylor, Daniel M.; Lane, Robert W.; Cortez, Maximo G.; Anderson, Mark R.

    1995-01-01

    Improved bakeout chamber incorporates hardware features that, in conjunction with improved bakeout procedure, reduce spurious contamination and increase accuracy of contamination measurements. When operated according to revised bakeout procedure, they yield measurements of contamination on vacuum-bake test articles more accurate than available previously, and potential for post-bake recontamination of vacuum-baked articles reduced. These chambers improved versions of one described in "Bakeout Chamber Within Vacuum Chamber" (NPO-18959). By enclosing test article in enclave and keeping walls of enclave hotter than test article during bakeout, one prevents condensation of contaminants on inner walls of enclave.

  8. Transient Molecular Transfer During Vacuum Testing

    NASA Technical Reports Server (NTRS)

    Perry, Radford L.

    2011-01-01

    A common question in contamination budgeting involves the loss of collected volatiles during ambient I&T activity under vacuum and the resultant cross-contamination from outgassing. (1) How much of the material collected under ambient conditions evaporates under vacuum? (2) Why do pristine surfaces sometimes show increased molecular contamination after vacuum bakeout? (3) How much of the collected molecular contamination is transient (i.e. migratory) and how much is permanent? Measuring the transient deposition may be accomplished using a thermally passive QCM

  9. Vacuum orientations in strong CP violation

    SciTech Connect

    Huang, Zheng; Viswanathan, K.S.; Wu, Dan-di

    1991-12-01

    We study the QCD vacuum orientation angles in correlation with the strong CP phases. A vacuum alignment equation of the dynamical chiral symmetry breaking is derived based on the anomalous Ward identity. It is emphasized that a chiral rotation of the quark field causes a change of the vacuum orientation and a change in the definition of the light pseudoscalar generators. As an illustration of the idea, {eta} {yields} 2{pi} decays are carefully studied in different chiral frames and shown to be independent of. chiral rotations.

  10. On Puthoff's Semiclassical Electron and Vacuum Energy

    NASA Astrophysics Data System (ADS)

    Pereira, N. R.

    2016-12-01

    A possible connection between a point electron and vacuum energy was recently claimed by Puthoff (Int. J. Theor. Phys. 46, 3005 (2007)). He envisions a point electron as an ideally conducting spherical shell with a distributed charge on the surface, in equilibrium with the radiation pressure from electromagnetic vacuum fluctuations on the outside, and claims that his analysis demonstrates the reality of high-energy-density vacuum fluctuation fields. The present paper finds, instead, that the analysis is meaningless without specific knowledge on the cutoff frequency that is a free parameter in the model.

  11. Performance tests of large thin vacuum windows

    SciTech Connect

    Hall Crannell

    2011-02-01

    Tests of thin composition vacuum windows of the type used for the Tagger in Hall B at the Thomas Jefferson National Accelerator Facility are described. Three different tests have been performed. These include: (1) measurement of the deformation and durability of a window under long term (>8 years) almost continuous vacuum load, (2) measurement of the deformation as a function of flexing of the window as it is cycled between vacuum and atmosphere, and (3) measurement of the relative diffusion rate of gas through a variety of thin window membranes.

  12. Co-sponsored second quarter progress review conference on district heating

    SciTech Connect

    1980-01-01

    A summary of the progress review conference on district heating and cooling systems is presented. The agenda and lists of speakers and attendees are presented. A history of district heating and some present needs and future policies are given and an excerpt from the National District Heating Program Strategy (DOE, March 1980) is included. Following the presentation, District Heating and Cooling Systems Program, by Alan M. Rubin, a fact sheet on DOE's Integrated Community Energy Systems Program and information from an oral presentation, District Heating and Cooling Systems for Communities Through Power Plant Retrofit Distribution Network, are given. The Second Quarterly Oral Report to the US DOE on the District Heating and Cooling Project in Detroit; the executive summary of the Piqua, Ohio District Heating and Cooling Demonstration Project; the Second Quarterly Report of the Moorehead, Minnesota District Heating Project; and the report from the Moorehead, Minnesota mayor on the Hot Water District Heating Project are presented.

  13. QAP co-sponsors global meeting on quality assurance in developing countries.

    PubMed

    1994-01-01

    A consultative meeting on quality health care in developing countries was held in the Netherlands immediately before the 1993 conference of the International Society of Quality Assurance in Health Care. Sponsored by the USAID-funded Quality Assurance Project in collaboration with the World Health Organization and the Danish foreign aid agency, DANIDA, the meeting brought together representatives from 17 developing countries. Participants enthusiastically exchanged experiences in adapting and applying quality assurance methods to resource-strained health care systems and valued the recommendations they received. Technical discussions focused on strategic planning, standard setting and monitoring, problem solving, and quality assurance capacity building. The meeting included background papers on each theme, synopses of the work of representatives of selected countries, and small group sessions. The participants recognized that certain structures, such as a data and health information monitoring system, must be in place to sustain a quality assurance program. There are also key environmental factors, including a commitment in the form of resource allocation from top leadership. The highlights of the meeting were presented at the general conference to great acclaim. Participants in the meeting benefitted from the information generated by the exchange of ideas and became unified in their understanding that quality assurance is a viable and necessary component of health care management. The success of the meeting led to the proposal which is under consideration that a permanent committee be established to ensure the participation of representatives of developing countries in international quality assurance activities.

  14. Is there vacuum when there is mass? Vacuum and non-vacuum solutions for massive gravity

    NASA Astrophysics Data System (ADS)

    Martín-Moruno, Prado; Visser, Matt

    2013-08-01

    Massive gravity is a theory which has a tremendous amount of freedom to describe different cosmologies, but at the same time, the various solutions one encounters must fulfil some rather nontrivial constraints. Most of the freedom comes not from the Lagrangian, which contains only a small number of free parameters (typically three depending on counting conventions), but from the fact that one is in principle free to choose the reference metric almost arbitrarily—which effectively introduces a non-denumerable infinity of free parameters. In the current paper, we stress that although changing the reference metric would lead to a different cosmological model, this does not mean that the dynamics of the universe can be entirely divorced from its matter content. That is, while the choice of reference metric certainly influences the evolution of the physically observable foreground metric, the effect of matter cannot be neglected. Indeed the interplay between matter and geometry can be significantly changed in some specific models; effectively since the graviton would be able to curve the spacetime by itself, without the need of matter. Thus, even the set of vacuum solutions for massive gravity can have significant structure. In some cases, the effect of the reference metric could be so strong that no conceivable material content would be able to drastically affect the cosmological evolution. Dedicated to the memory of Professor Pedro F González-Díaz

  15. SHINE Vacuum Pump Test Verification

    SciTech Connect

    Morgan, Gregg A; Peters, Brent

    2013-09-30

    Normetex pumps used world-wide for tritium service are no longer available. DOE and other researchers worldwide have spent significant funds characterizing this pump. Identification of alternate pumps is required for performance and compatibility with tritium gas. Many of the pumps that could be used to meet the functional performance requirements (e.g. pressure and flow conditions) of the Normetex pump have features that include the use of polymers or oils and greases that are not directly compatible with tritium service. This study assembles a test system to determine the flow characteristics for candidate alternate pumps. These tests are critical to the movement of tritium through the SHINE Tritium Purification System (TPS). The purpose of the pump testing is two-fold: (1) obtain baseline vacuum pump characteristics for an alternate (i.e. ''Normetex replacement'') pump intended for use in tritium service; and (2) verify that low pressure hydrogen gas can be transported over distances up to 300 feet by the candidate pumps. Flow rates and nominal system pressures have been identified for the SHINE Mo-99 production process Tritium Purification System (TPS). To minimize the line sizes for the transfer of low pressure tritium from the Neutron Driver Accelerator System (NDAS) to the primary processing systems in the TPS, a ''booster'' pump has been located near the accelerator in the design. A series of pump tests were performed at various configurations using hydrogen gas (no tritium) to ensure that this concept is practical and maintains adequate flow rates and required pressures. This report summarizes the results of the tests that have been performed using various pump configurations. The current design of the Tritium Purification System requires the ''booster'' pump to discharge to or to be backed by another vacuum pump. Since Normetex pumps are no longer manufactured, a commercially available Edwards scroll pump will be used to back the booster pump. In this

  16. SLAC All Access: Vacuum Microwave Device Department

    SciTech Connect

    Haase, Andy

    2012-10-09

    The Vacuum Microwave Device Department (VMDD) builds the devices that make SLAC's particle accelerators go. These devices, called klystrons, generate intense waves of microwave energy that rocket subatomic particles up to nearly the speed of light.

  17. SLAC All Access: Vacuum Microwave Device Department

    ScienceCinema

    Haase, Andy

    2016-07-12

    The Vacuum Microwave Device Department (VMDD) builds the devices that make SLAC's particle accelerators go. These devices, called klystrons, generate intense waves of microwave energy that rocket subatomic particles up to nearly the speed of light.

  18. Fate of electroweak vacuum during preheating

    SciTech Connect

    Ema, Yohei; Mukaida, Kyohei; Nakayama, Kazunori

    2016-10-28

    Our electroweak vacuum may be metastable in light of the current experimental data of the Higgs/top quark mass. If this is really the case, high-scale inflation models require a stabilization mechanism of our vacuum during inflation. A possible candidate is the Higgs-inflaton/-curvature coupling because it induces an additional mass term to the Higgs during the slow roll regime. However, after inflation, the additional mass term oscillates, and it can destabilize our electroweak vacuum via production of large Higgs fluctuations during the inflaton oscillation era. In this paper, we study whether or not the Higgs-inflaton/-curvature coupling can save our vacuum by properly taking account of Higgs production during the preheating stage. We put upper bounds on the Higgs-inflaton and -curvature couplings, and discuss possible dynamics that might relax them.

  19. Cold vacuum drying facility design requirements

    SciTech Connect

    Irwin, J.J.

    1997-09-24

    This release of the Design Requirements Document is a complete restructuring and rewrite to the document previously prepared and released for project W-441 to record the design basis for the design of the Cold Vacuum Drying Facility.

  20. Gravitational baryogenesis in running vacuum models

    NASA Astrophysics Data System (ADS)

    Oikonomou, V. K.; Pan, Supriya; Nunes, Rafael C.

    2017-08-01

    We study the gravitational baryogenesis mechanism for generating baryon asymmetry in the context of running vacuum models. Regardless of whether these models can produce a viable cosmological evolution, we demonstrate that they produce a nonzero baryon-to-entropy ratio even if the universe is filled with conformal matter. This is a sound difference between the running vacuum gravitational baryogenesis and the Einstein-Hilbert one, since in the latter case, the predicted baryon-to-entropy ratio is zero. We consider two well known and most used running vacuum models and show that the resulting baryon-to-entropy ratio is compatible with the observational data. Moreover, we also show that the mechanism of gravitational baryogenesis may constrain the running vacuum models.

  1. REVIEWS OF TOPICAL PROBLEMS: Cosmic vacuum

    NASA Astrophysics Data System (ADS)

    Chernin, Artur D.

    2001-11-01

    Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered.

  2. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, R.A.

    1986-05-15

    A material source replenishment device for use with a vacuum deposition apparatus is described. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  3. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, Ronald A.

    1988-01-01

    A material source replenishment device for use with a vacuum deposition apparatus. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  4. A Vacuum-Aspirator for Counting Termites

    Treesearch

    Susan C. Jones; Joe K. Mauldin

    1983-01-01

    An aspirator-system powered by a vacuum cleaner is described for manually counting termites. It is significantly faster and termite survival is at least as high as when using a mouth-aspirator for counting large numbers of termites.

  5. Recovery properties of vacuum spark gaps

    SciTech Connect

    Sampayan, S.E. ); Gurbaxani, S.H. . Dept. of Electrical Engineering); Buttram, M.T. . Pulsed Power Systems Dept.)

    1989-12-01

    Multi-kilohertz vacuum spark gap switching utilizing diffuse discharge and counter-pulse techniques has recently been demonstrated. In addition, commercial, high coulomb vacuum interrupter switches have shown free recovery rates greater than 10 kV / {mu}s. Thus, vacuum spark gap switches may provide an alternative method of high average power switching. The authors have investigated the recovery properties of a 90 kV, 15 kA multiple site, triggered vacuum spark gap. Triggering was accomplished with a multisite surface flashover plasma source with approximately 60 sites distributed over a 10 cm/sup 2/ area. Gap dimensions were 1-cm spacing by 7.5-cm diam. Recovery measurements are presented and discussed.

