WorldWideScience

Sample records for extremely large size

  1. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    IL, Kochevar IE, Redmond RW. Large extremity peripheral nerve repair. Military Health System Research Symposium (MHSRS) Fort Lauderdale, FL. August...some notable discoveries that may impact military health care in the near future. There is a clear need in military medicine to improve outcomes in...membranes or “caul” intact was considered extremely lucky. Children were gifted with life-long happiness , the ability to see spirits, and protection

  2. Large litter sizes

    DEFF Research Database (Denmark)

    Sandøe, Peter; Rutherford, K.M.D.; Berg, Peer

    2012-01-01

    This paper presents some key results and conclusions from a review (Rutherford et al. 2011) undertaken regarding the ethical and welfare implications of breeding for large litter size in the domestic pig and about different ways of dealing with these implications. Focus is primarily on the direct...... adverse consequences for animal welfare of Danish breeding for large litter sizes due to increased piglet mortality and the subsequent attempts to reverse these consequences by breeding for number of live piglets at day five rather than number of piglets born. By this change of breeding goal it seems...

  3. Large litter sizes

    DEFF Research Database (Denmark)

    Sandøe, Peter; Rutherford, K.M.D.; Berg, Peer

    2012-01-01

    This paper presents some key results and conclusions from a review (Rutherford et al. 2011) undertaken regarding the ethical and welfare implications of breeding for large litter size in the domestic pig and about different ways of dealing with these implications. Focus is primarily on the direct...

  4. Extremal sizes of subspace partitions

    CERN Document Server

    Heden, Olof; Nastase, Esmeralda; Sissokho, Papa

    2011-01-01

    A subspace partition $\\Pi$ of $V=V(n,q)$ is a collection of subspaces of $V$ such that each 1-dimensional subspace of $V$ is in exactly one subspace of $\\Pi$. The size of $\\Pi$ is the number of its subspaces. Let $\\sigma_q(n,t)$ denote the minimum size of a subspace partition of $V$ in which the largest subspace has dimension $t$, and let $\\rho_q(n,t)$ denote the maximum size of a subspace partition of $V$ in which the smallest subspace has dimension $t$. In this paper, we determine the values of $\\sigma_q(n,t)$ and $\\rho_q(n,t)$ for all positive integers $n$ and $t$. Furthermore, we prove that if $n\\geq 2t$, then the minimum size of a maximal partial $t$-spread in $V(n+t-1,q)$ is $\\sigma_q(n,t)$.

  5. Large Size Telescope Report

    CERN Document Server

    Mazin, D; Teshima, M

    2016-01-01

    The Cherenkov Telescope Array (CTA) observatory will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 photomultiplier tubes and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is ongoing. The installation of the first LST at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain) started in July 2016. In this paper we will outline the technical solutions adopted to f...

  6. Large size telescope report

    Science.gov (United States)

    Mazin, D.; Cortina, J.; Teshima, M.

    2017-01-01

    The Cherenkov Telescope Array (CTA) observatory will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 photomultiplier tubes and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is ongoing. The installation of the first LST at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain) started in July 2016. In this paper we will outline the technical solutions adopted to fulfill the design requirements, present results of element prototyping and describe the installation and operation plans.

  7. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    MB, Roberts AB, Wakersfield LM, de Crombrugghe B. Some recent advances in the chemistry and biology of trans- forming growth factor-beta. J Cell Biol...animal facility and had access to food and water as required. 59 Copyright © 2015 American Society of Plastic Surgeons. Unauthorized reproduction...s): F1 Art : PRS182917 Input-nlm 69 Manuscript 3: Large Gap Nerve Reconstruction Using Acellular Nerve Allografts And Photochemical Tissue

  8. CFRP lightweight structures for extremely large telescopes

    DEFF Research Database (Denmark)

    Jessen, Niels Christian; Nørgaard-Nielsen, Hans Ulrik; Schroll, J.

    2008-01-01

    Telescope structures are traditionally built out of steel. To improve the possibility of realizing the ambitious extremely large telescopes, materials with a higher specific stiffness and a lower coefficient of thermal expansion are needed. An important possibility is Carbon Fibre Reinforced...... Plastic (CFRP). The advantages of using CFRP for the secondary mirror support structure of the European overwhelmingly large telescope are discussed....

  9. SIZE AND SHAPE FACTOR EXTREMES OF SPHEROIDS

    Directory of Open Access Journals (Sweden)

    Daniel Hlubinka

    2011-05-01

    Full Text Available In the paper we consider random prolate (oblate spheroids and their random profiles. The limiting distribution of the extremal characteristics of the spheroids is related to the limiting distribution of the corresponding extremal characteristics of the profiles. The difference between the analysis of the prolate and oblate spheroids is discussed. We propose the possible application of the theoretical results.

  10. Wound size measurement of lower extremity ulcers using segmentation algorithms

    Science.gov (United States)

    Dadkhah, Arash; Pang, Xing; Solis, Elizabeth; Fang, Ruogu; Godavarty, Anuradha

    2016-03-01

    Lower extremity ulcers are one of the most common complications that not only affect many people around the world but also have huge impact on economy since a large amount of resources are spent for treatment and prevention of the diseases. Clinical studies have shown that reduction in the wound size of 40% within 4 weeks is an acceptable progress in the healing process. Quantification of the wound size plays a crucial role in assessing the extent of healing and determining the treatment process. To date, wound healing is visually inspected and the wound size is measured from surface images. The extent of wound healing internally may vary from the surface. A near-infrared (NIR) optical imaging approach has been developed for non-contact imaging of wounds internally and differentiating healing from non-healing wounds. Herein, quantitative wound size measurements from NIR and white light images are estimated using a graph cuts and region growing image segmentation algorithms. The extent of the wound healing from NIR imaging of lower extremity ulcers in diabetic subjects are quantified and compared across NIR and white light images. NIR imaging and wound size measurements can play a significant role in potentially predicting the extent of internal healing, thus allowing better treatment plans when implemented for periodic imaging in future.

  11. Evolution of extreme body size disparity in monitor lizards (Varanus).

    Science.gov (United States)

    Collar, David C; Schulte, James A; Losos, Jonathan B

    2011-09-01

    Many features of species' biology, including life history, physiology, morphology, and ecology are tightly linked to body size. Investigation into the causes of size divergence is therefore critical to understanding the factors shaping phenotypic diversity within clades. In this study, we examined size evolution in monitor lizards (Varanus), a clade that includes the largest extant lizard species, the Komodo dragon (V. komodoensis), as well as diminutive species that are nearly four orders of magnitude smaller in adult body mass. We demonstrate that the remarkable body size disparity of this clade is a consequence of different selective demands imposed by three major habitat use patterns-arboreality, terrestriality, and rock-dwelling. We reconstructed phylogenetic relationships and ancestral habitat use and applied model selection to determine that the best-fitting evolutionary models for species' adult size are those that infer oppositely directed adaptive evolution associated with terrestriality and rock-dwelling, with terrestrial lineages evolving extremely large size and rock-dwellers becoming very small. We also show that habitat use affects the evolution of several ecologically important morphological traits independently of body size divergence. These results suggest that habitat use exerts a strong, multidimensional influence on the evolution of morphological size and shape disparity in monitor lizards.

  12. Genetics of Rapid and Extreme Size Evolution in Island Mice.

    Science.gov (United States)

    Gray, Melissa M; Parmenter, Michelle D; Hogan, Caley A; Ford, Irene; Cuthbert, Richard J; Ryan, Peter G; Broman, Karl W; Payseur, Bret A

    2015-09-01

    Organisms on islands provide a revealing window into the process of adaptation. Populations that colonize islands often evolve substantial differences in body size from their mainland relatives. Although the ecological drivers of this phenomenon have received considerable attention, its genetic basis remains poorly understood. We use house mice (subspecies: Mus musculus domesticus) from remote Gough Island to provide a genetic portrait of rapid and extreme size evolution. In just a few hundred generations, Gough Island mice evolved the largest body size among wild house mice from around the world. Through comparisons with a smaller-bodied wild-derived strain from the same subspecies (WSB/EiJ), we demonstrate that Gough Island mice achieve their exceptional body weight primarily by growing faster during the 6 weeks after birth. We use genetic mapping in large F(2) intercrosses between Gough Island mice and WSB/EiJ to identify 19 quantitative trait loci (QTL) responsible for the evolution of 16-week weight trajectories: 8 QTL for body weight and 11 QTL for growth rate. QTL exhibit modest effects that are mostly additive. We conclude that body size evolution on islands can be genetically complex, even when substantial size changes occur rapidly. In comparisons to published studies of laboratory strains of mice that were artificially selected for divergent body sizes, we discover that the overall genetic profile of size evolution in nature and in the laboratory is similar, but many contributing loci are distinct. Our results underscore the power of genetically characterizing the entire growth trajectory in wild populations and lay the foundation necessary for identifying the mutations responsible for extreme body size evolution in nature. Copyright © 2015 by the Genetics Society of America.

  13. Control challenges for extremely large telescopes

    Science.gov (United States)

    MacMartin, Douglas G.

    2003-08-01

    The next generation of large ground-based optical telescopes are likely to involve a highly segmented primary mirror that must be controlled in the presence of wind and other disturbances, resulting in a new set of challenges for control. The current design concept for the California Extremely Large Telescope (CELT) includes 1080 segments in the primary mirror, with the out-of-plane degrees of freedom actively controlled. In addition to the 3240 primary mirror actuators, the secondary mirror of the telescope will also require at least 5 degree of freedom control. The bandwidth of both control systems will be limited by coupling to structural modes. I discuss three control issues for extremely large telescopes in the context of the CELT design, describing both the status and remaining challenges. First, with many actuators and sensors, the cost and reliability of the control hardware is critical; the hardware requirements and current actuator design are discussed. Second, wind buffeting due to turbulence inside the telescope enclosure is likely to drive the control bandwidth higher, and hence limitations resulting from control-structure-interaction must be understood. Finally, the impact on the control architecture is briefly discussed.

  14. Instrumentation for the California Extremely Large Telescope

    Science.gov (United States)

    Taylor, Keith; McLean, Ian S.

    2003-03-01

    The Phase A study for the California Extremely Large Telescope (CELT) Project has recently been completed. As part of this exercise a working group was set-up to evolve instrumentation strategies matched to the scientific case for the CELT facility. We report here on the proposed initial instrument suite which includes not only massively multiplexed seeing-limited multi-object spectroscopy but also on plans for wide-field adaptive optics fed integral-field spectroscopy and imaging at, or approaching, CELT's diffraction limit.

  15. Extremely Large Images: Considerations for Contemporary Approach

    CERN Document Server

    Kitaeff, Slava; Wu, Chen; Taubman, David

    2013-01-01

    The new widefi?eld radio telescopes, such as: ASKAP,MWA, LOFAR, eVLA and SKA; will produce spectral-imaging data-cubes (SIDC) of unprecedented volumes in the order of hundreds of Petabytes. Servicing such data as images to the end-user may encounter challenges unforeseen during the development of IVOA SIAP. We discuss the requirements for extremely large SIDC, and in this light we analyse the applicability of approach taken in the ISO/IEC 15444 (JPEG2000) standards.

  16. Introducing the refined gravity hypothesis of extreme sexual size dimorphism

    Directory of Open Access Journals (Sweden)

    Corcobado Guadalupe

    2010-08-01

    Full Text Available Abstract Background Explanations for the evolution of female-biased, extreme Sexual Size Dimorphism (SSD, which has puzzled researchers since Darwin, are still controversial. Here we propose an extension of the Gravity Hypothesis (i.e., the GH, which postulates a climbing advantage for small males that in conjunction with the fecundity hypothesis appears to have the most general power to explain the evolution of SSD in spiders so far. In this "Bridging GH" we propose that bridging locomotion (i.e., walking upside-down under own-made silk bridges may be behind the evolution of extreme SSD. A biomechanical model shows that there is a physical constraint for large spiders to bridge. This should lead to a trade-off between other traits and dispersal in which bridging would favor smaller sizes and other selective forces (e.g. fecundity selection in females would favor larger sizes. If bridging allows faster dispersal, small males would have a selective advantage by enjoying more mating opportunities. We predicted that both large males and females would show a lower propensity to bridge, and that SSD would be negatively correlated with sexual dimorphism in bridging propensity. To test these hypotheses we experimentally induced bridging in males and females of 13 species of spiders belonging to the two clades in which bridging locomotion has evolved independently and in which most of the cases of extreme SSD in spiders are found. Results We found that 1 as the degree of SSD increased and females became larger, females tended to bridge less relative to males, and that 2 smaller males and females show a higher propensity to bridge. Conclusions Physical constraints make bridging inefficient for large spiders. Thus, in species where bridging is a very common mode of locomotion, small males, by being more efficient at bridging, will be competitively superior and enjoy more mating opportunities. This "Bridging GH" helps to solve the controversial question of

  17. Optical encryption for large-sized images

    Science.gov (United States)

    Sanpei, Takuho; Shimobaba, Tomoyoshi; Kakue, Takashi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Oikawa, Minoru; Sugie, Takashige; Ito, Tomoyoshi

    2016-02-01

    We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.

  18. Large size space construction for space exploitation

    Science.gov (United States)

    Kondyurin, Alexey

    2016-07-01

    Space exploitation is impossible without large space structures. We need to make sufficient large volume of pressurized protecting frames for crew, passengers, space processing equipment, & etc. We have to be unlimited in space. Now the size and mass of space constructions are limited by possibility of a launch vehicle. It limits our future in exploitation of space by humans and in development of space industry. Large-size space construction can be made with using of the curing technology of the fibers-filled composites and a reactionable matrix applied directly in free space. For curing the fabric impregnated with a liquid matrix (prepreg) is prepared in terrestrial conditions and shipped in a container to orbit. In due time the prepreg is unfolded by inflating. After polymerization reaction, the durable construction can be fitted out with air, apparatus and life support systems. Our experimental studies of the curing processes in the simulated free space environment showed that the curing of composite in free space is possible. The large-size space construction can be developed. A project of space station, Moon base, Mars base, mining station, interplanet space ship, telecommunication station, space observatory, space factory, antenna dish, radiation shield, solar sail is proposed and overviewed. The study was supported by Humboldt Foundation, ESA (contract 17083/03/NL/SFe), NASA program of the stratospheric balloons and RFBR grants (05-08-18277, 12-08-00970 and 14-08-96011).

  19. Simulation of the RCS Range Resolution of Extremely Large Target

    Institute of Scientific and Technical Information of China (English)

    WANG Sheng; XIONG Qian; JIANG Ai-ping; XIA Ying-qing; XU Peng-gen

    2005-01-01

    The high frequency hybrid technique based on an iterative Physical Optics (PO) and the method of equivalent current (MEC) approach is developed for predicting range resolution of the Radar Cross Section (RCS) in the spatial domain. We introduce the hybrid high frequency method to simulate range resolution of the extremely large target in the near zone. This paper applies this method to simulate the range resolution of the two 1 m× 1 m plates and the ship.The study improves the speed of simulating the range resolution of the extremely large target and is prepared for the application of the extrapolation and interpolation in the spatial domain.

  20. Report from the 4th Workshop on Extremely Large Databases

    Directory of Open Access Journals (Sweden)

    Jacek Becla

    2011-02-01

    Full Text Available Academic and industrial users are increasingly facing the challenge of petabytes of data, but managing and analyzing such large data sets still remains a daunting task. The 4th Extremely Large Databases workshop was organized to examine the needs of communities under-represented at the past workshops facing these issues. Approaches to big data statistical analytics as well as emerging opportunities related to emerging hardware technologies were also debated. Writable extreme scale databases and the science benchmark were discussed. This paper is the final report of the discussions and activities at this workshop.

  1. A BRIGHTEST CLUSTER GALAXY WITH AN EXTREMELY LARGE FLAT CORE

    Energy Technology Data Exchange (ETDEWEB)

    Postman, Marc; Coe, Dan; Koekemoer, Anton; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Lauer, Tod R. [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); Donahue, Megan [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Graves, Genevieve [Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Moustakas, John [Center for Astrophysics and Space Sciences, University of California, La Jolla, CA 92093 (United States); Ford, Holland C.; Lemze, Doron; Medezinski, Elinor [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Grillo, Claudio [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Mariesvej 30, DK-2100 Copenhagen (Denmark); Zitrin, Adi [University of Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country UPV/EHU, Bizkaia, E-48940 Leioa (Spain); Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Ascaso, Begona [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, E-18008 Granada (Spain); Kelson, Daniel [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2012-09-10

    Hubble Space Telescope images of the galaxy cluster A2261, obtained as part of the Cluster Lensing And Supernova survey with Hubble, show that the brightest galaxy in the cluster, A2261-BCG, has the largest core yet detected in any galaxy. The cusp radius of A2261-BCG is 3.2 kpc, twice as big as the next largest core known, and {approx}3 Multiplication-Sign bigger than those typically seen in the most luminous brightest cluster galaxies. The morphology of the core in A2261-BCG is also unusual, having a completely flat interior surface brightness profile, rather than the typical shallow cusp rising into the center. This implies that the galaxy has a core with constant or even centrally decreasing stellar density. Interpretation of the core as an end product of the 'scouring' action of a binary supermassive black hole implies a total black hole mass {approx}10{sup 10} M{sub Sun} from the extrapolation of most relationships between core structure and black hole mass. The core falls 1{sigma} above the cusp radius versus galaxy luminosity relation. Its large size in real terms, and the extremely large black hole mass required to generate it, raises the possibility that the core has been enlarged by additional processes, such as the ejection of the black holes that originally generated the core. The flat central stellar density profile is consistent with this hypothesis. The core is also displaced by 0.7 kpc from the center of the surrounding envelope, consistent with a local dynamical perturbation of the core.

  2. In vitro leakage associated with three root-filling techniques in large and extremely large root canals.

    Science.gov (United States)

    Mente, Johannes; Werner, Sabine; Koch, Martin Jean; Henschel, Volkmar; Legner, Milos; Staehle, Hans Joerg; Friedman, Shimon

    2007-03-01

    This study assessed the apical leakage of ultrasonically condensed root fillings in extremely large canals, compared to cold lateral condensation and thermoplastic compaction. Ninety single-rooted teeth were used. In 45 teeth canals were enlarged to size 70 (large). The remaining 45 canals were enlarged to size 140 (extremely large). Each set of teeth was subdivided into three root-filling groups (n = 15): (1) cold lateral condensation (LC); (2) thermoplastic compaction (TC); and (3) ultrasonic lateral condensation (UC). Teeth in all six subgroups were subjected to drawing ink penetration, cleared, and evaluated for linear apical dye leakage. Significantly deeper dye penetration (p < 0.04, Wilcoxon rank-sum test) was observed for LC than for UC. TC did not differ significantly from LC and UC. Dye penetration was significantly deeper (p < 0.0001) in canals enlarged to size 140 than to size 70, independent of root-filling method. Apical leakage associated with ultrasonically condensed root fillings was less than that with cold lateral condensation. It was consistently greater in extremely large canals than that in large ones.

  3. Large size metallic glass gratings by embossing

    Science.gov (United States)

    Ma, J.; Yi, J.; Zhao, D. Q.; Pan, M. X.; Wang, W. H.

    2012-09-01

    Bulk metallic glasses have excellent thermoforming ability in their wide supercooled liquid region. We show that large-size metallic glass grating (˜8 × 8 mm2) with fine periodicity and ultra smooth surface feature can be readily fabricated by hot embossing. The method for fabrication of gratings is proved to be much cheaper, and requires low pressure and short time (less than 30 s). The metallic glass gratings exhibit comparable optical properties such as rainbow-like spectrum when shone by fluorescent lamp light.

  4. The Cherenkov Telescope Array Large Size Telescope

    CERN Document Server

    Ambrosi, G; Baba, H; Bamba, A; Barceló, M; de Almeida, U Barres; Barrio, J A; Bigas, O Blanch; Boix, J; Brunetti, L; Carmona, E; Chabanne, E; Chikawa, M; Colin, P; Conteras, J L; Cortina, J; Dazzi, F; Deangelis, A; Deleglise, G; Delgado, C; Díaz, C; Dubois, F; Fiasson, A; Fink, D; Fouque, N; Freixas, L; Fruck, C; Gadola, A; García, R; Gascon, D; Geffroy, N; Giglietto, N; Giordano, F; Grañena, F; Gunji, S; Hagiwara, R; Hamer, N; Hanabata, Y; Hassan, T; Hatanaka, K; Haubold, T; Hayashida, M; Hermel, R; Herranz, D; Hirotani, K; Inoue, S; Inoue, Y; Ioka, K; Jablonski, C; Kagaya, M; Katagiri, H; Kishimoto, T; Kodani, K; Kohri, K; Konno, Y; Koyama, S; Kubo, H; Kushida, J; Lamanna, G; Flour, T Le; López-Moya, M; López, R; Lorenz, E; Majumdar, P; Manalaysay, A; Mariotti, M; Martínez, G; Martínez, M; Mazin, D; Miranda, J M; Mirzoyan, R; Monteiro, I; Moralejo, A; Murase, K; Nagataki, S; Nakajima, D; Nakamori, T; Nishijima, K; Noda, K; Nozato, A; Ohira, Y; Ohishi, M; Ohoka, H; Okumura, A; Orito, R; Panazol, J L; Paneque, D; Paoletti, R; Paredes, J M; Pauletta, G; Podkladkin, S; Prast, J; Rando, R; Reimann, O; Ribó, M; Rosier-Lees, S; Saito, K; Saito, T; Saito, Y; Sakaki, N; Sakonaka, R; Sanuy, A; Sasaki, H; Sawada, M; Scalzotto, V; Schultz, S; Schweizer, T; Shibata, T; Shu, S; Sieiro, J; Stamatescu, V; Steiner, S; Straumann, U; Sugawara, R; Tajima, H; Takami, H; Tanaka, S; Tanaka, M; Tejedor, L A; Terada, Y; Teshima, M; Totani, T; Ueno, H; Umehara, K; Vollhardt, A; Wagner, R; Wetteskind, H; Yamamoto, T; Yamazaki, R; Yoshida, A; Yoshida, T; Yoshikoshi, T

    2013-01-01

    The two arrays of the Very High Energy gamma-ray observatory Cherenkov Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA to achieve a low-energy threshold of 20 GeV, which is critical for important studies in astrophysics, astroparticle physics and cosmology. This work presents the key specifications and performance of the current LST design in the light of the CTA scientific objectives.

  5. Design concepts for the California Extremely Large Telescope (CELT)

    Science.gov (United States)

    Nelson, Jerry E.

    2000-08-01

    The California Extremely Large Telescope is a study currently underway by the University of California and the California Institute of Technology, to assess the feasibility of building a 30-m ground based telescope that will push the frontiers to observational astronomy. The telescope will be fully steerable, with a large field of view, and be able to work in both a seeing-limited arena and as a diffraction-limited telescope, with adaptive optics.

  6. Imaging extrasolar planets with the European Extremely Large Telescope

    Directory of Open Access Journals (Sweden)

    Jolissaint L.

    2011-07-01

    Full Text Available The European Extremely Large Telescope (E-ELT is the most ambitious of the ELTs being planned. With a diameter of 42 m and being fully adaptive from the start, the E-ELT will be more than one hundred times more sensitive than the present-day largest optical telescopes. Discovering and characterising planets around other stars will be one of the most important aspects of the E-ELT science programme. We model an extreme adaptive optics instrument on the E-ELT. The resulting contrast curves translate to the detectability of exoplanets.

  7. Report from the 3rd Workshop on Extremely Large Databases

    Directory of Open Access Journals (Sweden)

    Jacek Becla

    2010-02-01

    Full Text Available Academic and industrial users are increasingly facing the challenge of petabytes of data, but managing and analyzing such large data sets still remains a daunting task. Both the database and the map/reduce communities worldwide are working on addressing these issues. The 3rdExtremely Large Databases workshop was organized to examine the needs of scientific communities beginning to face these issues, to reach out to European communities working on extremely large scale data challenges, and to brainstorm possible solutions. The science benchmark that emerged from the 2nd workshop in this series was also debated. This paper is the final report of the discussions and activities at this workshop.

  8. Large Chip Production Mechanism under the Extreme Load Cutting Conditions

    Institute of Scientific and Technical Information of China (English)

    LIU Xianli; HE Genghuang; YAN Fugang; CHENG Yaonan; LIU Li

    2015-01-01

    There has existed a great deal of theory researches in term of chip production and chip breaking characteristics under conventional cutting and high speed cutting conditions, however, there isn’t sufficient research on chip formation mechanism as well as its influence on cutting state regarding large workpieces under extreme load cutting. This paper presents a model of large saw-tooth chip through applying finite element simulation method, which gives a profound analysis about the characteristics of the extreme load cutting as well as morphology and removal of the large chip. In the meantime, a calculation formula that gives a quantitative description of the saw-tooth level regarding the large chip is established on the basis of cutting experiments on high temperature and high strength steel 2.25Cr-1Mo-0.25V. The cutting experiments are carried out by using the scanning electron microscope and super depth of field electron microscope to measure and calculate the large chip produced under different cutting parameters, which can verify the validity of the established model. The calculating results show that the large saw-toothed chip is produced under the squeezing action between workpiece and cutting tools. In the meanwhile, the chip develops a hardened layer where contacts the cutting tool and the saw-tooth of the chip tend to form in transverse direction. This research creates the theoretical model for large chip and performs the cutting experiments under the extreme load cutting condition, as well as analyzes the production mechanism of the large chip in the macro and micro conditions. Therefore, the proposed research could provide theoretical guidance and technical support in improving productivity and cutting technology research.

  9. Properties of Zerodur mirror blanks for extremely large telescopes

    Science.gov (United States)

    Döhring, Thorsten; Hartmann, Peter; Jedamzik, Ralf; Thomas, Armin; Lentes, Frank-Thomas

    2006-02-01

    SCHOTT produces the zero expansion glass ceramics material ZERODUR since 35 years. More than 250 ZERODUR mirror blanks were already delivered for the large segmented mirror telescopes KECK I, KECK II, HET, GTC, and LAMOST. Now several extremely large telescope (ELT) projects are in discussion, which are designed with even larger primary mirrors (TMT, OWL, EURO50, JELT, CFGT, GMT). These telescopes can be achieved also only by segmentation of the primary mirror. Based on the results of the recent production of segment blanks for the GTC project the general requirements of mirror blanks for future extremely large telescope projects have been evaluated. The specification regarding the material quality and blank geometry is discussed in detail. As the planned mass production of mirror blanks for ELT's will last for several years, economic factors are getting even more important for the success of the projects. SCHOTT is a global enterprise with a solid economical basis and therefore an ideal partner for the mirror blank delivery of extremely large telescopes.

  10. Report from the 2nd Workshop on Extremely Large Databases

    Directory of Open Access Journals (Sweden)

    Jacek Becla

    2009-03-01

    Full Text Available The complexity and sophistication of large scale analytics in science and industry have advanced dramatically in recent years. Analysts are struggling to use complex techniques such as time series analysis and classification algorithms because their familiar, powerful tools are not scalable and cannot effectively use scalable database systems. The 2nd Extremely Large Databases (XLDB workshop was organized to understand these issues, examine their implications, and brainstorm possible solutions. The design of a new open source science database, SciDB that emerged from the first workshop in this series was also debated. This paper is the final report of the discussions and activities at this workshop.

  11. Challenges in optics for Extremely Large Telescope instrumentation

    CERN Document Server

    Span`o, P; Norrie, C J; Cunningham, C R; Strassmeier, K G; Bianco, A; Blanche, P A; Bougoin, M; Ghigo, M; Hartmann, P; Zago, L; Atad-Ettedgui, E; Delabre, B; Dekker, H; Melozzi, M; Snyders, B; Takke, R; Walker, D D

    2006-01-01

    We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60m aperture telescopes. After all, the success of ELTs will heavily rely on its instrumentation and this, in turn, will depend on the ability to produce large and ultra-precise optical components like light-weight mirrors, aspheric lenses, segmented filters, and large gratings. New materials and manufacturing processes are currently under study, both at research institutes and in industry. In the present paper, we report on its progress with particular emphasize on volume-phase-holographic gratings, photochromic materials, sintered silicon-carbide mirrors, ion-beam figuring, ultra-precision surfaces, and free-form optics. All are promising technologies opening new degrees of freedom to optical designers. New optronic-mechanical systems will enable efficient use of the very large focal planes. We also provide...

  12. Optical Design for Extremely Large Telescope Adaptive Optics Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, B J

    2003-11-26

    Designing an adaptive optics (AO) system for extremely large telescopes (ELT's) will present new optical engineering challenges. Several of these challenges are addressed in this work, including first-order design of multi-conjugate adaptive optics (MCAO) systems, pyramid wavefront sensors (PWFS's), and laser guide star (LGS) spot elongation. MCAO systems need to be designed in consideration of various constraints, including deformable mirror size and correction height. The y,{bar y} method of first-order optical design is a graphical technique that uses a plot with marginal and chief ray heights as coordinates; the optical system is represented as a segmented line. This method is shown to be a powerful tool in designing MCAO systems. From these analyses, important conclusions about configurations are derived. PWFS's, which offer an alternative to Shack-Hartmann (SH) wavefront sensors (WFS's), are envisioned as the workhorse of layer-oriented adaptive optics. Current approaches use a 4-faceted glass pyramid to create a WFS analogous to a quad-cell SH WFS. PWFS's and SH WFS's are compared and some newly-considered similarities and PWFS advantages are presented. Techniques to extend PWFS's are offered: First, PWFS's can be extended to more pixels in the image by tiling pyramids contiguously. Second, pyramids, which are difficult to manufacture, can be replaced by less expensive lenslet arrays. An approach is outlined to convert existing SH WFS's to PWFS's for easy evaluation of PWFS's. Also, a demonstration of PWFS's in sensing varying amounts of an aberration is presented. For ELT's, the finite altitude and finite thickness of LGS's means that the LGS will appear elongated from the viewpoint of subapertures not directly under the telescope. Two techniques for dealing with LGS spot elongation in SH WFS's are presented. One method assumes that the laser will be pulsed and uses a segmented micro

  13. Undersampling power-law size distributions: effect on the assessment of extreme natural hazards

    Science.gov (United States)

    Geist, Eric L.; Parsons, Thomas E.

    2014-01-01

    The effect of undersampling on estimating the size of extreme natural hazards from historical data is examined. Tests using synthetic catalogs indicate that the tail of an empirical size distribution sampled from a pure Pareto probability distribution can range from having one-to-several unusually large events to appearing depleted, relative to the parent distribution. Both of these effects are artifacts caused by limited catalog length. It is more difficult to diagnose the artificially depleted empirical distributions, since one expects that a pure Pareto distribution is physically limited in some way. Using maximum likelihood methods and the method of moments, we estimate the power-law exponent and the corner size parameter of tapered Pareto distributions for several natural hazard examples: tsunamis, floods, and earthquakes. Each of these examples has varying catalog lengths and measurement thresholds, relative to the largest event sizes. In many cases where there are only several orders of magnitude between the measurement threshold and the largest events, joint two-parameter estimation techniques are necessary to account for estimation dependence between the power-law scaling exponent and the corner size parameter. Results indicate that whereas the corner size parameter of a tapered Pareto distribution can be estimated, its upper confidence bound cannot be determined and the estimate itself is often unstable with time. Correspondingly, one cannot statistically reject a pure Pareto null hypothesis using natural hazard catalog data. Although physical limits to the hazard source size and by attenuation mechanisms from source to site constrain the maximum hazard size, historical data alone often cannot reliably determine the corner size parameter. Probabilistic assessments incorporating theoretical constraints on source size and propagation effects are preferred over deterministic assessments of extreme natural hazards based on historic data.

  14. Large Scale Meteorological Pattern of Extreme Rainfall in Indonesia

    Science.gov (United States)

    Kuswanto, Heri; Grotjahn, Richard; Rachmi, Arinda; Suhermi, Novri; Oktania, Erma; Wijaya, Yosep

    2014-05-01

    Extreme Weather Events (EWEs) cause negative impacts socially, economically, and environmentally. Considering these facts, forecasting EWEs is crucial work. Indonesia has been identified as being among the countries most vulnerable to the risk of natural disasters, such as floods, heat waves, and droughts. Current forecasting of extreme events in Indonesia is carried out by interpreting synoptic maps for several fields without taking into account the link between the observed events in the 'target' area with remote conditions. This situation may cause misidentification of the event leading to an inaccurate prediction. Grotjahn and Faure (2008) compute composite maps from extreme events (including heat waves and intense rainfall) to help forecasters identify such events in model output. The composite maps show large scale meteorological patterns (LSMP) that occurred during historical EWEs. Some vital information about the EWEs can be acquired from studying such maps, in addition to providing forecaster guidance. Such maps have robust mid-latitude meteorological patterns (for Sacramento and California Central Valley, USA EWEs). We study the performance of the composite approach for tropical weather condition such as Indonesia. Initially, the composite maps are developed to identify and forecast the extreme weather events in Indramayu district- West Java, the main producer of rice in Indonesia and contributes to about 60% of the national total rice production. Studying extreme weather events happening in Indramayu is important since EWEs there affect national agricultural and fisheries activities. During a recent EWE more than a thousand houses in Indramayu suffered from serious flooding with each home more than one meter underwater. The flood also destroyed a thousand hectares of rice plantings in 5 regencies. Identifying the dates of extreme events is one of the most important steps and has to be carried out carefully. An approach has been applied to identify the

  15. Report from the 5th Workshop on Extremely Large Databases

    Directory of Open Access Journals (Sweden)

    Jacek Becla

    2012-03-01

    Full Text Available The 5th XLDB workshop brought together scientific and industrial users, developers, and researchers of extremely large data and focused on emerging challenges in the healthcare and genomics communities, spreadsheet-based large scale analysis, and challenges in applying statistics to large scale analysis, including machine learning. Major problems discussed were the lack of scalable applications, the lack of expertise in developing solutions, the lack of respect for or attention to big data problems, data volume growth exceeding Moore's Law, poorly scaling algorithms, and poor data quality and integration. More communication between users, developers, and researchers is sorely needed. A variety of future work to help all three groups was discussed, ranging from collecting challenge problems to connecting with particular industrial or academic sectors.

  16. Biological Conservation of Giant Limpets: The Implications of Large Size.

    Science.gov (United States)

    Espinosa, F; Rivera-Ingraham, G A

    Patellogastropods, also known as true limpets, are distributed throughout the world and constitute key species in coastal ecosystems. Some limpet species achieve remarkable sizes, which in the most extreme cases can surpass 35cm in shell length. In this review, we focus on giant limpets, which are defined as those with a maximum shell size surpassing 10cm. According to the scientific literature, there are a total of 14 species across five genera that reach these larger sizes. Four of these species are threatened or in danger of extinction. Inhabiting the intertidal zones, limpets are frequently affected by anthropogenic impacts, namely collection by humans, pollution and habitat fragmentation. In the case of larger species, their conspicuous size has made them especially prone to human collection since prehistoric times. Size is not phylogeny-dependent among giant limpets, but is instead related to behavioural traits instead. Larger-sized species tend to be nonmigratory and territorial compared to those that are smaller. Collection by humans has been cited as the main cause behind the decline and/or extinction of giant limpet populations. Their conspicuously large size makes them the preferred target of human collection. Because they are protandric species, selectively eliminating larger specimens of a given population seriously compromises their viability and has led to local extinction events in some cases. Additionally, sustained collection over time may lead to microevolutionary responses that result in genetic changes. The growing presence of artificial structures in coastal ecosystems may cause population fragmentation and isolation, limiting the genetic flow and dispersion capacity of many limpet species. However, when they are necessitated, artificial structures could be managed to establish marine artificial microreserves and contribute to the conservation of giant limpet species that naturally settle on them. © 2017 Elsevier Ltd. All rights reserved.

  17. Progress on the California Extremely Large Telescope (CELT)

    Science.gov (United States)

    Nelson, Jerry E.

    2003-01-01

    The California Extremely Large Telescope (CELT) is a joint project of the University of California and the California Institute of Technology to build and operate a 30-meter diameter telescope for research in astronomy at visible and infrared wavelengths. The current optical design calls for a primary, secondary, and tertiary mirror with Ritchey-Chretién foci at two Nasmyth platforms. The primary mirror is a mosaic of 1080 actively stabilized hexagonal segments. This paper summarizes the recent progress on the conceptual design of this telescope.

  18. Report from the 6th Workshop on Extremely Large Databases

    Directory of Open Access Journals (Sweden)

    Daniel Liwei Wang

    2013-05-01

    Full Text Available Petascale data management and analysis remain one of the main unresolved challenges in today's computing. The 6th Extremely Large Databases workshop was convened alongside the XLDB conference to discuss the challenges in the health care, biology, and natural resources communities. The role of cloud computing, the dominance of file-based solutions in science applications, in-situ and predictive analysis, and commercial software use in academic environments were discussed in depth as well. This paper summarizes the discussions of this workshop.

  19. Extremely Large Telescope Project Selected in ESFRI Roadmap

    Science.gov (United States)

    2006-10-01

    In its first Roadmap, the European Strategy Forum on Research Infrastructures (ESFRI) choose the European Extremely Large Telescope (ELT), for which ESO is presently developing a Reference Design, as one of the large scale projects to be conducted in astronomy, and the only one in optical astronomy. The aim of the ELT project is to build before the end of the next decade an optical/near-infrared telescope with a diameter in the 30-60m range. ESO PR Photo 40/06 The ESFRI Roadmap states: "Extremely Large Telescopes are seen world-wide as one of the highest priorities in ground-based astronomy. They will vastly advance astrophysical knowledge allowing detailed studies of inter alia planets around other stars, the first objects in the Universe, super-massive Black Holes, and the nature and distribution of the Dark Matter and Dark Energy which dominate the Universe. The European Extremely Large Telescope project will maintain and reinforce Europe's position at the forefront of astrophysical research." Said Catherine Cesarsky, Director General of ESO: "In 2004, the ESO Council mandated ESO to play a leading role in the development of an ELT for Europe's astronomers. To that end, ESO has undertaken conceptual studies for ELTs and is currently also leading a consortium of European institutes engaged in studying enabling technologies for such a telescope. The inclusion of the ELT in the ESFRI roadmap, together with the comprehensive preparatory work already done, paves the way for the next phase of this exciting project, the design phase." ESO is currently working, in close collaboration with the European astronomical community and the industry, on a baseline design for an Extremely Large Telescope. The plan is a telescope with a primary mirror between 30 and 60 metres in diameter and a financial envelope of about 750 m Euros. It aims at more than a factor ten improvement in overall performance compared to the current leader in ground based astronomy: the ESO Very Large

  20. Extreme value statistics and thermodynamics of earthquakes: large earthquakes

    Directory of Open Access Journals (Sweden)

    B. H. Lavenda

    2000-06-01

    Full Text Available A compound Poisson process is used to derive a new shape parameter which can be used to discriminate between large earthquakes and aftershock sequences. Sample exceedance distributions of large earthquakes are fitted to the Pareto tail and the actual distribution of the maximum to the Fréchet distribution, while the sample distribution of aftershocks are fitted to a Beta distribution and the distribution of the minimum to the Weibull distribution for the smallest value. The transition between initial sample distributions and asymptotic extreme value distributions shows that self-similar power laws are transformed into nonscaling exponential distributions so that neither self-similarity nor the Gutenberg-Richter law can be considered universal. The energy-magnitude transformation converts the Fréchet distribution into the Gumbel distribution, originally proposed by Epstein and Lomnitz, and not the Gompertz distribution as in the Lomnitz-Adler and Lomnitz generalization of the Gutenberg-Richter law. Numerical comparison is made with the Lomnitz-Adler and Lomnitz analysis using the same Catalogue of Chinese Earthquakes. An analogy is drawn between large earthquakes and high energy particle physics. A generalized equation of state is used to transform the Gamma density into the order-statistic Fréchet distribution. Earthquaketemperature and volume are determined as functions of the energy. Large insurance claims based on the Pareto distribution, which does not have a right endpoint, show why there cannot be a maximum earthquake energy.

  1. Extreme value statistics and thermodynamics of earthquakes. Large earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Lavenda, B. [Camerino Univ., Camerino, MC (Italy); Cipollone, E. [ENEA, Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy). National Centre for Research on Thermodynamics

    2000-06-01

    A compound Poisson process is used to derive a new shape parameter which can be used to discriminate between large earthquakes and aftershocks sequences. Sample exceedance distributions of large earthquakes are fitted to the Pareto tail and the actual distribution of the maximum to the Frechet distribution, while the sample distribution of aftershocks are fitted to a Beta distribution and the distribution of the minimum to the Weibull distribution for the smallest value. The transition between initial sample distributions and asymptotic extreme value distributions show that self-similar power laws are transformed into non scaling exponential distributions so that neither self-similarity nor the Gutenberg-Richter law can be considered universal. The energy-magnitude transformation converts the Frechet distribution into the Gumbel distribution, originally proposed by Epstein and Lomnitz, and not the Gompertz distribution as in the Lomnitz-Adler and Lomnitz generalization of the Gutenberg-Richter law. Numerical comparison is made with the Lomnitz-Adler and Lomnitz analysis using the same catalogue of Chinese earthquakes. An analogy is drawn between large earthquakes and high energy particle physics. A generalized equation of state is used to transform the Gamma density into the order-statistic Frechet distribution. Earthquake temperature and volume are determined as functions of the energy. Large insurance claims based on the Pareto distribution, which does not have a right endpoint, show why there cannot be a maximum earthquake energy.

  2. Challenges in optics for Extremely Large Telescope instrumentation

    Science.gov (United States)

    Spanò, P.; Zerbi, F. M.; Norrie, C. J.; Cunningham, C. R.; Strassmeier, K. G.; Bianco, A.; Blanche, P. A.; Bougoin, M.; Ghigo, M.; Hartmann, P.; Zago, L.; Atad-Ettedgui, E.; Delabre, B.; Dekker, H.; Melozzi, M.; Snÿders, B.; Takke, R.

    2006-08-01

    We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60 m aperture telescopes. After all, the success of ELTs will heavily rely on its instrumentation and this, in turn, will depend on the ability to produce large and ultra-precise optical components like light-weight mirrors, aspheric lenses, segmented filters, and large gratings. New materials and manufacturing processes are currently under study, both at research institutes and in industry. In the present paper, we report on its progress with particular emphasize on volume-phase-holographic gratings, photochromic materials, sintered silicon-carbide mirrors, ion-beam figuring, ultra-precision surfaces, and free-form optics. All are promising technologies opening new degrees of freedom to optical designers. New optronic-mechanical systems will enable efficient use of the very large focal planes. We also provide exploratory descriptions of ``old'' and ``new'' optical technologies together with suggestions to instrument designers to overcome some of the challenges placed by ELT instrumentation.

  3. On bootstrap sample size in extreme value theory

    NARCIS (Netherlands)

    J.L. Geluk (Jaap); L.F.M. de Haan (Laurens)

    2002-01-01

    textabstractIt has been known for a long time that for bootstrapping the probability distribution of the maximum of a sample consistently, the bootstrap sample size needs to be of smaller order than the original sample size. See Jun Shao and Dongsheng Tu (1995), Ex. 3.9,p. 123. We show that the same

  4. Control of the California Extremely Large Telescope primary mirror

    Science.gov (United States)

    MacMartin, Douglas G.; Chanan, Gary A.

    2003-01-01

    The current design concept for the California Extremely Large Telescope (CELT) includes 1080 segments in the primary mirror, with the out-of-plane degrees of freedom actively controlled. We construct the control matrix for this active control system, and describe its singular modes and sensor noise propagation. Data from the Keck telescopes are used to generate realistic estimates of the control system contributions to the CELT wavefront error and wavefront gradient error. Based on these estimates, control system noise will not significantly degrade either seeing-limited or diffraction-limited observations. The use of supplemental wavefront information for real-time control is therefore not necessary. We also comment briefly on control system bandwidth requirements and limitations.

  5. Origin of the extremely large magnetoresistance in the semimetal YSb

    Science.gov (United States)

    Xu, J.; Ghimire, N. J.; Jiang, J. S.; Xiao, Z. L.; Botana, A. S.; Wang, Y. L.; Hao, Y.; Pearson, J. E.; Kwok, W. K.

    2017-08-01

    Electron-hole (e -h ) compensation is a hallmark of multiband semimetals with extremely large magnetoresistance (XMR) and has been considered to be the basis for XMR. Recent spectroscopic experiments, however, reveal that YSb with nonsaturating magnetoresistance is uncompensated, questioning the e -h compensation scenario for XMR. Here we demonstrate with magnetoresistivity and angle-dependent Shubnikov-de Haas (SdH) quantum oscillation measurements that YSb does have nearly perfect e -h compensation, with a density ratio of ˜0.95 for electrons and holes. The density and mobility anisotropy of the charge carriers revealed in the SdH experiments allow us to quantitatively describe the magnetoresistance with an anisotropic multiband model that includes contributions from all Fermi pockets. We elucidate the role of compensated multibands in the occurrence of XMR by demonstrating the evolution of calculated magnetoresistances for a single band and for various combinations of electron and hole Fermi pockets.

  6. European Extremely Large Telescope Site Characterization I: Overview

    Science.gov (United States)

    Vernin, Jean; Muñoz-Tuñón, Casiana; Sarazin, Marc; Vazquez Ramió, Héctor; Varela, Antonia M.; Trinquet, Hervé; Delgado, José Miguel; Jiménez Fuensalida, Jesús; Reyes, Marcos; Benhida, Abdelmajid; Benkhaldoun, Zouhair; García Lambas, Diego; Hach, Youssef; Lazrek, M.; Lombardi, Gianluca; Navarrete, Julio; Recabarren, Pablo; Renzi, Victor; Sabil, Mohammed; Vrech, Rubén

    2011-11-01

    The site for the future European Extremely Large Telescope (E-ELT) is already known to be Armazones, near Paranal (Chile). The selection was based on a variety of considerations, with an important one being the quality of the atmosphere for the astronomy planned for the ELT. We present an overview of the characterization of the atmospheric parameters of candidate sites, making use of standard procedures and instruments as carried out within the Framework Programme VI (FP6) of the European Union. We have achieved full characterization of the selected sites for the parameters considered. Further details on adaptive optics results and climatology will be the subject of two forthcoming articles. A summary of the results of the FP6 site-testing campaigns at the different sites is provided.

  7. Stellar Crowding and the Science Case for Extremely Large Telescopes

    CERN Document Server

    Olsen, K A G; Rigaut, F; Olsen, Knut A.G.; Blum, Robert D.; Rigaut, Francois

    2003-01-01

    We present a study of the effect of crowding on stellar photometry. We develop an analytical model through which we are able to predict the error in magnitude and color for a given star for any combination of telescope resolution, stellar luminosity function, background surface brightness, and distance. We test our predictions with Monte Carlo simulations of the LMC globular cluster NGC 1835, for resolutions corresponding to a seeing-limited telescope, the $HST$, and an AO-corrected 30-m (near diffraction limited) telescope. Our analytically predicted magnitude errors agree with the simulation results to within $\\sim$20%. The analytical model also predicts that errors in color are strongly affected by the correlation of crowding--induced photometric errors between bands as is seen in the simulations. Using additional Monte Carlo simulations and our analytical crowding model, we investigate the photometric accuracy which 30-m and 100-m Extremely Large Telescopes (ELTs) will be able to achieve at distances exte...

  8. Extreme Associated Functions: Optimally Linking Local Extremes to Large-scale Atmospheric Circulation Structures

    CERN Document Server

    Panja, Debabrata

    2007-01-01

    We present a new statistical method to optimally link local weather extremes to large-scale atmospheric circulation structures. The method is illustrated using July-August daily mean temperature at 2m height (T2m) time-series over the Netherlands and 500 hPa geopotential height (Z500) time-series over the Euroatlantic region of the ECMWF reanalysis dataset (ERA40). The method identifies patterns in the Z500 time-series that optimally describe, in a precise mathematical sense, the relationship with local warm extremes in the Netherlands. Two patterns are identified; the most important one corresponds to a blocking high pressure system leading to subsidence and calm, dry and sunny conditions over the Netherlands. The second one corresponds to a rare, easterly flow regime bringing warm, dry air into the region. The patterns are robust; they are also identified in shorter subsamples of the total dataset. The method is generally applicable and might prove useful in evaluating the performance of climate models in s...

  9. Cluster dynamics largely shapes protoplanetary disc sizes

    CERN Document Server

    Vincke, Kirsten

    2016-01-01

    It is still on open question to what degree the cluster environment influences the sizes of protoplanetary discs surrounding young stars. Particularly so for the short-lived clusters typical for the solar neighbourhood in which the stellar density and therefore the influence of the cluster environment changes considerably over the first 10 Myr. In previous studies often the effect of the gas on the cluster dynamics has been neglected, this is remedied here. Using the code NBody6++ we study the stellar dynamics in different developmental phases - embedded, expulsion, expansion - including the gas and quantify the effect of fly-bys on the disc size. We concentrate on massive clusters ($M_{\\text{cl}} \\geq 10^3 - 6 \\cdot 10^4 M_{\\text{Sun}}$), which are representative for clusters like the Orion Nebula Cluster (ONC) or NGC 6611. We find that not only the stellar density but also the duration of the embedded phase matters. The densest clusters react fastest to the gas expulsion and drop quickly in density, here 98...

  10. Parallel multiple instance learning for extremely large histopathology image analysis.

    Science.gov (United States)

    Xu, Yan; Li, Yeshu; Shen, Zhengyang; Wu, Ziwei; Gao, Teng; Fan, Yubo; Lai, Maode; Chang, Eric I-Chao

    2017-08-03

    Histopathology images are critical for medical diagnosis, e.g., cancer and its treatment. A standard histopathology slice can be easily scanned at a high resolution of, say, 200,000×200,000 pixels. These high resolution images can make most existing imaging processing tools infeasible or less effective when operated on a single machine with limited memory, disk space and computing power. In this paper, we propose an algorithm tackling this new emerging "big data" problem utilizing parallel computing on High-Performance-Computing (HPC) clusters. Experimental results on a large-scale data set (1318 images at a scale of 10 billion pixels each) demonstrate the efficiency and effectiveness of the proposed algorithm for low-latency real-time applications. The framework proposed an effective and efficient system for extremely large histopathology image analysis. It is based on the multiple instance learning formulation for weakly-supervised learning for image classification, segmentation and clustering. When a max-margin concept is adopted for different clusters, we obtain further improvement in clustering performance.

  11. New challenges for Adaptive Optics Extremely Large Telescopes

    CERN Document Server

    Le Louarn, M; Sarazin, M; Tokovinin, A

    2000-01-01

    The performance of an adaptive optics (AO) system on a 100m diameter ground based telescope working in the visible range of the spectrum is computed using an analytical approach. The target Strehl ratio of 60% is achieved at 0.5um with a limiting magnitude of the AO guide source near R~10, at the cost of an extremely low sky coverage. To alleviate this problem, the concept of tomographic wavefront sensing in a wider field of view using either natural guide stars (NGS) or laser guide stars (LGS) is investigated. These methods use 3 or 4 reference sources and up to 3 deformable mirrors, which increase up to 8-fold the corrected field size (up to 60\\arcsec at 0.5 um). Operation with multiple NGS is limited to the infrared (in the J band this approach yields a sky coverage of 50% with a Strehl ratio of 0.2). The option of open-loop wavefront correction in the visible using several bright NGS is discussed. The LGS approach involves the use of a faint (R ~22) NGS for low-order correction, which results in a sky cov...

  12. Single sided tomography of extremely large dense objects

    Energy Technology Data Exchange (ETDEWEB)

    Thoe, R.S.

    1993-03-24

    One can envision many circumstances where radiography could be valuable but is frustrated by the geometry of the object to be radiographed. For example, extremely large objects, the separation of rocket propellants from the skin of solid fuel rocket motor, the structural integrity of an underground tank or hull of a ship, the location of buried objects, inspection of large castings etc. The author has been investigating ways to do this type of radiography and as a result has developed a technique which can be used to obtain three dimensional radiographs using Compton scattered radiation from a monochromatic source and a high efficiency, high resolution germanium spectrometer. This paper gives specific details of the reconstruction technique and presents the results of numerous numerical simulations and compares these simulations to spectra obtained in the laboratory. In addition the author presents the results of calculations made for the development of an alternative single sided radiography technique which will permit inspection of the interior of large objects. As a benchmark the author seeks to obtain three dimensional images with a resolution of about one cubic centimeter in a concrete cube 30 centimeters on a side. Such a device must use photons of very high energy. For example 30 cm of concrete represents about 15 mean free paths for photons of 100 keV, whereas at 1 MeV the attenuation is down to about five mean free paths. At these higher energies Compton scattering becomes much more probable. Although this would appear to be advantageous for single sided imaging techniques, such techniques are hampered by two side effects. In this paper the results are given of numerous Monte Carlo calculations detailing the extent of the multiple scattering and the feasibility of a variety of imaging schemes is explored.

  13. On the white dwarf cooling sequence with extremely large telescopes

    CERN Document Server

    Bono, G; Gilmozzi, R

    2012-01-01

    We present new diagnostics of white dwarf (WD) cooling sequences and luminosity functions (LFs) in the near-infrared (NIR) bands that will exploit the sensitivity and resolution of future extremely large telescopes. The collision-induced absorption (CIA) of molecular hydrogen causes a clearly defined blue turn-off along the WD (WDBTO) cooling sequences and a bright secondary maximum in the WD LFs. These features are independent of age over a broad age range and are minimally affected by metal abundance. This means that the NIR magnitudes of the WDBTO are very promising distance indicators. The interplay between the cooling time of progressively more massive WDs and the onset of CIA causes a red turn-off along the WD (WDRTO) cooling sequences and a well defined faint peak in the WD LFs. These features are very sensitive to the cluster age, and indeed the K-band magnitude of the faint peak increases by 0.2--0.25 mag/Gyr for ages between 10 and 14 Gyr. On the other hand, the faint peak in the optical WD LF incre...

  14. Observing Planetary Nebulae with JWST and Extremely Large Telescopes

    Science.gov (United States)

    Sahai, Raghvendra

    2015-01-01

    Most stars in the Universe that leave the main sequence in a Hubble time will end their lives evolving through the Planetary Nebula (PN) evolutionary phase. The heavy mass loss which occurs during the preceding AGB phase is important across astrophysics, dramatically changing the course of stellar evolution, dominantly contributing to the dust content of the interstellar medium, and influencing its chemical composition. The evolution from the AGB phase to the PN phases remains poorly understood, especially the dramatic transformation that occurs in the morphology of the mass-ejecta as AGB stars and their round circumstellar envelopes evolve into mostly PNe, the majority of which deviate strongly from spherical symmetry. In addition, although the PN [OIII] luminosity function (PNLF) has been used as a standard candle (on par with distance indicators such as Cepheids), we do not understand why it works. It has been argued that the resolution of these issues may be linked to binarity and associated processes such as mass transfer and common envelope evolution.Thus, understanding the formation and evolution of PNe is of wide astrophysical importance. PNe have long been known to emit across a very large span of wavelengths, from the radio to X-rays. Extensive use of space-based observatories at X-ray (Chandra/ XMM-Newton), optical (HST) and far-infrared (Spitzer, Herschel) wavelengths in recent years has produced significant new advances in our knowledge of these objects. Given the expected advent of the James Webb Space Telescope in the near future, and ground-based Extremely Large Telescope(s) somewhat later, this talk will focus on future high-angular-resolution, high-sensitivity observations at near and mid-IR wavelengths with these facilities that can help in addressing the major unsolved problems in the study of PNe.

  15. Extreme size and sequence variation in the ITS rDNA of Bremia lactucae.

    Science.gov (United States)

    Choi, Young-Joon; Hong, Seung-Boem; Shin, Hyeon-Dong

    2007-02-01

    Bremia lactucae Regel (Chromista, Peronosporaceae) is an economically destructive pathogen, which causes downy mildew disease on lettuce (Lactuca sativa L.) worldwide. The ribosomal internal transcribed spacer (ITS) of Bremia lactucae isolates was analyzed for the first time. The ITS region of lettuce downy mildew was observed to have a size of 2458 bp; thereby, having one of the longest ITS sizes recorded to date. The majority of the extremely large sized ITS2 length of 2086 was attributed to the additional presences of nine repetitive elements with lengths of 179-194 bp, which between them shared the low homology of 48-69%. Comparison of the ITS2 sequences with the B. lactucae isolates from other host plants showed that isolates present on Lactuca sativa were distinct from those on L. indica var. laciniata, as well as Hemistepta and Youngia. We suggest the high degree of sequence heterogeneity exhibited in the ITS2 region of B. lactucae may warrant the specific detection and diagnosis of this destructive pathogen or its division into several distinct species.

  16. A new concept for large deformable mirrors for extremely large telescopes

    Science.gov (United States)

    Andersen, Torben; Owner-Petersen, Mette; Ardeberg, Arne; Korhonen, Tapio

    2006-06-01

    For extremely large telescopes, there is strong need for thin deformable mirrors in the 3-4 m class. So far, feasibility of such mirrors has not been demonstrated. Extrapolation from existing techniques suggests that the mirrors could be highly expensive. We give a progress report on a study of an approach for construction of large deformable mirrors with a moderate cost. We have developed low-cost actuators and deflection sensors that can absorb mounting tolerances in the millimeter range, and we have tested prototypes in the laboratory. Studies of control laws for mirrors with thousands of sensors and actuators are in good progress and simulations have been carried out. Manufacturing of thin, glass mirror blanks is being studied and first prototypes have been produced by a slumping technique. Development of polishing procedures for thin mirrors is in progress.

  17. Direct Imaging of Exoplanets, from very large to extremely large telescopes

    Science.gov (United States)

    Kasper, M.

    2015-10-01

    Presently, dedicated instruments at 8-m class telescopes (SPHERE for the VLT, GPI for Gemini) are about to discover and explore self-luminous giant planets by direct imaging and spectroscopy. In a decade, the next generation of 30m-40m ground-based Extremely Large Telescopes (ELTs) have the potential to dramatically enlarge the discovery space towards older giant planets seen in the reflected light and ultimately even a small number of rocky planets. In order to fulfill the demanding contrast requirements of a part in a million to a part in a billion at separations of one tenth of an arcsecond, the seeing limited PSF contrast must gradually be improved by eXtreme Adaptive optics (XAO), non-common path aberration compensation, coronagraphy, and science image post-processing. None of these steps alone is sufficient to leap the enormous contrast. High-contrast imaging (HCI) from the ground encompasses all those disciplines which are to be considered in a system approach. The presentation will introduce the principle of HCI and present the current implementation in the SPHERE, ESO's imager for giant exoplanets at the VLT. It will then discuss requirements and necessary R&D to reach the ultimate goal, observing terrestrial Exoplanets with the next generation of instruments for the ELTs.

  18. Small body size and extreme cortical bone remodeling indicate phyletic dwarfism in Magyarosaurus dacus (Sauropoda: Titanosauria).

    Science.gov (United States)

    Stein, Koen; Csiki, Zoltan; Rogers, Kristina Curry; Weishampel, David B; Redelstorff, Ragna; Carballido, Jose L; Sander, P Martin

    2010-05-18

    Sauropods were the largest terrestrial tetrapods (>10(5) kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size.

  19. California Extremely Large Telescope : conceptual design for a thirty-meter telescope

    Science.gov (United States)

    Following great success in the creation of the Keck Observatory, scientists at the California Institute of Technology and the University of California have begun to explore the scientific and technical prospects for a much larger telescope. The Keck telescopes will remain the largest telescopes in the world for a number of years, with many decades of forefront research ahead after that. Though these telescopes have produced dramatic discoveries, it is already clear that even larger telescopes must be built if we are to address some of the most profound questions about our universe. The time required to build a larger telescope is approximately ten years, and the California community is presently well-positioned to begin its design and construction. The same scientists who conceived, led the design, and guided the construction of the Keck Observatory have been intensely engaged in a study of the prospects for an extremely large telescope. Building on our experience with the Keck Observatory, we have concluded that the large telescope is feasible and is within the bounds set by present-day technology. Our reference telescope has a diameter of 30 meters, the largest size we believe can be built with acceptable risk. The project is currently designated the California Extremely Large Telescope (CELT).

  20. Fake Superpotential for Large and Small Extremal Black Holes

    CERN Document Server

    Andrianopoli, L; Ferrara, S; Trigiante, M

    2010-01-01

    We consider the fist order, gradient-flow, description of the scalar fields coupled to spherically symmetric, asymptotically flat black holes in extended supergravities. Using the identification of the fake superpotential with Hamilton's characteristic function we clarify some of its general properties, showing in particular (besides reviewing the issue of its duality invariance) that W has the properties of a Liapunov's function, which implies that its extrema (associated with the horizon of extremal black holes) are asymptotically stable equilibrium points of the corresponding first order dynamical system (in the sense of Liapunov). Moreover, we show that the fake superpotential W has, along the entire radial flow, the same flat directions which exist at the attractor point. This allows to study properties of the ADM mass also for small black holes where in fact W has no critical points at finite distance in moduli space. In particular the W function for small non-BPS black holes can always be computed anal...

  1. Design and preliminary test of precision segment positioning actuator for the California Extremely Large Telescope

    Science.gov (United States)

    Lorell, Kenneth R.; Aubrun, Jean-Noel; Clappier, Robert R.; Shelef, Ben; Shelef, Gad

    2003-01-01

    In order for the California Extremely Large Telescope (CELT) to achieve the required optical performance, each of its 1000 primary mirror segments must be positioned relative to adjacent segments with nanometer-level accuracy. This can be accomplished using three actuators for each segment to actively control the segment in tip, tilt, and piston. The Keck telescopes utilize a segmented primary mirror similar to CELT employing a highly successful actuator design. However, because of its size and the shear number of actuators (3000 vs. 108 for Keck), CELT will require a different design. Sensitivity to wind loads and structural vibrations, the large dynamic range, low operating power, and extremely reliable operation, all achieved at an affordable unit cost, are the most demanding design requirements. This paper examines four actuator concepts and presents a trade-off between them. The concept that best met the CELT requirements is described along with an analysis of its performance. The concept is based on techniques that achieve the required accuracy while providing a substantial amount of vibration attenuation and damping. A prototype actuator has been built to validate this concept. Preliminary tests confirm predicted behavior and future tests will establish a sound baseline for final design and production.

  2. Oscillations of a Simple Pendulum with Extremely Large Amplitudes

    Science.gov (United States)

    Butikov, Eugene I.

    2012-01-01

    Large oscillations of a simple rigid pendulum with amplitudes close to 180[degrees] are treated on the basis of a physically justified approach in which the cycle of oscillation is divided into several stages. The major part of the almost closed circular path of the pendulum is approximated by the limiting motion, while the motion in the vicinity…

  3. Large volume production of large size GaAs substrates and epitaxial wafers for microwave devices

    OpenAIRE

    Otoki, Y.; Kamogawa, H.; Ohnishi, M.; Inada, T.; Kashiwa, M.; Sakaguchi, H.

    1999-01-01

    Recent mass production techniques for LEC substrates and MOVPE wafers for microwave devices are described. Huge GaAs semi-insulating ingots (150mm diam., 310mm long) was obtained by Multi-hot-zone very large size pullar. Three step boule annealing and fully-automated process enabled mass production of the large size substrates. Epitaxiial wafers with abrupt hetero interface, excellent uniformity and reproducibility are producing largely by face down horizontal flow type MOVPE system, which ca...

  4. Unusual allometry for sexual size dimorphism in a cichlid where males are extremely larger than females

    Indian Academy of Sciences (India)

    Kazutaka Ota; Masanori Kohda; Tetsu Sato

    2010-06-01

    When males are the larger sex, a positive allometric relationship between male and female sizes is often found across populations of a single species (i.e. Rensch’s rule). This pattern is typically explained by a sexual selection pressure on males. Here, we report that the allometric relationship was negative across populations of a shell-brooding cichlid fish Lamprologus callipterus, although males are extremely larger than females. Male L. callipterus collect and defend empty snail shells in each of which a female breeds. We found that, across six populations, male and female sizes are positively correlated with not only sexual and fecundity selection indices, but also with shell sizes. Given their different reproductive behaviours, these correlations mean that males are required to be more powerful, and thus larger, to transport larger shells, while female bodies are reduced to the shell size to enable them to enter the shells. Among the three size selections (sexual selection, fecundity selection and shell size), shell size explained the allometry, suggesting that females are more strongly subject to size selection associated with shell size availability than males. However, the allometry was violated when considering an additional population where size-selection regimes of males differed from that of other populations. Therefore, sexual size allometry will be violated by body size divergence induced by multiple selection regimes.

  5. Extremely large-scale simulation of a Kardar-Parisi-Zhang model using graphics cards.

    Science.gov (United States)

    Kelling, Jeffrey; Ódo, Géza

    2011-12-01

    The octahedron model introduced recently has been implemented onto graphics cards, which permits extremely large-scale simulations via binary lattice gases and bit-coded algorithms. We confirm scaling behavior belonging to the two-dimensional Kardar-Parisi-Zhang universality class and find a surface growth exponent: β = 0.2415(15) on 2(17) × 2(17) systems, ruling out β = 1/4 suggested by field theory. The maximum speedup with respect to a single CPU is 240. The steady state has been analyzed by finite-size scaling and a growth exponent α = 0.393(4) is found. Correction-to-scaling-exponent are computed and the power-spectrum density of the steady state is determined. We calculate the universal scaling functions and cumulants and show that the limit distribution can be obtained by the sizes considered. We provide numerical fitting for the small and large tail behavior of the steady-state scaling function of the interface width.

  6. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    Science.gov (United States)

    Robertson, J. Gordon; Bland-Hawthorn, Joss

    2012-09-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably faster than for most spectrograph collimators, while maintaining diffraction-limited imaging quality. It is possible to obtain excellent performance despite these challenges. We also briefly consider the number of such spectrographs required, which can be reduced by full or partial adaptive optics correction, and/or moving towards longer wavelengths.

  7. Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

    CERN Document Server

    Robertson, J Gordon

    2012-01-01

    As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably ...

  8. High Performance Multivariate Visual Data Exploration for Extremely Large Data

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, Oliver; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes; Prabhat,

    2008-08-22

    One of the central challenges in modern science is the need to quickly derive knowledge and understanding from large, complex collections of data. We present a new approach that deals with this challenge by combining and extending techniques from high performance visual data analysis and scientific data management. This approach is demonstrated within the context of gaining insight from complex, time-varying datasets produced by a laser wakefield accelerator simulation. Our approach leverages histogram-based parallel coordinates for both visual information display as well as a vehicle for guiding a data mining operation. Data extraction and subsetting are implemented with state-of-the-art index/query technology. This approach, while applied here to accelerator science, is generally applicable to a broad set of science applications, and is implemented in a production-quality visual data analysis infrastructure. We conduct a detailed performance analysis and demonstrate good scalability on a distributed memory Cray XT4 system.

  9. Hydrological extremes : Improving simulations of flood and drought in large river basins

    NARCIS (Netherlands)

    Wanders, N.

