WorldWideScience

Sample records for subpolar front moves

  1. A Tailward Moving Current Sheet Normal Magnetic Field Front Followed by an Earthward Moving Dipolarization Front

    Science.gov (United States)

    Hwang, K.-J.; Goldstein, M. L.; Moore, T. E.; Walsh, B. M.; Baishev, D. G.; Moiseyev, A. V.; Shevtsov, B. M.; Yumoto, K.

    2014-01-01

    A case study is presented using measurements from the Cluster spacecraft and ground-based magnetometers that show a substorm onset propagating from the inner to outer plasma sheet. On 3 October 2005, Cluster, traversing an ion-scale current sheet at the near-Earth plasma sheet, detected a sudden enhancement of Bz, which was immediately followed by a series of flux rope structures. Both the local Bz enhancement and flux ropes propagated tailward. Approximately 5 min later, another Bz enhancement, followed by a large density decrease, was observed to rapidly propagate earthward. Between the two Bz enhancements, a significant removal of magnetic flux occurred, possibly resulting from the tailward moving Bz enhancement and flux ropes. In our scenario, this flux removal caused the magnetotail to be globally stretched so that the thinnest sheet formed tailward of Cluster. The thinned current sheet facilitated magnetic reconnection that quickly evolved from plasma sheet to lobe and generated the later earthward moving dipolarization front (DF) followed by a reduction in density and entropy. Ground magnetograms located near the meridian of Cluster's magnetic foot points show two-step bay enhancements. The positive bay associated with the first Bz enhancement indicates that the substorm onset signatures propagated from the inner to the outer plasma sheet, consistent with the Cluster observation. The more intense bay features associated with the later DF are consistent with the earthward motion of the front. The event suggests that current disruption signatures that originated in the near-Earth current sheet propagated tailward, triggering or facilitating midtail reconnection, thereby preconditioning the magnetosphere for a later strong substorm enhancement.

  2. Moving boundary approximation for curved streamer ionization fronts: solvability analysis

    NARCIS (Netherlands)

    F. Brau (Fabian); B. Davidovitch; U. Ebert (Ute)

    2008-01-01

    textabstractThe minimal density model for negative streamer ionization fronts is investigated. An earlier moving boundary approximation for this model consisted of a “kinetic undercooling” type boundary condition in a Laplacian growth problem of Hele-Shaw type. Here we derive a curvature

  3. The ecosystem of the Mid-Atlantic Ridge at the sub-polar front and Charlie-Gibbs Fracture Zone; ECO-MAR project strategy and description of the sampling programme 2007-2010

    Science.gov (United States)

    Priede, Imants G.; Billett, David S. M.; Brierley, Andrew S.; Hoelzel, A. Rus; Inall, Mark; Miller, Peter I.; Cousins, Nicola J.; Shields, Mark A.; Fujii, Toyonobu

    2013-12-01

    The ECOMAR project investigated photosynthetically-supported life on the North Mid-Atlantic Ridge (MAR) between the Azores and Iceland focussing on the Charlie-Gibbs Fracture Zone area in the vicinity of the sub-polar front where the North Atlantic Current crosses the MAR. Repeat visits were made to four stations at 2500 m depth on the flanks of the MAR in the years 2007-2010; a pair of northern stations at 54°N in cold water north of the sub-polar front and southern stations at 49°N in warmer water influenced by eddies from the North Atlantic Current. At each station an instrumented mooring was deployed with current meters and sediment traps (100 and 1000 m above the sea floor) to sample downward flux of particulate matter. The patterns of water flow, fronts, primary production and export flux in the region were studied by a combination of remote sensing and in situ measurements. Sonar, tow nets and profilers sampled pelagic fauna over the MAR. Swath bathymetry surveys across the ridge revealed sediment-covered flat terraces parallel to the axis of the MAR with intervening steep rocky slopes. Otter trawls, megacores, baited traps and a suite of tools carried by the R.O.V. Isis including push cores, grabs and a suction device collected benthic fauna. Video and photo surveys were also conducted using the SHRIMP towed vehicle and the R.O.V. Isis. Additional surveying and sampling by landers and R.O.V. focussed on the summit of a seamount (48°44‧N, 28°10‧W) on the western crest of the MAR between the two southern stations.

  4. Wave fronts may move upstream in semiconductor superlattices

    Science.gov (United States)

    Carpio; Bonilla; Wacker; Scholl

    2000-05-01

    In weakly coupled, current biased, doped semiconductor superlattices, domain walls may move upstream against the flow of electrons. For appropriate doping values, a domain wall separating two electric-field domains moves downstream below a first critical current, it remains stationary between this value and a second critical current, and then moves upstream above. These conclusions are reached by using a comparison principle to analyze a discrete drift-diffusion model, and validated by numerical simulations. Possible experimental realizations are suggested.

  5. Detection of moving capillary front in porous rocks using X-ray and ultrasonic methods

    Directory of Open Access Journals (Sweden)

    Christian eDavid

    2015-07-01

    Full Text Available Several methods are compared for the detection of moving capillary fronts in spontaneous imbibition experiments where water invades dry porous rocks. These methods are: (i the continuous monitoring of the mass increase during imbibition, (ii the imaging of the water front motion using X-ray CT scanning, (iii the use of ultrasonic measurements allowing the detection of velocity, amplitude and spectral content of the propagating elastic waves, and (iv the combined use of X-ray CT scanning and ultrasonic monitoring. It is shown that the properties of capillary fronts depend on the heterogeneity of the rocks, and that the information derived from each method on the dynamics of capillary motion can be significantly different. One important result from the direct comparison of the moving capillary front position and the P wave attributes is that the wave amplitude is strongly impacted before the capillary front reaches the sensors, in contrast with the velocity change which is concomitant with the fluid front arrival in the sensors plane.

  6. Evaluation of Heat Losses Behind the Front of the Detonation Moving Along the Metallic Porous Surface

    Directory of Open Access Journals (Sweden)

    S. V. Golovastov

    2016-01-01

    Full Text Available The paper considers a computational technique of the heat flow from the hot products of detonation combustion into the porous coating and estimates the efficiency of the coating layer that results in slowing the flame front down with disregard the transverse displacement of the combustion products weight of a hydrogen-air mixture.Initial thermodynamic parameters of combustion products on the porous coating surface have been estimated. A drag (stagnation temperature of flow was determined.The statement of task was to calculate the heat flow into the long cylindrical metal fiber with radius of 15 μm. The reference values of heat capacity and heat diffusivity were used to estimate a thermal diffusivity in a wide range of temperatures. An approximation of the parameters is given for a wide range of temperatures.The calculation algorithm using an explicit four-point scheme is presented. The convergence and accuracy of the results were confirmed. The theoretical estimation using cylindrical Bessel functions was made to prove the accuracy of the results.Total heat loss was estimated using the photos of moving detonation front and hot combustion gases.Comparison of the total heat loss and the amount of energy absorbed by a single fiber allowed us to find that the porous coating thickness, resulting in attenuation of detonation wave, is efficient.

  7. The Telecom Lab is moving to the Building 2, in front of the Main Building

    CERN Multimedia

    IT Department

    2011-01-01

      As of 28 September 2011, the Telecom Lab will move to the Building 2/1-046. Please note that the Telecom Lab desk will be closed on 28 of September due to the move. However, for all urgent matters, please contact the Telecom Lab by mail or by phone. The Telecom Lab is the central point for all support questions regarding CERN mobile phone services (provision of SIM cards, requests for modifications of subscriptions, diagnostics for mobile phone problems, etc.). The opening hours as well as the contact details for the Telecom Lab remain unchanged. New location:                Building 2/1-046 Opening hours:              From Monday to Friday, from 8 a.m. to 6 p.m. Phone number:      ...

  8. Analysis and observation of moving domain fronts in a ring of coupled electronic self-oscillators

    Science.gov (United States)

    English, L. Q.; Zampetaki, A.; Kevrekidis, P. G.; Skowronski, K.; Fritz, C. B.; Abdoulkary, Saidou

    2017-10-01

    In this work, we consider a ring of coupled electronic (Wien-bridge) oscillators from a perspective combining modeling, simulation, and experimental observation. Following up on earlier work characterizing the pairwise interaction of Wien-bridge oscillators by Kuramoto-Sakaguchi phase dynamics, we develop a lattice model for a chain thereof, featuring an exponentially decaying spatial kernel. We find that for certain values of the Sakaguchi parameter α, states of traveling phase-domain fronts involving the coexistence of two clearly separated regions of distinct dynamical behavior, can establish themselves in the ring lattice. Experiments and simulations show that stationary coexistence domains of synchronization only manifest themselves with the introduction of a local impurity; here an incoherent cluster of oscillators can arise reminiscent of the chimera states in a range of systems with homogeneous oscillators and suitable nonlocal interactions between them.

  9. Subpolar North Atlantic glider observations for OSNAP

    Science.gov (United States)

    Zhou, C.; Hodges, B.; Bower, A. S.; Yang, J.; Lin, X.

    2016-02-01

    OSNAP is an international program designed to provide a continuous record of the full-water-column, trans-basin fluxes of heat, mass, and freshwater in the subpolar North Atlantic. The observational efforts of this program are focused largely along lines connecting Labrador to Greenland, and Greenland to Scotland. The OSNAP experimental plan includes continuous sampling by Slocum G2 gliders along the latter (easternmost) of these two sections, specifically across the northeastward-flowing North Atlantic Current in the Iceland Basin. The glider observations, a collaboration between the Ocean University of China and Woods Hole Oceanographic Institution, provide higher spatial resolution of water properties than is possible from moorings alone. These observations commenced in June 2015 with a mission to fly back and forth along a section between two OSNAP moorings, profiling from the surface to 1000-m depth. As of September 2015, five sections (including over 240 profiles) have been recorded. As expected, the data indicates energetic intraseasonal variability at smaller scales than can be captured by the OSNAP mooring array. We are investigating how this variability may impact calculated fluxes of heat, mass, and freshwater. The glider repeatedly crossed a cyclonic eddy between the two moorings, enabling study of fine thermohaline structure during the development and dissipation of mesoscale eddies in the subpolar North Atlantic. With additional sensors measuring fluorescence, dissolved oxygen, nitrate, and multispectral light, the dataset also has the potential to significantly advance our understanding of the biogeochemical processes of mesoscale and submesoscale eddies in the subpolar North Atlantic.

  10. Eulerian Oil Spills Model Using Finite-Volume Method with Moving Boundary and Wet-Dry Fronts

    Directory of Open Access Journals (Sweden)

    Ehsan Sarhadi Zadeh

    2012-01-01

    Full Text Available The world production of crude oil is about 3 billion tons per year. The overall objective of the model in present study is supporting the decision makers in planning and conducting preventive and emergency interventions. The conservative equation for the slick dynamics was derived from layer-averaged Navier-Stokes (LNS equations, averaged over the slick thickness. Eulerian approach is applied across the model, based on nonlinear shallow water Reynolds-averaged Navier-Stokes (RANS equations. Depth-integrated standard k-ε turbulence schemes have been included in the model. Wetting and drying fronts of intertidal zone and moving boundary are treated within the numerical model. A highly accurate algorithm based on a fourth-degree accurate shape function has been used through an alternating-direction implicit (ADI scheme which separates the operators into locally one-dimensional (LOD components. The solution has been achieved by the application of KPENTA algorithm for the set of the flow equations which constitutes a pentadiagonal matrix. Hydrodynamic model was validated for a channel with a sudden expansion in width. For validation of oil spill model, predicted results are compared with experimental data from a physical modeling of oil spill in a laboratory wave basin under controlled conditions.

  11. Rodent communities in the sub-polar Ural mountains

    Directory of Open Access Journals (Sweden)

    Berdyugin, K. I.

    2004-12-01

    Full Text Available Distribution of the rodent communities in the Sub-polar Urals is analysed. This part of the range, between 64° and 66°N, includes the highest peaks, is very scarcely settled and has been rarely studied. However, the area is interesting for biogeography, being a border zone separating European and Siberian lowland faunas. Comparison of results with those from expeditions undertaken in 1927 and in 1972, allows to evaluate changing trends in the local rodent communities, and to relate these trends to changes in the environmental conditions. The results help to emphasize the barrier role played by Sub-polar Urals for the species of rodents inhabiting both sides of the range, and also show the shifting of southern rodent forms northwards, or the moving upwards of other lowland species. This could be seen as an additional evidence of current climate warming trends.

    [fr]
    On analyse la répartition des communautés de rongeurs dans les Durais Subpolaires, une section de la chaîne comprise entre les 64° et les 66° de latitude N. Cette partie est très peu peuplée, elle possède les pics les plus hauts de la chaîne et a été rarement étudiée. Il s'agit d'une région intéressante, car c'est la frontière entre les plaines européennes et les plaines orientales de la Sibérie. En comparant les observations effectuées en 1927 et en 1972 avec celles des dernières années, on peut voir les tendances de changement des groupements de rongeurs de la région, et les interpréter en fonction des changements dans l'environnement. Les résultats permettent de mieux comprendre le rôle de barrière qui jouent les Durais Subpolaires pour les espèces de rongeurs situées d'un coté et d'autre de la chaîne. Aussi, ils permettent de verifier le déplacement vers le nord deformes méridionales et l'élévation en altitude d'autres, ce qui pourrait être vu comme une preuve additionnelle de la tendance au réchauffement global.
    [es]
    Se

  12. Government of the Republic of the Philippines - Moro Islamic Liberation Front Peace Talks: A Bold Move to Counter Terrorism

    National Research Council Canada - National Science Library

    Amarille, Roland C

    2006-01-01

    .... The government of the Republic of the Philippines (GRP) and the Moro Islamic Liberation Front (MILF) are presently engaged in peace talks to thresh out their related concerns and resolve their problems...

  13. Influence of the Atlantic subpolar gyre on the thermohaline circulation.

    Science.gov (United States)

    Hátún, Hjálmar; Sandø, Anne Britt; Drange, Helge; Hansen, Bogi; Valdimarsson, Hedinn

    2005-09-16

    During the past decade, record-high salinities have been observed in the Atlantic Inflow to the Nordic Seas and the Arctic Ocean, which feeds the North Atlantic thermohaline circulation (THC). This may counteract the observed long-term increase in freshwater supply to the area and tend to stabilize the North Atlantic THC. Here we show that the salinity of the Atlantic Inflow is tightly linked to the dynamics of the North Atlantic subpolar gyre circulation. Therefore, when assessing the future of the North Atlantic THC, it is essential that the dynamics of the subpolar gyre and its influence on the salinity are taken into account.

  14. Limited production of sulfate and nitrate on front-associated dust storm particles moving from desert to distant populated areas in northwestern China

    Directory of Open Access Journals (Sweden)

    F. Wu

    2017-12-01

    production of nitrate and sulfate on dust particles following cold fronts is likely limited when the particles move from the desert to populated areas within the continent. For an accurate quantification of sulfate and nitrate formed on long-distance-transported desert dust particles at downwind populated areas in eastern China, dust collection efforts are indispensable to minimize any possible influence by locally emitted particles or at least to ensure that the samples are collected after dust arrival.

  15. Phytoplankton bloom and subpolar gyre induced dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Hátún, Hjálmar; Counillion, Francois

    blooms are expected in years of a strong subpolar gyre, i.e. strong atmospheric forcing, and cold and low saline conditions. We apply novel phenology algorithms to satellite ocean colour data, and analyse the outcome together with the subpolar gyre index. We find that the relationship between the bloom...

  16. Nonspecific organic compounds in peat soils of the Subpolar Urals

    Science.gov (United States)

    Nizovtsev, N. A.; Kholodov, V. A.; Ivanov, V. A.; Farkhodov, Yu. R.; Dymov, A. A.

    2017-09-01

    Specific features of organic matter, molecular composition and distribution of oxygen-containing nonspecific organic compounds (fatty acids, long-chain aliphatic alcohols, and ketones) were revealed in two peat soils on slopes of the Subpolar Urals: the eutrophic peat soil of the spring mire (Hemic Histosols) and the peat soil of a slope mire (Fibric Histosols). Compounds that can serve as molecular markers for some evolutionary stages of peats were determined for this area. Based on the data obtained, the most probable causes of differences in the composition of organic compounds in the peats studied were found to be the following: environmental conditions, water and mineral regime of bog, and differences in the composition of peat-forming plants.

  17. The Dynamics of the North Atlantic Subpolar Gyre Introduces Predictability to the Breeding Success of Kittiwakes

    Directory of Open Access Journals (Sweden)

    Hjálmar Hátún

    2017-05-01

    Full Text Available Since the open-ocean subpolar Atlantic is amongst the most predictable regions in the world, our results hold promise for predicting the general production to seabird populations over a large geographical region adjacent to the northern North Atlantic and the Arctic Mediterranean. Colonies of black-legged kittiwakes Rissa tridactyla in the North Atlantic have declined markedly since the mid-1990s, partly due to repeatedly failing breeding seasons. We show a close link between the breeding success of a kittiwake colony in the Faroe Islands and the subpolar gyre index. Successful breeding follows winters with an expanded subpolar gyre and, by inference, increased zooplankton abundances southwest of Iceland. The environmental conditions in the northwestern Atlantic during the non-breeding and pre-breeding seasons might therefore be important. Furthermore, the subpolar gyre dynamics might influence the local food abundance on the Faroe shelf during the breeding season.

  18. EEG CHARACTERISTICS AND THYROID PROFILE RATIO IN ADOLESCENTS OF SUBPOLAR AND POLAR EUROPEAN NORTH AREAS

    Directory of Open Access Journals (Sweden)

    D. B. Demin

    2013-01-01

    Full Text Available Features of brain bioelectric activity and thyroid system in adolescents living in Subpolar andPolar regionsof the North are considered. Hyperactivity of subcortical diencephalic brain structures in adolescents of the Polar region is revealed. Adolescents of Subpolar region have more intensive age optimization of neurodynamic processes. There are noted latitude distinctions of thyroid hormones role for age formation of brain bioelectric activity in adolescents.

  19. Unexpected winter phytoplankton blooms in the North Atlantic subpolar gyre

    Science.gov (United States)

    Lacour, L.; Ardyna, M.; Stec, K. F.; Claustre, H.; Prieur, L.; Poteau, A.; D'Alcala, M. Ribera; Iudicone, D.

    2017-11-01

    In mid- and high-latitude oceans, winter surface cooling and strong winds drive turbulent mixing that carries phytoplankton to depths of several hundred metres, well below the sunlit layer. This downward mixing, in combination with low solar radiation, drastically limits phytoplankton growth during the winter, especially that of the diatoms and other species that are involved in seeding the spring bloom. Here we present observational evidence for widespread winter phytoplankton blooms in a large part of the North Atlantic subpolar gyre from autonomous profiling floats equipped with biogeochemical sensors. These blooms were triggered by intermittent restratification of the mixed layer when mixed-layer eddies led to a horizontal transport of lighter water over denser layers. Combining a bio-optical index with complementary chemotaxonomic and modelling approaches, we show that these restratification events increase phytoplankton residence time in the sunlight zone, resulting in greater light interception and the emergence of winter blooms. Restratification also caused a phytoplankton community shift from pico- and nanophytoplankton to phototrophic diatoms. We conclude that transient winter blooms can maintain active diatom populations throughout the winter months, directly seeding the spring bloom and potentially making a significant contribution to over-winter carbon export.

  20. Fronts, fish, and predators

    Science.gov (United States)

    Belkin, Igor M.; Hunt, George L.; Hazen, Elliott L.; Zamon, Jeannette E.; Schick, Robert S.; Prieto, Rui; Brodziak, Jon; Teo, Steven L. H.; Thorne, Lesley; Bailey, Helen; Itoh, Sachihiko; Munk, Peter; Musyl, Michael K.; Willis, Jay K.; Zhang, Wuchang

    2014-09-01

    Ocean fronts play a key role in marine ecosystems. Fronts shape oceanic landscapes and affect every trophic level across a wide range of spatio-temporal scales, from meters to thousands of kilometers, and from days to millions of years. At some fronts, there is an elevated rate of primary production, whereas at others, plankton is aggregated by advection and by the behavior of organisms moving against gradients in temperature, salinity, light irradiance, hydrostatic pressure and other physico-chemical and biological factors. Lower trophic level organisms - phytoplankton and zooplankton - that are aggregated in sufficient densities, attract organisms from higher trophic levels, from planktivorous schooling fish to squid, large piscivorous fish, seabirds and marine mammals. Many species have critical portions of their life stages or behaviors closely associated with fronts, including spawning, feeding, ontogenetic development, migrations, and other activities cued to frontal dynamics. At different life stages, an individual species or population might be linked to different fronts. The nature and strength of associations between fronts and biota depend on numerous factors such as the physical nature and spatio-temporal scales of the front and the species and their life stages in question. In other words, fronts support many different niches and micro/macro-habitats over a wide range of spatial and temporal scales.

  1. Dynamics of decadal variability in the Atlantic subpolar gyre: a stochastically forced oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Born, Andreas [University of Bern, Climate and Environmental Physics, Physics Institute, Bern (Switzerland); Oeschger Centre for Climate Change Research, Bern (Switzerland); Bjerknes Centre for Climate Research, Bergen (Norway); University of Bergen, Geophysical Institute, Bergen (Norway); Mignot, Juliette [IPSL/UPMC/CNRS/IRD/MNHN, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, Paris (France)

    2012-07-15

    Internal variability of the Atlantic subpolar gyre is investigated in a 600 years control simulation of a comprehensive coupled climate model. The subpolar gyre shows irregular oscillations of decadal time scale with most spectral power between 15 and 20 years. Positive and negative feedback mechanisms act successively on the circulation leading to an internal oscillation. This involves periodically enhanced deep convection in the subpolar gyre center and intermittently enhanced air-sea thermal coupling. As a result, anomalies of the large-scale atmospheric circulation can be transferred to the ocean on the ocean's intrinsic time scale, exciting the oscillator stochastically. A detailed understanding of oscillatory mechanisms of the ocean and their sensitivity to atmospheric forcing holds considerable potential for decadal predictions as well as for the interpretation of proxy data records. (orig.)

  2. The Sub-Polar Gyre Index - a community data set for application in fisheries and environment research

    DEFF Research Database (Denmark)

    Berx, Barbara; Payne, Mark

    2017-01-01

    Scientific interest in the sub-polar gyre of the North Atlantic Ocean has increased in recent years. The sub-polar gyre has contracted and weakened, and changes in circulation pathways have been linked to changes in marine ecosystem productivity. To aid fisheries and environmental scientists, we...

  3. Paleomagnetism of Permian rocks of the Subpolar Urals, Kozhim River: To the history of evolution of the thrust structures in the Subpolar Urals

    Science.gov (United States)

    Iosifidi, A. G.; Popov, V. V.

    2017-09-01

    The collections of Permian rocks from sections of the Kozhim River (Asselian, Kungurian, and Ufimian stages) and the Kama River (Ufimian and Kazanian stages) are studied. The paleomagnetic directions determined on the studied structures closely agree with the existing data for the Subpolar Urals and Russian Platform (RP). In the Middle Permian red clays of the Kama River region, the paleomagnetic pole N/n = 28/51, Φ = 47° N, Λ = 168° E, dp = 3°, and dm = 5° is obtained. The analysis of the existing paleomagnetic determinations for the Early and Middle Permian of the Russian and Siberian platforms and Kazakhstan blocks (KBs) is carried out. For the Subpolar Ural sections, the estimates are obtained for the local rotations during the collision of the Uralian structures with the Russian and Siberian platforms and KBs. The amplitudes of the horizontal displacements of the studied structures are, on average, 170 ± 15 km per Middle Permian. The scenario describing the evolution of the horizontal rotations of the structures of Subpolar Urals is suggested.

  4. Propagating reaction fronts in moving fluids

    OpenAIRE

    Vilela Proaño, Pablo Martin

    2015-01-01

    La presente tesis tuvo como objetivo estudiar frentes de reacción modelados mediante la ecuación de Kuramoto-Sivashinsky sujetos a diferentes tipos de movimiento de fluido: flujo externo de Poiseuille, el cual es contrastado con el flujo de Couette, y flujo convectivo debido a la inestabilidad de Rayleigh-Taylor. En el primer caso, los frentes se propagan a favor o en contra de un flujo estacionario bidimensional entre dos placas paralelas que se conoce como flujo de Poiseuille. Para pequeñas...

  5. Front cover

    Directory of Open Access Journals (Sweden)

    Prof.Dr. Hasan KÜÇÜKBAY

    2017-06-01

    Full Text Available This is the front cover of JOTCSA 4(2, which contains numerous fruitful information. Kindly read the contents and if you need to ask questions, contact the managing editor (Dr. Akkurt at jotcsa@turchemsoc.org or the chief editor (Prof. Dr. Küçükbay. Let us see each other in the next issue...

  6. Evolution of subpolar North Atlantic surface circulation since the early Holocene inferred from planktic foraminifera faunal and stable isotope records

    Science.gov (United States)

    Staines-Urías, Francisca; Kuijpers, Antoon; Korte, Christoph

    2013-09-01

    Past changes in the surface flow regime of two main eastern North Atlantic warm water pathways toward the Nordic seas were reconstructed based on faunal analyses in combination with carbon and oxygen stable isotope measurements in planktic foraminifera. The investigated sites, in the surroundings of the Faroe Islands, are located in the transitional area where surface waters of subpolar and subtropical origin mix before entering the Arctic Mediterranean. In these areas, large-amplitude millennial variability in the characteristics of the upper-water column appears modulated by changes in the intensity of the Subpolar Gyre circulation. From 7.8 to 6 ka BP, faunal records indicate a deep mixed-layer which, in conjunction with lighter δ18O values, suggest that the inflowing Atlantic waters were dominated by a relatively cooler and fresher water mass, reflecting a strengthening of the Subpolar Gyre under conditions of enhanced positive NAO-like forcing and reduced meltwater input. A shift in the hydrographic conditions occurred during the Mid-Holocene (centered at 5 ka BP). At this time, increasing upper water column stratification and the incipient differentiation of the stable isotopic signal of the Iceland-Faroe and Faroe-Shetland surface water masses, suggest increasing influx of warmer, more saline surface waters from the Subtropical Gyre, as Subpolar Gyre circulation weakened. The mid-Holocene decline in Subpolar Gyre strength is presumably related to a shift toward a low state of the NAO-like forcing associated with decreased solar irradiance. Later in the Holocene, from 4 ka BP to present, the increased frequency and reduced amplitude of the surface hydrographic changes reflect corresponding fluctuations in Subpolar Gyre circulation. These high frequency oscillations in Subpolar Gyre strength suggest increased surface circulation sensitivity to moderate freshwater fluxes to the Labrador-Irminger Sea basin, highlighting the importance of the salinity balance in

  7. Mountain wave-induced variations of ozone and total nitrogen dioxide contents over the Subpolar Urals

    Science.gov (United States)

    Kozhevnikov, V. N.; Elansky, N. F.; Moiseenko, K. B.

    2017-08-01

    Wavy spatial variations in the contents of trace gases are identified using plane measurements of O3 concentrations in the medium troposphere and the total content (TC) of NO2 in the atmospheric column from flights above the Subpolar Urals in April 1984. The results of model calculations allow us to relate these variations to mesoscale atmospheric disturbances above the mountains, which are caused by the influence of dynamic relief on the leaked-in flow.

  8. Moving Hands, Moving Entities

    Science.gov (United States)

    Setti, Annalisa; Borghi, Anna M.; Tessari, Alessia

    2009-01-01

    In this study we investigated with a priming paradigm whether uni and bimanual actions presented as primes differently affected language processing. Animals' (self-moving entities) and plants' (not self-moving entities) names were used as targets. As prime we used grasping hands, presented both as static images and videos. The results showed an…

  9. Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

    Science.gov (United States)

    Hunt, George L.; Drinkwater, Kenneth F.; Arrigo, Kevin; Berge, Jørgen; Daly, Kendra L.; Danielson, Seth; Daase, Malin; Hop, Haakon; Isla, Enrique; Karnovsky, Nina; Laidre, Kristin; Mueter, Franz J.; Murphy, Eugene J.; Renaud, Paul E.; Smith, Walker O.; Trathan, Philip; Turner, John; Wolf-Gladrow, Dieter

    2016-12-01

    We compare and contrast the ecological impacts of atmospheric and oceanic circulation patterns on polar and sub-polar marine ecosystems. Circulation patterns differ strikingly between the north and south. Meridional circulation in the north provides connections between the sub-Arctic and Arctic despite the presence of encircling continental landmasses, whereas annular circulation patterns in the south tend to isolate Antarctic surface waters from those in the north. These differences influence fundamental aspects of the polar ecosystems from the amount, thickness and duration of sea ice, to the types of organisms, and the ecology of zooplankton, fish, seabirds and marine mammals. Meridional flows in both the North Pacific and the North Atlantic oceans transport heat, nutrients, and plankton northward into the Chukchi Sea, the Barents Sea, and the seas off the west coast of Greenland. In the North Atlantic, the advected heat warms the waters of the southern Barents Sea and, with advected nutrients and plankton, supports immense biomasses of fish, seabirds and marine mammals. On the Pacific side of the Arctic, cold waters flowing northward across the northern Bering and Chukchi seas during winter and spring limit the ability of boreal fish species to take advantage of high seasonal production there. Southward flow of cold Arctic waters into sub-Arctic regions of the North Atlantic occurs mainly through Fram Strait with less through the Barents Sea and the Canadian Archipelago. In the Pacific, the transport of Arctic waters and plankton southward through Bering Strait is minimal. In the Southern Ocean, the Antarctic Circumpolar Current and its associated fronts are barriers to the southward dispersal of plankton and pelagic fishes from sub-Antarctic waters, with the consequent evolution of Antarctic zooplankton and fish species largely occurring in isolation from those to the north. The Antarctic Circumpolar Current also disperses biota throughout the Southern Ocean

  10. Stationary flow near fronts

    Directory of Open Access Journals (Sweden)

    Reinhold Steinacker

    2016-12-01

    Full Text Available In 1906, the Austrian scientist Max Margules published a paper on temperature stratification in resting and non-accelerated moving air. The paper derives conditions for stationary slopes of air mass boundaries and was an important forerunner of frontal theories. Its formulation of relations between changes in density and geostrophic wind across the front is basically a discrete version of the thermal wind balance equation. The paper was highly influential and is still being cited to the present day. This paper accompanies an English translation of Margules’ seminal paper. We conclude here our “Classic Papers” series of the Meteorologische Zeitschrift.

  11. Let's Keep Moving!

    Science.gov (United States)

    Obama, Michelle

    2012-01-01

    First Lady Michelle Obama lauds educators for following the lead of her Let's Move! program and taking action to curtail childhood obesity. The battle to make children healthier is being waged on a number of fronts by food companies, restaurants and schools. Progress has been made, she says, but more is needed.

  12. The role of subpolar atmosphere-ice-ocean interactions in D-O cycles

    Science.gov (United States)

    Li, Camille; Born, Andreas

    2017-04-01

    Sea ice has long been thought to play an important role in D-O cycles because of its strong influence on regional temperature and its ability to grow and melt rapidly in response to relatively weak forcings. One recent idea based on modelling experiments is that D-O-related sea ice displacements are part of an unforced, coupled oscillation of the North Atlantic atmosphere-ice-ocean system. Here, we present an overview of key components of this system, as well as observational and modelling results addressing how they function in today's climate, and how glacial climate conditions might alter their functioning to allow D-O cycles to occur. Of specific interest are the necessary changes in the subpolar gyre, the thermohaline structure and stratification of the Nordic Seas, the existence of an Arctic-like cold halocline at subpolar latitudes, and the accessibility of the subsurface ocean heat reservoir to the atmosphere. Broader consequences for the Atlantic thermohaline circulation and Southern Hemisphere climate signals will be discussed.

  13. Subpolar addition of new cell wall is directed by DivIVA in mycobacteria

    Science.gov (United States)

    Meniche, Xavier; Otten, Renee; Siegrist, M. Sloan; Baer, Christina E.; Murphy, Kenan C.; Bertozzi, Carolyn R.; Sassetti, Christopher M.

    2014-01-01

    Mycobacteria are surrounded by a complex multilayered envelope and elongate at the poles. The principles that organize the coordinated addition of chemically diverse cell wall layers during polar extension remain unclear. We show that enzymes mediating the terminal cytosolic steps of peptidoglycan, arabinogalactan, and mycolic acid synthesis colocalize at sites of cell growth or division. The tropomyosin-like protein, DivIVA, is targeted to the negative curvature of the pole, is enriched at the growing end, and determines cell shape from this site. In contrast, cell wall synthetic complexes are concentrated at a distinct subpolar location. When viewed at subdiffraction resolution, new peptidoglycan is deposited at this subpolar site, and inert cell wall covers the DivIVA-marked tip. The differentiation between polar tip and cell wall synthetic complexes is also apparent at the biochemical level. Enzymes that generate mycolate precursors interact with DivIVA, but the final condensation of mycolic acids occurs in a distinct protein complex at the site of nascent cell wall addition. We propose an ultrastructural model of mycobacterial polar growth where new cell wall is added in an annular zone below the cell tip. This model may be broadly applicable to other bacterial and fungal organisms that grow via polar extension. PMID:25049412

  14. Evolution of subpolar North Atlantic surface circulation since the early Holocene inferred from planktic foraminifera faunal and stable isotope records

    DEFF Research Database (Denmark)

    Staines-Urias, Francisca; Kuijpers, Antoon; Korte, Christoph

    2013-01-01

    of the Faroe Islands, are located in the transitional area where surface waters of subpolar and subtropical origin mix before entering the Arctic Mediterranean. In these areas, large-amplitude millennial variability in the characteristics of the upper-water column appears modulated by changes in the intensity...

  15. Front Propagation in Stochastic Neural Fields

    KAUST Repository

    Bressloff, Paul C.

    2012-01-01

    We analyze the effects of extrinsic multiplicative noise on front propagation in a scalar neural field with excitatory connections. Using a separation of time scales, we represent the fluctuating front in terms of a diffusive-like displacement (wandering) of the front from its uniformly translating position at long time scales, and fluctuations in the front profile around its instantaneous position at short time scales. One major result of our analysis is a comparison between freely propagating fronts and fronts locked to an externally moving stimulus. We show that the latter are much more robust to noise, since the stochastic wandering of the mean front profile is described by an Ornstein-Uhlenbeck process rather than a Wiener process, so that the variance in front position saturates in the long time limit rather than increasing linearly with time. Finally, we consider a stochastic neural field that supports a pulled front in the deterministic limit, and show that the wandering of such a front is now subdiffusive. © 2012 Society for Industrial and Applied Mathematics.

  16. Little Ice Age wintertime climate cooling linked to N-Atlantic subpolar gyre warming

    Science.gov (United States)

    Kuijpers, Antoon; Seidenkrantz, Marit-Solveig; Sicre, Marie-Alexandrine; Andresen, Camilla S.; Staines-Urías, Francisca

    2015-04-01

    Traditionally, the Little Ice Age (LIA) in the North Atlantic is believed to have been marked by negative Sea Surface Temperature (SST) anomalies. In apparent contrast, we present evidence from sediment core records from the N-Atlantic Subpolar Gyre showing prevalence of warm SST conditions. Our proxy data include both alkenone-based SST reconstructions and results from faunal and geochemical foraminiferal studies. Subpolar Gyre SST warming after the Medieval Climate Anomaly is observed in the Labrador Current close to the Gulf Stream boundary off Newfoundland, which agrees with previously reported increased influence of warmer, Gulf Stream-derived Slope Water off southern Newfoundland(1). Our core records from the West- and East Greenland Current realm off southern Greenland, as well as sites in Faroese waters, correspondingly indicate increased influence of warm, saline North Atlantic / Irminger Current waters. Other recently published studies also report LIA SST warming in the northern subpolar North Atlantic(2) as well as increased heat transport into the Arctic via the West Spitsbergen Current(3). Growing evidence indicates that positive SST anomalies in the North Atlantic Ocean can promote negative NAO conditions, thus be linked with cold wintertime conditions in Northwestern Europe. A published modeling study using ensemble simulations with an atmospheric GCM forced with reconstructed SST data for the period 1871-1999 shows weakening of the westerly winds around 60o N with SST anomalies that have the same sign across the North Atlantic(4). Six other climate models show that with some years of delay, an intensified Atlantic Meridional Overturning Circulation leads to a weak negative North Atlantic Oscillation (NAO) phase during winter(5). Furthermore, it was recently found that the stratosphere is a key element of extra-tropical response to ocean variability. Observational analysis and atmospheric model experiments indicate that large-scale Atlantic Ocean

  17. Seasonal and Interannual Variability of Calcite in the Sub-Polar North Atlantic

    Science.gov (United States)

    Signorini, S. R.; McClain, C. R.

    2008-12-01

    Coccolithophores, among which Emiliania huxleyi (E. huxleyi) is the most abundant and widespread species, are considered to be the most productive calcifying organisms on Earth. They inhabit the surface layer (MLD ~20m) in highly stratified waters where light intensity is high. E. huxleyi often forms massive blooms in temperate and sub-polar oceans. Coupling of the coccolithophore organic carbon and carbonate pumps interact to consume (photosynthesis) and produce (calcification) CO2. The so-called Rain Ratio, defined as the ratio of particulate inorganic carbon (PIC) to particulate organic carbon (POC) in exported biogenic matter, determines the relative strength of the two biological carbon pumps and influences the flux of CO2 across the surface ocean - atmosphere interface. Here we use a combination of satellite ocean color algorithms and numerical model products to describe the seasonal and interannual variability of PIC in the sub-polar North Atlantic. Phytoplankton and calcite production have strong spatial variability. Nutrient supply, biomass and calcite concentrations are modulated by light and MLD seasonal cycle. The size, intensity, and location of coccolithophore blooms vary from year to year, but the peak bloom is always in June in the Central Basin (45°W - 10°W, 50°N - 65°N) and August in the Barents Sea. Calcification rates range from 5% to 27% of net primary production. The Barents Sea PIC production is about twice that of the Central Basin. Predicted freshening and warming of polar seas may increase stratification, thus favoring an increase in coccolithophore bloom development. However, although significant interannual changes were identified, there were no obvious trends in the satellite-derived PIC concentrations over the past 10 years.

  18. Time dependency of the prediction skill for the North Atlantic subpolar gyre in initialized decadal hindcasts

    Science.gov (United States)

    Brune, Sebastian; Düsterhus, André; Pohlmann, Holger; Müller, Wolfgang A.; Baehr, Johanna

    2017-11-01

    We analyze the time dependency of decadal hindcast skill in the North Atlantic subpolar gyre within the time period 1961-2013. We compare anomaly correlation coefficients and temporal interquartile ranges of total upper ocean heat content and sea surface temperature for three differently initialized sets of hindcast simulations with the global coupled model MPI-ESM. All initializations use weakly coupled assimilation with the same full value nudging in the atmospheric component and different assimilation techniques for oceanic temperature and salinity: (1) ensemble Kalman filter assimilating EN4 observations and HadISST data, (2) nudging of anomalies to ORAS4 reanalysis, (3) nudging of full values to ORAS4 reanalysis. We find that hindcast skill depends strongly on the evaluation time period, with higher hindcast skill during strong multiyear trends, especially during the warming in the 1990s and lower hindcast skill in the absence of such trends. Differences between the prediction systems are more pronounced when investigating any 20-year subperiod within the entire hindcast period. In the ensemble Kalman filter initialized hindcasts, we find significant correlation skill for up to 5-8 lead years, albeit along with an overestimation of the temporal interquartile range. In the hindcasts initialized by anomaly nudging, significant correlation skill for lead years greater than two is only found in the 1980s and 1990s. In the hindcasts initialized by full value nudging, correlation skill is consistently lower than in the hindcasts initialized by anomaly nudging in the first lead years with re-emerging skill thereafter. The Atlantic meridional overturning circulation reacts on the density changes introduced by oceanic nudging, this limits the predictability in the subpolar gyre in the first lead years. Overall, we find that a model-consistent assimilation technique can improve hindcast skill. Further, the evaluation of 20 year subperiods within the full hindcast period

  19. Subpolar Atlantic cooling and North American east coast warming linked to AMOC slowdown

    Science.gov (United States)

    Rahmstorf, Stefan; Caesar, Levke; Feulner, Georg; Saba, Vincent

    2017-04-01

    Reconstructing the history of the Atlantic Meridional Overturning Circulation (AMOC) is difficult due to the limited availability of data. One approach has been to use instrumental and proxy data for sea surface temperature (SST), taking multi-decadal and longer SST variations in the subpolar gyre region as indicator for AMOC changes [Rahmstorf et al., 2015]. Recent high-resolution global climate model results [Saba et al., 2016] as well as dynamical theory and conceptual modelling [Zhang and Vallis, 2007] suggest that an AMOC weakening will not only cool the subpolar Atlantic but simultaneously warm the Northwest Atlantic between Cape Hatteras and Nova Scotia, thus providing a characteristic SST pattern associated with AMOC variations. We analyse sea surface temperature (SST) observations from this region together with high-resolution climate model simulations to better understand the linkages of SST variations to AMOC variability and to provide further evidence for an ongoing AMOC slowdown. References Rahmstorf, S., J. E. Box, G. Feulner, M. E. Mann, A. Robinson, S. Rutherford, and E. J. Schaffernicht (2015), Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation, Nature Climate Change, 5(5), 475-480, doi: 10.1038/nclimate2554. Saba, V. S., et al. (2016), Enhanced warming of the Northwest Atlantic Ocean under climate change, Journal of Geophysical Research-Oceans, 121(1), 118-132, doi: 10.1002/2015JC011346. Zhang, R., and G. K. Vallis (2007), The Role of Bottom Vortex Stretching on the Path of the North Atlantic Western Boundary Current and on the Northern Recirculation Gyre, Journal of Physical Oceanography, 37(8), 2053-2080, doi: 10.1175/jpo3102.1.

  20. Microscopic Mechanisms for Propagating Deformation Fronts

    Science.gov (United States)

    Franklin, Scott

    2001-03-01

    Alloys often deform through the propagation of slowly moving ( cm/s) fronts separating strained and unstrained regions. Theories for these Portevin-Le Chatelier (PLC) fronts are mostly on the macroscopic level, dealing with strains instead of dislocation populations. In these models diffusion, a possible mechanism for propagation, fails to produce front behavior consistent with experiments. Previous work* used a nonlocal strain-rate to successfully reproduce many different aspects of experimentally observed fronts. Ananthakrishna has proposed a set of equations that describe the evolution of different dislocation populations. These equations reproduce the temporal behavior of the PLC effect, serrated stress-strain curves accompanying smooth loading. It is natural to ask whether diffusive or other spatial coupling terms added to this model result in fronts. I will discuss simulations of these equations with added spatial terms and attempt to compare the results with experiments. *S. Franklin, F. Mertens, and M. Marder, Phys. Rev. E V. 62 (2000)

  1. Autowaves in moving excitable media

    Directory of Open Access Journals (Sweden)

    V.A.Davydov

    2004-01-01

    Full Text Available Within the framework of kinematic theory of autowaves we suggest a method for analytic description of stationary autowave structures appearing at the boundary between the moving and fixed excitable media. The front breakdown phenomenon is predicted for such structures. Autowave refraction and, particulary, one-side "total reflection" at the boundary is considered. The obtained analytical results are confirmed by computer simulations. Prospects of the proposed method for further studies of autowave dynamics in the moving excitable media are discussed.

  2. Assessing variability in the size and strength of the North Atlantic subpolar gyre

    Science.gov (United States)

    Foukal, Nicholas P.; Lozier, M. Susan

    2017-08-01

    Recent studies on the size and strength of the North Atlantic subpolar gyre (SPG) offer contrasting assessments of the gyre's temporal variability: studies that use empirical orthogonal function (EOF) analyses of satellite sea-surface height (SSH) report a rapid decline in SPG size and strength since 1992 (˜20% per decade), while concurrent in situ observations report either no trend or a slight decline. Here we investigate this discrepancy by analyzing the size and strength of the SPG with satellite SSH from 1993 to 2015 with two separate methods: indirectly via EOF analysis and more directly through measurements of the gyre center and boundary. We define the boundary of the gyre as the largest closed contour of SSH, the center as the minimum SSH, and the strength as the difference between the SSH at the boundary and the center. We identify a linear decline over the study period in the SPG strength (5.1% per decade), but find no statistically significant trend in the SPG area. The trend in the gyre strength is weaker than the EOF-based trend and is most likely below the level of detection of the in situ measurements. We conclude that the variability previously identified as a sharp decline in SPG circulation can be more appropriately attributed to basin-wide sea level rise during the satellite altimetry period. In addition, we find that the properties of the eastern SPG do not covary with the SPG size, suggesting that SPG dynamics do not control the strength of the intergyre throughput.Plain Language SummaryFor over a decade there has been a discrepancy in the observed variability of the size and strength of the subpolar gyre: satellite estimates based on the height of the sea-surface were interpreted as showing a rapid decline in the gyre since the early 1990s, while direct measurements from ships and moorings showed the gyre to be quite stable over the same time period. In this work, we reconcile these two measurement techniques by subtracting the long-term sea

  3. On the significance of nitrification within the euphotic zone of the subpolar North Atlantic (Iceland basin) during summer 2007

    Science.gov (United States)

    Painter, Stuart C.

    2011-11-01

    The oxidation of ammonium to nitrite was investigated within surface waters (< 125 m) of the sub-polar North Atlantic (~ 60°N, 20°W) during late summer 2007. Sampling occurred within a mesoscale eddy dipole system and a definite bias towards waters beneath the euphotic zone as the focus for nitrification was evident. The patchy occurrence of significant nitrification rates within the euphotic zone is interpreted as providing minimal indication for widespread nitrification within surface waters of the sub-polar gyre. However, isolated occurrences of significant nitrification rates within the euphotic zone above the cyclonic eddy were sufficient to account for observed in-situ NO 3-concentrations. It is proposed that the deeper mixed layer associated with the cyclonic eddy enhanced the likelihood of nitrification within the euphotic zone through the vertical displacement of sub-euphotic zone bacterial communities.

  4. Marine diatoms in polar and sub-polar environments and their application to Late Pleistocene paleoclimate reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Crosta, Xavier, E-mail: x.crosta@epoc.u-bordeaux1.fr [UMR-CNRS 5805 EPOC, Universite Bordeaux 1, Avenue des Facultes, 33405 Talence Cedex (France)

    2011-05-15

    Diatoms are one of the major phytoplankton groups in polar and sub-polar marine environments along with green algae and chrysophytes. Diatoms are composed of two components, a two-valve test made of amorphous silica and an organic cell encapsulated into the test. Mucilage covering the test and proteins embedded in the silica lattice of the test completes the organic pool of the diatoms. The preservation of these two components into deep-sea sediments allows for a large set of diatom-based proxies to infer past oceanographic and climatic changes in polar and sub-polar marine environments. Most diatom species in polar and sub-polar marine environments exhibit a narrow range of ecological preferences, especially in terms of sea-surface temperature and sea ice conditions. Preserved diatom assemblages in deep-sea sediments mirror the diatom assemblages in the phytoplankton. It is subsequently possible to extrapolate the relationships between diatom assemblages in surface sediments and modern parameters to down-core fossil assemblages to document past changes in sea-surface temperatures and sea ice conditions. Congruent analysis of biogenic silica and organic carbon and stable isotope ratios (O, Si in the silica matrix and C, N in the diatom-intrinsic organic matter) provides information on siliceous productivity, nutrient cycling and water mass circulation. Measurements of diatom biomarkers give complementary information on sea ice conditions and siliceous productivity.

  5. Snowplow Injection Front Effects

    Science.gov (United States)

    Moore, T. E.; Chandler, M. O.; Buzulukova, N.; Collinson, G. A.; Kepko, E. L.; Garcia-Sage, K. S.; Henderson, M. G.; Sitnov, M. I.

    2013-01-01

    As the Polar spacecraft apogee precessed through the magnetic equator in 2001, Polar encountered numerous substorm events in the region between geosynchronous orbit and 10 RE geocentric distance; most of them in the plasma sheet boundary layers. Of these, a small number was recorded near the neutral sheet in the evening sector. Polar/Thermal Ion Dynamics Experiment provides a unique perspective on the lowest-energy ion plasma, showing that these events exhibited a damped wavelike character, initiated by a burst of radially outward flow transverse to the local magnetic field at approximately 80 km/s. They then exhibit strongly damped cycles of inward/outward flow with a period of several minutes. After one or two cycles, they culminated in a hot plasma electron and ion injection, quite similar to those observed at geosynchronous orbit. Cold plasmaspheric plasmas comprise the outward flow cycles, while the inward flow cycles contain counterstreaming field-parallel polar wind-like flows. The observed wavelike structure, preceding the arrival of an earthward moving substorm injection front, suggests an outward displacement driven by the inward motion at local times closer to midnight, that is, a "snowplow" effect. The damped in/out flows are consistent with interchange oscillations driven by the arrival at the observed local time by an injection originating at greater radius and local time.

  6. Direct observations of formation and propagation of subpolar eddies into the subtropical North Atlantic

    CERN Document Server

    Bower, A S; Amrhein, D E; Lilly, J M

    2011-01-01

    Subsurface float and moored observations are presented to show for the first time the formation and propagation of anticyclonic submesoscale coherent vortices that transport relatively cold, fresh subpolar water to the interior subtropical North Atlantic. Acoustically tracked RAFOS floats released in the southward-flowing Western Boundary Current at the exit of the Labrador Sea reveal the formation of three of these eddies at the southern tip of the Grand Banks (42 N, 50 W). Using a recently developed method to detect eddies in float trajectories and estimate their kinematic properties, it was found that the eddies had average rotation periods of 5--7 days at radii of 1025 km, with mean rotation speeds of up to 0.3 m/s. One especially long-lived (5.1 months) eddy crossed under the Gulf Stream path and translated southwestward in the subtropical recirculation to at least 35 N, where it hit one of the Corner Rise Seamounts. Velocity, temperature and salinity measurements from a nine-month deployment of two moor...

