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Sample records for surface existing leed

  1. Advances on surface structural determination by LEED

    International Nuclear Information System (INIS)

    Soares, Edmar A; De Carvalho, Vagner E; De Castilho, Caio M C

    2011-01-01

    In the last 40 years, low energy electron diffraction (LEED) has proved to be the most reliable quantitative technique for surface structural determination. In this review, recent developments related to the theory that gives support to LEED structural determination are discussed under a critical analysis of the main theoretical approximation-the muffin-tin calculation. The search methodologies aimed at identifying the best matches between theoretical and experimental intensity versus voltage curves are also considered, with the most recent procedures being reviewed in detail. (topical review)

  2. Application of a LEED apparatus provided with a lens to the study of vicinal surfaces

    International Nuclear Information System (INIS)

    Laydevant, Louis; Dupuy, J.C.

    1979-01-01

    Steps presence on vicinal surfaces changes the low energy electron difraction (LEED) pattern: a system of regulary spaced steps is causing some spots to be splitted. Using a high voltage LEED apparatus allows an easy explanation of the patterns: the spot position does not depend about energy and so some cristallographic parameters can be easily measured [fr

  3. Study of the local structure of binary surfaces by electron diffraction (XPS, LEED)

    OpenAIRE

    Gereová, Katarína

    2006-01-01

    Study of local structure of binary surface with usage of ultra-thin film of cerium deposited on a Pd (111) single-crystal surface is presented. X-ray photoelectron spectroscopy and diffraction (XPS, XPD), angle resolved UV photoemission spectroscopy (ARUPS) and low energy electron diffraction (LEED) was used for our investigations. LEED and X-ray excited photoemission intensities results represent a surface-geometrical structure. As well, mapping of ultra-violet photoelectron intensities as a...

  4. Investigation of reordered (001) Au surfaces by positive ion channeling spectroscopy, LEED and AES

    International Nuclear Information System (INIS)

    Appleton, B.R.; Noggle, T.S.; Miller, J.W.; Schow, O.E. III; Zehner, D.M.; Jenkins, L.H.; Barrett, J.H.

    1974-01-01

    As a consequence of the channeling phenomenon of positive ions in single crystals, the yield of ions Rutherford scattered from an oriented single crystal surface is dependent on the density of surface atoms exposed to the incident ion beam. Thus, the positive ion channeling spectroscopy (PICS) technique should provide a useful tool for studying reordered surfaces. This possibility was explored by examining the surfaces of epitaxially grown thin Au single crystals with the combined techniques of LEED-AES and PICS. The LEED and AES investigations showed that when the (001) surface was sputter cleaned in ultra-high vacuum, the normal (1 x 1) symmetry of the (001) surfaces reordered into a structure which gave a complex (5 x 20) LEED pattern. The yield and energy distributions of 1 MeV He ions scattered from the Au surfaces were used to determine the number of effective monolayers contributing to the normal and reordered surfaces. These combined measurements were used to characterize the nature of the reordered surface. The general applicability of the PICS technique for investigations of surface and near surface regions is discussed

  5. The power of joint application of LEED and DFT in quantitative surface structure determination

    International Nuclear Information System (INIS)

    Heinz, K; Hammer, L; Mueller, S

    2008-01-01

    It is demonstrated for several cases that the joint application of low-energy electron diffraction (LEED) and structural calculations using density functional theory (DFT) can retrieve the correct surface structure even though single application of both methods fails. On the experimental side (LEED) the failure can be due to the simultaneous presence of weak and very strong scatterers or to an insufficient data base leaving different structures with the same quality of fit between experimental data and calculated model intensities. On the theory side (DFT) it can be difficult to predict the coverage of an adsorbate or two different structures may own almost the same total energy, but only one of the structures is assumed in experiment due to formation kinetics. It is demonstrated how in the different cases the joint application of both methods-which yield about the same structural precision-offers a way out of the dilemma

  6. LEED crystallography studies of the structure of clean and adsorbate-covered Ir, Pt and Rh crystal surfaces

    International Nuclear Information System (INIS)

    Koestner, R.J.

    1982-08-01

    There have only been a few Low Energy Electron Diffraction (LEED) intensity analyses carried out to determine the structure of molecules adsorbed on metal surfaces; most surface crystallography studies concentrated on the structure of clean unreconstructed or atomic adsorbate-covered transition metal faces. The few molecular adsorption systems already investigated by dynamical LEED are CO on Ni(100), Cu(100) and Pd(100) as well as C 2 H 2 and C 2 H 4 adsorbed on Pt(111). The emphasis of this thesis research has been to extend the applicability of LEED crystallography to the more complicated unit cells found in molecular overlayers on transition metals or in there constructed surfaces of clean transition metals

  7. LEED crystallography studies of the structure of clean and adsorbate-covered Ir, Pt and Rh crystal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Koestner, R.J.

    1982-08-01

    There have only been a few Low Energy Electron Diffraction (LEED) intensity analyses carried out to determine the structure of molecules adsorbed on metal surfaces; most surface crystallography studies concentrated on the structure of clean unreconstructed or atomic adsorbate-covered transition metal faces. The few molecular adsorption systems already investigated by dynamical LEED are CO on Ni(100), Cu(100) and Pd(100) as well as C/sub 2/H/sub 2/ and C/sub 2/H/sub 4/ adsorbed on Pt(111). The emphasis of this thesis research has been to extend the applicability of LEED crystallography to the more complicated unit cells found in molecular overlayers on transition metals or in there constructed surfaces of clean transition metals.

  8. Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

    International Nuclear Information System (INIS)

    Ogletree, D.F.

    1986-11-01

    LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2√3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (√3 x √3) reconstruction on the (111) face of the α-CuAl alloy has been determined

  9. Extending the range of low energy electron diffraction (LEED) surface structure determination: Co-adsorbed molecules, incommensurate overlayers and alloy surface order studied by new video and electron counting LEED techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ogletree, D.F.

    1986-11-01

    LEED multiple scattering theory is briefly summarized, and aspects of electron scattering with particular significance to experimental measurements such as electron beam coherence, instrument response and phonon scattering are analyzed. Diffuse LEED experiments are discussed. New techniques that enhance the power of LEED are described, including a real-time video image digitizer applied to LEED intensity measurements, along with computer programs to generate I-V curves. The first electron counting LEED detector using a ''wedge and strip'' position sensitive anode and digital electronics is described. This instrument uses picoampere incident beam currents, and its sensitivity is limited only by statistics and counting times. Structural results on new classes of surface systems are presented. The structure of the c(4 x 2) phase of carbon monoxide adsorbed on Pt(111) has been determined, showing that carbon monoxide molecules adsorb in both top and bridge sites, 1.85 +- 0.10 A and 1.55 +- 0.10 A above the metal surface, respectively. The structure of an incommensurate graphite overlayer on Pt(111) is analyzed. The graphite layer is 3.70 +- 0.05 A above the metal surface, with intercalated carbon atoms located 1.25 +- 0.10 A above hollow sites supporting it. The (2..sqrt..3 x 4)-rectangular phase of benzene and carbon monoxide coadsorbed on Pt(111) is analyzed. Benzene molecules adsorb in bridge sites parallel to and 2.10 +- 0.10 A above the surface. The carbon ring is expanded, with an average C-C bond length of 1.72 +- 0.15 A. The carbon monoxide molecules also adsorb in bridge sites. The structure of the (..sqrt..3 x ..sqrt..3) reconstruction on the (111) face of the ..cap alpha..-CuAl alloy has been determined.

  10. Surface structure and electronic states of epitaxial β-FeSi.sub.2./sub.(100)/Si(001) thin films: Combined quantitative LEED, ab initio DFT, and STM study

    Czech Academy of Sciences Publication Activity Database

    Romanyuk, Olexandr; Hattori, K.; Someta, M.; Daimon, H.

    2014-01-01

    Roč. 90, č. 15 (2014), "155305-1"-"155305-9" ISSN 1098-0121 Grant - others:AVČR(CZ) M100101201; Murata Science Foundation(JP) Project n. 00295 Institutional support: RVO:68378271 Keywords : iron silicide * LEED I-V * DFT * STM * surface reconstruction * surface states Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

  11. LEED-IV study of the rutile TiO2(110)-1x2 surface with a Ti-interstitial added-row reconstruction

    International Nuclear Information System (INIS)

    Blanco-Rey, M.; Mendez, J.; Lopez, M. F.; Roman, E.; Martin-Gago, J. A.; Andres, P. L. de; Abad, J.; Rogero, C.

    2007-01-01

    Upon sputtering and annealing in UHV at ∼1000 K, the rutile TiO 2 (110) surface undergoes a 1x1→1x2 phase transition. The resulting 1x2 surface is Ti rich, formed by strands of double Ti rows as seen on scanning tunneling microscopic images, but its detailed structure and composition have been subject to debate in the literature for years. Recently, Park et al. [Phys. Rev. Lett. 96, 226105 (2006)] have proposed a model where Ti atoms are located on interstitial sites with Ti 2 O stoichiometry. This model, when it is analyzed using LEED-IV data [Phys. Rev. Lett. 96, 0055502 (2006)], does not yield an agreement between theory and experiment as good as the previous best fit for Onishi and Iwasawa's model for the long-range 1x2 reconstruction. Therefore, the Ti 2 O 3 added row is the preferred one from the point of view low-energy electron diffraction

  12. Leeds under a cloud

    International Nuclear Information System (INIS)

    1988-01-01

    Before 26 April 1986 few people in the west had heard of Chernobyl. Then Chernobyl experienced the world's worst nuclear power station accident. In the wake of the disaster radioactivity fell on Britain and much of Europe. There was confusion and rumour on the television, in the papers and amongst ordinary people. What would the effect of the Chernobyl accident be? Was it safe to go out of doors? Was it safe to eat fresh vegetables? What was a safe level of radiation? What was a becquerel, a milliSievert or any of the other scientific terms with which we were bombarded by scientists and other experts? This booklet sets out to help answer these questions by looking at a hypothetical disaster at the nuclear power station at Heysham, near Morecambe in Lancashire. Using this scenario it shows what the worst consequences of a nuclear accident might be for the citizens of Leeds. It also explains in a straightforward way the meaning of many technical terms which will help you to understand the advice and comments of experts and to make your own judgement of what they say. (author)

  13. LEED (Low Energy Electron Diffraction)

    International Nuclear Information System (INIS)

    Aberdam, M.

    1973-01-01

    The various types of systems studied by LEED, and for which the geometry of diffraction patterns is exploited, are reviewed, intensity profiles being another source of information. Two representative approaches of the scattering phenomenon are examined; the band structure theory and the T matrix approach [fr

  14. Impact of different LEED versions for green building certification and energy efficiency rating system: A Multifamily Midrise case study

    International Nuclear Information System (INIS)

    Rastogi, Ankush; Choi, Jun-Ki; Hong, Taehoon; Lee, Minhyun

    2017-01-01

    Highlights: •Energy consumption change from applying different LEED versions were investigated. •Four analysis scenarios were compared using different versions of ASHRAE Standard. •A case study of a mid-rise multi-family building was conducted using energy simulation. •Residential buildings could benefit from LEED v4 due to the low prerequisite. •Renovation buildings are highly incentivized regardless of LEED version used. -- Abstract: Various versions of the Leadership in Energy and Environmental Design (LEED ® ) have been introduced with the addition of more stringent sustainability parameters and credit scoring schemes over the past decade. Such changes in LEED versions strongly affect the energy performance and LEED scores of the target building in the LEED certification process. Therefore, to validate and improve the current LEED version, it is crucial to investigate and compare the impact of different LEED versions on the building energy performance and scoring scheme. However, researches comparing the sustainability metrics for mid-rise multi-family buildings are rare. Therefore, this paper investigates the potential changes in the energy performance resulted from applying different LEED versions (i.e., LEED v3 and v4) for the Energy and Atmosphere (EA) category. Towards this end, a case study was carried out with energy modeling and simulation using TRACE 700 to compare the changes in the energy performance of four analysis scenarios applied to an existing mid-rise multi-family building located in Ohio. Results showed notable changes in LEED points when different versions of LEED using different ASHRAE Standards (i.e., ASHRAE Standards 90.1-2007 and 90.1-2010) are applied for the building energy analysis. In particular, mid-rise multi-family buildings could benefit from LEED v4 in terms of LEED credits as the prerequisite for the minimum energy performance improvement in EA category became significantly lenient compared to LEED v3. On the

  15. Federal Participation in LEED in 2005

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Christopher; Dyer, Beverly

    2005-11-01

    The federal government is an active participant in promotingsustainable design, construction and operations and in the use of USGBC'sLeadership in Energy and Environmental Design (LEED) Green BuildingRating System. This paper presents an overview of sustainableconstruction activities in the federal sector in 2005.

  16. Surface processing: existing and potential applications of ultraviolet light.

    Science.gov (United States)

    Manzocco, Lara; Nicoli, Maria Cristina

    2015-01-01

    Solid foods represent optimal matrices for ultraviolet processing with effects well beyond nonthermal surface disinfection. UV radiation favors hormetic response in plant tissues and degradation of toxic compound on the product surface. Photoinduced reactions can also provide unexplored possibilities to steer structure and functionality of food biopolymers. The possibility to extensively exploit this technology will depend on availability of robust information about efficacious processing conditions and adequate strategies to completely and homogeneously process food surface.

  17. Regional Variations of Credits Obtained by LEED 2009 Certified Green Buildings—A Country Level Analysis

    Directory of Open Access Journals (Sweden)

    Peng Wu

    2017-12-01

    Full Text Available Leadership in Energy and Environmental Design (LEED is one of the most widely recognized green building rating systems. With more than 20% of the projects certified in non-United States (US countries, LEED’s global impact has been increasing and it is critically important for developers and regulatory authorities to understand LEED’s performance at the country level to facilitate global implementation. This study therefore aims to investigate the credit achievement pattern of LEED 2009, which is one of the well-developed versions of LEED, by using 4021 certified projects in the US, China, Turkey, and Brazil. The results show that significant differences can be identified on most rating categories, including sustainable sites, water efficiency, energy and atmosphere, indoor environmental quality, and innovation in design. Using a post hoc analysis, country-specific credit allocation patterns are also identified to help developers to understand existing country-specific green building practices. In addition, it is also found that there is unbalanced achievement of regional priority credits. The study offers a useful reference and benchmark for international developers and contractors to understand the regional variations of LEED 2009 and for regulatory authorities, such as the U.S. Green Building Council, to improve the rating system, especially on designing regional priority credits.

  18. Reliability of contemporary data-acquisition techniques for LEED analysis

    International Nuclear Information System (INIS)

    Noonan, J.R.; Davis, H.L.

    1980-10-01

    It is becoming clear that one of the principal limitations in LEED structure analysis is the quality of the experimental I-V profiles. This limitation is discussed, and data acquisition procedures described, which for simple systems, seem to enhance the quality of agreement between the results of theoretical model calculations and experimental LEED spectra. By employing such procedures to obtain data from Cu(100), excellent agreement between computed and measured profiles has been achieved. 7 figures

  19. Residents’ Support in Major Local Events: Leeds Pride.

    OpenAIRE

    Pappas, Nikolaos

    2016-01-01

    This article examines the extent to which community participation and perceived impacts have an influence on residents' support of major events, more specifically, the Leeds Pride celebration. The research examines the perspectives of 400 Leeds permanent residents. The study tests a structural equation model, which has its theoretical basis in social exchange theory. It examines the constructs of community participation, perceived positive and negative impacts, and community support, includin...

  20. Cost analysis of LEED certified United States navy buildings

    OpenAIRE

    Kirar, Carl V.

    2011-01-01

    CIVINS (Civilian Institutions) Thesis document A study was completed at UW-Madison in 2010 that reviewed the energy consumption of US Navy buildings which earned Leadership in Energy and Environmental Design (LEED) certification by the United States Green Building Council (USGBC). The research compared LEED certified buildings to a commercial counterpart within the US Navy inventory against Executive Order (EO) 13423. The EO mandated that all federal agencies meet a 30 percent reduction of...

  1. Designing healthy communities: A walkability analysis of LEED-ND

    Directory of Open Access Journals (Sweden)

    Adriana A. Zuniga-Teran

    2016-12-01

    Full Text Available Prevailing city design in many countries has created sedentary societies that depend on automobile use. Consequently, architects, urban designers, and land planners have developed new urban design theories, which have been incorporated into the Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND certification system. The LEED-ND includes design elements that improve human well-being by facilitating walking and biking, a concept known as walkability. Despite these positive developments, relevant research findings from other fields of study have not been fully integrated into the LEED-ND. According to Zuniga-Teran (2015, relevant walkability research findings from multiple disciplines were organized into a walkability framework (WF that organizes design elements related to physical activity into nine categories, namely, connectivity, land use, density, traffic safety, surveillance, parking, experience, greenspace, and community. In this study, we analyze walkability in the LEED-ND through the lens of the nine WF categories. Through quantitative and qualitative analyses, we identify gaps and strengths in the LEED-ND and propose potential enhancements to this certification system that reflects what is known about enhancing walkability more comprehensively through neighborhood design analysis. This work seeks to facilitate the translation of research into practice, which can ultimately lead to more active and healthier societies.

  2. 77 FR 26046 - Proposed Extension of Existing Information Collection; Ground Control for Surface Coal Mines and...

    Science.gov (United States)

    2012-05-02

    ... Extension of Existing Information Collection; Ground Control for Surface Coal Mines and Surface Work Areas of Underground Coal Mines AGENCY: Mine Safety and Health Administration, Labor. ACTION: Request for... inspections and investigations in coal or other mines shall be made each year for the purposes of, among other...

  3. Comparison of glass surfaces as a countertop material to existing surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Turo, Laura A.; Winschell, Abigail E.

    2011-09-01

    Gleen Glass, a small production glass company that creates countertops, was selected for the Technology Assistance Program through Pacific Northwest National Laboratory. Gleen Glass was seeking material property analysis comparing glass as a countertop material to current surfaces (i.e. marble, granite and engineered stone). With samples provided from Gleen Glass, testing was done on granite, marble, and 3 different glass surfaces ('Journey,' 'Pebble,' and 'Gleen'). Results showed the glass surfaces have a lower density, lower water absorption, and are stronger in compressive and flexural tests as compared to granite and marble. Thermal shock tests showed the glass failed when objects with a high thermal mass are placed directly on them, whereas marble and granite did not fracture under these conditions.

  4. Darning, doylies and dancing: the work of the Leeds Association of Girls' Clubs (1904-1913).

    Science.gov (United States)

    Jones, Helen M F

    2011-01-01

    The Leeds Association of Girls' Clubs (LAGC) was set up by a group of women, including Hilda Hargrove, Dr Lucy Buckley and Mary and Margaret Harvey, to promote collaboration between the city's girls' clubs. The organisation epitomised women working in partnership whilst reflecting their differing philanthropic and political interests. However LAGC's collaborative approach resulted in liberal consensus which downplayed the significance of girls' working conditions. Throughout the decade LAGC's focus was its annual competitions. These featured utilitarian and decorative handicrafts (darning and doylies) enshrining both frugality and aspiration, alongside dance and drill which channelled girls' vigour. Nevertheless, LAGC's resilience resulted in an organisation which is still in existence.

  5. Performance or marketing benefits? The case of LEED certification.

    Science.gov (United States)

    Matisoff, Daniel C; Noonan, Douglas S; Mazzolini, Anna M

    2014-01-01

    Green building adoption is driven by both performance-based benefits and marketing based benefits. Performance based benefits are those that improve performance or lower operating costs of the building or of building users. Marketing benefits stem from the consumer response to green certification. This study illustrates the relative importance of the marketing based benefits that accrue to Leadership in Energy and Environmental Design (LEED) buildings due to green signaling mechanisms, specifically related to the certification itself are identified. Of course, all participants in the LEED certification scheme seek marketing benefits. But even among LEED participants, the interest in green signaling is pronounced. The green signaling mechanism that occurs at the certification thresholds shifts building patterns from just below to just above the threshold level, and motivates builders to cluster buildings just above each threshold. Results are consistent across subsamples, though nonprofit organizations appear to build greener buildings and engage in more green signaling than for-profit entities. Using nonparametric regression discontinuity, signaling across different building types is observed. Marketing benefits due to LEED certification drives organizations to build "greener" buildings by upgrading buildings at the thresholds to reach certification levels.

  6. Characterization of Si(112) and In/Si(112) studied by SPA-LEED

    Energy Technology Data Exchange (ETDEWEB)

    Hoecker, Jan; Speckmann, Moritz; Schmidt, Thomas; Falta, Jens [Institute of Solid State Physics, University of Bremen, 28359 Bremen (Germany)

    2010-07-01

    High index surfaces are of strong interest in todays research because of the possibility to grow low dimensional structures. It has for instance already been shown that the adsorption of Ga can induce the formation of 1D metal chains on Si(112) (cf. Snijders et al., PRB 72, 2005). In this work we investigated the clean Si(112) surface and the adsorption of In on Si(112) to establish an analogy to Ga/Si(112) using spot profile analyzing low energy electron diffraction (SPA-LEED). By means of reciprocal space mapping we determined the bare Si(112) surface to be decomposed into alternating (5512) and (111) facets in [1 anti 10] direction with (2 x 1) and (7 x 7) reconstruction, respectively (cf. Baski et al., Surf. Sci. 392, 1997). With SPA-LEED we were able to observe the decreasing intensity of the facet spots in-situ while depositing In on Si(112) and thus reveal the smoothening of the surface due to the deposition of In. At saturation coverage we found a (3.x1) reconstruction, where x is dependent on the deposition temperature and changes from x=7 at 400 C to x=5 at 500 C. This leads us to the assumption that the reconstruction is not incommensurate but a mixture of (3 x 1) and (4 x 1) building blocks, which is very similar to the super structure of Ga on Si(112).

  7. Critical review of LEED system for rating sustainability of architecture of commercial interiors

    Directory of Open Access Journals (Sweden)

    Stevanović Sanja

    2010-01-01

    Full Text Available The LEED rating system for sustainability of architecture has gained large marketing potential in USA and became one of main ways American builders are attacking ecological challenges. In this paper the LEED rating system for commercial interiors is critically reviewed, pointing out its positive - focus on integrated design process - and negative impacts - low thresholds for highest ratings and tendency to gain LEED rating with projects that hardly pass the thresholds, largely neglecting the principles of energy efficiency. Based on a few prominent LEED platinum examples, the beginnings of a LEED style of designing interiors in historical landmark buildings are pointed out as well.

  8. PLEASE: The Python Low-energy Electron Analysis SuitE – Enabling Rapid Analysis of LEEM and LEED Data

    Directory of Open Access Journals (Sweden)

    Maxwell Grady

    2018-02-01

    Full Text Available PLEASE, the Python Low-energy Electron Analysis SuitE, provides an open source and cross-platform graphical user interface (GUI for rapid analysis and visualization of low energy electron microscopy (LEEM data sets. LEEM and the associated technique, selected area micro-spot low energy electron diffraction (μ-LEED, are powerful tools for analysis of the surface structure for many novel materials. Specifically, these tools are uniquely suited for the characterization of two-dimensional materials. PLEASE offers a user-friendly point-and-click method for extracting intensity-voltage curves from LEEM and LEED data sets. Analysis of these curves provides insight into the atomic structure of the target material surface with unparalleled resolution.

  9. Achieving LEED credit for ergonomics: Laying the foundation.

    Science.gov (United States)

    Lynch, Mallory

    2014-01-01

    Despite guidance from the United States Green Building Council (USGBC) on the requirements for earning a Leadership in Energy and Environmental Design (LEED) ergonomics credit in the Innovation in Design and Innovation in Operations category, few projects have received the credit. The University of California, Berkeley ergonomics program, Ergonomics@Work, has aligned the ergonomics strategy to those of the USGBC and LEED to achieve the ergonomics credit in several new buildings. This article describes the steps needed to obtain the credit and highlights the opportunities it creates to partner with the project team to promote ergonomics. As a profession it is up to ergonomists to create the road map that incorporates ergonomics into the green building design.

  10. Walkable new urban LEED_Neighborhood-Development (LEED-ND community design and children's physical activity: selection, environmental, or catalyst effects?

    Directory of Open Access Journals (Sweden)

    Stevens, Robert B

    2011-12-01

    Full Text Available Abstract Background Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends. Methods Fifth graders (n = 187 were sampled from two schools representing three communities: (1 a walkable community, Daybreak, designed with new urbanist and LEED-ND pilot design standards; (2 a mixed community (where students lived in a less walkable community but attended the walkable school so that part of the route to school was walkable, and (3 a less walkable community. Selection threats were addressed through controlling for parental preferences for their child to walk to school as well as comparing in-school MVPA for the walkable and mixed groups. Results Minutes of MVPA were tested with 3 × 2 (Community by Gender analyses of covariance (ANCOVAs. Community walkability related to more MVPA during the half hour before and after school and, among boys only, more MVPA after school. Boys were more active than girls, except during the half hour after school. Students from the mixed and walkable communities--who attended the same school--had similar in-school MVPA levels, and

  11. Walkable new urban LEED_Neighborhood-Development (LEED-ND) community design and children's physical activity: selection, environmental, or catalyst effects?

    Science.gov (United States)

    2011-01-01

    Background Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development) community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA) across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends. Methods Fifth graders (n = 187) were sampled from two schools representing three communities: (1) a walkable community, Daybreak, designed with new urbanist and LEED-ND pilot design standards; (2) a mixed community (where students lived in a less walkable community but attended the walkable school so that part of the route to school was walkable), and (3) a less walkable community. Selection threats were addressed through controlling for parental preferences for their child to walk to school as well as comparing in-school MVPA for the walkable and mixed groups. Results Minutes of MVPA were tested with 3 × 2 (Community by Gender) analyses of covariance (ANCOVAs). Community walkability related to more MVPA during the half hour before and after school and, among boys only, more MVPA after school. Boys were more active than girls, except during the half hour after school. Students from the mixed and walkable communities--who attended the same school--had similar in-school MVPA levels, and community groups

  12. Green roofs and the LEED green building rating system

    Energy Technology Data Exchange (ETDEWEB)

    Kula, R. [Sustainable Solutions Inc., Wagoner, OK (United States)

    2005-07-01

    The sustainable building industry is becoming increasingly aware of the host of public and private benefits that green roofs can provide in built environments. In dense urban environments, green roofs function to reduce stormwater runoff, urban heat island effects, and particulate matter (PM) pollution. The emerging green roof industry is now poised to support the efforts of green building networks in North America. This paper discussed the general benefits of green roofs, and their recognition within the Leadership in Energy and Environmental Design (LEED) Green Building Rating System. A case study of Mountain Equipment Co-op's Winnipeg site was presented. The building's green roof was directly responsible for earning 5 credits and contributing to the achievement of an additional 2 credits under the LEEDS certification process. Credits were earned for reduced site disturbance; landscape design to reduce heat islands; and water efficiency. The green roof at the site provided the vast majority of the building's cooling needs through an evaporative cooling trough. A photovoltaic pump was used to feed the building's irrigation system, as well as to pump ground water through cooling valances. It was concluded that the rise of sustainable building practices and the LEED Green Building Rating System will revolutionize the way new buildings are constructed.

  13. Electron attenuation anisotropy at crystal surfaces from LEED

    Czech Academy of Sciences Publication Activity Database

    Romanyuk, Olexandr; Bartoš, Igor

    2009-01-01

    Roč. 603, č. 17 (2009), s. 2789-2792 ISSN 0039-6028 R&D Projects: GA ČR GA202/07/0601; GA AV ČR IAA100100628 Institutional research plan: CEZ:AV0Z10100521 Keywords : electron attenuation length, low energy electron diffraction, photoelectron diffraction, electron–solid scattering and transmission, copper * low energy electron diffraction * photoelectron diffraction * electron–solid scattering and transmission * copper Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.798, year: 2009 http://dx.doi.org/10.1016/j.susc.2009.07.024

  14. Existence of a tribo-modified surface layer of BR/S-SBR elastomers reinforced with silica or carbon black

    NARCIS (Netherlands)

    Mokhtari, Milad; Schipper, Dirk J.

    2016-01-01

    The existence of a modified surface layer on top of a rubber disk, in contact with a rigid counter-surface, is still a point of discussion. In this study, we show that a modified surface layer with different mechanical properties exists. Modification of the reinforced elastomers is discussed and the

  15. Atomic-scale simulation of dust grain collisions: Surface chemistry and dissipation beyond existing theory

    Science.gov (United States)

    Quadery, Abrar H.; Doan, Baochi D.; Tucker, William C.; Dove, Adrienne R.; Schelling, Patrick K.

    2017-10-01

    The early stages of planet formation involve steps where submicron-sized dust particles collide to form aggregates. However, the mechanism through which millimeter-sized particles aggregate to kilometer-sized planetesimals is still not understood. Dust grain collision experiments carried out in the environment of the Earth lead to the prediction of a 'bouncing barrier' at millimeter-sizes. Theoretical models, e.g., Johnson-Kendall-Roberts and Derjaguin-Muller-Toporov theories, lack two key features, namely the chemistry of dust grain surfaces, and a mechanism for atomic-scale dissipation of energy. Moreover, interaction strengths in these models are parameterized based on experiments done in the Earth's environment. To address these issues, we performed atomic-scale simulations of collisions between nonhydroxylated and hydroxylated amorphous silica nanoparticles. We used the ReaxFF approach which enables modeling chemical reactions using an empirical potential. We found that nonhydroxylated nanograins tend to adhere with much higher probability than suggested by existing theories. By contrast, hydroxylated nanograins exhibit a strong tendency to bounce. Also, the interaction between dust grains has the characteristics of a strong chemical force instead of weak van der Waals forces. This suggests that the formation of strong chemical bonds and dissipation via internal atomic vibration may result in aggregation beyond what is expected based on our current understanding. Our results also indicate that experiments should more carefully consider surface conditions to mimic the space environment. We also report results of simulations with molten silica nanoparticles. It is found that molten particles are more likely to adhere due to viscous dissipation, which supports theories that suggest aggregation to kilometer scales might require grains to be in a molten state.

  16. Surface-geophysical techniques used to detect existing and infilled scour holes near bridge piers

    Science.gov (United States)

    Placzek, Gary; Haeni, F.P.

    1995-01-01

    Surface-geophysical techniques were used with a position-recording system to study riverbed scour near bridge piers. From May 1989 to May 1993. Fathometers, fixed- and swept-frequency con- tinuous seismic-reflection profiling (CSP) systems, and a ground-penetrating radar (GPR) system were used with a laser-positioning system to measure the depth and extent of existing and infilled scour holes near bridge piers. Equipment was purchased commercially and modified when necessary to interface the components and (or) to improve their performance. Three 200-kHz black-and-white chart- recording Fathometers produced profiles of the riverbed that included existing scour holes and exposed pier footings. The Fathometers were used in conjunction with other geophysical techniques to help interpret the geophysical data. A 20-kHz color Fathometer delineated scour-hole geometry and, in some cases, the thickness of fill material in the hole. The signal provided subbottom information as deep as 10 ft in fine-grained materials and resolved layers of fill material as thin as 1 foot thick. Fixed-frequency and swept-frequency CSP systems were evaluated. The fixed-frequency system used a 3.5-, 7.0-, or 14-kHz signal. The 3.5-kHz signal pene- trated up to 50 ft of fine-grained material and resolved layers as thin as 2.5-ft thick. The 14-kHz signal penetrated up to 20 ft of fine-grained material and resolved layers as thin as 1-ft thick. The swept-frequency systems used a signal that swept from 2- to 16-kHz. With this system, up to 50 ft of penetration was achieved, and fill material as thin as 1 ft was resolved. Scour-hole geometry, exposed pier footings, and fill thickness in scour holes were detected with both CSP systems. The GPR system used an 80-, 100-, or 300-megahertz signal. The technique produced records in water up to 15 ft deep that had a specific conductance less than 200x11ms/cm. The 100-MHz signal penetrated up to 40 ft of resistive granular material and resolved layers as

  17. Introducing comparative analysis to the LEED system: A case forrational and regional application

    Energy Technology Data Exchange (ETDEWEB)

    Eijadi, David; Vaidya, Prausad; Reinertsen, James; Kumar, Satish

    2002-06-01

    The LEED(TM) system awards points for prescriptive andperformance based environmental strategies; rightly giving more weight todecisions affecting building operations, since environmental impacts overthe life of a building exceed the one-time environmental impacts affectedby the building s construction. The environmental benefits of LEED(TM)strategies are considered implicit and the point system is not a metricof environmental performance. Thus, guideline strategies that achieve thesame points may not have analogous environmental performance. This paperdraws from our LEED(TM) project experience as certified consultants to anumber of design teams. We applied analysis to those experiences andargue that -The relative environmental value of the same LEED(TM)strategy may vary by geographical region and by building type. -Scoringsuccessive LEED(TM) points beyond a 'standard practice design'significantly increases design effort and capital costs for construction.-Without comparative analysis of the costs of alternate LEED(TM)strategies and their corresponding environmental benefit, designers willnot necessarily invest capital in strategies that most profoundlyminimize the environmental impacts of a building. -For design teams andowners interested in the least expensive LEED(TM) certification, gamingthe point system could drive investment away from sound environmentalperformance strategies such as energy efficiency. Using these arguments,this paper makes a case to enhance the LEED(TM) system by -CategorizingLEED(TM) strategies by their direct or indirect value towardsEnvironmental Benefit, Healthy Buildings (Places), and Profitability.-Reformulating prescriptive requirements into performance basedrequirements wherever possible. -Customizing LEED(TM) guidelines byregion.

  18. Radiofrequency electromagnetic fields in the Cookridge area of Leeds

    CERN Document Server

    Fuller, K; Judd, P M; Lowe, A J; Shaw, J

    2002-01-01

    On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on the towers. In addition, other major sources of radiofrequency electromagnetic fields in the environment such as broadcast radio...

  19. Influence of boundary conditions on the existence and stability of minimal surfaces of revolution made of soap films

    Science.gov (United States)

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2014-09-01

    Because of surface tension, soap films seek the shape that minimizes their surface energy and thus their surface area. This mathematical postulate allows one to predict the existence and stability of simple minimal surfaces. After briefly recalling classical results obtained in the case of symmetric catenoids that span two circular rings with the same radius, we discuss the role of boundary conditions on such shapes, working with two rings having different radii. We then investigate the conditions of existence and stability of other shapes that include two portions of catenoids connected by a planar soap film and half-symmetric catenoids for which we introduce a method of observation. We report a variety of experimental results including metastability—an hysteretic evolution of the shape taken by a soap film—explained using simple physical arguments. Working by analogy with the theory of phase transitions, we conclude by discussing universal behaviors of the studied minimal surfaces in the vicinity of their existence thresholds.

  20. Universidad de Leeds - Gran Bretaña

    Directory of Open Access Journals (Sweden)

    Chamberlin, -

    1977-11-01

    Full Text Available Located 1,500 m from the center of the city, the Leeds University complex actively participates in city life. Designed in the 60's and built later on, this architectonic complex is outstanding because it offers an «ideal» city, perfectly integrated in the «real» city and conditioned to its own needs, to a great extent. In the beginning, this challenge of converting this university complex with a capacity for 10,000 students, in an architectonically attractive urban center met with difficulties referring to traffic and parking problems corresponding to a city as large as the one projected; this obstacle was overcome by adequate organization of underground and overhead traffic arteries which reserved large garden areas exclusively for pedestrians, freeing them from the traffic congestion and offering the pleasant and relaxed atmosphere required. The large «campus» ¡s sub-divided into different garden areas, connected one to the other and In the center of each one we have a varied and complementary architecture, which breaks with the conventional monolithic style.Situado a 1.500 m del centro de la ciudad, el conjunto universitario de Leeds participa activamente de la misma. Concebido en la década de los 60, y construido posteriormente, este complejo arquitectónico se destaca por encerrar una propuesta de ciudad «ideal», perfectamente integrada en la ciudad «real» y sujeta en buena medida a sus mismas necesidades. La alternativa de convertir a este conjunto universitario, con capacidad para 10.000 estudiantes, en un núcleo urbano arquitectónicamente atractivo, tropezó inicialmente con los condicionamientos surgidos del tráfico, circulación y estacionamiento de vehículos, correspondientes a la magnitud de la ciudad proyectada; impedimento que fue resuelto de forma adecuada mediante la organización de una red subterránea y superficial de circulación vehicular, que reserva grandes espacios verdes para la circulaci

  1. The atomic structure of low-index surfaces of the intermetallic compound InPd

    Energy Technology Data Exchange (ETDEWEB)

    McGuirk, G. M.; Ledieu, J.; Gaudry, É.; Weerd, M.-C.; Fournée, V. de, E-mail: vincent.fournee@univ-lorraine.fr [Institut Jean Lamour (UMR 7198 CNRS-Université de Lorraine), Parc de Saurupt, F-54011 Nancy Cedex (France); Hahne, M.; Gille, P. [Department of Earth and Environmental Sciences, Crystallography Section, Ludwig-Maximilians-Universität München, Theresienstrasse 41, D-80333 München (Germany); Ivarsson, D. C. A.; Armbrüster, M. [Faculty of Natural Sciences, Institute of Chemistry, Materials for Innovative Energy Concepts, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Ardini, J.; Held, G. [Department of Chemistry, University of Reading, Reading RG6 6AD (United Kingdom); Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom); Maccherozzi, F. [Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom); Bayer, A. [Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen (Germany); Lowe, M. [Surface Science Research Centre and Department of Physics, The University of Liverpool, Liverpool L69 3BX (United Kingdom); Pussi, K. [Department of Mathematics and Physics, Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland); Diehl, R. D. [Department of Physics, Penn State University, University Park, Pennsylvania 16802 (United States)

    2015-08-21

    The intermetallic compound InPd (CsCl type of crystal structure with a broad compositional range) is considered as a candidate catalyst for the steam reforming of methanol. Single crystals of this phase have been grown to study the structure of its three low-index surfaces under ultra-high vacuum conditions, using low energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). During surface preparation, preferential sputtering leads to a depletion of In within the top few layers for all three surfaces. The near-surface regions remain slightly Pd-rich until annealing to ∼580 K. A transition occurs between 580 and 660 K where In segregates towards the surface and the near-surface regions become slightly In-rich above ∼660 K. This transition is accompanied by a sharpening of LEED patterns and formation of flat step-terrace morphology, as observed by STM. Several superstructures have been identified for the different surfaces associated with this process. Annealing to higher temperatures (≥750 K) leads to faceting via thermal etching as shown for the (110) surface, with a bulk In composition close to the In-rich limit of the existence domain of the cubic phase. The Pd-rich InPd(111) is found to be consistent with a Pd-terminated bulk truncation model as shown by dynamical LEED analysis while, after annealing at higher temperature, the In-rich InPd(111) is consistent with an In-terminated bulk truncation, in agreement with density functional theory (DFT) calculations of the relative surface energies. More complex surface structures are observed for the (100) surface. Additionally, individual grains of a polycrystalline sample are characterized by micro-spot XPS and LEED as well as low-energy electron microscopy. Results from both individual grains and “global” measurements are interpreted based on comparison to our single crystals findings, DFT calculations and previous literature.

  2. LEED conformity inside and outside. Headquarters of the Deutsche Boerse in LEED {sup registered} Platin; Aussen und innen LEED-konform. Zentrale der Deutschen Boerse in LEED {sup registered} Platin

    Energy Technology Data Exchange (ETDEWEB)

    Bloedorn, Heike

    2011-07-01

    Due to the sustainable design of building, the new corporate headquarters of the group German Stock Exchange in Frankfurt (Federal Republic of Germany) with an investment of nearly 230 million Euro has been distinguished as the first skyscraper in Germany with the LEED platinum certification (as the highest category of the U.S. Green Building Council). The design of the 21-story building was by the architects KSP Engel Juergen Architekten GmbH (Frankfurt, Federal Republic of Germany). The project was developed by Gross Partner and Grundstuecksentwicklungsgesellschaft mbH (Frankfurt, Federal Republic of Germany) and Lang and Cie. Real Estate (Frankfurt, Federal Republic of Germany). The innovative energy concept was realized by Lenz Weber Ingenieure (Frankfurt, Federal Republic of Germany) in cooperation with EB-Partner GmbH and Co. KG (Frankfurt/Nuernberg, Federal Republic) and TP Electrical Plan (Gaggenau, Federal Republic of Germany). The stringent sustainability criteria in the interior construction were accomplished by feco wood materials in the form of displaceable system partition walls and sound absorbing doors.

  3. On the Possibility of the Existence of a Surface Electromagnetic Wave in the Permafrost Area

    Science.gov (United States)

    Balkhanov, V. K.; Bashkuev, Yu. B.; Advokatov, V. R.

    2018-01-01

    The results of measurements of the vertical component of electric field at a radio path with the permafrost at a frequency of 255 kHz have been interpreted. An analysis of the results has shown that the considered radio path exhibits the properties of a two-part impedance surface, i.e., it consists of two sections. At a distance of 70 km from a radiation source and at a frequency of 255 kHz of the electromagnetic wave, the field decreases with the distance R according to the power law as R -1.5 and a power index takes an intermediate value between the power indices for decreasing the field in free space R -2 and for the decrease in the field above an ideal conducting surface R -1. With further propagation at a distance of 70-220 km, the field shows the specific behavior of a surface electromagnetic wave.

  4. Existence of Insecticides in Tap Drinking Surface and Ground Water in Dakahlyia Governorate, Egypt in 2011

    Directory of Open Access Journals (Sweden)

    RA Mandour

    2011-12-01

    Full Text Available Background: The environmental degradation products of pesticides may enter drinking water and result in serious health problems. Objective: To evaluate the occurrence of insecticides in drinking surface and ground water in Dakahlyia Governorate, northern Egypt in 2011. Methods: We studied blood samples collected from 36 consecutive patients diagnosed with pesticides poisoning and 36 tap drinking water (surface and ground. Blood and water samples were analyzed for pesticides using gas chromatography-electron captured detector (GC-ECD. In addition, blood samples were analyzed for plasma pseudo-cholinesterase level (PChE and red blood cells acetyl cholinesterase activity (AChE. Results: The results confirmed the presence of high concentrations of insecticides, including organonitrogenous and organochlorine in tap drinking surface and ground water. Conclusion: Drinking water contaminated with insecticides constitutes an important health concern in Dakahlyia governorate, Egypt.

  5. Existence of torsional surface waves in an earth's crustal layer lying ...

    Indian Academy of Sciences (India)

    This paper aims to study the dispersion of torsional surface waves in a crustal layer being sandwiched between a rigid boundary plane and a sandy mantle. In the mantle, rigidity and initial stress vary linearly while density remains constant. Dispersion relation has been deduced in a closed form by means of variable ...

  6. On the Existence of the Logarithmic Surface Layer in the Inner Core of Hurricanes

    Science.gov (United States)

    2012-01-01

    characteristics of eyewall boundary layer of Hurricane Hugo (1989). Mon. Wea. Rev., 139, 1447-1462. Zhang, JA, Montgomery MT. 2012 Observational...the inner core of hurricanes Roger K. Smitha ∗and Michael T. Montgomeryb a Meteorological Institute, University of Munich, Munich, Germany b Dept. of...logarithmic surface layer”, or log layer, in the boundary layer of the rapidly-rotating core of a hurricane . One such study argues that boundary-layer

  7. Biological variables for the site survey of surface ecosystems - existing data and survey methods

    International Nuclear Information System (INIS)

    Kylaekorpi, Lasse; Berggren, Jens; Larsson, Mats; Liberg, Maria; Rydgren, Bernt

    2000-06-01

    In the process of selecting a safe and environmentally acceptable location for the deep level repository of nuclear waste, site surveys will be carried out. These site surveys will also include studies of the biota at the site, in order to assure that the chosen site will not conflict with important ecological interests, and to establish a thorough baseline for future impact assessments and monitoring programmes. As a preparation to the site survey programme, a review of the variables that need to be surveyed is conducted. This report contains the review for some of those variables. For each variable, existing data sources and their characteristics are listed. For those variables for which existing data sources are inadequate, suggestions are made for appropriate methods that will enable the establishment of an acceptable baseline. In this report the following variables are reviewed: Fishery, Landscape, Vegetation types, Key biotopes, Species (flora and fauna), Red-listed species (flora and fauna), Biomass (flora and fauna), Water level, water retention time (incl. water body and flow), Nutrients/toxins, Oxygen concentration, Layering, stratification, Light conditions/transparency, Temperature, Sediment transport, (Marine environments are excluded from this review). For a major part of the variables, the existing data coverage is most likely insufficient. Both the temporal and/or the geographical resolution is often limited, which means that complementary surveys must be performed during (or before) the site surveys. It is, however, in general difficult to make exact judgements on the extent of existing data, and also to give suggestions for relevant methods to use in the site surveys. This can be finally decided only when the locations for the sites are decided upon. The relevance of the different variables also depends on the environmental characteristics of the sites. Therefore, we suggest that when the survey sites are selected, an additional review is

  8. Biological variables for the site survey of surface ecosystems - existing data and survey methods

    Energy Technology Data Exchange (ETDEWEB)

    Kylaekorpi, Lasse; Berggren, Jens; Larsson, Mats; Liberg, Maria; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)

    2000-06-01

    In the process of selecting a safe and environmentally acceptable location for the deep level repository of nuclear waste, site surveys will be carried out. These site surveys will also include studies of the biota at the site, in order to assure that the chosen site will not conflict with important ecological interests, and to establish a thorough baseline for future impact assessments and monitoring programmes. As a preparation to the site survey programme, a review of the variables that need to be surveyed is conducted. This report contains the review for some of those variables. For each variable, existing data sources and their characteristics are listed. For those variables for which existing data sources are inadequate, suggestions are made for appropriate methods that will enable the establishment of an acceptable baseline. In this report the following variables are reviewed: Fishery, Landscape, Vegetation types, Key biotopes, Species (flora and fauna), Red-listed species (flora and fauna), Biomass (flora and fauna), Water level, water retention time (incl. water body and flow), Nutrients/toxins, Oxygen concentration, Layering, stratification, Light conditions/transparency, Temperature, Sediment transport, (Marine environments are excluded from this review). For a major part of the variables, the existing data coverage is most likely insufficient. Both the temporal and/or the geographical resolution is often limited, which means that complementary surveys must be performed during (or before) the site surveys. It is, however, in general difficult to make exact judgements on the extent of existing data, and also to give suggestions for relevant methods to use in the site surveys. This can be finally decided only when the locations for the sites are decided upon. The relevance of the different variables also depends on the environmental characteristics of the sites. Therefore, we suggest that when the survey sites are selected, an additional review is

  9. Radiofrequency electromagnetic fields in the Cookridge area of Leeds

    International Nuclear Information System (INIS)

    Fuller, K.; Gulson, A.D.; Judd, P.M.; Lowe, A.J.; Shaw, J.

    2002-01-01

    On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on the towers. In addition, other major sources of radiofrequency electromagnetic fields in the environment such as broadcast radio and television transmissions are included in this range. Measurements of power density were made at eight locations in the vicinity of the transmitter sites. Comparison of the measurements with the guidelines showed that the total exposure from radio signals measured between 30 MHz and 18 GHz ranged from 0.26 millionths (0.000026%) to 190 millionths (0.019%) of the NRPB investigation level and from 1.6 millionths (0.00016%) to 1400 millionths (0.14%) of the ICNIRP reference level for exposure of the general public. All the measured exposures are therefore many times below guideline levels and are not considered hazardous. (author)

  10. Analysis of secondary electron emission for conducting materials using 4-grid LEED/AES optics

    International Nuclear Information System (INIS)

    Patino, M I; Wirz, R E; Raitses, Y; Koel, B E

    2015-01-01

    A facility utilizing 4-grid optics for LEED/AES (low energy electron diffraction/Auger electron spectroscopy) was developed to measure the total secondary electron yield and secondary electron energy distribution function for conducting materials. The facility and experimental procedure were validated with measurements of 50–500 eV primary electrons impacting graphite. The total yield was calculated from measurements of the secondary electron current (i) from the sample and (ii) from the collection assembly, by biasing each surface. Secondary electron yield results from both methods agreed well with each other and were within the spread of previous results for the total yield from graphite. Additionally, measurements of the energy distribution function of secondary electrons from graphite are provided for a wider range of incident electron energies. These results can be used in modeling plasma-wall interactions in plasmas bounded by graphite walls, such as are found in plasma thrusters, and divertors and limiters of magnetic fusion devices. (paper)

  11. Carbon Footprint of Housing in the Leeds City Region - A Best Practice Scenario Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, John; Dawkins, Elena (Stockholm Environment Inst. (Sweden))|(Univ. of York, Heslington, York YO10 5DD (United Kingdom))

    2008-06-15

    The Stockholm Environment Institute (SEI) was commissioned by the Environment Agency to carry out a carbon footprint analysis of the housing sector, using the Leeds City Region (LCR) as an example. The aim was to determine our ability to meet the 80 per cent by 2050 challenge of energy efficiency in the housing sector. The study relates specifically to LCR but its findings will help any planning and development teams make the right decisions and gain the resources necessary to meet carbon budgets at regional and local levels. With a growing population and an additional 263,000 housing units to be built within LCR by 2026, the housing sector would need to reduce its expected total carbon dioxide emissions by 38 million tonnes between 2010 and 2026 to be on track for 80 per cent savings in 2050. The report outlines the most detailed analysis to date of the required measures to deliver a growth-based regional housing strategy, alongside reducing carbon emissions. If the city region's new and existing housing is to attain the levels of energy efficiency necessary to deliver these carbon savings, big changes will be required in the way we build, maintain and run our homes over the next 20 years. There are pockets of good practice already in the region and the study shows that by combining innovative measures on construction standards, improvements to existing housing, low and zero carbon technologies and changing behaviour of householders, LCR can achieve the necessary savings to meet its carbon budget

  12. Integrating Building Information Modeling and Green Building Certification: The BIM-LEED Application Model Development

    Science.gov (United States)

    Wu, Wei

    2010-01-01

    Building information modeling (BIM) and green building are currently two major trends in the architecture, engineering and construction (AEC) industry. This research recognizes the market demand for better solutions to achieve green building certification such as LEED in the United States. It proposes a new strategy based on the integration of BIM…

  13. Evaluation of the Work-Place Cooperative Project in Geography Degrees at the University of Leeds.

    Science.gov (United States)

    Hogg, James

    1998-01-01

    Describes the context and objective of a Work-Place Cooperative Project (WPCP) established in the School of Geography at the University of Leeds in 1995. The project presents students with business, commerce, industry, and environmental research issues that have geographical dimensions. Includes a number of examples from the WPCP. (MJP)

  14. Effects of blending of desalinated and conventionally treated surface water on iron corrosion and its release from corroding surfaces and pre-existing scales.

    Science.gov (United States)

    Liu, Haizhou; Schonberger, Kenneth D; Peng, Ching-Yu; Ferguson, John F; Desormeaux, Erik; Meyerhofer, Paul; Luckenbach, Heidi; Korshin, Gregory V

    2013-07-01

    This study examined effects of blending desalinated water with conventionally treated surface water on iron corrosion and release from corroding metal surfaces and pre-existing scales exposed to waters having varying fractions of desalinated water, alkalinities, pH values and orthophosphate levels. The presence of desalinated water resulted in markedly decreased 0.45 μm-filtered soluble iron concentrations. However, higher fractions of desalinated water in the blends were also associated with more fragile corroding surfaces, lower retention of iron oxidation products and release of larger iron particles in the bulk water. SEM, XRD and XANES data showed that in surface water, a dense layer of amorphous ferrihydrite phase predominated in the corrosion products. More crystalline surface phases developed in the presence of desalinated water. These solid phases transformed from goethite to lepidocrocite with increased fraction of desalinated water. These effects are likely to result from a combination of chemical parameters, notably variations of the concentrations of natural organic matter, calcium, chloride and sulfate when desalinated and conventionally treated waters are blended. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces

    Science.gov (United States)

    Echarri, Víctor; Espinosa, Almudena; Rizo, Carlos

    2017-01-01

    Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100), air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions. PMID:29292781

  16. Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces.

