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  1. Le rapport au savoir scientifique d'enseignantes et d'enseignants du primaire

    NASA Astrophysics Data System (ADS)

    Plonczak, Irene

    Nous avons procede a l'examen de problemes relatifs a l'education aux sciences via une approche a caractere epistemologique, contrairement a l'approche plus usuelle qui aborde les difficultes des apprenants a composer avec les connaissances dites scientifiques seulement d'un point de vue cognitif. La question de recherche que nous nous sommes posee a ete la suivante: Quel est le rapport au savoir scientifique d'enseignantes et d'enseignants du primaire? Pour repondre a cette question sur le plan methodologique, nous avons envisage l'etude du rapport au savoir scientifique d'enseignantes et d'enseignants dans un contexte relie a leur savoir et a leur expertise de tous les jours. Nos modalites de cueillette de donnees ont ete le recit ecrit et l'entrevue individuelle semi-structuree. Notre recherche a pris la forme d'une etude de cas multiples conduisant a l'etude des rapports epistemique, pratique et identitaire au savoir scientifique de dix enseignantes et enseignants d'ecoles populaires de Caracas, au Venezuela. Nos analyses nous ont amenee a affirmer que les sujets ont manifeste un rapport au savoir scientifique domine par la dependance et la soumission a l'egard des sciences ainsi que d'autres caracteristiques propres a une approche empirico-realiste. Cependant, dans un contexte relie a leur savoir-faire et a leur expertise, nous avons repere des traces de l'emergence d'une vision des sciences qui tient compte, entre autres, du caractere social de la production de ces dernieres, ce qui pourrait se qualifier comme faisant partie d'une tendance epistemologique du type socioconstructiviste. En plus, nos analyses nous amenent a suggerer que dans ce contexte les sujets auraient egalement initie une articulation entre leur savoir-faire et le savoir scientifique, ce qui les aurait amenes a vehiculer un rapport plus emancipatoire vis-a-vis les sciences. Cette articulation des savoirs permet egalement d'envisager des experiences educatives plus creatives, plus emancipatoires et plus en lien avec les visions contemporaines emergentes de la science, de son enseignement et de son apprentissage. Bien que de nombreuses recherches dans le domaine de l'education soulignent l'importance d'articuler les savoirs disciplinaires avec les savoirs d'experience, peu illustrent de maniere approfondie l'exercice de cette articulation. Notre recherche permet de penser a l'idee d'un rapport au savoir qui donne une veritable place a l'expertise publique des individus et non seulement a l'explication scientifique jugee la seule valable. Ainsi, au-dela des hierarchisations, chaque savoir aurait sa valeur et sa place, l'articulation des savoirs favorisant chez les sujets apprenants un plus grand interet pour l'apprentissage des sciences.

  2. ASTER Suez Canal

    NASA Technical Reports Server (NTRS)

    2000-01-01

    One of the most important waterways in the world, the Suez Canal runs north to south across the Isthmus of Suez in northeastern Egypt. This image of the canal covers an area 36 kilometers (22 miles) wide and 60 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. It shows the northern part of the canal, with the Mediterranean Sea just visible in the upper right corner. The Suez Canal connects the Mediterranean Sea with the Gulf of Suez, an arm of the Red Sea. The artificial canal provides an important shortcut for ships operating between both European and American ports and ports located in southern Asia, eastern Africa, and Oceania. With a length of about 195 kilometers (121 miles) and a minimum channel width of 60 meters (197 feet), the Suez Canal is able to accommodate ships as large as 150,000 tons fully loaded. Because no locks interrupt traffic on this sea level waterway, the transit time only averages about 15 hours. ASTER acquired this scene on May 19, 2000.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and retreats, potentially active volcanoes, thermal pollution, and coral reef degradation; identifying crop stress; determining cloud morphology and physical properties; evaluating wetlands; mapping surface temperature of soils and geology; and measuring surface heat balance.

  3. Suez Canal, Gulf of Suez, Sinai Peninsula, Egypt, as seen from the Apollo 7

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Suez Canal, Gulf of Suez, Sinai Peninsula, United Arab Republic (Egypt), Mediterranean Sea, as seen from the Apollo 7 spacecraft during its 13th revolution of the earth. Photographed from an altitude of 126 nautical miles, at ground elapsed time of 19 hours and 42 minutes.

  4. Rapport in Distance Education

    ERIC Educational Resources Information Center

    Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.

    2012-01-01

    Rapport has been recognized as important in learning in general but little is known about its importance in distance education (DE). The study we report on in this paper provides insights into the importance of rapport in DE as well as challenges to and indicators of rapport-building in DE. The study relied on interviews with 42 Canadian…

  5. Structural evolution along the Suez rift

    SciTech Connect

    Colletta, B.; Lequellec, P.; Letouzey, J.; Moretti, I.

    1988-08-01

    A three-dimensional study of the structure of the Suez rift was carried out using field and subsurface data in and attempt to determine the role of transverse faults and the longitudinal evolution of the rift. The structure of the Gulf of Suez area is governed by normal faults and tilted blocks whose crests constitute the main target of exploratory wells. The fault pattern consists of two majors sets of trends: (1) longitudinal faults parallel to the rift axis and created in an extensional regime where /sigma//sub 3/ was trending east-northeast-west-southwest, and (2) transverse faults with a north-south to north-northeast-south-southwest dominant trend. The transverse faults are inherited passive discontinuities, while most of the longitudinal faults were created during Neogene times in a pure extensional regime. Both sets were simultaneously active, producing a zigzag pattern and rhombic-shaped blocks. The transverse faults act as relays between major normal faults. Cross profiles show that all the major blocks are tilted in the same direction. However, the tilt direction changes: north and south of the rift the blocks tilt eastward, and in the center they tilt westward. To the north the change of dip is accommodated by a graben-type twist zone without transverse faulting, at least in the Neogene series. To the south the change of dip is accommodated by a more complex structure involving both a major transverse fault and a horst-type twist-zone. Balanced cross sections show that the tilt angle and the amount of extension increase from north to south, while the width of the blocks decreases. Minimum values for the amount of opening range between 5 km to the north to about 20 km to the south.

  6. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... certificated under the system prescribed in 35 CFR part 135. (b) All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules...

  7. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... certificated under the system prescribed in 35 CFR part 135. (b) All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules...

  8. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... certificated under the system prescribed in 35 CFR part 135. (b) All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules...

  9. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... certificated under the system prescribed in 35 CFR part 135. (b) All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules...

  10. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... certificated under the system prescribed in 35 CFR part 135. (b) All vessels intending to transit the Suez Canal must be measured and certificated under the Arab Republic of Egypt Suez Canal Authority Rules...

  11. Games of Rapport.

    ERIC Educational Resources Information Center

    Corbin, Sandra J.

    1980-01-01

    Board games called Games of Rapport are being developed at the University of Alberta. The first, "Angels and Devils," is designed for play by nursing home residents. Results of a study involving "Angels and Devils" show that board games are useful in communicating rehabilitative objectives and sources of conflict. (Author/BEF)

  12. Adlai Stevenson and the Suez Crisis of 1956.

    ERIC Educational Resources Information Center

    Graff, Leo W., Jr.

    1982-01-01

    This study examines Adlai Stevenson's response to the Suez crisis, the Arab-Israeli conflict, and the struggle between the nationalism emerging in Third World countries and the imperialism fading in Europe. It also looks at Stevenson's stance toward Israel and his relations with American Zionists during the 1956 presidential campaign. (AM)

  13. A review of potential tsunami impacts to the Suez Canal

    NASA Astrophysics Data System (ADS)

    Finkl, C.; Pelinovsky, E.

    2012-04-01

    Destructive tsunamis in the eastern Mediterranean and Red seas, induced by earthquakes and/or volcanic activity, pose potential hazards to docked seaport shipping and fixed harbor infrastructure as well as to in-transit international shipping within the Suez Canal. Potential vulnerabilities of the Suez Canal to possible tsunami impacts are reviewed by reference to geological, historical, archaeoseismological, and anecdotal data. Tsunami catalogues and databases compiled by earlier researchers are perused to estimate potential return periods for tsunami events that could affect directly the Suez Canal and its closely associated operational infrastructures. Analysis of these various records indicates a centurial return period, or multiples thereof, for long-wave repetition that could generally affect the Nile Delta. It is estimated that tsunami waves 2 m high would have a breaking length about 5 km down Canal whereas a 10 m wave break would occur about 1 km into the Canal. Should a tsunami strike the eastern flanks of the Nile Delta, it would damage Egypt's maritime infrastructure and multi-national commercial vessels and military ships then using the Canal.

  14. 75 FR 57911 - Application To Export Electric Energy; GDF SUEZ Energy Marketing NA, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... Application To Export Electric Energy; GDF SUEZ Energy Marketing NA, Inc. AGENCY: Office of Electricity Delivery and Energy Reliability, DOE. ACTION: Notice of application. SUMMARY: GDF SUEZ Energy Marketing NA... utilities, Federal power marketing agencies and other entities within the United States. The...

  15. Graben infilling in Gulf of Suez and Red Sea

    SciTech Connect

    Burollet, P.F.

    1986-05-01

    During the last 4 years, the French research group Genegass has completed geological and geophysical studies in the Red Sea and the Gulf of Suez. Neogene infilling of the basin is related with basement quality and volume of clastic supply, and inherited structural features are important to the development of Miocene rifting. The Neogene series may be divided into four major groups (Listed A-D), each limited by unconformities that seem to reflect the major stages of rifting. (A) The lowermost formations begin with a conglomerate and are followed by a variegated unit of sand and clay. In the Gulf of Suez, especially on the eastern bank, these formations are marine. Along the Red Sea, tilted blocks may be capped by stromatolites, and the valleys between them are the site of shale and evaporite sedimentation (lower Miocene). (B) The main extension phase results in an invasion of marine shales. The lower zones contain coarse clastics, and the high zones contain reefs and bioclastic limestone (late Burdigalian to early Serravallian). (C) The middle to late Miocene corresponds to a regional basinward tilting. Stromatolites coat the slopes, and conglomerate fans are found in the lower zones. Evaporite sedimentation dominates; anhydrite is found on the borders, and in the basin, thick halite is overlain by a clastic series. Basement shoulders are uplifted. (D) During the Pliocene and Pleistocene, the central part of the graben showed an important subsidence, and salt tectonism was active with diapirs and collapses.

  16. Intentionally Building Rapport with Students

    ERIC Educational Resources Information Center

    Starcher, Keith

    2011-01-01

    Developing rapport with students is important. Carson (1996) found that when alumni reflected on professors they had encountered 30 years ago, the quality most frequently associated with effective teachers was this: their attitude toward and relationship with students. In this article, the author shares the positive consequences of intentionally…

  17. Extensional hard linkages, eastern Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    McClay, Ken; Khalil, Samir

    1998-06-01

    The Araba Abu Durba area on the eastern margin of the Gulf of Suez exhibits two superb outcrop examples of extensional hard linkages in a rift basin. Here, three large, domino-style, basement-cored, northeast-dipping fault blocks are formed by a series of major northwest-trending normal faults. These are offset by two north-northeast trending sinistral oblique-slip transfer faults that terminate in horsetail normal fault splays. The transfer faults do not extend across the entire rift basin. Detailed mapping and structural analysis show that they developed by breakage of initial low-strain relay ramps along reactivated north-northeast trending basement fabrics between overlapping northwest-trending normal fault segments. Paleostrain analysis of fault-slip indicators shows that both the normal and the sinistral oblique-slip transfer faults were formed synchronously in response to northeast-southwest extension, perpendicular to the main northwest rift trend.

  18. Study optimizes gas lift in Gulf of Suez field

    SciTech Connect

    Abdel-Waly, A.A.; Darwish, T.A.; Osman Salama, A.; El-Naggar, M.

    1996-06-24

    A study using PVT data combined with fluid and multiphase flow correlations optimized gas lift in the Ramadan field, Nubia C, oil wells, in the Gulf of Suez. Selection of appropriate correlations followed by multiphase flow calculations at various points of injection (POI) were the first steps in the study. After determining the POI for each well from actual pressure and temperature surveys, the study constructed lift gas performance curves for each well. Actual and optimum operating conditions were compared to determine the optimal gas lift. The study indicated a net 2,115 bo/d could be gained from implementing its recommendations. The actual net oil gained as a result of this optimization and injected gas reallocation was 2,024 bo/d. The paper discusses the Ramadan field, fluid properties, multiphase flow, production optimization, and results.

  19. Miocene platform-margin reefs, Gulf of Suez, Egypt

    SciTech Connect

    James, N.P.; Rosen, B.; Coniglio, M.

    1988-02-01

    Jebel Abu Shaar is a completely dolomitized carbonate platform atop a crystalline basement horst on the western side of the Gulf of Suez. Margins of the platform, where not removed by synsedimentary faulting, are formed by well-developed coral reefs. The massive reef carbonates consistently illustrate two stages of growth: a basal paucispecific unit of branching coral bafflestone, mostly Stylophora and a thicker upper unit of diverse coral framestone, dominated by faviids. A deep-water, slope-parallel biostrome of ahermatypic corals, dominated by Dendrophyllia and containing numerous Balanophyllia and Madracis, is present 10 km north of Abu Shaar. Corals are well cemented by numerous rinds of marine cement which is overlain by geopetal internal sediment containing planktonic foraminifers and pteropods.

  20. Transfer zones with en echelon faulting at the northern end of the Suez Rift

    NASA Astrophysics Data System (ADS)

    Moustafa, A. R.; Ashour-Abdallah, A. M.

    1992-06-01

    Detailed field mapping of the central part of the area between the northern end of the Suez rift to the Nile Valley (Cairo-Suez area) shows that the Eocene to Miocene rocks are affected by E-W elongated belts of left-stepped en echelon normal faults. These belts act as transfer zones between NW oriented normal faults synchronous with faults of the same trend in the Suez rift. Individual faults within the en echelon fault belts are oriented E-W to WNW and dip in the same direction as the linked NW faults. Step faulting or horsts and grabens are two possible fault arrangements in the transfer zones depending on the geometry of the linked faults. The linked faults and the transfer zones are joined together in zigzag fault belts that extend northwest-ward from the northern part of the Suez rift into the Cairo-Suez area and possibly further northwestward. A substantial amount of the throw of the NW faults of the Suez rift is transferred northwestward by these zigzag fault belts. The throw generally decreases northwestward away from the rift. The en echelon fault belts were probably formed by right-lateral divergent wrenching on E-W oriented, deep-seated, preexisting faults. This right-lateral divergent wrenching is kinematically related to the dip-slip movement on the linked, NW oriented, normal faults.

  1. Cost estimate for a proposed GDF Suez LNG testing program

    SciTech Connect

    Blanchat, Thomas K.; Brady, Patrick Dennis; Jernigan, Dann A.; Luketa, Anay Josephine; Nissen, Mark R.; Lopez, Carlos; Vermillion, Nancy; Hightower, Marion Michael

    2014-02-01

    At the request of GDF Suez, a Rough Order of Magnitude (ROM) cost estimate was prepared for the design, construction, testing, and data analysis for an experimental series of large-scale (Liquefied Natural Gas) LNG spills on land and water that would result in the largest pool fires and vapor dispersion events ever conducted. Due to the expected cost of this large, multi-year program, the authors utilized Sandia's structured cost estimating methodology. This methodology insures that the efforts identified can be performed for the cost proposed at a plus or minus 30 percent confidence. The scale of the LNG spill, fire, and vapor dispersion tests proposed by GDF could produce hazard distances and testing safety issues that need to be fully explored. Based on our evaluations, Sandia can utilize much of our existing fire testing infrastructure for the large fire tests and some small dispersion tests (with some modifications) in Albuquerque, but we propose to develop a new dispersion testing site at our remote test area in Nevada because of the large hazard distances. While this might impact some testing logistics, the safety aspects warrant this approach. In addition, we have included a proposal to study cryogenic liquid spills on water and subsequent vaporization in the presence of waves. Sandia is working with DOE on applications that provide infrastructure pertinent to wave production. We present an approach to conduct repeatable wave/spill interaction testing that could utilize such infrastructure.

  2. Miocene platform-margin reefs, Gulf of Suez, Egypt

    SciTech Connect

    Noel, J.P.; Rosen, B.; Coniglio, M.

    1988-01-01

    Jebel Abu Shaar is a completely dolomitized carbonate platform atop a crystalline basement horst on the western side of the Gulf of Suez. Margins of the platform, where not removed by synsedimentary faulting, are formed by well-developed coral reefs. The massive reef carbonates consistently illustrate two stages of growth: a basal paucispecific unit of branching coral bafflestone, mostly Stylophora and a thicker upper unit of diverse coral framestone, dominated by faviids. In the upper unit, the reef crest is massive columnar Porites and less common Caulastrea framestone. The back-reef is a framestone of diverse faviids, mainly Montastrea Favites, and Tarbellastrea, and interbedded reef-flat rhodolite rudstones. The back-reef and reef-flat facies grade onshelf into Stylophora bafflestone biostromers and faviid bioherms. The reef front is a shallow to intermediate depth zone of numerous and diverse faviids, dominated by Montastrea and Acanthastrea framestones, bioclastic sands, and hardgrounds. Deeper zones are mostly small Acanthastrea mounds or rhodolite/bivalve rudstones with scattered faviids and Acanthastrea. Synsedimentary lithification, internal sedimentationm, and bioerosion prevail throughout. A deep-water, slope-parallel biostrome of ahermatypic corals, dominated by Dendrophyllia and containing numerous Balanophyllia and Madracis, is present 10 km north of Abu Shaar. Corals are well cemented by numerous rinds of marine cement which is overlain by geopetal internal sediment containing planktonic foraminifers and pteropods.

  3. Oil window in the Gulf of Suez basin, Egypt

    SciTech Connect

    Shahin, A.N. )

    1988-08-01

    Petroleum in the Gulf of Suez is multisourced mainly by restricted marine Cretaceous to Eocene beds. The Campanian carbonates of the Sudr Formation and the Turonian shales of the Abu Qada Formation are high-quality sources. Other proven sources are carbonate and shale intervals within other sub-Miocene formations. Geothermal modeling calibrated by maturation measurements suggests that the organic-rich lower Miocene marls may not be mature enough to expel hydrocarbons north of the Morgan-Amal fields area but are mature to the south. This could be related mainly to a gradual increase in thermal gradient from north to south (20-55{degree}C/km). A few anomalies do exist, however. Thermal gradients are generally higher in areas where oil accumulated. The depth of peak generation ranges between 5,200 m to the north and 3,300 m to the south. The geographic variations in heat flow, maturation depths, and age of source rocks are not reflected in the timing of hydrocarbon migration. During the middle Miocene, a short-lived salinity crisis resulted in the deposition of massive thick evaporites that form the ultimate seal in the Gulf. The accompanying rapid burial of the underlying sub-Miocene potential source intervals caused them all to sequentially enter the oil window, within a very short time, soon after the evaporites accumulated. This timing was perfect for hydrocarbon preservation: after seal deposition and major disturbing regional tectonic events. The almost simultaneous migration from all the source beds resulted in mixed multisourced hydrocarbon accumulations.

  4. 77 FR 39689 - Application To Export Electric Energy; IPR-GDF SUEZ Energy Marketing North America, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ...IPR-GDF SUEZ Energy Marketing North America, Inc. (GSEMNA) has applied for authority to transmit electric energy from the United States to Mexico pursuant to section 202(e) of the Federal Power Act...

  5. Gupco's experience in treating Gulf of Suez seawater for waterflooding the El Morgan oil field

    SciTech Connect

    El-Hattab, M.I.

    1982-07-01

    Pressure maintenance by waterflooding in some reservoirs may be considered essential for satisfactory oil recovery. The main objective of waterflooding is to place water into a rock formation at both the desired rate and pressure with minimal expense and trouble. This objective, however, cannot be achieved unless this water has certain characteristics. The water, therefore, should be treated and conditioned before injection. This study addresses the treatment phases adopted to improve seawater quality before injection, and to control problems associated with untreated seawater. Also discussed are GUPCO'S (Gulf of Suez Petroleum Co.) experience in seawaterfloods, problems encountered, and corrective actions taken to overcome these problems. The chemical treatment programs adopted are presented along with final conclusions and recommendations that can be applied to similar floods in Egypt with (Gulf of Suez) GOS. 47 refs.

  6. Phytoplankton variability in relation to some environmental factors in the eastern coast of Suez Gulf, Egypt.

    PubMed

    Nassar, Mohamed Z; El-Din, Nihal G Shams; Gharib, Samiha M

    2015-10-01

    Water samples were seasonally collected from 12 stations of the eastern coast of Suez Gulf during autumn of 2012 and winter, spring, and summer of 2013 in order to investigate phytoplankton community structure in relation to some physicochemical parameters. The study area harbored a diversified phytoplankton community (138 species), belonging to 67 genera. Four algal groups were represented and classified as Bacillariophyceae (90 species), Dinophyceae (28 species), Cyanophyceae (16 species), and Chlorophyceae (4 species). The results indicated a relative high occurrence of some species namely.; Pleurotaenium trabecula of green algae; Chaetoceros lorenzianus, Proboscia alata var. gracillima, Pseudosolenia calcar-avis, and Pseudo-nitzschia pungens of diatoms; Trichodesmium erythraeum and Pseudoanabaena limnetica of cyanophytes. Most of other algal species were fairly distributed at the selected stations of the study area. The total abundance of phytoplankton was relatively low (average of 2989unit/L) in the eastern coast of Suez Gulf, as compared its western coast and the northern part of the Red Sea. The diversity of phytoplankton species was relatively high (2.35-3.82nats) with an annual average of 3.22nats in the present study. The results concluded that most of eastern coast of Suez Gulf is still healthy, relatively unpolluted, and oligotrophic area, which is clearly achieved by the low values of dissolved phosphate (0.025-0.3?M), nitrate (0.18-1.26?M), and dissolved ammonium (0.81-5.36?M). Even if the occurrence of potentially harmful algae species was low, the study area should be monitored continuously. The dissolved oxygen ranged between 1.77 and 8.41mg/L and pH values between 7.6 and 8.41. The multiple regression analysis showed that the dissolved nitrate and pH values were the most effective factors that controlled the seasonal fluctuations of phytoplankton along the eastern coast of Suez Gulf during 2012-2013. PMID:26407862

  7. Risk assessment during transport of radioactive materials through the Suez Canal

    NASA Astrophysics Data System (ADS)

    Sabek, M. G.; El-Shinawy, R. M. K.; Gomaa, M.

    1997-03-01

    In this paper a study for risk assessment of the impact of transporting radioactive materials, during the period 1986-1992, through the Suez Canal of Egypt is given. The code RADTRAN-IV was used for this study. The results of the code, for a normal case, show that the transportation of low activity materials such as uranium (U 3O 8) represent the main items that contribute significantly to the collective dose within the Suez Canal area (Port-Said, Ismailia and Suez). The values of the annual collective dose due to transportation of all radionuclide materials was found to be at a maximum in Suez town and is equal to 5.04 × 10 -8 Man-Sv for the whole populations. If we only consider the workder at the harbour (estimated to be 50 persons), the value of the annual collective dose is about 3.33 × 10 -4 Man-Sv. These values are less than the exemption value of 1 Man-Sv recommended by the IAEA. For the accident case, the following pathways are considered by the code: ground-shine, direct inhalation, inhalation of resuspended material and cloud-shine. The total values of the estimated risks for each radionuclide material are presented in table form and, in addition, health effects (genetic effects, GE, and latent cancer fatality), LCF) are discussed. The calculated values of the radiological risks are very low for the three towns, showing that no radiation-induced early deaths are to be expected.

  8. Physicians build less rapport with obese patients

    PubMed Central

    Gudzune, Kimberly A.; Beach, Mary Catherine; Roter, Debra L.; Cooper, Lisa A.

    2013-01-01

    Objective Physicians’ negative attitudes towards patients with obesity are well documented. Whether or how these beliefs may affect patient-physician communication is unknown. We aimed to describe the relationship between patient BMI and physician communication behaviors (biomedical, psychosocial/lifestyle, and rapport building) during typical outpatient primary care visits. Design and Methods Using audio-recorded outpatient encounters from 39 urban PCPs and 208 of their patients, we examined the frequency of communication behaviors using the Roter Interaction Analysis System. The independent variable was measured patient BMI and dependent variables were communication behaviors by the PCP within the biomedical, psychosocial/lifestyle, and rapport building domains. We performed a cross-sectional analysis using multilevel Poisson regression models to evaluate the association between BMI and physician communication. Results PCPs demonstrated less emotional rapport with overweight and obese patients (IRR 0.65, 95%CI 0.48–0.88, p=0.01; IRR 0.69, 95%CI 0.58–0.82, p<0.01, respectively) than for normal weight patients. We found no differences in PCPs’ biomedical or psychosocial/lifestyle communication by patient BMI. Conclusions Our findings raise the concern that low levels of emotional rapport in primary care visits with overweight and obese patients may weaken the patient-physician relationship, diminish patients’ adherence to recommendations, and decrease the effectiveness of behavior change counseling. PMID:23512862

  9. Synrift sedimentation in the Gulf of Suez rift controlled by eustatic sea level variations

    SciTech Connect

    Perry, S.K.; Schamel, S.

    1985-01-01

    Laterally persistent stratigraphic variations in the southern Gulf of Suez rift indicate that eustatic variations in sea level predominate over local tectonic effects in controlling Neogene basin-fill sedimentation. Low sea level allows extensive erosion of tilt-block crests and rift shoulders, sending clastic aprons into the intervening subbasins and allowing evaporite deposition. High sea level minimizes clastic input, allowing marls and shales to build up off structure and reefs to form on and around tilt blocks. Thus variations in sediment character indicate relative sea level. Early rifting events in the upper Oligocene are marked by deposition of continental red beds. Overlying lowest Miocene clastics and evaporites are cut by a lower Burdigalian unconformity, indicating a minor transgression in the Aquitanian. Above a disconformity, laterally varying clastics and evaporites suggest regression followed by intermittent shallow-water conditions. A higher unconformity is overlain by thick cyclic evaporites representing periodic flooding and drying of the rift, a result of sea level remaining close to the height of the Suez sill to the north. A major Messinian unconformity cuts the section, indicating major regression, and is overlain by largely clastic sediments of both continental and marine affinities, showing rapid sea level fluctuations. Regional synrift sedimentation has been controlled more by eustatic sea level change, modified by the Suez sill to the north, than by tectonic movements within the rift.

  10. Evaluation of poly-aromatic hydrocarbons (PAHs) in the aquatic species of Suez Gulf water along El-Sokhna area to the Suez refineries.

    PubMed

    Ali, Nabila A; Ahmed, Omayma E; Doheim, Mamdouh M

    2014-02-01

    The Egyptian Red Sea environment especially along El-Sokhna area to the Suez refineries (Suez) is severely contaminated with organic compounds, as well as overfishing. This may be well contributory to recent serious declines in fish stocks. Fish embryos are also particularly vulnerable to oil exposure, even at extremely low concentrations of less than one part per billion. Consequently, even traces of oil pollution at levels often considered safe for wildlife can cause severe damage to fish. Sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated in ten fish species of aquatic species by high performance liquid chromatography (HPLC). The compositions of PAHs determined in all samples were measured in order to use them as chemical markers for identifying different sources of PAH pollutants in the studied region. The total content of these16 PAHs ranged from 399.616 up to 67,631.779 ng/g wet weight. The data show that these values are considered to be alarmingly high enough to cause lethal toxicity effect by accumulation. All studied aquatic species samples are characterized by relatively high concentrations of the six-membered ring PAHs. The origin of PAHs in the collected samples is either petrogenic, biogenic, or mixed petrogenic and biogenic. PMID:24092254

  11. Now It's Personal: Antecedents and Outcomes of Rapport between Business Faculty and Their Students

    ERIC Educational Resources Information Center

    Granitz, Neil A.; Koernig, Stephen K.; Harich, Katrin R.

    2009-01-01

    "Rapport" refers to when two people "click." Although business education researchers have begun to study rapport, past research has principally focused on students' perceptions of rapport, whereas faculty's perceptions of rapport have never been studied or contrasted with those of students. Understanding this is critical as rapport between faculty…

  12. Pattern of Blood Stream Infections within Neonatal Intensive Care Unit, Suez Canal University Hospital, Ismailia, Egypt

    PubMed Central

    Kishk, Rania Mohammed; Mandour, Mohamed Fouad; Farghaly, Rasha Mohamed; Ibrahim, Ahmed; Nemr, Nader Attia

    2014-01-01

    Introduction. Blood stream infection (BSI) is a common problem of newborn in neonatal intensive care units (NICUs). Monitoring neonatal infections is increasingly regarded as an important contributor to safe and high-quality healthcare. It results in high mortality rate and serious complications. So, our aim was to determine the incidence and the pattern of BSIs in the NICU of Suez Canal University Hospital, Egypt, and to determine its impact on hospitalization, mortality, and morbidity. Methods. This study was a prospective one in which all neonates admitted to the NICUs in Suez Canal University hospital between January, 2013 and June 2013 were enrolled. Blood stream infections were monitored prospectively. The health care associated infection rate, mortality rate, causative organism, and risk factors were studied. Results. A total of 317 neonates were admitted to the NICU with a mortality rate of 36.0%. During this study period, 115/317 (36.3%) developed clinical signs of sepsis and were confirmed as BSIs by blood culture in only 90 neonates with 97 isolates. The total mean length of stay was significantly longer among infected than noninfected neonates (34.5 ± 18.3 and 10.8 ± 9.9 days, resp., P value < 0.001). The overall mortality rates among infected and noninfected neonates were 38.9% and 34.8%, respectively, with a significant difference. Klebsiella spp. were the most common pathogen (27.8%) followed by Pseudomonas (21.6%) and Staphylococcus aureus (15.4%). Conclusion. The rate of BSIs in NICU at Suez Canal University Hospital was relatively high with high mortality rate (36.0%). PMID:25389439

  13. October field: The latest giant under development in Egypt's Gulf of Suez

    SciTech Connect

    Lelek, J.J.; Abdine, A.S. )

    1990-09-01

    October field, the third largest oil field in Egypt, produced 378 MMBO from its discovery in 1977 until January 1990. It is the northernmost giant oil field in the Gulf of Suez Rift basin. Twenty wells from five platforms in approximately 190 ft (58 m) of water currently drain over 3,238 ha. Recent successful field extensions demonstrate the viability of continuing exploration in this oil-rich area. This structurally trapped field is a complex of rotated fault blocks typical of rift basins worldwide. A northwest-trending normal fault with an approximate throw of 1,220 m has trapped an 335-m oil column on the upthrown eastern side. On the upthrown side, the Carboniferous through Oligocene prerift section dips gently to the northeast and is unconformably overlain by generally flat Miocene to Holocene clastics, carbonates, and evaporites. Severe multiple problems result from thick Miocene evaporites hampering seismic definition of the highly productive prerift section. These same evaporites serve as the ultimate seal in October field and throughout the Gulf of Suez. Although four layers are productive, approximately 95% of field reserves are within Carboniferous to Lower Cretaceous massive Nubia Sandstones. The remaining reserves are in more stratified Upper Cretaceous sandstones, basal Miocene rift-fill Nukhul Formation clastics, and a Lower Miocene clastic in the upper Rudeis Formation. Several distinct reservoir accumulations exist, with the deepest and most significant original oil-water contact at {minus}10,670 ft subsea. October field oil gravities range from 14 to 34{degree} API, with an initial solution GOR of 134 to 474 SCF/STB. The hydrocarbon source for all October field oil as well as most Gulf of Suez oil is believed to be the Campanian Brown Limestone Member of the Sudr Formation. Average reservoir parameters for the Nubia Formation are 16% porosity, 236 md permeability, 137 m net pay thickness, and 5,506 psi original reservoir pressure.

  14. Neogene tectono-stratigraphic events in Gulf of Suez rift area, Egypt

    SciTech Connect

    Evans, A.L.

    1987-05-01

    Micropaleontologic and sedimentologic studies of Miocene outcrop and borehole sections from the flanks and axial trough of the Suez rift have documented five major tectono-stratigraphic events, or hiatuses, during the Neogene. The first Neogene hiatus spans the late(.) Oligocene to earliest Miocene and separates Miocene from pre-Miocene strata throughout the Gulf of Suez. This erosional event resulted from both low global sea levels in the Oligocene and the initiation of Suez rifting. A second hiatus, from 21 to 19(.) Ma, separates the poorly dated shallow marine Nukhul formation from overlying middle Burdigalian and younger (NN3-NN5) upper bathyal shales of the Rudeis Formation. This hiatus resulted from both low early Burdigalian sea levels and increased rift-related tectonism. A third major event occurs within the Rudeis around 16 Ma (N7, NN4). This mid-Clysmic event of Garfunkel and Bartove is characterized by accelerated uplift of the rift margins and subsidence of the axial trough. Local unconformities are seen over paleohighs, while coarse clastics are deposited in more basinal areas in submarine fans and turbidites. A fourth hiatus at 14 to 13 Ma (N10-N11) separates the middle Miocene (N9) Kareem Formation from the overlying Belayim Formation evaporites. This hiatus may correlate with the initiation of rifting along the Dead Sea-Aqaba system. The fifth Neogene event is a tectonic pulse in the early (.) Pliocene that further rotated many tilted fault blocks. This event is roughly synchronous with the initiation of Red Sea sea-floor spreading and accelerated sinistral motion along the Dead Sea transform at approx. 5 Ma.

  15. Examining the positive effects of rapport building: when and why does rapport building benefit adult eyewitness memory?

    PubMed

    Kieckhaefer, Jenna Mitchell; Vallano, Jonathan Patrick; Schreiber Compo, Nadja

    2014-01-01

    Most investigative interviewing protocols recommend building rapport with cooperative adult witnesses to increase the accuracy of their reports. Although a few recent studies support the benefits of rapport building on adult witness recall, no study has examined whether the timing of rapport in relation to post-event misinformation affects recall accuracy, and whether these effects are related to witness anxiety levels throughout the interview. The present study provided two hundred and thirty-three undergraduates with a videotaped mock crime followed by building high or low rapport either before or after they received post-event misinformation. All witnesses were then interviewed about the mock crime. Results indicated that high rapport before misinformation increased the amount of accurate information reported in a subsequent witness interview compared to low rapport. However, these recall benefits were not due to a reduction in anxiety. Theoretical implications and practical recommendations for police interviewing practices are discussed. PMID:24304449

  16. Depositional setting and hydrocarbon source potential of the Miocene Gulf of Suez syn-rift evaporites

    SciTech Connect

    Richardson, M.; Arthur, M.A.; Quinn, J.S.; Whelan, J.K.; Katz, B.J. )

    1988-08-01

    The Red Sea rift basin and its northern continuation, the Gulf of Suez, has experienced continuous deposition of marine evaporites throughout much of its development from the early Miocene to the Pliocene resulting in the accumulation of up to 5 km of evaporite strata in the rift. In this paper, the geologic history of these evaporites are discussed, along with their petroleum source rock potential. The authors hypothesize that rapid deposition of organic matter occurred during episodic storms and freshening events in which a less saline surface layer developed.

  17. Oil prospect of the Gulf of Suez, Egypt - a case study

    SciTech Connect

    Elzarka, M.H.; Mostafa, A.R. )

    1988-01-01

    Four groups of rocks, having more than 0.5% of organic carbon are defined within the subsurface section of Rahmi area, Gulf of Suez. The deduced types of indigenous kerogen are: algal-amorphous, inertinite-woody, and herbaceous. The algal-amorphous kerogen of Rudeis/Nukhul Formations (Lower Miocene), Eocene and pre-Eocene rocks is recognized as being oil prone, that is having high capacity for generating oil. The application of hydrocarbon liquid window concept shows that the LOM values fall within the range from 8.6 to 10.8, and the thermal alteration index for the different units is not extended into oil generation window, where it ranges from immature (Kareem Formation-Lower Miocene), to moderately mature (Paleocene), to the beginning of the thermal phase of oil generation (Senonian). The vitrinite reflectance values indicate a low level of thermal maturity. The formational temperatures increase towards the depocentral part of the basin and eastwards to the present Gulf of Suez. The thermal maturity index increases towards ancient stratigraphic units. The study of organic richness, quality and maturity revealed that, where the Nukhul, Eocene and Senonian rocks are buried deeper in the study area, would have been excellent source rocks for oil.

  18. Structures and sequence stratigraphy of the Miocene successions, southwestern Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Abd El Naby, Ahmed; Abdel-Rahman, Ahmed; Abd El-Aal, Mohamed; Alhamshry, Asmaa

    2016-05-01

    The subsurface structural evolution, facies changes and sequence stratigraphic interpretations of the Miocene successions of the southwestern part of the Gulf of Suez, Egypt, were studied by seismic reflection data of Twenty seven 3D seismic sections supported by the composite, velocity and vertical seismic profiles (VSP) logs of eight wells. Among them five sections and two geoseismic cross sections were selected to reveal the structural framework and depositional history of the study area. The analysis of depth-structure contour maps revealed that the Miocene strata are dissected by two major faults trends: The NW-SE trending faults (Clysmic trend) and the NE-SW trending cross faults running nearly perpendicular to the Clysmic faults. The facies changes of the syn-depositional Miocene units are controlled by the structural framework of the southern part of the Gulf of Suez being evolving diapiric structure of South Gharib Formation. The Miocene units are subdivided into two major 3rd order depositional sequences: S1 and S2.

  19. Structural evolution of the southern transfer zone of the Gulf of Suez rift, Egypt

    NASA Astrophysics Data System (ADS)

    Abd-Allah, Ali M. A.; Abdel Aal, Mohamed H.; El-Said, Mohamed M.; Abd El-Naby, Ahmed

    2014-08-01

    We present a detailed study about the initiation and reactivations of Zeit-El Tor transfer zone, south Gulf of Suez rift, and its structural setting and tectonic evolution with respect to the Cretaceous-Cenozoic tectonic movements in North Egyptian margin. NE trending zone of opposed-dipping faults (22 km wide) has transferred the NE and SW rotations of the sub-basins in central and south Gulf of Suez rift, respectively. The evolution of this zone started by reactivation of the NE oriented late Neoproterozoic fractures that controlled the occurrence of Dokhan Volcanics in the rift shoulders. Later, the Syrian Arc contraction reactivated these fractures by a sinistral transpression during the Late Cretaceous-Eocene time. N64°E extension of the Oligo-Miocene rift reactivated the NE fractures by a sinistral transtension. During this rifting, the NE trending faults forming the transfer zone were more active than the rift-bounding faults; the Upper Cretaceous reverse faults in the blocks lying between these NE trending faults were rotated; and drape-related reverse faults and the positive flower structures were formed. Tectonic inversion from contraction to extension controlled the distribution and thickness of the Upper Cretaceous-Miocene rocks.

  20. [The corvette "Nordstjernen's" voyage to the opening of the Suez Canal--naval medicine in 1869].

    PubMed

    Ongre, Aksel; Pettersen, Jan Sommerfelt; Munch, Johan Storm

    2002-06-30

    When the Norwegian corvette Nordstjernen was in the North Sea bound for Port Said to be present at the opening of the Suez Canal on 17 November 1869, an officer suffered a rupture of m. triceps brachii when he was drawn into the machinery during a storm. He was put ashore in Harwich; four days after the injury he was hospitalized in Colchester. The voyage was eventful in other ways too. Another officer died from typhoid fever in Ismailia. On the Swedish frigate Vanadis, also present at the opening of the Suez Canal, one of the doctors died from lung infection and was buried in Smyrna; a twelve-feet high column of white marble was taken from the ruins of Aesculap's temple and put on his grave. Denmark was represented by the frigate Sjaelland. During a storm in the North Sea, one seaman fell down on the deck from the foresail yard and suffered contusions and a fracture of the left clavicle. These cases illustrate challenges that faced our ancestors. The accident happened when the ship was in the Netherlands sector of the North Sea as we know it today. Today the Coast Guard could have arranged transport by helicopter and hospitalized the patient in about two hours. PMID:12555606

  1. Relationship between sediment morphology and oil pollution along the Suez Canal beaches, Egypt

    SciTech Connect

    Barakat, M.A.K.; Shimy, T.M.; Mostafa, Y.M.

    1996-10-01

    In this study, marine surface sediments are collected from nine locations along the Suez Canal in order to investigate the relationship between the morphology of sands in the studied beaches and pollution by oil. Basically, the studied samples were analyzed by three techniques: grains-size analysis, microscopic examination, and gas chromatographic (GC) analysis. This study concluded that medium sand is the major class represented in the studied marine sediments. Pollution in these sand grains increases in the irregular grains more so than in the more rounded grains. Also, deep surface points, pitting, and fissures are considered to be good sites to precipitate oil contamination. Also, the presence of iron oxides may be taken as evidence for tanker ballast washings. The heavy fraction (zircon) shows more contamination than the light fraction (quartz) in these samples. Finally, GC profiles have shown two types of samples: one typical of weathered or highly weathered crude oil patterns and the other for samples with very highly weathered profiles. The relationship obtained between morphology studies and both oil content and GC chromatogram profiles indicates that all of the studied locations are suffering from pollution of oil that is spilled while shipping petroleum through the Suez Canal.

  2. Integrated geophysical analysis of subsalt imaging problems in the Gulf of Suez

    SciTech Connect

    Lewis, G.G.; Young, K.T.

    1995-12-31

    An integrated geophysical approach resulted in improved images of subsalt reflectors in the Gulf of Suez. These improvements resulted from an improved understanding of subsalt imaging problems in the Gulf. This understanding allowed us to develop processing techniques which limited the effect of these imaging problems. We analyzed the impact of the following subsalt imaging problems on Gulf of Suez seismic data: (1) strong contamination by multiples, (2) weak subsalt reflection strength, and (3) strong raypath distortion. Seismic modeling was used to simulate these effects for two study areas. In both areas the exploration target is hydrocarbons trapped in tilted extensional fault blocks in the prevaporite section. In the first area, the evaporite section is predominantly horizontally layered and there is a hard water bottom. The major imaging problems in this setting are strong water - bottom related multiples and weak reflection strength. We developed a dip - dependent scaling procedure which enhanced preevaporite reflections for both synthetic and real data. In the second area, there has been significant deformation of the evaporite section to form salt walls. In this setting, raypath distortion is the dominant imaging problem, although both of the other factors are also significant. Here we used prestack depth migration to image preevaporite fault blocks which had not been imaged using other techniques.

  3. Professor-Student Rapport Scale: Six Items Predict Student Outcomes

    ERIC Educational Resources Information Center

    Wilson, Janie H.; Ryan, Rebecca G.

    2013-01-01

    Rapport between students and teachers leads to numerous positive student outcomes, including attitudes toward the teacher and course, student motivation, and perceived learning. The recent development of a Professor-Student Rapport scale offers assessment of this construct. However, a Cronbach's [alpha] of 0.96 indicated item redundancy, and the…

  4. Neuro-Linguistic Programming, Matching Sensory Predicates, and Rapport.

    ERIC Educational Resources Information Center

    Schmedlen, George W.; And Others

    A key task for the therapist in psychotherapy is to build trust and rapport with the client. Neuro-Linguistic Programming (NLP) practitioners believe that matching the sensory modality (representational system) of a client's predicates (verbs, adverbs, and adjectives) improves rapport. In this study, 16 volunteer subjects participated in two…

  5. Professor-Student Rapport Scale: Six Items Predict Student Outcomes

    ERIC Educational Resources Information Center

    Wilson, Janie H.; Ryan, Rebecca G.

    2013-01-01

    Rapport between students and teachers leads to numerous positive student outcomes, including attitudes toward the teacher and course, student motivation, and perceived learning. The recent development of a Professor-Student Rapport scale offers assessment of this construct. However, a Cronbach's [alpha] of 0.96 indicated item redundancy, and the

  6. Rapport Management of International Teaching Assistants in Their Teaching

    ERIC Educational Resources Information Center

    Zhang, Yuan

    2013-01-01

    The current study adopts Spencer-Oatey's theory of rapport management as the main framework, and examines the IT A participants' perceptions of their management of rapport, i.e. social relationship, with their American undergraduates, which are also compared with perceptions of American counterparts, including American professor and ATA…

  7. Crustal and uppermost mantle structure beneath the continental rifting area of the Gulf of Suez from earthquake tomography

    NASA Astrophysics Data System (ADS)

    El Khrepy, Sami; Koulakov, Ivan; Al-Arifi, Nassir

    2016-02-01

    Suez rift is one of the active seismic zones in the northward continuation of the Red Sea, as indicated by recent earthquake records from the Egyptian National Seismological Network (ENSN). We present a new model of P and S wave velocities in the crust and uppermost mantle beneath the Gulf of Suez and surrounding areas, including the northern portion of the Red Sea. Using the records from 94 seismic stations, we analyzed ~ 66,000 P and ~ 17,000 S wave arrival times from 9700 events. The travel time tomography inversion was performed using the iterative LOTOS code. The spatial resolutions of the derived models were assessed using several synthetic tests. The most prominent anomaly is a sharp high-velocity anomaly beneath the Red Sea, which is observed in both the P and S models at all depth intervals. We interpret this anomaly to be oceanic crust that was formed through extension associated with a dispersed system of spreading centers. Beneath the Gulf of Suez, the upper and middle crusts appear to be strongly heterogeneous and are dominated by low-velocity anomalies, indicative of the continental nature of the crusts. In contrast, at a depth of 30 km, we observe a prominent high-velocity anomaly along Gulf of Suez, which is interpreted to be the result of crustal thinning associated with extension between the Sinai block and the African Plate. The thickness of the crust beneath the rift is estimated to be approximately 25 km, whereas that in the surrounding areas appears to be 30-35 km. In the northwestern part of the area, we observe a low-velocity zone in the middle and lower crusts that coincide with intense seismicity and a well-developed system of recent faults on the surface. This region may mark a possible area of northward propagation of the Suez Rift zone.

  8. Women in parole: respect and rapport.

    PubMed

    Ireland, Connie; Berg, Bruce

    2008-08-01

    Although the number of females in law enforcement has increased in recent years, research suggests that the uniquely gendered contributions of females are minimized in favor of traditional modes of law enforcement, emphasizing physical presence, authoritative commands, and demonstrative control. This research examines women in parole, using in-depth interviews with a small convenience sample of female parole agents in California. Participants discussed their experiences as parole agents from the perspective of women in a predominantly male occupation. Overwhelmingly, they emphasized traditionally associated female traits of intuition, verbal communication, and relationships, over physical tactics. Participants emphasized the importance of building respect and rapport with parolees in multiple contexts, including in the parolees' homes, with the families of parolees, and at parolees' places of employment. Participants suggested that this approach ensures their personal safety and enhances parolee compliance, especially when considering their subjective account of experiences by male parole agents. PMID:17991901

  9. Penetrating evaporites - new information from old seismic data in Suez Rift, Egypt

    SciTech Connect

    Perry, S.K.; Gawarecki, S.L.; Schamel, S.

    1987-05-01

    Structures in the prerift sediments, Gulf of Suez, are of primary interest for petroleum exploration. However, the overlying thick blanket of Miocene synrift evaporites severely limits resolution of deep structures in seismic reflection lines. A technique for maximizing accuracy of prerift maps and sections is illustrated by examples from the south-central Gulf of Suez. Preliminary structural maps of prerift units are generated from limited well data, good seismically derived maps of the base evaporite, and fragmentary deep seismic data. Through rigorous application of conventional cross section balancing techniques and geometric rules for listric normal fault-block rotation, trial cross sections are constructed. Construction of trial cross sections relies heavily on the following information from seismic lines: (1) thickness variations of synrift fill; (2) sequence boundaries representing unconformities over buried tilt blocks; (3) dip domains faintly visible beneath Miocene evaporites; and (4) faulting in Miocene sediments in response to deeper normal faults. The integration of well data allows control of seismic interpretation and of depth to prerift rocks. The sections are refined through iteration and are then used in conjunction with areal balancing methods to correct the structure maps. The subsequent serialization of balanced sections results in an internally consistent, geometrically constrained, three-dimensional picture of the basin which best fits all the available data. Important information on prerift structures which results from this technique includes location of normal faults and the magnitude of their throw, attitude of deep tilt blocks, and location of tilt-block terminations. Using this methodology, old prospects can be refined and new plays and prospects generated. These can then be tested by local detailed seismic work or by the drill.

  10. Gulf of Suez-Rift basin stratigraphy: an interplay of subsidence and Eustatic sea level

    SciTech Connect

    Richardson, M.; Arthur, M.A.

    1987-05-01

    The Gulf of Suez and Red Sea rift basin underwent a period of rapid subsidence from the early Miocene to the Pliocene during which time a thick (up to 4 km) series of marine evaporites accumulated within the basin. The evaporitic sequence interfingers with carbonates and clastics over structural highs within and along the margins of the basin. Evaporite deposition was also interrupted basin wide by short periods of normal marine sedimentation. Timing and paleo-oceanographic aspects of evaporite deposition within the rift is controversial. A change over of marine source waters within the basin from the Mediterranean Sea to an opening of the rift to the Indian Ocean occurred sometime between the earliest Messinian and earliest Pliocene. Preliminary data suggests that anhydrites from this evaporite sequence retain original Miocene sea water Sr/sup 87//Sr/sup 86/ values which can be compared to Neogene strontium isotope versus time curves in order to further constrain the age of the nonfossiliferous evaporite group. This, combined with currently accepted biostratigraphies for the normal marine strata, enable us to refine rift stratigraphy in order to examine basin subsidence, evaporite accumulation rates, and the correlation of rift tectonics, sedimentation, and associated paleo-oceanographic events. Initial fragmentation and subsidence propagated from the south to the north in the Gulf of Suez during the Aquitanian to Burdigalian (20-25 Ma), and mixed clastic, carbonate, and evaporitic sediments (Nukhul Formation) up to 700 m thick were deposited in isolated subbasins within the rift. This episode was followed by renewed uplift of the rift shoulders, rapid subsidence, and increased clastic influx (late Rudeis Formation) during the Burdigalian (ca. 20-17 Ma).

  11. Geology and habitat of oil in Ras Budran field, Gulf of Suez, Egypt

    SciTech Connect

    Chowdhary, L.R.; Taha, S.

    1987-10-01

    The Ras Budran structure at the deepest mappable seismic reflector, the top of the Kareem Formation (middle Miocene), is a broad northeast-southwest-trending anticlinal feature with an anomalous strike nearly at right angles to the main Gulf of Suez trend. Oil is produced from three units of Nubian Formation sandstone from a depth of 11,000-12,000 ft (3352-3657 m). The lower unit of Paleozoic age averages 10% porosity and has up to 200 md in-situ permeability. Wells completed in this unit produce up to 2000 BOPD. In contrast, the sands to the upper two units of the Early Cretaceous have 15-20% porosity and up to 700 md permeability. Wells completed in this unit produce 6000-8000 BOPD. The Ras Budran structure was formed primarily during an intra-Rudeis tectonic phase (lower Miocene). Oil migration for accumulation in the structure started in the late Miocene or Pliocene when the Santonian Brown Limestone and the Eocene Thebes Formation, the main source beds in the Gulf of Suez, reached the threshold of oil generation at a burial depth of approximately 10,000 ft (3048 m). At this depth, the organic matter in the source beds had a high transformation ratio (0.10 to 0.15), high yields of C/sub 15+/ soluble organic matter and C/sub 15+/ saturated hydrocarbons, vitrinite reflectance (R/sub 0/) of 0.62%, and a time-temperature index (TTI) value of 15. Oil migration from mature source beds in adjoining lows into low-potential Nubian reservoirs is easily explained by fault planes that acted as conduits for oil migration. 16 figures, 3 tables.

  12. Leishmaniose viscerale et leucemie aigüe lymphoblastique B: quel est le rapport?

    PubMed Central

    El Youssi, Hind; Touaoussa, Aziz; Bergui, Imane; Bougrine, Nawal; Amrani, Moncef Hassani

    2015-01-01

    L'association leishmaniose viscérale et leucémie aigue a été rarement rapportée dans la littérature, cependant le diagnostic concomitant de ces deux entités n'a jamais été rapporté au Maroc. Le lien entre ces deux pathologies n'a pas encore été établi et le traitement n'a pas encore été codifié. Nous rapportons le cas d'un garçon de 12 ans chez qui une leishmaniose viscérale et une leucémie aigue lymphoblastique type B ont été diagnostiquées simultanément. Malgré l'administration d'un traitement antiparasitaire associé à une chimiothérapie l’évolution était marquée par le décès du patient. PMID:26090011

  13. Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae).

    PubMed

    El-Serehy, Hamed A; Al-Rasheid, Khaled A; Ibrahim, Nesreen K; Al-Misned, Fahad A

    2015-11-01

    A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab's carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm. PMID:26587008

  14. L'atteinte vésicale au cours de la neurofibromatose de Von Recklinghausen

    PubMed Central

    Benazzouz, Mohamed Hicham; Hajjad, Tilila; Essatara, Younes; El Sayegh, Hachem; Iken, Ali; Benslimane, Lounis; Nouini, Yassine

    2014-01-01

    La neurofibromatose de type 1 ou maladie de Von Recklinghausen est une maladie génétique autosomique dominante en rapport avec des mutations dans le gène suppresseur de tumeur NF1. L'atteinte uro-génitale au cours de cette maladie est rare et moins de 80 cas ont été rapportés à ce jour dans la littérature mondiale. Les auteurs rapportent un nouveau cas d'atteinte vésicale découverte fortuitement au cours du suivi d'une patiente atteinte de la maladie de Von Recklinghausen. A travers cette observation et une revue de la littérature les auteurs discutent également les difficultés diagnostiques, thérapeutiques ainsi que les modalités de suivi dans cette maladie. PMID:25328590

  15. Geology and habitat of oil in Ras Budran field, Gulf of Suez, Egypt

    SciTech Connect

    Chowdhary, L.R.; Taha, S.

    1987-05-01

    Deminex discovered the Ras Budran oil field in 1978. Discovery well EE 85-1 was drilled in about 140 ft of water, 4 km off the Sinai coast of the Gulf of Suez. Appraisal drilling (EE 85-2, 3, and 4 wells) confirmed the presence of a major field with an estimated 700 million bbl oil in place. The field, developed from three wellhead platforms, went on production in April 1983. To date, 20 development wells have been drilled. The Ras Budran structure at the deepest mappable seismic reflector, top Kareem (middle Miocene), is a broad northeast-southwest-trending anticlinal feature striking nearly at right angles to the main Gulf of Suez trend. At pre-Miocene producing horizons, the structure is complex and consists of a northeast-dipping flank (14-15) broken into several blocks by faults and limited to the south and west by major bounding faults. Oil is produced from three units of Nubian sandstone at a depth of 11,000 to 12,000 ft. The lower unit of Paleozoic age averages 10% porosity and up to 200 md in -situ permeability. The wells completed in this unit produce up to 2000 BOPD. In contrast, the sands of the upper two units of Lower Cretaceous age have a 15-20% porosity and up to 700 md permeability. The wells completed in these units produce 6000-8000 BOPD. The Ras Budran structure was primarily formed during the intra-Rudeis tectonic phase (lower Miocene). Migration of oil for accumulation in Ras Budran started late in the upper Miocene or Pliocene when the Santonian Brown Limestone and the Eocene Thebes Formation, the main source beds in the Gulf, reached the threshold of oil generation at a burial depth of about 10,000 ft (3000 m). At these depths, the organic matter in the source beds have a transformation ratio (0.10 to 0.15), increased yields of C15 + soluble organic matter and C15 + saturated hydrocarbons, a vitrinite reflectance of 0.62%, and a TTI value of 15.

  16. Controls on erosional retreat of the uplifted rift flanks at the Gulf of Suez and northern Red Sea

    NASA Technical Reports Server (NTRS)

    Steckler, Michael S.; Omar, Gomaa I.

    1994-01-01

    The Gulf of Suez and the Red Sea rigts are currently bordered by large asymmetric uplifts that are undergoing erosion. We find that the amount and timing of erosion vary systematically along the strike of the margin and have been controlled by variations in the perift stratigraphy. The perfit strata are compsoed of cliff-forming Eocene-Cretaceous carbonates overlaying the easily eroded Cretaceous-Cambrian 'Nubian' sandstone. This lithologic succession promotes scarp retreat of the sedimentary section, follwed by dissection of the underlying basement. The perift section thins from over 2000 m at the northern end of the rift to less htan 400 m at its junction with the Red Sea. Thus, at the northern part of the Gulf of Suez, the Nubian sandstone is minimally exposed, and the carbonates form a scarp at the rift border fault. Farther south, undercuttin of hte carbonates by erosion of the sandstion has resulted in scarp retreat. The escarpment cuts diagonally away from the border fault andis over 100 km inland from the border fault at the southernmost Gulf of Suez. The amount of retreat varies inversely with the sediment thickness. Exposure and erosion of basement are initiated by the retreate of the escarpment, and the depth of erosion, as indicated by fission track ages, increases with distance from the escarpment. These observations are explained by a model in which erosion along the Gulf of Suez is initiated as rift flank uplift becomes sufficiently large ot expose the friable sandstones. Undercutting the escarpment and exhumation of basement has been propagating northward and westward for at least 20 m.y. The average rate of scarp retreat has been 6 km/m.y. and the along-strike propagation of the erosion has been 12 km/m.y. The diachronous erosion of the rift flanks at the Gulf of Suez highlights the importance of distinguishing between the timing of uplift and of erosion. Both thermochronometric and stratigraphic data primarily indicate the timing of erosion, which may differ significantly form the timing of the uplift that initiates it. They must be interpreted carefully to avoid erroneous conclusions about rift tectonics.

  17. Tectonic and structural setting of the northeastern central Gulf of Suez area using aeromagnetic data

    NASA Astrophysics Data System (ADS)

    Zahra, Hesham Shaker; Nakhla, Adel Mokhles

    2016-03-01

    Cumulative qualitative and quantitative analysis of the filtered regional and residual magnetic components of the northeastern central area of the Gulf of Suez, as well as images of the second vertical derivatives of the reduced to the northern magnetic pole map of the total magnetic intensity field images, supplemented with the available geologic information, enabled the precise delineation of the detailed structural configuration of the basement complex, which consequently illustrated the structural deformational pattern of the overlying sedimentary succession. The basement tectonic map reflects a series of N-S to NNW-SSE oriented belts of high and low basement structures. These structures are interrupted by a set of NE-SW crossing diagonal faults having varying throws and creating promising blocks for exploration. An often remarkable correlation between the reduced to the magnetic pole map and the basement relief map is noted, in particular the outline of various oil fields. A larger number of the tilted fault blocks and basement culminations have been outlined and numerous interesting exploration prospects are indicated, which appear to warrant further follow up investigation.

  18. Carbonate depositional environments and reservoir properties of the Miocene rocks, east Gulf of Suez, Egypt

    SciTech Connect

    Bakarat, M.A.K.; Kholief, M.M.

    1988-08-01

    Miocene carbonate rocks in six surface sections on the eastern side of the Gulf of Suez were carefully studied in the field, petrographically examined, and mineralogically analyzed using SEM and x-ray microanalysis for all elements. In general, reservoir quality of the Miocene carbonates was poor because of original composition and texture. Three different types of porosity were distinguished in the studied Miocene carbonates: primary (intergranular and moldic), secondary (leached), and fracture. Much of the porosity in the Miocene reservoirs is secondary; however, sometimes this secondary porosity may be reduced by compaction and/or precipitation of evaporites in fractures and pores. The authors conclude that the primary porosity of the carbonate rocks in the reef complex was eliminated by lithification and cementation; only secondary porosity remained. This secondary porosity developed in all environments (supratidal, intertidal, and subtidal), but the best porosity developed in the subtidal facies. This high porosity occurs because the dolomites in the subtidal facies are coarser and free from anhydrite cement, whereas in supratidal and intertidal facies the dolomites are finer and their porosity is plugged by secondary anhydrite cement.

  19. Subsurface Structural Imaging Of Esh El Mallaha Area, Gulf Of Suez, Egypt Using Aeromagnetic Data

    NASA Astrophysics Data System (ADS)

    Aboud, E.; Salem, A. S.; El-Bohoty, M. E.; Ushijima, K.

    2003-12-01

    This paper presents a case study on the subsurface structural imaging of Esh El Mallaha area. Esh EL Mallaha area is located on the western flank of the Gulf of Suez and it has a great importance due to its hydrocarbon resources. In 1994 the area was covered by aeromagnetic survey conducted by Aero Service Division, Western Geophysical Company of America. The main object of this work to delineate the subsurface structural framework of the area that may assist in hydrocarbon exploration. A 3D analytic signal technique was applied to the aeromagnetic data. One of the most advantages of the analytic signal is that it produces a maximum value over a 2D magnetic source and as a result it enables more accurate location of the magnetic sources. It is also straight forward to determine the depth to the magnetic contacts using a simple formula derived from the analytic signal. Generally, Esh EL Mallaha area is characterized by two basinal structures taking the direction of the NW-SE parallel to the Red Sea rift. Those two basins are separated by long dike igneous rocks bounded by two major faults and taking the direction of NW-SE.

  20. Rapport Building in Language Instruction: A Microanalysis of the Multiple Resources in Teacher Talk

    ERIC Educational Resources Information Center

    Nguyen, Hanh thi

    2007-01-01

    Current guidelines on teacher--student rapport, while providing helpful suggestions, fail to address the question of how rapport building can be achieved in contextualised classroom interaction in which a balance needs to be reached between rapport and instructional tasks. Using discourse analysis informed by a conversation analytic approach and…

  1. Hydrocarbon potential, structural setting and depositional environments of Hammam Faraun Member of the Belayim Formation, Southern Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Nabawy, Bassem S.; El Sharawy, Mohamed S.

