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Sample records for access drifts test

  1. Test Particles, Test Modes and Drift Turbulence

    SciTech Connect

    Vlad, Madalina; Spineanu, Florin

    2008-10-15

    Strong electrostatic turbulence in magnetically confined plasmas is characterized by trapping or eddying of test particle trajectories produced by the ExB stochastic drift. Trapping is shown to produce non-standard statistics of trajectories: non-Gaussian distribution, memory effects and quasi-coherence. Two types of effects produced by trapping are analyzed. The first type concerns particle and energy transport and consists in very strong nonlinear modification of the diffusion coefficients. Anomalous diffusion regimes are obtained when the other components of the motion (particle collisions, plasma rotation, the motion along the confining magnetic field) do not destroy trajectory eddying. The second type of effects are evidenced by studying test modes on turbulent plasma. We show that trappyng provides the physical mechanism for the inverse cascade observed in drift turbulence.

  2. First quarter chemical borehole studies in the drift scale test

    SciTech Connect

    DeLoach, L., LLNL

    1998-05-19

    The chemistry boreholes of the Drift Scale Test (DST) have been designed to gather geochemical information and assess the impact of thermal perturbations on gas and liquid phases present in pore spaces and fractures within the rock. There are a total of ten boreholes dedicated to these chemical studies. Two arrays of five boreholes each were drilled from the access/observation drift (AOD) in planes which run normal to the heater drift and which are located approximately 15 and 45% of the way along the length of the drift as measured from the bulkhead. The boreholes each have a length of about 40 meters and have been drilled at low angles directed just above or just below the heater plane. In each array, three boreholes are directed at increasingly steeper angles (< 25-) above the line of wing heaters and two are directed at shallow angles below the wing heater plane.

  3. The Yucca Mountain Project drift scale test

    SciTech Connect

    Finley, R.E.; Blair, S.C.; Boyle, W.J.

    1998-06-01

    The Yucca Mountain Project is currently evaluating the coupled thermal-mechanical-hydrological-chemical (TMHC) response of the potential repository host rock through an in situ thermal testing program. A drift scale test (DST) was constructed during 1997 and heaters were turned on in December 1997. The DST includes nine canister-sized containers with thirty operating heaters each located within the heated drift (HD) and fifty wing heaters located in boreholes in both ribs with a total power output of nominally 210kW. A total of 147 boreholes (combined length of 3.3 km) houses most of the over 3700 TMHC sensors connected with 201 km of cabling to a central data acquisition system. The DST is located in the Exploratory Studies Facility in a 5-m diameter drift approximately 50 m in length. Heating will last up to four years and cooling will last another four years. The rock mass surrounding the DST will experience a harsh thermal environment with rock surface temperatures expected to reach a maximum of about 200 C. This paper describes the process of designing the DST. The first 38 m of the 50-m long Heated Drift (HD) is dedicated to collection of data that will lead to a better understanding of the complex coupled TMHC processes in the host rock of the proposed repository. The final 12 m is dedicated to evaluating the interactions between the heated rock mass and cast-in-place (CIP) concrete ground support systems at elevated temperatures. In addition to a description of the DST design, data from site characterization, and a general description of the analyses and analysis approach used to design the test and make pretest predictions are presented. Test-scoping and pretest numerical predictions of one way thermal-hydrologic, thermal-mechanical, and thermal-chemical behaviors have been completed (TRW, 1997a). These analyses suggest that a dry-out zone will be created around the DST and a 10,000 m{sup 3} volume of rock will experience temperatures above 100 C. The HD

  4. Yucca Mountain drift scale test progress report

    SciTech Connect

    Apps, J.; Birkholzer, J.T.; Peterson,J.E.; Sonnenthal, E.; Spycher, N.; Tsang, Y.W.; Williams, K.H.

    1999-01-01

    The Drift Scale Test (DST) is part of the Exploratory Studies Facility (ESF) Thermal Test being conducted underground at the potential high-level nuclear waste repository at Yucca Mountain, Nevada. The purpose of the ESF Thermal Test is to acquire a more in-depth understanding of the coupled thermal, mechanical, hydrological, and chemical processes likely to be encountered in the rock mass surrounding the potential geological repository at Yucca Mountain. These processes are monitored by a multitude of sensors to measure the temperature, humidity, gas pressure, and mechanical displacement, of the rock formation in response to the heat generated by the heaters. In addition to collecting passive monitoring data, active hydrological and geophysical testing is also being carried out periodically in the DST. These active tests are intended to monitor changes in the moisture redistribution in the rock mass, to collect water and gas samples for chemical and isotopic analysis, and to detect microfiacturing due to heating. On December 3, 1998, the heaters in the DST were activated. The planned heating phase of the DST is 4 years, and the cooling phase following the power shutoff will be of similar duration. The present report summarizes interpretation and analysis of thermal, hydrological, chemical, and geophysical data for the first 6 months; it is the first of many progress reports to be prepared during the DST.

  5. Spray drift reduction test method correlation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ASTM Standard E609 Terminology Relating to Pesticides defines drift as “The physical movement of an agrochemical through the air at the time of application or soon thereafter to any non or off target site.” Since there are many commercial tank mix adjuvants designed to reduce spray drift, ASTM esta...

  6. An overview of spray drift reduction testing of spray nozzles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of the development and testing of drift reduction technologies (DRTs) is increasing. Common spray drift reduction technologies include spray nozzles and spray adjuvants. Following draft procedures developed for a DRT program, three spray nozzles were tested under high air speed cond...

  7. Test of a high resolution drift chamber prototype

    NASA Astrophysics Data System (ADS)

    Commichau, V.; Deutschmann, M.; Draheim, K. J.; Fritze, P.; Hangarter, K.; Hawelka, P.; Herten, U.; Linnhöfer, D.; Tonutti, M.; Biermann, U.; Roderburg, E.; Walenta, A. H.; Anderhub, H.; Fehlmann, J.; Hofer, H.; Klein, M.; Paradiso, J. A.; Schreiber, J.; Viertel, G.

    1985-04-01

    The performance of a drift chamber prototype for a colliding beam vertex detector in a test beam at DESY is described. At one (two) atmosphere gas pressure a spatial resolution of 40 μm (30 μm) per wire for one cm drift length was achieved with a 100 MHz Flash-ADC system. An excellent double track resolution of better than 300 μm over the full drift length of 5 cm can be estimated.

  8. Analysis of Geomechanical Behavior for the Drift Scale Test

    SciTech Connect

    Blair, S C; Carlson, S R; Wagoner, J L

    2001-03-05

    The Drift Scale Test (DST) now underway at Yucca Mountain has been simulated using a Drift Scale Distinct Element (DSDE) model. Simulated deformations show good agreement with field deformation measurements. Results indicate most fracture deformation is located above the crown of the Heated Drift. This work is part of the model validation effort for the DSDE model, which is used to assess thermal-mechanical effects on the hydrology of the rock mass surrounding a potential repository.

  9. THERMAL TEST ALCOVE HEATED DRIFT GROUND SUPPORT ANALYSIS

    SciTech Connect

    S. Bonabian

    1996-10-03

    The main purpose and objective of this analysis is to analyze the stability of the Thermal Test Facility Heated Drift and to design a ground support system. The stability of the Heated Drift is analyzed considering in situ, seismic, and thermal loading conditions. A ground support system is recommended to provide a stable opening for the Heated Drift. This report summarizes the results of the analyses and provides the details of the recommended ground support system for the Heated Drift. The details of the ground support system are then incorporated into the design output documents for implementation in the field.

  10. Baseline neutron logging measurements in the drift scale test

    SciTech Connect

    Lin, W.; Carlson, R.; Neubaurer, D.

    1998-01-01

    The Drift Scale Test (DST) is one of the thermal tests being conducted in the Exploratory Studies Facility (ESF). One of the objectives of the DST is to study the coupled thermal-mechanical- hydrological-chemical (TMHC) processes in the ESF at the repository horizon of the potential high-level nuclear waste repository in Yucca Mountain, Nevada. The objectives, the test design, and the test layouts of the DST are included in the test design report by CRWMS M&O Contractor LLNL. The configuration of the DST includes a declining Observation Drift driven mostly east and downward from main tunnel in the ESF, at about 2.827 km from the North portal. The downward slope of the Observation Drift (11.5 to 14.0 percent) ensures a minimum 10 m of middle nonlithophysal Topopah Spring Tuff as the overburden for the DST. The length of the Observation Drift is about 136 m. At the elevation of the DST crown (nominally 10 m below the upper extent of the middle nonlithophysal Topopah Spring Tuff) the Connecting Drift breaks out to the north from the Observation Drift, 136 m from the main tunnel of the ESF. The Connecting Drift extends approximately 40 m to the north from the Observation Drift. A Heater Drift breaks out westward from the Connecting Drift at about 30 m from the Observation Drift. The Heater Drift consists of an 11 m long entry, which includes a plate- loading niche, and a 47 m long heated drift. The nominal diameter of the drifts is 5 m. The detail configuration of the DST, including diagrams showing the drift and borehole layout, is included in the test design report by CRWMS M&O Contractor LLNL. Thermal neutron logging is a method used to determine moisture content in rocks and soils and will be used to monitor moisture content in boreholes ESF-HD-NEU-1 to ESF-HD-NEU-10 (Boreholes 47 to 51 and 64 to 68), ESF-HD-TEMP-1 (Borehole 79), and ESF-HD-TEMP-2 (Borehole 80) in the DST. The neutron probe contains a source of high energy neutrons and a detector for slow (thermal

  11. Validation testing of drift reduction technology testing protocol

    EPA Science Inventory

    A number of pesticide application technologies offer the potential to reduce spray drift from pesticide applications. However, limited information exists on the effectiveness of these technologies in reducing spray drift. Working with a stakeholder technical panel under EPA's Env...

  12. Role of an encapsulating layer for reducing resistance drift in phase change random access memory

    NASA Astrophysics Data System (ADS)

    Jin, Bo; Kim, Jungsik; Pi, Dong-Hai; Kim, Hyoung Seop; Meyyappan, M.; Lee, Jeong-Soo

    2014-12-01

    Phase change random access memory (PCRAM) devices exhibit a steady increase in resistance in the amorphous phase upon aging and this resistance drift phenomenon directly affects the device reliability. A stress relaxation model is used here to study the effect of a device encapsulating layer material in addressing the resistance drift phenomenon in PCRAM. The resistance drift can be increased or decreased depending on the biaxial moduli of the phase change material (YPCM) and the encapsulating layer material (YELM) according to the stress relationship between them in the drift regime. The proposed model suggests that the resistance drift can be effectively reduced by selecting a proper material as an encapsulating layer. Moreover, our model explains that reducing the size of the phase change material (PCM) while fully reset and reducing the amorphous/crystalline ratio in PCM help to improve the resistance drift, and thus opens an avenue for highly reliable multilevel PCRAM applications.

  13. Analysis of geomechanical behavior for the drift scale test

    SciTech Connect

    Blair, S C; Carlson, S R; Wagoner, J L

    2000-11-17

    The Yucca Mountain Site Characterization Project is conducting a drift scale heater test, known as the Drift Scale Test (DST), in an alcove of the Exploratory Studies Facility at Yucca Mountain, Nevada. The DST is a large-scale, long-term thermal test designed to investigate coupled thermal-mechanical-hydrological-chemical behavior in a fractured, welded tuff rock mass. The general layout of the DST is shown in Figure 1a, along with the locations of several of the boreholes being used to monitor deformation during the test. Electric heaters are being used to heat a planar region of rock that is approximately 50 m long and 27 m wide for 4 years, followed by 4 years of cooling. Both in-drift and ''wing'' heaters are being used to heat the rock. The heating portion of the DST was started in December, 1997, and the target drift wall temperature of 200 C was reached in summer 2000. A drift-scale distinct element model (DSDE) is being used to analyze the geomechanical response of the rock mass forming the DST. The distinct element method was chosen to permit explicit modeling of fracture deformations. Shear deformations and normal mode opening of fractures are expected to increase fracture permeability and thereby alter thermal-hydrologic behavior in the DST. This paper will describe the DSDE model and present preliminary results, including comparison of simulated and observed deformations, at selected locations within the test.

  14. Detection of Item Parameter Drift over Multiple Test Administrations

    ERIC Educational Resources Information Center

    DeMars, Christine E.

    2004-01-01

    Three methods of detecting item drift were compared: the procedure in BILOG-MG for estimating linear trends in item difficulty, the CUSUM procedure that Veerkamp and Glas (2000) used to detect trends in difficulty or discrimination, and a modification of Kim, Cohen, and Park's (1995) x 2 test for multiple-group differential item functioning (DIF),…

  15. Drift scale test status report (Chapters 1-9)

    SciTech Connect

    Lin, W., LLNL

    1998-07-01

    The Drift-Scale Test (DST) is one of the thermal tests being conducted in the Exploratory Studies Facility (ESF) at Yucca Mountain, Nevada, site of the potential repository for high-level nuclear waste. One of the DST`s major objectives is to study the coupled thermal-hydrologic-chemical-mechanical (THCM) processes at the potential repository`s horizon. The objectives, test design, and test layouts of the DST are included in a previous test design report. this report present results and analysis of several difference measurements made in the DST by researchers at Lawrence Livermore National Laboratory through the second quarter of the heating phase. Sections 1.1 and 1.2 describe the layout of the DST and the boreholes and instrumentation used to monitor the THCM processes in the rock of associated drifts. Section 2 presents an analysis of temperature data for the test through the end of May 1998. Sections 3 and 4 present results of electrical resistance tomography and neutron logging measurements, respectively. These two sets of measurements are designed to determine the movement of moisture in the test. Results of a series of geochemical measurements made on gas and water samples are presented in Section 5. The purpose of these measurements is to monitor the chemical processes occurring in the DST. Section 6 presents results of thermohydrologic modeling analysis of the test, and Section 7 presents data collected via the laboratory testing for characterization of the hydrologic properties of the rock forming the DST. A brief analysis of barometric pressure and humidity data collected through the end of May 1998 is discussed in Section 8, along with temperature data for the bulkhead. Finally, Section 9 presented an evaluation of sensors used in the DST.

  16. Scale model testing of drogues for free drifting buoys

    NASA Technical Reports Server (NTRS)

    Vachon, W. A.

    1973-01-01

    Instrumented model drogue tests were conducted in a ship model towing tank. The purpose of the tests was to observe and measure deployment and drag characteristics of such shapes as parachutes, crossed vanes, and window shades which may be employed in conjunction with free drifting buoys. Both Froude and Reynolds scaling laws were applied while scaling to full scale relative velocities of from 0 to 0.2 knots. A weighted window shade drogue is recommended because of its performance, high drag coefficient, simplicity, and low cost. Detailed theoretical performance curves are presented for parachutes, crossed vanes, and window shade drogues. Theoretical estimates of depth locking accuracy and buoy-induced dynamic loads pertinent to window shade drogues are presented as a design aid. An example of a window shade drogue design is presented.

  17. Testing the concept of drift shadow at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Paces, J.B.; Neymark, L.A.; Ghezzehei, T.; Dobson, P.F.

    2006-01-01

    If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain, To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or 238U-234U-230Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All rock samples show 234U depletion relative to parent 238U indicating varying degrees of water-rock interaction over the past million years. Variations in 234U/238U activity ratios indicate that depletion of 234U relative to 238U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of 234U/ 238U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors.

  18. Testing the Concept of Drift Shadow at Yucca Mountain, Nevada

    SciTech Connect

    J.B. Paces; L.A. Neymark; T. Ghezzehei; P.F. Dobson

    2006-03-10

    If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain. To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or {sup 238}U-{sup 234}U-{sup 230}Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All samples show {sup 234}U depletion relative to parent {sup 238}U, indicating varying degrees of water-rock interaction over the past million years. Variations in {sup 234}U/{sup 238}U activity ratios indicate that depletion of {sup 234}U relative to {sup 238}U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of {sup 234}U/{sup 238}U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors.

  19. THE DRIFT SCALE HEATER TEST AT YUCCA MOUNTAIN, NEVADA

    SciTech Connect

    Peters, Mark T.; Boyle, William J.; Datta, Robin N.; Elkins, Ned Z.; Yasek, Robert N.; Wagner, Ralph A.; Weaver, Douglas J.

    1998-01-30

    The Drift Scale Heater Test (DST) is an integral part of the program of testing and studies being conducted by the U.S. Department of Energy to evaluate the suitability of Yucca Mountain, Nevada as a site of a deep geologic repository for the permanent disposal of spent nuclear fuel and high-level nuclear waste. The DST is a large-scale, in situ thermal test to be conducted over nearly a decade in the Exploratory Studies Facility at Yucca Mountain (Figure 1). The overall objective of the DST is to acquire a more indepth understanding of the physical processes that will occur in the rock surrounding the emplaced waste. There are four principal processes of concern: thermal, mechanical, hydrological, and chemical. These processes will be intensified because of the decay heat from the emplaced waste and their interaction or coupling. An understanding of these coupled processes is essential for the assessment of the long-term (over thousands of years) performance of the repository.

  20. Drift Wave Test Particle Transport in Reversed Shear Profile

    SciTech Connect

    Horton, W.; Park, H.B.; Kwon, J.M.; Stronzzi, D.; Morrison, P.J.; Choi, D.I.

    1998-06-01

    Drift wave maps, area preserving maps that describe the motion of charged particles in drift waves, are derived. The maps allow the integration of particle orbits on the long time scale needed to describe transport. Calculations using the drift wave maps show that dramatic improvement in the particle confinement, in the presence of a given level and spectrum of E x B turbulence, can occur for q(r)-profiles with reversed shear. A similar reduction in the transport, i.e. one that is independent of the turbulence, is observed in the presence of an equilibrium radial electric field with shear. The transport reduction, caused by the combined effects of radial electric field shear and both monotonic and reversed shear magnetic q-profiles, is also investigated.

  1. A Stepwise Test Characteristic Curve Method to Detect Item Parameter Drift

    ERIC Educational Resources Information Center

    Guo, Rui; Zheng, Yi; Chang, Hua-Hua

    2015-01-01

    An important assumption of item response theory is item parameter invariance. Sometimes, however, item parameters are not invariant across different test administrations due to factors other than sampling error; this phenomenon is termed item parameter drift. Several methods have been developed to detect drifted items. However, most of the…

  2. Spray drift reduction evaluations of spray nozzles using a standardized testing protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development and testing of drift reduction technologies has come to the forefront of application research in the past few years in the United States. Drift reduction technologies (DRTs) can be spray nozzles, sprayer modifications, spray delivery assistance, spray property modifiers (adjuvants),...

  3. Definitive test of the Rh = ct universe using redshift drift

    NASA Astrophysics Data System (ADS)

    Melia, Fulvio

    2016-11-01

    The redshift drift of objects moving in the Hubble flow has been proposed as a powerful model-independent probe of the underlying cosmology. A measurement of the first- and second-order redshift derivatives appears to be well within the reach of upcoming surveys using as the Extremely Large Telescope high resolution spectrometer (ELT-HIRES) and the Square Kilometer Phase 2 Array (SKA). Here we show that an unambiguous prediction of the Rh = ct cosmology is zero drift at all redshifts, contrasting sharply with all other models in which the expansion rate is variable. For example, multiyear monitoring of sources at redshift z = 5 with the ELT-HIRES is expected to show a velocity shift Δv = -15 cm s-1 yr-1 due to the redshift drift in Planck ΛCDM, while Δv = 0 cm s-1 yr-1 in Rh = ct. With an anticipated ELT-HIRES measurement error of ±5 cm s-1 yr-1 after 5 yr, these upcoming redshift drift measurements might therefore be able to differentiate between Rh = ct and Planck ΛCDM at ˜3σ, assuming that any possible source evolution is well understood. Such a result would provide the strongest evidence yet in favour of the Rh = ct cosmology. With a 20-yr baseline, these observations could favour one of these models over the other at better than 5σ.

  4. Test particle study of ion transport in drift type turbulence

    SciTech Connect

    Vlad, M.; Spineanu, F.

    2013-12-15

    Ion transport regimes in drift type turbulence are determined in the frame of a realistic model for the turbulence spectrum based on numerical simulations. The model includes the drift of the potential with the effective diamagnetic velocity, turbulence anisotropy, and dominant waves. The effects of the zonal flow modes are also analyzed. A semi-analytical method that is able to describe trajectory stochastic trapping or eddying is used for obtaining the transport coefficients as function of the parameters of the turbulence. Analytical approximations of the transport coefficients are derived from the results. They show the transition from Bohm to gyro-Bohm scaling as plasma size increases in very good agreement with the numerical simulations.

  5. Generic Verification Protocol for Testing Pesticide Application Spray Drift Reduction Technologies for Row and Field Crops

    EPA Pesticide Factsheets

    This generic verification protocol provides a detailed method to conduct and report results from a verification test of pesticide application technologies that can be used to evaluate these technologies for their potential to reduce spray drift.

  6. Geology of the U-1a. 01 horizontal drift complex, southwestern Yucca Flat, Nevada Test Site

    SciTech Connect

    Drellack, S.L. Jr.; Thompson, P.H.; Rayburn, C.J.

    1989-03-01

    The U-1a.01 complex, site of a Los Alamos National Laboratory-sponsored experiment, is located in southwestern Yucca Flat on the Nevada Test Site. The complex is comprised of the vertical U-1a shaft, two large-diameter cable access holes, and approximately 229 m (750') of horizontal drift mined within alluvium 292.6 m (960') below the surface. Geologic mapping and related work at U-1a.01 afforded a unique opportunity to observe and evaluate the characteristics of alluvium in the subsurface of Yucca Flat, and to compare the results with surface and drill hole alluvium data. The Los Alamos Support Group of the Fenix and Scisson, Inc. Geology and Hydrology Division carried out a program of mapping, sampling and photography while mining was in progress, with the dual purpose of characterizing the geology of the site and documenting the mining operation. This report details the products and the results of that effort. 12 refs., 8 figs., 25 tabs.

  7. Model and test in a fungus of the probability that beneficial mutations survive drift.

    PubMed

    Gifford, Danna R; de Visser, J Arjan G M; Wahl, Lindi M

    2013-02-23

    Determining the probability of fixation of beneficial mutations is critically important for building predictive models of adaptive evolution. Despite considerable theoretical work, models of fixation probability have stood untested for nearly a century. However, recent advances in experimental and theoretical techniques permit the development of models with testable predictions. We developed a new model for the probability of surviving genetic drift, a major component of fixation probability, for novel beneficial mutations in the fungus Aspergillus nidulans, based on the life-history characteristics of its colony growth on a solid surface. We tested the model by measuring the probability of surviving drift in 11 adapted strains introduced into wild-type populations of different densities. We found that the probability of surviving drift increased with mutant invasion fitness, and decreased with wild-type density, as expected. The model accurately predicted the survival probability for the majority of mutants, yielding one of the first direct tests of the extinction probability of beneficial mutations.

  8. The Effect of Anchor Test Construction on Scale Drift

    ERIC Educational Resources Information Center

    Antal, Judit; Proctor, Thomas P.; Melican, Gerald J.

    2014-01-01

    In common-item equating the anchor block is generally built to represent a miniature form of the total test in terms of content and statistical specifications. The statistical properties frequently reflect equal mean and spread of item difficulty. Sinharay and Holland (2007) suggested that the requirement for equal spread of difficulty may be too…

  9. Geographic variation in advertisement calls of a Microhylid frog - testing the role of drift and ecology.

    PubMed

    Lee, Ko-Huan; Shaner, Pei-Jen L; Lin, Yen-Po; Lin, Si-Min

    2016-05-01

    Acoustic signals for mating are important traits that could drive population differentiation and speciation. Ecology may play a role in acoustic divergence through direct selection (e.g., local adaptation to abiotic environment), constraint of correlated traits (e.g., acoustic traits linked to another trait under selection), and/or interspecific competition (e.g., character displacement). However, genetic drift alone can also drive acoustic divergence. It is not always easy to differentiate the role of ecology versus drift in acoustic divergence. In this study, we tested the role of ecology and drift in shaping geographic variation in the advertisement calls of Microhyla fissipes. We examined three predictions based on ecological processes: (1) the correlation between temperature and call properties across M. fissipes populations; (2) the correlation between call properties and body size across M. fissipes populations; and (3) reproductive character displacement (RCD) in call properties between M. fissipes populations that are sympatric with and allopatric to a congener M. heymonsi. To test genetic drift, we examined correlations among call divergence, geographic distance, and genetic distance across M. fissipes populations. We recorded the advertisement calls from 11 populations of M. fissipes in Taiwan, five of which are sympatrically distributed with M. heymonsi. We found geographic variation in both temporal and spectral properties of the advertisement calls of M. fissipes. However, the call properties were not correlated with local temperature or the callers' body size. Furthermore, we did not detect RCD. By contrast, call divergence, geographic distance, and genetic distance between M. fissipes populations were all positively correlated. The comparisons between phenotypic Q st (P st) and F st values did not show significant differences, suggesting a role of drift. We concluded that genetic drift, rather than ecological processes, is the more likely

  10. Temperature as a diagnostic for the drift scale test

    SciTech Connect

    Lin, W; Wagoner, J; Ballard, S

    2000-10-31

    The United States Department of Energy (DOE) is investigating Yucca Mountain, Nevada, for its feasibility as a potential deep geological repository of high-level nuclear waste. In a deep geological repository, the radioactive decay heat released from high-level nuclear waste will heat up the rock mass. The heat will mobilize pore water in the rock mass by evaporation, and even boiling, if the thermal load is great enough. The water vapor/steam will flow away from the heat source because of pressure and thermal gradients and the effects of buoyancy force. The vapor/steam may flow along fractures or highly permeable zones and condense into liquid water in the cooler regions. Gravity and fracture network will control the drainage of the condensed water. Some of the water may flow back toward the waste package and reevaporated. This thermal-hydrological (TH) process will affect the amount of water that may come into contact with the waste package. Water is the main concern for the integrity of the waste package and the waste form, and the potential transport of radioactive nuclides. Thermally driven chemical and mechanical processes may affect the TH process. The coupled thermal-hydrological-mechanical-chemical (THMC) processes need to be understood before the performance of a repository can be adequately predicted. DOE is conducting field thermal tests to provide data for validating the model of the coupled THMC processes. Therefore, understanding the processes revealed by a field thermal test is essential for the model validation. This paper presents examples that temperature measurement is an effective tool for understanding the TH process.

  11. Construction and cosmic-ray test of the new inner drift chamber for BESIII

    NASA Astrophysics Data System (ADS)

    Xie, Yong-ji; Qin, Zhong-hua; Ma, Xiao-yan; Zhang, Jian; Wu, Ling-hui; Xie, Wan; Dong, Ming-yi; Dong, Jing; Ji, Xiao-lu; Jiang, Xiao-shan; Ou-yang, Qun; Zhu, Ke-jun; Chen, Yuan-bo

    2016-09-01

    A new inner drift chamber has been built which can replace the aged part of the BESIII drift chamber when needed. The design of the new inner drift chamber can minimize the ineffective area in the very forward and backward region and hence reduce the background event rate. With this design, the new inner drift chamber is expected to have a longer lifetime and improved performance due to the lower occupancy. The endplates and the cylinder were machined with high precision. Wire stringing was performed after the mechanical structure was assembled, and good quality of wire stringing was ensured by measurement of the tension and leakage current of the wires. After completion of the physical construction of the new chamber, a cosmic-ray test was carried out to test its performance. The results of the cosmic-ray test show that the new inner chamber achieves a spatial resolution of 127 μm and a dE/dx resolution of 6.4%, which satisfies the design specifications.

  12. Coupled Thermal-Hydrologic-Chemical Coupled Model for In-Drift Disposal Test

    SciTech Connect

    Jordan, Amy B.; Zyvoloski, George Anthony; Weaver, Douglas James; Otto, Shawn; Stauffer, Philip H.

    2016-09-06

    The simulation work presented in this report supports DOE-NE Used Fuel Disposition Campaign (UFDC) goals related to the development of drift scale in-situ field testing of heat-generating nuclear waste (HGNW) in salt formations. Numerical code verification and validation is an important part of the lead-up to field testing, allowing exploration of potential heater emplacement designs, monitoring locations, and perhaps most importantly the ability to predict heat and mass transfer around an evolving test. Such predictions are crucial for the design and location of sampling and monitoring that can be used to validate our understanding of a drift scale test that is likely to span several years.

  13. Electrical resistivity monitoring of the drift scale test in Yucca Mountain

    SciTech Connect

    Ramirez, A.

    1997-01-13

    Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Eight boreholes, containing a total of 140 ERT electrodes, were drilled above and below the Heated Drift (HD) to form vertical planes parallel to the drift. In addition, 4 boreholes, containing 60 electrodes, drilled from the Access Observation Drift (AOD) form vertical planes at right angles to the HD. Four ERT surveys, three before and one after heating began, were conducted during the first quarter of FY 98. Tomographic images of absolute electrical resistivity have been calculated using these data and are presented in this report. The report also presents the coordinates of the electrodes used for the ERT surveys. Future reports will include images of electrical resistivity change calculated using data collected before and during the heating episode. The changes to be recovered will then be used in combination with temperature maps of the region to calculate maps of saturation change around the HD.

  14. Generic Verification Protocol for Testing Pesticide Application Spray Drift Reduction Technologies for Row and Field Crops (Version 1.4)

    EPA Science Inventory

    This generic verification protocol provides a detailed method for conducting and reporting results from verification testing of pesticide application technologies. It can be used to evaluate technologies for their potential to reduce spray drift, hence the term “drift reduction t...

  15. Effects of Item Parameter Drift on Vertical Scaling with the Nonequivalent Groups with Anchor Test (NEAT) Design

    ERIC Educational Resources Information Center

    Ye, Meng; Xin, Tao

    2014-01-01

    The authors explored the effects of drifting common items on vertical scaling within the higher order framework of item parameter drift (IPD). The results showed that if IPD occurred between a pair of test levels, the scaling performance started to deviate from the ideal state, as indicated by bias of scaling. When there were two items drifting…

  16. Test Review: ACCESS for ELLs[R

    ERIC Educational Resources Information Center

    Fox, Janna; Fairbairn, Shelley

    2011-01-01

    This article reviews Assessing Comprehension and Communication in English State-to-State for English Language Learners ("ACCESS for ELLs"[R]), which is a large-scale, high-stakes, standards-based, and criterion-referenced English language proficiency test administered in the USA annually to more than 840,000 English Language Learners (ELLs), in…

  17. Generating equally weighted test particles from the one-way flux of a drifting Maxwellian

    NASA Astrophysics Data System (ADS)

    Makkonen, T.; Airila, M. I.; Kurki-Suonio, T.