    Science.gov (United States)

    Echarri, Víctor; Espinosa, Almudena; Rizo, Carlos

    2017-12-08

    Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100), air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions.

  17. Thermal Transmission through Existing Building Enclosures: Destructive Monitoring in Intermediate Layers versus Non-Destructive Monitoring with Sensors on Surfaces

    Directory of Open Access Journals (Sweden)

    Víctor Echarri

    2017-12-01

    Full Text Available Opaque enclosures of buildings play an essential role in the level of comfort experienced indoors and annual energy demand. The impact of solar radiation and thermal inertia of the materials that make up the multi-layer enclosures substantially modify thermal transmittance behaviour of the enclosures. This dynamic form of heat transfer, additionally affected by indoor HVAC systems, has a substantial effect on the parameters that define comfort. It also has an impact on energy demand within a daily cycle as well as throughout a one-year use cycle. This study describes the destructive monitoring of an existing block of flats located in Alicante. Once the enclosure was opened, sensors of temperature (PT100, air velocity, and relative humidity were located in the different layers of the enclosure, as well as in the interior and exterior surfaces. A pyranometer was also installed to measure solar radiation levels. A temperature data correction algorithm was drawn up to address irregularities produced in the enclosure. The algorithm was applied using a Raspberry Pi processor in the data collection system. The comparative results of temperature gradients versus non-destructive monitoring systems are presented, providing measures of the transmittance value, surface temperatures and indoor and outdoor air temperatures. This remote sensing system can be used in future studies to quantify and compare the energy savings of different enclosure construction solutions.

  18. Surface physics : experimental

    International Nuclear Information System (INIS)

    Padalia, B.D.

    1978-01-01

    In this report, discussion is confined to some important ultra high vacuum surface techniques such as ultra-violet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and the low energy electron diffraction (LEED). An attempt is made to cover the basic principles and the experimental details of XPS and AES. Selected examples illustrating the potentialities of the above techniques to solve the important basic as well as applied problems relating to surfaces are presented. Salient features of the available commercial machines in which UPS, AES and LEED are combined to facilitate surface examination sequentially or simultaneously under identical experimental conditions are indicated. (auth.)

  19. Assessment of Energy Credits in LEED-Certified Buildings Based on Certification Levels and Project Ownership

    Directory of Open Access Journals (Sweden)

    Asli Pelin Gurgun

    2018-02-01

    Full Text Available Compared to other categories, the Energy and Atmosphere category contributes the most to the maximum obtainable points in the Leadership in Energy and Environmental Design (LEED certification system. The objective of the study was to identify the extent to which project teams take advantage of the credits in the Energy and Atmosphere category of LEED. This study analyzes the performance of practitioners in achieving points in the Energy and Atmosphere credits of LEED-New Construction (NC 2009 for 1500 buildings that received LEED certification in the US. For a better understanding of the credit patterns, the differences in the performance of practitioners are investigated relative to certification levels and project ownership. Achievement in credits is calculated in terms of percent of maximum points (PMP, since the maximum achievable points differ for each credit. Practitioners’ achievements in the credits were ranked as follows: (1 enhanced commissioning, (2 optimized energy performance, (3 enhanced refrigerant management, (4 green power, (5 measurement and verification, and (6 on-site renewable energy. The largest achievement differences were observed in the on-site renewable energy credit. Concerning building ownership, investors were found to optimize mostly energy efficiency and on-site renewable energy, but to mostly skip enhanced refrigerant management. Performance in the measurement and verification credit was similar for all owner types, whereas investors performed differently from corporations, and government agencies in the enhanced commissioning credit. Practitioners who recognize these priorities and differences are expected to be better positioned to make sustainability-related decisions in building design and construction.

  20. Indoor environmental quality differences between office types in LEED-certified buildings in the US

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young S. [School of Planning, Design, and Construction, Michigan State University, East Lansing, MI 48823 (United States); Guerin, Denise A. [College of Design, University of Minnesota, Twin Cities, MN 55108 (United States)

    2010-05-15

    The study compared IAQ, thermal quality, and lighting quality between 5 different office types in LEED-certified buildings in relation to employees' environmental satisfaction and their job performance. This was to provide workplaces where workers in each specific office environment could be provided with appropriate office settings regarding these IEQ criteria when organizations comply with LEED standards. The five types of office included private enclosed, private shared, open-plan with high cubicle over 5', open-plan with low cubicle lower than 5', and open-plan with no partitions (bullpen) offices. The study found IAQ enhanced workers' job performance in enclosed private offices more than both high cubicles and low cubicles. All four office types had higher satisfaction with the amount of light and visual comfort of light as well as more enhancement with job performance due to lighting quality than high cubicles. There was no difference in thermal quality between the five office types. IAQ and lighting quality were not different between enclosed private, enclosed shared, and bullpen office types, either. The study findings suggest a careful workplace design considering the height of partitions in LEED-certified buildings to improve employee's environmental satisfaction and job performance. (author)

  1. The association between the geography of fast food outlets and childhood obesity rates in Leeds, UK.

    Science.gov (United States)

    Fraser, Lorna K; Edwards, Kimberley L

    2010-11-01

    To analyse the association between childhood overweight and obesity and the density and proximity of fast food outlets in relation to the child's residential postcode. This was an observational study using individual level height/weight data and geographic information systems methodology. Leeds in West Yorkshire, UK. This area consists of 476 lower super-output areas. Children aged 3-14 years who lived within the Leeds metropolitan boundaries (n=33,594). The number of fast food outlets per area and the distance to the nearest fast food outlet from the child's home address. The weight status of the child: overweight, obese or neither. 27.1% of the children were overweight or obese with 12.6% classified as obese. There is a significant positive correlation (pfood outlets and higher deprivation. A higher density of fast food outlets was significantly associated (p=0.02) with the child being obese (or overweight/obese) in the generalised estimating equation model which also included sex, age and deprivation. No significant association between distance to the nearest fast food outlet and overweight or obese status was found. There is a positive relationship between the density of fast food outlets per area and the obesity status of children in Leeds. There is also a significant association between fast food outlet density and areas of higher deprivation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS project: An open-label pragmatic randomised control trial comparing the efficacy of differing therapeutic agents for primary care detoxification from either street heroin or methadone [ISRCTN07752728

    Directory of Open Access Journals (Sweden)

    Sheard Laura

    2004-04-01

    Full Text Available Abstract Background Heroin is a synthetic opioid with an extensive illicit market leading to large numbers of people becoming addicted. Heroin users often present to community treatment services requesting detoxification and in the UK various agents are used to control symptoms of withdrawal. Dissatisfaction with methadone detoxification 8 has lead to the use of clonidine, lofexidine, buprenorphine and dihydrocodeine; however, there remains limited evaluative research. In Leeds, a city of 700,000 people in the North of England, dihydrocodeine is the detoxification agent of choice. Sublingual buprenorphine, however, is being introduced. The comparative value of these two drugs for helping people successfully and comfortably withdraw from heroin has never been compared in a randomised trial. Additionally, there is a paucity of research evaluating interventions among drug users in the primary care setting. This study seeks to address this by randomising drug users presenting in primary care to receive either dihydrocodeine or buprenorphine. Methods/design The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS project is a pragmatic randomised trial which will compare the open use of buprenorphine with dihydrocodeine for illicit opiate detoxification, in the UK primary care setting. The LEEDS project will involve consenting adults and will be run in specialist general practice surgeries throughout Leeds. The primary outcome will be the results of a urine opiate screening at the end of the detoxification regimen. Adverse effects and limited data to three and six months will be acquired.

  3. Mining Association Rules Between Credits in the Leadership in Energy and Environmental Design for New Construction (LEED-NC) Green Building Assessment System

    National Research Council Canada - National Science Library

    Thomas, Benjamin J

    2008-01-01

    .... Taking this vision into account, the individual credits that comprise LEED are designed to reward design teams for employing sustainable design strategies that reduce the total environmental impact...

  4. The early stages of oxidation of magnesium single crystal surfaces

    International Nuclear Information System (INIS)

    Hayden, B.E.; Schweizer, E.; Koetz, R.; Bradshaw, A.M.

    1981-01-01

    The early stages of oxidation of Mg(001) and Mg(100) single crystal surfaces at 300 K have been investigated by LEED, ELS, work function and ellipsometric measurements. A sharp decrease in work function on both surfaces during the first 12 L exposure indicates the incorporation of oxygen in the earliest stages of the interaction. The incorporated oxygen on Mg(001) gives rise to a broadening of the integral order LEED spots for an exposure 3 L. (orig.)

  5. A Variational Reduction and the Existence of a Fully Localised Solitary Wave for the Three-Dimensional Water-Wave Problem with Weak Surface Tension

    Science.gov (United States)

    Buffoni, Boris; Groves, Mark D.; Wahlén, Erik

    2018-06-01

    Fully localised solitary waves are travelling-wave solutions of the three- dimensional gravity-capillary water wave problem which decay to zero in every horizontal spatial direction. Their existence has been predicted on the basis of numerical simulations and model equations (in which context they are usually referred to as `lumps'), and a mathematically rigorous existence theory for strong surface tension (Bond number {β} greater than {1/3}) has recently been given. In this article we present an existence theory for the physically more realistic case {0 point of the reduced functional is found by minimising it over its natural constraint set.

  6. A study of the effects of computer animation on college students’ learning of Leadership in Energy and Environmental Design - LEED

    Directory of Open Access Journals (Sweden)

    Razieh Nilforooshan

    2013-10-01

    Full Text Available This paper presents ongoing research aimed at investigating the efficacy of computer animations in improving college students’ learning of building sustainability concepts and practices. The use of animations in educational contexts is not new, however scientific evidence that supports their effectiveness as educational materials is still limited. This paper reports an experiment that explored the impact of an educational digital animation, called “LEED-ERS”, on college students’ learning of Leadership in Energy and Environmental Design (LEED rating system. Specifically, the animation focused on the LEED category of Sustainable Site. Results of a study with 68 students show that viewing the animation led to an increase in subjects’ declarative knowledge by 15%. Compared to traditional learning methods (e.g. reading assignments with static images, viewing the animation led to significantly higher declarative knowledge gains.

  7. The two-glass-building in Ratingen. LEED platin for the Coca-Cola headquarter; Das Zwei-Scheiben-Haus in Ratingen. LEED-Platin fuer die Coca-Cola-Zentrale

    Energy Technology Data Exchange (ETDEWEB)

    Zerres, Eberhard

    2011-07-01

    In order to receive the eco-labeled LEED platinum category, a good planning is essential. In the construction of a new administration building in Ratingen (Federal Republic of Germany), many details have been considered up to the use of ecologically unquestionable building materials. Thus, these details were very purposeful.

  8. Low-energy electron diffraction experiment, theory and surface structure determination

    CERN Document Server

    Hove, Michel A; Chan, Chi-Ming

    1986-01-01

    Surface crystallography plays the same fundamental role in surface science which bulk crystallography has played so successfully in solid-state physics and chemistry. The atomic-scale structure is one of the most important aspects in the understanding of the behavior of surfaces in such widely diverse fields as heterogeneous catalysis, microelectronics, adhesion, lubrication, cor­ rosion, coatings, and solid-solid and solid-liquid interfaces. Low-Energy Electron Diffraction or LEED has become the prime tech­ nique used to determine atomic locations at surfaces. On one hand, LEED has yielded the most numerous and complete structural results to date (almost 200 structures), while on the other, LEED has been regarded as the "technique to beat" by a variety of other surface crystallographic methods, such as photoemission, SEXAFS, ion scattering and atomic diffraction. Although these other approaches have had impressive successes, LEED has remained the most productive technique and has shown the most versatility...

  9. Sokol Blosser Barrel Aging Cellar : green roofs and LEED{sup TM} buildings in the rural context

    Energy Technology Data Exchange (ETDEWEB)

    Cravens, L.L. [Sera Architects Inc., Portland, OR (United States)

    2004-07-01

    An earth covered structure that stores 900 barrels of wine at the Sokol Blosser Winery located in Yamhill Valley, southeast of Portland, Oregon was presented. The owner's decision to build as sustainably as possible when constructing the barrel aging cellar was reinforced by their involvement in the Oregon Natural Step Network, a non-profit organization that promotes sustainability principles in any endeavor. The sustainable project design solution led by SERA Architects met the winery's requirements for an underground structure capable of storing 900 barrels of wine in three chambers; natural daylight throughout; control over the temperature and humidity; natural ventilation; the use of sustainable materials, and minimal materials; use of local products; preserving the maximum existing open area; and, minimizing construction demolition and waste. The Leadership in Energy and Environmental Design (LEED) criteria for the green building rating system was used to measure the green construction practices. The many benefits of burying the building were identified, namely the cooling system was eliminated, which reduced the cost of the mechanical system, reduced the major draw for energy, and eliminated any use of ozone depleting refrigerants. The roof's waterproofing system was provided by Tremco. Combined with a non-engineered earth cover the manufacturer provided a warranty of 20 years but predicted a 60 year life for the roof. The Roof sandwich structure from top down was described in detail and illustrations were presented. The final calculations indicate a $750 annual energy savings above a traditional space. 6 figs.

  10. Low energy electron diffraction (LEED) and sum frequency generation (SFG) vibrational spectroscopy studies of solid-vacuum, solid-air and solid-liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hoffer, Saskia [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    Electron based surface probing techniques can provide detailed information about surface structure or chemical composition in vacuum environments. The development of new surface techniques has made possible in situ molecular level studies of solid-gas interfaces and more recently, solid-liquid interfaces. The aim of this dissertation is two-fold. First, by using novel sample preparation, Low Energy Electron Diffraction (LEED) and other traditional ultra high vacuum (UHV) techniques are shown to provide new information on the insulator/vacuum interface. The surface structure of the classic insulator NaCl has been determined using these methods. Second, using sum frequency generation (SFG) surface specific vibrational spectroscopy studies were performed on both the biopolymer/air and electrode/electrolyte interfaces. The surface structure and composition of polyetherurethane-silicone copolymers were determined in air using SFG, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). SFG studies of the electrode (platinum, gold and copper)/electrolyte interface were performed as a function of applied potential in an electrochemical cell.

  11. THE MECHANISM OF SURFACE DIFFUSION OF H AND D ATOMS ON AMORPHOUS SOLID WATER: EXISTENCE OF VARIOUS POTENTIAL SITES

    Energy Technology Data Exchange (ETDEWEB)

    Hama, Tetsuya; Kuwahata, Kazuaki; Watanabe, Naoki; Kouchi, Akira; Chigai, Takeshi [Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido 060-0819 (Japan); Kimura, Yuki [Department of Earth and Planetary Materials Science, Tohoku University, Sendai 980-8578 (Japan); Pirronello, Valerio, E-mail: hama@lowtem.hokudai.ac.jp [Dipartimento di Fisica e Astronomia, Universita' di Catania, I-95125 Catania, Sicily (Italy)

    2012-10-01

    To understand elementary processes leading to H{sub 2} formation, and the hydrogenation and deuteration reactions of adsorbed species on dust grains in dense clouds, we experimentally investigated the diffusion of atomic hydrogen and deuterium on amorphous solid water (ASW) at temperatures of 8-15 K. The present study extended our previous study for selective detections of H and D atoms, and of H{sub 2} (J = 0 and 1) and D{sub 2} (J = 0 and 1) molecules adsorbed on ASW using both photo-stimulated desorption and resonance-enhanced multiphoton ionization, to investigate potential sites on ASW for diffusion, recombination dynamics, and the diffusion mechanism of H and D atoms. Our results demonstrate that the ASW surface contains various potential sites that can be categorized into at least three groups: very shallow, middle-, and deep-potential sites, with diffusion activation energies of {<=}18, 22 (23 meV for D atoms), and {>=}30 meV, respectively. The present study pictured the outline of H{sub 2} formation on cosmic ice dust at low temperatures: H atoms landing on the dust will diffuse rapidly at the abundant shallow and middle sites on ASW, and finally become trapped at deep sites. The H atoms that arrive next recombine with such trapped H atoms to yield H{sub 2} molecules. The small isotopic difference between the diffusion of H and D atoms on ASW indicates that the diffusion mechanism can be explained by thermal hopping, at least at middle-potential sites.

  12. Uno strumento per la creazione di valore nella realizzazione di edifici sostenibili: la certificazione LEED

    Directory of Open Access Journals (Sweden)

    S. Rick Fedrizzi

    2014-06-01

    Full Text Available Il presente lavoro ha l’obiettivo di delineare gli aspetti chiave della sostenibilità in ambito edilizio focalizzando l’attenzione sul sistema di certificazione LEED® quale strumento “universale” di supporto per la realizzazione, gestione e valutazione di edifici sostenibili. Nella prima parte del lavoro si descrive la rapida diffusione della certificazione LEED nel recente passato quale diretta conseguenza della capacità di questo strumento di rating di adattarsi sia alle specifiche tipologie di edifici, sia alle diversità climatiche e morfologiche dei siti. Nella seconda parte si procede invece a presentare ed analizzare gli aspetti economico-finanziari degli edifici sostenibili con riferimento sia alle metodologie valutative applicabili, sia ai dati della letteratura. Partendo dalle esperienze internazionali in tema di sostenibilità, si procede successivamente a descrivere la situazione italiana, evidenziando la percezione del mercato e le opportunità di sviluppo future.

  13. Impacts of pre-existing ocean cyclonic circulation on sea surface chlorophyll-a concentrations off northeastern Taiwan following episodic typhoon passages

    Science.gov (United States)

    Xu, Fanghua; Yao, Yuan; Oey, Leo; Lin, Yanluan

    2017-08-01

    Off northeastern Taiwan, enhancement of sea surface chlorophyll-a (Chl-a) concentration is frequently found after typhoon passages. From 1998 to 2013, 46 typhoon events are analyzed to examine the variations in Chl-a concentration from satellite ocean color data. On average, Chl-a concentration increased by 38% after a typhoon passage. Noticeably, four remarkable Chl-a increases after typhoons coincide with pre-existing oceanic cyclones in the study area. The Chl-a increase is significantly anticorrelated (p typhoons, we conduct a series of numerical experiments to simulate the oceanic response to Typhoon Kaemi (2006) with or without a pre-existing oceanic cyclone, and with or without strong typhoon winds. The results show that the experiment with a pre-existing oceanic cyclone produces the largest upwelling due to cyclone intensification, mainly induced by the positive wind stress curl dipole northeast of Taiwan.

  14. “THE LEEDS IDEA”: AN HISTORICAL ACCOUNT OF THE SPONDARTHRITIS CONCEPT

    Directory of Open Access Journals (Sweden)

    J.M.H. Moll

    2011-09-01

    Full Text Available SUMMARY In the 1960s, Professor Verna Wright became increasingly interested in possible relationships between certain seronegative “variants of rheumatoid arthritis”, as they were then generally known. At the Rheumatism Research Unit, a department within the division of medicine at Leeds University, he gathered around him a succession of research workers, whom he inspired to study aspects of these relationships. The focus was on family studies, as it was thought that genetic factors could be important. The striking association previously noted between sacroiliitis or full-blown ankylosing spondylitis and several of these disorders to be studied - e.g., psoriatic arthritis, ulcerative colitis, and the arthritis associated with Crohn’s disease - was to be central for each of these studies. As a provisional collective name for these possibly related conditions, the term “Spondarthritides” was chosen. These were the days before HLA B27, and so the research tools were simply clinical, radiological (for sacroiliitis and serological (for rheumatoid factor. The research programme confirmed not only links between the primary disorders with ankylosing spondylitis, but also links between the disorders themselves. Over subsequent years, the spondarthritis concept (dubbed by some “The Leeds Idea” has gained further strength from HLA studies internationally. And membership of the group of conditions fulfilling spondarthritis criteria has grown substantially. It is hoped that this now consolidated framework of spondylitis-related entities will pave the way for further research, with exciting prospects of gene-based prevention and/or cure through the increasing sophistication of molecular biology. Key words: Seronegative spondarthritides, psoriatic arthritis, ankylosing spndylitis

  15. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada

    International Nuclear Information System (INIS)

    Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques

  16. Mining Association Rules Between Credits in the Leadership in Energy and Environmental Design for New Construction (LEED-NC) Green Building Assessment System

    National Research Council Canada - National Science Library

    Thomas, Benjamin J

    2008-01-01

    The Leadership in Energy and Environmental Design (LEED) Building Assessment System is a performance-based tool for determining the environmental impact of a facility from the whole-building perspective...

  17. In the spotlight. Interview with Kenneth Lee, Health Economist, University of Leeds, U.K.. Interview by Johannes Stoelwinder.

    Science.gov (United States)

    Lee, K

    1984-01-01

    Ken Lee appointed to the staff of the Nuffield Centre, University of Leeds, as Lecturer in Health Economics in 1970. He is now Senior Lecturer and Director of the Master's Programme in Health Service Studies. His main teaching interests are in health planning and health economics, and he has carried out research and written extensively on approaches to health economics, health planning and management, care of the elderly, primary health care, health financing, and emergency health services.

  18. Translating research into practice in Leeds and Bradford (TRiPLaB: a protocol for a programme of research

    Directory of Open Access Journals (Sweden)

    Bibby John

    2010-05-01

    Full Text Available Abstract Background The National Institute for Health Research (NIHR has funded nine Collaborations for Leadership in Applied Health Research and Care (CLAHRCs. Each CLAHRC is a partnership between higher education institutions (HEIs and the NHS in nine UK regional health economies. The CLAHRC for Leeds, York, and Bradford comprises two 'research themes' and three 'implementation themes.' One of these implementation themes is Translating Research into Practice in Leeds and Bradford (TRiPLaB. TRiPLaB aims to develop, implement, and evaluate methods for inducing and sustaining the uptake of research knowledge into practice in order to improve the quality of health services for the people of Leeds and Bradford. Methods TRiPLaB is built around a three-stage, sequential, approach using separate, longitudinal case studies conducted with collaborating NHS organisations, TRiPLaB will select robust innovations to implement, conduct a theory-informed exploration of the local context using a variety of data collection and analytic methods, and synthesise the information collected to identify the key factors influencing the uptake and adoption of targeted innovations. This synthesis will inform the development of tailored, multifaceted, interventions designed to increase the translation of research findings into practice. Mixed research methods, including time series analysis, quasi-experimental comparison, and qualitative process evaluation, will be used to evaluate the impact of the implementation strategies deployed. Conclusion TRiPLaB is a theory-informed, systematic, mixed methods approach to developing and evaluating tailored implementation strategies aimed at increasing the translation of research-based findings into practice in one UK health economy. Through active collaboration with its local NHS, TRiPLaB aims to improve the quality of health services for the people of Leeds and Bradford and to contribute to research knowledge regarding the

  19. Proceedings of the International Workshop on Computational Electronics Held at Leeds University (United Kingdom) on August 11-13 1993

    Science.gov (United States)

    1993-08-01

    Drury , Sponsored by UK SERC and MIA-COM (USA). Apart from any fair dealing for the purposes of research or private study, or criticism or review, as...field effect 128 transistors R Drury , R E Miles and C M Snowden, University of Leeds Poster Session II Determination of diffusion coefficients and...V V V y V V V Device simulation by means of a direct solution of the coupled Poisson/Boltzmann Transport enuations Conor J. Donnelly and Colin Lyden

  20. Office layout affecting privacy, interaction, and acoustic quality in LEED-certified buildings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young S. [School of Planning, Design, and Construction, Michigan State University, East Lansing, MI 48823 (United States)

    2010-07-15

    The study investigated differences in worker satisfaction and perceived job performance regarding privacy, interaction, and acoustic quality issues in personal workspaces between five office types in LEED-certified buildings. It finds that people in high cubicles showed significantly lower satisfaction and job performance in relation to visual privacy and interaction with co-workers than both enclosed private and enclosed shared office types. They also showed significantly lower satisfaction with noise level and sound privacy and lower job performance perceived by acoustic quality than enclosed private, enclosed shared, and bullpen types. The bullpen type, open-plan office without partitions, presented significantly higher satisfaction with noise level and higher performance perceived by acoustic quality than both high and low cubicles. Considering the bullpen type also showed higher satisfaction with sound privacy than the high cubicle type, high partitions don't seem to contribute to creating workspaces where people can have a secure conversation. The bullpen type didn't show any difference from the enclosed shared type in all privacy, interaction, and acoustic quality questions, indicating it may be a good option for a small office space instead of the enclosed shared type. (author)

  1. Validation study of the Leeds Dyspepsia Questionnaire in a multi-ethnic Asian population.

    Science.gov (United States)

    Mahadeva, Sanjiv; Chan, Wah-Kheong; Mohazmi, Mohammed; Sujarita, Ramanujam; Goh, Khean-Lee

    2011-11-01

    Outcome measures for clinical trials in dyspepsia require an assessment of symptom response. There is a lack of validated instruments assessing dyspepsia symptoms in the Asian region. We aimed to translate and validate the Leeds Dyspepsia Questionnaire (LDQ) in a multi-ethnic Asian population. A Malay and culturally adapted English version of the LDQ were developed according to established protocols. Psychometric evaluation was performed by assessing the validity, internal consistency, test-retest reliability and responsiveness of the instruments in both primary and secondary care patients. Between April and September 2010, both Malay (n=166) and Malaysian English (n=154) versions were assessed in primary and secondary care patients. Both language versions were found to be reliable (internal consistency was 0.80 and 0.74 (Cronbach's α) for Malay and English, respectively; spearman's correlation coefficient for test-retest reliability was 0.98 for both versions), valid (area under receiver operating curve for accuracy of diagnosing dyspepsia was 0.71 and 0.77 for Malay and English versions, respectively), discriminative (median LDQ score discriminated between primary and secondary care patients in Malay (11.0 vs 20.0, PAsian population with dyspepsia. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

  2. LEED, Its Efficacy and Fallacy in a Regional Context—An Urban Heat Island Case in California

    Directory of Open Access Journals (Sweden)

    Min Ho Shin

    2017-09-01

    Full Text Available The use of energy in the building sector has increased rapidly over the past two decades. Accordingly, various building assessment methods have developed in green building practices. However, the questions still remain in regard to how positively green buildings affect regional surroundings. This study investigates the possible relationship between LEED-certified buildings and urban heat island effect. Using GIS with spatial regression, the study found that constructing an LEED building in a 30-m boundary could possibly lower the temperature of the surrounding environment by 0.35 °C. Also, having a higher certification level, such as Gold or Platinum, increased the lowering effect by 0.48 °C, while a lower certification level, such as Certified or Silver, had a lowering effect of 0.26 °C. Although LEED has gained a substantial amount of interest and skepticism at the same time, the study results could be a potential sign that the Sustainable Sites Credits or energy-efficient materials play a positive role in lowering the temperature.

  3. Beneficios económicos de la certificación LEED. Edificio centro Ático: caso de estudio

    Directory of Open Access Journals (Sweden)

    Óscar Ribero

    Full Text Available En el presente artículo se estudian los beneficios económicos de la aplicación del programa de certificación de construcciones sostenibles LEED, en el Edificio Centro Ático situado en Bogotá - Colombia. Inicialmente, se determinan los consumos de agua y energía eléctrica, y los costos de construcción y operación del edificio bajo su diseño original (construido sin tener en cuenta los parámetros establecidos por LEED. Seguido a esto se plantean estrategias para lograr que el edificio Centro Ático alcance la certificación LEED GOLD New Construction V3 2009 y se calculan los incrementos económicos asociados a éstas. Así mismo, se calculan los nuevos consumos de agua y energía eléctrica bajo la aplicación de dichas estrategias (diseño modificado y sus correspondientes costos de operación. Finalmente, se determinan los indicadores de bondad económica de la inversión mediante un análisis de flujo de caja.

  4. Electron spin polarization effects in low-energy electron diffraction, ion neutralization, and metastable-atom deexcitation at solid surfaces. Progress report No. 3, January 1-December 31, 1983

    International Nuclear Information System (INIS)

    Walters, G.K.; Dunning, F.B.

    1983-01-01

    The importance of electron spin polarization (ESP) effects in the various spectroscopies used to study solid surfaces has become increasingly apparent in recent years. Recent low energy electron diffraction (LEED) investigations in this laboratory and elsewhere have shown that a great deal of new information contributing to the understanding of the geometrical arrangements of atoms at a surface can be obtained if the polarization of the various LEED beams is measured, or if the incident electron beam is polarized. Polarized LEED studies have shown large polarization features that are very sensitive to the presence of adsorbed layers, surface reconstruction, etc. In addition, theory suggests that polarization measurements can provide a more sensitive test of many of the parameters used in a surface model than can conventional LEED intensity measurements alone. Polarized LEED has also been applied to the study of surface magnetism. In the present contract year, polarized LEED has been used, together with Auger analysis and LEED intensity measurements, as a diagnostic to characterize Ni(001) surfaces produced by laser annealing

  5. A molecular surface science study of the structure of adsorbates on surfaces: Importance to lubrication

    International Nuclear Information System (INIS)

    Mate, C.M.

    1986-09-01

    The interaction and bonding of atoms and molecules on metal surfaces is explored under ultra-high vacuum conditions using a variety of surface science techniques: high resolution electron energy loss spectroscopy (HREELS), low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES), work function measurements, and second harmonic generation (SHG). 164 refs., 51 figs., 3 tabs

  6. Social determinants of male health: a case study of Leeds, UK.

    Science.gov (United States)

    White, Alan; Seims, Amanda; Cameron, Ian; Taylor, Tim

    2018-01-19

    The social determinants of health have a disproportionate impact on mortality in men. A study into the state of health of the male population in Leeds was undertaken to guide public health commissioning decisions. This paper reports on the data relating to the social lives of men. A cross-sectional study was undertaken, comprising descriptive analysis of data relating to educational attainment, housing, employment (including benefit claimants), marital status and relationships. Data was considered for the whole city and localised at the Middle Super Output Area (MSOA) level and mapped against the Index of Deprivation. Boys' educational attainment was found to be lagging behind girls' from their earliest assessments (Early Years Foundation Stage Profile, 46% vs. 60%, P = 0.00) to GCSEs (53% vs. 63%, P = 0.00), leaving many men with no qualifications. There were 68% more men than women identified as being unemployed, with more men claiming benefits. Men living in social housing are more likely to be housed in high-rise flats. Almost 50% of men aged 16-64 are single, with 2254 lone fathers. There appears to be a lack of sex/gender analysis of current cross city data. In areas of deprivation a complex picture of multiple social problems emerges, with marked gender differences in the social determinants of health, with males seeming to be more negatively affected. There is a need for more focused planning for reaching out and targeting boys and men in the most deprived inner city areas, so that greater efficiency in service delivery can be obtained.

  7. Allbutt of Leeds and Duchenne de Boulogne: Newly discovered insights on Duchenne by a British neuropsychiatrist.

    Science.gov (United States)

    Reynolds, E H; Broussolle, E

    2018-02-01

    It is well-established that Guillaume-Benjamin-Amand Duchenne de Boulogne (1806-1875), and Jean-Martin Charcot (1825-1893) were the founding fathers of Parisian and French neurology during the second half of the 19th century, although much more is known about Charcot than about his "master" Duchenne. In Britain, Thomas Clifford Allbutt (1836-1925) was Leeds' most distinguished physician of the 19th century, eventually becoming Regius Professor of Physic at Cambridge. Allbutt's 1860-1861 year of postgraduate study in Paris and his friendship with Duchenne profoundly influenced his own contributions to nervous system and mental diseases, partly in collaboration with his colleague James Crichton-Browne (1840-1938) at the nearby West Riding Lunatic Asylum in Wakefield, Yorkshire. The present report briefly recalls the careers of Duchenne and Allbutt, and also presents a unique account by Allbutt of Duchenne in action at the height of his powers, investigating and defining the previously uncharted field of neuromuscular diseases with the aid of his localized electrization techniques. This account is discussed in relation to: Duchenne's personality and pioneering neurological achievements; the origins of French neurology; and the development of Anglo-French neurological relationships during the 19th century. Interestingly, both Duchenne and Crichton-Browne separately made important and much-appreciated contributions to the third major book by Charles Darwin (1809-1882), The Expression of the Emotions in Man and Animals, published in 1872. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Strategic energy planning within local authorities in the UK: A study of the city of Leeds

    International Nuclear Information System (INIS)

    Bale, Catherine S.E.; Foxon, Timothy J.; Hannon, Matthew J.; Gale, William F.

    2012-01-01

    This paper considers the development of a strategic energy body in a local authority in the UK and looks at the perceived need for, and possible roles of, such a body. Historically, energy provision and management has not usually been a strategic priority for UK local authorities. Yet energy considerations are implicit in key local authority responsibilities such as transport, waste management, planning, and the provision of housing services. In addition, recent UK central government policies support the move to localism and provide incentives for low-carbon energy generation. A study was undertaken to assess the potential (including both the perceived benefits and actual capacity to deliver) for Leeds City Council to develop a strategic body to execute delivery of city-level energy decision-making. We examine the perceived benefits to a range of main stakeholders, using data drawn from interviews with managers responsible for low-carbon and renewable energy projects across the city. Through participant observation we explore the capacity of a local authority to deliver a strategic energy body, and we briefly examine the possible forms of delivery. We conclude with recommendations for national policy that would enable the development of strategic energy bodies across local governments in the UK. - Highlights: ► Strategic energy planning is currently not a priority for UK local authorities. ► We present an empirical study of strategic energy planning in local authorities. ► Results from stakeholder interviews suggest support for a strategic energy body. ► We identify the capacity barriers to implementing a strategic energy body. ► We make recommendations for ways forward and support needed from national policy.

  9. Assessing and Developing the Application of LEED Green Building Rating System as a Sustainable Project Management and Market Tool in the Italian Context

    Directory of Open Access Journals (Sweden)

    Walaa S. E. Ismaee

    2016-07-01

    Full Text Available The paper discusses the recent introduction of the LEED system to the Italian context in order to assess its role to promote sustainable building process in the Italian context, pointing out its potentials on one hand as well as their gaps and limitations on the other hand, and suggests means for its future development. The study discusses the application of LEED as a ‘Sustainable Project management tool’ to guide sustainable building performance. This requires investigating the following: its structure, tools, assessment criteria along with its benchmarks and references. It also discusses the application of LEED as a ‘Sustainable building Certification and market tool’. This investigates the role and value of the LEED certification in the Italian Green market. The research method is comprised of three parts. The first part is a comparative analysis of LEED categories against Italian national initiatives for sustainability. The comparison showed that most LEED categories are already mandated by national norms and directives but they may differ in their stringency creating some areas of precedence of LEED system or drawbacks. This streamlines the adaptation process of LEED system to the Italian context. The second part investigates LEED projects’ market analysis. The result showed that the shift towards a sustainable building process is occurring slowly and on a vertical scale focusing on some building sectors rather than others. Its market diffusion in the Italian context faces challenges regarding the insufficient availability of green materials and products satisfying its requirements, as well as high soft cost of sustainability tests and expertise required. The Third part presents a practical review-citing the methodology and results of a survey conducted by the researchers in mid-2012. It is composed of a web-based questionnaire and interviews among a sample of LEED professionals in Italy. The result shows that LEED systems needs

  10. A study of the National Physical Laboratory microdosimetry research programme in collaboration with the University of Leeds

    International Nuclear Information System (INIS)

    Menzel, H.G.

    1987-11-01

    A study of the present programme of work carried out by the National Physical Laboratory and the University of Leeds, has been carried out. The study is based on the use of the tissue-equivalent proportional counter in microdosimetic techniques in radiation protection for monoenergetic neutrons or reference radionuclide neutron sources. This report comments on the programme as a whole and provides recommendations for future research work, taking into account the research programmes carried out at other institutions. It also attempts to summarise the present state of knowledge and experience associated with the application of this technique to radiation fields met in routine radiation protection. (author)

  11. The use of Leeds Test Objects in the assessment of the performance of radiological imaging systems: an introduction

    International Nuclear Information System (INIS)

    Cowen, A.R.

    1986-01-01

    Over the preceding decade the Leeds Radiological Imaging Group have developed a range of test objects with which to assess the performance of radiological imaging systems. The types of imaging equipment which can be assessed include X-ray image intensifier television systems, small-format 100mm/105mm fluorography systems and radiographic screen-film combinations. We have recently extended our interest to the evaluation of digital radiological imaging equipment including digital subtraction fluorography and digital (greyscale) radiographic imaging systems. These test objects were initially developed for the purpose of evaluating imaging performance under laboratory conditions but they have also proved useful under field (clinical) conditions. (author)

  12. ADOÇÃO DA CERTIFICAÇÃO LEED EM MEIOS DE HOSPEDAGEM: ESVERDEANDO A HOTELARIA?

    Directory of Open Access Journals (Sweden)

    Mirna de Lima Medeiros

    2012-03-01

    Full Text Available The research intended to analyze the adoption process of the green certification “Leadership in Energy and Environmental Design” (LEED from the hotel sector establishments that has already adopted it. For its concretization it was proceeded a bibliographical research, secondary fact-gathering in journals, institutional sites and documentaries, and primary fact-gathering by means of semi structured interviews carried out with responsible people of the certified hotels and of the responsible entity of the certification in Brazil (Green Building Council Brazil. There were 21 interviewee, being 02 of the GBC Brazil and 19 of means of lodging (31% of the certified. For data analysis, it was utilized content analysis technique with the aid of ATLAS.ti software. The results permitted to identify the chronology of the processes of certification and the profile of the hotel categories that adopt the LEED program. Beyond that, the interviews enabled the discussion of the initial motivations for seeking the certification, as well the advantages and the obstacles perceived regarding its adoption.

  13. Investigation of the Si(111) surface in uhv: oxidation and the effect of surface phosphorus

    International Nuclear Information System (INIS)

    Tom, H.W.K.; Zhu, X.D.; Shen, Y.R.; Somorjai, G.A.

    1984-06-01

    We have studied the initial stages of oxidation, the segregation of phosphorus, and the effect of phosphorus on oxidation of the Si(111) 7 x 7 surface using optical second-harmonic generation. We have also observed a (√3 x √3)R30 0 LEED pattern for P on Si

  14. From surface to volume plasmons in hyperbolic metamaterials: General existence conditions for bulk high-k waves in metal-dielectric and graphene-dielectric multilayers

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Andryieuski, Andrei; Sipe, John E.

    2014-01-01

    -dielectric and recently introduced graphene-dielectric stacks. We confirm that short-range surface plasmons in thin metal layers can give rise to hyperbolic metamaterial properties and demonstrate that long-range surface plasmons cannot. We also show that graphene-dielectric multilayers tend to support high- k waves...

  15. Effects of Contract Delivery Method on the LEED(trademark) Score of U.S. Navy Military Construction Projects (Fiscal Years 2004-2006) (CD-ROM)

    National Research Council Canada - National Science Library

    Carpenter, Deanna S

    2005-01-01

    ...: 1 CD-ROM; 4 3/4 in.; 484 KB. ABSTRACT: This research study focused on determining the effects that the two major contract delivery methods had on the LEED score of projects over the design and construction time horizon...

  16. Producing 'internal suspect bodies': divisive effects of UK counter-terrorism measures on Muslim communities in Leeds and Bradford.

    Science.gov (United States)

    Abbas, Madeline-Sophie

    2018-04-06

    Research on UK government counter-terrorism measures has claimed that Muslims are treated as a 'suspect community'. However, there is limited research exploring the divisive effects that membership of a 'suspect community' has on relations within Muslim communities. Drawing from interviews with British Muslims living in Leeds or Bradford, I address this gap by explicating how co-option of Muslim community members to counter extremism fractures relations within Muslim communities. I reveal how community members internalize fears of state targeting which precipitates internal disciplinary measures. I contribute the category of 'internal suspect body' which is materialized through two intersecting conditions within preventative counter-terrorism: the suspected extremist for Muslims to look out for and suspected informer who might report fellow Muslims. I argue that the suspect community operates through a network of relations by which terrors of counter-terrorism are reproduced within Muslim communities with divisive effects. © London School of Economics and Political Science 2018.

  17. Challenging Racist Violence and Racist Hostility in 'Post-Racial' Times: Research and Action in Leeds, UK, 2006–2012

    Directory of Open Access Journals (Sweden)

    Ian Law

    2013-04-01

    Full Text Available Despite increasing understanding of, information about and official commitment to challenge these patterns, racist hostility and violence continue to have an enduring presence in urban and rural life in the UK. This indicates the paradoxical nature of this racial crisis and challenges for antiracism as a political project. This paper charts how these issues play out at the local level through an examination of a five year process from problem identification through to research, response, action and aftermath from 2006 to 2012 in the city of Leeds, UK, with a focus on two predominantly white working class social housing estates in the city. We explore how embedded tensions and antagonisms can begin to be challenged, while examining how the contemporary climate of austerity and cuts in services, together with prevailing post-racial thinking, make the likelihood of such concerted action in the UK increasingly remote.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-01

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

  19. Life Cycle Assessment and Optimization-Based Decision Analysis of Construction Waste Recycling for a LEED-Certified University Building

    Directory of Open Access Journals (Sweden)

    Murat Kucukvar

    2016-01-01

    Full Text Available The current waste management literature lacks a comprehensive LCA of the recycling of construction materials that considers both process and supply chain-related impacts as a whole. Furthermore, an optimization-based decision support framework has not been also addressed in any work, which provides a quantifiable understanding about the potential savings and implications associated with recycling of construction materials from a life cycle perspective. The aim of this research is to present a multi-criteria optimization model, which is developed to propose economically-sound and environmentally-benign construction waste management strategies for a LEED-certified university building. First, an economic input-output-based hybrid life cycle assessment model is built to quantify the total environmental impacts of various waste management options: recycling, conventional landfilling and incineration. After quantifying the net environmental pressures associated with these waste treatment alternatives, a compromise programming model is utilized to determine the optimal recycling strategy considering environmental and economic impacts, simultaneously. The analysis results show that recycling of ferrous and non-ferrous metals significantly contributed to reductions in the total carbon footprint of waste management. On the other hand, recycling of asphalt and concrete increased the overall carbon footprint due to high fuel consumption and emissions during the crushing process. Based on the multi-criteria optimization results, 100% recycling of ferrous and non-ferrous metals, cardboard, plastic and glass is suggested to maximize the environmental and economic savings, simultaneously. We believe that the results of this research will facilitate better decision making in treating construction and debris waste for LEED-certified green buildings by combining the results of environmental LCA with multi-objective optimization modeling.

  20. Atmospheric deterioration of clean surface of epitaxial (001)-YBaCuO films studied by low-energy electron diffraction

    International Nuclear Information System (INIS)

    Ohara, Tomoyuki; Sakuta, Ken; Kamishiro, Makio; Kobayashi, Takeshi

    1991-01-01

    The effects of gas exposure on the clean surface of the epitaxial YBaCuO thin films were closely investigated using the low-energy electron diffraction (LEED) method. The clean surface was obtained by in-vacuum annealing at 500degC. Once the clean surface was exposed to air, even at room temperature, the LEED spots disappeared or sometimes became faint. To ensure the degradation mechanism of the YBaCuO clean surface, the specimens were exposed to pure O 2 and N 2 gases separately and measured by LEED. As a result, it was found that O 2 is very safe but N 2 serves as a poisonous gas for the YBaCuO clean surface. (author)

  1. Electrodynamical forbiddance of a strong quadrupole interaction in surface enhanced optical processes. Experimental confirmation of the existence in fullerene C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Polubotko, A. M., E-mail: alex.marina@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Chelibanov, V. P., E-mail: Chelibanov@gmail.com [State University of Information Technologies, Mechanics and Optics (Russian Federation)

    2017-02-15

    It is demonstrated that in the SERS and SEIRA spectra of the fullerene C{sub 60}, the lines, which are forbidden in usual Raman and IR spectra and allowed in SERS and SEIRA, are absent. In addition the enhancement SERS coefficient in a single molecule detection regime is ~10{sup 8} instead of the value 10{sup 14}–10{sup 15}, characteristic for this phenomenon. These results are explained by the existence of so-called electrodynamical forbiddance of a strong quadrupole light-molecule interaction, which arises because of belonging of C{sup 60} to the icosahedral symmetry group and due to the electrodynamical law divE = 0.

  2. Pair momentum distribution in Bi2Sr2CaCu2O8+δ measured by positron annihilation: Existence and nature of the Fermi surface

    International Nuclear Information System (INIS)

    Chan, L.P.; Harshman, D.R.; Lynn, K.G.; Massidda, S.; Mitzi, D.B.

    1991-01-01

    We report the first measurement of the positron-electron momentum density in superconducting single-crystal Bi 2 Sr 2 CaCu 2 O 8+δ (T c ∼90 K). The observed anisotropy exhibits a twofold (rather than fourfold) symmetry, which is attributed to the superlattice modulation along the b axis of the BiO 2 layers. Subtraction of the superlattice contribution also reveals a pair momentum distribution consistent with the CuO 2 and BiO 2 Fermi surfaces, and in reasonable agreement with the theoretical pair momentum density derived from band theory

  3. Pair momentum distribution in Bi2Sr2CaCu2O(8+delta) measured by positron annihilation - Existence and nature of the Fermi surface

    Science.gov (United States)

    Chan, L. P.; Lynn, K. G.; Harshman, D. R.; Massidda, S.; Mitzi, D. B.

    1991-09-01

    The first measurement is reported of the position-electron momentum density in superconducting single-crystal Bi2Sr2CaCu2O(8+delta)(Tc roughly 90 K). The observed anisotropy exhibits a twofold (rather than fourfold) symmetry, which is attributed to the superlattice modulation along the b axis of the BiO2 layers. Subtraction of the superlattice contribution also reveals a pair momentum distribution consistent with the CuO2 and BiO2 Fermi surfaces, and in reasonable agreement with the theoretical pair momentum density derived from band theory.

  4. Uses of ANSI/HPS N13.12-1999, "Surface and Volume Radioactivity Standards for Clearance" and Comparison with Existing Standards

    Energy Technology Data Exchange (ETDEWEB)

    Stansbury, Paul S.; Strom, Daniel J.

    2001-04-30

    In August of 1999, the American National Standards Institute (ANSI) approved a standard for clearance of materials contaminated with residual levels of radioactivity. "Clearance," as used in the standard, means the movement of material from the control of a regulatory agency to a use or disposition that has no further regulatory controls of any kind. The standard gives derived screening levels (DSLs) in Bq/g and Bq/cm2 for 50 radionuclides. Items or materials with residual surface and volume radioactivity levels below the DSLs can be cleared, that is, managed without regard to their residual radioactivity. Since federal agencies are to use voluntary, industry standards developed by the private sector whenever possible, the standard should play an important role in DOE's regulatory process. The thrust of this report is to explain the standard, make simple observations on its usefulness to DOE, and to explore uses of the standard within DOE facilities beyond the clearance of radioactive materials.

  5. LEED AND THE DESIGN/BUILD EXPERIENCE: A SHELTER FOR HOMELESS FAMILIES RETURNING TO POST-KATRINA NEW ORLEANS.

    Directory of Open Access Journals (Sweden)

    Stephen Verderber

    2011-03-01

    Full Text Available Hurricane Katrina displaced nearly one million citizens from the New Orleans metro region in 2005. Five years after the catastrophe, in August of 2010, more than 150,000 citizens remained scattered across the United States. Katrina was the largest Diaspora in the nation’s history. The number of homes damaged or destroyed by Katrina’s devastation numbered more than 125,000. An award-winning case study is presented of a unique partnership forged between academia, a local social service agency, professional architectural and engineering firms, and a national humanitarian aid organization whose mission is to provide affordable housing for homeless persons in transition. This collaboration resulted in a sustainable design/build project that originated in a research-based university design studio. The facility is a 38-bed family shelter for homeless mothers and their children seeking to rebuild their lives in post-Katrina New Orleans. The site for this 4,400 facility did not flood when the city’s federally built levee system failed in 2005. This case study is presented from its inception, to programming and design, construction, occupancy, and the postoccupancy assessment of the completed building. This facility is the first LEED certified (Silver building in New Orleans. Project limitations, lessons learned, and recommendations for future initiatives of this type are discussed, particularly in the context of any inner urban community coping with the aftermath of an urban disaster.

  6. Structure and grain coarsening during the processing of engineering ceramics. Ph.D. Thesis - Leeds Univ., United Kingdom

    Science.gov (United States)

    Shaw, Nancy J.

    1987-01-01

    Studies have been made of three ceramic systems (Al2O3, Y2O3/MgO, and SiC/C/B), both to explore a surface area/density diagram approach to examining the coarsening processes during sintering and to explore an alternative coarsening parameter, i.e., the grain boundary surface area (raising it at a given value of the density) and not the pore surface area; therefore, pinning of the grain boundaries by solid-solution drag is the only function evidenced by these results. The importance of such pinning even at densities as low as 75% of theoretical is linked to the existence of microstructural inhomogeneities. The early stages of sintering of Y2O3 powder have been examined using two techniques, BET surface area analysis and transmission electron microscopy. Each has given some insight into the process occurring and, used together, have provided some indication of the effect of MgO on coarsening during sintering. Attempts to further elucidate effects of MgO on the coarsening behavior of Y2O3 by the surface area/density diagram approach were unsuccessful due to masking effects of contaminating reactions during sintering and/or thermal etching. The behavior of the undoped SiC which only coarsens can be clearly distinguished by the surface area/density diagram from that of SiC/C/B which also concurrently densifies. Little additional information was obtainable by this method due to unfavorable sample etching characteristics. The advantages, disadvantages, and difficulties of application of these techniques to the study of coarsening during sintering are discussed.

  7. Structure of solid surfaces and of adsorbates by low-energy electron diffraction

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1977-01-01

    LEED theory has developed to the point where the diffraction beam intensities can be computed using the locations of the surface atoms as the only adjustable parameters. The position of atoms in many clean monatomic solid surfaces and the surface structures of ordered monolayers of adsorbed atoms have been determined this way. Surface crystallography studies are now extended to small hydrocarbon molecules that are adsorbed on metal surfaces. These studies are reviewed

  8. Structural and vibrational studies of clean and chemisorbed metal surfaces

    International Nuclear Information System (INIS)

    Jiang, Qing-Tang.

    1992-01-01

    Using Medium Energy Ion Scattering, we have studied the structural and vibrational properties of a number of clean and chemisorbed metal surfaces. The work presented in this thesis is mainly of a fundamental nature. However, it is believed that an atomistic understanding of the forces that affect surface structural and vibrational properties can have a beneficial impact on a large number of areas of applied nature. We find that the surface structure of Cu(001) follows the common trend for metal surfaces, where a small oscillatory relaxation exists beginning with a slight contraction in the top layer. In addition, the surface vibrational amplitude is enhanced (as s usually the case) by ∼80%. A detailed analysis of our data shows an unexpected anisotropy of the vibrational amplitude, such that the out-of-plane vibrational amplitude is 30% smaller than the in-plane vibrational amplitude. The unexpected results may imply a large tensile stress on Cu(001). Upon adsorption of 1/4 of a monolayer of S, a p(2 x 2)-S/Cu(001) surface is created. This submonolayer amount of S atoms makes the surface bulk-like, in which the anisotropy of the surface vibrations is removed and the first interlayer contraction is lifted. By comparing our model to earlier contradictory results on this controversial system. We find excellent agreement with a recent LEED study. The presence of 0.1 monolayer of Ca atoms on the Au(113) surface induces a drastic atomic rearrangements, in which half of the top layer Au atoms are missing and a (1 x 2) symmetry results. In addition, the first interlayer spacing of Au(113) is significantly reduced. Our results are discussed in terms of the energy balance between competing surface electronic charge densities

  9. [Inelastic electron scattering from surfaces

    International Nuclear Information System (INIS)

    1993-01-01

    This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned

  10. A cross sectional study investigating the association between exposure to food outlets and childhood obesity in Leeds, UK.

