WorldWideScience

Sample records for reach scale electronic

  1. Seventh meeting of the Global Alliance to Eliminate Lymphatic Filariasis: reaching the vision by scaling up, scaling down, and reaching out

    Science.gov (United States)

    2014-01-01

    This report summarizes the 7th meeting of the Global Alliance to Eliminate Lymphatic Filariasis (GAELF), Washington DC, November 18–19, 2012. The theme, “A Future Free of Lymphatic Filariasis: Reaching the Vision by Scaling Up, Scaling Down and Reaching Out”, emphasized new strategies and partnerships necessary to reach the 2020 goal of elimination of lymphatic filariasis (LF) as a public-health problem. PMID:24450283

  2. Physics Reach with a Monochromatic Neutrino Beam from Electron Capture

    CERN Document Server

    Bernabeu, J.; Espinoza, C.; Lindroos, M.

    2005-01-01

    Neutrino oscillation experiments from different sources have demonstrated non-vanishing neutrino masses and flavour mixings. The next experiments have to address the determination of the connecting mixing U(e3) and the existence of the CP violating phase. Whereas U(e3) measures the strength of the oscillation probability in appearance experiments, the CP phase acts as a phase-shift in the interference pattern. Here we propose to separate these two parameters by energy dependence, using the novel idea of a monochromatic neutrino beam facility based on the acceleration of ions that decay fast through electron capture. Fine tuning of the boosted neutrino energy allows precision measurements able to open a window for the discovery of CP violation, even for a mixing as small as 1 degree

  3. Scaling under REACH. Development of a guideline for the evaluation of the safe recommendations for use of chemicals by scaling; Scaling unter REACH. Entwicklung einer Handlungsanleitung zur Bestimmung der sicheren Verwendungsbedingungen von Chemikalien durch Scaling

    Energy Technology Data Exchange (ETDEWEB)

    Bunke, Dirk; Gross, Rita; Vogel, Steffen [Oeko-Institut e.V. - Institut fuer Angewandte Oekologie e.V., Freiburg im Breisgau (Germany)

    2011-11-15

    Scaling in the context of REACH means: use of simple mathematics to check, whether chemi-cals are used in a safe way. Even in case if certain conditions of use deviate from the exposure scenario. In specific cases, scaling offers downstream users the opportunity to demonstrate coverage by an exposure scenario for their individual conditions of use. In this report we describe the duty of downstream users to check their conditions of use. We give a definition of scaling related to REACH. We describe objectives and results of scaling. We characterise available scaling tools in a structured way. We describe options for further development and harmonisation of scaling tools. Under use of the experience with existing tools, we develop a guidance document on scaling. Three examples in this guidance make clear how scaling works. In five steps. The guidance is addressed to persons using substances in industrial or professional applications - downstream users according to REACH. In addition, the guidance supports producers of substances and formulators who want to develop scaling tools for their customers. The report includes a calculation table for scaling related to the environment (REACH Scale Environment). In addition, it includes a template to generate product-specific scaling tools. This report focuses on scaling related to environmental exposure assessment. Scaling is possible related to workers and consumer exposure, too. References for this are given in chapter 7. (orig.)

  4. REACH: an effective catalyst for scaling up priority nutrition interventions at the country level.

    Science.gov (United States)

    Pearson, Brenda L; Ljungqvist, Björn

    2011-06-01

    Renewed Efforts Against Child Hunger (REACH) is the joint United Nations initiative to address Millennium Development Goal (MDG) 10, Target 3, i.e., to halve the proportion of underweight children under 5 years old by 2015. The United Nations Food and Agriculture Organization (FAO), the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), the World Food Programme (WFP), and the International Fund for Agricultural Development (IFAD) developed and tested a facilitation mechanism to act as a catalyst for scaling up multisectoral nutrition activities. The UN-REACH partners developed pilot projects in Mauritania and Lao PDR from 2008 to 2010 and deployed facilitators to improve nutrition governance and coordination. Review missions were conducted in February 2011 to assess the REACH approach and what it achieved. The UN review mission members reviewed documents, assessed policy and management indicators, conducted qualitative interviews, and discussed findings with key stakeholders, including the most senior UN nutrition directors from all agencies. Among other UN-REACH achievements, the Prime Minister of Mauritania agreed to preside over a new National Nutrition Development Council responsible for high-level decision-making and setting national policy objectives. REACH facilitated the completion of Lao's first national Nutrition Strategy and Plan of Action and formation of the multistakeholder Nutrition Task Force. During the REACH engagement, coordination, joint advocacy, situation analysis, policy development, and joint UN programming for nutrition were strengthened in Lao PDR and Mauritania. Improvements in the nutrition governance and management mechanisms in Mauritania and Lao PDR were observed during the period of REACH support through increased awareness of nutrition as a key development objective, establishment of governmental multisectoral coordinating mechanisms, improved government capacity, and new joint UN-government nutrition

  5. Effects of turbulent hyporheic mixing on reach-scale solute transport

    Science.gov (United States)

    Roche, K. R.; Li, A.; Packman, A. I.

    2017-12-01

    Turbulence rapidly mixes solutes and fine particles into coarse-grained streambeds. Both hyporheic exchange rates and spatial variability of hyporheic mixing are known to be controlled by turbulence, but it is unclear how turbulent mixing influences mass transport at the scale of stream reaches. We used a process-based particle-tracking model to simulate local- and reach-scale solute transport for a coarse-bed stream. Two vertical mixing profiles, one with a smooth transition from in-stream to hyporheic transport conditions and a second with enhanced turbulent transport at the sediment-water interface, were fit to steady-state subsurface concentration profiles observed in laboratory experiments. The mixing profile with enhanced interfacial transport better matched the observed concentration profiles and overall mass retention in the streambed. The best-fit mixing profiles were then used to simulate upscaled solute transport in a stream. Enhanced mixing coupled in-stream and hyporheic solute transport, causing solutes exchanged into the shallow subsurface to have travel times similar to the water column. This extended the exponential region of the in-stream solute breakthrough curve, and delayed the onset of the heavy power-law tailing induced by deeper and slower hyporheic porewater velocities. Slopes of observed power-law tails were greater than those predicted from stochastic transport theory, and also changed in time. In addition, rapid hyporheic transport velocities truncated the hyporheic residence time distribution by causing mass to exit the stream reach via subsurface advection, yielding strong exponential tempering in the in-stream breakthrough curves at the timescale of advective hyporheic transport through the reach. These results show that strong turbulent mixing across the sediment-water interface violates the conventional separation of surface and subsurface flows used in current models for solute transport in rivers. Instead, the full distribution of

  6. Hyporheic invertebrate assemblages at reach scale in a Neotropical stream in Brazil.

    Science.gov (United States)

    Mugnai, R; Messana, G; Di Lorenzo, T

    2015-11-01

    In the Neotropical Region, information concerning hyporheic communities is virtually non-existent. We carried out a sampling survey in the hyporheic zone of the Tijuca River, in the Tijuca National Park, located in the urban area of the city of Rio de Janeiro. Biological samples from the hyporheic zone were collected in three different stream reaches, in June 2012. The main objectives were: 1) to describe the structure of invertebrate assemblages in the hyporheic zone of a neotropical stream; 2) to apply a reach-scale approach in order to investigate spatial patterns of the hyporheic assemblages in relation to hydrology, depth and microhabitat typology. A total of 1460 individuals were collected and identified in 31 taxa belonging to Nematoda, Annelida, Crustacea, Hydrachnidia and Insecta. The class Insecta dominated the upper layer of the hyporheic zone. Copepods were the most abundant taxon among crustaceans and occurred mostly in the upwelling areas of the reaches. The results of this study represent one of the few contributions so far about hyporheic invertebrate assemblages of the Neotropical Region.

  7. Simulating stream response to floodplain connectivity, reforestation and wetland restoration from reach to catchment scales

    Science.gov (United States)

    Singh, N.; Bomblies, A.; Wemple, B. C.; Ricketts, T.

    2017-12-01

    Natural infrastructure (e.g., floodplains, forests) can offer multiple ecosystem services (ES), including flood resilience and water quality improvement. In order to maintain these ES, state, federal and non-profit organizations may consider various interventions, such as increased floodplain connectivity, reforestation, and wetland restoration to minimize flood peaks and erosion during events. However, the effect of these interventions on hydro-geomorphic responses of streams from reach to catchment scales (>100 km2) are rarely quantified. We used stream geomorphic assessment datasets with a hydraulic model to investigate the influence of above mentioned interventions on stream power (SP), water depth (WD) and channel velocity (VEL) during floods of 2yr and 100yr return periods for three catchments in the Lake Champlain basin, Vermont. To simulate the effect of forests and wetlands, we changed the Manning's coefficient in the model, and to simulate the increased connectivity of the floodplain, we edited the LIDAR data to lower bank elevations. We find that the wetland scenario resulted in the greatest decline in WD and SP, whereas forested scenario exhibited maximum reduction in VEL. The connectivity scenario showed a decline in almost all stream responses, but the magnitude of change was relatively smaller. On average, 35% (2yr) and 50% (100yr) of altered reaches demonstrated improvement over baseline, and 39% (2yr) and 31% (100yr) of altered reaches showed degradation over baseline, across all interventions. We also noted changes in stream response along unaltered reaches (>30%), where we did not make interventions. Overall, these results point to the complexity related to stream interventions and suggest careful evaluation of spatially explicit tradeoffs of these interventions on river-floodplain ecosystem. The proposed approach of simulating and understanding stream's response to interventions, prior to the implementation of restoration activities, may lead to

  8. Preface: Special Topic on Frontiers in Molecular Scale Electronics

    Science.gov (United States)

    Evers, Ferdinand; Venkataraman, Latha

    2017-03-01

    The electronic, mechanical, and thermoelectric properties of molecular scale devices have fascinated scientists across several disciplines in natural sciences and engineering. The interest is partially technological, driven by the fast miniaturization of integrated circuits that now have reached characteristic features at the nanometer scale. Equally important, a very strong incentive also exists to elucidate the fundamental aspects of structure-function relations for nanoscale devices, which utilize molecular building blocks as functional units. Thus motivated, a rich research field has established itself, broadly termed "Molecular Electronics," that hosts a plethora of activities devoted to this goal in chemistry, physics, and electrical engineering. This Special Topic on Frontiers of Molecular Scale Electronics captures recent theoretical and experimental advances in the field.

  9. Reach-scale stream restoration in agricultural streams of southern Minnesota alters structural and functional responses of macroinvertebrates

    Science.gov (United States)

    Dolph, Christine L.; Eggert, Susan L.; Magner, Joe; Ferrington, Leonard C.; Vondracek, Bruce C.

    2015-01-01

    Recent studies suggest that stream restoration at the reach scale may not increase stream biodiversity, raising concerns about the utility of this conservation practice. We examined whether reach-scale restoration in disturbed agricultural streams was associated with changes in macroinvertebrate community structure (total macroinvertebrate taxon richness, total macroinvertebrate density, Ephemeroptera, Plecoptera, Trichoptera [EPT] taxon richness, % abundance of EPT taxa) or secondary production (macroinvertebrate biomass over time). We collected macroinvertebrate samples over the course of 1 y from restored and unrestored reaches of 3 streams in southern Minnesota and used generalized least-square (GLS) models to assess whether measures of community structure were related to reach type, stream site, or sampling month. After accounting for effects of stream site and time, we found no significant difference in total taxon richness or % abundance of EPT taxa between restored and unrestored reaches. However, the number of EPT taxa and macroinvertebrate density were significantly higher in restored than in unrestored reaches. We compared secondary production estimates among study reaches based on 95th-percentile confidence intervals generated via bootstrapping. In each study stream, secondary production was significantly (2–3×) higher in the restored than in the unrestored reach. Higher productivity in the restored reaches was largely a result of the disproportionate success of a few dominant, tolerant taxa. Our findings suggest that reach-scale restoration may have ecological effects that are not detected by measures of total taxon richness alone.

  10. SENSITIVITY EVALUATION OF THE ELECTRONIC CAR SCALE

    Directory of Open Access Journals (Sweden)

    Tomasz KĄDZIOŁKA

    2014-06-01

    Full Text Available During every day activities related with performed work or homework duties we meet a lot of equipment and we don't realize about their complex construction. This can be different type of equipment making every day work easier, such as food processors, dishwashers, ecologic furnaces, gas stoves or mechanisms, which are intended for protection against rain, which are personal umbrellas or devices ensuring higher safety such as ABS in a car or equipment used for measuring different values such as thermometers, barometers and finally scales. Scales due to performed tasks should be rated to measuring equipment which in metrology for example are used to specify linear and angular dimensions or deviations from nominal dimensions. In this article we present results of electronic scales sensitivity tests. For comparison of test results two electronic scales with different measuring range were analyzed

  11. Large wood influence on stream metabolism at a reach-scale in the Assabet River, Massachusetts

    Science.gov (United States)

    David, G. C. L.; Snyder, N. P.; Rosario, G. M.

    2016-12-01

    Total stream metabolism (TSM) represents the transfer of carbon through a channel by both primary production and respiration, and thus represents the movement of energy through a watershed. Large wood (LW) creates geomorphically complex channels by diverting flows, altering shear stresses on the channel bed and banks, and pool development. The increase in habitat complexity around LW is expected to increase TSM, but this change has not been directly measured. In this study, we measured changes in TSM around a LW jam in a Massachusetts river. Dissolved oxygen (DO) time series data are used to quantify gross primary production (GPP), ecosystem respiration (ER), which equal TSM when summed. Two primary objectives of this study are to (1) assess changes in TSM around LW and (2) compare empirical methods of deriving TSM to Grace et al.'s (2015) BASE model. We hypothesized that LW would increase TSM by providing larger pools, increasing coverage for fish and macroinvertebrates, increasing organic matter accumulation, and providing a place for primary producers to anchor and grow. The Assabet River is a 78 km2 drainage basin in central Massachusetts that provides public water supply to 7 towns. A change in TSM over a reach-scale was assessed using two YSI 6-Series Multiparameter Water Quality sondes over a 140 m long pool-riffle open meadow section. The reach included 6 pools and one LW jam. Every two weeks from July to November 2015, the sondes were moved to different pools. The sondes collected DO, temperature, depth, pH, salinity, light intensity, and turbidity at 15-minute intervals. Velocity (V) and discharge (Q) were measured weekly around the sondes and at established cross sections. Instantaneous V and Q were calculated for each sonde by modeling flows in HEC-RAS. Overall, TSM was heavily influenced by the pool size and indirectly to the LW jam which was associated with the largest pool. The largest error in TSM calculations is related to the empirically

  12. Using a Spectral Method to Evaluate Hyporheic Exchange and its Effect on Reach Scale Nitrate Removal.

    Science.gov (United States)

    Moren, I.; Worman, A. L. E.; Riml, J.

    2017-12-01

    Previous studies have shown that hyporheic exchange processes can be of great importance for the transport, retention and mass removal of nutrients in streams. Specifically, the flow of surface water through the hyporheic zone enhances redox-sensitive reactions such as coupled nitrification-denitrification. This self-cleaning capacity of streams can be utilized in stream restoration projects aiming to improve water quality by reconstructing the geomorphology of the streams. To optimize the effect of restoration actions we need quantitative understanding of the linkage between stream geomorphology, hyporheic exchange processes and the desired water quality targets. Here we propose an analytical, spectral methodology to evaluate how different stream geomorphologies induce hyporheic exchange on a wide range of spatial and temporal scales. Measurements of streambed topographies and surface water profiles from agricultural streams were used to calculate the average hyporheic exchange velocity and residence times and the result was compared with in-stream tracer test. Furthermore, the hyporheic exchange induced by steps in the surface water profile was derived as a comparison of the theoretical capacity of the system. Based on differences in hyporheic exchange, the mass removal of nitrate could be derived for the different geomorphologies. The maximum nitrate mass removal was found to be related to a specific Damkhöler number, which reflects that the mass removal can be either reaction or transport controlled. Therefore, although hyporheic exchange induced by steps in the surface water profile was generally larger than the hyporheic exchange in the observed natural reaches, this would not necessarily lead a larger nitrate mass removal provided that the hyporheic residence times are not long enough to facilitate denitrification processes. The study illustrates the importance to investigate a stream thoroughly before any remediation actions are implemented, specifically

  13. Linking the content to demographic reach of online advertising of electronic nicotine delivery systems.

    Science.gov (United States)

    Timberlake, David S; Nikitin, Dmitriy; Garcia-Cano, Jennifer; Cino, Samantha; Savkina, Margarita; Pechmann, Cornelia

    2017-06-20

    Recent studies have separately examined the content and demographic reach of the advertising of electronic nicotine delivery systems (ENDS). No study to our knowledge has linked the two in investigating whether racial/ethnic groups are differentially exposed to the comparative messages conveyed in online ENDS advertisements. 932 unique ENDS advertisements (6311 total), which were posted on 3435 websites between December, 2009 and October, 2015, were categorized as either comparative or non-comparative with respect to the traditional cigarette. The race/ethnicity of website visitors was obtained from a proprietary source and used in constructing variables for racial/ethnic viewership. The variables for advertising content and website racial/ethnic viewership were then linked yielding a final sample of 551 unique ENDS advertisements (2498 total) on 1206 websites. A two-level hierarchical generalized linear model, used in estimating website racial/ethnic viewership as a predictor of comparative advertising, accounted for the nesting of advertisements (level 1) within 152 ENDS brands (level 2). In contrast to racial/ethnic minorities, a greater proportion of non-Hispanic whites visited websites with ENDS advertisements than the overall proportion of nonHispanic white U.S. Internet users. Yet, it was the advertisements on websites that appealed to Hispanics that had greater odds of comparing ENDS to traditional cigarettes. The lower exposure to ENDS advertising among racial/ethnic minorities versus non-Hispanic whites is consistent with survey data. Yet, the greater odds of comparative advertising of ENDS on websites that appeal to racial/ethnic minorities (ie, Hispanics) could impact the longterm health of minority smokers. This study's findings have important implications for the uptake of ENDS among minority smokers. If the comparative advertising yields greater interest and eventual use of ENDS, then minority smokers could either benefit from smoking cessation

  14. Reach-scale land use drives the stress responses of a resident stream fish.

    Science.gov (United States)

    Blevins, Zachary W; Wahl, David H; Suski, Cory D

    2014-01-01

    Abstract To date, relatively few studies have tried to determine the practicality of using physiological information to help answer complex ecological questions and assist in conservation actions aimed at improving conditions for fish populations. In this study, the physiological stress responses of fish were evaluated in-stream between agricultural and forested stream reaches to determine whether differences in these responses can be used as tools to evaluate conservation actions. Creek chub Semotilus atromaculatus sampled directly from forested and agricultural stream segments did not show differences in a suite of physiological indicators. When given a thermal challenge in the laboratory, creek chub sampled from cooler forested stream reaches had higher cortisol levels and higher metabolic stress responses to thermal challenge than creek chub collected from warmer and more thermally variable agricultural reaches within the same stream. Despite fish from agricultural and forested stream segments having different primary and secondary stress responses, fish were able to maintain homeostasis of other physiological indicators to thermal challenge. These results demonstrate that local habitat conditions within discrete stream reaches may impact the stress responses of resident fish and provide insight into changes in community structure and the ability of tolerant fish species to persist in agricultural areas.

  15. Variability of bed mobility in natural, gravel-bed channels and adjustments to sediment load at local and reach scales

    Science.gov (United States)

    Thomas E. Lisle; Jonathan M. Nelson; John Pitlick; Mary Ann Madej; Brent L. Barkett

    2000-01-01

    Abstract - Local variations in boundary shear stress acting on bed-surface particles control patterns of bed load transport and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and sediment supply through mutual interactions among channel form, local grain size, and local flow dynamics that govern bed mobility...

  16. Noncomparative scaling of aromaticity through electron itinerancy

    International Nuclear Information System (INIS)

    Paul, Satadal; Goswami, Tamal; Misra, Anirban

    2015-01-01

    Aromaticity is a multidimensional concept and not a directly observable. These facts have always stood in the way of developing an appropriate theoretical framework for scaling of aromaticity. In the present work, a quantitative account of aromaticity is developed on the basis of cyclic delocalization of π-electrons, which is the phenomenon leading to unique features of aromatic molecules. The stabilization in molecular energy, caused by delocalization of π-electrons is obtained as a second order perturbation energy for archetypal aromatic systems. The final expression parameterizes the aromatic stabilization energy in terms of atom to atom charge transfer integral, onsite repulsion energy and the population of spin orbitals at each site in the delocalized π-electrons. An appropriate computational platform is framed to compute each and individual parameter in the derived equation. The numerical values of aromatic stabilization energies obtained for various aromatic molecules are found to be in close agreement with available theoretical and experimental reports. Thus the reliable estimate of aromaticity through the proposed formalism renders it as a useful tool for the direct assessment of aromaticity, which has been a long standing problem in chemistry

  17. Scaling electron acceleration in the bubble regime for upcoming lasers

    International Nuclear Information System (INIS)

    Jansen, O.; Tueckmantel, T.; Pukhov, A.

    2014-01-01

    Electron acceleration in the laser-plasma bubble appeared to be the most successful regime of laser wake field acceleration in the last decade. The laser technology became mature enough to generate short and relativistically intense pulses required to reach the bubble regime naturally delivering quasi-monoenergetic bunches of relativistic electrons. The upcoming laser technology projects are promising short pulses with many times more energy than the existing ones. The natural question is how will the bubble regime scale with the available laser energy. We present here a parametric study of laser-plasma acceleration in the bubble regime using full three dimensional particle-in-cell simulations and compare numerical results with the analytical scalings from the relativistic laser-plasma similarity theory. Our simulations and the theory match almost perfectly for spot sizes above R = 2λ and laser amplitudes above a 0 = 4. We also studied the emission of synchrotron radiation by the accelerated electrons. Both classical and a QED model were applied. We found borders, at which theory and simulations stopped matching. With small spot radii (R < 2λ) we almost never observed the formation of a bubble structure or any form of mono-energetic acceleration. Low laser amplitudes lead to higher energies than predicted by the theory

  18. Perspectives for tests of neutrino mass generation at the GeV scale. Experimental reach versus theoretical predictions

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Rasmus W.; Winter, Walter

    2016-11-15

    We discuss the parameter space reach of future experiments searching for heavy neutral leptons (HNLs) at the GeV scale in terms of neutrino mass models with three HNL generations. We focus on two classes of models: Generic assumptions (such as random mass matrices or the Casas-Ibarra parameterization) and flavor symmetry-generated models. We demonstrate that the generic approaches lead to comparable parameter space predictions, which tend to be at least partially within the reach of future experiments. On the other hand, specific flavor symmetry models yield more refined predictions, some of these can be more clearly excluded. We also highlight the importance to measure the flavor-dependent couplings of the HNLs as a model discriminator, and we clarify the impact of assumptions frequently used in the literature to show the parameter space reach for the active-sterile mixings.

  19. Perspectives for tests of neutrino mass generation at the GeV scale. Experimental reach versus theoretical predictions

    International Nuclear Information System (INIS)

    Rasmussen, Rasmus W.; Winter, Walter

    2016-11-01

    We discuss the parameter space reach of future experiments searching for heavy neutral leptons (HNLs) at the GeV scale in terms of neutrino mass models with three HNL generations. We focus on two classes of models: Generic assumptions (such as random mass matrices or the Casas-Ibarra parameterization) and flavor symmetry-generated models. We demonstrate that the generic approaches lead to comparable parameter space predictions, which tend to be at least partially within the reach of future experiments. On the other hand, specific flavor symmetry models yield more refined predictions, some of these can be more clearly excluded. We also highlight the importance to measure the flavor-dependent couplings of the HNLs as a model discriminator, and we clarify the impact of assumptions frequently used in the literature to show the parameter space reach for the active-sterile mixings.

  20. Geomorphic Controls on Floodplain Soil Organic Carbon in the Yukon Flats, Interior Alaska, From Reach to River Basin Scales

    Science.gov (United States)

    Lininger, K. B.; Wohl, E.; Rose, J. R.

    2018-03-01

    Floodplains accumulate and store organic carbon (OC) and release OC to rivers, but studies of floodplain soil OC come from small rivers or small spatial extents on larger rivers in temperate latitudes. Warming climate is causing substantial change in geomorphic process and OC fluxes in high latitude rivers. We investigate geomorphic controls on floodplain soil OC concentrations in active-layer mineral sediment in the Yukon Flats, interior Alaska. We characterize OC along the Yukon River and four tributaries in relation to geomorphic controls at the river basin, segment, and reach scales. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Statistical analyses indicate that OC varies among river basins, among planform types along a river depending on the geomorphic unit, and among geomorphic units. OC decreases with sample depth, suggesting that most OC accumulates via autochthonous inputs from floodplain vegetation. Floodplain and river characteristics, such as grain size, soil moisture, planform, migration rate, and riverine DOC concentrations, likely influence differences among rivers. Grain size, soil moisture, and age of surface likely influence differences among geomorphic units. Mean OC concentrations vary more among geomorphic units (wetlands = 5.1% versus bars = 2.0%) than among study rivers (Dall River = 3.8% versus Teedrinjik River = 2.3%), suggesting that reach-scale geomorphic processes more strongly control the spatial distribution of OC than basin-scale processes. Investigating differences at the basin and reach scale is necessary to accurately assess the amount and distribution of floodplain soil OC, as well as the geomorphic controls on OC.

  1. Scaling of Sediment Dynamics in a Reach-Scale Laboratory Model of a Sand-Bed Stream with Riparian Vegetation

    Science.gov (United States)

    Gorrick, S.; Rodriguez, J. F.

    2011-12-01

    A movable bed physical model was designed in a laboratory flume to simulate both bed and suspended load transport in a mildly sinuous sand-bed stream. Model simulations investigated the impact of different vegetation arrangements along the outer bank to evaluate rehabilitation options. Preserving similitude in the 1:16 laboratory model was very important. In this presentation the scaling approach, as well as the successes and challenges of the strategy are outlined. Firstly a near-bankfull flow event was chosen for laboratory simulation. In nature, bankfull events at the field site deposit new in-channel features but cause only small amounts of bank erosion. Thus the fixed banks in the model were not a drastic simplification. Next, and as in other studies, the flow velocity and turbulence measurements were collected in separate fixed bed experiments. The scaling of flow in these experiments was simply maintained by matching the Froude number and roughness levels. The subsequent movable bed experiments were then conducted under similar hydrodynamic conditions. In nature, the sand-bed stream is fairly typical; in high flows most sediment transport occurs in suspension and migrating dunes cover the bed. To achieve similar dynamics in the model equivalent values of the dimensionless bed shear stress and the particle Reynolds number were important. Close values of the two dimensionless numbers were achieved with lightweight sediments (R=0.3) including coal and apricot pips with a particle size distribution similar to that of the field site. Overall the moveable bed experiments were able to replicate the dominant sediment dynamics present in the stream during a bankfull flow and yielded relevant information for the analysis of the effects of riparian vegetation. There was a potential conflict in the strategy, in that grain roughness was exaggerated with respect to nature. The advantage of this strategy is that although grain roughness is exaggerated, the similarity of

  2. Mechanisms of Cottonwood Establishment in Gravel-Bed Rivers, across Scales from the Bar to the Reach

    Science.gov (United States)

    Meier, C. I.

    2017-12-01

    Riparian cottonwoods are pioneer trees adapted to colonizing fluvial corridors, with strong effects on ecosystem structure and function. As their populations are being affected by flow alterations and invasive species, their recruitment mechanisms need to be understood, to support scientifically-based restoration efforts. I propose new concepts for cottonwood establishment in gravelly streams, from the local to the reach scale. These notions complement the currently-accepted ideas, which apply only to the landscape scale, and whose basic assumptions (existence of an alluvial water table, which is planar, almost horizontal, and linked to the river stage, with a parallel, spatially-uniform capillary fringe) seem to be based on a physical template that is only valid in the case of sand-bed streams. At the local, within-the-bar scale, two concepts drive establishment success. First, a finer matrix material helps retain more capillary water after the yearly snowmelt flood or a precipitation event. Second, the coarse surface layer of clean gravel and cobble acts as rock mulch, strongly decreasing evaporative losses. At the reach scale, we find that the commonly reported arcuate bands of cottonwoods do not depend on groundwater, but are caused by water dispersal (hydrochory). Wind-dispersed seeds fall into the river, are entrained into the drift, and start germinating as they travel under water. Some of the seeds and germinants find their way into the shallow, high relative roughness flow along the cobble shoreline. They are able to deposit in this environment, where they start growing, also under water. As waters recede, during the period of seed availability in the drift, the river seeds its banks and bars. Thus, the boundaries of observed bands and patches with successful seedling recruitment correspond to the location of flow profiles at different dates during the flood recession.

  3. Relationships of sedimentation and benthic macroinvertebrate assemblages in headwater streams using systematic longitudinal sampling at the reach scale.

    Science.gov (United States)

    Longing, S D; Voshell, J R; Dolloff, C A; Roghair, C N

    2010-02-01

    Investigating relationships of benthic invertebrates and sedimentation is challenging because fine sediments act as both natural habitat and potential pollutant at excessive levels. Determining benthic invertebrate sensitivity to sedimentation in forested headwater streams comprised of extreme spatial heterogeneity is even more challenging, especially when associated with a background of historical and intense watershed disturbances that contributed unknown amounts of fine sediments to stream channels. This scenario exists in the Chattahoochee National Forest where such historical timber harvests and contemporary land-uses associated with recreation have potentially affected the biological integrity of headwater streams. In this study, we investigated relationships of sedimentation and the macroinvertebrate assemblages among 14 headwater streams in the forest by assigning 30, 100-m reaches to low, medium, or high sedimentation categories. Only one of 17 assemblage metrics (percent clingers) varied significantly across these categories. This finding has important implications for biological assessments by showing streams impaired physically by sedimentation may not be impaired biologically, at least using traditional approaches. A subsequent multivariate cluster analysis and indicator species analysis were used to further investigate biological patterns independent of sedimentation categories. Evaluating the distribution of sedimentation categories among biological reach clusters showed both within-stream variability in reach-scale sedimentation and sedimentation categories generally variable within clusters, reflecting the overall physical heterogeneity of these headwater environments. Furthermore, relationships of individual sedimentation variables and metrics across the biological cluster groups were weak, suggesting these measures of sedimentation are poor predictors of macroinvertebrate assemblage structure when using a systematic longitudinal sampling design

  4. The linearly scaling 3D fragment method for large scale electronic structure calculations

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Zhengji [National Energy Research Scientific Computing Center (NERSC) (United States); Meza, Juan; Shan Hongzhang; Strohmaier, Erich; Bailey, David; Wang Linwang [Computational Research Division, Lawrence Berkeley National Laboratory (United States); Lee, Byounghak, E-mail: ZZhao@lbl.go [Physics Department, Texas State University (United States)

    2009-07-01

    The linearly scaling three-dimensional fragment (LS3DF) method is an O(N) ab initio electronic structure method for large-scale nano material simulations. It is a divide-and-conquer approach with a novel patching scheme that effectively cancels out the artificial boundary effects, which exist in all divide-and-conquer schemes. This method has made ab initio simulations of thousand-atom nanosystems feasible in a couple of hours, while retaining essentially the same accuracy as the direct calculation methods. The LS3DF method won the 2008 ACM Gordon Bell Prize for algorithm innovation. Our code has reached 442 Tflop/s running on 147,456 processors on the Cray XT5 (Jaguar) at OLCF, and has been run on 163,840 processors on the Blue Gene/P (Intrepid) at ALCF, and has been applied to a system containing 36,000 atoms. In this paper, we will present the recent parallel performance results of this code, and will apply the method to asymmetric CdSe/CdS core/shell nanorods, which have potential applications in electronic devices and solar cells.

  5. Quantifying Hyporheic Exchanges in a Large Scale River Reach Using Coupled 3-D Surface and Subsurface Computational Fluid Dynamics Simulations.

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Glenn Edward; Bao, J; Huang, M; Hou, Z; Perkins, W; Harding, S; Titzler, S; Ren, H; Thorne, P; Suffield, S; Murray, C; Zachara, J

    2017-03-01

    Hyporheic exchange is a critical mechanism shaping hydrological and biogeochemical processes along a river corridor. Recent studies on quantifying the hyporheic exchange were mostly limited to local scales due to field inaccessibility, computational demand, and complexity of geomorphology and subsurface geology. Surface flow conditions and subsurface physical properties are well known factors on modulating the hyporheic exchange, but quantitative understanding of their impacts on the strength and direction of hyporheic exchanges at reach scales is absent. In this study, a high resolution computational fluid dynamics (CFD) model that couples surface and subsurface flow and transport is employed to simulate hyporheic exchanges in a 7-km long reach along the main-stem of the Columbia River. Assuming that the hyporheic exchange does not affect surface water flow conditions due to its negligible magnitude compared to the volume and velocity of river water, we developed a one-way coupled surface and subsurface water flow model using the commercial CFD software STAR-CCM+. The model integrates the Reynolds-averaged Navier-Stokes (RANS) equation solver with a realizable κ-ε two-layer turbulence model, a two-layer all y+ wall treatment, and the volume of fluid (VOF) method, and is used to simulate hyporheic exchanges by tracking the free water-air interface as well as flow in the river and the subsurface porous media. The model is validated against measurements from acoustic Doppler current profiler (ADCP) in the stream water and hyporheic fluxes derived from a set of temperature profilers installed across the riverbed. The validated model is then employed to systematically investigate how hyporheic exchanges are influenced by surface water fluid dynamics strongly regulated by upstream dam operations, as well as subsurface structures (e.g. thickness of riverbed and subsurface formation layers) and hydrogeological properties (e.g. permeability). The results

  6. Rating of Everyday Arm-Use in the Community and Home (REACH scale for capturing affected arm-use after stroke: development, reliability, and validity.

    Directory of Open Access Journals (Sweden)

    Lisa A Simpson

    Full Text Available To develop a brief, valid and reliable tool [the Rating of Everyday Arm-use in the Community and Home (REACH scale] to classify affected upper limb use after stroke outside the clinical setting.Focus groups with clinicians, patients and caregivers (n = 33 and a literature review were employed to develop the REACH scale. A sample of community-dwelling individuals with stroke was used to assess the validity (n = 96 and inter-rater reliability (n = 73 of the new scale.The REACH consists of separate scales for dominant and non-dominant affected upper limbs, and takes five minutes to administer. Each scale consists of six categories that capture 'no use' to 'full use'. The intraclass correlation coefficient and weighted kappa for inter-rater reliability were 0.97 (95% confidence interval: 0.95-0.98 and 0.91 (0.89-0.93 respectively. REACH scores correlated with external measures of upper extremity use, function and impairment (rho = 0.64-0.94.The REACH scale is a reliable, quick-to-administer tool that has strong relationships to other measures of upper limb use, function and impairment. By providing a rich description of how the affected upper limb is used outside of the clinical setting, the REACH scale fills an important gap among current measures of upper limb use and is useful for understanding the long term effects of stroke rehabilitation.

  7. Graph-based linear scaling electronic structure theory

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Anders M. N., E-mail: amn@lanl.gov; Negre, Christian F. A.; Cawkwell, Marc J.; Swart, Pieter J.; Germann, Timothy C.; Bock, Nicolas [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mniszewski, Susan M.; Mohd-Yusof, Jamal; Wall, Michael E.; Djidjev, Hristo [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rubensson, Emanuel H. [Division of Scientific Computing, Department of Information Technology, Uppsala University, Box 337, SE-751 05 Uppsala (Sweden)

    2016-06-21

    We show how graph theory can be combined with quantum theory to calculate the electronic structure of large complex systems. The graph formalism is general and applicable to a broad range of electronic structure methods and materials, including challenging systems such as biomolecules. The methodology combines well-controlled accuracy, low computational cost, and natural low-communication parallelism. This combination addresses substantial shortcomings of linear scaling electronic structure theory, in particular with respect to quantum-based molecular dynamics simulations.

  8. Impacts of Vegetation Growth on Reach-scale Flood Hydraulics in a Sand-bed River and the Implications for Vegetation-morphology Coevolution

    Science.gov (United States)

    Box, S.; Wilcox, A. C.

    2017-12-01

    Vegetation alters flood hydraulics and geomorphic response, yet quantifying and predicting such responses across spatial and temporal scales remains challenging. Plant- and patch-scale studies consistently show that vegetation increases local hydraulic variability, yet reach-scale hydrodynamic models often assume vegetation has a spatially homogeneous effect on hydraulics. Using Nays2DH in iRIC (International River Interface Cooperative), we model the effect of spatially heterogeneous vegetation on a series of floods with varying antecedent vegetation conditions in a sand-bed river in western Arizona, taking advantage of over a decade of data on a system that experienced substantial geomorphic, hydrologic, and ecosystem changes. We show that pioneer woody seedlings (Tamarix, Populus, Salix) and cattail (Typha) increase local hydraulic variability, including velocity and bed shear stress, along individual cross sections, predominantly by decreasing velocity in zones of vegetation establishment and growth and increasing velocity in unvegetated areas, with analogous effects on shear stress. This was especially prominent in a study reach where vegetation growth contributed to thalweg incision relative to a vegetated bar. Evaluation of these results in the context of observed geomorphic response to floods elucidates mechanisms by which vegetation and channel morphology coevolve at a reach scale. By quantifying the influence of spatially heterogeneous vegetation on reach-scale hydraulics, we demonstrate that plant- and patch-scale research on vegetation hydraulics is applicable to ecogeomorphology at the reach scale.

  9. Electron Heating at Kinetic Scales in Magnetosheath Turbulence

    International Nuclear Information System (INIS)

    Chasapis, Alexandros; Matthaeus, W. H.; Parashar, T. N.; LeContel, O.; Retinò, A.; Breuillard, H.; Khotyaintsev, Y.; Vaivads, A.; Eriksson, E.; Lavraud, B.; Moore, T. E.; Burch, J. L.; Torbert, R. B.; Chutter, M.; Needell, J.; Lindqvist, P.-A.; Marklund, G.; Ergun, R. E.; Goodrich, K. A.; Wilder, F. D.

    2017-01-01

    We present a statistical study of coherent structures at kinetic scales, using data from the Magnetospheric Multiscale mission in the Earth’s magnetosheath. We implemented the multi-spacecraft partial variance of increments (PVI) technique to detect these structures, which are associated with intermittency at kinetic scales. We examine the properties of the electron heating occurring within such structures. We find that, statistically, structures with a high PVI index are regions of significant electron heating. We also focus on one such structure, a current sheet, which shows some signatures consistent with magnetic reconnection. Strong parallel electron heating coincides with whistler emissions at the edges of the current sheet.

  10. REACH-ER: a tool to evaluate river basin remediation measures for contaminants at the catchment scale

    Science.gov (United States)

    van Griensven, Ann; Haest, Pieter Jan; Broekx, Steven; Seuntjens, Piet; Campling, Paul; Ducos, Geraldine; Blaha, Ludek; Slobodnik, Jaroslav

    2010-05-01

    The European Union (EU) adopted the Water Framework Directive (WFD) in 2000 ensuring that all aquatic ecosystems meet ‘good status' by 2015. However, it is a major challenge for river basin managers to meet this requirement in river basins with a high population density as well as intensive agricultural and industrial activities. The EU financed AQUAREHAB project (FP7) specifically examines the ecological and economic impact of innovative rehabilitation technologies for multi-pressured degraded water bodies. For this purpose, a generic collaborative management tool ‘REACH-ER' is being developed that can be used by stakeholders, citizens and water managers to evaluate the ecological and economical effects of different remedial actions on waterbodies. The tool is built using databases from large scale models simulating the hydrological dynamics of the river basing and sub-basins, the costs of the measures and the effectiveness of the measures in terms of ecological impact. Knowledge rules are used to describe the relationships between these data in order to compute the flux concentrations or to compute the effectiveness of measures. The management tool specifically addresses nitrate pollution and pollution by organic micropollutants. Detailed models are also used to predict the effectiveness of site remedial technologies using readily available global data. Rules describing ecological impacts are derived from ecotoxicological data for (mixtures of) specific contaminants (msPAF) and ecological indices relating effects to the presence of certain contaminants. Rules describing the cost-effectiveness of measures are derived from linear programming models identifying the least-cost combination of abatement measures to satisfy multi-pollutant reduction targets and from multi-criteria analysis.

  11. Theory of Correlated Pairs of Electrons Oscillating in Resonant Quantum States to Reach the Critical Temperature in a Metal

    OpenAIRE

    Aroche, Raúl Riera; Rosas-Cabrera, Rodrigo Arturo; Burgos, Rodrigo Arturo Rosas; Betancourt-Riera, René; Betancourt-Riera, Ricardo

    2017-01-01

    The formation of Correlated Electron Pairs Oscillating around the Fermi level in Resonant Quantum States (CEPO-RQS), when a metal is cooled to its critical temperature T=Tc, is studied. The necessary conditions for the existence of CEPO-RQS are analyzed. The participation of electron-electron interaction screened by an electron dielectric constant of the form proposed by Thomas Fermi is considered and a physical meaning for the electron-phonon-electron interaction in the formation of the CEPO...

  12. Scaling of ion implanted Si:P single electron devices

    International Nuclear Information System (INIS)

    Escott, C C; Hudson, F E; Chan, V C; Petersson, K D; Clark, R G; Dzurak, A S

    2007-01-01

    We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n + ) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number

  13. Scaling of ion implanted Si:P single electron devices

    Energy Technology Data Exchange (ETDEWEB)

    Escott, C C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Hudson, F E [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Chan, V C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Petersson, K D [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Clark, R G [Centre for Quantum Computer Technology, School of Physics, UNSW, Sydney, 2052 (Australia); Dzurak, A S [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia)

    2007-06-13

    We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n{sup +}) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number.

  14. On Electron-Scale Whistler Turbulence in the Solar Wind

    Science.gov (United States)

    Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.

    2016-01-01

    For the first time, the dispersion relation for turbulence magnetic field fluctuations in the solar wind is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale solar wind turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.

  15. Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Ruiz, J.; White, A. E. [MIT-Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Ren, Y.; Guttenfelder, W.; Kaye, S. M.; Leblanc, B. P.; Mazzucato, E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-12-15

    Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, k{sub ⊥}ρ{sub e} ≲ 1, can be responsible for anomalous electron thermal transport in NSTX. Electron scale (high-k) turbulence is diagnosed in NSTX with a high-k microwave scattering system [D. R. Smith et al., Rev. Sci. Instrum. 79, 123501 (2008)]. Here we report on stabilization effects of the electron density gradient on electron-scale density fluctuations in a set of neutral beam injection heated H-mode plasmas. We found that the absence of high-k density fluctuations from measurements is correlated with large equilibrium density gradient, which is shown to be consistent with linear stabilization of ETG modes due to the density gradient using the analytical ETG linear threshold in F. Jenko et al. [Phys. Plasmas 8, 4096 (2001)] and linear gyrokinetic simulations with GS2 [M. Kotschenreuther et al., Comput. Phys. Commun. 88, 128 (1995)]. We also found that the observed power of electron-scale turbulence (when it exists) is anti-correlated with the equilibrium density gradient, suggesting density gradient as a nonlinear stabilizing mechanism. Higher density gradients give rise to lower values of the plasma frame frequency, calculated based on the Doppler shift of the measured density fluctuations. Linear gyrokinetic simulations show that higher values of the electron density gradient reduce the value of the real frequency, in agreement with experimental observation. Nonlinear electron-scale gyrokinetic simulations show that high electron density gradient reduces electron heat flux and stiffness, and increases the ETG nonlinear threshold, consistent with experimental observations.

  16. Scaling laws in high energy electron-nuclear processes

    International Nuclear Information System (INIS)

    Chemtob, M.

    1980-11-01

    We survey the parton model description of high momentum transfer electron scattering processes with nuclei. We discuss both nucleon and quark parton models and confront the patterns of scaling laws violations, induced by binding effects, in the former, and perturbative QCD effects, in the latter

  17. Electron drift in a large scale solid xenon

    International Nuclear Information System (INIS)

    Yoo, J.; Jaskierny, W.F.

    2015-01-01

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Therefore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon

  18. Molecular-Scale Electronics: From Concept to Function.

    Science.gov (United States)

    Xiang, Dong; Wang, Xiaolong; Jia, Chuancheng; Lee, Takhee; Guo, Xuefeng

    2016-04-13

    Creating functional electrical circuits using individual or ensemble molecules, often termed as "molecular-scale electronics", not only meets the increasing technical demands of the miniaturization of traditional Si-based electronic devices, but also provides an ideal window of exploring the intrinsic properties of materials at the molecular level. This Review covers the major advances with the most general applicability and emphasizes new insights into the development of efficient platform methodologies for building reliable molecular electronic devices with desired functionalities through the combination of programmed bottom-up self-assembly and sophisticated top-down device fabrication. First, we summarize a number of different approaches of forming molecular-scale junctions and discuss various experimental techniques for examining these nanoscale circuits in details. We then give a full introduction of characterization techniques and theoretical simulations for molecular electronics. Third, we highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits. Finally, we provide a critical discussion of limitations and main challenges that still exist for the development of molecular electronics. These analyses should be valuable for deeply understanding charge transport through molecular junctions, the device fabrication process, and the roadmap for future practical molecular electronics.

  19. The validity of the density scaling method in primary electron transport for photon and electron beams

    International Nuclear Information System (INIS)

    Woo, M.K.; Cunningham, J.R.

    1990-01-01

    In the convolution/superposition method of photon beam dose calculations, inhomogeneities are usually handled by using some form of scaling involving the relative electron densities of the inhomogeneities. In this paper the accuracy of density scaling as applied to primary electrons generated in photon interactions is examined. Monte Carlo calculations are compared with density scaling calculations for air and cork slab inhomogeneities. For individual primary photon kernels as well as for photon interactions restricted to a thin layer, the results can differ significantly, by up to 50%, between the two calculations. However, for realistic photon beams where interactions occur throughout the whole irradiated volume, the discrepancies are much less severe. The discrepancies for the kernel calculation are attributed to the scattering characteristics of the electrons and the consequent oversimplified modeling used in the density scaling method. A technique called the kernel integration technique is developed to analyze the general effects of air and cork inhomogeneities. It is shown that the discrepancies become significant only under rather extreme conditions, such as immediately beyond the surface after a large air gap. In electron beams all the primary electrons originate from the surface of the phantom and the errors caused by simple density scaling can be much more significant. Various aspects relating to the accuracy of density scaling for air and cork slab inhomogeneities are discussed

  20. Regimes of radiative and nonradiative transitions in transport through an electronic system in a photon cavity reaching a steady state

    Science.gov (United States)

    Gudmundsson, Vidar; Jonsson, Thorsteinn H.; Bernodusson, Maria Laura; Abdullah, Nzar Rauf; Sitek, Anna; Goan, Hsi-Sheng; Tang, Chi-Shung; Manolescu, Andrei

    2017-01-01

    We analyze how a multilevel many-electron system in a photon cavity approaches the steady state when coupled to external leads. When a plunger gate is used to lower cavity photon dressed one- and two-electron states below the bias window defined by the external leads, we can identify one regime with nonradiative transitions dominating the electron transport, and another regime with radiative transitions. Both transitions trap the electrons in the states below the bias bringing the system into a steady state. The order of the two regimes and their relative strength depends on the location of the bias window in the energy spectrum of the system and the initial conditions.

  1. New patterning paradigm? : selective deposition may be the way forward to the far reaches of device scaling after 7nm.

    NARCIS (Netherlands)

    Lapedus, M.; Kessels, W.M.M.

    2015-01-01

    The Eindhoven University of Technology, for one, is working on another approach—direct-write ALD. This is based on an area-selective ALD by an area-activation technique. This makes use of electron-beam induced deposition (EBID) or ion-beam induced deposition (IBID). "We combine the advantages of

  2. Private sector, for-profit health providers in low and middle income countries: can they reach the poor at scale?

    Science.gov (United States)

    Tung, Elizabeth; Bennett, Sara

    2014-06-24

    The bottom of the pyramid concept suggests that profit can be made in providing goods and services to poor people, when high volume is combined with low margins. To-date there has been very limited empirical evidence from the health sector concerning the scope and potential for such bottom of the pyramid models. This paper analyzes private for-profit (PFP) providers currently offering services to the poor on a large scale, and assesses the future prospects of bottom of the pyramid models in health. We searched published and grey literature and databases to identify PFP companies that provided more than 40,000 outpatient visits per year, or who covered 15% or more of a particular type of service in their country. For each included provider, we searched for additional information on location, target market, business model and performance, including quality of care. Only 10 large scale PFP providers were identified. The majority of these were in South Asia and most provided specialized services such as eye care. The characteristics of the business models of these firms were found to be similar to non-profit providers studied by other analysts (such as Bhattacharya 2010). They pursued social rather than traditional marketing, partnerships with government, low cost/high volume services and cross-subsidization between different market segments. There was a lack of reliable data concerning these providers. There is very limited evidence to support the notion that large scale bottom of the pyramid models in health offer good prospects for extending services to the poor in the future. In order to be successful PFP providers often require partnerships with government or support from social health insurance schemes. Nonetheless, more reliable and independent data on such schemes is needed.

  3. Heart rate detection from an electronic weighing scale

    International Nuclear Information System (INIS)

    González-Landaeta, R; Casas, O; Pallàs-Areny, R

    2008-01-01

    We propose a novel technique for beat-to-beat heart rate detection based on the ballistocardiographic (BCG) force signal from a subject standing on a common electronic weighing scale. The detection relies on sensing force variations related to the blood acceleration in the aorta, works even if wearing footwear and does not require any sensors attached to the body because it uses the load cells in the scale. We have devised an approach to estimate the sensitivity and frequency response of three commercial weighing scales to assess their capability to detect the BCG force signal. Static sensitivities ranged from 490 nV V −1 N −1 to 1670 nV V −1 N −1 . The frequency response depended on the subject's mass but it was broad enough for heart rate estimation. We have designed an electronic pulse detection system based on off-the-shelf integrated circuits to sense heart-beat-related force variations of about 0.24 N. The signal-to-noise ratio of the main peaks of the force signal detected was higher than 30 dB. A Bland–Altman plot was used to compare the RR time intervals estimated from the ECG and BCG force signals for 17 volunteers. The error was ±21 ms, which makes the proposed technique suitable for short-term monitoring of the heart rate

  4. Centimetre-scale electron diffusion in photoactive organic heterostructures

    Science.gov (United States)

    Burlingame, Quinn; Coburn, Caleb; Che, Xiaozhou; Panda, Anurag; Qu, Yue; Forrest, Stephen R.

    2018-02-01

    The unique properties of organic semiconductors, such as flexibility and lightness, are increasingly important for information displays, lighting and energy generation. But organics suffer from both static and dynamic disorder, and this can lead to variable-range carrier hopping, which results in notoriously poor electrical properties, with low electron and hole mobilities and correspondingly short charge-diffusion lengths of less than a micrometre. Here we demonstrate a photoactive (light-responsive) organic heterostructure comprising a thin fullerene channel sandwiched between an electron-blocking layer and a blended donor:C70 fullerene heterojunction that generates charges by dissociating excitons. Centimetre-scale diffusion of electrons is observed in the fullerene channel, and this can be fitted with a simple electron diffusion model. Our experiments enable the direct measurement of charge diffusivity in organic semiconductors, which is as high as 0.83 ± 0.07 square centimetres per second in a C60 channel at room temperature. The high diffusivity of the fullerene combined with the extraordinarily long charge-recombination time yields diffusion lengths of more than 3.5 centimetres, orders of magnitude larger than expected for an organic system.

  5. Large scale oil lease automation and electronic custody transfer

    International Nuclear Information System (INIS)

    Price, C.R.; Elmer, D.C.

    1995-01-01

    Typically, oil field production operations have only been automated at fields with long term production profiles and enhanced recovery. The automation generally consists of monitoring and control at the wellhead and centralized facilities. However, Union Pacific Resources Co. (UPRC) has successfully implemented a large scale automation program for rapid-decline primary recovery Austin Chalk wells where purchasers buy and transport oil from each individual wellsite. This project has resulted in two significant benefits. First, operators are using the system to re-engineer their work processes. Second, an inter-company team created a new electronic custody transfer method. This paper will describe: the progression of the company's automation objectives in the area; the field operator's interaction with the system, and the related benefits; the research and development of the new electronic custody transfer method

  6. Scaling of electron beam sources for laser fusion applications

    International Nuclear Information System (INIS)

    Schlitt, L.G.; Bradley, L.P.

    1975-01-01

    The purpose of this study is to develop a scheme for constructing electron beam machines capable of pumping large volumes of gas, to analyze their performance within the framework of existing knowledge of the physical mechanisms involved, to use this analysis to assess the viability of the overall concept, pinpoint weaknesses in the understanding of the physics, identify the most important limiting physical processes, and hence to propose a program to prepare for the eventual construction of a large scale gas laser system. (auth)

  7. A statistical forecast model using the time-scale decomposition technique to predict rainfall during flood period over the middle and lower reaches of the Yangtze River Valley

    Science.gov (United States)

    Hu, Yijia; Zhong, Zhong; Zhu, Yimin; Ha, Yao

    2018-04-01

    In this paper, a statistical forecast model using the time-scale decomposition method is established to do the seasonal prediction of the rainfall during flood period (FPR) over the middle and lower reaches of the Yangtze River Valley (MLYRV). This method decomposites the rainfall over the MLYRV into three time-scale components, namely, the interannual component with the period less than 8 years, the interdecadal component with the period from 8 to 30 years, and the interdecadal component with the period larger than 30 years. Then, the predictors are selected for the three time-scale components of FPR through the correlation analysis. At last, a statistical forecast model is established using the multiple linear regression technique to predict the three time-scale components of the FPR, respectively. The results show that this forecast model can capture the interannual and interdecadal variation of FPR. The hindcast of FPR during 14 years from 2001 to 2014 shows that the FPR can be predicted successfully in 11 out of the 14 years. This forecast model performs better than the model using traditional scheme without time-scale decomposition. Therefore, the statistical forecast model using the time-scale decomposition technique has good skills and application value in the operational prediction of FPR over the MLYRV.

  8. From bottles to stream reaches and networks: Consequences of scale in how we interpret the function of freshwaters in the carbon cycle

    Science.gov (United States)

    Hotchkiss, E. R.

    2017-12-01

    Freshwater biological processes can alter the quantity and quality of organic carbon (OC) inputs from land before they are transported downstream, but the relative role of hydrologic transport and in-stream processing is still not well quantified at the scale of fluvial networks. Despite much research on the role of biology and hydrology in governing the form and fate of C in inland waters, conclusions about the function of freshwater ecosystems in modifying OC still largely depend on where we draw our ecosystem boundaries, i.e., the spatial scale of measurements used to assess OC transformations. Here I review freshwater OC uptake rates derived from bioassay incubations, synoptic modeling, reach-scale experiments, and ecosystem OC spiraling estimates. Median OC uptake velocities from standard bioassay incubations (0.02 m/d) and synoptic modeling (0.04 m/d) are 1-2 orders of magnitude lower than reach-scale experimental DOC additions and ecosystem OC spiraling estimates (2.2 and 0.27 m/d, respectively) in streams and rivers. Together, ecosystem metabolism and OC fluxes can be used to estimate the distance OC travels before being consumed and respired as CO2 through biological processes (i.e., OC spiraling), allowing for a more mechanistic understanding of the role of ecosystem processes and hydrologic fluxes in modifying downstream OC transport. Beyond the reach scale, data from stream network and stream-lake-river modeling simulations show how we may use linked sampling sites within networks to better understand the integrated sources and fate of OC in freshwaters. We currently underestimate the role of upstream processes in contributing to downstream fluxes: moving from single-ecosystem comparisons to linked-ecosystem simulations increases the contribution of in situ OC processing to CO2 emissions from 30% to >40%. Insights from literature reviews, ecosystem process measurements, and model simulations provide a framework for future considerations of integrated C

  9. Direct and indirect effects of multiple stressors on stream invertebrates across watershed, reach and site scales: A structural equation modelling better informing on hydromorphological impacts.

    Science.gov (United States)

    Villeneuve, B; Piffady, J; Valette, L; Souchon, Y; Usseglio-Polatera, P

    2018-01-15

    The purpose of our approach was to take into account the nested spatial scales driving stream functioning in the description of pressures/ecological status links by analysing the results of a hierarchical model. The development of this model has allowed us to answer the following questions: Does the consideration of the indirect links between anthropogenic pressures and stream ecological status modify the hierarchy of pressure types impacting benthic invertebrates? Do the different nested scales play different roles in the anthropogenic pressures/ecological status relationship? Does this model lead to better understanding of the specific role of hydromorphology in the evaluation of stream ecological status? To achieve that goal, we used the Partial Least Square (PLS) path modelling method to develop a structural model linking variables describing (i) land use and hydromorphological alterations at the watershed scale, (ii) hydromorphological alterations at the reach scale, (iii) nutrients-organic matter contamination levels at the site scale, and (iv) substrate characteristics at the sampling site scale, to explain variation in values of a macroinvertebrate-based multimetric index: the French I 2 M 2 . We have highlighted the importance of land use effects exerted on both hydromorphological and chemical characteristics of streams observed at finer scales and their subsequent indirect impact on stream ecological status. Hydromorphological alterations have an effect on the substrate mosaic structure and on the concentrations of nutrients and organic matter at site scale. This result implies that stream hydromorphology can have a major indirect effect on macroinvertebrate assemblages and that the hierarchy of impacts of anthropogenic pressures on stream ecological status generally described in the literature - often determining strategic restoration priorities - has to be re-examined. Finally, the effects of nutrients and organic matter on macroinvertebrate assemblages

  10. Polyelectrolytes processing at pilot scale level by electron beam irradiation

    International Nuclear Information System (INIS)

    Martin, D.; Cirstea, E.; Craciun, G.; Ighigeanu, D.; Marin, Gheorghe G.

    2002-01-01

    Three years of research, combined with engineering activities, have culminated in the development of a new method of electron beam processing applicable up to the pilot scale level, namely, the polyelectrolytes (acrylamide - acrylic acid copolymers) electron beam processing. This new radiation processing method has been achieved by bilateral co-operation between the National Institute for Laser, Plasma and Radiation Physics (NILPRP) and the Electrical Design and Research Institute, EDRI - Bucharest. The polyelectrolytes electron beam (EB) processing was put in operation at EDRI, where, recently, an industrial electron accelerator of 2 MeV and 20 kW, manufactured by Institute of Nuclear Physics, Novosibirsk, Russia was installed in a specially designed irradiation facility. Automatic start-up via computer control makes it compatible with industrial processing. According to the first conclusions, which resulted from our experimental research with regard to acrylamide - acrylic acid copolymers production by EB irradiation, the proper physical and chemical characteristics can be well controlled by chemical composition to be treated and by suitable adjustment of absorbed dose and absorbed dose rate. So, it was possible to obtain a very large area of characteristics and therefore a large area of applications. The conversion coefficient is very high (> 98%) and concentration of the residual monomer is under 0.05%. The tests applied to some wastewaters from the vegetable oil plants demonstrated that the fatty substances, matters in suspension, chemical oxygen demand and biological oxygen demand over 5 days were much reduced, in comparison with classical treatment. Also, sedimentation time was around four times smaller and sediment volume was 60% smaller than the values obtained in case of classical treatment. The necessary EB absorbed dose for the acrylamide - acrylic acid aqueous solution polymerization, established by optimization of chemical composition and irradiation

  11. Scaled electron experiments at the University of Maryland

    International Nuclear Information System (INIS)

    Haber, I.; Bai, G.; Bernal, S.; Beaudoin, B.; Feldman, D.; Fiorito, R.B.; Godlove, T.F.; Kishek, R.A.; O'Shea, P.G.; Quinn, B.; Papadopoulos, C.; Reiser, M.; Rodgers, J.; Stratakis, D.; Sutter, D.; Thangaraj, J.C.T.; Tian, K.; Walter, M.; Wu, C.

    2007-01-01

    The University of Maryland Electron Ring (UMER) and the Long Solenoid Experiment (LSE) are two electron machines that were designed explicitly to study the physics of space-charge-dominated beams. The operating parameters of these machines can be varied by choice of apertures and gun operating conditions to access a wide range of parameters that reproduce, on a scaled basis, the full nonlinear time-dependent physics that is expected in much costlier ion systems. Early operation of these machines has demonstrated the importance of the details of beam initial conditions in determining the downstream evolution. These machines have also been a convenient tested for benchmarking simulation codes such as WARP, and for development of several novel diagnostic techniques. We present our recent experience with multi-turn operation as well as recent longitudinal and transverse physics experiments and comparisons to simulation results. Development of novel diagnostic techniques such as time-dependent imaging using optical transition radiation and tomographic beam reconstruction are also described

  12. Reaching the hard to reach.

    Science.gov (United States)

    Bhiwandi, P; Campbell, M; Potts, M

    1994-01-01

    The 1994 International Conference on Population and Development proposed increasing contraceptive couple protection from 550 million in 1995 to 880 million in 2015. The task for family planning (FP) programs is to provide access to services for, sometimes, inaccessible rural populations. FP need based on desire for no more children has ranged from under 20% in Senegal to almost 80% in Peru. Socioeconomic development was found not to be a prerequisite for fertility change. Gender inequalities in education and social autonomy must be changed. FP access is very important among women with a disadvantaged background or among women unsure about FP. Bangladesh is a good example of a country with increased contraceptive prevalence despite low income. The rule of thumb is that contraception increases of 15% contribute to a drop in family size of about one child. Program effectiveness is related to a variety of factors: contraceptive availability at many locations, acceptable price of contraception, delivery of the oral contraceptives without prescriptions, and other strategies. FP is a service not a medical treatment. A range of methods must be promoted and available from a range of facilities. Contraceptive use is dependent on the woman's stage in her lifecycle and is dependent on informed choice. Community-based distribution systems are effective, whereas free distribution by poorly-trained field workers is not always very effective because patient payment of all or part of the cost assures quality and freedom of choice. Effective programs for underprivileged groups involve aggressive, easy to manage programs that can be replicated rapidly. FP serves a useful function in depressing maternal mortality among the poor in Africa, who have no access to quality health services. Social marketing is an effective strategy for reaching remote areas. Political will and robust management are necessary commodities.

  13. Scale up and application of equal-channel angular extrusion for the electronics and aerospace industries

    International Nuclear Information System (INIS)

    Ferrasse, Stephane; Segal, V.M.; Alford, Frank; Kardokus, Janine; Strothers, Susan

    2008-01-01

    Two areas are critical to promote equal-channel angular extrusion beyond the stage of a laboratory curiosity: (i) tool/processing design and scale up; (ii) development of new submicrometer-grained products. Both goals are pursued at Honeywell. The first case is the successful commercialization of ECAE for the production of sputtering targets from single phase alloys in the electronic industry. Blank dimensions are significantly larger than those reported in the literature. Other described applications are targeted to the increase of tensile strength, high-cycle fatigue and toughness in medium-to-heavily alloyed Al materials used in aerospace. In these alloys, the optimal properties can be reached with better understanding of the interplay between plastic deformation and precipitation mechanisms

  14. Atomic-scale Ge diffusion in strained Si revealed by quantitative scanning transmission electron microscopy

    Science.gov (United States)

    Radtke, G.; Favre, L.; Couillard, M.; Amiard, G.; Berbezier, I.; Botton, G. A.

    2013-05-01

    Aberration-corrected scanning transmission electron microscopy is employed to investigate the local chemistry in the vicinity of a Si0.8Ge0.2/Si interface grown by molecular-beam epitaxy. Atomic-resolution high-angle annular dark field contrast reveals the presence of a nonuniform diffusion of Ge from the substrate into the strained Si thin film. On the basis of multislice calculations, a model is proposed to quantify the experimental contrast, showing that the Ge concentration in the thin film reaches about 4% at the interface and decreases monotonically on a typical length scale of 10 nm. Diffusion occurring during the growth process itself therefore appears as a major factor limiting the abruptness of interfaces in the Si-Ge system.

  15. Reaching Out

    Science.gov (United States)

    Moore, John W.

    1999-11-01

    , television programs, museums, theme parks, Web sites, and many other venues that include science. However, I always have a twinge of disappointment when I look at the shelves in our local bookstore and find that there are far more titles in other sciences than in chemistry. Are other sciences inherently more interestingor their practitioners inherently more literate? I think not. Popularizing chemistry is more dependent on human interaction than is popularizing many other sciences. People deal with devices that approximate Newtonian physics every day. The stars, moon, and planets are there every night, and their vast number and regular motions inspire awe. Living systems are familiar to everyone, and we can observe their behavior and classify them. But chemistry is often hidden or complicated. Cooking food changes the food chemically, but both initial and final versions, like most other substances we encounter daily, are complicated mixtures. Chemists' atomic-scale models are not accessible to our senses. In order for chemistry not to be magic, someone needs to select simple, interesting, relevant examples, demonstrate them or help the average person work with them, and then relate those examples to everyday life. Participating in and supporting National Chemistry Week and other outreach programs is crucial to the health of our discipline. Without chemists who donate their time and expertise to helping people understand and become familiar with chemistry, our fascinating subject is likely to seem dullor even scary. During National Chemistry Week, and during every other week of the year, we should extend hearty thanks to the myriad chemists and teachers whose time, energy, and expertise contribute to helping the public recognize how important and interesting chemistry is.