  6. Impact of gravity on vacuum stability

    NASA Astrophysics Data System (ADS)

    Branchina, Vincenzo; Messina, Emanuele; Zappalà, Dario

    2016-10-01

    In a pioneering paper on the role of gravity on false vacuum decay, Coleman and De Luccia showed that a strong gravitational field can stabilize the false vacuum, suppressing the formation of true vacuum bubbles. This result is obtained for the case in which the energy density difference between the two vacua is small, the so-called thin-wall regime, but is considered of more general validity. Here we show that when this condition does not hold, however, the effect of gravity on the bubble nucleation rate amounts to a small correction to the flat space-time result even in a strong gravity regime. This result suggests that the impact of gravity on the stability analysis of the electroweak vacuum could be essentially negligible.

  7. Mass spectrometer vacuum housing and pumping system

    DOEpatents

    Coutts, Gerald W.; Bushman, John F.; Alger, Terry W.

    1996-01-01

    A vacuum housing and pumping system for a portable gas chromatograph/mass spectrometer (GC/MS). The vacuum housing section of the system has minimum weight for portability while designed and constructed to utilize metal gasket sealed stainless steel to be compatible with high vacuum operation. The vacuum pumping section of the system consists of a sorption (getter) pump to remove atmospheric leakage and outgassing contaminants as well as the gas chromatograph carrier gas (hydrogen) and an ion pump to remove the argon from atmospheric leaks. The overall GC/MS system has broad application to contaminants, hazardous materials, illegal drugs, pollution monitoring, etc., as well as for use by chemical weapon treaty verification teams, due to the light weight and portability thereof.

  8. Mass spectrometer vacuum housing and pumping system

    DOEpatents

    Coutts, G.W.; Bushman, J.F.; Alger, T.W.

    1996-07-23

    A vacuum housing and pumping system is described for a portable gas chromatograph/mass spectrometer (GC/MS). The vacuum housing section of the system has minimum weight for portability while designed and constructed to utilize metal gasket sealed stainless steel to be compatible with high vacuum operation. The vacuum pumping section of the system consists of a sorption (getter) pump to remove atmospheric leakage and outgassing contaminants as well as the gas chromatograph carrier gas (hydrogen) and an ion pump to remove the argon from atmospheric leaks. The overall GC/MS system has broad application to contaminants, hazardous materials, illegal drugs, pollution monitoring, etc., as well as for use by chemical weapon treaty verification teams, due to the light weight and portability thereof. 7 figs.

  9. Vapor-barrier Vacuum Isolation System

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  10. Electrostatic particle collection in vacuum

    NASA Astrophysics Data System (ADS)

    Afshar-Mohajer, Nima; Damit, Brian; Wu, Chang-Yu; Sorloaica-Hickman, Nicoleta

    2011-09-01

    Lunar grains accumulate charges due to solar-based ionizing radiations, and the repelling action of like-charged particles causes the levitation of lunar dust. The lunar dust deposit on sensitive and costly surfaces of investigative equipment is a serious concern in lunar explorations. Inspired by electrostatic precipitators (ESPs), the Electrostatic Lunar Dust Collector (ELDC) was proposed for collecting already charged lunar dust particles to prevent the lunar dust threat. As the conditions for terrestrial counterparts are not valid in the lunar environment, equations developed for terrestrial devices yield incorrect predictions in lunar application. Hence, a mathematical model was developed for the ELDC operating in vacuum to determine its collection efficiency. The ratios of electrical energy over potential energy, kinetic energy over potential energy and the ratio of ELDC dimensions were identified to be the key dimensionless parameters. Sensitivity analyses of the relevant parameters showed that depending on ELDC orientation, smaller particles would be collected more easily at vertical orientation, whereas larger particles were easier to collect in a horizontal ELDC configuration. In the worst case scenario, the electrostatic field needed to be 10 times stronger in the vertical mode in order to adequately collect larger particles. The collection efficiency was very sensitive to surface potential of lunar dust and it reached the maximum when surface potential was between 30 and 120 V. Except for regions of the lunar day side with surface potential close to zero, providing 1 kV ( E = 20 kV m -1) with the ELDC was more than enough for collecting all the particles in the most critical orientation. The needed field strength was about 4000 times less than that for repelling 1-μm size particles already settled on the surfaces. The analysis shows that the ELDC offers a viable solution for lunar dust control due to its effectiveness, ease of cleaning and low voltage

  11. Vacuum level effects on gait characteristics for unilateral transtibial amputees with elevated vacuum suspension.

    PubMed

    Xu, Hang; Greenland, Kasey; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew

    2017-03-01

    The elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees. Three-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20inHg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups. The effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables. There was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20inHg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15inHg is suggested for unilateral transtibial amputees with elevated vacuum suspension. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Vacuum Ultraviolet Studies of Molecular Dynamics

    DTIC Science & Technology

    1992-01-15

    the Journal of Chemical Physics . Vacuum Ultraviolet Studies of Molecular Dynamics Page 4 B. Quenching of S(’D) by N2...An article on this work has been published in the Journal of Chemical Physics . E. The 157 am Photodissoclation of OCS The photodissociation of OCS...angular momentum vectors are perpendicular to one another. A report of this work has been published in the Journal of Chemical Physics . Vacuum

  13. Constrained potential method for false vacuum decays

    SciTech Connect

    Park, Jae-hyeon

    2011-02-01

    A procedure is reported for numerical analysis of false vacuum transition in a model with multiple scalar fields. It is a refined version of the approach by Konstandin and Huber. The alteration makes it possible to tackle a class of problems that was difficult or unsolvable with the original method, i.e. those with a distant or nonexistent true vacuum. An example with an unbounded-from-below direction is presented.

  14. Vacuum decay in an interacting multiverse

    NASA Astrophysics Data System (ADS)

    Robles-Pérez, S.; Alonso-Serrano, A.; Bastos, C.; Bertolami, O.

    2016-08-01

    We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  15. Vacuum spacetimes that admit no maximal slice

    NASA Astrophysics Data System (ADS)

    Witt, Donald M.

    1986-09-01

    Every closed three-manifold occurs as a spacelike hypersurface of a vacuum spacetime. For most of these three-manifolds, however, the vacuum spacetimes that contain them have no maximal slice. For asymptotically flat manifolds there are no restrictions on which three-manifolds can occur obeying the local energy conditions ρ>=(JaJa)1/2, and the spacetimes that contain them in most cases have no maximal slice.

  16. Reliable vacuum system cuts steam requirements 50%

    SciTech Connect

    Not Available

    1985-12-01

    In choosing a new high-vacuum system for fractional distillation, Polarome Manufacturing Company, New York, NY and Newark, NJ, a producer of high-quality flavor and fragrance chemicals, considered reliability and performance and steam consumption to be the most important factors. Distillation is carried out under vacuum to minimize thermal degradation. For stable operation, the vacuum system for the distillation column has to be ultra-reliable, and has to be able to go on-line quickly. Fluctuations in vacuum affect operating temperature and fractionation and cause deterioration of the product quality. Polarome's process requires a gas removal rate from the distillation column of 7.5 lg/hr of air plus 7.5 lb/hr of condensible vapors at 0.5 mm Hg absolute pressure at 105/sup 0/F. Polarome chose a combination ejector/liquid ring pump system that combines the two distinctly different types of equipment to improve high-vacuum efficiency. The unit requires only 400 lb/hr of motive steam at 125 psig, and the liquid ring pump only draws 5.7 brake hp. Polarome purchased two virtually identical four-stage systems, each composed of two ejector stages, a shell-and-tube condenser, and a two-stage liquid ring vacuum pump. The fully packaged systems were delivered skid-mounted, ready to pipe and operate. Polarome found a number of advantages with their combined system. Steam savings are considerable - up to 50% over a conventional ejector system - because the liquid-ring pump is substituted for the less efficient final two ejector stages. In Polarome's vacuum range of 0.5 mm Hg, this was considered the most efficient way of drawing vacuum, with lowest investment and operating costs for the greatest capacity.

  17. Three-neutrino mixing and combined vacuum oscillations and MSW transitions of solar neutrinos

    SciTech Connect

    Liu, Q.Y.; Petcov, S.T. |

    1997-12-01

    Assuming three-flavor neutrino mixing takes place in vacuum, we investigate the possibility that the solar {nu}{sub e} take part in MSW transitions in the Sun due to {Delta}m{sub 31}{sup 2}{approximately}(10{sup {minus}7}{minus}10{sup {minus}4}) eV{sup 2}, followed by long wavelength vacuum oscillations on the way to the Earth, triggered by {Delta}m{sub 21}{sup 2} (or {Delta}m{sub 32}{sup 2}) {approximately}(10{sup {minus}12}{minus}10{sup {minus}10}) eV{sup 2}, {Delta}m{sub 31}{sup 2} and {Delta}m{sub 21}{sup 2} ({Delta}m{sub 32}{sup 2}) being the corresponding neutrino mass squared differences. The solar {nu}{sub e} survival probability is shown to be described in this case by a simple analytic expression. Depending on whether the vacuum oscillations are due to {Delta}m{sub 21}{sup 2} or {Delta}m{sub 32}{sup 2} there are two very different types of interplay between the MSW transitions and the vacuum oscillations of the solar {nu}{sub e}. Performing an analysis of the most recently published solar neutrino data we have found several qualitatively new solutions of the solar neutrino problem of the hybrid MSW transitions + vacuum oscillations type. The solutions differ in the way the pp, {sup 7}Be and {sup 8}B neutrino fluxes are affected by the transitions in the Sun and the oscillations in vacuum. The specific features of the new solutions are discussed. One of the distinctive predictions of the hybrid MSW + vacuum oscillation solutions found is the existence of strong and very characteristic distortions of the spectrum of {sup 8}B neutrinos. {copyright} {ital 1997} {ital The American Physical Society}

  18. Cryogenic Insulation System for Soft Vacuum

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, J. E.

    1999-01-01

    The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

  19. 7 CFR 58.230 - Heavy duty vacuum cleaners.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy duty industrial vacuum cleaner. The vacuum cleaner shall be of a type that has a collector...

  20. 7 CFR 58.230 - Heavy duty vacuum cleaners.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy duty industrial vacuum cleaner. The vacuum cleaner shall be of a type that has a collector...

  1. 21 CFR 884.4340 - Fetal vacuum extractor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fetal vacuum extractor. 884.4340 Section 884.4340....4340 Fetal vacuum extractor. (a) Identification. A fetal vacuum extractor is a device used to... means of a suction cup attached to the scalp and is powered by an external vacuum source. This...

  2. 46 CFR 105.10-20 - Pressure vacuum relief valve.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in...

  3. 7 CFR 58.230 - Heavy duty vacuum cleaners.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy duty industrial vacuum cleaner. The vacuum cleaner shall be of a type that has a collector...

  4. 21 CFR 884.4340 - Fetal vacuum extractor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fetal vacuum extractor. 884.4340 Section 884.4340....4340 Fetal vacuum extractor. (a) Identification. A fetal vacuum extractor is a device used to... means of a suction cup attached to the scalp and is powered by an external vacuum source. This...

  5. 7 CFR 58.230 - Heavy duty vacuum cleaners.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy duty industrial vacuum cleaner. The vacuum cleaner shall be of a type that has a collector...

  6. 21 CFR 884.4340 - Fetal vacuum extractor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fetal vacuum extractor. 884.4340 Section 884.4340....4340 Fetal vacuum extractor. (a) Identification. A fetal vacuum extractor is a device used to... means of a suction cup attached to the scalp and is powered by an external vacuum source. This...

  7. 7 CFR 58.230 - Heavy duty vacuum cleaners.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Heavy duty vacuum cleaners. 58.230 Section 58.230....230 Heavy duty vacuum cleaners. Each plant handling dry milk products shall be equipped with a heavy duty industrial vacuum cleaner. The vacuum cleaner shall be of a type that has a collector...

  8. Vacuum Energy and Inflation: 4. An Inflationary Universe

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2013-01-01

    This is the fourth paper in a series of four. The first paper in the series, "Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy" [EJ1024183] discusses an example of vacuum energy. Vacuum energy is explained as an energy with a negative pressure whose energy density remains constant in an expanding space. Paper 2, "Vacuum…

  9. 46 CFR 105.10-20 - Pressure vacuum relief valve.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in...

  10. 46 CFR 105.10-20 - Pressure vacuum relief valve.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in...

  11. 46 CFR 105.10-20 - Pressure vacuum relief valve.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in...