    2015-12-01

    The Middle Miocene Belayim Formation is one of the most prolific formations in the Southern Gulf of Suez. It consists of four members; two members are evaporitic (Baba and Feiran) and the other two members are prospective, mostly clastics (Hammam Faraun and Sidri). The hydrocarbon potential and depositional environment of Hammam Faraun Member, the target of the present study, have been studied in 11 wells distributed in the southern province of the Gulf of Suez. The traditional well log data, as well as the Spectral Gamma-Ray logs 'SGR' and dipmeter data were used to evaluate the petrophysical properties and distribution of the Hammam Faraun Member in the Southern Gulf of Suez. It varies greatly in thickness with the greatest thicknesses in GS 365 (372 ft) and GS 373 (430 ft) fields in the central parts and the thinnest at the basin margins of the studied area at GH376 (65 ft) and Ras El Bahar (67.5 ft) fields. It is composed of clastic rocks, mainly shales and sometimes reef carbonates. The very good petrophysical properties of the studied sequence indicate a good reservoir in some fields with good to very good porosity (13.5 ≤ ∅ ≤ 25.0%). The shale volume of this reservoir sequence is less than 33% and the water saturation is less than 42.3%, while the net-pay thickness is up to 58 ft. The SGR and Pe logs indicate that, the studied rocks were deposited mostly in lagoonal to shallow marine environments, with illite and montmorillonite as dominant clay minerals. The dipmeter data obtained in some wells indicate slightly tilted beds, mostly less than 20° with an overall dip direction towards the SW, which represents the regional dip in the Southern Gulf of Suez. Based on dipmeter data, two major angular unconformities can be detected; one at the top of the sequence, separating it from the overlying South Gharib evaporates, and another one at the base of the sequence, separating it from the underlying Feiran Member.

  2. Preliminary seismicity and focal mechanisms in the southern Gulf of Suez: August 1994 through December 1997

    NASA Astrophysics Data System (ADS)

    Hussein, H. M.; Marzouk, I.; Moustafa, A. R.; Hurukawa, N.

    2006-05-01

    This paper shows an evaluation of the seismic activity in the entrance of the Gulf of Suez using the data recorded by Hurghada Seismological Network (HSN), in the period between August 1994 and December 1997 and represents an extension for the work published by the previous investigators. Hypocentral locations were determined for 180 earthquakes (duration magnitude ranged between 1.6 and 4.3) selected from 300 recorded events. All these events are located with epicentral error and depth error of less than 2 km. The spatial distribution of these earthquakes indicates the presence of three active areas. These are Shadwan Island, Gubal Island and the area adjacent to the southern tip of Sinai Peninsula. Such pattern of activity implies a localization of stress below these areas. The concentration of the stress field in these areas may have been strongly controlled by ductile necking and or intrusion. Composite fault plane solutions were also constructed for each of the three active areas. The data for each area was divided into groups, according to geographical position and uniformity of polarity data. In Shadwan Island, the composite fault plane solution of 15 events shows almost pure dip-slip motion. The composite fault plane solutions in Gubal Island and the area adjacent to the southern tip of Sinai Peninsula indicate a mixed regime of both strike-slip and extensional faulting mechanisms. The stress regime obtained from the fault plane solutions in this study is predominantly NNE-SSW tensional stress field. This result is consistent with the present day stress field, which has a 010° ± 18° orientation. The overall results are correlated with the structural setting of the area known from other sources.

  3. Master's and doctoral theses in family medicine and their publication output, Suez Canal University, Egypt

    PubMed Central

    Nour-Eldein, Hebatallah; Mansour, Nadia M.; Abdulmajeed, Abdulmajeed A.

    2015-01-01

    Background: The completion of a thesis is a significant requirement for both a Master's and a doctorate degree in general practice/family medicine (GP/FM). A postgraduate thesis is a well-planned, time-intensive activity carried out over several years. The quality of the theses can be judged by the proportion of published papers. Objective: This study aimed to describe Master's and doctoral theses in family medicine and their publications between 1982 and 2014. Materials and Methods: GP/FM degree theses were reviewed at the Faculty of Medicine and central Suez Canal libraries. Several characteristics were extracted from each thesis relating to the main researcher, supervisors, themes, and study methods according to predefined criteria. Publications from the theses were described. Results: Over 33 years, 208 theses were completed by 173 GP/FM researchers. The majority of the theses were for Master's degrees (84.1%). Regarding the study design, most of the degree theses were cross-sectional studies (76.9%). The adult population was targeted in 33.7% of research theses. Nonprobability sampling was used in 51%. Rural communities were the setting of research in 43.8%, and primary health center (PHC)-based studies in 59.1%. The Patient category exceeded the other categories (28.4%). Publication from theses started in the second decade of research production. Of the degree theses, 21.6% original articles were published. Only 13.3% of articles from theses were published in PubMed-indexed journals. The researcher was first author in 62.2% of published articles. Conclusion: The production of GP/FM theses and their publications are going to increase. Continuous assessment and planning for GP/FM studies are recommended. PMID:25949959

  4. Marine molluscs as biomonitors for heavy metal levels in the Gulf of Suez, Red Sea

    NASA Astrophysics Data System (ADS)

    Hamed, Mohamed A.; Emara, Ahmed M.

    2006-05-01

    Levels of the heavy metals Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), Iron (Fe) and Manganese (Mn) were determined in coastal water, sediments and soft tissues of the gastropod limpet, Patella caerulea, and the bivalve, Barbatus barbatus, from seven different stations in the western coast of the Gulf of Suez. The concentrations of heavy metals in water ranged between 3.37-4.78, 18.83-21.46, 2.75-3.17, 0.22-0.27, 0.99-1.21, 2.69-3.65, 3.75-4.56 μg L - 1 and 23.82-32.78 mg g - 1 for Cu, Zn, Pb, Cd, Cr, Ni, Mn and Fe, respectively. The corresponding concentration values in the sediments were 8.65-12.16, 51.78-58.06, 36.52-42.15, 3.23-3.98, 9.03-12.75, 34.31-49.63, 3.28-4.56 and 64.20-70.22 μg g - 1 for Cu, Zn, Pb, Cd, Cr, Ni, Mn and Fe, respectively. The highest accumulated metals were Fe, Zn and Mn in both P. caerulea and B. barbatus, while the lowest one was Cd. The accumulation of metals was more pronounced in P. caerulea than B. barbatus. The highest concentrations of all metals in water, sediments and mollusca were recorded at Adabiya harbour north of the Gulf, while the lowest concentrations were recorded at Gabal El-Zeit and Hurghada. Land based activities and ships awaiting berth are the main source of metal pollution in the northern part of the Gulf.

  5. Discipline Alternatives. First, the Rapport--Then, the Rules.

    ERIC Educational Resources Information Center

    Canter, Lee

    1996-01-01

    Classroom discipline methods are changing with the times. Assertive Discipline is a 20-year-old program designed to help teachers successfully manage students' behavior. In the 1990s, it involves building a rapport with students and creating a discipline plan at the same time. The paper details the basic principles of the Assertive Discipline…

  6. Mannerisms of the Elderly and Approaches to Rapport.

    ERIC Educational Resources Information Center

    French, Warren A.; And Others

    1980-01-01

    Many older adults react to old age with empirically identified distinguishable mannerisms. Using these mannerisms, or behavior patterns, as a basis for rapport, gerontologists can: (1) uncover causes of adjustment problems; (2) assess seriousness of problems; and (3) implement counseling suggestions. (Author/JAC)

  7. Reproductive biology of the Suez Canal spider crab Schizophrys aspera (H. Milne Edwards, 1834: Crustacea: Brachyura: Majidae)

    PubMed Central

    El-Serehy, Hamed A.; Al-Rasheid, Khaled A.; Ibrahim, Nesreen K.; Al-Misned, Fahad A.

    2015-01-01

    A reproductive biology study of the spider crab Schizophrys aspera (H. Milne Edwards, 1834) was conducted in the Suez Canal from July 2012 to June 2013. The annual sex ratio (Male:Female) of S. aspera was female biased with values of 1:1.25. Out of the four ovarian development stages of this crab, two stages were observed in the Suez Canal throughout the whole year. The ovigerous crab’s carapace width varied from 28 to 52 mm. This crab species can spawn during most of the year in the canal water, with a peak during late spring and early winter. The fecundity of ovigerous females ranged between 2349 and 13600 eggs with a mean of 5494 ± 1486 eggs. Female crabs that reached sexual maturity exhibited a minimum carapace width varying between 22 and 46 mm, and fifty percentage of all ovigerous females showed a carapace width of 36 mm. PMID:26587008

  8. Ecological Study on Community of Exotic Invasive Seaweed Caulerpa prolifera in Suez Canal and its Associated Macro Invertebrates

    NASA Astrophysics Data System (ADS)

    Gab-Alla, Ali A.-F. A.

    Caulerpa prolifera (Forsskal) Lamouroux, a green alga, widespread in tropical and subtropical seas is now invading species to the Suez Canal during last recent years after 2000; it is widely spread, colonizing its western sandy shore at shallow waters of 1-2 m depth. It has the potential to supplant native vegetation, thereby altering the structure and function of the subtidal marine landscape, supplant seagrass H. stipulacea. According to the present study, based on biometric parameters, the frequency of occurrence, abundance and density analyses, the seaweed C. prolifera is more frequent, abundant and dense in Suez Canal than the seagrass H. stipulacea, which is very rare. Instead C. prolifera forming extended dense meadows with percentage cover nearly 100% m-2 at many sites. This mainly happened; due to the competitive success of C. prolifera which seems to be related to its big size, high density, rapid growth, high efficiency in dim light conditions, high tolerance to severe nutrient limitation and salinity and temperature fluctuations and to the production of toxic secondary metabolites. The presence of these toxic secondary metabolites explains why C. prolifera is avoided by many of macro invertebrates as a habitat or feeding grounds.

  9. Multiphase flowmeter successfully measures three-phase flow at extremely high gas-volume fractions -- Gulf of Suez, Egypt

    SciTech Connect

    Leggett, R.B.; Borling, D.C.; Powers, B.S.; Shehata, K.; Halvorsen, M.

    1998-02-01

    A multiphase flowmeter (MPFM) installed in offshore Egypt has accurately measured three-phase flow in extremely gassy flow conditions. The meter is completely nonintrusive, with no moving parts, requires no flow mixing before measurement, and has no bypass loop to remove gas before multiphase measurement. Flow regimes observed during the field test of this meter ranged from severe slugging to annular flow caused by the dynamics of gas-lift gas in the production stream. Average gas-volume fraction ranged from 93 to 98% during tests conducted on seven wells. The meter was installed in the Gulf of Suez on a well protector platform in the Gulf of Suez Petroleum Co. (Gupco) October field, and was placed in series with a test separator located on a nearby production platform. Wells were individually tested with flow conditions ranging from 1,300 to 4,700 B/D fluid, 2.4 to 3.9 MMscf/D of gas, and water cuts from 1 to 52%. The meter is capable of measuring water cuts up to 100%. Production was routed through both the MPFM and the test separator simultaneously as wells flowed with the assistance of gas-lift gas. The MPFM measured gas and liquid rates to within {+-} 10% of test-separator reference measurement flow rates, and accomplished this at gas-volume fractions from 93 to 96%. At higher gas-volume fractions up to 98%, accuracy deteriorated but the meter continued to provide repeatable results.

  10. GC estimation of organic hydrocarbons that threaten shallow Quaternary sandy aquifer Northwestern Gulf of Suez, Egypt.

    PubMed

    Zawrah, M F; Ebiad, M A; Rashad, A M; El-Sayed, E; Snousy, Moustafa Gamal; Tantawy, M A

    2014-11-01

    Soil and groundwater contamination is one of the important environmental problems at petroleum-related sites, which causes critical environmental and health defects. Severe petroleum hydrocarbon contamination from coastal refinery plant was detected in a shallow Quaternary sandy aquifer is bordered by Gulf in the Northwestern Gulf of Suez, Egypt. The overall objective of this investigation is to estimate the organic hydrocarbons in shallow sandy aquifers, released from continuous major point-source of pollution over a long period of time (91 years ago). This oil refinery contamination resulted mainly in the improper disposal of hydrocarbons and produced water releases caused by equipment failures, vandalism, and accidents that caused direct groundwater pollution or discharge into the gulf. In order to determine the fate of hydrocarbons, detailed field investigations were made to provide intensive deep profile information. Eight composite randomly sediment samples from a test plot were selected for demonstration. The tested plot was 50 m long × 50 m wide × 70 cm deep. Sediment samples were collected using an American auger around the point 29° 57' 33″ N and 32° 30' 40″ E in 2012 and covered an area of 2,500 m(2) which represents nearly 1/15 of total plant area (the total area of the plant is approximately 3.250 km(2)). The detected total petroleum hydrocarbons (TPHs) were 2.44, 2.62, 4.54, 4.78, 2.83, 3.22, 2.56, and 3.13 wt%, respectively. TPH was calculated by differences in weight and subjected to gas chromatography (GC). Hydrocarbons were analyzed on Hewlett-Packard (HP-7890 plus) gas chromatograph equipped with a flame ionization detector (FID). The percentage of paraffine of the investigated TPH samples was 7.33, 7.24, 7.58, 8.25, 10.25, 9.89, 14.77, and 17.53 wt%, respectively. PMID:25052330

  11. Structural evolution and Cenozoic tectonostratigraphy of the Cairo-Suez district, north Eastern Desert of Egypt: Field-structural data from Gebel Qattamiya-Gebel Um Reheiat area

    NASA Astrophysics Data System (ADS)

    Hagag, Wael

    2016-06-01

    Detailed field mapping reveals that continental rifting is strongly deforming the Gebel Qattamiya-Gebel Um Reheiat area and the entire Cairo-Suez district, in north Eastern Desert of Egypt. Rift-related structures are predominantly represented by E to WNW, NNW and NW oriented faults. The E to WNW oriented faults are small and build up the Gebel Qattamiya en echelon fault belt, whereas the faults trending NNW and NW establish a pervasive horst and graben structural style involving some rhomb-shape horsts as Gebel Qattamiya (GQRH), Gebel Um Reheiat (GURRH) and south Gebel Um Reheiat (SGURRH). Rock units of the Eocene succession and Oligocene sediments are well exposed and highly controlled by rift-related structures. Rifting was developed through two rift-phases; initial and major ones. The initial phase (a newly recognized phase in this contribution) has been occurred in Late Eocene (Priabonian), while the main phase was prevailing during Late Oligocene-Early Miocene time and is characterized by hydrothermal veins and basaltic eruptions. Continental transtension in the Cairo-Suez district, including the study area, was probably synchronous with a major tectonic stage (Pyrenean-Atlasic movement) of continental collision between African-Arabian and Eurasian plates in Late Eocene-Oligocene time. Field investigation suggests that the transfer of displacement (slip) from the Gulf of Suez proto-rift into the E-W oriented faults ''relays'' is an important mechanism, which helps to explain the current structural framework and tectonic evolution of the Cairo-Suez district. Reactivation of such faults with right-lateral divergent wrenching with NE-SW oriented extension deformed the Cairo-Suez district with several E-W oriented en echelon fault belts (e.g. Gebel Qattamiya fault belt in the study area). Thus the Cairo-Suez district represents an accommodation or transfer zone in northeastern Egypt, intercepting the ''far-field stresses'' from the Arabian-Nubian Shield, the Red Sea-Gulf of Suez rift and the Maghrebian Shield.

  12. Kinematics of Plio-Pleistocene Oblique faults in the Gulf of Suez Rift, West Central Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Abdeen, Mamdouh; Abdelmaksoud, Ashraf

    2015-04-01

    Detailed field mapping and structural studies on a segment of the Gulf of Suez rift in the west central part of Sinai Peninsula indicate the presents of a set of WNW-ESE striking dextral faults cutting another set of NNE-SSE striking sinistral fault. Both fault sets cut and obliterate an older fault set striking NW-SE. The NW-SE striking fault set is known to be of Oligo-Miocene time. The WNW-ESE and the NNE-SSW striking fault affect Pliocene and Pleistocene sediments. Therefore these two fault sets are younger. These angle between these two fault sets are in the range of 60-80 degrees and are believed to be a conjugate fault set that they are temporally associated. These observations indicate that the rifting is still active. This observation is confirmed by earthquake activity at the same area.

  13. Entre Reproduction et Mobilisation: les Rapports de Genre EN Formation Continue EN France et AU Canada

    NASA Astrophysics Data System (ADS)

    Fourner, Christine; Béret, Pierre; Doray, Pierre; Bélanger, Paul

    2009-01-01

    REPRODUCTION OR MOBILISATION? GENDER PROPORTIONS IN CONTINUING EDUCATION IN FRANCE AND CANADA - Initial education provisions for women have evolved greatly over the past 40 years. But what about their situation within adult education and training? This article, comparing Canada and France, shows that, while it is well known that more women than men participate in adult education, their greater presence in professional training courses is a new development. The analysis highlights certain particular findings, such as the growing demand for continuing education in Canada and the increased rate of participation by full-time employees in France. In both countries, a number of social factors continue to influence women's participation.

  14. Carcinome basocellulaire de la face: à propos de quatre cas rapportés à Madagascar

    PubMed Central

    Razafindrakoto, Rex Mario; Razafindranaivo, Mananjara Nandrianina; Schammirah, Mahamad Rojovolaarivony; Randriamboavonjy, Rado

    2015-01-01

    Les carcinomes basocellulaires, fréquemment rencontrés dans la race blanche, sont plus rares chez les sujets de race noire. Les zones exposées de la tête sont des sites préférentiels, et une intense exposition aux rayons solaires ultraviolets a été évoquée dans leur étiopathogénie. Les métastases sont exceptionnelles. Les objectifs ont été de démontrer l'existence de carcinomes basocellulaires à Madagascar et d'en évaluer la prise en charge. Les auteurs ont rapporté quatre cas de carcinomes basocellulaires faciaux vus au service d'Oto-rhino-laryngologie du Centre Hospitalier Universitaire d'Antananarivo, avec deux hommes et deux femmes, âgés entre 46 et 70 ans (âge moyen= 53,5 ans). Une exérèse chirurgicale a été pratiquée chez trois patients tandis qu'un patient albinos a été traité par radiothérapie. L’épidémiologie, l’étiologie, l'anatomie pathologique et le traitement des carcinomes basocellulaires de la face ont été discutées à travers une revue de la littérature. PMID:26848344

  15. Marine integrons containing novel integrase genes, attachment sites, attI, and associated gene cassettes in polluted sediments from Suez and Tokyo Bays.

    PubMed

    Elsaied, Hosam; Stokes, Hatch W; Kitamura, Keiko; Kurusu, Yasurou; Kamagata, Yoichi; Maruyama, Akihiko

    2011-07-01

    In order to understand the structure and biological significance of integrons and associated gene cassettes in marine polluted sediments, metagenomic DNAs were extracted from sites at Suez and Tokyo Bays. PCR amplicons containing new integrase genes, intI, linked with novel gene cassettes, were recovered and had sizes from 1.8 to 2.5 kb. This approach uncovered, for the first time, the structure and diversity of both marine integron attachment site, attI, and the first gene cassette, the most efficiently expressed integron-associated gene cassette. The recovered 13 and 20 intI phylotypes, from Suez and Tokyo Bay samples, respectively, showed a highly divergence, suggesting a difference in integron composition between the sampling sites. Some intI phylotypes showed similarity with that from Geobacter metallireducens, belonging to Deltaproteobacteria, the dominant class in both sampling sites, as determined by 16S rRNA gene analysis. Thirty distinct families of putative attI site, as determined by the presence of an attI-like simple site, were recovered. A total of 146 and 68 gene cassettes represented Suez and Tokyo Bay unsaturated cassette pools, respectively. Gene cassettes, including a first cassette, from both sampling sites encoded two novel families of glyoxalase/bleomycin antibiotic-resistance protein. Gene cassettes from Suez Bay encoded proteins similar to haloacid dehalogenases, protein disulfide isomerases and death-on-curing and plasmid maintenance system killer proteins. First gene cassettes from Tokyo Bay encoded a xenobiotic-degrading protein, cardiolipin synthetase, esterase and WD40-like β propeller protein. Many of the first gene cassettes encoded proteins with no ascribable function but some of them were duplicated and possessed signal functional sites, suggesting efficient adaptive functions to their bacterial sources. Thus, each sampling site had a specific profile of integrons and cassette types consistent with the hypothesis that the environment shapes the genome. PMID:21248857

  16. Marine integrons containing novel integrase genes, attachment sites, attI, and associated gene cassettes in polluted sediments from Suez and Tokyo Bays

    PubMed Central

    Elsaied, Hosam; Stokes, Hatch W; Kitamura, Keiko; Kurusu, Yasurou; Kamagata, Yoichi; Maruyama, Akihiko

    2011-01-01

    In order to understand the structure and biological significance of integrons and associated gene cassettes in marine polluted sediments, metagenomic DNAs were extracted from sites at Suez and Tokyo Bays. PCR amplicons containing new integrase genes, intI, linked with novel gene cassettes, were recovered and had sizes from 1.8 to 2.5 kb. This approach uncovered, for the first time, the structure and diversity of both marine integron attachment site, attI, and the first gene cassette, the most efficiently expressed integron-associated gene cassette. The recovered 13 and 20 intI phylotypes, from Suez and Tokyo Bay samples, respectively, showed a highly divergence, suggesting a difference in integron composition between the sampling sites. Some intI phylotypes showed similarity with that from Geobacter metallireducens, belonging to Deltaproteobacteria, the dominant class in both sampling sites, as determined by 16S rRNA gene analysis. Thirty distinct families of putative attI site, as determined by the presence of an attI-like simple site, were recovered. A total of 146 and 68 gene cassettes represented Suez and Tokyo Bay unsaturated cassette pools, respectively. Gene cassettes, including a first cassette, from both sampling sites encoded two novel families of glyoxalase/bleomycin antibiotic-resistance protein. Gene cassettes from Suez Bay encoded proteins similar to haloacid dehalogenases, protein disulfide isomerases and death-on-curing and plasmid maintenance system killer proteins. First gene cassettes from Tokyo Bay encoded a xenobiotic-degrading protein, cardiolipin synthetase, esterase and WD40-like β propeller protein. Many of the first gene cassettes encoded proteins with no ascribable function but some of them were duplicated and possessed signal functional sites, suggesting efficient adaptive functions to their bacterial sources. Thus, each sampling site had a specific profile of integrons and cassette types consistent with the hypothesis that the environment shapes the genome. PMID:21248857

  17. Controls on the development and evolution of transfer zones: the influence of basement structure and sedimentary thickness in the Suez rift and Red Sea

    NASA Astrophysics Data System (ADS)

    Moustafa, Adel R.

    1997-06-01

    Detailed field mapping of the northern part of the Gebel Um Hammad-Gebel Duwi area on the western margin of the Red Sea indicates oppositely dipping rift blocks separated by a 60-km long, WNW-ESE-oriented, reactivated pre-rift fault of Late Precambrian age parallel to the Najd fault system of the Arabian-Nubian Shield. This fault forms the Sudmain transfer zone between the oppositely tilted half-grabens in the northwestern Red Sea region and is associated by a SE-plunging syncline. This pre-rift fault was reactivated by dextral transtension during the Late Oligocene rift opening. Compared to the transfer zones of the Suez rift, the Sudmain transfer zone is narrower. The Gebel Sufr El Dara transfer zone (between the southern and central half-grabens of the Suez rift) is 20 km wide and is also controlled by pre-rift faults oriented ENE-WSW. The latter were reactivated by left-lateral slip during the rift opening. On the other hand, the Gharandal transfer zone (northern part of the Suez rift) is 40-60 km wide and is not affected by the pre-rift faults in the Precambrian basement, perhaps owing to the large thickness of pre-rift sedimentary rocks in this area. The location of the Gharandal transfer zone was controlled by a NE-SW-oriented 'Syrian arc' fold. This study suggests that the northward increase in the width of transfer zones as well as the northward decrease in the length of half-grabens in the Suez-northern Red Sea rift system are related to the corresponding increase in the thickness of pre-rift Phanerozoic sedimentary section from about 400 m in the south to about 1800 m in the north.

  18. Student Views of Instructor-Student Rapport in the College Classroom

    ERIC Educational Resources Information Center

    Webb, Nathan G.; Barrett, Laura Obrycki

    2014-01-01

    Building upon past research on the positive learning outcomes associated with rapport building in the classroom, this study examines the specific behaviors instructors utilize in college classrooms to build rapport with undergraduate students. Participants (N = 230) answered open-ended survey questions about their instructors'…

  19. Students' Attitudes towards Rapport-Building Traits and Practices in Online Learning Environments

    ERIC Educational Resources Information Center

    Wright, Robert Demmon

    2012-01-01

    This research was a triangulated study of student attitudes towards instructors' rapport-building traits and their preferences amongst instructors' rapport-building practices in online learning environments. Participants were undergraduate and graduate students enrolled in courses within an educational technology program at a central Texas…

  20. Quality of Rapport as a Setting Event for Problem Behavior: Assessment and Intervention

    ERIC Educational Resources Information Center

    McLaughlin, Darlene Magito; Carr, Edward G.

    2005-01-01

    Relationship quality (rapport) between people with developmental disabilities and their caregivers has long been suggested as an important variable influencing the likelihood of problem behavior. However, to date, the association between rapport and problem behavior has not been systematically investigated. The authors evaluated a multimethod…

  1. Nonverbal Rapport-Building Behaviors' Effects on Perceptions of a Supervisor.

    ERIC Educational Resources Information Center

    Heintzman, Mark; And Others

    1993-01-01

    Finds male supervisors can be effective in building rapport with subordinates solely by using certain nonverbal communicative behaviors. Shows that supervisors with such behaviors were more positively perceived than those without and that subordinates were more likely to comply with the requests of the high-rapport supervisor and to experience a…

  2. Verbal and Nonverbal Strategies of Rapport in Cross-Cultural Interviews.

    ERIC Educational Resources Information Center

    Fiksdal, Susan

    1988-01-01

    The verbal and nonverbal strategies of rapport, their environments, and their consequences are identified. Interviews between two foreign student advisors and 16 foreign students (both native and non-native speakers of English) were videotaped, and playback sessions with students and advisors were audio-recorded. Rapport-building and…

  3. Instructor-Student and Student-Student Rapport in the Classroom

    ERIC Educational Resources Information Center

    Frisby, Brandi N.; Martin, Matthew M.

    2010-01-01

    This study examined the relationships between instructors and their students, and between students, to determine their roles in building positive relationships and an overall positive classroom environment. Of particular interest was the examination of instructor rapport with students and rapport between students. Students (N = 232) reported on…

  4. Kinematics of the oblique faults in the east central Gulf of Suez Rift, Wadi Araba, Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Abdeen, Mamdouh; Abdelmaksoud, Ashraf

    2014-05-01

    The Oligo-Miocene Gulf of Suez rift is characterized by four fault trends; a rift-parallel trend, two trends oblique to the rift trend and a cross trend. The rift-parallel trend strikes 310o to 340o and is referred to as the Clysmic trend. The two trends, which are oblique to the Clysmic trend, strike 350o to 030o and 280o to 310o; the first has been referred to as the north-oblique (N-oblique), and the second as the northwest-oblique (NW-oblique). The cross trend includes faults nearly orthogonal to the Clysmic trend i.e. they strike between 050o and 075o. Image interpretation and detailed field mapping and structural studies at a scale of 1: 20,000 of the Wadi Araba area in southwest Sinai Peninsula indicate e Clysmic faults are mostly normal showing major dip-slip movements. The oblique faults were found to be younger than the Clysmic faults and that the N-oblique faults are characterized by major sinistral strike-slip movement, while the NW-oblique faults are characterized by major dextral strike-slip movement. Cross cutting relationship, geometry and palaeostress analysis indicate that the oblique faults are conjugate Riedel shears originated due to NE to NNE extension related to the Aqaba-Levant transform that has been active since the Middle Miocene.

  5. Q-values for P and S waves in Southern Sinai and Southern Gulf of Suez Region, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Gad-Elkareem A.

    2014-05-01

    The quality factor Q has been estimated using spectral amplitudes of P and S waves from earthquakes recorded by the seismic network of the Egyptian National Seismological Network (ENSN) in southern Sinai and southern Gulf of Suez region. The earthquakes recorded at nine stations - DHA, NUB, TR1, TR2, KAT, SH2, GRB, HRG and SFG have been used in this study. The spectral amplitude ratios have been calculated between 2 - 20 Hz and single station spectral ratio method has been applied for this purpose. The results show that the quality factors for both P and S waves (Qp and Qs) increase as a function of frequency according to law the Q = Q0fn. By averaging the estimated Q- Value obtained at all stations we calculated the average attenuation laws: Qp = (13.15± 0.76) f0.95± 0.19 and Qs = (20.05± 0.79) f1.03±0.04 for P and S waves respectively. These relations are useful for the estimation of source parameters of earthquakes and simulation of earthquake strong ground motions. The QS /QP ratio for KAT station is less than 1 at lower frequencies, whereas at HRG and SH2 stations QS /QP ratio is are greater than 1.

  6. Organic tracers in sediments from the coastal zone of Ras Abu el-Darag, Gulf of Suez

    NASA Astrophysics Data System (ADS)

    Rushdi, Ahmed I.; Kassim, Tarek A. T. A.; Simoneit, Bernd R. T.

    2009-10-01

    Sediment samples from the coastal zone of the Gulf of Suez contain a variety of organic compounds from anthropogenic and natural sources. A total of 12 surface samples of bottom sediments were collected with an Ekman grab sampler along an off-shore transect south of Ras Abu el-Darag. The samples were extracted with a mixture of dichloromethane and methanol (3:1 v/v) after drying and sieving through 250 μm mesh. The extracts were derivatized and analyzed by gas chromatography-mass spectrometry in order to characterize the chemical composition and sources of the organic components. Marine with minor terrestrial biota were the major natural sources of organic tracers and included n-alkanoic acids, sterols and saccharides (5.7-76.7%). Anthropogenic sources, from petroleum related activities, detergent usage for spill cleaning and littering, are indicated by the presence of n-alkanes with carbon preference index ≤1.0, hopanes, steranes, unresolved complex mixture of branched and cyclic hydrocarbons, alkyl nitriles, alkamides and plasticizers. Their total relative concentrations ranged from 23.3 to 97.3% of the total extracts. Petroleum residues from natural seepage may also be part of these hydrocarbons. The levels of anthropogenic inputs decrease from about 94% in coastal zone sediments to about 20% in sediments from the reef front.

  7. Maastrichtian-Early Eocene litho-biostratigraphy and palægeography of the northern Gulf of Suez region, Egypt

    NASA Astrophysics Data System (ADS)

    Scheibner, C.; Marzouk, A. M.; Kuss, J.

    2001-02-01

    The Maastrichtian-Lower Eocene sediments on both sides of the northern Gulf of Suez can be subdivided into eight formal formations (including one group) and one informal formation that are described in detail. These lithostratigraphic units reflect three different environmental regimes of deposition or non-deposition. The first regime is characterised by uplift and erosion or non-deposition resulting mostly from the uplift of the Northern Galala/Wadi Araba structure, a branch of the Syrian Arc Foldbelt. The shallow water carbonate platform and slope deposits of the Late Campanian-Maastrichtian St Anthony Formation and the Paleocene-Lower Eocene Southern Galala and Garra Formations represent the second regime and are found north and south of the Northern Galala/Wadi Araba High. The third regime is represented by basinal chalks, marls and shales of the Maastrichtian Sudr Formation and of the Paleocene-Eocene Dakhla, Tarawan and Esna Formations, the Dakhla/Tarawan/Esna informal formation and the Thebes Group. The distribution and lateral interfingering of the above mentioned environmental regimes reflect different vertical movements, changing basin morphology, sea level changes and progradation of shallow water sediments and is illustrated on 11 palæogeographic maps.

  8. Strangers in sync: Achieving embodied rapport through shared movements

    PubMed Central

    Vacharkulksemsuk, Tanya; Fredrickson, Barbara L.

    2011-01-01

    This paper examines the emergence of behavioral synchrony among strangers in the context of self-disclosure, and their path in predicting interaction quality. Specifically, we hypothesize that behavioral synchrony mediates the direct effect of self-disclosure on the development of embodied rapport. Same-sex stranger pairs (n=94) were randomly assigned to a videorecorded self-disclosure or control condition, and afterward each member rated their social interaction. Following the procedure used by Bernieri, Reznick, & Rosenthal (1988), two trained judges independently watched each video record and rated each pair interaction on behavioral synchrony. Bootstrapping analyses provide support for the hypothesized mediating effect of behavioral synchrony, which emerged as independent of the effects of self-other overlap and positive affect. The authors discuss implications of behavioral synchrony for relationship formation processes and the inevitable entwinement of behavior and judgments in light of embodied cognition. PMID:22389521

  9. The Extravert Advantage: How and When Extraverts Build Rapport With Other People.

    PubMed

    Duffy, Korrina A; Chartrand, Tanya L

    2015-11-01

    Extraverts are better than introverts at building rapport, but it remains unknown what they do behaviorally to better connect with other individuals. We hypothesized that extraverts mimic more than introverts as a way to build rapport; however, we predicted that this social skillfulness of extraverts emerges only when they are motivated to affiliate. In Study 1, we found that extraversion predicted increased mimicry when an affiliation goal was present, but not when an affiliation goal was absent. In Study 2, we found that mimicry mediates the relationship between extraversion and rapport, but only when an affiliation goal is present. Our findings are the first to identify a behavior that extraverts engage in that helps them build rapport. Furthermore, our studies show that this skillfulness of extraverts emerges only when they are motivated to affiliate, providing evidence in favor of the reward-sensitivity-as-core model of extraversion over the sociability-as-core model of extraversion. PMID:26408038

  10. Facies and depositional environment of the Holocene evaporites in the Ras Shukeir area, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Aref, M. A. M.; Attia, O. E. A.; Wali, A. M. A.

    1997-05-01

    The Holocene evaporite sequence in the Ras Shukeir area conformably overlies marine shell banks and cross-bedded to graded-bedded beach sands and gravels. The evaporite sequence is represented by gypsum-anhydrite layers that are interbedded with mudstone layers. Field and petrographic investigations of the evaporite deposits revealed two facies types, laminated evaporite facies (primary) and nodular to enterolithic anhydrite facies (diagenetic). The laminated evaporite facies is subdivided, from the bottom to top, into regular laminated evaporite, chevron gypsum-algal micrite laminations and wavy algal laminated evaporite. Based on their textures and fabrics, the regular and wavy laminated evaporite facies are interpreted as primary deposits in a coastal lagoon and salina environment. The chevron gypsum-algal micrite facies formed by the growth of chevron gypsum at the sediment-water interface within a shallow subtidal lagoonal environment that was characterized by extensive benthic algal mats. The nodular to enterolithic anhydrite facies is secondary and formed diagenetically within a siliciclastic supratidal sediment. Some of the laminated evaporite facies have been diagenetically altered in a supratidal sabkha environment as evidenced by the following: (1) the partial formation of nodular evaporite instead of laminated evaporite; (2) disruption of gypsum laminations by plant roots and rootlets as well as by precipitation of lenticular gypsum on the root wall; and (3) partial dissolution of halite laminae and the formation of wavy anhydrite laminae. Consequently, the Holocene evaporites in the Ras Shukeir area were deposited in a shallow semi-closed to closed basin that was separated from the Gulf of Suez trough. Changing sea level led to progradation of the evaporite facies from subtidal to intertidal lagoon and salina to a supratidal sabkha.

  11. Oil pollution in the Red Sea — Environmental monitoring of an oilfield in a coral area, Gulf of Suez

    NASA Astrophysics Data System (ADS)

    Dicks, Brian

    The Red Sea is rapidly developing as one of the world's largest offshore oil production areas. It also comprises a wide range of tropical marine habitats, many of which are internationally recognised for their conservation, scientific, economic or recreational value. Past oil production, refining and transport have resulted in chronic pollution of some areas, and environmental programmes to protect new areas of development from pollution damage are assuming increasing importance. At the initiative of an Egyptian oil company operating in the Gulf of Suez, an environmental protection and management scheme has been prepared for a new offshore oilfield and marine terminal at Ras Budran. This paper describes the form of the scheme and the results of its component environmental surveys. The development area comprises rich and diverse marine communities of fringing coral reefs, nearshore lagoons, seagrass beds, sandy beaches and fine sediments offshore. A baseline survey was designed following detailed discussion of the scope of the development with the company and a preliminary site visit, and the fieldwork was completed in October 1980. On the basis of the findings of the survey, a series of recommendations was made to the company, aimed at reducing environmental impacts during construction and operation to a minimum and acceptable level. These were subsequently implemented and the results of a post-construction survey in February 1983 are reported which show that environmental damage to the nearshore habitats during the construction phase had been relatively small and localised. Recently, the biological information obtained from the two surveys has also been incorporated into oil spill contingency plans.

  12. Provenance, diagenesis, tectonic setting and geochemistry of Rudies sandstone (Lower Miocene), Warda Field, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Zaid, Samir M.

    2012-05-01

    The Lower Miocene Rudies sandstones are important oil reservoirs in the southeastern part, Gulf of Suez basin, Egypt. However, their provenance and diagenesis and their impact in reservoir quality, are virtually unknown. Samples from the Warda field, representing the Lower and Middle Rudies, were studied using a combination of petrographic, mineralogical and geochemical techniques. The Lower Rudies sandstones have an average framework composition of Q85F7.2R7.8, and 83% of the quartz grains are monocrystalline. By contrast, the Middle Rudies sandstones are only slightly more quartzose with an average framework composition of Q90F7R3 and 86% of the quartz grains are monocrystalline. Rudies sandstones are mostly quartz arenite with subordinate subarkose and sublithic arenites and their bulk-rock geochemistry support the petrographic results. The modal analysis data of studied samples suggest influence of granitic and metamorphic terrains as the main source rock with a subordinate quartzose recycled sedimentary rocks. The geochemical data interpretation on the basis of discriminate function diagrams reveal the source material was deposited on a passive margin. Textural attributes possibly suggest long-distance transport of grains from the source region and indicates a cratonic or a recycled source. Tectonic setting of Rudies Formation reveals that the lower Rudies sandstones are typically rift sandstone and their deposition constrained the beginning of the faulting, while the middle Rudies sandstones were transported from the far along the rift. Diagenetic features include compaction; dolomite, silica and anhydrite cementation with minor iron-oxide, illite, kaolinite and pyrite cements; dissolution of feldspars, rock fragments. Silica dissolution, grain replacement and carbonate dissolution greatly enhance the petrophysical properties of many sandstone samples.

  13. Provenance, diagenesis, tectonic setting and reservoir quality of the sandstones of the Kareem Formation, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    Zaid, Samir M.

    2013-09-01

    The Middle Miocene Kareem sandstones are important oil reservoirs in the southwestern part of the Gulf of Suez basin, Egypt. However, their diagenesis and provenance and their impact on reservoir quality, are virtually unknown. Samples from the Zeit Bay Oil Field, and the East Zeit Oil Field represent the Lower Kareem (Rahmi Member) and the Upper Kareem (Shagar Member), were studied using a combination of petrographic, mineralogical and geochemical techniques. The Lower Rahmi sandstones have an average framework composition of Q95F3.4R1.6, and 90% of the quartz grains are monocrystalline. By contrast, the Upper Shagar sandstones are only slightly less quartzose with an average framework composition of Q76F21R3 and 82% of the quartz grains are monocrystalline. The Kareem sandstones are mostly quartzarenite with subordinate subarkose and arkose. Petrographical and geochemical data of sandstones indicate that they were derived from granitic and metamorphic terrains as the main source rock with a subordinate quartzose recycled sedimentary rocks and deposited in a passive continental margin of a syn rift basin. The sandstones of the Kareem Formation show upward decrease in maturity. Petrographic study revealed that dolomite is the dominant cement and generally occurs as fine to medium rhombs pore occluding phase and locally as a grain replacive phase. Authigenic quartz occurs as small euhedral crystals, locally as large pyramidal crystals in the primary pores. Authigenic anhydrites typically occur as poikilotopic rhombs or elongate laths infilling pores but also as vein filling cement. The kaolinite is a by-product of feldspar leaching in the presence of acidic fluid produced during the maturation of organic matter in the adjacent Miocene rocks. Diagenetic features include compaction; dolomite, silica and anhydrite cementation with minor iron-oxide, illite, kaolinite and pyrite cements; dissolution of feldspars, rock fragments. Silica dissolution, grain replacement and carbonate dissolution greatly enhance the petrophysical properties of many sandstone samples.

  14. When Rapport Building Extends Beyond Affiliation: Communication Overaccommodation Toward Patients with Disabilities

    PubMed Central

    Duggan, Ashley P; Bradshaw, Ylisabyth S; Swergold, Natalie; Altman, Wayne

    2011-01-01

    Introduction: Physician rapport with patients is described as a vital component of relationship-centered care, but rapport-building communication behaviors may exceed boundaries and instead indicate patronizing behavior toward patients with disabilities. This paper addresses the types of communication behaviors and contexts for interpreting when rapport building extends beyond boundaries toward patients with disabilities. Methods: Videotaped interactions between third- and fourth-year medical students (N = 142) and standardized patient educators with physical disabilities were qualitatively analyzed. Results: Results suggest six primary themes of exceeding expected rapport boundaries, including baby talk (ie, exaggerated nonverbal gestures and we language to indicate you), kinesic movement (ie, stiff posture and awkward handshakes), vocalics (ie, volume or pitch that interfered with the flow of conversation), relationship assumptions (ie, communicating assumptions that relationships were grounded in care-receiving), emotional divergence from patient disclosure (ie, minimizing or embellishing disability), and inconsistency with patient emotional cues (ie, responding to negative or neutral disclosure by overly accentuating positive interpretation). Discussion: This study suggests that communication behaviors generally described as positive, rapport-building behaviors can pose negative implications when they exceed the expected quantity or duration, when they are inconsistent with patient verbal disclosure, or when verbal and nonverbal messages are inconsistent. Identified themes serve as examples to understand when rapport building exceeds beyond affiliation and instead appears to indicate patronizing behavior toward patients with disabilities. Suggestions for interpreting communication behaviors within the context of patient disclosure and building capacity to distinguish attitudes and biases limiting communication are addressed. PMID:21841921

  15. Training in Compensatory Strategies Enhances Rapport in Interactions Involving People with Möbius Syndrome

    PubMed Central

    Michael, John; Bogart, Kathleen; Tylén, Kristian; Krueger, Joel; Bech, Morten; Østergaard, John Rosendahl; Fusaroli, Riccardo

    2015-01-01

    In the exploratory study reported here, we tested the efficacy of an intervention designed to train teenagers with Möbius syndrome (MS) to increase the use of alternative communication strategies (e.g., gestures) to compensate for their lack of facial expressivity. Specifically, we expected the intervention to increase the level of rapport experienced in social interactions by our participants. In addition, we aimed to identify the mechanisms responsible for any such increase in rapport. In the study, five teenagers with MS interacted with three naïve participants without MS before the intervention, and with three different naïve participants without MS after the intervention. Rapport was assessed by self-report and by behavioral coders who rated videos of the interactions. Individual non-verbal behavior was assessed via behavioral coders, whereas verbal behavior was automatically extracted from the sound files. Alignment was assessed using cross recurrence quantification analysis and mixed-effects models. The results showed that observer-coded rapport was greater after the intervention, whereas self-reported rapport did not change significantly. Observer-coded gesture and expressivity increased in participants with and without MS, whereas overall linguistic alignment decreased. Fidgeting and repetitiveness of verbal behavior also decreased in both groups. In sum, the intervention may impact non-verbal and verbal behavior in participants with and without MS, increasing rapport as well as overall gesturing, while decreasing alignment. PMID:26500605

  16. Developing Rapport with Children in Forensic Interviews: Systematic Review of Experimental Research.

    PubMed

    Saywitz, Karen J; Larson, Rakel P; Hobbs, Sue D; Wells, Christine R

    2015-08-01

    The vast majority of guidelines recommend that developing rapport with children is essential for successful forensic child interviewing; however, the question remains as to whether there is a sufficient body of scientific research to generate evidence-based guidelines for developing rapport with children in legal contexts. To answer this question, we conducted a systematic review of the literature to identify experimental studies of the effects of rapport-building methods on the reliability of children's reports. Independent raters applied 12 exclusion criteria to the 2,761 potentially relevant articles located by electronic and hand searches of the literature. Experimental studies were few. Although studies to date are a beginning, the overall scientific base is weak regarding even basic issues such as how to best define rapport and the efficacy of common rapport-building techniques. This systematic review highlights what we know, what we do not know, and how much more we need to know to create evidence-based best practice. Recommendations for reshaping the research agenda are discussed. PMID:26206588

  17. Do Prosecutors Use Interview Instructions or Build Rapport with Child Witnesses?

    PubMed Central

    Ahern, Elizabeth C.; Stolzenberg, Stacia N.; Lyon, Thomas D.

    2015-01-01

    This study examined the quality of interview instructions and rapport-building provided by prosecutors to 168 children aged 5–12 years testifying in child sexual abuse cases, preceding explicit questions about abuse allegations. Prosecutors failed to effectively administer key interview instructions, build rapport, or rely on open-ended narrative producing prompts during this early stage of questioning. Moreover, prosecutors often directed children's attention to the defendant early in the testimony. The productivity of different types of wh- questions varied, with what/how questions focusing on actions being particularly productive. The lack of instructions, poor quality rapport-building, and closed-ended questioning suggest that children may not be adequately prepared during trial to provide lengthy and reliable reports to their full ability. PMID:26206485

  18. Eliciting maltreated and nonmaltreated children's transgression disclosures: narrative practice rapport building and a putative confession.

    PubMed

    Lyon, Thomas D; Wandrey, Lindsay; Ahern, Elizabeth; Licht, Robyn; Sim, Megan P Y; Quas, Jodi A

    2014-01-01

    This study tested the effects of narrative practice rapport building (asking open-ended questions about a neutral event) and a putative confession (telling the child an adult "told me everything that happened and he wants you to tell the truth") on 4- to 9-year-old maltreated and nonmaltreated children's reports of an interaction with a stranger who asked them to keep toy breakage a secret (n = 264). Only one third of children who received no interview manipulations disclosed breakage; in response to a putative confession, one half disclosed. Narrative practice rapport building did not affect the likelihood of disclosure. Maltreated children and nonmaltreated children responded similarly to the manipulations. Neither narrative practice rapport building nor a putative confession increased false reports. PMID:24467688

  19. Do Prosecutors Use Interview Instructions or Build Rapport with Child Witnesses?

    PubMed

    Ahern, Elizabeth C; Stolzenberg, Stacia N; Lyon, Thomas D

    2015-08-01

    This study examined the quality of interview instructions and rapport-building provided by prosecutors to 168 children aged 5-12 years testifying in child sexual abuse cases, preceding explicit questions about abuse allegations. Prosecutors failed to effectively administer key interview instructions, build rapport, or rely on open-ended narrative producing prompts during this early stage of questioning. Moreover, prosecutors often directed children's attention to the defendant early in the testimony. The productivity of different types of wh- questions varied, with what/how questions focusing on actions being particularly productive. The lack of instructions, poor quality rapport-building, and closed-ended questioning suggest that children may not be adequately prepared during trial to provide lengthy and reliable reports to their full ability. PMID:26206485

  20. Unbridged Au(II)-Au(II) bonds are theoretically allowed.

    PubMed

    Xiong, Xiao-Gen; Pyykkö, Pekka

    2013-03-14

    The bonding in the unbridged closed-shell Au(II)-Au(II) dimers X(4)Au(2)(C(5)H(5)N)(2), X = H, F-I and CF(3), is analyzed and the short Au-Au bonds around 250 pm are reproduced by a novel 6s6p(z)5d(xy) hybridization. PMID:23321690

  1. Tectonic and stratigraphic evolution of the Neogene Gulf of Suez and northern Red Sea rift: Depositional environment and hydrocarbon source potential of evaporites

    SciTech Connect

    Richardson, M.

    1988-01-01

    Quantitative basin analysis (backstripping) was carried out to examine the interplay between basin subsidence, tectonic events, sedimentation patterns and sea level changes in a young developing ocean basin and continental margin. Rifting and subsidence were initiated {approximately}25 Ma with the earliest sediments within the basin recording the transition from continental to marine depositional environments. Open marine sedimentation continued in the basin from early to middle Miocene times with a series of prograding siliciclastic fan-deltas developing at the rift-margins in response to major tectonic events and periods of lowered global sea level. Opening and major subsidence with the rift-basin was termination at {approximately}15.5 Ma as tensional plate motions were transferred from the Gulf of Suez to sinistral strike-slip movement on the Dead Sea transform fault system. Tectonic quiescence combined with lowered global sea level resulted in the deposition of up to 3 km of evaporites in the rift basin from middle to late Miocene times. The evaporite strata contain significant amounts of well-preserved organic carbon (OC). Rock-Eval and elemental pyrolysis analysis indicates that the kerogen in these OC-rich evaporite associated sediments constitutes good to excellent potential hydrocarbon source-rock. Gas chromatography studies show that free hydrocarbons derived from these sediments are indigenous and derived from organic carbon deposited and preserved in a highly reducing, anoxic, hypersaline environment. Thermal modeling and Rock-Eval pyrolysis analysis results indicate that although evaporite-associated OC is immature in the Gulf of Suez and northern Red Sea, OC-rich evaporite strata are buried within the oil window in the southern Red Sea.

  2. Accouchement de jumeaux conjoints de découverte fortuite au cours du travail au CHU de Dakar

    PubMed Central

    Guèye, Mamour; Guèye, Serigne Modou Kane; Guèye, Mame Diarra Ndiaye; Diouf, Abdoul Aziz; Niang, Mouhamadou Mansour; Diallo, Moussa; Cissé, Mamadou Lamine; Moreau, Jean Charles

    2012-01-01

    L'objectif de cette étude était de rapporter 3 cas de jumeaux conjoints, discuter de l'importance du diagnostic anténatal et de décrire les particularités diagnostiques, thérapeutiques et évolutives. Sur 45700 accouchements du 1er Février 2009 au 31 Décembre 2011, 3 cas de jumeaux conjoints ont été enregistrés, soit 1 cas pour 15000 accouchements. Ces cas ont été diagnostiqués au cours du travail au décours d'une dystocie mécanique ou d'une césarienne réalisée pour une autre indication. Il s'agissait d'un cas de jumeaux conjoints thoraco-omphalopages, un cas de diprosopes et un cas de dicéphales. L'accouchement dans les trois cas était fait par voie haute permettant d'extraire des mort-nés frais. Nous insistons sur l'intérêt d'un diagnostic anténatal précoce par le recours à l’échographie afin d’éviter les accidents mécaniques d'un accouchement qui ne saurait s'accomplir par voie basse. PMID:23133702

  3. More than Just Language Advising: Rapport in University English Writing Consultations and Implications for Tutor Training

    ERIC Educational Resources Information Center

    Lee, Cynthia

    2015-01-01

    Adopting a case study approach with multiple data sources, this paper explores the ways in which rapport is built, and its impact on the learning process based on five successive writing support consultations between a native English-speaking (NES) tutor and her second language (L2) tutee in a Hong Kong university. With reference to the prepared…

  4. Physicians' Nonverbal Rapport Building and Patients' Talk About the Subjective Component of Illness.

    ERIC Educational Resources Information Center

    Duggan, Ashley P.; Parrott, Roxanne L.

    2001-01-01

    Considers how physicians' nonverbal communication is sometimes associated with patients' affective satisfaction. Examines the relationship between physicians' nonverbal rapport building and patients' disclosure of information related to the subjective component of illness. Considers implications for understanding the role of physicians' nonverbal…

  5. Interaction of counseling rapport and topics discussed in sessions with methadone treatment clients.

    PubMed

    Joe, George W; Simpson, D Dwayne; Rowan-Szal, Grace A

    2009-01-01

    Therapeutic rapport between counselors and clients in drug user treatment has been shown to be an important predictor of follow-up outcomes. This naturalistic study investigated the relationship of counseling rapport to drug-related topics discussed in counseling sessions in a sample of 330 clients and nine counselors. These voluntary clients had been admitted to a private, for-profit outpatient methadone treatment in Texas between September 1995 and August 1997 and received no-fee services for a year for participation in this study. The data were gathered using forms in the TCU community treatment assessments (www.ibr.tcu.edu) that measured intake information, counseling session topics, and counselor evaluation of the client. A majority were males, Hispanic, had a pending legal status and the average age was 39. Co-occurring drug dependence for these heroin users included cocaine (38%) and alcohol (31%). The results supported the hypothesis that higher rapport would be associated with addressing clients in a more "supportive approach" that emphasized relapse prevention and strengths-building while lower rapport would be associated with a punitive counseling style that stressed program rules and compliance. The influences of client background, counselor differences, and during-treatment positive urines were also examined. Although counselors differed in their general manner of dealing with clients, each also showed flexibility determined in part by client behavior (such as continued cocaine use). The findings indicate that focusing on constructive solutions is the preferred counseling approach. PMID:19137479

  6. Managing Rapport in Lingua Franca Sales Negotiations: A Comparison of Professional and Aspiring Negotiators

    ERIC Educational Resources Information Center

    Planken, B.

    2005-01-01

    This article presents selective findings from a study that investigated how facework is used to achieve interpersonal goals in intercultural sales negotiations. The article reports on linguistic analyses of what Spencer-Oatey has termed ''rapport management'' which, in a negotiation context, is aimed primarily, but not exclusively, at building a…

  7. Reconsidering Rapport with Urban Teachers: Negotiating Shifting Boundaries and Legitimizing Support

    ERIC Educational Resources Information Center

    Rinke, Carol R.; Mawhinney, Lynnette

    2014-01-01

    This paper addresses Lincoln's [2010. "'What a long, strange trip it's been …': Twenty-five years of qualitative and new paradigm research." "Qualitative Inquiry" 16, no. 1: 3-9] call for greater attention to the question of rapport in qualitative research through a reflexive examination of…

  8. Professor-Student Rapport Scale: Psychometric Properties of the Brief Version

    ERIC Educational Resources Information Center

    Ryan, Rebecca

    2014-01-01

    The original Professor-Student Rapport Scale contained 34 items and predicted several single-item student outcomes. A high level of internal consistency encouraged the development of a shorter measure in order to address apparent redundancy. Our goals in the current study were to provide psychometric data for the brief version of the scale and to

  9. Saving Face: Managing Rapport in a Problem-Based Learning Group

    ERIC Educational Resources Information Center

    Robinson, Leslie; Harris, Ann; Burton, Rob

    2015-01-01

    This qualitative study investigated the complex social aspects of communication required for students to participate effectively in Problem-Based Learning and explored how these dynamics are managed. The longitudinal study of a group of first-year undergraduates examined interactions using Rapport Management as a framework to analyse communication…

  10. Humor, Rapport, and Uncomfortable Moments in Interactions with Adults with Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Kovarsky, Dana; Schiemer, Christine; Murray, Allison

    2011-01-01

    We examined uncomfortable moments that damaged rapport during group interactions between college students in training to become speech-language pathologists and adults with traumatic brain injury. The students worked as staff in a community-based program affiliated with a university training program that functioned as a recreational gathering…

  11. Reconsidering Rapport with Urban Teachers: Negotiating Shifting Boundaries and Legitimizing Support

    ERIC Educational Resources Information Center

    Rinke, Carol R.; Mawhinney, Lynnette

    2014-01-01

    This paper addresses Lincoln's [2010. "'What a long, strange trip it's been ': Twenty-five years of qualitative and new paradigm research." "Qualitative Inquiry" 16, no. 1: 3-9] call for greater attention to the question of rapport in qualitative research through a reflexive examination of

  12. The Effects of Assessment Feedback on Rapport- Building and Self-Enhancement Processes.

    ERIC Educational Resources Information Center

    Allen, Andrea; Montgomery, Marilyn; Tubman, Jonathan; Frazier, Leslie; Escovar, Luis

    2003-01-01

    An experiment was conducted to test the effects of assessment feedback on rapport and self-enhancement. Results suggest that both processes are mechanisms by which the provision of assessment feedback produces positive change. Implications for mental health counselors are drawn. (Contains 33 references and 2 tables.) (GCP)

  13. Preservice Music Teachers' and Therapists' Nonverbal Behaviors and Their Relationship to Perceived Rapport

    ERIC Educational Resources Information Center

    Darrow, Alice-Ann; Johnson, Christopher

    2009-01-01

    The purpose of the two studies reported in the article was to determine whether or not a relationship exists between preservice music therapists' and teachers' nonverbal behaviors and their perceived rapport. In study 1, evaluators (N = 56) viewed a stimulus tape consisting of 15 45-second segments of 15 preservice music therapists leading songs…

  14. Low-Temperature Au-Au Bonding Using Nanoporous Au-Ag Sheets

    NASA Astrophysics Data System (ADS)

    Mimatsu, Hayata; Mizuno, Jun; Kasahara, Takashi; Saito, Mikiko; Nishikawa, Hiroshi; Shoji, Shuichi

    2013-05-01

    In this study, we proposed low-temperature Au-Au bonding using nanoporous Au-Ag sheets, fabricated by dealloying a Au-Ag sheet in HNO3 solution, as a joint layer. The influence of the annealing temperature on the pore structure and chemical properties of the sheets was investigated. The chemical composition of the sheet was analyzed by X-ray photoelectron spectroscopy (XPS). It was found that the strength of Au-Au bonding with the nanoporous sheet increased. A sheet treated with liquid N2 was also tested; the strength of the Au-Au bond increased as a result of this low-temperature treatment.

  15. L'engelure causée par le butane commercial au cours d’un accident industriel

    PubMed Central

    Assi-Dje Bi Dje, V.; Abhe, C.M.; Sie-Essoh, J.B.; Kouamé, K.; Vilasco, B.

    2014-01-01

    Summary Les engelures sont encore exceptionnelles en Afrique sub-saharienne, mais l’essor des industries pétrochimiques en rapport avec la promotion d’une large utilisation du gaz domestique (butane commercial) expose au risque de survenue de ce type de brûlures abusivement dites gelures. Nous rapportons un cas de brûlures au froid par gaz de pétrole liquéfié (GPL) en milieu professionnel dont le diagnostic de gravité et la prise en charge tardifs ont défavorisé l’évolution locale. Le respect des mesures de sécurité au sein des usines reste néanmoins le principal moyen de prévention de ce type de brûlures méconnues. PMID:26170791

  16. Aqaba-Levant transform-related faults in the Gulf of Suez rift: The Durba-Araba fault, Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Abdeen, Mamdouh M.; Abdelmaksoud, Ashraf S.

    2014-09-01

    The Gulf of Suez rift is dominated by NNW- to NW-striking “Clysmic” faults trending parallel to the rift. In addition there are NNE- and WNW-striking (oblique) faults that trend at an angle to the rift. The Durba-Araba fault (DAF) in southwestern Sinai represents one of several NNE-striking faults. It separates the Durba fault block on its NW from the Araba fault block on its SE. Detailed (1:20,000 scale) field mapping and structural studies of the DAF and the onshore area to the east of Belayim Bay (eastern margin of the central Gulf of Suez rift), indicate that the exposed part of the DAF extends for 7.5 km NNE from the mouth of Wadi Araba, at which point it bends and splays into three N- to NNW striking faults, forming a horse tail structure. The fault shows 4 km of pure sinistral strike-slip displacement. Northerly plunging fault propagation folds in the Phanerozoic rocks adjacent to the DAF accommodated the sinistral displacement. These folds are cut and displaced by the splay faults. Near its northern end, the middle splay fault affects the Pliocene El Qa'a Formation. At Gebel Qabeliat a group of en echelon left-stepping NNE- to N-striking faults overlaps the DAF generating a pull-apart (rhomb) graben, in which Pliocene and Quaternary sediments are downthrown against the Upper Miocene rocks. Kinematic indicators on most of these faults show major sinistral strike-slip movement. Palaeostress analysis of slip striae indicates sub-horizontal ENE to NNE extension, comparable to the present day stress regime. Cross-cutting relationships indicate that the NNE- to N-striking oblique faults are younger than the NW-striking Clysmic faults. These faults are probably presently active since they affect Pliocene and Quaternary sediments. It is proposed that these faults are related to the Aqaba-Levant transform that has been active since the Middle Miocene.

  17. STAR Au + Au Fixed Target Results

    NASA Astrophysics Data System (ADS)

    Meehan, Kathryn; STAR Collaboration

    2015-10-01

    The RHIC Beam Energy Scan (BES) program was proposed to look for the turn-off of signatures of the quark gluon plasma (QGP), search for a possible QCD critical point, and study the nature of the phase transition between hadronic and partonic matter. The results from the NA49 experiment at CERN have been used to claim that the onset of deconfinement occurs at a collision energy around a center-of-mass energy of 7 GeV, the low end of the BES range. Data from lower energies are needed to test if this onset occurs. The goal of the STAR Fixed-Target Program is to extend the collision energy range in BES II with the same detector to energies that are likely below the onset of deconfinement. Currently, STAR has inserted a gold target into the beam pipe and conducted test runs at center-of-mass energies 3.9 and 4.5 GeV. Tests have been done with both Au and Al beams. First physics results from a Coulomb analysis of Au + Au fixed-target collisions, which are found to be consistent with previous experiments, will be presented. These results demonstrate that STAR has good particle identification capabilities in this novel detector setup. Furthermore, the Coulomb potential, which is sensitive to the Z of the projectile and degree of baryonic stopping, will be compared with published results from the AGS. This material is based upon work supported by the National Science Foundation under Grant No. 1068833.

  18. Palynology, palynofacies and petroleum potential of the Upper Cretaceous-Eocene Matulla, Brown Limestone and Thebes formations, Belayim oilfields, central Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    El Diasty, W. Sh.; El Beialy, S. Y.; Abo Ghonaim, A. A.; Mostafa, A. R.; El Atfy, H.

    2014-07-01

    Palynological, palynofacies and organic geochemical results of 46 samples retrieved from the Upper Cretaceous - Eocene Matulla, Brown Limestone and Thebes formations, Belayim oilfields, central Gulf of Suez, Egypt are presented. The two latter formations are not dated palynologically as their lithology is not promising for palynological yield. However the Matulla Formation is dated as Turonian-Santonian age, based on the combined evidence of pollen and dinocysts. Palynofacies analysis carried out under both transmitted and fluorescent microscopy indicated that both the Thebes and Brown Limestone formations are deposited under a distal suboxic-anoxic environment. On the other hand, the Turonian-Santonian Matulla Formation supported the existence of a marginal marine deposition under dysoxic-anoxic basin to proximal suboxic-anoxic shelf environments. Rock-Eval pyrolysis and TOC results indicated that most of the studied formations are thermally immature to marginally mature and have a good petroleum potential. They are organically-rich in both oil- and gas-prone kerogen Type-II and II/III, deposited under marine reducing conditions favorable for hydrocarbon generation and expulsion.