    2015-01-01

    Hydrological extremes regularly occur in all regions of the world and as such have large impacts on society. Floods and drought are the most severe hydrological extremes, in terms of their societal impact and potential economic damage. These events are amongst the most costly natural disasters, due

  10. Spray deposition for making large size billet with swing atomizer

    Institute of Scientific and Technical Information of China (English)

    LI Jian-ping; LIU Tao; TANG Qing-yun; HAN Lei; ZHONG Jue

    2008-01-01

    The movement mode of the atomizer is a very important parameter during spray deposition process, which has direct influence on the size and surface texture of the billets. To resolve the problem of manufacturing large size billets, a method of spray deposition by the atomizer with off-center swing was put forward. The atomizer was driven by the alternating current servomotor to swing within 7° at varying speed. The influence of the atomizer parameters, such as translation of the atomizer, swing angle of the atomizer, substrate falling speed and spraying pressure, on the spray deposition was studied. The optimized parameters of the spray deposition process were obtained. The results show that the large size billets with uniform surface quality can be made through adjusting swing frequency and angle of the atomizer, offset distance of the atomizer and inclined angle of the substrate; the valid spray area will decrease and the dimension of top surface will reduce when pressure is less than 0.4 MPa within certain spray distance; meantime, the moving time and cooling time of the droplets are extended, which will lead to loose structure and bad densification. When the pressure, the swing angle and the eccentric offset of the atomization equal 0.5MPa, 7° and 60mm,respectively, large size billets with fine texture and diameter of 500mm can be produced.

  11. Evolution of precipitation extremes in two large ensembles of climate simulations

    Science.gov (United States)

    Martel, Jean-Luc; Mailhot, Alain; Talbot, Guillaume; Brissette, François; Ludwig, Ralf; Frigon, Anne; Leduc, Martin; Turcotte, Richard

    2017-04-01

    Recent studies project significant changes in the future distribution of precipitation extremes due to global warming. It is likely that extreme precipitation intensity will increase in a future climate and that extreme events will be more frequent. In this work, annual maxima daily precipitation series from the Canadian Earth System Model (CanESM2) 50-member large ensemble (spatial resolution of 2.8°x2.8°) and the Community Earth System Model (CESM1) 40-member large ensemble (spatial resolution of 1°x1°) are used to investigate extreme precipitation over the historical (1980-2010) and future (2070-2100) periods. The use of these ensembles results in respectively 1 500 (30 years x 50 members) and 1200 (30 years x 40 members) simulated years over both the historical and future periods. These large datasets allow the computation of empirical daily extreme precipitation quantiles for large return periods. Using the CanESM2 and CESM1 large ensembles, extreme daily precipitation with return periods ranging from 2 to 100 years are computed in historical and future periods to assess the impact of climate change. Results indicate that daily precipitation extremes generally increase in the future over most land grid points and that these increases will also impact the 100-year extreme daily precipitation. Considering that many public infrastructures have lifespans exceeding 75 years, the increase in extremes has important implications on service levels of water infrastructures and public safety. Estimated increases in precipitation associated to very extreme precipitation events (e.g. 100 years) will drastically change the likelihood of flooding and their extent in future climate. These results, although interesting, need to be extended to sub-daily durations, relevant for urban flooding protection and urban infrastructure design (e.g. sewer networks, culverts). Models and simulations at finer spatial and temporal resolution are therefore needed.

  12. Hydrological extremes : Improving simulations of flood and drought in large river basins

    OpenAIRE

    N. Wanders

    2015-01-01

    Hydrological extremes regularly occur in all regions of the world and as such have large impacts on society. Floods and drought are the most severe hydrological extremes, in terms of their societal impact and potential economic damage. These events are amongst the most costly natural disasters, due to their often large spatial extent and high societal impact. The main objective of this thesis is: To reduce uncertainty in simulations, reanalysis, monitoring, forecasting and projections of hydr...

  13. Extreme value prediction of the wave-induced vertical bending moment in large container ships

    DEFF Research Database (Denmark)

    Andersen, Ingrid Marie Vincent; Jensen, Jørgen Juncher

    2015-01-01

    in the present paper is based on time series of full scale measurements from three large container ships of 8600, 9400 and 14000 TEU. When carrying out the extreme value estimation the peak-over-threshold (POT) method combined with an appropriate extreme value distribution is applied. The choice of a proper...... increase the extreme hull girder response significantly. Focus in the present paper is on the influence of the hull girder flexibility on the extreme response amidships, namely the wave-induced vertical bending moment (VBM) in hogging, and the prediction of the extreme value of the same. The analysis...... threshold level as well as the statistical correlation between clustered peaks influence the extreme value prediction and are taken into consideration in the present paper....

  14. Predictable variation of range-sizes across an extreme environmental gradient in a lizard adaptive radiation: evolutionary and ecological inferences.

    Directory of Open Access Journals (Sweden)

    Daniel Pincheira-Donoso

    Full Text Available Large-scale patterns of current species geographic range-size variation reflect historical dynamics of dispersal and provide insights into future consequences under changing environments. Evidence suggests that climate warming exerts major damage on high latitude and elevation organisms, where changes are more severe and available space to disperse tracking historical niches is more limited. Species with longer generations (slower adaptive responses, such as vertebrates, and with restricted distributions (lower genetic diversity, higher inbreeding in these environments are expected to be particularly threatened by warming crises. However, a well-known macroecological generalization (Rapoport's rule predicts that species range-sizes increase with increasing latitude-elevation, thus counterbalancing the impact of climate change. Here, I investigate geographic range-size variation across an extreme environmental gradient and as a function of body size, in the prominent Liolaemus lizard adaptive radiation. Conventional and phylogenetic analyses revealed that latitudinal (but not elevational ranges significantly decrease with increasing latitude-elevation, while body size was unrelated to range-size. Evolutionarily, these results are insightful as they suggest a link between spatial environmental gradients and range-size evolution. However, ecologically, these results suggest that Liolaemus might be increasingly threatened if, as predicted by theory, ranges retract and contract continuously under persisting climate warming, potentially increasing extinction risks at high latitudes and elevations.

  15. Multispectral Acquisition of Large-Sized Pictorial Surfaces

    Directory of Open Access Journals (Sweden)

    Paviotti Anna

    2009-01-01

    Full Text Available Multispectral acquisition of artworks has recently received considerable attention in the image processing community. Quite understandably, so far this attention has mainly focused on paintings, given their predominant role in museum collections. It is worth pointing out that the instrumentation and procedures used for acquiring regular paintings are not suited for the multispectral acquisition of large-sized painted surfaces such as frescoed halls and great paintings. Given the relevance of such artifacts, and their widespread presence in churches or historical buildings due to their social function, the problem of finding suitable techniques for their acquisition is certainly worth addressing. This paper focuses on multispectral acquisition of large-sized pictorial surfaces, systematically addressing the practical issues related to the acquisition equipment and procedure. Given the crucial role played by the illumination in this application, special attention is given to this issue. The proposed approach is supported by experimental results.

  16. Accuracy of the photogrametric measuring system for large size elements

    Directory of Open Access Journals (Sweden)

    M. Grzelka

    2011-04-01

    Full Text Available The aim of this paper is to present methods of estimating and guidelines for verifying the accuracy of optical photogrammetric measuringsystems, using for measurement of large size elements. Measuring systems applied to measure workpieces of a large size which oftenreach more than 10000mm require use of appropriate standards. Those standards provided by the manufacturer of photogrammetricsystems are certified and are inspected annually. To make sure that these systems work properly there was developed a special standardVDI / VDE 2634, "Optical 3D measuring systems. Imaging systems with point - by - point probing. " According to recommendationsdescribed in this standard research on accuracy of photogrametric measuring system was conducted using K class gauge blocks dedicatedto calibrate and test accuracy of classic CMMs. The paper presents results of research of estimation the actual error of indication for sizemeasurement MPEE for photogrammetric coordinate measuring system TRITOP.

  17. Technological Aspects of Creating Large-size Optical Telescopes

    Directory of Open Access Journals (Sweden)

    V. V. Sychev

    2015-01-01

    Full Text Available A concept of the telescope creation, first of all, depends both on a choice of the optical scheme to form optical radiation and images with minimum losses of energy and information and on a choice of design to meet requirements for strength, stiffness, and stabilization characteristics in real telescope operation conditions. Thus, the concept of creating large-size telescopes, certainly, involves the use of adaptive optics methods and means.The level of technological capabilities to realize scientific and engineering ideas define a successful development of large-size optical telescopes in many respects. All developers pursue the same aim that is to raise an amount of information by increasing a main mirror diameter of the telescope.The article analyses the adaptive telescope designs developed in our country. Using a domestic ACT-25 telescope as an example, it considers creation of large-size optical telescopes in terms of technological aspects. It also describes the telescope creation concept features, which allow reaching marginally possible characteristics to ensure maximum amount of information.The article compares a wide range of large-size telescopes projects. It shows that a domestic project to create the adaptive ACT-25 super-telescope surpasses its foreign counterparts, and there is no sense to implement Euro50 (50m and OWL (100m projects.The considered material gives clear understanding on a role of technological aspects in development of such complicated optic-electronic complexes as a large-size optical telescope. The technological criteria of an assessment offered in the article, namely specific informational content of the telescope, its specific mass, and specific cost allow us to reveal weaknesses in the project development and define a reserve regarding further improvement of the telescope.The analysis of results and their judgment have shown that improvement of optical largesize telescopes in terms of their maximum

  18. Relationship between climate extremes in Romania and their connection to large-scale air circulation

    Science.gov (United States)

    Barbu, Nicu; Ştefan, Sabina

    2015-04-01

    The aim of this paper is to investigate the connection between climate extremes (temperature and precipitation) in Romania and large-scale air circulation. Daily observational data of maximum air temperature and amount of precipitation for the period 1961-2010 were used to compute two seasonal indices associated with temperature and precipitation, quantifying their frequency, as follows: frequency of very warm days (FTmax90 ≥ 90th percentile), frequency of very wet days (FPp90; daily precipitation amount ≥ 90th percentile). Seasonally frequency of circulation types were calculated from daily circulation types determined by using two objective catalogues (GWT - GrossWetter-Typen and WLK - WetterLargenKlassifikation) from the COST733Action. Daily reanalysis data sets (sea level pressure, geopotential height at 925 and 500 hPa, u and v components of wind vector at 700 hPa and precipitable water content for the entire atmospheric column) build up by NCEP/NCAR, with 2.5°/2.5° lat/lon spatial resolution, were used to determine the circulation types. In order to select the optimal domain size related to the FTmax90 and the FPp90, the explained variance (EV) has been used. The EV determines the relation between the variance among circulation types and the total variance of the variable under consideration. This method quantifies the discriminatory power of a classification. The relationships between climate extremes in Romania and large-scale air circulation were investigated by using multiple linear regression model (MLRM), the predictands are FTmax90 and FPp90 and the circulation types were used as predictors. In order to select the independent predictors to build the MLRM the collinearity and multicollinearity analysis were performed. The study period is dividend in two periods: the period 1961-2000 is used to train the MLRM and the period 2001-2010 is used to validate the MLRM. The analytical relationship obtained by using MLRM can be used for future projection

  19. Nuclear states with anomalously large radius (size isomers)

    Energy Technology Data Exchange (ETDEWEB)

    Ogloblin, A. A.; Demyanova, A. S., E-mail: a.s.demyanova@bk.ru; Danilov, A. N. [National Research Center Kurchatov Institute (Russian Federation); Belyaeva, T. L. [Ciudad Universitaria, Universidad Nacional Autónoma de Meéxico (Mexico); Goncharov, S. A. [Moscow State University, Faculty of Physics (Russian Federation); Trzaska, W. [University of Jyvaäskylaä (Finland)

    2016-07-15

    Methods of determination of the nuclear excited state radii are discussed together with the recently obtained data on the states of some light nuclei having abnormally large radii (size isomers). It is shown that such states include excited neutron-halo states in {sup 9}Be, {sup 11}Be, and {sup 13}C and some alpha-cluster states in {sup 12}C, {sup 11}B, and {sup 13}C. Among the latter ones, there is the well-known Hoyle state in {sup 12}C—the structure of this state exhibit rudimentary features of alpha-particle states.

  20. Trends in Mediterranean gridded temperature extremes and large-scale circulation influences

    Directory of Open Access Journals (Sweden)

    D. Efthymiadis

    2011-08-01

    Full Text Available Two recently-available daily gridded datasets are used to investigate trends in Mediterranean temperature extremes since the mid-20th century. The underlying trends are found to be generally consistent with global trends of temperature and their extremes: cold extremes decrease and warm/hot extremes increase. This consistency is better manifested in the western part of the Mediterranean where changes are most pronounced since the mid-1970s. In the eastern part, a cooling is observed, with a near reversal in the last two decades. This inter-basin discrepancy is clearer in winter, while in summer changes are more uniform and the west-east difference is restricted to the rate of increase of warm/hot extremes, which is higher in central and eastern parts of the Mediterranean over recent decades. Linear regression and correlation analysis reveals some influence of major large-scale atmospheric circulation patterns on the occurrence of these extremes – both in terms of trend and interannual variability. These relationships are not, however, able to account for the most striking features of the observations – in particular the intensification of the increasing trend in warm/hot extremes, which is most evident over the last 15–20 yr in the Central and Eastern Mediterranean.

  1. Vertebral Adaptations to Large Body Size in Theropod Dinosaurs

    Science.gov (United States)

    Wilson, John P.; Woodruff, D. Cary; Gardner, Jacob D.; Flora, Holley M.; Horner, John R.; Organ, Chris L.

    2016-01-01

    Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not. PMID:27442509

  2. Vertebral Adaptations to Large Body Size in Theropod Dinosaurs.

    Directory of Open Access Journals (Sweden)

    John P Wilson

    Full Text Available Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.

  3. Vertebral Adaptations to Large Body Size in Theropod Dinosaurs.

    Science.gov (United States)

    Wilson, John P; Woodruff, D Cary; Gardner, Jacob D; Flora, Holley M; Horner, John R; Organ, Chris L

    2016-01-01

    Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.

  4. Multifrequency sensing of large-sized dielectric boards

    Science.gov (United States)

    Volgyi, Ferenc

    2000-07-01

    After introducing some possibilities and related problems of microwave moisture measurements, a non-destructive testing method of large-sized dielectric boards is shown, which is based on a microwave free-space/double transmission/reflection type two-parameter complex vector measurement. Unlike this basic idea, a 5.8 GHz monitoring system was developed, which is used for moisture content measurement and quality forecast of particleboards continuously, before mechanical testing would be accomplished. Recalling some basic equations, the calculation of Kasa's circles, dry wood basic weight, complex permittivity values, absolute moisture content and mechanical properties of composite boards, also are shown. Low cost MMICs, self-designed microstrip antennas and passive detector/backscatters are used in the instrumentation for the realization of the concept.

  5. An alternative method for determining particle-size distribution of forest road aggregate and soil with large-sized particles

    Science.gov (United States)

    Hakjun Rhee; Randy B. Foltz; James L. Fridley; Finn Krogstad; Deborah S. Page-Dumroese

    2014-01-01

    Measurement of particle-size distribution (PSD) of soil with large-sized particles (e.g., 25.4 mm diameter) requires a large sample and numerous particle-size analyses (PSAs). A new method is needed that would reduce time, effort, and cost for PSAs of the soil and aggregate material with large-sized particles. We evaluated a nested method for sampling and PSA by...

  6. Larger trinucleotide repeat size in the androgen receptor gene of infertile men with extremely severe oligozoospermia.

    Science.gov (United States)

    Patrizio, P; Leonard, D G; Chen, K L; Hernandez-Ayup, S; Trounson, A O

    2001-01-01

    Androgens are significant regulators of human spermatogenesis. Their action is mediated through the androgen receptor (AR), which binds to the androgen responsive element on DNA and regulates gene transcription. Men become infertile with spinobulbar muscular atrophy (Kennedy disease) caused by a trinucleotide repeat expansion, > or = 40 CAG repeats, in the AR gene located on the X chromosome. In this prospective study, we investigated whether the variable size, larger repeats, of this trinucleotide could alter AR function and result in impaired spermatogenesis. A total of 69 infertile men were studied. Clinical and laboratory analysis showed idiopathic, nonobstructive azoospermia in 16 men, extremely severe oligozoospermia in 27 men (PCR) amplification across the AR repeat region. Accurate size determination of the PCR product using an ABI 373 DNA sequencer allowed precise calculation of CAG repeat sizes. The AR gene was not analyzed for other types of mutations. The difference in CAG repeat size between infertile men and proven fertile controls was statistically significant, P = .03. Patients with extremely severe oligozoospermia had significantly longer CAG repeat tracts (mean, 25.4 +/- 4.0; P = .0005; range 20-39) than controls (mean, 22 +/- 2.8; range 12-30) or patients with severe oligozoospermia (mean, 22.2 +/- 2.3; range 18-26). None of the 26 infertile men with sperm counts CAG repeats compared with 6 out of 45 controls (13%; P = .06). This study suggests that some men with severe impairment of spermatogenesis have longer trinucleotide repeats in the AR gene. Although direct evidence is missing, lower affinity between androgen and the AR protein or decreased AR protein availability with longer repeats could be responsible for a diminished androgen effect on spermatogenesis. Two of the patients in the extremely severe oligozoospermia group had 35 and 39 CAG repeats, respectively (normal range is 11 to 33). Although not yet considered a mutation, longer

  7. Populating the Large-Wavevector Realm: Bloch Volume Plasmon Polaritons in Hyperbolic and Extremely Anisotropic Metamaterials

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Babicheva, Viktoriia; Orlov, A. A.

    2014-01-01

    Optics of hyperbolic metamaterials is revisited in terms of large-wavevector waves, evanescent in isotropic media but propagating in presence of extreme anisotropy. Identifying the physical nature of these waves as Bloch volume plasmon polaritons, we derive their existence conditions and outline...... the strategy for tailoring their properties in multiscale metamaterials....

  8. Revisiting extreme storms of the past 100 years for future safety of large water management infrastructures

    Science.gov (United States)

    Chen, Xiaodong; Hossain, Faisal

    2016-07-01

    Historical extreme storm events are widely used to make Probable Maximum Precipitation (PMP) estimates, which form the cornerstone of large water management infrastructure safety. Past studies suggest that extreme precipitation processes can be sensitive to land surface feedback and the planetary warming trend, which makes the future safety of large infrastructures questionable given the projected changes in land cover and temperature in the coming decades. In this study, a numerical modeling framework was employed to reconstruct 10 extreme storms over CONUS that occurred during the past 100 years, which are used by the engineering profession for PMP estimation for large infrastructures such as dams. Results show that the correlation in daily rainfall for such reconstruction can range between 0.4 and 0.7, while the correlation for maximum 3-day accumulation (a standard period used in infrastructure design) is always above 0.5 for post-1948 storms. This suggests that current numerical modeling and reanalysis data allow us to reconstruct big storms after 1948 with acceptable accuracy. For storms prior to 1948, however, reconstruction of storms shows inconsistency with observations. Our study indicates that numerical modeling and data may not have advanced to a sufficient level to understand how such old storms (pre-1948) may behave in future warming and land cover conditions. However, the infrastructure community can certainly rely on the use of model reconstructed extreme storms of the 1948-present period to reassess safety of our large water infrastructures under assumed changes in temperature and land cover.

  9. The scaling relationship between telescope cost and aperture size for very large telescopes

    Science.gov (United States)

    van Belle, Gerard T.; Meinel, Aden Baker; Meinel, Marjorie Pettit

    2004-01-01

    Cost data for ground-based telescopes of the last century are analyzed for trends in the relationship between aperture size and cost. We find that for apertures built prior to 1980, costs scaled as aperture size to the 2.8 power, which is consistent with the precious finding of Meinel (1978). After 1980, 'traditional' monolithic mirror telescope costs have scaled as aperture to the 2.5 power. The large multiple mirror telescopes built or in construction during this time period (Keck, LBT, GTC) appear to deviate from this relationship with significant cost savings as a result, although it is unclear what power law such structures follow. We discuss the implications of the current cost-aperture size data on the proposed large telescope projects of the next ten to twenty years. Structures that naturally tend towards the 2.0 power in the cost-aperture relationship will be the favorable choice for future extremely large apertures; out expectation is that space-based structures will ultimately gain economic advantage over ground-based ones.

  10. Application of Nanometer-Size Titanium Dioxide in Extreme-Trace V(Ⅴ) Analysis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The adsorption properties of nanometer-size TiO2 for V(Ⅴ) were studied. The adsorption rate could reach above 99% when the pH values were at the range of 4-10. The adsorption balance time was 10 min , the saturation capacity of adsorption of nanometer-size TiO2 to V(Ⅴ) was 6.43 mg per gram. Using 2 mL 1.5 mol·L-1 NaOH as elution, we found the elution rate could reach 95%. A novel method of extreme-trace V(Ⅴ) preconcentration with nanometer-size titanium dioxide and determination by graphite furnace atomic absorption spectroscopy (GFAAS) was advanced. The detection limit(3σ)of the method was 0.61 μg·L-1, and the relative standard deviation was 8.1% (n=6) of 2.5 μg·L-1 V(Ⅴ). Environmental samples experiments were also conducted to test the feasibility of the method, and it came out that the recovery rates were between 91.2% and 102.0%.

  11. Processing and properties of large-sized ceramic slabs

    Directory of Open Access Journals (Sweden)

    Fossa, L.

    2010-10-01

    Full Text Available Large-sized ceramic slabs – with dimensions up to 360x120 cm2 and thickness down to 2 mm – are manufactured through an innovative ceramic process, starting from porcelain stoneware formulations and involving wet ball milling, spray drying, die-less slow-rate pressing, a single stage of fast drying-firing, and finishing (trimming, assembling of ceramic-fiberglass composites. Fired and unfired industrial slabs were selected and characterized from the technological, compositional (XRF, XRD and microstructural (SEM viewpoints. Semi-finished products exhibit a remarkable microstructural uniformity and stability in a rather wide window of firing schedules. The phase composition and compact microstructure of fired slabs are very similar to those of porcelain stoneware tiles. The values of water absorption, bulk density, closed porosity, functional performances as well as mechanical and tribological properties conform to the top quality range of porcelain stoneware tiles. However, the large size coupled with low thickness bestow on the slab a certain degree of flexibility, which is emphasized in ceramic-fiberglass composites. These outstanding performances make the large-sized slabs suitable to be used in novel applications: building and construction (new floorings without dismantling the previous paving, ventilated façades, tunnel coverings, insulating panelling, indoor furnitures (table tops, doors, support for photovoltaic ceramic panels.

    Se han fabricado piezas de gran formato, con dimensiones de hasta 360x120 cm, y menos de 2 mm, de espesor, empleando métodos innovadores de fabricación, partiendo de composiciones de gres porcelánico y utilizando, molienda con bolas por vía húmeda, atomización, prensado a baja velocidad sin boquilla de extrusión, secado y cocción rápido en una sola etapa, y un acabado que incluye la adhesión de fibra de vidrio al soporte cerámico y el rectificado de la pieza final. Se han

  12. IBAR: Interacting boson model calculations for large system sizes

    Science.gov (United States)

    Casperson, R. J.

    2012-04-01

    Scaling the system size of the interacting boson model-1 (IBM-1) into the realm of hundreds of bosons has many interesting applications in the field of nuclear structure, most notably quantum phase transitions in nuclei. We introduce IBAR, a new software package for calculating the eigenvalues and eigenvectors of the IBM-1 Hamiltonian, for large numbers of bosons. Energies and wavefunctions of the nuclear states, as well as transition strengths between them, are calculated using these values. Numerical errors in the recursive calculation of reduced matrix elements of the d-boson creation operator are reduced by using an arbitrary precision mathematical library. This software has been tested for up to 1000 bosons using comparisons to analytic expressions. Comparisons have also been made to the code PHINT for smaller system sizes. Catalogue identifier: AELI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 28 734 No. of bytes in distributed program, including test data, etc.: 4 104 467 Distribution format: tar.gz Programming language: C++ Computer: Any computer system with a C++ compiler Operating system: Tested under Linux RAM: 150 MB for 1000 boson calculations with angular momenta of up to L=4 Classification: 17.18, 17.20 External routines: ARPACK (http://www.caam.rice.edu/software/ARPACK/) Nature of problem: Construction and diagonalization of large Hamiltonian matrices, using reduced matrix elements of the d-boson creation operator. Solution method: Reduced matrix elements of the d-boson creation operator have been stored in data files at machine precision, after being recursively calculated with higher than machine precision. The Hamiltonian matrix is calculated and diagonalized, and the requested transition strengths are calculated

  13. Renormalization-group theory for finite-size scaling in extreme statistics.

    Science.gov (United States)

    Györgyi, G; Moloney, N R; Ozogány, K; Rácz, Z; Droz, M

    2010-04-01

    We present a renormalization-group (RG) approach to explain universal features of extreme statistics applied here to independent identically distributed variables. The outlines of the theory have been described in a previous paper, the main result being that finite-size shape corrections to the limit distribution can be obtained from a linearization of the RG transformation near a fixed point, leading to the computation of stable perturbations as eigenfunctions. Here we show details of the RG theory which exhibit remarkable similarities to the RG known in statistical physics. Besides the fixed points explaining universality, and the least stable eigendirections accounting for convergence rates and shape corrections, the similarities include marginally stable perturbations which turn out to be generic for the Fisher-Tippett-Gumbel class. Distribution functions containing unstable perturbations are also considered. We find that, after a transitory divergence, they return to the universal fixed line at the same or at a different point depending on the type of perturbation.

  14. Design issues for the active control system of the California Extremely Large Telescope (CELT)

    Science.gov (United States)

    Chanan, Gary A.; Nelson, Jerry E.; Ohara, Catherine M.; Sirko, Edwin

    2000-08-01

    We explore the issues in the control and alignment of the primary mirror of the proposed 30 meter California Extremely Large Telescope and other very large telescopes with segmented primaries (consisting of 1000 or more segments). We show that as the number of segments increases, the noise in the telescope active control system (ACS) increases, roughly as (root)n. This likely means that, for a thousand segment telescope like CELT, Keck-style capacitive sensors will not be able to adequately monitor the lowest spatial frequency degrees of freedom of the primary mirror, and will therefore have to be supplemented by a Shack-Hartmann-type wavefront sensor. However, in the case of segment phasing, which is governed by a `control matrix' similar to that of the ACS, the corresponding noise is virtually independent of n. It follows that reasonably straightforward extensions of current techniques should be adequate to phase the extremely large telescopes of the future.

  15. Excessive portal flow causes graft failure in extremely small-for-size liver transplantation in pigs

    Institute of Scientific and Technical Information of China (English)

    Hong-Sheng Wang; Tomohiro Narita; Hideyuki Yamaya; Atsushi Nakamura; Satoshi Sekiguchi; Naoki Kawagishi; Akira Sato; Susumu Satomi; Nobuhiro Ohkohchi; Yoshitaka Enomoto; Masahiro Usuda; Shigehito Miyagi; Takeshi Asakura; Hiroo Masuoka; Takashi Aiso; Keisuke Fukushima

    2005-01-01

    AIM: To evaluate the effects of a portocaval shunt on the decrease of excessive portal flow for the prevention of sinusoidal microcirculatory injury in extremely smallfor-size liver transplantation in pigs.METHODS: The right lateral lobe of pigs, i.e. the 25%of the liver, was transplanted orthotopically. The pigs were divided into two groups: graft without portocaval shunt (n = 11) and graft with portocaval shunt (n=11).Survival rate, portal flow, hepatic arterial flow, and histological findings were investigated.RESULTS: In the group without portocaval shunt, all pigs except one died of liver dysfunction within 24 h after transplantation. In the group with portocaval shunt,eight pigs survived for more than 4 d. The portal flow volumes before and after transplantation in the group without portocaval shunt were 118.2±26.9 mL/min/100 g liver tissue and 270.5±72.9 mL/min/100 g liver tissue,respectively. On the other hand, in the group with portocaval shunt, those volumes were 124.2±27.8 mL/min/100 g liver tissue and 42.7±32.3 mL/min/100 g liver tissue, respectively (P<0.01). As for histological findings in the group without portocaval shunt, destruction of the sinusoidal lining and bleeding in the peri-portal areas were observed after reperfusion, but these findings were not recognized in the group with portocaval shunt.CONCLUSION: These results suggest that excessive portal flow is attributed to post transplant liver dysfunction after extreme small-for-size liver transplantation caused by sinusoidal microcirculatory injury.

  16. Influence of Lower Extremity Muscle Size and Quality on Stair-Climb Performance in Career Firefighters.

    Science.gov (United States)

    Kleinberg, Craig R; Ryan, Eric D; Tweedell, Andrew J; Barnette, Timothy J; Wagoner, Chad W

    2016-06-01

    The purpose of this study was to examine the influence of lower extremity muscular size and quality on stair-climb performance (SCP) in career firefighters. Forty-six male career firefighters (age = 37.0 ± 7.2 years; stature = 180.2 ± 6.9 cm; body mass = 108.0 ± 19.8 kg) volunteered for this study. Panoramic ultrasound images of the vastus lateralis and rectus femoris were obtained to determine cross-sectional area (CSA) and echo intensity (EI) of each muscle. The CSA of each muscle was then summed together and normalized to body mass (CSA/BM [QCSA]). Additionally, EI was averaged across both muscles (QEI). Participants then performed a timed and weighted SCP assessment where they ascended and descended 26 stairs 4 times as quickly as possible while wearing a weighted vest (22.73 kg) to simulate the weight of their self-contained breathing apparatus and turnout gear. Bivariate correlations and stepwise regression analyses were used to examine the relationships among variables and the relative contributions of QCSA and QEI to SCP. Partial correlations were used to examine the relationship between QCSA and SCP and QEI and SCP while controlling for age and body mass index (BMI). The results indicated that QCSA and QEI were significantly related to SCP before (r = -0.492, p = 0.001; r = 0.363, p = 0.013, respectively) and after accounting for age and BMI (r = -0.324, p = 0.032; r = 0.413, p = 0.005, respectively). Both QCSA and QEI contributed significantly to the prediction of SCP (r = 0.560, p < 0.001). These findings indicate that lower extremity muscle size and quality are important contributors to critical firefighting tasks, which have been shown to be improved with resistance training.

  17. Status of the Cherenkov Telescope Array's Large Size Telescopes

    CERN Document Server

    Cortina, J

    2015-01-01

    The Cherenkov Telescope Array (CTA) observatory, will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 PMTs and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is well underway. In 2016 the first LST will be installed at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain). In this talk we will outline the technical solutions adopted to fulfill the design requirem...

  18. Implications of extreme sexual size dimorphism for thermoregulation in a freshwater turtle.

    Science.gov (United States)

    Bulté, Grégory; Blouin-Demers, Gabriel

    2010-02-01

    Sexual size dimorphism (SSD) is a common phenomenon in animals. In many species females are substantially larger than males. Because body size plays a central role in modulating the body temperature (T (b)) of ectotherms, intersexual differences in body size may lead to important intersexual differences in thermoregulation. In addition, because SSD is realized by differences in growth rate and because growth rate is strongly temperature dependent in ectotherms, a conflict between male reproductive behaviour and thermoregulation may affect the expression of SSD. In this study, we investigated the thermal implications of SSD in a reptile exhibiting spectacular female-biased SSD: the northern map turtle (Graptemys geographica). Over three seasons, we collected >150,000 measurements of T (b) in free-ranging adult and juvenile northern map turtles using surgically implanted miniature temperature loggers. Northern map turtles exhibited seasonal patterns of thermoregulation typical of reptiles in northern latitudes, but we found that large adult females experienced a lower daily maximum T (b) and a narrower daily range of T (b) than adult males and small juvenile females. In addition, despite more time spent basking, large adult females were not able to thermoregulate as accurately as small turtles. Our findings strongly suggest that body size limits the ability to thermoregulate accurately in large females. By comparing thermoregulatory patterns between adult males and juvenile females of similar body size, we found no evidence that male reproductive behaviours are an impediment to thermoregulation. We also quantified the thermal significance of basking behaviour. We found, contrary to previous findings, that aerial basking allows northern map turtles to raise their T (b) substantially above water temperature, indicating that basking behaviour likely plays an important role in thermoregulation.

  19. MAD about the Large Magellanic Cloud: preparing for the era of Extremely Large Telescopes

    CERN Document Server

    Fiorentino, G; Diolaiti, E; Valenti, E; Cignoni, M; Mackey, A D

    2011-01-01

    We present J, H, Ks photometry from the the Multi conjugate Adaptive optics Demonstrator (MAD), a visitor instrument at the VLT, of a resolved stellar population in a small crowded field in the bar of the Large Magellanic Cloud near the globular cluster NGC 1928. In a total exposure time of 6, 36 and 20 minutes, magnitude limits were achieved of J \\sim 20.5 mag, H \\sim 21 mag, and Ks \\sim20.5 mag respectively, with S/N> 10. This does not reach the level of the oldest Main Sequence Turnoffs, however the resulting Colour-Magnitude Diagrams are the deepest and most accurate obtained so far in the infrared for the LMC bar. We combined our photometry with deep optical photometry from the Hubble Space Telescope/Advanced Camera for Surveys, which is a good match in spatial resolution. The comparison between synthetic and observed CMDs shows that the stellar population of the field we observed is consistent with the star formation history expected for the LMC bar, and that all combinations of IJHKs filters can, with ...

  20. Comparison of coronagraphs for high contrast imaging in the context of Extremely Large Telescopes

    CERN Document Server

    Martínez, P; Kasper, M; Cavarroc, C; Yaitskova, N; Fusco, T; Verinaud, C

    2008-01-01

    We compare coronagraph concepts and investigate their behavior and suitability for planet finder projects with Extremely Large Telescopes (ELTs, 30-42 meters class telescopes). For this task, we analyze the impact of major error sources that occur in a coronagraphic telescope (central obscuration, secondary support, low-order segment aberrations, segment reflectivity variations, pointing errors) for phase, amplitude and interferometric type coronagraphs. This analysis is performed at two different levels of the detection process: under residual phase left uncorrected by an eXtreme Adaptive Optics system (XAO) for a large range of Strehl ratio and after a general and simple model of speckle calibration, assuming common phase aberrations between the XAO and the coronagraph (static phase aberrations of the instrument) and non-common phase aberrations downstream of the coronagraph (differential aberrations provided by the calibration unit). We derive critical parameters that each concept will have to cope with by...

  1. Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yongkang, E-mail: ykluo@lanl.gov; Dai, Y. M.; Taylor, A. J.; Yarotski, D. A.; Prasankumar, R. P.; Thompson, J. D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Li, H.; Miao, H.; Shi, Y. G. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Ding, H. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China)

    2015-11-02

    We systematically measured the Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}. By carefully fitting the Hall resistivity to a two-band model, the temperature dependencies of the carrier density and mobility for both electron- and hole-type carriers were determined. We observed a sudden increase in the hole density below ∼160 K, which is likely associated with the temperature-induced Lifshitz transition reported by a previous photoemission study. In addition, a more pronounced reduction in electron density occurs below 50 K, giving rise to comparable electron and hole densities at low temperature. Our observations indicate a possible electronic structure change below 50 K, which might be the direct driving force of the electron-hole “compensation” and the extremely large magnetoresistance as well. Numerical simulations imply that this material is unlikely to be a perfectly compensated system.

  2. Large Differences in Bacterial Community Composition among Three Nearby Extreme Waterbodies of the High Andean Plateau.

    Science.gov (United States)

    Aguilar, Pablo; Acosta, Eduardo; Dorador, Cristina; Sommaruga, Ruben

    2016-01-01

    The high Andean plateau or Altiplano contains different waterbodies that are subjected to extreme fluctuations in abiotic conditions on a daily and an annual scale. The bacterial diversity and community composition of those shallow waterbodies is largely unexplored, particularly, of the ponds embedded within the peatland landscape (i.e., Bofedales). Here we compare the small-scale spatial variability (Altiplano peatland ponds represent a hitherto unknown source of microbial diversity.

  3. Weather extremes in very large, high-resolution ensembles: the weatherathome experiment

    Science.gov (United States)

    Allen, M. R.; Rosier, S.; Massey, N.; Rye, C.; Bowery, A.; Miller, J.; Otto, F.; Jones, R.; Wilson, S.; Mote, P.; Stone, D. A.; Yamazaki, Y. H.; Carrington, D.

    2011-12-01

    Resolution and ensemble size are often seen as alternatives in climate modelling. Models with sufficient resolution to simulate many classes of extreme weather cannot normally be run often enough to assess the statistics of rare events, still less how these statistics may be changing. As a result, assessments of the impact of external forcing on regional climate extremes must be based either on statistical downscaling from relatively coarse-resolution models, or statistical extrapolation from 10-year to 100-year events. Under the weatherathome experiment, part of the climateprediction.net initiative, we have compiled the Met Office Regional Climate Model HadRM3P to run on personal computer volunteered by the general public at 25 and 50km resolution, embedded within the HadAM3P global atmosphere model. With a global network of about 50,000 volunteers, this allows us to run time-slice ensembles of essentially unlimited size, exploring the statistics of extreme weather under a range of scenarios for surface forcing and atmospheric composition, allowing for uncertainty in both boundary conditions and model parameters. Current experiments, developed with the support of Microsoft Research, focus on three regions, the Western USA, Europe and Southern Africa. We initially simulate the period 1959-2010 to establish which variables are realistically simulated by the model and on what scales. Our next experiments are focussing on the Event Attribution problem, exploring how the probability of various types of extreme weather would have been different over the recent past in a world unaffected by human influence, following the design of Pall et al (2011), but extended to a longer period and higher spatial resolution. We will present the first results of the unique, global, participatory experiment and discuss the implications for the attribution of recent weather events to anthropogenic influence on climate.

  4. Large-scale Agroecosytem's Resiliency to Extreme Hydrometeorological and Climate Extreme Events in the Missouri River Basin

    Science.gov (United States)

    Munoz-Arriola, F.; Smith, K.; Corzo, G.; Chacon, J.; Carrillo-Cruz, C.

    2015-12-01

    A major challenge for water, energy and food security relies on the capability of agroecosyststems and ecosystems to adapt to a changing climate and land use changes. The interdependency of these forcings, understood through our ability to monitor and model processes across scales, indicate the "depth" of their impact on agroecosystems and ecosystems, and consequently our ability to predict the system's ability to return to a "normal" state. We are particularly interested in explore two questions: (1) how hydrometeorological and climate extreme events (HCEs) affect sub-seasonal to interannual changes in evapotranspiration and soil moisture? And (2) how agroecosystems recover from the effect of such events. To address those questions we use the land surface hydrologic Variable Infiltration Capacity (VIC) model and the Moderate Resolution Imaging Spectrometer-Leaf Area Index (MODIS-LAI) over two time spans (1950-2013 using a seasonal fixed LAI cycle) and 2001-2013 (an 8-day MODIS-LAI). VIC is forced by daily/16th degree resolution precipitation, minimum and maximum temperature, and wind speed. In this large-scale experiment, resiliency is defined by the capacity of a particular agroecosystem, represented by a grid cell's ET, SM, and LAI to return to a historical average. This broad, yet simplistic definition will contribute to identify the possible components and their scales involved in agroecosystems and ecosystems capacity to adapt to the incidence of HCEs and technologies used to intensify agriculture and diversify their use for food and energy production. Preliminary results show that dynamical changes in land use, tracked by MODIS data, require larger time spans to address properly the influence of technologic improvements in crop production as well as the competition for land for biofuel vs. food production. On the other hand, fixed seasonal changes in land use allow us just to identify hydrologic changes mainly due to climate variability.

  5. A Novel Read Scheme for Large Size One-Resistor Resistive Random Access Memory Array.

    Science.gov (United States)

    Zackriya, Mohammed; Kittur, Harish M; Chin, Albert

    2017-02-10

    The major issue of RRAM is the uneven sneak path that limits the array size. For the first time record large One-Resistor (1R) RRAM array of 128x128 is realized, and the array cells at the worst case still have good Low-/High-Resistive State (LRS/HRS) current difference of 378 nA/16 nA, even without using the selector device. This array has extremely low read current of 9.7 μA due to both low-current RRAM device and circuit interaction, where a novel and simple scheme of a reference point by half selected cell and a differential amplifier (DA) were implemented in the circuit design.

  6. A Novel Read Scheme for Large Size One-Resistor Resistive Random Access Memory Array

    Science.gov (United States)

    Zackriya, Mohammed; Kittur, Harish M.; Chin, Albert

    2017-01-01

    The major issue of RRAM is the uneven sneak path that limits the array size. For the first time record large One-Resistor (1R) RRAM array of 128x128 is realized, and the array cells at the worst case still have good Low-/High-Resistive State (LRS/HRS) current difference of 378 nA/16 nA, even without using the selector device. This array has extremely low read current of 9.7 μA due to both low-current RRAM device and circuit interaction, where a novel and simple scheme of a reference point by half selected cell and a differential amplifier (DA) were implemented in the circuit design. PMID:28186147

  7. Observation of an Extremely Large-Density Heliospheric Plasma Sheet Compressed by an Interplanetary Shock at 1 AU

    Science.gov (United States)

    Wu, Chin-Chun; Liou, Kan; Lepping, R. P.; Vourlidas, Angelos; Plunkett, Simon; Socker, Dennis; Wu, S. T.

    2017-08-01

    At 11:46 UT on 9 September 2011, the Wind spacecraft encountered an interplanetary (IP) fast-forward shock. The shock was followed almost immediately by a short-duration (˜ 35 minutes) extremely dense pulse (with a peak ˜ 94 cm-3). The pulse induced an extremely large positive impulse (SYM-H = 74 nT and Dst = 48 nT) on the ground. A close examination of other in situ parameters from Wind shows that the density pulse was associated with i) a spike in the plasma β (ratio of thermal to magnetic pressure), ii) multiple sign changes in the azimuthal component of the magnetic field (B_{φ}), iii) a depressed magnetic field magnitude, iv) a small radial component of the magnetic field, and v) a large (> 90°) change in the suprathermal (˜ 255 eV) electron pitch angle across the density pulse. We conclude that the density pulse is associated with the heliospheric plasma sheet (HPS). The thickness of the HPS is estimated to be {˜} 8.2×105 km. The HPS density peak is about five times the value of a medium-sized density peak inside the HPS (˜ 18 cm-3) at 1 AU. Our global three-dimensional magnetohydrodynamic simulation results (Wu et al. in J. Geophys. Res. 212, 1839, 2016) suggest that the extremely large density pulse may be the result of the compression of the HPS by an IP shock crossing or an interaction between an interplanetary shock and a corotating interaction region.

  8. European Extremely Large Telescope: some history, and the scientific community's preferences for wavelength

    Science.gov (United States)

    Gilmore, Gerard

    2008-04-01

    Extremely expensive new telescopes involve a compromise between the extreme ambitions of the scientific community, whose support justifies the financial costs, and the need to have a telescope design which can actually be built today at appropriate cost. In this article I provide a brief history of the process which built community support in Europe for what has become the European Extremely Large Telescope project (E-ELT). I then review remaining tensions between the community science case and day-one technical performance. While the range of very strong scientific cases which support the E-ELT project will largely be delivered, and lead to a quite outstanding scientific return, there are - as always! - demands for even more impressive performance. In addition to what the E-ELT will deliver, much of the community wants high spatial resolution at wavelengths shorter than one micron. Affordable adaptive optics systems will work best, initially at somewhat longer wavelengths. Planned performance enhancement during its operational life is very desirable in the E-ELT.

  9. Large-sized condoms challenge theory that "one size fits all".

    Science.gov (United States)

    1989-04-01

    Mentor Corporation and Mayer Laboratories are 2 US condom manufacturers which recently have added large-sized condoms to their product lines in response to complaints from consumers that condoms are too small. Mentor's latex condom, "Magnum," measures 20-25% larger than the average condom. Mayer's "Maxx" condom is 2.3 inches at its widest part at the tip and 8.27 inches long, including the reservoir tip. Dr. Katherine Forrest, consultant to Mayer, suggests that one is less likely to have problems with condoms falling off than one might think. If a condom does not roll all the way down, the extra unrolled latex at the bottom of the condom provides additional support. Thus, even if the condom is a little too wide at the top, the condom will stay on the penis because of the extra support and tightness at the base of the penis. Both Maxx and Magnum are manufactured in Japan. Neither has nonoxynol-9 spermicide, but both Mentor and Mayer plan to add the spermicide to the condoms later this year. The retail cost of the Maxx condom from Mayer is $7.99 for 12; Mentor's Magnum condom costs $7.19 for 12.

  10. Wintertime connections between extreme wind patterns in Spain and large-scale geopotential height field

    Science.gov (United States)

    Pascual, A.; Martín, M. L.; Valero, F.; Luna, M. Y.; Morata, A.

    2013-03-01

    The present study is focused on the study of the variability and the most significant wind speed patterns in Spain during the winter season analyzing as well connections between the wind speed field and the geopotential height at 1000 hPa over an Atlantic area. The daily wind speed variability is investigated by means of principal components using wind speed observations. Five main modes of variation, accounting 66% of the variance of the original data, have been identified, highlighting their differences in the Spanish wind speed behavior. Connections between the wind speeds and the large-scale atmospheric field were underlined by means of composite maps. Composite maps were built up to give an averaged atmospheric circulation associated with extreme wind speed variability in Spain. Moreover, the principal component analysis was also applied to the geopotential heights, providing relationships between the large-scale atmospheric modes and the observational local wind speeds. Such relationships are shown in terms of the cumulated frequency values of wind speed associated with the extreme scores of the obtained large-scale atmospheric modes, showing those large-scale atmospheric patterns more dominant in the wind field in Spain.

  11. Cerium dioxide with large particle size prepared by continuous precipitation

    Institute of Scientific and Technical Information of China (English)

    李梅; 王觅堂; 柳召刚; 胡艳宏; 吴锦绣

    2009-01-01

    Cerium dioxide(CeO2) has attracted much attention and has wide applications such as automotive exhaust catalysts,polishing materials for optical glasses and additives for advanced glasses,as well as cosmetic materials.The particle size and its distribution are key factors to the performance of the materials in the functional applications.However,control of particle size is still a challenge in materials synthesis.Therefore,continuous precipitation of cerium oxalate(precursor of ceria) was carried out at dif...

  12. Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

    Science.gov (United States)

    Zhou, Yaping; Lau, William K M.; Liu, Chuntao

    2013-01-01

    This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

  13. Extreme Learning Machines on High Dimensional and Large Data Applications: A Survey

    Directory of Open Access Journals (Sweden)

    Jiuwen Cao

    2015-01-01

    Full Text Available Extreme learning machine (ELM has been developed for single hidden layer feedforward neural networks (SLFNs. In ELM algorithm, the connections between the input layer and the hidden neurons are randomly assigned and remain unchanged during the learning process. The output connections are then tuned via minimizing the cost function through a linear system. The computational burden of ELM has been significantly reduced as the only cost is solving a linear system. The low computational complexity attracted a great deal of attention from the research community, especially for high dimensional and large data applications. This paper provides an up-to-date survey on the recent developments of ELM and its applications in high dimensional and large data. Comprehensive reviews on image processing, video processing, medical signal processing, and other popular large data applications with ELM are presented in the paper.

  14. Coupled large-eddy simulation and morphodynamics of a large-scale river under extreme flood conditions

    Science.gov (United States)

    Khosronejad, Ali; Sotiropoulos, Fotis; Stony Brook University Team

    2016-11-01

    We present a coupled flow and morphodynamic simulations of extreme flooding in 3 km long and 300 m wide reach of the Mississippi River in Minnesota, which includes three islands and hydraulic structures. We employ the large-eddy simulation (LES) and bed-morphodynamic modules of the VFS-Geophysics model to investigate the flow and bed evolution of the river during a 500 year flood. The coupling of the two modules is carried out via a fluid-structure interaction approach using a nested domain approach to enhance the resolution of bridge scour predictions. The geometrical data of the river, islands and structures are obtained from LiDAR, sub-aqueous sonar and in-situ surveying to construct a digital map of the river bathymetry. Our simulation results for the bed evolution of the river reveal complex sediment dynamics near the hydraulic structures. The numerically captured scour depth near some of the structures reach a maximum of about 10 m. The data-driven simulation strategy we present in this work exemplifies a practical simulation-based-engineering-approach to investigate the resilience of infrastructures to extreme flood events in intricate field-scale riverine systems. This work was funded by a Grant from Minnesota Dept. of Transportation.

  15. Dolphin social intelligence: complex alliance relationships in bottlenose dolphins and a consideration of selective environments for extreme brain size evolution in mammals.

    Science.gov (United States)

    Connor, Richard C

    2007-04-29

    Bottlenose dolphins in Shark Bay, Australia, live in a large, unbounded society with a fission-fusion grouping pattern. Potential cognitive demands include the need to develop social strategies involving the recognition of a large number of individuals and their relationships with others. Patterns of alliance affiliation among males may be more complex than are currently known for any non-human, with individuals participating in 2-3 levels of shifting alliances. Males mediate alliance relationships with gentle contact behaviours such as petting, but synchrony also plays an important role in affiliative interactions. In general, selection for social intelligence in the context of shifting alliances will depend on the extent to which there are strategic options and risk. Extreme brain size evolution may have occurred more than once in the toothed whales, reaching peaks in the dolphin family and the sperm whale. All three 'peaks' of large brain size evolution in mammals (odontocetes, humans and elephants) shared a common selective environment: extreme mutual dependence based on external threats from predators or conspecific groups. In this context, social competition, and consequently selection for greater cognitive abilities and large brain size, was intense.

  16. Large-scale and spatio-temporal extreme rain events over India: a hydrometeorological study

    Science.gov (United States)

    Ranade, Ashwini; Singh, Nityanand

    2014-02-01

    Frequency, intensity, areal extent (AE) and duration of rain spells during summer monsoon exhibit large intra-seasonal and inter-annual variations. Important features of the monsoon period large-scale wet spells over India have been documented. A main monsoon wet spell (MMWS) occurs over the country from 18 June to 16 September, during which, 26.5 % of the area receives rainfall 26.3 mm/day. Detailed characteristics of the MMWS period large-scale extreme rain events (EREs) and spatio-temporal EREs (ST-EREs), each concerning rainfall intensity (RI), AE and rainwater (RW), for 1 to 25 days have been studied using 1° gridded daily rainfall (1951-2007). In EREs, `same area' (grids) is continuously wet, whereas in ST-EREs, `any area' on the mean under wet condition for specified durations is considered. For the different extremes, second-degree polynomial gave excellent fit to increase in values from distribution of annual maximum RI and RW series with increase in duration. Fluctuations of RI, AE, RW and date of occurrence (or start) of the EREs and the ST-EREs did not show any significant trend. However, fluctuations of 1° latitude-longitude grid annual and spatial maximum rainfall showed highly significant increasing trend for 1 to 5 days, and unprecedented rains on 26-27 July 2005 over Mumbai could be a realization of this trend. The Asia-India monsoon intensity significantly influences the MMWS RW.

  17. Dissecting the Genetic Basis of Extremely Large Grain Shape in Rice Cultivar ‘JZ1560'

    Institute of Scientific and Technical Information of China (English)

    Jie-Zheng Ying; Ji-Ping Gao; Jun-Xiang Shan; Mei-Zhen Zhu; Min Shi; Hong-Xuan Lin

    2012-01-01

    Rice grain shape,grain length (GL),width (GW),thickness (GT) and length-to-width ratio (LWR),are usually controlled by multiple quantitative trait locus (QTL).To elucidate the genetic basis of extremely large grain shape,QTL analysis was performed using an F2 population derived from a cross between a japonica cultivar ‘JZ1560' (extremely large grain) and a contrasting indica cultivar ‘FAZ1' (small grain).A total number of 24 QTLs were detected on seven different chromosomes.QTLs for GL,GW,GT and LWR explained 11.6%,95.62%,91.5% and 89.9% of total phenotypic variation,respectively.Many QTLs pleiotropically controlled different grain traits,contributing complex traits correlation.GW2 and qSW5/GW5,which have been cloned previously to control GW,showed similar chromosomal locations with qGW2-1/qGT2-1/qLWR2-2 and qGW5-2/qLWR5-1 and should be the right candidate genes.Plants pyramiding GW2 and qSW5/GW5 showed a significant increase in GW compared with those carrying one of the two major QTLs.Furthermore,no significant QTL interaction was observed between GW2 and qSW5/GW5.These results suggested that GW2 and qSW5/GW5 might work in independent pathways to regulate grain traits.‘JZ1560' alleles underlying all QTLs contributed an increase in GW and GT and the accumulation of additive effects generates the extremely large grain shape in ‘JZ1560'.

  18. Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster

    CERN Document Server

    van Dokkum, Pieter; Merritt, Allison; Zhang, Jielai; Geha, Marla; Conroy, Charlie

    2014-01-01

    We report the discovery of 47 low surface brightness objects in deep images of a 3 x 3 degree field centered on the Coma cluster, obtained with the Dragonfly Telephoto Array. The objects have central surface brightness mu(g,0) ranging from 24 - 26 mag/arcsec^2 and effective radii r_e = 3"-10", as measured from archival Canada France Hawaii Telescope images. From their spatial distribution we infer that most or all of the objects are galaxies in the Coma cluster. This relatively large distance is surprising as it implies that the galaxies are very large: with r_e = 1.5 - 4.6 kpc their sizes are similar to those of L* galaxies even though their median stellar mass is only ~6 x 10^7 Solar masses. The galaxies are relatively red and round, with = 0.8 and = 0.74. One of the 47 galaxies is fortuitously covered by a deep Hubble Space Telescope ACS observation. The ACS imaging shows a large spheroidal object with a central surface brightness mu(g,0) = 25.8 mag/arcsec^2, a Sersic index n=0.6, and an effective radius...

  19. Strong Gravitational Lensing by the Large R-Charged Non-Extremal Black Hole

    CERN Document Server

    Naji, J

    2016-01-01

    In this paper, gravitational lensing scenario due to the R-charged black hole of five dimensional supergravity investigated. We study the effective potential of traveling photons near the R-charged black hole and find some stable orbits for the photons. We also find that the effect of the black hole charges is increasing of the effective potential. We have shown that photons do not cross the horizon of the very large R-charged black hole. By using the numerical study we find that the black hole charges and non-extremality parameter decrease value of the deflection angle.

  20. Operational flood management under large-scale extreme conditions, using the example of the Middle Elbe

    Directory of Open Access Journals (Sweden)

    A. Kron

    2010-06-01

    Full Text Available In addition to precautionary or technical flood protection measures, short-term strategies of the operational management, i.e. the initiation and co-ordination of preventive measures during and/or before a flood event are crucially for the reduction of the flood damages. This applies especially for extreme flood events. These events are rare, but may cause a protection measure to be overtopped or even to fail and be destroyed. In such extreme cases, reliable decisions must be made and emergency measures need to be carried out to prevent even larger damages from occurring.

    Based on improved methods for meteorological and hydrological modelling a range of (physically based extreme flood scenarios can be derived from historical events by modification of air temperature and humidity, shifting of weather fields and recombination of flood relevant event characteristics. By coupling the large scale models with hydraulic and geotechnical models, the whole flood-process-chain can be analysed right down to the local scale. With the developed GIS-based tools for hydraulic modelling FlowGIS and the Dike-Information-System, (IS-dikes it is possible to quantify the endangering shortly before or even during a flood event, so the decision makers can evaluate possible options for action in operational mode.

  1. GSMT Education: Teaching about Adaptive Optics and Site Selection Using Extremely Large Telescopes

    Science.gov (United States)

    Sparks, R. T.; Pompea, S. M.

    2010-08-01

    Giant Segmented Mirror Telescopes (GSMT) represents the next generation of extremely large telescopes (ELT). Currently there are three active ELT projects, all established as international partnerships to build telescopes of greater than 20 meters aperture. Two of these have major participation by U.S. institutions: the Giant Magellan Telescope and the Thirty Meter Telescope. The ESO-ELT is under development by the European Southern Observatory and other European institutions. We have developed educational activities to accompany the design phase of these projects. The current activities focus on challenges faced in the design and site selection of a large telescope. The first module is on site selection. This online module is based on the successful Astronomy Village program model. Students evaluate several potential sites to decide where to build the GSMT. They must consider factors such as weather, light pollution, seeing, logistics, and geography. The second project has developed adaptive optics teaching units suitable for high school.

  2. Alternative design for extremely large telescopes and options to use the VATT for ELT design demonstration

    Science.gov (United States)

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2013-12-01

    A variety of optical designs for extremely large telescopes (ELTs) can be found throughout the technical literature. Most feature very fast primary mirrors of either conic or spherical figure. For those designs with conic primary mirrors, many of the optical approaches tend to be derivatives of either the aplanatic Cassegrain or Gregorian systems. The Cassegrain approach is more common as it results in a shorter optical system, but it requires a large convex aspheric secondary mirror, which is extremely difficult and expensive to test. The Gregorian approach is physically longer and suffers from greater field curvature. In some design variations, additional mirrors are added to reimage and possibly flatten a Cassegrain focus. An interesting alternative ELT design uses a small Cassegrain system to image the collimated output of a Gregorian-Mersenne concentrator. Another alternative approach, currently in favor for use on the European ELT, uses three powered mirrors and two flat mirrors to reimage a Cassegrain focus out the side similar to a Nasmyth system. A preliminary examination suggests that a small, fast primary mirror, such as that used on the VATT, might be used for a subscale prototype of current ELT optical design options.

  3. Development of an Evaluation Methodology for Loss of Large Area induced from extreme events

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sok Chul; Park, Jong Seuk; Kim, Byung Soon; Jang, Dong Ju; Lee, Seung Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    USNRC announced several regulatory requirements and guidance documents regarding the event of loss of large area including 10CFR 50.54(hh), Regulatory Guide 1.214 and SRP 19.4. In Korea, consideration of loss of large area has been limitedly taken into account for newly constructing NPPs as voluntary based. In general, it is hardly possible to find available information on methodology and key assumptions for the assessment of LOLA due to 'need to know based approach'. Urgent needs exists for developing country specific regulatory requirements, guidance and evaluation methodology by themselves with the consideration of their own geographical and nuclear safety and security environments. Currently, Korea Hydro and Nuclear Power Company (KHNP) has developed an Extended Damage Mitigation Guideline (EDMG) for APR1400 under contract with foreign consulting company. The submittal guidance NEI 06-12 related to B.5.b Phase 2 and 3 focused on unit-wise mitigation strategy instead of site level mitigation or response strategy. Phase 1 mitigating strategy and guideline for LOLA (Loss of Large Area) provides emphasis on site level arrangement including cooperative networking outside organizations and agile command and control system. Korea Institute of Nuclear Safety has carried out a pilot in-house research project to develop the methodology and guideline for evaluation of LOLA since 2014. This paper introduces the summary of major results and outcomes of the aforementioned research project. After Fukushima Dai-Ichi accident, the awareness on countering the event of loss of large area induced from extreme man-made hazards or extreme beyond design basis external event. Urgent need exists to develop regulatory guidance for coping with this undesirable situation, which has been out of consideration at existing nuclear safety regulatory framework due to the expectation of rare possibility of occurrence.

  4. HOW THE ROCKY FLATS ENVIRONMENTAL TECHNOLOGY SITE DEVELOPED A NEW WASTE PACKAGE USING A POLYUREA COATING THAT IS SAFELY AND ECONOMICALLY ELIMINATING SIZE REDUCTION OF LARGE ITEMS

    Energy Technology Data Exchange (ETDEWEB)

    Dorr, Kent A.; Hogue, Richard S.; Kimokeo, Margaret K.

    2003-02-27

    One of the major challenges involved in closing the Rocky Flats Environmental Technology Site (RFETS) is the disposal of extremely large pieces of contaminated production equipment and building debris. Past practice has been to size reduce the equipment into pieces small enough to fit into approved, standard waste containers. Size reducing this equipment is extremely expensive, and exposes workers to high-risk tasks, including significant industrial, chemical, and radiological hazards. RFETS has developed a waste package using a Polyurea coating for shipping large contaminated objects. The cost and schedule savings have been significant.

  5. Development of large and medium size biogas plants

    Energy Technology Data Exchange (ETDEWEB)

    Kejun Yang; Datong Zhang [Chengdu Biogas Research Inst. (China)

    2000-07-01

    Anaerobic wastewater treatment has expanded from a few (scraped sludge, animal manure, distillery wastewater and the wastewater from slaughter houses) to more than 200 kinds of wastewaters from several industries such as pharmacy, food, and chemicals. According to incomplete statistics, up to now more than 2,000 large and medium-scale biogas plants have been constructed. They provide biogas to 54,000 households as daily fuel. About 300 biogas power stations have been installed. (orig.)

  6. Oligomeric viral proteins: small in size, large in presence

    Science.gov (United States)

    Jayaraman, Bhargavi; Smith, Amber M.; Fernandes, Jason D.; Frankel, Alan D.

    2016-01-01

    Viruses are obligate parasites that rely heavily on host cellular processes for replication. The small number of proteins typically encoded by a virus is faced with selection pressures that lead to the evolution of distinctive structural properties, allowing each protein to maintain its function under constraints such as small genome size, high mutation rate, and rapidly changing fitness conditions. One common strategy for this evolution is to utilize small building blocks to generate protein oligomers that assemble in multiple ways, thereby diversifying protein function and regulation. In this review, we discuss specific cases that illustrate how oligomerization is used to generate a single defined functional state, to modulate activity via different oligomeric states, or to generate multiple functional forms via different oligomeric states. PMID:27685368

  7. Impacts of forced and unforced climate variability on extreme floods using a large climate ensemble

    Science.gov (United States)

    Martel, Jean-Luc; Brissette, François; Chen, Jie

    2016-04-01

    Frequency analysis has been widely used for the inference of flood magnitude and rainfall intensity required in engineering design. However, this inference is based on the concept of stationarity. How accurate is it when taking into account climate variability (i.e. both internal- and externally-forced variabilities)? Even in the absence of human-induced climate change, the short temporal horizon of the historical records renders this task extremely difficult to accomplish. To overcome this situation, large ensembles of simulations from a single climate model can be used to assess the impact of climate variability on precipitation and streamflow extremes. Thus, the objective of this project is to determine the reliability of return period estimates using the CanESM2 large ensemble. The spring flood annual maxima metric over snowmelt-dominated watersheds was selected to take into account the limits of global circulation models to properly simulate convective precipitation. The GR4J hydrological model coupled with the CemaNeige snow model was selected and calibrated using gridded observation datasets on snowmelt-dominated watersheds in Quebec, Canada. Using the hydrological model, streamflows were simulated using bias corrected precipitation and temperature data from the 50 members of CanESM2. Flood frequency analyses on the spring flood annual maxima were then computed using the Gumbel distribution with a 90% confidence interval. The 20-year return period estimates were then compared to assess the impact of natural climate variability over the 1971-2000 return period. To assess the impact of global warming, this methodology was then repeated for three time slices: reference period (1971-2000), near future (2036-2065) and far future (2071-2100). Over the reference period results indicate that the relative error between the return period estimates of two members can be up to 25%. Regarding the near future and far future periods, natural climate variability of extreme

  8. Generating extreme weather event sets from very large ensembles of regional climate models

    Science.gov (United States)

    Massey, Neil; Guillod, Benoit; Otto, Friederike; Allen, Myles; Jones, Richard; Hall, Jim

    2015-04-01

    Generating extreme weather event sets from very large ensembles of regional climate models Neil Massey, Benoit P. Guillod, Friederike E. L. Otto, Myles R. Allen, Richard Jones, Jim W. Hall Environmental Change Institute, University of Oxford, Oxford, UK Extreme events can have large impacts on societies and are therefore being increasingly studied. In particular, climate change is expected to impact the frequency and intensity of these events. However, a major limitation when investigating extreme weather events is that, by definition, only few events are present in observations. A way to overcome this issue it to use large ensembles of model simulations. Using the volunteer distributed computing (VDC) infrastructure of weather@home [1], we run a very large number (10'000s) of RCM simulations over the European domain at a resolution of 25km, with an improved land-surface scheme, nested within a free-running GCM. Using VDC allows many thousands of climate model runs to be computed. Using observations for the GCM boundary forcings we can run historical "hindcast" simulations over the past 100 to 150 years. This allows us, due to the chaotic variability of the atmosphere, to ascertain how likely an extreme event was, given the boundary forcings, and to derive synthetic event sets. The events in these sets did not actually occur in the observed record but could have occurred given the boundary forcings, with an associated probability. The event sets contain time-series of fields of meteorological variables that allow impact modellers to assess the loss the event would incur. Projections of events into the future are achieved by modelling projections of the sea-surface temperature (SST) and sea-ice boundary forcings, by combining the variability of the SST in the observed record with a range of warming signals derived from the varying responses of SSTs in the CMIP5 ensemble to elevated greenhouse gas (GHG) emissions in three RCP scenarios. Simulating the future with a

  9. Aerodynamic Limits on Large Civil Tiltrotor Sizing and Efficiency

    Science.gov (United States)

    Acree, C W., Jr.

    2014-01-01

    The NASA Large Civil Tiltrotor (2nd generation, or LCTR2) has been the reference design for avariety of NASA studies of design optimization, engine and gearbox technology, handling qualities, andother areas, with contributions from NASA Ames, Glenn and Langley Centers, plus academic and industrystudies. Ongoing work includes airfoil design, 3D blade optimization, engine technology studies, andwingrotor aerodynamic interference. The proposed paper will bring the design up to date with the latestresults of such studies, then explore the limits of what aerodynamic improvements might hope toaccomplish. The purpose is two-fold: 1) determine where future technology studies might have the greatestpayoff, and 2) establish a stronger basis of comparison for studies of other vehicle configurations andmissions.

  10. Large Scale Influences on Drought and Extreme Precipitation Events in the United States

    Science.gov (United States)

    Collow, A.; Bosilovich, M. G.; Koster, R. D.; Eichmann, A.

    2015-12-01

    Observations indicate that extreme weather events are increasing and it is likely that this trend will continue through the 21st century. However, there is uncertainty and disagreement in recent literature regarding the mechanisms by which extreme temperature and precipitation events are increasing, including the suggestion that enhanced Arctic warming has resulted in an increase in blocking events and a more meridional flow. A steady gradual increase in heavy precipitation events has been observed in the Midwestern and Northeastern United States, while the Southwestern United States, particularly California, has experienced suppressed precipitation and an increase in consecutive dry days over the past few years. The frequency, intensity, and duration of heavy precipitation events in the Midwestern United States and Northeastern United States, as well as drought in the Southwestern United States are examined using the Modern Era Retrospective Analysis for Research and Applications Version-2 (MERRA-2). Indices developed by the Expert Team on Climate Change Detection and Indices representing drought and heavy precipitation events have been calculated using the MERRA-2 dataset for the period of 1980 through 2014. Trends in these indices are analyzed and the indices are compared to large scale circulations and climate modes using a composite and statistical linkages approach. Statistically significant correlations are present in the summer months between heavy precipitation events and meridional flow despite the lack of enhanced Arctic warming, contradicting the suggested mechanisms. Weaker, though still significant, correlations are observed in the winter months when the Arctic is warming more rapidly than the Midlatitudes.

  11. Extreme ultraviolet spectroscopy and atomic models of highly charged heavy ions in the Large Helical Device

    Science.gov (United States)

    Suzuki, C.; Murakami, I.; Koike, F.; Tamura, N.; Sakaue, H. A.; Morita, S.; Goto, M.; Kato, D.; Ohashi, H.; Higashiguchi, T.; Sudo, S.; O'Sullivan, G.

    2017-01-01

    We report recent results of extreme ultraviolet (EUV) spectroscopy of highly charged heavy ions in plasmas produced in the Large Helical Device (LHD). The LHD is an ideal source of experimental databases of EUV spectra because of high brightness and low opacity, combined with the availability of pellet injection systems and reliable diagnostic tools. The measured heavy elements include tungsten, tin, lanthanides and bismuth, which are motivated by ITER as well as a variety of plasma applications such as EUV lithography and biological microscopy. The observed spectral features drastically change between quasicontinuum and discrete depending on the plasma temperature, which leads to some new experimental identifications of spectral lines. We have developed collisional-radiative models for some of these ions based on the measurements. The atomic number dependence of the spectral feature is also discussed.