    2015-01-01

    The problem of generating equally weighted test particles from the one way flux of drifting Maxwellian is tackled. This paper extends previous work on the subject by presenting a simple and efficient rejection sampling algorithm together with C++ source files. The properties of the underlying probability distribution function, having the form of a normal distribution times x with positive support, are also disseminated. The method presented in this paper has been successfully used to combine fluid and kinetic models for trace impurity problems in plasma physics.

  18. Coupled THM Simulations of the Drift Scale Test at Yucca Mountain

    SciTech Connect

    Blair, S C; Carlson, S R; Lee, K; Wagoner, J L

    2002-03-08

    This paper presents a coupled thermal-hydrological-mechanical (THM) analysis of the Drift Scale Test (DST) conducted at Yucca Mountain, Nevada. The DST is a large-scale, long-term thermal test designed to investigate coupled thermal-mechanical-hydrological-chemical behavior in a fractured, welded tuff rock mass in support of nuclear waste isolation efforts. The model used for this analysis utilizes temperature distributions predicted by a thermal-hydrological code as input to a distinct element thermal mechanical code. This paper presents a brief discussion of the test and the coupled model, followed by comparison of predicted and measured displacements. Results show that the model predicts the trend and magnitude of the displacements observed in a cross section monitored in the test through four years of heating. Maximum principal stress levels of 60 MPa are predicted in the crown and floor of the heated drift (HD) after 4 years of heating. Comparison of predicted and observed displacements shows that the model closely predicts vertical displacement above the HD and provides a good estimate of horizontal displacement perpendicular to the HD. These results indicate that a thermal expansion coefficient of 9e-6/{Lambda}C is generally appropriate for the rockmass forming this test. Normal displacements on joints in the cross section examined here show opening of up to 2mm on subvertical fractures in regions above and below the HD after 4 years of heating. These fractures do not close upon cooldown, indicating that some permanent enhancement of vertical fracture permeability may occur.

  19. THERMAL MECHANICAL ANALYSIS OF THE DRIFT SCALE TEST VIA DISTINCT ELEMENT MODELING

    SciTech Connect

    S. Blair; J. Wagoner; K. Dyer

    2000-12-08

    We have performed a thermal mechanical analysis of the Drift Scale Test (DST) currently underway at Yucca Mountain. The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada, as a potential repository for high-level nuclear waste. The purpose of the DST is to acquire a more in-depth understanding of coupled Thermal-Mechanical-Hydrological-Chemical (TMHC) processes likely to exist in the rock mass surrounding a potential geologic repository at Yucca Mountain. Moreover, the DST is located in a highly fractured and densely welded ash-flow tuff, and movement of fluids in this rock is thought to occur primarily through the fractures. Our work is concerned with describing fracture deformation due to thermal mechanical effects, as normal and shear deformation of fractures can substantially change the fracture permeability, and affect the coupled TMHC behavior. We modeled the DST by defining a rectangular rock mass 50m x 50m x 100m in size. The rock mass was formed by an assemblage of discrete, elastic blocks. Excavations within the DST were closely simulated, and discrete fractures mapped from video logs of several boreholes in the DST test block were incorporated. Stress boundary conditions were used on the top and sides of the rock mass, while the bottom was considered a roller boundary. Thermal inputs were based on the test design specifications. Results of the simulations show good agreement with deformations measured in the DST using multiple-point borehole extensometers. Our analysis also indicates that the most fracture deformation occurs above the drift, and co-located with micro seismic activity and acoustic emissions observed during the DST. Results to be presented include predicted temperature and stress fields, fracture displacements, and comparison between observed and predicted displacements at specific locations in the test. Maps of fractures in the DST test block will also be presented.

  20. Examining the Impact of Drifted Polytomous Anchor Items on Test Characteristic Curve (TCC) Linking and IRT True Score Equating. Research Report. ETS RR-12-09

    ERIC Educational Resources Information Center

    Li, Yanmei

    2012-01-01

    In a common-item (anchor) equating design, the common items should be evaluated for item parameter drift. Drifted items are often removed. For a test that contains mostly dichotomous items and only a small number of polytomous items, removing some drifted polytomous anchor items may result in anchor sets that no longer resemble mini-versions of…

  1. Experimental test of the mass dependence of the heuristic drift model

    NASA Astrophysics Data System (ADS)

    Makowski, M. A.; Osborne, T. H.; Leonard, A. W.; Bortolon, A.; Nazikian, R.

    2016-10-01

    An empirical scaling for the heat flux scrape-off-layer (SOL) width has been developed, but the physics setting the heat flux width has yet to be established. However, a heuristic model for the width scaling has been developed which is consistent with currently available data. Recent experiments in helium discharges and in which the pedestal and SOL had > 75 % impurity (He, Li, C, N, or Ne) content, provide a means of testing the mass scaling of the heuristic model. Preliminary results indicate either no or a weakly negative scaling of the measured heat flux width with mass. This result lies between the predicted approximate √{ A / Z } (electron drift dominated) and √{ A /Z3 } (ion drift dominated) dependencies predicted by the model, indicating a complicated interplay between the electrons and multiple ion species present in the SOL. These and other results related to the heuristic model will be presented. Supported by US DOE under DE AC52 07NA27344, DE-FC02-04ER54698, and DE-AC02-09CH11466.

  2. Design and implementation of the detector control system for the BESIII drift chamber cosmic ray test

    NASA Astrophysics Data System (ADS)

    Chen, Xi-Hui; Xie, Xiao-Xi; Li, Xiao-Nan; Gao, Cui-Shan; Zhang, Yin-Hong; Nie, Zhen-Dong; Min, Jian; Xie, Yi-GANG

    2008-08-01

    After the construction of the BESIII drift chamber, a long period of cosmic rays test is necessary to verify its performance. This also provides a good opportunity to integrate the detector readout electronics and Detector Control System (DCS) into a unified working system. The goal of the DCS is to guarantee reliable physics data quality and the safe operation of the detector. It monitors and controls the HV, gas, VME crates and the environmental variables. The upper-level system is mainly developed from LabVIEW and the lower-level system mainly uses MCU and PLC technology. The system is designed to be highly flexible and scalable so that it can be applied to other detectors with little or no change. In the immediate future, it will be integrated into the entire BESIII Slow Control System.

  3. The central drift chamber for the D0 experiment: Design, construction and test

    SciTech Connect

    Behnke, T.

    1989-08-01

    A cylindrical drift chamber has been designed and built at the State University of New York at Stony Brook. This chamber is to be installed in the D0 detector which is being completed at the Fermi National Accelerator. In this dissertation the design, construction and testing of this chamber are described. The characteristic features of this chamber are cells formed by solid walls and a modular structure. Much discussion is given to the performance of and results from a chamber made from three final modules which was installed in the D0 interaction region during the 1988/1989 collider run. Using this chamber proton anti-proton interactions were measured at the D0 interaction point.

  4. Commissioning of the first drift tube linac module in the Ground Test Accelerator

    SciTech Connect

    Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Cole, R.; Connolly, R.; Denney, P.; Erickson, J.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Kraus, R.; Lysenko, W.P.; McMurry, D.; Mottershead, C.T.; Power, J.; Rose, C.; Rusthoi, D.P.; Sandoval, D.P.; Schneider, J.D.; Smith, M.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

    1993-06-01

    The Ground Test Accelerator (GTA) has the objective of verifying much of the technology required for producing high-brightness, high-current H{sup {minus}} beams. GTA commissioning is staged to verify the beam-dynamics design of each major accelerator component as it is brought on-line. The major components are the 35-keV H{sup {minus}} injector, the 2.5-MeV radio-frequency quadrupole (RFQ), the intertank matching section (IMS), the 3.2 MeV first 2{beta}{lambda} drift tube linac (DTL-1) module, and the 24-MeV GTA with 10 DTL modules. Results from the DTL-1 beam experiments will be presented.

  5. Ground Control for Non-Emplacement Drifts for LA

    SciTech Connect

    D. Tang

    2004-02-26

    The purpose of this calculation is to analyze the stability of repository non-emplacement drifts during the preclosure period, and to provide a final ground support method for non-emplacement drifts for the License Application (LA). This calculation will provide input for the development of LA documents. The scope of this calculation is limited to the non-emplacement drifts including access mains, ramps, exhaust mains, turnouts, intersections between access mains and turnouts, and intersections between exhaust mains and emplacement drifts, portals, TBM launch chambers, observation drift and test alcove in the performance confirmation (PC) facilities, etc. The calculation is limited to the non-emplacement drifts subjected to a combined loading of in-situ stress, seismic stress, and/or thermal stress. Other effects such as hydrological and chemical effects are not considered in this analysis.

  6. Impact of genetic drift on access and benefit sharing under the Nagoya Protocol: the case of the Meishan pig.

    PubMed

    Blackburn, H D; Plante, Y; Rohrer, G; Welch, E W; Paiva, S R

    2014-04-01

    Genetic drift (GD) randomly impacts small breeds and imported populations. Therefore, it can impact policies that affect conservation of animal genetic resources. This paper evaluates GD for a population of Meishan pigs imported into the United States and explores the ramifications of GD on access and benefit sharing of genetic resources under the Nagoya Protocol (NP) of the United Nations' Convention on Biological Diversity. The NP was motivated by concerns about fair and equitable benefit sharing of genetic resources across life forms. In this experiment, 35 microsatellite markers were used to quantify the level of GD that occurred between Meishan pigs (Meishan-China; n = 22) imported into the United States in the late 1980s and contemporary Meishan (Meishan-US; n = 42), which have been randomly bred since importation. The Meishan-US consisted of 2 subpopulations (Meishan-MARC and Meishan-ISU). Five other breeds were also included in the analysis to serve as reference populations: Fengjing and Minzhu, which were imported with Meishan-China, and Duroc, Berkshire, and Yorkshire from the United States. Mean shift in allele frequency was 0.11 (SE = 0.019) due to GD for Meishan-US vs. Meishan-China with some loci having changed allele frequencies by greater than 0.20. Principle coordinate analysis confirmed divergence among the Meishan populations. Model-based clustering tended to place the U.S. and Chinese breeds into 2 distinct clusters, likely due to differences in allele frequencies between U.S. and Chinese breeds. Contemporary Meishan-US has become differentiated from the original imported animals due to GD. Attributing future performance of Meishan-US to Meishan-China, as set forth by NP, is problematic due to GD. As an imported breed becomes established there will be an increasing number of breeders who may have different selection goals and private treaty contracts will govern the exchange of stock between them. Therefore, considering biological phenomena and

  7. DEVELOPMENT OF A TEST PLAN TO VERIFY PESTICIDE DRIFT REDUCTION TECHNOLOGIES

    EPA Science Inventory

    Considerable research has taken place in recent years to determine the sources, pathways, and exposure to the environment from airborne pesticide spray which can often drift off target at the time of spray application. Verification of the effectiveness of pesticide spray drift r...

  8. Remotely accessible laboratory for MEMS testing

    NASA Astrophysics Data System (ADS)

    Sivakumar, Ganapathy; Mulsow, Matthew; Melinger, Aaron; Lacouture, Shelby; Dallas, Tim E.

    2010-02-01

    We report on the construction of a remotely accessible and interactive laboratory for testing microdevices (aka: MicroElectroMechancial Systems - MEMS). Enabling expanded utilization of microdevices for research, commercial, and educational purposes is very important for driving the creation of future MEMS devices and applications. Unfortunately, the relatively high costs associated with MEMS devices and testing infrastructure makes widespread access to the world of MEMS difficult. The creation of a virtual lab to control and actuate MEMS devices over the internet helps spread knowledge to a larger audience. A host laboratory has been established that contains a digital microscope, microdevices, controllers, and computers that can be logged into through the internet. The overall layout of the tele-operated MEMS laboratory system can be divided into two major parts: the server side and the client side. The server-side is present at Texas Tech University, and hosts a server machine that runs the Linux operating system and is used for interfacing the MEMS lab with the outside world via internet. The controls from the clients are transferred to the lab side through the server interface. The server interacts with the electronics required to drive the MEMS devices using a range of National Instruments hardware and LabView Virtual Instruments. An optical microscope (100 ×) with a CCD video camera is used to capture images of the operating MEMS. The server broadcasts the live video stream over the internet to the clients through the website. When the button is pressed on the website, the MEMS device responds and the video stream shows the movement in close to real time.

  9. Evaluation of a proposed drift reduction technology high-speed wind tunnel testing protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Environmental Protection Agency (EPA) has initiated the development of protocols for for measuring spray drift reduction technologies (DRTs) related to the application of agricultural protection chemicals. The DRT Program is an EPA-led initiative program to “achieve improved environmental ...

  10. Method and apparatus for globally-accessible automated testing

    DOEpatents

    Layne, Scott P.; Beugelsdijk, Tony J.

    1998-01-01

    A method and apparatus for sharing integrated testing services with a plurality of autonomous remote clients is disclosed. In the disclosed method, in response to an access request message, a process controller transmits an access enabling message to the remote client. The access enabling message includes instructions performable by a remote client to generate test equipment commands. A process controller interprets and transforms these commands into automated test instrument suite commands, which are provided to laboratory modules to perform the indicated tests. Test data results are then obtained and transmitted to the remote client.

  11. 9. ENGINE TEST CELL BUILDING INTERIOR. CELL ACCESS ELEVATOR, CELLS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. ENGINE TEST CELL BUILDING INTERIOR. CELL ACCESS ELEVATOR, CELLS 2 AND 4, BASEMENT LEVEL. LOOKING SOUTHEAST. - Fairchild Air Force Base, Engine Test Cell Building, Near intersection of Arnold Street & George Avenue, Spokane, Spokane County, WA

  12. Construction and test of new precision drift-tube chambers for the ATLAS muon spectrometer

    NASA Astrophysics Data System (ADS)

    Kroha, H.; Kortner, O.; Schmidt-Sommerfeld, K.; Takasugi, E.

    2017-02-01

    ATLAS muon detector upgrades aim for increased acceptance for muon triggering and precision tracking and for improved rate capability of the muon chambers in the high-background regions of the detector with increasing LHC luminosity. The small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half of the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages of the MDTs, but have an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, minimizing construction time and personnel. Sense wire positioning accuracies of 5 μm have been achieved in serial production for large-size chambers comprising several hundred drift tubes. The construction of new sMDT chambers for installation in the 2016/17 winter shutdown of the LHC and the design of sMDT chambers in combination with new RPC trigger chambers for replacement of the inner layer of the barrel muon spectrometer are in progress.

  13. Impact of genetic drift on access and benefit sharing under the Nagoya protocol: The case of the Meishan pig

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Convention on Biological Diversity developed the Nagoya Protocol (NP) on access and benefit sharing (ABS) for international exchange of genetic resources. Concerns are NP will impose new costs for exchanging livestock genetic resources and interfere with commonly used private treaty contracts. N...

  14. Low drift type N thermocouples in out-of-pile advanced gas reactor mock-up test: metallurgical analysis

    SciTech Connect

    Scervini, M.; Palmer, J.; Haggard, D.C.; Swank, W.D.

    2015-07-01

    Thermocouples are the most commonly used sensors for temperature measurement in nuclear reactors. They are crucial for the control of current nuclear reactors and for the development of GEN IV reactors. In nuclear applications thermocouples are strongly affected by intense neutron fluxes. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. Thermocouple drift can be very significant for in-pile temperature measurements and may render the temperature sensors unreliable after exposure to nuclear radiation for relatively short times compared to the life required for temperature sensors in nuclear applications. Previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of Nickel based thermocouples is limited to temperatures lower than 1000 deg. C due to drift related to phenomena other than nuclear irradiation. As part of a collaboration between Idaho National Laboratory (INL) and the University of Cambridge a variety of Type N thermocouples have been exposed at INL in an Advanced Gas Reactor mock-up test at 1150 deg. C for 2000 h, 1200 deg. C for 2000 h, 125 deg. C for 200 h and 1300 deg. C for 200 h, and later analysed metallurgically at the University of Cambridge. The use of electron microscopy allows to identify the metallurgical changes occurring in the thermocouples during high temperature exposure and correlate the time dependent thermocouple drift with the microscopic changes experienced by the thermoelements of different thermocouple designs. In this paper conventional Inconel 600 sheathed type N thermocouples and a type N using a customized sheath developed at the University of

  15. Using Operational Analysis to Improve Access to Pulmonary Function Testing

    PubMed Central

    Ip, Ada; Asamoah-Barnieh, Raymond; Bischak, Diane P.; Davidson, Warren J.; Flemons, W. Ward; Pendharkar, Sachin R.

    2016-01-01

    Background. Timely pulmonary function testing is crucial to improving diagnosis and treatment of pulmonary diseases. Perceptions of poor access at an academic pulmonary function laboratory prompted analysis of system demand and capacity to identify factors contributing to poor access. Methods. Surveys and interviews identified stakeholder perspectives on operational processes and access challenges. Retrospective data on testing demand and resource capacity was analyzed to understand utilization of testing resources. Results. Qualitative analysis demonstrated that stakeholder groups had discrepant views on access and capacity in the laboratory. Mean daily resource utilization was 0.64 (SD 0.15), with monthly average utilization consistently less than 0.75. Reserved testing slots for subspecialty clinics were poorly utilized, leaving many testing slots unfilled. When subspecialty demand exceeded number of reserved slots, there was sufficient capacity in the pulmonary function schedule to accommodate added demand. Findings were shared with stakeholders and influenced scheduling process improvements. Conclusion. This study highlights the importance of operational data to identify causes of poor access, guide system decision-making, and determine effects of improvement initiatives in a variety of healthcare settings. Importantly, simple operational analysis can help to improve efficiency of health systems with little or no added financial investment. PMID:27445545

  16. Test/QA plan for the validation of the verification protocol for low speed pesticide spray drift reduction technologies for row and field crops

    EPA Science Inventory

    This test/QA plan for evaluation the generic test protocol for high speed wind tunnel, representing aerial application, pesticide spray drift reduction technologies (DRT) for row and field crops is in conformance with EPA Requirements for Quality Assurance Project Plans (EPA QA/R...

  17. Test/QA plan for the validation of the verification protocol for high speed pesticide spray drift reduction technologies for row and field crops

    EPA Science Inventory

    This test/QA plan for evaluation the generic test protocol for high speed wind tunnel, representing aerial application, pesticide spray drift reduction technologies (DRT) for row and field crops is in conformance with EPA Requirements for Quality Assurance Project Plans (EPA QA/R...

  18. A system to test the effects of materials on the electron drift lifetime in liquid argon and observations on the effect of water

    SciTech Connect

    Andrews, R.; Jaskierny, W.; Jostlein, H.; Kendziora, C.; Pordes, S.; Tope, T.; /Fermilab

    2009-07-01

    A materials test system (MTS) has been developed at FNAL to assess the suitability of materials for use in a large liquid argon time projection chamber. During development of the MTS, it was noted that controlling the cryostat pressure with a 'raining' condenser reduced the electron drift lifetime in the liquid argon. The effect of condensing has been investigated using a series of passive materials to filter the condensate. We report the results of these studies and of tests on different candidate materials for detector construction. The inferred reduction of electron drift lifetime by water concentrations in the parts per trillion is of particular interest.

  19. Drift Scale THM Model

    SciTech Connect

    J. Rutqvist

    2004-10-07

    drift to transport any exposed radionuclides out of the drift to the groundwater below, and eventually to people within the accessible environment. Absent sufficient water, radionuclides cannot be transported and there would be no significant health effect on people, even if radioactive waste containers were damaged or corroded to such an extent that radionuclides were exposed to water.

  20. Test of Continental Drift by Comparison of Radiometric Ages: A pre-drift reconstruction shows matching geologic age provinces in West Africa and Northern Brazil.

    PubMed

    Hurley, P M; Rand, J R; Pinson, W H; Fairbairn, H W; de Almeida, F F; Melcher, G C; Cordani, U G; Kawashita, K; Vandoros, P

    1967-08-04

    1) The distribution of age values obtained by potassium-argon determinations and whole-rock rubidium-strontium determinations appears to be almost identical for West African rocks of the pervasive Eburnean Orogenic Cycle and basement rocks at opposite locations in South America. 2) There is also a close correlation, with respect to potassium-argon age determinations on micas, rubidium-strontium determinations on total-rock samples, and the extent to which these two sets of values differ, between rocks of the Pan-African Orogenic Cycle and rocks of the Caririan Orogenic Cycle in Brazil, where these two groups of rocks lie opposite each other in the two continents. 3) When Africa and South America are "fitted together," the sharply defined boundary between the Eburnean and the Pan-African age provinces in West Africa strikes directly toward the corresponding age boundary in northeast Brazil. 4) The transition from the 550-million-year Pan-African age province to the 2000-million-year age province in the Congo Craton in Cameroun-Gabon is matched in the rocks near the corresponding part of the east coast of Brazil. However the geological and age data are insufficient to do more than suggest the possibility of another age-boundary correlation here. 5) The evidence reported here supports the hypothesis of continental drift.

  1. Uncertainties in coupled thermal-hydrological processes associated with the drift scale test at Yucca Mountain, Nevada

    SciTech Connect

    Mukhopadhyay, Sumitra; Tsang, Y.W.

    2002-09-01

    Understanding thermally driven coupled hydrological, mechanical, and chemical processes in unsaturated fractured tuff is essential for evaluating the performance of the potential radioactive waste repository at Yucca Mountain, Nevada. The Drift Scale Test (DST), intended for acquiring such an understanding of these processes, has generated a huge volume of temperature and moisture redistribution data. Sophisticated thermal hydrological (TH) conceptual models have yielded a good fit between simulation results and those measured data. However, some uncertainties in understanding the TH processes associated with the DST still exist. This paper evaluates these uncertainties and provides quantitative estimates of the range of these uncertainties. Of particular interest for the DST are the uncertainties resulting from the unmonitored loss of vapor through an open bulkhead of the test. There was concern that the outcome from the test might have been significantly altered by these losses. Using alternative conceptual models, we illustrate that predicted mean temperatures from the DST are within 1 degree C of the measured mean temperatures through the first two years of heating. The simulated spatial and temporal evolution of drying and condensation fronts is found to be qualitatively consistent with measured saturation data. Energy and mass balance computation shows that no more than 13 percent of the input energy is lost because of vapor leaving the test domain through the bulkhead. The change in average saturation in fractures is also relatively small. For a hypothetical situation in which no vapor is allowed to exit through the bulkhead, the simulated average fracture saturation is not qualitatively different enough to be discerned by measured moisture redistribution data. This leads us to conclude that the DST, despite the uncertainties associated with open field testing, has provided an excellent understanding of the TH processes.

  2. Coupled Analysis of Change in Fracture Permeability during the Cooling Phase of the Yucca Mountain Drift Scale Test

    SciTech Connect

    Rutqvist, Jonny; Rutqvist, J.; Freifeld, B.; Tsang, Y.W.; Min, K.B.; Elsworth, D.

    2008-06-01

    This paper presents results from a coupled thermal, hydrological and mechanical analysis of thermally-induced permeability changes during heating and cooling of fractured volcanic rock at the Drift Scale Test at Yucca Mountain, Nevada. The analysis extends the previous analysis of the four-year heating phase to include newly available data from the subsequent four year cooling phase. The new analysis of the cooling phase shows that the measured changes in fracture permeability follows that of a thermo-hydro-elastic model on average, but at several locations the measured permeability indicates (inelastic) irreversible behavior. At the end of the cooling phase, the air-permeability had decreased at some locations (to as low as 0.2 of initial), whereas it had increased at other locations (to as high as 1.8 of initial). Our analysis shows that such irreversible changes in fracture permeability are consistent with either inelastic fracture shear dilation (where permeability increased) or inelastic fracture surface asperity shortening (where permeability decreased). These data are important for bounding model predictions of potential thermally-induced changes in rock-mass permeability at a future repository at Yucca Mountain.

  3. A Conceptual and Numerical Model for Thermal-Hydrological-Chemical Processes in the Yucca Mountain Drift Scale Test

    SciTech Connect

    Sonnenthal, Eric L.; Spycher, Nicolas F.; Conrad, Mark; Apps, John

    2003-07-01

    A numerical model was developed to predict the coupled thermal, hydrological, and chemical (THC) processes accompanying the Drift Scale Test (DST) at Yucca Mountain, NV. The DST has been closely monitored through the collection of gas, water, and mineral samples as well as thermal, hydrological, and mechanical measurements. A two-dimensional dual permeability model was developed to evaluate multiphase, multicomponent, reaction-transport processes in the fractured tuff. Comparisons between results using the TOUGHREACT code and measured water (e.g., pH, SiO2(aq), Na+, K+) and gas (CO2) compositions show that the model captures the chemical evolution in the DST. Non-reactive aqueous species (e.g., Cl) show strong dilution in fracture waters, indicating little fracture-matrix interaction. Silica concentrations are higher than in the initial pore water and show a trend of increasing reaction with fracture-lining silicates at higher temperatures. The narrow precipitation zone of predominantly amorphous silica observed above the heaters was also captured.

  4. Analysis of Coupled Multiphase Fluid Flow, Heat Transfer and Mechanical Deformation at the Yucca Mountain Drift Scale Test

    SciTech Connect

    J. Rutqvist; C.F. Tsang; Y. Tsang

    2005-05-17

    A numerical simulation of coupled multiphase fluid flow, heat transfer, and mechanical deformation was carried out to study coupled thermal-hydrological-mechanical (THM) processes at the Yucca Mountain Drift Scale Test (DST) and for validation of a coupled THM numerical simulator. The ability of the numerical simulator to model relevant coupled THM processes at the DST was evaluated by comparison of numerical results to in situ measurements of temperature, water saturation, displacement, and fracture permeability. Of particular relevance for coupled THM processes are thermally induced rock-mass stress and deformations, with associated changes in fracture aperture and fractured rock permeability. Thermally induced rock-mass deformation and accompanying changes in fracture permeability were reasonably well predicted using a continuum elastic model, although some individual measurements of displacement and permeability indicate inelastic mechanical responses. It is concluded that fracture closure/opening caused by a change in thermally induced normal stress across fractures is an important mechanism for changes in intrinsic fracture permeability at the DST, whereas fracture shear dilation appears to be less significant. Observed and predicted maximum permeability changes at the DST are within one order of magnitude. These data are important for bounding model predictions of potential changes in rock-mass permeability at a future repository in Yucca Mountain.

  5. Gender and care: access to HIV testing, care, and treatment.

    PubMed

    Remien, Robert H; Chowdhury, Jenifar; Mokhbat, Jacques E; Soliman, Cherif; Adawy, Maha El; El-Sadr, Wafaa

    2009-07-01

    HIV transmission and occurrence of AIDS in the Middle East and North Africa region (MENA) is increasing, while access to ART in the region lags behind most low to middle-income countries. Like in other parts of the world, there is a growing feminization of the epidemic, and men and women each confront unique barriers to adequate HIV prevention and treatment services, while sharing some common obstacles as well. This paper focuses on important gender dimensions of access to HIV testing, care and treatment in the MENA region, including issues related to stigma, religion and morality, gender power imbalances, work status, and migration. Culturally specific policy and programmatic recommendations for improving HIV prevention and treatment in the MENA region are offered.

  6. Estimation of host rock thermal conductivities using thetemperature data from the drift-scale test at Yucca Mountain,Nevada

    SciTech Connect

    Mukhopadhyay, Sumitra; Tsang, Y.W.

    2003-11-25

    A large volume of temperature data has been collected from a very large, underground heater test, the Drift Scale Test (DST) at Yucca Mountain, Nevada. The DST was designed to obtain thermal, hydrological, mechanical, and chemical (THMC) data in the unsaturated fractured rock of Yucca Mountain. Sophisticated numerical models have been developed to analyze the collected THMC data. In these analyses, thermal conductivities measured from core samples have been used as input parameters to the model. However, it was not known whether these core measurements represented the true field-scale thermal conductivity of the host rock. Realizing these difficulties, elaborate, computationally intensive geostatistical simulations have also been performed to obtain field-scale thermal conductivity of the host rock from the core measurements. In this paper, we use the temperature data from the DST as the input (instead of the measured core-scale thermal conductivity values) to develop an estimate of the field-scale thermal conductivity values. Assuming a conductive thermal regime, we develop an analytical solution for the temperature rise in the host rock of the DST; and using a nonlinear fitting routine, we obtain a best-fit estimate of field-scale thermal conductivity for the DST host rock. The temperature data collected from the DST shows clear evidence of two distinct thermal regimes: a zone below boiling (wet) and a zone above boiling (dry). We obtain estimates of thermal conductivity for both the wet and dry zones. We also analyze the sensitivity of these estimates to the input heating power of the DST.

  7. Spiral silicon drift detectors

    SciTech Connect

    Rehak, P.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Lutz, G.; Kemmer, J.; Prechtel, U.; Ziemann, T.

    1988-01-01

    An advanced large area silicon photodiode (and x-ray detector), called Spiral Drift Detector, was designed, produced and tested. The Spiral Detector belongs to the family of silicon drift detectors and is an improvement of the well known Cylindrical Drift Detector. In both detectors, signal electrons created in silicon by fast charged particles or photons are drifting toward a practically point-like collection anode. The capacitance of the anode is therefore kept at the minimum (0.1pF). The concentric rings of the cylindrical detector are replaced by a continuous spiral in the new detector. The spiral geometry detector design leads to a decrease of the detector leakage current. In the spiral detector all electrons generated at the silicon-silicon oxide interface are collected on a guard sink rather than contributing to the detector leakage current. The decrease of the leakage current reduces the parallel noise of the detector. This decrease of the leakage current and the very small capacities of the detector anode with a capacitively matched preamplifier may improve the energy resolution of Spiral Drift Detectors operating at room temperature down to about 50 electrons rms. This resolution is in the range attainable at present only by cooled semiconductor detectors. 5 refs., 10 figs.

  8. Progress in semiconductor drift detectors

    SciTech Connect

    Rehak, P.; Walton, J.; Gatti, E.; Longoni, A.; Sanpietro, M.; Kemmer, J.; Dietl, H.; Holl, P.; Klanner, R.; Lutz, G.

    1985-01-01

    Progress in testing semiconductor drift detectors is reported. Generally better position and energy resolutions were obtained than resolutions published previously. The improvement is mostly due to new electronics better matched to different detectors. It is shown that semiconductor drift detectors are becoming versatile and reliable detectors for position and energy measurements.

  9. Test report: Low cost access and efficient use of TDRSS

    NASA Technical Reports Server (NTRS)

    Horan, S.