  16. Auxiliary basis expansions for large-scale electronic structure calculations.

    Science.gov (United States)

    Jung, Yousung; Sodt, Alex; Gill, Peter M W; Head-Gordon, Martin

    2005-05-10

    One way to reduce the computational cost of electronic structure calculations is to use auxiliary basis expansions to approximate four-center integrals in terms of two- and three-center integrals, usually by using the variationally optimum Coulomb metric to determine the expansion coefficients. However, the long-range decay behavior of the auxiliary basis expansion coefficients has not been characterized. We find that this decay can be surprisingly slow. Numerical experiments on linear alkanes and a toy model both show that the decay can be as slow as 1/r in the distance between the auxiliary function and the fitted charge distribution. The Coulomb metric fitting equations also involve divergent matrix elements for extended systems treated with periodic boundary conditions. An attenuated Coulomb metric that is short-range can eliminate these oddities without substantially degrading calculated relative energies. The sparsity of the fit coefficients is assessed on simple hydrocarbon molecules and shows quite early onset of linear growth in the number of significant coefficients with system size using the attenuated Coulomb metric. Hence it is possible to design linear scaling auxiliary basis methods without additional approximations to treat large systems.

  17. Harnessing Social Networks along with Consumer-Driven Electronic Communication Technologies to Identify and Engage Members of 'Hard-to-Reach' Populations: A Methodological Case Report

    Directory of Open Access Journals (Sweden)

    Rock Melanie J

    2010-01-01

    Full Text Available Abstract Background Sampling in the absence of accurate or comprehensive information routinely poses logistical, ethical, and resource allocation challenges in social science, clinical, epidemiological, health service and population health research. These challenges are compounded if few members of a target population know each other or regularly interact. This paper reports on the sampling methods adopted in ethnographic case study research with a 'hard-to-reach' population. Methods To identify and engage a small yet diverse sample of people who met an unusual set of criteria (i.e., pet owners who had been treating cats or dogs for diabetes, four sampling strategies were used. First, copies of a recruitment letter were posted in pet-friendly places. Second, information about the study was diffused throughout the study period via word of mouth. Third, the lead investigator personally sent the recruitment letter via email to a pet owner, who then circulated the information to others, and so on. Fourth, veterinarians were enlisted to refer people who had diabetic pets. The second, third and fourth strategies rely on social networks and represent forms of chain referral sampling. Results Chain referral sampling via email proved to be the most efficient and effective, yielding a small yet diverse group of respondents within one month, and at negligible cost. Conclusions The widespread popularity of electronic communication technologies offers new methodological opportunities for researchers seeking to recruit from hard-to-reach populations.

  18. Harnessing social networks along with consumer-driven electronic communication technologies to identify and engage members of 'hard-to-reach' populations: a methodological case report.

    Science.gov (United States)

    Rock, Melanie J

    2010-01-20

    Sampling in the absence of accurate or comprehensive information routinely poses logistical, ethical, and resource allocation challenges in social science, clinical, epidemiological, health service and population health research. These challenges are compounded if few members of a target population know each other or regularly interact. This paper reports on the sampling methods adopted in ethnographic case study research with a 'hard-to-reach' population. To identify and engage a small yet diverse sample of people who met an unusual set of criteria (i.e., pet owners who had been treating cats or dogs for diabetes), four sampling strategies were used. First, copies of a recruitment letter were posted in pet-friendly places. Second, information about the study was diffused throughout the study period via word of mouth. Third, the lead investigator personally sent the recruitment letter via email to a pet owner, who then circulated the information to others, and so on. Fourth, veterinarians were enlisted to refer people who had diabetic pets. The second, third and fourth strategies rely on social networks and represent forms of chain referral sampling. Chain referral sampling via email proved to be the most efficient and effective, yielding a small yet diverse group of respondents within one month, and at negligible cost. The widespread popularity of electronic communication technologies offers new methodological opportunities for researchers seeking to recruit from hard-to-reach populations.

  19. Student Off-Task Electronic Multitasking Predictors: Scale Development and Validation

    Science.gov (United States)

    Qian, Yuxia; Li, Li

    2017-01-01

    In an attempt to better understand factors contributing to students' off-task electronic multitasking behavior in class, the research included two studies that developed a scale of students' off-task electronic multitasking predictors (the SOTEMP scale), and explored relationships between the scale and various classroom communication processes and…

  20. The Effect of Electron versus Hole Photocurrent on Optoelectric Properties of p+-p-n-n+ Wz-GaN Reach-Through Avalanche Photodiodes

    Directory of Open Access Journals (Sweden)

    Moumita Ghosh

    2013-01-01

    Full Text Available The authors have made an attempt to investigate the effect of electron versus hole photocurrent on the optoelectric properties of p+-p-n-n+ structured Wurtzite-GaN (Wz-GaN reach-through avalanche photodiodes (RAPDs. The photo responsivity and optical gain of the devices are obtained within the wavelength range of 300 to 450 nm using a novel modeling and simulation technique developed by the authors. Two optical illumination configurations of the device such as Top Mounted (TM and Flip Chip (FC are considered for the present study to investigate the optoelectric performance of the device separately due to electron dominated and hole dominated photocurrents, respectively, in the visible-blind ultraviolet (UV spectrum. The results show that the peak unity gain responsivity and corresponding optical gain of the device are 555.78 mA W−1 and 9.4144×103, respectively, due to hole dominated photocurrent (i.e., in FC structure; while those are 480.56 mA W−1 and 7.8800×103, respectively, due to electron dominated photocurrent (i.e., in TM structure at the wavelength of 365 nm and for applied reverse bias of 85 V. Thus, better optoelectric performance of Wz-GaN RAPDs can be achieved when the photocurrent is made hole dominated by allowing the UV light to be shined on the n+-layer instead of p+-layer of the device.

  1. Tests of the MICE Electron Muon Ranger frontend electronics with a small scale prototype

    Science.gov (United States)

    Bolognini, D.; Bene, P.; Blondel, A.; Cadoux, F.; Debieux, S.; Giannini, G.; Graulich, J. S.; Lietti, D.; Masciocchi, F.; Prest, M.; Rothenfusser, K.; Vallazza, E.; Wisting, H.

    2011-08-01

    The MICE experiment is being commissioned at RAL to demonstrate the feasibility of the muon ionization cooling technique for future applications such as the Neutrino Factory and the Muon Collider. The cooling will be evaluated by measuring the emittance before and after the cooling channel with two 4 T spectrometers; to distinguish muons from the background, a multi-detector particle identification system is foreseen: three Time of Flight stations, two Cherenkov counters and a calorimetric system consisting of a pre-shower layer and a fully active scintillator detector (EMR) are used to discriminate muons from pions and electrons. EMR consists of 48 planes of triangular scintillating bars coupled to WLS fibers readout by single PMTs on one side and MAPMTs on the other; each plane sensible area is 1 m 2. This article deals with a small scale prototype of the EMR detector which has been used to test the MAPMT frontend electronics based on the MAROC ASIC; the tests with cosmic rays using both an analog mode and a digital readout mode are presented. A very preliminary study on the cross talk problem is also shown.

  2. Tests of the MICE Electron Muon Ranger frontend electronics with a small scale prototype

    Energy Technology Data Exchange (ETDEWEB)

    Bolognini, D., E-mail: davide.bolognini@gmail.com [Universita degli Studi dell' Insubria, Via Valleggio 11, 22100 Como (Italy); INFN Milano Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Bene, P.; Blondel, A.; Cadoux, F.; Debieux, S. [Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve (Switzerland); Giannini, G. [Universita degli Studi di Trieste, Via A.Valerio, 34127 Trieste (Italy); INFN Trieste, Padriciano 99, 34012 Trieste (Italy); Graulich, J.S. [Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve (Switzerland); Lietti, D. [Universita degli Studi dell' Insubria, Via Valleggio 11, 22100 Como (Italy); INFN Milano Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Masciocchi, F. [Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve (Switzerland); Prest, M. [Universita degli Studi dell' Insubria, Via Valleggio 11, 22100 Como (Italy); INFN Milano Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Rothenfusser, K. [Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve (Switzerland); Vallazza, E. [INFN Trieste, Padriciano 99, 34012 Trieste (Italy); Wisting, H. [Universite de Geneve, Quai Ernest-Ansermet 24, 1211 Geneve (Switzerland)

    2011-08-01

    The MICE experiment is being commissioned at RAL to demonstrate the feasibility of the muon ionization cooling technique for future applications such as the Neutrino Factory and the Muon Collider. The cooling will be evaluated by measuring the emittance before and after the cooling channel with two 4 T spectrometers; to distinguish muons from the background, a multi-detector particle identification system is foreseen: three Time of Flight stations, two Cherenkov counters and a calorimetric system consisting of a pre-shower layer and a fully active scintillator detector (EMR) are used to discriminate muons from pions and electrons. EMR consists of 48 planes of triangular scintillating bars coupled to WLS fibers readout by single PMTs on one side and MAPMTs on the other; each plane sensible area is 1 m{sup 2}. This article deals with a small scale prototype of the EMR detector which has been used to test the MAPMT frontend electronics based on the MAROC ASIC; the tests with cosmic rays using both an analog mode and a digital readout mode are presented. A very preliminary study on the cross talk problem is also shown.

  3. Electronic Government in the City of Fez, Morocco : Scaling up to the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Electronic Government in the City of Fez, Morocco : Scaling up to the National Level. In the pilot phase of the project (101980), electronic service delivery was introduced and successfully deployed in the Fez-Agdal local government office. This phase will scale up the project to include the remaining local government offices ...

  4. Experimental design of high energy electron gun by means of scaling rules

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1996-01-01

    The possibility of the design of a new family of electron guns by means of scaling theory of electron-optical devices (EOD) is presented. According to the theory, EOD with a relatively big space charge, as in high energy Pierce type electron guns used in technological equipment, generally cannot be scaled, because of their nonlinear space charge nature. Therefore, the scaling rules are applied here only to the anode zone of the gun, where the electron beam perveance is small, and the cathode lens of gun with considerable space charge remains unchanged. The procedure for scaling a 25 kV and 150 mA gun with cylindrical electron beam into a high voltage 75 kV and 150 mA electron system is given. An experimental investigation proved the high technological quality of a high voltage gun constructed according to the above conception. (author)

  5. Electronic Structure of Large-Scale Graphene Nanoflakes

    OpenAIRE

    Hu, Wei; Lin, Lin; Yang, Chao; Yang, Jinlong

    2014-01-01

    With the help of the recently developed SIESTA-PEXSI method [J. Phys.: Condens. Matter \\textbf{26}, 305503 (2014)], we perform Kohn-Sham density functional theory (DFT) calculations to study the stability and electronic structure of hexagonal graphene nanoflakes (GNFs) with up to 11,700 atoms. We find the electronic properties of GNFs, including their cohesive energy, HOMO-LUMO energy gap, edge states and aromaticity, depend sensitively on the type of edges (ACGNFs and ZZGNFs), size and the n...

  6. A Bird's-eye View with X-ray Vision: Remote-sensing tools to Monitor Reach-scale Response to Dam Removal on the Elwha River

    Science.gov (United States)

    Ritchie, A. C.

    2012-12-01

    Repeat digital surface models, orthoimagery and sidescan sonar data are being generated to monitor river response to the largest dam removal and controlled sediment release in history on the Elwha River, on the Olympic Peninsula in Washington State. These products are generated using low-cost readily-available tools to collect data at a spatial and temporal scale that provides important insight into effects of base-level change, sediment release, and discrete hydrologic events on erosion of reservoir sediments, downstream sediment transport, and channel evolution above and below the dam sites. In combination, these products provide a view above and below the water surface to changes in sediment composition and morphology that other methods cannot capture at this spatial scale and both spatial and temporal resolution. Orthoimagery is developed from still images collected with a plane-mounted point-and-shoot camera using customized firmware from the open-source Canon Hack Development Kit (CHDK) with a total hardware cost of about $300 USD. Images are processed using structure-from-motion algorithms. Several software options are available. Sonar data are collected from a raft-mounted platform using a high-resolution 990 KHz Starfish sidescan sonar, with a water-resistant topside enclosure holding top-side electronics. A steerable pole-mount was developed for this application to allow the sidescan to to remain oriented in the direction of motion-over-ground.; Surface reconstruction from aerial images collected during Elwha dam removal project. ; bedforms near Elwha Sediment Treatment Plant from sediment released from Lake Aldwell, surveyed 12 July 2012.

  7. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    Science.gov (United States)

    Kurucz, Charles N.; Waite, Thomas D.; Otaño, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-11-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater.

  8. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    International Nuclear Information System (INIS)

    Kurucz, Charles N.; Waite, Thomas D.; Otano, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-01-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1 ) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60 Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater

  9. Implementation of the Agitated Behavior Scale in the Electronic Health Record.

    Science.gov (United States)

    Wilson, Helen John; Dasgupta, Kritis; Michael, Kathleen

    The purpose of the study was to implement an Agitated Behavior Scale through an electronic health record and to evaluate the usability of the scale in a brain injury unit at a rehabilitation hospital. A quality improvement project was conducted in the brain injury unit at a large rehabilitation hospital with registered nurses as participants using convenience sampling. The project consisted of three phases and included education, implementation of the scale in the electronic health record, and administration of the survey questionnaire, which utilized the system usability scale. The Agitated Behavior Scale was found to be usable, and there was 92.2% compliance with the use of the electronic Electronic Agitated Behavior Scale. The Agitated Behavior Scale was effectively implemented in the electronic health record and was found to be usable in the assessment of agitation. Utilization of the scale through the electronic health record on a daily basis will allow for an early identification of agitation in patients with traumatic brain injury and enable prompt interventions to manage agitation.

  10. MIXING THE SOLAR WIND PROTON AND ELECTRON SCALES: EFFECTS OF ELECTRON TEMPERATURE ANISOTROPY ON THE OBLIQUE PROTON FIREHOSE INSTABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Maneva, Y.; Lazar, M.; Poedts, S. [Centre for Mathematical Plasma Astrophysics, Celestijnenlaan 200B, 3001 Heverlee (Belgium); Viñas, A., E-mail: yana.maneva@wis.kuleuven.be [NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, MD 20771 (United States)

    2016-11-20

    The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons, unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma β and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.

  11. Mixing the Solar Wind Proton and Electron Scales: Effects of Electron Temperature Anisotropy on the Oblique Proton Firehose Instability

    Science.gov (United States)

    Maneva, Y.; Lazar, M.; Vinas, A.; Poedts, S.

    2016-01-01

    The double adiabatic expansion of the nearly collisionless solar wind plasma creates conditions for the firehose instability to develop and efficiently prevent the further increase of the plasma temperature in the direction parallel to the interplanetary magnetic field. The conditions imposed by the firehose instability have been extensively studied using idealized approaches that ignore the mutual effects of electrons and protons. Recently, more realistic approaches have been proposed that take into account the interplay between electrons and protons,? unveiling new regimes of the parallel oscillatory modes. However, for oblique wave propagation the instability develops distinct branches that grow much faster and may therefore be more efficient than the parallel firehose instability in constraining the temperature anisotropy of the plasma particles. This paper reports for the first time on the effects of electron plasma properties on the oblique proton firehose (PFH) instability and provides a comprehensive vision of the entire unstable wave-vector spectrum, unifying the proton and the smaller electron scales. The plasma ß and temperature anisotropy regimes considered here are specific for the solar wind and magnetospheric conditions, and enable the electrons and protons to interact via the excited electromagnetic fluctuations. For the selected parameters, simultaneous electron and PFH instabilities can be observed with a dispersion spectrum of the electron firehose (EFH) extending toward the proton scales. Growth rates of the PFH instability are markedly boosted by the anisotropic electrons, especially in the oblique direction where the EFH growth rates are orders of magnitude higher.

  12. Electron-Scale Measurements of Magnetic Reconnection in Space

    Science.gov (United States)

    Burch, J. L.; Torbert, R. B.; Phan, T. D.; Chen, L.-J.; Moore, T. E.; Ergun, R. E.; Eastwood, J. P.; Gershman, D. J.; Cassak, P. A.; Argall, M. R.; hide

    2016-01-01

    Magnetic reconnection is a fundamental physical process in plasmas whereby stored magnetic energy is converted into heat and kinetic energy of charged particles. Reconnection occurs in many astrophysical plasma environments and in laboratory plasmas. Using measurements with very high time resolution, NASA's Magnetospheric Multiscale (MMS) mission has found direct evidence for electron demagnetization and acceleration at sites along the sunward boundary of Earth's magnetosphere where the interplanetary magnetic field reconnects with the terrestrial magnetic field. We have (i) observed the conversion of magnetic energy to particle energy; (ii) measured the electric field and current, which together cause the dissipation of magnetic energy; and (iii) identified the electron population that carries the current as a result of demagnetization and acceleration within the reconnection diffusion/dissipation region.

  13. Determination of Longitudinal Electron Bunch Lengths on Picosecond Time Scales

    CERN Document Server

    Martínez, C; Calviño, F

    1999-01-01

    At CERN (European Laboratory for Particle Physics) the CLIC (Compact Linear Collider) study is pursuing the design of an electron-positron high-energy linear collider using an innovative concept for the RF (Radio Frequency) power production, the socalled two-beam acceleration scheme. In order to keep the length of the collider in a reasonable range while being able of accelerating electrons and positrons up to 5 TeV, the normal-conducting accelerating structures should operate at very high frequency (in this case 30 GHz). The RF power necessary to feed the accelerating cavities is provided by a second electron beam, the drive beam, running parallel to the main beam. The CLIC Test Facility (CTF) was build with the main aim of studying and demonstrating the feasibility of the two beam acceleration scheme and technology. It is composed of two beams, the drive beam that will generate the 30 GHz RF power and the main beam which will be accelerated by this power. In order to have a good efficiency for the power gen...

  14. 3D Reconstruction of a Fluvial Sediment Slug from Source to Sink: reach-scale modeling of the Dart River, NZ

    Science.gov (United States)

    Brasington, J.; Cook, S.; Cox, S.; James, J.; Lehane, N.; McColl, S. T.; Quincey, D. J.; Williams, R. D.

    2014-12-01

    Following heavy rainfall on 4/1/14, a debris flow at Slip Stream (44.59 S 168.34 E) introduced >106 m3 of sediment to the Dart River valley floor in NZ Southern Alps. Runout over an existing fan dammed the Dart River causing a sudden drop in discharge downstream. This broad dam was breached quickly; however the temporary loss of conveyance impounded a 3 km lake with a volume of 6 x 106 m3 and depths that exceed 10 m. Quantifying the impact of this large sediment pulse on the Dart River is urgently needed to assess potential sedimentation downstream and will also provide an ideal vehicle to test theories of bed wave migration in large, extensively braided rivers. Recent advances in geomatics offer the opportunity to study these impacts directly through the production of high-resolution DEMs. These 3D snapshots can then be compared through time to quantify the morphodynamic response of the channel as it adjusts to the change in sediment supply. In this study we describe the methods and results of a novel survey strategy designed to capture of the complex morphology of the Dart River along a remote 40 km reach, from the upstream landslide source to its distal sediment sink in Lake Wakatipu. The scale of this system presents major logistical and methodological challenges, and hitherto would have conventionally be addressed with airborne laser scanning, bringing with it significant deployment constraints and costs. By contrast, we present sub-metre 3D reconstructions of the system (Figure 1), derived from highly redundant aerial photography shot with a non-metric camera from a helicopter survey that extended over an 80 km2 area. Structure-from-Motion photogrammetry was used to solve simultaneously camera position, pose and derive a 3D point cloud based on over 4000 images. Reconstructions were found to exhibit significant systematic error resulting from the implicit estimation of the internal camera orientation parameters, and we show how these effects can be minimized

  15. Strengthening effect of nano-scaled precipitates in Ta alloying layer induced by high current pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Guangze; Luo, Dian; Fan, Guohua [School of Material Science & Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin, E-mail: maxin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2017-05-01

    Highlights: • Ta alloying layer are fabricated by magnetron sputtering and high current pulsed electron beam. • Nano-scaled TaC precipitates forms within the δ-Fe grain after tempering treatment. • The mean diameter of TaC particles is about 5–8 nm. • The hardness of alloying layer increased by over 50% after formation of nano-scaled TaC particle. - Abstract: In this study, the combination of magnetron sputtering and high current pulsed electron beam are used for surface alloying treatment of Ta film on high speed steel. And the Ta alloying layer is about 6 μm. After tempering treatment, TaC phase forms in Ta alloying layer when the treated temperature is over 823 K. Through the TEM and HRTEM observation, a large amount of nano-scaled precipitates (mean diameter 5–8 nm) form within the δ-Fe grain in Ta alloying layer after tempering treatment and these nano-scaled precipitates are confirmed as TaC particles, which contribute to the strengthening effect of the surface alloying layer. The hardness of tempered alloying layer can reach to 18.1 GPa when the treated temperature is 823 K which increase by 50% comparing with the untreated steel sample before surface alloying treatment.

  16. Electronic transport properties of copper and gold at atomic scale

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadzadeh, Saeideh

    2010-11-23

    The factors governing electronic transport properties of copper and gold atomic-size contacts are theoretically examined in the present work. A two-terminal conductor using crystalline electrodes is adopted. The non-equilibrium Green's function combined with the density functional tight-binding method is employed via gDFTB simulation tool to calculate the transport at both equilibrium and non-equilibrium conditions. The crystalline orientation, length, and arrangement of electrodes have very weak influence on the electronic characteristics of the considered atomic wires. The wire width is found to be the most effective geometric aspect determining the number of conduction channels. The obtained conductance oscillation and linear current-voltage curves are interpreted. To analyze the conduction mechanism in detail, the transmission channels and their decomposition to the atomic orbitals are calculated in copper and gold single point contacts. The presented results offer a possible explanation for the relation between conduction and geometric structure. Furthermore, the results are in good agreement with available experimental and theoretical studies. (orig.)

  17. Electron Scale Structures and Magnetic Reconnection Signatures in the Turbulent Magnetosheath

    Science.gov (United States)

    Yordanova, E.; Voros, Z.; Varsani, A.; Graham, D. B.; Norgren, C.; Khotyaintsev, Yu. V.; Vaivads, A.; Eriksson, E.; Nakamura, R.; Lindqvist, P.-A.; hide

    2016-01-01

    Collisionless space plasma turbulence can generate reconnecting thin current sheets as suggested by recent results of numerical magnetohydrodynamic simulations. The Magnetospheric Multiscale (MMS) mission provides the first serious opportunity to verify whether small ion-electron-scale reconnection, generated by turbulence, resembles the reconnection events frequently observed in the magnetotail or at the magnetopause. Here we investigate field and particle observations obtained by the MMS fleet in the turbulent terrestrial magnetosheath behind quasi-parallel bow shock geometry. We observe multiple small-scale current sheets during the event and present a detailed look of one of the detected structures. The emergence of thin current sheets can lead to electron scale structures. Within these structures, we see signatures of ion demagnetization, electron jets, electron heating, and agyrotropy suggesting that MMS spacecraft observe reconnection at these scales.

  18. Electron transport in nano-scaled piezoelectronic devices

    Science.gov (United States)

    Jiang, Zhengping; Kuroda, Marcelo A.; Tan, Yaohua; Newns, Dennis M.; Povolotskyi, Michael; Boykin, Timothy B.; Kubis, Tillmann; Klimeck, Gerhard; Martyna, Glenn J.

    2013-05-01

    The Piezoelectronic Transistor (PET) has been proposed as a post-CMOS device for fast, low-power switching. In this device, the piezoresistive channel is metalized via the expansion of a relaxor piezoelectric element to turn the device on. The mixed-valence compound SmSe is a good choice of PET channel material because of its isostructural pressure-induced continuous metal insulator transition, which is well characterized in bulk single crystals. Prediction and optimization of the performance of a realistic, nano-scaled PET based on SmSe requires the understanding of quantum confinement, tunneling, and the effect of metal interface. In this work, a computationally efficient empirical tight binding (ETB) model is developed for SmSe to study quantum transport in these systems and the scaling limit of PET channel lengths. Modulation of the SmSe band gap under pressure is successfully captured by ETB, and ballistic conductance shows orders of magnitude change under hydrostatic strain, supporting operability of the PET device at nanoscale.

  19. Lab-scale thermal analysis of electronic waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wu-Jun; Tian, Ke; Jiang, Hong, E-mail: jhong@ustc.edu.cn; Yu, Han-Qing

    2016-06-05

    Highlights: • We provided the experimental evidence that WEEE can be recovered by pyrolysis method. • We explored the thermochemical behaviors of WEEE using online TG–FTIR–MS technology. • The intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs. - Abstract: In this work, we experimentally revealed the thermochemical decomposition pathway of Decabromodiphenyl ethane (DBDPE) and tetrabromobisphenol A (TBBPA) containing electronic waste plastics using an online thermogravimetric–fourier transform infrared–mass spectroscopy (TG–FTIR–MS) system, a high resolution gas chromatography/high resolution mass (HRGC–MS) spectroscopy, and a fixed-bed reactor. We found the distribution and species of produced bromides can be easily controlled by adjusting pyrolytic temperature, which is particularly crucial to their recycle. From the analysis of the liquid and solid phase obtained from the fixed-bed reactor, we proposed that the ·Br radicals formed during the pyrolysis process may be captured by organic species derived from the depolymerization of plastics to form brominated compounds or by the inorganic species in the plastics, and that these species remained in the char residue after pyrolysis. Our work for the first time demonstrates intramolecular oxygen atoms play a pivotal role in the formation of PBDD/Fs that pyrolysis of oxygen-free BFRs is PBDD/Fs-free, whereas pyrolysis of oxygen-containing BFRs is PBDD/Fs-reduced.

  20. Science at the Time-scale of the Electron

    Science.gov (United States)

    Murnane, Margaret

    2010-03-01

    Replace this text with your abstract Ever since the invention of the laser 50 years ago and its application in nonlinear optics, scientists have been striving to extend coherent laser beams into the x-ray region of the spectrum. Very recently however, the prospects for tabletop coherent sources, with attosecond pulse durations, at very short wavelengths even in the hard x-ray region of the spectrum at wavelengths movie of how electron orbitals in a molecule change shape as a molecule breaks apart, following how fast a magnetic material can flip orientation, understanding how fast heat flows in a nanocircuit, or building a microscope without lenses. [4pt] [1] T. Popmintchev et al., ``Phase matched upconversion of coherent ultrafast laser light into the soft and hard x-ray regions of the spectrum'', PNAS 106, 10516 (2009). [0pt] [2] C. LaOVorakiat et al., ``Ultrafast Soft X-Ray Magneto-Optics at the M-edge Using a Tabletop High-Harmonic Source'', Physical Review Letters 103, 257402 (2009). [0pt] [3] M. Siemens et al. ``Measurement of quasi-ballistic heat transport across nanoscale interfaces using ultrafast coherent soft x-ray beams'', Nature Materials 9, 26 (2010). [0pt] [4] K. Raines et al., ``Three-dimensional structure determination from a single view,'' Nature 463, 214 (2010). [0pt] [5] W. Li et al., ``Time-resolved Probing of Dynamics in Polyatomic Molecules using High Harmonic Generation'', Science 322, 1207 (2008).

  1. Uncertainty of solute flux estimation in ungauged small streams: potential implications for input-output nutrient mass balances at stream reach scale

    Directory of Open Access Journals (Sweden)

    A. Butturini

    2005-01-01

    Full Text Available Input-output mass balances within stream reaches provide in situ estimates of stream nutrient retention/release under a wide spectrum of hydrological conditions. Providing good estimates of the mass balances for nutrients depends on precise hydrological monitoring and good chemical characterisation of stream water at the input and output ends of the stream reach. There is a need to optimise the hydrological monitoring and the frequencies of water sampling to yield precise annual mass balances, so as to avoid undue cost - high resolution monitoring and subsequent chemical analysis can be labour intensive and costly. In this paper, simulation exercises were performed using a data set created to represent the instantaneous discharge and solute dynamics at the input and output ends of a model stream reach during a one year period. At the output end, stream discharge and water chemistry were monitored continuously, while the input end was assumed to be ungauged; water sampling frequency was changed arbitrarily. Instantaneous discharge at the ungauged sampling point was estimated with an empirical power model linking the discharge to the catchment area (Hooper, 1986. The model thus substitutes for the additional gauge station. Simulations showed that 10 days was the longest chemical sampling interval which could provide reach annual mass balances of acceptable precision. Presently, the relationship between discharge and catchment area is usually assumed to be linear but simulations indicate that small departures from the linearity of this relationship could cause dramatic changes in the mass balance estimations.

  2. The research of selection model based on LOD in multi-scale display of electronic map

    Science.gov (United States)

    Zhang, Jinming; You, Xiong; Liu, Yingzhen

    2008-10-01

    This paper proposes a selection model based on LOD to aid the display of electronic map. The ratio of display scale to map scale is regarded as a LOD operator. The categorization rule, classification rule, elementary rule and spatial geometry character rule of LOD operator setting are also concluded.

  3. Effects of wave function correlations on scaling violation in quasi-free electron scattering

    International Nuclear Information System (INIS)

    Tornow, V.; Drechsel, D.; Orlandini, G.; Traini, M.

    1981-01-01

    The scaling law in quasi-free electron scattering is broken due to the existence of exchange forces, leading to a finite mean value of the scaling variable anti y. This effect is considerably increased by wave function correlations, in particular by tensor correlations, similar to the case of the photonuclear enhancement factor k. (orig.)

  4. Finite size scaling analysis of disordered electron systems

    International Nuclear Information System (INIS)

    Markos, P.

    2012-01-01

    We demonstrated the application of the finite size scaling method to the analysis of the transition of the disordered system from the metallic to the insulating regime. The method enables us to calculate the critical point and the critical exponent which determines the divergence of the correlation length in the vicinity of the critical point. The universality of the metal-insulator transition was verified by numerical analysis of various physical parameters and the critical exponent was calculated with high accuracy for different disordered models. Numerically obtained value of the critical exponent for the three dimensional disordered model (1) has been recently supported by the semi-analytical work and verified by experimental optical measurements equivalent to the three dimensional disordered model (1). Another unsolved problem of the localization is the disagreement between numerical results and predictions of the analytical theories. At present, no analytical theory confirms numerically obtained values of critical exponents. The reason for this disagreement lies in the statistical character of the process of localization. The theory must consider all possible scattering processes on randomly distributed impurities. All physical variables are statistical quantities with broad probability distributions. It is in general not know how to calculate analytically their mean values. We believe that detailed numerical analysis of various disordered systems bring inspiration for the formulation of analytical theory. (authors)

  5. A scaling analysis of electronic localization in two-dimensional random media

    International Nuclear Information System (INIS)

    Ye Zhen

    2003-01-01

    By an improved scaling analysis, we suggest that there may appear two possibilities concerning the electronic localization in two-dimensional random media. The first is that all electronic states are localized in two dimensions, as conjectured previously. The second possibility is that electronic behaviors in two- and three-dimensional random systems are similar, in agreement with a recent calculation based on a direct calculation of the conductance with the use of the Kubo formula. In this case, non-localized states are possible in two dimensions, and have some peculiar properties. A few predictions are proposed. Moreover, the present analysis accommodates results from the previous scaling analysis

  6. PetaScale calculations of the electronic structures of nanostructures with hundreds of thousands of processors

    International Nuclear Information System (INIS)

    Wang, Lin-Wang; Zhao, Zhengji; Meza, Juan

    2006-01-01

    Density functional theory (DFT) is the most widely used ab initio method in material simulations. It accounts for 75% of the NERSC allocation time in the material science category. The DFT can be used to calculate the electronic structure, the charge density, the total energy and the atomic forces of a material system. With the advance of the HPC power and new algorithms, DFT can now be used to study thousand atom systems in some limited ways (e.g, a single selfconsistent calculation without atomic relaxation). But there are many problems which either requires much larger systems (e.g, >100,000 atoms), or many total energy calculation steps (e.g. for molecular dynamics or atomic relaxations). Examples include: grain boundary, dislocation energies and atomic structures, impurity transport and clustering in semiconductors, nanostructure growth, electronic structures of nanostructures and their internal electric fields. Due to the O(N 3 ) scaling of the conventional DFT algorithms (as implemented in codes like Qbox, Paratec, Petots), these problems are beyond the reach even for petascale computers. As the proposed petascale computers might have millions of processors, new computational paradigms and algorithms are needed to solve the above large scale problems. In particular, O(N) scaling algorithms with parallelization capability up to millions of processors are needed. For a large material science problem, a natural approach to achieve this goal is by divide-and-conquer method: to spatially divide the system into many small pieces, and solve each piece by a small local group of processors. This solves the O(N) scaling and the parallelization problem at the same time. However, the challenge of this approach is for how to divide the system into small pieces and how to patch them up without the trace of the spatial division. Here, we present a linear scaling 3 dimensional fragment (LS3DF) method which uses a novel division-patching scheme that cancels out the

  7. Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments.

    Science.gov (United States)

    Rosenberg, M J; Solodov, A A; Myatt, J F; Seka, W; Michel, P; Hohenberger, M; Short, R W; Epstein, R; Regan, S P; Campbell, E M; Chapman, T; Goyon, C; Ralph, J E; Barrios, M A; Moody, J D; Bates, J W

    2018-02-02

    Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (∼500 to 700  μm), electron temperature (∼3 to 5 keV), and laser intensity (6 to 16×10^{14}  W/cm^{2}) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ∼0.7% to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ∼4×10^{14} to ∼6×10^{14}  W/cm^{2}. These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

  8. Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments

    Science.gov (United States)

    Rosenberg, M. J.; Solodov, A. A.; Myatt, J. F.; Seka, W.; Michel, P.; Hohenberger, M.; Short, R. W.; Epstein, R.; Regan, S. P.; Campbell, E. M.; Chapman, T.; Goyon, C.; Ralph, J. E.; Barrios, M. A.; Moody, J. D.; Bates, J. W.

    2018-01-01

    Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (˜500 to 700 μ m ), electron temperature (˜3 to 5 keV), and laser intensity (6 to 16 ×1014 W /cm2 ) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ˜0.7 % to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ˜4×10 14 to ˜6 ×1014 W /cm2 . These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

  9. Development of the simulation package 'ELSES' for extra-large-scale electronic structure calculation

    International Nuclear Information System (INIS)

    Hoshi, T; Fujiwara, T

    2009-01-01

    An early-stage version of the simulation package 'ELSES' (extra-large-scale electronic structure calculation) is developed for simulating the electronic structure and dynamics of large systems, particularly nanometer-scale and ten-nanometer-scale systems (see www.elses.jp). Input and output files are written in the extensible markup language (XML) style for general users. Related pre-/post-simulation tools are also available. A practical workflow and an example are described. A test calculation for the GaAs bulk system is shown, to demonstrate that the present code can handle systems with more than one atom species. Several future aspects are also discussed.

  10. Positive semidefinite tensor factorizations of the two-electron integral matrix for low-scaling ab initio electronic structure.

    Science.gov (United States)

    Hoy, Erik P; Mazziotti, David A

    2015-08-14

    Tensor factorization of the 2-electron integral matrix is a well-known technique for reducing the computational scaling of ab initio electronic structure methods toward that of Hartree-Fock and density functional theories. The simplest factorization that maintains the positive semidefinite character of the 2-electron integral matrix is the Cholesky factorization. In this paper, we introduce a family of positive semidefinite factorizations that generalize the Cholesky factorization. Using an implementation of the factorization within the parametric 2-RDM method [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], we study several inorganic molecules, alkane chains, and potential energy curves and find that this generalized factorization retains the accuracy and size extensivity of the Cholesky factorization, even in the presence of multi-reference correlation. The generalized family of positive semidefinite factorizations has potential applications to low-scaling ab initio electronic structure methods that treat electron correlation with a computational cost approaching that of the Hartree-Fock method or density functional theory.

  11. Positive semidefinite tensor factorizations of the two-electron integral matrix for low-scaling ab initio electronic structure

    Energy Technology Data Exchange (ETDEWEB)

    Hoy, Erik P.; Mazziotti, David A., E-mail: damazz@uchicago.edu [Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

    2015-08-14

    Tensor factorization of the 2-electron integral matrix is a well-known technique for reducing the computational scaling of ab initio electronic structure methods toward that of Hartree-Fock and density functional theories. The simplest factorization that maintains the positive semidefinite character of the 2-electron integral matrix is the Cholesky factorization. In this paper, we introduce a family of positive semidefinite factorizations that generalize the Cholesky factorization. Using an implementation of the factorization within the parametric 2-RDM method [D. A. Mazziotti, Phys. Rev. Lett. 101, 253002 (2008)], we study several inorganic molecules, alkane chains, and potential energy curves and find that this generalized factorization retains the accuracy and size extensivity of the Cholesky factorization, even in the presence of multi-reference correlation. The generalized family of positive semidefinite factorizations has potential applications to low-scaling ab initio electronic structure methods that treat electron correlation with a computational cost approaching that of the Hartree-Fock method or density functional theory.

  12. Comparison of the Mercury and earth magnetospheres - electron measurements and substorm time scales

    International Nuclear Information System (INIS)

    Christon, S.P.

    1987-01-01

    The present search for similarities between earth and Mercury plasma electron distribution and large-scale dynamics notes that both spectral shapes are similar to a kappa-distribution. A model distribution of this type which incorporates convective flow is used to simulate the observed plasma electron spectral variations near the Mariner 10-Mercury 1 A event; convection appears to be stronger before, rather than during, the A event, in contradiction to the Baker (1986) convective injection model for Mercury's two relativistic electron flux enhancements. Mercury's postmidnight energetic electron B and B-prime events seem to be multiple onsets in the course of a substorm. 65 references

  13. Monolithic Ge-on-Si lasers for large-scale electronic-photonic integration

    Science.gov (United States)

    Liu, Jifeng; Kimerling, Lionel C.; Michel, Jurgen

    2012-09-01

    A silicon-based monolithic laser source has long been envisioned as a key enabling component for large-scale electronic-photonic integration in future generations of high-performance computation and communication systems. In this paper we present a comprehensive review on the development of monolithic Ge-on-Si lasers for this application. Starting with a historical review of light emission from the direct gap transition of Ge dating back to the 1960s, we focus on the rapid progress in band-engineered Ge-on-Si lasers in the past five years after a nearly 30-year gap in this research field. Ge has become an interesting candidate for active devices in Si photonics in the past decade due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS) processing. In 2007, we proposed combing tensile strain with n-type doping to compensate the energy difference between the direct and indirect band gap of Ge, thereby achieving net optical gain for CMOS-compatible diode lasers. Here we systematically present theoretical modeling, material growth methods, spontaneous emission, optical gain, and lasing under optical and electrical pumping from band-engineered Ge-on-Si, culminated by recently demonstrated electrically pumped Ge-on-Si lasers with >1 mW output in the communication wavelength window of 1500-1700 nm. The broad gain spectrum enables on-chip wavelength division multiplexing. A unique feature of band-engineered pseudo-direct gap Ge light emitters is that the emission intensity increases with temperature, exactly opposite to conventional direct gap semiconductor light-emitting devices. This extraordinary thermal anti-quenching behavior greatly facilitates monolithic integration on Si microchips where temperatures can reach up to 80 °C during operation. The same band-engineering approach can be extended to other pseudo-direct gap semiconductors, allowing us to achieve efficient light emission at wavelengths previously

  14. Multi-scale modelling and numerical simulation of electronic kinetic transport

    International Nuclear Information System (INIS)

    Duclous, R.

    2009-11-01

    This research thesis which is at the interface between numerical analysis, plasma physics and applied mathematics, deals with the kinetic modelling and numerical simulations of the electron energy transport and deposition in laser-produced plasmas, having in view the processes of fuel assembly to temperature and density conditions necessary to ignite fusion reactions. After a brief review of the processes at play in the collisional kinetic theory of plasmas, with a focus on basic models and methods to implement, couple and validate them, the author focuses on the collective aspect related to the free-streaming electron transport equation in the non-relativistic limit as well as in the relativistic regime. He discusses the numerical development and analysis of the scheme for the Vlasov-Maxwell system, and the selection of a validation procedure and numerical tests. Then, he investigates more specific aspects of the collective transport: the multi-specie transport, submitted to phase-space discontinuities. Dealing with the multi-scale physics of electron transport with collision source terms, he validates the accuracy of a fast Monte Carlo multi-grid solver for the Fokker-Planck-Landau electron-electron collision operator. He reports realistic simulations for the kinetic electron transport in the frame of the shock ignition scheme, the development and validation of a reduced electron transport angular model. He finally explores the relative importance of the processes involving electron-electron collisions at high energy by means a multi-scale reduced model with relativistic Boltzmann terms

  15. Electron Debye scale Kelvin-Helmholtz instability: Electrostatic particle-in-cell simulations

    International Nuclear Information System (INIS)

    Lee, Sang-Yun; Lee, Ensang; Kim, Khan-Hyuk; Lee, Dong-Hun; Seon, Jongho; Jin, Ho

    2015-01-01

    In this paper, we investigated the electron Debye scale Kelvin-Helmholtz (KH) instability using two-dimensional electrostatic particle-in-cell simulations. We introduced a velocity shear layer with a thickness comparable to the electron Debye length and examined the generation of the KH instability. The KH instability occurs in a similar manner as observed in the KH instabilities in fluid or ion scales producing surface waves and rolled-up vortices. The strength and growth rate of the electron Debye scale KH instability is affected by the structure of the velocity shear layer. The strength depends on the magnitude of the velocity and the growth rate on the velocity gradient of the shear layer. However, the development of the electron Debye scale KH instability is mainly determined by the electric field generated by charge separation. Significant mixing of electrons occurs across the shear layer, and a fraction of electrons can penetrate deeply into the opposite side fairly far from the vortices across the shear layer

  16. Optically isolated electronic trigger system for experiments on a subnanosecond time scale with a pulsed Van de Graaff electron accelerator

    International Nuclear Information System (INIS)

    Luthjens, L.H.; Vermeulen, M.J.W.; Hom, M.L.

    1980-01-01

    An optically isolated electronic trigger system for a pulsed Van de Graaff electron accelerator, producing an external pretrigger pulse 75 ns before arrival of the electron pulse at the target, is described. The total time jitter between trigger signal and electron pulse is 50 ps. The measurement of optical and electrical transients on a subnanosecond time scale with a sequential sampling oscilloscope is demonstrated. The contribution of various parts of the equipment to the total jitter is discussed. Those contributions to the jitter due to the electron transit time fluctuations in the accelerator assuming a constant acceleration voltage gradient and to the shot noise in the photomultiplier detector of the trigger system are calculated to be 5 ps and 12 to 21 ps respectively. Comparison with the experimental results leads to the conclusion that a considerable part of the total jitter may be attributed to acceleration voltage gradient fluctuations, to accelerator vibrations and possibly to density fluctuations in the insulation gas. Possible improvements of the trigger system are discussed. The apparatus is used for pulse radiolysis experiments with subnanosecond time resolution down to 100 ps in combination with subnanosecond time duration electron pulses

  17. Variability of the Magnetic Field Power Spectrum in the Solar Wind at Electron Scales

    Science.gov (United States)

    Roberts, Owen Wyn; Alexandrova, O.; Kajdič, P.; Turc, L.; Perrone, D.; Escoubet, C. P.; Walsh, A.

    2017-12-01

    At electron scales, the power spectrum of solar-wind magnetic fluctuations can be highly variable and the dissipation mechanisms of the magnetic energy into the various particle species is under debate. In this paper, we investigate data from the Cluster mission’s STAFF Search Coil magnetometer when the level of turbulence is sufficiently high that the morphology of the power spectrum at electron scales can be investigated. The Cluster spacecraft sample a disturbed interval of plasma where two streams of solar wind interact. Meanwhile, several discontinuities (coherent structures) are seen in the large-scale magnetic field, while at small scales several intermittent bursts of wave activity (whistler waves) are present. Several different morphologies of the power spectrum can be identified: (1) two power laws separated by a break, (2) an exponential cutoff near the Taylor shifted electron scales, and (3) strong spectral knees at the Taylor shifted electron scales. These different morphologies are investigated by using wavelet coherence, showing that, in this interval, a clear break and strong spectral knees are features that are associated with sporadic quasi parallel propagating whistler waves, even for short times. On the other hand, when no signatures of whistler waves at ∼ 0.1{--}0.2{f}{ce} are present, a clear break is difficult to find and the spectrum is often more characteristic of a power law with an exponential cutoff.

  18. Magnetic field structure influence on primary electron cusp losses for micro-scale discharges

    International Nuclear Information System (INIS)

    Dankongkakul, Ben; Araki, Samuel J.; Wirz, Richard E.

    2014-01-01

    An experimental effort was used to examine the primary electron loss behavior for micro-scale (≲3 cm diameter) discharges. The experiment uses an electron flood gun source and an axially aligned arrangement of ring-cusps to guide the electrons to a downstream point cusp. Measurements of the electron current collected at the point cusp show an unexpectedly complex loss pattern with azimuthally periodic structures. Additionally, in contrast to conventional theory for cusp losses, the overall radii of the measured collection areas are over an order of magnitude larger than the electron gyroradius. Comparing these results to Monte Carlo particle tracking simulations and a simplified analytical analysis shows that azimuthal asymmetries of the magnetic field far upstream of the collection surface can substantially affect the electron loss structure and overall loss area

  19. Unconventional scaling of the anomalous Hall effect accompanying electron localization correction in the dirty regime

    KAUST Repository

    Lu, Y. M.

    2013-03-05

    Scaling of the anomalous Hall conductivity to longitudinal conductivity σAH∝σ2xx has been observed in the dirty regime of two-dimensional weak and strong localization regions in ultrathin, polycrystalline, chemically disordered, ferromagnetic FePt films. The relationship between electron transport and temperature reveals a quantitatively insignificant Coulomb interaction in these films, while the temperature dependent anomalous Hall conductivity experiences quantum correction from electron localization. At the onset of this correction, the low-temperature anomalous Hall resistivity begins to be saturated when the thickness of the FePt film is reduced, and the corresponding Hall conductivity scaling exponent becomes 2, which is above the recent unified theory of 1.6 (σAH∝σ1.6xx). Our results strongly suggest that the correction of the electron localization modulates the scaling exponent of the anomalous Hall effect.

  20. Experimental study of parametric dependence of electron-scale turbulence in a spherical tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y.; Guttenfelder, W.; Kaye, S. M.; Mazzucato, E.; Bell, R. E.; Diallo, A.; LeBlanc, B. P. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Domier, C. W.; Lee, K. C. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2012-05-15

    Electron-scale turbulence is predicted to drive anomalous electron thermal transport. However, experimental study of its relation with transport is still in its early stage. On the National Spherical Tokamak Experiment (NSTX), electron-scale density fluctuations are studied with a novel tangential microwave scattering system with high radial resolution of {+-}2 cm. Here, we report a study of parametric dependence of electron-scale turbulence in NSTX H-mode plasmas. The dependence on density gradient is studied through the observation of a large density gradient variation in the core induced by an edge localized mode (ELM) event, where we found the first clear experimental evidence of density gradient stabilization of electron-gyro scale turbulence in a fusion plasma. This observation, coupled with linear gyro-kinetic calculations, leads to the identification of the observed instability as toroidal electron temperature gradient (ETG) modes. It is observed that longer wavelength ETG modes, k{sub Up-Tack }{rho}{sub s} Less-Than-Or-Equivalent-To 10 ({rho}{sub s} is the ion gyroradius at electron temperature and k{sub Up-Tack} is the wavenumber perpendicular to local equilibrium magnetic field), are most stabilized by density gradient, and the stabilization is accompanied by about a factor of two decrease in electron thermal diffusivity. Comparisons with nonlinear ETG gyrokinetic simulations show ETG turbulence may be able to explain the experimental electron heat flux observed before the ELM event. The collisionality dependence of electron-scale turbulence is also studied by systematically varying plasma current and toroidal field, so that electron gyroradius ({rho}{sub e}), electron beta ({beta}{sub e}), and safety factor (q{sub 95}) are kept approximately constant. More than a factor of two change in electron collisionality, {nu}{sub e}{sup *}, was achieved, and we found that the spectral power of electron-scale turbulence appears to increase as {nu}{sub e}{sup *} is

  1. The low-energy electron accelerator LEA for pilot scale operations

    International Nuclear Information System (INIS)

    Mehnert, R.; Klenert, P.

    1990-01-01

    An electron processor equipped with a linear cathode has been developed for use in pilot scale radiation processing. It can provide electron beam powers up to 6 kW at energies between 150 and 200 keV. The design of some components of the processor system and first results of its operation as part of a pilot unit for curing of furniture elements will be discussed. (author)

  2. Scaling law of runaway electrons in the HL-1M tokamak

    International Nuclear Information System (INIS)

    Zheng Yongzhen

    2005-01-01

    Runaway confinement time in ohmic and additionally heated tokamak plasmas presents an anomalous behavior in comparison with theoretical predictions based on neoclassical models. A one-dimensional numerical including generation and loss effects for runaway electrons is used to deduce the dependence of runaway energy ε τ on runaway confinement time. The simulation results are presented in the form of a scaling law for ε τ on plasma parameters. The scaling of ε τ and therefore the runaway confinement time and runaway electron diffusivity has been studied in the HL-1M tokamak, by measuring hard X-ray spectra under different experimental conditions. (authors)

  3. Reach Address Database (RAD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reach Address Database (RAD) stores the reach address of each Water Program feature that has been linked to the underlying surface water features (streams,...

  4. Large scale electronic structure calculations in the study of the condensed phase

    NARCIS (Netherlands)

    van Dam, H.J.J.; Guest, M.F.; Sherwood, P.; Thomas, J.M.H.; van Lenthe, J.H.; van Lingen, J.N.J.; Bailey, C.L.; Bush, I.J.

    2006-01-01

    We consider the role that large-scale electronic structure computations can now play in the modelling of the condensed phase. To structure our analysis, we consider four distict ways in which today's scientific targets can be re-scoped to take advantage of advances in computing resources: 1. time to

  5. Electronic Government in the City of Fez, Morocco : Scaling up to the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In the pilot phase of the project (101980), electronic service delivery was introduced and successfully deployed in the Fez-Agdal local government office. This phase will scale up the project to include the remaining local government offices in the city of Fez. It will also upgrade, enhance and complete the automation of the ...

  6. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y.; Wang, W. X.; LeBlanc, B. P.; Guttenfelder, W.; Kaye, S. M.; Ethier, S.; Mazzucato, E.; Bell, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-11-15

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. The observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.

  7. Structural Gray Matter Changes in the Hippocampus and the Primary Motor Cortex on An-Hour-to-One- Day Scale Can Predict Arm-Reaching Performance Improvement

    Directory of Open Access Journals (Sweden)

    Midori Kodama

    2018-06-01

    Full Text Available Recent studies have revealed rapid (e.g., hours to days training-induced cortical structural changes using magnetic resonance imaging (MRI. Currently, there is great interest in studying how such a rapid brain structural change affects behavioral improvement. Structural reorganization contributes to memory or enhanced information processing in the brain and may increase its capability of skill learning. If the gray matter (GM is capable of such rapid structural reorganization upon training, the extent of volume increase may characterize the learning process. To shed light on this issue, we conducted a case series study of 5-day visuomotor learning using neuroanatomical imaging, and analyzed the effect of rapid brain structural change on motor performance improvement via regression analysis. Participants performed an upper-arm reaching task under left-right mirror-reversal for five consecutive days; T1-weighted MR imaging was performed before training, after the first and fifth days, and 1 week and 1 month after training. We detected increase in GM volume on the first day (i.e., a few hours after the first training session in the primary motor cortex (M1, primary sensory cortex (S1, and in the hippocampal areas. Notably, regression analysis revealed that individual differences in such short-term increases were associated with the learning levels after 5 days of training. These results suggest that GM structural changes are not simply a footprint of previous motor learning but have some relationship with future motor learning. In conclusion, the present study provides new insight into the role of structural changes in causing functional changes during motor learning.

  8. Reaching mothers and babies with early postnatal home visits: the implementation realities of achieving high coverage in large-scale programs.

    Directory of Open Access Journals (Sweden)

    Deborah Sitrin

    Full Text Available BACKGROUND: Nearly half of births in low-income countries occur without a skilled attendant, and even fewer mothers and babies have postnatal contact with providers who can deliver preventive or curative services that save lives. Community-based maternal and newborn care programs with postnatal home visits have been tested in Bangladesh, Malawi, and Nepal. This paper examines coverage and content of home visits in pilot areas and factors associated with receipt of postnatal visits. METHODS: Using data from cross-sectional surveys of women with live births (Bangladesh 398, Malawi: 900, Nepal: 615, generalized linear models were used to assess the strength of association between three factors - receipt of home visits during pregnancy, birth place, birth notification - and receipt of home visits within three days after birth. Meta-analytic techniques were used to generate pooled relative risks for each factor adjusting for other independent variables, maternal age, and education. FINDINGS: The proportion of mothers and newborns receiving home visits within three days after birth was 57% in Bangladesh, 11% in Malawi, and 50% in Nepal. Mothers and newborns were more likely to receive a postnatal home visit within three days if the mother received at least one home visit during pregnancy (OR2.18, CI1.46-3.25, the birth occurred outside a facility (OR1.48, CI1.28-1.73, and the mother reported a CHW was notified of the birth (OR2.66, CI1.40-5.08. Checking the cord was the most frequently reported action; most mothers reported at least one action for newborns. CONCLUSIONS: Reaching mothers and babies with home visits during pregnancy and within three days after birth is achievable using existing community health systems if workers are available; linked to communities; and receive training, supplies, and supervision. In all settings, programs must evaluate what community delivery systems can handle and how to best utilize them to improve postnatal care

  9. Electron beam absorption in solid and in water phantoms: depth scaling and energy-range relations

    International Nuclear Information System (INIS)

    Grosswendt, B.; Roos, M.

    1989-01-01

    In electron dosimetry energy parameters are used with values evaluated from ranges in water. The electron ranges in water may be deduced from ranges measured in solid phantoms. Several procedures recommended by national and international organisations differ both in the scaling of the ranges and in the energy-range relations for water. Using the Monte Carlo method the application of different procedures for electron energies below 10 MeV is studied for different phantom materials. It is shown that deviations in the range scaling and in the energy-range relations for water may accumulate to give energy errors of several per cent. In consequence energy-range relations are deduced for several solid phantom materials which enable a single-step energy determination. (author)

  10. Two-Dimensional Simulations of Electron Shock Ignition at the Megajoule Scale

    Science.gov (United States)

    Shang, W.; Betti, R.

    2016-10-01

    Shock ignition uses a late strong shock to ignite the hot spot of an inertial confinement fusion capsule. In the standard shock-ignition scheme, an ignitor shock is launched by the ablation pressure from a spike in laser intensity. Recent experiments on OMEGA have shown that focused beams with intensity up to 6 ×1015 W /cm2 can produce copious amounts of hot electrons. The hot electrons are produced by laser-plasma instabilities (LPI's) and can carry up to 15 % of the instantaneous laser power. Megajoule-scale targets will likely produce even more hot electrons because of the large plasma scale length. We show that it is possible to design ignition targets with low implosion velocities that can be shock ignited using LPI-generated hot electrons to obtain high energy gains. These designs are robust to low-mode asymmetries and they ignite even for highly distorted implosions. Electron shock ignition requires tens of kilojoules of hot electrons, which can only be produced on a large laser facility like the National Ignition Facility. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  11. Treatment of municipal wastewater in full-scale on-site sand filter reduces BOD efficiently but does not reach requirements for nitrogen and phosphorus removal.

    Science.gov (United States)

    Laaksonen, Petteri; Sinkkonen, Aki; Zaitsev, Gennadi; Mäkinen, Esa; Grönroos, Timo; Romantschuk, Martin

    2017-04-01

    A traditional sand filter for treatment of household wastewater was constructed in the fall of 2012 at Biolinja 12, Turku, Finland. Construction work was led and monitored by an authorized wastewater treatment consultant. The filter was placed on a field bordered by open ditches from all sides in order to collect excess rain and snowmelt waters. The filter was constructed and insulated from the environment so that all outflowing water was accounted for. Untreated, mainly municipal, wastewater from Varissuo suburb was pumped from a sewer separately via three septic tanks (volume = 1 m 3 each) into the filters. Normally, wastewater was distributed to ground filters automatically according to pre-programmed schedule. Initially, the daily flow was 1200 L day -1 to reflect the average organic load of a household of five persons (load: ca 237 g day -1 BOD; 73 g day -1 total N; and 10.4 g day -1 total P). Later in the test, the flow rate was decreased first to 900 and then to 600 L day -1 to better reflect the average volume produced by five persons. Volumes of inlet wastewater as well as treated water were monitored by magnetic flow meters. Samples were withdrawn from the inlet water, from the water entering the filters after the third septic tank, and from the outflowing water. After an initial adaption time, the reductions in BOD and chemical oxygen demand were constantly between 92 and 98%, showing that the biological degradation process in the filters functioned optimally and clearly comply with the national and EU standards. The reduction in total nitrogen and total phosphorus, however, reached required levels only during the first months of testing, apparently when buildup of microbial biomass was still ongoing. After this initial period of 3 months showing satisfactory reduction levels, the reduction of total nitrogen varied between 5 and 25% and total phosphorus mostly between 50 and 65%. Nitrification was efficient in the filter, but as indicated

  12. Reaching the hard-to-reach.

    Science.gov (United States)

    Valdes, C

    1992-01-01

    Guatemala's family planning (FP) programs are innovative but contraceptive use is only 23%. Total fertility is 5.3 children/woman, and the 9.5 million population will double in 23 years. The problem is poverty and illiteracy among rural residents removed from health services. 80% live in poverty and 80% are illiterate. Government effort is devoted to combating diseases such as diarrhea so there are few funds for implementing a comprehensive population policy. There is support within the national government but FP lacks priority status. APROFAM's goals are to use innovative marketing methods to inform the rural population who lack access to and knowledge about FP. Service delivery is constrained by the difficulty in reaching remote areas where 4 out of 10 indigenous Guatemalans live. Infant mortality can reach as high as 200/1000 live births. Population growth has slowed, and APROFAM plans to reach 16,000 more in the future. Promotions are conducted in several languages and aired on radio, television, and in the print media. It has been found that market research is the most effective strategy in reaching indigenous families. APROFAM has also been effective in upgrading service facilities through training, client surveys, and setting improved clinic standards. Breastfeeding, training, and voluntary sterilization programs contribute to the primary care effort. The example is given of Paulina Lebron from a very poor area who has learned how to space her children and thus improve the standard of living for her family. Eventually, she convinced herself and her family that sterilization was necessary, and now the couple enjoy the bliss of newlyweds without fear of pregnancy.

  13. Proposal of balloon and satellite observations of MeV gammas using Electron Tracking Compton Camera for reaching a high sensitivity of 1 mCrab

    Science.gov (United States)

    Takada, Atsushi; Tanimori, Toru

    2016-04-01

    ETCC with a gas Time Projection Chamber (TPC) and pixel GSO scintillators, by measuring electron tracks precisely, provides both a strong background rejection by dE/dx of the track and well-defined 2-dimensional Point Spread Function (PDF) with better than several degrees by adding the arc direction of incident gammas (SPD: Scatter Plane Deviation) with the ARM (angular Resolution Measure) direction measured in standard Compton Camera (CC). In 2006 its background rejection was revealed by SMILE-I balloon experiment with 10cm-cubic ETCC using the dE/dx of tracks. In 2013, 30cm-cube-ETCC has been developed to catch gammas from Crab in next SMILE-II balloon with >5sigma detection for 4 hrs. Now its sensitivity has been improved to 10sigma by attaining the angular resolution of the track (SPD angle) to that determined by multiple scattering of the gas. Thus, we show the ability of ETCC to give a better significance by a factor of 10 than that of standard CCs having same detection area by electron tracking?and we have found that SPD is an essential to define the PSF of Compton imaging quantitatively. Such a well-defined PSF is, for the first time, able to provide reliable sensitivity in Compton imaging without assuming the use of optimization algorithm. These studies uncover the uncertainties of CCs from both points of view of the intense background and the difficulty of the definition of the PSF, and overcome the above problems. Based on this technology, SMILE-II with 3atm CF4 gas is expected to provide a 5times better sensitivity than COMPTEL in one month balloon, and 4modules of 50cm-cube ETCCs would exceed over 10^-12 erg/cm^2s^1 (1mCrab) in satellite. Here we summarize the performance of the ETCC and new astrophysics opened in near future by high sensitive observation of MeV gamma-rays.

  14. Simulation of electron energy loss spectra of nanomaterials with linear-scaling density functional theory

    International Nuclear Information System (INIS)

    Tait, E W; Payne, M C; Ratcliff, L E; Haynes, P D; Hine, N D M

    2016-01-01

    Experimental techniques for electron energy loss spectroscopy (EELS) combine high energy resolution with high spatial resolution. They are therefore powerful tools for investigating the local electronic structure of complex systems such as nanostructures, interfaces and even individual defects. Interpretation of experimental electron energy loss spectra is often challenging and can require theoretical modelling of candidate structures, which themselves may be large and complex, beyond the capabilities of traditional cubic-scaling density functional theory. In this work, we present functionality to compute electron energy loss spectra within the onetep linear-scaling density functional theory code. We first demonstrate that simulated spectra agree with those computed using conventional plane wave pseudopotential methods to a high degree of precision. The ability of onetep to tackle large problems is then exploited to investigate convergence of spectra with respect to supercell size. Finally, we apply the novel functionality to a study of the electron energy loss spectra of defects on the (1 0 1) surface of an anatase slab and determine concentrations of defects which might be experimentally detectable. (paper)

  15. Constraints on exotic dipole-dipole couplings between electrons at the micron scale

    Science.gov (United States)

    Kotler, Shlomi; Ozeri, Roee; Jackson Kimball, Derek

    2015-05-01

    Until recently, the magnetic dipole-dipole coupling between electrons had not been directly observed experimentally. This is because at the atomic scale dipole-dipole coupling is dominated by the exchange interaction and at larger distances the dipole-dipole coupling is overwhelmed by ambient magnetic field noise. In spite of these challenges, the magnetic dipole-dipole interaction between two electron spins separated by 2.4 microns was recently measured using the valence electrons of trapped Strontium ions [S. Kotler, N. Akerman, N. Navon, Y. Glickman, and R. Ozeri, Nature 510, 376 (2014)]. We have used this measurement to directly constrain exotic dipole-dipole interactions between electrons at the micron scale. For light bosons (mass 0.1 eV), we find that coupling constants describing pseudoscalar and axial-vector mediated interactions must be | gPegPe/4 πℏc | <= 1 . 5 × 10-3 and | gAegAe/4 πℏc | <= 1 . 2 × 10-17 , respectively, at the 90% confidence level. These bounds significantly improve on previous constraints in this mass range: for example, the constraints on axial-vector interactions are six orders of magnitude stronger than electron-positron constraints based on positronium spectroscopy. Supported by the National Science Foundation, I-Core: the Israeli excellence center, and the European Research Council.

  16. Constraints on Exotic Dipole-Dipole Couplings between Electrons at the Micrometer Scale.

    Science.gov (United States)

    Kotler, Shlomi; Ozeri, Roee; Kimball, Derek F Jackson

    2015-08-21

    New constraints on exotic dipole-dipole interactions between electrons at the micrometer scale are established, based on a recent measurement of the magnetic interaction between two trapped 88Sr(+) ions. For light bosons (mass≤0.1  eV) we obtain a 90% confidence interval for an axial-vector-mediated interaction strength of |g(A)(e)g(A)(e)/4πℏc|≤1.2×10(-17). Assuming CPT invariance, this constraint is compared to that on anomalous electron-positron interactions, derived from positronium hyperfine spectroscopy. We find that the electron-electron constraint is 6 orders of magnitude more stringent than the electron-positron counterpart. Bounds on pseudoscalar-mediated interaction as well as on torsion gravity are also derived and compared with previous work performed at different length scales. Our constraints benefit from the high controllability of the experimental system which contained only two trapped particles. It therefore suggests a useful new platform for exotic particle searches, complementing other experimental efforts.

  17. Three-dimensional analysis of free-electron laser performance using brightness scaled variables

    Directory of Open Access Journals (Sweden)

    M. Gullans

    2008-06-01

    Full Text Available A three-dimensional analysis of radiation generation in a free-electron laser (FEL is performed in the small signal regime. The analysis includes beam conditioning, harmonic generation, flat beams, and a new scaling of the FEL equations using the six-dimensional beam brightness. The six-dimensional beam brightness is an invariant under Liouvillian flow; therefore, any nondissipative manipulation of the phase space, performed, for example, in order to optimize FEL performance, must conserve this brightness. This scaling is more natural than the commonly used scaling with the one-dimensional growth rate. The brightness-scaled equations allow for the succinct characterization of the optimal FEL performance under various additional constraints. The analysis allows for the simple evaluation of gain enhancement schemes based on beam phase space manipulations such as emittance exchange and conditioning. An example comparing the gain in the first and third harmonics of round or flat and conditioned or unconditioned beams is presented.