    Science.gov (United States)

    Griffiths, Claire; Frearson, Anna; Taylor, Adam; Radley, Duncan; Cooke, Carlton

    2014-12-06

    Current UK policy in relation to the influence of the 'food environment' on childhood obesity appears to be driven largely on assumptions or speculations because empirical evidence is lacking and findings from studies are inconsistent. The aim of this study was to investigate the number of food outlets and the proximity of food outlets in the same sample of children, without solely focusing on fast food. Cross sectional study over 3 years (n = 13,291 data aggregated). Body mass index (BMI) was calculated for each participant, overweight and obesity were defined as having a BMI >85(th) (sBMI 1.04) and 95(th) (sBMI 1.64) percentiles respectively (UK90 growth charts). Home and school neighbourhoods were defined as circular buffers with a 2 km Euclidean radius, centred on these locations. Commuting routes were calculated using the shortest straight line distance, with a 2 km buffer to capture varying routes. Data on food outlet locations was sourced from Leeds City Council covering the study area and mapped against postcode. Food outlets were categorised into three groups, supermarkets, takeaway and retail. Proximity to the nearest food outlet in the home and school environmental domain was also investigated. Age, gender, ethnicity and deprivation (IDACI) were included as covariates in all models. There is no evidence of an association between the number of food outlets and childhood obesity in any of these environments; Home Q4 vs. Q1 OR = 1.11 (95% CI = 0.95-1.30); School Q4 vs. Q1 OR = 1.00 (95% CI 0.87 - 1.16); commute Q4 vs. Q1 OR = 0.1.00 (95% CI 0.83 - 1.20). Similarly there is no evidence of an association between the proximity to the nearest food outlet and childhood obesity in the home (OR = 0.77 [95% CI = 0.61 - 0.98]) or the school (OR = 1.01 [95% CI 0.84 - 1.23]) environment. This study provides little support for the notion that exposure to food outlets in the home, school and commuting neighbourhoods increase the risk of obesity

  11. Requirements for existing buildings

    DEFF Research Database (Denmark)

    Thomsen, Kirsten Engelund; Wittchen, Kim Bjarne

    This report collects energy performance requirements for existing buildings in European member states by June 2012.......This report collects energy performance requirements for existing buildings in European member states by June 2012....

  12. Greening Existing Tribal Buildings

    Science.gov (United States)

    Guidance about improving sustainability in existing tribal casinos and manufactured homes. Many steps can be taken to make existing buildings greener and healthier. They may also reduce utility and medical costs.

  13. Surface structure determination of group 11 metals adsorbed on a rhenium(10 anti 10) surface by low-energy electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Messahel, Lyria

    2012-11-12

    This thesis deals with the computational surface determination of various long-range ordered phases formed by thin films of copper, silver, and gold adsorbed on the rhenium- (10 anti 10) surface. It is based upon LEED-I,V curves for these phases that were recorded in the course of detailed experimental investigations of the respective films carried out in our group (using techniques such as LEED, MEED, and TPD). In order to solve the intricate puzzle of surface structural analysis, the electron elastic scattering behaviour of the investigated coinage metal phases was calculated using the Erlangen TensErLEED program package. Thereby first a set of theoretical LEED-I,V curves is derived for a guessed reference structure. Subsequently its structural input parameters are varied in a trial-and-error procedure until optimal agreement between experiment and theory is attained. The (1 x 1) phases formed by the deposited metals were tackled first to establish an absolute coverage calibration and to elucidate the respective growth modes on the Re(10 anti 10) surface. In all three cases the (1 x 1) structure is developed best at a coverage {Theta}{sub Cu,Ag,Au}=2 ML=1 BL. Extension of the investigation to experimental I,V curves for higher Cu coverages revealed that this element continues to grow bilayerwise, thereby retaining the Re hcp morphology. Ag, in contrast to Cu and Au, happens not to grow as homogeneously, and the TPD data suggest that Ag films exhibit the so-called simultaneous-multilayer (SM) growth mode. The following analysis of the sub-bilayer coverage range shows that the three systems exhibit considerable differences. While Cu, having a negative lattice misfit compared to Re, shows no long-range ordered superstructures, Ag and Au with a similar positive misfit form a couple of such phases. Ag features both a (1 x 4) phase, stable at ambient temperatures, that upon heating transforms into a c(2 x 2) phase that only exists at elevated temperatures. The

  14. Surface structure determination of group 11 metals adsorbed on a rhenium(10 anti 10) surface by low-energy electron diffraction

    International Nuclear Information System (INIS)

    Messahel, Lyria

    2012-01-01

    This thesis deals with the computational surface determination of various long-range ordered phases formed by thin films of copper, silver, and gold adsorbed on the rhenium- (10 anti 10) surface. It is based upon LEED-I,V curves for these phases that were recorded in the course of detailed experimental investigations of the respective films carried out in our group (using techniques such as LEED, MEED, and TPD). In order to solve the intricate puzzle of surface structural analysis, the electron elastic scattering behaviour of the investigated coinage metal phases was calculated using the Erlangen TensErLEED program package. Thereby first a set of theoretical LEED-I,V curves is derived for a guessed reference structure. Subsequently its structural input parameters are varied in a trial-and-error procedure until optimal agreement between experiment and theory is attained. The (1 x 1) phases formed by the deposited metals were tackled first to establish an absolute coverage calibration and to elucidate the respective growth modes on the Re(10 anti 10) surface. In all three cases the (1 x 1) structure is developed best at a coverage Θ Cu,Ag,Au =2 ML=1 BL. Extension of the investigation to experimental I,V curves for higher Cu coverages revealed that this element continues to grow bilayerwise, thereby retaining the Re hcp morphology. Ag, in contrast to Cu and Au, happens not to grow as homogeneously, and the TPD data suggest that Ag films exhibit the so-called simultaneous-multilayer (SM) growth mode. The following analysis of the sub-bilayer coverage range shows that the three systems exhibit considerable differences. While Cu, having a negative lattice misfit compared to Re, shows no long-range ordered superstructures, Ag and Au with a similar positive misfit form a couple of such phases. Ag features both a (1 x 4) phase, stable at ambient temperatures, that upon heating transforms into a c(2 x 2) phase that only exists at elevated temperatures. The structure

  15. ''House in park'' gold plated. Subsequent certification for the new office building; ''Haus im Park'' vergoldet. Nachtraegliche LEED-Zertifizierung fuer neues Buerogebaeude

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Kati; Wildhack, Alice [Bilfinger Berger AG, Mannheim (Germany). Abt. Nachhaltigkeit/Energieeffizienz

    2011-07-01

    In March 2011, the ''house in park'' received the signet LEED {sup registered} of the U.S. Green Building Council (Washington, North Carolina, U.S.A.) in ''gold''. In general, it is the second German project that was awarded with ''gold'' in the certification version ''New Construction, version 2009''. The special challenge: In the planning phase, no aspects relevant to planning and execution with regard to LEED were implemented. In total there are 15 LEED-certified buildings actually in Germany (worldwide: 7,894). 115 Projects are registered (worldwide: 23,238). The trend is increasing, both nationally as well as internationally.

  16. Realities of and perspectives for languages in the globalised world: Can language teaching survive the inadequacies of policies implemented today at Leeds Beckett University?

    Directory of Open Access Journals (Sweden)

    Saadia Gamir

    2017-06-01

    Full Text Available Various newspaper articles report that British ministers, university representatives, exam chiefs and business bodies agree that foreign languages skills in primary, secondary and tertiary UK education are in crisis. Lower funding and policy changes have caused language skills deficiencies felt gravely in the business sectors. Funding and support initiatives pledged by policy makers appear to be election-driven, barely outliving newly elected governments. Others blame secondary school language curriculum for failing to inspire students to take up a language when they reach 13 or 14. Others still argue that severe A-level examinations marking deters students from taking up a foreign language at 6th form level, producing fewer prospective language learners for university departments. Community languages are also undervalued as small-entry languages could soon be axed from GCSE and A-level examinations. In a world increasingly interconnected, it is essential the importance of language learning be reinstated in all our educational institutions. This paper reviews two decades of the conditions of language provision in the UK in general, with an emphasis on Leeds Beckett University. It also attempts to answer two questions emerging form the author’s personal teaching experience and reflections: What are the realities and challenges language teaching faces at Leeds Beckett University? And, how may we support language learners in fulfilling their ambition to acquire the required skills to communicate effectively in this globalised world?

  17. Establishing daily quality control (QC) in screen-film mammography using leeds tor (max) phantom at the breast imaging unit of USTH-Benavides Cancer Institute

    Science.gov (United States)

    Acaba, K. J. C.; Cinco, L. D.; Melchor, J. N.

    2016-03-01

    Daily QC tests performed on screen film mammography (SFM) equipment are essential to ensure that both SFM unit and film processor are working in a consistent manner. The Breast Imaging Unit of USTH-Benavides Cancer Institute has been conducting QC following the test protocols in the IAEA Human Health Series No.2 manual. However, the availability of Leeds breast phantom (CRP E13039) in the facility made the task easier. Instead of carrying out separate tests on AEC constancy and light sensitometry, only one exposure of the phantom is done to accomplish the two tests. It was observed that measurements made on mAs output and optical densities (ODs) using the Leeds TOR (MAX) phantom are comparable with that obtained from the usual conduct of tests, taking into account the attenuation characteristic of the phantom. Image quality parameters such as low contrast and high contrast details were also evaluated from the phantom image. The authors recognize the usefulness of the phantom in determining technical factors that will help improve detection of smallest pathological details on breast images. The phantom is also convenient for daily QC monitoring and economical since less number of films is expended.

  18. Pressure RElieving Support SUrfaces: a Randomised Evaluation 2 (PRESSURE 2): study protocol for a randomised controlled trial.

    Science.gov (United States)

    Brown, Sarah; Smith, Isabelle L; Brown, Julia M; Hulme, Claire; McGinnis, Elizabeth; Stubbs, Nikki; Nelson, E Andrea; Muir, Delia; Rutherford, Claudia; Walker, Kay; Henderson, Valerie; Wilson, Lyn; Gilberts, Rachael; Collier, Howard; Fernandez, Catherine; Hartley, Suzanne; Bhogal, Moninder; Coleman, Susanne; Nixon, Jane E

    2016-12-20

    Pressure ulcers represent a major burden to patients, carers and the healthcare system, affecting approximately 1 in 17 hospital and 1 in 20 community patients. They impact greatly on an individual's functional status and health-related quality of life. The mainstay of pressure ulcer prevention practice is the provision of pressure redistribution support surfaces and patient repositioning. The aim of the PRESSURE 2 study is to compare the two main mattress types utilised within the NHS: high-specification foam and alternating pressure mattresses, in the prevention of pressure ulcers. PRESSURE 2 is a multicentre, open-label, randomised, double triangular, group sequential, parallel group trial. A maximum of 2954 'high-risk' patients with evidence of acute illness will be randomised on a 1:1 basis to receive either a high-specification foam mattress or alternating-pressure mattress in conjunction with an electric profiling bed frame. The primary objective of the trial is to compare mattresses in terms of the time to developing a new Category 2 or above pressure ulcer by 30 days post end of treatment phase. Secondary endpoints include time to developing new Category 1 and 3 or above pressure ulcers, time to healing of pre-existing Category 2 pressure ulcers, health-related quality of life, cost-effectiveness, incidence of mattress change and safety. Validation objectives are to determine the responsiveness of the Pressure Ulcer Quality of Life-Prevention instrument and the feasibility of having a blinded endpoint assessment using photography. The trial will have a maximum of three planned analyses with unequally spaced reviews at event-driven coherent cut-points. The futility boundaries are constructed as non-binding to allow a decision for stopping early to be overruled by the Data Monitoring and Ethics Committee. The double triangular, group sequential design of the PRESSURE 2 trial will provide an efficient design through the possibility of early stopping for

  19. The transition from the adsorbed state to a surface alloy in the Sn/Ni(111) system

    Czech Academy of Sciences Publication Activity Database

    Karakalos, S.; Kennou, S.; Ladas, S.; Janeček, P.; Šutara, F.; Nehasil, V.; Fabík, S.; Tsud, N.; Prince, K. C.; Matolín, V.; Cháb, Vladimír

    2006-01-01

    Roč. 600, - (2006), s. 4067-4071 ISSN 0039-6028 Grant - others:Greek-Czech Bilateral Project(GR) KONTAKT 2003-2005 Institutional research plan: CEZ:AV0Z10100521 Keywords : nickel * tin * surface alloying * synchrotron radiation photoelectron spectroscopy * LEED * CO adsorption Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.880, year: 2006

  20. Surface alloy formation by adsorption of holmium on Ag/Mo(112) bimetallic surfaces

    Science.gov (United States)

    Kołaczkiewicz, Jan; Oleksy, Czesław

    2018-03-01

    Work function change measurements, low energy electron diffraction (LEED) and density functional theory (DFT) are used to determine the structures formed on Ag/Mo(112) bimetallic surfaces upon deposition of 0.5 monolayer (ML) of holmium. As the bimetallic surfaces, we have chosen the Mo(112) substrate covered with 1 or 2 ML of Ag. Such surfaces have the same symmetry as the Mo(112) face but different electronic properties. LEED experiment indicates that the c(2 × 2) structure is formed on (1 ML Ag)/Mo(112) bimetallic surface upon deposition of 0.5 ML of Ho. DFT calculations show that a type of Ag-Ho surface alloy is formed, with Ho atoms 0.6 Å below the distorted layer of Ag. This is neither a substitutional nor a subsurface alloy. It is found that the adsorption structure formed on the (2 ML Ag)/Mo(112) bimetallic surface depends on the annealing temperature. After deposition of 0.5 ML of Ho at 300 K, the LEED pattern of p(2 × 2) symmetry is observed. Annealing of the overlayer at 640 K irreversibly changes the p(2 × 2) pattern into a pattern of c(2 × 2) type. The results of DFT computations show that the c(2 × 2) structure of the Ag-Ho surface alloy is energetically most favorable. In this structure, 0.5 ML of Ho is between the two monolayers of Ag, and the symmetry of the topmost layer is changed. The work function change calculated for the c(2 × 2) structure is in a good agreement with the measured value (0.22 eV). The results show that adsorption of Ho on the Ag/Mo(112) bimetallic surfaces is substantially different than on the clean Mo(112).

  1. Interface formation between hydrocarbon ring molecules and III-V semiconductor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Passmann, Regina

    2008-08-15

    In this work a systematical study to investigate the adsorption structures of small hydrocarbon ring shaped molecules on III-V semiconductor surfaces with Photo-Emission Spectroscopy (PES), Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunneling Microscopy (STM) as well as Low Electron Energy Diffraction (LEED) was performed. To investigate the influence of the surface structure in detail the surface dimer configuration to the adsorption process of organic molecules GaAs(001) surfaces, the c(4 x 4), the (2 x 4) and the (4 x 2) have been investigated as well as the adsorption of cyclopentene on the InP(001)(2 x 4) reconstructed surface. In the direct comparison it is shown that cyclopentene bonds to the InP(001)(2 x 4) surface via a cycloaddition like reaction. During this adsorption the double bond splits which is in contrast to the adsorption of cyclopentene on the GaAs(001) surfaces. Therefrom it is concluded that the surface geometry has an influence on the resulting adsorption structure. In order to investigate the influence of the intra-molecular double bonds, cyclopentene (one double bond), 1,4-cyclohexadiene (two double bonds) and benzene (three double bonds) were used for the characterization of the interface formation. With the investigations on the GaAs(001) reconstructed surfaces it was shown that a dependency of the bonding configuration on the intra-molecular double bonds exists. During the adsorption of cyclopentene no evidence was found that the double bond has to be involved in the interface formation while during the adsorption of 1,4-cyclohexadiene and benzene the double bonds are involved. Furthermore it was found that a bonding to As atoms of the surface is more likely than a bonding to Ga atoms. (orig.)

  2. Interface formation between hydrocarbon ring molecules and III-V semiconductor surfaces

    International Nuclear Information System (INIS)

    Passmann, Regina

    2008-01-01

    In this work a systematical study to investigate the adsorption structures of small hydrocarbon ring shaped molecules on III-V semiconductor surfaces with Photo-Emission Spectroscopy (PES), Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunneling Microscopy (STM) as well as Low Electron Energy Diffraction (LEED) was performed. To investigate the influence of the surface structure in detail the surface dimer configuration to the adsorption process of organic molecules GaAs(001) surfaces, the c(4 x 4), the (2 x 4) and the (4 x 2) have been investigated as well as the adsorption of cyclopentene on the InP(001)(2 x 4) reconstructed surface. In the direct comparison it is shown that cyclopentene bonds to the InP(001)(2 x 4) surface via a cycloaddition like reaction. During this adsorption the double bond splits which is in contrast to the adsorption of cyclopentene on the GaAs(001) surfaces. Therefrom it is concluded that the surface geometry has an influence on the resulting adsorption structure. In order to investigate the influence of the intra-molecular double bonds, cyclopentene (one double bond), 1,4-cyclohexadiene (two double bonds) and benzene (three double bonds) were used for the characterization of the interface formation. With the investigations on the GaAs(001) reconstructed surfaces it was shown that a dependency of the bonding configuration on the intra-molecular double bonds exists. During the adsorption of cyclopentene no evidence was found that the double bond has to be involved in the interface formation while during the adsorption of 1,4-cyclohexadiene and benzene the double bonds are involved. Furthermore it was found that a bonding to As atoms of the surface is more likely than a bonding to Ga atoms. (orig.)

  3. Anomalous structural evolution and √ 3 x√ 3 reconstruction of a clean Si(111) surface observed after thermal desorption of thallium

    Czech Academy of Sciences Publication Activity Database

    Kocán, P.; Krejčí, Ondřej; Tochihara, H.

    2015-01-01

    Roč. 33, č. 2 (2015), "021408-1"-"021408-8" ISSN 0734-2101 Institutional support: RVO:68378271 Keywords : surface structure * Si(111) * thallium * LEED * STM Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.724, year: 2015

  4. Why preeclampsia still exists?

    Science.gov (United States)

    Chelbi, Sonia T; Veitia, Reiner A; Vaiman, Daniel

    2013-08-01

    Preeclampsia (PE) is a deadly gestational disease affecting up to 10% of women and specific of the human species. Preeclampsia is clearly multifactorial, but the existence of a genetic basis for this disease is now clearly established by the existence of familial cases, epidemiological studies and known predisposing gene polymorphisms. PE is very common despite the fact that Darwinian pressure should have rapidly eliminated or strongly minimized the frequency of predisposing alleles. Consecutive pregnancies with the same partner decrease the risk and severity of PE. Here, we show that, due to this peculiar feature, preeclampsia predisposing-alleles can be differentially maintained according to the familial structure. Thus, we suggest that an optimal frequency of PE-predisposing alleles in human populations can be achieved as a result of a trade-off between benefits of exogamy, importance for maintaining genetic diversity and increase of the fitness owing to a stable paternal investment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Existence of Projective Planes

    OpenAIRE

    Perrott, Xander

    2016-01-01

    This report gives an overview of the history of finite projective planes and their properties before going on to outline the proof that no projective plane of order 10 exists. The report also investigates the search carried out by MacWilliams, Sloane and Thompson in 1970 [12] and confirms their result by providing independent verification that there is no vector of weight 15 in the code generated by the projective plane of order 10.

  6. Does bioethics exist?

    Science.gov (United States)

    Turner, L

    2009-12-01

    Bioethicists disagree over methods, theories, decision-making guides, case analyses and public policies. Thirty years ago, the thinking of many scholars coalesced around a principlist approach to bioethics. That mid-level mode of moral reasoning is now one of many approaches to moral deliberation. Significant variation in contemporary approaches to the study of ethical issues related to medicine, biotechnology and health care raises the question of whether bioethics exists as widely shared method, theory, normative framework or mode of moral reasoning.

  7. Surface structure determinations of crystalline ionic thin films grown on transition metal single crystal surfaces by low energy electron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Joel Glenn [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    The surface structures of NaCl(100), LiF(100) and alpha-MgCl2(0001) adsorbed on various metal single crystals have been determined by low energy electron diffraction (LEED). Thin films of these salts were grown on metal substrates by exposing the heated metal surface to a molecular flux of salt emitted from a Knudsen cell. This method of investigating thin films of insulators (ionic salts) on a conducting substrate (metal) circumvents surface charging problems that plagued bulk studies, thereby allowing the use of electron-based techniques to characterize the surface.

  8. Temperature dependence of rippled corrugations induced on the Rh(1 1 0) surface via ion sputtering

    International Nuclear Information System (INIS)

    Molle, Alessandro; Buatier de Mongeot, F.; Granone, F.; Buzio, R.; Firpo, G.; Boragno, C.; Valbusa, U.

    2005-01-01

    Metal surfaces can be easily nanopatterned via ion sputtering: mounds or ripples can be created depending on the surface symmetry and temperature. However, in many cases these structures are unstable at room temperature and above, due to the adatom fast diffusion. This fact prevents the use of such systems as substrate or nanostamps for a technological implementation. In this paper we present a spot profile analysis low energy electron diffraction (SPA-LEED) study on the nanopatterning of a Rh(1 1 0) single crystal. Like the other (1 1 0) metal surfaces, previously investigated, also Rh(1 1 0) shows for increasing temperatures a transition between different rippled morphologies. The main advantage of this system is its stability at room temperature. From SPA-LEED data we can measure the structural features (average periodicity and local faceting) of the observed rippled structures

  9. O Ponto G Existe?

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Molina Noccioli

    2016-07-01

    Full Text Available Este trabalho busca analisar o tratamento linguístico-discursivo das informações acerca de um tópicotemático tradicionalmente visto como tabu, relacionado a questões sexuais, na notícia O ponto G existe?, publicada em 2008, na revista brasileira Superinteressante, destacando-se como o conhecimento em questão é representado socialmente ao se considerar a linha editorial da revista. A notícia caracteriza-se como um campo fértil para a análise das estratégias divulgativas, já que atrai, inclusive pelas escolhas temáticas, a curiosidade dos leitores. Imbuído de um tema excêntrico, o texto consegue angariar um público jovem interessado em discussões polêmicas relacionadas ao seu universo.

  10. Lebesgue Sets Immeasurable Existence

    Directory of Open Access Journals (Sweden)

    Diana Marginean Petrovai

    2012-12-01

    Full Text Available It is well known that the notion of measure and integral were released early enough in close connection with practical problems of measuring of geometric figures. Notion of measure was outlined in the early 20th century through H. Lebesgue’s research, founder of the modern theory of measure and integral. It was developed concurrently a technique of integration of functions. Gradually it was formed a specific area todaycalled the measure and integral theory. Essential contributions to building this theory was made by a large number of mathematicians: C. Carathodory, J. Radon, O. Nikodym, S. Bochner, J. Pettis, P. Halmos and many others. In the following we present several abstract sets, classes of sets. There exists the sets which are not Lebesgue measurable and the sets which are Lebesgue measurable but are not Borel measurable. Hence B ⊂ L ⊂ P(X.

  11. EXIST Perspective for SFXTs

    Science.gov (United States)

    Ubertini, Pietro; Sidoli, L.; Sguera, V.; Bazzano, A.

    2009-12-01

    Supergiant Fast X-ray Transients (SFXTs) are one of the most interesting (and unexpected) results of the INTEGRAL mission. They are a new class of HMXBs displaying short hard X-ray outbursts (duration less tha a day) characterized by fast flares (few hours timescale) and large dinamic range (10E3-10E4). The physical mechanism driving their peculiar behaviour is still unclear and highly debated: some models involve the structure of the supergiant companion donor wind (likely clumpy, in a spherical or non spherical geometry) and the orbital properties (wide separation with eccentric or circular orbit), while others involve the properties of the neutron star compact object and invoke very low magnetic field values (B 1E14 G, magnetars). The picture is still highly unclear from the observational point of view as well: no cyclotron lines have been detected in the spectra, thus the strength of the neutron star magnetic field is unknown. Orbital periods have been measured in only 4 systems, spanning from 3.3 days to 165 days. Even the duty cycle seems to be quite different from source to source. The Energetic X-ray Imaging Survey Telescope (EXIST), with its hard X-ray all-sky survey and large improved limiting sensitivity, will allow us to get a clearer picture of SFXTs. A complete census of their number is essential to enlarge the sample. A long term and continuous as possible X-ray monitoring is crucial to -(1) obtain the duty cycle, -(2 )investigate their unknown orbital properties (separation, orbital period, eccentricity),- (3) to completely cover the whole outburst activity, (4)-to search for cyclotron lines in the high energy spectra. EXIST observations will provide crucial informations to test the different models and shed light on the peculiar behaviour of SFXTs.

  12. Surface, segregation profile for Ni50Pd50(100)

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Ruban, Andrei; Skriver, Hans Lomholt

    1997-01-01

    A recent dynamical LEED study [G.N. Derry, C.B. McVey, P.J. Rous, Surf. Sci. 326 (1995) 59] reported an oscillatory surface segregation profile in the Ni50Pd50(100) system with the surface layer enriched by Pd. We have performed ab-initio total-energy calculations for the surface of this alloy...... system using the coherent potential approximation and obtain an oscillatory segregation profile, in agreement with experiments. We discuss the energetic origin of the oscillatory segregation profile in terms of effective cluster interactions. We include relaxation effects by means of the semi...

  13. Solving complex and disordered surface structures with electron diffraction

    International Nuclear Information System (INIS)

    Van Hove, M.A.

    1987-10-01

    The past of surface structure determination with low-energy electron diffraction (LEED) will be briefly reviewed, setting the stage for a discussion of recent and future developments. The aim of these developments is to solve complex and disordered surface structures. Some efficient solutions to the theoretical and experimental problems will be presented. Since the theoretical problems dominate, the emphasis will be on theoretical approaches to the calculation of the multiple scattering of electrons through complex and disordered surfaces. 49 refs., 13 figs., 1 tab

  14. Direct observation for atomically flat and ordered vertical {111} side-surfaces on three-dimensionally figured Si(110) substrate using scanning tunneling microscopy

    Science.gov (United States)

    Yang, Haoyu; Hattori, Azusa N.; Ohata, Akinori; Takemoto, Shohei; Hattori, Ken; Daimon, Hiroshi; Tanaka, Hidekazu

    2017-11-01

    A three-dimensional Si{111} vertical side-surface structure on a Si(110) wafer was fabricated by reactive ion etching (RIE) followed by wet-etching and flash-annealing treatments. The side-surface was studied with scanning tunneling microscopy (STM) in atomic scale for the first time, in addition to atomic force microscopy (AFM), scanning electron microscopy (SEM), and low-energy electron diffraction (LEED). AFM and SEM showed flat and smooth vertical side-surfaces without scallops, and STM proved the realization of an atomically-flat 7 × 7-reconstructed structure, under optimized RIE and wet-etching conditions. STM also showed that a step-bunching occurred on the produced {111} side-surface corresponding to a reversely taped side-surface with a tilt angle of a few degrees, but did not show disordered structures. Characteristic LEED patterns from both side- and top-reconstructed surfaces were also demonstrated.

  15. Surface science principles and current applications

    CERN Document Server

    Taglauer, E; Wandelt, K

    1996-01-01

    Modern technologies increasingly rely on low-dimensional physics at interfaces and in thin-films and nano-structures. Surface science holds a key position in providing the experimental methods and theoretical models for a basic understanding of these effects. This book includes case studies and status reports about research topics such as: surface structure determination by tensor-LEED and surface X-ray diffraction; the preparation and detection of low-dimensional electronic surface states; quantitative surface compositional analysis; the dynamics of adsorption and reaction of adsorbates, e.g. kinetic oscillations; the characterization and control of thin-film and multilayer growth including the influence of surfactants; a critical assessment of the surface physics approach to heterogeneous catalysis.

  16. Residual thermal desorption studies of Ga adatoms on trenched Si(5 5 12) surface

    International Nuclear Information System (INIS)

    Kumar, Praveen; Kumar, Mahesh; Shivaprasad, S.M.

    2013-01-01

    We present here the thermal stability studies of the room temperature adsorbed Ga/Si(5 5 12) interfaces in the monolayer coverage regime, using AES and LEED as in-situ UHV characterization probes. Ga grows in Stranski–Krastanov growth mode at RT on the 2 × 1 reconstructed Si(5 5 12) surface where islands form on top of 2 ML of flat pseudomorphic Ga, yielding a (1 × 1) LEED pattern for coverages of 1.2 ML and above. When this RT adsorbed Ga/Si(5 5 12) interface is annealed at different temperatures, initially the strained Ga adlayers relax by agglomerating into 3D islands on top of a single Ga monolayer with an activation energy of 0.19 eV in the temperature range of 200–300 °C. The remnant Ga monolayer with a sharp (1 × 1) LEED pattern desorbs at temperature >400 °C, yielding the (1 1 2)–6 × 1 and 2 × (3 3 7) sub-monolayer superstructural. Finally at 720 °C Ga completely desorbs from the surface and leaves the clean 2 × 1 reconstructed Si(5 5 12) surface. The studies demonstrate the richness of the atomically trenched high index Si(5 5 12) surface, in obtaining several anisotropic features that can be used as templates to grow self-assembled nanostructures.

  17. Residual thermal desorption studies of Ga adatoms on trenched Si(5 5 12) surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Praveen [Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India); ISOM, Universidad Politecnia de Madrid, 28040 (Spain); Kumar, Mahesh [Physics and Energy Harvesting Group, National Physical Laboratory, New Delhi 110012 (India); Shivaprasad, S.M., E-mail: smsprasad@jncasr.ac.in [Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India)

    2013-10-01

    We present here the thermal stability studies of the room temperature adsorbed Ga/Si(5 5 12) interfaces in the monolayer coverage regime, using AES and LEED as in-situ UHV characterization probes. Ga grows in Stranski–Krastanov growth mode at RT on the 2 × 1 reconstructed Si(5 5 12) surface where islands form on top of 2 ML of flat pseudomorphic Ga, yielding a (1 × 1) LEED pattern for coverages of 1.2 ML and above. When this RT adsorbed Ga/Si(5 5 12) interface is annealed at different temperatures, initially the strained Ga adlayers relax by agglomerating into 3D islands on top of a single Ga monolayer with an activation energy of 0.19 eV in the temperature range of 200–300 °C. The remnant Ga monolayer with a sharp (1 × 1) LEED pattern desorbs at temperature >400 °C, yielding the (1 1 2)–6 × 1 and 2 × (3 3 7) sub-monolayer superstructural. Finally at 720 °C Ga completely desorbs from the surface and leaves the clean 2 × 1 reconstructed Si(5 5 12) surface. The studies demonstrate the richness of the atomically trenched high index Si(5 5 12) surface, in obtaining several anisotropic features that can be used as templates to grow self-assembled nanostructures.

  18. Environmental Assessment Methodologies for Commercial Buildings: An Elicitation Study of U.S. Building Professionals’ Beliefs on Leadership in Energy and Environmental Design (LEED

    Directory of Open Access Journals (Sweden)

    Jasmin Kientzel

    2011-12-01

    Full Text Available Voluntary environmental programs (VEPs have become increasingly popular around the world to address energy efficiency issues that mandatory building codes have not been able to tackle. Even though the utility of voluntary schemes is widely debated, they have become a de facto reality for many professionals in the building and construction sector. One topic that is neglected, however, in both academic and policy discussions, relates to how professionals (architects, engineers, real estate developers, etc. perceive the rise of voluntary rating schemes. In order to fill this gap in the literature, the present study investigates beliefs underlying adoption behavior regarding one of the most prominent voluntary assessment and certification programs in the U.S. building industry, the Leadership in Energy and Environmental Design (LEED scheme. In this paper, an elicitation study, based on 14 semi-structured interviews with building professionals in the North East of the United States, was conducted to analyze this question. Building on the Reasoned Action Approach, this paper shows that, in addition to more conventional factors such as financial calculations and marketing aspects, the understanding of beliefs held by building professionals offers important insights into their decisions to work with Voluntary Environmental Assessment and Rating Programs.

  19. Cross-cultural Adaptation and Linguistic Validation of the Korean Version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale

    Science.gov (United States)

    Park, Cholhee; Lee, Youn-Woo; Yoon, Duck Mi; Kim, Do Wan; Nam, Da Jeong

    2015-01-01

    Distinction between neuropathic pain and nociceptive pain helps facilitate appropriate management of pain; however, diagnosis of neuropathic pain remains a challenge. The aim of this study was to develop a Korean version of the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale and assess its reliability and validity. The translation and cross-cultural adaptation of the original LANSS pain scale into Korean was established according to the published guidelines. The Korean version of the LANSS pain scale was applied to a total of 213 patients who were expertly diagnosed with neuropathic (n = 113) or nociceptive pain (n = 100). The Korean version of the scale had good reliability (Cronbach's α coefficient = 0.815, Guttman split-half coefficient = 0.800). The area under the receiver operating characteristic curve was 0.928 with a 95% confidence interval of 0.885-0.959 (P < 0.001), suggesting good discriminate value. With a cut-off score ≥ 12, sensitivity was 72.6%, specificity was 98.0%, and the positive and negative predictive values were 98% and 76%, respectively. The Korean version of the LANSS pain scale is a useful, reliable, and valid instrument for screening neuropathic pain from nociceptive pain. PMID:26339176

  20. Cross-Cultural Psychometric Assessment of the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Pain Scale in the Portuguese Population.

    Science.gov (United States)

    Barbosa, Margarida; Bennett, Michael I; Verissimo, Ramiro; Carvalho, Davide

    2014-09-01

    Chronic pain is a well-known phenomenon. The differential diagnosis between neuropathic and nociceptive pain syndromes is a challenge. Consequently, assessment instruments that can distinguish between these conditions in a standardized way are of the utmost importance. The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) is a screening tool developed to identify chronic neuropathic pain. The aim of this study was the Portuguese language translation, linguistic adaptation of the LANSS pain scale, its semantic validation, internal consistency, temporal stability, as well its validity and discriminative power. LANSS Portuguese version scale was applied to 165 consecutive patients attending the pain clinic: 103 fulfilled the clinical criteria for the diagnosis of pain of neuropathic origin and the remaining 62 fulfilled the criteria for nociceptive pain. The scale proved to be an internally consistent (Cronbach's alpha = 0.78) and reliable instrument with good test-retest stability (r = 0.7; P cross-cultural version is a reliable and valid instrument for the differentiation of this type of pain. Its usage is recommended. © 2013 World Institute of Pain.

  1. Lessons Learned From The 200 West Pump And Treatment Facility Construction Project At The US DOE Hanford Site - A Leadership For Energy And Environmental Design (LEED) Gold-Certified Facility

    International Nuclear Information System (INIS)

    Dorr, Kent A.; Ostrom, Michael J.; Freeman-Pollard, Jhivaun R.

    2012-01-01

    CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy's (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built in an accelerated manner with American Recovery and Reinvestment Act (ARRA) funds and has attained Leadership in Energy and Environmental Design (LEED) GOLD certification, which makes it the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award. There were many contractual, technical, configuration management, quality, safety, and LEED challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility. This paper will present the Project and LEED accomplishments, as well as Lessons Learned by CHPRC when additional ARRA funds were used to accelerate design, procurement, construction, and commissioning of the 200 West Groundwater Pump and Treatment (2W PandT) Facility to meet DOE's mission of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012

  2. Lessons Learned From The 200 West Pump And Treatment Facility Construction Project At The US DOE Hanford Site - A Leadership For Energy And Environmental Design (LEED) Gold-Certified Facility

    Energy Technology Data Exchange (ETDEWEB)

    Dorr, Kent A. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Ostrom, Michael J. [CH2M HILL Plateau Remediation Company, Richland, WA (United States); Freeman-Pollard, Jhivaun R. [CH2M HILL Plateau Remediation Company, Richland, WA (United States)

    2012-11-14

    CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy's (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built in an accelerated manner with American Recovery and Reinvestment Act (ARRA) funds and has attained Leadership in Energy and Environmental Design (LEED) GOLD certification, which makes it the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award. There were many contractual, technical, configuration management, quality, safety, and LEED challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility. This paper will present the Project and LEED accomplishments, as well as Lessons Learned by CHPRC when additional ARRA funds were used to accelerate design, procurement, construction, and commissioning of the 200 West Groundwater Pump and Treatment (2W P&T) Facility to meet DOE's mission of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012.

  3. Efficiency analysis in the application of indicators LEED-ND, the arid zone of the north of Mexico, case of study: Parajes del Sur, Ciudad Juarez, Chihuahua; Analisis de la eficiencia en la aplicacion de indicadores LEED-ND, en la zona arida del norte de Mexico, caso de estudio: parajes del sur, Ciudad Juarez, Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Pena Barrera, Leticia [Universidad Autonoma de Ciudad Juarez, Chihuahua (Mexico)

    2009-01-15

    This article presents the analysis realized to the urban design of a colony applying the indicators of The Leadership in Energy (LEED-ND). The advantages that represent as far as impact are established and also the limits are pointed out, evaluating their efficiency in the application of indicators to improve performance and energy saving. Based on the analysis applied to the colony under study, some right solutions in the urban design are obtained that should be established as a part of the in force standardization. Nevertheless, the follow up to this same company in other developments, reflects that the proposals are not determined as a strategy of self planning but only to fulfill the asked requirements, obtaining a result with smaller impact and as an index that allows offering residential alternatives in the city tending to the sustained development. [Spanish] Este articulo presenta el analisis realizado al diseno urbano de un fraccionamiento aplicando los indicadores de The Leadership in Energy (LEED-ND). Se establecen las ventajas que presenta en cuanto a impacto y tambien se senalan las limitantes, evaluando su eficiencia en la aplicacion de indicadores para mejorar desempeno y ahorro energetico. Con base en el analisis aplicado al fraccionamiento en estudio, se tienen algunas soluciones acertadas en el diseno urbano que debieran establecerse como parte de la normatividad vigente, sin embargo, el seguimiento a esta misma empresa en otros desarrollos, refleja que las propuestas no estan determinadas como una estrategia de planeacion propia sino unicamente para cumplir con los requerimientos solicitados, obteniendo un resultado con menor impacto y como indice que permitan ofrecer alternativas habitacionales en la ciudad tendientes al desarrollo sostenido.

  4. Surface structural determination of UO2(111) using MeV ions

    International Nuclear Information System (INIS)

    Thompson, K.A.; Ellis, W.P.; Taylor, T.N.; Valone, S.M.; Maggiore, C.J.

    1983-01-01

    The UO 2 (111) surface was studied using MeV ions incident along the and directions. In addition, this surface was well characterized by LEED and Auger analysis. A resonance at 3.05 MeV for 4 He elastic scattering from 16 O made it possible to study the surface peaks for uranium and oxygen simultaneously. By combining previous surface studies with detailed analysis of the surface peaks and rocking curves for this compound material, an outward relaxation of 0.19 A +- 0.01 A was determined for uranium

  5. The global existence problem in general relativity

    CERN Document Server

    Andersson, L

    2000-01-01

    We survey some known facts and open questions concerning the global properties of 3+1 dimensional space--times containing a compact Cauchy surface. We consider space--times with an $\\ell$--dimensional Lie algebra of space--like Killing fields. For each $\\ell \\leq 3$, we give some basic results and conjectures on global existence and cosmic censorship. For the case of the 3+1 dimensional Einstein equations without symmetries, a new small data global existence result is announced.

  6. Growth optimization and electronic structure of ultrathin CoO films on Ag(001): A LEED and photoemission study

    Science.gov (United States)

    Barman, Sukanta; Menon, Krishnakumar S. R.

    2018-04-01

    We present here a detailed growth optimization of CoO thin film on Ag(001) involving the effects of different growth parameters on the electronic structure. A well-ordered stoichiometric growth of 5 ML CoO film has been observed at 473 K substrate temperature and 1 × 10-6 mbar oxygen partial pressure. The growth at lower substrate temperature and oxygen partial pressure show non-stoichiometric impurity phases which have been investigated further to correlate the growth parameters with surface electronic structure. The coverage dependent valence band electronic structure of the films grown at optimized condition reveals the presence of interfacial states near the Fermi edge (EF) for lower film coverages. Presence of interfacial states in the stoichiometric films rules out their defect-induced origin. We argue that this is an intrinsic feature of transition metal monoxides like NiO, CoO, MnO in the low coverage regime.

  7. Electron spin polarization effects in low energy electron diffraction, ion neutralization and metastable atom deexcitation at solid surfaces. Progress report No. 4, 1 January-31 December 1984

    International Nuclear Information System (INIS)

    1984-01-01

    In the present contract year, a GaAs polarized electron source has been used to undertake a polarized LEED study of order-disorder transformations at Cu 3 Au (100) and (111) surfaces. A polarized LEED study of Cu (100) has also been initiated. A polarized MDS study of Ni(110) surface magnetism has been completed. Spin dependences in the Auger electron yield were observed that provide a measure of the surface magnetism and were used to probe the dependence of surface magnetism on temperature and adsorbate coverage. A similar study using a ferromagnetic glass is now underway. A Mott polarization analyzer, constructed to measure the ESP of the ejected electrons, is also being installed on the apparatus. Such measurements provide direct information concerning the dynamics of secondary electron ejection and the details of adsorbate-substrate bonding

  8. Validity and reliability of the Spanish-language version of the self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale.

    Science.gov (United States)

    López-de-Uralde-Villanueva, I; Gil-Martínez, A; Candelas-Fernández, P; de Andrés-Ares, J; Beltrán-Alacreu, H; La Touche, R

    2016-12-08

    The self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) scale is a tool designed to identify patients with pain with neuropathic features. To assess the validity and reliability of the Spanish-language version of the S-LANSS scale. Our study included a total of 182 patients with chronic pain to assess the convergent and discriminant validity of the S-LANSS; the sample was increased to 321 patients to evaluate construct validity and reliability. The validated Spanish-language version of the ID-Pain questionnaire was used as the criterion variable. All participants completed the ID-Pain, the S-LANSS, and the Numerical Rating Scale for pain. Discriminant validity was evaluated by analysing sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). Construct validity was assessed with factor analysis and by comparing the odds ratio of each S-LANSS item to the total score. Convergent validity and reliability were evaluated with Pearson's r and Cronbach's alpha, respectively. The optimal cut-off point for S-LANSS was ≥12 points (AUC=.89; sensitivity=88.7; specificity=76.6). Factor analysis yielded one factor; furthermore, all items contributed significantly to the positive total score on the S-LANSS (P<.05). The S-LANSS showed a significant correlation with ID-Pain (r=.734, α=.71). The Spanish-language version of the S-LANSS is valid and reliable for identifying patients with chronic pain with neuropathic features. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Development of the Japanese Version of the Leeds Assessment of the Neuropathic Symptoms and Signs Pain Scale: Diagnostic Utility in a Clinical Setting.

    Science.gov (United States)

    Isomura, Tatsuya; Sumitani, Masahiko; Matsudaira, Ko; Kawaguchi, Mika; Inoue, Reo; Hozumi, Jun; Tanaka, Takeyuki; Oshima, Hirofumi; Mori, Kanto; Taketomi, Shuji; Inui, Hiroshi; Tahara, Keitaro; Yamagami, Ryota; Hayakawa, Kazuhiro

    2017-07-01

    We aimed to assess the diagnostic utility of the linguistically validated Japanese version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale (LANSS-J) as a screening tool for neuropathic pain in the clinical setting. Patients with neuropathic pain or nociceptive pain who were 20 to 85 years of age were included. Sensitivity and specificity using the original cutoff value of 12 were assessed to evaluate the diagnostic utility of the LANSS-J. Sensitivity and specificity with possible cutoff values were calculated, along with area under the receiver operating characteristic curve. We then evaluated agreement regarding assessment of the LANSS-J by two investigators. We used the intraclass correlation coefficient (ICC) for the total score and Cohen's kappa coefficient for each item. Data for patients with neuropathic pain (n = 30) and those with nociceptive pain (n = 29) were analyzed. With a cutoff of 12, the sensitivity was 63.3% (19/30) and the specificity 93.1% (27/29). Sensitivity improved substantially with a cutoff of ≤ 11 (≥ 83.3%, 25/30). High specificity (93.1%, 27/29) was sustained with a cutoff of 9 to 12. The ICC for the total score was 0.85, indicating sufficient agreement. Kappa coefficients ranged from 0.68 to 0.84. The LANSS-J is a valid screening tool for detecting neuropathic pain. Our results suggest that employing the original cutoff value provides high specificity, although a lower cutoff value of 10 or 11 (with its high specificity maintained) may be more beneficial when pain attributed to neuropathic mechanisms is suspected in Japanese patients. © 2016 World Institute of Pain.

  10. Validation of the Malayalam version of Leeds assessment of neuropathic symptoms and signs pain scale in cancer patients in the Regional Cancer Centre, Thiruvananthapuram, Kerala, India

    Directory of Open Access Journals (Sweden)

    Shoukkathali Anzar

    2017-01-01

    Full Text Available Objective: The Self-administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS is a 7-item self-report scale developed to identify pain which is of predominantly neuropathic origin. The aim of this study was to develop a Malayalam version of the LANSS and to test its validity and reliability in chronic pain patients. Methodology: We enrolled 101 Malayalam-speaking chronic pain patients who visited the Division of Palliative Medicine, Regional Cancer Centre, Thiruvananthapuram, Kerala, India. The translated version of S- LANSS was constructed by standard means. Fifty-one neuropathic pain and fifty nociceptive pain patients were identified by an independent pain physician and were subjected to the new pain scale by a palliative care nurse who was blinded to the diagnosis. The “gold standard diagnosis” is what the physician makes after clinical examination. Its validation, sensitivity, specificity, and positive and negative predictive values were determined. Results: Fifty-one neuropathic pain and fifty nociceptive pain patients were subjected to the Malayalam version of S-LANSS pain scale for validity testing. The agreement by Cohen's Kappa 0.743, Chi-square test P < 0.001, sensitivity 89.58, specificity 84.91, positive predictive value 84.31, negative predictive value 90.00, accuracy by 87.13, and likelihood ratio 5.94. Conclusion: The Malayalam version of S-LANSS pain scale is a validated screening tool for identifying neuropathic pain in chronic pain patients in Malayalam-speaking regions.

  11. ELS-LEED-study of low-dimensional plasmons in DySi2 layers and nanowires

    International Nuclear Information System (INIS)

    Rugeramigabo, Eddy Patrick

    2007-01-01

    Low-dimensional dysprosium silicide metal systems grown on Si have been characterized by means of energy loss spectroscopy of low energy electron diffraction. The several silicide phases depending on the growth conditions have been observed. Moreover collective charge excitations were clearly detected and identified as low-dimensional plasmons which have a different dispersion compared to the well known bulk and surface plasmons. Dy-silicide has been grown on Si(111) by means of molecular beam epitaxy. Due to its small lattice mismatch (-0.3%) to Si(111), Dy-silicide grows in epitaxial high quality crystalline layers. In the submonolayer regime, many silicide phases coexist until the silicide coverage approaches 1ML, and shows the characteristic 1 x 1 diffraction pattern with the stoichiometry DySi 2 . With further increasing of the coverage, the silicide turns to the multilayer phase. The collective electronic excitations in the monolayer structure have been found to have a 2D-character. Accordingly the plasmon dispersion reaches zero in the long-wavelength limit (at vanishing wave number q) and shows a √(q) behaviour until it entered the domain of strong damping. When grown on Si (001) the Dy-silicide formed an array of parallel nanowires, in the direction normal to the dimer row direction and their length was limited by the crossing of another nanowire. A structure dependent energy loss was observed: the energy loss were only sufficiently intense when the 7 x 2 reconstruction has formed. An possibility of creating vast area with only parallel nanowires in one direction was performed on vicinal Si(001) with four degree miscut. At the same coverage where the 7 x 2 reconstruction occurs on flat Si(001), it was surprising that, besides the 7 x 2 periodicity, the diffraction pattern revealed a mixture of phases, with periodicities ranging from the 10 x 2 to that of the 7 x 2, which was observed as the limit of shifting reflex positions. We were able to confirm the

  12. HREEL study of c(53x9)rect-N structure on Ni(111) surface

    International Nuclear Information System (INIS)

    Papagno, M.; Pacile, D.; Giallombardo, C.; Cupolillo, A.; Papagno, L.

    2005-01-01

    In this work we have prepared and characterized by low energy electron diffraction (LEED) and high-resolution electron energy loss spectroscopy (HREELS) the Ni(111)-c(53x9)rect-N surface structure formed by saturating the Ni(111) surface with nitrogen atoms. This structure was obtained by the ion-gauge assisted N 2 exposure method. The loss spectra show features at 50 and 25meV assigned to the N-Ni vibration and to a phonon of the reconstructed surface, respectively. We also investigated the case in which the Ni(111) surface was covered with a low coverage of N atoms

  13. Structure investigation of organic molecules on Au(111) surfaces; Strukturuntersuchung organischer Molekuele auf Au(111)-Oberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kazempoor, Michel

    2009-02-02

    The present work covers two topics namely the coadsorption of formic acid and water on Au(111) and the structure of biphenylalkanthiole SAMs on Au(111) surfaces. The coadsorption of formic acid and water on Au(111) surfaces has been investigated by means of vibrational and photoelectron spectroscopy (HREELS, XPS). Formic acid adsorbs at 90 K molecularly with vibrational modes characteristic for flat lying zig-zag chains in the mono- and multilayer regime, like in solid formic acid. The structure of the flat lying formic acid chains was determined by low energy electron diffraction (LEED) as a (2r3 x r19) unit cell. Annealing results in a complete desorption at 190 K. Sequential adsorption of formic acid and water at 90 K shows no significant chemical interaction. Upon annealing the coadsorbed layer to 140 K a hydrogenbonded cyclic complex of formic acid with one water molecule could be identified using isotopically labelled adsorbates. Upon further annealing this complex decomposes leaving molecularly adsorbed formic acid on the surface at 160 K, accompanied by a proton exchange between formic acid and water. The influence of the alkane spacer chain length on the structure of biphenylalkanethiols on Au(111) surfaces was investigated as well. A systematic study was done on BPn-SAMs deposited from the gas phase. For every chain length a structure was found by LEED. Furthermore the influence of temperature on the structure was investigated in the range from room temperature up to about 400 K. To obviate influences from different preparation methods BP3 and BP4 was deposited from gas phase and from solution. No LEED spots were observed on BP4 SAMs deposited from solution. For BP3 an influence of the preparation could be excluded. For all BPn-SAMs a good agreement between LEED and STM data's was found. Nevertheless different unit cells were determined by LEED and STM consistent structures could be suggested considering the unit cell size given by LEED and the

  14. Do Bare Rocks Exist on the Moon?

    Science.gov (United States)

    Allen, Carlton; Bandfield, Joshua; Greenhagen, Benjamin; Hayne, Paul; Leader, Frank; Paige, David

    2017-01-01

    Astronaut surface observations and close-up images at the Apollo and Chang'e 1 landing sites confirm that at least some lunar rocks have no discernable dust cover. However, ALSEP (Apollo Lunar Surface Experiments Package) measurements as well as astronaut and LADEE (Lunar Atmosphere and Dust Environment Explorer) orbital observations and laboratory experiments possibly suggest that a fine fraction of dust is levitated and moves across and above the lunar surface. Over millions of years such dust might be expected to coat all exposed rock surfaces. This study uses thermal modeling, combined with Diviner (a Lunar Reconnaissance Orbiter experiment) orbital lunar eclipse temperature data, to further document the existence of bare rocks on the lunar surface.

  15. Wetting of the diamond surface

    International Nuclear Information System (INIS)

    Hansen, J.O.

    1987-01-01

    The surface conditions which lead to a wide variation in the wettability of diamond surfaces have been investigated using macroscopic surfaces to allow for the crystal anisotropy. A wetting balance method of calculating adhesion tension and hence contact angle has been used for diamonds having major faces near the [111] and [110] lattice planes. Three classes of behaviour have been identified. Surface analyses by Rutherford Backscattering of helium ions, X-ray Photoelectron Spectroscopy and Low Energy Electron Diffraction (LEED) have been used to define the role of the oxygen coverage of the surface in the transition I → O → H. Ferric ion has a hydrophilizing effect on the diamond surface, thought to be the consequence of attachment to the hydroxyl groups at the surface by a ligand mechanism. Other transition metal ions did not show this effect. The phenomenon of hydration of the surface, i.e. progressively more hydrophilic behaviour on prolonged exposure to liquid water, has been quantified. Imbibition or water penetration at microcracks are thought unlikely, and a water cluster build-up at hydrophilic sites is thought to be the best explanation. Dynamic studies indicate little dependence of the advancing contact angle on velocity for velocities up to 10 -4 m/s, and slight dependence of the receding contact angle. Hence advancing angles by this technique are similar to equilibrated contact angles found by optical techniques, but the receding angles are lower than found by other non-dynamic measurements

  16. Surface structure of Bi2Sr2CaCu2O(8+delta) high-temperature superconductors studied using low-energy electron diffraction

    Science.gov (United States)

    Lindberg, P. A. P.; Shen, Z.-X.; Wells, B. O.; Mitzi, D. B.; Lindau, I.