    1996-01-01

    In order to develop new ways to increase the number of users taking advantage of NASA's Space Network for space-to-ground communications links, researchers at New Mexico State University (NMSU) developed a technique for using non-gimballed antennas for accessing a Tracking and Data Relay Satellite (TDRS) within the Space Network (SN). This concept would allow spin-stabilized satellites to access one of the TDRS spacecraft in the SN constellation as the user satellite sweeps past the TDRS position as the satellite approaches either its ascending or descending node if this node is relatively close to the TDRS subsatellite point. ne research team from NMSU developing this concept proposed to NASA the use of the Extreme Ultra Violet Explorer (EUVE) to test this concept on orbit. EUVE differs from the desired satellite configuration in that EUVE has a relatively high-gain parabolic antenna and, most importantly, EUVE has an inertially-stabilized attitude control system while the concept to be tested was for a spin-stabilized satellite. We believed that these limitations would not affect the basic proof-of-concept test we were trying to achieve. With the approval and coordination of NASA, a total of six satellite passes through the West TDRS were requested and the necessary equipment configured for data collection at the Second TDRS Ground Terminal (STGT), also known as Danzante, at the White Sands Complex.

  10. Testing the validity of conflict drift-diffusion models for use in estimating cognitive processes: A parameter-recovery study.

    PubMed

    White, Corey N; Servant, Mathieu; Logan, Gordon D

    2017-03-29

    Researchers and clinicians are interested in estimating individual differences in the ability to process conflicting information. Conflict processing is typically assessed by comparing behavioral measures like RTs or error rates from conflict tasks. However, these measures are hard to interpret because they can be influenced by additional processes like response caution or bias. This limitation can be circumvented by employing cognitive models to decompose behavioral data into components of underlying decision processes, providing better specificity for investigating individual differences. A new class of drift-diffusion models has been developed for conflict tasks, presenting a potential tool to improve analysis of individual differences in conflict processing. However, measures from these models have not been validated for use in experiments with limited data collection. The present study assessed the validity of these models with a parameter-recovery study to determine whether and under what circumstances the models provide valid measures of cognitive processing. Three models were tested: the dual-stage two-phase model (Hübner, Steinhauser, & Lehle, Psychological Review, 117(3), 759-784, 2010), the shrinking spotlight model (White, Ratcliff, & Starns, Cognitive Psychology, 63(4), 210-238, 2011), and the diffusion model for conflict tasks (Ulrich, Schröter, Leuthold, & Birngruber, Cogntive Psychology, 78, 148-174, 2015). The validity of the model parameters was assessed using different methods of fitting the data and different numbers of trials. The results show that each model has limitations in recovering valid parameters, but they can be mitigated by adding constraints to the model. Practical recommendations are provided for when and how each model can be used to analyze data and provide measures of processing in conflict tasks.

  11. Development and Testing of a Laboratory Spray Table Methodology to Bioassay Simulated Levels of Aerial Spray Drift

    DTIC Science & Technology

    2009-05-01

    3 Teske , M. E., and Thistle, H. W., “A Simulation of Release Height and Wind Speed Effects for Drift Minimization,” Trans. ASAE, Vol. 42, 1999, pp...and Teske , M. E., “Evaluation of the AgDISP Aerial Spray Algorithms in the AgDRIFT Model,” Envir. Toxicol. Chem., Vol. 21, 2002, pp. 672–681. 14... Teske , M. E., Vanner, A. L., and Coker, G. W. R., “Validation of SpraySafe Manager, an Aerial Herbicide Application Decision Support System,” Can. J

  12. Availability, accessibility, and affordability of neurodiagnostic tests in 37 countries

    PubMed Central

    McLane, Hannah C.; Berkowitz, Aaron L.; Patenaude, Bryan N.; McKenzie, Erica D.; Wolper, Emma; Wahlster, Sarah; Fink, Günther

    2015-01-01

    Objective: To determine the availability, accessibility, and affordability of EEG, EMG, CSF analysis, head CT, and brain MRI for neurologic disorders across countries. Methods: An online, 60-question survey was distributed to neurology practitioners in 2014 to assess the presence, wait time, and cost of each test in private and public health sectors. Data were stratified by World Bank country income group. Affordability was calculated with reference to the World Health Organization's definition of catastrophic health expenditure as health-related out-of-pocket expenditure of >40% of disposable household income, and assessment of providers' perceptions of affordability to the patient. Results: Availability of EEG and EMG is correlated with higher World Bank income group (correlation coefficient 0.38, test for trend p = 0.046; 0.376, p = 0.043); CSF, CT, and MRI did not show statistically significant associations with income groups. Patients in public systems wait longer for neurodiagnostic tests, especially MRI, EEG, and urgent CT (p < 0.0001). The mean cost per test, across all tests, was lower in the public vs private sector (US $55.25 vs $214.62, p < 0.001). Each drop in World Bank income group is associated with a 29% decrease in the estimated share of the population who can afford a given test (95% confidence interval −33.4, 25.2; p < 0.001). In most low-income countries surveyed, only the top 10% or 20% of the population was able to afford tests below catastrophic levels. In surveyed lower-middle-income countries, >40% of the population, on average, could not afford neurodiagnostic tests. Conclusions: Neurodiagnostic tests are least affordable in the lowest income settings. Closing this “diagnostic gap” for countries with the lowest incomes is essential. PMID:26446063

  13. Microgravity access as a means for testing therapeutic pharmaceutics

    NASA Astrophysics Data System (ADS)

    Zimmerman, Robert J.; Simske, Steven J.

    1995-01-01

    Spaceflight results in a unique combination of physiological effects. Immune, musculoskeletal, cardiovascular, renal and other physiological systems are deleteriously affected by the microgravity environment. Many of these effects are analogous to diseases that afflict people on earth; for instance, immunosuppressive disorders and osteoporosis. Chiron Corporation (Emeryville, CA) is interested in using spaceflight as a testing ground for its unique therapeutic pharmaceutics. On STS-60 (Feb. 1994), Chiron, heading up a consortium managed by its CCDS (Center for the Commercial Development of Space) partner Bioserve Space Technologies, investigated the effects of its recombinant interleukin-2 (IL-2) pharmaceutic on preventing the immune system suppression induced that mimicked spaceflight (tail suspension). The recombinant, pegulated IL-2 largely prevented the deleterious effects of spaceflight and particularly suspension on the development of macrophages and the spleen. Based on these findings, Chiron hopes to expand its original market for Il-2 to include veterinary applications. In future missions, Chiron hopes to further explore the physiological effects of IL-2 in preventing the spaceflight effects (STS-63), and to use spaceflight access as a means for testing drugs which may be useful for the treatment of other diseases (e.g., M-CSF for osteoporosis). Spaceflight access has provided Chiron with new applications and new approaches for determining the effects of their pharmaceutics.

  14. Approaches to modeling coupled thermal, hydrological, and chemicalprocesses in the Drift Scale Heater Test at Yucca Mountain.

    SciTech Connect

    Sonnenthal, E.; Ito, K.; Spycher, N.; Yui, M.; Apps, J.; Sugita,Y.; Conrad, M.; Kawakami, S.

    2005-03-01

    A large-scale underground thermal test (Drift Scale Test DST) in fractured volcanic tuff resulted in changes to water and gas chemistry as well as mineral precipitation and dissolution in fractures. Thermal, hydrological, and chemical (THC) processes in the DST were modeled by Lawrence Berkeley National Laboratory ''LBNL'' and Japan Nuclear Cycle Development Institute ''JNC'' as part of the international working group DECOVALEX. Predictions of THC processes in the DST for the 4-year heating and 4-year cooling periods were initially performed by the LBNL group, with the current model reflecting a revised heater operation history and model. JNC used primarily the original data from the prediction and created a new model to evaluate a selected set of data. The approaches taken by the groups differed in several ways and a comparison of the methodologies and results of the simulations allow for a better understanding of modeling coupled processes in unsaturated fractured rock. The LBNL model represented the fractures and rock matrix as a fully interacting dual-continuum (in terms of fluid, heat, and chemical transport) with the local mineral water gas reactions treated by kinetic and equilibrium reactions. The JNC model represented the fractures and matrix as a single effective continuum, with equilibrium mineral-water reactions controlling the chemical evolution. Both models considered aqueous species transport, with gas phase CO2 transport only considered in the LBNL model. Comparisons to data collected from the DST illustrate the behavior of the models and their ability to capture the relevant THC processes. Overall, both models capture the temperature evolution in the rock quite closely, although the JNC model gave a closer match to the initial temperature rise in the rock, likely owing to the use of site-specific thermal data as opposed to average properties used for the LBNL model. Both models showed the contrasting solubility effects of increasing temperature on

  15. Design and test of a vascular access device.

    PubMed

    Verkerke, G J; Rakhorst, G

    2000-05-01

    Transarterial left ventricular assist devices (LVADs), such as the Hemopump, IABP, and PUCA-pump, are meant to be introduced into the body via the femoral or axillary artery without major surgery. For certain applications, introduction is performed directly into the aorta via an open thorax procedure. A prototype of a vascular access device has been realized that allows direct access into the aorta as an alternative for the common surgical graft anastomosis suturing technique. The device consists of a metal tube acting as a circular knife to cut a hole in the aortic wall, a screw to store the removed part of the aortic wall, and a plastic tube that is introduced through the hole and tightly connected to the aortic wall. The device could be placed without aortic clamping. The device has been tested on a slaughterhouse porcine aorta. A low-pressurized aorta appeared to be the worst case; thus, two animal experiments in the low-pressurized pulmonary artery were performed. No leakage occurred for pressures between 40 and 300 mm Hg.

  16. The effects of nonuniform magnetic field strength on density flux and test particle transport in drift wave turbulence

    SciTech Connect

    Dewhurst, J. M.; Hnat, B.; Dendy, R. O.

    2009-07-15

    The extended Hasegawa-Wakatani equations generate fully nonlinear self-consistent solutions for coupled density n and vorticity {nabla}{sup 2}{phi}, where {phi} is electrostatic potential, in a plasma with background density inhomogeneity {kappa}=-{partial_derivative} ln n{sub 0}/{partial_derivative}x and magnetic field strength inhomogeneity C=-{partial_derivative} ln B/{partial_derivative}x. Finite C introduces interchange effects and {nabla}B drifts into the framework of drift turbulence through compressibility of the ExB and diamagnetic drifts. This paper addresses the direct computation of the radial ExB density flux {gamma}{sub n}=-n{partial_derivative}{phi}/{partial_derivative}y, tracer particle transport, the statistical properties of the turbulent fluctuations that drive {gamma}{sub n} and tracer motion, and analytical underpinnings. Systematic trends emerge in the dependence on C of the skewness of the distribution of pointwise {gamma}{sub n} and in the relative phase of density-velocity and density-potential pairings. It is shown how these effects, together with conservation of potential vorticity {pi}={nabla}{sup 2}{phi}-n+({kappa}-C)x, account for much of the transport phenomenology. Simple analytical arguments yield a Fickian relation {gamma}{sub n}=({kappa}-C)D{sub x} between the radial density flux {gamma}{sub n} and the radial tracer diffusivity D{sub x}, which is shown to explain key trends in the simulations.

  17. Geographic Variation in the Acoustic Traits of Greater Horseshoe Bats: Testing the Importance of Drift and Ecological Selection in Evolutionary Processes

    PubMed Central

    Sun, Keping; Luo, Li; Kimball, Rebecca T.; Wei, Xuewen; Jin, Longru; Jiang, Tinglei; Li, Guohong; Feng, Jiang

    2013-01-01

    Patterns of intraspecific geographic variation of signaling systems provide insight into the microevolutionary processes driving phenotypic divergence. The acoustic calls of bats are sensitive to diverse evolutionary forces, but processes that shape call variation are largely unexplored. In China, Rhinolophus ferrumequinum displays a diverse call frequency and inhabits a heterogeneous landscape, presenting an excellent opportunity for this kind of research. We quantified geographic variation in resting frequency (RF) of echolocation calls, estimated genetic structure and phylogeny of R. ferrumequinum populations, and combined this with climatic factors to test three hypotheses to explain acoustic variation: genetic drift, cultural drift, and local adaptation. Our results demonstrated significant regional divergence in frequency and phylogeny among the bat populations in China's northeast (NE), central-east (CE) and southwest (SW) regions. The CE region had higher frequencies than the NE and SW regions. Drivers of RF divergence were estimated in the entire range and just the CE/NE region (since these two regions form a clade). In both cases, RF divergence was not correlated with mtDNA or nDNA genetic distance, but was significantly correlated with geographic distance and mean annual temperature, indicating cultural drift and ecological selection pressures are likely important in shaping RF divergence among different regions in China. PMID:23950926

  18. Geographic variation in the acoustic traits of greater horseshoe bats: testing the importance of drift and ecological selection in evolutionary processes.

    PubMed

    Sun, Keping; Luo, Li; Kimball, Rebecca T; Wei, Xuewen; Jin, Longru; Jiang, Tinglei; Li, Guohong; Feng, Jiang

    2013-01-01

    Patterns of intraspecific geographic variation of signaling systems provide insight into the microevolutionary processes driving phenotypic divergence. The acoustic calls of bats are sensitive to diverse evolutionary forces, but processes that shape call variation are largely unexplored. In China, Rhinolophus ferrumequinum displays a diverse call frequency and inhabits a heterogeneous landscape, presenting an excellent opportunity for this kind of research. We quantified geographic variation in resting frequency (RF) of echolocation calls, estimated genetic structure and phylogeny of R. ferrumequinum populations, and combined this with climatic factors to test three hypotheses to explain acoustic variation: genetic drift, cultural drift, and local adaptation. Our results demonstrated significant regional divergence in frequency and phylogeny among the bat populations in China's northeast (NE), central-east (CE) and southwest (SW) regions. The CE region had higher frequencies than the NE and SW regions. Drivers of RF divergence were estimated in the entire range and just the CE/NE region (since these two regions form a clade). In both cases, RF divergence was not correlated with mtDNA or nDNA genetic distance, but was significantly correlated with geographic distance and mean annual temperature, indicating cultural drift and ecological selection pressures are likely important in shaping RF divergence among different regions in China.

  19. Drift reduction with drift control adjuvants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous drift reduction adjuvants and spray deposition aids are available to applicators of crop production and protection chemicals. Performance of many of the newly introduced drift control adjuvants has not been well documented for aerial application. Five new drift control adjuvants were sele...

  20. Drift reduction with drift control adjuvants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous drift reduction adjuvants and spray deposition aids are available to applicators of crop production and protection chemicals. Performance of many of the newly introduced drift control adjuvants has not been well documented for aerial application. Four new drift control adjuvants were sele...

  1. 10 CFR 26.65 - Pre-access drug and alcohol testing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Pre-access drug and alcohol testing. 26.65 Section 26.65 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.65 Pre-access drug and alcohol testing. (a) Purpose. This section contains pre-access...

  2. 10 CFR 26.65 - Pre-access drug and alcohol testing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Pre-access drug and alcohol testing. 26.65 Section 26.65 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.65 Pre-access drug and alcohol testing. (a) Purpose. This section contains pre-access...

  3. 10 CFR 26.65 - Pre-access drug and alcohol testing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Pre-access drug and alcohol testing. 26.65 Section 26.65 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.65 Pre-access drug and alcohol testing. (a) Purpose. This section contains pre-access...

  4. 10 CFR 26.65 - Pre-access drug and alcohol testing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Pre-access drug and alcohol testing. 26.65 Section 26.65 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.65 Pre-access drug and alcohol testing. (a) Purpose. This section contains pre-access...

  5. 10 CFR 26.65 - Pre-access drug and alcohol testing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Pre-access drug and alcohol testing. 26.65 Section 26.65 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Granting and Maintaining Authorization § 26.65 Pre-access drug and alcohol testing. (a) Purpose. This section contains pre-access...

  6. Prospective Durability Testing of a Vascular Access Phantom

    DTIC Science & Technology

    2010-09-01

    ultrasound guidance when obtaining central venous access.19,20 The increasing use of ultrasound guidance for vascular access has created an educational...with difficult intravenous access. Ann Emerg Med. 2005;46:456-61. 7. Gallieni M, Cozzolino M. Uncomplicated central vein catheterization of high risk...al. Randomized, controlled clinical trial of point-of-care limited ultrasonography assistance of central venous cannulation: The third sonography

  7. Effects of selection and drift on G matrix evolution in a heterogeneous environment: a multivariate Qst-Fst Test with the freshwater snail Galba truncatula.

    PubMed

    Chapuis, Elodie; Martin, Guillaume; Goudet, Jérôme

    2008-12-01

    Unraveling the effect of selection vs. drift on the evolution of quantitative traits is commonly achieved by one of two methods. Either one contrasts population differentiation estimates for genetic markers and quantitative traits (the Q(st)-F(st) contrast) or multivariate methods are used to study the covariance between sets of traits. In particular, many studies have focused on the genetic variance-covariance matrix (the G matrix). However, both drift and selection can cause changes in G. To understand their joint effects, we recently combined the two methods into a single test (accompanying article by Martin et al.), which we apply here to a network of 16 natural populations of the freshwater snail Galba truncatula. Using this new neutrality test, extended to hierarchical population structures, we studied the multivariate equivalent of the Q(st)-F(st) contrast for several life-history traits of G. truncatula. We found strong evidence of selection acting on multivariate phenotypes. Selection was homogeneous among populations within each habitat and heterogeneous between habitats. We found that the G matrices were relatively stable within each habitat, with proportionality between the among-populations (D) and the within-populations (G) covariance matrices. The effect of habitat heterogeneity is to break this proportionality because of selection for habitat-dependent optima. Individual-based simulations mimicking our empirical system confirmed that these patterns are expected under the selective regime inferred. We show that homogenizing selection can mimic some effect of drift on the G matrix (G and D almost proportional), but that incorporating information from molecular markers (multivariate Q(st)-F(st)) allows disentangling the two effects.

  8. 46 CFR 4.06-15 - Accessibility of chemical testing devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Accessibility of chemical testing devices. 4.06-15... MARINE CASUALTIES AND INVESTIGATIONS Mandatory Chemical Testing Following Serious Marine Incidents Involving Vessels in Commercial Service § 4.06-15 Accessibility of chemical testing devices. (a)...

  9. 46 CFR 4.06-15 - Accessibility of chemical testing devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Accessibility of chemical testing devices. 4.06-15... MARINE CASUALTIES AND INVESTIGATIONS Mandatory Chemical Testing Following Serious Marine Incidents Involving Vessels in Commercial Service § 4.06-15 Accessibility of chemical testing devices. (a)...

  10. 46 CFR 4.06-15 - Accessibility of chemical testing devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Accessibility of chemical testing devices. 4.06-15... MARINE CASUALTIES AND INVESTIGATIONS Mandatory Chemical Testing Following Serious Marine Incidents Involving Vessels in Commercial Service § 4.06-15 Accessibility of chemical testing devices. (a)...

  11. 46 CFR 4.06-15 - Accessibility of chemical testing devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Accessibility of chemical testing devices. 4.06-15... MARINE CASUALTIES AND INVESTIGATIONS Mandatory Chemical Testing Following Serious Marine Incidents Involving Vessels in Commercial Service § 4.06-15 Accessibility of chemical testing devices. (a)...

  12. 46 CFR 4.06-15 - Accessibility of chemical testing devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Accessibility of chemical testing devices. 4.06-15... MARINE CASUALTIES AND INVESTIGATIONS Mandatory Chemical Testing Following Serious Marine Incidents Involving Vessels in Commercial Service § 4.06-15 Accessibility of chemical testing devices. (a)...

  13. An experimental test and models of drift and dispersal processes of pallid sturgeon (Scaphirhynchus albus) free embryos in the Missouri River

    USGS Publications Warehouse

    Braaten, P.J.; Fuller, D.B.; Lott, R.D.; Ruggles, M.P.; Brandt, T.F.; Legare, R.G.; Holm, R.J.

    2012-01-01

    Free embryos of wild pallid sturgeon Scaphirhynchus albus were released in the Missouri River and captured at downstream sites through a 180-km reach of the river to examine ontogenetic drift and dispersal processes. Free embryos drifted primarily in the fastest portion of the river channel, and initial drift velocities for all age groups (mean = 0.66–0.70 m s−1) were only slightly slower than mean water column velocity (0.72 m s−1). During the multi-day long-distance drift period, drift velocities of all age groups declined an average of 9.7% day−1. Younger free embryos remained in the drift upon termination of the study; whereas, older age groups transitioned from drifting to settling during the study. Models based on growth of free embryos, drift behavior, size-related variations in drift rates, and channel hydraulic characteristics were developed to estimate cumulative distance drifted during ontogenetic development through a range of simulated water temperatures and velocity conditions. Those models indicated that the average free embryo would be expected to drift several hundred km during ontogenetic development. Empirical data and model results highlight the long-duration, long-distance drift and dispersal processes for pallid sturgeon early life stages. In addition, results provide a likely mechanism for lack of pallid sturgeon recruitment in fragmented river reaches where dams and reservoirs reduce the length of free-flowing river available for pallid sturgeon free embryos during ontogenetic development.

  14. An Everting Ureteral Access Sheath: Concepts and In Vitro Testing

    NASA Astrophysics Data System (ADS)

    Lee, Keith L.; Stoller, Marshall L.

    2007-04-01

    Ureteral access sheaths have been a recent innovation in facilitating ureteral stone surgery. Once properly placed, access sheaths allow the movement of ureteroscopes and other instruments through the ureter with minimal injury to the urothelium. However, there are shortcomings of the current device designs. Initial sheath placement requires significant force, and shear stress can injure the ureter. In addition, inadvertent advancement of the outer sheath without the inner introducer stylet can tear and avulse the ureter. A novel eversion design incorporating a lubricous film provides marked improvement over current access sheaths. In bench top and animal models, the eversion shealths require less force during advancement, cause less injury to the urothelial tissue, and have a lower potential of introducing extraneous materials (e.g., microbes) into a simulated urinary tract. While, the everting design provides important advantages over traditional non-everting designs, further preclinical and clinical trials are required.

  15. Accessibility

    EPA Pesticide Factsheets

    Federal laws, including Section 508 of the Rehabilitation Act, mandate that people with disabilities have access to the same information that someone without a disability would have. 508 standards cover electronic and information technology (EIT) products.

  16. Impact of genetic drift on developing access and benefit sharing guidelines under the Nagoya Protocol: The case of Meishan pigs imported into the US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Convention on Biological Diversity developed the Nagoya Protocol (NP) on access and benefit sharing (ABS) for international exchange of genetic resources across life forms. Concerns are NP will be cumbersome, stifle research, and not accommodate diverse life forms, such as livestock. NP was deve...

  17. Modified Access through Interpretation: A Third Alternative to Truth-in-Testing.

    ERIC Educational Resources Information Center

    Bradley, Richard W.; Snowman, Jack

    1981-01-01

    Presents an alternative between open access to test results as recommended by consumer groups and test security as practiced by test producers. The alternative suggested places counselors directly in the center as interpreters who can satisfy client needs for increased feedback while maintaining test integrity. (Author)

  18. Effect of Adjusting Pseudo-Guessing Parameter Estimates on Test Scaling When Item Parameter Drift Is Present

    ERIC Educational Resources Information Center

    Han, Kyung T.; Wells, Craig S.; Hambleton, Ronald K.

    2015-01-01

    In item response theory test scaling/equating with the three-parameter model, the scaling coefficients A and B have no impact on the c-parameter estimates of the test items since the cparameter estimates are not adjusted in the scaling/equating procedure. The main research question in this study concerned how serious the consequences would be if…

  19. Dike/Drift Interactions

    SciTech Connect

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  20. Thermo-hydro-chemical Predictive analysis for the drift-scalepredictive heater test, version 1.0. Milestone Report SPY289M4

    SciTech Connect

    Sonnenthal, Eric L.; Spycher, Nicolas; Apps, John; Simmons, Ardyth

    1998-06-30

    This report presents a predictive analysis of the geochemical and isotopic alteration of minerals, fluid, and gas accompanying the underground Drift-Scale Heater Test (DST) begun in December 1997. The aim of this analysis is to incorporate the important geochemical and physical phenomena in a numerical model, using and assessing the current information on pore-water chemistry, mineralogy, thermodynamic and kinetic data, and heater test conditions. This work represents an initial effort to understand the system behavior, and the results should not be used by YMP researchers to provide quantitative estimates of the processes investigated. The DST will operate over a period of eight years; as data are collected the models and understanding of the system will undergo refinement and reevaluation. In overall terms, the object is to provide a better understanding of the coupled thermo-hydrological-chemical (THC) system that could be applied with a higher level of confidence to constrain the behavior of the proposed repository for a period of ten thousand years or more.

  1. Coupled thermal-hydrological-mechanical analyses of the YuccaMountain Drift Scale Test - Comparison of field measurements topredictions of four different numerical models

    SciTech Connect

    Rutqvist, J.; Barr, D.; Datta, R.; Gens, A.; Millard, A.; Olivella, S.; Tsang, C.-F.; Tsang, Y.

    2004-08-30

    The Yucca Mountain Drift Scale Test (DST) is a multiyear, large-scale underground heater test designed to study coupled thermal-hydrological-mechanical-chemical behavior in unsaturated fractured and welded tuff. As part of the international cooperative code-comparison project DECOVALEX, four research teams used four different numerical models to simulate and predict coupled thermal-hydrological-mechanical (THM) processes at the DST. The simulated processes included above-boiling temperature changes, liquid and vapor water movements, rock-mass stress and displacement, and THM-induced changes in fracture permeability. Model predictions were evaluated by comparison to measurements of temperature, water saturation,displacement, and air permeability. The generally good agreement between simulated and measured THM data shows that adopted continuum model approaches are adequate for simulating relevant coupled THM processes at the DST. Moreover, TM-induced rock-mass deformations were reasonably well predicted using elastic models, although some individual displacements appeared to be better captured using an elasto-plastic model. It is concluded that fracture closure/opening caused by change in normal stress across fractures is the dominant mechanism for TM-induced changes in intrinsic fracture permeability at the DST, whereas fracture shear dilation appears to be less significant. This indicates that TM-induced changes in intrinsic permeability at the DST, which are within one order of magnitude, tend to be reversible.

  2. Free Drifting Buoys

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Information was exchanged between people directly involved with the development, use, and/or potential use of free drifting buoys. Tracking systems and techniques, where methods and accuracy of optical, radio, radar, satellite, and sonic tracking of free-drifting buoys were discussed. Deployment and retrieval covering methods currently used or planned in the deployment and retrieval of free-drifting buoys from boats, ships, helicopters, fixed platforms, and fixed-wing aircraft were reported. Simulation, sensors, and data emphasizing the status of water circulation modeling, and sensors useful on free-drifting buoys, and data display and analysis were described.

  3. Repository Drift Backfilling Demonstrator

    SciTech Connect

    Londe, I.; Dubois, J.Ph.; Bauer, C.

    2008-07-01

    The 'Backfilling Demonstrator' is one of the technological demonstrators developed by ANDRA in the framework of the feasibility studies for a geological repository for high-level long-lived (HL-LL waste) within a clay formation. The demonstrator concerns the standard and supporting backfills as defined in Andra's 2005 design. The standard backfill is intended to fill up almost all drifts of the underground repository in order to limit any deformation of the rock after the degradation of the drift lining. The supporting backfill only concerns a small portion of the volume to be backfilled in order to counter the swelling pressure of the swelling clay contained in the sealing structures. The first objective of the demonstrator was to show the possibility of manufacturing a satisfactory backfill, in spite of the exiguity of the underground structures, and of reusing as much as possible the argillite muck. For the purpose of this experiment, the argillite muck was collected on Andra's work-site for the implementation of an underground research laboratory. Still ongoing, the second objective is to follow up the long-term evolution of the backfill. Approximately 200 m{sup 3} of compacted backfill material have been gathered in a large concrete tube simulating a repository drift. The standard backfill was manufactured exclusively with argillite. The supporting backfill was made by forming a mixture of argillite and sand. Operations were carried out mostly at Richwiller, close to Mulhouse, France. The objectives of the demonstrator were met: an application method was tested and proven satisfactory. The resulting dry densities are relatively high, although the moduli of deformation do not always reach the set goal. The selected objective for the demonstrator was a dry density corresponding to a relatively high compaction level (95% of the standard Proctor optimum [SPO]), for both pure argillite and the argillite-sand mixture. The plate-percussion compaction technique was

  4. Field investigation of the drift shadow

    SciTech Connect

    Su, Grace W.; Kneafsey, Timothy J.; Ghezzehei, Teamrat A.; Marshall, Brian D.; Cook, Paul J.

    2005-09-08

    A drift shadow is an area immediately beneath an undergroundvoidthat, in theory, will be relatively drier than the surrounding rockmass. Numerical and analytical models of water flow through unsaturatedrock predict the existence of a drift shadow, but field tests confirmingits existence have yet to be performed. Proving the existence of driftshadows and understanding their hydrologic and transport characteristicscould provide a better understanding of how contaminants move in thesubsurface if released from waste emplacement drifts such as the proposednuclear waste repository at Yucca Mountain, Nevada. We describe the fieldprogram that will be used to investigate the existence of a drift shadowand the corresponding hydrological process at the Hazel-Atlas silica-sandmine located at the Black Diamond Mines Regional Preserve in Antioch,California. The location and configuration of this mine makes it anexcellent site to observe and measure drift shadow characteristics. Themine is located in a porous sandstone unit of the Domengine Formation, anapproximately 230 meter thick series of interbedded Eocene-age shales,coals, and massive-bedded sandstones. The mining method used at the minerequired the development of two parallel drifts, one above the other,driven along the strike of the mined sandstone stratum. Thisconfiguration provides the opportunity to introduce water into the rockmass in the upper drift and to observe and measure its flow around theunderlying drift. The passive and active hydrologic tests to be performedare described. In the passive method, cores will be obtained in a radialpattern around a drift and will be sectioned and analyzed for in-situwater content and chemical constituents. With the active hydrologic test,water will be introduced into the upper drift of the two parallel driftsand the flow of the water will be tracked as it passes near the bottomdrift. Tensiometers, electrical resistance probes, neutron probes, andground penetrating radar may be

  5. FIELD INVESTIGATIONS OF THE DRIFT SHADOW

    SciTech Connect

    G. W. Su, T. J. Kneafsey, T. A. Ghezzehei, B. D. Marshall, and P. J. Cook

    2006-01-15

    The ''Drift Shadow'' is defined as the relatively drier region that forms below subsurface cavities or drifts in unsaturated rock. Its existence has been predicted through analytical and numerical models of unsaturated flow. However, these theoretical predictions have not been demonstrated empirically to date. In this project they plan to test the drift shadow concept through field investigations and compare our observations to simulations. Based on modeling studies they have an identified suitable site to perform the study at an inactive mine in a sandstone formation. Pretest modeling studies and preliminary characterization of the site are being used to develop the field scale tests.