  18. The effect of electron cyclotron heating on density fluctuations at ion and electron scales in ITER baseline scenario discharges on the DIII-D tokamak

    Science.gov (United States)

    Marinoni, A.; Pinsker, R. I.; Porkolab, M.; Rost, J. C.; Davis, E. M.; Burrell, K. H.; Candy, J.; Staebler, G. M.; Grierson, B. A.; McKee, G. R.; Rhodes, T. L.; The DIII-D Team

    2017-12-01

    Experiments simulating the ITER baseline scenario on the DIII-D tokamak show that torque-free pure electron heating, when coupled to plasmas subject to a net co-current beam torque, affects density fluctuations at electron scales on a sub-confinement time scale, whereas fluctuations at ion scales change only after profiles have evolved to a new stationary state. Modifications to the density fluctuations measured by the phase contrast imaging diagnostic (PCI) are assessed by analyzing the time evolution following the switch-off of electron cyclotron heating (ECH), thus going from mixed beam/ECH to pure neutral beam heating at fixed βN . Within 20 ms after turning off ECH, the intensity of fluctuations is observed to increase at frequencies higher than 200 kHz in contrast, fluctuations at lower frequency are seen to decrease in intensity on a longer time scale, after other equilibrium quantities have evolved. Non-linear gyro-kinetic modeling at ion and electron scales scales suggest that, while the low frequency response of the diagnostic is consistent with the dominant ITG modes being weakened by the slow-time increase in flow shear, the high frequency response is due to prompt changes to the electron temperature profile that enhance electron modes and generate a larger heat flux and an inward particle pinch. These results suggest that electron heated regimes in ITER will feature multi-scale fluctuations that might affect fusion performance via modifications to profiles.

  19. Large-Scale Direct-Writing of Aligned Nanofibers for Flexible Electronics.

    Science.gov (United States)

    Ye, Dong; Ding, Yajiang; Duan, Yongqing; Su, Jiangtao; Yin, Zhouping; Huang, Yong An

    2018-05-01

    Nanofibers/nanowires usually exhibit exceptionally low flexural rigidities and remarkable tolerance against mechanical bending, showing superior advantages in flexible electronics applications. Electrospinning is regarded as a powerful process for this 1D nanostructure; however, it can only be able to produce chaotic fibers that are incompatible with the well-patterned microstructures in flexible electronics. Electro-hydrodynamic (EHD) direct-writing technology enables large-scale deposition of highly aligned nanofibers in an additive, noncontact, real-time adjustment, and individual control manner on rigid or flexible, planar or curved substrates, making it rather attractive in the fabrication of flexible electronics. In this Review, the ground-breaking research progress in the field of EHD direct-writing technology is summarized, including a brief chronology of EHD direct-writing techniques, basic principles and alignment strategies, and applications in flexible electronics. Finally, future prospects are suggested to advance flexible electronics based on orderly arranged EHD direct-written fibers. This technology overcomes the limitations of the resolution of fabrication and viscosity of ink of conventional inkjet printing, and represents major advances in manufacturing of flexible electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. DNA electronic circular dichroism on the inter-base pair scale

    DEFF Research Database (Denmark)

    Di Meo, Florent; Nørby, Morten Steen; Rubio-Magnieto, Jenifer

    2015-01-01

    A successful elucidation of the near-ultraviolet electronic circular dichroism spectrum of a short double-stranded DNA is reported. Time-dependent density functional theory methods are shown to accurately predict spectra and assign bands on the microscopic base-pair scale, a finding that opens...... the field for using circular dichroism spectroscopy as a sensitive nanoscale probe of DNA to reveal its complex interactions with the environment. (Chemical Equation Presented)....

  1. Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration

    Energy Technology Data Exchange (ETDEWEB)

    Houshmandyar, S., E-mail: houshmandyar@austin.utexas.edu; Phillips, P. E.; Rowan, W. L. [Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States); Yang, Z. J. [Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Hubbard, A. E.; Rice, J. E.; Hughes, J. W.; Wolfe, S. M. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129 (United States)

    2016-11-15

    Calibration is a crucial procedure in electron temperature (T{sub e}) inference from a typical electron cyclotron emission (ECE) diagnostic on tokamaks. Although the calibration provides an important multiplying factor for an individual ECE channel, the parameter ΔT{sub e}/T{sub e} is independent of any calibration. Since an ECE channel measures the cyclotron emission for a particular flux surface, a non-perturbing change in toroidal magnetic field changes the view of that channel. Hence the calibration-free parameter is a measure of T{sub e} gradient. B{sub T}-jog technique is presented here which employs the parameter and the raw ECE signals for direct measurement of electron temperature gradient scale length.

  2. Graphene/MoS2 hybrid technology for large-scale two-dimensional electronics.

    Science.gov (United States)

    Yu, Lili; Lee, Yi-Hsien; Ling, Xi; Santos, Elton J G; Shin, Yong Cheol; Lin, Yuxuan; Dubey, Madan; Kaxiras, Efthimios; Kong, Jing; Wang, Han; Palacios, Tomás

    2014-06-11

    Two-dimensional (2D) materials have generated great interest in the past few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2), and insulating boron nitride. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. In this paper, we demonstrate a novel technology for constructing large-scale electronic systems based on graphene/molybdenum disulfide (MoS2) heterostructures grown by chemical vapor deposition. We have fabricated high-performance devices and circuits based on this heterostructure, where MoS2 is used as the transistor channel and graphene as contact electrodes and circuit interconnects. We provide a systematic comparison of the graphene/MoS2 heterojunction contact to more traditional MoS2-metal junctions, as well as a theoretical investigation, using density functional theory, of the origin of the Schottky barrier height. The tunability of the graphene work function with electrostatic doping significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on this 2D heterostructure pave the way for practical flexible transparent electronics.

  3. Energy loss of a high charge bunched electron beam in plasma: Simulations, scaling, and accelerating wakefields

    Directory of Open Access Journals (Sweden)

    J. B. Rosenzweig

    2004-06-01

    Full Text Available The energy loss and gain of a beam in the nonlinear, “blowout” regime of the plasma wakefield accelerator, which features ultrahigh accelerating fields, linear transverse focusing forces, and nonlinear plasma motion, has been asserted, through previous observations in simulations, to scale linearly with beam charge. Additionally, from a recent analysis by Barov et al., it has been concluded that for an infinitesimally short beam, the energy loss is indeed predicted to scale linearly with beam charge for arbitrarily large beam charge. This scaling is predicted to hold despite the onset of a relativistic, nonlinear response by the plasma, when the number of beam particles occupying a cubic plasma skin depth exceeds that of plasma electrons within the same volume. This paper is intended to explore the deviations from linear energy loss using 2D particle-in-cell simulations that arise in the case of experimentally relevant finite length beams. The peak accelerating field in the plasma wave excited behind the finite-length beam is also examined, with the artifact of wave spiking adding to the apparent persistence of linear scaling of the peak field amplitude into the nonlinear regime. At large enough normalized charge, the linear scaling of both decelerating and accelerating fields collapses, with serious consequences for plasma wave excitation efficiency. Using the results of parametric particle-in-cell studies, the implications of these results for observing severe deviations from linear scaling in present and planned experiments are discussed.

  4. Charged Particles Multiplicity and Scaling Violation of Fragmentation Functions in Electron-Positron Annihilation

    International Nuclear Information System (INIS)

    Ghaffary, Tooraj

    2016-01-01

    By the use of data from the annihilation process of electron-positron in AMY detector at 60 GeV center of mass energy, charged particles multiplicity distribution is obtained and fitted with the KNO scaling. Then, momentum spectra of charged particles and momentum distribution with respect to the jet axis are obtained, and the results are compared to the different models of QCD; also, the distribution of fragmentation functions and scaling violations are studied. It is being expected that the scaling violations of the fragmentation functions of gluon jets are stronger than the quark ones. One of the reasons for such case is that splitting function of quarks is larger than splitting function of gluon.

  5. Gyrokinetic Simulations of Solar Wind Turbulence from Ion to Electron Scales

    International Nuclear Information System (INIS)

    Howes, G. G.; TenBarge, J. M.; Dorland, W.; Numata, R.; Quataert, E.; Schekochihin, A. A.; Tatsuno, T.

    2011-01-01

    A three-dimensional, nonlinear gyrokinetic simulation of plasma turbulence resolving scales from the ion to electron gyroradius with a realistic mass ratio is presented, where all damping is provided by resolved physical mechanisms. The resulting energy spectra are quantitatively consistent with a magnetic power spectrum scaling of k -2.8 as observed in in situ spacecraft measurements of the 'dissipation range' of solar wind turbulence. Despite the strongly nonlinear nature of the turbulence, the linear kinetic Alfven wave mode quantitatively describes the polarization of the turbulent fluctuations. The collisional ion heating is measured at subion-Larmor radius scales, which provides evidence of the ion entropy cascade in an electromagnetic turbulence simulation.

  6. GPU-Accelerated Large-Scale Electronic Structure Theory on Titan with a First-Principles All-Electron Code

    Science.gov (United States)

    Huhn, William Paul; Lange, Björn; Yu, Victor; Blum, Volker; Lee, Seyong; Yoon, Mina

    Density-functional theory has been well established as the dominant quantum-mechanical computational method in the materials community. Large accurate simulations become very challenging on small to mid-scale computers and require high-performance compute platforms to succeed. GPU acceleration is one promising approach. In this talk, we present a first implementation of all-electron density-functional theory in the FHI-aims code for massively parallel GPU-based platforms. Special attention is paid to the update of the density and to the integration of the Hamiltonian and overlap matrices, realized in a domain decomposition scheme on non-uniform grids. The initial implementation scales well across nodes on ORNL's Titan Cray XK7 supercomputer (8 to 64 nodes, 16 MPI ranks/node) and shows an overall speed up in runtime due to utilization of the K20X Tesla GPUs on each Titan node of 1.4x, with the charge density update showing a speed up of 2x. Further acceleration opportunities will be discussed. Work supported by the LDRD Program of ORNL managed by UT-Battle, LLC, for the U.S. DOE and by the Oak Ridge Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC05-00OR22725.

  7. Teratology testing under REACH.

    Science.gov (United States)

    Barton, Steve

    2013-01-01

    REACH guidelines may require teratology testing for new and existing chemicals. This chapter discusses procedures to assess the need for teratology testing and the conduct and interpretation of teratology tests where required.

  8. Global reach and engagement

    Science.gov (United States)

    2016-09-01

    Popular culture reflects both the interests of and the issues affecting the general public. As concerns regarding climate change and its impacts grow, is it permeating into popular culture and reaching that global audience?

  9. THE EFFECT OF LARGE-SCALE MAGNETIC TURBULENCE ON THE ACCELERATION OF ELECTRONS BY PERPENDICULAR COLLISIONLESS SHOCKS

    International Nuclear Information System (INIS)

    Guo Fan; Giacalone, Joe

    2010-01-01

    We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as test particles moving in the time-dependent electric and magnetic fields determined from two-dimensional hybrid simulations (kinetic ions and fluid electron). The large-scale magnetic fluctuations effect the electrons in a number of ways and lead to efficient and rapid energization at the shock front. Since the electrons mainly follow along magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons to cross the shock front several times, leading to efficient acceleration. Ripples in the shock front occurring at various scales will also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. The current study is also helpful in understanding the injection problem for electron acceleration by collisionless shocks. It is also shown that the spatial distribution of energetic electrons is similar to in situ observations. The process may be important to our understanding of energetic electrons in planetary bow shocks and interplanetary shocks, and explaining herringbone structures seen in some type II solar radio bursts.

  10. Electron Energy Loss Spectroscopy imaging of surface plasmons at the nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Colliex, Christian, E-mail: christian.colliex@u-psud.fr; Kociak, Mathieu; Stéphan, Odile

    2016-03-15

    Since their first realization, electron microscopes have demonstrated their unique ability to map with highest spatial resolution (sub-atomic in most recent instruments) the position of atoms as a consequence of the strong scattering of the incident high energy electrons by the nuclei of the material under investigation. When interacting with the electron clouds either on atomic orbitals or delocalized over the specimen, the associated energy transfer, measured and analyzed as an energy loss (Electron Energy Loss Spectroscopy) gives access to analytical properties (atom identification, electron states symmetry and localization). In the moderate energy-loss domain (corresponding to an optical spectral domain from the infrared (IR) to the rather far ultra violet (UV), EELS spectra exhibit characteristic collective excitations of the rather-free electron gas, known as plasmons. Boundary conditions, such as surfaces and/or interfaces between metallic and dielectric media, generate localized surface charge oscillations, surface plasmons (SP), which are associated with confined electric fields. This domain of research has been extraordinarily revived over the past few years as a consequence of the burst of interest for structures and devices guiding, enhancing and controlling light at the sub-wavelength scale. The present review focuses on the study of these surface plasmons with an electron microscopy-based approach which associates spectroscopy and mapping at the level of a single and well-defined nano-object, typically at the nanometer scale i.e. much improved with respect to standard, and even near-field, optical techniques. After calling to mind some early studies, we will briefly mention a few basic aspects of the required instrumentation and associated theoretical tools to interpret the very rich data sets recorded with the latest generation of (Scanning)TEM microscopes. The following paragraphs will review in more detail the results obtained on simple planar and

  11. Electron Energy Loss Spectroscopy imaging of surface plasmons at the nanometer scale.

    Science.gov (United States)

    Colliex, Christian; Kociak, Mathieu; Stéphan, Odile

    2016-03-01

    Since their first realization, electron microscopes have demonstrated their unique ability to map with highest spatial resolution (sub-atomic in most recent instruments) the position of atoms as a consequence of the strong scattering of the incident high energy electrons by the nuclei of the material under investigation. When interacting with the electron clouds either on atomic orbitals or delocalized over the specimen, the associated energy transfer, measured and analyzed as an energy loss (Electron Energy Loss Spectroscopy) gives access to analytical properties (atom identification, electron states symmetry and localization). In the moderate energy-loss domain (corresponding to an optical spectral domain from the infrared (IR) to the rather far ultra violet (UV), EELS spectra exhibit characteristic collective excitations of the rather-free electron gas, known as plasmons. Boundary conditions, such as surfaces and/or interfaces between metallic and dielectric media, generate localized surface charge oscillations, surface plasmons (SP), which are associated with confined electric fields. This domain of research has been extraordinarily revived over the past few years as a consequence of the burst of interest for structures and devices guiding, enhancing and controlling light at the sub-wavelength scale. The present review focuses on the study of these surface plasmons with an electron microscopy-based approach which associates spectroscopy and mapping at the level of a single and well-defined nano-object, typically at the nanometer scale i.e. much improved with respect to standard, and even near-field, optical techniques. After calling to mind some early studies, we will briefly mention a few basic aspects of the required instrumentation and associated theoretical tools to interpret the very rich data sets recorded with the latest generation of (Scanning)TEM microscopes. The following paragraphs will review in more detail the results obtained on simple planar and

  12. Electron Energy Loss Spectroscopy imaging of surface plasmons at the nanometer scale

    International Nuclear Information System (INIS)

    Colliex, Christian; Kociak, Mathieu; Stéphan, Odile

    2016-01-01

    Since their first realization, electron microscopes have demonstrated their unique ability to map with highest spatial resolution (sub-atomic in most recent instruments) the position of atoms as a consequence of the strong scattering of the incident high energy electrons by the nuclei of the material under investigation. When interacting with the electron clouds either on atomic orbitals or delocalized over the specimen, the associated energy transfer, measured and analyzed as an energy loss (Electron Energy Loss Spectroscopy) gives access to analytical properties (atom identification, electron states symmetry and localization). In the moderate energy-loss domain (corresponding to an optical spectral domain from the infrared (IR) to the rather far ultra violet (UV), EELS spectra exhibit characteristic collective excitations of the rather-free electron gas, known as plasmons. Boundary conditions, such as surfaces and/or interfaces between metallic and dielectric media, generate localized surface charge oscillations, surface plasmons (SP), which are associated with confined electric fields. This domain of research has been extraordinarily revived over the past few years as a consequence of the burst of interest for structures and devices guiding, enhancing and controlling light at the sub-wavelength scale. The present review focuses on the study of these surface plasmons with an electron microscopy-based approach which associates spectroscopy and mapping at the level of a single and well-defined nano-object, typically at the nanometer scale i.e. much improved with respect to standard, and even near-field, optical techniques. After calling to mind some early studies, we will briefly mention a few basic aspects of the required instrumentation and associated theoretical tools to interpret the very rich data sets recorded with the latest generation of (Scanning)TEM microscopes. The following paragraphs will review in more detail the results obtained on simple planar and

  13. Geometric Scaling in New Combined Hadron-Electron Ring Accelerator Data

    International Nuclear Information System (INIS)

    Zhou Xiao-Jiao; Qi Lian; Kang Lin; Xiang Wen-Chang; Zhou Dai-Cui

    2014-01-01

    We study the geometric scaling in the new combined data of the hadron-electron ring accelerator by using the Golec-Biernat—Wüsthoff model. It is found that the description of the data is improved once the high accurate data are used to determine the model parameters. The value of x 0 extracted from the fit is larger than the one from the previous study, which indicates a larger saturation scale in the new combined data. This makes more data located in the saturation region, and our approach is more reliable. This study lets the saturation model confront such high precision new combined data, and tests geometric scaling with those data. We demonstrate that the data lie on the same curve, which shows the geometric scaling in the new combined data. This outcome seems to support that the gluon saturation would be a relevant mechanism to dominate the parton evolution process in deep inelastic scattering, due to the fact that the geometric scaling results from the gluon saturation mechanism

  14. The measurement of the total electron content applied to the observation of medium scale gravity wave

    International Nuclear Information System (INIS)

    Bertel, L.; Bertin, F.; Testud, J.

    1976-01-01

    The interpretation of the measurements of the integrated electron content in terms of gravity wave requires (1) a gravity wave model at thermospheric altitudes; (2) a gravity wave-ionization interaction model in the F-region of the ionosphere; and (3) a computing program for the resulting perturbation on the integrated electron content between the satellite and the earth station used. The gravity wave model considered in this paper takes into account the dissipative effects (viscosity, thermal conduction) which become very importanr above 250 km altitude and the effect of the base wind which is capable of affecting deeply the propagation of the waves of medium scale. Starting with this model, the domains of frequencies and the wavelength of atmospheric waves which may exist in the upper atmosphere are considered. The interaction of such waves and the ionization is examined. The theoretical results give information particularly on the selectivity of the ionospheric response to the wave passage. The deduced selectivity of the models appears to be smaller than that given by other authors who used simplified gravity wave models. The method for computing the perturbation of the of the integrated electron content introduced by the wave passage is given for a geostationary satellite. Computational results are presented for application to the case of medium scale gravity waves. (author)

  15. Static and Dynamic Electron Microscopy Investigations at the Atomic and Ultrafast Scales

    Science.gov (United States)

    Suri, Pranav Kumar

    Advancements in the electron microscopy capabilities - aberration-corrected imaging, monochromatic spectroscopy, direct-electron detectors - have enabled routine visualization of atomic-scale processes with millisecond temporal resolutions in this decade. This, combined with progress in the transmission electron microscopy (TEM) specimen holder technology and nanofabrication techniques, allows comprehensive experiments on a wide range of materials in various phases via in situ methods. The development of ultrafast (sub-nanosecond) time-resolved TEM with ultrafast electron microscopy (UEM) has further pushed the envelope of in situ TEM to sub-nanosecond temporal resolution while maintaining sub-nanometer spatial resolution. A plethora of materials phenomena - including electron-phonon coupling, phonon transport, first-order phase transitions, bond rotation, plasmon dynamics, melting, and dopant atoms arrangement - are not yet clearly understood and could be benefitted with the current in situ TEM capabilities having atomic-level and ultrafast precision. Better understanding of these phenomena and intrinsic material dynamics (e.g. how phonons propagate in a material, what time-scales are involved in a first-order phase transition, how fast a material melts, where dopant atoms sit in a crystal) in new-generation and technologically important materials (e.g. two-dimensional layered materials, semiconductor and magnetic devices, rare-earth-element-free permanent magnets, unconventional superconductors) could bring a paradigm shift in their electronic, structural, magnetic, thermal and optical applications. Present research efforts, employing cutting-edge static and dynamic in situ electron microscopy resources at the University of Minnesota, are directed towards understanding the atomic-scale crystallographic structural transition and phonon transport in an iron-pnictide parent compound LaFeAsO, studying the mechanical stability of fast moving hard-drive heads in heat

  16. Tailoring the graphene/silicon carbide interface for monolithic wafer-scale electronics.

    Science.gov (United States)

    Hertel, S; Waldmann, D; Jobst, J; Albert, A; Albrecht, M; Reshanov, S; Schöner, A; Krieger, M; Weber, H B

    2012-07-17

    Graphene is an outstanding electronic material, predicted to have a role in post-silicon electronics. However, owing to the absence of an electronic bandgap, graphene switching devices with high on/off ratio are still lacking. Here in the search for a comprehensive concept for wafer-scale graphene electronics, we present a monolithic transistor that uses the entire material system epitaxial graphene on silicon carbide (0001). This system consists of the graphene layer with its vanishing energy gap, the underlying semiconductor and their common interface. The graphene/semiconductor interfaces are tailor-made for ohmic as well as for Schottky contacts side-by-side on the same chip. We demonstrate normally on and normally off operation of a single transistor with on/off ratios exceeding 10(4) and no damping at megahertz frequencies. In its simplest realization, the fabrication process requires only one lithography step to build transistors, diodes, resistors and eventually integrated circuits without the need of metallic interconnects.

  17. Laboratory scale electron beam system for treatment of flue gases from diesel combustion

    International Nuclear Information System (INIS)

    Siti Aiasah Hashim; Khairul Zaman Mohd Dahlan; Khomsaton Abu Bakar; Ayub Muhammad

    2004-01-01

    Laboratory scale test rig to treat simulated flue gas using electron beam technology was installed at the Alurtron EB-Irradiation Center, MINT. The experiment test rig was proposed as a result of feasibility studies conducted jointly by IAEA, MINT and TNB Research in 1997. The test rig system consists of several components, among other, diesel generator sets, pipe ducts, spray cooler, ammonia dosage system, irradiation vessel, bag filter and gas analyzers. The installation was completed and commissioned in October 2001. results from the commissioning test runs and subsequent experimental work showed that the efficiency of flue gas treatment is high. It was proven that electron beam technology might be applied in the treatment of air pollutants. This paper describes the design and work function of the individual major components as well as the full system function. Results from the initial experimental works are also presented. (Author)

  18. A study on depth-scaling of plastic phantom in electron beam dosimetry

    International Nuclear Information System (INIS)

    Kojima, T.; Saitoh, H.; Kawachi, T.; Katayose, T.; Myojyoyama, A.

    2005-01-01

    In recommendations of several standard dosimetry, water is defined as the reference medium, however, the water substitute plastic phantoms are highly discouraged. Nevertheless, in the case of accurate chamber positioning in water is not possible, or no waterproof chamber is available, their use is permitted at beam qualities R 50 2 (E 0 pl obtained from a ratio of electron average penetration depth; z av , half value depth ratio; (R 50 ) w,m from Monte Carlo dose calculation and that from measurements, are compared each other. As a result, there are slight differences in depth-scaling factor between obtained from simulation results and from measurements. These results indicate that c pl has to be studied more detail for the sake of precise electron dosimetry in plastic phantoms. (author)

  19. Simulations of nanocrystals under pressure: Combining electronic enthalpy and linear-scaling density-functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Corsini, Niccolò R. C., E-mail: niccolo.corsini@imperial.ac.uk; Greco, Andrea; Haynes, Peter D. [Department of Physics and Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Hine, Nicholas D. M. [Department of Physics and Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Cavendish Laboratory, J. J. Thompson Avenue, Cambridge CB3 0HE (United Kingdom); Molteni, Carla [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2013-08-28

    We present an implementation in a linear-scaling density-functional theory code of an electronic enthalpy method, which has been found to be natural and efficient for the ab initio calculation of finite systems under hydrostatic pressure. Based on a definition of the system volume as that enclosed within an electronic density isosurface [M. Cococcioni, F. Mauri, G. Ceder, and N. Marzari, Phys. Rev. Lett.94, 145501 (2005)], it supports both geometry optimizations and molecular dynamics simulations. We introduce an approach for calibrating the parameters defining the volume in the context of geometry optimizations and discuss their significance. Results in good agreement with simulations using explicit solvents are obtained, validating our approach. Size-dependent pressure-induced structural transformations and variations in the energy gap of hydrogenated silicon nanocrystals are investigated, including one comparable in size to recent experiments. A detailed analysis of the polyamorphic transformations reveals three types of amorphous structures and their persistence on depressurization is assessed.

  20. Decay of MHD-scale Kelvin-Helmholtz vortices mediated by parasitic electron dynamics

    International Nuclear Information System (INIS)

    Nakamura, T.K.M.; Hayashi, D.; Fujimoto, M.; Shinohara, I.

    2004-01-01

    We have simulated nonlinear development of MHD-scale Kelvin-Helmholtz (KH) vortices by a two-dimensional two-fluid system including finite electron inertial effects. In the presence of moderate density jump across a shear layer, in striking contrast to MHD results, MHD KH vortices are found to decay by the time one eddy turnover is completed. The decay is mediated by smaller vortices that appear within the parent vortex and stays effective even when the shear layer width is made larger. It is shown that the smaller vortices are basically of MHD nature while the seeding for these is achieved by the electron inertial effect. Application of the results to the magnetotail boundary layer is discussed

  1. Measurements of Electron Transport in Foils Irradiated with a Picosecond Time Scale Laser Pulse

    International Nuclear Information System (INIS)

    Brown, C. R. D.; Hoarty, D. J.; James, S. F.; Swatton, D.; Hughes, S. J.; Morton, J. W.; Guymer, T. M.; Hill, M. P.; Chapman, D. A.; Andrew, J. E.; Comley, A. J.; Shepherd, R.; Dunn, J.; Chen, H.; Schneider, M.; Brown, G.; Beiersdorfer, P.; Emig, J.

    2011-01-01

    The heating of solid foils by a picosecond time scale laser pulse has been studied by using x-ray emission spectroscopy. The target material was plastic foil with a buried layer of a spectroscopic tracer material. The laser pulse length was either 0.5 or 2 ps, which resulted in a laser irradiance that varied over the range 10 16 -10 19 W/cm 2 . Time-resolved measurements of the buried layer emission spectra using an ultrafast x-ray streak camera were used to infer the density and temperature conditions as a function of laser parameters and depth of the buried layer. Comparison of the data to different models of electron transport showed that they are consistent with a model of electron transport that predicts the bulk of the target heating is due to return currents.

  2. Cross sections and oscillator strengths for electron-impact excitation of electronic states in polyatomic molecules. Application examples of the BEf- scaling model in optically-allowed transitions

    International Nuclear Information System (INIS)

    Kato, H.; Kawahara, H.; Hoshino, M.

    2009-12-01

    Integral cross sections for optically allowed electronic-state excitations by electron impact, are reviewed for polyatomic molecules by applying the Binary-Encounter-Bethe (BEB) scaling model. Following the context of the present review, the scaling model originally proposed by Yong-Ki Kim to determine electron-impact cross sections for ionization of atoms and molecules is also summarized briefly for its wide range of applications [Electron-Impact Cross Section Database, NIST, Y.-K. Kim]. The present report not only focuses on the need for the cross-section data, but also elucidates the verification of the scaling model in the general application for atoms and molecules. Since this report is for a data base, it is summarized for data base users by citing (copying) the descriptions in the original papers and the references within those papers in the style of a textbook. (author)

  3. Electronic transport mechanisms in scaled gate-all-around silicon nanowire transistor arrays

    Energy Technology Data Exchange (ETDEWEB)

    Clément, N., E-mail: nicolas.clement@iemn.univ-lille1.fr, E-mail: guilhem.larrieu@laas.fr; Han, X. L. [Institute of Electronics, Microelectronics and Nanotechnology, CNRS, Avenue Poincaré, 59652 Villeneuve d' Ascq (France); Larrieu, G., E-mail: nicolas.clement@iemn.univ-lille1.fr, E-mail: guilhem.larrieu@laas.fr [Laboratory for Analysis and Architecture of Systems (LAAS), CNRS, Universite de Toulouse, 7 Avenue Colonel Roche, 31077 Toulouse (France)

    2013-12-23

    Low-frequency noise is used to study the electronic transport in arrays of 14 nm gate length vertical silicon nanowire devices. We demonstrate that, even at such scaling, the electrostatic control of the gate-all-around is sufficient in the sub-threshold voltage region to confine charges in the heart of the wire, and the extremely low noise level is comparable to that of high quality epitaxial layers. Although contact noise can already be a source of poor transistor operation above threshold voltage for few nanowires, nanowire parallelization drastically reduces its impact.

  4. Electron-helium scattering in the S-wave model using exterior complex scaling

    International Nuclear Information System (INIS)

    Horner, Daniel A.; McCurdy, C. William; Rescigno, Thomas N.

    2004-01-01

    Electron-impact excitation and ionization of helium is studied in the S-wave model. The problem is treated in full dimensionality using a time-dependent formulation of the exterior complex scaling method that does not involve the solution of large linear systems of equations. We discuss the steps that must be taken to compute stable ionization amplitudes. We present total excitation, total ionization and single differential cross sections from the ground and n=2 excited states and compare our results with those obtained by others using a frozen-core model

  5. Some consequences of a scale-breaking model in electron and neutrino deep inelastic scattering

    International Nuclear Information System (INIS)

    Fernandez Pacheco, A.; Grifols, J.A.; Schmidt, I.A.

    1978-01-01

    Electron and neutrino deep inelastic processes, extending a simple parton model explanation of the approach to scaling observed in electroproduction at large x are analyzed. The model is successful in fitting the present experimental data without any explicit effects from asymptotic freedom or new quarks. This model has a large q 2 behaviour which is quite different from that expected in asymptotic freedom (AF) theories and comparisons to data can be used to sharpen any experimental demonstration of AF effects. Of course, the model is consistent with AF and both effects could be present

  6. Flow visualization and velocity measurement in a small-scale open channel using an electron microscope

    International Nuclear Information System (INIS)

    Yasuda, K; Sogo, M; Iwamoto, Y

    2013-01-01

    The present note describes a method for use in conjunction with a scanning electron microscope (SEM) that has been developed to visualize a liquid flow under a high-level vacuum and to measure a velocity field in a small-scale flow through an open channel. In general, liquid cannot be observed via a SEM, because liquid evaporates under the high-vacuum environment of the SEM. As such, ionic liquid and room temperature molten salt having a vapor pressure of nearly zero is used in the present study. We use ionic liquid containing Au-coated tracer particles to visualize a small-scale flow under a SEM. Furthermore, the velocity distribution in the open channel is obtained by particle tracking velocimetry measurement and a parabolic profile is confirmed. (technical design note)

  7. Tokamak electron heat transport by direct numerical simulation of small scale turbulence

    International Nuclear Information System (INIS)

    Labit, B.

    2002-10-01

    In a fusion machine, understanding plasma turbulence, which causes a degradation of the measured energy confinement time, would constitute a major progress in this field. In tokamaks, the measured ion and electron thermal conductivities are of comparable magnitude. The possible sources of turbulence are the temperature and density gradients occurring in a fusion plasma. Whereas the heat losses in the ion channel are reasonably well understood, the origin of the electron losses is more uncertain. In addition to the radial velocity associated to the fluctuations of the electric field, electrons are more affected than ions by the magnetic field fluctuations. In experiments, the confinement time can be conveniently expressed in terms of dimensionless parameters. Although still somewhat too imprecise, these scaling laws exhibit strong dependencies on the normalized pressure β or the normalized Larmor radius, ρ * . The present thesis assesses whether a tridimensional, electromagnetic, nonlinear fluid model of plasma turbulence driven by a specific instability can reproduce the dependence of the experimental electron heat losses on the dimensionless parameters β and ρ * . The investigated interchange instability is the Electron Temperature Gradient driven one (ETG). The model is built by using the set of Braginskii equations. The developed simulation code is global in the sense that a fixed heat flux is imposed at the inner boundary, leaving the gradients free to evolve. From the nonlinear simulations, we have put in light three characteristics for the ETG turbulence: the turbulent transport is essentially electrostatic; the potential and pressure fluctuations form radially elongated cells called streamers; the transport level is very low compared to the experimental values. The thermal transport dependence study has shown a very small role of the normalized pressure, which is in contradiction with the Ohkama's formula. On the other hand, the crucial role of the

  8. Investigation of industrial-scale carbon dioxide reduction using pulsed electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, G. M.; Apruzese, J. P.; Petrova, Tz. B.; Wolford, M. F. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375-5346 (United States)

    2016-03-14

    Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO{sub 2} concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO{sub 2} is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO{sub 2} and energy cost for breaking a CO{sub 2} molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N{sub 2}, 6% O{sub 2}, and 12% CO{sub 2}, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO{sub 2} molecules, beam energy density deposition on the order of 20 J/cm{sup 3} is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO{sub 2} and 10% CH{sub 4} at beam energy density deposition of 4.2 J/cm{sup 3}, accumulated over 43 shots in a 20 min interval, reduced the CO{sub 2} concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO{sub 2}, 11.5% CH{sub 4}, and balance of Ar, reduced the CO{sub 2} concentration to below 11% with energy deposition 0.71 J/cm{sup 3}, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO{sub 2} reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO{sub 2} with pulsed electron beams are also explored, yielding new possible avenues of research.

  9. Electronic structure and aromaticity of large-scale hexagonal graphene nanoflakes

    International Nuclear Information System (INIS)

    Hu, Wei; Yang, Chao; Lin, Lin; Yang, Jinlong

    2014-01-01

    With the help of the recently developed SIESTA-pole (Spanish Initiative for Electronic Simulations with Thousands of Atoms) - PEXSI (pole expansion and selected inversion) method [L. Lin, A. García, G. Huhs, and C. Yang, J. Phys.: Condens. Matter 26, 305503 (2014)], we perform Kohn-Sham density functional theory calculations to study the stability and electronic structure of hydrogen passivated hexagonal graphene nanoflakes (GNFs) with up to 11 700 atoms. We find the electronic properties of GNFs, including their cohesive energy, edge formation energy, highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap, edge states, and aromaticity, depend sensitively on the type of edges (armchair graphene nanoflakes (ACGNFs) and zigzag graphene nanoflakes (ZZGNFs)), size and the number of electrons. We observe that, due to the edge-induced strain effect in ACGNFs, large-scale ACGNFs’ edge formation energy decreases as their size increases. This trend does not hold for ZZGNFs due to the presence of many edge states in ZZGNFs. We find that the energy gaps E g of GNFs all decay with respect to 1/L, where L is the size of the GNF, in a linear fashion. But as their size increases, ZZGNFs exhibit more localized edge states. We believe the presence of these states makes their gap decrease more rapidly. In particular, when L is larger than 6.40 nm, we find that ZZGNFs exhibit metallic characteristics. Furthermore, we find that the aromatic structures of GNFs appear to depend only on whether the system has 4N or 4N + 2 electrons, where N is an integer

  10. Electronic structure and aromaticity of large-scale hexagonal graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wei, E-mail: whu@lbl.gov, E-mail: linlin@lbl.gov, E-mail: cyang@lbl.gov, E-mail: jlyang@ustc.edu.cn; Yang, Chao, E-mail: whu@lbl.gov, E-mail: linlin@lbl.gov, E-mail: cyang@lbl.gov, E-mail: jlyang@ustc.edu.cn [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lin, Lin, E-mail: whu@lbl.gov, E-mail: linlin@lbl.gov, E-mail: cyang@lbl.gov, E-mail: jlyang@ustc.edu.cn [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Mathematics, University of California, Berkeley, California 94720 (United States); Yang, Jinlong, E-mail: whu@lbl.gov, E-mail: linlin@lbl.gov, E-mail: cyang@lbl.gov, E-mail: jlyang@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-12-07

    With the help of the recently developed SIESTA-pole (Spanish Initiative for Electronic Simulations with Thousands of Atoms) - PEXSI (pole expansion and selected inversion) method [L. Lin, A. García, G. Huhs, and C. Yang, J. Phys.: Condens. Matter 26, 305503 (2014)], we perform Kohn-Sham density functional theory calculations to study the stability and electronic structure of hydrogen passivated hexagonal graphene nanoflakes (GNFs) with up to 11 700 atoms. We find the electronic properties of GNFs, including their cohesive energy, edge formation energy, highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap, edge states, and aromaticity, depend sensitively on the type of edges (armchair graphene nanoflakes (ACGNFs) and zigzag graphene nanoflakes (ZZGNFs)), size and the number of electrons. We observe that, due to the edge-induced strain effect in ACGNFs, large-scale ACGNFs’ edge formation energy decreases as their size increases. This trend does not hold for ZZGNFs due to the presence of many edge states in ZZGNFs. We find that the energy gaps E{sub g} of GNFs all decay with respect to 1/L, where L is the size of the GNF, in a linear fashion. But as their size increases, ZZGNFs exhibit more localized edge states. We believe the presence of these states makes their gap decrease more rapidly. In particular, when L is larger than 6.40 nm, we find that ZZGNFs exhibit metallic characteristics. Furthermore, we find that the aromatic structures of GNFs appear to depend only on whether the system has 4N or 4N + 2 electrons, where N is an integer.

  11. Electronic structure and aromaticity of large-scale hexagonal graphene nanoflakes.

    Science.gov (United States)

    Hu, Wei; Lin, Lin; Yang, Chao; Yang, Jinlong

    2014-12-07

    With the help of the recently developed SIESTA-pole (Spanish Initiative for Electronic Simulations with Thousands of Atoms) - PEXSI (pole expansion and selected inversion) method [L. Lin, A. García, G. Huhs, and C. Yang, J. Phys.: Condens. Matter 26, 305503 (2014)], we perform Kohn-Sham density functional theory calculations to study the stability and electronic structure of hydrogen passivated hexagonal graphene nanoflakes (GNFs) with up to 11,700 atoms. We find the electronic properties of GNFs, including their cohesive energy, edge formation energy, highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap, edge states, and aromaticity, depend sensitively on the type of edges (armchair graphene nanoflakes (ACGNFs) and zigzag graphene nanoflakes (ZZGNFs)), size and the number of electrons. We observe that, due to the edge-induced strain effect in ACGNFs, large-scale ACGNFs' edge formation energy decreases as their size increases. This trend does not hold for ZZGNFs due to the presence of many edge states in ZZGNFs. We find that the energy gaps E(g) of GNFs all decay with respect to 1/L, where L is the size of the GNF, in a linear fashion. But as their size increases, ZZGNFs exhibit more localized edge states. We believe the presence of these states makes their gap decrease more rapidly. In particular, when L is larger than 6.40 nm, we find that ZZGNFs exhibit metallic characteristics. Furthermore, we find that the aromatic structures of GNFs appear to depend only on whether the system has 4N or 4N + 2 electrons, where N is an integer.

  12. Transmission electron microscopical study of teenage crown dentin on the nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Panfilov, Peter, E-mail: peter.panfilov@urfu.ru [Ural Federal University, Ekaterinburg (Russian Federation); Kabanova, Anna [Ural Federal University, Ekaterinburg (Russian Federation); Guo, Jinming; Zhang, Zaoli [Erich Schmid Institute for Materials Science, Austrian Academy of Sciences, Leoben (Austria)

    2017-02-01

    Statement of significance: This is the first transmission electron microscopic study of teenage crown dentin on the nanometer scale. Samples for TEM were prepared by mechanical thinning and chemical polishing that allowed obtaining the electron transparent foils. It was firstly shown that human dentin possesses the layered morphology: the layers are oriented normally to the main axis of a tooth and have the thickness of ~ 50 nm. HA inorganic phase of teenage crown dentin is in the amorphous state. The cellular structure, which was formed from collagen fibers (diameter is ~ 5 nm), are observed near DEJ region in teenage dentin, whereas bioorganic phase of teenage crown dentin near the pulp camera does not contain the collagen fibers. Cracks in dentin thin foils have sharp tips, but big angles of opening (~ 30{sup °}) with plastic zone ahead crack tip. It means that young crown human dentin exhibits ductile or viscous-elastic fracture behavior on the nanometer scale. - Highlights: • Dentin has layered morphology. • Mineral component of dentin is in amorphous state. • Collagen fibers form cellular structure in dentin. • Cracks in dentin behave by elastic-plastic manner.

  13. Iteratively-coupled propagating exterior complex scaling method for electron-hydrogen collisions

    International Nuclear Information System (INIS)

    Bartlett, Philip L; Stelbovics, Andris T; Bray, Igor

    2004-01-01

    A newly-derived iterative coupling procedure for the propagating exterior complex scaling (PECS) method is used to efficiently calculate the electron-impact wavefunctions for atomic hydrogen. An overview of this method is given along with methods for extracting scattering cross sections. Differential scattering cross sections at 30 eV are presented for the electron-impact excitation to the n = 1, 2, 3 and 4 final states, for both PECS and convergent close coupling (CCC), which are in excellent agreement with each other and with experiment. PECS results are presented at 27.2 eV and 30 eV for symmetric and asymmetric energy-sharing triple differential cross sections, which are in excellent agreement with CCC and exterior complex scaling calculations, and with experimental data. At these intermediate energies, the efficiency of the PECS method with iterative coupling has allowed highly accurate partial-wave solutions of the full Schroedinger equation, for L ≤ 50 and a large number of coupled angular momentum states, to be obtained with minimal computing resources. (letter to the editor)

  14. Transmission electron microscopical study of teenage crown dentin on the nanometer scale

    International Nuclear Information System (INIS)

    Panfilov, Peter; Kabanova, Anna; Guo, Jinming; Zhang, Zaoli

    2017-01-01

    Statement of significance: This is the first transmission electron microscopic study of teenage crown dentin on the nanometer scale. Samples for TEM were prepared by mechanical thinning and chemical polishing that allowed obtaining the electron transparent foils. It was firstly shown that human dentin possesses the layered morphology: the layers are oriented normally to the main axis of a tooth and have the thickness of ~ 50 nm. HA inorganic phase of teenage crown dentin is in the amorphous state. The cellular structure, which was formed from collagen fibers (diameter is ~ 5 nm), are observed near DEJ region in teenage dentin, whereas bioorganic phase of teenage crown dentin near the pulp camera does not contain the collagen fibers. Cracks in dentin thin foils have sharp tips, but big angles of opening (~ 30 ° ) with plastic zone ahead crack tip. It means that young crown human dentin exhibits ductile or viscous-elastic fracture behavior on the nanometer scale. - Highlights: • Dentin has layered morphology. • Mineral component of dentin is in amorphous state. • Collagen fibers form cellular structure in dentin. • Cracks in dentin behave by elastic-plastic manner.

  15. Epitaxial Lift-Off of Centimeter-Scaled Spinel Ferrite Oxide Thin Films for Flexible Electronics.

    Science.gov (United States)

    Shen, Lvkang; Wu, Liang; Sheng, Quan; Ma, Chunrui; Zhang, Yong; Lu, Lu; Ma, Ji; Ma, Jing; Bian, Jihong; Yang, Yaodong; Chen, Aiping; Lu, Xiaoli; Liu, Ming; Wang, Hong; Jia, Chun-Lin

    2017-09-01

    Mechanical flexibility of electronic devices has attracted much attention from research due to the great demand in practical applications and rich commercial value. Integration of functional oxide materials in flexible polymer materials has proven an effective way to achieve flexibility of functional electronic devices. However, the chemical and mechanical incompatibilities at the interfaces of dissimilar materials make it still a big challenge to synthesize high-quality single-crystalline oxide thin film directly on flexible polymer substrates. This study reports an improved method that is employed to successfully transfer a centimeter-scaled single-crystalline LiFe 5 O 8 thin film on polyimide substrate. Structural characterizations show that the transferred films have essentially no difference in comparison with the as-grown films with respect to the microstructure. In particular, the transferred LiFe 5 O 8 films exhibit excellent magnetic properties under various mechanical bending statuses and show excellent fatigue properties during the bending cycle tests. These results demonstrate that the improved transfer method provides an effective way to compose single-crystalline functional oxide thin films onto flexible substrates for applications in flexible and wearable electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Collisionless magnetic reconnection in large-scale electron-positron plasmas

    International Nuclear Information System (INIS)

    Daughton, William; Karimabadi, Homa

    2007-01-01

    One of the most fundamental questions in reconnection physics is how the dynamical evolution will scale to macroscopic systems of physical relevance. This issue is examined for electron-positron plasmas using two-dimensional fully kinetic simulations with both open and periodic boundary conditions. The resulting evolution is complex and highly dynamic throughout the entire duration. The initial phase is distinguished by the coalescence of tearing islands to larger scale while the later phase is marked by the expansion of diffusion regions into elongated current layers that are intrinsically unstable to plasmoid generation. It appears that the repeated formation and ejection of plasmoids plays a key role in controlling the average structure of a diffusion region and preventing the further elongation of the layer. The reconnection rate is modulated in time as the current layers expand and new plasmoids are formed. Although the specific details of this evolution are affected by the boundary and initial conditions, the time averaged reconnection rate remains fast and is remarkably insensitive to the system size for sufficiently large systems. This dynamic scenario offers an alternative explanation for fast reconnection in large-scale systems

  17. Reaching the unreached.

    Science.gov (United States)

    Ariyaratne, A T

    1989-01-01

    Embodied in the child survival revolution are ideological, methodological, and organizational innovations aimed at radical change in the condition of the world's children as rapidly as possible. In countries such as Sri Lanka, child survival and health for all by the year 2000 often seem to be impossible goals, given the tumultuous socioeconomic and political conditions. In Sri Lanka, the quality of life has been eroded, not enhanced, by the importation of Western technology and managerial capitalism and the destruction of indigenous processes. The chaos and violence that have been brought into the country have made it difficult to reach the poor children, women, and refugees in rural areas with primary health care interventions. Sri Lanka's unreachable--the decision making elites--have blocked access to the unreached--the urban and rural poor. If governments are to reach the unreached, they must remove the obstacles to a people-centered, community development process. It is the people themselves, and the institutions of their creation, that can reach the children amidst them in greatest need. To achieve this task, local communities must be provided with basic human rights, the power to make decisions that affect their lives, necessary resources, and appropriate technologies. Nongovernmental organizations can play a crucial role as bridges between the unreached and the unreachable by promoting community empowerment, aiding in the formation of networks of community organizations, and establishing linkages with government programs. If the ruling elites in developing countries can be persuaded to accommodate the needs and aspirations of those who, to date, have been excluded from the development process, the child survival revolution can be a nonviolent one.

  18. Solar Hydrogen Reaching Maturity

    Directory of Open Access Journals (Sweden)

    Rongé Jan

    2015-09-01

    Full Text Available Increasingly vast research efforts are devoted to the development of materials and processes for solar hydrogen production by light-driven dissociation of water into oxygen and hydrogen. Storage of solar energy in chemical bonds resolves the issues associated with the intermittent nature of sunlight, by decoupling energy generation and consumption. This paper investigates recent advances and prospects in solar hydrogen processes that are reaching market readiness. Future energy scenarios involving solar hydrogen are proposed and a case is made for systems producing hydrogen from water vapor present in air, supported by advanced modeling.

  19. Development of the simulation package 'ELSES' for extra-large-scale electronic structure calculation

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, T [Department of Applied Mathematics and Physics, Tottori University, Tottori 680-8550 (Japan); Fujiwara, T [Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (CREST-JST) (Japan)

    2009-02-11

    An early-stage version of the simulation package 'ELSES' (extra-large-scale electronic structure calculation) is developed for simulating the electronic structure and dynamics of large systems, particularly nanometer-scale and ten-nanometer-scale systems (see www.elses.jp). Input and output files are written in the extensible markup language (XML) style for general users. Related pre-/post-simulation tools are also available. A practical workflow and an example are described. A test calculation for the GaAs bulk system is shown, to demonstrate that the present code can handle systems with more than one atom species. Several future aspects are also discussed.

  20. Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER

    Science.gov (United States)

    Grierson, B. A.; Staebler, G. M.; Solomon, W. M.; McKee, G. R.; Holland, C.; Austin, M.; Marinoni, A.; Schmitz, L.; Pinsker, R. I.; DIII-D Team

    2018-02-01

    Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changes in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. For a range of E × B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.

  1. Pilot-scale test for electron beam purification of flue gas from coal-combustion boiler

    International Nuclear Information System (INIS)

    Namba, Hideki; Tokunaga, Okihiro; Hashimoto, Shoji; Doi, Yoshitaka; Aoki, Shinji; Izutsu, Masahiro

    1995-01-01

    A pilot-scale test for electron beam treatment of flue gas (12,000m 3 N/hr) from coal-fired boiler was conducted by Japan Atomic Energy Research Institute, Chubu Electric Power Company and Ebara Corporation, in the site of Shin-Nagoya Thermal Power Plant in Nagoya, Japan. During 14 months operation, it was proved that the method is possible to remove SO 2 and NO x simultaneously in wide concentration range of SO 2 (250-2,000ppm) and NO x (140-240ppm) with higher efficiency than the conventional methods, with appropriate operation conditions (dose, temperature etc.). The pilot plant was easily operated with well controllability and durability, and was operated for long period of time without serious problems. The byproduct, ammonium sulfate and ammonium nitrate, produced by the treatment was proved to be a nitrogenous fertilizer with excellent quality. (author)

  2. In-medium scaling law and electron scattering from high-spin states in 208Pb

    International Nuclear Information System (INIS)

    Arias de Saavedra, F.; Lallena, A.M.

    1994-01-01

    The effects of the environment modifications in the structure of the low-lying high-spin states of 208 Pb are studied by analyzing how the in-medium scaling law works on the excitation energies, wave functions, and electron scattering form factors corresponding to these states. It is shown that the consideration of f π * in addition to the effective ρ-meson mass does not affect too much most of the states analyzed. However, some of them appear to be extremely sensitive to its inclusion in the residual nucleon-nucleon interaction. As a result, a value of m ρ * /m ρ ∼f π * /f π ∼0.91 gives a good description of the (e,e') form factors of these particular states without any quenching factor. This value is in agreement with the one found for 48 Ca in a similar analysis performed in a previous work

  3. MMS Observations of Electron-Scale Filamentary Currents in the Reconnection Exhaust and Near the X Line

    Science.gov (United States)

    Phan, T. D.; Eastwood, J. P.; Cassak, P. A.; Oieroset, M.; Gosling, J. T.; Gershman, D. J.; Mozer, F. S.; Shay, M. A.; Fujimoto, M.; Daughton, W.; hide

    2016-01-01

    We report Magnetospheric Multiscale observations of macroscopic and electron-scale current layers in asymmetric reconnection. By intercomparing plasma, magnetic, and electric field data at multiple crossings of a reconnecting magnetopause on 22 October 2015, when the average interspacecraft separation was approximately 10 km, we demonstrate that the ion and electron moments are sufficiently accurate to provide reliable current density measurements at 30ms cadence. These measurements, which resolve current layers narrower than the interspacecraft separation, reveal electron-scale filamentary Hall currents and electron vorticity within the reconnection exhaust far downstream of the X line and even in the magnetosheath. Slightly downstream of the X line, intense (up to 3 µA/m2) electron currents, a super-Alfvenic outflowing electron jet, and nongyrotropic crescent shape electron distributions were observed deep inside the ion-scale magnetopause current sheet and embedded in the ion diffusion region. These characteristics are similar to those attributed to the electron dissipation/diffusion region around the X line.

  4. The suitability of gray-scale electronic readers for dermatology journals.

    Science.gov (United States)

    Choi, Jae Eun; Kim, Dai Hyun; Seo, Soo Hong; Kye, Young Chul; Ahn, Hyo Hyun

    2014-12-01

    The rapid development of information and communication technology has replaced traditional books by electronic versions. Most print dermatology journals have been replaced with electronic journals (e-journals), which are readily used by clinicians and medical students. The objectives of this study were to determine whether e-readers are appropriate for reading dermatology journals, to conduct an attitude study of both medical personnel and students, and to find a way of improving e-book use in the field of dermatology. All articles in the Korean Journal of Dermatology published from January 2010 to December 2010 were utilized in this study. Dermatology house officers, student trainees in their fourth year of medical school, and interns at Korea University Medical Center participated in the study. After reading the articles with Kindle 2, their impressions and evaluations were recorded using a questionnaire with a 5-point Likert scale. The results demonstrated that gray-scale e-readers might not be suitable for reading dermatology journals, especially for case reports compared to the original articles. Only three of the thirty-one respondents preferred e-readers to printed papers. The most common suggestions from respondents to encourage usage of e-books in the field of dermatology were the introduction of a color display, followed by the use of a touch screen system, a cheaper price, and ready-to-print capabilities. In conclusion, our study demonstrated that current e-readers might not be suitable for reading dermatology journals. However, they may be utilized in selected situations according to the type and topic of the papers.

  5. Energy distribution of relativistic electrons in the kiloparsec scale jet of M 87 with Chandra

    Science.gov (United States)

    Sun, Xiao-Na; Yang, Rui-Zhi; Rieger, Frank M.; Liu, Ruo-Yu; Aharonian, Felix

    2018-05-01

    The X-ray emission from the jets in active galactic nuclei (AGN) carries important information on the distributions of relativistic electrons and magnetic fields on large scales. We reanalysed archival Chandra observations on the jet of M 87 from 2000 to 2016 with a total exposure of 1460 kiloseconds to explore the X-ray emission characteristics along the jet. We investigated the variability behaviours of the nucleus and the inner jet component HST-1, and confirm indications for day-scale X-ray variability in the nucleus contemporaneous to the 2010 high TeV γ-ray state. HST-1 shows a general decline in X-ray flux over the last few years consistent with its synchrotron interpretation. We extracted the X-ray spectra for the nucleus and all knots in the jet, showing that they are compatible with a single power law within the X-ray band. There are indications that the resultant X-ray photon index exhibit a trend, with slight but significant index variations ranging from ≃ 2.2 (e.g. in knot D) to ≃ 2.4-2.6 (in the outer knots F, A, and B). When viewed in a multiwavelength context, a more complex situation can be seen. Fitting the radio to X-ray spectral energy distributions (SEDs) assuming a synchrotron origin, we show that a broken power-law electron spectrum with break energy Eb around 1 (300 μG/B)1/2 TeV allows a satisfactory description of the multiband SEDs for most of the knots. However, in the case of knots B, C, and D we find indications that an additional high-energy component is needed to adequately reproduce the broad-band SEDs. We discuss the implications and suggest that a stratified jet model may account for the differences.

  6. Modeling the Charge Transport in Graphene Nano Ribbon Interfaces for Nano Scale Electronic Devices

    Science.gov (United States)

    Kumar, Ravinder; Engles, Derick

    2015-05-01

    In this research work we have modeled, simulated and compared the electronic charge transport for Metal-Semiconductor-Metal interfaces of Graphene Nano Ribbons (GNR) with different geometries using First-Principle calculations and Non-Equilibrium Green's Function (NEGF) method. We modeled junctions of Armchair GNR strip sandwiched between two Zigzag strips with (Z-A-Z) and Zigzag GNR strip sandwiched between two Armchair strips with (A-Z-A) using semi-empirical Extended Huckle Theory (EHT) within the framework of Non-Equilibrium Green Function (NEGF). I-V characteristics of the interfaces were visualized for various transport parameters. The distinct changes in conductance and I-V curves reported as the Width across layers, Channel length (Central part) was varied at different bias voltages from -1V to 1 V with steps of 0.25 V. From the simulated results we observed that the conductance through A-Z-A graphene junction is in the range of 10-13 Siemens whereas the conductance through Z-A-Z graphene junction is in the range of 10-5 Siemens. These suggested conductance controlled mechanisms for the charge transport in the graphene interfaces with different geometries is important for the design of graphene based nano scale electronic devices like Graphene FETs, Sensors.

  7. Universal scaling relations for the energies of many-electron Hooke atoms

    Science.gov (United States)

    Odriazola, A.; Solanpää, J.; Kylänpää, I.; González, A.; Räsänen, E.

    2017-04-01

    A three-dimensional harmonic oscillator consisting of N ≥2 Coulomb-interacting charged particles, often called a (many-electron) Hooke atom, is a popular model in computational physics for, e.g., semiconductor quantum dots and ultracold ions. Starting from Thomas-Fermi theory, we show that the ground-state energy of such a system satisfies a nontrivial relation: Eg s=ω N4 /3fg s(β N1 /2) , where ω is the oscillator strength, β is the ratio between Coulomb and oscillator characteristic energies, and fg s is a universal function. We perform extensive numerical calculations to verify the applicability of the relation. In addition, we show that the chemical potentials and addition energies also satisfy approximate scaling relations. In all cases, analytic expressions for the universal functions are provided. The results have predictive power in estimating the key ground-state properties of the system in the large-N limit, and can be used in the development of approximative methods in electronic structure theory.

  8. BROOKHAVEN: Proton goal reached

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10 13 protons per pulse (ppp), by accelerating 6.3 x 10 13 ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10 13 ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10 13 ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10 13 ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10 13 ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found

  9. BROOKHAVEN: Proton goal reached

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10{sup 13} protons per pulse (ppp), by accelerating 6.3 x 10{sup 13} ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10{sup 13} ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10{sup 13} ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10{sup 13} ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10{sup 13} ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found.

  10. Development of a scanning tunneling potentiometry system for measurement of electronic transport at short length scales

    Science.gov (United States)

    Rozler, Michael

    It is clear that complete understanding of macroscopic properties of materials is impossible without a thorough knowledge of behavior at the smallest length scales. While the past 25 years have witnessed major advances in a variety of techniques that probe the nanoscale properties of matter, electrical transport measurements -- the heart of condensed matter research -- have lagged behind, never progressing beyond bulk measurements. This thesis describes a scanning tunneling potentiometry (STP) system developed to simultaneously map the transport-related electrochemical potential distribution of a biased sample along with its surface topography, extending electronic transport measurements to the nanoscale. Combining a novel sample biasing technique with a continuous current-nulling feedback scheme pushes the noise performance of the measurement to its fundamental limit - the Johnson noise of the STM tunnel junction. The resulting 130 nV voltage sensitivity allows us to spatially resolve local potentials at scales down to 2 nm, while maintaining atomic scale STM imaging, all at scan sizes of up to 15 microns. A mm-range two-dimensional coarse positioning stage and the ability to operate from liquid helium to room temperature with a fast turn-around time greatly expand the versatility of the instrument. Use of carefully selected model materials, combined with excellent topographic and voltage resolution has allowed us to distinguish measurement artifacts caused by surface roughness from true potentiometric features, a major problem in previous STP measurements. The measurements demonstrate that STP can produce physically meaningful results for homogeneous transport as well as non-uniform conduction dominated by material microstructures. Measurements of several physically interesting materials systems are presented as well, revealing new behaviors at the smallest length sales. The results establish scanning tunneling potentiometry as a useful tool for physics and

  11. Electron critical gradient scale length measurements of ICRF heated L-mode plasmas at Alcator C-Mod tokamak

    Science.gov (United States)

    Houshmandyar, S.; Hatch, D. R.; Horton, C. W.; Liao, K. T.; Phillips, P. E.; Rowan, W. L.; Zhao, B.; Cao, N. M.; Ernst, D. R.; Greenwald, M.; Howard, N. T.; Hubbard, A. E.; Hughes, J. W.; Rice, J. E.

    2018-04-01

    A profile for the critical gradient scale length (Lc) has been measured in L-mode discharges at the Alcator C-Mod tokamak, where electrons were heated by an ion cyclotron range of frequency through minority heating with the intention of simultaneously varying the heat flux and changing the local gradient. The electron temperature gradient scale length (LTe-1 = |∇Te|/Te) profile was measured via the BT-jog technique [Houshmandyar et al., Rev. Sci. Instrum. 87, 11E101 (2016)] and it was compared with electron heat flux from power balance (TRANSP) analysis. The Te profiles were found to be very stiff and already above the critical values, however, the stiffness was found to be reduced near the q = 3/2 surface. The measured Lc profile is in agreement with electron temperature gradient (ETG) models which predict the dependence of Lc-1 on local Zeff, Te/Ti, and the ratio of the magnetic shear to the safety factor. The results from linear Gene gyrokinetic simulations suggest ETG to be the dominant mode of turbulence in the electron scale (k⊥ρs > 1), and ion temperature gradient/trapped electron mode modes in the ion scale (k⊥ρs < 1). The measured Lc profile is in agreement with the profile of ETG critical gradients deduced from Gene simulations.

  12. Reaching Beyond The Stars

    Science.gov (United States)

    Baker, Mariah; Rosenthal, L.; Gaughan, A.; Hopkins, E.

    2014-01-01

    Strawbridge Observatory at Haverford College is home to a undergraduate-led public observing program. Our program holds ~once monthly public events throughout the academic year that take advantage of eyepiece observing on our 16-inch and 12-inch telescopes as well as of the classroom, library, and projection system. These resources allow us to organize a variety of astronomy related activities that are engaging for individuals of all ages: accessible student talks, current film screenings and even arts and crafts for the families who attend with young children. These events aim to spark curiosity in others about scientific discovery and about the remarkable nature of the world in which we live. In addition to exciting local families about astronomy, this program has excited Haverford students from a range of disciplines about both science and education. Being entirely student led means that we are able to take the initiative in planning, coordinating and running all events, fostering an atmosphere of collaboration, experimentation and commitment amongst our volunteers. Additionally, this program is one of the few at Haverford that regularly reaches beyond the campus walls to promote and build relationships with the outside community. In light of this, our program presents a distinctive and enlightening opportunity for student volunteers: we get to use our scientific backgrounds to educate a general audience, while also learning from them about how to communicate and inspire in others the excitement we feel about the subject of astronomy. The work on this project has been supported by NSF AST-1151462.

  13. GAP-REACH

    Science.gov (United States)

    Lewis-Fernández, Roberto; Raggio, Greer A.; Gorritz, Magdaliz; Duan, Naihua; Marcus, Sue; Cabassa, Leopoldo J.; Humensky, Jennifer; Becker, Anne E.; Alarcón, Renato D.; Oquendo, María A.; Hansen, Helena; Like, Robert C.; Weiss, Mitchell; Desai, Prakash N.; Jacobsen, Frederick M.; Foulks, Edward F.; Primm, Annelle; Lu, Francis; Kopelowicz, Alex; Hinton, Ladson; Hinton, Devon E.

    2015-01-01

    Growing awareness of health and health care disparities highlights the importance of including information about race, ethnicity, and culture (REC) in health research. Reporting of REC factors in research publications, however, is notoriously imprecise and unsystematic. This article describes the development of a checklist to assess the comprehensiveness and the applicability of REC factor reporting in psychiatric research publications. The 16-itemGAP-REACH© checklist was developed through a rigorous process of expert consensus, empirical content analysis in a sample of publications (N = 1205), and interrater reliability (IRR) assessment (N = 30). The items assess each section in the conventional structure of a health research article. Data from the assessment may be considered on an item-by-item basis or as a total score ranging from 0% to 100%. The final checklist has excellent IRR (κ = 0.91). The GAP-REACH may be used by multiple research stakeholders to assess the scope of REC reporting in a research article. PMID:24080673

  14. UX-15 Reaches LEP

    CERN Multimedia

    2001-01-01

    The creation of the world's largest sandstone cavern, not a small feat! At the bottom, cave-in preventing steel mesh can be seen clinging to the top of the tunnel. The digging of UX-15, the cavern that will house ATLAS, reached the upper ceiling of LEP on October 10th. The breakthrough which took place nearly 100 metres underground occurred precisely on schedule and exactly as planned. But much caution was taken beforehand to make the LEP breakthrough clean and safe. To prevent the possibility of cave-ins in the side tunnels that will eventually be attached to the completed UX-15 cavern, reinforcing steel mesh was fixed into the walls with bolts. Obviously no people were allowed in the LEP tunnels below UX-15 as the breakthrough occurred. The area was completely evacuated and fences were put into place to keep all personnel out. However, while personnel were being kept out of the tunnels below, this has been anything but the case for the work taking place up above. With the creation of the world's largest...

  15. Has Silicon Reached It's Limit?

    Directory of Open Access Journals (Sweden)

    Alan John Charles Davidson

    2014-01-01

    Full Text Available In light of the rapidly increasing demand for ultra-high speed data transmission, data centres are under pressure to provide ever increasing data transmission through their networks and at the same time improve the quality of data handling in terms of reduced latency, increased scalability and improved channel speed for users. However as data rates increase, present electronic switching technology using current data centre architecture is becoming increasingly difficult to scale despite improvements in data management. In this paper the tremendous bandwidth potential of optical fibre based networks will be explored alongside the issues of electronic scalability and switching speed. A resulting need for alternative optical solutions for all-optical signal processing systems will be discussed. With this in mind, progress in the form of a novel and highly scalable optical interconnect will be reviewed.