  12. High Precision Astrometry with MICADO at the European Extremely Large Telescope

    CERN Document Server

    Trippe, S; Eisenhauer, F; Förster-Schreiber, N M; Fritz, T K; Genzel, R

    2009-01-01

    In this article we identify and discuss various statistical and systematic effects influencing the astrometric accuracy achievable with MICADO, the near-infrared imaging camera proposed for the 42-metre European Extremely Large Telescope (E-ELT). These effects are instrumental (e.g. geometric distortion), atmospheric (e.g. chromatic differential refraction), and astronomical (reference source selection). We find that there are several phenomena having impact on ~100 micro-arcsec scales, meaning they can be substantially larger than the theoretical statistical astrometric accuracy of an optical/NIR 42m-telescope. Depending on type, these effects need to be controlled via dedicated instrumental design properties or via dedicated calibration procedures. We conclude that if this is done properly, astrometric accuracies of 40 micro-arcsec or better - with 40 micro-arcsec/year in proper motions corresponding to ~20 km/s at 100 kpc distance - can be achieved in one epoch of actual observations

  13. Modeling the Effect of Climate Change on Large Fire Size, Counts, and Intensities Using the Large Fire Simulator (FSim)

    Science.gov (United States)

    Riley, K. L.; Haas, J. R.; Finney, M.; Abatzoglou, J. T.

    2013-12-01

    Changes in climate can be expected to cause changes in wildfire activity due to a combination of shifts in weather (temperature, precipitation, relative humidity, wind speed and direction) and vegetation. Changes in vegetation could include type conversions, altered forest structure, and shifts in species composition, the effects of which could be mitigated or exacerbated by management activities. Further, changes in suppression response and effectiveness may alter potential wildfire activity, as well as the consequences of wildfire. Feedbacks among these factors are extremely complex and uncertain. The ability to anticipate changes driven by fire weather (largely outside of human control) can lead to development of fire and fuel management strategies aimed at mitigating current and future risk. Therefore, in this study we focus on isolating the effects of climate-induced changes in weather on wildfire activity. Specifically, we investigated the effect of changes in weather on fire activity in the Canadian Rockies ecoregion, which encompasses Glacier National Park and several large wilderness areas to the south. To model the ignition, growth, and containment of wildfires, we used the Large Fire Simulator (FSim), which we coupled with current and projected future climatic conditions. Weather streams were based on data from 14 downscaled Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the Representative Concentration Pathways (RCP) 45 and 85 for the years 2040-2060. While all GCMs indicate increases in temperature for this area, which would be expected to exacerbate fire activity, precipitation predictions for the summer wildfire season are more variable, ranging from a decrease of approximately 50 mm to an increase of approximately 50 mm. Windspeeds are generally predicted to decrease, which would reduce rates of spread and fire intensity. The net effect of these weather changes on the size, number, and intensity

  14. Experimental study of an optimised Pyramid wave-front sensor for Extremely Large Telescopes

    Science.gov (United States)

    Bond, Charlotte Z.; El Hadi, Kacem; Sauvage, Jean-François; Correia, Carlos; Fauvarque, Olivier; Rabaud, Didier; Lamb, Masen; Neichel, Benoit; Fusco, Thierry

    2016-07-01

    Over the last few years the Laboratoire d'Astrophysique de Marseille (LAM) has been heavily involved in R&D for adaptive optics systems dedicated to future large telescopes, particularly in preparation for the European Extremely Large Telescope (E-ELT). Within this framework an investigation into a Pyramid wave-front sensor is underway. The Pyramid sensor is at the cutting edge of high order, high precision wave-front sensing for ground based telescopes. Investigations have demonstrated the ability to achieve a greater sensitivity than the standard Shack-Hartmann wave-front sensor whilst the implementation of a Pyramid sensor on the Large Binocular Telescope (LBT) has provided compelling operational results.1, 2 The Pyramid now forms part of the baseline for several next generation Extremely Large Telescopes (ELTs). As such its behaviour under realistic operating conditions must be further understood in order to optimise performance. At LAM a detailed investigation into the performance of the Pyramid aims to fully characterise the behaviour of this wave-front sensor in terms of linearity, sensitivity and operation. We have implemented a Pyramid sensor using a high speed OCAM2 camera (with close to 0 readout noise and a frame rate of 1.5kHz) in order to study the performance of the Pyramid within a full closed loop adaptive optics system. This investigation involves tests on all fronts, from theoretical models and numerical simulations to experimental tests under controlled laboratory conditions, with an aim to fully understand the Pyramid sensor in both modulated and non-modulated configurations. We include results demonstrating the linearity of the Pyramid signals, compare measured interaction matrices with those derived in simulation and evaluate the performance in closed loop operation. The final goal is to provide an on sky comparison between the Pyramid and a Shack-Hartmann wave-front sensor, at Observatoire de la Côte d'Azur (ONERA-ODISSEE bench). Here we

  15. Extreme-ultraviolet collector mirror measurement using large reflectometer at NewSUBARU synchrotron facility

    Science.gov (United States)

    Iguchi, Haruki; Hashimoto, Hiraku; Kuki, Masaki; Harada, Tetsuo; Kinoshita, Hiroo; Watanabe, Takeo; Platonov, Yuriy Y.; Kriese, Michael D.; Rodriguez, Jim R.

    2016-06-01

    In extreme-ultraviolet (EUV) lithography, the development of high-power EUV sources is one of the critical issues. The EUV output power directly depends on the collector mirror performance. Furthermore, mirrors with large diameters are necessary to achieve high collecting performance and take sufficient distance to prevent heat and debris from a radiation point of the source. Thus collector mirror development with accurate reflectometer is important. We have developed a large reflectometer at BL-10 beamline of the NewSUBARU synchrotron facility that can be used for mirrors with diameters, thicknesses, and weights of up to 800 mm, 250 mm, and 50 kg, respectively. This reflectometer can measure reflectivity with fully s-polarized EUV light. In this study, we measured the reflectance of a 412-mm-diameter EUV collector mirror using a maximum incident angle of 36°. We obtained the peak reflectance, center wavelength and reflection bandwidth results and compared our results with Physikalisch-Technische Bundesanstalt results.

  16. A Fast SVD-Hidden-nodes based Extreme Learning Machine for Large-Scale Data Analytics.

    Science.gov (United States)

    Deng, Wan-Yu; Bai, Zuo; Huang, Guang-Bin; Zheng, Qing-Hua

    2016-05-01

    Big dimensional data is a growing trend that is emerging in many real world contexts, extending from web mining, gene expression analysis, protein-protein interaction to high-frequency financial data. Nowadays, there is a growing consensus that the increasing dimensionality poses impeding effects on the performances of classifiers, which is termed as the "peaking phenomenon" in the field of machine intelligence. To address the issue, dimensionality reduction is commonly employed as a preprocessing step on the Big dimensional data before building the classifiers. In this paper, we propose an Extreme Learning Machine (ELM) approach for large-scale data analytic. In contrast to existing approaches, we embed hidden nodes that are designed using singular value decomposition (SVD) into the classical ELM. These SVD nodes in the hidden layer are shown to capture the underlying characteristics of the Big dimensional data well, exhibiting excellent generalization performances. The drawback of using SVD on the entire dataset, however, is the high computational complexity involved. To address this, a fast divide and conquer approximation scheme is introduced to maintain computational tractability on high volume data. The resultant algorithm proposed is labeled here as Fast Singular Value Decomposition-Hidden-nodes based Extreme Learning Machine or FSVD-H-ELM in short. In FSVD-H-ELM, instead of identifying the SVD hidden nodes directly from the entire dataset, SVD hidden nodes are derived from multiple random subsets of data sampled from the original dataset. Comprehensive experiments and comparisons are conducted to assess the FSVD-H-ELM against other state-of-the-art algorithms. The results obtained demonstrated the superior generalization performance and efficiency of the FSVD-H-ELM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Computer Simulation of the Process of Quenching Large-Size Parts in Water and Aqueous Solutions

    Institute of Scientific and Technical Information of China (English)

    N.I.Kobasko; W.S.Morhuniuk; V.V.Dobrivecher; A.M.Weinov

    2004-01-01

    The article presents results of the computer simulation of quenching large-size parts in water and aqueous solutions. It has been shown that the main attention should be paid to eliminating film boiling and providing uniform cooling at the surface of the part to be quenched. Simplified formulas for calculating the optimal time of cooling large-size steel parts are presented.

  18. Large area UV SiPMs with extremely low cross-talk

    Science.gov (United States)

    Dolgoshein, B.; Mirzoyan, R.; Popova, E.; Buzhan, P.; Ilyin, A.; Kaplin, V.; Stifutkin, A.; Teshima, M.; Zhukov, A.

    2012-12-01

    For about ten years the collaboration MEPhI-Max Plank Institute for Physics in Munich has been developing SiPMs for the MAGIC and EUSO astro-particle physics experiments. The aim was to develop UV sensitive sensors of very high photon detection efficiency, substantially exceeding that of the classical photo multiplier tubes. For very high photo detection efficiency one needs to operate SiPM under the highest Geiger efficiency, i.e., to apply a high over-voltage. This means operating SiPM under high gain that in its turn produces a very high cross-talk. For suppressing the latter adverse effect we used isolating trenches and a second p-n junction, but also special implantation profiles and layers. We produced UV sensitive SiPMs of sizes 1 mm×1 mm and 3 mm×3 mm showing a peak Photon Detection Efficiency in the range of 50-60% at a cross-talk level of only 3-5%. One of the outstanding features of the new SiPM is their extremely low sensitivity of gain to temperature variations, amounting to 0.5%/°C. Below we report on new SiPMs.

  19. The role of Natural Flood Management in managing floods in large scale basins during extreme events

    Science.gov (United States)

    Quinn, Paul; Owen, Gareth; ODonnell, Greg; Nicholson, Alex; Hetherington, David

    2016-04-01

    There is a strong evidence database showing the negative impacts of land use intensification and soil degradation in NW European river basins on hydrological response and to flood impact downstream. However, the ability to target zones of high runoff production and the extent to which we can manage flood risk using nature-based flood management solution are less known. A move to planting more trees and having less intense farmed landscapes is part of natural flood management (NFM) solutions and these methods suggest that flood risk can be managed in alternative and more holistic ways. So what local NFM management methods should be used, where in large scale basin should they be deployed and how does flow is propagate to any point downstream? Generally, how much intervention is needed and will it compromise food production systems? If we are observing record levels of rainfall and flow, for example during Storm Desmond in Dec 2015 in the North West of England, what other flood management options are really needed to complement our traditional defences in large basins for the future? In this paper we will show examples of NFM interventions in the UK that have impacted at local scale sites. We will demonstrate the impact of interventions at local, sub-catchment (meso-scale) and finally at the large scale. These tools include observations, process based models and more generalised Flood Impact Models. Issues of synchronisation and the design level of protection will be debated. By reworking observed rainfall and discharge (runoff) for observed extreme events in the River Eden and River Tyne, during Storm Desmond, we will show how much flood protection is needed in large scale basins. The research will thus pose a number of key questions as to how floods may have to be managed in large scale basins in the future. We will seek to support a method of catchment systems engineering that holds water back across the whole landscape as a major opportunity to management water

  20. Head shape evolution in monitor lizards (Varanus): interactions between extreme size disparity, phylogeny and ecology.

    Science.gov (United States)

    Openshaw, G H; Keogh, J S

    2014-02-01

    Characterizing patterns of observed current variation, and testing hypotheses concerning the potential drivers of this variation, is fundamental to understanding how morphology evolves. Phylogenetic history, size and ecology are all central components driving the evolution of morphological variation, but only recently have methods become available to tease these aspects apart for particular body structures. Extant monitor lizards (Varanus) have radiated into an incredible range of habitats and display the largest body size range of any terrestrial vertebrate genus. Although their body morphology remains remarkably conservative, they have obvious head shape variation. We use two-dimensional geometric morphometric techniques to characterize the patterns of dorsal head shape variation in 36 species (375 specimens) of varanid, and test how this variation relates to size, phylogenetic history and ecology as represented by habitat. Interspecific head shape disparity is strongly allometric. Once size effects are removed, principal component analysis shows that most shape variation relates to changes in the snout and head width. Size-corrected head shape variation has strong phylogenetic signal at a broad level, but habitat use is predictive of shape disparity within phylogenetic lineages. Size often explains shape disparity among organisms; however, the ability to separate size and shape variation using geometric morphometrics has enabled the identification of phylogenetic history and habitat as additional key factors contributing to the evolution of head shape disparity among varanid lizards.

  1. Forcings and Feedbacks on Convection in the 2010 Pakistan Flood: Modeling Extreme Precipitation with Interactive Large-Scale Ascent

    CERN Document Server

    Nie, Ji; Sobel, Adam H

    2016-01-01

    Extratropical extreme precipitation events are usually associated with large-scale flow disturbances, strong ascent and large latent heat release. The causal relationships between these factors are often not obvious, however, and the roles of different physical processes in producing the extreme precipitation event can be difficult to disentangle. Here, we examine the large-scale forcings and convective heating feedback in the precipitation events which caused the 2010 Pakistan flood within the Column Quasi-Geostrophic framework. A cloud-revolving model (CRM) is forced with the large-scale forcings (other than large-scale vertical motion) computed from the quasi-geostrophic omega equation with input data from a reanalysis data set, and the large-scale vertical motion is diagnosed interactively with the simulated convection. Numerical results show that the positive feedback of convective heating to large-scale dynamics is essential in amplifying the precipitation intensity to the observed values. Orographic li...

  2. Experimental investigation and numerical simulation of large-sized aluminum tube extrusion forming

    Institute of Scientific and Technical Information of China (English)

    吕亚臣; 骆俊廷; 马春荣; 徐岩

    2008-01-01

    Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variation and velocity effect is difficult to control. The extrusion forming of large-sized aluminum tube was researched and simulated. Three-dimensional thermo-mechanical coupled finite element model was constructed and appropriate boundary conditions were given out. The results show that large-sized aluminum tube can be formed by isothermal extrusion through controlling the extrusion velocity and founding the relationship between extrusion velocity and extrusion temperature.

  3. APERTURE: a precise extremely large reflective telescope using re-configurable elements

    Science.gov (United States)

    Ulmer, M. P.; Coverstone, V. L.; Cao, J.; Chung, Y.-W.; Corbineau, M.-C.; Case, A.; Murchison, B.; Lorenz, C.; Luo, G.; Pekosh, J.; Sepulveda, J.; Schneider, A.; Yan, X.; Ye, S.

    2016-07-01

    One of the pressing needs for the UV-Vis is a design to allow even larger mirrors than the JWST primary at an affordable cost. We report here the results of a NASA Innovative Advanced Concepts phase 1 study. Our project is called A Precise Extremely large Reflective Telescope Using Reconfigurable Elements (APERTURE). The idea is to deploy a continuous membrane-like mirror. The mirror figure will be corrected after deployment to bring it into better or equal lambda/20 deviations from the prescribed mirror shape. The basic concept is not new. What is new is to use a different approach from the classical piezoelectric-patch technology. Instead, our concept is based on a contiguous coating of a so called magnetic smart material (MSM). After deployment a magnetic write head will move on the non-reflecting side of the mirror and will generate a magnetic field that will produce a stress in the MSM that will correct the mirror deviations from the prescribed shape.

  4. An Efficient Pipeline Wavefront Phase Recovery for the CAFADIS Camera for Extremely Large Telescopes

    Directory of Open Access Journals (Sweden)

    Eduardo Magdaleno

    2009-12-01

    Full Text Available In this paper we show a fast, specialized hardware implementation of the wavefront phase recovery algorithm using the CAFADIS camera. The CAFADIS camera is a new plenoptic sensor patented by the Universidad de La Laguna (Canary Islands, Spain: international patent PCT/ES2007/000046 (WIPO publication number WO/2007/082975. It can simultaneously measure the wavefront phase and the distance to the light source in a real-time process. The pipeline algorithm is implemented using Field Programmable Gate Arrays (FPGA. These devices present architecture capable of handling the sensor output stream using a massively parallel approach and they are efficient enough to resolve several Adaptive Optics (AO problems in Extremely Large Telescopes (ELTs in terms of processing time requirements. The FPGA implementation of the wavefront phase recovery algorithm using the CAFADIS camera is based on the very fast computation of two dimensional fast Fourier Transforms (FFTs. Thus we have carried out a comparison between our very novel FPGA 2D-FFTa and other implementations.

  5. Modified and double-clad large mode-area leakage channel fibers for extreme temperature conditions

    Science.gov (United States)

    Thavasi Raja, G.; Varshney, Shailendra K.

    2015-03-01

    Recently large-mode-area hybrid leakage channel fibers (HLCFs) were reported to overcome the limitation on mode area with single-mode (SM) operation for the practical bending radius of 7.5 cm at the preferred wavelength of 1064 nm. In this paper, we present the effects of a thermally induced refractive index change on the mode area of bend-compensated extremely LMA modified HLCFs (M-HLCFs) and double-clad M-HLCFs. A full-vectorial finite-element method-based modal solver is used to obtain the modal characteristics of M-HLCFs in various heat load conditions. Numerical simulations reveal that the effective mode area of M-HLCFs is ˜1433 μm2 at room temperature, which marginally decreases to ˜1387 μm2 while SM operation is maintained when the temperature distribution rises to ˜125 °C over the fiber geometry during high-power operations. We have also investigated a double-clad M-HLCF design exhibiting a mode area > ˜ 1000 μm2 for all heat load density variations up to a maximum of 12 × 109 W m-3, corresponding to a 250 °C temperature in the center of the fiber core region.

  6. Monte Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope

    Science.gov (United States)

    Basden, A. G.; Morris, T. J.

    2016-12-01

    The performance of a wide-field adaptive optics (AO) system depends on input design parameters. Here we investigate the performance of a multi-object AO system design for the European Extremely Large Telescope, using an end-to-end Monte Carlo AO simulation tool, Durham adaptive optics simulation platform, with relevance for proposed instruments such as MOSAIC. We consider parameters such as the number of laser guide stars, sodium layer depth, wavefront sensor pixel scale, actuator pitch and natural guide star availability. We provide potential areas where costs savings can be made, and investigate trade-offs between performance and cost, and provide solutions that would enable such an instrument to be built with currently available technology. Our key recommendations include a trade-off for laser guide star wavefront sensor pixel scale of about 0.7 arcsec per pixel, and a field of view of at least 7 arcsec, that electron multiplying CCD technology should be used for natural guide star wavefront sensors even if reduced frame rate is necessary, and that sky coverage can be improved by a slight reduction in natural guide star sub-aperture count without significantly affecting tomographic performance. We find that AO correction can be maintained across a wide field of view, up to 7 arcmin in diameter. We also recommend the use of at least four laser guide stars, and include ground-layer and multi-object AO performance estimates.

  7. Resistivity plateau and extremely large magnetoresistance in NbAs2 and TaAs2

    Science.gov (United States)

    Wang, Yi-Yan; Yu, Qiao-He; Guo, Peng-Jie; Liu, Kai; Xia, Tian-Long

    2016-07-01

    In topological insulators (TIs), metallic surface conductance saturates the insulating bulk resistance with decreasing temperature, resulting in resistivity plateau at low temperatures as a transport signature originating from metallic surface modes protected by time reversal symmetry (TRS). Such a characteristic has been found in several materials including Bi2Te2Se , SmB6 etc. Recently, similar behavior has been observed in metallic compound LaSb, accompanying an extremely large magnetoresistance (XMR). Shubnikov-de Hass (SdH) oscillation at low temperatures further confirms the metallic behavior of the plateau region under magnetic fields. LaSb [Tafti et al., Nat. Phys. 12, 272 (2015), 10.1038/nphys3581] has been proposed by the authors as a possible topological semimetal (TSM), while negative magnetoresistance is absent at this moment. Here, high quality single crystals of NbAs2/TaAs2 with inversion symmetry have been grown, and the resistivity under magnetic field is systematically investigated. Both of them exhibit metallic behavior under zero magnetic field, and a metal-to-insulator transition occurs when a nonzero magnetic field is applied, resulting in XMR (1.0 ×105% for NbAs2 and 7.3 ×105% for TaAs2 at 2.5 K and 14 T). With temperature decreased, a resistivity plateau emerges after the insulatorlike regime, and SdH oscillation has also been observed in NbAs2 and TaAs2.

  8. European Extremely Large Telescope Site Characterization II: High angular resolution parameters

    CERN Document Server

    Ramió, Héctor Vázquez; Muñoz-Tuñón, Casiana; Sarazin, Marc; Varela, Antonia M; Trinquet, Hervé; Delgado, José Miguel; Fuensalida, Jesús J; Reyes, Marcos; Benhida, Abdelmajid; Benkhaldoun, Zouhair; Lambas, Diego García; Hach, Youssef; Lazrek, M; Lombardi, Gianluca; Navarrete, Julio; Recabarren, Pablo; Renzi, Victor; Sabil, Mohammed; Vrech, Rubén

    2012-01-01

    This is the second article of a series devoted to European Extremely Large Telescope (E-ELT) site characterization. In this article we present the main properties of the parameters involved in high angular resolution observations from the data collected in the site testing campaign of the E-ELT during the Design Study (DS) phase. Observations were made in 2008 and 2009, in the four sites selected to shelter the future E-ELT (characterized under the ELT-DS contract): Aklim mountain in Morocco, Observatorio del Roque de los Muchachos (ORM) in Spain, Mac\\'on range in Argentina, and Cerro Ventarrones in Chile. The same techniques, instruments and acquisition procedures were taken on each site. A Multiple Aperture Scintillation Sensor (MASS) and a Differential Image Motion Monitor (DIMM) were installed at each site. Global statistics of the integrated seeing, the free atmosphere seeing, the boundary layer seeing and the isoplanatic angle were studied for each site, and the results are presented here. In order to e...

  9. European Extremely Large Telescope Site Characterization. II. High Angular Resolution Parameters

    Science.gov (United States)

    Vázquez Ramió, Héctor; Vernin, Jean; Muñoz-Tuñón, Casiana; Sarazin, Marc; Varela, Antonia M.; Trinquet, Hervé; Delgado, José Miguel; Fuensalida, Jesús J.; Reyes, Marcos; Benhida, Abdelmajid; Benkhaldoun, Zouhair; García Lambas, Diego; Hach, Youssef; Lazrek, M.; Lombardi, Gianluca; Navarrete, Julio; Recabarren, Pablo; Renzi, Victor; Sabil, Mohammed; Vrech, Rubén

    2012-08-01

    This is the second article of a series devoted to European Extremely Large Telescope (E-ELT) site characterization. In this article we present the main properties of the parameters involved in high angular resolution observations from the data collected in the site testing campaign of the E-ELT during the design study (DS) phase. Observations were made in 2008 and 2009, in the four sites selected to shelter the future E-ELT (characterized under the ELT-DS contract): Aklim mountain in Morocco, Observatorio del Roque de los Muchachos (ORM) in Spain, Macón range in Argentina, and Cerro Ventarrones in Chile. The same techniques, instruments, and acquisition procedures were taken on each site. A multiple aperture scintillation sensor (MASS) and a differential image motion monitor (DIMM) were installed at each site. Global statistics of the integrated seeing, the free atmosphere seeing, the boundary layer seeing, and the isoplanatic angle were studied for each site, and the results are presented here. In order to estimate other important parameters, such as the coherence time of the wavefront and the overall parameter “coherence étendue,” additional information of vertical profiles of the wind speed was needed. Data were retrieved from the National Oceanic and Atmospheric Administration (NOAA) archive. Ground wind speed was measured by automatic weather stations (AWS). More aspects of the turbulence parameters, such as their seasonal trend, their nightly evolution, and their temporal stability, were also obtained and analyzed.

  10. Tomographic control for wide field AO systems on extremely large telescopes

    Science.gov (United States)

    Petit, C.; Conan, J.-M.; Fusco, T.; Neichel, B.

    2010-07-01

    We investigate in this article tomographic control using both Laser and Natural Guide Stars (LGS and NGS) in the particular framework of the European Extremely Large Telescope (E-ELT) Wide Field Adaptive Optics (WFAO) modules design. A similar global control strategy has been indeed derived for both the Laser Tomographic Adaptive Optics (LTAO) and Multi-Conjugate Adaptive Optics (MCAO) modules of the E-ELT, due to similar constraints. This control strategy leads in both cases to a split control of low order modes measured thanks to NGS and high order modes measured thanks to LGS. We investigate here this split tomographic control, compared to an optimal coupled solution. To support our analysis, a dedicated simulation code has been developed. Indeed, due to the huge complexity of the EELT, fast simulation tools must be considered to explore quickly the tomographic issues. We describe our control strategy which has lead to considering split tomographic control. First results on Tomography for E-ELT WFAO systems are then presented and discussed.

  11. Double stage Lyot coronagraph with the apodized reticulated stop for extremely large telescope

    CERN Document Server

    Yaitskova, N

    2005-01-01

    One of the science drivers for the extremely large telescope (ELT) is imaging and spectroscopy of exo-solar planets located as close as 20mas to their parent star. The application requires a well thought-out design of the high contrast imaging instrumentation. Several working coronagraphic concepts have already been developed for the monolithic telescope with the diameter up to 8 meter. Nevertheless the conclusions made about the performance of these systems cannot be applied directly to the telescope of the diameter 30-100m. The existing schemes are needed to be reconsidered taking into account the specific characteristics of a segmented surface. We start this work with the classical system ? Lyot coronagraph. We show that while the increase in telescope diameter is an advantage for the high contrast range science, the segmentation sets a limit on the performance of the coronagraph. Diffraction from intersegment gaps sets a floor to the achievable extinction of the starlight. Masking out the bright segment g...

  12. Towards Precision Photometry with Extremely Large Telescopes: the Double Subgiant Branch of NGC 1851

    CERN Document Server

    Turri, P; Stetson, P B; Fiorentino, G; Andersen, D R; Véran, J -P; Bono, G

    2015-01-01

    The Extremely Large Telescopes currently under construction have a collecting area that is an order of magnitude larger than the present largest optical telescopes. For seeing-limited observations the performance will scale as the collecting area but, with the successful use of adaptive optics, for many applications it will scale as $D^4$ (where $D$ is the diameter of the primary mirror). Central to the success of the ELTs, therefore, is the successful use of multi-conjugate adaptive optics (MCAO) that applies a high degree correction over a field of view larger than the few arcseconds that limits classical adaptive optics systems. In this letter, we report on the analysis of crowded field images taken on the central region of the Galactic globular cluster NGC 1851 in $K_s$ band using GeMS at the Gemini South telescope, the only science-grade MCAO system in operation. We use this cluster as a benchmark to verify the ability to achieve precise near-infrared photometry by presenting the deepest $K_s$ photometry...

  13. Use of large bulls to improve the body weight of local small sized buffalo

    Directory of Open Access Journals (Sweden)

    M. Van Sanh

    2010-02-01

    Full Text Available Eight Swamp buffalo bulls (4 large and 4 local small sized and 240 buffalo cows (120 selected and 120 non-selected were used to evaluate the effects of bull size and selected cows on body weight of calves. Experimental animals were allocated into 4 groups: T1- large sized bulls x selected cows (BSB+SC; T2 - large sized bulls x non-selected cows (BSB+NSC; T3 – local small sized bulls x selected cows (SSB+SC and CT – local small sized bulls x non-selected cows (SSB+NSC as a control group. Each bull was mated with 15 selected cows and 15 non-selected cows. Body weight of calves at birth, 3, 6, 12 and 24 months of ages was highest in calves of T1, then T2 and then T3 while the lowest weight was found in the CT group. Calf weight in the large sized bulls and selected cows group was higher by 10-15% than that of calves in the local small bulls and non-selected cows group at all ages. It is concluded that the use of large sized bulls for breeding increased body weight of calves. Using large bulls and selected buffalo cows was the best solution for improving the body weight of the local buffalo.

  14. MRI findings of the wrist in patients with multiple osteonecrosis in large joints of the extremities

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Shinobu; Ebata, Tatsuki; Abe, Kazuhiro [Chiba Univ. (Japan). School of Medicine; Imai, Katsumi; Rokkaku, Tomoyuki

    1998-02-01

    We evaluated MRI findings of the wrist in patients who had multiple osteonecrosis in the large joints of their extremities (hips, knees, shoulders, and ankles) and compared these with the clinical symptoms and radiographical findings. Sixty wrists of 30 patients (3 males and 27 females) with multiple osteonecrosis were studied. Subjects ranged in age from 16 to 59 years. Their primary diseases were SLE in 24 patients, alcoholic osteonecrosis in two, Sjoegren`s syndrome in one, dermatomyositis in one, leukemia in one, and MCTD in one patient. Using MRI, we found osteonecrosis in seven wrists of four patients. Lesions were seen in six scaphoids of three patients, in two lunates of two patients, and in one capitate. We noted a reduced range of motion in three of the seven wrists with osteonecrosis. Two of the seven complained at wrist pain at motion, although three wrists were symptom free. Radiographically, an abnormality was recognized in two of the seven wrists. Generally, osteonecrosis of the lunate (Kienboeck`s disease) is more frequent than that of the scaphoid (Preiser`s disease). However in the present series, we found a higher osteonecrosis rate of the scaphoid than the lunate, using MRI. The discrepancy can be explained by the vascularity. In 1986, Gelberman reported that the scaphoid, the capitate, and 8% of the lunate had either vessels entering only one surface or large areas of bone that were dependent on a single vessel. The present study is consistent with these anatomical features. In other words, the present results demonstrated that Kienboeck`s disease can be induced not only by a deficient blood supply but also by some additional factors. (author)

  15. Flow adjustment inside large finite-size wind farms approaching the infinite wind farm regime

    Science.gov (United States)

    Wu, Ka Ling; Porté-Agel, Fernando

    2017-04-01

    Due to the increasing number and the growing size of wind farms, the distance among them continues to decrease. Thus, it is necessary to understand how these large finite-size wind farms and their wakes could interfere the atmospheric boundary layer (ABL) dynamics and adjacent wind farms. Fully-developed flow inside wind farms has been extensively studied through numerical simulations of infinite wind farms. The transportation of momentum and energy is only vertical and the advection of them is neglected in these infinite wind farms. However, less attention has been paid to examine the length of wind farms required to reach such asymptotic regime and the ABL dynamics in the leading and trailing edges of the large finite-size wind farms. Large eddy simulations are performed in this study to investigate the flow adjustment inside large finite-size wind farms in conventionally-neutral boundary layer with the effect of Coriolis force and free-atmosphere stratification from 1 to 5 K/km. For the large finite-size wind farms considered in the present work, when the potential temperature lapse rate is 5 K/km, the wind farms exceed the height of the ABL by two orders of magnitude for the incoming flow inside the farms to approach the fully-developed regime. An entrance fetch of approximately 40 times of the ABL height is also required for such flow adjustment. At the fully-developed flow regime of the large finite-size wind farms, the flow characteristics match those of infinite wind farms even though they have different adjustment length scales. The role of advection at the entrance and exit regions of the large finite-size wind farms is also examined. The interaction between the internal boundary layer developed above the large finite-size wind farms and the ABL under different potential temperature lapse rates are compared. It is shown that the potential temperature lapse rate plays a role in whether the flow inside the large finite-size wind farms adjusts to the fully

  16. Community Structure in Large Networks: Natural Cluster Sizes and the Absence of Large Well-Defined Clusters

    CERN Document Server

    Leskovec, Jure; Dasgupta, Anirban; Mahoney, Michael W

    2008-01-01

    A large body of work has been devoted to defining and identifying clusters or communities in social and information networks. We explore from a novel perspective several questions related to identifying meaningful communities in large social and information networks, and we come to several striking conclusions. We employ approximation algorithms for the graph partitioning problem to characterize as a function of size the statistical and structural properties of partitions of graphs that could plausibly be interpreted as communities. In particular, we define the network community profile plot, which characterizes the "best" possible community--according to the conductance measure--over a wide range of size scales. We study over 100 large real-world social and information networks. Our results suggest a significantly more refined picture of community structure in large networks than has been appreciated previously. In particular, we observe tight communities that are barely connected to the rest of the network ...

  17. Spatial patterns of sediment dynamics within a medium-sized watershed over an extreme storm event

    Science.gov (United States)

    Gao, Peng; Zhang, Zhirou

    2016-08-01

    In this study, we quantified spatial patterns of sediment dynamics in a watershed of 311 km2 over an extreme storm event using watershed modeling and statistical analyses. First, we calibrated a watershed model, Dynamic Watershed Simulation Model (DWSM) by comparing the predicted with calculated hydrograph and sedigraph at the outlet for this event. Then we predicted values of event runoff volume (V), peak flow (Qpeak), and two types of event sediment yields for lumped morphological units that contain 42 overland elements and 21 channel segments within the study watershed. Two overland elements and the connected channel segment form a first-order subwatershed, several of which constitute a larger nested subwatershed. Next we examined (i) the relationships between these variables and area (A), precipitation (P), mean slope (S), soil erodibility factor, and percent of crop and pasture lands for all overland elements (i.e., the small spatial scale, SSS), and (ii) those between sediment yield, Qpeak, A, P, and event runoff depth (h) for the first-order and nested subwatersheds along two main creeks of the study watershed (i.e., the larger spatial scales, LSS). We found that at the SSS, sediment yield was nonlinearly well related to A and P, but not Qpeak and h; whereas at the LSS, linear relationships between sediment yield and Qpeak existed, so did the Qpeak-A, and Qpeak-P relationships. This linearity suggests the increased connectivity from the SSS to LSS, which was caused by ignorance of channel processes within overland elements. It also implies that sediment was transported at capacity during the extreme event. So controlling sediment supply from the most erodible overland elements may not efficiently reduce the downstream sediment load.

  18. How Extremely Large Telescopes (ELTs) will Acquire the First Spectra of Rocky Habitable Planets

    Science.gov (United States)

    Guyon, Olivier; Martinache, F.

    2013-01-01

    ELTs will offer angular resolution around 10mas in the near-IR and unprecedented sensitivity. While direct imaging of Earth-like exoplanets around Sun-like stars will stay out of reach of ELTs, habitable planets around nearby M-type main sequence stars can be directly imaged with a system optimized for small inner working angle high contrast imaging. For about 300 nearby M dwarfs, the angular separation at maximum elongation is at or beyond 1 lambda/D in the near-IR for an ELT. The planet to star reflected light contrast is 1e-7 to 1e-8, similar to what the upcoming generation of Extreme-AO systems will achieve on 8-m telescopes, and the potential planets are sufficiently bright for near-IR spectroscopy. We show that this scientific goal is enabled by two major technologies: (1) Newly developed high efficiency coronagraphs that are compatible with segmented/sparse ELT pupils. We will describe the PIAACMC coronagraph as an example. It can deliver full starlight rejection, 100% throughput and sub-lambda/D IWA for the E-ELT, GMT and TMT pupils (2) Wavefront sensing techniques making full use of spatial coherence across the pupil, this offering several order of magnitudes gain over conventional systems. We conclude that large ground-based telescopes will be able acquire the first high quality spectra of habitable planets orbiting M-type stars, while future space mission(s) will later target habitable planets around F-G-K type stars.

  19. Industrial Process Design for Manufacturing Inconel 718 Extremely Large Forged Rings

    Science.gov (United States)

    Ambielli, John F.

    2011-12-01

    Inconel 718 is a Ni-Fe-based superalloy that has been central to the gas turbine industry since its discovery in 1963. While much more difficult to process than carbon or stainless steels, among its superalloy peers Inconel 718 has relatively high forgeability and has been used to make discs, rings, shells, and structural components. A metal forming process design algorithm is presented to incorporate key criteria relevant to superalloy processing. This algorithm was applied to conceptual forging and heat treating extremely large rings of Inconel 718 of diameter 1956 mm (77in) and weight 3252 kg (7155 lb). A 3-stage standard thermomechanical (TMP) processing was used, where Stage 1 strain varied from 0.1190 to 0.2941, Stage 2 from 0.0208 to 0.0357 and Stage 3 from 0.0440 to 0.0940. This was followed by heat treatment of a solution anneal (954°C/1750°F for 4 hour hold), air cool, then a double aging (718°C/1325°F for 8 hour hold; furnace cool to 621°C/1150°F 56°C/100°F per hr; 18 hour total time for both steps). Preliminary mechanical testing was performed. Average yield strength of 951 MPa/138 ksi (longitudinal) and 979 MPa/142 ksi (axial) was achieved. Tensile strengths were 1276 MPa/185 ksi (longitudinal) and 1255 MPa/182 ksi (axial). Elongations and reduction of areas attained were, respectively, 18 (long) and 25 (axial) and 28 (long) and 27 (axial).

  20. Large- and small-size advantages in sneaking behaviour in the dusky frillgoby Bathygobius fuscus

    Science.gov (United States)

    Takegaki, Takeshi; Kaneko, Takashi; Matsumoto, Yukio

    2012-04-01

    Sneaking tactic, a male alternative reproductive tactic involving sperm competition, is generally adopted by small individuals because of its inconspicuousness. However, large size has an advantage when competition occurs between sneakers for fertilization of eggs. Here, we suggest that both large- and small-size advantages of sneaker males are present within the same species. Large sneaker males of the dusky frillgoby Bathygobius fuscus showed a high success rate in intruding into spawning nests because of their advantage in competition among sneaker males in keeping a suitable position to sneak, whereas small sneakers had few chances to sneak. However, small sneaker males were able to stay in the nests longer than large sneaker males when they succeeded in sneak intrusion. This suggests the possibility of an increase in their paternity. The findings of these size-specific behavioural advantages may be important in considering the evolution of size-related reproductive traits.

  1. Design of a prototype position actuator for the primary mirror segments of the European Extremely Large Telescope

    Science.gov (United States)

    Jiménez, A.; Morante, E.; Viera, T.; Núñez, M.; Reyes, M.

    2010-07-01

    European Extremely Large Telescope (E-ELT) based in 984 primary mirror segments achieving required optical performance; they must position relatively to adjacent segments with relative nanometer accuracy. CESA designed M1 Position Actuators (PACT) to comply with demanding performance requirements of EELT. Three PACT are located under each segment controlling three out of the plane degrees of freedom (tip, tilt, piston). To achieve a high linear accuracy in long operational displacements, PACT uses two stages in series. First stage based on Voice Coil Actuator (VCA) to achieve high accuracies in very short travel ranges, while second stage based on Brushless DC Motor (BLDC) provides large stroke ranges and allows positioning the first stage closer to the demanded position. A BLDC motor is used achieving a continuous smoothly movement compared to sudden jumps of a stepper. A gear box attached to the motor allows a high reduction of power consumption and provides a great challenge for sizing. PACT space envelope was reduced by means of two flat springs fixed to VCA. Its main characteristic is a low linear axial stiffness. To achieve best performance for PACT, sensors have been included in both stages. A rotary encoder is included in BLDC stage to close position/velocity control loop. An incremental optical encoder measures PACT travel range with relative nanometer accuracy and used to close the position loop of the whole actuator movement. For this purpose, four different optical sensors with different gratings will be evaluated. Control strategy show different internal closed loops that work together to achieve required performance.

  2. Computational performance comparison of wavefront reconstruction algorithms for the European Extremely Large Telescope on multi-CPU architecture.

    Science.gov (United States)

    Feng, Lu; Fedrigo, Enrico; Béchet, Clémentine; Brunner, Elisabeth; Pirani, Werther

    2012-06-01

    The European Southern Observatory (ESO) is studying the next generation giant telescope, called the European Extremely Large Telescope (E-ELT). With a 42 m diameter primary mirror, it is a significant step from currently existing telescopes. Therefore, the E-ELT with its instruments poses new challenges in terms of cost and computational complexity for the control system, including its adaptive optics (AO). Since the conventional matrix-vector multiplication (MVM) method successfully used so far for AO wavefront reconstruction cannot be efficiently scaled to the size of the AO systems on the E-ELT, faster algorithms are needed. Among those recently developed wavefront reconstruction algorithms, three are studied in this paper from the point of view of design, implementation, and absolute speed on three multicore multi-CPU platforms. We focus on a single-conjugate AO system for the E-ELT. The algorithms are the MVM, the Fourier transform reconstructor (FTR), and the fractal iterative method (FRiM). This study enhances the scaling of these algorithms with an increasing number of CPUs involved in the computation. We discuss implementation strategies, depending on various CPU architecture constraints, and we present the first quantitative execution times so far at the E-ELT scale. MVM suffers from a large computational burden, making the current computing platform undersized to reach timings short enough for AO wavefront reconstruction. In our study, the FTR provides currently the fastest reconstruction. FRiM is a recently developed algorithm, and several strategies are investigated and presented here in order to implement it for real-time AO wavefront reconstruction, and to optimize its execution time. The difficulty to parallelize the algorithm in such architecture is enhanced. We also show that FRiM can provide interesting scalability using a sparse matrix approach.

  3. Body size and walking cadence affect lower extremity joint power in children's gait.

    Science.gov (United States)

    Shultz, Sarah P; Hills, Andrew P; Sitler, Michael R; Hillstrom, Howard J

    2010-06-01

    Obese children move less and with greater difficulty than normal-weight counterparts but expend comparable energy. Increased metabolic costs have been attributed to poor biomechanics but few studies have investigated the influence of obesity on mechanical demands of gait. This study sought to assess three-dimensional lower extremity joint powers in two walking cadences in 28 obese and normal-weight children. 3D-motion analysis was conducted for five trials of barefoot walking at self-selected and 30% greater than self-selected cadences. Mechanical power was calculated at the hip, knee, and ankle in sagittal, frontal and transverse planes. Significant group differences were seen for all power phases in the sagittal plane, hip and knee power at weight acceptance and hip power at propulsion in the frontal plane, and knee power during mid-stance in the transverse plane. After adjusting for body weight, group differences existed in hip and knee power phases at weight acceptance in sagittal and frontal planes, respectively. Differences in cadence existed for all hip joint powers in the sagittal plane and frontal plane hip power at propulsion. Frontal plane knee power at weight acceptance and sagittal plane knee power at propulsion were significantly different between cadences. Larger joint powers in obese children contribute to difficulty performing locomotor tasks, potentially decreasing motivation to exercise.

  4. Small, medium, large or supersize? The development and evaluation of interventions targeted at portion size.

    Science.gov (United States)

    Vermeer, W M; Steenhuis, I H M; Poelman, M P

    2014-07-01

    In the past decades, portion sizes of high-caloric foods and drinks have increased and can be considered an important environmental obesogenic factor. This paper describes a research project in which the feasibility and effectiveness of environmental interventions targeted at portion size was evaluated. The studies that we conducted revealed that portion size labeling, offering a larger variety of portion sizes, and proportional pricing (that is, a comparable price per unit regardless of the size) were considered feasible to implement according to both consumers and point-of-purchase representatives. Studies into the effectiveness of these interventions demonstrated that the impact of portion size labeling on the (intended) consumption of soft drinks was, at most, modest. Furthermore, the introduction of smaller portion sizes of hot meals in worksite cafeterias in addition to the existing size stimulated a moderate number of consumers to replace their large meals by a small meal. Elaborating on these findings, we advocate further research into communication and marketing strategies related to portion size interventions; the development of environmental portion size interventions as well as educational interventions that improve people's ability to deal with a 'super-sized' environment; the implementation of regulation with respect to portion size labeling, and the use of nudges to stimulate consumers to select healthier portion sizes.

  5. Production of large size single transient cavitation bubbles with tube arrest method

    Institute of Scientific and Technical Information of China (English)

    Chen Qi-Dai; Wang Long

    2004-01-01

    Large size single transient cavitation bubbles of maximum diameter up to 3 cm with sonoluminescence have been column motion is proposed. The results of numerical simulation are compared with the experimental data of the bubble size and oscillation period as the key parameters.

  6. The welfare implications of large litter size in the domestic pig I

    DEFF Research Database (Denmark)

    Rutherford, K.M.D.; Baxter, E.M.; D'Eath, R.B.

    2013-01-01

    Increasing litter size has long been a goal of pig breeders and producers, and may have implications for pig (Sus scrofa domesticus) welfare. This paper reviews the scientific evidence on biological factors affecting sow and piglet welfare in relation to large litter size. It is concluded that, i...

  7. Large-scale drivers of local precipitation extremes in convection-permitting climate simulations

    Science.gov (United States)

    Chan, Steven C.; Kendon, Elizabeth J.; Roberts, Nigel M.; Fowler, Hayley J.; Blenkinsop, Stephen

    2016-04-01

    The Met Office 1.5-km UKV convective-permitting models (CPM) is used to downscale present-climate and RCP8.5 60-km HadGEM3 GCM simulations. Extreme UK hourly precipitation intensities increase with local near-surface temperatures and humidity; for temperature, the simulated increase rate for the present-climate simulation is about 6.5% K**-1, which is consistent with observations and theoretical expectations. While extreme intensities are higher in the RCP8.5 simulation as higher temperatures are sampled, there is a decline at the highest temperatures due to circulation and relative humidity changes. Extending the analysis to the broader synoptic scale, it is found that circulation patterns, as diagnosed by MSLP or circulation type, play an increased role in the probability of extreme precipitation in the RCP8.5 simulation. Nevertheless for both CPM simulations, vertical instability is the principal driver for extreme precipitation.

  8. Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Angelo; Byrne, James V. [ohn Radcliffe Hospital, Oxford Neurovascular and Neuroradiology Research Unit, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Rane, Neil; Kueker, Wilhelm; Cellerini, Martino; Corkill, Rufus [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom)

    2014-01-15

    This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. (orig.)

  9. Science case and requirements for the MOSAIC concept for a multi-object spectrograph for the European Extremely Large Telescope

    NARCIS (Netherlands)

    Evans, C. J.; Puech, M.; Barbuy, B.; Bonifacio, P.; Cuby, J.-G.; Guenther, E.; Hammer, F.; Jagourel, P.; Kaper, L.; Morris, S. L.; Afonso, J.; Amram, P.; Aussel, H.; Basden, A.; Bastian, N.; Battaglia, G.; Biller, B.; Bouché, N.; Caffau, E.; Charlot, S.; Clénet, Y.; Combes, F.; Conselice, C.; Contini, T.; Dalton, G.; Davies, B.; Disseau, K.; Dunlop, J.; Fiore, F.; Flores, H.; Fusco, T.; Gadotti, D.; Gallazzi, A.; Giallongo, E.; Gonçalves, T.; Gratadour, D.; Hill, V.; Huertas-Company, M.; Ibata, R.; Larsen, S.; Le Fèvre, O.; Lemasle, B.; Maraston, C.; Mei, S.; Mellier, Y.; Östlin, G.; Paumard, T.; Pello, R.; Pentericci, L.; Petitjean, P.; Roth, M.; Rouan, D.; Schaerer, D.; Telles, E.; Trager, S.; Welikala, N.; Zibetti, S.; Ziegler, B.

    2014-01-01

    Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input from a broad cross-section of astronomers across the ESO partner countries

  10. Identification of genetic variants associated with maize flowering time using an extremely large multi-genetic background population

    Science.gov (United States)

    Flowering time is one of the major adaptive traits in domestication of maize and an important selection criterion in breeding. To detect more maize flowering time variants we evaluated flowering time traits using an extremely large multi- genetic background population that contained more than 8000 l...

  11. Using plate mapping to examine portion size and plate composition for large and small divided plates.

    Science.gov (United States)

    Sharp, David E; Sobal, Jeffery; Wansink, Brian

    2014-12-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods - such as meat versus vegetables - differently? To examine this question, we used the new method of plate mapping, where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, which showed that the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are that plate size may influence portion size and change the proportions of foods served.

  12. Wind and Wave Extremes over the World Oceans From Very Large Forecast Ensembles

    CERN Document Server

    Breivik, Øyvind; Abdalla, Saleh; Bidlot, Jean-Raymond

    2013-01-01

    Global return value estimates of significant wave height and 10-m neutral wind speed are estimated from very large aggregations of archived ECMWF ensemble forecasts at +240-h lead time from the period 2003-2012. The upper percentiles are found to match ENVISAT wind speed better than ERA-Interim (ERA-I), which tends to be biased low. The return estimates are significantly higher for both wind speed and wave height in the extratropics and the subtropics than what is found from ERA-I, but lower than what is reported by Caires and Sterl (2005) and Vinoth and Young (2011). The highest discrepancies between ERA-I and ENS240 are found in the hurricane-prone areas, suggesting that the ensemble comes closer than ERA-I in capturing the intensity of tropical cyclones. The width of the confidence intervals are typically reduced by 70% due to the size of the data sets. Finally, non-parametric estimates of return values were computed from the tail of the distribution. These direct return estimates compare very well with Ge...

  13. Effects of sample size on estimation of rainfall extremes at high temperatures

    Directory of Open Access Journals (Sweden)

    B. Boessenkool

    2017-09-01

    Full Text Available High precipitation quantiles tend to rise with temperature, following the so-called Clausius–Clapeyron (CC scaling. It is often reported that the CC-scaling relation breaks down and even reverts for very high temperatures. In our study, we investigate this reversal using observational climate data from 142 stations across Germany. One of the suggested meteorological explanations for the breakdown is limited moisture supply. Here we argue that, instead, it could simply originate from undersampling. As rainfall frequency generally decreases with higher temperatures, rainfall intensities as dictated by CC scaling are less likely to be recorded than for moderate temperatures. Empirical quantiles are conventionally estimated from order statistics via various forms of plotting position formulas. They have in common that their largest representable return period is given by the sample size. In small samples, high quantiles are underestimated accordingly. The small-sample effect is weaker, or disappears completely, when using parametric quantile estimates from a generalized Pareto distribution (GPD fitted with L moments. For those, we obtain quantiles of rainfall intensities that continue to rise with temperature.

  14. Paediatric extremity vascular injuries - experience from a large urban trauma centre in India.

    Science.gov (United States)

    Jaipuria, Jiten; Sagar, Sushma; Singhal, Maneesh; Bagdia, Amit; Gupta, Amit; Kumar, Subodh; Mishra, Biplab

    2014-01-01

    Paediatric extremity vascular injuries are infrequent, and management protocols draw significantly from adult vascular trauma experience necessitating a continuous review of evidence. A retrospective registry review of all consecutive patients younger than 18 years age treated for extremity vascular trauma from 2007 to 2012 was carried out. Diagnostic algorithm relied little on measurement of pressure indices. Data was collected about demographics, time since injury, pattern of injury, ISS, initial GCS and presence of shock, results of diagnostic modality and treatment given with associated complications. Patients completing 2 years follow up were assessed for functional disability and vascular patency. A multivariable regression model was used to evaluate effects of - ISS, presence of orthopaedic injury, soft tissue injury, neural injury and arterial patency at the end of 2 years - on outcome of functional disability. Paediatric extremity vascular injuries accounted for 0.68% hospital admissions with a median delay of 8h from injury. 82 patients were included with 50 cases examined for long term outcome. Patient cohort was overwhelmingly male, with 'fall', 'road traffic injury' and 'glass cut' being most common injury mechanisms. CT angiography and duplex scan based diagnostic algorithm performed satisfactorily further identifying missed injuries and aiding complex orthopaedic reconstruction. Brachial and femoral vessels were most commonly injured. Lower extremity vascular injury was found associated with significantly higher ISS and requirement for fasciotomy. Upper extremity vascular injury was associated with higher odds of neural injury. Younger children were at higher risk of combined radial and ulnar vessel injury. No patient satisfactorily complied with post-operative anticoagulant/antithrombotic prophylaxis. 28 patients had good functional outcome with unsatisfactory functional outcome found associated with significantly higher ISS, presence of orthopaedic

  15. Large wood recruitment processes and transported volumes in Swiss mountain streams during the extreme flood of August 2005

    Science.gov (United States)

    Steeb, Nicolas; Rickenmann, Dieter; Badoux, Alexandre; Rickli, Christian; Waldner, Peter

    2017-02-01

    The extreme flood event that occurred in August 2005 was the most costly (documented) natural hazard event in the history of Switzerland. The flood was accompanied by the mobilization of > 69,000 m3 of large wood (LW) throughout the affected area. As recognized afterward, wood played an important role in exacerbating the damages, mainly because of log jams at bridges and weirs. The present study aimed at assessing the risk posed by wood in various catchments by investigating the amount and spatial variability of recruited and transported LW. Data regarding LW quantities were obtained by field surveys, remote sensing techniques (LiDAR), and GIS analysis and was subsequently translated into a conceptual model of wood transport mass balance. Detailed wood budgets and transport diagrams were established for four study catchments of Swiss mountain streams, showing the spatial variability of LW recruitment and deposition. Despite some uncertainties with regard to parameter assumptions, the sum of reconstructed wood input and observed deposition volumes agree reasonably well. Mass wasting such as landslides and debris flows were the dominant recruitment processes in headwater streams. In contrast, LW recruitment from lateral bank erosion became significant in the lower part of mountain streams where the catchment reached a size of about 100 km2. According to our analysis, 88% of the reconstructed total wood input was fresh, i.e., coming from living trees that were recruited from adjacent areas during the event. This implies an average deadwood contribution of 12%, most of which was estimated to have been in-channel deadwood entrained during the flood event.

  16. Statistical modelling of wildfire size and intensity: a step toward meteorological forecasting of summer extreme fire risk

    Science.gov (United States)

    Hernandez, C.; Keribin, C.; Drobinski, P.; Turquety, S.

    2015-12-01

    In this article we investigate the use of statistical methods for wildfire risk assessment in the Mediterranean Basin using three meteorological covariates, the 2 m temperature anomaly, the 10 m wind speed and the January-June rainfall occurrence anomaly. We focus on two remotely sensed characteristic fire variables, the burnt area (BA) and the fire radiative power (FRP), which are good proxies for fire size and intensity respectively. Using the fire data we determine an adequate parametric distribution function which fits best the logarithm of BA and FRP. We reconstruct the conditional density function of both variables with respect to the chosen meteorological covariates. These conditional density functions for the size and intensity of a single event give information on fire risk and can be used for the estimation of conditional probabilities of exceeding certain thresholds. By analysing these probabilities we find two fire risk regimes different from each other at the 90 % confidence level: a "background" summer fire risk regime and an "extreme" additional fire risk regime, which corresponds to higher probability of occurrence of larger fire size or intensity associated with specific weather conditions. Such a statistical approach may be the ground for a future fire risk alert system.

  17. Optical encryption for large-sized images using random phase-free method

    CERN Document Server

    Shimobaba, Tomoyoshi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Sugie, Takashige; Ito, Tomoyoshi

    2015-01-01

    We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.

  18. Chemical Vapor Deposition of Large-Size Monolayer MoSe2 Crystals on Molten Glass.

    Science.gov (United States)

    Chen, Jianyi; Zhao, Xiaoxu; Tan, Sherman J R; Xu, Hai; Wu, Bo; Liu, Bo; Fu, Deyi; Fu, Wei; Geng, Dechao; Liu, Yanpeng; Liu, Wei; Tang, Wei; Li, Linjun; Zhou, Wu; Sum, Tze Chien; Loh, Kian Ping

    2017-01-25

    We report the fast growth of high-quality millimeter-size monolayer MoSe2 crystals on molten glass using an ambient pressure CVD system. We found that the isotropic surface of molten glass suppresses nucleation events and greatly improves the growth of large crystalline domains. Triangular monolayer MoSe2 crystals with sizes reaching ∼2.5 mm, and with a room-temperature carrier mobility up to ∼95 cm(2)/(V·s), can be synthesized in 5 min. The method can also be used to synthesize millimeter-size monolayer MoS2 crystals. Our results demonstrate that "liquid-state" glass is a highly promising substrate for the low-cost growth of high-quality large-size 2D transition metal dichalcogenides (TMDs).

  19. Contribution of large-scale circulation anomalies to changes in extreme precipitation frequency in the United States

    Science.gov (United States)

    Yu, Lejiang; Zhong, Shiyuan; Pei, Lisi; Bian, Xindi; Heilman, Warren E.

    2016-04-01

    The mean global climate has warmed as a result of the increasing emission of greenhouse gases induced by human activities. This warming is considered the main reason for the increasing number of extreme precipitation events in the US. While much attention has been given to extreme precipitation events occurring over several days, which are usually responsible for severe flooding over a large region, little is known about how extreme precipitation events that cause flash flooding and occur at sub-daily time scales have changed over time. Here we use the observed hourly precipitation from the North American Land Data Assimilation System Phase 2 forcing datasets to determine trends in the frequency of extreme precipitation events of short (1 h, 3 h, 6 h, 12 h and 24 h) duration for the period 1979-2013. The results indicate an increasing trend in the central and eastern US. Over most of the western US, especially the Southwest and the Intermountain West, the trends are generally negative. These trends can be largely explained by the interdecadal variability of the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation (AMO), with the AMO making a greater contribution to the trends in both warm and cold seasons.

  20. A simplified experimental model of large-for-size liver transplantation in pigs

    Directory of Open Access Journals (Sweden)

    Antonio Jose Goncalves Leal

    2013-01-01

    Full Text Available OBJECTIVE: The ideal ratio between liver graft mass and recipient body weight for liver transplantation in small infants is unknown; however, if this ratio is over 4%, a condition called large-for-size may occur. Experimental models of large-for-size liver transplants have not been described in the literature. In addition, orthotopic liver transplantation is marked by high morbidity and mortality rates in animals due to the clamping of the venous splanchnic system. Therefore, the objective of this study was to create a porcine model of large-for-size liver transplantation with clamping of the supraceliac aorta during the anhepatic phase as an alternative to venovenous bypass. METHOD: Fourteen pigs underwent liver transplantation with whole-liver grafts without venovenous bypass and were divided into two experimental groups: the control group, in which the weights of the donors were similar to the weights of the recipients; and the large-for-size group, in which the weights of the donors were nearly 2 times the weights of the recipients. Hemodynamic data, the results of serum biochemical analyses and histological examination of the transplanted livers were collected. RESULTS: The mortality rate in both groups was 16.5% (1/7. The animals in the large-for-size group had increased serum levels of potassium, sodium, aspartate aminotransferase and alanine aminotransferase after graft reperfusion. The histological analyses revealed that there were no significant differences between the groups. CONCLUSION: This transplant method is a feasible experimental model of large-for-size liver transplantation.

  1. Optimum siting and sizing of a large distributed generator in a mesh connected system

    Energy Technology Data Exchange (ETDEWEB)

    Elnashar, Mohab M.; El Shatshat, Ramadan; Salama, Magdy M.A. [Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario (Canada)

    2010-06-15

    This paper proposes a new approach to optimally determine the appropriate size and location of the distributed generator (DG) in a large mesh connected system. This paper presents a visual optimization approach in which the planner plays an important role in determining the optimal siting and sizing of the DG through the choice of the appropriate weight factors of the parameters included in the optimization technique according to the system deficiencies. Losses, voltage profile and short circuit level are used in the algorithm to determine the optimum sizes and locations of the DG. The short circuit level parameter is introduced to represent the protective device requirements in the selection of the size and location of the DG. The proposed technique has been tested on the IEEE 24 - bus mesh connected test system. The obtained results showed clearly that the optimal size and location can be simply determined through the proposed approach. (author)

  2. Ultrafast laser ablation and machining large-size structures on porcine bone.

    Science.gov (United States)

    An, Ran; Khadar, Ghadeer W; Wilk, Emilia I; Emigh, Brent; Haugen, Harold K; Wohl, Gregory R; Dunlop, Brett; Anvari, Mehran; Hayward, Joseph E; Fang, Qiyin

    2013-07-01

    When using ultrafast laser ablation in some orthopedic applications where precise cutting/drilling is required with minimal damage to collateral tissue, it is challenging to produce large-sized and deep holes using a tightly focused laser beam. The feasibility of producing deep, millimeter-size structures under different ablation strategies is investigated. X-ray computed microtomography was employed to analyze the morphology of these structures. Our results demonstrated the feasibility of producing holes with sizes required in clinical applications using concentric and helical ablation protocols.

  3. Corporate Social Responsibility in Large and Medium-sized Companies in Poland

    Directory of Open Access Journals (Sweden)

    Maja Żychlewicz

    2016-06-01

    Full Text Available The paper aims to confront views on the CSR concept with the actual activities undertaken in this area by the large and medium-sized companies in Poland. The paper is enriched by the presentation of consumer opinions on CSR, by which it is possible to identify the purpose of implementing socially responsible activities in these entities. The thesis of the paper is that large and medium-sized enterprises in Poland recognize the expectations of consumers in the implementation of the concept of corporate social responsibility and at the same time feel the same need, but many of them have not taken any action in this respect so far.

  4. Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation

    Science.gov (United States)

    Leal, Antonio José Gonçalves; Tannuri, Ana Cristina Aoun; Belon, Alessandro Rodrigo; Guimarães, Raimundo Renato Nunes; Coelho, Maria Cecília Mendonça; de Oliveira Gonçalves, Josiane; Serafini, Suellen; de Melo, Evandro Sobroza; Tannuri, Uenis

    2015-01-01

    OBJECTIVE: In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity. METHODS: Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax (pro-apoptotic), Bcl-XL (anti-apoptotic), c-Fos and c-Jun (immediate-early genes), ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration), intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning) and TGF-beta (a pro-fibrogenic cytokine). RESULTS: All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression. CONCLUSION

  5. Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation

    Directory of Open Access Journals (Sweden)

    Antonio José Gonçalves Leal

    2015-02-01

    Full Text Available OBJECTIVE: In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity. METHODS: Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax (pro-apoptotic, Bcl-XL (anti-apoptotic, c-Fos and c-Jun (immediate-early genes, ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration, intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning and TGF-beta (a pro-fibrogenic cytokine. RESULTS: All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression

  6. Embrittlement and decrease of apparent strength in large-sized concrete structures

    Indian Academy of Sciences (India)

    Alberto Carpinteri; Bernardino Chiaia

    2002-08-01

    The problem of scale-effects on the performances of concrete structures is discussed. Experimentally observed decrease of nominal tensile strength, accompanied by structural embrittlement, occurring in large structures is of crucial importance in modern concrete engineering. Most of the previous approaches to the problem are restricted to notched structures and they often fail to predict mechanical behaviour in real situations. The physical approach put forward by us takes into adequate account the effects of microstructural disorder and seems to be valid in the whole size range, at least for unnotched structures. Thereby, reliable predictions can be made of the material properties in large-sized concrete structures.

  7. Forcings and feedbacks on convection in the 2010 Pakistan flood: Modeling extreme precipitation with interactive large-scale ascent

    Science.gov (United States)

    Nie, Ji; Shaevitz, Daniel A.; Sobel, Adam H.

    2016-09-01

    Extratropical extreme precipitation events are usually associated with large-scale flow disturbances, strong ascent, and large latent heat release. The causal relationships between these factors are often not obvious, however, the roles of different physical processes in producing the extreme precipitation event can be difficult to disentangle. Here we examine the large-scale forcings and convective heating feedback in the precipitation events, which caused the 2010 Pakistan flood within the Column Quasi-Geostrophic framework. A cloud-revolving model (CRM) is forced with large-scale forcings (other than large-scale vertical motion) computed from the quasi-geostrophic omega equation using input data from a reanalysis data set, and the large-scale vertical motion is diagnosed interactively with the simulated convection. Numerical results show that the positive feedback of convective heating to large-scale dynamics is essential in amplifying the precipitation intensity to the observed values. Orographic lifting is the most important dynamic forcing in both events, while differential potential vorticity advection also contributes to the triggering of the first event. Horizontal moisture advection modulates the extreme events mainly by setting the environmental humidity, which modulates the amplitude of the convection's response to the dynamic forcings. When the CRM is replaced by either a single-column model (SCM) with parameterized convection or a dry model with a reduced effective static stability, the model results show substantial discrepancies compared with reanalysis data. The reasons for these discrepancies are examined, and the implications for global models and theoretical models are discussed.

  8. Novel π-type vortex in a nanoscale extreme type-II superconductor: Induced by quantum-size effect

    Science.gov (United States)

    Huang, Haiyan; Liu, Qing; Zhang, Wenhui; Chen, Yajiang

    2016-11-01

    By numerically solving the Bogoliubov-de Gennes equations, we report a novel π-type vortex state whose order parameter near the core undergoes an extraordinary π-phase change for a quantum-confined extreme type-II s-wave superconductor. Its supercurrent behaves as the cube of the radial coordinate near the core, and its local density of states spectrum exhibits a significant negative-shifted zero-bias peak. Such π-type vortex state is induced by quantum-size effect, and can survive thermal smearing at temperatures up to a critical value Tτ. The Anderson's approximation indicates that the π-type vortex may remain stable under sufficiently week magnetic field in the case less deep in the type-II limit. Moreover, we find that its appearance is governed by the sample size and kFξ0 with kF the Fermi wave number and ξ0 the zero-temperature coherence length. Similar effects may be expected in quantum-confined ultracold superfluid Fermi gasses, or even high-Tc superconductors with proper kFξ0 value.

  9. Evaluation of large-scale meteorological patterns associated with temperature extremes in the NARCCAP regional climate model simulations

    Science.gov (United States)

    Loikith, Paul C.; Waliser, Duane E.; Lee, Huikyo; Neelin, J. David; Lintner, Benjamin R.; McGinnis, Seth; Mearns, Linda O.; Kim, Jinwon

    2015-12-01

    Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate Change Assessment Program. LSMPs are characterized through composites of surface air temperature, sea level pressure, and 500 hPa geopotential height anomalies concurrent with extreme temperature days. Six of the seventeen RCM simulations are driven by boundary conditions from reanalysis while the other eleven are driven by one of four global climate models (GCMs). Four illustrative case studies are analyzed in detail. Model fidelity in LSMP spatial representation is high for cold winter extremes near Chicago. Winter warm extremes are captured by most RCMs in northern California, with some notable exceptions. Model fidelity is lower for cool summer days near Houston and extreme summer heat events in the Ohio Valley. Physical interpretation of these patterns and identification of well-simulated cases, such as for Chicago, boosts confidence in the ability of these models to simulate days in the tails of the temperature distribution. Results appear consistent with the expectation that the ability of an RCM to reproduce a realistically shaped frequency distribution for temperature, especially at the tails, is related to its fidelity in simulating LMSPs. Each ensemble member is ranked for its ability to reproduce LSMPs associated with observed warm and cold extremes, identifying systematically high performing RCMs and the GCMs that provide superior boundary forcing. The methodology developed here provides a framework for identifying regions where further process-based evaluation would improve the understanding of simulation error and help guide future model improvement and downscaling efforts.

  10. Evolution of large body size in abalones (Haliotis): Patterns and implications

    Science.gov (United States)

    Estes, J.A.; Lindberg, D.R.; Wray, C.

    2005-01-01

    Kelps and other fleshy macroalgae - dominant reef-inhabiting organisms in cool - seasmay have radiated extensively following late Cenozoic polar cooling, thus triggering a chain of evolutionary change in the trophic ecology of nearshore temperate ecosystems. We explore this hypothesis through an analysis of body size in the abalones (Gastropoda; Haliotidae), a widely distributed group in modern oceans that displays a broad range of body sizes and contains fossil representatives from the late Cretaceous (60-75 Ma). Geographic analysis of maximum shell length in living abalones showed that small-bodied species, while most common in the Tropics, have a cosmopolitan distribution, whereas large-bodied species occur exclusively in cold-water ecosystems dominated by kelps and other macroalgae. The phylogeography of body size evolution in extant abalones was assessed by constructing a molecular phylogeny in a mix of large and small species obtained from different regions of the world. This analysis demonstrates that small body size is the plesiomorphic state and largeness has likely arisen at least twice. Finally, we compiled data on shell length from the fossil record to determine how (slowly or suddenly) and when large body size arose in the abalones. These data indicate that large body size appears suddenly at the Miocene/Pliocene boundary. Our findings support the view that fleshy-algal dominated ecosystems radiated rapidly in the coastal oceans with the onset of the most recent glacial age. We conclude with a discussion of the broader implications of this change. ?? 2005 The Paleontological Society. All rights reserved.