  6. Abstraction of Drift Seepage

    SciTech Connect

    J.T. Birkholzer

    2004-11-01

    This model report documents the abstraction of drift seepage, conducted to provide seepage-relevant parameters and their probability distributions for use in Total System Performance Assessment for License Application (TSPA-LA). Drift seepage refers to the flow of liquid water into waste emplacement drifts. Water that seeps into drifts may contact waste packages and potentially mobilize radionuclides, and may result in advective transport of radionuclides through breached waste packages [''Risk Information to Support Prioritization of Performance Assessment Models'' (BSC 2003 [DIRS 168796], Section 3.3.2)]. The unsaturated rock layers overlying and hosting the repository form a natural barrier that reduces the amount of water entering emplacement drifts by natural subsurface processes. For example, drift seepage is limited by the capillary barrier forming at the drift crown, which decreases or even eliminates water flow from the unsaturated fractured rock into the drift. During the first few hundred years after waste emplacement, when above-boiling rock temperatures will develop as a result of heat generated by the decay of the radioactive waste, vaporization of percolation water is an additional factor limiting seepage. Estimating the effectiveness of these natural barrier capabilities and predicting the amount of seepage into drifts is an important aspect of assessing the performance of the repository. The TSPA-LA therefore includes a seepage component that calculates the amount of seepage into drifts [''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504], Section 6.3.3.1)]. The TSPA-LA calculation is performed with a probabilistic approach that accounts for the spatial and temporal variability and inherent uncertainty of seepage-relevant properties and processes. Results are used for subsequent TSPA-LA components that may handle, for example, waste package corrosion or radionuclide transport.

  7. Analysis of Thermally Induced Changes in Fractured Rock Permeability during Eight Years of Heating and Cooling at the Yucca Mountain Drift Scale Test

    SciTech Connect

    Rutqvist, J.; Freifeld, B.; Min, K.-B.; Elsworth, D.; Tsang, Y.

    2008-06-01

    We analyzed a data set of thermally induced changes in fractured rock permeability during a four-year heating (up to 200 C) and subsequent four-year cooling of a large volume, partially saturated and highly fractured volcanic tuff at the Yucca Mountain Drift Scale Test, in Nevada, USA. Permeability estimates were derived from about 700 pneumatic (air-injection) tests, taken periodically at 44 packed-off borehole intervals during the heating and cooling cycle from November 1997 through November 2005. We analyzed air-permeability data by numerical modeling of thermally induced stress and moisture movements and their impact on air permeability within the highly fractured rock. Our analysis shows that changes in air permeability during the initial four-year heating period, which were limited to about one order of magnitude, were caused by the combined effects of thermal-mechanically-induced stress on fracture aperture and thermal-hydrologically-induced changes in fracture moisture content. At the end of the subsequent four-year cooling period, air-permeability decreases (to as low as 0.2 of initial) and increases (to as high as 1.8 of initial) were observed. By comparison to the calculated thermo-hydro-elastic model results, we identified these remaining increases or decreases in air permeability as irreversible changes in intrinsic fracture permeability, consistent with either inelastic fracture shear dilation (where permeability increased) or inelastic fracture surface asperity shortening (where permeability decreased). In this paper, we discuss the possibility that such fracture asperity shortening and associated decrease in fracture permeability might be enhanced by dissolution of highly stressed surface asperities over years of elevated stress and temperature.

  8. The Electron Drift Instrument for Cluster

    NASA Technical Reports Server (NTRS)

    Paschmann, G.; Melzner, F.; Frenzel, R.; Vaith, H.; Parigger, P.; Pagel, U.; Bauer, O. H.; Haerendel, G.; Baumjohann, W.; Scopke, N.

    1997-01-01

    The Electron Drift Instrument (EDI) measures the drift of a weak beam of test electrons that, when emitted in certain directions, return to the spacecraft after one or more gyrations. This drift is related to the electric field and the gradient in the magnetic field, and these quantities can, by use of different electron energies, be determined separately. As a by-product, the magnetic field strength is also measured. The present paper describes the scientific objectives, the experimental method, and the technical realization of the various elements of the instrument.

  9. HIV risk behavior and access to services: what predicts HIV testing among heterosexually active homeless men?

    PubMed

    Wenzel, Suzanne L; Rhoades, Harmony; Tucker, Joan S; Golinelli, Daniela; Kennedy, David P; Zhou, Annie; Ewing, Brett

    2012-06-01

    HIV is a serious epidemic among homeless persons, where rates of infection are estimated to be three times higher than in the general population. HIV testing is an effective tool for reducing HIV transmission and for combating poor HIV/AIDS health outcomes that disproportionately affect homeless persons, however, little is known about the HIV testing behavior of homeless men. This study examined the association between individual (HIV risk) and structural (service access) factors and past year HIV testing. Participants were a representative sample of 305 heterosexually active homeless men interviewed from meal programs in the Skid Row region of Los Angeles. Logistic regression examined the association between past year HIV testing and demographic characteristics, HIV risk behavior, and access to other services in the Skid Row area in the past 30 days. Despite high rates of past year HIV testing, study participants also reported high rates of HIV risk behavior, suggesting there is still significant unmet need for HIV prevention among homeless men. Having recently used medical/dental services in the Skid Row area (OR: 1.91; CI: 1.09, 3.35), and being a military veteran (OR: 2.10; CI: 1.01-4.37) were significantly associated with HIV testing service utilization. HIV testing was not associated with HIV risk behavior, but rather with access to services and veteran status, the latter of which prior research has linked to increased service access. We suggest that programs encouraging general medical service access may be important for disseminating HIV testing services to this high-risk, vulnerable population.

  10. Lithium drifted germanium system

    NASA Technical Reports Server (NTRS)

    Fjarlie, E. J.

    1969-01-01

    General characteristics of the lithium-drifted germanium photodiode-Dewar-preamplifier system and particular operating instructions for the device are given. Information is included on solving operational problems.

  11. Continental drift before 1900.

    PubMed

    Rupke, N A

    1970-07-25

    The idea that Francis Bacon and other seventeenth and eighteenth century thinkers first conceived the notion of continental drift does not stand up to close scrutiny. The few authors who expressed the idea viewed the process as a catastrophic event.

  12. Case Report: Direct Access Genetic Testing and A False-Positive Result For Long QT Syndrome.

    PubMed

    Predham, Sarah; Hamilton, Sara; Elliott, Alison M; T Gibson, William

    2016-02-01

    We report the case of a woman who pursued direct access genetic testing and then presented with concerns regarding a positive test result for Long-QT syndrome. Although the result ultimately proved to be a false positive, this case illustrates that costs associated with follow-up of direct access genetic testing results can be non-trivial for both the patient and for health care systems. Here we raise policy questions regarding the appropriate distribution of these costs. We also discuss the possibility that, when confronted by a direct access genetic test result that reports high risk for one or more actionable diseases, a family physician might feel compelled to act out of a desire to avoid liability, even when information regarding the accuracy and validity of the testing were not easily accessible. This case outlines lessons that can easily be translated into clinical practice, not only by genetic counselors, but also by family physicians, medical specialists and members of the public.

  13. Early antiretroviral therapy initiation: access and equity of viral load testing for HIV treatment monitoring.

    PubMed

    Peter, Trevor; Ellenberger, Dennis; Kim, Andrea A; Boeras, Debrah; Messele, Tsehaynesh; Roberts, Teri; Stevens, Wendy; Jani, Ilesh; Abimiku, Alash'le; Ford, Nathan; Katz, Zachary; Nkengasong, John N

    2017-01-01

    Scaling up access to HIV viral load testing for individuals undergoing antiretroviral therapy in low-resource settings is a global health priority, as emphasised by research showing the benefits of suppressed viral load for the individual and the whole population. Historically, large-scale diagnostic test implementation has been slow and incomplete because of service delivery and other challenges. Building on lessons from the past, in this Personal View we propose a new framework to accelerate viral load scale-up and ensure equitable access to this essential test. The framework includes the following steps: (1) ensuring adequate financial investment in scaling up this test; (2) achieving pricing agreements and consolidating procurement to lower prices of the test; (3) strengthening functional tiered laboratory networks and systems to expand access to reliable, high-quality testing across countries; (4) strengthening national leadership, with prioritisation of laboratory services; and (5) demand creation and uptake of test results by clinicians, nurses, and patients, which will be vital in ensuring viral load tests are appropriately used to improve the quality of care. The use of dried blood spots to stabilise and ship samples from clinics to laboratories, and the use of point-of-care diagnostic tests, will also be important for ensuring access, especially in settings with reduced laboratory capacity. For countries that have just started to scale up viral load testing, lessons can be learnt from countries such as Botswana, Brazil, South Africa, and Thailand, which have already established viral load programmes. This framework might be useful for guiding the implementation of viral load with the aim of achieving the new global HIV 90-90-90 goals by 2020.

  14. Man-computer Inactive Data Access System (McIDAS). [design, development, fabrication, and testing

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A technical description is given of the effort to design, develop, fabricate, and test the two dimensional data processing system, McIDAS. The system has three basic sections: an access and data archive section, a control section, and a display section. Areas reported include hardware, system software, and applications software.

  15. What Constrains the Accuracy of Metacomprehension Judgments? Testing the Transfer-Appropriate-Monitoring and Accessibility Hypotheses

    ERIC Educational Resources Information Center

    Dunlosky, J.; Rawson, K.A.; Middleton, E.L.

    2005-01-01

    We evaluated two hypotheses-transfer appropriate monitoring (TAM) and the accessibility hypothesis-that explain why the accuracy of metacomprehension judgments is commonly low. In 2 experiments, participants read six expository texts, made global judgments about how well they would perform on a test over each text, and made term-specific judgments…

  16. The Changing Faces of Corruption in Georgian Higher Education: Access through Times and Tests

    ERIC Educational Resources Information Center

    Orkodashvili, Mariam

    2012-01-01

    This article presents a comparative-historical analysis of access to higher education in Georgia. It describes the workings of corrupt channels during the Soviet and early post-Soviet periods and the role of standardized tests in fighting corruption in higher education admission processes after introduction of the Unified National Entrance…

  17. Environmental Technology Verification Report: Pesticide spray drift reduction technologies--Evaluation of the verification protocol for low and high speed wind tunnel testing

    EPA Science Inventory

    Pesticide spray drift is defined as the movement of spray droplets through the air at the time of application or soon thereafter from the target site to any non- or off-target site, excluding pesticide movements by erosion, migration, volatility, or windblown soil particles after...

  18. Search Hanford Accessible Reports Electronically system test plan and documentation: Revision 1

    SciTech Connect

    White, E.L.

    1994-12-07

    The purpose of this document is to describe the following items: the approach, resources, and sequence of the testing activities; identifies the components and features to be tested; the personnel responsible for testing; the risks associated with this plan; and test cases and procedures. This document contains all test documentation for the SHARE system. The Search Hanford Accessible Reports Electronically (SHARE) testing process is based upon WHC-CM-3-10, Software Practices, Section SP-3.3 REV 0, and Appendix J REV 0. These procedures and guidelines are based on IEEE Standard 829-1983. The planning in this document was further influenced through guidance in IEEE Standard 1012-1986. This document contains the System, Acceptance, Integration and Component Test Plans, Designs, Procedures, and Cases for SHARE. The Test Cases and procedures have been attached to the document.

  19. The generalized drift flux approach: Identification of the void-drift closure law

    NASA Technical Reports Server (NTRS)

    Boure, J. A.

    1989-01-01

    The main characteristics and the potential advantages of generalized drift flux models are presented. In particular it is stressed that the issue on the propagation properties and on the mathematical nature (hyperbolic or not) of the model and the problem of closure are easier to tackle than in two fluid models. The problem of identifying the differential void-drift closure law inherent to generalized drift flux models is then addressed. Such a void-drift closure, based on wave properties, is proposed for bubbly flows. It involves a drift relaxation time which is of the order of 0.25 s. It is observed that, although wave properties provide essential closure validity tests, they do not represent an easily usable source of quantitative information on the closure laws.

  20. Shear wall ultimate drift limits

    SciTech Connect

    Duffey, T.A.; Goldman, A.; Farrar, C.R.

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  1. Drift Degradation Analysis

    SciTech Connect

    D. Kicker

    2004-09-16

    Degradation of underground openings as a function of time is a natural and expected occurrence for any subsurface excavation. Over time, changes occur to both the stress condition and the strength of the rock mass due to several interacting factors. Once the factors contributing to degradation are characterized, the effects of drift degradation can typically be mitigated through appropriate design and maintenance of the ground support system. However, for the emplacement drifts of the geologic repository at Yucca Mountain, it is necessary to characterize drift degradation over a 10,000-year period, which is well beyond the functional period of the ground support system. This document provides an analysis of the amount of drift degradation anticipated in repository emplacement drifts for discrete events and time increments extending throughout the 10,000-year regulatory period for postclosure performance. This revision of the drift degradation analysis was developed to support the license application and fulfill specific agreement items between the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE). The earlier versions of ''Drift Degradation Analysis'' (BSC 2001 [DIRS 156304]) relied primarily on the DRKBA numerical code, which provides for a probabilistic key-block assessment based on realistic fracture patterns determined from field mapping in the Exploratory Studies Facility (ESF) at Yucca Mountain. A key block is defined as a critical block in the surrounding rock mass of an excavation, which is removable and oriented in an unsafe manner such that it is likely to move into an opening unless support is provided. However, the use of the DRKBA code to determine potential rockfall data at the repository horizon during the postclosure period has several limitations: (1) The DRKBA code cannot explicitly apply dynamic loads due to seismic ground motion. (2) The DRKBA code cannot explicitly apply loads due to thermal stress. (3) The DRKBA

  2. SAA drift: Experimental results

    NASA Astrophysics Data System (ADS)

    Grigoryan, O. R.; Romashova, V. V.; Petrov, A. N.

    According to the paleomagnetic analysis there are variations of Earth’s magnetic field connected with magnetic moment changing. These variations affect on the South Atlantic Anomaly (SAA) location. Indeed different observations approved the existence of the SAA westward drift rate (0.1 1.0 deg/year) and northward drift rate (approximately 0.1 deg/year). In this work, we present the analysis of experimental results obtained in Scobeltsyn Institute of Nuclear Physics, Moscow State University (SINP MSU) onboard different Earth’s artificial satellites (1972 2003). The fluxes of protons with energy >50 MeV, gamma quanta with energy >500 keV and neutrons with energy 0.1 1.0 MeV in the SAA region have been analyzed. The mentioned above experimental data were obtained onboard the orbital stations Salut-6 (1979), MIR (1991, 1998) and ISS (2003) by the similar experimental equipment. The comparison of the data obtained during these two decades of investigations confirms the fact that the SAA drifts westward. Moreover the analysis of fluxes of electrons with energy about hundreds keV (Cosmos-484 (1972) and Active (Interkosmos-24, 1991) satellites) verified not only the SAA westward drift but northward drift also.

  3. Universal access to HIV treatment versus universal 'test and treat': transmission, drug resistance & treatment costs.

    PubMed

    Wagner, Bradley G; Blower, Sally

    2012-01-01

    In South Africa (SA) universal access to treatment for HIV-infected individuals in need has yet to be achieved. Currently ~1 million receive treatment, but an additional 1.6 million are in need. It is being debated whether to use a universal 'test and treat' (T&T) strategy to try to eliminate HIV in SA; treatment reduces infectivity and hence transmission. Under a T&T strategy all HIV-infected individuals would receive treatment whether in need or not. This would require treating 5 million individuals almost immediately and providing treatment for several decades. We use a validated mathematical model to predict impact and costs of: (i) a universal T&T strategy and (ii) achieving universal access to treatment. Using modeling the WHO has predicted a universal T&T strategy in SA would eliminate HIV within a decade, and (after 40 years) cost ~$10 billion less than achieving universal access. In contrast, we predict a universal T&T strategy in SA could eliminate HIV, but take 40 years and cost ~$12 billion more than achieving universal access. We determine the difference in predictions is because the WHO has under-estimated survival time on treatment and ignored the risk of resistance. We predict, after 20 years, ~2 million individuals would need second-line regimens if a universal T&T strategy is implemented versus ~1.5 million if universal access is achieved. Costs need to be realistically estimated and multiple evaluation criteria used to compare 'treatment as prevention' with other prevention strategies. Before implementing a universal T&T strategy, which may not be sustainable, we recommend striving to achieve universal access to treatment as quickly as possible. We predict achieving universal access to treatment would be a very effective 'treatment as prevention' approach and bring the HIV epidemic in SA close to elimination, preventing ~4 million infections after 20 years and ~11 million after 40 years.

  4. Changes in constructed Brassica communities treated with glyphosate drift.

    PubMed

    Watrud, Lidia S; King, George; Londo, Jason P; Colasanti, Ricardo; Smith, Bonnie M; Waschmann, Ronald S; Lee, E Henry

    2011-03-01

    We constructed a mixed-species community designed to simulate roadside and field edge plant communities and exposed it to glyphosate drift in order to test three hypotheses: (1) higher fitness in transgenic Brassica carrying the CP4 EPSPS transgene that confers resistance to glyphosate will result in significant changes in the plant community relative to control communities; (2) given repeated years of glyphosate drift selective pressure, the increased fitness of the transgenic Brassica with CP4 EPSPS will contribute to an increase in the proportion of transgenic progeny produced in plant communities; and (3) the increased fitness of Brassica carrying the CP4 EPSPS transgene will contribute to decreased levels of mycorrhizal infection and biomass in a host species (Trifolium incarnatum). Due to regulatory constraints that prevented the use of outdoor plots for our studies, in 2005 we established multispecies communities in five large cylindrical outdoor sunlit mesocosms (plastic greenhouses) designed for pollen confinement. Three of the community members were sexually compatible Brassica spp.: transgenic glyphosate-resistant canola (B. napus) cultivar (cv.) RaideRR, glyphosate-sensitive non-transgenic B. napus cv. Sponsor, and a weedy B. rapa (GRIN Accession 21735). Additional plant community members were the broadly distributed annual weeds Digitaria sanguinalis, Panicum capillare, and Lapsana communis. Once annually in 2006 and 2007, two mesocosms were sprayed with glyphosate at 10% of the field application rate to simulate glyphosate drift as a selective pressure. After two years, changes were observed in community composition, plant density, and biomass in both control and treatment mesocosms. In control mesocosms, the weed D. sanguinalis (crabgrass) began to dominate. In glyphosate drift-treated mesocosms, Brassica remained the dominant genus and the incidence of the CP4 EPSPS transgene increased in the community. Shoot biomass and mycorrhizal infection in

  5. HIV testing practices of South African township MSM in the era of expanded access to ART

    PubMed Central

    Sandfort, Theo G. M.; Knox, Justin; Collier, Kate L.; Lane, Tim; Reddy, Vasu

    2014-01-01

    While men who have sex with men (MSM) in Africa are at high risk for HIV infection, few of those already infected know their status. Effectively promoting frequent HIV testing—of increasing importance with the expanding accessibility of antiretroviral treatment—requires an understanding of the testing practices in this population. To understand men’s HIV testing practices, including their behavior, experiences, and perceptions, we conducted in-depth interviews with 81 black South African MSM (ages 20–39), purposively recruited from four townships. Many men in the sample had tested for HIV. While ever having tested seemed to facilitate repeat testing, men still expressed a high level of discomfort with testing. It was common to test after having engaged in risky behavior, thus increasing anxiety about testing that was already present. Fear that they might test HIV positive caused some men to avoid testing until they were clearly sick, and others to avoid testing completely. HIV testing may increase in this population if it becomes a routine practice, instead of being driven by anxiety-inducing incidents. Mobilization through social support might facilitate frequent testing while education about current treatment options is needed. PMID:25103866

  6. High resolution drift chambers

    SciTech Connect

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 ..mu..m resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs.

  7. A RAM architecture for concurrent access and on-chip testing

    NASA Technical Reports Server (NTRS)

    Liu, Jyh-Charn; Shin, Kang G.

    1991-01-01

    A novel RAM architecture supporting concurrent memory access and on-chip testing (CMAT) is proposed. A large-capacity memory chip is decomposed into test neighborhoods (TNDs), each of which is tested independently. When there are data stored in a TND, the data are saved into a buffer before testing the TND, and the TND's contents are restored using buffered data after testing the TND. If an external request is not made to the TND, the request can be directed to the addressed memory cells. Otherwise, the buffered data can be loaded back into the TND, or the request is detoured to a corresponding buffer. By deriving an analytical model, the performance penalty and hardware overhead of the CMAT architecture are shown to be very small.

  8. Dike Propagation Near Drifts

    SciTech Connect

    NA

    2002-03-04

    The purpose of this Analysis and Model Report (AMR) supporting the Site Recommendation/License Application (SR/LA) for the Yucca Mountain Project is the development of elementary analyses of the interactions of a hypothetical dike with a repository drift (i.e., tunnel) and with the drift contents at the potential Yucca Mountain repository. This effort is intended to support the analysis of disruptive events for Total System Performance Assessment (TSPA). This AMR supports the Process Model Report (PMR) on disruptive events (CRWMS M&O 2000a). This purpose is documented in the development plan (DP) ''Coordinate Modeling of Dike Propagation Near Drifts Consequences for TSPA-SR/LA'' (CRWMS M&O 2000b). Evaluation of that Development Plan and the work to be conducted to prepare Interim Change Notice (ICN) 1 of this report, which now includes the design option of ''Open'' drifts, indicated that no revision to that DP was needed. These analyses are intended to provide reasonable bounds for a number of expected effects: (1) Temperature changes to the waste package from exposure to magma; (2) The gas flow available to degrade waste containers during the intrusion; (3) Movement of the waste package as it is displaced by the gas, pyroclasts and magma from the intruding dike (the number of packages damaged); (4) Movement of the backfill (Backfill is treated here as a design option); (5) The nature of the mechanics of the dike/drift interaction. These analyses serve two objectives: to provide preliminary analyses needed to support evaluation of the consequences of an intrusive event and to provide a basis for addressing some of the concerns of the Nuclear Regulatory Commission (NRC) expressed in the Igneous Activity Issue Resolution Status Report.

  9. Test and analysis of a stitched RFI graphite-epoxy panel with a fuel access door

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.; Waters, W. Allen, Jr.

    1994-01-01

    A stitched RFI graphite-epoxy panel with a fuel access door was analyzed using a finite element analysis and loaded to failure in compression. The panel was initially 56-inches long and 36.75-inches wide and the oval access door was 18-inches long and 15-inches wide. The panel was impact damaged with impact energy of 100 ft-lb prior to compressive loading; however, no impact damage was detectable visually or by A-scan. The panel carried a failure load of 695,000 Ib and global failure strain of .00494 in/in. Analysis indicated the panel would fail due to collapse at a load of 688,100 Ib. The test data indicate that the maximum strain in a region near the access door was .0096 in/in and analysis indicates a local surface strain of .010 in/in at the panel's failure load. The panel did not fail through the impact damage, but instead failed through bolt holes for attachment of the access door in a region of high strain.

  10. Proportional drift tubes for large area muon detectors

    NASA Technical Reports Server (NTRS)

    Cho, C.; Higashi, S.; Hiraoka, N.; Maruyama, A.; Okusawa, T.; Sato, T.; Suwada, T.; Takahashi, T.; Umeda, H.

    1985-01-01

    A proportional drift chamber which consists of eight rectangular drift tubes with cross section of 10 cm x 5 cm, a sense wire of 100 micron phi gold-plated tungsten wire and the length of 6 m, was tested using cosmic ray muons. Spatial resolution (rms) is between 0.5 and 1 mm over drift space of 50 mm, depending on incident angle and distance from sense wire.

  11. An Universal Packaging Technique for Low-Drift Implantable Pressure Sensors

    PubMed Central

    Kim, Albert; Powell, Charles. R.; Ziaie, Babak

    2016-01-01

    Monitoring bodily pressures provide valuable diagnostic and prognostic information. In particular, long-term measurement through implantable sensors is highly desirable in situations where percutaneous access can be complicated or dangerous (e.g., intracranial pressure in hydrocephalic patients). In spite of decades of progress in the fabrication of miniature solid-state pressure sensors, sensor drift has so far severely limited their application in implantable systems. In this paper, we report on a universal packaging technique for reducing the sensor drift. The described method isolates the pressure sensor from a major source of drift, i.e., contact with the aqueous surrounding environment, by encasing the sensor in a silicone-filled medical-grade polyurethane balloon. In-vitro soak tests for 100 days using commercial micromachined piezoresistive pressure sensors demonstrate a stable operation with the output remaining within 1.8 cmH2O (1.3 mmHg) of a reference pressure transducer. Under similar test conditions, a non-isolated sensor fluctuates between 10–20 cmH2O (7.4–14.7 mmHg) of the reference, without ever settling to a stable operation regime. Implantation in Ossabow pigs demonstrate the robustness of the package and its in-vivo efficacy in reducing the baseline drift. PMID:26945864

  12. Seeking wider access to HIV testing for adolescents in sub-Saharan Africa.

    PubMed

    Sam-Agudu, Nadia A; Folayan, Morenike O; Ezeanolue, Echezona E

    2016-06-01

    More than 80% of the HIV-infected adolescents live in sub-Saharan Africa. Acquired immune deficiency syndrome (AIDS)-related mortality has increased among adolescents 10-19 y old. The impact is highest in sub-Saharan Africa, where >80% of HIV-infected adolescents live. The World Health Organization has cited inadequate access to HIV testing and counseling (HTC) as a contributing factor to AIDS-related adolescent deaths, most of which occur in sub-Saharan Africa. This review focuses on studies conducted in high adolescent HIV-burden countries targeted by the "All In to End Adolescent AIDS" initiative, and describes barriers to adolescent HTC uptake and coverage. Fear of stigma and family reaction, fear of the impact of a positive diagnosis, perceived risk with respect to sexual exposure, poor attitudes of healthcare providers, and parental consent requirements are identified as major impediments. Most-at-risk adolescents for HIV infection and missed opportunities for testing include, those perinatally infected, those with early sexual debut, high mobility and multiple/older partners, and pregnant and nonpregnant females. Regional analyses show relatively low adolescent testing rates and more restrictive consent requirements for HTC in West and Central Africa as compared to East and southern Africa. Actionable recommendations for widening adolescent access to HTC and therefore timely care include minimizing legal consent barriers, healthcare provider training, parental education and involvement, and expanding testing beyond healthcare facilities.

  13. What explains rare and conspicuous colours in a snail? A test of time-series data against models of drift, migration or selection

    PubMed Central

    Johannesson, K; Butlin, R K

    2017-01-01

    It is intriguing that conspicuous colour morphs of a prey species may be maintained at low frequencies alongside cryptic morphs. Negative frequency-dependent selection by predators using search images (‘apostatic selection') is often suggested without rejecting alternative explanations. Using a maximum likelihood approach we fitted predictions from models of genetic drift, migration, constant selection, heterozygote advantage or negative frequency-dependent selection to time-series data of colour frequencies in isolated populations of a marine snail (Littorina saxatilis), re-established with perturbed colour morph frequencies and followed for >20 generations. Snails of conspicuous colours (white, red, banded) are naturally rare in the study area (usually <10%) but frequencies were manipulated to levels of ~50% (one colour per population) in 8 populations at the start of the experiment in 1992. In 2013, frequencies had declined to ~15–45%. Drift alone could not explain these changes. Migration could not be rejected in any population, but required rates much higher than those recorded. Directional selection was rejected in three populations in favour of balancing selection. Heterozygote advantage and negative frequency-dependent selection could not be distinguished statistically, although overall the results favoured the latter. Populations varied idiosyncratically as mild or variable colour selection (3–11%) interacted with demographic stochasticity, and the overall conclusion was that multiple mechanisms may contribute to maintaining the polymorphisms. PMID:27649616

  14. Diogene pictorial drift chamber

    SciTech Connect

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive).

  15. Impact of Gene Patents and Licensing Practices on Access to Genetic Testing for Hereditary Hemochromatosis

    PubMed Central

    Chandrasekharan, Subhashini; Pitlick, Emily; Heaney, Christopher; Cook-Deegan, Robert

    2010-01-01

    Hereditary hemochromatosis (HH) is an iron metabolism disorder that leads to excess iron buildup, especially in the heart, liver, and pancreas. Mutations in the HFE gene are the single most common cause of HH, which can be treated effectively if diagnosed early. Patents cover the HFE gene, related proteins, screening methods, and testing kits. Most initial testing for HH is biochemical, but HFE DNA testing or genotyping is used to confirm a diagnosis of inherited hemochromatosis. Concerns over patents covering HFE testing emerged in 2002, when scholars argued that exclusive licensing and the patent-enabled sole provider model then in place led to high prices and limited access. Critics of the sole provider model noted that the test was available at multiple laboratories prior to the enforcement of patents. By 2007, however, Bio-Rad, Limited, acquired the key intellectual property and sub-licensed it widely. In part because of broad, non-exclusive licensing, there are now multiple providers and testing technologies, and research continues. This case study illustrates how both changes in intellectual property ownership and evolving clinical utility of HFE genetic testing in the last decade have effected the licensing of patents and availability of genetic testing. PMID:20393306

  16. Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Research Team

    NASA Technical Reports Server (NTRS)

    Kelly, Michael J.

    2013-01-01

    The Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage raft empennage.

  17. Consumer direct access to clinical laboratory testing: what are the critical issues?

    PubMed

    Wilkinson, David S; Pontius, C Anne

    2003-01-01

    Americans are demanding, independent people. In most aspects of our lives, we are used to walking into a store or other place of business with the expectation that the personnel working for the business will make every effort to satisfy our requests quickly and without the need for a third party to intervene or approve the transaction. Hence, the popularity of convenience stores, do-it-yourself stores and kits, and e-commerce. The delivery of health-care services, however, generally does not conform to this model. Before most diagnostic tests or treatments are ordered, patients usually consult a physician. In many cases, prior to tests or treatments being performed, additional consultations are required with insurance plans. But the winds of change, they are a-blowing. More and more, people demand an active role in managing their health care. One emerging trend is direct patient access to clinical laboratory testing (1).

  18. Single wire drift chamber design

    SciTech Connect

    Krider, J.

    1987-03-30

    This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

  19. The genetic drift inventory: a tool for measuring what advanced undergraduates have mastered about genetic drift.

    PubMed

    Price, Rebecca M; Andrews, Tessa C; McElhinny, Teresa L; Mead, Louise S; Abraham, Joel K; Thanukos, Anna; Perez, Kathryn E

    2014-01-01

    Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures upper-division students' understanding of this concept. We used an iterative approach that included extensive interviews and field tests involving 1723 students across five different undergraduate campuses. The GeDI consists of 22 agree-disagree statements that assess four key concepts and six misconceptions. Student scores ranged from 4/22 to 22/22. Statements ranged in mean difficulty from 0.29 to 0.80 and in discrimination from 0.09 to 0.46. The internal consistency, as measured with Cronbach's alpha, ranged from 0.58 to 0.88 across five iterations. Test-retest analysis resulted in a coefficient of stability of 0.82. The true-false format means that the GeDI can test how well students grasp key concepts central to understanding genetic drift, while simultaneously testing for the presence of misconceptions that indicate an incomplete understanding of genetic drift. The insights gained from this testing will, over time, allow us to improve instruction about this key component of evolution.