  19. Establishing rapport: Physicians’ practice and attendees’ satisfaction at a Primary Health Care Center, Dammam, Saudi Arabia, 2013

    PubMed Central

    Al Ali, Ayat A.; Elzubair, Ahmed G.

    2016-01-01

    Background: Establishing rapport is an important step in physician–patient communication resulting in a positive effect on patient satisfaction and overall clinical outcomes. However, there is a dearth of studies on the condition of doctor–patient relations in Saudi Arabia. This study was performed to estimate the proportion of physicians who have a good rapport with patients in their practice and the proportion of satisfied attendees. Materials and Methods: A cross-sectional study was conducted at a Primary Health Care Center, Dammam, KSA. The data were collected through a structured self-administered questionnaire given to samples of attendees and physicians to estimate patient satisfaction and the practice of rapport by physicians. Results: A total of 374 attendees and 27 physicians participated in the study. The percentage of physicians who had good rapport was 51.9%. Factors that showed significant relationship with rapport practice were: Physician's age (p = 0.016), physician's experience (p = 0.043), and professional status (p = 0.031). The attendees satisfied with their physician's rapport with them were 50.5%. Factors that showed significant relationship with satisfaction were: Attendee's age (p < 0.0001), educational level (p < 0.0001), having a chronic illness (p < 0.0001), having appointment (p < 0.0001), physicians' professional status (p < 0.0001), and a nonsurgical specialty (p < 0.0001). Conclusion and Recommendation: Physicians' rapport with patients and patients' satisfaction with physicians' empathy is not high. Training is required to optimize physician–patient communication. PMID:26929724

  20. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    SciTech Connect

    Ohno, S.; Shimakura, H.; Tahara, S.; Okada, T.

    2015-08-17

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquid Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.

  1. Electrochemistry of Au(II) and Au(III) pincer complexes: determination of the Au(II)-Au(II) bond energy.

    PubMed

    Dann, Thomas; Roşca, Dragoş-Adrian; Wright, Joseph A; Wildgoose, Gregory G; Bochmann, Manfred

    2013-10-01

    The bond energy of the unsupported Au-Au bond in the Au(ii) dimer [(C(∧)N(∧)C)Au]2 and the difference between Au(III)-OH and Au(III)-H bond enthalpies have been determined experimentally by electrochemical methods, with Au-OH and Au-H complexes showing unexpected differences in their reduction pathways, supported by DFT modelling. PMID:24051607

  2. Magnetoresistance of Au films

    DOE PAGESBeta

    Zhang, D. L.; Song, X. H.; Zhang, X; Zhang, Xiaoguang

    2014-01-01

    Measurement of the magnetoresistance (MR) of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler s rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms.

  3. Eliciting Maltreated and Non-maltreated Children's Transgression Disclosures: Narrative Practice Rapport Building and a Putative Confession

    PubMed Central

    Lyon, Thomas D.; Wandrey, Lindsay; Ahern, Elizabeth; Licht, Robyn; Sim, Megan; Quas, Jodi A.

    2014-01-01

    This study tested the effects of narrative practice rapport building (asking open-ended questions about a neutral event) and a putative confession (telling the child an adult “told me everything that happened and he wants you to tell the truth”) on 4- to 9-year-old maltreated and nonmaltreated children's reports of an interaction with a stranger who asked them to keep toy breakage a secret (N = 264). Only one-third of children who received no interview manipulations disclosed breakage; in response to a putative confession, one-half disclosed. Narrative practice rapport building did not affect the likelihood of disclosure. Maltreated children and nonmaltreated children responded similarly to the manipulations. Neither narrative practice rapport building nor a putative confession increased false reports. PMID:24467688

  4. Antibacterial Au nanostructured surfaces

    NASA Astrophysics Data System (ADS)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06157a

  5. Antibacterial Au nanostructured surfaces.

    PubMed

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-28

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies. PMID:26648134

  6. Surface morphology and optical properties of porphyrin/Au and Au/porphyrin/Au systems

    PubMed Central

    2013-01-01

    Porphyrin/Au and Au/porphyrin/Au systems were prepared by vacuum evaporation and vacuum sputtering onto glass substrate. The surface morphology of as-prepared systems and those subjected to annealing at 160°C was studied by optical microscopy, atomic force microscopy, and scanning electron microscopy techniques. Absorption and luminescence spectra of as-prepared and annealed samples were measured. Annealing leads to disintegration of the initially continuous gold layer and formation of gold nanoclusters. An amplification of Soret band magnitude was observed on the Au/meso-tetraphenyl porphyrin (TPP) system in comparison with mere TPP. Additional enhancement of luminescence was observed after the sample annealing. In the case of sandwich Au/porphyrin/Au structure, suppression of one of the two porphyrins’ luminescence maxima and sufficient enhancement of the second one were observed. PMID:24373347

  7. Surface morphology and optical properties of porphyrin/Au and Au/porphyrin/Au systems

    NASA Astrophysics Data System (ADS)

    Kalachyova, Yevgeniya; Lyutakov, Oleksiy; Solovyev, Andrey; Slepička, Petr; Švorčík, Vaclav

    2013-12-01

    Porphyrin/Au and Au/porphyrin/Au systems were prepared by vacuum evaporation and vacuum sputtering onto glass substrate. The surface morphology of as-prepared systems and those subjected to annealing at 160°C was studied by optical microscopy, atomic force microscopy, and scanning electron microscopy techniques. Absorption and luminescence spectra of as-prepared and annealed samples were measured. Annealing leads to disintegration of the initially continuous gold layer and formation of gold nanoclusters. An amplification of Soret band magnitude was observed on the Au/meso-tetraphenyl porphyrin (TPP) system in comparison with mere TPP. Additional enhancement of luminescence was observed after the sample annealing. In the case of sandwich Au/porphyrin/Au structure, suppression of one of the two porphyrins' luminescence maxima and sufficient enhancement of the second one were observed.

  8. Winning Their Hearts. Members Speak Out: In performances, How do You Establish Rapport between Your Choir and Young Audiences?

    ERIC Educational Resources Information Center

    Montague, Matthew G.

    2005-01-01

    The author discusses techniques on how to establish rapport between the choir and young audiences. According to him, one of the choir's most important assets just might be something he calls access-ability. One of Webster's definitions of "access "is" permission, liberty, or ability to enter, approach, or communicate with." When it comes to…

  9. An XPS study of Al 2Au and AlAu 4 intermetallic oxidation

    NASA Astrophysics Data System (ADS)

    Xu, C.; Sritharan, T.; Mhaisalkar, S. G.; Srinivasan, M.; Zhang, S.

    2007-05-01

    Samples of Al 2Au and AlAu 4 were examined using XPS after controlled oxidation in air. AlAu 4 showed a strong tendency to oxidize compared to Al 2Au. The binding energies (b.e.) of Au 4f and Al 2p XPS emissions were determined for both intermetallics. Heavy oxidation of AlAu 4 resulted in a unique Au 4f emission near the surface which was attributed to Au dissolved in aluminum oxide.

  10. Café au Lait Macule

    MedlinePlus

    ... rash and rashes clinical tools newsletter | contact Share | Café au Lait Macule A parent's guide for infants ... area of pigment near the knee typical of café au lait macules. Overview A café au lait ...

  11. RAPPORT: running scientific high-performance computing applications on the cloud.

    PubMed

    Cohen, Jeremy; Filippis, Ioannis; Woodbridge, Mark; Bauer, Daniela; Hong, Neil Chue; Jackson, Mike; Butcher, Sarah; Colling, David; Darlington, John; Fuchs, Brian; Harvey, Matt

    2013-01-28

    Cloud computing infrastructure is now widely used in many domains, but one area where there has been more limited adoption is research computing, in particular for running scientific high-performance computing (HPC) software. The Robust Application Porting for HPC in the Cloud (RAPPORT) project took advantage of existing links between computing researchers and application scientists in the fields of bioinformatics, high-energy physics (HEP) and digital humanities, to investigate running a set of scientific HPC applications from these domains on cloud infrastructure. In this paper, we focus on the bioinformatics and HEP domains, describing the applications and target cloud platforms. We conclude that, while there are many factors that need consideration, there is no fundamental impediment to the use of cloud infrastructure for running many types of HPC applications and, in some cases, there is potential for researchers to benefit significantly from the flexibility offered by cloud platforms. PMID:23230157

  12. La stigmatisation des PVVIH en Afrique: analyse de ses formes et manifestations au Burkina Faso

    PubMed Central

    Ky-Zerbo, Odette; Desclaux, Alice; Asmar, Khalil El; Makhlouf-Obermeyer, Carla; Msellati, Philippe; Somé, Jean-François

    2014-01-01

    Résumé Introduction l’impact négatif de la stigmatisation sur la prévention du VIH et la prise en charge a été documenté. La stigmatisation a été analysée au plan qualitatif au Burkina Faso, où la prévalence VIH est faible (1 %). Des mesures quantitatives sont encore nécessaires pour identifier les formes et manifestations majeures de la stigmatisation. Méthodologie dans le cadre de l’étude MATCH (Multi-country African Study on Testing and Counselling for HIV), une étude transversale a été conduite auprès de personnes ayant déjà fait le test VIH. Les personnes séropositives ont été interrogées sur les conséquences du résultat VIH+. Leur vécu de la stigmatisation a été évalué à travers 20 indicateurs de manifestations de la stigmatisation, regroupés en trois formes de stigmatisation/discrimination. Résultats au total 219 PVVIH ont été recrutées. L’autostigmatisation est la forme majeure de stigmatisation. Elle est estimée dans cette étude à 46 % comparativement à la stigmatisation dans les relations interpersonnelles évaluée à 40 % et la stigmatisation dans les services de santé qui est de 11 %. L’expérience de la stigmatisation dans les relations interpersonnelles est davantage rapportée par les PVVIH qui ont partagé leur résultat, celles qui ont un faible niveau de scolarisation, les veufs/veuves ou séparés, et les membres d’association. La stigmatisation dans les services de santé est rapportée plus souvent par les membres d’associations. Conclusion les programmes de prise en charge doivent, parallèlement à l’extension des antirétroviraux, intégrer un volet psychologique plus adapté aux besoins. Les activités d’appui psychosocial ciblant davantage l’individu doivent être développées, surtout au sein des associations. PMID:25291886

  13. Fluid dynamical predictions for Au+Au collisions at AGS

    SciTech Connect

    Bravina, L.; Csernai, L.P.; Levai, P. |; Strottmam, D.

    1993-02-01

    Signatures of collective effects are studied in the Quark Gluon String Model and in the Fluid Dynamical Model for Au {plus} Au collisions at 11.6 A GeV. In the fluid dynamical model the dependence of measurables on the QGP formation in the EOS is pointed out, although the max. total amount of pure QGP formed is only 4 fm{sup 3} in these reactions. In QGSM the lifetime and extent of latent energy in strings is studied.

  14. Fluid dynamical predictions for Au+Au collisions at AGS

    SciTech Connect

    Bravina, L.; Csernai, L.P. . Dept. of Physics); Levai, P. . Dept. of Physics Hungarian Academy of Sciences, Budapest . Central Research Inst. for Physics); Strottmam, D. )

    1993-01-01

    Signatures of collective effects are studied in the Quark Gluon String Model and in the Fluid Dynamical Model for Au [plus] Au collisions at 11.6 A GeV. In the fluid dynamical model the dependence of measurables on the QGP formation in the EOS is pointed out, although the max. total amount of pure QGP formed is only 4 fm[sup 3] in these reactions. In QGSM the lifetime and extent of latent energy in strings is studied.

  15. Catalytic Role of Au Nanowires

    NASA Astrophysics Data System (ADS)

    da Silva, Edison; Nascimento, Ana Paula F.; San-Miguel, Miguel A.

    2013-03-01

    The oxidation of CO in linear atomic chains (LACs) of Au nanowires (NW) is studied by means of density functional theory calculations using quasi-static (T=0) and finite temperature ab initio molecular dynamics simulations. The adsorption of O2 and CO molecules on the LAC lead to the formation of an intermediate O2CO complex. Upon thermal activation at room temperature, the complex is able to proceed to oxidation forming a CO2 molecule and leaving an atomic O impurity into the Au LAC. We report the conditions under which this oxidation pathway takes place. This process also explains the appearance of unusual large Au-Au bond distances in the LAC and attributed to the presence of atomic impurities. This work is supported by CNPq, CAPES and FAPESP and FAEPEX. APFN was supported by CNPq. CENAPAD-SP and IFGW are acknowledged for computer time.

  16. La carence en vitamine D chez l'adulte au Gabon: cas isolé ou problème méconnu?

    PubMed Central

    Ntyonga-Pono, Marie-Pierrette

    2014-01-01

    La carence en vitamine D chez l'adulte est un sujet d'actualité à cause de ses multiples effets et de son extension de par le monde. Cependant elle est peu explorée au Gabon et en Afrique centrale en général. Le but de cet article qui rapporte trois cas documentés de carence en vitamine D chez l'adulte au Gabon, est d'attirer l'attention sur l'existence de ce problème même en zone équatoriale ensoleillée. Vu les implications de cette carence dans diverses pathologies osseuses, cardio-vasculaires, métaboliques, infectieuses, auto-immunes, néoplasiques..., des recherches plus approfondies sont nécessaires pour cerner le problème et prendre des mesures appropriées. PMID:25815104

  17. When students from different professions are co-located: the importance of interprofessional rapport for learning to work together.

    PubMed

    Croker, Anne; Fisher, Karin; Smith, Tony

    2015-01-01

    With increasing interest and research into interprofessional learning, there is scope to more deeply understand what happens when students from different professions live and study in the same location. This study aimed to explore the issue of co-location and its effects on how students learn to work with other professions. The setting for this study was a rural health education facility in Australia with close links to local health care and community services. Philosophical hermeneutics informed the research method. Interviews were undertaken with 29 participants, including students, academic educators and clinical supervisors in diagnostic radiography, medicine, nursing, nutrition and dietetics, pharmacy, physiotherapy, occupational therapy, and speech pathology. Photo-elicitation was used to facilitate participant engagement with the topic. The findings foreground the value of interprofessional rapport building opportunities for students learning to work together. Enabled by the proximity of different professions in shared educational, clinical and social spaces, interprofessional rapport building was contingent on contextual conditions (balance of professions, shared spaces and adequate time) and individual's interpersonal capabilities (being interested, being inclusive, developing interpersonal bonds, giving and receiving respect, bringing a sense of own profession and being patient-centred). In the absence of these conditions and capabilities, negative professional stereotypes may be inadvertently re-enforced. From these findings suggestions are made for nurturing interprofessional rapport building opportunities to enable students of different professions to learn to work together. PMID:25010631

  18. Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts.

    PubMed

    Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

    2014-01-01

    Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol. PMID:24797697

  19. Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts

    PubMed Central

    Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

    2014-01-01

    Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol. PMID:24797697

  20. Baryon Rapidity Loss in Relativistic Au+Au Collisions

    SciTech Connect

    Back, B. B.; Betts, R. R.; Chang, J.; Chang, W. C.; Chi, C. Y.; Chu, Y. Y.; Cumming, J. B; Dunlop, J. C.; Eldredge, W.; Fung, S. Y.

    2001-03-05

    An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that display a broad peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a stationary source at midrapidity decreases with increasing beam energy. The data suggest that the stopping is substantially less than complete at these energies.

  1. Impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun

    PubMed Central

    Kalla, Ginette Claude Mireille; Assoumou, Marie-Claire Okomo; Kamgaing, Nelly; Monebenimp, Francisca; Mbopi-Keou, Francois-Xavier

    2015-01-01

    Introduction L'objectif de ce travail était d’évaluer l'impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun. Méthodes Il s'agissait d'une étude rétrospective réalisée de Mai 2003 à Décembre 2012 au CHU de Yaoundé au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’âge moyen était de 54.02±46.34 mois. The sexe ratio était de 0.96 en faveur des garçons. Le diagnostic s’était fait tardivement (74.2%) ainsi que la mise sous traitement (83.3%). Seuls 36 des 116 enfants (31%) avait pu avoir un bilan biologique à l'initiation du traitement antirétroviral et six mois après l'initiation du traitement antirétroviral. Après six mois de traitement, nous avons enregistrés une augmentation significative des paramètres biologiques suivants: taux de glycémie de 0.09g/L (0.75-0.84; p= 0.007), pourcentage de CD4 chez les enfants de moins de 5 ans de 4.62% (20.12-24.75; p = 0.022), valeur absolue de CD4 chez les enfants de plus de 5 ans de 294 cellules/mm3 (151.18-445.18; p = 0.011), le rapport CD4/CD8 de 0.35 (0.55-0.90; p = 0.000). Enfin, après six mois de traitement, on enregistrait une baisse significative de la charge virale du VIH de 3.90 log (5.85-1.95; p = 0.006). Conclusion Il ressort de cette étude que la restauration immunitaire et la suppression virologique peuvent être obtenus après six mois de traitement antirétroviral. Cependant, des efforts doivent encore être faits en ce qui concerne la prise en charge du suivi biologique, gage d'un bon suivi thérapeutique au Cameroun. PMID:26113902

  2. Péritonites infectieuses en dialyse péritonéale continue ambulatoire au CHU de Rabat: profil bactériologique sur trois ans

    PubMed Central

    Lioussfi, Zineb; Rhou, Hakima; Ezzaitouni, Fatima; Ouzeddoun, Naima; Bayahia, Rabea; Benamar, Loubna

    2012-01-01

    Introduction La péritonite infectieuse (PI) est une des complications les plus sévères et les plus fréquentes de la dialyse péritonéale (DP). But: Déterminer le taux des PI et les germes en causes, et évaluer l’efficacité des protocoles thérapeutiques entrepris chez les patients traités par DP au CHU de Rabat. Méthodes Etude rétrospective effectuée en Septembre 2009 chez tous les patients traités par DP continue ambulatoire (DPCA) au CHU de Rabat depuis l’ouverture de l’unité de DP en Juillet 2006. Ont été inclus dans cette étude, tous les patients ayant fait une péritonite. Pour tous nos patients, nous avons relevé les données cliniques, biologiques et bactériologiques. Nous avons également recherché les causes des péritonites, le délai de survenue par rapport au début de la dialyse, et la durée moyenne de formation des patients. Résultats Au cours de la période de l’étude, 28 épisodes de PI sont survenus chez 19 patients dont la moyenne d’âge est de 46±16 (19-78) ans, avec une prédominance masculine (12 hommes/ 7 femmes). Le taux des PI dans notre unité de DP est de 21.07 mois-patients calculé par le RDPLF. Leur délai de survenue par rapport au début de la dialyse au centre est de 7.9 ±8 (1-29) mois. Lors de ces PI, les bactéries à Gram négatif (BGN) ont été retrouvées dans 55% des cas, contre uniquement 45% pour les Gram positifs. Conclusion La PI est une complication grave et redoutable de la DP. Le taux de PI dans notre centre de DPCA est de 21m-p ce qui correspond au taux acceptable définie par les sociétés internationales. Les germes les plus responsables des PI dans notre centre sont les BGN et la contamination semble être manu-portée se faisant essentiellement à partir de la flore environnementale et cutanée. PMID:22593777

  3. Facteurs influençant l'initiation au traitement antirétroviral des personnes vivant avec le VIH dans les Centres de Traitement Agréés de Bamenda et de Bertoua au Cameroun

    PubMed Central

    Mbopi-Keou, Francois-Xavier; Voundi, Esther Voundi; Kalla, Ginette Claude Mireille; Emah, Irène; Angwafo, Fru; Muna, Walinjom

    2014-01-01

    Introduction L'objectif de ce travail était de déterminer les facteurs influençant l'initiation au traitement antirétroviral des personnes vivant avec le VIH (PVVIH) dans les centres de traitements agrées (CTA) de Bamenda et de Bertoua au Cameroun. Méthodes Il s'agissait d'une étude transversale, analytique réalisée de Janvier à Avril 2011, dans les CTA de Bamenda et de Bertoua. Pour cette étude, nous avons obtenu une clairance éthique. Résultats Nous avons étudiés 460 dossiers de patients séropositifs en phase d'initiation au traitement antirétroviral dans les CTA de Bamenda et de Bertoua, 53,9% et 46,1% respectivement. L ‘âge médian était de 36 ans. La plupart des séropositifs à Bertoua (41) avaient fait un dépistage volontaire du VIH par rapport à ceux de Bamenda (22) (p= 0.008). Il y ‘avait plus de VIH de type 1 et 2 dans le CTA de Bamenda (15) par rapport à Bertoua (3) (p= 0.011). La majorité des patients était classé au stade clinique II à Bamenda (54,0%) tandis qu ‘à Bertoua le stade clinique III était prédominant (52,4%) (p = 0,000). Le taux médian de CD4 était de 133 cellules/mm3 dans le CTA de Bamenda et de 175 cellules/mm3 à Bertoua (p = 0,008). La Zidovudine était plus prescrit à Bamenda et le Ténofovir à Bertoua (p = 0,000). L ‘Efavirenz était plus prescrit à Bertoua tandis que la Névirapine l ‘était plus à Bamenda (p = 0,000). Le Lopinavir/r était plus prescrit à Bamenda qu ‘à Bertoua (p = 0,017). Conclusion Il apparait urgent de standardiser la prise en charge des PVVIH dans les CTA du Cameroun. PMID:25184023

  4. A sensitive SERS substrate based on Au/TiO2/Au nanosheets

    NASA Astrophysics Data System (ADS)

    Jiang, Li; Liang, Xiu; You, Tingting; Yin, Penggang; Wang, Hua; Guo, Lin; Yang, Shihe

    2015-05-01

    Sensitive SERS substrates based on Au/TiO2/Au nanosheet have been prepared by physically sputtering Au nanoparticles onto fabricated TiO2 nanosheets. The Au/TiO2/Au nanosheets show much stronger SERS signal as compared to normal Au/Ti substrates by increasing surface area and effectively inducing plasmonic coupling between adjoining Au nanoparticles. In addition, influence factors such as concentration of probe solution and deposition time of gold nanoparticles were discussed. This study provides an easy-prepared and label-free substrate for the detection of biomolecule.

  5. Nuclear Modification of Jet Fragmentation in Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Rowan, Zachary; Phenix Collaboration

    2015-10-01

    The characterization of energy in the quark gluon plasma is facilitated by measurements of modifications to the observed jet fragmentation. A favorable channel of study relies on direct photons created in the initial parton interactions of heavy ion collisions. Such a photon traverses the created medium unscathed and grants us a proxy for the transverse momentum of an away side jet. PHENIX Au+Au data recorded at √{sNN} = 200 GeV during RHIC run 14 benefit from the background rejection capability of the silicon vertex detector, enabling the extraction of a higher purity hadron signal. This advantage, combined with a larger integrated luminosity, allows previous PHENIX measurements of fragmentation functions to be extended to greater jet energies. In this talk, the status of the analysis of direct photon hadron correlations with the new data set will be discussed.

  6. Global polarization measurement in Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Callner, J.; Catu, O.; Cebra, D.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; Moura, M. M. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Horner, M. J.; Huang, H. Z.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kurnadi, P.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Qattan, I. A.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Z.; Surrow, B.; Symons, T. J. M.; Toledo, A. Szanto De; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Webb, J. C.; Westfall, G. D.; , C. Whitten, Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, J.; Wu, Y.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yue, Q.; Yurevich, V. I.; Zawisza, M.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2007-08-01

    The system created in noncentral relativistic nucleus-nucleus collisions possesses large orbital angular momentum. Because of spin-orbit coupling, particles produced in such a system could become globally polarized along the direction of the system angular momentum. We present the results of Λ and Λ¯ hyperon global polarization measurements in Au+Au collisions at sNN=62.4 and 200 GeV performed with the STAR detector at the BNL Relativistic Heavy Ion Collider (RHIC). The observed global polarization of Λ and Λ¯ hyperons in the STAR acceptance is consistent with zero within the precision of the measurements. The obtained upper limit, |PΛ,Λ¯|⩽0.02, is compared with the theoretical values discussed recently in the literature.

  7. Global polarization measurement in Au+Au collisions

    SciTech Connect

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev,V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2007-08-02

    The system created in non-central relativisticnucleus-nucleus collisions possesses large orbital angular momentum. Dueto spin-orbit coupling, particles produced in such a system could becomeglobally polarized along the direction of the system angular momentum. Wepresent the results of Lambda and anti-Lambda hyperon global polarizationmeasurements in Au+Au collisions at sqrt sNN=62.4 GeV and 200 GeVperformed with the STAR detector at RHIC. The observed globalpolarization of Lambda and anti-Lambda hyperons in the STAR acceptance isconsistent with zero within the precision of the measurements. Theobtained upper limit, lbar P Lambda, anti-Lambda rbar<= 0.02, iscompared to the theoretical values discussed recently in theliterature.

  8. d + Au hadron correlation measurements at PHENIX

    SciTech Connect

    Anne M. Sickles

    2014-05-13

    In these proceedings, we discuss recent results from d + Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v2 at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v2 in d + Au to that in p + Pb, Au + Au and Pb + Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.

  9. Two new Myxidium species (Myxosporea: Myxidiidae) infecting the gallbladder of African flying fish, Cheilopogon nigricans and Suez fusilier, Caesio suevicus from the Red Sea, Egypt: a morphological and morphometric study.

    PubMed

    Abdel-Baki, Abdel-Azeem Sh

    2009-08-01

    Myxidium maamouni sp. n. and Myxidium aydai sp. n. were described from the gallbladder of the African flying fish Cheilopogon nigricans and Suez fusilier Caesio suevicus, respectively. Fishes were collected from the Red Sea at Al-Quseir, Egypt. M. maamouni have irregular to mostly rounded polysporous plasmodia with diameter of 27 microm. Spores were sigmoid or S-shaped and sometimes spindle-shaped in the frontal view with smooth valves. They measured 13.5 x 8.0 x 8.2 microm in size. Their polar capsules were equal pyriform and measured 7.0 x 3.2 microm in size with nine to 12 coils. Spores of M. aydai were spindle-shaped in the frontal view with thin smooth valves. They measured 23.0 x 5.6 x 5.5 microm in size. Their polar capsules were pyriform and measured 7.2 x 3.4 microm in size with eight to nine coils. PMID:19347364

  10. Synthesis and optical property characterization of elongated AuPt and Pt@Au metal nanoframes.

    PubMed

    Lee, Sangji; Jang, Hee-Jeong; Jang, Ho Young; Hong, Soonchang; Moh, Sang Hyun; Park, Sungho

    2016-02-18

    We report a facile method to synthesize elongated nanoframes consisting of Pt and Au in solution. Pentagonal Au nanorods served as templates and successfully led to an elongated AuPt nanoframe after etching the core Au. Subsequently, the coating of Au around Pt ridges resulted in Pt@Au metal nanoframes. The resulting elongated nanostructure exhibited 5 well-defined ridges continuously connected along the long axis. During the shape evolution from pure Au nanorods to elongated Pt@Au metal nanoframes, their corresponding localized surface plasmon resonance bands were monitored. Especially, unique surface plasmon features were observed for elongated Pt@Au nanoframes where the short-axis oscillation of surface free electrons is strongly coupled but the long-axis oscillation is not coupled among the ridges. PMID:26859224

  11. Synthesis and optical property characterization of elongated AuPt and Pt@Au metal nanoframes

    NASA Astrophysics Data System (ADS)

    Lee, Sangji; Jang, Hee-Jeong; Jang, Ho Young; Hong, Soonchang; Moh, Sang Hyun; Park, Sungho

    2016-02-01

    We report a facile method to synthesize elongated nanoframes consisting of Pt and Au in solution. Pentagonal Au nanorods served as templates and successfully led to an elongated AuPt nanoframe after etching the core Au. Subsequently, the coating of Au around Pt ridges resulted in Pt@Au metal nanoframes. The resulting elongated nanostructure exhibited 5 well-defined ridges continuously connected along the long axis. During the shape evolution from pure Au nanorods to elongated Pt@Au metal nanoframes, their corresponding localized surface plasmon resonance bands were monitored. Especially, unique surface plasmon features were observed for elongated Pt@Au nanoframes where the short-axis oscillation of surface free electrons is strongly coupled but the long-axis oscillation is not coupled among the ridges.We report a facile method to synthesize elongated nanoframes consisting of Pt and Au in solution. Pentagonal Au nanorods served as templates and successfully led to an elongated AuPt nanoframe after etching the core Au. Subsequently, the coating of Au around Pt ridges resulted in Pt@Au metal nanoframes. The resulting elongated nanostructure exhibited 5 well-defined ridges continuously connected along the long axis. During the shape evolution from pure Au nanorods to elongated Pt@Au metal nanoframes, their corresponding localized surface plasmon resonance bands were monitored. Especially, unique surface plasmon features were observed for elongated Pt@Au nanoframes where the short-axis oscillation of surface free electrons is strongly coupled but the long-axis oscillation is not coupled among the ridges. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08200e

  12. Multifractal structure of speed fluctuations in recurrent streams at 1 AU and near 6 AU

    SciTech Connect

    Burlaga, L.F. )

    1991-08-01

    This paper demonstrates the existence of multifractal structure in the velocity fluctuations associated with recurrent streams at 1 AU and near 6 AU. There is a significant evolution of the multifractal spectrum from 1 AU to 6 AU. At 1 AU the fluctuations on all scales in the indicated range are related to the local speed gradients associated with the stream structure. Near 6 AU the multifractal structure of the speed fluctuations approaches the universal form for intermittent turbulence for months q > 5, and it has approximately the value expected for a set of discontinuities for q = 2.

  13. Multifractal structure of speed fluctuations in recurrent streams at 1 AU and near 6 AU

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.

    1991-01-01

    This paper demonstrates the existence of multifractal structure in the velocity fluctuations associated with recurrent streams at 1 AU and near 6 AU. There is a significant evolution of the multifractal spectrum from 1 AU to 6 AU. At 1 AU the fluctuations on all scales in the indicated range are related to the local speed gradients associated with the stream structure. Near 6 AU the multifractal structure of the speed fluctuations approaches the universal form for intermittent turbulence for moments when q is greater than 5, and it has approximately the value expected for a set of discontinuities for q = 2.

  14. A + (B[subscript 1]) Professor--student Rapport + (B[subscript 2]) Humor + (B[subscript 3]) Student Engagement = (Y) Student Ratings of Instructors

    ERIC Educational Resources Information Center

    Richmond, Aaron S.; Berglund, Majken B.; Epelbaum, Vadim B.; Klein, Eric M.

    2015-01-01

    Teaching effectiveness is often evaluated through student ratings of instruction (SRI). Research suggests that there are many potential factors that can predict student's perceptions of teaching effectiveness such as professor-student rapport, student engagement, and perceived humor of the instructor. Therefore, we sought to assess whether…

  15. Errorless Embedding for Children with On-Task and Conduct Difficulties: Rapport-Based, Success-Focused Intervention in the Classroom

    ERIC Educational Resources Information Center

    Ducharme, Joseph M.; Harris, Kimberly E.

    2005-01-01

    Children exposed to psychosocial stressors often develop behavior disorders that include off-task responding in the classroom. We used errorless embedding, a rapport-based, nonpunitive intervention, to improve on-task behavior in such children. In a multiple-baseline across subjects design, we observed 5 children with severe behavioral…

  16. A + (B[subscript 1]) Professor--student Rapport + (B[subscript 2]) Humor + (B[subscript 3]) Student Engagement = (Y) Student Ratings of Instructors

    ERIC Educational Resources Information Center

    Richmond, Aaron S.; Berglund, Majken B.; Epelbaum, Vadim B.; Klein, Eric M.

    2015-01-01

    Teaching effectiveness is often evaluated through student ratings of instruction (SRI). Research suggests that there are many potential factors that can predict student's perceptions of teaching effectiveness such as professor-student rapport, student engagement, and perceived humor of the instructor. Therefore, we sought to assess whether

  17. New Strategies To Combat Long-Term Unemployment in Belgium, Denmark and the United Kingdom. Synthesis Report = Nouvelles strategies de lutte contre le chomage de longue duree en Belgigue, au Danemark, et au Royaume-Uni. Rapport de synthese.

    ERIC Educational Resources Information Center

    Geers, Frederik; And Others

    This synthesis report provides information to policy makers, practitioners, and researchers on the new strategies and measures adopted in Belgium, Denmark, and the United Kingdom to combat long-term unemployment. It begins with a summary of strategies and measures adopted in each of the three countries. Each country report highlights the following…

  18. New Strategies To Combat Long-Term Unemployment in Belgium, Denmark and the United Kingdom. Synthesis Report = Nouvelles strategies de lutte contre le chomage de longue duree en Belgigue, au Danemark, et au Royaume-Uni. Rapport de synthese.

    ERIC Educational Resources Information Center

    Geers, Frederik; And Others

    This synthesis report provides information to policy makers, practitioners, and researchers on the new strategies and measures adopted in Belgium, Denmark, and the United Kingdom to combat long-term unemployment. It begins with a summary of strategies and measures adopted in each of the three countries. Each country report highlights the following

  19. Etude séro-épidémiologique de la leishmaniose canine au centre du Maroc

    PubMed Central

    Fellah, Hajiba; Doughmi, Oursula; Maniar, Saâd; Lalami, Abdelhakim El Ouali

    2014-01-01

    Dans le monde, la leishmaniose viscérale humaine est connue pour avoir comme principale source d'infection les Canidés domestiques et sauvages. Au centre du Maroc, les données épidémiologiques, cliniques et parasitologiques sur la leishmaniose canine, sont quasiment inexistantes. Ce travail traite une étude prospective au cours de laquelle 61 sérums canins ont été analysés par un test rapide et par l'immunofluorescence indirecte. La sensibilité du test rapide par rapport à celle de l'immunofluorescence indirecte (IFI) est de 33,33%. La fréquence de la maladie chez les chiens s’élève à 9,83% (Test Rapide) et 24,59% (IFI). 73,33% des cas canins positifs à la sérologie sont asymptomatiques. Ce sont les jeunes chiens de moins de 5 ans qui sont les plus fréquemment atteints avec une sensibilité de la race Berger Allmand à l'infection. Cette étude a permis de mettre en évidence la présence de chiens leishmaniens (15 chiens séropositifs parmi 61) et de prouver l'existence du réservoir canin. Une stratégie de prévention active doit être mise en place. PMID:25852791

  20. Pt{sub 3}Au and PtAu clusters: Electronic states and potential energy surfaces

    SciTech Connect

    Dai, D.; Balasubramanian, K.

    1994-03-15

    We carried out complete active space multiconfiguration self-consistent-field calculations followed by multireference singles+doubles configuration interaction with the Davidson correction which included up to 3.55 million configurations employing relativistic effective core potentials on Pt{sub 3}+Au and PtAu clusters. Four low-lying electronic states were identified for Pt{sub 3}+Au. The {sup 2}{ital A}{sub 2} electronic state ({ital C}{sub 3{ital v}}) was found to be the ground state of Pt{sub 3}Au. Spin--orbit effects were found to be significant. We also computed six low-lying electronic states of PtAu and four low-lying electronic states of PtAu{sup +}. The 5/2 ({sup 2}{Delta}) and 0{sup +}({sup 1}{Sigma}{sup +}) states were found to be the ground states of PtAu and PtAu{sup +}, respectively.

  1. Gold nanowired: a linear (Au25)(n) polymer from Au25 molecular clusters.

    PubMed

    De Nardi, Marco; Antonello, Sabrina; Jiang, De-en; Pan, Fangfang; Rissanen, Kari; Ruzzi, Marco; Venzo, Alfonso; Zoleo, Alfonso; Maran, Flavio

    2014-08-26

    Au25(SR)18 has provided fundamental insights into the properties of clusters protected by monolayers of thiolated ligands (SR). Because of its ultrasmall core, 1 nm, Au25(SR)18 displays molecular behavior. We prepared a Au25 cluster capped by n-butanethiolates (SBu), obtained its structure by single-crystal X-ray crystallography, and studied its properties both experimentally and theoretically. Whereas in solution Au25(SBu)18(0) is a paramagnetic molecule, in the crystal it becomes a linear polymer of Au25 clusters connected via single Au-Au bonds and stabilized by proper orientation of clusters and interdigitation of ligands. At low temperature, [Au25(SBu)18(0)]n has a nonmagnetic ground state and can be described as a one-dimensional antiferromagnetic system. These findings provide a breakthrough into the properties and possible solid-state applications of molecular gold nanowires. PMID:25088331

  2. Wetting and energetics of solid Au and Au-Ge/SiC interfaces

    SciTech Connect

    Wang, Z.; Wynblatt, P.

    1998-09-01

    A solid state wetting technique has been used to investigate the effects of alloying Au with Ge on the wetting and energetics of Au/SiC interfaces at 1123 K. Germanium was found to segregate to the Au/SiC interface, thereby lowering the contact angle of Au on SiC from 133 to 110, and doubling the work of adhesion of Au on SiC. Calculations based on a monolayer model predict a segregation of 0.89 monolayers of Ge at the Au/SiC interface for Au containing 2.3 at.% Ge. This agrees reasonably well with a coverage of 0.6 monolayers Ge at the Au/SiC interface obtained by direct measurements based on the crater edge profiling technique. The work also demonstrates that simple models of interfacial composition can be combined with the Gibbs adsorption isotherm to provide reliable estimates of interfacial composition at complex four-component interfaces.

  3. Raman scattering characterization of 1,4-phenylenediisocyanide in Au-Au and Ag-Au Nanogaps

    NASA Astrophysics Data System (ADS)

    Kim, Kwan; Choi, Jeong-Yong; Shin, Kuan Soo

    A nanogap formed by a metal nanoparticle and a flat metal substrate is one kind of "hot site" for surface-enhanced Raman scattering (SERS). In this sense, the characteristics of 1,4-phenylenediisocyanide (1,4-PDI) trapped in a nanogap formed by a flat Au or Ag substrate and 60 nm-sized Au or Ag nanoparticles have been examined by means of Raman scattering spectroscopy. It is noteworthy that the NC stretching band of 1,4-PDI is very susceptible to the measurement condition. The NC stretching band is observed at 2177, 2173, and 2174 cm-1 when 1,4-PDI is trapped in the Au-Au, Ag-Au, and Au-Ag nanogaps, respectively, but the corresponding peak shifts linearly with a slope of as much as 22.4, 28.5, and 31.2 cm-1 V-1, respectively, in the electrochemical environment. On the other hand, the NC stretching peak is found to blue-shift by up to 8, 3, and 5 cm-1, respectively, when the Au-Au, Ag-Au, and Au-Ag nanogaps are exposed to acetic acid. In contrast, in the presence of ammonia, the NC stretching peak is red-shifted by up to 9, 4, and 5 cm-1, respectively. This can be understood by presuming that acetic acid acts as an electron acceptor, while ammonia acts as an electron donor when these volatile organics interact with Au or Ag, thereby resulting in either the increase or the decrease in the surface potential of the nanogap electrodes.

  4. The Electronic Properties and L3 XANES of Au and Nano-Au

    SciTech Connect

    Yiu, Y.M.; Zhang, P.; Sham, T.K.

    2004-04-20

    The electronic properties of Au crystal and nano Au have been investigated by theory and experiment. Molecularly capped nano-Au was synthesized using the two-phase method. Au nano-particles have been characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). They retain the fcc crystal structure. Their sizes have been determined to be in a range from 5.5 nm to 1.7 nm. The L3 X-ray Absorption Near Edge Structure (XANES) of nano-Au and Au foil have been recorded using synchrotron radiation, and examined by theoretical calculation based on the first principles. Both theory and experiment show that the nano-Au particles have essentially all the Au L3 XANES features of bulk Au in the near edge region with less pronounced resonance peaks. It is also shown that nano Au exhibits lower 4f binding energy than bulk Au in good agreement with quantum confined Au systems reported previously.

  5. Serum albumin adsorbed on Au nanoparticles: structural changes over time induced by S-Au interaction.

    PubMed

    Fu, Cuiping; Yang, Huayan; Wang, Mengmeng; Xiong, Huanming; Yu, Shaoning

    2015-02-28

    We report the evolution of the protein secondary structure of HSA adsorbed on AuNPs over time. This evolution is in agreement with the S-Au interaction time determined by Raman spectroscopy. The results indicate that the changes in the secondary structure of HSA are induced by the S-Au interaction. PMID:25642658

  6. The Other Side of Rapport: Data Collection Mode and Interviewer Gender Effects on Sexual Health Reporting in Ghana.

    PubMed

    Agula, Justina; Barrett, Jennifer B; Tobi, Hilde

    2015-09-01

    Accurate data on young people's sexual behaviour and sexual health practice is essential to inform effective interventions and policy. However, little empirical evidence exists to support methodological design decisions in projects assessing young people's sexual health, especially in African contexts. This short report uses original empirical data collected in Ghana in 2012 to assess the effects of data collection mode and interviewer gender on young people's reporting of sexual health and access to supportive sexual health resources. The findings indicate that the effect of data collection mode may vary by gender, and there is no indication of an interviewer gender effect for males in this study. Preliminary results suggest that building strong rapport with research participants in this context may lead to reduced sexual health data quality. These findings merit further investigation and have direct implications for the design of projects measuring sexual health and related variables in Ghana. PMID:26897919

  7. Au nanorod helical superstructures with designed chirality.

    PubMed

    Lan, Xiang; Lu, Xuxing; Shen, Chenqi; Ke, Yonggang; Ni, Weihai; Wang, Qiangbin

    2015-01-14

    A great challenge for nanotechnology is to controllably organize anisotropic nanomaterials into well-defined three-dimensional superstructures with customized properties. Here we successfully constructed anisotropic Au nanorod (AuNR) helical superstructures (helices) with tailored chirality in a programmable manner. By designing the 'X' pattern of the arrangement of DNA capturing strands (15nt) on both sides of a two-dimensional DNA origami template, AuNRs functionalized with the complementary DNA sequences were positioned on the origami and were assembled into AuNR helices with the origami intercalated between neighboring AuNRs. Left-handed (LH) and right-handed (RH) AuNR helices were conveniently accomplished by solely tuning the mirrored-symmetric 'X' patterns of capturing strands on the origami. The inter-rod distance was precisely defined as 14 nm and inter-rod angle as 45°, thus a full helix contains 9 AuNRs with its length up to about 220 nm. By changing the AuNR/origami molar ratio in the assembly system, the average number of AuNR in the helices was tuned from 2 to 4 and 9. Intense chiroptical activities arose from the longest AuNR helices with a maximum anisotropy factor of ∼0.02, which is highly comparable to the reported macroscopic AuNR assemblies. We expect that our strategy of origami templated assembly of anisotropic chiral superstructures would inspire the bottom-up fabrication of optically active nanostructures and shed light on a variety of applications, such as chiral fluids, chiral signal amplification, and fluorescence combined chiral spectroscopy. PMID:25516475

  8. Oxygen-assisted reduction of Au species on Au/SiO2 catalyst in room temperature CO oxidation

    SciTech Connect

    Wu, Zili; Zhou, Shenghu; Zhu, Haoguo; Dai, Sheng; Overbury, Steven {Steve} H

    2008-01-01

    An unexpected oxygen-assisted reduction of cationic Au species by CO was found on a Au/SiO2 catalyst at room temperature; CO oxidation activity increases simultaneously with the reduction of Au species, suggesting the key role of metallic Au played in CO oxidation on Au/SiO2.

  9. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CFR 62.90) via Pay.gov. (p) Repeat participation. A foreign national who enters the United States as... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Au pairs. 62.31 Section 62.31 Foreign Relations....31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange...

  10. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CFR 62.90) via Pay.gov. (p) Repeat participation. A foreign national who enters the United States as... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Au pairs. 62.31 Section 62.31 Foreign Relations....31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange...

  11. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CFR 62.90) via Pay.gov. (p) Repeat participation. A foreign national who enters the United States as... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Au pairs. 62.31 Section 62.31 Foreign Relations....31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange...

  12. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Au pairs. 62.31 Section 62.31 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM Specific Program Provisions § 62.31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange visitor programs under which foreign...

  13. H2O nucleation around Au+.

    PubMed

    Reveles, J Ulises; Calaminici, Patrizia; Beltrn, Marcela R; Kster, Andres M; Khanna, Shiv N

    2007-12-19

    First principles electronic structure calculations have been carried out to investigate the ground state geometry, electronic structure, and the binding energy of [Au(H2O)n]+ clusters containing up to 10 H2O molecules. It is shown that the first coordination shell of Au+ contains two H2O molecules forming a H2O-Au+-H2O structure with C2 symmetry. Subsequent H2O molecules bind to the previous H2O molecules forming stable and fairly rigid rings, each composed of 4 H2O molecules, and leading to a dumbbell structure at [Au(H2O)8]+. The 9th and the 10th H2O molecules occupy locations above the Au+ cation mainly bonded to one H2O from each ring, leading to structures where the side rings are partially distorted and forming structures that resemble droplet formation around the Au+ cation. The investigations highlight quantum effects in nucleation at small sizes and provide a microscopic understanding of the observed incremental binding energy deduced from collision induced dissociation that indicates that [Au(H2O)n]+ clusters with 7-10 H2O molecules have comparable binding energy. The charge on the Au+ is shown to migrate to the outside H2O molecules, suggesting an interesting screening phenomenon. PMID:18034477

  14. Antiproton Production in Au+Au Collisions at 11.7a GeV/c

    SciTech Connect

    Ashktorab, K.; Beavis, D.; Chasman, C.; Chen, Z.; Chu, Y.Y.; Cumming, J.B.; Debbe, R.; Gushue, S.; Kim, E.; Lee, J.; Moskowitz, B.; Muentz, C.; Olness, J.; Remsberg, L.P.; Tannenbaum, M.J.; Videbaek, F.; Zhu, F.; Crawford, H.J.; Engelage, J.; Judd, E.; Chang, J.; Eldredge, W.; Fung, S.; Seto, R.; Xiang, H.; Xu, G.H.; Chi, C.; Chi, C.; Cole, B.A.; Cole, B.A.; Moulson, M.; Moulson, M.; Wang, F.; Wang, F.; Wu, Y.; Wu, Y.; Zajc, W.A.; Zajc, W.A.; Nagamiya, S.; Akiba, Y.; Britt, H.C.; Hansen, L.F.; Luke, J.; Namboodiri, M.N.; Sangster, T.C.; Thomas, J.H.; Garcia, E.; Mignerey, A.; Shea, J.; Ahle, L.; Baker, M.D.; Cianciolo, V.; Dunlop, J.C.; Heintzelman, G.; Ogilvie, C.A.; Soltz, R.; Steadman, S.G.; Stephans, G.S.; Yao, H.; Hamagaki, H.; Hayano, R.S.; Sako, H.; Shigaki, K.; Kumagai, A.; Kurita, K.; Miake, Y.; Ueno-Hayashi, S.; Yagi, K.; Kang, J.; Kim, E.

    1998-09-01

    Antiproton production in 11.7A GeV/c Au+Au collisions over a wide transverse-mass coverage was studied using the AGS-E866 experimental apparatus. The mean transverse kinetic energy increases as a function of centrality and is similar to that of protons. The antiproton yields in Si+Al , Si+Au , and Au+Au collisions are consistent with scaling with the 0.7 power of the number of participant nucleons. Copyright 1998, The American Physical Society

  15. Collagen Crosslinking with Au Nanoparticles

    PubMed Central

    Castaneda, Luciano; Valle, Judith; Yang, Nina; Pluskat, Suzanne; Slowinska, Katarzyna

    2009-01-01

    Tiopronin (N-(2-Mercaptopropionyl)glycine) protected gold nanoparticles (TPAu) were crosslinked to collagen via EDC (1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide) coupling. On average, each TPAu forms 8 amide bonds with collagen lysine moieties. The resulting gels were studied with Environmental-SEM, TEM, micro-DSC, and TNBS assay. The porous structure of collagen was significantly altered by crosslinking, resulting in the reduction of the pore size from ca. 140 μm to less than 1μm depending upon the concentration of nanoparticles. The collagenase biodegradation assay showed improved stability of crosslinked material. The cell viability assay, CellTiter 96®, indicates that the gold nanoparticles are not toxic at the concentrations used in gel synthesis. This new material has potential for the delivery of small molecule drugs, as well as Au nanoparticles for photothermal therapies, imaging, and cell targeting. PMID:18959440

  16. Connected Au network in annealed Ni/Au thin films on p-GaN

    SciTech Connect

    Lee, S. P.; Jang, H. W.; Noh, D. Y.; Kang, H. C.

    2007-11-12

    We report the formation of a connected Au network in annealed Ni/Au thin films on p-GaN, which was studied by scanning electron microscopy, transmission electron microscopy, and synchrotron x-ray diffraction. As the Ni was oxidized into NiO upon annealing at 530 deg. C in air, the Au layer was transformed to an interconnected network with an increased thickness. During annealing, Ni atoms diffuse out onto the Au through defects to form NiO, while Au atoms replace the Ni positions. The Au network grows downward until it reaches the p-GaN substrate, and NiO columns fill the space between the Au network.

  17. Facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala au Cameroun

    PubMed Central

    Mbopi-Keou, Francois-Xavier; Nguefack-Tsague, Georges; Kalla, Ginette Claude Mireille; Abessolo, Stéphanie Abo'o; Angwafo, Fru; Muna, Walinjom

    2014-01-01

    Introduction L'objectif de ce travail était de déterminer les facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala (Région du Sud) au Cameroun. Méthodes Il s'agissait d'une étude transversale, descriptive et analytique qui s'est déroulée de Février à Mai 2011. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’échantillon était constitué de 315 participants dont 181 (57,46%) hommes et 134 (42,54%) femmes. L’âge moyen était de 24,5±8ans (extrême: 15-45ans). Quarante personnes (40) étaient séropositifs, soit une prévalence de l'infection par le VIH de 12,7%. Cette prévalence augmentait significativement (p = 0) avec le nombre de partenaires occasionnels au cours des douze derniers mois, allant de 2,7% chez ceux n'ayant eu aucun partenaire occasionnel à 21,25% chez ceux ayant plus de trois partenaires occasionnels (RC = 9,72; IC = 1,27-74,14; P = 0,03). le fait d’être âgé entre 20 et 24 ans (RC = 4,88; IC = 1,74-13,67; p = 0), avoir plus de trois partenaires sexuels au cours des douze derniers mois (RC = 9,72; IC = 1,27-74,14; p = 0,03), avoir les rapports sexuels avec les prostitués (RC = 2,86; IC = 1,42-5,76; p = 0), avoir eu le chlamydia (RC = 3,00; IC = 1,07-8,39; p = 0,04), avoir eu la syphilis (RC = 3,35; IC = 1,57-7,14; p = 0), avoir des avantages sociaux lors du premier rapport sexuel (RC = 2,57; IC = 1,03-6,43; p = 0,04) constituaient des potentiels facteurs de risque du VIH. Conclusion Il apparait urgent d'intensifier les campagnes de sensibilisation au risque d'infection par le VIH et les maladies sexuellement transmissibles dans le district de santé de Meyomessala PMID:25419299

  18. Thermal and photoinduced reduction of ionic Au(III) to elemental Au nanoparticles by dissolved organic matter in water: possible source of naturally occurring Au nanoparticles.

    PubMed

    Yin, Yongguang; Yu, Sujuan; Liu, Jingfu; Jiang, Guibin

    2014-01-01

    Naturally occurring Au nanoparticles (AuNPs) have been widely observed in ore deposits, coal, soil, and environmental water. Identifying the source of these naturally occurring AuNPs could be helpful for not only the discovery of Au deposits through advanced exploration methods, but also the elucidation of the biogeochemical cycle and environmental toxicity of ionic Au and engineered AuNPs. Here, we investigated the effect of natural/simulated sunlight and heating on the reduction of ionic Au by ubiquitous dissolved organic matter (DOM) in river water. The reductive process probed by X-ray photoelectron spectroscopy revealed that phenolic, alcoholic, and aldehyde groups in DOM act as reductive sites. Long-time exposure with thermal and photoirradiation induced the further fusion and growth of AuNPs to branched Au nanostructure as precipitation. The formation processes and kinetics of AuNPs were further investigated using humic acid (HA) as the DOM model, with comprehensive characterizing methods. We have observed that HA can reduce ionic Au(III) complex (as chloride or hydroxyl complex) to elemental Au nanoparticles under sunlight or heating. In this process, nearly all of the Au(III) could be reduced to AuNPs, in which HA serves as not only the reductive agent, but also the coating agent to stabilize and disperse AuNPs. The size and stability of AuNPs were highly dependent on the concentration ratio of Au(III) to HA. These results imply that, besides biological processes, this thermal or photochemical reduction process is another possible source of naturally occurring AuNPs in natural environments, which possibly has critical impacts on the transport and transformation of Au and engineered AuNPs. PMID:24471802

  19. Self-assembly of thiolated cyanine aggregates on Au(111) and Au nanoparticle surfaces

    NASA Astrophysics Data System (ADS)

    Menéndez, Guillermo O.; Cortés, Emiliano; Grumelli, Doris; Méndez de Leo, Lucila P.; Williams, Federico J.; Tognalli, Nicolás G.; Fainstein, Alejandro; Vela, María Elena; Jares-Erijman, Elizabeth A.; Salvarezza, Roberto C.

    2012-01-01

    Heptamethinecyanine J-aggregates display sharp, intense fluorescence emission making them attractive candidates for developing a variety of chem-bio-sensing applications. They have been immobilized on planar thiol-covered Au surfaces and thiol-capped Au nanoparticles by weak molecular interactions. In this work the self-assembly of novel thiolated cyanine (CNN) on Au(111) and citrate-capped AuNPs from solutions containing monomers and J-aggregates has been studied by using STM, XPS, PM-IRRAS, electrochemical techniques and Raman spectroscopy. Data show that CNN species adsorb on the Au surfaces by forming thiolate-Au bonds. We found that the J-aggregates are preferentially adsorbed on the Au(111) surface directly from the solution while adsorbed CNN monomers cannot organize into aggregates on the substrate surface. These results indicate that the CNN-Au interaction is not able to disorganize the large J-aggregates stabilized by π-π stacking to optimize the S-Au binding site but it is strong enough to hinder the π-π stacking when CNNs are chemisorbed as monomers. The optical properties of the J-aggregates remain active after adsorption. The possibility of covalently bonding CNN J-aggregates to Au planar surfaces and Au nanoparticles controlling the J-aggregate/Au distance opens a new path regarding their improved stability and the wide range of biological applications of both CNN and AuNP biocompatible systems.Heptamethinecyanine J-aggregates display sharp, intense fluorescence emission making them attractive candidates for developing a variety of chem-bio-sensing applications. They have been immobilized on planar thiol-covered Au surfaces and thiol-capped Au nanoparticles by weak molecular interactions. In this work the self-assembly of novel thiolated cyanine (CNN) on Au(111) and citrate-capped AuNPs from solutions containing monomers and J-aggregates has been studied by using STM, XPS, PM-IRRAS, electrochemical techniques and Raman spectroscopy. Data show that CNN species adsorb on the Au surfaces by forming thiolate-Au bonds. We found that the J-aggregates are preferentially adsorbed on the Au(111) surface directly from the solution while adsorbed CNN monomers cannot organize into aggregates on the substrate surface. These results indicate that the CNN-Au interaction is not able to disorganize the large J-aggregates stabilized by π-π stacking to optimize the S-Au binding site but it is strong enough to hinder the π-π stacking when CNNs are chemisorbed as monomers. The optical properties of the J-aggregates remain active after adsorption. The possibility of covalently bonding CNN J-aggregates to Au planar surfaces and Au nanoparticles controlling the J-aggregate/Au distance opens a new path regarding their improved stability and the wide range of biological applications of both CNN and AuNP biocompatible systems. Electronic supplementary information (ESI) available. See DOI: 10.1039/c1nr11039j

  20. Photoionization of Au+, Au2+, and Au3+ ions and developments in the synthesis of the metallofullerene Au@C60

    NASA Astrophysics Data System (ADS)

    Kilcoyne, A. L. David; Muller, Alfred; Schippers, Stefan; Hellhund, Jonas; Borovik, Alexander; Mueller, Allison; Gross, Dylan; Johnson, Andrea; Macaluso, David; A. L. D. Kilcoyne Collaboration

    2015-05-01

    Absolute single photoionization of Au+, Au2+, and Au3+ ions was investigated via the merged-beams technique at AMO Beamline 10.0.1.2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. The absolute single photoionization yield was measured as a function of photon energy for each species from the metastable state ionization threshold region to well above the ground state ionization potential. Additional high-resolution measurements were performed for Au+ and Au2+ ions in the region of the ground and metastable state ionization thresholds to better resolve the detailed resonant structure found therein. This structure was used, along with the reported excited state energy levels of Au+, to preliminarily identify previously unreported excitation levels in all three ions. In addition and as a component of the same program, photoionization studies of the endohedral metallofullerene Au@C60+were performed using endohedral fullerene samples synthesized on-site at Beamline 10.0.1.2 of the ALS.

  1. Significant surface flattening effect by Au addition for Cu growth on Cu3Au(001)

    NASA Astrophysics Data System (ADS)

    Kojima, Takayuki; Mizuguchi, Masaki; Takanashi, Koki

    2014-01-01

    To prepare a flat surface of Cu film on Cu3Au(001), we utilized the effect of Au addition to Cu, and investigated the dependence of the growth mode on the amount of Au added. We grew Cu-x%Au (x = 0-20) films on Cu3Au(001) underlayers by co-deposition and observed the surface morphology by scanning tunneling microscopy. For Cu film without Au addition, three-dimensional islands were observed on the surface while flat two-dimensional surfaces were observed for Cu film with only 2.5%Au addition. This difference in the growth mode was found to be due to surface segregation of Au revealed by in situ Auger electron spectroscopy. It was considered that the Au atoms acted like a surfactant and avoided three-dimensional island growth by suppression of the accumulation of epitaxial strain in Cu-x%Au films. However, the terrace size decreased with x. This decrease was thought to be due to an increase in an effective Ehrlich-Schwoebel barrier. The surface flattening effect by addition of another element would be obtained in other systems as well by employing a suitable element.

  2. Engineered fabrication of ordered arrays of Au-NiO-Au nanowires

    NASA Astrophysics Data System (ADS)

    Perego, Daniele; Franz, Silvia; Bestetti, Massimiliano; Cattaneo, Laura; Brivio, Stefano; Tallarida, Grazia; Spiga, Sabina

    2013-02-01

    In the present paper, a novel method to fabricate ordered arrays of Au/NiO/Au nanowires is described, with the aim of filling the gap between the fundamental study of the electrical properties of scattered single nanowires and the engineered fabrication of nanowire arrays. This approach mainly consists of the following steps: (a) electrodeposition of Au/Ni/Au nanowires into an ordered porous anodic aluminum oxide template; (b) mechanical polishing of the sample to expose the gold tips of Au/Ni/Au nanowires to the template surface; (c) in situ annealing of the Au/Ni/Au nanowires without removing the template. The resulting structure consists in an ordered array of Au/NiO/Au nanowires slightly protruding out of a flat aluminum oxide template. Unlike current approaches, with the described method it is not necessary to remove the template in order to oxidize the middle metal, thus allowing the availability of an entire set of metal/oxide/metal nanowires ordered in a two-dimensional matrix and where single heterojunctions can be accessed individually.

  3. Engineered fabrication of ordered arrays of Au-NiO-Au nanowires.

    PubMed

    Perego, Daniele; Franz, Silvia; Bestetti, Massimiliano; Cattaneo, Laura; Brivio, Stefano; Tallarida, Grazia; Spiga, Sabina

    2013-02-01

    In the present paper, a novel method to fabricate ordered arrays of Au/NiO/Au nanowires is described, with the aim of filling the gap between the fundamental study of the electrical properties of scattered single nanowires and the engineered fabrication of nanowire arrays. This approach mainly consists of the following steps: (a) electrodeposition of Au/Ni/Au nanowires into an ordered porous anodic aluminum oxide template; (b) mechanical polishing of the sample to expose the gold tips of Au/Ni/Au nanowires to the template surface; (c) in situ annealing of the Au/Ni/Au nanowires without removing the template. The resulting structure consists in an ordered array of Au/NiO/Au nanowires slightly protruding out of a flat aluminum oxide template. Unlike current approaches, with the described method it is not necessary to remove the template in order to oxidize the middle metal, thus allowing the availability of an entire set of metal/oxide/metal nanowires ordered in a two-dimensional matrix and where single heterojunctions can be accessed individually. PMID:23291391

  4. Synthesis of Au microwires by selective oxidation of Au-W thin-film composition spreads

    NASA Astrophysics Data System (ADS)

    Hamann, Sven; Brunken, Hayo; Salomon, Steffen; Meyer, Robert; Savan, Alan; Ludwig, Alfred

    2013-02-01

    We report on the stress-induced growth of Au microwires out of a surrounding Au-W matrix by selective oxidation, in view of a possible application as micro-Velcro. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au-W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52 composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35 ?m) and diameter (2 ?m) achieved at the Au48W52 composition are suitable for micro-Velcro applications.

  5. New intermetallics YbAu2In4 and Yb2Au3In5.

    PubMed

    Sebastian, C Peter; Salvador, James; Martin, Joshua B; Kanatzidis, Mercouri G

    2010-11-15

    The intermetallic compounds YbAu(2)In(4) and Yb(2)Au(3)In(5) were obtained as single crystals in high yield from reactions run in liquid indium. Single crystal X-ray diffraction data of YbAu(2)In(4) showed that it crystallizes as a new structure type in the monoclinic space group P2(1)/m and lattice constants a = 7.6536(19) Å, b = 4.5424(11) Å, c = 9.591(2) Å and β = 107.838(4)°. The YbAu(2)In(4) compound is composed of a complex [Au(2)In(4)](3-) polyanionic network in which the rare-earth ions are embedded. Yb(2)Au(3)In(5) crystallizes in the polar space group Cmc2(1) with the Y(2)Rh(3)Sn(5) type structure and lattice constants a = 4.5351(9) Å, b = 26.824(5) Å, and c = 7.4641(15) Å. The gold and indium atoms define a complex three-dimensional [Au(3)In(5)] network with a broad range of Au-In (2.751(2) Å-3.0518(16) Å) and In-In (3.062(3) Å-3.3024(19) Å) distances. Magnetic susceptibility measurements of YbAu(2)In(4) revealed a transition at 25 K. Below the transition, the susceptibility of YbAu(2)In(4) follows Curie-Weiss behavior with an effective paramagnetic moment of 0.79 μ(B)/Yb. Magnetic susceptibility measurements on Yb(2)Au(3)In(5) show a mixed valent ytterbium and the magnetic moment within the linear region (<100 K) of 1.95 μ(B)/Yb. Heat capacity data for YbAu(2)In(4) and Yb(2)Au(3)In(5) give Debye temperatures of 185 and 153 K, respectively. PMID:20961134

  6. Au40: A Large Tetrahedral Magic Cluster

    SciTech Connect

    Jiang, Deen; Walter, Michael

    2011-01-01

    40 is a magic number for tetrahedral symmetry predicted in both nuclear physics and the electronic jellium model. We show that Au{sub 40} could be such a magic cluster from density functional theory-based basin hopping for global minimization. The putative global minimum found for Au{sub 40} has a twisted pyramid structure, reminiscent of the famous tetrahedral Au{sub 20}, and a sizable HOMO-LUMO gap of 0.69 eV, indicating its molecular nature. Analysis of the electronic states reveals that the gap is related to shell closings of the metallic electrons in a tetrahedrally distorted effective potential.