  16. Electron beam fabrication of a microfluidic device for studying submicron-scale bacteria

    Science.gov (United States)

    2013-01-01

    Background Controlled restriction of cellular movement using microfluidics allows one to study individual cells to gain insight into aspects of their physiology and behaviour. For example, the use of micron-sized growth channels that confine individual Escherichia coli has yielded novel insights into cell growth and death. To extend this approach to other species of bacteria, many of whom have dimensions in the sub-micron range, or to a larger range of growth conditions, a readily-fabricated device containing sub-micron features is required. Results Here we detail the fabrication of a versatile device with growth channels whose widths range from 0.3 μm to 0.8 μm. The device is fabricated using electron beam lithography, which provides excellent control over the shape and size of different growth channels and facilitates the rapid-prototyping of new designs. Features are successfully transferred first into silicon, and subsequently into the polydimethylsiloxane that forms the basis of the working microfluidic device. We demonstrate that the growth of sub-micron scale bacteria such as Lactococcus lactis or Escherichia coli cultured in minimal medium can be followed in such a device over several generations. Conclusions We have presented a detailed protocol based on electron beam fabrication together with specific dry etching procedures for the fabrication of a microfluidic device suited to study submicron-sized bacteria. We have demonstrated that both Gram-positive and Gram-negative bacteria can be successfully loaded and imaged over a number of generations in this device. Similar devices could potentially be used to study other submicron-sized organisms under conditions in which the height and shape of the growth channels are crucial to the experimental design. PMID:23575419

  17. Femtosecond planar electron beam source for micron-scale dielectric wake field accelerator

    Directory of Open Access Journals (Sweden)

    T. C. Marshall

    2001-12-01

    Full Text Available A new accelerator, LACARA (laser-driven cyclotron autoresonance accelerator, under construction at the Accelerator Test Facility at Brookhaven National Laboratory, is to be powered by a 1 TW CO_{2} laser beam and a 50 MeV injected electron pulse. LACARA will produce inside a 2 m, 6 T solenoid a 100 MeV gyrating electron bunch, with ∼3% energy spread, approximately 1 psec in length with particles advancing in phase at the laser frequency, executing one cycle each 35 fsec. A beamstop with a small off axis channel will transmit a short beam pulse every optical cycle, thereby producing a train of about 30, 3.5 fsec long, 1–3 pC microbunches for each laser pulse. We describe here a novel accelerator, a micron-scale dielectric wake field accelerator driven by a 500 MeV LACARA-type injector that takes the output train of microbunches and transforms them into a near-rectangular cross section having a narrow dimension of ∼10 μm and height of ∼150 μm using a magnetic quadrupole; these bunches may be injected into a planar dielectric-lined waveguide (slightly larger than the bunch where cumulative buildup of wake fields can lead to an accelerating gradient >1 GV/m. This proposed vacuum-based wake field structure is physically rigid and capable of microfabrication accuracy, factors important in staging a large number of accelerator modules. Furthermore, the accelerating gradients it promises are comparable with those for plasma accelerators. A LACARA unit for preparing suitable bunches at 500 MeV is described. Physics issues are discussed, including bunch spreading and transport, bunch shaping, coherent diffraction radiation from the aperture, dielectric breakdown, and bunch stability in the rectangular wake field structure.

  18. Potential up-scaling of inkjet-printed devices for logical circuits in flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Kalyan Yoti, E-mail: kalyan-yoti.mitra@mb.tu-chemnitz.de, E-mail: enrico.sowade@mb.tu-chemnitz.de; Sowade, Enrico, E-mail: kalyan-yoti.mitra@mb.tu-chemnitz.de, E-mail: enrico.sowade@mb.tu-chemnitz.de [Technische Universität Chemnitz, Department of Digital Printing and Imaging Technology, Chemnitz (Germany); Martínez-Domingo, Carme [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra, Spain and Nanobioelectronics and Biosensors Group, Catalan Institute of Nanotechnology (ICN), Universitat Autònoma de Barcelona, Bellaterra, Catalonia (Spain); Ramon, Eloi, E-mail: eloi.ramon@uab.cat [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra (Spain); Nanobioelectronics and Biosensors Group, Catalan Institute of Nanotechnology (ICN), Universitat Autònoma de Barcelona, Bellaterra, Catalonia (Spain); Carrabina, Jordi, E-mail: jordi.carrabina@uab.cat [Printed Microelectronics Group, CAIAC, Universitat Autònoma de Barcelona, Bellaterra (Spain); Gomes, Henrique Leonel, E-mail: hgomes@ualg.pt [Universidade do Algarve, Institute of Telecommunications, Faro (Portugal); Baumann, Reinhard R., E-mail: reinhard.baumann@mb.tu-chemnitz.de [Technische Universität Chemnitz, Department of Digital Printing and Imaging Technology, Chemnitz (Germany); Fraunhofer Institute for Electronic Nano Systems (ENAS), Department of Printed Functionalities, Chemnitz (Germany)

    2015-02-17

    Inkjet Technology is often mis-believed to be a deposition/patterning technology which is not meant for high fabrication throughput in the field of printed and flexible electronics. In this work, we report on the 1) printing, 2) fabrication yield and 3) characterization of exemplary simple devices e.g. capacitors, organic transistors etc. which are the basic building blocks for logical circuits. For this purpose, printing is performed first with a Proof of concept Inkjet printing system Dimatix Material Printer 2831 (DMP 2831) using 10 pL small print-heads and then with Dimatix Material Printer 3000 (DMP 3000) using 35 pL industrial print-heads (from Fujifilm Dimatix). Printing at DMP 3000 using industrial print-heads (in Sheet-to-sheet) paves the path towards industrialization which can be defined by printing in Roll-to-Roll format using industrial print-heads. This pavement can be termed as 'Bridging Platform'. This transfer to 'Bridging Platform' from 10 pL small print-heads to 35 pL industrial print-heads help the inkjet-printed devices to evolve on the basis of functionality and also in form of up-scaled quantities. The high printed quantities and yield of inkjet-printed devices justify the deposition reliability and potential to print circuits. This reliability is very much desired when it comes to printing of circuits e.g. inverters, ring oscillator and any other planned complex logical circuits which require devices e.g. organic transistors which needs to get connected in different staged levels. Also, the up-scaled inkjet-printed devices are characterized and they reflect a domain under which they can work to their optimal status. This status is much wanted for predicting the real device functionality and integration of them into a planned circuit.

  19. Potential up-scaling of inkjet-printed devices for logical circuits in flexible electronics

    International Nuclear Information System (INIS)

    Mitra, Kalyan Yoti; Sowade, Enrico; Martínez-Domingo, Carme; Ramon, Eloi; Carrabina, Jordi; Gomes, Henrique Leonel; Baumann, Reinhard R.

    2015-01-01

    Inkjet Technology is often mis-believed to be a deposition/patterning technology which is not meant for high fabrication throughput in the field of printed and flexible electronics. In this work, we report on the 1) printing, 2) fabrication yield and 3) characterization of exemplary simple devices e.g. capacitors, organic transistors etc. which are the basic building blocks for logical circuits. For this purpose, printing is performed first with a Proof of concept Inkjet printing system Dimatix Material Printer 2831 (DMP 2831) using 10 pL small print-heads and then with Dimatix Material Printer 3000 (DMP 3000) using 35 pL industrial print-heads (from Fujifilm Dimatix). Printing at DMP 3000 using industrial print-heads (in Sheet-to-sheet) paves the path towards industrialization which can be defined by printing in Roll-to-Roll format using industrial print-heads. This pavement can be termed as 'Bridging Platform'. This transfer to 'Bridging Platform' from 10 pL small print-heads to 35 pL industrial print-heads help the inkjet-printed devices to evolve on the basis of functionality and also in form of up-scaled quantities. The high printed quantities and yield of inkjet-printed devices justify the deposition reliability and potential to print circuits. This reliability is very much desired when it comes to printing of circuits e.g. inverters, ring oscillator and any other planned complex logical circuits which require devices e.g. organic transistors which needs to get connected in different staged levels. Also, the up-scaled inkjet-printed devices are characterized and they reflect a domain under which they can work to their optimal status. This status is much wanted for predicting the real device functionality and integration of them into a planned circuit

  20. Virtual rough samples to test 3D nanometer-scale scanning electron microscopy stereo photogrammetry.

    Science.gov (United States)

    Villarrubia, J S; Tondare, V N; Vladár, A E

    2016-01-01

    The combination of scanning electron microscopy for high spatial resolution, images from multiple angles to provide 3D information, and commercially available stereo photogrammetry software for 3D reconstruction offers promise for nanometer-scale dimensional metrology in 3D. A method is described to test 3D photogrammetry software by the use of virtual samples-mathematical samples from which simulated images are made for use as inputs to the software under test. The virtual sample is constructed by wrapping a rough skin with any desired power spectral density around a smooth near-trapezoidal line with rounded top corners. Reconstruction is performed with images simulated from different angular viewpoints. The software's reconstructed 3D model is then compared to the known geometry of the virtual sample. Three commercial photogrammetry software packages were tested. Two of them produced results for line height and width that were within close to 1 nm of the correct values. All of the packages exhibited some difficulty in reconstructing details of the surface roughness.

  1. Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

    International Nuclear Information System (INIS)

    Volpe, C.; Welzel, J.

    2007-01-01

    We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic ν e and ν-bar e fluxes and on the number of events for ν e + C 12 , ν e + O 16 , ν e + Ar 40 and ν-bar e + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

  2. Supernova relic electron neutrinos and anti-neutrinos in future large-scale observatories

    Energy Technology Data Exchange (ETDEWEB)

    Volpe, C.; Welzel, J. [Institut de Physique Nuclueaire, 91 - Orsay (France)

    2007-07-01

    We investigate the signal from supernova relic neutrinos in future large scale observatories, such as MEMPHYS (UNO, Hyper-K), LENA and GLACIER, at present under study. We discuss that complementary information might be gained from the observation of supernova relic electron antineutrinos and neutrinos using the scattering on protons on one hand, and on nuclei such as oxygen, carbon or argon on the other hand. When determining the relic neutrino fluxes we also include, for the first time, the coupling of the neutrino magnetic moment to magnetic fields within the core collapse supernova. We present numerical results on both the relic {nu}{sub e} and {nu}-bar{sub e} fluxes and on the number of events for {nu}{sub e} + C{sup 12}, {nu}{sub e} + O{sup 16}, {nu}{sub e} + Ar{sup 40} and {nu}-bar{sub e} + p for various oscillation scenarios. The observation of supernova relic neutrinos might provide us with unique information on core-collapse supernova explosions, on the star formation history and on neutrino properties, that still remain unknown. (authors)

  3. GPU-accelerated brain connectivity reconstruction and visualization in large-scale electron micrographs

    KAUST Repository

    Jeong, Wonki

    2011-01-01

    This chapter introduces a GPU-accelerated interactive, semiautomatic axon segmentation and visualization system. Two challenging problems have been addressed: the interactive 3D axon segmentation and the interactive 3D image filtering and rendering of implicit surfaces. The reconstruction of neural connections to understand the function of the brain is an emerging and active research area in neuroscience. With the advent of high-resolution scanning technologies, such as 3D light microscopy and electron microscopy (EM), reconstruction of complex 3D neural circuits from large volumes of neural tissues has become feasible. Among them, only EM data can provide sufficient resolution to identify synapses and to resolve extremely narrow neural processes. These high-resolution, large-scale datasets pose challenging problems, for example, how to process and manipulate large datasets to extract scientifically meaningful information using a compact representation in a reasonable processing time. The running time of the multiphase level set segmentation method has been measured on the CPU and GPU. The CPU version is implemented using the ITK image class and the ITK distance transform filter. The numerical part of the CPU implementation is similar to the GPU implementation for fair comparison. The main focus of this chapter is introducing the GPU algorithms and their implementation details, which are the core components of the interactive segmentation and visualization system. © 2011 Copyright © 2011 NVIDIA Corporation and Wen-mei W. Hwu Published by Elsevier Inc. All rights reserved..

  4. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  5. Inexpensive read-out for coincident electron spectroscopy with a transmission electron microscope at nanometer scale using micro channel plates and multistrip anodes

    International Nuclear Information System (INIS)

    Hollander, R.W.; Bom, V.R.; Van Eijk, C.W.E.; Faber, J.S.; Hoevers, H.; Kruit, P.

    1994-01-01

    The elemental composition of a sample at nanometer scale is determined by measurement of the characteristic energy of Auger electrons, emitted in coincidence with incoming primary electrons from a microbeam in a scanning transmission electron microscope (STEM). Single electrons are detected with position sensitive detectors, consisting of MicroChannel Plates (MCP) and MultiStrip Anodes (MSA), one for the energy of the Auger electrons (Auger-detector) and one for the energy loss of primary electrons (EELS-detector). The MSAs are sensed with LeCroy 2735DC preamplifiers. The fast readout is based on LeCroy's PCOS III system. On the detection of a coincidence (Event) energy data of Auger and EELS are combined with timing data to an Event word. Event words are stored in list mode in a VME memory module. Blocks of Event words are scanned by transputers in VME and two-dimensional energy histograms are filled using the timing information to obtain a maximal true/accidental ratio. The resulting histograms are stored on disk of a PC-386, which also controls data taking. The system is designed to handle 10 5 Events per second, 90% of which are accidental. In the histograms the ''true'' to ''accidental'' ratio will be 5. The dead time is 15%. ((orig.))

  6. Unconventional scaling of the anomalous Hall effect accompanying electron localization correction in the dirty regime

    KAUST Repository

    Lu, Y. M.; Cai, J. W.; Guo, Zaibing; Zhang, Xixiang

    2013-01-01

    Pt films. The relationship between electron transport and temperature reveals a quantitatively insignificant Coulomb interaction in these films, while the temperature dependent anomalous Hall conductivity experiences quantum correction from electron

  7. Detour factors in water and plastic phantoms and their use for range and depth scaling in electron-beam dosimetry

    International Nuclear Information System (INIS)

    Fernandez-Varea, J.M.; Andreo, P.; Tabata, T.

    1996-01-01

    Average penetration depths and detour factors of 1-50 MeV electrons in water and plastic materials have been computed by means of analytical calculation, within the continuous-slowing-down approximation and including multiple scattering, and using the Monte Carlo codes ITS and PENELOPE. Results are compared to detour factors from alternative definitions previously proposed in the literature. Different procedures used in low-energy electron-beam dosimetry to convert ranges and depths measured in plastic phantoms into water-equivalent ranges and depths are analysed. A new simple and accurate scaling method, based on Monte Carlo-derived ratios of average electron penetration depths and thus incorporating the effect of multiple scattering, is presented. Data are given for most plastics used in electron-beam dosimetry together with a fit which extends the method to any other low-Z plastic material. A study of scaled depth - dose curves and mean energies as a function of depth for some plastics of common usage shows that the method improves the consistency and results of other scaling procedures in dosimetry with electron beams at therapeutic energies. (author)

  8. Minerals and aligned collagen fibrils in tilapia fish scales: structural analysis using dark-field and energy-filtered transmission electron microscopy and electron tomography.

    Science.gov (United States)

    Okuda, Mitsuhiro; Ogawa, Nobuhiro; Takeguchi, Masaki; Hashimoto, Ayako; Tagaya, Motohiro; Chen, Song; Hanagata, Nobutaka; Ikoma, Toshiyuki

    2011-10-01

    The mineralized structure of aligned collagen fibrils in a tilapia fish scale was investigated using transmission electron microscopy (TEM) techniques after a thin sample was prepared using aqueous techniques. Electron diffraction and electron energy loss spectroscopy data indicated that a mineralized internal layer consisting of aligned collagen fibrils contains hydroxyapatite crystals. Bright-field imaging, dark-field imaging, and energy-filtered TEM showed that the hydroxyapatite was mainly distributed in the hole zones of the aligned collagen fibrils structure, while needle-like materials composed of calcium compounds including hydroxyapatite existed in the mineralized internal layer. Dark-field imaging and three-dimensional observation using electron tomography revealed that hydroxyapatite and needle-like materials were mainly found in the matrix between the collagen fibrils. It was observed that hydroxyapatite and needle-like materials were preferentially distributed on the surface of the hole zones in the aligned collagen fibrils structure and in the matrix between the collagen fibrils in the mineralized internal layer of the scale.

  9. Size-scaling behaviour of the electronic polarizability of one-dimensional interacting systems

    Science.gov (United States)

    Chiappe, G.; Louis, E.; Vergés, J. A.

    2018-05-01

    Electronic polarizability of finite chains is accurately calculated from the total energy variation of the system produced by small but finite static electric fields applied along the chain direction. Normalized polarizability, that is, polarizability divided by chain length, diverges as the second power of length for metallic systems but approaches a constant value for insulating systems. This behaviour provides a very convenient way to characterize the wave-function malleability of finite systems as it avoids the need of attaching infinite contacts to the chain ends. Hubbard model calculations at half filling show that the method works for a small U  =  1 interaction value that corresponds to a really small spectral gap of 0.005 (hopping t  =  ‑1 is assumed). Once successfully checked, the method has been applied to the long-range hopping model of Gebhard and Ruckenstein showing 1/r hopping decay (Gebhard and Ruckenstein 1992 Phys. Rev. Lett. 68 244; Gebhard et al 1994 Phys. Rev. B 49 10926). Metallicity for U values below the reported metal-insulator transition is obtained but the surprise comes for U values larger than the critical one (when a gap appears in the spectral density of states) because a steady increase of the normalized polarizability with size is obtained. This critical size-scaling behaviour can be understood as corresponding to a molecule which polarizability is unbounded. We have checked that a real transfer of charge from one chain end to the opposite occurs as a response to very small electric fields in spite of the existence of a large gap of the order of U for one-particle excitations. Finally, ab initio quantum chemistry calculations of realistic poly-acetylene chains prove that the occurrence of such critical behaviour in real systems is unlikely.

  10. Small scale structure of magnetospheric electron density through on-line tracking of plasma resonances

    International Nuclear Information System (INIS)

    Higel, B.

    1978-01-01

    The plasma resonance phenomena observed at fsub(pe), nfsub(ce), and fsub(qn) by the GEOS-1 S-301 relaxation sounder are identified through a pattern recognition software process implemented in a mini-computer which receives on-line the compressed data. First, this processing system distributes in real time fsub(pe) and fsub(ce) measurements to the ground media. Second, it drives and controls automatically the S-301 on-board experiment by sending appropriate telecommands: the tracking of resonances is performed by shortening the frequency sweeps to a narrow range centered on the resonance location. Examples of such tracking sequences are presented, exhibiting sampling rates of the electron density measurements from once every 22s (slowest rate) to once every 86 ms (highest rate available). The results give evidence of the existence of very small scale structures in the magnetospheric density, having characteristic sizes of the order of a few 10 2 m or/and a few 10 -1 s. The relative amplitude of these density fluctuations is typically 1%. Because of satellite spinning, fixed frequency sounding sequences allow to measure in a few seconds the directivity features of the plasma resonance signals. Examples of directional patterns in the plane perpendicular to the geomagnetic field are presented: the electrostatic nature of the waves received at fsub(pe), nfsub(ce), and fsub(qn) being consistent with these patterns, the corresponding k vector orientations become available. The Bernstein modes properties are used to interpret the nfsub(ce) and fsub(qn) results. (Auth.)

  11. Electron Jet of Asymmetric Reconnection

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Graham, D. B.; Norgren, C.; Eriksson, E.; Li, W.; Johlander, A.; Vaivads, A.; Andre, M.; Pritchett, P. L.; Retino, A.; hide

    2016-01-01

    We present Magnetospheric Multiscale observations of an electron-scale current sheet and electron outflow jet for asymmetric reconnection with guide field at the subsolar magnetopause. The electron jet observed within the reconnection region has an electron Mach number of 0.35 and is associated with electron agyrotropy. The jet is unstable to an electrostatic instability which generates intense waves with E(sub parallel lines) amplitudes reaching up to 300 mV/m and potentials up to 20% of the electron thermal energy. We see evidence of interaction between the waves and the electron beam, leading to quick thermalization of the beam and stabilization of the instability. The wave phase speed is comparable to the ion thermal speed, suggesting that the instability is of Buneman type, and therefore introduces electron-ion drag and leads to braking of the electron flow. Our observations demonstrate that electrostatic turbulence plays an important role in the electron-scale physics of asymmetric reconnection.

  12. GeV electron beams from centimeter-scale channel guided laser wakefield

    International Nuclear Information System (INIS)

    Gonsalves, A.; Nakamura, K.; Panasenko, D.; Toth, Cs.; Esarey, E.; Schroeder; Hooker, S.M.; Leemans, W.P.; Hooker, S.M.

    2007-01-01

    Results are presented on the generation of quasi-monoenergetic electron beams with energy up to 1 GeV using a 40TW laser and a 3.3 cm-long hydrogen-filled capillary discharge waveguide. Electron beams were not observed without a plasma channel, indicating that self-focusing alone could not be relied upon for effective guiding of the laser pulse. Results are presented of the electron beam spectra, and the dependence of the reliability of producing electron beams as a function of laser and plasma parameters

  13. Measurement of the High-Mass Drell-Yan Cross Section and Limits on Quark-Electron Compositeness Scales

    International Nuclear Information System (INIS)

    Grinstein, S.; Mostafa, M.; Piegaia, R.; Alves, G.A.; Carvalho, W.; Maciel, A.K.; Motta, H. da; Oliveira, E.; Santoro, A.; Lima, J.G.; Oguri, V.; Gomez, B.; Hoeneisen, B.; Mooney, P.; Negret, J.P.; Ducros, Y.; Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B.; Shivpuri, R.K.; Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Parua, N.; Shankar, H.C.; Park, Y.M.; Choi, S.; Kim, S.K.; Castilla-Valdez, H.; Gonzalez Solis, J.L.; Hernandez-Montoya, R.; Magana-Mendoza, L.; Sanchez-Hernandez, A.; Pawlik, B.; Gavrilov, V.; Gershtein, Y.; Kuleshov, S.; Belyaev, A.; Dudko, L.V.; Ermolov, P.; Karmanov, D.; Leflat, A.; Manankov, V.; Merkin, M.; Shabalina, E.; Abramov, V.; Babintsev, V.V.; Bezzubov, V.A.; Bojko, N.I.; Burtovoi, V.S.; Chekulaev, S.V.; Denisov, S.P.; Dyshkant, A.; Eroshin, O.V.; Evdokimov, V.N.; Galyaev, A.N.; Goncharov, P.I.; Gurzhiev, S.N.; Kostritskiy, A.V.; Kozelov, A.V.; Kozlovsky, E.A.; Mayorov, A.A.; Babukhadia, L.; Davis, K.; Fein, D.; Forden, G.E.; Guida, J.A.; Johns, K.; Nang, F.; Narayanan, A.; Rutherfoord, J.; Shupe, M.; Aihara, H.; Barberis, E.; Clark, A.R.

    1999-01-01

    We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120 pb -1 of data collected in p bar p collisions at √ (s) =1.8 TeV by the D0 Collaboration during 1992 - 1996. No deviation from standard model expectations is observed. We use the data to set limits on the quark-electron compositeness scale. The 95% confidence level lower limits on the compositeness scale vary between 3.3 and 6.1thinspthinspTeV depending on the assumed form of the effective contact interaction. copyright 1999 The American Physical Society

  14. Accurate density functional prediction of molecular electron affinity with the scaling corrected Kohn–Sham frontier orbital energies

    Science.gov (United States)

    Zhang, DaDi; Yang, Xiaolong; Zheng, Xiao; Yang, Weitao

    2018-04-01

    Electron affinity (EA) is the energy released when an additional electron is attached to an atom or a molecule. EA is a fundamental thermochemical property, and it is closely pertinent to other important properties such as electronegativity and hardness. However, accurate prediction of EA is difficult with density functional theory methods. The somewhat large error of the calculated EAs originates mainly from the intrinsic delocalisation error associated with the approximate exchange-correlation functional. In this work, we employ a previously developed non-empirical global scaling correction approach, which explicitly imposes the Perdew-Parr-Levy-Balduz condition to the approximate functional, and achieve a substantially improved accuracy for the calculated EAs. In our approach, the EA is given by the scaling corrected Kohn-Sham lowest unoccupied molecular orbital energy of the neutral molecule, without the need to carry out the self-consistent-field calculation for the anion.

  15. CMOS compatible route for GaAs based large scale flexible and transparent electronics

    KAUST Repository

    Nour, Maha A.; Ghoneim, Mohamed T.; Droopad, Ravi; Hussain, Muhammad Mustafa

    2014-01-01

    Flexible electronics using gallium arsenide (GaAs) for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. Here we describe a state-of-the-art CMOS compatible batch fabrication process of transforming traditional electronic circuitry into large-area flexible, semitransparent platform. We show a simple release process for peeling off 200 nm of GaAs from 200 nm GaAs/300 nm AlAs stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes which contributes to the better transparency (45 % at 724 nm wavelength) observed.

  16. Solid electron sources for the energy scale monitoring in the KATRIN experiment

    CERN Document Server

    Zbořil, Miroslav; Vénos, D

    The KArlsruhe TRItium Neutrino (KATRIN) experiment represents a next-generation tritium $\\beta$-decay experiment designed to perform a high precision direct measurement of the electron anti-neutrino mass m($\

  17. CMOS compatible route for GaAs based large scale flexible and transparent electronics

    KAUST Repository

    Nour, Maha A.

    2014-08-01

    Flexible electronics using gallium arsenide (GaAs) for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. Here we describe a state-of-the-art CMOS compatible batch fabrication process of transforming traditional electronic circuitry into large-area flexible, semitransparent platform. We show a simple release process for peeling off 200 nm of GaAs from 200 nm GaAs/300 nm AlAs stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes which contributes to the better transparency (45 % at 724 nm wavelength) observed.

  18. Atomic-scale Visualization of Electronic Nematicity and Cooper Pairing in Iron-based Superconductors

    Science.gov (United States)

    Allan, Milan P.

    2013-03-01

    The mechanism of high-temperature superconductivity in the relatively novel iron-based high-Tc superconductors is unresolved, both in terms of how the phases evolve with doping, and in terms of the actual Cooper pairing process. To explore these issues, we used spectroscopic-imaging scanning tunneling microscopy to study the electronic structure of CaFe2As2 in the antiferromagnetic-orthorhombic `parent' state from which the superconductivity emerges. We discovered and visualized the now widely studied electronic `nematicity' of this phase, whose suppression is associated with the emergence of superconductivity (Science 327, 181, 2010). As subsequent transport experiments discovered a related anisotropic conductance which increases with dopant concentration, the interplay between the electronic structure surrounding each dopant atom, quasiparticle scattering therefrom, and the transport nematicity has become a pivotal focus of research. We find that substituting Co for Fe atoms in underdoped Ca(Fe1-xCox)2As2 generates a dense population of identical and strongly anisotropic impurity states that are distributed randomly but aligned with the antiferromagnetic a-axis. We also demonstrate, by imaging their surrounding interference patterns, that these impurity states scatter quasiparticles and thus influence transport in a highly anisotropic manner (M.P. Allan et al., 2013). Next, we studied the momentum dependence of the energy gaps of iron-based superconductivity, now focusing on LiFeAs. If strong electron-electron interactions mediate the Cooper pairing, then momentum-space anisotropic superconducting energy gaps Δi (k) were predicted by multiple techniques to appear on the different electronic bands i. We introduced intraband Bogoliubov quasiparticle scattering interference (QPI) techniques for the determination of anisotropic energy gaps to test these hypotheses and discovered the anisotropy, magnitude, and relative orientations of the energy gaps on multiple

  19. The Properties of Lion Roars and Electron Dynamics in Mirror Mode Waves Observed by the Magnetospheric MultiScale Mission

    Science.gov (United States)

    Breuillard, H.; Le Contel, O.; Chust, T.; Berthomier, M.; Retino, A.; Turner, D. L.; Nakamura, R.; Baumjohann, W.; Cozzani, G.; Catapano, F.; Alexandrova, A.; Mirioni, L.; Graham, D. B.; Argall, M. R.; Fischer, D.; Wilder, F. D.; Gershman, D. J.; Varsani, A.; Lindqvist, P.-A.; Khotyaintsev, Yu. V.; Marklund, G.; Ergun, R. E.; Goodrich, K. A.; Ahmadi, N.; Burch, J. L.; Torbert, R. B.; Needell, G.; Chutter, M.; Rau, D.; Dors, I.; Russell, C. T.; Magnes, W.; Strangeway, R. J.; Bromund, K. R.; Wei, H.; Plaschke, F.; Anderson, B. J.; Le, G.; Moore, T. E.; Giles, B. L.; Paterson, W. R.; Pollock, C. J.; Dorelli, J. C.; Avanov, L. A.; Saito, Y.; Lavraud, B.; Fuselier, S. A.; Mauk, B. H.; Cohen, I. J.; Fennell, J. F.

    2018-01-01

    Mirror mode waves are ubiquitous in the Earth's magnetosheath, in particular behind the quasi-perpendicular shock. Embedded in these nonlinear structures, intense lion roars are often observed. Lion roars are characterized by whistler wave packets at a frequency ˜100 Hz, which are thought to be generated in the magnetic field minima. In this study, we make use of the high time resolution instruments on board the Magnetospheric MultiScale mission to investigate these waves and the associated electron dynamics in the quasi-perpendicular magnetosheath on 22 January 2016. We show that despite a core electron parallel anisotropy, lion roars can be generated locally in the range 0.05-0.2fce by the perpendicular anisotropy of electrons in a particular energy range. We also show that intense lion roars can be observed up to higher frequencies due to the sharp nonlinear peaks of the signal, which appear as sharp spikes in the dynamic spectra. As a result, a high sampling rate is needed to estimate correctly their amplitude, and the latter might have been underestimated in previous studies using lower time resolution instruments. We also present for the first-time 3-D high time resolution electron velocity distribution functions in mirror modes. We demonstrate that the dynamics of electrons trapped in the mirror mode structures are consistent with the Kivelson and Southwood (1996) model. However, these electrons can also interact with the embedded lion roars: first signatures of electron quasi-linear pitch angle diffusion and possible signatures of nonlinear interaction with high-amplitude wave packets are presented. These processes can lead to electron untrapping from mirror modes.

  20. PubChemQC Project: A Large-Scale First-Principles Electronic Structure Database for Data-Driven Chemistry.

    Science.gov (United States)

    Nakata, Maho; Shimazaki, Tomomi

    2017-06-26

    Large-scale molecular databases play an essential role in the investigation of various subjects such as the development of organic materials, in silico drug design, and data-driven studies with machine learning. We have developed a large-scale quantum chemistry database based on first-principles methods. Our database currently contains the ground-state electronic structures of 3 million molecules based on density functional theory (DFT) at the B3LYP/6-31G* level, and we successively calculated 10 low-lying excited states of over 2 million molecules via time-dependent DFT with the B3LYP functional and the 6-31+G* basis set. To select the molecules calculated in our project, we referred to the PubChem Project, which was used as the source of the molecular structures in short strings using the InChI and SMILES representations. Accordingly, we have named our quantum chemistry database project "PubChemQC" ( http://pubchemqc.riken.jp/ ) and placed it in the public domain. In this paper, we show the fundamental features of the PubChemQC database and discuss the techniques used to construct the data set for large-scale quantum chemistry calculations. We also present a machine learning approach to predict the electronic structure of molecules as an example to demonstrate the suitability of the large-scale quantum chemistry database.

  1. Reversed magnetic shear suppression of electron-scale turbulence on NSTX

    Science.gov (United States)

    Yuh, Howard Y.; Levinton, F. M.; Bell, R. E.; Hosea, J. C.; Kaye, S. M.; Leblanc, B. P.; Mazzucato, E.; Smith, D. R.; Domier, C. W.; Luhmann, N. C.; Park, H. K.

    2009-11-01

    Electron thermal internal transport barriers (e-ITBs) are observed in reversed (negative) magnetic shear NSTX discharges^1. These e-ITBs can be created with either neutral beam heating or High Harmonic Fast Wave (HHFW) RF heating. The e-ITB location occurs at the location of minimum magnetic shear determined by Motional Stark Effect (MSE) constrained equilibria. Statistical studies show a threshold condition in magnetic shear for e-ITB formation. High-k fluctuation measurements at electron turbulence wavenumbers^3 have been made under several different transport regimes, including a bursty regime that limits temperature gradients at intermediate magnetic shear. The growth rate of fluctuations has been calculated immediately following a change in the local magnetic shear, resulting in electron temperature gradient relaxation. Linear gyrokinetic simulation results for NSTX show that while measured electron temperature gradients exceed critical linear thresholds for ETG instability, growth rates can remain low under reversed shear conditions up to high electron temperatures gradients. ^1H. Yuh, et. al., PoP 16, 056120 ^2D.R. Smith, E. Mazzucato et al., RSI 75, 3840 ^3E. Mazzucato, D.R. Smith et al., PRL 101, 075001

  2. Improving extreme-scale problem solving: assessing electronic brainstorming effectiveness in an industrial setting.

    Science.gov (United States)

    Dornburg, Courtney C; Stevens, Susan M; Hendrickson, Stacey M L; Davidson, George S

    2009-08-01

    An experiment was conducted to compare the effectiveness of individual versus group electronic brainstorming to address difficult, real-world challenges. Although industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges during the course of 4 days. Employees and contractors at a national laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a real-world problem. The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly (p industrial reliance on electronic problem-solving groups should be tempered, and large nominal groups may be more appropriate corporate problem-solving vehicles.

  3. A Modified Rule of Thumb for Evaluating Scale Reproducibilities Determined by Electronic Computers

    Science.gov (United States)

    Hofmann, Richard J.

    1978-01-01

    The Goodenough technique for determining scale error is compared to the Guttman technique and demonstrated to be more conservative than the Guttman technique. Implications with regard to Guttman's evaluative rule of thumb for evaluating a reproducibility are noted. (Author)

  4. Validating an electronic health literacy scale in an older hispanic population.

    Science.gov (United States)

    Aponte, Judith; Nokes, Kathleen M

    2017-09-01

    To examine the validity of the Spanish version of an instrument used to measure electronic health literacy (eHEALS) with an older Hispanic population from a number of Spanish-language countries living in New York City in the United States (US). Although the Internet is available globally, complex skills are needed to use this source of valuable health-related information effectively. Electronic health literacy is a multifactorial concept that includes health literacy but also requires technology skills. Cross-sectional. Recruitment occurred at a Senior Organization located in a largely Hispanic neighbourhood in New York City (N = 100). Participants completed eHEALS and selected items from the Health Information National Trends Survey (HINTS) which assesses how adults use different communication channels, including the Internet, to obtain vital health information. Data from the US HINTS sample (N = 162) were matched to the Senior Organization sample on age range and Hispanic ethnicity. The average Senior Organization participant was 68 years old, female, born in one of six different Spanish-language countries, and completed high school while the average HINTS participant was 67 years old, female and had high school or less education. Although there was no relationship with the two HINTS subscales and electronic health literacy, there were significant relationships between electronic health literacy and health status and confidence in self-care. Inadequate electronic health literacy is a barrier to positive health outcomes. The Spanish version of eHEALS could be used as a screening instrument to identify gaps and tailored interventions could be developed to increase consumer confidence in using the Internet for reliable health-related information. Knowledge in self-management is related to positive health outcomes; all persons irrespective of their electronic health literacy should be able to use all sources of health information to enhance their self-care.

  5. Quality and reliability assurance of electronic components in small-scale and middle-sized plants

    International Nuclear Information System (INIS)

    Becker, P.

    1982-01-01

    Electronic components are forever finding their way into new fields of application and have an ever increasing influence on the quality and reliability of the products in which they are used. The user has very negligible influence on the production methods used for the manufacture of the components and the element properties. (orig.) [de

  6. Towards TeV-scale electron-positron collisions: the Compact Linear Collider (CLIC)

    Science.gov (United States)

    Doebert, Steffen; Sicking, Eva

    2018-02-01

    The Compact Linear Collider (CLIC), a future electron-positron collider at the energy frontier, has the potential to change our understanding of the universe. Proposed to follow the Large Hardron Collider (LHC) programme at CERN, it is conceived for precision measurements as well as for searches for new phenomena.

  7. Seeing with electrons

    International Nuclear Information System (INIS)

    Nellist, P.

    2006-01-01

    Commercially available lens correctors are extending the reach of electron microscopes to unprecedented atomic scales, as Peter Nellist describes. The electron microscope was invented in 1933 and is based on the principle that electrons have a wavelength that is inversely proportional to their momentum. There are two basic types: transmission electron microscopes and scanning electron microscopes, plus a hybrid of the two. The lenses in an electron microscope are provided by electromagnetic fields, but they suffer from spherical aberration. The addition of octupole and quadrupole corrector fields has improved the resolution of the electron microscope to better than 0.1 nm in the last decade. The next step is to correct for chromatic aberration, after which the resolution of the microscope will probably be limited by the size of the atom itself. (U.K.)

  8. Optical modeling of plasma-deposited ZnO films: Electron scattering at different length scales

    International Nuclear Information System (INIS)

    Knoops, Harm C. M.; Loo, Bas W. H. van de; Smit, Sjoerd; Ponomarev, Mikhail V.; Weber, Jan-Willem; Sharma, Kashish; Kessels, Wilhelmus M. M.; Creatore, Mariadriana

    2015-01-01

    In this work, an optical modeling study on electron scattering mechanisms in plasma-deposited ZnO layers is presented. Because various applications of ZnO films pose a limit on the electron carrier density due to its effect on the film transmittance, higher electron mobility values are generally preferred instead. Hence, insights into the electron scattering contributions affecting the carrier mobility are required. In optical models, the Drude oscillator is adopted to represent the free-electron contribution and the obtained optical mobility can be then correlated with the macroscopic material properties. However, the influence of scattering phenomena on the optical mobility depends on the considered range of photon energy. For example, the grain-boundary scattering is generally not probed by means of optical measurements and the ionized-impurity scattering contribution decreases toward higher photon energies. To understand this frequency dependence and quantify contributions from different scattering phenomena to the mobility, several case studies were analyzed in this work by means of spectroscopic ellipsometry and Fourier transform infrared (IR) spectroscopy. The obtained electrical parameters were compared to the results inferred by Hall measurements. For intrinsic ZnO (i-ZnO), the in-grain mobility was obtained by fitting reflection data with a normal Drude model in the IR range. For Al-doped ZnO (Al:ZnO), besides a normal Drude fit in the IR range, an Extended Drude fit in the UV-vis range could be used to obtain the in-grain mobility. Scattering mechanisms for a thickness series of Al:ZnO films were discerned using the more intuitive parameter “scattering frequency” instead of the parameter “mobility”. The interaction distance concept was introduced to give a physical interpretation to the frequency dependence of the scattering frequency. This physical interpretation furthermore allows the prediction of which Drude models can be used in a specific

  9. Nonadiabatic dynamics of electron transfer in solution: Explicit and implicit solvent treatments that include multiple relaxation time scales

    International Nuclear Information System (INIS)

    Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon

    2014-01-01

    The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible

  10. A pilot rating scale for evaluating failure transients in electronic flight control systems

    Science.gov (United States)

    Hindson, William S.; Schroeder, Jeffery A.; Eshow, Michelle M.

    1990-01-01

    A pilot rating scale was developed to describe the effects of transients in helicopter flight-control systems on safety-of-flight and on pilot recovery action. The scale was applied to the evaluation of hardovers that could potentially occur in the digital flight-control system being designed for a variable-stability UH-60A research helicopter. Tests were conducted in a large moving-base simulator and in flight. The results of the investigation were combined with existing airworthiness criteria to determine quantitative reliability design goals for the control system.

  11. Electron-positron annihilation: unitarity, scaling and electrodynamics at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Karl, G [Guelph Univ., Ontario (Canada); European Organization for Nuclear Research, Geneva (Switzerland))

    1974-01-01

    The work on e/sup +/e/sup -/ annihilation by Cabibbo, Wolfenstein and the author is reviewed. The restrictions of unitarity are analyzed and the connection between the cross sections sigmasub(h) (into hadrons) and sigmasub(..mu..) (into muons) is derived. The possibility of non-scaling in e/sup +/e/sup -/ annihilation is studied and it is pointed out that it leads to no contradiction with presently available information. It is further pointed out that non-scaling could provide a cut-off mechanism for quantum electrodynamics.

  12. Reaching ignition in the tokamak

    International Nuclear Information System (INIS)

    Furth, H.P.

    1985-06-01

    This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project

  13. Modeling heat dominated electric breakdown in air, with adaptivity to electron or ion time scales

    NARCIS (Netherlands)

    Agnihotri, A.; Hundsdorfer, W.; Ebert, U.

    2017-01-01

    We model heat dominated electrical breakdown in air in a short planar gap. We couple the discharge dynamics in fluid approximation with the hydrodynamic motion of the air heated by the discharge. To be computationally efficient, we derive a reduced model on the ion time scale, and we switch between

  14. Electronic cleansing for computed tomography (CT) colonography using a scale-invariant three-material model

    NARCIS (Netherlands)

    Serlie, Iwo W. O.; Vos, Frans M.; Truyen, Roel; Post, Frits H.; Stoker, Jaap; van Vliet, Lucas J.

    2010-01-01

    A well-known reading pitfall in computed tomography (CT) colonography is posed by artifacts at T-junctions, i.e., locations where air-fluid levels interface with the colon wall. This paper presents a scale-invariant method to determine material fractions in voxels near such T-junctions. The proposed

  15. Scaling laws with current for equilibrium momentum spread and emittances from intrabeam scattering and electron cooling

    International Nuclear Information System (INIS)

    Hasse, R.W.; Boine-Frankenheim, O.

    2004-01-01

    Based on the theories of Piwinski, Bjorken-Mtingawa and Martini of Coulomb scattering, expressions for the heating rates due to intrabeam scattering were known since a long time. Simplifications by Wei-Parzen and Rao and Piwinski led to analytic approximations which are easily applicable to existing lattices. We use these approximations and also the formulae from thermal equilibration of Struckmeier and equate them to either constant cooling rates from electron cooling or to the Novosibirsk cooling rates for electron cooling to calculate the equilibrium values of the horizontal and vertical emittances and the momentum spread (longitudinal emittance) for typical beams in the ESR or in the HESR. For constant cooling and all approximation formulae the ratio of current to the product of the three emittances remains almost constant. This yields a slope of the momentum spread with current between 0.2 and 0.3, in agreement with experimental data. Using the Novosibirsk cooling rates this slope is much larger

  16. Hydrogel wound dressing preparation at the laboratory scale by using electron beam and gamma radiation

    International Nuclear Information System (INIS)

    Rapado Raneque, Manuel; Rodriguez Rodriguez, Alejandro; Peniche Covas, Carlos

    2013-01-01

    The present work describes the preparation of hydrogel based on cross-linked networks of poly (N-vinylpirrolidone), PVP, with polyethyleneglicol and agar with 90% water and PVP nancomposites with a synthetic nanoclay, Laponite XLG, for use as burn dressings. These systems were obtained in two ways: using gamma Co-60 and electron beam radiation. The gelation obtained dose was D g = 1.72 kGy. The elastic modulus of hydrogel was independent of the method of irradiation. It was 0.39 MPa for the hydrogel irradiated with gamma Co-60 and 0.38 MPa for electron beam irradiation. The elastic modulus of the nanocomposite membrane was 1.25 MPa, three times higher. These results indicate that the PVP/Laponite XLG nanocomposite hydrogel membrane is the best choice for wound dressing applications due to its high water sorption capacity and its superior mechanical properties.

  17. The adolescence of electronic health records: Status and perspectives for large scale implementation

    Directory of Open Access Journals (Sweden)

    Andreas Drauschke

    2013-06-01

    Full Text Available Health informatics started to evolve decades ago with the intention to support healthcare using computers. Since then Electronic health records (EHRs and personal health records (PHRs have become available but widespread adoption was limited by lack of interoperability and security issues. This paper discusses the feasibility of interoperable standards based EHRs and PHRs drawing on experience from implementation projects. It outlines challenges and goals in education and implementation for the next years.

  18. Electron electric dipole moment in mirror fermion model with electroweak scale non-sterile right-handed neutrinos

    Directory of Open Access Journals (Sweden)

    Chia-Feng Chang

    2018-03-01

    Full Text Available The electric dipole moment of the electron is studied in detail in an extended mirror fermion model with the following unique features of (a right-handed neutrinos are non-sterile and have masses at the electroweak scale, and (b a horizontal symmetry of the tetrahedral group is used in the lepton and scalar sectors. We study the constraint on the parameter space of the model imposed by the latest ACME experimental limit on electron electric dipole moment. Other low energy experimental observables such as the anomalous magnetic dipole moment of the muon, charged lepton flavor violating processes like muon decays into electron plus photon and muon-to-electron conversion in titanium, gold and lead are also considered in our analysis for comparison. In addition to the well-known CP violating Dirac and Majorana phases in the neutrino mixing matrix, the dependence of additional phases of the new Yukawa couplings in the model is studied in detail for all these low energy observables.

  19. Electron electric dipole moment in mirror fermion model with electroweak scale non-sterile right-handed neutrinos

    Science.gov (United States)

    Chang, Chia-Feng; Hung, P. Q.; Nugroho, Chrisna Setyo; Tran, Van Que; Yuan, Tzu-Chiang

    2018-03-01

    The electric dipole moment of the electron is studied in detail in an extended mirror fermion model with the following unique features of (a) right-handed neutrinos are non-sterile and have masses at the electroweak scale, and (b) a horizontal symmetry of the tetrahedral group is used in the lepton and scalar sectors. We study the constraint on the parameter space of the model imposed by the latest ACME experimental limit on electron electric dipole moment. Other low energy experimental observables such as the anomalous magnetic dipole moment of the muon, charged lepton flavor violating processes like muon decays into electron plus photon and muon-to-electron conversion in titanium, gold and lead are also considered in our analysis for comparison. In addition to the well-known CP violating Dirac and Majorana phases in the neutrino mixing matrix, the dependence of additional phases of the new Yukawa couplings in the model is studied in detail for all these low energy observables.

  20. Realizing Large-Scale, Electronic-Grade Two-Dimensional Semiconductors.

    Science.gov (United States)

    Lin, Yu-Chuan; Jariwala, Bhakti; Bersch, Brian M; Xu, Ke; Nie, Yifan; Wang, Baoming; Eichfeld, Sarah M; Zhang, Xiaotian; Choudhury, Tanushree H; Pan, Yi; Addou, Rafik; Smyth, Christopher M; Li, Jun; Zhang, Kehao; Haque, M Aman; Fölsch, Stefan; Feenstra, Randall M; Wallace, Robert M; Cho, Kyeongjae; Fullerton-Shirey, Susan K; Redwing, Joan M; Robinson, Joshua A

    2018-02-27

    Atomically thin transition metal dichalcogenides (TMDs) are of interest for next-generation electronics and optoelectronics. Here, we demonstrate device-ready synthetic tungsten diselenide (WSe 2 ) via metal-organic chemical vapor deposition and provide key insights into the phenomena that control the properties of large-area, epitaxial TMDs. When epitaxy is achieved, the sapphire surface reconstructs, leading to strong 2D/3D (i.e., TMD/substrate) interactions that impact carrier transport. Furthermore, we demonstrate that substrate step edges are a major source of carrier doping and scattering. Even with 2D/3D coupling, transistors utilizing transfer-free epitaxial WSe 2 /sapphire exhibit ambipolar behavior with excellent on/off ratios (∼10 7 ), high current density (1-10 μA·μm -1 ), and good field-effect transistor mobility (∼30 cm 2 ·V -1 ·s -1 ) at room temperature. This work establishes that realization of electronic-grade epitaxial TMDs must consider the impact of the TMD precursors, substrate, and the 2D/3D interface as leading factors in electronic performance.

  1. Small-scale laser based electron accelerators for biology and medicine: a comparative study of the biological effectiveness

    Science.gov (United States)

    Labate, Luca; Andreassi, Maria Grazia; Baffigi, Federica; Basta, Giuseppina; Bizzarri, Ranieri; Borghini, Andrea; Candiano, Giuliana C.; Casarino, Carlo; Cresci, Monica; Di Martino, Fabio; Fulgentini, Lorenzo; Ghetti, Francesco; Gilardi, Maria Carla; Giulietti, Antonio; Köster, Petra; Lenci, Francesco; Levato, Tadzio; Oishi, Yuji; Russo, Giorgio; Sgarbossa, Antonella; Traino, Claudio; Gizzi, Leonida A.

    2013-05-01

    Laser-driven electron accelerators based on the Laser Wakefield Acceleration process has entered a mature phase to be considered as alternative devices to conventional radiofrequency linear accelerators used in medical applications. Before entering the medical practice, however, deep studies of the radiobiological effects of such short bunches as the ones produced by laser-driven accelerators have to be performed. Here we report on the setup, characterization and first test of a small-scale laser accelerator for radiobiology experiments. A brief description of the experimental setup will be given at first, followed by an overview of the electron bunch characterization, in particular in terms of dose delivered to the samples. Finally, the first results from the irradiation of biological samples will be briefly discussed.

  2. Full scale electron beam systems for treatment of water, wastewater and medical waste

    International Nuclear Information System (INIS)

    Waite, T.D.; Kurucz, C.N.; Cooper, W.J.; Brown, D.

    1998-01-01

    High energy electron accelerators have been used in numerous applications for several decades. In the early 1980's several attempts to use electron accelerators for the disinfection of sludge proved that the technology could be used for that application. One such facility was designed, built and tested for one year at the Miami-Dade Virginia Key Wastewater Treatment Plant. The process successfully disinfected anaerobically digested sludge. However, due to changing local regulations the process was never implemented. Now this process may provide a viable alternative for the ultimate destruction of toxic and hazardous organic chemicals from water and sludges. When high energy electrons impact an aqueous solution, with or without particulate matter present, reactive transient species are formed. The three transient species of most interest are the aqueous electron, e - aq, hydrogen radical, H·, and the hydroxyl radical, ·OH. The relative concentration of these radicals in an irradiated solution of pure water is 44, 10 and 46%, respectively. The absolute concentration of the radicals is dose and water quality dependent, but is in excess of mM levels in potable, raw and secondary wastewater effluent at our facility. This paper describes the facilities at the Electron Beam Research Facility (EBRF) in Miami, FL. The accelerator is a 1.5 MeV, 50 mA insulated core transformer type. Several areas of research have been the focus of the studies with an interdisciplinary team of faculty and students in engineering and science. The areas included are, inactivation of bacteria in raw and chlorinated and unchlorinated secondary wastewater and the changes in biochemical oxygen demand and chemical oxygen demand in the raw and unchlorinated secondary wastewater. The removal of toxic chemicals has also been studied in some detail. These studies have been conducted both at the EBRF and using 60 Co gamma irradiation. To examine the effect of water quality on the destruction of the

  3. Pilot scale electron bombardment furnace for continuous casting; application to the trial preparation of 20 kg of uranium monocarbide rods

    International Nuclear Information System (INIS)

    Trouve, J.; Genard, R.; Treillou, A.; Accary, A.

    1964-01-01

    The authors describe a pilot scale electron beam furnace designed for continuous melting and casting of uranium-carbon alloys. This equipment allows the melting and casting processes to be completely automatically controlled, the cooling being carried out under vacuum and the discharge being effected without breaking the vacuum. In a pre-production run of 20 kg of slugs, the composition of practically all the pieces was controlled within ± 0,1 per cent C. The output of the furnace was 2,2 kg/hour. (authors) [fr

  4. Characterization of nanometer-scale porosity in reservoir carbonate rock by focused ion beam-scanning electron microscopy.

    Science.gov (United States)

    Bera, Bijoyendra; Gunda, Naga Siva Kumar; Mitra, Sushanta K; Vick, Douglas

    2012-02-01

    Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam-scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50-300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2-5 μm) that were observed to further link with bulk pores outside the matrix.

  5. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  6. Requirements on read-out electronics for future keV-scale sterile neutrino search with KATRIN

    Energy Technology Data Exchange (ETDEWEB)

    Dolde, Kai [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

    2016-07-01

    Recent publications show the great potential of the KATRIN (KArlsruhe TRItium Neutrino) experiment in the search for sterile neutrinos in the mass range of a few keV down to active-to-sterile mixing angles at least one order of magnitude smaller than current laboratory limits of sin{sup 2}θ < 10{sup -3}. In order to be sensitive to the tiny kink-like signature of sterile neutrinos in tritium beta decay, KATRIN requires a novel sophisticated detector and read-out system. Several silicon prototype detectors are under construction at the moment to explore the most suitable detector design for this purpose. The selection of appropriate read-out electronics is strongly triggered by the requirements of allowing only very small systematic uncertainties due to ADC Non-Linearities to reach the expected sensitivity. This talk investigates the impact of ADC Non-Linearities on the tritium beta decay spectrum, depending on the digitization method of analogue signals of a multi-pixel silicon detector, peak sensing or waveform digitization. The simulations show a higher achievable sensitivity using waveform digitizers and moreover strongly favor additional variable post-acceleration of the electrons to smear out the periodic structure of the ADC Non-Linearities.

  7. Efficient Computation of Sparse Matrix Functions for Large-Scale Electronic Structure Calculations: The CheSS Library.

    Science.gov (United States)

    Mohr, Stephan; Dawson, William; Wagner, Michael; Caliste, Damien; Nakajima, Takahito; Genovese, Luigi

    2017-10-10

    We present CheSS, the "Chebyshev Sparse Solvers" library, which has been designed to solve typical problems arising in large-scale electronic structure calculations using localized basis sets. The library is based on a flexible and efficient expansion in terms of Chebyshev polynomials and presently features the calculation of the density matrix, the calculation of matrix powers for arbitrary powers, and the extraction of eigenvalues in a selected interval. CheSS is able to exploit the sparsity of the matrices and scales linearly with respect to the number of nonzero entries, making it well-suited for large-scale calculations. The approach is particularly adapted for setups leading to small spectral widths of the involved matrices and outperforms alternative methods in this regime. By coupling CheSS to the DFT code BigDFT, we show that such a favorable setup is indeed possible in practice. In addition, the approach based on Chebyshev polynomials can be massively parallelized, and CheSS exhibits excellent scaling up to thousands of cores even for relatively small matrix sizes.

  8. Multi-time scale dynamics in power electronics-dominated power systems

    Science.gov (United States)

    Yuan, Xiaoming; Hu, Jiabing; Cheng, Shijie

    2017-09-01

    Electric power infrastructure has recently undergone a comprehensive transformation from electromagnetics to semiconductors. Such a development is attributed to the rapid growth of power electronic converter applications in the load side to realize energy conservation and on the supply side for renewable generations and power transmissions using high voltage direct current transmission. This transformation has altered the fundamental mechanism of power system dynamics, which demands the establishment of a new theory for power system control and protection. This paper presents thoughts on a theoretical framework for the coming semiconducting power systems.

  9. Fish scale deformation analysis using scanning electron microscope: New potential biomarker in aquatic environmental monitoring of aluminum and iron contamination

    Energy Technology Data Exchange (ETDEWEB)

    Hidayati, Dewi; Sulaiman, Norela; Othman, Shuhaimi; Ismail, B. S. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2013-11-27

    Fish scale has the potential to be a rapid biomarker due to its structure and high possibility to come into contact with any pollutant in the aquatic environment. The scale structure consists of osteoblastic cells and other bone materials such as collagen where it is possible to form a molecular complex with heavy metals such as aluminum and iron. Hence, aluminum and iron in water could possibly destroy the scale material and marked as a scale deformation that quantitatively could be analyzed by comparing it to the normal scale structure. Water sampling and fish cage experiment were performed between June and July 2011 in Porong river which represented the water body that has high aluminum and iron contamination. The filtered water samples were preserved and extracted using the acid-mixture procedure prior to measurement of the aluminum and iron concentrations using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), while samples for total suspended solid (TSS) analysis were kept at 4 °C in cool-boxes. The scales were cleaned with sterile water, then dehydrated in 30, 50, 70, and 90% ethanol and dried on filter papers. They were then mounted on an aluminum stub and coated with gold in a sputter coater prior to Scanning Electron Microscope (SEM) observation. According to the SEM analysis, it was found that there were several deformations on the scale samples taken from sites that have high concentrations of aluminum and iron i.e. the increasing number of pits, deformation and decreasing number of spherules and ridges while the control scale exhibited the normal features. However, the site with higher TSS and pH indicated lower aluminum effect. A moderate correlation was found between the number of pits with aluminum (r=0.43) and iron (r=0.41) concentrations. Fish scale deformation using SEM analysis can potentially be a rapid biomarker in aquatic monitoring of aluminum and iron contamination. However, the measurement must be accompanied by pH and

  10. Fish scale deformation analysis using scanning electron microscope: New potential biomarker in aquatic environmental monitoring of aluminum and iron contamination

    Science.gov (United States)

    Hidayati, Dewi; Sulaiman, Norela; Othman, Shuhaimi; Ismail, B. S.

    2013-11-01

    Fish scale has the potential to be a rapid biomarker due to its structure and high possibility to come into contact with any pollutant in the aquatic environment. The scale structure consists of osteoblastic cells and other bone materials such as collagen where it is possible to form a molecular complex with heavy metals such as aluminum and iron. Hence, aluminum and iron in water could possibly destroy the scale material and marked as a scale deformation that quantitatively could be analyzed by comparing it to the normal scale structure. Water sampling and fish cage experiment were performed between June and July 2011 in Porong river which represented the water body that has high aluminum and iron contamination. The filtered water samples were preserved and extracted using the acid-mixture procedure prior to measurement of the aluminum and iron concentrations using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), while samples for total suspended solid (TSS) analysis were kept at 4 °C in cool-boxes. The scales were cleaned with sterile water, then dehydrated in 30, 50, 70, and 90% ethanol and dried on filter papers. They were then mounted on an aluminum stub and coated with gold in a sputter coater prior to Scanning Electron Microscope (SEM) observation. According to the SEM analysis, it was found that there were several deformations on the scale samples taken from sites that have high concentrations of aluminum and iron i.e. the increasing number of pits, deformation and decreasing number of spherules and ridges while the control scale exhibited the normal features. However, the site with higher TSS and pH indicated lower aluminum effect. A moderate correlation was found between the number of pits with aluminum (r=0.43) and iron (r=0.41) concentrations. Fish scale deformation using SEM analysis can potentially be a rapid biomarker in aquatic monitoring of aluminum and iron contamination. However, the measurement must be accompanied by pH and

  11. FIREBIRD: A Dual Satellite Mission to Examine the Spatial and Energy Coherence Scales of Radiation Belt Electron Microbursts

    Science.gov (United States)

    Klumpar, D. M.; Spence, H. E.; Larsen, B. A.; Blake, J. B.; Springer, L.; Crew, A. B.; Mosleh, E.; Mashburn, K. W.

    2009-12-01

    FIREBIRD (Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics), a mission under NSF’s “CubeSat-based Science Missions for Space Weather and Atmospheric Research”, will address the broad scientific question: What is the role of microburst electron precipitation in radiation belt dynamics? There are four major candidate processes for losses of relativistic electrons from the outer radiation belt [Millan and Thorne, 2007]: wave-particle interactions with whistler-mode chorus, wave-particle interactions with electromagnetic ion-cyclotron (EMIC) waves, outward radial diffusion to the magnetopause, and loss of adiabaticity on stretched magnetic field lines. FIREBIRD will further investigate the role of whistler-mode chorus, by examining the microburst electron precipitation phenomenon attributed to chorus. Microbursts are thought to be a hallmark of rapid radiation belt losses, possibly removing the entire pre-storm outer zone in a single day [Lorentzen 2001b; O'Brien et al., 2004], yet they are also intimately tied to in-situ acceleration mechanisms. FIREBIRD’s two 1.5U (10 x 10 x 15 cm) CubeSats, each weighing up to 2 kg, will be placed into a common high-inclination bead-on-a-string orbit. The two satellites will remain within ~500 km of one another for six to twelve months, allowing characterization over the spatial scale regime from 10 - 500 km. Each satellite will carry an identical co-aligned pair of solid-state detectors sensitive to electrons from 30 keV to ~3 MeV with 100 msec time resolution. Simultaneous dual measurements provided by the twin FIREBIRD satellites will permit, for the first time, the determination of spatial scales of single microburst events. Along with energy-resolved spectra, these measurements will provide the critically needed answers on the radiation belt loss rate attributed to microbursts. There are three critical questions about relativistic electron microbursts that FIREBIRD can answer: 1) What

  12. Scaling of dynamical decoupling for a single electron spin in nanodiamonds at room temperature

    International Nuclear Information System (INIS)

    Liu, Dong-Qi; Liu, Gang-Qin; Chang, Yan-Chun; Pan, Xin-Yu

    2014-01-01

    Overcoming the spin qubit decoherence is a challenge for quantum science and technology. We investigate the decoherence process in nanodiamonds by Carr–Purcell–Meiboom–Gill (CPMG) technique at room temperature. We find that the coherence time T 2 scales as n γ . The elongation effect of coherence time can be represented by a constant power of the number of pulses n. Considering the filter function of CPMG decoupling sequence as a δ function, the spectrum density of noise has been reconstructed directly from the coherence time measurements and a Lorentzian noise power spectrum model agrees well with the experiment. These results are helpful for the application of nanodiamonds to nanoscale magnetic imaging

  13. Gallium Nitride: A Nano scale Study using Electron Microscopy and Associated Techniques

    International Nuclear Information System (INIS)

    Mohammed Benaissa; Vennegues, Philippe

    2008-01-01

    A complete nano scale study on GaN thin films doped with Mg. This study was carried out using TEM and associated techniques such as HREM, CBED, EDX and EELS. It was found that the presence of triangular defects (of few nanometers in size) within GaN:Mg films were at the origin of unexpected electrical and optical behaviors, such as a decrease in the free hole density at high Mg doping. It is shown that these defects are inversion domains limited with inversion-domains boundaries. (author)

  14. A scanning electron microscopy study of diseased root surfaces conditioned with EDTA gel plus Cetavlon after scaling and root planing.

    Science.gov (United States)

    Martins Júnior, Walter; De Rossi, Andiara; Samih Georges Abi Rached, Ricardo; Rossi, Marcos Antonio

    2011-01-01

    In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.

  15. Pseudopotential-based electron quantum transport: Theoretical formulation and application to nanometer-scale silicon nanowire transistors

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Jingtian, E-mail: jingtian.fang@utdallas.edu; Vandenberghe, William G.; Fu, Bo; Fischetti, Massimo V. [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2016-01-21

    We present a formalism to treat quantum electronic transport at the nanometer scale based on empirical pseudopotentials. This formalism offers explicit atomistic wavefunctions and an accurate band structure, enabling a detailed study of the characteristics of devices with a nanometer-scale channel and body. Assuming externally applied potentials that change slowly along the electron-transport direction, we invoke the envelope-wavefunction approximation to apply the open boundary conditions and to develop the transport equations. We construct the full-band open boundary conditions (self-energies of device contacts) from the complex band structure of the contacts. We solve the transport equations and present the expressions required to calculate the device characteristics, such as device current and charge density. We apply this formalism to study ballistic transport in a gate-all-around (GAA) silicon nanowire field-effect transistor with a body-size of 0.39 nm, a gate length of 6.52 nm, and an effective oxide thickness of 0.43 nm. Simulation results show that this device exhibits a subthreshold slope (SS) of ∼66 mV/decade and a drain-induced barrier-lowering of ∼2.5 mV/V. Our theoretical calculations predict that low-dimensionality channels in a 3D GAA architecture are able to meet the performance requirements of future devices in terms of SS swing and electrostatic control.

  16. A low-noise ac-bridge amplifier for ballistocardiogram measurement on an electronic weighing scale

    International Nuclear Information System (INIS)

    Inan, O T; Kovacs, G T A

    2010-01-01

    Ballistocardiography is a non-invasive technique for evaluating cardiovascular health. This note presents an ac-bridge amplifier for low-noise ballistocardiogram (BCG) recording from a modified weighing scale. The strain gauges in a commercial scale were excited by an ac source—square or sine wave—and the differential output voltage resulting from the BCG was amplified and demodulated synchronously with the excitation waveform. A standard BCG amplifier, with a simple dc-bridge excitation, was also built and the performance was compared to both the square- and sine-wave excited ac-bridge amplifiers. The total input-referred voltage noise (rms) integrated over the relevant BCG bandwidth of 0.3–10 Hz was found to be 30 nV (square wave source) or 25 nV (sine-wave source) for the ac-bridge amplifier and 52 nV for the standard amplifier: an improvement of 4.8 dB or 6 dB, respectively. These correspond to input-referred force noise (rms) values of 5 mN, 4 mN and 8.3 mN. The improvement in SNR was also observed in recorded waveforms from a seated subject whose BCG signal was measured with both dc- and ac-bridge circuits. (note)

  17. Variability of the proton-to-electron mass ratio on cosmological scales

    Science.gov (United States)

    Wendt, M.; Reimers, D.

    2008-10-01

    The search for a possible variation of fundamental physical constants isnewsworthy more than ever. A multitude of methods were developed. So far theonly seemingly significant indication of a cosmological variation existsfor the proton-to-electron massratio as stated by Reinhold et al. [1]. The measuredindication of variation is based on the combined analysis of H2 absorptionsystems in the spectra of Q0405-443 and Q0347-383 at zabs=2.595 and zabs=3.025, respectively. The high resolution data of the latteris reanalyzed in this work to examine the influence of different fittingprocedures and further potential nonconformities. This analysis cannotreproduce the significance achieved by the previous works.