    1988-12-01

    The surface structure of Bi2Sr2CaCu2O(8+delta) has been studied using low-energy electron diffraction (LEED). Sharp diffraction spots indicative of a well-ordered surface are observed. The LEED patterns unequivocally show that this type of material preferentially cleaves along the a-b planes of the nearly tetragonal unit cell. A superstructure extending along one of the axes in the a-b plane (b) is found to have a periodicity of 27 + or - 0.5 A, in good agreement with earlier studies of the three-dimensional crystal structure. The superstructure at the surface is nonlocal in character and reflects the long-range superlattice of the bulk along the b axis. Intensity modulations of the diffraction spots oriented along the b axis are also reported and discussed in terms of the cell dimension of the unit cell along the b axis.

  17. Surface structure of Bi2Sr2CaCu2O/sub 8+//sub δ high-temperature superconductors studied using low-energy electron diffraction

    International Nuclear Information System (INIS)

    Lindberg, P.A.P.; Shen, Z.; Wells, B.O.; Mitzi, D.B.; Lindau, I.; Spicer, W.E.; Kapitulnik, A.

    1988-01-01

    The surface structure of Bi 2 Sr 2 CaCu 2 O/sub 8+//sub δ has been studied using low-energy electron diffraction (LEED). Sharp diffraction spots indicative of a well-ordered surface are observed. The LEED patterns unequivocally show that this type of material preferentially cleaves along the a-b planes of the nearly tetragonal unit cell. A superstructure extending along one of the axes in the a-b plane (b) is found to have a periodicity of 27 +- 0.5 A, in good agreement with earlier studies of the three-dimensional crystal structure. We conclude that the superstructure at the surface is nonlocal in character and reflects the long-range superlattice of the bulk along the b axis. Intensity modulations of the diffraction spots oriented along the b axis are also reported and discussed in terms of the cell dimension of the unit cell along the b axis

  18. Modern methods of studying surfaces and their application to glasses

    International Nuclear Information System (INIS)

    Rauschenbach, B.; Haehnert, M.

    1977-05-01

    In the works are demonstrated modern methods for study of solid surfaces and its use of glasses. Study of the interaction of ions, electrons and photons with the glass surface provides information about the composition of the surface and its structure on an atomic scale. A qualitative analysis of a surface can be made with the aid of the Auger electron spectroscopy (AES) and the electron spectroscopy for chemical analysis (ESCA) and with the ion scattering (ISS and RBS) and the secondary ion mass spectrometry (SIMS). The structure of a surface can be studied by means of ion scattering and low-energy electron diffraction (LEED) and the topography of a surface by means of scanning electron microscopy (SEM). The ellipsometry is generally confined to measuring the thickness of very thin layers. The application these methods to the glass surfaces is demonstrated on series of examples. (author)

  19. Optimized surface-slab excited-state muffin-tin potential and surface core level shifts

    International Nuclear Information System (INIS)

    Rundgren, J.

    2003-01-01

    An optimized muffin-tin (MT) potential for surface slabs with preassigned surface core-level shifts (SCLS's) is presented. By using the MT radii as adjustable parameters the model is able to conserve the definition of the SCLS with respect to the bulk and concurrently to generate a potential that is continuous at the MT radii. The model is conceived for elastic electron scattering in a surface slab with exchange-correlation interaction described by the local density approximation. The model employs two data bases for the self-energy of the signal electron (after Hedin and Lundqvist or Sernelius). The potential model is discussed in detail with two surface structures Be(101-bar0), for which SCLS's are available, and Cu(111)p(2x2)Cs, in which the close-packed radii of the atoms are extremely different. It is considered plausible that tensor LEED based on an optimized MT potential can be used for determining SCLS's

  20. Ontological Proofs of Existence and Non-Existence

    Czech Academy of Sciences Publication Activity Database

    Hájek, Petr

    2008-01-01

    Roč. 90, č. 2 (2008), s. 257-262 ISSN 0039-3215 R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : ontological proofs * existence * non-existence * Gödel * Caramuel Subject RIV: BA - General Mathematics

  1. Existence theory in optimal control

    International Nuclear Information System (INIS)

    Olech, C.

    1976-01-01

    This paper treats the existence problem in two main cases. One case is that of linear systems when existence is based on closedness or compactness of the reachable set and the other, non-linear case refers to a situation where for the existence of optimal solutions closedness of the set of admissible solutions is needed. Some results from convex analysis are included in the paper. (author)

  2. Summary of existing uncertainty methods

    International Nuclear Information System (INIS)

    Glaeser, Horst

    2013-01-01

    A summary of existing and most used uncertainty methods is presented, and the main features are compared. One of these methods is the order statistics method based on Wilks' formula. It is applied in safety research as well as in licensing. This method has been first proposed by GRS for use in deterministic safety analysis, and is now used by many organisations world-wide. Its advantage is that the number of potential uncertain input and output parameters is not limited to a small number. Such a limitation was necessary for the first demonstration of the Code Scaling Applicability Uncertainty Method (CSAU) by the United States Regulatory Commission (USNRC). They did not apply Wilks' formula in their statistical method propagating input uncertainties to obtain the uncertainty of a single output variable, like peak cladding temperature. A Phenomena Identification and Ranking Table (PIRT) was set up in order to limit the number of uncertain input parameters, and consequently, the number of calculations to be performed. Another purpose of such a PIRT process is to identify the most important physical phenomena which a computer code should be suitable to calculate. The validation of the code should be focused on the identified phenomena. Response surfaces are used in some applications replacing the computer code for performing a high number of calculations. The second well known uncertainty method is the Uncertainty Methodology Based on Accuracy Extrapolation (UMAE) and the follow-up method 'Code with the Capability of Internal Assessment of Uncertainty (CIAU)' developed by the University Pisa. Unlike the statistical approaches, the CIAU does compare experimental data with calculation results. It does not consider uncertain input parameters. Therefore, the CIAU is highly dependent on the experimental database. The accuracy gained from the comparison between experimental data and calculated results are extrapolated to obtain the uncertainty of the system code predictions

  3. Molecular surface science of heterogeneous catalysis. History and perspective

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH 3 synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures

  4. Molecular surface science of heterogeneous catalysis. History and perspective

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH/sub 3/ synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures. (DLC)

  5. Lessons Learned from the 200 West Pump and Treatment Facility Construction Project at the US DOE Hanford Site - A Leadership for Energy and Environmental Design (LEED) Gold-Certified Facility - 13113

    Energy Technology Data Exchange (ETDEWEB)

    Dorr, Kent A.; Freeman-Pollard, Jhivaun R.; Ostrom, Michael J. [CH2M HILL Plateau Remediation Company, P.O. Box 1600, MSIN R4-41, 99352 (United States)

    2013-07-01

    CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy's (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built to an accelerated schedule with American Recovery and Reinvestment Act (ARRA) funds. There were many contractual, technical, configuration management, quality, safety, and Leadership in Energy and Environmental Design (LEED) challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility to meet DOE's mission objective of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012. The project team's successful integration of the project's core values and green energy technology throughout design, procurement, construction, and start-up of this complex, first-of-its-kind Bio Process facility resulted in successful achievement of DOE's mission objective, as well as attainment of LEED GOLD certification (Figure 1), which makes this Bio Process facility the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award. (authors)

  6. Lessons Learned from the 200 West Pump and Treatment Facility Construction Project at the US DOE Hanford Site - A Leadership for Energy and Environmental Design (LEED) Gold-Certified Facility - 13113

    International Nuclear Information System (INIS)

    Dorr, Kent A.; Freeman-Pollard, Jhivaun R.; Ostrom, Michael J.

    2013-01-01

    CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy's (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built to an accelerated schedule with American Recovery and Reinvestment Act (ARRA) funds. There were many contractual, technical, configuration management, quality, safety, and Leadership in Energy and Environmental Design (LEED) challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility to meet DOE's mission objective of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012. The project team's successful integration of the project's core values and green energy technology throughout design, procurement, construction, and start-up of this complex, first-of-its-kind Bio Process facility resulted in successful achievement of DOE's mission objective, as well as attainment of LEED GOLD certification (Figure 1), which makes this Bio Process facility the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award. (authors)

  7. Lessons Learned from the 200 West Pump and Treatment Facility Construction Project at the US DOE Hanford Site - A Leadership for Energy and Environmental Design (LEED) Gold-Certified Facility

    Energy Technology Data Exchange (ETDEWEB)

    Dorr, Kent A.; Ostrom, Michael J.; Freeman-Pollard, Jhivaun R.

    2013-01-11

    CH2M Hill Plateau Remediation Company (CHPRC) designed, constructed, commissioned, and began operation of the largest groundwater pump and treatment facility in the U.S. Department of Energy’s (DOE) nationwide complex. This one-of-a-kind groundwater pump and treatment facility, located at the Hanford Nuclear Reservation Site (Hanford Site) in Washington State, was built to an accelerated schedule with American Recovery and Reinvestment Act (ARRA) funds. There were many contractual, technical, configuration management, quality, safety, and Leadership in Energy and Environmental Design (LEED) challenges associated with the design, procurement, construction, and commissioning of this $95 million, 52,000 ft groundwater pump and treatment facility to meet DOE’s mission objective of treating contaminated groundwater at the Hanford Site with a new facility by June 28, 2012. The project team’s successful integration of the project’s core values and green energy technology throughout design, procurement, construction, and start-up of this complex, first-of-its-kind Bio Process facility resulted in successful achievement of DOE’s mission objective, as well as attainment of LEED GOLD certification, which makes this Bio Process facility the first non-administrative building in the DOE Office of Environmental Management complex to earn such an award.

  8. Existing Steel Railway Bridges Evaluation

    Science.gov (United States)

    Vičan, Josef; Gocál, Jozef; Odrobiňák, Jaroslav; Koteš, Peter

    2016-12-01

    The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  9. Existing Steel Railway Bridges Evaluation

    Directory of Open Access Journals (Sweden)

    Vičan Josef

    2016-12-01

    Full Text Available The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  10. First principles calculations for the cleaved and annealed Ge(111) surfaces

    International Nuclear Information System (INIS)

    Takeuchi, N.; Tosatti, E.; Selloni, A.

    1992-11-01

    We use ab initio Molecular Dynamics to study the structural and electronic properties of cleaved and annealed Ge(111) surfaces. New features emerge for both structures. For the (2x1) it is found that even though the stable state has a π-bonded chain structure, there are two isomers with the tilt angle of the chain in opposite directions. For the c(2x8) we find an asymmetry in the surface unit cell, in agreement with LEED experiments that show weak quarter-order spots. This inequivalence also produces a splitting of the rest atom and adatom dangling bond, which explains recent STM experiments. (author). 15 refs, 3 figs

  11. Limitations of existing web services

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Limitations of existing web services. Uploading or downloading large data. Serving too many user from single source. Difficult to provide computer intensive job. Depend on internet and its bandwidth. Security of data in transition. Maintain confidentiality of data ...

  12. Performance of Existing Hydrogen Stations

    Energy Technology Data Exchange (ETDEWEB)

    Sprik, Samuel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Jennifer M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ainscough, Christopher D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Peters, Michael C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-01

    In this presentation, the National Renewable Energy Laboratory presented aggregated analysis results on the performance of existing hydrogen stations, including performance, operation, utilization, maintenance, safety, hydrogen quality, and cost. The U.S. Department of Energy funds technology validation work at NREL through its National Fuel Cell Technology Evaluation Center (NFCTEC).

  13. The surface physics work station: final design

    International Nuclear Information System (INIS)

    Landers, R.; Kleiman, G.G.; Castro, S.G.C. de; Douglas, R.A.; Nascente, P.A.P.

    1996-01-01

    Thanks to funding from FAPESP we will be installing in the beginning of 1997 a work station for electron spectroscopy designed for the study of clean solid surfaces and the modification of these surfaces by deposition in situ of ultra thin metallic films. The main analytical tool will be a high resolution hemispherical analyzer made by VSW-Omicrom (EA 125 HR) which is capable of better than 5 meV resolution and high transmission due to its five channeltron multi detection system. The system will also have a Rear View LEED Optics for single crystal studies. The system will be housed in a 16'' cylindrical chamber with mu metal magnetic shielding having two levels for analysis. The upper level will contain instruments for technique which do not require photons such as LEED and sample cleaning. The lower level will have the electron analyzer, conventional X-ray source (Al/Mg), electron gun for Auger, e-beam evaporators for thin film deposition and ports for the future addition of different detectors. We will have a manipulator with 5 degrees of freedom (thre translation and two rotational) and sample heating and LN cooling. Finally we will have a fast entry/preparation chamber. The pumping system will have a combination of turbomolecular and ion pumps for the main chamber and a turbo for the fast entr/prep chamber. The system will be used initially for the study of surface alloys by XPS and Photoelectron Diffraction but as soon as it is properly characterized it will be open for collaborations with other groups interested in using its capabilities. (author)

  14. Existing and new techniques in uranium exploration

    International Nuclear Information System (INIS)

    Bowie, S.H.U.; Cameron, J.

    1976-01-01

    The demands on uranium exploration over the next 25 years will be very great indeed and will call for every possible means of improvement in exploration capability. The first essential is to increase geological knowledge of the mode of occurrence of uranium ore deposits. The second is to improve existing exploration techniques and instrumentation while, at the same time, promoting research and development on new methods to discover uranium ore bodies on the earth's surface and at depth. The present symposium is an effort to increase co-operation and the exchange of information in the critical field of uranium exploration techniques and instrumentation. As an introduction to the symposium a brief review is presented, firstly of what can be considered as existing techniques and, secondly, of techniques which have not yet been used on an appreciable scale. Some fourteen techniques used over the last 30 years are identified and their appropriate application, advantages and limitations are briefly summarized and the possibilities of their further development considered. The aim of future research on new techniques, in addition to finding new ways and means of identifying surface deposits, should be mainly directed to devising methods and instrumentation capable of detecting buried ore bodies that do not give a gamma signal at the surface. To achieve this aim, two contributory factors are essential: adequate financial support for research and development and increased specialized training in uranium exploration and instrumentation design. The papers in this symposium describe developments in the existing techniques, proposals for future research and development and case histories of exploration programmes

  15. The EXIST Mission Concept Study

    Science.gov (United States)

    Fishman, Gerald J.; Grindlay, J.; Hong, J.

    2008-01-01

    EXIST is a mission designed to find and study black holes (BHs) over a wide range of environments and masses, including: 1) BHs accreting from binary companions or dense molecular clouds throughout our Galaxy and the Local Group, 2) supermassive black holes (SMBHs) lying dormant in galaxies that reveal their existence by disrupting passing stars, and 3) SMBHs that are hidden from our view at lower energies due to obscuration by the gas that they accrete. 4) the birth of stellar mass BHs which is accompanied by long cosmic gamma-ray bursts (GRBs) which are seen several times a day and may be associated with the earliest stars to form in the Universe. EXIST will provide an order of magnitude increase in sensitivity and angular resolution as well as greater spectral resolution and bandwidth compared with earlier hard X-ray survey telescopes. With an onboard optical-infra red (IR) telescope, EXIST will measure the spectra and redshifts of GRBs and their utility as cosmological probes of the highest z universe and epoch of reionization. The mission would retain its primary goal of being the Black Hole Finder Probe in the Beyond Einstein Program. However, the new design for EXIST proposed to be studied here represents a significant advance from its previous incarnation as presented to BEPAC. The mission is now less than half the total mass, would be launched on the smallest EELV available (Atlas V-401) for a Medium Class mission, and most importantly includes a two-telescope complement that is ideally suited for the study of both obscured and very distant BHs. EXIST retains its very wide field hard X-ray imaging High Energy Telescope (HET) as the primary instrument, now with improved angular and spectral resolution, and in a more compact payload that allows occasional rapid slews for immediate optical/IR imaging and spectra of GRBs and AGN as well as enhanced hard X-ray spectra and timing with pointed observations. The mission would conduct a 2 year full sky survey in

  16. The Greenhouse Effect Does Exist!

    OpenAIRE

    Ebel, Jochen

    2009-01-01

    In particular, without the greenhouse effect, essential features of the atmospheric temperature profile as a function of height cannot be described, i.e., the existence of the tropopause above which we see an almost isothermal temperature curve, whereas beneath it the temperature curve is nearly adiabatic. The relationship between the greenhouse effect and observed temperature curve is explained and the paper by Gerlich and Tscheuschner [arXiv:0707.1161] critically analyzed. Gerlich and Tsche...

  17. Europe - space for transcultural existence?

    OpenAIRE

    Tamcke, Martin; Janny, de Jong; Klein, Lars; Waal, Margriet

    2013-01-01

    Europe - Space for Transcultural Existence? is the first volume of the new series, Studies in Euroculture, published by Göttingen University Press. The series derives its name from the Erasmus Mundus Master of Excellence Euroculture: Europe in the Wider World, a two year programme offered by a consortium of eight European universities in collaboration with four partner universities outside Europe. This master highlights regional, national and supranational dimensions of the European democrati...

  18. Existence of undiscovered Uranian satellites

    International Nuclear Information System (INIS)

    Boice, D.C.

    1986-04-01

    Structure in the Uranian ring system as observed in recent occultations may contain indirect evidence for the existence of undiscovered satellites. Using the Alfven and Arrhenius (1975, 1976) scenario for the formation of planetary systems, the orbital radii of up to nine hypothetical satellites interior to Miranda are computed. These calculations should provide interesting comparisons when the results from the Voyager 2 encounter with Uranus are made public. 15 refs., 1 fig., 1 tab

  19. UNCITRAL: Changes to existing law

    OpenAIRE

    Andersson, Joakim

    2008-01-01

    The UNCITRAL Convention on Contracts for the International Carriage of Goods [wholly or partly] by Sea has an ambition of replacing current maritime regimes and expands the application of the Convention to include also multimodal transport. This thesis questions what changes to existing law, in certain areas, the new Convention will bring compared to the current regimes. In the initial part, the thesis provides for a brief background and history of international maritime regulations and focus...

  20. Existence Results for Incompressible Magnetoelasticity

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Stefanelli, U.; Zeman, J.

    2015-01-01

    Roč. 35, č. 6 (2015), s. 2615-2623 ISSN 1078-0947 R&D Projects: GA ČR GA13-18652S Institutional support: RVO:67985556 Keywords : magnetoelasticity * magnetostrictive solids * incompressibility * existence of minimizers * quasistatic evolution * energetic solution Subject RIV: BA - General Mathematics Impact factor: 1.127, year: 2015 http://library.utia.cas.cz/separaty/2015/MTR/kruzik-0443017.pdf

  1. [Inelastic electron scattering from surfaces

    International Nuclear Information System (INIS)

    1993-01-01

    This program is aimed at the quantitative study of surface dynamical processes (vibrational, magnetic excitations) in crystalline slabs, ultrathin-layered materials, and chemisorbed systems on substrates, and of the geometric structure connected to these dynamical excitations. High-resolution electron-energy loss spectroscopy (HREELS) is a powerful probe. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50-300 eV). The analyses has been used to study surfaces of ordered alloys (NiAl). Ab-initio surface lattice dynamical results were combined with phonon-loss cross sections to achieve a more accurate microscopic description. First-principles phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross-section calculations. The combined microscopic approach was used to analyze EELS data of Cu(0001) and Ag(001) at two points. Positron diffraction is discussed as a structural and imaging tool. The relation between geometric structure of a film and its local magnetic properties will be studied in the future, along with other things

  2. Quantum logics with existence property

    International Nuclear Information System (INIS)

    Schindler, C.

    1991-01-01

    A quantum logic (σ-orthocomplete orthomodular poset L with a convex, unital, and separating set Δ of states) is said to have the existence property if the expectation functionals on lin(Δ) associated with the bounded observables of L form a vector space. Classical quantum logics as well as the Hilbert space logics of traditional quantum mechanics have this property. The author shows that, if a quantum logic satisfies certain conditions in addition to having property E, then the number of its blocks (maximal classical subsystems) must either be one (classical logics) or uncountable (as in Hilbert space logics)

  3. Does cold nuclear fusion exist?

    International Nuclear Information System (INIS)

    Brudanin, V.B.; Bystritskij, V.M.; Egorov, V.G.; Shamsutdinov, S.G.; Shyshkin, A.L.; Stolupin, V.A.; Yutlandov, I.A.

    1989-01-01

    The results of investigation of cold nuclear fusion on palladium are given both for electrolysis of heavy water D 2 O and mixture D 2 O + H 2 O) (1:1) and for palladium saturation with gaseous deuterium. The possibility of existance of this phenomenon was examined by detection of neutrons and gamma quanta from reactions: d + d → 3 He + n + 3.27 MeV, p + d → 3 He + γ + 5.5 MeV. Besides these reactions were identified by measuring the characteristic X radiation of palladium due to effect of charged products 3 He, p, t. The upper limits of the intensities of hypothetical sources of neutrons and gamma quanta at the 95% confidence level were obtained to be Q n ≤ 2x10 -2 n/sxcm 3 Pd, Q γ ≤ 2x10 -3 γ/sxcm 3 Pd. 2 refs.; 4 figs.; 2 tabs

  4. Straightening: existence, uniqueness and stability

    Science.gov (United States)

    Destrade, M.; Ogden, R. W.; Sgura, I.; Vergori, L.

    2014-01-01

    One of the least studied universal deformations of incompressible nonlinear elasticity, namely the straightening of a sector of a circular cylinder into a rectangular block, is revisited here and, in particular, issues of existence and stability are addressed. Particular attention is paid to the system of forces required to sustain the large static deformation, including by the application of end couples. The influence of geometric parameters and constitutive models on the appearance of wrinkles on the compressed face of the block is also studied. Different numerical methods for solving the incremental stability problem are compared and it is found that the impedance matrix method, based on the resolution of a matrix Riccati differential equation, is the more precise. PMID:24711723

  5. Why do interstellar grains exist

    International Nuclear Information System (INIS)

    Seab, C.G.; Hollenbach, D.J.; Mckee, C.F.; Tielens, A.G.G.M.

    1986-01-01

    There exists a discrepancy between calculated destruction rates of grains in the interstellar medium and postulated sources of new grains. This problem was examined by modelling the global life cycle of grains in the galaxy. The model includes: grain destruction due to supernovae shock waves; grain injection from cool stars, planetary nebulae, star formation, novae, and supernovae; grain growth by accretion in dark clouds; and a mixing scheme between phases of the interstellar medium. Grain growth in molecular clouds is considered as a mechanism or increasing the formation rate. To decrease the shock destruction rate, several new physical processes, such as partial vaporization effects in grain-grain collisions, breakdown of the small Larmor radius approximation for betatron acceleration, and relaxation of the steady-state shock assumption are included

  6. Growth and structure of titanium dioxide on the transition metal surfaces Re(10-10) and Ru(0001); Wachstum und Struktur von Titandioxid auf den Uebergangsmetalloberflaechen Re(10-10) und Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, D.

    2007-03-15

    In this work, we studied the growth and structure of titanium dioxide films on two morphologically different transition metal surfaces, namely the trench-like rhenium(10-10) and the hexagonal ruthenium(0001). The following methods were used: X-ray photoelectron and Auger-electron spectroscopy (XPS and AES), low energy electron diffraction (LEED), low energy Helium-ion scattering (LEIS), scanning tunneling microscopy (STM) and X-ray diffraction (XRD). Titanium dioxide films on rhenium(10-10) were synthesized by co-adsorption of titanium vapor in an oxygen atmosphere up to a thickness of 500 Aa and investigated by means of LEED, LEIS, XPS and XRD. In order to calibrate the titanium flux, the growth mode of titanium on the Re(10-10) surface was determined by means of LEIS, XPS and LEED. The growth of titanium dioxide on the hexagonal ruthenium(0001) surface was investigated by means of STM, XPS and AES. Due to the alloying affinity of Ti and Ru, a titanium oxide film pre-grown at low temperature was finally/fully oxidized at elevated temperature and pressure. First experiments concerning the growth of gold on these titanium dioxide films are presented. One important result of the ongoing work is the imaging of gold clusters with 2-5 atoms in the troughs of rutile(110) beside the typically observed clusters with 3 nm diameter by STM. (orig.)

  7. Diamond surface: atomic and electronic structure

    International Nuclear Information System (INIS)

    Pate, B.B.

    1984-01-01

    Experimental studies of the diamond surface (with primary emphasis on the (111) surface) are presented. Aspects of the diamond surface which are addressed include (1) the electronic structure, (2) the atomic structure, and (3) the effect of termination of the lattice by foreign atoms. Limited studies of graphite are discussed for comparison with the diamond results. Experimental results from valence band and core level photoemission spectroscopy (PES), Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectroscopy (both the total electron yield (TEY) and Auger electron yield (AEY) techniques) are used to study and characterize both the clean and hydrogenated surface. In addition, the interaction of hydrogen with the diamond surface is examined using results from vibrational high resolution low energy electron loss spectroscopy (in collaboration with Waclawski, Pierce, Swanson, and Celotta at the National Bureau of Standards) and photon stimulated ion desorption (PSID) yield at photon energies near the carbon k-edge (hv greater than or equal to 280 eV). Both EELS and PSID verify that the mechanically polished 1 x 1 surface is hydrogen terminated and also that the reconstructed surface is hydrogen free. The (111) 2 x 2/2 x 1 reconstructed surface is obtained from the hydrogenated (111) 1 x 1:H surface by annealing to approx. = 1000 0 C. We observe occupied intrinsic surface states and a surface chemical shift (0.95 +- 0.1 eV) to lower binding energy of the carbon 1s level on the hydrogen-free reconstructed surface. Atomic hydrogen is found to be reactive with the reconstructed surface, while molecular hydrogen is relatively inert. Exposure of the reconstructed surface to atomic hydrogen results in chemisorption of hydrogen and removal of the intrinsic surface state emission in and near the band gap region

  8. Existe sujeito em Michel Maffesoli?

    Directory of Open Access Journals (Sweden)

    Marli Appel da Silva

    2010-06-01

    Full Text Available Este ensaio discute a concepção de sujeito na abordagem teórica de Michel Maffesoli. As ideias desse autor estão em voga em alguns meios acadêmicos no Brasil e são difundidas por algumas mídias de grande circulação nacional. Entretanto, ao longo de suas obras, os pressupostos que definem quem é o sujeito maffesoliano se encontram pouco clarificados. Portanto, para alcançar o objetivo a que se propõe, este ensaio desenvolve uma análise da epistemologia e da ontologia maffesoliana com a finalidade de compreender as origens dos pressupostos desse autor, ou seja, as teorias e os autores em que Maffesoli se baseou para desenvolver uma visão de sujeito. Com essa compreensão, pretende-se responder à questão: existe sujeito na abordagem teórica de Maffesoli.

  9. Surface Chirality of Gly-Pro Dipeptide Adsorbed on a Cu(110) Surface.

    Science.gov (United States)

    Cruguel, Hervé; Méthivier, Christophe; Pradier, Claire-Marie; Humblot, Vincent

    2015-07-01

    The adsorption of chiral Gly-Pro dipeptide on Cu(110) has been characterized by combining in situ polarization modulation infrared reflection absorption spectroscopy (PM-RAIRS) and X-ray photoelectron spectroscopy (XPS). The chemical state of the dipeptide, and its anchoring points and adsorption geometry, were determined at various coverage values. Gly-Pro molecules are present on Cu(110) in their anionic form (NH2 /COO(-)) and adsorb under a 3-point binding via both oxygen atoms of the carboxylate group and via the nitrogen atom of the amine group. Low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM) have shown the presence of an extended 2D chiral array, sustained via intermolecular H-bonds interactions. Furthermore, due to the particular shape of the molecule, only one homochiral domain is formed, creating thus a truly chiral surface. © 2015 Wiley Periodicals, Inc.

  10. Structure and composition of chemically prepared and vacuum annealed InSb(0 0 1) surfaces

    International Nuclear Information System (INIS)

    Tereshchenko, O.E.

    2006-01-01

    The InSb(0 0 1) surfaces chemically treated in HCl-isopropanol solution and annealed in vacuum were studied by means of X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and electron energy-loss spectroscopy (EELS). The HCl-isopropanol treatment removes indium and antimony oxides and leaves on the surface about 3 ML of physisorbed overlayer, containing indium chlorides and small amounts of antimony, which can be thermally desorbed at 230 deg. C. The residual carbon contaminations were around 0.2-0.4 ML and consisted of the hydrocarbon molecules. These hydrocarbon contaminations were removed from the surface together with the indium chlorides and antimony overlayer. With increased annealing temperature, a sequence of reconstructions were identified by LEED: (1 x 1), (1 x 3), (4 x 3), and (4 x 1)/c(8 x 2), in the order of decreasing Sb/In ratio. The structural properties of chemically prepared InSb(0 0 1) surface were found to be similar to those obtained by decapping of Sb-capped epitaxial layers

  11. Surface buckling of black phosphorus: Determination, origin, and influence on electronic structure

    Science.gov (United States)

    Dai, Zhongwei; Jin, Wencan; Yu, Jie-Xiang; Grady, Maxwell; Sadowski, Jerzy T.; Kim, Young Duck; Hone, James; Dadap, Jerry I.; Zang, Jiadong; Osgood, Richard M.; Pohl, Karsten

    2017-12-01

    The surface structure of black phosphorus materials is determined using surface-sensitive dynamical microspot low energy electron diffraction (μ LEED ) analysis using a high spatial resolution low energy electron microscopy (LEEM) system. Samples of (i) crystalline cleaved black phosphorus (BP) at 300 K and (ii) exfoliated few-layer phosphorene (FLP) of about 10 nm thickness which were annealed at 573 K in vacuum were studied. In both samples, a significant surface buckling of 0.22 Å and 0.30 Å, respectively, is measured, which is one order of magnitude larger than previously reported. As direct evidence for large buckling, we observe a set of (for the flat surface forbidden) diffraction spots. Using first-principles calculations, we find that the presence of surface vacancies is responsible for the surface buckling in both BP and FLP, and is related to the intrinsic hole doping of phosphoresce materials previously reported.

  12. In-situ oxidation study of Pd(100) by surface x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Volkan; Franz, Dirk; Stierle, Andreas [AG Grenzflaechen, Universitaet Siegen (Germany); Martin, Natalia; Lundgren, Edvin [Department of Synchrotron Radiation Research, Lund University (Sweden); Mantilla, Miguel [MPI fuer Metallforschung, Stuttgart (Germany)

    2011-07-01

    The oxidation of the Pd(100) surface at oxygen pressures in the 10{sup -6} mbar to 10{sup 3} mbar range and temperatures up to 1000 K has been studied in-situ by surface x-ray diffraction (SXRD). The SXRD experiments were performed at the MPI beamline at the Angstrom Quelle Karlsruhe (ANKA). We present the surface and crystal truncation rod (CTR) data from the ({radical}(5) x {radical}(5)) surface layer. We show that the transformation from the surface oxide to PdO bulk oxide can be observed in-situ under specific pressure and temperature conditions. We compare our results with previously proposed structure models based on low energy electron diffraction (LEED) I(V) curves and density functional theory calculations. Finally, we elucidate the question of commensurability of the surface oxide layer with respect to the Pd(100) substrate.

  13. Major Successes of Theory-and-Experiment-Combined Studies in Surface Chemistry and Heterogeneous Catalysis.

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, Gabor A.; Li, Yimin

    2009-11-21

    Experimental discoveries followed by theoretical interpretations that pave the way of further advances by experimentalists is a developing pattern in modern surface chemistry and catalysis. The revolution of modern surface science started with the development of surface-sensitive techniques such as LEED, XPS, AES, ISS and SIMS, in which the close collaboration between experimentalists and theorists led to the quantitative determination of surface structure and composition. The experimental discovery of the chemical activity of surface defects and the trends in the reactivity of transitional metals followed by the explanations from the theoretical studies led to the molecular level understanding of active sites in catalysis. The molecular level knowledge, in turn, provided a guide for experiments to search for new generation of catalysts. These and many other examples of successes in experiment-and-theory-combined studies demonstrate the importance of the collaboration between experimentalists and theorists in the development of modern surface science.

  14. LDEF data: Comparisons with existing models

    Science.gov (United States)

    Coombs, Cassandra R.; Watts, Alan J.; Wagner, John D.; Atkinson, Dale R.

    1993-04-01

    The relationship between the observed cratering impact damage on the Long Duration Exposure Facility (LDEF) versus the existing models for both the natural environment of micrometeoroids and the man-made debris was investigated. Experimental data was provided by several LDEF Principal Investigators, Meteoroid and Debris Special Investigation Group (M&D SIG) members, and by the Kennedy Space Center Analysis Team (KSC A-Team) members. These data were collected from various aluminum materials around the LDEF satellite. A PC (personal computer) computer program, SPENV, was written which incorporates the existing models of the Low Earth Orbit (LEO) environment. This program calculates the expected number of impacts per unit area as functions of altitude, orbital inclination, time in orbit, and direction of the spacecraft surface relative to the velocity vector, for both micrometeoroids and man-made debris. Since both particle models are couched in terms of impact fluxes versus impactor particle size, and much of the LDEF data is in the form of crater production rates, scaling laws have been used to relate the two. Also many hydrodynamic impact computer simulations were conducted, using CTH, of various impact events, that identified certain modes of response, including simple metallic target cratering, perforations and delamination effects of coatings.

  15. ENERGY STAR and Green Buildings--Using ENERGY STAR Resources for Green Building Rating Systems: LEED[R], Green Globes[R] and CHPS

    Science.gov (United States)

    Utebay, Kudret

    2011-01-01

    Every building, from the smallest school to the tallest skyscraper, uses energy. This energy is most often generated by burning fossil fuels, which releases greenhouse gases into the atmosphere and contributes to climate change. Existing commercial buildings offer a significant opportunity for low-cost, immediate emissions and energy cost…

  16. Teaching organisational change management for sustainability : designing and delivering a course at the University of Leeds to better prepare future sustainability change agents

    NARCIS (Netherlands)

    Lozano, Rodrigo; Ceulemans, Kim; Scarff Seatter, Carol

    2015-01-01

    A number of universities worldwide have created new courses and degrees or modified existing ones, as a response to the increasing interest by companies to hire sustainability literate graduates. However, many of such courses have been developed with a focus on 'hard' technocentric or managerial

  17. Analysis of surface bond lengths reported for chemisorption on metal surfaces

    Science.gov (United States)

    Mitchell, K. A. R.

    1985-01-01

    A review is given of bond length information available from the techniques of surface crystallography (particularly with LEED, SEXAFS and photoelectron diffraction) for chemisorption on well-defined surfaces of metals (M). For adsorbed main-group atoms (X), measured X-M interatomic distances for 38 combinations of X and M have been assessed with a bond order-bond length relation in combination with the Schomaker-Stevenson approach for determining single-bond lengths. When the surface bond orders are fixed primarily by the valency of X, this approach appears to provide a simple framework for predicing X-M surface bond lengths. Further, in cases where agreement has been reached from different surface crystallographic techniques, this framework has the potential for assessing refinements to the surface bonding model (e.g. in determining the roles of the effective surface valency of M, and of coordinate bonding and supplementary π bonding between X and M). Preliminary comparisons of structural data are also given for molecular adsorption (CO and ethylidyne) and for the chemisorption of other metal atoms.

  18. Surface science study of selective ethylene epoxidation catalyzed by the Ag(110) surface: Structural sensitivity

    International Nuclear Information System (INIS)

    Campbell, C.T.

    1984-01-01

    The selective oxidation of ethylene to ethylene epoxide (C 2 H 4 +1/2O 2 →C 2 H 4 O) over Ag is the simplest example of kinetically controlled, selective heterogeneous catalysis. We have studied the steady-state kinetics and selectivity of this reaction for the first time on a clean, well-characterized Ag(110) surface by using a special apparatus which allows rapid (approx.20 s) transfer between a high-pressure catalytic microreactor and an ultrahigh vacuum surface analysis (AES, XPS, LEED, TDS) chamber. The effects of temperature and reactant pressures upon the rate and selectivity are virtually identical on Ag(110) and supported, high surface area Ag catalysts. The absolute specific rate (per Ag surface atom) is, however, some 100-fold higher for Ag(110) than for high surface area catalysts. This is related to the well-known structural sensitivity of this reaction. It is postulated that a small percentage of (110) planes (or [110]-like sites) are responsible for most of the catalytic activity of high surface area catalysts. The high activity of the (110) plane is attributed to its high sticking probability for dissociative oxygen adsorption, since the rate of ethylene epoxidation is shown in a related work [Ref. 1: C. T. Campbell and M. T. Paffett, Surf. Sci. (in press)] to be proportional to the coverage of atomically adsorbed oxygen at constant temperature and ethylene pressure

  19. 10 CFR 4.127 - Existing facilities.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Existing facilities. 4.127 Section 4.127 Energy NUCLEAR... 1973, as Amended Discriminatory Practices § 4.127 Existing facilities. (a) Accessibility. A recipient... make each of its existing facilities or every part of an existing facility accessible to and usable by...

  20. Ultrahigh vacuum and high-pressure coadsorption of CO and H2 on Pd(111): A combined SFG, TDS, and LEED study

    Science.gov (United States)

    Morkel, Matthias; Rupprechter, Günther; Freund, Hans-Joachim

    2003-11-01

    Sum frequency generation (SFG) vibrational spectroscopy was carried out in conjunction with thermal desorption spectroscopy, low-energy electron diffraction, and Auger electron spectroscopy to examine the coadsorption of CO and H2 on Pd(111). Sequential dosing as well as various CO/H2 mixtures was utilized to study intermolecular interactions between CO and H2. Preadsorbed CO effectively prevented the dissociative adsorption of hydrogen for CO coverages ⩾0.33 ML. While preadsorbed hydrogen was able to hinder CO adsorption at low temperature (100 K), hydrogen was replaced from the surface by CO at 150 K. When 1:1 mixtures of CO/H2 were used at 100 K, hydrogen selectively hindered CO adsorption on on-top sites, while above ˜125 K no blocking of CO adsorption was observed. The observations are explained in terms of mutual site blocking, of a CO-H phase separation, and of a CO-assisted hydrogen dissolution in the Pd bulk. The temperature-dependent site blocking effect of hydrogen is attributed to the ability (inability) of surface hydrogen to diffuse into the Pd bulk above (below) ˜125 K. Nonlinear optical SFG spectroscopy allowed us to study these effects not only in ultrahigh vacuum but also in a high-pressure environment. Using an SFG-compatible ultrahigh vacuum-high-pressure cell, spectra of 1:10 CO/H2 mixtures were acquired up to 55 mbar and 550 K, with simultaneous gas chromatographic and mass spectrometric gas phase analysis. Under reaction conditions, CO coverages ⩾0.5 ML were observed which strongly limit H2 adsorption and thus may be partly responsible for the low CO hydrogenation rate. The high-pressure and high-temperature SFG spectra also showed indications of a reversible surface roughening or a highly dynamic (not perfectly ordered) CO adsorbate phase. Implications of the observed adsorbate structures on catalytic CO hydrogenation on supported Pd nanoparticles are discussed.

  1. Ultrahigh vacuum and high-pressure coadsorption of CO and H2 on Pd(111): A combined SFG, TDS, and LEED study

    International Nuclear Information System (INIS)

    Morkel, Matthias; Rupprechter, Guenther; Freund, Hans-Joachim

    2003-01-01

    Sum frequency generation (SFG) vibrational spectroscopy was carried out in conjunction with thermal desorption spectroscopy, low-energy electron diffraction, and Auger electron spectroscopy to examine the coadsorption of CO and H 2 on Pd(111). Sequential dosing as well as various CO/H 2 mixtures was utilized to study intermolecular interactions between CO and H 2 . Preadsorbed CO effectively prevented the dissociative adsorption of hydrogen for CO coverages ≥0.33 ML. While preadsorbed hydrogen was able to hinder CO adsorption at low temperature (100 K), hydrogen was replaced from the surface by CO at 150 K. When 1:1 mixtures of CO/H 2 were used at 100 K, hydrogen selectively hindered CO adsorption on on-top sites, while above ∼125 K no blocking of CO adsorption was observed. The observations are explained in terms of mutual site blocking, of a CO-H phase separation, and of a CO-assisted hydrogen dissolution in the Pd bulk. The temperature-dependent site blocking effect of hydrogen is attributed to the ability (inability) of surface hydrogen to diffuse into the Pd bulk above (below) ∼125 K. Nonlinear optical SFG spectroscopy allowed us to study these effects not only in ultrahigh vacuum but also in a high-pressure environment. Using an SFG-compatible ultrahigh vacuum-high-pressure cell, spectra of 1:10 CO/H 2 mixtures were acquired up to 55 mbar and 550 K, with simultaneous gas chromatographic and mass spectrometric gas phase analysis. Under reaction conditions, CO coverages ≥0.5 ML were observed which strongly limit H 2 adsorption and thus may be partly responsible for the low CO hydrogenation rate. The high-pressure and high-temperature SFG spectra also showed indications of a reversible surface roughening or a highly dynamic (not perfectly ordered) CO adsorbate phase. Implications of the observed adsorbate structures on catalytic CO hydrogenation on supported Pd nanoparticles are discussed

  2. Surface structural reconstruction of SrVO3 thin films on SrTiO3 (001)

    Science.gov (United States)

    Wang, Gaomin; Saghayezhian, Mohammad; Chen, Lina; Guo, Hangwen; Zhang, Jiandi

    Paramagnetic metallic oxide SrVO3>(SVO) is an itinerant system known to undergo thickness-induced metal-insulator-transition (MIT) in ultrathin film form, which makes it a prototype system for the study of the mechanism behind metal-insulator-transition like structure distortion, electron correlations and disorder-induced localization. We have grown SrVO3 thin film with atomically flat surface through the layer-by-layer deposition by laser Molecular Beam Epitaxy (laser-MBE) on SrTiO3 (001) surface. Low Energy Electron Diffraction (LEED) measurements reveal that there is a (√2X √2) R45°surface reconstruction independent of film thickness. By using LEED-I(V) structure refinement, we determine the surface structure. In combination with X-ray Photoelectron Spectroscopy (XPS) and Scanning Tunneling Microscopy (STM), we discuss the implication on the MIT in ultrathin films below 2-3 unit cell thickness. This work is supported by the National Science Foundation under the NSF EPSCoR Cooperative Agreement No. EPS-1003897 with additional support from the Louisiana Board of Regents.

  3. Normal emission photoelectron diffraction: a new technique for determining surface structure

    International Nuclear Information System (INIS)

    Kevan, S.D.

    1980-05-01

    One technique, photoelectron diffraction (PhD) is characterized. It has some promise in surmounting some of the problems of LEED. In PhD, the differential (angle-resolved) photoemission cross-section of a core level localized on an adsorbate atom is measured as a function of some final state parameter. The photoemission final state consists of two components, one of which propagates directly to the detector and another which scatters off the surface and then propagates to the detector. These are added coherently, and interference between the two manifests itself as cross-section oscillations which are sensitive to the local structure around the absorbing atom. We have shown that PhD deals effectively with two- and probably also three-dimensionally disordered systems. Its non-damaging and localized, atom-specific nature gives PhD a good deal of promise in dealing with molecular overlayer systems. It is concluded that while PhD will never replace LEED, it may provide useful, complementary and possibly also more accurate surface structural information

  4. 76 FR 9376 - Proposed Extension of Existing Information Collection;

    Science.gov (United States)

    2011-02-17

    ... Extension of Existing Information Collection; Refuse Piles and Impoundment Structures, Recordkeeping and... surface installations. More specifically, these sections address refuse piles (30 CFR 77.215), and... combination of materials; and refuse piles are deposits of coal mine waste (other than overburden or spoil...

  5. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M., E-mail: m.walker@warwick.ac.uk; Tedder, M.S.; Palmer, J.D.; Mudd, J.J.; McConville, C.F.

    2016-08-30

    Highlights: • Preparation of a clean, well-ordered Ge(100) surface with atomic hydrogen. • Surface oxide layers removed by AHC at room temperature, but not hydrocarbons. • Increasing surface temperature during AHC dramatically improves efficiency. • AHC with the surface heated to 250 °C led to a near complete removal of contaminants. • (2 × 1) LEED pattern from IBA and AHC indicates asymmetric dimer reconstruction. - Abstract: Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet

  6. Pseudomorphic growth mode of Pb on the Al{sub 13}Fe{sub 4}(0 1 0) approximant surface

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, J., E-mail: Julian.ledieu@univ-lorraine.fr [Institut Jean Lamour (UMR 7198 CNRS-Université de Lorraine), Parc de Saurupt, CS50840, 54011 Nancy Cedex (France); Weerd, M.-C de [Institut Jean Lamour (UMR 7198 CNRS-Université de Lorraine), Parc de Saurupt, CS50840, 54011 Nancy Cedex (France); Hahne, M.; Gille, P. [Department of Earth and Environmental Sciences, Crystallography Section, Ludwig-Maximilians-Universität München, Theresienstr. 41, D-80333 München (Germany); Fournée, V. [Institut Jean Lamour (UMR 7198 CNRS-Université de Lorraine), Parc de Saurupt, CS50840, 54011 Nancy Cedex (France)

    2015-11-30

    Highlights: • Pb adsorption has been characterised on the Al{sub 13}Fe{sub 4}(0 1 0) approximant surface. • A pseudomorphic Pb monolayer is formed at 300 K on this highly corrugated template. • The Pb atomic arrangement replicates the motifs observed on the clean surface. • The formation of surface alloys and intermixing can be disregarded. • Efficient energy dissipation of impinging adatoms allows additional layer deposition. - Abstract: We report the adsorption of lead adatoms on the pseudo-10-fold Al{sub 13}Fe{sub 4}(0 1 0) surface using low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). For the submonolayer regime, Pb adatoms remain highly mobile across the surface at 300 K. STM analysis indicates the formation of irregularly shaped islands of monoatomic height. The latter do not coalesce with increasing coverage. At 0.95 MLE coverage, the LEED patterns are consistent with a pseudomorphic growth of the adatoms. This is confirmed by STM measurements which reveal local motifs qualitatively similar to those observed on the clean Al{sub 13}Fe{sub 4}(0 1 0) surface, i.e. prior to dosing. Apart from the absence of plasmons, the XPS measurements of Pb 4f and Al 2s core levels are comparable to those observed for the Pb/Al(1 1 1) system.

  7. Do Elementary Particles Have an Objective Existence?

    OpenAIRE

    Nissenson, Bilha

    2007-01-01

    The formulation of quantum theory does not comply with the notion of objective existence of elementary particles. Objective existence independent of observation implies the distinguishability of elementary particles. In other words: If elementary particles have an objective existence independent of observations, then they are distinguishable. Or if elementary particles are indistinguishable then matter cannot have existence independent of our observation. This paper presents a simple deductio...

  8. 34 CFR 104.22 - Existing facilities.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Existing facilities. 104.22 Section 104.22 Education... Accessibility § 104.22 Existing facilities. (a) Accessibility. A recipient shall operate its program or activity.... This paragraph does not require a recipient to make each of its existing facilities or every part of a...

  9. 45 CFR 1170.32 - Existing facilities.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Existing facilities. 1170.32 Section 1170.32... ASSISTED PROGRAMS OR ACTIVITIES Accessibility § 1170.32 Existing facilities. (a) Accessibility. A recipient... require a recipient to make each of its existing facilities or every part of a facility accessible to and...

  10. 45 CFR 605.22 - Existing facilities.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Existing facilities. 605.22 Section 605.22 Public... Accessibility § 605.22 Existing facilities. (a) Accessibility. A recipient shall operate each program or... existing facilities or every part of a facility accessible to and usable by qualified handicapped persons...

  11. 14 CFR 1251.301 - Existing facilities.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Existing facilities. 1251.301 Section 1251... HANDICAP Accessibility § 1251.301 Existing facilities. (a) Accessibility. A recipient shall operate each... existing facilities or every part of a facility accessible to and usable by handicapped persons. (b...

  12. 45 CFR 1151.22 - Existing facilities.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Existing facilities. 1151.22 Section 1151.22... Prohibited Accessibility § 1151.22 Existing facilities. (a) A recipient shall operate each program or... make each of its existing facilities or every part of a facility accessible to and usable by...

  13. 10 CFR 611.206 - Existing facilities.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Existing facilities. 611.206 Section 611.206 Energy... PROGRAM Facility/Funding Awards § 611.206 Existing facilities. The Secretary shall, in making awards to those manufacturers that have existing facilities, give priority to those facilities that are oldest or...

  14. Surface Preparation of InAs (110 Using Atomic Hydrogen

    Directory of Open Access Journals (Sweden)

    T.D. Veal

    2002-06-01

    Full Text Available Atomic hydrogen cleaning has been used to produce structurally and electronically damage-free InAs(110 surfaces.  X-ray photoelectron spectroscopy (XPS was used to obtain chemical composition and chemical state information about the surface, before and after the removal of the atmospheric contamination. Low energy electron diffraction (LEED and high-resolution electron-energy-loss spectroscopy (HREELS were also used, respectively, to determine the surface reconstruction and degree of surface ordering, and to probe the adsorbed contaminant vibrational modes and the collective excitations of the clean surface. Clean, ordered and stoichiometric  InAs(110-(1×1 surfaces were obtained by exposure to thermally generated atomic hydrogen at a substrate temperature as low as 400ºC.  Semi-classical dielectric theory analysis of HREEL spectra of the phonon and plasmon excitations of the clean surface indicate that no electronic damage or dopant passivation were induced by the surface preparation method.

  15. In-situ observation of oxidation of Ti(0001) surface by real-time photoelectron spectroscopy using synchrotron radiation

    CERN Document Server

    Takakuwa, Y; Yoshigoe, A; Teraoka, Y; Mizuno, Y; Tonda, H; Homma, T

    2003-01-01

    Temperature dependence of the initial oxidation kinetics of Ti(0001) surface was investigated by low energy electron diffraction (LEED) and real-time photoelectron spectroscopy using synchrotron radiation of surface- and bulk-sensitive photon energies. LEED observation revealed that oxide layers grow epitaxially with different surface structures depending on temperature: 1x1 at 200degC and sq root 3 x sq root 3 at 400degC. From the oxygen uptake curve measured by O 1s photo-electron intensity, it was clarified that oxygen diffusion through the epitaxially grown oxide layer is significantly enhanced with raising temperature, making the oxide layer thicker than 70A at 400degC. The chemical shift components observed for Ti 2p showed that TiO sub 2 becomes predominant at the subsurface with O sub 2 dose, while the stoichiometry of oxide near the interface is maintained as TiO and Ti sub 2 O sub 3 , for both cases at 200degC and 400degC. Thus it is concluded that the epitaxial growth of a very thin oxide on the Ti...

  16. The Si(100)-Sb 2x1 and Ge(100) 2x1 surfaces: A multi-technique study

    International Nuclear Information System (INIS)

    Richter, M.

    1993-08-01

    The electronic and geometric structures of the clean and Sb terminated Si(100)2x1 and Ge(100)-2x1 surfaces have been investigated using a multi-technique approach. Low energy electron diffraction (LEED), scanning tunneling microscopy (STM), surface extended X-ray absorption fine structure (SEXAFS) spectroscopy and angle-integrated core-level photoemission electron spectroscopy (PES) were employed to measure the surface symmetry, defect structure, relevant bond lengths, atomic coordination and electronic structure. By employing a multi-technique approach, it is possible to correlate changes in the geometric structure to specific features of the core-level lineshape of the substrate. This allows for the assignment of components of the core-level lineshape to be assigned to specific surface and near-surface atoms

  17. Catalysis studies

    International Nuclear Information System (INIS)

    Taylor, T.N.; Ellis, W.P.