  7. Unusual subpolar North Atlantic phytoplankton bloom in 2010: Volcanic fertilization or North Atlantic Oscillation?

    Science.gov (United States)

    Henson, Stephanie A.; Painter, Stuart C.; Penny Holliday, N.; Stinchcombe, Mark C.; Giering, Sarah L. C.

    2013-10-01

    In summer and autumn 2010, a highly anomalous phytoplankton bloom, with chlorophyll concentration more than double that of previous years, was observed in the Irminger Basin, southwest of Iceland. Two unusual events occurred during 2010 which had the potential to promote the unusual bloom. First, in spring 2010, the Eyjafjallajökull volcano in Iceland erupted, depositing large quantities of tephra into the subpolar North Atlantic. Second, during the winter of 2009/2010 the North Atlantic Oscillation (NAO) became extremely negative, developing into the second strongest negative NAO on record. Hydrographic conditions were highly anomalous in the region, with an influx of freshwater spreading through the basin, and unusual nutrient and mixed layer depth conditions. Here we use a combination of satellite, modeled and in situ data to investigate whether the input of iron from the volcanic eruption or change in hydrographic conditions due to the extreme negative NAO were responsible for the anomalous phytoplankton bloom. We conclude that changes in physical forcing driven by the NAO, and not the volcanic eruption, stimulated the unusual bloom.

  8. Response of the North Atlantic subpolar gyre to persistent North Atlantic oscillation like forcing

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann, Katja; Bentsen, Mats [Nansen Environmental and Remote Sensing Center, Bergen (Norway); Bjerknes Center for Climate Research, Bergen (Norway); Drange, Helge [Nansen Environmental and Remote Sensing Center, Bergen (Norway); Bjerknes Center for Climate Research, Bergen (Norway); University of Bergen, Geophysical Institute, Bergen (Norway); Nansen-Zhu International Research Center, Beijing (China)

    2009-02-15

    The response of the North Atlantic subpolar gyre (SPG) to a persistent positive (or negative) phase of the North Atlantic oscillation (NAO) is investigated using an ocean general circulation model forced with idealized atmospheric reanalysis fields. The integrations are analyzed with reference to a base-line integration for which the model is forced with idealized fields representing a neutral state of the NAO. In the positive NAO case, the results suggest that the well-known cooling and strengthening of the SPG are, after about 10 years, replaced by a warming and subsequent weakening of the SPG. The latter changes are caused by the advection of warm water from the subtropical gyre (STG) region, driven by a spin-up of the Atlantic meridional overturning circulation (AMOC) and the effect of an anomalous wind stress curl in the northeastern North Atlantic, which counteracts the local buoyancy forcing of the SPG. In the negative NAO case, however, the SPG response does not involve a sign reversal, but rather shows a gradual weakening throughout the integration. The asymmetric SPG-response to the sign of persistent NAO-like forcing and the different time scales involved demonstrate strong non-linearity in the North Atlantic Ocean circulation response to atmospheric forcing. The latter finding indicates that analysis based on the arithmetic difference between the two NAO-states, e.g. NAO+ minus NAO-, may hide important aspects of the ocean response to atmospheric forcing. (orig.)

  9. Sediment accumulation and carbon burial rates in subpolar fjords of Svalbard, European Arctic

    Science.gov (United States)

    Szczucinski, W.; Dominiczak, A.; Forwick, M.; Apolinarska, K.; Moskalik, M.; Woszczyk, M.

    2016-02-01

    The Svalbard region is particularly sensitive to global climate changes as proved by modern monitoring data and the past records. One of the most evident results is rapid retreat of glaciers during the post-Little Ice Age period (after 1900) observed in many subpolar fjords in Svalbard. The goal of this study is to assess impact of these changes on sediment accumulation rates and carbon burial rate. The study reviews the existing data and provide new high resolution results on 210Pb and 137Cs-based sediment accumulation as well as organic carbon burial rates from a dozen of cores collected in Hornsund fjord, western Spitsbergen. The results prove the sediment accumulation rate to be in order of several mm to several cm/year and large increase in the area of high accumulation rate due to rapid glaciers retreat and formation of new inner fjord bays. In consequence, the total amount of sediment stored in the fjord increases, as well as increase the carbon burial rates. The available data suggest that this kind of fjords may serve as significant sediment and carbon sinks, largely exceeding other polar marine environments. The study was funded by Polish National Science Centre grant No. 2013/10/E/ST10/00166.

  10. Managing Controversies in the Fuzzy Front End

    DEFF Research Database (Denmark)

    Christiansen, John K.; Gasparin, Marta

    2016-01-01

    This research investigates the controversies that emerge in the fuzzy front end (FFE) and how they are closed so the innovation process can move on. The fuzzy front has been characterized in the literature as a very critical phase, but controversies in the FFE have not been studied before....... The analysis investigates the microprocesses around the controversies that emerge during the fuzzy front end of four products. Five different types of controversies are identified: profit, production, design, brand and customers/market. Each controversy represents a threat, but also an opportunity to search...... demonstrates how the fuzzy front requires managers to deal with controversies that emerge from many different places and involve both human and non-human actors. Closing the controversies requires managers to take account of the situation, identify the problem that needs to be addressed, and initiate a search...

  11. The impact of warm summers on winter convection in the subpolar North Atlantic

    Science.gov (United States)

    Oltmanns, Marilena; Karstensen, Johannes; Fischer, Jürgen

    2017-04-01

    The subpolar North Atlantic (SPNA) is one of the few locations where deep ocean convection occurs and an integral part of the climate system. Some studies have indicated that ocean convection in the SPNA is threatened by enhanced melt water input from Greenland into the Irminger and Labrador Seas. Others have suggested that increased sea surface temperatures in the North Atlantic will lead to a negative North Atlantic Oscillation (NAO) setting several months later. As a negative NAO is associated with decreased ocean heat losses and a larger throughput of warm saline water from the subtropics into the SPNA, both mechanisms — the surface freshening and the warming in a warm summer — could combine to impede ocean convection in the following winter. However, the link between the summer forcing and winter convection has not yet been investigated. Here we present the analysis of a variety of oceanic and atmospheric data sets, including more than a decade long records of moored observations in the Irminger and Labrador Seas, Argo float profiles, remote sensing data and an atmospheric reanalysis, that have been used to investigate the atmospheric and upper ocean variability from summer through winter. We show that particularly warm summers are associated with distinct fresh surface patches in the SPNA that intensify in fall through increased precipitation and persist long into winter while heat losses are reduced. At the same time, the subsurface water is warmer and more saline than after cold summers. Based on the summer forcing, we identify a significant predictive skill of the atmospheric circulation and ocean stratification in winter and illustrate the consequences with regard to the warming, melting and heat flux trends over the last 25 years.

  12. Front matter: Volume 10385

    Science.gov (United States)

    Assoufid, Lahsen; Ohashi, Haruhiko; Asundi, Anand K.

    2017-09-01

    This PDF file contains the front matter associated with SPIE Proceedings Volume 10385, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

  13. Assessing linkages between ice sheet calving, subpolar gyre density and deep water ventilation during the last glaciation

    Science.gov (United States)

    Rutledal, Sunniva; Ninnemann, Ulysses S.; Kleiven, Helga (Kikki) F.; Irvali, Nil

    2017-04-01

    Deep ocean circulation plays an important role in the Earth's climate system and is postulated to be closely linked to ice sheet dynamics and abrupt climate oscillations. However, the nature of this coupling remains unclear. Iceberg and freshwater pulses have been hypothesized as both the trigger for, and the response to, reduced Atlantic meridional overturning circulation (AMOC). Differentiating between these two hypotheses requires high-resolution records constraining the relative timing of ice sheet, freshwater, and ocean circulation changes. Here we assess the relative timing and linkages between iceberg discharge, surface water physical properties in the subpolar gyre, and North Atlantic deep water ventilation using proxy records co-registered in the same sediment sequence. High-resolution stable isotope analysis (δ18O & δ13C ) of planktonic (N. pachyderma (s)) and benthic (C. wuellerstorfi) foraminifera and ice-rafted debris (IRD) records from the core GS15-196-02GC taken in the Irminger basin (59o37.1 N, 40o44.25 W, 2468 water depth) document a clear relationship between increasing freshwater fluxes (IRD and planktonic δ18O), decreasing deep water ventilation (benthic δ13C), and temperature and salinity changes in the subpolar gyre surface waters (planktonic δ18O). Our benthic (C. wuellerstorfi) carbon isotope record documents clear variability in deep ocean ventilation throughout the last glacial and deglacial periods. Notably, periods of high iceberg discharge and freshening of the subpolar gyre surface waters are preceded by decreases in deep water ventilation (benthic δ13C); consistent with the hypothesis that reduced AMOC is important for triggering ice sheet melting/collapse. However, ventilation decreases of similar scale occur without accompanying peaks in IRD, suggesting circulation changes do not always trigger ice sheet collapse. In addition, the periods of weakest ventilation (low benthic δ13C ) are clearly coincident with the largest IRD

  14. Smart Moves.

    Science.gov (United States)

    Hannaford, Carla

    1996-01-01

    Students learn more when they are up, moving, and actively participating. The article discusses what teachers can do to incorporate movement into the classroom every day and describes several exercises from "Brain Gym." A sidebar illustrates the connections between muscular activity, the neural network, and the brain. (SM)

  15. Can Empirical Algorithms Successfully Estimate Aragonite Saturation State in the Subpolar North Atlantic?

    Directory of Open Access Journals (Sweden)

    Daniela Turk

    2017-12-01

    Full Text Available The aragonite saturation state (ΩAr in the subpolar North Atlantic was derived using new regional empirical algorithms. These multiple regression algorithms were developed using the bin-averaged GLODAPv2 data of commonly observed oceanographic variables [temperature (T, salinity (S, pressure (P, oxygen (O2, nitrate (NO3-, phosphate (PO43-, silicate (Si(OH4, and pH]. Five of these variables are also frequently observed using autonomous platforms, which means they are widely available. The algorithms were validated against independent shipboard data from the OVIDE2012 cruise. It was also applied to time series observations of T, S, P, and O2 from the K1 mooring (56.5°N, 52.6°W to reconstruct for the first time the seasonal variability of ΩAr. Our study suggests: (i linear regression algorithms based on bin-averaged carbonate system data can successfully estimate ΩAr in our study domain over the 0–3,500 m depth range (R2 = 0.985, RMSE = 0.044; (ii that ΩAr also can be adequately estimated from solely non-carbonate observations (R2 = 0.969, RMSE = 0.063 and autonomous sensor variables (R2 = 0.978, RMSE = 0.053. Validation with independent OVIDE2012 data further suggests that; (iii both algorithms, non-carbonate (MEF = 0.929 and autonomous sensors (MEF = 0.995 have excellent predictive skill over the 0–3,500 depth range; (iv that in deep waters (>500 m observations of T, S, and O2 may be sufficient predictors of ΩAr (MEF = 0.913; and (iv the importance of adding pH sensors on autonomous platforms in the euphotic and remineralization zone (<500 m. Reconstructed ΩAr at Irminger Sea site, and the K1 mooring in Labrador Sea show high seasonal variability at the surface due to biological drawdown of inorganic carbon during the summer, and fairly uniform ΩAr values in the water column during winter convection. Application to time series sites shows the potential for regionally tuned algorithms, but they need to be further compared against

  16. Overflow Water Pathways in the Subpolar North Atlantic Observed with Deep Floats

    Science.gov (United States)

    Bower, Amy; Furey, Heather; Lozier, Susan

    2017-04-01

    As part of the Overturning in the Subpolar North Atlantic Program (OSNAP), a total of 135 acoustically tracked RAFOS floats have been deployed in the deep boundary currents of the Iceland, Irminger and Labrador Basins, and in the Charlie-Gibbs Fracture Zone, to investigate the pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW). Floats were released annually in 2014, 2015 and 2016 at depths between 1800 and 2800 m for two-year missions. The array of sound sources used for tracking was expanded from 10 to 13 moorings in 2016 when it was discovered that wintertime surface roughness was negatively impacting acoustic ranges. The floats from the first setting reveal several examples of persistent , deep coherent eddy motion, including a cyclonic eddy spinning off the tip of Eirik Ridge (southwest of Cape Farewell), a cyclonic eddy in the northeastern Labrador Basin near where anticyclonic Irminger Rings are formed, and an anticyclonic eddy under the North Atlantic Current (NAC) in the central Iceland Basin. A consistent region of boundary-interior exchange was observed near Hamilton Bank on the western boundary of the Labrador Sea. Deep cyclonic recirculation gyres are revealed in all three basins. Floats released in the southward-flowing deep boundary current over the eastern flank of the Reykjanes Ridge show that shallower layers of ISOW peel off to the west and cross the Ridge into the Irminger Basin through various gaps south of 60°N, including the Bight Fracture Zone. These floats tend to turn northward and continue along the slope in the Irminger Basin. Interestingly, floats released at the ISOW level in the CGFZ did not turn into the Irminger Basin as often depicted in deep circulation schematics, but rather drifted west-northwestward toward the Labrador Sea, or eddied around west of the CGFZ and (in some cases) turned southward. This result is consistent with some previous hydrographic and high-resolution model results

  17. Negative Ion Density Fronts

    Energy Technology Data Exchange (ETDEWEB)

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  18. Wind-induced subduction at the South Atlantic subtropical front

    Science.gov (United States)

    Calil, Paulo H. R.

    2017-10-01

    The South Atlantic Subtropical Front, associated with the eastward-flowing South Atlantic Current, separates the colder, nutrient-rich waters of the subpolar gyre from the warmer, nutrient-poor waters of the subtropical gyre. Perturbations to the quasi-geostrophic, eastward flow generate meanders and filaments which induce cross-frontal exchange of water properties. Down-front winds transport denser waters from the South over warm waters from the North, inducing convective instability and subduction. Such processes occur over spatial scales of the order of 1 km and thus require high horizontal spatial resolution. In this modeling study, a high-resolution (4 km) regional grid is embedded in a basin-wide configuration (12 km) of the South Atlantic Ocean in order to test the importance of submesoscale processes in water mass subduction along the subtropical front. Stronger and more numerous eddies obtained in the high-resolution run yield more intense zonal jets along the frontal zone. Such stronger jets are more susceptible to instabilities, frontogenesis, and the generation of submesoscale meanders and filaments with O(1) Rossby number. As a consequence, vertical velocities larger than 100 md 1 are obtained in the high-resolution run, one order of magnitude larger than in the low-resolution run. Wind-driven subduction occurs along the frontal region, associated with negative Ertel potential vorticity in the surface layer. Such processes are not observed in the low-resolution run. A passive tracer experiment shows that waters with density characteristics similar to subtropical mode waters are preferentially subducted along the frontal region. The wind-driven buoyancy flux is shown to be much larger than thermal or haline fluxes during the wintertime, which highlights the importance of the frictional component in extracting PV from the surface ocean and inducing subduction, a process that has been overlooked in subtropical mode water formation in the region.

  19. Self-controlled moving robot

    Science.gov (United States)

    Lee, Song-Keun; Kim, Il-Ju

    2007-12-01

    We made a self controlled moving robot (SCMR) which tracks the object using the images obtained from two cameras which are installed on the front of the system. In order to reduce the effect of a color and a light we converted the true color images to the gray color images. We can estimate the object movements by utilizing four images which are obtained from two cameras of different times. The SCMR controls the motor to move by itself considering the result of the image processing. In the image processing we used the image zone partition method. The image zone partition method decides a direction that the object is moving. For fast calculation of the image processing and the motor control we installed the personal computer (PC) on the SCMR.

  20. Light-Front QCD

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.

    2004-11-30

    In these lectures, I survey a number of applications of light-front methods to hadron and nuclear physics phenomenology and dynamics, including light-front statistical physics. Light-front Fock-state wavefunctions provide a frame-independent representation of hadrons in terms of their fundamental quark and gluon degrees of freedom. Nonperturbative methods for computing LFWFs in QCD are discussed, including string/gauge duality which predicts the power-law fall-off at high momentum transfer of light-front Fock-state hadronic wavefunctions with an arbitrary number of constituents and orbital angular momentum. The AdS/CFT correspondence has important implications for hadron phenomenology in the conformal limit, including an all-orders derivation of counting rules for exclusive processes. One can also compute the hadronic spectrum of near-conformal QCD assuming a truncated AdS/CFT space. Given the LFWFs, one can compute form factors, heavy hadron decay amplitudes, hadron distribution amplitudes, and the generalized parton distributions underlying deeply virtual Compton scattering. The quantum fluctuations represented by the light-front Fock expansion leads to novel QCD phenomena such as color transparency, intrinsic heavy quark distributions, diffractive dissociation, and hidden-color components of nuclear wavefunctions. A new test of hidden color in deuteron photodisintegration is proposed. The origin of leading-twist phenomena such as the diffractive component of deep inelastic scattering, single-spin asymmetries, nuclear shadowing and antishadowing is also discussed; these phenomena cannot be described by light-front wavefunctions of the target computed in isolation. Part of the anomalous NuTeV results for the weak mixing angle {theta}{sub W} could be due to the non-universality of nuclear antishadowing for charged and neutral currents.

  1. Moving the campaign from the front door to the front pocket

    DEFF Research Database (Denmark)

    Bhatti, Yosef; Dahlgaard, Jens Olav; Hansen, Jonas Hedegaard

    2017-01-01

    Despite the widespread scholarly attention given to get-out-the-vote tactics the recent one and a half decade, few have studied the effect of short text messages (SMS) on voter turnout, and no previous such study has been conducted outside the US. We analyze four SMS experiments with more than 30...

  2. AIRS Storm Front Approaching California (animation)

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for the AIRS Storm Front Approaching California Animation NASA's Atmospheric Infrared Sounder instrument is able to peel back cloud cover to reveal 3-D structure of a storm's water vapor content, information that can be used to improve weather forecast models. In this animation the initial visible cloud image series shows a front moving toward the West Coast of the United States as a low pressure area moves into the Pacific Northwest. The 'Pineapple Express,' a stream of moisture that originates in the tropics South of Hawaii and usually crosses Mexico to enter New Mexico and Texas, has shifted Westward and is also visible moving into Baja California. The area preceding the front appears to be relatively clear in the visible images. As the view shifts from the visible to the infrared wavelengths which highlight water vapor, we see both cloud areas contain heavy burdens of moisture. The area which appears clear in the visible images is seen to contain water vapor near the coastline as well. The viewpoint then rotates so that we can see the vertical cross section of the fronts. The variability of the vertical extent of water vapor and the amount is now clearly visible. The storm moving in from the Gulf of Alaska is more heavily laden with water vapor than that moving in from the Southwest. The moisture is concentrated in the lower atmosphere. The colors indicate the amount of water vapor present. Blue areas denote low water vapor content; green areas are medium water vapor content; red areas signify high water vapor content. The vertical grid for the final frame ranges from 250 millibar pressure at the top to 1000 millibar pressure at the bottom. The top is about 10 km (6.2 miles) above the surface of the Earth. The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments

  3. Dynamics of curved fronts

    CERN Document Server

    Pelce, Pierre

    1989-01-01

    In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.

  4. Low virus to prokaryote ratios in the cold: benthic viruses and prokaryotes in a subpolar marine ecosystem (Hornsund, Svalbard).

    Science.gov (United States)

    Wróbel, Borys; Filippini, Manuela; Piwowarczyk, Joanna; Kedra, Monika; Kuliński, Karol; Middelboe, Mathias

    2013-03-01

    The density and spatial distribution of benthic viruses and prokaryotes in relation to biotic and abiotic factors were investigated in sediment cores collected in Hornsund, a permanently cold fjord on the West coast of Svalbard, Norway. The cores were obtained from the mouth of the fjord to the central basin, along a longitudinal transect. The results of our analyses showed lower densities of viruses (0.2 x 10(8) to 5.4 x 10(8) virus-like particles/g) and lower virus-to-prokaryote ratios (0.2-0.6, with the exception of the uppermost layer in the central basin, where the ratio was about 1.2) at the study site than generally found in the temperate areas, despite the relatively high organic matter content in subpolar sediments. Variations in benthic viral and prokaryote abundances along gradients of particle sedimentation rates, phytopigment concentrations, and macrobenthic species composition together suggested the influence of particle sedimentation and macrobenthic bioturbation on the abundance and spatial distribution ofprokaryotes and viruses in cold habitats.

  5. Ocean and atmosphere coupling, connection between sub-polar Atlantic air temperature, Icelandic minimum and temperature in Serbia

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2009-01-01

    Full Text Available In the presented paper correlation between the northern part of the Atlantic ocean (belt between 50-65°N and the atmospheric pressure is examined. Connection between the ocean temperature and atmospheric pressure is the most obvious in the El Nino southern oscillation mechanism. Thus, so far it is not known that such a mechanism exist in the Atlantic ocean. The main accent in the presented paper is focused on the connection between Iceland low and the sea surface temperature (SST in the subpolar part of the Atlantic ocean (used data are in grid 5x5°. By hierarchical cluster analysis five relatively unified clusters of sea surface temperatures grid cells are defined. By multiple linear regression, we examined the correlation between each of the depicted clusters with position and intensity of Iceland low, and identified the most important grid cells inside every cluster. The analysis of the relation between Iceland low and air temperature in Serbia and Belgrade has shown the strongest correlation for the longitude of this centre of action. .

  6. Front Pages.indd

    African Journals Online (AJOL)

    salah

    forces acting on a small piece of tissue or a microcarrier particle and its move- ... Materials and Methods: The forces of rotational wall vessel (RWV) bioreac- .... tense the collision is. The simultaneous equations from 1-6 can describe the motion of particle in the RWV with inner cylinder. Solving them numerically can obtain ...

  7. Simple Front-End Concept for the Complex Challenges of Multi-Band Communications

    DEFF Research Database (Denmark)

    Buskgaard, Emil Feldborg; Tatomirescu, Alexandru; Barrio, Samantha Caporal Del

    2015-01-01

    This paper proposes a new architecture for mobile phone front-ends that dramatically reduces the complexity of multi-band smart phones. Traditional smart phone front-ends consist of many parallel transmit (Tx) and receive (Rx) chains each dedicated to a single band. The proposed architecture simp...... bands realistic. Current 5G investigations show that the advantages of flexible front-ends will be even bigger as technology moves toward software defined radio. \\end{abstract}...

  8. High Abundance of the Epibenthic Trachymedusa Ptychogastria polaris Allman, 1878 (Hydrozoa, Trachylina) in Subpolar Fjords along the West Antarctic Peninsula.

    Science.gov (United States)

    Grange, Laura J; Smith, Craig R; Lindsay, Dhugal J; Bentlage, Bastian; Youngbluth, Marsh J

    2017-01-01

    Medusae can be conspicuous and abundant members of seafloor communities in deep-sea benthic boundary layers. The epibenthic trachymedusa, Ptychogastria polaris Allman, 1878 (Hydrozoa: Trachylina: Ptychogastriidae) occurs in the cold, high latitude systems of both the northern and southern hemispheres, with a circumpolar distribution in Arctic and sub-Arctic areas, and disjunct reports of a few individuals from Antarctica. In January-February 2010, during benthic megafaunal photosurveys in three subpolar fjords along the West Antarctic Peninsula (Andvord, Flandres and Barilari Bays), P. polaris was recorded in Antarctic Peninsula waters. The trachymedusa, identified from megacore-collected specimens, was a common component of the epifauna in the sediment floored basins at 436-725 m depths in Andvord and Flandres Bays, reaching densities up to 13 m-2, with mean densities in individual basins ranging from 0.06 to 4.19 m-2. These densities are 2 to 400-fold higher than previously reported for P. polaris in either the Arctic or Antarctic. This trachymedusa had an aggregated distribution, occurring frequently in Andvord Bay, but was often solitary in Flandres Bay, with a distribution not significantly different from random. Epibenthic individuals were similar in size, typically measuring 15-25 mm in bell diameter. A morphologically similar trachymedusa, presumably the same species, was also observed in the water column near the bottom in all three fjords. This benthopelagic form attained abundances of up to 7 m-2 of seafloor; however, most P. polaris (~ 80%), were observed on soft sediments. Our findings indicate that fjords provide a prime habitat for the development of dense populations of P. polaris, potentially resulting from high and varied food inputs to the fjord floors. Because P. polaris resides in the water column and at the seafloor, large P. polaris populations may contribute significantly to pelagic-benthic coupling in the WAP fjord ecosystems.

  9. High Abundance of the Epibenthic Trachymedusa Ptychogastria polaris Allman, 1878 (Hydrozoa, Trachylina in Subpolar Fjords along the West Antarctic Peninsula.

    Directory of Open Access Journals (Sweden)

    Laura J Grange

    Full Text Available Medusae can be conspicuous and abundant members of seafloor communities in deep-sea benthic boundary layers. The epibenthic trachymedusa, Ptychogastria polaris Allman, 1878 (Hydrozoa: Trachylina: Ptychogastriidae occurs in the cold, high latitude systems of both the northern and southern hemispheres, with a circumpolar distribution in Arctic and sub-Arctic areas, and disjunct reports of a few individuals from Antarctica. In January-February 2010, during benthic megafaunal photosurveys in three subpolar fjords along the West Antarctic Peninsula (Andvord, Flandres and Barilari Bays, P. polaris was recorded in Antarctic Peninsula waters. The trachymedusa, identified from megacore-collected specimens, was a common component of the epifauna in the sediment floored basins at 436-725 m depths in Andvord and Flandres Bays, reaching densities up to 13 m-2, with mean densities in individual basins ranging from 0.06 to 4.19 m-2. These densities are 2 to 400-fold higher than previously reported for P. polaris in either the Arctic or Antarctic. This trachymedusa had an aggregated distribution, occurring frequently in Andvord Bay, but was often solitary in Flandres Bay, with a distribution not significantly different from random. Epibenthic individuals were similar in size, typically measuring 15-25 mm in bell diameter. A morphologically similar trachymedusa, presumably the same species, was also observed in the water column near the bottom in all three fjords. This benthopelagic form attained abundances of up to 7 m-2 of seafloor; however, most P. polaris (~ 80%, were observed on soft sediments. Our findings indicate that fjords provide a prime habitat for the development of dense populations of P. polaris, potentially resulting from high and varied food inputs to the fjord floors. Because P. polaris resides in the water column and at the seafloor, large P. polaris populations may contribute significantly to pelagic-benthic coupling in the WAP fjord

  10. Environmental Controls on Mg/Ca in Neogloboquadrina incompta: A Core-Top Study From the Subpolar North Atlantic

    Science.gov (United States)

    Morley, Audrey; Babila, Tali L.; Wright, James; Ninnemann, Ulysses; Kleiven, Kikki; Irvali, Nil; Rosenthal, Yair

    2017-12-01

    Magnesium/calcium paleothermometry is an established tool for reconstructing past surface and deep-sea temperatures. However, our understanding of nonthermal environmental controls on the uptake of Mg into the calcitic lattice of foraminiferal tests remains limited. Here we present a combined analysis of multiple trace element/calcium ratios and stable isotope (δ18O and δ13C) geochemistry on the subpolar planktonic foraminifera Neogloboquadrina incompta to assess the validity of Mg/Ca as a proxy for surface ocean temperature. We identify small size-specific offsets in Mg/Ca and δ18Oc values for N. incompta that are consistent with depth habitat migration patterns throughout the life cycle of this species. Additionally, an assessment of nonthermal controls on Mg/Ca values reveals that (1) the presence of volcanic ash, (2) the addition of high-Mg abiotic overgrowths, and (3) ambient seawater carbonate chemistry can have a significant impact on the Mg/Ca-to-temperature relationship. For carbonate-ion concentrations of values > 200 μmol kg-1, we find that temperature exerts the dominant control on Mg/Ca values, while at values < 200 μmol kg-1 the carbonate-ion concentration of seawater increases the uptake of Mg, thereby resulting in higher-than-expected Mg/Ca values at low temperatures. We propose two independent correction schemes to remove the effects of volcanic ash and carbonate-ion concentration on Mg/Ca values in N. incompta within the calibration data set. Applying the corrections improves the fidelity of past ocean temperature reconstructions.

  11. Studies of Labrador Sea Water formation and variability in the subpolar North Atlantic in the light of international partnership and collaboration

    Science.gov (United States)

    Kieke, Dagmar; Yashayaev, Igor

    2015-03-01

    Labrador Sea Water (LSW), the lightest contribution to North Atlantic Deep Water (NADW) and one of the most prominent water masses of the subpolar North Atlantic, has seen remarkable changes over the past century. LSW originates in the Labrador Sea, where it is formed through wintertime ocean convection of varying intensity, depth and spatial extent. Formation of LSW, followed by its respective injection into the mid-depth circulation system, is mandatory for ventilating and renewing water layers of the interior ocean. Indispensably important for unraveling the history of variability in formation and properties of LSW as well as for mapping its large-scale spreading and export are sustained physical and chemical observations from the deep ocean. These observations started at the beginning of the 20th century from occasional mostly national surveys and today constitute large-scale multi-national collaborative efforts including a vast arsenal of sophisticated instrumentation. In a historical context, we revisit major milestones over the past 100 years which have established and are constantly adding to shaping today's knowledge on LSW, and present first details on the latest vintage of LSW generated during the strong winter of 2013/2014. Respective Argo data reveal mixed-layer depths greater than 1700 m marking formation of a new cold and fresh anomaly that has spread since then over the subpolar North Atlantic. We further summarize the on-going observational efforts in the subpolar North Atlantic and present a compilation of hydrographic standard lines that serve to provide top-to-bottom information on NADW components.

  12. Active learning of Pareto fronts.

    Science.gov (United States)

    Campigotto, Paolo; Passerini, Andrea; Battiti, Roberto

    2014-03-01

    This paper introduces the active learning of Pareto fronts (ALP) algorithm, a novel approach to recover the Pareto front of a multiobjective optimization problem. ALP casts the identification of the Pareto front into a supervised machine learning task. This approach enables an analytical model of the Pareto front to be built. The computational effort in generating the supervised information is reduced by an active learning strategy. In particular, the model is learned from a set of informative training objective vectors. The training objective vectors are approximated Pareto-optimal vectors obtained by solving different scalarized problem instances. The experimental results show that ALP achieves an accurate Pareto front approximation with a lower computational effort than state-of-the-art estimation of distribution algorithms and widely known genetic techniques.

  13. Fronts in Large Marine Ecosystems

    Science.gov (United States)

    Belkin, Igor M.; Cornillon, Peter C.; Sherman, Kenneth

    2009-04-01

    Oceanic fronts shape marine ecosystems; therefore front mapping and characterization are among the most important aspects of physical oceanography. Here we report on the first global remote sensing survey of fronts in the Large Marine Ecosystems (LME). This survey is based on a unique frontal data archive assembled at the University of Rhode Island. Thermal fronts were automatically derived with the edge detection algorithm of Cayula and Cornillon (1992, 1995, 1996) from 12 years of twice-daily, global, 9-km resolution satellite sea surface temperature (SST) fields to produce synoptic (nearly instantaneous) frontal maps, and to compute the long-term mean frequency of occurrence of SST fronts and their gradients. These synoptic and long-term maps were used to identify major quasi-stationary fronts and to derive provisional frontal distribution maps for all LMEs. Since SST fronts are typically collocated with fronts in other water properties such as salinity, density and chlorophyll, digital frontal paths from SST frontal maps can be used in studies of physical-biological correlations at fronts. Frontal patterns in several exemplary LMEs are described and compared, including those for: the East and West Bering Sea LMEs, Sea of Okhotsk LME, East China Sea LME, Yellow Sea LME, North Sea LME, East and West Greenland Shelf LMEs, Newfoundland-Labrador Shelf LME, Northeast and Southeast US Continental Shelf LMEs, Gulf of Mexico LME, and Patagonian Shelf LME. Seasonal evolution of frontal patterns in major upwelling zones reveals an order-of-magnitude growth of frontal scales from summer to winter. A classification of LMEs with regard to the origin and physics of their respective dominant fronts is presented. The proposed classification lends itself to comparative studies of frontal ecosystems.

  14. Unveiling current Guanaco distribution in chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests.

    Directory of Open Access Journals (Sweden)

    Benito A González

    provides a scientific tool to further develop large scale plans for habitat conservation and preservation of intraspecific genetic variability for this far ranging South American camelid, which inhabits a diversity of ecoregion types from Andean puna to subpolar forests.

  15. Device for leveling the front of a section timbering

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, N.D.; Grebenkin, S.S.; Samoylov, A.V.

    1980-02-28

    The device for leveling the front section timbering contains winches for moving the sections, a cable arranged along the timbering and attached to the end sections, tension attachment arranged on one of the terminal sections, and hydraulic winches for moving the cable hinged by means of mobile bushings to the cable and by means of pins to the timbering sections. To compensate for the spacing errors of any sign during movement of the sections it has hydraulic distributors which are established in the hydraulic system of winches for moving the sections, and sensors for controlling the hydraulic distributors installed in the hydraulic winches for moving the cable and made in the form of sensors of terminal position.

  16. Sea surface temperature and sea ice variability in the sub-polar North Atlantic from explosive volcanism of the late thirteenth century

    DEFF Research Database (Denmark)

    Sicre, M.-A.; Khodri, M.; Mignot, J.

    2013-01-01

    In this study, we use IP25 and alkenone biomarker proxies to document the subdecadal variations of sea ice and sea surface temperature in the subpolar North Atlantic induced by the decadally paced explosive tropical volcanic eruptions of the second half of the thirteenth century. The short-and lo...... and subsurface heat buildup due to sea ice capping. As volcanic forcing relaxes, the surface ocean rapidly warms, likely amplified by subsurface heat, and remains almost ice free for several decades.......In this study, we use IP25 and alkenone biomarker proxies to document the subdecadal variations of sea ice and sea surface temperature in the subpolar North Atlantic induced by the decadally paced explosive tropical volcanic eruptions of the second half of the thirteenth century. The short-and long......-term evolutions of both variables were investigated by cross analysis with a simulation of the IPSL-CM5A LR model. Our results show short-term ocean cooling and sea ice expansion in response to each volcanic eruption. They also highlight that the long response time of the ocean leads to cumulative surface cooling...

  17. Large bio-geographical shifts in the north-eastern Atlantic Ocean: From the subpolar gyre, via plankton, to blue whiting and pilot whales

    Science.gov (United States)

    Hátún, H.; Payne, M. R.; Beaugrand, G.; Reid, P. C.; Sandø, A. B.; Drange, H.; Hansen, B.; Jacobsen, J. A.; Bloch, D.

    2009-03-01

    Pronounced changes in fauna, extending from the English Channel in the south to the Barents Sea in the north-east and off Greenland in the north-west, have occurred in the late 1920s, the late 1960s and again in the late 1990s. We attribute these events to exchanges of subarctic and subtropical water masses in the north-eastern North Atlantic Ocean, associated with changes in the strength and extent of the subpolar gyre. These exchanges lead to variations in the influence exerted by the subarctic or Lusitanian biomes on the intermediate faunistic zone in the north-eastern Atlantic. This strong and persistent bottom-up bio-physical link is demonstrated using a numerical ocean general circulation model and data on four trophically connected levels in the food chain - phytoplankton, zooplankton, blue whiting, and pilot whales. The plankton data give a unique basin-scale depiction of these changes, and a long pilot whale record from the Faroe Islands offers an exceptional temporal perspective over three centuries. Recent advances in simulating the dynamics of the subpolar gyre suggests a potential for predicting the distribution of the main faunistic zones in the north-eastern Atlantic a few years into the future, which might facilitate a more rational management of the commercially important fisheries in this region.

  18. MOVES sensitivity study

    Science.gov (United States)

    2012-01-01

    Purpose: : To determine ranking of important parameters and the overall sensitivity to values of variables in MOVES : To allow a greater understanding of the MOVES modeling process for users : Continued support by FHWA to transportation modeling comm...

  19. "Front" hotshet izvinitsja / Aleksandr Ikonnikov

    Index Scriptorium Estoniae

    Ikonnikov, Aleksandr

    2003-01-01

    Põhiliselt vene rahvusest noori ühendava liikumise "Front" esindajad kavatsevad kohtuda USA suursaadikuga Eestis ja vabandada kevadel suursaatkonna ees vägivallatsemisega lõppenud meeleavalduse pärast

  20. Front dynamics in turbulent media

    CERN Document Server

    Martí, A C; Sancho, J M

    1997-01-01

    A study of a stable front propagating in a turbulent medium is presented. The front is generated through a reaction-diffusion equation, and the turbulent medium is statistically modeled using a Langevin equation. Numerical simulations indicate the presence of two different dynamical regimes. These regimes appear when the turbulent flow either wrinkles a still rather sharp propagating interfase or broadens it. Specific dependences of the propagating velocities on stirring intensities appropriate to each case are found and fitted when possible according to theoretically predicted laws. Different turbulent spectra are considered.

  1. Moving? A Relocation Guide.

    Science.gov (United States)

    Rackliffe, Gary; Pearson, Nancy

    This guide answers questions for high school graduates moving away from home for the first time. The question and answer format begins with reasons for moving and offers ways of finding information about a new town before leaving, meeting people, and fighting homesickness and indecision. Practical advice is presented on money management and…

  2. Moving Field Guides

    Science.gov (United States)

    Cassie Meador; Mark Twery; Meagan. Leatherbury

    2011-01-01

    The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

  3. Moving a House by Moved Participants

    DEFF Research Database (Denmark)

    Axel, Erik

    The author performed an investigation of how a house was designed. He participated mainly in meetings, in which the house was engineered. The meetings proceeded in an agreeable atmosphere. While the architect was mostly concerned with integrating the functionality of the house, the engineer engaged...... had the drawing for an upcoming discussion, he was also helpful, e.g. when somebody had to compute something he produced a calculator and assisted in the computation. Once at a meeting the participants had to deal with a request from the city: could the house be moved one meter towards the curb...... of moving the house with respect to its servicing pipes. It was immediately underlined that this task was a surplus task and would therefore trigger an extra payment. When I interviewed the participants and asked them how they understood the function of the engineer, they revealed some irritation, since...

  4. Embodied affectivity: on moving and being moved.

    Science.gov (United States)

    Fuchs, Thomas; Koch, Sabine C

    2014-01-01

    There is a growing body of research indicating that bodily sensation and behavior strongly influences one's emotional reaction toward certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject's bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection) and moved to move (action; expression; e-motion). Through its resonance, the body functions as a medium of emotional perception: it colors or charges self-experience and the environment with affective valences while it remains itself in the background of one's own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner's affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self.

  5. Embodied affectivity: On moving and being moved

    Directory of Open Access Journals (Sweden)

    Thomas eFuchs

    2014-06-01

    Full Text Available There is a growing body of research indicating that bodily sensation and behaviour strongly influences one’s emotional reaction towards certain situations or objects. On this background, a framework model of embodied affectivity is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject’s bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection and moved to move (action; expression; e-motion. Through its resonance, the body functions as a medium of emotional perception: it colours or charges self-experience and the environment with affective valences while it remains itself in the background of one’s own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner’s affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self.

  6. Solution of transient problems with steep gradients: novel front-tracking strategy

    DEFF Research Database (Denmark)

    Kiil, Søren; Bhatia, Suresh K.; Dam-Johansen, Kim

    1995-01-01

    A finite element collocation method is formulated for heat and mass transfer problems involving a steep moving profile of the dependant variable. An efficient, parametrically convergent front-tracking procedure is developed based on a balance on a moving front, and the technique is applied...... and tested for the case of a gas-solid noncatalytic reaction in a porous solid at high Thiele modulus. Accurate and convergent steep profiles are obtained here for Thiele modulus larger than 50 for the case of slab as well as spherical geometry and found to match the analytical solution when it exists (such...... as for slab geometry)....

  7. PARALLEL MOVING MECHANICAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberius Petrescu

    2014-09-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines a few main elements of Stewart platforms. Begin with the geometry platform, kinematic elements of it, and presented then and a few items of dynamics. Dynamic primary element on it means the determination mechanism kinetic energy of the entire Stewart platforms. It is then in a record tail cinematic mobile by a method dot matrix of rotation. If a structural mottoelement consists of two moving elements which translates relative, drive train and especially dynamic it is more convenient to represent the mottoelement as a single moving components. We have thus seven moving parts (the six motoelements or feet to which is added mobile platform 7 and one fixed.

  8. The Moving image

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner.......Every day we are presented with bodily expressions in audiovisual media – by anchors, journalists and characters in films for instance. This article explores how body language in the moving image has been and can be approached in a scholarly manner....

  9. Shifts of the Subtropical Shelf Front controlled by atmospheric variations

    Science.gov (United States)

    Balcerak, Ernie

    2013-10-01

    In the western South Atlantic, off the coast of South America, a band of cold, fresh, nutrient-rich Sub-Antarctic Shelf Water (SASW) meets warm, salty, nutrient-poor Subtropical Shelf Water (STSW) to form the Subtropical Shelf Front (STSF). This front is the shallow-water expression of the major Brazil-Malvinas Confluence Zone and has moved northward and southward during the Holocene (the past ~12,000 years). Bender et al. reconstruct the latitudinal shifts of the STSF over the past 11,000 calendar-equivalent years using records of oxygen and carbon stable isotope compositions of benthic foraminifera and total organic carbon and calcium carbonate content from a sediment record collected off Uruguay. These measurements serve as proxies for ocean water temperature and nutrient content, which can be used to distinguish the SASW and STSW.

  10. Firing up the front line.

    Science.gov (United States)

    Katzenbach, J R; Santamaria, J A

    1999-01-01

    For many organizations, achieving competitive advantage means eliciting superior performance from employees on the front line--the burger flippers, hotel room cleaners, and baggage handlers whose work has an enormous effect on customers. That's no easy task. Front line workers are paid low wages, have scant hope of advancement, and--not surprisingly--often care little about the company's performance. But then how do some companies succeed in engaging the emotional energy of rank-and-file workers? A team of researchers at McKinsey & Company and the Conference Board recently explored that question and discovered that one highly effective route is demonstrated by the U.S. Marine Corps. The Marines' approach to motivation follows the "mission, values, and pride" path, which researchers say is practical and relevant for the business world. More specifically, the authors say the Marines follow five practices: they over-invest in cultivating core value; prepare every person to lead, including front line supervisors; learn when to create teams and when to create single-leader work groups; attend to all employees, not just the top half; and encourage self-discipline as a way of building pride. The authors admit there are critical differences between the Marines and most businesses. But using vivid examples from companies such as KFC and Marriott International, the authors illustrate how the Marines' approach can be translated for corporate use. Sometimes, the authors maintain, minor changes in a company's standard operating procedure can have a powerful effect on front line pride and can result in substantial payoffs in company performance.

  11. MOVES regional level sensitivity analysis

    Science.gov (United States)

    2012-01-01

    The MOVES Regional Level Sensitivity Analysis was conducted to increase understanding of the operations of the MOVES Model in regional emissions analysis and to highlight the following: : the relative sensitivity of selected MOVES Model input paramet...

  12. How Reflected Wave Fronts Dynamically Establish Hooke's Law in a Spring

    Science.gov (United States)

    Fahy, Stephen; O'Riordan, John; O'Sullivan, Colm; Twomey, Patrick

    2012-01-01

    A simple benchtop experiment in which a moving cart collides with a fixed spring is described. Force-time and force-distance data recorded during the collision display the transit of compression wave fronts through the spring following impact. These data can be used by students to develop a computational model of the dynamics of this simple…

  13. And Yet It Moves

    Science.gov (United States)

    Silverman, Mark P.

    1993-06-01

    Preface. The fire within; 1. The unimaginably strange behaviour of free electrons; 2. Quantum beats and giant atoms; 3. And yet it moves: exotic atoms and the invariance of charge; 4. Reflections on light; 5. Two worlds, large and small: Earth and atom; 6. The Wirbelrohr's roar (...or rather whistle); 7. Science and wonder; Selected papers by the author; Index.

  14. And Still They Moved

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 10. And Still they Moved - An Important Statement about some Rock Masses. Ramesh Chander. General Article Volume 3 Issue 10 October 1998 pp 41-48. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Moving beyond Disability

    NARCIS (Netherlands)

    Geertzen, Jan H. B.

    2008-01-01

    Moving beyond Disability was the theme of the 12th World Congress of the International Society for Prosthetics and Orthotics. This paper is a reflection of one of the keynote lectures discussing the International Classification of Functioning, Disability and Health (ICF). Multicultural aspects in

  16. Moving Spatial Keyword Queries

    DEFF Research Database (Denmark)

    Wu, Dingming; Yiu, Man Lung; Jensen, Christian S.

    2013-01-01

    Web users and content are increasingly being geo-positioned. This development gives prominence to spatial keyword queries, which involve both the locations and textual descriptions of content. We study the efficient processing of continuously moving top-k spatial keyword (MkSK) queries over spatial...

  17. Moving into an interaction

    DEFF Research Database (Denmark)

    Mortensen, Kristian; Hazel, Spencer

    2014-01-01

    Opening an interaction is a crucial step in establishing and maintaining social relationships. In this paper we describe how participants in an institutional setting, a help desk counter for exchange students at an international university, literally move into interaction. This is accomplished...

  18. Numerical simulation on the multiple dipolarization fronts in the magnetotail

    Science.gov (United States)

    Lu, Haoyu; Li, Yun; Cao, Jinbin; Ge, Yasong; Zhang, Tielong; Yu, Yiqun

    2017-10-01

    Using an extended MHD model including the Hall effect and finite Larmor radius effect, we reproduce multiple dipolarization fronts (DFs) associated with the interchange instability in the braking region of bursty bulk flow in the plasma sheet. Our simulations reveal that the multiple DFs produced by the interchange instability are "growing" type DFs because the maximum plasma flow speeds are behind the fronts. Both the earthward and tailward moving DFs can be produced by interchange instability in the near-Earth region. The Hall electric field is the dominant electric field component in the dip region and the DF layer. The convective and the electron pressure gradient electric field components are smaller. The sharp Bz changes in both the dip region and DF layer correspond to the oppositely directed currents that are primarily associated with electrons. The ion diamagnetic current due to the strong ion pressure gradient causes an intense downward current in the dip region, which can produce the dip ahead of the front. The energy dissipations in the dip region and DF layer are dominated by ions through the work done by the Lorentz force. Our simulation results indicate that the magnetic energy can be converted to plasmas on the DF layer, and vice versa in the dip region.

  19. Front propagation and rejuvenation in flipping processes

    Energy Technology Data Exchange (ETDEWEB)

    Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, P I [BOSTON UNIV; Antal, T [HARVARD UNIV; Ben - Avrahm, D [HARVARD UNIV

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess {Delta}{sub k} increases logarithmically, {Delta}{sub k} {approx_equal}ln k, with the distance k from the front. Third, the front exhibits ageing -- young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

  20. Reaction front formation in contaminant plumes.

    Science.gov (United States)

    Cribbin, Laura B; Winstanley, Henry F; Mitchell, Sarah L; Fowler, Andrew C; Sander, Graham C

    2014-12-15

    The formation of successive fronts in contaminated groundwater plumes by subsoil bacterial action is a commonly accepted feature of their propagation, but it is not obviously clear from a mathematical standpoint quite how such fronts are formed or propagate. In this paper we show that these can be explained by combining classical reaction-diffusion theory involving just two reactants (oxidant and reductant), and a secondary reaction in which a reactant on one side of such a front is (re-)formed on the other side of the front via diffusion of its product across the front. We give approximate asymptotic solutions for the reactant profiles, and the propagation rate of the front. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. CERN Pension Fund move

    CERN Multimedia

    HR Department

    2007-01-01

    The CERN Pension Fund has moved to new offices on the 5th floor of Building 5. The Benefits Service of the Fund is now located in Offices 5-5-017 - 5-5-021 - 5-5-023. We remind you that the office hours are: Tuesday/Wednesday/Thursday from 10 am to 12 am and from 3 pm to 5 pm. The Fund would like to take this opportunity to warmly thank all the persons involved in the relocation.

  2. Lecture - "Move! Eat better"

    CERN Multimedia

    2012-01-01

    As part of the "Move! Eat better" campaign, Novae’s nutrition adviser, Irène Rolfo, will give a talk on the subject of everyday good nutrition. This will be held in the main building auditorium at 12:30 on Thursday, 20 September 2012. Don’t miss this informative event. For more information, go to http://cern.ch/bpmm            

  3. Time to Move On?

    DEFF Research Database (Denmark)

    Valentino, A.; Nell, Phillip Christopher; Hotho, Jasper J.

    Building on prior research, we examine theoretically the institutional factors that push top managers to relocate HQ units overseas. To this end, we first discuss how coercive, isomorphic, and normative pressures may differentially affect HQ relocation decisions. Subsequently, we consider how......, we expect economic crises to decrease the overall institutional quality in a given country context, pushing firms to move out. Our theoretical framework contributes to an improved understanding of how institutional factors influence firm behaviour under varying environmental conditions. Furthermore...

  4. Time to Move On?

    DEFF Research Database (Denmark)

    Valentino, Alfredo; Nell, Phillip; Hotho, Jasper

    2013-01-01

    Building on prior research, we examine theoretically the institutional factors that push top managers to relocate HQ units overseas. To this end, we first discuss how coercive, isomorphic, and normative pressures may differentially affect HQ relocation decisions. Subsequently, we consider how......, we expect economic crises to decrease the overall institutional quality in a given country context, pushing firms to move out. Our theoretical framework contributes to an improved understanding of how institutional factors influence firm behaviour under varying environmental conditions. Furthermore...

  5. A moving experience !

    CERN Multimedia

    2005-01-01

    The Transport Service pulled out all the stops and, more specifically, its fleet of moving and lifting equipment for the Discovery Monday on 6 June - a truly moving experience for all the visitors who took part ! Visitors could play at being machine operator, twiddling the controls of a lift truck fitted with a jib to lift a dummy magnet into a wooden mock-up of a beam-line.They had to show even greater dexterity for this game of lucky dip...CERN-style.Those with a head for heights took to the skies 20 m above ground in a telescopic boom lift.Children were allowed to climb up into the operator's cabin - this is one of the cranes used to move the LHC magnets around. Warm thanks to all members of the Transport Service for their participation, especially B. Goicoechea, T. Ilkei, R. Bihery, S. Prodon, S. Pelletier, Y. Bernard, A.  Sallot, B. Pigeard, S. Guinchard, B. Bulot, J. Berrez, Y. Grandjean, A. Bouakkaz, M. Bois, F. Stach, T. Mazzarino and S. Fumey.