  18. Electronic transport properties of nano-scale Si films: an ab initio study

    Science.gov (United States)

    Maassen, Jesse; Ke, Youqi; Zahid, Ferdows; Guo, Hong

    2010-03-01

    Using a recently developed first principles transport package, we study the electronic transport properties of Si films contacted to heavily doped n-type Si leads. The quantum transport analysis is carried out using density functional theory (DFT) combined with nonequilibrium Green's functions (NEGF). This particular combination of NEGF-DFT allows the investigation of Si films with thicknesses in the range of a few nanometers and lengths up to tens of nanometers. We calculate the conductance, the momentum resolved transmission, the potential profile and the screening length as a function of length, thickness, orientation and surface structure. Moreover, we compare the properties of Si films with and without a top surface passivation by hydrogen.

  19. Electron energy distribution control by fiat: breaking from the conventional flux ratio scaling rules in etch

    Science.gov (United States)

    Ranjan, Alok; Wang, Mingmei; Sherpa, Sonam; Ventzek, Peter

    2015-03-01

    With shrinking critical dimensions, minimizing each of aspect ratio dependent etching (ARDE), bowing, undercut, selectivity, and within die uniformly across a wafer is met by trading off one requirement against another. The problem of trade-offs is especially critical. At the root of the problem is that roles radical flux, ion flux and ion energy play may be both good and bad. Increasing one parameter helps meeting one requirement but hinders meeting the other. Managing process by managing flux ratios and ion energy alone with conventional sources is not adequate because surface chemistry is uncontrollable. At the root of lack of control is that the electron energy distribution function (eedf) has not been controlled. Fortunately the high density surface wave sources control the eedf by fiat. High density surface wave sources are characterized by distinct plasma regions: an active plasma generation region with high electron temperature (Te) and an ionization free but chemistry rich diffusive region (low Te region). Pressure aids is segregating the regions by proving a means for momentum relaxation between the source and downstream region. "Spatial pulsing" allows access to plasma chemistry with reasonably high ion flux, from the active plasma generation region, just above the wafer. Low plasma potential enables precise passivation of surfaces which is critical for atomic layer etch (ALE) or high precision etch where the roles of plasma species can be limited to their purposed roles. High precision etch need not be at the cost of speed and manufacturability. Large ion flux at precisely controlled ion energy with RLSATM realizes fast desorption steps for ALE without compromising process throughput and precision.

  20. Non-isomorphic radial wavenumber dependencies of residual zonal flows in ion and electron Larmor radius scales, and effects of initial parallel flow and electromagnetic potentials in a circular tokamak

    Science.gov (United States)

    Yamagishi, Osamu

    2018-04-01

    Radial wavenumber dependencies of the residual zonal potential for E × B flow in a circular, large aspect ratio tokamak is investigated by means of the collisionless gyrokinetic simulations of Rosenbluth-Hinton (RH) test and the semi-analytic approach using an analytic solution of the gyrokinetic equation Rosenbluth and Hinton (1998 Phys. Rev. Lett. 80 724). By increasing the radial wavenumber from an ion Larmor radius scale {k}r{ρ }i≲ 1 to an electron Larmor radius scale {k}r{ρ }e≲ 1, the well-known level ˜ O[1/(1+1.6{q}2/\\sqrt{r/{R}0})] is retained, while the level remains O(1) when the wavenumber is decreased from the electron to the ion Larmor radius scale, if physically same adiabatic assumption is presumed for species other than the main species that is treated kinetically. The conclusion is not modified by treating both species kinetically, so that in the intermediate scale between the ion and electron Larmor radius scale it seems difficult to determine the level uniquely. The toroidal momentum conservation property in the RH test is also investigated by including an initial parallel flow in addition to the perpendicular flow. It is shown that by taking a balance between the initial parallel flow and perpendicular flows which include both E × B flow and diamagnetic flow in the initial condition, the mechanical toroidal angular momentum is approximately conserved despite the toroidal symmetry breaking due to the finite radial wavenumber zonal modes. Effect of electromagnetic potentials is also investigated. When the electromagnetic potentials are applied initially, fast oscillations which are faster than the geodesic acoustic modes are introduced in the decay phase of the zonal modes. Although the residual level in the long time limit is not modified, this can make the time required to reach the stationary zonal flows longer and may weaken the effectiveness of the turbulent transport suppression by the zonal flows.

  1. Size-dependent giant-magnetoresistance in millimeter scale GaAs/AlGaAs 2D electron devices

    Science.gov (United States)

    Mani, R. G.

    2013-01-01

    Large changes in the electrical resistance induced by the application of a small magnetic field are potentially useful for device-applications. Such Giant Magneto-Resistance (GMR) effects also provide new insights into the physical phenomena involved in the associated electronic transport. This study examines a “bell-shape” negative GMR that grows in magnitude with decreasing temperatures in mm-wide devices fabricated from the high-mobility GaAs/AlGaAs 2-Dimensional Electron System (2DES). Experiments show that the span of this magnetoresistance on the magnetic-field-axis increases with decreasing device width, W, while there is no concurrent Hall resistance, Rxy, correction. A multi-conduction model, including negative diagonal-conductivity, and non-vanishing off-diagonal conductivity, reproduces experimental observations. The results suggest that a size effect in the mm-wide 2DES with mm-scale electron mean-free-paths is responsible for the observed “non-ohmic” size-dependent negative GMR. PMID:24067264

  2. Two-Level Chebyshev Filter Based Complementary Subspace Method: Pushing the Envelope of Large-Scale Electronic Structure Calculations.

    Science.gov (United States)

    Banerjee, Amartya S; Lin, Lin; Suryanarayana, Phanish; Yang, Chao; Pask, John E

    2018-06-12

    We describe a novel iterative strategy for Kohn-Sham density functional theory calculations aimed at large systems (>1,000 electrons), applicable to metals and insulators alike. In lieu of explicit diagonalization of the Kohn-Sham Hamiltonian on every self-consistent field (SCF) iteration, we employ a two-level Chebyshev polynomial filter based complementary subspace strategy to (1) compute a set of vectors that span the occupied subspace of the Hamiltonian; (2) reduce subspace diagonalization to just partially occupied states; and (3) obtain those states in an efficient, scalable manner via an inner Chebyshev filter iteration. By reducing the necessary computation to just partially occupied states and obtaining these through an inner Chebyshev iteration, our approach reduces the cost of large metallic calculations significantly, while eliminating subspace diagonalization for insulating systems altogether. We describe the implementation of the method within the framework of the discontinuous Galerkin (DG) electronic structure method and show that this results in a computational scheme that can effectively tackle bulk and nano systems containing tens of thousands of electrons, with chemical accuracy, within a few minutes or less of wall clock time per SCF iteration on large-scale computing platforms. We anticipate that our method will be instrumental in pushing the envelope of large-scale ab initio molecular dynamics. As a demonstration of this, we simulate a bulk silicon system containing 8,000 atoms at finite temperature, and obtain an average SCF step wall time of 51 s on 34,560 processors; thus allowing us to carry out 1.0 ps of ab initio molecular dynamics in approximately 28 h (of wall time).

  3. Scaling of dynamical decoupling for a single electron spin in nanodiamonds at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dong-Qi; Liu, Gang-Qin; Chang, Yan-Chun; Pan, Xin-Yu, E-mail: xypan@aphy.iphy.ac.cn

    2014-01-01

    Overcoming the spin qubit decoherence is a challenge for quantum science and technology. We investigate the decoherence process in nanodiamonds by Carr–Purcell–Meiboom–Gill (CPMG) technique at room temperature. We find that the coherence time T{sub 2} scales as n{sup γ}. The elongation effect of coherence time can be represented by a constant power of the number of pulses n. Considering the filter function of CPMG decoupling sequence as a δ function, the spectrum density of noise has been reconstructed directly from the coherence time measurements and a Lorentzian noise power spectrum model agrees well with the experiment. These results are helpful for the application of nanodiamonds to nanoscale magnetic imaging.

  4. Femtosecond Planar Electron Beam Source for Micron-Scale Dielectric Wake Field Accelerator. Final report

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2006-01-01

    A new accelerator LACARA is under construction at ATF, Brookhaven National Laboratory. LACARA is to be powered by a 1 TW CO2 laser, and will utilize a 6-T 2-m long solenoidal magnetic field. For a 50 MeV injected electron bunch, LACARA is expected to produce a 100 MeV 1 ps gyrating beam with ∼ 3% energy spread. Beam electrons advance in phase at the laser frequency, executing one cycle each 35 fs. A beam stop with a small off-axis channel will transmit a short beam pulse every optical cycle, thereby producing a train of about 30, 3.5 fs, 1-3 pC microbunches for each laser pulse. One application for this train of microbunches obtained from a LACARA-type device involves focusing a portion of the beam using a magnetic quadrupole into a rectangular cross-section having a narrow dimension of a few microns and a height of a few hundred microns. These microbunches may be injected into a planar dielectric-lined waveguide where cumulative buildup of wake fields can lead to an accelerating gradient > 1 GV/m. This proposed vacuum-based wake field structure is mechanically rigid and capable of accurate microfabrication, factors important in staging a large number of accelerator modules. Furthermore, the accelerating gradients it promises are comparable with those for plasma accelerators. A LACARA unit for preparing suitable bunches at 500 MeV is described. Physics issues are discussed including bunch spreading and transport, bunch shaping, aperture radiation, dielectric breakdown, and bunch stability in the rectangular wake field structure. In appendices to this report, three supporting documents are attached. These include a set of drawings that show the layout of the beam line and optical line for LACARA at ATF-BNL; and two reprints of recent articles published in PRST-AB. The first article describes measurements of the coherent superposition of wake fields that arise from a periodic train of bunches, with supporting analysis. The second article presents theory that

  5. Time dependence, complex scaling, and the calculation of resonances in many-electron systems

    International Nuclear Information System (INIS)

    Nicolaides, C.A.; Beck, D.R.

    1978-01-01

    The theory deals with certain aspects of the formal properties of atomic and molecular highly excited nonstationary states and the problem of calculating their wave functions, energies, and widths. The conceptual framework is a decay theory based on the consistent definition and calculation of the t = 0 localized state, vertical bar psi 0 >. Given this framework, the following topics are treated: The variational calculation of psi 0 and E 0 using a previously published theory that generalized the projection operator approach to many-electron systems. The exact definition of the resonance energy. The possibility of bound states in the continuum. The relation of psi 0 to the resonance (Gamow) function psi and of the Hamiltonian to the rotated Hamiltonian H(theta) based on the notion of perturbation of boundary conditions in the asymptotic region. The variational calculation of real and complex energies employing matrix elements of H and H 2 with square-integrable and resonance functions. The mathematical structure of the time evolution of vertical bar psi 0 > and the possibility of observing nonexponential decays in certain autoionizing states that are very close to the ionization threshold. A many-body theory of atomic and molecular resonances that employs the coordinate rotation method. 107 references

  6. Driver-witness electron beam acceleration in dielectric mm-scale capillaries

    Science.gov (United States)

    Lekomtsev, K.; Aryshev, A.; Tishchenko, A. A.; Shevelev, M.; Lyapin, A.; Boogert, S.; Karataev, P.; Terunuma, N.; Urakawa, J.

    2018-05-01

    We investigated a corrugated mm-scale capillary as a compact accelerating structure in the driver-witness acceleration scheme, and suggested a methodology to measure the acceleration of the witness bunch. The accelerating fields produced by the driver bunch and the energy spread of the witness bunch in a corrugated capillary and in a capillary with a constant inner radius were measured and simulated for both on-axis and off-axis beam propagation. Our simulations predicted a change in the accelerating field structure for the corrugated capillary. Also, an approximately twofold increase of the witness bunch energy gain on the first accelerating cycle was expected for both capillaries for the off-axis beam propagation. These results were confirmed in the experiment, and the maximum measured acceleration of 170 keV /m at 20 pC driver beam charge was achieved for off-axis beam propagation. The driver bunch showed an increase in energy spread of up to 11%, depending on the capillary geometry and beam propagation, with a suppression of the longitudinal energy spread in the witness bunch of up to 15%.

  7. Large-scale separation of single-walled carbon nanotubes by electronic type using click chemistry

    Science.gov (United States)

    Um, Jo-Eun; Song, Sun Gu; Yoo, Pil J.; Song, Changsik; Kim, Woo-Jae

    2018-01-01

    Single-walled carbon nanotubes (SWCNTs) can be either metallic or semiconducting, making their separation critical for applications in nanoelectronics, biomedical materials, and solar cells. Herein, we investigate a novel solution-phase separation method based on click chemistry (azide-alkyne Huisgen cycloaddition) and determine its efficiency and scalability. In this method, metallic SWCNTs in metallic/semiconducting SWCNT mixtures are selectively functionalized with alkyne groups by being reacted with 4-propargyloxybenezenediazonium tetrafluoroborate. Subsequently, silica nanoparticles are functionalized with azide groups and reacted with alkyne-bearing metallic SWCNTs in the SWCNT mixture in the presence of a Cu catalyst. As a result, metallic SWCNTs are anchored on silica powder, whereas non-functionalized semiconducting SWCNTs remain in solution. Low-speed centrifugation effectively removes the silica powder with attached metallic SWCNTs, furnishing a solution of highly pure semiconducting SWCNTs, as confirmed by Raman and UV-vis/near-infrared absorption measurements. This novel separation scheme exhibits the advantage of simultaneously separating both metallic and semiconducting SWCNTs from their mixtures, being cost-effective and therefore applicable at an industrial scale.

  8. Deep learning-based subdivision approach for large scale macromolecules structure recovery from electron cryo tomograms.

    Science.gov (United States)

    Xu, Min; Chai, Xiaoqi; Muthakana, Hariank; Liang, Xiaodan; Yang, Ge; Zeev-Ben-Mordehai, Tzviya; Xing, Eric P

    2017-07-15

    Cellular Electron CryoTomography (CECT) enables 3D visualization of cellular organization at near-native state and in sub-molecular resolution, making it a powerful tool for analyzing structures of macromolecular complexes and their spatial organizations inside single cells. However, high degree of structural complexity together with practical imaging limitations makes the systematic de novo discovery of structures within cells challenging. It would likely require averaging and classifying millions of subtomograms potentially containing hundreds of highly heterogeneous structural classes. Although it is no longer difficult to acquire CECT data containing such amount of subtomograms due to advances in data acquisition automation, existing computational approaches have very limited scalability or discrimination ability, making them incapable of processing such amount of data. To complement existing approaches, in this article we propose a new approach for subdividing subtomograms into smaller but relatively homogeneous subsets. The structures in these subsets can then be separately recovered using existing computation intensive methods. Our approach is based on supervised structural feature extraction using deep learning, in combination with unsupervised clustering and reference-free classification. Our experiments show that, compared with existing unsupervised rotation invariant feature and pose-normalization based approaches, our new approach achieves significant improvements in both discrimination ability and scalability. More importantly, our new approach is able to discover new structural classes and recover structures that do not exist in training data. Source code freely available at http://www.cs.cmu.edu/∼mxu1/software . mxu1@cs.cmu.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  9. Resistivity scaling due to electron surface scattering in thin metal layers

    Science.gov (United States)

    Zhou, Tianji; Gall, Daniel

    2018-04-01

    The effect of electron surface scattering on the thickness-dependent electrical resistivity ρ of thin metal layers is investigated using nonequilibrium Green's function density functional transport simulations. Cu(001) thin films with thickness d =1 -2 nm are used as a model system, employing a random one-monolayer-high surface roughness and frozen phonons to cause surface and bulk scattering, respectively. The zero-temperature resistivity increases from 9.7 ±1.0 μ Ω cm at d =1.99 nm to 18.7 ±2.6 μ Ω cm at d =0.9 0 nm, contradicting the asymptotic T =0 prediction from the classical Fuchs-Sondheimer model. At T =9 00 K, ρ =5.8 ±0.1 μ Ω cm for bulk Cu and ρ =13.4 ±1.1 and 22.5 ±2.4 μ Ω cm for layers with d =1.99 and 0.90 nm, respectively, indicating an approximately additive phonon contribution which, however, is smaller than for bulk Cu or atomically smooth layers. The overall data indicate that the resistivity contribution from surface scattering is temperature-independent and proportional to 1 /d , suggesting that it can be described using a surface-scattering mean-free path λs for 2D transport which is channel-independent and proportional to d . Data fitting indicates λs=4 ×d for the particular simulated Cu(001) surfaces with a one-monolayer-high surface roughness. The 1 /d dependence deviates considerably from previous 1 /d2 predictions from quantum models, indicating that the small-roughness approximation in these models is not applicable to very thin (<2 nm) layers, where the surface roughness is a considerable fraction of d .

  10. RECORDS REACHING RECORDING DATA TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    G. W. L. Gresik

    2013-07-01

    Full Text Available The goal of RECORDS (Reaching Recording Data Technologies is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.

  11. Records Reaching Recording Data Technologies

    Science.gov (United States)

    Gresik, G. W. L.; Siebe, S.; Drewello, R.

    2013-07-01

    The goal of RECORDS (Reaching Recording Data Technologies) is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.

  12. Micron-scale mapping of megagauss magnetic fields using optical polarimetry to probe hot electron transport in petawatt-class laser-solid interactions.

    Science.gov (United States)

    Chatterjee, Gourab; Singh, Prashant Kumar; Robinson, A P L; Blackman, D; Booth, N; Culfa, O; Dance, R J; Gizzi, L A; Gray, R J; Green, J S; Koester, P; Kumar, G Ravindra; Labate, L; Lad, Amit D; Lancaster, K L; Pasley, J; Woolsey, N C; Rajeev, P P

    2017-08-21

    The transport of hot, relativistic electrons produced by the interaction of an intense petawatt laser pulse with a solid has garnered interest due to its potential application in the development of innovative x-ray sources and ion-acceleration schemes. We report on spatially and temporally resolved measurements of megagauss magnetic fields at the rear of a 50-μm thick plastic target, irradiated by a multi-picosecond petawatt laser pulse at an incident intensity of ~10 20 W/cm 2 . The pump-probe polarimetric measurements with micron-scale spatial resolution reveal the dynamics of the magnetic fields generated by the hot electron distribution at the target rear. An annular magnetic field profile was observed ~5 ps after the interaction, indicating a relatively smooth hot electron distribution at the rear-side of the plastic target. This is contrary to previous time-integrated measurements, which infer that such targets will produce highly structured hot electron transport. We measured large-scale filamentation of the hot electron distribution at the target rear only at later time-scales of ~10 ps, resulting in a commensurate large-scale filamentation of the magnetic field profile. Three-dimensional hybrid simulations corroborate our experimental observations and demonstrate a beam-like hot electron transport at initial time-scales that may be attributed to the local resistivity profile at the target rear.

  13. ALMA Telescope Reaches New Heights

    Science.gov (United States)

    2009-09-01

    ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array

  14. SparseMaps—A systematic infrastructure for reduced-scaling electronic structure methods. III. Linear-scaling multireference domain-based pair natural orbital N-electron valence perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yang; Sivalingam, Kantharuban; Neese, Frank, E-mail: Frank.Neese@cec.mpg.de [Max Planck Institut für Chemische Energiekonversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr (Germany); Valeev, Edward F. [Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24014 (United States)

    2016-03-07

    Multi-reference (MR) electronic structure methods, such as MR configuration interaction or MR perturbation theory, can provide reliable energies and properties for many molecular phenomena like bond breaking, excited states, transition states or magnetic properties of transition metal complexes and clusters. However, owing to their inherent complexity, most MR methods are still too computationally expensive for large systems. Therefore the development of more computationally attractive MR approaches is necessary to enable routine application for large-scale chemical systems. Among the state-of-the-art MR methods, second-order N-electron valence state perturbation theory (NEVPT2) is an efficient, size-consistent, and intruder-state-free method. However, there are still two important bottlenecks in practical applications of NEVPT2 to large systems: (a) the high computational cost of NEVPT2 for large molecules, even with moderate active spaces and (b) the prohibitive cost for treating large active spaces. In this work, we address problem (a) by developing a linear scaling “partially contracted” NEVPT2 method. This development uses the idea of domain-based local pair natural orbitals (DLPNOs) to form a highly efficient algorithm. As shown previously in the framework of single-reference methods, the DLPNO concept leads to an enormous reduction in computational effort while at the same time providing high accuracy (approaching 99.9% of the correlation energy), robustness, and black-box character. In the DLPNO approach, the virtual space is spanned by pair natural orbitals that are expanded in terms of projected atomic orbitals in large orbital domains, while the inactive space is spanned by localized orbitals. The active orbitals are left untouched. Our implementation features a highly efficient “electron pair prescreening” that skips the negligible inactive pairs. The surviving pairs are treated using the partially contracted NEVPT2 formalism. A detailed

  15. Examining Agencies' Satisfaction with Electronic Record Management Systems in e-Government: A Large-Scale Survey Study

    Science.gov (United States)

    Hsu, Fang-Ming; Hu, Paul Jen-Hwa; Chen, Hsinchun; Hu, Han-Fen

    While e-government is propelling and maturing steadily, advanced technological capabilities alone cannot guarantee agencies’ realizing the full benefits of the enabling computer-based systems. This study analyzes information systems in e-government settings by examining agencies’ satisfaction with an electronic record management system (ERMS). Specifically, we investigate key satisfaction determinants that include regulatory compliance, job relevance, and satisfaction with support services for using the ERMS. We test our model and the hypotheses in it, using a large-scale survey that involves a total of 1,652 government agencies in Taiwan. Our results show significant effects of regulatory compliance on job relevance and satisfaction with support services, which in turn determine government agencies’ satisfaction with an ERMS. Our data exhibit a reasonably good fit to our model, which can explain a significant portion of the variance in agencies’ satisfaction with an ERMS. Our findings have several important implications to research and practice, which are also discussed.

  16. Theoretical scaling law of coronal magnetic field and electron power-law index in solar microwave burst sources

    Science.gov (United States)

    Huang, Y.; Song, Q. W.; Tan, B. L.

    2018-04-01

    It is first proposed a theoretical scaling law respectively for the coronal magnetic field strength B and electron power-law index δ versus frequency and coronal height in solar microwave burst sources. Based on the non-thermal gyro-synchrotron radiation model (Ramaty in Astrophys. J. 158:753, 1969), B and δ are uniquely solved by the observable optically-thin spectral index and turnover (peak) frequency, the other parameters (plasma density, temperature, view angle, low and high energy cutoffs, etc.) are relatively insensitive to the calculations, thus taken as some typical values. Both of B and δ increase with increasing of radio frequency but with decreasing of coronal height above photosphere, and well satisfy a square or cubic logarithmic fitting.

  17. Atomic-scale observation of structural and electronic orders in the layered compound α-RuCl3

    Science.gov (United States)

    Ziatdinov, M.; Banerjee, A.; Maksov, A.; Berlijn, T.; Zhou, W.; Cao, H. B.; Yan, J.-Q.; Bridges, C. A.; Mandrus, D. G.; Nagler, S. E.; Baddorf, A. P.; Kalinin, S. V.

    2016-12-01

    A pseudospin-1/2 Mott phase on a honeycomb lattice is proposed to host the celebrated two-dimensional Kitaev model which has an elusive quantum spin liquid ground state, and fascinating physics relevant to the development of future templates towards topological quantum bits. Here we report a comprehensive, atomically resolved real-space study by scanning transmission electron and scanning tunnelling microscopies on a novel layered material displaying Kitaev physics, α-RuCl3. Our local crystallography analysis reveals considerable variations in the geometry of the ligand sublattice in thin films of α-RuCl3 that opens a way to realization of a spatially inhomogeneous magnetic ground state at the nanometre length scale. Using scanning tunnelling techniques, we observe the electronic energy gap of ~0.25 eV and intra-unit cell symmetry breaking of charge distribution in individual α-RuCl3 surface layer. The corresponding charge-ordered pattern has a fine structure associated with two different types of charge disproportionation at Cl-terminated surface.

  18. Development of a Laser Driven Photocathode Injector and Femtosecond Scale Laser Electron Synchronization for Next Generation Light Sources

    CERN Document Server

    Le Sage, G P; Ditmire, T R; Rosenzweig, J

    2000-01-01

    A high brightness photoinjector has been developed at LLNL. This injector combined with the 100 TW FALCON laser and the LLNL 100 MeV S-Band RF linac will enable development of a high brightness, femtosecond-scale, tunable, hard x-ray probe for time-resolved material measurements, based on Thomson scattering. Short pulse x-rays enable time-resolved characterization of shock dynamics, and examination of materials under extremes of pressure and temperature. Examples include Equation of State characterization on high-density materials, Crystal disorganization and re-growth in shocked and heated materials, and measurement of short time scale phase transition phenomena. Single shot evaluation, requiring high peak flux, is important for complex experiments such as probing of laser shocked actinides. A low emittance electron beam synchronized with femtosecond accuracy to an intense laser will revolutionize x-ray dynamics studies of materials. This project will lead development of ultrafast x-ray dynamics research on ...

  19. REACH and nanomaterials: current status

    International Nuclear Information System (INIS)

    Alessandrelli, Maria; Di Prospero Fanghella, Paola; Polci, Maria Letizia; Castelli, Stefano; Pettirossi, Flavio

    2015-01-01

    New challenges for regulators are emerging about a specific assessment and appropriate management of the potential risks of nanomaterials. In the framework of European legislation on chemicals, Regulation (EC) No. 1907/2006 REACH aims to ensure the safety of human health and the environment through the collection of information on the physico-chemical characteristics of the substances and on their profile (eco) toxicological and the identification of appropriate risk management linked to 'exposure to these substances without impeding scientific progress and the competitiveness of industry. In order to cover the current shortage of information on the safety of nanomaterials and tackle the acknowledged legal vacuum, are being a rich activities, carried out both by regulators both by stake holders, and discussions on the proposals for adapting the European regulatory framework for chemicals . The European Commission is geared to strengthen the REACH Regulation by means of updates of its annexes. The importance of responding to the regulatory requirements has highlighted the need for cooperation between European organizations, scientists and industries to promote and ensure the safe use of nanomaterials. [it

  20. Cluster observations in the magnetosheath – Part 1: Anisotropies of the wave vector distribution of the turbulence at electron scales

    Directory of Open Access Journals (Sweden)

    A. Mangeney

    2006-12-01

    Full Text Available We analyse the power spectral density δB2 and δE2 of the magnetic and electric fluctuations measured by Cluster 1 (Rumba in the magnetosheath during 23 h, on four different days. The frequency range of the STAFF Spectral Analyser (f=8 Hz to 4 kHz extends from about the lower hybrid frequency, i.e. the electromagnetic (e.m. range, up to about 10 times the proton plasma frequency, i.e. the electrostatic (e.s. range. In the e.m. range, we do not consider the whistler waves, which are not always observed, but rather the underlying, more permanent fluctuations. In this e.m. range, δB2 (at 10 Hz increases strongly while the local angle ΘBV between the magnetic field B and the flow velocity V increases from 0° to 90°. This behaviour, also observed in the solar wind at lower frequencies, is due to the Doppler effect. It can be modelled if we assume that, for the scales ranging from kc/ωpe≃0.3 to 30 (c/ωpe is the electron inertial length, the intensity of the e.m. fluctuations for a wave number k (i varies like k−ν with ν>≃3, (ii peaks for wave vectors k perpendicular to B like |sinθkB|µ with µ>≃100. The shape of the observed variations of δB2 with f and with ΘBV implies that the permanent fluctuations, at these scales, statistically do not obey the dispersion relation for fast/whistler waves or for kinetic Alfvén waves: the fluctuations have a vanishing frequency in the plasma frame, i.e. their phase velocity is negligible with respect to V (Taylor hypothesis. The electrostatic waves around 1 kHz behave differently: δE2 is minimum for ΘBV>≃90°. This can be modelled, still with the Doppler effect, if we assume that, for the scales ranging from k λDe>≃0.1 to 1 (λDe is the Debye length, the intensity of the e.s. fluctuations (i varies like k−ν with ν>≃4, (ii peaks for k parallel to B like |cosθkB|µ with µ>≃100. These e.s. fluctuations may have a vanishing frequency in the plasma frame, or may be ion acoustic

  1. Scale-up of networked HIV treatment in Nigeria: creation of an integrated electronic medical records system.

    Science.gov (United States)

    Chaplin, Beth; Meloni, Seema; Eisen, Geoffrey; Jolayemi, Toyin; Banigbe, Bolanle; Adeola, Juliette; Wen, Craig; Reyes Nieva, Harry; Chang, Charlotte; Okonkwo, Prosper; Kanki, Phyllis

    2015-01-01

    The implementation of PEPFAR programs in resource-limited settings was accompanied by the need to document patient care on a scale unprecedented in environments where paper-based records were the norm. We describe the development of an electronic medical records system (EMRS) put in place at the beginning of a large HIV/AIDS care and treatment program in Nigeria. Databases were created to record laboratory results, medications prescribed and dispensed, and clinical assessments, using a relational database program. A collection of stand-alone files recorded different elements of patient care, linked together by utilities that aggregated data on national standard indicators and assessed patient care for quality improvement, tracked patients requiring follow-up, generated counts of ART regimens dispensed, and provided 'snapshots' of a patient's response to treatment. A secure server was used to store patient files for backup and transfer. By February 2012, when the program transitioned to local in-country management by APIN, the EMRS was used in 33 hospitals across the country, with 4,947,433 adult, pediatric and PMTCT records that had been created and continued to be available for use in patient care. Ongoing trainings for data managers, along with an iterative process of implementing changes to the databases and forms based on user feedback, were needed. As the program scaled up and the volume of laboratory tests increased, results were produced in a digital format, wherever possible, that could be automatically transferred to the EMRS. Many larger clinics began to link some or all of the databases to local area networks, making them available to a larger group of staff members, or providing the ability to enter information simultaneously where needed. The EMRS improved patient care, enabled efficient reporting to the Government of Nigeria and to U.S. funding agencies, and allowed program managers and staff to conduct quality control audits. Copyright © 2014

  2. Reaching for the red planet

    Science.gov (United States)

    David, L

    1996-05-01

    The distant shores of Mars were reached by numerous U.S. and Russian spacecraft throughout the 1960s to mid 1970s. Nearly 20 years have passed since those successful missions which orbited and landed on the Martian surface. Two Soviet probes headed for the planet in July, 1988, but later failed. In August 1993, the U.S. Mars Observer suddenly went silent just three days before it was to enter orbit around the planet and was never heard from again. In late 1996, there will be renewed activity on the launch pads with three probes departing for the red planet: 1) The U.S. Mars Global Surveyor will be launched in November on a Delta II rocket and will orbit the planet for global mapping purposes; 2) Russia's Mars '96 mission, scheduled to fly in November on a Proton launcher, consists of an orbiter, two small stations which will land on the Martian surface, and two penetrators that will plow into the terrain; and finally, 3) a U.S. Discovery-class spacecraft, the Mars Pathfinder, has a December launch date atop a Delta II booster. The mission features a lander and a microrover that will travel short distances over Martian territory. These missions usher in a new phase of Mars exploration, setting the stage for an unprecedented volley of spacecraft that will orbit around, land on, drive across, and perhaps fly at low altitudes over the planet.

  3. Metasurface holograms reaching 80% efficiency.

    Science.gov (United States)

    Zheng, Guoxing; Mühlenbernd, Holger; Kenney, Mitchell; Li, Guixin; Zentgraf, Thomas; Zhang, Shuang

    2015-04-01

    Surfaces covered by ultrathin plasmonic structures--so-called metasurfaces--have recently been shown to be capable of completely controlling the phase of light, representing a new paradigm for the design of innovative optical elements such as ultrathin flat lenses, directional couplers for surface plasmon polaritons and wave plate vortex beam generation. Among the various types of metasurfaces, geometric metasurfaces, which consist of an array of plasmonic nanorods with spatially varying orientations, have shown superior phase control due to the geometric nature of their phase profile. Metasurfaces have recently been used to make computer-generated holograms, but the hologram efficiency remained too low at visible wavelengths for practical purposes. Here, we report the design and realization of a geometric metasurface hologram reaching diffraction efficiencies of 80% at 825 nm and a broad bandwidth between 630 nm and 1,050 nm. The 16-level-phase computer-generated hologram demonstrated here combines the advantages of a geometric metasurface for the superior control of the phase profile and of reflectarrays for achieving high polarization conversion efficiency. Specifically, the design of the hologram integrates a ground metal plane with a geometric metasurface that enhances the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. Because of these advantages, our strategy could be viable for various practical holographic applications.

  4. Adaptive mixed reality rehabilitation improves quality of reaching movements more than traditional reaching therapy following stroke.

    Science.gov (United States)

    Duff, Margaret; Chen, Yinpeng; Cheng, Long; Liu, Sheng-Min; Blake, Paul; Wolf, Steven L; Rikakis, Thanassis

    2013-05-01

    Adaptive mixed reality rehabilitation (AMRR) is a novel integration of motion capture technology and high-level media computing that provides precise kinematic measurements and engaging multimodal feedback for self-assessment during a therapeutic task. We describe the first proof-of-concept study to compare outcomes of AMRR and traditional upper-extremity physical therapy. Two groups of participants with chronic stroke received either a month of AMRR therapy (n = 11) or matched dosing of traditional repetitive task therapy (n = 10). Participants were right handed, between 35 and 85 years old, and could independently reach to and at least partially grasp an object in front of them. Upper-extremity clinical scale scores and kinematic performances were measured before and after treatment. Both groups showed increased function after therapy, demonstrated by statistically significant improvements in Wolf Motor Function Test and upper-extremity Fugl-Meyer Assessment (FMA) scores, with the traditional therapy group improving significantly more on the FMA. However, only participants who received AMRR therapy showed a consistent improvement in kinematic measurements, both for the trained task of reaching to grasp a cone and the untrained task of reaching to push a lighted button. AMRR may be useful in improving both functionality and the kinematics of reaching. Further study is needed to determine if AMRR therapy induces long-term changes in movement quality that foster better functional recovery.

  5. Trial production of low protein irradiated natural rubber latex by low energy electron beam in pilot scale

    International Nuclear Information System (INIS)

    Utama, Marga; Yoshii, F.; Kume, T.

    2006-01-01

    Three importance factors for producing low protein by low energy electron beam (250 keV/10 mA) irradiation in pilot scale (20 liters per bath) with 1,9-nonediol diacrylate (NDA) namely: maturation time of natural rubber latex before irradiation, treatment of irradiated natural rubber latex (INRL) before and after centrifugation, and standard irradiation method has been carried out. The results showed that the optimum irradiation time for producing INRL with 5 phr (part hundred ratio of rubber) of NDA as sensitize agent, and with the rotation speed of agitation 210 rpm (rotation per minutes) was between 20-30 minutes. By using this condition tensile strength of the INRL film was 26 MPa. The maturation of natural rubber latex before irradiation is the key for driving the quality of INRL. Water extractable protein content of INRL after leaching in 1% ammonia solution for 30 minutes at room temperature was around 47 μ/g, and after adding with 1 phr of PVA (poly vinyl alcohol) or 0.1 phr CMC (carboxy methyl cellulose) the water extractable protein content decrease less than 6 μ/g. (author)

  6. Multi-scale modelling of radiation damage in Fe-Cr based on ab initio electronic structure calculations

    International Nuclear Information System (INIS)

    Olsson, Paer

    2004-04-01

    The efficiency of fast neutron reactors, such as for fusion, breeding and transmutation, depend strongly on the neutron radiation resistance of the materials used in the reactors. The binary Fe-Cr alloy, which has many attractive properties in this regard, is the base for the best steels of today which are, however, still not up to the required standards. Therefore, substantial effort has been devoted to finding new materials that can cope with the demands better. Experimental studies must be complemented with extensive theoretical modelling in order to understand the effects that different alloying elements has on the resistance properties of materials. To this end, the first steps of multi-scale modelling has been taken, starting out with ab initio calculations of the electronic structure of the complete concentration range range of the disordered binary Fe-C alloy. The mixing enthalpy of Fe-Cr has been quantitatively predicted and has, together with data from literature, been used in order to fit two sets of interatomic potentials for the purpose of simulating defect evolution with molecular dynamics and kinetic Monte-Carlo codes. These dedicated Fe-Cr alloy potentials are new and represent important additions to the pure element potentials that can be found in literature

  7. Lattice design and beam optics calculations for the new large-scale electron-positron collider FCC-ee

    CERN Document Server

    Haerer, Bastian; Prof. Dr. Schmidt, Ruediger; Dr. Holzer, Bernhard

    Following the recommendations of the European Strategy Group for High Energy Physics, CERN launched the Future Circular Collider Study (FCC) to investigate the feasibility of large-scale circular colliders for future high energy physics research. This thesis presents the considerations taken into account during the design process of the magnetic lattice in the arc sections of the electron-positron version FCC-ee. The machine is foreseen to operate at four different centre-of-mass energies in the range of 90 to 350 GeV. Different beam parameters need to be achieved for every energy, which requires a flexible lattice design in the arc sections. Therefore methods to tune the horizontal beam emittance without re-positioning machine components are implemented. In combination with damping and excitation wigglers a precise adjustment of the emittance can be achieved. A very first estimation of the vertical emittance arising from lattice imperfections is performed. Special emphasis is put on the optimisation of the ...

  8. Multi-scale modelling of radiation damage in Fe-Cr based on ab initio electronic structure calculations

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Paer

    2004-04-01

    The efficiency of fast neutron reactors, such as for fusion, breeding and transmutation, depend strongly on the neutron radiation resistance of the materials used in the reactors. The binary Fe-Cr alloy, which has many attractive properties in this regard, is the base for the best steels of today which are, however, still not up to the required standards. Therefore, substantial effort has been devoted to finding new materials that can cope with the demands better. Experimental studies must be complemented with extensive theoretical modelling in order to understand the effects that different alloying elements has on the resistance properties of materials. To this end, the first steps of multi-scale modelling has been taken, starting out with ab initio calculations of the electronic structure of the complete concentration range range of the disordered binary Fe-C alloy. The mixing enthalpy of Fe-Cr has been quantitatively predicted and has, together with data from literature, been used in order to fit two sets of interatomic potentials for the purpose of simulating defect evolution with molecular dynamics and kinetic Monte-Carlo codes. These dedicated Fe-Cr alloy potentials are new and represent important additions to the pure element potentials that can be found in literature.

  9. High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam

    Science.gov (United States)

    Brown, Jr., R. Malcolm; Barnes, Zack [Austin, TX; Sawatari, Chie [Shizuoka, JP; Kondo, Tetsuo [Kukuoka, JP

    2008-02-26

    The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

  10. Single mode solid state distributed feedback dye laser fabricated by grey scale electron beam lithography on dye doped SU-8 resist

    DEFF Research Database (Denmark)

    Balslev, Søren; Rasmussen, Torben; Shi, Peixiong

    2005-01-01

    We demonstrate grey scale electron beam lithography on functionalized SU-8 resist for fabrication of single mode solid state dye laser devices. The resist is doped with Rhodamine 6G perchlorate and the lasers are based on a first order Bragg grating distributed feedback resonator. The lasers...

  11. Inkjet printing as a roll-to-roll compatible technology for the production of large area electronic devices on a pre-industrial scale

    NARCIS (Netherlands)

    Teunissen, P.; Rubingh, E.; Lammeren, T. van; Abbel, R.J.; Groen, P.

    2014-01-01

    Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet

  12. GRAN SASSO: Reaching the parts that accelerators cannot reach

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    With most of the current experiments at Italy's Gran Sasso Laboratory now well underway, a workshop held earlier this year looked to the future. Gran Sasso was established in the late 1980s to study low rate processes where the laboratory's 1400 metre rock overburden and low natural radioactivity provide an ideal environment. Since then, it has become a major research centre, hosting several international collaborations. The workshop devoted half a day each to four key areas of underground physics, and clearly showed how the non-accelerator approach complements today's accelerator physics achievements. Solar neutrino physics is one of Gran Sasso's main activities, with the Gallex detector half filling one of the laboratory's three experimental halls. Gallex has already made important measurements of the solar neutrino flux, providing first evidence for the proton-proton fusion mechanism which is the solar powerhouse. The next generation experiment, Borexino, will go one step further, measuring the energy distribution of solar neutrinos as well as their flux. The experiment will also be sensitive to neutrino oscillations through its ability to pick out muon and tau neutrinos. Borexino uses boron instead of gallium as the active medium, and is currently in the trial phase. Benchmarking tests with the counter test facility (CTF) have already demonstrated the experiment's feasibility, paving the way for full scale construction. Further ideas for future detectors based on several different active media were also discussed, and a proposal for a helium TPC detector, HELLAZ, was presented. With a threshold of around 240 keV, comparable to that of Gallex and Borexino, HELLAZ would give another handle on neutrinos from the proton-proton reaction, the most abundant source of solar neutrinos. Neutrinoless double beta decay, dark matter searches, and certain low rate processes in nuclear physics all require the quiet, low radiation surroundings

  13. Anomalous Hall effect in ZnxFe3-xO4: Universal scaling law and electron localization below the Verwey transition

    Directory of Open Access Journals (Sweden)

    N. Jedrecy

    2016-08-01

    Full Text Available We show that the well-established universal scaling σxyAHE ∼ σxx1.6 between anomalous Hall and longitudinal conductivities in the low conductivity regime (σxx < 104 Ω−1 cm−1 transforms into the scaling σxyAHE ∼ σxx2 at the onset of strong electron localization. The crossover between the two relations is observed in magnetite-derived ZnxFe3-xO4 thin films where an insulating/hopping regime follows a bad metal/hopping regime below the Verwey transition temperature Tv. Our results demonstrate that electron localization effects come into play in the anomalous Hall effect (AHE modifying significantly the scaling exponent. In addition, the thermal evolution of the anomalous Hall resistivity suggests the existence of spin polarons whose size would decrease below Tv.

  14. When reactors reach old age

    International Nuclear Information System (INIS)

    Fischetti, M.

    1986-01-01

    While the battle over whether to build new nuclear plants has quieted in recent times, a second struggle is shaping up in the United States as reactors approach a new stage of life: retirement. Four decades into the nuclear power age, questions of how best to dismantle and dispose of a nuclear power plant remain largely unanswered. The debates have been mainly academic until now - although reactors have operated for 25 years, decommissioning retired reactors has simply not been fully planned in this country. But the Shippingport Atomic Power Station in Pennsylvania, the first large-scale power reactor to be retired, is now being decommissioned. The work has rekindled the debates in the light of reality. Outside the United States, decommissioning is also being confronted on a new plane. Virtually all groups involved in decommissioning a reactor in the United States - the utility, the Nuclear Regulatory Commission, the U.S. Department of Energy, the U.S. Environmental Protection Agency, state public service commissions, and citizen organizations - agree that for the most part the technology to dismantle and dispose of a reactor safely is available. They disagree, however, on which technical option is the safest or cheapest and on who should pay for dismantlement. And there are further complications: Which regulations must be complied with. How much radiation exposure for workers and the public is acceptable. Even with answers to these questions, uncertainty about where to dispose of the radioactive waste and about how much residual radiation can be left at a former reactor site plagues the architects of decommissioning. This article discusses these questions

  15. Neuroanatomy from Mesoscopic to Nanoscopic Scales: An Improved Method for the Observation of Semithin Sections by High-Resolution Scanning Electron Microscopy.

    Science.gov (United States)

    Rodríguez, José-Rodrigo; Turégano-López, Marta; DeFelipe, Javier; Merchán-Pérez, Angel

    2018-01-01

    Semithin sections are commonly used to examine large areas of tissue with an optical microscope, in order to locate and trim the regions that will later be studied with the electron microscope. Ideally, the observation of semithin sections would be from mesoscopic to nanoscopic scales directly, instead of using light microscopy and then electron microscopy (EM). Here we propose a method that makes it possible to obtain high-resolution scanning EM images of large areas of the brain in the millimeter to nanometer range. Since our method is compatible with light microscopy, it is also feasible to generate hybrid light and electron microscopic maps. Additionally, the same tissue blocks that have been used to obtain semithin sections can later be used, if necessary, for transmission EM, or for focused ion beam milling and scanning electron microscopy (FIB-SEM).

  16. Recent developments in complex scaling

    International Nuclear Information System (INIS)

    Rescigno, T.N.

    1980-01-01

    Some recent developments in the use of complex basis function techniques to study resonance as well as certain types of non-resonant, scattering phenomena are discussed. Complex scaling techniques and other closely related methods have continued to attract the attention of computational physicists and chemists and have now reached a point of development where meaningful calculations on many-electron atoms and molecules are beginning to appear feasible

  17. Operational Reach: Is Current Army Doctrine Adequate?

    National Research Council Canada - National Science Library

    Heintzelman, Scott

    2003-01-01

    The term operational reach, an element of operational design, is new to U.S. Army doctrine. Operational reach is not found in the previous edition of the Army's basic operational doctrine, Field Manual...

  18. Stream Habitat Reach Summary - NCWAP [ds158

    Data.gov (United States)

    California Natural Resource Agency — The Stream Habitat - NCWAP - Reach Summary [ds158] shapefile contains in-stream habitat survey data summarized to the stream reach level. It is a derivative of the...

  19. Removal of the lower hybrid (LH) frequency time scale in test electron simulations of LH-induced tokamak edge electron flow

    Czech Academy of Sciences Publication Activity Database

    Fuchs, Vladimír; Petržílka, Václav; Gunn, J. P.; Goniche, M.

    2002-01-01

    Roč. 52, supplement D (2002), s. 45-50 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : tokamak, edge electrons, lower hybrid antenna Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  20. A comparative scanning electron microscopy study between hand instrument, ultrasonic scaling and erbium doped:Yttirum aluminum garnet laser on root surface: A morphological and thermal analysis

    Directory of Open Access Journals (Sweden)

    Mitul Kumar Mishra

    2013-01-01

    Full Text Available Background and Objectives: Scaling and root planing is one of the most commonly used procedures for the treatment of periodontal diseases. Removal of calculus using conventional hand instruments is incomplete and rather time consuming. In search of more efficient and less difficult instrumentation, investigators have proposed lasers as an alternative or as adjuncts to scaling and root planing. Hence, the purpose of the present study was to evaluate the effectiveness of erbium doped: Yttirum aluminum garnet (Er:YAG laser scaling and root planing alone or as an adjunct to hand and ultrasonic instrumentation. Subjects and Methods: A total of 75 freshly extracted periodontally involved single rooted teeth were collected. Teeth were randomly divided into five treatment groups having 15 teeth each: Hand scaling only, ultrasonic scaling only, Er:YAG laser scaling only, hand scaling + Er:YAG laser scaling and ultrasonic scaling + Er:YAG laser scaling. Specimens were subjected to scanning electron microscopy and photographs were evaluated by three examiners who were blinded to the study. Parameters included were remaining calculus index, loss of tooth substance index, roughness loss of tooth substance index, presence or absence of smear layer, thermal damage and any other morphological damage. Results: Er:YAG laser treated specimens showed similar effectiveness in calculus removal to the other test groups whereas tooth substance loss and tooth surface roughness was more on comparison with other groups. Ultrasonic treated specimens showed better results as compared to other groups with different parameters. However, smear layer presence was seen more with hand and ultrasonic groups. Very few laser treated specimens showed thermal damage and morphological change. Interpretation and Conclusion: In our study, ultrasonic scaling specimen have shown root surface clean and practically unaltered. On the other hand, hand instrument have produced a plane surface

  1. Sparse maps—A systematic infrastructure for reduced-scaling electronic structure methods. II. Linear scaling domain based pair natural orbital coupled cluster theory

    International Nuclear Information System (INIS)

    Riplinger, Christoph; Pinski, Peter; Becker, Ute; Neese, Frank; Valeev, Edward F.

    2016-01-01

    Domain based local pair natural orbital coupled cluster theory with single-, double-, and perturbative triple excitations (DLPNO-CCSD(T)) is a highly efficient local correlation method. It is known to be accurate and robust and can be used in a black box fashion in order to obtain coupled cluster quality total energies for large molecules with several hundred atoms. While previous implementations showed near linear scaling up to a few hundred atoms, several nonlinear scaling steps limited the applicability of the method for very large systems. In this work, these limitations are overcome and a linear scaling DLPNO-CCSD(T) method for closed shell systems is reported. The new implementation is based on the concept of sparse maps that was introduced in Part I of this series [P. Pinski, C. Riplinger, E. F. Valeev, and F. Neese, J. Chem. Phys. 143, 034108 (2015)]. Using the sparse map infrastructure, all essential computational steps (integral transformation and storage, initial guess, pair natural orbital construction, amplitude iterations, triples correction) are achieved in a linear scaling fashion. In addition, a number of additional algorithmic improvements are reported that lead to significant speedups of the method. The new, linear-scaling DLPNO-CCSD(T) implementation typically is 7 times faster than the previous implementation and consumes 4 times less disk space for large three-dimensional systems. For linear systems, the performance gains and memory savings are substantially larger. Calculations with more than 20 000 basis functions and 1000 atoms are reported in this work. In all cases, the time required for the coupled cluster step is comparable to or lower than for the preceding Hartree-Fock calculation, even if this is carried out with the efficient resolution-of-the-identity and chain-of-spheres approximations. The new implementation even reduces the error in absolute correlation energies by about a factor of two, compared to the already accurate

  2. The relationship between small-scale and large-scale ionospheric electron density irregularities generated by powerful HF electromagnetic waves at high latitudes

    Directory of Open Access Journals (Sweden)

    E. D. Tereshchenko

    2006-11-01

    Full Text Available Satellite radio beacons were used in June 2001 to probe the ionosphere modified by a radio beam produced by the EISCAT high-power, high-frequency (HF transmitter located near Tromsø (Norway. Amplitude scintillations and variations of the phase of 150- and 400-MHz signals from Russian navigational satellites passing over the modified region were observed at three receiver sites. In several papers it has been stressed that in the polar ionosphere the thermal self-focusing on striations during ionospheric modification is the main mechanism resulting in the formation of large-scale (hundreds of meters to kilometers nonlinear structures aligned along the geomagnetic field (magnetic zenith effect. It has also been claimed that the maximum effects caused by small-scale (tens of meters irregularities detected in satellite signals are also observed in the direction parallel to the magnetic field. Contrary to those studies, the present paper shows that the maximum in amplitude scintillations does not correspond strictly to the magnetic zenith direction because high latitude drifts typically cause a considerable anisotropy of small-scale irregularities in a plane perpendicular to the geomagnetic field resulting in a deviation of the amplitude-scintillation peak relative to the minimum angle between the line-of-sight to the satellite and direction of the geomagnetic field lines. The variance of the logarithmic relative amplitude fluctuations is considered here, which is a useful quantity in such studies. The experimental values of the variance are compared with model calculations and good agreement has been found. It is also shown from the experimental data that in most of the satellite passes a variance maximum occurs at a minimum in the phase fluctuations indicating that the artificial excitation of large-scale irregularities is minimum when the excitation of small-scale irregularities is maximum.

  3. Comparison of Conjugate Gradient Density Matrix Search and Chebyshev Expansion Methods for Avoiding Diagonalization in Large-Scale Electronic Structure Calculations

    Science.gov (United States)

    Bates, Kevin R.; Daniels, Andrew D.; Scuseria, Gustavo E.

    1998-01-01

    We report a comparison of two linear-scaling methods which avoid the diagonalization bottleneck of traditional electronic structure algorithms. The Chebyshev expansion method (CEM) is implemented for carbon tight-binding calculations of large systems and its memory and timing requirements compared to those of our previously implemented conjugate gradient density matrix search (CG-DMS). Benchmark calculations are carried out on icosahedral fullerenes from C60 to C8640 and the linear scaling memory and CPU requirements of the CEM demonstrated. We show that the CPU requisites of the CEM and CG-DMS are similar for calculations with comparable accuracy.

  4. Environmental stressors afflicting tailwater stream reaches across the United States

    Science.gov (United States)

    Miranda, Leandro E.; Krogman, R. M.

    2014-01-01

    The tailwater is the reach of a stream immediately below an impoundment that is hydrologically, physicochemically and biologically altered by the presence and operation of a dam. The overall goal of this study was to gain a nationwide awareness of the issues afflicting tailwater reaches in the United States. Specific objectives included the following: (i) estimate the percentage of reservoirs that support tailwater reaches with environmental conditions suitable for fish assemblages throughout the year, (ii) identify and quantify major sources of environmental stress in those tailwaters that do support fish assemblages and (iii) identify environmental features of tailwater reaches that determine prevalence of key fish taxa. Data were collected through an online survey of fishery managers. Relative to objective 1, 42% of the 1306 reservoirs included in this study had tailwater reaches with sufficient flow to support a fish assemblage throughout the year. The surface area of the reservoir and catchment most strongly delineated reservoirs maintaining tailwater reaches with or without sufficient flow to support a fish assemblage throughout the year. Relative to objective 2, major sources of environmental stress generally reflected flow variables, followed by water quality variables. Relative to objective 3, zoogeography was the primary factor discriminating fish taxa in tailwaters, followed by a wide range of flow and water quality variables. Results for objectives 1–3 varied greatly among nine geographic regions distributed throughout the continental United States. Our results provide a large-scale view of the effects of reservoirs on tailwater reaches and may help guide research and management needs.

  5. Enhanced mobility in vertically scaled N-polar high-electron-mobility transistors using GaN/InGaN composite channels

    Science.gov (United States)

    Li, Haoran; Wienecke, Steven; Romanczyk, Brian; Ahmadi, Elaheh; Guidry, Matthew; Zheng, Xun; Keller, Stacia; Mishra, Umesh K.

    2018-02-01

    A GaN/InGaN composite channel design for vertically scaled N-polar high-electron-mobility transistor (HEMT) structures is proposed and demonstrated by metal-organic chemical vapor deposition. In a conventional N-polar HEMT structure, as the channel thickness (tch) decreases, the sheet charge density (ns) decreases, the electric field in the channel increases, and the centroid of the two-dimensional electron gas (2DEG) moves towards the back-barrier/channel interface, resulting in stronger scattering and lower electron mobility (μ). In this study, a thin InGaN layer was introduced in-between the channel and the AlGaN cap to increase the 2DEG density and reduce the electric field in the channel and therefore increase the electron mobility. The dependence of μ on the InGaN thickness (tInGaN) and the indium composition (xIn) was investigated for different channel thicknesses. With optimized tInGaN and xIn, significant improvements in electron mobility were observed. For a 6 nm channel HEMT structure, the electron mobility increased from 606 to 1141 cm2/(V.s) when the 6 nm thick pure GaN channel was replaced by the 4 nm GaN/2 nm In0.1Ga0.9N composite channel.

  6. REACH: impact on the US cosmetics industry?

    Science.gov (United States)

    Pouillot, Anne; Polla, Barbara; Polla, Ada

    2009-03-01

    The Registration, Evaluation, Authorization and restriction of Chemicals (REACH) is a recent European regulation on chemical substances meant to protect human health and the environment. REACH imposes the "precautionary principle" where additional data and definitive action are required when uncertainty is identified. The cosmetics industry is only partially concerned by REACH: while the stages of registration and evaluation apply to cosmetics, those of authorization and restriction most likely will not, as cosmetic ingredients are already subject to regulation by various agencies and directives. REACH has potential benefits to the industry including the possibility of reassuring consumers and improving their image of chemicals and cosmetics. However, REACH also has potential disadvantages, mainly with regard to impeding innovation. The American cosmetics industry will be affected by REACH, because all US manufacturers who export substances to Europe will have to fully comply with REACH.

  7. A full-scale prototype for the tracking chambers of the ALICE muon spectrometer. Part II- Electronics. Preamplifier; Read-out prototype

    Energy Technology Data Exchange (ETDEWEB)

    Courtat, P.; Charlet, D.; Lebon, S.; Martin, J.M.; Sellem, R.; Wanlin, E. [CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service d' Electronique Physique; Douet, R.; Harroch, H.; Bimbot, L.; Jouan, D.; Kharmandarian, L.; Le Bornec, Y.; Mac Cormick, M.; Willis, N. [Paris-11 Univ., 91 - Orsay (France). Institut de Physique Nucleaire

    1999-07-01

    A full scale prototype of one module of the first tracking station has already been constructed. It will be equipped with the new read-out electronics proposed for the final chambers. Before integration of the whole chain, tests have been carried out on the individual components in discrete circuit prototypes. The different parts of the chain are described, together with the tests performed. The final version with integrated circuits in then described. (author)

  8. A full-scale prototype for the tracking chambers of the ALICE muon spectrometer. Part II- Electronics. Preamplifier; Read-out prototype

    International Nuclear Information System (INIS)

    Courtat, P.; Charlet, D.; Lebon, S.; Martin, J.M.; Sellem, R.; Wanlin, E.; Douet, R.; Harroch, H.; Bimbot, L.; Jouan, D.; Kharmandarian, L.; Le Bornec, Y.; Mac Cormick, M.; Willis, N.

    1999-01-01

    A full scale prototype of one module of the first tracking station has already been constructed. It will be equipped with the new read-out electronics proposed for the final chambers. Before integration of the whole chain, tests have been carried out on the individual components in discrete circuit prototypes. The different parts of the chain are described, together with the tests performed. The final version with integrated circuits in then described. (author)

  9. Users Guide on Scaled CMOS Reliability: NASA Electronic Parts and Packaging (NEPP) Program Office of Safety and Mission Assurance

    Science.gov (United States)

    White, Mark; Cooper, Mark; Johnston, Allan

    2011-01-01

    Reliability of advanced CMOS technology is a complex problem that is usually addressed from the standpoint of specific failure mechanisms rather than overall reliability of a finished microcircuit. A detailed treatment of CMOS reliability in scaled devices can be found in Ref. 1; it should be consulted for a more thorough discussion. The present document provides a more concise treatment of the scaled CMOS reliability problem, emphasizing differences in the recommended approach for these advanced devices compared to that of less aggressively scaled devices. It includes specific recommendations that can be used by flight projects that use advanced CMOS. The primary emphasis is on conventional memories, microprocessors, and related devices.

  10. Pilot study of synchronization on a femtosecond scale between the electronic gun REGAE and a laser-plasma accelerator

    International Nuclear Information System (INIS)

    Titberidze, Mikheil

    2017-10-01

    Laser wakefield acceleration (LWFA) is a novel technique to accelerate charged particles. Acceleration is achieved by a high-power laser pulse transmitting a gas target where electrons and ions form a strong wakefield with gradients up to 100 GVm -1 . Hence, the size of the laser-plasma accelerator (LPA) is significantly smaller compared to conventional radio frequency (RF) accelerators, because its accelerating gradients are 3 orders of magnitude higher. At present, electron beams generated by LWFA do not satisfy all requirements to make them directly usable for applications such as LPA driven free-electron laser (FEL). Pointing stability and relatively high energy spread are the major limiting factors. Typically, plasma electrons are self-injected in the plasma wake which is created by a high-power laser. There is a lack of control for the injection process and there is no direct access for diagnostics. In order to overcome these challenges and better understand the overall LWFA process, external injection experiments are planned at Deutsches Elektronen-Synchrotron (DESY) in the framework of the Laboratory for Laser and beam-driven plasma Acceleration (LAOLA) collaboration. Thus, well characterized and ultrashort (< 10 fs) electron bunches from the conventional RF accelerator Relativistic Electron Gun for Atomic Exploration (REGAE) will be injected into the laser driven plasma wake. This approach allows to reconstruct and map the plasma wakefield by post diagnosing the injected electron bunches by measuring the energy spectra of it for different injection times. To conduct such a pump-probe type of experiment, synchronization with fs accuracy is required between the electron bunches from REGAE and the high-power driver laser. Two main aspects of the laser synchronization are presented in this thesis. First, a detailed experimental investigation of the conventional, fast photodiode based direct conversion laser-to-RF synchronization setup and its limitations are

  11. Pilot study of synchronization on a femtosecond scale between the electronic gun REGAE and a laser-plasma accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Titberidze, Mikheil

    2017-10-15

    Laser wakefield acceleration (LWFA) is a novel technique to accelerate charged particles. Acceleration is achieved by a high-power laser pulse transmitting a gas target where electrons and ions form a strong wakefield with gradients up to 100 GVm{sup -1}. Hence, the size of the laser-plasma accelerator (LPA) is significantly smaller compared to conventional radio frequency (RF) accelerators, because its accelerating gradients are 3 orders of magnitude higher. At present, electron beams generated by LWFA do not satisfy all requirements to make them directly usable for applications such as LPA driven free-electron laser (FEL). Pointing stability and relatively high energy spread are the major limiting factors. Typically, plasma electrons are self-injected in the plasma wake which is created by a high-power laser. There is a lack of control for the injection process and there is no direct access for diagnostics. In order to overcome these challenges and better understand the overall LWFA process, external injection experiments are planned at Deutsches Elektronen-Synchrotron (DESY) in the framework of the Laboratory for Laser and beam-driven plasma Acceleration (LAOLA) collaboration. Thus, well characterized and ultrashort (< 10 fs) electron bunches from the conventional RF accelerator Relativistic Electron Gun for Atomic Exploration (REGAE) will be injected into the laser driven plasma wake. This approach allows to reconstruct and map the plasma wakefield by post diagnosing the injected electron bunches by measuring the energy spectra of it for different injection times. To conduct such a pump-probe type of experiment, synchronization with fs accuracy is required between the electron bunches from REGAE and the high-power driver laser. Two main aspects of the laser synchronization are presented in this thesis. First, a detailed experimental investigation of the conventional, fast photodiode based direct conversion laser-to-RF synchronization setup and its limitations

  12. Can coronal hole spicules reach coronal temperatures?

    Science.gov (United States)

    Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.

    2011-08-01

    Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures. Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. Results: The analysed three large spicules were found to be comprised of numerous thin spicules that rise, rotate, and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 kms-1. We clearly associated the red- and blue-shifted emissions in transition region lines not only with rotating but also with rising and descending plasmas. Our main result is that these spicules although very large and dynamic, are not present in the spectral lines formed at temperatures above 300 000 K. Conclusions: In this paper we present the analysis of three Ca ii H large spicules that are composed of numerous dynamic thin spicules but appear as macrospicules in lower resolution EUV images. We found no coronal counterpart of these and smaller spicules. We believe that the identification of phenomena that have very different origins as macrospicules is due to the interpretation of the transition region emission, and especially the He ii emission, wherein both chromospheric large spicules and coronal X-ray jets are present. We suggest that the recent observation of spicules in the coronal AIA/SDO 171 Å and 211 Å channels probably comes from the existence of transition region emission there. Movie is available in electronic form at http://www.aanda.org

  13. Electron scattering at interfaces in nano-scale vertical interconnects: A combined experimental and ab initio study

    Science.gov (United States)

    Lanzillo, Nicholas A.; Restrepo, Oscar D.; Bhosale, Prasad S.; Cruz-Silva, Eduardo; Yang, Chih-Chao; Youp Kim, Byoung; Spooner, Terry; Standaert, Theodorus; Child, Craig; Bonilla, Griselda; Murali, Kota V. R. M.

    2018-04-01

    We present a combined theoretical and experimental study on the electron transport characteristics across several representative interface structures found in back-end-of-line interconnect stacks for advanced semiconductor manufacturing: Cu/Ta(N)/Co/Cu and Cu/Ta(N)/Ru/Cu. In particular, we evaluate the impact of replacing a thin TaN barrier with Ta while considering both Co and Ru as wetting layers. Both theory and experiment indicate a pronounced reduction in vertical resistance when replacing TaN with Ta, regardless of whether a Co or Ru wetting layer is used. This indicates that a significant portion of the total vertical resistance is determined by electron scattering at the Cu/Ta(N) interface. The electronic structure of these nano-sized interconnects is analyzed in terms of the atom-resolved projected density of states and k-resolved transmission spectra at the Fermi level. This work further develops a fundamental understanding of electron transport and material characteristics in nano-sized interconnects.

  14. Spin-dependent hot electron transport and nano-scale magnetic imaging of metal/Si structures

    International Nuclear Information System (INIS)

    Kaidatzis, A.

    2008-10-01

    In this work, we experimentally study spin-dependent hot electron transport through metallic multilayers (ML), containing single magnetic layers or 'spin-valve' (SV) tri layers. For this purpose, we have set up a ballistic electron emission microscope (BEEM), a three terminal extension of scanning tunnelling microscopy on metal/semiconductor structures. The implementation of the BEEM requirements into the sample fabrication is described in detail. Using BEEM, the hot electron transmission through the ML's was systematically measured in the energy range 1-2 eV above the Fermi level. By varying the magnetic layer thickness, the spin-dependent hot electron attenuation lengths were deduced. For the materials studied (Co and NiFe), they were compared to calculations and other determinations in the literature. For sub-monolayer thickness, a non uniform morphology was observed, with large transmission variations over sub-nano-metric distances. This effect is not yet fully understood. In the imaging mode, the magnetic configurations of SV's were studied under field, focusing on 360 degrees domain walls in Co layers. The effects of the applied field intensity and direction on the DW structure were studied. The results were compared quantitatively to micro-magnetic calculations, with an excellent agreement. From this, it can be shown that the BEEM magnetic resolution is better than 50 nm. (author)

  15. Overview of 3-year experience with large-scale electronic portal imaging device-based 3-dimensional transit dosimetry

    NARCIS (Netherlands)

    Mijnheer, Ben J.; González, Patrick; Olaciregui-Ruiz, Igor; Rozendaal, Roel A.; van Herk, Marcel; Mans, Anton

    2015-01-01

    To assess the usefulness of electronic portal imaging device (EPID)-based 3-dimensional (3D) transit dosimetry in a radiation therapy department by analyzing a large set of dose verification results. In our institution, routine in vivo dose verification of all treatments is performed by means of 3D

  16. B-side charge separation in bacterial photosynthetic reaction centers: nanosecond time scale electron transfer from HB- to QB.