  11. Synapse clusters are preferentially formed by synapses with large recycling pool sizes.

    Directory of Open Access Journals (Sweden)

    Oliver Welzel

    Full Text Available Synapses are distributed heterogeneously in neural networks. The relationship between the spatial arrangement of synapses and an individual synapse's structural and functional features remains to be elucidated. Here, we examined the influence of the number of adjacent synapses on individual synaptic recycling pool sizes. When measuring the discharge of the styryl dye FM1-43 from electrically stimulated synapses in rat hippocampal tissue cultures, a strong positive correlation between the number of neighbouring synapses and recycling vesicle pool sizes was observed. Accordingly, vesicle-rich synapses were found to preferentially reside next to neighbours with large recycling pool sizes. Although these synapses with large recycling pool sizes were rare, they were densely arranged and thus exhibited a high amount of release per volume. To consolidate these findings, functional terminals were marked by live-cell antibody staining with anti-synaptotagmin-1-cypHer or overexpression of synaptopHluorin. Analysis of synapse distributions in these systems confirmed the results obtained with FM 1-43. Our findings support the idea that clustering of synapses with large recycling pool sizes is a distinct developmental feature of newly formed neural networks and may contribute to functional plasticity.

  12. Effect of large pore size of multifunctional mesoporous microsphere on removal of heavy metal ions.

    Science.gov (United States)

    Yuan, Qing; Li, Nan; Chi, Yue; Geng, Wangchang; Yan, Wenfu; Zhao, Ying; Li, Xiaotian; Dong, Bin

    2013-06-15

    Pore size of mesoporous materials is crucial for their surface grafting. This article develops a novel multifunctional microsphere with a large pore size mesoporous silica shell (ca. 10.3 nm) and a magnetic core (Fe₃O₄), which is fabricated using cetyltrimethylammonium bromide (CTAB) as pore-forming agents, tetraethyl orthosilicate (TEOS) as silicon source through a sol-gel process. Compared with small pore size mesoporous silica magnetic microspheres (ca. 2-4 nm), the large pore size one can graft 447 mg/g amino groups in order to adsorb more heavy metal ions (Pb(2+): 880.6 mg/g, Cu(2+): 628.3mg/g, Cd(2+): 492.4 mg/g). The metal-loaded multifunctional microspheres could be easily removed from aqueous solution by magnetic separation and regenerated easily by acid treatment. The results suggest that the large pore size multifunctional microspheres are potentially useful materials for high effectively adsorbing and removing different heavy metal ions in aqueous solution. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. THE QUALIMETRY OF LARGE-SIZED STAMPED-SHEET DETAILS GEOMETRY

    Directory of Open Access Journals (Sweden)

    A. Demchenko

    2009-01-01

    Full Text Available The qualimetric method of the large-sized stamped-sheet details influence of geometric shape on the manufacture performance characteristics are given. The graphic model of shape classification and geometric shape factor definition algorithms for triangular and quadrangular shapes are proposed.

  14. INSTALLATION FOR LARGE SIZE STAMP HARDENING TRANINIG BY WATER-AIR MIXTURE

    Directory of Open Access Journals (Sweden)

    L. A. Glazkov

    2009-01-01

    Full Text Available The BNTU has developed a technological process for large-size stamp hardening by means of a water-air mixture.  The  basic  requirements  imposed on an hardening  installation using  a  water-air mixture are the following: provision of smooth cooling of a part in order to achieve the required  hardness and structure; possibility of machining parts of various sizes; change of modes for machining parts of various grades of steel according to any hardness rate.The peculiar features of the given installation are: a presence of microprocessor control of water-air mixture supply, possibility of simultaneous machining of a stamp set (2 parts and position change of parts to be hardened in the process of thermal treatment.Installation for large-sized stamp hardening has been manufactured and introduced at theMinskplant of special tools and machining attachments.

  15. Large Time Asymptotics for a Continuous Coagulation-Fragmentation Model with Degenerate Size-Dependent Diffusion

    KAUST Repository

    Desvillettes, Laurent

    2010-01-01

    We study a continuous coagulation-fragmentation model with constant kernels for reacting polymers (see [M. Aizenman and T. Bak, Comm. Math. Phys., 65 (1979), pp. 203-230]). The polymers are set to diffuse within a smooth bounded one-dimensional domain with no-flux boundary conditions. In particular, we consider size-dependent diffusion coefficients, which may degenerate for small and large cluster-sizes. We prove that the entropy-entropy dissipation method applies directly in this inhomogeneous setting. We first show the necessary basic a priori estimates in dimension one, and second we show faster-than-polynomial convergence toward global equilibria for diffusion coefficients which vanish not faster than linearly for large sizes. This extends the previous results of [J.A. Carrillo, L. Desvillettes, and K. Fellner, Comm. Math. Phys., 278 (2008), pp. 433-451], which assumes that the diffusion coefficients are bounded below. © 2009 Society for Industrial and Applied Mathematics.

  16. Potential enhanced ability of giant squid to detect sperm whales is an exaptation tied to their large body size.

    Science.gov (United States)

    Schmitz, Lars; Motani, Ryosuke; Oufiero, Christopher E; Martin, Christopher H; McGee, Matthew D; Wainwright, Peter C

    2013-01-01

    It has been hypothesized that sperm whale predation is the driver of eye size evolution in giant squid. Given that the eyes of giant squid have the size expected for a squid this big, it is likely that any enhanced ability of giant squid to detect whales is an exaptation tied to their body size. Future studies should target the mechanism behind the evolution of large body size, not eye size. Reconstructions of the evolutionary history of selective regime, eye size, optical performance, and body size will improve the understanding of the evolution of large eyes in large ocean animals.

  17. Gallstone ileus of the sigmoid colon: an extremely rare cause of large bowel obstruction detected by multiplanar CT.

    Science.gov (United States)

    Carlsson, Tarryn; Gandhi, Sanjay

    2015-12-18

    Gallstone ileus of the sigmoid colon is an important, though extremely rare, cause of large bowel obstruction. The gallstone often enters the large bowel through a fistula formation between the gallbladder and colon, and impacts at a point of narrowing, causing large bowel obstruction. We describe the case of an 80-year-old woman who presented with features of bowel obstruction. Multiplanar abdominal CT demonstrated a cholecystocolonic fistula in exquisite detail. The scan also showed obstruction of the colon due to a large gallstone impacted just proximal to a stricture in the sigmoid. Owing to inflammatory adhesions and a stricture from extensive diverticular disease, the gallstone could not be retrieved. This frail and elderly woman was treated with a loop colostomy to relieve bowel obstruction. The patient made an uneventful recovery.

  18. Size Reduction Techniques for Large Scale Permanent Magnet Generators in Wind Turbines

    Science.gov (United States)

    Khazdozian, Helena; Hadimani, Ravi; Jiles, David

    2015-03-01

    Increased wind penetration is necessary to reduce U.S. dependence on fossil fuels, combat climate change and increase national energy security. The U.S Department of Energy has recommended large scale and offshore wind turbines to achieve 20% wind electricity generation by 2030. Currently, geared doubly-fed induction generators (DFIGs) are typically employed in the drivetrain for conversion of mechanical to electrical energy. Yet, gearboxes account for the greatest downtime of wind turbines, decreasing reliability and contributing to loss of profit. Direct drive permanent magnet generators (PMGs) offer a reliable alternative to DFIGs by eliminating the gearbox. However, PMGs scale up in size and weight much more rapidly than DFIGs as rated power is increased, presenting significant challenges for large scale wind turbine application. Thus, size reduction techniques are needed for viability of PMGs in large scale wind turbines. Two size reduction techniques are presented. It is demonstrated that 25% size reduction of a 10MW PMG is possible with a high remanence theoretical permanent magnet. Additionally, the use of a Halbach cylinder in an outer rotor PMG is investigated to focus magnetic flux over the rotor surface in order to increase torque. This work was supported by the National Science Foundation under Grant No. 1069283 and a Barbara and James Palmer Endowment at Iowa State University.

  19. Flight and size constraints: hovering performance of large hummingbirds under maximal loading.

    Science.gov (United States)

    Chai, P; Millard, D

    1997-11-01

    As the smallest birds, hummingbirds are the only birds capable of prolonged hovering. This suggests that hovering locomotion scales unfavourably with size. Is the hovering performance of larger hummingbird species more constrained by size than that of smaller ones? Maximal load-lifting capacities of the two largest species of hummingbirds found in the United States, the blue-throated (Lampornis clemenciae, 8.4 g) and magnificent (Eugenes fulgens, 7.4 g) hummingbird, as well as the two other local small species, the black-chinned (Archilochus alexandri, 3.0 g) and rufus (Selasphorus rufus, 3.3 g) hummingbird, were determined under conditions of short-burst performance. The power reserves of hummingbirds are substantial relative to normal hovering performance. The two large species lifted maximal loads close to twice their body mass for a very brief duration of over 0.4 s. The small species lifted maximal loads approximately equal to their own mass with a longer duration of over 0.6 s. For the two large species under maximal loading, estimates of burst muscle mass-specific mechanical power output assuming perfect elastic energy storage averaged 309 W kg-1, compared with 75 W kg-1 during free hovering without loading. For the two small species, these values were 228 W kg-1 and 88 W kg-1, respectively. The differences in aerodynamic force production and power output between the large and small size classes occur despite their similar wing stroke velocity. This indicates that, during burst performance in these hummingbirds, the larger ones had a higher load-lifting capacity and generated more muscle power. In spite of the twofold difference in body mass, both large and small hummingbirds have evolved to become potent aerial competitors in order to exploit their common food resource, nectar. Both size classes have evolved to cope with the multi-dimensional effects of size constraining their aerodynamics, muscle mechanics, metabolism and ecology.

  20. Extreme maximum temperature events and their relationships with large-scale modes: potential hazard on the Iberian Peninsula

    Science.gov (United States)

    Merino, Andrés; Martín, M. L.; Fernández-González, S.; Sánchez, J. L.; Valero, F.

    2017-07-01

    The aim of this paper is to analyze spatiotemporal distribution of maximum temperatures in the Iberian Peninsula (IP) by using various extreme maximum temperature indices. Thresholds for determining temperature extreme event (TEE) severity are defined using 99th percentiles of daily temperature time series for the period 1948 to 2009. The synoptic-scale fields of such events were analyzed in order to better understand the related atmospheric processes. The results indicate that the regions with a higher risk of maximum temperatures are located in the river valleys of southwest and northeast of the IP, while the Cantabrian coast and mountain ranges are characterized by lower risk. The TEEs were classified, by means of several synoptic fields (sea level pressure, temperature, and geopotential height at 850 and 500 hPa), in four clusters that largely explain their spatiotemporal distribution on the IP. The results of this study show that TEEs mainly occur associated with a ridge elongated from Subtropical areas. The relationships of TEEs with teleconnection patterns, such as the North Atlantic Oscillation (NAO), Western Mediterranean Oscillation (WeMO), and Mediterranean Oscillation (MO), showed that the interannual variability of extreme maximum temperatures is largely controlled by the dominant phase of WeMO in all seasons except wintertime where NAO is prevailing. Results related to MO pattern show less relevance in the maximum temperatures variability. The correct identification of synoptic patterns linked with the most extreme temperature event associated with each cluster will assist the prediction of events that can pose a natural hazard, thereby providing useful information for decision making and warning systems.

  1. Market size and innovation: An application to the French seed market for large crops

    OpenAIRE

    Charlot, Sylvie; Dridi, Chokri; Lemarié, Stéphane

    2015-01-01

    The aim of this paper is to analyse the impact of market size on innovation in the seed industry. The analysis is based on a panel dataset that covers 19 large crops in France during the period 1989-2012. Our econometric analysis is based on a negative binomial specification and we conduct both cross section as well as panel data analysis. We show that the French crop area always has a positive and significant effect on the number of innovations introduced each year. Market size of foreign co...

  2. Jurisdiction Size and Local Democracy: Evidence on Internal Political Efficacy from Large-scale Municipal Reform

    DEFF Research Database (Denmark)

    Lassen, David Dreyer; Serritzlew, Søren

    2011-01-01

    and problems of endogeneity. We focus on internal political efficacy, a psychological condition that many see as necessary for high-quality participatory democracy. We identify a quasiexperiment, a large-scale municipal reform in Denmark, which allows us to estimate a causal effect of jurisdiction size...... on internal political efficacy. The reform, affecting some municipalities, but not all, was implemented by the central government, and resulted in exogenous, and substantial, changes in municipal population size. Based on survey data collected before and after the reform, we find, using various difference...

  3. Control limitations from distributed sensing: theory and Extremely Large Telescope application

    OpenAIRE

    Sarlette, Alain; Sepulchre, Rodolphe

    2013-01-01

    We investigate performance bounds for feedback control of distributed plants where the controller can be centralized (i.e. it has access to measurements from the whole plant), but sensors only measure differences between neighboring subsystem outputs. Such "distributed sensing" can be a technological necessity in applications where system size exceeds accuracy requirements by many orders of magnitude. We formulate how distributed sensing generally limits feedback performance robust to measure...

  4. Floating sphere telescope: a new design for a 40-m Extremely Large Telescope

    Science.gov (United States)

    Marchiori, Gianpietro; Rampini, Francesco

    2006-06-01

    This paper work reports the results of the Preliminary Design Phase of the Floating Sphere Telescope that has been presented during the AOMATT in Xi'an, China, November 2005. The FST represents a new design for the realization of an ELT with a 40-metre primary mirror. The innovative concept of the structure and the sub-systems that constitute it as well as the use of new materials and technologies allow to obtain an instrument able to comply with very extreme specifications for structure such as ELTs. The structure allows to improve the stiffness to weight ratio of the structure, to introduce higher damping while maintaining under control the construction and maintenance costs. In comparison with the previous study, the following steps have been implemented: • Refining and optimizing the structural design and the FEA model, in particular we have included a realistic model of the constraint provided by the fluid used for flotation by characterization of its viscous and elastic properties in order to estimate the additional modal damping introduced by the flotation as function of fluid properties and geometry. • Designed (and introduced in the FEA model) various types of drives such as friction drives, tensioned ropes in "hexapod" configuration, "gravity" drives (moving ballast) and combinations of them to evaluate potential tracking performances • Designed the necessary connections for various types of utilities (power, data, cooling) • Included in the structural design a more elaborate optical design to satisfy specific science requirements (e.g. multiconjugate AO)

  5. A PROCESS FOR SOLVING A FEW EXTREME EIGENPAIRS OF LARGE SPARSE POSITIVE DEFINITE GENERALIZED EIGENVALUE PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Chong-hua Yu; O. Axelsson

    2000-01-01

    In this paper, an algorithm for computing some of the largest (smallest) generalized eigenvalues with corresponding eigenvectors of a sparse symmetric positive definite matrix pencil is presented. The algorithm uses an iteration function and inverse power iteration process to get the largest one first, then executes m-1Lanczos-like steps to get initial approximations of the next m - 1 ones, without computing any Ritz pair, for which a procedure combining Rayleigh quotient iteration with shifted inverse power iteration is used to obtain more accurate eigenvalues and eigenvectors. This algorithm keeps the advantages of preserving sparsity of the original matrices as in Lanczos method and RQI and converges with a higher rate than the method described in[12] and provides a simple technique to compute initial approximate pairs which are guaranteed to converge to the wanted m largest eigenpairs using RQI. In addition, it avoids some of the disadvantages of Lanczos and RQI, for solving extreme eigenproblems. When symmetric positive definfite linear systems must be solved in the process, an algebraic multilevel iteration method (AMLI) is applied. The algorithm is fully parallelizable.

  6. Extremely large bandwidth and ultralow-dispersion slow light in photonic crystal waveguides with magnetically controllability

    DEFF Research Database (Denmark)

    Pu, Shengli; Wang, Haotian; Wang, Ning;

    2013-01-01

    A line-defect waveguide within a two-dimensional magnetic-fluid-based photonic crystal with 45o-rotated square lattice is presented to have excellent slow light properties. The bandwidth centered at $$ \\lambda_{0} $$ = 1,550 nm of our designed W1 waveguide is around 66 nm, which is very large tha...

  7. DISCOVERY OF MASSIVE, MOSTLY STAR FORMATION QUENCHED GALAXIES WITH EXTREMELY LARGE Lyα EQUIVALENT WIDTHS AT z ∼ 3

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Yoshiaki; Kajisawa, Masaru; Kobayashi, Masakazu A. R.; Nagao, Tohru; Shioya, Yasuhiro [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho, Matsuyama 790-8577 (Japan); Scoville, Nick Z.; Capak, Peter L. [Department of Astronomy, California Institute of Technology, MS 105-24, Pasadena, CA 91125 (United States); Sanders, David B. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Toft, Sune [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Mariesvej 30, DK-2100 Copenhagen (Denmark); McCracken, Henry J. [Institut d’Astrophysique de Paris, UMR7095 CNRS, Université Pierre et Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France); Le Fèvre, Olivier; Tasca, Lidia; Ilbert, Olivier [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, F-13388 Marseille (France); Sheth, Kartik [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Renzini, Alvio [Dipartimento di Astronomia, Universita di Padova, vicolo dell’Osservatorio 2, I-35122 Padua (Italy); Lilly, Simon; Carollo, Marcella; Kovač, Katarina [Department of Physics, ETH Zurich, 8093 Zurich (Switzerland); Schinnerer, Eva, E-mail: tani@cosmos.phys.sci.ehime-u.ac.jp [MPI for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); and others

    2015-08-10

    We report a discovery of six massive galaxies with both extremely large Lyα equivalent widths (EWs) and evolved stellar populations at z ∼ 3. These MAssive Extremely STrong Lyα emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Lyα emitters (LAEs) with 12 optical intermediate-band data taken with Subaru/Suprime-Cam in the COSMOS field. Based on the spectral energy distribution fitting analysis for these LAEs, it is found that these MAESTLOs have (1) large rest-frame EWs of EW{sub 0} (Lyα) ∼ 100–300 Å, (2) M{sub ⋆} ∼ 10{sup 10.5}–10{sup 11.1} M{sub ⊙}, and (3) relatively low specific star formation rates of SFR/M{sub ⋆} ∼ 0.03–1 Gyr{sup −1}. Three of the six MAESTLOs have extended Lyα emission with a radius of several kiloparsecs, although they show very compact morphology in the HST/ACS images, which correspond to the rest-frame UV continuum. Since the MAESTLOs do not show any evidence for active galactic nuclei, the observed extended Lyα emission is likely to be caused by a star formation process including the superwind activity. We suggest that this new class of LAEs, MAESTLOs, provides a missing link from star-forming to passively evolving galaxies at the peak era of the cosmic star formation history.

  8. Discovery of Massive, Mostly Star-formation Quenched Galaxies with Extremely Large Lyman-alpha Equivalent Widths at z ~ 3

    CERN Document Server

    Taniguchi, Yoshiaki; Kobayashi, Masakazu A R; Nagao, Tohru; Shioya, Yasuhiro; Scoville, Nick Z; Sanders, David B; Capak, Peter L; Koekemoer, Anton M; Toft, Sune; McCracken, Henry J; Fevre, Olivier Le; Tasca, Lidia; Sheth, Kartik; Renzini, Alvio; Lilly, Simon; Carollo, Marcella; Kovac, Katarina; Ilbert, Olivier; Schinnerer, Eva; Fu, Hai; Tresse, Laurence; Griffiths, Richard E; Civano, Francesca

    2015-01-01

    We report a discovery of 6 massive galaxies with both extremely large Lya equivalent width and evolved stellar population at z ~ 3. These MAssive Extremely STrong Lya emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Lya emitters (LAEs) with twelve optical intermediate-band data taken with Subaru/Suprime-Cam in the COSMOS field. Based on the SED fitting analysis for these LAEs, it is found that these MAESTLOs have (1) large rest-frame equivalent width of EW_0(Lya) ~ 100--300 A, (2) M_star ~ 10^10.5--10^11.1 M_sun, and (3) relatively low specific star formation rates of SFR/M_star ~ 0.03--1 Gyr^-1. Three of the 6 MAESTLOs have extended Ly$\\alpha$ emission with a radius of several kpc although they show very compact morphology in the HST/ACS images, which correspond to the rest-frame UV continuum. Since the MAESTLOs do not show any evidence for AGNs, the observed extended Lya emission is likely to be caused by star formation process including the superwind activit...

  9. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Science.gov (United States)

    2010-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size system...

  10. Efficient Scheme for Implementing Large Size Signed Multipliers Using Multigranular Embedded DSP Blocks in FPGAs

    Directory of Open Access Journals (Sweden)

    Shuli Gao

    2009-01-01

    Full Text Available Modern FPGAs contain embedded DSP blocks, which can be configured as multipliers with more than one possible size. FPGA-based designs using these multigranular embedded blocks become more challenging when high speed and reduced area utilization are required. This paper proposes an efficient design methodology for implementing large size signed multipliers using multigranular small embedded blocks. The proposed approach has been implemented and tested targeting Altera's Stratix II FPGAs with the aid of the Quartus II software tool. The implementations of the multipliers have been carried out for operands with sizes ranging from 40 to 256 bits. Experimental results demonstrated that our design approach has outperformed the standard scheme used by Quartus II tool in terms of speed and area. On average, the delay reduction is about 20.7% and the area saving, in terms of ALUTs, is about 67.6%.

  11. Electrochemical Nanoparticle Sizing Via Nano-Impacts: How Large a Nanoparticle Can be Measured?

    Science.gov (United States)

    Bartlett, Thomas R; Sokolov, Stanislav V; Compton, Richard G

    2015-01-01

    The field of nanoparticle (NP) sizing encompasses a wide array of techniques, with electron microscopy and dynamic light scattering (DLS) having become the established methods for NP quantification; however, these techniques are not always applicable. A new and rapidly developing method that addresses the limitations of these techniques is the electrochemical detection of NPs in solution. The ‘nano-impacts’ technique is an excellent and qualitative in situ method for nanoparticle characterization. Two complementary studies on silver and silver bromide nanoparticles (NPs) were used to assess the large radius limit of the nano-impact method for NP sizing. Noting that by definition a NP cannot be larger than 100 nm in diameter, we have shown that the method quantitatively sizes at the largest limit, the lower limit having been previously reported as ∼6 nm.1 PMID:26491639

  12. Large size austenitic stainless steel forgings for nuclear and cryogenic application - development, manufacturing and properties

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Keizo; Suzuki, Komei; Sato, Ikuo; Murai, Etuso (Japan Steel Works Ltd., Muroran Plant, Hokkaido (Japan))

    1992-01-01

    The high quality one-piece large austenetic stainless steel forgings are required in the several components such as nuclear reactors and run tanks for rocket engine test stand in order to assure the structural integrity and to make it easy to fabricate and inspect the components. When the austenitic stainless steel forgings are increased in size, various problems must be overcome to assure the high quality forgings. The ingot making and hot working play an important role in determining the quality of the products. In such points, the lastest manufacturing techniques such as steel making of large size ingot and hot working to get uniform and fine grains are discussed together with the fundamental data of the material properties. (orig.).

  13. Comparative analysis of non-destructive methods to control fissile materials in large-size containers

    Directory of Open Access Journals (Sweden)

    Batyaev V.F.

    2017-01-01

    Full Text Available The analysis of various non-destructive methods to control fissile materials (FM in large-size containers filled with radioactive waste (RAW has been carried out. The difficulty of applying passive gamma-neutron monitoring FM in large containers filled with concreted RAW is shown. Selection of an active non-destructive assay technique depends on the container contents; and in case of a concrete or iron matrix with very low activity and low activity RAW the neutron radiation method appears to be more preferable as compared with the photonuclear one.

  14. Homogenous Crack-Free Large Size YBCO/YSZ/Sapphire Films for Application

    Science.gov (United States)

    Almog, B.; Azoulay, M.; Deutscher, G.

    2006-09-01

    YBa2Cu3O7-δ (YBCO) films grown on Sapphire are highly suitable for applications. The production of large size (2-3″) homogeneous, thick (d ⩾ 600nm) films of high quality is of major importance. We report the growth of such films using a buffer layer of Yttrium-stabilized ZrO2(YSZ). The films are highly homogeneous and show excellent mechanical properties. They exhibit no sign of cracking even after many thermal cycles. Their critical thickness exceeds 1000nm. However, because of the large lattice mismatch there is a decrease in the electric properties(increases Rs, decreases jc).

  15. Some Problems and Solutions of Applying TBLT in a Chinese Large-sized Class

    Institute of Scientific and Technical Information of China (English)

    周尧

    2014-01-01

    This paper mainly looks into the problems of applying Task-based Language Teaching(TBLT) and possible solutions to them.TBLT is now also widely used in Chinese classrooms.It can also be called as "the Age of Task"(Johnson,2001: P.194).However,there are still some problems when TBLT is applied in China.Most of the problems are caused by the large class size and examination-oriented education in China.

  16. DESIGN AND DEVELOPMENT OF A LARGE SIZE NON-TRACKING SOLAR COOKER

    Directory of Open Access Journals (Sweden)

    N. M. NAHAR

    2009-09-01

    Full Text Available A large size novel non-tracking solar cooker has been designed, developed and tested. The cooker has been designed in such a way that the width to length ratio for reflector and glass window is about 4 so that maximum radiation falls on the glass window. This has helped in eliminating azimuthal tracking that is required in simple hot box solar cooker towards the Sun every hour because the width to length ratio of reflector is 1. It has been found that stagnation temperatures were 118.5oC and 108oC in large size non-tracking solar cooker and hot box solar cooker respectively. It takes about 2 h for soft food and 3 h for hard food. The cooker is capable of cooking 4.0 kg of food at a time. The efficiency of the large size non-tracking solar cooker has been found to be 27.5%. The cooker saves 5175 MJ of energy per year. The cost of the cooker is Rs. 10000.00 (1.0 US$ = Rs. 50.50. The payback period has been calculated by considering 10% annual interest, 5% maintenance cost and 5% inflation in fuel prices and maintenance cost. The payback period is least, i.e. 1.58 yr., with respect to electricity and maximum, i.e. 4.89 yr., with respect to kerosene. The payback periods are in increasing order with respect to fuel: electricity, coal, firewood, liquid petroleum gas, and kerosene. The shorter payback periods suggests that the use of large size non-tracking solar cooker is economical.

  17. Scrum of scrums solution for large size teams using scrum methodology

    OpenAIRE

    Qurashi, Saja Al; Qureshi, M. Rizwan Jameel

    2014-01-01

    Scrum is a structured framework to support complex product development. However, Scrum methodology faces a challenge of managing large teams. To address this challenge, in this paper we propose a solution called Scrum of Scrums. In Scrum of Scrums, we divide the Scrum team into teams of the right size, and then organize them hierarchically into a Scrum of Scrums. The main goals of the proposed solution are to optimize communication between teams in Scrum of Scrums; to make the system work aft...

  18. Medium and large sized mammals of a semideciduous forest remnant in southern Brazil

    OpenAIRE

    Pires, Daniel Paulo de Souza; Cademartori, Cristina Vargas

    2012-01-01

    Knowledge about mammals of the Atlantic Forest is still lacking, especially because some places remain poorly studied or inventoried, which makes conservation initiatives difficult. We aimed to determine the species richness and composition of medium and large sized mammals in a semideciduous forest remnant, Morro do Coco, thus contributing information about the occurrence of mammalian fauna in the metropolitan region of Porto Alegre, southern Brazil. The methods consisted of interviews with ...

  19. Modern methods of production of large-sized multicomponent optical systems

    Science.gov (United States)

    Galyavov, Igor R.; Belousov, Sergey P.; Ignatov, Aleksandr N.; Ponin, Oleg V.; Sharov, Aleksandr A.; Domnin, Aleksandr V.

    2016-10-01

    The article describes the technology of production of large-sized multicomponent optical systems of different function. All stages of a production cycle are considered: assembly of separate units of optical components, including aspherical and off-axis mirrors; preliminary assembly and adjustment of all system; final adjustment of optical system. Modern computer-controlled methods of testings and adjustment of multicomponent optical systems, using the examples of production of such systems at JSC LZOS, are described.

  20. Scrum of scrums solution for large size teams using scrum methodology

    OpenAIRE

    Qurashi, Saja Al; Qureshi, M. Rizwan Jameel

    2014-01-01

    Scrum is a structured framework to support complex product development. However, Scrum methodology faces a challenge of managing large teams. To address this challenge, in this paper we propose a solution called Scrum of Scrums. In Scrum of Scrums, we divide the Scrum team into teams of the right size, and then organize them hierarchically into a Scrum of Scrums. The main goals of the proposed solution are to optimize communication between teams in Scrum of Scrums; to make the system work aft...

  1. On the Linkage between the Extreme Drought and Pluvial Patterns in China and the Large-Scale Atmospheric Circulation

    Directory of Open Access Journals (Sweden)

    Zengxin Zhang

    2016-01-01

    Full Text Available China is a nation that is affected by a multitude of natural disasters, including droughts and floods. In this paper, the variations of extreme drought and pluvial patterns and their relations to the large-scale atmospheric circulation have been analyzed based on monthly precipitation data from 483 stations during the period 1958–2010 in China. The results show the following: (1 the extreme drought and pluvial events in China increase significantly during that period. During 1959–1966 timeframe, more droughts occur in South China and more pluvial events are found in North China (DSC-PNC pattern; as for the period 1997–2003 (PSC-DNC pattern, the situation is the opposite. (2 There are good relationships among the extreme drought and pluvial events and the Western Pacific Subtropical High, meridional atmospheric moisture flux, atmospheric moisture content, and summer precipitation. (3 A cyclone atmospheric circulation anomaly occurs in North China, followed by an obvious negative height anomaly and a southern wind anomaly at 850 hPa and 500 hPa for the DSC-PNC pattern during the summer, and a massive ascending airflow from South China extends to North China at ~50∘N. As for the PSC-DNC pattern, the situation contrasts sharply with the DSC-PNC pattern.

  2. Global and Regional Variations in Mean Temperature and Warm Extremes in Large-Member Historical AGCM Simulation

    Science.gov (United States)

    Kamae, Y.; Shiogama, H.; Imada, Y.; Mori, M.; Arakawa, O.; Mizuta, R.; Yoshida, K.; Ishii, M.; Watanabe, M.; Kimoto, M.; Ueda, H.

    2015-12-01

    Frequency of heat extremes during the summer season has increased continuously since the late 20th century despite the global warming hiatus. In previous studies, anthropogenic influences, natural variation in sea surface temperature (SST), and internal atmospheric variabilities are suggested to be factors contributing to the increase in the frequency of warm extremes. Here 100-member ensemble historical simulations were performed (called "database for Probabilistic Description of Future climate"; d4PDF) to examine physical mechanisms responsible for the increasing hot summers and attribute to the anthropogenic influences or natural climate variability. 60km resolution MRI-AGCM ensemble simulations can reproduce historical variations in the mean temperature and warm extremes. Natural SST variability in the Pacific and Atlantic Oceans contribute to the decadal variation in the frequency of hot summers in the Northern Hemisphere middle latitude. For example, the surface temperature over western North America, including California, is largely influenced by anomalous atmospheric circulation pattern associated with Pacific SST variability. Future projections based on anomalous SST patterns derived from coupled climate model simulations will also be introduced.

  3. Design optimization of large-size format edge-lit light guide units

    Science.gov (United States)

    Hastanin, J.; Lenaerts, C.; Fleury-Frenette, K.

    2016-04-01

    In this paper, we present an original method of dot pattern generation dedicated to large-size format light guide plate (LGP) design optimization, such as photo-bioreactors, the number of dots greatly exceeds the maximum allowable number of optical objects supported by most common ray-tracing software. In the proposed method, in order to simplify the computational problem, the original optical system is replaced by an equivalent one. Accordingly, an original dot pattern is splitted into multiple small sections, inside which the dot size variation is less than the ink dots printing typical resolution. Then, these sections are replaced by equivalent cells with continuous diffusing film. After that, we adjust the TIS (Total Integrated Scatter) two-dimensional distribution over the grid of equivalent cells, using an iterative optimization procedure. Finally, the obtained optimal TIS distribution is converted into the dot size distribution by applying an appropriate conversion rule. An original semi-empirical equation dedicated to rectangular large-size LGPs is proposed for the initial guess of TIS distribution. It allows significantly reduce the total time needed to dot pattern optimization.

  4. High-speed atomic force microscopy for large scan sizes using small cantilevers

    Science.gov (United States)

    Braunsmann, Christoph; Schäffer, Tilman E.

    2010-06-01

    We present a high-speed atomic force microscope that exhibits a number of practical advantages over previous designs. Its central component is a high-speed scanner with a maximum scan size of 23 µm × 23 µm and a conveniently large sample stage area (6.5 mm × 6.5 mm). In combination with small cantilevers, image rates of up to 46 images s - 1 in air and 13 images s - 1 in liquid are reached under z-feedback control. By large scan size imaging of collagen fibrils in air, sample velocities of 8.8 mm s - 1 in the xy-direction and 11 mm s - 1 in the z-direction are reached. To provide optimized imaging conditions for both large and small scan sizes, a modular scanner design allows easily exchanging the x- and y-piezos. The scanner is therefore also suited for investigations on the molecular and atomic scale, which is demonstrated by imaging the step dynamics of a calcite surface during dissolution and the hexagonal lattice of a mica surface in liquid.

  5. Paleogenomic data suggest mammal-like genome size in the ancestral amniote and derived large genome size in amphibians.

    Science.gov (United States)

    Organ, C L; Canoville, A; Reisz, R R; Laurin, M

    2011-02-01

    An unsolved question in evolutionary genomics is whether amniote genomes have been expanding or contracting since the common ancestor of this diverse group. Here, we report on the polarity of amniote genome size evolution using genome size estimates for 14 extinct tetrapod genera from the Paleozoic and early Mesozoic Eras using osteocyte lacunae size as a correlate. We find substantial support for a phylogenetically controlled regression model relating genome size to osteocyte lacunae size (P of slopes amphibians, contractions along the diapsid lineage, and no directional change within the synapsid lineage leading to mammals.

  6. Folding and unfolding of large-size shell construction for application in Earth orbit

    Science.gov (United States)

    Kondyurin, Alexey; Pestrenina, Irena; Pestrenin, Valery; Rusakov, Sergey

    2016-07-01

    A future exploration of space requires a technology of large module for biological, technological, logistic and other applications in Earth orbits [1-3]. This report describes the possibility of using large-sized shell structures deployable in space. Structure is delivered to the orbit in the spaceship container. The shell is folded for the transportation. The shell material is either rigid plastic or multilayer prepreg comprising rigid reinforcements (such as reinforcing fibers). The unfolding process (bringing a construction to the unfolded state by loading the internal pressure) needs be considered at the presence of both stretching and bending deformations. An analysis of the deployment conditions (the minimum internal pressure bringing a construction from the folded state to the unfolded state) of large laminated CFRP shell structures is formulated in this report. Solution of this mechanics of deformable solids (MDS) problem of the shell structure is based on the following assumptions: the shell is made of components whose median surface has a reamer; in the separate structural element relaxed state (not stressed and not deformed) its median surface coincides with its reamer (this assumption allows choose the relaxed state of the structure correctly); structural elements are joined (sewn together) by a seam that does not resist rotation around the tangent to the seam line. The ways of large shell structures folding, whose median surface has a reamer, are suggested. Unfolding of cylindrical, conical (full and truncated cones), and large-size composite shells (cylinder-cones, cones-cones) is considered. These results show that the unfolding pressure of such large-size structures (0.01-0.2 atm.) is comparable to the deploying pressure of pneumatic parts (0.001-0.1 atm.) [3]. It would be possible to extend this approach to investigate the unfolding process of large-sized shells with ruled median surface or for non-developable surfaces. This research was

  7. A photonic-crystal optical antenna for extremely large local-field enhancement.

    Science.gov (United States)

    Chang, Hyun-Joo; Kim, Se-Heon; Lee, Yong-Hee; Kartalov, Emil P; Scherer, Axel

    2010-11-08

    We propose a novel design of an all-dielectric optical antenna based on photonic-band-gap confinement. Specifically, we have engineered the photonic-crystal dipole mode to have broad spectral response (Q~70) and well-directed vertical-radiation by introducing a plane mirror below the cavity. Considerably large local electric-field intensity enhancement~4,500 is expected from the proposed design for a normally incident planewave. Furthermore, an analytic model developed based on coupled-mode theory predicts that the electric-field intensity enhancement can easily be over 100,000 by employing reasonably high-Q (~10,000) resonators.

  8. Extremes of N vicious walkers for large N: application to the directed polymer and KPZ interfaces

    CERN Document Server

    Schehr, Gregory

    2012-01-01

    We compute the joint probability distribution function (jpdf) P_N(M, \\tau_M) of the maximum M and its position \\tau_M for N non-intersecting Brownian excursions, on the unit time interval, in the large N limit. For N \\to \\infty, this jpdf is peaked around M = \\sqrt{2N} and \\tau_M = 1/2, while the typical fluctuations behave for large N like M - \\sqrt{2N} \\propto s N^{-1/6} and \\tau_M - 1/2 \\propto w N^{-1/3} where s and w are correlated random variables. One obtains an explicit expression of the limiting jpdf P(s,w) in terms of the Tracy-Widom distribution for the Gaussian Orthogonal Ensemble (GOE) of Random Matrix Theory and the psi-function for the Hastings-McLeod solution to the Painlev\\'e II equation. Our result yields, up to a rescaling of the random variables s and w, an expression for the jpdf of the maximum and its position for the Airy_2 process minus a parabola. This latter describes the fluctuations in many different physical systems belonging to the Kardar-Parisi-Zhang (KPZ) universality class in ...

  9. A highly efficient multi-core algorithm for clustering extremely large datasets

    Directory of Open Access Journals (Sweden)

    Kraus Johann M

    2010-04-01

    Full Text Available Abstract Background In recent years, the demand for computational power in computational biology has increased due to rapidly growing data sets from microarray and other high-throughput technologies. This demand is likely to increase. Standard algorithms for analyzing data, such as cluster algorithms, need to be parallelized for fast processing. Unfortunately, most approaches for parallelizing algorithms largely rely on network communication protocols connecting and requiring multiple computers. One answer to this problem is to utilize the intrinsic capabilities in current multi-core hardware to distribute the tasks among the different cores of one computer. Results We introduce a multi-core parallelization of the k-means and k-modes cluster algorithms based on the design principles of transactional memory for clustering gene expression microarray type data and categorial SNP data. Our new shared memory parallel algorithms show to be highly efficient. We demonstrate their computational power and show their utility in cluster stability and sensitivity analysis employing repeated runs with slightly changed parameters. Computation speed of our Java based algorithm was increased by a factor of 10 for large data sets while preserving computational accuracy compared to single-core implementations and a recently published network based parallelization. Conclusions Most desktop computers and even notebooks provide at least dual-core processors. Our multi-core algorithms show that using modern algorithmic concepts, parallelization makes it possible to perform even such laborious tasks as cluster sensitivity and cluster number estimation on the laboratory computer.

  10. A simple method for estimating genetic diversity in large populations from finite sample sizes

    Directory of Open Access Journals (Sweden)

    Rajora Om P

    2009-12-01

    Full Text Available Abstract Background Sample size is one of the critical factors affecting the accuracy of the estimation of population genetic diversity parameters. Small sample sizes often lead to significant errors in determining the allelic richness, which is one of the most important and commonly used estimators of genetic diversity in populations. Correct estimation of allelic richness in natural populations is challenging since they often do not conform to model assumptions. Here, we introduce a simple and robust approach to estimate the genetic diversity in large natural populations based on the empirical data for finite sample sizes. Results We developed a non-linear regression model to infer genetic diversity estimates in large natural populations from finite sample sizes. The allelic richness values predicted by our model were in good agreement with those observed in the simulated data sets and the true allelic richness observed in the source populations. The model has been validated using simulated population genetic data sets with different evolutionary scenarios implied in the simulated populations, as well as large microsatellite and allozyme experimental data sets for four conifer species with contrasting patterns of inherent genetic diversity and mating systems. Our model was a better predictor for allelic richness in natural populations than the widely-used Ewens sampling formula, coalescent approach, and rarefaction algorithm. Conclusions Our regression model was capable of accurately estimating allelic richness in natural populations regardless of the species and marker system. This regression modeling approach is free from assumptions and can be widely used for population genetic and conservation applications.

  11. Exoplanet Science with the European Extremely Large Telescope. The Case for Visible and Near-IR Spectroscopy at High Resolution

    CERN Document Server

    Udry, S; Bouchy, F; Cameron, A Collier; Henning, T; Mayor, M; Pepe, F; Piskunov, N; Pollacco, D; Queloz, D; Quirrenbach, A; Rauer, H; Rebolo, R; Santos, N C; Snellen, I; Zerbi, F

    2014-01-01

    Exoplanet science is booming. In 20 years our knowledge has expanded considerably, from the first discovery of a Hot Jupiter, to the detection of a large population of Neptunes and super-Earths, to the first steps toward the characterization of exoplanet atmospheres. Between today and 2025, the field will evolve at an even faster pace with the advent of several space-based transit search missions, ground-based spectrographs, high-contrast imaging facilities, and the James Webb Space Telescope. Especially the ESA M-class PLATO mission will be a game changer in the field. From 2024 onwards, PLATO will find transiting terrestrial planets orbiting within the habitable zones of nearby, bright stars. These objects will require the power of Extremely Large Telescopes (ELTs) to be characterized further. The technique of ground-based high-resolution spectroscopy is establishing itself as a crucial pathway to measure chemical composition, atmospheric structure and atmospheric circulation in transiting exoplanets. A hig...

  12. MRI induced second-degree burn in a patient with extremely large uterine leiomyomas: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Min; Kang, Bo Kyeong; Song, Soon Young; Koh, Byung Hee; Choi, Joong Sub; Lee, Won Moo [Hanyang University Medical Center, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2015-12-15

    Burns and thermal injuries related with magnetic resonance imaging (MRI) are rare. Previous literature indicates that medical devices with cable, cosmetics or tattoo are known as risk factors for burns and thermal injuries. However, there is no report of MRI-related burns in Korea. Herein, we reported a case of deep second degree burn after MRI in a 38-year-old female patient with multiple uterine leiomyomas including some that were large and degenerated. The large uterine leiomyoma-induced protruded anterior abdominal wall in direct contact with the body coil during MRI was suspected as the cause of injury, by retrospective analysis. Therefore, awareness of MRI related thermal injury is necessary to prevent this hazard, together with extreme care during MRI.

  13. Successful flexible bronchoscopic management of a large-sized aspirated partial denture.

    Science.gov (United States)

    Jamshed, Nayer; Madan, Karan; Ekka, Meera; Guleria, Randeep

    2014-03-20

    A 48-year-old male patient presented to the emergency room with a history of chest pain and breathlessness. Chest X-ray demonstrated a large radio-opaque foreign body in relation to the proximal right bronchial tree. The patient subsequently revealed a history of a misplaced denture 4 months previously. Urgent flexible bronchoscopy (FB) examination demonstrated a large partial denture impacted in the right intermediate bronchus, which was removed successfully using a flexible bronchoscope. Although rigid bronchoscopy (RB) is the procedure of choice for large-sized and impacted airway foreign bodies, the present case highlights the utility of FB in airway foreign body removal. In clinically stable patients with foreign body inhalation, FB can be employed initially as it is an outpatient and cost-effective procedure which can obviate the need for administration of general anaesthesia.

  14. The Vascularized Fibular Graft in the Pediatric Upper Extremity: A Durable, Biological Solution to Large Oncologic Defects

    Directory of Open Access Journals (Sweden)

    Nicki Zelenski

    2013-01-01

    Full Text Available Skeletal reconstruction after large tumor resection is challenging. The free vascularized fibular graft (FVFG offers the potential for rapid autograft incorporation as well as growing physeal transfer in pediatric patients. We retrospectively reviewed eleven pediatric patients treated with FVFG reconstructions of the upper extremity after tumor resection. Eight male and three female patients were identified, including four who underwent epiphyseal transfer. All eleven patients retained a functional salvaged limb. Nonunion and graft fracture were the most common complications relating to graft site (27%. Peroneal nerve palsy occurred in 4/11 patients, all of whom received epiphyseal transfer. Patients receiving epiphyseal transplant had a mean annual growth of 1.7 cm/year. Mean graft hypertrophy index increased by more than 10% in all cases. Although a high complication rate may be anticipated, the free vascularized fibula may be used to reconstruct large skeletal defects in the pediatric upper extremity after oncologic resection. Transferring the vascularized physis is a viable option when longitudinal growth is desired.

  15. Effect of Large Finite-Size Wind Farms and Their Wakes on Atmospheric Boundary Layer Dynamics

    Science.gov (United States)

    Wu, Ka Ling; Porté-Agel, Fernando

    2016-04-01

    Through the use of large-eddy simulation, the effect of large finite-size wind farms and their wakes on conventionally-neutral atmospheric boundary layer (ABL) dynamics and power extraction is investigated. Specifically, this study focuses on a wind farm that comprises 25 rows of wind turbines, spanning a distance of 10 km. It is shown that large wind farms have a significant effect on internal boundary layer growth both inside and downwind of the wind farms. If the wind farm is large enough, the internal boundary layer interacts with the thermally-stratified free atmosphere above, leading to a modification of the ABL height and power extraction. In addition, it is shown that large wind farms create extensive wakes, which could have an effect on potential downwind wind farms. Specifically, for the case considered here, a power deficit as large as 8% is found at a distance of 10 km downwind from the wind farm. Furthermore, this study compares the wind farm wake dynamics for cases in which the conventionally neutral ABLs are driven by a unidirectional pressure gradient and Coriolis forces.

  16. Occurrence of large and medium-sized mammals: Occurrence but not count models predict pronghorn distribution: Chapter 8

    Science.gov (United States)

    2011-01-01

    Management of medium to large-sized terrestrial mammals (Antilocapridae, Canidae, Cervidae, Leporidae, Mustelidae, Ochotonidae) in the western United States is multifaceted and complex. Species in this group generally are charismatic and provide economic opportunities, although others are considered a nuisance at one extreme or are listed as species of conservation concern at the other. Understanding the relative influence of land cover, habitat fragmentation, and human land use on their distribution during the breeding season is imperative to inform management decisions on land use and conservation planning for these species. We surveyed medium to large-sized sagebrush (Artemisia spp.)-associated mammal species in 2005 and 2006 on 141 random transects (mean length = 1.1 km) in the Wyoming Basins, an area undergoing rapid land cover transformation due to human actions including energy development. Overall, we observed 10 species but only obtained enough observations of pronghorn (Antilocapra americana) to develop spatially explicit distribution models. For pronghorn, occurrence related positively to proportion of sagebrush land cover within 0.27 km, mixed shrubland land cover within 3 km, riparian land cover within 5 km, Normalized Difference Vegetation Index (NDVI) within 0.27 km, road density within 5 km, and decay distance to power line corridors at 1 km, but negatively to salt-desert shrubland cover within 18 km and an interaction between sagebrush and NDVI within 0.27 km. We found excellent predictive capability of this model when evaluated with independent test data. The model provides a basis for assessing the effects of proposed development on pronghorn and can aid planning efforts to avoid or mitigate adverse effects on pronghorn.

  17. The OVLA 1.5-m primary as a segment for an Extremely Large Telescope?

    Science.gov (United States)

    Arnold, L.; Lardière, O.; Dejonghe, J.

    The Optical Very Large Array (OVLA) 1.5 m prototype telescope is under construction at Observatoire de Haute Provence. This telescope features a thin active parabolic f/1.7 mirror, weighting 100 kg/m^2 with the active cell. The meniscus-shaped mirror, made of low-cost ordinary window glass, is 24.1 mm thick and supported by 32 actuators, each ensuring both axial and lateral supporting via a glued triple contact point under the mirror. The active optics system is briefly described, as well as the mirror thermal behaviour and how we plan to correct in situ the related deformations. We discuss the characteristics of this mirror concept (weight, low-cost, thermal behaviour, wind buffeting) of this mirror concept versus its application to ELT primary mirror active segments.

  18. Large Scale Behavior and Droplet Size Distributions in Crude Oil Jets and Plumes

    Science.gov (United States)

    Katz, Joseph; Murphy, David; Morra, David

    2013-11-01

    The 2010 Deepwater Horizon blowout introduced several million barrels of crude oil into the Gulf of Mexico. Injected initially as a turbulent jet containing crude oil and gas, the spill caused formation of a subsurface plume stretching for tens of miles. The behavior of such buoyant multiphase plumes depends on several factors, such as the oil droplet and bubble size distributions, current speed, and ambient stratification. While large droplets quickly rise to the surface, fine ones together with entrained seawater form intrusion layers. Many elements of the physics of droplet formation by an immiscible turbulent jet and their resulting size distribution have not been elucidated, but are known to be significantly influenced by the addition of dispersants, which vary the Weber Number by orders of magnitude. We present experimental high speed visualizations of turbulent jets of sweet petroleum crude oil (MC 252) premixed with Corexit 9500A dispersant at various dispersant to oil ratios. Observations were conducted in a 0.9 m × 0.9 m × 2.5 m towing tank, where large-scale behavior of the jet, both stationary and towed at various speeds to simulate cross-flow, have been recorded at high speed. Preliminary data on oil droplet size and spatial distributions were also measured using a videoscope and pulsed light sheet. Sponsored by Gulf of Mexico Research Initiative (GoMRI).

  19. Estimating the Size of a Large Network and its Communities from a Random Sample

    CERN Document Server

    Chen, Lin; Crawford, Forrest W

    2016-01-01

    Most real-world networks are too large to be measured or studied directly and there is substantial interest in estimating global network properties from smaller sub-samples. One of the most important global properties is the number of vertices/nodes in the network. Estimating the number of vertices in a large network is a major challenge in computer science, epidemiology, demography, and intelligence analysis. In this paper we consider a population random graph G = (V;E) from the stochastic block model (SBM) with K communities/blocks. A sample is obtained by randomly choosing a subset W and letting G(W) be the induced subgraph in G of the vertices in W. In addition to G(W), we observe the total degree of each sampled vertex and its block membership. Given this partial information, we propose an efficient PopULation Size Estimation algorithm, called PULSE, that correctly estimates the size of the whole population as well as the size of each community. To support our theoretical analysis, we perform an exhausti...

  20. Characterizing the Large (cm-size) Grains Around Comet 103P/Hartley 2

    Science.gov (United States)

    Sunshine, Jessica M.; Feaga, Lori M.; Farnham, Tony; Protopapa, Silvia; Kelley, Michael S.; Engle, Anna

    2016-10-01

    During the flyby of comet 103P/Hartley 2, two populations of bright grains were identified in the coma. Small, 1 µm-sized, water ice-rich grains were observed near the small end of the nucleus that were dragged from the interior by CO2 gas emissions. At closest approach a population of larger grains was clearly seen in visible images off the large lobe. The estimated brightness of the isolated grains suggests that they are likely cm-sized particles and likely water ice-rich. Both sets of grains were simultaneously observed in visible images, at two different resolutions, and by Deep Impact infrared spectrometer. However, because of the difficulty in finding isolated grains in the infrared slit, the population of larger grains has not previously been characterized. Doing so allows us to determine both the reflected and thermal properties of the grains, which when compared to visible images can be used to constrain the size of the grains. Their spectral properties can also be used to definitively detect water ice as has been assumed from visible albedos. In addition, the infrared spectra can be used estimate the relative abundance and particle sizes of ice and non-ice components. The velocity and dynamics of these larger grains can also be characterized. These data will be compared with those of the population of smaller grains emanated directly from the nucleus.Funding from NASA'S Discovery Data Analysis Program (NNX16AJ93G) is greatfully acknowledged.

  1. Assessing the impact of climate and land use changes on extreme floods in a large tropical catchment

    Science.gov (United States)

    Jothityangkoon, Chatchai; Hirunteeyakul, Chow; Boonrawd, Kowit; Sivapalan, Murugesu

    2013-05-01

    In the wake of the recent catastrophic floods in Thailand, there is considerable concern about the safety of large dams designed and built some 50 years ago. In this paper a distributed rainfall-runoff model appropriate for extreme flood conditions is used to generate revised estimates of the Probable Maximum Flood (PMF) for the Upper Ping River catchment (area 26,386 km2) in northern Thailand, upstream of location of the large Bhumipol Dam. The model has two components: a continuous water balance model based on a configuration of parameters estimated from climate, soil and vegetation data and a distributed flood routing model based on non-linear storage-discharge relationships of the river network under extreme flood conditions. The model is implemented under several alternative scenarios regarding the Probable Maximum Precipitation (PMP) estimates and is also used to estimate the potential effects of both climate change and land use and land cover changes on the extreme floods. These new estimates are compared against estimates using other hydrological models, including the application of the original prediction methods under current conditions. Model simulations and sensitivity analyses indicate that a reasonable Probable Maximum Flood (PMF) at the dam site is 6311 m3/s, which is only slightly higher than the original design flood of 6000 m3/s. As part of an uncertainty assessment, the estimated PMF is sensitive to the design method, input PMP, land use changes and the floodplain inundation effect. The increase of PMP depth by 5% can cause a 7.5% increase in PMF. Deforestation by 10%, 20%, 30% can result in PMF increases of 3.1%, 6.2%, 9.2%, respectively. The modest increase of the estimated PMF (to just 6311 m3/s) in spite of these changes is due to the factoring of the hydraulic effects of trees and buildings on the floodplain as the flood situation changes from normal floods to extreme floods, when over-bank flows may be the dominant flooding process, leading

  2. Effect of drop size on the impact thermodynamics for supercooled large droplet in aircraft icing

    Science.gov (United States)

    Zhang, Chen; Liu, Hong

    2016-06-01

    Supercooled large droplet (SLD), which can cause abnormal icing, is a well-known issue in aerospace engineering. Although efforts have been exerted to understand large droplet impact dynamics and the supercooled feature in the film/substrate interface, respectively, the thermodynamic effect during the SLD impact process has not received sufficient attention. This work conducts experimental studies to determine the effects of drop size on the thermodynamics for supercooled large droplet impingement. Through phenomenological reproduction, the rapid-freezing characteristics are observed in diameters of 400, 800, and 1300 μm. The experimental analysis provides information on the maximum spreading rate and the shrinkage rate of the drop, the supercooled diffusive rate, and the freezing time. A physical explanation of this unsteady heat transfer process is proposed theoretically, which indicates that the drop size is a critical factor influencing the supercooled heat exchange and effective heat transfer duration between the film/substrate interface. On the basis of the present experimental data and theoretical analysis, an impinging heating model is developed and applied to typical SLD cases. The model behaves as anticipated, which underlines the wide applicability to SLD icing problems in related fields.

  3. Modeling and simulation of 3D thermal stresses of large-sized castings in solidification processes

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large- sized steel castings, aluminum castings and etc. Some defects of hot cracking by thermal stress often appear during solidification process as these castings are produced, which results in failure of castings.Therefore predicting the effects of technological parameters for production of castings on the thermal stress during solidification process becomes an important means. In this paper, the mathematical models have been established and numerical calculation of temperature fields by using finite difference method (FDM) and then thermal stress fields by using finite element method (FEM) during solidification process of castings have been carried out. The technological parameters of production have been optimized by the results of calculation and the defects of hot cracking have been eliminated. Modeling and simulation of 3D thermal stress during solidification processes of large-sized castings provided a scientific basis, which promoted further development of advanced manufacturing technique.

  4. Biophysical interactions control the size and abundance of large phytoplankton chains at the Ushant tidal front.

    Directory of Open Access Journals (Sweden)

    José M Landeira

    Full Text Available Phytoplankton blooms are usually dominated by chain-forming diatom species that can alter food pathways from primary producers to predators by reducing the interactions between intermediate trophic levels. The food-web modifications are determined by the length of the chains; however, the estimation is biased because traditional sampling strategies damage the chains and, therefore, change the phytoplankton size structure. Sedimentological studies around oceanic fronts have shown high concentrations of giant diatom mats (>1 cm in length, suggesting that the size of diatom chains is underestimated in the pelagic realm. Here, we investigate the variability in size and abundance of phytoplankton chains at the Ushant tidal front (NW France using the Video Fluorescence Analyzer (VFA, a novel and non-invasive system. CTD and Scanfish profiling characterized a strong temperature and chlorophyll front, separating mixed coastal waters from the oceanic-stratified domain. In order to elucidate spring-neap variations in the front, vertical microstructure profiler was used to estimate the turbulence and vertical nitrate flux. Key findings were: (1 the VFA system recorded large diatom chains up to 10.7 mm in length; (2 chains were mainly distributed in the frontal region, with maximum values above the pycnocline in coincidence with the maximum chlorophyll; (3 the diapycnal fluxes of nitrate enabled the maintenance of the bloom in the frontal area throughout the spring-neap tidal cycle; (4 from spring to neap tide the chains length was significantly reduced; (5 during neap tide, the less intense vertical diffusion of nutrients, as well as the lower turbulence around the chains, intensified nutrient-depleted conditions and, thus, very large chains became disadvantageous. To explain this pattern, we suggest that size plasticity is an important ecological trait driving phytoplankton species competition. Although this plasticity behavior is well known from

  5. West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic

    Directory of Open Access Journals (Sweden)

    S. Ta

    2016-01-01

    Full Text Available Based on daily precipitation from the Global Precipitation Climatology Project (GPCP data during April–October of the 1997–2014 period, the daily extreme rainfall trends and variability over West Africa are characterized using 90th-percentile threshold at each grid point. The contribution of the extreme rainfall amount reaches ~50–90% in the northern region while it is ~30–50% in the south. The yearly cumulated extreme rainfall amount indicates significant and negative trends in the 6°N–12°N; 6°N–12°N; 17°W–10°W and 4°N–7°N; 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E domains, while the number of days exhibits nonsignificant trends over West Africa. The empirical orthogonal functions performed on the standardized anomalies show four variability modes that include all West Africa with a focus on the Sahelian region, the eastern region including the south of Nigeria, the western part including Guinea, Sierra Leone, Liberia, and Guinea-Bissau, and finally a small region at the coast of Ghana and Togo. These four modes are influenced differently by the large-scale ocean surface and atmospheric conditions in the tropical Atlantic. The results are applicable in planning the risks associated with these climate hazards, particularly on water resource management and civil defense.

  6. RESOURCE SAVING TECHNOLOGICAL PROCESS OF LARGE-SIZE DIE THERMAL TREATMENT

    Directory of Open Access Journals (Sweden)

    L. A. Glazkov

    2009-01-01

    Full Text Available The given paper presents a development of a technological process pertaining to hardening large-size parts made of die steel. The proposed process applies a water-air mixture instead of a conventional hardening medium that is industrial oil.While developing this new technological process it has been necessary to solve the following problems: reduction of thermal treatment duration, reduction of power resource expense (natural gas and mineral oil, elimination of fire danger and increase of process ecological efficiency. 

  7. Development of Large-size Ultrasonic Sonotrodes for Cavitation Treatment of Molten Metals

    Science.gov (United States)

    Komarov, Sergey; Ishiwata, Yasuo

    This work presents results of the development of large-size high-amplitude ceramic sonotrodes destined for use in cavitation treatment of molten metals. The sonotrodes were characterized for their vibration amplitude, erosion resistance and cavitation-producing ability in aluminum melts. The ability of the sonotrodes to refine the grain structure was examined by applying them to the DC casting of Al-Si hypereutectic alloys. The results showed that the sonotrodes have excellent performance characteristics, and they possess far superior erosion resistance and endurance than those made of such high-resistance refractory metals as Nb alloys.

  8. Verification measurements of the IRMM-1027 and the IAEA large-sized dried (LSD) spikes.

    Science.gov (United States)

    Jakopič, R; Aregbe, Y; Richter, S; Zuleger, E; Mialle, S; Balsley, S D; Repinc, U; Hiess, J

    2017-01-01

    In the frame of the accountancy measurements of the fissile materials, reliable determinations of the plutonium and uranium content in spent nuclear fuel are required to comply with international safeguards agreements. Large-sized dried (LSD) spikes of enriched (235)U and (239)Pu for isotope dilution mass spectrometry (IDMS) analysis are routinely applied in reprocessing plants for this purpose. A correct characterisation of these elements is a pre-requirement for achieving high accuracy in IDMS analyses. This paper will present the results of external verification measurements of such LSD spikes performed by the European Commission and the International Atomic Energy Agency.

  9. Accelerating inference for diffusions observed with measurement error and large sample sizes using approximate Bayesian computation

    DEFF Research Database (Denmark)

    Picchini, Umberto; Forman, Julie Lyng

    2016-01-01

    In recent years, dynamical modelling has been provided with a range of breakthrough methods to perform exact Bayesian inference. However, it is often computationally unfeasible to apply exact statistical methodologies in the context of large data sets and complex models. This paper considers...... a nonlinear stochastic differential equation model observed with correlated measurement errors and an application to protein folding modelling. An approximate Bayesian computation (ABC)-MCMC algorithm is suggested to allow inference for model parameters within reasonable time constraints. The ABC algorithm...... applications. A simulation study is conducted to compare our strategy with exact Bayesian inference, the latter resulting two orders of magnitude slower than ABC-MCMC for the considered set-up. Finally, the ABC algorithm is applied to a large size protein data. The suggested methodology is fairly general...

  10. Temperature Uniformity of Wafer on a Large-Sized Susceptor for a Nitride Vertical MOCVD Reactor

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Ming; JIANG Hai-Ying; HAN Yan-Bin; LI Jin-Ping; YIN Jian-Qin; ZHANG Jin-Cheng

    2012-01-01

    The effect of coil location on wafer temperature is analyzed in a vertical MOCVD reactor by induction heating.It is observed that the temperature distribution in the wafer with the coils under the graphite susceptor is more uniform than that with the coils around the outside wall of the reactor.For the case of coils under the susceptor,we find that the thickness of the susceptor,the distance from the coils to the susceptor bottom and the coil turns significantly affect the temperature uniformity of the wafer. An optimization process is executed for a 3-inch susceptor with this kind of structure,resulting in a large improvement in the temperature uniformity.A further optimization demonstrates that the new susceptor structure is also suitable for either multiple wafers or large-sized wafers approaching 6 and 8 inches.

  11. Dislocation Analysis for Large-sized Sapphire Single Crystal Grown by SAPMAC Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, large-sized sapphire (Φ230×210 mm, 27.5 kg) was grown by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at the cooled center). Dislocation peculiarity in large sapphire boule (0001) basal plane was investigated by chemical etching, scanning electron microscopy and X-ray topography method. The triangular dislocation etch pit measured is 7.6×101~8.0×102 cm-2, in which relative high-density dislocations were generated at both initial and final stages of crystal growth. The analysis of single-crystal X-ray topography shows that there are no apparent sub-grain boundaries; the dislocation lines are isolated and straight. Finally, the origins of low-density dislocation in sapphire crystal are discussed by numerical analysis method.

  12. Spitzer SAGE-Spec: Near Infrared Spectroscopy, Dust Shells, and Cool Envelopes in Extreme Large Magellanic Cloud AGB Stars

    CERN Document Server

    Blum, R D; Kemper, F; Ling, B; Volk, K

    2014-01-01

    K-band spectra are presented for a sample of 39 Spitzer IRS SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near infrared - Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars were chosen from the luminous and red extreme "tip" of the color magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich "stellar" cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near infrared and mid infrared colors. One object in our sample, HV 915, a known post asymptotic giant branch star of the RV Tau type exhibits CO 2.3 micron band head emission consistent with previ...

  13. Mechanisms for exporting large-sized cargoes from the endoplasmic reticulum.

    Science.gov (United States)

    Saito, Kota; Katada, Toshiaki

    2015-10-01

    Cargo proteins exported from the endoplasmic reticulum to the Golgi apparatus are typically transported in coat protein complex II (COPII)-coated vesicles of 60-90 nm diameter. Several cargo molecules including collagens and chylomicrons form structures that are too large to be accommodated by these vesicles, but their secretion still requires COPII proteins. Here, we first review recent progress on large cargo secretions derived especially from animal models and human diseases, which indicate the importance of COPII proteins. We then discuss the recent isolation of specialized factors that modulate the process of COPII-dependent cargo formation to facilitate the exit of large-sized cargoes from the endoplasmic reticulum. Based on these findings, we propose a model that describes the importance of the GTPase cycle for secretion of oversized cargoes. Next, we summarize reports that describe the structures of COPII proteins and how these results provide insight into the mechanism of assembly of the large cargo carriers. Finally, we discuss what issues remain to be solved in the future.

  14. Improving attosecond pulse reflection by large angle incidence for a periodic multilayer mirror in the extreme ultraviolet region

    Institute of Scientific and Technical Information of China (English)

    Lin Cheng-You; Chen Shu-Jing; Liu Da-He

    2013-01-01

    The improvement of attosecond pulse reflection by large angle incidence for a periodic multilayer mirror in the extreme ultraviolet region has been discussed.Numerical simulations of both spectral and temporal reflection characteristics of periodic multilayer mirrors under various incident angles have been analyzed and compared.It was found that the periodic multilayer mirror under a larger incidence angle can provide not only higher integrated reflectivity but also a broader reflection band with negligible dispersion,making it possible to obtain better a reflected pulse that has a higher pulse reflection efficiency and shorter pulse duration for attosecond pulse reflection.In addition,by increasing the incident angle,the promotion of attosecond pulse reflection capability has been proven for periodic multilayer mirrors with arbitrary layers.

  15. Parallel algorithm of solidification process simulation for large-sized system of liquid metal atoms

    Institute of Scientific and Technical Information of China (English)

    董科军; 刘让苏; 郑采星; 刘海蓉; 彭平; 卢小勇; 胡庆丰; 何新芳

    2003-01-01

    A parallel arithmetic program for the molecular dynamics (MD) simulation study of a large-sized system consisting of 50 000-100 000 atoms of liquid metals is reformed, based on the cascade arithmetic program used for the molecular dynamics simulation study of a small-sized system consisting of 500-1 000 atoms. The program is used to simulate the rapid solidification processes of liquid metal Al system. Some new results, such as larger clusters composed of more than 3-6 smaller clusters (icosahedra or defect icosahedra) obtained in the system of 50 000 atoms, however, the larger clusters can not be seen in the small-sized system of 500-1 000 atoms. On the other hand, the results from this simulation study would be more closed to the real situation of the system under consideration because the influence of boundary conditions is decreased remarkably. It can be expected that from the parallel algorithm combined with the higher performance super-computer, the total number of atoms in simulation system can be enlarged again up to tens, even hundreds times in the near future.

  16. Effect of polymorphism in the leukemia inhibitory factor gene on litter size in Large White pigs.

    Science.gov (United States)

    Lin, H C; Liu, G F; Wang, A G; Kong, L J; Wang, X F; Fu, J L

    2009-09-01

    DNA polymorphism of the porcine leukemia inhibitory factory (LIF) was investigated and used to study the effects on litter size in Large White pigs. A total of 2,167 litter records from 420 sows genotyped at two SNP loci (LIF1 and LIF2) within LIF gene were analyzed to determine whether LIF influenced total number born (TNB) and number born alive (NBA). The results indicated that B allele at LIF1 locus and A allele at LIF2 locus seem to have advantageous effects on litter size. However, the combined analyzed results demonstrated that genotype AAAA, ABBB, and BBBB are better than genotype AAAB, AABB, and ABAB for TNB and NBA in either third to eighth parity or all parities. In all parities, the sows with AAAA genotype had an advantage of 1.76 piglets (P NBA per litter over the AAAB sows, respectively. The results in this study demonstrated that LIF gene was significantly associated with litter size in pigs.