    1977-11-01

    The New Research Initiatives Program (NRIP) project on catalysis in Los Alamos Scientific Laboratory (LASL) Group CMB-8 has made significant progress towards performing the first basic in situ experimental studies of heterogeneous catalysis on solid compound surfaces in a LEED-Auger system. To further understand the surface crystallography of a possible catalyst compound, LEED-Auger measurements were made on UO 2 (approximately 100) vicinal surfaces. These (approximately 100) vicinal surfaces were shown to decompose irreversibly into lower index facets, including prominent (100) facets, at temperatures below those needed for creation of lowest index faceting on (approximately 111) vicinal surfaces. LEED examination of fully faceted surfaces from both types of UO 2 vicinal cuts did not show evidence of cyclopropane or propene chemisorption. The existing LEED-Auger system was modified to allow catalytic reactions at approximately less than 10 -3 torr. A sample holder, specifically designed for catalysis measurements in the modified system, was tested while examining single crystals of CoO and Cr 2 O 3 . Extensive LEED-Auger measurements were made on CoO in vacuo and in the presence of light hydrocarbons and alcohols plus H 2 O, NO, and NH 3 . No chemisorptive behavior was observed except with H 2 O in the presence of the electron beam. Although only examined briefly, the Cr 2 O 3 was remarkable for the sharp LEED features obtained prior to any surface treatment in the vacuum system

  18. Existence of equilibria in articulated bearings

    Science.gov (United States)

    Buscaglia, G.; Ciuperca, I.; Hafidi, I.; Jai, M.

    2007-04-01

    The existence of equilibrium solutions for a lubricated system consisting of an articulated body sliding over a flat plate is considered. Though this configuration is very common (it corresponds to the popular tilting-pad thrust bearings), the existence problem has only been addressed in extremely simplified cases, such as planar sliders of infinite width. Our results show the existence of at least one equilibrium for a quite general class of (nonplanar) slider shapes. We also extend previous results concerning planar sliders.

  19. Alloy formation and chemisorption at Zn/Pt(111) bimetallic surfaces using alkali ISS, XPD, and TPD.

    Science.gov (United States)

    Ho, Chih-Sung; Martono, Eddie; Banerjee, Santanu; Roszell, John; Vohs, John; Koel, Bruce E

    2013-11-21

    Alloy formation and chemisorption at bimetallic surfaces formed by vapor-depositing Zn on a Pt(111) single crystal were investigated primarily by using X-ray photoelectron diffraction (XPD), X-ray photoelectron spectroscopy (XPS), low-energy alkali ion scattering spectroscopy (ALISS), low electron energy diffraction (LEED), and temperature programmed desorption (TPD). A wide range of conditions were investigated to explore whether deposition and annealing of Zn films could produce well-defined, ordered alloy surfaces, similar to those encountered for Sn/Pt(111) surface alloys. These attempts were unsuccessful, although weak, diffuse (2 × 2) spots were observed under special conditions. The particular PtZn bimetallic alloy created by annealing one monolayer of Zn on Pt(111) at 600 K, which has a Zn composition in the surface layer of about 5 at. %, was investigated in detail by using XPD and ALISS. Only a diffuse (1 × 1) pattern was observed from this surface by LEED, suggesting that no long-range, ordered alloy structure was formed. Zn atoms were substitutionally incorporated into the Pt(111) crystal to form a near-surface alloy in which Zn atoms were found to reside primarily in the topmost and second layers. The alloyed Zn atoms in the topmost layer are coplanar with the Pt atoms in the surface layer, without any "buckling" of Zn, that is, displacement in the vertical direction. This result is expected because of the similar size of Pt and Zn, based on previous studies of bimetallic Pt alloys. Zn atoms desorb upon heating rather than diffusing deep into the bulk of the Pt crystal. Temperature programmed desorption (TPD) measurements show that both CO and NO have lower desorption energies on the PtZn alloy surface compared to that on the clean Pt(111) surface.

  20. 47 CFR 17.17 - Existing structures.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Existing structures. 17.17 Section 17.17... STRUCTURES Federal Aviation Administration Notification Criteria § 17.17 Existing structures. (a) The requirements found in § 17.23 relating to painting and lighting of antenna structures shall not apply to those...

  1. 10 CFR 1040.72 - Existing facilities.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Existing facilities. 1040.72 Section 1040.72 Energy... § 1040.72 Existing facilities. (a) Accessibility. A recipient shall operate any program or activity to... facilities or every part of a facility accessible to and useable by handicapped persons. (b) Methods. A...

  2. 45 CFR 84.22 - Existing facilities.

    Science.gov (United States)

    2010-10-01

    ... HANDICAP IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 84.22 Existing facilities. (a) Accessibility. A recipient shall operate its program or activity so that when each part is..., welfare, or other social services at alternate accessible sites, alteration of existing facilities and...

  3. Financial gap calculations for existing cogeneration 2008

    International Nuclear Information System (INIS)

    Hers, S.J.; Wetzels, W.; Seebregts, A.J.; Van der Welle, A.J.

    2008-05-01

    The Dutch SDE (abbreviation for the renewable energy incentive) subsidy scheme promotes the reduction of CO2 emissions which results from the use of Combined Heat and Power (CHP) plants. This report calculates the profitability of operation of existing CHP plants. This information can be used for decision making on the SDE subsidy for existing CHP plants in 2008 [nl

  4. On the existence of consistent price systems

    DEFF Research Database (Denmark)

    Bayraktar, Erhan; Pakkanen, Mikko S.; Sayit, Hasanjan

    2014-01-01

    We formulate a sufficient condition for the existence of a consistent price system (CPS), which is weaker than the conditional full support condition (CFS). We use the new condition to show the existence of CPSs for certain processes that fail to have the CFS property. In particular this condition...

  5. Open algebraic surfaces

    CERN Document Server

    Miyanishi, Masayoshi

    2000-01-01

    Open algebraic surfaces are a synonym for algebraic surfaces that are not necessarily complete. An open algebraic surface is understood as a Zariski open set of a projective algebraic surface. There is a long history of research on projective algebraic surfaces, and there exists a beautiful Enriques-Kodaira classification of such surfaces. The research accumulated by Ramanujan, Abhyankar, Moh, and Nagata and others has established a classification theory of open algebraic surfaces comparable to the Enriques-Kodaira theory. This research provides powerful methods to study the geometry and topology of open algebraic surfaces. The theory of open algebraic surfaces is applicable not only to algebraic geometry, but also to other fields, such as commutative algebra, invariant theory, and singularities. This book contains a comprehensive account of the theory of open algebraic surfaces, as well as several applications, in particular to the study of affine surfaces. Prerequisite to understanding the text is a basic b...

  6. The existence of trajectories joining critical points

    International Nuclear Information System (INIS)

    Yu Shuxiang.

    1985-01-01

    In this paper, using the notion of an isolating block and the concept of canonical regions, three existence criteria of trajectories connecting a pair of critical points of planar differential equations are given. (author)

  7. Pre-Existing Condition Insurance Plan Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Affordable Care Act created the new Pre-Existing Condition Insurance Plan (PCIP) program to make health insurance available to Americans denied coverage by...

  8. Seismic assessment of existing nuclear chemical plants

    International Nuclear Information System (INIS)

    Merriman, P.A.

    1997-01-01

    This paper outlines the generic approach to the seismic assessment of existing structures. It describes the role of the safety case in determining the studies carried out by the functional departments on individual projects. There is an emphasis on the role of existing information and material tests to provide realistic properties for analysis to account for possible degradation effects. Finally, a case study of a concrete containment cell is shown to illustrate the approach. (author)

  9. Solar Panel Installations on Existing Structures

    OpenAIRE

    Tim D. Sass; Pe; Leed

    2013-01-01

    The rising price of fossil fuels, government incentives and growing public aware-ness for the need to implement sustainable energy supplies has resulted in a large in-crease in solar panel installations across the country. For many sites the most eco-nomical solar panel installation uses existing, southerly facing rooftops. Adding solar panels to an existing roof typically means increased loads that must be borne by the building-s structural elements. The structural desig...

  10. Surface Water & Surface Drainage

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

  11. Existence test for asynchronous interval iterations

    DEFF Research Database (Denmark)

    Madsen, Kaj; Caprani, O.; Stauning, Ole

    1997-01-01

    In the search for regions that contain fixed points ofa real function of several variables, tests based on interval calculationscan be used to establish existence ornon-existence of fixed points in regions that are examined in the course ofthe search. The search can e.g. be performed...... as a synchronous (sequential) interval iteration:In each iteration step all components of the iterate are calculatedbased on the previous iterate. In this case it is straight forward to base simple interval existence and non-existencetests on the calculations done in each step of the iteration. The search can also...... on thecomponentwise calculations done in the course of the iteration. These componentwisetests are useful for parallel implementation of the search, sincethe tests can then be performed local to each processor and only when a test issuccessful do a processor communicate this result to other processors....

  12. Seismic reevaluation of existing nuclear power plants

    International Nuclear Information System (INIS)

    Hennart, J.C.

    1978-01-01

    The codes and regulations governing Nuclear Power Plant seismic analysis are continuously becoming more stringent. In addition, design ground accelerations of existing plants must sometimes be increased as a result of discovery of faulting zones or recording of recent earthquakes near the plant location after plant design. These new factors can result in augmented seismic design criteria. Seismic reanalysius of the existing Nuclear Power Plant structures and equipments is necessary to prevent the consequences of newly postulated accidents that could cause undue risk to the health or safety of the public. This paper reviews the developments of seismic analysis as applied to Nuclear Power Plants and the methods used by Westinghouse to requalify existing plants to the most recent safety requirements. (author)

  13. The Existence of Public Protection Unit

    Directory of Open Access Journals (Sweden)

    Moh. Ilham A. Hamudy

    2014-12-01

    Full Text Available This article is about the Public Protection Unit (Satlinmas formerly known as civil defence (Hansip. This article is a summary of the results of the desk study and fieldwork conducted in October-November 2013 in the town of Magelang and Surabaya. This study used descriptive qualitative approach to explore the combined role and existence Satlinmas. The results of the study showed, the existence of the problem Satlinmas still leave many, including, first, the legal basis for the establishment of Satlinmas. Until now, there has been no new regulations governing Satlinmas. Existing regulations are too weak and cannot capture the times. Second, the formulation of concepts and basic tasks and functions Satlinmas overlap with other institutions. Third, Satlinmas image in society tend to fade and abused. Fourth, Satlinmas incorporation into the Municipal Police deemed not appropriate, because different philosophy.

  14. Extremal surface barriers

    International Nuclear Information System (INIS)

    Engelhardt, Netta; Wall, Aron C.

    2014-01-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

  15. Radiation protection programme for existing exposure situation

    International Nuclear Information System (INIS)

    Ramadhani, Hilali Hussein

    2016-04-01

    This study was conducted to develop the Radiation protection Programme (RPP) to ensure that measures are in place for protection of individuals from the existing source of exposure. The study established a number of protective and remedial actions to be considered by the responsible regulatory Authority, licensee for existing exposure in workplace and dwellings. Tanzania is endowed with a number NORMs processing industries with an experience of uncontrolled exploration and extraction of minerals and the use of unsafe mining methods leading to severe environmental damage and appalling living conditions in the mining communities. Some of NORMs industries have been abandoned due to lack of an effect management infrastructure. The residual radioactive materials have been found to be the most import source of existing exposure resulted from NORMs industries. The Radon gas and its progeny have also been found to be a source of existing exposure from natural source as well as the major source of risk and health effects associated with existing exposure situation. The following measures have been discovered to play a pivotal role in avoiding or reducing the source of exposure to individuals such as restriction of the use of the construction materials, restriction on the consumption of foodstuffs and restriction on the access to the land and buildings, the removal of the magnitude of the source in terms of activity concentration as well as improvement of ventilation in dwellings. Therefore, the regulatory body (Tanzania Atomic Energy Commission) should examine the major areas outlined in the established RRP for existing exposure situation resulted from the NORMs industries and natural sources so as to develop strategies that will ensure the adequate protection of members of the public and the environment as well as guiding operating organizations to develop radiation protection and safety measures for workers. (au)

  16. Foucault, Counselling and the Aesthetics of Existence

    Science.gov (United States)

    Peters, Michael A.

    2005-01-01

    Michel Foucault was drawn late in life to study the "arts of the self" in Greco-Roman culture as a basis, following Nietzsche, for what he called an "aesthetics of existence." By this, he meant a set of creative and experimental processes and techniques by which an individual turns him- or herself into a work of art. For Nietzsche, it was above…

  17. How to prove the existence of metabolons?

    DEFF Research Database (Denmark)

    Bassard, Jean-Étienne André; Halkier, Barbara Ann

    2017-01-01

    Sequential enzymes in biosynthetic pathways are organized in metabolons. It is challenging to provide experimental evidence for the existence of metabolons as biosynthetic pathways are composed of highly dynamic protein–protein interactions. Many different methods are being applied, each with str...

  18. Conditions for the Existence of Market Equilibrium.

    Science.gov (United States)

    Bryant, William D. A.

    1997-01-01

    Maintains that most graduate-level economics textbooks rarely mention the need for consumers to be above their minimum wealth position as a condition for market equilibrium. Argues that this omission leaves students with a mistaken sense about the range of circumstances under which market equilibria can exist. (MJP)

  19. 22 CFR 142.16 - Existing facilities.

    Science.gov (United States)

    2010-04-01

    ... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 142.16 Existing facilities. (a) Accessibility. A recipient shall operate each program or activity to which this part applies so that when each...., telecommunication device for the deaf) redesign of equipment, reassignment of classes or other services to...

  20. Transportation capabilities of the existing cask fleet

    International Nuclear Information System (INIS)

    Johnson, P.E.; Joy, D.S.; Wankerl, M.W.

    1991-01-01

    This paper describes a number of scenarios estimating the amount of spent nuclear fuel that could be transported to a Monitored Retrievable Storage (MRS) Facility by various combinations of existing cask fleets. To develop the scenarios, the data provided by the Transportation System Data Base (TSDB) were modified to reflect the additional time for cask turnaround resulting from various startup and transportation issues. With these more realistic speed and cask-handling assumptions, the annual transportation capability of a fleet consisting of all of the existing casks is approximately 46 metric tons of uranium (MTU). The most likely fleet of existing casks that would be made available to the Department of Energy (DOE) consists of two rail, three overweight truck, and six legal weight truck casks. Under the same transportation assumptions, this cask fleet is capable of approximately transporting 270 MTU/year. These ranges of capability is a result of the assumptions pertaining to the number of casks assumed to be available. It should be noted that this assessment assumes additional casks based on existing certifications are not fabricated. 5 refs., 4 tabs

  1. Conservation and Development Options existing on Uluguru ...

    African Journals Online (AJOL)

    Effective management of projects on Uluguru Mountains requires that both development and conservation options are weighed and that opportunities and challenges are considered. This study identified various conservation and development options existing on Uluguru Mountains and assessed the perceptions of the local ...

  2. Transportation capabilities of the existing cask fleet

    International Nuclear Information System (INIS)

    Johnson, P.E.; Wankerl, M.W.; Joy, D.S.

    1991-01-01

    This paper describes a number of scenarios estimating the amount of spent nuclear fuel that could be transported to a Monitored Retrievable Storage (MRS) Facility by various combinations of existing cask fleets. To develop the scenarios, the data provided by the Transportation System Data Base (TSDB) were modified to reflect the additional time for cask turnaround resulting from various startup and transportation issues. With these more realistic speed and cask-handling assumptions, the annual transportation capability of a fleet consisting of all of the existing casks is approximately 465 metric tons of uranium (MTU). The most likely fleet of existing casks that would be made available to the DOE consists of two rail, three overweight truck, and six legal weight truck casks. Under the same transportation assumptions, this cask fleet is capable of approximately transporting 270 MTU/year. These ranges of capability is a result of the assumptions pertaining to the number of casks assumed to be available. It should be noted that this assessment assumes additional casks based on existing certifications are not fabricated

  3. Does the Kuleshov Effect really Exist?

    DEFF Research Database (Denmark)

    Barratt, Daniel; Cabak Rédei, Anna

    2013-01-01

    with a doll, a dead woman in a coffin, and a bowl of soup; the viewers of the three sequences were reported to have perceived Mozhukin’s face as expressing happiness, sadness, and hunger/thoughtfulness respectively. It is not clear, however, whether or not the socalled “Kuleshov effect” really exists...

  4. COMPARATIVE ANALYSIS OF SOME EXISTING KINETIC MODELS ...

    African Journals Online (AJOL)

    The biosorption of three heavy metal ions namely; Zn2+, Cu2+ and Mn2+ using five microorganisms namely; Bacillus circulans, Pseudomonas aeruginosa, Staphylococcus xylosus, Streptomyces rimosus and Yeast (Saccharomyces sp.) were studied. In this paper, the effectiveness of six existing and two proposed kinetic ...

  5. Do ‘African’ universities exist?

    DEFF Research Database (Denmark)

    Jensen, Stig; Adriansen, Hanne Kirstine; Madsen, Lene Møller

    2015-01-01

    This chapter provides a background for understanding the book. We outline some of the debates in which the individual chapters are situated and thereby show how the book contributes to and fills gaps in existing research. After providing a short history of African universities, the chapter subseq...

  6. Do Biopositive Effects of Ionizing Radiations Exist

    International Nuclear Information System (INIS)

    Broda, E.

    1983-01-01

    The claim that radiations, e.g, in spas, can have biopositive actions on humans is unproven and unplausible. It also conflicts with the contents of the standard handbooks and with national legislation everywhere. Further, stimulation of plants by radiation is badly reproducible. But even if existing it need not be beneficial to the plant itself ("selfpositive"). (author)

  7. Repurposing Existing Material for Performance Support.

    Science.gov (United States)

    Harvey, Francis A.; Nelson, Adam

    1995-01-01

    Presents an overview of performance support systems (PSS), describes their role in promoting productivity in agile organizations, and discusses issues related to developing effective performance support using existing orientation, training, or procedural manuals. Topics include strategic principles of agility, and adding value when incorporating…

  8. Global existence proof for relativistic Boltzmann equation

    International Nuclear Information System (INIS)

    Dudynski, M.; Ekiel-Jezewska, M.L.

    1992-01-01

    The existence and causality of solutions to the relativistic Boltzmann equation in L 1 and in L loc 1 are proved. The solutions are shown to satisfy physically natural a priori bounds, time-independent in L 1 . The results rely upon new techniques developed for the nonrelativistic Boltzmann equation by DiPerna and Lions

  9. 38 CFR 18.422 - Existing facilities.

    Science.gov (United States)

    2010-07-01

    ... THE CIVIL RIGHTS ACT OF 1964 Nondiscrimination on the Basis of Handicap Accessibility § 18.422 Existing facilities. (a) Accessibility. A recipient shall operate each program or activity to which this... visits, delivery of health, or other social services at alternate accessible sites, alteration of...

  10. Developing an Actuarial Track Utilizing Existing Resources

    Science.gov (United States)

    Rodgers, Kathy V.; Sarol, Yalçin

    2014-01-01

    Students earning a degree in mathematics often seek information on how to apply their mathematical knowledge. One option is to follow a curriculum with an actuarial emphasis designed to prepare students as an applied mathematician in the actuarial field. By developing only two new courses and utilizing existing courses for Validation by…

  11. 7 CFR 1718.52 - Existing mortgages.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Existing mortgages. 1718.52 Section 1718.52 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOAN SECURITY DOCUMENTS FOR ELECTRIC BORROWERS Mortgage for Distribution Borrowers § 1718.52...

  12. Transforming existing content into reusable Learning Objects

    NARCIS (Netherlands)

    Doorten, Monique; Giesbers, Bas; Janssen, José; Daniels, Jan; Koper, Rob

    2003-01-01

    Please cite as: Doorten, M., Giesbers, B., Janssen, J., Daniëls, J, & Koper, E.J.R., (2004). Transforming existing content into reusable learning objects. In R. McGreal, Online Education using Learning Objects (pp. 116-127). London: RoutledgeFalmer.

  13. Psychology's struggle for existence: Second edition, 1913.

    Science.gov (United States)

    Wundt, Wilhelm; Lamiell, James T

    2013-08-01

    Presents an English translation of Wilhelm Wundt's Psychology's struggle for existence: Second edition, 1913, by James T. Lamiell in August, 2012. In his essay, Wundt advised against the impending divorce of psychology from philosophy. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  14. Altering existing buildings in the UK

    International Nuclear Information System (INIS)

    Roberts, Simon

    2008-01-01

    The profiles of both existing housing and existing public and commercial buildings show that many have very poor thermal efficiency. The UK housing stock is replaced at a low rate of about 1% a year, so to cut energy use it is essential to address the challenges of existing buildings. This will involve reducing energy demand through passive measures such as retrofitted insulation, replacement of windows and proper airtightness, while ensuring adequate ventilation. Active measures include upgrading improved boilers and adding locally produced energy from wind, biomass, solar power and other sources. The introduction of Display Energy Certificates will increase energy awareness but there will also need to be a programme of increased demolition for the worst-performing homes. In addition, buildings will need to be adapted to cope with worse weather, higher temperatures and increased flood risk as climate change takes effect. Overheating, rather than excessive cold, is set to become a growing problem for householders and employees in existing UK buildings

  15. Adding Semantic Support to Existing UDDI Infrastructure

    National Research Council Canada - National Science Library

    Luo, Jim; Montrose, Bruce; Kang, Myong

    2005-01-01

    .... The advantage is that it is completely backward compatible. The add-on modules only need to be installed on the clients of users who wish to take advantage of semantic markups. They can be integrated seamlessly into existing systems and operations without any modification of the infrastructure.

  16. Dyakonov surface waves

    DEFF Research Database (Denmark)

    Takayama, Osamu; Crasovan, Lucian Cornel; Johansen, Steffen Kjær

    2008-01-01

    The interface of two semi-infinite media, where at least one of them is a birefringent crystal, supports a special type of surface wave that was predicted theoretically by D'yakonov in 1988. Since then, the properties of such waves, which exist in transparent media only under very special......, the existence of these surface waves in specific material examples is analyzed, discussing the challenge posed by their experimental observation....

  17. Essence and Existence in Avicenna and Averroes

    Directory of Open Access Journals (Sweden)

    Belo, Catarina

    2009-12-01

    Full Text Available This article explores the views on existence of medieval Muslim philosophers Avicenna (d. 1037 and Averroes (d. 1198, whose works followed closely the philosophy of Aristotle. In addition to the Aristotelian influence, which permeated all medieval Islamic philosophy, Avicenna and Averroes were also inspired by Islamic theology, known in Arabic as kalām. The distinction between essence and existence is one of the most central and controversial aspects of Avicenna’s philosophy, together with his claim that existence is an accident. Averroes in turn has a radically different conception of existence, identifying it with existing beings rather than considering it as something in itself. With the Latin translation of Avicenna’s metaphysical works in the 12th century, the Avicennian distinction went on to shape much of the debate on existence in medieval Scholastic philosophy and beyond. This article assesses the meaning of the distinction in Avicenna as well as Averroes’ criticism. In explicating their radically different views on existence, it also touches on later discussions concerning existence, for example the issue whether existence is a predicate, in the Modern Age.

    El presente artículo explora las percepciones sobre la existencia de los filósofos medievales musulmanes Avicena (m. 1037 y Averroes (m. 1198, cuyas obras se encuentran muy próximas a la filosofía de Aristóteles. Además de la influencia aristotélica, que caló en toda la filosofía islámica medieval, Avicena y Averroes estuvieron inspirados por la teología islámica, conocida en árabe como Kalām. La distinción entre esencia y existencia es uno de los más fundamentales y controvertidos aspectos de la filosofía de Avicena junto a su aseveración de que la existencia es un accidente. Averroes, en cambio, concibe de forma radicalmente diferente la existencia, identificándola con los seres existentes más que considerarla como algo en

  18. Overview of Existing Wind Energy Ordinances

    Energy Technology Data Exchange (ETDEWEB)

    Oteri, F.

    2008-12-01

    Due to increased energy demand in the United States, rural communities with limited or no experience with wind energy now have the opportunity to become involved in this industry. Communities with good wind resources may be approached by entities with plans to develop the resource. Although these opportunities can create new revenue in the form of construction jobs and land lease payments, they also create a new responsibility on the part of local governments to ensure that ordinances will be established to aid the development of safe facilities that will be embraced by the community. The purpose of this report is to educate and engage state and local governments, as well as policymakers, about existing large wind energy ordinances. These groups will have a collection of examples to utilize when they attempt to draft a new large wind energy ordinance in a town or county without existing ordinances.

  19. Co-existence in multispecies biofilm communities

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng

    of these emergent properties which are relevant to as diverse areas as clinical settings and natural systems. In this thesis, I have attempted to contribute to our knowledge on the multispecies interactions with a special focus on biofilm communities. I was especially interested in how co-existing species affect...... each other and in understanding the key mechanisms and interactions involved. In the introduction of this thesis the most important concepts of multi-species interactions and biofilm development are explained. After this the topic changes to the various ways of examining community interactions...... and production. The analysis was further extended in manuscript 3, in which the effect of social interac-tions on biofilm formation in multispecies co-cultures isolated from a diverse range of environments was examined. The question raised was whether the interspecific interactions of co-existing bacteria...

  20. Partial Cooperative Equilibria: Existence and Characterization

    Directory of Open Access Journals (Sweden)

    Amandine Ghintran

    2010-09-01

    Full Text Available We study the solution concepts of partial cooperative Cournot-Nash equilibria and partial cooperative Stackelberg equilibria. The partial cooperative Cournot-Nash equilibrium is axiomatically characterized by using notions of rationality, consistency and converse consistency with regard to reduced games. We also establish sufficient conditions for which partial cooperative Cournot-Nash equilibria and partial cooperative Stackelberg equilibria exist in supermodular games. Finally, we provide an application to strategic network formation where such solution concepts may be useful.

  1. Does evaporation paradox exist in China?

    Directory of Open Access Journals (Sweden)

    Z. T. Cong

    2009-03-01

    Full Text Available One expected consequence of global warming is the increase in evaporation. However, lots of observations show that the rate of evaporation from open pans of water has been steadily decreasing all over the world in the past 50 years. The contrast between expectation and observation is called "evaporation paradox". Based on data from 317 weather stations in China from 1956 to 2005, the trends of pan evaporation and air temperature were obtained and evaporation paradox was analyzed. The conclusions include: (1 From 1956 to 2005, pan evaporation paradox existed in China as a whole while pan evaporation kept decreasing and air temperature became warmer and warmer, but it does not apply to Northeast and Southeast China; (2 From 1956 to 1985, pan evaporation paradox existed narrowly as a whole with unobvious climate warming trend, but it does not apply to Northeast China; (3 From 1986 to 2005, in the past 20 years, pan evaporation paradox did not exist for the whole period while pan evaporation kept increasing, although it existed in South China. Furthermore, the trend of other weather factors including sunshine duration, windspeed, humidity and vapor pressure deficit, and their relations with pan evaporation are discussed. As a result, it can be concluded that pan evaporation decreasing is caused by the decreasing in radiation and wind speed before 1985 and pan evaporation increasing is caused by the decreasing in vapor pressure deficit due to strong warming after 1986. With the Budyko curve, it can be concluded that the actual evaporation decreased in the former 30 years and increased in the latter 20 year for the whole China.

  2. Existence and Comparability of data sources

    OpenAIRE

    KUHNIMHOF, T; ARMOOGUM, J

    2007-01-01

    The deliverable at hand comprises a comprehensive overview over existing data sources which can be used for analysis of long distance travel demand. This encompasses both national and international data sources with a focus on household travel surveys. Three types of relevant surveys were identified: - National travel surveys with focus on daily mobility - Travel survey elements dedicated to long distance mobility - Long distance travel surveys. RAPPORT DE CONTRAT

  3. Transgender Parenting: A Review of Existing Research

    OpenAIRE

    Stotzer, Rebecca L; Herman, Jody L; Hasenbush, Amira

    2014-01-01

    The authors of this report reviewed 51 studies that analyze data about transgender parents. This report reviews the existing research on the prevalence and characteristics of transgender people who are parents, the quality of relationships between transgender parents and their children, outcomes for children with a transgender parent, and the reported needs of transgender parents. Overall, the authors found that substantial numbers of transgender people are parents, though at rates below the ...

  4. Streamlining Research by Using Existing Tools

    OpenAIRE

    Greene, Sarah M.; Baldwin, Laura-Mae; Dolor, Rowena J.; Thompson, Ella; Neale, Anne Victoria

    2011-01-01

    Over the past two decades, the health research enterprise has matured rapidly, and many recognize an urgent need to translate pertinent research results into practice, to help improve the quality, accessibility, and affordability of U.S. health care. Streamlining research operations would speed translation, particularly for multi-site collaborations. However, the culture of research discourages reusing or adapting existing resources or study materials. Too often, researchers start studies and...

  5. Surface stress and large-scale self-organization at organic-metal interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pollinger, Florian

    2009-01-22

    The role of elastic interactions, particularly for the self-organized formation of periodically faceted interfaces, was investigated in this thesis for archetype organic-metal interfaces. The cantilever bending technique was applied to study the change of surface stress upon formation of the interface between 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) and Ag(111). The main focus of this work was on the investigation of the formation of the long-range ordered, self-organized faceted PTCDA/Ag(10 8 7) interface. Reciprocal space maps of this interface were recorded both by spot profile analysis low energy electron diffraction (SPA-LEED) and low energy electron microscopy (LEEM) in selected area LEED mode. Complementary to the reciprocal data, also microscopic real-space LEEM data were used to characterize the morphology of this interface. Six different facet faces ((111), (532), (743), (954), (13 9 5), and (542)) were observed for the preparation path of molecular adsorption on the substrate kept at 550 K. Facet-sensitive dark-field LEEM localized these facets to grow in homogeneous areas of microscopic extensions. The temperature-dependence of the interface formation was studied in a range between 418 K and 612 K in order to learn more about the kinetics of the process. Additional steeper facets of 27 inclination with respect to the (111) surface were observed in the low temperature regime. Furthermore, using facet-sensitive dark-field LEEM, spatial and size distributions of specific facets were studied for the different temperatures. Moreover, the facet dimensions were statistically analyzed. The total island size of the facets follows an exponential distribution, indicating a random growth mode in absence of any mutual facet interactions. While the length distribution of the facets also follows an exponential distribution, the width distribution is peaked, reflecting the high degree of lateral order. This anisotropy is temperature-dependent and occurs

  6. Seismic evaluation of existing nuclear power plants

    International Nuclear Information System (INIS)

    2003-01-01

    The IAEA nuclear safety standards publications address the site evaluation and the design of new nuclear power plants (NPPs), including seismic hazard assessment and safe seismic design, at the level of the Safety Requirements as well as at the level of dedicated Safety Guides. It rapidly became apparent that the existing nuclear safety standards documents were not adequate for handling specific issues in the seismic evaluation of existing NPPs, and that a dedicated document was necessary. This is the purpose of this Safety Report, which is written in the spirit of the nuclear safety standards and can be regarded as guidance for the interpretation of their intent. Worldwide experience shows that an assessment of the seismic capacity of an existing operating facility can be prompted for the following: (a) Evidence of a greater seismic hazard at the site than expected before, owing to new or additional data and/or to new methods; (b) Regulatory requirements, such as periodic safety reviews, to ensure that the plant has adequate margins for seismic loads; (c) Lack of anti-seismic design or poor anti-seismic design; (d) New technical finding such as vulnerability of some structures (masonry walls) or equipment (relays), other feedback and new experience from real earthquakes. Post-construction evaluation programmes evaluate the current capability of the plant to withstand the seismic concern and identify any necessary upgrades or changes in operating procedures. Seismic qualification is distinguished from seismic evaluation primarily in that seismic qualification is intended to be performed at the design stage of a plant, whereas seismic evaluation is intended to be applied after a plant has been constructed. Although some guidelines do exist for the evaluation of existing NPPs, these are not established at the level of a regulatory guide or its equivalent. Nevertheless, a number of existing NPPs throughout the world have been and are being subjected to review of their

  7. One-dimensional electron liquid at a surface. Gold nanowires on Ge(001)

    Energy Technology Data Exchange (ETDEWEB)

    Blumenstein, Christian

    2012-09-11

    Self-organized nanowires at semiconductor surfaces offer the unique opportunity to study electrons in reduced dimensions. Notably the dimensionality of the system determines it's electronic properties, beyond the quasiparticle description. In the quasi-one-dimensional (1D) regime with weak lateral coupling between the chains, a Peierls instability can be realized. A nesting condition in the Fermi surface leads to a backfolding of the 1D electron band and thus to an insulating state. It is accompanied by a charge density wave (CDW) in real space that corresponds to the nesting vector. This effect has been claimed to occur in many surface-defined nanowire systems, such as the In chains on Si(111) or the Au reconstructions on the terraced Si(553) and Si(557) surfaces. Therefore a weak coupling between the nanowires in these systems has to be concluded. However theory proposes another state in the perfect 1D limit, which is completely destroyed upon slight coupling to higher dimensions. In this so-called Tomonaga-Luttinger liquid (TLL) state, the quasiparticle description of the Fermi liquid breaks down. Since the interaction between the electrons is enhanced due to the strong confinement, only collective excitations are allowed. This leads to novel effects like spin charge separation, where spin and charge degrees of freedom are decoupled and allowed to travel independently along the 1D-chain. Such rare state has not been realized at a surface until today. This thesis uses a novel approach to realize nanowires with improved confinement by studying the Au reconstructed Ge(001) surface. A new cleaning procedure using piranha solution is presented, in order to prepare a clean and long-range ordered substrate. To ensure optimal growth of the Au nanowires the phase diagram is extensively studied by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The structural elements of the chains are revealed and described in high detail. Remarkably

  8. Surface structures of normal paraffins and cyclohexane monolayers and thin crystals grown on the (111) crystal face of platinum. A low-energy electron diffraction study

    International Nuclear Information System (INIS)

    Firment, L.E.; Somorjai, G.A.

    1977-01-01

    The surfaces of the normal paraffins (C 3 --C 8 ) and cyclohexane have been studied using low-energy electron diffraction (LEED). The samples were prepared by vapor deposition on the (111) face of a platinum single crystal in ultrahigh vacuum, and were studied both as thick films and as adsorbed monolayers. These molecules form ordered monolayers on the clean metal surface in the temperature range 100--220 K and at a vapor flux corresponding to 10 -7 Torr. In the adsorbed monolayers of the normal paraffins (C 4 --C 8 ), the molecules lie with their chain axes parallel to the Pt surface and Pt[110]. The paraffin monolayer structures undergo order--disorder transitions as a function of temperature. Multilayers condensed upon the ordered monolayers maintained the same orientation and packing as found in the monolayers. The surface structures of the growing organic crystals do not corresond to planes in their reported bulk crystal structures and are evidence for epitaxial growth of pseudomorphic crystal forms. Multilayers of n-octane and n-heptane condensed upon disordered monolayers have also grown with the (001) plane of the triclinic bulk crystal structures parallel to the surface. n-Butane has three monolayer structures on Pt(111) and one of the three is maintained during growth of the crystal. Cyclohexane forms an ordered monolayer, upon which a multilayer of cyclohexane grows exhibiting the (001) surface orientation of the monoclinic bulk crystal structure. Surface structures of saturated hydrocarbons are found to be very susceptible to electron beam induced damage. Surface charging interferes with LEED only at sample thicknesses greater than 200 A

  9. Does the Kuleshov Effect Really Exist?

    DEFF Research Database (Denmark)

    Barratt, Daniel; Rédei, Anna Cabak; Innes-Ker, Åse

    2016-01-01

    to replicate Kuleshov’s original experiment using an improved experimental design. In a behavioral and eye tracking study, 36 participants were each presented with 24 film sequences of neutral faces across six emotional conditions. For each film sequence, the participants were asked to evaluate the emotion...... of the target person in terms of valence, arousal, and category. The participants’ eye movements were recorded throughout. The results suggest that some sort of Kuleshov effect does in fact exist. For each emotional condition, the participants tended to choose the appropriate category more frequently than...... between the emotional conditions....

  10. Energy Savings Measure Packages. Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States); Booten, Chuck [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2011-11-01

    This document presents the most cost effective Energy Savings Measure Packages (ESMP) for existing mixed-fuel and all electric homes to achieve 15% and 30% savings for each BetterBuildings grantee location across the United States. These packages are optimized for minimum cost to homeowners for source energy savings given the local climate and prevalent building characteristics (i.e. foundation types). Maximum cost savings are typically found between 30% and 50% energy savings over the reference home; this typically amounts to $300 - $700/year.

  11. Analysis of field errors in existing undulators

    International Nuclear Information System (INIS)

    Kincaid, B.M.

    1990-01-01

    The Advanced Light Source (ALS) and other third generation synchrotron light sources have been designed for optimum performance with undulator insertion devices. The performance requirements for these new undulators are explored, with emphasis on the effects of errors on source spectral brightness. Analysis of magnetic field data for several existing hybrid undulators is presented, decomposing errors into systematic and random components. An attempts is made to identify the sources of these errors, and recommendations are made for designing future insertion devices. 12 refs., 16 figs

  12. Existence families, functional calculi and evolution equations

    CERN Document Server

    deLaubenfels, Ralph

    1994-01-01

    This book presents an operator-theoretic approach to ill-posed evolution equations. It presents the basic theory, and the more surprising examples, of generalizations of strongly continuous semigroups known as 'existent families' and 'regularized semigroups'. These families of operators may be used either to produce all initial data for which a solution in the original space exists, or to construct a maximal subspace on which the problem is well-posed. Regularized semigroups are also used to construct functional, or operational, calculi for unbounded operators. The book takes an intuitive and constructive approach by emphasizing the interaction between functional calculus constructions and evolution equations. One thinks of a semigroup generated by A as etA and thinks of a regularized semigroup generated by A as etA g(A), producing solutions of the abstract Cauchy problem for initial data in the image of g(A). Material that is scattered throughout numerous papers is brought together and presented in a fresh, ...

  13. Eternally existing self-reproducing inflationary universe

    International Nuclear Information System (INIS)

    Linde, A.D.

    1986-05-01

    It is shown that the large-scale quantum fluctuations of the scalar field φ generated in the chaotic inflation scenario lead to an infinite process of self-reproduction of inflationary mini-universes. A model of eternally existing chaotic inflationary universe is suggested. It is pointed out that whereas the universe locally is very homogeneous as a result of inflation, which occurs at the classical level, the global structure of the universe is determined by quantum effects and is highly non-trivial. The universe consists of exponentially large number of different mini-universes, inside which all possible (metastable) vacuum states and all possible types of compactification are realized. The picture differs crucially from the standard picture of a one-domain universe in a ''true'' vacuum state. Our results may serve as a justification of the anthropic principle in the inflationary cosmology. These results may have important implications for the elementary particle theory as well. Namely, since all possible types of mini-universes, in which inflation may occur, should exist in our universe, there is no need to insist (as it is usually done) that in realistic theories the vacuum state of our type should be the only possible one or the best one. (author)

  14. Organosulfur chemistry on W(211) surfaces. 2. A comparison of benzene, thiophene, and tetrahydrothiophene

    International Nuclear Information System (INIS)

    Preston, R.E.; Benziger, J.B.

    1985-01-01

    The interactions of benzene, thiophene, and tetrahydrothiophene with clean, oxidized, and sulfided W(211) surfaces were studied with LEED, AES, and temperature programmed reaction. Benzene and thiophene appear to absorb as bases making π-bonds to the surface. Benzene decomposed to yield adsorbed carbon and hydrogen. Thiophene appeared to undergo electrophilic attack at the 2-position forming a carbon bound surface intermediate. This surface intermediate was desulfurized and the resulting hydrocarbon surface intermediate underwent C-C bond scission forming C 3 hydrocarbons as the dominate desorption product. The electrophilic attack at the 2-position was shown by methyl group elimination from 2,5-dimethylthiophene. Adsorbed oxygen and sulfur enhanced the adsorption of benzene and thiophene by making the surface more acidic. Tetrahydrothiophene (THT) appear to adsorb as a base, forming a bond between the S(3p) electrons and the surface. Desulfurization of adsorbed THT led to C 4 hydrocarbons as the dominate desorption product. Adsorbed oxygen and sulfur inhibited reaction of THT. These results suggest that the surface reactivity and subsequent desulfurization of thiophene is controlled by electrophilic attack on the aromatic ring, and the ensuing reduction of resonance stabilization facilitates sulfur removal. 41 references, 8 figures, 4 tables

  15. Existing ingestion guidance: Problems and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Mooney, Robert R; Ziegler, Gordon L; Peterson, Donald S [Environmental Radiation Section, Division of Radiation Protection, WA (United States)

    1989-09-01

    Washington State has been developing plans and procedures for responding to nuclear accidents since the early 1970s. A key part of this process has been formulating a method for calculating ingestion pathway concentration guides (CGs). Such a method must be both technically sound and easy to use. This process has been slow and frustrating. However, much technical headway has been made in recent years, and hopefully the experience of the State of Washington will provide useful insight to problems with the existing guidance. Several recommendations are offered on ways to deal with these problems. In January 1986, the state held an ingestion pathway exercise which required the determination of allowed concentrations of isotopes for various foods, based upon reactor source term and field data. Objectives of the exercise were not met because of the complexity of the necessary calculations. A major problem was that the allowed concentrations had to be computed for each isotope and each food group, given assumptions on the average diet. To solve problems identified during that exercise, Washington developed, by March 1986, partitioned CGs. These CGs apportioned doses from each food group for an assumed mix of radionuclides expected to result from a reactor accident. This effort was therefore in place just in time for actual use during the Chernobyl fallout episode in May 1986. This technique was refined and described in a later report and presented at the 1987 annual meeting of the Health Physics Society. Realizing the technical weaknesses which still existed and a need to simplify the numbers for decision makers, Washington State has been developing computer methods to quickly calculate, from an accident specific relative mix of isotopes, CGs which allow a single radionuclide concentration for all food groups. This latest approach allows constant CGs for different periods of time following the accident, instead of peak CGs, which are good only for a short time after the

  16. Existing ingestion guidance: Problems and recommendations

    International Nuclear Information System (INIS)

    Mooney, Robert R.; Ziegler, Gordon L.; Peterson, Donald S.

    1989-01-01

    Washington State has been developing plans and procedures for responding to nuclear accidents since the early 1970s. A key part of this process has been formulating a method for calculating ingestion pathway concentration guides (CGs). Such a method must be both technically sound and easy to use. This process has been slow and frustrating. However, much technical headway has been made in recent years, and hopefully the experience of the State of Washington will provide useful insight to problems with the existing guidance. Several recommendations are offered on ways to deal with these problems. In January 1986, the state held an ingestion pathway exercise which required the determination of allowed concentrations of isotopes for various foods, based upon reactor source term and field data. Objectives of the exercise were not met because of the complexity of the necessary calculations. A major problem was that the allowed concentrations had to be computed for each isotope and each food group, given assumptions on the average diet. To solve problems identified during that exercise, Washington developed, by March 1986, partitioned CGs. These CGs apportioned doses from each food group for an assumed mix of radionuclides expected to result from a reactor accident. This effort was therefore in place just in time for actual use during the Chernobyl fallout episode in May 1986. This technique was refined and described in a later report and presented at the 1987 annual meeting of the Health Physics Society. Realizing the technical weaknesses which still existed and a need to simplify the numbers for decision makers, Washington State has been developing computer methods to quickly calculate, from an accident specific relative mix of isotopes, CGs which allow a single radionuclide concentration for all food groups. This latest approach allows constant CGs for different periods of time following the accident, instead of peak CGs, which are good only for a short time after the

  17. Integrating existing software toolkits into VO system

    Science.gov (United States)

    Cui, Chenzhou; Zhao, Yong-Heng; Wang, Xiaoqian; Sang, Jian; Luo, Ze

    2004-09-01

    Virtual Observatory (VO) is a collection of interoperating data archives and software tools. Taking advantages of the latest information technologies, it aims to provide a data-intensively online research environment for astronomers all around the world. A large number of high-qualified astronomical software packages and libraries are powerful and easy of use, and have been widely used by astronomers for many years. Integrating those toolkits into the VO system is a necessary and important task for the VO developers. VO architecture greatly depends on Grid and Web services, consequently the general VO integration route is "Java Ready - Grid Ready - VO Ready". In the paper, we discuss the importance of VO integration for existing toolkits and discuss the possible solutions. We introduce two efforts in the field from China-VO project, "gImageMagick" and "Galactic abundance gradients statistical research under grid environment". We also discuss what additional work should be done to convert Grid service to VO service.

  18. Seismic review of existing nuclear power plants

    International Nuclear Information System (INIS)

    Yanev, P.I.; Mayes, R.L.; Jones, L.R.

    1975-01-01

    Because of developments in the fields of earthquake and structural engineering over the last two decades, the codes, standards and design criteria for Nuclear Power Plants and other critical structures have changed substantially. As a result, plants designed only a few years ago do not satisfy the requirements for new plants. Accordingly, the Regulatory Agencies are requiring owners of older Nuclear Power Plants to re-qualify the plants seismically, using codes, standards, analytical techniques and knowledge developed in recent years. Seismic review consists of three major phases: establishing the design and performance criteria, re-qualifying the structures, and re-qualifying the equipment. The authors of the paper have been recently involved in the seismic review of existing nuclear power plants in the United States. This paper is a brief summary of their experiences

  19. Welfare Economics: A Story of Existence

    Directory of Open Access Journals (Sweden)

    Khalid Iqbal

    2017-06-01

    Full Text Available The purpose of this study is to explore that, despite severe challenges, welfare economics still exists. This descriptive study is conducted through some specific time line developments in this field. Economists are divided over the veracity and survival of the welfare economics. Welfare economics emphasizes on the optimum resource and goods allocation with the objective of better living standard, materialistic gains, social welfare and ethical decisions. It origins back to the political economics and utilitarianism. Adam Smith, Irving Fisher and Pareto contributed significantly towards it. During 1930 to 1940, American and British approaches were developed. Many economists tried to explore the relationship between level of income and happiness. Amartya Sen gave the comparative approach and Tinbergen pioneered the theory of equity. Contemporarily the futuristic restoration of welfare economics is on trial and hopes are alive. This study may be useful to understand the transitional and survival process of welfare economics.

  20. Testing Metadata Existence of Web Map Services

    Directory of Open Access Journals (Sweden)

    Jan Růžička

    2011-05-01

    Full Text Available For a general user is quite common to use data sources available on WWW. Almost all GIS software allow to use data sources available via Web Map Service (ISO/OGC standard interface. The opportunity to use different sources and combine them brings a lot of problems that were discussed many times on conferences or journal papers. One of the problem is based on non existence of metadata for published sources. The question was: were the discussions effective? The article is partly based on comparison of situation for metadata between years 2007 and 2010. Second part of the article is focused only on 2010 year situation. The paper is created in a context of research of intelligent map systems, that can be used for an automatic or a semi-automatic map creation or a map evaluation.

  1. On the existence of hot positronium reactions

    International Nuclear Information System (INIS)

    Lazzarini, E.

    1984-01-01

    The existence of hot Ps reactions is nowadays questioned; the controversy arises from the two models (the Ore gap and the spur theories) advanced in order to explain the mechanism of the positronium formation and of its inhibition in liquids by dissolution of certain compounds. The hypothesis of the hot Ps reactions was initially advanced as an additional statement for explaining the inhibition phenomenon within the framework of the Ore gap theory, but it is not considered necessary for the spur theory. The present paper is chiefly intended as a presentation of this particular aspect of Ps chemistry to hot atom chemists unspecialized in the field. The reader is assumed to be familiar with the basic physics and experimental methods used in positronium chemistry. Contents: positrons and positronium formation; inhibition and enhancement of Ps formation in solutions; positronium reactions in gases. (Auth.)

  2. Sustainability in the existing building stock

    DEFF Research Database (Denmark)

    Elle, Morten; Nielsen, Susanne Balslev; Hoffmann, Birgitte

    2005-01-01

    , QRWfacilities management’s most important contribution to sustainable development in the built environment. Space management is an essential tool in facilities management – and it could be considered a powerful tool in sustainable development; remembering that the building not being built is perhaps the most......This paper explores the role of Facilities Management in the relation to sustainable development in the existing building stock. Facilities management is a concept still developing as the management of buildings are becoming more and more professional. Many recognize today that facilities...... management is a concept relevant to others than large companies. Managing the flows of energy and other resources is a part of facilities management, and an increased professionalism could lead to the reduction of the use of energy and water and the generation of waste and wastewater. This is, however...

  3. Compilation of Existing Neutron Screen Technology

    Directory of Open Access Journals (Sweden)

    N. Chrysanthopoulou

    2014-01-01

    Full Text Available The presence of fast neutron spectra in new reactors is expected to induce a strong impact on the contained materials, including structural materials, nuclear fuels, neutron reflecting materials, and tritium breeding materials. Therefore, introduction of these reactors into operation will require extensive testing of their components, which must be performed under neutronic conditions representative of those expected to prevail inside the reactor cores when in operation. Due to limited availability of fast reactors, testing of future reactor materials will mostly take place in water cooled material test reactors (MTRs by tailoring the neutron spectrum via neutron screens. The latter rely on the utilization of materials capable of absorbing neutrons at specific energy. A large but fragmented experience is available on that topic. In this work a comprehensive compilation of the existing neutron screen technology is attempted, focusing on neutron screens developed in order to locally enhance the fast over thermal neutron flux ratio in a reactor core.

  4. [The depression epidemic does not exist].

    Science.gov (United States)

    van der Feltz-Cornelis, Christina M

    2009-01-01

    There has been much discussion in the media about the question of the existence of a depression epidemic. This leads on to the questions of whether the social and economic approaches are adequate, and what the alternatives are. The concept of the disease 'depression' can be defined using a medical model, or from a patient's or a societal perspective. From a medical perspective, indeed a depression epidemic has ensued from the increased prosperity and the associated decompression of the mortality rate. Society responded with preventative measures and policies aimed at improving functioning in the workplace. However, patients with a major depressive disorder (MDD) who are eligible for treatment are often not motivated to take it up, or are undertreated. Research is necessary in order to explore what patients think about the identification and treatment of depression. The confusion regarding the concept of depression found in the media, needs to be cleared.

  5. On the existence of Levi Foliations

    Directory of Open Access Journals (Sweden)

    RENATA N. OSTWALD

    2001-03-01

    Full Text Available Let L be a real 3 dimensional analytic variety. For each regular point p L there exists a unique complex line l p on the space tangent to L at p. When the field of complex line p l p is completely integrable, we say that L is Levi variety. More generally; let L M be a real subvariety in an holomorphic complex variety M. If there exists a real 2 dimensional integrable distribution on L which is invariant by the holomorphic structure J induced by M, we say that L is a Levi variety. We shall prove: Theorem. Let be a Levi foliation and let be the induced holomorphic foliation. Then, admits a Liouvillian first integral. In other words, if is a 3 dimensional analytic foliation such that the induced complex distribution defines an holomorphic foliation ; that is, if is a Levi foliation; then admits a Liouvillian first integral--a function which can be constructed by the composition of rational functions, exponentiation, integration, and algebraic functions (Singer 1992. For example, if f is an holomorphic function and if theta is real a 1-form on ; then the pull-back of theta by f defines a Levi foliation : f*theta = 0 which is tangent to the holomorphic foliation : df = 0. This problem was proposed by D. Cerveau in a meeting (see Fernandez 1997.Seja L Ì uma variedade real de dimensão 3. Para todo ponto regular p Î L existe uma única reta complexa l p no espaço tangente à L em p. Quando o campo de linhas complexas p l p é completamente integrável, dizemos que L é uma variedade de Levi. Mais geralmente, seja L Ì M uma subvariedade real em uma variedade analítica complexa. Se existe uma distribuição real integrável de dimensão 2 em L que é invariante pela estrutura holomorfa J induzida pela variedade complexa M, dizemos que L é uma variedade de Levi. Vamos provar: Teorema. Seja uma folheação de Levi e seja a folheação holomorfa induzida. Então tem integral primeira Liouvilliana. Em outras palavras, se é uma folheação real de

  6. How many N = 4 strings exist?

    International Nuclear Information System (INIS)

    Ketov, S.V.