  7. Volcano-sedimentary characteristics in the Abu Treifiya Basin, Cairo-Suez District, Egypt: Example of dynamics and fluidization over sedimentary and volcaniclastic beds by emplacement of syn-volcanic basaltic rocks

    NASA Astrophysics Data System (ADS)

    Khalaf, E. A.; Abdel Motelib, A.; Hammed, M. S.; El Manawi, A. H.

    2015-12-01

    This paper describes the Neogene lava-sediment mingling from the Abu Treifiya Basin, Cairo-Suez district, Egypt. The lava-sediment interactions as peperites have been identified for the first time at the study area and can be used as paleoenvironmental indicators. The identification of peperite reflects contemporaneous time relationship between volcanism and sedimentation and this finding is of primary importance to address the evolutional reconstruction of the Abu Treifiya Basin. Characterization of the facies architecture and textural framework of peperites was carried out through detailed description and interpretation of their outcrops. The peperites and sedimentary rocks are up to 350 m thick and form a distinct stratigraphic framework of diverse lithology that is widespread over several kilometers at the study area. Lateral and vertical facies of the peperites vary from sediment intercalated with the extrusive/intrusive basaltic rocks forming peperitic breccias to lava-sediment contacts at a large to small scales, respectively. Peperites encompass five main facies types ascribed to: (i) carbonate sediments-hosted fluidal and blocky peperites, (ii) lava flow-hosted blocky peperites, (iii) volcaniclastics-hosted fluidal and blocky peperites, (iv) sandstone/siltstone rocks-hosted blocky peperites, and (iv) debris-flows-hosted blocky peperites. Soft sediment deformation structures, vesiculated sediments, sediments filled-vesicles, and fractures in lava flows indicate that lava flows mingled with unconsolidated wet sediments. All the peperites in this study could be described as blocky or fluidal, but mixtures of different clast shapes occur regardless of the host sediment. The presence of fluidal and blocky juvenile clasts elucidates different eruptive styles, reflecting a ductile and brittle fragmentation. The gradual variation from fluidal to blocky peperite texture, producing the vertical grading is affected by influencing factors, e.g., the viscosity, magma temperature, confining pressure, sediment fluidization, and vapor film at the magma-sediment interactions. Peperites in the study area record deposition within a shallow marine and fluvio-lacustrine environment accumulated in a rift-related basin developed during pre- to syn-rift phase, respectively. The facies transitions (peperites) in this area resulted from the explosive and sediment depositional processes, which were mingled separately by volcanism under contrast geological conditions. The development of such contrast in the depositional sequences reflects variation in the accommodation to sediment supply in the same accumulation space inside the depocenters during the rifting of the Abu Treifiya Basin. Hydrothermal mineralizations comprising quartz and carbonate are restricted to peperites and lava flows.

  8. A comparative study of Ge/Au/Ni/Au-based ohmic contact on graphene

    NASA Astrophysics Data System (ADS)

    Wenchao, Min; Hao, Sun; Qilian, Zhang; Zhiying, Chen; Yanhui, Zhang; Guanghui, Yu; Xiaowei, Sun

    2014-05-01

    Superior graphene—metal contacts can improve the performance of graphene devices. We report on an experimental demonstration of Ge/Au/Ni/Au-based ohmic contact on graphene. The transfer length method (TLM) is adopted to measure the resistivity of graphene-metal contacts. We designed a process flow, which can avoid residual photoresist at the interface of metal and graphene. Additionally, rapid thermal annealing (RTA) at different temperatures as a post-processing method is studied to improve graphene—metal contact. The results reveal that the contact resistivity of graphene and Ge/Au/Ni/Au can reach 10-5 Ω·cm2 after RTA, and that 350 °C is optimum annealing temperature for the contact of graphene—Ge/Au/Ni/Au. This paper provides guidance for fabrication and applications of graphene devices.

  9. Au, Ge and AuGe Nanoparticles Fabricated by Laser Ablation

    SciTech Connect

    Musaev, O.R.; Sutter, E.; Wrobel, J.M.; Kruger, M.B.

    2012-02-01

    A eutectic AuGe target immersed in distilled water was ablated by pulsed ultraviolet laser light. The structure of the ablated material was investigated by high-resolution transmission electron microscopy (HRTEM). The images show formation of nanowire structures of AuGe up to 100 nm in length, with widths of 5-10 nm. These nanostructures have Ge content significantly lower than the target material. Electron diffraction demonstrates that they crystallize in the {alpha}-AuGe structure. For comparison, laser ablation of pure Au and pure Ge targets was also performed under the same conditions. HRTEM shows that Ge forms spherical nanoparticles with a characteristic size of {approx}30 nm. Au forms spherical nanoparticles with diameters of {approx}10 nm. Similar to AuGe, it also forms chainlike structures with substantially lower aspect ratio.

  10. Ir-induced activation of Au towards CO adsorption: Ir films deposited on Au{111}

    NASA Astrophysics Data System (ADS)

    Zhang, Tianfu; Driver, Stephen M.; Pratt, Stephanie J.; Jenkins, Stephen J.; King, David A.

    2016-06-01

    We have investigated the interaction of CO with Ir/Au{111} bimetallic surfaces, and the influence of morphology changes as Ir moves sub-surface into the Au bulk, using reflection-absorption infrared spectroscopy (RAIRS). The presence of Ir stabilises CO on exposed regions of the Au surface at temperatures up to around 200 K: we attribute this to low-coordinated Au sites, probably associated with lifting of the clean-surface 'herringbone' reconstruction by Ir deposition. The highest density of active Au sites is obtained after annealing the bimetallic surface to 500-600 K: we attribute this to morphology changes associated with the movement of Ir into bulk Au.

  11. RHIC Au beam in Run 2014

    SciTech Connect

    Zhang, S. Y.

    2014-09-15

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014 is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.

  12. Counterion-Mediated Assembly of Spherical Nucleic Acid-Au Nanoparticle Conjugates (SNA-AuNPs)

    NASA Astrophysics Data System (ADS)

    Kewalramani, Sumit; Moreau, Liane; Guerrero-García, Guillermo; Mirkin, Chad; Olvera de La Cruz, Monica; Bedzyk, Michael; Afosr Muri Team

    2015-03-01

    Controlled crystallization of colloids from solution has been a goal of material scientists for decades. Recently, nucleic acid functionalized spherical Au nanoparticles (SNA-AuNPs) have been programmed to assemble in a wide variety of crystal structures. In this approach, the assembly is driven by Watson-Crick hybridization between DNAs coating the AuNPs. Here, we show that counterions can induce ordered assembly of SNA-AuNPs in bulk solutions, even in the absence of base pairing interactions. The electrostatics-driven assembly of spherical nucleic acid-Au nanoparticle conjugates (SNA-AuNPs) is probed as a function of counterion concentration and counterion valency [ +1 (Na+) or +2 (Ca2+) ] by in situ solution X-ray scattering. Assemblies of AuNPs capped with single-stranded (ss-) or double-stranded (ds-) DNA are examined. SAXS reveals disordered (gas-like) --> face-centered-cubic (FCC) --> glass-like phase transitions with increasing solution ionic strength. These studies demonstrate how non-base-pairing interactions can be tuned to create crystalline assemblies of SNA-AuNPs. The dependence of the inter-SNA-AuNP interactions on counterion valency and stiffness of the DNA corona will be discussed.

  13. DFT study on cysteine adsorption mechanism on Au(111) and Au(110)

    SciTech Connect

    Buimaga-Iarinca, Luiza; Floare, Calin G.; Calborean, Adrian; Turcu, Ioan

    2013-11-13

    Periodic density functional theory calculations were used to investigate relevant aspects of adsorption mechanisms of cysteine dimers in protonated form on Au(111) and Au(110) surfaces. The projected densities of states are explicitly discussed for all main chemical groups of cysteine, i.e. the amino group (NH2), the thiol group (SH) and the carboxylic group (COOH) to identify differences in adsorption mechanism. Special emphasis is put on the analysis of changes in the electronic structure of molecules adsorbed on Au(111) and Au(110) surfaces as well as the accompanying charge transfer mechanisms at molecule-substrate interaction.

  14. Systematic measurements of identified particle spectra in pp, d+Au, and Au+Au collisions at the STAR detector

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bruna, E.; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Callner, J.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; Silva, C. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gaillard, L.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jin, F.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Levine, M. J.; Li, C.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitchell, J.; Mohanty, B.; Molnar, L.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Reed, R.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X.-H.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Tram, V. N.; Trattner, A. L.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; van Leeuwen, M.; Molen, A. M. Vander; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasilevski, I. M.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, H.; Zhang, S.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zuo, J. X.

    2009-03-01

    Identified charged-particle spectra of π±, K±, p, and pmacr at midrapidity (|y|<0.1) measured by the dE/dx method in the STAR (solenoidal tracker at the BNL Relativistic Heavy Ion Collider) time projection chamber are reported for pp and d+Au collisions at sNN=200 GeV and for Au+Au collisions at 62.4, 130, and 200 GeV. Average transverse momenta, total particle production, particle yield ratios, strangeness, and baryon production rates are investigated as a function of the collision system and centrality. The transverse momentum spectra are found to be flatter for heavy particles than for light particles in all collision systems; the effect is more prominent for more central collisions. The extracted average transverse momentum of each particle species follows a trend determined by the total charged-particle multiplicity density. The Bjorken energy density estimate is at least several GeV/fm3 for a formation time less than 1 fm/c. A significantly larger net-baryon density and a stronger increase of the net-baryon density with centrality are found in Au+Au collisions at 62.4 GeV than at the two higher energies. Antibaryon production relative to total particle multiplicity is found to be constant over centrality, but increases with the collision energy. Strangeness production relative to total particle multiplicity is similar at the three measured RHIC energies. Relative strangeness production increases quickly with centrality in peripheral Au+Au collisions, to a value about 50% above the pp value, and remains rather constant in more central collisions. Bulk freeze-out properties are extracted from thermal equilibrium model and hydrodynamics-motivated blast-wave model fits to the data. Resonance decays are found to have little effect on the extracted kinetic freeze-out parameters because of the transverse momentum range of our measurements. The extracted chemical freeze-out temperature is constant, independent of collision system or centrality; its value is close to the predicted phase-transition temperature, suggesting that chemical freeze-out happens in the vicinity of hadronization and the chemical freeze-out temperature is universal despite the vastly different initial conditions in the collision systems. The extracted kinetic freeze-out temperature, while similar to the chemical freeze-out temperature in pp, d+Au, and peripheral Au+Au collisions, drops significantly with centrality in Au+Au collisions, whereas the extracted transverse radial flow velocity increases rapidly with centrality. There appears to be a prolonged period of particle elastic scatterings from chemical to kinetic freeze-out in central Au+Au collisions. The bulk properties extracted at chemical and kinetic freeze-out are observed to evolve smoothly over the measured energy range, collision systems, and collision centralities.

  15. Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR

    SciTech Connect

    STAR Coll

    2009-04-11

    Identified charged particle spectra of {pi}{sup {+-}}, K{sup {+-}}, p and {bar p} at mid-rapidity (|y| < 0.1) measured by the dE/dx method in the STAR-TPC are reported for pp and d + Au collisions at {radical}s{sub NN} = 200 GeV and for Au + Au collisions at 62.4 GeV, 130 GeV, and 200 GeV. Average transverse momenta, total particle production, particle yield ratios, strangeness and baryon production rates are investigated as a function of the collision system and centrality. The transverse momentum spectra are found to be flatter for heavy particles than for light particles in all collision systems; the effect is more prominent for more central collisions. The extracted average transverse momentum of each particle species follows a trend determined by the total charged particle multiplicity density. The Bjorken energy density estimate is at least several GeV/fm{sub 3} for a formation time less than 1 fm/c. A significantly larger net-baryon density and a stronger increase of the net-baryon density with centrality are found in Au + Au collisions at 62.4 GeV than at the two higher energies. Antibaryon production relative to total particle multiplicity is found to be constant over centrality, but increases with the collision energy. Strangeness production relative to total particle multiplicity is similar at the three measured RHIC energies. Relative strangeness production increases quickly with centrality in peripheral Au + Au collisions, to a value about 50% above the pp value, and remains rather constant in more central collisions. Bulk freeze-out properties are extracted from thermal equilibrium model and hydrodynamics-motivated blast-wave model fits to the data. Resonance decays are found to have little effect on the extracted kinetic freeze-out parameters due to the transverse momentum range of our measurements. The extracted chemical freeze-out temperature is constant, independent of collision system or centrality; its value is close to the predicted phase-transition temperature, suggesting that chemical freeze-out happens in the vicinity of hadronization and the chemical freezeout temperature is universal despite the vastly different initial conditions in the collision systems. The extracted kinetic freeze-out temperature, while similar to the chemical freeze-out temperature in pp, d + Au, and peripheral Au + Au collisions, drops significantly with centrality in Au + Au collisions, whereas the extracted transverse radial flow velocity increases rapidly with centrality. There appears to be a prolonged period of particle elastic scatterings from chemical to kinetic freeze-out in central Au + Au collisions. The bulk properties extracted at chemical and kinetic freeze-out are observed to evolve smoothly over the measured energy range, collision systems, and collision centralities.

  16. XAFS studies of Au nanocrystals passivated by different surfactants

    NASA Astrophysics Data System (ADS)

    Li, Yuanyuan; Cheng, Hao; Yang, Lina; Sun, Zhihu; Wei, Shiqiang

    2013-04-01

    The electronic and atomic structures of Au nanocrystals affected by different surfactants (PPh3, PVP, and dodecanethiol) capping were studied by X-ray absorption fine structure (XAFS) at Au L3-edge. For PPh3, PVP, and dodecanethiol-capped Au nanocrystals, the surface Au atoms interact with P, O, and S atoms respectively; however, only for dodecanethiol-capped Au nanocrystals, a significant electron transfer between Au and S atoms is observed. The extend-XAFS results reveal that the atomic structure disorder of Au-Au shell gradually increases from 0.0095 to 0.0152 when the surfactants goes from PPh3 to dodecanethiol. These results suggest that the surfactants would change the electronic and atomic structures of Au nanocrystals rather than merely passivates on the surface of Au nanocrystals.

  17. Visualizing Au-Au bond formation in solution with femtosecond X-ray scattering

    NASA Astrophysics Data System (ADS)

    Adachi, Shin-Ichi

    2015-05-01

    Bond formation is an essential process in chemical reactions, but it is challenging to keep track of detailed atomic movements associated with bond formation because of its bimolecular nature. Bond formation in solution phase has been especially elusive because it is difficult to initiate and follow such diffusion-limited bimolecular processes with ultrafast time resolution. In this regard, a Au oligomer complex, [Au(CN)]n-, offers a good model system in which to study the dynamics of bond formation in solution.Using femtosecond time-resolved X-ray scattering, we successfully visualized in real time the birth of a gold trimer complex, [Au(CN)2-]3,that occurs via photoinduced formation of Au-Au covalent bonds. The ground state of the trimer has Au atoms that are weakly bound to each other by aurophilic interaction and aligned in a bent geometry. Upon photoexcitation, the ground state rapidly converts into the first excited state where Au-Au covalent bonds are formed among Au atoms aligned in a linear geometry. Subsequently, the state transforms to a triplet state in 1.6 ps while accompanying further contraction of Au-Au bonds by 0.1 Å. Later, the triplet state of the trimer converts to a tetramer on nanosecond time scale. This work showcases the possibility of tracking detailed structural changes in solution with sub-ps temporal and sub-angstrom spatial resolutions, thanks to the advent of X-ray free electron lasers and the advance of data analysis of time-resolved solution scattering data.

  18. 100-MeV proton beam intensity measurement by Au activation analysis using 197Au(p, pn)196Au and 197Au(p, p3n)194Au reactions

    NASA Astrophysics Data System (ADS)

    Mokhtari Oranj, Leila; Jung, Nam-Suk; Oh, Joo-Hee; Lee, Hee-Seock

    2016-05-01

    The proton beam intensity of a 100-MeV proton linac at the Korea Multi-purpose Accelerator Complex (KOMAC) was measured by an Au activation analysis using 197Au(p, pn)196Au and 197Au(p, p3n)194Au reactions to determine the accuracy and precision of beam intensity measurement using Gafchromic film dosimetry method. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of Au, Al foils and Pb plates. The yields of produced radio-nuclei in Au foils were obtained by gamma-ray spectroscopy. The FLUKA code was employed to calculate the energy spectrum of protons onto the front surface of Au foils located at three different depth points of the target and also to investigate the condition of incident beam on the target. A good agreement was found between the beam intensity measurements using the activation analysis method at three different depth points of the target. An excellent agreement was also observed between the beam intensity measurements using the Au activation analysis method and the dosimetry method using Gafchromic film.

  19. Suppression of ϒ production in d +Au and Au+Au collisions at √{sNN}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hill, K.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wimsatt, G.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2014-07-01

    We report measurements of ϒ meson production in p + p, d +Au, and Au +Au collisions using the STAR detector at RHIC. We compare the ϒ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au +Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for ϒ (1 S + 2 S + 3 S) in the rapidity range | y | < 1 in d +Au collisions of RdAu = 0.79 ± 0.24 (stat.) ± 0.03 (syst.) ± 0.10 (p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au +Au collisions, we measure a nuclear modification factor of RAA = 0.49 ± 0.1 (stat.) ± 0.02 (syst.) ± 0.06 (p + psyst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state ϒ mesons in Au +Au collisions. The additional suppression in Au +Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d +Au is still needed before any definitive statements about the nature of the suppression in Au +Au can be made.

  20. Transient field fluctuations effects in d+Au and Au+Au collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Topor Pop, V.; Barrette, J.; Gale, C.; Jeon, S.; Gyulassy, M.; Bellwied, R.

    2007-01-15

    The effect of fluctuations of strong color electric fields (SCF) on the baryon production in d+Au and Au+Au collisions at 200A GeV is studied in the framework of the HIJING/BB v2.0 model. It is shown that the dynamics of the production process deviates considerably from calculations based on Schwinger-like estimates for homogeneous and constant color fields. An increase of the string tension from {kappa}{sub 0}=1 GeV/fm, to in medium mean values of 1.5 to 2.0 GeV/fm and 2.0 to 3.0 GeV/fm for d+Au and Au+Au, respectively, results in a consistent description of the observed nuclear modification factors R{sub dAu} and R{sub AuAu} [that relates (d)Au+Au and p+p collisions], and point to the relevance of fluctuations of transient color fields. The differences between nuclear modification factors R{sub AuAu} and R{sub CP} (that relates central and peripheral collisions) are also discussed. The measurement of multistrange (anti)hyperons ({xi},{omega}) yields would provide a crucial test of the importance of SCF fluctuations at RHIC energies.

  1. The electrooxidation-induced structural changes of gold di-superatomic molecules: Au23vs. Au25.

    PubMed

    Matsuo, Shota; Yamazoe, Seiji; Goh, Jing-Qiang; Akola, Jaakko; Tsukuda, Tatsuya

    2016-02-01

    The gold cluster compounds Au38(SC2H4Ph)24 and [Au25(PPh3)10(SC2H4Ph)5Cl2](2+) are known to possess bi-icosahedral Au23 and Au25 cores, respectively, inside their ligand shells. These Au cores can be viewed as quasi-molecules composed of two Au13 superatoms sharing three and one Au(+) atoms, respectively. In the present work, we studied the structural changes of these gold di-superatomic molecules upon electrooxidation via spectroelectrochemical techniques, X-ray absorption fine structure analysis, and density functional theory calculations. The Au23 core was electrochemically stable, but the Au25 core underwent irreversible structural change. This marked difference in the stability of the oxidized states is ascribed to differences in the bonding scheme of Au13 units and/or the bonding nature of the protecting ligands. PMID:26806844

  2. Aspects épidémiologiques des fractures de membres liées à l'exercice de la fonction militaire au Togo

    PubMed Central

    Akpoto, Yao Messanvi; Abalo, Anani; Gnandi-pio, Faré; Sonhaye, Lantam; Tchaou, Mazamaesso; Sama, Hamza Doles; Assenouwe, Sarakawabalo; Lamboni, Damessane; Amavi, Kossigan Adodossi; Adam, Saliou; Kpelao, Essossinam; Tengue, Kodjo; Songne-Gnamkoulamba, Badjona

    2015-01-01

    Le but de notre étude était de déterminer la fréquence des fractures de membres liées à l'exercice de la fonction militaire au sein des Forces de Défense et de Sécurité en milieu africain en vue de ressortir l'impact des différentes circonstances de survenue. Nous avons entrepris une étude rétrospective descriptive allant du 1er janvier 2004 au 31 décembre 2013. Elle a concerné les agents des forces de défense et de sécurité traités pour des fractures de membres au cours de cette période. Sept cent quatre (704) cas de fractures de membres ont été dénombrés. L’âge moyen des patients était de 30,57 ans avec des extrêmes de 19 et 55 ans. La prédominance masculine était nette (95,71%). L'Armée de Terre (51,05%) et la Gendarmerie Nationale (38,86%) étaient les plus représentées. Les hommes du rang étaient majoritaires (43,08%), suivis des sous-officiers (32,59%). La fréquence annuelle des fractures de membres en rapport avec la profession militaire était de 63 cas. Les fractures de jambe étaient les lésions les plus recensées (32,96%). Les Formations et les stages militaires ont été les circonstances de survenue les plus rencontrées (42,60%), suivies des accidents de la circulation (39,43%). La perte des journées de service liée à ces lésions était estimée à 14009 jours par an. Les fractures de jambes occupent le premier rang des fractures de membres en rapport avec l'exercice de la profession militaire. Les formations-stages militaires et les accidents de la voie publique en sont les deux grandes circonstances de survenue. PMID:27081434

  3. Electrochemical Characterization of Protein Adsorption onto YNGRT-Au and VLGXE-Au Surfaces

    PubMed Central

    Trzeciakiewicz, Hanna; Esteves-Villanueva, Jose; Soudy, Rania; Kaur, Kamaljit; Martic-Milne, Sanela

    2015-01-01

    The adsorption of the proteins CD13, mucin and bovine serum albumin on VLGXE-Au and YNGRT-Au interfaces was monitored by electrochemical impedance spectroscopy in the presence of [Fe(CN)6]3−/4−. The hydrophobicity of the Au surface was tailored using specific peptides, blocking agents and diluents. The combination of blocking agents (ethanolamine or n-butylamine) and diluents (hexanethiol or 2-mercaptoethanol) was used to prepare various peptide-modified Au surfaces. Protein adsorption onto the peptide-Au surfaces modified with the combination of n-butylamine and hexanethiol produced a dramatic decrease in the charge transfer resistance, Rct, for all three proteins. In contrast, polar peptide-surfaces induced a minimal change in Rct for all three proteins. Furthermore, an increase in Rct was observed with CD13 (an aminopeptidase overexpressed in certain cancers) in comparison to the other proteins when the VLGXE-Au surface was modified with n-butylamine as a blocking agent. The electrochemical data indicated that protein adsorption may be modulated by tailoring the peptide sequence on Au surfaces and that blocking agents and diluents play a key role in promoting or preventing protein adsorption. The peptide-Au platform may also be used for targeting cancer biomarkers with designer peptides. PMID:26262621

  4. Using supported Au nanoparticles as starting material for preparing uniform Au/Pd bimetallic catalysts

    SciTech Connect

    Villa, Alberto; Prati, Laura; Su, Dangshen; Wang, Di; Veith, Gabriel M

    2010-01-01

    One of the best methods for producing bulk homogeneous (composition) supported bimetallic AuPd clusters involves the immobilization of a protected Au seed followed by the addition of Pd. This paper investigates the importance of this gold seed in controlling the resulting bimetallic AuPd clusters structures, sizes and catalytic activities by investigating three different gold seeds. Uniform Au-Pd alloy were obtained when a steric/electrostatic protecting group, poly(vinyl alcohol) (PVA), was used to form the gold clusters on activated carbon (AC). In contrast Au/AC precursors prepared using Au nanoparticles with only electrostatic stabilization (tetrakis(hydroxypropyl)phosphonium chloride (THPC)), or no stabilization (magnetron sputtering) produced inhomogeneous alloys and segregation of the gold and palladium. The uniform alloyed catalyst (Pd{at}Au{sub PVA}/AC) is the most active and selective catalyst, while the inhomogenous catalysts are less active and selective. Further study of the PVA protected Au clusters revealed that the amount of PVA used is also critical for the preparation of uniform alloyed catalyst, their stability, and their catalytic activity.

  5. Electrochemical Characterization of Protein Adsorption onto YNGRT-Au and VLGXE-Au Surfaces.

    PubMed

    Trzeciakiewicz, Hanna; Esteves-Villanueva, Jose; Soudy, Rania; Kaur, Kamaljit; Martic-Milne, Sanela

    2015-01-01

    The adsorption of the proteins CD13, mucin and bovine serum albumin on VLGXE-Au and YNGRT-Au interfaces was monitored by electrochemical impedance spectroscopy in the presence of [Fe(CN)6](3-/4-). The hydrophobicity of the Au surface was tailored using specific peptides, blocking agents and diluents. The combination of blocking agents (ethanolamine or n-butylamine) and diluents (hexanethiol or 2-mercaptoethanol) was used to prepare various peptide-modified Au surfaces. Protein adsorption onto the peptide-Au surfaces modified with the combination of n-butylamine and hexanethiol produced a dramatic decrease in the charge transfer resistance, Rct, for all three proteins. In contrast, polar peptide-surfaces induced a minimal change in Rct for all three proteins. Furthermore, an increase in Rct was observed with CD13 (an aminopeptidase overexpressed in certain cancers) in comparison to the other proteins when the VLGXE-Au surface was modified with n-butylamine as a blocking agent. The electrochemical data indicated that protein adsorption may be modulated by tailoring the peptide sequence on Au surfaces and that blocking agents and diluents play a key role in promoting or preventing protein adsorption. The peptide-Au platform may also be used for targeting cancer biomarkers with designer peptides. PMID:26262621

  6. The extraction characteristic of Au-Ag from Au concentrate by thiourea solution

    NASA Astrophysics Data System (ADS)

    Kim, Bongju; Cho, Kanghee; On, Hyunsung; Choi, Nagchoul; Park, Cheonyoung

    2013-04-01

    The cyanidation process has been used commercially for the past 100 years, there are ores that are not amenable to treatment by cyanide. Interest in alternative lixiviants, such as thiourea, halogens, thiosulfate and malononitrile, has been revived as a result of a major increase in gold price, which has stimulated new developments in extraction technology, combined with environmental concern. The Au extraction process using the thiourea solvent has many advantages over the cyanidation process, including higher leaching rates, faster extraction time and less than toxicity. The purpose of this study was investigated to the extraction characteristic of Au-Ag from two different Au concentrate (sulfuric acid washing and roasting) under various experiment conditions (thiourea concentration, pH of solvent, temperature) by thiourea solvent. The result of extraction experiment showed that the Au-Ag extraction was a fast extraction process, reaching equilibrium (maximum extraction rate) within 30 min. The Au-Ag extraction rate was higher in the roasted concentrate than in the sulfuric acid washing. The higher the Au-Ag extraction rate (Au - 70.87%, Ag - 98.12%) from roasted concentrate was found when the more concentration of thiourea increased, pH decreased and extraction temperature increased. This study informs extraction method basic knowledge when thiourea was a possibility to eco-/economic resources of Au-Ag utilization studies including the hydrometallurgy.

  7. Odd-Even Pattern Observed in Polyaniline/(Au0 – Au8) Composites

    SciTech Connect

    Jonke, Alex P.; Josowicz, Mira A.; Janata, Jiri

    2012-01-12

    Theoretically predicted effect of odd-even pattern of electron pairing on behavior of gold clusters in polyaniline/AuN (N = 0 to 8) has been confirmed experimentally. In these composites the atomic Au clusters with even number of atoms exhibit higher catalytic activity for electrochemical oxidation of n-propanol in 1 M NaOH than the odd-number atoms clusters. Also, infrared spectroscopy shows that even numbered PANI/AuN composites affect the N-H stretching vibration more strongly than the corresponding odd numbered ones. This behavior matches the theoretically predicted variations of HOMO-LUMO gap energy and the stability of the atomic Au clusters. It also agrees with the earlier experimental work in which the UPS spectra of isolated, mass-selected Au clusters have been reported.

  8. Coinfection pulmonaire par pneumocystis jirovecii et pseudomonas aeruginosa au cours du SIDA: à propos de deux cas

    PubMed Central

    Mamoudou, Savadogo; Bellaud, Guillaume; Ana, Canestri; Gilles, Pialoux

    2015-01-01

    Rapporter deux cas cliniques de coinfections pulmonaires par Pneumocystis jirovecii et par Pseudomonas aeruginosa chez des patients vivant avec le VIH. Les deux patients étaient âgés respectivement de 32 ans et 46 ans. Un patient a été pris en charge à l'hôpital Yalgado Ouédraogo de Ouagadougou au Burkina Faso et l'autre a été pris en charge à l'hôpital Ténon de Paris, en France. Les deux souffraient de pneumopathie confirmée à la radiographie et à la tomodensitométrie. L'un des patients était sévèrement immuno déprimé, contrairement à l'autre. L'examen bactériologique dans les crachats avait permis d'isoler Pseudomonas aeruginosa et Pneumocystis jirovecii chez les deux patients. Sous traitement, l’évolution a été favorable. Les coinfections morbides sont relativement fréquentes chez les patients vivant avec le VIH. Devant une symptomatologie respiratoire du sujet vivant avec le VIH, il faut savoir rechercher en plus du Bacille de Koch, Pneumocystis jirovecii et Pseudomonas aeruginosa par un lavage broncho alvéolaire. PMID:26516396

  9. Jets and dijets in Au+Au and p+p collisions at RHIC

    SciTech Connect

    Hardtke, D.; STAR Collaboration

    2002-12-09

    Recent data from RHIC suggest novel nuclear effects in the production of high p{sub T} hadrons. We present results from the STAR detector on high p{sub T} angular correlations in Au+Au and p+p collisions at {radical}S = 200 GeV/c. These two-particle angular correlation measurements verify the presence of a partonic hard scattering and fragmentation component at high p{sub T} in both central and peripheral Au+Au collisions. When triggering on a leading hadron with p{sub T}>4 GeV, we observe a quantitative agreement between the jet cone properties in p+p and all centralities of Au+Au collisions. This quantitative agreement indicates that nearly all hadrons with p{sub T}>4 GeV/c come from jet fragmentation and that jet fragmentation properties are not substantially modified in Au+Au collisions. STAR has also measured the strength of back-to-back high p{sub T} charged hadron correlations, and observes a small suppression of the back-to-back correlation strength in peripheral collisions, and a nearly complete disappearance o f back-to-back correlations in central Au+Au events. These phenomena, together with the observed strong suppression of inclusive yields and large value of elliptic flow at high p{sub T}, are consistent with a model where high p{sub T} hadrons come from partons created near the surface of the collision region, and where partons that originate or propagate towards the center of the collision region are substantially slowed or completely absorbed.

  10. Spectra and ratios of identified particles in Au+Au and d+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Conesa del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, S. H.; Kim, Y.-J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kleinjan, D.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; Means, N.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Nouicer, R.; Nyanin, A. S.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2013-08-01

    The transverse momentum (pT) spectra and ratios of identified charged hadrons (π±, K±, p, p¯) produced in sNN=200 GeV Au+Au and d+Au collisions are reported in five different centrality classes for each collision species. The measurements of pions and protons are reported up to pT=6 GeV/c (5 GeV/c), and the measurements of kaons are reported up to pT=4 GeV/c (3.5 GeV/c) in Au+Au (d+Au) collisions. In the intermediate pT region, between 2 and 5 GeV/c, a significant enhancement of baryon-to-meson ratios compared to those measured in p+p collisions is observed. This enhancement is present in both Au+Au and d+Au collisions and increases as the collisions become more central. We compare a class of peripheral Au+Au collisions with a class of central d+Au collisions which have a comparable number of participating nucleons and binary nucleon-nucleon collisions. The pT-dependent particle ratios for these classes display a remarkable similarity, which is then discussed.

  11. Profil des diabétiques en hémodialyse chronique: étude multicentrique au Maroc

    PubMed Central

    Kabbali, Nadia; Mikou, Souad; El Pardiya, Nada Tazi; El Bardai, Ghita; Arrayhani, Mohamed; Houssaini, Tarik Sqalli

    2014-01-01

    Introduction Le diabète représente la première cause de mortalité par insuffisance rénale au Maroc. Sa prévalence selon l'Enquête Nationale sur la Population et la Santé Familiale de 2011 est de 3,3% [1]. Le but de ce travail est de déterminer la prévalence et d’étudier le profil clinique des diabétiques en hémodialyse chronique au Maroc. Méthodes Il s'agit d'une étude transversale multicentrique incluant 2066 hémodialysés chroniques dans les 39 centres d'hémodialyse de quatre régions marocaines. Résultats La prévalence du diabète en hémodialyse est 21,6%. L’âge moyen 59±13,2 ans (26-87). Le sex-ratio est de 1,9. L'IMC moyen est de 24,5 ± 4,4 kg/m2 (15-41). 42 patients sont porteurs d′une hépatite virale. La durée moyenne en HD est 39,3± 67 mois. 57% des patients gardent une diurèse résiduelle versus 43% chez les non diabétiques. Par rapport à ces derniers, nous avons noté plus d'HTA (64% versus 45%), plus de complications cardiovasculaires (23% versus 12%), un âge plus avancé à l'initiation de l'hémodialyse (55,5 versus 47 ans) et un taux de FAV proximales plus important. Conclusion La prévalence des diabétiques en hémodialyse est relativement élevée au Maroc sans tenir compte des patients qui ne bénéficient pas d’épuration extra-rénale pour des raisons socio-économiques. Le taux élevé de mortalité est imputable au retard et/ou à l'absence de la prise en charge néphrologique des diabétiques. Dans nos régions où le système sanitaire dispose de faible moyen, l'accent doit être mis sur le dépistage précoce de la néphropathie chez le diabétique. PMID:25374630

  12. Surpoids et obésité dans la population au-dessus de 20 ans en milieu urbain bamakois (Mali)

    PubMed Central

    Oumar Bâ, Hamidou; Menta, Ichaka; Camara, Youssouf; Sangaré, Ibrahima; Sidibé, Noumou; Doumbia, Seydou; Diarra, Mamadou Bocary

    2014-01-01

    Introduction Il est question dans notre travail d’étudier le SP et l'OB et les facteurs associés dans la population âgée de 20 ans ou plus. Méthodes Notre échantillon a été obtenu à partir d'une enquête sur les pathologies cardiovasculaires dans le District de Bamako et impliquant 2199 sujets de 5-104 ans, en sélectionnant tous les sujets âgés d'au moins 20 ans (1162). Pour chaque sujet, l'IMC, rapport taille / hanche et le tour de taille ont été déterminées. Les données ont été analysées avec SPSS 12. Résultats L’âge moyen était de 36,86 années, 61,4% étaient des femmes, 49,7% dans le secteur informel et 38,0% avaient réalisé l'enseignement primaire. Facteurs de risque cardiovasculaires étaient l'inactivité physique (72,4%), le tabagisme (12,2%) et hypertension (26,7%). La prévalence de l'obésité était de 8,8 et 14,7% respectivement sur la base de l'indice de masse et le tour de taille. Conclusion Le SP et l'OB sont à prendre en compte dans les mesures de politique sanitaire que dans la pratique quotidienne des professionnels de santé, il est peut-être plus utile d'utiliser plusieurs paramètres pour être à même de bien stratifier nos patients par rapport à leur risque. PMID:25932065

  13. Synthesis and characterization in AuCu–Si nanostructures

    SciTech Connect

    Novelo, T.E.; Amézaga-Madrid, P.; Maldonado, R.D.; Oliva, A.I.; Alonzo-Medina, G.M.

    2015-03-15

    Au/Cu bilayers with different Au:Cu concentrations (25:75, 50:50 and 75:25 at.%) were deposited on Si(100) substrates by thermal evaporation. The thicknesses of all Au/Cu bilayers were 150 nm. The alloys were prepared by thermal diffusion into a vacuum oven with argon atmosphere at 690 K during 1 h. X-ray diffraction analysis revealed different phases of AuCu and CuSi alloys in the samples after annealing process. CuSi alloys were mainly obtained for 25:75 at.% samples, meanwhile the AuCuII phase dominates for samples prepared with 50:50 at.%. Additionally, the Au:Cu alloys with 75:25 at.%, produce Au{sub 2}Cu{sub 3} and Au{sub 3}Cu phases. The formed alloys were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) to study the morphology and the elemental concentration of the formed alloys. - Highlights: • AuCu/Si alloy thin films were prepared by thermal diffusion. • Alloys prepared with 50 at.% of Au produce the AuCuII phase. • Alloys prepared with 75 at.% of Au produce Au{sub 3}Cu and Au{sub 2}Cu{sub 3} phases. • All alloys present diffusion of Si and Cu through the CuSi alloy formation.

  14. Heterostructured CIGS-Au nanoparticles: from Au-CIGS side-by-side structure to Au-core/CIGS-shell configuration

    NASA Astrophysics Data System (ADS)

    Xu, Yeming; Li, Quan

    2011-08-01

    Heterostructured Au-Copper Indium Gallium Selenide (CIGS) nanoparticles (nps) with Au-CIGS side-by-side and Au-core/CIGS-shell configurations have been synthesized in a controllable manner using seed mediated growth. Detailed microstructure analysis reveals that (112) planes in the tetragonal chalcopyrite CIGS serve as the predominant termination surfaces during single phase CIGS nanoparticle growth. Preferential nucleation of Au on such planes determines the Au-CIGS side-by-side configuration when the pre-synthesized CIGS nps are used as the seeds for further Au growth. Reversing the growth sequence by employing Au nano-seeds results in Au-core/CIGS-shell configuration, as determined by the non-preferential nucleation of CIGS on the spherical Au nanoparticle surface. The different morphological configurations of the heterostructures are found to modify the surface plasmon resonance of Au in the corresponding samples.Heterostructured Au-Copper Indium Gallium Selenide (CIGS) nanoparticles (nps) with Au-CIGS side-by-side and Au-core/CIGS-shell configurations have been synthesized in a controllable manner using seed mediated growth. Detailed microstructure analysis reveals that (112) planes in the tetragonal chalcopyrite CIGS serve as the predominant termination surfaces during single phase CIGS nanoparticle growth. Preferential nucleation of Au on such planes determines the Au-CIGS side-by-side configuration when the pre-synthesized CIGS nps are used as the seeds for further Au growth. Reversing the growth sequence by employing Au nano-seeds results in Au-core/CIGS-shell configuration, as determined by the non-preferential nucleation of CIGS on the spherical Au nanoparticle surface. The different morphological configurations of the heterostructures are found to modify the surface plasmon resonance of Au in the corresponding samples. Electronic supplementary information (ESI) available: The schematic of the (112) planes of CIS tetragonal chalcopyrite structure and various Au-CIGS side-by-side heterostructures (including one-to-one and multiple-to-one morphologies, which were synthesized at modified conditions). See DOI: 10.1039/c1nr10268k

  15. Structure determination of [Au18(SR)14].

    PubMed

    Das, Anindita; Liu, Chong; Byun, Hee Young; Nobusada, Katsuyuki; Zhao, Shuo; Rosi, Nathaniel; Jin, Rongchao

    2015-03-01

    Unravelling the atomic structures of small gold clusters is the key to understanding the origin of metallic bonds and the nucleation of clusters from organometallic precursors. Herein we report the X-ray crystal structure of a charge-neutral [Au18(SC6H11)14] cluster. This structure exhibits an unprecedented bi-octahedral (or hexagonal close packing) Au9 kernel protected by staple-like motifs including one tetramer, one dimer, and three monomers. Until the present, the [Au18(SC6H11)14] cluster is the smallest crystallographically characterized gold cluster protected by thiolates and provides important insight into the structural evolution with size. Theoretical calculations indicate charge transfer from surface to kernel for the HOMO-LUMO transition. PMID:25619892

  16. Au nanoparticles films used in biological sensing

    NASA Astrophysics Data System (ADS)

    Rosales Pérez, M.; Delgado Macuil, R.; Rojas López, M.; Gayou, V. L.; Sánchez Ramírez, J. F.

    2009-05-01

    Lactobacillus para paracasei are used commonly as functional food and probiotic substances. In this work Au nanoparticles self-assembled films were used for Lactobacillus para paracasei determination at five different concentrations. Functionalized substrates were immersed in a colloidal solution for one and a half hour at room temperature and dried at room temperature during four hours. After that, drops of Lactobacillus para paracasei in aqueous solution were put into the Au nanoparticles film and let dry at room temperature for another two hours. Infrared spectroscopy in attenuated total reflectance sampling mode was used to observe generation peaks due to substrate silanization, enhancement of Si-O band intensity due to the Au colloids added to silanized substrate and also to observe the enhancement of Lactobacillus para paracasei infrared intensity of the characteristic frequencies at 1650, 1534 and 1450 cm-1 due to surface enhancement infrared absorption.

  17. Au plasmonics in a WS2-Au-CuInS2 photocatalyst for significantly enhanced hydrogen generation

    NASA Astrophysics Data System (ADS)

    Cheng, Zhongzhou; Wang, Zhenxing; Shifa, Tofik Ahmed; Wang, Fengmei; Zhan, Xueying; Xu, Kai; Liu, Quanlin; He, Jun

    2015-11-01

    Promoting the activities of photocatalysts is still the critical challenge in H2 generation area. Here, a Au plasmon enhanced photocatalyst of WS2-Au-CuInS2 is developed by inserting Au nanoparticles between WS2 nanotubes and CuInS2 (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS2-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS2-CIS, CIS-Au, WS2-Au, and WS2-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimize the type-II structures for photocatalytic water splitting.

  18. Resistive switching characteristics of Au/P-doped NiO/Au segmented nanowires synthesized by electrochemical deposition

    NASA Astrophysics Data System (ADS)

    Lee, Saeeun; Kim, Donguk; Eom, Hyeonjin; Kim, Woo-byoung; Yoo, Bongyoung

    2014-02-01

    In this paper, we detail the synthesis and characteristics of Au/NiO/Au segmented nanowire-based resistive switching memory devices. The fabrication of the memory devices involves the step-by-step electrodeposition of Au-Ni-Au into an anodic aluminum oxide template followed by the thermal oxidation process to make NiO. The unipolar resistive change is observed in Au/NiO/Au nanowires exhibiting a set voltage of 0.6 V and a reset voltage of 1 V with a current compliance of 10 mA. Au diffused Au into NiO during the thermal oxidation lowers the resistance of NiO and the forming voltage. The change in the switching behavior from unipolar to bipolar is achieved by doping approximately 3 at. % phosphorous in the interface of NiO and a Au electrode.

  19. Desulfurization of thiophene on Au/TiC(001): Au-C interactions and charge polarization.

    PubMed

    Rodriguez, José A; Liu, Ping; Takahashi, Yoshiro; Nakamura, Kenichi; Viñes, Francesc; Illas, Francesc

    2009-06-24

    Photoemission and first-principles DF calculations were used to study the interaction of thiophene with TiC(001) and Au/TiC(001) surfaces. The adsorption strength of thiophene on TiC(001) is weak, and the molecule desorbs at temperatures below 200 K. The molecule binds to Ti centers of TiC(001) through its sulfur atom with negligible structural perturbations. In spite of the very poor desulfurization performance of TiC(001) or Au(111), a Au/TiC(001) system displays a hydrodesulfurization activity higher than that of conventional Ni/MoS(x) catalysts. The Au<-->TiC(001) interactions induce a polarization of electron density around Au which substantially increases the chemical reactivity of this metal. Au nanoparticles drastically increase the hydrodesulfurization activity of TiC(001) by enhancing the bonding energy of thiophene and by helping in the dissociation of H(2) to produce the hydrogen necessary for the hydrogenolysis of C-S bonds and the removal of sulfur. H(2) spontaneously dissociates on small two-dimensional clusters of gold in contact with TiC(001). On these systems, the adsorption energy of thiophene is 0.45-0.65 eV larger than that on TiC(001) or Au(111). Thiophene binds in a eta(5) configuration with a large elongation (approximately 0.2 A) of the C-S bonds. PMID:19530731

  20. Au-Ag@Au Hollow Nanostructure with Enhanced Chemical Stability and Improved Photothermal Transduction Efficiency for Cancer Treatment.

    PubMed

    Jiang, Tongtong; Song, Jiangluqi; Zhang, Wenting; Wang, Hao; Li, Xiaodong; Xia, Ruixiang; Zhu, Lixin; Xu, Xiaoliang

    2015-10-01

    Despite the fact that Au-Ag hollow nanoparticles (HNPs) have gained much attention as ablation agents for photothermal therapy, the instability of the Ag element limits their applications. Herein, excess Au atoms were deposited on the surface of a Au-Ag HNP by improving the reduction power of l-ascorbic acid (AA) and thereby preventing the reaction between HAuCl4 and the Ag element in the Au-Ag alloy nanostructure. Significantly, the obtained Au-Ag@Au HNPs show excellent chemical stability in an oxidative environment, together with remarkable increase in extinction peak intensity and obvious narrowing in peak width. Moreover, finite-difference time-domain (FDTD) was used to simulate the optical properties and electric field distribution of HNPs. The calculated results show that the proportion of absorption cross section in total extinction cross section increases with the improvement of Au content in HNP. As predicted by the theoretical calculation results, Au-Ag@Au nanocages (NCs) exhibit a photothermal transduction efficiency (η) as high as 36.5% at 808 nm, which is higher than that of Au-Ag NCs (31.2%). Irradiated by 808 nm laser at power densities of 1 W/cm(2), MCF-7 breast cancer cells incubated with PEGylated Au-Ag@Au NCs were seriously destroyed. Combined together, Au-Ag@Au HNPs with enhanced chemical stability and improved photothermal transduction efficiency show superior competitiveness as photothermal agents. PMID:26371629

  1. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    NASA Astrophysics Data System (ADS)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche constructiviste en enseignement representent les plus grands obstacles a la construction des modeles en classe. Mots-cles : Modeles et modelisation, biologie, conceptions, modes d'utilisation, constructivisme, enseignement, secondaire.

  2. Robust Au-Ag-Au bimetallic atom-scale junctions fabricated by self-limited Ag electrodeposition at Au nanogaps.

    PubMed

    Hwang, Tai-Wei; Bohn, Paul W

    2011-10-25

    Atom-scale junctions (ASJs) exhibit quantum conductance behavior and have potential both for fundamental studies of adsorbate-mediated conductance in mesoscopic conductors and as chemical sensors. Electrochemically fabricated ASJs, in particular, show the stability needed for molecular detection applications. However, achieving physically robust ASJs at high yield is a challenge because it is difficult to control the direction and kinetics of metal deposition. In this work, a novel electrochemical approach is reported, in which Au-Ag-Au bimetallic ASJs are reproducibly fabricated from an initially prepared Au nanogap by sequential overgrowth and self-limited thinning. Applying a potential across specially prepared Au nanoelectrodes in the presence of aqueous Ag(I) leads to preferential galvanic reactions resulting in the deposition of Ag and the formation of an atom-scale junction between the electrodes. An external resistor is added in series with the ASJ to control self-termination, and adjusting solution chemical potential (concentration) is used to mediate self-thinning of junctions. The result is long-lived, mechanically stable ASJs that, unlike previous constructions, are stable in flowing solution, as well as to changes in solution media. These bimetallic ASJs exhibit a number of behaviors characteristic of quantum structures, including long-lived fractional conductance states, that are interpreted to arise from two or more quantized ASJs in series. PMID:21928783

  3. Azimuthal di-hadron correlations in d+ Au and Au + Au collisions at sNN=200 GeV measured at the STAR detector

    NASA Astrophysics Data System (ADS)

    Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barnby, L. S.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Calderón de La Barca Sánchez, M.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Davila Leyva, A.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Derevschikov, A. A.; Derradi de Souza, R.; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Dutta Mazumdar, M. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Evdokimov, O.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Horner, M. J.; Huang, B.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitrovski, M. K.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldag, E. W.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sangaline, E.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Leeuwen, M.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xie, W.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, J. B.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, J.; Zhong, C.; Zhou, J.; Zhou, W.; Zhu, X.; Zhu, Y. H.; Zoulkarneev, R.; Zoulkarneeva, Y.; STAR Collaboration

    2010-08-01

    Yields, correlation shapes, and mean transverse momenta pT of charged particles associated with intermediate- to high-pT trigger particles (2.5Au and Au + Au collisions at sNN=200 GeV are presented. For associated particles at higher pT≳2.5 GeV/c, narrow correlation peaks are seen in d+ Au and Au + Au, indicating that the main production mechanism is jet fragmentation. At lower associated particle pT<2 GeV/c, a large enhancement of the near- (Δϕ~0) and away-side (Δϕ~π) associated yields is found, together with a strong broadening of the away-side azimuthal distributions in Au + Au collisions compared to d+ Au measurements, suggesting that other particle production mechanisms play a role. This is further supported by the observed significant softening of the away-side associated particle yield distribution at Δϕ~π in central Au + Au collisions.

  4. Production of ω mesons in p + p, d + Au, Cu + Cu, and Au + Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Al-Jamel, A.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bjorndal, M. T.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Chai, J.-S.; Chang, B. S.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S.-Y.; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Gastineau, F.; Germain, M.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Hur, M. G.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawagishi, T.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kelly, S.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E. J.; Kim, S. H.; Kim, Y.-J.; Kim, Y.-S.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Li, X. H.; Lichtenwalner, P.; Liebing, P.; Lim, H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Norman, B. E.; Nouicer, R.; Nyanin, A. S.; Nystrand, J.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Samsonov, V.; Sano, S.; Sato, H. D.; Sato, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, K. H.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.

    2011-10-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has measured ω meson production via leptonic and hadronic decay channels in p+p, d+Au, Cu+Cu, and Au+Au collisions at sNN = 200 GeV. The invariant transverse momentum spectra measured in different decay modes give consistent results. Measurements in the hadronic decay channel in Cu+Cu and Au+Au collisions show that ω production has a suppression pattern at high transverse momentum, similar to that of π0 and η in central collisions, but no suppression is observed in peripheral collisions. The nuclear modification factors, RAA, are consistent in Cu+Cu and Au+Au collisions at similar numbers of participant nucleons.

  5. A novel Au SINE sequence found in a gymnosperm.

    PubMed

    Yagi, Eiki; Akita, Toru; Kawahara, Taihachi

    2011-01-01

    Although many SINE families have been identified in the animal kingdom, only a few SINE families have been identified in plants, and their distribution is somewhat limited. The Au SINE (Au) has been found discontinuously in basal angiosperms, monocots, and eudicots. In this study, we examined the presence of the Au in gymnosperms and ferns by PCR using internal primers for Au. As a result, we found Au in a gymnosperm species, Ephedra ciliata. Therefore, Au was supposed to be present in the common ancestor of angiosperms and gymnosperms. The Au in E. ciliate was 15 bp shorter than the consensus sequence, which is similar to the Au SINE found in Glycine. However, the 3'end of the Au found in E. ciliate was more similar to the 3'end of the Medicago-type Au than that of the Glycine-type Au. A phylogenetic tree indicated that the Au sequence from E. ciliate is more closely related to the sequence found in Glycine than that found in Medicago/Lotus. These results indicated that Au were present in both angiosperms and gymnosperms. PMID:21498919

  6. Infra-red spectroscopy of size selected Au25, Au38 and Au144 ligand protected gold clusters.

    PubMed

    Farrag, Mostafa; Tschurl, Martin; Dass, Amala; Heiz, Ulrich

    2013-08-14

    Through the discovery of ligand protected metal clusters with cores of a precise number of atoms, the exploration of the third dimension of the periodic table for fundamental research and also for applications has become less remote. So far, the exact number of metal atoms in the core has been determined unambiguously only using mass spectrometry and single crystal X-ray diffraction. Gold clusters protected by 2-phenylethanethiol ligands, for instance, show distinct magic numbers that correspond to either electronic or geometric shell closings. For efficient control of their synthesis simple-to-use in situ spectroscopies are required. In the specific case of Au25(SCH2CH2Ph)18 clusters (1) we found a distinct shift of the aromatic C-H stretching band from 3030-3100 cm(-1) to below 3000 cm(-1) whose origin is discussed as an electronic interaction of the aromatic rings of the ligands with each other or with the gold core. This IR-feature is specific for Au25; the spectra of Au38(SCH2CH2Ph)24 (2) and Au144(SCH2CH2Ph)60 (3) clusters do not show this distinct shift and their IR-spectra in the C-H stretching regime are similar to that of the bare ligand. This significant change in the IR spectrum of Au25(SCH2CH2Ph)18 is not only of fundamental interest but also allows for in situ determination of the purity and monodispersity of the sample using FTIR spectroscopy during synthesis. PMID:23788003

  7. Suppression of Upsilon production in d + Au and Au + Au collisions at root s(NN) = 200 GeV (vol 735, pg 127, 2014)

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Gliske, S.; Krueger, K.; Spinka, H. M.; Underwood, D. G.

    2014-07-30

    We report measurements of Υ meson production in p + p, d +Au, and Au+Aucollisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Υ (1S + 2S + 3S) in the rapidity range |y| < 1 in d + Aucollisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Υ mesons in Au + Aucollisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.

  8. Radiotherapy Improvements by Using Au Nanoparticles.

    PubMed

    Torrisi, Lorenzo

    2015-01-01

    Au nanoparticles can be prepared inside biological solutions and incorporated in special molecules for their transport through blood, drugs and proteins up to the tumour sites or directly injected in their volume when it is possible. The Au nanoparticles are biocompatible and can be accepted locally in the organism also at relatively high concentrations. The use of Au nanoparticles injected in the tumour site enhances significantly the effective atomic number of the medium, depending on the used concentration, and consequently the proton and electron energy loss and the X-ray absorption coefficient determining an increment of the local absorbed dose during radiotherapy. Traditional radiotherapy using electrons, X-rays and gamma rays, and innovative protontherapy can benefit the increment of the effective atomic number of the tissue in the presence of Au-nanoparticles embedded in the tumour volume with an adaptive up-take procedure. This method decreases the dose released to the healthy tissues permitting a better cantering of the irradiated targets and shielding the healthy tissue placed behind the tumour. The presented theoretical study approach permits to evaluate an enhancement of the radiotherapy dose of the order of 1 % using 60 MeV protons, of the order of 10% using 6 MeV electrons and of the order of 100 % using 100 keV X-ray photons. Here, we also disccused for patents relaed to the topic. PMID:27009126

  9. Cyclotrimerization of arylalkynes on Au(111).

    PubMed

    Liu, Jia; Ruffieux, Pascal; Feng, Xinliang; Müllen, Klaus; Fasel, Roman

    2014-10-01

    Surface-assisted cyclotrimerization of arylalkynes was studied on Au(111) by means of scanning tunneling microscopy (STM) under ultra-high vacuum (UHV) conditions. Upon thermal activation, cyclotrimerization of 1,3,5-tris-(4-ethynylphenyl)benzene proceeds readily and with high selectivity, and results in two-dimensional covalently bonded polyphenylene nanostructures exhibiting a honeycomb topology. PMID:25110877

  10. Adsorption of 5-halouracils on Au(111)

    NASA Astrophysics Data System (ADS)

    Plekan, O.; Feyer, V.; Tsud, N.; Vondráček, M.; Cháb, V.; Matolín, V.; Prince, K. C.

    2012-02-01

    The immobilization of 5-halouracils on Au(111) has been studied by soft X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Multilayer and monolayer films of 5-chlorouracil were deposited on the Au(111) surface by evaporation in vacuum while films of 5-bromouracil were absorbed in two modes: from the gas phase under ultrahigh vacuum conditions and from solution. The photoemission spectra of C, N and O 1s, Br 3d and Cl 2p as well as the absorption spectra at the N and O K-edges were measured for monolayers of 5-halouracil films and the nature of the bonding with the Au(111) surface has been determined. From the angular dependence of the NEXAFS spectra at the O and K-edges, we conclude that these 5-halouracils are lying nearly parallel to the Au(111) surface. Distinct chemical states and surface adsorption geometry of the 5-BrU molecules for monolayer coverage prepared in two different ways have been found.

  11. Nanoporous Au: an unsupported pure gold catalyst?

    SciTech Connect

    Wittstock, A; Neumann, B; Schaefer, A; Dumbuya, K; Kuebel, C; Biener, M; Zielasek, V; Steinrueck, H; Gottfried, M; Biener, J; Hamza, A; B?umer, M

    2008-09-04

    The unique properties of gold especially in low temperature CO oxidation have been ascribed to a combination of various effects. In particular, particle sizes below a few nm and specific particle-support interactions have been shown to play important roles. On the contrary, recent reports revealed that monolithic nanoporous gold (npAu) prepared by leaching a less noble metal, such as Ag, out of the corresponding alloy can also exhibit remarkably high catalytic activity for CO oxidation, even though no support is present. Therefore, it was claimed to be a pure and unsupported gold catalyst. We investigated npAu with respect to its morphology, surface composition and catalytic properties. In particular, we studied the reaction kinetics for low temperature CO oxidation in detail taking mass transport limitation due to the porous structure of the material into account. Our results reveal that Ag, even if removed almost completely from the bulk, segregates to the surface resulting in surface concentrations of up to 10 at%. Our data suggest that this Ag plays a significant role in activation of molecular oxygen. Therefore, npAu should be considered as a bimetallic catalyst rather than a pure Au catalyst.

  12. Faces of Port-au-Prince

    This photo was taken by USGS seismologist Susan Hough two months after the magnitude-7 earthquake struck Port-au-Prince on Jan. 12, 2010. Dr. Hough traveled to Haiti with USGS colleagues Doug Given, Mark Meremonte, and J. Zebulon Maharrey to install seismometers, which monitor the earth's movement a...

  13. Trimetallic Ag@AuPt Neapolitan nanoparticles

    NASA Astrophysics Data System (ADS)

    Song, Yang; Chen, Shaowei

    2013-07-01

    Trimetallic Ag@AuPt Neapolitan nanoparticles were prepared by two sequential galvanic exchange reactions of 1-hexanethiolate-capped silver nanoparticles (AgC6, 5.70 +/- 0.82 nm in diameter) with gold(i)-thiomalic acid (AuITMA) and platinum(ii)-hexanethiolate (PtIIC6) complexes. The first reaction was carried out at the air-water interface by the Langmuir method where the AgC6 nanoparticles formed a compact monolayer and water-soluble AuITMA was injected into the water subphase; the nanoparticles were then deposited onto a substrate surface in the up-stroke fashion and immersed into an acetone solution of PtIIC6. As both reactions were confined to an interface, the Au and Pt elements were situated on two opposite poles of the original Ag nanoparticles. The tripatchy structure was clearly manifested in elemental mapping of the nanoparticles, and consistent with the damping and red-shift of the nanoparticle surface plasmon resonance. Further characterizations by X-ray photoelectron spectroscopy showed that the reactions were mostly confined to the top layers of the Ag metal cores, and contact angle and infrared spectroscopic measurements confirmed the incorporation and segregated distribution of the organic capping ligands on the nanoparticle surface.

  14. Probing the buried C60/Au(111) interface with atoms

    NASA Astrophysics Data System (ADS)

    Tang, Lin; Xie, Yangchun; Guo, Quanmin; University of Birmingham Collaboration

    2014-03-01

    To characterize the C60/Au(111) interface, we send Au atoms ``diving'' through the C60 layer and observe their behavior at the interface. Our observations show that the interfacial diffusion of gold atoms and the nucleation of small Au islands at the interface are strongly dependent on the local C60-Au(111) bonding which varies from one domain to another. The contrast-disordered domain consisting of a large fraction of molecules bonded to Au vacancies has a special structure at the interface allowing Au atoms to be inserted beneath the bright-looking molecules while the dim molecules present a much stronger resistance to the diffusing Au atoms. This leads to the formation of isolated Au islands with discrete sizes, with the smallest island just about 1 nm across.