  20. Toward universal access to HIV counseling and testing and antiretroviral treatment in Ethiopia: looking beyond HIV testing and ART initiation.

    PubMed

    Assefa, Yibeltal; Van Damme, Wim; Mariam, Damen Haile; Kloos, Helmut

    2010-08-01

    Expanding access to HIV counseling and testing (HCT) and antiretroviral treatment (ART) has reduced morbidity and mortality in people living with HIV/AIDS. As a result, many countries are scaling up HIV/AIDS services. In this paper we discuss challenges experienced during the move toward universal access to HCT and ART services in Ethiopia. We reviewed routine reports from the Ministry of Health and implementing partners. We also had interviews, about linkage to and retention in care of patients, with 10 HIV/AIDS program managers, as well as 2 to 7 health care providers and 5 to 15 patients in each of 23 health centers and 32 hospitals in all regions of the country. We found that the number of people tested for HIV increased 10-fold from 435,854 in 2005 to 4,559,954 in 2008. Only 61% of the HIV-positive patients were linked to chronic care immediately after tested for HIV. The number of patients initiated on ART annually increased from 26,021 in 2005 to 53,696 in 2008. Attrition of patients increased from 18% in 2005 to 26% in 2008. Our interviews indicated that fear of stigma, transport cost, feeling healthy and opting for traditional medicines were the main reasons for poor linkage to and retention in care. Lack of nutrition and feeling better were also reasons for poor retention. In conclusion, in spite of the rapid scale-up of HCT and ART services in Ethiopia, linkage and retention were not adequate. Therefore, strategies should be developed and implemented to improve linkage and retention.

  1. P-type silicon drift detectors

    SciTech Connect

    Walton, J.T.; Krieger, B.; Krofcheck, D.; O`Donnell, R.; Odyniec, G.; Partlan, M.D.; Wang, N.W.

    1995-06-01

    Preliminary results on 16 CM{sup 2}, position-sensitive silicon drift detectors, fabricated for the first time on p-type silicon substrates, are presented. The detectors were designed, fabricated, and tested recently at LBL and show interesting properties which make them attractive for use in future physics experiments. A pulse count rate of approximately 8 {times} l0{sup 6} s{sup {minus}1} is demonstrated by the p-type silicon drift detectors. This count rate estimate is derived by measuring simultaneous tracks produced by a laser and photolithographic mask collimator that generates double tracks separated by 50 {mu}m to 1200 {mu}m. A new method of using ion-implanted polysilicon to produce precise valued bias resistors on the silicon drift detectors is also discussed.

  2. Impact of Gene Patents and Licensing Practices on Access to Genetic Testing for Cystic Fibrosis

    PubMed Central

    Chandrasekharan, Subhashini; Heaney, Christopher; James, Tamara; Conover, Chris; Cook-Deegan, Robert

    2010-01-01

    Cystic fibrosis (CF) is one of the most commonly tested autosomal recessive disorders in the US. Clinical CF is associated with mutations in the CFTR gene, of which the most common mutation among Caucasians, ΔF508, was identified in 1989. The University of Michigan, Johns Hopkins University, and the Hospital for Sick Children, where much of the initial research occurred, hold key patents for CF genetic sequences, mutations and methods for detecting them. Several patents including the one that covers detection of the ΔF508 mutation are jointly held by the University of Michigan and the Hospital for Sick Children in Toronto, with Michigan administering patent licensing in the US. The University of Michigan broadly licenses the ΔF508 patent for genetic testing with over 60 providers of genetic testing to date. Genetic testing is now used in newborn screening, diagnosis, and reproductive decisions. Interviews with key researchers and intellectual property managers, a survey of laboratories’ prices for CF genetic testing, a review of literature on CF tests’ cost effectiveness, and a review of the developing market for CF testing provide no evidence that patents have significantly hindered access to genetic tests for CF or prevented financially cost-effective screening. Current licensing practices for cystic fibrosis (CF) genetic testing appear to facilitate both academic research and commercial testing. More than one thousand different CFTR mutations have been identified, and research continues to determine their clinical significance. Patents have been nonexclusively licensed for diagnostic use, and have been variably licensed for gene transfer and other therapeutic applications. The Cystic Fibrosis Foundation has been engaged in licensing decisions, making CF a model of collaborative and cooperative patenting and licensing practice. PMID:20393308

  3. Multiple user access and testing for PreNotiS: a fast mobile event reporting solution

    NASA Astrophysics Data System (ADS)

    Chan, Michael; Kumar, Abhinav; Akopian, David; Agaian, Sos S.

    2011-06-01

    The PreNotiS (preventive notification system) was proposed to address the current lack in consumer prevention and disaster informatics systems. The underscore of this letter is to propose PreNotiS as a provision of trusted proxies of information sourcing to be integral to the disaster informatics framework. To promote loose coupling among subsystems, PreNotiS has evolved into a model-view-controller (MVC) architecture via object-oriented incremental prototyping. The MVC specifies how all subsystems and how they interact with each other. A testing framework is also proposed for the PreNotiS to verify multiple concurrent user access which might be observable during disasters. The framework relies on conceptually similar self-test modules to help with serviceability.

  4. Redefining Accessibility on High-Stakes Tests for Postsecondary College Students with Learning Disabilities in an Era of Technology

    ERIC Educational Resources Information Center

    Banerjee, Manju; Gregg, Noel

    2008-01-01

    Unprecedented increases in the use of technologies throughout postsecondary education and the workplace are redefining traditional concepts of accessibility during testing for college students with learning disabilities. High stakes testing practices are under pressure to change. The challenge for professionals is to ensure that tests are designed…

  5. When access is an issue: exploring barriers to predictive testing for Huntington disease in British Columbia, Canada

    PubMed Central

    Hawkins, Alice K; Creighton, Susan; Hayden, Michael R

    2013-01-01

    Predictive testing (PT) for Huntington disease (HD) requires several in-person appointments. This requirement may be a barrier to testing so that at risk individuals do not realize the potential benefits of PT. To understand the obstacles to PT in terms of the accessibility of services, as well as exploring mechanisms by which this issue may be addressed, we conducted an interview study of individuals at risk for HD throughout British Columbia, Canada. Results reveal that the accessibility of PT can be a barrier for two major reasons: distance and the inflexibility of the testing process. Distance is a structural barrier, and relates to the time and travel required to access PT, the financial and other opportunity costs associated with taking time away from work and family to attend appointments and the stress of navigating urban centers. The inflexibility of the testing process barrier relates to the emotional and psychological accessibility of PT. The results of the interview study reveal that there are access barriers to PT that deter individuals from receiving the support, information and counseling they require. What makes accessibility of PT services important is not just that it may result in differences in quality of life and care, but because these differences may be addressed with creative and adaptable solutions in the delivery of genetic services. The study findings underscore the need for us to rethink and personalize the way we deliver such services to improve access issues to prevent inequities in the health care system. PMID:22781094

  6. The spaced antenna drift method

    NASA Technical Reports Server (NTRS)

    Hocking, W. K.

    1983-01-01

    The spaced antenna drift method is a simple and relatively inexpensive method for determination of atmospheric wind velocities using radars. The technique has been extensively tested in the mesosphere at high and medium frequencies, and found to give reliable results. Recently, the method has also been applied to VHF observations of the troposphere and stratosphere, and results appear to be reliable. This paper discusses briefly the principle of the method, and investigates both its strengths and weaknesses. Some discussions concerning criticisms of the technique are also given, and it is concluded that while these criticisms may be of some concern at times, appropriate care can ensure that the method is at least as viable as any other method of remote wind measurement. At times, the technique has definite advantages.

  7. The ARGUS microvertex drift chamber

    NASA Astrophysics Data System (ADS)

    Michel, E.; Schmidt-Parzefall, W.; Appuhn, R. D.; Buchmüller, J.; Kolanoski, H.; Kreimeier, B.; Lange, A.; Siegmund, T.; Walther, A.; Edwards, K. W.; Fernholz, R. C.; Kapitza, H.; MacFarlane, D. B.; O'Neill, M.; Parsons, J. A.; Prentice, J. D.; Seidel, S. C.; Tsipolitis, G.; Ball, S.; Babaev, A.; Danilov, M.; Tichomirov, I.

    1989-11-01

    The ARGUS collaboration is currently building a new microvertex drift chamber (μVDC) as an upgrade of their detector. The μVDC is optimized for B-meson physics at DORIS energies. Important design features are minimal multiple scattering for low-momentum particles and three-dimensional reconstruction of decay vertices with equal resolutions in r- φ and r- z. Vertex resolutions of 15-25 μm are expected. Prototypes of the μVDC have been tested with different gas mixtures at various pressures. Spatial resolutions as small as 20 μm were obtained using CO 2/propane at 4 bar and DME at 1 bar. New readout electronics have been developed for the μVDC aiming at low thresholds for the TDC measurements. Employing a novel idea for noise and cross-talk suppression, which is based on a discrimination against short pulses, very low threshold settings are possible.

  8. Improving Inpatient Surveys: Web-Based Computer Adaptive Testing Accessed via Mobile Phone QR Codes

    PubMed Central

    2016-01-01

    Background The National Health Service (NHS) 70-item inpatient questionnaire surveys inpatients on their perceptions of their hospitalization experience. However, it imposes more burden on the patient than other similar surveys. The literature shows that computerized adaptive testing (CAT) based on item response theory can help shorten the item length of a questionnaire without compromising its precision. Objective Our aim was to investigate whether CAT can be (1) efficient with item reduction and (2) used with quick response (QR) codes scanned by mobile phones. Methods After downloading the 2008 inpatient survey data from the Picker Institute Europe website and analyzing the difficulties of this 70-item questionnaire, we used an author-made Excel program using the Rasch partial credit model to simulate 1000 patients’ true scores followed by a standard normal distribution. The CAT was compared to two other scenarios of answering all items (AAI) and the randomized selection method (RSM), as we investigated item length (efficiency) and measurement accuracy. The author-made Web-based CAT program for gathering patient feedback was effectively accessed from mobile phones by scanning the QR code. Results We found that the CAT can be more efficient for patients answering questions (ie, fewer items to respond to) than either AAI or RSM without compromising its measurement accuracy. A Web-based CAT inpatient survey accessed by scanning a QR code on a mobile phone was viable for gathering inpatient satisfaction responses. Conclusions With advances in technology, patients can now be offered alternatives for providing feedback about hospitalization satisfaction. This Web-based CAT is a possible option in health care settings for reducing the number of survey items, as well as offering an innovative QR code access. PMID:26935793

  9. Stability evaluation of the Panel 1 rooms and the E140 drift at WIPP

    SciTech Connect

    Maleki, H.; Chaturvedi, L.

    1996-08-01

    WIPP, intended for underground permanent disposal of defense transuranic waste, is located 40 km east of Carlsbad at a depth of 655 m in the salt beds of the 600-m thick Permian Salado Formation. It will consist of 56 ``rooms`` each 91.5 m long, 10 m wide, and 4 m high, grouped in 8 ``panels`` of 7 rooms each. About 7.5 km of access drifts will also be provided. Excavation began in 1982 and surface/access/test facilities and one panel were completed by 1988, many years before it could be used. Current plans are to start emplacing waste in WIPP in 1998 and continue for 35 years. The north- south drift E140 is the widest (25 ft) of the four main north-south drifts and is the main north-south passage. Plans to conduct experiments with waste in 1993 were abandoned, and the plan now is to use panel 1 for permanent disposal of waste starting in 1998. The stability evaluation resulted in the conclusion that, while it would be possible to safely use portions of panel 1 for waste emplacement, it would be best to abandon panel 1 and mine a new panel after the decision has been made to use WIPP as a repository and the necessary permits obtained.

  10. Voluntary counseling and testing (VCT) services and their contribution to access to HIV diagnosis in Brazil.

    PubMed

    Grangeiro, Alexandre; Escuder, Maria Mercedes; Veras, Maria Amélia; Barreira, Draurio; Ferraz, Dulce; Kayano, Jorge

    2009-09-01

    The Voluntary Counseling and Testing (VCT) Network was implemented in Brazil in the 1980s to promote anonymous and confidential access to HIV diagnosis. As a function of the population and dimensions of the local epidemic, the study assessed the network's coverage, using data from a self-applied questionnaire and data from the Information Technology Department of the Unified National Health System (SUS), UNDP, and National STD/AIDS Program. The Student t test was used for comparison of means and the chi-square test for proportions. Brazil has 383 VCT centers, covering 48.9% of the population and 69.2% of the AIDS cases. The network has been implemented predominantly in regions where the epidemic shows a relevant presence, but 85.3% of the cities with high HIV incidence lack VCT centers; absence of VCT was associated with more limited health infrastructure and worse social indicators. A slowdown in expansion of the network was observed, with VCT Centers implemented on average 16 years after the first AIDS case in the given municipality. The number of HIV tests performed under the SUS is 2.3 times higher in cities with VCT centers. The network's scope is limited, thus minimizing the contribution by these services to the supply of HIV diagnosis in Brazil.

  11. Drift chamber tracking with a VLSI neural network

    SciTech Connect

    Lindsey, C.S.; Denby, B.; Haggerty, H.; Johns, K.

    1992-10-01

    We have tested a commercial analog VLSI neural network chip for finding in real time the intercept and slope of charged particles traversing a drift chamber. Voltages proportional to the drift times were input to the Intel ETANN chip and the outputs were recorded and later compared off line to conventional track fits. We will discuss the chamber and test setup, the chip specifications, and results of recent tests. We`ll briefly discuss possible applications in high energy physics detector triggers.

  12. Construction Progress of the S-IC Test Stand-Block House Access Tunnel

    NASA Technical Reports Server (NTRS)

    1962-01-01

    At its founding, the Marshall Space Flight Center (MSFC) inherited the Army's Jupiter and Redstone test stands, but much larger facilities were needed for the giant stages of the Saturn V. From 1960 to 1964, the existing stands were remodeled and a sizable new test area was developed. The new comprehensive test complex for propulsion and structural dynamics was unique within the nation and the free world, and they remain so today because they were constructed with foresight to meet the future as well as on going needs. Construction of the S-IC Static test stand complex began in 1961 in the west test area of MSFC, and was completed in 1964. The S-IC static test stand was designed to develop and test the 138-ft long and 33-ft diameter Saturn V S-IC first stage, or booster stage, weighing in at 280,000 pounds. Required to hold down the brute force of a 7,500,000-pound thrust produced by 5 F-1 engines, the S-IC static test stand was designed and constructed with the strength of hundreds of tons of steel and 12,000,000 pounds of cement, planted down to bedrock 40 feet below ground level. The foundation walls, constructed with concrete and steel, are 4 feet thick. The base structure consists of four towers with 40-foot-thick walls extending upward 144 feet above ground level. The structure was topped by a crane with a 135-foot boom. With the boom in the upright position, the stand was given an overall height of 405 feet, placing it among the highest structures in Alabama at the time. In addition to the stand itself, related facilities were constructed during this time. Built directly east of the test stand was the Block House, which served as the control center for the test stand. The two were connected by a narrow access tunnel which housed the cables for the controls. This construction photo taken August 17, 1962 depicts a view of the Block House from the test stand site. The tunnel opening is visible in the forefront center of the photo.

  13. Drift-Scale Radionuclide Transport

    SciTech Connect

    J. Houseworth

    2004-09-22

    The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

  14. Construction Progress of the S-IC Test Stand-Access Tunnel

    NASA Technical Reports Server (NTRS)

    1962-01-01

    At its founding, the Marshall Space Flight Center (MSFC) inherited the Army's Jupiter and Redstone test stands, but much larger facilities were needed for the giant stages of the Saturn V. From 1960 to 1964, the existing stands were remodeled and a sizable new test area was developed. The new comprehensive test complex for propulsion and structural dynamics was unique within the nation and the free world, and they remain so today because they were constructed with foresight to meet the future as well as on going needs. Construction of the S-IC Static test stand complex began in 1961 in the west test area of MSFC, and was completed in 1964. The S-IC static test stand was designed to develop and test the 138-ft long and 33-ft diameter Saturn V S-IC first stage, or booster stage, weighing in at 280,000 pounds. Required to hold down the brute force of a 7,500,000-pound thrust produced by 5 F-1 engines, the S-IC static test stand was designed and constructed with the strength of hundreds of tons of steel and 12,000,000 pounds of cement, planted down to bedrock 40 feet below ground level. The foundation walls, constructed with concrete and steel, are 4 feet thick. The base structure consists of four towers with 40-foot-thick walls extending upward 144 feet above ground level. The structure was topped by a crane with a 135-foot boom. With the boom in the upright position, the stand was given an overall height of 405 feet, placing it among the highest structures in Alabama at the time. In addition to the stand itself, related facilities were constructed during this time. Built directly east of the test stand was the Block House, which served as the control center for the test stand. The two were connected by a narrow tunnel which housed the cables for the controls. This photograph, taken on May 21, 1962 depicts the access tunnel construction.

  15. Construction Progress of the S-IC Test Stand-Block House Access Tunnel

    NASA Technical Reports Server (NTRS)

    1962-01-01

    At its founding, the Marshall Space Flight Center (MSFC) inherited the Army's Jupiter and Redstone test stands, but much larger facilities were needed for the giant stages of the Saturn V. From 1960 to 1964, the existing stands were remodeled and a sizable new test area was developed. The new comprehensive test complex for propulsion and structural dynamics was unique within the nation and the free world, and they remain so today because they were constructed with foresight to meet the future as well as on going needs. Construction of the S-IC Static test stand complex began in 1961 in the west test area of MSFC, and was completed in 1964. The S-IC static test stand was designed to develop and test the 138-ft long and 33-ft diameter Saturn V S-IC first stage, or booster stage, weighing in at 280,000 pounds. Required to hold down the brute force of a 7,500,000-pound thrust produced by 5 F-1 engines, the S-IC static test stand was designed and constructed with the strength of hundreds of tons of steel and 12,000,000 pounds of cement, planted down to bedrock 40 feet below ground level. The foundation walls, constructed with concrete and steel, are 4 feet thick. The base structure consists of four towers with 40-foot-thick walls extending upward 144 feet above ground level. The structure was topped by a crane with a 135-foot boom. With the boom in the upright position, the stand was given an overall height of 405 feet, placing it among the highest structures in Alabama at the time. In addition to the stand itself, related facilities were constructed during this time. Built directly east of the test stand was the Block House, which served as the control center for the test stand. The two were connected by a narrow access tunnel which housed the cables for the controls. Construction of the tunnel is depicted in this photo taken June 13, 1962.

  16. Construction Progress of the S-IC Test Stand-Block House Access Tunnel

    NASA Technical Reports Server (NTRS)

    1962-01-01

    At its founding, the Marshall Space Flight Center (MSFC) inherited the Army's Jupiter and Redstone test stands, but much larger facilities were needed for the giant stages of the Saturn V. From 1960 to 1964, the existing stands were remodeled and a sizable new test area was developed. The new comprehensive test complex for propulsion and structural dynamics was unique within the nation and the free world, and they remain so today because they were constructed with foresight to meet the future as well as on going needs. Construction of the S-IC Static test stand complex began in 1961 in the west test area of MSFC, and was completed in 1964. The S-IC static test stand was designed to develop and test the 138-ft long and 33-ft diameter Saturn V S-IC first stage, or booster stage, weighing in at 280,000 pounds. Required to hold down the brute force of a 7,500,000-pound thrust produced by 5 F-1 engines, the S-IC static test stand was designed and constructed with the strength of hundreds of tons of steel and 12,000,000 pounds of cement, planted down to bedrock 40 feet below ground level. The foundation walls, constructed with concrete and steel, are 4 feet thick. The base structure consists of four towers with 40-foot-thick walls extending upward 144 feet above ground level. The structure was topped by a crane with a 135-foot boom. With the boom in the upright position, the stand was given an overall height of 405 feet, placing it among the highest structures in Alabama at the time. In addition to the stand itself, related facilities were constructed during this time. Built directly east of the test stand was the Block House, which served as the control center for the test stand. The two were connected by a narrow access tunnel which housed the cables for the controls. This construction photo, taken October 26, 1962, depicts a view of the Block House tunnel opening.

  17. Inner and outer waste storage vaults with leak-testing accessibility

    SciTech Connect

    Splinter, B.C.

    1985-04-23

    A storage arrangement for waste materials of the type which tend to pollute the environment consists of a waterproof reinforced concrete vault, preferably located underground, and a permanent reinforced concrete storage vault within the underground vault and spaced from the walls thereof by a water lock. Sealed containers filled with chemical or nuclear waste are deposited in the permanent storage vault and sealed therein with bitumen. The underground vault is provided with an access opening to the water lock to enable testing of the water periodically for contamination due to leakage from the permanent storage vault. If no leakage is evident after a predetermined time period has elapsed, the permanent storage vault is removed from the underground vault and shipped to a permanent storage site.

  18. Assessing the Feasibility of In-Situ Aerobic Cometabolism of Chlorinated Solvents by a Single-Well Push-Pull and Natural Gradient Drift Tests in McClellan AFB, CA

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Istok, J. D.; Semprini, L.

    2001-12-01

    A single-well push-pull test has been developed to evaluate in-situ aerobic cometabolic treatment of chlorinated aliphatic hydrocarbons (CAHs), such as trichloroethylene (TCE) and cis-1,2-dichloroethylene (c-DCE). A series of single-well natural gradient drift and push-pull tests were conducted in two monitoring wells at the McClellan Air Force Base, CA, where aquifer is contaminated mainly with c-DCE and TCE. Transport characteristics of dissolved solutes [bromide (tracer), propane (growth substrate), ethylene, propylene (nontoxic surrogates to probe for CAH transformation activity), DO and nitrate (nutrient)] were evaluated in push-pull transport tests by injecting 200-L of groundwater containing the solutes into the aquifer (Push), providing a rest period of 18 hours (Reaction), and then extracting 400-L of the test solution/groundwater mixtures (Pull). Mass balances showed over 95% of the injected bromide was recovered, and the recoveries of the other solutes were comparable with bromide. The dispersion of all the solutes was similar indicating sorption or other partitioning processes were minimal. These results indicate that bromide could be used as a conservative tracer for biological activity tests and that little loss of the dissolved gaseous substrates occurred prior to biostimulation of the aquifer. A series of biostimulation tests were performed by injecting 500 L-groundwater containing propane (6 mg/L), DO (25 mg/L), nitrate (9 mg/L as N) and bromide (100 mg/L) into the aquifer. Temporal groundwater samples were obtained from the injection well under natural gradient drift conditions. With repeating biostimulation tests the rates of both propane and DO utilization were increased significantly. The results demonstrated that the progress of biostimulation could be assessed by injecting and monitoring under natural gradient drift conditions. Successive push-pull activity tests were performed after biostimulation was achieved using the same procedures as

  19. Automated assessment of pain in rats using a voluntarily accessed static weight-bearing test

    PubMed Central

    Kim, Hung Tae; Uchimoto, Kazuhiro; Duellman, Tyler; Yang, Jay

    2015-01-01

    The weight-bearing test is one method to assess pain in rodent animal models; however, the acceptance of this convenient method is limited by the low throughput data acquisition and necessity of confining the rodents to a small chamber. New methods We developed novel data acquisition hardware and software, data analysis software, and a conditioning protocol for an automated high throughput static weight-bearing assessment of pain. With this device, the rats voluntarily enter the weighing chamber, precluding the necessity to restrain the animals and thereby removing the potential stress-induced confounds as well as operator selection bias during data collection. We name this device the Voluntarily Accessed Static Incapacitance Chamber (VASIC). Results Control rats subjected to the VASIC device provided hundreds of weight-bearing data points in a single behavioral assay. Chronic constriction injury (CCI) surgery and paw pad injection of complete Freund's adjuvant (CFA) or carrageenan in rats generated hundreds of weight-bearing data during a 30 minute recording session. Rats subjected to CCI, CFA, or carrageenan demonstrated the expected bias in weight distribution favoring the un-operated leg, and the analgesic effect of i.p. morphine was demonstrated. In comparison with existing methods, brief water restriction encouraged the rats to enter the weighing chamber to access water, and an infrared detector confirmed the rat position with feet properly positioned on the footplates, triggering data collection. This allowed hands-off measurement of weight distribution data reducing operator selection bias. Conclusion The VASIC device should enhance the hands-free parallel collection of unbiased weight-bearing data in a high throughput manner, allowing further testing of this behavioral measure as an effective assessment of pain in rodents. PMID:26143745

  20. Giving office-based physicians electronic access to patients' prior imaging and lab results did not deter ordering of tests.

    PubMed

    McCormick, Danny; Bor, David H; Woolhandler, Stephanie; Himmelstein, David U

    2012-03-01

    Policy-based incentives for health care providers to adopt health information technology are predicated on the assumption that, among other things, electronic access to patient test results and medical records will reduce diagnostic testing and save money. To test the generalizability of findings that support this assumption, we analyzed the records of 28,741 patient visits to a nationally representative sample of 1,187 office-based physicians in 2008. Physicians' access to computerized imaging results (sometimes, but not necessarily, through an electronic health record) was associated with a 40-70 percent greater likelihood of an imaging test being ordered. The electronic availability of lab test results was also associated with ordering of additional blood tests. The availability of an electronic health record in itself had no apparent impact on ordering; the electronic access to test results appears to have been the key. These findings raise the possibility that, as currently implemented, electronic access does not decrease test ordering in the office setting and may even increase it, possibly because of system features that are enticements to ordering. We conclude that use of these health information technologies, whatever their other benefits, remains unproven as an effective cost-control strategy with respect to reducing the ordering of unnecessary tests.

  1. Determination of selection criteria for spray drift reduction from atomization data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When testing and evaluating drift reduction technologies (DRT), there are different metrics that can be used to determine if the technology reduces drift as compared to a reference system. These metrics can include reduction in percent of fine drops, measured spray drift from a field trial, or comp...

  2. Access to CD4 Testing for Rural HIV Patients: Findings from a Cohort Study in Zimbabwe

    PubMed Central

    Vogt, Florian; Tayler-Smith, Katie; Bernasconi, Andrea; Makondo, Eliphas; Taziwa, Fabian; Moyo, Buhlebenkosi; Havazvidi, Liberty; Satyanarayana, Srinath; Manzi, Marcel; Khogali, Mohammed; Reid, Anthony

    2015-01-01

    Background CD4 cell count measurement remains an important diagnostic tool for HIV care in developing countries. Insufficient laboratory capacity in rural Sub-Saharan Africa is frequently mentioned but data on the impact at an individual patient level are lacking. Urban-rural discrepancies in CD4 testing have not been quantified to date. Such evidence is crucial for public health planning and to justify new yet more expensive diagnostic procedures that could circumvent access constraints in rural areas. Objective To compare CD4 testing among rural and urban HIV patients during the first year of treatment. Methods Records from 2,145 HIV positive adult patients from a Médecins sans Frontières (Doctors without Borders) HIV project in Beitbridge, Zimbabwe, during 2011 and 2012 were used for a retrospective cohort analysis. Covariate-adjusted risk ratios were calculated to estimate the effects of area of residence on CD4 testing at treatment initiation, six and 12 months among rural and urban patients. Findings While the proportion of HIV patients returning for medical consultations at six and 12 months decreased at a similar rate in both patient groups, CD4 testing during consultations dropped to 21% and 8% for urban, and 2% and 1% for rural patients at six and 12 months, respectively. Risk ratios for missing CD4 testing were 0.8 (95% CI 0.7-0.9), 9.2 (95% CI 5.5-15.3), and 7.6 (95% 3.7-17.1) comparing rural versus urban patients at treatment initiation, six and 12 months, respectively. Conclusions CD4 testing was low overall, and particularly poor in rural patients. Difficulties with specimen transportation were probably a major factor underlying this difference and requires new diagnostic approaches. Our findings point to severe health system constraints in providing CD4 testing overall that need to be addressed if effective monitoring of HIV patients is to be achieved, whether by alternative CD4 diagnostics or newly-recommended routine viral load testing. PMID

  3. CTF Void Drift Validation Study

    SciTech Connect

    Salko, Robert K.; Gosdin, Chris; Avramova, Maria N.; Gergar, Marcus

    2015-10-26

    This milestone report is a summary of work performed in support of expansion of the validation and verification (V&V) matrix for the thermal-hydraulic subchannel code, CTF. The focus of this study is on validating the void drift modeling capabilities of CTF and verifying the supporting models that impact the void drift phenomenon. CTF uses a simple turbulent-diffusion approximation to model lateral cross-flow due to turbulent mixing and void drift. The void drift component of the model is based on the Lahey and Moody model. The models are a function of two-phase mass, momentum, and energy distribution in the system; therefore, it is necessary to correctly model the ow distribution in rod bundle geometry as a first step to correctly calculating the void distribution due to void drift.

  4. Dealing with the unexpected: consumer responses to direct-access BRCA mutation testing.

    PubMed

    Francke, Uta; Dijamco, Cheri; Kiefer, Amy K; Eriksson, Nicholas; Moiseff, Bianca; Tung, Joyce Y; Mountain, Joanna L

    2013-01-01

    appreciated learning their BRCA mutation status. Conclusions. Direct access to BRCA mutation tests, considered a model for high-risk actionable genetic tests of proven clinical utility, provided clear benefits to participants. The unexpected information demonstrated a cascade effect as relatives of newly identified carriers also sought testing and more mutation carriers were identified. Given the absence of evidence for serious emotional distress or inappropriate actions in this subset of mutation-positive customers who agreed to be interviewed for this study, broader screening of Ashkenazi Jewish women for these three BRCA mutations should be considered.