    1994-09-01

    Possible ways of constructing extended fermionic strings with N=4 world-sheet supersymmetry are reviewed. String theory constraints form, in general, a non-linear quasi(super)conformal algebra, and can have conformal dimensions ≥1. When N=4, the most general N=4 quasi-superconformal algebra to consider for string theory building is D(1, 2; α), whose linearisation is the so-called ''large'' N=4 superconformal algebra. The D(1, 2; α) algebra has su(2)sub(κ + )+su(2)sub(κ - )+u(1) Kac-Moody component, and α=κ - /κ + . We check the Jacobi identities and construct a BRST charge for the D(1, 2; α) algebra. The quantum BRST operator can be made nilpotent only when κ + =κ - =-2. The D(1, 2; 1) algebra is actually isomorphic to the SO(4)-based Bershadsky-Knizhnik non-linear quasi-superconformal algebra. We argue about the existence of a string theory associated with the latter, and propose the (non-covariant) hamiltonian action for this new N=4 string theory. Our results imply the existence of two different N=4 fermionic string theories: the old one based on the ''small'' linear N=4 superconformal algebra and having the total ghost central charge c gh =+12, and the new one with non-linearly realised N=4 supersymmetry, based on the SO(4) quasi-superconformal algebra and having c gh =+6. Both critical string theories have negative ''critical dimensions'' and do not admit unitary matter representations. (orig.)

  7. Rare earth silicide nanowires on silicon surfaces

    International Nuclear Information System (INIS)

    Wanke, Martina

    2008-01-01

    The growth, structure and electronic properties of rare earth silicide nanowires are investigated on planar and vicinal Si(001) und Si(111) surfaces with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy (ARPES). On all surfaces investigated within this work hexagonal disilicides are grown epitaxially with a lattice mismatch of -2.55% up to +0.83% along the hexagonal a-axis. Along the hexagonal c-axis the lattice mismatch is essentially larger with 6.5%. On the Si(001)2 x 1 surface two types of nanowires are grown epitaxially. The socalled broad wires show a one-dimensional metallic valence band structure with states crossing the Fermi level. Along the nanowires two strongly dispersing states at the anti J point and a strongly dispersing state at the anti Γ point can be observed. Along the thin nanowires dispersing states could not be observed. Merely in the direction perpendicular to the wires an intensity variation could be observed, which corresponds to the observed spacial structure of the thin nanowires. The electronic properties of the broad erbium silicide nanowires are very similar to the broad dysprosium silicide nanowires. The electronic properties of the DySi 2 -monolayer and the Dy 3 Si 5 -multilayer on the Si(111) surface are investigated in comparison to the known ErSi 2 /Si(111) and Er 3 Si 5 /Si(111) system. The positions and the energetic locations of the observed band in the surface Brillouin zone will be confirmed for dysprosium. The shape of the electron pockets in the vector k parallel space is elliptical at the anti M points, while the hole pocket at the anti Γ point is showing a hexagonal symmetry. On the Si(557) surface the structural and electronic properties depend strongly on the different preparation conditions likewise, in particular on the rare earth coverage. At submonolayer coverage the thin nanowires grow in wide areas of the sample surface, which are oriented

  8. Energy consumptions in existing buildings; Les consommations d'energie des batiments existants

    Energy Technology Data Exchange (ETDEWEB)

    Nuss, St. [Ecole Nationale Superieure des Arts et Industries de Strasbourg, 78 - Saint-Remy-Les-Chevreuse (France)]|[Costic, 78 - Sainte Remy les Chevreuses (France)

    2002-05-01

    This document presents a sectoral analysis of the energy consumptions in existing French buildings: 1) - residential sector: social buildings, private dwellings; 2) - tertiary sector: office buildings, hotels, commercial buildings, school buildings, hospitals; 3) - industry; 4) - general status. (J.S.)

  9. Review of existing landfill leachate production models

    International Nuclear Information System (INIS)

    Khan, T.A.

    2000-01-01

    The protection of water resources is a fundamental consideration in managing landfill operations. Landfill sites should be designed and operated so as to control leachate production and hence minimize the risk of surface and ground water pollution. A further important development is the use of computer models to estimate the production of leachate from landfill sites. It is revealed from the literature that a number of landfill leachate management model lave been development in recent years. These models allow different engineering schemes to be evaluated and are essential tools for design and operation managements of modern landfills. This paper describes a review of such models mainly focused on their theory, practicability, data requirements, suitability to real situation and usefulness. An evaluation of these models identifies. (author)

  10. Defect and structural imperfection effects on the electronic properties of BiTeI surfaces

    International Nuclear Information System (INIS)

    Fiedler, Sebastian; Seibel, Christoph; Lutz, Peter; Bentmann, Hendrik; Reinert, Friedrich; El-Kareh, Lydia; Bode, Matthias; Eremeev, Sergey V; Tereshchenko, Oleg E; Kokh, Konstantin A; Chulkov, Evgueni V; Kuznetsova, Tatyana V; Grebennikov, Vladimir I

    2014-01-01

    The surface electronic structure of the narrow-gap seminconductor BiTeI exhibits a large Rashba-splitting which strongly depends on the surface termination. Here we report on a detailed investigation of the surface morphology and electronic properties of cleaved BiTeI single crystals by scanning tunneling microscopy, photoelectron spectroscopy (ARPES, XPS), electron diffraction (SPA-LEED) and density functional theory calculations. Our measurements confirm a previously reported coexistence of Te- and I-terminated surface areas originating from bulk stacking faults and find a characteristic length scale of ∼100 nm for these areas. We show that the two terminations exhibit distinct types of atomic defects in the surface and subsurface layers. For electronic states resided on the I terminations we observe an energy shift depending on the time after cleavage. This aging effect is successfully mimicked by depositon of Cs adatoms found to accumulate on top of the I terminations. As shown theoretically on a microscopic scale, this preferential adsorbing behaviour results from considerably different energetics and surface diffusion lengths at the two terminations. Our investigations provide insight into the importance of structural imperfections as well as intrinsic and extrinsic defects on the electronic properties of BiTeI surfaces and their temporal stability. (paper)

  11. Effectiveness of Existing International Nuclear Liability Regime

    International Nuclear Information System (INIS)

    Al-Doais, Salwa; Kessel, Daivd

    2015-01-01

    The first convention was the Paris Convention on Third Party Liability in the Field of Nuclear Energy (the Paris Convention) had been adopted on 29 July 1960 under the auspices of the OECD, and entered into force on 1 April 1968. In 1963,the Brussels Convention - supplementary to the Paris Convention- was adopted in to provide additional funds to compensate damage as a result of a nuclear incident where Paris Convention funds proved to be insufficient. The IAEA's first convention was the Vienna Convention on Civil Liability for Nuclear Damage (the Vienna Convention) which adopted on 21 May 1963,and entered into force in 1977. Both the Paris Convention and the Vienna Convention laid down very similar nuclear liability rules based on the same general principles. The broad principles in these conventions can be summarized as follows: 1- The no-fault liability principle (strict liability) 2- Liability is channeled exclusively to the operator of the nuclear installation (legal channeling) 3- Only courts of the state in which the nuclear accident occurs would have jurisdiction (exclusive jurisdiction) 4- Limitation of the amount of liability and the time frame for claiming damages (limited liability) 5- The operator is required to have adequate insurance or financial guarantees to the extent of its liability amount (liability must be financially secured). 6- Liability is limited in time. Compensation rights are extinguished after specific time. 7- Non-discrimination of victims on the grounds of nationality, domicile or residence. Nuclear liability conventions objective is to provide adequate compensation payments to victims of a nuclear accident. Procedures for receiving these compensation are controlled by some rules such as exclusive jurisdiction, that rule need a further amendment to ensure the effectiveness of the exiting nuclear liability regime . Membership of the Conventions is a critical issue, because the existence of the conventions without being party to

  12. Existing facilities and past practices: Lessons learned

    International Nuclear Information System (INIS)

    Huizenga, D.; Tonkay, D.W.; Owens, K.

    2000-01-01

    Article 12 of the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (Joint Convention) requires parties to the Joint Convention to review the safety of existing radioactive waste management facilities 'to ensure that, if necessary, all reasonably practicable improvements are made to upgrade the safety of such a facility'. Also required is a review of the results of past practices to determine 'whether any intervention is needed for reasons of radiation protection' and to consider whether the benefits of the intervention or remediation are sufficient, with regard to the costs and the impact on workers, the public and the environment. This paper discusses the experience of the United States Department of Energy in terms of the lessons learned from operating radioactive waste management facilities and from undertaking intervention or remedial action, and from decision making in an international context. Overarching safety principles are discussed, including integrating safety into all work practices and minimizing the generation of waste. Safety review lessons learned with existing facilities are discussed with respect to: applying new requirements to old facilities, taking a life-cycle perspective of waste management, improving high level waste facility management, and blending current and past practices with respect to the process used to arrive at decisions for intervention. Special emphasis is placed on the need to provide for early and substantive input from the involved regulatory agencies, Native American tribes, and those citizens and groups with an interest in the decisions. Examples of intervention decisions are discussed, including examples taken from uranium mill tailings operations, from cleanup of a former uranium processing plant site, from evaluation of pre-1970 buried 'transuranic waste' sites, and from decommissioning or closure of high level waste storage tanks. The paper concludes that on the

  13. Measuring Input Thresholds on an Existing Board

    Science.gov (United States)

    Kuperman, Igor; Gutrich, Daniel G.; Berkun, Andrew C.

    2011-01-01

    A critical PECL (positive emitter-coupled logic) interface to Xilinx interface needed to be changed on an existing flight board. The new Xilinx input interface used a CMOS (complementary metal-oxide semiconductor) type of input, and the driver could meet its thresholds typically, but not in worst-case, according to the data sheet. The previous interface had been based on comparison with an external reference, but the CMOS input is based on comparison with an internal divider from the power supply. A way to measure what the exact input threshold was for this device for 64 inputs on a flight board was needed. The measurement technique allowed an accurate measurement of the voltage required to switch a Xilinx input from high to low for each of the 64 lines, while only probing two of them. Directly driving an external voltage was considered too risky, and tests done on any other unit could not be used to qualify the flight board. The two lines directly probed gave an absolute voltage threshold calibration, while data collected on the remaining 62 lines without probing gave relative measurements that could be used to identify any outliers. The PECL interface was forced to a long-period square wave by driving a saturated square wave into the ADC (analog to digital converter). The active pull-down circuit was turned off, causing each line to rise rapidly and fall slowly according to the input s weak pull-down circuitry. The fall time shows up as a change in the pulse width of the signal ready by the Xilinx. This change in pulse width is a function of capacitance, pulldown current, and input threshold. Capacitance was known from the different trace lengths, plus a gate input capacitance, which is the same for all inputs. The pull-down current is the same for all inputs including the two that are probed directly. The data was combined, and the Excel solver tool was used to find input thresholds for the 62 lines. This was repeated over different supply voltages and

  14. Effectiveness of Existing International Nuclear Liability Regime

    Energy Technology Data Exchange (ETDEWEB)

    Al-Doais, Salwa; Kessel, Daivd [KEPCO International Nuclear Graduate School, Daejeon (Korea, Republic of)

    2015-10-15

    The first convention was the Paris Convention on Third Party Liability in the Field of Nuclear Energy (the Paris Convention) had been adopted on 29 July 1960 under the auspices of the OECD, and entered into force on 1 April 1968. In 1963,the Brussels Convention - supplementary to the Paris Convention- was adopted in to provide additional funds to compensate damage as a result of a nuclear incident where Paris Convention funds proved to be insufficient. The IAEA's first convention was the Vienna Convention on Civil Liability for Nuclear Damage (the Vienna Convention) which adopted on 21 May 1963,and entered into force in 1977. Both the Paris Convention and the Vienna Convention laid down very similar nuclear liability rules based on the same general principles. The broad principles in these conventions can be summarized as follows: 1- The no-fault liability principle (strict liability) 2- Liability is channeled exclusively to the operator of the nuclear installation (legal channeling) 3- Only courts of the state in which the nuclear accident occurs would have jurisdiction (exclusive jurisdiction) 4- Limitation of the amount of liability and the time frame for claiming damages (limited liability) 5- The operator is required to have adequate insurance or financial guarantees to the extent of its liability amount (liability must be financially secured). 6- Liability is limited in time. Compensation rights are extinguished after specific time. 7- Non-discrimination of victims on the grounds of nationality, domicile or residence. Nuclear liability conventions objective is to provide adequate compensation payments to victims of a nuclear accident. Procedures for receiving these compensation are controlled by some rules such as exclusive jurisdiction, that rule need a further amendment to ensure the effectiveness of the exiting nuclear liability regime . Membership of the Conventions is a critical issue, because the existence of the conventions without being party to

  15. Existing reflection seismic data re-processing

    International Nuclear Information System (INIS)

    Higashinaka, Motonori; Sano, Yukiko; Kozawa, Takeshi

    2005-08-01

    This document is to report the results of existing seismic data re-processing around Horonobe town, Hokkaido, Japan, which is a part of the Horonobe Underground Research Project. The main purpose of this re-processing is to recognize the subsurface structure of Omagari Fault and fold system around Omagari Fault. The seismic lines for re-processing are TYHR-A3 line and SHRB-2 line, which JAPEX surveyed in 1975. Applying weathering static correction using refraction analysis and noise suppression procedure, we have much enhanced seismic profile. Following information was obtained from seismic re-processing results. TYHR-A3 line: There are strong reflections, dipping to the west. These reflections are corresponding western limb of anticline to the west side of Omagari Fault. SHRB-2 line: There are strong reflections, dipping to the west, at CDP 60-140, while there are reflections, dipping to the east, to the east side of CDP 140. These reflections correspond to the western limb and the eastern limb of the anticline, which is parallel to Omagari FAULT. This seismic re-processing provides some useful information to know the geological structure around Omagari Fault. (author)

  16. On the Existence of Evolutionary Learning Equilibriums

    Directory of Open Access Journals (Sweden)

    Masudul Alam Choudhury

    2011-12-01

    Full Text Available The usual kinds of Fixed-Point Theorems formalized on the existence of competitive equilibrium that explain much of economic theory at the core of economics can operate only on bounded and closed sets with convex mappings. But these conditions are hardly true of the real world of economic and financial complexities and perturbations. The category of learning sets explained by continuous fields of interactive, integrative and evolutionary behaviour caused by dynamic preferences at the individual and institutional and social levels cannot maintain the assumption of closed, bounded and convex sets. Thus learning sets and multi-system inter-temporal relations explained by pervasive complementarities and  participation between variables and entities, and evolution by learning, have evolutionary equilibriums. Such a study requires a new methodological approach. This paper formalizes such a methodology for evolutionary equilibriums in learning spaces. It briefly points out the universality of learning equilibriums in all mathematical structures. For a particular case though, the inter-systemic interdependence between sustainable development and ethics and economics in the specific understanding of learning domain is pointed out.

  17. Does the chromatic Mach bands effect exist?

    Science.gov (United States)

    Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

    2009-06-30

    The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

  18. Evaluation and modification of existing CETP.

    Science.gov (United States)

    Sharma, Bhavisha; Shah, A R

    2013-07-01

    For the development of small and medium scale industries in various Gujarat industrial development corporation (GIDC) areas and in clusters of industrial areas, the common effluent treatment plant (CETP) has always been found advantageous in view of cost of treatment, operation and maintenance and disposal of residues being produced. In small scale industrial units due to market requirement, product changes and quantity enhancement are taking place. Due to such changes, the effluent characteristics are continuously changing which affects performance of CETP. Hence it has been found necessary to study continuously the performance, evaluation and modification in the working of the CETP. This paper contains a case study of one of the existing CETP near Baroda which is facing the problem of disposal of treated effluent in which the important parameters like COD, BOD, Suspended Solid, NH3-N and oil and grease were analyzed. Based on the characterization of wastewater, the various treatability studies were carried out on CETP wastewater. To comply with disposal standard prescribed by Effluent Channel Project Ltd.(ECPL)* and Gujarat Pollution Control Board (GPCB) for discharge of industrial effluent into channel, various treatments in form of ammonia stripping, coagulation and flocculation, biological treatment, filtration and chlorination are suggested.

  19. On the existence of tropical anvil clouds

    Science.gov (United States)

    Seeley, J.; Jeevanjee, N.; Langhans, W.; Romps, D.

    2017-12-01

    In the deep tropics, extensive anvil clouds produce a peak in cloud cover below the tropopause. The dominant paradigm for cloud cover attributes this anvil peak to a layer of enhanced mass convergence in the clear-sky upper-troposphere, which is presumed to force frequent detrainment of convective anvils. However, cloud cover also depends on the lifetime of cloudy air after it detrains, which raises the possibility that anvil clouds may be the signature of slow cloud decay rather than enhanced detrainment. Here we measure the cloud decay timescale in cloud-resolving simulations, and find that cloudy updrafts that detrain in the upper troposphere take much longer to dissipate than their shallower counterparts. We show that cloud lifetimes are long in the upper troposphere because the saturation specific humidity becomes orders of magnitude smaller than the typical condensed water loading of cloudy updrafts. This causes evaporative cloud decay to act extremely slowly, thereby prolonging cloud lifetimes in the upper troposphere. As a consequence, extensive anvil clouds still occur in a convecting atmosphere that is forced to have no preferential clear-sky convergence layer. On the other hand, when cloud lifetimes are fixed at a characteristic lower-tropospheric value, extensive anvil clouds do not form. Our results support a revised understanding of tropical anvil clouds, which attributes their existence to the microphysics of slow cloud decay rather than a peak in clear-sky convergence.

  20. Bibliography - Existing Guidance for External Hazard Modelling

    International Nuclear Information System (INIS)

    Decker, Kurt

    2015-01-01

    The bibliography of deliverable D21.1 includes existing international and national guidance documents and standards on external hazard assessment together with a selection of recent scientific papers, which are regarded to provide useful information on the state of the art of external event modelling. The literature database is subdivided into International Standards, National Standards, and Science Papers. The deliverable is treated as a 'living document' which is regularly updated as necessary during the lifetime of ASAMPSA-E. The current content of the database is about 140 papers. Most of the articles are available as full-text versions in PDF format. The deliverable is available as an EndNote X4 database and as text files. The database includes the following information: Reference, Key words, Abstract (if available), PDF file of the original paper (if available), Notes (comments by the ASAMPSA-E consortium if available) The database is stored at the ASAMPSA-E FTP server hosted by IRSN. PDF files of original papers are accessible through the EndNote software

  1. Chemical waves in the O2 + H2 reaction on a Rh(111) surface alloyed with nickel. I. Photoelectron emission microscopy

    Science.gov (United States)

    Smolinsky, Tim; von Boehn, Bernhard; Imbihl, Ronald

    2018-04-01

    Chemical waves that arise in the H2 + O2 reaction on a bimetallic Rh(111)/Ni surface have been studied in the 10-6 and 10-5 mbar range at T = 773 K with photoelectron emission microscopy (PEEM), low-energy electron diffraction (LEED), and Auger electron spectroscopy (AES). Nickel coverages of 0.3, 0.6, and 1.0 monolayers were investigated. Coadsorbed with some oxygen, Ni starts to penetrate the Rh bulk region substantially only beyond 900 K. In the 10-5 mbar range, chemical waves are characterized by three distinct gray levels in PEEM. This number reduces to only two levels in the 10-6 mbar range. In situ LEED showed the periodic appearance of a (n × 1) (n = 8, 10) pattern during chemical waves which was assigned to a 2D-Ni oxide. With in situ AES, one observes that the bright phase in PEEM correlates with a high Ni coverage and the dark phase with a low Ni coverage.

  2. Surface diffusion of sorbed radionuclides

    International Nuclear Information System (INIS)

    Berry, J.A.; Bond, K.A.

    1991-01-01

    Surface diffusion has in the past been invoked to explain rates of radionuclide migration which were greater than those predicted. Results were generally open to interpretation but the possible existence of surface diffusion, whereby sorbed radionuclides could potentially migrate at much enhanced rates, necessitated investigation. In this work through-diffusion experiments have shown that although surface diffusion does exist for some nuclides, the magnitude of the phenomenon is not sufficient to affect repository safety assessment modelling. (author)

  3. Overview of existing cartilage repair technology.

    Science.gov (United States)

    McNickle, Allison G; Provencher, Matthew T; Cole, Brian J

    2008-12-01

    Currently, autologous chondrocyte implantation and osteochondral grafting bridge the gap between palliation of cartilage injury and resurfacing via arthroplasty. Emerging technologies seek to advance first generation techniques and accomplish several goals including predictable outcomes, cost-effective technology, single-stage procedures, and creation of durable repair tissue. The biologic pipeline represents a variety of technologies including synthetics, scaffolds, cell therapy, and cell-infused matrices. Synthetic constructs, an alternative to biologic repair, resurface a focal chondral defect rather than the entire joint surface. Scaffolds are cell-free constructs designed as a biologic "net" to augment marrow stimulation techniques. Minced cartilage technology uses stabilized autologous or allogeneic fragments in 1-stage transplantation. Second and third generation cell-based methods include alternative membranes, chondrocyte seeding, and culturing onto scaffolds. Despite the promising early results of these products, significant technical obstacles remain along with unknown long-term durability. The vast array of developing technologies has exceptional promise and the potential to revolutionize the cartilage treatment algorithm within the next decade.

  4. MELCOR development for existing and advanced reactors

    International Nuclear Information System (INIS)

    Summers, R.M.

    1993-01-01

    Recent efforts in MELCOR development to address previously identified deficiencies have resulted in release of MELCOR 1.8.2, a much-improved version of the code. Major new models have been implemented for direct containment heating, ice condensers, debris quenching, lower plenum debris behavior, core materials interactions' and radial relocation of debris. Significant improvements have also been made in the modeling of interfacial momentum exchange and in the modeling of fission product release, condensation/evaporation, and aerosol behavior. Efforts are underway to address two-phase hydrodynamics difficulties, to improve modeling of water condensation on structures and fine-scale natural circulation within the reactor vessel, and to implement CORCON-Mod3. Improvements are also being made to MELCOR's capability to handle new features of the advanced light water reactor designs, including drainage of water films on connected heat structures, heat transfer from the external surface of the reactor vessel to a flooded cavity, and creep rupture failure of the lower head. Additional development needs in other areas are discussed

  5. Interim Storage of Plutonium in Existing Facilities

    International Nuclear Information System (INIS)

    Woodsmall, T.D.

    1999-01-01

    'In this era of nuclear weapons disarmament and nonproliferation treaties, among many problems being faced by the Department of Energy is the safe disposal of plutonium. There is a large stockpile of plutonium at the Rocky Flats Environmental Technology Center and it remains politically and environmentally strategic to relocate the inventory closer to a processing facility. Savannah River Site has been chosen as the final storage location, and the Actinide Packaging and Storage Facility (APSF) is currently under construction for this purpose. With the ability of APSF to receive Rocky Flats material an estimated ten years away, DOE has decided to use the existing reactor building in K-Area of SRS as temporary storage to accelerate the removal of plutonium from Rocky Flats. There are enormous cost savings to the government that serve as incentive to start this removal as soon as possible, and the KAMS project is scheduled to receive the first shipment of plutonium in January 2000. The reactor building in K-Area was chosen for its hardened structure and upgraded seismic qualification, both resulting from an effort to restart the reactor in 1991. The KAMS project has faced unique challenges from Authorization Basis and Safety Analysis perspectives. Although modifying a reactor building from a production facility to a storage shelter is not technically difficult, the nature of plutonium has caused design and safety analysis engineers to make certain that the design of systems, structures and components included will protect the public, SRS workers, and the environment. A basic overview of the KAMS project follows. Plutonium will be measured and loaded into DOT Type-B shipping packages at Rocky Flats. The packages are 35-gallon stainless steel drums with multiple internal containment boundaries. DOE transportation vehicles will be used to ship the drums to the KAMS facility at SRS. They will then be unloaded, stacked and stored in specific locations throughout the

  6. Sharing information among existing data sources

    Science.gov (United States)

    Ashley, W. R., III

    1999-01-01

    The sharing of information between law enforcement agencies is a premise for the success of all jurisdictions. A wealth of information resides in both the databases and infrastructures of local, state, and regional agencies. However, this information is often not available to the law enforcement professionals who require it. When the information is, available, individual investigators must not only know that it exists, but where it resides, and how to retrieve it. In many cases, these types of cross-jurisdictional communications are limited to personal relationships that result from telephone calls, faxes, and in some cases, e-mail. As criminal elements become more sophisticated and distributed, law enforcement agencies must begin to develop infrastructures and common sharing mechanisms that address a constantly evolving criminal threat. Historically, criminals have taken advantage of the lack of communication between law enforcement agencies. Examples of this are evident in the search for stolen property and monetary dealings. Pawned property, cash transactions, and failure to supply child support are three common cross- jurisdictional crimes that could be better enforced by strengthening the lines of communication. Criminal behavior demonstrates that it is easier to profit from their actions by dealing in separate jurisdictions. For example, stolen property is sold outside of the jurisdiction of its origin. In most cases, simply traveling a short distance to the adjoining county or municipality is sufficient to ensure that apprehension of the criminal or seizure of the stolen property is highly unlikely. In addition to the traditional burglar, fugitives often sell or pawn property to finance their continued evasion from the law. Sharing of information in a rapid manner would increase the ability of law enforcement personnel to track and capture fugitives, as well as criminals. In an example to combat this threat, the State of Florida recently acted on the need to

  7. Seismic evaluation of existing nuclear facilities. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    Programmes for re-evaluation and upgrading of safety of existing nuclear facilities are presently under way in a number of countries around the world. An important component of these programmes is the re-evaluation of the seismic safety through definition of new seismic parameters at the site and evaluation of seismic capacity of structures, equipment and distribution systems following updated information and criteria. The Seminar is intended to provide a forum for the exchange of information and discussion of the state-of-the-art on seismic safety of nuclear facilities in operation or under construction. Both analytical and experimental techniques for the evaluation of seismic capacity of structures, equipment and distribution systems are discussed. Full scale and field tests of structures and components using shaking tables, mechanical exciters, explosive and shock tests, and ambient vibrations are included in the seminar programme with emphasis on recent case histories. Presentations at the Seminar also include analytical techniques for the determination of dynamic properties of soil-structure systems from experiments as well as calibration of numerical models. Methods and criteria for seismic margin assessment based on experience data obtained from the behaviour of structures and components in real earthquakes are discussed. Guidelines for defining technical requirements for capacity re-evaluation (i.e. acceptable behaviour limits and design and implementation of structure and components upgrades are also presented and discussed. The following topics were covered during 7 sessions: earthquake experience and seismic re-evaluation; country experience in seismic re-evaluation programme; generic WWER studies; analytical methods for seismic capacity re-evaluation; experimental methods for seismic capacity re-evaluation; case studies.

  8. Does Glocal Political Power Already Exist?

    Directory of Open Access Journals (Sweden)

    Lorenzo Ornaghi

    2017-05-01

    Full Text Available Large periods of history are usually characterized by equally important moments of change in scientific knowledge and, in particular, in the understanding of political power. We still need to study in depth whether the former provokes (almost of out necessity the latter, or whether they are “great” because they are favored by the innovation of the paradigms of knowledge. The passage from medieval universalism to the particularism of the modern age represents an extremely interesting analogy when compared to the transformations that are now underway. The example of John of Salisbury’s Policratus, the starting point of this article, is illuminating in our comprehension of the relevance of the interweaving between the persistence of the ancient forms of recognition of power and the search for new forms. The existence of glocal realities is already a fact. Even if it is relatively easy to recognize these realities (a business, a university, a humanitarian association, not a few of the same “parts” which constitute the traditional organization of the State, it is more difficult to define the specific characteristics of the power at their disposal. Moving from the widening gap between “actual” power and “potential” power, the article examines the motives for which the classical definitions of power are always becoming more insufficient in understanding the role now emerging from glocal realities. And, in particular, by looking at how the “command-obedience” relationship is changing also as a consequence of communication networks and information technology, the article analyzes that specific “contamination” within global elements and local elements, which seems to be the main base of glocal political power.

  9. David Barker: the revolution that anticipates existence

    Directory of Open Access Journals (Sweden)

    Italo Farnetani

    2014-01-01

    Full Text Available David Barker is the man who “anticipated" the existence of babies by focusing attention on the importance of the fetus and what takes place during intrauterine life. Barker was one of the physicians who in the last decades brought about the greatest changes in medicine, changes so important as to represent a veritable revolution in medical thought. According to Barker's studies, the embryo obviously has a genetic complement coming from the mother and father, but from the very first stages of development it begins to undergo the influence of the outside environment, just as occurs for adults whose biological, psychological and pathological aspects are influenced by the environment to a not well-established percentage between genetic complement and epigenetics. Much of our future lives as adults is decided in our mothers' wombs. If Barker's discovery was revolutionary from the cultural standpoint, it was even more so from the strictly medical one. Barker's research method was rigid from the methodological standpoint, but innovative and speculative in its working hypotheses, with a humanistic slant. Barker's idea has another practical corollary: it is evident that the role of obstetricians, perinatologists and neonatologists is more and more relevant in medicine and future prevention. Unquestionably, besides the enormous merits of his clinical research, among the benefits that Barker has contributed there is that of having helped us to see things from new points of view. Not only is the neonate (and even more so the fetus not an adult of reduced proportions, but perhaps the neonate is the "father" of the adult person.

  10. Virtual existence in contemporary Serbian novel

    Directory of Open Access Journals (Sweden)

    Gordić-Petković Vladislava S.

    2017-01-01

    Full Text Available The paper sets out to explore the perspectives and strategies of virtual existence in contemporary Serbian novel in order to illustrate radical changes in the concept of reality and writers' concern with the fidelity to experience. A new surge of the so-called digital realism emerges simultaneously with the increase of awareness that the line between our digital selves and our real-world selves has become blurred and difficult to explain, while new technologies are required to go beyond what our human senses can encompass and deliver. The fictional realism of the digital age will also commit itself to young or middle-aged individuals that passionately attempt to define their aims and objectives so that they could fit into a newly constructed and acquired concept of reality. This is the case with the protagonists in the novels by Ivančica Đerić, Tamara Jecić and Aleksandar Ilić, all of them questioning both their offline and online identities. Their everyday life in a postmillennial world includes many intersecting empirical and virtual realities: love, career and sex take place in a dimension which ignores geography and physical distance and ultimately alters the concepts of time and space, as well the concepts of privacy and intimacy. The paper intends to examine the ways new digital technologies contribute to representations of reality in the novels of both accomplished and aspiring authors whose novels deal with ways of life amid social networks. The novels we analyzed show that the distinction between the virtual and the real world narrows, as the narratives range from intimate confession in letters and journals to tweets, notes and statuses, introducing verbal and structural experimental practices which involve shifting points of view.

  11. Thallium exists in opioid poisoned patients.

    Science.gov (United States)

    Ghaderi, Amir; Vahdati-Mashhadian, Naser; Oghabian, Zohreh; Moradi, Valiallah; Afshari, Reza; Mehrpour, Omid

    2015-08-01

    Thallium (Tl) is a toxic heavy metal that exists in nature. Tl poisoning (thallotoxicosis) may occur in opioid addicts. This study was designed to evaluate the frequency and level of urinary Tl in opioid abusers. In addition, clinical findings were evaluated. A total of 150 subjects were examined. Cases with a history of at least 3 years of abuse were admitted in the Imam Reza Hospital as the case group; 50 non-opioid abusers from the target population were included as the control group. Twenty-four hour urinary qualitative and quantitative Tl analyses were performed on both groups. Out of the 150 subjects, 128 (85 %) were negative for qualitative urinary Tl, followed by 5 % (trace), 7 % (1+), 2 % (2+), and 1 % (3+). Mean (standard error (SE), Min-Max) quantitative urinary Tl level was 14 μg/L (3.5 μg/L, 0-346 μg/L). Mean urinary Tl level in the case group was 21 μg/L (5 μg/L, 0-346 μg/L) and that in the controls was 1 μg/L (0.14 μg/L, 0-26 μg/L), which were significantly different (P = 0.001). The most frequent clinical findings were ataxia (86 %), sweating (81 %), and constipation (54 %). In all cases (n = 150), the mean (SE) value for cases with positive qualitative urinary Tl was 26.8 μg/L (0.9 μg/L) and that in the negative cases was 2.3 μg/L (0.2 μg/L), which were significantly different (P = 0.002). This study showed that long-term opioid abuse may lead to Tl exposure. In opioid abusers with the clinical manifestation of thallotoxicosis, urinary Tl should be determined.

  12. Seismic evaluation of existing nuclear facilities. Proceedings

    International Nuclear Information System (INIS)

    1995-01-01

    Programmes for re-evaluation and upgrading of safety of existing nuclear facilities are presently under way in a number of countries around the world. An important component of these programmes is the re-evaluation of the seismic safety through definition of new seismic parameters at the site and evaluation of seismic capacity of structures, equipment and distribution systems following updated information and criteria. The Seminar is intended to provide a forum for the exchange of information and discussion of the state-of-the-art on seismic safety of nuclear facilities in operation or under construction. Both analytical and experimental techniques for the evaluation of seismic capacity of structures, equipment and distribution systems are discussed. Full scale and field tests of structures and components using shaking tables, mechanical exciters, explosive and shock tests, and ambient vibrations are included in the seminar programme with emphasis on recent case histories. Presentations at the Seminar also include analytical techniques for the determination of dynamic properties of soil-structure systems from experiments as well as calibration of numerical models. Methods and criteria for seismic margin assessment based on experience data obtained from the behaviour of structures and components in real earthquakes are discussed. Guidelines for defining technical requirements for capacity re-evaluation (i.e. acceptable behaviour limits and design and implementation of structure and components upgrades are also presented and discussed. The following topics were covered during 7 sessions: earthquake experience and seismic re-evaluation; country experience in seismic re-evaluation programme; generic WWER studies; analytical methods for seismic capacity re-evaluation; experimental methods for seismic capacity re-evaluation; case studies

  13. Does GaH5 exist?

    Science.gov (United States)

    Speakman, Lucas D.; Turney, Justin M.; Schaefer, Henry F.

    2005-11-01

    The existence or nonexistence of GaH5 has been widely discussed [N. M. Mitzel, Angew. Chem. Int. Ed. 42, 3856 (2003)]. Seven possible structures for gallium pentahydride have been systematically investigated using ab initio electronic structure theory. Structures and vibrational frequencies have been determined employing self-consistent field, coupled cluster including all single and double excitations (CCSD), and CCSD with perturbative triples levels of theory, with at least three correlation-consistent polarized-valence-(cc-pVXZ and aug-cc-pVXZ) type basis sets. The X˜A'1 state for GaH5 is predicted to be weakly bound complex 1 between gallane and molecular hydrogen, with Cs symmetry. The dissociation energy corresponding to GaH5→GaH3+H2 is predicted to be De=2.05kcalmol-1. The H-H stretching fundamental is predicted to be v =4060cm-1, compared to the tentatively assigned experimental feature of Wang and Andrews [J. Phys. Chem. A 107, 11371 (2003)] at 4087cm-1. A second Cs structure 2 with nearly equal energy is predicted to be a transition state, corresponding to a 90° rotation of the H2 bond. Thus the rotation of the hydrogen molecule is essentially free. However, hydrogen scrambling through the C2v structure 3 seems unlikely, as the activation barrier for scrambling is at least 30kcalmol-1 higher in energy than that for the dissociation of GaH5 to GaH3 and H2. Two additional structures consisting of GaH3 with a dihydrogen bond perpendicular to gallane (C3v structure 4) and an in-plane dihydrogen bond [Cs(III) structure 5] were also examined. A C3v symmetry second-order saddle point has nearly the same energy as the GaH3+H2 dissociation limit, while the Cs(III) structure 5 is a transition structure to the C3v structure. The C4v structure 6 and the D3h structure 7 are much higher in energy than GaH3+H2 by 88 and 103kcalmol-1, respectively.

  14. PASSCLAIM - Synthesis and review of existing processes.

    Science.gov (United States)

    Richardson, David P; Affertsholt, Tage; Asp, Nils-Georg; Bruce, Ake; Grossklaus, Rolf; Howlett, John; Pannemans, Daphne; Ross, Richard; Verhagen, Hans; Viechtbauer, Volker

    2003-03-01

    Several approaches to the use of health claims on foods have been made around the world, and the common theme is that any health claim will require scientific validation and substantiation. There is also broad consensus that any regulatory framework should protect the consumer, promote fair trade and encourage innovation in the food industry.This paper is based on a critical evaluation of existing international approaches to the scientific substantiation of health claims, with a view to identifying common new ideas, definitions, best practice and a methodology to underpin current and future developments. There is a clear need to have uniform understanding, terminology and description of types of nutrition and health claims. Two broad categories were defined: Nutrition Claims, i. e. what the product contains, and Health Claims, i. e. relating to health, well-being and/or performance, including well-established nutrient function claims, enhanced function claims and disease risk reduction claims. Such health claims relate to what the food or food components does or do. The categories of health claims are closely and progressively related and are, in practice, part of a continuum. Provision is also made for "generic" or well-established, generally accepted claims and for "innovative" or "product-specific" claims. Special attention was paid to reflect the health-promoting properties of a food or food component in such a way as to facilitate the making of risk reduction claims outside the medical scope of the term prevention. The paper sets out basic principles and guidelines for communication of health claims and principles of nutritional safety. The main body of the work examines the process for the assessment of scientific support for health claims on food and emphasises an evidence-based approach consisting of: Identification of all relevant studies exploring the collection of evidence, data searches, the nature of the scientific evidence, sources of scientific data

  15. Imaging of surfaces and defects of crystals. Progress report, August 1, 1983-July 31, 1984

    International Nuclear Information System (INIS)

    Cowley, J.M.

    1984-01-01

    The current year has been one of major advances in our progress towards the development of techniques for the study of surfaces with high spatial resolution. The medium-energy (1-15keV) REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) has been rebuilt to the stage of showing better than 100A in the transmission mode in good vacuum and has been applied to the study of some surface reconstructions on silicon. These instruments include a 300 keV TEM-STEM analytical electron microscopy from Philips, to be converted for operation under ultra-high vacuum conditions by GATAN Inc. In this a resolution of better than 2.3A and various microanalytical techniques will be applied to surface studies. Also an ultra-high vacuum dedicated STEM instrument is being obtained and this will be modified for the combined application of high resolution STEM imaging, microdiffraction and microanalysis and the surface research techniques of AES, SAM, LEED, UPS and so on. Further observations on the interactions of small metal particles with ceramics have revealed a situation which has profound implications for electron-optical studies and for some possible technical applications of ceramic systems. It has been shown that the surface of MgO is modified by the presence of small amounts of various metals in such a way that it becomes highly sensitive to electron irradiation, undergoing vigorous reconstructions of the surface morphology and in some cases, becoming amorphous

  16. Scanning Tunneling Microscopy Studies of Surface Structures of Icosahedral Al-Cu-Fe Quasicrystals

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Tanhong [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Three papers are included in this dissertation. The first paper: ''Structural aspects of the fivefold quasicrystalline Al-Cu-Fe surface from STM and dynamical LEED studies'', is in press with ''Surface Science''. The second paper: ''An STM study of the atomic structure of the icosahedral Al-Cu-Fe fivefold surface'' is submitted to ''Physical Review B, Rapid Communication''. The third paper: ''Pseudomorphic starfish: arrangement of extrinsic metal atoms on a quasicrystalline substrate'' is submitted to ''Nature''. Following the third paper are general conclusions and appendices that document the published paper ''Structural aspects of the three-fold surface of icosahedral Al-Pd-Mn'' (appearing in volume 461, issue 1-3 of ''Surface Science'' on page L521-L527, 2000), the design as well as the specifications of the aluminum evaporator used in the aluminum deposition study in this dissertation, an extended discussion of the aluminum deposition on the quasicrystalline surface, and the STM database.

  17. Surface spectroscopic characterization of a model methane-activation catalyst

    International Nuclear Information System (INIS)

    Chen, J.G.; Weisel, M.D.; Hoffmann, F.M.; Hall, R.B.

    1992-01-01

    In an effort to understand the details concerning the alkali-promoted selectivity for the oxidative coupling of methane, the authors have carried out a detailed characterization of a model K/NiO/Ni(100) catalyst under well-controlled, ultrahigh vacuum conditions. The authors' systematic approach involved the following procedures: detailed investigation of the formation and structure of NiO on a clean Ni(100) surface; spectroscopic characterization of K-doped NiO by in situ deposition of potassium onto well-characterized NiO/Ni(100) substrate; and determination of the reactivities of NiO/Ni(100) and K/NiO/Ni(100) towards H 2 and CH 4 . In this paper, the authors will use the model K/NiO/Ni(100) system as an example to demonstrate that a detailed, complementary characterization of the model catalyst could best be achieved by using a combination of a variety of surface techniques: The methods of HREELS, LEED, XPS and AES could be applied to obtain properties on and near the surface regions; the technique of FYNES, being a photon-in/photon-out method could be utilized to investigate the bulk properties up to 2000 Angstrom below the surface; the method of FTIR using CO as a probing molecule is, on the other hand, sensitive only to the properties of the top-most surface layer. The result is to be presented in this paper will be mainly those obtained by using the two vibrational spectroscopies (HREELS and FTIR). Results from other surface techniques will also be discussed or presented when they provide additional information to the vibrational data

  18. A precariedade humana e a existência estilizada Human precariousness and stylized existence

    Directory of Open Access Journals (Sweden)

    Rita Paiva

    2013-04-01

    Full Text Available Este artigo tematiza o desamparo vivenciado pela consciência ante a ausência de bases sólidas para seus anseios de felicidade e para suas representações simbólicas. Com esse propósito, toma como objeto de reflexão um dos ensaios filosóficos de Albert Camus, O mito de Sísifo, equacionando a possibilidade de uma ética que estilize a vida, sem que se minimize a dolorosa precariedade da existência humana. Posteriormente, em diálogo com alguns textos de M. Foucault, a reflexão procura estabelecer os vínculos possíveis entre a ética camusiana e a ética como uma estética da existência, tal como pensada entre os gregos antigos.This article discusses the helplessness experienced by the consciousness vis-à-vis the absence of solid bases for its longings for happiness and for its symbolic representations. For this purpose, the object of reflection of the article is one of Albert Camus' philosophical essays, The Myth of Sisyphus, and we inquire into the possibility of an ethics that stylizes life without minimizing the painful precariousness of human existence. Making reference to certain texts by Foucault, we attempt to establish possible connections between Camus' ethics and an ethics of the aesthetics of existence as found in the thinkers of ancient Greece.

  19. Existence and non-existence of solutions for a singular problem with variable potentials

    Directory of Open Access Journals (Sweden)

    Kamel Saoudi

    2017-11-01

    Full Text Available The purpose of this article is to prove some existence and nonexistence theorems for the inhomogeneous singular Dirichlet problem $$ - \\Delta_p u = \\frac{\\lambda k(x}{u^\\delta}\\pm h(x u^q. $$ For proving our results we use the sub and super solution method, and monotonicity arguments.

  20. A high resolution photoemission study of surface core-level shifts in clean and oxygen-covered Ir(2 1 0) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gladys, M.J.; Ermanoski, I.; Jackson, G.; Quinton, J.S.; Rowe, J.E.; Madey, T.E. E-mail: madey@physics.rutgers.edu

    2004-04-01

    High resolution soft X-ray photoemission electron spectroscopy (SXPS), using synchrotron radiation, is employed to investigate 4f core-level features of four differently-prepared Ir(2 1 0) surfaces: clean planar, oxygen-covered planar, oxygen-induced faceted, and clean faceted surfaces. Surface and bulk peak identifications are supported by measurements at different photon energies (thus probing different electron escape depths) and variable emission angles. Iridium 4f{sub 7/2} photoemission spectra are fitted with Doniach-Sunjic lineshapes. The surface components are identified with core levels positioned at lower binding energies than the bulk components, in contrast to previous reports of binding energy inversion on Ir(1 0 0) (1x1) and (5x1) surfaces. For clean planar Ir(2 1 0) three surface Ir 4f{sub 7/2} features are observed with core-level shifts of -765, -529, and -281 meV, with respect to the bulk; these are associated with the first, second and third layers of atoms, respectively, for atomically rough Ir(2 1 0). Adsorption of oxygen onto the planar Ir(2 1 0) surface is found to cause a suppression and shift of the surface features to higher binding energies. Annealing at T{>=}600 K in oxygen produces a faceted surface as verified by low energy electron diffraction (LEED). A comparison of planar and faceted oxygen-covered surfaces reveals minor differences in the normal emission SXPS spectra, while grazing emission spectra exhibit differences. The SXPS spectrum of the clean, faceted Ir(2 1 0) exhibits small differences in comparison to the clean planar case, with surface features having binding energy shifts of -710, -450, and -230 meV.

  1. Black Hole Caught Zapping Galaxy into Existence?

    Science.gov (United States)

    2009-11-01

    , construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

  2. Existence and non-existence of solutions for a p(x-biharmonic problem

    Directory of Open Access Journals (Sweden)

    Ghasem A. Afrouzi

    2015-06-01

    Full Text Available In this article, we study the following problem with Navier boundary conditions $$\\displaylines{ \\Delta (|\\Delta u|^{p(x-2}\\Delta u+|u|^{p(x-2}u =\\lambda |u|^{q(x-2}u +\\mu|u|^{\\gamma(x-2}u\\quad \\text{in } \\Omega,\\cr u=\\Delta u=0 \\quad \\text{on } \\partial\\Omega. }$$ where $\\Omega$ is a bounded domain in $\\mathbb{R}^{N}$ with smooth boundary $\\partial \\Omega$, $N\\geq1$. $p(x,q(x$ and $\\gamma(x$ are continuous functions on $\\overline{\\Omega}$, $\\lambda$ and $\\mu$ are parameters. Using variational methods, we establish some existence and non-existence results of solutions for this problem.

  3. Some studies of lead and iron adsorption on the W(100) surface by field emission microscopy

    International Nuclear Information System (INIS)

    Jones, J.P.; Roberts, E.W.

    1978-01-01

    The behaviour of lead and iron adsorbed on the W(100) surface has been studied by probe hole field emission microscopy, field desorption, and by measurement of the total energy distribution (TED) of field-emitted electrons. Lead adsorbed at 300 K which reduces the work function of W(100) can be completely removed at 78 K by field desorption below 3.2 V A -1 and the resulting surface has both the work function and TED, which are characteristic of the clean plane. Condensation at 800 K followed by field desorption, results in a plane surface of work function 4.17 eV and an altered TED. This effect is attributed to the microfacetting, which is observed by LEED. The Swanson peak in the W(100) TED which is removed by submonolayer amounts of lead re-emerges at monolayer coverage when lead adopts the (1 X 1) structure. Such behaviour is consistent with the model proposed by Kar and Soven. A spectral peak observed when lead is adsorbed on the reconstructed W(100) surface is thought to derive for the atomic 1 D state. Adsorption of iron on a W(100) surface reduces phi considerably due to dipole formation and efficiently quenches the Swanson peak. (Auth.)

  4. 40 CFR 427.34 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Starch Binder) Subcategory § 427.34 Pretreatment standards for existing sources. Any existing source subject to...

  5. 40 CFR 427.44 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Paper (Elastomeric Binder) Subcategory § 427.44 Pretreatment standards for existing sources. Any existing source subject to...

  6. 40 CFR 417.84 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

  7. MR imaging of brain surface structures: Surface anatomy scanning

    International Nuclear Information System (INIS)

    Katada, K.; Koga, S.; Asahina, M.; Kanno, T.; Asahina, K.

    1987-01-01

    Preoperative evaluation of brain surface anatomy, including cortical sulci and veins, relative to cerebral and cerebellar lesions is an important subject for surgeons. Until now, no imaging modality existed that allowed direct visualization of brain surface anatomy. A new MR imaging technique (surface anatomy scanning) was developed to visualize brain surface structures. The technique uses a spin-echo pulse sequence with long repetition and echo times, thick sections and a surface coil. Cortical sulci, fissures, veins, and intracranial lesions were clearly identified with this technique. Initial clinical results indicate that surface anatomy scanning is useful for lesion localization and for detailed evaluation of cortical and subcortical lesions

  8. Molecular-level chemistry of model single-crystal oxide surfaces with model halogenated compounds

    Science.gov (United States)

    Adib, Kaveh

    Synchrotron-based X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption (TPD) and low energy electron diffraction (LEED) have been used to investigate, at a molecular level, the chemistry of different terminations of single crystal iron-oxide surfaces with probe molecules (CCl4 and D2O). Comparisons of the reactivity of these surfaces towards CCl4, indicate that the presence of an uncapped surface Fe cation (strong Lewis acid site) and an adjacent oxygen site capped by that cation can effect the C-Cl bond cleavage in CCl4, resulting in dissociatively adsorbed Cl-adatoms and carbon-containing fragments. If in addition to these sites, an uncapped surface oxygen (Lewis base) site is also available, the carbon-containing moiety can then move that site, coordinate itself with that uncapped oxygen, and stabilize itself. At a later step, the carbon-containing fragment may form a strong covalent bond with the uncapped oxygen and may even abstract that surface oxygen. On the other hand, if an uncapped oxygen is not available to stabilize the carbon-containing fragment, the surface coordination will not occur and upon the subsequent thermal annealing of the surface the Cl-adatoms and the carbon-containing fragments will recombine and desorb as CCl4. Finally, the presence of surface deuteroxyls blocking the strong Lewis acid and base sites of the reactive surface, passivates this surface. Such a deuteroxylated surface will be unreactive towards CCl 4. Such a molecular level understanding of the surface chemistry of metal-oxides will have applications in the areas of selective catalysis, including environmental catalysis, and chemical sensor technology.

  9. Does First Last: The Existence and Extent of First Mover Advantages on Spatial Networks

    OpenAIRE

    David Levinson; Feng Xie

    2007-01-01

    This paper examines the nature of first mover advantages on spatially-differentiated surface transportation networks. The literature on first mover advantages identifies a number of sources that explain their existence. However whether those sources exist on spatial networks, and how they play out with true capital immobility have been unanswered questions. By examining empirical examples including commuter rail and the Underground in London and roads in the Twin Cities of Minneapolis and St....

  10. Metal thin film growth on multimetallic surfaces: From quaternary metallic glass to binary crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Dapeng [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    The work presented in this thesis mainly focuses on the nucleation and growth of metal thin films on multimetallic surfaces. First, we have investigated the Ag film growth on a bulk metallic glass surface. Next, we have examined the coarsening and decay of bilayer Ag islands on NiAl(110) surface. Third, we have investigated the Ag film growth on NiAl(110) surface using low-energy electron diffraction (LEED). At last, we have reported our investigation on the epitaxial growth of Ni on NiAl(110) surface. Some general conclusions can be drawn as follows. First, Ag, a bulk-crystalline material, initially forms a disordered wetting layer up to 4-5 monolayers on Zr-Ni-Cu-Al metallic glass. Above this coverage, crystalline 3D clusters grow, in parallel with the flatter regions. The cluster density increases with decreasing temperature, indicating that the conditions of island nucleation are far-from-equilibrium. Within a simple model where clusters nucleate whenever two mobile Ag adatoms meet, the temperature-dependence of cluster density yields a (reasonable) upper limit for the value of the Ag diffusion barrier on top of the Ag wetting layer of 0.32 eV. Overall, this prototypical study suggests that it is possible to grow films of a bulk-crystalline metal that adopt the amorphous character of a glassy metal substrate, if film thickness is sufficiently low. Next, the first study of coarsening and decay of bilayer islands has been presented. The system was Ag on NiAl(110) in the temperature range from 185 K to 250 K. The coarsening behavior, has some similarities to that seen in the Ag(110) homoepitaxial system studied by Morgenstern and co-workers. At 185 K and 205 K, coarsening of Ag islands follows a Smoluchowski ripening pathway. At 205 K and 250 K, the terrace diffusion limited Ostwald ripening dominants. The experimental observed temperature for the transition from SR to OR is 205 K. The SR exhibits anisotropic island diffusion and the OR exhibits 1D decay of island

  11. 77 FR 62266 - Proposed Extension of Existing Information Collection; Daily Inspection of Surface Coal Mines...