  6. Muon front end for the neutrino factory

    Directory of Open Access Journals (Sweden)

    C. T. Rogers

    2013-04-01

    Full Text Available In the neutrino factory, muons are produced by firing high-energy protons onto a target to produce pions. The pions decay to muons and pass through a capture channel known as the muon front end, before acceleration to 12.6 GeV. The muon front end comprises a variable frequency rf system for longitudinal capture and an ionization cooling channel. In this paper we detail recent improvements in the design of the muon front end.

  7. Chiral symmetry in light-front QCD

    Science.gov (United States)

    Wu, Menh-Hsiu; Zhang, Wei-Min

    2004-04-01

    The definition of chiral transformations in light-front field theory is very different from the conventional form in equal-time formalism. We study the consistency of chiral transformations and chiral symmetry in light-front QCD and derive a complete new light-front axial-vector current for QCD. The breaking of chiral symmetry in light-front QCD is only associated with helicity flip interaction between quarks and gluons. Remarkably, the new axial-vector current does not contain the pion pole part so that the associate chiral charge smoothly describes pion transitions for various hadronic processes.

  8. Chiral Symmetry in Light-front QCD

    OpenAIRE

    Wu, Meng-Hsiu; Zhang, Wei-Min

    2003-01-01

    The definition of chiral transformations in light-front field theory is very different from the conventional form in equal-time formalism. We study the consistency of chiral transformations and chiral symmetry in light-front QCD and derive a complete new light-front axial-vector current for QCD. The breaking of chiral symmetry in light-front QCD is only associated with helicity flip interaction between quarks and gluons. Remarkably, the new axial-vector current does not contain the pion pole ...

  9. Front blind spot crashes in Hong Kong.

    Science.gov (United States)

    Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

    2016-09-01

    In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Deep oceanic circulation in subpolar North Atlantic over the last 60 ka : a synthesis of multi-proxy approach based on Marion Dufresne cores

    Science.gov (United States)

    Kissel, Catherine; Laj, Carlo; Van Toer, Aurélie; Wandres, Camille; Michel, Elisabeth

    2015-04-01

    Different cruises on board the R. V. Marion Dufresne allowed to take cores along the paths of the main overflow waters in sub-polar North Atlantic. The cores studied for glacial period are characterized by deposition rates ranging from 8 to 24 cm/ka and those studied for the Holocene period have sedimentation rates between about 90 and 15 cm/ka. Multi-proxy approach was conducted each time with the magnetic properties as the common studied parameters, used as bottom-current tracer. These properties were coupled, depending on the cores, with oxygen and carbon isotopes of planktonic and benthic foraminifera, sortable silt, IRD counting. The rationale for the study of magnetic properties is linked to the path of the overflow waters over the sills between Greenland and Iceland and between Iceland-Faeroe and Scotland after they form in the Nordic seas. These sills are rich in magnetic particles deposited from the volcanic-rich surrounding areas and they are then more or less efficiently transported in sub-polar North Atlantic by the overflow waters depending on the intensity of the later. During the last glacial period, all the CALYPSO cores distributed from the Norwegian sea to the Bermuda Rise exhibit the same pattern of variations in magnetic concentration. The age models are based on correlation between planktonic delta18O of a core nearby Greenland and delta18O in Greenland ice (Voelker et al., 1998) and confirmed by a perfect fit between the continuous earth magnetic field intensity profile retrieved from sediments and from ice via cosmogenic isotopes. It shows that every minimum in magnetic concentration, also characterized by high IRD content, fresh surface waters, fine mean grain size in the sortable silt range, coincides with cold periods in Greenland. A synthetic "contourite drift deposit" curve has been constructed and illustrate continuously the variations in the intensity of the overflow waters during glacial time. They mimic in phase and in relative

  11. The GEOVIDE cruise in May–June 2014 reveals an intense Meridional Overturning Circulation over a cold and fresh subpolar North Atlantic

    Directory of Open Access Journals (Sweden)

    P. Zunino

    2017-11-01

    Full Text Available The GEOVIDE cruise was carried out in the subpolar North Atlantic (SPNA along the OVIDE section and across the Labrador Sea in May–June 2014. It was planned to clarify the distribution of the trace elements and their isotopes in the SPNA as part of the GEOTRACES international program. This paper focuses on the state of the circulation and distribution of thermohaline properties during the cruise. In terms of circulation, the comparison with the 2002–2012 mean state shows a more intense Irminger Current and also a weaker North Atlantic Current, with a transfer of volume transport from its northern to its central branch. However, those anomalies are compatible with the variability already observed along the OVIDE section in the 2000s. In terms of properties, the surface waters of the eastern SPNA were much colder and fresher than the averages over 2002–2012. In spite of negative temperature anomalies in the surface waters, the heat transport across the OVIDE section estimated at 0.56 ± 0.06 PW was the largest measured since 2002. This relatively large value is related to the relatively strong Meridional Overturning Circulation measured across the OVIDE section during GEOVIDE (18.7 ± 3.0 Sv. By analyzing the air–sea heat and freshwater fluxes over the eastern SPNA in relation to the heat and freshwater content changes observed during 2013 and 2014, we concluded that on a short timescale these changes were mainly driven by air–sea heat and freshwater fluxes rather than by ocean circulation.

  12. The GEOVIDE cruise in May-June 2014 reveals an intense Meridional Overturning Circulation over a cold and fresh subpolar North Atlantic

    Science.gov (United States)

    Zunino, Patricia; Lherminier, Pascale; Mercier, Herlé; Daniault, Nathalie; García-Ibáñez, Maribel I.; Pérez, Fiz F.

    2017-11-01

    The GEOVIDE cruise was carried out in the subpolar North Atlantic (SPNA) along the OVIDE section and across the Labrador Sea in May-June 2014. It was planned to clarify the distribution of the trace elements and their isotopes in the SPNA as part of the GEOTRACES international program. This paper focuses on the state of the circulation and distribution of thermohaline properties during the cruise. In terms of circulation, the comparison with the 2002-2012 mean state shows a more intense Irminger Current and also a weaker North Atlantic Current, with a transfer of volume transport from its northern to its central branch. However, those anomalies are compatible with the variability already observed along the OVIDE section in the 2000s. In terms of properties, the surface waters of the eastern SPNA were much colder and fresher than the averages over 2002-2012. In spite of negative temperature anomalies in the surface waters, the heat transport across the OVIDE section estimated at 0.56 ± 0.06 PW was the largest measured since 2002. This relatively large value is related to the relatively strong Meridional Overturning Circulation measured across the OVIDE section during GEOVIDE (18.7 ± 3.0 Sv). By analyzing the air-sea heat and freshwater fluxes over the eastern SPNA in relation to the heat and freshwater content changes observed during 2013 and 2014, we concluded that on a short timescale these changes were mainly driven by air-sea heat and freshwater fluxes rather than by ocean circulation.

  13. $\\mathit {SH}(3)$-move and other local moves on knots

    OpenAIRE

    Kanenobu, Taizo

    2014-01-01

    An $\\SH(3)$-move is an unknotting operation on oriented knots introduced by Hoste, Nakanishi and Taniyama. We consider some relationships to other local moves such as a band surgery, $\\Gamma_{0}$-move, and $\\Delta$-move, and give some criteria for estimating the $\\SH(3)$-unknotting number using the Jones, HOMFLYPT, Q polynomials. We also show a table of $\\SH(3)$-unknotting numbers for knots with up to 9 crossings.

  14. SH(3)-MOVE AND OTHER LOCAL MOVES ON KNOTS

    OpenAIRE

    Kanenobu, Taizo

    2014-01-01

    An SH(3)-move is an unknotting operation on oriented knots introduced by Hoste, Nakanishi and Taniyama. We consider some relationships to other local moves such as a band surgery, Γ_0-move, and Δ-move, and give some criteria for estimating the SH(3)-unknotting number using the Jones, HOMFLYPT, Q polynomials. We also show a table of SH(3)-unknotting numbers for knots with up to 9 crossings.

  15. PREFACE: Ocean and climate changes in polar and sub-polar environments: proceedings from the 2010 IODP-Canada/ECORD summer school

    Science.gov (United States)

    St-Onge, Guillaume; Veiga-Pires, Cristina; Solignac, Sandrine

    2011-05-01

    IODP logoECORD logo The European Consortium for Ocean Drilling Program (ECORD), the Canadian Consortium for Ocean Drilling (CCOD), the Network of the Universités du Québec (UQ), the Université du Québec à Montréal (UQAM) and GEOTOP sponsored, in 2010, a summer school entitled 'Ocean and climate changes in polar and sub-polar environments'. This summer school took place from 27 June to 12 July in Rimouski, Québec city and Montréal (Quebec, Canada) and was attended by nineteen students and postdoctoral fellows from seven countries: Canada, France, Germany, UK, Serbia, Portugal and the USA. Lectures, hands-on laboratory exercises and laboratory visits were conducted at the Institut des Sciences de la Mer de Rimouski (ISMER), Institut National de la Recherche Scientifique - Centre Eau Terre Environnement (INRS-ETE) and UQAM, in addition to two field trips and a short geological and geophysical cruise on board the R/V Coriolis II in the St Lawrence Estuary and Saguenay Fjord. During the summer school, more than twenty researchers gave lectures on the use of several paleoceanographic and geophysical techniques to reconstruct ocean and climate changes in polar and sub-polar environments. Some of these lectures are presented as short review papers in this volume. They are intended to portray a brief, but state-of-the-art overview of an array of techniques applied to Arctic and sub-Arctic environments, as well as the geological background information needed by the summer school participants to put the scientific expedition and fieldwork into context. The volume begins with a view on the great challenges and key issues to be addressed in the Arctic Ocean (Stein) in the forthcoming years and is followed by a review (O'Regan) on Late Cenozoic paleoceanography of the Central Arctic. The two subsequent papers (St-Onge et al and de Vernal et al) deal with the oceanographic, paleoceanographic and geological context of the Saguenay Fjord, and St Lawrence Estuary and Gulf

  16. CERN Pension Fund move

    CERN Document Server

    HR Department

    2007-01-01

    The CERN Pension Fund has moved to new offices at the 5th floor of Building 5. The Benefits Service of the Fund will henceforth receive you in the offices: 5-5-017 - 5-5-021 - 5-5-023. We remind you that the office hours are: Tuesday/Wednesday/Thursday from 10 am to 12 am and from 3 pm to 5 pm. The Fund would like to take this opportunity to warmly thank all the persons involved in the Removal.

  17. Sense of moving

    DEFF Research Database (Denmark)

    2017-01-01

    In this chapter, we assume the existence of a sense of “movement activity” that arises when a person actively moves a body part. This sense is usually supposed to be part of sense of agency (SoA). The purpose of the chapter is to determine whether the already existing experimental paradigms can...... be used to study the sense of movement activity, i.e., the part of SoA related to actual movement. The bulk of the chapter is an argument to the effect that standard paradigms are ill equipped to study the sense of movement activity....

  18. Moving in Circles

    DEFF Research Database (Denmark)

    Simonsen, Gunvor

    2008-01-01

    The article examines the development of African diaspora history during the last fifty years. It outlines the move from a focus on African survivals to a focus on deep rooted cultural principles and back again to a revived interest in concrete cultural transfers from Africa to the Americas....... This circular movement can be explained by a combination of elements characterizing African Atlantic and black Atlantic history. Among them is a lack of attention to questions of periodisation and change. Likewise, it has proven difficult to conceptualize Africa and America at one and the same time...

  19. Modelling of the crystallization front – particles interactions in ZnAl/(SiCp composites

    Directory of Open Access Journals (Sweden)

    M. Szucki

    2015-04-01

    Full Text Available The presented work focuses on solid particle interactions with the moving crystallization front during a solidification of the metal matrix composite. The current analyses were made for silicon carbide particles and ZnAl alloy with different additions of aluminium. It was found, that the chemical composition of the metal matrix influences the behaviour of SiC particles. At the same time calculations of the forces acting on a single particle near the crystallization front were performed. For each alloy type the critical conditions that determine whether particle will be absorbed or pushed, were specified.

  20. The light-front vacuum and dynamics

    OpenAIRE

    Polyzou, W. N.

    2004-01-01

    I give a quantum theoretical description of kinematically invariant vacuua on the algebra of free fields restricted to a light front and discuss the relation between the light-front Hamiltonian, P-, the vacuum, and Poincare invariance. This provides a quantum theoretical description of zero modes.

  1. Propulsive force in front crawl swimming

    NARCIS (Netherlands)

    Berger, M.A.M.; de Groot, G.; Hollander, A.P.

    1999-01-01

    To evaluate the propulsive forces in front crawl arm swimming, derived from a three-dimensional kinematic analysis, these values were compared with mean drag forces. The propulsive forces during front crawl swimming using the arms only were calculated using three-dimensional kinematic analysis

  2. Through the EU's Back and Front Doors

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca

    2015-01-01

    Through the EU's front- and backdoors: The selective Danish and Norwegian approaches in the Area of Freedom, Security and Justice Rebecca Adler-Nissen......Through the EU's front- and backdoors: The selective Danish and Norwegian approaches in the Area of Freedom, Security and Justice Rebecca Adler-Nissen...

  3. Coping on the Front-line

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum; Lønsmann, Dorte

    This article investigates how front-line employees respond to English language policies implemented by the management of three multinational corporations (MNCs) headquartered in Scandinavia. Based on interview and document data the article examines the ways in which front-line employees cross lan...

  4. Light front quantum chromodynamics: Towards phenomenology

    Indian Academy of Sciences (India)

    We briefly review the application of light front QCD to inclusive deep inelastic scattering. Keywords. Light front dynamics .... longitudinal gluon structure function and to a new sum rule. К. dmFД/m = 4M¾/Q¾. , which ... For the transversely polarized structure function g¾, if the twist three contributions are ignored, one gets an ...

  5. Thermal Fronts Atlas of Canadian Coastal Waters

    NARCIS (Netherlands)

    Cyr, F.; Larouche, P.

    2015-01-01

    Oceanic fronts are often associated with enhanced biological activity. Depending on their generation mechanism, they are often linked to specific geographical areas. Here we use 25 years of high-resolution satellite sea surface temperature (SST) daily images to generate maps of SST fronts over

  6. End-Users, Front Ends and Librarians.

    Science.gov (United States)

    Bourne, Donna E.

    1989-01-01

    The increase in end-user searching, the advantages and limitations of front ends, and the role of the librarian in end-user searching are discussed. It is argued that librarians need to recognize that front ends can be of benefit to themselves and patrons, and to assume the role of advisors and educators for end-users. (37 references) (CLB)

  7. Turbulence spectra measured during fire front passage

    Science.gov (United States)

    Daisuke Seto; Craig B. Clements; Warren E. Heilman

    2013-01-01

    Four field experiments were conducted over various fuel and terrain to investigate turbulence generation during the passage of wildland fire fronts. Our results indicate an increase in horizontal mean winds and friction velocity, horizontal and vertical velocity variances as well as a decreased degree of anisotropy in TKE during fire front passage (FFP) due to fire-...

  8. Ready, set, move!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    This year, the CERN Medical Service is launching a new public health campaign. Advertised by the catchphrase “Move! & Eat Better”, the particular aim of the campaign is to encourage people at CERN to take more regular exercise, of whatever kind.   The CERN annual relay race is scheduled on 24 May this year. The CERN Medical Service will officially launch its “Move! & Eat Better” campaign at this popular sporting event. “We shall be on hand on the day of the race to strongly advocate regular physical activity,” explains Rachid Belkheir, one of the Medical Service doctors. "We really want to pitch our campaign and answer any questions people may have. Above all we want to set an example. So we are going to walk the same circuit as the runners to underline to people that they can easily incorporate movement into their daily routine.” An underlying concern has prompted this campaign: during their first few year...

  9. Indexing Moving Points

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

    2003-01-01

    We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present...... an indexing structure that, for any given constant >0, uses O(N/B) disk blocks and answers a query in O((N/B)1/2+ +K/B) I/Os, where B is the block size. It can also report all the points of S that lie inside R during a given time interval. A point can be inserted or deleted, or the trajectory of a point can...... be changed, in O(logB2 N) I/Os. Next, we present a general approach that improves the query time if the queries arrive in chronological order, by allowing the index to evolve over time. We obtain a tradeoff between the query time and the number of times the index needs to be updated as the points move. We...

  10. Coherent structures for front propagation in fluids

    Science.gov (United States)

    Mitchell, Kevin; Mahoney, John

    2014-03-01

    Our goal is to characterize the nature of reacting flows by identifying important ``coherent'' structures. We follow the recent work by Haller, Beron-Vera, and Farazmand which formalized the notion of lagrangian coherent structures (LCSs) in fluid flows. In this theory, LCSs were derived from the Cauchy-Green strain tensor. We adapt this perspective to analogously define coherent structures in reacting flows. By this we mean a fluid flow with a reaction front propagating through it such that the propagation does not affect the underlying flow. A reaction front might be chemical (Belousov-Zhabotinsky, flame front, etc.) or some other type of front (electromagnetic, acoustic, etc.). While the recently developed theory of burning invariant manifolds (BIMs) describes barriers to front propagation in time-periodic flows, this current work provides an important complement by extending to the aperiodic setting. Funded by NSF Grant CMMI-1201236.

  11. Alternatives to the Moving Average

    Science.gov (United States)

    Paul C. van Deusen

    2001-01-01

    There are many possible estimators that could be used with annual inventory data. The 5-year moving average has been selected as a default estimator to provide initial results for states having available annual inventory data. User objectives for these estimates are discussed. The characteristics of a moving average are outlined. It is shown that moving average...

  12. What moves us?

    DEFF Research Database (Denmark)

    2015-01-01

    Katalog til udstillingen på Museum Jorn - What moves us? Le Corbusier & Asger Jorn - 12. sept. - 13. dec. 2015. Kataloget undersøger Le Corbusiers skifte fra en rationelt funderet tilgang til arkitekturen til en poetisk, materialistisk tilgang i efterkrigstiden. Den viser hans indflydelse på den...... yngre Asger Jorn og beskriver danskerens første beundring, som sidenhen forvandledes til skarp kritik. Kataloget, som er rigt illustreret med billeder af Le Corbusiers og Asger Jorns kunst og arkitektur, indeholder også genoptryk af originale tekster, samt bidrag i ord og billeder fra fremtrædende...... eksperter. Kataloget indeholder en række artikler af internationale skribenter under flg. overskrifter: Le Corbusier - kunstnerarkitekten i efterkrigstidens Europa Le Corbusier og Asger Jorn - David mod Goliat Gensyn med Le Corbusier - spor i dansk arkitektur og byrum...

  13. Move! Eat better: news

    CERN Multimedia

    2013-01-01

    Are you curious to know whether you’re doing enough daily exercise…? Test yourself with a pedometer!   Through the Move! Eat better campaign, launched in May 2012, the CERN medical service is aiming to improve the health of members of the personnel by encouraging them to prioritise physical activity in conjunction with a balanced diet. Various successful activities have already taken place: relay race/Nordic walk, Bike2work, Zumba and fitness workshops, two conferences (“Physical activity for health” and “Good nutrition every day”), events in the restaurants, as well as posters and a website. Although everyone has got the message from our various communications that physical activity is good for your health, there is still a relevant question being asked: “What is the minimum amount of exercise recommended?” 10,000 steps per day is the ideal figure, which has been demonstrated as beneficial by scientific studies ...

  14. Moving Beyond Outsourcing

    DEFF Research Database (Denmark)

    Rai, Sudhanshu

    In this article I discuss the Indian outsourcing phenomena and ask the question now what? Using data from the Euro-India project I demonstrate that a small but significant part of the Indian IT entities are moving beyond outsourcing, to co-creation where Innovation and the desire to create new...... markets is the key driver. This does not imply that outsourcing will disappear but it does mean that firms will engage in globalization using innovative mix of business models and technical platforms. We discuss the implication of this slow transformation to co-creation of innovation for the global...... outsourcing industry. The key thesis of this paper is to discuss co-creation as a form of innovation and how such a form of innovation is likely to bring Indian companies rich dividends....

  15. Mechanics of moving materials

    CERN Document Server

    Banichuk, Nikolay; Neittaanmäki, Pekka; Saksa, Tytti; Tuovinen, Tero

    2014-01-01

    This book deals with theoretical aspects of modelling the mechanical behaviour of manufacturing, processing, transportation or other systems in which the processed or supporting material is travelling through the system. Examples of such applications include paper making, transmission cables, band saws, printing presses, manufacturing of plastic films and sheets, and extrusion of aluminium foil, textiles and other materials.   The work focuses on out-of-plane dynamics and stability analysis for isotropic and orthotropic travelling elastic and viscoelastic materials, with and without fluid-structure interaction, using analytical and semi-analytical approaches.  Also topics such as fracturing and fatigue are discussed in the context of moving materials. The last part of the book deals with optimization problems involving physical constraints arising from the stability and fatigue analyses, including uncertainties in the parameters.   The book is intended for researchers and specialists in the field, providin...

  16. Spin coating of non-Newtonian fluids with a moving front

    Science.gov (United States)

    Charpin, J. P. F.; Lombe, M.; Myers, T. G.

    2007-07-01

    We investigate axisymmetric spin coating of power law and Ellis fluids. The flow is driven by centrifugal force, gravity and surface tension. For power law and Ellis models a single equation for the fluid film height is obtained. For a Newtonian fluid the flux only involves linear derivative terms which allows the flux to be easily split for a numerical scheme. For power law and Ellis models the derivatives appear as nonlinear terms. To overcome this we develop an alternative numerical scheme to solve for the film height. Neglecting surface tension and gravity the power law model shows a central spike which is reduced by the introduction of surface tension and gravity. In certain cases the shear thinning power law model predicts slower spreading than the Newtonian model. The Ellis fluid shows no central spike, even for zero surface tension and the film always spreads further than the Newtonian fluid.

  17. Io in Front of Jupiter

    Science.gov (United States)

    2000-01-01

    Jupiter's four largest satellites, including Io, the golden ornament in front of Jupiter in this image from NASA's Cassini spacecraft, have fascinated Earthlings ever since Galileo Galilei discovered them in 1610 in one of his first astronomical uses of the telescope.Images from Cassini that will be released over the next several days capture each of the four Galilean satellites in their orbits around the giant planet.This true-color composite frame, made from narrow angle images taken on Dec. 12, 2000, captures Io and its shadow in transit against the disk of Jupiter. The distance of the spacecraft from Jupiter was 19.5 million kilometers (12.1 million miles). The image scale is 117 kilometers (73 miles) per pixel.The entire body of Io, about the size of Earth's Moon, is periodically flexed as it speeds around Jupiter and feels, as a result of its non-circular orbit, the periodically changing gravitational pull of the planet. The heat arising in Io's interior from this continual flexure makes it the most volcanically active body in the solar system, with more than 100 active volcanoes. The white and reddish colors on its surface are due to the presence of different sulfurous materials. The black areas are silicate rocks.Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  18. Relating precipitation to fronts at a sub-daily basis

    Science.gov (United States)

    Hénin, Riccardo; Ramos, Alexandre M.; Liberato, Margarida L. R.; Gouveia, Célia

    2017-04-01

    High impact events over Western Iberia include precipitation extremes that are cause for concern as they lead to flooding, landslides, extensive property damage and human casualties. These events are usually associated with low pressure systems over the North Atlantic moving eastward towards the European western coasts (Liberato and Trigo, 2014). A method to detect fronts and to associate amounts of precipitation to each front is tested, distinguishing between warm and cold fronts. The 6-hourly ERA-interim 1979-2012 reanalysis with 1°x1° horizontal resolution is used for the purpose. An objective front identification method (the Thermal Method described in Shemm et al., 2014) is applied to locate fronts all over the Northern Hemisphere considering the equivalent potential temperature as thermal parameter to use in the model. On the other hand, we settled a squared search box of tuneable dimension (from 2 to 10 degrees long) to look for a front in the neighbourhood of a grid point affected by precipitation. A sensitivity analysis is performed and the optimal dimension of the box is assessed in order to avoid over(under) estimation of precipitation. This is performed in the light of the variability and typical dynamics of warm/cold frontal systems in the Western Europe region. Afterwards, using the extreme event ranking over Iberia proposed by Ramos et al. (2014) the first ranked extreme events are selected in order to validate the method with specific case studies. Finally, climatological and trend maps of frontal activity are produced both on annual and seasonal scales. Trend maps show a decrease of frontal precipitation over north-western Europe and a slight increase over south-western Europe, mainly due to warm fronts. REFERENCES Liberato M.L.R. and R.M. Trigo (2014) Extreme precipitation events and related impacts in Western Iberia. Hydrology in a Changing World: Environmental and Human Dimensions. IAHS Red Book No 363, 171-176. ISSN: 0144-7815. Ramos A.M., R

  19. Blocking-resistant communication through domain fronting

    Directory of Open Access Journals (Sweden)

    Fifield David

    2015-06-01

    Full Text Available We describe “domain fronting,” a versatile censorship circumvention technique that hides the remote endpoint of a communication. Domain fronting works at the application layer, using HTTPS, to communicate with a forbidden host while appearing to communicate with some other host, permitted by the censor. The key idea is the use of different domain names at different layers of communication. One domain appears on the “outside” of an HTTPS request—in the DNS request and TLS Server Name Indication—while another domain appears on the “inside”—in the HTTP Host header, invisible to the censor under HTTPS encryption. A censor, unable to distinguish fronted and nonfronted traffic to a domain, must choose between allowing circumvention traffic and blocking the domain entirely, which results in expensive collateral damage. Domain fronting is easy to deploy and use and does not require special cooperation by network intermediaries. We identify a number of hard-to-block web services, such as content delivery networks, that support domain-fronted connections and are useful for censorship circumvention. Domain fronting, in various forms, is now a circumvention workhorse. We describe several months of deployment experience in the Tor, Lantern, and Psiphon circumvention systems, whose domain-fronting transports now connect thousands of users daily and transfer many terabytes per month.

  20. Passport to the Big Bang moves across the road

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    The ATLAS platform of the Passport to the Big Bang circuit has been relocated in front of the CERN Reception.   The ATLAS platform of the Passport to the Big Bang, outside the CERN Reception building. The Passport to the Big Bang platform of the ATLAS Experiment has been moved in front of the CERN Reception to make it more visible and accessible. It had to be dismantled and moved from its previous location in the garden of the Globe of Science and Innovation due to the major refurbishment work in progress on the Globe, and is now fully operational in its new location on the other side of the road, in the Main Reception car-park. The Passport to the Big Bang circuit, inaugurated in 2013, comprises ten platforms installed in front of ten CERN sites and aims to help local residents and visitors to the region understand CERN's research. Dedicated Passport to the Big Bang flyers, containing all necessary information and riddles for you to solve, are available at the CERN Rec...

  1. Ultrashort-pulse wave-front autocorrelation.

    Science.gov (United States)

    Grunwald, R; Neumann, U; Griebner, U; Reimann, K; Steinmeyer, G; Kebbel, V

    2003-12-01

    Combined spatially resolved collinear autocorrelation and Shack-Hartmann wave-front sensing of femtosecond laser pulses is demonstrated for the first time to our knowledge. The beam is divided into multiple nondiffracting subbeams by thin-film micro-optical arrays. With hybrid refractive-reflective silica/silver microaxicons, wave-front autocorrelation is performed in oblique-angle reflection. Simultaneous two-dimensional detection of local temporal structure and wave-front tilt of propagating few-cycle wave packets is demonstrated.

  2. Pressure transient method for front tracking

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.M.; Bodvarsson, G.S.

    1983-08-01

    A pressure transient technique for tracking the advance of cold water fronts during water flooding and goethermal injection operations has been developed. The technique is based on the concept that the steady state pressure buildup in the reservoir region inside the front can be calculated by a fluid skin factor. By analyzing successive pressure falloff tests, the advance of the front in the reservoir can be monitored. The validity of the methods is demonstrated by application to three numerically simulated data sets, a nonisothermal step-rate injection test, a series of pressure falloffs in a multilayered reservoir, and a series of pressure falloff tests in a water flooded oil reservoir.

  3. Frontón en Lezkairu

    OpenAIRE

    Legarra Arizaleta, Xabier

    2010-01-01

    El objetivo del proyecto es el diseño, cálculo y presupuestado de un frontón cubierto de 36 metros de longitud, con sus correspondientes gradas, instalaciones y aparcamientos en el nuevo barrio pamplonés de Lezkairu. El frontón propuesto está destinado a un uso público debido a la gran demanda que nace en relación a la pelota, y sus diferentes modalidades así como la carencia de más infraestructuras de este tipo. Cabe destacar que las características y medidas del frontón lo ...

  4. Apparatus and method for phase fronts based on superluminal polarization current

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, John [Los Alamos, NM; Ardavan, Houshang [Cambridge, GB; Ardavan, Arzhang [Cambridge, GB

    2012-02-28

    An apparatus and method for a radiation source involving phase fronts emanating from an accelerated, oscillating polarization current whose distribution pattern moves superluminally (that is, faster than light in vacuo). Theoretical predictions and experimental measurements using an existing prototype superluminal source show that the phase fronts from such a source can be made to be very complex. Consequently, it will be very difficult for an aircraft imaged by such a radiation to detect where this radiation has come from. Moreover, the complexity of the phase fronts makes it almost impossible for electronics on an aircraft to synthesize a rogue reflection. A simple directional antenna and timing system should, on the other hand, be sufficient for the radar operators to locate the aircraft, given knowledge of their own source's speed and modulation pattern.

  5. Imaging Slow Slip Fronts in Cascadia With High-Precision Tremor Locations

    Science.gov (United States)

    Rubin, A. M.; Armbruster, J. G.

    2012-12-01

    We use the method of Armbruster and Kim [AGU 2010] to obtain tremor locations using 4-second windows, focusing on a few spots beneath southern Vancouver Island activated by slow slip events from 2003 to 2005. The method compares horizontal-component waveforms (not envelopes) at 3 stations separated by 10-20 km. From local earthquakes "caught" by the detector it appears that the coherent signal consists of the direct S arrival but not the S coda. Using 150-s windows, Armbruster and Kim found "wispy" sources of tremor that in some regions were reproducible between the 2003, 2004, and 2005 events to within 1 km. In time, their tremor locations trace out quasi-linear trajectories on the fault surface that migrate tens of times faster than the main front, as has been reported elsewhere [e.g., Ghosh et al., 2010; Vidale et al., AGU 2011]. By moving to 4-s windows, we find that these long-time-window locations very often represent the spatial "average" of secondary fronts behind the main front. These secondary fronts tend to (a) start within about 1 km of the main tremor front and propagate back along strike, akin to the "rapid tremor reversals" of Houston et al. [2011] but on a smaller scale (5 km rather than 50); (b) less commonly do the reverse, ending at the main front; or (c) propagate up- or down-dip at or within 1-2 kilometers of the main front. Rare events propagate in other directions. The fronts that move along strike can be as narrow as 1 km in the propagation direction but can exceed 5 km in the orthogonal direction. Those that propagate along dip are typically also narrow (~ 1 km) in the strike direction; if they are even narrower in the propagation direction this is below our resolution. Characteristic propagation speeds are 10 km/hr along strike and several times faster along dip. For those along-dip migrations that occur at the main front, the larger propagation speed is plausibly an "apparent" velocity as the main front intersects an along-dip alignment

  6. Role of moving planes and moving spheres following Dupin cyclides

    KAUST Repository

    Jia, Xiaohong

    2014-03-01

    We provide explicit representations of three moving planes that form a μ-basis for a standard Dupin cyclide. We also show how to compute μ-bases for Dupin cyclides in general position and orientation from their implicit equations. In addition, we describe the role of moving planes and moving spheres in bridging between the implicit and rational parametric representations of these cyclides. © 2014 Elsevier B.V.

  7. LBNL delivers front end of SNS

    CERN Document Server

    Keller, R

    2002-01-01

    After four years of construction, the linear accelerator injector that will form the front end of the US SNS has been commissioned at LBNL. Fulfilling all its major design requirements and performing reliably, the system was shipped by July.

  8. Perturbative High Harmonic Wave Front Control.

    Science.gov (United States)

    Li, Zhengyan; Brown, Graham; Ko, Dong Hyuk; Kong, Fanqi; Arissian, Ladan; Corkum, P B

    2017-01-20

    We pattern the wave front of a high harmonic beam by intersecting the intense driving laser pulse that generates the high harmonic with a weak control pulse. To illustrate the potential of wave-front control, we imprint a Fresnel zone plate pattern on a harmonic beam, causing the harmonics to focus and defocus. The quality of the focus that we achieve is measured using the spectral wave-front optical reconstruction by diffraction method. We will show that it is possible to enhance the peak intensity by orders of magnitude without a physical optical element in the path of the extreme ultraviolet (XUV) beam. Through perturbative wave-front control, XUV beams can be created with a flexibility approaching what technology allows for visible and infrared light.

  9. Light front distribution of the chiral condensate

    National Research Council Canada - National Science Library

    Chang, Lei; Roberts, Craig D; Schmidt, Sebastian M

    2013-01-01

    The pseudoscalar projection of the pionE1/4s Poincare-covariant Bethe-Salpeter amplitude onto the light-front may be understood to provide the probability distribution of the chiral condensate within the pion...

  10. Instability of planar detonation front in energetic materials

    Science.gov (United States)

    Budzevich, Mikalai; Zhakhovsky, Vasily; Landerville, Aaron; White, Carter; Oleynik, Ivan

    2012-02-01

    Detonation wave propagation in solid energetic materials (EMs), as described by the standard AB model, was studied using a novel moving window molecular dynamics (MW-MD) technique. Parameters of the AB model were modified to investigate the mechanisms of detonation propagation in EMs as a function of the activation barrier for the chemical reaction AB+B -> A+BB + 3 eV. For barriers below 0.2 eV, the detonation front structure remained planar irregardless of the cross-section of the sample. For higher activation barriers, the one-dimensional planar detonation evolves into a cellular detonation upon increase of one of the transverse dimensions of the sample. The cellular detonation transforms into a stable three-dimensional turbulent-like detonation upon simultaneous increase of both transverse dimensions of the sample. These various instabilities of the planar detonation front in solid EMs observed in our MW-MD simulations mirror the major regimes of gas-phase detonation, thus confirming the universal nature of detonation phenomena.

  11. Spontaneous Wave Generation from Submesoscale Fronts and Filaments

    Science.gov (United States)

    Shakespeare, C. J.; Hogg, A.

    2016-02-01

    Submesoscale features such as eddies, fronts, jets and filaments can be significant sources of spontaneous wave generation at the ocean surface. Unlike near-inertial waves forced by winds, these spontaneous waves are typically of higher frequency and can propagate through the thermocline, whereupon they break and drive mixing in the ocean interior. Here we investigate the spontaneous generation, propagation and subsequent breaking of these waves using a combination of theory and submesoscale resolving numerical models. The mechanism of generation is nearly identical to that of lee waves where flow is deflected over a rigid obstacle on the sea floor. Here, very sharp fronts and filaments of order 100m width moving in the submesoscale surface flow generate "surface lee waves" by presenting an obstacle to the surrounding stratified fluid. Using our numerical model we quantify the net downward wave energy flux from the surface, and where it is dissipated in the water column. Our results suggest an alternative to the classical paradigm where the energy associated with mixing in the ocean interior is sourced from bottom-generated lee waves.

  12. Deep reduced PEDOT films support electrochemical applications: Biomimetic color front.

    Directory of Open Access Journals (Sweden)

    Toribio Fernandez OTERO

    2015-02-01

    Full Text Available Most of the literature accepts, despite many controversial results, that during oxidation/reduction films of conducting polymers move from electronic conductors to insulators. Thus, engineers and device’s designers are forced to use metallic supports to reoxidize the material for reversible device work. Electrochromic front experiments appear as main visual support of the claimed insulating nature of reduced conducting polymers. Here we present a different design of the biomimetic electrochromic front that corroborates the electronic and ionic conducting nature of deep reduced films. The direct contact PEDOT metal/electrolyte and film/electrolyte was prevented from electrolyte contact until 1cm far from the metal contact with protecting Parafilm®. The deep reduced PEDOT film supports the flow of high currents promoting reaction induced electrochromic color changes beginning 1 cm far from the metal-polymer electrical contact and advancing, through the reduced film, towards the metal contact. Reverse color changes during oxidation/reduction always are initiated at the film/electrolyte contact advancing, under the protecting film, towards the film/metal contact. Both reduced and oxidized states of the film demonstrate electronic and ionic conductivities high enough to be used for electronic applications or, as self-supported electrodes, for electrochemical devices. The electrochemically stimulated conformational relaxation (ESCR model explains those results.

  13. Move and eat better

    CERN Multimedia

    2012-01-01

    CERN has many traditions, but in a week that’s seen the launch of the Medical Service’s  ‘Move & eat better’ campaign, it’s refreshing to note that among the oldest is a sporting one.  The CERN relay race dates back to 15 October 1971 when 21 pioneering teams set off to pound the pavements of CERN. Back then, the Focus users group came in first with a time of 12 minutes and 42 seconds. Today’s route is slightly different, and the number of teams has risen to over 100, with a new category of Nordic Walking introduced, as part of the campaign, for the first time.   The relay has provided some memorable events, and perhaps one of the longest-standing records in the history of sport, with the UA1 strollers’ 10 minutes and 13 seconds unbeaten for thirty years. In the women’s category, the UN Gazelles set the fastest time of 13 minutes and 16 seconds in 1996, while in the veterans category, you wi...

  14. ATLAS starts moving in

    CERN Multimedia

    Della Mussia, S

    2004-01-01

    The first large active detector component was lowered into the ATLAS cavern on 1st March. It consisted of the 8 modules forming the lower part of the central barrel of the tile hadronic calorimeter. The work of assembling the barrel, which comprises 64 modules, started the following day. Two road trailers each with 64 wheels, positioned side by side. This was the solution chosen to transport the lower part of the central barrel of ATLAS' tile hadronic calorimeter from Building 185 to the PX16 shaft at Point 1 (see Figure 1). The transportation, and then the installation of the component in the experimental cavern, which took place over three days were, to say the least, rather spectacular. On 25 February, the component, consisting of eight 6-metre modules, was loaded on to the trailers. The segment of the barrel was transported on a steel support so that it wouldn't move an inch during the journey. On 26 February, once all the necessary safety checks had been carried out, the convoy was able to leave Buildi...

  15. Luxury consumption moves East

    DEFF Research Database (Denmark)

    Khan, Omera

    2015-01-01

    Purpose – The literature contains relatively little prescriptive guidance for establishing supply chain strategies in the luxury fashion marketplace. The focus has been on fashion rather than luxury fashion and the purpose of this paper is to identify and explore the critical supply chain success...... novel insights to transformations in global supply chain strategy as luxury consumption is moving towards the east, which creates new challenges and demands for European manufacturers to respond, to sustaining a competitive advantage.......Purpose – The literature contains relatively little prescriptive guidance for establishing supply chain strategies in the luxury fashion marketplace. The focus has been on fashion rather than luxury fashion and the purpose of this paper is to identify and explore the critical supply chain success...... success factors to consider when developing a business strategy to enter the Chinese luxury fashion marketplace. Practical implications – The findings could guide managers that are developing a business case for entering the Chinese luxury fashion marketplace. Originality/value – This case study provides...

  16. Reaction-diffusion fronts under stochastic advection

    CERN Document Server

    Martí, A C; Sancho, J M

    1997-01-01

    We study front propagation in stirred media using a simplified modelization of the turbulent flow. Computer simulations reveal the existence of the two limiting propagation modes observed in recent experiments with liquid phase isothermal reactions. These two modes respectively correspond to a wrinkled although sharp propagating interface and to a broadened one. Specific laws relative to the enhancement of the front velocity in each regime are confirmed by our simulations.

  17. An efficient methodology for assessing attention to and effect of nutrition information displayed front-of-pack

    NARCIS (Netherlands)

    Bialkova, S.E.; Trijp, van H.C.M.

    2011-01-01

    A methodology for assessing attention to and effect of nutrition information displayed front-of-pack is presented. The methodology is based on an integration of the visual search paradigm, the choice paradigm and eye-tracking measures, and moves beyond reliance on self-report measures for attention

  18. Dynamics of Moving bodies

    Science.gov (United States)

    Ghosh, Pranoy

    2017-01-01

    ``A problem with defining force as rate of change of linear momentum'': Let us consider a body of mass m, moving with velocity u initially, in the next time interval it is acted by a force in the direction of motion, and at instant t + its mass is M and velocity v. F .t =Mv-mu or,v = m/M.u +F/M.t or,v =B.u +A.t where A =F/M,B =m/M. So other eqn of motion are: dS =vdt or dS =(B.u +A.t)dt or S =B.u.t +A/2.t2 Andv2 =B2 u2 +2A .B .u .t +A2 t2 or,v2 =B2 u2 +2A.S However, defining acceleration as rate of change of velocity, we have established an identity v =u +a.t which is independent of choice of v, u. M>>m, B is very small, product B.u or its higher power always tend to be negligible, even in cases when u is finitely large.In cases v ->c,F,M -> ∞ , thus A becomes indeterminate.There is inconvenience as A, B are not predetermined and are functions of u, v and thus the definition goes in circle. Hence we conclude, our hypothesis that force =rate of change of linear momentum is not sufficient; we would now find trial solutions to define force in most convenient way.

  19. Westward advance of the deformation front and evolution of submarine canyons offshore of southwestern Taiwan

    Science.gov (United States)

    Han, Wei-Chung; Liu, Char-Shine; Chi, Wu-Cheng; Chen, Liwen; Lin, Che-Chuan; Chen, Song-Chuen

    2017-11-01

    This study analyzes both 2D and 3D seismic images around the Palm Ridge area offshore of southwestern Taiwan to understand how the deformation front shifted westward and how tectonic activities interact with submarine canyon paths in the transition area between the active and passive margins. Palm Ridge is a submarine ridge that developed on the passive China continental margin by down-dip erosion of several tributaries of Penghu Canyon; it extends eastward across the deformation front into the submarine Taiwan accretionary wedge. The presence of proto-thrusts that are located west of the frontal thrust implies that the compressional stress field has advanced westward due to the convergence of the Philippine Sea Plate and Eurasian Plate. Since the deformation front is defined as the location of the most frontal contractional structure, no significant contractional structure should appear west of it. We thus suggest moving the location of the previously mapped deformation front farther west to where the westernmost proto-thrust lies. High-resolution seismic and bathymetric data reveal that the directions of the paleo-submarine canyons run transverse to the present slope dip, while the present submarine canyons head down slope in the study area. We propose that this might be the result of the westward migration of the deformation front that changed the paleo-bathymetry and thus the canyon path directions. The interactions of down-slope processes and active tectonics control the canyon paths in our study area.

  20. QCD and Light-Front Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; de Teramond, Guy F.; /SLAC /Southern Denmark U., CP3-Origins /Costa Rica U.

    2011-01-10

    AdS/QCD, the correspondence between theories in a dilaton-modified five-dimensional anti-de Sitter space and confining field theories in physical space-time, provides a remarkable semiclassical model for hadron physics. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The result is a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. The hadron eigenstates generally have components with different orbital angular momentum; e.g., the proton eigenstate in AdS/QCD with massless quarks has L = 0 and L = 1 light-front Fock components with equal probability. Higher Fock states with extra quark-anti quark pairs also arise. The soft-wall model also predicts the form of the nonperturbative effective coupling and its {beta}-function. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method to systematically include QCD interaction terms. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. A method for computing the hadronization of quark and gluon jets at the amplitude level is outlined.

  1. Pareto fronts in clinical practice for pinnacle.

    Science.gov (United States)

    Janssen, Tomas; van Kesteren, Zdenko; Franssen, Gijs; Damen, Eugène; van Vliet, Corine

    2013-03-01

    Our aim was to develop a framework to objectively perform treatment planning studies using Pareto fronts. The Pareto front represents all optimal possible tradeoffs among several conflicting criteria and is an ideal tool with which to study the possibilities of a given treatment technique. The framework should require minimal user interaction and should resemble and be applicable to daily clinical practice. To generate the Pareto fronts, we used the native scripting language of Pinnacle(3) (Philips Healthcare, Andover, MA). The framework generates thousands of plans automatically from which the Pareto front is generated. As an example, the framework is applied to compare intensity modulated radiation therapy (IMRT) with volumetric modulated arc therapy (VMAT) for prostate cancer patients. For each patient and each technique, 3000 plans are generated, resulting in a total of 60,000 plans. The comparison is based on 5-dimensional Pareto fronts. Generating 3000 plans for 10 patients in parallel requires on average 96 h for IMRT and 483 hours for VMAT. Using VMAT, compared to IMRT, the maximum dose of the boost PTV was reduced by 0.4 Gy (P=.074), the mean dose in the anal sphincter by 1.6 Gy (P=.055), the conformity index of the 95% isodose (CI(95%)) by 0.02 (P=.005), and the rectal wall V(65 Gy) by 1.1% (P=.008). We showed the feasibility of automatically generating Pareto fronts with Pinnacle(3). Pareto fronts provide a valuable tool for performing objective comparative treatment planning studies. We compared VMAT with IMRT in prostate patients and found VMAT had a dosimetric advantage over IMRT. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Light-Front Holography and the Light-Front Schrodinger Equation

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; de Teramond, Guy

    2012-08-15

    One of the most important nonperturbative methods for solving QCD is quantization at fixed light-front time {tau} = t+z=c - Dirac's 'Front Form'. The eigenvalues of the light-front QCD Hamiltonian predict the hadron spectrum and the eigensolutions provide the light-front wavefunctions which describe hadron structure. More generally, we show that the valence Fock-state wavefunctions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schrodinger equation, with an effective confining potential U which systematically incorporates the effects of higher quark and gluon Fock states. We outline a method for computing the required potential from first principles in QCD. The holographic mapping of gravity in AdS space to QCD, quantized at fixed light-front time, yields the same light front Schrodinger equation; in fact, the soft-wall AdS/QCD approach provides a model for the light-front potential which is color-confining and reproduces well the light-hadron spectrum. One also derives via light-front holography a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The elastic and transition form factors of the pion and the nucleons are found to be well described in this framework. The light-front AdS/QCD holographic approach thus gives a frame-independent first approximation of the color-confining dynamics, spectroscopy, and excitation spectra of relativistic light-quark bound states in QCD.

  3. Congestion and residential moving behaviour

    DEFF Research Database (Denmark)

    Larsen, Morten Marott; Pilegaard, Ninette; Van Ommeren, Jos

    2008-01-01

    we study how congestion and residential moving behaviour are interrelated, using a two-region job search model. Workers choose between interregional commuting and residential moving, in order to live closer to their place of work. This choice affects the external costs of commuting, due to conges...

  4. Radiation by moving charges

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-04-15

    It is generally accepted that in order to describe the dynamics of relativistic particles in the laboratory (lab) frame it is sufficient to take into account the relativistic dependence of the particle momenta on the velocity. This solution of the dynamics problem in the lab frame makes no reference to Lorentz transformations. For this reason they are not discussed in particle tracking calculations in accelerator and plasma physics. It is generally believed that the electrodynamics problem can be treated within the same ''single inertial frame'' description without reference to Lorentz transformations. In particular, in order to evaluate radiation fields arising from charged particles in motion we need to know their velocities and positions as a function of the lab frame time t. The relativistic motion of a particle in the lab frame is described by Newton's second law ''corrected'' for the relativistic dependence of momentum on velocity. It is assumed in all standard derivations that one can perform identification of the trajectories in the source part of the usual Maxwell's equations with the trajectories vector x(t) measured (or calculated by using the corrected Newton's second law) in the lab frame. This way of coupling fields and particles is considered since more than a century as the relativistically correct procedure.We argue that this procedure needs to be changed, and we demonstrate the following, completely counterintuitive statement: the results of conventional theory of radiation by relativistically moving charges are not consistent with the principle of relativity. In order to find the trajectory of a particle in the lab frame consistent with the usual Maxwell's equations, one needs to solve the dynamic equation inmanifestly covariant form by using the coordinate-independent proper time τ to parameterize the particle world-line in space-time. We show that there is a difference between &apos

  5. Analytical and numerical modeling of front propagation and interaction of fronts in nonlinear thermoviscous

    DEFF Research Database (Denmark)

    Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

    2008-01-01

    , the model equation considered here is capable to describe waves propagating in opposite directions. Owing to the Hamiltonian structure of the proposed model equation, the front solution is in agreement with the classical Rankine Hugoniot relations. The exact front solution propagates at supersonic speed...

  6. On Front Slope Stability of Berm Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, Hans F.

    2013-01-01

    The short communication presents application of the conventional Van der Meer stability formula for low-crested breakwaters for the prediction of front slope erosion of statically stable berm breakwaters with relatively high berms. The method is verified (Burcharth, 2008) by comparison...... test results including tests presented in Sigurdarson and Van der Meer (2011) are discussed. A proposal is presented for performance of new model tests with the purpose of developing more accurate formulae for the prediction of front slope erosion as a function of front slope, relative berm height......, relative berm width, method of armour stone placement, and hydraulic parameters. The formulae should cover the structure range from statically stable berm breakwaters to conventional double layer armoured breakwaters....

  7. Optimal back-to-front airplane boarding.

    Science.gov (United States)

    Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

    2013-06-01

    The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

  8. Solidification cells at low velocity: The moving symmetric model

    Energy Technology Data Exchange (ETDEWEB)

    Karma, A.

    1986-11-01

    This paper is the first in a series of theoretical studies of singular cells in the small solute Peclet number limit (P..-->..0) of two-dimensional models of directional solidification. In this limit solute diffusion in the frame of the moving front is nearly Laplacian in which case solidification cells and Saffman-Taylor fingers are closely related. Here Langer's moving symmetric model in the absence of temperature gradient (which also describes solidification in a channel of width lambda at unit undercooling) is considered. A boundary integral equation describing steady-state cells is derived and it is shown that in the P..-->..0 limit this equation can be expressed in terms of a single dimensionless parameter sigmaproportionald/sub 0/l/lambda/sup 2/. The endpoint singularity is studied analytically and physically admissible solutions are found numerically to only exist for a discrete set of values of sigma. The small P dependence of sigma is also examined.