  5. The Viability of Hearing Protection Device Fit-Testing at Navy and Marine Corps Accession Points

    PubMed Central

    Federman, Jeremy; Duhon, Christon

    2016-01-01

    Introduction: The viability of hearing protection device (HPD) verification (i.e., fit-testing) on a large scale was investigated to address this gap in a military accession environment. Materials and Methods: Personal Attenuation Ratings (PARs) following self-fitted (SELF-Fit) HPDs were acquired from 320 US Marine Corps training recruits (87.5% male, 12.5% female) across four test protocols (1-, 3-, 5-, and 7- frequency). SELF-Fit failures received follow-up to assess potential causes. Follow-up PARs were acquired (Experimenter fit [EXP-Fit], followed by Subject re-fit [SUB Re-Fit]). EXP-Fit was intended to provide a perception (dubbed “ear canal muscle memory”) of what a correctly fitted HPD should feel like. SUB Re-Fit was completed following EXP-Fit to determine whether a training recruit could duplicate EXP-Fit on her/his own without assistance. Results: A one-way analysis of variance (ANOVA) (N=320) showed that SELF-Fit means differed significantly between protocols (P < 0.001). Post-hoc analyses showed that the 1-freq SELF-Fit mean was significantly lower than all other protocols (P < 0.03) by 5.6 dB or more. No difference was found between the multi-frequency protocols. For recruits who were followed up with EXP-Fit (n=79), across all protocols, a significant (P < 0.001) mean improvement of 25.68 dB (10.99) was found, but PARs did not differ (P = 0.99) between EXP-Fit protocols. For recruits in the 3-freq and 5-freq protocol groups who experienced all three PAR test methods (n=33), PAR methods differed (P < 0.001) but no method by protocol interaction was found (P = 0.46). Post hoc tests showed that both EXP-Fit and SUB Re-Fit had significantly better attenuation than SELF-Fit (P < 0.001), but no difference was found between EXPFit and SUB Re-Fit (P = 0.59). For SELF-Fit, the 1-freq protocol resulted in a 35% pass rate, whereas the 3-, 5-, and 7-freq protocols resulted in >60% pass rates. Results showed that once recruits experienced how HPDs should

  6. Testing the fecundity advantage hypothesis with Sitobion avenae, Rhopalosiphum padi, and Schizaphis graminum (Hemiptera: Aphididae) feeding on ten wheat accessions

    PubMed Central

    Hu, Xiang-Shun; Liu, Xiao-Feng; Thieme, Thomas; Zhang, Gai-Sheng; Liu, Tong-Xian; Zhao, Hui-Yan

    2015-01-01

    The fecundity advantage hypothesis suggests that females with a large body size produce more offspring than smaller females. We tested this hypothesis by exploring the correlations between life-history traits of three aphid species feeding on ten wheat accessions at three levels of analysis with respect to the host plant: overall, inter-accession, and intra-accession. We found that fecundity was significantly correlated with mean relative growth rate (MRGR), weight gain, and development time, and that the faster aphid develops the greater body and fecundity, depending on aphid species, wheat accession, and analyses level. Larger aphids of all three species produced more offspring overall; this held true for Sitobion avenae and Schizaphis graminum at the inter-accession level, and for S. avenae, Rhopalosiphum padi, and S. graminum for three, five, and eight accessions respectively at the intra-accession level. Only one correlation, between intrinsic rates of natural increase (rm) and MRGR, was significant for all aphid species at all three analysis levels. A more accurate statement of the fecundity advantage hypothesis is that cereal aphids with greater MRGR generally maintain higher rm on wheat. Our results also provide a method for exploring relationships between individual life-history traits and population dynamics for insects on host plants. PMID:26680508

  7. Drift mode accelerometry for spaceborne gravity measurements

    NASA Astrophysics Data System (ADS)

    Conklin, John W.

    2015-11-01

    A drift mode accelerometer is a precision instrument for spacecraft that overcomes much of the acceleration noise and readout dynamic range limitations of traditional electrostatic accelerometers. It has the potential of achieving acceleration noise performance similar to that of drag-free systems over a restricted frequency band without the need for external drag-free control or continuous spacecraft propulsion. Like traditional accelerometers, the drift mode accelerometer contains a high-density test mass surrounded by an electrode housing, which can control and sense all six degrees of freedom of the test mass. Unlike traditional accelerometers, the suspension system is operated with a low duty cycle so that the limiting suspension force noise only acts over brief, known time intervals, which can be neglected in the data analysis. The readout is performed using a laser interferometer which is immune to the dynamic range limitations of even the best voltage references typically used to determine the inertial acceleration of electrostatic accelerometers. The drift mode accelerometer is a novel offshoot of the like-named operational mode of the LISA Pathfinder spacecraft, in which its test mass suspension system is cycled on and off to estimate the acceleration noise associated with the front-end electronics. This paper presents the concept of a drift mode accelerometer, describes the operation of such a device, develops models for its performance with respect to non-drag-free satellite geodesy and gravitational wave missions, and discusses plans for testing the performance of a prototype sensor in the laboratory using torsion pendula.

  8. 3-dimensional Oil Drift Simulations

    NASA Astrophysics Data System (ADS)

    Wettre, C.; Reistad, M.; Hjøllo, B.Å.

    Simulation of oil drift has been an ongoing activity at the Norwegian Meteorological Institute since the 1970's. The Marine Forecasting Centre provides a 24-hour service for the Norwegian Pollution Control Authority and the oil companies operating in the Norwegian sector. The response time is 30 minutes. From 2002 the service is extended to simulation of oil drift from oil spills in deep water, using the DeepBlow model developed by SINTEF Applied Chemistry. The oil drift model can be applied both for instantaneous and continuous releases. The changes in the mass of oil and emulsion as a result of evaporation and emulsion are computed. For oil spill at deep water, hydrate formation and gas dissolution are taken into account. The properties of the oil depend on the oil type, and in the present version 64 different types of oil can be simulated. For accurate oil drift simulations it is important to have the best possible data on the atmospheric and oceanic conditions. The oil drift simulations at the Norwegian Meteorological Institute are always based on the most updated data from numerical models of the atmosphere and the ocean. The drift of the surface oil is computed from the vectorial sum of the surface current from the ocean model and the wave induced Stokes drift computed from wave energy spectra from the wave prediction model. In the new model the current distribution with depth is taken into account when calculating the drift of the dispersed oil droplets. Salinity and temperature profiles from the ocean model are needed in the DeepBlow model. The result of the oil drift simulations can be plotted on sea charts used for navigation, either as trajectory plots or particle plots showing the situation at a given time. The results can also be sent as data files to be included in the user's own GIS system.

  9. Hemoglobin Drift after Cardiac Surgery

    PubMed Central

    George, Timothy J.; Beaty, Claude A.; Kilic, Arman; Haggerty, Kara A.; Frank, Steven M.; Savage, William J.; Whitman, Glenn J.

    2013-01-01

    Introduction Recent literature suggests that a restrictive approach to red blood cell transfusions is associated with improved outcomes in cardiac surgery (CS) patients. Even in the absence of bleeding, intravascular fluid shifts cause hemoglobin levels to drift postoperatively, possibly confounding the decision to transfuse. We undertook this study to define the natural progression of hemoglobin levels in postoperative CS patients. Methods We included all CS patients from 10/10-03/11 who did not receive a postoperative transfusion. Primary stratification was by intraoperative transfusion status. Change in hemoglobin was evaluated relative to the initial postoperative hemoglobin. Maximal drift was defined as the maximum minus the minimum hemoglobin for a given hospitalization. Final drift was defined as the difference between initial and discharge hemoglobin. Results Our final cohort included 199 patients, 71(36%) received an intraoperative transfusion while 128(64%) did not. The average initial and final hemoglobin for all patients were 11.0±1.4g/dL and 9.9±1.3g/dL, respectively, an final drift of 1.1±1.4g/dL. The maximal drift was 1.8±1.1g/dL and was similar regardless of intraoperative transfusion status(p=0.9). Although all patients’ hemoglobin initially dropped, 79% of patients reached a nadir and experienced a mean recovery of 0.7±0.7g/dL by discharge. On multivariable analysis, increasing CPB time was significantly associated with total hemoglobin drift(Coefficient/hour: 0.3[0.1–0.5]g/dL, p=0.02). Conclusions In this first report of hemoglobin drift following CS, although all postoperative patients experienced downward hemoglobin drift, 79% of patients exhibited hemoglobin recovery prior to discharge. Physicians should consider the eventual upward hemoglobin drift prior to administering red cell transfusions. PMID:22609121

  10. Temperature Induced Voltage Offset Drifts in Silicon Carbide Pressure Sensors

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S.; Lukco, Dorothy; Nguyen, Vu; Savrun, Ender

    2012-01-01

    We report the reduction of transient drifts in the zero pressure offset voltage in silicon carbide (SiC) pressure sensors when operating at 600 C. The previously observed maximum drift of +/- 10 mV of the reference offset voltage at 600 C was reduced to within +/- 5 mV. The offset voltage drifts and bridge resistance changes over time at test temperature are explained in terms of the microstructure and phase changes occurring within the contact metallization, as analyzed by Auger electron spectroscopy and field emission scanning electron microscopy. The results have helped to identify the upper temperature reliable operational limit of this particular metallization scheme to be 605 C.

  11. Pulsed Drift Tube Accelerator

    SciTech Connect

    Faltens, A.

    2004-10-25

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K{sup +} beams at a constant line charge density of 0.25{micro} C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2{micro}s rectangular 1 Ampere C{sub s}{sup +} beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K{sup +}, was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1

  12. Petrology and geochemistry of the Grouse Canyon Member of the Belted Range Tuff, Rock-Mechanics Drift, U12g Tunnel, Nevada Test Site

    SciTech Connect

    Connolly, J.R.; Mansker, W.L.; Hicks, R.; Allen, C.C.; Husler, J.; Keil, K.; Lappin, A.R.

    1983-04-01

    G-Tunnel at Nevada Test Site (NTS) is the site of thermal and thermomechanical experiments examining the feasibility of emplacing heat-producing nuclear wastes in silicic tuffs. This report describes the general stratigraphy, mineralogy, and bulk chemistry of welded portions of the Grouse Canyon Member of the Belted Range Tuff, the unit in which most of these experiments will be performed. The geologic characteristics of the Grouse Canyon Member are compared with those of the Topopah Spring Member of the Paintbrush Tuff, presently the preferred horizon for an actual waste repository at Yucca Mountain, near the southwest boundary of Nevada Test Site. This comparison suggests that test results obtained in welded tuff from G-Tunnel are applicable, with limitations, to evaluation of the Topopah Spring Member at Yucca Mountain.

  13. Time-dependent drift Hamiltonian

    SciTech Connect

    Boozer, A.H.

    1983-03-01

    The lowest-order drift equations are given in a canonical magnetic coordinate form for time-dependent magnetic and electric fields. The advantages of the canonical Hamiltonian form are also discussed.

  14. Development and Testing of a Conceptual Model Regarding Men's Access to Health Care.

    PubMed

    Leone, James E; Rovito, Michael J; Mullin, Elizabeth M; Mohammed, Shan D; Lee, Christina S

    2017-03-01

    Epidemiologic data suggest men often experience excessive morbidity and early mortality, possibly compromising family and community health over the lifespan. Moreover, the negative financial/economic consequences affected by poor male health outcomes also has been of great concern in the United States and abroad. Early and consistent access to preventative health care may improve health outcomes; however, men are far less likely to access these services. The purpose of this study was to understand what factors preclude men from accessing health care. We surveyed 485 participants using a 58-item online survey built from a conceptual model previously developed by the researchers using hegemonic masculinity theory, the theory of normative contentment, and the health belief model. For men, three items significantly ( ps < .05) predicted whether they had seen a health care provider in the past year: "I/Men do not access healthcare because I do not think there is anything wrong with me," "My health is only about me," and "I/Men do not access healthcare because most men in my family do not access healthcare." Other correlations of practical significance also were noted. Results suggest gender norms and masculine ideals may play a primary role in how men access preventative health care. Future programming targeting males should consider barriers and plan programs that are gender-sensitive in addition to being gender-specific. Clinical implications are discussed.

  15. Mining Concept-Drifting Data Streams

    NASA Astrophysics Data System (ADS)

    Wang, Haixun; Yu, Philip S.; Han, Jiawei

    Knowledge discovery from infinite data streams is an important and difficult task. We are facing two challenges, the overwhelming volume and the concept drifts of the streaming data. In this chapter, we introduce a general framework for mining concept-drifting data streams using weighted ensemble classifiers. We train an ensemble of classification models, such as C4.5, RIPPER, naive Bayesian, etc., from sequential chunks of the data stream. The classifiers in the ensemble are judiciously weighted based on their expected classification accuracy on the test data under the time-evolving environment. Thus, the ensemble approach improves both the efficiency in learning the model and the accuracy in performing classification. Our empirical study shows that the proposed methods have substantial advantage over single-classifier approaches in prediction accuracy, and the ensemble framework is effective for a variety of classification models.

  16. Does insecticide drift adversely affect grasshoppers (Orthoptera: Saltatoria) in field margins? A case study combining laboratory acute toxicity testing with field monitoring data.

    PubMed

    Bundschuh, Rebecca; Schmitz, Juliane; Bundschuh, Mirco; Brühl, Carsten Albrecht

    2012-08-01

    The current terrestrial risk assessment of insecticides regarding nontarget arthropods considers exclusively beneficial organisms, whereas herbivorous insects, such as grasshoppers, are ignored. However, grasshoppers living in field margins or meadows adjacent to crops may potentially be exposed to insecticides due to contact with or ingestion of contaminated food. Therefore, the present study assessed effects of five active ingredients of insecticides (dimethoate, pirimicarb, imidacloprid, lambda-cyhalothrin, and deltamethrin) on the survival of Chorthippus sp. grasshopper nymphs by considering two routes of exposure (contact and oral). The experiments were accompanied by monitoring field margins that neighbored cereals, vineyards, and orchards. Grasslands were used as reference sites. The laboratory toxicity tests revealed a sensitivity of grasshoppers with regard to the insecticides tested in the present study similar to that of the standard test species used in arthropod risk assessments. In the field monitoring program, increasing grasshopper densities were detected with increasing field margin width next to cereals and vineyards, but densities remained low over the whole range of field margins from 0.5 to 20 m next to orchards. Grasshopper densities equivalent to those of grassland sites were only observed in field margins exceeding 9 m in width, except for field margins next to orchards. These results may indicate that current insecticide risk assessments are insufficiently protective for grasshoppers in field margins.

  17. Drift-Scale THC Seepage Model

    SciTech Connect

    C.R. Bryan

    2005-02-17

    The purpose of this report (REV04) is to document the thermal-hydrologic-chemical (THC) seepage model, which simulates the composition of waters that could potentially seep into emplacement drifts, and the composition of the gas phase. The THC seepage model is processed and abstracted for use in the total system performance assessment (TSPA) for the license application (LA). This report has been developed in accordance with ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Post-Processing Analysis for THC Seepage) Report Integration'' (BSC 2005 [DIRS 172761]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this report. The plan for validation of the models documented in this report is given in Section 2.2.2, ''Model Validation for the DS THC Seepage Model,'' of the TWP. The TWP (Section 3.2.2) identifies Acceptance Criteria 1 to 4 for ''Quantity and Chemistry of Water Contacting Engineered Barriers and Waste Forms'' (NRC 2003 [DIRS 163274]) as being applicable to this report; however, in variance to the TWP, Acceptance Criterion 5 has also been determined to be applicable, and is addressed, along with the other Acceptance Criteria, in Section 4.2 of this report. Also, three FEPS not listed in the TWP (2.2.10.01.0A, 2.2.10.06.0A, and 2.2.11.02.0A) are partially addressed in this report, and have been added to the list of excluded FEPS in Table 6.1-2. This report has been developed in accordance with LP-SIII.10Q-BSC, ''Models''. This report documents the THC seepage model and a derivative used for validation, the Drift Scale Test (DST) THC submodel. The THC seepage model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC submodel uses a drift

  18. Ocean modelling aspects for drift applications

    NASA Astrophysics Data System (ADS)

    Stephane, L.; Pierre, D.

    2010-12-01

    Nowadays, many authorities in charge of rescue-at-sea operations lean on operational oceanography products to outline research perimeters. Moreover, current fields estimated with sophisticated ocean forecasting systems can be used as input data for oil spill/ adrift object fate models. This emphasises the necessity of an accurate sea state forecast, with a mastered level of reliability. This work focuses on several problems inherent to drift modeling, dealing in the first place with the efficiency of the oceanic current field representation. As we want to discriminate the relevance of a particular physical process or modeling option, the idea is to generate series of current fields of different characteristics and then qualify them in term of drift prediction efficiency. Benchmarked drift scenarios were set up from real surface drifters data, collected in the Mediterranean sea and off the coasts of Angola. The time and space scales that we are interested in are about 72 hr forecasts (typical timescale communicated in case of crisis), for distance errors that we hope about a few dozen of km around the forecast (acceptable for reconnaissance by aircrafts) For the ocean prediction, we used some regional oceanic configurations based on the NEMO 2.3 code, nested into Mercator 1/12° operational system. Drift forecasts were computed offline with Mothy (Météo France oil spill modeling system) and Ariane (B. Blanke, 1997), a Lagrangian diagnostic tool. We were particularly interested in the importance of the horizontal resolution, vertical mixing schemes, and any processes that may impact the surface layer. The aim of the study is to ultimately point at the most suitable set of parameters for drift forecast use inside operational oceanic systems. We are also motivated in assessing the relevancy of ensemble forecasts regarding determinist predictions. Several tests showed that mis-described observed trajectories can finally be modelled statistically by using uncertainties

  19. The Drifting Star

    NASA Astrophysics Data System (ADS)

    2008-04-01

    By studying in great detail the 'ringing' of a planet-harbouring star, a team of astronomers using ESO's 3.6-m telescope have shown that it must have drifted away from the metal-rich Hyades cluster. This discovery has implications for theories of star and planet formation, and for the dynamics of our Milky Way. ESO PR Photo 09a/08 ESO PR Photo 09a/08 Iota Horologii The yellow-orange star Iota Horologii, located 56 light-years away towards the southern Horologium ("The Clock") constellation, belongs to the so-called "Hyades stream", a large number of stars that move in the same direction. Previously, astronomers using an ESO telescope had shown that the star harbours a planet, more than 2 times as large as Jupiter and orbiting in 320 days (ESO 12/99). But until now, all studies were unable to pinpoint the exact characteristics of the star, and hence to understand its origin. A team of astronomers, led by Sylvie Vauclair from the University of Toulouse, France, therefore decided to use the technique of 'asteroseismology' to unlock the star's secrets. "In the same way as geologists monitor how seismic waves generated by earthquakes propagate through the Earth and learn about the inner structure of our planet, it is possible to study sound waves running through a star, which forms a sort of large, spherical bell," says Vauclair. The 'ringing' from this giant musical instrument provides astronomers with plenty of information about the physical conditions in the star's interior. And to 'listen to the music', the astronomers used one of the best instruments available. The observations were conducted in November 2006 during 8 consecutive nights with the state-of-the-art HARPS spectrograph mounted on the ESO 3.6-m telescope at La Silla. Up to 25 'notes' could be identified in the unique dataset, most of them corresponding to waves having a period of about 6.5 minutes. These observations allowed the astronomers to obtain a very precise portrait of Iota Horologii: its

  20. A Case-Series Test of the Interactive Two-Step Model of Lexical Access: Predicting Word Repetition from Picture Naming

    ERIC Educational Resources Information Center

    Dell, Gary S.; Martin, Nadine; Schwartz, Myrna F.

    2007-01-01

    Lexical access in language production, and particularly pathologies of lexical access, are often investigated by examining errors in picture naming and word repetition. In this article, we test a computational approach to lexical access, the two-step interactive model, by examining whether the model can quantitatively predict the repetition-error…

  1. Eliminating access to anonymous HIV antibody testing in North Carolina: effects on HIV testing and partner notification.

    PubMed

    Kassler, W J; Meriwether, R A; Klimko, T B; Peterman, T A; Zaidi, A

    1997-03-01

    Anonymous HIV testing may attract persons who might otherwise not be tested but may hinder partner notification. We evaluated the effects on North Carolina's HIV testing and partner notification programs of policy changes that eliminated and later restored anonymous testing in 82 counties. We used an interrupted time-series design to compare counties eliminating with counties retaining anonymous testing. We analyzed HIV testing and partner notification data from before, during, and after elimination of anonymous testing. After elimination of anonymous testing in 82 counties, the mean monthly level of testing (+/- SE) increased by 45%, or 548 (+/- 123) tests per month, while in 18 counties that retained anonymous testing, there was a 63% increase, or 802 (+/- 162) tests per month (p > .05). Among men of all races, testing increased by 16%, or 155 (+/- 35) tests per month, in counties that eliminated anonymous testing; and by 51%, or 305 (+/- 42) tests per month (p < .05), in counties that retained anonymous testing. After elimination of anonymous testing, both county types experienced similar increases in the rate of partners notified. However, partner notification was more successful if the index patient was tested confidentially; 2.7 times as many partners per index patient were notified and counseled. There was no effect on testing or on partner notification rates following restoration of anonymous testing. Substantial community opposition to eliminating anonymous testing was encountered. The policy change appeared to result in a slight decrease in testing among men and a slight increase in partners notified. Programs considering the elimination of anonymous testing should weigh these potential gains and losses, as well as the impact on relationships between the public health and advocacy communities

  2. Drift distance survey in DPIS for high current beam production

    SciTech Connect

    Kanesue,T.; Okamura, M.; Kondo, K.; Tamura, J.; Kashiwagi, H.; Zhang, Z.

    2009-09-20

    In a laser ion source, plasma drift distance is one of the most important design parameters. Ion current density and beam pulse width are defined by plasma drift distance between laser target and beam extraction position. In direct plasma injection scheme (DPIS), which uses a laser ion source and Radio Frequency Quadrupole (RFQ) linac, we can apply relatively higher electric field at the beam extraction due to the unique shape of a positively biased electrode. However, when we aim at very high current acceleration like several tens of mA, we observed mismatched beam extraction conditions. We tested three different ion current at ion extraction region by changing plasma drift distance to study better extraction condition. In this experiment, C{sup 6+} beam was accelerated. We confirmed that the matching condition can be improved by controlling plasma drift distance.

  3. Drift-Scale Radionuclide Transport

    SciTech Connect

    P.R. Dixon

    2004-02-17

    The purpose of this Model Report is to document two models for drift-scale radionuclide transport. This has been developed in accordance with ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]), which includes planning documents for the technical work scope, content, and management of this Model Report in Section 1.15, Work Package AUZM11, ''Drift-Scale Radionuclide Transport.'' The technical work scope for this Model Report calls for development of a process-level model and an abstraction model representing diffusive release from the invert to the rocks, partitioned between fracture and matrix, as compared to the fracture-release approach used in the Site Recommendation. The invert is the structure constructed in a drift to provide the floor of that drift. The plan for validation of the models documented in this Model Report is given in Section I-5 of Attachment I in BSC (2002 [160819]). Note that the model validation presented in Section 7 deviates from the technical work plan (BSC 2002 [160819], Section I-5) in that an independent technical review specifically for model validation has not been conducted, nor publication in a peer-reviewed journal. Model validation presented in Section 7 is based on corroboration with alternative mathematical models, which is also called out by the technical work plan (BSC 2002 [160819], Section I-5), and is sufficient based on the requirements of AP-SIII.10Q for model validation. See Section 7 for additional discussion. The phenomenon of flow and transport in the vicinity of the waste emplacement drift are evaluated in this model report under ambient thermal, chemical, and mechanical conditions. This includes the effects of water diversion around an emplacement drift and the flow and transport behavior expected in a fractured rock below the drift. The reason for a separate assessment of drift-scale transport is that the effects of waste emplacement drifts on flow

  4. Genetic drift and the population history of the Irish travellers.

    PubMed

    Relethford, John H; Crawford, Michael H

    2013-02-01

    The Irish Travellers are an itinerant group in Ireland that has been socially isolated. Two hypotheses have been proposed concerning the genetic origin of the Travellers: (1) they are genetically related to Roma populations in Europe that share a nomadic lifestyle or (2) they are of Irish origin, and genetic differences from the rest of Ireland reflect genetic drift. These hypotheses were tested using data on 33 alleles from 12 red blood cell polymorphism loci. Comparison with other European, Roma, and Indian populations shows that the Travellers are genetically distinct from the Roma and Indian populations and most genetically similar to Ireland, in agreement with earlier genetic analyses of the Travellers. However, the Travellers are still genetically distinct from other Irish populations, which could reflect some external gene flow and/or the action of genetic drift in a small group that was descended from a small number of founders. In order to test the drift hypothesis, we analyzed genetic distances comparing the Travellers to four geographic regions in Ireland. These distances were then compared with adjusted distances that account for differential genetic drift using a method developed by Relethford (Hum Biol 68 (1996) 29-44). The unadjusted distances show the genetic distinctiveness of the Travellers. After adjustment for the expected effects of genetic drift, the Travellers are equidistant from the other Irish samples, showing their Irish origins and population history. The observed genetic differences are thus a reflection of genetic drift, and there is no evidence of any external gene flow.

  5. In-Drift Microbial Communities

    SciTech Connect

    D. Jolley

    2000-11-09

    As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses.

  6. SAA drift:experimental results

    NASA Astrophysics Data System (ADS)

    Grigoryan, O. R.; Kudela, K.; Romashova, V. V.; Drozdov, A. Yu.

    According to the paleomagnetic analysis there are variations of Earth's magnetic field connected with magnetic momentum changing. Besides these variations affects on the trapped belt South Atlantic Anomaly (SAA) location. Indeed different observations including Space Shuttle short-time flights approved the existence SAA westward drift with speed 0.1-1.0 (deg/year) and northward drift with speed approximately 0.1 (deg/year). In this work we present the analysis of experimental results obtained in SINP MSU in 1972-2003 from different satellites. There were analyzed the fluxes of protons with energy > 50 MeV, gamma quanta with energy > 500 keV and neutrons with energy 0.1-1.0 MeV in SAA area and their maxima location. The data about fluxes were obtained onboard the orbital stations ``Salut-6'' (1979), MIR (1991, 1998) and ISS (2003) by the identical experimental equipment. The comparison of the data obtained during these two decades of investigations confirms the fact of the SAA westward drift. Moreover the same analysis of maximum flux location of electrons with hundreds keV energy (satellites ``Kosmos-484'' (1972), ``Interkosmos-17'' (1977) and ``Activny'' (``Interkosmos-24'', 1991)) confirmed not only the SAA westward drift but northward drift also.

  7. [Study of spectrum drifting of primary colors and its impact on color rendering properties].

    PubMed

    Cui, Xiao-yan; Zhang, Xiao-dong

    2012-08-01

    LEDs are currently used widely to display text, graphics and images in large screens. With red, green and blue LEDs as three primary colors, color rendition will be realized through color mixing. However, LEDs' spectrum will produce drifts with the changes in the temperature environment. With the changes in the driving current simulating changes in the temperature, the three primary color LEDs' spectral drifts were tested, and the drift characteristics of the three primary colors were obtained respectively. Based on the typical characteristics of the LEDs and the differences between LEDs with different colors in composition and molecular structure, the paper analyzed the reason for the spectrum drifts and the drift characteristics of different color LEDs, and proposed the equations of spectrum drifts. Putting the experimental data into the spectrum drift equations, the paper analyzed the impacts of primary colors on the mixed color, pointed out a way to reduce the chromatic aberration, and provided the theory for engineering application of color LEDs.

  8. An Investigation of How the Channel of Input and Access to Test Questions Affect L2 Listening Test Performance

    ERIC Educational Resources Information Center

    Wagner, Elvis

    2013-01-01

    The use of video technology has become widespread in the teaching and testing of second-language (L2) listening, yet research into how this technology affects the learning and testing process has lagged. The current study investigated how the channel of input (audiovisual vs. audio-only) used on an L2 listening test affected test-taker…

  9. A clearing house for diagnostic testing: the solution to ensure access to and use of patented genetic inventions?

    PubMed Central

    van Zimmeren, Esther; Verbeure, Birgit; Matthijs, Gert; Van Overwalle, Geertrui

    2006-01-01

    In genetic diagnostics, the emergence of a so-called "patent thicket" is imminent. Such an overlapping set of patent rights may have restrictive effects on further research and development of diagnostic tests, and the provision of clinical diagnostic services. Currently, two models that may facilitate access to and use of patented genetic inventions are attracting much debate in various national and international fora: patent pools and clearing houses. In this article, we explore the concept of clearing houses. Several types of clearing houses are identified. First, we describe and discuss two types that would provide access to information on the patented inventions: the information clearing house and the technology exchange clearing house. Second, three types of clearing houses are analysed that not only offer access to information but also provide an instrument to facilitate the use of the patented inventions: the open access clearing house, the standardized licences clearing house and the royalty collection clearing house. A royalty collection clearing house for genetic diagnostic testing would be the most comprehensive as it would serve several functions: identifying patents and patent claims essential to diagnostic testing, matching licensees with licensors, developing and supplying standardized licences, collecting royalties, monitoring whether users respect licensing conditions, and providing dispute resolution services such as mediation and arbitration. In this way, it might function as an effective model for users to facilitate access to and use of the patented inventions. However, it remains to be seen whether patent holders with a strong patent portfolio will be convinced by the advantages of the royalty collection clearing house and be willing to participate. PMID:16710543

  10. Incremental learning of concept drift in nonstationary environments.

    PubMed

    Elwell, Ryan; Polikar, Robi

    2011-10-01

    We introduce an ensemble of classifiers-based approach for incremental learning of concept drift, characterized by nonstationary environments (NSEs), where the underlying data distributions change over time. The proposed algorithm, named Learn(++). NSE, learns from consecutive batches of data without making any assumptions on the nature or rate of drift; it can learn from such environments that experience constant or variable rate of drift, addition or deletion of concept classes, as well as cyclical drift. The algorithm learns incrementally, as other members of the Learn(++) family of algorithms, that is, without requiring access to previously seen data. Learn(++). NSE trains one new classifier for each batch of data it receives, and combines these classifiers using a dynamically weighted majority voting. The novelty of the approach is in determining the voting weights, based on each classifier's time-adjusted accuracy on current and past environments. This approach allows the algorithm to recognize, and act accordingly, to the changes in underlying data distributions, as well as to a possible reoccurrence of an earlier distribution. We evaluate the algorithm on several synthetic datasets designed to simulate a variety of nonstationary environments, as well as a real-world weather prediction dataset. Comparisons with several other approaches are also included. Results indicate that Learn(++). NSE can track the changing environments very closely, regardless of the type of concept drift. To allow future use, comparison and benchmarking by interested researchers, we also release our data used in this paper.

  11. Classroom Use of Test Accommodations: Issues of Access, Equity, and Conflation

    ERIC Educational Resources Information Center

    Schissel, Jamie L.

    2014-01-01

    Test accommodations are changes to test administration, responses, or the test itself that are offered to emergent bilingual students for standardized tests and also for classroom assessments in some states in the USA. Currently there is a lack of research examining the use of test accommodations as a pedagogical practice. This paper presents a…

  12. Wages and Unequal Access to Organizational Power: An Empirical Test of Gender Discrimination.

    ERIC Educational Resources Information Center

    Hultin, Mia; Szulkin, Ryszard

    1999-01-01

    A study of Swedish workers investigated whether earnings are affected by the gender composition of firms' managerial staff. Gender-differentiated access to organizational power structures proved essential to explaining women's relatively low wages. Women working in male-dominated establishments had lower wages than firms with more women managers.…

  13. Design and testing of access-tube TDR soil water sensor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed the design of a waveguide on the exterior of an access tube for use in time-domain reflectometry (TDR) for in-situ soil water content sensing. In order to optimize the design with respect to sampling volume and losses, we derived the electromagnetic (EM) fields produced by a TDR sensor...