  15. La tuberculose cutanée: observation de six cas confirmés au CHU Souro SANOU (CHUSS) de Bobo-Dioulasso (Burkina Faso)

    PubMed Central

    Andonaba, Jean Baptiste; Barro-Traoré, Fatou; Yaméogo, Téné; Diallo, Boukary; Korsaga-Somé, Nina; Traoré, Adama

    2013-01-01

    La localisation cutanée de la maladie tuberculeuse demeure une forme rare et représente seulement 2,1% des localisations. L'objet de cette étude est de rapporter le profil épidémiologique, anatomoclinique et évolutif des cas de tuberculose ganglio-cutanée diagnostiqués dans un CHU au Burkina Faso. La fréquence de la tuberculose cutanée est très faible au CHUSS. Six cas ont été diagnostiqués entre 2004 et 2010, soit une fréquence de un cas par an. La durée d’évolution des cas allait de deux jusqu’à dix ans avant leur diagnostic. Les lésions observées étaient: trois scrofulodermes, trois gommes, une tuberculose testiculaire associée à un mal de Pott, un cas de polyadénopathies et des cicatrices atropho-rétractiles dans la plupart des cas. Sur le plan anatomopathologique, des granulomes tuberculoïdes ont été mis en évidence dans tous les cas avec une forte réaction tuberculinique à l'IDR. Sous antituberculeux pendant six mois, l’évolution a été bonne dans tous les cas mais au prix de séquelles cutanées cicatricielles inesthétiques. Son ampleur reste peut-être encore méconnue. Le renforcement du plateau technique du CHU et une bonne collaboration interdisciplinaire contribuerait à un meilleur diagnostic et prise en charge de cette affection. PMID:24648863

  16. Characterization of Au and Bimetallic PtAu Nanoparticles on PDDA-Graphene Sheets as Electrocatalysts for Formic Acid Oxidation

    NASA Astrophysics Data System (ADS)

    Yung, Tung-Yuan; Liu, Ting-Yu; Huang, Li-Ying; Wang, Kuan-Syun; Tzou, Huei-Ming; Chen, Po-Tuan; Chao, Chi-Yang; Liu, Ling-Kang

    2015-09-01

    Nanocomposite materials of the Au nanoparticles (Au/PDDA-G) and the bimetallic PtAu nanoparticles on poly-(diallyldimethylammonium chloride) (PDDA)-modified graphene sheets (PtAu/PDDA-G) were prepared with hydrothermal method at 90 °C for 24 h. The composite materials Au/PDDA-G and PtAu/PDDA-G were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) for exploring the structural characterization for the electrochemical catalysis. According to TEM results, the diameter of Au and bimetallic PtAu nanoparticles is about 20-50 and 5-10 nm, respectively. X-ray diffraction (XRD) results indicate that both of PtAu and Au nanoparticles exhibit the crystalline plane of (111), (200), (210), and (311). Furthermore, XRD data also show the 2°-3° difference between pristine graphene sheets and the PDDA-modified graphene sheets. For the catalytic activity tests of Au/PDDA-G and PtAu/PDDA-G, the mixture of 0.5 M aqueous H2SO4 and 0.5 M aqueous formic acid was used as model to evaluate the electrochemical characterizations. The catalytic activities of the novel bimetallic PtAu/graphene electrocatalyst would be anticipated to be superior to the previous electrocatalyst of the cubic Pt/graphene.

  17. Systematics of Global Observables in Cu+Cu and Au+Au Collisions at RHIC Energies

    SciTech Connect

    Nouicer, Rachid

    2006-07-11

    Charged particles produced in Cu+Cu collisions at {radical}(s{sub NN}) = 200 and 62.4 GeV have been measured in the PHOBOS experiment at RHIC. The comparison of the results for Cu+Cu and Au+Au for the most central collisions at the same energy reveals that the particle density per nucleon participant pair and the extended longitudinal scaling behavior are similar in both systems. This implies that for the most central events in symmetric nucleus-nucleus collisions the particle density per nucleon participant pair does not depend on the size of the two colliding nuclei but only on the collision energy. Also the extended longitudinal scaling seems independent of the colliding energy and species for central collisions. In addition, there is an overall factorization of dNch/d{eta} shapes as a function of collision centraliry between Au+Au and Cu+Cu collisions at the same energy.

  18. Charged-Particle Pseudorapidity Density Distributions from Au+Au Collisions at

    SciTech Connect

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.

    2001-09-03

    The charged-particle pseudorapidity density dN{sub ch}/d{eta} has been measured for Au+Au collisions at s{sub NN}=130 GeV at RHIC, using the PHOBOS apparatus. The total number of charged particles produced for the 3% most-central Au+Au collisions for |{eta}|{<=}5.4 is found to be 4200{+-}470 . The evolution of dN{sub ch}/d{eta} with centrality is discussed, and compared to model calculations and to data from proton-induced collisions. The data show an enhancement in charged-particle production at midrapidity, while in the fragmentation regions, the results are consistent with expectations from pp and pA scattering.

  19. Photoionization of Au+ ions and developments in the synthesis of the metallofullerene Au@C60

    NASA Astrophysics Data System (ADS)

    Bogolub, Kyren; Müller, Alfred; Schippers, Stefan; Hellhund, Jonas; Borovik, Alexander; Kilcoyne, A. L. David; Aguilar, Alex; Mueller, Allison; Johnson, Andrea; Macaluso, David

    2014-05-01

    Single photoionization of Au+ ions was investigated via the merged-beams technique at AMO Beamline 10.0.1 of the Advanced Light Source at Lawrence Berkeley National Laboratory. The relative single photoionization yield was measured as a function of photon energy in the 45 eV to 120 eV energy range. These measurements were made in preparation for future photoionization studies of the endohedral metallofullerene Au@C60, the production of which was also investigated. In proof-of-principle measurements a mass-resolved beam of Au@C60+ was produced with a primary ion beam current in the single picoamp range without optimization of the ion source or synthesis parameters. Plans are presented for improved metallofullere production yield to be used in photoionization measurements of the endohedral fullerene ions in conjunction with the continuing study of pure Au.

  20. Charge-dependent azimuthal correlations from AuAu to UU collisions

    NASA Astrophysics Data System (ADS)

    Bloczynski, John; Huang, Xu-Guang; Zhang, Xilin; Liao, Jinfeng

    2015-07-01

    We study the charge-dependent azimuthal correlations in relativistic heavy ion collisions, as motivated by the search for the Chiral Magnetic Effect (CME) and the investigation of related background contributions. In particular we aim to understand how these correlations induced by various proposed effects evolve from collisions with AuAu system to that with UU system. To do that, we quantify the generation of magnetic field in UU collisions at RHIC energy and its azimuthal correlation with the matter geometry using event-by-event simulations. Taking the experimental data for charge-dependent azimuthal correlations from AuAu collisions and extrapolating to UU with reasonable assumptions, we examine the resulting correlations to be expected in UU collisions and compare them with recent STAR measurements. Based on such analysis we discuss the viability for explaining the data with a combination of the CME-like and flow-induced contributions.

  1. Atomic configurations of Au-induced nanowires on Ge(001) stabilized by higher Au coverages

    NASA Astrophysics Data System (ADS)

    Seino, K.; Bechstedt, F.

    2016-03-01

    Based on density functional calculations with different exchange-correlation functionals we propose three new atomic structures for gold-induced nanowires on Ge(001) surfaces for Au coverages higher than one monolayer. We start the investigations from the original and a modified giant missing row (GMR) structure, the Au-trimer stabilized Ge ridge model. We replace successively Ge atoms at the wire ridge or facets by Au ones. Comparing the relative formation energies the new models are shown to be energetically more favorable than the GMR model proposed previously for lower coverages. Indeed, additional Au atoms at the wire surface stabilize novel geometries. The new models are able to explain several features of the nanowire structure observed by scanning tunneling microscopy and the electronic states found experimentally by angle-resolved photoemission spectroscopy.

  2. Directed Flow of Charged Kaons in Au+Au Collisions from the BES Program at RHIC

    NASA Astrophysics Data System (ADS)

    Pandit, Yadav; STAR Collaboration

    2015-08-01

    We report the measurement of the directed flow (v1) for charged kaons in Au+Au collisions at =7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV as a function of rapidity and compare these results for pions, protons and antiprotons. These new kaon results may help to constrain the medium properties and collision dynamics including the in-medium kaon potential and baryon number transport in these collisions.

  3. Electrical characterization of Ni/Au/AuGe contacts for quantum dot infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Rana, Devendra Kumar; Srivastav, Vanya; Pal, R.; Yadav, B. S.

    2012-01-01

    Transfer length method (TLM) structures were fabricated to characterize the Ni/Au/AuGe-n +-GaAs contacts for quantum dot infrared photodetector (QDIP). Low specific contact resistance of the order of 10 -5 Ω cm 2 indicates formation of a good Ohmic contact. The current-voltage measurements show that current transport is linear with no significant interfacial modification due to alloying of the contact metal. Low contact resistance makes this scheme suitable for the fabrication of heterostructure QDIP devices.

  4. Photoinduced drug release from thermosensitive AuNPs-liposome using a AuNPs-switch.

    PubMed

    An, Xueqin; Zhang, Fan; Zhu, Yinyan; Shen, Weiguo

    2010-10-14

    A thermosensitive liposome with embedded AuNPs in a bilayer was prepared using supercritical CO(2). The AuNPs-liposome can absorb a certain wavelength light, convert optical energy into heat, induce phase transition, and release drug. The results show that drug release from the liposome is due to the photothermic effects inducing phase transition of the liposome rather than destruction of the liposome structure. PMID:20820547

  5. Azimuthal anisotropy of ϕ meson in U+U and Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Bairathi, Vipul

    2016-01-01

    The measurements of the azimuthal anisotropy of φ meson in the U+U and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) are reported. The centrality dependence of the Fourier coefficients v2, v3, v4 and v5 is presented for φ meson at midrapidity (|ƞ| < 1.0), in U+U and Au+Au collisions at -√8NN = 193 and 200 GeV, respectively. The ƞ-sub event plane method is used with a n gap of 0.1 to suppress the non-flow effects. A strong centrality dependence is observed for the φ meson elliptic flow (v2), whereas no clear centrality dependence is observed for v3, v4 and v5. Ratios of the Fourier coefficients, v3/v2 and v4/v22 as a function of transverse momentum (pT) are also presented. A systematic comparison of the Fourier coefficients for the two systems U+U and Au+Au is discussed.

  6. Identified hadrons and jet chemistry for p+p and Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Xu, Yichun; STAR Collaboration

    2010-09-01

    The study of hadron spectra at high pT in p+p collisions provides a good test of perturbative quantum chromo-dynamic calculations (pQCD) and a baseline for measurements of nuclear modification factors in Au+Au collisions. Using events triggered with electro-magnetic calorimetery, identified charged hadron transverse momentum (pT) spectra are measured up to 15 GeV/c at mid-rapidity (|y| < 0.5) and neutral kaon pT spectra up to 12 GeV/c in p+p collisions at \\sqrt{s_{NN}} = 200 GeV in the STAR experiment (Ackermann K H et al 2003 Nucl. Instrum. Methods A 499 624. The particle ratios of p/?+, \\overline{p}/\\pi ^{-} and K, 0/? in p+p collisions are shown and compared with next-to-leading-order pQCD calculations. In central Au+Au collisions, we report nuclear modification factors (RAA) for pion, kaon, proton and ?, and discuss several model calculations: color-charge dependence of jet quenching and jet conversion. Finally, the centrality dependence of RAA at high pT (> 5.5 GeV/c) for kaons is compared with that of pions in Au+Au collisions at 200 GeV.

  7. Magnetism of Au Nanoparticles on Sulfolubus Acidocaldarius S-Layer

    NASA Astrophysics Data System (ADS)

    Bartolome, Juan; Bartolome, F.; Garcia, L. M.; Figueroa, A. I.; Herrmannsdoerfer, T.; Skrotzki, R.; Schoenemann, R.; Wosnitza, J.; Selenska-Pobell, S.; Geissler, A.; Reitz, T.; Wilhelm, F.; Rogalev, A.

    2011-03-01

    Au nanoparticles (NP) with diameters of a few nm have been synthesized on a protein S-layer of Sulfolobus Acidocaldarius bacteria. SQUID magnetization (1.8 K T 300 Kand 0 B 7 T) showssuperparamagneticbehavioratlow - T . ItsoriginlaysattheAuNP ' s , ashasbeenprovenbyAuL 2,3- edgeXMCDspectroscopy , performedintherange 2.2 T 20 KanduptoB app = 17 T . XMCDanalysisyieldsatotalmagneticmomentperAuatom μAu = 0.050 (1) μB , aparticleaveragemomentm part = 2.3 μB , Auorbitaltospinmomentratioofm L / m S = 0.29 Curie and - like superparamagnetism. Au - S bonds are detected by S K - edge XAS measurements. Besides , EXAFS at the Au L 3 -edge shows that the Au NP internal structure is fcc, and Au-S bonds are located at the particle surface. An increase of the hole charge carrier density in the Au 5d band due to electron transfer with the S-layer explains the Au magnetism. The observed magnetic moment per Au atom is 25 times larger than those previously found by XMCD in Au-thiol capped NPs.

  8. Monodisperse AuCuSn trimetallic nanocube catalysts.

    PubMed

    Patra, Biplab K; Khilari, Santimoy; Pradhan, Debabrata; Pradhan, Narayan

    2016-01-28

    Monodisperse trimetallic AuCuSn nanocubes are reported where Sn and Cu are inserted into the crystal lattice following co-precipitation protocols along with Au. These trimetallics are explored further towards catalytic hydrazine electrooxidation and their enhanced catalytic activity compared with their bimetallic counterpart AuCu is reported. PMID:26659602

  9. Evidence of Significant Covalent Bonding in Au(CN)2-

    SciTech Connect

    Wang, Xue B.; wang, Yi-Lei; Yang, Jie; Xing, Xiaopeng; Li, Jun; Wang, Lai S.

    2009-11-18

    There have been intense recent interests in the homogeneous catalytic chemistry of Au(I) complexes.1 Among the Au(I) molecules, the Au(CN)2- ion is the most stable and has been widely used in gold extraction back to ancient times. Although AuCN in the condensed phase has been studied, including solution phase vibrational spectroscopy2 and crystal structures,3 the free AuCN molecule has been studied only very recently by microwave spectroscopy.4 The important Au(CN)2- complex has not been observed and studied in the gas phase. Because of the relativistic effects,5 Au-containing molecules exhibit distinctly different properties among the coinage elements. To elucidate the nature of the Au-ligand binding, high-level ab initio calculations are needed due to the complicated electron correlation and relativistic effects.6-8 The structure and bonding of the AuCN molecule were first examined computationally by Frenking and co-workers.7 Recent high-precision calculations by Pyykkö and co-workers suggest multiple-bond characters between Au-C in AuCN because the Au-C bond length is only slightly longer than the sum of the triple bond covalent radii.

  10. Controlling Au Nanorod Dispersion in Thin Film Polymer Blends

    NASA Astrophysics Data System (ADS)

    Hore, Michael J. A.; Composto, Russell J.

    2012-02-01

    Dispersion of Au nanorods (Au NRs) in polymer thin films is studied using a combination of experimental and theoretical techniques. Here, we incorporate small volume fractions of polystyrene-functionalized Au NRs (φrod 0.05) into polystyrene (PS) thin films. By controlling the ratio of the brush length (N) to that of the matrix polymers (P), we can selectively obtain dispersed or aggregated Au NR structures in the PS-Au(N):PS(P) films. A dispersion map of these structures allows one to choose N and P to obtain either uniformly dispersed Au NRs or aggregates of closely packed, side-by-side aligned Au NRs. Furthermore, by blending poly(2,6-dimethyl-p-phenylene oxide) (PPO) into the PS films, we demonstrate that the Au nanorod morphology can be further tuned by reducing depletion-attraction forces and promoting miscibility of the Au NRs. These predictable structures ultimately give rise to tunable optical absorption in the films resulting from surface plasmon resonance coupling between the Au NRs. Finally, self-consistent field theoretic (SCFT) calculations for both the PS-Au(N):PS(P) and PS-Au(N):PS(P):PPO systems provide insight into the PS brush structure, and allow us to interpret morphology and optical property results in terms of wet and dry PS brush states.

  11. A measurement of Y suppression in Au-Au collisions at 200 GeV in the PHENIX experiment

    NASA Astrophysics Data System (ADS)

    Whitaker, Shawn Douglas

    Upsilon production was measured in Au-Au collisions using the PHENIX detector at RHIC using the data taken during the 2010 data taking operations. It was found that Upsilon production was suppressed relative to proton-proton collisions.

  12. Jet-Hadron Correlations in √sNN =200 GeV p +p and Central Au +Au Collisions

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L., Jr.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-03-01

    Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au +Au and p +p collisions at √sNN =200 GeV in STAR are presented. The trigger jet population in Au +Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au +Au and p +p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au +Au collisions compared to p +p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

  13. Identified particle distributions in pp and Au+Au collisions atsqrt sNN=200 GeV

    SciTech Connect

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M; Arkhipkin, D.; Averichev, G.S.; Badyal,S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele,S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj,S.; Bhaskar, P.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar,A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez,M.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Ganti, M.S.; Gutierrez, T.D.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Cronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris,J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang,S.L.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.S.; Kopytine,S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger,K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; et al.

    2003-10-06

    Transverse mass and rapidity distributions for charged pions, charged kaons, protons and antiprotons are reported for {radical}sNN = 200 GeV pp and Au+Au collisions at RHIC. The transverse mass distributions are rapidity independent within |y| < 0.5, consistent with a boost-invariant system in this rapidity interval. Spectral shapes and relative particle yields are similar in pp and peripheral Au+Au collisions and change smoothly to central Au+Au collisions. No centrality dependence was observed in the kaon and antiproton production rates relative to the pion production rate from medium-central to central collisions. Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and relatively long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

  14. Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S.

    PubMed

    Tian, Zhimei; Cheng, Longjiu

    2016-01-14

    Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the "divide and protect" concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S(2)1P(6) configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters. PMID:26530472

  15. From the Ternary Eu(Au/In)2 and EuAu4(Au/In)2 with Remarkable Au/In Distributions to a New Structure Type: The Gold-Rich Eu5Au16(Au/In)6 Structure.

    PubMed

    Steinberg, Simon; Card, Nathan; Mudring, Anja-Verena

    2015-09-01

    The ternary Eu(Au/In)2 (EuAu(0.46)In(1.54(2))) (I), EuAu4(Au/In)2 (EuAu(4+x)In(2-x) with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au(17.29)In(4.71(3))) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-type (tI14; I4/mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au(17.29)In(4.71(3))) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu2-"EuAu4In2". The site preferences of the disordered Au/In positions in II were investigated for different hypothetical "EuAu4(Au/In)2" models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au-In contacts. A chemical bonding analysis on two "EuAu5In" and "EuAu4In2" models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems. PMID:26270622

  16. Watchfully checking rapport with the Primary Child Health Care nurses - a theoretical model from the perspective of parents of foreign origin

    PubMed Central

    2010-01-01

    Background Worldwide, multicultural interaction within health care seems to be challenging and problematic. This is also true among Primary Child Health Care nurses (PCHC nurses) in the Swedish Primary Child Health Care services (PCHC services). Therefore, there was a need to investigate the parents' perspective in-depth. Aim The aim of the study was to construct a theoretical model that could promote further understanding of the variety of experiences of parents of foreign origin regarding their interaction with the PCHC nurses at PCHC services. Method The study used Grounded Theory Methodology. Twenty-one parents of foreign origin in contact with PCHC servicies were interviewed. Results In our study parents were watchfully checking rapport, i.e. if they could perceive sympathy and understanding from the PCHC nurses. This was done by checking the nurse's demeanour and signs of judgement. From these interviews we created a theoretical model illustrating the interactive process between parents and PCHC nurses. Conclusion We found it to be of utmost importance for parents to be certain that it was possible to establish rapport with the PCHC nurse. If not, disruptions in the child's attendance at PCHC services could result. PCHC nurses can use the theoretical model resulting from this study as a basis for understanding parents, avoiding a demeanour and judgements that may cause misunderstandings thus promoting high-quality interaction in PCHC services. PMID:20646287

  17. Spectra and elliptic flow for Λ, Ξ, and Ω in 200 A GeV Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Zhu, Xiangrong; Song, Huichao

    2016-01-01

    Using VISHNU hybrid model, we calculate the pT-spectra and elliptic flow of Λ, Ξ, and Ω in 200 A GeV Au+Au collisions. Comparisons with the STAR measurements show that the model generally describes these soft hadron data. We also briefly study and discuss the mass ordering of elliptic flow among π, K, p, Λ, Ξ, and Ω in minimum bias Au+Au collisions.

  18. Centrality dependence of direct photon production in (square root)S(NN) = 200 GeV Au + Au collisions.

    PubMed

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Veszprémi, V; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

    2005-06-17

    The first measurement of direct photons in Au + Au collisions at (square root)S(NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au + Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities. PMID:16090462

  19. Centrality Dependence of Direct Photon Production in {radical}(S{sub NN})=200 GeV Au+Au Collisions

    SciTech Connect

    Adler, S.S.; Aidala, C.; Aronson, S.H.; Chujo, T.; David, G.; Desmond, E.J.; Ewell, L.; Franz, A.; Guryn, W.; Haggerty, J.S.; Harvey, M.; Johnson, B.M.; Kistenev, E.; Kroon, P.J.; Makdisi, Y.I.; Mioduszewski, S.; Mitchell, J.T.; Morrison, D.P.; O'Brien, E.; Pinkenburg, C.

    2005-06-17

    The first measurement of direct photons in Au+Au collisions at {radical}(s{sub NN})=200 GeV is presented. The direct photon signal is extracted as a function of the Au+Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities.

  20. AU-FREDI - AUTONOMOUS FREQUENCY DOMAIN IDENTIFICATION

    NASA Technical Reports Server (NTRS)

    Yam, Y.

    1994-01-01

    The Autonomous Frequency Domain Identification program, AU-FREDI, is a system of methods, algorithms and software that was developed for the identification of structural dynamic parameters and system transfer function characterization for control of large space platforms and flexible spacecraft. It was validated in the CALTECH/Jet Propulsion Laboratory's Large Spacecraft Control Laboratory. Due to the unique characteristics of this laboratory environment, and the environment-specific nature of many of the software's routines, AU-FREDI should be considered to be a collection of routines which can be modified and reassembled to suit system identification and control experiments on large flexible structures. The AU-FREDI software was originally designed to command plant excitation and handle subsequent input/output data transfer, and to conduct system identification based on the I/O data. Key features of the AU-FREDI methodology are as follows: 1. AU-FREDI has on-line digital filter design to support on-orbit optimal input design and data composition. 2. Data composition of experimental data in overlapping frequency bands overcomes finite actuator power constraints. 3. Recursive least squares sine-dwell estimation accurately handles digitized sinusoids and low frequency modes. 4. The system also includes automated estimation of model order using a product moment matrix. 5. A sample-data transfer function parametrization supports digital control design. 6. Minimum variance estimation is assured with a curve fitting algorithm with iterative reweighting. 7. Robust root solvers accurately factorize high order polynomials to determine frequency and damping estimates. 8. Output error characterization of model additive uncertainty supports robustness analysis. The research objectives associated with AU-FREDI were particularly useful in focusing the identification methodology for realistic on-orbit testing conditions. Rather than estimating the entire structure, as is typically done in ground structural testing, AU-FREDI identifies only the key transfer function parameters and uncertainty bounds that are necessary for on-line design and tuning of robust controllers. AU-FREDI's system identification algorithms are independent of the JPL-LSCL environment, and can easily be extracted and modified for use with input/output data files. The basic approach of AU-FREDI's system identification algorithms is to non-parametrically identify the sampled data in the frequency domain using either stochastic or sine-dwell input, and then to obtain a parametric model of the transfer function by curve-fitting techniques. A cross-spectral analysis of the output error is used to determine the additive uncertainty in the estimated transfer function. The nominal transfer function estimate and the estimate of the associated additive uncertainty can be used for robust control analysis and design. AU-FREDI's I/O data transfer routines are tailored to the environment of the CALTECH/ JPL-LSCL which included a special operating system to interface with the testbed. Input commands for a particular experiment (wideband, narrowband, or sine-dwell) were computed on-line and then issued to respective actuators by the operating system. The operating system also took measurements through displacement sensors and passed them back to the software for storage and off-line processing. In order to make use of AU-FREDI's I/O data transfer routines, a user would need to provide an operating system capable of overseeing such functions between the software and the experimental setup at hand. The program documentation contains information designed to support users in either providing such an operating system or modifying the system identification algorithms for use with input/output data files. It provides a history of the theoretical, algorithmic and software development efforts including operating system requirements and listings of some of the various special purpose subroutines which were developed and optimized for Lahey FORTRAN compilers on IBM PC-AT computers before the subroutines were integrated into the system software. Potential purchasers are encouraged to purchase and review the documentation before purchasing the AU-FREDI software. AU-FREDI is distributed in DEC VAX BACKUP format on a 1600 BPI 9-track magnetic tape (standard media) or a TK50 tape cartridge. AU-FREDI was developed in 1989 and is a copyrighted work with all copyright vested in NASA.

  1. Influence of Au and TiO2 structures on hydrogen dissociation over TiO2/Au(100)

    NASA Astrophysics Data System (ADS)

    Nakamura, I.; Mantoku, H.; Furukawa, T.; Takahashi, A.; Fujitani, T.

    2012-11-01

    We performed H2-D2 exchange reactions over TiOx/Au(100) and compared the observed reaction kinetics with those reported for TiOx/Au(111) in order to clarify the influence of the Au and TiO2 structures on dissociation of H2 molecules. Low energy electron diffraction observations showed that the TiO2 produced on Au(100) was disordered, in contrast to the comparatively ordered TiO2 structure formed on Au(111). The activation energies and the turnover frequencies for HD formation over TiO2/Au(100) agreed well with those for TiO2/Au(111), clearly indicating that the hydrogen dissociation sites created over TiO2/Au(100) were the perimeter interface between stoichiometric TiO2 and Au, as was previously concluded for TiO2/Au(111). We concluded that the creation of active sites for hydrogen dissociation was independent of the Au and TiO2 structures consisting perimeter interface, and that local bonds that formed between Au and O atoms of stoichiometric TiO2 were essential for the creation of active sites.

  2. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, T.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, W.; Li, Z. M.; Li, Y.; Li, C.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Ma, R.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, Z.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, F.; Wang, H.; Wang, G.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, H.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, N.; Yang, S.; Yang, Y.; Yang, Q.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Y.; Zhang, Z.; Zhang, J. B.; Zhang, J.; Zhang, X. P.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.

    2015-12-01

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  3. From the ternary Eu(Au/In)2 and EuAu4(Au/In)2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu5Au16(Au/In)6 structure

    DOE PAGESBeta

    Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

    2015-08-13

    The ternary Eu(Au/In)2 (EuAu0.46In1.54(2)) (I), EuAu4(Au/In)2 (EuAu4+xIn2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-type (tI14; I4/mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squaredmore » Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu2–“EuAu4In2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu4(Au/In)2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu5In” and “EuAu4In2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

  4. Cooperative assembly of magic number C60-Au complexes.

    PubMed

    Xie, Yang-Chun; Tang, Lin; Guo, Quanmin

    2013-11-01

    We report the assembly of magic number (C60)m-(Au)n complexes on the Au(111) surface. These complexes have a unique structure consisting of a single atomic layer Au island wrapped by a self-selected number (seven, ten, or twelve) of C(60) molecules. The smallest structure consisting of 7 C60 molecules and 19 Au atoms, stable up to 400 K, has a preferred orientation on the surface. We propose a globalized metal-organic coordination mechanism for the stability of the (C(60))(m)-(Au)n complexes. PMID:24237540

  5. Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers

    SciTech Connect

    Li, Bin; Kim, Sung-Jin; Miller, Gordon J.; and Corbett, John D.

    2009-10-29

    The new phase K{sub 12}Au{sub 21}Sn{sub 4} has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) {angstrom}, V = 1901.3(7) {angstrom}{sup 3}, and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au{sub 20}) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn{sub 4}). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K{sub 3}Au{sub 5}In and Rb{sub 2}Au{sub 3}Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22).

  6. Collision-spike sputtering of Au nanoparticles

    SciTech Connect

    Sandoval, Luis; Urbassek, Herbert M.

    2015-08-06

    Ion irradiation of nanoparticles leads to enhanced sputter yields if the nanoparticle size is of the order of the ion penetration depth. While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation. For this specific case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target. Only around 31% of the impact energy remains in the nanoparticles after impact; the remainder is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80% of that of free nanoparticles due to the suppression of forward sputtering.

  7. Collision-spike sputtering of Au nanoparticles

    DOE PAGESBeta

    Sandoval, Luis; Urbassek, Herbert M.

    2015-08-06

    Ion irradiation of nanoparticles leads to enhanced sputter yields if the nanoparticle size is of the order of the ion penetration depth. While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation. For this specific case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target. Only around 31% of the impact energy remains in the nanoparticles after impact; the remaindermore » is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80% of that of free nanoparticles due to the suppression of forward sputtering.« less

  8. OPERATION OF THE RHIC AU ION SOURCE.

    SciTech Connect

    STESKI,D.B.; ALESSI,J.; BENJAMIN,J.; CARLSON,C.; MANNI,M.; THIEBERGER,P.; WIPLICH,M.

    2001-09-02

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is beginning its second year of operation. A cesium sputter ion source injecting into a tandem Van de Graaff provides the gold ions for RHIC. The ion source is operated in the pulsed beam mode and produces a 500{micro}sec long pulse of Au{sup -} with a peak intensity of 290pA at the entrance of the tandem. After acceleration in the tandem and post stripping, this results in a beam of Au{sup +32} with an intensity of 80e{micro}A and an energy of 182MeV. Over the last several years, a series of improvements have been made to increase the intensity of the pulsed beam from the ion source. Details of the source performance and improvements will be presented. In addition, an effort is under way to provide other beam species for RHIC collisions.

  9. Bactericidal mechanisms of Au@TNBs under visible light irradiation.

    PubMed

    Guo, Lingqiao; Shan, Chao; Liang, Jialiang; Ni, Jinren; Tong, Meiping

    2015-04-01

    Au@TNBs nanocomposites were synthesized by depositing Au nanoparticles onto the surfaces of TiO2 nanobelts (TNBs). The disinfection activities of Au@TNBs on model cell type, Gram-negative Escherichia coli (E. coli), were examined under visible light irradiation conditions. Au@TNBs exhibited stronger bactericidal properties toward E. coli than those of TNBs and Au NPs under visible light irradiation. The bactericidal mechanisms of Au@TNBs under light conditions were explored, specifically, the specific active species controlling the inactivation of bacteria were determined. Active species (H2O2, diffusing ∙OH, ∙O2-, 1O2, and e-) generated by Au@TNBs were found to play important roles on the inactivation of bacteria. Moreover, the concentrations of H2O2, ·OH, ·O2-, and 1O2 generated in the antimicrobial system were estimated. Without the presence of active species, the direct contact of Au@TNBs with bacterial cells was found to have no bactericidal effect. The reusability of Au@TNBs were also determined. Au@TNBs exhibited strong antibacterial activity toward E. coli even in five consecutively reused cycles. This study indicated that the fabricated Au@TNBs could be potentially utilized to inactivate bacteria in water. PMID:25656356

  10. Fahrzeug-Außengeräusch

    NASA Astrophysics Data System (ADS)

    Genuit, Klaus

    Wirtschaftliches Wachstum ist mit steigenden Anforderungen an Mobilität und Transport verknüpft. Zukunftsorientierter Fortschritt muss hierbei die Wirkungen von Verkehrsgeräuschen auf Mensch und Umwelt berücksichtigen, um eine hohe Lebensqualität sicherstellen zu können. Mehr als die Hälfte der Bevölkerung in der EU fühlt sich durch Verkehrslärm belästigt oder befürchtet direkte Auswirkungen auf Gesundheit und Wohlbefinden. Nach einer repräsentativen Umfrage des Umweltbundesamtes fühlen sich durch Straßenverkehrslärm 20 % der Bevölkerung stark oder wesentlich belästigt (UBA 2008). Daher ist das "Fahrzeug-Außengeräusch“ Gegenstand zahlreicher Forschungsprojekte zu Themen wie Identifikation wesentlicher Geräuschquellen, Zusammenhang zwischen Verkehrsgeräusch und Belästigung, medizinische Folgen aufgrund chronischer Lärmexposition, Geräuschqualität, Entwicklung neuer Methoden und Technologien zur Fahrzeug-Außengeräuschmessung und das Fahrzeug-Außengeräusch als wesentliches Produktattribut, das aktiver Gestaltung bedarf.

  11. Electric Field Induced Surface Modification of Au

    SciTech Connect

    Erchak, A.A.; Franklin, G.F.; Houston, J.E.; Mayer, T.M.; Michalske, T.A.

    1999-02-15

    We discuss the role of localized high electric fields in the modification of Au surfaces with a W probe using the Interfacial Force Microscope. Upon bringing a probe close to a Au surface, we measure both the interfacial force and the field emission current as a function of separation with a constant potential of 100 V between tip and sample. The current initially increases exponentially as the separation decreases. However, at a distance of less than {approximately} 500{angstrom} the current rises sharply as the surface begins to distort and rapidly close the gap. Retraction of the tip before contact is made reveals the formation of a mound on the surface. We propose a simple model, in which the localized high electric field under the tip assists the production of mobile Au adatoms by detachment from surface steps, and a radial field gradient causes a net flux of atoms toward the tip by surface diffusion. These processes give rise to an unstable surface deformation which, if left unchecked, results in a destructive mechanical contact. We discuss our findings with respect to earlier work using voltage pulses in the STM as a means of nanofabrication.

  12. Enhance Your Press Rapport.

    ERIC Educational Resources Information Center

    Criscuolo, Nicholas P.

    1982-01-01

    Offers school administrators eight suggestions for increasing the amount and quality of newspaper coverage, including writing a regular newspaper column, discussing educational coverage with the managing editor, inviting education reporters to observe school activities, using the district staff's writing talents, and holding news conferences.…

  13. Analysis of the residual linewidth in electron-paramagnetic resonance of AuEr and AuYb

    NASA Astrophysics Data System (ADS)

    Spalden, Y. von; Baberschke, K.

    1981-04-01

    For single crystals of AuEr and polycrystalline AuYb the residual EPR linewidth due to inhomogeneous broadening is analyzed. Angular dependent experiments show uniquely that the main contribution is due to internal strain rather than to dipolar interaction. The independent experiments for AuEr and AuYb yield a consistent set of parameters but show a dipolar contribution two to three times smaller than calculated. An explanation for this is given. The very precise determination of Hres yields |Δg | = |ρJ1| < 0.005 for AuEr, a vanishing g-shift.

  14. Thermal stability of sputtered intermetallic Al-Au coatings

    SciTech Connect

    Moser, M.; Mayrhofer, P. H.; Ross, I. M.; Rainforth, W. M.

    2007-09-15

    Recently, the authors have shown that single-phase Al{sub 2}Au coatings, prepared by unbalanced magnetron sputtering, exhibit a dense columnar structure and highest hardness and indentation moduli of 8 and 144 GPa, respectively, within the Al-Au films investigated. This study focuses on the thermal stability of Al{sub 2}Au with respect to films containing more Al and Au having Al/Au at. % ratios of 4.32 and 1.85, respectively. Single-phase Al{sub 2}Au has the highest onset temperature for recovery of 475 deg. C and recrystallization of 575 deg. C. Upon annealing Au- and Al-rich films, their stresses deviate from the linear thermoelastic behavior at temperatures (T) above 200 and 450 deg. C, respectively, due to pores and metallic phases present. Metastable Au within the as-deposited Au-rich film is consumed by the growing intermetallic AlAu and AlAu{sub 2} phases at T{>=}450 deg. C, which themselves melt at {approx}625 deg. C. Due to nanometer scale segregations of Al, encapsulated by Al{sub 2}Au in Al-rich coatings, their melting point is reduced by {approx}85 deg. C to 575 deg. C. Dynamic thermal analyses up to 1100 deg. C in synthetic air reveal the single-phase Al{sub 2}Au films with a superior thermal stability and only negligible oxidation. At 750 deg. C, the mass gain is {approx}1.5 mg/cm{sup 2} after 50 h isothermal exposure. Based on the investigations, the authors can conclude that single-phase intermetallic Al{sub 2}Au films have a high potential for oxidation protection of sensitive materials.

  15. Photocatalysis enhancement of Au/BFO nanoparticles using plasmon resonance of Au NPs

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Cai, Zhongyang; Ma, Xueming

    2015-12-01

    BiFeO3 (BFO) nanoparticles was synthesized via sol-gel technique, and successfully loaded with small sizes of gold nanoparticles (Au NPs) by impregnation-reduction method to extremely enhance the BFO photocatalytic activity. The obviously stronger optical absorption of Au/BFO observed from the UV-vis diffuse reflectance spectrum confirmed that the surface plasmon resonance (SPR) effect occured on the surface of Au NPs. And the surface plasmon-induced localized electric field could allow the formation of electron/hole pairs in the near surface region of BFO which can migrate to the surface without undergoing electron/hole (e-/h+) pair recombination. The more electrons and holes formed, the more ·OH will be generated to decompose the CR solution. When the gold loading in Au/BFO nanoparticles is 3.36 wt%, the obtained Au/BFO catalyst exhibits best photocatalytic activity evaluated by photocatalysis degradation of Congo red (CR) solution under the visible light irradiation.

  16. Unwinding Au(+)···Au(+) Bonded Filaments in Ligand-Supported Gold(I) Polymer under Pressure.

    PubMed

    Paliwoda, Damian; Wawrzyniak, Paulina; Katrusiak, Andrzej

    2014-07-01

    The ultimately thin single-strand gold filaments, of Au(+)···Au(+) bonded gold(I) diethyldithiocarbamate polymer, AuEt2DTC, can be transformed depending on pressure and solvate contents. When synthesized in the presence of CH2Cl2, it crystallizes into a tetragonal AuEt2DTC·xCH2Cl2 phase α with ligand-supported and unsupported Au(+)···Au(+) bonded filaments modulated into molecular Au8-pitch helices. Low contents of CH2Cl2 favors the β phase of significantly reduced volume and orthorhombic space group Fddd. The α-AuEt2DTC·xCH2Cl2 crystal exhibits a highly unusual negative-area compressibility, due to the spring-like compression of helices. Above 0.05 GPa, the crystal transforms to phase β, where the Au16-pitch helices partly unwind their turns, which relaxes the tension generated by external pressure between neighboring helices of the opposite handedness. This is a unique observation of atomic-scale helical filaments transformation, which otherwise is a universal process analogous to the helix reversal between DNA forms B and Z, and in macroscopic world it is similar to nonperiodic unwind kinks in grapevine tendrils and telephone cords. Pressure also reduces the differences between the ligand-supported and unsupported Au(+)···Au(+) bonds. PMID:26279531

  17. Electron beam induced evolution in Au, Ag, and interfaced heterogeneous Au/Ag nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Yuzi; Sun, Yugang

    2015-08-01

    A sintering process of nanoparticles made of Ag, Au, and interfaced Ag/Au heterodimers was investigated by in situ transmission electron microscopy at room temperature. Such a process is driven by the illumination of a high-energy electron beam accelerated at 200 kV that promotes atom diffusion in the nanoparticles that are in physical contact. Upon electron illumination, adjacent Au nanoparticles gradually merge together to form a larger particle along with the reduction of the surface area despite the fact that orientated attachment is not observed. According to the detailed analysis of the size change of the particles and the contact area, it was found that the nanoparticle fusion process is significantly different from the well-established thermal diffusion mechanism. In addition to the similar fusion process of Au nanoparticles, Ag nanoparticles undergo apparent sublimation induced by knock on damage because the transferred energy from the electron beam to nanoparticles is higher than the surface binding energy of Ag atoms when the electron scattering angle is larger than 112. The particles with a smaller size diffuse faster. Surface diffusion dominates at the beginning of the fusion process followed by slower lattice diffusion. Electron beam illumination can transform the interfaced Au/Ag dimers to Au@Ag core-shell particles followed by a slow removal of the Ag shells. This process under normal electron beam illumination is a lot faster than the thermally driven process. Both diffusion and sublimation of Ag atoms are dependent on the intensity of the electron beam, i.e., a higher beam intensity is favorable to accelerate both the processes.A sintering process of nanoparticles made of Ag, Au, and interfaced Ag/Au heterodimers was investigated by in situ transmission electron microscopy at room temperature. Such a process is driven by the illumination of a high-energy electron beam accelerated at 200 kV that promotes atom diffusion in the nanoparticles that are in physical contact. Upon electron illumination, adjacent Au nanoparticles gradually merge together to form a larger particle along with the reduction of the surface area despite the fact that orientated attachment is not observed. According to the detailed analysis of the size change of the particles and the contact area, it was found that the nanoparticle fusion process is significantly different from the well-established thermal diffusion mechanism. In addition to the similar fusion process of Au nanoparticles, Ag nanoparticles undergo apparent sublimation induced by knock on damage because the transferred energy from the electron beam to nanoparticles is higher than the surface binding energy of Ag atoms when the electron scattering angle is larger than 112. The particles with a smaller size diffuse faster. Surface diffusion dominates at the beginning of the fusion process followed by slower lattice diffusion. Electron beam illumination can transform the interfaced Au/Ag dimers to Au@Ag core-shell particles followed by a slow removal of the Ag shells. This process under normal electron beam illumination is a lot faster than the thermally driven process. Both diffusion and sublimation of Ag atoms are dependent on the intensity of the electron beam, i.e., a higher beam intensity is favorable to accelerate both the processes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03523f

  18. Diffusion of Au in the Intermetallic Compound Ti3Al

    NASA Astrophysics Data System (ADS)

    Koizumi, Y.; Tanaka, T.; Minamino, Y.

    2009-12-01

    The Au diffusion in the Ti3Al compound was investigated at six compositions from 25 to 35 at. pct Al by using the diffusion couples (Ti- X at. pct Al/Ti- X at. pct Al-2 at. pct Au; X = 25, 27, 29, 31, 32, and 35) at 1273 to 1423 K. The diffusion coefficients of Au in Ti3Al left( {D_{text{Au}}^{{{text{Ti}}3 {text{Al}}}} } right) are relatively close to those of Ti. The {D}_{text{Au}}^{{{text{Ti}}3 {text{Al}}}} {text{s}} slightly increase with Al concentration within the same order of magnitude. The activation energies of Au diffusion, Q_{text{Au}}^{{{text{Ti}}3 {text{Al}}}} {text{s}}, evaluated from the Arrhenius plots were relatively close to those of Ti diffusion, Q_{text{Ti}}^{{{text{Ti}}3 {text{Al}}}} {text{s}}, rather than those of Al diffusion, {Q}_{text{Al}}^{{{text{Ti}}3 {text{Al}}}} {text{s}}; therefore, it was suggested that Au atoms diffuse by the sublattice diffusion mechanism in which Au atoms substitute for Ti sites preferentially in Ti3Al and diffuse by vacancy mechanism on Ti sublattice. The influence of the D019 ordered structure (hcp base) of Ti3Al on diffusion of Au and other elements is discussed by comparing the diffusivities in Ti3Al and α-Ti.

  19. Doping Golden Buckyballs: Cu@Au16- and Cu@Au17- Cluster Anions

    SciTech Connect

    Wang, Leiming; Bulusu, Satya; Zhai, Hua-jin; Zeng, Xiao Cheng; Wang, Lai S.

    2007-04-13

    The discovery of the unique catalytic effects of gold nanoparticles on oxide substrates has stimulated a flurry of research into the structures and properties of free gold nanoclusters, which may hold the key to elucidating the catalytic mechanisms of supported gold clusters. One of the most remarkable results has been the discovery of planar gold cluster anions (Aun_) of up to twelve gold atoms and the 2D to 3D transition for clusters with n larger than 12. Among larger gold clusters, Au20 has been found to be a perfect tetrahedron. A more recent study of the structures of Aun_ cluster anions in the medium size range (n=15–19) has shown that clusters with n=16–18 possess unprecedented empty cage structures. In particular, the Au16_ cluster anion has an interesting tetrahedral structure with an inner diameter of about 5.5 0 and can be compared to the fullerenes (buckyballs). Although Au32 was first suggested to be a “24- carat golden fullerene”, subsequent studies showed that the Au32_ ion is in fact a low-symmetry compact 3D structure. Other larger gold cage clusters have also been proposed computationally, but none has been observed or is expected to be the global minimum. The cage structures of the cluster anions Au16_ and Au17_ have recently been confirmed by electron diffraction and thus they are the first experimentally confirmed and the smallest possible gold cages. The large empty space inside these cage clusters immediately suggested that they can be doped with a foreign atom to produce a new class of endohedral gold cages analogous to endohedral fullerenes.

  20. Electron beam induced evolution in Au, Ag, and interfaced heterogeneous Au/Ag nanoparticles.

    PubMed

    Liu, Yuzi; Sun, Yugang

    2015-08-28

    A sintering process of nanoparticles made of Ag, Au, and interfaced Ag/Au heterodimers was investigated by in situ transmission electron microscopy at room temperature. Such a process is driven by the illumination of a high-energy electron beam accelerated at 200 kV that promotes atom diffusion in the nanoparticles that are in physical contact. Upon electron illumination, adjacent Au nanoparticles gradually merge together to form a larger particle along with the reduction of the surface area despite the fact that orientated attachment is not observed. According to the detailed analysis of the size change of the particles and the contact area, it was found that the nanoparticle fusion process is significantly different from the well-established thermal diffusion mechanism. In addition to the similar fusion process of Au nanoparticles, Ag nanoparticles undergo apparent sublimation induced by knock on damage because the transferred energy from the electron beam to nanoparticles is higher than the surface binding energy of Ag atoms when the electron scattering angle is larger than 112°. The particles with a smaller size diffuse faster. Surface diffusion dominates at the beginning of the fusion process followed by slower lattice diffusion. Electron beam illumination can transform the interfaced Au/Ag dimers to Au@Ag core-shell particles followed by a slow removal of the Ag shells. This process under normal electron beam illumination is a lot faster than the thermally driven process. Both diffusion and sublimation of Ag atoms are dependent on the intensity of the electron beam, i.e., a higher beam intensity is favorable to accelerate both the processes. PMID:26213998

  1. Charged particle multiplicities in ultra-relativistic Au+Au and Cu+Cu collisions.

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; PHOBOS Collaboration; Physics; Massachusetts Inst. of Tech.; BNL

    2006-01-01

    The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5 to 179.5 deg. corresponding to |eta|<5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.

  2. Elliptic Flow in Au+Au Collisions at √sNN = 130 GeV

    NASA Astrophysics Data System (ADS)

    Ackermann, K. H.; Adams, N.; Adler, C.; Ahammed, Z.; Ahmad, S.; Allgower, C.; Amsbaugh, J.; Anderson, M.; Anderssen, E.; Arnesen, H.; Arnold, L.; Averichev, G. S.; Baldwin, A.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Beddo, M.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Bennett, S.; Bercovitz, J.; Berger, J.; Betts, W.; Bichsel, H.; Bieser, F.; Bland, L. C.; Bloomer, M.; Blyth, C. O.; Boehm, J.; Bonner, B. E.; Bonnet, D.; Bossingham, R.; Botlo, M.; Boucham, A.; Bouillo, N.; Bouvier, S.; Bradley, K.; Brady, F. P.; Braithwaite, E. S.; Braithwaite, W.; Brandin, A.; Brown, R. L.; Brugalette, G.; Byrd, C.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carr, L.; Carroll, J.; Castillo, J.; Caylor, B.; Cebra, D.; Chatopadhyay, S.; Chen, M. L.; Chen, W.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Chrin, J.; Christie, W.; Coffin, J. P.; Conin, L.; Consiglio, C.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Danilov, V. I.; Dayton, D.; Demello, M.; Deng, W. S.; Derevschikov, A. A.; Dialinas, M.; Diaz, H.; Deyoung, P. A.; Didenko, L.; Dimassimo, D.; Dioguardi, J.; Dominik, W.; Drancourt, C.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Eggert, T.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Etkin, A.; Fachini, P.; Feliciano, C.; Ferenc, D.; Ferguson, M. I.; Fessler, H.; Finch, E.; Fine, V.; Fisyak, Y.; Flierl, D.; Flores, I.; Foley, K. J.; Fritz, D.; Gagunashvili, N.; Gans, J.; Gazdzicki, M.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Gojak, C.; Grabski, J.; Grachov, O.; Grau, M.; Greiner, D.; Greiner, L.; Grigoriev, V.; Grosnick, D.; Gross, J.; Guilloux, G.; Gushin, E.; Hall, J.; Hallman, T. J.; Hardtke, D.; Harper, G.; Harris, J. W.; He, P.; Heffner, M.; Heppelmann, S.; Herston, T.; Hill, D.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Howe, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Hunt, W.; Hunter, J.; Igo, G. J.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Jacobson, S.; Jared, R.; Jensen, P.; Johnson, I.; Jones, P. G.; Judd, E.; Kaneta, M.; Kaplan, M.; Keane, D.; Kenney, V. P.; Khodinov, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Koehler, G.; Konstantinov, A. S.; Kormilitsyne, V.; Kotchenda, L.; Kotov, I.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Krupien, T.; Kuczewski, P.; Kuhn, C.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamas-Valverde, J.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lecompte, T.; Leonhardt, W. J.; Leontiev, V. M.; Leszczynski, P.; Levine, M. J.; Li, Q.; Li, Q.; Li, Z.; Liaw, C.-J.; Lin, J.; Lindenbaum, S. J.; Lindenstruth, V.; Lindstrom, P. J.; Lisa, M. A.; Liu, H.; Ljubicic, T.; Llope, W. J.; Locurto, G.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Lopiano, D.; Love, W. A.; Lutz, J. R.; Lynn, D.; Madansky, L.; Maier, R.; Majka, R.; Maliszewski, A.; Margetis, S.; Marks, K.; Marstaller, R.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; Matyushevski, E. A.; McParland, C.; McShane, T. S.; Meier, J.; Melnick, Yu.; Meschanin, A.; Middlekamp, P.; Mikhalin, N.; Miller, B.; Milosevich, Z.; Minaev, N. G.; Minor, B.; Mitchell, J.; Mogavero, E.; Moiseenko, V. A.; Moltz, D.; Moore, C. F.; Morozov, V.; Morse, R.; de Moura, M. M.; Munhoz, M. G.; Mutchler, G. S.; Nelson, J. M.; Nevski, P.; Ngo, T.; Nguyen, M.; Nguyen, T.; Nikitin, V. A.; Nogach, L. V.; Noggle, T.; Norman, B.; Nurushev, S. B.; Nussbaum, T.; Nystrand, J.; Odyniec, G.; Ogawa, A.; Ogilvie, C. A.; Olchanski, K.; Oldenburg, M.; Olson, D.; Ososkov, G. A.; Ott, G.; Padrazo, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Pentia, M.; Perevotchikov, V.; Peryt, W.; Petrov, V. A.; Pinganaud, W.; Pirogov, S.; Platner, E.; Pluta, J.; Polk, I.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Puskar-Pasewicz, J.; Rai, G.; Rasson, J.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J.; Renfordt, R. E.; Retiere, F.; Ridiger, A.; Riso, J.; Ritter, H. G.; Roberts, J. B.; Roehrich, D.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Russ, D.; Rykov, V.; Sakrejda, I.; Sanchez, R.; Sandler, Z.; Sandweiss, J.; Sappenfield, P.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Scheblien, J.; Scheetz, R.; Schlueter, R.; Schmitz, N.; Schroeder, L. S.; Schulz, M.; Schüttauf, A.; Sedlmeir, J.; Seger, J.; Seliverstov, D.; Seyboth, J.; Seyboth, P.; Seymour, R.; Shakaliev, E. I.; Shestermanov, K. E.; Shi, Y.; Shimanskii, S. S.; Shuman, D.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Smykov, L. P.; Snellings, R.; Solberg, K.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Stone, N.; Stone, R.; Strikhanov, M.; Stringfellow, B.; Stroebele, H.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Symons, T. J.; Takahashi, J.; Tang, A. H.; Tarchini, A.; Tarzian, J.; Thomas, J. H.; Tikhomirov, V.; Szanto de Toledo, A.; Tonse, S.; Trainor, T.; Trentalange, S.; Tokarev, M.; Tonjes, M. B.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Vakula, I.; van Buren, G.; Vandermolen, A. M.; Vanyashin, A.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Visser, G.; Voloshin, S. A.; Vu, C.; Wang, F.; Ward, H.; Weerasundara, D.; Weidenbach, R.; Wells, R.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitfield, J. P.; Whitten, C.; Wieman, H.; Willson, R.; Wilson, K.; Wirth, J.; Wisdom, J.; Wissink, S. W.; Witt, R.; Wolf, J.; Wood, L.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yokosawa, A.; Yurevich, V. I.; Zanevski, Y. V.; Zhang, J.; Zhang, W. M.; Zhu, J.; Zimmerman, D.; Zoulkarneev, R.; Zubarev, A. N.

    2001-01-01

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at sNN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  3. Magnetic and mechanical properties of rolled-up Au/Co/Au nanomembranes with multiple windings

    NASA Astrophysics Data System (ADS)

    Müller, C.; de Souza, G. B.; Mikowski, A.; Schmidt, O. G.; Lepienski, C. M.; Mosca, D. H.

    2011-08-01

    Rolled-up Au/Co/Au microtubes with up to three windings were fabricated by the combination of strain engineering, conventional photolithography, and electron beam deposition. First, magnetization properties of the initial 2D film arrays and the corresponding tube arrays were studied and strong influences of magnetostrictive and shape anisotropy are observed. Second, the mechanical deformation was examined by an instrumented indentation technique at the nanoscale and analyzed by contact mechanics theory. The loading curve fitting in the elastic regime by the Hertz model provides a first approximation of the nanomembrane radial elastic modulus of about 135 GPa.

  4. Measuring away-side jet modifications in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Jiang, Kun; STAR Collaboration

    2015-08-01

    We report measurements of jet correlations in Au+Au collisions at = 200 GeV by the STAR experiment. In this analysis we devise a novel method to subtract flow background using data itself. The correlation width is studied as a function of centrality and associated particle pTT. The width is found to increase with centrality at modest to high associated particle pTT. The increase can arise from jet modification by medium and/or event averaging of away-side jets deflected by medium flow. The discrimination of the physics mechanisms requires further study by three-particle correlations.

  5. Beam Energy Scan a Case for the Chiral Magnetic Effect in Au-Au Collisions

    SciTech Connect

    Longacre, R.

    2014-01-05

    The Chiral Magnetic Effect (CME) is predicted for Au-Au collisions at RHIC. However, many backgrounds can give signals that make the measurement hard to interpret. The STAR experiment has made measurements at different collisions energy ranging from √(sNN)=7.7 GeV to 62.4 GeV. In the analysis that is presented we show that the CME turns on with energy and is not present in central collisions where the induced magnetic is small.

  6. Net charge fluctuations in Au + Au interactions at sqrt[s(NN)]=130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2002-08-19

    Data from Au + Au interactions at sqrt[s(NN)]=130 GeV, obtained with the PHENIX detector at the Relativistic Heavy-Ion Collider, are used to investigate local net charge fluctuations among particles produced near midrapidity. According to recent suggestions, such fluctuations may carry information from the quark-gluon plasma. This analysis shows that the fluctuations are dominated by a stochastic distribution of particles, but are also sensitive to other effects, like global charge conservation and resonance decays. PMID:12190459

  7. PARTON STRUCTURE THROUGH TWO PARTICLE CORRELATIONS IN AU-AU AT RHIC.

    SciTech Connect

    LONGACRE,R.S.

    1999-10-23

    A method for determining the presence of partonic scattering through two-particle correlations is developed and applied to models which have jets and mini-jets in them. We only consider the correlation of mid-rapidity particles because they will be easily measured in large numbers at RHIC. The level of two-particle correlations will be a direct measure of how dense a system is made in Au-Au collisions at RHIC. The STAR TPC will be ideal for making these measurements in the first year of running.

  8. Parton structure through two particle correlations in Au-Au at RHIC

    SciTech Connect

    Longacre, R.S.

    1998-12-31

    A method for determining the presence of partonic scattering through two-particle correlations is developed and applied to models which have jets and mini-jets in them. The author only considers the correlation of mid-rapidity particles because they will be easily measured in large numbers at RHIC. The level of two-particle correlations will be a direct measure of how dense a system is made in Au-Au collisions at RHIC. The STAR TPC will be ideal for making these measurements in the first year of running.

  9. On the nature of L1{sub 0} ordering in equiatomic AuNi and AuCu thin films grown on Au(001)

    SciTech Connect

    Dynna, M.; Marty, A.; Gilles, B.; Patrat, G.

    1997-01-01

    The L1{sub 0} ordering of thin epitaxial films having a (001) surface normal subject to elastic constraints imposed by a similarly oriented substrate has been investigated both experimentally and theoretically. Thin AuNi films grown by MBE at room temperature on Au(001) by means of the alternating deposition of Au and Ni are found to possess a L1{sub 0} structure free of periodic antiphase boundaries when growth is controlled in such a way as to ensure that the quantity of Au or Ni deposited is almost exactly equal to one monolayer. If such control is not exercised during growth, a structure having periodic antiphase boundaries is formed. This behavior stands in contrast to that of AuCu during room temperature MBE growth on Au(001), where a strongly ordered L2{sub 0} structure free of antiphase boundaries is formed even on the codeposition of Au and Cu. The effect of elastic constraints on the state of order in an alloy film which undergoes an L2{sub 0} order-disorder transition is examined as a function of temperature, lattice mismatch, and film thickness within the context of a model which allows for the introduction of dislocations in order to relieve misfit strain. Calculations are performed in detail for the case of AuCu, where particular attention is paid to the coupling between film thickness, the number of misfit dislocations present at equilibrium, and the state of order.

  10. Bridging gold in electron-deficient Al2Au(n)(0/-) and BAlAu(n)(0/-) (n = 1-3) clusters.

    PubMed

    Yao, Wen-Zhi; Liu, Bing-Tao; Lu, Zhang-Hui; Li, Si-Dian

    2013-06-20

    The geometrical and electronic structures of the electron-deficient dialuminum aurides Al2Aun(0/-) and hybrid boron-aluminum aurides BAlAun(0/-) (n = 1-3) are systematically investigated based on the density and wave function theories. Ab initio theoretical evidence strongly suggests that bridging gold atoms exist in the ground states of C2v Al2Au(-) ((3)B1), C2v Al2Au ((2)B1), C2v Al2Au2(-) ((2)A1), C2v Al2Au2 ((1)A1), Cs Al2Au3(-) ((1)A'), and D3h Al2Au3 ((2)A1), which prove to possess an Al-Au-Al τ bond. For BAlAun(0/-) (n = 1-3) mixed clusters, bridging B-Au-Al units only exist in Cs BAlAu3(-) ((1)A') and Cs BAlAu3 ((2)A'), whereas Cs BAlAu(-) ((3)A''), Cs BAlAu ((2)A''), Cs BAlAu2(-) ((2)A'), and Cs BAlAu2 ((1)A') do not possess a bridging gold, as demonstrated by the fact that B-Al and B-Au exhibit significantly stronger electronic interaction than Al-Au in the same clusters. Orbital analyses indicate that Au 6s contributes approximately 98%-99% to the Au-based orbital in these Al-Au-Al/B-Au-Al interactions, whereas Au 5d contributes 1%-2%. The adiabatic and vertical detachment energies of Al2Aun(-) (n = 1-3) are calculated to facilitate future experimental characterizations. The results obtained in this work establish an interesting τ bonding model (Al-Au-Al/B-Au-Al) for electron-deficient systems in which Au 6s plays a major factor. PMID:23718624

  11. Cu-Au, Ag-Au, Cu-Ag, and Ni-Au intermetallics: First-principles study of temperature-composition phase diagrams and structures

    NASA Astrophysics Data System (ADS)

    Ozoliņš, V.; Wolverton, C.; Zunger, Alex

    1998-03-01

    The classic metallurgical systems-noble-metal alloys-that have formed the benchmark for various alloy theories are revisited. First-principles fully relaxed general-potential linearized augmented plane-wave (LAPW) total energies of a few ordered structures are used as input to a mixed-space cluster expansion calculation to study the phase stability, thermodynamic properties, and bond lengths in Cu-Au, Ag-Au, Cu-Ag, and Ni-Au alloys. (i) Our theoretical calculations correctly reproduce the tendencies of Ag-Au and Cu-Au to form compounds and Ni-Au and Cu-Ag to phase separate at T=0 K. (ii) Of all possible structures, Cu3Au (L12) and CuAu (L10) are found to be the most stable low-temperature phases of Cu1-xAux with transition temperatures of 530 K and 660 K, respectively, compared to the experimental values 663 K and ~670 K. The significant improvement over previous first-principles studies is attributed to the more accurate treatment of atomic relaxations in the present work. (iii) LAPW formation enthalpies demonstrate that L12, the commonly assumed stable phase of CuAu3, is not the ground state for Au-rich alloys, but rather that ordered (100) superlattices are stabilized. (iv) We extract the nonconfigurational (e.g., vibrational) entropies of formation and obtain large values for the size-mismatched systems: 0.48 kB/atom in Ni0.5Au0.5 (T=1100 K), 0.37 kB/atom in Cu0.141Ag0.859 (T=1052 K), and 0.16 kB/atom in Cu0.5Au0.5 (T=800 K). (v) Using 8 atom/cell special quasirandom structures we study the bond lengths in disordered Cu-Au and Ni-Au alloys and obtain good qualitative agreement with recent extended x-ray-absorption fine-structure measurements.

  12. Universal lessons learned by a gastroenterologist from a deaf and mute patient: the importance of nonverbal communication and establishing patient rapport and trust.

    PubMed

    Cappell, Mitchell S

    2009-01-01

    Deaf and mute patients may require minimal extra attention to establish trust and allay anxieties before minor medical maneuvers such as rectal examination. An extreme case is reported of the consequences from failure to accomplish this. A generally cooperative deaf and mute patient struggled and suffered a rectal tear and perforation during enema insertion that required emergency colorectal surgery; his nurse had failed to establish a trusting relationship before enema insertion. Ironically, the patient's physician had earlier easily performed digital rectal examination, a similar medical maneuver, with patient cooperation after establishing patient rapport. This report demonstrates the importance of treating individuals with disabilities like everyone else in addressing anxieties before medical maneuvers. The health care worker has the same responsibility of calming the patient, whether deaf or not; the sole difference is that communication between deaf and hearing requires greater skill and patience. PMID:19957481

  13. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation

    NASA Astrophysics Data System (ADS)

    Hsu, Chiajen; Huang, Chienwen; Hao, Yaowu; Liu, Fuqiang

    2013-03-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies.

  14. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation.