  17. Flower size and longevity influence florivory in the large-flowered shrub Cistus ladanifer

    Science.gov (United States)

    Teixido, Alberto L.; Méndez, Marcos; Valladares, Fernando

    2011-09-01

    Plants with larger and longer-lived flowers receive more pollinator visits and increase reproductive success, though may also suffer more from antagonistic interactions with animals. Florivores can reduce fruit and seed production, so selection on flower size, floral longevity and/or number of flowers may thus be determined by the relative effects of both pollinators and florivores. In this study flowers of Cistus ladanifer, a large-flowered Mediterranean shrub, were monitored to evaluate the effects of flower size, floral longevity and number of flowers on levels of florivory in four populations. Number of flowers was variable but did not differ among populations. Both flower size and floral longevity of C. ladanifer showed broad variation and significantly differed among populations. Overall, 7% of flowers suffered attack by florivores, which were mainly ants picking the stamens and beetles consuming petals and pollen. Within-populations, larger and longer-lived flowers tended to be affected by florivores more frequently. The low overall incidence of florivores and its lack of between-population variation suggest that florivory may not influence intraspecific variation of these floral traits. However, moderate florivory levels on the largest and longest-lived flowers open the possibility of exerting selection towards smaller and shorter-lived flowers in some of the populations studied.

  18. Fragmentation and reliable size distributions of large ammonia and water clusters

    Science.gov (United States)

    Bobbert, C.; Schütte, S.; Steinbach, C.; Buck, U.

    2002-05-01

    The interaction of large ammonia and water clusters in the size range from < n rangle = 10 to 3 400 with electrons is investigated in a reflectron time-of-flight mass spectrometer. The clusters are generated in adiabatic expansions through conical nozzles and are nearly fragmentation free detected by single photon ionization after they have been doped by one sodium atom. For ammonia also the (1+1) resonance enhanced two photon ionization through the tilde A state with v=6 operates similarly. In this way reliable size distributions of the neutral clusters are obtained which are analyzed in terms of a modified scaling law of the Hagena type [Surf. Sci. 106, 101 (1981)]. In contrast, using electron impact ionization, the clusters are strongly fragmented when varying the electron energy between 150 and 1 500 eV. The number of evaporated molecules depends on the cluster size and the energy dependence follows that of the stopping power of the solid material. Therefore we attribute the operating mechanism to that which is also responsible for the electronic sputtering of solid matter. The yields, however, are orders of magnitude larger for clusters than for the solid. This result is a consequence of the finite dimensions of the clusters which cannot accommodate the released energy.

  19. Shift in a large river fish assemblage: body-size and trophic structure dynamics.

    Directory of Open Access Journals (Sweden)

    Kyle J Broadway

    Full Text Available As the intensity and speed of environmental change increase at both local and global scales it is imperative that we gain a better understanding of the ecological implications of community shifts. While there has been substantial progress toward understanding the drivers and subsequent responses of community change (e.g. lake trophic state, the ecological impacts of food web changes are far less understood. We analyzed Wabash River fish assemblage data collected from 1974-2008, to evaluate temporal variation in body-size structure and functional group composition. Two parameters derived from annual community size-spectra were our major response variables: (1 the regression slope is an index of ecological efficiency and predator-prey biomass ratios, and (2 spectral elevation (regression midpoint height is a proxy for food web capacity. We detected a large assemblage shift, over at least a seven year period, defined by dramatic changes in abundance (measured as catch-per-unit-effort of the dominant functional feeding groups among two time periods; from an assemblage dominated by planktivore-omnivores to benthic invertivores. There was a concurrent increase in ecological efficiency (slopes increased over time following the shift associated with an increase in large-bodied low trophic level fish. Food web capacity remained relatively stable with no clear temporal trends. Thus, increased ecological efficiency occurred simultaneous to a compensatory response that shifted biomass among functional feeding groups.

  20. Prototyping of Hexagonal Light Concentrators for the Large-Sized Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    Reflective light concentrators with hexagonal entrance and exit apertures are frequently used at the focal plane of gamma-ray telescopes in order to reduce the size of the dead area caused by the geometries of the photodetectors, as well as to reduce the amount of stray light entering at large field angles. The focal plane of the large-sized telescopes (LSTs) of the Cherenkov Telescope Array (CTA) will also be covered by hexagonal light concentrators with an entrance diameter of 50 mm (side to side) to maximize the active area and the photon collection efficiency, enabling realization of a very low energy threshold of 20 GeV. We have developed a prototype of this LST light concentrator with an injection-molded plastic cone and a specular multilayer film. The shape of the plastic cone has been optimized with a cubic B\\'{e}zier curve and a ray-tracing simulation. We have also developed a multilayer film with very high reflectance ($\\gtrsim95$\\%) along wide wavelength and angle coverage. The current status of th...

  1. Thermal Stresses and Cracks During the Growth of Large-sized Sapphire with SAPMAC Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The finite-element method has been used to study the thermal stress distribution in large-sized sapphire crystals grown with the sapphire growth technique with micro-pulling and shoulder-expanding at cooled center (SAPMAC) method. A critical defect model has been established to explain the growth and propagation of cracks during the sapphire growing process. It is demonstrated that the stress field depends on the growth rate, the ambient temperature and the crystallizing direction. High stresses always exist near the growth interfaces, at the shoulder-expanding locations, the tailing locations and the sites where the diameters undergo sharp changes. The maximum stresses always occur at the interface of seeds and crystals. Cracks often form in the critical defect region and spread in the m-planes and a-planes under applied tensile stresses during crystal growth. The experimental results have verified that with the improved system of crystal growth and well-controlled techniques, the large-sized sapphire crystals of high quality can be grown due to absence of cracks.

  2. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Science.gov (United States)

    2010-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  3. The Implication of Large Class Size in the Teaching and Learning of Business Education in Tertiary Institution in Ekiti State

    Science.gov (United States)

    Ayeni, Olapade Grace; Olowe, Modupe Oluwatoyin

    2016-01-01

    Large class size is one of the problems in the educational sector that developing nations have been grappling with. Nigeria as a developing nation is no exception. The purpose of this study is to provide views of both lecturers and students on large class size and how it affects teaching and learning in tertiary institutions in Ekiti State of…

  4. Measurements of 222Rn and 220Rn with a Large Size Collector of Radon Progeny

    Institute of Scientific and Technical Information of China (English)

    Wu Qifan; Jia Wenyi; Fang Fang; Wang Jun; Cheng Jianping; Liu Guilin; Zhu Li

    2003-01-01

    Radon concentrations in high background radiation areas in the south are higher than those of others in China, especially 220Rn concentration is significantly high. Therefore, measurements of 222Rn and 220 Rn concentrations should be carried out there. This paper introduces a large size collector of radon progeny and its applications. The collector is a sheet of polyvinyl chloride fiber with electrostatics of (-500 V) - ( -700 V). Its size (60 mm in diameter) is larger than those of others (26 mm in diameter) that work with the same principle. The collector is more effective to adsorb radon progeny than most of others. The equipment of ZnS(Ag) Scintillation Counting System is available for large size collectors to detect radon progeny. Therefore, its sensitivity of measurement is higher than that of others.According to the different half lives of radon progeny, and based on both theory and experiments, a formula for discrimination and calculation of 222 Rn and 220Rn concentrations is deduced. The 222Rn and 220Rn concentrations were surveyed with electrostatic collectors of radon progeny on the campus of com-mercial school and some other areas in Hainan, southern China. Neither 222Rn nor 220Rn concentration was found significantly high. However, several faults underground were delineated. The collector is also used to study radon transportation. Results indicate that radon changes regularly with date when it has transported for a certain distance. Velocities of radon migration in the four media are quite different.Radon migrates more quickly in vertical tube than in the horizontal tube.

  5. Synthesis of Large-Sized Single-Crystal Hexagonal Boron Nitride Domains on Nickel Foils by Ion Beam Sputtering Deposition.

    Science.gov (United States)

    Wang, Haolin; Zhang, Xingwang; Liu, Heng; Yin, Zhigang; Meng, Junhua; Xia, Jing; Meng, Xiang-Min; Wu, Jinliang; You, Jingbi

    2015-12-22

    Large-sized single-crystal h-BN domains with a lateral size up to 100 μm are synthesized on Ni foils by ion-beam sputtering deposition. The nucleation density of h-BN is dramatically decreased by reducing the concentrations of both active sites and species on the Ni surface through a brief in situ pretreatment of the substrate and optimization of the growth parameters, enabling the growth of large-sized domains.

  6. —Does Demand Fall When Customers Perceive That Prices Are Unfair? The Case of Premium Pricing for Large Sizes

    OpenAIRE

    Eric T. Anderson; Duncan I. Simester

    2008-01-01

    We analyze a large-scale field test conducted with a mail-order catalog firm to investigate how customers react to premium prices for larger sizes of women's apparel. We find that customers who demand large sizes react unfavorably to paying a higher price than customers for small sizes. Further investigation suggests that these consumers perceive that the price premium is unfair. Overall, premium pricing led to a 6% to 8% decrease in gross profits.

  7. Are large farms more efficient? Tenure security, farm size and farm efficiency: evidence from northeast China

    Science.gov (United States)

    Zhou, Yuepeng; Ma, Xianlei; Shi, Xiaoping

    2017-04-01

    How to increase production efficiency, guarantee grain security, and increase farmers' income using the limited farmland is a great challenge that China is facing. Although theory predicts that secure property rights and moderate scale management of farmland can increase land productivity, reduce farm-related costs, and raise farmer's income, empirical studies on the size and magnitude of these effects are scarce. A number of studies have examined the impacts of land tenure or farm size on productivity or efficiency, respectively. There are also a few studies linking farm size, land tenure and efficiency together. However, to our best knowledge, there are no studies considering tenure security and farm efficiency together for different farm scales in China. In addition, there is little study analyzing the profit frontier. In this study, we particularly focus on the impacts of land tenure security and farm size on farm profit efficiency, using farm level data collected from 23 villages, 811 households in Liaoning in 2015. 7 different farm scales have been identified to further represent small farms, median farms, moderate-scale farms, and large farms. Technical efficiency is analyzed with stochastic frontier production function. The profit efficiency is regressed on a set of explanatory variables which includes farm size dummies, land tenure security indexes, and household characteristics. We found that: 1) The technical efficiency scores for production efficiency (average score = 0.998) indicate that it is already very close to the production frontier, and thus there is little room to improve production efficiency. However, there is larger space to raise profit efficiency (average score = 0.768) by investing more on farm size expansion, seed, hired labor, pesticide, and irrigation. 2) Farms between 50-80 mu are most efficient from the viewpoint of profit efficiency. The so-called moderate-scale farms (100-150 mu) according to the governmental guideline show no

  8. Myocardial infarct size and mortality depend on the time of day-a large multicenter study.

    Directory of Open Access Journals (Sweden)

    Stephane Fournier

    Full Text Available Different studies have shown circadian variation of ischemic burden among patients with ST-Elevation Myocardial Infarction (STEMI, but with controversial results. The aim of this study was to analyze circadian variation of myocardial infarction size and in-hospital mortality in a large multicenter registry.This retrospective, registry-based study was based on data from AMIS Plus, a large multicenter Swiss registry of patients who suffered myocardial infarction between 1999 and 2013. Peak creatine kinase (CK was used as a proxy measure for myocardial infarction size. Associations between peak CK, in-hospital mortality, and the time of day at symptom onset were modelled using polynomial-harmonic regression methods.6,223 STEMI patients were admitted to 82 acute-care hospitals in Switzerland and treated with primary angioplasty within six hours of symptom onset. Only the 24-hour harmonic was significantly associated with peak CK (p = 0.0001. The maximum average peak CK value (2,315 U/L was for patients with symptom onset at 23:00, whereas the minimum average (2,017 U/L was for onset at 11:00. The amplitude of variation was 298 U/L. In addition, no correlation was observed between ischemic time and circadian peak CK variation. Of the 6,223 patients, 223 (3.58% died during index hospitalization. Remarkably, only the 24-hour harmonic was significantly associated with in-hospital mortality. The risk of death from STEMI was highest for patients with symptom onset at 00:00 and lowest for those with onset at 12:00.As a part of this first large study of STEMI patients treated with primary angioplasty in Swiss hospitals, investigations confirmed a circadian pattern to both peak CK and in-hospital mortality which were independent of total ischemic time. Accordingly, this study proposes that symptom onset time be incorporated as a prognosis factor in patients with myocardial infarction.

  9. A large size ion beam figuring system for 1.2m astronomical telescopes fabrication

    Science.gov (United States)

    Xie, Xuhui; Yang, Bing; Zhou, Lin; Song, Ci; Hu, Hao

    2016-07-01

    An ion beam figuring system (KDIBF2000) for final figuring of large size optics has been designed and built by National University of Defense Technology in China. It can figure optics up to the maximum dimensions of 2.0m×2.0m×0.4m with five axes of servo-motion used to control ion source movement. For operational facility, there are two vacuum chambers with main work chamber and a small supplementary chamber isolated by a flapper valve. The main chamber has two work zones, which can meantime hold a large optics with Φ1.5m and a small optics with 0.4m. The small optics can be transferred through supplementary chamber with a moving vehicle. By this way, it is very convenient and economical to gain the material removal function and check the system's process performance. Now, this system has been gone into running to figure large SiC off-axis aspheric optics. Next step, a 1.2m SiC aspheric primary mirror will be figure by this system.

  10. Science Case and Requirements for the MOSAIC Concept for a Multi-Object Spectrograph for the European Extremely Large Telescope

    CERN Document Server

    Evans, C J; Barbuy, B; Bonifacio, P; Cuby, J -G; Guenther, E; Hammer, F; Jagourel, P; Kaper, L; Morris, S L; Afonso, J; Amram, P; Aussel, H; Basden, A; Bastian, N; Battaglia, G; Biller, B; Bouché, N; Caffau, E; Charlot, S; Clenet, Y; Combes, F; Conselice, C; Contini, T; Dalton, G; Davies, B; Disseau, K; Dunlop, J; Fiore, F; Flores, H; Fusco, T; Gadotti, D; Gallazzi, A; Giallongo, E; Gonçalves, T; Gratadour, D; Hill, V; Huertas-Company, M; Ibata, R; Larsen, S; Fèvre, O Le; Lemasle, B; Maraston, C; Mei, S; Mellier, Y; Östlin, G; Paumard, T; Pello, R; Pentericci, L; Petitjean, P; Roth, M; Rouan, D; Schaerer, D; Telles, E; Trager, S; Welikala, N; Zibetti, S; Ziegler, B

    2014-01-01

    Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input from a broad cross-section of astronomers across the ESO partner countries. In this contribution we summarise the key cases relating to studies of high-redshift galaxies, galaxy evolution, and stellar populations, with a more expansive presentation of a new case relating to detection of exoplanets in stellar clusters. A general requirement is the need for two observational modes to best exploit the large (>40 sq. arcmin) patrol field of the E-ELT. The first mode ('high multiplex') requires integrated-light (or coarsely resolved) optical/near-IR spectroscopy of >100 objects simultaneously. The second ('high definition'), enabled by wide-field adaptive optics, requires spatially-resolved, near-IR of >10 objects/sub-fields. Within the context of the conceptual study for an ELT-MOS called MO...

  11. Transient response in longitudinal grain size to reduced sediment supply in a large river

    Science.gov (United States)

    Singer, Michael

    2010-05-01

    Bed material grain size is an important degree of freedom in fluvial systems as they adjust to system-wide perturbations such as sediment supply changes. However, little is known about processes and patterns of such adjustment in longitudinal grain size sorting in large rivers. This research uses unprecedented datasets collected in a large fluvial system to investigate transient response to recent supply changes associated with anthropogenic activities. Separate fining trends for gravel and fines, a protracted gravel-sand (G-S) transition, and bed patchiness identified in Singer (2008) were interrogated using output from a hydraulic model with grain size distributions (GSDs) extracted from ~125 cross sections spanning ~400 river kilometers of the Sacramento River, California. The analysis suggests that interactions between hydraulics, bed material sorting, and sediment flux explain these previously identified anomalies. Highest values of sorting occur in the G-S transition and represent the overlap of separate fining trends for gravel and fines, where the long profile is jagged with evidence of progressive incision. Much of the sediment in this poorly sorted zone is organized into patches, where transport apparently occurs as bedload sheets. Patchiness occurs over short length scales leading to strong differences in entrainment and flux, regardless of hydraulic conditions. A modified Shields stress is proposed that is scaled by GSD sorting to improve characterization of entrainment/disentrainment. Sediment flux calculations based on an equation sensitive bed material conditions (Singer and Dunne, 2004) reveal a strong relationship between fine sediment flux and d90, suggesting that the efficiency of fine patch flux controls bed material bed surface roughness. Results are in part consistent with Paola and Seal (1995) suggesting that patches are a result of overlapping pdfs of shear stress and sorting and with Ferguson (2003) in that the final end of the protracted G

  12. The Friction Force Determination of Large-Sized Composite Rods in Pultrusion

    Science.gov (United States)

    Grigoriev, S. N.; Krasnovskii, A. N.; Kazakov, I. A.

    2014-08-01

    Nowadays, the simple pull-force models of pultrusion process are not suitable for large sized rods because they are not considered a chemical shrinkage and thermal expansion acting in cured material inside the die. But the pulling force of the resin-impregnated fibers as they travels through the heated die is essential factor in the pultrusion process. In order to minimize the number of trial-and-error experiments a new mathematical approach to determine the frictional force is presented. The governing equations of the model are stated in general terms and various simplifications are implemented in order to obtain solutions without extensive numerical efforts. The influence of different pultrusion parameters on the frictional force value is investigated. The results obtained by the model can establish a foundation by which process control parameters are selected to achieve an appropriate pull-force and can be used for optimization pultrusion process.

  13. Simulation of the main physical processes in remote laser penetration with large laser spot size

    Directory of Open Access Journals (Sweden)

    S. A. Khairallah

    2015-04-01

    Full Text Available A 3D model is developed to simulate remote laser penetration of a 1mm Aluminum metal sheet with large laser spot size (∼ 3x3cm2, using the ALE3D multi-physics code. The model deals with the laser-induced melting of the plate and the mechanical interaction between the solid and the melted part through plate elastic-plastic response. The effect of plate oscillations and other forces on plate rupture, the droplet formation mechanism and the influence of gravity and high laser power in further breaking the single melt droplet into many more fragments are analyzed. In the limit of low laser power, the numerical results match the available experiments. The numerical approach couples mechanical and thermal diffusion to hydrodynamics melt flow and accounts for temperature dependent material properties, surface tension, gravity and vapor recoil pressure.

  14. Comparative analysis on technologies between Chinese and American large-sized oil companies based on patentometrics

    Directory of Open Access Journals (Sweden)

    Zhao Qu

    2014-01-01

    Full Text Available Patent information is critical and important object to reflect differences in technology capacity; the paper makes statistical analysis on structural elements of five large-sized oil companies from America and China as collected in Derwent Innovations Index, and compare technical similarities and differences between such companies′ patents with visualization tools, by further research on academic classes, Derwent Class Code and co-occurrence of Manual Code. It is shown from the researches that Chinese enterprises is advantaged in growth in number of patents and cooperation rate, but their patents are characterized by poor influence, less relevance and connection between various disciplines, as well as relatively backward development of patented technology. Finally, according to current status of patents of Chinese and American oil companies, the paper proposes a series of recommendations and countermeasures for improvement in patents quality and future expansion in patented technology by Chinese oil companies.

  15. Surface plasmon resonance biosensor based on large size square-lattice photonic crystal fiber

    Science.gov (United States)

    Bing, Pibin; Li, Zhongyang; Yuan, Sheng; Yao, Jianquan; Lu, Ying

    2016-04-01

    A surface plasmon resonance biosensor based on large size square-lattice photonic crystal fiber has been designed and simulated by finite element method. The square-lattice airholes are first coated with a calcium fluoride layer to provide mode confinement, then a nanoscale gold layer is deposited to excite the plasmon mode, and finally, the sample is infiltrated into the holes. The numerical results reveal that the resonance properties are easily affected by many parameters. The refractive index resolution of corresponding sensor can reach 4.3 × 10-6 RIU when the optimum parameters are set as the radius of curvature of the airhole r = 2 μm, the thickness of the core struts c = 200 nm, the auxiliary dielectric layer s = 1 μm, and the gold film d = 40 nm. In addition, the effective area and nonlinear coefficient are calculated.

  16. Preparation of ceria with large particle size and high appearance density

    Institute of Scientific and Technical Information of China (English)

    WANG Songling; LIU Junyun; JIA Jiangtao; LIAO Chunsheng; YAN Chunhua

    2008-01-01

    Cerium is one of the most abundant rare earth dements in both bastnasite and monazite. Ceria has been widely used in optical catalytic, electrolyte, and sensor materials, with unique performances. With the development of functional materials, great interest has been focused on the synthesis and characterization of specific fine/mesoporous ceria powder. In this study, the modified precipitation and recrystallization processes combined with a controlled calcination process for fabricating the ceria with large particle size and high appearance density was reported. During precipitation, a certain amount of mineral acid such as nitric acid served as an additive, to adjust the precipitation and crystallization processes of cerium oxalates. An appropriate acidic condition could lead the process into the Oswald ripening stage and made the particles become bigger. Thus, the appearance density of powder was increased. The optimized conditions, such as the temperature, feeding speed, type and concentration of mineral acids, and the concentration of cerium-contained stock solution, were investigated and evaluated.

  17. A maturity model for SCPMS project-an empirical investigation in large sized Moroccan companies

    Directory of Open Access Journals (Sweden)

    Chafik Okar

    2011-03-01

    Full Text Available In the recent years many studies on maturity model have been carried out. Some refer specifically to maturity models for supply chain and performance measurement system. Starting from an analysis of the existing literature, the aim of this paper is to develop a maturity model for the supply chain performance measurement system (SCPMS project based on the concept of critical success factors (CSFs. This model will be validated by two approaches. The first is a pilot test of the model in a Moroccan supply chain to demonstrate his capacity of assessing the maturity of SCPMS project and whether it can develop an improvement roadmap. The second is an empirical investigation in large sized Moroccan companies by using a survey to depict whether it can evaluate the maturity of SCPMS project in different industries.

  18. Preform design of large sized profile ring rolling using main roll

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. J. [PSM Inc., Busan (Korea, Republic of); Kang, J. H. [Jac coupling, Busan (Korea, Republic of); Kang, S. S. [Busan Nat' l Univ., Busan (Korea, Republic of)

    2014-01-15

    This paper introduces a preform design method for a ring rolling process with an outer step. Underfilling is one of the general defects of the profile ring rolling process. It occurs when the deformation amount is small or step depth of the profiled region is large. To prevent underfilling, increasing the deformation amount or using a preform of size similar to that of the final product are required. Furthermore, the filling limit equation is suggested based on the shape factor and deformation ratio for preventing defects in the products. The filling limit equation has been derived through finite element analyses and production tests for four different cases. For verifying the suggested method, realsized profile rolling tests were performed, and test results were compared with the predictions of the equation.

  19. Oestrogen receptor genotypes and litter size in Hungarian Large White pigs.

    Science.gov (United States)

    Horogh, G; Zsolnai, A; Komiósi, I; Nyíri, A; Anton, I; Fésüs, L

    2005-02-01

    A total of 869 litter records of 226 Hungarian Large White sows have been analysed to investigate the possible use of the oestrogen receptor gene (ESR) as marker to improve litter size. First, second and later parities have been evaluated separately. Frequencies of A = 0.55 and B = 0.45 have been calculated for the two ESR alleles and the observed/ expected number of the three genotypes were as follows: AA: 71/69.1, AB: 108/111.8 and BB: 47/45.1. BB type first and later parity sows were superior to AB and AA sows for number born alive (NBA), total number of born (TNB) and the corrected number of weaned piglets (CNW), respectively.

  20. Asymmetric dihedral angle offsets for large-size lunar laser ranging retroreflectors

    Science.gov (United States)

    Otsubo, Toshimichi; Kunimori, Hiroo; Noda, Hirotomo; Hanada, Hideo; Araki, Hiroshi; Katayama, Masato

    2011-08-01

    The distribution of two-dimensional velocity aberration is off-centered by 5 to 6 microradians in lunar laser ranging, due to the stable measurement geometry in the motion of the Earth and the Moon. The optical responses of hollow-type retroreflectors are investigated through numerical simulations, especially focusing on large-size, single-reflector targets that can ultimately minimize the systematic error in future lunar laser ranging. An asymmetric dihedral angle offset, i.e. setting unequal angles between the three back faces, is found to be effective for retroreflectors that are larger than 100 mm in diameter. Our numerical simulation results reveal that the optimized return energy increases approximately 3.5 times more than symmetric dihedral angle cases, and the optimized dihedral angle offsets are 0.65-0.8 arcseconds for one angle, and zeroes for the other two angles.

  1. BASIC HYDRODYNAMICS CHARACTERISTICS OF CAVITY SPIRAL FLOW IN A LARGE SIZE LEVEL PIPE

    Institute of Scientific and Technical Information of China (English)

    NIU Zheng-ming; ZHANG Ming-yuan

    2005-01-01

    Based on the observation of a model test and in combination with some theoretical analysis, the researches of some basic hydrodynamics characteristics of cavity spiral flow in a large size level pipe with a shaft-inlet is presented in the paper, which include the basic flow pattern, formation condition of the cavity spiral flow, discharge Q, cavity diameter d0, wall pressure coefficient Cpw, velocity distribution, total energy dissipation rate η etc. The results show that the basic flow patterns can be divided into three zones according to the variations in cavity spiral flow when the upstream and downstream water level changes and that the basic hydrodynamics characteristics change with the flow pattern and have the different behaviour.

  2. A Ternary Solvent Method for Large-Sized Two-Dimensional Perovskites.

    Science.gov (United States)

    Chen, Junnian; Gan, Lin; Zhuge, Fuwei; Li, Huiqiao; Song, Jizhong; Zeng, Haibo; Zhai, Tianyou

    2017-02-20

    Recent reports demonstrate that a two-dimensional (2D) structural characteristic can endow perovskites with both remarkable photoelectric conversion efficiency and high stability, but the synthesis of ultrathin 2D perovskites with large sizes by facile solution methods is still a challenge. Reported herein is the controlled growth of 2D (C4 H9 NH3 )2 PbBr4 perovskites by a chlorobenzene-dimethylformide-acetonitrile ternary solvent method. The critical factors, including solvent volume ratio, crystallization temperature, and solvent polarity on the growth dynamics were systematically studied. Under optimum reaction condition, 2D (C4 H9 NH3 )2 PbBr4 perovskites, with the largest lateral dimension of up to 40 μm and smallest thickness down to a few nanometers, were fabricated. Furthermore, various iodine doped 2D (C4 H9 NH3 )2 PbBrx I4-x perovskites were accessed to tune the optical properties rationally.

  3. Large-scale Hydrothermal Synthesis and Characterization of Size-controlled Lanthanum Hydroxide Nanorods

    Institute of Scientific and Technical Information of China (English)

    YI,Ran; ZHANG,Ning; SHI,Rongrong; LI,Yongbo; QIU Guanzhou; LIU Xiaohe

    2009-01-01

    Uniform lanthanum hydroxide nanorods were successfully synthesized in large quantities through a facile hydrothermal synthetic method, in which soluble lanthanum nitrate was used to supply the lanthanum source and triethylamine (TEA) was used as both alkaline agent and complexing agent. The influences of triethylamine amount, surfactant, reaction temperature and time on the size and shape of lanthanum hydroxide nanorods were investigated in detail. Trivalent rare earth ion doped lanthanum hydroxide nanorods were also obtained in this paper. The phase structures and morphologies of the as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high-resolution transmis-sion electron microscopy (HRTEM). The probable formation mechanism was proposed based on the experimental results.

  4. Larval assemblages of large and medium-sized pelagic species in the Straits of Florida

    Science.gov (United States)

    Richardson, David E.; Llopiz, Joel K.; Guigand, Cedric M.; Cowen, Robert K.

    2010-07-01

    Critical gaps in our understanding of the distributions, interactions, life histories and preferred habitats of large and medium-size pelagic fishes severely constrain the implementation of ecosystem-based, spatially structured fisheries management approaches. In particular, spawning distributions and the environmental characteristics associated with the early life stages are poorly documented. In this study, we consider the diversity, assemblages, and associated habitat of the larvae of large and medium-sized pelagic species collected during 2 years of monthly surveys across the Straits of Florida. In total, 36 taxa and 14,295 individuals were collected, with the highest diversity occurring during the summer and in the western, frontal region of the Florida Current. Only a few species (e.g. Thunnus obesus, T. alalunga, Tetrapturus pfluegeri) considered for this study were absent. Small scombrids (e.g. T. atlanticus, Katsuwonus pelamis, Auxis spp.) and gempylids dominated the catch and were orders of magnitude more abundant than many of the rare species (e.g. Thunnus thynnus,Kajikia albida). Both constrained (CCA) and unconstrained (NMDS) multivariate analyses revealed a number of species groupings including: (1) a summer Florida edge assemblage (e.g. Auxis spp., Euthynnus alleterattus, Istiophorus platypterus); (2) a summer offshore assemblage (e.g. Makaira nigricans, T. atlanticus, Ruvettus pretiosus, Lampris guttatus); (3) an ubiquitous assemblage (e.g. K. pelamis, Coryphaena hippurus, Xiphias gladius); and (4) a spring/winter assemblage that was widely dispersed in space (e.g. trachipterids). The primary environmental factors associated with these assemblages were sea-surface temperature (highest in summer-early fall), day length (highest in early summer), thermocline depth (shallowest on the Florida side) and fluorescence (highest on the Florida side). Overall, the results of this study provide insights into how a remarkable diversity of pelagic species

  5. Heritabilities and genetic and phenotypic correlations of litter uniformity and litter size in Large White sows

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tian; ZHAO Ke-bin; WANG Li-xian; WANG Li-gang; SHI Hui-bi; YAN Hua; ZHANG Long-chao; LIU Xin; PU Lei; LIANG Jing; ZHANG Yue-bo

    2016-01-01

    Litter uniformity, which is usualy represented by within-litter weight coefifcient of variation at birth (CVB), could inlfuence litter performance of sows and the proiftability of pig enterprises. The objective of this study was to characterize CVB and its effect on other reproductive traits in Large White sows. Genetic parameters and genetic correlation of the reproductive traits, including CVB, within-litter weight coefifcient of variation at three weeks (CVT), total number born (TNB), number born alive (NBA), number born dead (NBD), gestation length (GL), piglet mortality at birth (M0), piglet mortality at three weeks (M3), total litter weight at birth (TLW0), and total litter weight at three weeks (TLW3) were estimated for 2032 Large White litters. The effects of parity and classiifed litter size on CVB, CVT, TNB, NBA, NBD, GL, M0, M3, TLW0, and TLW3 were also estimated. The heritabilities of these reproductive traits ranged from 0.06 to 0.17, with the lowest heritability for CVB and the highest heritability for TLW0. Phenotypic and genetic correlations between these reproductive traits were low to highly positive and negative (ranging from −0.03 to 0.93, and −0.53 to 0.93, respectively). The genetic correlations between TNB and CVB, and between M0 and CVB were 0.32 and 0.29, respectively. In addition, CVB was signiifcantly inlfuenced by parity and litter size class (P<0.05). Al the results suggest that piglet uniformity should be maintained in pig production practices and pig breeding programs.

  6. Large apparent electric size of solid-state nanopores due to spatially extended surface conduction.

    Science.gov (United States)

    Lee, Choongyeop; Joly, Laurent; Siria, Alessandro; Biance, Anne-Laure; Fulcrand, Rémy; Bocquet, Lydéric

    2012-08-08

    Ion transport through nanopores drilled in thin membranes is central to numerous applications, including biosensing and ion selective membranes. This paper reports experiments, numerical calculations, and theoretical predictions demonstrating an unexpectedly large ionic conduction in solid-state nanopores, taking its origin in anomalous entrance effects. In contrast to naive expectations based on analogies with electric circuits, the surface conductance inside the nanopore is shown to perturb the three-dimensional electric current streamlines far outside the nanopore in order to meet charge conservation at the pore entrance. This unexpected contribution to the ionic conductance can be interpreted in terms of an apparent electric size of the solid-state nanopore, which is much larger than its geometric counterpart whenever the number of charges carried by the nanopore surface exceeds its bulk counterpart. This apparent electric size, which can reach hundreds of nanometers, can have a major impact on the electrical detection of translocation events through nanopores, as well as for ionic transport in biological nanopores.

  7. Large 2D-arrays of size-controllable silver nanoparticles prepared by hybrid deposition

    Science.gov (United States)

    Dieu Thuy Ung, Thi; Hoa Nguyen, Thi; Liem Nguyen, Quang

    2016-09-01

    Two main results are presented in this paper. (i) Silver nanoparticles (AgNPs) with uniform size-distribution and controllability in the range of 20-50 nm were synthesized by seeding and growing at ambient conditions. The single-crystal Ag nano-seeds were created by reduction of AgNO3 in presence of citrate surfactant at 70 °C. Then, importantly, the fresh AgCl precursor was used in the presence of polyvinylpyrrolidone to adjust the reaction rate with ascorbic acid to generate Ag for growing on the surface of single-crystal Ag nano-seeds. The AgNPs size could be well-controlled by varying the amount of Ag nano-seeds while keeping the AgCl precursor concentration to be constant. (ii) The large 2D-arrays with homogeneous and dense monolayers of AgNPs were prepared on ITO substrates by hybrid method, in which the key technological point is the surface functionalization of AgNPs using mixed alkanethiols (dodecanethiol:octadecanethiol = 6:1). We have used the fabricated 2D-arrays from the 50 nm AgNPs as a surface enhanced Raman scattering substrate to take the Raman scattering spectra of rhodamine B (RhB), glucose and viral pathogen (H5N1) at very low concentrations of 10-10 M, 10-12 M and 4 ng μl-1, respectively.

  8. STATUS REPORT ON THE CMS FORWARD MUON UPGRADE WITH LARGE-SIZE TRIPLE-GEM DETECTORS

    CERN Document Server

    Barria, Patrizia

    2014-01-01

    For the LHC High Luminosity phase (HL-LHC) the CMS GEM Collaboration is planning to install new large size (990 x 440-220 mm2) triple-GEM detectors, equipped with a new readout system, in the forward region of the muon system (1.5 lt IηI lt 2.2) of the CMS detector. Combining triggering and tracking functionalities the new triple-Gas Electron Multiplier (GEM) chambers will not only improve the performance of the CMS muon trigger, but will also improve the muon identification and track reconstruction. With the addition of triple-GEM detectors the forward region of the CMS muon spectrometer will recover its originally planned redundancy. Starting from 2009 the CMS GEM Collaboration built several small and full size prototypes with different geometries, keeping improving the assembly techniques. All these prototypes have been tested in laboratories as well as with beam tests at the CERN SPS and at Fermilab. The results show that the triple-GEM detectors are a mature technology satisfying all the requirements ...

  9. Genome-wide patterns of large-size presence/absence variants in sorghum

    Institute of Scientific and Technical Information of China (English)

    LiMin Zhang; Hong Luo; ZhiQuan Liu; Yi Zhao; JingChu Luo; DongYun Hao; HaiChun Jing

    2014-01-01

    The presence/absence variants (PAVs) are a major source of genome structural variation and have profound effects on phenotypic and genomic variation in animals and humans. However, little is understood about PAVs in plant genomes. Our previous resequencing effort on three sorghum (Sorghum bicolour L.) genomes, each 12? coverage, uncovered 5 364 PAVs. Here, we report a detailed characterization of 51 large-size (>30 kb) PAVs. These PAVs spanned a total size of 2.92 Mb of the sorghum genome containing 202 known and predicted genes, including 38 genes annotated to encode celldeath and stress response genes. The PAVs varied considerably for repeat sequences and mobile elements with DNA trans-posons as the major components. The frequency and distribution of these PAVs differed substantial y across 96 sorghum inbred lines, and the low-and high frequency PAVs differed in their gene categories. This report shed new light on the occurrence and diversity of PAVs in sorghum genomes. Our research exemplifies a new perspective to explore genome structural variation for genetic improvement in plant breeding.

  10. Mie scattering by ensembles of particles with very large size parameters

    Science.gov (United States)

    Wolf, S.; Voshchinnikov, N. V.

    2004-09-01

    We present a computer program for the simulation of Mie scattering in case of arbitrarily large size parameters. The elements of the scattering matrix, efficiency factors as well as the corresponding cross-sections, the albedo and the scattering asymmetry parameter are calculated. Single particles as well as particle ensembles consisting of several components and particle size distributions can be considered. Program summary Title of program: miex Catalogue identifier: ADUD Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADUD Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer for which the program is designed and others on which it has been tested: Computers: Any machine running standard FORTRAN 90; miex has been tested on an Intel Celeron processor (Redhat Linux 9.0, Intel Fortran Compiler 7.1), an Intel XEON processor (SuSE Linux 9.0, Intel Fortran Compiler 8.0), and a Sun-Blade-1000 (OS 8.5, Sun Workshop Compiler Fortran 90 2.0). Installations: standard Operating systems or monitors under which the program has been tested: Redhat Linux 9.0, SuSE Linux 9.0, Sun OS 8.5 Programming language used: Fortran 90 Memory required to execute with typical data: 1 MByte - several 100 MByte (see Appendix A for examples) No. of bits in a word: 8 No. of processors used: 1 Has the code been vectorized or parallelized?: No No. of lines in distributed program, including test data, etc.: 78238 No. of bytes in distributed program, including test data, etc.: 1015805 Distributed format: tar.gz Nature of the physical problem: Among a variety of applications, Mie scattering is of essential importance for the continuum radiative transfer in cosmic dust configurations. In this particular case, Mie theory describes the interaction of electromagnetic radiation with spherical dust grains on the basis of their complex refractive index and size parameter. Both, broad grain size distributions (radii a: nanometers-millimeters) and a very wide

  11. Physicochemical characterization of smoke aerosol during large-scale wildfires: Extreme event of August 2010 in Moscow

    Science.gov (United States)

    Popovicheva, O.; Kistler, M.; Kireeva, E.; Persiantseva, N.; Timofeev, M.; Kopeikin, V.; Kasper-Giebl, A.

    2014-10-01

    Enhancement of biomass burning-related research is essential for the assessment of large-scale wildfires impact on pollution at regional and global scale. Starting since 6 August 2010 Moscow was covered with thick smoke of unusually high PM10 and BC concentrations, considerably affected by huge forest and peat fires around megacity. This work presents the first comprehensive physico-chemical characterization of aerosols during extreme smoke event in Moscow in August 2010. Sampling was performed in the Moscow center and suburb as well as one year later, in August 2011 during a period when no biomass burning was observed. Small-scale experimental fires of regional biomass were conducted in the Moscow region. Carbon content, functionalities of organic/inorganic compounds, tracers of biomass burning (anhydrosaccharides), ionic composition, and structure of smoke were analyzed by thermal-optical analysis, FTIR spectroscopy, liquid and ion chromatography, and electron microscopy. Carbonaceous aerosol in August 2010 was dominated by organic species with elemental carbon (EC) as minor component. High average OC/EC near 27.4 is found, comparable to smoke of regional biomass smoldering fire, and exceeded 3 times the value observed in August 2011. Organic functionalities of Moscow smoke aerosols were hydroxyl, aliphatic, aromatic, acid and non-acid carbonyl, and nitro compound groups, almost all of them indicate wildfires around city as the source of smoke. The ratio of levoglucosan (LG) to mannosan near 5 confirms the origin of smoke from coniferous forest fires around megacity. Low ratio of LG/OC near 0.8% indicates the degradation of major molecular tracer of biomass burning in urban environment. Total concentration of inorganic ions dominated by sulfates SO2- and ammonium NH was found about 5 times higher during large-scale wildfires than in August 2011. Together with strong sulfate and ammonium absorbance in smoke aerosols, these observations prove the formation of

  12. Characteristics measurement methodology of the large-size autostereoscopic 3D LED display

    Science.gov (United States)

    An, Pengli; Su, Ping; Zhang, Changjie; Cao, Cong; Ma, Jianshe; Cao, Liangcai; Jin, Guofan

    2014-11-01

    Large-size autostereoscopic 3D LED displays are commonly used in outdoor or large indoor space, and have the properties of long viewing distance and relatively low light intensity at the viewing distance. The instruments used to measure the characteristics (crosstalk, inconsistency, chromatic dispersion, etc.) of the displays should have long working distance and high sensitivity. In this paper, we propose a methodology for characteristics measurement based on a distribution photometer with a working distance of 5.76m and the illumination sensitivity of 0.001 mlx. A display panel holder is fabricated and attached on the turning stage of the distribution photometer. Specific test images are loaded on the display separately, and the luminance data at the distance of 5.76m to the panel are measured. Then the data are transformed into the light intensity at the optimum viewing distance. According to definitions of the characteristics of the 3D displays, the crosstalk, inconsistency, chromatic dispersion could be calculated. The test results and analysis of the characteristics of an autostereoscopic 3D LED display are proposed.

  13. Use of telemetry X-ray techniques in large-size pictorial works

    Directory of Open Access Journals (Sweden)

    Jose Antonio Madrid Garcia

    2013-12-01

    Full Text Available In recent years, with the rise of digital technologies and the concurrent demise of related analog instrumentation, researchers in the field of cultural heritage have faced significant new challenges implementing digital solutions. Specifically, this shift has prompted the use of new protocols for the application of radiology in the study of art works.. However, due to this change, there has been a return to using older film formats, which is one of the problems that has already been solved using an industrial-type analogical system that allowed large-format X-ray support, and that was able to adapt to almost any surface. Therefore, this study attempts to rectify the limits of digital X-ray techniques by using telemetry X-ray techniques. At the Laboratory of Documentation and Registration (IRP, or Institute for the Heritage Restoration, based at the Universitat Politècnica de Valencia (UPV, Spain, mobile telemetry X-ray equipment has been designed and implemented that allows the adaptation of large-size pictorial works.

  14. The limits of weak selection and large population size in evolutionary game theory.

    Science.gov (United States)

    Sample, Christine; Allen, Benjamin

    2017-03-28

    Evolutionary game theory is a mathematical approach to studying how social behaviors evolve. In many recent works, evolutionary competition between strategies is modeled as a stochastic process in a finite population. In this context, two limits are both mathematically convenient and biologically relevant: weak selection and large population size. These limits can be combined in different ways, leading to potentially different results. We consider two orderings: the [Formula: see text] limit, in which weak selection is applied before the large population limit, and the [Formula: see text] limit, in which the order is reversed. Formal mathematical definitions of the [Formula: see text] and [Formula: see text] limits are provided. Applying these definitions to the Moran process of evolutionary game theory, we obtain asymptotic expressions for fixation probability and conditions for success in these limits. We find that the asymptotic expressions for fixation probability, and the conditions for a strategy to be favored over a neutral mutation, are different in the [Formula: see text] and [Formula: see text] limits. However, the ordering of limits does not affect the conditions for one strategy to be favored over another.

  15. INNOVATIVE TECHNIQUES AND TECHNOLOGY APPLICATION IN MANAGEMENT OF REMOTE HANDLED AND LARGE SIZED MIXED WASTE FORMS

    Energy Technology Data Exchange (ETDEWEB)

    BLACKFORD LT

    2008-02-04

    CH2M HILL Hanford Group, Inc. (CH2M HILL) plays a critical role in Hanford Site cleanup for the U. S. Department of Energy, Office of River Protection (ORP). CH2M HILL is responsible for the management of 177 tanks containing 53 million gallons of highly radioactive wastes generated from weapons production activities from 1943 through 1990. In that time, 149 single-shell tanks, ranging in capacity from 50,000 gallons to 500,000 gallons, and 28 double-shell tanks with a capacity of 1 million gallons each, were constructed and filled with toxic liquid wastes and sludges. The cleanup mission includes removing these radioactive waste solids from the single-shell tanks to double-shell tanks for staging as feed to the Waste Treatment Plant (WTP) on the Hanford Site for vitrification of the wastes and disposal on the Hanford Site and Yucca Mountain repository. Concentrated efforts in retrieving residual solid and sludges from the single-shell tanks began in 2003; the first tank retrieved was C-106 in the 200 East Area of the site. The process for retrieval requires installation of modified sluicing systems, vacuum systems, and pumping systems into existing tank risers. Inherent with this process is the removal of existing pumps, thermo-couples, and agitating and monitoring equipment from the tank to be retrieved. Historically, these types of equipment have been extremely difficult to manage from the aspect of radiological dose, size, and weight of the equipment, as well as their attendant operating and support systems such as electrical distribution and control panels, filter systems, and mobile retrieval systems. Significant effort and expense were required to manage this new waste stream and resulted in several events over time that were both determined to be unsafe for workers and potentially unsound for protection of the environment. Over the last four years, processes and systems have been developed that reduce worker exposures to these hazards, eliminate violations

  16. Stellar metallicities beyond the Local Group: the potential of J-band spectroscopy with extremely large telescopes

    CERN Document Server

    Evans, C J; Kudritzki, R -P; Puech, M; Yang, Y; Cuby, J -G; Figer, D F; Lehnert, M D; Morris, S L; Rousset, G

    2010-01-01

    We present simulated J-band spectroscopy of red giants and supergiants with a 42m European Extremely Large Telescope (E-ELT), using tools developed toward the EAGLE Phase A instrument study. The simulated spectra are used to demonstrate the validity of the 1.15-1.22 micron region to recover accurate stellar metallicities from Solar and metal-poor (one tenth Solar) spectral templates. From tests at spectral resolving powers of four and ten thousand, we require continuum signal-to-noise ratios in excess of 50 (per two-pixel resolution element) to recover the input metallicity to within 0.1 dex. We highlight the potential of direct estimates of stellar metallicites (over the range -1<[Fe/H]<0) of red giants with the E-ELT, reaching out to distances of ~5 Mpc for stars near the tip of the red giant branch. The same simulations are also used to illustrate the potential for quantitative spectroscopy of red supergiants beyond the Local Volume to tens of Mpc. Calcium triplet observations in the I-band are also ...

  17. An Extreme Metallicity, Large-Scale Outflow from a Star-Forming Galaxy at z ~ 0.4

    CERN Document Server

    Muzahid, Sowgat; Churchil, Christopher W; Charlton, Jane C; Nielsen, Nikole M; Mathes, Nigel L; Trujillo-Gomez, Sebastian

    2015-01-01

    We present a detailed analysis of a large-scale galactic outflow in the CGM of a massive (M_h ~ 10^12.5 Msun), star-forming (6.9 Msun/yr), sub-L* (0.5 L_B*) galaxy at z=0.39853 that exhibits a wealth of metal-line absorption in the spectra of the background quasar Q 0122-003 at an impact parameter of 163 kpc. The galaxy inclination angle (i=63 degree) and the azimuthal angle (Phi=73 degree) imply that the QSO sightline is passing through the projected minor-axis of the galaxy. The absorption system shows a multiphase, multicomponent structure with ultra-strong, wide velocity spread OVI (logN = 15.16\\pm0.04, V_{90} = 419 km/s) and NV (logN = 14.69\\pm0.07, V_{90} = 285 km/s) lines that are extremely rare in the literature. The highly ionized absorption components are well explained as arising in a low density (10^{-4.2} cm^{-3}), diffuse (10 kpc), cool (10^4 K) photoionized gas with a super-solar metallicity ([X/H] > 0.3). From the observed narrowness of the Lyb profile, the non-detection of SIV absorption, and...

  18. Monte-Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope

    Science.gov (United States)

    Basden, A. G.; Morris, T. J.

    2016-09-01

    The performance of a wide-field adaptive optics system depends on input design parameters. Here we investigate the performance of a multi-object adaptive optics system design for the European Extremely Large Telescope, using an end-to-end Monte-Carlo adaptive optics simulation tool, DASP, with relevance for proposed instruments such as MOSAIC. We consider parameters such as the number of laser guide stars, sodium layer depth, wavefront sensor pixel scale, actuator pitch and natural guide star availability. We provide potential areas where costs savings can be made, and investigate trade-offs between performance and cost, and provide solutions that would enable such an instrument to be built with currently available technology. Our key recommendations include a trade-off for laser guide star wavefront sensor pixel scale of about 0.7 arcseconds per pixel, and a field of view of at least 7 arcseconds, that EMCCD technology should be used for natural guide star wavefront sensors even if reduced frame rate is necessary, and that sky coverage can be improved by a slight reduction in natural guide star sub-aperture count without significantly affecting tomographic performance. We find that adaptive optics correction can be maintained across a wide field of view, up to 7 arcminutes in diameter. We also recommend the use of at least 4 laser guide stars, and include ground-layer and multi-object adaptive optics performance estimates.

  19. Charge compensation in extremely large magnetoresistance materials LaSb and LaBi revealed by first-principles calculations

    Science.gov (United States)

    Guo, Peng-Jie; Yang, Huan-Cheng; Zhang, Bing-Jing; Liu, Kai; Lu, Zhong-Yi

    2016-06-01

    By the first-principles electronic structure calculations, we have systematically studied the electronic structures of recently discovered extremely large magnetoresistance (XMR) materials LaSb and LaBi. We find that both LaSb and LaBi are semimetals with the electron and hole carriers in balance. The calculated carrier densities on the order of 1020cm-3 are in good agreement with the experimental values, implying long mean-free time of carriers at low temperatures and thus high carrier mobilities. With a semiclassical two-band model, the charge compensation and high carrier mobilities naturally explain: (i) the XMR observed in LaSb and LaBi, (ii) the nonsaturating quadratic dependence of XMR on an external magnetic field, and (iii) the resistivity plateau in the turn-on temperature behavior at very low temperatures. The explanation of these features without resorting to the topological effect indicates that they should be the common characteristics of all electron-hole compensated semimetals.

  20. Early Science with the Large Millimeter Telescope: Observations of Extremely Luminous High-z Sources Identified by Planck

    CERN Document Server

    Harrington, K C; Cybulski, R; Wilson, G W; Aretxaga, I; Chavez, M; De la Luz, V; Erickson, N; Ferrusca, D; Gallup, A D; Hughes, D H; Montaña, A; Narayanan, G; Sánchez-Argüelles, D; Schloerb, F P; Souccar, K; Terlevich, E; Terlevich, R; Zeballos, M; Zavala, J A

    2016-01-01

    We present 8.5 arcsec resolution 1.1mm continuum imaging and CO spectroscopic redshift measurements of eight extremely bright submillimetre galaxies identified from the Planck and Herschel surveys, taken with the Large Millimeter Telescope's AzTEC and Redshift Search Receiver instruments. We compiled a candidate list of high redshift galaxies by cross-correlating the Planck Surveyor mission's highest frequency channel (857 GHz, FWHM = 4.5 arcmin) with the archival Herschel Spectral and Photometric Imaging Receiver (SPIRE) imaging data, and requiring the presence of a unique, single Herschel counterpart within the 150 arcsec search radius of the Planck source positions with 350 micron flux density larger than 100 mJy, excluding known blazars and foreground galaxies. All eight candidate objects observed are detected in 1.1mm continuum by AzTEC bolometer camera, and at least one CO line is detected in all cases with a spectroscopic redshift between 1.3 < z(CO) < 3.3. Their infrared spectral energy distribu...

  1. Monte-Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope

    CERN Document Server

    Basden, Alastair

    2016-01-01

    The performance of a wide-field adaptive optics system depends on input design parameters. Here we investigate the performance of a multi-object adaptive optics system design for the European Extremely Large Telescope, using an end-to-end Monte-Carlo adaptive optics simulation tool, DASP, with relevance for proposed instruments such as MOSAIC. We consider parameters such as the number of laser guide stars, sodium layer depth, wavefront sensor pixel scale, actuator pitch and natural guide star availability. We provide potential areas where costs savings can be made, and investigate trade-offs between performance and cost, and provide solutions that would enable such an instrument to be built with currently available technology. Our key recommendations include a trade-off for laser guide star wavefront sensor pixel scale of about 0.7 arcseconds per pixel, and a field of view of at least 7 arcseconds, that EMCCD technology should be used for natural guide star wavefront sensors even if reduced frame rate is nece...

  2. Large-strain time-temperature equivalence in high density polyethylene for prediction of extreme deformation and damage

    Directory of Open Access Journals (Sweden)

    Gray G.T.

    2012-08-01

    Full Text Available Time-temperature equivalence is a widely recognized property of many time-dependent material systems, where there is a clear predictive link relating the deformation response at a nominal temperature and a high strain-rate to an equivalent response at a depressed temperature and nominal strain-rate. It has been found that high-density polyethylene (HDPE obeys a linear empirical formulation relating test temperature and strain-rate. This observation was extended to continuous stress-strain curves, such that material response measured in a load frame at large strains and low strain-rates (at depressed temperatures could be translated into a temperature-dependent response at high strain-rates and validated against Taylor impact results. Time-temperature equivalence was used in conjuction with jump-rate compression tests to investigate isothermal response at high strain-rate while exluding adiabatic heating. The validated constitutive response was then applied to the analysis of Dynamic-Tensile-Extrusion of HDPE, a tensile analog to Taylor impact developed at LANL. The Dyn-Ten-Ext test results and FEA found that HDPE deformed smoothly after exiting the die, and after substantial drawing appeared to undergo a pressure-dependent shear damage mechanism at intermediate velocities, while it fragmented at high velocities. Dynamic-Tensile-Extrusion, properly coupled with a validated constitutive model, can successfully probe extreme tensile deformation and damage of polymers.

  3. Technology for Obtaining Large Size Complex Oxide Crystals for Experiments on Muon-Electron Conversion Registration in High Energy Physics

    Directory of Open Access Journals (Sweden)

    Gerasymov, Ya.

    2014-11-01

    Full Text Available Technological approaches for qualitative large size scintillation crystals growing based on rare-earth silicates are proposed. A method of iridium crucibles charging using eutectic phase instead of a oxyorthosilicate was developed.

  4. Reconstruction of large-size abdominal wall defect using biodegradable poly-p-dioxanone mesh: an experimental canine study

    National Research Council Canada - National Science Library

    Huang, Kenan; Ding, Xinyu; Lv, Benbo; Wei, Linyun; Sun, Juxian; Xu, Zhifei; Qin, Xiong; Tang, Hua

    2014-01-01

    ...) mesh for reconstructing large-size AWDs in an experimental canine model. Eighteen experimental canines were randomly and equally divided into three groups, namely, a PDO group, a Marlex group and a control group (n = 6 each...

  5. A new modification of combining vacuum therapy and brachytherapy in large subfascial soft-tissue sarcomas of the extremities

    Energy Technology Data Exchange (ETDEWEB)

    Rudert, Maximilian; Holzapfel, Boris Michael [Dept. of Orthopedics, Univ. of Wuerzburg (Germany); Dept. of Orthopedics and Traumatology, Klinikum Muenchen rechts der Isar, Technical Univ. of Munich (Germany); Winkler, Cornelia; Kneschaurek, Peter; Molls, Michael; Roeper, Barbara [Dept. of Radiation Oncology, Technical Univ. of Munich (Germany); Rechl, Hans; Gradinger, Reiner [Dept. of Orthopedics and Traumatology, Klinikum Muenchen rechts der Isar, Technical Univ. of Munich (Germany)

    2010-04-15

    Purpose: To present a modification of a technique combining the advantages of brachytherapy for local radiation treatment and vacuum therapy for wound conditioning after resection of subfascial soft-tissue sarcomas (STS) of the extremities. Patients and methods: Between January and May 2008, four patients with large (> 10 cm) subfascial STS of the thigh underwent marginal tumor excision followed by early postoperative HDR (high-dose-rate) brachytherapy (iridium-192) and vacuum therapy as part of their interdisciplinary treatment. The sponge of the vacuum system was used to stabilize brachytherapy applicators in parallel positions and to allow for a maximal wound contraction in the early postoperative phase, thus preventing seroma and deterioration of local dose distribution as optimized in computed tomography-(CT-)based three-dimensional conformal treatment planning. In three patients this was followed by external-beam radiotherapy. Acute wound complications and late effects according to LENT-SOMA after 4-8 months of follow-up were recorded. Results: the combination of vacuum and brachytherapy was applicable in all patients. CT scans from the 1st postoperative day showed the shrinkage of the sponge located in the tumor bed with the brachytherapy applicators in the intended position and easily visible. 15-18 Gy in fractions of 3 Gy bid prescribed to 5 mm tissue depth were applied over the next days with removal of the sponge and applicators on days 5-8. No early or late toxicity exceeding grade 2 was observed. The mean Enneking Score for functional outcome was 63% (perfect function = 100%). Conclusion: The combination of vacuum and brachytherapy is applicable and safe in the treatment of large subfascial STS. (orig.)

  6. APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope

    Science.gov (United States)

    Gonte, F.; Yaitskova, N.; Derie, F.; Constanza, A.; Brast, R.; Buzzoni, B.; Delabre, B.; Dierickx, P.; Dupuy, C.; Esteves, R.; Frank, C.; Guisard, S.; Karban, R.; Koenig, E.; Kolb, J.; Nylund, M.; Noethe, L.; Surdej, I.; Courteville, A.; Wilhelm, R.; Montoya, L.; Reyes, M.; Esposito, S.; Pinna, E.; Dohlen, K.; Ferrari, M.; Langlois, M.

    2005-08-01

    The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.

  7. Spatial variation in particle number size distributions in a large metropolitan area

    Directory of Open Access Journals (Sweden)

    J. F. Mejía

    2007-11-01

    Full Text Available Air quality studies have indicated that particle number size distribution (NSD is unevenly spread in urban air. To date, these studies have focussed on differences in concentration levels between sampling locations rather than differences in the underlying geometries of the distributions. As a result, the existing information on the spatial variation of the NSD in urban areas remains incomplete. To investigate this variation in a large metropolitan area in the southern hemisphere, NSD data collected at nine different locations during different campaigns of varying duration were compared using statistical methods. The spectra were analysed in terms of their modal structures (the graphical representation of the number size distribution function, cumulative distribution and number median diameter (NMD. The study found that with the exception of one site all distributions were bimodal or suggestive of bimodality. In general, peak concentrations were below 30 nm and NMDs below 50 nm, except at a site dominated by diesel trucks, where it shifted to around 50 and 60 nm respectively. Ultrafine particles (UFPs contributed to 82–90% of the particle number, nanoparticles (<50 nm to around 60–70%, except at the diesel traffic site, where their contribution dropped to 50%. Statistical analyses found that the modal structures heterogeneously distributed throughout Brisbane whereas it was not always the case for the NMD. The discussion led to the following site classification: (1 urban sites dominated by petrol traffic, (2 urban sites affected by the proximity to the road and (3 an isolated site dominated by diesel traffic. Comparisons of weekday and weekend data indicated that, the distributions were not statistically different. The only exception occurred at one site, where there is a significant drop in the number of diesel buses on the weekend. The differences in sampling period between sites did not affect the results. The statistics instead suggested

  8. Large size superelastic SMA bars: heat treatment strategy, mechanical property and seismic application

    Science.gov (United States)

    Wang, Wei; Fang, Cheng; Liu, Jia

    2016-07-01

    This paper reports a comprehensive study on the mechanical performance of large size superelastic shape memory alloy (SMA) bars, with the main focus given to their potential applications for seismic-resistant connections. A series of practical issues, including heat treatment, mechanical property assessment, and connection design/evaluation, were discussed aiming to benefit both material and civil engineering communities. The study commenced with a detailed discussion on the heat treatment strategy for SMA bars and the resulting mechanical properties including strength/stiffness, self-centring ability, energy dissipation, and fractural resistance. It was observed that the mechanical performance of the bars were quite sensitive to both annealing temperature and duration, and size effect was also evident, resulting in different appropriate heat treatment procedures for the bars with varying diameters. The optimally heat-treated SMA bars were machined to the bolt form and were then used for two types of practical self-centring connections, namely, connection with all SMA bars and that with combined angles and SMA bars. Through conducting full-scale tests, both connections were shown to have stable and controllable hysteretic responses till 5% loading drift. Up to 3% drift, the self-centring performance was satisfactory for both connection types, but beyond that the presence of the angles could lead to accumulated residual rotation. Importantly, for both connections, the deformation was accommodated by the SMA bolts or angles, whereas no plastic deformation was observed at any other structural members. This confirmed the feasibility of using such connections for highly resilient structures where minimal repair work is required after earthquakes.

  9. Two Test Items to Explore High School Students' Beliefs of Sample Size When Sampling from Large Populations

    Science.gov (United States)

    Bill, Anthony; Henderson, Sally; Penman, John

    2010-01-01

    Two test items that examined high school students' beliefs of sample size for large populations using the context of opinion polls conducted prior to national and state elections were developed. A trial of the two items with 21 male and 33 female Year 9 students examined their naive understanding of sample size: over half of students chose a…

  10. Effects of Strain Energy and Grain Size on Corrosion Resistance of Ultrafine Grained Fe-20%Cr Steels with Extremely low C and N Fabricated by ECAP

    Directory of Open Access Journals (Sweden)

    Muhammad Rifai

    2015-01-01

    Full Text Available Effect of strain energy and grain size on corrosion resistance of ultrafine grained (UFG Fe-20%Cr steels with extremely low C and N fabricated by equal channel angular pressing (ECAP was investigated. UFG structures of initial grain size of 144 nm exhibited the typical three-stage softening comprising recovery, recrystallization, and grain growth. Potentiodynamic polarization measurements were carried out with a conventional three-electrode cell to evaluate pitting potential. Pitting potential in 1000 mol·m−3 NaCl solution was nobler in UFG state, but pitting potential started to decrease monotonously at lower temperature compared to hardness. The degradation of corrosion resistance in the early stage of annealing is attributed to stability change of passivation by recovery of dislocation structures inside grains and in nonequilibrium grain boundaries. We therefore conclude that nobler potentials of UFG states were realized by not only grain size reduction but also defective deformation-induced UFG.

  11. Bra band size measurements derived from three-dimensional scans are not accurate in women with large, ptotic breasts.

    Science.gov (United States)

    McGhee, Deirdre E; Ramsay, Lauren G; Coltman, Celeste E; Gho, Sheridan A; Steele, Julie R

    2017-07-12

    This study investigated differences in standard measurements used to determine bra size, under-bust chest circumference (UBCC) and over-bust chest circumference (OBCC), measured from a three-dimensional scan (hand-held scanner) compared to the direct measurement in 111 women (age 21-56 years; right breast volume 57-1672 mL; bra size 10A-18G). Bland-Altman plots of UBCC measurements showed a large positive bias and wide limits of agreement (12 cm; -4.6 to 28 cm), which increased as band size increased but decreased when the breasts were digitally removed from the scan prior to the UBCC measurement. The difference in UBCC measurements determined from scans compared to direct measurement had a strong positive correlation with breast volume and breast ptotis. The OBCC measurements showed a small positive bias (2.4 cm; -3.4 to 8.4), consistent across the range of bra sizes. Bra band size measurements determined from three-dimensional scans can be inaccurate in women with large, ptotic breasts. Practitioner Summary: We investigated potential errors in anthropometric data derived from three-dimensional scans used for bra design and fit. Bra band size measurements taken from three-dimensional scans were over-estimated in women with large breasts, whereas bra cup size measurements were accurate to within one-cup size across the entire range of bra sizes.

  12. Strength and fatigue testing of large size wind turbines rotors. Vol. II: Full size natural vibration and static strength test, a reference case

    Energy Technology Data Exchange (ETDEWEB)

    Arias, F.; Soria, E.

    1996-12-01

    This report shows the methods and procedures selected to define a strength test for large size wind turbine, anyway in particular it application on a 500 kW blade and it results obtained in the test carried out in july of 1995 in Asinel`s test plant (Madrid). Henceforth, this project is designed in an abbreviate form whit the acronym SFAT. (Author)

  13. Prototyping a large field size IORT applicator for a mobile linear accelerator

    Science.gov (United States)

    Janssen, Rogier W. J.; Faddegon, Bruce A.; Dries, Wim J. F.

    2008-04-01

    The treatment of large tumors such as sarcomas with intra-operative radiotherapy using a Mobetron® is often complicated because of the limited field size of the primary collimator and the available applicators (max Ø100 mm). To circumvent this limitation a prototype rectangular applicator of 80 × 150 mm2 was designed and built featuring an additional scattering foil located at the top of the applicator. Because of its proven accuracy in modeling linear accelerator components the design was based on the EGSnrc Monte Carlo simulation code BEAMnrc. First, the Mobetron® treatment head was simulated both without an applicator and with a standard 100 mm applicator. Next, this model was used to design an applicator foil consisting of a rectangular Al base plate covering the whole beam and a pyramid of four stacked cylindrical slabs of different diameters centered on top of it. This foil was mounted on top of a plain rectangular Al tube. A prototype was built and tested with diode dosimetry in a water tank. Here, the prototype showed clinically acceptable 80 × 150 mm2 dose distributions for 4 MeV, 6 MeV and 9 MeV, obviating the use of complicated multiple irradiations with abutting field techniques. In addition, the measurements agreed well with the MC simulations, typically within 2%/1 mm.

  14. Large-sized cylinder of Bi-2223/Ni meshes composite bulk for current lead

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, M. [Department of Electrical Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 192-0015 (Japan); Yoshizawa, S. [Department of Environmental Systems, Meisei University, 2-1-1, Hodokubo, Hino, Tokyo 191-8506 (Japan)]. E-mail: yoshizaw@es.meisei-u.ac.jp; Hishinuma, Y. [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6, Oroshi, Toki, Gifu 509-5202 (Japan); Nishimura, A. [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6, Oroshi, Toki, Gifu 509-5202 (Japan); Yamazaki, S. [Department of Electrical Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 192-0015 (Japan); Kojima, S. [Department of Electrical Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 192-0015 (Japan)

    2006-10-01

    In order to improve the critical current density (J {sub c}) and mechanical property of Bi-2223 sintered bulk, Ni wire meshes were added in the bulk. For fabricating large-sized cylindrical Bi-2223/Ni meshes composite, composing meshes are easy to produce compared with adding a lot of wires. The mesh concentration was 18 x 18 meshes/cm{sup 2} using Ni wires of 0.25 mm in diameter. The Ni meshes were plated with Ag by 0.03 mm in thickness. We prepared the cylindrical sintered bulk for a current lead, 32 mm in outer diameter, 2 mm in thickness and 110 mm in length using a cold isostatic pressing (CIP) method. The samples were sintered at 845 deg. C for 50 h. After treatment again with CIP as an intermediate pressing, the samples were re-sintered. Small species were cut from the cylinder for measurement of critical current density (J {sub c}) at 77 K under self-field. There existed higher J {sub c} portions and low J {sub c} portions in the composite cylinder. Scanning electron microscope (SEM) observation showed that highly c-axis oriented and densely structured Bi-2223 plate-like grains could be formed around the interfacial region between the superconducting oxide and the Ag-plated Ni wires. There observed structural dislocation, which lead to low J {sub c} portions in the cylinder.

  15. Hydrophobic polymers modification of mesoporous silica with large pore size for drug release

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Shenmin, E-mail: smzhu@sjtu.edu.c [Shanghai Jiao Tong University, State Key Lab of Metal Matrix Composites (China); Zhang Di; Yang Na [Fudan University, Ministry of Education, Key Lab of Molecular Engineering of Polymers (China)

    2009-04-15

    Mesostructure cellular foam (MCF) materials were modified with hydrophobic polyisoprene (PI) through free radical polymerization in the pores network, and the resulting materials (MCF-PI) were investigated as matrices for drug storage. The successful synthesis of PI inside MCF was characterized by Fourier transform infrared (FT-IR), hydrogen nuclear magnetic resonance ({sup 1}H NMR), X-ray diffraction patterns (XRD) and nitrogen adsorption/desorption measurements. It was interesting to find the resultant system held a relatively large pore size (19.5 nm) and pore volume (1.02 cm{sup 3} g{sup -1}), which would benefit for drug storage. Ibuprofen (IBU) and vancomycin were selected as model drugs and loaded onto unmodified MCF and modified MCF (MCF-PI). The adsorption capacities of these model drugs on MCF-PI were observed increase as compared to that of on pure MCF, due to the trap effects induced by polyisoprene chains inside the pores. The delivery system of MCF-PI was found to be more favorable for the adsorption of IBU (31 wt%, IBU/silica), possibly attributing to the hydrophobic interaction between IBU and PI formed on the internal surface of MCF matrix. The release of drug through the porous network was investigated by measuring uptake and release of IBU.