  9. Cosmic Pressure Fronts Mapped by Chandra

    Science.gov (United States)

    2000-03-01

    A colossal cosmic "weather system" produced by the collision of two giant clusters of galaxies has been imaged by NASA's Chandra X-ray Observatory. For the first time, the pressure fronts in the system can be traced in detail, and they show a bright, but relatively cool 50 million degree Celsius central region embedded in large elongated cloud of 70 million degree Celsius gas, all of which is roiling in a faint "atmosphere"of 100 million degree Celsius gas. "We can compare this to an intergalactic cold front," said Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. and leader of the international team involved in the analysis of the observations. "A major difference is that in this case, cold means 70 million degree Celsius." The gas clouds are in the core of a galaxy cluster known as Abell 2142. The cluster is six million light years across and contains hundreds of galaxies and enough gas to make a thousand more. It is one of the most massive objects in the universe. Galaxy clusters grow to vast sizes as smaller clusters are pulled inward under the influence of gravity. They collide and merge over the course of billions of years, releasing tremendous amounts of energy that heats the cluster gas to 100 million degrees Celsius. The Chandra data provides the first detailed look at the late stages of this merger process. Previously, scientists had used the German-US Roentgensatellite to produce a broad brush picture of the cluster. The elongated shape of the bright cloud suggested that two clouds were in the process of coalescing into one, but the details remained unclear. Chandra is able to measure variations of temperature, density, and pressure with unprecedented resolution. "Now we can begin to understand the physics of these mergers, which are among the most energetic events in the universe," said Markevitch. "The pressure and density maps of the cluster show a sharp boundary that can only exist in the moving environment of a

  10. TopN-Pareto Front Search

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-21

    The JMP Add-In TopN-PFS provides an automated tool for finding layered Pareto front to identify the top N solutions from an enumerated list of candidates subject to optimizing multiple criteria. The approach constructs the N layers of Pareto fronts, and then provides a suite of graphical tools to explore the alternatives based on different prioritizations of the criteria. The tool is designed to provide a set of alternatives from which the decision-maker can select the best option for their study goals.

  11. Pole solutions for flame front propagation

    CERN Document Server

    Kupervasser, Oleg

    2015-01-01

    This book deals with solving mathematically the unsteady flame propagation equations. New original mathematical methods for solving complex non-linear equations and investigating their properties are presented. Pole solutions for flame front propagation are developed. Premixed flames and filtration combustion have remarkable properties: the complex nonlinear integro-differential equations for these problems have exact analytical solutions described by the motion of poles in a complex plane. Instead of complex equations, a finite set of ordinary differential equations is applied. These solutions help to investigate analytically and numerically properties of the flame front propagation equations.

  12. RF front-end world class designs

    CERN Document Server

    Love, Janine

    2009-01-01

    All the design and development inspiration and direction a harware engineer needs in one blockbuster book! Janine Love site editor for RF Design Line,columnist, and author has selected the very best RF design material from the Newnes portfolio and has compiled it into this volume. The result is a book covering the gamut of RF front end design from antenna and filter design fundamentals to optimized layout techniques with a strong pragmatic emphasis. In addition to specific design techniques and practices, this book also discusses various approaches to solving RF front end design problems and h

  13. Moving through a multiplex holographic scene

    Science.gov (United States)

    Mrongovius, Martina

    2013-02-01

    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  14. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-01-08

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  15. Transient heating of moving objects

    Directory of Open Access Journals (Sweden)

    E.I. Baida

    2014-06-01

    Full Text Available A mathematical model of transient and quasistatic heating of moving objects by various heat sources is considered. The mathematical formulation of the problem is described, examples of thermal calculation given.

  16. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-11-09

    We present a general framework and method for detection of an object in a video based on apparent motion. The object moves relative to background motion at some unknown time in the video, and the goal is to detect and segment the object as soon it moves in an online manner. Due to unreliability of motion between frames, more than two frames are needed to reliably detect the object. Our method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  17. Phenomena of insulin peak fronting in size exclusion chromatography and strategies to reduce fronting.

    Science.gov (United States)

    Yu, Chi-Ming; Mun, Sungyong; Wang, Nien-Hwa Linda

    2008-05-23

    Insulin peak fronting in size exclusion chromatography (SEC) results in more than 10% yield loss in the production of insulin. The goal of this study is to understand the mechanisms of peak fronting and to develop strategies to reduce fronting and increase insulin yield. Chromatography experiments ruled out pressure surge, viscous fingering, and adsorption as the cause for peak fronting. Theoretical analysis based on a general rate model indicated that reversible dimerization is the major cause for peak fronting and reducing the dimerization equilibrium constant is the most effective method for reducing fronting. Two strategies were developed and tested to reduce the degree of dimer formation. The first strategy was to use 0.1N acetic acid as the presaturant and eluent. The second strategy was to use 0.8 or 2.8N acetic acid in 20vol.% denatured ethanol as the mobile phase. The experimental results showed that both strategies can reduce insulin peak fronting in SEC, maintain desired product purity, and increase insulin yield to higher than 98%.

  18. On Multiple Questions and Multiple WH Fronting.

    Science.gov (United States)

    Rudin, Catherine

    An analysis of languages with multiple fronting of WH words (who, what, whom, etc.) looks in detail at Polish, Serbo-Croatian, Czech, Bulgarian (Slavic languages), and Romanian (a Romance language). In spite of their superficial similarity, the Slavic and East European languages that normally put all WH words at the beginning of clauses fall into…

  19. "All Quiet on the Western Front."

    Science.gov (United States)

    Soderquist, Alisa

    Based on Erich Maria Remarque's novel "All Quiet on the Western Front" and other war literature, this lesson plan presents activities designed to help students understand that works of art about war can call up strong emotions in readers; and that the writing process can be applied to writing poems. The main activity of the lesson involves…

  20. Light-Front Dynamics in Hadron Physics

    NARCIS (Netherlands)

    Ji, C.R.; Bakker, B.L.G.; Choi, H.M.

    2013-01-01

    Light-front dynamics(LFD) plays an important role in the analyses of relativistic few-body systems. As evidenced from the recent studies of generalized parton distributions (GPDs) in hadron physics, a natural framework for a detailed study of hadron structures is LFD due to its direct application in

  1. Displacement Processes in Stable Drainage Fronts

    Science.gov (United States)

    Breen, S. J.; Pride, S. R.; Manga, M.

    2016-12-01

    Drainage fronts are stabilized at large bond number, when a low density nonwetting fluid displaces a high density wetting fluid from above. This is an ideal flow scenario for studying the correspondence between pore scale processes and continuum models because the front is a persistent macroscale feature that is propagated by discrete, multiplepore scale displacements. We present new observations of stable air/water drainage in thin, threedimensional, poured bead packs at varying capillary number. With backlighting and a high speed camera, we observe short range front velocities that are an order of magnitude larger than bulk pore velocity, consistent with previous studies in ordered 2D structures. We also quantify displacement lengths and front width. For comparison to continuum simulations, we measure saturation by light transmission continuously over a series of 1 cm length voxels. We focus on the critical nonwetting saturation (CNS, or "emergence point") at which voxels are percolated by air and continuum air permeability becomes nonzero. We find that mean CNS is capillary number dependent even at large bond number, with larger CNS at lower capillary number. Continuum simulations with an equivalent discretization demonstrate that CNS is a significant source of uncertainty for predictions of the time and saturation profile at chamber-length air breakthrough.

  2. Teaching Front Handsprings from a Developmental Approach

    Science.gov (United States)

    Stork, Steve

    2006-01-01

    The front handspring is an important gymnastics skill that serves as a transition from beginner-level rolling and static balances to more advanced tumbling. It is, therefore, a skill highly desired by beginners. Early learning requires a great deal of effort during which students experience many failed attempts. Unless they are highly motivated,…

  3. Discretionary Power on the Front-line

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum; Lønsmann, Dorte

    and document data, our findings show that employees face a number of different language boundaries in their everyday work, and that ad hoc and informal solutions in many cases are vital for successful cross-language communication. We introduce the concept of ‘discretionary power’ to explain how and why front...

  4. Front-end conceptual platform modeling

    DEFF Research Database (Denmark)

    Guðlaugsson, Tómas Vignir; Ravn, Poul Martin; Mortensen, Niels Henrik

    2014-01-01

    Platform thinking has been the subject of investigation and deployment in many projects in both academia and industry. Most contributions involve the restructuring of product programs, and only a few support front-end development of a new platform in parallel with technology development. This con......Platform thinking has been the subject of investigation and deployment in many projects in both academia and industry. Most contributions involve the restructuring of product programs, and only a few support front-end development of a new platform in parallel with technology development....... This contribution deals with the development of product platforms in front-end projects and introduces a modeling tool: the Conceptual Product Platform model. State of the art within platform modeling forms the base of a modeling formalism for a Conceptual Product Platform model. The modeling formalism is explored...... through an example and applied in a case in which the Conceptual Product Platform model has supported the front-end development of a platform for an electro-active polymer technology. The case describes the contents of the model and how its application supported the development work in the project...

  5. Front-end electronics for imaging detectors

    CERN Document Server

    Geronimo, G D; Radeka, V; Yu, B

    2001-01-01

    Front-end electronics for imaging detectors with large numbers of pixels (10 sup 5 -10 sup 7) is reviewed. The noise limits as a function of detector capacitance and power dissipation are presented for CMOS technology. Active matrix flat panel imagers (AMFPIs) are discussed and their potential noise performance is illustrated.

  6. QCD and Light-Front Holography

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.; /Costa Rica U.

    2010-10-27

    The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics. The model predicts a zero-mass pion for zero-mass quarks and a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number N. Light-Front Holography maps the amplitudes which are functions of the fifth dimension variable z of anti-de Sitter space to a corresponding hadron theory quantized on the light front. The resulting Lorentz-invariant relativistic light-front wave equations are functions of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. The result is to a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryon light-quark bound states, which in turn predict the behavior of the pion and nucleon form factors. The theory implements chiral symmetry in a novel way: the effects of chiral symmetry breaking increase as one goes toward large interquark separation, consistent with spectroscopic data, and the the hadron eigenstates generally have components with different orbital angular momentum; e.g., the proton eigenstate in AdS/QCD with massless quarks has L = 0 and L = 1 light-front Fock components with equal probability. The soft-wall model also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS} (Q) and its {beta}-function which agrees with the effective coupling {alpha}{sub g1} extracted from the Bjorken sum rule. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method in order to systematically include the QCD interaction terms. A new perspective on quark and gluon condensates is also reviewed.

  7. Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

    DEFF Research Database (Denmark)

    Brodsky, S. J.; de Teramond, G. F.

    2012-01-01

    -classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions...... the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate zeta which measures the separation of the constituents within a hadron at equal light-front time and determines...

  8. Environment and morphology of mesoscale convective systems associated with the Changma front during 9–10 July 2007

    Directory of Open Access Journals (Sweden)

    J.-H. Jeong

    2012-08-01

    Full Text Available To understand the different environment and morphology for heavy rainfall during 9–10 July 2007, over the Korean Peninsula, mesoscale convective systems (MCSs that accompanied the Changma front in two different regions were investigated. The sub-synoptic conditions were analysed using mesoscale analysis data (MANAL, reanalysis data, weather charts and Multi-functional Transport Satellite (MTSAT-IR data. Dual-Doppler radar observations were used to analyse the wind fields within the precipitation systems. During both the case periods, the surface low-pressure field intensified and moved northeastward along the Changma front. A low-level warm front gradually formed with an east-west orientation, and the cold front near the low pressure was aligned from northeast to southwest. The northern convective systems (meso-α-scale were embedded within an area of stratiform cloud north of the warm front. The development of low-level pressure resulted in horizontal and vertical wind shear due to cyclonic circulation. The wind direction was apparently different across the warm front. In addition, the southeasterly flow (below 4 km played an important role in generating new convective cells behind the prevailing convective cell. Each isolated southern convective cell (meso-β-scale moved along the line ahead of the cold front within the prefrontal warm sector. These convective cells developed when a strong southwesterly low-level jet (LLJ intensified and moisture was deeply advected into the sloping frontal zone. A high equivalent potential temperature region transported warm moist air in a strong southwesterly flow, where the convectively unstable air led to updraft and downdraft with a strong reflectivity core.

  9. QCD Phenomenology and Light-Front Wavefunctions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2001-11-21

    A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions.

  10. Moving event and moving participant in aspectual conceptions

    Directory of Open Access Journals (Sweden)

    Izutsu Katsunobu

    2016-06-01

    Full Text Available This study advances an analysis of the event conception of aspectual forms in four East Asian languages: Ainu, Japanese, Korean, and Ryukyuan. As earlier studies point out, event conceptions can be divided into two major types: the moving-event type and the moving-participant type, respectively. All aspectual forms in Ainu and Korean, and most forms in Japanese and Ryukyuan are based on that type of event conception. Moving-participant oriented Ainu and movingevent oriented Japanese occupy two extremes, between which Korean and Ryukyuan stand. Notwithstanding the geographical relationships among the four languages, Ryukyuan is closer to Ainu than to Korean, whereas Korean is closer to Ainu than to Japanese.

  11. Minimum Delay Moving Object Detection

    KAUST Repository

    Lao, Dong

    2017-05-14

    This thesis presents a general framework and method for detection of an object in a video based on apparent motion. The object moves, at some unknown time, differently than the “background” motion, which can be induced from camera motion. The goal of proposed method is to detect and segment the object as soon it moves in an online manner. Since motion estimation can be unreliable between frames, more than two frames are needed to reliably detect the object. Observing more frames before declaring a detection may lead to a more accurate detection and segmentation, since more motion may be observed leading to a stronger motion cue. However, this leads to greater delay. The proposed method is designed to detect the object(s) with minimum delay, i.e., frames after the object moves, constraining the false alarms, defined as declarations of detection before the object moves or incorrect or inaccurate segmentation at the detection time. Experiments on a new extensive dataset for moving object detection show that our method achieves less delay for all false alarm constraints than existing state-of-the-art.

  12. Mineral replacement front propagation in deformed rocks

    Science.gov (United States)

    Beaudoin, Nicolas; Koehn, Daniel; Kelka, Ulrich

    2015-04-01

    Fluid migrations are a major agent of contaminant transport leading to mineral replacement in rocks, impacting their properties as porosity, permeability, and rheology. Understanding the physical and chemical mechanisms that govern mineralogical replacement during and after deformation is required to better understand complex interplays between fluid and rocks that are involved in faulting, seismic cycle, and resource distribution in the upper crust. Dolomitization process related to hydrothermal fluid flow is one of the most studied and debated replacement processes in earth sciences. Dolomitization of limestone is of economic importance as well, as it stands as unconventional oil reservoirs and is systematically observed in Mississippian-Valley Type ore deposit. Despite recent breakthrough about dolomitization processes at large-scale, the small-scale propagation of the reaction front remains unclear. It is poorly documented in the occurrence of stylolites and fractures in the medium while pressure-solution and fracture network development are the most efficient deformation accomodation mechanism in limestone from early compaction to layer-parallel shortening. Thus, the impact of such network on geometry of replaced bodies and on replacement front propagation deserves specific attention. This contribution illustrates the role of fracture and stylolites on the propagation of a reaction front. In a 2 dimensional numerical model we simulate the dolomitization front propagation in a heterogeneous porous medium. The propagation of the reaction front is governed by the competition between advection and diffusion processes, and takes into account reaction rates, disorder in the location of the potential replacement seeds, and permeability heterogeneities. We add stylolites and fractures that can act as barriers or drains to fluid flow according to their orientation and mineralogical content, which can or cannot react with the contaminant. The patterns produced from

  13. MOVES Degree Update: Curriculum Revision Proposal

    OpenAIRE

    Darken, Chris

    2012-01-01

    MOVES Research & Education Systems Seminar: Presentation; Session 1: Educational Initiatives and Status, Moderator: Chris Darken; MOVES Degree Update, Speaker Chris Darken Outline: Brief intro to MOVES Masters degree, Pressures driving the proposed curriculum revision, Salient features of the proposal

  14. Remote moving target indication assessment

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1996-10-01

    The objective of this project was to design and test key components of a sensor to be used on remotely piloted vehicles, aircraft, or satellites for the detection of moving vehicles in cluttered backgrounds. The proposed sensor uses modern large-array focal planes to provide multiple infrared observations of moving targets and capable on-board computers to integrate multiple observations to detect moving targets in background clutter. This combination reduces the size, weight, and cost of the sensor to levels that can be flown on many small unmanned platforms. This effort selected the actual components, integrated them into a test bed, tested the performance of the sensor against realistic generated scenes, and designed a proof-of-concept prototype.

  15. Analytical solution of the problem of dissolved gas segregation in melt by the plain crystallization front

    Science.gov (United States)

    Chernov, A. A.; Pil'nik, A. A.

    2018-02-01

    Analytical solution of the segregation problem is found for the arbitrary crystal growth law using the quasi-steady-state approximation. The segregation in this case is caused by the displacement of dissolved gas by moving plane crystallization front. The effect of solidification shrinkage on the crystallization process was taken into account. The comparison made between obtained solution and existing exact solutions shows good agreement. It is shown that in the case of "equilibrium crystallization" (when the growth rate is inversely proportional to time) the solution of the problem becomes self-similar. In this case gas concentration at the crystallization front instantly increases to a certain value and than stays the same during the whole process. At the same time the diffusion layer thickness increases proportionally to time. The conditions for the inevitability of gaseous release leading to the formation of pores in solidified material is formulated for the general case.

  16. Multiclass gene selection using Pareto-fronts.

    Science.gov (United States)

    Rajapakse, Jagath C; Mundra, Piyushkumar A

    2013-01-01

    Filter methods are often used for selection of genes in multiclass sample classification by using microarray data. Such techniques usually tend to bias toward a few classes that are easily distinguishable from other classes due to imbalances of strong features and sample sizes of different classes. It could therefore lead to selection of redundant genes while missing the relevant genes, leading to poor classification of tissue samples. In this manuscript, we propose to decompose multiclass ranking statistics into class-specific statistics and then use Pareto-front analysis for selection of genes. This alleviates the bias induced by class intrinsic characteristics of dominating classes. The use of Pareto-front analysis is demonstrated on two filter criteria commonly used for gene selection: F-score and KW-score. A significant improvement in classification performance and reduction in redundancy among top-ranked genes were achieved in experiments with both synthetic and real-benchmark data sets.

  17. Front contact solar cell with formed emitter

    Science.gov (United States)

    Cousins, Peter John [Menlo Park, CA

    2012-07-17

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  18. Frontón en Aroztegia

    OpenAIRE

    Arraztoa Brust, Xabier

    2011-01-01

    El objetivo de este proyecto fin de carrera es el diseño global de un frontón cubierto con sus correspondientes gradas e instalaciones en el barrio Aroztegia de la localidad de Lekaroz, en el Valle de Baztán. Asimismo y respecto al cálculo estructural, se ha diseñado y calculado una estructura metálica, la cubierta y su cimentación de hormigón armado correspondiente. Cabe destacar que las características y medidas del frontón lo hacen apto para la alta competición de pelota a mano, paleta con...

  19. Laser modes with helical wave fronts

    Science.gov (United States)

    Harris, M.; Hill, C. A.; Tapster, P. R.; Vaughan, J. M.

    1994-04-01

    We report the operation of an argon-ion laser in pure (single-frequency) ``doughnut'' modes of order m=1, 2, and 3. The phase discontinuity at the center of these modes leads to striking two-beam interference patterns that clearly demonstrate the existence of a helical cophasal surface (wave front). The doughnut mode with m=1 (usually called TEM*01) displays a forking interference fringe pattern characteristic of a pure single helix. The m=2 mode shows a pattern with four extra prongs, establishing that the cophasal surface is a two-start or double helix; the m=3 mode is a triple helix with a six-extra-pronged pattern. Each pure doughnut mode is shown to have two possible states corresponding to output wave fronts of opposite helicity.

  20. Dispersion management of the SULF front end

    Science.gov (United States)

    Li, Shuai; Wang, Cheng; Liu, Yanqi; Xu, Yi; Liu, Zhengzheng; Lu, Jun; Li, Yanyan; Liu, Xingyan; Li, Zhaoyang; Leng, Yuxin; Li, Ruxin

    2017-04-01

    To manage dispersion of the front end in the Shanghai Superintense Ultrafast Laser Facility (SULF), which is a large-scale project aimed at delivering 10 PW laser pulses, a stretcher based on a combination of a grating and a prism (grism) pair is inserted between an Öffner-triplet-type stretcher and a regenerative amplifier to reduce high-order dispersion introduced by optical materials at the amplification stage. The alignment of the grism pair is implemented by controlling the far-field pattern of the output beam of the grism pair. The energy of the front end reaches up to 7 J at a 1-Hz repetition rate. Experimental results show that the pulse duration can be compressed to 22.4 fs and the spectral distortion over the spectrum is less than 2.25 rad.

  1. QUENCH FRONT PROPAGATION IN THE ANNULAR CHANNEL

    Directory of Open Access Journals (Sweden)

    Jan Stepanek

    2016-12-01

    Full Text Available Understanding the quench front propagation during bottom core reflooding is crucial for the effective cooling during the LOCA accident. The results presented in this paper were obtained on an experimental loop with an annular test section. The test section consists of a vertical electrically heated stainless steel tube with outer diameter 9 mm and length of 1.7 m. The heated tube is placed inside a glass tube with the inner diameter 14.5 mm. Water mass flux during the reflooding is in the range from 100 kg.m−2.s−1 up to 140 kg.m−2.s−1 and the initial wall temperature of the stainless steel tube is in the range from 250 °C up to 800 °C. The presented results show the influence of the initial conditions on the quench front propagation and the complexity of the phenomenon.

  2. SEEDS Moving Group Status Update

    Science.gov (United States)

    McElwain, Michael

    2011-01-01

    I will summarize the current status of the SEEDS Moving Group category and describe the importance of this sub-sample for the entire SEEDS survey. This presentation will include analysis of the sensitivity for the Moving Groups with general a comparison to other the other sub-categories. I will discuss the future impact of the Subaru SCExAO system for these targets and the advantage of using a specialized integral field spectrograph. Finally, I will present the impact of a pupil grid mask in order to produce fiducial spots in the focal plane that can be used for both photometry and astrometry.

  3. Lawfare: The Legal Front of the IDF

    OpenAIRE

    Avihai Mandelblit

    2012-01-01

    Lawfare is closely linked to the theme of this issue of Military and Strategic Affairs: the challenges facing the regular armies of law-abiding nations engaged in asymmetrical confrontations in densely populated civilian urban areas. Therefore, as part of its preparations for the challenges it may have to face in the future, particularly in this type of fighting, the IDF must give the proper weight to the legal front that is likely to develop as an integral part of the same confrontation.

  4. Front roughening of flames in discrete media

    Science.gov (United States)

    Lam, Fredric; Mi, XiaoCheng; Higgins, Andrew J.

    2017-07-01

    The morphology of flame fronts propagating in reactive systems composed of randomly positioned, pointlike sources is studied. The solution of the temperature field and the initiation of new sources is implemented using the superposition of the Green's function for the diffusion equation, eliminating the need to use finite-difference approximations. The heat released from triggered sources diffuses outward from each source, activating new sources and enabling a mechanism of flame propagation. Systems of 40 000 sources in a 200 ×200 two-dimensional domain were tracked using computer simulations, and statistical ensembles of 120 realizations of each system were averaged to determine the statistical properties of the flame fronts. The reactive system of sources is parameterized by two nondimensional values: the heat release time (normalized by interparticle diffusion time) and the ignition temperature (normalized by adiabatic flame temperature). These two parameters were systematically varied for different simulations to investigate their influence on front propagation. For sufficiently fast heat release and low ignition temperature, the front roughness [defined as the root mean square deviation of the ignition temperature contour from the average flame position] grew following a power-law dependence that was in excellent agreement with the Kardar-Parisi-Zhang (KPZ) universality class (β =1 /3 ). As the reaction time was increased, lower values of the roughening exponent were observed, and at a sufficiently great value of reaction time, reversion to a steady, constant-width thermal flame was observed that matched the solution from classical combustion theory. Deviation away from KPZ scaling was also observed as the ignition temperature was increased. The features of this system that permit it to exhibit both KPZ and non-KPZ scaling are discussed.

  5. Developing leadership skills at the front line.

    Science.gov (United States)

    Jeavons, Richard

    2011-10-01

    The health secretary announced in July plans to launch a NHS Leadership Academy. This article explains what progress has been made in setting up the body and enabling it to support nurses and other front line staff to develop the leadership skills needed to transform the NHS into a genuinely patient-centred service, one in which different services work together to provide integrated care.

  6. Chemical air mass differences near fronts

    OpenAIRE

    Bethan, S.; Vaughan, G.; Gerbig, C.; Volz-Thomas, A.; Richer, H; Tiddeman, D.

    1998-01-01

    Two case studies are presented of aircraft measurements (ozone, NOy, CO, and meteorological parameters) in the Vicinity of fronts located over the eastern side of the North Atlantic Ocean during spring 1994. The aim of these studies was twofold: (1) to investigate whether frontal circulations can transport ozone from the boundary layer to the free troposphere in well-defined layer; and (2) to ascertain whether or not conveyor belts associated with extratropical cyclones exhibit well-defined c...

  7. Trunk muscle activity during front crawl swimming

    OpenAIRE

    Martens, Jonas; Pellegrims, Ward; Einarsson, Ingi Thor; Fernandes, Ricardo; Staes, Filip; Daly, Daniel

    2013-01-01

    Introduction Core stability training is of increasing interest to both researchers and coaches. Sufficient core stability is needed to balance forces generated by the upper and lower extremities separately (Hibbs et al., 2008). In swimming the development of wireless EMG has created new possibilities to study underwater muscle activity with little hinder. The purpose here was to analyze lower trunk muscle activation during front crawl swimming and examine how trunk muscle activity is relat...

  8. Combustion Waves and Fronts in Flows

    Science.gov (United States)

    Clavin, Paul; Searby, Geoff

    2016-07-01

    Preface; Introduction; Part I. Physical Insights: 1. General considerations; 2. Laminar premixed flames; 3. Turbulent premixed flames; 4. Gaseous shocks and detonations; 5. Chemical kinetics of combustion; 6. Laser-driven ablation front in ICF; 7. Explosion of massive stars; Part II. Detailed Analytical Studies: 8. Planar flames; 9. Flame kernels and flame balls; 10. Wrinkled flames; 11. Ablative Rayleigh-Taylor instability; 12. Shock waves and detonations; Part III. Complements: 13. Statistical physics; 14. Chemistry; 15. Flows; References; Index.

  9. Prototype ALICE front-end card

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    This circuit board is a prototype 48-channel front end digitizer card for the ALICE time projection chamber (TPC), which takes electrical signals from the wire sensors in the TPC and shapes the data before converting the analogue signal to digital data. A total of 4356 cards will be required to process the data from the ALICE TPC, the largest of this type of detector in the world.

  10. On the Front Lines of Rare Disease Research

    Science.gov (United States)

    ... turn JavaScript on. Feature: Rare Diseases On the Front Lines of Rare Disease Research Past Issues / Spring ... Diagnosis" Making the Invisible Patients Visible / On the Front Lines of Rare Disease Research Spring 2016 Issue: ...

  11. Kinetics of a plasma streamer ionization front

    Science.gov (United States)

    Taccogna, Francesco; Pellegrini, Fabrizio

    2018-02-01

    A streamer is a non-linear and non-local gas breakdown mode. Its large-scale coherent structures, such as the ionization front, are the final results of a hierarchical cascade starting from the single particle dynamics. Therefore, this phenomenon covers, by definition, different space and time scales. In this study, we have reproduced the ionization front formation and development by means of a particle-based numerical methodology. The physical system investigated concerns of a high-voltage ns-pulsed surface dielectric barrier discharge. Different reduced electric field regimes ranging from 50 to 500 Td have been considered for two gases: pure atomic Ar and molecular N2. Results have shown the detailed structure of the negative streamer: the leading edge, the head, the interior and the tail. Its dynamical evolution and the front propagation velocity have been calculated for the different cases. Finally, the deviation of the electron energy distribution function from equilibrium behavior has been pointed out as a result of a fast and very localized phenomenon.

  12. Exoplanet Caught on the Move

    Science.gov (United States)

    2010-06-01

    For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves from one side of its host star to the other. The planet has the smallest orbit so far of all directly imaged exoplanets, lying almost as close to its parent star as Saturn is to the Sun. Scientists believe that it may have formed in a similar way to the giant planets in the Solar System. Because the star is so young, this discovery proves that gas giant planets can form within discs in only a few million years, a short time in cosmic terms. Only 12 million years old, or less than three-thousandths of the age of the Sun, Beta Pictoris is 75% more massive than our parent star. It is located about 60 light-years away towards the constellation of Pictor (the Painter) and is one of the best-known examples of a star surrounded by a dusty debris disc [1]. Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star. "Those were indirect, but tell-tale signs that strongly suggested the presence of a massive planet, and our new observations now definitively prove this," says team leader Anne-Marie Lagrange. "Because the star is so young, our results prove that giant planets can form in discs in time-spans as short as a few million years." Recent observations have shown that discs around young stars disperse within a few million years, and that giant planet formation must occur faster than previously thought. Beta Pictoris is now clear proof that this is indeed possible. The team used the NAOS-CONICA instrument (or NACO [2]), mounted on one of the 8.2-metre Unit Telescopes of ESO's Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen (eso0842), but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared! The most recent

  13. Unstable fronts and motile structures formed by microrollers

    Science.gov (United States)

    Driscoll, Michelle; Delmotte, Blaise; Youssef, Mena; Sacanna, Stefano; Donev, Aleksandar; Chaikin, Paul

    2017-04-01

    Condensation of objects into stable clusters occurs naturally in equilibrium and driven systems. It is commonly held that potential interactions, depletion forces, or sensing are the only mechanisms which can create long-lived compact structures. Here we show that persistent motile structures can form spontaneously from hydrodynamic interactions alone, with no sensing or potential interactions. We study this structure formation in a system of colloidal rollers suspended and translating above a floor, using both experiments and large-scale three-dimensional simulations. In this system, clusters originate from a previously unreported fingering instability, where fingers pinch off from an unstable front to form autonomous `critters’, whose size is selected by the height of the particles above the floor. These critters are a stable state of the system, move much faster than individual particles, and quickly respond to a changing drive. With speed and direction set by a rotating magnetic field, these active structures offer interesting possibilities for guided transport, flow generation, and mixing at the microscale.

  14. Emulsion droplet interactions: a front-tracking treatment

    Science.gov (United States)

    Mason, Lachlan; Juric, Damir; Chergui, Jalel; Shin, Seungwon; Craster, Richard V.; Matar, Omar K.

    2017-11-01

    Emulsion coalescence influences a multitude of industrial applications including solvent extraction, oil recovery and the manufacture of fast-moving consumer goods. Droplet interaction models are vital for the design and scale-up of processing systems, however predictive modelling at the droplet-scale remains a research challenge. This study simulates industrially relevant moderate-inertia collisions for which a high degree of droplet deformation occurs. A hybrid front-tracking/level-set approach is used to automatically account for interface merging without the need for `bookkeeping' of interface connectivity. The model is implemented in Code BLUE using a parallel multi-grid solver, allowing both film and droplet-scale dynamics to be resolved efficiently. Droplet interaction simulations are validated using experimental sequences from the literature in the presence and absence of background turbulence. The framework is readily extensible for modelling the influence of surfactants and non-Newtonian fluids on droplet interaction processes. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM), PETRONAS.

  15. Topology optimization of front metallization patterns for solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Barink, M.; Keulen, F. van

    2015-01-01

    This paper presents the application of topology optimization (TO) for designing the front electrode patterns for solar cells. Improving the front electrode design is one of the approaches to improve the performance of the solar cells. It serves to produce the voltage distribution for the front

  16. 76 FR 63656 - Front Range Resource Advisory Council Meeting Cancellation

    Science.gov (United States)

    2011-10-13

    ...] Front Range Resource Advisory Council Meeting Cancellation AGENCY: Bureau of Land Management, Interior... Front Range Resource Advisory Council meeting scheduled for October 19, 2011 at the BLM Royal Gorge....m. to 4:30 p.m. FOR FURTHER INFORMATION CONTACT: Tina Brown, Front Range RAC Coordinator, BLM...

  17. Kinematic analysis of three water polo front crawl styles.

    Science.gov (United States)

    De Jesus, Karla; Figueiredo, Pedro; De Jesus, Kelly; Pereira, Filipa; Vilas-Boas, J Paulo; Machado, Leandro; Fernandes, Ricardo J

    2012-01-01

    During water polo matches, players use different front crawl styles. The purpose of this study was to conduct a kinematic analysis of three water polo front crawl styles: front crawl with head under water, front crawl with head above water, and front crawl when leading the ball. Ten proficient water polo players performed 3 × 15 m sprints in each front crawl style, which were recorded three-dimensionally by two surface and four underwater cameras. The results showed no differences in performance and several kinematic characteristics among the water polo front crawl styles. However, front crawl when leading the ball showed shorter stroke length and greater stroke frequency. Front crawl with head underwater presented greater maximal finger depth and elbow angle at mid-stroke position. Front crawl with head above water and when leading the ball showed greater trunk obliquity and maximal depth of right and left foot, and shorter kick stroke frequency. The findings suggest that proficient players learn to master front crawl with head above water to achieve top velocity. Despite the common use of the front crawl with head underwater as the basis for water polo fast displacement, coaches should emphasize the use of the specific water polo styles to attain high performance.

  18. 49 CFR 393.44 - Front brake lines, protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Front brake lines, protection. 393.44 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.44 Front brake lines, protection. On every bus, if... any of the front wheels is broken, the driver can apply the brakes on the rear wheels despite such...

  19. 16 CFR 1512.13 - Requirements for front fork.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for front fork. 1512.13 Section 1512.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.13 Requirements for front fork. The front fork shall...

  20. Carlson Wagonlit Travel is moving

    CERN Multimedia

    2013-01-01

    The renovation of the Main Building continues!   Because of this, Carlson Wagonlit Travel will move from building 62 to building 510 on 4 October and the agency will be closed in the afternoon. An emergency service will be organised for official travels only. Phone: 022 799 75 73 & 022 799 75 78 / e-mail: cern@carlsonwagonlit.ch

  1. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    2015-02-19

    Feb 19, 2015 ... Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling ...

  2. Gaussian moving averages and semimartingales

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas

    2008-01-01

    are constructive - meaning that they provide a simple method to obtain kernels for which the moving average is a semimartingale or a Wiener process. Several examples are considered. In the last part of the paper we study general Gaussian processes with stationary increments. We provide necessary and sufficient...

  3. Flame front. Evaluation of camera based flame front control in grate furnaces regarding operation and emissions; Flamfront. Utvaerdering av drift och miljoe med hjaelp av kamerabaserad flamfrontsstyrning i rosterpannor

    Energy Technology Data Exchange (ETDEWEB)

    Bubholz, Monika; Myringer, Aase; Nordgren, Daniel

    2007-09-15

    This project aims at showing the usability of camera based flame front control in grate furnaces regarding increased possibilities to use fuels with fluctuating moisture/quality with stable/improved levels of emissions and ash quality. A furnace camera and the human eye make the detection of the flame front movements. Further, the flame front was fixed due to an increase/decrease of the speed of the fuel feeding system. The result is to be generalised for all grate furnaces with a movable grate. During the spring 2007 two weeks of tests were executed at E.ON Heat's plant Hammargaarden at Kungsbacka. Dry and wet fuel pulses of approximately 10 m3, with moisture content of approximately 40 and 60 weights percent, were induced to the grate. At the same time, tries to ward off the flame front movement were carried through. The most important result of the tests were the following: The results is based on a relatively small number of tests and it should be considered to be more of an indication of the usefulness of the control strategy that has been investigated rather than definitive results. The results indicate that the economical and environmental benefits from using a system involving only visual detecting followed by warding off a movement of the flame front mechanically are small, and most likely hard to pay off. It is important to start to ward off the flame front as soon as it seems to be moving. In this way the flame front can be kept stable and often improved emission levels follow. A slight tendency to lower CO-emissions was observed when dry fuel pulses were warded off. When no warding off of dry fuel pulses took place, the combustion took place close to the lower part of the fuel-feeding wall. This was prevented when the dry fuel pulses were warded off. The content of unburnt carbon in ash at wet fuel pulses was lower when warding off in comparison with cases where no warding off took place. An important element of future work is, apart from using a

  4. Simulation study of the ionizing front in the critical ionization velocity phenomenon

    Science.gov (United States)

    Machida, S.; Goertz, C. K.; Lu, G.

    1988-01-01

    The simulation of the critical ionization velocity for a neutral gas cloud moving across the static magnetic field is presented. A low-beta plasma is studied, using a two and a half-dimensional electrostatic code linked with the Plasma and Neutral Interaction Code (Goertz and Machida, 1987). The physics of the ionizing front and the instabilities which occur there are discussed. Results are presented from four numerical runs designed so that the effects of the charge separation field can be distinguished from the wave heating.

  5. Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End

    Science.gov (United States)

    Prokop, Norman; Krasowski, Michael

    2013-01-01

    This innovation is capable of correlating two analog signals by using an analog-based signal conditioning front end to hard-limit the analog signals through adaptive thresholding into a binary bit stream, then performing the correlation using a Hamming "similarity" calculator function embedded in a one-bit digital correlator (OBDC). By converting the analog signal into a bit stream, the calculation of the correlation function is simplified, and less hardware resources are needed. This binary representation allows the hardware to move from a DSP where instructions are performed serially, into digital logic where calculations can be performed in parallel, greatly speeding up calculations.

  6. Truncation effects in superdiffusive front propagation with Lévy flights.

    Science.gov (United States)

    Del-Castillo-Negrete, D

    2009-03-01

    A numerical and analytical study of the role of exponentially truncated Lévy flights in the superdiffusive propagation of fronts in reaction-diffusion systems is presented. The study is based on a variation of the Fisher-Kolmogorov equation where the diffusion operator is replaced by a lambda -truncated fractional derivative of order alpha , where 1lambda is the characteristic truncation length scale. For lambda=0 there is no truncation, and fronts exhibit exponential acceleration and algebraically decaying tails. It is shown that for lambda not equal0 this phenomenology prevails in the intermediate asymptotic regime (chit);{1alpha}x1lambda where chi is the diffusion constant. Outside the intermediate asymptotic regime, i.e., for x>1lambda , the tail of the front exhibits the tempered decay varphi approximately e;{-lambdax}x;{(1+alpha)} , the acceleration is transient, and the front velocity v_{L} approaches the terminal speed v_{*}=(gamma-lambda;{alpha}chi)lambda as t-->infinity , where it is assumed that gamma>lambda;{alpha}chi with gamma denoting the growth rate of the reaction kinetics. However, the convergence of this process is algebraic, v_{L} approximately v_{*}-alpha(lambdat) , which is very slow compared to the exponential convergence observed in the diffusive (Gaussian) case. An overtruncated regime in which the characteristic truncation length scale is shorter than the length scale of the decay of the initial condition, 1nu , is also identified. In this extreme regime, fronts exhibit exponential tails, varphi approximately e;{-nux} , and move at the constant velocity v=(gamma-lambda;{alpha}chi)nu .

  7. Effects of Coastal Orography on Landfalling Cold Fronts. Part I: Dry, Inviscid Dynamics.

    Science.gov (United States)

    Braun, Scott A.; Rotunno, Richard; Klemp, Joseph B.

    1999-02-01

    In this study, the interaction of cold fronts with idealized coastal terrain typical of the western United States and Canada is considered. Two issues are examined. First, what are the factors that determine the strength of the coastal winds, and second, what are the orographic effects on the frontal evolution? To address these issues, the authors utilize a two-dimensional, Boussinesq terrain-following coordinate numerical model in which a uniform prescribed flow is forced to move over a plateau. The resultant across-mountain velocities are characterized by a zone of strongly decelerated flow upstream of the windward slope and a train of inertia-gravity waves downstream. A barrier-jet oriented parallel to the mountain is produced by the Coriolis force. The variations of the magnitude of the upstream deceleration and the barrier jet over a wide range of Froude numbers and Rossby numbers are described. Steady, linear theory applied to flow over a plateau shows that the upstream deceleration is determined largely by the shortwave characteristics of the orography while the barrier-jet strength is related to the longwave characteristics of the orography.Simulations that include an initially steady, geostrophically balanced front upstream of the coast indicate that the motion of fronts can be significantly retarded along the coast. Across-frontal circulations induced by frontogenesis or frontolysis caused by the mountain are small compared to the changes in the mountain circulation caused by the stability perturbations associated with the front. The strength of the along-mountain winds in the coastal zone during frontal passage are approximately determined by a superposition of the southerly barrier jet and the frontal jets (e.g., a southerly prefrontal jet and/or northerly postfrontal jet). This result implies that a barrier jet forming ahead of a front can combine with a prefrontal jet to produce very strong winds in the coastal zone prior to frontal passage.

  8. Translating Cuba: Diasporic writing between moving cultures and moving media

    Directory of Open Access Journals (Sweden)

    Andrea Gremels

    2015-04-01

    Full Text Available This article discusses the interrelation between transculturality and transmediality with an emphasis on processes of translation. It focuses on two examples of transcultural and transmedial writing taken from contemporary Cuban literature in Paris: Miguel Sales's recontextualization of Cuban popular music in Paris and William Navarrete's ekphrastic reinscription of his island into the realm of French romantic painting. The case studies are significant in this context because they show how cultural borders are simultaneously set and transgressed at medial crossings—between music and poetry, text, and image. Thus, cultural translations go hand in hand with medial transpositions that include forms of rewriting, recomposition, and revisualization. The connection between moving cultures and moving media also points to the question of “travelling memory” in diaspora.

  9. ALICE: structures weighing several tonnes are moved with millimetric precision

    CERN Multimedia

    2005-01-01

    The ALICE collaboration has just conducted one of its most spectacular transport operations to date in lifting the dipole of the muon spectrometer and reassembling it on the other side of the huge solenoid magnet. This incredible feat involved lifting no fewer than 900 tonnes of equipment over the red octagonal yoke inherited from the L3 experiment at a height of 18 metres. Following initial assembly and successful testing at the end of last year (see Bulletin No. 4/2005), the dipole was completely dismantled and moved to the other end of the cavern. The yoke was transported as 28 modules, each weighing 30 tonnes. The most spectacular feat of all, though, was undoubtedly the removal of the two 32-tonne coils. The first of these was moved on 18 April, as recorded in the following photos: A special lifting gantry weighing 5 tonnes had to be developed to move and install the coils. Huge clamps, which can be seen at the front, were used to rotate these enormous 32-tonne components. The whole assembly was raised ...

  10. Conveying Communicative Intent: Moves and Metadiscourse in Abstract Writing

    Directory of Open Access Journals (Sweden)

    Chuah Ek Lon

    2012-11-01

    Full Text Available Abstracts form the first reading contact of extended discourse in pursuance of a meaningful engagement with a report. An abstract possesses distinct features drawn from a specific genre of academic writing that communicates its discourse intent to any academic or professional community. Among the discourse conventions is the use of a move pattern and metadiscourse elements which together, establishes logical connections with the reader. This paper investigates good communication practice in abstract writing, a significant preliminary that fronts a report. The effectiveness of an abstract specifically, can be tied to the realization of a peculiar move structure that is accompanied by a judicious choice of words and phrases that relates to and involves the reader both interactively and interactionally. A content analysis of the move structure and its underlying metadiscourse in 100 randomly selected abstracts gives petite indication of how students manage abstract writing in a technical report. The results will have a bearing on situating appropriate pedagogical approaches for the teaching of a salient feature in academic writing and will also inform students of related genre expectations towards abstract writing. It is a skill that they may not have sufficient contact with in their university writing experience, though, nonetheless, one that needs to be accomplished to fulfill communicative intent that serves both local and international purposes insofar as academic writing is concerned.

  11. Investigation on the variability of East Asia Boreal Summer Front Frequency and Linkage between Tropical Air Temperature

    Science.gov (United States)

    Choi, Eunho; Lim, Gyu-Ho

    2016-04-01

    Summer time front is one of the most significant phenomena over East Asia including China, Korea and Japan. Many efforts have been established to understand the nature of front. However, there was no research conducting identifying East Asia summer time fronts objectively. We have established objective front recognition method. The method follows next procedures : 1) We calculate vorticity on 850-hPa surface. 2) Any grid point that have horizontal gradient of equivalent potential temperature (EPT hereafter) on 850-hPa surface less than 4 'c / 100km set to zero. 3) Next, we smooth this field using 9-point smoothing technique. 4) Finally we extract the main axis of closed contour correspond to vorticity of 1.5 10-5s-5. Voronoi diagram used to extract this axis. We define this axis as front on 850-hPa pressure surface. We have applied the method on 1981-2010 ERA-Interim dataset. From the result, front frequency maximums are in around of East China Sea (34N, 122E), north (38N, 136E) and south (34N, 140E) of main island of Japan. Below 30N and above 40N, front frequency tends to decrease maybe due to decrease in the magnitude of gradient of EPT and the frequency of cyclonic weather disturbance. Two main regions affect the variability of East Asia Front Frequency. One is equatorial positive region especially over Taiwan (25N, 120E). The other one is East Sea next to Korea (40N, 135E). Humid warm air transported from southern China (20N-30N, 100E-110E) and dry cold air transported from northern China (30N-40N, 100E-110E) compressed by clockwise high system over Taiwan and counter-clockwise low system over East Sea). This compressed precipitation-making system or front moves by extratropical westerly and transported out to north-western Pacific. It looks like geopotential over Taiwan affected by tropical activity, especially vertical integration of temperature (VIT hereafter) over tropical region (30S-30N). When VIT is higher than normal, geopotential over Taiwan also

  12. Stability and propagation of the high field side high density front in the fluctuating state of detachment in ASDEX Upgrade

    OpenAIRE

    Manz, P.; S. Potzel; Reimold, F.; Wischmeier, M.

    2017-01-01

    During detachment a structure of strongly enhanced density develops close to the inner target. Its dynamics is approximated by those of radiative fluctuations appearing at a similar position and studied by means of a time-delay-estimation technique in the ASDEX Upgrade tokamak. Compared to theory the dynamics can be described as follows: at increasing density the ionization front moves upstream to reduce ionization radiation in order to balance the increased recombination radiation. The recom...

  13. A Framework for Representing Moving Objects

    DEFF Research Database (Denmark)

    Becker, Ludger; Blunck, Henrik; Hinrichs, Klaus

    2004-01-01

    We present a framework for representing the trajectories of moving objects and the time-varying results of operations on moving objects. This framework supports the realization of discrete data models of moving objects databases, which incorporate representations of moving objects based on non...

  14. Novel Perspectives from Light-Front QCD, Super-Conformal Algebra, and Light-Front Holography

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    Light-Front Quantization – Dirac’s “Front Form” – provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic LFWFs. One obtains new insights into the hadronic mass scale, the hadronic spectrum, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons. I also discuss evidence that the antishadowing of nuclear structure functions is nonuniversal; i.e., flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with the momentum and other sum rules for the nuclear parton distribution functions.

  15. Moving the campaign from the front door to the front pocket: field experimental evidence on the effect of phrasing and timing of text messages on voter turnout

    DEFF Research Database (Denmark)

    Bhatti, Yosef; Dahlgaard, Jens Olav; Hansen, Jonas Hedegaard

    2017-01-01

    Despite the widespread scholarly attention given to get-out-the-vote tactics the recent one and a half decade, few have studied the effect of short text messages (SMS) on voter turnout, and no previous such study has been conducted outside the US. We analyze four SMS experiments with more than 30...

  16. Direct drive ablation front stability: numerical predictions against flame front model

    Energy Technology Data Exchange (ETDEWEB)

    Masse, L. [Phd Student at IRPHE St Jerome, 13 - Marseille (France)]|[CEA/DAM-Ile de France, 91 - Bruyeres Le Chatel (France); Hallo, L.; Tallot, C. [CEA/DAM-Ile de France, 91 - Bruyeres Le Chatel (France)

    2000-07-01

    We study the linear stability of flows resulting from constant heating of planar targets by a laser. In the coordinate system of the ablation front there is a flow from the cold to hot region, which is situated in a gravity field oriented from hot to cold region. Similar types of flow can be observed in combustion systems, which involve propagation of flame fronts. A spectral model which studies linear perturbation is directly taken from the combustion community. Here we present the results for state as well as perturbed flows. Growth rate determined from the models are compared to each other, and preliminary numerical results from FC12 simulations are shown. (authors)

  17. Learning to Segment Moving Objects in Videos

    OpenAIRE

    Fragkiadaki, Katerina; Arbelaez, Pablo; Felsen, Panna; Malik, Jitendra

    2014-01-01

    We segment moving objects in videos by ranking spatio-temporal segment proposals according to "moving objectness": how likely they are to contain a moving object. In each video frame, we compute segment proposals using multiple figure-ground segmentations on per frame motion boundaries. We rank them with a Moving Objectness Detector trained on image and motion fields to detect moving objects and discard over/under segmentations or background parts of the scene. We extend the top ranked segmen...

  18. Kommuner i front - organisationsudvikling blandt kommunale socialforvaltninger

    DEFF Research Database (Denmark)

    Gregersen, Ole

    Det er næsten et princip, at Folketinget i udformningen af sociallovgivningen ikke blander sig i, hvordan kommunerne skal organisere arbejdet med at føre lovgivningen ud i livet. Det er midlertid oplagt, at der parallelt med den lovgivningsmæssige udvikling sker en organisatorisk udvikling blandt...... ideerne om organisationsforandring er her, at nye organisatoriske elementer spredes fra nogle få pionerer til resten (eller en stor andel af resten) af kommunerne. Et af de interessante spørgsmål i forlængelse af denne tankegang er, om det altid er de samme kommuner, der går i front med...

  19. Moved by a Rapid Transit

    Science.gov (United States)

    Bueter, C.