    PubMed

    Hsu, Chiajen; Huang, Chienwen; Hao, Yaowu; Liu, Fuqiang

    2013-01-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies. PMID:23452438

  15. Au-Rh and Au-Pd nanocatalysts supported on rutile titania nanorods: structure and chemical stability.

    PubMed

    Konuspayeva, Zere; Afanasiev, Pavel; Nguyen, Thanh-Son; Di Felice, Luca; Morfin, Franck; Nguyen, Nhat-Tai; Nelayah, Jaysen; Ricolleau, Christian; Li, Z Y; Yuan, Jun; Berhault, Gilles; Piccolo, Laurent

    2015-11-14

    Au, Rh, Pd, Au-Rh and Au-Pd nanoparticles (NPs) were synthesized by colloidal chemical reduction and immobilized on hydrothermally-prepared rutile titania nanorods. The catalysts were characterized by aberration-corrected TEM/STEM, XPS, and FTIR, and were evaluated in the hydrogenation of tetralin in the presence of H2S. Oxidizing and reducing thermal treatments were employed to remove the polyvinyl alcohol (PVA) surfactant. Reduction in H2 at 350 C was found efficient for removing the PVA while preserving the size (ca. 3 nm), shape and bimetallic nature of the NPs. While Au-Pd NPs are alloyed at the atomic scale, Au-Rh NPs contain randomly distributed single-phase domains. Calcination-reduction of Au-Rh NPs mostly leads to separated Au and Rh NPs, while pre-reduction generates a well-defined segregated structure with Rh located at the interface between Au and TiO2 and possibly present around the NPs as a thin overlayer. Both the titania support and gold increase the resistance of Rh and Pd to oxidation. Furthermore, although detrimental to tetralin hydrogenation initial activity, gold stabilizes the NPs against surface sulfidation in the presence of 50 ppm H2S, leading to increased catalytic performances of the Au-Rh and Au-Pd systems as compared to their Rh and Pd counterparts. PMID:25765742

  16. Facile preparation of SERS-active nanostructured Au spheres by simple reduction of AuCl4- ions with EDOT.

    PubMed

    Hong, Jin-Yeon; Huh, Seong

    2014-03-15

    Uniform submicron-scale Au spheres with an average dimension of 574 nm were facilely prepared from the redox reaction between HAuCl4 and 3,4-ethylenedioxythiophene (EDOT) in aqueous solution under ambient conditions. HAuCl4 precursor readily polymerized to poly(3,4-ethylenedioxythiophene) (PEDOT) and metallic Au spheres simultaneously formed within a short period of time. The Au spheres are consisted of two slightly different types of spherical particles based on their surface textures. Major raspberry-like Au spheres are formed through the assembly of very tiny Au nanoparticles, while minor rosette-like Au spheres are formed through the dense packing of Au nanoplates. Both Au spheres are pure metallic face-centered cubic Au based on X-ray photoelectron spectroscopy and powder X-ray diffraction. The resultant Au spheres are adequate for application to surface-enhanced Raman scattering (SERS) due to their rough surfaces and nanogaps on the surfaces. Both methylene blue and crystal violet molecules were detectable at concentrations as low as 10(-7) M. PMID:24461856

  17. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation

    PubMed Central

    2013-01-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies. PMID:23452438

  18. Excited electronic states of AuF.

    PubMed

    Butler, Elissa K; Knurr, Benjamin J; Manke, Kara J; Vervoort, Tyson R; Varberg, Thomas D

    2010-04-15

    We have recorded laser excitation spectra of transitions from the ground X(1)Sigma(+) state of gaseous gold fluoride (AuF) into three excited electronic states in the visible region. We prepared the sample in a dc electric discharge by flowing a dilute mixture of SF(6) in argon through a hollow gold cathode. Two of these electronic states give rise to the previously reported yellow bands of the molecule, for which a rotational analysis is given here for the first time. We have analyzed the (0,0), (1,1), (0,1), and (1,2) bands of these two transitions, which we identify as [17.8]0(+)-X(1)Sigma(+) and [17.7]1-X(1)Sigma(+); their red-degraded (0,0) band heads lie at 563.0 and 566.2 nm, respectively. The (0,0) band of a new, red-degraded [14.0]1-X(1)Sigma(+) transition at 715.1 nm has also been recorded and analyzed. An accurate set of molecular constants of the three excited states as well as the ground state has been determined by least-squares fitting all of the optical data together with measurements made by other workers of the pure rotational spectrum of AuF in its ground state. These constants include the electronic term energies, vibrational frequencies, rotational constants, and Omega-doubling constants. We discuss the nature of these three excited electronic states in terms of the ionic Au(+)F(-) electronic configurations from which they are derived. PMID:20104862

  19. Atomic and molecular adsorption on Au(111)

    SciTech Connect

    Santiago-Rodríguez, Yohaselly; Herron, Jeffrey A.; Curet-Arana, María C.; Mavrikakis, Manos

    2014-09-01

    Periodic self-consistent density functional theory (DFT-GGA) calculations were used to study the adsorption of several atomic species, molecular species and molecular fragments on the Au(111) surface with a coverage of 1/4 monolayer (ML). Binding geometries, binding energies, and diffusion barriers were calculated for 27 species. Furthermore, we calculated the surface deformation energy associated with the binding events. The binding strength for all the analyzed species can be ordered as follows: NH3 < NO < CO < CH3 < HCO < NH2 < COOH < OH < HCOO < CNH2 < H < N < NH < NOH < COH < Cl,< HCO3 < CH2 < CN b HNO < O < F < S < C < CH. Although the atomic species preferred to bind at the three-fold fcc site, no tendency was observed in site preference for the molecular species and fragments. The intramolecular and adsorbate-surface vibrational frequencies were calculated for all the adsorbates on their most energetically stable adsorption site. Most of the theoretical binding energies and frequencies agreed with experimental values reported in the literature. In general, the values obtained with the PW91 functional are more accurate than RPBE in reproducing these experimental binding energies. The energies of the adsorbed species were used to calculate the thermochemical potential energy surfaces for decomposition of CO, NO, N2, NH3 and CH4, oxidation of CO, and hydrogenation of CO, CO2 and NO, giving insight into the thermochemistry of these reactions on gold nanoparticles. These potential energy surfaces demonstrated that: the decomposition of species is not energetically favorable on Au(111); the desorption of NH3, NO and CO are more favorable than their decomposition; the oxidation of CO and hydrogenation of CO and NO on Au(111) to form HCO and HNO, respectively, are also thermodynamically favorable.

  20. Atomic and molecular adsorption on Au(111)

    NASA Astrophysics Data System (ADS)

    Santiago-Rodríguez, Yohaselly; Herron, Jeffrey A.; Curet-Arana, María C.; Mavrikakis, Manos

    2014-09-01

    Periodic self-consistent density functional theory (DFT-GGA) calculations were used to study the adsorption of several atomic species, molecular species and molecular fragments on the Au(111) surface with a coverage of 1/4 monolayer (ML). Binding geometries, binding energies, and diffusion barriers were calculated for 27 species. Furthermore, we calculated the surface deformation energy associated with the binding events. The binding strength for all the analyzed species can be ordered as follows: NH3 < NO < CO < CH3 < HCO < NH2 < COOH < OH < HCOO < CNH2 < H < N < NH < NOH < COH < Cl < HCO3 < CH2 < CN < HNO < O < F < S < C < CH. Although the atomic species preferred to bind at the three-fold fcc site, no tendency was observed in site preference for the molecular species and fragments. The intramolecular and adsorbate-surface vibrational frequencies were calculated for all the adsorbates on their most energetically stable adsorption site. Most of the theoretical binding energies and frequencies agreed with experimental values reported in the literature. In general, the values obtained with the PW91 functional are more accurate than RPBE in reproducing these experimental binding energies. The energies of the adsorbed species were used to calculate the thermochemical potential energy surfaces for decomposition of CO, NO, N2, NH3 and CH4, oxidation of CO, and hydrogenation of CO, CO2 and NO, giving insight into the thermochemistry of these reactions on gold nanoparticles. These potential energy surfaces demonstrated that: the decomposition of species is not energetically favorable on Au(111); the desorption of NH3, NO and CO are more favorable than their decomposition; the oxidation of CO and hydrogenation of CO and NO on Au(111) to form HCO and HNO, respectively, are also thermodynamically favorable.

  1. Unveiling the origin of oxygen atomic impurities in Au nanowires

    NASA Astrophysics Data System (ADS)

    Nascimento, A. P. F.; San-Miguel, Miguel A.; da Silva, E. Z.

    2014-02-01

    The appearance of unusually large Au-Au bond distances in linear atomic chains (LACs) of Au nanowires is commonly attributed to the presence of atomic impurities. However, the origin of those contaminants is unknown. We present a study based on density functional theory calculations using quasistatic (T =0) and finite-temperature ab initio molecular-dynamics simulations of a possible route for the formation of atomic impurities in Au nanowires. This process starts with the adsorption of an O2 molecule followed by a CO molecule on Au LACs, leading to the formation of an intermediate O2CO complex. Upon thermal activation at finite temperatures, the complex is able to proceed to oxidation forming a CO2 molecule and leaving an atomic O impurity in the Au LAC.

  2. Le don après un décès d'origine cardiocirculatoire au Canada

    PubMed Central

    Shemie, Sam D.; Baker, Andrew J.; Knoll, Greg; Wall, William; Rocker, Graeme; Howes, Daniel; Davidson, Janet; Pagliarello, Joe; Chambers-Evans, Jane; Cockfield, Sandra; Farrell, Catherine; Glannon, Walter; Gourlay, William; Grant, David; Langevin, Stéphan; Wheelock, Brian; Young, Kimberly; Dossetor, John

    2006-01-01

    Résumé Ces recommandations sont le fruit d'un processus multidisciplinaire national ayant duré un an et visant à déterminer si et comment l'on pourrait procéder au don d'organes après un décès d'origine cardiocirculatoire («don après le décès cardiocirculatoire», ou DDC) au Canada. Le forum national organisé en février 2005 a permis aux participants de discuter et d'élaborer des recommandations sur les principes, interventions et pratiques se rapportant au DDC. Les aspects éthiques et juridiques ont été abordés dans les discussions. À la fin du Forum, la majorité des participants ont été favorables à l'implantation de programmes de DDC au Canada. Les participants du Forum ont également convenu qu'il fallait formuler et prôner des valeurs fondamentales pour orienter l'élaboration de programmes et de protocoles basés sur le cadre médical, éthique et juridique établi lors de cette réunion. Même si la possibilité d'un don d'organes et de tissus doit faire partie intégrante des soins de fin de vie, il faut insister sur le fait que le devoir de diligence envers les patients mourants et leurs familles doit demeurer la priorité des équipes soignantes. La complexité et les répercussions profondes du décès sont reconnues et doivent être respectées, de même que les différences personnelles, ethnoculturelles et religieuses face à la mort et au don d'organes. Les décisions d'arrêter le traitement de maintien des fonctions vitales, la prise en charge des derniers moments de la vie et le diagnostic de décès selon des critères cardiocirculatoires doivent être distincts et indépendants des processus de don et transplantation. Ce rapport contient des recommandations destinées aux gestionnaires de program, aux autorités sanitaires régionales et aux instances appelés à élaborer les protocoles de DDC. Les programmes doivent être conçus en fonction des éléments suivants : direction et planification locales, éducation et engagement des intervenants, mécanismes d'assurance de la sécurité et de la qualité et information du public. Il est recommandé de commencer par un program de DDC contrôlé à l'unité de soins intensifs où, après une décision par consentement mutuel de cesser le traitement de maintien des fonctions vitales, la mort est attendue, mais n'est pas survenue, ce qui rend possible des discussions non précipitées sur le consentement. Un don non contrôlé, en cas de décès après un arrêt cardiaque non prévu, doit être envisagé seulement une fois que le program de DDC contrôlé a été établi. Bien qu'il soit recommandé de restreindre le programme initial au don de reins, le don d'autres organes peut aussi être envisagé selon l'expertise régionale en matière de transplantation. Les répercussions d'un DDC, y compris les interventions pratiquées avant et après le décès, sur la famille du donneur, la disponibilité des organes, la fonction du greffon et la survie du receveur doivent être documentées de façon méthodique et examinées.

  3. Enhanced Photoresponse of Conductive Polymer Nanowires Embedded with Au Nanoparticles.

    PubMed

    Zhang, Junchang; Zhong, Liubiao; Sun, Yinghui; Li, Anran; Huang, Jing; Meng, Fanben; Chandran, Bevita K; Li, Shuzhou; Jiang, Lin; Chen, Xiaodong

    2016-04-01

    A conductive polymer nanowire embedded with a 1D Au nanoparticle chain with defined size, shape, and interparticle distance is fabricated which demonstrates enhanced photoresponse behavior. The precise and controllable positioning of 1D Au nanoparticle chain in the conductive polymer nanowire plays a critical role in modulating the photoresponse behavior by excitation light wavelength or power due to the coupled-plasmon effect of 1D Au nanoparticle chain. PMID:26901850

  4. African Regional Symposium on Telematics for Development. Report and Recommendations = Colloque regional africain la telematique au service du developpement. Rapport et recommandations (Addis Ababa, Ethiopia, April 3-7, 1995).

    ERIC Educational Resources Information Center

    International Telecommunication Union, Geneva (Switzerland).

    The African Regional Symposium on Telematics for Development was organized in view of the special educational and communication needs of Africa in a time of accelerating change and development of information technologies. The symposium brought together more than 150 African specialists, and over 40 participants from other regions and development

  5. African Regional Symposium on Telematics for Development. Report and Recommendations = Colloque regional africain la telematique au service du developpement. Rapport et recommandations (Addis Ababa, Ethiopia, April 3-7, 1995).

    ERIC Educational Resources Information Center

    International Telecommunication Union, Geneva (Switzerland).

    The African Regional Symposium on Telematics for Development was organized in view of the special educational and communication needs of Africa in a time of accelerating change and development of information technologies. The symposium brought together more than 150 African specialists, and over 40 participants from other regions and development…

  6. Workplace Education Practitioners' Forum Summary Report (Winnipeg, Manitoba, Canada, March 4-6, 1999) = Forum des practiciens de l'education en milieu de travail rapport sommaire (Winnipeg, Manitoba, Canada, 4 au 6 mars 1999).

    ERIC Educational Resources Information Center

    Roger, Margerit; Nichol, Louise

    A forum was conducted to give workplace education practitioners (WEPs) from across Canada the opportunity to have an initial discussion on WEP development and recognition. The forum included presentations by forum participants, forum discussions, and brainstorming sessions on the following and other topics: roles and working contexts of WEPs in…

  7. A Cappella: A Report on the Realities, Concerns, Expectations and Barriers Experienced by Adolescent Women in Canada = A Cappella: Rapport sur les realites, preoccupations, attentes et obstacles que connaissent les adolescentes au Canada.

    ERIC Educational Resources Information Center

    Canadian Teachers' Federation, Ottawa (Ontario).

    In the spring of 1990 a project was undertaken in Canada to document the major concerns and perceptions of adolescent women; to supplement the words of adolescent women with brief summaries of current knowledge; to use the words of adolescent women and the additional knowledge gathered to provide information to young women on issues which are of…

  8. Photoionization of Au+ ions and developments in the synthesis of the metallofullerene Au@C60

    NASA Astrophysics Data System (ADS)

    Bogolub, Kyren; Macaluso, David; Mueller, Allison; Johnson, Andrea; Müller, Alfred; Schippers, Stefan; Hellhund, Jonas; Borovik, Alexander; Anders, Andre; Aguilar, Alex; Kilcoyne, A. L. David

    2014-05-01

    Single photoionization of Au+ ions was investigated via the merged-beams technique at AMO Beamline 10.0.1.2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. The relative single photoionization yield was measured as a function of photon energy in the 45 eV to 120 eV energy range. These measurements were made in preparation for future photoionization studies of the endohedral metallofullerene Au@C60, the production of which was also investigated. In proof-of-principle measurements a mass-resolved beam of Au@C60+was produced with a primary ion beam current in the single picoamp range without optimization of the ion source or synthesis parameters. Plans are presented for improved metallofullere production yield to be used in photoionization measurements of the endohedral fullerene ions in conjunction with the continuing study of pure Au. We would like to acknowledge the generous sharing of equipment vital to this work by Andre Anders, the Plasma Applications group leader at the Advanced Light Source, LBNL.

  9. Degree of chemical nonequilibrium in central Au-Au collisions at RHIC energies

    NASA Astrophysics Data System (ADS)

    Tawfik, Abdel Nasser; El-Bakry, M. Y.; Habashy, D. M.; Mohamed, M. T.; Abbas, Ehab

    2015-08-01

    In this paper, we investigate the difference between hadron resonance gas (HRG) calculations for chemical freeze-out parameters at fully and partly chemical equilibria. To this end, the results are compared with the particle ratios measured in central Au-Au collisions at a wide range of nucleon-nucleon center-of-mass energies, √ {s{ NN}} = 7.7 - 200 ; GeV as offered by the STAR experiment. We restrict the discussion to STAR, because of large statistics and overall homogeneity of STAR measurements (one detector) against previous experiments. We find that the matter produced at these energies is likely in fully chemical equilibria, which is consistent with recent lattice quantum chromodynamics (QCD) results. The possible improvements by partial chemical equilibria (γS ≠ 1) are very limited. We also discuss these results with the ones deduced from ϕ/π- and Ω-/π- ratios. These hadron ratios are sensitive to the degree of chemical equilibrium. Accordingly, the conclusion that the matter produced reaches fully chemical equilibria in central Au-Au at relativistic heavy-ion collider (RHIC) energies is confirmed.

  10. Systematic studies of the centrality dependence of soft photon production in Au + Au collision with PHENIX

    NASA Astrophysics Data System (ADS)

    Bannier, Benjamin

    2014-11-01

    Since the earliest days of Heavy Ion Physics thermal soft photon radiation emitted during the reaction had been theorized as a smoking gun signal for formation of a quark-gluon plasma and as a tool to characterize its properties. In recent years the existence of excess photon radiation in heavy ion collisions over the expectation from initial hard interactions has been confirmed at both RHIC and LHC energies by PHENIX and ALICE respectively. There the radiation has been found to exhibit elliptic flow v2 well above what can currently be reconciled with a picture of early emission from a plasma phase. During the 2007 and 2010 Au + Au runs PHENIX has measured a high purity sample of soft photons down to pT > 0.4 GeV / c using an external conversion method. We present recent systematic studies by PHENIX from that sample on the centrality dependence of the soft photon yield, and elliptic and triangular flow v2 and v3 in Au + Au collisions which fill in the experimental picture and enable discrimination of competing soft photon production scenarios.

  11. Energy and system size dependence of ϕ meson production in Cu + Cu and Au + Au collisions

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betancourt, M. J.; Betts, R. R.; Bharadwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bruna, E.; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Callner, J.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J.; Coffin, J. P.; Corliss, R.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; De Silva, C.; Dedovich, T. G.; DePhillips, M.; Derevschikov, A. A.; Derradi de Souza, R.; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunlop, J. C.; Dutta Mazumdar, M. R.; Edwards, W. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gaillard, L.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Leight, W.; LeVine, M. J.; Li, C.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meschanin, A.; Millner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X.-H.; Sichtermann, E.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trattner, A. L.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Leeuwen, M.; Molen, A. M. Vander; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasilevski, I. M.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Walker, M.; Wang, F.; Wang, G.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, J. C.; Westfall, G. D.; Whitten, C.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, H.; Zhang, S.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zuo, J. X.; STAR Collaboration

    2009-03-01

    We study the beam-energy and system-size dependence of ϕ meson production (using the hadronic decay mode ϕ →K+K-) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at √{sNN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented in this Letter are from mid-rapidity (| y | < 0.5) for 0.4 Au + Au colliding systems with similar average numbers of participating nucleons. The ϕ meson yields in nucleus-nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p + p collisions. The enhancement for ϕ mesons lies between strange hadrons having net strangeness =1 (K- and Λbar) and net strangeness =2 (Ξ). The enhancement for ϕ mesons is observed to be higher at √{sNN} = 200 GeV compared to 62.4 GeV. These observations for the produced ϕ (ssbar) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.

  12. Al3AuIr: A New Compound in the Al-Au-Ir System.

    PubMed

    Kadok, Joris; de Weerd, Marie-Cécile; Boulet, Pascal; Gaudry, Émilie; Grin, Yuri; Fournée, Vincent; Ledieu, Julian

    2015-08-17

    A new ternary phase with a composition of Al3AuIr has been found in the Al-rich area of the Al-Au-Ir system. Differential thermal analysis indicates a melting point of 990 °C, and single-crystal X-ray diffraction measurements reveal that this ternary phase adopts a Ni2Al3 structure type (space group P3̅m1) with a = 4.2584(5) Å and c = 5.1991(7) Å. This compound is isostructural to the Al3Cu1.5Co0.5 phase also found in the Al-rich part of the Al-Cu-Co ternary diagram. Experimental evidence combined with ab initio calculations point toward an Al3AuIr phase stabilized by a Hume-Rothery mechanism. Quantum chemical calculations indicate two-center and multicenter interactions in the Al3AuIr phase. Layered distribution of two-center interactions separated by regions with four- and five-center bonds suggests a preferential cleavage of the material at puckered planes perpendicular to the [001] direction. PMID:26241194

  13. RHIC performance for FY2011 Au+Au heavy ion run

    SciTech Connect

    Marr, G.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Drees, K.A.; Fedotov, A.V.; Fischer, W.; Fu, W.; Gardner, C.J.; Gassner, D.M.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Ingrassia, P.F.; Jamilkowski, J.P.; Kling, N.; Lafky, M.; Laster, J.S.; Liu, C.; Luo, Y.; Mapes, M.; Marusic, A.; Mernick, K.; Michnoff, R.J.; Minty, M.G.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Polizzo, S.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Sandberg, J.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.; Steski, D.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; VanKuik, B.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-09-04

    Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run, RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of 'common' RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals. At the conclusion of the FY 2011 polarized proton run, preparations for heavy ion run proceeded on April 18, with Au+Au collisions continuing through June 28. Our standard operations at 100 GeV/nucleon beam energy was bracketed by two shorter periods of collisions at lower energies (9.8 and 13.5 GeV/nucleon), continuing a previously established program of low and medium energy runs. Table 1 summarizes our history of heavy ion operations at RHIC.

  14. Découverte fortuite de quadruplets au cours d'un accouchement: illustration d'un cas à l'Hôpital Central de Yaoundé (Cameroun)

    PubMed Central

    Fouelifack, Florent Ymele; Fouedjio, Jeanne Hortence; Dingom, Madye Ange Ngo; Fouogue, Jovanny Tsuala; Enow, Robinson Mbu

    2014-01-01

    Les auteurs rapportent une grossesse de haut rang (quadruplés) dont le nombre de fœtus n'a été découvert que pendant l'accouchement par voie vaginale. Faute de moyens, la parturiente reçue en phase active du travail n'a pas pu bénéficier de la césarienne d'urgence indiquée pour présentation en siège du premier jumeau. Ce n'est qu'après l'accouchement du deuxième fœtus que les deux derniers quadruplés ont été successivement découverts. Les difficultés et les pièges contextuels de la prise en charge des grossesses multiples sont passés en revue. Ce cas rappelle au personnel des salles d'accouchement la possibilité d'erreur de diagnostique sur les résultats d'échographies présentés par les parturientes. PMID:25419323

  15. Identifying Au-based Te alloys for optical data storage

    NASA Astrophysics Data System (ADS)

    Wamwangi, D.; Detemple, R.; Woeltgens, H.-W.; Wuttig, M.; Zhang, X.

    2004-06-01

    Au18Sb23Te59 and Au19In26Te55 have been investigated to determine their suitability as phase change recording alloys. Recrystallization experiments identify Au18Sb23Te59 as a suitable phase change material with a recrystallization time of 110 ns and high optical contrast. Coupled to the high optical contrast is a considerable density increase of 4% upon crystallization which allows phase change recording for the Au18Sb23Te59 alloy. On the other hand no recrystallization has been observed optically for Au19In26Te55 due to its low optical contrast of less than 1%. This is related to a lower density contrast of 2%. The crystallization for the Au18Sb23Te59 and Au19In26Te55 alloys observed from temperature-dependent sheet resistance measurements have yielded transition temperatures of 113 and 175 °C, and activation barriers of 1.61±0.01 eV and 2.42±0.02 eV, respectively. We report a cubic structure (a=2.99±0.002 Å) for the Au18Sb23Te59 alloy and a chalcopyrite structure (a=6.50±0.018 Å and 12.27±0.025 Å) for the Au19In26Te55 material. These results confirm that suitable phase change alloys possess cubic structures rather than the chalcopyrite structure typical for sp3 bonded semiconductors.

  16. Local anodic oxidation patterning of Au deposited Si surfaces.

    PubMed

    Vijaykumar, T; Kulkarni, G U

    2009-09-01

    Nanopatterning of Si(100) surfaces deposited with Au films from physical and chemical methods, has been carried out using a AFM set up mounted with a conducting tip. At a tip bias of -12 V, the LAO patterns drawn on various Au/SiOx surfaces have been compared with those on bare Si. The height of the oxide patterns is several times higher in the case of Au covered Si surfaces compared to patterns on bare Si surface. The enhancement in LAO is related to the catalytic activity of Au nanoparticulates at SiOx interface. PMID:19928226

  17. Structure sensitive adsorption of DMSO on Au surfaces

    SciTech Connect

    Ikemiya, N.; Gewirth, A.A.

    2000-02-10

    Using a variable temperature STM, the authors have observed the absorption of DMSO on Au(100) and Au(111) surfaces at temperatures below 215 K. For DMSO on Au(100), the molecules are trapped on the terraces at high points on the hex reconstruction giving rise to an ordered low coverage phase. Consistent with data from previous temperature programmed desorption (TPD) measurements, this phase coexists with a higher coverage striped phase formed when the DMSO molecules associate with each other. On Au(111), the DMSO molecules nucleate, order, and grow only from step edges; the steps are the only appropriately electropositive sites on this surface.

  18. Structural and optical studies of Au doped titanium oxide films

    NASA Astrophysics Data System (ADS)

    Alves, E.; Franco, N.; Barradas, N. P.; Nunes, B.; Lopes, J.; Cavaleiro, A.; Torrell, M.; Cunha, L.; Vaz, F.

    2012-02-01

    Thin films of TiO 2 were doped with Au by ion implantation and in situ during the deposition. The films were grown by reactive magnetron sputtering and deposited in silicon and glass substrates at a temperature around 150 °C. The undoped films were implanted with Au fluences in the range of 5 × 10 15 Au/cm 2-1 × 10 17 Au/cm 2 with a energy of 150 keV. At a fluence of 5 × 10 16 Au/cm 2 the formation of Au nanoclusters in the films is observed during the implantation at room temperature. The clustering process starts to occur during the implantation where XRD estimates the presence of 3-5 nm precipitates. After annealing in a reducing atmosphere, the small precipitates coalesce into larger ones following an Ostwald ripening mechanism. In situ XRD studies reveal that Au atoms start to coalesce at 350 °C, reaching the precipitates dimensions larger than 40 nm at 600 °C. Annealing above 700 °C promotes drastic changes in the Au profile of in situ doped films with the formation of two Au rich regions at the interface and surface respectively. The optical properties reveal the presence of a broad band centered at 550 nm related to the plasmon resonance of gold particles visible in AFM maps.

  19. Preparations for p-Au run in 2015

    SciTech Connect

    Liu, C.

    2014-12-31

    The p-Au particle collision is a unique category of collision runs. This is resulted from the different charge mass ratio of the proton and fully stripped Au ion (1 vs.79/197). The p-Au run requires a special acceleration ramp, and movement of a number of beam components as required by the beam trajectories. The DX magnets will be moved for the first time in the history of RHIC. In this note, the planning and preparations for p-Au run will be presented.

  20. An Exploration of Catalytic Chemistry on Au/Ni(111)

    SciTech Connect

    Sylvia T. Ceyer

    2011-12-09

    This project explored the catalytic oxidation chemistry that can be effected on a Au/Ni(111) surface alloy. A Au/Ni(111) surface alloy is a Ni(111) surface on which less than 60% of the Ni atoms are replaced at random positions by Au atoms. The alloy is produced by vapor deposition of a small amount of Au onto Ni single crystals. The Au atoms do not result in an epitaxial Au overlayer or in the condensation of the Au into droplets. Instead, Au atoms displace and then replace Ni atoms on a Ni(111) surface, even though Au is immiscible in bulk Ni. The two dimensional structure of the clean Ni surface is preserved. This alloy is found to stabilize an adsorbed peroxo-like O2 species that is shown to be the critical reactant in the low temperature catalytic oxidation of CO and that is suspected to be the critical reactant in other oxidation reactions. This investigation revealed a new, practically important catalyst for CO oxidation that has since been patented.

  1. Competition between Order and Phase Separation in Au-Ni

    SciTech Connect

    Reichert, H.; Schoeps, A.; Ramsteiner, I.B.; Bugaev, V.N.; Shchyglo, O.; Udyansky, A.; Dosch, H.; Asta, M.; Drautz, R.; Honkimaeki, V.

    2005-12-02

    We have measured and theoretically analyzed the diffuse scattering in the binary alloy system Au-Ni, which has been proposed as a testing ground for theories of alloy phase stability. We found strong evidence that in the alloys Au{sub 3}Ni and Au{sub 3}Ni{sub 2}, fluctuations of both ordering- and clustering-type are competing with each other. Our results resolve a long-standing controversy on the balance of relaxation and mixing energies in this alloy system and explain recent findings of ordering in thin Au-Ni films.

  2. Atomistic simulations of Au-silica nanocomposite film growth

    NASA Astrophysics Data System (ADS)

    Khan, Saif A.; Heinig, K.-H.; Avasthi, D. K.

    2011-05-01

    The growth of Au-silica nanocomposite film is simulated in the framework of kinetic three dimensional lattice Monte Carlo simulations considering the basic phenomena in the deposition process. In case of co-sputter deposition, the growth kinetics of nanoparticles has been studied taking into consideration the effect of the energetic sputtered species reaching the surface of the film during deposition. Formation of Au nanorod like structures are predicted under certain growth conditions particularly when surface diffusion assisted phase separation plays the dominant role and bulk kinetics is frozen. The observed dependence of the Au nanoparticle size on Au/silica ratio is in agreement with the experimental results.

  3. Alkynyl-protected Au23 nanocluster: a 12-electron system.

    PubMed

    Wan, Xian-Kai; Yuan, Shang-Fu; Tang, Qing; Jiang, De-en; Wang, Quan-Ming

    2015-05-11

    A 23-gold-atom nanocluster was prepared by NaBH4-mediated reduction of a solution of PhC≡CAu and Ph3PAuSbF6 in CH2Cl2. The cluster composition was determined to be [Au23(PhC≡C)9(Ph3P)6](2+) and single-crystal X-ray diffraction revealed that the cluster has an unprecedented Au17 kernel protected by three PhC2-Au-C2 (Ph)-Au-C2 Ph motifs and six Ph3P groups. The Au17 core can be viewed as the fusion of two Au10 units sharing a Au3 triangle. Electronic structure analysis from DFT calculations suggests that the stability of this unusual 12-electron cluster is a result of the splitting of the superatomic 1D orbitals under D3h symmetry of the Au17 kernel. The discovery and determination of the structure of the Au23 cluster demonstrates the versatility of the alkynyl ligand in leading to the formation of new cluster compounds. PMID:25808199

  4. Observation of D0 Meson Nuclear Modifications in Au +Au Collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-10-01

    We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K-+π+) in Au +Au collisions at √sNN =200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p +p to central Au +Au collisions. The D0 meson yields in central Au +Au collisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV /c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

  5. Heterostructured Au/Pd-M (M = Au, Pd, Pt) nanoparticles with compartmentalized composition, morphology, and electrocatalytic activity.

    PubMed

    Lutz, Patrick S; Bae, In-Tae; Maye, Mathew M

    2015-10-14

    The synthesis, processing, and galvanic exchange of three heterostructured nanoparticle systems is described. The surface accessibility and redox potential of a Au/Pd-Ag dumbbell nanoparticle, where a Au/Pd core/shell region, and a silver region make up the domains, was used to prepare the new nanostructures with controlled composition, morphology, and microstructure. Results indicate that the silver domain was particularly susceptible to galvanic displacement, and was exchanged to Au/Pd-M (M = Au, Pd, Pt). Interestingly, the dumbbell morphology remained after exchange, and the silver region was transformed to hollow, parachute, or concentric domains respectively. The morphology and microstructure change was visualized via TEM and HRTEM, and the composition changes were probed via STEM-EDS imaging and XPS. The electrocatalytic activity of the Au/Pd-M towards methanol oxidation was studied, with results indicating that the Au/Pd-Pt nanoparticles had high activity attributed to the porous nature of the platinum domains. PMID:26351824

  6. Imaging Prominence Eruptions out to 1 AU

    NASA Astrophysics Data System (ADS)

    Wood, Brian E.; Howard, Russell A.; Linton, Mark G.

    2016-01-01

    Views of two bright prominence eruptions trackable all the way to 1 AU are here presented, using the heliospheric imagers on the Solar TErrestrial RElations Observatory (STEREO) spacecraft. The two events first erupted from the Sun on 2011 June 7 and 2012 August 31, respectively. Only these two examples of clear prominence eruptions observable this far from the Sun could be found in the STEREO image database, emphasizing the rarity of prominence eruptions this persistently bright. For the 2011 June event, a time-dependent 3D reconstruction of the prominence structure is made using point-by-point triangulation. This is not possible for the August event due to a poor viewing geometry. Unlike the coronal mass ejection (CME) that accompanies it, the 2011 June prominence exhibits little deceleration from the Sun to 1 AU, as a consequence moving upwards within the CME. This demonstrates that prominences are not necessarily tied to the CME's magnetic structure far from the Sun. A mathematical framework is developed for describing the degree of self-similarity for the prominence's expansion away from the Sun. This analysis suggests only modest deviations from self-similar expansion, but close to the Sun the prominence expands radially somewhat more rapidly than self-similarity would predict.

  7. Centrality dependence of kaon yields in Si+A and Au+Au collisions at relativistic energies

    SciTech Connect

    Kaufman, S.; Ashktorab, K.; Beavis, D.; Chasman, C.; Chen, Z.; Chu, Y.Y.; Cumming, J.B.; Debbe, R.; Gonin, M.; Gushue, S.; Hayashi, S.; LeVine, M.J.; Moskowitz, B.; Olness, J.; Remsberg, L.P.; Roehrich, D.; Tannenbaum, M.J.; van Dijk, J.H.; Videbaek, F.; Wegner, H.E.; Zhu, F.; Crawford, H.J.; Engelage, J.; Beery, P.; Chang, J.; Eldredge, W.; Fung, S.Y.; Kang, J.; Seto, R.; Xu, G.H.; Zhu, Q.; Chi, C.Y.; Cole, B.A.; Kurita, K.; Moulson, M.; Nagamiya, S.; Nayak, T.K.; Stankus, P.; Vossnack, O.; Wang, F.; Wang, Y.; Wu, Y.; Yang, X.; Zajc, W.A.; Akiba, Y.; Homma, S.; Shigaki, K.; Tanaka, Y.; Kaneko, H.; Britt, H.C.; Luke, J.; Namboodiri, M.N.; Sangster, T.C.; Thomas, J.H.; Tonse, S.R.; Ahle, L.; Baker, M.; Cianciolo, V.; Costales, J.B.; Dunlop, J.C.; Heintzelman, G.; Judd, E.; Kehoe, W.L.; Ledoux, R.J.; Morrison, D.P.; Morse, R.J.; Ogilvie, C.A.; Parsons, C.G.; Rothschild, P.; Soltz, R.; Steadman, S.G.; Stephans, G.S.; Sung, T.W.; Vutsadakis, V.; Woodruff, D.; Zachary, D.; Budick, B.; Gaardhoje, J.; Hansen, A.; Hansen, L.; Hansen, O.; and others

    1999-10-01

    Charged kaon production has been measured in Si+Al and Si+Au collisions at 14.6A GeV/c, and Au+Au collisions at 11.1A GeV/c by Experiments 859 and 866 (the E-802 Collaboration) at the BNL AGS. Invariant transverse mass spectra and rapidity distributions for both K{sup +} and K{sup {minus}} are presented. The centrality dependence of rapidity-integrated kaon yields is studied. Strangeness enhancement is observed as an increase in the slope of the kaon yield with the total number of participants as well as the yield per participant. The enhancement starts with peripheral Si+Al and Si+Au collisions (relative to N+N) and appears to saturate for a moderate number of participating nucleons in Si+Au collisions. It is also observed to increase slowly with centrality in Au+Au collisions, to a level in the most central Au+Au collisions that is greater than that found in central Si+A collisions. The enhancement factors for K{sup +} production are 3.0{plus_minus}0.2(stat){plus_minus}0.4(syst) and 4.0{plus_minus}0.3(stat){plus_minus}0.5(syst), respectively, for the most central 7{percent} Si+Au collisions and the most central 4{percent} Au+Au collisions relative to N+N at the correponding beam energy. {copyright} {ital 1999} {ital The American Physical Society}

  8. Analyse sérologique de la toxoplasmose pergravidique: évaluation des risques et perspectives du dépistage prénatal au centre hospitalier universitaire de Bobo Dioulasso au Burkina Faso

    PubMed Central

    Bamba, Sanata; Some, Der Adolphe; Chemla, Cathy; Geers, Régine; Guiguemde, Tinga Robert; Villena, Isabelle

    2012-01-01

    Introduction La présente étude rapporte les données sérologiques de 306 sérums collectés chez des parturientes au CHU de Bobo Dioulasso et analysés rétrospectivement au CHU de Reims en 2011. Le but était de déterminer le statut sérologique de ces parturientes et d'en déduire la conduite à tenir. Méthodes La recherche des IgG et des IgM anti toxoplasmiques était systématique. Les techniques d'agglutination haute sensibilisée et celle d'Immunocapture M ont servi à la recherche respective des anticorps spécifiques IgG et des IgM. Résultats Sur 306 sérums analysés, 95 (31%) avaient des IgG positifs et aucun n'avait des IgM. Deux cent onze (211) sérums (69%) des sérums n'avaient ni IgG, ni IgM. Conclusion Nos résultats montrent que 31% des femmes en dehors d'une immunodépression sous jacente, possèdent une immunité résiduelle vis à vis de Toxoplasma gondii et n'ont pas la nécessité d'avoir une surveillance sérologique pendant la grossesse. Cependant, 69% (211) des parturientes sont à risque d'une séroconversion, et devraient bénéficier de conseils hygiéno diététiques, associés à une surveillance sérologique durant la grossesse. Ces résultats montrent l'intérêt de mettre en place des mesures de prévention contre la toxoplasmose congénitale, étant l'une des affections materno - foetales les plus fréquentes par la mise en place d'un diagnostic prénatal de la toxoplasmose en routine dans notre hôpital. PMID:22937183

  9. Ordered arrays of Au catalysts by FIB assisted heterogeneous dewetting

    NASA Astrophysics Data System (ADS)

    Benkouider, A.; Ronda, A.; David, T.; Favre, L.; Abbarchi, M.; Naffouti, M.; Osmond, J.; Delobbe, A.; Sudraud, P.; Berbezier, I.

    2015-12-01

    Synthesizing Au0.8Si0.2 nanocatalysts that are homogeneous in size and have controlled position is becoming a challenging and crucial prequisite for the fabrication of ordered semiconductor nanowires. In this study, Au0.8Si0.2 nanocatalysts are synthesized via dewetting of Au layers on Si(111) during thermal annealing in an ultra-high vacuum. In the first part of the paper, the mechanism of homogeneous dewetting is analyzed as a function of the Au-deposited thickness (h Au). We distinguish three different dewetting regimes: (I) for a low thickness ({h}{{Au}}≤slant 0.4 {nm}), a submonolyer coverage of Au is stabilized and there is no dewetting. (II) For an intermediate thickness (0.4 {nm}\\lt {h}{Au}≤slant 5 {nm}), there is both dewetting and Au0.8Si0.2 phase formation. The size and density of the Au0.8Si0.2 clusters are directly related to h Au. When cooling down to room temperature, the clusters decompose and reject the Si at the Au/Si substrate interface. (III) For a large thickness ({h}{{Au}}\\gt 5 {nm}), only dewetting takes place, without forming AuSi clusters. In this regime, the dewetting is kinetically controlled by the self-diffusion of Au (activation energy ∼0.43 eV) without evidence of an Si-alloying effect. As a practical consequence, when relying solely on the homogeneous dewetting of Au/Si(111) to form the Au0.8Si0.2 catalysts (without a supply of Si atoms from vapor), regime II should be used to obtain good size and density control. In the second part of the paper, a process for ordering the catalysts using focused ion beam-(FIB) assisted dewetting (heterogeneous dewetting) is developed. We show that no matter what the FIB milling conditions and the Au nominal thickness are, dewetting is promoted by ion beam irradiation and is accompanied by the formation of Au0.8Si0.2 droplets. The droplets preferentially form on the patterned areas, while in similar annealing conditions, they do not form on the unpatterned areas. This behavior is attributed to the larger Au-Si interdiffusion in the patterned areas, which results from the Si amorphization induced by the FIB. A systematic analysis of the position of the nanodroplets shows their preferential nucleation inside the patterns, while thicker platelets of almost pure Au are observed between the patterns. The evolutions of the size homogeneity and the occupancy rate of the patterns are quantified as a function of the FIB dose and annealing temperature. Nice arrays of perfectly ordered AuSi catalysts are obtained after optimizing the FIB and dewetting conditions.

  10. Gold Apes Hydrogen. The Structure and Bonding in the Planar B7Au2- and B7Au2 Clusters

    SciTech Connect

    Zhai, Hua JIN.; Wang, Lai S.; Zubarev, Dmitry Y.; Boldyrev, Alexander I.

    2006-02-09

    We produced the B7Au2- mixed cluster and studied its electronic structure and chemical bonding using photoelectron spectroscopy and ab initio calculations. The photoelectron spectra of B7Au2- were observed to be relatively simple with vibrational resolution, in contrast to the complicated spectra observed for pure B7-, which had contributions from three isomers (Alexandrova et al., J. Phys. Chem. A, 2004, 108, 3509). Theoretical calculations show that B7Au2- possesses an extremely stable planar structure, identical to that of B7H2-, demonstrating that Au mimics H in its bonding to boron, analogous to the Au-Si bonding. The ground state structure of B7Au2- (B7H2-) can be viewed as adding two Au (H) atoms to the terminal B atoms of a higher-lying planar isomer of B7-. The bonding and stability in the planar B7Au2- (B7H2-) clusters are elucidated on the basis of the strong covalent B-Au (H) bonding and the concepts of aromaticity/antiaromaticity in these systems.

  11. Evolution of the differential transverse momentum correlation function with centrality in Au + Au collisions at s=200 GeV

    NASA Astrophysics Data System (ADS)

    STAR Collaboration; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anderson, B. D.; Anson, C. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Beavis, D. R.; Behera, N. K.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Brovko, S. G.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Calderón de La Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Davila Leyva, A.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Derevschikov, A. A.; Derradi de Souza, R.; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Estienne, M.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Geurts, F.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O. G.; Grosnick, D.; Guertin, S. M.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Hofman, D. J.; Huang, B.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jena, C.; Jin, F.; Joseph, J.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Kizka, V.; Knospe, A. G.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Lukashov, E. V.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nayak, T. K.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pei, H.; Peitzmann, T.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Raniwala, R.; Raniwala, S.; Redwine, R.; Reed, R.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Solanki, D.; Sorensen, P.; Souza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Steadman, S. G.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C.; Wieman, H.; Wissink, S. W.; Witt, R.; Witzke, W.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, J. B.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, W.; Zhu, X.; Zhu, Y. H.; Zoulkarneev, R.; Zoulkarneeva, Y.

    2011-10-01

    We present first measurements of the evolution of the differential transverse momentum correlation function, C, with collision centrality in Au + Au interactions at s=200 GeV. This observable exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of C with increasing centrality to estimate the ratio of the shear viscosity to entropy density, η/s, of the matter formed in central Au + Au interactions. We obtain an upper limit estimate of η/s that suggests that the produced medium has a small viscosity per unit entropy.

  12. Structure and stability of borohydride on Au(111) and Au3M(111) (M = Cr, Mn, Fe, Co, Ni) surfaces.

    PubMed

    Arevalo, Ryan Lacdao; Escaño, Mary Clare Sison; Wang, Andrew Yu-Sheng; Kasai, Hideaki

    2013-01-21

    We study the adsorption of borohydride on Au and Au-based alloys (Au(3)M with M = Cr, Mn, Fe, Co, and Ni) using first-principles calculations based on spin-polarized density functional theory. Favorable molecular adsorption and greater adsorption stability compared to pure Au are achieved on Au(3)M alloys. For these alloys, there is an emergence of unoccupied states in the surface d band around the Fermi level with respect to the fully occupied d band of pure Au. Thus, the derived antibonding state of the sp-d interaction is upshifted and becomes unoccupied compared to pure Au. The B-H bond elongation of the adsorbed borohydride on these alloy surfaces points to the role of surface-parallel (d(xy) and d(x(2)-y(2)) states) components of the d-band of the alloying metal M, most pronouncedly in the cases of M = Co or Ni. On the alloy surfaces, B binds directly with the alloying metal, unlike in the case of pure Au where the surface bonding is through the H atoms. These results pose relevant insights into the design of Au-based anode catalysts for the direct borohydride fuel cell. PMID:23168688

  13. Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Gaudichet, L; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van der Kolk, N; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2006-09-29

    We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur. PMID:17026027

  14. High transverse momentum {eta} meson production in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Adler, S. S.; Aronson, S. H.; Chujo, T.; David, G.; Desmond, E. J.; Drees, K. A.; Ewell, L.; Franz, A.; Guryn, W.; Haggerty, J. S.; Harvey, M.; Johnson, B. M.; Kistenev, E.; Kroon, P. J.; Makdisi, Y. I.; Mioduszewski, S.; Mitchell, J. T.; Morrison, D. P.; O'Brien, E.; Pinkenburg, C.

    2007-02-15

    Inclusive transverse momentum spectra of {eta} mesons in the range p{sub T}{approx_equal}2-12 GeV/c have been measured at midrapidity (|{eta}|<0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. The {eta} mesons are reconstructed through their {eta}{yields}{gamma} {gamma} channel for the three colliding systems as well as through the {eta}{yields}{pi}{sup 0}{pi}{sup +}{pi}{sup -} decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R{sub dAu}(p{sub T}){approx_equal}1.0-1.1, suggests at most only modest p{sub T} broadening (''Cronin enhancement''). In central Au+Au reactions, the {eta} yields are significantly suppressed, with R{sub AuAu}(p{sub T}){approx_equal}0.2. The ratio of {eta} to {pi}{sup 0} yields is approximately constant as a function of p{sub T} for the three colliding systems in agreement with the high-p{sub T} world average of R{sub {eta}/{pi}{sup 0}}{approx_equal}0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies ({radical}(s{sub NN}){approx_equal}3-1800 GeV) as well as, for high scaled momentum x{sub p}, in e{sup +}e{sup -} annihilations at {radical}(s)=91.2 GeV. These results are consistent with a scenario where high-p{sub T} {eta} production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons ({pi}{sup 0},{eta}) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.

  15. Mixed Valent Gold Oxides: Syntheses, Structures, and Properties of Rb 5Au 3O 2, Rb 7Au 5O 2, and Cs 7Au 5O 2

    NASA Astrophysics Data System (ADS)

    Mudring, Anja-Verena; Nuss, Jürgen; Wedig, Ulrich; Jansen, Martin

    2000-11-01

    The title compounds Rb5Au3O2, Rb7Au5O2, and Cs7Au5O2 are the first examples of mixed valent phases containing gold in the oxidation states +1 and -1. Their crystal structures (Rb5Au3O2, Pbam, a=736.4(1) pm, b=1430.8(2) pm, c=567.9(1) pm, Z=2, R(F)=0.053, 647 reflections; Rb7Au5O2, Immm, a=567.1(2) pm, b=930.1(1) pm, C=1659.4(3) pm, Z=2, R(F)=0.066, 409 reflections; Cs7Au5O2, Immm, a=599.4(1) pm, b=960.6(3) pm, c=1720.8(12) pm, Z=2, R(F)=0.039, 386 reflections) are characterized by the combination of distinctive structural features of gold(I) oxides and aurides: for Au(+1) a typical linear coordination by oxygen is found and the surroundings of Au(-1) bear a close resemblance to the binary 1:1 aurides. In consequence the overall structures of Rb5Au3O2 and M7Au5O2 can be described as intergrowths of M3AuO2 and MAu (M=Rb, Cs), constituting members of a homologous series [MAu]n[M3AuO2] with n=2 and 4, respectively. The crystal chemical evidence for the valence states assumed, also confirmed by Mößbauer spectroscopy, is supported by various band structure calculations (Hartee-Fock and density functional) clearly indicating the coexistence of two different oxidation states. The compounds have been synthesized by reacting binary aurides MAu and alkali monoxides M2O (M=Rb, Cs) with elemental gold in the required stochiometric amounts. Hereby, a further astonishing parallel to the chemistry of halogens is revealed. Like these, gold disproportionates upon interaction with bases.

  16. CO oxidation on h-BN supported Au atom

    SciTech Connect

    Gao Min; Lyalin, Andrey; Taketsugu, Tetsuya

    2013-01-21

    The mechanism of CO oxidation by O{sub 2} on Au atoms supported on the pristine and defected hexagonal boron nitride (h-BN) surface has been studied theoretically using density functional theory. It is found that O{sub 2} binds stronger than CO on an Au atom supported on the defect free h-BN surface and h-BN surface with nitrogen vacancy (V{sub N}-h-BN), but weaker than CO on a free Au atom or Au trapped by a boron vacancy (V{sub B}-h-BN). The excess of the positive or negative charge on Au can considerably change its catalytic properties and enhance activation of the adsorbed O{sub 2}. Coadsorption of CO and O{sub 2} on Au, Au/V{sub N}-h-BN, and Au/V{sub B}-h-BN results in additional charge transfer to O{sub 2}. Various pathways of the CO oxidation reaction by molecular oxygen are studied. We found two different pathways for CO oxidation: a two-step pathway where two CO{sub 2} molecules are formed independently, and a self-promotion pathway where oxidation of the first CO molecule is promoted by the second CO molecule. Interaction of Au with the defect-free and defected h-BN surface considerably affects the CO oxidation reaction pathways and barriers. Therefore, Au supported on the h-BN surface (pristine or defected) cannot be considered as pseudo-free atom and support effects have to be taken into account, even when the interaction of Au with the support is weak.

  17. Registration of ‘AU-1101’ peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AU-1101’ (Reg. No. CV-xxx, PI 661498) is a large-seeded virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) with high yield and medium maturity, uniform pod size and shape, high grade, superior shelling characters, low oil content, normal oleic acid content, and good flavor. AU-...

  18. Microstructural evolution of eutectic Au-Sn solder joints

    SciTech Connect

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  19. Experimental Evidence for Electron Channeling in Fe/ Au (100) Superlattices

    SciTech Connect

    Dekadjevi, D. T.; Ryan, P. A.; Hickey, B. J.; Fulthorpe, B. D.; Tanner, B. K.

    2001-06-18

    We present transport and structural data from epitaxial (100) and (111) Au/Fe superlattices grown by molecular beam epitaxy. From their analysis, we conclude that an electron channeling mechanism, due to strong specular reflection of the minority spin carrier at the Au/Fe interfaces, is responsible for the high conductivity in the (100) superlattices.

  20. Atomistic modeling of Au-Ag nanoparticle formation

    SciTech Connect

    Negreiros, F. R.; Soares, E. A.; Carvalho, V. E. de; Bozzolo, G.

    2007-12-15

    Atomistic modeling of the formation process of Au-Ag nanoparticles is performed using the Bozzolo-Ferrante-Smith method for alloys for the energetic. Silver segregation to the surface, surface structure and orientation, and weak Au-Ag interactions are identified as the main features driving the formation process.

  1. Development of amperometric lysine biosensors based on Au nanoparticles/multiwalled carbon nanotubes/polymers modified Au electrodes.

    PubMed

    Chauhan, Nidhi; Singh, Anamika; Narang, Jagriti; Dahiya, Swati; Pundir, C S

    2012-11-01

    The construction of two amperometric l-lysine biosensors is described in this study. The construction comprises the covalent immobilization of lysine oxidase (LOx) onto nanocomposite composed of gold nanoparticles (AuNPs) and carboxylated multiwalled carbon nanotubes (c-MWCNT), decorated on (i) polyaniline (PANI) and (ii) poly 1,2 diaminobenzene (DAB), electrodeposited on Au electrodes. The biosensors were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and electrochemical impedance spectroscopy (EIS) studies. The optimum response (current) was observed within 2 s at pH 7.0 and 25 °C for LOx/AuNPs/c-MWCNT/PANI/Au, and 4 s at pH 7.0 and 30 °C for LOx/AuNPs/c-MWCNT/DAB/Au electrodes. There was a linear relationship between current and lysine concentration ranging from 5.0 to 600 μM for LOx/AuNPs/c-MWCNT/PANI/Au with a detection limit of 5.0 μM, and 20 to 600 μM for the LOx/AuNPs/c-MWCNT/DAB/Au electrode with a detection limit of 20 μM. The PANI modified electrode was in good agreement with the standard HPLC method, with a better correlation (r = 0.992) compared to the DAB modified electrode (r = 0.986). These observations revealed that the PANI modified Au electrode was better than the DAB modified electrode, and hence it was employed for the determination of lysine in milk, pharmaceutical tablets and sera. The PANI modified electrode showed a half life of 120 days, compared to that of 90 days for the DAB modified electrode, after their 100 uses, when stored at 4 °C. PMID:22986735

  2. Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-08-15

    We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions. PMID:12935009

  3. Evidence from d+Au Measurements for Final-State Suppression of High-pT Hadrons in Au+Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Badyal, S. K.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bezverkhny, B. I.; Bhardwaj, S.; Bhaskar, P.; Bhati, A. K.; Bichsel, H.; Billmeier, A.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Calderón de La Barca Sánchez, M.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Dong, X.; Draper, J. E.; Du, F.; Dubey, A. K.; Dunin, V. B.; Dunlop, J. C.; Dutta Majumdar, M. R.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Ganti, M. S.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Grachov, O.; Grigoriev, V.; Gronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S. M.; Gupta, A.; Gushin, E.; Gutierrez, T. D.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heinz, M.; Henry, T. W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Huang, S. L.; Humanic, T. J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Koetke, D. D.; Kollegger, T.; Konstantinov, A. S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; Levine, M. J.; Li, C.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Ludlam, T.; Lynn, D.; Ma, J.; Ma, Y. G.; Magestro, D.; Mahajan, S.; Mangotra, L. K.; Mahapatra, D. P.; Majka, R.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mironov, C.; Mishra, D.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Mora-Corral, M. J.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Nandi, B. K.; Nayak, S. K.; Nayak, T. K.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V.; Prindle, D.; Pruneau, C.; Putschke, J.; Rai, G.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Renault, G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shestermanov, K. E.; Shimanskii, S. S.; Singaraju, R. N.; Simon, F.; Skoro, G.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Šumbera, M.; Surrow, B.; Symons, T. J.; Szanto de Toledo, A.; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, A. H.; Thein, D.; Thomas, J. H.; Tikhomirov, V.; Tokarev, M.; Tonjes, M. B.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Trivedi, M. D.; Trofimov, V.; Tsai, O.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Vandermolen, A. M.; Vasiliev, A. N.; Vasiliev, M.; Vigdor, S. E.; Viyogi, Y. P.; Voloshin, S. A.; Waggoner, W.; Wang, F.; Wang, G.; Wang, X. L.; Wang, Z. M.; Ward, H.; Watson, J. W.; Wells, R.; Westfall, G. D.; Whitten, C.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Z.; Xu, Z. Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, H. Y.; Zhang, W. M.; Zhang, Z. P.; Żołnierczuk, P. A.; Zoulkarneev, R.; Zoulkarneeva, J.; Zubarev, A. N.

    2003-08-01

    We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high pT) in minimum bias and central d+Au collisions at (sNN)=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high pT previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

  4. Sputtering of Au induced by single Xe ion impacts

    SciTech Connect

    Birtcher, R. C.; Donnelly, S. E.

    1999-12-06

    Sputtering of Au thin films has been determined for Xe ions with energies between 50 and 600 keV. In-situ transmission electron microscopy was used to observe sputtered Au during deposition on a carbon foil near the specimen. Total reflection and transmission sputtering yields for a 62 nm thick Au thin film were determined by ex-situ measurement of the total amount of Au on the carbon foils. In situ observations show that individual Xe ions eject Au nanoparticles as large as 7 nm in diameter with an average diameter of approximately 3 nm. Particle emission correlates with crater formation due to single ion impacts. Nanoparticle emission contributes significantly to the total sputtering yield for Xe ions in this energy range in either reflection or transmission geometry.

  5. Identification of Au–S complexes on Au(100)

    DOE PAGESBeta

    Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; Yang, Hyun Jin; Kim, Yousoo; Thiel, P. A.

    2016-01-25

    In this study, using a combination of scanning tunneling microscopy and density functional theory (DFT) calculations, we have identified a set of related Au–S complexes that form on Au(100), when sulfur adsorbs and lifts the hexagonal surface reconstruction. The predominant complex is diamond-shaped with stoichiometry Au4S5. All of the complexes can be regarded as combinations of S–Au–S subunits. The complexes exist within, or at the edges of, p(2 × 2) sulfur islands that cover the unreconstructed Au regions, and are observed throughout the range of S coverage examined in this study, 0.009 to 0.12 monolayers. A qualitative model is developedmore » which incorporates competitive formation of complexes, Au rafts, and p(2 × 2) sulfur islands, as Au atoms are released by the surface structure transformation.« less

  6. Interpretation of the first data on central Au+Au collisions at

    SciTech Connect

    Jeon, Sangyong; Kapusta, Joseph

    2001-01-01

    We compare three semimicroscopic theories to the first data on particle production in central Au+Au collisions taken at RHIC by the PHOBOS Collaboration as well as to existing data on central Pb+Pb collisions taken at the SPS by the NA49 Collaboration. The Linear Extrapolation of Ultrarelativistic nucleon-nucleon Scattering to nucleus-nucleus collisions (LEXUS) represents the SPS data quite well but predicts too many particles at RHIC. The wounded nucleon model predicts too few particles at both the SPS and RHIC; the collective tube model predicts fewer particles still. This suggests a transition in the dynamics of particle production between s=17 and 56A GeV as one goes from the SPS to RHIC.

  7. Charge transport in single Au / alkanedithiol / Au junctions: coordination geometries and conformational degrees of freedom.

    PubMed

    Li, Chen; Pobelov, Ilya; Wandlowski, Thomas; Bagrets, Alexei; Arnold, Andreas; Evers, Ferdinand

    2008-01-01

    Recent STM molecular break-junction experiments have revealed multiple series of peaks in the conductance histograms of alkanedithiols. To resolve a current controversy, we present here an in-depth study of charge transport properties of Au|alkanedithiol|Au junctions. Conductance histograms extracted from our STM measurements unambiguously confirm features showing more than one set of junction configurations. On the basis of quantum chemistry calculations, we propose that certain combinations of different sulfur-gold couplings and trans/gauche conformations act as the driving agents. The present study may have implications for experimental methodology: whenever conductances of different junction conformations are not statistically independent, the conductance histogram technique can exhibit a single series only, even though a much larger abundance of microscopic realizations exists. PMID:18076172

  8. Pion-kaon femtoscopy in Au+Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Poniatowska, Katarzyna; STAR Collaboration

    2015-05-01

    In non-identical particle correlations, e.g. pion-kaon femtoscopy, one can obtain information about source size and asymmetry in emission processes of pions and kaons. Such asymmetry give us knowledge of which type of particles is emitted first/second and/or from which region of the source. The studies of non-identical particle femtoscopy for Beam Energy Scan energies give us the opportunity to study how the source size and asymmetry in particle emission depend on the initial conditions of the collision. It also allows one to examine these parameters in the vicinity of the theoretical critical point. In these proceedings, we present STAR results of pion-kaon femtoscopy at mid-rapidity in Au+Au collisions at \\sqrt{sNN} = 7.7, 19.6 and 39 GeV.

  9. Pion-kaon femtoscopy in Au+Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Poniatowska, Katarzyna

    2015-05-01

    Femtoscopy analysis allows us to extract information about the properties of particle emission source created after collision. From HBT of two correlated pions one can calculate source sizes; in addition, from the non-identical particle correlations, e.g. pion-kaon femtoscopy, one can obtain information not only about source sizes but the asymmetry in the emission processes of particles of different types as well. Such asymmetry gives knowledge of which kind of particles are emitted first/second and/or from which region of the source. The studies of non-identical particle femtoscopy for different collision energies gives us the opportunity to study how the source size and asymmetry in particle emission depend on the initial conditions of the collision. In these proceedings, we will present STAR results of pion-kaon femtoscopy at mid-rapidity in Au + Au collisions from the Beam Energy Scan program.

  10. 200 A GeV Au + Au collisions serve a nearly perfect quark-gluon liquid.

    PubMed

    Song, Huichao; Bass, Steffen A; Heinz, Ulrich; Hirano, Tetsufumi; Shen, Chun

    2011-05-13

    A new robust method to extract the specific shear viscosity (η/s)(QGP) of a quark-gluon plasma (QGP) at temperatures T(c) < T ≲ 2T(c) from the centrality dependence of the eccentricity-scaled elliptic flow v2/ε measured in ultrarelativistic heavy-ion collisions is presented. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find for 200 A GeV Au + Au collisions that v2/ε is a universal function of multiplicity density (1/S)(dN(ch)/dy) that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity ε. Comparing with measurements we find 1<4π(η/s)(QGP) < 2.5 where the uncertainty range is dominated by model uncertainties for the values of ε used to normalize the measured v2. PMID:21668145

  11. Azimuthal Anisotropy in U +U and Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, W.; Li, Y.; Li, C.; Li, Z. M.; Li, X.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, R.; Ma, Y. G.; Ma, G. L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, N.; Xu, Z.; Xu, Q. H.; Xu, H.; Yang, Y.; Yang, Y.; Yang, C.; Yang, S.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, J. B.; Zhang, J.; Zhang, Z.; Zhang, S.; Zhang, Y.; Zhang, J. L.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-11-01

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2 } and v2{4 }, for charged hadrons from U +U collisions at √{sNN }=193 GeV and Au +Au collisions at √{sNN}=200 GeV . Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2 } on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U +U collisions. We also show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  12. Antimatter production in central Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Yan, Yu-Liang; Li, De-Sheng; Zhou, Dai-Mei; Wang, Mei-Juan; Dong, Bao-Guo; Sa, Ben-Hao

    2012-11-01

    We have used the dynamically constrained phase space coalescence model to investigate the production of light nuclei (antinuclei) based on the 1.134×107 hadronic final states generated by the parton and hadron cascade (PACIAE) model for the 0-5% most central Au+Au collisions at sNN=200 GeV with |y|<1 and pT<5 acceptances. The STAR data of Λ¯3H¯, Λ3H, 3He¯, and 3He yields and ratios are well reproduced by the corresponding PACIAE results. The transverse momentum distribution of 3He¯ (3He) and Λ¯3H¯ (Λ3H) is also given. It turned out that the transverse momentum distribution of light nuclei is close to that of the corresponding antinuclei.