  16. Large-area, size-tunable Si nanopillar arrays with enhanced antireflective and plasmonic properties.

    Science.gov (United States)

    Niu, Lihong; Jiang, Xiaohong; Zhao, Yaolong; Ma, Haiguang; Yang, Jingjing; Cheng, Ke; Du, Zuliang

    2016-08-01

    In this paper, a novel method using the modified Langmuir-Blodgett and float-transfer techniques was introduced to construct the perfect PS monolayer nanosphere template with large area up to cm(2). Based on such templates, the diameter, length, packing density, and the shape of Si nanopillar arrays (Si NPAs) could be precisely controlled and tuned through the modified nanosphere lithography combined with a metal-assisted chemical etching (NSL-MACE) method. Manipulation of the etching time can effectively avoid permanent deformation/clumping to generate size-tunable Si NPAs. The optical properties of the Si NPAs can be controlled by the Si NPA morphologies resulting from the different reactive ion etching (RIE) time and chemical etching time. The enhanced antireflective property and electromagnetic field effect of Au/Si NPAs were proved by the results. The new modified NSL-MACE technique with the capability of scale-up fabrication of Si NPAs would be helpful for potential applications in optoelectronic devices.

  17. Impact of Large Family Size on the Reproductive Health of Women at Palosi Peshawar

    Directory of Open Access Journals (Sweden)

    Anwar Alam

    2012-04-01

    Full Text Available This study was under taken on, “Impact of large family size on the reproductive health of women at Palosi Peshawar”. For this study the researcher contacted 30 women respondents on purposive sampling basis out of 332 married women in Palosi Peshawar (DCR 1998 Peshawar. Interview schedule was used as a tool of data collection for illiterate respondents while questionnaire was used for educated respondents. The study indicates that due to illiteracy and ignorance, the women of rural areas are unaware about the complications, facilities, problems and precautions. They faced work pressure during pregnancy due to joint family system. Mostly the respondents were facing health problems during pregnancy due to the non-availability of female doctors, LHV/LHW were not visiting their home, no facilities of maternity clinics and lack of medicines. The desire for more children affected the mother child health and led to physical, psychological problems and also affect the reproductive health of woman and also caused excessive deliveries, which were harmful to mother child health. The reproductive problems of respondents can be resolved through proper nutrition, availability of maternity clinics, reproductive health centers, family health & welfare centers, quality contraceptives and proper medicines.

  18. Fabrication of large size alginate beads for three-dimensional cell-cluster culture

    Science.gov (United States)

    Zhang, Zhengtao; Ruan, Meilin; Liu, Hongni; Cao, Yiping; He, Rongxiang

    2017-08-01

    We fabricated large size alginate beads using a simple microfluidic device under a co-axial injection regime. This device was made by PDMS casting with a mold formed by small diameter metal and polytetrafluorothylene tubes. Droplets of 2% sodium alginate were generated in soybean oil through the device and then cross-linked in a 2% CaCl2 solution, which was mixed tween80 with at a concentration of 0.4 to 40% (w/v). Our results showed that the morphology of the produced alginate beads strongly depends on the tween80 concentration. With the increase of concentration of tween80, the shape of the alginate beads varied from semi-spherical to tailed-spherical, due to the decrease of interface tension between oil and cross-link solution. To access the biocompatibility of the approach, MCF-7 cells were cultured with the alginate beads, showing the formation of cancer cells clusters which might be useful for future studies.

  19. Measurement of fissile mass in large-size containers with a transportable linear accelerator

    Science.gov (United States)

    Romeyer Dherbey, Jacques; Lyoussi, A.; Buisson, A.

    1997-02-01

    The quantification of transuranic material (TRU) in waste packages is a common problem of countries working in the field of nuclear nondestructive inspection. The direct measurement of TRU mass inside large size closed containers is difficult due to several effects, mainly the matrix attenuation and uncertainty on the localization of the radioactive mass. The present document describes the method being developed to assay conditioned waste packages using a transportable linear accelerator which is called Mini- Linatron. The system uses a pulsed electron beam from the Mini-Linatron to produce high energy bremsstrahlung photon bursts from thin metallic converter. The transportable linear accelerator operates at 6, 9 and 11 MeV with a repetition rate between 10 to 300 Hz and a 4.5 microsecond(s) pulse duration. The maximum gamma dose rate is about 23 Gy/mn at 1 m. The photons induce fission in fissile and fertile nuclei. We counted delayed neutrons emitted after each pulse by using Sequential Photon Interrogation and Neutron Counting Signatures technique which has ben developed in this framework. Results of measurements on an experimental active gamma interrogation facility for embedded intermediate and low level wastes are presented. Finally, the advantages and performances of the photofission interrogation technique, the use of a transportable electron linear accelerator as a particle source, and the experimental and electronic details will be discussed.

  20. The Optical System for the Large Size Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Hayashida, M; Teshima, M; de Almeida, U Barres; Chikawa, M; Cho, N; Fukami, S; Gadola, A; Hanabata, Y; Horns, D; Jablonski, C; Katagiri, H; Kagaya, M; Ogino, M; Okumura, A; Saito, T; Stadler, R; Steiner, S; Straumann, U; Vollhardt, A; Wetteskind, H; Yamamoto, T; Yoshida, T

    2015-01-01

    The Large Size Telescope (LST) of the Cherenkov Telescope Array (CTA) is designed to achieve a threshold energy of 20 GeV. The LST optics is composed of one parabolic primary mirror 23 m in diameter and 28 m focal length. The reflector dish is segmented in 198 hexagonal, 1.51 m flat to flat mirrors. The total effective reflective area, taking into account the shadow of the mechanical structure, is about 368 m$^2$. The mirrors have a sandwich structure consisting of a glass sheet of 2.7 mm thickness, aluminum honeycomb of 60 mm thickness, and another glass sheet on the rear, and have a total weight about 47 kg. The mirror surface is produced using a sputtering deposition technique to apply a 5-layer coating, and the mirrors reach a reflectivity of $\\sim$94% at peak. The mirror facets are actively aligned during operations by an active mirror control system, using actuators, CMOS cameras and a reference laser. Each mirror facet carries a CMOS camera, which measures the position of the light spot of the optical ...

  1. Innovative heating of large-size automotive Li-ion cells

    Science.gov (United States)

    Yang, Xiao-Guang; Liu, Teng; Wang, Chao-Yang

    2017-02-01

    Automotive Li-ion cells are becoming much larger and thicker in order to reduce the cell count and increase battery reliability, posing a new challenge to battery heating from the cold ambient due to poor through-plane heat transfer across a cell's multiple layers of electrodes and separators. In this work, widely used heating methods, including internal heating using the cell's resistance and external heating by resistive heaters, are compared with the recently developed self-heating Li-ion battery (SHLB) with special attention to the heating speed and maximum local temperature critical to battery safety. Both conventional methods are found to be slow due to low heating power required to maintain battery safety. The heating power in the external heating method is limited by the risk of local over-heating, in particular for thick cells. As a result, the external heating method is restricted to ∼20 min slow heating for a 30 °C temperature rise. In contrast, the SHLB is demonstrated to reach a heating speed of 1-2 °C/sec, ∼40 times faster for large-size thick cells, with nearly 100% heating efficiency and spatially uniform heating free from safety concerns.

  2. Development of the Photomultiplier-Tube Readout System for the CTA Large Size Telescope

    CERN Document Server

    Kubo, H; Awane, Y; Bamba, A; Barcelo, M; Barrio, J A; Blanch, O; Boix, J; Delgado, C; Fink, D; Gascon, D; Gunji, S; Hagiwara, R; Hanabata, Y; Hatanaka, K; Hayashida, M; Ikeno, M; Kabuki, S; Katagiri, H; Kataoka, J; Konno, Y; Koyama, S; Kishimoto, T; Kushida, J; Martinez, G; Masuda, S; Miranda, J M; Mirzoyan, R; Mizuno, T; Nagayoshi, T; Nakajima, D; Nakamori, T; Ohoka, H; Okumura, A; Orito, R; Saito, T; Sanuy, A; Sasaki, H; Sawada, M; Schweizer, T; Sugawara, R; Sulanke, K -H; Tajima, H; Tanaka, M; Tanaka, S; Tejedor, L A; Terada, Y; Teshima, M; Tokanai, F; Tsuchiya, Y; Uchida, T; Ueno, H; Umehara, K; Yamamoto, T

    2013-01-01

    We have developed a prototype of the photomultiplier tube (PMT) readout system for the Cherenkov Telescope Array (CTA) Large Size Telescope (LST). Two thousand PMTs along with their readout systems are arranged on the focal plane of each telescope, with one readout system per 7-PMT cluster. The Cherenkov light pulses generated by the air showers are detected by the PMTs and amplified in a compact, low noise and wide dynamic range gain block. The output of this block is then digitized at a sampling rate of the order of GHz using the Domino Ring Sampler DRS4, an analog memory ASIC developed at Paul Scherrer Institute. The sampler has 1,024 capacitors per channel and four channels are cascaded for increased depth. After a trigger is generated in the system, the charges stored in the capacitors are digitized by an external slow sampling ADC and then transmitted via Gigabit Ethernet. An onboard FPGA controls the DRS4, trigger threshold, and Ethernet transfer. In addition, the control and monitoring of the Cockcrof...

  3. Silicon Photomultiplier Research and Development Studies for the Large Size Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Rando, Riccardo; Dazzi, Francesco; De Angelis, Alessandro; Dettlaff, Antonios; Dorner, Daniela; Fink, David; Fouque, Nadia; Grundner, Felix; Haberer, Werner; Hahn, Alexander; Hermel, Richard; Korpar, Samo; Mezek, Gašper Kukec; Maier, Ronald; Manea, Christian; Mariotti, Mosè; Mazin, Daniel; Mehrez, Fatima; Mirzoyan, Razmik; Podkladkin, Sergey; Reichardt, Ignasi; Rhode, Wolfgang; Rosier, Sylvie; Schultz, Cornelia; Stella, Carlo; Teshima, Masahiro; Wetteskind, Holger; Zavrtanik, Marko

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the the next generation facility of imaging atmospheric Cherenkov telescopes; two sites will cover both hemispheres. CTA will reach unprecedented sensitivity, energy and angular resolution in very-high-energy gamma-ray astronomy. Each CTA array will include four Large Size Telescopes (LSTs), designed to cover the low-energy range of the CTA sensitivity ($\\sim$20 GeV to 200 GeV). In the baseline LST design, the focal-plane camera will be instrumented with 265 photodetector clusters; each will include seven photomultiplier tubes (PMTs), with an entrance window of 1.5 inches in diameter. The PMT design is based on mature and reliable technology. Recently, silicon photomultipliers (SiPMs) are emerging as a competitor. Currently, SiPMs have advantages (e.g. lower operating voltage and tolerance to high illumination levels) and disadvantages (e.g. higher capacitance and cross talk rates), but this technology is still young and rapidly evolving. SiPM technology has a strong pot...

  4. Investigation of Low-Cost Surface Processing Techniques for Large-Size Multicrystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Yuang-Tung Cheng

    2010-01-01

    Full Text Available The subject of the present work is to develop a simple and effective method of enhancing conversion efficiency in large-size solar cells using multicrystalline silicon (mc-Si wafer. In this work, industrial-type mc-Si solar cells with area of 125×125 mm2 were acid etched to produce simultaneously POCl3 emitters and silicon nitride deposition by plasma-enhanced chemical vapor deposited (PECVD. The study of surface morphology and reflectivity of different mc-Si etched surfaces has also been discussed in this research. Using our optimal acid etching solution ratio, we are able to fabricate mc-Si solar cells of 16.34% conversion efficiency with double layers silicon nitride (Si3N4 coating. From our experiment, we find that depositing double layers silicon nitride coating on mc-Si solar cells can get the optimal performance parameters. Open circuit (Voc is 616 mV, short circuit current (Jsc is 34.1 mA/cm2, and minority carrier diffusion length is 474.16 μm. The isotropic texturing and silicon nitride layers coating approach contribute to lowering cost and achieving high efficiency in mass production.

  5. K2-66b and K2-106b: Two Extremely Hot Sub-Neptune-size Planets with High Densities

    Science.gov (United States)

    Sinukoff, Evan; Howard, Andrew W.; Petigura, Erik A.; Fulton, Benjamin J.; Crossfield, Ian J. M.; Isaacson, Howard; Gonzales, Erica; Crepp, Justin R.; Brewer, John M.; Hirsch, Lea; Weiss, Lauren M.; Ciardi, David R.; Schlieder, Joshua E.; Benneke, Bjoern; Christiansen, Jessie L.; Dressing, Courtney D.; Hansen, Brad M. S.; Knutson, Heather A.; Kosiarek, Molly; Livingston, John H.; Greene, Thomas P.; Rogers, Leslie A.; Lépine, Sébastien

    2017-06-01

    We report precise mass and density measurements of two extremely hot sub-Neptune-size planets from the K2 mission using radial velocities, K2 photometry, and adaptive optics imaging. K2-66 harbors a close-in sub-Neptune-sized ({2.49}-0.24+0.34 {R}\\oplus ) planet (K2-66b) with a mass of 21.3+/- 3.6 {M}\\oplus . Because the star is evolving up the subgiant branch, K2-66b receives a high level of irradiation, roughly twice the main-sequence value. K2-66b may reside within the so-called “photoevaporation desert,” a domain of planet size and incident flux that is almost completely devoid of planets. Its mass and radius imply that K2-66b has, at most, a meager envelope fraction (radiation environments. Their high densities reflect the challenge of retaining a substantial gas envelope in such extreme environments.

  6. Effects of a novel forced intensive strengthening technique on muscle size and upper extremity function in a patient with chronic stroke.

    Science.gov (United States)

    Jeong, Hee-Won; Chon, Seung-Chul

    2015-11-01

    [Purpose] This research demonstrated a forced intensive strength technique as a novel treatment for muscle power and function in the affected upper extremity muscle to determine the clinical feasibility with respect to upper extremity performance in a stroke hemiparesis. [Subject and Methods] The subject was a patient with chronic stroke who was dependent on others for performing the functional activities of his affected upper extremity. The technique incorporates a comprehensive approach of forced, intensive, and strength-inducing activities to enhance morphological changes associated with motor learning of the upper extremity. The forced intensive strength technique consisted of a 6-week course of sessions lasting 60 minutes per day, five times a week. [Results] After the 6-week intervention, the difference between relaxation and contraction of the affected extensor carpi radialis muscle increased from 0.28 to 0.63 cm(2), and that of the affected triceps brachii muscle increased from 0.30 to 0.90 cm(2). The results of clinical tests including the modified Ashworth scale (MAS; from 1+ to 1), muscle strength (from 15 to 32 kg), the manual function test (MFT; scores of 16/32 to 27/32 score), the Fugl-Meyer assessment (FMA; scores of 29/66 to 49/66 score), and the Jebsen-Taylor hand function test (JTHFT; from 38/60 to 19/60 sec) were improved. [Conclusion] Our results suggest that the forced intensive strength technique may have a beneficial effect on the muscle size of the upper extremity and motor function in patients with chronic stroke.

  7. A comparison of workplace safety perceptions among financial decision-makers of medium- vs. large-size companies.

    Science.gov (United States)

    Huang, Yueng-Hsiang; Leamon, Tom B; Courtney, Theodore K; Chen, Peter Y; DeArmond, Sarah

    2011-01-01

    This study, through a random national survey in the U.S., explored how corporate financial decision-makers perceive important workplace safety issues as a function of the size of the company for which they worked (medium- vs. large-size companies). Telephone surveys were conducted with 404 U.S. corporate financial decision-makers: 203 from medium-size companies and 201 from large companies. Results showed that the patterns of responding for participants from medium- and large-size companies were somewhat similar. The top-rated safety priorities in resource allocation reported by participants from both groups were overexertion, repetitive motion, and bodily reaction. They believed that there were direct and indirect costs associated with workplace injuries and for every dollar spent improving workplace safety, more than four dollars would be returned. They perceived the top benefits of an effective safety program to be predominately financial in nature - increased productivity and reduced costs - and the safety modification participants mentioned most often was to have more/better safety-focused training. However, more participants from large- than medium-size companies reported that "falling on the same level" was the major cause of workers' compensation loss, which is in line with industry loss data. Participants from large companies were more likely to see their safety programs as better than those of other companies in their industries, and those of medium-size companies were more likely to mention that there were no improvements needed for their companies.

  8. Fabrication of large-sized two-dimensional ordered surface array with well-controlled structure via colloidal particle lithography.

    Science.gov (United States)

    Meng, Xiaohui; Zhang, Xinping; Ye, Lei; Qiu, Dong

    2014-06-17

    Epoxy resin coated glass slides were used for colloidal particle lithography, in order to prepare well-defined 2D surface arrays. Upon the assistance of a large-sized 2D colloidal single crystal as template, centimeter-sized ordered surface arrays of bowl-like units were obtained. Systematic studies revealed that the parameters of obtained surface arrays could be readily controlled by some operational factors, such as temperature, epoxy resin layer thickness, and template particle size. With epoxy resin substituting for normal linear polymer, the height/diameter ratio of bowls in the formed surface arrays can be largely increased. With further reactive plasma etching, the parameters of ordered surface arrays could be finely tuned through controlling etching time. This study provides a facile way to prepare large-sized 2D surface arrays with tunable parameters.

  9. Small population size and extremely low levels of genetic diversity in island populations of the platypus, Ornithorhynchus anatinus.

    Science.gov (United States)

    Furlan, Elise; Stoklosa, J; Griffiths, J; Gust, N; Ellis, R; Huggins, R M; Weeks, A R

    2012-04-01

    Genetic diversity generally underpins population resilience and persistence. Reductions in population size and absence of gene flow can lead to reductions in genetic diversity, reproductive fitness, and a limited ability to adapt to environmental change increasing the risk of extinction. Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk. Two island populations of the platypus, Ornithorhynchus anatinus, exist; a naturally occurring population on King Island in Bass Strait and a recently introduced population on Kangaroo Island off the coast of South Australia. Here we assessed the genetic diversity within these two island populations and contrasted these patterns with genetic diversity estimates in areas from which the populations are likely to have been founded. On Kangaroo Island, we also modeled live capture data to determine estimates of population size. Levels of genetic diversity in King Island platypuses are perilously low, with eight of 13 microsatellite loci fixed, likely reflecting their small population size and prolonged isolation. Estimates of heterozygosity detected by microsatellites (H(E)= 0.032) are among the lowest level of genetic diversity recorded by this method in a naturally outbreeding vertebrate population. In contrast, estimates of genetic diversity on Kangaroo Island are somewhat higher. However, estimates of small population size and the limited founders combined with genetic isolation are likely to lead to further losses of genetic diversity through time for the Kangaroo Island platypus population. Implications for the future of these and similarly isolated or genetically depauperate populations are discussed.

  10. Extreme sexual brain size dimorphism in sticklebacks: a consequence of the cognitive challenges of sex and parenting?

    Directory of Open Access Journals (Sweden)

    Alexander Kotrschal

    Full Text Available Selection pressures that act differently on males and females produce numerous differences between the sexes in morphology and behaviour. However, apart from the controversial report that males have slightly heavier brains than females in humans, evidence for substantial sexual dimorphism in brain size is scarce. This apparent sexual uniformity is surprising given that sexually distinct selection pressures are ubiquitous and that brains are one of the most plastic vertebrate organs. Here we demonstrate the highest level of sexual brain size dimorphism ever reported in any vertebrate: male three-spined stickleback of two morphs in an Icelandic lake have 23% heavier brains than females. We suggest that this dramatic sexual size dimorphism is generated by the many cognitively demanding challenges that males are faced in this species, such as an elaborate courtship display, the construction of an ornate nest and a male-only parental care system. However, we consider also alternative explanations for smaller brains in females, such as life-history trade-offs. Our demonstration of unprecedented levels of sexual dimorphism in brain size in the three-spined stickleback implies that behavioural and life-history differences among the sexes can have strong effects also on neural development and proposes new fields of research for understanding brain evolution.

  11. X-Ray and Extreme Ultraviolet Emission from Small-Sized Kr Clusters Irradiated by 150-fs Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    王骐; 程元丽; 赵永蓬; 夏元钦; 陈建新; 肖亦凡

    2003-01-01

    x-ray and extreme ultraviolet (EUV) emission from Kr clusters irradiated by 150-fs laser pulses at the peak laser intensity of 5×1015W/cm2 was experimentally investigated. Strong transitions (10nm-13nm) from Kr X and Kr 1X were observed and some spectral lines from Kr ⅩⅢ and Kr ⅩⅣ, which have been predicted to be not produced by optical-field-ionization at the laser intensity used, also appeared. The laser energy absorption and the intensity of x-ray emission started to grow remarkably above the backing pressure of 0.5 MPa and to decrease at the backing pressure of 3 MPa. It is suggested that an optimum backing pressure may exist for Kr clusters heated by 150 fs laser pulses at a certain laser intensity to produce x-ray emission.

  12. Analytical robustness of nine common assays: frequency of outliers and extreme differences identified by a large number of duplicate measurements.

    Science.gov (United States)

    Neubig, Stefanie; Grotevendt, Anne; Kallner, Anders; Nauck, Matthias; Petersmann, Astrid

    2017-02-15

    Duplicate measurements can be used to describe the performance and analytical robustness of assays and to identify outliers. We performed about 235,000 duplicate measurements of nine routinely measured quantities and evaluated the observed differences between the replicates to develop new markers for analytical performance and robustness. Catalytic activity concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and concentrations of calcium, cholesterol, creatinine, C-reactive protein (CRP), lactate, triglycerides and thyroid-stimulating hormone (TSH) in 237,261 patient plasma samples were measured in replicates using routine methods. The performance of duplicate measurements was evaluated in scatterplots with a variable and symmetrical zone of acceptance (A-zone) around the equal line. Two quality markers were established: 1) AZ95: the width of an A-zone at which 95% of all duplicate measurements were within this zone; and 2) OPM (outliers per mille): the relative number of outliers if an A-zone width of 5% was applied. The AZ95 ranges from 3.2% for calcium to 11.5% for CRP and the OPM from 5 (calcium) to 250 (creatinine). Calcium, TSH and cholesterol have an AZ95 of less than 5% and an OPM of less than 50. Duplicate measurements of a large number of patient samples identify even low frequencies of extreme differences and thereof defined outliers. We suggest two additional quality markers, AZ95 and OPM, to complement description of assay performance and robustness. This approach can aid the selection process of measurement procedures in view of clinical needs.

  13. Statistical modelling of wildfire size and intensity: a step toward meteorological forecasting of summer extreme fire risk

    OpenAIRE

    Hernandez, C; Keribin, C.; Drobinski, P.; Turquety, S.

    2015-01-01

    International audience; In this article we investigate the use of statistical methods for wildfire risk assessment in the Mediterranean Basin using three meteorological covariates, the 2 m temperature anomaly, the 10 m wind speed and the January– June rainfall occurrence anomaly. We focus on two remotely sensed characteristic fire variables, the burnt area (BA) and the fire radiative power (FRP), which are good proxies for fire size and intensity respectively. Using the fire data we determine...

  14. Precursors of extreme increments

    CERN Document Server

    Hallerberg, S; Holstein, D; Kantz, H; Hallerberg, Sarah; Altmann, Eduardo G.; Holstein, Detlef; Kantz, Holger

    2006-01-01

    We investigate precursors and predictability of extreme events in time series, which consist in large increments within successive time steps. In order to understand the predictability of this class of extreme events, we study analytically the prediction of extreme increments in AR(1)-processes. The resulting strategies are then applied to predict sudden increases in wind speed recordings. In both cases we evaluate the success of predictions via creating receiver operator characteristics (ROC-plots). Surprisingly, we obtain better ROC-plots for completely uncorrelated Gaussian random numbers than for AR(1)-correlated data. Furthermore, we observe an increase of predictability with increasing event size. Both effects can be understood by using the likelihood ratio as a summary index for smooth ROC-curves.

  15. Coronary calcium scores are systematically underestimated at a large chest size : A multivendor phantom study

    NARCIS (Netherlands)

    Willemink, Martin J.; Abramiuc, Bronislaw; den Harder, Annemarie M.; van der Werf, Niels R.; de Jong, Pim A.; Budde, Ricardo P. J.; Wildberger, Joachim E.; Vliegenthart, Rozemarijn; Willems, Tineke P.; Greuter, Marcel J. W.; Leiner, Tim

    2015-01-01

    Objective: To evaluate the effect of chest size on coronary calcium score (CCS) as assessed with new-generation CT systems from 4 major vendors. Methods: An anthropomorphic, small-sized (300 x 200 mm) chest phantom containing 100 small calcifications (diameters, 0.5-2.0 mm) was evaluated with and wi

  16. The welfare implications of large litter size in the domestic pig II: management factors

    DEFF Research Database (Denmark)

    Baxter, E.M.; Rutherford, K.M.D.; D'Eath, R.B.

    2013-01-01

    Increasing litter size has long been a goal of pig (Sus scrofa domesticus) breeders and producers in many countries. Whilst this has economic and environmental benefits for the pig industry, there are also implications for pig welfare. Certain management interventions are used when litter size ro...

  17. Extremely Small Sizes for Faint z ˜ 2-8 Galaxies in the Hubble Frontier Fields: A Key Input for Establishing Their Volume Density and UV Emissivity

    Science.gov (United States)

    Bouwens, R. J.; Illingworth, G. D.; Oesch, P. A.; Atek, H.; Lam, D.; Stefanon, M.

    2017-07-01

    We provide the first observational constraints on the sizes of the faintest galaxies lensed by the Hubble Frontier Fields (HFF) clusters. Ionizing radiation from faint galaxies likely drives cosmic reionization, and the HFF initiative provides a key opportunity to find such galaxies. However, we cannot assess their ionizing emissivity without a robust measurement of their sizes, since this is key to quantifying both their prevalence and the faint-end slope to the UV luminosity function. Here we provide the first size constraints with two new techniques. The first utilizes the fact that the detectability of highly magnified galaxies as a function of shear is very dependent on a galaxy’s size. Only the most compact galaxies remain detectable in high-shear regions (versus a larger detectable size range for low shear), a phenomenon we quantify using simulations. Remarkably, however, no correlation is found between the surface density of faint galaxies and the predicted shear, using 87 high-magnification (μ =10-100) z˜ 2-8 galaxies seen behind the first four HFF clusters. This can only be the case if faint (˜ -15 mag) galaxies have significantly smaller sizes than more luminous galaxies, i.e., ≲ 30 mas or 160-240 pc. As a second size probe, we rotate and stack 26 faint high-magnification sources along the major shear axis. Less elongation is found even for objects with an intrinsic half-light radius of 10 mas. Together, these results indicate that extremely faint z˜ 2-8 galaxies have near point-source profiles (half-light radii <30 mas and perhaps 5-10 mas). These results suggest smaller completeness corrections and hence shallower faint-end slopes for the z˜ 2-8 LFs than derived in some recent studies (by {{Δ }}α ≳ 0.1-0.3).

  18. Ventilation in medium-sized and large boiler houses; Ventilation i medelstora och stoerre pannhus

    Energy Technology Data Exchange (ETDEWEB)

    Grotherus, Dan [AaF Installation AB, Oerebro (Sweden); Larsson, Tord [Oerebro Univ. (Sweden). Dept. of Technology

    2005-04-01

    The purpose of this report is to exemplify and clarify the need for ventilation in medium-sized and large boiler houses. We will furthermore present some recommendations, guidelines and advice for the design and construction of a boiler house ventilation system to the plant owners and suppliers of equipment. Boiler house ventilation can be performed in different ways using mechanical or natural ventilation. The solution to be chosen depends on the following factors: Working environment requirements and a necessity to control temperature and pressure in the boiler house; The design of the boiler plant and house; The need for combustion air; The investment expenditure as well as operation and maintenance costs. Mechanical ventilation should be chosen if the aim is a controllable 'climate'. The mechanical ventilation can be either centrally situated or distributed with many aggregates in the boiler house. Centrally situated ventilation equipment will give a higher accessibility and lower maintenance costs than a distributed ventilation system. If the boiler house is designed with natural ventilation the air and flue gas fans will be the only ones installed. In this case temperature and pressure inside the boiler house will be difficult to control. The design factor for the ventilation plant in a boiler house is in most cases the demand to cool the air inside the boiler house to approximately 45 deg C. This is the highest temperature allowed by the Occupational Safety and Health Act in a work environment where the boiler operator is working alone. The air flow which is required for the combustion is normally less than the air flow needed to cool the air in the boiler house. The supply air which is cooling the air inside the boiler house should be supplied on several different levels to attain an efficient cooling. If the combustion air is taken from the heated indoor air the boiler house will work as a heat reclaimer. The difference between outdoor and indoor

  19. Variations in the pallial organ sizes of the invasive oyster, Crassostrea gigas, along an extreme turbidity gradient

    Science.gov (United States)

    Dutertre, Mickaël; Barillé, Laurent; Beninger, Peter G.; Rosa, Philippe; Gruet, Yves

    2009-11-01

    Spatial size variations of labial palps, gills and the adductor muscle of the invasive feral oyster, Crassostrea gigas, were studied along two gradients of suspended particulate matter (SPM) concentrations in the temperate macrotidal Bourgneuf Bay, (annual mean SPM concentration gradient of 21.0-154.0 mg l -1) and the adjacent Loire Estuary (annual mean SPM concentration gradient of 24.1-630.4 mg l -1) on the French Atlantic Coast. The gill-to-palp (G:P) ratios decreased with increasing turbidity, both in the bay and the estuary. Changes in G:P ratios were chiefly related to palp area variations, increasing gradually from low turbidity to very high-turbidity sites, while gill area showed no clear relationship with turbidity conditions. The G:P ratio, showing a significant relationship ( r2 = 0.97) with SPM concentrations, is proposed as a pallial organ index of oyster acclimation to turbidity conditions. The area of the striated part of the adductor muscle was always greater than that of the smooth one, and adductor muscle area tended to decrease when SPM concentration increased. These observations show the morphological capacity of the oyster C. gigas to tolerate SPM concentrations above the feeding cessation thresholds previously determined experimentally. They also suggest that pallial organ size variations could help explain the success of recent feral oyster invasions in temperate turbid ecosystems.

  20. Mathematical Modelling of Nonstationary Physico Chemical Processes in Large Sized SPRM Pyrotechnical Ignition System

    Directory of Open Access Journals (Sweden)

    Alexey M. Lipanov

    1997-10-01

    Full Text Available In this paper, the laws of the unstable wave processes accompanying the combustion abnormal mode in the large-sized solid propellant rocket motor {SPRM pyrotechnical ignition system {IS are investigated by numerical method. The IS contains the main {cylindrical channel (MC having uniform perforation over the lateral surface, The left MC boundary is blocked and the right boundary is uniformly perforated. The whole perforation is hermetically sealed from outside. The additional {cylindrical channel {AC {an initial impulse amplifier with uniform perforation over the lateral surface is installed into the MC cavity, coaxially to MC. The right AC boundary is blocked, and the time-varying high-temperature gas flow, containing incandescent 'particles is supplied from initiator, equipped with a fast burning compound, through AC left perforated boundary. To imitate the exploitation conditions, the IS is placed in cylindrical imitation chamber {imitative SPRM. In a number of cases, before the beginning of the IS operation, a situation can be realised when the pelletised solid propellant {PSP mass is non-uniformly distributed along the IS AC length, and the greater part of the AC lateral perforation is blocked by the PSP inserted in the IS MC. Under these conditions, the effect of abnormal strengthening of the pressure waves at the AC boundaries is possible. For describing the abnormal nonstationary physico-chemical processes, a mathematical model is developed. For the check-up of this complex model, the numerical calculation results have been compared with the results of the fire stand tests for the regular IS and the engine. The numerical analysis of the unstable wave process development in the AC has shown that the rise of the pressure with an ever increasing amplitude is realised at the moment, when a shock wave reflects alternately, on the left and on the right AC boundaries. The effect of the pressure waves' abnormal strengthening can result in the

  1. The temperature and size distribution of large water clusters from a non-equilibrium model

    Energy Technology Data Exchange (ETDEWEB)

    Gimelshein, N. [Gimel, Inc., San Jose, California 95124 (United States); Gimelshein, S., E-mail: gimelshe@usc.edu [University of Southern California, Los Angeles, California 90089 (United States); Pradzynski, C. C.; Zeuch, T., E-mail: tzeuch1@gwdg.de [Institut für Physikalische Chemie, Universität Göttingen, Tammanstr. 6, D-37077 Göttingen (Germany); Buck, U., E-mail: ubuck@gwdg.de [Max-Planck-Institut für Dynamik und Selbstorganisation, Am Faßberg 17, D-37077 Göttingen (Germany)

    2015-06-28

    A hybrid Lagrangian-Eulerian approach is used to examine the properties of water clusters formed in neon-water vapor mixtures expanding through microscale conical nozzles. Experimental size distributions were reliably determined by the sodium doping technique in a molecular beam machine. The comparison of computed size distributions and experimental data shows satisfactory agreement, especially for (H{sub 2}O){sub n} clusters with n larger than 50. Thus validated simulations provide size selected cluster temperature profiles in and outside the nozzle. This information is used for an in-depth analysis of the crystallization and water cluster aggregation dynamics of recently reported supersonic jet expansion experiments.

  2. Generalized cubic equation of state and the radial distribution functions at contact for multi-component hard-sphere mixtures with large size ratio

    Science.gov (United States)

    Sun, Jiu-Xun; Wu, Qiang; Cai, Ling-Cang; Jin, Ke

    2014-06-01

    A generalized cubic (GC) equation of state (EOS) with two independent parameters is proposed. The GC EOS can include EOS from both virial and compressibility routes of Percus-Yevick theory in it as special cases. The two parameters are determined by fitting well-known virial coefficients of pure fluid. The generalized cubic EOS can be directly and consistently extended to multi-component mixtures merely demanding of the EOS of mixtures also is cubic, and combining two strict physical conditions for the radial distribution functions at contact (RDFC) of mixtures. The calculated virial coefficients of pure fluid and predicted compressibility factors and RDFC for both pure fluid and mixtures are excellent as compared with the simulation data. The values of RDFC for mixtures with extremely large size ratio are far better than the expressions in literature.

  3. Small plants, large plants: the importance of plant size for the physiological ecology of vascular epiphytes.

    Science.gov (United States)

    Zotz, G; Hietz, P; Schmidt, G

    2001-10-01

    Recently, a number of publications have reported that many physiological properties of vascular epiphytes are a function of plant size. This short review will summarize what is known to date about this phenomenon, describe the possible mechanism and will discuss the consequences for the present understanding of epiphyte biology. Size-related changes are also known from other plant groups and it is argued that close attention should be paid to the size of the organisms under study in order to understand the performance and survival of a species in the field. In the light of these findings, the results of many earlier studies on epiphyte ecophysiology are now difficult to interpret because essential information on the size of the specimens used is missing.

  4. Enhanced Pixel-Driving Circuits for Active-Matrix Organic-Light-Emitting Diode Displays with Large Sizes

    Science.gov (United States)

    Yu, Sang Ho; Choi, Sung Wook; Shin, Hong Jae; Kwack, Kae Dal; Kim, Tae Whan

    2005-03-01

    Enhanced pixel-driving circuits for active-matrix organic-light-emitting diode (AM-OLED) displays with large sizes and highly uniform brightnesses were designed for system on panel. The driving method used the pre-charge functions of the data for a highly uniform brightness during a short time to program the current. The currents of the designed pixel-driving circuits were not significantly affected by variations in the threshold voltages, or by the mobilities of the driving thin-film transistors. These results indicate that the proposed pixel-driving circuits hold promise for potential applications in AM-OLED displays with large sizes and highly uniform brightnesses.

  5. Illusions of having small or large invisible bodies influence visual perception of object size

    OpenAIRE

    Björn van der Hoort; H Henrik Ehrsson

    2016-01-01

    The size of our body influences the perceived size of the world so that objects appear larger to children than to adults. The mechanisms underlying this effect remain unclear. It has been difficult to dissociate visual rescaling of the external environment based on an individual’s visible body from visual rescaling based on a central multisensory body representation. To differentiate these potential causal mechanisms, we manipulated body representation without a visible body by taking advanta...

  6. Prey size and availability limits maximum size of rainbow trout in a large tailwater: insights from a drift-foraging bioenergetics model

    Science.gov (United States)

    Dodrill, Michael J.; Yackulic, Charles B.; Kennedy, Theodore A.; Haye, John W

    2016-01-01

    The cold and clear water conditions present below many large dams create ideal conditions for the development of economically important salmonid fisheries. Many of these tailwater fisheries have experienced declines in the abundance and condition of large trout species, yet the causes of these declines remain uncertain. Here, we develop, assess, and apply a drift-foraging bioenergetics model to identify the factors limiting rainbow trout (Oncorhynchus mykiss) growth in a large tailwater. We explored the relative importance of temperature, prey quantity, and prey size by constructing scenarios where these variables, both singly and in combination, were altered. Predicted growth matched empirical mass-at-age estimates, particularly for younger ages, demonstrating that the model accurately describes how current temperature and prey conditions interact to determine rainbow trout growth. Modeling scenarios that artificially inflated prey size and abundance demonstrate that rainbow trout growth is limited by the scarcity of large prey items and overall prey availability. For example, shifting 10% of the prey biomass to the 13 mm (large) length class, without increasing overall prey biomass, increased lifetime maximum mass of rainbow trout by 88%. Additionally, warmer temperatures resulted in lower predicted growth at current and lower levels of prey availability; however, growth was similar across all temperatures at higher levels of prey availability. Climate change will likely alter flow and temperature regimes in large rivers with corresponding changes to invertebrate prey resources used by fish. Broader application of drift-foraging bioenergetics models to build a mechanistic understanding of how changes to habitat conditions and prey resources affect growth of salmonids will benefit management of tailwater fisheries.

  7. Finite Size Corrections to the Large Deviation Function of the Density in the One Dimensional Symmetric Simple Exclusion Process

    Science.gov (United States)

    Derrida, Bernard; Retaux, Martin

    2013-09-01

    The symmetric simple exclusion process is one of the simplest out-of-equilibrium systems for which the steady state is known. Its large deviation functional of the density has been computed in the past both by microscopic and macroscopic approaches. Here we obtain the leading finite size correction to this large deviation functional. The result is compared to the similar corrections for equilibrium systems.

  8. Influence of phantom size on output, peak scatter factor, and percentage depth dose in large-field photon irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Podgorsak, E.B.; Pla, C.; Evans, M.D.C.; Pla, M.

    1985-09-01

    Machine outputs, peak scatter factors, and central axis percentage depth dose distributions were measured for various phantom sizes in large radiation fields produced at extended distances by cobalt, 6-MV, and 10-MV photon beams. The results can be applied to practical total body irradiation procedures which usually involve treatment volumes smaller than the actual field sizes in order to provide a uniform total body exposure to radiation. Our study addresses the question of the appropriate phantom dimension to be used in the calibration of photon beams employed in total body irradiations. The measurements show that the machine outputs are only slightly dependent on phantom size; the percentage depth dose distributions, however, are strongly dependent on the phantom size, suggesting that machine data for total body irradiations should be measured in phantoms whose dimensions approximate the patient during the total body irradiation. Peak scatter factors measured in large-field/small-phantom configurations link up well with the published small-field/large-phantom data. The finite patient thickness lowers the dose to points close to the beam exit surface by a few percent, when compared to dose measured at the same depths in infinitely thick phantoms. The surface doses in large radiation fields are essentially independent of phantom cross sections and range from 40% for the 10-MV beam, to 65% for the 6-MV beam and 80% for the cobalt beam.

  9. 78 FR 32865 - Procedures To Establish Appropriate Minimum Block Sizes for Large Notional Off-Facility Swaps and...

    Science.gov (United States)

    2013-05-31

    ... and Lasse Heje Pedersen, Predatory Trading, Journal of Finance LX 4, Aug. 2005, available at http... Notional Amount Calculation VIII. List of Commenters Who Responded to the Further Block Proposal I... Establish Appropriate Minimum Block Sizes for Large Notional Off-Facility Swaps and Block Trades, 77 FR...

  10. Perception of Business Studies Teachers on the Infuence of Large Class Size in Public Secondary Schools in Yobe State, Nigeria

    Science.gov (United States)

    Mamman, Jummai; Chadi, Aishatu Mohammad; Jirgi, Ibrahim

    2015-01-01

    This is a survey study conducted to determine the perception of business studies teacher's on the influence of large class size in Yobe state public secondary school. Three research questions were raised to guide the study. The population comprised of one hundred and twenty (120) business studies teachers from one hundred and five (105) Secondary…

  11. Size-resolved aerosol chemical analysis of extreme haze pollution events during early 2013 in urban Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Shili; Pan, Yuepeng, E-mail: panyuepeng@mail.iap.ac.cn; Liu, Zirui; Wen, Tianxue; Wang, Yuesi, E-mail: wys@mail.iap.ac.cn

    2014-08-30

    Highlights: • Anthropogenic species substantially accumulated in both fine and coarse particles. • Secondary organic carbon in PM{sub 1.1} decreased from clear to haze days. • The mass peak shifted to larger particles from clear to haze days. • The NO{sub 3}{sup −}/SO{sub 4}{sup 2−} ratio decreased with enhanced haze pollution. • Both mobile local and stationary regional sources were vital for haze formation. - Abstract: Using size-resolved filter sampling and chemical characterization, high concentrations of water-soluble ions, carbonaceous species and heavy metals were found in both fine (PM{sub 2.1}) and coarse (PM{sub 2.1–9}) particles in Beijing during haze events in early 2013. Even on clear days, average mass concentration of submicron particles (PM{sub 1.1}) was several times higher than that previously measured in most of abroad urban areas. A high concentration of particulate matter on haze days weakens the incident solar radiation, which reduces the generation rate of secondary organic carbon in PM{sub 1.1}. We show that the peak mass concentration of particles shifted from 0.43–0.65 μm on clear days to 0.65–1.1 μm on lightly polluted days and to 1.1–2.1 μm on heavily polluted days. The peak shifts were also found for the following species: organic carbon, elemental carbon, NH{sub 4}{sup +}, SO{sub 4}{sup 2−}, NO{sub 3}{sup −}, K, Cu, Zn, Cd and Pb. Our findings demonstrate that secondary inorganic aerosols (36%) and organic matter (26%) dominated the fine particle mass on heavily polluted days, while their contribution reduced to 29% and 18%, respectively, on clear days. Besides fine particles, anthropogenic chemical species also substantially accumulated in the coarse mode, which suggests that particles with aerodynamic diameter larger than 2.1 μm cannot be neglected during severe haze events.

  12. Large group size yields group stability in the cooperatively breeding cichlid Neolamprologus pulcher

    NARCIS (Netherlands)

    Heg, D; Bachar, Z; Taborsky, M

    2005-01-01

    Group size has been shown to positively influence survival of group members in many cooperatively breeding vertebrates, including the Lake Tanganyika cichlid Neolamprologus pulcher, suggesting Allee effects. However, long-term data are scarce to test how these survival differences translate into cha

  13. Occupational lifting during pregnancy and child's birth size in a large cohort study

    DEFF Research Database (Denmark)

    Juhl, Mette; Larsen, Pernille Stemann; Andersen, Per Kragh

    2014-01-01

    OBJECTIVES: It has been suggested that the handling of heavy loads during pregnancy is associated with impaired fetal growth. We examined the association between quantity and frequency of maternal occupational lifting and the child's size at birth, measured by weight, length, ponderal index, small...

  14. Job Stress in the United Kingdom: Are Small and Medium-Sized Enterprises and Large Enterprises Different?

    Science.gov (United States)

    Lai, Yanqing; Saridakis, George; Blackburn, Robert

    2015-08-01

    This paper examines the relationships between firm size and employees' experience of work stress. We used a matched employer-employee dataset (Workplace Employment Relations Survey 2011) that comprises of 7182 employees from 1210 private organizations in the United Kingdom. Initially, we find that employees in small and medium-sized enterprises experience lower level of overall job stress than those in large enterprises, although the effect disappears when we control for individual and organizational characteristics in the model. We also find that quantitative work overload, job insecurity and poor promotion opportunities, good work relationships and poor communication are strongly associated with job stress in the small and medium-sized enterprises, whereas qualitative work overload, poor job autonomy and employee engagements are more related with larger enterprises. Hence, our estimates show that the association and magnitude of estimated effects differ significantly by enterprise size. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Separation of large DNA molecules by size exclusion chromatography-based microchip with on-chip concentration structure

    Science.gov (United States)

    Azuma, Naoki; Itoh, Shintaro; Fukuzawa, Kenji; Zhang, Hedong

    2016-06-01

    The separation of DNA molecules according to their size represents a fundamental bioanalytical procedure. Here, we report the development of a chip-sized device, consisting of micrometer-sized fence structures fabricated in a microchannel, for the separation of large DNA molecules (over 10 kbp) based on the principle of size exclusion chromatography (SEC). In order to achieve separation, two approaches were utilized: first, the DNA samples were concentrated immediately prior to separation using nanoslit structures, with the aim of improving the resolution. Second, a theoretical model of SEC-based separation was established and applied in order to predict the optimal voltage range for separation. In this study, we achieved separation of λ DNA (48.5 kbp) and T4 DNA (166 kbp) using the present SEC-based microchip.

  16. Extremely large anthropogenic-aerosol contribution to total aerosol load over the Bay of Bengal during winter season

    Directory of Open Access Journals (Sweden)

    D. G. Kaskaoutis

    2011-07-01

    Full Text Available Ship-borne observations of spectral aerosol optical depth (AOD have been carried out over the entire Bay of Bengal (BoB as part of the W-ICARB cruise campaign during the period 27 December 2008–30 January 2009. The results reveal a pronounced temporal and spatial variability in the optical characteristics of aerosols mainly due to anthropogenic emissions and their dispersion controlled by local meteorology. The highest aerosol amount, with mean AOD500>0.4, being even above 1.0 on specific days, is found close to the coastal regions in the western and northern parts of BoB. In these regions the Ångström exponent is also found to be high (~1.2–1.25 indicating transport of strong anthropogenic emissions from continental regions, while very high AOD500 (0.39±0.07 and α380–870 values (1.27±0.09 are found over the eastern BoB. Except from the large α380–870 values, an indication of strong fine-mode dominance is also observed from the AOD curvature, which is negative in the vast majority of the cases, suggesting dominance of an anthropogenic-pollution aerosol type. On the other hand, clean maritime conditions are rather rare over the region, while the aerosol types are further examined through a classification scheme based on the relationship between α and dα. It was found that even for the same α values the fine-mode dominance is larger for higher AODs showing the strong continental influence over the marine environment of BoB. Furthermore, there is also an evidence of aerosol-size growth under more turbid conditions indicative of coagulation and/or humidification over specific BoB regions. The results obtained using OPAC model show significant fraction of soot aerosols (~6 %–8 % over the eastern and northwestern BoB, while coarse-mode sea salt particles are found to dominate in the southern parts of BoB.

  17. The maximum sizes of large scale structures in alternative theories of gravity

    CERN Document Server

    Bhattacharya, Sourav; Romano, Antonio Enea; Skordis, Constantinos; Tomaras, Theodore N

    2016-01-01

    The maximum size of a cosmic structure is given by the maximum turnaround radius -- the scale where the attraction due to its mass is balanced by the repulsion due to dark energy. We derive generic formulas for the estimation of the maximum turnaround radius in any theory of gravity obeying the Einstein equivalence principle, in two situations: on a spherically symmetric spacetime and on a perturbed Friedman-Robertson-Walker spacetime. We show that the two formulas agree. As an application of our formula, we calculate the maximum turnaround radius in the case of the Brans-Dicke theory of gravity. We find that for this theory, such maximum sizes always lie above the $\\Lambda$CDM value, by a factor $1 + \\frac{1}{3\\omega}$, where $\\omega\\gg 1$ is the Brans-Dicke parameter, implying consistency of the theory with current data.

  18. Direct Solve of Electrically Large Integral Equations for Problem Sizes to 1M Unknowns

    Science.gov (United States)

    Shaeffer, John

    2008-01-01

    Matrix methods for solving integral equations via direct solve LU factorization are presently limited to weeks to months of very expensive supercomputer time for problems sizes of several hundred thousand unknowns. This report presents matrix LU factor solutions for electromagnetic scattering problems for problem sizes to one million unknowns with thousands of right hand sides that run in mere days on PC level hardware. This EM solution is accomplished by utilizing the numerical low rank nature of spatially blocked unknowns using the Adaptive Cross Approximation for compressing the rank deficient blocks of the system Z matrix, the L and U factors, the right hand side forcing function and the final current solution. This compressed matrix solution is applied to a frequency domain EM solution of Maxwell's equations using standard Method of Moments approach. Compressed matrix storage and operations count leads to orders of magnitude reduction in memory and run time.

  19. Highly crystallized nanometer-sized zeolite a with large Cs adsorption capability for the decontamination of water.

    Science.gov (United States)

    Torad, Nagy L; Naito, Masanobu; Tatami, Junichi; Endo, Akira; Leo, Sin-Yen; Ishihara, Shinsuke; Wu, Kevin C-W; Wakihara, Toru; Yamauchi, Yusuke

    2014-03-01

    Nanometer-sized zeolite A with a large cesium (Cs) uptake capability is prepared through a simple post-milling recrystallization method. This method is suitable for producing nanometer-sized zeolite in large scale, as additional organic compounds are not needed to control zeolite nucleation and crystal growth. Herein, we perform a quartz crystal microbalance (QCM) study to evaluate the uptake ability of Cs ions by zeolite, to the best of our knowledge, for the first time. In comparison to micrometer-sized zeolite A, nanometer-sized zeolite A can rapidly accommodate a larger amount of Cs ions into the zeolite crystal structure, owing to its high external surface area. Nanometer-sized zeolite is a promising candidate for the removal of radioactive Cs ions from polluted water. Our QCM study on Cs adsorption uptake behavior provides the information of adsorption kinetics (e.g., adsorption amounts and rates). This technique is applicable to other zeolites, which will be highly valuable for further consideration of radioactive Cs removal in the future.

  20. Spatiotemporal Chaos in Large Systems The Scaling of Complexity with Size

    CERN Document Server

    Greenside, H S

    1996-01-01

    The dynamics of a nonequilibrium system can become complex because the system has many components (e.g., a human brain), because the system is strongly driven from equilibrium (e.g., large Reynolds-number flows), or because the system becomes large compared to certain intrinsic length scales. Recent experimental and theoretical work is reviewed that addresses this last route to complexity. In the idealized case of a sufficiently large, nontransient, homogeneous, and chaotic system, the fractal dimension D becomes proportional to the system's volume V which defines the regime of extensive chaos. The extensivity of the fractal dimension suggests a new way to characterize correlations in high-dimensional systems in terms of an intensive dimension correlation length $\\xi_\\delta$. Recent calculations at Duke University show that $\\xi_\\delta$ is a length scale smaller than and independent of some commonly used measures of disorder such as the two-point and mutual-information correlation lengths. Identifying the bas...

  1. Large sample area and size are needed for forest soil seed bank studies to ensure low discrepancy with standing vegetation.

    Directory of Open Access Journals (Sweden)

    You-xin Shen

    Full Text Available A large number of small-sized samples invariably shows that woody species are absent from forest soil seed banks, leading to a large discrepancy with the seedling bank on the forest floor. We ask: 1 Does this conventional sampling strategy limit the detection of seeds of woody species? 2 Are large sample areas and sample sizes needed for higher recovery of seeds of woody species? We collected 100 samples that were 10 cm (length × 10 cm (width × 10 cm (depth, referred to as larger number of small-sized samples (LNSS in a 1 ha forest plot, and placed them to germinate in a greenhouse, and collected 30 samples that were 1 m × 1 m × 10 cm, referred to as small number of large-sized samples (SNLS and placed them (10 each in a nearby secondary forest, shrub land and grass land. Only 15.7% of woody plant species of the forest stand were detected by the 100 LNSS, contrasting with 22.9%, 37.3% and 20.5% woody plant species being detected by SNLS in the secondary forest, shrub land and grassland, respectively. The increased number of species vs. sampled areas confirmed power-law relationships for forest stand, the LNSS and SNLS at all three recipient sites. Our results, although based on one forest, indicate that conventional LNSS did not yield a high percentage of detection for woody species, but SNLS strategy yielded a higher percentage of detection for woody species in the seed bank if samples were exposed to a better field germination environment. A 4 m2 minimum sample area derived from power equations is larger than the sampled area in most studies in the literature. Increased sample size also is needed to obtain an increased sample area if the number of samples is to remain relatively low.

  2. Optimal Siting and Sizing of Energy Storage System for Power Systems with Large-scale Wind Power Integration

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun

    2015-01-01

    This paper proposes algorithms for optimal sitingand sizing of Energy Storage System (ESS) for the operationplanning of power systems with large scale wind power integration.The ESS in this study aims to mitigate the wind powerfluctuations during the interval between two rolling Economic...... optimal siting and sizing of storage units throughoutthe network. These questions are investigated using an IEEE benchmark system......Dispatches (EDs) in order to maintain generation-load balance.The charging and discharging of ESS is optimized consideringoperation cost of conventional generators, capital cost of ESSand transmission losses. The statistics from simulated systemoperations are then coupled to the planning process to determinethe...

  3. Early outcome in renal transplantation from large donors to small and size-matched recipients - a porcine experimental model

    DEFF Research Database (Denmark)

    Ravlo, Kristian; Chhoden, Tashi; Søndergaard, Peter

    2012-01-01

    Kidney transplantation from a large donor to a small recipient, as in pediatric transplantation, is associated with an increased risk of thrombosis and DGF. We established a porcine model for renal transplantation from an adult donor to a small or size-matched recipient with a high risk of DGF...... and studied GFR, RPP using MRI, and markers of kidney injury within 10 h after transplantation. After induction of BD, kidneys were removed from ∼63-kg donors and kept in cold storage for ∼22 h until transplanted into small (∼15 kg, n = 8) or size-matched (n = 8) recipients. A reduction in GFR was observed...

  4. Innovative capabilities, firm performance and foreign ownership: Empirical analysis of large and medium-sized companies form all industries

    Directory of Open Access Journals (Sweden)

    Anita Talaja

    2013-10-01

    Full Text Available In this article innovative capability, i.e. the ability of new products and markets development, is analyzed and empirically tested. The results have proven that the companies with more developed innovative capabilities achieve higher performance levels, but that there is no difference in innovative capabilities between large and medium-sized companies. On the other hand, medium-sized companies have slightly higher levels of sales growth and increase in market share. Also, companies in foreign ownership are better at development of new products and new production methods, and they have higher levels of sales growth, market share and increase in market share.

  5. Small genomes and large seeds: chromosome numbers, genome size and seed mass in diploid Aesculus species (Sapindaceae).

    Science.gov (United States)

    Krahulcová, Anna; Trávnícek, Pavel; Krahulec, František; Rejmánek, Marcel

    2017-04-01

    Aesculus L. (horse chestnut, buckeye) is a genus of 12-19 extant woody species native to the temperate Northern Hemisphere. This genus is known for unusually large seeds among angiosperms. While chromosome counts are available for many Aesculus species, only one has had its genome size measured. The aim of this study is to provide more genome size data and analyse the relationship between genome size and seed mass in this genus. Chromosome numbers in root tip cuttings were confirmed for four species and reported for the first time for three additional species. Flow cytometric measurements of 2C nuclear DNA values were conducted on eight species, and mean seed mass values were estimated for the same taxa. The same chromosome number, 2 n = 40, was determined in all investigated taxa. Original measurements of 2C values for seven Aesculus species (eight taxa), added to just one reliable datum for A. hippocastanum , confirmed the notion that the genome size in this genus with relatively large seeds is surprisingly low, ranging from 0·955 pg 2C -1 in A. parviflora to 1·275 pg 2C -1 in A. glabra var. glabra. The chromosome number of 2 n = 40 seems to be conclusively the universal 2 n number for non-hybrid species in this genus. Aesculus genome sizes are relatively small, not only within its own family, Sapindaceae, but also within woody angiosperms. The genome sizes seem to be distinct and non-overlapping among the four major Aesculus clades. These results provide an extra support for the most recent reconstruction of Aesculus phylogeny. The correlation between the 2C values and seed masses in examined Aesculus species is slightly negative and not significant. However, when the four major clades are treated separately, there is consistent positive association between larger genome size and larger seed mass within individual lineages.

  6. A hybrid adaptive large neighborhood search algorithm applied to a lot-sizing problem

    DEFF Research Database (Denmark)

    Muller, Laurent Flindt; Spoorendonk, Simon

    This paper presents a hybrid of a general heuristic framework that has been successfully applied to vehicle routing problems and a general purpose MIP solver. The framework uses local search and an adaptive procedure which choses between a set of large neighborhoods to be searched. A mixed integer...

  7. Magnetomotive forming for precision sizing and joining of large-diameter tubes

    Science.gov (United States)

    Bennight, J. D.; Schwinghamer, R. J.

    1969-01-01

    Portable electromagnetic coil enables high precision expansion or constriction and joining of large diameter metal tubes. A nonconducting mandrel or forming die is used on the side of the tubes wall opposite the coil. The coil is insulated from the tube by a thin plastic sleeve.

  8. Participation and Collaborative Learning in Large Class Sizes: Wiki, Can You Help Me?

    Science.gov (United States)

    de Arriba, Raúl

    2017-01-01

    Collaborative learning has a long tradition within higher education. However, its application in classes with a large number of students is complicated, since it is a teaching method that requires a high level of participation from the students and careful monitoring of the process by the educator. This article presents an experience in…

  9. Preventing large birth size in women with preexisting diabetes mellitus: The benefit of appropriate gestational weight gain

    Science.gov (United States)

    Kim, Shin Y.; Sharma, Andrea J.; Sappenfield, William; Salihu, Hamisu M.

    2016-01-01

    Objective To estimate the percentage of infants with large birth size attributable to excess gestational weight gain (GWG), independent of prepregnancy body mass index, among mothers with preexisting diabetes mellitus (PDM). Study design We analyzed 2004–2008 Florida linked birth certificate and maternal hospital discharge data of live, term (37–41 weeks) singleton deliveries (N = 641,857). We calculated prevalence of large-for-gestational age (LGA) (birth weight-for-gestational age ≥ 90th percentile) and macrosomia (birth weight > 4500 g) by GWG categories (inadequate, appropriate, or excess). We used multivariable logistic regression to estimate the relative risk (RR) of large birth size associated with excess compared to appropriate GWG among mothers with PDM. We then estimated the population attributable fraction (PAF) of large birth size due to excess GWG among mothers with PDM (n = 4427). Results Regardless of diabetes status, half of mothers (51.2%) gained weight in excess of recommendations. Large birth size was higher in infants of mothers with PDM than in infants of mothers without diabetes (28.8% versus 9.4% for LGA, 5.8% versus 0.9% for macrosomia). Among women with PDM, the adjusted RR of having an LGA infant was 1.7 (95% CI 1.5, 1.9) for women with excess GWG compared to those with appropriate gain; the PAF was 27.7% (95% CI 22.0, 33.3). For macrosomia, the adjusted RR associated with excess GWG was 2.1 (95% CI 1.5, 2.9) and the PAF was 38.6% (95% CI 24.9, 52.4). Conclusion Preventing excess GWG may avert over one-third of macrosomic term infants of mothers with PDM. Effective strategies to prevent excess GWG are needed. PMID:27539071

  10. A Projection of Changes in Landfilling Atmospheric River Frequency and Extreme Precipitation over Western North America from the Large Ensemble CESM Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hagos, Samson M.; Leung, Lai-Yung R.; Yoon, Jin-Ho; Lu, Jian; Gao, Yang

    2016-02-06

    Simulations from the Community Earth System Model Large Ensemble project are analyzed to investigate the impact of global warming on atmospheric rivers (ARs). The model has notable biases in simulating the subtropical jet position and the relationship between extreme precipitation and moisture transport. After accounting for these biases, the model projects an ensemble mean increase of 35% in the number of landfalling AR days between the last twenty years of the 20th and 21st centuries. However, the number of AR associated extreme precipitation days increases only by 28% because the moisture transport required to produce extreme precipitation also increases with warming. Internal variability introduces an uncertainty of ±8% and ±7% in the projected changes in AR days and associated extreme precipitation days. In contrast, accountings for model biases only change the projected changes by about 1%. The significantly larger mean changes compared to internal variability and to the effects of model biases highlight the robustness of AR responses to global warming.

  11. Mapping trends of large and medium size carnivores of conservation interest in Romania

    Directory of Open Access Journals (Sweden)

    Mihai Cristian Adamescu

    2014-07-01

    Full Text Available We analysed yearly estimates of population size data during 2001-2012 for five carnivores species of conservation interest (Ursus arctos, Canis lupus, Lynx lynx, Felis silvestris and Canis aureus. Population size estimations were done by the game management authorities and integrated by the competent authorities on the Ministry of Environment and Climate Change. Trends in data were detected using non-parametric Mann-Kendall test. This test was chosen considering the short length of data series and its usefulness for non-normal distributed data. The trend was tested at three spatial scales: game management units (n=1565, biogeographical region (n=5 and national. Trends depicted for each game management unit were plotted using ArcGIS, resulting species trend distribution maps. For the studied period increasing population trends were observed for Ursus arctos, Canis lupus, Canis aureus and Lynx lynx, while for Felis silvestris there was no trend recorded. Such an analysis in especially useful for conservation proposes, game management and reporting obligations under article 17 of the EC Habitat Directive, using population trend as a proxy for population dynamics. We conclude that the status of the five carnivore species is favourable during the study period.

  12. Characterization of large size YBa2Cu3O7-δ films using magnetic field penetration

    Science.gov (United States)

    Almog, B.; Azoulay, M.; Castro, H.; Deutscher, G.

    2005-11-01

    High critical current density (jc) is one of the most important properties of high Tc superconducting thin films. Determining it is difficult especially in large films (2-3 inch). We propose a non-destructive and easy technique for measuring jc. From measurements of the magnetic moment in the middle of a superconducting film as a function of the external magnetic field, we calculate the macroscopic critical current density.

  13. Diversity of medium and large sized mammals in a Cerrado fragment of central Brazil

    Directory of Open Access Journals (Sweden)

    F.S. Campos

    2013-11-01

    Full Text Available Studies related to community ecology of medium and large mammals represent a priority in developing strategies for conservation of their habitats. Due to the significant ecological importance of these species, a concern in relation to anthropogenic pressures arises since their populations are vulnerable to hunting and fragmentation. In this study, we aimed to analyze the diversity of medium and large mammals in a representative area of the Cerrado biome, located in the National Forest of Silvânia, central Brazil, providing insights for future studies on the biodiversity and conservation of Cerrado mammals. Sampling was carried out by linear transects, search for traces, footprint traps and camera traps. We recorded 23 species, among which three are listed in threat categories (e.g., Myrmecophaga tridactyla, Chrysocyon brachyurus and Leopardus tigrinus. We registered 160 records in the study area, where the most frequently recorded species were Didelphis albiventris (30 records and Cerdocyon thous (28 records. Our results indicated that a small protected area of Cerrado can include a large and important percentage of the diversity of mammals in this biome, providing information about richness, abundance, spatial distribution and insights for future studies on the biodiversity and conservation of these biological communities.

  14. Dynamic globularization prediction during cogging process of large size TC11 titanium alloy billet with lamellar structure

    Institute of Scientific and Technical Information of China (English)

    Hong-wu SONG; Shi-hong ZHANG; Ming CHENG

    2014-01-01

    The flow behavior and dynamic globularization of TC11 titanium alloy during subtransus deformation are investigated through hot compression tests. A constitutive model is established based on physical-based hardening model and phenomenological softening model. And based on the recrystallization mechanisms of globularization, the Avrami type kinetics model is established for prediction of globularization fraction and globularized grain size under large strain subtransus deformation of TC11 alloy. As the preliminary application of the previous results, the cogging process of large size TC11 alloy billet is simulated. Based on subroutine development of the DEFORM software, the coupled simulation of one fire cogging process is developed. It shows that the predicted results are in good agreement with the experimental results in forging load and microstructure characteristic, which validates the reliability of the developed FEM subroutine models.

  15. Large Size GEM for Super Bigbite Spectrometer (SBS) Polarimeter for Hall A 12 GeV program at JLab

    CERN Document Server

    Gnanvo, Kondo; Nelyubin, Vladimir; Saenboonruang, Kiadtisak; Sacher, Seth; Wojtsekhowski, Bogdan

    2014-01-01

    We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as well as the preliminary results on performances from tests carried out in our detector lab and with test beams at Fermilab.

  16. Salt-assisted direct exfoliation of graphite into high-quality, large-size, few-layer graphene sheets.

    Science.gov (United States)

    Niu, Liyong; Li, Mingjian; Tao, Xiaoming; Xie, Zhuang; Zhou, Xuechang; Raju, Arun P A; Young, Robert J; Zheng, Zijian

    2013-08-21

    We report a facile and low-cost method to directly exfoliate graphite powders into large-size, high-quality, and solution-dispersible few-layer graphene sheets. In this method, aqueous mixtures of graphite and inorganic salts such as NaCl and CuCl2 are stirred, and subsequently dried by evaporation. Finally, the mixture powders are dispersed into an orthogonal organic solvent solution of the salt by low-power and short-time ultrasonication, which exfoliates graphite into few-layer graphene sheets. We find that the as-made graphene sheets contain little oxygen, and 86% of them are 1-5 layers with lateral sizes as large as 210 μm(2). Importantly, the as-made graphene can be readily dispersed into aqueous solution in the presence of surfactant and thus is compatible with various solution-processing techniques towards graphene-based thin film devices.

  17. Heritabilities and genetic correlations for litter size and semen traits in Czech Large White and Landrace pigs.

    Science.gov (United States)

    Wolf, J

    2010-09-01

    The objective of the present study was to estimate heritabilities and genetic correlations for semen and litter size traits using full animal model analyses. Litter size data were available from 28,485 Czech Large White and 10,410 Czech Landrace sows farrowing between 1995 and 2008. The number of litter records was 91,922 and 30,937, respectively. Records on semen traits (37,137 ejaculates from 778 Large White boars and 51,341 ejaculates from 841 Landrace boars) were available from 22 AI centers in the Czech Republic from 2000 to 2009. All calculations were carried out separately for each breed. Number of functional sperm was defined as total number of sperm times the fraction of motile sperm times (1 - the fraction of abnormal sperm). Among the semen traits, semen volume showed the greatest heritability (0.20 +/- 0.019 in Large White and 0.25 +/- 0.018 in Landrace), followed by sperm concentration with a heritability of 0.18 (SE = 0.012 and 0.014) in both breeds. The heritabilities of the remaining 4 traits (motility, percentage of abnormal sperm, total number of sperm, and number of functional sperm) were around 0.10 (SE = 0.016 to 0.031). Large negative genetic correlations were observed between semen volume and sperm concentration and between motility and percentage of abnormal sperm, especially in Large White. Positive and negative correlations among remaining semen traits were mostly of small magnitude. There was a tendency for increasing litter size to be associated with slight decreases in the total number of sperm and in the number of functional sperm, especially in the Large White breed (genetic correlations of -0.08 to -0.14 and -0.16 to -0.31, respectively, with SE between 0.100 and 0.114). Some of the correlations between semen and litter size traits (especially with the percentage of abnormal sperm) were breed-specific (positive up to 0.63 +/- 0.062 for Large White and negative until -0.41 +/- 0.106 in Landrace). Furthermore, parity

  18. Large-Sized Dye-Sensitized Solar Cells with TiO2 Cemented and Protected Silver Grids

    Science.gov (United States)

    Lan, Zhang; Wu, Jihuai; Lin, Jianming; Miaoliang

    2012-03-01

    Large-sized dye-sensitized solar cells were prepared with TiO2 cemented and protected Ag grids in the photo and counter electrodes. The addition of high conductive TiO2 cemented Ag grids can maintain high performance with the enlargement of the cells. The preparation of the compact TiO2 layer on the Ag grids can prevent the corrosion of the electrolyte, moreover, when it is prepared on the whole area of the photo electrode, it also can play as the blocking layer for further enhancing the performance of cells. The presented method shows a simple and efficient way to prepare high performance large single cells.