    Science.gov (United States)

    2012-10-12

    ... conducting an on shift examination for hazardous conditions, mine operators better ensure a safe working environment for the miners and a reduction in accidents. II. Desired Focus of Comments The Mine Safety and... (30 CFR 77.1713) requires coal mine operators to conduct examinations of each active working area of...

  12. Existence and regularity of minimal surfaces on Riemannian manifolds (MN-27)

    CERN Document Server

    Pitts, Jon T

    2014-01-01

    Mathematical No/ex, 27 Originally published in 1981. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

  13. Erosion of surface and near surface disposal facilities

    International Nuclear Information System (INIS)

    1988-06-01

    A literature search was undertaken to identify existing data and analytical procedures regarding the processes of gully erosion. The applicability of the available information to the problems of gully erosion potential at surface and near surface disposal sites is evaluated. It is concluded that the existing knowledge regarding gully erosion is insufficient to develop procedures to ensure the long-term stability of disposal sites. Recommendations for further research are presented. 46 refs

  14. Structure of the c(2x2) Mn/Ni(001) surface alloy by quantitative photoelectron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Denlinger, J.; Chen, X. [Univ. of Wisconsin, Milwaukee, WI (United States)] [and others

    1997-04-01

    Surface alloys are two-dimensional metallic systems that can have structures that are unique to the surface, and have no counterpart in the bulk binary phase diagram. A very unusual structure was reported for the Mn-Ni system, based on a quantitative LEED structure determination, which showed that the Mn atoms were displaced out of the surface by a substantial amount. This displacement was attributed to a large magnetic moment on the Mn atoms. The structure of the Mn-Ni surface alloy was proposed to be based on a bulk termination model. Magnetic measurements on the Mn-Ni surface alloys, however, showed conclusively that the magnetic structure of these surface alloys is completely different from the bulk alloy analogs. For example, bulk MnNi is an antiferromagnet, whereas the surface alloy is ferromagnetic. This suggests that the proposed structure based on bulk termination, may not be correct. X-ray Photoelectron Diffraction (XPD) techniques were used to investigate this structure, using both a comparison to multiple scattering calculations and photoelectron holography. In this article the authors present some of the results from the quantitative analysis of individual diffraction patterns by comparison to theory.

  15. Concavity Theorems for Energy Surfaces

    OpenAIRE

    Giraud, B. G.; Karataglidis, S.

    2011-01-01

    Concavity properties prevent the existence of significant landscapes in energy surfaces obtained by strict constrained energy minimizations. The inherent contradiction is due to fluctuations of collective coordinates. A solution to those fluctuations is given.

  16. Spectroscopic studies of organometallic compounds on single crystal metal surfaces: Surface acetylides of silver (110)

    Science.gov (United States)

    Madix, Robert J.

    The nature of compounds formed by the reaction of organic molecules with metal surfaces can be studied with a battery of analytical methods based on both physicals and chemical understanding. In this paper the application of UPS, XPS, LEED and EELS as well as temperature programmed reaction spectroscopy (TPRS) and chemical titration methods to the characterization of surface complexes is discussed. Particular emphasis is given to the reaction of acetylene with a single crystal surface of silver, Ag(110). Previous work has shown that this surface, when clean, is unreactive to hydrocarbons, alcohols and carboxylic acids under ultra high vacuum conditions. Preadsorption of oxygen, however, renders the surface reactive, and a wide variety of organometallic surface compounds can be formed. As expected then, no stable adsorption state and no reaction was observed with clean Ag(110) following room temperature exposure to acetylene. Following exposure at 150 K, however, a weekly bound chemisorption state was observed to desorb at 195 K, indicating a binding energy to the surface of approximately 12 kcal/gmole. Reaction with preadsorbed oxygen gave water formulation upon dosing and produced surface intermediates which yeilded two acetylene desorption states at 195 and 175 K. Heating above 300 K to completely desorb the higher temperature state produced new, well-defined LEED Features due to residual surface carbon which disappeared when the surface was heated above 550 K. Clearly, there were distinc changes in the nature of the absorbed layer at 195, 300 and 550 K. These changes were reflected in XPS. For the weakly chemisorbed acetylene a large C(ls) peak at 285.6 eV with a small, broad, indistinc shoulder at higher binding energy (288.2) was observed. The spectrum of the species following acetylene desorption at 275 K, however, showed the formulation of a large C(ls) peak at 283.6 eV in addition to peaks characteristics of the weakly chemisorbed state. This result

  17. Graphitization of boron predeposited 6H-SiC(0 0 0 1) surface

    International Nuclear Information System (INIS)

    Okonogi, Yuta; Aoki, Yuki; Hirayama, Hiroyuki

    2012-01-01

    Highlights: ► We have tried to dope the B atoms into epitaxial graphene during the graphene growing process. ► The B induced changes in the surface were characterized by low-energy electron microscopy, auger electron spectroscopy, atomic force microscopy, and scanning tunneling icroscopy. ► No obvious B atoms doping evidence into the graphene was observed. - Abstract: We examined the substitutional doping of B atoms into epitaxial graphene on the SiC(0 0 0 1) surface. B atoms were deposited on the SiC(0 0 0 1) surface in advance of the growth of graphene. The B-induced changes in the surface morphology and chemical composition were characterized at the four thermal treatment stages in the growth of graphene (at 1120, 1370, 1520, and 1770 K) by low-energy electron diffraction (LEED), auger electron spectroscopy (AES), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). The B atoms were found to hinder the formation of a spatially uniform graphene layer. However, local deformation of the graphene lattice, which should be observed if B atoms are successfully doped substitutionally, was not observed in STM.

  18. Dynamic Equilibrium Mechanism for Surface Nanobubble Stabilization

    NARCIS (Netherlands)

    Brenner, Michael P.; Lohse, Detlef

    2008-01-01

    Recent experiments have convincingly demonstrated the existence of surface nanobubbles on submerged hydrophobic surfaces. However, classical theory dictates that small gaseous bubbles quickly dissolve because their large Laplace pressure causes a diffusive outflux of gas. Here we suggest that the

  19. Do superheavy elements imply the existence of black holes

    International Nuclear Information System (INIS)

    Pringle, J.E.; Dearborn, D.S.P.; Fabian, A.C.

    1976-01-01

    Some comments are offered on the question of where superheavy elements, such as elements 116, 124 and 126, are likely to have been formed. Most of these elements are thought to have been produced under conditions of explosive nucleosynthesis by what is known as the 'r-process', and particularly in conventional supernova explosions, but it is stated that the ability of the r-process to produce superheavy elements is very uncertain, and the conditions necessary for synthesis of these elements are difficult to realise in astrophysical situations. It is thought that superheavy elements exist in the outer layers of neutron stars, and ideal conditions for the production of superheavy nuclei, such as high neutron flux and rapid β decays, occur in the disruption of a neutron star. Such disruption is possible in two ways, both of which involve a black hole. It is likely that a neutron star is disrupted when it accretes sufficient material for its mass to exceed the maximum mass for stability, and it then has no alternative but to collapse to form a black hole and it seems possible that some of the outer layers are thrown off during the process. It is thus argued that the most likely site for the production of superheavy elements is in the surface layers of a neutron star, and the most plausible means by which these layers can be returned to the interstellar medium involves the intervention or formation of a black hole. (U.K.)

  20. Minimal surfaces

    CERN Document Server

    Dierkes, Ulrich; Sauvigny, Friedrich; Jakob, Ruben; Kuster, Albrecht

    2010-01-01

    Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently

  1. Non-existence of natural states for Abelian Chern-Simons theory

    Science.gov (United States)

    Dappiaggi, Claudio; Murro, Simone; Schenkel, Alexander

    2017-06-01

    We give an elementary proof that Abelian Chern-Simons theory, described as a functor from oriented surfaces to C∗-algebras, does not admit a natural state. Non-existence of natural states is thus not only a phenomenon of quantum field theories on Lorentzian manifolds, but also of topological quantum field theories formulated in the algebraic approach.

  2. 75 FR 79030 - Proposed Extension of Existing Information Collection; Training Plans and Records of Training

    Science.gov (United States)

    2010-12-17

    ... Extension of Existing Information Collection; Training Plans and Records of Training AGENCY: Mine Safety and... extension of the information collection for Training Plans and Records of Training, 30 CFR 48.3, 48.9, 48.23... require training plans for underground and surface mines, respectively. The standards are intended to...

  3. Rumble surfaces

    CSIR Research Space (South Africa)

    National Institute for Transport and Road

    1977-01-01

    Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...

  4. Surface thermodynamics

    International Nuclear Information System (INIS)

    Garcia-Moliner, F.

    1975-01-01

    Basic thermodynamics of a system consisting of two bulk phases with an interface. Solid surfaces: general. Discussion of experimental data on surface tension and related concepts. Adsorption thermodynamics in the Gibbsian scheme. Adsorption on inert solid adsorbents. Systems with electrical charges: chemistry and thermodynamics of imperfect crystals. Thermodynamics of charged surfaces. Simple models of charge transfer chemisorption. Adsorption heat and related concepts. Surface phase transitions

  5. Trapped surfaces in spherical stars

    International Nuclear Information System (INIS)

    Bizon, P.; Malec, E.; O'Murchadha, N.

    1988-01-01

    We give necessary and sufficient conditions for the existence of trapped surfaces in spherically symmetric spacetimes. These conditions show that the formation of trapped surfaces depends on both the degree of concentration and the average flow of the matter. The result can be considered as a partial validation of the cosmic-censorship hypothesis

  6. 75 FR 45013 - Pre-Existing Condition Insurance Plan Program

    Science.gov (United States)

    2010-07-30

    ... Department of Homeland Security's U.S. Citizenship and Immigration Services (USCIS) Systematic Alien... pre-existing condition based on evidence of the existence or history of certain medical or health...

  7. EXISTENCE OF POSITIVE SOLUTIONS FOR AN ELASTIC CURVED BEAM EQUATION

    Directory of Open Access Journals (Sweden)

    Béla Kovacs

    2017-06-01

    Full Text Available This paper investigates the existence of positive solutions for a sixth-order differential equations. By using the Leggett-Williams fixed point theorem we give some new existence results.

  8. 40 CFR 406.34 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.34 Section 406.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... § 406.34 Pretreatment standards for existing sources. Any existing source subject to this subpart that...

  9. 40 CFR 406.44 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.44 Section 406.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... § 406.44 Pretreatment standards for existing sources. Any existing source subject to this subpart that...

  10. Existence of pareto equilibria for multiobjective games without compactness

    OpenAIRE

    Shiraishi, Yuya; Kuroiwa, Daishi

    2013-01-01

    In this paper, we investigate the existence of Pareto and weak Pareto equilibria for multiobjective games without compactness. By employing an existence theorem of Pareto equilibria due to Yu and Yuan([10]), several existence theorems of Pareto and weak Pareto equilibria for the multiobjective games are established in a similar way to Flores-B´azan.

  11. On real structures on rigid surfaces

    International Nuclear Information System (INIS)

    Kulikov, Vik S; Kharlamov, V M

    2002-01-01

    We construct examples of rigid surfaces (that is, surfaces whose deformation class consists of a unique surface) with a particular behaviour with respect to real structures. In one example the surface has no real structure. In another it has a unique real structure, which is not maximal with respect to the Smith-Thom inequality. These examples give negative answers to the following problems: the existence of real surfaces in each deformation class of complex surfaces, and the existence of maximal real surfaces in every complex deformation class that contains real surfaces. Moreover, we prove that there are no real surfaces among surfaces of general type with p g =q=0 and K 2 =9. These surfaces also provide new counterexamples to the 'Dif = Def' problem

  12. On real structures on rigid surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kulikov, Vik S [Steklov Mathematical Institute, Russian Academy of Sciences (Russian Federation); Kharlamov, V M [Institut de Recherche Matematique Avanee Universite Louis Pasteur et CNRS 7 rue Rene Descartes (France)

    2002-02-28

    We construct examples of rigid surfaces (that is, surfaces whose deformation class consists of a unique surface) with a particular behaviour with respect to real structures. In one example the surface has no real structure. In another it has a unique real structure, which is not maximal with respect to the Smith-Thom inequality. These examples give negative answers to the following problems: the existence of real surfaces in each deformation class of complex surfaces, and the existence of maximal real surfaces in every complex deformation class that contains real surfaces. Moreover, we prove that there are no real surfaces among surfaces of general type with p{sub g}=q=0 and K{sup 2}=9. These surfaces also provide new counterexamples to the 'Dif = Def' problem.

  13. Free Surface Properties of III-V Compound Semiconductor Surfaces.

    Science.gov (United States)

    1980-06-01

    selvage. Most important is the fact that atomic displacements also occur up to two layers into the substrate in the IaSb (ll0) selvage, presumably because of...result is that the interaction is of a disordering nature. 1 2,1 3 We took LEED measurements for a very large range of exposure to molecular oxygen (103...which the Al replaces the Ga. Arguments in favor of this reaction are given by measured photoemission peak shifts: 1 8󈧗 the Ga 3-d core level shifts

  14. Aan der Waals terminated silicon(111) surfaces and interfaces. Preparation, morphology, and electronic properties

    International Nuclear Information System (INIS)

    Fritsche, R.

    2004-01-01

    The aim of this thesis is the implementation of the concept of the quasi-van der Waals epitaxy as a new perspective for the integration of reactive and lattice-defect fitted materials into the silicon technology. The experimental characterization of this approach pursues in two subsequent sections. First the chemical and electronic passivation of a three-dimensional substrate (silicon) is studied by means of an ultrathin buffer layer from the material class of the layered-lattice chalcogenides (GaSe). The substrate surface (Si(111):GaSe) modified in this way possesses an inert van der Waals surface and serves in the following as base for the deposition of the against the non-passivated substrate really reactive and lattice-defect fitted materials (II-VI-compound semiconductors and metals) The characterization of the electronic and chemical properties of the surfaces and interfaces pursues with highly resolved photoelectron spectroscopy (SXPS). The results are supplemented by the characterization of the morphology by the diffraction of low-energy electrons (LEED) and the scanning tunnel microscopy (STM)

  15. Scanning Tunneling Microscopy Study of Carbon Tetrachloride Adsorption and Degradation on a Natural a-Fe2O3(0001) Surface in Ultrahigh Vacuum

    Science.gov (United States)

    Taeg Rim, Kwang; Fitts, Jeffrey; Adib, Kaveh; Camillone, Nicholas, III; Schlosser, Peter; Osgood, Richard, Jr.; Flynn, George; Joyce, Stephen

    2001-03-01

    Scanning tunneling microscopy and low energy electron diffraction have been used to study a natural a-Fe2O3(0001) surface and the adsorption and degradation of carbon tetrachloride on the reduced Fe3O4(111) terminated surface. A natural a-Fe2O3 (0001) surface was prepared by repeated cycles of Ar+ ion sputtering and annealing in vacuum or in O2 at 850 K. STM images and a LEED pattern indicate that an Fe3O4(111) terminated surface and a bi-phase can be formed depending on annealing conditions. The Fe3O4(111) terminated surface was dosed with CCl4 at room temperature, and flashed up to 590 K and 850 K. STM images show adsorbates on the surface at room temperature and the degradation products of CCl4 are isolated on the surface as the flashing temperature increases up to 850 K. Results from a companion temperature programmed desorption investigation are used in conjunction with the STM images to propose site specific reactions of CCl4 on the Fe3O4(111) terminated surface.

  16. Plasma-surface interactions

    International Nuclear Information System (INIS)

    Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J

    2008-01-01

    Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

  17. Plasma-surface interactions

    Energy Technology Data Exchange (ETDEWEB)

    Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J [Department of Electrical Engineering, University of Texas at Dallas (United States)], E-mail: goeckner@utdallas.edu

    2008-10-01

    Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

  18. Method and refrigerants for replacing existing refrigerants in centrifugal compressors

    International Nuclear Information System (INIS)

    Kopko, W.L.

    1991-01-01

    This patent describes a method for replacing an existing refrigerant in a centrifugal compressor. It comprises selecting a desired impeller Mach number for the centrifugal compressor; selecting a base refrigerant constituent; combining at least one additive refrigerant constituent with the base refrigerant constituent to form a replacement refrigerant having at least one physical or chemical property different from the existing refrigerant and substantially providing the desired impeller Mach number in the centrifugal compressor; and replacing the existing refrigerant with the replacement refrigerant

  19. Magnetic nesting and co-existence of ferromagnetism and superconductivity

    International Nuclear Information System (INIS)

    Elesin, V.F.; Kapaev, V.V.; Kopaev, Yu.V.

    2004-01-01

    In the case of providing for the magnetic nesting conditions of the electron spin dispersion law the co-existence of ferromagnetism and superconductivity is possible by any high magnetization. The co-existence of ferromagnetism and superconductivity in the layered cuprate compounds of the RuSr 2 GdCu 2 O 8 -type is explained on this basis, wherein due to the nonstrict provision of the magnetic nesting condition there exists the finite but sufficiently high critical magnetization [ru

  20. The global existence problem and cosmic censorship in general relativity

    International Nuclear Information System (INIS)

    Moncrief, V.; Eardley, D.M.

    1981-01-01

    Two global existence conjectures for the Einstein equations are formulated and their relevance to the cosmic censorship conjecture discussed. It is argued that the reformulation of the cosmic censorship conjecture as a global existence problem renders it more amenable to direct analytical attack. To demonstrate the facility of this approach the cosmological version of the global existence conjecture is proved for the Gowdy spacetimes on T 3 X R. (author)

  1. Surface mining

    Science.gov (United States)

    Robert Leopold; Bruce Rowland; Reed Stalder

    1979-01-01

    The surface mining process consists of four phases: (1) exploration; (2) development; (3) production; and (4) reclamation. A variety of surface mining methods has been developed, including strip mining, auger, area strip, open pit, dredging, and hydraulic. Sound planning and design techniques are essential to implement alternatives to meet the myriad of laws,...

  2. Superhydrophobic surfaces

    Science.gov (United States)

    Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza

    2015-03-24

    Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.

  3. Surface characterization

    Science.gov (United States)

    Mandla A. Tshabalala

    2005-01-01

    Surface properties of wood play an important role when wood is used or processed into different commodities such as siding, joinery, textiles, paper, sorption media or wood composites. Thus, for example, the quality and durability of a wood coating are determined by the surface properties of the wood and the coating. The same is true for wood composites, as the...

  4. Influence of Sn on the optical anisotropy of single-domain Si(001)

    International Nuclear Information System (INIS)

    Astropekakis, A.; Power, J.R.; Fleischer, K.; Esser, N.; Richter, W.; Galata, S.; Papadimitriou, D.

    2001-01-01

    We apply reflectance anisotropy spectroscopy (RAS) and low-energy electron diffraction (LEED) to the study of Sn deposited on a single-domain vicinal Si(001) sample. Large variations in RAS are recorded when up to 5 monolayers (ML) of Sn is deposited on the Si substrate at room temperature. We observe (2x2) and (1x1) LEED patterns for the 0.5-ML and 1.0-ML Sn covered surfaces, respectively. The (1x1) LEED pattern exists beyond this coverage and up to 5.0-ML deposition. Even though a (1x1) LEED pattern is observed upon deposition of 1.5 ML, surprisingly, a significant optical anisotropy is observed. After annealing to 570 degree sign C for 2 min, we observe a progression of LEED pattern changes from c(4x4)→(6x2)→c(8x4)→(5x1) with increased Sn coverage up to 1.5 ML. Similar RAS line shapes are obtained for all reconstructions produced through annealing with the exception of the (5x1). For the (5x1) phase, a significant anisotropy appears in the region of 1.8 eV. Similarities in the RAS line shape for both the (5x1) phase and that obtained after deposition of 1.5 ML of Sn at room temperature may indicate a RAS sensitivity to Sn dimer orientation within the uppermost layer

  5. Rare earth silicide nanowires on silicon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Martina

    2008-11-10

    The growth, structure and electronic properties of rare earth silicide nanowires are investigated on planar and vicinal Si(001) und Si(111) surfaces with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy (ARPES). On all surfaces investigated within this work hexagonal disilicides are grown epitaxially with a lattice mismatch of -2.55% up to +0.83% along the hexagonal a-axis. Along the hexagonal c-axis the lattice mismatch is essentially larger with 6.5%. On the Si(001)2 x 1 surface two types of nanowires are grown epitaxially. The socalled broad wires show a one-dimensional metallic valence band structure with states crossing the Fermi level. Along the nanowires two strongly dispersing states at the anti J point and a strongly dispersing state at the anti {gamma} point can be observed. Along the thin nanowires dispersing states could not be observed. Merely in the direction perpendicular to the wires an intensity variation could be observed, which corresponds to the observed spacial structure of the thin nanowires. The electronic properties of the broad erbium silicide nanowires are very similar to the broad dysprosium silicide nanowires. The electronic properties of the DySi{sub 2}-monolayer and the Dy{sub 3}Si{sub 5}-multilayer on the Si(111) surface are investigated in comparison to the known ErSi{sub 2}/Si(111) and Er{sub 3}Si{sub 5}/Si(111) system. The positions and the energetic locations of the observed band in the surface Brillouin zone will be confirmed for dysprosium. The shape of the electron pockets in the (vector)k {sub parallel} space is elliptical at the anti M points, while the hole pocket at the anti {gamma} point is showing a hexagonal symmetry. On the Si(557) surface the structural and electronic properties depend strongly on the different preparation conditions likewise, in particular on the rare earth coverage. At submonolayer coverage the thin nanowires grow in wide areas

  6. 40 CFR 407.74 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Vegetables Subcategory § 407.74 Pretreatment standards for existing sources...

  7. INFORMATION SECURITY RISK ASSESSMENT USING EXISTING LEGAL AND METHODOLOGICAL BASE

    Directory of Open Access Journals (Sweden)

    A. I. Trubei

    2015-01-01

    Full Text Available The article provides a survey of the existing regulatory framework for information security riskmanagement. Practical methods for information security risk and vulnerability assessment are proposed.

  8. Expandable External Payload Carrier for Existing Launch Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Numerous existing launch vehicles have excess performance that is not being optimized. By taking advantage of excess, unused, performance, additional NASA...

  9. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    International Nuclear Information System (INIS)

    Zhao, W.; Steidl, M.; Paszuk, A.; Brückner, S.; Dobrich, A.; Supplie, O.; Kleinschmidt, P.; Hannappel, T.

    2017-01-01

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H_2. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H_2-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H_2 ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  10. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W.; Steidl, M.; Paszuk, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Brückner, S. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Dobrich, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Supplie, O. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Kleinschmidt, P. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Hannappel, T., E-mail: thomas.hannappel@tu-ilmenau.de [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany)

    2017-01-15

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H{sub 2}. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H{sub 2}-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H{sub 2} ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  11. How old is surface science?

    International Nuclear Information System (INIS)

    Paparazzo, E.

    2004-01-01

    Philosophical and literary testimonies from the Classical World (5th century B.C. to 3rd century A.D.) involving solid surfaces are reviewed. Plato thought the surface to be a real entity, whereas Aristotle considered it to possess an unqualified existence, i.e. not to be a substance, but just an accidental entity. The Old Stoics asserted that surfaces do not possess any physical existence, although the Stoic philosopher Posidonius--apparently the only exception in his school--held them to exist both in thought and reality. While both the Atomists and the Epicureans were very little interested in them, the Sceptic philosopher Sextus Empiricus considered surfaces to be the limits of a body, although he maintained that both the view that they are corporeal or the view that they are incorporeal present unsurmountable difficulties. Among Roman authors, the testimony from Pliny the Elder is mostly concerned with metallic surfaces, chemical change occurring there, and surface treatments used in antiquity. Besides the philosophical motivations, the implications of the testimonies are discussed in the light of surface science. The purely geometrical surface of Plato is found to compare favorably to single-crystal surface, Posidonius' 'corporeal' surface is best likened to an air-oxidized, or otherwise ambient-modified surface, and ancient accounts on mixture are compared to XPS results obtained in adhesion studies of enameled steels. I argue that the long-standing dominance of Aristotle's view from antiquity onwards may have had a part in delaying theoretical speculation into solid surfaces

  12. Electron Spectroscopy Studies of Iron, Iron Sulfides and Supported Iron Surfaces: Chemisorption of Simple Gases.

    Science.gov (United States)

    Lee, Yiu Chung

    EELS was used to investigate the chemisorption of oxygen and carbon on iron. The EELS spectra of oxidized iron show characteristic features with strong enhancement of the interband transitions involving the Fe 3d band (4.6 and 7.5 eV) and moderate enhancement of the M(,2,3) transition doublet (54.4 and 58.2 eV). The changes in the electron energy loss structures with an overlayer of graphitic or carbidic carbon were investigated. The adsorption and growth of iron on Ni(100) has been studied using the combined techniques of LEED and EELS. Initially iron grows by a layer-by-layer mechanism for the first few layers. High iron coverages result in the observation of complex LEED patterns with satellites around the main (1 x 1) diffraction sports. This is due to the formation of b.c.c. Fe(110) crystallites arranged in domains with different orientations. EELS studies show the presence of three stages in the growth of iron on Ni(100): low-coverage, film-like and bulk-like. Auger and EELS were used to study the iron sulfide (FeS(,2), Fe(,7)S(,8) and FeS) surfaces. A characteristic M(,2,3) VV Auger doublet with a separation of 5.0 eV was observed on the sulfides. An assignment of the electron energy loss peaks was made based on the energy dependence of the loss peaks and previous photoemission results. The effect of argon ion bombardment was studied. Peaks with strong iron and sulfur character were observed. Heating the damaged sulfides results in reconstruction of the sulfide surfaces. The reactions of the sulfides with simple gases, such as H(,2), CO, CH(,4), C(,2)H(,4), NH(,3) and O(,2) were also studied. Using XPS, the chemisorption of SO(,2) on CaO(100) has been studied. The chemical state of sulfur has been identified as that of sulfate. The kinetics of SO(,2) chemisorption on CaO are discussed. The binding states of Fe and Na on CaO were determined to be Fe('2+) and Na('+) respectively. At low Fe or Na coverages (< 0.5 ML), there is a large increase in the rate of

  13. Tachyons imply the existence of a privileged frame

    Energy Technology Data Exchange (ETDEWEB)

    Sjoedin, T.; Heylighen, F.

    1985-12-16

    It is shown that the existence of faster-than-light signals (tachyons) would imply the existence (and detectability) of a privileged inertial frame and that one can avoid all problems with reversed-time order only by using absolute synchronization instead of the standard one. The connection between these results and the EPR-paradox is discussed.

  14. Safety assessment of existing highway bridges and viaducts

    NARCIS (Netherlands)

    Maljaars, J.; Steenbergen, R.; Abspoel, L.; Kolstein, M.H.

    2012-01-01

    The assessment of the structural safety of existing br idges and viaducts becomes increasingly important in many countries owing to an increase in traffic loads. Most existing standards, however, are developed for the design of new structures. For this reason, an assessment method for determining

  15. Neural Network for Optimization of Existing Control Systems

    DEFF Research Database (Denmark)

    Madsen, Per Printz

    1995-01-01

    The purpose of this paper is to develop methods to use Neural Network based Controllers (NNC) as an optimization tool for existing control systems.......The purpose of this paper is to develop methods to use Neural Network based Controllers (NNC) as an optimization tool for existing control systems....

  16. The Relationship among Localization Skill, Existence Constancy and Object Permanence.

    Science.gov (United States)

    Townes-Rosenwein, Linda

    Two component skills of object permanence were studied: existence constancy -- the infants' ability to expect that an object continues to exist after it is hidden, and localization skill -- infants' ability to search in the correct place for a hidden object. Contradictions within the literature may occur because of task lability caused by failure…

  17. 40 CFR 63.312 - Existing regulations and requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Existing regulations and requirements. 63.312 Section 63.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... National Emission Standards for Coke Oven Batteries § 63.312 Existing regulations and requirements. (a) The...

  18. Existence of solutions of nonlinear integrodifferential equations of ...

    Indian Academy of Sciences (India)

    The results are obtained by using semigroup theory and the Schauder fixed point ... The problem of existence of solutions of evolution equations with nonlocal ... we assume that there exists an operator E on DЕEЖИX given by the formula.

  19. The solution of location problems with certain existing facility structures

    DEFF Research Database (Denmark)

    Juel, Henrik; Love, Robert F.

    1983-01-01

    It is known that in the Euclidean distance case, the optimal minisum location of a new facility in relation to four existing facilities is at the intersection of the two lines joining two pairs of the facilities. The authors extend this concept to minisum problems having any even number of existing...... facilities and characterized by generalized distance norms...

  20. Existence of the Stark-Wannier quantum resonances

    Energy Technology Data Exchange (ETDEWEB)

    Sacchetti, Andrea, E-mail: andrea.sacchetti@unimore.it [Department of Physics, Computer Sciences and Mathematics, University of Modena e Reggio Emilia, Modena (Italy)

    2014-12-15

    In this paper, we prove the existence of the Stark-Wannier quantum resonances for one-dimensional Schrödinger operators with smooth periodic potential and small external homogeneous electric field. Such a result extends the existence result previously obtained in the case of periodic potentials with a finite number of open gaps.

  1. Does Absolute Synonymy exist in Owere-Igbo? | Omego | AFRREV ...

    African Journals Online (AJOL)

    Among Igbo linguistic researchers, determining whether absolute synonymy exists in Owere–Igbo, a dialect of the Igbo language predominantly spoken by the people of Owerri, Imo State, Nigeria, has become a thorny issue. While some linguistic scholars strive to establish that absolute synonymy exists in the lexical ...

  2. Existence and attractors of solutions for nonlinear parabolic systems

    Directory of Open Access Journals (Sweden)

    Hamid El Ouardi

    2001-01-01

    Full Text Available We prove existence and asymptotic behaviour results for weak solutions of a mixed problem (S. We also obtain the existence of the global attractor and the regularity for this attractor in $\\left[H^{2}(\\Omega \\right] ^{2}$ and we derive estimates of its Haussdorf and fractal dimensions.

  3. Remarks on the existence of non equilibrium dynamics

    International Nuclear Information System (INIS)

    Marchioro, C.; Pellegrinotti, A.; Pulvirenti, M.

    1981-01-01

    The authors give an existence theorem for the dynamics of an infinite system of anharmonic oscillators. They obtain another proof of the existence of the dynamics in the case of one-dimensional system of infinitely many particles interacting via a bounded potential. The case of very singular potential is also solved. (Auth.)

  4. Global existence of small solutions to semilinear Schroedinger equations

    International Nuclear Information System (INIS)

    Chihara, Hiroyuki

    1996-01-01

    We present global existence theorem for semilinear Schrodinger equations. In general, Schrodinger-type equations do not admit the classical energy estimates. To avoid this difficulty, we use S. Doi's method for linear Schrodinger-type equations. Combining his method and L p -L q estimates, we prove the global existence of solutions with small initial data

  5. 49 CFR 223.15 - Requirements for existing passenger cars.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Requirements for existing passenger cars. 223.15... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SAFETY GLAZING STANDARDS-LOCOMOTIVES, PASSENGER CARS AND CABOOSES Specific Requirements § 223.15 Requirements for existing passenger cars. (a) Passenger cars built or...

  6. Existing knowledge related to mainstreaming IKS into Educational ...

    African Journals Online (AJOL)

    The study aimed at determining existing knowledge related to mainstreaming of IKS into education system. The qualitative research methodology was appropriate for this study to explore and describe the mainstreaming of IKS into the existing education system. The study included 10 school teachers (5male and 5 females) ...

  7. An existence result of energy minimizer maps between Riemannian polyhedra

    International Nuclear Information System (INIS)

    Bouziane, T.

    2004-06-01

    In this paper, we prove the existence of energy minimizers in each free homotopy class of maps between polyhedra with target space without focal points. Our proof involves a careful study of some geometric properties of Riemannian polyhedra without focal points. Among other things, we show that on the relevant polyhedra, there exists a convex supporting function. (author)

  8. 30 CFR 784.12 - Operation plan: Existing structures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Operation plan: Existing structures. 784.12... PLAN § 784.12 Operation plan: Existing structures. (a) Each application shall contain a description of... and reclamation operation. The description shall include: (1) Location; (2) Plans of the structure...

  9. 30 CFR 780.12 - Operation plan: Existing structures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Operation plan: Existing structures. 780.12... PLAN § 780.12 Operation plan: Existing structures. (a) Each application shall contain a description of... and reclamation operation. The description shall include— (1) Location; (2) Plans of the structure...

  10. Model surface studies of metal oxides: Adsorption of water and methanol on ultrathin MgO films on Mo(100)

    International Nuclear Information System (INIS)

    Wu, M.; Estrada, C.A.; Corneille, J.S.; Goodman, D.W.

    1992-01-01

    Model surface studies of magnesium oxide have been carried out using surface sensitive techniques. Ultrathin MgO films have been synthesized under ultrahigh vacuum (UHV) conditions by thermally evaporating Mg onto Mo(100) in the presence of oxygen. Low-energy electron diffraction (LEED) studies indicate that the MgO films grow epitaxially with the (100) face of MgO oriented parallel to Mo(100). The MgO films, prepared under optimum synthesis conditions, have essentially one-to-one stoichiometry, are nearly free from pointlike surface defects, and have properties essentially identical to those of bulk, single-crystal MgO. Adsorption of water and methanol onto the MgO films has been studied using high-resolution electron energy-loss spectroscopy (HREELS) and temperature programmed desorption (TPD). In order to circumvent the difficulty associated with intense multiple surface optical phonon (Fuchs--Kliewer modes) losses, a new approach to acquisition of HREELS data has been demonstrated. This new approach enables the direct observation of weak loss features due to excitation of the adsorbates without serious interference from multiple phonon losses. Our HREELS studies show that water and methanol undergo heterolytic dissociation, leading to the formation of hydroxyl and methoxy species, respectively

  11. Kierkegaard e a existência possível

    Directory of Open Access Journals (Sweden)

    Roberto S. Kahlmeyer-Mertens

    2013-05-01

    Full Text Available Resumo: A relação entre a existência e a possibilidade, objeto deste artigo, merece especial atenção quando se trata de Kierkegaard. Isso porque, estes dois conceitos ocupam papéis primordiais na filosofia do autor, constituindo, justamente, o ponto a partir do qual o pensador se distancia criticamente da tradição filosófica. Caracterizar sumariamente os conceitos de existência e possibilidade na filosofia de Kierkegaard, bem como ambientar o filósofo em sua época como um pensador da existência, para além do rótulo de “existencialista”, são nossos presentes objetivos.   Palavras-chave: Kierkegaard, filosofia da existência, existência, possibilidade

  12. Adhesion, friction, wear, and lubrication research by modern surface science techniques.

    Science.gov (United States)

    Keller, D. V., Jr.

    1972-01-01

    The field of surface science has undergone intense revitalization with the introduction of low-energy electron diffraction, Auger electron spectroscopy, ellipsometry, and other surface analytical techniques which have been sophisticated within the last decade. These developments have permitted submono- and monolayer structure analysis as well as chemical identification and quantitative analysis. The application of a number of these techniques to the solution of problems in the fields of friction, lubrication, and wear are examined in detail for the particular case of iron; and in general to illustrate how the accumulation of pure data will contribute toward the establishment of physiochemical concepts which are required to understand the mechanisms that are operational in friction systems. In the case of iron, LEED, Auger and microcontact studies have established that hydrogen and light-saturated organic vapors do not establish interfaces which prevent iron from welding, whereas oxygen and some oxygen and sulfur compounds do reduce welding as well as the coefficient of friction. Interpretation of these data suggests a mechanism of sulfur interaction in lubricating systems.

  13. Angle-resolved photoemission on the Kondo surface alloy CePd{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Mulazzi, Mattia; Seibel, Christoph; Schwab, Holger [Universitaet Wuerzburg, Experimentelle Physik VII (Germany); Shimada, Kenya; Jiang, Jiang [Graduate School of Science, Hiroshima University, Higashi-Hiroshima (Japan); Reinert, Friedrich [Universitaet Wuerzburg, Experimentelle Physik VII (Germany); Karlsruhe Institute of Technology KIT, Gemeinschaftslabor fuer Nanoanalytik, Karlsruhe (Germany)

    2013-07-01

    This films of the Cerium were evaporated on a Pd(001) substrate an further annealed to obtain a thin surface alloy layer of stoichiometry CePd{sub 7}, as observed by Auger spectroscopy. From LEED measurements it was possible to determine that the alloy has a (√(5) x √(5))R26.6 {sup circle} reconstruction, commensurate to the Palladium substrate. Photon-energy dependent ARPES measurements crossing the 4d-4f resonance show the presence of a strong peak near the Fermi level, having actually two components, the actual Kondo peak at the Fermi level and the spin-orbit peak at 280 meV binding energy. Resonant and non-resonant Fermi surface maps shows large intensity variations of the Pd bands, when measured at the resonance, a sign of strong hybridization between the conduction and the 4f electrons. While previous work assigns the CePd7 to the class of intermediate valence systems, our work shows that it is actually a Kondo system, with a rather high Kondo temperature.

  14. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index

    International Nuclear Information System (INIS)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M.

    2016-01-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  15. Convex surfaces

    CERN Document Server

    Busemann, Herbert

    2008-01-01

    This exploration of convex surfaces focuses on extrinsic geometry and applications of the Brunn-Minkowski theory. It also examines intrinsic geometry and the realization of intrinsic metrics. 1958 edition.

  16. Surface boxplots

    KAUST Repository

    Genton, Marc G.

    2014-01-22

    In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.

  17. Surface boxplots

    KAUST Repository

    Genton, Marc G.; Johnson, Christopher; Potter, Kristin; Stenchikov, Georgiy L.; Sun, Ying

    2014-01-01

    In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.

  18. Surface channeling

    International Nuclear Information System (INIS)

    Sizmann, R.; Varelas, C.

    1976-01-01

    There is experimental evidence that swift light ions incident at small angles towards single crystalline surfaces can lose an appreciable fraction of their kinetic energy during reflection. It is shown that these projectiles penetrate into the bulk surface region of the crystal. They can travel as channeled particles along long paths through the solid (surface channeling). The angular distribution and the depth history of the re-emerged projectiles are investigated by computer simulations. A considerable fraction of the penetrating projectiles re-emerges from the crystal with constant transverse energy if the angle of incidence is smaller than the critical angle for axial channeling. Analytical formulae are derived based on a diffusion model for surface channeling. A comparison with experimental data exhibits the relevance of the analytical solutions. (Auth.)

  19. Martian surface

    International Nuclear Information System (INIS)

    Carr, M.H.

    1987-01-01

    The surface of Mars is characterized on the basis of reformatted Viking remote-sensing data, summarizing results published during the period 1983-1986. Topics examined include impact craters, ridges and faults, volcanic studies (modeling of surface effects on volcanic activity, description and interpretation of volcanic features, and calculations on lava-ice interactions), the role of liquid water on Mars, evidence for abundant ground ice at high latitudes, water-cycle modeling, and the composition and dynamics of Martian dust

  20. Surface decontamination

    International Nuclear Information System (INIS)

    Silva, S. da; Teixeira, M.V.

    1986-06-01

    The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt

  1. Surface states in an external electric field

    International Nuclear Information System (INIS)

    Steslicka, M.

    1975-10-01

    Under conditions typical for field ion microscopy, true surface states can exist. Their shift towards higher energies can be quite significant and, moreover, additional surface levels at still higher energies can appear. The latter can play an important role in the process of tunneling of image gas electrons into surface states

  2. Surface phonons

    CERN Document Server

    Wette, Frederik

    1991-01-01

    In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech­ niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen­ tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, co...

  3. Stiff Columns as Liquefaction Mitigation Measure for Retrofit of Existing Buildings

    Directory of Open Access Journals (Sweden)

    Zaheer Ahmed Almani

    2012-10-01

    Full Text Available In this paper, ground reinforcement with jet grouted columns under shallow foundations of existing buildings was analysed using numerical modelling. This study is related with ground reinforcement by installing stiff jet grouted columns around the shallow foundations of existing building when the foundation soil is liquefied during an earthquake. The isolated shallow square footing pad supporting a typical simple frame structure was constructed on the reinforced ground with stiff jet grouted column rows at the shallow depth from the ground surface. This soil-structure system was modelled and analyzed as plane-strain using the FLAC (Fast Lagrangian Analysis of Continua 2D dynamic modelling and analysis software. The results showed that liquefaction-induced large settlement of shallow foundation of existing building can be reduced to tolerable limits by applying ground reinforcement with continuous rows vertical jet grouted columns adjacent to footing pad.

  4. Changes of electronic properties of p-GaN(0 0 0 1) surface after low-energy N+-ion bombardment

    Science.gov (United States)

    Grodzicki, M.; Mazur, P.; Ciszewski, A.

    2018-05-01

    The p-GaN(0 0 0 1) crystal with a relatively low acceptor concentration of 5 × 1016 cm-3 is used in these studies, which are carried out in situ under ultrahigh vacuum (UHV) by ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED). The p-GaN(0 0 0 1)-(1 × 1) surface is achieved by thermal cleaning. N+-ion bombardment by a 200 eV ion beam changes the surface stoichiometry, enriches it with nitrogen, and disorders it. Such modified surface layer inverts its semiconducting character from p- into n-type. The electron affinity for the already cleaned p-GaN surface and that just after bombardment shows a shift from 2.2 eV to 3.2 eV, as well as an increase of band bending at the vacuum/surface interface from 1.4 eV to 2.5 eV. Proper post-bombardment heating of the sample restores the initial atomic order of the modified layer, leaving its n-type semiconducting character unchanged. The results of the measurements are discussed based on two types of surface states concepts.

  5. A coupled chemotaxis-fluid model: Global existence

    KAUST Repository

    Liu, Jian-Guo; Lorz, Alexander

    2011-01-01

    We consider a model arising from biology, consisting of chemotaxis equations coupled to viscous incompressible fluid equations through transport and external forcing. Global existence of solutions to the Cauchy problem is investigated under certain conditions. Precisely, for the chemotaxis-Navier- Stokes system in two space dimensions, we obtain global existence for large data. In three space dimensions, we prove global existence of weak solutions for the chemotaxis-Stokes system with nonlinear diffusion for the cell density.© 2011 Elsevier Masson SAS. All rights reserved.

  6. A coupled chemotaxis-fluid model: Global existence

    KAUST Repository

    Liu, Jian-Guo

    2011-09-01

    We consider a model arising from biology, consisting of chemotaxis equations coupled to viscous incompressible fluid equations through transport and external forcing. Global existence of solutions to the Cauchy problem is investigated under certain conditions. Precisely, for the chemotaxis-Navier- Stokes system in two space dimensions, we obtain global existence for large data. In three space dimensions, we prove global existence of weak solutions for the chemotaxis-Stokes system with nonlinear diffusion for the cell density.© 2011 Elsevier Masson SAS. All rights reserved.

  7. Electronic properties of semiconductor surfaces and metal/semiconductor interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tallarida, M.

    2005-05-15

    This thesis reports investigations of the electronic properties of a semiconductor surface (silicon carbide), a reactive metal/semiconductor interface (manganese/silicon) and a non-reactive metal/semiconductor interface (aluminum-magnesium alloy/silicon). The (2 x 1) reconstruction of the 6H-SiC(0001) surface has been obtained by cleaving the sample along the (0001) direction. This reconstruction has not been observed up to now for this compound, and has been compared with those of similar elemental semiconductors of the fourth group of the periodic table. This comparison has been carried out by making use of photoemission spectroscopy, analyzing the core level shifts of both Si 2p and C 1s core levels in terms of charge transfer between atoms of both elements and in different chemical environments. From this comparison, a difference between the reconstruction on the Si-terminated and the C-terminated surface was established, due to the ionic nature of the Si-C bond. The growth of manganese films on Si(111) in the 1-5 ML thickness range has been studied by means of LEED, STM and photoemission spectroscopy. By the complementary use of these surface science techniques, two different phases have been observed for two thickness regimes (<1 ML and >1 ML), which exhibit a different electronic character. The two reconstructions, the (1 x 1)-phase and the ({radical}3 x {radical}3)R30 -phase, are due to silicide formation, as observed in core level spectroscopy. The growth proceeds via island formation in the monolayer regime, while the thicker films show flat layers interrupted by deep holes. On the basis of STM investigations, this growth mode has been attributed to strain due to lattice mismatch between the substrate and the silicide. Co-deposition of Al and Mg onto a Si(111) substrate at low temperature (100K) resulted in the formation of thin alloy films. By varying the relative content of both elements, the thin films exhibited different electronic properties

  8. CCl 4 chemistry on the reduced selvedge of a α-Fe 2O 3(0 0 0 1) surface: a scanning tunneling microscopy study

    Science.gov (United States)

    Rim, Kwang Taeg; Fitts, Jeffrey P.; Müller, Thomas; Adib, Kaveh; Camillone, Nicholas; Osgood, Richard M.; Joyce, S. A.; Flynn, George W.

    2003-09-01

    Scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) were used to study the degradation of CCl 4 on the reduced selvedge of a natural single crystal α-Fe 2O 3(0 0 0 1) surface in ultrahigh vacuum. Before exposure to CCl 4, STM images indicate that approximately 85% of the reduced surface exhibits a Fe 3O 4(1 1 1) 2 × 2 termination, while the remaining 15% is terminated by 1 × 1 and superstructure phases. Images obtained after room temperature dosing with CCl 4 and subsequent flashing to 600 K reveal that chlorine atoms are adsorbed only on surface regions with the Fe 3O 4(1 1 1) 2 × 2 termination, not on 1 × 1 and superstructure regions. Chlorine atoms from dissociative adsorption of CCl 4 are observed to occupy two distinct positions located atop lattice protrusions and in threefold oxygen vacancy sites. However, in companion chemical labeling experiments, chlorine atoms provided by room temperature, dissociative Cl 2 adsorption on this surface are found to occupy sites atop lattice protrusions exclusively. The clear dissimilarity in STM feature shape and brightness at the two distinct chlorine adsorption sites arising from CCl 4 dissociation as well as the results of the Cl 2 chemical labeling experiments are best explained via reactions on a Fe 3O 4(1 1 1) 2 × 2 selvedge terminated by a 1/4 monolayer of tetrahedrally coordinated iron atoms. On this surface, adsorption atop an iron atom occurs for both the CCl 4 and Cl 2 dissociative reactions. A second adsorption site, assigned as binding to second layer iron atoms left exposed following surface oxygen atom abstraction resulting in the formation of phosgene (COCl 2), only appears in the case of reaction with CCl 4. The reaction mechanism and active site requirements for CCl 4 degradation on iron oxide surfaces are discussed in light of this evidence and in the context of our previously reported results from Auger electron spectroscopy (AES), LEED, temperature-programmed desorption

  9. 40 CFR 407.64 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Fruits Subcategory § 407.64 Pretreatment standards for existing sources. Any...

  10. Branding in children: a barbaric practice still exists in India.

    Science.gov (United States)

    Patra, Pratap Kumar

    2016-01-01

    Branding is an inhuman traditional practice most commonly employed to treat various disorders in neonates and children in certain community in India. Though stringent law exists to prevent such harmful practices, cases of branding is not uncommon in current era.

  11. Non-existence of limit cycles for planar vector fields

    Directory of Open Access Journals (Sweden)

    Jaume Gine

    2014-03-01

    Full Text Available This article presents sufficient conditions for the non-existence of limit cycles for planar vector fields. Classical methods for the nonexistence of limit cycles are connected with the theory developed here.

  12. 31 CFR 370.26 - What limitations exist on liability?

    Science.gov (United States)

    2010-07-01

    ... TRANSFERS RELATING TO UNITED STATES SECURITIES Debit Entries § 370.26 What limitations exist on liability? If we sustain a loss because a financial institution fails to handle an entry in accordance with this...

  13. Protection of continued economic existence and major changes. 1. paper

    International Nuclear Information System (INIS)

    Backherms, J.

    1980-01-01

    On the issue of protecting continued economic existence according to Sect. 18 of the Atomic Energy Law, a difference is made between changes occurring in the environment of the plant, in the existing knowledge in science and technology, and changes occurring in the safety philosophy held by the authorities. In case of conditions being subsequently imposed because of a change in the existing knowledge in science and technology, the liability of the authorities to pay compensation is ruled out according to Sect. 18, para. 2 No. 3 of the Atomic Energy Law. The difference made between a change in the safety philosophy held by the authorities and a change in the existing knowledge in science and technology seems to be obvious. In the first case it is a matter of changing the legal evaluation of unchanged technological findings, in the legal evaluation, however, the licence granted has to have a lasting effect on principle. (HP) [de

  14. Existence results for anisotropic discrete boundary value problems

    Directory of Open Access Journals (Sweden)

    Avci Avci

    2016-06-01

    Full Text Available In this article, we prove the existence of nontrivial weak solutions for a class of discrete boundary value problems. The main tools used here are the variational principle and critical point theory.

  15. Possible existence of wormholes in the central regions of halos

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Farook, E-mail: rahaman@iucaa.ernet.in [Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal (India); Salucci, P., E-mail: salucci@sissa.it [SISSA, International School for Advanced Studies, Via Bonomea 265, 34136, Trieste (Italy); INFN, Sezione di Trieste, Via Valerio 2, 34127, Trieste (Italy); Kuhfittig, P.K.F., E-mail: kuhfitti@msoe.edu [Department of Mathematics, Milwaukee School of Engineering, Milwaukee, WI 53202-3109 (United States); Ray, Saibal, E-mail: saibal@iucaa.ernet.in [Department of Physics, Government College of Engineering and Ceramic Technology, Kolkata 700010, West Bengal (India); Rahaman, Mosiur, E-mail: mosiurju@gmail.com [Department of Mathematics, Meghnad Saha Institute of Technology, Kolkata 700150 (India)

    2014-11-15

    An earlier study (Rahaman, et al., 2014 and Kuhfittig, 2014) has demonstrated the possible existence of wormholes in the outer regions of the galactic halo, based on the Navarro–Frenk–White (NFW) density profile. This paper uses the Universal Rotation Curve (URC) dark matter model to obtain analogous results for the central parts of the halo. This result is an important compliment to the earlier result, thereby confirming the possible existence of wormholes in most of the spiral galaxies. - Highlights: • Earlier we showed possible existence of wormholes in the outer regions of halo. • We obtain here analogous results for the central parts of the galactic halo. • Our result is an important compliment to the earlier result. • This confirms possible existence of wormholes in most of the spiral galaxies.

  16. DOES ABSOLUTE SYNONYMY EXIST IN OWERE-IGBO?

    African Journals Online (AJOL)

    USER

    The researcher also interviewed native speakers of the dialect. The study ... The word 'synonymy' means sameness of meaning, i.e., a relationship in which more ... whether absolute synonymy exists in Owere–Igbo or not. ..... 'close this book'.

  17. Existence of Solutions of Nonlinear Integrodifferential Equations of ...

    Indian Academy of Sciences (India)

    Abstract. In this paper we prove the existence of mild and strong solutions of a nonlinear integrodifferential equation of Sobolev type with nonlocal condition. The results are obtained by using semigroup theory and the Schauder fixed point theorem.

  18. Problem of mathematical deduction of the existence of black holes

    Directory of Open Access Journals (Sweden)

    Yuan-Shun Chin

    1990-01-01

    Full Text Available The mathematical proof of existence of Black Hole is based on the assumption of mass being independent of speed. Considering the effect of special relativity of the dependence of mass with speed there is no Black hole.

  19. On the existence and dynamics of braneworld black holes

    International Nuclear Information System (INIS)

    Fitzpatrick, Andrew Liam; Randall, Lisa; Wiseman, Toby

    2006-01-01

    Based on holographic arguments Tanaka and Emparan et al have claimed that large localized static black holes do not exist in the one-brane Randall-Sundrum model. If such black holes are time-dependent as they propose, there are potentially significant phenomenological and theoretical consequences. We revisit the issue, arguing that their reasoning does not take into account the strongly coupled nature of the holographic theory. We claim that static black holes with smooth metrics should indeed exist in these theories, and give a simple example. However, although the existence of such solutions is relevant to exact and numerical solution searches, such static solutions might be dynamically unstable, again leading to time dependence with phenomenological consequences. We explore a plausible instability, suggested by Tanaka, analogous to that of Gregory and Laflamme, but argue that there is no reliable reason at this point to assume it must exist

  20. A corrosion monitoring system for existing reinforced concrete structures.

    Science.gov (United States)

    2015-05-01

    This study evaluated a multi-parameter corrosion monitoring system for existing reinforced concrete structures in chloride-laden service environments. The system was fabricated based on a prototype concrete corrosion measurement system that : had bee...