    Science.gov (United States)

    Kirmaier, Christine; Laible, Philip D; Hanson, Deborah K; Holten, Dewey

    2003-02-25

    We report time-resolved optical measurements of the primary electron transfer reactions in Rhodobacter capsulatus reaction centers (RCs) having four mutations: Phe(L181) --> Tyr, Tyr(M208) --> Phe, Leu(M212) --> His, and Trp(M250) --> Val (denoted YFHV). Following direct excitation of the bacteriochlorophyll dimer (P) to its lowest excited singlet state P, electron transfer to the B-side bacteriopheophytin (H(B)) gives P(+)H(B)(-) in approximately 30% yield. When the secondary quinone (Q(B)) site is fully occupied, P(+)H(B)(-) decays with a time constant estimated to be in the range of 1.5-3 ns. In the presence of excess terbutryn, a competitive inhibitor of Q(B) binding, the observed lifetime of P(+)H(B)(-) is noticeably longer and is estimated to be in the range of 4-8 ns. On the basis of these values, the rate constant for P(+)H(B)(-) --> P(+)Q(B)(-) electron transfer is calculated to be between approximately (2 ns)(-)(1) and approximately (12 ns)(-)(1), making it at least an order of magnitude smaller than the rate constant of approximately (200 ps)(-)(1) for electron transfer between the corresponding A-side cofactors (P(+)H(A)(-) --> P(+)Q(A)(-)). Structural and energetic factors associated with electron transfer to Q(B) compared to Q(A) are discussed. Comparison of the P(+)H(B)(-) lifetimes in the presence and absence of terbutryn indicates that the ultimate (i.e., quantum) yield of P(+)Q(B)(-) formation relative to P is 10-25% in the YFHV RC.

  17. REACH: Evaluation Report and Executive Summary

    Science.gov (United States)

    Sibieta, Luke

    2016-01-01

    REACH is a targeted reading support programme designed to improve reading accuracy and comprehension in pupils with reading difficulties in Years 7 and 8. It is based on research by the Centre for Reading and Language at York and is delivered by specially trained teaching assistants (TAs). This evaluation tested two REACH interventions, one based…

  18. In-Flight Validation of a Pilot Rating Scale for Evaluating Failure Transients in Electronic Flight Control Systems

    Science.gov (United States)

    Kalinowski, Kevin F.; Tucker, George E.; Moralez, Ernesto, III

    2006-01-01

    Engineering development and qualification of a Research Flight Control System (RFCS) for the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A has motivated the development of a pilot rating scale for evaluating failure transients in fly-by-wire flight control systems. The RASCAL RFCS includes a highly-reliable, dual-channel Servo Control Unit (SCU) to command and monitor the performance of the fly-by-wire actuators and protect against the effects of erroneous commands from the flexible, but single-thread Flight Control Computer. During the design phase of the RFCS, two piloted simulations were conducted on the Ames Research Center Vertical Motion Simulator (VMS) to help define the required performance characteristics of the safety monitoring algorithms in the SCU. Simulated failures, including hard-over and slow-over commands, were injected into the command path, and the aircraft response and safety monitor performance were evaluated. A subjective Failure/Recovery Rating (F/RR) scale was developed as a means of quantifying the effects of the injected failures on the aircraft state and the degree of pilot effort required to safely recover the aircraft. A brief evaluation of the rating scale was also conducted on the Army/NASA CH-47B variable stability helicopter to confirm that the rating scale was likely to be equally applicable to in-flight evaluations. Following the initial research flight qualification of the RFCS in 2002, a flight test effort was begun to validate the performance of the safety monitors and to validate their design for the safe conduct of research flight testing. Simulated failures were injected into the SCU, and the F/RR scale was applied to assess the results. The results validate the performance of the monitors, and indicate that the Failure/Recovery Rating scale is a very useful tool for evaluating failure transients in fly-by-wire flight control systems.

  19. Anomalous Hall effect in Zn{sub x}Fe{sub 3-x}O{sub 4}: Universal scaling law and electron localization below the Verwey transition

    Energy Technology Data Exchange (ETDEWEB)

    Jedrecy, N., E-mail: jedrecy@insp.jussieu.fr; Hamieh, M.; Hebert, C.; Escudier, M.; Becerra, L.; Perriere, J. [Institut des Nano Sciences de Paris, UPMC-Sorbonne Universités, CNRS-UMR7588, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2016-08-15

    We show that the well-established universal scaling σ{sub xy}{sup AHE} ∼ σ{sub xx}{sup 1.6} between anomalous Hall and longitudinal conductivities in the low conductivity regime (σ{sub xx} < 10{sup 4} Ω{sup −1} cm{sup −1}) transforms into the scaling σ{sub xy}{sup AHE} ∼ σ{sub xx}{sup 2} at the onset of strong electron localization. The crossover between the two relations is observed in magnetite-derived Zn{sub x}Fe{sub 3-x}O{sub 4} thin films where an insulating/hopping regime follows a bad metal/hopping regime below the Verwey transition temperature T{sub v}. Our results demonstrate that electron localization effects come into play in the anomalous Hall effect (AHE) modifying significantly the scaling exponent. In addition, the thermal evolution of the anomalous Hall resistivity suggests the existence of spin polarons whose size would decrease below T{sub v}.

  20. Pilot-scale test on electron beam treatment of municipal solid waste flue gas with spraying slaked-lime slurry

    International Nuclear Information System (INIS)

    You Osada; Masahiro Sudo; Koichi Hirota

    1995-01-01

    Simultaneous removal of NO x , SO 2 and HCl in flue gas of a municipal solid waste incinerator was studied by using electron beam irradiation technology. The flue gas of around 1000 Nm 3 /h was led to a spray-dryer-type reactor from an inlet of ESP of the municipal waste incinerator by spraying slaked-lime slurry with one or more stoichiometric amount of the pollutants, concentrations of HCl (400 ppm) and SO 2 (50 ppm) decreased almost completely, while concentrations of NO x (100 ppm) were markedly decreased to about 20 ppm by electron beam irradiation with a dose of 10 kGy at 150 o C under spraying slaked-lime slurry of two stoichiometric amounts. The removal of NO x was improved by increasing the dose and the amount of spraying slaked-lime slurry, and by lowering of the irradiation temperature. (Author)

  1. Sparse maps—A systematic infrastructure for reduced-scaling electronic structure methods. I. An efficient and simple linear scaling local MP2 method that uses an intermediate basis of pair natural orbitals

    Energy Technology Data Exchange (ETDEWEB)

    Pinski, Peter; Riplinger, Christoph; Neese, Frank, E-mail: evaleev@vt.edu, E-mail: frank.neese@cec.mpg.de [Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr (Germany); Valeev, Edward F., E-mail: evaleev@vt.edu, E-mail: frank.neese@cec.mpg.de [Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2015-07-21

    In this work, a systematic infrastructure is described that formalizes concepts implicit in previous work and greatly simplifies computer implementation of reduced-scaling electronic structure methods. The key concept is sparse representation of tensors using chains of sparse maps between two index sets. Sparse map representation can be viewed as a generalization of compressed sparse row, a common representation of a sparse matrix, to tensor data. By combining few elementary operations on sparse maps (inversion, chaining, intersection, etc.), complex algorithms can be developed, illustrated here by a linear-scaling transformation of three-center Coulomb integrals based on our compact code library that implements sparse maps and operations on them. The sparsity of the three-center integrals arises from spatial locality of the basis functions and domain density fitting approximation. A novel feature of our approach is the use of differential overlap integrals computed in linear-scaling fashion for screening products of basis functions. Finally, a robust linear scaling domain based local pair natural orbital second-order Möller-Plesset (DLPNO-MP2) method is described based on the sparse map infrastructure that only depends on a minimal number of cutoff parameters that can be systematically tightened to approach 100% of the canonical MP2 correlation energy. With default truncation thresholds, DLPNO-MP2 recovers more than 99.9% of the canonical resolution of the identity MP2 (RI-MP2) energy while still showing a very early crossover with respect to the computational effort. Based on extensive benchmark calculations, relative energies are reproduced with an error of typically <0.2 kcal/mol. The efficiency of the local MP2 (LMP2) method can be drastically improved by carrying out the LMP2 iterations in a basis of pair natural orbitals. While the present work focuses on local electron correlation, it is of much broader applicability to computation with sparse tensors in

  2. Atomic-scale observation of structural and electronic orders in the layered compound ?-RuCl3

    OpenAIRE

    Ziatdinov, M.; Banerjee, A.; Maksov, A.; Berlijn, T.; Zhou, W.; Cao, H. B.; Yan, J.-Q.; Bridges, C. A.; Mandrus, D. G.; Nagler, S. E.; Baddorf, A. P.; Kalinin, S. V.

    2016-01-01

    A pseudospin-1/2 Mott phase on a honeycomb lattice is proposed to host the celebrated two-dimensional Kitaev model which has an elusive quantum spin liquid ground state, and fascinating physics relevant to the development of future templates towards topological quantum bits. Here we report a comprehensive, atomically resolved real-space study by scanning transmission electron and scanning tunnelling microscopies on a novel layered material displaying Kitaev physics, ?-RuCl3. Our local crystal...

  3. Ultra-stable implanted 83Rb/83mKr electron sources for the energy scale monitoring in the KATRIN experiment

    CERN Document Server

    Zboril, M.; Beck, M.; Bonn, J.; Dragoun, O.; Jakubek, J.; Johnston, K.; Kovalik, A.; Otten, E.W.; Schlösser, K.; Slezak, M.; Spalek, A.; Thümmler, T.; Venos, D.; Zemlicka, J.; Weinheimer, C.

    2013-01-01

    The KATRIN experiment aims at the direct model-independent determination of the average electron neutrino mass via the measurement of the endpoint region of the tritium beta decay spectrum. The electron spectrometer of the MAC-E filter type is used, requiring very high stability of the electric filtering potential. This work proves the feasibility of implanted 83Rb/83mKr calibration electron sources which will be utilised in the additional monitor spectrometer sharing the high voltage with the main spectrometer of KATRIN. The source employs conversion electrons of 83mKr which is continuously generated by 83Rb. The K-32 conversion line (kinetic energy of 17.8 keV, natural line width of 2.7 eV) is shown to fulfill the KATRIN requirement of the relative energy stability of +/-1.6 ppm/month. The sources will serve as a standard tool for continuous monitoring of KATRIN's energy scale stability with sub-ppm precision. They may also be used in other applications where the precise conversion lines can be separated fr...

  4. The database for reaching experiments and models.

    Directory of Open Access Journals (Sweden)

    Ben Walker

    Full Text Available Reaching is one of the central experimental paradigms in the field of motor control, and many computational models of reaching have been published. While most of these models try to explain subject data (such as movement kinematics, reaching performance, forces, etc. from only a single experiment, distinct experiments often share experimental conditions and record similar kinematics. This suggests that reaching models could be applied to (and falsified by multiple experiments. However, using multiple datasets is difficult because experimental data formats vary widely. Standardizing data formats promises to enable scientists to test model predictions against many experiments and to compare experimental results across labs. Here we report on the development of a new resource available to scientists: a database of reaching called the Database for Reaching Experiments And Models (DREAM. DREAM collects both experimental datasets and models and facilitates their comparison by standardizing formats. The DREAM project promises to be useful for experimentalists who want to understand how their data relates to models, for modelers who want to test their theories, and for educators who want to help students better understand reaching experiments, models, and data analysis.

  5. Research on the Influence of Weighing Accuracy Caused by the Position of Tension Wheel on the Electronic Belt-Conveyor Scale

    Science.gov (United States)

    Zhang, Kun; Zhang, Hu; Song, Qiuzhi

    2018-01-01

    In this paper, a Single- Idler electronic belt-conveyor scale is the Object of study. The contact force between the belt and the supporting roller is calculated by the finite element analysis software ABAQUS. The relationship between the tension distance of the tension wheel and the contact force between the belt and the weighing roller is obtained. The best stretching distance is found through analysis. And the conclusion which is the weighing error is different at the same stretching distance but the different weight of material is obtained. A compensation mechanism is proposed to improve the weighing accuracy.

  6. Tetragonal fcc-Fe induced by κ -carbide precipitates: Atomic scale insights from correlative electron microscopy, atom probe tomography, and density functional theory

    Science.gov (United States)

    Liebscher, Christian H.; Yao, Mengji; Dey, Poulumi; Lipińska-Chwalek, Marta; Berkels, Benjamin; Gault, Baptiste; Hickel, Tilmann; Herbig, Michael; Mayer, Joachim; Neugebauer, Jörg; Raabe, Dierk; Dehm, Gerhard; Scheu, Christina

    2018-02-01

    Correlative scanning transmission electron microscopy, atom probe tomography, and density functional theory calculations resolve the correlation between elastic strain fields and local impurity concentrations on the atomic scale. The correlative approach is applied to coherent interfaces in a κ -carbide strengthened low-density steel and establishes a tetragonal distortion of fcc-Fe. An interfacial roughness of ˜1 nm and a localized carbon concentration gradient extending over ˜2 -3 nm is revealed, which originates from the mechano-chemical coupling between local strain and composition.

  7. Gate length scaling effect on high-electron mobility transistors devices using AlGaN/GaN and AlInN/AlN/GaN heterostructures.

    Science.gov (United States)

    Liao, S Y; Lu, C C; Chang, T; Huang, C F; Cheng, C H; Chang, L B

    2014-08-01

    Compared to AlGaN/GaN HEMT with 0.15 μm T-gate length, the AlInN/AlN/GaN one exhibits much higher current density and transconductance of 1558 mA/mm at Vd = 2 V and 330 mS/mm, respectively. The high extrinsic ft and fmax of 82 GHz and 70 GHz are extracted from AlInN/AlN/GaN HEMT. Besides, we find that the transconductance roll-off is significant in AlGaN/GaN, but largely improved in AlInN/AlN/GaN HEMT, suggesting that the high carrier density and lattice-matched epitaxial heterostructure is important to reach both large RF output power and high operation frequency, especially for an aggressively gate length scaling.

  8. Multi-scale characteristics of coal structure by x-ray computed tomography (x-ray CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP)

    Science.gov (United States)

    Cai, Ting-ting; Feng, Zeng-chao; Zhou, Dong

    2018-02-01

    It is of great benefit to study the material and structural heterogeneity of coal for better understanding the coalbed methane (CBM) storage and enrichment. In this paper, multi-scale X-ray computed tomography (CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) at multi scales were conducted to thoroughly study the material distribution, heterogeneity, pore development, porosity and permeability of coal. It is suitable and reasonable to divide the testing samples into three structural categories by average density and heterogeneity degree, and the meso structure in the three categories accords with the morphology on SEM images. The pore size distribution and pore development of each subsample cannot be correspondingly related to their respective structure category or morphology due to different observation scales, while the macro pore size development, accumulated macro pore volume and macro pores porosity accord with the meso structure category and morphology information by CT and SEM at the same scale very well. Given the effect of macro pores on permeability and the contribution of micro pores to CBM storage capacity, reservoirs with developed micro pores and macro pores may be the most suitable coal reservoir for CBM exploitation.

  9. Interfacial hydration, dynamics and electron transfer: multi-scale ET modeling of the transient [myoglobin, cytochrome b5] complex.

    Science.gov (United States)

    Keinan, Shahar; Nocek, Judith M; Hoffman, Brian M; Beratan, David N

    2012-10-28

    Formation of a transient [myoglobin (Mb), cytochrome b(5) (cyt b(5))] complex is required for the reductive repair of inactive ferri-Mb to its functional ferro-Mb state. The [Mb, cyt b(5)] complex exhibits dynamic docking (DD), with its cyt b(5) partner in rapid exchange at multiple sites on the Mb surface. A triple mutant (Mb(3M)) was designed as part of efforts to shift the electron-transfer process to the simple docking (SD) regime, in which reactive binding occurs at a restricted, reactive region on the Mb surface that dominates the docked ensemble. An electrostatically-guided brownian dynamics (BD) docking protocol was used to generate an initial ensemble of reactive configurations of the complex between unrelaxed partners. This ensemble samples a broad and diverse array of heme-heme distances and orientations. These configurations seeded all-atom constrained molecular dynamics simulations (MD) to generate relaxed complexes for the calculation of electron tunneling matrix elements (T(DA)) through tunneling-pathway analysis. This procedure for generating an ensemble of relaxed complexes combines the ability of BD calculations to sample the large variety of available conformations and interprotein distances, with the ability of MD to generate the atomic level information, especially regarding the structure of water molecules at the protein-protein interface, that defines electron-tunneling pathways. We used the calculated T(DA) values to compute ET rates for the [Mb(wt), cyt b(5)] complex and for the complex with a mutant that has a binding free energy strengthened by three D/E → K charge-reversal mutations, [Mb(3M), cyt b(5)]. The calculated rate constants are in agreement with the measured values, and the mutant complex ensemble has many more geometries with higher T(DA) values than does the wild-type Mb complex. Interestingly, water plays a double role in this electron-transfer system, lowering the tunneling barrier as well as inducing protein interface

  10. Enhancing US Operational Reach in Southeast Asia

    National Research Council Canada - National Science Library

    Hitchcock, David

    2003-01-01

    .... While this treat continues to exist, the US Pacific Command (PACOM) must also pursue a neat term methodology to expand its operational reach and ability to respond to contingencies throughout the East Asian littoral, especially within Southeast Asia...

  11. Reaching the Overlooked Student in Physical Education

    Science.gov (United States)

    Esslinger, Keri; Esslinger, Travis; Bagshaw, Jarad

    2015-01-01

    This article describes the use of live action role-playing, or "LARPing," as a non-traditional activity that has the potential to reach students who are not interested in traditional physical education.

  12. Compact muon solenoid magnet reaches full field

    CERN Multimedia

    2006-01-01

    Scientist of the U.S. Department of Energy in Fermilab and collaborators of the US/CMS project announced that the world's largest superconducting solenoid magnet has reached full field in tests at CERN. (1 apge)

  13. Scale-invariant puddles in graphene: Geometric properties of electron-hole distribution at the Dirac point.

    Science.gov (United States)

    Najafi, M N; Nezhadhaghighi, M Ghasemi

    2017-03-01

    We characterize the carrier density profile of the ground state of graphene in the presence of particle-particle interaction and random charged impurity in zero gate voltage. We provide detailed analysis on the resulting spatially inhomogeneous electron gas, taking into account the particle-particle interaction and the remote Coulomb disorder on an equal footing within the Thomas-Fermi-Dirac theory. We present some general features of the carrier density probability measure of the graphene sheet. We also show that, when viewed as a random surface, the electron-hole puddles at zero chemical potential show peculiar self-similar statistical properties. Although the disorder potential is chosen to be Gaussian, we show that the charge field is non-Gaussian with unusual Kondev relations, which can be regarded as a new class of two-dimensional random-field surfaces. Using Schramm-Loewner (SLE) evolution, we numerically demonstrate that the ungated graphene has conformal invariance and the random zero-charge density contours are SLE_{κ} with κ=1.8±0.2, consistent with c=-3 conformal field theory.

  14. Modelling Energy Loss Mechanisms and a Determination of the Electron Energy Scale for the CDF Run II W Mass Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Riddick, Thomas [Univ. College London, Bloomsbury (United Kingdom)

    2012-06-15

    The calibration of the calorimeter energy scale is vital to measuring the mass of the W boson at CDF Run II. For the second measurement of the W boson mass at CDF Run II, two independent simulations were developed. This thesis presents a detailed description of the modification and validation of Bremsstrahlung and pair production modelling in one of these simulations, UCL Fast Simulation, comparing to both geant4 and real data where appropriate. The total systematic uncertainty on the measurement of the W boson mass in the W → eve channel from residual inaccuracies in Bremsstrahlung modelling is estimated as 6.2 ±3.2 MeV/c2 and the total systematic uncertainty from residual inaccuracies in pair production modelling is estimated as 2.8± 2.7 MeV=c2. Two independent methods are used to calibrate the calorimeter energy scale in UCL Fast Simulation; the results of these two methods are compared to produce a measurement of the Z boson mass as a cross-check on the accuracy of the simulation.

  15. A study of inelastic electron-phonon interactions on tunneling magnetoresistance of a nano-scale device

    International Nuclear Information System (INIS)

    Modarresi, M.; Roknabadi, M.R.; Shahtahmasbi, N.; Vahedi Fakhrabad, D.; Arabshahi, H.

    2011-01-01

    In this research, we have studied the effect of inelastic electron-phonon interactions on current-voltage characteristic and tunneling magnetoresistance of a polythiophene molecule that is sandwiched between two cobalt electrodes using modified Green's function method as proposed by Walczak. The molecule is described with a modified Su-Schrieffer-Heeger Hamiltonian. The ground state of the molecule is obtained by Hellman-Feynman theorem. Electrodes are described in the wide-band approximation and spin-flip is neglected during conduction. Our calculation results show that with increase in voltage the currents increase and tunneling magnetoresistance decreases. Change in tunneling magnetoresistance due to inelastic interactions is limited in a small bias voltage interval and can be neglected in the other bias voltages. -- Research Highlights: →We investigate the effect of inelastic interaction on transport properties. →Due to inelastic interactions tunneling magnetoresistance decreases. →Decrease in TMR is restricted in a small voltage interval.

  16. Recent Progress in Piezoelectric Conversion and Energy Harvesting Using Nonlinear Electronic Interfaces and Issues in Small Scale Implementation

    Directory of Open Access Journals (Sweden)

    Daniel Guyomar

    2011-06-01

    Full Text Available This paper aims at providing an up-to-date review of nonlinear electronic interfaces for energy harvesting from mechanical vibrations using piezoelectric coupling. The basic principles and the direct application to energy harvesting of nonlinear treatment of the output voltage of the transducers for conversion enhancement will be recalled, and extensions of this approach presented. Latest advances in this field will be exposed, such as the use of intermediate energy tanks for decoupling or initial energy injection for conversion magnification. A comparative analysis of each of these techniques will be performed, highlighting the advantages and drawbacks of the methods, in terms of efficiency, performance under several excitation conditions, complexity of implementation and so on. Finally, a special focus of their implementation in the case of low voltage output transducers (as in the case of microsystems will be presented.

  17. Experiments on the Scaling of Ionization Balance vs. Electron and Radiation Temperature in Non-LTE Gold Plasmas

    International Nuclear Information System (INIS)

    Heeter, R.F.; Hansen, S.B.; Beiersdorfer, P.; Foord, M.E.; Fournier, K.B.; Froula, D.H.; Mackinnon, A.J.; May, M.J.; Schneider, M.B.; Young, B.K.F.

    2004-01-01

    Understanding and predicting the behavior of high-Z non-LTE plasmas is important for developing indirect-drive inertial confinement fusion. Extending earlier work from the Nova laser, we present results from experiments using the Omega laser to study the ionization balance of gold as a function of electron and radiation temperature. In these experiments, gold samples embedded in Be disks expand under direct laser heating to ne ≅ 1021cm-3, with Te varying from 0.8 to 2.5 keV. An additional finite radiation field with effective temperature Tr up to 150 eV is provided by placing the gold Be disks inside truncated 1.2 mm diameter tungsten-coated cylindrical hohlraums with full laser entrance holes. Densities are measured by imaging of plasma expansion. Electron temperatures are diagnosed with either 2ω or 4ω Thomson scattering, and also K-shell spectroscopy of KCl tracers co-mixed with the gold. Hohlraum flux and effective radiation temperature are measured using an absolutely-calibrated multichannel filtered diode array. Spectroscopic measurements of the M-shell gold emission in the 2.9-4 keV spectral range provide ionization balance and charge state distribution information. The spectra show strong variation with Te, strong variation with the applied Tr, at Te below 1.6 keV, and relatively little variation with Tr at higher Te (upwards of 2 keV). We summarize our most recent spectral analyses and discuss emerging and outstanding issues

  18. Do working environment interventions reach shift workers?

    Science.gov (United States)

    Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene; Clausen, Thomas

    2016-01-01

    Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. We used questionnaire data from 5361 female care workers in the Danish eldercare sector. The questions concerned usual working hours, quality of leadership, and self-reported implementation of workplace activities aimed at stress reduction, reorganization of the working hours, and participation in improvements of working procedures or qualifications. Compared with day workers, shift workers were less likely to be reached by workplace interventions. For example, night workers less frequently reported that they had got more flexibility (OR 0.5; 95 % CI 0.3-0.7) or that they had participated in improvements of the working procedures (OR 0.6; 95 % CI 0.5-0.8). Quality of leadership to some extent explained the lack of reach of interventions especially among fixed evening workers. In the light of the evidence of shift workers' stressful working conditions, we suggest that future studies focus on the generalizability of results of the present study and on how to reach this group and meet their needs when designing and implementing workplace interventions.

  19. Computerized implementation of higher-order electron-correlation methods and their linear-scaling divide-and-conquer extensions.

    Science.gov (United States)

    Nakano, Masahiko; Yoshikawa, Takeshi; Hirata, So; Seino, Junji; Nakai, Hiromi

    2017-11-05

    We have implemented a linear-scaling divide-and-conquer (DC)-based higher-order coupled-cluster (CC) and Møller-Plesset perturbation theories (MPPT) as well as their combinations automatically by means of the tensor contraction engine, which is a computerized symbolic algebra system. The DC-based energy expressions of the standard CC and MPPT methods and the CC methods augmented with a perturbation correction were proposed for up to high excitation orders [e.g., CCSDTQ, MP4, and CCSD(2) TQ ]. The numerical assessment for hydrogen halide chains, polyene chains, and first coordination sphere (C1) model of photoactive yellow protein has revealed that the DC-based correlation methods provide reliable correlation energies with significantly less computational cost than that of the conventional implementations. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Dynamic channel adjustments in the Jingjiang Reach of the Middle Yangtze River

    Science.gov (United States)

    Xia, Junqiang; Deng, Shanshan; Lu, Jinyou; Xu, Quanxi; Zong, Quanli; Tan, Guangming

    2016-03-01

    Significant channel adjustments have occurred in the Jingjiang Reach of the Middle Yangtze River, because of the operation of the Three Gorges Project (TGP). The Jingjiang Reach is selected as the study area, covering the Upper Jingjiang Reach (UJR) and Lower Jingjiang Reach (LJR). The reach-scale bankfull channel dimensions in the study reach were calculated annually from 2002 to 2013 by means of a reach-averaged approach and surveyed post-flood profiles at 171 sections. We find from the calculated results that: the reach-scale bankfull widths changed slightly in the UJR and LJR, with the corresponding depths increasing by 1.6 m and 1.0 m the channel adjustments occurred mainly with respect to bankfull depth because of the construction of large-scale bank revetment works, although there were significant bank erosion processes in local regions without the bank protection engineering. The reach-scale bankfull dimensions in the UJR and LJR generally responded to the previous five-year average fluvial erosion intensity during flood seasons, with higher correlations being obtained for the depth and cross-sectional area. It is concluded that these dynamic adjustments of the channel geometry are a direct result of recent human activities such as the TGP operation.

  1. X-ray diffraction and high resolution transmission electron microscopy characterization of intermetallics formed in Fe/Ti nanometer-scale multilayers during thermal annealing

    International Nuclear Information System (INIS)

    Wu, Z.L.; Peng, T.X.; Cao, B.S.; Lei, M.K.

    2009-01-01

    Intermetallics formation in the Fe/Ti nanometer-scale multilayers magnetron-sputtering deposited on Si(100) substrate during thermal annealing at 623-873 K was investigated by using small and wide angle X-ray diffraction and cross-sectional high-resolution transmission electron microscopy. The Fe/Ti nanometer-scale multilayers were constructed with bilayer thickness of 16.2 nm and the sublayer thickness ratio of 1:1. At the annealing temperature of 623 K, intermetallics FeTi were formed by nucleation at the triple joins of α-Fe(Ti)/α-Ti interface and α-Ti grain boundary with an orientational correlation of FeTi(110)//α-Ti(100) and FeTi[001]//α-Ti[001] to adjacent α-Ti grains. The lateral growth of intermetallics FeTi which is dependent on the diffusion path of Ti led to a coalescence into an intermetallic layer. With an increase in the annealing temperature, intermetallics Fe 2 Ti were formed between the intermetallics FeTi and the excess Fe due to the limitation of Fe and Ti atomic concentrations, resulting in the coexistence of intermetallics FeTi and Fe 2 Ti. It was found that the low energy interface as well as the dominant diffusion path constrained the nucleation and growth of intermetallics during interfacial reaction in the nanometer-scale metallic multilayers.

  2. Electron acceleration by turbulent plasmoid reconnection

    Science.gov (United States)

    Zhou, X.; Büchner, J.; Widmer, F.; Muñoz, P. A.

    2018-04-01

    In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury, energetic electrons are often found near current sheets, which hint at electron acceleration by magnetic reconnection. Unfortunately, electron acceleration by reconnection is not well understood yet, in particular, acceleration by turbulent plasmoid reconnection. We have investigated electron acceleration by turbulent plasmoid reconnection, described by MHD simulations, via test particle calculations. In order to avoid resolving all relevant turbulence scales down to the dissipation scales, a mean-field turbulence model is used to describe the turbulence of sub-grid scales and their effects via a turbulent electromotive force (EMF). The mean-field model describes the turbulent EMF as a function of the mean values of current density, vorticity, magnetic field as well as of the energy, cross-helicity, and residual helicity of the turbulence. We found that, mainly around X-points of turbulent reconnection, strongly enhanced localized EMFs most efficiently accelerated electrons and caused the formation of power-law spectra. Magnetic-field-aligned EMFs, caused by the turbulence, dominate the electron acceleration process. Scaling the acceleration processes to parameters of the Hermean magnetotail, electron energies up to 60 keV can be reached by turbulent plasmoid reconnection through the thermal plasma.

  3. Content validity and electronic PRO (ePRO) usability of the Lung Cancer Symptom Scale-Mesothelioma (LCSS-Meso) in mesothelioma patients.

    Science.gov (United States)

    Gelhorn, Heather L; Skalicky, Anne M; Balantac, Zaneta; Eremenco, Sonya; Cimms, Tricia; Halling, Katarina; Hollen, Patricia J; Gralla, Richard J; Mahoney, Martin C; Sexton, Chris

    2018-02-01

    Obtaining qualitative data directly from the patient perspective enhances the content validity of patient-reported outcome (PRO) instruments. The objective of this qualitative study was to evaluate the content validity of the Lung Cancer Symptom Scale for Mesothelioma (LCSS-Meso) and its usability on an electronic device. A cross-sectional methodological study, using a qualitative approach, was conducted among patients recruited from four clinical sites. The primary target population included patients with pleural mesothelioma; data were also collected from patients with peritoneal mesothelioma on an exploratory basis. Semi-structured interviews were conducted consisting of concept elicitation, cognitive interviewing, and evaluation of electronic patient-reported outcome (ePRO) usability. Participants (n = 21) were interviewed in person (n = 9) or by telephone (n = 12); 71% were male with a mean age of 69 years (SD = 14). The most common signs and symptoms experienced by participants with pleural mesothelioma (n = 18) were shortness of breath, fluid build-up, pain, fatigue, coughing, and appetite loss. The most commonly described symptoms for those with peritoneal mesothelioma (n = 4) were bloating, changes in appetite, fatigue, fluid build-up, shortness of breath, and pain. Participants with pleural mesothelioma commonly described symptoms assessed by the LCSS-Meso in language consistent with the questionnaire and a majority understood and easily completed each of the items. The ePRO version was easy to use, and there was no evidence that the electronic formatting changed the way participants responded to the questions. Results support the content validity of the LCSS-Meso and the usability of the electronic format for use in assessing symptoms among patients with pleural mesothelioma.

  4. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng, E-mail: shends@zju.edu.cn

    2013-10-15

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (T{sub Cd} = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required.

  5. Flow analysis of heavy metals in a pilot-scale incinerator for residues from waste electrical and electronic equipment dismantling

    International Nuclear Information System (INIS)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Ding, Wei-Xu; Shen, Dong-Sheng

    2013-01-01

    Highlights: • Cu, Zn, Pb, and Ni are enriched in bottom ash from WEEE dismantling residues. • The heavy metal residual fraction restricts transfer in the incinerator. • Pre-treatment to remove heavy metals from WEEE residues would reduce emissions. -- Abstract: The large amount of residues generated from dismantling waste electrical and electronic equipment (WEEE) results in a considerable environmental burden. We used material flow analysis to investigate heavy metal behavior in an incineration plant in China used exclusively to incinerate residues from WEEE dismantling. The heavy metals tested were enriched in the bottom and fly ashes after incineration. However, the contents of heavy metals in the bottom ash, fly ash and exhaust gas do not have a significant correlation with that of the input waste. The evaporation and recondensation behavior of heavy metals caused their contents to differ with air pollution control equipment because of the temperature difference during gas venting. Among the heavy metals tested, Cd had the strongest tendency to transfer during incineration (T Cd = 69.5%) because it had the lowest melting point, followed by Cu, Ni, Pb and Zn. The exchangeable and residual fractions of heavy metals increased substantially in the incineration products compared with that of the input residues. Although the mass of residues from WEEE dismantling can be reduced by 70% by incineration, the safe disposal of the metal-enriched bottom and fly ashes is still required

  6. Contribution to the modelling and multi-scale numerical simulation of kinetic electron transport in hot plasma

    International Nuclear Information System (INIS)

    Mallet, J.

    2012-01-01

    This research thesis stands at the crossroad of plasma physics, numerical analysis and applied mathematics. After an introduction presenting the problematic and previous works, the author recalls some basis of classical kinetic models for plasma physics (collisionless kinetic theory and Vlasov equation, collisional kinetic theory with the non-relativistic Maxwell-Fokker-Plansk system) and describes the fundamental properties of the collision operators such as conservation laws, entropy dissipation, and so on. He reports the improvement of a deterministic numerical method to solve the non-relativistic Vlasov-Maxwell system coupled with Fokker-Planck-Landau type operators. The efficiency of each high order scheme is compared. The evolution of the hot spot is studied in the case of thermonuclear reactions in the centre of the pellet in a weakly collisional regime. The author focuses on the simulation of the kinetic electron collisional transport in inertial confinement fusion (ICF) between the laser absorption zone and the ablation front. A new approach is then introduced to reduce the huge computation time obtained with kinetic models. In a last chapter, the kinetic continuous equation in spherical domain is described and a new model is chosen for collisions in order to preserve collision properties

  7. Guiding Warfare to Reach Sustainable Peace

    DEFF Research Database (Denmark)

    Vestenskov, David; Drewes, Line

    The conference report Guiding Warfare to Reach Sustainable Peace constitutes the primary outcome of the conference It is based on excerpts from the conference presenters and workshop discussions. Furthermore, the report contains policy recommendations and key findings, with the ambition of develo......The conference report Guiding Warfare to Reach Sustainable Peace constitutes the primary outcome of the conference It is based on excerpts from the conference presenters and workshop discussions. Furthermore, the report contains policy recommendations and key findings, with the ambition...... of developing best practices in the education and implementation of IHL in capacity building of security forces....

  8. Do working environment interventions reach shift workers?

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene

    2016-01-01

    PURPOSE: Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether...... the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. METHODS: We used questionnaire data from 5361 female care workers in the Danish eldercare sector...

  9. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  10. Reaching Reluctant Students: Insights from Torey Hayden.

    Science.gov (United States)

    Marlowe, Mike

    1999-01-01

    Illustrates principles of reaching students who fight or avoid adults by using examples drawn from the writings of Torey Hayden. Presents ten concepts that can serve as guidelines for building relationships with resistant children, and gives excerpts from Hayden's works to illustrate each concept. Demonstrates how books provide teachers with…

  11. ATLAS Barrel Toroid magnet reached nominal field

    CERN Multimedia

    2006-01-01

     On 9 November the barrel toroid magnet reached its nominal field of 4 teslas, with an electrical current of 21 000 amperes (21 kA) passing through the eight superconducting coils as shown on this graph

  12. Comparative analyses of population-scale phenomic data in electronic medical records reveal race-specific disease networks

    Science.gov (United States)

    Glicksberg, Benjamin S.; Li, Li; Badgeley, Marcus A.; Shameer, Khader; Kosoy, Roman; Beckmann, Noam D.; Pho, Nam; Hakenberg, Jörg; Ma, Meng; Ayers, Kristin L.; Hoffman, Gabriel E.; Dan Li, Shuyu; Schadt, Eric E.; Patel, Chirag J.; Chen, Rong; Dudley, Joel T.

    2016-01-01

    Motivation: Underrepresentation of racial groups represents an important challenge and major gap in phenomics research. Most of the current human phenomics research is based primarily on European populations; hence it is an important challenge to expand it to consider other population groups. One approach is to utilize data from EMR databases that contain patient data from diverse demographics and ancestries. The implications of this racial underrepresentation of data can be profound regarding effects on the healthcare delivery and actionability. To the best of our knowledge, our work is the first attempt to perform comparative, population-scale analyses of disease networks across three different populations, namely Caucasian (EA), African American (AA) and Hispanic/Latino (HL). Results: We compared susceptibility profiles and temporal connectivity patterns for 1988 diseases and 37 282 disease pairs represented in a clinical population of 1 025 573 patients. Accordingly, we revealed appreciable differences in disease susceptibility, temporal patterns, network structure and underlying disease connections between EA, AA and HL populations. We found 2158 significantly comorbid diseases for the EA cohort, 3265 for AA and 672 for HL. We further outlined key disease pair associations unique to each population as well as categorical enrichments of these pairs. Finally, we identified 51 key ‘hub’ diseases that are the focal points in the race-centric networks and of particular clinical importance. Incorporating race-specific disease comorbidity patterns will produce a more accurate and complete picture of the disease landscape overall and could support more precise understanding of disease relationships and patient management towards improved clinical outcomes. Contacts: rong.chen@mssm.edu or joel.dudley@mssm.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27307606

  13. Comparative analyses of population-scale phenomic data in electronic medical records reveal race-specific disease networks.

    Science.gov (United States)

    Glicksberg, Benjamin S; Li, Li; Badgeley, Marcus A; Shameer, Khader; Kosoy, Roman; Beckmann, Noam D; Pho, Nam; Hakenberg, Jörg; Ma, Meng; Ayers, Kristin L; Hoffman, Gabriel E; Dan Li, Shuyu; Schadt, Eric E; Patel, Chirag J; Chen, Rong; Dudley, Joel T

    2016-06-15

    Underrepresentation of racial groups represents an important challenge and major gap in phenomics research. Most of the current human phenomics research is based primarily on European populations; hence it is an important challenge to expand it to consider other population groups. One approach is to utilize data from EMR databases that contain patient data from diverse demographics and ancestries. The implications of this racial underrepresentation of data can be profound regarding effects on the healthcare delivery and actionability. To the best of our knowledge, our work is the first attempt to perform comparative, population-scale analyses of disease networks across three different populations, namely Caucasian (EA), African American (AA) and Hispanic/Latino (HL). We compared susceptibility profiles and temporal connectivity patterns for 1988 diseases and 37 282 disease pairs represented in a clinical population of 1 025 573 patients. Accordingly, we revealed appreciable differences in disease susceptibility, temporal patterns, network structure and underlying disease connections between EA, AA and HL populations. We found 2158 significantly comorbid diseases for the EA cohort, 3265 for AA and 672 for HL. We further outlined key disease pair associations unique to each population as well as categorical enrichments of these pairs. Finally, we identified 51 key 'hub' diseases that are the focal points in the race-centric networks and of particular clinical importance. Incorporating race-specific disease comorbidity patterns will produce a more accurate and complete picture of the disease landscape overall and could support more precise understanding of disease relationships and patient management towards improved clinical outcomes. rong.chen@mssm.edu or joel.dudley@mssm.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

  14. Monitoring Space Radiation Hazards with the Responsive Environmental Assessment Commercially Hosted (REACH) Project

    Science.gov (United States)

    Mazur, J. E.; Guild, T. B.; Crain, W.; Crain, S.; Holker, D.; Quintana, S.; O'Brien, T. P., III; Kelly, M. A.; Barnes, R. J.; Sotirelis, T.

    2017-12-01

    The Responsive Environmental Assessment Commercial Hosting (REACH) project uses radiation dosimeters on a commercial satellite constellation in low Earth orbit to provide unprecedented spatial and time sampling of space weather radiation hazards. The spatial and time scales of natural space radiation environments coupled with constraints for the hosting accommodation drove the instrumentation requirements and the plan for the final orbital constellation. The project has delivered a total of thirty two radiation dosimeter instruments for launch with each instrument containing two dosimeters with different passive shielding and electronic thresholds to address proton-induced single-event effects, vehicle charging, and total ionizing dose. There are two REACH instruments currently operating with four more planned for launch by the time of the 2017 meeting. Our aim is to field a long-lived system of highly-capable radiation detectors to monitor the hazards of single-event effects, total ionizing dose, and spacecraft charging with maximized spatial coverage and with minimal time latency. We combined a robust detection technology with a commercial satellite hosting to produce a new demonstration for satellite situational awareness and for other engineering and science applications.

  15. Large scale use of brazing and high temperature brazing for the fabrication of the 6.4 km long vacuum system of the HERA electron storage ring

    International Nuclear Information System (INIS)

    Ballion, R.; Boster, J.; Giesske, W.; Hartwig, H.; Jagnow, D.; Kouptsidis, J.; Pape, R.; Prohl, W.; Schumann, G.; Schwartz, M.; Iversen, K.; Mucklenbeck, J.

    1989-01-01

    The 6.4 km long vacuum system for electrons in the large storage ring HERA at Hamburg consists of about 1,400 components having lengths between .14 and 12 m. The vacuum components are mainly made from variously shaped tubes of the copper alloy CuSn2. This alloy combines sufficient mechanical strength with the high thermal conductivity needed to remove the 6 MW dissipated power of the synchrotron-light. The vacuum components consist additionally of parts made from stainless steel such as flanges, chambers for pumps, beam monitors, etc. All of these parts are connected in a vacuum tight manner and on a large scale by using brazing and high temperature brazing both in a vacuum or in a reducing gas atmosphere. (orig.)

  16. Monitoring the energy scale of KATRIN with conversion electrons of a solid {sup 83m}Kr source as nuclear standard

    Energy Technology Data Exchange (ETDEWEB)

    Schloesser, Klaus [IKP, Karlsruher Institut fuer Technologie (Germany); Collaboration: KATRIN-Collaboration

    2016-07-01

    For KATRIN to be able to achieve the desired sensitivity of 200 meV/c{sup 2} for the effective electron neutrino mass, it is of crucial importance that the energy scale of the main spectrometer (18.6 keV) is under control within +/-60 mV at any given time over the planned measurement time of approximately 5 years. Besides conventional high voltage dividers and high precision volt meters, a nuclear standard will be deployed additionally in a separate spectrometer of MAC-E filter type. The filter electrodes of both spectrometers are connected galvanically. For permanent and continuous monitoring an easy to use ion implanted source containing the noble gas {sup 83m}Kr was developed and qualified for HV monitoring at the ppm level in the 30 kV regime. This talk presents the methods applied and the achievements made.

  17. Use of electronic healthcare records in large-scale simple randomized trials at the point of care for the documentation of value-based medicine.

    Science.gov (United States)

    van Staa, T-P; Klungel, O; Smeeth, L

    2014-06-01

    A solid foundation of evidence of the effects of an intervention is a prerequisite of evidence-based medicine. The best source of such evidence is considered to be randomized trials, which are able to avoid confounding. However, they may not always estimate effectiveness in clinical practice. Databases that collate anonymized electronic health records (EHRs) from different clinical centres have been widely used for many years in observational studies. Randomized point-of-care trials have been initiated recently to recruit and follow patients using the data from EHR databases. In this review, we describe how EHR databases can be used for conducting large-scale simple trials and discuss the advantages and disadvantages of their use. © 2014 The Association for the Publication of the Journal of Internal Medicine.

  18. Nanometer-scale, quantitative composition mappings of InGaN layers from a combination of scanning transmission electron microscopy and energy dispersive x-ray spectroscopy

    International Nuclear Information System (INIS)

    Pantzas, K; Voss, P L; Ougazzaden, A; Patriarche, G; Largeau, L; Mauguin, O; Troadec, D; Gautier, S; Moudakir, T; Suresh, S

    2012-01-01

    Using elastic scattering theory we show that a small set of energy dispersive x-ray spectroscopy (EDX) measurements is sufficient to experimentally evaluate the scattering function of electrons in high-angle annular dark field scanning transmission microscopy (HAADF-STEM). We then demonstrate how to use this function to transform qualitative HAADF-STEM images of InGaN layers into precise, quantitative chemical maps of the indium composition. The maps obtained in this way combine the resolution of HAADF-STEM and the chemical precision of EDX. We illustrate the potential of such chemical maps by using them to investigate nanometer-scale fluctuations in the indium composition and their impact on the growth of epitaxial InGaN layers. (paper)

  19. Power Flow Distribution Strategy for Improved Power Electronics Energy Efficiency in Battery Storage Systems: Development and Implementation in a Utility-Scale System

    Directory of Open Access Journals (Sweden)

    Michael Schimpe

    2018-03-01

    Full Text Available Utility-scale battery storage systems typically consist of multiple smaller units contributing to the overall power dispatch of the system. Herein, the power distribution among these units is analyzed and optimized to operate the system with increased energy efficiency. To improve the real-life storage operation, a holistic system model for battery storage systems has been developed that enables a calculation of the energy efficiency. A utility-scale Second-Life battery storage system with a capacity of 3.3 MWh/3 MW is operated and evaluated in this work. The system is in operation for the provision of primary control reserve in combination with intraday trading for controlling the battery state of charge. The simulation model is parameterized with the system data. Results show that losses in power electronics dominate. An operational strategy improving the energy efficiency through an optimized power flow distribution within the storage system is developed. The power flow distribution strategy is based on the reduction of the power electronics losses at no-load/partial-load by minimizing their in-operation time. The simulation derived power flow distribution strategy is implemented in the real-life storage system. Field-test measurements and analysis prove the functionality of the power flow distribution strategy and reveal the reduction of the energy throughput of the units by 7%, as well as a significant reduction of energy losses in the units by 24%. The cost savings for electricity over the system’s lifetime are approximated to 4.4% of its investment cost.

  20. Amplified Erosion above Waterfalls and Oversteepened Bedrock Reaches

    Science.gov (United States)

    Haviv, I.; Enzel, Y.; Whipple, K. X.; Zilberman, E.; Stone, J.; Matmon, A.; Fifield, K. L.

    2005-12-01

    Although waterfalls are abundant along steep bedrock channels, none of the conventional erosion laws can predict incision at the lip of a waterfall where flow is non-uniform and bed slope can be vertical. Considering the expected increase in flow velocity and shear stress at the lip of a vertical waterfall we determine erosion amplification at a waterfall lip as: Elip/Enormal= (1+0.4/Fr2)3n, where Fr is the Froude number and n ranges between 0.5-1.7. This amplification expression suggests that erosion at the lip could be as much as 2-5 times higher than normally expected in a setting with identical hydraulic geometry. It also demonstrates that a freefall is expected to amplify upstream incision rates even when the flow approaching the waterfall is highly supercritical. Utilizing this erosion amplification expression in numerical simulations in conjunction with a standard detachment-limited incision model we demonstrate its impact on reach-scale morphology above waterfalls. These simulations indicate that amplified erosion at the lip of a waterfall can trigger the formation of an oversteepened reach whose length is longer than the flow acceleration zone, provided incision velocity (Vi) at the edge of the flow acceleration zone is higher than the retreat velocity of the waterfall face. Such an oversteepened reach is expected to be more pronounced when Vi increases with increasing slope. The simulations also suggest that oversteepening can eventually lead to quasi steady-state gradients upstream from a waterfall provided Vi decreases with increasing slope. Flow acceleration above waterfalls can thus account, at least partially, for oversteepened bedrock reaches that are prevalent above waterfalls. Such reaches have been reported for the escarpments of southeast Australia, western Dead Sea, and at Niagara Falls. Using the cosmogenic isotope 36Cl we demonstrate that Vi upstream of a waterfall at the Dead Sea western escarpment is high enough for freefall

  1. Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

    Science.gov (United States)

    Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

    2015-08-19

    The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

  2. Improving exposure scenario definitions within REACH

    DEFF Research Database (Denmark)

    Lee, Jihyun; Pizzol, Massimo; Thomsen, Marianne

    In recent years, the paradigm of chemical management system has changed from being toxicity oriented and media based to being risk oriented and receptor based. This trend is evident not only regarding environmental quality standards, but also for industrial chemical regulations. Political...... instruments to support a precautionary chemicals management system and to protect receptor’s health have also been increasing. Since 2007, the European Union adopted REACH (the Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals): REACH makes industry responsible for assessing...... and managing the risks posed by industrial chemicals and providing appropriate safety information to their users (EC, 2007). However, to ensure a high level of protection of human health and the environment, there is a need to consider ‘aggregate exposure’ including background exposures from environment which...

  3. Does workplace health promotion reach shift workers?

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Garde, Anne Helene; Clausen, Thomas

    2015-01-01

    OBJECTIVES: One reason for health disparities between shift and day workers may be that workplace health promotion does not reach shift workers to the same extent as it reaches day workers. This study aimed to investigate the association between shift work and the availability of and participation...... in workplace health promotion. METHODS: We used cross-sectional questionnaire data from a large representative sample of all employed people in Denmark. We obtained information on the availability of and participation in six types of workplace health promotion. We also obtained information on working hours, ie......). RESULTS: In the general working population, fixed evening and fixed night workers, and employees working variable shifts including night work reported a higher availability of health promotion, while employees working variable shifts without night work reported a lower availability of health promotion...

  4. Olefins and chemical regulation in Europe: REACH.

    Science.gov (United States)

    Penman, Mike; Banton, Marcy; Erler, Steffen; Moore, Nigel; Semmler, Klaus

    2015-11-05

    REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the European Union's chemical regulation for the management of risk to human health and the environment (European Chemicals Agency, 2006). This regulation entered into force in June 2007 and required manufacturers and importers to register substances produced in annual quantities of 1000 tonnes or more by December 2010, with further deadlines for lower tonnages in 2013 and 2018. Depending on the type of registration, required information included the substance's identification, the hazards of the substance, the potential exposure arising from the manufacture or import, the identified uses of the substance, and the operational conditions and risk management measures applied or recommended to downstream users. Among the content developed to support this information were Derived No-Effect Levels or Derived Minimal Effect Levels (DNELs/DMELs) for human health hazard assessment, Predicted No Effect Concentrations (PNECs) for environmental hazard assessment, and exposure scenarios for exposure and risk assessment. Once registered, substances may undergo evaluation by the European Chemicals Agency (ECHA) or Member State authorities and be subject to requests for additional information or testing as well as additional risk reduction measures. To manage the REACH registration and related activities for the European olefins and aromatics industry, the Lower Olefins and Aromatics REACH Consortium was formed in 2008 with administrative and technical support provided by Penman Consulting. A total of 135 substances are managed by this group including 26 individual chemical registrations (e.g. benzene, 1,3-butadiene) and 13 categories consisting of 5-26 substances. This presentation will describe the content of selected registrations prepared for 2010 in addition to the significant post-2010 activities. Beyond REACH, content of the registrations may also be relevant to other European activities, for

  5. Performance reach in the LHC for 2012

    International Nuclear Information System (INIS)

    Arduini, G.

    2012-01-01

    Based on the 2011 experience and Machine Development study results, the performance reach of the LHC with 25 and 50 ns beams will be addressed for operation at 3.5 and 4 TeV. The possible scrubbing scenarios and potential intensity limitations resulting from vacuum, heating will be taken into account wherever possible. The paper mainly covers the performance of the two high luminosity regions in IR1 and IR5. (author)

  6. The German REACH Congress 2016: a workshop report.

    Science.gov (United States)

    Reihlen, Antonia; Jepsen, Dirk; Broschinski, Lutz; Luch, Andreas; Schulte, Agnes

    2018-03-01

    In October 2016, the German REACH Congress was held at the German Federal Institute for Risk Assessment (BfR) in Berlin. Here, the associated improvement made in the fields of consumer protection and the progress in and experiences gained from the implementation of the authorisation procedure were discussed. Several speakers from EU institutions, German authorities, industry, and civil society organisations were invited to present their views. There was a shared consensus that REACH contributes to the advancement of consumer protection against chemical risks, mainly because more and higher quality information on substance-related hazards and potential exposures becomes available. In addition, risk management measures, particularly regarding restrictions on uses, scale down consumer exposures to chemicals. Opportunities for improvements identified at the congress include the quality of registration dossiers and the management of and communication on substances of very high concern (SVHC) that may be present in consumer articles. Although regarded as being in an early implementation phase, the authorisation process was generally found to be operational and progressing well. Criticism was expressed with regard to the consistency of authorisation decisions and the costs and uncertainties related to authorisation applications. Consumer protection legislation consists of several legal provisions which are interlinked. The congress participants agreed that REACH is an important element of this legal framework as it enhances and complements other legal provisions.

  7. Riparian Vegetation Mapping Along the Hanford Reach

    International Nuclear Information System (INIS)

    FOGWELL, T.W.

    2003-01-01

    During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY2002

  8. Long-reach manipulators for decommissioning

    International Nuclear Information System (INIS)

    Webster, D.A.; Challinor, S.F.

    1993-01-01

    A survey of redundant facilities at Sellafield has identified that in many cases the conventional means of deploying remote handling equipment are not appropriate and that novel means must be employed. However, decommissioning is not a value adding activity and so expensive one off designs must be avoided. The paper will describe BNFL's approach to the synthesis from proprietary parts of a manipulator which can lift 3 te at a horizontal reach of over 5 metres and yet can still perform the dextrous manipulation necessary to remove small items. It will also cover the development of the manipulator control systems and the adaption of commercial handtools to be manipulator friendly. (author)

  9. Luminosity performance reach after LS1

    International Nuclear Information System (INIS)

    Herr, W.

    2012-01-01

    Based on past experience (2010/2011), in particular expected limitations from beam-beam effects, and taking into account the expected beam quality from the LHC injectors, the peak and integrated luminosity at top energy is discussed for different scenarios (e.g. bunch spacing, beta*). In particular it will be shown which are the key parameters to reach the nominal luminosity and it is also shown that peak luminosities two times larger than nominal (or higher) are possible. Possible test in 2012 are discussed

  10. City Reach Code Technical Support Document

    Energy Technology Data Exchange (ETDEWEB)

    Athalye, Rahul A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chen, Yan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Jian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Bing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Frankel, Mark [New Buildings Inst., Portland, OR (United States); Lyles, Mark [New Buildings Inst., Portland, OR (United States)

    2017-10-31

    This report describes and analyzes a set of energy efficiency measures that will save 20% energy over ASHRAE Standard 90.1-2013. The measures will be used to formulate a Reach Code for cities aiming to go beyond national model energy codes. A coalition of U.S. cities together with other stakeholders wanted to facilitate the development of voluntary guidelines and standards that can be implemented in stages at the city level to improve building energy efficiency. The coalition's efforts are being supported by the U.S. Department of Energy via Pacific Northwest National Laboratory (PNNL) and in collaboration with the New Buildings Institute.

  11. Livestock First Reached Southern Africa in Two Separate Events.

    Science.gov (United States)

    Sadr, Karim

    2015-01-01

    After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which 'infiltrated' livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa.

  12. Can donated media placements reach intended audiences?

    Science.gov (United States)

    Cooper, Crystale Purvis; Gelb, Cynthia A; Chu, Jennifer; Polonec, Lindsey

    2013-09-01

    Donated media placements for public service announcements (PSAs) can be difficult to secure, and may not always reach intended audiences. Strategies used by the Centers for Disease Control and Prevention's (CDC) Screen for Life: National Colorectal Cancer Action Campaign (SFL) to obtain donated media placements include producing a diverse mix of high-quality PSAs, co-branding with state and tribal health agencies, securing celebrity involvement, monitoring media trends to identify new distribution opportunities, and strategically timing the release of PSAs. To investigate open-ended recall of PSAs promoting colorectal cancer screening, CDC conducted 12 focus groups in three U.S. cities with men and women either nearing age 50 years, when screening is recommended to begin, or aged 50-75 years who were not in compliance with screening guidelines. In most focus groups, multiple participants recalled exposure to PSAs promoting colorectal cancer screening, and most of these individuals reported having seen SFL PSAs on television, in transit stations, or on the sides of public buses. Some participants reported exposure to SFL PSAs without prompting from the moderator, as they explained how they learned about the disease. Several participants reported learning key campaign messages from PSAs, including that colorectal cancer screening should begin at age 50 years and screening can find polyps so they can be removed before becoming cancerous. Donated media placements can reach and educate mass audiences, including millions of U.S. adults who have not been screened appropriately for colorectal cancer.

  13. Efficacy of REACH Forgiveness across cultures.

    Science.gov (United States)

    Lin, Yin; Worthington, Everett L; Griffin, Brandon J; Greer, Chelsea L; Opare-Henaku, Annabella; Lavelock, Caroline R; Hook, Joshua N; Ho, Man Yee; Muller, Holly

    2014-09-01

    This study investigates the efficacy of the 6-hour REACH Forgiveness intervention among culturally diverse undergraduates. Female undergraduates (N = 102) and foreign extraction (46.2%) and domestic (43.8%) students in the United States were randomly assigned to immediate treatment or waitlist conditions. Treatment efficacy and the effect of culture on treatment response were assessed using measures of emotional and decisional forgiveness across 3 time periods. Students in the treatment condition reported greater improvement in emotional forgiveness, but not decisional forgiveness, relative to those in the waitlist condition. Gains were maintained at a 1-week follow-up. Although culture did not moderate the effect of treatment, a main effect of culture on emotional forgiveness and marginally significant interaction effect of culture on decisional forgiveness were found. The REACH Forgiveness intervention was efficacious for college students from different cultural backgrounds when conducted in the United States. However, some evidence may warrant development of culturally adapted forgiveness interventions. © 2014 Wiley Periodicals, Inc.

  14. Auto-Thermal Reforming Using Mixed Ion-Electronic Conducting Ceramic Membranes for a Small-Scale H2 Production Plant

    Directory of Open Access Journals (Sweden)

    Vincenzo Spallina

    2015-03-01

    Full Text Available The integration of mixed ionic electronic conducting (MIEC membranes for air separation in a small-to-medium scale unit for H2 production (in the range of 650–850 Nm3/h via auto-thermal reforming of methane has been investigated in the present study. Membranes based on mixed ionic electronic conducting oxides such as Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF give sufficiently high oxygen fluxes at temperatures above 800 °C with high purity (higher than 99%. Experimental results of membrane permeation tests are presented and used for the reactor design with a detailed reactor model. The assessment of the H2 plant has been carried out for different operating conditions and reactor geometry and an energy analysis has been carried out with the flowsheeting software Aspen Plus, including also the turbomachines required for a proper thermal integration. A micro-gas turbine is integrated in the system in order to supply part of the electricity required in the system. The analysis of the system shows that the reforming efficiency is in the range of 62%–70% in the case where the temperature at the auto-thermal reforming membrane reactor (ATR-MR is equal to 900 °C. When the electric consumption and the thermal export are included the efficiency of the plant approaches 74%–78%. The design of the reactor has been carried out using a reactor model linked to the Aspen flowsheet and the results show that with a larger reactor volume the performance of the system can be improved, especially because of the reduced electric consumption. From this analysis it has been found that for a production of about 790 Nm3/h pure H2, a reactor with a diameter of 1 m and length of 1.8 m with about 1500 membranes of 2 cm diameter is required.

  15. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zweiacker, K., E-mail: Kai@zweiacker.org; Liu, C.; Wiezorek, J. M. K. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 648 Benedum Hall, 3700 OHara Street, Pittsburgh, Pennsylvania 15261 (United States); McKeown, J. T.; LaGrange, T.; Reed, B. W.; Campbell, G. H. [Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States)

    2016-08-07

    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of the metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ∼1.3 m s{sup −1} to ∼2.5 m s{sup −1} during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s{sup −1} have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. Using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.

  16. Finding Multi-scale Connectivity in Our Geospace Observational System: A New Perspective for Total Electron Content Data Through Network Analysis

    Science.gov (United States)

    McGranaghan, R. M.; Mannucci, A. J.; Verkhoglyadova, O. P.; Malik, N.

    2017-12-01

    How do we evolve beyond current traditional methods in order to innovate into the future? In what disruptive innovations will the next frontier of space physics and aeronomy (SPA) be grounded? We believe the answer to these compelling, yet equally challenging, questions lies in a shift of focus: from a narrow, field-specific view to a radically inclusive, interdisciplinary new modus operandi at the intersection of SPA and the information and data sciences. Concretely addressing these broader themes, we present results from a novel technique for knowledge discovery in the magnetosphere-ionosphere-thermosphere (MIT) system: complex network analysis (NA). We share findings from the first NA of ionospheric total electron content (TEC) data, including hemispheric and interplanetary magnetic field clock angle dependencies [1]. Our work shows that NA complements more traditional approaches for the investigation of TEC structure and dynamics, by both reaffirming well-established understanding, giving credence to the method, and identifying new connections, illustrating the exciting potential. We contextualize these new results through a discussion of the potential of data-driven discovery in the MIT system when innovative data science techniques are embraced. We address implications and potentially disruptive data analysis approaches for SPA in terms of: 1) the future of the geospace observational system; 2) understanding multi-scale phenomena; and 3) machine learning. [1] McGranaghan, R. M., A. J. Mannucci, O. Verkhoglyadova, and N. Malik (2017), Finding multiscale connectivity in our geospace observational system: Network analysis of total electron content, J. Geophys. Res. Space Physics, 122, doi:10.1002/2017JA024202.

  17. Reaching the global target to reduce stunting: an investment framework.

    Science.gov (United States)

    Shekar, Meera; Kakietek, Jakub; D'Alimonte, Mary R; Rogers, Hilary E; Eberwein, Julia Dayton; Akuoku, Jon Kweku; Pereira, Audrey; Soe-Lin, Shan; Hecht, Robert

    2017-06-01

    Childhood stunting, being short for one's age, has life-long consequences for health, human capital and economic growth. Being stunted in early childhood is associated with slower cognitive development, reduced schooling attainment and adult incomes decreased by 5-53%. The World Health Assembly has endorsed global nutrition targets including one to reduce the number of stunted children under five by 40% by 2025. The target has been included in the Sustainable Development Goals (SDG target 2.2). This paper estimates the cost of achieving this target and develops scenarios for generating the necessary financing. We focus on a key intervention package for stunting (KIPS) with strong evidence of effectiveness. Annual scale-up costs for the period of 2016-25 were estimated for a sample of 37 high burden countries and extrapolated to all low and middle income countries. The Lives Saved Tool was used to model the impact of the scale-up on stunting prevalence. We analysed data on KIPS budget allocations and expenditure by governments, donors and households to derive a global baseline financing estimate. We modelled two financing scenarios, a 'business as usual', which extends the current trends in domestic and international financing for nutrition through 2025, and another that proposes increases in financing from all sources under a set of burden-sharing rules. The 10-year financial need to scale up KIPS is US$49.5 billion. Under 'business as usual', this financial need is not met and the global stunting target is not reached. To reach the target, current financing will have to increase from US$2.6 billion to US$7.4 billion a year on average. Reaching the stunting target is feasible but will require large coordinated investments in KIPS and a supportive enabling environment. The example of HIV scale-up over 2001-11 is instructive in identifying the factors that could drive such a global response to childhood stunting. © The Author 2017. Published by Oxford University

  18. Riparian Vegetation Mapping Along the Hanford Reach

    Energy Technology Data Exchange (ETDEWEB)

    FOGWELL, T.W.

    2003-07-11

    During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY

  19. Reach and get capability in a computing environment

    Science.gov (United States)

    Bouchard, Ann M [Albuquerque, NM; Osbourn, Gordon C [Albuquerque, NM

    2012-06-05

    A reach and get technique includes invoking a reach command from a reach location within a computing environment. A user can then navigate to an object within the computing environment and invoke a get command on the object. In response to invoking the get command, the computing environment is automatically navigated back to the reach location and the object copied into the reach location.

  20. Unified communication to reach vulnerable mothers.

    Science.gov (United States)

    Tezcan, B; Von Rege, I; Henkson, H; Oteng-Ntim, E

    2011-01-01

    The feasibility of using a mobile text to reach vulnerable patient groups was assessed in this study. A total of 121 pregnant or postnatal women were randomly asked to complete a questionnaire. The questionnaire was given to them in the antenatal clinic, postnatal ward, antenatal ward or in the day assessment unit at St Thomas' Hospital, London. The forms were collected and analysed using an Excel database. The results of this survey show that mobile technology is readily available for 97% of the obstetric population. In mothers from vulnerable groups and in mothers from deprived areas, 61% possessed 3rd generation mobile technology. The majority of mothers surveyed wanted their care supplemented by the use of their mobile phones.