  19. In-Class Extensive Reading Activity to Assist Self-Paced Learning in a Large Class-Size Environment

    OpenAIRE

    鬼田, 崇作

    2013-01-01

    The purpose of this paper is to show the effects an extensive reading activity had in assisting students in a self-paced learning, large class-size English environment. As the student body was diverse, encompassing varying levels of ability, learning styles, interests and proficiency, it is essential that teachers pay attention to these differences and adapt the materials to each learner's individual differences. However, it is difficult for a teacher to satisfy all of their individual studen...

  20. A method of manufacturing process modeling based on activity network for large-sized and complex products

    Institute of Scientific and Technical Information of China (English)

    LV Min; TONG Zhen-bo; WANG Gang

    2008-01-01

    Simulation technique is an efficient approach to realize the planning and scheduling of manufacturing process of products. An appropriate and efficient manufacturing process model is the basis and key of manufac-turing process simulation. By analyzing the features of large-sized and complex products, a method of manufac-turing process modeling based on activity network is presented and a mapping algorithm of translating BOM/ BOP into the manufacturing process model is designed in detail.

  1. Hypopigmentation Induced by Frequent Low-Fluence, Large-Spot-Size QS Nd:YAG Laser Treatments

    OpenAIRE

    Wong, Yisheng; Lee, Siong See Joyce; Goh, Chee Leok

    2015-01-01

    The Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (QS 1064-nm Nd:YAG) laser is increasingly used for nonablative skin rejuvenation or "laser toning" for melasma. Multiple and frequent low-fluence, large-spot-size treatments are used to achieve laser toning, and these treatments are associated with the development of macular hypopigmentation as a complication. We present a case series of three patients who developed guttate hypomelanotic macules on the face after receiving laser t...

  2. Highly sensitive visible-blind extreme ultraviolet Ni/4H-SiC Schottky photodiodes with large detection area.

    Science.gov (United States)

    Hu, Jun; Xin, Xiaobin; Zhao, Jian H; Yan, Feng; Guan, Bing; Seely, John; Kjornrattanawanich, Benjawan

    2006-06-01

    Ni/4H-SiC Schottky photodiodes of 5 mm x 5 mm area have been fabricated and characterized. The photodiodes show less than 0.1 pA dark current at -4 V and an ideality factor of 1.06. A quantum efficiency (QE) between 3 and 400 nm has been calibrated and compared with Si photodiodes optimized for extreme ultraviolet (EUV) detection. In the EUV region, the QE of SiC detectors increases from 0.14 electrons/photon at 120 nm to 30 electrons/photon at 3 nm. The mean energy of electron-hole pair generation of 4H-SiC estimated from the spectral QE is found to be 7.9 eV.

  3. A hybrid adaptive large neighborhood search heuristic for lot-sizing with setup times

    DEFF Research Database (Denmark)

    Muller, Laurent Flindt; Spoorendonk, Simon; Pisinger, David

    2012-01-01

    This paper presents a hybrid of a general heuristic framework and a general purpose mixed-integer programming (MIP) solver. The framework is based on local search and an adaptive procedure which chooses between a set of large neighborhoods to be searched. A mixed integer programming solver and its......, and the upper bounds found by the commercial MIP solver ILOG CPLEX using state-of-the-art MIP formulations. Furthermore, we improve the best known solutions on 60 out of 100 and improve the lower bound on all 100 instances from the literature...

  4. Micro powder injection molding——large scale production technology for micro-sized components

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Micro powder injection molding (μPIM),a miniaturized variant of powder injection molding,has advantages of shape complexity,applicability to many materials and good mechanical properties. Co-injection molding has been realized between met-als and ceramics on micro components,which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio,micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or micro-structured components in microsystems technology (MST) field.

  5. Micro powder injection molding-large scale production technology for micro-sized components

    Institute of Scientific and Technical Information of China (English)

    YIN HaiQing; JIA ChengChang; QU XuanHui

    2008-01-01

    Micro powder injection molding (μPIM), a miniaturized variant of powder injection molding, has advantages of shape complexity, applicability to many materials and good mechanical properties. Co-injection molding has been realized between metals and ceramics on micro components, which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio, micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or microstructured components in microsystems technology (MST) field.

  6. Large Size High Performance Transparent Amorphous Silicon Sensors for Laser Beam Position Detection and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A.; Martinez Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto; Alberdi, J.; Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrete, J.; Oller, J. C.; Kohler, C.; Lutz, B.; Schubert, M. B.

    2006-09-04

    We present the measured performance of a new generation of semitransparente amorphous silicon position detectors. They have a large sensitive area (30 x 30 mm2) and show good properties such as a high response (about 20 mA/W), an intinsic position resolution better than 3 m, a spatial point reconstruction precision better than 10 m, deflection angles smaller than 10 rad and a transmission power in the visible and NIR higher than 70%. In addition, multipoint alignment monitoring, using up to five sensors lined along a light path of about 5 meters, can be achieved with a resolution better than 20m. (Author)

  7. Large-size high-performance transparent amorphous silicon sensors for laser beam position detection

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Martinez-Rivero, C. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Matorras, F. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Rodrigo, T. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Vila, I. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Virto, A.L. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Alberdi, J. [CIEMAT, Madrid (Spain); Arce, P. [CIEMAT, Madrid (Spain); Barcala, J.M. [CIEMAT, Madrid (Spain); Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)]. E-mail: antonio.ferrando@ciemat.es; Josa, M.I. [CIEMAT, Madrid (Spain); Luque, J.M. [CIEMAT, Madrid (Spain); Molinero, A. [CIEMAT, Madrid (Spain); Navarrete, J. [CIEMAT, Madrid (Spain); Oller, J.C. [CIEMAT, Madrid (Spain); Yuste, C. [CIEMAT, Madrid (Spain); Koehler, C. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Lutz, B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Schubert, M.B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Werner, J.H. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany)

    2006-09-15

    We present the measured performance of a new generation of semitransparent amorphous silicon position detectors. They have a large sensitive area (30x30mm{sup 2}) and show good properties such as a high response (about 20mA/W), an intrinsic position resolution better than 3{mu}m, a spatial-point reconstruction precision better than 10{mu}m, deflection angles smaller than 10{mu}rad and a transmission power in the visible and NIR higher than 70%.

  8. The halophilic alkalithermophile Natranaerobius thermophilus adapts to multiple environmental extremes using a large repertoire of Na(K)/H antiporters.

    Science.gov (United States)

    Mesbah, Noha M; Cook, Gregory M; Wiegel, Juergen

    2009-10-01

    Natranaerobius thermophilus is an unusual extremophile because it is halophilic, alkaliphilic and thermophilic, growing optimally at 3.5 M Na(+), pH(55 degrees C) 9.5 and 53 degrees C. Mechanisms enabling this tripartite lifestyle are essential for understanding how microorganisms grow under inhospitable conditions, but remain unknown, particularly in extremophiles growing under multiple extremes. We report on the response of N. thermophilus to external pH at high salt and elevated temperature and identify mechanisms responsible for this adaptation. N. thermophilus exhibited cytoplasm acidification, maintaining an unanticipated transmembrane pH gradient of 1 unit over the entire extracellular pH range for growth. N. thermophilus uses two distinct mechanisms for cytoplasm acidification. At extracellular pH values at and below the optimum, N. thermophilus utilizes at least eight electrogenic Na(+)(K(+))/H(+) antiporters for cytoplasm acidification. Characterization of these antiporters in antiporter-deficient Escherichia coli KNabc showed overlapping pH profiles (pH 7.8-10.0) and Na(+) concentrations for activity (K(0.5) values 1.0-4.4 mM), properties that correlate with intracellular conditions of N. thermophilus. As the extracellular pH increases beyond the optimum, electrogenic antiport activity ceases, and cytoplasm acidification is achieved by energy-independent physiochemical effects (cytoplasmic buffering) potentially mediated by an acidic proteome. The combination of these strategies allows N. thermophilus to grow over a range of extracellular pH and Na(+) concentrations and protect biomolecules under multiple extreme conditions.

  9. Dealing with large sample sizes: comparison of a new one spot dot blot method to western blot.

    Science.gov (United States)

    Putra, Sulistyo Emantoko Dwi; Tsuprykov, Oleg; Von Websky, Karoline; Ritter, Teresa; Reichetzeder, Christoph; Hocher, Berthold

    2014-01-01

    Western blot is the gold standard method to determine individual protein expression levels. However, western blot is technically difficult to perform in large sample sizes because it is a time consuming and labor intensive process. Dot blot is often used instead when dealing with large sample sizes, but the main disadvantage of the existing dot blot techniques, is the absence of signal normalization to a housekeeping protein. In this study we established a one dot two development signals (ODTDS) dot blot method employing two different signal development systems. The first signal from the protein of interest was detected by horseradish peroxidase (HRP). The second signal, detecting the housekeeping protein, was obtained by using alkaline phosphatase (AP). Inter-assay results variations within ODTDS dot blot and western blot and intra-assay variations between both methods were low (1.04-5.71%) as assessed by coefficient of variation. ODTDS dot blot technique can be used instead of western blot when dealing with large sample sizes without a reduction in results accuracy.

  10. Bivariate Mixed Effects Analysis of Clustered Data with Large Cluster Sizes.

    Science.gov (United States)

    Zhang, Daowen; Sun, Jie Lena; Pieper, Karen

    2016-10-01

    Linear mixed effects models are widely used to analyze a clustered response variable. Motivated by a recent study to examine and compare the hospital length of stay (LOS) between patients undertaking percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) from several international clinical trials, we proposed a bivariate linear mixed effects model for the joint modeling of clustered PCI and CABG LOS's where each clinical trial is considered a cluster. Due to the large number of patients in some trials, commonly used commercial statistical software for fitting (bivariate) linear mixed models failed to run since it could not allocate enough memory to invert large dimensional matrices during the optimization process. We consider ways to circumvent the computational problem in the maximum likelihood (ML) inference and restricted maximum likelihood (REML) inference. Particularly, we developed an expected and maximization (EM) algorithm for the REML inference and presented an ML implementation using existing software. The new REML EM algorithm is easy to implement and computationally stable and efficient. With this REML EM algorithm, we could analyze the LOS data and obtained meaningful results.

  11. IMPACTS OF OWN BRANDS STRATEGY ON MANUFACTURER – RETAILER RELATIONSHIP: CASE STUDIES IN LARGE SIZE COMPANIES

    Directory of Open Access Journals (Sweden)

    Renato Telles

    2012-05-01

    Full Text Available The study of marketing and production strategy of own brand products requires an understanding of both the benefits gained by retailers and manufacturers involved in this activity and also the effects of this strategy on the relationship between these companies. According to this idea, a qualitative and descriptive work was conducted, based on six case studies, three of them on large product manufacturers and three on large retailers. The aim of this study is defined is threefold: (1 to analyze the expectations of manufacturers and retailers with their own brands’ current operations, (2 to analyze the expectations of manufacturers and retailers with their own brands’ future operations, and (3 to analyze the influence of the own brands adoption on the relationship between manufacturers and retailers. The results indicate that (a current operations are primarily based on economic reasons (market share, and use of spare capacity, (b future operations are perceived from a marketing perspective (survival, and (c the adoption of own brand strategy does not harm the relationship between the parties – both manufacturers and retailers –, unlike the earlier studies indicated.

  12. Large-scale genotyping identifies a new locus at 22q13.2 associated with female breast size.

    Science.gov (United States)

    Li, Jingmei; Foo, Jia Nee; Schoof, Nils; Varghese, Jajini S; Fernandez-Navarro, Pablo; Gierach, Gretchen L; Quek, Swee Tian; Hartman, Mikael; Nord, Silje; Kristensen, Vessela N; Pollán, Marina; Figueroa, Jonine D; Thompson, Deborah J; Li, Yi; Khor, Chiea Chuen; Humphreys, Keith; Liu, Jianjun; Czene, Kamila; Hall, Per

    2013-10-01

    Individual differences in breast size are a conspicuous feature of variation in human females and have been associated with fecundity and advantage in selection of mates. To identify common variants that are associated with breast size, we conducted a large-scale genotyping association meta-analysis in 7169 women of European descent across three independent sample collections with digital or screen film mammograms. The samples consisted of the Swedish KARMA, LIBRO-1 and SASBAC studies genotyped on iCOGS, a custom illumina iSelect genotyping array comprising of 211 155 single nucleotide polymorphisms (SNPs) designed for replication and fine mapping of common and rare variants with relevance to breast, ovary and prostate cancer. Breast size of each subject was ascertained by measuring total breast area (mm(2)) on a mammogram. We confirm genome-wide significant associations at 8p11.23 (rs10086016, p=1.3×10(-14)) and report a new locus at 22q13 (rs5995871, p=3.2×10(-8)). The latter region contains the MKL1 gene, which has been shown to impact endogenous oestrogen receptor α transcriptional activity and is recruited on oestradiol sensitive genes. We also replicated previous genome-wide association study findings for breast size at four other loci. A new locus at 22q13 may be associated with female breast size.

  13. The Caterpillar Project: A Large Suite of Milky Way Sized Halos

    CERN Document Server

    Griffen, Brendan F; Dooley, Gregory A; Gómez, Facundo A; Vogelsberger, Mark; O'Shea, Brian W; Frebel, Anna

    2015-01-01

    We present the largest number of Milky Way sized dark matter halos simulated at very high mass ($\\sim$$10^4$ M$_\\odot$/particle) and temporal resolution ($\\sim$5 Myrs/snapshot) done to date, quadrupling what is currently available in the literature. This initial suite consists of the first 24 halos of the $Caterpillar$ $Project$ (www.caterpillarproject.org) whose project goal of 60 - 70 halos will be made public when complete. We resolve $\\sim$20,000 gravitationally bound subhalos within the virial radius of each host halo. Over the ranges set by our spatial resolution our convergence is excellent and improvements were made upon current state-of-the-art halo finders to better identify substructure at such high resolutions (e.g., on average we recover $\\sim$4 subhalos in each host halo above 10$^8$ M$_\\odot$ which would have otherwise not been found using conventional methods). For our relaxed halos, the inner profiles are reasonably fit by Einasto profiles ($\\alpha$ = 0.169 $\\pm$ 0.023) though this depends on...

  14. Response of the Nevzorov hot wire probe in Arctic clouds dominated by very large droplet sizes

    Directory of Open Access Journals (Sweden)

    A. Schwarzenboeck

    2009-05-01

    Full Text Available During the airborne research mission ASTAR 2004 (Arctic Study of Tropospheric Aerosols, Clouds and Radiation performed over the island of Svalbard in the Arctic a constant-temperature hot-wire Nevzorov Probe designed for aircraft measurements, has been used onboard the aircraft POLAR 2. The Nevzorov probe measured liquid water (LWC and total condensed water content (TWC in supercooled liquid and partly mixed phase clouds, respectively. As for other hotwire probes the calculation of LWC and/or TWC (and thus the ice water content IWC has to take into account the collection efficiencies of the two separate sensors for LWC and TWC which both react differently with respect to cloud phase and what is even more difficult to quantify with respect to the size of ice and liquid cloud particles. The study demonstrates that during pure liquid cloud sequences the ASTAR data set of the Nevzorov probe allowed to improve the quantification of the collection efficiency, particularly of the LWC probe part with respect to water. The improved quantification of liquid water content should lead to improved retrievals of IWC content. Simultaneous retrievals of LWC and IWC are correlated with the asymmetry factor derived from the Polar Nephelometer instrument.

  15. A fast variational Gaussian wavepacket method: size-induced structural transitions in large neon clusters.

    Science.gov (United States)

    Georgescu, Ionuţ; Mandelshtam, Vladimir A

    2011-10-21

    The variational Gaussian wavepacket (VGW) approximation provides an alternative to path integral Monte Carlo for the computation of thermodynamic properties of many-body systems at thermal equilibrium. It provides a direct access to the thermal density matrix and is particularly efficient for Monte Carlo approaches, as for an N-body system it operates in a non-inflated 3N-dimensional configuration space. Here, we greatly accelerate the VGW method by retaining only the relevant short-range correlations in the (otherwise full) 3N × 3N Gaussian width matrix without sacrificing the accuracy of the fully coupled VGW method. This results in the reduction of the original O(N(3)) scaling to O(N(2)). The fast-VGW method is then applied to quantum Lennard-Jones clusters with sizes up to N = 6500 atoms. Following Doye and Calvo [JCP 116, 8307 (2002)] we study the competition between the icosahedral and decahedral structural motifs in Ne(N) clusters as a function of N.

  16. When David beats Goliath: the advantage of large size in interspecific aggressive contests declines over evolutionary time.

    Directory of Open Access Journals (Sweden)

    Paul R Martin

    Full Text Available Body size has long been recognized to play a key role in shaping species interactions. For example, while small species thrive in a diversity of environments, they typically lose aggressive contests for resources with larger species. However, numerous examples exist of smaller species dominating larger species during aggressive interactions, suggesting that the evolution of traits can allow species to overcome the competitive disadvantage of small size. If these traits accumulate as lineages diverge, then the advantage of large size in interspecific aggressive interactions should decline with increased evolutionary distance. We tested this hypothesis using data on the outcomes of 23,362 aggressive interactions among 246 bird species pairs involving vultures at carcasses, hummingbirds at nectar sources, and antbirds and woodcreepers at army ant swarms. We found the advantage of large size declined as species became more evolutionarily divergent, and smaller species were more likely to dominate aggressive contests when interacting with more distantly-related species. These results appear to be caused by both the evolution of traits in smaller species that enhanced their abilities in aggressive contests, and the evolution of traits in larger species that were adaptive for other functions, but compromised their abilities to compete aggressively. Specific traits that may provide advantages to small species in aggressive interactions included well-developed leg musculature and talons, enhanced flight acceleration and maneuverability, novel fighting behaviors, and traits associated with aggression, such as testosterone and muscle development. Traits that may have hindered larger species in aggressive interactions included the evolution of morphologies for tree trunk foraging that compromised performance in aggressive contests away from trunks, and the evolution of migration. Overall, our results suggest that fundamental trade-offs, such as those

  17. A polymer, random walk model for the size-distribution of large DNA fragments after high linear energy transfer radiation

    Science.gov (United States)

    Ponomarev, A. L.; Brenner, D.; Hlatky, L. R.; Sachs, R. K.

    2000-01-01

    DNA double-strand breaks (DSBs) produced by densely ionizing radiation are not located randomly in the genome: recent data indicate DSB clustering along chromosomes. Stochastic DSB clustering at large scales, from > 100 Mbp down to energy transfer (LET) radiation, are obtained. They are found to be non-linear when the dose becomes so large that there is a significant probability of overlapping or close juxtaposition, along one chromosome, for different DSB clusters from different tracks. The non-linearity is more evident for large fragments than for small. The DNAbreak results furnish an example of the RLC (randomly located clusters) analytic formalism, which generalizes the broken-stick fragment-size distribution of the random-breakage model that is often applied to low-LET data.

  18. Hydrological extremes and security

    Science.gov (United States)

    Kundzewicz, Z. W.; Matczak, P.

    2015-04-01

    Economic losses caused by hydrological extremes - floods and droughts - have been on the rise. Hydrological extremes jeopardize human security and impact on societal livelihood and welfare. Security can be generally understood as freedom from threat and the ability of societies to maintain their independent identity and their functional integrity against forces of change. Several dimensions of security are reviewed in the context of hydrological extremes. The traditional interpretation of security, focused on the state military capabilities, has been replaced by a wider understanding, including economic, societal and environmental aspects that get increasing attention. Floods and droughts pose a burden and serious challenges to the state that is responsible for sustaining economic development, and societal and environmental security. The latter can be regarded as the maintenance of ecosystem services, on which a society depends. An important part of it is water security, which can be defined as the availability of an adequate quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risks to people, environments and economies. Security concerns arise because, over large areas, hydrological extremes - floods and droughts - are becoming more frequent and more severe. In terms of dealing with water-related risks, climate change can increase uncertainties, which makes the state's task to deliver security more difficult and more expensive. However, changes in population size and development, and level of protection, drive exposure to hydrological hazards.

  19. Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

    CERN Document Server

    Jeanneau, Fabien; The ATLAS collaboration

    2015-01-01

    Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. In the prototyping towards the final configuration two similar quadruplets with dimensions 1.2×0.5 m2 have been built with the same structure as foreseen for the NSW upgrade. It represents ...

  20. Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

    CERN Document Server

    Jeanneau, Fabien; The ATLAS collaboration

    2015-01-01

    Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. All readout planes are segmented into strips with a pitch of 400 μm for a total of 4096 strips. In two of the four planes the strips are inclined by 1.5 ◦ and provide a measurement of the...

  1. Design and Construction of Large Size Micromegas Chambers for the Upgrade of the ATLAS Muon Spectrometer

    CERN Document Server

    Lösel, Philipp

    2015-01-01

    Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about $\\mathbf{150~m^2}$ of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each layer covers more than $\\mathbf{2~m^2}$ for a total active area of $\\mathbf{1200~m^2}$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15$\\mathbf{\\%}$ transverse momentum resolution for $\\mathbf{1~TeV}$ muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as $\\mathbf{30~\\mu m}$ along the precision coordinate and $\\mathbf{80~\\mu m}$ perpendicular to the chamber. The design and construction procedure of the Micromegas modules will be presented, as well as the design for the assembly ...

  2. Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

    CERN Document Server

    Losel, Philipp Jonathan; The ATLAS collaboration

    2014-01-01

    Large area Micromegas detectors will be employed fo r the first time in high-energy physics experiments. A total surface of about 150 m$^2$ of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resol ution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical prec ision of each plane of the assembled module must be as good as 30 $\\mu$m along the precision coordi nate and 80 $\\mu$m perpendicular to the chamber. The design and construction procedure of the microm egas modules will be presented, as well as the design for the assembly of modules onto the New Small Wheel. Emphasis wi...

  3. Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

    CERN Document Server

    Jeanneau, Fabien; The ATLAS collaboration

    2016-01-01

    Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface area of about 150 m$^2$ of the forward regions (pseudo-rapidity coverage -- 1.3 $\\boldsymbol{< |\\eta| <}$ 2.7) of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels (NSW), which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15\\% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic position resolution, the mechanical precision of each plane of the assembled module must be $\\boldsymbol{30{\\mu}m}$ along the precision coordinate and $\\boldsymbol{80{\\mu}m}$ perpendicular to the chamber. All readout planes are segmented into strips with a pitch of $\\bold...

  4. Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

    Science.gov (United States)

    Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

    2016-01-01

    Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

  5. Pinpointing Needles in Giant Haystacks: Use of Text Mining to Reduce Impractical Screening Workload in Extremely Large Scoping Reviews

    Science.gov (United States)

    Shemilt, Ian; Simon, Antonia; Hollands, Gareth J.; Marteau, Theresa M.; Ogilvie, David; O'Mara-Eves, Alison; Kelly, Michael P.; Thomas, James

    2014-01-01

    In scoping reviews, boundaries of relevant evidence may be initially fuzzy, with refined conceptual understanding of interventions and their proposed mechanisms of action an intended output of the scoping process rather than its starting point. Electronic searches are therefore sensitive, often retrieving very large record sets that are…

  6. Pinpointing Needles in Giant Haystacks: Use of Text Mining to Reduce Impractical Screening Workload in Extremely Large Scoping Reviews

    Science.gov (United States)

    Shemilt, Ian; Simon, Antonia; Hollands, Gareth J.; Marteau, Theresa M.; Ogilvie, David; O'Mara-Eves, Alison; Kelly, Michael P.; Thomas, James

    2014-01-01

    In scoping reviews, boundaries of relevant evidence may be initially fuzzy, with refined conceptual understanding of interventions and their proposed mechanisms of action an intended output of the scoping process rather than its starting point. Electronic searches are therefore sensitive, often retrieving very large record sets that are…

  7. Large woody debris mobility and accumulation by an extreme flood - an example from the Dyje River, Czech Republic

    Science.gov (United States)

    Macka, Zdenek; Krejci, Lukas

    2010-05-01

    Large woody debris (LWD) in the form of logs, branches and their fragments play an important geomorphic and ecological role in forested watersheds. Especially when organized in accumulations and jams, LWD have been found to change hydraulic, morphological, sedimentary and biological characteristics of fluvial ecosystems. Our study focuses on LWD jams distribution and properties within the 44 km long forested reach of the Dyje River in south-eastern Czech Republic. The study reach is located between two large water reservoirs and the flow is regulated showing significant daily fluctuation of discharges due to water releases for power generation. River flows in the deeply incised meandering valley with the narrow and patchy floodplain. In 2002, and especially 2006 large volumes of LWD have been transported by river and the water reservoir downstream was congested with wood. Peak discharge of 2006 flood equalled 306 m3.s-1 which was estimated as 500 year flood. The flood caused significant mobility and redistribution of woody debris as in aquatic, so in riparian segment of the river corridor. The high rate of LWD transport is favoured by large bankfull channel width which exceeds the average tree height. LWD jams were defined as aggregations of three or more wood pieces with diameter ≥ 0.1 m and length ≥ 1 m. We surveyed LWD jams in 62 river reaches, which have been located at meander apexes, inflections and intermediate positions; the length of the reaches was 200 m. The overall number of registered LWD jams was 200. Majority of jams consist of solely allochthonous (transported) wood pieces (65 %), some jams are combination of large key trees and trapped transported pieces (29%), and only small proportion are jams formed by locally uprooted trees (12,6%). Number of wood pieces varies greatly from 3 to 98, the most common being the interval 5 - 10 pieces per jam. Spatial distribution of jams is longitudinally and transversally irregular within the river corridor

  8. Evaluation of different mechanical fruit harvesting systems and oil quality in very large size olive trees

    Directory of Open Access Journals (Sweden)

    Franco Famiani

    2014-11-01

    Full Text Available In 2006 and 2009, trials were carried out in the Apulia region in Southern Italy to evalu-ate the possibility of mechanizing olive harvesting in groves of old and very large trees. The trees belonged to the cultivars ‘Cellina di Nardò’ and ‘Ogliarola Salentina’. They were 60-100 years old and 7-9 m tall with a canopy volume of 140-360 m3. In the first half of November 2006, with a mechanical beater mounted on a tractor plus hand-held pneumatic combs, the harvesting yield was close to 90% of the total olives present in the canopy, and the harvesting working productivity was around 60 kg of harvested olives h-1 worker-1. With a self-propelled shaker attached to the main branches the harvesting yield was about 73% in ‘Cellina di Nardò’, and 40% in ‘Ogliarola Salentina’, while the harvesting working productivities were around 103 and 85 kg of harvested olives h-1 worker-1, respectively. In the second half of No-vember 2009, in ‘Cellina di Nardò’, with a mechanical beater mounted on a tractor plus nets on the ground or a catching frame (reversed umbrella mounted on another tractor, the harvesting yield was about 97%. The working productivity was about 98 kg of harvested olives h-1 worker-1 with the mechanical beater plus nets and around 133 kg of harvested olives h-1 worker-1 when the mechanical beater was combined with a reversed umbrella. The oil obtained from the mechanically harvested olives was always of high quality. A basic economic evaluation of the harvesting costs is also reported.

  9. Inferring Population Size History from Large Samples of Genome-Wide Molecular Data - An Approximate Bayesian Computation Approach.

    Directory of Open Access Journals (Sweden)

    Simon Boitard

    2016-03-01

    Full Text Available Inferring the ancestral dynamics of effective population size is a long-standing question in population genetics, which can now be tackled much more accurately thanks to the massive genomic data available in many species. Several promising methods that take advantage of whole-genome sequences have been recently developed in this context. However, they can only be applied to rather small samples, which limits their ability to estimate recent population size history. Besides, they can be very sensitive to sequencing or phasing errors. Here we introduce a new approximate Bayesian computation approach named PopSizeABC that allows estimating the evolution of the effective population size through time, using a large sample of complete genomes. This sample is summarized using the folded allele frequency spectrum and the average zygotic linkage disequilibrium at different bins of physical distance, two classes of statistics that are widely used in population genetics and can be easily computed from unphased and unpolarized SNP data. Our approach provides accurate estimations of past population sizes, from the very first generations before present back to the expected time to the most recent common ancestor of the sample, as shown by simulations under a wide range of demographic scenarios. When applied to samples of 15 or 25 complete genomes in four cattle breeds (Angus, Fleckvieh, Holstein and Jersey, PopSizeABC revealed a series of population declines, related to historical events such as domestication or modern breed creation. We further highlight that our approach is robust to sequencing errors, provided summary statistics are computed from SNPs with common alleles.

  10. Influence of local mechanical properties of high strength steel from large size forged ingot on ultrasonic wave velocities

    Science.gov (United States)

    Dupont-Marillia, Frederic; Jahazi, Mohamad; Lafreniere, Serge; Belanger, Pierre

    2017-02-01

    In the metallurgical industry, ultrasonic inspection is routinely used for the detection of defects. For the non-destructive inspection of small high strength steel parts, the material can be considered isotropic. However, when the size of the parts under inspection is large, the isotropic material hypothesis does not necessarily hold. The aim of this study is to investigate the effect of the variation in mechanical properties such as grain size, Young's modulus, Poissons ratio, chemical composition on longitudinal and transversal ultrasonic wave velocities. A 2 cm thick slice cut from a 40-ton bainitic steel ingot that was forged and heat treated was divided into 875 parallelepiped samples of 2x4x7 cm3. A metallurgical study has been performed to identify the phase and measure the grain size. Ultrasonic velocity measurements at 2.25 MHz for longitudinal and transversal waves were performed. The original location of the parallelepiped samples in the large forged ingot, and the measured velocities were used to produce an ultrasonic velocity map. Using a local isotropy assumption as well as the local density of the parallelepiped samples calculated from the chemical composition of the ingot provided by a previously published study, Youngs modulus and Poissons ratio were calculated from the longitudinal and transversal wave velocities. Micro-tensile test was used to validate Youngs modulus obtained by the ultrasonic wave velocity and an excellent agreement was observed.

  11. Feasibility of laparoscopic abdomino - perineal resection for large - sized anorectal cancers : A single - institution experience of 59 cases

    Directory of Open Access Journals (Sweden)

    Shukla Parul

    2009-03-01

    Full Text Available Background: Laparoscopic surgery for anorectal carcinoma is steadily gaining acceptance. While feasibility has already been reported, there are no reports addressing the impact of the actual size of large tumors on laparoscopic resectability . Aim: To assess the feasibility and short-term results (including oncological surrogate end points of performing laparoscopic abdomino-perineal resection (APR for large rectal cancers. Materials And Methods: Data of 59 patients undergoing laparoscopic APR (LAPR for anorectal malignancies were reviewed retrospectively. Outcomes were evaluated considering the surgical procedure, surface area of the tumor and short-term outcomes. Results: Of the 59 cases, LAPR could be completed in 53 (89.8% patients. Thirty-one (58.4% patients had Astler-Coller C2 stage disease. The mean surface area of the tumors was 24±17.5 (4-83 cm2. The number of median lymph nodes harvested per case was 12 (1-48. Circumferential resection margin (CRM was positive in 11 (20.7% patients. No mortality was reported. Conclusion: This appears to be the first report analyzing the impact of the size of the rectal tumor in LAPR. The data clearly indicates that LAPR is not hampered by the size of the tumor. There appears to be a need for preoperative radiotherapy and chemotherapy before undertaking surgery on larger tumors in view of the higher circumferential resection margin positivity.

  12. How extreme are extremes?

    Science.gov (United States)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  13. Efficient Algorithm for Locating and Sizing Series Compensation Devices in Large Transmission Grids: Model Implementation (PART 1)

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Vladimir [Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-14

    We explore optimization methods for planning the placement, sizing and operations of Flexible Alternating Current Transmission System (FACTS) devices installed to relieve transmission grid congestion. We limit our selection of FACTS devices to Series Compensation (SC) devices that can be represented by modification of the inductance of transmission lines. Our master optimization problem minimizes the l1 norm of the inductance modification subject to the usual line thermal-limit constraints. We develop heuristics that reduce this non-convex optimization to a succession of Linear Programs (LP) which are accelerated further using cutting plane methods. The algorithm solves an instance of the MatPower Polish Grid model (3299 lines and 2746 nodes) in 40 seconds per iteration on a standard laptop—a speed up that allows the sizing and placement of a family of SC devices to correct a large set of anticipated congestions. We observe that our algorithm finds feasible solutions that are always sparse, i.e., SC devices are placed on only a few lines. In a companion manuscript, we demonstrate our approach on realistically-sized networks that suffer congestion from a range of causes including generator retirement. In this manuscript, we focus on the development of our approach, investigate its structure on a small test system subject to congestion from uniform load growth, and demonstrate computational efficiency on a realistically-sized network.

  14. Tritium release behavior of Li4SiO4 pebbles with high densities and large grain sizes

    Science.gov (United States)

    Ran, Guangming; Xiao, Chengjian; Chen, Xiaojun; Gong, Yu; Zhao, Linjie; Wang, Heyi; Wang, Xiaolin

    2017-08-01

    Tritium release behavior from the Li4SiO4 pebbles with high densities (∼96%TD) and large grain sizes (100-300 μm) fabricated by a melt-based method (the M-OSi sample) was investigated through out-of-pile experiments. Another batch of Li4SiO4 pebbles with relatively low densities (∼86%TD) and small grain sizes (10-50 μm) fabricated by a wet method (the W-OSi sample) was used for comparative study. Comparing with the W-OSi sample, the temperature of tritium release from the M-OSi sample was found much higher. Moreover, the fraction of tritium gas released from the M-OSi sample was much larger, especially under helium purge gas. The big differences between the characteristics of tritium release from the two batches of samples can be explained reasonably by the effect of grain size, implying that the grain size played an important role in the tritium release behavior. This study can provide a guideline for optimizing the fabrication process of Li4SiO4 pebbles.

  15. The Physics of Protoplanetesimal Dust Agglomerates. Vi. Erosion of Large Aggregates and its Consequences for the Dust-Size Distribution

    CERN Document Server

    Schräpler, Rainer

    2011-01-01

    Observed protoplanetary disks consist of a large amount of micrometer-sized particles. Dullemond and Dominik (2005) pointed out for the first time the difficulty in explaining the strong mid-IR excess of classical T-Tauri stars without any dust-retention mechanisms. Because high relative velocities in between micrometer-sized and macroscopic particles exist in protoplanetary disks, we present experimental results on the erosion of macroscopic agglomerates consisting of micrometer-sized spherical particles via the impact of micrometer-sized particles. We find that after an initial phase, in which an impacting particle erodes up to 10 particles of an agglomerate, the impacting particles compress the agglomerate's surface, which partly passivates the agglomerates against erosion. Due to this effect the erosion halts within our error bars for impact velocities up to ~30 m/s. For larger velocities, the erosion is reduced by an order of magnitude. This outcome is explained and confirmed by a numerical model. In a n...

  16. Efficient algorithm for locating and sizing series compensation devices in large power transmission grids: I. Model implementation

    Science.gov (United States)

    Frolov, Vladimir; Backhaus, Scott; Chertkov, Misha

    2014-10-01

    We explore optimization methods for planning the placement, sizing and operations of flexible alternating current transmission system (FACTS) devices installed to relieve transmission grid congestion. We limit our selection of FACTS devices to series compensation (SC) devices that can be represented by modification of the inductance of transmission lines. Our master optimization problem minimizes the l1 norm of the inductance modification subject to the usual line thermal-limit constraints. We develop heuristics that reduce this non-convex optimization to a succession of linear programs (LP) that are accelerated further using cutting plane methods. The algorithm solves an instance of the MatPower Polish Grid model (3299 lines and 2746 nodes) in 40 seconds per iteration on a standard laptop—a speed that allows the sizing and placement of a family of SC devices to correct a large set of anticipated congestions. We observe that our algorithm finds feasible solutions that are always sparse, i.e., SC devices are placed on only a few lines. In a companion manuscript, we demonstrate our approach on realistically sized networks that suffer congestion from a range of causes, including generator retirement. In this manuscript, we focus on the development of our approach, investigate its structure on a small test system subject to congestion from uniform load growth, and demonstrate computational efficiency on a realistically sized network.

  17. Graphene-enhanced visible-light photocatalysis of large-sized CdS particles for wastewater treatment

    Science.gov (United States)

    Lü, Wei; Chen, Jie; Wu, Yao; Duan, Lianfeng; Yang, Yue; Ge, Xin

    2014-03-01

    The hybrid composites of graphene decorated by large-sized CdS particles (G/M-CdS) were prepared by a one-pot solvothermal route in which the reduction of graphite oxide into graphene was accompanied by the generation of microsized CdS particles. The structure and composition of the obtained nanocomposites were studied by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The CdS particles with the average sizes of approximately 640 nm were formed on graphene sheets. The as-prepared composite was used as adsorbent to remove dye from wastewater using the organic dye Rhodamine B as the adsorbate. The G/M-CdS composite reveals a high photodegradation rate under visible light irradiation. Our results demonstrate that the G/M-CdS is very promising for removing organic dyes from wastewater.

  18. Possibility of Underwater Explosive Welding for Making Large-Sized Thin Metal Plate Clad by Overlapping Plates

    Science.gov (United States)

    Hokamoto, Kazuyuki; Mori, Akihisa; Fujita, Masahiro

    The authors have developed a new method of explosive welding using underwater shock wave for the welding of thin plate on a substrate. Considering the size limitation of the welding area in using the technique, the possibility of overlapping thin plates to make large-sized welding area is investigated. In general, the results for the welding of Inconel 600 on 304 stainless steel show a macroscopically successful weld, but the microstructure shows some melting spots caused due to the trapping of metal jet during the welding process when the welding condition is changed. The welding process is discussed based on the experimental results in comparison with some numerically simulated results obtained by AUTODYN-2D code.

  19. Pressure-Induced Oriented Attachment Growth of Large-Size Crystals for Constructing 3D Ordered Superstructures.

    Science.gov (United States)

    Wang, Jun; Lian, Gang; Si, Haibin; Wang, Qilong; Cui, Deliang; Wong, Ching-Ping

    2016-01-26

    Oriented attachment (OA), a nonclassical crystal growth mechanism, provides a powerful bottom-up approach to obtain ordered superstructures, which also demonstrate exciting charge transmission characteristic. However, there is little work observably pronouncing the achievement of 3D OA growth of crystallites with large size (e.g., submicrometer crystals). Here, we report that SnO2 3D ordered superstructures can be synthesized by means of a self-limited assembly assisted by OA in a designed high-pressure solvothermal system. The size of primary building blocks is 200-250 nm, which is significantly larger than that in previous results (normally pressure plays the key role in the formation of 3D configuration and fusion of adjacent crystals. Furthermore, this high-pressure strategy can be readily expanded to additional materials. We anticipate that the welded structures will constitute an ideal system with relevance to applications in optical responses, lithium ion battery, solar cells, and chemical sensing.

  20. Effect of Temperature and Ram Speed on Isothermal Extrusion for Large-size Tube with Piece-wing

    Institute of Scientific and Technical Information of China (English)

    He YANG; Jun ZHANG; Yangmin HE; Bingtao HAN

    2005-01-01

    Heat energy change during the extrusion of 7075 aluminium alloy large-size tube with piece-wing in a container was analyzed. Extrusion load vs ram displacement diagrams and exit temperature vs ram displacement diagrams at various speeds were obtained by 3D FEM simulation. Results show that the exit temperature becomes higher as the ram speed and displacement increase. For large-size tube with piece-wing, there is certainly a curve of ram speed decreasing with increasing ram displacement, which enables isothermal extrusion to be achieved. Therefore,an attempt was made to divide the working stroke into five different zones. Each of them has a preset speed that decreases from the ram displacement beginning to the ending. And then, new exit temperature vs ram displacement diagram was obtained by 3D FEM simulation for the five different speeds. It is shown that the variation of exit temperature is very small. Through the above research, a basic method for realizing isothermal extrusion of 7075large-size tube with piece-wing was obtained, that is, the working stroke was divided into several different zones with a decreasing speed during extrusion, each zones' speed was real-time adjusted on the feedback signal of exit temperature by proportional hydraulic valve through closed-loop control. The engineering experiment verification was carried out on 100 MN aluminium extrusion press with oil-driven double action. The experimental results of the exit temperature agrees with the simulation ones. The achievements of this study may serve as a significant guide to the practice of the relevant processes, particularly for isothermal extrusion. The verified method has been used in the design and manufacture of 125 MN aluminium extrusion press with oil-driven double action.

  1. SWAP OBSERVATIONS OF THE LONG-TERM, LARGE-SCALE EVOLUTION OF THE EXTREME-ULTRAVIOLET SOLAR CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan [Royal Observatory of Belgium-SIDC, Avenue Circulaire 3, B-1180 Brussels (Belgium); Shearer, Paul [Department of Mathematics, 2074 East Hall, University of Michigan, 530 Church Street, Ann Arbor, MI 48109-1043 (United States)

    2013-11-01

    The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since 2010 February. With a field of view of 54 × 54 arcmin, SWAP provides the widest-field images of the EUV corona available from the perspective of the Earth. By carefully processing and combining multiple SWAP images, it is possible to produce low-noise composites that reveal the structure of the EUV corona to relatively large heights. A particularly important step in this processing was to remove instrumental stray light from the images by determining and deconvolving SWAP's point-spread function from the observations. In this paper, we use the resulting images to conduct the first-ever study of the evolution of the large-scale structure of the corona observed in the EUV over a three year period that includes the complete rise phase of solar cycle 24. Of particular note is the persistence over many solar rotations of bright, diffuse features composed of open magnetic fields that overlie polar crown filaments and extend to large heights above the solar surface. These features appear to be related to coronal fans, which have previously been observed in white-light coronagraph images and, at low heights, in the EUV. We also discuss the evolution of the corona at different heights above the solar surface and the evolution of the corona over the course of the solar cycle by hemisphere.

  2. Single-Seed Casting Large-Size Monocrystalline Silicon for High-Efficiency and Low-Cost Solar Cells

    Directory of Open Access Journals (Sweden)

    Bing Gao

    2015-09-01

    Full Text Available To grow high-quality and large-size monocrystal-line silicon at low cost, we proposed a single-seed casting technique. To realize this technique, two challenges—polycrystalline nucleation on the crucible wall and dislocation multiplication inside the crystal—needed to be addressed. Numerical analysis was used to develop solutions for these challenges. Based on an optimized furnace structure and operating conditions from numerical analysis, experiments were performed to grow monocrystalline silicon using the single-seed casting technique. The results revealed that this technique is highly superior to the popular high-performance multicrystalline and multiseed casting mono-like techniques.

  3. Single large or several small? The influence of prey size on feeding performance of Philodryas nattereri (Squamata: Serpentes

    Directory of Open Access Journals (Sweden)

    Sara Catunda Pereira

    2016-07-01

    Full Text Available This study aimed at evaluating the energetic return and feeding time on Philodryas nattereri kept in captivity. Snakes were fed biweekly for 60 days (four feeding trials, in two different feeding treatments (single and multiple prey items. The energetic return revealed no significant difference between the feeding treatments; however, we found a negative relationship between snake size and prey handling time during a feed using multiple prey items. In P. nattereri, when large preys are as easy to find as small ones, there seems to be no difference in energetic return.

  4. Technique challenges in coupling of high resolution spectrograph with extremely large telescope%高分辨率光谱仪与极大望远镜耦合问题分析

    Institute of Scientific and Technical Information of China (English)

    张弛; 朱永田; 张凯

    2014-01-01

    We reviewed the designing of several international ground-based extremely large opti-cal/infrared telescopes and introduced the problems faced in the coupling of high resolution spectrograph with telescopes of extremely large aperture .It is proposed that large area of ech-elle and ultrafast focal ratio camera can serve as a solution .According to the coupling rule of the spectrogragh and the telescope ,the diameter of collimated beam for a 30 m telescope would be over 70 cm ,and the size of the main dispersion echelle grating would be larger than 2 m2 . To build such huge and costly equipment would be difficult with current techniques .And large aperture camera with focal ratio F/0 .5 is also hard to design and manufacture .Image slicer , mosaic gratings and w hite pupil optic become major solutions in designing the high resolution spectrograph for an extremely large aperture telescope .%介绍国际上地面极大光学/红外望远镜的研制概况,分析高分辨率光谱仪与极大口径望远镜耦合中的难题,结果表明极大口径望远镜需要超大面积阶梯光栅和超快焦比相机。根据光谱仪与望远镜的匹配关系,30 m级极大口径望远镜的高分辨率光谱仪的准直光束将大于70 cm ,主色散阶梯光栅的面积大于2m2,照相机的焦比 F/0.5,按照目前的制造技术无法提供上述光栅和相机,因此,提出高分辨率光谱仪与极大望远镜进行耦合的技术。针对耦合问题给出了相应解决方案,即采用像切分器、拼接光栅以及白瞳设计等技术将是极大口径望远镜与高分辨率光谱仪耦合的主要解决方案。

  5. Large-size, high-uniformity, random silver nanowire networks as transparent electrodes for crystalline silicon wafer solar cells.

    Science.gov (United States)

    Xie, Shouyi; Ouyang, Zi; Jia, Baohua; Gu, Min

    2013-05-06

    Metal nanowire networks are emerging as next generation transparent electrodes for photovoltaic devices. We demonstrate the application of random silver nanowire networks as the top electrode on crystalline silicon wafer solar cells. The dependence of transmittance and sheet resistance on the surface coverage is measured. Superior optical and electrical properties are observed due to the large-size, highly-uniform nature of these networks. When applying the nanowire networks on the solar cells with an optimized two-step annealing process, we achieved as large as 19% enhancement on the energy conversion efficiency. The detailed analysis reveals that the enhancement is mainly caused by the improved electrical properties of the solar cells due to the silver nanowire networks. Our result reveals that this technology is a promising alternative transparent electrode technology for crystalline silicon wafer solar cells.

  6. Statistical Analysis of a Large Sample Size Pyroshock Test Data Set Including Post Flight Data Assessment. Revision 1

    Science.gov (United States)

    Hughes, William O.; McNelis, Anne M.

    2010-01-01

    The Earth Observing System (EOS) Terra spacecraft was launched on an Atlas IIAS launch vehicle on its mission to observe planet Earth in late 1999. Prior to launch, the new design of the spacecraft's pyroshock separation system was characterized by a series of 13 separation ground tests. The analysis methods used to evaluate this unusually large amount of shock data will be discussed in this paper, with particular emphasis on population distributions and finding statistically significant families of data, leading to an overall shock separation interface level. The wealth of ground test data also allowed a derivation of a Mission Assurance level for the flight. All of the flight shock measurements were below the EOS Terra Mission Assurance level thus contributing to the overall success of the EOS Terra mission. The effectiveness of the statistical methodology for characterizing the shock interface level and for developing a flight Mission Assurance level from a large sample size of shock data is demonstrated in this paper.

  7. An Ising iron(ii) chain exhibits a large finite-size energy barrier and "hard" magnetic behaviour.

    Science.gov (United States)

    Deng, Yi-Fei; Han, Tian; Xue, Wei; Hayashi, Naoaki; Kageyama, Hiroshi; Zheng, Yan-Zhen

    2017-01-31

    One-dimensional spin chains featuring strong axial anisotropic magnetism are promising candidates for isolatable and miniatured information storage materials, the so-called single-chain magnets (SCMs). Here we show a mixed azido/carboxylato bridged metamagnetic iron(ii) chain [Fe(N3)2(4-mpc)]n (4-mpc = N-methylpyridinium-4-carboxylate) with a large energy barrier of 150 K, a large remnant magnetization (1.55Nβ) and coercivity (1.7 T at 2 K) for homo-spin SCMs. Heat capacity and Mössbauer spectroscopy studies corroborate the intrinsic nature of SCM behavior regardless of weak interchain magnetic interactions, which lead to the coexistence of metamagnetism but not long-range magnetic ordering. Moreover, detailed magnetic investigations indicate that the system is not only within the "Ising limit" but also in the "finite-size" regime.

  8. Exact solution of the thermodynamics and size parameters of a polymer confined to a lattice of finite size: Large chain limit

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Chad R., E-mail: chad.snyder@nist.gov; Guttman, Charles M., E-mail: charles.guttman@nist.gov [Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899 (United States); Di Marzio, Edmund A., E-mail: edmund.dimarzio@nist.gov [Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899 (United States); Bio-Poly-Phase, 14205 Parkvale Road, Rockville, Maryland 20853 (United States)

    2014-01-21

    We extend the exact solutions of the Di Marzio-Rubin matrix method for the thermodynamic properties, including chain density, of a linear polymer molecule confined to walk on a lattice of finite size. Our extensions enable (a) the use of higher dimensions (explicit 2D and 3D lattices), (b) lattice boundaries of arbitrary shape, and (c) the flexibility to allow each monomer to have its own energy of attraction for each lattice site. In the case of the large chain limit, we demonstrate how periodic boundary conditions can also be employed to reduce computation time. Advantages to this method include easy definition of chemical and physical structure (or surface roughness) of the lattice and site-specific monomer-specific energetics, and straightforward relatively fast computations. We show the usefulness and ease of implementation of this extension by examining the effect of energy variation along the lattice walls of an infinite rectangular cylinder with the idea of studying the changes in properties caused by chemical inhomogeneities on the surface of the box. Herein, we look particularly at the polymer density profile as a function of temperature in the confined region for very long polymers. One particularly striking result is the shift in the critical condition for adsorption due to surface energy inhomogeneities and the length scale of the inhomogeneities; an observation that could have important implications for polymer chromatography. Our method should have applications to both copolymers and biopolymers of arbitrary molar mass.

  9. International Airport Impacts to Air Quality: Size and Related Properties of Large Increases in Ultrafine Particle Number Concentrations.

    Science.gov (United States)

    Hudda, N; Fruin, S A

    2016-04-05

    We measured particle size distributions and spatial patterns of particle number (PN) and particle surface area concentrations downwind from the Los Angeles International Airport (LAX) where large increases (over local background) in PN concentrations routinely extended 18 km downwind. These elevations were mostly comprised of ultrafine particles smaller than 40 nm. For a given downwind distance, the greatest increases in PN concentrations, along with the smallest mean sizes, were detected at locations under the landing jet trajectories. The smaller size of particles in the impacted area, as compared to the ambient urban aerosol, increased calculated lung deposition fractions to 0.7-0.8 from 0.5-0.7. A diffusion charging instrument (DiSCMini), that simulates alveolar lung deposition, measured a fivefold increase in alveolar-lung deposited surface area concentrations 2-3 km downwind from the airport (over local background), decreasing steadily to a twofold increase 18 km downwind. These ratios (elevated lung-deposited surface area over background) were lower than the corresponding ratios for elevated PN concentrations, which decreased from tenfold to twofold over the same distance, but the spatial patterns of elevated concentrations were similar. It appears that PN concentration can serve as a nonlinear proxy for lung deposited surface area downwind of major airports.

  10. Drug testing and flow cytometry analysis on a large number of uniform sized tumor spheroids using a microfluidic device

    Science.gov (United States)

    Patra, Bishnubrata; Peng, Chien-Chung; Liao, Wei-Hao; Lee, Chau-Hwang; Tung, Yi-Chung

    2016-02-01

    Three-dimensional (3D) tumor spheroid possesses great potential as an in vitro model to improve predictive capacity for pre-clinical drug testing. In this paper, we combine advantages of flow cytometry and microfluidics to perform drug testing and analysis on a large number (5000) of uniform sized tumor spheroids. The spheroids are formed, cultured, and treated with drugs inside a microfluidic device. The spheroids can then be harvested from the device without tedious operation. Due to the ample cell numbers, the spheroids can be dissociated into single cells for flow cytometry analysis. Flow cytometry provides statistical information in single cell resolution that makes it feasible to better investigate drug functions on the cells in more in vivo-like 3D formation. In the experiments, human hepatocellular carcinoma cells (HepG2) are exploited to form tumor spheroids within the microfluidic device, and three anti-cancer drugs: Cisplatin, Resveratrol, and Tirapazamine (TPZ), and their combinations are tested on the tumor spheroids with two different sizes. The experimental results suggest the cell culture format (2D monolayer vs. 3D spheroid) and spheroid size play critical roles in drug responses, and also demonstrate the advantages of bridging the two techniques in pharmaceutical drug screening applications.

  11. Thermal characterization of large size lithium-ion pouch cell based on 1d electro-thermal model

    Science.gov (United States)

    Vertiz, G.; Oyarbide, M.; Macicior, H.; Miguel, O.; Cantero, I.; Fernandez de Arroiabe, P.; Ulacia, I.

    2014-12-01

    Thermal management is one of the key factors to keep lithium-ion cells in optimum electrical performance, under safe working conditions and into a reasonably low ageing process. This issue is becoming particularly relevant due to the heterogeneous heat generation along the cell. Cell working temperature is determined by ambient temperature, heat generation and evacuation capacity. Therefore, thermal management is established by: i) the intrinsic thermal properties (heat capacity & thermal conductivity) and ii) the heat generation electro-thermal parameters (internal resistance, open circuit voltage & entropic factor). In this research, different methods - calculated and experimental - are used to characterize the main heat properties of a 14Ah -LiFePO4/graphite-commercial large sizes pouch cell. In order to evaluate the accuracy of methods, two comparisons were performed. First, Newman heat generation estimations were compared with experimental heat measurements. Secondly, empirical thermal cell behaviour was match with 1D electro-thermal model response. Finally, considering the results, the most adequate methodology to evaluate the key thermal parameters of a large size Lithium-ion pouch cell are proposed to be: i) pulse method for internal resistance, ii)heat loss method for entropic factor; and iii)experimental measurement (ARC calorimeter and C-177-97 standard method) for heat capacity and thermal conductivity.

  12. Electrochemical properties of large-sized pouch-type lithium ion batteries with bio-inspired organic cathode materials

    Science.gov (United States)

    Yeo, Jae-Seong; Yoo, Eun-Ji; Ha, Sang-Hyeon; Cheong, Dong-Ik; Cho, Sung-Baek

    2016-05-01

    To investigate the feasibility of scaling up bio-inspired organic materials as cathode materials in lithium ion batteries, large-sized pouch cells are successfully prepared via tape casting using lumichrome with an alloxazine structure and aqueous styrene butadiene rubber-carboxymethyl cellulose (SBR-CMC) binders. A battery module with a two-in-series, six-in-parallel (2S6P) configuration is also successfully fabricated and is able to power blue LEDs (850 mW). Lumichrome shows no structural changes during the fabrication processes used to produce the positive electrode. The large-sized pouch cells show two sets of cathodic and anodic peaks with average potentials of 2.58 V and 2.26 V vs. Li/Li+, respectively. The initial discharge capacities are 142 mAh g-1 and 148 mAh g-1 for ethylene carbonate-dimethyl carbonate (EC-DMC) and tetraethylene glycol dimethyl ether (TEGDME) electrolytes, respectively, similar to that of a coin cell (149 mAh g-1). The EC-DMC-injected pouch cells exhibit higher rate performance and cyclability than the TEGDME-injected ones. The TEGDME electrolyte is not suitable for lithium metal anodes because of electrolyte decomposition and subsequent cell swelling.

  13. Large Size Color-tunable Electroluminescence from Cationic Iridium Complexes-based Light-emitting Electrochemical Cells

    Science.gov (United States)

    Zeng, Qunying; Li, Fushan; Guo, Tailiang; Shan, Guogang; Su, Zhongmin

    2016-06-01

    Solution-processable light-emitting electrochemical cells (LECs) with simple device architecture have become an attractive candidate for application in next generation lighting and flat-panel displays. Herein, single layer LECs employing two cationic Ir(III) complexes showing highly efficient blue-green and yellow electroluminescence with peak current efficiency of 31.6 cd A‑1 and 40.6 cd A‑1, respectively, have been reported. By using both complexes in the device, color-tunable LECs with a single spectral peak in the wavelength range from 499 to 570 nm were obtained by varying their rations. In addition, the fabrication of efficient LECs was demonstrated based on low cost doctor-blade coating technique, which was compatible with the roll to roll fabrication process for the large size production. In this work, for the first time, 4 inch LEC devices by doctor-blade coating were fabricated, which exhibit the efficiencies of 23.4 cd A‑1 and 25.4 cd A‑1 for the blue-green and yellow emission, respectively. The exciting results indicated that highly efficient LECs with controllable color could be realized and find practical application in large size lighting and displays.

  14. Sexual-size dimorphism modulates the trade-off between exploiting food and wind resources in a large avian scavenger.

    Science.gov (United States)

    Alarcón, Pablo A E; Morales, Juan M; Donázar, José A; Sánchez-Zapata, José A; Hiraldo, Fernando; Lambertucci, Sergio A

    2017-09-13

    Animals are expected to synchronize activity routines with the temporal patterns at which resources appear in nature. Accordingly, species that depend on resources showing temporally mismatched patterns should be expected to schedule routines that balance the chances of exploiting each of them. Large avian scavengers depend on carcasses which are more likely available early in the morning, but they also depend on wind resources (i.e. uplifts) to subside flight which are stronger in afternoon hours. To understand how these birds deal with this potential trade-off, we studied the daily routines of GPS-tagged individuals of the world's largest terrestrial soaring scavenger, the Andean condor (Vultur gryphus). Andean condors vary largely in weight and show a huge sexual dimorphism that allowed us to evaluate the effect of sex and body size on their daily routines. We found that condors use an intermediate solution strategy between the best times to exploit carcasses and uplifts, with this strategy changing over the year. Bigger males scheduled earlier routines that aligned more closely with uplift availability compared to smaller females, resulting in a partial temporal segregation between sexes. Condors' routines reflect a sexual-size dependent trade-off that may underpin ecological and sociobiological traits of the studied population.

  15. Deformation and Recrystallization Behavior of the Cast Structure in Large Size, High Strength Steel Ingots: Experimentation and Modeling

    Science.gov (United States)

    Chadha, K.; Shahriari, D.; Tremblay, R.; Bhattacharjee, P. P.; Jahazi, M.

    2017-07-01

    Constitutive modeling of the ingot breakdown process of large size ingots of high strength steel was carried out through comprehensive thermomechanical processing using Gleeble 3800® thermomechanical simulator, finite element modeling (FEM), optical and electron back scatter diffraction (EBSD). For this purpose, hot compression tests in the range of 1473 K to 1323 K (1200 °C to 1050 °C) and strain rates of 0.25 to 2 s-1 were carried out. The stress-strain curves describing the deformation behavior of the dendritic microstructure of the cast ingot were analyzed in terms of the Arrhenius and Hansel-Spittel models which were implemented in Forge NxT 1.0® FEM software. The results indicated that the Arrhenius model was more reliable in predicting microstructure evolution of the as-cast structure during ingot breakdown, particularly the occurrence of dynamic recrystallization (DRX) process which was a vital parameter in estimating the optimum loads for forming of large size components. The accuracy and reliability of both models were compared in terms of correlation coefficient (R) and the average absolute relative error (ARRE).

  16. Deformation and Recrystallization Behavior of the Cast Structure in Large Size, High Strength Steel Ingots: Experimentation and Modeling

    Science.gov (United States)

    Chadha, K.; Shahriari, D.; Tremblay, R.; Bhattacharjee, P. P.; Jahazi, M.

    2017-09-01

    Constitutive modeling of the ingot breakdown process of large size ingots of high strength steel was carried out through comprehensive thermomechanical processing using Gleeble 3800® thermomechanical simulator, finite element modeling (FEM), optical and electron back scatter diffraction (EBSD). For this purpose, hot compression tests in the range of 1473 K to 1323 K (1200 °C to 1050 °C) and strain rates of 0.25 to 2 s-1 were carried out. The stress-strain curves describing the deformation behavior of the dendritic microstructure of the cast ingot were analyzed in terms of the Arrhenius and Hansel-Spittel models which were implemented in Forge NxT 1.0® FEM software. The results indicated that the Arrhenius model was more reliable in predicting microstructure evolution of the as-cast structure during ingot breakdown, particularly the occurrence of dynamic recrystallization (DRX) process which was a vital parameter in estimating the optimum loads for forming of large size components. The accuracy and reliability of both models were compared in terms of correlation coefficient (R) and the average absolute relative error (ARRE).

  17. Red blood cell size is inversely associated with leukocyte telomere length in a large multi-ethnic population.

    Directory of Open Access Journals (Sweden)

    Julia Kozlitina

    Full Text Available Although mutations in the genes encoding either the protein or RNA component of telomerase have been found in patients with various blood disorders, the impact of telomere length on hematopoiesis is less well understood for subjects from the general population. Here we have measured telomere lengths of genomic DNA isolated from circulating leukocytes of 3157 subjects, ranging from 18 to 85 years of age, enrolled in a large multiethnic population based study, the Dallas Heart Study 2. Shorter telomere lengths are marginally associated with lower red blood cell counts in this cohort, but are significantly associated with larger mean red blood cell size (as measured by the MCV, increased red blood cell distribution width (RDW, higher hemoglobin levels and lower platelet counts, even after correction for age, gender and ethnicity (p-values of 50 years vs. p = 0.0006 for <50 years of age. To our knowledge, this is the first report of an association between telomere length and red cell size in a large urban US population and suggests a biologic mechanism for macrocytosis of aging.

  18. An Examination of Teachers' Perceptions and Practice when Teaching Large and Reduced-Size Classes: Do Teachers Really Teach Them in the Same Way?

    Science.gov (United States)

    Harfitt, Gary James

    2012-01-01

    Class size research suggests that teachers do not vary their teaching strategies when moving from large to smaller classes. This study draws on interviews and classroom observations of three experienced English language teachers working with large and reduced-size classes in Hong Kong secondary schools. Findings from the study point to subtle…

  19. An extreme breaching of a barrier spit: insights on large breach formation and its impact on barrier dynamics

    Science.gov (United States)

    Iulian Zăinescu, Florin; Vespremeanu-Stroe, Alfred; Tătui, Florin

    2017-04-01

    In this study, we document a case of exceptionally large natural breaching of a sandy spit (Sacalin barrier, Danube delta) using Lidar data and satellite imagery, annual (and seasonal) surveys of topography and bathymetry on successive cross-barrier profiles, and hourly datasets of wind and waves. The breach morphology and dynamics was monitored and described from its inception to closure, together with its impact on the adjoining features (upper shoreface, back-barrier lagoon, downdrift coast) and on the local sediment budgets. Breaching is first observed to occur on a beach-length of 0.5 km in April 2012 and two years later reached 3.5 km (May 2014). The barrier translates to a recovery stage dominated by continuous back-barrier deposition through subaqueous cross-breach sediment transport. Soon, the barrier widening triggers a negative feedback which limits the back-barrier sediment transfer. As a result, back-barrier deposition decreases whilst the barrier aggradation through overwash becomes more frequent. The event was found to be a natural experiment which switched the barrier's decadal evolution from low cross-shore transport to high cross-shore transport over the barrier. Although previously considered as constant, the cross-shore transport recorded during the large breach lifespan is an order of magnitude larger than in the non-breach period. 3 x 106 m3 of sediment were deposited in three years which is equivalent to the modelled longshore transport in the region. Nevertheless, the sediment circuits are more complex involving exchanges with the upper shoreface, as indicated by the extensive erosion down to -4m. In the absence of tides, the Sacalin breach closed naturally in 3 years and brings a valuable contribution on how breaches may evolve, as only limited data has been internationally reported until now. The very high deposition rate of sediment in the breach is a testimony of the high sediment volumes supplied by the longshore transport and the high

  20. pH-activated size reduction of large compound nanoparticles for in vivo nucleus-targeted drug delivery.

    Science.gov (United States)

    Fan, Yanbin; Li, Chunyan; Li, Fuyou; Chen, Daoyong

    2016-04-01

    Nucleus-targeted drug delivery is a promising strategy for anticancer therapy, but in vivo nucleus-targeted drug delivery has been challenging. Limited by the channel size of the nucleopore, vehicles that enter the nucleus via the nucleopore actively should be small and decorated with nuclear localization signal (NLS). However, the small vehicle size may promote leakage of vehicles into normal tissues, and the positively-charged NLS can lead to strong non-specific interactions in vivo. In the present study, we demonstrate an in vivo nucleus-targeted drug delivery using large compound nanoparticles with detachable PEG shell. The nanoparticles are composed of PEG-benzoic imine-oligo-l-lysine/iridium(III) metallodrug complex and formed in a kinetically-controlled fashion. Under physiological conditions (pH 7.4), the nanoparticles are large (ca. 150 nm) and protected by an inert PEG shell. When internalized into intracellular acidic endo/lysosomes of cancer cells, the nanoparticles dissociate into smaller ones (ca. 40 nm) and the PEG chains detach due to the cleavage of the benzoic imine bond at low pH. The small nanoparticles, with exposure of the oligo-l-lysine after the detachment of the PEG shield, then translocate into the nucleus via the nucleopore due to the small size and nuclear localization ability of the oligo-l-lysine. Importantly, the small particles could significantly release the contained drug into the nucleus, leading to ca. 20-fold higher cytotoxicity compared to the native drug in vitro. Further in vivo application of the nucleus-targeting nano-system in a nude-mice model showed significant tumor inhibition and remarkable life-span elongation.

  1. Measurements of {sup 222}Rn and{sup 220}Rn with a large size collector of radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qifan; Cheng, Jianping; Liu, Guilin; Zhu, Li [Tsinghua Univ., Beijing (China); Ja, Wenyi; Fang, Fang [Chengdu Univ. of Technology, Chengdu (China)

    2002-07-01

    People have paid more attention to radon since 1980s. Radon concentrations in high background radiation areas in the south are higher than others in China, especially {sup 220} Rn concentration is significantly high. Therefore, measurement of {sup 222} Rn and {sup 220} Rn concentration should be carried out there. I will introduce a large size collector of radon progeny and its applications in this paper. The collector is a sheet of polyvinyl chloride fibre with electrostatics of -500V {approx} -700V. Its size (60mm in diameter) is larger than others (26mm in diameter) that work as the same principle. The collector is more effective to adsorb radon progeny than most of others. The equipment of ZnS(Ag) Scintillation Counting System is available for large size collectors to detect radon progeny. Therefore its sensitivity of measurement is high than others. According to the different half life of radon progeny and based on both theory and experiment, a formula for discrimination and calculation of {sup 222} Rn and {sup 220} Rn concentrations was deduced. The {sup 222} Rn and {sup 220} Rn concentrations were surveyed with electrostatic collectors of radon progeny on the campus of commercial school and some other areas in Hainan, southern China. Neither {sup 222} Rn nor {sup 220} Rn concentrations were found significant high. However several faults underground were delineated. The collector is also used to study radon transportation. Results indicate that radon changes regularly with date when it has transported for a certain distance. Velocities of radon migration in the four media are quite different. Radon migrates more quickly in vertical tube than in the horizontal tube.