  12. 46 CFR 105.10-20 - Pressure vacuum relief valve.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in...

  13. 40 CFR 1065.345 - Vacuum-side leak verification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... a leak. (e) Vacuum-decay leak test. To perform this test you must apply a vacuum to the vacuum-side volume of your sampling system and then observe the leak rate of your system as a decay in the applied... specifications of subpart C of this part and of this subpart D. Perform a vacuum-decay leak test as follows: (1...

  14. Vacuum Energy and Inflation: 4. An Inflationary Universe

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2013-01-01

    This is the fourth paper in a series of four. The first paper in the series, "Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy" [EJ1024183] discusses an example of vacuum energy. Vacuum energy is explained as an energy with a negative pressure whose energy density remains constant in an expanding space. Paper 2, "Vacuum…

  15. Mentoring in Native American Communities using STEM Concepts

    NASA Astrophysics Data System (ADS)

    Angrum, A.; Alexander, C. J.; Martin, M.

    2011-12-01

    In this paper we will present a concept for mentoring built on STEM principles, and applied to the Native American community in Chinle, AZ. Effective mentoring includes being sensitive, listening to, and advising mentees based upon a 'correct' appreciation not only of their needs but also of the desires of the community they come from. Our project is an outreach effort on the part of NASA's contribution to the International Rosetta mission. Our initial program design incorporated ambitious STEM materials developed by NASA/JPL for other communities that excite and engage future generations in geoscience careers, to be re-packaged and brought to the Navajo community in Chinle. We were cognizant of the communities' emphasis on the need to know themselves and their own culture when teaching their students. Recognizing that one of the most important near-term problems in Native American communities across the country is preservation of aboriginal language, a first step in our program involved defining STEM vocabulary. Community participation was required to identify existing words, write a STEM thesaurus, and also define contemporary words (what we called 'NASA words') that have no equivalent in the native tongue. This step critically involved obtaining approval of new words from tribal Elders. Finally, our objective was to put this newly defined STEM vocabulary to work, helping the kids to learn STEM curriculum in their own language. The communities' response to our approach was guarded interest, an invitation to return for further work, and finally a request that we co-sponsor a Summer Science Academy that was not focused on the subjects of space exploration originally envisioned by the project. Thus a first lesson learned was that ambitious material might not be the first step to a sustained educational program on the reservation. Understanding the end-users' environment, requirements and constraints is a major component to sustainability. After several months of

  16. Cold Vacuum Drying (CVD) Set Point Determination

    SciTech Connect

    PHILIPP, B.L.

    2000-09-04

    The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO annulus on high Tempered Water (TW) inlet temperature. For the MCO isolation and purge, the SCIC receives MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switch status, seismic trip status, and time-under-vacuum trips signals. The SCIC system will isolate the MCO and start an SCHe system purge if any of the following occur. (1) Isolation and purge from one of the SCHe ''isolation'' and ''purge'' buttons is manually initiated (administratively controlled). (2) The first vacuum cycle exceeds 8 hours at vacuum, or any subsequent vacuum cycle exceeds 4 hours at vacuum without re-pressurizing the MCO for a minimum of 4 hours. (This is referred to as the 8/4/4 requirement and provides thermal equilibrium within the MCO.) (3) MCO is below atmospheric pressure and the helium flow is below the minimum required to keep hydrogen less than 4% by volume. (When MCO pressure is below 12 torr there is insufficient hydrogen to exceed the 4% level and therefore no purge is required. A five minute time delay on low flow allows flow to be stopped in order to reach < 12 torr.) (4) The duration for the transition from above atmospheric pressure to vacuum (time to reach pressure below -11.7 psig [{approx}155 torr]) exceeds 5 minutes. (5) The duration for the transition from vacuum (below -11.1 psig [{approx}185 torr]) back to pressure [greater than 0.5 psig] exceeds 5 minutes. (6) MCO reaches a vacuum state (<0.5 psig) without an adequate, verified purge volume. (The MCO must be maintained above atmospheric pressure (approximately 0.5 psig) to prevent

  17. Vacuum Bellows, Vacuum Piping, Cryogenic Break, and Copper Joint Failure Rate Estimates for ITER Design Use

    SciTech Connect

    L. C. Cadwallader

    2010-06-01

    The ITER international project design teams are working to produce an engineering design in preparation for construction of the International Thermonuclear Experimental Reactor (ITER) tokamak. During the course of this work, questions have arisen in regard to safety barriers and equipment reliability as important facets of system design. The vacuum system designers have asked several questions about the reliability of vacuum bellows and vacuum piping. The vessel design team has asked about the reliability of electrical breaks and copper-copper joints used in cryogenic piping. Research into operating experiences of similar equipment has been performed to determine representative failure rates for these components. The following chapters give the research results and the findings for vacuum system bellows, power plant stainless steel piping (amended to represent vacuum system piping), cryogenic system electrical insulating breaks, and copper joints.

  18. Vacuum-packaging of bovine edible offal.

    PubMed

    Patterson, J T; Gibbs, P A

    1979-07-01

    Edible offals are relatively perishable and may be frozen before leaving the abattoir, commanding a lower price on the wholesale market than fresh offals. Investigations are described in which a range of offals was vacuum-packaged in an effort to extend the shelf-life of the fresh material. Several visits to two abattoirs revealed that their offals after chilling were generally of rather poor microbiological quality, partly due to handling practices and, in one abattoir, to inadequate chilling. Reductions in the initial microbial load on hearts and tongues were achieved by immersion in water at 90°C, or with 100 ppm free chlorine or 1 % (v/v) lactic acid. However, these treatments offered no advantage over good production methods in extending the safe storage period in the vacuum-package. When offals produced under normal conditions were vacuum-packaged a storage period of 2-3 weeks at 1°C ± 1° was achieved which allowed a subsequent shelf-life of 3-4 days in air at 4°C. Offals produced with low initial numbers of contaminants gave the possibility of 1-2 weeks longer in the vacuum-package. A detailed investigation of the organisms growing on vacuum-packaged liver showed that a lactic flora developed during storage, but this did not inhibit potential spoilage organisms such as Pseudomonas or Alteromonas.

  19. Recent advances in vacuum sciences and applications

    NASA Astrophysics Data System (ADS)

    Mozetič, M.; Ostrikov, K.; Ruzic, D. N.; Curreli, D.; Cvelbar, U.; Vesel, A.; Primc, G.; Leisch, M.; Jousten, K.; Malyshev, O. B.; Hendricks, J. H.; Kövér, L.; Tagliaferro, A.; Conde, O.; Silvestre, A. J.; Giapintzakis, J.; Buljan, M.; Radić, N.; Dražić, G.; Bernstorff, S.; Biederman, H.; Kylián, O.; Hanuš, J.; Miloševič, S.; Galtayries, A.; Dietrich, P.; Unger, W.; Lehocky, M.; Sedlarik, V.; Stana-Kleinschek, K.; Drmota-Petrič, A.; Pireaux, J. J.; Rogers, J. W.; Anderle, M.

    2014-04-01

    Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure measurements with temporal resolution of 2 ms. Vacuum issues in the construction of huge ultra-high vacuum devices worldwide are reviewed. Recent advances in surface science and thin films include new phenomena observed in electron transport near solid surfaces as well as novel results on the properties of carbon nanomaterials. Precise techniques for surface and thin-film characterization have been applied in the conservation technology of cultural heritage objects and recent advances in the characterization of biointerfaces are presented. The combination of various vacuum and atmospheric-pressure techniques enables an insight into the complex phenomena of protein and other biomolecule conformations on solid surfaces. Studying these phenomena at solid-liquid interfaces is regarded as the main issue in the development of alternative techniques for drug delivery, tissue engineering and thus the development of innovative techniques for curing cancer and cardiovascular diseases. A review on recent advances in plasma medicine is presented as well as novel hypotheses on cell apoptosis upon treatment with gaseous plasma. Finally, recent advances in plasma nanoscience are illustrated with several examples and a roadmap for future activities is presented.

  20. Compressed Air/Vacuum Transportation Techniques

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  1. Engineering Matter Interactions Using Squeezed Vacuum

    NASA Astrophysics Data System (ADS)

    Zeytinoǧlu, Sina; Imamoǧlu, Ataç; Huber, Sebastian

    2017-04-01

    Virtually all interactions that are relevant for atomic and condensed matter physics are mediated by quantum fluctuations of the electromagnetic field vacuum. Consequently, controlling the vacuum fluctuations can be used to engineer the strength and the range of interactions. Recent experiments have used this premise to demonstrate novel quantum phases or entangling gates by embedding electric dipoles in photonic cavities or wave guides, which modify the electromagnetic fluctuations. Here, we show theoretically that the enhanced fluctuations in the antisqueezed quadrature of a squeezed vacuum state allow for engineering interactions between electric dipoles without the need for a photonic structure. Thus, the strength and range of the interactions can be engineered in a time-dependent way by changing the spatial profile of the squeezed vacuum in a traveling-wave geometry, which also allows the implementation of chiral dissipative interactions. Using experimentally realized squeezing parameters and including realistic losses, we predict single-atom cooperativities C of up to 10 for the squeezed-vacuum-enhanced interactions.

  2. Treatment of vacuum residues in hydroconversion conditions

    NASA Astrophysics Data System (ADS)

    León, A. Y.; Mendoza, D. L.; Espinosa, J. O.; Laverde, D.

    2016-02-01

    In this paper the use of a liquid homogeneous catalyst has been studied in reactivity vacuum residues by hydroconversion under different conditions. To cover a wide range of compositions, six (6) vacuum residues were selected from crude mixtures. Hydroconversion test were performed in batch reactor with hydrogen atmosphere at about 2000psi in a temperature range between 430 and 480°C. The results allowed to establish that the reactivity hydroconversion conditions about coke formation is higher in vacuum residues with higher content of resins and asphaltenes. The reaction conditions promote distillate formation, however, with increasing stringency conditions, the distillate yield decreases due to distillate transformation into temperature range 430 and 460°C compared to the tests performed without catalyst demonstrating that the use of homogeneous catalyst is an alternative to treating vacuum residues and results are satisfactory in the conversion processes. Finally, predictive expressions have been developed in the formation of products depending on the conditions of temperature and physicochemical properties of processed vacuum residue.

  3. Endoscopic vacuum sponge therapy for esophageal defects.

    PubMed

    Loske, Gunnar; Schorsch, Tobias; Müller, Christian

    2010-10-01

    Anastomotic insufficiency in esophageal anastomosis and esophageal defects of other etiology are very severe complications. For anastomotic insufficiency in the rectum, endoscopic vacuum therapy has already been used successfully. The authors used vacuum therapy for anastomotic defects and other lesions of the esophagus. Between November 2006 and September 2009, 10 patients (5 men and 5 women, ages 46-82 years) were treated with endoscopic vacuum sponge therapy for anastomotic insufficiency secondary to esophagectomy or gastrectomy (n = 5), iatrogenic esophageal perforation (n = 2), esophageal wall necrosis (n = 1), Boerhaave's syndrome (n = 1), and perforation of esophageal cancer (n = 1). After one to seven changes of the sponge at intervals of 2-7 days and a mean therapy duration of 12 days, the defects were healed in all the surviving patients. During treatment, the patients were fed via an intestinal tube or percutaneous endoscopic gastrostomy (PEG), or enterally past the sponge. One patient died of intercurrent severe colitis. In three cases, a revision laparotomy was necessary at the beginning of treatment. No postinterventional stricture or functional relevant scar formation was observed during a follow-up period of 10-380 days after termination of the vacuum therapy. Esophageal anastomotic insufficiency and esophageal wall defects of other causes can be treated successfully with endoscopic vacuum sponge therapy.

  4. Seismic analysis of a vacuum vessel

    SciTech Connect

    Chen, W.W.

    1993-01-01

    This paper presents the results of the seismic analysis for the preliminary design of a vacuum vessel for the ground engineering system (GES) of the SP-100 project. It describes the method of calculating the elevated seismic response spectra at various levels within the vacuum vessel using the simplified computer code developed by Weiner. A modal superposition analysis under design response spectra loading was performed for a three-dimensional finite-element model using the general-purpose finite-element computer code ANSYS. The in-vessel elevated seismic response spectra at various levels in the vacuum vessel, along with vessel mode shapes and frequencies are presented. Also included are descriptions of the results of the modal analyses for some significant preliminary design points at various elevations of the vessel.