  1. Validity of an Interactive Functional Reach Test.

    Science.gov (United States)

    Galen, Sujay S; Pardo, Vicky; Wyatt, Douglas; Diamond, Andrew; Brodith, Victor; Pavlov, Alex

    2015-08-01

    Videogaming platforms such as the Microsoft (Redmond, WA) Kinect(®) are increasingly being used in rehabilitation to improve balance performance and mobility. These gaming platforms do not have built-in clinical measures that offer clinically meaningful data. We have now developed software that will enable the Kinect sensor to assess a patient's balance using an interactive functional reach test (I-FRT). The aim of the study was to test the concurrent validity of the I-FRT and to establish the feasibility of implementing the I-FRT in a clinical setting. The concurrent validity of the I-FRT was tested among 20 healthy adults (mean age, 25.8±3.4 years; 14 women). The Functional Reach Test (FRT) was measured simultaneously by both the Kinect sensor using the I-FRT software and the Optotrak Certus(®) 3D motion-capture system (Northern Digital Inc., Waterloo, ON, Canada). The feasibility of implementing the I-FRT in a clinical setting was assessed by performing the I-FRT in 10 participants with mild balance impairments recruited from the outpatient physical therapy clinic (mean age, 55.8±13.5 years; four women) and obtaining their feedback using a NASA Task Load Index (NASA-TLX) questionnaire. There was moderate to good agreement between FRT measures made by the two measurement systems. The greatest agreement between the two measurement system was found with the Kinect sensor placed at a distance of 2.5 m [intraclass correlation coefficient (2,k)=0.786; PNASA/TLX questionnaire. FRT measures made using the Kinect sensor I-FRT software provides a valid clinical measure that can be used with the gaming platforms.

  2. Atomic force microscopy and scanning electron microscopy evaluation of efficacy of scaling and root planing using magnification: A randomized controlled clinical study

    Directory of Open Access Journals (Sweden)

    Ranjana Mohan

    2013-01-01

    Full Text Available Aim: A randomized controlled clinical study was undertaken to evaluate the effectiveness of scaling and root planing (SRP by using Magnifying Loupes (ML and dental operating microscope (DOM. Materials and Methods: A total of 90 human teeth scheduled for extraction from 18 patients aged between 25 and 65 years suffering from generalized chronic severe periodontitis were randomly assigned to three treatment groups. Group 1 consisted SRP performed without using magnification (unaided, Group 2-SRP with ML and Group 3-SRP with DOM. Following extractions, samples were prepared for (i evaluation of surface topography by atomic force microscopy, (ii presence of smear layer, debris by scanning electron microscopy (iii elemental analysis by energy dispersive X-ray analysis. Data was subjected to statistical analysis using analysis of variance, post-hoc (Tukey-HSD and Chi-square test. Results: Statistically significant (P < 0.001 difference was found among the different treatment groups. Group 3 was the best while Group 1 was the least effective technique for SRP. Order of efficacy in terms of the surface was found to be - Palatal < Lingual < Distal ≅ Mesial < Buccal. Efficiency in mandibular to maxillary teeth was found to be significant (P < 0.05, also anterior to posterior teeth (P < 0.05. Conclusion: Magnification tools significantly enhance the efficacy of supragingival and subgingival SRP.

  3. Local unitary transformation method for large-scale two-component relativistic calculations. II. Extension to two-electron Coulomb interaction.

    Science.gov (United States)

    Seino, Junji; Nakai, Hiromi

    2012-10-14

    The local unitary transformation (LUT) scheme at the spin-free infinite-order Douglas-Kroll-Hess (IODKH) level [J. Seino and H. Nakai, J. Chem. Phys. 136, 244102 (2012)], which is based on the locality of relativistic effects, has been extended to a four-component Dirac-Coulomb Hamiltonian. In the previous study, the LUT scheme was applied only to a one-particle IODKH Hamiltonian with non-relativistic two-electron Coulomb interaction, termed IODKH/C. The current study extends the LUT scheme to a two-particle IODKH Hamiltonian as well as one-particle one, termed IODKH/IODKH, which has been a real bottleneck in numerical calculation. The LUT scheme with the IODKH/IODKH Hamiltonian was numerically assessed in the diatomic molecules HX and X(2) and hydrogen halide molecules, (HX)(n) (X = F, Cl, Br, and I). The total Hartree-Fock energies calculated by the LUT method agree well with conventional IODKH/IODKH results. The computational cost of the LUT method is reduced drastically compared with that of the conventional method. In addition, the LUT method achieves linear-scaling with respect to the system size and a small prefactor.

  4. Influence of the "surface effect" on the segregation parameters of S in Fe(100): A multi-scale modelling and Auger Electron Spectroscopy study

    Science.gov (United States)

    Barnard, P. E.; Terblans, J. J.; Swart, H. C.

    2015-12-01

    The article takes a new look at the process of atomic segregation by considering the influence of surface relaxation on the segregation parameters; the activation energy (Q), segregation energy (ΔG), interaction parameter (Ω) and the pre-exponential factor (D0). Computational modelling, namely Density Functional Theory (DFT) and the Modified Darken Model (MDM) in conjunction with Auger Electron Spectroscopy (AES) was utilized to study the variation of the segregation parameters for S in the surface region of Fe(100). Results indicate a variation in each of the segregation parameters as a function of the atomic layer under consideration. Values of the segregation parameters varied more dramatically as the surface layer is approached, with atomic layer 2 having the largest deviations in comparison to the bulk values. This atomic layer had the highest Q value and formed the rate limiting step for the segregation of S towards the Fe(100) surface. It was found that the segregation process is influenced by two sets of segregation parameters, those of the surface region formed by atomic layer 2, and those in the bulk material. This article is the first to conduct a full scale investigation on the influence of surface relaxation on segregation and labelled it the "surface effect".

  5. Particle-in-cell Simulations with Kinetic Electrons

    International Nuclear Information System (INIS)

    Lewandowski, J.L.V.

    2004-01-01

    A new scheme, based on an exact separation between adiabatic and nonadiabatic electron responses, for particle-in-cell (PIC) simulations of drift-type modes is presented. The (linear and nonlinear) elliptic equations for the scalar fields are solved using a multi-grid solver. The new scheme yields linear growth rates in excellent agreement with theory and it is shown to conserve energy well into the nonlinear regime. It is also demonstrated that simulations with few electrons are reliable and accurate, suggesting that large-scale, PIC simulations with electron dynamics in toroidal geometry (e.g., tokamaks and stellarators plasmas) are within reach of present-day massively parallel supercomputers

  6. Toxicological comments to the discussion about REACH.

    Science.gov (United States)

    Greim, Helmut; Arand, Michael; Autrup, Herman; Bolt, Hermann M; Bridges, James; Dybing, Erik; Glomot, Rémi; Foa, Vito; Schulte-Hermann, Rolf

    2006-03-01

    It is the ultimate goal of the intended REACH process (Registration, Evaluation and Authorization of Chemicals) of the European Union to identify substances of hazardous properties and to evaluate the risks of human and environmental exposure. During the last few months there has been a controversial discussion as to what extent in vitro studies and consideration of structure activity relationship provide sufficient information to waive repeated exposure studies. Industry as well as certain regulatory agencies or NGOs support this approach and propose that repeated dose studies may only be required beyond 100 t/a. From a toxicological point of view it has to be stressed that this discussion primarily considers the cost reduction and protection of animals, whereas protection of human health and the environment are secondary. In vitro studies only allow identification of specific hazardous properties which can be detected by the specific test system. Moreover, appropriate information on the dose response of adverse effects, identification of thresholds and NOELs that are essential for risk characterization cannot be obtained from these studies. Consequently, identification of all relevant hazardous properties and endpoints of adverse effects can only be determined in the intact animal by repeated dose studies such as 28-day or 90-day studies. In the absence of such information the hazard identification is incomplete and there is no basis for appropriate risk assessment of human exposure. Thus, any waiving of repeated dose studies in animals bears the probability of unforeseen effects in case of acute or continuous human exposure. From this the undersigning European Toxicologists conclude: 1. The intention of REACH is to identify hazardous properties in order that a reliable risk assessment can be made and measures taken to deal with chemicals posing a significant risk. 2. The recent debate has centered on ways in which the well established in vivo methods for risk

  7. ESO telbib: Linking In and Reaching Out

    Science.gov (United States)

    Grothkopf, U.; Meakins, S.

    2015-04-01

    Measuring an observatory's research output is an integral part of its science operations. Like many other observatories, ESO tracks scholarly papers that use observational data from ESO facilities and uses state-of-the-art tools to create, maintain, and further develop the Telescope Bibliography database (telbib). While telbib started out as a stand-alone tool mostly used to compile lists of papers, it has by now developed into a multi-faceted, interlinked system. The core of the telbib database is links between scientific papers and observational data generated by the La Silla Paranal Observatory residing in the ESO archive. This functionality has also been deployed for ALMA data. In addition, telbib reaches out to several other systems, including ESO press releases, the NASA ADS Abstract Service, databases at the CDS Strasbourg, and impact scores at Altmetric.com. We illustrate these features to show how the interconnected telbib system enhances the content of the database as well as the user experience.

  8. Using New Media to Reach Broad Audiences

    Science.gov (United States)

    Gay, P. L.

    2008-06-01

    The International Year of Astronomy New Media Working Group (IYA NMWG) has a singular mission: To flood the Internet with ways to learn about astronomy, interact with astronomers and astronomy content, and socially network with astronomy. Within each of these areas, we seek to build lasting programs and partnerships that will continue beyond 2009. Our weapon of choice is New Media. It is often easiest to define New Media by what it is not. Television, radio, print and their online redistribution of content are not New Media. Many forms of New Media start as user provided content and content infrastructures that answer that individual's creative whim in a way that is adopted by a broader audience. Classic examples include Blogs and Podcasts. This media is typically distributed through content specific websites and RSS feeds, which allow syndication. RSS aggregators (iTunes has audio and video aggregation abilities) allow subscribers to have content delivered to their computers automatically when they connect to the Internet. RSS technology is also being used in such creative ways as allowing automatically updating Google-maps that show the location of someone with an intelligent GPS system, and in sharing 100 word microblogs from anyone (Twitters) through a single feed. In this poster, we outline how the IYA NMWG plans to use New Media to reach target primary audiences of astronomy enthusiasts, image lovers, and amateur astronomers, as well as secondary audiences, including: science fiction fans, online gamers, and skeptics.

  9. Media perspective - new opportunities for reaching audiences

    Science.gov (United States)

    Haswell, Katy

    2007-08-01

    The world of media is experiencing a period of extreme and rapid change with the rise of internet television and the download generation. Many young people no longer watch standard TV. Instead, they go on-line, talking to friends and downloading pictures, videos, music clips to put on their own websites and watch/ listen to on their laptops and mobile phones. Gone are the days when TV controllers determined what you watched and when you watched it. Now the buzzword is IPTV, Internet Protocol Television, with companies such as JOOST offering hundreds of channels on a wide range of subjects, all of which you can choose to watch when and where you wish, on your high-def widescreen with stereo surround sound at home or on your mobile phone on the train. This media revolution is changing the way organisations get their message out. And it is encouraging companies such as advertising agencies to be creative about new ways of accessing audiences. The good news is that we have fresh opportunities to reach young people through internet-based media and material downloaded through tools such as games machines, as well as through the traditional media. And it is important for Europlanet to make the most of these new and exciting developments.

  10. Has Athletic Performance Reached its Peak?

    Science.gov (United States)

    Berthelot, Geoffroy; Sedeaud, Adrien; Marck, Adrien; Antero-Jacquemin, Juliana; Schipman, Julien; Saulière, Guillaume; Marc, Andy; Desgorces, François-Denis; Toussaint, Jean-François

    2015-09-01

    Limits to athletic performance have long been a topic of myth and debate. However, sport performance appears to have reached a state of stagnation in recent years, suggesting that the physical capabilities of humans and other athletic species, such as greyhounds and thoroughbreds, cannot progress indefinitely. Although the ultimate capabilities may be predictable, the exact path for the absolute maximal performance values remains difficult to assess and relies on technical innovations, sport regulation, and other parameters that depend on current societal and economic conditions. The aim of this literature review was to assess the possible plateau of top physical capabilities in various events and detail the historical backgrounds and sociocultural, anthropometrical, and physiological factors influencing the progress and regression of athletic performance. Time series of performances in Olympic disciplines, such as track and field and swimming events, from 1896 to 2012 reveal a major decrease in performance development. Such a saturation effect is simultaneous in greyhound, thoroughbred, and frog performances. The genetic condition, exhaustion of phenotypic pools, economic context, and the depletion of optimal morphological traits contribute to the observed limitation of physical capabilities. Present conditions prevailing, we approach absolute physical limits and endure a continued period of world record scarcity. Optional scenarios for further improvements will mostly depend on sport technology and modification competition rules.

  11. LEP Dismantling Reaches Half-Way Stage

    CERN Multimedia

    2001-01-01

    LEP's last superconducting module leaves its home port... Just seven months into the operation, LEP dismantling is forging ahead. Two of the eight arcs which form the tunnel have already been emptied and the last of the accelerator's radiofrequency (RF) cavities has just been raised to the surface. The 160 people working on LEP dismantling have reason to feel pleased with their progress. All of the accelerator's 72 superconducting RF modules have already been brought to the surface, with the last one being extracted on 2nd May. This represents an important step in the dismantling process, as head of the project, John Poole, explains. 'This was the most delicate part of the project, because the modules are very big and they could only come out at one place', he says. The shaft at point 1.8 through which the RF cavity modules pass is 18 metres in diameter, while each module is 11.5 metres long. Some modules had to travel more than 10 kilometres to reach the shaft. ... is lifted up the PM 1.8 shaft, after a m...

  12. CAST reaches milestone but keeps on searching

    CERN Multimedia

    CERN Courier (september 2011 issue)

    2011-01-01

    After eight years of searching for the emission of a dark matter candidate particle, the axion, from the Sun, the CERN Axion Solar Telescope (CAST) has fulfilled its original physics programme.   Members of the CAST collaboration in July, together with dipole-based helioscope. CAST, the world’s most sensitive axion helioscope, points a recycled prototype LHC dipole magnet at the Sun at dawn and dusk, looking for the conversion of axions to X-rays. It incorporates four state-of-the-art X-ray detectors: three Micromegas detectors and a pn-CCD imaging camera attached to a focusing X-ray telescope that was recovered from the German space programme (see CERN Courier April 2010).  Over the years, CAST has operated with the magnet bores - the location of the axion conversion - in different conditions: first in vacuum, covering axion masses up to 20 meV/c2, and then with a buffer gas (4He and later 3He) at various densities, finally reaching the goal of 1.17 eV/c2 on 22 ...

  13. Important ATLAS Forward Calorimeter Milestone Reached

    CERN Document Server

    Loch, P.

    The ATLAS Forward Calorimeter working group has reached an important milestone in the production of their detectors. The mechanical assembly of the first electromagnetic module (FCal1C) has been completed at the University of Arizona on February 25, 2002, only ten days after the originally scheduled date. The photo shows the University of Arizona FCal group in the clean room, together with the assembled FCal1C module. The module consists of a stack of 18 round copper plates, each about one inch thick. Each plate is about 90 cm in diameter, and has 12260 precision-drilled holes in it, to accommodate the tube/rod electrode assembly. The machining of the plates, which was done at the Science Technology Center (STC) at Carleton University, Ottawa, Canada, required high precision to allow for easy insertion of the electrode copper tube. The plates have been carefully cleaned at the University of Arizona, to remove any machining residue and metal flakes. This process alone took about eleven weeks. Exactly 122...

  14. Discovery Reach for Black Hole Production

    CERN Document Server

    The ATLAS collaboration

    2009-01-01

    Models with extra space dimensions, in which our Universe exists on a 4-dimensional brane embedded in a higher dimensional bulk space-time, offer a new way to address outstanding problems in and beyond the Standard Model. In such models the Planck scale in the bulk can be of the order of the electroweak symmetry breaking scale. This allows the coupling strength of gravity to increase to a size similar to the other interactions, opening the way to the unification of gravity and the gauge interactions. The increased strength of gravity in the bulk space-time means that quantum gravity effects would be observable in the TeV energy range reachable by the LHC. The most spectacular phenomenon would be the production of black holes, which would decay semi-classically by Hawking radiation emitting high energy particles. In this note, we discuss the potential for the ATLAS experiment to discover such black holes in the early data (1--1000 pb$^{-1}$).

  15. Atomic-scale luminescence measurement and theoretical analysis unveiling electron energy dissipation at a p-type GaAs(110) surface

    International Nuclear Information System (INIS)

    Imada, Hiroshi; Miwa, Kuniyuki; Jung, Jaehoon; Shimizu, Tomoko K; Kim, Yousoo; Yamamoto, Naoki

    2015-01-01

    Luminescence of p-type GaAs was induced by electron injection from the tip of a scanning tunnelling microscope into a GaAs(110) surface. Atomically-resolved photon maps revealed a significant reduction in luminescence intensity at surface electronic states localized near Ga atoms. Theoretical analysis based on first principles calculations and a rate equation approach was performed to describe the perspective of electron energy dissipation at the surface. Our study reveals that non-radiative recombination through the surface states (SS) is a dominant process for the electron energy dissipation at the surface, which is suggestive of the fast scattering of injected electrons into the SS. (paper)

  16. Planning of the Extended Reach well Dieksand 2; Planung der Extended Reach Bohrung Dieksand 2

    Energy Technology Data Exchange (ETDEWEB)

    Frank, U.; Berners, H. [RWE-DEA AG, Hamburg (Germany). Drilling Team Mittelplate und Dieksand; Hadow, A.; Klop, G.; Sickinger, W. [Wintershall AG Erdoelwerke, Barnstdorf (Germany); Sudron, K.

    1998-12-31

    The Mittelplate oil field is located 7 km offshore the town of Friedrichskoog. Reserves are estimated at 30 million tonnes of oil. At a production rate of 2,500 t/d, it will last about 33 years. The transport capacity of the offshore platform is limited, so that attempts were made to enhance production by constructing the extended reach borehole Dieksand 2. Details are presented. (orig.) [Deutsch] Das Erdoelfeld Mittelplate liegt am suedlichen Rand des Nationalparks Schleswig Holsteinisches Wattenmeer, ca. 7000 m westlich der Ortschaft Friedrichskoog. Die gewinnbaren Reserven betragen ca. 30 Millionen t Oel. Bei einer Foerderkapazitaet von 2.500 t/Tag betraegt die Foerderdauer ca. 33 Jahre. Aufgrund der begrenzten Transportkapazitaeten von der Insel, laesst sich durch zusaetzliche Bohrungen von der kuenstlichen Insel Mittelplate keine entscheidende Erhoehung der Foerderkapazitaet erzielen. Ab Sommer 1996 wurde erstmals die Moeglichkeit der Lagerstaettenerschliessung von Land untersucht. Ein im Mai 1997 in Hamburg etabliertes Drilling Team wurde mit der Aufgabe betraut, die Extended Reach Bohrung Dieksand 2 zu planen und abzuteufen. Die Planungsphasen fuer die Extended Reach Bohrung Dieksand 2 wurden aufgezeigt. Die fuer den Erfolg einer Extended Reach Bohrung wichtigen Planungsparameter wurden erlaeutert. Es wurden Wege gezeigt, wie bei diesem Projekt technische und geologische Risiken in der Planung mit beruecksichtigt und nach Beginn der Bohrung weiter bearbeitet werden koennen. (orig.)

  17. When Does the Warmest Water Reach Greenland?

    Science.gov (United States)

    Grist, J. P.; Josey, S. A.; Boehme, L.; Meredith, M. P.; Laidre, K. L.; Heide-Jørgensen, M. P.; Kovacs, K. M.; Lydersen, C.; Davidson, F. J. M.; Stenson, G. B.; Hammill, M. O.; Marsh, R.; Coward, A.

    2016-02-01

    The warmest water reaching the east and west coast of Greenland is found between 200 and 600 m, in the warm Atlantic Water Layer (WL). Temperature changes within the WL have been highlighted as a possible cause of accelerated melting of tidewater glaciers and therefore are an important consideration for understanding global sea level rise. However, a limited number of winter observations of the WL have prohibited determining its seasonal variability. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database, and unprecedented coverage from marine-mammal borne sensors have been analyzed for the period 2002-2011. A significant seasonal range in temperature ( 1-2°C) is found in the warm layer, in contrast to most of the surrounding ocean. The magnitude of the seasonal cycle is thus comparable with the 1990s warming that was associated with an increased melt rate in a marine terminating glacier of West Greenland. The phase of the seasonal cycle exhibits considerable spatial variability; with high-resolution ocean model trajectory analysis suggesting it is determined by the time taken for waters to be advected from the subduction site in the Irminger Basin. For western Greenland, the annual temperature maximum occurs near or after the turn of the calendar year. This is significant because a recent study suggested that it is in the non-summer months when fjord-shelf exchanges allow the WL to most strongly influence glacier melt rate. However this is also the time of the year when the WL is least well observed. It is therefore clear that year-round subsurface temperature measurements are still required for a complete description of the WL seasonality, and in particular to ensure that the ice-melting potential of the WL is not underestimated.

  18. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal.

    Science.gov (United States)

    Style, Sarah; Beard, B James; Harris-Fry, Helen; Sengupta, Aman; Jha, Sonali; Shrestha, Bhim P; Rai, Anjana; Paudel, Vikas; Thondoo, Meelan; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Manandhar, Dharma S; Costello, Anthony; Saville, Naomi M

    2017-01-01

    The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Controlled Trial in the rural plains of Nepal, to help other researchers planning to use EDC for complex studies in low-income settings. We designed and implemented three interrelated mobile phone data collection systems to enrol and follow-up pregnant women (trial participants), and to support the implementation of trial interventions (women's groups, food and cash transfers). 720 field staff used basic phones to send simple coded text messages, 539 women's group facilitators used Android smartphones with Open Data Kit Collect, and 112 Interviewers, Coordinators and Supervisors used smartphones with CommCare. Barcoded photo ID cards encoded with participant information were generated for each enrolled woman. Automated systems were developed to download, recode and merge data for nearly real-time access by researchers. The systems were successfully rolled out and used by 1371 staff. A total of 25,089 pregnant women were enrolled, and 17,839 follow-up forms completed. Women's group facilitators recorded 5717 women's groups and the distribution of 14,647 food and 13,482 cash transfers. Using EDC sped up data collection and processing, although time needed for programming and set-up delayed the study inception. EDC using three interlinked mobile data management systems (FrontlineSMS, ODK and CommCare) was a feasible and effective method of data capture in a complex large-scale trial in the plains of Nepal. Despite challenges including prolonged set-up times, the systems met multiple data

  19. Reaching remote areas in Latin America.

    Science.gov (United States)

    Jaimes, R

    1994-01-01

    Poor communities in remote and inaccessible areas tend to not only be cut off from family planning education and services, but they are also deprived of basic primary health care services. Efforts to bring family planning to such communities and populations should therefore be linked with other services. The author presents three examples of programs to bring effective family planning services to remote communities in Central and South America. Outside of the municipal center in the Tuxtlas region of Mexico, education and health levels are low and people live according to ancient customs. Ten years ago with the help of MEXFAM, the IPPF affiliate in Mexico, two social promoters established themselves in the town of Catemaco to develop a community program of family planning and health care offering education and prevention to improve the quality of people's lives. Through their health brigades taking health services to towns without an established health center, the program has influenced an estimated 100,000 people in 50 villages and towns. The program also has a clinic. In Guatemala, the Family Welfare Association (APROFAM) gave bicycles to 240 volunteer health care workers to facilitate their outreach work in rural areas. APROFAM since 1988 has operated an integrated program to treat intestinal parasites and promote family planning in San Lucas de Toliman, an Indian town close to Lake Atitlan. Providing health care to more than 10,000 people, the volunteer staff has covered the entire department of Solola, reaching each family in the area. Field educators travel on motorcycles through the rural areas of Guatemala coordinating with the health volunteers the distribution of contraceptives at the community level. The Integrated Project's Clinic was founded in 1992 and currently carries out pregnancy and Pap tests, as well as general lab tests. Finally, Puna is an island in the middle of the Gulf of Guayaquil, Ecuador. Women on the island typically have 10

  20. Perspective: Reaches of chemical physics in biology

    Science.gov (United States)

    Gruebele, Martin; Thirumalai, D.

    2013-01-01

    Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry. PMID:24089712

  1. Perspective: Reaches of chemical physics in biology.

    Science.gov (United States)

    Gruebele, Martin; Thirumalai, D

    2013-09-28

    Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry.

  2. Functional reach and lateral reach tests adapted for aquatic physical therapy

    Directory of Open Access Journals (Sweden)

    Ana Angélica Ribeiro de Lima

    Full Text Available Abstract Introduction: Functional reach (FR and lateral reach (LR tests are widely used in scientific research and clinical practice. Assessment tools are useful in assessing subjects with greater accuracy and are usually adapted according to the limitations of each condition. Objective: To adapt FR and LR tests for use in an aquatic environment and assess the performance of healthy young adults. Methods: We collected anthropometric data and information on whether the participant exercised regularly or not. The FR and LR tests were adapted for use in an aquatic environment and administered to 47 healthy subjects aged 20-30 years. Each test was repeated three times. Results: Forty-one females and six males were assessed. The mean FR test score for men was 24.06 cm, whereas the mean value for right lateral reach (RLR was 10.94 cm and for left lateral reach (LLR was 9.78 cm. For females, the mean FR score was 17.57 cm, while the mean values for RLR was 8.84cm and for LLR was 7.76 cm. Men performed better in the FR (p < 0.001 and RLR tests than women (p = 0.037. Individuals who exercised regularly showed no differences in performance level when compared with their counterparts. Conclusion: The FR and LR tests were adapted for use in an aquatic environment. Males performed better on the FR and RLR tests, when compared to females. There was no correlation between the FR and LR tests and weight, height, Body Mass Index (BMI, foot length or length of the dominant upper limb.

  3. The Role of Absorption Cooling for Reaching Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, Susanne

    2005-07-01

    This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO{sub 2} emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO{sub 2} emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO{sub 2} emissions can be lowered to 45 CO{sub 2}/MWh{sub c} by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.

  4. Near-GeV-energy laser-wakefield acceleration of self-injected electrons in a centimeter-scale plasma channel

    International Nuclear Information System (INIS)

    Tsung, F.S.; Narang, Ritesh; Joshi, C.; Mori, W. B.; Fonseca, R. A.; Silva, L.O.

    2004-01-01

    The first three-dimensional, particle-in-cell (PIC) simulations of laser-wakefield acceleration of self-injected electrons in a 0.84 cm long plasma channel are reported. The frequency evolution of the initially 50 fs (FWHM) long laser pulse by photon interaction with the wake followed by plasma dispersion enhances the wake which eventually leads to self-injection of electrons from the channel wall. This first bunch of electrons remains spatially highly localized. Its phase space rotation due to slippage with respect to the wake leads to a monoenergetic bunch of electrons with a central energy of 0.26 GeV after 0.55 cm propagation. At later times, spatial bunching of the laser enhances the acceleration of a second bunch of electrons to energies up to 0.84 GeV before the laser pulse intensity is significantly reduced

  5. The Inner Structure of Collisionless Magnetic Reconnection: The Electron-Frame Dissipation Measure and Hall Fields

    Science.gov (United States)

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha

    2011-01-01

    It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron s rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.

  6. The inner structure of collisionless magnetic reconnection: The electron-frame dissipation measure and Hall fields

    International Nuclear Information System (INIS)

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha

    2011-01-01

    It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron's rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.

  7. The inner structure of collisionless magnetic reconnection: The electron-frame dissipation measure and Hall fields

    Energy Technology Data Exchange (ETDEWEB)

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Black, Carrie; Kuznetsova, Masha [NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

    2011-12-15

    It was recently proposed that the electron-frame dissipation measure, the energy transfer from the electromagnetic field to plasmas in the electron's rest frame, identifies the dissipation region of collisionless magnetic reconnection [Zenitani et al., Phys. Rev. Lett. 106, 195003 (2011)]. The measure is further applied to the electron-scale structures of antiparallel reconnection, by using two-dimensional particle-in-cell simulations. The size of the central dissipation region is controlled by the electron-ion mass ratio, suggesting that electron physics is essential. A narrow electron jet extends along the outflow direction until it reaches an electron shock. The jet region appears to be anti-dissipative. At the shock, electron heating is relevant to a magnetic cavity signature. The results are summarized to a unified picture of the single dissipation region in a Hall magnetic geometry.

  8. Action without awareness: reaching to an object you do not remember seeing.

    Directory of Open Access Journals (Sweden)

    Matthew Heath

    Full Text Available BACKGROUND: Previous work by our group has shown that the scaling of reach trajectories to target size is independent of obligatory awareness of that target property and that "action without awareness" can persist for up to 2000 ms of visual delay. In the present investigation we sought to determine if the ability to scale reaching trajectories to target size following a delay is related to the pre-computing of movement parameters during initial stimulus presentation or the maintenance of a sensory (i.e., visual representation for on-demand response parameterization. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed immediate or delayed (i.e., 2000 ms perceptual reports and reaching responses to different sized targets under non-masked and masked target conditions. For the reaching task, the limb associated with a trial (i.e., left or right was not specified until the time of response cuing: a manipulation that prevented participants from pre-computing the effector-related parameters of their response. In terms of the immediate and delayed perceptual tasks, target size was accurately reported during non-masked trials; however, for masked trials only a chance level of accuracy was observed. For the immediate and delayed reaching tasks, movement time as well as other temporal kinematic measures (e.g., times to peak acceleration, velocity and deceleration increased in relation to decreasing target size across non-masked and masked trials. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that speed-accuracy relations were observed regardless of whether participants were aware (i.e., non-masked trials or unaware (i.e., masked trials of target size. Moreover, the equivalent scaling of immediate and delayed reaches during masked trials indicates that a persistent sensory-based representation supports the unconscious and metrical scaling of memory-guided reaching.

  9. Chemical placement in heterogeneous and long reach horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Stalker, Robert; Wahid, Fazrie; Graham, Gordon M.

    2006-03-15

    The effective placement of chemical squeeze treatments in heterogeneous wells and long reach horizontal wells has proved a significant challenge, with various factors including heterogeneity, crossflow and pressure gradients between otherwise non-communicating zones within the well, all contributing to an uneven placement of the scale squeeze treatment into the reservoir. Current methods to circumvent these problems often rely on extremely expensive coiled tubing operations, staged diversion (temporary shut off) treatments or by designing treatments to deliberately overdose some zones in order to gain placement in other (e.g. low permeability) zones. Moreover for deepwater sub sea horizontal wells the costs associated with ''spot'' treating along the length of horizontal wells by coil tubing tractor operations can often be prohibitively expensive. For other very near well bore treatments such as acid stimulation a number of self diverting strategies including gelled acid treatments, staged viscoelastic surfactant treatments and foams have been applied in field treatments with some success. However the properties which make such treatments applicable for acid stimulation may also make them inappropriate for bullhead scale squeeze treatments. Recent work by the current authors has however indicated the possible benefits of using modified injection fluids to aid uniform scale inhibitor placement in such wells in order to effect more even placement. In summary this paper will describe the various options available for achieving self diversion and describes the potential drawbacks associated with the viscous placement fluids commonly used for acid simulation techniques. In addition, various simulation packages commonly used for scale related calculations are reviewed and their limitations, primarily due to the inherent assumptions made and input parameters used, for modelling squeeze treatments using such modified fluids are described. The paper

  10. LDRD final report for improving human effectiveness for extreme-scale problem solving : assessing the effectiveness of electronic brainstorming in an industrial setting.

    Energy Technology Data Exchange (ETDEWEB)

    Dornburg, Courtney C.; Stevens, Susan Marie; Davidson, George S.; Hendrickson, Stacey M. Langfitt

    2008-09-01

    An experiment was conducted comparing the effectiveness of individual versus group electronic brainstorming in order to address difficult, real world challenges. While industrial reliance on electronic communications has become ubiquitous, empirical and theoretical understanding of the bounds of its effectiveness have been limited. Previous research using short-term, laboratory experiments have engaged small groups of students in answering questions irrelevant to an industrial setting. The present experiment extends current findings beyond the laboratory to larger groups of real-world employees addressing organization-relevant challenges over the course of four days. Employees and contractors at a national security laboratory participated, either in a group setting or individually, in an electronic brainstorm to pose solutions to a 'wickedly' difficult problem. The data demonstrate that (for this design) individuals perform at least as well as groups in producing quantity of electronic ideas, regardless of brainstorming duration. However, when judged with respect to quality along three dimensions (originality, feasibility, and effectiveness), the individuals significantly (p<0.05) out-performed the group working together. When idea quality is used as the benchmark of success, these data indicate that work-relevant challenges are better solved by aggregating electronic individual responses, rather than electronically convening a group. This research suggests that industrial reliance upon electronic problem solving groups should be tempered, and large nominal groups might be the more appropriate vehicle for solving wicked corporate issues.

  11. WE-AB-204-12: Dosimetry at the Sub-Cellular Scale of Auger-Electron Emitter 99m-Tc in a Mouse Single Thyroid Follicle Model

    Energy Technology Data Exchange (ETDEWEB)

    Taborda, A; Benabdallah, N; Desbree, A [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-roses (France)

    2015-06-15

    Purpose: To perform a dosimetry study at the sub-cellular scale of Auger-electron emitter 99m-Tc using a mouse single thyroid cellular model to investigate the contribution of the 99m-Tc Auger-electrons to the absorbed dose and possible link to the thyroid stunning in in vivo experiments in mice, recently reported in literature. Methods: The simulation of S-values for Auger-electron emitting radionuclides was performed using both the recent MCNP6 software and the Geant4-DNA extension of the Geant4 toolkit. The dosimetric calculations were validated through comparison with results from literature, using a simple model of a single cell consisting of two concentric spheres of unit density water and for six Auger-electron emitting radionuclides. Furthermore, the S-values were calculated using a single thyroid follicle model for uniformly distributed 123-I and 125-I radionuclides and compared with published S-values. After validation, the simulation of the S-values was performed for the 99m-Tc radionuclide within the several mouse thyroid follicle cellular compartments, considering the radiative and non-radiative transitions of the 99m-Tc radiation spectrum. Results: The calculated S-values using MCNP6 are in good agreement with the results from literature, validating its use for the 99m-Tc S-values calculations. The most significant absorbed dose corresponds to the case where the radionuclide is uniformly distributed in the follicular cell’s nucleus, with a S-value of 7.8 mGy/disintegration, due mainly to the absorbed Auger-electrons. The results show that, at a sub-cellular scale, the emitted X-rays and gamma particles do not contribute significantly to the absorbed dose. Conclusion: In this work, MCNP6 was validated for dosimetric studies at the sub-cellular scale. It was shown that the contribution of the Auger-electrons to the absorbed dose is important at this scale compared to the emitted photons’ contribution and can’t be neglected. The obtained S

  12. Guaranteed performance in reaching mode of sliding mode ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    addresses the design of constant plus proportional rate reaching law-based SMC for second-order ... Reaching mode; sliding mode controlled systems; output tracking ... The uncertainty in the input distribution function g is expressed as.

  13. Nanomaterials under REACH. Nanosilver as a case study

    NARCIS (Netherlands)

    Pronk MEJ; Wijnhoven SWP; Bleeker EAJ; Heugens EHW; Peijnenburg WJGM; Luttik R; Hakkert BC; SEC; SIR; LER

    2009-01-01

    Om de risico's van nanomaterialen te kunnen inschatten en beheersen, zijn enkele aanpassingen nodig in de Europese chemicalienwetgeving REACH. De gegevens over stoffen waar REACH standaard om vraagt, zijn namelijk onvoldoende om de specifieke eigenschappen van nanomaterialen te bepalen. Hetzelfde

  14. Reaching Adolescents and Youth in Burkina Faso, Guinea-Bissau

    African Journals Online (AJOL)

    AJRH Managing Editor

    typical profile of individuals in contact with peer educators or attending youth ... being reached (versus not reached) by programs ... characteristics in order to serve groups that may be ... places for counseling services but the frequency of.

  15. Reaching Hard-to-Reach Individuals: Nonselective Versus Targeted Outbreak Response Vaccination for Measles

    Science.gov (United States)

    Minetti, Andrea; Hurtado, Northan; Grais, Rebecca F.; Ferrari, Matthew

    2014-01-01

    Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals. PMID:24131555

  16. Copper atomic-scale transistors.

    Science.gov (United States)

    Xie, Fangqing; Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen; Schimmel, Thomas

    2017-01-01

    We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO 4 + H 2 SO 4 ) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and -170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes ( U bias ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1 G 0 ( G 0 = 2e 2 /h; with e being the electron charge, and h being Planck's constant) or 2 G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

  17. A large-scale R-matrix calculation for electron-impact excitation of the Ne2 +, O-like ion

    OpenAIRE

    McLaughlin , B M; Lee , Teck-Ghee; Ludlow , J A; Landi , E; Loch , S D; Pindzola , M S; Ballance , C P

    2011-01-01

    Abstract The five J? levels within a np2 or np4 ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron temperature and density diagnostics. The low temperature nature of the line ratios ensure that the theoretically derived values are sensitive to the underlying atomic structure and electron-impact excitation rates. Previous R- matrix calculations for the O-like ...

  18. Towards Liquid Chromatography Time-Scale Peptide Sequencing and Characterization of Post-Translational Modifications in the Negative-Ion Mode Using Electron Detachment Dissociation Tandem Mass Spectrometry

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Hørning, Ole B; Jensen, Søren S

    2008-01-01

    Electron detachment dissociation (EDD) of peptide poly-anions is gentle towards post-translational modifications (PTMs) and produces predictable and interpretable fragment ion types (a., x ions). However, EDD is considered an inefficient fragmentation technique and has not yet been implemented...... coverage and extended PTM characterization the new regime of EDD in combination with other ion-electron fragmentation techniques in the positive-ion mode is a step towards a more comprehensive strategy of analysis in proteome research....

  19. THE DEVELOPMENT OF A SUPER-STABLE DATUM POINT FOR MONITORING THE ENERGY SCALE OF ELECTRON SPECTROMETERS IN THE ENERGY RANGE UP TO 20 keV

    Czech Academy of Sciences Publication Activity Database

    Vénos, Drahoslav; Zbořil, Miroslav; Kašpar, Jaromír; Dragoun, Otokar; Bonn, J.; Kovalík, Alojz; Lebeda, Ondřej; Lebedev, N. A.; Ryšavý, Miloš; Schlosser, K.; Špalek, Antonín; Weinheimer, C.

    2010-01-01

    Roč. 53, č. 3 (2010), s. 305-312 ISSN 0543-1972 R&D Projects: GA ČR GA202/06/0002; GA MŠk LA318; GA MŠk LC07050; GA MŠk LA08002 Institutional research plan: CEZ:AV0Z10480505 Keywords : nuclear transition energy * conversion electrons * electron spectrometer Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.154, year: 2010

  20. Morphological adjustments in a meandering reach of the middle Yangtze River caused by severe human activities

    Science.gov (United States)

    Zhou, Meirong; Xia, Junqiang; Lu, Jinyou; Deng, Shanshan; Lin, Fenfen

    2017-05-01

    In the past 50 years, the Shishou reach in the middle Yangtze River underwent significant channel evolution owing to the implementation of an artificial cutoff, the construction of bank revetment works and the operation of the Three Gorges Project (TGP). Based on the measured hydrological data and topographic data, the processes of channel evolution in this reach were investigated mainly from the adjustments in planform and cross-sectional geometries. The variation in planform geometry obtained in this study indicates that (i) the artificial cutoff at Zhongzhouzi caused the river regime to adjust drastically, with the mean rate of thalweg migration at reach scale of 42.0 m/a over the period 1966-1975; (ii) then the effect of this artificial cutoff reduced gradually, with the mean migration rate decreasing to 40 m/a owing to the occurrence of high water levels in 1993-1998; and (iii) the average annual rate of thalweg migration decreased to 29.3 m/a because of the impacts of various bank protection engineering and the TGP operation during the period 2002-2015. However, remarkable thalweg migration processes still occurred in local regions after the TGP operation, which resulted in significant bankline migration in local reaches of Beimenkou, Shijiatai, and Tiaoxiankou. In addition, the adjustments of bankfull channel geometry were investigated at section and reach scales after the TGP operation. Calculated results show that lateral channel migration in this reach was restricted by various river regulation works and that channel evolution was mainly characterized by an increase in bankfull depth and cross-sectional area. Empirical relationships were developed between the reach-scale bankfull dimensions (depth and area), the bankfull widths at specified sections, and the previous 5-year average fluvial erosion intensity during flood seasons, with high correlation degrees between them being obtained.

  1. Association between imagined and actual functional reach (FR): a comparison of young and older adults.

    Science.gov (United States)

    Gabbard, Carl; Cordova, Alberto

    2013-01-01

    Recent studies indicate that the ability to mentally represent action using motor imagery declines with advanced age (>64 years). As the ability to represent action declines, the elderly may experience increasing difficulty with movement planning and execution. Here, we determined the association between estimation of reach via use of motor imagery and actual FR. Young adults (M=22 years) and older adults (M=66 years) estimated reach while standing with targets randomly presented in peripersonal (within actual reach) and extrapersonal (beyond reach) space. Imagined responses were compared to the individual's scaled maximum reach. FR, also while standing, was assessed using the standardized Functional Reach Test (FRT). Results for total score estimation accuracy showed that there was no difference for age; however, results for mean bias and distribution of error revealed that the older group underestimated while the younger group overestimated. In reference to FR, younger adults outperformed older adults (30 versus 14in.) and most prominent, only the younger group showed a significant relationship between estimation and FR. In addition to gaining insight to the effects of advanced age on the ability to mentally represent action and its association with movement execution, these results although preliminary, may have clinical implications based on the question of whether motor imagery training could improve movement estimations and how that might affect actual reach. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Printed Electronics

    Science.gov (United States)

    Wade, Jessica; Hollis, Joseph Razzell; Wood, Sebastian

    2018-04-01

    The combination of printing technology with manufacturing electronic devices enables a new paradigm of printable electronics, where 'smart' functionality can be readily incorporated into almost any product at low cost. Over recent decades, rapid progress has been made in this field, which is now emerging into the industrial andcommercial realm. However, successful development and commercialisation on a large scale presents some significant technical challenges. For fully-printable electronic systems, all the component parts must be deposited from solutions (inks), requiring the development of new inorganic, organic and hybrid materials.A variety of traditional printing techniques are being explored and adapted forprinting these new materials in ways that result in the best performing electronicdevices. Whilst printed electronics research has initially focused on traditional typesof electronic device such as light-emitting diodes, transistors, and photovoltaics, it is increasingly apparent that a much wider range of applications can be realised. The soft and stretchable nature of printable materials makes them perfect candidates forbioelectronics, resulting in a wealth of research looking at biocompatible printable inks and biosensors. Regardless of application, the properties of printed electronicmaterials depend on the chemical structures, processing conditions, device architecture,and operational conditions, the complex inter-relationships of which aredriving ongoing research. We focus on three particular 'hot topics', where attention is currently focused: novel materials, characterisation techniques, and device stability. With progress advancing very rapidly, printed electronics is expected to grow over the next decade into a key technology with an enormous economic and social impact.

  3. Expanding the reach of heavy neutrino searches at the LHC

    Directory of Open Access Journals (Sweden)

    Andrés Flórez

    2018-03-01

    Full Text Available The observation of neutrino oscillations establishes that neutrinos have non-zero mass and provides one of the more compelling arguments for physics beyond the standard model (SM of particle physics. We present a feasibility study to search for hypothetical Majorana neutrinos (N with TeV scale masses, predicted by extensions of the SM to explain the small but non-zero SM neutrino mass, using vector boson fusion (VBF processes at the 13 TeV LHC. In the context of the minimal Type-I seesaw mechanism (mTISM, the VBF production cross-section of a lepton (ℓ and associated heavy Majorana neutrino (Nℓ surpasses that of the Drell–Yan process at approximately mNℓ=1.4TeV. We consider second and third-generation heavy neutrino (Nμ or Nτ, where ℓ= muon (μ or tau (τ leptons production through VBF processes, with subsequent Nμ and Nτ decays to a lepton and two jets, as benchmark cases to show the effectiveness of the VBF topology for Nℓ searches at the 13 TeV LHC. The requirement of a dilepton pair combined with four jets, two of which are identified as VBF jets with large separation in pseudorapidity and a TeV scale dijet mass, is effective at reducing the SM background. These criteria may provide expected exclusion bounds, at 95% confidence level, of mNℓ<1.7 (2.4 TeV, assuming 100 (1000 fb−1 of 13 TeV data from the LHC and mixing |VℓNℓ|2=1. The use of the VBF topology to search for mNℓ increases the discovery reach at the LHC, with expected significances greater than 5σ (3σ for Nℓ masses up to 1.7 (2.05 TeV using 1000fb−1 of 13 TeV data from the LHC.

  4. Expanding the reach of heavy neutrino searches at the LHC

    Science.gov (United States)

    Flórez, Andrés; Gui, Kaiwen; Gurrola, Alfredo; Patiño, Carlos; Restrepo, Diego

    2018-03-01

    The observation of neutrino oscillations establishes that neutrinos have non-zero mass and provides one of the more compelling arguments for physics beyond the standard model (SM) of particle physics. We present a feasibility study to search for hypothetical Majorana neutrinos (N) with TeV scale masses, predicted by extensions of the SM to explain the small but non-zero SM neutrino mass, using vector boson fusion (VBF) processes at the 13 TeV LHC. In the context of the minimal Type-I seesaw mechanism (mTISM), the VBF production cross-section of a lepton (ℓ) and associated heavy Majorana neutrino (Nℓ) surpasses that of the Drell-Yan process at approximately mNℓ = 1.4TeV. We consider second and third-generation heavy neutrino (Nμ or Nτ, where ℓ= muon (μ) or tau (τ) leptons) production through VBF processes, with subsequent Nμ and Nτ decays to a lepton and two jets, as benchmark cases to show the effectiveness of the VBF topology for Nℓ searches at the 13 TeV LHC. The requirement of a dilepton pair combined with four jets, two of which are identified as VBF jets with large separation in pseudorapidity and a TeV scale dijet mass, is effective at reducing the SM background. These criteria may provide expected exclusion bounds, at 95% confidence level, of mNℓ < 1.7 (2.4) TeV, assuming 100 (1000) fb-1 of 13 TeV data from the LHC and mixing |VℓNℓ|2 = 1. The use of the VBF topology to search for mNℓ increases the discovery reach at the LHC, with expected significances greater than 5σ (3σ) for Nℓ masses up to 1.7 (2.05) TeV using 1000fb-1 of 13 TeV data from the LHC.

  5. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  6. Action plans can interact to hinder or facilitate reach performance.

    Science.gov (United States)

    Fournier, Lisa R; Wiediger, Matthew D; Taddese, Ezana F

    2015-11-01

    Executing a reach action can be delayed while retaining another action in working memory (WM) if the two action plans partly overlap rather than do not overlap. This delay (partial repetition cost) occurs when reach responses are under cognitive control. In this study, we investigated whether facilitation (a partial repetition benefit) occurs when reach responses are automatic. We also examined whether the hemisphere controlling the limb or selection of the preferred limb (based on a free-reach task) influences reach performance when the actions partly overlap. Left- and right-handers reached to different stimulus locations to the left and right of body midline with their ipsilateral hand while maintaining an action plan in WM that required the same or the different hand. The results showed a partial repetition benefit for spatially compatible reaches to left and right stimulus locations far from the body midline, but not for those near the body midline. Also, no partial repetition cost was found at any of the stimulus-reach locations. This indicates that automatic reach responses that partly overlap with an action plan maintained in WM are not delayed, but instead can be facilitated (partial repetition benefit). The roles of hemisphere and reach-hand preference in action control and the importance of the degree of feature overlap in obtaining a partial repetition benefit (and cost) are discussed.

  7. Runaway electrons and magnetic island confinement

    International Nuclear Information System (INIS)

    Boozer, Allen H.

    2016-01-01

    The breakup of magnetic surfaces is a central feature of ITER planning for the avoidance of damage due to runaway electrons. Rapid thermal quenches, which lead to large accelerating voltages, are thought to be due to magnetic surface breakup. Impurity injection to avoid and to mitigate both halo and runaway electron currents utilizes massive gas injection or shattered pellets. The actual deposition is away from the plasma center, and the breakup of magnetic surfaces is thought to spread the effects of the impurities across the plasma cross section. The breakup of magnetic surfaces would prevent runaway electrons from reaching relativistic energies were it not for the persistence of non-intercepting flux tubes. These are tubes of magnetic field lines that do not intercept the walls. In simulations and in magnetic field models, non-intercepting flux tubes are found to persist near the magnetic axis and in the cores of magnetic islands even when a large scale magnetic surface breakup occurs. As long as a few magnetic surfaces reform before all of the non-intercepting flux tubes dissipate, energetic electrons confined and accelerated in these flux tubes can serve as the seed electrons for a transfer of the overall plasma current from thermal to relativistic carriers. The acceleration of electrons is particularly strong because of the sudden changes in the poloidal flux that naturally occur in a rapid magnetic relaxation. The physics of magnetic islands as non-intercepting flux tubes is studied. Expressions are derived for (1) the size of islands required to confine energetic runaway electrons, (2) the accelerating electric field in an island, (3) the increase or reduction in the size of an island by the runaway electron current, (4) the approximate magnitude of the runaway current in an island, and (5) the time scale for the evolution of an island.

  8. Runaway electrons and magnetic island confinement

    Energy Technology Data Exchange (ETDEWEB)

    Boozer, Allen H., E-mail: ahb17@columbia.edu [Columbia University, New York, New York 10027 (United States)

    2016-08-15

    The breakup of magnetic surfaces is a central feature of ITER planning for the avoidance of damage due to runaway electrons. Rapid thermal quenches, which lead to large accelerating voltages, are thought to be due to magnetic surface breakup. Impurity injection to avoid and to mitigate both halo and runaway electron currents utilizes massive gas injection or shattered pellets. The actual deposition is away from the plasma center, and the breakup of magnetic surfaces is thought to spread the effects of the impurities across the plasma cross section. The breakup of magnetic surfaces would prevent runaway electrons from reaching relativistic energies were it not for the persistence of non-intercepting flux tubes. These are tubes of magnetic field lines that do not intercept the walls. In simulations and in magnetic field models, non-intercepting flux tubes are found to persist near the magnetic axis and in the cores of magnetic islands even when a large scale magnetic surface breakup occurs. As long as a few magnetic surfaces reform before all of the non-intercepting flux tubes dissipate, energetic electrons confined and accelerated in these flux tubes can serve as the seed electrons for a transfer of the overall plasma current from thermal to relativistic carriers. The acceleration of electrons is particularly strong because of the sudden changes in the poloidal flux that naturally occur in a rapid magnetic relaxation. The physics of magnetic islands as non-intercepting flux tubes is studied. Expressions are derived for (1) the size of islands required to confine energetic runaway electrons, (2) the accelerating electric field in an island, (3) the increase or reduction in the size of an island by the runaway electron current, (4) the approximate magnitude of the runaway current in an island, and (5) the time scale for the evolution of an island.

  9. Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

    2014-11-15

    In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ∼300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub β}). The detectors impulse response function was measured in situ on NIF short-pulse (∼90 ps) experiments, and in off-line tests.

  10. Multi-scale full-orbit analysis on phase-space behavior of runaway electrons in tokamak fields with synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yulei; Liu, Jian, E-mail: jliuphy@ustc.edu.cn [School of Nuclear Science and Technology and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Key Laboratory of Geospace Environment, CAS, Hefei, Anhui 230026 (China); Qin, Hong [School of Nuclear Science and Technology and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2016-06-15

    In this paper, the secular full-orbit simulations of runaway electrons with synchrotron radiation in tokamak fields are carried out using a relativistic volume-preserving algorithm. Detailed phase-space behaviors of runaway electrons are investigated in different dynamical timescales spanning 11 orders. In the small timescale, i.e., the characteristic timescale imposed by Lorentz force, the severely deformed helical trajectory of energetic runaway electron is witnessed. A qualitative analysis of the neoclassical scattering, a kind of collisionless pitch-angle scattering phenomena, is provided when considering the coupling between the rotation of momentum vector and the background magnetic field. In large timescale up to 1 s, it is found that the initial condition of runaway electrons in phase space globally influences the pitch-angle scattering, the momentum evolution, and the loss-gain ratio of runaway energy evidently. However, the initial value has little impact on the synchrotron energy limit. It is also discovered that the parameters of tokamak device, such as the toroidal magnetic field, the loop voltage, the safety factor profile, and the major radius, can modify the synchrotron energy limit and the strength of neoclassical scattering. The maximum runaway energy is also proved to be lower than the synchrotron limit when the magnetic field ripple is considered.

  11. Proton-Coupled Electron Transfer and a Tyrosine-Histidine Pair in a Photosystem II-Inspired β-Hairpin Maquette: Kinetics on the Picosecond Time Scale.

    Science.gov (United States)

    Pagba, Cynthia V; McCaslin, Tyler G; Chi, San-Hui; Perry, Joseph W; Barry, Bridgette A

    2016-02-25

    Photosystem II (PSII) and ribonucleotide reductase employ oxidation and reduction of the tyrosine aromatic ring in radical transport pathways. Tyrosine-based reactions involve either proton-coupled electron transfer (PCET) or electron transfer (ET) alone, depending on the pH and the pKa of tyrosine's phenolic oxygen. In PSII, a subset of the PCET reactions are mediated by a tyrosine-histidine redox-driven proton relay, YD-His189. Peptide A is a PSII-inspired β-hairpin, which contains a single tyrosine (Y5) and histidine (H14). Previous electrochemical characterization indicated that Peptide A conducts a net PCET reaction between Y5 and H14, which have a cross-strand π-π interaction. The kinetic impact of H14 has not yet been explored. Here, we address this question through time-resolved absorption spectroscopy and 280-nm photolysis, which generates a neutral tyrosyl radical. The formation and decay of the neutral tyrosyl radical at 410 nm were monitored in Peptide A and its variant, Peptide C, in which H14 is replaced by cyclohexylalanine (Cha14). Significantly, both electron transfer (ET, pL 11, L = lyonium) and PCET (pL 9) were accelerated in Peptide A and C, compared to model tyrosinate or tyrosine at the same pL. Increased electronic coupling, mediated by the peptide backbone, can account for this rate acceleration. Deuterium exchange gave no significant solvent isotope effect in the peptides. At pL 9, but not at pL 11, the reaction rate decreased when H14 was mutated to Cha14. This decrease in rate is attributed to an increase in reorganization energy in the Cha14 mutant. The Y5-H14 mechanism in Peptide A is reminiscent of proton- and electron-transfer events involving YD-H189 in PSII. These results document a mechanism by which proton donors and acceptors can regulate the rate of PCET reactions.

  12. Electron attachment cross sections obtained from electron attachment spectroscopy

    International Nuclear Information System (INIS)

    Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.

    1988-01-01

    Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)

  13. Molecular electron affinities

    International Nuclear Information System (INIS)

    Fukuda, E.K.

    1983-01-01

    Molecular electron affinities have historically been difficult quantities to measure accurately. These difficulties arise from differences in structure between the ion and neutral as well as the existence of excited negative ion states. To circumvent these problems, relative electron affinities were determined in this dissertation by studying equilibrium electron transfer reactions using a pulsed ion cyclotron resonance (ICR) spectrometer. Direct measurement of ion and neutral concentrations for reactions of the general type, A - + B = B - + A, allow calculation of the equilibrium constant and, therefore, the free energy change. The free energy difference is related to the difference in electron affinities between A and B. A relative electron affinity scale covering a range of about 45 kcal/mol was constructed with various substituted p-benzoquinones, nitrobenzenes, anhydrides, and benzophenones. To assign absolute electron affinities, various species with accurately known electron affinities are tied to the scale via ion-cyclotron double resonance bracketing techniques. After the relative scale is anchored to these species with well-known electron affinities, the scale is then used as a check on other electron affinity values as well as generating new electron affinity values. Many discrepancies were found between the electron affinities measured using the ICR technique and previous literature determinations

  14. Reach/frequency for printed media: Personal probabilities or models

    DEFF Research Database (Denmark)

    Mortensen, Peter Stendahl

    2000-01-01

    The author evaluates two different ways of estimating reach and frequency of plans for printed media. The first assigns reading probabilities to groups of respondents and calculates reach and frequency by simulation. the second estimates parameters to a model for reach/frequency. It is concluded ...... and estiamtes from such models are shown to be closer to panel data. the problem, however, is to get valid input for such models from readership surveys. Means for this are discussed....

  15. Evaluating Regime Change of Sediment Transport in the Jingjiang River Reach, Yangtze River, China

    Directory of Open Access Journals (Sweden)

    Li He

    2018-03-01

    Full Text Available The sediment regime in the Jingjiang river reach of the middle Yangtze River has been significantly changed from quasi-equilibrium to unsaturated since the impoundment of the Three Gorges Dam (TGD. Vertical profiles of suspended sediment concentration (SSC and sediment flux can be adopted to evaluate the sediment regime at the local and reach scale, respectively. However, the connection between the vertical concentration profiles and the hydrologic conditions of the sub-saturated channel has rarely been examined based on field data. Thus, vertical concentration data at three hydrological stations in the reach (Zhicheng, Shashi, and Jianli are collected. Analyses show that the near-bed concentration (within 10% of water depth from the riverbed may reach up to 15 times that of the vertical average concentration. By comparing the fractions of the suspended sediment and bed material before and after TGD operation, the geomorphic condition under which the distinct large near-bed concentrations occur have been examined. Based on daily discharge-sediment hydrographs, the reach scale sediment regime and availability of sediment sources are analyzed. In total, remarkable large near-bed concentrations may respond to the combination of wide grading suspended particles and bed material. Finally, several future challenges caused by the anomalous vertical concentration profiles in the unsaturated reach are discussed. This indicates that more detailed measurements or new measuring technologies may help us to provide accurate measurements, while a fractional dispersion equation may help us in describing. The present study aims to gain new insights into regime change of sediment suspension in the river reaches downstream of a very large reservoir.

  16. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal

    OpenAIRE

    Style, S.; Beard, B. J.; Harris-Fry, H.; Sengupta, A.; Jha, S.; Shrestha, B. P.; Rai, A.; Paudel, V.; Thondoo, M.; Pulkki-Brannstrom, A-M; Skordis-Worrall, J.; Manandhar, D. S.; Costello, A.; Saville, N. M.

    2017-01-01

    The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Controlled Tria...

  17. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal

    OpenAIRE

    Style, Sarah; Beard, B. James; Harris-Fry, Helen; Sengupta, Aman; Jha, Sonali; Shrestha, Bhim P.; Rai, Anjana; Paudel, Vikas; Thondoo, Meelan; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Manandhar, Dharma S.; Costello, Anthony; Saville, Naomi M.

    2017-01-01

    ABSTRACT The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Contro...

  18. Gaze anchoring guides real but not pantomime reach-to-grasp: support for the action-perception theory.

    Science.gov (United States)

    Kuntz, Jessica R; Karl, Jenni M; Doan, Jon B; Whishaw, Ian Q

    2018-04-01

    Reach-to-grasp movements feature the integration of a reach directed by the extrinsic (location) features of a target and a grasp directed by the intrinsic (size, shape) features of a target. The action-perception theory suggests that integration and scaling of a reach-to-grasp movement, including its trajectory and the concurrent digit shaping, are features that depend upon online action pathways of the dorsal visuomotor stream. Scaling is much less accurate for a pantomime reach-to-grasp movement, a pretend reach with the target object absent. Thus, the action-perception theory proposes that pantomime movement is mediated by perceptual pathways of the ventral visuomotor stream. A distinguishing visual feature of a real reach-to-grasp movement is gaze anchoring, in which a participant visually fixates the target throughout the reach and disengages, often by blinking or looking away/averting the head, at about the time that the target is grasped. The present study examined whether gaze anchoring is associated with pantomime reaching. The eye and hand movements of participants were recorded as they reached for a ball of one of three sizes, located on a pedestal at arms' length, or pantomimed the same reach with the ball and pedestal absent. The kinematic measures for real reach-to-grasp movements were coupled to the location and size of the target, whereas the kinematic measures for pantomime reach-to-grasp, although grossly reflecting target features, were significantly altered. Gaze anchoring was also tightly coupled to the target for real reach-to-grasp movements, but there was no systematic focus for gaze, either in relation with the virtual target, the previous location of the target, or the participant's reaching hand, for pantomime reach-to-grasp. The presence of gaze anchoring during real vs. its absence in pantomime reach-to-grasp supports the action-perception theory that real, but not pantomime, reaches are online visuomotor actions and is discussed in

  19. RiverCare communication strategy for reaching beyond

    Science.gov (United States)

    Cortes Arevalo, Juliette; den Haan, Robert Jan; Berends, Koen; Leung, Nick; Augustijn, Denie; Hulscher, Suzanne J. M. H.

    2017-04-01

    Effectively communicating river research to water professionals and researchers working in multiple disciplines or organizations is challenging. RiverCare studies the mid-term effects of innovative river interventions in the Netherlands to improve river governance and sustainable management. A total of 21 researchers working at 5 universities are part of the consortium, which also includes research institutes, consultancies, and water management authorities. RiverCare results do not only benefit Dutch river management, but can also provide useful insights to challenges abroad. Dutch partner organizations actively involved in RiverCare are our direct users. However, we want to reach water professionals from the Netherlands and beyond. To communicate with and disseminate to these users, we set up a communication strategy that includes the following approaches : (1) Netherlands Centre of River studies (NCR) website to announce activities post news, not limited to RiverCare; (2) A RiverCare newsletter that is published twice per year to update about our progress and activities; (3) A multimedia promotional providing a 'first glance' of RiverCare. It consists of four video episodes and an interactive menu; (4) An interactive knowledge platform to provide access, explain RiverCare results and gather feedback about the added value and potential use of these results; and (5) A serious gaming environment titled Virtual River where actors can play out flood scaling intervention and monitoring strategies to assess maintenance scenarios. The communication strategy and related approaches are being designed and developed during the project. We use participatory methods and systematic evaluation to understand communication needs and to identify needs for improvement. As a first step, RiverCare information is provided via the NCR website. The active collaboration with the NCR is important to extend communication efforts beyond the RiverCare consortium and after the program ends

  20. Single-step electron transfer on the nanometer scale: ultra-fast charge shift in strongly coupled zinc porphyrin-gold porphyrin dyads.

    Science.gov (United States)

    Fortage, Jérôme; Boixel, Julien; Blart, Errol; Hammarström, Leif; Becker, Hans Christian; Odobel, Fabrice

    2008-01-01

    The synthesis, electrochemical properties, and photoinduced electron transfer processes of a series of three novel zinc(II)-gold(III) bisporphyrin dyads (ZnP--S--AuP(+)) are described. The systems studied consist of two trisaryl porphyrins connected directly in the meso position via an alkyne unit to tert-(phenylenethynylene) or penta(phenylenethynylene) spacers. In these dyads, the estimated center to center interporphyrin separation distance varies from 32 to 45 A. The absorption, emission, and electrochemical data indicate that there are strong electronic interactions between the linked elements, thanks to the direct attachment of the spacer on the porphyrin ring through the alkyne unit. At room temperature in toluene, light excitation of the zinc porphyrin results in almost quantitative formation of the charge shifted state (.+)ZnP--S--AuP(.), whose lifetime is in the order of hundreds of picoseconds. In this solvent, the charge-separated state decays to the ground state through the intermediate population of the zinc porphyrin triplet excited state. Excitation of the gold porphyrin leads instead to rapid energy transfer to the triplet ZnP. In dichloromethane the charge shift reactions are even faster, with time constants down to 2 ps, and may be induced also by excitation of the gold porphyrin. In this latter solvent, the longest charge-shifted lifetime (tau=2.3 ns) was obtained with the penta-(phenylenethynylene) spacer. The charge shift reactions are discussed in terms of bridge-mediated super-exchange mechanisms as electron or hole transfer. These new bis-porphyrin arrays, with strong electronic coupling, represent interesting molecular systems in which extremely fast and efficient long-range photoinduced charge shift occurs over a long distance. The rate constants are two to three orders of magnitude larger than for corresponding ZnP--AuP(+) dyads linked via meso-phenyl groups to oligo-phenyleneethynylene spacers. This study demonstrates the critical

  1. Impulsivity modulates performance under response uncertainty in a reaching task.

    Science.gov (United States)

    Tzagarakis, C; Pellizzer, G; Rogers, R D

    2013-03-01

    We sought to explore the interaction of the impulsivity trait with response uncertainty. To this end, we used a reaching task (Pellizzer and Hedges in Exp Brain Res 150:276-289, 2003) where a motor response direction was cued at different levels of uncertainty (1 cue, i.e., no uncertainty, 2 cues or 3 cues). Data from 95 healthy adults (54 F, 41 M) were analysed. Impulsivity was measured using the Barratt Impulsiveness Scale version 11 (BIS-11). Behavioral variables recorded were reaction time (RT), errors of commission (referred to as 'early errors') and errors of precision. Data analysis employed generalised linear mixed models and generalised additive mixed models. For the early errors, there was an interaction of impulsivity with uncertainty and gender, with increased errors for high impulsivity in the one-cue condition for women and the three-cue condition for men. There was no effect of impulsivity on precision errors or RT. However, the analysis of the effect of RT and impulsivity on precision errors showed a different pattern for high versus low impulsives in the high uncertainty (3 cue) condition. In addition, there was a significant early error speed-accuracy trade-off for women, primarily in low uncertainty and a 'reverse' speed-accuracy trade-off for men in high uncertainty. These results extend those of past studies of impulsivity which help define it as a behavioural trait that modulates speed versus accuracy response styles depending on environmental constraints and highlight once more the importance of gender in the interplay of personality and behaviour.