  2. Amorphous InGaMgO Ultraviolet Photo-TFT with Ultrahigh Photosensitivity and Extremely Large Responsivity

    Directory of Open Access Journals (Sweden)

    Yiyu Zhang

    2017-02-01

    Full Text Available Recently, amorphous InGaZnO ultraviolet photo thin-film transistors have exhibited great potential for application in future display technologies. Nevertheless, the transmittance of amorphous InGaZnO (~80% is still not high enough, resulting in the relatively large sacrifice of aperture ratio for each sensor pixel. In this work, the ultraviolet photo thin-film transistor based on amorphous InGaMgO, which processes a larger bandgap and higher transmission compared to amorphous InGaZnO, was proposed and investigated. Furthermore, the effects of post-deposition annealing in oxygen on both the material and ultraviolet detection characteristics of amorphous InGaMgO were also comprehensively studied. It was found that oxygen post-deposition annealing can effectively reduce oxygen vacancies, leading to an optimized device performance, including lower dark current, higher sensitivity, and larger responsivity. We attributed it to the combined effect of the reduction in donor states and recombination centers, both of which are related to oxygen vacancies. As a result, the 240-min annealed device exhibited the lowest dark current of 1.7 × 10−10 A, the highest photosensitivity of 3.9 × 106, and the largest responsivity of 1.5 × 104 A/W. Therefore, our findings have revealed that amorphous InGaMgO photo thin-film transistors are a very promising alternative for UV detection, especially for application in touch-free interactive displays.

  3. From mantle to critical zone: A review of large and giant sized deposits of the rare earth elements

    Directory of Open Access Journals (Sweden)

    M.P. Smith

    2016-05-01

    Full Text Available The rare earth elements are unusual when defining giant-sized ore deposits, as resources are often quoted as total rare earth oxide, but the importance of a deposit may be related to the grade for individual, or a limited group of the elements. Taking the total REE resource, only one currently known deposit (Bayan Obo would class as giant (>1.7 × 107 tonnes contained metal, but a range of others classify as large (>1.7 × 106 tonnes. With the exception of unclassified resource estimates from the Olympic Dam IOCG deposit, all of these deposits are related to alkaline igneous activity – either carbonatites or agpaitic nepheline syenites. The total resource in these deposits must relate to the scale of the primary igneous source, but the grade is a complex function of igneous source, magmatic crystallisation, hydrothermal modification and supergene enrichment during weathering. Isotopic data suggest that the sources conducive to the formation of large REE deposits are developed in subcontinental lithospheric mantle, enriched in trace elements either by plume activity, or by previous subduction. The reactivation of such enriched mantle domains in relatively restricted geographical areas may have played a role in the formation of some of the largest deposits (e.g. Bayan Obo. Hydrothermal activity involving fluids from magmatic to meteoric sources may result in the redistribution of the REE and increases in grade, depending on primary mineralogy and the availability of ligands. Weathering and supergene enrichment of carbonatite has played a role in the formation of the highest grade deposits at Mount Weld (Australia and Tomtor (Russia. For the individual REE with the current highest economic value (Nd and the HREE, the boundaries for the large and giant size classes are two orders of magnitude lower, and deposits enriched in these metals (agpaitic systems, ion absorption deposits may have significant economic impact in the near future.

  4. From mantle to critical zone:A review of large and giant sized deposits of the rare earth elements

    Institute of Scientific and Technical Information of China (English)

    M.P. Smith; K. Moore; D. Kavecsánszki; A.A. Finch; J. Kynicky; F. Wall

    2016-01-01

    The rare earth elements are unusual when defining giant-sized ore deposits, as resources are often quoted as total rare earth oxide, but the importance of a deposit may be related to the grade for indi-vidual, or a limited group of the elements. Taking the total REE resource, only one currently known deposit (Bayan Obo) would class as giant (>1.7 ? 107 tonnes contained metal), but a range of others classify as large (>1.7 ? 106 tonnes). With the exception of unclassified resource estimates from the Olympic Dam IOCG deposit, all of these deposits are related to alkaline igneous activity e either car-bonatites or agpaitic nepheline syenites. The total resource in these deposits must relate to the scale of the primary igneous source, but the grade is a complex function of igneous source, magmatic crystal-lisation, hydrothermal modification and supergene enrichment during weathering. Isotopic data suggest that the sources conducive to the formation of large REE deposits are developed in subcontinental lithospheric mantle, enriched in trace elements either by plume activity, or by previous subduction. The reactivation of such enriched mantle domains in relatively restricted geographical areas may have played a role in the formation of some of the largest deposits (e.g. Bayan Obo). Hydrothermal activity involving fluids from magmatic to meteoric sources may result in the redistribution of the REE and increases in grade, depending on primary mineralogy and the availability of ligands. Weathering and supergene enrichment of carbonatite has played a role in the formation of the highest grade deposits at Mount Weld (Australia) and Tomtor (Russia). For the individual REE with the current highest economic value (Nd and the HREE), the boundaries for the large and giant size classes are two orders of magnitude lower, and deposits enriched in these metals (agpaitic systems, ion absorption deposits) may have significant economic impact in the near future.

  5. Large population sizes mitigate negative effects of variable weather conditions on fruit set in two spring woodland orchids.

    Science.gov (United States)

    Jacquemyn, Hans; Brys, Rein; Honnay, Olivier

    2009-08-23

    Global circulation models predict increased climatic variability, which could increase variability in demographic rates and affect long-term population viability. In animal-pollinated species, pollination services, and thus fruit and seed set, may be highly variable among years and sites, and depend on both local environmental conditions and climatic variables. Orchid species may be particularly vulnerable to disruption of their pollination services, as most species depend on pollinators for successful fruit set and because seed germination and seedling recruitment are to some extent dependent on the amount of fruits and seeds produced. Better insights into the factors determining fruit and seed set are therefore indispensable for a better understanding of population dynamics and viability of orchid populations under changing climatic conditions. However, very few studies have investigated spatio-temporal variation in fruit set in orchids. Here, we quantified fruit production in eight populations of the orchid Orchis purpurea that does not reward pollinators and 13 populations of the rewarding Neottia (Listera) ovata during five consecutive years (2002-2006). Fruit production in large populations showed much higher stability than that in small populations and was less affected by extreme weather conditions. Our results highlight the potential vulnerability of small orchid populations to an increasingly variable climate through highly unpredictable fruit-set patterns.

  6. Cloning and Heterologous Expression of a Large-sized Natural Product Biosynthetic Gene Cluster in Streptomyces Species

    Science.gov (United States)

    Nah, Hee-Ju; Pyeon, Hye-Rim; Kang, Seung-Hoon; Choi, Si-Sun; Kim, Eung-Soo

    2017-01-01

    Actinomycetes family including Streptomyces species have been a major source for the discovery of novel natural products (NPs) in the last several decades thanks to their structural novelty, diversity and complexity. Moreover, recent genome mining approach has provided an attractive tool to screen potentially valuable NP biosynthetic gene clusters (BGCs) present in the actinomycetes genomes. Since many of these NP BGCs are silent or cryptic in the original actinomycetes, various techniques have been employed to activate these NP BGCs. Heterologous expression of BGCs has become a useful strategy to produce, reactivate, improve, and modify the pathways of NPs present at minute quantities in the original actinomycetes isolates. However, cloning and efficient overexpression of an entire NP BGC, often as large as over 100 kb, remain challenging due to the ineffectiveness of current genetic systems in manipulating large NP BGCs. This mini review describes examples of actinomycetes NP production through BGC heterologous expression systems as well as recent strategies specialized for the large-sized NP BGCs in Streptomyces heterologous hosts. PMID:28360891

  7. Spitzer SAGE-Spec: Near Infrared Spectroscopy, Dust Shells, and Cool Envelopes in Extreme Large Magellanic Cloud Asymptotic Giant Branch Stars

    Science.gov (United States)

    Blum, R. D.; Srinivasan, S.; Kemper, F.; Ling, B.; Volk, K.

    2014-11-01

    K-band spectra are presented for a sample of 39 Spitzer Infrared Spectrograph (IRS) SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near-infrared—Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near-infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars was chosen from the luminous and red extreme ``tip" of the color-magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich ``stellar" cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near-infrared and mid-infrared colors. One object in our sample, HV 915, a known post-asymptotic giant branch star of the RV Tau type, exhibits CO 2.3 μm band head emission consistent with previous work that demonstrates that the object has a circumstellar disk. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  8. Spitzer SAGE-Spec: Near infrared spectroscopy, dust shells, and cool envelopes in extreme Large Magellanic Cloud asymptotic giant branch stars

    Energy Technology Data Exchange (ETDEWEB)

    Blum, R. D. [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Srinivasan, S.; Kemper, F.; Ling, B. [Academia Sinica, Institute of Astronomy and Astrophysics, 11F of Astronomy-Mathematics Building, NTU/AS, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Volk, K. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-11-01

    K-band spectra are presented for a sample of 39 Spitzer Infrared Spectrograph (IRS) SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near-infrared—Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near-infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars was chosen from the luminous and red extreme ''tip'' of the color-magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich ''stellar'' cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near-infrared and mid-infrared colors. One object in our sample, HV 915, a known post-asymptotic giant branch star of the RV Tau type, exhibits CO 2.3 μm band head emission consistent with previous work that demonstrates that the object has a circumstellar disk.

  9. Ultrasensitive nonlinear absorption response of large-size topological insulator and application in low-threshold bulk pulsed lasers.

    Science.gov (United States)

    Xu, Jin-Long; Sun, Yi-Jian; He, Jing-Liang; Wang, Yan; Zhu, Zhao-Jie; You, Zhen-Yu; Li, Jian-Fu; Chou, Mitch M C; Lee, Chao-Kuei; Tu, Chao-Yang

    2015-10-07

    Dirac-like topological insulators have attracted strong interest in optoelectronic application because of their unusual and startling properties. Here we report for the first time that the pure topological insulator Bi2Te3 exhibited a naturally ultrasensitive nonlinear absorption response to photoexcitation. The Bi2Te3 sheets with lateral size up to a few micrometers showed extremely low saturation absorption intensities of only 1.1 W/cm(2) at 1.0 and 1.3 μm, respectively. Benefiting from this sensitive response, a Q-switching pulsed laser was achieved in a 1.0 μm Nd:YVO4 laser where the threshold absorbed pump power was only 31 mW. This is the lowest threshold in Q-switched solid-state bulk lasers to the best of our knowledge. A pulse duration of 97 ns was observed with an average power of 26.1 mW. A Q-switched laser at 1.3 μm was also realized with a pulse duration as short as 93 ns. Moreover, the mode locking operation was demonstrated. These results strongly exhibit that Bi2Te3 is a promising optical device for constructing broadband, miniature and integrated high-energy pulsed laser systems with low power consumption. Our work clearly points out a significantly potential avenue for the development of two-dimensional-material-based broadband ultrasensitive photodetector and other optoelectronic devices.

  10. Identification of the non-stationarity of extreme precipitation events and correlations with large-scale ocean-atmospheric circulation patterns: A case study in the Wei River Basin, China

    Science.gov (United States)

    Liu, Saiyan; Huang, Shengzhi; Huang, Qiang; Xie, Yangyang; Leng, Guoyong; Luan, Jinkai; Song, Xiaoyu; Wei, Xiu; Li, Xiangyang

    2017-05-01

    The investigation of extreme precipitation events in terms of variation characteristics, stationarity, and their underlying causes is of great significance to better understand the regional response of the precipitation variability to global climate change. In this study, the Wei River Basin (WRB), a typical eco-environmentally vulnerable region of the Loess Plateau in China was selected as the study region. A set of precipitation indices was adopted to study the changing patterns of precipitation extremes and the stationarity of extreme precipitation events. Furthermore, the correlations between the Pacific Decadal Oscillation (PDO)/El Niño-Southern Oscillation (ENSO) events and precipitation extremes were explored using the cross wavelet technique. The results indicate that: (1) extreme precipitation events in the WRB are characterized by a significant decrease of consecutive wet days (CWD) at the 95% confidence level; (2) compared with annual precipitation, daily precipitation extremes are much more sensitive to changing environments, and the assumption of stationarity of extreme precipitation in the WRB is invalid, especially in the upstream, thereby introducing large uncertainty to the design and management of water conservancy engineering; (3) both PDO and ENSO events have a strong influence on precipitation extremes in the WRB. These findings highlight the importance of examining the validity of the stationarity assumption in extreme hydrological frequency analysis, which has great implications for the prediction of extreme hydrological events.

  11. Real-time turbulence profiling with a pair of laser guide star Shack-Hartmann wavefront sensors for wide-field adaptive optics systems on large to extremely large telescopes.

    Science.gov (United States)

    Gilles, L; Ellerbroek, B L

    2010-11-01

    Real-time turbulence profiling is necessary to tune tomographic wavefront reconstruction algorithms for wide-field adaptive optics (AO) systems on large to extremely large telescopes, and to perform a variety of image post-processing tasks involving point-spread function reconstruction. This paper describes a computationally efficient and accurate numerical technique inspired by the slope detection and ranging (SLODAR) method to perform this task in real time from properly selected Shack-Hartmann wavefront sensor measurements accumulated over a few hundred frames from a pair of laser guide stars, thus eliminating the need for an additional instrument. The algorithm is introduced, followed by a theoretical influence function analysis illustrating its impulse response to high-resolution turbulence profiles. Finally, its performance is assessed in the context of the Thirty Meter Telescope multi-conjugate adaptive optics system via end-to-end wave optics Monte Carlo simulations.

  12. Design of Quenching Process for Large-sized AISI P20 Steel Block Used as Plastic Die

    Institute of Scientific and Technical Information of China (English)

    Dongli SONG; Jianfeng GU; Jiansheng PAN; Xin YAO

    2006-01-01

    For large-sized AISI P20 steel block used as plastic die with a thickness of more than 200 mm, appropriate quenching processes are the key to obtain much thick hardened layer. In this paper, different quenching processes of AISI P20 steel block such as oil quenching, direct water quenching, water quenching with precooling and water quenching with pre-cooling and self-tempering were numerically investigated by computer simulation based on the detailed discussion on the mathematical models of quenching processes including partial differential equations of heat transfer, thermal physical properties, latent heat, heat transfer coefficient and calculation of phase transformation, The results show that the water quenching with pre-cooling and self-tempering process can not only effectively avoid quenching cracks, but also obtain deeper harden depth than oil quenching.

  13. Reliability design of mono-leaf spring for front-axle suspension of large-sized trucks

    Energy Technology Data Exchange (ETDEWEB)

    Savaidis, G. [Aristotle Univ. of Thessaloniki, Dept. of Mechanical Engineering (Greece); Schwaiger, F. [MAN Nutzfahrzeuge AG, Munich (Germany); Momiyama, F.; Yamazumi, T.; Muramatsu, K. [Horikiri Inc., Chiba-Pref. (Japan)

    2004-07-01

    This paper deals with the development of a fatigue-accurate suspension system for large-sized trucks based on mono-leaf steel springs, It shows the fulfillment of the demands for lightweight construction, sufficient fatigue life and fail-safe behaviour. The paper contains the fatigue load assumptions used for the non-linear finite-element stress-strain analysis, the experimental verification by means of measured load, stress and strain data determined by driving quasi-static manoeuvres and over various rough road segments with a prototype vehicle, as well as the experimental uniaxial and multiaxial fatigue tests required for the durability approval. The fatigue lives achieved, confirm the adequate service life of the developed spring. In addition, appropriate vehicle tests on a test track with a custom-made mono-leaf spring system confirmed the fail-safe design of the suspension system. (orig.)

  14. Characterisation of Late Bronze Age large size shield nails by EDXRF, micro-EDXRF and X-ray digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, E., E-mail: elin@itn.pt [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Departamento de Conservacao e Restauro, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Araujo, M.F. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Silva, R.J.C. [CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Senna-Martinez, J.C. [Centro de Arqueologia (Uniarq), Faculdade de Letras, Universidade de Lisboa, 1600-214 Lisboa (Portugal); Ines Vaz, J.L. [Departamento de Letras, Universidade Catolica, Estrada da Circunvalacao, 3504-505 Viseu (Portugal)

    2011-09-15

    In the present study six exceptional large size metallic nails, a dagger and a sickle from the Late Bronze Age archaeological site of Figueiredo das Donas (Central Portugal) have been analysed by EDXRF, micro-EDXRF and X-ray digital radiography for the study of material composition and technology of fabrication. The combination of these analytical and examination techniques showed that all artefacts are made of bronze with As, Sb and Pb impurities, and that the nails were most likely manufactured using the casting-on technique. These results reinforce the use of binary bronze by Late Bronze Age in the region, and the incorporation of new fabrication technologies that resulted from ancient spheres of interaction. - Highlights: > EDXRF, micro-EDXRF and X-ray digital radiography in cultural heritage studies. > Archaeometallurgical study of a Late Bronze Age artefact collection from Portugal. > Practise of a specific and traditional bronze metallurgy. > Appearance of technological innovations as the casting-on technique.

  15. Growth of large size lithium niobate single crystals of high quality by tilting-mirror-type floating zone method

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Abdur Razzaque, E-mail: razzaque_ru2000@yahoo.com [Department of Physics, University of Rajshahi (Bangladesh)

    2016-05-15

    Large size high quality LiNbO{sub 3} single crystals were grown successfully by tilting-mirror-type floating zone (TMFZ) technique. The grown crystals were characterized by X-ray diffraction, etch pits density measurement, Impedance analysis, Vibrating sample magnetometry (VSM) and UV-Visible spectrometry. The effect of mirror tilting during growth on the structural, electrical, optical properties and defect density of the LiNbO{sub 3} crystals were investigated. It was found that the defect density in the crystals reduced for tilting the mirror in the TMFZ method. The chemical analysis revealed that the grown crystals were of high quality with uniform composition. The single crystals grown by TMFZ method contains no low-angle grain boundaries, indicating that they can be used for high efficiency optoelectronic devices. (author)

  16. Mechanics and cooling system for the camera of the Large Size Telescopes of the Cherenkov Telescope Array (CTA)

    CERN Document Server

    Delgado, Carlos; Diaz, Carlos; Hamer, Noemi; Hideyuki, Ohoka; Mirzoyan, Razmik; Teshima, Masahiro; Wetteskind, Holger

    2013-01-01

    Mechanics of the camera for the large size telescopes of CTA must protect and provide a stable environment for its instrumentation. This is achieved by a stiff support structure enclosed in an air and water tight volume. The structure is specially devised to facilitate extracting the power dissipated by the focal plane electronics while keeping its weight small enough to guarantee an optimum load on the telescope structure. A heat extraction system is designed to keep the electronics temperature within its optimal operation range, stable in time and homogeneous along the camera volume, whereas it is decoupled from the temperature in the telescope environment. In this contribution, we present the details of this system as well as its verification based in finite element analysis computations and tested prototypes. Finally, issues related to the integration of the camera mechanics and electronics will be dealt with.

  17. Characterisation of Late Bronze Age large size shield nails by EDXRF, micro-EDXRF and X-ray digital radiography.

    Science.gov (United States)

    Figueiredo, E; Araújo, M F; Silva, R J C; Senna-Martinez, J C; Vaz, J L Inês

    2011-09-01

    In the present study six exceptional large size metallic nails, a dagger and a sickle from the Late Bronze Age archaeological site of Figueiredo das Donas (Central Portugal) have been analysed by EDXRF, micro-EDXRF and X-ray digital radiography for the study of material composition and technology of fabrication. The combination of these analytical and examination techniques showed that all artefacts are made of bronze with As, Sb and Pb impurities, and that the nails were most likely manufactured using the casting-on technique. These results reinforce the use of binary bronze by Late Bronze Age in the region, and the incorporation of new fabrication technologies that resulted from ancient spheres of interaction.

  18. CAT 2 - An improved version of Cryogenic Analysis Tools for online and offline monitoring and analysis of large size cryostats

    Science.gov (United States)

    Pagliarone, C. E.; Uttaro, S.; Cappelli, L.; Fallone, M.; Kartal, S.

    2017-02-01

    CAT, Cryogenic Analysis Tools is a software package developed using LabVIEW and ROOT environments to analyze the performances of large size cryostats, where many parameters, input, and control variables need to be acquired and studied at the same time. The present paper describes how CAT works and which are the main improvements achieved in the new version: CAT 2. New Graphical User Interfaces have been developed in order to make the use of the full package more user-friendly as well as a process of resource optimization has been carried out. The offline analysis of the full cryostat performances is available both trough ROOT line command interface band also by using the new graphical interfaces.

  19. Long-term resource variation and group size: A large-sample field test of the Resource Dispersion Hypothesis

    Directory of Open Access Journals (Sweden)

    Morecroft Michael D

    2001-07-01

    Full Text Available Abstract Background The Resource Dispersion Hypothesis (RDH proposes a mechanism for the passive formation of social groups where resources are dispersed, even in the absence of any benefits of group living per se. Despite supportive modelling, it lacks empirical testing. The RDH predicts that, rather than Territory Size (TS increasing monotonically with Group Size (GS to account for increasing metabolic needs, TS is constrained by the dispersion of resource patches, whereas GS is independently limited by their richness. We conducted multiple-year tests of these predictions using data from the long-term study of badgers Meles meles in Wytham Woods, England. The study has long failed to identify direct benefits from group living and, consequently, alternative explanations for their large group sizes have been sought. Results TS was not consistently related to resource dispersion, nor was GS consistently related to resource richness. Results differed according to data groupings and whether territories were mapped using minimum convex polygons or traditional methods. Habitats differed significantly in resource availability, but there was also evidence that food resources may be spatially aggregated within habitat types as well as between them. Conclusions This is, we believe, the largest ever test of the RDH and builds on the long-term project that initiated part of the thinking behind the hypothesis. Support for predictions were mixed and depended on year and the method used to map territory borders. We suggest that within-habitat patchiness, as well as model assumptions, should be further investigated for improved tests of the RDH in the future.

  20. Intercomparison of Large-eddy Simulations of Arctic Mixed-phase Clouds: Importance of Ice Size Distribution Assumptions

    Energy Technology Data Exchange (ETDEWEB)

    Ovchinnikov, Mikhail; Ackerman, Andrew; Avramov, Alex; Cheng, Anning; Fan, Jiwen; Fridlind, Ann; Ghan, Steven J.; Harrington, Jerry Y.; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg; Morrison, H.; Paukert, Marco; Savre, Julien; Shipway, Ben; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-14

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP) and potential cloud dissipation, in agreement with earlier studies. By comparing simulations with the same microphysics coupled to different dynamical cores as well as the same dynamics coupled to different microphysics schemes, it is found that the ice water path (IWP) is mainly controlled by ice microphysics, while the inter-model differences in LWP are largely driven by physics and numerics of the dynamical cores. In contrast to previous intercomparisons, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSD) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case.

  1. ASIC-based architecture for the real-time computation of 2D convolution with large kernel size

    Science.gov (United States)

    Shao, Rui; Zhong, Sheng; Yan, Luxin

    2015-12-01

    Bidimensional convolution is a low-level processing algorithm of interest in many areas, but its high computational cost constrains the size of the kernels, especially in real-time embedded systems. This paper presents a hardware architecture for the ASIC-based implementation of 2-D convolution with medium-large kernels. Aiming to improve the efficiency of storage resources on-chip, reducing off-chip bandwidth of these two issues, proposed construction of a data cache reuse. Multi-block SPRAM to cross cached images and the on-chip ping-pong operation takes full advantage of the data convolution calculation reuse, design a new ASIC data scheduling scheme and overall architecture. Experimental results show that the structure can achieve 40× 32 size of template real-time convolution operations, and improve the utilization of on-chip memory bandwidth and on-chip memory resources, the experimental results show that the structure satisfies the conditions to maximize data throughput output , reducing the need for off-chip memory bandwidth.

  2. Development of a composite large-size SiPM (assembled matrix) based modular detector cluster for MAGIC

    Science.gov (United States)

    Hahn, A.; Mazin, D.; Bangale, P.; Dettlaff, A.; Fink, D.; Grundner, F.; Haberer, W.; Maier, R.; Mirzoyan, R.; Podkladkin, S.; Teshima, M.; Wetteskind, H.

    2017-02-01

    The MAGIC collaboration operates two 17 m diameter Imaging Atmospheric Cherenkov Telescopes (IACTs) on the Canary Island of La Palma. Each of the two telescopes is currently equipped with a photomultiplier tube (PMT) based imaging camera. Due to the advances in the development of Silicon Photomultipliers (SiPMs), they are becoming a widely used alternative to PMTs in many research fields including gamma-ray astronomy. Within the Otto-Hahn group at the Max Planck Institute for Physics, Munich, we are developing a SiPM based detector module for a possible upgrade of the MAGIC cameras and also for future experiments as, e.g., the Large Size Telescopes (LST) of the Cherenkov Telescope Array (CTA). Because of the small size of individual SiPM sensors (6 mm×6 mm) with respect to the 1-inch diameter PMTs currently used in MAGIC, we use a custom-made matrix of SiPMs to cover the same detection area. We developed an electronic circuit to actively sum up and amplify the SiPM signals. Existing non-imaging hexagonal light concentrators (Winston cones) used in MAGIC have been modified for the angular acceptance of the SiPMs by using C++ based ray tracing simulations. The first prototype based detector module includes seven channels and was installed into the MAGIC camera in May 2015. We present the results of the first prototype and its performance as well as the status of the project and discuss its challenges.

  3. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    factors and mis- guided axons into adjacent tissues further compromises outcome and likely contributes to neuroma formation. These effects are... effects on neurite outgrowth and can support axonal regeneration in the absence of SCs. Whilst this may be sufficient over short lengths of ANA... effective for nerve regeneration than autograft in clinical implementation using microsurgical attachment, we hypothesized that the photosealing benefit may

  4. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2014-10-01

    Nerve wrap biomaterials Human amniotic membrane was obtained from elective caesarean section patients who had been screened serologically for human...80°C until the day of surgery. Human amnion (HAM) harvest and processing Amniotic membrane was obtained from elective caesarean section patients

  5. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2016-12-01

    Photochemical bond- ing required clear access 5 mm proximal and dis- tal to coaptation sites. As a result, the maximum achievable nerve gap before...rodents for nerve gap reconstruction. Induction and maintenance anesthesia was achieved using isoflurane (Baxter Healthcare Corp., Deerfield, Ill...injury, nerve gap , nerve wrap, PTB, photosealing, Rose Bengal, amnion, nerve conduit, crosslinking, allograft, photochemistry. 3. Accomplishments

  6. THE ESO EXTREMELY LARGE TELESCOPE

    Directory of Open Access Journals (Sweden)

    J. Melnick

    2011-01-01

    Full Text Available Los instrumentos robóticos utilizados en campañas de evaluación de sitios generan una gran cantidad de información, esencialmente acerca de todos los parámentros relevantes de la atmósfera. Comenzando por suposiciones relativamente genéricas, es posible capturar esta riqueza de información en una figura sencilla de mérito para cada sitio, lo cual simplifica algunas de las etapas del proceso de evaluación de sitio. Esta contribución presenta dos formalismos diferentes que fueron usados para evaluar la función de mérito de selección de sitio para el E-ELT. Ambos formalismos recaen en suposiciones acerca de las formas en que se usará el telescopio -los modos científicos de operación- pero mientras un algoritmo calcula las figuras de mérito promediadas sobre todo el tiempo de la campaña de evaluación de sitio (típicamente 2 años, el otro explora la variabilidad de las condiciones de observación durante la noche, y de noche a noche durante la campaña. Se encontró que en general, los dos métodos arrojan resultados diferentes, señalando la importancia de incluir la variabilidad como un parámetro fundamental para caracterizar los sitios astronómicos para telescopios grandes operados en modo de programación de cola. Sin embargo, los dos mejores sitios potenciales para E-ELT están clasificados como mejores por ambos métodos.

  7. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2016-12-01

    71. Burman S, Tejwani S, Vemuganti GK. Ophthalmic applications of preserved human amniotic membrane: a review of current indications. Cell Tissue Bank...segmental nerve deficit repair using isograft show the best performing wrap/ fixation method to be sutureless photochemical tissue bonding with the...crosslinked amnion wrap. Autograft is often unavailable in wounded warriors, due to extensive tissue damage and amputation and, importantly, we also

  8. MANUFACTURING AND CONTINUOUS IMPROVEMENT PERFORMANCE LEVEL IN PLANTS OF MEXICO; A COMPARATIVE ANALYSIS AMONG LARGE AND MEDIUM SIZE PLANTS

    Directory of Open Access Journals (Sweden)

    Carlos Monge

    2015-12-01

    Full Text Available A random and statistically significant sample of 40 medium (12 and large (28 manufacturing plants of Apodaca, Mexico were surveyed using a structured and validated questionnaire to investigate the level of implementation of lean manufacturing, sustainable manufacturing, continuous improvement and operational efficiency and environmental responsibility in them, it is important to mention it was found that performance in the mentioned philosophies, on the two categories of plants is low, however large plants show a better performance than medium plants. In both cases, it is worrying that in the highly industrialized municipality of Apodaca,  Mexico are not decisively adopting the philosophies mentioned, as this compromises in a global world, in the medium and long term the viability of the plants, particularly the medium size plants. Finally this article shows the results of the answers to the items of questionnaire for the plants managers, and this can be useful to the management of the plants to identify and to define specific improvement actions towards priority areas.

  9. Single molecule kinetics of horseradish peroxidase exposed in large arrays of femtoliter-sized fused silica chambers.

    Science.gov (United States)

    Ehrl, Benno N; Liebherr, Raphaela B; Gorris, Hans H

    2013-08-07

    Large arrays of femtoliter-sized chambers were etched into the surface of fused silica slides to enclose and observe hundreds of single horseradish peroxidase (HRP) molecules in parallel. Individual molecules of HRP oxidize the fluorogenic substrate Amplex Red to fluorescent resorufin in separate chambers, which was monitored by fluorescence microscopy. Photooxidation of Amplex Red and photobleaching of resorufin have previously limited the analysis of HRP in femtoliter arrays. We have strongly reduced these effects by optimizing the fluorescence excitation and detection scheme to yield accurate single molecule substrate turnover rates. We demonstrate the presence of long-lived kinetic states of single HRP molecules that are individually different for each molecule in the array. The large number of molecules investigated in parallel provides excellent statistics on the activity distribution in the enzyme population, which is similar to that reported for other enzymes such as β-galactosidase. We have further confirmed that the product formation of HRP in femtoliter chambers is 10-fold lower than that in the bulk solution due to the particular two-step redox reaction mechanism of HRP.

  10. Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Masuda, Shu; Barrio, Juan Abel; Bigas, Oscar Blanch; Delgado, Carlos; Coromina, Lluís Freixas; Gunji, Shuichi; Hadasch, Daniela; Hatanaka, Kenichiro; Ikeno, Masahiro; Laguna, Jose Maria Illa; Inome, Yusuke; Ishio, Kazuma; Katagiri, Hideaki; Kubo, Hidetoshi; Martínez, Gustavo; Mazin, Daniel; Nakajima, Daisuke; Nakamori, Takeshi; Ohoka, Hideyuki; Paoletti, Riccardo; Ritt, Stefan; Rugliancich, Andrea; Saito, Takayuki; Sulanke, Karl-Heinz; Takeda, Junki; Tanaka, Manobu; Tanigawa, Shunsuke; Tejedor, Luis Ángel; Teshima, Masahiro; Tsuchiya, Yugo; Uchida, Tomohisa; Yamamoto, Tokonatsu

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is required so that the signal integration time can be as short as the Cherenkov light flash duration (a few ns). We have developed a readout board which samples waveforms of seven PMTs per board at a GHz rate. Since a GHz FADC has a high power consumption, leading to large heat dissipation, we adopted the analog memory ASIC "DRS4". The sampler has 1024 capacitors per channel and can sample the waveform at a GHz rate. Four channels of a chip are cascaded to obtain deeper sampling depth with 4096 capacitors. After a trigger ...

  11. An extremely large magnitude eruption close to the Plio-Pleistocene boundary: reconstruction of eruptive style and history of the Ebisutoge-Fukuda tephra, central Japan

    Science.gov (United States)

    Kataoka, K.; Nagahashi, Y.; Yoshikawa, S.

    2001-06-01

    An extremely large magnitude eruption of the Ebisutoge-Fukuda tephra, close to the Plio-Pleistocene boundary, central Japan, spread volcanic materials widely more than 290,000 km 2 reaching more than 300 km from the probable source. Characteristics of the distal air-fall ash (>150 km away from the vent) and proximal pyroclastic deposits are clarified to constrain the eruptive style, history, and magnitude of the Ebisutoge-Fukuda eruption. Eruptive history had five phases. Phase 1 is phreatoplinian eruption producing >105 km 3 of volcanic materials. Phases 2 and 3 are plinian eruption and transition to pyroclastic flow. Plinian activity also occurred in phase 4, which ejected conspicuous obsidian fragments to the distal locations. In phase 5, collapse of eruption column triggered by phase 4, generated large pyroclastic flow in all directions and resulted in more than 250-350 km 3 of deposits. Thus, the total volume of this tephra amounts over 380-490 km 3. This indicates that the Volcanic Explosivity Index (VEI) of the Ebisutoge-Fukuda tephra is greater than 7. The huge thickness of reworked volcaniclastic deposits overlying the fall units also attests to the tremendous volume of eruptive materials of this tephra. Numerous ancient tephra layers with large volume have been reported worldwide, but sources and eruptive history are often unknown and difficult to determine. Comparison of distal air-fall ashes with proximal pyroclastic deposits revealed eruption style, history and magnitude of the Ebisutoge-Fukuda tephra. Hence, recognition of the Ebisutoge-Fukuda tephra, is useful for understanding the volcanic activity during the Pliocene to Pleistocene, is important as a boundary marker bed, and can be used to interpret the global environmental and climatic impact of large magnitude eruptions in the past.

  12. Controllable fabrication of large-area 2D colloidal crystal masks with large size defect-free domains based on statistical experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yajuan, E-mail: yajuan@kth.se; Jönsson, Pär Göran; Zhao, Zhe, E-mail: zhezhao@kth.se

    2014-09-15

    Highlights: • 3000 μm{sup 2} defect-free HCP domain was successfully synthesized. • Relative humidity (RH) as well as the first rotational speed (v{sub a}) of the dual-speed procedure was identified as the quality-control parameters in spin coating. • 23% RH and v{sub a} = 1000 rpm were identified as the optimistic spin coating processing parameters for SiO{sub 2} HCP monolayer. • Statistical experimental design was demonstrated as one efficient strategy for multi-factor processing optimization. - Abstract: A large-area hexagonal packed monolayer of silica spheres with consistent defect-free domains of a size larger than 3000 μm{sup 2} was prepared by spin coating on glass substrates with the assistance of experimental design and statistical analysis. The ratio of the defect-free monolayer area to the square of sphere diameter is nearly two times of the previously reported maximum values. Several parameters involved in the spin coating systems were investigated. The results indicated that the relative humidity and the rotational speed of the first step of the spin coating had the most important impact on the ordering degree of the prepared monolayer. Furthermore, the ordering degree of the obtained monolayer increased with a decreased relative humidity. In addition, it reached an optimal value when the first rotational speed during spin coating reached a value of 1000 rpm. From this study, it can be concluded that statistical experimental design is an efficient strategy, especially for multi-factor phenomenon studies.

  13. Are rheumatoid arthritis patients discernible from other early arthritis patients using 1.5T extremity magnetic resonance imaging? a large cross-sectional study.

    Science.gov (United States)

    Stomp, Wouter; Krabben, Annemarie; van der Heijde, Désirée; Huizinga, Tom W J; Bloem, Johan L; van der Helm-van Mil, Annette H M; Reijnierse, Monique

    2014-08-01

    Magnetic resonance imaging (MRI) is increasingly used in rheumatoid arthritis (RA) research. A European League Against Rheumatism (EULAR) task force recently suggested that MRI can improve the certainty of RA diagnosis. Because this recommendation may reflect a tendency to use MRI in daily practice, thorough studies on the value of MRI are required. Thus far no large studies have evaluated the accuracy of MRI to differentiate early RA from other patients with early arthritis. We performed a large cross-sectional study to determine whether patients who are clinically classified with RA differ in MRI features compared to patients with other diagnoses. In our study, 179 patients presenting with early arthritis (median symptom duration 15.4 weeks) underwent 1.5T extremity MRI of unilateral wrist, metacarpophalangeal, and metatarsophalangeal joints according to our arthritis protocol, the foot without contrast. Images were scored according to OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) by 2 independent readers. Tenosynovitis was also assessed. The main outcome was fulfilling the 1987 American College of Rheumatology (ACR) criteria for RA. Test characteristics and areas under the receiver-operator-characteristic curves (AUC) were evaluated. In subanalyses, the 2010 ACR/EULAR criteria were used as outcome, and analyses were stratified for anticitrullinated protein antibodies (ACPA). The ACR 1987 criteria were fulfilled in 43 patients (24.0%). Patients with RA had higher scores for synovitis, tenosynovitis, and bone marrow edema (BME) than patients without RA (p arthritis patients.

  14. Growing vertical ZnO nanorod arrays within graphite: efficient isolation of large size and high quality single-layer graphene.

    Science.gov (United States)

    Ding, Ling; E, Yifeng; Fan, Louzhen; Yang, Shihe

    2013-07-18

    We report a unique strategy for efficiently exfoliating large size and high quality single-layer graphene directly from graphite into DMF dispersions by growing ZnO nanorod arrays between the graphene layers in graphite.

  15. Intercomparison of large-eddy simulations of Arctic mixed-phase clouds: Importance of ice size distribution assumptions

    Science.gov (United States)

    Ovchinnikov, Mikhail; Ackerman, Andrew S.; Avramov, Alexander; Cheng, Anning; Fan, Jiwen; Fridlind, Ann M.; Ghan, Steven; Harrington, Jerry; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg M.; Morrison, Hugh; Paukert, Marco; Savre, Julien; Shipway, Ben J.; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-01

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP), in agreement with earlier studies. In contrast to previous intercomparison studies, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSDs) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case. Sensitivity tests indicate LWP and IWP are much closer to the bin model simulations when a modified shape factor which is similar to that predicted by bin model simulation is used in bulk scheme. These results demonstrate the importance of representation of ice PSD in determining the partitioning of liquid and ice and the longevity of mixed-phase clouds.

  16. Intercomparison of Large-Eddy Simulations of Arctic Mixed-Phase Clouds: Importance of Ice Size Distribution Assumptions

    Science.gov (United States)

    Ovchinnikov, Mikhail; Ackerman, Andrew S.; Avramov, Alexander; Cheng, Anning; Fan, Jiwen; Fridlind, Ann M.; Ghan, Steven; Harrington, Jerry; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg M.; Morrison, Hugh; Paukert, Marco; Savre, Julien; Shipway, Ben J.; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-01-01

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP), in agreement with earlier studies. In contrast to previous intercomparison studies, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSDs) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case. Sensitivity tests indicate LWP and IWP are much closer to the bin model simulations when a modified shape factor which is similar to that predicted by bin model simulation is used in bulk scheme. These results demonstrate the importance of representation of ice PSD in determining the partitioning of liquid and ice and the longevity of mixed-phase clouds.

  17. Extending ALE3D, an Arbitrarily Connected hexahedral 3D Code, to Very Large Problem Size (U)

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, A L

    2010-12-15

    As the number of compute units increases on the ASC computers, the prospect of running previously unimaginably large problems is becoming a reality. In an arbitrarily connected 3D finite element code, like ALE3D, one must provide a unique identification number for every node, element, face, and edge. This is required for a number of reasons, including defining the global connectivity array required for domain decomposition, identifying appropriate communication patterns after domain decomposition, and determining the appropriate load locations for implicit solvers, for example. In most codes, the unique identification number is defined as a 32-bit integer. Thus the maximum value available is 231, or roughly 2.1 billion. For a 3D geometry consisting of arbitrarily connected hexahedral elements, there are approximately 3 faces for every element, and 3 edges for every node. Since the nodes and faces need id numbers, using 32-bit integers puts a hard limit on the number of elements in a problem at roughly 700 million. The first solution to this problem would be to replace 32-bit signed integers with 32-bit unsigned integers. This would increase the maximum size of a problem by a factor of 2. This provides some head room, but almost certainly not one that will last long. Another solution would be to replace all 32-bit int declarations with 64-bit long long declarations. (long is either a 32-bit or a 64-bit integer, depending on the OS). The problem with this approach is that there are only a few arrays that actually need to extended size, and thus this would increase the size of the problem unnecessarily. In a future computing environment where CPUs are abundant but memory relatively scarce, this is probably the wrong approach. Based on these considerations, we have chosen to replace only the global identifiers with the appropriate 64-bit integer. The problem with this approach is finding all the places where data that is specified as a 32-bit integer needs to be

  18. How great white sharks nourish their embryos to a large size: evidence of lipid histotrophy in lamnoid shark reproduction.

    Science.gov (United States)

    Sato, Keiichi; Nakamura, Masaru; Tomita, Taketeru; Toda, Minoru; Miyamoto, Kei; Nozu, Ryo

    2016-09-15

    The great white shark (Carcharodon carcharias) exhibits viviparous and oophagous reproduction. A 4950 mm total length (TL) gravid female accidentally caught by fishermen in the Okinawa Prefecture, Southern Japan carried six embryos (543-624 mm TL, three in each uterus). Both uteri contained copious amounts of yellowish viscous uterine fluid (over 79.2 litres in the left uterus), nutrient eggs and broken egg cases. The embryos had yolk stomachs that had ruptured, the mean volume of which was approximately 197.9 ml. Embryos had about 20 rows of potentially functional teeth in the upper and lower jaws. Periodic acid Schiff (PAS)-positive substances were observed on the surface and in the cytoplasm of the epithelial cells, and large, secretory, OsO4-oxidized lipid droplets of various sizes were distributed on the surface of the villous string epithelium on the uterine wall. Histological examination of the uterine wall showed it to consist of villi, similar to the trophonemata of Dasyatidae rays, suggesting that the large amount of fluid found in the uterus of the white shark was likely required for embryo nutrition. We conclude that: (1) the lipid-rich fluid is secreted from the uterine epithelium only in early gestation before the onset of oophagy, (2) the embryos probably use the abundant uterine fluid and encased nutrient eggs for nutrition at this stage of their development, and (3) the uterine fluid is the major source of embryonic nutrition before oophagy onset. This is the first record of the lipid histotrophy of reproduction among all shark species.

  19. How great white sharks nourish their embryos to a large size: evidence of lipid histotrophy in lamnoid shark reproduction

    Directory of Open Access Journals (Sweden)

    Keiichi Sato

    2016-09-01

    Full Text Available The great white shark (Carcharodon carcharias exhibits viviparous and oophagous reproduction. A 4950 mm total length (TL gravid female accidentally caught by fishermen in the Okinawa Prefecture, Southern Japan carried six embryos (543-624 mm TL, three in each uterus. Both uteri contained copious amounts of yellowish viscous uterine fluid (over 79.2 litres in the left uterus, nutrient eggs and broken egg cases. The embryos had yolk stomachs that had ruptured, the mean volume of which was approximately 197.9 ml. Embryos had about 20 rows of potentially functional teeth in the upper and lower jaws. Periodic acid Schiff (PAS-positive substances were observed on the surface and in the cytoplasm of the epithelial cells, and large, secretory, OsO4-oxidized lipid droplets of various sizes were distributed on the surface of the villous string epithelium on the uterine wall. Histological examination of the uterine wall showed it to consist of villi, similar to the trophonemata of Dasyatidae rays, suggesting that the large amount of fluid found in the uterus of the white shark was likely required for embryo nutrition. We conclude that: (1 the lipid-rich fluid is secreted from the uterine epithelium only in early gestation before the onset of oophagy, (2 the embryos probably use the abundant uterine fluid and encased nutrient eggs for nutrition at this stage of their development, and (3 the uterine fluid is the major source of embryonic nutrition before oophagy onset. This is the first record of the lipid histotrophy of reproduction among all shark species.

  20. Long‐term creep rates on the Hayward Fault: evidence for controls on the size and frequency of large earthquakes

    Science.gov (United States)

    Lienkaemper, James J.; McFarland, Forrest S.; Simpson, Robert W.; Bilham, Roger; Ponce, David A.; Boatwright, John; Caskey, S. John

    2012-01-01

    The Hayward fault (HF) in California exhibits large (Mw 6.5–7.1) earthquakes with short recurrence times (161±65 yr), probably kept short by a 26%–78% aseismic release rate (including postseismic). Its interseismic release rate varies locally over time, as we infer from many decades of surface creep data. Earliest estimates of creep rate, primarily from infrequent surveys of offset cultural features, revealed distinct spatial variation in rates along the fault, but no detectable temporal variation. Since the 1989 Mw 6.9 Loma Prieta earthquake (LPE), monitoring on 32 alinement arrays and 5 creepmeters has greatly improved the spatial and temporal resolution of creep rate. We now identify significant temporal variations, mostly associated with local and regional earthquakes. The largest rate change was a 6‐yr cessation of creep along a 5‐km length near the south end of the HF, attributed to a regional stress drop from the LPE, ending in 1996 with a 2‐cm creep event. North of there near Union City starting in 1991, rates apparently increased by 25% above pre‐LPE levels on a 16‐km‐long reach of the fault. Near Oakland in 2007 an Mw 4.2 earthquake initiated a 1–2 cm creep event extending 10–15 km along the fault. Using new better‐constrained long‐term creep rates, we updated earlier estimates of depth to locking along the HF. The locking depths outline a single, ∼50‐km‐long locked or retarded patch with the potential for an Mw∼6.8 event equaling the 1868 HF earthquake. We propose that this inferred patch regulates the size and frequency of large earthquakes on HF.

  1. Performance of a large size triple GEM detector at high particle rate for the CBM Experiment at FAIR

    Science.gov (United States)

    Adak, Rama Prasad; Kumar, Ajit; Dubey, Anand Kumar; Chattopadhyay, Subhasis; Das, Supriya; Raha, Sibaji; Samanta, Subhasis; Saini, Jogender

    2017-02-01

    In CBM Experiment at FAIR, dimuons will be detected by a Muon Chamber (MUCH) consisting of segmented absorbers of varying widths and tracking chambers sandwiched between the absorber-pairs. In this fixed target heavy-ion collision experiment, operating at highest interaction rate of 10 MHz for Au+Au collision, the inner region of the 1st detector will face a particle rate of 1 MHz/cm2. To operate at such a high particle density, GEM technology based detectors have been selected for the first two stations of MUCH. We have reported earlier the performance of several small-size GEM detector prototypes built at VECC for use in MUCH. In this work, we report on a large GEM prototype tested with proton beam of momentum 2.36 GeV/c at COSY-Jülich Germany. The detector was read out using nXYTER operated in self-triggering mode. An efficiency higher than 96% at ΔVGEM = 375.2 V was achieved. The variation of efficiency with the rate of incoming protons has been found to vary within 2% when tested up to a maximum rate of 2.8 MHz/cm2. The gain was found to be stable at high particle rate with a maximum variation of ∼9%.

  2. Depletion of trophy large-sized sharks populations of the Argentinean coast, south-western Atlantic: insights from fishers' knowledge

    Directory of Open Access Journals (Sweden)

    Alejo Irigoyen

    Full Text Available Abstract Globally, sharks are impacted by a wide range of human activities, resulting in many populations being depleted. Trophy large-sized sharks of the Argentinean coast, the sand-tiger Carcharias taurus , the copper Carcharhinus brachyurus and the sevengill shark Notorynchus cepedianus are under intense sport and artisanal fishing since the 50's decade. However, the current and historical information for the assessment of its populations status is scarce. The aim of this work was to analyze the status of conservation of these species through the gathering of expert fishermen knowledge (FK on semi-structured interviews. Abundance variation perception between the beginning and the end of fishermen careers revealed a critical status for the species study (means variation between -77 and -90 %. Furthermore, a best day's catch analysis reinforce this result in the case of the sand tiger shark. The school shark Galeorhinus galeus was included on this work with the objective of contrast FK with formal information available of catch-per-unit-effort (CPUE time series. Both sources of information, despite are not comparable, shows declines ~ - 80%. The critical conservation situation of study species needs urgent management action, particularly for the san tiger shark which could became regionally extinct before the reaction of stakeholders occurs.

  3. Boys who pee the farthest have a large hollow head, a thin skin, and medium-size manhood

    Science.gov (United States)

    Attinger, Daniel; Lee, Vincent

    2016-11-01

    Following a recent trend of scientific studies on artwork, we study here the thermodynamics of a jetting thermometer made of ceramic, related to the Chinese tea culture. The thermometer represents a boy who "urinates" shortly after hot water is poured onto his head. Long jetting distance indicates if the water temperature is hot enough to brew tea. Here, a thermofluid model describes the jetting phenomenon of that pee-pee boy. The study demonstrates how thermal expansion of an interior air pocket causes jetting. The validity of assumptions underlying the Hagen-Poiseuille flow is discussed for urethra of finite length. A thermodynamic potential is shown to define maximum jetting velocity. Seven optimization criteria to maximize jetting distance are provided, including two dimensionless numbers. The dimensionless numbers are obtained by comparing the time scales of the internal pressure buildup due to heating, with that of pressure relief due to jetting. Optimization results show that longer jets are produced by large individuals, with low body mass index, with a boyhood of medium size inclined at an angle π/4. Analogies are drawn with pissing contests among humans and lobsters. The study ends by noting similitudes of working principle between that politically incorrect thermometer and Galileo Galilei's thermoscope.

  4. Age-related changes in resting-state networks of a large sample size of healthy elderly.

    Science.gov (United States)

    Huang, Chun-Chao; Hsieh, Wen-Jin; Lee, Pei-Lin; Peng, Li-Ning; Liu, Li-Kuo; Lee, Wei-Ju; Huang, Jon-Kway; Chen, Liang-Kung; Lin, Ching-Po

    2015-10-01

    Population aging is burdening the society globally, and the evaluation of functional networks is the key toward understanding cognitive changes in normal aging. However, the effect of age on default mode subnetworks has not been documented well, and age-related changes in many resting-state networks remain debatable. The purpose of this study was to propose more precise results for these issues using a large sample size. We used group-level meta-ICA analysis and dual regression approach for identifying resting-state networks from functional magnetic resonance imaging data of 430 healthy elderly participants. Partial correlation was used to observe age-related correlations within and between resting-state networks. In the default mode network, only the ventral subnetwork negatively correlated with age. Age-related decrease in functional connectivity was also noted in the auditory, right frontoparietal, sensorimotor, and visual medial networks. Further, some age-related increases and decreases were observed for between-network correlations. The results of this study suggest that only the ventral default mode subnetwork had age-related decline in functional connectivity and several reverse patterns of resting-state networks for network development. Understanding age-related network changes may provide solutions for the impact of population aging and diagnosis of neurodegenerative diseases. © 2015 John Wiley & Sons Ltd.

  5. Consecutive Short-Scan CT for Geological Structure Analog Models with Large Size on In-Situ Stage

    Science.gov (United States)

    Yang, Min; Zhang, Wen; Wu, Xiaojun; Wei, Dongtao; Zhao, Yixin; Zhao, Gang; Han, Xu; Zhang, Shunli

    2016-01-01

    For the analysis of interior geometry and property changes of a large-sized analog model during a loading or other medium (water or oil) injection process with a non-destructive way, a consecutive X-ray computed tomography (XCT) short-scan method is developed to realize an in-situ tomography imaging. With this method, the X-ray tube and detector rotate 270° around the center of the guide rail synchronously by switching positive and negative directions alternately on the way of translation until all the needed cross-sectional slices are obtained. Compared with traditional industrial XCTs, this method well solves the winding problems of high voltage cables and oil cooling service pipes during the course of rotation, also promotes the convenience of the installation of high voltage generator and cooling system. Furthermore, hardware costs are also significantly decreased. This kind of scanner has higher spatial resolution and penetrating ability than medical XCTs. To obtain an effective sinogram which matches rotation angles accurately, a structural similarity based method is applied to elimination of invalid projection data which do not contribute to the image reconstruction. Finally, on the basis of geometrical symmetry property of fan-beam CT scanning, a whole sinogram filling a full 360° range is produced and a standard filtered back-projection (FBP) algorithm is performed to reconstruct artifacts-free images. PMID:27537104

  6. Design of a prototype device to calibrate the Large Size Telescope camera of the Cherenkov Telescope Array

    CERN Document Server

    Iori, M; De Persio, F; Chatterjee, A; Ferrarotto, F; Nagesh, B K; Saha, L; Singh, B B

    2015-01-01

    The Cherenkov Telescope Array is a project that aims to exploring the highest energy region of electromagnetic spectrum. Two arrays, one for each hemisphere, will cover the full sky in a range from few tens of GeV to hundreds of TeV improving the sensitivity and angular resolution of the present operating arrays. A prototype of the Large Size Telescope (LST) for the study of gamma ray astronomy above some tens of GeV will be installed at the Canary Island of La Palma in 2016. The LST camera, made by an array of photomultipliers (PMTs), requires an accurate and systematic calibration over a wide dynamic range. In this contribution, we present an optical calibration system made by a 355 nm wavelength laser with 400 ps pulse width, 1 muJ output energy, up to 4k Hz repetition rate and a set of neutral density filters to obtain a wide range of photon intensities, up to 1000 photoelectrons/PMT, to be sent to the camera plane 28 m away. The number of photons after the diffuser of the calibration box, located in the ...

  7. Size-exclusion chromatography of large molecules from coal liquids, petroleum residues, soots, biomass tars and humic substances.

    Science.gov (United States)

    Herod, Alan A; Zhuo, Yuqun; Kandiyoti, Rafael

    2003-06-30

    Size-exclusion chromatography (SEC) using 1-methyl-2-pyrrolidinone (NMP) as eluent has been calibrated using various standard polymers and model compounds and applied to the analysis of extracts of coal, petroleum and kerogens, to petroleum vacuum residues, soots, biomass tars and humic substances. Three separate columns of different molecular mass (MM) ranges were used, with detection by UV absorption; an evaporative light scattering detector was used for samples with no UV absorption. Fractionation was useful to separate signal from the less abundant high-mass material, which was normally masked by the strong signal from the more abundant low-mass material in the absence of fractionation. Fractionation methods used to isolate high-mass materials before SEC analysis included planar chromatography, column chromatography and solvent solubility. The apparently large molecules were concentrated into the fractions not soluble in common solvents and were relatively immobile in planar chromatography. All samples and fractions contained some material excluded from the column porosity. Evidence from other techniques suggests that the excluded material is of different structures from that of the resolved material rather than consisting of aggregates of small molecules. We speculate that the excluded material may elute early because the structures of this material are three-dimensional rather than planar or near planar.

  8. Evolution of grain size distribution in high-redshift dusty quasars: Integrating large amounts of dust and unusual extinction curves

    CERN Document Server

    Nozawa, Takaya; Hirashita, Hiroyuki; Takeuchi, Tsutomu T

    2014-01-01

    The discoveries of huge amounts of dust and unusual extinction curves in high-redshift quasars (z > 4) cast challenging issues on the origin and properties of dust in the early universe. In this Letter, we investigate the evolutions of dust content and extinction curve in a high-z quasar, based on the dust evolution model taking account of grain size distribution. First, we show that the Milky-Way extinction curve is reproduced by introducing a moderate fraction (~0.2) of dense molecular-cloud phases in the interstellar medium for a graphite-silicate dust model. Then we show that the peculier extinction curves in high-z quasars can be explained by taking a much higher molecular-cloud fraction (>0.5), which leads to more efficient grain growth and coagulation, and by assuming amorphous carbon instead of graphite. The large dust content in high-z quasar hosts is also found to be a natural consequence of the enhanced dust growth. These results indicate that grain growth and coagulation in molecular clouds are ke...

  9. Problems and Countermeasures of Colloquial English Large Size Class Teach-ing of Higher Vocational Public English under the Constructivism Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-ping

    2014-01-01

    Based on the theory of constructivism, this article analyzes the open problems colloquial English large size class teach-ing of higher vocational public English and points out the countermeasures of colloquial English large-scale class teaching of high-er vocational public English.

  10. Effects of Large Class Size on Effective Teaching and Learning at the Winneba Campus of the UEW (University of Education, Winneba), Ghana

    Science.gov (United States)

    Yelkpieri, Daniel; Namale, Matthew; Esia-Donkoh, Kweku; Ofosu-Dwamena, Eric

    2012-01-01

    Large class size is one of the problems in the educational sector that developing nations have been grappling with. Ghana as a developing nation is no exception and has its own fair share of this problem at the pre-tertiary and tertiary levels of education. The sight of large class at the tertiary level is appalling and a headache to teachers at…

  11. The main postulates of adaptive correction of distortions of the wave front in large-size optical systems

    Directory of Open Access Journals (Sweden)

    V. V. Sychev

    2014-01-01

    Full Text Available In the development of optical telescopes, striving to increase the penetrating power of a telescope has been always the main trend. A real way to solve this problem is to raise the quality of the image (reduction of the image angular size under real conditions of distorting factor and increase a diameter of the main mirror. This is counteracted by the various distorting factors or interference occurring in realtime use of telescopes, as well as by complicated manufacturing processes of large mirrors.It is shown that the most effective method to deal with the influence of distorting factors on the image quality in the telescope is the minimization (through selecting the place to mount a telescope and choosing the rational optical scheme, creating materials and new technologies, improving a design, unloading the mirrors, mounting choice, etc., and then the adaptive compensation of remaining distortions.It should be noted that a domestic concept to design large-sized telescopes allows us to use, in our opinion, the most efficient ways to do this. It means to abandon the creation of "an absolutely rigid and well-ordered" design, providing the passively aligned state telescope optics under operating conditions. The design must just have such a level of residual deformations that their effect can be efficiently compensated by the adaptive system using the segmented elements of the primary mirror and the secondary mirror as a corrector.It has been found that in the transmission optical systems to deliver laser power to a remote object, it is necessary not only to overcome the distorting effect of factors inherent in optical information systems, but, additionally, find a way to overcome a number of new difficulties. The main ones have been identified to be as follows:• the influence of laser radiation on the structure components and the propagation medium and, as a consequence, the opposite effect of the structure components and the propagation

  12. Extremely large electronic anisotropy caused by electronic phase separation in Ca3(Ru0.97Ti0.03)2O7 single crystal

    Science.gov (United States)

    Peng, Jing; Wu, Xiaoshan; Mao, Zhiqiang

    2015-03-01

    Bilayered ruthenate Ca3 Ru2O7 exhibits rich electronic and magnetic properties. It orders at 56K, with FM bilayers antiferromagnetically coupled along c-axis (AFM-a). The AFM transition is closely followed by a first-order metal-insulator (MI) transition at 48K where spin directions switch to the b-axis (AFM-b). While this MI transition is accompanied by the opening of anisotropic charge gap; small Fermi pockets survive from the MI transition, thus resulting in quasi-2D metallic transport behavior for Tinsulating state with a nearest-neighbor AFM order via Ti doping. Ca3(Ru0 . 97 Ti0 . 03) 2O7 is close to the critical composition for the AFM-b-to-G-AFM phase transition. Our recent studies show the sample with this composition is characterized by an electronic phase separation between the insulating G-AFM phase (major) and the localized AFM-b phase (minor). The minor AFM-b phase forms a conducting path through electronic percolation within the ab-plane, but not along the c-axis, thus resulting in extremely large electronic anisotropy with ρab /ρc ~109 , which may be the largest among bulk materials.

  13. Fabrication of large flat gallium nitride templates with extremely low dislocation densities in the 106 cm-2 range by novel two-side hydride vapor-phase epitaxial growth

    Science.gov (United States)

    Fujikura, Hajime; Konno, Taichiro

    2017-10-01

    Large GaN templates with high flatness (i.e., negligible wafer bowing and smooth as-grown surfaces) and low threading dislocation densities (TTDs) were fabricated by a novel two-side hydride vapor-phase epitaxial (HVPE) growth, beginning with deposition of polycrystalline GaN on the rear side of the wafer. Appropriate gas-flow management realized by our homemade HVPE system permitted the growth of a GaN layer with a smooth as-grown surface and excellent thickness uniformity on the front surfaces of 4- or 6-inch patterned sapphire substrates (PSSs). However, when the grown thickness exceeded 20 μm, single-side HVPE-growth induced fractures in GaN crystals. The fracture resistance of the GaN increased markedly when it was in a cleavage-resistant polycrystalline form (poly-GaN), permitting its growth to a thickness of 100 μm. In the presence of a back-side poly-GaN layer, extremely thick GaN crystal layers could be grown on the front side without fractures. An 80-μm-thick GaN template fabricated by two-side growth on a 4-inch PSS had a device-quality surface, negligible bowing, and low TDD (7 × 106 cm-2). Issues of high fabrication costs, unavailability of large-size wafers, and large off-angle variations associated with native GaN wafers could be overcome by using our high-quality GaN templates as alternative substrates.

  14. Extreme Heat

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  15. Extreme winter warming events more negatively impact small rather than large soil fauna: shift in community composition explained by traits not taxa

    NARCIS (Netherlands)

    Bokhorst, S.; Phoenix, G.K.; Berke, J.W.; Callaghan, T.V.; Huyer-Brugman, F.; Berg, M.P.

    2012-01-01

    Extreme weather events can have negative impacts on species survival and community structure when surpassinglethal thresholds. Extreme winter warming events in the Arctic rapidly melt snow and expose ecosystems to unseasonablywarm air (2–10 °C for 2–14 days), but returning to cold winter climate exp

  16. 牵拉成骨技术治疗下肢大段骨缺损%Distraction osteogenesis for large bone defect of the lower extremity

    Institute of Scientific and Technical Information of China (English)

    王富明; 陈鸿奋; 陈滨; 任高宏; 杨运平; 秦煜; 王钢

    2011-01-01

    Objective To discuss the therapeutic effect of distraction osteogenesis for large bone defect of the lower extremity. Methods From August 2002 to August 2010, 11 patients with large bone defect at the lower extremity were treated with distraction osteogenesis. They were 10 men and one woman, aged from 14 to 53 years (average, 34. S years). The defect was at the right tibia in 7 cases, left tibia in 3 cases and right femur in one case. The lengths of bone defect ranged from 5 to 15 cm (average, 8. 6 cm). Results The patients were followed up for 7 to 48 months, with a mean period of 27. 3 months. The treatment of 9 cases was over, with a mean healing index of 1. 99 months/cm. According to the Paley evaluation system, the bony results were excellent in 6 and good in 3 patients; the functional results were excellent in 4, good in 4, and fair in one patient. Two cases were still in the mineralization period. Conclusion Treatment of large bone defects with distraction osteogenesis is simple and can obtain satisfactory therapeutic effects, especially when a monolateral external fixator is used for the simple shaft bone defect.%目的 探讨应用牵拉成骨技术治疗下肢大段骨缺损的临床疗效.方法 回顾性分析2002年8月至2010年8月收治的11例下肢大段骨缺损患者临床资料,男10例,女1例;年龄14~53岁,平均34.5岁.均行牵拉成骨治疗,右侧胫骨7例,左侧胫骨3例,右侧股骨1例;骨缺损长度5~15cm,平均8.6 cm;9例治疗已结束,2例仍处于矿化阶段.结果 所有患者术后获7~48个月(平均27.3个月)随访.9例治疗结束患者,平均骨愈合指数为1.99个月/cm;根据Paley评价系统评价骨性结果:优6例,良3例,优良率为100%;功能结果:优4例,良4例,一般1例.结论应用牵拉成骨技术治疗大段骨缺损,手术操作简单,尤其是对于单纯骨干缺损患者,采用单边外固定支架治疗,且其手术操作更为简洁.

  17. Analysis of Large Seeds from Three Different Medicago truncatula Ecotypes Reveals a Potential Role of Hormonal Balance in Final Size Determination of Legume Grains

    Directory of Open Access Journals (Sweden)

    Kaustav Bandyopadhyay

    2016-09-01

    Full Text Available Legume seeds are important as protein and oil source for human diet. Understanding how their final seed size is determined is crucial to improve crop yield. In this study, we analyzed seed development of three accessions of the model legume, Medicago truncatula, displaying contrasted seed size. By comparing two large seed accessions to the reference accession A17, we described mechanisms associated with large seed size determination and potential factors modulating the final seed size. We observed that early events during embryogenesis had a major impact on final seed size and a delayed heart stage embryo development resulted to large seeds. We also observed that the difference in seed growth rate was mainly due to a difference in embryo cell number, implicating a role of cell division rate. Large seed accessions could be explained by an extended period of cell division due to a longer embryogenesis phase. According to our observations and recent reports, we observed that auxin (IAA and abscisic acid (ABA ratio could be a key determinant of cell division regulation at the end of embryogenesis. Overall, our study highlights that timing of events occurring during early seed development play decisive role for final seed size determination.

  18. Analysis of Large Seeds from Three Different Medicago truncatula Ecotypes Reveals a Potential Role of Hormonal Balance in Final Size Determination of Legume Grains

    Science.gov (United States)

    Bandyopadhyay, Kaustav; Uluçay, Orhan; Şakiroğlu, Muhammet; Udvardi, Michael K.; Verdier, Jerome

    2016-01-01

    Legume seeds are important as protein and oil source for human diet. Understanding how their final seed size is determined is crucial to improve crop yield. In this study, we analyzed seed development of three accessions of the model legume, Medicago truncatula, displaying contrasted seed size. By comparing two large seed accessions to the reference accession A17, we described mechanisms associated with large seed size determination and potential factors modulating the final seed size. We observed that early events during embryogenesis had a major impact on final seed size and a delayed heart stage embryo development resulted to large seeds. We also observed that the difference in seed growth rate was mainly due to a difference in embryo cell number, implicating a role of cell division rate. Large seed accessions could be explained by an extended period of cell division due to a longer embryogenesis phase. According to our observations and recent reports, we observed that auxin (IAA) and abscisic acid (ABA) ratio could be a key determinant of cell division regulation at the end of embryogenesis. Overall, our study highlights that timing of events occurring during early seed development play decisive role for final seed size determination. PMID:27618017

  19. Mandelbrot's Extremism

    NARCIS (Netherlands)

    Beirlant, J.; Schoutens, W.; Segers, J.J.J.

    2004-01-01

    In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

  20. Genotype and fetal size affect maternal-fetal amino acid status and fetal endocrinology in Large White × Landrace and Meishan pigs.

    Science.gov (United States)

    Ashworth, Cheryl J; Nwagwu, Margaret O; McArdle, Harry J

    2013-01-01

    This study compared maternal plasma amino acid concentrations, placental protein secretion in vitro and fetal body composition and plasma amino acid and hormone concentrations in feto-placental units from the smallest and a normally-sized fetus carried by Large White × Landrace or Meishan gilts on Day 100 of pregnancy. Compared with Large White × Landrace, Meishan placental tissue secreted more protein and Meishan fetuses contained relatively more fat and protein, but less moisture. Fetal plasma concentrations of insulin, triiodothryonine, thyroxine and insulin-like growth factor (IGF)-II were higher in Meishan than Large White × Landrace fetuses. In both breeds, fetal cortisol concentrations were inversely related to fetal size, whereas concentrations of IGF-I were higher in average-sized fetuses. Concentrations of 10 amino acids were higher in Large White × Landrace than Meishan gilts, while glutamine concentrations were higher in Meishan gilts. Concentrations of alanine, aspartic acid, glutamic acid and threonine were higher in Meishan than Large White × Landrace fetuses. Average-sized fetuses had higher concentrations of asparagine, leucine, lysine, phenylalanine, threonine, tyrosine and valine than the smallest fetus. This study revealed novel genotype and fetal size differences in porcine maternal-fetal amino acid status and fetal hormone and metabolite concentrations.