  14. Testing an Asset-Building Approach for Young People: Early Access to Savings Predicts Later Savings

    ERIC Educational Resources Information Center

    Friedline, Terri; Elliott, William; Chowa, Gina A. N.

    2013-01-01

    A major hypothesis of asset-building is that early access to savings accounts leads to continued and improved educational and economic outcomes over time. This study asks whether or not young adults (ages 18-22) in 2007, particularly among lower income households, are significantly more likely to own savings accounts and to accumulate more savings…

  15. Better Tests, Fewer Barriers: Advances in Accessibility through PARCC and Smarter Balanced

    ERIC Educational Resources Information Center

    Batel, Samantha; Sargrad, Scott

    2016-01-01

    New assessments aligned to college- and career-ready standards are a major step forward in accessibility and accommodation features for students with disabilities and English language learners. Designed by two consortia of states--the Partnership for Assessment of Readiness for College and Careers, or PARCC, and the Smarter Balanced Assessment…

  16. Beyond the Test Score: A Mixed Methods Analysis of a College Access Intervention in Chile

    ERIC Educational Resources Information Center

    Treviño, Ernesto; Scheele, Judith; Flores, Stella M.

    2014-01-01

    Using both quantitative and qualitative analyses, we examine the role of a college access intervention in the enrollment and persistence outcomes of low-income students in Chile modeled partially after a Texas admissions program. We find that, although students from the program have a mean cumulative GPA significantly lower than that of their…

  17. Redshift drift exploration for interacting dark energy

    NASA Astrophysics Data System (ADS)

    Geng, Jia-Jia; Li, Yun-He; Zhang, Jing-Fei; Zhang, Xin

    2015-08-01

    By detecting redshift drift in the spectra of the Lyman- forest of distant quasars, the Sandage-Loeb (SL) test directly measures the expansion of the universe, covering the "redshift desert" of . Thus this method is definitely an important supplement to the other geometric measurements and will play a crucial role in cosmological constraints. In this paper, we quantify the ability of the SL test signal by a CODEX-like spectrograph for constraining interacting dark energy. Four typical interacting dark energy models are considered: (i) , (ii) , (iii) , and (iv) . The results show that for all the considered interacting dark energy models, relative to the current joint SN BAO CMB observations, the constraints on and would be improved by about 60 and 30-40 %, while the constraints on w and would be slightly improved, with a 30-year observation of the SL test. We also explore the impact of the SL test on future joint geometric observations. In this analysis, we take the model with as an example, and we simulate future SN and BAO data based on the space-based project WFIRST. We find that with the future geometric constraints, the redshift drift observations would help break the geometric degeneracies in a meaningful way, thus the measurement precisions of , , w, and could be substantially improved using future probes.

  18. Access to syringes for HIV prevention for injection drug users in St. Petersburg, Russia: syringe purchase test study

    PubMed Central

    2013-01-01

    Background The HIV epidemic in Russia is concentrated among injection drug users (IDUs). This is especially true for St. Petersburg where high HIV incidence persists among the city’s estimated 80,000 IDUs. Although sterile syringes are legally available, access for IDUs may be hampered. To explore the feasibility of using pharmacies to expand syringe access and provide other prevention services to IDUs, we investigated the current access to sterile syringes at the pharmacies and the correlation between pharmacy density and HIV prevalence in St. Petersburg. Methods 965 pharmacies citywide were mapped, classified by ownership type, and the association between pharmacy density and HIV prevalence at the district level was tested. We selected two districts among the 18 districts – one central and one peripheral – that represented two major types of city districts and contacted all operating pharmacies by phone to inquire if they stocked syringes and obtained details about their stock. Qualitative interviews with 26 IDUs provided data regarding syringe access in pharmacies and were used to formulate hypotheses for the pharmacy syringe purchase test wherein research staff attempted to purchase syringes in all pharmacies in the two districts. Results No correlation was found between the density of pharmacies and HIV prevalence at the district level. Of 108 operating pharmacies, 38 (35%) did not sell syringes of the types used by IDUs; of these, half stocked but refused to sell syringes to research staff, and the other half did not stock syringes at all. Overall 70 (65%) of the pharmacies did sell syringes; of these, 49 pharmacies sold single syringes without any restrictions and 21 offered packages of ten. Conclusions Trainings for pharmacists need to be conducted to reduce negative attitudes towards IDUs and increase pharmacists’ willingness to sell syringes. At a structural level, access to safe injection supplies for IDUs could be increased by including syringes

  19. Effects of freely accessible computerized test systems on the spontaneous behaviors and stress level of Guinea baboons (Papio papio).

    PubMed

    Fagot, Joël; Gullstrand, Julie; Kemp, Caralyn; Defilles, Céline; Mekaouche, Mourad

    2014-01-01

    Fagot and Paleressompoulle [Fagot and Paleressompoulle (2009) Behav Res Methods 41: 396-404] described a new automated learning device for monkeys (ALDM) to test the cognitive functions of nonhuman primates within their social groups. However, the impact of the ALDM procedure on animal well-being needs to be investigated. The present study assessed the consequences of ALDM testing on the behavioral repertoire of Guinea baboons (Papio papio) and their stress levels as inferred from measurements of saliva cortisol. Accessibility to ALDM test computers reduced the number of resting periods as well as the number of stereotypies. Lower cortisol levels were also found during ALDM testing. These findings and others demonstrate that ALDM testing has a positive impact on animal well-being and can be considered as a means for behavioral enrichment in captive primates.

  20. Measurement of Spray Drift with a Specifically Designed Lidar System.

    PubMed

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R

    2016-04-08

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R² > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift.

  1. Measurement of Spray Drift with a Specifically Designed Lidar System

    PubMed Central

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R.

    2016-01-01

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R2 > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift. PMID:27070613

  2. An Alcohol Test for Drifting Constants

    NASA Astrophysics Data System (ADS)

    Jansen, P.; Bagdonaite, J.; Ubachs, W.; Bethlem, H. L.; Kleiner, I.; Xu, L.-H.

    2013-06-01

    The Standard Model of physics is built on the fundamental constants of nature, however without providing an explanation for their values, nor requiring their constancy over space and time. Molecular spectroscopy can address this issue. Recently, we found that microwave transitions in methanol are extremely sensitive to a variation of the proton-to-electron mass ratio μ, due to a fortuitous interplay between classically forbidden internal rotation and rotation of the molecule as a whole. In this talk, we will explain the origin of this effect and how the sensitivity coefficients in methanol are calculated. In addition, we set a limit on a possible cosmological variation of μ by comparing transitions in methanol observed in the early Universe with those measured in the laboratory. Based on radio-astronomical observations of PKS1830-211, we deduce a constraint of Δμ/μ=(0.0± 1.0)× 10^{-7} at redshift z = 0.89, corresponding to a look-back time of 7 billion years. While this limit is more constraining and systematically more robust than previous ones, the methanol method opens a new search territory for probing μ-variation on cosmological timescales. P. Jansen, L.-H. Xu, I. Kleiner, W. Ubachs, and H.L. Bethlem Phys. Rev. Lett. {106}(100801) 2011. J. Bagdonaite, P. Jansen, C. Henkel, H.L. Bethlem, K.M. Menten, and W. Ubachs Science {339}(46) 2013.

  3. Test Report for the Direct Access Radar/National Airspace System (DARC/NAS) Bi-Directional Interface Test

    DTIC Science & Technology

    1989-01-01

    Report m. Robert V. DiMeo, et al. DOT/FAA/CT-TN89/ II 9. Performing Organisation Name and Addrtess 10. Work Unit No. (TRAIS) U.S. Department of...procedures in summary form, the test enviroment , and test administration, data collection, and analyses. - Results - Presents significant findings based...cases that did not pass, whi wre attributed to S4 timng problems. As stated earlier in the Test Enviroent section we expected that a small percntage of

  4. Sensor Drift Compensation Algorithm based on PDF Distance Minimization

    NASA Astrophysics Data System (ADS)

    Kim, Namyong; Byun, Hyung-Gi; Persaud, Krishna C.; Huh, Jeung-Soo

    2009-05-01

    In this paper, a new unsupervised classification algorithm is introduced for the compensation of sensor drift effects of the odor sensing system using a conducting polymer sensor array. The proposed method continues updating adaptive Radial Basis Function Network (RBFN) weights in the testing phase based on minimizing Euclidian Distance between two Probability Density Functions (PDFs) of a set of training phase output data and another set of testing phase output data. The output in the testing phase using the fixed weights of the RBFN are significantly dispersed and shifted from each target value due mostly to sensor drift effect. In the experimental results, the output data by the proposed methods are observed to be concentrated closer again to their own target values significantly. This indicates that the proposed method can be effectively applied to improved odor sensing system equipped with the capability of sensor drift effect compensation

  5. Forecast of iceberg ensemble drift

    SciTech Connect

    El-Tahan, M.S.; El-Tahan, H.W.; Venkatesh, S.

    1983-05-01

    The objectives of the study are to gain a better understanding of the characteristics of iceberg motion and the factors controlling iceberg drift, and to develop an iceberg ensemble drift forecast system to be operated by the Canadian Atmospheric Environment Service. An extensive review of field and theoretical studies on iceberg behaviour, and the factors controlling iceberg motion has been carried out. Long term and short term behaviour of icebergs are critically examined. A quantitative assessment of the effects of the factors controlling iceberg motion is presented. The study indicated that wind and currents are the primary driving forces. Coriolis Force and ocean surface slope also have significant effects. As for waves, only the higher waves have a significant effect. Iceberg drift is also affected by iceberg size characteristics. Based on the findings of the study a comprehensive computerized forecast system to predict the drift of iceberg ensembles off Canada's east coast has been designed. The expected accuracy of the forecast system is discussed and recommendations are made for future improvements to the system.

  6. Drift Hamiltonian in magnetic coordinates

    SciTech Connect

    White, R.B.; Boozer, A.H.; Hay, R.

    1982-02-01

    A Hamiltonian formulation of the guiding-center drift in arbitrary, steady state, magnetic and electric fields is given. The canonical variables of this formulation are simply related to the magnetic coordinates. The modifications required to treat ergodic magnetic fields using magnetic coordinates are explicitly given in the Hamiltonian formulation.

  7. High Stakes Testing and Teacher Access to Professional Opportunities: Lessons from Indonesia

    ERIC Educational Resources Information Center

    Ashadi, Ashadi; Rice, Suzanne

    2016-01-01

    High-stakes testing regimes, in which schools are judged on their capacity to attain high student results in national tests, are becoming common in both developed and developing nations, including the United States, Britain and Australia. However, while there has been substantial investigation around the impact of high-stakes testing on curriculum…

  8. Inoculation against Forgetting: Advantages of Immediate versus Delayed Initial Testing Due to Superior Verbatim Accessibility

    ERIC Educational Resources Information Center

    Pansky, Ainat

    2012-01-01

    In this study, potential benefits of early memory testing were examined in terms of "inoculating" eyewitness memory against forgetting. As predicted by fuzzy trace theory (e.g., Reyna & Titcomb, 1997), a larger testing advantage in the delayed recall of event details was expected after immediate testing than after delayed testing…

  9. The Role of Testing in Institutional Selectivity and Black Access to Higher Education.

    ERIC Educational Resources Information Center

    Morris, Lorenzo

    Student distribution among institutions of higher education corresponds more to the socioeconomic status of institutions than to the test-predicted performance levels. Aggregate data shows that the more costly institutions recruit wealthier students with higher test scores. Traditionally black institutions rely far less on test results, preferring…

  10. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Sonnenthale

    2001-04-16

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) 2000 [1534471]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M&O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: Performance Assessment (PA); Near-Field Environment (NFE) PMR; Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); and UZ Flow and Transport Process Model Report (PMR). The work scope for this activity is presented in the TWPs cited above, and summarized as follows: Continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in this AMR are required

  11. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Gonnenthal; N. Spyoher

    2001-02-05

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) 2000 [153447]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M and O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: (1) Performance Assessment (PA); (2) Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); (3) UZ Flow and Transport Process Model Report (PMR); and (4) Near-Field Environment (NFE) PMR. The work scope for this activity is presented in the TWPs cited above, and summarized as follows: continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in

  12. Impact of gene patents and licensing practices on access to genetic testing for hearing loss.

    PubMed

    Chandrasekharan, Subhashini; Fiffer, Melissa

    2010-04-01

    Genetic testing for heritable hearing loss involves a mix of patented and unpatented genes, mutations and testing methods. More than half of all hearing loss is linked to inherited mutations, and five genes are most commonly tested for in the United States. There are no patents on three of these genes, but Athena Diagnostics holds exclusive licenses to test for a common mutation in the GJB2 gene associated with about 50% of all cases as well as mutations in the MTRNR1 gene. This fragmented intellectual property landscape made hearing loss a useful case study to assess whether patent rights in genetic testing can proliferate or overlap, and whether it is possible to gather the rights necessary to perform testing. Testing for hearing loss is widely available, primarily from academic medical centers. Based on literature reviews and interviews with researchers, research on the genetics of hearing loss has generally not been impeded by patents. There is no consistent evidence of a premium in testing prices attributable to patent status. Athena Diagnostics has, however, used its intellectual property to discourage other providers from offering some tests. There is no definitive answer about the suitability of current patenting and licensing of commonly tested genes because of continuing legal uncertainty about the extent of enforcement of patent rights. Clinicians have also expressed concerns that multiplex tests will be difficult to develop because of overlapping intellectual property and conflict with Athena's sole provider business model.

  13. Evolution: drift will tear us apart.

    PubMed

    Maderspacher, Florian

    2012-11-06

    That the widely scattered geographical distribution of some animals could be due to continental drift is a neat idea. Now, cave animals provide evidence for extreme long-term persistence on continents drifting apart.

  14. Can the HIV home test promote access to care? Lessons learned from the in-home pregnancy test.

    PubMed

    Schnall, Rebecca; Carballo-Diéguez, Alex; Larson, Elaine

    2014-12-01

    Adolescents and young adults are the fastest growing age group of human immunodeficiency virus (HIV) positive individuals in the US, and many who are infected do not know their HIV status. The HIV home test has the potential to help curb the HIV epidemic by improving detection of persons living with HIV and enabling them to seek follow-up care but it has not yet been evaluated in adolescents. Analogous to the home pregnancy test, which was met with much resistance and only successfully marketed during a time of social change, the HIV home test has been met with resistance since its FDA approval. This commentary summarizes the need to systematically evaluate positive and untoward/unanticipated effects of HIV home testing, particularly in young adults. The overall incidence of HIV has been declining in the US, yet it continues to grow at alarming rates for adolescents and young adults [1]. Almost 40 % of new HIV infections in the US are in this age group [2]. Further, many HIV infected adolescents and young adults are unaware of their infection. Nationwide, only 22.6 % of sexually active high school students have ever been tested for HIV [3]. While advances in drug regimens have transformed HIV into a chronic disease, infected individuals need to be identified and subsequently engaged in care [4].

  15. Diel drift of Chironomidae larvae in a pristine Idaho mountain stream

    USGS Publications Warehouse

    Tilley, L.J.

    1989-01-01

    Simultaneous hourly net collections in a meadow and canyon reach of a mountain stream determined diel and spatial abundances of drifting Chironomidae larvae. Sixty-one taxa were identified to the lowest practical level, 52 in the meadow and 41 in the canyon. Orthocladiinae was the most abundant subfamily with 32 taxa and a 24 h mean density of 294 individuals 100 m-3 (meadow) and 26 taxa and a mean of 648 individuals 100 m-3 (canyon). Chironominae was the second most abundant subfamily. Nonchironomid invertebrates at both sites and total Chironomidae larvae (meadow) were predominantly night-drifting. Parakiefferiella and Psectrocladius were day-drifting (meadow) whereas 8 other chironomid taxa (meadow) and 2 taxa (canyon) were night-drifting. All others were aperiodic or too rare to test periodicity, Stempellinella cf brevis Edwards exhibited catastrophic drift in the canyon only. The different drift patterns between sites is attributed to greater loss of streambed habitat in the canyon compared to the meadow as streamflow decreased. Consequent crowding of chironomid larvae in the canyon caused catastrophic drift or interfered with drift periodicty. This study adds to knowledge of Chironomidae drift and shows influences on drift of hydrologic and geomorphic conditions. ?? 1989 Kluwer Academic Publishers.

  16. Impact of Drift on the Vehicle Liftoff Acoustic Environments

    NASA Technical Reports Server (NTRS)

    Kenny, Jeremy; Giacomoni, Clothilde

    2016-01-01

    During liftoff a vehicle can drift due to wind, nozzle gimbaling, fly away maneuver, etc... This drift can cause the exhaust plumes to impinge on the deck and cause the noise levels experienced by the vehicle to increase. A small increase in the plume impingement can have a dramatic effect on the noise levels when the vehicle is only a few nozzle diameters from the deck. As the vehicle lifts off the deck the increase in noise levels lessens as the plume impingement increases. Several scale model acoustic tests have been undertaken at Marshall Space Flight Center which had test cases that were used to define the relationship between drift and the noise levels experienced by the vehicle.

  17. Making Dry Bones Live: The Role of Testing in Equity and Access.

    ERIC Educational Resources Information Center

    Purnell, Rosentene Bennett

    There is a need for more precise descriptions of the claims to truth of standardized tests, of their interpretive authority, and of the limits of understanding which are reached through their processes. Typically minority students who score poorly on such tests do because their schools fail to connect with them. Pedagogy, therefore, must somehow…

  18. Access to Adequate Healthcare for Hmong Women: A Patient Navigation Program to Increase Pap Test Screening

    PubMed Central

    Lo, Penny; Fang, Dao Moua; Ly, May Ying; Stewart, Susan; Lee, Serge; Chen, Moon S.

    2015-01-01

    This paper describes the development and implementation of a Hmong Cervical Cancer Intervention Program utilizing a patient navigation model to raise cervical cancer awareness for Hmong women through educational workshops and to assist Hmong women in obtaining a Pap test. Out of 402 women who participated in a baseline survey, the Patient Navigation Program was able to enroll 109 participants who had not had a Pap test in the past 3 years and had never had a Pap test. Through utilization of outreach, an awareness campaign and patient navigation support, at least 38 percent of 109 participants obtained a Pap test. Overall, 21 workshops and 43 outreach activities were conducted by the Hmong Women’s Heritage Association, leading to 63 percent of those enrolled in the Patient Navigation Program who could be contacted to obtain a Pap test. PMID:26594134

  19. A Pascalian lateral drift sensor

    NASA Astrophysics Data System (ADS)

    Jansen, H.

    2016-09-01

    A novel concept of a layer-wise produced semiconductor sensor for precise particle tracking is proposed herein. In contrast to common semiconductor sensors, local regions with increased doping concentration deep in the bulk termed charge guides increase the lateral drift of free charges on their way to the read-out electrode. This lateral drift enables charge sharing independent of the incident position of the traversing particle. With a regular grid of charge guides the lateral charge distribution resembles a normalised Pascal's triangle for particles that are stopped in depths lower than the depth of the first layer of the charge guides. For minimum ionising particles a sum of binomial distributions describes the lateral charge distribution. This concept decouples the achievable sensor resolution from the pitch size as the characteristic length is replaced by the lateral distance of the charge guides.

  20. Random drift and culture change.

    PubMed Central

    Bentley, R. Alexander; Hahn, Matthew W.; Shennan, Stephen J.

    2004-01-01

    We show that the frequency distributions of cultural variants, in three different real-world examples--first names, archaeological pottery and applications for technology patents--follow power laws that can be explained by a simple model of random drift. We conclude that cultural and economic choices often reflect a decision process that is value-neutral; this result has far-reaching testable implications for social-science research. PMID:15306315

  1. Actual or potential neighborhood resources and access to them: testing hypotheses of social capital for the health of female caregivers.

    PubMed

    Carpiano, Richard M

    2008-08-01

    This study considers three commonly overlooked aspects of neighborhood social capital: actual or potential network resources, access to such resources, and their potentially negative implications, as they bear on the health of adult female caregivers of children. Drawing upon Bourdieu's social capital theory and urban and community sociology research, two sets of related hypotheses are formulated and tested. The first set examines specific resources that inhere within neighborhood social relations by testing hypotheses concerning four forms of social capital (social support, social leverage, informal social control, and neighborhood organization participation) and their respective associations with daily smoking and perceived health. The second set assesses the importance of one's access to the neighborhood networks that possess such resources by testing hypotheses regarding how residents' neighborhood attachment moderates the association between social capital forms and these health outcomes in positive and negative ways. Analyses of the Los Angeles Family and Neighborhood Survey (L.A.FANS) linked with tract level census data indicate that specific social capital forms were directly associated with positive and negative health outcomes. Neighborhood attachment significantly moderated relationships between several social capital forms and health, indicating that a female caregiver's degree of network integration matters in both health promoting and health damaging ways. In addition to illustrating the utility of a Bourdieusian perspective for formulating explicit, testable hypotheses regarding how social capital may matter for health, these findings suggest that future public health studies of neighborhood social capital need to consider (1) the actual or potential resources that inhere within relationships, and (2) the role of access to such resources for promoting or compromising health.

  2. Widening the Access to HIV Testing: The Contribution of Three In-Pharmacy Testing Programmes in Spain

    PubMed Central

    Fernández-Balbuena, Sonia; Belza, María José; Zulaica, Daniel; Martinez, Jose Luis; Marcos, Henar; Rifá, Benet; Arrillaga, Arantxa; de la Fuente, Luis; Hoyos, Juan

    2015-01-01

    Background and Objective Spain has implemented several in-pharmacy HIV testing programmes performed by pharmacists as part of their everyday routine. We aim to assess the feasibility and the main outcomes of three programmes implemented in three Spanish regions with different sociological profiles and also different epidemiology for HIV. Methods The characteristics of the 24151 people tested between 2009 and 2013 at 74 urban pharmacies are studied. We compare the main outcomes of the programmes with those of each Regional HIV Surveillance System (RHSS) assessing the contribution to the total new diagnosis in each region and if priority groups are being reached. Results 45.7% were heterosexual men (MSW), 14.4% men who have sex with men (MSM), and 27% women. The 35% were younger than 30 and 9.6% foreigners. The 52% were previously untested, and women were the most likely to be untested. The three programmes altogether diagnosed 226 people, resulting in a global prevalence of 0.9% (95%CI: 0.8–1.1); 3.4% in MSM (95%CI: 2.8–4.0). The prevalence among Spaniards was 0.8% (0.7–1.0) vs. 2.2 (1.6–2.9) among foreigners. The percentages of MSM diagnosed by all three programmes were higher than the one reported by their respective RHSS. Thirty four percent of the reactive MSM and the 71.4% of the reactive MSW did not have a previous HIV test although big testing history differences were observed across the programmes. Altogether, these services contributed with the 10.6% of all HIV diagnoses in these regions. Conclusions In-pharmacy HIV testing programmes are a valuable testing option, having been able to uncover 1 out of 10 the new diagnoses reported in each region. They showed a good capacity of reaching and diagnosing previously untested populations, not only a priority population such as MSM but also heterosexual population who are more affected by delayed diagnosis. They seem to be particularly suitable for regions without large cities and specific HIV diagnostic

  3. Impact of Gene Patents and Licensing Practices on Access to Genetic Testing for Long QT Syndrome

    PubMed Central

    Angrist, Misha; Chandrasekharan, Subhashini; Heaney, Christopher; Cook-Deegan, Robert

    2010-01-01

    Genetic testing for Long QT syndrome (LQTS) exemplifies patenting and exclusive licensing with different outcomes at different times. Exclusive licensing from the University of Utah changed the business model from sole provider to two US providers of LQTS testing. LQTS is associated with mutations in many genes, ten of which are now tested by two competing firms in the United States, PGxHealth and GeneDx. Until 2009, PGxHealth was sole provider, based largely on exclusive rights to patents from the University of Utah and other academic institutions. University of Utah patents were initially licensed to DNA Sciences, whose patent rights were acquired by Gennaissance, and then by Clinical Data, Inc., which owns PGxHealth. In 2002, DNA Sciences “cleared the market” by sending cease and desist patent enforcement letters to university and reference laboratories offering LQTS genetic testing. There was no test on the market for a one- to two-year period. From 2005-2008, most LQTS-related patents were controlled by Clinical Data, Inc., and its subsidiary PGxHealth. BioReference Laboratories, Inc., secured countervailing exclusive patent rights starting in 2006, also from the University of Utah, and broke the PGxHealth monopoly in early 2009, creating a duopoly for genetic testing in the United States, and expanding the number of genes for which commercial testing is available from five to ten. PMID:20393304

  4. Abstraction of Seepage into Drifts

    SciTech Connect

    M.L. Wilson; C.K. Ho

    2000-09-26

    A total-system performance assessment (TSPA) for a potential nuclear-waste repository requires an estimate of the amount of water that might contact waste. This paper describes the model used for part of that estimation in a recent TSPA for the Yucca Mountain site. The discussion is limited to estimation of how much water might enter emplacement drifts; additional considerations related to flow within the drifts, and how much water might actually contact waste, are not addressed here. The unsaturated zone at Yucca Mountain is being considered for the potential repository, and a drift opening in unsaturated rock tends to act as a capillary barrier and divert much of the percolating water around it. For TSPA, the important questions regarding seepage are how many waste packages might be subjected to water flow and how much flow those packages might see. Because of heterogeneity of the rock and uncertainty about the future (how the climate will evolve, etc.), it is not possible to predict seepage amounts or locations with certainty. Thus, seepage is treated as a stochastic quantity in TSPA simulations, with the magnitude and spatial distribution of seepage sampled from uncertainty distributions. The distillation of the essential components of process modeling into a form suitable for use in TSPA simulations is referred to as abstraction. In the following sections, seepage process models and abstractions will be summarized and then some illustrative results are presented.

  5. Ionospheric Plasma Drift Analysis Technique Based On Ray Tracing

    NASA Astrophysics Data System (ADS)

    Ari, Gizem; Toker, Cenk

    2016-07-01

    Ionospheric drift measurements provide important information about the variability in the ionosphere, which can be used to quantify ionospheric disturbances caused by natural phenomena such as solar, geomagnetic, gravitational and seismic activities. One of the prominent ways for drift measurement depends on instrumentation based measurements, e.g. using an ionosonde. The drift estimation of an ionosonde depends on measuring the Doppler shift on the received signal, where the main cause of Doppler shift is the change in the length of the propagation path of the signal between the transmitter and the receiver. Unfortunately, ionosondes are expensive devices and their installation and maintenance require special care. Furthermore, the ionosonde network over the world or even Europe is not dense enough to obtain a global or continental drift map. In order to overcome the difficulties related to an ionosonde, we propose a technique to perform ionospheric drift estimation based on ray tracing. First, a two dimensional TEC map is constructed by using the IONOLAB-MAP tool which spatially interpolates the VTEC estimates obtained from the EUREF CORS network. Next, a three dimensional electron density profile is generated by inputting the TEC estimates to the IRI-2015 model. Eventually, a close-to-real situation electron density profile is obtained in which ray tracing can be performed. These profiles can be constructed periodically with a period of as low as 30 seconds. By processing two consequent snapshots together and calculating the propagation paths, we estimate the drift measurements over any coordinate of concern. We test our technique by comparing the results to the drift measurements taken at the DPS ionosonde at Pruhonice, Czech Republic. This study is supported by TUBITAK 115E915 and Joint TUBITAK 114E092 and AS CR14/001 projects.

  6. Grain Size of the North-Atlantic Drifts Sediments: is the Gloria Drift a Contourite Drift?

    NASA Astrophysics Data System (ADS)

    Dorokhova, E.; Sivkov, V.; Bashirova, L.

    2015-12-01

    Mean size of mineral particles of 10-63 fraction, so-called sortable silt mean size (SS) (McCave, 1995) and modes of grain-size distribution were used as proxies for reconstruction of paleocurrents intensity variations in the North Atlantic. It was assumed that the first mode (3-8 μm) is formed as the result of normal pelagic sedimentation and the second mode (10-30 μm) appears under the bottom currents influence. The sediments with bimodal grain-size distribution (the second mode varies from 10 to 28 μm) correlate with increased SS (up to 18-23 μm) in the Hatton and Snorry Drifts, indicating an increase in contour currents intensity during MIS 1, 3 and 5e. In contrast, there are no any relationships between grain size distribution (high SS values, appearance of bimodal distributions) and climatic cyclicity of variations in contour currents intensity at the Gloria Drift. Moreover, the Gloria Drift sediments differ from the contourite sediments of the Snorry and Hatton Drifts by shifting of the second mode toward the coarse particles (25-40 μm), higher sedimentation rates and higher IRD content. This evidence puts in doubt the contourite origin of the Gloria Drift. At the same time, we have identified the similarity between the Gloria Drift sediments and IRD-containing hemiturbidites of Labrador Sea (Hesse and Khodabakhsh, 2006). Fine-grained sediment lofting has been inferred for ice marginal regions of the northwest Labrador Sea. Sediment failure on the Labrador Slope predominantly produces muddy turbidity currents, because the slope sediments are mud-dominated. Their deposits are the indicative muddy spill-over turbidites of the NAMOC levees and the levees of the tributaries to the NAMOC. Dispersal of the IRD throughout the graded mud layers is evidence that the two processes, ice rafting and the delivery of the fines by lofting, occurred simultaneously. This work was supported by Russian Scientific Fund (grant No. 14-50-00095).

  7. Exploring the Relationship between Access Technology and Standardized Test Scores for Youths with Visual Impairments: Secondary Analysis of the National Longitudinal Transition Study 2

    ERIC Educational Resources Information Center

    Freeland, Amy L.; Emerson, Robert Wall; Curtis, Amy B.; Fogarty, Kieran

    2010-01-01

    This article presents the findings of a secondary analysis of the National Longitudinal Transition Study 2 that explored the predictive association between training in access technology and performance on the Woodcock-Johnson Tests of Academic Achievement: III. The results indicated that the use of access technology had a limited predictive…

  8. Impact of gene patents and licensing practices on access to genetic testing for Alzheimer disease.

    PubMed

    Skeehan, Katie; Heaney, Christopher; Cook-Deegan, Robert

    2010-04-01

    Genetic testing for Alzheimer disease includes genotyping for apolipoprotein E, for late-onset Alzheimer disease, and three rare autosomal dominant, early-onset forms of Alzheimer disease associated with different genes (APP, PSEN1, and PSEN2). According to researchers, patents have not impeded research in the field, nor were patents an important consideration in the quest for the genetic risk factors. Athena Diagnostics holds exclusive licenses from Duke University for three "method" patents covering apolipoprotein E genetic testing. Athena offers tests for apolipoprotein E and genes associated with early-onset, autosomal-dominant Alzheimer disease. One of those presenilin genes is patented and exclusively licensed to Athena; the other presenilin gene was patented but the patent was allowed to lapse; and one (amyloid precursor protein) is patented as a research tool. Direct-to-consumer testing is available for some Alzheimer disease-related genes, apparently without a license. Athena Diagnostics consolidated its position in the market for Alzheimer disease genetic testing by collecting exclusive rights to patents arising from university research. Duke University also used its licenses to Athena to enforce adherence to clinical guidelines, including elimination of the service from Smart Genetics, which was offering direct-to-consumer risk assessment based on apolipoprotein E genotyping.