  5. Vacuum packaging design and analysis for UFPA

    NASA Astrophysics Data System (ADS)

    Liu, Dafu; Xu, Qinfei

    2010-10-01

    Uncooled focal plane array (UFPA) has broad application prospects in civilian and space because it's cheaper, more compact and high reliability. Many research institutes and companies have carried out the research of uncooled focal plane array. This paper shows a vacuum package design of UFPA, and its architecture will be given. The assembly is an all-metal vacuum package, which has been proven rugged and reliable. Out-gassing, permeation, evaporator, and air leak are factors to reduce the component vacuum lifetime. Theoretical analysis shows that material out-gassing is the main factor of pressure rise inside package. Theoretical analysis and calculation show that designed metallic structure can meet the need of 10-years life.

  6. Vacuum interrupters and thyratrons as opening switches

    NASA Astrophysics Data System (ADS)

    Honig, E. M.

    High power opening switches for inductive storage for large scale energy storage applications are described. The triggered vacuum interrupter and the magnetically quenched thyratrons are discussed. By electrically retriggering the discharge in the vacuum interrupter between pulses, the dependence on mechanical motion is eliminated. This should enable repetition rate operation at 10 to 15 kHz while still maintaining the vacuum interrupter's proven interrupting performance of tens of kiloamps at tens of kilovolts. The magnetically quenched thyratron uses a cross magnetic field to raise the switch impedance by decreasing the electron mobility and driving the discharge into an arc chute wall where it is quenched. Attempts to understand the basic mechanisms involved and to increase the switch, ratings, and particularly the conduction time, are discussed.

  7. Holographic Ricci dark energy as running vacuum

    NASA Astrophysics Data System (ADS)

    George, Paxy; Mathew, Titus K.

    2016-04-01

    Holographic Ricci dark energy (DE) that has been proposed ago has faced problems of future singularity. In the present work, we consider the Ricci DE with an additive constant in its density as running vacuum energy. We have analytically solved the Friedmann equations and also the role played by the general conservation law followed by the cosmic components together. We have shown that the running vacuum energy status of the Ricci DE helps to remove the possible future singularity in the model. The additive constant in the density of the running vacuum played an important role, such that, without that, the model predicts either eternal deceleration or eternal acceleration. But along with the additive constant, equivalent to a cosmological constant, the model predicts a late time acceleration in the expansion of the universe, and in the far future of the evolution it tends to de Sitter universe.

  8. Plasma-cathode-initiated vacuum gap closure

    SciTech Connect

    Sampayan, S.E.; Gurbaxani, S.H. ); Buttram, M.T. )

    1990-09-01

    The properties of vacuum gap closure initiated by a plasma cathode are presented. The plasma cathode consisted of approximately 60 surface flashover sites distributed over a 10-cm{sup 2} area. Vacuum gap dimensions were 1{times}7.5 cm in diameter. Faraday cup measurements indicated an ion density greater than 10{sup 12} cm{sup {minus}3}, which was controllable by the amplitude of the initiating high-voltage pulse. Although the field-free expansion velocity of the plasma was measured to be 7 cm/{mu}s, plasma-cathode-initiated closure of the vacuum gap indicated closure speeds on the order of 0.5 cm/{mu}s. Also, increased injected ion density and increased anode-cathode potential resulted in increased closure velocity.

  9. In-vacuum Faraday isolation remote tuning.

    PubMed

    Accadia, T; Acernese, F; Antonucci, F; Aoudia, S; Arun, K G; Astone, P; Ballardin, G; Barone, F; Barsuglia, M; Bauer, Th S; Beker, M G; Bigotta, S; Birindelli, S; Bitossi, M; Bizouard, M A; Blom, M; Boccara, C; Bondu, F; Bonelli, L; Bosi, L; Braccini, S; Bradaschia, C; Brillet, A; Brisson; Budzynski, R; Bulik, T; Bulten, H J; Buskulic, D; Cagnoli, G; Calloni, E; Campagna, E; Canuel, B; Carbognani, F; Cavalier, F; Cavalieri, R; Cella, G; Cesarini, E; Chassande-Mottin, E; Chincarini, A; Cleva, F; Coccia, E; Colacino, C N; Colas, J; Colla, A; Colombini, M; Corda, C; Corsi, A; Coulon, J-P; Cuoco, E; D'Antonio, S; Dari, A; Dattilo, V; Davier, M; Day, R; De Rosa, R; del Prete, M; Di Fiore, L; Di Lieto, A; Emilio, M Di Paolo; Di Virgilio, A; Dietz, A; Drago, M; Fafone, V; Ferrante, I; Fidecaro, F; Fiori, I; Flaminio, R; Fournier, J-D; Franc, J; Frasca, S; Frasconi, F; Freise, A; Gammaitoni, L; Garufi, F; Gemme, G; Genin, E; Gennai, A; Giazotto, A; Gouaty, R; Granata, M; Greverie, C; Guidi, G M; Heitmann, H; Hello, P; Hild, S; Huet, D; Jaranowski, P; Kowalska, I; Królak, A; La Penna, P; Leroy, N; Letendre, N; Li, T G F; Lorenzini, M; Loriette, V; Losurdo, G; Mackowski, J M; Majorana, E; Man, N; Mantovani, M; Marchesoni, F; Marion, F; Marque, J; Martelli, F; Masserot, A; Michel, C; Milano, L; Minenkov, Y; Mohan, M; Moreau, J; Morgado, N; Morgia, A; Mosca, S; Moscatelli, V; Mours, B; Neri, I; Nocera, F; Pagliaroli, G; Palladino, L; Palomba, C; Paoletti, F; Pardi, S; Parisi, M; Pasqualetti, A; Passaquieti, R; Passuello, D; Persichetti, G; Pichot, M; Piergiovanni, F; Pietka, M; Pinard, L; Poggiani, R; Prato, M; Prodi, G A; Punturo, M; Puppo, P; Rabaste, O; Rabeling, D S; Rapagnani, P; Re, V; Regimbau, T; Ricci, F; Robinet, F; Rocchi, A; Rolland, L; Romano, R; Rosińska, D; Ruggi, P; Sassolas, B; Sentenac, D; Sturani, R; Swinkels, B; Toncelli, A; Tonelli, M; Tournefier, E; Travasso, F; Trummer, J; Vajentei, G; van den Brand, J F J; van der Putten, S; Vavoulidis, M; Vedovato, G; Verkindt, D; Vetrano, F; Viceré, A; Vinet, J-Y; Vocca, H; Was, M; Yvert, M

    2010-09-01

    In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.

  10. Extremal vacuum black holes in higher dimensions

    SciTech Connect

    Figueras, Pau; Lucietti, James; Rangamani, Mukund; Kunduri, Hari K.

    2008-08-15

    We consider extremal black hole solutions to the vacuum Einstein equations in dimensions greater than five. We prove that the near-horizon geometry of any such black hole must possess an SO(2,1) symmetry in a special case where one has an enhanced rotational symmetry group. We construct examples of vacuum near-horizon geometries using the extremal Myers-Perry black holes and boosted Myers-Perry strings. The latter lead to near-horizon geometries of black ring topology, which in odd spacetime dimensions have the correct number of rotational symmetries to describe an asymptotically flat black object. We argue that a subset of these correspond to the near-horizon limit of asymptotically flat extremal black rings. Using this identification we provide a conjecture for the exact 'phase diagram' of extremal vacuum black rings with a connected horizon in odd spacetime dimensions greater than five.

  11. Probing the quantum vacuum with petawatt lasers

    NASA Astrophysics Data System (ADS)

    Hill, W. T., III; Roso, L.

    2017-07-01

    Due to the bosonic nature of the photon, increasing the peak intensity through a combination of raising the pulse energy and decreasing the pulse duration will pile up more and more photons within the same finite region of space. In the absence of material, this continues until the vacuum is stressed to the point of breakdown and virtual particles become real. The critical intensity where this occurs for electrons and positrons - the so-called Schwinger limit - is predicted to be ˜ 1029 W/cm2. At substantially lower intensities, however, nonlinear aspects of the quantum vacuum associated with polarization of the vacuum can be explored. These studies become viable at the petawatt level where 1023 W/cm2 and above can be reached. This is an era into which we are just embarking that will provide critical tests of QED and theories beyond the Standard Model of particle physics.

  12. Vacuum Outgassing of High Density Polyethylene

    SciTech Connect

    Dinh, L N; Sze, J; Schildbach, M A; Chinn, S C; Maxwell, R S; Raboin, P; McLean II, W

    2008-08-11

    A combination of thermogravimetric analysis (TGA) and temperature programmed decomposition (TPD) was employed to identify the outgassing species, the total amount of outgassing, and the outgassing kinetics of high density polyethylene (HDPE) in a vacuum environment. The isoconversional kinetic analysis was then used to analyze the outgassing kinetics and to predict the long-term outgassing of HDPE in vacuum applications at ambient temperature. H{sub 2}O and C{sub n}H{sub x} with n as high as 9 and x centering around 2n are the major outgassing species from solid HDPE, but the quantities evolved can be significantly reduced by vacuum baking at 368 K for a few hours prior to device assembly.

  13. A Road Map to Extreme High Vacuum

    SciTech Connect

    Myneni, Ganapati Rao

    2007-06-20

    Ultimate pressure of a well-designed vacuum system very much depends on pretreatments, processing and the procedures [1,2]. Until now much attention has been paid in minimizing hydrogen outgassing from the chamber material. However, procedures and processing deserves further scrutiny than hitherto given so far. For reducing the gas load, high sensitivity helium leak detection techniques with sensitivities better than 1× 10-12 Torr l/sec need to be used. Effects that are induced by vacuum instrumentation need to be reduced in order to obtain accurate pressure measurements. This presentation will discuss: clean assembly procedures, metal sponges for cryosorption pumping of hydrogen to extreme high vacuum, low cost surface diffusion barriers for reducing the hydrogen gas load, cascade pumping, sensitive helium leak detection techniques and the use of modified extractor and residual gas analyzers. Further, alternative back up pumping systems based on active NEG’s [3] for turbo molecular pumps will be presented.

  14. Giant vacuum forces via transmission lines

    PubMed Central

    Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon

    2014-01-01

    Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line. PMID:25002503

  15. Topological vacuum bubbles by anyon braiding

    PubMed Central

    Han, Cheolhee; Park, Jinhong; Gefen, Yuval; Sim, H.-S.

    2016-01-01

    According to a basic rule of fermionic and bosonic many-body physics, known as the linked cluster theorem, physical observables are not affected by vacuum bubbles, which represent virtual particles created from vacuum and self-annihilating without interacting with real particles. Here we show that this conventional knowledge must be revised for anyons, quasiparticles that obey fractional exchange statistics intermediate between fermions and bosons. We find that a certain class of vacuum bubbles of Abelian anyons does affect physical observables. They represent virtually excited anyons that wind around real anyonic excitations. These topological bubbles result in a temperature-dependent phase shift of Fabry–Perot interference patterns in the fractional quantum Hall regime accessible in current experiments, thus providing a tool for direct and unambiguous observation of elusive fractional statistics. PMID:27030442

  16. Vacuum Spacetimes with Constant Weyl Eigenvalues

    NASA Astrophysics Data System (ADS)

    Barnes, A.

    2015-04-01

    Einstein spacetimes (that is vacuum spacetimes possibly with a non-zero cosmological constant Λ) with constant non-zero Weyl eigenvalues are considered. For type Petrov II & D this assumption allows one to prove that the non-repeated eigenvalue necessarily has the value 2Λ/3 and it turns out that the only possible spacetimes are some Kundt-waves considered by Lewandowski which are type II and a Robinson-Bertotti solution of type D. For Petrov type I the only solution turns out to be a homogeneous pure vacuum solution found long ago by Petrov using group theoretic methods. These results can be summarised by the statement that the only vacuum spacetimes with constant Weyl eigenvalues are either homogeneous or are Kundt spacetimes. This result is similar to that of Coley et al. who proved their result for general spacetimes under the assumption that all scalar invariants constructed from the curvature tensor and all its derivatives were constant.

  17. Sequestering the standard model vacuum energy.

    PubMed

    Kaloper, Nemanja; Padilla, Antonio

    2014-03-07

    We propose a very simple reformulation of general relativity, which completely sequesters from gravity all of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume element of the Universe. For them to be nonzero, the Universe should be finite in spacetime. If this matter is the standard model of particle physics, our mechanism prevents any of its vacuum energy, classical or quantum, from sourcing the curvature of the Universe. The mechanism is consistent with the large hierarchy between the Planck scale, electroweak scale, and curvature scale, and early Universe cosmology, including inflation. Consequences of our proposal are that the vacuum curvature of an old and large universe is not zero, but very small, that w(DE) ≃ -1 is a transient, and that the Universe will collapse in the future.