    2013-04-01

    Enticing by virtue of its predictability, historical utility, and spectacle, the transit of Venus is a niche event among astronomical phenomena. Though the value of a transit for scientific purposes is now diminished, the brief appearance of Venus silhouetted against the background of the Sun in 2004 moved the artistic community to celebrate the rare alignment. Artists of all ages combined old traditions with fresh technology to create a 21st-century tapestry of music, sculpture, paintings, glasswork, quilts, sky shows, and digital imagery. A full catalog of transit-related art generated over the centuries would feature the sampling of entries presented here and at the Moved by a Rapid Transit website.

  20. Moving Tourism Social Entrepreneurship Forward

    DEFF Research Database (Denmark)

    Sheldon, Pauline; Dredge, Dianne; Daniele, Roberto

    2017-01-01

    This chapter concludes the book by considering the role that research and education can play to move the TSE agenda forward. In addition to consolidating the chapter authors’ thoughts about the future of SE and tourism, it also lays out some directions for research tracks in the future. It consid......This chapter concludes the book by considering the role that research and education can play to move the TSE agenda forward. In addition to consolidating the chapter authors’ thoughts about the future of SE and tourism, it also lays out some directions for research tracks in the future....... It considers the changes needed in research approaches, in our universities, our curricula, our learners, and ourselves as academics. These changes we hope will stimulate the dialog on how TSE can mobilize the energy, vision and social spirit of those who seek to change the world for the better through tourism....

  1. Moving Manifolds in Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    David V. Svintradze

    2017-08-01

    Full Text Available We propose dynamic non-linear equations for moving surfaces in an electromagnetic field. The field is induced by a material body with a boundary of the surface. Correspondingly the potential energy, set by the field at the boundary can be written as an addition of four-potential times four-current to a contraction of the electromagnetic tensor. Proper application of the minimal action principle to the system Lagrangian yields dynamic non-linear equations for moving three dimensional manifolds in electromagnetic fields. The equations in different conditions simplify to Maxwell equations for massless three surfaces, to Euler equations for a dynamic fluid, to magneto-hydrodynamic equations and to the Poisson-Boltzmann equation.

  2. IKAR moves to higher energies

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The measurements of hadron elastic scattering on protons at small angle (WA9 experiment) were extended at higher energies (NA8 experiment by the Clermont Ferrand-Leningrad-Lyon-Uppsala Collaboration). To this purpose the set-up was moved to the beam H8 in the EHN1 Hall of the SPS North Area. The photo shows the ionization chamber measuring the recoil energy (centre). Pierre Sahuc stands on the left.

  3. Magnetic Forces on Moving Charges

    OpenAIRE

    2003-01-01

    sim drag Simulation Drag-and-Drop Exercise Interactive Media Element This interactive tutorial provides the practice to reinforce the concept of magnetic force of moving charges. The key concepts covered include: The direction of the resultant magnetic force is always perpendicular to the plane defined by the velocity vector of the charge and the magnetic field vector., The direction of motion of the charge is also influenced by the sign/polarity of the charge., If the velocity...

  4. Saccadic adaptation to moving targets.

    Directory of Open Access Journals (Sweden)

    Katharina Havermann

    Full Text Available Saccades are so called ballistic movements which are executed without online visual feedback. After each saccade the saccadic motor plan is modified in response to post-saccadic feedback with the mechanism of saccadic adaptation. The post-saccadic feedback is provided by the retinal position of the target after the saccade. If the target moves after the saccade, gaze may follow the moving target. In that case, the eyes are controlled by the pursuit system, a system that controls smooth eye movements. Although these two systems have in the past been considered as mostly independent, recent lines of research point towards many interactions between them. We were interested in the question if saccade amplitude adaptation is induced when the target moves smoothly after the saccade. Prior studies of saccadic adaptation have considered intra-saccadic target steps as learning signals. In the present study, the intra-saccadic target step of the McLaughlin paradigm of saccadic adaptation was replaced by target movement, and a post-saccadic pursuit of the target. We found that saccadic adaptation occurred in this situation, a further indication of an interaction of the saccadic system and the pursuit system with the aim of optimized eye movements.

  5. Saccadic adaptation to moving targets.

    Science.gov (United States)

    Havermann, Katharina; Volcic, Robert; Lappe, Markus

    2012-01-01

    Saccades are so called ballistic movements which are executed without online visual feedback. After each saccade the saccadic motor plan is modified in response to post-saccadic feedback with the mechanism of saccadic adaptation. The post-saccadic feedback is provided by the retinal position of the target after the saccade. If the target moves after the saccade, gaze may follow the moving target. In that case, the eyes are controlled by the pursuit system, a system that controls smooth eye movements. Although these two systems have in the past been considered as mostly independent, recent lines of research point towards many interactions between them. We were interested in the question if saccade amplitude adaptation is induced when the target moves smoothly after the saccade. Prior studies of saccadic adaptation have considered intra-saccadic target steps as learning signals. In the present study, the intra-saccadic target step of the McLaughlin paradigm of saccadic adaptation was replaced by target movement, and a post-saccadic pursuit of the target. We found that saccadic adaptation occurred in this situation, a further indication of an interaction of the saccadic system and the pursuit system with the aim of optimized eye movements.

  6. Stability and propagation of the high field side high density front in the fluctuating state of detachment in ASDEX Upgrade

    Directory of Open Access Journals (Sweden)

    P. Manz

    2017-08-01

    Full Text Available During detachment a structure of strongly enhanced density develops close to the inner target. Its dynamics is approximated by those of radiative fluctuations appearing at a similar position and studied by means of a time-delay-estimation technique in the ASDEX Upgrade tokamak. Compared to theory the dynamics can be described as follows: at increasing density the ionization front moves upstream to reduce ionization radiation in order to balance the increased recombination radiation. The recombination zone stays close to the target strike point. The parallel motion of the ionization front is determined by the perpendicular neutral motion. The divertor nose constitutes an obstacle for the perpendicular neutral flux from the target to the region above the X-point. Passing into this shadow the neutral flux above the X-point is strongly reduced, the ionization front fades away and the heat flux from upstream can increase the temperature in the recombination region, subsequently reducing recombination and reforming an ionization front below the X-point. A cyclic reformation of the ionization front propagating from below to above the X-point occurs leading to a fluctuation as observed in the experiment.

  7. Movements and habitat use of White-fronted Geese (Anser albifrons frontalis) during the remigial molt in arctic Alaska, USA

    Science.gov (United States)

    Flint, Paul L.; Meixell, Brandt

    2017-01-01

    Proposed oil and gas leasing in the National Petroleum Reserve - Alaska has raised questions about possible impacts of development on molting Greater White-fronted Geese (Anser albifrons frontalis) and their habitats. We used GPS transmitters to record fine-scale location data of molting and post-molt White-fronted Geese to assess patterns of movement and resource selection relative to vegetation class, year (2012, 2013), and body mass at capture. Molting White-fronted Geese were located an average of 63.3 ± 4.9 m (SE) from lakeshores. Estimated terrestrial home range size for flightless birds differed between years (2012 = 13.2 ± 2.6 km2; 2013 = 6.5 ± 1.8 km2), but did not vary among habitat strata or with body mass. Molting White-fronted Geese used sedge (Carex aquatilus) dominated low centered polygons and water more frequently than expected given proportional habitat availability, but avoided tussock tundra and wet sedge vegetation classes. Upon regaining flight, individuals tended to remain in the same general area, and the center of their home range only moved an average of 6.9 km. Greater White-fronted Geese that could fly tended to forage further from lakeshores ( = 245 m), and used a larger home range ( = 44.3 ± 9.5 km2) than when flightless.

  8. Moving Ahead With Eye Power

    Science.gov (United States)

    2002-01-01

    NASA's Jet Propulsion Laboratory's collaborated with LC Technologies, Inc., to improve LCT's Eyegaze Communication System, an eye tracker that enables people with severe cerebral palsy, muscular dystrophy, multiple sclerosis, strokes, brain injuries, spinal cord injuries, and ALS (amyotrophic lateral sclerosis) to communicate and control their environment using their eye movements. To operate the system, the user sits in front of the computer monitor while the camera focuses on one eye. By looking at control keys on the monitor for a fraction of a second, the user can 'talk' with speech synthesis, type, operate a telephone, access the Internet and e-mail, and run computer software. Nothing is attached to the user's head or body, and the improved size and portability allow the system to be mounted on a wheelchair. LCT and JPL are working on several other areas of improvement that have commercial add-on potential.

  9. AFEII Analog Front End Board Design Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Rubinov, Paul; /Fermilab

    2005-04-01

    This document describes the design of the 2nd iteration of the Analog Front End Board (AFEII), which has the function of receiving charge signals from the Central Fiber Tracker (CFT) and providing digital hit pattern and charge amplitude information from those charge signals. This second iteration is intended to address limitations of the current AFE (referred to as AFEI in this document). These limitations become increasingly deleterious to the performance of the Central Fiber Tracker as instantaneous luminosity increases. The limitations are inherent in the design of the key front end chips on the AFEI board (the SVXIIe and the SIFT) and the architecture of the board itself. The key limitations of the AFEI are: (1) SVX saturation; (2) Discriminator to analog readout cross talk; (3) Tick to tick pedestal variation; and (4) Channel to channel pedestal variation. The new version of the AFE board, AFEII, addresses these limitations by use of a new chip, the TriP-t and by architectural changes, while retaining the well understood and desirable features of the AFEI board.

  10. Biomechanics of front and back squat exercises

    Energy Technology Data Exchange (ETDEWEB)

    Braidot, A A [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Brusa, M H [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Lestussi, F E [Laboratorio de Biomecanica FI-UNER. Ruta 11 Km 10 Oro Verde Entre Rios (Argentina); Parera, G P [Licenciatura en KinesiologIa y FisiatrIa Universidad Abierta Interamericana. Sede Regional Rosario (Argentina)

    2007-11-15

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0 deg. to 50 deg. because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  11. Internal waves and temperature fronts on slopes

    Directory of Open Access Journals (Sweden)

    S. A. Thorpe

    Full Text Available Time series measurements from an array of temperature miniloggers in a line at constant depth along the sloping boundary of a lake are used to describe the `internal surf zone' where internal waves interact with the sloping boundary. More small positive temperature time derivatives are recorded than negative, but there are more large negative values than positive, giving the overall distribution of temperature time derivatives a small negative skewness. This is consistent with the internal wave dynamics; fronts form during the up-slope phase of the motion, bringing cold water up the slope, and the return flow may become unstable, leading to small advecting billows and weak warm fronts. The data are analysed to detect `events', periods in which the temperature derivatives exceed a set threshold. The speed and distance travelled by `events' are described. The motion along the slope may be a consequence of (a instabilities advected by the flow (b internal waves propagating along-slope or (c internal waves approaching the slope from oblique directions. The propagation of several of the observed 'events' can only be explained by (c, evidence that the internal surf zone has some, but possibly not all, the characteristics of the conventional 'surface wave' surf zone, with waves steepening as they approach the slope at oblique angles.

    Key words. Oceanography: general (benthic boundary layers; limnology, Oceanography: physical (internal and inertial waves

  12. Universal Millimeter-Wave Radar Front End

    Science.gov (United States)

    Perez, Raul M.

    2010-01-01

    A quasi-optical front end allows any arbitrary polarization to be transmitted by controlling the timing, amplitude, and phase of the two input ports. The front end consists of two independent channels horizontal and vertical. Each channel has two ports transmit and receive. The transmit signal is linearly polarized so as to pass through a periodic wire grid. It is then propagated through a ferrite Faraday rotator, which rotates the polarization state 45deg. The received signal is propagated through the Faraday rotator in the opposite direction, undergoing a further 45 of polarization rotation due to the non-reciprocal action of the ferrite under magnetic bias. The received signal is now polarized at 90deg relative to the transmit signal. This signal is now reflected from the wire grid and propagated to the receive port. The horizontal and vertical channels are propagated through, or reflected from, another wire grid. This design is an improvement on the state of the art in that any transmit signal polarization can be chosen in whatever sequence desired. Prior systems require switching of the transmit signal from the amplifier, either mechanically or by using high-power millimeter-wave switches. This design can have higher reliability, lower mass, and more flexibility than mechanical switching systems, as well as higher reliability and lower losses than systems using high-power millimeter-wave switches.

  13. Travelling fronts in stochastic Stokes’ drifts

    KAUST Repository

    Blanchet, Adrien

    2008-10-01

    By analytical methods we study the large time properties of the solution of a simple one-dimensional model of stochastic Stokes\\' drift. Semi-explicit formulae allow us to characterize the behaviour of the solutions and compute global quantities such as the asymptotic speed of the center of mass or the effective diffusion coefficient. Using an equivalent tilted ratchet model, we observe that the speed of the center of mass converges exponentially to its limiting value. A diffuse, oscillating front attached to the center of mass appears. The description of the front is given using an asymptotic expansion. The asymptotic solution attracts all solutions at an algebraic rate which is determined by the effective diffusion coefficient. The proof relies on an entropy estimate based on homogenized logarithmic Sobolev inequalities. In the travelling frame, the macroscopic profile obeys to an isotropic diffusion. Compared with the original diffusion, diffusion is enhanced or reduced, depending on the regime. At least in the limit cases, the rate of convergence to the effective profile is always decreased. All these considerations allow us to define a notion of efficiency for coherent transport, characterized by a dimensionless number, which is illustrated on two simple examples of travelling potentials with a sinusoidal shape in the first case, and a sawtooth shape in the second case. © 2008 Elsevier B.V. All rights reserved.

  14. Biomechanics of front and back squat exercises

    Science.gov (United States)

    Braidot, A. A.; Brusa, M. H.; Lestussi, F. E.; Parera, G. P.

    2007-11-01

    Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0° to 50° because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

  15. An island in front of Izola

    Directory of Open Access Journals (Sweden)

    Franci Steinman

    2002-01-01

    Full Text Available Maritime construction in front of Izola restitutes an enriched former state. The island is positioned in a place where there are no legal regimes enforced by the state or local community. Legal regimes that determine the exploitation of water rights and limitations (management, exploitation, use can actually limit all. Therefore their synthesis has to be the starting point for analysing the harmony of present uses and for planning future uses of the sea and coastal area. For example the aquatorium of the shellfish mariculture positioned in the Strunjan Bay without adequate analysis of the prevailing conditions is causing conflicts of uses, unacceptable limiting of general use of the sea and prohibitive limitations in neighbouring areas. The analysis done for the island in front of Izola shows that there are no such consequences. Only uses in the public interest were proposed, since when assessing suitability first public and then common interests where considered, possible specific (e.g. entrepreneurial uses were permitted only if the afore mentioned weren’t obstructed. Thus integral management of the coastal area was enabled, with respect to functional ties between the land and sea.

  16. The ALICE TPC front end electronics

    CERN Document Server

    Musa, L; Bialas, N; Bramm, R; Campagnolo, R; Engster, Claude; Formenti, F; Bonnes, U; Esteve-Bosch, R; Frankenfeld, Ulrich; Glässel, P; Gonzales, C; Gustafsson, Hans Åke; Jiménez, A; Junique, A; Lien, J; Lindenstruth, V; Mota, B; Braun-Munzinger, P; Oeschler, H; Österman, L; Renfordt, R E; Ruschmann, G; Röhrich, D; Schmidt, H R; Stachel, J; Soltveit, A K; Ullaland, K

    2004-01-01

    In this paper we present the front end electronics for the time projection chamber (TPC) of the ALICE experiment. The system, which consists of about 570000 channels, is based on two basic units: (a) an analogue ASIC (PASA) that incorporates the shaping-amplifier circuits for 16 channels; (b) a mixed-signal ASIC (ALTRO) that integrates 16 channels, each consisting of a 10-bit 25-MSPS ADC, the baseline subtraction, tail cancellation filter, zero suppression and multi-event buffer. The complete readout chain is contained in front end cards (FEC), with 128 channels each, connected to the detector by means of capton cables. A number of FECs (up to 25) are controlled by a readout control unit (RCU), which interfaces the FECs to the data acquisition (DAQ), the trigger, and the detector control system (DCS) . A function of the final electronics (1024 channels) has been characterized in a test that incorporates a prototype of the ALICE TPC as well as many other components of the final set-up. The tests show that the ...

  17. Active elastic dimers: Cells moving on rigid tracks

    Science.gov (United States)

    Lopez, J. H.; Das, Moumita; Schwarz, J. M.

    2014-09-01

    Experiments suggest that the migration of some cells in the three-dimensional extracellular matrix bears strong resemblance to one-dimensional cell migration. Motivated by this observation, we construct and study a minimal one-dimensional model cell made of two beads and an active spring moving along a rigid track. The active spring models the stress fibers with their myosin-driven contractility and α-actinin-driven extendability, while the friction coefficients of the two beads describe the catch and slip-bond behaviors of the integrins in focal adhesions. In the absence of active noise, net motion arises from an interplay between active contractility (and passive extendability) of the stress fibers and an asymmetry between the front and back of the cell due to catch-bond behavior of integrins at the front of the cell and slip-bond behavior of integrins at the back. We obtain reasonable cell speeds with independently estimated parameters. We also study the effects of hysteresis in the active spring, due to catch-bond behavior and the dynamics of cross linking, and the addition of active noise on the motion of the cell. Our model highlights the role of α-actinin in three-dimensional cell motility and does not require Arp2/3 actin filament nucleation for net motion.

  18. Web-based DAQ systems: connecting the user and electronics front-ends

    Science.gov (United States)

    Lenzi, Thomas

    2016-12-01

    Web technologies are quickly evolving and are gaining in computational power and flexibility, allowing for a paradigm shift in the field of Data Acquisition (DAQ) systems design. Modern web browsers offer the possibility to create intricate user interfaces and are able to process and render complex data. Furthermore, new web standards such as WebSockets allow for fast real-time communication between the server and the user with minimal overhead. Those improvements make it possible to move the control and monitoring operations from the back-end servers directly to the user and to the front-end electronics, thus reducing the complexity of the data acquisition chain. Moreover, web-based DAQ systems offer greater flexibility, accessibility, and maintainability on the user side than traditional applications which often lack portability and ease of use. As proof of concept, we implemented a simplified DAQ system on a mid-range Spartan6 Field Programmable Gate Array (FPGA) development board coupled to a digital front-end readout chip. The system is connected to the Internet and can be accessed from any web browser. It is composed of custom code to control the front-end readout and of a dual soft-core Microblaze processor to communicate with the client.

  19. Factors affecting front line staff acceptance of telehealth technologies: a mixed-method systematic review.

    Science.gov (United States)

    Brewster, Liz; Mountain, Gail; Wessels, Bridgette; Kelly, Ciara; Hawley, Mark

    2014-01-01

    To synthesize qualitative and quantitative evidence of front-line staff acceptance of the use of telehealth technologies for the management of Chronic Obstructive Pulmonary Disease and Chronic Heart Failure. The implementation of telehealth at scale is a governmental priority in countries including the UK, USA and Canada, but little research has been conducted to analyse the impact of implementation on front-line nursing staff. Six relevant data bases were searched between 2000-2012. Mixed-method systematic review including all study designs. Centre for Reviews and Dissemination approach with thematic analysis and narrative synthesis of results. Fourteen studies met the review inclusion criteria; 2 quantitative surveys, 2 mixed-method studies and 10 using qualitative methods, including focus groups, interviews, document analysis and observations. Identified factors affecting staff acceptance centred on the negative impact of service change, staff-patient interaction, credibility and autonomy, and technical issues. Studies often contrasted staff and patient perspectives, and data about staff acceptance were collected as part of a wider study, rather than being the focus of data collection, meaning data about staff acceptance were limited. If telehealth is to be implemented, studies indicate that the lack of acceptance of this new way of working may be a key barrier. However, recommendations have not moved beyond barrier identification to recognizing solutions that might be implemented by front-line staff. Such solutions are imperative if future roll-out of telehealth technologies is to be successfully achieved. © 2013 John Wiley & Sons Ltd.

  20. Dark matter. A light move

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Muenchen Univ. (Germany). Arnold Sommerfeld Center; Max-Planck-Institut fuer Physik, Muenchen (Germany); Doebrich, Babette [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-11-15

    This proceedings contribution reports from the workshop Dark Matter - a light move, held at DESY in Hamburg in June 2013. Dark Matter particle candidates span a huge parameter range. In particular, well motivated candidates exist also in the sub-eV mass region, for example the axion. Whilst a plethora of searches for rather heavy Dark Matter particles exists, there are only very few experiments aimed at direct detection of sub-eV Dark Matter to this date. The aim of our workshop was to discuss if and how this could be changed in the near future.

  1. The Effects of Hearing Impairment, Age, and Hearing Aids on the Use of Self-Motion for Determining Front/Back Location.

    Science.gov (United States)

    Brimijoin, W Owen; Akeroyd, Michael A

    2016-07-01

    There are two cues that listeners use to disambiguate the front/back location of a sound source: high-frequency spectral cues associated with the head and pinnae, and self-motion-related binaural cues. The use of these cues can be compromised in listeners with hearing impairment and users of hearing aids. To determine how age, hearing impairment, and the use of hearing aids affect a listener's ability to determine front from back based on both self-motion and spectral cues. We used a previously published front/back illusion: signals whose physical source location is rotated around the head at twice the angular rate of the listener's head movements are perceptually located in the opposite hemifield from where they physically are. In normal-hearing listeners, the strength of this illusion decreases as a function of low-pass filter cutoff frequency, this is the result of a conflict between spectral cues and dynamic binaural cues for sound source location. The illusion was used as an assay of self-motion processing in listeners with hearing impairment and users of hearing aids. We recruited 40 hearing-impaired participants, with an average age of 62 yr. The data for three listeners were discarded because they did not move their heads enough during the experiment. Listeners sat at the center of a ring of 24 loudspeakers, turned their heads back and forth, and used a wireless keypad to report the front/back location of statically presented signals and of dynamically moving signals with illusory locations. Front/back accuracy for static signals, the strength of front/back illusions, and minimum audible movement angle were measured for each listener in each condition. All measurements were made in each listener both aided and unaided. Hearing-impaired listeners were less accurate at front/back discrimination for both static and illusory conditions. Neither static nor illusory conditions were affected by high-frequency content. Hearing aids had heterogeneous effects from

  2. Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.; /Costa Rica U.

    2012-02-16

    Light-Front Holography is one of the most remarkable features of the AdS/CFT correspondence. In spite of its present limitations it provides important physical insights into the nonperturbative regime of QCD and its transition to the perturbative domain. This novel framework allows hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound-state wavefunctions, and thus the fall-off as a function of the invariant mass of the constituents. The soft-wall holographic model modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics - a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions projected on the free Fock basis provides the complete set of valence and non-valence light-front Fock state wavefunctions {Psi}{sub n/H} (x{sub i}, k{sub {perpendicular}i}, {lambda}{sub i}) which describe the hadron's momentum and spin distributions needed to compute the direct measures of hadron structure at the quark and gluon level, such as elastic and transition form factors, distribution amplitudes, structure functions, generalized parton distributions and transverse

  3. The CMS Tracker Readout Front End Driver

    CERN Document Server

    Foudas, C.; Ballard, D.; Church, I.; Corrin, E.; Coughlan, J.A.; Day, C.P.; Freeman, E.J.; Fulcher, J.; Gannon, W.J.F.; Hall, G.; Halsall, R.N.J.; Iles, G.; Jones, J.; Leaver, J.; Noy, M.; Pearson, M.; Raymond, M.; Reid, I.; Rogers, G.; Salisbury, J.; Taghavi, S.; Tomalin, I.R.; Zorba, O.

    2004-01-01

    The Front End Driver, FED, is a 9U 400mm VME64x card designed for reading out the Compact Muon Solenoid, CMS, silicon tracker signals transmitted by the APV25 analogue pipeline Application Specific Integrated Circuits. The FED receives the signals via 96 optical fibers at a total input rate of 3.4 GB/sec. The signals are digitized and processed by applying algorithms for pedestal and common mode noise subtraction. Algorithms that search for clusters of hits are used to further reduce the input rate. Only the cluster data along with trigger information of the event are transmitted to the CMS data acquisition system using the S-LINK64 protocol at a maximum rate of 400 MB/sec. All data processing algorithms on the FED are executed in large on-board Field Programmable Gate Arrays. Results on the design, performance, testing and quality control of the FED are presented and discussed.

  4. Additional shielding in front of M2

    CERN Document Server

    Schmidt, B

    2013-01-01

    This note presents studies on possibilities to improve the shielding in front of M2 in order to reduce occupancy of the hottest areas of the Muon System and to mitigate the dead-time problem. Two places for installing additional shielding have been considered: behind HCAL, in place of the PMTs and their bases for the readout, and inside ECAL, in place of the innermost modules of the calorimeter. Studies on the additional shielding inside ECAL have been done for the complementarity of the research rather than for practical purpose due negative effects on the physics. Various studies have been carried out and different configurations of shielding in terms of dimensions and materials have been tested using MC simulations. Moreover the correlation between hits was studied by analysing angles of the tracks passing through M2.

  5. The front-end electronics for LHCb calorimeters

    CERN Document Server

    Breton, D

    2002-01-01

    For the readout of the calorimeters of the LHCb experiment at CERN, specific front-end electronics have been designed. In particular, three different front-end analog chips were studied respectively for the ECAL/HCAL, preshower and scintillator pad detector. We will present the three front-end electronic chains, point out their specific requirements together with their common purpose, and describe the corresponding ASICs. (6 refs).

  6. MMIC front-ends for optical communication systems

    DEFF Research Database (Denmark)

    Petersen, Anders Kongstad

    1993-01-01

    Two different types of optical front-end MMIC amplifiers for a 2.5-Gb/s coherent heterodyne optical receiver are presented. A bandwidth of 6-12 GHz has been obtained for a tuned front-end and 3-13 GHz for a distributed front-end. An input noise current density of 5-15 pA/√Hz has been obtained for...

  7. Autonomous Landing on Moving Platforms

    KAUST Repository

    Mendoza Chavez, Gilberto

    2016-08-01

    This thesis investigates autonomous landing of a micro air vehicle (MAV) on a nonstationary ground platform. Unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs) are becoming every day more ubiquitous. Nonetheless, many applications still require specialized human pilots or supervisors. Current research is focusing on augmenting the scope of tasks that these vehicles are able to accomplish autonomously. Precise autonomous landing on moving platforms is essential for self-deployment and recovery of MAVs, but it remains a challenging task for both autonomous and piloted vehicles. Model Predictive Control (MPC) is a widely used and effective scheme to control constrained systems. One of its variants, output-feedback tube-based MPC, ensures robust stability for systems with bounded disturbances under system state reconstruction. This thesis proposes a MAV control strategy based on this variant of MPC to perform rapid and precise autonomous landing on moving targets whose nominal (uncommitted) trajectory and velocity are slowly varying. The proposed approach is demonstrated on an experimental setup.

  8. White-fronted Goose Telementry, 1998-2000 [ds330

    Data.gov (United States)

    California Department of Resources — Using radio-telemetry, greater white-fronted geese (Anser albifrons frontalis) distribution and movements during winter in Central California were determined during...

  9. Convection induced by thermal gradients on thin reaction fronts

    Science.gov (United States)

    Ruelas Paredes, David R. A.; Vasquez, Desiderio A.

    2017-09-01

    We present a thin front model for the propagation of chemical reaction fronts in liquids inside a Hele-Shaw cell or porous media. In this model we take into account density gradients due to thermal and compositional changes across a thin interface. The front separating reacted from unreacted fluids evolves following an eikonal relation between the normal speed and the curvature. We carry out a linear stability analysis of convectionless flat fronts confined in a two-dimensional rectangular domain. We find that all fronts are stable to perturbations of short wavelength, but they become unstable for some wavelengths depending on the values of compositional and thermal gradients. If the effects of these gradients oppose each other, we observe a range of wavelengths that make the flat front unstable. Numerical solutions of the nonlinear model show curved fronts of steady shape with convection propagating faster than flat fronts. Exothermic fronts increase the temperature of the fluid as they propagate through the domain. This increment in temperature decreases with increasing speed.

  10. Light-front holography: a first approximation to QCD.

    Science.gov (United States)

    de Téramond, Guy F; Brodsky, Stanley J

    2009-02-27

    Starting from the Hamiltonian equation of motion in QCD, we identify an invariant light-front coordinate zeta which allows the separation of the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schrödinger equation for QCD which determines the eigenspectrum and the light-front wave functions of hadrons for general spin and orbital angular momentum. This light-front wave equation is equivalent to the equations of motion which describe the propagation of spin-J modes on anti-de Sitter (AdS) space.

  11. Moving Model Test of High-Speed Train Aerodynamic Drag Based on Stagnation Pressure Measurements

    Science.gov (United States)

    Yang, Mingzhi; Du, Juntao; Huang, Sha; Zhou, Dan

    2017-01-01

    A moving model test method based on stagnation pressure measurements is proposed to measure the train aerodynamic drag coefficient. Because the front tip of a high-speed train has a high pressure area and because a stagnation point occurs in the center of this region, the pressure of the stagnation point is equal to the dynamic pressure of the sensor tube based on the obtained train velocity. The first derivation of the train velocity is taken to calculate the acceleration of the train model ejected by the moving model system without additional power. According to Newton’s second law, the aerodynamic drag coefficient can be resolved through many tests at different train speeds selected within a relatively narrow range. Comparisons are conducted with wind tunnel tests and numerical simulations, and good agreement is obtained, with differences of less than 6.1%. Therefore, the moving model test method proposed in this paper is feasible and reliable. PMID:28095441

  12. Moving Model Test of High-Speed Train Aerodynamic Drag Based on Stagnation Pressure Measurements.

    Directory of Open Access Journals (Sweden)

    Mingzhi Yang

    Full Text Available A moving model test method based on stagnation pressure measurements is proposed to measure the train aerodynamic drag coefficient. Because the front tip of a high-speed train has a high pressure area and because a stagnation point occurs in the center of this region, the pressure of the stagnation point is equal to the dynamic pressure of the sensor tube based on the obtained train velocity. The first derivation of the train velocity is taken to calculate the acceleration of the train model ejected by the moving model system without additional power. According to Newton's second law, the aerodynamic drag coefficient can be resolved through many tests at different train speeds selected within a relatively narrow range. Comparisons are conducted with wind tunnel tests and numerical simulations, and good agreement is obtained, with differences of less than 6.1%. Therefore, the moving model test method proposed in this paper is feasible and reliable.

  13. Wave field synthesis of moving virtual sound sources with complex radiation properties.

    Science.gov (United States)

    Ahrens, Jens; Spors, Sascha

    2011-11-01

    An approach to the synthesis of moving virtual sound sources with complex radiation properties in wave field synthesis is presented. The approach exploits the fact that any stationary sound source of finite spatial extent radiates spherical waves at sufficient distance. The angular dependency of the radiation properties of the source under consideration is reflected by the amplitude and phase distribution on the spherical wave fronts. The sound field emitted by a uniformly moving monopole source is derived and the far-field radiation properties of the complex virtual source under consideration are incorporated in order to derive a closed-form expression for the loudspeaker driving signal. The results are illustrated via numerical simulations of the synthesis of the sound field of a sample moving complex virtual source.

  14. Moving Model Test of High-Speed Train Aerodynamic Drag Based on Stagnation Pressure Measurements.

    Science.gov (United States)

    Yang, Mingzhi; Du, Juntao; Li, Zhiwei; Huang, Sha; Zhou, Dan

    2017-01-01

    A moving model test method based on stagnation pressure measurements is proposed to measure the train aerodynamic drag coefficient. Because the front tip of a high-speed train has a high pressure area and because a stagnation point occurs in the center of this region, the pressure of the stagnation point is equal to the dynamic pressure of the sensor tube based on the obtained train velocity. The first derivation of the train velocity is taken to calculate the acceleration of the train model ejected by the moving model system without additional power. According to Newton's second law, the aerodynamic drag coefficient can be resolved through many tests at different train speeds selected within a relatively narrow range. Comparisons are conducted with wind tunnel tests and numerical simulations, and good agreement is obtained, with differences of less than 6.1%. Therefore, the moving model test method proposed in this paper is feasible and reliable.

  15. Assessing the Cartographic Visualization of Moving Objects ...

    African Journals Online (AJOL)

    Nowadays, there is a lot of interest in studying dynamic spatial phenomena. There are various dynamic phenomena in the world among which moving objects are worth exemplifying. Recently, moving objects are getting attention in database applications and in visualization. Moving objects are of two categories: individual ...

  16. 20 CFR 617.47 - Moving allowance.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Moving allowance. 617.47 Section 617.47... FOR WORKERS UNDER THE TRADE ACT OF 1974 Relocation Allowances § 617.47 Moving allowance. (a) Computation. The amount of a moving allowance payable under § 617.45(a)(2) shall be 90 percent of the total of...

  17. Front contact solar cell with formed electrically conducting layers on the front side and backside

    Science.gov (United States)

    Cousins, Peter John

    2012-06-26

    A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell.

  18. Front propagation in the bromate-sulfite-ferrocyanide-aluminum (III) system: Autocatalytic front in a buffer system

    Science.gov (United States)

    Kovacs, Klara; Leda, Marcin; Vanag, Vladimir K.; Epstein, Irving R.

    2010-06-01

    We study the propagation of pH fronts in a narrow, pseudo-one-dimensional strip of gel containing bromate, sulfite, ferrocyanide and aluminum ions. The front propagation speed v decreases with [ Al 3+] as 1/v=1/v0+c[Al], where c is a constant. We determine the diffusion coefficients of protons and ferricyanide ions and find that Al(OH) 3 loaded in agarose or acrylamide gels binds protons reversibly, thereby slowing the propagating fronts without significantly affecting the diffusion of ferricyanide ions. We present a model that qualitatively reproduces the experimental behavior, and we suggest some general principles governing autocatalytic fronts in buffered systems.

  19. Moving Horizon Estimation and Control

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp

    as the corresponding sensitivity equations are discussed. Chapter 6 summarizes the main contribution of this thesis. It briefly discusses the pros and cons of using the extended linear quadratic control framework for solution of deterministic optimal control problems. Appendices. Appendix A demonstrates how quadratic...... successful and applied methodology beyond PID-control for control of industrial processes. The main contribution of this thesis is introduction and definition of the extended linear quadratic optimal control problem for solution of numerical problems arising in moving horizon estimation and control....... An efficient structure-employing methodology for solution of the extended linear quadratic optimal control problem is provided and it is discussed how this solution is employed in solution of constrained model predictive control problems as well as in the solution of nonlinear optimal control and estimation...

  20. AHP 21: Review: Moving Mountains

    Directory of Open Access Journals (Sweden)

    William B. Noseworthy

    2012-12-01

    Full Text Available Moving Mountains stands out among recent discussions of the Southeast Asian Highlands, drawing from twelve contributors with extensive field experience living and working in locales closed to nonCommunist academics between 1945 and 1990 (3. The authors' methodologies focus on the anthropological approach of participant observation combined with oral history. Previously, substantial research had been confined to the experience of "hill tribes" in Northern Thailand (11, unless one gained access to the massive collections of French language research under the École Française d'Extrême Orient (EFEO or the Société Asiatique (SA, both in Paris. As such, this volume's contributors are able to ring out the voices of Southeast Asian Massif populations in a way that demonstrates a mindful assembly of research, while carefully narrating a more complex view of the region than that presented by Scott's (2009:22 "zones of refuge." ...

  1. Observations of a tidal intrusion front in a tidal channel

    Science.gov (United States)

    Lu, Shasha; Xia, Xiaoming; Thompson, Charlie E. L.; Cao, Zhenyi; Liu, Yifei

    2017-11-01

    A visible front indicated by a surface colour change, and sometimes associated with foam or debris lines, was observed in a tidal channel during neap tide. This is an example of a tidal intrusion front occurring in the absence of sudden topographical changes or reversing flows, typically reported to be associated with such fronts. Detailed Acoustic Doppler Current Profiler and conductivity/temperature/depth measurements were taken on repeated transects both with fronts apparent and with fronts absent. The results indicated that the front occurred as a result of stratification, which was sustained by the buoyancy flux and the weak tide-induced mixing during neap ebb tide. The stronger tide-induced mixing during spring tide restrained stratification, leading to the absence of a front. The mechanism of the frontogenesis was the density gradient between the stratified water formed during neap ebb tide, and the more mixed seawater during neap flood tide; thus, the water on the landward (southwestern) side of the front was stratified, and that on the seaward side (northeastern) of the front was vertically well mixed. Gradient Richardson number estimates suggest that the flow between the stratified and mixed water was near the threshold 0.25 for shear instability. Meanwhile, the density gradient would provide an initial baroclinic contribution to velocity convergence, which is indicated by the accumulation of buoyant matter such as foam, grass, and debris into a sharply defined line along the surface. The front migrates with the flood current, with a local maximum towards the eastern side of the channel, leading to an asymmetrical shape with the eastern side of the front driven further into the Tiaozhoumen tidal channel.

  2. Detecting and tracking moving humans from a moving vehicle

    Science.gov (United States)

    Bodt, Barry A.; Camden, Richard

    2008-04-01

    In September 2007 the Army Research Laboratory (ARL) Robotics Collaborative Technology Alliance (CTA) conducted an assessment of multiple pedestrian detection algorithms based upon LADAR or video sensor data. Eight detection algorithms developed by the Robotics CTA member organizations, including ARL, were assessed in an experiment conducted by the National Institute of Science & Technology (NIST) and ARL to determine the probability of detection/misclassification and false alarm rate as a function of vehicle speed, degree of environmental clutter, and pedestrian speeds. The study is part of an ongoing investigation of safe operations for unmanned ground vehicles. This assessment marked the first time in this program that human movers acted as targets for detection from a moving vehicle. A focus of the study was to choreograph repeatable human movement scenarios relative to the movement of the vehicle. The resulting data is intended to support comparative analysis across treatment conditions and to allow developers to examine performance with respect to specific detection and tracking events. Events include humans advancing and retreating from the vehicle at different angles, humans crossing paths in close proximity and occlusion situations where sight to the mover from the sensor system is momentarily lost. A detailed operational procedure ensured repeatable human movement with independent ground truth supplied by a NIST ultra wideband wireless tracking system. Post processing and statistical analysis reconciled the tracking algorithm results with the NIST ground truth. We will discuss operational considerations and results.

  3. Thermal front propagation in variable aperture fracture–matrix ...

    Indian Academy of Sciences (India)

    Keywords. Thermal front; variable aperture; rock-matrix; geothermal reservoir; numerical model, liquid dominated. Abstract. A numerical study on the effect of complex fracture aperture geometry on propagation of thermal front in a coupled single fracture-matrix system has been carried out. Sinusoidal and logarithmic ...

  4. A programmable front-end system for arrays of bolometers

    Science.gov (United States)

    Alessandrello, A.; Brofferio, C.; Bucci, C.; Cremonesi, O.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Perego, M.; Pessina, G.; Pirro, S.; Previtali, E.; Vanzini, M.

    2000-04-01

    We report on a new front-end system developed to readout an array of large mass bolometers. The front-end allows setting all the necessary parameters for each detector by remote control. A special circuit, also fired remotely, has been developed in order to adjust the output voltage, allowing the DC coupling to the detector.

  5. A programmable front-end system for arrays of bolometers

    Energy Technology Data Exchange (ETDEWEB)

    Alessandrello, A.; Brofferio, C.; Bucci, C.; Cremonesi, O.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Perego, M.; Pessina, G. E-mail: pessina@mi.infn.it; Pirro, S.; Previtali, E.; Vanzini, M

    2000-04-07

    We report on a new front-end system developed to readout an array of large mass bolometers. The front-end allows setting all the necessary parameters for each detector by remote control. A special circuit, also fired remotely, has been developed in order to adjust the output voltage, allowing the DC coupling to the detector.

  6. Stability of reaction fronts in random walk simulations

    NARCIS (Netherlands)

    Nagy, Noemi; Izsak, F.

    A model of propagating reaction fronts is given for simple autocatalytic reactions and the stability of the propagating reaction fronts are studied in several numerical experiments. The corresponding random walk simulations - extending of a recent algorithm - make possible the simultaneous treatment

  7. An Attempt to Simulate Historic Front Variations of Nigardsbreen, Norway

    NARCIS (Netherlands)

    Oerlemans, J.

    1986-01-01

    Nigardsbreen (Norway) is one of the very few highlatitude glaciers from which a long record of front positions is known (starting in the beginning of the 18th century). In this paper a dynamic glacier model is used to investigate the possible causes of the observed front variations. These

  8. Desirable forest structures for a restored Front Range

    Science.gov (United States)

    Yvette L. Dickinson; Rob Addington; Greg Aplet; Mike Babler; Mike Battaglia; Peter Brown; Tony Cheng; Casey Cooley; Dick Edwards; Jonas Feinstein; Paula Fornwalt; Hal Gibbs; Megan Matonis; Kristen Pelz; Claudia Regan

    2014-01-01

    As part of the federal Collaborative Forest Landscape Restoration Program administered by the US Forest Service, the Colorado Front Range Collaborative Forest Landscape Restoration Project (FR-CFLRP, a collaborative effort of the Front Range Roundtable1 and the US Forest Service) is required to define desired conditions for lower montane ponderosa pine (Pinus ponderosa...

  9. Chemotaxis : signalling modules join hands at front and tail

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Devreotes, Peter N.

    2004-01-01

    Chemotaxis is the result of a refined interplay among various intracellular molecules that process spatial and temporal information. Here we present a modular scheme of the complex interactions between the front and the back of cells that allows them to navigate. First, at the front of the cell,

  10. Cost of pedestrian and bicycle accidents involving car front ends.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Huijbers, J.J.W.

    1995-01-01

    A cost study has been carried out, based on Dutch insurance data of payments to victims (pedestrians and cyclists) of collisions against car front ends. The results of this study will be used for a cost-benefit analysis of a proposed amendment (a series of car front end crash tests) to the existing

  11. Ambient-light-absorbing screen for front projection

    Science.gov (United States)

    Hilborn, E. H.

    1970-01-01

    Screen permits front surface projection of collimated light beam under conditions of high extraneous illumination. Screen has high reflective efficiency over any desired viewing area. Its optical properties are maintained when moisture droplets are present on the external front planar surface. Surface is easily cleaned and maintained.

  12. MMIC tuned front-end for a coherent optical receiver

    DEFF Research Database (Denmark)

    Petersen, Anders Kongstad; Jagd, A. M.; Ebskamp, F.

    1993-01-01

    A low-noise transformer tuned optical front-end for a coherent optical receiver is described. The front-end is based on a GaInAs/InP p-i-n photodiode and a full custom designed GaAs monolithic microwave integrated circuit (MMIC). The measured equivalent input noise current density is between 5-16 p...

  13. The effects of hearing impairment, age, and hearing aids on the use of self motion for determining front/back location

    Science.gov (United States)

    Owen Brimijoin, W.; Akeroyd, Michael A.

    2016-01-01

    Background There are two cues that listeners use to disambiguate the front/back location of a sound source: high-frequency spectral cues associated with the head and pinnae, and self-motion-related binaural cues. The use of these cues can be compromised in listeners with hearing impairment and users of hearing aids. Purpose To determine how age, hearing impairment, and the use of hearing aids affects a listener’s ability to determine front from back based on both self motion and spectral cues. Research Design We utilized a previously published front/back illusion: signals whose physical source location is rotated around the head at twice the angular rate of the listener’s head movements are perceptually located in the opposite hemifield from where they physically are. In normal hearing listeners the strength of this illusion decreases as a function of low-pass filter cutoff frequency; this is the result of a conflict between spectral cues and dynamic binaural cues for sound source location. The illusion was used as an assay of self-motion processing in listeners with hearing impairment and users of hearing aids. Study Sample We recruited 40 hearing impaired subjects, with an average age of 62 years. The data for three listeners were discarded because they did not move their heads enough during the experiment. Data Collection and Analysis Listeners sat at the center of a ring of 24 loudspeakers, turned their heads back and forth, and used a wireless keypad to report the front/back location of statically presented signals and of dynamically moving signals with illusory locations. Front/back accuracy for static signals, the strength of front/back illusions, and minimum audible movement angle was measured for each listener in each condition. All measurements were made in each listener both aided and unaided. Results Hearing impaired listeners were less accurate at front/back discrimination for both static and illusory conditions. Neither static nor illusory

  14. Fronts and Thermohaline Structure of the Brazil Current Confluence System

    Science.gov (United States)

    Severov, Dimitri

    and Thermohaline Structure of the Brazil Current Confluence System (BCCS) are stud-ied from climatic data, "Marathon Exp. Leg.8, 1984"data, and two Sea surface temperature (SST) data bases: "Meteor satellite"(1989-1994) and "ds277-Reynolds" (1981-2000).The South Atlantic Central Water (SACW) is divided in two main types: tropical (TW) and subtropical water (ST). Water masses, fronts, inter-frontal and frontal zones are analysed and classified: a) the water masses: Tropical Low-Salinity Water, Tropical Surface Water, Tropical Tropospheric Water, Subtropical Low-Salinity Water, Subtropical Surface Water, Subtropical Tropospheric Water. T,S characteristics of intermediate, deep and bottom water defined by different authors are confirmed and completed; b) the Inter-frontal Zones: Tropical/Brazil Current Zone, Sub-tropical Zone and Subantarctic Zone; c) the Frontal Zones: Subtropical, Subantarctic and Polar, and d) the Fronts: Subtropical Front of the Brazil Current, Principal Subtropical Front, North Subtropical Front, Subtropical Surface Front, South Subtropical Front, Subantarctic Surface Front, Subantarctic Front and Polar Front. Several stable T-S relationships are found below the friction layer and at the Fronts. The maximum gradient of the oceanographic characteris-tics occurs at the Brazil Current Front, which can be any of the subtropical fronts, depending on season. Minimum mean depth of the pycnocline coincides with the fronts of the BCCS, indicating the paths of low-salinity shelf waters into the open ocean. D. N. Severov (a) , V. Pshennikov (b) and A.V. Remeslo (c) a -Sección Oceanologé Facultad de Ciencia, Universidad de la Republica, Igué 4225, 11400 ıa, a Montevideo, Uruguay. Tel. (598-2) 525-8618, Fax (598-2) 525-8617, mail: dima@fcien.edu.uy b -Instituto de Física, Facultad de Ciencias, Universidad de la Republica, Igué 4225, 11400 Mon-a tevideo, Uruguay, mail: seva@fisica.edu.uy c -Atlantic Research Inst. For Fisheries Oceanology (Atlant

  15. Pareto-front shape in multiobservable quantum control

    Science.gov (United States)

    Sun, Qiuyang; Wu, Re-Bing; Rabitz, Herschel

    2017-03-01

    Many scenarios in the sciences and engineering require simultaneous optimization of multiple objective functions, which are usually conflicting or competing. In such problems the Pareto front, where none of the individual objectives can be further improved without degrading some others, shows the tradeoff relations between the competing objectives. This paper analyzes the Pareto-front shape for the problem of quantum multiobservable control, i.e., optimizing the expectation values of multiple observables in the same quantum system. Analytic and numerical results demonstrate that with two commuting observables the Pareto front is a convex polygon consisting of flat segments only, while with noncommuting observables the Pareto front includes convexly curved segments. We also assess the capability of a weighted-sum method to continuously capture the points along the Pareto front. Illustrative examples with realistic physical conditions are presented, including NMR control experiments on a 1H-13C two-spin system with two commuting or noncommuting observables.

  16. Light-Front Holography: A First Approximation to QCD

    Energy Technology Data Exchange (ETDEWEB)

    de Teramond, Guy F.; Brodsky, Stanley J.

    2008-10-03

    Starting from the Hamiltonian equation of motion in QCD, we identify an invariant light-front coordinate {zeta} which allows the separation of the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single variable light-front Schroedinger equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. This light-front wave equation is equivalent to the equations of motion which describe the propagation of spin-J modes on anti-de Sitter (AdS) space. This allows us to establish formally a gauge/gravity correspondence between an effective gravity theory defined on AdS5 and light front QCD.

  17. Design of Laboratory Experiments to Study Photoionization Fronts

    Science.gov (United States)

    Gray, William James; Davis, Josh; Drake, R. Paul

    2017-06-01

    Here we present the theoretical foundation for a laboratory experiment to study photoionization fronts. Photoionization fronts play important roles in the formation and evolution of structure in the Universe. A properly designed experiment will have to control the recombination rate, electron impact ionization rate, and the initial thermal spectrum. We show that such an experiment can be designed, but requires the use of the largest high-energy-density laser facilities, such as Omega, Z, and NIF. We also show that prior experiments do not actually generate photoionization fronts, rather a heat front is produced by heat conductions. We show some initial simulation results of the current experimental design and characterize the ionization front.

  18. Nonvariational mechanism of front propagation: Theory and experiments.

    Science.gov (United States)

    Alvarez-Socorro, A J; Clerc, M G; González-Cortés, G; Wilson, M

    2017-01-01

    Multistable systems exhibit a rich front dynamics between equilibria. In one-dimensional scalar gradient systems, the spread of the fronts is proportional to the energy difference between equilibria. Fronts spreading proportionally to the energetic difference between equilibria is a characteristic of one-dimensional scalar gradient systems. Based on a simple nonvariational bistable model, we show analytically and numerically that the direction and speed of front propagation is led by nonvariational dynamics. We provide experimental evidence of nonvariational front propagation between different molecular orientations in a quasi-one-dimensional liquid-crystal light valve subjected to optical feedback. Free diffraction length allows us to control the variational or nonvariational nature of this system. Numerical simulations of the phenomenological model have quite good agreement with experimental observations.

  19. Front tracking for hyperbolic conservation laws

    CERN Document Server

    Holden, Helge

    2002-01-01

    Hyperbolic conservation laws are central in the theory of nonlinear partial differential equations and in science and technology. The reader is given a self-contained presentation using front tracking, which is also a numerical method. The multidimensional scalar case and the case of systems on the line are treated in detail. A chapter on finite differences is included. "It is already one of the few best digests on this topic. The present book is an excellent compromise between theory and practice. Students will appreciate the lively and accurate style." D. Serre, MathSciNet "I have read the book with great pleasure, and I can recommend it to experts as well as students. It can also be used for reliable and very exciting basis for a one-semester graduate course." S. Noelle, Book review, German Math. Soc. "Making it an ideal first book for the theory of nonlinear partial differential equations...an excellent reference for a graduate course on nonlinear conservation laws." M. Laforest, Comp. Phys. Comm.