  13. Azimuthal Angle Dependence of HBT Radii in Au+Au Collisions at RHIC-PHENIX

    NASA Astrophysics Data System (ADS)

    Niida, Takafumi

    Measurement of Hanbury-Brown and Twiss (HBT) interferometry with respect to the event plane have been performed in Au+Au collisions at √{sNN} = 200 GeV at PHENIX, which is a unique tool to study the spatial extent of the created matter at final state in heavy ion collisions and the detailed picture of the space-time evolution from the initial state to the final state. The Gaussian source radii was measured for charged pions and kaons with respect to 2nd-order event plane. There was a difference in final eccentricity between both species, which may imply the different freeze-out mechanism by the particle species. The pion source radii was also measured relative to 3rd-order event plane, and the azimuthal angle dependence of the radii was observed, which qualitatively agrees with the recent hydrodynamic calculation and the oscillation may be driven from the triangular flow.

  14. Dynamic aperture calculation for the RHIC 2010 100 GeV Au-Au run lattices

    SciTech Connect

    Luo, Y.; Brown, K.; Fischer, W.; Ptitsyn, V.; Roser, T.; Schoefer, V.; Tepikian, S.; Trbojevic, D.

    2010-08-01

    In this note we summarize the dynamic aperture calculation with the 2010 RHIC 100 GeV Au-Au run lattices. This study was initiated to understand the observed large beam decay in the Yellow ring after rf re-bucketing in the beginning of this run. The off-line linear lattice models and the interaction region non-linearity models are used. The large beam decay in the Yellow ring after re-bucketing was eventually eliminated by lowering the Yellow tunes to 0.21 from 0.235 with {beta}* = 0.7m lattice. In this note we only focus on the numeric simulation instead of the beam experiments.

  15. Midrapidity φ production in Au+Au collisions at (sNN)=130 GeV

    NASA Astrophysics Data System (ADS)

    Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bichsel, H.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Boucham, A.; Brandin, A.; Cadman, R. V.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chattopadhyay, S.; Chen, M. L.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Demello, M.; Deng, W. S.; Derevschikov, A. A.; Didenko, L.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grabski, J.; Grachov, O.; Greiner, D.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heffner, M.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Igo, G.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E.; Kaneta, M.; Kaplan, M.; Keane, D.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Konstantinov, A. S.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamas-Valverde, J.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lecompte, T.; Lednický, R.; Leontiev, V. M.; Levine, M. J.; Li, Q.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Ljubicic, T.; Llope, W. J.; Locurto, G.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lynn, D.; Majka, R.; Margetis, S.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mitchell, J.; Moiseenko, V. A.; Moltz, D.; Moore, C. F.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Mutchler, G. S.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Platner, E.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Radomski, S.; Rai, G.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Russ, D.; Rykov, V.; Sakrejda, I.; Sandweiss, J.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schüttauf, A.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shestermanov, K. E.; Shimanskii, S. S.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Snellings, R.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Šumbera, M.; Symons, T. J.; Szanto de Toledo, A.; Szarwas, P.; Takahashi, J.; Tang, A. H.; Thomas, J. H.; Tikhomirov, V.; Trainor, T. A.; Trentalange, S.; Tokarev, M.; Tonjes, M. B.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; van Buren, G.; Vandermolen, A. M.; Vanyashin, A.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Voloshin, S. A.; Wang, F.; Ward, H.; Watson, J. W.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitten, C.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yokosawa, A.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, W. M.; Zoulkarneev, R.; Zubarev, A. N.

    2002-04-01

    We present the first measurement of midrapidity vector meson φ production in Au+Au collisions at RHIC ((sNN)=130 GeV) from the STAR detector. For the 11% highest multiplicity collisions, the slope parameter from an exponential fit to the transverse mass distribution is T=379+/-50(stat)+/-45(syst) MeV, the yield dN/dy=5.73+/-0.37(stat)+/-0.69(syst) per event, and the ratio Nφ/Nh- is found to be 0.021+/-0.001(stat)+/-0.004(syst). The measured ratio Nφ/Nh- and T for the φ meson at midrapidity do not change for the selected multiplicity bins.

  16. Net charge fluctuations in Au+Au collisions at (sNN )=130 GeV

    NASA Astrophysics Data System (ADS)

    Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Badyal, S. K.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bezverkhny, B. I.; Bhardwaj, S.; Bhaskar, P.; Bhati, A. K.; Bichsel, H.; Billmeier, A.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Dong, X.; Draper, J. E.; Du, F.; Dubey, A. K.; Dunin, V. B.; Dunlop, J. C.; Dutta Majumdar, M. R.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Ganti, M. S.; Gutierrez, T. D.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Grachov, O.; Grigoriev, V.; Gronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S. M.; Gupta, A.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heinz, M.; Henry, T. W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Huang, S. L.; Humanic, T. J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Koetke, D. D.; Kolleger, T.; Konstantinov, A. S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; Levine, M. J.; Li, C.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Ludlam, T.; Lynn, D.; Ma, J.; Ma, Y. G.; Magestro, D.; Mahajan, S.; Mangotra, L. K.; Mahapatra, D. P.; Majka, R.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mironov, C.; Mishra, D.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Mora-Corral, M. J.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Nandi, B. K.; Nayak, S. K.; Nayak, T. K.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V.; Prindle, D.; Pruneau, C.; Putschke, J.; Rai, G.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ravel, O.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Renault, G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L. J.; Rykov, V.; Sahoo, R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shestermanov, K. E.; Shimanskii, S. S.; Singaraju, R. N.; Simon, F.; Skoro, G.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Šumbera, M.; Surrow, B.; Symons, T. J.; Szanto de Toledo, A.; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, A. H.; Thein, D.; Thomas, J. H.; Tikhomirov, V.; Tokarev, M.; Tonjes, M. B.; Trentalange, S.; Tribble, R. E.; Trivedi, M. D.; Trofimov, V.; Tsai, O.; Ullrich, T.; Underwood, D. G.; van Buren, G.; Vandermolen, A. M.; Vasiliev, A. N.; Vasiliev, M.; Vigdor, S. E.; Viyogi, Y. P.; Voloshin, S. A.; Waggoner, W.; Wang, F.; Wang, G.; Wang, X. L.; Wang, Z. M.; Ward, H.; Watson, J. W.; Wells, R.; Westfall, G. D.; Whitten, C.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Z.; Xu, Z. Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, H. Y.; Zhang, W. M.; Zhang, Z. P.; Zołnierczuk, P. A.; Zoulkarneev, R.; Zoulkarneeva, J.; Zubarev, A. N.

    2003-10-01

    We present the results of charged particle fluctuations measurements in Au+Au collisions at (sNN )=130 GeV using the STAR detector. Dynamical fluctuations measurements are presented for inclusive charged particle multiplicities as well as for identified charged pions, kaons, and protons. The net charge dynamical fluctuations are found to be large and negative providing clear evidence that positive and negative charged particle production is correlated within the pseudorapidity range investigated. Correlations are smaller than expected based on model-dependent predictions for a resonance gas or a quark-gluon gas which undergoes fast hadronization and freeze-out. Qualitative agreement is found with comparable scaled p+p measurements and a heavy ion jet interaction generation model calculation based on independent particle collisions, although a small deviation from the 1/N scaling dependence expected from this model is observed.

  17. STAR physics program and technical challenges with the RHIC energy scan with Au + Au collisions

    NASA Astrophysics Data System (ADS)

    Odyniec, G.; STAR Collaboration

    2008-10-01

    The future STAR physics program includes an Au + Au energy scan extending to low \\sqrt{s_{NN}} . Among other things, this energy scan will provide a unique opportunity to search for the phase boundary between quark-gluon plasma (QGP) and hadronic gas (HG), and a key landmark, a possible critical point, in the QCD phase diagram. Due to its large uniform acceptance and (with the addition of the time-of-flight detector) excellent particle identification capabilities, by the time of Run 10 (in 2010) STAR will be uniquely positioned to cover this physics in unprecedented depth and detail, as well as other novel physics possibilities. Running at very low energies poses major new challenges for accelerator experts at RHIC and for physicists preparing for data taking. We report on the status of STAR preparation for Run 10.

  18. Local structure of disordered Au-Cu and Au-Ag alloys

    NASA Astrophysics Data System (ADS)

    Frenkel, A. I.; Machavariani, V. Sh.; Rubshtein, A.; Rosenberg, Yu.; Voronel, A.; Stern, E. A.

    2000-10-01

    X-ray-absorption fine structure (XAFS) and x-ray-diffraction (XRD) measurements of disordered alloys AuxCu1-x and Au0.5Ag0.5 prepared by melt spinning were performed. In the Au0.5Ag0.5 alloy, no significant local deviations of the atoms from the average fcc lattice were detected while in AuxCu1-x alloys, significant deviations of atoms from the average fcc lattice were found. Mean-square vibrations of the Cu-Cu distances revealed by the XAFS in AuxCu1-x alloys indicate the weakening of contact between Cu atoms in the dilute limit. Our computer simulation for AuxCu1-x clusters of 105 atoms reproduces the main features of both the XAFS and XRD data.

  19. A comparative study of the Au + H2, Au+ + H2, and Au- + H2 systems: Potential energy surfaces and dynamics of reactive collisions

    NASA Astrophysics Data System (ADS)

    Dorta-Urra, Anaís; Zanchet, Alexandre; Roncero, Octavio; Aguado, Alfredo

    2015-04-01

    In order to study the Au- + H2 collision, a new global potential energy surface (PES) describing the ground electronic state of AuH 2- system is developed and compared with the PESs of the neutral [Zanchet et al., J. Chem. Phys. 132, 034301 (2010)] and cationic systems [Anaís et al., J. Chem. Phys. 135, 091102 (2011)]. We found that Au- - H2 presents a H-Au-H insertion minimum attributed to the stabilization of the LUMO 3b2 orbital, which can be considered as the preamble of the chemisorption well appearing in larger gold clusters. While the LUMO orbital is stabilized, the HOMO 6a1 is destabilized, creating a barrier at the geometry where the energy orbitals' curves are crossing. In the anion, this HOMO is doubly occupied, while in the neutral system is half-filled and completely empty in the cation, explaining the gradual disappearance of the well and the barrier as the number of electrons decreases. The cation presents a well in the entrance channel partially explained by electrostatic interactions. The three systems' reactions are highly endothermic, by 1.66, 2.79, and 3.23 eV for AuH, AuH+, and AuH- products, respectively. The reaction dynamics is studied using quasi-classical trajectory method for the three systems. The one corresponding to the anionic system is new in this work. Collision energies between 1.00 and 8.00 eV, measured for the cation, are in good agreement with the simulated cross section for the AuH+. It was also found that the total fragmentation, in three atoms, competes becoming dominant at sufficiently high energy. Here, we study the competition between the two different reaction pathways for the anionic, cationic, and neutral species, explaining the differences using a simple model based on the topology of the potential energy surfaces.

  20. From the ternary Eu(Au/In)2 and EuAu4(Au/In)2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu5Au16(Au/In)6 structure

    SciTech Connect

    Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

    2015-08-13

    The ternary Eu(Au/In)2 (EuAu0.46In1.54(2)) (I), EuAu4(Au/In)2 (EuAu4+xIn2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-type (tI14; I4/mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu2–“EuAu4In2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu4(Au/In)2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu5In” and “EuAu4In2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.

  1. Biosynthesis of Au, Ag and Au-Ag nanoparticles using edible mushroom extract

    NASA Astrophysics Data System (ADS)

    Philip, Daizy

    2009-07-01

    Integration of green chemistry principles to nanotechnology is one of the key issues in nanoscience research. There is growing need to develop environmentally benign metal nanoparticle synthesis process that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on extracellular synthesis method for the preparation of Au, Ag and Au-Ag nanoparticles in water, using the extract of Volvariella volvacea, a naturally occurring edible mushroom, as reducing and protecting agents. Gold nanoparticles of different sizes (20-150 nm) and shapes from triangular nanoprisms to nearly spherical and hexagonal are obtained by this novel method. The size and shape of gold nanoparticles are also found to depend on temperature of the extract. The silver nanoparticles are spherical with size ˜15 nm. There is increased productivity of nanoparticles as shown by sharp and intense surface plasmon resonance bands for the nanoparticles prepared using an excess of the extract. The Au-Ag nanoparticles prepared by co-reduction has only one plasmon band due to alloying of the constituents. All the synthesized nanoparticles are found to be photoluminescent and are highly crystalline as shown by SAED and XRD patterns with fcc phase oriented along the (1 1 1) plane. FTIR measurements were carried out to identify the possible biomolecules responsible for capping and efficient stabilization of the nanoparticles. It is found that Au nanoparticles are bound to proteins through free amino groups and silver nanoparticles through the carboxylate group of the amino acid residues. The position and intensity of the emission band is found to depend on composition of the nanoparticles indicating the possible use in therapeutic applications.

  2. Electronic and resonance Raman spectra of [Au2(CS3)2]2-. Spectroscopic properties of a "short" Au(I)-Au(I) bond.

    PubMed

    Cheng, E C; Leung, K H; Miskowski, V M; Yam, V W; Phillips, D L

    The anion [Au2(CS3)2]2- has an unusually short Au-Au distance (2.80 A) for a binuclear Au(I) complex. We report detailed Raman studies of the nBu4N+ salt of this complex, including FT-Raman of the solid and UV/vis resonance Raman of dimethyl sulfoxide solutions. All five totally symmetric vibrations of the anion have been located and assigned. A band at delta nu = 125 cm-1 is assigned to nu (Au2). The visible-region electronic absorption bands (384 (epsilon 30,680) and 472 nm (epsilon 610 M-1 cm-1)) are attributable to CS3(2-) localized transitions, as confirmed by the dominance of nu sym(C-Sexo) (delta nu = 951 cm-1) in RR spectra measured in this region. An absorption band at 314 nm (22,250 M-1 cm-1) is assigned as the metal-metal 1(d sigma*-->p sigma) transition, largely because nu sym(C-Sexo) is not strongly enhanced in RR involving this band. Observation of the expected strong resonance enhancement of nu (Au2) was precluded as a result of masking by intense solvent Rayleigh scattering in the UV. PMID:11196834

  3. Stream dynamics between 1 AU and 2 AU: A detailed comparison of observations and theory

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Pizzo, V.; Lazarus, A.; Gazis, P. R.

    1984-01-01

    A radial alignment of three solar wind stream structures observed by IMP-7 and -8 (at 1.0 AU) and Voyager 1 and 2 (in the range 1.4 to 1.8 AU) in late 1977 is presented. It is demonstrated that several important aspects of the observed dynamical evolution can be both qualitatively and quantitatively described with a single-fluid 2-D MHD numerical model of quasi-steady corotating flow, including accurate prediction of: (1) the formation of a corotating shock pair at 1.75 AU in the case of a simple, quasi-steady stream; (2) the coalescence of the thermodynamic and magnetic structures associated with the compression regions of two neighboring, interacting, corotating streams; and (3) the dynamical destruction of a small (i.e., low velocity-amplitude, short spatial-scale) stream by its overtaking of a slower moving, high-density region associated with a preceding transient flow. The evolution of these flow systems is discussed in terms of the concepts of filtering and entrainment.

  4. Stream dynamics between 1 AU and 2 AU - A comparison of observations and theory

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Pizzo, V.; Lazarus, A.; Gazis, P.

    1985-01-01

    A radial alignment of three solar wind stream structures observed by IMP-7 and -8 (at 1.0 AU) and Voyager 1 and 2 (in the range 1.4 to 1.8 AU) in late 1977 is presented. It is demonstrated that several important aspects of the observed dynamical evolution can be both qualitatively and quantitatively described with a single-fluid 2-D MHD numerical model of quasi-steady corotating flow, including accurate prediction of: (1) the formation of a corotating shock pair at 1.75 AU in the case of a simple, quasi-steady stream; (2) the coalescence of the thermodynamic and magnetic structures associated with the compression regions of two neighboring, interacting, corotating streams; and (3) the dynamical destruction of a small (i.e., low velocity-amplitude, short spatial-scale) stream by its overtaking of a slower moving, high-density region associated with a preceding transient flow. The evolution of these flow systems is discussed in terms of the concepts of filtering and entrainment.

  5. Neutral pion production in Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bnzarov, I.; Bombara, M.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bruna, E.; Bueltmann, S.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; Silva, L. C. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gaillard, L.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Konzer, J.; Kopytine, M.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Krus, M.; Kuhn, C.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, N.; Li, Y.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shi, X.-H.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Nieuwenhuizen, G. Van; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xie, W.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zhu, X.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zuo, J. X.

    2009-10-01

    The results of midrapidity (0Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured either by the STAR Barrel Electro-Magnetic Calorimeter or by the Time Projection Chamber via tracking of conversion electron-positron pairs. Our measurements are compared to previously published π± and π0 results. The nuclear modification factors RCP and RAA of π0 are also presented as a function of pT. In the most central Au+Au collisions, the binary collision scaled π0 yield at high pT is suppressed by a factor of about 5 compared to the expectation from the yield of p+p collisions. Such a large suppression is in agreement with previous observations for light quark mesons and is consistent with the scenario that partons suffer considerable energy loss in the dense medium formed in central nucleus-nucleus collisions at the Relativistic Heavy Ion Collider.

  6. Temperature measurement of fragment emitting systems in Au+Au 35 MeV/nucleon collisions

    NASA Astrophysics Data System (ADS)

    Milazzo, P. M.; Vannini, G.; Azzano, M.; Fontana, D.; Margagliotti, G. V.; Mastinu, P. F.; Rui, R.; Tonetto, F.; Colonna, N.; Botvina, A.; Bruno, M.; D'agostino, M.; Fiandri, M. L.; Gramegna, F.; Iori, I.; Moroni, A.; Dinius, J. D.; Gaff, S.; Gelbke, C. K.; Glasmacher, T.; Huang, M. J.; Kunde, G. J.; Lynch, W. G.; Martin, L.; Montoya, C. P.; Xi, H.

    1998-08-01

    We report on the results of experiments performed to investigate the Au+Au 35 MeV/nucleon reaction. The reaction products generated in the disassembly of the unique source formed in central collisions and those coming from the decay of the quasiprojectile in peripheral and midperipheral ones (five different impact parameters) were identified through a careful data selection based on the study of energy and angular distributions. The excitation energies of the fragment sources have been extracted through a calorimetric method and by means of a comparison with model calculations. The nuclear temperatures of these decaying systems have been measured from the relative isotopic abundances and, also for central collisions, from the relative populations of excited states. The temperatures of the quasiprojectile disassembling systems are slowly increasing going towards smaller impact parameter. The relationship between temperature and excitation energy seems to be almost independent of the characteristics of the emitting source. The extracted caloric curve shows a slow monotonic increase with increasing excitation energy. A comparison with data derived from Au fragmentation at much higher incident energies is discussed.

  7. {phi} meson production in Au + Au and p + p collisions at {radical}s{sub NN}=200 GeV

    SciTech Connect

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj, S.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll, J.; Castillo, J.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Ganti, M.S.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grebenyuk, O.; Gronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; Gutierrez, T.D.; Hallman, T.J.; Hamed, A.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang, S.L.; Hughes, E.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaplan, M.; Keane, D.; Khodyrev; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Kopytine, S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Kravstov, V.I.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; et al.

    2004-06-01

    We report the STAR measurement of {psi} meson production in Au + Au and p + p collisions at {radical}s{sub NN} = 200 GeV. Using the event mixing technique, the {psi} spectra and yields are obtained at midrapidity for five centrality bins in Au+Au collisions and for non-singly-diffractive p+p collisions. It is found that the {psi} transverse momentum distributions from Au+Au collisions are better fitted with a single-exponential while the p+p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that {psi} production in central Au+Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions (). The systematics of versus centrality and the constant {psi}/K{sup -} ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for {psi} production.

  8. Etude de L'energie Moyenne de Creation de Paire dans les Detecteurs de Particules AU Silicium Amorphe Hydrogene

    NASA Astrophysics Data System (ADS)

    Dubeau, Jacques

    Ce travail porte sur la mesure et le calcul de l'energie de creation d'une paire electron-trou, epsilon_{p}, par une particule ionisante dans des detecteurs en couches minces au a-Si:H. Cette etude fut realisee a l'aide de dispositifs specialement concus et qui sont de deux types. Le premier emprunte au domaine des cellules photovoltaiques des structures p/i/n qui ont des couches dopees de ~30 nm mais dont on augmente l'epaisseur de la couche sensible, la couche i, a 3 ou 4 mum. Ces dispositifs peuvent etre polarises en inverse jusqu'a 20 V/ mum. Le second type consiste aussi en des structures p/i/n qui cette fois sont adaptees specialement aux applications de detection. Ces nouveaux dispositifs possedent une couche p de plus de 300 nm qui attenue l'injection d'electrons lors de l'application de la tension inverse, prevenant ainsi le claquage premature et permettant l'application de tensions de plus de 60 V/mum. De plus, ils ont une couche i faisant de 4 a 18 mu m. Nous avons soumis ces dispositifs a des protons et des particules alpha couvrant un domaine de dE/dx de 7.5 a 300 keV/mum. On met ainsi en evidence deux regimes d'operations. Premierement, lorsqu'on utilise des particules ayant des dE/dx eleves, a des incidences normales a la surface du detecteur et que la tension appliquee aux bornes du dispositif est faible, le signal est fortement attenue par des effets plasmas. Deuxiemement, a de fortes tensions pour des particules a incidences obliques et dE/dx faibles, l'amplitude du signal est proportionnelle a l'energie deposee dans la zone i du detecteur. Cependant, ce signal n'est pas sature et il semble augmenter avec la tension au-dela de la tension de claquage. De plus, on demontre qu'a des tensions intermediaires le signal est plus eleve si la tension est pulsee et si le temps d'integration de l'electronique est long (~ 20mus). En extrapolant l'amplitude du signal a une tension infinie nous obtenons une valeur de epsilon _{p} affranchie de tout effet de recombinaison et egale a 3.8 +/- 0.5 eV. Cette valeur, tres proche de celle du silicium cristallin, est surprenante compte tenu du gap de mobilite tres large du materiau amorphe, 1.7 eV, par comparaison a la bande interdite du materiau cristallin, 1.12 eV. En effet, le modele de Klein, qui reproduit les valeurs de epsilon_{p} dans un grand nombre de semiconducteurs cristallins, predit une energie de creation de paire de 5.8 eV dans le a-Si:H. Cependant, notre valeur experimentale est compatible avec le resultat d'un calcul Monte Carlo que nous avons effectue et au cours duquel nous simulons, en detail, la thermatisation des porteurs dans les bandes de valence et de conduction par processus Auger et par generation de phonons optiques de 60 meV. On trouve alors 3.35 eV pour le silicium cristallin et 4.4 eV pour le a-Si:H pour des rapports realistes des deux processus de thermalisation. Un important resultat de la simulation indique que la presence des etats localises dans le gap de mobilite du a-Si:H a peu d'effet sur epsilon_ {p}, ce qui mene a la conclusion que la recombinaison geminee joue un role negligeable dans la generation du signal par une particule.

  9. A Bis(Diphosphanyl N-Heterocyclic Carbene) Gold Complex: A Synthon for Luminescent Rigid AuAg2 Arrays and Au5 and Cu6 Double Arrays.

    PubMed

    Ai, Pengfei; Mauro, Matteo; De Cola, Luisa; Danopoulos, Andreas A; Braunstein, Pierre

    2016-03-01

    A mononuclear bis(NHC)/Au(I) (NHC=N-heterocyclic carbene) cationic complex with a rigid bis(phosphane)-functionalized NHC ligand (PCNHC P) was used to construct linear Au3 and Ag2 Au arrays, a Au5 cluster with two intersecting crosslike Au3 arrays, and an unprecedented Cu6 complex with two parallel Cu3 arrays. The impact of metallophilic interactions on photoluminescence was studied experimentally. PMID:26823329

  10. CO Oxidation mechanism on CeO2-supported Au nanoclusters

    SciTech Connect

    Kim H. Y.; Henkelman, G.

    2013-09-08

    To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters(NCs)/Nanoparticles, we design Au13 and Au12 supported on a flat and a stepped-CeO2 model (Au/CeO2) and study various kinds of CO oxidation mechanisms at the Au-CeO2 interface and the Au NC as well.

  11. Ordered arrays of Au catalysts by FIB assisted heterogeneous dewetting.

    PubMed

    Benkouider, A; Ronda, A; David, T; Favre, L; Abbarchi, M; Naffouti, M; Osmond, J; Delobbe, A; Sudraud, P; Berbezier, I

    2015-12-18

    Synthesizing Au0.8Si0.2 nanocatalysts that are homogeneous in size and have controlled position is becoming a challenging and crucial prequisite for the fabrication of ordered semiconductor nanowires. In this study, Au0.8Si0.2 nanocatalysts are synthesized via dewetting of Au layers on Si(111) during thermal annealing in an ultra-high vacuum. In the first part of the paper, the mechanism of homogeneous dewetting is analyzed as a function of the Au-deposited thickness (h Au). We distinguish three different dewetting regimes: (I) for a low thickness ([Formula: see text]), a submonolyer coverage of Au is stabilized and there is no dewetting. (II) For an intermediate thickness ([Formula: see text]), there is both dewetting and Au0.8Si0.2 phase formation. The size and density of the Au0.8Si0.2 clusters are directly related to h Au. When cooling down to room temperature, the clusters decompose and reject the Si at the Au/Si substrate interface. (III) For a large thickness ([Formula: see text]), only dewetting takes place, without forming AuSi clusters. In this regime, the dewetting is kinetically controlled by the self-diffusion of Au (activation energy ∼0.43 eV) without evidence of an Si-alloying effect. As a practical consequence, when relying solely on the homogeneous dewetting of Au/Si(111) to form the Au0.8Si0.2 catalysts (without a supply of Si atoms from vapor), regime II should be used to obtain good size and density control. In the second part of the paper, a process for ordering the catalysts using focused ion beam-(FIB) assisted dewetting (heterogeneous dewetting) is developed. We show that no matter what the FIB milling conditions and the Au nominal thickness are, dewetting is promoted by ion beam irradiation and is accompanied by the formation of Au0.8Si0.2 droplets. The droplets preferentially form on the patterned areas, while in similar annealing conditions, they do not form on the unpatterned areas. This behavior is attributed to the larger Au-Si interdiffusion in the patterned areas, which results from the Si amorphization induced by the FIB. A systematic analysis of the position of the nanodroplets shows their preferential nucleation inside the patterns, while thicker platelets of almost pure Au are observed between the patterns. The evolutions of the size homogeneity and the occupancy rate of the patterns are quantified as a function of the FIB dose and annealing temperature. Nice arrays of perfectly ordered AuSi catalysts are obtained after optimizing the FIB and dewetting conditions. PMID:26579983

  12. Wafer-level Au-Au bonding in the 350-450 °C temperature range

    NASA Astrophysics Data System (ADS)

    Tofteberg, Hannah R.; Schjølberg-Henriksen, Kari; Fasting, Eivind J.; Moen, Alexander S.; Taklo, Maaike M. V.; Poppe, Erik U.; Simensen, Christian J.

    2014-08-01

    Metal thermocompression bonding is a hermetic wafer-level packaging technology that facilitates vertical integration and shrinks the area used for device sealing. In this paper, Au-Au bonding at 350, 400 and 450 °C has been investigated, bonding wafers with 1 µm Au on top of 200 nm TiW. Test Si laminates with device sealing frames of 100, 200, and 400 µm in width were realized. Bond strengths measured by pull tests ranged from 8 to 102 MPa and showed that the bond strength increased with higher bonding temperatures and decreased with increasing frame width. Effects of eutectic reactions, grain growth in the Au film and stress relaxation causing buckles in the TiW film were most pronounced at 450 °C and negligible at 350 °C. Bond temperature below the Au-Si eutectic temperature 363 °C is recommended.

  13. Observation of D0 meson nuclear modifications in Au+Au collisions at sNN=200 GeV

    DOE PAGESBeta

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; et al

    2014-09-30

    We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K-+π+) in Au+Au collisions at √sNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p+p to central Au+Au collisions. The D0 meson yields in central Au+Aucollisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions andmore » coalescence hadronization describe our measurements.« less

  14. Jet structure of baryon excess in Au+Au collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Adler, S.S.; Aronson, S.H.; Chujo, T.; David, G.; Desmond, E.J.; Drees, K.A.; Ewell, L.; Franz, A.; Guryn, W.; Haggerty, J.S.; Harvey, M.; Johnson, B.M.; Kistenev, E.; Kroon, P.J.; Makdisi, Y.I.; Mioduszewski, S.; Mitchell, J.T.; Morrison, D.P.; O'Brien, E.; Pinkenburg, C.

    2005-05-01

    Two particle correlations between identified meson and baryon trigger particles with 2.5Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. In noncentral Au+Au collisions, the probability of finding a hadron near in azimuthal angle to the trigger particles is almost identical for mesons and baryons and significantly higher than in p+p collisions. The associated yields for trigger baryons decrease in the most central collisions, consistent with some baryon production by thermal recombination in addition to hard scattering.

  15. Observation of D0 meson nuclear modifications in Au+Au collisions at sNN=200 GeV

    DOE PAGESBeta

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; et al

    2014-09-30

    We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K-+π+) in Au+Au collisions at √sNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p+p to central Au+Au collisions. The D0 meson yields in central Au+Aucollisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions andmore »coalescence hadronization describe our measurements.« less

  16. Critical Au Concentration for the Stabilization of Au-Cu Nanoparticles on Rutile against Dissociation under Oxygen.

    PubMed

    Wilson, A; Bernard, R; Borensztein, Y; Croset, B; Cruguel, H; Vlad, A; Coati, A; Garreau, Y; Prévot, G

    2015-06-01

    Controlling aging of catalysts is of crucial importance to preserve their properties, in particular for bimetallic nanoparticles (NPs) where reaction can modify the composition. Herein, we have studied the stability upon oxygen exposure of gold-copper NPs supported on rutile. We have used in situ scanning tunneling microscopy to follow the evolution of individual Au, Cu and Au-Cu NPs with various compositions grown on the TiO2(110) surface, during each step from their nucleation to their modification with oxygen. We demonstrated a direct relation between the stability of the nanoparticles and their Au concentration. Whereas pure Cu nanoparticles dissociate under O2, Au-Cu NPs containing at least 20% Au are stable. This is explained by a modification of the local density of states of Cu atoms upon alloying. PMID:26266501

  17. Autonomous Repair Mechanism of Creep Damage in Fe-Au and Fe-Au-B-N Alloys

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Kwakernaak, C.; Tichelaar, F. D.; Sloof, W. G.; Kuzmina, M.; Herbig, M.; Raabe, D.; Brück, E.; van der Zwaag, S.; van Dijk, N. H.

    2015-12-01

    The autonomous repair mechanism of creep cavitation during high-temperature deformation has been investigated in Fe-Au and Fe-Au-B-N alloys. Combined electron-microscopy techniques and atom probe tomography reveal how the improved creep properties result from Au precipitation within the creep cavities, preferentially formed on grain boundaries oriented perpendicular to the applied stress. The selective precipitation of Au atoms at the free creep cavity surface results in pore filling, and thereby, autonomous repair of the creep damage. The large difference in atomic size between the Au and Fe strongly hampers the nucleation of precipitates in the matrix. As a result, the matrix acts as a reservoir for the supersaturated solute until damage occurs. Grain boundaries and dislocations are found to act as fast transport routes for solute gold from the matrix to the creep cavities. The mechanism responsible for the self-healing can be characterized by a simple model for cavity growth and cavity filling.

  18. Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S

    NASA Astrophysics Data System (ADS)

    Tian, Zhimei; Cheng, Longjiu

    2015-12-01

    Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters. Electronic supplementary information (ESI) available: The AdNDP localized natural bonding orbitals of the valence shells of the Au30S(SH)18 cluster. IR spectra, absorption spectra and coordinates of Au30S(SCH3)18, Au30(SCH3)18 and Au30S2(SCH3)18 clusters. See DOI: 10.1039/c5nr05020k

  19. Medium-sized Au40(SR)24 and Au52(SR)32 nanoclusters with distinct gold-kernel structures and spectroscopic features

    NASA Astrophysics Data System (ADS)

    Xu, Wen Wu; Li, Yadong; Gao, Yi; Zeng, Xiao Cheng

    2016-01-01

    We have analyzed the structures of two medium-sized thiolate-protected gold nanoparticles (RS-AuNPs) Au40(SR)24 and Au52(SR)32 and identified the distinct structural features in their Au kernels [Sci. Adv., 2015, 1, e1500425]. We find that both Au kernels of the Au40(SR)24 and Au52(SR)32 nanoclusters can be classified as interpenetrating cuboctahedra. Simulated X-ray diffraction patterns of the RS-AuNPs with the cuboctahedral kernel are collected and then compared with the X-ray diffraction patterns of the RS-AuNPs of two other prevailing Au-kernels identified from previous experiments, namely the Ino-decahedral kernel and icosahedral kernel. The distinct X-ray diffraction patterns of RS-AuNPs with the three different types of Au-kernels can be utilized as signature features for future studies of structures of RS-AuNPs. Moreover, the simulated UV/Vis absorption spectra and Kohn-Sham orbital energy-level diagrams are obtained for the Au40(SR)24 and Au52(SR)32, on the basis of time-dependent density functional theory computation. The extrapolated optical band-edges of Au40(SR)24 and Au52(SR)32 are 1.1 eV and 1.25 eV, respectively. The feature peaks in the UV/Vis absorption spectra of the two clusters can be attributed to the d --> sp electronic transition. Lastly, the catalytic activities of the Au40(SR)24 and Au52(SR)32 are examined using CO oxidation as a probe. Both medium-sized thiolate-protected gold clusters can serve as effective stand-alone nanocatalysts.We have analyzed the structures of two medium-sized thiolate-protected gold nanoparticles (RS-AuNPs) Au40(SR)24 and Au52(SR)32 and identified the distinct structural features in their Au kernels [Sci. Adv., 2015, 1, e1500425]. We find that both Au kernels of the Au40(SR)24 and Au52(SR)32 nanoclusters can be classified as interpenetrating cuboctahedra. Simulated X-ray diffraction patterns of the RS-AuNPs with the cuboctahedral kernel are collected and then compared with the X-ray diffraction patterns of the RS-AuNPs of two other prevailing Au-kernels identified from previous experiments, namely the Ino-decahedral kernel and icosahedral kernel. The distinct X-ray diffraction patterns of RS-AuNPs with the three different types of Au-kernels can be utilized as signature features for future studies of structures of RS-AuNPs. Moreover, the simulated UV/Vis absorption spectra and Kohn-Sham orbital energy-level diagrams are obtained for the Au40(SR)24 and Au52(SR)32, on the basis of time-dependent density functional theory computation. The extrapolated optical band-edges of Au40(SR)24 and Au52(SR)32 are 1.1 eV and 1.25 eV, respectively. The feature peaks in the UV/Vis absorption spectra of the two clusters can be attributed to the d --> sp electronic transition. Lastly, the catalytic activities of the Au40(SR)24 and Au52(SR)32 are examined using CO oxidation as a probe. Both medium-sized thiolate-protected gold clusters can serve as effective stand-alone nanocatalysts. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07810e

  20. Electron transfer catalysis with monolayer protected Au25 clusters

    NASA Astrophysics Data System (ADS)

    Antonello, Sabrina; Hesari, Mahdi; Polo, Federico; Maran, Flavio

    2012-08-01

    Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and the Au25L18+/Au25L18 redox couples as redox mediators. Simulation of the CV curves led to determination of the ET rate constant (kET) values for concerted dissociative ET to the peroxides. The ET free energy ΔG° could be estimated for all donor-acceptor combinations, leading to observation of a nice activation-driving force (log kETvs. ΔG°) relationship. Comparison with the kET obtained using a ferrocene-type donor with a formal potential similar to that of Au25L18/Au25L18- showed that the presence of the capping monolayer affects the ET rate rather significantly, which is attributed to the intrinsic nonadiabaticity of peroxide acceptors.Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and the Au25L18+/Au25L18 redox couples as redox mediators. Simulation of the CV curves led to determination of the ET rate constant (kET) values for concerted dissociative ET to the peroxides. The ET free energy ΔG° could be estimated for all donor-acceptor combinations, leading to observation of a nice activation-driving force (log kETvs. ΔG°) relationship. Comparison with the kET obtained using a ferrocene-type donor with a formal potential similar to that of Au25L18/Au25L18- showed that the presence of the capping monolayer affects the ET rate rather significantly, which is attributed to the intrinsic nonadiabaticity of peroxide acceptors. This article was submitted as part of a Themed Issue on metallic clusters. Other papers on this topic can be found in issue 14 of vol. 4 (2012). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale].

  1. Enantiospecific adsorption of cysteine on a chiral Au34 cluster

    NASA Astrophysics Data System (ADS)

    Pelayo, José de Jesús; Valencia, Israel; Díaz, Gabriela; López-Lozano, Xóchitl; Garzón, Ignacio L.

    2015-12-01

    The interaction of biological molecules like chiral amino acids with chiral metal clusters is becoming an interesting and active field of research because of its potential impact in, for example, chiral molecular recognition phenomena. In particular, the enantiospecific adsorption (EA) of cysteine (Cys) on a chiral Au55 cluster was theoretically predicted a few years ago. In this work, we present theoretical results, based on density functional theory, of the EA of non-zwitterionic cysteine interacting with the C3-Au34 chiral cluster, which has been experimentally detected in gas phase, using trapped ion electron diffraction. Our results show that, indeed, the adsorption energy of the amino acid depends on which enantiomers participate in the formation Cys-Au34 chiral complex. EA was obtained in the adsorption modes where both the thiol, and the thiol-amino functional groups of Cys are adsorbed on low-coordinated sites of the metal cluster surface. Similarly to what was obtained for the Cys-Au55 chiral complex, in the present work, it is found that the EA is originated from the different strength and location of the bond between the COOH functional group and surface Au atoms of the Au34 chiral cluster. Calculations of the vibrational spectrum for the different Cys-Au34 diastereomeric complexes predict the existence of a vibro-enantiospecific effect, indicating that the vibrational frequencies of the adsorbed amino acid depend on its handedness.

  2. Theoretical studies of acrolein hydrogenation on Au20 nanoparticle

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Chen, Zhao-Xu; He, Xiang; Kang, Guo-Jun

    2010-05-01

    Gold nanoparticles play a key role in catalytic processes. We investigated the kinetics of stepwise hydrogenation of acrolein on Au20 cluster model and compared with that on Au(110) surface. The rate-limiting step barrier of CC reduction is about 0.5 eV higher than that of CO hydrogenation on Au(110) surface. On Au20 nanoparticle, however, the energy barrier of the rate-determining step for CC hydrogenation turns out to be slightly lower than the value for the CO reduction. The selectivity difference on the two substrate models are attributed to different adsorption modes of acrolein: via the CC on Au20, compared to through both CC and CO on Au(110). The preference switch implies that the predicted selectivity of competitive hydrogenation depends on substrate model sensitively, and particles with more low-coordinated Au atoms than flat surfaces are favorable for CC hydrogenation, which is in agreement with experimental result.

  3. Modulated charge separation at tetraphenyl porphyrin/Au interfaces

    NASA Astrophysics Data System (ADS)

    Zidon, Y.; Shapira, Yoram; Dittrich, Th.

    2007-04-01

    A frequency and temperature dependent change of the sign of modulated surface photovoltage signals from metal-free tetraphenyl porphyrin (H2TPP)/Au junctions has been observed. The sign of the modulated photovoltage signal could be switched by using continuous (bias) illumination, while the sign depends on the wavelength of the bias light. The light induced modulation of the negative and positive charges in the H2TTP layer can be interpreted in terms of internal photoemission of electrons from Au into H2TTP and of hole escape after exciton dissociation at the H2TPP/Au junction.

  4. AuScope VLBI Project and Hobart 26-m Antenna

    NASA Technical Reports Server (NTRS)

    Lovell, Jim; Dickey, John; Reid, Brett; McCallum, Jamie; Shabala, Stas; Watson, Christopher; Ellingsen, Simon; Memin, Anthony

    2013-01-01

    This is a report on the activities carried out at the three AuScope VLBI observatories and the Hobart 26-m antenna. In 2012 the three AuScope 12-m antennas at Hobart (Hb), Katherine (Ke), and Yarragadee (Yg) completed their first full year of operations as an array. The Hobart 26-m antenna (Ho) continued to make a contribution to IVS, providing overlap with the Hb time series. In total the AuScope antennas and the Hobart 26 m observed for 146 antenna days in 2012. In this report we also briefly highlight our research activities during 2012 and our plans for 2013.

  5. Reversible phase changes in Ge-Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Guzman, J.; Boswell-Koller, C. N.; Beeman, J. W.; Bustillo, K. C.; Conry, T.; Dubón, O. D.; Hansen, W. L.; Levander, A. X.; Liao, C. Y.; Lieten, R. R.; Sawyer, C. A.; Sherburne, M. P.; Shin, S. J.; Stone, P. R.; Watanabe, M.; Yu, K. M.; Ager, J. W.; Chrzan, D. C.; Haller, E. E.

    2011-05-01

    We demonstrate a reversible phase transition in nanoparticles composed of a binary eutectic alloy, Ge-Au. The structure, 9 nm diameter nanoparticles embedded in silica, can be switched from bilobe to mixed using a 30 ns ultraviolet laser pulse. The structure can be switched back to bilobe by heating at 80 °C. The bilobe/mixed switching can be performed on the same sample at least ten times. Synchrotron X-ray diffraction studies reveal that the bilobe structure contains crystalline Ge and Au while the mixed structure consists of crystalline Ge and β Ge-Au.

  6. Fully Crystalline Faceted Fe-Au Core-Shell Nanoparticles.

    PubMed

    Langlois, C; Benzo, P; Arenal, R; Benoit, M; Nicolai, J; Combe, N; Ponchet, A; Casanove, M J

    2015-08-12

    Fe-Au core-shell nanoparticles displaying an original polyhedral morphology have been successfully synthesized through a physical route. Analyses using transmission electron microscopy show that the Au shell forms truncated pyramids epitaxially grown on the (100) facets of the iron cubic core. The evolution of the elastic energy and strain field in the nanoparticles as a function of their geometry and composition is calculated using the finite-element method. The stability of the remarkable centered core-shell morphology experimentally observed is attributed to the weak elastic energy resulting from the low misfit at the Fe/Au (100) interface compared to the surface energy contribution. PMID:26146846

  7. The ethanol electrooxidation at Pt layers deposited on polycrystalline Au.

    PubMed

    Prieto, Mauricio J; Rodrigues Filho, Ubirajara P; Landers, Richard; Tremiliosi-Filho, Germano

    2012-01-14

    The ethanol electro-oxidation reaction was evaluated using a polycrystalline Au substrate modified with two different amounts of Pt using the galvanic exchange methodology. FTIR results suggest that Pt deposits have a greater ability to break the C-C bond present in the ethanol molecule. However, under potentiostatic conditions both modified Au surfaces undergo faster deactivation in comparison with polycrystalline platinum as indicated by the chronoamperometric results. XPS results indicate the presence of two phases depending on the Pt content. These are: (i) Pt-Au alloy and (ii) segregated Pt. The structural and electronic properties of these phases were related to the differences observed in the catalytic activity. PMID:22116267

  8. Crystal Structure of the PdAu24(SR)18(0) Superatom.

    PubMed

    Tofanelli, Marcus A; Ni, Thomas W; Phillips, Billy D; Ackerson, Christopher J

    2016-02-01

    The single-crystal X-ray structure of Pd-doped Au25(SR)18 was solved. The crystal structure reveals that in PdAu24(SR)18, the Pd atom is localized only to the centroid of the Au25(SR)18 cluster. This single-crystal X-ray structure shows that PdAu24(SR)18(0) is well conceptualized with the superatom theory. The PdAu24(SR)18(0) charge state is isoelectronic with Au25(SR)18(+1) as determined by a first order Jahn-Teller effect of similar magnitude and by electrochemical comparison. The previously reported increased stability of PdAu24(SR)18 can be rationalized in terms of Pd-Au bonds that are shorter than the Au-Au bonds in Au25(SR)18. PMID:26760220

  9. First principles calculations of the optical and plasmonic response of Au alloys and intermetallic compounds.

    PubMed

    Keast, V J; Barnett, R L; Cortie, M B

    2014-07-30

    Pure Au is widely used in plasmonic applications even though its use is compromised by significant losses due to damping. There are some elements that are less lossy than Au (e.g. Ag or Al) but they will normally oxidize or corrode under ambient conditions. Here we examine whether alloying Au with a second element would be beneficial for plasmonic applications. In order to evaluate potential alternatives to pure Au, the density of states (DOS), dielectric function and plasmon quality factor have been calculated for alloys and compounds of Au with Al, Cd, Mg, Pd, Pt, Sn, Ti, Zn and Zr. Substitutional alloying of Au with Al, Cd, Mg and Zn was found to slightly improve the plasmonic response. Of the large number of intermetallic compounds studied, only AuAl2, Au3Cd, AuMg, AuCd and AuZn were found to be suitable for plasmonic applications. PMID:25001413

  10. Présentations de l'adénite tuberculeuse de la tête et du cou au CHU de Bobo-Dioulasso, Burkina Faso

    PubMed Central

    Béogo, Rasmané; Birba, Noraogo Emile; Coulibaly, Toua Antoine; Traoré, Ibraïma; Ouoba, Kampadilemba

    2013-01-01

    Les ganglions de la tête et du cou sont parmi les localisations les plus fréquentes de la tuberculose, un problème de santé publique dans le monde. Une étude rétrospective conduite entre 2001 et 2010 rapporte les caractéristiques épidémiologiques et cliniques de l'adénite tuberculeuse de la tête et du cou, au CHU Sanou Souro, au Burkina Faso. Au total, 115 patients ont été observés dont l'âge était compris entre 2 ans et 64 ans (moyenne 31,46 ans). Il y avait 53 patients de sexe masculin (46,1%) et 62 de sexe féminin (53,9%). Un pic de fréquence de 39,8% était observé entre 30 et 39 ans. Les adénopathies cervicales étaient multiples chez 96,5% des patients et abcédées chez 30%. Elles étaient associées à des adénopathies extra cervicales chez 16,6% des patients. Chez 83,4% des patients, il a été noté un ou plusieurs signes à type d'asthénie et ou d'amaigrissement (70,8%), de fièvre 25% ou de toux (20,8%). L'infection associée la plus fréquente était celle par le VIH, observée chez 43,3% des patients. Les résultats de cette étude commandent la recherche systématique de l'infection par le VIH chez tout patient porteur d'adénite cervicale tuberculeuse dans un contexte de double endémicité de la tuberculose et de l'infection à VIH. PMID:24319521

  11. Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

    SciTech Connect

    Cheng, Zhongzhou; Wang, Zhenxing E-mail: hej@nanoctr.cn; Shifa, Tofik Ahmed; Wang, Fengmei; Zhan, Xueying; Xu, Kai; He, Jun E-mail: hej@nanoctr.cn; Liu, Quanlin

    2015-11-30

    Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimize the type-II structures for photocatalytic water splitting.

  12. FT-ICR/MS and ab initio study of polynuclear Au and Au-Cu clusters in aqueous fluids

    NASA Astrophysics Data System (ADS)

    Lemke, K.; Tse, K.; Sadjadi, A.

    2011-12-01

    The geochemistry and transport of aqueous transition metals such as copper and gold in the Earth's crust is still poorly known. FT-ICR mass spectrometry and ab initio calculations can provide fundamental insight on a molecular-scale level into the structure, stability and abundance of relevant Cu and Au species. We have measured high temperature ion cluster mass spectra of aqueous gold and copper chloride solutions using a custom-modified FT-ICR mass spectrometer equipped with an electrospray ionization source. In pure dilute aqueous AuCl3 solutions (1-25mM), Au(III) is present as an ion complex [AuCl2]+ and is hydrated with up to four water molecules, with the trihydrate [AuCl2]+(H2O)3 being the most stable species. In addition, several polynuclear ion clusters were observed, e.g. the dinuclear ion [Au2Cl5]+, including the hydrated forms [Au2Cl5]+(H2O) and [Au2Cl5]+(H2O)2. In more concentrated AuCl3 solutions (100mM, pH=2.3) the protonated Zundel cation [H5O2]+, [H7O3]+ and Eigen cation [H9O4]+ were detected, suggesting that protonated water clusters are equally relevant species in crustal fluids. We also measured mass spectra of binary solutions of aqueous transition metals, i.e. CuCl2/AuCl3 (5mM) and detected mixed Au(III)/Cu(II)-chloro clusters up to the tetranuclear [AuCu3Cl8]+ ion and their hydrated forms. The ab initio component of this study was designed to deliver additional insight into the structure of individual transition metal clusters as well as to the relative stability of each species, both unhydrated and in the presence of water molecules. Ab initio calculations were first conducted using MP2 theory and results thereof were then applied as starting points for subsequent couple-cluster CCSD(T) theory calculations. For the dinuclear ion [Au2Cl5]+, for example, the MP2 global minimum is a planar structure (see Figure; A) with an Au-Au bond distance of 3.435Å, while the second isomer (see Figure; B) has an Au-Au bond distance of 3.588Å and is around 3.5 kJ/mol higher in energy. Theoretical [Au2Cl5]+ ion cluster geometries are then used to compute higher temperature heat capacity data that may be used to predict fundamental thermodynamic properties of transition metal-charged aqueous systems at elevated temperatures. Results from such mass spectrometric and ab initio studies would allow modeling of gold and copper speciation in crustal fluids and assist in understanding prenucleation processes in metal halides in nature.

  13. The growth and enhanced catalytic performance of Au@Pd core-shell nanodendrites

    NASA Astrophysics Data System (ADS)

    Wang, Haihua; Sun, Zhenhua; Yang, Yi; Su, Dangsheng

    2012-12-01

    Au@Pd core-shell nanodendrites were synthesized by reducing H2PdCl4 with ascorbic acid onto the surface of Au polyhedra at room temperature. The Au@Pd core-shell nanodendrites consisting of a Au core and nanoporous Pd shell, exhibited plasmonic properties and higher catalytic activity in comparison with Au@Pd core-shell nanocubes.Au@Pd core-shell nanodendrites were synthesized by reducing H2PdCl4 with ascorbic acid onto the surface of Au polyhedra at room temperature. The Au@Pd core-shell nanodendrites consisting of a Au core and nanoporous Pd shell, exhibited plasmonic properties and higher catalytic activity in comparison with Au@Pd core-shell nanocubes. Electronic supplementary information (ESI) available: Experimental details, characterization and catalytic performance measurement of Au nanopolyhedra and Au@Pd core-shell nanostructures, TEM image of Au nanopolyhedra and Au@Pd core-shell nanodendrites after four cycles of the Suzuki coupling reaction, TEM and high-resolution images of a single Au@Pd core-shell nanodendrite, and XRD pattern of Au@Pd core-shell nanodendrites, UV-vis spectrum of Au@Pd nanodendrites in the range 200-400 nm, references. See DOI: 10.1039/c2nr32849f

  14. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    SciTech Connect

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y| < 1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.

  15. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    DOE PAGESBeta

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  16. Design and Preparation of Supported Au Catalyst with Enhanced Catalytic Activities by Rationally Positioning Au Nanoparticles on Anatase.

    PubMed

    Wang, Liang; Wang, Hong; Rice, Andrew E; Zhang, Wei; Li, Xiaokun; Chen, Mingshu; Meng, Xiangju; Lewis, James P; Xiao, Feng-Shou

    2015-06-18

    A synergistic effect between individual components is crucial for increasing the activity of metal/metal oxide catalysts. The greatest challenge is how to control the synergistic effect to obtain enhanced catalytic performance. Through density functional theory calculations of model Au/TiO2 catalysts, it is suggested that there is strong interaction between Au nanoparticles and Ti species at the edge/corner sites of anatase, which is favorable for the formation of stable oxygen vacancies. Motivated by this theoretical analysis, we have rationally prepared Au nanoparticles attached to edge/corner sites of anatase support (Au/TiO2-EC), confirmed by their HR-TEM images. As expected, this strong interaction is well characterized by Raman, UV-visible, and XPS techniques. Very interestingly, compared with conventional Au catalysts, Au/TiO2-EC exhibits superior catalytic activity in the oxidations using O2. Our approach to controlling Au nanoparticle positioning on anatase to obtain enhanced catalytic activity offers an efficient strategy for developing more novel supported metal catalysts. PMID:26266615

  17. Chemical and electrical characteristics of annealed Ni/Au and Ni/Ir/Au contacts on AlGaN

    NASA Astrophysics Data System (ADS)

    Ngoepe, P. N. M.; Meyer, W. E.; Auret, F. D.; Omotoso, E.; Diale, M.; Swart, H. C.; Duvenhage, M. M.; Coetsee, E.

    2016-01-01

    The evolution of Ni/Au and Ni/Ir/Au metal contacts deposited on AlGaN was investigated at different annealing temperatures. The samples were studied with electrical and chemical composition techniques. I-V characteristics of the Schottky diodes were optimum after 500 and 600 °C annealing for Ni/Au and Ni/Ir/Au based diodes, respectively. The depth profiles of the contacts were measured by x-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy. These chemical composition techniques were used to examine the evolution of the metal contacts in order to verify the influence the metals have on the electrical properties of the diodes. The insertion of Ir as a diffusion barrier between Ni and Au effected the electrical properties, improving the stability of the contacts at high temperatures. Gold diffused into the AlGaN film, degrading the electrical properties of the Ni/Au diode. At 500 °C, the insertion of Ir, however, prevented the in-diffusion of Au into the AlGaN substrate.

  18. From superatomic Au25(SR)18(-) to superatomic M@Au24(SR)18(q) core-shell clusters.

    PubMed

    Jiang, De-en; Dai, Sheng

    2009-04-01

    Au(25)(SR)(18)(-) belongs to a new type of superatom that features an icosahedral Au(13) core-shell structure and a protective layer of six RS(Au-SR)(2) motifs. This superatom has a magic number of 8 free electrons that fully fill the 1s and 1p levels of the electron-shell model. By applying this superatom concept to the core-substitution chemistry of Au(25)(SR)(18)(-), we first scanned the periodic table for the potential core atom M by applying a simple rule derived from the 8-electron count and then optimized the selected candidates by density functional theory calculations to create many series of M@Au(24)(SR)(18)(q) core-shell nanoclusters. We found that 16 elements from groups 1, 2, and 10-14 of the periodic table can maintain both electronic and geometric structures of the original Au(25)(SR)(18)(-) magic cluster, indicating that the electron-counting rule based on the superatom concept is powerful in predicting viable M@Au(24)(SR)(18)(q) clusters. Our work opens up a promising area for experimental exploration. PMID:19236016

  19. Characteristics of Au Migration and Concentration Distributions in Au-Doped HgCdTe LPE Materials

    NASA Astrophysics Data System (ADS)

    Sun, Quanzhi; Yang, Jianrong; Wei, Yanfeng; Zhang, Juan; Sun, Ruiyun

    2015-08-01

    Annealing techniques and secondary ion mass spectrometry have been used to study the characteristics of Au migration and concentration distributions in HgCdTe materials grown by liquid phase epitaxy. Secondary ion mass spectrometry measurements showed that Au concentrations had obvious positive correlations with Hg-vacancy concentration and dislocation density of the materials. Au atoms migrate toward regions of high Hg-vacancy concentration or move away from these regions when the Hg-vacancy concentration decreases during annealing. The phenomenon can be explained by defect chemical equilibrium theory if Au atoms have a very large migration velocity compared with Hg vacancies. Au atoms will also migrate toward regions of high dislocation density, leading to a peak concentration in the inter-diffusion region of HgCdTe materials near the substrate. By use of an Hg and Te-rich annealing technique, different concentration distributions of both Au atoms and Hg vacancies in HgCdTe materials were obtained, indicating that Au-doped HgCdTe materials can be designed and prepared to satisfy the requirements of HgCdTe devices.

  20. Au and Ag/Au double-shells hollow nanoparticles with improved near infrared surface plasmon and photoluminescence properties.

    PubMed

    Ghosh Chaudhuri, Rajib; Paria, Santanu

    2016-01-01

    Metallic hollow nanoparticles have been continuously drawing researcher's attention because of their excellent improved performance compare to the spherical particles in catalysis, photonics, information storage, surface-enhanced Raman scattering, and sensors applications. In this article we demonstrate a novel route for the synthesis of single and double-shells Au and Ag/Au bimetallic hollow nanoparticles using elemental sulfur as a sacrificial core. We also investigate the optical properties of these new hollow particles and compare with that of pure spherical nanoparticles. The surface plasmon resonance spectra of solid Au, hollow single shell Au, and double shells Ag/Au nanoparticles show that there is gradual shifting of Au peak position towards the higher wavelengths for these three nanoparticles respectively. A similar observation was also found for photoluminescence spectra. In case of double-shells Ag/Au hollow nanoparticles the emission spectrum shifts towards the NIR region with significant higher intensity, which is beneficial for in vivo biomedical applications of these particles. PMID:26397903

  1. Transverse-energy distributions at midrapidity in p +p, d +Au, and Au +Au collisions at √sNN =62.4-200 GeV and implications for particle-production models

    NASA Astrophysics Data System (ADS)

    Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Jamel, A.; Alexander, J.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Bazilevsky, A.; Belikov, S.; Bennett, R.; Berdnikov, Y.; Bjorndal, M. T.; Boissevain, J. G.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Campbell, S.; Chai, J.-S.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanád, M.; Csörgő, T.; Cussonneau, J. P.; Dahms, T.; Das, K.; David, G.; Deák, F.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Devismes, A.; Dietzsch, O.; Dion, A.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Dubey, A. K.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Efremenko, Y. V.; Egdemir, J.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Fields, D. E.; Finck, C.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fung, S.-Y.; Gadrat, S.; Gastineau, F.; Germain, M.; Glenn, A.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haggerty, J. S.; Hagiwara, M. N.; Hamagaki, H.; Hansen, A. G.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hidas, P.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Horaguchi, T.; Hur, M. G.; Ichihara, T.; Iinuma, H.; Ikonnikov, V. V.; Imai, K.; Inaba, M.; Inuzuka, M.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kaneta, M.; Kang, J. H.; Katou, K.; Kawabata, T.; Kawagishi, T.; Kazantsev, A. V.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. J.; Kim, E.; Kim, E. J.; Kim, G.-B.; Kim, H. J.; Kim, Y.-S.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Kohara, R.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lajoie, J. G.; Lebedev, A.; Leâ Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, M. K.; Leitch, M. J.; Leite, M. A. L.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mao, Y.; Martinez, G.; Masui, H.; Matathias, F.; Matsumoto, T.; McCain, M. C.; McGaughey, P. L.; Miake, Y.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Muniruzzaman, M.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nakamura, T.; Newby, J.; Nguyen, M.; Norman, B. E.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Omiwade, O. O.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Penev, V.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pierson, A.; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Qualls, J. M.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sarsour, M.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, C. P.; Singh, V.; Skutnik, S.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Taranenko, A.; Tarján, P.; Thomas, T. L.; Togawa, M.; Tojo, J.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Uam, T. J.; Vale, C.; Valle, H.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Vértesi, R.; Veszprémi, V.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wagner, M.; Wang, X. R.; Watanabe, Y.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Wohn, F. K.; Woody, C. L.; Wysocki, M.; Xie, W.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.; Zong, X.; Phenix Collaboration

    2014-04-01

    Measurements of the midrapidity transverse-energy distribution, dET/dη, are presented for p +p, d +Au, and Au +Au collisions at √sNN =200 GeV and additionally for Au +Au collisions at √sNN =62.4 and 130 GeV. The dET/dη distributions are first compared with the number of nucleon participants Npart, number of binary collisions Ncoll, and number of constituent-quark participants Nqp calculated from a Glauber model based on the nuclear geometry. For Au +Au, /Npart increases with Npart, while /Nqp is approximately constant for all three energies. This indicates that the two-component ansatz, dET/dη ∝(1-x)Npart/2+xNcoll, which was used to represent ET distributions, is simply a proxy for Nqp, and that the Ncoll term does not represent a hard-scattering component in ET distributions. The dET/dη distributions of Au +Au and d +Au are then calculated from the measured p +p ET distribution using two models that both reproduce the Au +Au data. However, while the number-of-constituent-quark-participant model agrees well with the d +Au data, the additive-quark model does not.