  18. Thermodynamical aspects of running vacuum models

    NASA Astrophysics Data System (ADS)

    Lima, J. A. S.; Basilakos, Spyros; Solà, Joan

    2016-04-01

    The thermal history of a large class of running vacuum models in which the effective cosmological term is described by a truncated power series of the Hubble rate, whose dominant term is Λ (H) ∝ H^{n+2}, is discussed in detail. Specifically, by assuming that the ultrarelativistic particles produced by the vacuum decay emerge into space-time in such a way that its energy density ρ _r ∝ T4, the temperature evolution law and the increasing entropy function are analytically calculated. For the whole class of vacuum models explored here we find that the primeval value of the comoving radiation entropy density (associated to effectively massless particles) starts from zero and evolves extremely fast until reaching a maximum near the end of the vacuum decay phase, where it saturates. The late-time conservation of the radiation entropy during the adiabatic FRW phase also guarantees that the whole class of running vacuum models predicts the same correct value of the present day entropy, S0 ˜ 10^{87}-10^{88} (in natural units), independently of the initial conditions. In addition, by assuming Gibbons-Hawking temperature as an initial condition, we find that the ratio between the late-time and primordial vacuum energy densities is in agreement with naive estimates from quantum field theory, namely, ρ _{Λ 0}/ρ _{Λ I} ˜ 10^{-123}. Such results are independent on the power n and suggests that the observed Universe may evolve smoothly between two extreme, unstable, non-singular de Sitter phases.

  19. Vacuum energy of a spherical plasma shell

    NASA Astrophysics Data System (ADS)

    Bordag, M.; Khusnutdinov, N.

    2008-04-01

    We consider the vacuum energy of the electromagnetic field interacting with a spherical plasma shell together with a model for the classical motion of the shell. We calculate the heat kernel coefficients, especially that for the TM mode, and carry out the renormalization by redefining the parameters of the classical model. It turns out that this is possible and results in a model which, in the limit of the plasma shell becoming an ideal conductor, reproduces the vacuum energy found by Boyer in 1968.

  20. Remote vacuum joint concept for fusion reactors

    SciTech Connect

    Doll, D.W.; Hager, E.R.

    1983-09-01

    A remotely operable vacuum duct joint has been designed by GA Technologies, Inc. The concept is applicable to large rectangular vacuum ducts, many of which are required on advanced fusion devices. The duct size chosen for this design is 1m X .4m although it may be scaled up or down for other applications. Shaft driven mechanical linkages provide a large axial force against one flange which is reacted by latch mechanisms that engage the mating flange. Drive shafts are actuated by an impact wrench handled by a remote manipulator. Remote disassembly time is about 3 hours.

  1. Remote vacuum compaction of compressible hazardous waste

    DOEpatents

    Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

    1998-10-06

    A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

  2. MEANS AND METHOD FOR PRODUCING A VACUUM

    DOEpatents

    Otavka, M.A.

    1960-08-01

    A new method is given for starting the operation of evapor-ion vacuum pumps. Ordinarily this type of pump is started by inducing an electric field with the vacuum chamber; however, by placing such an electric field in the chamber at the outset, a glow discharge may be initiated which is harmful to the pump. The procedure consists of using a negative electric field during which time only gettering action takes place; subsequently when the field reverses after a sufficient reduction of the number of gaseous particles in the chamber both gettering and ionizing takes place.

  3. Cold Vacuum Drying (CVD) Set Point Determination

    SciTech Connect

    PHILIPP, B.L.

    2000-03-21

    The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO on high tempered water MCO inlet temperature. For the MCO isolation and purge, the SCIC receives signals from MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switches, seismic trips and time under vacuum trips.

  4. Vacuum leak detection for double bottom tanks

    SciTech Connect

    Hagen, T.; Rials, R.

    1995-12-31

    Double bottom tanks offer strong leak detection advantages. By incorporating the use of vacuum detection between the two bottoms, the tank bottoms can be verified leak free after construction and during tank use. Utilizing vacuum leak detection requires special considerations. In 1992 a tank construction company built 10 tanks for an oil company in Ponca City, Oklahoma. Each of these tanks were built with a double bottom. This paper provides insight into the planning, construction and testing of this type of double bottom design.

  5. Too much vacuum-assisted closure.

    PubMed

    Dieu, Tam; Leung, Michael; Leong, James; Morrison, Wayne; Cleland, Heather; Archer, Brett; Oppy, Andrew

    2003-12-01

    There has been an explosion in the use of the vacuum-assisted closure device since 1997. Selectively and judiciously used, it is a valuable tool. However, we are concerned by the expanding list of 'indications' for its use. Prolonged applications, frequently several weeks, at the expense of early surgical reconstruction, might compromise the outcome in selected cases. We report four cases that illustrate this problem and stress the importance of timely surgical reconstruction utilizing the range of reconstructive techniques available as well as vacuum-assisted closure dressing.

  6. Structural Analysis of the NCSX Vacuum Vessel

    SciTech Connect

    Fred Dahlgren; Art Brooks; Paul Goranson; Mike Cole; Peter Titus

    2004-09-28

    The NCSX (National Compact Stellarator Experiment) vacuum vessel has a rather unique shape being very closely coupled topologically to the three-fold stellarator symmetry of the plasma it contains. This shape does not permit the use of the common forms of pressure vessel analysis and necessitates the reliance on finite element analysis. The current paper describes the NCSX vacuum vessel stress analysis including external pressure, thermal, and electro-magnetic loading from internal plasma disruptions and bakeout temperatures of up to 400 degrees centigrade. Buckling and dynamic loading conditions are also considered.

  7. The fate of the Higgs vacuum

    NASA Astrophysics Data System (ADS)

    Burda, Philipp; Gregory, Ruth; Moss, Ian G.

    2016-06-01

    We have recently suggested that tiny black holes can act as nucleation seeds for the decay of the metastable Higgs vacuum. Previous results applied only to the nucleation of thin-wall bubbles, and covered a very small region of parameter space. This paper considers bubbles of arbitrary profile and reaches the same conclusion: black holes seed rapid vacuum decay. Seeded and unseeded nucleation rates are compared, and the gravitational back reaction of the bubbles is taken into account. The evolution of the bubble interior is described for the unseeded nucleation. Results are presented for the renormalisation group improved Standard Model Higgs potential, and a simple effective model representing new physics.

  8. MEMS ion-sorption high vacuum pump

    NASA Astrophysics Data System (ADS)

    Grzebyk, T.; Knapkiewicz, P.; Szyszka, P.; Gorecka-Drzazga, A.; Dziuban, J. A.

    2016-11-01

    In the article a miniature MEMS-type ion-sorption vacuum pump has been presented. The influence of electric and magnetic field, as well as horizontal and vertical dimensions of the micropump and type of material used for electrodes on the pump properties has been investigated. It has been found that the micropump works efficiently as long as the magnetic field is higher than 0.3 T, and pumping cell is larger than 1x1x1 mm3. The pump allows generating vacuum at the level of 10-7-10-9 hPa in 100 mm3 volume.

  9. Evaluation of Dry, Rough Vacuum Pumps

    NASA Technical Reports Server (NTRS)

    Hunter, Brian

    2006-01-01

    This document provides information on the testing and evaluation of thirteen dry rough vacuum pumps of various designs and from various manufacturers. Several types of rough vacuum pumps were evaluated, including scroll, roots, and diaphragm pumps. Tests included long term testing, speed curve generation, voltage variance, vibrations emissions and susceptibility, electromagnetic interference emissions and susceptibility, static leak rate, exhaust restriction, response/recovery time tests, and a contamination analysis for scroll pumps. Parameters were found for operation with helium, which often is not provided from the manufacturer

  10. Higgs vacuum stability and modified chaotic inflation

    NASA Astrophysics Data System (ADS)

    Saha, Abhijit Kumar; Sil, Arunansu

    2017-02-01

    The issue of electroweak vacuum stability is studied in presence of a scalar field which participates in modifying the minimal chaotic inflation model. It is shown that the threshold effect on the Higgs quartic coupling originating from the Higgs-inflaton sector interaction can essentially make the electroweak vacuum stable up to the Planck scale. On the other hand we observe that the new physics parameters in this combined framework are enough to provide deviation from the minimal chaotic inflation predictions so as to keep it consistent with recent observation by Planck 2015.

  11. [Vacuum-assisted Therapy in Vascular Surgery].

    PubMed

    Heller, G; Savolainen, H; Widmer, M K; Makaloski, V; Menth, M; Schmidli, J

    2004-05-01

    Since the first use of vacuum-assisted therapy (V.A.C.) in wound care, the indications of this therapy have rapidly expanded. Vascular surgery presents many types of problematic wounds. In the current cost conscious atmosphere, there is a great demand for simple and effective therapies. The V.A.C. system has a lot of potential in the management of vascular wounds. In this article we present indications for vacuum-assisted therapy in vascular surgery: chronic leg ulcers, mesh skin graft, wound care after fasciotomy for compartment syndrome, problematic inguinal wound, false aneurysms, diabetic foot gangrene and amputations with marginal circulations.

  12. Vacuum distillation/vapor filtration water recovery

    NASA Technical Reports Server (NTRS)

    Honegger, R. J.; Neveril, R. B.; Remus, G. A.

    1974-01-01

    The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

  13. Contrived Vacuum Impedances in the Triplet Cryostat

    SciTech Connect

    Welch, Kimo M.

    1995-07-05

    The longitudinal vacuum conductance of cryostats housing standard dipoles and CQS magnet assemblies is such that one is able to sue pressure differences between interconnects, created by external pumping, to resolve the location of He leaks into the cryostat to within one magnet interconnect. The large diameter of the RHIC triplet cryostat precludes exploiting its longitudinal conductance for the same purpose. Because of this, a baffle is being designed to partition the cryostat vacuum envelop, and thus add better resolution to the location of possible He leaks. The method is given for calculating the needed impedance of this baffle.

  14. The QCD vacuum probed by overlap fermions

    NASA Astrophysics Data System (ADS)

    Weinberg, Volker

    2006-12-01

    We summarize different uses of the eigenmodes of the Neuberger overlap operator for the analysis of the QCD vacuum, here applied to quenched configurations simulated by means of the Lüscher-Weisz action. We describe the localization and chiral properties of the lowest modes. The overlap-based topological charge density (with and without UV-filtering) is compared with the re- sults of UV-filtering for the field strength tensor. The latter allows to identify domains of good (anti-)selfduality. All these techniques together lead to a dual picture of the vacuum, unifying the infrared instanton picture with the presence of singular defects co-existent at different scales.

  15. Energy Saving in Thermal Vacuum Test

    NASA Astrophysics Data System (ADS)

    Ascani, M.

    2004-08-01

    When the shrouds of a thermal vacuum chamber must reach temperatures lower than 200 K, the thermoregulation of these ones is usually carried out by the circulation of gaseous nitrogen or flooding with liquid nitrogen; in this second case, using heaters (calrod), it is possible to modulate the thermal flow. Both modes imply a high consumption of liquid nitrogen and of power energy. It is explained a modality of test performed with a thermal vacuum chamber that permits a considerable energy saving compared to the tests available. Following we will call this modality as partially flooded mode.

  16. A vacuum spacetime with closed null geodesics

    SciTech Connect

    Sarma, Debojit Patgiri, Mahadev Ahmed, Faiz Uddin

    2013-02-15

    Here we present a vacuum spacetime with closed null geodesics (CNGs). These CNGs are obtained by analytically solving the geodesic equations. This spacetime is locally isometric to the plane wave spacetime and has very different global properties from metrics of the latter type. - Highlights: Black-Right-Pointing-Pointer Closed null geodesics are found in a vacuum spacetime. Black-Right-Pointing-Pointer These are obtained by analytically solving the geodesic equations. Black-Right-Pointing-Pointer The nature of the spacetime is fully analysed.

  17. Very high-vacuum heat treatment facility

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Moody, M. V.; Richard, J.-P.

    1987-01-01

    A vacuum heat treatment facility, with hot zone dimensions of 12 x 19 x 19 cm, has been designed and constructed at a cost substantially below that of a commercial unit. The design incorporates efficient water cooling and a resistive heating element. A vacuum pressure of 1.5 x 10 to the -8th torr at room temperature has been obtained after baking. The temperature limit is approximately 1900 C. This limit results from the choice of niobium as the hot zone material.