  20. Front tracking for hyperbolic conservation laws

    CERN Document Server

    Holden, Helge

    2015-01-01

    This is the second edition of a well-received book providing the fundamentals of the theory hyperbolic conservation laws. Several chapters have been rewritten, new material has been added, in particular, a chapter on space dependent flux functions, and the detailed solution of the Riemann problem for the Euler equations. Hyperbolic conservation laws are central in the theory of nonlinear partial differential equations and in science and technology. The reader is given a self-contained presentation using front tracking, which is also a numerical method. The multidimensional scalar case and the case of systems on the line are treated in detail. A chapter on finite differences is included. From the reviews of the first edition: "It is already one of the few best digests on this topic. The present book is an excellent compromise between theory and practice. Students will appreciate the lively and accurate style." D. Serre, MathSciNet  "I have read the book with great pleasure, and I can recommend it to experts ...

  1. Pulse Front Tilt and Laser Plasma Acceleration

    Science.gov (United States)

    Mittelberger, Daniel; Thévenet, Maxence; Nakamura, Kei; Lehe, Remi; Gonsalves, Anthony; Benedetti, Carlo; Leemans, Wim

    2017-10-01

    Pulse front tilt (PFT) is potentially present in any CPA laser system, but its effects may be overlooked because spatiotemporal pulse characterization is considerably more involved than measuring only spatial or temporal profile. PFT is particularly important for laser plasma accelerators (LPA) because it influences electron beam injection and steering. In this work, experimental results from the BELLA Center will be presented that demonstrate the effect of optical grating misalignment and optical compression, resulting in PFT, on accelerator performance. Theoretical models of laser and electron beam steering will be introduced based on particle-in-cell simulations showing distortion of the plasma wake. Theoretical predictions will be compared with experiments and complimentary simulations, and tolerances on PFT and optical compressor alignment will be developed as a function of LPA performance requirements. This work was supported by the Office of High Energy Physics, Office of Science, US Department of Energy under Contract DE-AC02-05CH11231 and the National Science Foundation under Grant PHY-1415596.

  2. The Telecom Lab is moving

    CERN Multimedia

    IT Department

    2009-01-01

    As of 2nd March 2009, the Telecom Lab will move to Building 58 R-017. The Telecom Lab is the central point for all support questions regarding CERN mobile phone services (provision of SIM cards, requests for modifications of subscriptions, diagnostics for mobile phone problems, etc.). The opening hours as well as the contact details for the Telecom Lab remain unchanged: New location: Building 58 R-017 Opening hours: Every week day, from 11 a.m. to 12 a.m. Phone number: 72480 Email address: labo.telecom@cern.ch This change has no impact on support requests for mobile services. Users can still submit their requests concerning mobile phone subscriptions using the usual EDH form (https://edh.cern.ch/Document/GSM). The automatic message sent to inform users of their SIM card availability will be updated to indicate the new Telecom Lab location. You can find all information related to CERN mobile phone services at the following link: http://cern.ch/gsm CS Section - IT/CS group

  3. Moving forward with safety culture.

    Science.gov (United States)

    Weber, Michael

    2012-04-01

    Radiation safety and protection of people are shared goals of the Health Physics Society (HPS) and the U.S. Nuclear Regulatory Commission (NRC). A positive safety culture contributes to achieving radiation safety and protection of people, which are important to both the HPS and the NRC. Through unprecedented collaboration and engagement with diverse stakeholders, the NRC and the stakeholders developed a Safety Culture Policy Statement. The policy statement defines safety culture and describes the traits of a positive safety culture. Consideration of both safety and security issues and the interface of safety and security are underlying principles that support the policy. Examination of significant events, both within the nuclear industry and in society at large, illustrates how weaknesses in these traits can contribute to the occurrence and consequences of safety incidents, including serious injury and loss of life. With the policy statement in place, the NRC is moving forward with outreach and education about safety culture. Health physicists and other radiation safety specialists play an essential role in enhancing safety culture.

  4. Euphotic Zone Study moves forward

    Science.gov (United States)

    Denman, Kenneth

    The Global Ocean Euphotic Zone Study (GOEZS), a potential core program of the International Geosphere-Biosphere Programme (IGBP) being planned jointly with the Scientific Committee on Oceanic Research (SCOR), was recently given the go-ahead by IGBP's Scientific Committee to move on to the next level of developing its scientific program.The GOEZS program will focus on the coupled physical, biological, and chemical processes operating in the euphotic zone, which is the ocean surface layer where sufficient light penetrates for photosynthesis by phytoplankton to exceed their metabolic energy losses. The upper ocean is extremely important to understanding the atmosphereocean system because it mediates exchanges of heat, momentum, carbon dioxide, sulphur, and nitrogen between the atmosphere and the ocean interior. For the major greenhouse gas carbon dioxide for example, there is more carbon in the upper ocean than in the whole atmosphere. Essentially all carbon dioxide from the atmosphere that passes from the upper ocean to the ocean interior has been transformed chemically or biologically in the upper ocean. Moreover, the upper ocean is the site of all marine shipping and most recreation and industrial activity and contains the planktonic food chain and most fish stocks.

  5. Leadership in Moving Human Groups

    Science.gov (United States)

    Boos, Margarete; Pritz, Johannes; Lange, Simon; Belz, Michael

    2014-01-01

    How is movement of individuals coordinated as a group? This is a fundamental question of social behaviour, encompassing phenomena such as bird flocking, fish schooling, and the innumerable activities in human groups that require people to synchronise their actions. We have developed an experimental paradigm, the HoneyComb computer-based multi-client game, to empirically investigate human movement coordination and leadership. Using economic games as a model, we set monetary incentives to motivate players on a virtual playfield to reach goals via players' movements. We asked whether (I) humans coordinate their movements when information is limited to an individual group member's observation of adjacent group member motion, (II) whether an informed group minority can lead an uninformed group majority to the minority's goal, and if so, (III) how this minority exerts its influence. We showed that in a human group – on the basis of movement alone – a minority can successfully lead a majority. Minorities lead successfully when (a) their members choose similar initial steps towards their goal field and (b) they are among the first in the whole group to make a move. Using our approach, we empirically demonstrate that the rules of swarming behaviour apply to humans. Even complex human behaviour, such as leadership and directed group movement, follow simple rules that are based on visual perception of local movement. PMID:24699264

  6. The Front-End Readout as an Encoder IC for Magneto-Resistive Linear Scale Sensors.

    Science.gov (United States)

    Tran, Trong-Hieu; Chao, Paul Chang-Po; Chien, Ping-Chieh

    2016-09-02

    This study proposes a front-end readout circuit as an encoder chip for magneto-resistance (MR) linear scales. A typical MR sensor consists of two major parts: one is its base structure, also called the magnetic scale, which is embedded with multiple grid MR electrodes, while another is an "MR reader" stage with magnets inside and moving on the rails of the base. As the stage is in motion, the magnetic interaction between the moving stage and the base causes the variation of the magneto-resistances of the grid electrodes. In this study, a front-end readout IC chip is successfully designed and realized to acquire temporally-varying resistances in electrical signals as the stage is in motions. The acquired signals are in fact sinusoids and co-sinusoids, which are further deciphered by the front-end readout circuit via newly-designed programmable gain amplifiers (PGAs) and analog-to-digital converters (ADCs). The PGA is particularly designed to amplify the signals up to full dynamic ranges and up to 1 MHz. A 12-bit successive approximation register (SAR) ADC for analog-to-digital conversion is designed with linearity performance of ±1 in the least significant bit (LSB) over the input range of 0.5-2.5 V from peak to peak. The chip was fabricated by the Taiwan Semiconductor Manufacturing Company (TSMC) 0.35-micron complementary metal oxide semiconductor (CMOS) technology for verification with a chip size of 6.61 mm², while the power consumption is 56 mW from a 5-V power supply. The measured integral non-linearity (INL) is -0.79-0.95 LSB while the differential non-linearity (DNL) is -0.68-0.72 LSB. The effective number of bits (ENOB) of the designed ADC is validated as 10.86 for converting the input analog signal to digital counterparts. Experimental validation was conducted. A digital decoder is orchestrated to decipher the harmonic outputs from the ADC via interpolation to the position of the moving stage. It was found that the displacement measurement error is within

  7. The Front-End Readout as an Encoder IC for Magneto-Resistive Linear Scale Sensors

    Directory of Open Access Journals (Sweden)

    Trong-Hieu Tran

    2016-09-01

    Full Text Available This study proposes a front-end readout circuit as an encoder chip for magneto-resistance (MR linear scales. A typical MR sensor consists of two major parts: one is its base structure, also called the magnetic scale, which is embedded with multiple grid MR electrodes, while another is an “MR reader” stage with magnets inside and moving on the rails of the base. As the stage is in motion, the magnetic interaction between the moving stage and the base causes the variation of the magneto-resistances of the grid electrodes. In this study, a front-end readout IC chip is successfully designed and realized to acquire temporally-varying resistances in electrical signals as the stage is in motions. The acquired signals are in fact sinusoids and co-sinusoids, which are further deciphered by the front-end readout circuit via newly-designed programmable gain amplifiers (PGAs and analog-to-digital converters (ADCs. The PGA is particularly designed to amplify the signals up to full dynamic ranges and up to 1 MHz. A 12-bit successive approximation register (SAR ADC for analog-to-digital conversion is designed with linearity performance of ±1 in the least significant bit (LSB over the input range of 0.5–2.5 V from peak to peak. The chip was fabricated by the Taiwan Semiconductor Manufacturing Company (TSMC 0.35-micron complementary metal oxide semiconductor (CMOS technology for verification with a chip size of 6.61 mm2, while the power consumption is 56 mW from a 5-V power supply. The measured integral non-linearity (INL is −0.79–0.95 LSB while the differential non-linearity (DNL is −0.68–0.72 LSB. The effective number of bits (ENOB of the designed ADC is validated as 10.86 for converting the input analog signal to digital counterparts. Experimental validation was conducted. A digital decoder is orchestrated to decipher the harmonic outputs from the ADC via interpolation to the position of the moving stage. It was found that the displacement

  8. Usage Count: A New Indicator to Detect Research Fronts

    Directory of Open Access Journals (Sweden)

    Guoqiang Liang

    2017-01-01

    Full Text Available Purpose: Research fronts build on recent work, but using times cited as a traditional indicator to detect research fronts will inevitably result in a certain time lag. This study attempts to explore the effects of usage count as a new indicator to detect research fronts in shortening the time lag of classic indicators in research fronts detection. Design/methodology/approach: An exploratory study was conducted where the new indicator “usage count” was compared to the traditional citation count, “times cited,” in detecting research fronts of the regenerative medicine domain. An initial topic search of the term “regenerative medicine” returned 10,553 records published between 2000 and 2015 in the Web of Science (WoS. We first ranked these records with usage count and times cited, respectively, and selected the top 2,000 records for each. We then performed a co-citation analysis in order to obtain the citing papers of the co-citation clusters as the research fronts. Finally, we compared the average publication year of the citing papers as well as the mean cited year of the co-citation clusters. Findings: The citing articles detected by usage count tend to be published more recently compared with times cited within the same research front. Moreover, research fronts detected by usage count tend to be within the last two years, which presents a higher immediacy and real-time feature compared to times cited. There is approximately a three-year time span among the mean cited years (known as “intellectual base” of all clusters generated by usage count and this figure is about four years in the network of times cited. In comparison to times cited, usage count is a dynamic and instant indicator. Research limitations: We are trying to find the cutting-edge research fronts, but those generated based on co-citations may refer to the hot research fronts. The usage count of older highly cited papers was not taken into consideration, because the

  9. Iu. Ushakov & A. Stukalov, Front voennykh prokurorov [The Military Procurators’ Front], Moskva, Viatka, 2000, 223 pages.

    Directory of Open Access Journals (Sweden)

    Vanessa Voisin

    2008-07-01

    Full Text Available Front voennykh prokurorov is a collection of essays written by two writers who are not known as specialists of military history, but obviously have access to archives, as proves the reprint, in the middle of the book, of several pages from the personal files of Afanas’ev, former Main Military Prosecutor of Soviet Armed Forces.The first part of the book is devoted to Nikolai Porfir’evich Afanas’ev’s memoirs, written, according to the editors, after his retirement in 1950. Afanas’ev, though les...

  10. Biomechanics of competitive front crawl swimming.

    Science.gov (United States)

    Toussaint, H M; Beek, P J

    1992-01-01

    Essential performance-determining factors in front crawl swimming can be analysed within a biomechanical framework, in reference to the physiological basis of performance. These factors include: active drag forces, effective propulsive forces, propelling efficiency and power output. The success of a swimmer is determined by the ability to generate propulsive force, while reducing the resistance to forward motion. Although for a given competitive stroke a range of optimal stroking styles may be expected across a sample of swimmers, a common element of technique related to a high performance level is the use of complex sculling motions of the hands to generate especially lift forces. By changing the orientation of the hand the propulsive force acting on the hand is aimed successfully in the direction of motion. Furthermore, the swimming velocity (v) is related to drag (A), power input (Pi, the rate of energy liberation via the aerobic/anaerobic metabolism), the gross efficiency (eg), propelling efficiency (ep), and power output (Po) according to: [formula; see text] Based on the research available at present it is concluded that: (a) drag in groups of elite swimmers homogeneous with respect to swimming technique is determined by anthropometric dimensions; (b) total mechanical power output (Po) is important since improvement in performance is related to increased Po. Furthermore, it shows dramatic changes with training and possibly reflects the size of the 'swimming engine'; (c) propelling efficiency seems to be important since it is much higher in elite swimmers (61%) than in triathletes (44%); and (d) distance per stroke gives a fairly good indication of propelling efficiency and may be used to evaluate individual progress in technical ability.

  11. Hindrances to bistable front propagation: application to Wolbachia invasion.

    Science.gov (United States)

    Nadin, Grégoire; Strugarek, Martin; Vauchelet, Nicolas

    2017-09-22

    We study the biological situation when an invading population propagates and replaces an existing population with different characteristics. For instance, this may occur in the presence of a vertically transmitted infection causing a cytoplasmic effect similar to the Allee effect (e.g. Wolbachia in Aedes mosquitoes): the invading dynamics we model is bistable. We aim at quantifying the propagules (what does it take for an invasion to start?) and the invasive power (how far can an invading front go, and what can stop it?). We rigorously show that a heterogeneous environment inducing a strong enough population gradient can stop an invading front, which will converge in this case to a stable front. We characterize the critical population jump, and also prove the existence of unstable fronts above the stable (blocking) fronts. Being above the maximal unstable front enables an invading front to clear the obstacle and propagate further. We are particularly interested in the case of artificial Wolbachia infection, used as a tool to fight arboviruses.

  12. Spin-1 particles with light-front approach

    Directory of Open Access Journals (Sweden)

    de Melo J.P.B.C.

    2014-06-01

    Full Text Available For the vector sector, i.e, mesons with spin-1, the electromagnetic form factors and anothers observables are calculated with the light-front approach. However, the light-front quantum field theory have some problems, for example, the rotational symmetry breaking. We solve that problem added the zero modes contribuition to the matrix elements of the electromagnetic current, besides the valence contribuition. We found that among the four independent matrix elements of the plus component in the light-front helicity basis only the 0 → 0 one carries zero mode contributions.

  13. Determination of cut front position in laser cutting

    Science.gov (United States)

    Pereira, M.; Thombansen, U.

    2016-07-01

    Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable.

  14. Adaptive RF front-ends for hand-held applications

    CERN Document Server

    van Bezooijen, Andre; van Roermund, Arthur

    2010-01-01

    The RF front-end - antenna combination is a vital part of a mobile phone because its performance is very relevant to the link quality between hand-set and cellular network base-stations. The RF front-end performance suffers from changes in operating environment, like hand-effects, that are often unpredictable. ""Adaptive RF Front-Ends for Hand-Held Applications"" presents an analysis on the impact of fluctuating environmental parameters. In order to overcome undesired behavior two different adaptive control methods are treated that make RF frond-ends more resilient: adaptive impedance control,

  15. Visible leadership: going back to the front line.

    Science.gov (United States)

    Davies, Nigel

    2013-07-01

    The report into care at Mid Staffordshire NHS Foundation Trust called for strong leadership in nursing and the government's response acknowledged the importance of senior managers gaining front line experience of the NHS. This article discusses the background to the need for visible leadership and the advantages and disadvantages of different approaches to engaging with the front line. Lessons from other industries are considered and a spectrum of engagement activities relevant to health care suggested. Senior leaders' visits to the front line have brought identified benefits for staff but there is little proof of patient benefits, so more research needs to be commissioned to generate evidence of effectiveness.

  16. A hybrid level set-front tracking finite element approach for fluid-structure interaction and two-phase flow applications

    Science.gov (United States)

    Basting, Steffen; Weismann, Martin

    2013-12-01

    We present a hybrid level set-front tracking approach suitable for fluid-structure interaction and two-phase flow applications. Our approach aims at extending geometrical flexibility of standard mesh moving/front tracking methods by introducing an additional implicit level set representation of the geometry under consideration. The computational mesh is automatically aligned to the implicitly described geometry by minimizing a nonlinear, constrained functional. Resulting triangulations approximate the geometry accurately while being optimal in a certain sense. Due to the mesh alignment, finite element spaces defined on these triangulations may be easily adjusted to account for special solution properties such as discontinuities across interfaces. In order to demonstrate the flexibility of the proposed approach, we apply it to a simplified one-way coupled fluid-structure interaction problem inspired by the flow induced by a moving cardiac valve. Furthermore we evaluate the approach by solving a two-phase flow benchmark problem.

  17. Toward a conceptual model relating chemical reaction fronts to water flow paths in hills

    Science.gov (United States)

    Brantley, Susan L.; Lebedeva, Marina I.; Balashov, Victor N.; Singha, Kamini; Sullivan, Pamela L.; Stinchcomb, Gary

    2017-01-01

    Both vertical and lateral flows of rock and water occur within eroding hills. Specifically, when considered over geological timeframes, rock advects vertically upward under hilltops in landscapes experiencing uplift and erosion. Once rock particles reach the land surface, they move laterally and down the hillslope because of erosion. At much shorter timescales, meteoric water moves vertically downward until it reaches the regional water table and then moves laterally as groundwater flow. Water can also flow laterally in the shallow subsurface as interflow in zones of permeability contrast. Interflow can be perched or can occur during periods of a high regional water table. The depths of these deep and shallow water tables in hills fluctuate over time. The fluctuations drive biogeochemical reactions between water, CO2, O2, and minerals and these in turn drive fracturing. The depth intervals of water table fluctuation for interflow and groundwater flow are thus reaction fronts characterized by changes in composition, fracture density, porosity, and permeability. The shallow and deep reaction zones can separate over meters in felsic rocks. The zones act like valves that reorient downward unsaturated water flow into lateral saturated flow. The valves also reorient the upward advection of rock into lateral flow through solubilization. In particular, groundwater removes highly soluble, and interflow removes moderately soluble minerals. As rock and water moves through the system, hills may evolve toward a condition where the weathering advance rate, W, approaches the erosion rate, E. If W = E, the slopes of the deep and shallow reaction zones and the hillsides must allow removal of the most soluble, moderately soluble, and least soluble minerals respectively. A permeability architecture thus emerges to partition each evolving hill into dissolved and particulate material fluxes as it approaches steady state.

  18. Effects of freezing on soil temperature, freezing front propagation and moisture redistribution in peat: laboratory investigations

    Directory of Open Access Journals (Sweden)

    R. M. Nagare

    2012-02-01

    Full Text Available There are not many studies that report water movement in freezing peat. Soil column studies under controlled laboratory settings can help isolate and understand the effects of different factors controlling freezing of the active layer in organic covered permafrost terrain. In this study, four peat Mesocosms were subjected to temperature gradients by bringing the Mesocosm tops in contact with sub-zero air temperature while maintaining a continuously frozen layer at the bottom (proxy permafrost. Soil water movement towards the freezing front (from warmer to colder regions was inferred from soil freezing curves, liquid water content time series and from the total water content of frozen core samples collected at the end of freezing cycle. A substantial amount of water, enough to raise the upper surface of frozen saturated soil within 15 cm of the soil surface at the end of freezing period appeared to have moved upwards during freezing. Diffusion under moisture gradients and effects of temperature on soil matric potential, at least in the initial period, appear to drive such movement as seen from analysis of freezing curves. Freezing front (separation front between soil zones containing and free of ice propagation is controlled by latent heat for a long time during freezing. A simple conceptual model describing freezing of an organic active layer initially resembling a variable moisture landscape is proposed based upon the results of this study. The results of this study will help in understanding, and ultimately forecasting, the hydrologic response of wetland-dominated terrain underlain by discontinuous permafrost.

  19. Novel Simulated moving bed technologies

    Energy Technology Data Exchange (ETDEWEB)

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  20. Interacting wave fronts and rarefaction waves in a second order model of nonlinear thermoviscous fluids : Interacting fronts and rarefaction waves

    DEFF Research Database (Denmark)

    Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

    2011-01-01

    the Hamiltonian structure, in contrast to the Kuznetsov equation, a model often used in nonlinear acoustics. An exact traveling wave front solution is derived from a generalized traveling wave assumption for the velocity potential. Numerical studies of the evolution of a number of arbitrary initial conditions...... as well as head-on colliding and confluent wave fronts exhibit several nonlinear interaction phenomena. These include wave fronts of changed velocity and amplitude along with the emergence of rarefaction waves. An analysis using the continuity of the solutions as well as the boundary conditions...

  1. Your employees: the front line in cyber security

    OpenAIRE

    Ashenden, D

    2016-01-01

    First published in The Chemical Engineer and reproduced by Crest - Centre for Research and Evidence on Security Threats, 26/01/2016 (https://crestresearch.ac.uk/comment/employees-front-line-cyber-security/)

  2. Relvakogujad sõjaajalooklubist Front Line vahistati / Kadri Ratt

    Index Scriptorium Estoniae

    Ratt, Kadri

    2009-01-01

    Kaitsepolitsei võttis vahi alla 9 meest, keda kahtlustatakse suures koguses lõhkeainete, lõhkekehade ja tulirelvade ebaseaduslikus käitlemises. 6 meest neist kuuluvad sõjaajalooklubisse Front Line

  3. Antarctic Ice-Shelf Front Dynamics from ICESat

    Science.gov (United States)

    Robbins, John W.; Zwally, H. Jay; Saba, Jack L.; Yi, Donghui

    2012-01-01

    Time variable elevation profiles from ICESat Laser Altimetry over the period 2003-2009 provide a means to quantitatively detect and track topographic features on polar ice surfaces. The results of this study provide a measure of the horizontal motion of ice-shelf fronts. We examine the time histories of elevation profiles crossing the ice fronts of the Ross, Ronne, Filchner, Riiser-Larson and Fimbul shelves. This provides a basis for estimating dynamics in two dimensions, i.e. in elevation and horizontally in the along-track direction. Ice front velocities, corrected for ground-track intersection angle, range from nearly static to 1.1 km/yr. In many examples, a decrease in elevation up to 1 m/yr near the shelf frontis also detectable. Examples of tabular calving along shelf fronts are seen in some elevation profiles and are confirmed by corresponding MODIS imagery.

  4. Management plan for Midcontinent greater white-fronted geese

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this plan is to provide guidelines for management decisions affecting the Midcontinent Population of Greater White-fronted Geese (Anser albifrons...

  5. FACILITATING RADICAL FRONT-END INNOVATION THROUGH TARGETED HR PRACTICES

    DEFF Research Database (Denmark)

    Aagaard, Annabeth

    2017-01-01

    This study examines how radical front end innovation can be actively facilitated through selected and targeted HR practices and bundles of HR practices. The empirical field is an explorative case study of front end innovation and HR practices in the pharmaceutical industry, with an in-depth case...... study of the Danish pharmaceutical company, H. Lundbeck A/S, and explorative studies of seven European and American pharmaceutical and biotech companies. The study aims to show how companies can apply HR practices in ways that actively supports the development of radical front end innovation. The value...... added and the contribution of this article to the existing FEI and HR literature therefore lies in the exploration and mapping of how radical front end innovation is and can be facilitated through targeted HR practices; and in identifying the unique opportunities and challenges of innovation...

  6. Quarkonium as a relativistic bound state on the light front

    Science.gov (United States)

    Li, Yang; Maris, Pieter; Vary, James P.

    2017-07-01

    We study charmonium and bottomonium as relativistic bound states in a light-front quantized Hamiltonian formalism. The effective Hamiltonian is based on light-front holography. We use a recently proposed longitudinal confinement to complete the soft-wall holographic potential for the heavy flavors. The spin structure is generated from the one-gluon exchange interaction with a running coupling. The adoption of asymptotic freedom improves the spectroscopy compared with previous light-front results. Within this model, we compute the mass spectroscopy, decay constants and the r.m.s. radii. We also present a detailed study of the obtained light-front wave functions and use the wave functions to compute the light-cone distributions, specifically the distribution amplitudes and parton distribution functions. Overall, our model provides a reasonable description of the heavy quarkonia.

  7. Nucleon parton distributions in a light-front quark model

    National Research Council Canada - National Science Library

    Gutsche, Thomas; Lyubovitskij, Valery E; Schmidt, Ivan

    2017-01-01

    Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions...

  8. Theses "Discussion" Sections: A Structural Move Analysis

    Science.gov (United States)

    Nodoushan, Mohammad Ali Salmani; Khakbaz, Nafiseh

    2011-01-01

    The current study aimed at finding the probable differences between the move structure of Iranian MA graduates' thesis discussion subgenres and those of their non-Iranian counterparts, on the one hand, and those of journal paper authors, on the other. It also aimed at identifying the moves that are considered obligatory, conventional, or optional…

  9. Improvisation: Another Way to Move and Dance

    Science.gov (United States)

    Morgan, Rachel

    2004-01-01

    Using improvisation in movement and dance classes is an ideal way to help students relate to how their bodies move. Students can learn confidence from the way they move by experimenting with unconventional and different methods. Improvisation, as such, is responding spontaneously to stimuli (music) in order to create a composition that allows for…

  10. Moving core beam energy absorber and converter

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  11. Multivariate Exponential Autoregressive and Autoregressive Moving ...

    African Journals Online (AJOL)

    Autoregressive (AR) and autoregressive moving average (ARMA) processes with multivariate exponential (ME) distribution are presented and discussed. The theory of positive dependence is used to show that in many cases, multivariate exponential autoregressive (MEAR) and multivariate autoregressive moving average ...

  12. Student-Centered Coaching: The Moves

    Science.gov (United States)

    Sweeney, Diane; Harris, Leanna S.

    2017-01-01

    Student-centered coaching is a highly-effective, evidence-based coaching model that shifts the focus from "fixing" teachers to collaborating with them to design instruction that targets student outcomes. But what does this look like in practice? "Student-Centered Coaching: The Moves" shows you the day-to-day coaching moves that…

  13. Natural convection flow between moving boundaries | Chepkwony ...

    African Journals Online (AJOL)

    The laminar steady natural convection flow of viscous, incompressible fluid between two moving vertical plates is considered. It is assumed that the plates are moving in opposite direction with equal velocity. The two-point boundary value problem governing the flow is characterized by a non-dimensional parameter K. It is ...

  14. Gas dynamics during the sphere moving in the stationary gaseous environment

    Directory of Open Access Journals (Sweden)

    Leonid I. Gretchihin

    2014-06-01

    Full Text Available This paper developed a mathematical model of the gas dynamic fluid flow around the sphere. There are three areas of different mechanisms of the interaction of moving spheres and stationary gaseous environment. It has been proved that  shear flow plays a decisiverole at sphere low velocities, while at sphere velocities close to the speed of sound the critical role is exerted by the impact interaction of the sphere with the center in the front hemisphere. The shear flow behind the sphere makes a cone with stationary gaseous environment. The principle which defines the size of the cone has been established.

  15. Southern Ocean fronts from the Greenwich meridian to Tasmania

    Science.gov (United States)

    Belkin, Igor M.; Gordon, Arnold L.

    1996-02-01

    All available meridional sections have been analyzed to investigate the evolution of main fronts between 0° and 150°E. The central South Atlantic is featured by the Subtropical Frontal Zone (STFZ), bordered by the North and South Subtropical Fronts (NSTF and SSTF, respectively), and by the Polar Frontal Zone (PFZ), bordered by the Subantarctic and Polar Fronts (SAF and PF, respectively). This structure becomes more complex in the African sector as the Agulhas Retroflection and the bottom topography force a more convoluted pattern. The Retroflection and associated Agulhas Front (AF) press the SSTF from 38° to 42°-43°S. Strong interactions of the AF, SSTF, and SAF with topography shift the fronts but do not obliterate them. The AF can be traced reliably up to 52°E, sometimes up to 75°E. The SAF is deflected from 45° to 43°S by the Mid-Ocean Ridge and converges with the SSTF north of the Prince Edward Islands to form a combined SSTF/SAF. This front intensifies east of 50°-52°E as a result of the confluence with the AF, and between 52° and 65°E a triple AF/SSTF/SAF ("the Crozet Front") is observed. The PF continues along 49° and 50°S between the Crozet Plateau and the Ob-Lena (Conrad) Rise, passing north of Kerguelen, nearly joining the triple Crozet Front. Downstream of the Kerguelen-Amsterdam Passage, the canonical structure is being restored (SSTF, SAF, PF); however, the front parameters in the Australian sector are different from the African sector, largely because of strong air-sea interaction and cross-frontal exchanges in the Crozet-Kerguelen region. The SSTF, squeezed between the AF and SAF, loses characteristics to both. The SSTF/SAF interaction results in the Australian SAF being warmer and saltier downstream, while the SSTF becomes shallower and weaker. The Australian STF derives its characteristics mostly from the AF, thus bringing the modified Agulhas waters to the Pacific Ocean. The newly defined North Subtropical Front (NSTF) was

  16. 25 CFR 700.157 - Actual reasonable moving and related expenses-nonresidential moves.

    Science.gov (United States)

    2010-04-01

    ... services, including architect's, attorney's and engineer's fees, and consultant's charges, necessary for (i) planning the move of the personal property, (ii) moving the personal property, or (iii) installing the...

  17. Tsunami generation by ocean floor rupture front propagation: Hamiltonian description

    Directory of Open Access Journals (Sweden)

    V. I. Pavlov

    2009-02-01

    Full Text Available The Hamiltonian method is applied to the problem of tsunami generation caused by a propagating rupture front and deformation of the ocean floor. The method establishes an alternative framework for analyzing the tsunami generation process and produces analytical expressions for the power and directivity of tsunami radiation (in the far-field for two illustrative cases, with constant and gradually varying speeds of rupture front propagation.

  18. Traveling wave front solutions in lateral-excitatory neuronal networks

    Directory of Open Access Journals (Sweden)

    Sittipong Ruktamatakul

    2008-05-01

    Full Text Available In this paper, we discuss the shape of traveling wave front solutions to a neuronal model with the connection function to be of lateral excitation type. This means that close connecting cells have an inhibitory influence, while cells that aremore distant have an excitatory influence. We give results on the shape of the wave fronts solutions, which exhibit different shapes depend ing on the size of a threshold parameter.

  19. Flow structure in front of the broad-crested weir

    Directory of Open Access Journals (Sweden)

    Zachoval Zbyněk

    2015-01-01

    Full Text Available The paper deals with research focused on description of flow structure in front of broad-crested weir. Based on experimental measurement, the flow structure in front of the weir (the recirculation zone of flow and tornado vortices and flow structure on the weir crest has been described. The determined flow character has been simulated using numerical model and based on comparing results the suitable model of turbulence has been recommended.

  20. Indico front-end: From spaghetti to lasagna

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    We will present how we transitioned from legacy spaghetti UI code to a more coherent, easier to understand and maintain ecosystem of front-end technologies and facilities with a strong emphasis in reusable components. In particular, we will share with you: 1) how we use Sass to maintain our home-baked CSS, 2) how we survive in 2017 without front-end Javascript frameworks, and 3) how we use template macros and WTForms for generating consistent HTML transparently.

  1. Light-Front Holography and AdS/QCD Correspondence

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; de Teramond, Guy F.

    2008-04-23

    Light-Front Holography is a remarkable consequence of the correspondence between string theory in AdS space and conformal field theories in physical-space time. It allows string modes {Phi}(z) in the AdS fifth dimension to be precisely mapped to the light-front wavefunctions of hadrons in terms of a specific light-front impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron. This mapping was originally obtained by matching the exact expression for electromagnetic current matrix elements in AdS space with the corresponding exact expression for the current matrix element using light-front theory in physical space-time. More recently we have shown that one obtains the identical holographic mapping using matrix elements of the energy-momentum tensor, thus providing an important consistency test and verification of holographic mapping from AdS to physical observables defined on the light-front. The resulting light-front Schrodinger equations predicted from AdS/QCD give a good representation of the observed meson and baryon spectra and give excellent phenomenological predictions for amplitudes such as electromagnetic form factors and decay constants.

  2. Observed Low Frequency Variability of the Brazil Current Front

    Science.gov (United States)

    Goni, G. J.; Bringas Gutierrez, F.; Di Nezio, P. N.

    2012-12-01

    The Brazil Current is a weak western boundary current, the southwest component of the South Atlantic subtropical gyre, which is the main conduit of upper ocean waters in the region. We report her the observed low frequency variability of the Brazil Current front using satellite-derived sea height anomaly and sea surface temperature observations during the 1993-2008 period. The variability of the front is studied in terms of the separation of the Brazil Current front from the continental shelf break. During the study period, estimates of this parameter indicate a shift to the south of approximately 1.5 degrees. Statistically significant changes are not observed in the geostrophic transport of the Brazil and Malvinas currents suggesting that the low-frequency changes of the Brazil Current front are governed by different mechanisms than the seasonal variability of these surface currents. Surface drifter trajectories as well as simulations using synthetic drifters are consistent with the observed shift to the south of the Brazil Current front. Trends of eddy kinetic energy, sea height anomaly, sea surface temperature and wind stress curl are also in agreement with the variability reported here. Wavelet transform analysis revealed an interesting change in the periodicity of the separation of the Brazil Current front from the continental shelf break from annual to bi-annual during 2003. Longer records together with comprehensive numerical experiments will ultimately be needed to determine the origin of these changes.

  3. 29 CFR 779.249 - Goods which move or have moved across State lines.

    Science.gov (United States)

    2010-07-01

    ... sells the goods. Thus, if goods have moved across State lines at some stage in the flow of trade before... 29 Labor 3 2010-07-01 2010-07-01 false Goods which move or have moved across State lines. 779.249... STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply; Enterprise...

  4. Moving Matters: The Causal Effect of Moving Schools on Student Performance. Working Paper #01-15

    Science.gov (United States)

    Schwartz, Amy Ellen; Stiefel, Leanna; Cordes, Sarah A.

    2015-01-01

    The majority of existing research on mobility indicates that students do worse in the year of a school move. This research, however, has been unsuccessful in isolating the causal effects of mobility and often fails to distinguish the heterogeneous impacts of moves, conflating structural moves (mandated by a school's terminal grade) and…

  5. Digital front-end module (DFEM) series; Digital front end module (DFEM) series

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The digital front-end module (DFEM) is a module in which the processes ranging from the reception of digitally modulated radiofrequencies to the output of digital IF (Intermediate Frequency) signals or data streams are integrated. Beginning with a module for the MCNS (Multimedia Cable Network System) cable modem which was the first module in this business field approved by the Cable Labs, U.S., Toshiba has developed a series of DFEMs for various digital media for satellites, ground waves, and CATV (Cable Television) systems. The series is characterized by (1) the serialization of DFEMs compatible with various digital modulation techniques such as 8 PSK (Phase Shift Keying), OFDM (Orthogonal Frequency Division Multiplexing), and 256 QAM (Quadrature Amplitude Modulation), (2) easy connection with digital circuits thanks to the high shielding effect, and (3) the achievement of smaller size, higher performance, and lower power consumption. (translated by NEDO)

  6. Combustion waves and fronts in flows flames, shocks, detonations, ablation fronts and explosion of stars

    CERN Document Server

    Clavin, Paul

    2016-01-01

    Combustion is a fascinating phenomenon coupling complex chemistry to transport mechanisms and nonlinear fluid dynamics. This book provides an up-to-date and comprehensive presentation of the nonlinear dynamics of combustion waves and other non-equilibrium energetic systems. The major advances in this field have resulted from analytical studies of simplified models performed in close relation with carefully controlled laboratory experiments. The key to understanding the complex phenomena is a systematic reduction of the complexity of the basic equations. Focusing on this fundamental approach, the book is split into three parts. Part I provides physical insights for physics-oriented readers, Part II presents detailed technical analysis using perturbation methods for theoreticians, and Part III recalls the necessary background knowledge in physics, chemistry and fluid dynamics. This structure makes the content accessible to newcomers to the physics of unstable fronts in flows, whilst also offering advanced mater...

  7. A fast and accurate numerical method for solving simulated moving bed (SMB) chromatographic separation problems

    DEFF Research Database (Denmark)

    Lim, Young-il; Jørgensen, Sten Bay

    2003-01-01

    numerical solutions are obtained. Stable solutions are guaranteed if the Courant-Friedrichs-Lewy (CFL) condition is satisfied. The boundary condition and recycle flow treatments are much simpler than for the time integrator in the framework of the method of lines. Applying the CE/SE method for SMB......Solving simulated moving bed (SMB) chromatography models requires fast and accurate numerical techniques, since their system size computed is large due to multi-columns and multi-components, in addition the axial solution profiles contain steep moving fronts. The space-time conservation element....../solution element (CE/SE) method addressed in this study enforces both local and global flux conservation in space and time, and uses a simple stencil structure (two points at the previous time level and one point at the present time level) on staggered space-time grids. Thus, accurate and computationally efficient...

  8. A beam-splitter-type 3-D endoscope for front view and front-diagonal view images.

    Science.gov (United States)

    Kamiuchi, Hiroki; Masamune, Ken; Kuwana, Kenta; Dohi, Takeyoshi; Kim, Keri; Yamashita, Hiromasa; Chiba, Toshio

    2013-01-01

    In endoscopic surgery, surgeons must manipulate an endoscope inside the body cavity to observe a large field-of-view while estimating the distance between surgical instruments and the affected area by reference to the size or motion of the surgical instruments in 2-D endoscopic images on a monitor. Therefore, there is a risk of the endoscope or surgical instruments physically damaging body tissues. To overcome this problem, we developed a Ø7- mm 3-D endoscope that can switch between providing front and front-diagonal view 3-D images by simply rotating its sleeves. This 3-D endoscope consists of a conventional 3-D endoscope and an outer and inner sleeve with a beam splitter and polarization plates. The beam splitter was used for visualizing both the front and front-diagonal view and was set at 25° to the outer sleeve's distal end in order to eliminate a blind spot common to both views. Polarization plates were used to avoid overlap of the two views. We measured signal-to-noise ratio (SNR), sharpness, chromatic aberration (CA), and viewing angle of this 3-D endoscope and evaluated its feasibility in vivo. Compared to the conventional 3-D endoscope, SNR and sharpness of this 3-D endoscope decreased by 20 and 7 %, respectively. No significant difference was found in CA. The viewing angle for both the front and front-diagonal views was about 50°. In the in vivo experiment, this 3-D endoscope can provide clear 3-D images of both views by simply rotating its inner sleeve. The developed 3-D endoscope can provide the front and front-diagonal view by simply rotating the inner sleeve, therefore the risk of damage to fragile body tissues can be significantly decreased.

  9. Ensemble-based analysis of Front Range severe convection on 6-7 June 2012: Forecast uncertainty and communication of weather information to Front Range decision-makers

    Science.gov (United States)

    Vincente, Vanessa

    The variation of topography in Colorado not only adds to the beauty of its landscape, but also tests our ability to predict warm season severe convection. Deficient radar coverage and limited observations make quantitative precipitation forecasting quite a challenge. Past studies have suggested that greater forecast skill of mesoscale convection initiation and precipitation characteristics are achievable considering an ensemble with explicitly predicted convection compared to one that has parameterized convection. The range of uncertainty and probabilities in these forecasts can help forecasters in their precipitation predictions and communication of weather information to emergency managers (EMs). EMs serve an integral role in informing and protecting communities in anticipation of hazardous weather. An example of such an event occurred on the evening of 6 June 2012, where areas to the lee of the Rocky Mountain Front Range were impacted by flash-flood-producing severe convection that included heavy rain and copious amounts of hail. Despite the discrepancy in the timing, location and evolution of convection, the convection-allowing ensemble forecasts generally outperformed those of the convection-parameterized ensemble in representing the mesoscale processes responsible for the 6-7 June severe convective event. Key features sufficiently reproduced by several of the convection-allowing ensemble members resembled the observations: 1) general location of a convergence boundary east of Denver, 2) convective initiation along the boundary, 3) general location of a weak cold front near the Wyoming/Nebraska border, and 4) cold pools and moist upslope characteristics that contributed to the backbuilding of convection. Members from the convection-parameterized ensemble that failed to reproduce these results displaced the convergence boundary, produced a cold front that moved southeast too quickly, and used the cold front for convective initiation. The convection

  10. Rearrangement moves on rooted phylogenetic networks.

    Directory of Open Access Journals (Sweden)

    Philippe Gambette

    2017-08-01

    Full Text Available Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide

  11. Rearrangement moves on rooted phylogenetic networks.

    Science.gov (United States)

    Gambette, Philippe; van Iersel, Leo; Jones, Mark; Lafond, Manuel; Pardi, Fabio; Scornavacca, Celine

    2017-08-01

    Phylogenetic tree reconstruction is usually done by local search heuristics that explore the space of the possible tree topologies via simple rearrangements of their structure. Tree rearrangement heuristics have been used in combination with practically all optimization criteria in use, from maximum likelihood and parsimony to distance-based principles, and in a Bayesian context. Their basic components are rearrangement moves that specify all possible ways of generating alternative phylogenies from a given one, and whose fundamental property is to be able to transform, by repeated application, any phylogeny into any other phylogeny. Despite their long tradition in tree-based phylogenetics, very little research has gone into studying similar rearrangement operations for phylogenetic network-that is, phylogenies explicitly representing scenarios that include reticulate events such as hybridization, horizontal gene transfer, population admixture, and recombination. To fill this gap, we propose "horizontal" moves that ensure that every network of a certain complexity can be reached from any other network of the same complexity, and "vertical" moves that ensure reachability between networks of different complexities. When applied to phylogenetic trees, our horizontal moves-named rNNI and rSPR-reduce to the best-known moves on rooted phylogenetic trees, nearest-neighbor interchange and rooted subtree pruning and regrafting. Besides a number of reachability results-separating the contributions of horizontal and vertical moves-we prove that rNNI moves are local versions of rSPR moves, and provide bounds on the sizes of the rNNI neighborhoods. The paper focuses on the most biologically meaningful versions of phylogenetic networks, where edges are oriented and reticulation events clearly identified. Moreover, our rearrangement moves are robust to the fact that networks with higher complexity usually allow a better fit with the data. Our goal is to provide a solid basis for

  12. Drilling technology advances on four fronts

    Energy Technology Data Exchange (ETDEWEB)

    Budd, G.

    2002-01-01

    wall that is wrapped around the derrick. Above that is a 15-ft wall as the racking board. These walls, plus a heated doghouse the size of a telephone booth, help prevent the derrick hand from freezing. The heated air within the enclosed complex is constantly moving, hence any gas build-up is mitigated. 3 photos.

  13. Performance Simulations of Moving Target Search Algorithms

    Directory of Open Access Journals (Sweden)

    Peter K. K. Loh

    2009-01-01

    Full Text Available The design of appropriate moving target search (MTS algorithms for computer-generated bots poses serious challenges as they have to satisfy stringent requirements that include computation and execution efficiency. In this paper, we investigate the performance and behaviour of existing moving target search algorithms when applied to search-and-capture gaming scenarios. As part of the investigation, we also introduce a novel algorithm known as abstraction MTS. We conduct performance simulations with a game bot and moving target within randomly generated mazes of increasing sizes and reveal that abstraction MTS exhibits competitive performance even with large problem spaces.

  14. Interaction of a neutral cloud moving through a magnetized plasma

    Science.gov (United States)

    Goertz, C. K.; Lu, G.

    1990-01-01

    Current collection by outgassing probes in motion relative to a magnetized plasma may be significantly affected by plasma processes that cause electron heating and cross field transport. Simulations of a neutral gas cloud moving across a static magnetic field are discussed. The authors treat a low-Beta plasma and use a 2-1/2 D electrostatic code linked with the authors' Plasma and Neutral Interaction Code (PANIC). This study emphasizes the understanding of the interface between the neutral gas cloud and the surrounding plasma where electrons are heated and can diffuse across field lines. When ionization or charge exchange collisions occur a sheath-like structure is formed at the surface of the neutral gas. In that region the crossfield component of the electric field causes the electron to E times B drift with a velocity of the order of the neutral gas velocity times the square root of the ion to electron mass ratio. In addition a diamagnetic drift of the electron occurs due to the number density and temperature inhomogeneity in the front. These drift currents excite the lower-hybrid waves with the wave k-vectors almost perpendicular to the neutral flow and magnetic field again resulting in electron heating. The thermal electron current is significantly enhanced due to this heating.

  15. Wind bubbles within H ii regions around slowly moving stars

    Science.gov (United States)

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

    2015-01-01

    Interstellar bubbles around O stars are driven by a combination of the star's wind and ionizing radiation output. The wind contribution is uncertain because the boundary between the wind and interstellar medium is difficult to observe. Mid-infrared observations (e.g., of the H ii region RCW 120) show arcs of dust emission around O stars, contained well within the H ii region bubble. These arcs could indicate the edge of an asymmetric stellar wind bubble, distorted by density gradients and/or stellar motion. We present two-dimensional, radiation-hydrodynamics simulations investigating the evolution of wind bubbles and H ii regions around massive stars moving through a dense (nH = 3000 cm-3), uniform medium with velocities ranging from 4 to 16 km s-1. The H ii region morphology is strongly affected by stellar motion, as expected, but the wind bubble is also very aspherical from birth, even for the lowest space velocity considered. Wind bubbles do not fill their H ii regions (we find filling factors of 10-20 per cent), at least for a main sequence star with mass M⋆ ~ 30 M⊙. Furthermore, even for supersonic velocities the wind bow shock does not significantly trap the ionization front. X-ray emission from the wind bubble is soft, faint, and comes mainly from the turbulent mixing layer between the wind bubble and the H ii region. The wind bubble radiates Movies are available in electronic form at http://www.aanda.org

  16. ALMA North American Integration Center Front-End Test System

    Science.gov (United States)

    Ediss, Geoffrey A.; Crabtree, Joshua; Crady, Kirk; Gaines, Erik; McLeod, Morgan; Morris, Greg; Williams, Rick; Perfetto, Antonio; Webber, John

    2010-10-01

    The Atacama Large Millimeter/submillimeter (ALMA) Array Front End (FE) system is the first element in a complex chain of signal receiving, conversion, processing and recording. 70 Front Ends will be required for the project. The Front End is designed to receive signals in ten different frequency bands. In the initial phase of operations, the antennas will be fully equipped with six bands. These are Band 3 (84-116 GHz), Band 4 (125-163 GHz), Band 6 (211-275 GHz), Band 7 (275-373 GHz), Band 8 (385-500 GHz) and Band 9 (602-720 GHz). It is planned to equip the antennas with the missing bands at a later stage of ALMA operations, with a few Band 5 (163-211 GHz) and Band 10 (787-950 GHz) receivers in use before the end of the construction project. The ALMA Front End is far superior to any existing receiver systems; spin-offs of the ALMA prototypes are leading to improved sensitivities in existing millimeter and submillimeter observatories. The Front End units are comprised of numerous elements, produced at different locations in Europe, North America and East Asia and are integrated at several Front End integration centers (FEIC) to insure timely delivery of all the units to Chile. The North American FEIC (NA FEIC) is at the National Radio Astronomy Observatory facility in Charlottesville, Virginia, USA. This paper describes the design and performance of the test set used at the NA FEIC to check the performance of the Front Ends, following integration and prior to shipment to Chile.

  17. Orthodontic treatment for deep bite and retroclined upper front teeth in children.

    Science.gov (United States)

    Millett, Declan T; Cunningham, Susan J; O'Brien, Kevin D; Benson, Philip E; de Oliveira, Cesar M

    2017-10-02

    A Class II division 2 malocclusion is characterised by upper front teeth that are retroclined (tilted toward the roof of the mouth) and an increased overbite (deep overbite), which can cause oral problems and may affect appearance.This problem can be corrected by the use of special dental braces (functional appliances) that move the upper front teeth forward and change the growth of the upper or lower jaws, or both. Most types of functional appliances braces are removeable and this treatment approach does not usually require extraction of any permanent teeth. Additional treatment with fixed braces may be necessary to ensure the best result.An alternative approach is to provide space for the correction of the front teeth by moving the molar teeth backwards. This is done by applying a force to the teeth from the back of the head using a head brace (headgear) and transmitting this force to part of a fixed or removable dental brace that is attached to the back teeth. The treatment may be carried out with or without extraction of permanent teeth.If headgear use is not feasible, the back teeth may be held in place by bands connected to a fixed bar placed across the roof of the mouth or in contact with the front of the roof of the mouth. This treatment usually requires two permanent teeth to be taken out (one on each side). To establish whether orthodontic treatment that does not involve extraction of permanent teeth produces a result that is any different from no orthodontic treatment or orthodontic treatment involving extraction of permanent teeth, in children with a Class II division 2 malocclusion. Cochrane Oral Health's Information Specialist searched the following electronic databases: Cochrane Oral Health's Trials Register (to 10 January 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 11), MEDLINE Ovid (1946 to 10 January 2017), and Embase Ovid (1980 to 10 January 2017). To identify any unpublished or ongoing

  18. FDTD Seismic Simulation of Moving Tracked Vehicle

    National Research Council Canada - National Science Library

    Ketcham, Stephen

    2000-01-01

    This paper describes the utility of a large finite-difference time domain (FDTD) simulation of seismic wave propagation from a spatially and time varying source that generically represents a moving tracked vehicle...