  1. Report on the Pre-existing Condition Insurance Plan Program

    Data.gov (United States)

    U.S. Department of Health & Human Services — Before the Affordable Care Act, Americans with pre-existing conditions who did not receive health coverage through their employers had few affordable options to get...

  2. Existence for a class of discrete hyperbolic problems

    Directory of Open Access Journals (Sweden)

    Luca Rodica

    2006-01-01

    Full Text Available We investigate the existence and uniqueness of solutions to a class of discrete hyperbolic systems with some nonlinear extreme conditions and initial data, in a real Hilbert space.

  3. Existence of Weak Solutions for a Nonlinear Elliptic System

    Directory of Open Access Journals (Sweden)

    Gilbert RobertP

    2009-01-01

    Full Text Available We investigate the existence of weak solutions to the following Dirichlet boundary value problem, which occurs when modeling an injection molding process with a partial slip condition on the boundary. We have in ; in ; , and on .

  4. Existence of Positive Solutions for Nonlinear Eigenvalue Problems

    Directory of Open Access Journals (Sweden)

    Wong Fu-Hsiang

    2010-01-01

    Full Text Available We use a fixed point theorem in a cone to obtain the existence of positive solutions of the differential equation, , , with some suitable boundary conditions, where is a parameter.

  5. comparative performance evaluation of an existing and modified

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    and fan speeds of 2800 rpm as against the existing cylinder and fan speeds of 934 rpm. The performance evaluation for ... KEYWORDS: Acha, fonio, dehuller, performance evaluation, ... centrifugal force as a result of the rotation of the cylinder.

  6. Newspaper and internet display advertising: Co-existence or substitution?

    OpenAIRE

    Lindstädt, Nadine; Budzinski, Oliver

    2012-01-01

    Newspapers have been experiencing declining circulation figures and diminishing advertising revenues for several years – both effects might pose a threat to the continuing existence of (print) newspapers. In an earlier paper, Lindstädt & Budzinski (2011) argued from a theoretical viewpoint that industry-specific patterns exist that determine substitution or complementation effects between internet and newspaper advertising. It was argued that retail advertising, in particular, may offer a nic...

  7. Evaluation of the integrity of existing NFS waste tanks

    International Nuclear Information System (INIS)

    1977-12-01

    Various means of investigating the integrity of the existing NFS waste tanks are presented, including: visual inspection, ultrasonic testing, acoustic-emission monitoring, radiography, and forced-vibration testing. The experience that exists in performing such investigations of high-level radioactive waste tanks is documented, including: visual inspections, photography, wall-thickness measurements, and forced-vibration testing. An evaluation is made on the relative merits of the presented inspection and testing alternatives

  8. Non-existence criteria for Laurent polynomial first integrals

    Directory of Open Access Journals (Sweden)

    Shaoyun Shi

    2003-01-01

    Full Text Available In this paper we derived some simple criteria for non-existence and partial non-existence Laurent polynomial first integrals for a general nonlinear systems of ordinary differential equations $\\dot x = f(x$, $x \\in \\mathbb{R}^n$ with $f(0 = 0$. We show that if the eigenvalues of the Jacobi matrix of the vector field $f(x$ are $\\mathbb{Z}$-independent, then the system has no nontrivial Laurent polynomial integrals.

  9. Existence of solitary waves in dipolar quantum gases

    KAUST Repository

    Antonelli, Paolo; Sparber, Christof

    2011-01-01

    We study a nonlinear Schrdinger equation arising in the mean field description of dipolar quantum gases. Under the assumption of sufficiently strong dipolar interactions, the existence of standing waves, and hence solitons, is proved together with some of their properties. This gives a rigorous argument for the possible existence of solitary waves in BoseEinstein condensates, which originate solely due to the dipolar interaction between the particles. © 2010 Elsevier B.V. All rights reserved.

  10. The existence and persistence of household financial hardship

    OpenAIRE

    Brown, S.; Ghosh, P.; Taylor, K.

    2012-01-01

    We investigate the existence and persistence of financial hardship at the household level using data from the British Household Panel Survey. Our modelling strategy makes three important contributions to the existing literature on household finances. Firstly, we model nine different types of household financial problems within a joint framework, allowing for correlation in the random effects across the nine equations. Secondly, we develop a dynamic framework in order to model the persistence ...

  11. Existence of solutions to quasilinear Schrodinger equations with indefinite potential

    Directory of Open Access Journals (Sweden)

    Zupei Shen

    2015-04-01

    Full Text Available In this article, we study the existence and multiplicity of solutions of the quasilinear Schrodinger equation $$ -u''+V(xu-(|u| ^2''u=f(u $$ on $\\mathbb{R}$, where the potential $V$ allows sign changing and the nonlinearity satisfies conditions weaker than the classical Ambrosetti-Rabinowitz condition. By a local linking theorem and the fountain theorem, we obtain the existence and multiplicity of solutions for the equation.

  12. How Do We Know Protons, Electrons, and Quarks Really Exist?

    Science.gov (United States)

    Robertson, Bill

    2005-01-01

    Scientific explanations often make use of things that cannot be seen or felt, such as protons, electrons, and quarks. Do these things really exist? If so, how do is it known that they exist? Imagine being enclosed in a completely dark room with no light at all and not being able to see a thing. Being chained to a chair somewhere in the room, and…

  13. Existence of solitary waves in dipolar quantum gases

    KAUST Repository

    Antonelli, Paolo

    2011-02-01

    We study a nonlinear Schrdinger equation arising in the mean field description of dipolar quantum gases. Under the assumption of sufficiently strong dipolar interactions, the existence of standing waves, and hence solitons, is proved together with some of their properties. This gives a rigorous argument for the possible existence of solitary waves in BoseEinstein condensates, which originate solely due to the dipolar interaction between the particles. © 2010 Elsevier B.V. All rights reserved.

  14. On-surface synthesis on a bulk insulator surface

    Science.gov (United States)

    Richter, Antje; Floris, Andrea; Bechstein, Ralf; Kantorovich, Lev; Kühnle, Angelika

    2018-04-01

    On-surface synthesis has rapidly emerged as a most promising approach to prepare functional molecular structures directly on a support surface. Compared to solution synthesis, performing chemical reactions on a surface offers several exciting new options: due to the absence of a solvent, reactions can be envisioned that are otherwise not feasible due to the insolubility of the reaction product. Perhaps even more important, the confinement to a two-dimensional surface might enable reaction pathways that are not accessible otherwise. Consequently, on-surface synthesis has attracted great attention in the last decade, with an impressive number of classical reactions transferred to a surface as well as new reactions demonstrated that have no classical analogue. So far, the majority of the work has been carried out on conducting surfaces. However, when aiming for electronic decoupling of the resulting structures, e.g. for the use in future molecular electronic devices, non-conducting surfaces are highly desired. Here, we review the current status of on-surface reactions demonstrated on the (10.4) surface of the bulk insulator calcite. Besides thermally induced C-C coupling of halogen-substituted aryls, photochemically induced [2  +  2] cycloaddition has been proven possible on this surface. Moreover, experimental evidence exists for coupling of terminal alkynes as well as diacetylene polymerization. While imaging of the resulting structures with dynamic atomic force microscopy provides a direct means of reaction verification, the detailed reaction pathway often remains unclear. Especially in cases where the presence of metal atoms is known to catalyze the corresponding solution chemistry reaction (e.g. in the case of the Ullmann reaction), disclosing the precise reaction pathway is of importance to understand and generalize on-surface reactivity on a bulk insulator surface. To this end, density-functional theory calculations have proven to provide atomic

  15. Interfacing the existing cask fleet with the MRS

    International Nuclear Information System (INIS)

    Doman, J.W.; Hahn, R.E.

    1992-01-01

    This paper reports that the Department of Energy (DOE) is considering the possibility of using the existing fleet of casks to achieve spent fuel receipt at the Monitored Retrievable Storage (MRS) facility. The existing cask fleet includes the NLI-1/2, the NAC-LWT, the TN-8 (and TN-8L), the TN-9, and the IF-300 casks. Other casks may be available, but their status is not certain. Use of the existing cask fleet at the MRS places additional design requirements on the system, and specifically affects the cask-to-MRS interface. The decision to use the existing cask fleet also places additional demands on training needs and operator certification, and the configuration management system. Some existing cask designs may not be able to mate with a bottom opening hot cell MRS. Use of the existing cask fleet also greatly increases the number of shipments that must be received, to the point that a facility larger than originally envisioned may be required

  16. Study of structural reliability of existing concrete structures

    Science.gov (United States)

    Druķis, P.; Gaile, L.; Valtere, K.; Pakrastiņš, L.; Goremikins, V.

    2017-10-01

    Structural reliability of buildings has become an important issue after the collapse of a shopping center in Riga 21.11.2013, caused the death of 54 people. The reliability of a building is the practice of designing, constructing, operating, maintaining and removing buildings in ways that ensure maintained health, ward suffered injuries or death due to use of the building. Evaluation and improvement of existing buildings is becoming more and more important. For a large part of existing buildings, the design life has been reached or will be reached in the near future. The structures of these buildings need to be reassessed in order to find out whether the safety requirements are met. The safety requirements provided by the Eurocodes are a starting point for the assessment of safety. However, it would be uneconomical to require all existing buildings and structures to comply fully with these new codes and corresponding safety levels, therefore the assessment of existing buildings differs with each design situation. This case study describes the simple and practical procedure of determination of minimal reliability index β of existing concrete structures designed by different codes than Eurocodes and allows to reassess the actual reliability level of different structural elements of existing buildings under design load.

  17. Mostly surfaces

    CERN Document Server

    Schwartz, Richard Evan

    2011-01-01

    This book presents a number of topics related to surfaces, such as Euclidean, spherical and hyperbolic geometry, the fundamental group, universal covering surfaces, Riemannian manifolds, the Gauss-Bonnet Theorem, and the Riemann mapping theorem. The main idea is to get to some interesting mathematics without too much formality. The book also includes some material only tangentially related to surfaces, such as the Cauchy Rigidity Theorem, the Dehn Dissection Theorem, and the Banach-Tarski Theorem. The goal of the book is to present a tapestry of ideas from various areas of mathematics in a clear and rigorous yet informal and friendly way. Prerequisites include undergraduate courses in real analysis and in linear algebra, and some knowledge of complex analysis.

  18. Surface rights

    Directory of Open Access Journals (Sweden)

    Regina Célia Corrêa Landim

    2009-06-01

    Full Text Available In many cities of Brazil, social inequality is illustrated by violence, poverty, and unemployment located next to luxurious residential towers and armored passenger cars. In the face of this situation, the National Movement of Urban Reform encouraged the inclusion of the social function of property in Brazil's new constitution of 1988. Surface rights represent an urbanistic instrument in the city statute that is best aligned to the constitutional principles and urban policies. The current article compares two laws that govern the principle of surface rights and provides a brief history of the evolution of the state based on illuminism and the consequent change in paradigm affecting individual rights, including property and civil rights, and their interpretation under the Constitution. The article concludes by suggesting the use of land surface rights in a joint operation, matching the ownership of the property with urban planning policies and social interest.

  19. Critical behavior of collapsing surfaces

    DEFF Research Database (Denmark)

    Olsen, Kasper; Sourdis, C.

    2009-01-01

    We consider the mean curvature evolution of rotationally symmetric surfaces. Using numerical methods, we detect critical behavior at the threshold of singularity formation resembling that of gravitational collapse. In particular, the mean curvature simulation of a one-parameter family of initial...... data reveals the existence of a critical initial surface that develops a degenerate neckpinch. The limiting flow of the type II singularity is accurately modeled by the rotationally symmetric translating soliton....

  20. Wettability of natural superhydrophobic surfaces.

    Science.gov (United States)

    Webb, Hayden K; Crawford, Russell J; Ivanova, Elena P

    2014-08-01

    Since the description of the 'Lotus Effect' by Barthlott and Neinhuis in 1997, the existence of superhydrophobic surfaces in the natural world has become common knowledge. Superhydrophobicity is associated with a number of possible evolutionary benefits that may be bestowed upon an organism, ranging from the ease of dewetting of their surfaces and therefore prevention of encumbrance by water droplets, self-cleaning and removal of particulates and potential pathogens, and even to antimicrobial activity. The superhydrophobic properties of natural surfaces have been attributed to the presence of hierarchical microscale (>1 μm) and nanoscale (typically below 200 nm) structures on the surface, and as a result, the generation of topographical hierarchy is usually considered of high importance in the fabrication of synthetic superhydrophobic surfaces. When one surveys the breadth of data available on naturally existing superhydrophobic surfaces, however, it can be observed that topographical hierarchy is not present on all naturally superhydrophobic surfaces; in fact, the only universal feature of these surfaces is the presence of a sophisticated nanoscale structure. Additionally, several natural surfaces, e.g. those present on rose petals and gecko feet, display high water contact angles and high adhesion of droplets, due to the pinning effect. These surfaces are not truly superhydrophobic, and lack significant degrees of nanoscale roughness. Here, we discuss the phenomena of superhydrophobicity and pseudo-superhydrophobicity in nature, and present an argument that while hierarchical surface roughness may aid in the stability of the superhydrophobic effect, it is nanoscale surface architecture alone that is the true determinant of superhydrophobicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Enhanced photochemistry on metal surfaces

    International Nuclear Information System (INIS)

    Goncher, G.M.; Parsons, C.A.; Harris, C.B.

    1984-01-01

    Due to the fast relaxation of molecular excited states in the vicinity of a metal or semiconductor surface, few observations of surface photochemistry have been reported. The following work concerns the surface-enhanced photo-reactions of a variety of physisorbed molecules on roughened Ag surfaces. In summary, photodecomposition leads to a graphitic surface carbon product which is monitored via surface-enhanced Raman scattering. In most cases an initial two-photon molecular absorption step followed by further absorption and fragmentation is thought to occur. Enhancement of the incident fields occurs through roughness-mediated surface plasmon resonances. This mechanism provides the amplified electromagnetic surface fields responsible for the observed photodecomposition. The photodecomposition experiments are performed under ultra-high vacuum. Surface characterization of the roughened surfaces was done by Scanning Electron Microscopy (SEM), and electron-stimulated emission. The SEM revealed morphology on the order of 300-400 A. This size of roughness feature, when modelled as isolated spheres should exhibit the well-known Mie resonances for light of the correct wavelengths. For protrusions existing on a surface these Mie resonances can be thought of as a coupling of the light with the surface plasmon. Experimental verification of these resonances was provided by the electron-stimulated light emission results. These showed that a polished Ag surface emitted only the expected transition radiation at the frequency of the Ag bulk plasmon. Upon roughening, however, a broad range of lower frequencies extending well into the visible are seen from electron irradiation of the surface. Large enhancements are expected for those frequencies which are able to couple into the surface modes

  2. Existence conditions of optimal trajectories in dynamic control processes; Conditions d'existence de trajectoires optimales des processus dynamiques commandes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnemay-Juricek, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    The existence of solutions in the optimal control problems with free endpoints is studied in this report and existence conditions are established without the usual assumption that the control region is convex. Furthermore the results, in order to be of some utility in physical applications, are expressed only by means of conditions on the parameters defining the system. (author) [French] Ce rapport etudie l'existence de solutions optimales dans les problemes de commande ou le point terminal est libre et ou la duree de l'evolution du systeme a optimiser est connue. Des conditions d'existence y sont formulees sans recourir a l'hypothese usuelle de convexite du domaine des valeurs des commandes. De plus on a cherche a rendre utilisables les resultats en ne faisant porter les conditions que sur les parametres directement accessibles du systeme. (auteur)

  3. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

  4. Wild translation surfaces and infinite genus

    OpenAIRE

    Randecker, Anja

    2014-01-01

    The Gauss-Bonnet formula for classical translation surfaces relates the cone angle of the singularities (geometry) to the genus of the surface (topology). When considering more general translation surfaces, we observe so-called wild singularities for which the notion of cone angle is not applicable any more. In this article, we study whether there still exist relations between the geometry and the topology for translation surfaces with wild singularities. By considering short saddle connectio...

  5. Studies of the surface structures of molecular crystals and of adsorbed molecular monolayers on the (111) crystal faces of platinum and silver by low-energy electron diffraction

    International Nuclear Information System (INIS)

    Firment, L.E.

    1977-01-01

    The structures of molecular crystal surfaces were investigated for the first time by the use of low-energy electron diffraction (LEED). The experimental results from a variety of molecular crystals were examined and compared as a first step towards understanding the properties of these surfaces on a microscopic level. The method of sample preparation employed, vapor deposition onto metal single-crystal substrates at low temperatures in ultrahigh vacuum, allowed concurrent study of the structures of adsorbed monolayers on metal surfaces and of the growth processes of molecular films on metal substrates. The systems investigated were ice, ammonia, naphthalene, benzene, the n-paraffins (C 3 to C 8 ), cyclohexane, trioxane, acetic acid, propionic acid, methanol, and methylamine adsorbed and condensed on both Pt(111) and Ag(111) surfaces. Electron-beam-induced damage of the molecular surfaces was observed after electron exposures of 10 -4 A sec cm -2 at 20 eV. Aromatic molecular crystal samples were more resistant to damage than samples of saturated molecules. The quality and orientation of the grown molecular crystal films were influenced by substrate preparation and growth conditions. Forty ordered monolayer structures were observed. 110 figures, 22 tables, 162 references

  6. Electron beam induced Hg desorption and the electronic structure of the Hg depleted surface of Hg1/sub -//sub x/Cd/sub x/Te

    International Nuclear Information System (INIS)

    Shih, C.K.; Friedman, D.J.; Bertness, K.A.; Lindau, I.; Spicer, W.E.; Wilson, J.A.

    1986-01-01

    Auger electron spectroscopy (AES), x-ray photoemission spectroscopy (XPS), low energy electron diffraction (LEED), and angle-resolved ultraviolet photoemission spectroscopy (ARPES) were used to study the electron beam induced Hg desorption from a cleaved (110)Hg/sub 1-//sub x/Cd/sub x/Te surface and the electronic structure of the Hg depleted surface. Solid state recrystallized Hg/sub 1-//sub x/Cd/sub x/Te single crystals were used. It was found that the electron beam heating dominated the electron beam induced Hg desorption on Hg/sub 1-//sub x/Cd/sub x/Te. At the electron beam energy used, the electron beam heating extended several thousand angstroms deep. However, the Hg depletion saturated after a few monolayers were depleted of Hg atoms. At the initial stage of Hg loss (only 3%), the surface band bends upward (more p type). The ARPES spectrum showed the loss of some E vs k dispersion after 22% Hg atoms were removed from the surface region, and no dispersion was observed after 43% Hg atoms were removed. These results have important implications on the electronic structure of the surfaces and interfaces of which the stoichiometry is altered

  7. Greening Existing Buildings in Contemporary Iraqi Urban Reality/ Virtual Model

    Directory of Open Access Journals (Sweden)

    Saba Jabar Neama Al-Khafaji

    2015-11-01

    Full Text Available The approach of greening existing buildings, is an urgent necessity, because the greening operation provides the speed and optimal efficiency in the environmental performance, as well as keeping up with the global green architecture revolution. Therefore, greening existing buildings in Iraq is important for trends towards renewable energies, because of what the country went through economic conditions and crises and wars which kept the country away from what took place globally in this issue. The research problem is: insufficient knowledge about the importance and the mechanism of the greening of existing buildings, including its environmental and economic dimensions, by rationalization of energy consumption and preserving the environment. The research objective is: clarifying the importance of greening existing buildings environmentally and economically, providing a virtual experience for greening the presidency building of Baghdad University, through advanced computer program. The main conclusions is: there is difference representing by reducing the disbursed thermal loads amount for cooling in summer and heating in winter through the use of computerized program (DesignBuilder and that after the implementation of greening operations on the building envelope, which confirms its effectiveness in raising the energy performance efficiency inside the building. Hence, the importance of the application of greening existing buildings approach in Iraq, to bring back Iraqi architecture to environmental and local track proper.

  8. Seismic performance of existing R.C. framed buildings

    Directory of Open Access Journals (Sweden)

    Sameh A. El-Betar

    2017-08-01

    Full Text Available The earthquakes disasters basically occur due to buildings damage not because of the earth shaking. Therefore, the countries have being updated the seismic codes. The seismic loads for buildings design in Egyptian Code have been changed from (EC-1994 to (ECP-201, 2012. On the other hand, the need is raised to study the vulnerability of existing buildings, which can be divided into the buildings designed to resist the gravity loads only (GLD and the buildings designed according to Egyptian code (EC-1994. Comparison between forces due to Egyptian code for loads (EC-1994 and (ECP-201, 2012 is carried out on the multi-stories R.C. framed buildings which are the most common type of existing buildings in Egypt. To investigate the vulnerability of existing buildings, nonlinear static pushover analysis is conducted to evaluate the real strength of the existing buildings. Moreover, it is considered a useful and effective tool for the performance of three framed buildings: 3, 6 and 10 stories due to expected future earthquakes. Finally, it is found that the vulnerability of existing GLD buildings occurs at expected ground accelerations (ag greater than 0.125 g in Egyptian seismic map, while the EC-94 designed buildings behave elastically up to (ag equals to 0.2 g and above that a slight damage may occur.

  9. Energy and architecture: improvement of energy performance in existing buildings

    Energy Technology Data Exchange (ETDEWEB)

    Haase, Matthias; Wycmans, Annemie; Solbraa, Anne; Grytli, Eir

    2011-07-01

    This book aims to give an overview of different aspects of retrofitting existing buildings. The target group is students of architecture and building engineering as well as building professionals. Eight out of ten buildings which we will inhabit in 2050 already exist. This means that a great potential for reducing our carbon footprint lies in the existing building stock. Students from NTNU have used the renovation of a 1950s school building at Linesoeya in Soer-Trondelag as a case to increase their awareness and knowledge about the challenges building professionals need to overcome to unite technical details and high user quality into good environmental performance. The students were invited by the building owners and initiators of LIPA Eco Project to contribute to its development: By retrofitting an existing building to passive house standards and combining this with energy generated on site, LIPA Eco Project aims to provide a hands-on example with regard to energy efficiency, architectural design and craftsmanship for a low carbon society. The overall goal for this project is to raise awareness regarding resource efficiency measures in architecture and particularly in existing building mass.(au)

  10. Electronic structure of epitaxial chalcopyrite surfaces and interfaces for photovoltaics

    International Nuclear Information System (INIS)

    Hofmann, Andreas

    2012-01-01

    This thesis constitutes a comprehensive study of the surface physics of epitaxial CuInSe 2 films. It comprises analyses of the surface morphology and reconstruction, electronic band structure as well as hetero-junctions relevant to photovoltaic applications. Therefore, especially the aspect of stoichiometry variation from the CuInSe 2 to the copper-deficient defect phases was considered. Preparation and analysis was completely performed under ultra-high vacuum conditions in order to ensure the investigation of well-defined samples free of contaminants. For some of the analysis techniques, single-crystalline samples are indispensable: They allow for the determination of surface periodicity by low-energy electron diffraction (LEED). In combination with concentration depth profiling by angle-resolved x-ray photoemission, to types of surface reconstructions could be distinguished for the near-stoichiometric CuInSe 2 (112) surface. In the copper-rich case, it is stabilized by Cu In anti-site defects and on the indium-rich side by 2 V Cu defects, as predicted by surface total energy calculations by Jaffe and Zunger. Both configurations correspond to a c(4 x 2) reconstruction of the zinc blende type (111) surface. For the defect compound CuIn 3 Se 5 , a sphalerite order of the surface was found, which points at a weakening or absence of the chalcopyrite order in the bulk of the material. The unusual stability of the (112) surface could also be proven by comparison with the reconstruction and surface order of (001) and (220) surfaces. The results from surface analysis were used to measure the valence band structure of the epitaxial samples by synchrotron-based angle-resolved photoelectron spectroscopy. The CuInSe 2 (001) surface gives access to the high symmetry directions Γ-T and Γ-N of momentum space. By contrasting the data obtained for the stoichiometric surface with the copper-poor defect compound, a reduction of the valence band dispersion and a broadening of

  11. Army LEED-Certified Projects, August 2008 - January 2011

    Science.gov (United States)

    2011-06-01

    well as rain gardens for stormwater management. The site contains pervious concrete and impervious paving is shaded. The use of native and adapted...conveyance impact on local infrastructure. The project utilizes a high thermal performance envelope using site cast tilt-up concrete panels, thermally broken...tube skylights with parabolic lenses to track the sun’s movement are combined with large areas of translucent panels (KalWall) daylight the repair bays

  12. The Development of Sport Expertise: From Leeds to MVP Legend.

    Science.gov (United States)

    Thomas, Katherine Thomas

    1994-01-01

    Contributions of motor skill and cognition to sport performance change across age, expertise, and sports. Knowledge and decision making should not limit the development of expertise. Specific strategies for teachers may help students develop expertise. The paper discusses the contribution of knowledge and skill to expertise and its development.…

  13. Cost Analysis of Leed Certified United States Navy Buildings

    Science.gov (United States)

    2011-08-03

    be accumulated in order to offset initial investment costs - St = Savings in operational costs in year t associated with a given alternative - ∆I0...ior Non-Structural Elements er.o• 2 1 Construction Waste ManagenMnt Oivort 50% fro m Disposal Crocllt 22 Construction Waste Managemen t , Divert 75... Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding

  14. Translation and cultural adaptation of the Leeds Assessment of ...

    African Journals Online (AJOL)

    Sabri Garoushi

    2017-10-03

    Oct 3, 2017 ... (LANSS) pain scale into Arabic for use with patients with diabetes in Libya .... Arabic version of the LANSS was translated back into English by a .... One hundred and ten participants enrolled and all completed the study (age ...

  15. Existence domains of dust-acoustic solitons and supersolitons

    International Nuclear Information System (INIS)

    Maharaj, S. K.; Bharuthram, R.; Singh, S. V.; Lakhina, G. S.

    2013-01-01

    Using the Sagdeev potential method, the existence of large amplitude dust-acoustic solitons and supersolitons is investigated in a plasma comprising cold negative dust, adiabatic positive dust, Boltzmann electrons, and non-thermal ions. This model supports the existence of positive potential supersolitons in a certain region in parameter space in addition to regular solitons having negative and positive potentials. The lower Mach number limit for supersolitons coincides with the occurrence of double layers whereas the upper limit is imposed by the constraint that the adiabatic positive dust number density must remain real valued. The upper Mach number limits for negative potential (positive potential) solitons coincide with limiting values of the negative (positive) potential for which the negative (positive) dust number density is real valued. Alternatively, the existence of positive potential solitons can terminate when positive potential double layers occur

  16. The Existence of a Sticking Region in Free Weight Squats

    Directory of Open Access Journals (Sweden)

    Tillaar Roland van den

    2014-10-01

    Full Text Available The aim of this study was to investigate the existence of the sticking region in two legged free weight squats. Fifteen resistance-training males (age 24 ± 4 years, body mass 82 ± 11 kg, body height 179 ± 6 cm with 6 ± 3 years of resistance-training experience performed 6-RM in free weight squats. The last repetition was analyzed for the existence of a sticking region. Only in 10 out of 15 participants a sticking region was observed. The observed sticking region was much shorter than in the bench press. Furthermore, rectus femoris decreased the EMG activity in contrast to increased EMG activity in biceps femoris around the sticking and surrounding region. No significant change in EMG activity was found for the lateral and medial vastus muscles. It is suggested that a combination of these muscle activity changes could be one of the causes of the existence of the sticking region in free weight squats

  17. The existence of a sticking region in free weight squats.

    Science.gov (United States)

    van den Tillaar, Roland; Andersen, Vidar; Saeterbakken, Atle Hole

    2014-09-29

    The aim of this study was to investigate the existence of the sticking region in two legged free weight squats. Fifteen resistance-training males (age 24 ± 4 years, body mass 82 ± 11 kg, body height 179 ± 6 cm) with 6 ± 3 years of resistance-training experience performed 6-RM in free weight squats. The last repetition was analyzed for the existence of a sticking region. Only in 10 out of 15 participants a sticking region was observed. The observed sticking region was much shorter than in the bench press. Furthermore, rectus femoris decreased the EMG activity in contrast to increased EMG activity in biceps femoris around the sticking and surrounding region. No significant change in EMG activity was found for the lateral and medial vastus muscles. It is suggested that a combination of these muscle activity changes could be one of the causes of the existence of the sticking region in free weight squats.

  18. Islamic Banking Existence and Domestic Credit: Study at Seven Countries

    Directory of Open Access Journals (Sweden)

    Hamdan Yuafi

    2017-05-01

    Full Text Available This paper empirically investigates the determinants of domestic credit across a wide range of 7 countries; these are United Kingdom, Malaysia, Egypt, Kuwait, Qatar, Bahrain and Indonesia. We use dynamic panel estimation to examine effects of exchange rate, inflation, lending interest rate, banking crisis and existence of wholesale Islamic banking on domestic credit. We obtain several notable empirical results. First, the lending interest rate, banking crisis negatively and insignificantly contribute to domestic credit. The existence of Islamic bank has positive and insignificant contribution to domestic credit, while exchange rate positively and significantly contributes to domestic credit.  Inflation negatively and significantly contributes to domestic credit. Second, banking crisis and existence of wholesale Islamic banking show insignificant effect on domestic credit. Third, we find that today’s domestic credit is depended on domestic credit in the previous year.DOI: 10.15408/aiq9i2.4906

  19. Existing sustainable renovation concepts for single-family houses

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Vanhoutteghem, Lies; Svendsen, Svend

    2010-01-01

    In the Nordic Innovation Centre Project, SuccessFamilies, the main objective is to change the business environment in order to speed up the implementation of sustainable renovation of single-family houses – proposing new service concepts that will combine both the technical solutions, financing...... with individual solutions, traditional warehouses ”do-it-yourself-shops” and some actors marketing single products. To speed up the implementation of sustainable renovation of single-family houses there is a great need for full-service packages. Existing technical renovation concepts, typically focusing...... services as well as other promoting issues to overcome the behavioural, organizational, legal and social barriers that exist in sustainable renovation. A starting point for such a change has been to get an overview of the existing sustainable renovation concepts, i.e. full-service concepts and technical...

  20. Intersubjective Dimension of Existence in the Philosophy of Gabriel Marcel

    Directory of Open Access Journals (Sweden)

    Martín Grassi

    2016-05-01

    Full Text Available The present work intends to introduce the reader to the essential dimension of intersubjectivity in personal existence in Gabriel Marcel’s philosophy. We will first attend to the characterization of persona; secondly, how we should understand the terms I and the other in concrete interpersonal relationships; in the third place, we will analize the way in which the other is given as an other, through the notion of presence. The main objective of this article is to show that personal existence is uncomprehensible without its reference to the other, that is to say, that identity has no sense without alterity. Moreover, the essential intencionality of identity to alterity does not imply only a practical or accidental character, but a metaphysical one, as communion constitutes the very being of personal existence.

  1. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    OpenAIRE

    Kimura, Yusuke

    2018-01-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface i...

  2. Global Analysis of Minimal Surfaces

    CERN Document Server

    Dierkes, Ulrich; Tromba, Anthony J

    2010-01-01

    Many properties of minimal surfaces are of a global nature, and this is already true for the results treated in the first two volumes of the treatise. Part I of the present book can be viewed as an extension of these results. For instance, the first two chapters deal with existence, regularity and uniqueness theorems for minimal surfaces with partially free boundaries. Here one of the main features is the possibility of 'edge-crawling' along free parts of the boundary. The third chapter deals with a priori estimates for minimal surfaces in higher dimensions and for minimizers of singular integ

  3. Existing PON Infrastructure Supported Hybrid Fiber-Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhao, Ying; Deng, Lei

    2012-01-01

    We propose a hybrid fiber wireless sensor network based on the existing PON infrastructure. The feasibility of remote sensing and PON convergence is experimentally proven by transmitting direct-sequence spread-spectrum wireless sensing and 2.5Gbps GPON signals.......We propose a hybrid fiber wireless sensor network based on the existing PON infrastructure. The feasibility of remote sensing and PON convergence is experimentally proven by transmitting direct-sequence spread-spectrum wireless sensing and 2.5Gbps GPON signals....

  4. Existing and Expected Service Quality of Grameenphone Users in Bangladesh

    Directory of Open Access Journals (Sweden)

    Azmat Ullah

    2015-12-01

    Full Text Available The Grameenphone (GP is a market leader in the telecommunication industry in Bangladesh. This study investigates the existing and expected service quality of Grameenphone users in Bangladesh. The Study reveals that there are significant gap between existing and expected perceived service network, 3G, customer care, physical facilities, billing cost, information service, mobile banking and GP offers. The study concludes that customer satisfaction is a dynamic phenomenon. Maintaining desired level of customer satisfaction requires corporate proactive responsiveness in accessing, building & retaining satisfied customers for sustainable competitive advantages in the marketplace.

  5. Principle of space existence and De Sitter metric

    International Nuclear Information System (INIS)

    Mal'tsev, V.K.

    1990-01-01

    The selection principle for the solutions of the Einstein equations suggested in a series of papers implies the existence of space (g ik ≠ 0) only in the presence of matter (T ik ≠0). This selection principle (principle of space existence, in the Markov terminology) implies, in the general case, the absence of the cosmological solution with the De Sitter metric. On the other hand, the De Sitter metric is necessary for describing both inflation and deflation periods of the Universe. It is shown that the De Sitter metric is also allowed by the selection principle under discussion if the metric experiences the evolution into the Friedmann metric

  6. [Does the right to die with dignity exist?].

    Science.gov (United States)

    Toro Flores, Rafael

    2008-12-01

    Death is one of the few certainties in human beings. This reality generates uneasiness regarding how death will occur especially in circumstances of loneliness or suffering which can become agony. In this report, the author first analyzes the existence of the right to die with dignity as a human right which takes on the nature of being a subjective right. In continuation, the author describes the existing problematic in the application of this right to die in relationship to the so-called double effect mechanism and euthanasia. The author concludes this article by proposing previous instructions or anticipated desires as ideal measures to make the right to die with dignity valid.

  7. On the existence of n-dimensional indecomposable vector bundles

    International Nuclear Information System (INIS)

    Tan Xiaojiang.

    1991-09-01

    Let X be an arbitrary smooth irreducible complex projective curve of genus g with g ≥ 4. In this paper we extend the existence theorem of special divisors to high dimensional indecomposable vector bundles. We give a necessary and sufficient condition on the existence of n-dimensional indecomposable vector bundles E with deg(E) = d, dimH 0 (X,E) ≥ h. We also determine under what condition the set of all such vector bundles will be finite and how many elements it contains. (author). 9 refs

  8. FMDP reactor alternative summary report. Volume 1 - existing LWR alternative

    International Nuclear Information System (INIS)

    Greene, S.R.; Bevard, B.B.

    1996-01-01

    Significant quantities of weapons-usable fissile materials [primarily plutonium and highly enriched uranium (HEU)] are becoming surplus to national defense needs in both the United States and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety, and health (ES ampersand H) consequences if surplus fissile materials are not properly managed. This document summarizes the results of analysis concerned with existing light water reactor plutonium disposition alternatives

  9. Existence of core localized toroidicity-induced Alfven eigenmode

    International Nuclear Information System (INIS)

    Fu, G.Y.

    1995-02-01

    The core-localized toroidicity-induced Alfven eigenmode (TAE) is shown to exist at finite plasma pressure due to finite aspect ratio effects in tokamak plasma. The new critical beta for the existence of the TAE mode is given by α∼ 3ε + 2s 2 , where ε = r/R is the inverse aspect ratio, s is the magnetic shear and α = -Rq 2 dβ/dr is the normalized pressure gradient. In contrast, previous critical α is given by α ∼ s 2 . In the limit of s << √r/R, the new critical α is greatly enhanced by the finite aspect ratio effects

  10. FMDP reactor alternative summary report. Volume 1 - existing LWR alternative

    Energy Technology Data Exchange (ETDEWEB)

    Greene, S.R.; Bevard, B.B. [and others

    1996-10-07

    Significant quantities of weapons-usable fissile materials [primarily plutonium and highly enriched uranium (HEU)] are becoming surplus to national defense needs in both the United States and Russia. These stocks of fissile materials pose significant dangers to national and international security. The dangers exist not only in the potential proliferation of nuclear weapons but also in the potential for environmental, safety, and health (ES&H) consequences if surplus fissile materials are not properly managed. This document summarizes the results of analysis concerned with existing light water reactor plutonium disposition alternatives.

  11. Surface smoothness

    DEFF Research Database (Denmark)

    Tummala, Sudhakar; Dam, Erik B.

    2010-01-01

    accuracy, such novel markers must therefore be validated against clinically meaningful end-goals such as the ability to allow correct diagnosis. We present a method for automatic cartilage surface smoothness quantification in the knee joint. The quantification is based on a curvature flow method used....... We demonstrate that the fully automatic markers eliminate the time required for radiologist annotations, and in addition provide a diagnostic marker superior to the evaluated semi-manual markers....

  12. Fusion technology development: first wall/blanket system and component testing in existing nuclear facilities

    International Nuclear Information System (INIS)

    Hsu, P.Y.S.; Bohn, T.S.; Deis, G.A.; Judd, J.L.; Longhurst, G.R.; Miller, L.G.; Millsap, D.A.; Scott, A.J.; Wessol, D.E.

    1980-12-01

    A novel concept to produce a reasonable simulation of a fusion first wall/blanket test environment employing an existing nuclear facility, the Engineering Test Reactor at the Idaho National Engineering Laboratory, is presented. Preliminary results show that an asymmetric, nuclear test environment with surface and volumetric heating rates similar to those expected in a fusion first wall/blanket or divertor chamber surface appears feasible. The proposed concept takes advantage of nuclear reactions within the annulus of an existing test space (15 cm in diameter and approximately 100 cm high) to provide an energy flux to the surface of a test module. The principal reaction considered involves 3 He in the annulus as follows: n + 3 He → p + t + 0.75 MeV. Bulk heating in the test module is accomplished by neutron thermalization, gamma heating, and absorption reactions involving 6 Li in the blanket breeding region. The concept can be extended to modified core configurations that will accommodate test modules of different sizes and types. It makes possible development testing of first wall/blanket systems and other fusion components on a scale and in ways not otherwise available until actual high-power fusion reactors are built

  13. Perceptual Aspects of Postural Control: Does Pure Proprioceptive Training Exist?

    Science.gov (United States)

    Nagy, Edit; Posa, Gabriella; Finta, Regina; Szilagyi, Levente; Sziver, Edit

    2018-06-01

    As proprioceptive training is popular for injury prevention and rehabilitation, we evaluated its effect on balance parameters and assessed the frequency spectra of postural sway linked with the various sensory channels. We recorded the Center of Mass displacement of 30 healthy student research participants (mean age = 21.63; SD = 1.29 years) with a single force plate under eyes open (EO) and eyes closed (EC) positions while standing on either a firm or foam surface, both before and after an 8-week balance training intervention on a foam surface with EC. We subjected the data to frequency power spectral analysis to find any differences between the frequency bands, linked with various sensory data. On the foam surface in the EC condition, the sway path decreased significantly after proprioceptive training, but, on the firm surface in the EC condition, there was no change. On the foam surface in the EC condition, there was also a significant decrease in frequency power postproprioceptive training in the medium-to-low frequency band. While our data indicate better posttraining balance skills, improvements were task specific to the trained condition, with no transfer of the acquired skill, even to a similar, easier condition. As training improved the middle-low frequency band, linked with vestibular signals, this intervention is better described as balance than "proprioceptive" training.

  14. Cu-capped surface alloys of Pt/Cu left brace 100 right brace

    CERN Document Server

    Alshamaileh, E; Wander, A

    2003-01-01

    The room-temperature deposition of 0.5 monolayer (ML) Pt on Cu left brace 100 right brace followed by annealing to 525 K results in a sharp c(2 x 2) low-energy electron diffraction (LEED) pattern. The structure of this surface alloy is investigated by means of symmetrized automated tensor low-energy electron diffraction (SATLEED) analysis and ab initio plane wave density functional calculations. The results are then compared with those for the similar system 0.5 ML Pd/Cu left brace 100 right brace. SATLEED results for the Pt/Cu left brace 100 right brace show that it consists of an ordered c(2 x 2) Cu-Pt second layer alloy capped with a pure Cu first layer. The first and second interlayer spacings are found to be expanded by +5.1 +- 1.7 and +3.5 +- 1.7% respectively (relative to the bulk Cu interlayer spacing of 1.807 A) due to the insertion of the 8% larger Pt atoms into the second layer. The ordered mixed layer is found to be rippled by 0.08 +- 0.06 A with Pt atoms rippled outwards towards the solid-vacuum ...

  15. Epitaxial growth of a methoxy-functionalized quaterphenylene on alkali halide surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Balzer, F., E-mail: fbalzer@mci.sdu.dk [University of Southern Denmark, Mads Clausen Institute, Alsion 2, DK-6400 Sønderborg (Denmark); Sun, R. [University of Southern Denmark, Mads Clausen Institute, Alsion 2, DK-6400 Sønderborg (Denmark); Parisi, J. [University of Oldenburg, Energy and Semiconductor Research Laboratory, Institute of Physics, Carl-von-Ossietzky-Str. 9-11, D-26111 Oldenburg (Germany); Rubahn, H.-G. [University of Southern Denmark, Mads Clausen Institute, Alsion 2, DK-6400 Sønderborg (Denmark); Lützen, A. [University of Bonn, Kekulé Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany); Schiek, M. [University of Oldenburg, Energy and Semiconductor Research Laboratory, Institute of Physics, Carl-von-Ossietzky-Str. 9-11, D-26111 Oldenburg (Germany)

    2015-12-31

    The epitaxial growth of the methoxy functionalized para-quaterphenylene (MOP4) on the (001) faces of the alkali halides NaCl and KCl and on glass is investigated by a combination of low energy electron diffraction (LEED), polarized light microscopy (PLM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Both domains from upright molecules as well as fiber-like crystallites from lying molecules form. Neither a wetting layer from lying molecules nor widespread epitaxial fiber growth on the substrates is detected. Our results focus on the upright standing molecules, which condense into a thin film phase with an enlarged layer spacing compared to the bulk phase. - Highlights: • Growth of a methoxy-functionalized para-phenylene on dielectric surfaces is investigated. • Low-energy electron diffraction and X-ray diffraction techniques are employed for structural characterization. • Epitaxial growth of upright molecules only is documented. • Polarized optical microscopy together with atomic force microscopy complements the findings.

  16. Epitaxial growth of a methoxy-functionalized quaterphenylene on alkali halide surfaces

    International Nuclear Information System (INIS)

    Balzer, F.; Sun, R.; Parisi, J.; Rubahn, H.-G.; Lützen, A.; Schiek, M.

    2015-01-01

    The epitaxial growth of the methoxy functionalized para-quaterphenylene (MOP4) on the (001) faces of the alkali halides NaCl and KCl and on glass is investigated by a combination of low energy electron diffraction (LEED), polarized light microscopy (PLM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Both domains from upright molecules as well as fiber-like crystallites from lying molecules form. Neither a wetting layer from lying molecules nor widespread epitaxial fiber growth on the substrates is detected. Our results focus on the upright standing molecules, which condense into a thin film phase with an enlarged layer spacing compared to the bulk phase. - Highlights: • Growth of a methoxy-functionalized para-phenylene on dielectric surfaces is investigated. • Low-energy electron diffraction and X-ray diffraction techniques are employed for structural characterization. • Epitaxial growth of upright molecules only is documented. • Polarized optical microscopy together with atomic force microscopy complements the findings.

  17. Probabilistic risk assessment for new and existing chemicals: Example calculations

    NARCIS (Netherlands)

    Jager T; Hollander HA den; Janssen GB; Poel P van der; Rikken MGJ; Vermeire TG; ECO; CSR; LAE; CSR

    2000-01-01

    In the risk assessment methods for new and existing chemicals in the EU, "risk" is characterised by means of the deterministic quotient of exposure and effects (PEC/PNEC or Margin of Safety). From a scientific viewpoint, the uncertainty in the risk quotient should be accounted for explicitly in the

  18. 40 CFR 407.14 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 407.14 Section 407.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE...

  19. 40 CFR 407.34 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 407.34 Section 407.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE...

  20. 40 CFR 407.24 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 407.24 Section 407.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE...

  1. 40 CFR 406.14 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.14 Section 406.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.14...

  2. 40 CFR 406.24 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.24 Section 406.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Dry Milling Subcategory § 406.24...

  3. Building OOC layers on top of existing courses

    DEFF Research Database (Denmark)

    Bang, Jørgen; Dalsgaard, Christian; Kjær, Arne

    2016-01-01

    prefer the term "Open Online Courses", MOOCs (Massive Open Online Courses) without the M. This paper will present our approach to building OOCs on top of existing campusbased courses at Aarhus University, Denmark. Consequently, participants of an 'OOC track' will engage in collaboration and discussions...

  4. 40 CFR 421.275 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... Nickel 0.000 0.000 (e) Sodium hypochlorite filter backwash. PSES for the Primary Rare Earth Metals...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Primary Rare Earth Metals Subcategory § 421.275 Pretreatment standards for existing sources. Except as provided in 40 CFR...

  5. A unifying approach to existence of Nash equilibria

    NARCIS (Netherlands)

    Balder, E.J.

    1997-01-01

    An approach initiated in [4] is shown to unify results about the existence of (i) Nash equilibria in games with at most countably many players, (ii) Cournot-Nash equilibrium distributions for large, anonymous games, and (iii) Nash equilibria (both mixed and pure) for continuum games. A new, central

  6. Priority setting for existing chemicals : automated data selection routine

    NARCIS (Netherlands)

    Haelst, A.G. van; Hansen, B.G.

    2000-01-01

    One of the four steps within Council Regulation 793/93/EEC on the evaluation and control of existing chemicals is the priority setting step. The priority setting step is concerned with selecting high-priority substances from a large number of substances, initially starting with 2,474

  7. Existence of Green's functions in perturbative Q.E.D

    International Nuclear Information System (INIS)

    Seneor, R.

    1976-01-01

    A report is made on some work done in collaboration with P. Blanchard which shows how, in the framework developped by H.Epstein and V.Glaser, one can prove the existence of Green's functions in quantum electrodynamics (Q.E.D.). The proof can be extended, in principle, to any theory involving massive and non massive particles. (Auth.)

  8. Existence of solutions of abstract fractional impulsive semilinear evolution equations

    Directory of Open Access Journals (Sweden)

    K. Balachandran

    2010-01-01

    Full Text Available In this paper we prove the existence of solutions of fractional impulsive semilinear evolution equations in Banach spaces. A nonlocal Cauchy problem is discussed for the evolution equations. The results are obtained using fractional calculus and fixed point theorems. An example is provided to illustrate the theory.

  9. Priors & prejudice : using existing knowledge in social science research

    NARCIS (Netherlands)

    Van Wesel, F.

    2011-01-01

    Researchers in the social sciences usually start their research with the formulation of research goals and questions, which, together with studying the existing literature, lead to the formulation of hypotheses. Next, data is collected using experiments or questionnaires and is subsequently

  10. Low energy house in existing buildings; Niedrigenergiehaus im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Sahner, G. [BDA, Stuttgart/Augsburg (Germany)

    2008-07-01

    Presented is an energetic sanitation of residential units in the frame of a German pilot program (''low energy houses in the existing building sector'') initiated by the ministry of traffic, civil engineering and city development. (GL)

  11. On existence and stability of solutions for higher order semilinear ...

    Indian Academy of Sciences (India)

    To be precise, we consider a primal action functional for which the Dirichlet problem is an Euler–Lagrange equation, later we define a suitable dual action functional and by introducing a duality theory we investigate relations between both action function- als. Our method is based on investigating the existence of a minimum ...

  12. Preretirement Programs within Service Firms: Existing and Planned Programs.

    Science.gov (United States)

    Siegel, Sidney R.; Rives, Janet M.

    1980-01-01

    A study of 300 nonmanufacturing firms' current and projected preretirement programs indicated that (1) personnel departments have primary responsibility for existing programs, (2) focus is changing from financial planning to psychological counseling, and (3) such programs benefit the company as well as the employee. (SK)

  13. Existence and multiplicity results for homoclinic orbits of Hamiltonian systems

    Directory of Open Access Journals (Sweden)

    Chao-Nien Chen

    1997-03-01

    Full Text Available Homoclinic orbits play an important role in the study of qualitative behavior of dynamical systems. Such kinds of orbits have been studied since the time of Poincare. In this paper, we discuss how to use variational methods to study the existence of homoclinic orbits of Hamiltonian systems.

  14. On the existence of weak solutions of quantum stochastic differential ...

    African Journals Online (AJOL)

    We establish further results concerning the existence, uniqueness and stability of weak solutions of quantum stochastic differential equations (QSDEs). Our results are achieved by considering a more general Lipschit condition on the coefficients than our previous considerations in [1]. We exhibit a class of Lipschitzian ...

  15. Existence and Policy Effectiveness in Feedback Nash LQ-Games

    Directory of Open Access Journals (Sweden)

    Nicola Acocella

    2008-12-01

    Full Text Available This paper illustrates how the classical theory of economic policy can profitably be used to verify some properties of the Linear Nash Feedback Equilibrium in difference LQ-games. In particular, we find that both a necessary condition for the equilibrium existence and a sufficient condition for policy ineffectiveness can be defined in the terms of the simple Tinbergen counting rule.

  16. Existence of global attractor for the Trojan Y Chromosome model

    Directory of Open Access Journals (Sweden)

    Xiaopeng Zhao

    2012-04-01

    Full Text Available This paper is concerned with the long time behavior of solution for the equation derived by the Trojan Y Chromosome (TYC model with spatial spread. Based on the regularity estimates for the semigroups and the classical existence theorem of global attractors, we prove that this equations possesses a global attractor in $H^k(\\Omega^4$ $(k\\geq 0$ space.

  17. Why Choose Online Learning: Relationship of Existing Factors and Chronobiology

    Science.gov (United States)

    Luo, Yi; Pan, Rui; Choi, Jea H.; Mellish, Linda; Strobel, Johannes

    2011-01-01

    Existing research on choice of online learning utilized factors such as perceived level of control, independence, and satisfaction, yet the relationship among these factors is under-researched. Due to the value of "learning anytime," biological factors underlying "choice of time" might provide additional insights. This article…

  18. 49 CFR 1300.2 - Disclosure requirement for existing rates.

    Science.gov (United States)

    2010-10-01

    ..., PUBLICATION, AND NOTICE OF CHANGE OF RATES AND OTHER SERVICE TERMS FOR RAIL COMMON CARRIAGE § 1300.2 Disclosure requirement for existing rates. (a) A rail carrier must disclose to any person, upon formal... rail carrier under this section must be provided immediately. (It is expected that the response will be...

  19. The existence of solutions of q-difference-differential equations.

    Science.gov (United States)

    Wang, Xin-Li; Wang, Hua; Xu, Hong-Yan

    2016-01-01

    By using the Nevanlinna theory of value distribution, we investigate the existence of solutions of some types of non-linear q-difference differential equations. In particular, we generalize the Rellich-Wittich-type theorem and Malmquist-type theorem about differential equations to the case of q-difference differential equations (system).

  20. Man-machine enhancements to existing FFTF control panels

    International Nuclear Information System (INIS)

    Miller, E.M.

    1984-01-01

    FFTF Project enhanced existing control panels with tape and labels to mitigate operator problems and to incorporate the guidance of NUREG-0700. The enhancements grouped displays and controls into meaningful units and labelled controls and displays to facilitate their identification and efficient use. The enhancements were inexpensive and well received by the facility's operations staff