  18. Manifestly Local Theory of Vacuum Energy Sequestering.

    PubMed

    Kaloper, Nemanja; Padilla, Antonio; Stefanyszyn, David; Zahariade, George

    2016-02-05

    We present a manifestly local, diffeomorphism invariant, and locally Poincaré invariant formulation of vacuum energy sequestering. In this theory, quantum vacuum energy generated by matter loops is canceled by auxiliary fields. The auxiliary fields decouple from gravity almost completely. Their only residual effect is an a priori arbitrary, finite contribution to the curvature of the background geometry, which is radiatively stable. Its value is to be determined by a measurement, like the finite part of any radiatively stable UV-sensitive quantity in quantum field theory.

  19. Remote vacuum compaction of compressible hazardous waste

    DOEpatents

    Coyne, Martin J.; Fiscus, Gregory M.; Sammel, Alfred G.

    1998-01-01

    A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

  20. Very high-vacuum heat treatment facility

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Moody, M. V.; Richard, J.-P.

    1987-01-01

    A vacuum heat treatment facility, with hot zone dimensions of 12 x 19 x 19 cm, has been designed and constructed at a cost substantially below that of a commercial unit. The design incorporates efficient water cooling and a resistive heating element. A vacuum pressure of 1.5 x 10 to the -8th torr at room temperature has been obtained after baking. The temperature limit is approximately 1900 C. This limit results from the choice of niobium as the hot zone material.

  1. Lightweight Vacuum Jacket for Cryogenic Insulation. Volume 1

    NASA Technical Reports Server (NTRS)

    Barclay, D. L.; Bell, J. E.; Brogren, E. W.; Straayer, J. W.

    1975-01-01

    The feasibility of producing a lightweight vacuum jacket using state-of-the-art technology and materials was examined. Design and analytical studies were made on a full-scale, orbital maneuvering system fuel tank. Preliminary design details were made for the tank assembly, including an optimized vacuum jacket and multilayer insulation system. A half-scale LH2 test model was designed and fabricated, and a force/stiffness proof test was conducted on the vacuum jacket. A vacuum leak rate of .000001 atmosphere ml of helium per second was measured, approximately 1500 hours of vacuum pressure were sustained, and 29 vacuum-pressure cycles were experienced prior to failure.

  2. Composite drying with simultaneous vacuum and toggling

    USDA-ARS?s Scientific Manuscript database

    Drying is an important mechanical operation in the leather making process. Leather acquires its final texture, consistency and flexibility in the drying operation. Vacuum drying offers fast water removal at a low temperature, which is particularly advantageous to heat-vulnerable chrome-free leathe...

  3. Nonlinear quantum electrodynamics in vacuum and plasmas

    SciTech Connect

    Brodin, Gert; Lundin, Joakim; Marklund, Mattias

    2010-12-14

    We consider high field physics due to quantum electrodynamics, in particular those that can be studied in the next generation of laser facilities. Effective field theories based on the Euler-Heisenberg Lagrangian are briefly reviewed, and examples involving plasma- and vacuum physics are given.

  4. Vacuum plasma coatings for turbine blades

    NASA Technical Reports Server (NTRS)

    Holmes, R. R.

    1985-01-01

    Turbine blades, vacuum plasma spray coated with NiCrAlY, CoCrAlY or NiCrAlY/Cr2O3, were evaluated and rated superior to standard space shuttle main engine (SSME) coated blades. Ratings were based primarily on 25 thermal cycles in the MSFC Burner Rig Tester, cycling between 1700 F (gaseous H2) and -423 F (liquid H2). These tests showed no spalling on blades with improved vacuum plasma coatings, while standard blades spalled. Thermal barrier coatings of ZrO2, while superior to standard coatings, lacked the overall performance desired. Fatigue and tensile specimens, machined from MAR-M-246(Hf) test bars identical to the blades were vacuum plasma spray coated, diffusion bond treated, and tested to qualify the vacuum plasma spray process for flight hardware testing and application. While NiCrAlY/Cr2O3 offers significant improvement over standard coatings in durability and thermal protection, studies continue with an objective to develop coatings offering even greater improvements.

  5. A High Vacuum High Speed Ion Pump

    DOE R&D Accomplishments Database

    Foster, J. S. Jr.; Lawrence, E. O.; Lofgren, E. J.

    1952-08-27

    A vacuum pump based on the properties of a magnetically collimated electric discharge is described. It has a speed in the range 3000 to 7000 liters a second and a base pressure in the order of 10{sup -6} mm. (auth)

  6. Vacuum Flushing of Sewer Solids (Slides)

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  7. Laser Vacuum Furnace for Zone Refining

    NASA Technical Reports Server (NTRS)

    Griner, D. B.; Zurburg, F. W.; Penn, W. M.

    1986-01-01

    Laser beam scanned to produce moving melt zone. Experimental laser vacuum furnace scans crystalline wafer with high-power CO2-laser beam to generate precise melt zone with precise control of temperature gradients around zone. Intended for zone refining of silicon or other semiconductors in low gravity, apparatus used in normal gravity.

  8. Friction, wear, and lubrication in vacuum

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1971-01-01

    A review of studies and observations on the friction, wear, and lubrication behavior of materials in a vacuum environment is presented. The factors that determine and influence friction and wear are discussed. They include topographical, physical, mechanical, and the chemical nature of the surface. The effects of bulk properties such as deformation characteristics, fracture behavior, and structure are included.

  9. Gravity and the quantum vacuum inertia hypothesis

    NASA Astrophysics Data System (ADS)

    Rueda, A.; Haisch, B.

    2005-08-01

    In previous work it has been shown that the electromagnetic quantum vacuum, or electromagnetic zero-point field, makes a contribution to the inertial reaction force on an accelerated object. We show that the result for inertial mass can be extended to passive gravitational mass. As a consequence the weak equivalence principle, which equates inertial to passive gravitational mass, appears to be explainable. This in turn leads to a straightforward derivation of the classical Newtonian gravitational force. We call the inertia and gravitation connection with the vacuum fields the quantum vacuum inertia hypothesis. To date only the electromagnetic field has been considered. It remains to extend the hypothesis to the effects of the vacuum fields of the other interactions. We propose an idealized experiment involving a cavity resonator which, in principle, would test the hypothesis for the simple case in which only electromagnetic interactions are involved. This test also suggests a basis for the free parameter () which we have previously defined to parametrize the interaction between charge and the electromagnetic zero-point field contributing to the inertial mass of a particle or object.

  10. Upgrade of Vacuum Control System on EAST

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Zhang, Y.; Yang, D. W.; Wang, L.; Hu, J. S.; Li, J. H.; Wu, J. H.; Wang, X. M.; EAST vacuum Group

    Experimental Advanced Superconducting Tokamak (EAST) is the first whole superconducting tokamak with divertor configuration in the world [3]. Vacuum system is one of the most important sub-systems of Tokmak device. Therefore, a stable and reliable control system for vacuum operation is required essentially during the plasma discharges. The vacuum control system (VCS) was built preliminarily in 2006. As the new requirements for the vacuum operation is proposed, it is developed and expanded continually. At present the control system has consisted of gas sub-system, pump sub-system, measurement sub-system, wall conditioning sub-system, operator workstation, monitor workstation, database and web publish platform. Comparing to the preliminary one, the whole VCS have been restored and expanded except for reserving the PLCs hardware on the basic level. This paper will present the improvement on the VCS of 2006 and the advantages of the upgrade version, Meanwhile, the new techniques of AJAX (Asynchronous JavaScript and XML) and SVG (Scalable Vector Graphics) will be introduced, which is applied to the user interface at the first time.

  11. Design of the EBIS vacuum system

    SciTech Connect

    Mapes, M.; Smart, L.; Weiss, D.

    2011-03-28

    At Brookhaven National Laboratory the Electron Beam Ion Source (EBIS) is presently being commissioned. The EBIS will be a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC). The new preinjector has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium. The background pressure in the ionization region of the EBIS required to be low enough that it does not produce a significant number of ions from background gas. The pressure in the regions of the electron gun and electron collector can be higher than in the ionization region provided there is efficient vacuum separation between the sections. For injection the ions must be accelerated to 100KV by pulsing the EBIS platform. All associated equipment including the vacuum equipment on the platform is at a 100KV potential. The vacuum system design and the vacuum controls for the EBIS platform and transport system will be presented as well as the interface with the Booster Ring which has a pressure 10-11 Torr.

  12. Automated semiconductor vacuum chemical vapor deposition facility

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A semiconductor vacuum chemical vapor deposition facility (totally automatic) was developed. Wafers arrived on an air track, automatically loaded into a furnace tube, processed, returned to the track, and sent on to the next operation. The entire process was controlled by a computer.

  13. Control and Operational Models for Vacuum Equipment

    NASA Astrophysics Data System (ADS)

    Strubin, P.; Trofimov, N.

    1997-05-01

    Operational models which describe the behaviour and the physical values associated with the vacuum equipment as seen by an operator have been studied for some time at CERN. Recently, they have been completed by control models, which define in a formal way the data structures required to access the physical values described in the operational model. The control models also define the operations that an application program has to send to the vacuum equipment to modify its state. Object Modelling Techniques (OMT) have been used to formalise the description of the models. In order to test the validity of the concepts, we have made a working prototype in the LEP accelerator. This prototype is being built on top of the CERN SL-Equip equipment access package and uses the "cdev" C++ library, developed at TJNAF, for the interface to application programs. SL-Equip is used for data transmission between front-end computers and vacuum equipment. We use the "cdev" networking facilities to communicate between the workstation and the front-end computers, and the "cdev" generic server as the framework for implementing the vacuum controls software. These packages were used in order to minimise the required software investment, but also to prove that these models are hardware and software independent.

  14. Various unique vacuum holders. [For glassblowing

    SciTech Connect

    Gregar, J.S.

    1992-01-01

    Glassblowers use vacuum holding devices to support a flat plate in the glassflowing lathe to seal onto the end of, or inside of, a glass cylinder. Glassblowing blowhose swivels tend to leak; a rotating union from the hydraulics industry is better. Various graphite holder designs are described.

  15. Implementation of Vacuum Region in NIMROD

    NASA Astrophysics Data System (ADS)

    Kruger, Scott; Sovinec, Carl

    1999-11-01

    MHD stability limits in experiments depend on the presence of a vacuum region and on the location of a (geometrically-complicated) conducting wall. Unlike linear codes where one can use Green's functions to predict the response of a fixed plasma-vacuum boundary, the implementation of a vacuum region in a nonlinear initial-value code with a moving plasma-vacuum boundary presents many challenges. We review these challenges and present a practical model for the vaccum region for initial-value codes. We discuss the implementation of this model in the NIMROD code, which was programmed using a finite-element method in order to handle the complicated geometry of modern experiments, and the benchmarking of the NIMROD code to linear analytic results [1] and to the GATO [2] code. Plans to extend this work to nonlinear regimes and to compare with previous nonlinear results [3] will be discussed. ------- [1] V.D. Shafranov, Soviet Physics Technical Physics 15 (1970) 175 [2] L.C. Bernard et.al, Comp. Phys. Comm. 24 (1981) 377 [3] A. Y Aydemir, et al., Bull. Am. Phys. Soc., 43, 1747 (1998).

  16. Vacuum Pyrolysis and Related ISRU Techniques

    NASA Technical Reports Server (NTRS)

    Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

    2007-01-01

    A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, process modeling, parts manufacturing, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a approx. l square meter Fresnel lens. This system was successfully used to vaporize quantities of approx. lg, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system With a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of approx. 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

  17. Vacuum test fixture improves leakage rate measurements

    NASA Technical Reports Server (NTRS)

    Maier, H.; Marx, H.

    1966-01-01

    Cylindrical chamber, consisting of two matching halves, forms a vacuum test fixture for measuring leakage rates of individual connections, brazed joints, and entrance ports used in closed fluid flow line systems. Once the chamber has been sufficiently evacuated, atmospheric pressure holds the two halves together.

  18. Semiclassical approach to heterogeneous vacuum decay

    NASA Astrophysics Data System (ADS)

    Grinstein, Benjamín; Murphy, Christopher W.