  19. Moving Women Up the District Ladder

    National Research Council Canada - National Science Library

    Merri Rosenberg

    2017-01-01

    ..., was clearly moving on a fast track. [...]when her husband, who works in educational technology in another Ohio district, spotted a promotional notice on the AASA website about the association's upcoming Women's Leadership Consortium...

  20. Being Moved: Linguistic Representation and Conceptual Structure

    Directory of Open Access Journals (Sweden)

    Milena eKuehnast

    2014-11-01

    Full Text Available This study explored the organisation of the semantic field and the conceptual structure of moving experiences by investigating German-language expressions referring to the emotional state of being moved. We used present and past participles of eight psychological verbs as primes in a free word-association task, as these grammatical forms place their conceptual focus on the eliciting situation and on the felt emotional state, respectively. By applying a taxonomy of basic knowledge types and computing the Cognitive Salience Index, we identified joy and sadness as key emotional ingredients of being moved, and significant life events and art experiences as main elicitors of this emotional state. Metric multidimensional scaling analyses of the semantic field revealed that the core terms designate a cluster of emotional states characterised by low degrees of arousal and slightly positive valence, the latter due to a nearly balanced representation of positive and negative elements in the conceptual structure of being moved.

  1. MOVES2010a regional level sensitivity analysis

    Science.gov (United States)

    2012-12-10

    This document discusses the sensitivity of various input parameter effects on emission rates using the US Environmental Protection Agencys (EPAs) MOVES2010a model at the regional level. Pollutants included in the study are carbon monoxide (CO),...

  2. Moving objects management models, techniques and applications

    CERN Document Server

    Meng, Xiaofeng; Xu, Jiajie

    2014-01-01

    This book describes the topics of moving objects modeling and location tracking, indexing and querying, clustering, location uncertainty, traffic aware navigation and privacy issues as well as the application to intelligent transportation systems.

  3. Moving the Force: Desert Storm and Beyond

    Science.gov (United States)

    1994-12-01

    Desert Shield~ Desert Storm, we could have met our airlift deployment requirements 20 to 35 percent faster. ~° Similar analyses of the Somalian Restore...DATE DEC 1994 2. REPORT TYPE 3. DATES COVERED - 4. TITLE AND SUBTITLE Moving The Force: Desert Storm and Beyond 5a. CONTRACT NUMBER 5b...MOVING THE FORCE: Desert Storm and Beyond SCOTT W. CONRAD McNair Paper 32 December 1994 INSTITUTE FOR NATIONAL STRATEGIC STUDIES NATIONAL DEFENSE

  4. Moving Wallpaper-Digital Interactive Projections.

    OpenAIRE

    Richardson, Andrew

    2009-01-01

    Moving Wallpaper is an computational generative and reactive piece of work which comes from a desire to apply the ethos and design sensibilities of the Arts and Crafts movement within the context of contemporary design. Inspired by the elegant patterns, forms and structure of the Willow and Jasmine wallpaper designs of William Morris, the Moving Wallpaper project seeks to create digital ‘wallpaper’ which introduces the elegance, beauty and humanity of Arts and Crafts design into digital progr...

  5. Strength Enhancement of Car Front Bumper for Slow Speed Impact by FEA Method as per IIHS Regulation

    Science.gov (United States)

    Sonawane, Chandrakant Rameshchandra; Shelar, Ajit Lavaji

    2017-05-01

    Low speed collisions happen significantly due to on road slow moving heavy traffic as well as during parking of vehicles. The bumpers are provided in front and back side of a vehicle has two main purposes: first is to absorb the energy generated during these kinds of slow speed impacts and secondly to protect the expensive parts like main engine parts, radiators and connected engine cooling mechanism, headlights, taillights, etc, by slowing down the vehicles. The problem often in various cars bumper is that they doesn't line-up vertically during low speed impact and leads to damage of various parts which are costly to repair. Many a times bumper design does not have sufficient capacity to absorb the energy generated during these impact. Guideline by International Institute Highway Safety (IIHS) regulation provides useful insight for such low speed impact study. In this paper, slow speed impact test were conducted as per IIHS regulation in three positions namely central impact, left hand corner impact and right hand corner impact. Parameters including bumper material, shape, thickness and impact condition are analyzed using fine element analysis (FEA) to enhance crashworthiness design in low speed impact. Then the vehicle front structure has been modified suitably. It has been observed that lining up the front metal bumper with suitable stiffness provides the best result which ultimately reduces the damage to the vehicle parts.

  6. Acute Effects of Eccentric Overload on Concentric Front Squat Performance.

    Science.gov (United States)

    Munger, Cameron N; Archer, David C; Leyva, Whitney D; Wong, Megan A; Coburn, Jared W; Costa, Pablo B; Brown, Lee E

    2017-05-01

    Munger, CN, Archer, DC, Leyva, WD, Wong, MA, Coburn, JW, Costa, PB, and Brown, LE. Acute effects of eccentric overload on concentric front squat performance. J Strength Cond Res 31(5): 1192-1197, 2017-Eccentric overload is used to enhance performance. The purpose of this study was to investigate the acute effects of eccentric overload on concentric front squat performance. Twenty resistance-trained men (age = 23.80 ± 1.82 years, height = 176.95 ± 5.21 cm, mass = 83.49 ± 10.43 kg, 1 repetition maximum [1RM] front squat = 131.02 ± 21.32 kg) volunteered. A dynamic warm-up and warm-up sets of front squat were performed. Eccentric hooks were added to the barbell. They descended for 3 seconds, until eccentric hooks released, and performed the concentric phase as fast as possible. There were 3 randomly ordered conditions with the concentric phase always at 90% 1RM and the eccentric phase at 105, 110, and 120% of 1RM. Two repetitions were performed for each condition. A repeated measures analysis of variance was used to determine differences. For peak velocity, there were main effects for time and condition (p front squat is a precursor.

  7. Virulence evolution at the front line of spreading epidemics.

    Science.gov (United States)

    Griette, Quentin; Raoul, Gaël; Gandon, Sylvain

    2015-11-01

    Understanding and predicting the spatial spread of emerging pathogens is a major challenge for the public health management of infectious diseases. Theoretical epidemiology shows that the speed of an epidemic is governed by the life-history characteristics of the pathogen and its ability to disperse. Rapid evolution of these traits during the invasion may thus affect the speed of epidemics. Here we study the influence of virulence evolution on the spatial spread of an epidemic. At the edge of the invasion front, we show that more virulent and transmissible genotypes are expected to win the competition with other pathogens. Behind the front line, however, more prudent exploitation strategies outcompete virulent pathogens. Crucially, even when the presence of the virulent mutant is limited to the edge of the front, the invasion speed can be dramatically altered by pathogen evolution. We support our analysis with individual-based simulations and we discuss the additional effects of demographic stochasticity taking place at the front line on virulence evolution. We confirm that an increase of virulence can occur at the front, but only if the carrying capacity of the invading pathogen is large enough. These results are discussed in the light of recent empirical studies examining virulence evolution at the edge of spreading epidemics. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  8. Submesoscale CO2 variability across an upwelling front off Peru

    Science.gov (United States)

    Köhn, Eike E.; Thomsen, Sören; Arévalo-Martínez, Damian L.; Kanzow, Torsten

    2017-12-01

    As a major source for atmospheric CO2, the Peruvian upwelling region exhibits strong variability in surface fCO2 on short spatial and temporal scales. Understanding the physical processes driving the strong variability is of fundamental importance for constraining the effect of marine emissions from upwelling regions on the global CO2 budget. In this study, a frontal decay on length scales of 𝒪(10 km) was observed off the Peruvian coast following a pronounced decrease in down-frontal (equatorward) wind speed with a time lag of 9 h. Simultaneously, the sea-to-air flux of CO2 on the inshore (cold) side of the front dropped from up to 80 to 10 mmol m-2 day-1, while the offshore (warm) side of the front was constantly outgassing at a rate of 10-20 mmol m-2 day-1. Based on repeated ship transects the decay of the front was observed to occur in two phases. The first phase was characterized by a development of coherent surface temperature anomalies which gained in amplitude over 6-9 h. The second phase was characterized by a disappearance of the surface temperature front within 6 h. Submesoscale mixed-layer instabilities were present but seem too slow to completely remove the temperature gradient in this short time period. Dynamics such as a pressure-driven gravity current appear to be a likely mechanism behind the evolution of the front.

  9. Towards a Psychological Construct of Being Moved

    Science.gov (United States)

    Menninghaus, Winfried; Wagner, Valentin; Hanich, Julian; Wassiliwizky, Eugen; Kuehnast, Milena; Jacobsen, Thomas

    2015-01-01

    The emotional state of being moved, though frequently referred to in both classical rhetoric and current language use, is far from established as a well-defined psychological construct. In a series of three studies, we investigated eliciting scenarios, emotional ingredients, appraisal patterns, feeling qualities, and the affective signature of being moved and related emotional states. The great majority of the eliciting scenarios can be assigned to significant relationship and critical life events (especially death, birth, marriage, separation, and reunion). Sadness and joy turned out to be the two preeminent emotions involved in episodes of being moved. Both the sad and the joyful variants of being moved showed a coactivation of positive and negative affect and can thus be ranked among the mixed emotions. Moreover, being moved, while featuring only low-to-mid arousal levels, was experienced as an emotional state of high intensity; this applied to responses to fictional artworks no less than to own-life and other real, but media-represented, events. The most distinctive findings regarding cognitive appraisal dimensions were very low ratings for causation of the event by oneself and for having the power to change its outcome, along with very high ratings for appraisals of compatibility with social norms and self-ideals. Putting together the characteristics identified and discussed throughout the three studies, the paper ends with a sketch of a psychological construct of being moved. PMID:26042816

  10. Towards a psychological construct of being moved.

    Directory of Open Access Journals (Sweden)

    Winfried Menninghaus

    Full Text Available The emotional state of being moved, though frequently referred to in both classical rhetoric and current language use, is far from established as a well-defined psychological construct. In a series of three studies, we investigated eliciting scenarios, emotional ingredients, appraisal patterns, feeling qualities, and the affective signature of being moved and related emotional states. The great majority of the eliciting scenarios can be assigned to significant relationship and critical life events (especially death, birth, marriage, separation, and reunion. Sadness and joy turned out to be the two preeminent emotions involved in episodes of being moved. Both the sad and the joyful variants of being moved showed a coactivation of positive and negative affect and can thus be ranked among the mixed emotions. Moreover, being moved, while featuring only low-to-mid arousal levels, was experienced as an emotional state of high intensity; this applied to responses to fictional artworks no less than to own-life and other real, but media-represented, events. The most distinctive findings regarding cognitive appraisal dimensions were very low ratings for causation of the event by oneself and for having the power to change its outcome, along with very high ratings for appraisals of compatibility with social norms and self-ideals. Putting together the characteristics identified and discussed throughout the three studies, the paper ends with a sketch of a psychological construct of being moved.

  11. Flooring in front of the feed bunk affects feeding behavior and use of freestalls by dairy cows.

    Science.gov (United States)

    Tucker, C B; Weary, D M; de Passillé, A M; Campbell, B; Rushen, J

    2006-06-01

    In 2 experiments we assessed how preferences, time budgets, and feeding behavior of dairy cows change in response to flooring surfaces in front of the feed bunk. In Experiment 1, 12 nonlactating dairy cattle were individually housed with access to 2 standing platforms filled with either concrete or sawdust. In Experiment 2, 24 nonlactating dairy cattle were given access to either concrete or Animat rubber flooring in front of the feed bunk. In Experiment 1, cows preferred the sawdust to the concrete flooring. In both experiments, cows provided with a softer floor in front of the feed bunk spent more time standing near the feed bunk without eating (Experiment 1: 67 vs. 40 min/d on sawdust vs. concrete, respectively, SEM = 5.6 min/d; Experiment 2: 176 vs. 115 min/d on Animat vs. concrete, respectively, SEM = 20.5 min/d) compared with when they were kept on concrete. The increased time spent at the feed bunk was due to a combination of more frequent eating and standing bouts, indicating that cows were more willing to move on nonconcrete flooring. Total time spent eating was significantly greater on the softer floor in Experiment 2, but not in Experiment 1 (Exp. 1: 289 vs. 275 min/d on sawdust and concrete, respectively, SEM = 7.3 min/d; Exp. 2: 330 vs. 289 min/d on Animat and concrete, respectively, SEM = 15.4), although feed intake was increased on the sawdust treatment in Experiment 1. Cows spent significantly more time lying in the feed alley when the flooring was rubber (219 vs. 53 min/d on Animat and concrete, SEM = 53.6 min/d), perhaps because the lying area in Experiment 2 was inadequate. In conclusion, cows prefer to stand on softer flooring in front of the feed bunk, and are more willing to move on and spend more time standing in front of the feed bunk when provided with softer flooring. These results indicate that cows find softer flooring surfaces more comfortable to stand on than concrete, and highlight the importance of evaluating the comfort of the

  12. 40 CFR 63.486 - Batch front-end process vent provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vent provisions... Batch front-end process vent provisions. (a) Batch front-end process vents. Except as specified in paragraph (b) of this section, owners and operators of new and existing affected sources with batch front...

  13. Ocean fronts drive marine fishery production and biogeochemical cycling

    Science.gov (United States)

    Woodson, C. Brock; Litvin, Steven Y.

    2015-01-01

    Long-term changes in nutrient supply and primary production reportedly foreshadow substantial declines in global marine fishery production. These declines combined with current overfishing, habitat degradation, and pollution paint a grim picture for the future of marine fisheries and ecosystems. However, current models forecasting such declines do not account for the effects of ocean fronts as biogeochemical hotspots. Here we apply a fundamental technique from fluid dynamics to an ecosystem model to show how fronts increase total ecosystem biomass, explain fishery production, cause regime shifts, and contribute significantly to global biogeochemical budgets by channeling nutrients through alternate trophic pathways. We then illustrate how ocean fronts affect fishery abundance and yield, using long-term records of anchovy–sardine regimes and salmon abundances in the California Current. These results elucidate the fundamental importance of biophysical coupling as a driver of bottom–up vs. top–down regulation and high productivity in marine ecosystems. PMID:25624488

  14. Direct Numerical Simulations of Reacting Fronts in Incompressible Flows

    Science.gov (United States)

    Vladimirova, N.; Cattaneo, F.; Malagoli, A.; Oberman, A.; Ruchayskiy, 0.; Rosner, R.

    2000-11-01

    We perform direct numerical simulations of an advected scalar field which diffuses and reacts according to a nonlinear reaction law. The goal of the simulations is to study flame stability with respect to initial conditions, and to determine how the bulk burning rate of the reaction front is affected by an imposed flow. We focus for simplicity on the cases of an imposed periodic shear or cellular flow. The interaction between the reaction front and the applied flow is determined by the following parameters: (a) the ratio between the laminar front thickness and the shear length scale, (b) the ratio between the laminar flame speed and the characteristic flow velocity, and (c) the ratio between heat conductivity and material diffusion (Lewis Number). We compare the numerical results with recent work of P. Constantin and collaborators, in particularly, their prediction for flame stability and analytical upper and lower bounds for the bulk burning rate.

  15. FRONT AXLE OF MERCEDES AMG GT. MODELLING IN AUTODESK INVENTOR

    Directory of Open Access Journals (Sweden)

    COROLENCU Eduard – Narcis

    2017-05-01

    Full Text Available This paper analyzes the front axle of the Mercedes AMG GT model, as so as the graphical representation of the axle and of the subassemblies of suspension system and steering system, using the AutoCAD and Autodesk Inventor software. The paper include the steps for made the 3D model of the front axle in order to highlight the advantages of suspension and steering system, the function of this systems and methods for manufacturing of these. The 3D model presents a suite of complex surfaces. This type of surfaces is often designed with non-analytical means. The main commands and options used in Autodesk Inventor software were presented and explained. All the component parts of the front axle were modelled and assembled according to their functional role. Finally, the models were rendered in order to have a realistic appearance.

  16. Stability of a laminar flame front propagating within a tube

    Energy Technology Data Exchange (ETDEWEB)

    Salamandra, G.D.; Maiorov, N.I.

    1983-01-01

    The present study examines the deformation of a flame propagating in a semi-closed horizontal tube under the action of perturbations artificially created on the flame surface by brief action of a transverse electrical field on the combustion zone. The fuel mixture used was a dry methane-air mixture containing 10% CH4, which produced a flame front with relatively low convexity. Flame front propagation was recorded by high-speed photographic methods. Interpretation of the photographs reveals that the magnitude of the perturbations increases by an exponential law; fine scale perturbations on the flame surface are suppressed by coarse scale perturbations, while the stable curved form of the flame front in the tube is ensured by the stabilizing action of the tube walls.

  17. Concepts for a Muon Accelerator Front-End

    Energy Technology Data Exchange (ETDEWEB)

    Stratakis, Diktys [Fermilab; Berg, Scott [Brookhaven; Neuffer, David [Fermilab

    2017-03-16

    We present a muon capture front-end scheme for muon based applications. In this Front-End design, a proton bunch strikes a target and creates secondary pions that drift into a capture channel, decaying into muons. A series of rf cavities forms the resulting muon beams into a series of bunches of differerent energies, aligns the bunches to equal central energies, and initiates ionization cooling. We also discuss the design of a chicane system for the removal of unwanted secondary particles from the muon capture region and thus reduce activation of the machine. With the aid of numerical simulations we evaluate the performance of this Front-End scheme as well as study its sensitivity against key parameters such as the type of target, the number of rf cavities and the gas pressure of the channel.

  18. Ocean fronts drive marine fishery production and biogeochemical cycling.

    Science.gov (United States)

    Woodson, C Brock; Litvin, Steven Y

    2015-02-10

    Long-term changes in nutrient supply and primary production reportedly foreshadow substantial declines in global marine fishery production. These declines combined with current overfishing, habitat degradation, and pollution paint a grim picture for the future of marine fisheries and ecosystems. However, current models forecasting such declines do not account for the effects of ocean fronts as biogeochemical hotspots. Here we apply a fundamental technique from fluid dynamics to an ecosystem model to show how fronts increase total ecosystem biomass, explain fishery production, cause regime shifts, and contribute significantly to global biogeochemical budgets by channeling nutrients through alternate trophic pathways. We then illustrate how ocean fronts affect fishery abundance and yield, using long-term records of anchovy-sardine regimes and salmon abundances in the California Current. These results elucidate the fundamental importance of biophysical coupling as a driver of bottom-up vs. top-down regulation and high productivity in marine ecosystems.

  19. Light-Front Holography and Non-Perturbative QCD

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; de Teramond, Guy F.; /Costa Rica U.

    2009-12-09

    The combination of Anti-de Sitter space (AdS) methods with light-front holography leads to a semi-classical first approximation to the spectrum and wavefunctions of meson and baryon light-quark bound states. Starting from the bound-state Hamiltonian equation of motion in QCD, we derive relativistic light-front wave equations in terms of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. These equations of motion in physical space-time are equivalent to the equations of motion which describe the propagation of spin-J modes in anti-de Sitter (AdS) space. Its eigenvalues give the hadronic spectrum, and its eigenmodes represent the probability distribution of the hadronic constituents at a given scale. Applications to the light meson and baryon spectra are presented. The predicted meson spectrum has a string-theory Regge form M{sup 2} = 4{kappa}{sup 2}(n + L + S = 2); i.e., the square of the eigenmass is linear in both L and n, where n counts the number of nodes of the wavefunction in the radial variable {zeta}. The space-like pion form factor is also well reproduced. One thus obtains a remarkable connection between the description of hadronic modes in AdS space and the Hamiltonian formulation of QCD in physical space-time quantized on the light-front at fixed light-front time {tau}. The model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method in order to systematically include the QCD interaction terms.

  20. Lock-exchange experiments with an autocatalytic reaction front

    Science.gov (United States)

    Malham, I. Bou; Jarrige, N.; Martin, J.; Rakotomalala, N.; Talon, L.; Salin, D.

    2010-12-01

    A viscous lock-exchange gravity current corresponds to the reciprocal exchange of two fluids of different densities in a horizontal channel. The resulting front between the two fluids spreads as the square root of time, with a diffusion coefficient reflecting the buoyancy, viscosity, and geometrical configuration of the current. On the other hand, an autocatalytic reaction front between a reactant and a product may propagate as a solitary wave, namely, at a constant velocity and with a stationary concentration profile, resulting from the balance between molecular diffusion and chemical reaction. In most systems, the fluid left behind the front has a different density leading to a lock-exchange configuration. We revisit, with a chemical reaction, the classical situation of lock-exchange. We present an experimental analysis of buoyancy effects on the shape and the velocity of the iodate arsenous acid autocatalytic reaction fronts, propagating in horizontal rectangular channels and for a wide range of aspect ratios (1/3 to 20) and cylindrical tubes. We do observe stationary-shaped fronts, spanning the height of the cell and propagating along the cell axis. Our data support the contention that the front velocity and its extension are linked to each other and that their variations scale with a single variable involving the diffusion coefficient of the lock-exchange in the absence of chemical reaction. This analysis is supported by results obtained with lattice Bathnagar-Gross-Krook (BGK) simulations Jarrige et al. [Phys. Rev. E 81, 06631 (2010)], in other geometries (like in 2D simulations by Rongy et al. [J. Chem. Phys. 127, 114710 (2007)] and experiments in cylindrical tubes by Pojman et al. [J. Phys. Chem. 95, 1299 (1991)]), and for another chemical reaction Schuszter et al. [Phys. Rev. E 79, 016216 (2009)].

  1. Differential sensor in front photopyroelectric technique: II. Experimental

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, R; Moreno, I; Araujo-Andrade, C [Facultad de Fisica, Universidad Autonoma de Zacatecas, Calz. Solidaridad Esquina Paseo de la Bufa s/n, CP 98060, Zacatecas, Zac. (Mexico); MarIn, E [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada-Instituto Politecnico Nacional, Legaria 694, Col. Irrigacion, CP 11500, Mexico D.F. (Mexico); Cruz-Orea, A [Departamento de Fisica, CINVESTAV-IPN, Av. IPN No. 2508, Col. San Pedro Zacatenco, CP 07360, Mexico D.F. (Mexico); Pichardo-Molina, J L, E-mail: rumen@fisica.uaz.edu.m [Centro de Investigaciones en Optica, Loma del Bosque 115, Loma del Campestre, CP 37150, Leon, Guanajuato (Mexico)

    2009-06-21

    We describe the differential cell design and the experimental (optical and electronic) setup for the differential front photopyroelectric technique, whose theory has been developed in the first part of this paper (Ivanov et al 2008 J. Phys. D: Appl. Phys. 41 085106). We will show first how the direct (non-differential) front photopyroelectric theory described in our previous paper reproduces well the experimental results. The usefulness of the differential technique is demonstrated by means of experimental measurements of the thermal effusivity in binary ethanol-water and glycerol-water mixtures, based on a theoretical methodology that simplifies the measurement procedure and diminishes the experimental uncertainty.

  2. Taking charge: front-line nurse leadership development.

    Science.gov (United States)

    Schwarzkopf, Ruth; Sherman, Rose O; Kiger, Anna J

    2012-04-01

    The recent Institute of Medicine (2010) report, The Future of Nursing: Leading Change, Advancing Health, included a recommendation that nurses at all levels should be prepared and enabled to lead change to advance health care in the United States. Historically, in most organizations, nursing leadership development programs have focused on nurses in management or executive roles rather than those working in front-line leadership roles. This article describes a front-line leadership development initiative developed by Tenet Healthcare Corporation and attended by 400 charge nurses. Program development, evaluation, and lessons learned that can be applied in other organizations are discussed. Copyright 2012, SLACK Incorporated.

  3. Cold Fronts in Clusters of Galaxies: Observations and Modeling

    Science.gov (United States)

    Markevitch, Maxim

    2012-01-01

    Mergers of galaxy clusters -- some of the most energetic events in the Universe -- produce disturbances in hot intracluster medium, such as shocks and cold fronts, that can be used as tools to study the physics of galaxy clusters. Cold fronts may constrain viscosity and the structure and strength of the cluster magnetic fields. Combined with radio data, these observations also shed light on the production of ultrarelativistic particles that are known to coexist with the cluster thermal plasma. This talk will summarize the current X-ray observations of cluster mergers, as well as some recent radio data and high resolution hydrodynamic simulations.

  4. General characteristics of current in front of Port Said, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed S. Elsharkawy

    2017-06-01

    Full Text Available This paper is a preliminary investigation of the general characteristics of the current in front of the coastal Mediterranean city: Port Said, Egypt. The study of the current regime in front of Port Said helps environmental engineers to tackle problems as marine port sedimentation and shoreline changes. Surface and bottom current recordings at a single offshore station of depth 104 m located at 31° 34.90′ N, 32° 30.01′ E have been subject to statistical analysis. The measurements showed unexpectedly that bottom currents were relatively stronger than surface currents during May-99.

  5. Overtopping of Rubble Mound Breakwaters with Front Reservoir

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Andersen, Thomas Lykke

    2007-01-01

    The design and performance of breakwaters with front reservoir are discussed on the basis of physical 2-D model tests with a number of cross sections, in which vertopping discharge and spatial distribution, wave forces on inner parapet walls, and stability of reservoir armour were studied....... The sensitivity of these quantities to the width of the reservoir is discussed. It is demonstrated that front reservoir solutions are more economical than conventional cross section solutions, such as bermed structures and mild slope structures, in cases where low crests and small overtopping discharges...

  6. CMOS front-end electronics for radiation sensors

    CERN Document Server

    AUTHOR|(CDS)2071026

    2015-01-01

    This book offers a comprehensive treatment of front-end electronics for radiation detection. It discusses the fundamental principles of signal processing for radiation detectors and describes circuits at the level of functional building blocks, omitting transistor-level implementation. It also covers important system-level topics commonly found in the world of front-end electronics for radiation sensors. The book develops the topics in detail, with a constant focus on practical problems. It also provides real implementation examples that offer insights and stimuli for more experienced engineers already working in the field.

  7. ATLAS LAr Phase upgrade of the Front End Electronics

    CERN Document Server

    Newcomer, Mitchel; The ATLAS collaboration

    2016-01-01

    The Phase II upgrade of the ATLAS Liquid Argon detector includes a 17 bit dynamic range front end amplifier with a two or three gain multi‐pole shaper employing CR‐(RC)n shaping. Each gain stage of the shaper will be followed by a 40Msps, 14b dynamic range, 12‐13b ENOB digitizer, serializer and fiber optic driver. A study is underway to see if a single technology (65nm or 130nm CMOS) will be suitable for all blocks up to the optical Link, enabling consideration of the development a Front End System On a Chip (FESOC).

  8. Osteoma in a blue-fronted Amazon parrot (Amazona aestiva).

    Science.gov (United States)

    Cardoso, João Felipe Rito; Levy, Marcelo Guilherme Bezerra; Liparisi, Flavia; Romão, Mario Antonio Pinto

    2013-09-01

    Osteoma is an uncommon bone formation documented in avian species and other animals. A blue-fronted Amazon parrot (Amazona aestiva) with clinical respiratory symptoms was examined because of a hard mass present on the left nostril. Radiographs suggested a bone tumor, and the mass was surgically excised. Histopathologic examination revealed features of an osteoma. To our knowledge, this is the first description of an osteoma in a blue-fronted Amazon parrot. Osteoma should be considered as a differential diagnosis in birds with respiratory distress and swelling of the nostril.

  9. Front Range Forest Health Partnership Phase 1 feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Volkin, P

    1998-09-01

    The Front Range Forest Health Partnership is an alliance of individuals, citizen groups, federal, state, private, and nonprofit organizations that formed to promote forest health restoration and reduce fire risks on Colorado's Front Range. The partnership promotes selective thinning to restore forest health and supports economically feasible end uses for wood waste materials. The Phase I study was initiated to determine the environmental and economic feasibility of using wood wastes from forested and urban areas for the production of fuel-grade ethanol.

  10. Fronts and thermohaline structure of the Brazil-Malvinas Confluence System

    Science.gov (United States)

    Severov, Dmitri Nikolaevich; Pshennikov, Valentina; Remeslo, Alexsandr Vasilievich

    2012-05-01

    Fronts and thermohaline structure of the Brazil-Malvinas Confluence System (BMCS) are studied from climatic data, "Marathon Exp. Leg.8, 1984" data, and Sea surface temperature (SST) data base "ds277-Reynolds" (1981-2000). The South Atlantic Central Water (SACW) is divided in two main types: tropical (TW) and subtropical water (ST). Water masses, Fronts, Inter-Frontal and Frontal Zones are analysed and classified: (a) the water masses: Tropical Low-Salinity Water, Tropical Surface Water, Tropical Tropospheric Water, Subtropical Low-Salinity Water, Subtropical Surface Water, Subtropical Tropospheric Water. T,S characteristics of intermediate, deep and bottom water defined by different authors are confirmed and completed; (b) the Inter-Frontal Zones: Tropical/Brazil Current Zone, Subtropical Zone and Subantarctic Zone; (c) the Frontal Zones: Subtropical, Subantarctic and Polar, and (d) the Fronts: Subtropical Front of the Brazil Current, Principal Subtropical Front, North Subtropical Front, Subtropical Surface Front, South Subtropical Front, Subantarctic Surface Front, Subantarctic Front and Polar Front. Several stable T-S relationships are found below the friction layer and at the Fronts. The maximum gradient of the oceanographic characteristics occurs at the Brazil Current Front, which can be any of the subtropical Fronts, depending on season. Minimum mean depth of the pycnocline coincides with the Fronts of the BMCS, indicating the paths of low-salinity shelf waters into the open ocean. In the work it is shown how to recover the horizontal and vertical thermohaline structure of waters from satellite data RSMAS SST.

  11. Moving KML geometry elements within Google Earth

    Science.gov (United States)

    Zhu, Liang-feng; Wang, Xi-feng; Pan, Xin

    2014-11-01

    During the process of modeling and visualizing geospatial information on the Google Earth virtual globe, there is an increasing demand to carry out such operations as moving geospatial objects defined by KML geometry elements horizontally or vertically. Due to the absence of the functionality and user interface for performing the moving transformation, it is either hard or impossible to interactively move multiple geospatial objects only using the existing Google Earth desktop application, especially when the data sets are in large volume. In this paper, we present a general framework and associated implementation methods for moving multiple KML geometry elements within Google Earth. In our proposed framework, we first load KML objects into the Google Earth plug-in, and then extract KML geometry elements from the imported KML objects. Subsequently, we interactively control the movement distance along a specified orientation by employing a custom user interface, calculate the transformed geographic location for each KML geometry element, and adjust geographic coordinates of the points in each KML objects. And finally, transformed KML geometry elements can be displayed in Google Earth for 3D visualization and spatial analysis. A key advantage of the proposed framework is that it provides a simple, uniform and efficient user interface for moving multiple KML geometry elements within Google Earth. More importantly, the proposed framework and associated implementations can be conveniently integrated into other customizable Google Earth applications to support interactively visualizing and analyzing geospatial objects defined by KML geometry elements.

  12. Monitoring moving queries inside a safe region.

    Science.gov (United States)

    Al-Khalidi, Haidar; Taniar, David; Betts, John; Alamri, Sultan

    2014-01-01

    With mobile moving range queries, there is a need to recalculate the relevant surrounding objects of interest whenever the query moves. Therefore, monitoring the moving query is very costly. The safe region is one method that has been proposed to minimise the communication and computation cost of continuously monitoring a moving range query. Inside the safe region the set of objects of interest to the query do not change; thus there is no need to update the query while it is inside its safe region. However, when the query leaves its safe region the mobile device has to reevaluate the query, necessitating communication with the server. Knowing when and where the mobile device will leave a safe region is widely known as a difficult problem. To solve this problem, we propose a novel method to monitor the position of the query over time using a linear function based on the direction of the query obtained by periodic monitoring of its position. Periodic monitoring ensures that the query is aware of its location all the time. This method reduces the costs associated with communications in client-server architecture. Computational results show that our method is successful in handling moving query patterns.

  13. Maxwell Equations for Slow-Moving Media

    Science.gov (United States)

    Rozov, Andrey

    2015-12-01

    In the present work, the Minkowski equations obtained on the basis of theory of relativity are used to describe electromagnetic fields in moving media. But important electromagnetic processes run under non-relativistic conditions of slow-moving media. Therefore, one should carry out its description in terms of classical mechanics. Hertz derived electrodynamic equations for moving media within the frame of classical mechanics on the basis of the Maxwell theory. His equations disagree with the experimental data concerned with the moving dielectrics. In the paper, a way of description of electromagnetic fields in slow-moving media on the basis of the Maxwell theory within the frame of classical mechanics is offered by combining the Hertz approach and the experimental data concerned with the movement of dielectrics in electromagnetic fields. Received Maxwell equations lack asymmetry in the description of the reciprocal electrodynamic action of a magnet and a conductor and conform to known experimental data. Comparative analysis of the Minkowski and Maxwell models is carried out.

  14. ELECTROMAGNETIC APPARATUS FOR MOVING A ROD

    Science.gov (United States)

    Young, J.N.

    1957-08-20

    An electromagnetic device for moving an object in a linear path by increments is described. The device is specifically adapted for moving a neutron absorbing control rod into and out of the core of a reactor and consists essentially of an extension member made of magnetic material connected to one end of the control rod and mechanically flexible to grip the walls of a sleeve member when flexed, a magnetic sleeve member coaxial with and slidable between limit stops along the flexible extension, electromagnetic coils substantially centrally located with respect to the flexible extension to flex the extension member into gripping engagement with the sleeve member when ener gized, moving electromagnets at each end of the sleeve to attract the sleeve when energized, and a second gripping electromagnet positioned along the flexible extension at a distance from the previously mentioned electromagnets for gripping the extension member when energized. In use, the second gripping electromagnet is deenergized, the first gripping electromagnet is energized to fix the extension member in the sleeve, and one of the moving electromagnets is energized to attract the sleeve member toward it, thereby moving the control rod.

  15. Online Risk Prediction for Indoor Moving Objects

    DEFF Research Database (Denmark)

    Ahmed, Tanvir; Pedersen, Torben Bach; Calders, Toon

    2016-01-01

    or inaccuracy at any step can make the bag risky, i.e., the bag may be delayed at the airport or sent to a wrong airport. In this paper, we propose a novel probabilistic approach for predicting the risk of an indoor moving object in real-time. We propose a probabilistic flow graph (PFG) and an aggregated......Technologies such as RFID and Bluetooth have received considerable attention for tracking indoor moving objects. In a time-critical indoor tracking scenario such as airport baggage handling, a bag has to move through a sequence of locations until it is loaded into the aircraft. Inefficiency...... probabilistic flow graph (APFG) that capture the historical object transitions and the durations of the transitions. In the graphs, the probabilistic information is stored in a set of histograms. Then we use the flow graphs for obtaining a risk score of an online object and use it for predicting its riskiness...

  16. Fermions in light front transverse lattice quantum chromodynamics

    Indian Academy of Sciences (India)

    boost invariant wave functions. Furthermore, rotations in the transverse plane remains kinematical. Since vacuum processes receive contributions only from k· =0, Fock vacuum becomes an eigenstate of the light front Hamiltonian in the interacting theory (with the exception of theories with spontaneous symmetry breaking) ...

  17. Vocal matching by orange-fronted conures (Aratinga canicularis)

    DEFF Research Database (Denmark)

    Balsby, Thorsten J S; Bradbury, Jack W

    2009-01-01

    in groups with variable composition, and lack multiple alarm signals. Here we present the results of interactive playbacks in a fission/fusion parrot species, the orange-fronted conjure (Aratinga canicularis), that provide evidence of vocal matching. A randomly selected loud contact call (chee) per trial...

  18. Propagating fronts in reaction-transport systems with memory

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, A. [Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314 (United States)], E-mail: ayadav1@lsu.edu; Fedotov, Sergei [School of Mathematics, University of Manchester, Manchester M60 1DQ (United Kingdom)], E-mail: sergei.fedotov@manchester.ac.uk; Mendez, Vicenc [Grup de Fisica Estadistica, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)], E-mail: vicenc.mendez@uab.es; Horsthemke, Werner [Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314 (United States)], E-mail: whorsthe@smu.edu

    2007-11-26

    In reaction-transport systems with non-standard diffusion, the memory of the transport causes a coupling of reactions and transport. We investigate the effect of this coupling for systems with Fisher-type kinetics and obtain a general analytical expression for the front speed. We apply our results to the specific case of subdiffusion.

  19. Thermal front propagation in variable aperture fracture–matrix system

    Indian Academy of Sciences (India)

    the cold water and hot fractured rock to access the feasibility of geothermal energy production. Propagation of thermal fronts in a single phase fractured porous media was first studied by. Lauwerier (1955). Lauwerier developed an analytical solution for injection of hot water into oil bearing fractured rocks. Gringarten & Sauty ...

  20. Accidental entrapment of cats in front-loading washing machines.

    Science.gov (United States)

    Stewart, Sarah A; Gaunt, Matthew C; Taylor, Susan M; Snead, Elizabeth C R

    2010-09-01

    Two clinical cases of accidental entrapment of cats in front-loading washing machines are described. One cat died the day after presentation as a result of aspiration pneumonia and head trauma, despite supportive care. The second cat survived with supportive treatment, but developed dermatologic complications 10 d later.

  1. Extreme weather caused by concurrent cyclone, front and thunderstorm occurrences.

    Science.gov (United States)

    Dowdy, Andrew J; Catto, Jennifer L

    2017-01-11

    Phenomena such as cyclones, fronts and thunderstorms can cause extreme weather in various regions throughout the world. Although these phenomena have been examined in numerous studies, they have not all been systematically examined in combination with each other, including in relation to extreme precipitation and extreme winds throughout the world. Consequently, the combined influence of these phenomena represents a substantial gap in the current understanding of the causes of extreme weather events. Here we present a systematic analysis of cyclones, fronts and thunderstorms in combination with each other, as represented by seven different types of storm combinations. Our results highlight the storm combinations that most frequently cause extreme weather in various regions of the world. The highest risk of extreme precipitation and extreme wind speeds is found to be associated with a triple storm type characterized by concurrent cyclone, front and thunderstorm occurrences. Our findings reveal new insight on the relationships between cyclones, fronts and thunderstorms and clearly demonstrate the importance of concurrent phenomena in causing extreme weather.

  2. Front Matter - JTSiskom Volume 5 Nomor 2 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-05-01

    Full Text Available Artikel ini berisi front-matter JTSiskom Volume 5 Nomor 2 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  3. Front Matter - JTSiskom Volume 5 Nomor 3 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-07-01

    Full Text Available Artikel ini berisi front-matter JTSiskom Volume 5 Nomor 3 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  4. Front Matter - JTSiskom Volume 5 Nomor 4 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-10-01

    Full Text Available Artikel ini berisi front-matter JTSiskom Volume 5 Nomor 4 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  5. Front Matters - JTSiskom Volume 5 Nomor 1 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-01-01

    Full Text Available Artikel ini berisi front-matters JTSiskom Volume 5 Nomor 1 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  6. PACE3 - front-end chip for the CMS Preshower

    CERN Multimedia

    Aspel, Paul

    2003-01-01

    This is PACE3 which is the front-end chip for the CMS Preshower. In fact PACE3 is the combination of two ASICs called Delta3 and PACEAM3. Delta3 is on the left and PACEAM3 is on the right. The two ASICs are bonded together and then packaged within a single 196 pin fpBGA package.

  7. Oceanic fronts: transition zones for bacterioplankton community composition

    Science.gov (United States)

    Baltar, F.; Currie, K.; Stuck, E.; Roosa, S.; Morales, S.

    2016-02-01

    Oceanic fronts are widespread mesoscale features that exist in the boundary between different water masses. Bacterioplankton (including Bacteria and Archaea) drive oceanic biogeochemical cycles, regulating the composition of Earth's atmosphere and influencing climate. Despite the recognized importance of bacterioplankton on the marine biogeochemical cycles and the ubiquitousness of fronts, the effect of frontal zones on the distribution of bacterioplankton community remains unknown. Using 16S rRNA gene sequencing coupled with a high spatial resolution analysis of the physical properties of the water masses, we demonstrate strong shifts in bacterioplankton community composition (BCC) across the Subtropical Frontal Zone off New Zealand. Transition between water masses resulted in a clear modification of the dominant taxa and a significant increase in community dissimilarity. Our results, linking physical oceanography and marine molecular ecology, support the strong role of oceanic frontal zones in delimiting the distribution of bacterioplankton in the ocean, where fronts serve as clear transition zones, indicating boundaries for bacterioplankton distribution in the ocean. Owing to the widespread abundance of fronts in the marine environment, future efforts should focus on confirming their roles in demarking bacterioplankton distribution and whether they act as indicators of ecosystem process changes. This would allow a better understanding of the forces that control energy flow in the ocean as well as the cycling of compounds that influence climate change, and concomitantly building more accurate models of global biogeochemical cycles.

  8. Variational formulation based analysis on growth of yield front in ...

    African Journals Online (AJOL)

    The present study investigates the growth of elastic-plastic front in rotating solid disks of non-uniform thickness having exponential and parabolic geometry variation. The problem is solved through an extension of a variational method in elastoplastic regime. The formulation is based on von-Mises yield criterion and linear ...

  9. Water chemistry of Rocky Mountain Front Range aquatic ecosystems

    Science.gov (United States)

    Robert C. Musselman; Laura Hudnell; Mark W. Williams; Richard A. Sommerfeld

    1996-01-01

    A study of the water chemistry of Colorado Rocky Mountain Front Range alpine/subalpine lakes and streams in wilderness ecosystems was conducted during the summer of 1995 by the USDA Forest Service Arapaho and Roosevelt National Forests and Rocky Mountain Forest and Range Experiment Station, and the University of Colorado Institute of Alpine and Arctic Research. Data...

  10. The Front-End System For MARE In Milano

    Science.gov (United States)

    Arnaboldi, Claudio; Pessina, Gianluigi

    2009-12-01

    The first phase of MARE consists of 72 μ-bolometers composed each of a crystal of AgReO4 readout by Si thermistors. The spread in the thermistor characteristics and bolometer thermal coupling leads to different energy conversion gains and optimum operating points of the detectors. Detector biasing levels and voltage gains are completely remote-adjustable by the front end system developed, the subject of this paper, achieving the same signal range at the input of the DAQ system. The front end consists of a cold buffer stage, a second pseudo differential stage followed by a gain stage, an antialiasing filter, and a battery powered detector biasing set up. The DAQ system can be used to set all necessary parameters of the electronics remotely, by writing to a μ-controller located on each board. Fiber optics are used for the serial communication between the DAQ and the front end. To suppress interference noise during normal operation, the clocked devices of the front end are maintained in sleep-mode, except during the set-up phase of the experiment. An automatic DC detector characterization procedure is used to establish the optimum operating point of every detector of the array. A very low noise level has been achieved: about 3nV/□Hz at 1 Hz and 1 nV/□Hz for the white component, high frequencies.

  11. Consumer preferences for front-of-pack calories labelling

    NARCIS (Netherlands)

    Kleef, van E.; Trijp, van J.C.M.; Paeps, F.; Fernández-Celemín, L.

    2008-01-01

    Objective In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms

  12. Front and backside processed thin film electronic devices

    Science.gov (United States)

    Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

    2010-10-12

    This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  13. Bibliometric analysis of acupuncture research fronts and their ...

    African Journals Online (AJOL)

    Background: Considerable research has been conducted on acupuncture worldwide. This study chronologically examined the changing features and research fronts of acupuncture and elucidated the differences among the six most productive countries. Methods: Bibliographic coupling is a powerful tool for identifying the ...

  14. Iterative wave-front reconstruction in the Fourier domain.

    Science.gov (United States)

    Bond, Charlotte Z; Correia, Carlos M; Sauvage, Jean-François; Neichel, Benoit; Fusco, Thierry

    2017-05-15

    The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data set which conform to specific boundary requirements, whereas wave-front sensor data is typically defined over a circular domain (the telescope pupil). Here we present an iterative Gerchberg routine modified for the purposes of discrete wave-front reconstruction which adapts the measurement data (wave-front sensor slopes) for Fourier analysis, fulfilling the requirements of the fast Fourier transform (FFT) and providing accurate reconstruction. The routine is used in the adaptation step only and can be coupled to any other Wiener-like or least-squares method. We compare simulations using this method with previous Fourier methods and show an increase in performance in terms of Strehl ratio and a reduction in noise propagation for a 40×40 SPHERE-like adaptive optics system. For closed loop operation with minimal iterations the Gerchberg method provides an improvement in Strehl, from 95.4% to 96.9% in K-band. This corresponds to ~ 40 nm improvement in rms, and avoids the high spatial frequency errors present in other methods, providing an increase in contrast towards the edge of the correctable band.

  15. The role of pH fronts in reversible electroporation.

    Directory of Open Access Journals (Sweden)

    Pablo Turjanski

    Full Text Available We present experimental measurements and theoretical predictions of ion transport in agar gels during reversible electroporation (ECT for conditions typical to many clinical studies found in the literature, revealing the presence of pH fronts emerging from both electrodes. These results suggest that pH fronts are immediate and substantial. Since they might give rise to tissue necrosis, an unwanted condition in clinical applications of ECT as well as in irreversible electroporation (IRE and in electrogenetherapy (EGT, it is important to quantify their extent and evolution. Here, a tracking technique is used to follow the space-time evolution of these pH fronts. It is found that they scale in time as t(½, characteristic of a predominantly diffusive process. Comparing ECT pH fronts with those arising in electrotherapy (EChT, another treatment applying constant electric fields whose main goal is tissue necrosis, a striking result is observed: anodic acidification is larger in ECT than in EChT, suggesting that tissue necrosis could also be greater. Ways to minimize these adverse effects in ECT are suggested.

  16. Morale among French colonial troops on the Western Front during ...

    African Journals Online (AJOL)

    Morale among French colonial troops on the Western Front during World War I: 1914–1918. ... Bringing men to a foreign land and culture to fight in a new type of horrific war was quite a strain on these 600 000 soldiers.2 The bulk of these soldiers were drawn from North and West Africa, with smaller numbers coming from ...

  17. Microstrip-Transmission-Line Shock-Front Sensor

    Science.gov (United States)

    Leiweke, Robert J.; Smith, William C.

    1993-01-01

    Microstrip-transmission-line sensor measures velocities of low-overpressure shock fronts and offers dynamic range needed for measurements both far from and near explosions. Fabricated easily, relatively inexpensive, and repaired in field. In addition, basic geometry modified easily, as needed.

  18. Analytic Sharp Fronts for the Surface Quasi-Geostrophic Equation

    Science.gov (United States)

    Fefferman, Charles; Rodrigo, José L.

    2011-04-01

    We study the evolution of sharp fronts for the Surface Quasi-Geostrophic equation in the context of analytic functions. We showed that, even though the equation contains operators of order higher than 1, by carefully studying the evolution of the second derivatives it can be adapted to fit an abstract version of the Cauchy-Kowaleski Theorem.

  19. Wave-front-engineered grating mirrors for VCSELs

    DEFF Research Database (Denmark)

    Carletti, Luca; Malureanu, Radu; Mørk, Jesper

    2012-01-01

    High-index-contrast grating mirrors featuring beam steering abilities for the transmitted beam as well as high reflectivity over a broad bandwidth are suggested. Gratings designed to provide control over the wave front of the transmitted beam are numerically investigated. The proposed structures ...

  20. Calibration method for direct conversion receiver front-ends

    Directory of Open Access Journals (Sweden)

    R. Müller

    2008-05-01

    Full Text Available Technology induced process tolerances in analog circuits cause device characteristics different from specification. For direct conversion receiver front-ends a system level calibration method is presented. The malfunctions of the devices are compensated by tuning dominant circuit parameters. Thereto optimization techniques are applied which use measurement values and special evaluation functions.

  1. FACILITATING RADICAL FRONT-END INNOVATION THROUGH TARGETED HR PRACTICES

    DEFF Research Database (Denmark)

    Aagaard, Annabeth

    2017-01-01

    study of the Danish pharmaceutical company, H. Lundbeck A/S, and explorative studies of seven European and American pharmaceutical and biotech companies. The study aims to show how companies can apply HR practices in ways that actively supports the development of radical front end innovation. The value...

  2. A socio-internactive framework for the fuzzy front end

    NARCIS (Netherlands)

    Smulders, Frido E.; van den Broek, Egon; van der Voort, Mascha C.; Fernandes, A.; Teixeira, A.; Natal Jorge, R.

    2007-01-01

    This paper aims to illustrate that the dominating rational-analytic perspective on the Fuzzy Front End (FFE) of innovation could benefit by a complementary socio-interactive perspective that addresses the social processes during the FFE. We have developed a still fledgling socio-interactive

  3. An operational map of the Polish Coastal Front 1970

    DEFF Research Database (Denmark)

    Nielsen, Thomas Theis; Svenningsen, Stig Roar; Tinning, Morten

    2016-01-01

    The map of the Operational Plan for the Coastal Front, from Poland 1970 forms the basis for this paper. The map portraits the blueprint of the combined operational war plans for the Polish military in the late 1960’s and 70’s. It details the offensive against NATO countries and their forces in No...

  4. Smart front-ends, from vision to design

    NARCIS (Netherlands)

    Roermund, H.M. van; Baltus, P.; Bezooijen, A. van; Hegt, J.A.; Lopelli, E.; Mahmoudi, R.; Radulov, G.I.; Vidojkovic, M.

    2009-01-01

    An integral multi-disciplinary chain optimization based on a high-level cascaded Shannon-based channel modeling is proposed. It is argued that the analog part of the front-end (FE) will become a bottleneck in the overall chain. This requires a FE-centric design approach, aiming for maximizing the

  5. Covariance of light-front models: pair current

    NARCIS (Netherlands)

    Melo, J.P.B.C. de; Frederico, T.; Naus, H.W.L.; Sauer, P.U.