  2. Activated Dissociation of HCl on Au(111).

    PubMed

    Shirhatti, Pranav R; Geweke, Jan; Steinsiek, Christoph; Bartels, Christof; Rahinov, Igor; Auerbach, Daniel J; Wodtke, Alec M

    2016-04-01

    We report zero-coverage reaction probabilities (S0) for HCl dissociative adsorption on Au(111) obtained by the seeded molecular beam hot-nozzle method. For measurements at normal incidence with mean translational energies ranging from 0.94 to 2.56 eV (nozzle temperatures 296 to 1060 K), S0 increased from 6 × 10(-6) to 2 × 10(-2). S0 also increased with increasing nozzle temperature for fixed incidence energy associated with the motion normal to the surface. Accounting for the influence of the vibrational state population and translational energy distributions in the incident beam, we are able to compare the experimental results to recent theoretical predictions. These calculations, performed employing 6-D quantum dynamics on an electronically adiabatic potential energy surface obtained using density functional theory at the level of the generalized gradient approximation and the static surface approximation, severely overestimate the reaction probabilities when compared with our experimental results. We discuss some possible reasons for this large disagreement. PMID:26990513

  3. Visible light photoactivity of TiO2 loaded with monometallic (Au or Pt) and bimetallic (Au/Pt) nanoparticles

    NASA Astrophysics Data System (ADS)

    Gołąbiewska, Anna; Lisowski, Wojciech; Jarek, Marcin; Nowaczyk, Grzegorz; Zielińska-Jurek, Anna; Zaleska, Adriana

    2014-10-01

    TiO2 modified with monometallic (Au or Pt) and bimetallic (Au/Pt) nanoparticles have been prepared using a water-in-oil microemulsion system (water/AOT/cyclohexane) followed by calcination step. The effect of metal ratio, reducing agent type (NaBH4 or N2H4), TiO2 matrix type (P-25, ST-01, TiO-5, TiO2 nanotubes or TiO2 obtained by TIP hydrolysis) as well as calcination temperature (from 350 to 650 °C) were systematically investigated. Obtained photocatalysts were characterized by UV-vis diffuse-reflectance spectroscopy (DRS), BET surface area measurements, scanning transmission microscopy (STEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity under visible light (λ > 420 nm) has been estimated in phenol degradation reaction in aqueous phase. The results showed that phenol degradation rate under visible light in the presence of TiO2 loaded with Au/Pt nanoparticles differed from 0.7 to 2.2 μmol dm-3 min-1 for samples prepared using different reducing agent. Sodium borohydride (NaBH4) favors formation of smaller Au/Pt nanoparticles and higher amount gold in Au/Pt is in the form of electronegative species (Auδ-) resulted in higher photoactivity. TiO2 obtained by TIP hydrolysis in microemulsion system seems to be the best support for Au/Pt nanoparticles from all among investigated matrix. It was also observed that enhancement of calcination temperature from 450 to 650 °C resulted in rapid drop of Au/Pt-TiO2 photoactivity under visible light due to surface area shrinkage, crystal structure change and probably change in Au/Pt nanoparticles morphology.

  4. Metanephrine neuroendocrine tumor marker detection by SERS using Au nanoparticle/Au film sandwich architecture.

    PubMed

    Boca, Sanda; Farcau, Cosmin; Baia, Monica; Astilean, Simion

    2016-02-01

    Neuroendocrine tumors, such as pheochromocytoma or paraganglioma, are dangerous tumors that constitute a potential threat for a large number of patients. Currently, the biochemical diagnosis of neuroendocrine tumors is based on measurement of the direct secretory products of the adrenomedullary-sympathetic system or of their metabolites, such as catecholamines or their metanephrine derivatives, from plasma or urine. The techniques used for analysis of plasma free metanephrines, i.e. high-performance liquid chromatography or high-performance liquid chromatography coupled with mass-spectrometry are technically-demanding and time consuming, which limit their availability. Here we demonstrate a simple, fast and low-cost method for detecting metanephrine by Surface Enhanced Raman Scattering (SERS). The protocol consists in using evaporation-induced self-assembly of gold (Au) nanoparticles incubated with the analyte, on planar gold films. The assembly process produces regions with a dense distribution of both inter-particle gaps and particle-film gaps. Finite-difference time-domain simulations confirm that both kinds of gaps are locations of enhanced electromagnetic fields resulting from inter-particle and particle-film plasmonic coupling, useful for SERS amplification. Metanephrine vibrational bands assignment was performed according to density functional theory calculations. Metanephrine metabolite was detected in liquid at concentration levels lower than previously reported for other similar metabolites. The obtained results demonstrate that the Au nanoparticle/Au film exhibits noticeable SERS amplification of the adsorbed metabolite and can be used in the design of efficient, stable SERS-active substrates for the detection and identification of specific tumor markers. PMID:26820563

  5. Heterostructured Au/Pd-M (M = Au, Pd, Pt) nanoparticles with compartmentalized composition, morphology, and electrocatalytic activity

    NASA Astrophysics Data System (ADS)

    Lutz, Patrick S.; Bae, In-Tae; Maye, Mathew M.

    2015-09-01

    The synthesis, processing, and galvanic exchange of three heterostructured nanoparticle systems is described. The surface accessibility and redox potential of a Au/Pd-Ag dumbbell nanoparticle, where a Au/Pd core/shell region, and a silver region make up the domains, was used to prepare the new nanostructures with controlled composition, morphology, and microstructure. Results indicate that the silver domain was particularly susceptible to galvanic displacement, and was exchanged to Au/Pd-M (M = Au, Pd, Pt). Interestingly, the dumbbell morphology remained after exchange, and the silver region was transformed to hollow, parachute, or concentric domains respectively. The morphology and microstructure change was visualized via TEM and HRTEM, and the composition changes were probed via STEM-EDS imaging and XPS. The electrocatalytic activity of the Au/Pd-M towards methanol oxidation was studied, with results indicating that the Au/Pd-Pt nanoparticles had high activity attributed to the porous nature of the platinum domains.The synthesis, processing, and galvanic exchange of three heterostructured nanoparticle systems is described. The surface accessibility and redox potential of a Au/Pd-Ag dumbbell nanoparticle, where a Au/Pd core/shell region, and a silver region make up the domains, was used to prepare the new nanostructures with controlled composition, morphology, and microstructure. Results indicate that the silver domain was particularly susceptible to galvanic displacement, and was exchanged to Au/Pd-M (M = Au, Pd, Pt). Interestingly, the dumbbell morphology remained after exchange, and the silver region was transformed to hollow, parachute, or concentric domains respectively. The morphology and microstructure change was visualized via TEM and HRTEM, and the composition changes were probed via STEM-EDS imaging and XPS. The electrocatalytic activity of the Au/Pd-M towards methanol oxidation was studied, with results indicating that the Au/Pd-Pt nanoparticles had high activity attributed to the porous nature of the platinum domains. Electronic supplementary information (ESI) available: Fig. S1-S5. See DOI: 10.1039/c5nr03562g

  6. The influence of size effects in Pt and Au nanoparticles studied by 197Au Mssbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Paulus, P. M.; Goossens, A.; Thiel, R. C.; Schmid, G.; van der Kraan, A. M.; de Jongh, L. J.

    2000-07-01

    We present a detailed Mssbauer study of a series of Au and Pt particles in the size range from 1 to 17 nm. All measured spectra can be explained consistently with a refined model, in which the Mssbauer isomer shift varies in the inner core of a small metallic particle due to size effects. The large surface/volume ratio makes surface effects, like screening of considerable importance and even the so-called quantum-size effect may have an influence. The size evolution of the electronic properties of the particles is also discussed.

  7. Au transport in catalyst coarsening and Si nanowire formation.

    PubMed

    Kim, B J; Tersoff, J; Kodambaka, S; Jang, Ja-Soon; Stach, E A; Ross, F M

    2014-08-13

    The motion of Au between AuSi liquid eutectic droplets, both before and during vapor-liquid-solid growth, is important in controlling tapering and diameter uniformity in Si nanowires. We measure the kinetics of coarsening of AuSi droplets on Si(001) and Si(111), quantifying the size evolution of droplets during annealing in ultrahigh vacuum using in situ transmission electron microscopy. For individual droplets, we show that coarsening kinetics are modified when disilane or oxygen is added: coarsening rates increase in the presence of disilane but decrease in oxygen. Matching droplet size measurements on Si(001) with coarsening models confirms that Au transport is driven by capillary forces and that the kinetic coefficients depend on the gas environment present. We suggest that the gas effects are qualitatively similar whether transport is attachment limited or diffusion limited. These results provide insight into manipulating nanowire morphologies for advanced device fabrication. PMID:25040757

  8. Assembling Bare Au Nanoparticles at Positively Charged Templates.

    PubMed

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

    2016-01-01

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), display less in-plane regular packing compared to bare AuNPs. PMID:27225047

  9. Microwave synthesis of Au nanoparticles as promising SERS substrates

    NASA Astrophysics Data System (ADS)

    Wang, Lan; Feng, Shangyuan; Liu, Nenrong; Lei, Jinping; Lin, Hongxin; Sun, Liqing; Chen, Rong

    2012-11-01

    A novel method for rapidly synthesized Au colloidal under microwave irradiation was present in this paper. Size of the Au nanoparticles varied from 10 nm to 60 nm along with varying mol fractions by chloroauric acid solution reduced with sodium citrate. The prepared Au nanoparticles were characterized by transmission electron microscope (TEM) and ultraviolet-visible (UV-Vis) spectrophotometer. It is found that the nanoparticle size and shape are highly dependent on the reaction time and the molar ratios of the reducing agent. By the SERS measurements of R6G, 4-MBA and Crystal violet, this Au colloid is shown to be an excellent SERS substrate with good stability. As the fabrication process of this SERS substrate is simple and inexpensive, this method may be used in large-scale preparation of substrates that can serve as an ideal SERS substrate in biomedical application.

  10. Efficient synthesis of Au99(SR)42 nanoclusters

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Lin, Jizhi; Shi, Yangwei; Li, Gao

    2015-03-01

    We report a new synthetic protocol of Au99(SPh)42 nanoclusters with moderate efficiency (~15% yield based on HAuCl4), via a combination of the ligand-exchange and ``size-focusing'' processes. The purity of the as-prepared gold nanoclusters is characterized by matrix-assisted laser desorption ionization mass spectrometry and size exclusion chromatography.We report a new synthetic protocol of Au99(SPh)42 nanoclusters with moderate efficiency (~15% yield based on HAuCl4), via a combination of the ligand-exchange and ``size-focusing'' processes. The purity of the as-prepared gold nanoclusters is characterized by matrix-assisted laser desorption ionization mass spectrometry and size exclusion chromatography. Electronic supplementary information (ESI) available: Experimental section: the synthetic procedure of the Au99(SPh)42 nanoclusters and characterization of the Au cluster. See DOI: 10.1039/c5nr00543d

  11. Glass formability and the Al-Au system

    SciTech Connect

    Egami, Takeshi; Ojha, Madhusudan; Nicholson, Donald M.; Louzguine-Luzgin, Dmitri; Chen, Na; Inoue, A.

    2012-01-01

    The aluminum-gold system exhibits various features that suggest high glass formability, such as a deep eutectic, formation of icosahedral clusters in the intermetallic compound near the eutectic minimum and a strongly negative heat of mixing. However, it is very difficult to form a glass with this system. Various issues related to glass formability are discussed using the Al-Au system as a negative test-case. In particular, the atomic level pressure was calculated from first principles for the first time for Al{sub 2}Au, AlAu{sub 2} and AlAu{sub 4} intermetallic compounds. The atomic level pressure is very high in these compounds, suggesting frustrated electronic states which destabilize both crystalline and glassy phases.

  12. Magnetic order of Au nanoparticle with clean surface

    NASA Astrophysics Data System (ADS)

    Sato, Ryuju; Ishikawa, Soichiro; Sato, Hiroyuki; Sato, Tetsuya

    2015-11-01

    Au nanoparticles, which are kept in vacuum after the preparation by gas evaporation method, show ferromagnetism even in 1.7 nm in diameter. The intrinsic magnetism is examined by detecting the disappearance of spontaneous magnetization in Au bulk prepared by heating the nanoparticles without exposure to the air. The temperature dependence of spontaneous magnetization is not monotonic and the increase in magnetization is observed after Au nanoparticles are exposed to the air. The magnetic behavior can be interpreted by the ferrimagnetic-like core-shell structure with shell thickness of 0.16±0.01 nm and magnetic moment of (1.5±0.1)×10-2 μB/Au atom, respectively.

  13. Café-au-lait spots in schoolchildren.

    PubMed Central

    Burwell, R G; James, N J; Johnston, D I

    1982-01-01

    This paper reports a study of café-au-lait spots of a minimum diameter of 1 cm in 732 white schoolchildren. Three groups were identified, according to the number of café-au-lait spots on each child: (1) those with none (74%), (2) those with fewer than 5 (25%), and (3) those with at least 5 (5 children, 2 considered to be normal, and 3 siblings each presumed to have neurofibromatosis, one having died from leukaemia). Excluding the last group, the number of café-au-lait spots in the sample was not significantly related to age or sex. Some support is given for using the number of café-au-lait spots as an empirical threshold to diagnose neurofibromatosis. PMID:6810767

  14. Au/p-diamond ohmic contacts deposited by RF sputtering

    NASA Astrophysics Data System (ADS)

    Zhen, C. M.; Wang, X. Q.; Wu, X. C.; Liu, C. X.; Hou, D. L.

    2008-12-01

    Ohmic contacts have been formed on diamond films using a monolayer Au. Au film was deposited by radio frequency sputtering. I- V measurements show the good ohmic behavior of the contacts in the as-deposited and annealed states and the specific contact resistivity obtained by circular transmission line model was 1.27 × 10 -3 and 5.43 × 10 -4 Ω cm 2, respectively. Radio frequency sputtering makes an obvious interdiffusion between Au and diamond in the as-deposited contacts. Annealing the contact enhances the interdiffusion. X-ray photoelectron spectroscopy analyses and cross-sectional scan electron microscopy reveal the presence of an intermediate layer at the interface due to the intermixing between Au and diamond. Surface native oxide of the diamond film was effectively removed by treating the substrate film in boiling aqua regia solution.

  15. Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Gronstal, S; Grosnick, D; Guertin, S M; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Hughes, E; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Levine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; Vandermolen, A M; Varma, R; Vasilevski, I; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Vznuzdaev, M; Waggoner, W; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Yuting, B; Zanevski, Y V; Zhang, H; Zhang, W M; Zhang, Z P; Zhaomin, Z P; Zizong, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2005-10-01

    Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed. PMID:16241721

  16. Ordering kinetics in the alloy Au4Cr

    NASA Astrophysics Data System (ADS)

    Starenchenko, S. V.; Sizonenko, N. R.; Kozlov, É. V.

    1991-12-01

    The kinetics of the appearance of long-range order and the growth of antiphase domains (APD) in the alloy Au4Cr with the superstructure Dla in the ordered state are studied by x-ray diffraction methods. The features of the incubation period are investigated. It is established that ordering in the alloy Au4Cr occurs heterogeneously with the nucleation of well-ordered particles.

  17. Melting curve of metals Cu, Ag and Au under pressure

    NASA Astrophysics Data System (ADS)

    Tam, Pham Dinh; Hoc, Nguyen Quang; Tinh, Bui Duc; Tan, Pham Duy

    2016-01-01

    In this paper, the dependence of the melting temperature of metals Cu, Ag and Au under pressure in the interval from 0 kbar to 40 kbar is studied by the statistical moment method (SMM). This dependence has the form of near linearity and the calculated slopes of melting curve are 3.9 for Cu, 5.7 for Ag and 6 for Au. These results are in good agreement with the experimental data.

  18. Hyperfine field distributions in Au(Fe) spin glass

    NASA Astrophysics Data System (ADS)

    Nakai, Y.; Furukawa, Y.; Kunitomi, N.

    1986-02-01

    On the basis of the Mookerjee-Roy theory, the hyperfine field distribution P( Hhf) obtained from the Mössbauer absorption spectra for the Au 0.841Fe 0.159 alloy is well reproduced at any temperature except near the freezing temperature. For the Au 0.832Fe 0.168 alloy, however, the observed shoulder in P( Hhf) cannot be explained by the theory.

  19. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    DOE PAGESBeta

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore »rapidity range |y| dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  20. Modification of Au surfaces using new ferrocene derivatives

    NASA Astrophysics Data System (ADS)

    Díaz-Ortiz, Tanya L.; Malavé-León, María; Rivera-Claudio, Mirna; Castillo-Ramírez, Jorge; Cabrera-Martínez, Carlos R.; Brito-Gómez, Rosa; Tremont, Rolando J.

    2008-01-01

    Gold surfaces have been modified by self-assembled techniques. Here the adsorption time of diasteroisomers (1 R, 3 S)-1-ferrocenyl-3-methyl-4,4-diphenyl-2,5-dioxacyclopentane and (1 S, 3 S)-1-ferrocenyl-3-methyl-4,4-diphenyl-2,5-dioxacyclopentane ( Scheme 1, 3a and 3b) at a Au surface in ethanol solution was controlled. This study was followed by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) analysis. The method used for the surface modification was the control of exposure time of a Au surface in the modifier/ethanol solution. It was demonstrated by EIS and XPS that the Au surface was modified with mixture of compounds 3a + 3b, avoiding the electron transference in the interface. It was also observed that the organometallic molecule indeed had been adsorbed on the Au surface. In addition, evidence seems to conclude that the molecule-Au interaction is through the electrons of cyclopentadienyl moiety, where the oxygen atoms are near the air-molecule interface and the iron atom is near the Au surface. This type of interaction of the ferrocene derivatives with gold surfaces has not been reported by any other author.

  1. Structural and dynamical properties of liquid Al-Au alloys

    NASA Astrophysics Data System (ADS)

    Peng, H. L.; Voigtmann, Th.; Kolland, G.; Kobatake, H.; Brillo, J.

    2015-11-01

    We investigate temperature- and composition-dependent structural and dynamical properties of Al-Au melts. Experiments are performed to obtain accurate density and viscosity data. The system shows a strong negative excess volume, similar to other Al-based binary alloys. We develop a molecular-dynamics (MD) model of the melt based on the embedded-atom method (EAM), gauged against the available experimental liquid-state data. A rescaling of previous EAM potentials for solid-state Au and Al improves the quantitative agreement with experimental data in the melt. In the MD simulation, the admixture of Au to Al can be interpreted as causing a local compression of the less dense Al system, driven by less soft Au-Au interactions. This local compression provides a microscopic mechanism explaining the strong negative excess volume of the melt. We further discuss the concentration dependence of self- and interdiffusion and viscosity in the MD model. Al atoms are more mobile than Au, and their increased mobility is linked to a lower viscosity of the melt.

  2. Biosupported Bimetallic Pd Au Nanocatalysts for Dechlorination of Environmental Contaminants

    SciTech Connect

    De Corte, S.; Fitts, J.; Hennebel, T.; Sabbe, T.; Bliznuk, V.; Verschuere, S.; van der Lelie, D.; Verstraete, W.; Boon, N.

    2011-08-30

    Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichloroethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L{sup -1} and reduced simultaneously by Shewanella oneidensis in the presence of H{sub 2}, the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenac after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.

  3. Hohlraum Te Inferred from Au L-Shell Emission

    NASA Astrophysics Data System (ADS)

    Regan, S. P.; Epstein, R.; Meyerhofer, D. D.; Sangster, T. C.; May, M. J.; Schneider, M. B.; Barrios, M. A.; Moody, J. D.; Baker, K. L.; Berzak Hopkins, L.; Brown, G. V.; Callahan, D.; Doeppner, T.; Fournier, K. B.; Hinkel, D. E.; Jones, O. S.; Kauffman, R.; Khan, S.; Kilkenny, J. D.; Landen, O. L.; Liedahl, D. A.; Nagel, S. R.; Ross, J. S.; Smalyuk, V. A.

    2014-10-01

    Laser-ablation plasmas created at the inner wall of the hohlraum (Au bubble) and at the laser entrance hole (LEH) radiate L-shell emission from Ne-like to Co-like charge states of Au. A 1-D spatially resolved and time-integrated spectrum in the 6- to 16-keV range with E/d E = 100 to 300 is recorded along the axis of the hohlraum. The Au L-shell spectral line shapes of the 2p3 / 2 - 3 s , 2p3 / 2 - 3d5 / 2 , and 2p1 / 2 - 3d3 / 2 transitions are analyzed using an atomic physics code to infer the Te of the radiating plasma. Preliminary results indicate the Au LEH plasma of a near-vacuum hohlraum has an inferred Te of 5 to 6 keV, while a gas-filled hohlraum has a significantly lower Te. A comparison of the Au L-shell spectra and the Te sensitivity will be presented, along with the plan to measure the L-shell emission from the Au bubble. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944. Part of this work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  4. Rotating Au nanorod and nanowire driven by circularly polarized light.

    PubMed

    Liaw, Jiunn-Woei; Chen, Ying-Syuan; Kuo, Mao-Kuen

    2014-10-20

    The wavelength-dependent optical torques provided by a circularly polarized (CP) plane wave driving Au nanorod (NR) and nanowire (NW) to rotate constantly were studied theoretically. Using the multiple multipole method, the resultant torque in terms of Maxwell's stress tensor was analyzed. Numerical results show that the optical torque spectrum is in accordance with the absorption spectrum of Au NR/NW. Under the same fluence, the maximum optical torque occurs at the longitudinal surface plasmon resonance (LSPR) of Au NR/NW, accompanied by a severe plasmonic heating. The rotation direction of the light-driven NR/NW depends on the handedness of CP light. In contrast, the optical torque exerted on Au NR/NW illuminated by a linearly polarized light is null at LSPR. Due to the plasmonic effect, the optical torque on Au NR/NW by CP light is two orders of magnitude larger than that on a dielectric NR/NW of the same size. The steady-state rotation of NR/NW in water, resulting from the balance of optical torque and viscous torque, was also discussed. Our finding shed some light on manipulating a CP light-driven Au NR/NW as a rotating nanomotor for a variety of applications in optofluidics and biophysics. PMID:25401634

  5. Improved structural features of Au-catalyzed silicon nanoneedles

    NASA Astrophysics Data System (ADS)

    Mohammed, Yasir Hussein; Sakrani, Samsudi Bin; Rohani, Md Supar

    2015-09-01

    Nanometer sized silicon (Si) needles (nanowires) offer a vehicle for varieties of applications at nanoscale. We grow Si nanoneedles (SiNNs) using very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method with distinct gold (Au) nanostructures (NSs) as catalyst. Au NSs in the form of nanoparticles (NPs) and continuous thin film are prepared on Si(1 0 0) substrates via radio frequency magnetron sputtering. Au catalyst size dependent surface morphology and structural features of these SiNNs are determined. Samples are characterized via imaging and spectroscopic measurements. Controlled growth of such SiNNs structure with reproducibility that is achieved via Au NPs size tunability is attributed to the vapor-liquid-solid (VLS) growth mechanism. SiNNs with diameters between 20 and 120 nm and length up to 5 ?m are acquired. SiNNs diameter is found to increase with the increase of Au NPs size. Processing parameters optimization is demonstrated to play a critical role in nucleating Au NPs and thereby achieving high density SiNNs morphology. X-ray diffraction patterns authenticated an enhanced SiNNs crystallinity with increasing catalyst size. Raman spectra of SiNNs revealed a red-shift (?8.26 cm-1) in the first-order transversal band as the average diameter of NNs are decrease from 69 to 57 nm. Our systematic method for synthesis and characterization may contribute toward the development of SiNNs based optoelectronics.

  6. Charge and Induced Magnetic Structures of Au Layers in Fe/Au Bilayer and Fe/Au/Fe Trilayer Films by Resonant X-ray Magnetic Reflectivity at the Au L3 Absorption Edge

    NASA Astrophysics Data System (ADS)

    Hosoito, Nobuyoshi; Ohkochi, Takuo; Kodama, Kenji; Suzuki, Motohiro

    2014-02-01

    It is known that spin polarization induced in the Au layers of Fe/Au multilayers which show interlayer exchange coupling consists of an interface-concentrated component and a uniformly extended interior component. To investigate the origin of the interior component, magnetic depth profiles of spin polarization induced in the Au layers of Fe (15 Å)/Au (50 Å) bilayer and Fe (15 Å)/Au (50 Å)/Fe (15 Å) trilayer films were investigated with resonant X-ray magnetic reflectivity (RXMR) measurements at the Au L3 absorption edge. After the determination of charge structures, the spin attenuation length for the interior component of the bilayer sample was evaluated to be longer than 15 Å from the analysis of the RXMR pattern. The RXMR pattern of the trilayer sample was not sufficiently reproduced if the magnetic structure of the trilayer sample was assumed to be a simple sum of the magnetic structure obtained from the bilayer sample. Results were discussed based on the quantum well model.

  7. Electric fields and chiral magnetic effect in Cu + Au collisions

    NASA Astrophysics Data System (ADS)

    Deng, Wei-Tian; Huang, Xu-Guang

    2015-03-01

    The non-central Cu + Au collisions can create strong out-of-plane magnetic fields and in-plane electric fields. By using the HIJING model, we study the general properties of the electromagnetic fields in Cu + Au collisions at 200 GeV and their impacts on the charge-dependent two-particle correlator γq1q2 = < cos ⁡ (ϕ1 +ϕ2 - 2ψRP) > (see main text for definition) which was used for the detection of the chiral magnetic effect (CME). Compared with Au + Au collisions, we find that the in-plane electric fields in Cu + Au collisions can strongly suppress the two-particle correlator or even reverse its sign if the lifetime of the electric fields is long. Combining with the expectation that if γq1q2 is induced by elliptic-flow driven effects we would not see such strong suppression or reversion, our results suggest to use Cu + Au collisions to test CME and understand the mechanisms that underlie γq1q2.

  8. Thermal stability of Mo/Au bilayers for TES applications

    NASA Astrophysics Data System (ADS)

    Parra-Borderías, María; Fernández-Martínez, Iván; Fàbrega, Lourdes; Camón, Agustín; Gil, Oscar; González-Arrabal, Raquel; Sesé, Javier; Costa-Krämer, José Luis; Warot-Fonrose, Bénédicte; Serin, Virginie; Briones, Fernando

    2012-09-01

    Mo/Au bilayers are among the most suitable materials to be used as transition-edge sensors (TES) in cryogenic microcalorimeters and bolometers, developed, among other fields, for space missions. For this purpose the thermal stability of TES at temperatures below 150 °C is a critical issue. We report on the dependence of functional properties (superconducting critical temperature, residual resistance and α) as well as on microstructure, chemical composition and interface quality for optimized high quality Mo/Au bilayers on annealing temperature and time. Data show that the functional properties of the bilayers remain stable at T < 150 °C, but changes in microstructure, interface quality and functional properties were observed for layers heated at T ≥ 200 °C. Microstructural and chemical composition data suggest that the measured changes in residual resistance ratio (RRR) and TC at T ≥ 200 °C are mainly due to an increase in the average Au grain size and to Au migration along the Mo grain boundaries at the Au/Mo interface. A way to stabilize the functional properties of the Mo/Au bilayers against temperature enhancements is proposed.

  9. Competition between Hexagonal and Tetragonal Hexabromobenzene Packing on Au(111).

    PubMed

    Huang, Han; Tan, Zhiyu; He, Yanwei; Liu, Jian; Sun, Jiatao; Zhao, Kang; Zhou, Zhenhong; Tian, Guo; Wong, Swee Liang; Wee, Andrew Thye Shen

    2016-03-22

    Low-temperature scanning tunneling microscope investigations reveal that hexabromobenzene (HBB) molecules arrange in either hexagonally closely packed (hcp) [Formula: see text] or tetragonal [Formula: see text] structure on Au(111) dependent on a small substrate temperature difference around 300 K. The underlying mechanism is investigated by density functional theory calculations, which reveal that substrate-mediated intermolecular noncovalent C-Br···Br-C attractions induce hcp HBB islands, keeping the well-known Au(111)-22×√3 reconstruction intact. Upon deposition at 330 K, HBB molecules trap freely diffusing Au adatoms to form tetragonal islands. This enhances the attraction between HBB and Au(111) but partially reduces the intermolecular C-Br···Br-C attractions, altering the Au(111)-22×√3 reconstruction. In both cases, the HBB molecule adsorbs on a bridge site, forming a ∼15° angle between the C-Br direction and [112̅]Au, indicating the site-specific molecule-substrate interactions. We show that the competition between intermolecular and molecule-substrate interactions determines molecule packing at the subnanometer scale, which will be helpful for crystal engineering, functional materials, and organic electronics. PMID:26905460

  10. Formation, Migration, and Reactivity of Au-CO Complexes on Gold Surfaces.

    PubMed

    Wang, Jun; McEntee, Monica; Tang, Wenjie; Neurock, Matthew; Baddorf, Arthur P; Maksymovych, Petro; Yates, John T

    2016-02-10

    We report experimental as well as theoretical evidence that suggests Au-CO complex formation upon the exposure of CO to active sites (step edges and threading dislocations) on a Au(111) surface. Room-temperature scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy, transmission infrared spectroscopy, and density functional theory calculations point to Au-CO complex formation and migration. Room-temperature STM of the Au(111) surface at CO pressures in the range from 10(-8) to 10(-4) Torr (dosage up to 10(6) langmuir) indicates Au atom extraction from dislocation sites of the herringbone reconstruction, mobile Au-CO complex formation and diffusion, and Au adatom cluster formation on both elbows and step edges on the Au surface. The formation and mobility of the Au-CO complex result from the reduced Au-Au bonding at elbows and step edges leading to stronger Au-CO bonding and to the formation of a more positively charged CO (CO(δ+)) on Au. Our studies indicate that the mobile Au-CO complex is involved in the Au nanoparticle formation and reactivity, and that the positive charge on CO increases due to the stronger adsorption of CO at Au sites with lower coordination numbers. PMID:26754257

  11. A first look at Au+Au collisions at RHIC energies using the PHOBOS detector.

    SciTech Connect

    Back, B. B.; George, N.; Wousmaa, A. H.; Baker, M. D.; Barton, D. S.; PHOBOS Collaboration; Physics

    2003-05-01

    The PHOBOS detector has been used to study Au + Au collisions at {radical}sNN = 56,130, and 200 GeV Several global observables have been measured and the results are compared with theoretical models. These observables include the charged-particle multiplicity measured as a function of beam energy, pseudo-rapidity, and centrality of the collision. A unique feature of the PHOBOS detector is its almost complete angular coverage such that these quantities can be studied over a pseudo-rapidity interval of |{eta}|{<=}5.4. This allows for an almost complete integration of the total charged particle yield, which is found to be about N{sub ch}{sup tot} = 4200 {+-}470 at {radical}sNN = 130 GeV and N{sub ch}{sup tot} = 5300 {+-}530 at {radical}sNN = 200 GeV. The ratio of anti-particles to particles emitted in the mid-rapidity region has also been measured using the PHOBOS magnetic spectrometer. Of particular interest is the ratio of anti-protons to protons in the mid-rapidity region, which was found to be (i.e.921-1) at {radical}sNN = 130 GeV. This high value suggests that an almost baryon-free region has been produced in the collisions.

  12. Thermal description of particle production in Au-Au collisions at RHIC energies (STAR)

    NASA Astrophysics Data System (ADS)

    Tawfik, A.; Abbas, E.

    2015-07-01

    The hadron ratios measured in central Au-Au collisions are analysed by means of Hadron Resonance Gas (HRG) model over a wide range of nucleon-nucleon center-of-mass energies, √ s NN = 7.7-200 GeV as offered by the RHIC Beam Energy Scan I (BES-I) (STAR Collaboration). The temperature and baryon chemical potential are deduced from fits of experimental ratios to thermal model calculations assuming chemical equilibrium. We find that the resulting freeze-out parameters using single hard-core value and point-like constituents of HRG are identical. This implies that the excluded-volume comes up with no effect on the extracted parameters. We compare the results with other studies and with the lattice QCD calculations. Various freeze-out conditions are confronted with the resulting data set. The effect of including new resonances is also analysed. At vanishing chemical potential, a limiting temperature was estimated, T lim = 158.5 ± 3 MeV.

  13. RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN

    SciTech Connect

    Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

  14. Azimuthal anisotophy in U + U and Au + Au collisions at RHIC

    SciTech Connect

    Adamczyk, L.

    2015-11-24

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2} and v2{4}, for charged hadrons from U+U collisions at √SNN = 193 GeV and Au+Au collisions at √SNN = 200 GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. As a result, we also show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  15. Azimuthal anisotophy in U + U and Au + Au collisions at RHIC

    DOE PAGESBeta

    Adamczyk, L.

    2015-11-24

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2} and v2{4}, for charged hadrons from U+U collisions at √SNN = 193 GeV and Au+Au collisions at √SNN = 200 GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. As a result, we alsomore » show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.« less

  16. QUELS FUTURS TRAITEMENTS POUR LA DEPENDANCE AU TABAC ET AU CANNABIS?

    PubMed Central

    LE FOLL, Bernard; JUSTINOVA, Zuzana; TANDA, Gianlugi; GOLDBERG, Steven R.

    2009-01-01

    RESUME Plus de trois millions de morts sont attribués au tabagisme dans le monde par an, et l’usage de tabac est en progression dans les pays en voie de développement. L’usage de tabac est donc une des rares causes de mortalité qui augmente, avec une prévision de plus de 10 millions de morts par an dans 30–40 ans. Le cannabis ou marijuana est la drogue illicite la plus consommée dans le monde et il n’y a actuellement pas de traitement disponible. Bien que les systèmes dopaminergiques jouent un rôle central dans les effets renforçants des drogues, d’autres systèmes sont impliqués. Nous présentons ici des résultats récents obtenus avec des antagonistes des récepteurs cannabinoides CB1, des récepteurs D3 de la dopamine et des récepteurs opioïdes. Ces antagonistes qui modulent de façon directe ou indirecte la transmission dopaminergique cérébrale représentent des approches prometteuses pour le traitement du tabagisme ou de la dépendance au cannabis. Ces approches sont à valider dans des essais cliniques. PMID:18663981

  17. Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Xu, H.; Xu, Z.; Xu, J.; Yang, S.; Yang, Y.; Yang, Y.; Yang, C.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Y.; Zhang, J.; Zhang, J.; Zhang, S.; Zhang, S.; Zhang, Z.; Zhang, J. B.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-03-01

    We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au +Au collisions for energies ranging from √{sN N }=7.7 to 200 GeV. The third harmonic v32{2 }=⟨cos 3 (ϕ1-ϕ2)⟩ , where ϕ1-ϕ2 is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δ η =η1-η2 . Nonzero v32{2 } is directly related to the previously observed large-Δ η narrow-Δ ϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v32{2 } persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v32{2 } is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v32{2 } for central collisions shows a minimum near √{sN N }=20 GeV .

  18. Phospholipid Encapsulated AuNR@Ag/Au Nanosphere SERS Tags with Environmental Stimulus Responsive Signal Property.

    PubMed

    Su, Xueming; Wang, Yunqing; Wang, Wenhai; Sun, Kaoxiang; Chen, Lingxin

    2016-04-27

    Surface-enhanced Raman scattering (SERS) tags draw much attention due to the ultrasensitivity and multiplex labeling capability. Recently, a new kind of SERS tags was rationally designed by encapsulating metal nanoparticles with phospholipid bilayers, showing great potential in theranostics. The lipid bilayer coating confers biocompatibility and versatility to changing surface chemistry of the tag; however, its "soft" feature may influence SERS signal stability, which is rarely investigated. Herein, we prepared phospholipid-coated AuNR@Ag/Au nanosphere SERS tags by using three different kinds of Raman reporters, i.e., thio-containing 4-nitrothiophenol (NT), nitrogen-containing hydrophobic chromophore cyanine 7 monoacid (Cy7), and alkyl chain-chromophore conjugate 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine (DiD). It was found that signal responses were different upon additional stimulation which the tags may encounter in theranostic applications including the presence of detergent Triton X-100, lipid membrane, and photothermal treatment. Living-cell imaging also showed signal changing distinction. The different SERS signal performances were attributed to the different Raman reporter releasing behaviors from the tags. This work revealed that Raman reporter structure determined signal stability of lipid-coated SERS tags, providing guidance for the design of stimulus responsive tags. Moreover, it also implied the potential of SERS technique for real time drug release study of lipid based nanomedicine. PMID:27052206

  19. Influence of Bottom Quark Jet Quenching on Single ElectronTomography of Au+Au

    SciTech Connect

    Djordjevic, Magdalena; Gyulassy, Miklos; Vogt, Ramona; Wicks, Simon

    2005-07-12

    High transverse momentum single (non-photonic) electrons are shown to be sensitive to the stopping power of both bottom, b, and charm, c, quarks in AA collisions. We apply the DGLV theory of radiative energy loss to predict c and b quark jet quenching and compare the FONLL and PYTHIA heavy flavor fragmentation and decay schemes. We show that single electrons in the p{sub T} = 5-10 GeV range are dominated by the decay of b quarks rather than the more strongly quenched c quarks in Au+Au collisions at {radical}s = 200 AGeV. The smaller b quark energy loss, even for extreme opacities with gluon rapidity densities up to 3500, is predicted to limit the nuclear modification factor, R{sub AA}, of single electrons to the range R{sub AA} {approx} 0.5-0.6, in contrast to previous predictions of R{sub AA} {le} 0.2-0.3 based on taking only c quark jet fragmentation into account.

  20. Dielectron Mass Spectra from Au +Au Collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-07-01

    We report the STAR measurements of dielectron (e+e-) production at midrapidity (|yee|<1) in Au +Au collisions at √sNN =200 GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like) GeV /c2. The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

  1. DRIFTS-QMS study of room temperature CO oxidation on Au/SiO2 catalyst: nature and role of different Au species

    SciTech Connect

    Wu, Zili; Zhou, Shenghu; Zhu, Haoguo; Dai, Sheng; Overbury, Steven {Steve} H

    2009-01-01

    The nature and role of different Au species on a Au/SiO2 catalyst in room temperature (rt) CO oxidation have been studied by operando diffuse reflectance infrared spectroscopy (DRIFT) coupled with quadruple mass spectrometry (QMS). It has shown that different pretreatments (oxidative and reductive) of Au/SiO2 have significant effect on the nature of Au species and thus the CO oxidation performance. High temperature (500 C) O2-treatment leads to cationic Au species which is inactive for rt CO oxidation. Reductive treatment (either H2 or CO) results in metallic Au species that are immediately active for rt CO oxidation. Furthermore, CO oxidation activity is found in good correlation with the reduction degree of Au species, a clear indication of the essential role of metallic Au species played in rt CO oxidation. The accompanying slight deactivation with the oxidation of metallic Au species on reductively treated Au/SiO2 in CO oxidation suggests that cationic Au species may play a negative role in rt CO oxidation. The effect of water in rt CO oxidation on Au/SiO2 was also investigated. Two positive roles played by water in CO oxidation have been identified: activation of O2 and reduction of cationic Au species.

  2. Scaling properties of proton and antiproton production in sqrt[s(NN)]=200 GeV Au+Au collisions.

    PubMed

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, G; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, L D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; Van Hecke, H W; Velkovska, J; Velkovsky, M; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2003-10-24

    We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at sqrt[s(NN)]=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5Au+Au, p+p, and e(+)e(-) collisions. This enhancement is limited to p(T)<5 GeV/c as deduced from the ratio of charged hadrons to pi(0) measured in the range 1.5

  3. Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

    NASA Technical Reports Server (NTRS)

    Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.; Chu, Y. Y.; Cianciolo, V.; Cole, B. A.; Crawford, H. J.; Cumming, J. B.; Debbe, R.; Dunlop, J. C.; Eldredge, W.; Engelage, J.; Fung, S.-Y.

    1997-01-01

    Antiproton production in heavy ion collisions reflects subtle interplay between initial production and absorption by nucleons. Because the AGS energies (10--20 A(center-dot)GeV/c) are close to the antiproton production threshold, antiproton may be sensitive to cooperative processes such as QGP and hadronic multi-step processes. On the other hand, antiproton has been proposed as a probe of baryon density due to large N(anti N) annihilation cross sections. Cascade models predict the maximum baryon density reaches about 10 times the normal nucleus density in central Au+Au collisions, where the strong antiproton absorption is expected. In this paper, the authors show systematic studies of antiproton production from p+A to Au+Au collisions.

  4. Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV.

    PubMed

    Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Alford, J; Anderson, B D; Anson, C D; Arkhipkin, D; Averichev, G S; Balewski, J; Barnby, L S; Beavis, D R; Behera, N K; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Braidot, E; Brandin, A V; Bridgeman, A; Brovko, S G; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Sánchez, M Calderón de la Barca; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, P; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Leyva, A Davila; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; de Souza, R Derradi; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunlop, J C; Efimov, L G; Elnimr, M; Engelage, J; Eppley, G; Estienne, M; Eun, L; Evdokimov, O; Fatemi, R; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Geurts, F; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O G; Grosnick, D; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heinz, M; Heppelmann, S; Hirsch, A; Hjort, E; Hoffmann, G W; Hofman, D J; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Jacobs, P; Jacobs, W W; Jena, C; Jin, F; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Kizka, V; Klein, S R; Knospe, A G; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kouchpil, V; Kravtsov, P; Krueger, K; Krus, M; Kumar, L; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, L; Li, N; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Liu, H; Liu, J; Ljubicic, T; Llope, W J; Longacre, R S; Lu, Y; Lukashov, E V; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Manweiler, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mitrovski, M K; Mohammed, Y; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Mustafa, M K; Naglis, M; Nandi, B K; Nayak, T K; Nelson, J M; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Pei, H; Peitzmann, T; Perkins, C; Peryt, W; Pile, P; Planinic, M; Ploskon, M A; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Potukuchi, B V K S; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ruan, L; Rusnak, J; Sahoo, N R; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schaub, J; Schmah, A M; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shah, N; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Shou, Q Y; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Steadman, S G; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; de Toledo, A Szanto; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Tlusty, D; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Witzke, W; Wu, Y F; Xiao, Z; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J B; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y

    2012-02-17

    We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions. PMID:22401196

  5. Strangeness Enhancement in Cu-Cu and Au-Au Collisions at sNN=200GeV

    NASA Astrophysics Data System (ADS)

    Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anderson, B. D.; Anson, C. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barnby, L. S.; Beavis, D. R.; Behera, N. K.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Brovko, S. G.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Calderón de La Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Davila Leyva, A.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Estienne, M.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Geurts, F.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O. G.; Grosnick, D.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Hofman, D. J.; Huang, B.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jena, C.; Jin, F.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Kizka, V.; Klein, S. R.; Knospe, A. G.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lu, Y.; Lukashov, E. V.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pei, H.; Peitzmann, T.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schaub, J.; Schmah, A. M.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Solanki, D.; Sorensen, P.; Desouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Steadman, S. G.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Witzke, W.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, J. B.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.

    2012-02-01

    We report new STAR measurements of midrapidity yields for the Λ, Λ¯, KS0, Ξ-, Ξ¯+, Ω-, Ω¯+ particles in Cu+Cu collisions at sNN=200GeV, and midrapidity yields for the Λ, Λ¯, KS0 particles in Au+Au at sNN=200GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

  6. MMENT>Computational study of complete methanol dehydrogenation on Au(100) and Au(310) surfaces: Dominant role of atomic oxygen

    NASA Astrophysics Data System (ADS)

    Hussain, A.; Shah, S. H.

    2014-02-01

    Methanol dehydrogenation to CO and H2 has been systematically investigated on Au(100) and Au(310) surfaces using density functional theory (DFT). All possible intermediates involved are calculated. Methanol and formaldehyde being saturated molecules adsorb weakly on both the surfaces. The thermochemistry and kinetics of the decomposition via sequential hydrogen abstraction are both found to be highly unfavorable for these species. Nevertheless, atomic oxygen pre-covered surfaces substantially enhance CH3OH and CH2O (resulting in CH2O2 complex formation) interaction with Au and offer weak activation barrier for methanol disintegration into CH3O and H. On the other hand, methoxy, formyl, and atomic hydrogen are predicted to make strong chemical bonds with the clean Au surfaces. The abstraction of hydrogen from the methoxy intermediate on bare gold surfaces is practical, while formyl splits instantaneously during optimization. A feasible mechanism on oxygen pre-covered surfaces for complete methanol dehydrogenation has been presented.

  7. A TBET-based ratiometric probe for Au(3+) and its application in living cells.

    PubMed

    Han, Xiang; Zhao, Lei; Wang, Dong-En; Xu, Juan; Zhang, Longlong; Yuan, Mao-Sen; Tu, Qin; Wang, Jinyi

    2016-02-01

    In this paper, we designed and synthesized a novel TBET-based ratiometric fluorescent chemodosimeter, RH-Au, for Au(3+). It was found that the probe RH-Au displayed highly selective, sensitive and naked-eye detection upon the addition of Au(3+). The probe RH-Au can be used in the pH range 6.0-7.5 and the detection limit was determined to be as low as 2.91 nM (0.57 ppb). We also demonstrated a successful application of imaging Au(3+) in living cells using RH-Au. PMID:26662283

  8. Discovery of a large dust disk around the nearby star AU Microscopii.

    PubMed

    Kalas, Paul; Liu, Michael C; Matthews, Brenda C

    2004-03-26

    We present the discovery of a circumstellar dust disk surrounding AU Microscopii (AU Mic, GJ 803, HD 197481). This young M star at 10 parsec has the same age and origin as beta Pictoris, another nearby star surrounded by a dust disk. The AU Mic disk is detected between 50 astronomical units (AU) and 210 AU radius, a region where dust lifetimes exceed the present stellar age. Thus, AU Mic is the nearest star where we directly observe the solid material required for planet formation. Because 85% of stars are M-type, the AU Mic disk provides new clues on how the majority of planetary systems might form and evolve. PMID:14988511

  9. Au-Sn SLID Bonding: A Reliable HT Interconnect and Die Attach Technology

    NASA Astrophysics Data System (ADS)

    Tollefsen, Torleif André; Larsson, Andreas; Taklo, Maaike Margrete Visser; Neels, Antonia; Maeder, Xavier; Høydalsvik, Kristin; Breiby, Dag W.; Aasmundtveit, Knut

    2013-04-01

    Au-Sn solid-liquid interdiffusion (SLID) bonding is an established reliable high temperature (HT) die attach and interconnect technology. This article presents the life cycle of an optimized HT Au-Sn SLID bond, from fabrication, via thermal treatment, to mechanical rupture. The layered structure of a strong and uniform virgin bond was identified by X-ray diffraction to be Au/ζ (Au0.85Sn0.15)/Au. During HT exposure, it was transformed to Au/β (Au1.8Sn0.2)/Au. After HT exposure, the die shear strength was reduced by 50 pct, from 14 Pa to 70 MPa, which is still remarkably high. Fractographic studies revealed a change in fracture mode; it was changed from a combination of adhesive Au/Ni and cohesive SiC fracture to a cohesive β-phase fracture. Design rules for high quality Au-Sn SLID bonds are given.

  10. Au(n)Hg(m) clusters: mercury aurides, gold amalgams, or van der Waals aggregates?

    PubMed

    Zaleski-Ejgierd, Patryk; Pyykkö, Pekka

    2009-11-12

    The class of bimetallic clusters, Au(n)M(m) (M = Zn, Cd, Hg), is calculated at the ab initio level using the DFT, RI-MP2, and CCSD(T) methods. For the triatomic Au2M (M = Zn, Cd), the auride-type linear Au-M-Au structures are preferred; for Au2Hg, the linear Au-Au-Hg "amalgam" is preferred. The mixed cation [HgAuHg]+, an analog of the known solid-state species Hg32+, is predicted. For larger Au(n)Hg(m) clusters, the results are similar to the isoelectronic Au(n)M- anions. Several local minima and transition states are identified. All are found to be planar. PMID:19228004

  11. Measurement of Inclusive Antiprotons from Au+Au Collisions at (sNN) = 130 GeV

    NASA Astrophysics Data System (ADS)

    Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bichsel, H.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Boucham, A.; Brandin, A.; Cadman, R. V.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chattopadhyay, S.; Chen, M. L.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Demello, M.; Deng, W. S.; Derevschikov, A. A.; Didenko, L.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grabski, J.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heffner, M.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Igo, G.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E.; Kaneta, M.; Kaplan, M.; Keane, D.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Konstantinov, A. S.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamas-Valverde, J.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; Levine, M. J.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Locurto, G.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lynn, D.; Majka, R.; Margetis, S.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mitchell, J.; Moiseenko, V. A.; Moore, C. F.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Mutchler, G. S.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Platner, E.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Radomski, S.; Rai, G.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Rykov, V.; Sakrejda, I.; Sandweiss, J.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schüttauf, A.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shestermanov, K. E.; Shimanskii, S. S.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Snellings, R.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Šumbera, M.; Symons, T. J.; Szanto de Toledo, A.; Szarwas, P.; Takahashi, J.; Tang, A. H.; Thomas, J. H.; Thompson, M.; Tikhomirov, V.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tokarev, M.; Tonjes, M. B.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; van Buren, G.; Vandermolen, A. M.; Vanyashin, A.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Voloshin, S. A.; Wang, F.; Ward, H.; Watson, J. W.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitten, C.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, W. M.; Zoulkarneev, R.; Zubarev, A. N.

    2001-12-01

    We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at (sNN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25

  12. Photoelectron Spectroscopy of BiAu(-) and BiBO(-): Further Evidence of the Analogy between Au and Boronyl.

    PubMed

    Jian, Tian; Lopez, Gary V; Wang, Lai-Sheng

    2016-03-01

    Boronyl (BO) is a monovalent σ radical with a B≡O triple bond. Its chemistry has remained relatively unknown, though analogy has been established for BO with monovalent atoms, such as H or Au. Here we report a photoelectron spectroscopic study of BiAu(-) and BiBO(-), showing further evidence of the analogy between Au and BO. The photoelectron spectra of BiAu(-) and BiBO(-) are found to be similar, suggesting that they possess similar electronic structure and chemical bonding. The electron affinities of BiAu and BiBO are measured to be 1.38(4) and 1.84(3) eV, respectively. The ground states of both BiAu and BiBO are shown to be a triplet (X (3)Σ(-)). In addition, vibrational structures are resolved in the spectra of BiBO(-). Two vibrational frequencies at 320(30) and 1860(50) cm(-1) are measured for the ground state of BiBO, corresponding to the Bi-B and B-O stretching modes, respectively. The low-lying electronic excited states of BiAu and BiBO are also found to be similar: their first four excited states are A (1)Δ, B (1)Σ(+), C (3)Π, and D (1)Π, with excitation energies at 0.71, 1.29, 2.54, and 2.67 eV for BiAu and 0.63, 1.26, 3.68, and 3.82 eV for BiBO, respectively, above the (3)Σ(-) ground state. Weak photoelectron features related to two-electron detachment transitions are also observed for both anions because of strong electron correlation effects in the ground state of the anions. PMID:26436561

  13. Measurement of J/? Azimuthal Anisotropy in Au+Au Collisions at ?sNN=200 GeV

    DOE PAGESBeta

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; et al

    2013-08-02

    The measurement of J/? azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at ?sNN>/sub>=200 GeV. The measured J/? elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/? particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

  14. Hadron Production in Au + Au Collisions at 4 A GeV from AGS-E866

    NASA Astrophysics Data System (ADS)

    Chujo, T.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.; Chi, C.; Chu, Y. Y.; Cianciolo, V.; Cole, B. A.; Crawford, H. J.; Cumming, J. B.; Debbe, R.; Dunlop, J. C.; Eldredge, W.; Engelage, J.; Fung, S.; Gaardhoje; Garcia, E.; Gonin, M.; Gushue, S.; Hamagaki, H.; Hansen, A.; Hansen, L.; Hayano, R. S.; Heintzelman, G.; Homma, S.; Judd, E.; Kaneko, H.; Kang, J.; Kim, E.; Kumagai, A.; Kurita, K.; Lee, J.; Levine, M. J.; Luke, J.; Miake, Y.; Mignerey, A.; Moskowitz, B.; Moulson, M.; Müentz, C.; Nagamiya, S.; Namboodiri, M. N.; Ogilvie, C.; Olness, J.; Remsberg, L. P.; Sako, H.; Sangster, T. C.; Seto, R.; Shea, J.; Shigaki, K.; Soltz, R.; Steadman, S. G.; Stephans, G. S. F.; Tannenbaum, M. J.; Thomas, J. H.; Ueno-Hayashi, S.; K, F. V.; Wang, F.; Wang, Y.; Wu, Y.; Xiang, H.; Xu, G. H.; Yagi, K.; Yao, H.; Zajc, W. A.; Zhu, Q.; Zhu, F.

    First measurements of single particle spectra of π±, K+ and p in 197Au + Au collisions at Ekine = 4 GeV per nucleon are presented. Utilizing the 4 A GeV data set from the Forward Spectrometer at the AGS-E866 experiment, transverse mass distributions and rapidity density distributions of π±, K+ and p near the mid-rapidity region are extracted. Preliminary results are compared with those of the microscopic cascade model calculation, RQMD.

  15. Azimuthally sensitive hanbury brown-twiss interferometry in Au + Au collisions sqrt S sub NN = 200 GeV

    SciTech Connect

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj, S.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll, J.; Castillo, J.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grebenyuk, O.; Gronstal, S.; Grosnick, D.; Guertin, S.M.; Gupta, A.; Gutierrez, T.D.; Hallman, T.J.; Hamed, A.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang, L.S.; Hughes, E.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Jiang, H.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaplan, M.; Keane, D.; Khodyrev, V.Yu.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, V.I.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; Kuznetsov, A.A.; Lamont, M.A.C.; et al.

    2004-06-30

    We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii vs. emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.

  16. Strangeness in Au+Au collisions at √sNN = 130 GeV observed with the STAR detector

    NASA Astrophysics Data System (ADS)

    Barnby, Lee S.; STAR Collaboration; Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bichsel, H.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Boucham, A.; Brandin, A.; Cadman, R. V.; Caines, H.; Calderón de la Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chattopadhyay, S.; Chen, M. L.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Deng, W. S.; Derevschikov, A. A.; Didenko, L.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grabski, J.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heffner, M.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Igo, G.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E. G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Konstantinov, A. S.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; LeVine, M. J.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Curto, G. Lo; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lynn, D.; Majka, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mitchell, J.; Moiseenko, V. A.; Moore, C. F.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Radomski, S.; Rai, G.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Rykov, V.; Sakrejda, I.; Sandweiss, J.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schüttauf, A.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shestermanov, K. E.; Shimanskii, S. S.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A. P.; Sugarbaker, E.; Suire, C.; umbera, M.; Symons, T. J. M.; Szanto de Toledo, A.; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, A. H.; Thomas, J. H.; Thompson, M.; Tikhomirov, V.; Tokarev, M.; Tonjes, M. B.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; Vander Molen, A. M.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Voloshin, S. A.; Wang, F.; Ward, H.; Watson, J. W.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Wood, J.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, W. M.; Zoulkarneev, R.; Zubarev, A. N.

    2002-07-01

    The STAR detector has made a variety of measurements of strange and other hadronic species in Au+Au collisions at √sNN = 130 GeV. A comparison of kaon and pion production enables an examination of the systematics of strangeness production with energy by comparing them to lower energy collisions. Anti-baryon to baryon ratios indicate a much reduced net-baryon density and transverse momentum spectra show that a picture of transverse expansion seems appropriate.

  17. Ultrasonic friction power during thermosonic Au and Cu ball bonding

    NASA Astrophysics Data System (ADS)

    Shah, A.; Mayer, M.; Qin, I.; Huynh, C.; Zhou, Y.; Meyer, M.

    2010-08-01

    The ultrasonic friction power during thermosonic ball bonding with Au and Cu wires, both 25 µm in diameter, is derived with an improved method from experimental measurements during the bonding process. Experimental data include the current delivered to the ultrasonic transducer and the tangential force measured using piezoresistive microsensors integrated close to the Al bonding pad. The improvement results from a new, more accurate method to derive the mechanical compliance of the ultrasonic system. The method employs a bond process modification in which the ultrasonic current is ramped up sequentially in three steps. In the first two steps, the ultrasonic current is set to levels that are too low to cause sliding. The bonding takes place during the third step, when the current is ramped up to the optimum value required for making good quality bonds. The ultrasonic compliance values are derived from the first two steps and are 8.2 ± 0.5 µm N-1 and 7.7 ± 0.5 µm N-1 for the Au and Cu processes, respectively. These values are determined within an average error estimate of ±6%, substantially lower than the ±10% estimated with a previously reported method. The ultrasonic compliance in the case of Au is 6% higher due to the lower elastic modulus of Au compared with that of Cu. Typical maximum values of relative sliding amplitude of ultrasonic friction at the interface are 655 nm and 766 nm for the Au and Cu processes. These values are 81% of the free-air vibration amplitude of the bonding capillary tip for the respective ultrasonic current settings. Due to bond growth, which damps relative motion between the ball and the pad, the final relative amplitude at the bond interface is reduced to 4% of the equivalent free-air amplitude. Even though the maximum value of relative amplitude is 17% higher in the Cu process compared with the Au process, the average total interfacial sliding is 519 µm in the Cu process, which is 31% lower than that in the Au process (759 µm). The average maximum interfacial friction power is 10.3 mW and 16.9 mW for the Au and Cu ball bonding processes, respectively. The total sliding friction energy delivered to the bond is 48.5 µJ and 49.4 µJ for the Au and Cu ball bonding cases, respectively. These values result in average friction energy densities of 50.3 mJ mm-2 and 54.8 mJ mm-2 for Au and Cu ball bonding, respectively.

  18. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    SciTech Connect

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au to replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.

  19. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    DOE PAGESBeta

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au tomore » replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.« less

  20. Heterojunction metal-oxide-metal Au-Fe{sub 3}O{sub 4}-Au single nanowire device for spintronics

    SciTech Connect

    Reddy, K. M. Punnoose, Alex; Hanna, Charles; Padture, Nitin P.

    2015-05-07

    In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe{sub 3}O{sub 4} interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current–voltage (I-V) characteristics of a single Au-Fe{sub 3}O{sub 4}-Au nanowire have exhibited Ohmic behavior. Anomalous positive magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe{sub 3}O{sub 4} phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe{sub 3}O{sub 4} and well defined electrode contact metal (Au)–magnetite interface, which helps in attaining high spin polarized current.

  1. Amperometric Immunosensor for Carbofuran Detection Based on MWCNTs/GS-PEI-Au and AuNPs-Antibody Conjugate

    PubMed Central

    Zhu, Ying; Cao, Yaoyao; Sun, Xia; Wang, Xiangyou

    2013-01-01

    In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab) and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD), ultraviolet and visible absorption spectroscopy (UV-vis) and scanning electron microscopy (SEM), respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3). The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication. PMID:23604029

  2. Heterojunction metal-oxide-metal Au-Fe3O4-Au single nanowire device for spintronics

    NASA Astrophysics Data System (ADS)

    Reddy, K. M.; Padture, Nitin P.; Punnoose, Alex; Hanna, Charles

    2015-05-01

    In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe3O4 interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current-voltage (I-V) characteristics of a single Au-Fe3O4-Au nanowire have exhibited Ohmic behavior. Anomalous positive magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe3O4 phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe3O4 and well defined electrode contact metal (Au)-magnetite interface, which helps in attaining high spin polarized current.

  3. Versatile and efficient catalysts for energy and environmental processes: Mesoporous silica containing Au, Pd and Au-Pd

    NASA Astrophysics Data System (ADS)

    da Silva, Anderson G. M.; Fajardo, Humberto V.; Balzer, Rosana; Probst, Luiz F. D.; Lovón, Adriana S. P.; Lovón-Quintana, Juan J.; Valença, Gustavo P.; Schreine, Wido H.; Robles-Dutenhefner, Patrícia A.

    2015-07-01

    We described a versatile approach for the synthesis of Au/MCM-41, Pd/MCM-41 and Au-Pd/MCM-41 by the direct incorporation of the noble metals into the MCM-41 framework. The structural, textural and chemical properties were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), N2-adsorption (BET and BJH methods), H2-chemisorption, small angle X-ray scattering (SAXS), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The nanomaterials, being comprised of Au, Pd and Au-Pd nanoparticles and possessing high surface areas were applied as versatile and efficient catalysts in benzene, toluene and o-xylene (BTX) oxidation and in the steam reforming of ethanol for hydrogen production. The results revealed that the catalytic behavior in both processes was influenced by the experimental conditions and the nature of the catalyst employed. The Au-Pd/MCM-41 catalyst was the most active in the BTX total oxidation. On the basis of characterization data, it was proposed that the close contact between Pd and Au and the higher dispersion of Pd may be responsible for the enhanced activity of the bimetallic catalyst. However, the strong interaction between the noble metals did not improve the performance of the bimetallic catalyst in ethanol steam reforming, the Pd/MCM-41 catalyst being the most active and selective for hydrogen production.

  4. Dynamical evolution of interplanetary magnetic fields and flows between 0.3 AU and 8.5 AU - Entrainment

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Schwenn, R.; Rosenbauer, H.

    1983-01-01

    An analysis is presented of the radial evolution of interplanetary flows and associated magnetic fields between 0.3 AU and 8.5 AU using data from Helios 1 and B Voyager 1, respectively. The results indicate that in moving to 8 AU the largest corotating streams swept up the slower flows and shocks into a relatively thin region in which they coalesced to form a single large-amplitude compression. As a result of this process, referred to as entrainment, memory of the sources and flow configurations near the sun is lost, while small-scale features are erased as the flows move outward and energy is transferred from small scales to large scales.It is concluded that in the outer solar system the structure of the solar wind may be dominated by large scale pressure waves separated by several AU, while beyond several AU most of the compression waves are no longer driven by streams, and the compression waves expand freely. At large distances (greater than 25 AU) these compression waves will have interacted extensively with one another producing another state of the solar wind, with fewer large-scale nonuniformities and more small-scale nonuniformities.

  5. Amperometric immunosensor for carbofuran detection based on MWCNTs/GS-PEI-Au and AuNPs-antibody conjugate.

    PubMed

    Zhu, Ying; Cao, Yaoyao; Sun, Xia; Wang, Xiangyou

    2013-01-01

    In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab) and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD), ultraviolet and visible absorption spectroscopy (UV-vis) and scanning electron microscopy (SEM), respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3). The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication. PMID:23604029

  6. Disappearance of back-to-back high p {sub T} hadron correlations in central Au+Au collisions at {radical}s{sub NN} = 200 GeV

    SciTech Connect

    Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B.D.; Anderson, M.; Averichev, G.S.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Caines, H.; Calderon de la Barca Sanchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Corral, M.M.; Cramer, J.G.; Crawford, H.J.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Draper, J.E.; Dunin, V.B.; Dunlop, J.C.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Humanic, T.J.; Igo, G.J.; Ishihara, A.; Ivanshin, Yu.I.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Kollegger, T.; Konstantinov, A.S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; Kuznetsov, A.A.; Lakehal-Ayat, L.; Lamont, M.A.C.; Landgraf, J.M.; Lange, S.; Lansdell, C.P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Leontiev, V.M.; LeVine, M.J.; Li , Q.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q.J.; Ljubicic, T.; Llope, W.J.; LoCurto, G.; et al.

    2002-10-25

    Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at = {radical}s{sub NN} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

  7. Jet-hadron correlations in √[s(NN)]=200  GeV p+p and central Au+Au collisions.

    PubMed

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