    2015-12-01

    We derive the decay rate of an unstable phase of a quantum field theory in the presence of an impurity in the thin-wall approximation. This derivation is based on the how the impurity changes the (flat spacetime) geometry relative to case of pure false vacuum. Two examples are given that show how to estimate some of the additional parameters that enter into this heterogeneous decay rate. This formalism is then applied to the Higgs vacuum of the Standard Model (SM), where baryonic matter acts as an impurity in the electroweak Higgs vacuum. We find that the probability for heterogeneous vacuum decay to occur is suppressed with respect to the homogeneous case. That is to say, the conclusions drawn from the homogeneous case are not modified by the inclusion of baryonic matter in the calculation. On the other hand, we show that Beyond the Standard Model physics with a characteristic scale comparable to the scale that governs the homogeneous decay rate in the SM, can in principle lead to an enhanced decay rate.

  19. Thick tellurium target preparation by vacuum deposition

    NASA Astrophysics Data System (ADS)

    Stolarz, Anna

    1999-12-01

    Tellurium targets of thickness up to 6.5 mg/cm 2 on carbon backings were prepared by vacuum deposition. The influence of the crucible dimension, treatment of the backing foil by glow discharge and substrate cooling on the Te sticking efficiency was studied in order to achieve the best yield.

  20. Vacuum statistics and stability in axionic landscapes

    SciTech Connect

    Masoumi, Ali; Vilenkin, Alexander E-mail: vilenkin@cosmos.phy.tufts.edu

    2016-03-01

    We investigate vacuum statistics and stability in random axionic landscapes. For this purpose we developed an algorithm for a quick evaluation of the tunneling action, which in most cases is accurate within 10%. We find that stability of a vacuum is strongly correlated with its energy density, with lifetime rapidly growing as the energy density is decreased. On the other hand, the probability P(B) for a vacuum to have a tunneling action B greater than a given value declines as a slow power law in B. This is in sharp contrast with the studies of random quartic potentials, which found a fast exponential decline of P(B). Our results suggest that the total number of relatively stable vacua (say, with B>100) grows exponentially with the number of fields N and can get extremely large for N∼> 100. The problem with this kind of model is that the stable vacua are concentrated near the absolute minimum of the potential, so the observed value of the cosmological constant cannot be explained without fine-tuning. To address this difficulty, we consider a modification of the model, where the axions acquire a quadratic mass term, due to their mixing with 4-form fields. This results in a larger landscape with a much broader distribution of vacuum energies. The number of relatively stable vacua in such models can still be extremely large.

  1. Vacuum fusion bonding of glass plates

    DOEpatents

    Swierkowski, Steve P.; Davidson, James C.; Balch, Joseph W.

    2001-01-01

    An improved apparatus and method for vacuum fusion bonding of large, patterned glass plates. One or both glass plates are patterned with etched features such as microstructure capillaries and a vacuum pumpout moat, with one plate having at least one hole therethrough for communication with a vacuum pumpout fixture. High accuracy alignment of the plates is accomplished by a temporary clamping fixture until the start of the fusion bonding heat cycle. A complete, void-free fusion bond of seamless, full-strength quality is obtained through the plates; because the glass is heated well into its softening point and because of a large, distributed force that is developed that presses the two plates together from the difference in pressure between the furnace ambient (high pressure) and the channeling and microstructures in the plates (low pressure) due to the vacuum drawn. The apparatus and method may be used to fabricate microcapillary arrays for chemical electrophoresis; for example, any apparatus using a network of microfluidic channels embedded between plates of glass or similar moderate melting point substrates with a gradual softening point curve, or for assembly of glass-based substrates onto larger substrates, such as in flat panel display systems.

  2. Vacuum fusion bonding of glass plates

    DOEpatents

    Swierkowski, Steve P.; Davidson, James C.; Balch, Joseph W.

    2000-01-01

    An improved apparatus and method for vacuum fusion bonding of large, patterned glass plates. One or both glass plates are patterned with etched features such as microstructure capillaries and a vacuum pumpout moat, with one plate having at least one hole therethrough for communication with a vacuum pumpout fixture. High accuracy alignment of the plates is accomplished by a temporary clamping fixture until the start of the fusion bonding heat cycle. A complete, void-free fusion bond of seamless, full-strength quality is obtained through the plates; because the glass is heated well into its softening point and because of a large, distributed force that is developed that presses the two plates together from the difference in pressure between the furnace ambient (high pressure) and the channeling and microstructures in the plates (low pressure) due to the vacuum drawn. The apparatus and method may be used to fabricate microcapillary arrays for chemical electrophoresis; for example, any apparatus using a network of microfluidic channels embedded between plates of glass or similar moderate melting point substrates with a gradual softening point curve, or for assembly of glass-based substrates onto larger substrates, such as in flat panel display systems.

  3. Characterization of Venezuelan heavy oil vacuum residua

    SciTech Connect

    Izquierdo, A.; Carbognani, L.; Leon, V.; Parisi, A. )

    1989-01-01

    Vacuum residua from Venezuela heavy and medium oils upgraded under the same conditions were characterized using different analytical techniques: TLC-FID, H NMR, HPLC, SEC-DCP. Parameters or chemical properties such as crude maturity, size distribution of hydrocarbons and metal compounds, asphaltene characteristics, sulphur contents, correlate with the processability of these heavy ends.

  4. Vacuum-Ultraviolet Intensity-Calibration Standard

    NASA Technical Reports Server (NTRS)

    Ajello, J. M.; Franklin, B. O.

    1986-01-01

    Portable light source enables calibration of spectrometers. Vacuum Ultraviolet Light (40 to 200 nm) produced in electron-impact emission chamber by leading beam of gas across electron beam. Photons observed at right angles to electron-beam axis. Previously, there were blackbody standards in visible and near ultraviolet, but no intensity-calibration standards in VUV.

  5. Vacuum storage of yellow-poplar pollen

    Treesearch

    James R. Wilcox

    1966-01-01

    Vacuum-drying, followed by storage in vacuo or in an inert gas, is effective for storing pollen of many species. It permits storage at room environments without rigid controls of either temperature or humidity, an advantage that becomes paramount during long-distance transfers of pollen when critical storage conditions are impossible to maintain. In...

  6. MFTF vacuum vessel and cryopumping system

    SciTech Connect

    Valby, L.E.; Pittenger, L.C.

    1980-10-13

    The Mirror Fusion Test Facility (MFTF) vacuum vessel and cryopumping system have attracted considerable interest within the fusion research community. Their extreme size, coupled with severe performance requirements and unique design features, justifies this interest. The planned expansion of the system to a tandem mirror configuration with thermal barriers further increases the engineering challenges of this complex facility.

  7. Vacuum polarization in a strong external field

    NASA Technical Reports Server (NTRS)

    Soff, Gerhard; Mohr, Peter J.

    1988-01-01

    Vacuum polarization in the field of a high-Z finite-size nucleus is examined, and the polarization charge density in coordinate space of order alpha(Z alpha)exp n not less than 3 is calculated. Energy-level shifts of K- and L-shell electrons in hydrogenlike systems are given.

  8. Vacuum Baking To Remove Volatile Materials

    NASA Technical Reports Server (NTRS)

    Muscari, J. A.

    1985-01-01

    Outgassing reduced in some but not all nonmetallic materials. Eleven polymeric materials tested by determining outgassing species as temperature of conditioned and unconditioned materials raised to 300 degrees C. Conditioning process consisted of vacuum bake for 24 hours at 80 degrees C in addition to usual cure. Baking did not change residual gas percentage of water molecules.

  9. Time-sharing switch for vacuum brazing

    NASA Technical Reports Server (NTRS)

    Stein, J. A.

    1981-01-01

    Switching unit changes power and cooling-water connections between two vacuum-brazing machines. It allows both units to be powered by single radio-frequency (RF) generator. One machine can be used for brazing while bell jar of other is being evacuated (20 minute process) in preparation for brazing or is being cooled after brazing (10 minute process).

  10. The vacuum interaction of magnetic strings

    SciTech Connect

    Bordag, M. )

    1991-03-01

    The author investigates the interaction of two parallel magnetic strings which is due to the perturbation of the vacuum state of a scalar massive field. The Green function with one string is studied in detail and the influence of the second string is found in perturbation theory. The Casimir is expressed in terms of Bessel functions.

  11. Vacuum polarization in a strong external field

    NASA Technical Reports Server (NTRS)

    Soff, Gerhard; Mohr, Peter J.

    1988-01-01

    Vacuum polarization in the field of a high-Z finite-size nucleus is examined, and the polarization charge density in coordinate space of order alpha(Z alpha)exp n not less than 3 is calculated. Energy-level shifts of K- and L-shell electrons in hydrogenlike systems are given.

  12. 242-A evaporator vacuum condenser system

    SciTech Connect

    Smith, V.A.

    1994-09-28

    This document is written for the 242-A evaporator vacuum condenser system (VCS), describing its purpose and operation within the evaporator. The document establishes the operating parameters specifying pressure, temperature, flow rates, interlock safety features and interfacing sub-systems to support its operation.

  13. Vacuum magnetic fields with dense flux surfaces

    SciTech Connect

    Cary, J R

    1982-05-01

    A procedure is given for eliminating resonances and stochasticity in nonaxisymmetric vacuum toroidal magnetic field. The results of this procedure are tested by the surface of section method. It is found that one can obtain magnetic fields with increased rotational transform and decreased island structure while retaining basically the same winding law.

  14. True random numbers from amplified quantum vacuum.

    PubMed

    Jofre, M; Curty, M; Steinlechner, F; Anzolin, G; Torres, J P; Mitchell, M W; Pruneri, V

    2011-10-10

    Random numbers are essential for applications ranging from secure communications to numerical simulation and quantitative finance. Algorithms can rapidly produce pseudo-random outcomes, series of numbers that mimic most properties of true random numbers while quantum random number generators (QRNGs) exploit intrinsic quantum randomness to produce true random numbers. Single-photon QRNGs are conceptually simple but produce few random bits per detection. In contrast, vacuum fluctuations are a vast resource for QRNGs: they are broad-band and thus can encode many random bits per second. Direct recording of vacuum fluctuations is possible, but requires shot-noise-limited detectors, at the cost of bandwidth. We demonstrate efficient conversion of vacuum fluctuations to true random bits using optical amplification of vacuum and interferometry. Using commercially-available optical components we demonstrate a QRNG at a bit rate of 1.11 Gbps. The proposed scheme has the potential to be extended to 10 Gbps and even up to 100 Gbps by taking advantage of high speed modulation sources and detectors for optical fiber telecommunication devices.

  15. Vacuum Baking To Remove Volatile Materials

    NASA Technical Reports Server (NTRS)

    Muscari, J. A.

    1985-01-01

    Outgassing reduced in some but not all nonmetallic materials. Eleven polymeric materials tested by determining outgassing species as temperature of conditioned and unconditioned materials raised to 300 degrees C. Conditioning process consisted of vacuum bake for 24 hours at 80 degrees C in addition to usual cure. Baking did not change residual gas percentage of water molecules.

  16. Vacuum Flushing of Sewer Solids (Slides)

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  17. Investigations Of A Pulsed Cathodic Vacuum Arc

    NASA Astrophysics Data System (ADS)

    Oates, T. W. H.; Pigott, J.; Denniss, P.; Mckenzie, D. R.; Bilek, M. M. M.

    2003-06-01

    Cathodic vacuum arcs are well established as a method for producing thin films for coatings and as a source of metal ions. Research into DC vacuum arcs has been going on for over ten years in the School of Physics at the University of Sydney. Recently a project was undertaken in the school to design and build a pulsed CVA for use in the investigation of plasma sheaths and plasma immersion ion implantation. Pulsed cathodic vacuum arcs generally have a higher current and plasma density and also provide a more stable and reproducible plasma density than their DC counterparts. Additionally it has been shown that if a high repetition frequency can be established the deposition rate of pulsed arcs is equal to or greater than that of DC arcs with a concomitant reduction in the rate of macro-particle formation. We present here results of our investigations into the building of a center-triggered pulsed cathodic vacuum arc. The design of the power supply and trigger mechanism and the geometry of the anode and cathode are examined. Observations of type I and II arc spots using a CCD camera, and cathode spot velocity dependence on arc current will be presented. The role of retrograde motion in a high current pulsed arc is discussed.

  18. Regulating vacuum pump speed with feedback control. Final report

    SciTech Connect

    Ludington, D.C.; Aneshansley, D.J.; Pellerin, R.; Guo, F.