    1999-01-01

    We compute the + component, i.e., j+ = j0 + j3, of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component q+ = q0 + q3. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the

  6. Direct Writing with Tilted-Front Femtosecond Pulses.

    Science.gov (United States)

    Patel, Aabid; Svirko, Yuri; Durfee, Charles; Kazansky, Peter G

    2017-10-10

    Shaping light fields in both space and time provides new degrees of freedom to manipulate light-matter interaction on the ultrafast timescale. Through this exploitation of the light field, a greater appreciation of spatio-temporal couplings in focusing has been gained, shedding light on previously unexplored parameters of the femtosecond light pulse, including pulse front tilt and wavefront rotation. Here, we directly investigate the effect of major spatio-temporal couplings on light-matter interaction and reveal unambiguously that in transparent media, pulse front tilt gives rise to the directional asymmetry of the ultrafast laser writing. We demonstrate that the laser pulse with a tilted intensity front deposits energy more efficiently when writing along the tilt than when writing against, producing either an isotropic damage-like or a birefringent nanograting structure. The directional asymmetry in the ultrafast laser writing is qualitatively described in terms of the interaction of a void trapped within the focal volume by the gradient force from the tilted intensity front and the thermocapillary force caused by the gradient of temperature. The observed instantaneous transition from the damage-like to nanograting modification after a finite writing length in a transparent dielectric is phenomenologically described in terms of the first-order phase transition.

  7. Different profiles of the aerial start phase in front crawl

    NARCIS (Netherlands)

    Seifert, L.; Vantorre, J.; Lemaitre, F.; Chollet, D.; Toussaint, H.M.; Vilas-Boas, J.P.

    2010-01-01

    This study analyzed the kinematics and kinetics (jumping ability) of the aerial start phase in 11 elite front crawl sprinters. The aim was to determine whether a particular start technique leads to a short 15 m start time or whether several start profiles contribute equally well. All swimmers

  8. On the propagation of a coupled saturation and pressure front

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, D. W.

    2010-12-01

    Using an asymptotic technique, valid for a medium with smoothly varying heterogeneity, I derive an expression for the velocity of a propagating, coupled saturation and pressure front. Due to the nonlinearity of the governing equations, the velocity of the propagating front depends upon the magnitude of the saturation and pressure changes across the front in addition to the properties of the medium. Thus, the expression must be evaluated in conjunction with numerical reservoir simulation. The propagation of the two-phase front is governed by the background saturation distribution, the saturation-dependent component of the fluid mobility, the porosity, the permeability, the capillary pressure function, the medium compressibility, and the ratio of the slopes of the relative permeability curves. Numerical simulation of water injection into a porous layer saturated with a nonaqueous phase liquid indicates that two modes of propagation are important. The fastest mode of propagation is a pressure-dominated disturbance that travels through the saturated layer. This is followed, much later, by a coupled mode with a large saturation change. These two modes are also observed in a simulation using a heterogeneous porous layer. A comparison between the propagation times estimated from the results of the numerical simulation and predictions from the asymptotic expression indicates overall agreement.

  9. Chiral Boson Theory on the Light-Front

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Prem P.

    1999-09-16

    The framework for describing the quantized theory of chiral boson is discussed. It avoids the conflict with the requirement of the principle of microcausality as is found in the conventional treatment. The discussion of the Floreanini-Jackiw model and its modified version for describing the chiral boson becomes very transparent on the light-front.

  10. Precision forging of front fan blades, abridged version

    Science.gov (United States)

    Voigtlaender, O.; Degenhardt, H.

    1983-10-01

    The manufacturing of titanium alloy front fan blades with ready-for-assembly contact surfaces on conventional counterblow hammers is reported. Thermal contraction and elastic die-deformation were determined and the tooling was fabricated by computerized design. Forging trials give fan blades which dimensionally and metallurgically meet the requirements.

  11. 5-D interpolation with wave-front attributes

    Science.gov (United States)

    Xie, Yujiang; Gajewski, Dirk

    2017-11-01

    Most 5-D interpolation and regularization techniques reconstruct the missing data in the frequency domain by using mathematical transforms. An alternative type of interpolation methods uses wave-front attributes, that is, quantities with a specific physical meaning like the angle of emergence and wave-front curvatures. In these attributes structural information of subsurface features like dip and strike of a reflector are included. These wave-front attributes work on 5-D data space (e.g. common-midpoint coordinates in x and y, offset, azimuth and time), leading to a 5-D interpolation technique. Since the process is based on stacking next to the interpolation a pre-stack data enhancement is achieved, improving the signal-to-noise ratio (S/N) of interpolated and recorded traces. The wave-front attributes are determined in a data-driven fashion, for example, with the Common Reflection Surface (CRS method). As one of the wave-front-attribute-based interpolation techniques, the 3-D partial CRS method was proposed to enhance the quality of 3-D pre-stack data with low S/N. In the past work on 3-D partial stacks, two potential problems were still unsolved. For high-quality wave-front attributes, we suggest a global optimization strategy instead of the so far used pragmatic search approach. In previous works, the interpolation of 3-D data was performed along a specific azimuth which is acceptable for narrow azimuth acquisition but does not exploit the potential of wide-, rich- or full-azimuth acquisitions. The conventional 3-D partial CRS method is improved in this work and we call it as a wave-front-attribute-based 5-D interpolation (5-D WABI) as the two problems mentioned above are addressed. Data examples demonstrate the improved performance by the 5-D WABI method when compared with the conventional 3-D partial CRS approach. A comparison of the rank-reduction-based 5-D seismic interpolation technique with the proposed 5-D WABI method is given. The comparison reveals that

  12. INFLUENCE OF MOVING LOADS ON CURVED BRIDGES

    OpenAIRE

    Thamer A. Z*, Jabbbar S. A

    2016-01-01

    The behavior of a curved slab bridge decks with uniform thickness under moving load is investigated in this study. Three radii of curvature "R" are used (25, 50 and 75m) along with the straight bridge, R = ∞. The decks are simply supported or clamped along the radial edges and free at the circular edges. The AASHTO[1] standard axle load of the truck H20-44 is used and assumed to move in three track positions on the bridge. The finite element method is employed for the analysis and the ANSYS 5...

  13. DIFFUSION BACKGROUND MODEL FOR MOVING OBJECTS DETECTION

    Directory of Open Access Journals (Sweden)

    B. V. Vishnyakov

    2015-05-01

    Full Text Available In this paper, we propose a new approach for moving objects detection in video surveillance systems. It is based on construction of the regression diffusion maps for the image sequence. This approach is completely different from the state of the art approaches. We show that the motion analysis method, based on diffusion maps, allows objects that move with different speed or even stop for a short while to be uniformly detected. We show that proposed model is comparable to the most popular modern background models. We also show several ways of speeding up diffusion maps algorithm itself.

  14. Moving Shadow Detection in Video Using Cepstrum

    Directory of Open Access Journals (Sweden)

    Fuat Cogun

    2013-01-01

    Full Text Available Moving shadows constitute problems in various applications such as image segmentation and object tracking. The main cause of these problems is the misclassification of the shadow pixels as target pixels. Therefore, the use of an accurate and reliable shadow detection method is essential to realize intelligent video processing applications. In this paper, a cepstrum-based method for moving shadow detection is presented. The proposed method is tested on outdoor and indoor video sequences using well-known benchmark test sets. To show the improvements over previous approaches, quantitative metrics are introduced and comparisons based on these metrics are made.

  15. On the atmosphere of a moving body

    DEFF Research Database (Denmark)

    Pedersen, Johan Rønby; Aref, Hassan

    2010-01-01

    demonstrate numerically that, indeed, regions of fluid follow the body in its motion. We see this as an example of the stability of Kolmogorov-Arnold-Moser tori. These observations of an atmosphere around a moving body with no circulation around it appear to be new. (C) 2010 American Institute of Physics......We explore whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid "atmosphere" with it in its motion. Somewhat surprisingly, the answer appears to be "yes." When the body is elongated and the motion is dominated by rotation, we...

  16. Memory for moving and static images.

    Science.gov (United States)

    Matthews, W J; Benjamin, Clare; Osborne, Claire

    2007-10-01

    Despite the substantial interest in memory for complex pictorial stimuli, there has been virtually no research comparing memory for static scenes with that for their moving counterparts. We report that both monochrome and color moving images are better remembered than static versions of the same stimuli at retention intervals up to one month. When participants studied a sequence of still images, recognition performance was the same as that for single static images. These results are discussed within a theoretical framework which draws upon previous studies of scene memory, face recognition, and representational momentum.

  17. Querying moving objects detected by sensor networks

    CERN Document Server

    Bestehorn, Markus

    2012-01-01

    Declarative query interfaces to Sensor Networks (SN) have become a commodity. These interfaces allow access to SN deployed for collecting data using relational queries. However, SN are not confined to data collection, but may track object movement, e.g., wildlife observation or traffic monitoring. While rational approaches are well suited for data collection, research on ""Moving Object Databases"" (MOD) has shown that relational operators are unsuitable to express information needs on object movement, i.e., spatio-temporal queries. ""Querying Moving Objects Detected by Sensor Networks"" studi

  18. Partner (Dis)agreement on Moving Desires and the Subsequent Moving Behaviour of Couples (discussion paper)

    NARCIS (Netherlands)

    Coulter, R.; Van Ham, M.; Feijten, P.

    2011-01-01

    Residential mobility decisions are known to be made at the household level. However, most empirical analyses of residential mobility relate moving behaviour to the housing and neighbourhood satisfaction and pre-move thoughts of individuals. If partners in a couple do not share evaluations of

  19. 77 FR 16566 - Submission for OMB Review, Comment Request, Proposed Collection: Let's Move Museums, Let's Move...

    Science.gov (United States)

    2012-03-21

    ... Move Museums, Let's Move Gardens AGENCY: Institute of Museum and Library Services, The National... Institute of Museum and Library Services announces that the following information collection has been..., Institute of Museum and Library Services, 1800 M Street NW., 9th Floor, Washington, DC 20036. Telephone: 202...

  20. Extension of the modal wave-front reconstruction algorithm to non-uniform illumination.

    Science.gov (United States)

    Ma, Xiaoyu; Mu, Jie; Rao, ChangHui; Yang, Jinsheng; Rao, XueJun; Tian, Yu

    2014-06-30

    Attempts are made to eliminate the effects of non-uniform illumination on the precision of wave-front measurement. To achieve this, the relationship between the wave-front slope at a single sub-aperture and the distributions of the phase and light intensity of the wave-front were first analyzed to obtain the relevant theoretical formulae. Then, based on the principle of modal wave-front reconstruction, the influence of the light intensity distribution on the wave-front slope is introduced into the calculation of the reconstruction matrix. Experiments were conducted to prove that the corrected modal wave-front reconstruction algorithm improved the accuracy of wave-front reconstruction. Moreover, the correction is conducive to high-precision wave-front measurement using a Hartmann wave-front sensor in the presence of non-uniform illumination.

  1. Consumer preferences for front-of-pack calories labelling.

    Science.gov (United States)

    van Kleef, Ellen; van Trijp, Hans; Paeps, Frederic; Fernández-Celemín, Laura

    2008-02-01

    In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms or relative to recommended daily intake, whether it should be expressed in per serving or per 100 g and whether the information should be further brought alive for consumers in terms of what the extra calorie intake implies in relation to activity levels. The present study aimed at providing more insight into consumers' appreciation of front-of-pack labelling of caloric content of food products and their specific preferences for alternative execution formats for such information in Europe. For this purpose, eight executions of front-of-pack calorie flags were designed and their appeal and information value were extensively discussed with consumers through qualitative research in four different countries (Germany, The Netherlands, France and the UK). The results show that calories are well-understood and that participants were generally positive about front-of-pack flags, particularly when flags are uniform across products. The most liked flags are the simpler flags depicting only the number of calories per serving or per 100 g, while more complex flags including references to daily needs or exercise and the flag including a phrase referring to balanced lifestyle were least preferred. Some relevant differences between countries were observed. Although participants seem to be familiar with the notion of calories, they do not seem to fully understand how to apply them. From the results, managerial implications for the design and implementation of front-of-pack calorie labelling as well as important directions for future research are discussed.

  2. Consumer preferences for front-of-pack calories labelling

    Science.gov (United States)

    van Kleef, Ellen; van Trijp, Hans; Paeps, Frederic; Fernández-Celemín, Laura

    2008-01-01

    Objective In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms or relative to recommended daily intake, whether it should be expressed in per serving or per 100 g and whether the information should be further brought alive for consumers in terms of what the extra calorie intake implies in relation to activity levels. The present study aimed at providing more insight into consumers’ appreciation of front-of-pack labelling of caloric content of food products and their specific preferences for alternative execution formats for such information in Europe. Design For this purpose, eight executions of front-of-pack calorie flags were designed and their appeal and information value were extensively discussed with consumers through qualitative research in four different countries (Germany, The Netherlands, France and the UK). Results The results show that calories are well-understood and that participants were generally positive about front-of-pack flags, particularly when flags are uniform across products. The most liked flags are the simpler flags depicting only the number of calories per serving or per 100 g, while more complex flags including references to daily needs or exercise and the flag including a phrase referring to balanced lifestyle were least preferred. Some relevant differences between countries were observed. Although participants seem to be familiar with the notion of calories, they do not seem to fully understand how to apply them. Conclusion From the results, managerial implications for the design and implementation of front-of-pack calorie labelling as well as important directions for future research are discussed. PMID:17601362

  3. We are all angels: acting, reclaiming and moving beyond survivorship.

    Science.gov (United States)

    Anderson, Ariane B

    2014-01-01

    This article aspires to an embodiment of dynamic living versus mere survival. The term cancer survivor, including a survivor who is in remission, has been legitimated (Berger and Luckmann, The social construction of reality, p. 94 1967) by language which creates knowledge of what a cancer survivor is and does. Because we act under descriptions (Hacking, The social construction of what?, p. 103 1999), those of us who have passed through illnesses such as cancer not only have been given the name and the idea of survivor, we have assumed and conform to some or most of the characteristics assigned to it; examples of some of those characteristics are discussed throughout this project. Whether or not we choose to enact all that falls under the grammar of the classification of survivor, we still live with, create, and experience ourselves and others as legitimated by such a classification. The term survivor operates through a number of institutions (medical, capitalism, and media) resulting in individuals' awareness of such classifications about themselves and others. Many, if not most, who are aware of being classified as survivors may wish to modify or resist the constraining aspects of those classifications and their descriptions. Through layered accounts of interviews and prose, I interact with this term as one who is both caught in and wants to go against the stream of classification and description. I want to transcend what I know, yet I am aware that whatever story I make and tell is a part of the whole-my story is part of two other survivor's stories which I include in the following telling of my own. All of our stories matter. Still, I want to look beyond what is in front of me, move beyond it, dream. I do so with a desire to tell my story as part of other survivors' stories.

  4. Moving On: Young People and Substance Abuse

    Science.gov (United States)

    Daley, Kathryn; Chamberlain, Chris

    2009-01-01

    To help explain why some young people move from recreational drug use to substance abuse, twelve in-depth interviews were conducted with young people who had experienced problematic substance use. The data were supplemented by statistical data on 111 young people. The researchers found a variety of "structural" factors that help explain…

  5. Electromagnetic Force on a Moving Dipole

    Science.gov (United States)

    Kholmetskii, Alexander L.; Missevitch, Oleg V.; Yarman, T.

    2011-01-01

    We analyse the force acting on a moving dipole due to an external electromagnetic field and show that the expression derived in Vekstein (1997 "Eur. J. Phys." 18 113) is erroneous and suggest the correct equation for the description of this force. We also discuss the physical meaning of the relativistic transformation of current for a closed…

  6. Quantum correlation with moving beamsplitters in relativistic ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 59; Issue 2. Quantum correlation with moving beamsplitters in ... Zbinden1 Nicolas Gisin1 Antoine Suarez1 2. Group of Applied Physics, University of Geneva, 1211 Geneva 4, Switzerland; Center for Quantum Philosophy, P.O. Box 304, CH-8044 Zurich, Switzerland ...

  7. Strategic Game Moves Mediate Implicit Science Learning

    Science.gov (United States)

    Rowe, Elizabeth; Baker, Ryan S.; Asbell-Clarke, Jodi

    2015-01-01

    Educational games have the potential to be innovative forms of learning assessment, by allowing us to not just study their knowledge but the process that takes students to that knowledge. This paper examines the mediating role of players' moves in digital games on changes in their pre-post classroom measures of implicit science learning. We…

  8. Information Literacy Assessment: Moving beyond Computer Literacy

    Science.gov (United States)

    Hignite, Michael; Margavio, Thomas M.; Margavio, Geanie W.

    2009-01-01

    Information literacy is a concept that has evolved as a result of recent efforts to move technology-based instruction and research to a level above the long-held concepts previously associated with "computer literacy"; the focus of information literacy education being the development of students' abilities to construct/collect and…

  9. Electromagnetic Sources in a Moving Conducting Medium

    DEFF Research Database (Denmark)

    Johannsen, Günther

    1971-01-01

    The problem of an arbitrary source distribution in a uniformly moving, homogeneous, isotropic, nondispersive, conducting medium is solved. The technique used is to solve the problem in the rest system of the medium and then write the result in an appropriate four-dimensional, covariant form which...

  10. 39 CFR 777.23 - Moving expenses.

    Science.gov (United States)

    2010-07-01

    ... ACQUISITION POLICIES Uniform Relocation Assistance § 777.23 Moving expenses. (a) Eligibility. (1) Residential... and marketing studies. (ix) Advertisement of replacement location, not to exceed $1,500 (x..., machinery, or trade fixtures. (ii) Purchase of manufacturing materials, production supplies, product...

  11. Supportive Discourse Moves in Persian Requests

    Science.gov (United States)

    Nodoushan, Mohammad Ali Salmani; Allami, Hamid

    2011-01-01

    This paper reports the findings of a study designed to investigate the types of supportive discourse moves employed by Persian speakers in their Requestive Speech Acts. 372 respondents took a Discourse Completion Test (DCT) with six scenarios ranging from formal to informal degrees of Perceived Situational Seriousness, and returned 2232 Requestive…

  12. Developing Reading Comprehension with Moving Image Narratives

    Science.gov (United States)

    Maine, Fiona; Shields, Robin

    2015-01-01

    This paper reports the findings from a small-scale exploratory study that investigated how moving-image narratives might enable children to develop transferable reading comprehension strategies. Using short, animated, narrative films, 28 primary-aged children engaged in a 10-week programme that included the explicit instruction of comprehension…

  13. Moving Divertor Plates in a Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Zweben, H. Zhang

    2009-02-12

    Moving divertor plates could help solve some of the problems of the tokamak divertor through mechanical ingenuity rather than plasma physics. These plates would be passively heated on each pass through the tokamak and cooled and reprocessed outside the tokamak. There are many design options using varying plate shapes, orientations, motions, coatings, and compositions.

  14. Moving dislocations studied by nuclear magnetic resonance

    NARCIS (Netherlands)

    Hut, Gezinus

    1976-01-01

    In this thesis a new approach to the study of moving dislocations in crystalline solids during plastic deformation will be presented. Since the process of dislocation motion is made up of atomic movements nuclear magnetic resonance techniques should offer a possibility to determine the manner in

  15. Residual Analysis of Generalized Autoregressive Integrated Moving ...

    African Journals Online (AJOL)

    In this study, analysis of residuals of generalized autoregressive integrated moving average bilinear time series model was considered. The adequacy of this model was based on testing the estimated residuals for whiteness. Jarque-Bera statistic and squared-residual autocorrelations were used to test the estimated ...

  16. Electromagnetic Sources in Moving Simple Medium

    DEFF Research Database (Denmark)

    Johannsen, Günther

    1970-01-01

    A retarded potential tensor (4-vector) is derived in an arbitrary system of inertia for an arbitrary electromagnetic source in a moving homogeneous, isotropic, nondispersive, lossless dielectric. The velocity is uniform, and the result is relativistic correct. ©1970 The American Institute...

  17. Wave propagation in axially moving periodic strings

    DEFF Research Database (Denmark)

    Sorokin, Vladislav S.; Thomsen, Jon Juel

    2017-01-01

    The paper deals with analytically studying transverse waves propagation in an axially moving string with periodically modulated cross section. The structure effectively models various relevant technological systems, e.g. belts, thread lines, band saws, etc., and, in particular, roller chain drive...

  18. Moving frames for heart fiber geometry

    DEFF Research Database (Denmark)

    Piuze, Emmanuel; Sporring, Jon; Siddiqi, Kaleem

    2013-01-01

    fibers is central to our understanding of normal heart function. Motivated by a recent abstraction by Savadjiev et al. of heart wall fibers into generalized helicoid minimal surfaces, this paper develops an extension based on differential forms. The key idea is to use Maurer-Cartan’s method of moving...

  19. EPI moved in beam S3

    CERN Document Server

    1977-01-01

    The housing of the External Particle Identifier (EPI) is being moved to S3 beam. Test measurements with EPI were performed in the S3 beam between 20 and 110 GeV/c, before installing it behind BEBC. 110 GeV/c before

  20. Towards a Psychological Construct of Being Moved

    NARCIS (Netherlands)

    Menninghaus, Winfried; Wagner, Valentin; Hanich, Julian; Wassiliwizky, Eugen; Kuehnast, Milena; Jacobsen, Thomas

    2015-01-01

    The emotional state of being moved, though frequently referred to in both classical rhetoric and current language use, is far from established as a well-defined psychological construct. In a series of three studies, we investigated eliciting scenarios, emotional ingredients, appraisal patterns,

  1. Vibrations in a moving flexible robot arm

    Science.gov (United States)

    Wang, P. K. C.; Wei, Jin-Duo

    1987-01-01

    The vibration in a flexible robot arm modeled by a moving slender prismatic beam is considered. It is found that the extending and contracting motions have destabilizing and stabilizing effects on the vibratory motions, respectively. The vibration analysis is based on a Galerkin approximation with time-dependent basis functions. Typical numerical results are presented to illustrate the qualitative features of vibrations.

  2. Clutter Moves in Old Age Homecare

    DEFF Research Database (Denmark)

    Lutz, Peter

    2010-01-01

    cites general household clutter as a hazard in the domestic environment. In such reports moving around with cluttered things tends to threaten a dangerous outcome for older people. But what other feasible vistas emerge when the analytical attention is focused explicitly on relational movements between...

  3. Effective Density Queries of Continuously Moving Objects

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lin, D.; Ooi, B.C.

    2006-01-01

    In this paper, we study a newly emerging type of queries on moving objects - the density query. Basically, this query locates regions in the data space where the density of the objects is high. This type of queries is especially useful in Location Based Services (LBS). For example, in a traffic...

  4. housing tenure, residential moves and children's educational

    African Journals Online (AJOL)

    User

    ing of parents and whether residential moves experienced ... health and behavioural development of children. (Stiffman ... and whether the performance will see him/her to the next ... (herein called Children, Teachers, and Parents) .... Housing tenure has influence on families .... nificant from a policy stand point if it is to help.

  5. Holistic Processing of Static and Moving Faces

    Science.gov (United States)

    Zhao, Mintao; Bülthoff, Isabelle

    2017-01-01

    Humans' face ability develops and matures with extensive experience in perceiving, recognizing, and interacting with faces that move most of the time. However, how facial movements affect 1 core aspect of face ability--holistic face processing--remains unclear. Here we investigated the influence of rigid facial motion on holistic and part-based…

  6. A dynamic analysis of moving average rules

    NARCIS (Netherlands)

    Chiarella, C.; He, X.Z.; Hommes, C.H.

    2006-01-01

    The use of various moving average (MA) rules remains popular with financial market practitioners. These rules have recently become the focus of a number empirical studies, but there have been very few studies of financial market models where some agents employ technical trading rules of the type

  7. Moving Readers from Struggling to Proficient

    Science.gov (United States)

    Wolter, Deborah

    2017-01-01

    If we want to move children from struggling to read to being proficient readers, we must address the disparate ways that teachers respond to readers with varying abilities. Restorative practices, akin to restorative justice, build relationships, make connections, and foster a reader's sense of ownership and empowerment. What would happen if…

  8. DESIGN OF MEDICAL RADIOMETER FRONT-END FOR IMPROVED PERFORMANCE

    Science.gov (United States)

    Klemetsen, Ø.; Birkelund, Y.; Jacobsen, S. K.; Maccarini, P. F.; Stauffer, P. R.

    2011-01-01

    We have investigated the possibility of building a singleband Dicke radiometer that is inexpensive, small-sized, stable, highly sensitive, and which consists of readily available microwave components. The selected frequency band is at 3.25–3.75 GHz which provides a reasonable compromise between spatial resolution (antenna size) and sensing depth for radiometry applications in lossy tissue. Foreseen applications of the instrument are non-invasive temperature monitoring for breast cancer detection and temperature monitoring during heating. We have found off-the-shelf microwave components that are sufficiently small (radiometers have been realized: one is a conventional design with the Dicke switch at the front-end to select either the antenna or noise reference channels for amplification. The second design places a matched pair of low noise amplifiers in front of the Dicke switch to reduce system noise figure. Numerical simulations were performed to test the design concepts before building prototype PCB front-end layouts of the radiometer. Both designs provide an overall power gain of approximately 50 dB over a 500 MHz bandwidth centered at 3.5 GHz. No stability problems were observed despite using triple-cascaded amplifier configurations to boost the thermal signals. The prototypes were tested for sensitivity after calibration in two different water baths. Experiments showed superior sensitivity (36% higher) when implementing the low noise amplifier before the Dicke switch (close to the antenna) compared to the other design with the Dicke switch in front. Radiometer performance was also tested in a multilayered phantom during alternating heating and radiometric reading. Empirical tests showed that for the configuration with Dicke switch first, the switch had to be locked in the reference position during application of microwave heating to avoid damage to the active components (amplifiers and power meter). For the configuration with a low noise amplifier up front

  9. Group cohesion in foraging meerkats: follow the moving 'vocal hot spot'.

    Science.gov (United States)

    Gall, Gabriella E C; Manser, Marta B

    2017-04-01

    Group coordination, when 'on the move' or when visibility is low, is a challenge faced by many social living animals. While some animals manage to maintain cohesion solely through visual contact, the mechanism of group cohesion through other modes of communication, a necessity when visual contact is reduced, is not yet understood. Meerkats (Suricata suricatta), a small, social carnivore, forage as a cohesive group while moving continuously. While foraging, they frequently emit 'close calls', soft close-range contact calls. Variations in their call rates based on their local environment, coupled with individual movement, produce a dynamic acoustic landscape with a moving 'vocal hotspot' of the highest calling activity. We investigated whether meerkats follow such a vocal hotspot by playing back close calls of multiple individuals to foraging meerkats from the front and back edge of the group simultaneously. These two artificially induced vocal hotspots caused the group to spatially elongate and split into two subgroups. We conclude that meerkats use the emergent dynamic call pattern of the group to adjust their movement direction and maintain cohesion. Our study describes a highly flexible mechanism for the maintenance of group cohesion through vocal communication, for mobile species in habitats with low visibility and where movement decisions need to be adjusted continuously to changing environmental conditions.

  10. Moving to a New Town. A Relocation Guide.

    Science.gov (United States)

    Rackliffe, Gary, Ed.; Pearson, Nancy, Ed.

    Designed to help those who must consider relocating to secure employment, this relocation guide provides answers to a number of questions pertaining to moving, money management, and adjusting to a new community. Various aspects of deciding to move are covered, including reasons for moving, thinking of a move as permanent, feelings of homesickness,…

  11. Move Sequences in Graduate Research Paper Introductions and Conclusions

    Science.gov (United States)

    Madrunio, Marilu Rañosa

    2012-01-01

    Graduate students submit academic papers at the end of the term as part of their coursework. Such papers contain introduction moves which may be troublesome and conclusion moves which may contain sub-moves not really required. This paper is aimed at assessing what particular moves are employed in the introduction and conclusion sections of 21…

  12. MOVES2014 for Experienced Users, September 2014 Webinar Slides

    Science.gov (United States)

    This webinar assumes a basic knowledge of past versions of the MOtor Vehicle Emission Simulator (MOVES) and includes a demonstration of the conversion of MOVES2010b input files to MOVES2014 format, changes to the MOVES GUI, and new input options.

  13. A New Formula for Front Slope Recession of Berm Breakwaters

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Burcharth, Hans F.

    2010-01-01

    The front slope stability of breakwaters with a homogeneous berm was studied in a large number of two dimensional model tests at Aalborg University, Denmark. The results are presented together with a new formula for prediction of the berm recession which is the most important parameter for descri......The front slope stability of breakwaters with a homogeneous berm was studied in a large number of two dimensional model tests at Aalborg University, Denmark. The results are presented together with a new formula for prediction of the berm recession which is the most important parameter...... for describing the reshaping. The formula has also been calibrated and validated against model test data from other researchers. The significance of the new design formula is that it predicts berm recession much better than the existing methods, especially in case of more stable structures....

  14. Delivering Faster Congestion Feedback with the Mark-Front Strategy

    Science.gov (United States)

    Liu, Chunlei; Jain, Raj

    2001-01-01

    Computer networks use congestion feedback from the routers and destinations to control the transmission load. Delivering timely congestion feedback is essential to the performance of networks. Reaction to the congestion can be more effective if faster feedback is provided. Current TCP/IP networks use timeout, duplicate Acknowledgement Packets (ACKs) and explicit congestion notification (ECN) to deliver the congestion feedback, each provides a faster feedback than the previous method. In this paper, we propose a markfront strategy that delivers an even faster congestion feedback. With analytical and simulation results, we show that mark-front strategy reduces buffer size requirement, improves link efficiency and provides better fairness among users. Keywords: Explicit Congestion Notification, mark-front, congestion control, buffer size requirement, fairness.

  15. Confounding adjustment through front-door blocking in longitudinal studies

    Directory of Open Access Journals (Sweden)

    Arvid Sjölander

    2013-03-01

    Full Text Available A common aim of epidemiological research is to estimate the causal effect of a particular exposure on a particular outcome. Towards this end, observed associations are often ‘adjusted’ for potential confounding variables. When the potential confounders are unmeasured, explicit adjustment becomes unfeasible. It has been demonstrated that causal effects can be estimated even in the presence of umeasured confounding, utilizing a method called ‘front-door blocking’. In this paper we generalize this method to longitudinal studies. We demonstrate that the method of front-door blocking poses a number of challenging statistical problems, analogous to the famous problems associ- ated with the method of ‘back-door blocking’.

  16. Metamaterial Huygens' surfaces: tailoring wave fronts with reflectionless sheets.

    Science.gov (United States)

    Pfeiffer, Carl; Grbic, Anthony

    2013-05-10

    Huygens' principle is a well-known concept in electromagnetics that dates back to 1690. Here, it is applied to develop designer surfaces that provide extreme control of electromagnetic wave fronts across electrically thin layers. These reflectionless surfaces, referred to as metamaterial Huygens' surfaces, provide new beam shaping, steering, and focusing capabilities. The metamaterial Huygens' surfaces are realized with two-dimensional arrays of polarizable particles that provide both electric and magnetic polarization currents to generate prescribed wave fronts. A straightforward design methodology is demonstrated and applied to develop a beam-refracting surface and a Gaussian-to-Bessel beam transformer. Metamaterial Huygens' surfaces could find a wide range of applications over the entire electromagnetic spectrum including single-surface lenses, polarization controlling devices, stealth technologies, and perfect absorbers.

  17. Front-end electronics for multichannel semiconductor detector systems

    CERN Document Server

    Grybos, P

    2010-01-01

    Front-end electronics for multichannel semiconductor detektor systems Volume 08, EuCARD Editorial Series on Accelerator Science and Technology The monograph is devoted to many different aspects related to front-end electronics for semiconductor detector systems, namely: − designing and testing silicon position sensitive detectors for HEP experiments and X-ray imaging applications, − designing and testing of multichannel readout electronics for semiconductor detectors used in X-ray imaging applications, especially for noise minimization, fast signal processing, crosstalk reduction and good matching performance, − optimization of semiconductor detection systems in respect to the effects of radiation damage. The monograph is the result mainly of the author's experience in the above-mentioned areas and it is an attempt of a comprehensive presentation of issues related to the position sensitive detection system working in a single photon counting mode and intended to X-ray imaging applications. The structure...

  18. Flexible Frequency Discrimination Subsystems for Reconfigurable Radio Front Ends

    Directory of Open Access Journals (Sweden)

    Carey-Smith Bruce E.

    2005-01-01

    Full Text Available The required flexibility of the software-defined radio front end may currently be met with better overall performance by employing tunable narrowband circuits rather than pursuing a truly wideband approach. A key component of narrowband transceivers is appropriate filtering to reduce spurious spectral content in the transmitter and limit out-of-band interference in the receiver. In this paper, recent advances in flexible, frequency-selective, circuit components applicable to reconfigurable SDR front ends are reviewed. The paper contains discussion regarding the filtering requirements in the SDR context and the use of intelligent, adaptive control to provide environment-aware frequency discrimination. Wide tuning-range frequency-selective circuit elements are surveyed including bandpass and bandstop filters and narrowband tunable antennas. The suitability of these elements to the mobile wireless SDR environment is discussed.

  19. The Role of Devices in Staging Front End Innovation

    DEFF Research Database (Denmark)

    Clausen, Christian; Yoshinaka, Yutaka

    2009-01-01

    This paper addresses Front End Innovation as an object for the management and staging of innovation processes. We examine the role which devices play in the managing of Front End Innovation, with inspiration from Science and Technology Studies (STS). The paper contributes to a new understanding...... into realisations. Inputs from different knowledge domains must be grappled with, both in terms of needing to be elucidated as well as synthesized, in the engineering design process. The paper argues that the existing research may be seen as a response to perceived difficulties in dealing with uncertain conditions...... in the innovative process of product development. The sole reliance on formalised models of planning, and rigid Stage-Gate models for product-based innovations in industry is seen to be wanting in this pursuit. What remains unaddressed is the role of models and other devices such as representations of users...

  20. Novel Front-end Electronics for Time Projection Chamber Detectors

    CERN Document Server

    García García, Eduardo José

    This work has been carried out in the European Organization for Nuclear Research (CERN) and it was supported by the European Union as part of the research and development towards the European detector the (EUDET) project, specifically for the International Linear Collider (ILC). In particle physics there are several different categories of particle detectors. The presented design is focused on a particular kind of tracking detector called Time Projection Chamber (TPC). The TPC provides a three dimensional image of electrically charged particles crossing a gaseous volume. The thesis includes a study of the requirements for future TPC detectors summarizing the parameters that the front-end readout electronics must fulfill. In addition, these requirements are compared with respect to the readouts used in existing TPC detectors. It is concluded that none of the existing front-end readout designs fulfill the stringent requirements. The main requirements for future TPC detectors are high integration, an increased n...

  1. Managing Front-End Innovation through Idea Markets at Novozymes

    DEFF Research Database (Denmark)

    Lauto, Giancarlo; Valentin, Finn; Hatzack, Frank

    2013-01-01

    Online collaboration is a powerful tool for boosting idea generation in large corporations. However, management may experience an overload of proposals from employees. To improve front-end innovation, the Danish industrial biotech company Novozymes implemented an internal idea competition in whic...... and screening and that active involvement of R&D management is a key success factor in any idea competition.......Online collaboration is a powerful tool for boosting idea generation in large corporations. However, management may experience an overload of proposals from employees. To improve front-end innovation, the Danish industrial biotech company Novozymes implemented an internal idea competition in which...... a relatively small number of highly motivated participants screened their colleagues' inventions through an "idea market." The idea competition fulfilled its goals of generating two ideas with high growth potential within a short time, uncovering and recombining old proposals that inventors had not previously...

  2. Radiation validation for the CMS HCAL front-end electronics

    CERN Document Server

    Whitmore, J; Elias, J E; Holm, S; Knickerbocker, K; Los, S; Rivetta, C; Ronzhin, A; Shenai, A; Yarema, R J; Zimmerman, T

    2002-01-01

    Over a 10 year operating period, the CMS Hadron Calorimeter (HCAL) detector will be exposed to radiation fields of approximately 1 kRad of total ionizing dose (TID) and a neutron fluence of 4E11 n/cm/sup 2 /. All front-end electronics must be qualified to survive this radiation environment with no degradation in performance. In addition, digital components in this environment can experience single-event upset (SEU) and single-event latch-up (SEL). A measurement of these single-event effects (SEE) for all components is necessary in order to understand the level that will be encountered. Radiation effects in all electronic components of the HCAL front-end system have been studied. Results from these studies will be presented. (17 refs).

  3. Fast Simulations of Gas Sloshing and Cold Front Formation

    Science.gov (United States)

    Roediger, E.; ZuHone, J. A.

    2012-01-01

    We present a simplified and fast method for simulating minor mergers between galaxy clusters. Instead of following the evolution of the dark matter halos directly by the N-body method, we employ a rigid potential approximation for both clusters. The simulations are run in the rest frame of the more massive cluster and account for the resulting inertial accelerations in an optimised way. We test the reliability of this method for studies of minor merger induced gas sloshing by performing a one-to-one comparison between our simulations and hydro+N-body ones. We find that the rigid potential approximation reproduces the sloshing-related features well except for two artifacts: the temperature just outside the cold fronts is slightly over-predicted, and the outward motion of the cold fronts is delayed by typically 200 Myr. We discuss reasons for both artifacts.

  4. Nucleon parton distributions in a light-front quark model

    Energy Technology Data Exchange (ETDEWEB)

    Gutsche, Thomas [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Lyubovitskij, Valery E. [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Tomsk Polytechnic University, Laboratory of Particle Physics, Mathematical Physics Department, Tomsk (Russian Federation); Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile); Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile)

    2017-02-15

    Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q{sub v}(x) and δq{sub v}(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

  5. A tsunami wave recorded near a glacier front

    Directory of Open Access Journals (Sweden)

    A. V. Marchenko

    2012-02-01

    Full Text Available We observed a tsunami wave near the glacier front in the Temple Fjord (Spitsbergen. Two temperature and pressure recorders were deployed on a wire from the ice approximately 300 m from the glacier front. A pressure recorder was located under them on the bottom. The vertical displacement of the ice was approximately 30 cm and the period of the tsunami wave was 90 s. We attribute the generation of this wave to the displacement of the glacier similarly to the landslide tsunami generated by the motion of a block of rocks down the sloping bottom. The glacier motion also generated a short-period (12 s deformation wave in the ice cover. The measurements allowed us to estimate the wave number of these waves and the Young's modulus of the ice.

  6. Atomic scale front propagation at the onset of frictional sliding.

    Science.gov (United States)

    Bonfanti, Silvia; Taloni, Alessandro; Negri, Carlotta; Sellerio, Alessandro; Manini, Nicola; Zapperi, Stefano

    2017-10-20

    Macroscopic frictional sliding emerges from atomic-scale interactions and processes at the contact interface, but bridging the gap between micro and macro scales still remains an unsolved challenge. Direct imaging of the contact surface and simultaneous measurement of stress fields during macroscopic frictional slip revealed the formation of crack precursors, questioning the traditional picture of frictional contacts described in terms of a single degree of freedom. Here we study the onset of frictional slip at atomic scale by simulating the motion of an aluminum block pushed by a slider on a copper substrate. We show the formation of dynamic slip front propagation and precursory activity that resemble macroscopic observations. The analysis of stress patterns during slip, however, reveals subtle effects due to the lattice structures which hinder a direct application of linear elastic fracture mechanics. Our results illustrate that dynamic front propagation arises already at the atomic scales and shed light on the connections between atomic-scale and macroscopic friction.

  7. High Dynamic Range Cognitive Radio Front Ends: Architecture to Evaluation

    Science.gov (United States)

    Ashok, Arun; Subbiah, Iyappan; Varga, Gabor; Schrey, Moritz; Heinen, Stefan

    2016-07-01

    Advent of TV white space digitization has released frequencies from 470 MHz to 790 MHz to be utilized opportunistically. The secondary user can utilize these so called TV spaces in the absence of primary users. The most important challenge for this coexistence is mutual interference. While the strong TV stations can completely saturate the receiver of the cognitive radio (CR), the cognitive radio spurious tones can disturb other primary users and white space devices. The aim of this paper is to address the challenges for enabling cognitive radio applications in WLAN and LTE. In this process, architectural considerations for the design of cognitive radio front ends are discussed. With high-IF converters, faster and flexible implementation of CR enabled WLAN and LTE are shown. The effectiveness of the architecture is shown by evaluating the CR front ends for compliance of standards namely 802.11b/g (WLAN) and 3GPP TS 36.101 (LTE).

  8. Front dynamics in fractional-order epidemic models.

    Science.gov (United States)

    Hanert, Emmanuel; Schumacher, Eva; Deleersnijder, Eric

    2011-06-21

    A number of recent studies suggest that human and animal mobility patterns exhibit scale-free, Lévy-flight dynamics. However, current reaction-diffusion epidemics models do not account for the superdiffusive spread of modern epidemics due to Lévy flights. We have developed a SIR model to simulate the spatial spread of a hypothetical epidemic driven by long-range displacements in the infective and susceptible populations. The model has been obtained by replacing the second-order diffusion operator by a fractional-order operator. Theoretical developments and numerical simulations show that fractional-order diffusion leads to an exponential acceleration of the epidemic's front and a power-law decay of the front's leading tail. Our results indicate the potential of fractional-order reaction-diffusion models to represent modern epidemics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Using noble gases to investigate mountain-front recharge

    Science.gov (United States)

    Manning, A.H.; Solomon, D.K.

    2003-01-01

    Mountain-front recharge is a major component of recharge to inter-mountain basin-fill aquifers. The two components of mountain-front recharge are (1) subsurface inflow from the mountain block (subsurface inflow), and (2) infiltration from perennial and ephemeral streams near the mountain front (stream seepage). The magnitude of subsurface inflow is of central importance in source protection planning for basin-fill aquifers and in some water rights disputes, yet existing estimates carry large uncertainties. Stable isotope ratios can indicate the magnitude of mountain-front recharge relative to other components, but are generally incapable of distinguishing subsurface inflow from stream seepage. Noble gases provide an effective tool for determining the relative significance of subsurface inflow, specifically. Dissolved noble gas concentrations allow for the determination of recharge temperature, which is correlated with recharge elevation. The nature of this correlation cannot be assumed, however, and must be derived for the study area. The method is applied to the Salt Lake Valley Principal Aquifer in northern Utah to demonstrate its utility. Samples from 16 springs and mine tunnels in the adjacent Wasatch Mountains indicate that recharge temperature decreases with elevation at about the same rate as the mean annual air temperature, but is on average about 2??C cooler. Samples from 27 valley production wells yield recharge elevations ranging from the valley elevation (about 1500 m) to mid-mountain elevation (about 2500 m). Only six of the wells have recharge elevations less than 1800 m. Recharge elevations consistently greater than 2000 m in the southeastern part of the basin indicate that subsurface inflow constitutes most of the total recharge in this area. ?? 2003 Published by Elsevier Science B.V.

  10. HomeFront Strong: Building Resiliency in Military Families

    Science.gov (United States)

    2017-09-01

    HFS mobile website and Administrative Console have the potential to significantly impact the well-being of military and veteran spouses/partners who...AWARD NUMBER: W81XWH-14-1-0362 TITLE: HomeFront Strong: Building Resiliency in Military Families PRINCIPAL INVESTIGATOR: Michelle Kees...Strong: Building Resiliency in Military Families 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Michelle Kees, PhD

  11. Frequency to Voltage Converter Analog Front-End Prototype

    Science.gov (United States)

    Mata, Carlos; Raines, Matthew

    2012-01-01

    The frequency to voltage converter analog front end evaluation prototype (F2V AFE) is an evaluation board designed for comparison of different methods of accurately extracting the frequency of a sinusoidal input signal. A configurable input stage is routed to one or several of five separate, configurable filtering circuits, and then to a configurable output stage. Amplifier selection and gain, filter corner frequencies, and comparator hysteresis and voltage reference are all easily configurable through the use of jumpers and potentiometers.

  12. Toward assessing the effects of crack front curvature /CFC/.

    Science.gov (United States)

    Swedlow, J. L.; Ritter, M. A.

    1972-01-01

    Consideration of the effect of crack front curvature (CFC) on the K calibration of five special geometries in which CFC occurs. The five cases considered include an elliptical crack in an infinite medium, an internal annular crack in a thick-walled cylinder, a through crack in a flat plate, a part-through crack in a plate, and an irregularly shaped crack in a solid. It is shown that K depends on CFC differently in each case.

  13. Assessment of Ibicella lutea for antibacterial agent front Staphylococcus aureus

    OpenAIRE

    Lisiane Martins Volcão; Tatiane Silveira Coelho; Alváro Vàsquez; Maria Pia Cerdeiras; Pedro Eduardo Almeida da Silva; Flávio Manoel Rodrigues da Silva Júnior; Daniela Fernandes Ramos

    2016-01-01

    Justificative and Objectives: the study aimed the assessment of the antibacterial activity of crude extracts and fractions of Ibicella lutea, front Staphylococcus aureus, thecombination of these compounds and cytotoxic activity. Methods: was used for antibacterial activity the Microdilution Test Broth, and performed the Checkerboard Test. The extracts showed antibacterial activity were submitted to the citotoxicity test, with macrophages cell and determination of the Selectivity Index (SI). R...

  14. MDT-ASD, CMOS front-end for ATLAS MDT

    CERN Document Server

    Posch, C; Oliver, J

    2007-01-01

    This document serves as the main reference and user`s manual for the read-out chip of the Monitored Drift Tubes in the ATLAS Muon Spectrometer. The eight-channel front-end ASIC is referred to as MDT-ASD. The document contains the requirements and complete specifications, a detailed description of the design with characteristics of all sub-circuits and building blocks, a comprehensive section on functionality and performance test results, and a complete bibliography.

  15. Automated reconstruction of neural trees using front re-initialization

    Science.gov (United States)

    Mukherjee, Amit; Stepanyants, Armen

    2012-02-01

    This paper proposes a greedy algorithm for automated reconstruction of neural arbors from light microscopy stacks of images. The algorithm is based on the minimum cost path method. While the minimum cost path, obtained using the Fast Marching Method, results in a trace with the least cumulative cost between the start and the end points, it is not sufficient for the reconstruction of neural trees. This is because sections of the minimum cost path can erroneously travel through the image background with undetectable detriment to the cumulative cost. To circumvent this problem we propose an algorithm that grows a neural tree from a specified root by iteratively re-initializing the Fast Marching fronts. The speed image used in the Fast Marching Method is generated by computing the average outward flux of the gradient vector flow field. Each iteration of the algorithm produces a candidate extension by allowing the front to travel a specified distance and then tracking from the farthest point of the front back to the tree. Robust likelihood ratio test is used to evaluate the quality of the candidate extension by comparing voxel intensities along the extension to those in the foreground and the background. The qualified extensions are appended to the current tree, the front is re-initialized, and Fast Marching is continued until the stopping criterion is met. To evaluate the performance of the algorithm we reconstructed 6 stacks of two-photon microscopy images and compared the results to the ground truth reconstructions by using the DIADEM metric. The average comparison score was 0.82 out of 1.0, which is on par with the performance achieved by expert manual tracers.

  16. Frontón Augusto Ibáñez

    OpenAIRE

    Gómez Santolaya, Javier

    2010-01-01

    Este proyecto consiste en el diseño, cálculo y presupuesto de la construcción de un frontón cubierto dotado de aseos, vestuarios, almacén, zona de gradas, etc. Dicho proyecto se llevará a cabo en el municipio de Viana, en la zona de las piscinas municipales para reforzar la oferta deportiva de las instalaciones. Ingeniería Técnica Industrial Industria Ingeniaritza Teknikoa

  17. Vertebral chondrosarcoma in a blue-fronted parrot (Amazona aestiva)

    OpenAIRE

    Blume, Guilherme Reis; Oliveira, Ayisa Rodrigues de; Mattioli, Mariana Portugal; Oliveira, Letícia Batelli de; Reis Junior, Janildo Ludolf; Sant'Ana, Fabiano José Ferreira de

    2015-01-01

    Chondrosarcoma is a malignant mesenchymal tumor in which the neoplastic cells produce cartilaginous matrix and is uncommonly described in birds. This report describes the clinical and pathological findings of one case of chondrosarcoma in a blue-fronted parrot (Amazona aestiva). Macroscopically a 3.6x3.5x1.8cm, nodular, ulcerated, and firm mass was identified in the dorsal synsacrum. Microscopically, the mass was composed of a monomorphic proliferation of pleomorphic spindle chondrocytes with...

  18. The 3He spectral function in light-front dynamics

    Directory of Open Access Journals (Sweden)

    Rinaldi Matteo

    2016-01-01

    Full Text Available A distorted spin-dependent spectral function for 3He is considered for the extraction of the transverse-momentum dependent parton distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers, where final state interactions are taken into account. The generalization of the analysis to a Poincaré covariant framework within the light-front dynamics is outlined.

  19. Taxonomy of Greater White-fronted Geese (Aves: Anatidae)

    Science.gov (United States)

    Banks, Richard C.

    2011-01-01

    Five subspecies of the Greater White-fronted Goose, Anser albifrons (Scopoli, 1769), have been named, all on the basis of wintering birds, and up to six subspecies have been recognized. There has been confusion over the application of some names, particularly in North America, because of lack of knowledge of the breeding ranges and type localities, and incorrect taxonomic decisions. There is one clinally varying subspecies in Eurasia, one that breeds in Greenland, and three in North America, one newly named herein.

  20. Light-front interpretation of proton generalized polarizabilities.

    Science.gov (United States)

    Gorchtein, M; Lorcé, C; Pasquini, B; Vanderhaeghen, M

    2010-03-19

    We extend the recently developed formalism to extract light-front quark charge densities from nucleon form factor data to the deformations of these quark charge densities when applying an external electric field. We show that the resulting induced polarizations can be extracted from proton generalized polarizabilities. The available data for the generalized electric polarizability of the proton yield a pronounced structure in its induced polarization at large transverse distances, which will be pinned down by forthcoming high precision virtual Compton scattering experiments.