  2. Setting the scene for SWOT: global maps of river reach hydrodynamic variables

    Science.gov (United States)

    Schumann, Guy J.-P.; Durand, Michael; Pavelsky, Tamlin; Lion, Christine; Allen, George

    2017-04-01

    Credible and reliable characterization of discharge from the Surface Water and Ocean Topography (SWOT) mission using the Manning-based algorithms needs a prior estimate constraining reach-scale channel roughness, base flow and river bathymetry. For some places, any one of those variables may exist locally or even regionally as a measurement, which is often only at a station, or sometimes as a basin-wide model estimate. However, to date none of those exist at the scale required for SWOT and thus need to be mapped at a continental scale. The prior estimates will be employed for producing initial discharge estimates, which will be used as starting-guesses for the various Manning-based algorithms, to be refined using the SWOT measurements themselves. A multitude of reach-scale variables were derived, including Landsat-based width, SRTM slope and accumulation area. As a possible starting point for building the prior database of low flow, river bathymetry and channel roughness estimates, we employed a variety of sources, including data from all GRDC records, simulations from the long-time runs of the global water balance model (WBM), and reach-based calculations from hydraulic geometry relationships as well as Manning's equation. Here, we present the first global maps of this prior database with some initial validation, caveats and prospective uses.

  3. Modulation of hand aperture during reaching in persons with incomplete cervical spinal cord injury.

    Science.gov (United States)

    Stahl, Victoria A; Hayes, Heather B; Buetefisch, Cathrin M; Wolf, Steven L; Trumbower, Randy D

    2015-03-01

    The intact neuromotor system prepares for object grasp by first opening the hand to an aperture that is scaled according to object size and then closing the hand around the object. After cervical spinal cord injury (SCI), hand function is significantly impaired, but the degree to which object-specific hand aperture scaling is affected remains unknown. Here, we hypothesized that persons with incomplete cervical SCI have a reduced maximum hand opening capacity but exhibit novel neuromuscular coordination strategies that permit object-specific hand aperture scaling during reaching. To test this hypothesis, we measured hand kinematics and surface electromyography from seven muscles of the hand and wrist during attempts at maximum hand opening as well as reaching for four balls of different diameters. Our results showed that persons with SCI exhibited significantly reduced maximum hand aperture compared to able-bodied (AB) controls. However, persons with SCI preserved the ability to scale peak hand aperture with ball size during reaching. Persons with SCI also used distinct muscle coordination patterns that included increased co-activity of flexors and extensors at the wrist and hand compared to AB controls. These results suggest that motor planning for aperture modulation is preserved even though execution is limited by constraints on hand opening capacity and altered muscle co-activity. Thus, persons with incomplete cervical SCI may benefit from rehabilitation aimed at increasing hand opening capacity and reducing flexor-extensor co-activity at the wrist and hand.

  4. Successfully Changing the Landscape of Information Distribution: Extension Food Website Reaches People Locally and Globally

    OpenAIRE

    Alice Henneman; Lisa Franzen-Castle; Kayla Colgrove; Vishal Singh

    2016-01-01

    The goal of the Food website was to develop Internet-based content that was relevant and reached the general public and multiplier groups, such as educators, health professionals, and media outlets. The purpose of this paper was to examine whether a multi-modal approach to information delivery through increases in and changes to content, electronic mailing list creation, and social media posting impacted user access, traffic channels, and referrals from 2010 to 2014. When comparing 2010-2011 ...

  5. Should these potential CMR substances have been registered under REACH?

    DEFF Research Database (Denmark)

    Wedebye, Eva Bay; Nikolov, Nikolai Georgiev; Dybdahl, Marianne

    2013-01-01

    (Q)SAR models were applied to screen around 68,000 REACH pre-registered substances for CMR properties (carcinogenic, mutagenic or toxic to reproduction). Predictions from 14 relevant models were combined to reach overall calls for C, M and R. Combining predictions may reduce “noise” and increase...

  6. UP-scaling of inverted small molecule based organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Madsen, Morten

    Organic solar cells (OSC), in spite of being a promising technology, still face challenges regarding large-scale fabrication. Although efficiencies of up to 12 % has been reached for small molecule OSC, their performance, both in terms of device efficiency and stability, is significantly reduced...... during up-scaling processes. The work presented here is focused on an approach towards up-scaling of small molecule based OSC with inverted device configuration. Bilayer OSC from Tetraphenyldibenzoperiflanthene (DBP) and Fullerenes (C70), as electron donor and acceptor respectively, with cell area...

  7. Expanding the Reach of Education Reforms. What Have We Learned About Scaling Up Educational Interventions?

    National Research Council Canada - National Science Library

    2004-01-01

    Over the past 20 years, we have seen both increasing demand to improve the quality of education in the United States and a new supply of improvement practices generated by external set-vice providers...

  8. Charcterization of meadow ecosystems based on watershed and valley segment/reach scale characteristics [chapter 7

    Science.gov (United States)

    Wendy Trowbridge; Jeanne C. Chambers; Dru Germanoski; Mark L. Lord; Jerry R. Miller; David G. Jewett

    2011-01-01

    Great Basin riparian meadows are highly sensitive to both natural and anthropogenic disturbance. As detailed in earlier chapters, streams in the central Great Basin have a natural tendency to incise due to their geomorphic history (Miller and others 2001, 2004). Anthropogenic disturbances, including overgrazing by livestock, mining activities, and roads in the valley...

  9. Towards atomic scale engineering of rare-earth-doped SiAlON ceramics through aberration-corrected scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Yurdakul, Hilmi; Idrobo, Juan C.; Pennycook, Stephen J.; Turan, Servet

    2011-01-01

    Direct visualization of rare earths in α- and β-SiAlON unit-cells is performed through Z-contrast imaging technique in an aberration-corrected scanning transmission electron microscope. The preferential occupation of Yb and Ce atoms in different interstitial locations of β-SiAlON lattice is demonstrated, yielding higher solubility for Yb than Ce. The triangular-like host sites in α-SiAlON unit cell accommodate more Ce atoms than hexagonal sites in β-SiAlON. We think that our results will be applicable as guidelines for many kinds of rare-earth-doped materials.

  10. A comparison of texture results obtained using precession electron diffraction and neutron diffraction methods at diminishing length scales in ordered bimetallic nanolamellar composites

    International Nuclear Information System (INIS)

    Carpenter, J.S.; Liu, X.; Darbal, A.; Nuhfer, N.T.; McCabe, R.J.; Vogel, S.C.; LeDonne, J.E.; Rollett, A.D.; Barmak, K.; Beyerlein, I.J.; Mara, N.A.

    2012-01-01

    Precession electron diffraction (PED) is used to acquire orientation information in Cu–Nb nanolamellar composites fabricated by accumulative roll bonding (ARB). The resulting maps quantify the grain size, shape, orientation distributions and interface planes in the vicinity of nanometer-thick deformation twins. The PED-based texture results compare favorably with bulk textures provided by neutron diffraction measurements, indicating uniformity in the ARB Cu–Nb texture. Additionally, {1 1 2} Cu ||{1 1 2} Nb interfaces are present, suggesting that ARB techniques can lead to stable interfaces with a special crystallography.

  11. Switching from reaching to navigation: differential cognitive strategies for spatial memory in children and adults.

    Science.gov (United States)

    Belmonti, Vittorio; Cioni, Giovanni; Berthoz, Alain

    2015-07-01

    Navigational and reaching spaces are known to involve different cognitive strategies and brain networks, whose development in humans is still debated. In fact, high-level spatial processing, including allocentric location encoding, is already available to very young children, but navigational strategies are not mature until late childhood. The Magic Carpet (MC) is a new electronic device translating the traditional Corsi Block-tapping Test (CBT) to navigational space. In this study, the MC and the CBT were used to assess spatial memory for navigation and for reaching, respectively. Our hypothesis was that school-age children would not treat MC stimuli as navigational paths, assimilating them to reaching sequences. Ninety-one healthy children aged 6 to 11 years and 18 adults were enrolled. Overall short-term memory performance (span) on both tests, effects of sequence geometry, and error patterns according to a new classification were studied. Span increased with age on both tests, but relatively more in navigational than in reaching space, particularly in males. Sequence geometry specifically influenced navigation, not reaching. The number of body rotations along the path affected MC performance in children more than in adults, and in women more than in men. Error patterns indicated that navigational sequences were increasingly retained as global paths across development, in contrast to separately stored reaching locations. A sequence of spatial locations can be coded as a navigational path only if a cognitive switch from a reaching mode to a navigation mode occurs. This implies the integration of egocentric and allocentric reference frames, of visual and idiothetic cues, and access to long-term memory. This switch is not yet fulfilled at school age due to immature executive functions. © 2014 John Wiley & Sons Ltd.

  12. Heterogeneous hyporheic zone dechlorination of a TCE groundwater plume discharging to an urban river reach.

    Science.gov (United States)

    Freitas, Juliana G; Rivett, Michael O; Roche, Rachel S; Durrant Neé Cleverly, Megan; Walker, Caroline; Tellam, John H

    2015-02-01

    The typically elevated natural attenuation capacity of riverbed-hyporheic zones is expected to decrease chlorinated hydrocarbon (CHC) groundwater plume discharges to river receptors through dechlorination reactions. The aim of this study was to assess physico-chemical processes controlling field-scale variation in riverbed-hyporheic zone dechlorination of a TCE groundwater plume discharge to an urban river reach. The 50-m long pool-riffle-glide reach of the River Tame in Birmingham (UK) studied is a heterogeneous high energy river environment. The shallow riverbed was instrumented with a detailed network of multilevel samplers. Freeze coring revealed a geologically heterogeneous and poorly sorted riverbed. A chlorine number reduction approach provided a quantitative indicator of CHC dechlorination. Three sub-reaches of contrasting behaviour were identified. Greatest dechlorination occurred in the riffle sub-reach that was characterised by hyporheic zone flows, moderate sulphate concentrations and pH, anaerobic conditions, low iron, but elevated manganese concentrations with evidence of sulphate reduction. Transient hyporheic zone flows allowing input to varying riverbed depths of organic matter are anticipated to be a key control. The glide sub-reach displayed negligible dechlorination attributed to the predominant groundwater baseflow discharge condition, absence of hyporheic zone, transition to more oxic conditions and elevated sulphate concentrations expected to locally inhibit dechlorination. The tail-of-pool-riffle sub-reach exhibited patchy dechlorination that was attributed to sub-reach complexities including significant flow bypass of a low permeability, high organic matter, silty unit of high dechlorination potential. A process-based conceptual model of reach-scale dechlorination variability was developed. Key findings of practitioner relevance were: riverbed-hyporheic zone CHC dechlorination may provide only a partial, somewhat patchy barrier to CHC

  13. An investigation of the neural circuits underlying reaching and reach-to-grasp movements: from planning to execution.

    Directory of Open Access Journals (Sweden)

    Chiara eBegliomini

    2014-09-01

    Full Text Available Experimental evidence suggests the existence of a sophisticated brain circuit specifically dedicated to reach-to-grasp planning and execution, both in human and non human primates (Castiello, 2005. Studies accomplished by means of neuroimaging techniques suggest the hypothesis of a dichotomy between a reach-to-grasp circuit, involving the intraparietal area (AIP, the dorsal and ventral premotor cortices (PMd and PMv - Castiello and Begliomini, 2008; Filimon, 2010 and a reaching circuit involving the medial intraparietal area (mIP and the Superior Parieto-Occipital Cortex (SPOC (Culham et al., 2006. However, the time course characterizing the involvement of these regions during the planning and execution of these two types of movements has yet to be delineated. A functional magnetic resonance imaging (fMRI study has been conducted, including reach-to grasp and reaching only movements, performed towards either a small or a large stimulus, and Finite Impulse Response model (FIR - Henson, 2003 was adopted to monitor activation patterns from stimulus onset for a time window of 10 seconds duration. Data analysis focused on brain regions belonging either to the reaching or to the grasping network, as suggested by Castiello & Begliomini (2008.Results suggest that reaching and grasping movements planning and execution might share a common brain network, providing further confirmation to the idea that the neural underpinnings of reaching and grasping may overlap in both spatial and temporal terms (Verhagen et al., 2013.

  14. Proprioceptive body illusions modulate the visual perception of reaching distance.

    Directory of Open Access Journals (Sweden)

    Agustin Petroni

    Full Text Available The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide-without engaging in explicit action-whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas.

  15. Proximal and distal adjustments of reaching behavior in preterm infants.

    Science.gov (United States)

    de Toledo, Aline Martins; Soares, Daniele de Almeida; Tudella, Eloisa

    2011-01-01

    The authors aimed to investigate proximal and distal adjustments of reaching behavior and grasping in 5-, 6-, and 7-month-old preterm infants. Nine low-risk preterm and 10 full-term infants participated. Both groups showed the predominance of unimanual reaching, an age-related increase in the frequency of vertical-oriented and open hand movement, and also an increase in successful grasping from 6 to 7 months. The frequency of open hand was higher in the preterm group at 6 months. Intrinsic restrictions imposed by prematurity did not seem to have impaired reaching performance of preterm infants throughout the months of age.

  16. Hybrid MPI-OpenMP Parallelism in the ONETEP Linear-Scaling Electronic Structure Code: Application to the Delamination of Cellulose Nanofibrils.

    Science.gov (United States)

    Wilkinson, Karl A; Hine, Nicholas D M; Skylaris, Chris-Kriton

    2014-11-11

    We present a hybrid MPI-OpenMP implementation of Linear-Scaling Density Functional Theory within the ONETEP code. We illustrate its performance on a range of high performance computing (HPC) platforms comprising shared-memory nodes with fast interconnect. Our work has focused on applying OpenMP parallelism to the routines which dominate the computational load, attempting where possible to parallelize different loops from those already parallelized within MPI. This includes 3D FFT box operations, sparse matrix algebra operations, calculation of integrals, and Ewald summation. While the underlying numerical methods are unchanged, these developments represent significant changes to the algorithms used within ONETEP to distribute the workload across CPU cores. The new hybrid code exhibits much-improved strong scaling relative to the MPI-only code and permits calculations with a much higher ratio of cores to atoms. These developments result in a significantly shorter time to solution than was possible using MPI alone and facilitate the application of the ONETEP code to systems larger than previously feasible. We illustrate this with benchmark calculations from an amyloid fibril trimer containing 41,907 atoms. We use the code to study the mechanism of delamination of cellulose nanofibrils when undergoing sonification, a process which is controlled by a large number of interactions that collectively determine the structural properties of the fibrils. Many energy evaluations were needed for these simulations, and as these systems comprise up to 21,276 atoms this would not have been feasible without the developments described here.

  17. Long-range interfacial electron transfer and electrocatalysis of molecular scale Prussian Blue nanoparticles linked to Au(111)-electrode surfaces by different chemical contacting groups

    DEFF Research Database (Denmark)

    Zhu, Nan; Ulstrup, Jens; Chi, Qijin

    2017-01-01

    We have explored interfacial electrochemical electron transfer (ET) and electrocatalysis of 5–6 nm Prussian Blue nanoparticles (PBNPs) immobilized on Au(111)-electrode surfaces via molecular wiring with variable-length, and differently functionalized thiol-based self-assembled molecular monolayers...... (SAMs). The SAMs contain positively (−NH3+) or negatively charged (–COO–) terminal group, as well an electrostatically neutral hydrophobic terminal group (–CH3). The surface microscopic structures of the immobilized PBNPs were characterized by high-resolution atomic force microscopy (AFM) directly...... in aqueous electrolyte solution under the same conditions as for electrochemical measurements. The PBNPs displayed fast and reversible interfacial ET on all the surfaces, notably in multi-ET steps as reflected in narrow voltammetric peaks. The ET kinetics can be controlled by adjusting the length of the SAM...

  18. Peer Support for the Hardly Reached: A Systematic Review.

    Science.gov (United States)

    Sokol, Rebeccah; Fisher, Edwin

    2016-07-01

    Health disparities are aggravated when prevention and care initiatives fail to reach those they are intended to help. Groups can be classified as hardly reached according to a variety of circumstances that fall into 3 domains: individual (e.g., psychological factors), demographic (e.g., socioeconomic status), and cultural-environmental (e.g., social network). Several reports have indicated that peer support is an effective means of reaching hardly reached individuals. However, no review has explored peer support effectiveness in relation to the circumstances associated with being hardly reached or across diverse health problems. To conduct a systematic review assessing the reach and effectiveness of peer support among hardly reached individuals, as well as peer support strategies used. Three systematic searches conducted in PubMed identified studies that evaluated peer support programs among hardly reached individuals. In aggregate, the searches covered articles published from 2000 to 2015. Eligible interventions provided ongoing support for complex health behaviors, including prioritization of hardly reached populations, assistance in applying behavior change plans, and social-emotional support directed toward disease management or quality of life. Studies were excluded if they addressed temporally isolated behaviors, were limited to protocol group classes, included peer support as the dependent variable, did not include statistical tests of significance, or incorporated comparison conditions that provided appreciable social support. We abstracted data regarding the primary health topic, categorizations of hardly reached groups, program reach, outcomes, and strategies employed. We conducted a 2-sample t test to determine whether reported strategies were related to reach. Forty-seven studies met our inclusion criteria, and these studies represented each of the 3 domains of circumstances assessed (individual, demographic, and cultural-environmental). Interventions

  19. Bioremediation of PAHs contaminated river sediment by an integrated approach with sequential injection of co-substrate and electron acceptor: Lab-scale study

    International Nuclear Information System (INIS)

    Liu, Tongzhou; Zhang, Zhen; Dong, Wenyi; Wu, Xiaojing; Wang, Hongjie

    2017-01-01

    In this study, the feasibility of employing an integrated bioremediation approach in contaminated river sediment was evaluated. Sequential addition of co-substrate (acetate) and electron acceptor (NO 3 − ) in a two-phase treatment was capable of effectively removing polycyclic aromatic hydrocarbons (PAHs) in river sediment. The residual concentration of total PAHs decreased to far below effect range low (ERL) value within 91 days of incubation, at which concentration it could rarely pose biological impairment. The biodegradation of high molecular weight PAHs were found to be mainly occurred in the sediment treated with co-substrates (i.e. acetate or methanol), in which acetate was found to be more suitable for PAHs degradation. The role of co-substrates in influencing PAHs biodegradation was tentatively discussed herein. Additionally, the sediment odorous problem and blackish appearance were intensively addressed by NO 3 − injection. The results of this study demonstrated that integrating two or more approaches/processes would be a helpful option in sediment remediation. It can lead to a more effective remediation performance, handle multiple contamination issues, as well as mitigate environmental risks caused by one of the single methods. - Highlights: • Sequential addition of acetate and NO 3 − removed PAHs and mitigated sediment odor. • Acetate is a suitable co-substrate used for PAHs degradation in river sediment. • NO 3 − Injection was effective for sediment odor and blackish appearance mitigation. • Integrated method is suggested in complicated real case with multi-remedial target. - Sequential addition of co-substrate and electron acceptor was capable of effectively removing PAHs and addressing sediment odorous problem and blackish appearance.

  20. The Cognition of Maximal Reach Distance in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Satoru Otsuki

    2016-01-01

    Full Text Available This study aimed to investigate whether the cognition of spatial distance in reaching movements was decreased in patients with Parkinson’s disease (PD and whether this cognition was associated with various symptoms of PD. Estimated and actual maximal reaching distances were measured in three directions in PD patients and healthy elderly volunteers. Differences between estimated and actual measurements were compared within each group. In the PD patients, the associations between “error in cognition” of reaching distance and “clinical findings” were also examined. The results showed that no differences were observed in any values regardless of dominance of hand and severity of symptoms. The differences between the estimated and actual measurements were negatively deviated in the PD patients, indicating that they tended to underestimate reaching distance. “Error in cognition” of reaching distance correlated with the items of posture in the motor section of the Unified Parkinson’s Disease Rating Scale. This suggests that, in PD patients, postural deviation and postural instability might affect the cognition of the distance from a target object.

  1. Reach of the Fermilab Tevatron and CERN LHC for gaugino mediated SUSY breaking models

    International Nuclear Information System (INIS)

    Baer, Howard; Belyaev, Alexander; Krupovnickas, Tadas; Tata, Xerxes

    2002-01-01

    In supersymmetric models with gaugino mediated SUSY breaking (gMSB), it is assumed that SUSY breaking on a hidden brane is communicated to the visible brane via gauge superfields which propagate in the bulk. This leads to GUT models where the common gaugino mass m 1/2 is the only soft SUSY breaking term to receive contributions at the tree level. To obtain a viable phenomenology, it is assumed that the gaugino mass is induced at some scale M c beyond the GUT scale, and that additional renormalization group running takes place between M c and M GUT as in a SUSY GUT. We assume an SU(5) SUSY GUT above the GUT scale, and compute the SUSY particle spectrum expected in models with gMSB. We use the Monte Carlo program ISAJET to simulate signals within the gMSB model, and compute the SUSY reach including cuts and triggers appropriate to Fermilab Tevatron and CERN LHC experiments. We find no reach for SUSY by the Tevatron collider in the trilepton channel. At the CERN LHC, values of m 1/2 =1000 (1160) GeV can be probed with 10 (100) fb -1 of integrated luminosity, corresponding to a reach in terms of m g-tilde of 2150 (2500) GeV. The gMSB model and MSUGRA can likely only be differentiated at a linear e + e - collider with sufficient energy to produce sleptons and charginos

  2. PNW River Reach Files -- 1:100k Watercourses (arcs)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This feature class includes the ARC features from the 2001 version of the PNW River Reach files Arc/INFO coverage. Separate, companion feature classes are also...

  3. PNW River Reach Files -- 1:100k Waterbodies (polygons)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This feature class includes the POLYGON waterbody features from the 2001 version of the PNW River Reach files Arc/INFO coverage. Separate, companion feature classes...

  4. Stream Habitat Reach Summary - North Coast [ds63

    Data.gov (United States)

    California Natural Resource Agency — The shapefile is based on habitat unit level data summarized at the stream reach level. The database represents salmonid stream habitat surveys from 645 streams of...

  5. LTRM Fish Sampling Strata, UMRS La Grange Reach

    Data.gov (United States)

    Department of the Interior — The data set includes delineation of sampling strata for the six study reaches of the UMRR Program’s LTRM element. Separate strata coverages exist for each of the...

  6. LTRM Water Quality Sampling Strata, UMRS La Grange Reach

    Data.gov (United States)

    Department of the Interior — The data set includes delineation of sampling strata for the six study reaches of the UMRR Program’s LTRM element. Separate strata coverages exist for each of the...

  7. Local unitary transformation method for large-scale two-component relativistic calculations: case for a one-electron Dirac Hamiltonian.

    Science.gov (United States)

    Seino, Junji; Nakai, Hiromi

    2012-06-28

    An accurate and efficient scheme for two-component relativistic calculations at the spin-free infinite-order Douglas-Kroll-Hess (IODKH) level is presented. The present scheme, termed local unitary transformation (LUT), is based on the locality of the relativistic effect. Numerical assessments of the LUT scheme were performed in diatomic molecules such as HX and X(2) (X = F, Cl, Br, I, and At) and hydrogen halide clusters, (HX)(n) (X = F, Cl, Br, and I). Total energies obtained by the LUT method agree well with conventional IODKH results. The computational costs of the LUT method are drastically lower than those of conventional methods since in the former there is linear-scaling with respect to the system size and a small prefactor.

  8. Decoding natural reach-and-grasp actions from human EEG

    Science.gov (United States)

    Schwarz, Andreas; Ofner, Patrick; Pereira, Joana; Ioana Sburlea, Andreea; Müller-Putz, Gernot R.

    2018-02-01

    Objective. Despite the high number of degrees of freedom of the human hand, most actions of daily life can be executed incorporating only palmar, pincer and lateral grasp. In this study we attempt to discriminate these three different executed reach-and-grasp actions utilizing their EEG neural correlates. Approach. In a cue-guided experiment, 15 healthy individuals were asked to perform these actions using daily life objects. We recorded 72 trials for each reach-and-grasp condition and from a no-movement condition. Main results. Using low-frequency time domain features from 0.3 to 3 Hz, we achieved binary classification accuracies of 72.4%, STD  ±  5.8% between grasp types, for grasps versus no-movement condition peak performances of 93.5%, STD  ±  4.6% could be reached. In an offline multiclass classification scenario which incorporated not only all reach-and-grasp actions but also the no-movement condition, the highest performance could be reached using a window of 1000 ms for feature extraction. Classification performance peaked at 65.9%, STD  ±  8.1%. Underlying neural correlates of the reach-and-grasp actions, investigated over the primary motor cortex, showed significant differences starting from approximately 800 ms to 1200 ms after the movement onset which is also the same time frame where classification performance reached its maximum. Significance. We could show that it is possible to discriminate three executed reach-and-grasp actions prominent in people’s everyday use from non-invasive EEG. Underlying neural correlates showed significant differences between all tested conditions. These findings will eventually contribute to our attempt of controlling a neuroprosthesis in a natural and intuitive way, which could ultimately benefit motor impaired end users in their daily life actions.

  9. Interplay between electron-phonon and electron-electron interactions

    International Nuclear Information System (INIS)

    Roesch, O.; Gunnarsson, O.; Han, J.E.; Crespi, V.H.

    2005-01-01

    We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Detectors - Electronics

    International Nuclear Information System (INIS)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J.

    1998-01-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X → e - converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the 3 He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  11. Empirical scaling for present ohmic heated tokamaks

    International Nuclear Information System (INIS)

    Daughney, C.

    1975-06-01

    Empirical scaling laws are given for the average electron temperature and electron energy confinement time as functions of plasma current, average electron density, effective ion charge, toroidal magnetic field, and major and minor plasma radius. The ohmic heating is classical, and the electron energy transport is anomalous. The present scaling indicates that ohmic-heating becomes ineffective with larger experiments. (U.S.)

  12. REACH: next step to a sound chemicals management.

    Science.gov (United States)

    Van der Wielen, Arnold

    2007-12-01

    REACH is the new European Regulation for Registration, Evaluation, Authorisation and Restriction of Chemicals. It entered into force on 1st June 2007 to streamline and improve the former legislative framework on new and on existing chemical substances of the European Union. Companies which manufacture or import more than 1 tonne of a substance per year will be required to register the substance at the new EU Chemicals Agency located in Helsinki. REACH places greater responsibility on industry to manage the risks that chemicals may pose to the health and the environment and to provide safety information that will be passed down the supply chain. In principle, REACH applies to all chemicals as such, as components in preparations and as used in articles. REACH is a radical step forward in the EU chemicals management. The onus will move from the authorities to industry. In addition, REACH will allow the further evaluation of substances where there are grounds for concern, foresees an authorisation system for the use of substances of very high concern and a system of restrictions, where applicable, for substances of concern. The Authorisation system will require companies to switch progressively to safer alternatives where a suitable alternative exists. Current use restrictions will remain under REACH system.

  13. Development of a Low-power, Low-cost, Front-end Electronics Module for Large-Scale Distributed Neutrino Detectors. Final Report

    International Nuclear Information System (INIS)

    Saltzberg, David

    2009-01-01

    Final technical report for Advanced detector research program award at UCLA. To date, only two objects have been observed using neutrino messengers. However, each observation illustrates the incisive power of neutrino observations for both astrophysics and for particle physics. The first source observed with neutrinos was the Sun by Ray Davis and collaborators using a chlorine nuclear target. Until then, only electromagnetic emissions produced near the surface of the Sun had been studied. With neutrinos, the hydrogen-burning core of the Sun is directly observed - we now know even with its predicted intensity. Because neutrinos are so deeply penetrating, they give a direct window on the most energetic processes in the universe, unobscured by photospheres, fireballs and materials opaque to light. The solar neutrino observations largest impact however was felt by particle physicists. This experiment and follow-up experiments with water, heavy water, and gallium all observed the well-known deficit of the predicted number of electron-type neutrinos. After several decades of research using both astrophysical and accelerator observations inspired by this result, the effect is now known to be due the transformation of electron-type neutrinos into one of the two other flavors of neutrinos. These observations were the first and strongest data that showed particle physicists that the mass (propagating) eigenstates and weak eigenstates of neutrinos and their weak eigenstates are not identical. In addition, this transformation was the first indication that neutrinos have a small, but non-zero mass. The second, and latest, discovery of a cosmic neutrinos source was the explosion of supernova SN1987a in the Large Magellanic Cloud. In a type IIa supernova, 99% of the energy is expected to be released in the form of neutrinos since no other energy could escape the dense environment. The observations of SN1987a confirmed the theoretical models of this type of stellar core collapse

  14. Scale of corrections to the t-pole approximation in the quasielastic knockout of pions from nucleon by high energy electrons

    CERN Document Server

    Neudachin, V G; Yudin, N P

    2002-01-01

    Investigation of the dominant role of the simplest t-pole diagrams is completed in the processes of pion electroproduction on nucleons at quasielastic knock out kinematics and electron energies of a few GeV. Competition role of pi- and rho-meson t-pole diagrams and s-pole diagram (tree diagram) is regarded. When virtual photon mass is large enough (Q sup 2 >= 2 (GeV/c) sup 2), the latter amplitude is not essential both for longitudinal (d sigma sub L /dt) and for transverse (d sigma sub T /dt) cross sections. At Q sup 2 = 0.7 (GeV/c) sup 2 in the longitudinal cross section the interference term between pion t-pole and s-pole amplitudes is still essential. Vertex functions g subrho sub N sub N (t), obtained from the cross sections of the quasielastic knockout of rho mesons and from cross section of pion photoproduction, are compared. Their discrepancy must give impulse to the development of gauge invariant theory of pion photoproduction

  15. Comparing deep neural network and other machine learning algorithms for stroke prediction in a large-scale population-based electronic medical claims database.

    Science.gov (United States)

    Chen-Ying Hung; Wei-Chen Chen; Po-Tsun Lai; Ching-Heng Lin; Chi-Chun Lee

    2017-07-01

    Electronic medical claims (EMCs) can be used to accurately predict the occurrence of a variety of diseases, which can contribute to precise medical interventions. While there is a growing interest in the application of machine learning (ML) techniques to address clinical problems, the use of deep-learning in healthcare have just gained attention recently. Deep learning, such as deep neural network (DNN), has achieved impressive results in the areas of speech recognition, computer vision, and natural language processing in recent years. However, deep learning is often difficult to comprehend due to the complexities in its framework. Furthermore, this method has not yet been demonstrated to achieve a better performance comparing to other conventional ML algorithms in disease prediction tasks using EMCs. In this study, we utilize a large population-based EMC database of around 800,000 patients to compare DNN with three other ML approaches for predicting 5-year stroke occurrence. The result shows that DNN and gradient boosting decision tree (GBDT) can result in similarly high prediction accuracies that are better compared to logistic regression (LR) and support vector machine (SVM) approaches. Meanwhile, DNN achieves optimal results by using lesser amounts of patient data when comparing to GBDT method.

  16. Bioremediation of PAHs contaminated river sediment by an integrated approach with sequential injection of co-substrate and electron acceptor: Lab-scale study.

    Science.gov (United States)

    Liu, Tongzhou; Zhang, Zhen; Dong, Wenyi; Wu, Xiaojing; Wang, Hongjie

    2017-11-01

    In this study, the feasibility of employing an integrated bioremediation approach in contaminated river sediment was evaluated. Sequential addition of co-substrate (acetate) and electron acceptor (NO 3 - ) in a two-phase treatment was capable of effectively removing polycyclic aromatic hydrocarbons (PAHs) in river sediment. The residual concentration of total PAHs decreased to far below effect range low (ERL) value within 91 days of incubation, at which concentration it could rarely pose biological impairment. The biodegradation of high molecular weight PAHs were found to be mainly occurred in the sediment treated with co-substrates (i.e. acetate or methanol), in which acetate was found to be more suitable for PAHs degradation. The role of co-substrates in influencing PAHs biodegradation was tentatively discussed herein. Additionally, the sediment odorous problem and blackish appearance were intensively addressed by NO 3 - injection. The results of this study demonstrated that integrating two or more approaches/processes would be a helpful option in sediment remediation. It can lead to a more effective remediation performance, handle multiple contamination issues, as well as mitigate environmental risks caused by one of the single methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Near infrared spectroscopy to estimate the temperature reached on burned soils: strategies to develop robust models.

    Science.gov (United States)

    Guerrero, César; Pedrosa, Elisabete T.; Pérez-Bejarano, Andrea; Keizer, Jan Jacob

    2014-05-01

    The temperature reached on soils is an important parameter needed to describe the wildfire effects. However, the methods for measure the temperature reached on burned soils have been poorly developed. Recently, the use of the near-infrared (NIR) spectroscopy has been pointed as a valuable tool for this purpose. The NIR spectrum of a soil sample contains information of the organic matter (quantity and quality), clay (quantity and quality), minerals (such as carbonates and iron oxides) and water contents. Some of these components are modified by the heat, and each temperature causes a group of changes, leaving a typical fingerprint on the NIR spectrum. This technique needs the use of a model (or calibration) where the changes in the NIR spectra are related with the temperature reached. For the development of the model, several aliquots are heated at known temperatures, and used as standards in the calibration set. This model offers the possibility to make estimations of the temperature reached on a burned sample from its NIR spectrum. However, the estimation of the temperature reached using NIR spectroscopy is due to changes in several components, and cannot be attributed to changes in a unique soil component. Thus, we can estimate the temperature reached by the interaction between temperature and the thermo-sensible soil components. In addition, we cannot expect the uniform distribution of these components, even at small scale. Consequently, the proportion of these soil components can vary spatially across the site. This variation will be present in the samples used to construct the model and also in the samples affected by the wildfire. Therefore, the strategies followed to develop robust models should be focused to manage this expected variation. In this work we compared the prediction accuracy of models constructed with different approaches. These approaches were designed to provide insights about how to distribute the efforts needed for the development of robust

  18. Paleoclassical electron heat transport

    International Nuclear Information System (INIS)

    Callen, J.D.

    2005-01-01

    Radial electron heat transport in low collisionality, magnetically-confined toroidal plasmas is shown to result from paleoclassical Coulomb collision processes (parallel electron heat conduction and magnetic field diffusion). In such plasmas the electron temperature equilibrates along magnetic field lines a long length L, which is the minimum of the electron collision length and a maximum effective half length of helical field lines. Thus, the diffusing field lines induce a radial electron heat diffusivity M ≅ L/(πR 0q ) ∼ 10 >> 1 times the magnetic field diffusivity η/μ 0 ≅ ν e (c/ω p ) 2 . The paleoclassical electron heat flux model provides interpretations for many features of 'anomalous' electron heat transport: magnitude and radial profile of electron heat diffusivity (in tokamaks, STs, and RFPs), Alcator scaling in high density plasmas, transport barriers around low order rational surfaces and near a separatrix, and a natural heat pinch (or minimum temperature gradient) heat flux form. (author)

  19. Design of front end electronics and a full scale 4k pixel readout ASIC for the DSSC X-ray detector at the European XFEL

    International Nuclear Information System (INIS)

    Erdinger, Florian

    2016-01-01

    The goal of this thesis was to design a large scale readout ASIC for the 1-Mega pixel DEPFET Sensor with Signal Compression (DSSC) detector system which is being developed by an international collaboration for the European XFEL (EuXFEL). Requirements for the DSSC detector include single photon detection down to 0.5 keV combined with a large dynamic range of up to 10000 photons at frame rates of up to 4.5 MHz. The detector core concepts include full parallel readout, signal compression on the sensor or ASIC level, filtering, immediate digitization and local storage within the pixel. The DSSC is a hybrid pixel detector, each sensor pixel mates to a dedicated ASIC pixel, which includes the entire specified signal processing chain along with auxiliary circuits. One ASIC comprises 4096 pixels and a full periphery including biasing and digital control. This thesis presents the design of the ASIC, its components and integration are described in detail. Emphasis is put on the design of the analog front-end. The first full format ASIC (F1) has been fabricated within the scope of this thesis along with numerous test chips. Furthermore, the EuXFEL and the DSSC detector system are presented to create the context for the ASIC, which is the core topic of this thesis.

  20. Design of front end electronics and a full scale 4k pixel readout ASIC for the DSSC X-ray detector at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Erdinger, Florian

    2016-11-22

    The goal of this thesis was to design a large scale readout ASIC for the 1-Mega pixel DEPFET Sensor with Signal Compression (DSSC) detector system which is being developed by an international collaboration for the European XFEL (EuXFEL). Requirements for the DSSC detector include single photon detection down to 0.5 keV combined with a large dynamic range of up to 10000 photons at frame rates of up to 4.5 MHz. The detector core concepts include full parallel readout, signal compression on the sensor or ASIC level, filtering, immediate digitization and local storage within the pixel. The DSSC is a hybrid pixel detector, each sensor pixel mates to a dedicated ASIC pixel, which includes the entire specified signal processing chain along with auxiliary circuits. One ASIC comprises 4096 pixels and a full periphery including biasing and digital control. This thesis presents the design of the ASIC, its components and integration are described in detail. Emphasis is put on the design of the analog front-end. The first full format ASIC (F1) has been fabricated within the scope of this thesis along with numerous test chips. Furthermore, the EuXFEL and the DSSC detector system are presented to create the context for the ASIC, which is the core topic of this thesis.

  1. Memory-guided reaching in a patient with visual hemiagnosia.

    Science.gov (United States)

    Cornelsen, Sonja; Rennig, Johannes; Himmelbach, Marc

    2016-06-01

    The two-visual-systems hypothesis (TVSH) postulates that memory-guided movements rely on intact functions of the ventral stream. Its particular importance for memory-guided actions was initially inferred from behavioral dissociations in the well-known patient DF. Despite of rather accurate reaching and grasping movements to visible targets, she demonstrated grossly impaired memory-guided grasping as much as impaired memory-guided reaching. These dissociations were later complemented by apparently reversed dissociations in patients with dorsal damage and optic ataxia. However, grasping studies in DF and optic ataxia patients differed with respect to the retinotopic position of target objects, questioning the interpretation of the respective findings as a double dissociation. In contrast, the findings for reaching errors in both types of patients came from similar peripheral target presentations. However, new data on brain structural changes and visuomotor deficits in DF also questioned the validity of a double dissociation in reaching. A severe visuospatial short-term memory deficit in DF further questioned the specificity of her memory-guided reaching deficit. Therefore, we compared movement accuracy in visually-guided and memory-guided reaching in a new patient who suffered a confined unilateral damage to the ventral visual system due to stroke. Our results indeed support previous descriptions of memory-guided movements' inaccuracies in DF. Furthermore, our data suggest that recently discovered optic-ataxia like misreaching in DF is most likely caused by her parieto-occipital and not by her ventral stream damage. Finally, multiple visuospatial memory measurements in HWS suggest that inaccuracies in memory-guided reaching tasks in patients with ventral damage cannot be explained by visuospatial short-term memory or perceptual deficits, but by a specific deficit in visuomotor processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Electron microscopy of surfaces

    International Nuclear Information System (INIS)

    Venables, J.A.

    1981-01-01

    Electron beam techniques used to study clean surfaces and surface processes on a microscopic scale are reviewed. Recent experimental examples and possible future developments are discussed. Special emphasis is given to (i) transmission diffraction and microscopy techniques, including atomic imaging; (ii) Auger microscopy on bulk and thin film samples; (iii) secondary electron microscopy, especially low energy secondaries for work-function imaging and photoelectron imaging; and (iv) reflection electron microscopy and diffraction. (orig.)

  3. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  4. Digital radiography with a large-scale electronic flat-panel detector vs screen-film radiography: observer preference in clinical skeletal diagnostics

    International Nuclear Information System (INIS)

    Hamers, S.; Freyschmidt, J.; Neitzel, U.

    2001-01-01

    The imaging performance of a recently developed digital flat-panel detector system was compared with conventional screen-film imaging in an observer preference study. In total, 34 image pairs of various regions of the skeleton were obtained in 24 patients; 30 image pairs were included in the study. The conventional images were acquired with 250- and 400-speed screen-film combinations, using the standard technique of our department. Within hours, the digital images were obtained using identical exposure parameters. The digital system employed a large-area (43 x 43 cm) flat-panel detector based on amorphous silicon (Trixell Pixium 4600), integrated in a Bucky table. Six radiologists independently evaluated the image pairs with respect to image latitude, soft tissue rendition, rendition of the periosteal and enosteal border of cortical bone, rendition of cancellous bone and the visibility of potentially present pathological changes, using a subjective five-point scale. The digital images were rated significantly (p=0.001) better than the screen-film images with respect to soft tissue rendition and image latitude. Also the rendition of the cancellous bone and the periosteal and enosteal border of the cortical bone was rated significantly (p=0.05) better for the flat-panel detector. The visibility of pathological lesions was equivalent; only large-area sclerotic lesions (n=2) were seen superiorly on screen-film images. The new digital flat-panel detector based on amorphous silicon appears to be at least equivalent to conventional screen-film combinations for skeletal examinations, and in most respects even superior. (orig.)

  5. [The REACH legislation: the consumer and environment protection perspective].

    Science.gov (United States)

    Gundert-Remy, Ursula

    2008-12-01

    REACH has been initiated with the aim of improving existing legislation. In order to assist in the interpretation of the REACH legislation, guidance documents have been developed, which have only lately become available. According to the REACH annexes and supported by guidance documents, waiving of test requirements will be possible, thus, opening the possibility that under REACH no new (eco)toxicological data will be required. Concerning products, a guidance document was released in April 2008 stating that the substance concentration threshold of 0.1 % (w/w) applies to the article as produced or imported and it does not relate to the homogeneous materials or parts of an article, but relates to the article as such (i.e., as produced or imported). Hence, notification will not be required for many products containing chemicals with properties which place them on the candidate list for authorization. In summary, it is at present not foreseeable whether the expected benefit of the REACH legislation will materialise for the environment and for the health of consumers and at the work place.

  6. REACH-related substitution within the Danish printing industry

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Bøg, Carsten; Markussen, Helene

    are running a substitution project. A major part of the work has been mapping the presence of chemicals which are potential candidates for substitution (e.g. PBT, CMR, vPvB, EDS) within the Danish printing industry. The mapping comprises a combination of a literature study and an investigation of the actual......The accomplishment of the EU REACH regulation will most probably promote substitution within sectors handling a lot of different chemicals like the printing industry. With the aim of being at the cutting edge of this development the Danish EPA together with the Danish printing industry and IPU...... fulfil one or more of the criteria (e.g. CMR, EDS) for the REACH Annex XIV candidate list (authorisation). The paper presents the results of the mapping of chemical candidates and the first results of the actual substitutions. Keywords: REACH, chemicals, substitution, printing industry....

  7. Convergent optical wired and wireless long-reach access network using high spectral-efficient modulation.

    Science.gov (United States)

    Chow, C W; Lin, Y H

    2012-04-09

    To provide broadband services in a single and low cost perform, the convergent optical wired and wireless access network is promising. Here, we propose and demonstrate a convergent optical wired and wireless long-reach access networks based on orthogonal wavelength division multiplexing (WDM). Both the baseband signal and the radio-over-fiber (ROF) signal are multiplexed and de-multiplexed in optical domain, hence it is simple and the operation speed is not limited by the electronic bottleneck caused by the digital signal processing (DSP). Error-free de-multiplexing and down-conversion can be achieved for all the signals after 60 km (long-reach) fiber transmission. The scalability of the system for higher bit-rate (60 GHz) is also simulated and discussed.

  8. Composite Coiled Tubing for Extended Reach in Horizontal Oil Wells

    DEFF Research Database (Denmark)

    Costache, Andrei; Berggreen, Christian

    2017-01-01

    Conventional steel coiled tubing cannot reach along the entire length of very long horizontal oil wells. A lighter and more buoyant coiled tube is made possible using composite materials. The high stiffness to weight ratio of fiber reinforced polymers, coupled with a lower coefficient of friction......, has the potential of greatly extending the reach in horizontal oil wells. This study shows how to design composite coiled tubing and gives a comprehensive discussion about the most influential parameters. Several solutions, using glass-fiber and carbon are considered. Finite element models are used...

  9. Telerobotic operation of structurally flexible, long-reach manipulators

    International Nuclear Information System (INIS)

    Kwon, D.S.; Hwang, D.H.; Babcock, S.M.

    1994-01-01

    As a part of the Department of Energy's Environmental Restoration and Waste Management Program, long-reach manipulators are being considered for the retrieval of waste from large storage tanks. Long-reach manipulators may have characteristics significantly different from those of typical industrial robots because of the flexibility of long links needed to cover the large workspace. To avoid structural vibrations during operation, control algorithms employing various types of shaping filters were investigated. A new approach that uses embedded simulation was developed and compared with others. In the new approach, generation of joint trajectories considering link flexibility was also investigated

  10. Electronic technology

    International Nuclear Information System (INIS)

    Kim, Jin Su

    2010-07-01

    This book is composed of five chapters, which introduces electronic technology about understanding of electronic, electronic component, radio, electronic application, communication technology, semiconductor on its basic, free electron and hole, intrinsic semiconductor and semiconductor element, Diode such as PN junction diode, characteristic of junction diode, rectifier circuit and smoothing circuit, transistor on structure of transistor, characteristic of transistor and common emitter circuit, electronic application about electronic equipment, communication technology and education, robot technology and high electronic technology.

  11. Tokamak electron heat transport by direct numerical simulation of small scale turbulence; Transport de chaleur electronique dans un tokamak par simulation numerique directe d'une turbulence de petite echelle

    Energy Technology Data Exchange (ETDEWEB)

    Labit, B

    2002-10-01

    In a fusion machine, understanding plasma turbulence, which causes a degradation of the measured energy confinement time, would constitute a major progress in this field. In tokamaks, the measured ion and electron thermal conductivities are of comparable magnitude. The possible sources of turbulence are the temperature and density gradients occurring in a fusion plasma. Whereas the heat losses in the ion channel are reasonably well understood, the origin of the electron losses is more uncertain. In addition to the radial velocity associated to the fluctuations of the electric field, electrons are more affected than ions by the magnetic field fluctuations. In experiments, the confinement time can be conveniently expressed in terms of dimensionless parameters. Although still somewhat too imprecise, these scaling laws exhibit strong dependencies on the normalized pressure {beta} or the normalized Larmor radius, {rho}{sub *}. The present thesis assesses whether a tridimensional, electromagnetic, nonlinear fluid model of plasma turbulence driven by a specific instability can reproduce the dependence of the experimental electron heat losses on the dimensionless parameters {beta} and {rho}{sub *}. The investigated interchange instability is the Electron Temperature Gradient driven one (ETG). The model is built by using the set of Braginskii equations. The developed simulation code is global in the sense that a fixed heat flux is imposed at the inner boundary, leaving the gradients free to evolve. From the nonlinear simulations, we have put in light three characteristics for the ETG turbulence: the turbulent transport is essentially electrostatic; the potential and pressure fluctuations form radially elongated cells called streamers; the transport level is very low compared to the experimental values. The thermal transport dependence study has shown a very small role of the normalized pressure, which is in contradiction with the Ohkama's formula. On the other hand

  12. Work Element B: 157. Sampling in Fish-Bearing Reaches [Variation in Productivity in Headwater Reaches of the Wenatchee Subbasin], Final Report for PNW Research Station.

    Energy Technology Data Exchange (ETDEWEB)

    Polivka, Karl; Bennett, Rita L. [USDA Forest Service, Pacific Northwest Research Station, Wenatchee, WA

    2009-03-31

    We studied variation in productivity in headwater reaches of the Wenatchee subbasin for multiple field seasons with the objective that we could develop methods for monitoring headwater stream conditions at the subcatchment and stream levels, assign a landscape-scale context via the effects of geoclimatic parameters on biological productivity (macroinvertebrates and fish) and use this information to identify how variability in productivity measured in fishless headwaters is transmitted to fish communities in downstream habitats. In 2008, we addressed this final objective. In collaboration with the University of Alaska Fairbanks we found some broad differences in the production of aquatic macroinvertebrates and in fish abundance across categories that combine the effects of climate and management intensity within the subbasin (ecoregions). From a monitoring standpoint, production of benthic macroinvertebrates was not a good predictor of drifting macroinvertebrates and therefore might be a poor predictor of food resources available to fish. Indeed, there is occasionally a correlation between drifting macroinvertebrate abundance and fish abundance which suggests that headwater-derived resources are important. However, fish in the headwaters appeared to be strongly food-limited and there was no evidence that fishless headwaters provided a consistent subsidy to fish in reaches downstream. Fish abundance and population dynamics in first order headwaters may be linked with similar metrics further down the watershed. The relative strength of local dynamics and inputs into productivity may be constrained or augmented by large-scale biogeoclimatic control. Headwater streams are nested within watersheds, which are in turn nested within ecological subregions; thus, we hypothesized that local effects would not necessarily be mutually exclusive from large-scale influence. To test this we examined the density of primarily salmonid fishes at several spatial and temporal scales

  13. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  14. Studies towards the understanding of the effects of ionizing radiations at the molecular scale (20-150 keV H+/H + He Collisions; dissociative electron attachment to water)

    International Nuclear Information System (INIS)

    Coupier, B.

    2005-11-01

    This work comes within the scope of recent studies towards a better understanding of the effect of ionizing radiation at the molecular scale on biological systems. It is composed of two parts. The first one presents a new set of coincidence measurements of cross sections for the impact of protons or hydrogen atoms on helium in the energy range 20-150 keV of interest for the radiation biology. It is an archetypical system of interest for the theoreticians and there exists only a few studies on the impact of hydrogen atoms on helium. This study with helium was also motivated for the sake of performing a general test of functioning of the apparatus before investigating more complicated systems. Similar studies were then performed by replacing helium with water and biological molecules of relevance (Uracil, Thymine...) as target. This constitutes a study of direct effects of fast ionizing radiations on molecules of biological interest. The second part of the thesis deals with another type of ionizing radiations which can be seen as indirect effects of the first fast ionizing radiations studied in the first part. Low energy electrons emission in the energy range 1 to 16 eV follows the bombardment of the matter by swift protons/hydrogen atoms; these electrons have in turn an ionizing influence on the environment. A review of the dissociative electron attachment to water was undertaken motivated by the existing discrepancies between old studies on the same subject. A special attention was given to the problem of high energy kinetic ion discrimination in the trochoidal monochromator used for this work. (author)

  15. Agreement between paper and pen visual analogue scales and a wristwatch-based electronic appetite rating system (PRO-Diary©), for continuous monitoring of free-living subjective appetite sensations in 7-10 year old children.

    Science.gov (United States)

    Rumbold, P L S; Dodd-Reynolds, C J; Stevenson, E

    2013-10-01

    Electronic capture of free-living subjective appetite data can provide a more reliable alternative to traditional pen and paper visual analogue scales (P&P VAS), whilst reducing researcher workload. Consequently, the aim of this study was to explore the agreement between P&P VAS and a wristwatch-based electronic appetite rating system known as the PRO-Diary© technique, for monitoring free-living appetite sensations in 7-10 year old children. On one occasion, using a within-subject design, the 12 children (n=6 boys; n=6 girls) recorded their subjective appetite (hunger, prospective food consumption, and fullness), at two time points before lunch (11:30 and 12:00) and every 60 min thereafter until 21:00. The agreement between the P&P VAS and PRO-Diary© technique was explored using 95% limits of agreement and 95% confidence intervals (95% CI) calculated using the Bland and Altman (1986) technique. For hunger, prospective food consumption and fullness, the 95% limits of agreement were -1±25 mm (95% CI: lower limit -8mm; upper limit +6mm), 0±21 mm (95% CI: lower limit -6mm; upper limit +6mm) and -6±24 mm (95% CI: lower limit -14 mm; upper limit +1mm), respectively. Given the advantages associated with electronic data capture (inexpensive; integrated alarm; data easily downloaded), we conclude that the PRO-Diary© technique is an equivalent method to employ when continuously monitoring free-living appetite sensations in 7-10 year old children, but should not be used interchangeably with P&P VAS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Studies towards the understanding of the effects of ionizing radiations at the molecular scale (20-150 keV H{sup +}/H + He Collisions; dissociative electron attachment to water)

    Energy Technology Data Exchange (ETDEWEB)

    Coupier, B

    2005-11-15

    This work comes within the scope of recent studies towards a better understanding of the effect of ionizing radiation at the molecular scale on biological systems. It is composed of two parts. The first one presents a new set of coincidence measurements of cross sections for the impact of protons or hydrogen atoms on helium in the energy range 20-150 keV of interest for the radiation biology. It is an archetypical system of interest for the theoreticians and there exists only a few studies on the impact of hydrogen atoms on helium. This study with helium was also motivated for the sake of performing a general test of functioning of the apparatus before investigating more complicated systems. Similar studies were then performed by replacing helium with water and biological molecules of relevance (Uracil, Thymine...) as target. This constitutes a study of direct effects of fast ionizing radiations on molecules of biological interest. The second part of the thesis deals with another type of ionizing radiations which can be seen as indirect effects of the first fast ionizing radiations studied in the first part. Low energy electrons emission in the energy range 1 to 16 eV follows the bombardment of the matter by swift protons/hydrogen atoms; these electrons have in turn an ionizing influence on the environment. A review of the dissociative electron attachment to water was undertaken motivated by the existing discrepancies between old studies on the same subject. A special attention was given to the problem of high energy kinetic ion discrimination in the trochoidal monochromator used for this work. (author)

  17. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  18. Task-dependent vestibular feedback responses in reaching

    NARCIS (Netherlands)

    Keyser, J.; Medendorp, W.P.; Selen, L.P.J.

    2017-01-01

    When reaching for an earth-fixed object during self-rotation, the motor system should appropriately integrate vestibular signals and sensory predictions to compensate for the intervening motion and its induced inertial forces. While it is well established that this integration occurs rapidly, it is

  19. Reaching the Unreached - Special Emphasis on the Communication ...

    African Journals Online (AJOL)

    This paper provides an overview of the existing communication component in the Expanded Program on Immunisation (EPI) training in Zambia and critically analyses the need for a humane touch in the communication process so as to reach the target audience effectively. Interpersonal Communication (IPC) in Zambia has ...

  20. Shaping of Reach-to-Grasp Kinematics by Intentions

    DEFF Research Database (Denmark)

    Egmose, Ida; Køppe, Simo

    2017-01-01

    is primarily associated with transporting the hand to the object (i.e., extrinsic object properties), the decelerating part of the reach is used as a preparation for object manipulation (i.e., prepare the grasp or the subsequent action), and the grasp is associated with manipulating the object's intrinsic...

  1. Recognition for reaching the most vulnerable populations in Burkina ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Recognition for reaching the most vulnerable populations in Burkina Faso. 07 novembre 2016. An IDRC supported project was recognized for its efforts to improve health service provision and the monitoring of pregnant women, new mothers, children, and people living with HIV in Burkina Faso's Nouna district. Dr Maurice ...

  2. Object Permanence, Reaching, and Locomotion in Infants Who Are Blind.

    Science.gov (United States)

    Ross, S.; Tobin, M. J.

    1997-01-01

    The literature on the effects of congenital blindness on infants' development of motor functions and concepts of object permanence is reviewed. The article questions the idea that infants must first develop an object concept before sound clues alone will elicit reaching. Possible interventions to redress the effects of congenital blindness on…

  3. Reaching an understanding innovations in how we view reading assessment

    CERN Document Server

    Sabatini, John; O'Reilly, Tenaha

    2012-01-01

    Reaching an Understanding: Innovations in How We View Reading Assessment builds upon the editors previous book Measuring Up: Advances in How We Assess Reading Ability by representing some early attempts to apply theory to help guide the development of new assessments and measurement models.

  4. Nanshan Aluminum Reached Strategic Cooperation with CSR Corporation Limited

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    As a key supplier of aluminum profiles and aluminum plate,sheet and trip products for CSR Corporation Limited,Nanshan Aluminum will join hands with CSR Corporation Limited to reach strategic cooperation.On January 5,Nanshan Aluminum signed strategic cooperation agreement with CSR Sifang Locomotive&Rolling; Stock Co.,Ltd,both

  5. An Assessment of EU 2020 Strategy: Too Far to Reach?

    Science.gov (United States)

    Colak, Mehmet Selman; Ege, Aylin

    2013-01-01

    In 2010, EU adopted a new growth strategy which includes three growth priorities and five headline targets to be reached by 2020. The aim of this paper is to investigate the current performance of the EU member and candidate states in achieving these growth priorities and the overall strategy target by allocating the headline targets into the…

  6. Development of postural adjustments during reaching in infants with CP

    NARCIS (Netherlands)

    Hadders-Algra, M; van der Fits, IBM; Stremmelaar, EF; Touwen, BCL

    1999-01-01

    The development of postural adjustments during reaching movements was longitudinally studied in seven infants with cerebral palsy (CP) between 4 and 18 months of age. Five infants developed spastic hemiplegia, one spastic tetraplegia, and one spastic tetraplegia with athetosis. Each assessment

  7. Evaluation of the Implementation of the Reaching Every District ...

    African Journals Online (AJOL)

    46987.2

    ABSTRACT. Background: In 2003, the Government of Zambia in collaboration with implementing partners in immunisation introduced the Reaching Every District. (RED) strategy to improve immunization coverage. The aim of this study is to evaluate the implementation of the. RED strategy in Lusaka district. Methods: A ...

  8. Reach for the Stars: Visions for Literacy Coaching Programs

    Science.gov (United States)

    DeFord, Diane

    2012-01-01

    This brief by the Literacy Coaching Clearinghouse is about reaching for the stars--stories of vision and commitment from educators in small and large schools. Everyone knows of people who are held up as "visionaries" throughout history: Leonardo Da Vinci, Mahatma Gandhi, Jules Verne, Thomas Edison, Susan Anthony, or John Dewey, to name a few. The…

  9. Advanced reach tool (ART) : Development of the mechanistic model

    NARCIS (Netherlands)

    Fransman, W.; Tongeren, M. van; Cherrie, J.W.; Tischer, M.; Schneider, T.; Schinkel, J.; Kromhout, H.; Warren, N.; Goede, H.; Tielemans, E.

    2011-01-01

    This paper describes the development of the mechanistic model within a collaborative project, referred to as the Advanced REACH Tool (ART) project, to develop a tool to model inhalation exposure for workers sharing similar operational conditions across different industries and locations in Europe.

  10. Reaching the Summit: Deaf Adults as Essential Partners in Education

    Science.gov (United States)

    Bourne-Firl, Bridgetta

    2016-01-01

    How do we reach the summit in terms of supporting the best transition possible for each young deaf or hard of hearing individual in the United States? Should professionals who are hearing work alone to succeed with deaf and hard of hearing students? No matter how good the intention, if we want deaf and hard of hearing students to transition from…

  11. Reaching the Millennium Development Goals : Mauritania Should Care

    OpenAIRE

    Magnoli Bocchi, Alessandro; Pontara, Nicola; Fall, Khayar; Tejada, Catalina M.; Gallego Cuervo, Pablo

    2008-01-01

    Mauritania is a resource-rich developing country. As many other African nations, it will not reach most of the Millennium Development Goals, unless the authorities commit to accelerating progress. To succeed by 2015, the government needs to: mobilize additional financial resources, introduce policy changes at the sector level, and strengthen the links between strategic objectives and the b...

  12. Patterns of arm muscle activation involved in octopus reaching movements.

    Science.gov (United States)

    Gutfreund, Y; Flash, T; Fiorito, G; Hochner, B

    1998-08-01

    The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a target in a stereotyped manner using a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation [electromyogram (EMG)] was measured together with the kinematics of reaching movements. The traveling bend is associated with a propagating wave of muscle activation, with maximal muscle activation slightly preceding the traveling bend. Tonic activation was occasionally maintained afterward. Correlation of the EMG signals with the kinematic variables (velocities and accelerations) reveals that a significant part of the kinematic variability can be explained by the level of muscle activation. Furthermore, the EMG level measured during the initial stages of movement predicts the peak velocity attained toward the end of the reaching movement. These results suggest that feed-forward motor commands play an important role in the control of movement velocity and that simple adjustment of the excitation levels at the initial stages of the movement can set the velocity profile of the whole movement. A simple model of octopus arm extension is proposed in which the driving force is set initially and is then decreased in proportion to arm diameter at the bend. The model qualitatively reproduces the typical velocity profiles of octopus reaching movements, suggesting a simple control mechanism for bend propagation in the octopus arm.

  13. How infants' reaches reveal principles of sensorimotor decision making

    Science.gov (United States)

    Dineva, Evelina; Schöner, Gregor

    2018-01-01

    In Piaget's classical A-not-B-task, infants repeatedly make a sensorimotor decision to reach to one of two cued targets. Perseverative errors are induced by switching the cue from A to B, while spontaneous errors are unsolicited reaches to B when only A is cued. We argue that theoretical accounts of sensorimotor decision-making fail to address how motor decisions leave a memory trace that may impact future sensorimotor decisions. Instead, in extant neural models, perseveration is caused solely by the history of stimulation. We present a neural dynamic model of sensorimotor decision-making within the framework of Dynamic Field Theory, in which a dynamic instability amplifies fluctuations in neural activation into macroscopic, stable neural activation states that leave memory traces. The model predicts perseveration, but also a tendency to repeat spontaneous errors. To test the account, we pool data from several A-not-B experiments. A conditional probabilities analysis accounts quantitatively how motor decisions depend on the history of reaching. The results provide evidence for the interdependence among subsequent reaching decisions that is explained by the model, showing that by amplifying small differences in activation and affecting learning, decisions have consequences beyond the individual behavioural act.

  14. Advanced REACH tool: A Bayesian model for occupational exposure assessment

    NARCIS (Netherlands)

    McNally, K.; Warren, N.; Fransman, W.; Entink, R.K.; Schinkel, J.; Van Tongeren, M.; Cherrie, J.W.; Kromhout, H.; Schneider, T.; Tielemans, E.

    2014-01-01

    This paper describes a Bayesian model for the assessment of inhalation exposures in an occupational setting; the methodology underpins a freely available web-based application for exposure assessment, the Advanced REACH Tool (ART). The ART is a higher tier exposure tool that combines disparate

  15. On stiffening cables of a long reach manipulator

    International Nuclear Information System (INIS)

    Wang, S.L.; Santiago, P.

    1996-01-01

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator's slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator's stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator's wrist

  16. Challenges of extension workers in reaching rural women farmers in ...

    African Journals Online (AJOL)

    The study examined the challenges of extension workers in reaching rural women farmers in Enugu State Nigeria. Questionnaire was used to collect data from a sample size of 52 extension workers. Data were analyzed using percentage, mean statistic, chart and factor analysis. Results revealed that training and visit ...

  17. Quality, Reach, and Impact of Open Scholarly Publishing in Latin ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Quality, Reach, and Impact of Open Scholarly Publishing in Latin America. Better understanding Open Access of scholarly research will help determine how it contributes to the greater circulation of knowledge and disseminating research in Latin America. Open Access (defined as unrestricted access to articles published in ...

  18. The Internet and the Global Reach of EU law

    DEFF Research Database (Denmark)

    Kuner, Christopher Barth

    and learning; international negotiation; coercion and conditionality; and blocking recognition of third country legal measures. The EU’s actions in exercising its global reach implicate important normative issues, such as distinguishing between the furtherance of core EU legal values and the advancement...

  19. Task-dependent vestibular feedback responses in reaching.

    Science.gov (United States)

    Keyser, Johannes; Medendorp, W Pieter; Selen, Luc P J

    2017-07-01

    When reaching for an earth-fixed object during self-rotation, the motor system should appropriately integrate vestibular signals and sensory predictions to compensate for the intervening motion and its induced inertial forces. While it is well established that this integration occurs rapidly, it is unknown whether vestibular feedback is specifically processed dependent on the behavioral goal. Here, we studied whether vestibular signals evoke fixed responses with the aim to preserve the hand trajectory in space or are processed more flexibly, correcting trajectories only in task-relevant spatial dimensions. We used galvanic vestibular stimulation to perturb reaching movements toward a narrow or a wide target. Results show that the same vestibular stimulation led to smaller trajectory corrections to the wide than the narrow target. We interpret this reduced compensation as a task-dependent modulation of vestibular feedback responses, tuned to minimally intervene with the task-irrelevant dimension of the reach. These task-dependent vestibular feedback corrections are in accordance with a central prediction of optimal feedback control theory and mirror the sophistication seen in feedback responses to mechanical and visual perturbations of the upper limb. NEW & NOTEWORTHY Correcting limb movements for external perturbations is a hallmark of flexible sensorimotor behavior. While visual and mechanical perturbations are corrected in a task-dependent manner, it is unclear whether a vestibular perturbation, naturally arising when the body moves, is selectively processed in reach control. We show, using galvanic vestibular stimulation, that reach corrections to vestibular perturbations are task dependent, consistent with a prediction of optimal feedback control theory. Copyright © 2017 the American Physiological Society.

  20. Bimanual reach to grasp movements after cervical spinal cord injury.