    1992-01-01

    Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m{sup 3}/min or cfm) of the vacuum pump always exceeds the capacity needed to milk cows and wash pipelines. Vacuum pumps run at full speed and load regardless of actual need for air. Excess air is admitted through a controller. Energy can be saved from electrical demand reduced by regulating vacuum pump speed according to air based on air usage. An adjustable speed drive (ASD) on the motor and controlled based upon air usage, can reduce the energy used by the vacuum pump. However, the ASD unit tested could not maintain vacuum levels within generally accepted guidelines when air usage changed. Adding a high vacuum reserve and a dual vacuum controller between the vacuum pump and the milking pipeline brought vacuum stability within guidelines. The ASD/dual vacuum system can reduce energy consumption and demand by at least 50 percent during milking and provide better vacuum stability than conventional systems. Tests were not run during washing cycles. Using 1990 costs and only the energy saved during milking, the simple payback on investment in new equipment for a 5 hp motor, speed controller and vacuum regulator would be about 5 years.

  19. Nearly Seamless Vacuum-Insulated Boxes

    NASA Technical Reports Server (NTRS)

    Stepanian, Christopher J.; Ou, Danny; Hu, Xiangjun

    2010-01-01

    A design concept, and a fabrication process that would implement the design concept, have been proposed for nearly seamless vacuum-insulated boxes that could be the main structural components of a variety of controlled-temperature containers, including common household refrigerators and insulating containers for shipping foods. In a typical case, a vacuum-insulated box would be shaped like a rectangular parallelepiped conventional refrigerator box having five fully closed sides and a hinged door on the sixth side. Although it is possible to construct the five-closed-side portion of the box as an assembly of five unitary vacuum-insulated panels, it is not desirable to do so because the relatively high thermal conductances of the seams between the panels would contribute significant amounts of heat leakage, relative to the leakage through the panels themselves. In contrast, the proposal would make it possible to reduce heat leakage by constructing the five-closed-side portion of the box plus the stationary portion (if any) of the sixth side as a single, seamless unit; the only remaining seam would be the edge seal around the door. The basic cross-sectional configuration of each side of a vacuum-insulated box according to the proposal would be that of a conventional vacuum-insulated panel: a low-density, porous core material filling a partially evacuated space between face sheets. However, neither the face sheets nor the core would be conventional. The face sheets would be opposite sides of a vacuum bag. The core material would be a flexible polymer-modified silica aerogel of the type described in Silica/Polymer and Silica/Polymer/Fiber Composite Aero - gels (MSC-23736) in this issue of NASA Tech Briefs. As noted in that article, the stiffness of this core material against compression is greater than that of prior aerogels. This is an important advantage because it translates to greater retention of thickness and, hence, of insulation performance when pressure is

  20. Spent nuclear fuel project cold vacuum drying facility vacuum and purge system design description

    SciTech Connect

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Vacuum and Purge System (VPS) . The SDD was developed in conjunction with HNF-SD-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-002, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the VPS equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  1. 21 CFR 884.4340 - Fetal vacuum extractor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... facilitate delivery. The device enables traction to be applied to the fetal head (in the birth canal) by... type of device may include the cup, hosing, vacuum source, and vacuum control. (b) Classification...

  2. 21 CFR 884.4340 - Fetal vacuum extractor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... facilitate delivery. The device enables traction to be applied to the fetal head (in the birth canal) by... type of device may include the cup, hosing, vacuum source, and vacuum control. (b) Classification...

  3. Feed-through connector withstands high temperatures in vacuum environment

    NASA Technical Reports Server (NTRS)

    Kreisman, W. S.

    1965-01-01

    Feed-through connector with sealing action augmented by any temperature increase can be used through the wall of a vacuum device. It retains vacuum integrity through successive cycles of high temperature.

  4. Vacuum Chamber Documentation for U of H Collection

    NASA Image and Video Library

    2006-06-16

    Documentation for the University of Houston (UH) Clear Lake collection of their library books after the Vacuum Chamber runs were performed to remove the water from them. Vacuum Chamber B in Building 32 was used.

  5. DC photogun vacuum characterization through photocathode lifetime studies

    SciTech Connect

    Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

    2007-07-02

    Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated.

  6. HOM Effects in Vacuum System with Short Bunches

    SciTech Connect

    Novokhatski, A.; /SLAC

    2005-06-10

    High luminosity in electron-positron factories requires high currents of very short bunches. SLAC PEP-II and KEKB B-factories are progressively increasing currents gaining more and more luminosity [1-2]. Simultaneously the interaction of high currents and vacuum chamber elements becomes more important for operation of the rings. High Order Modes excited by short intense bunches are propagating along the vacuum chamber, penetrating and dissipating inside vital vacuum elements, like shielded bellows, vacuum valves and vacuum pump. As a result, these elements get large temperature rise or temperature oscillations. Often HOM heating has a resonance character. HOM heating of vacuum pumps leads to increasing of the vacuum pressure. High frequency modes ''check'' the quality of vacuum chamber: they detect small gaps, weak RF screens or feed-through. Smooth tapers and collimators become the source of HOM production. We will discuss the physical nature of these exciting HOM effects.

  7. Vacuum technology /2nd revised and enlarged edition/

    NASA Astrophysics Data System (ADS)

    Roth, A.

    Principles and phenomena germane to the field of vacuum technology are dealt with in the book. Natural and artificial vacuums are discussed, together with the history of vacuum technology development. Various factors and laws defining the content of rarefied gas theory are reviewed. Typical flows encountered in gas at low pressures are examined, as are calculations appropriate to vacuum situations. Attention is given to the physical and chemical phenomena observed in vacuum techniques, and methods and equipment for producing low pressure conditions are explored, noting the various types of pumps employed to approximate a vacuum. Calibration of instruments and the measurement of vacuums and partial pressures are considered. Finally, the techniques, vessels, cleaning procedures, and sealing methods for producing a clean vacuum are described.

  8. Ionization vacuum gage starts quickly, is unaffected by spurious currents

    NASA Technical Reports Server (NTRS)

    Garwood, D. C.

    1965-01-01

    Ionization vacuum gage with a switch-operated starting device and a microammeter begins functioning quickly in a high vacuum. The microammeter is also protected by its circuit design from spurious currents.

  9. Healthier Americans

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency (EPA) has proposed Mercury and Air Toxics Standards (MATS) for power plants to limit mercury, acid gases and other toxic pollution from power plants. This page is about effects on health of Americans.

  10. American ginseng

    MedlinePlus

    ... and inflammation of the lining of the stomach (gastritis). American ginseng is also used for low iron ... Anemia. Bleeding disorders. Digestive disorders. Dizziness. Fever. Fibromyalgia. Gastritis. Hangover symptoms. Headaches. HIV/AIDS. Impotence. Insomnia. Memory ...

  11. 46 CFR 64.65 - Vacuum relief device.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Vacuum relief device. 64.65 Section 64.65 Shipping COAST... HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.65 Vacuum relief device. (a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a...

  12. 46 CFR 154.1335 - Pressure and vacuum protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Pressure and vacuum protection. 154.1335 Section 154... Equipment Instrumentation § 154.1335 Pressure and vacuum protection. (a) Each cargo tank must have the...) Has remote readouts at the cargo control station. (2) If vacuum protection is required under §...

  13. 7 CFR 58.913 - Evaporators and vacuum pans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans....

  14. 46 CFR 64.65 - Vacuum relief device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Vacuum relief device. 64.65 Section 64.65 Shipping COAST... HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.65 Vacuum relief device. (a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a...

  15. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  16. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  17. 7 CFR 58.913 - Evaporators and vacuum pans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans....

  18. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  19. 7 CFR 58.913 - Evaporators and vacuum pans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans....

  20. 7 CFR 58.913 - Evaporators and vacuum pans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans....

  1. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  2. 46 CFR 64.65 - Vacuum relief device.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Vacuum relief device. 64.65 Section 64.65 Shipping COAST... HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.65 Vacuum relief device. (a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a...

  3. 46 CFR 64.65 - Vacuum relief device.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Vacuum relief device. 64.65 Section 64.65 Shipping COAST... HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.65 Vacuum relief device. (a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a...

  4. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  5. 46 CFR 64.65 - Vacuum relief device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Vacuum relief device. 64.65 Section 64.65 Shipping COAST... HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.65 Vacuum relief device. (a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a...

  6. 7 CFR 305.29 - Vacuum heat treatment schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Vacuum heat treatment schedule. 305.29 Section 305.29... SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.29 Vacuum heat treatment schedule. T111-a-1. Place bay leaves in a vacuum chamber. Starting at 0 hour, gradually reduce to 0.133...

  7. 7 CFR 58.913 - Evaporators and vacuum pans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans....

  8. Feed-through connector couples RF power into vacuum chamber

    NASA Technical Reports Server (NTRS)

    Grandy, G. L.

    1967-01-01

    Feed-through device connects RF power to an RF coil in a vacuum chamber. The coil and leads are water cooled and vacuum tight seals are provided at the junctions. The device incorporates silver soldered copper tubes, polytetrafluoroethylene electrical insulators, and O-ring vacuum seals.

  9. Vacuum Surface Flashover And High Pressure Gas Streamers

    DTIC Science & Technology

    1997-06-01

    Optical Emission Characteristics of Polycrystalline Diamond During Surface Flashover in Vacuum ," 1996 IEEE 1~ International Symposium on... VACUUM SURFACE FLASHOVER AND HIGH PRESSURE GAS STREAMERS J. M. Elizondo, M. L. Krogh, D. Smith, D. Stoltz, and S. N. Wright AlliedSignal Federal...breakdown current traces obtained during high pressure gas breakdown and vacuum surface flashover show similar signatures. The initial

  10. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and...

  11. Vacuum transfer system increases sugar maple sap yield

    Treesearch

    Russell S. Walters

    1978-01-01

    Yields of sugar maple sap collected from three plastic pipeline systems by gravity, vacuum pump, and a vacuum pump with a transfer tank were compared during 2 years in northern Vermont. The transfer system yielded 27 percent more sap one year and 17 percent more the next year. Higher vacuum levels at the tapholes were observed in the transfer system.

  12. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and maintained...

  13. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and maintained...

  14. 21 CFR 884.5070 - Vacuum abortion system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  15. 21 CFR 884.5070 - Vacuum abortion system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  16. 21 CFR 884.5070 - Vacuum abortion system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  17. 21 CFR 884.5070 - Vacuum abortion system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  18. 21 CFR 884.5070 - Vacuum abortion system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  19. 92. VIEW OF PRECIPITATION AREA FROM SOUTHWEST. VACUUM CLARIFIER TANK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. VIEW OF PRECIPITATION AREA FROM SOUTHWEST. VACUUM CLARIFIER TANK No. 1 AT LOWER LEFT, UNDER LAUNDER FEED TO GOLD TANK No. 2, AND VACUUM CLARIFIER TANK No. 2, AT MIDRIGHT. VACUUM RECEIVER TANK ON UPPER LEFT. PIPE TO TOP CENTER OF TANK TAKES OUTFLOW FROM CLARIFIER LEAVES. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  20. Vacuum energy in the bag model

    NASA Astrophysics Data System (ADS)

    Candelas, P.

    1986-04-01

    The vacuum energy of the Yang-Mills field is examined for the conditions of the bag model. The dominance of high-frequency effects results in a vacuum energy that decomposes naturally into a volume energy, a surface energy, and higher shape energies. These quantities are identified with the parameters of the bag model. The imposition of confining boundary conditions for all frequencies is shown to be inconsistent since this would result in the bag constant and certain of the shape tensions being infinite. The manner in which the boundary conditions should be relaxed at high frequency is discussed. The most naive procedure for relaxing the boundary conditions, which is to apply confining conditions only on modes of frequency less than some cutoff frequency, results in a negative bag constant and surface tension and would render the vacuum unstable against the spontaneous breaking of Poincaré invariance. Consideration of the manner by which the interacting electromagnetic field avoids a similar instability suggests that a more realistic way to relax the boundary conditions on the bag surface is to endow the vacuum exterior to the bag with a frequency-dependent dielectric constant and magnetic permeability. In this picture the stability of the vacuum is restored, the surface tension is finite and positive, and the bag constant is zero at least to lowest order in the coupling. It is pointed out that the fermion contributions to the bag constant and the surface tension may relate to the spontaneous breaking of chiral invariance. The aim throughout is to examine the bag model, as it relates to vacuum energy, strictly in its own terms with an emphasis on questions of principle. All too often is heard the alibi that since the theory itself is only approximate, the mathematics need be no better. In truth the opposite follows. Granted that the model represents but a part of nature, we are to find what such an ideal picture implies, a result strictly derived serves to test