  9. Evaluating Retailer Behavior in Preventing Youth Access to Harmful Legal Products: A Feasibility Test*

    PubMed Central

    Courser, Matthew W.; Holder, Harold D.; Collins, David; Johnson, Knowlton; Ogilvie, Kristen A.

    2008-01-01

    This paper reports results from a feasibility study of a community effort to reduce the availability of legal products that youth can use to get “high”. The study evaluated the potential of youth purchase attempts to detect actual changes in retail availability of harmful legal products. These results were triangulated with self-reports from retailers themselves about their own policies and practices. Before the intervention less than half of retailers reported using any of six possible strategies identified as ways to reduce youth access to harmful products and less than 7% of baseline youth attempts to purchase potentially harmful legal products were refused or questioned. After the low dosage intervention, retailers reported increased use of three strategies and a statistically significant increase in the percentage of purchase attempts that were either questioned or refused by retail clerks. These findings (1) demonstrate the potential feasibility of retailer focused environmental strategies and (2) support continued use of youth purchase attempts as a measure of actual retailer behavior. PMID:18660467

  10. Information access in a dual-task context: testing a model of optimal strategy selection

    NASA Technical Reports Server (NTRS)

    Wickens, C. D.; Seidler, K. S.

    1997-01-01

    Pilots were required to access information from a hierarchical aviation database by navigating under single-task conditions (Experiment 1) and when this task was time-shared with an altitude-monitoring task of varying bandwidth and priority (Experiment 2). In dual-task conditions, pilots had 2 viewports available, 1 always used for the information task and the other to be allocated to either task. Dual-task strategy, inferred from the decision of which task to allocate to the 2nd viewport, revealed that allocation was generally biased in favor of the monitoring task and was only partly sensitive to the difficulty of the 2 tasks and their relative priorities. Some dominant sources of navigational difficulties failed to adaptively influence selection strategy. The implications of the results are to provide tools for jumping to the top of the database, to provide 2 viewports into the common database, and to provide training as to the optimum viewport management strategy in a multitask environment.

  11. Scroll wave drift along steps, troughs, and corners

    NASA Astrophysics Data System (ADS)

    Ke, Hua; Zhang, Zhihui; Steinbock, Oliver

    2015-06-01

    Three-dimensional excitable systems can create nonlinear scroll waves that rotate around one-dimensional phase singularities. Recent theoretical work predicts that these filaments drift along step-like height variations. Here, we test this prediction using experiments with thin layers of the Belousov-Zhabotinsky reaction. We observe that over short distances scroll waves are attracted towards the step and then rapidly commence a steady drift along the step line. The translating filaments always reside on the shallow side of the step near the edge. Accordingly, filaments in the deep domain initially collide with and shorten at the step wall. The drift speeds obey the predicted proportional dependence on the logarithm of the height ratio and the direction depends on the vortex chirality. We also observe drift along the perimeter of rectangular plateaus and find that the filaments perform sharp turns at the corners. In addition, we investigate rectangular troughs for which vortices of equal chirality can drift in different directions. The latter two effects are reproduced in numerical simulations with the Barkley model. The simulations show that narrow troughs instigate scroll wave encounters that induce repulsive interaction and symmetry breaking. Similar phenomena could exist in the geometrically complicated ventricles of the human heart where reentrant vortex waves cause tachycardia and fibrillation.

  12. Evaluation of spray drift from backpack and UTV spraying

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of these tests was to evaluate pesticide drift from ground applications using a standard manual pump backpack sprayer and a UTV-mounted boomless sprayer. Three deposition sampler types were deployed: Mylar cards, water-sensitive papers, and artificial foliage. This study indicates that...

  13. Improving Access to Malaria Rapid Diagnostic Test in Niger State, Nigeria: An Assessment of Implementation up to 2013

    PubMed Central

    Awoleye, Olatunji Joshua; Thron, Chris

    2016-01-01

    Nigeria's 2009–2013 malaria strategic plan adopted WHO diagnosis and treatment guidelines, which include the use of rapid diagnostic tests (RDTs) prior to prescribing treatment with artemisinin combination therapies (ACTs). The current study explores accessibility barriers to the use of RDTs in Niger State and makes recommendations for improving the uptake of RDTs. The study employs literature review, review of data from the Niger State Health Management Information System for January–October 2013, and application of Peters' conceptual framework for assessing access to health services. Data showed that 27 percent of public health facilities (HFs) implemented RDTs, with the aid of donor funds. In these facilities, 77 percent of fever cases presented during the study period were tested with RDTs; 53 percent of fever cases were confirmed cases of malaria, while 60 percent of fever cases were treated. Stockouts of RDTs were a major constraint, and severe fever tended to trigger presumptive treatment. We conclude that although implementation of RDTs led to a reduction in the use of ACTs at HFs, more substantial reduction could be achieved if the state government directed more resources towards the acquisition of RDTs as well as raising the level of awareness of potential users. PMID:27042376

  14. Standardizing Interfaces for External Access to Data and Processing for the NASA Ozone Product Evaluation and Test Element (PEATE)

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt A.; Fleig, Albert J.

    2008-01-01

    NASA's traditional science data processing systems have focused on specific missions, and providing data access, processing and services to the funded science teams of those specific missions. Recently NASA has been modifying this stance, changing the focus from Missions to Measurements. Where a specific Mission has a discrete beginning and end, the Measurement considers long term data continuity across multiple missions. Total Column Ozone, a critical measurement of atmospheric composition, has been monitored for'decades on a series of Total Ozone Mapping Spectrometer (TOMS) instruments. Some important European missions also monitor ozone, including the Global Ozone Monitoring Experiment (GOME) and SCIAMACHY. With the U.S.IEuropean cooperative launch of the Dutch Ozone Monitoring Instrument (OMI) on NASA Aura satellite, and the GOME-2 instrumental on MetOp, the ozone monitoring record has been further extended. In conjunction with the U.S. Department of Defense (DoD) and the National Oceanic and Atmospheric Administration (NOAA), NASA is now preparing to evaluate data and algorithms for the next generation Ozone Mapping and Profiler Suite (OMPS) which will launch on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) in 2010. NASA is constructing the Science Data Segment (SDS) which is comprised of several elements to evaluate the various NPP data products and algorithms. The NPP SDS Ozone Product Evaluation and Test Element (PEATE) will build on the heritage of the TOMS and OM1 mission based processing systems. The overall measurement based system that will encompass these efforts is the Atmospheric Composition Processing System (ACPS). We have extended the system to include access to publically available data sets from other instruments where feasible, including non-NASA missions as appropriate. The heritage system was largely monolithic providing a very controlled processing flow from data.ingest of

  15. Precipitates/Salts Model Calculations for Various Drift Temperature Environments

    SciTech Connect

    P. Marnier

    2001-12-20

    The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b).

  16. Test Scores, Class Rank and College Performance: Lessons for Broadening Access and Promoting Success.

    PubMed

    Niu, Sunny X; Tienda, Marta

    2012-04-01

    Using administrative data for five Texas universities that differ in selectivity, this study evaluates the relative influence of two key indicators for college success-high school class rank and standardized tests. Empirical results show that class rank is the superior predictor of college performance and that test score advantages do not insulate lower ranked students from academic underperformance. Using the UT-Austin campus as a test case, we conduct a simulation to evaluate the consequences of capping students admitted automatically using both achievement metrics. We find that using class rank to cap the number of students eligible for automatic admission would have roughly uniform impacts across high schools, but imposing a minimum test score threshold on all students would have highly unequal consequences by greatly reduce the admission eligibility of the highest performing students who attend poor high schools while not jeopardizing admissibility of students who attend affluent high schools. We discuss the implications of the Texas admissions experiment for higher education in Europe.

  17. Test Scores, Class Rank and College Performance: Lessons for Broadening Access and Promoting Success

    PubMed Central

    Niu, Sunny X.; Tienda, Marta

    2012-01-01

    Using administrative data for five Texas universities that differ in selectivity, this study evaluates the relative influence of two key indicators for college success—high school class rank and standardized tests. Empirical results show that class rank is the superior predictor of college performance and that test score advantages do not insulate lower ranked students from academic underperformance. Using the UT-Austin campus as a test case, we conduct a simulation to evaluate the consequences of capping students admitted automatically using both achievement metrics. We find that using class rank to cap the number of students eligible for automatic admission would have roughly uniform impacts across high schools, but imposing a minimum test score threshold on all students would have highly unequal consequences by greatly reduce the admission eligibility of the highest performing students who attend poor high schools while not jeopardizing admissibility of students who attend affluent high schools. We discuss the implications of the Texas admissions experiment for higher education in Europe. PMID:23788828

  18. Minority Versus Majority Group Performance on an Aptitude Test Battery. Project Access Research Report No. 3.

    ERIC Educational Resources Information Center

    Flaugher, Ronald L.

    Black students from two cities and Mexican-American students, both male and female, showed small but consistent tendencies to perform better, relative to White groups, on three nontraditional measures: tests of inductive reasoning, spatial scanning, and associative memory. These measures showed somewhat less discrepancy between the groups than did…

  19. HIV Risk Behavior and Access to Services: What Predicts HIV Testing among Heterosexually Active Homeless Men?

    ERIC Educational Resources Information Center

    Wenzel, Suzanne L.; Rhoades, Harmony; Tucker, Joan S.; Golinelli, Daniela; Kennedy, David P.; Zhou, Annie; Ewing, Brett

    2012-01-01

    HIV is a serious epidemic among homeless persons, where rates of infection are estimated to be three times higher than in the general population. HIV testing is an effective tool for reducing HIV transmission and for combating poor HIV/AIDS health outcomes that disproportionately affect homeless persons, however, little is known about the HIV…

  20. Spiral biasing adaptor for use in Si drift detectors and Si drift detector arrays

    DOEpatents

    Li, Zheng; Chen, Wei

    2016-07-05

    A drift detector array, preferably a silicon drift detector (SDD) array, that uses a low current biasing adaptor is disclosed. The biasing adaptor is customizable for any desired geometry of the drift detector single cell with minimum drift time of carriers. The biasing adaptor has spiral shaped ion-implants that generate the desired voltage profile. The biasing adaptor can be processed on the same wafer as the drift detector array and only one biasing adaptor chip/side is needed for one drift detector array to generate the voltage profiles on the front side and back side of the detector array.

  1. The Fallacy of Drifting Snow

    NASA Astrophysics Data System (ADS)

    Andreas, Edgar L.

    2011-12-01

    A common parametrization over snow-covered surfaces that are undergoing saltation is that the aerodynamic roughness length for wind speed ( z 0) scales as {α u_ast^2/g}, where u * is the friction velocity, g is the acceleration of gravity, and α is an empirical constant. Data analyses seem to support this scaling: many published plots of z 0 measured over snow demonstrate proportionality to {u_ast^2 }. In fact, I show similar plots here that are based on two large eddy-covariance datasets: one collected over snow-covered Arctic sea ice; another collected over snow-covered Antarctic sea ice. But in these and in most such plots from the literature, the independent variable, u *, was used to compute z 0 in the first place; the plots thus suffer from fictitious correlation that causes z 0 to unavoidably increase with u * without any intervening physics. For these two datasets, when I plot z 0 against u * derived from a bulk flux algorithm—and thus minimize the fictitious correlation— z 0 is independent of u * in the drifting snow region, u * ≥ 0.30 ms-1. I conclude that the relation {z_0 = α u_ast^2/g} when snow is drifting is a fallacy fostered by analyses that suffer from fictitious correlation.

  2. Investigations of SPS Orbit Drifts

    SciTech Connect

    Drøsdal, Lene; Bracco, Chiara; Cornelis, Karel; Goddard, Brennan; Kain, Verena; Meddahi, Malika; Wenninger, Jorg; Gianfelice-Wendt, Eliana

    2014-07-01

    The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the second source of variations.

  3. Evidence that attitude accessibility augments the relationship between speeding attitudes and speeding behavior: a test of the MODE model in the context of driving.

    PubMed

    Elliott, Mark A; Lee, Emme; Robertson, Jamie S; Innes, Rhona

    2015-01-01

    According to the MODE model of attitude-to-behavior processes, attitude accessibility augments attitude-behavior correspondence, reflecting an automatic influence of attitudes on behavior. We therefore tested whether attitude accessibility moderates the attitude-behavior relationship in a context that is governed by characteristically automatic behavior, namely driving. In study 1 (correlational design), participants (N=130) completed online questionnaire measures of the valences and accessibilities of their attitudes towards speeding. Two weeks later, online questionnaire measures of subsequent speeding behavior were obtained. Attitude valence was a significantly better predictor of behavior at high (mean+1SD) versus low (mean-1SD) levels of attitude accessibility. In study 2 (experimental design), attitude accessibility was manipulated with a repeated attitude expression task. Immediately after the manipulation, participants (N=122) completed online questionnaire measures of attitude valence and accessibility, and two weeks later, subsequent speeding behavior. Increased attitude accessibility in the experimental (versus control) condition generated an increase in attitude-behavior correspondence. The findings are consistent with the MODE model's proposition that attitudes can exert an automatic influence on behavior. Interventions to reduce speeding could usefully increase the accessibility of anti-speeding attitudes and reduce the accessibility of pro-speeding attitudes.

  4. Experimental observation of the drift shadow effect using X-ray absorption imaging

    NASA Astrophysics Data System (ADS)

    Altman, Susan J.; Forsberg, Aleeca A.; Peplinski, William J.; Ho, Clifford K.

    2008-01-01

    SummaryX-ray absorption imaging is used to test the concept of the drift shadow in geological samples. The drift shadow model predicts that water travels around underground tunnels, or drifts, leaving areas of high saturation along the sides of the drift (roof-drip lobe) and an area of low saturation beneath the drift (drift shadow). The drift shadow model could impact nuclear waste repositories designed with open tunnels, such as Yucca Mountain, by impacting the flux available to transport waste beneath the repository. However, without strong evidence for the drift shadow effect, it is difficult to justify its inclusion in performance assessment calculations. Twelve experiments were run looking at the impact of fracture aperture, inflow rate and geological heterogeneity on flow in the vicinity of a drift. Test cells of dimensions 10.1 cm × 15.0 cm × 2.5 cm were constructed using geological samples relevant to the Yucca Mountain project. A semi-circle of sample was removed from one side of the cell creating an artificial drift (assuming symmetry). An artificial fracture was created through the middle of each test cell parallel to the face of the sample. Potassium iodide tracer solution was dripped into the artificial fracture at the top of the sample. X-ray imaging allowed for visualization of the tracer flow paths over the duration of the experiment. In addition, samples were collected at the bottom of the flow cell to determine the lateral distribution of the outflow. Results showed distinct flow paths of tracer solution around the drift followed by shedding at the edge of the drift (roof-drip lobes), as predicted by the drift shadow model. In addition, the distribution of discharge under the drift supported the drift shadow model with less discharge directly under the drift and greater discharge to the side of the drift in most experiments. In the experiments with smaller fracture apertures and lower flow rates, discharge beneath the drift was greater than

  5. WORLD SURFACE CURRENTS FROM SHIP'S DRIFT OBSERVATIONS

    SciTech Connect

    Duncan, C.P.; Schladow, S.G.

    1980-11-01

    Over 4 million observations of ship's drift are on file at the U.S. National Oceanographic Data Centre, in Washington, D. C., representing a vast amount of information on ocean surface currents. The observed drift speeds are dependent on the frequency of occurence of the particular current speeds and the frequency of observation. By comparing frequency of observation with the drift speeds observed it is possible to confirm known current patterns and detect singularities in surface currents.

  6. Electron injection in semiconductor drift detectors

    SciTech Connect

    Rehak, P. ); Gatti, E.; Longoni, A.; Sampietro, M.; Castoldi, A. ); Vacchi, A. )

    1990-01-01

    The paper reports the first successful results of a simple MOS structure to inject electrons at a given position in Silicon Drift Detectors. The structure allows on-line calibration of the drift velocity of electrons within the detector. The calibration is a practical method to trace the temperature dependence of the electron mobility. Several of these injection structures can be implemented in silicon drift detectors without additional steps in the fabrication process. 5 refs., 11 figs.

  7. Drift chamber tracking with neural networks

    SciTech Connect

    Lindsey, C.S.; Denby, B.; Haggerty, H.

    1992-10-01

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  8. Charge injectors of ALICE Silicon Drift Detector

    NASA Astrophysics Data System (ADS)

    Rashevsky, A.; Batigne, G.; Beole, S.; Coli, S.; Crescio, E.; Deremigis, P.; Giraudo, G.; Mazza, G.; Prino, F.; Riccati, L.; Rivetti, A.; Toscano, L.; Tosello, F.; Vacchi, A.; Wheadon, R.; Zampa, G.

    2007-03-01

    Large area, 7.25×8.76 cm2, Silicon Drift Detector (SDD) has been developed for the ALICE experiment at CERN [A. Vacchi, et al., Nucl. Instr. and Meth. A 306 (1991) 187; A. Rashevsky, et al., Nucl. Instr. and Meth. A 461 (2001) 133-138; A. Rashevsky, et al., Nucl. Instr. and Meth. A 485 (2002) 54; P. Burger, C. Piemonte, A. Rashevsky, A. Roncastri, A. Vacchi, INFN/TC-02/07; C. Piemonte, A. Rashevsky, INFN/TC-02/08; C. Piemonte, A. Rashevsky, D. Nouais, INFN/TC-00/04. C. Piemonte, A. Rashevsky, A. Vacchi, ALICE-INT-2002-15, 2002; Inner Tracking System, CERN/LHCC, June 1999]. SDDs form two out of six cylindrical layers of the ALICE inner tracking system. The 260 high-quality SDDs needed to equip these two layers have been selected. One of the detector design elements devoted to allow controlled operating conditions is the on-board arrays of point-like charge injectors [D. Nouais, et al., CERN-ALICE-PUB-99-31; V. Bonvicini, et al., Il Nuovo Cimento 112AN (1-2) (1999) 137-146]. In the case of an SDD they are essential to trace, with the required frequency and precision, the changes in drift velocity induced by temperature variations. In order to ensure operating stability during the 10 years of the ALICE experiment the bias scheme of the charge injectors exploits the electrical properties not only of a detector itself, but also those of the cables mounted onto it, thus constituting a module. Computer simulations of the equivalent circuit revealed a significant improvement of the injection efficiency. Subsequent experimental tests of the first assembled modules confirmed the predicted performances. We report the layout of the charge injectors integrated in the ALICE SDD, as well as test results.

  9. Redshift drift constraints on holographic dark energy

    NASA Astrophysics Data System (ADS)

    He, Dong-Ze; Zhang, Jing-Fei; Zhang, Xin

    2017-03-01

    The Sandage-Loeb (SL) test is a promising method for probing dark energy because it measures the redshift drift in the spectra of Lyman- α forest of distant quasars, covering the "redshift desert" of 2 ≲ z ≲ 5, which is not covered by existing cosmological observations. Therefore, it could provide an important supplement to current cosmological observations. In this paper, we explore the impact of SL test on the precision of cosmological constraints for two typical holographic dark energy models, i.e., the original holographic dark energy (HDE) model and the Ricci holographic dark energy (RDE) model. To avoid data inconsistency, we use the best-fit models based on current combined observational data as the fiducial models to simulate 30 mock SL test data. The results show that SL test can effectively break the existing strong degeneracy between the present-day matter density Ωm0 and the Hubble constant H 0 in other cosmological observations. For the considered two typical dark energy models, not only can a 30-year observation of SL test improve the constraint precision of Ωm0 and h dramatically, but can also enhance the constraint precision of the model parameters c and α significantly.

  10. THERMAL EVALUATION OF DIFFERENT DRIFT DIAMETER SIZES

    SciTech Connect

    H.M. Wade

    1999-01-04

    The purpose of this calculation is to estimate the thermal response of a repository-emplaced waste package and its corresponding drift wall surface temperature with different drift diameters. The case examined is that of a 21 pressurized water reactor (PWR) uncanistered fuel (UCF) waste package loaded with design basis spent nuclear fuel assemblies. This calculation evaluates a 3.5 meter to 6.5 meter drift diameter range in increments of 1.0 meters. The time-dependent temperatures of interest, as determined by this calculation, are the spent nuclear fuel cladding temperature, the waste package surface temperature, and the drift wall surface temperature.

  11. Biology Undergraduates’ Misconceptions about Genetic Drift

    PubMed Central

    Andrews, T. M.; Price, R. M.; Mead, L. S.; McElhinny, T. L.; Thanukos, A.; Perez, K. E.; Herreid, C. F.; Terry, D. R.; Lemons, P. P.

    2012-01-01

    This study explores biology undergraduates’ misconceptions about genetic drift. We use qualitative and quantitative methods to describe students’ definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct misconceptions about genetic drift. The accuracy of students’ conceptions ranges considerably, from responses indicating only superficial, if any, knowledge of any aspect of evolution to responses indicating knowledge of genetic drift but confusion about the nuances of genetic drift. After instruction, a significantly greater number of responses indicate some knowledge of genetic drift (p = 0.005), but 74.6% of responses still contain at least one misconception. We conclude by presenting a framework that organizes how students’ conceptions of genetic drift change with instruction. We also articulate three hypotheses regarding undergraduates’ conceptions of evolution in general and genetic drift in particular. We propose that: 1) students begin with undeveloped conceptions of evolution that do not recognize different mechanisms of change; 2) students develop more complex, but still inaccurate, conceptual frameworks that reflect experience with vocabulary but still lack deep understanding; and 3) some new misconceptions about genetic drift emerge as students comprehend more about evolution. PMID:22949422

  12. A long time low drift integrator with temperature control.

    PubMed

    Zhang, Donglai; Yan, Xiaolan; Zhang, Enchao; Pan, Shimin

    2016-10-01

    The output of an operational amplifier always contains signals that could not have been predicted, even with knowledge of the input and an accurately determined closed-loop transfer function. These signals lead to integrator zero-drift over time. A new type of integrator system with a long-term low-drift characteristic has therefore been designed. The integrator system is composed of a temperature control module and an integrator module. The aluminum printed circuit board of the integrator is glued to a thermoelectric cooler to maintain the electronic components at a stable temperature. The integration drift is automatically compensated using an analog-to-digital converter/proportional integration/digital-to-analog converter control circuit. Performance testing in a standard magnet shows that the proposed integrator, which has an integration time constant of 10 ms, has a low integration drift (<5 mV) over 1000 s after repeated measurements. The integrator can be used for magnetic flux measurements in most tokamaks and in the wire rope nondestructive test.

  13. Drift-reducing nozzles and their biological efficacy.

    PubMed

    Nuyttens, D; Dhoop, M; De Blauwer, V; Hermann, O; Hubrechts, W; Mestdagh, I; Dekeyser, D

    2009-01-01

    In 2007 and 2008, field trials were carried out with different standard and drift-reducing nozzles in sugar beet, maize, chicory, Belgian endive (all herbicide applications), wheat (fungicide application) and potatoes (Haulm killing herbicide application). The effect of nozzle type (standard flat fan, low-drift flat fan, air injection), nozzle size (ISO 02, 03 and 04) and application volume on the biological efficacy was investigated. All applications were done using a plot sprayer with volume rates ranging from 160 to 320 l.ha(-1) at recommended dose rates with commonly used (mix of) plant protection products. For each crop, the experiments included four replicates in a randomized block design. Depending on the type of application, the efficacy was measured in terms of weed control, disease and yield level, percentage dead leaf and stem, etc. In a previous research, drift and droplet characteristics of the different techniques were measured. In general no important effect of application technique on biological efficacy was observed for the tested herbicide and fungicide applications within the interval of volume rates and droplet size tested. Drift-reducing nozzles performed similar as conventional nozzles under good spraying conditions and using a correct spray application technique.

  14. A long time low drift integrator with temperature control

    NASA Astrophysics Data System (ADS)

    Zhang, Donglai; Yan, Xiaolan; Zhang, Enchao; Pan, Shimin

    2016-10-01

    The output of an operational amplifier always contains signals that could not have been predicted, even with knowledge of the input and an accurately determined closed-loop transfer function. These signals lead to integrator zero-drift over time. A new type of integrator system with a long-term low-drift characteristic has therefore been designed. The integrator system is composed of a temperature control module and an integrator module. The aluminum printed circuit board of the integrator is glued to a thermoelectric cooler to maintain the electronic components at a stable temperature. The integration drift is automatically compensated using an analog-to-digital converter/proportional integration/digital-to-analog converter control circuit. Performance testing in a standard magnet shows that the proposed integrator, which has an integration time constant of 10 ms, has a low integration drift (<5 mV) over 1000 s after repeated measurements. The integrator can be used for magnetic flux measurements in most tokamaks and in the wire rope nondestructive test.

  15. Flight Services and Aircraft Access: Active Flow Control Vertical Tail and Insect Accretion and Mitigation Flight Test

    NASA Technical Reports Server (NTRS)

    Whalen, Edward A.

    2016-01-01

    This document serves as the final report for the Flight Services and Aircraft Access task order NNL14AA57T as part of NASA Environmentally Responsible Aviation (ERA) Project ITD12A+. It includes descriptions of flight test preparations and execution for the Active Flow Control (AFC) Vertical Tail and Insect Accretion and Mitigation (IAM) experiments conducted on the 757 ecoDemonstrator. For the AFC Vertical Tail, this is the culmination of efforts under two task orders. The task order was managed by Boeing Research & Technology and executed by an enterprise-wide Boeing team that included Boeing Research & Technology, Boeing Commercial Airplanes, Boeing Defense and Space and Boeing Test and Evaluation. Boeing BR&T in St. Louis was responsible for overall Boeing project management and coordination with NASA. The 757 flight test asset was provided and managed by the BCA ecoDemonstrator Program, in partnership with Stifel Aircraft Leasing and the TUI Group. With this report, all of the required deliverables related to management of this task order have been met and delivered to NASA as summarized in Table 1. In addition, this task order is part of a broader collaboration between NASA and Boeing.

  16. Understanding Structural Barriers to Accessing HIV Testing and Prevention Services Among Black Men Who Have Sex with Men (BMSM) in the United States

    PubMed Central

    Wilton, Leo; Phillips, Gregory; Glick, Sara Nelson; Kuo, Irene; Brewer, Russell A.; Elliott, Ayana; Watson, Christopher; Magnus, Manya

    2015-01-01

    Structural-level factors have contributed to the substantial disproportionate rates of HIV among Black men who have sex with men (BMSM) in the United States. Despite insufficient HIV testing patterns, however, there is a void in research investigating the relationship between structural factors and access to HIV testing and prevention services among BMSM. Building on previous scholarly work and incorporating a dynamic social systems conceptual framework, we conducted a comprehensive review of the literature on structural barriers to HIV testing and prevention services among BMSM across four domains: healthcare, stigma and discrimination, incarceration, and poverty. We found that BMSM experience inadequate access to culturally competent services, stigma and discrimination that impede access to services, a deficiency of services in correctional institutions, and limited services in areas where BMSM live. Structural interventions that eliminate barriers to HIV testing and prevention services and provide BMSM with core skills to navigate complex systems are needed. PMID:24531769

  17. Understanding structural barriers to accessing HIV testing and prevention services among black men who have sex with men (BMSM) in the United States.

    PubMed

    Levy, Matthew E; Wilton, Leo; Phillips, Gregory; Glick, Sara Nelson; Kuo, Irene; Brewer, Russell A; Elliott, Ayana; Watson, Christopher; Magnus, Manya

    2014-05-01

    Structural-level factors have contributed to the substantial disproportionate rates of HIV among Black men who have sex with men (BMSM) in the United States. Despite insufficient HIV testing patterns, however, there is a void in research investigating the relationship between structural factors and access to HIV testing and prevention services among BMSM. Building on previous scholarly work and incorporating a dynamic social systems conceptual framework, we conducted a comprehensive review of the literature on structural barriers to HIV testing and prevention services among BMSM across four domains: healthcare, stigma and discrimination, incarceration, and poverty. We found that BMSM experience inadequate access to culturally competent services, stigma and discrimination that impede access to services, a deficiency of services in correctional institutions, and limited services in areas where BMSM live. Structural interventions that eliminate barriers to HIV testing and prevention services and provide BMSM with core skills to navigate complex systems are needed.

  18. The Genetic Drift Inventory: A Tool for Measuring What Advanced Undergraduates Have Mastered about Genetic Drift

    ERIC Educational Resources Information Center

    Price, Rebecca M.; Andrews, Tessa C.; McElhinny, Teresa L.; Mead, Louise S.; Abraham, Joel K.; Thanukos, Anna; Perez, Kathryn E.

    2014-01-01

    Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures…

  19. Autoresonant control of drift waves

    NASA Astrophysics Data System (ADS)

    Shagalov, A. G.; Rasmussen, J. Juul; Naulin, V.

    2017-03-01

    The control of nonlinear drift waves in a magnetized plasmas column has been investigated. The studies are based on the Hasegawa–Mima model, which is solved on a disk domain with radial inhomogeneity of the plasma density. The system is forced by a rotating potential with varying frequency defined on the boundary. To excite and control the waves we apply the autoresonant effect, taking place when the amplitude of the forcing exceeds a threshold value and the waves are phase-locked with the forcing. We demonstrate that the autoresonant approach is applicable for excitation of a range of steady nonlinear waves of the lowest azimuthal mode numbers and for controlling their amplitudes and phases. We also demonstrate the excitation of zonal flows (m = 0 modes), which are controlled via the forced modes.

  20. Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Research Team . Volume 2; Appendices

    NASA Technical Reports Server (NTRS)

    Kelly, Michael J.

    2013-01-01

    The Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage (horizontal and vertical tail). This report contains the Appendices to Volume I.

  1. Intonation in unaccompanied singing: accuracy, drift, and a model of reference pitch memory.

    PubMed

    Mauch, Matthias; Frieler, Klaus; Dixon, Simon

    2014-07-01

    This paper presents a study on intonation and intonation drift in unaccompanied singing, and proposes a simple model of reference pitch memory that accounts for many of the effects observed. Singing experiments were conducted with 24 singers of varying ability under three conditions (Normal, Masked, Imagined). Over the duration of a recording, ∼50 s, a median absolute intonation drift of 11 cents was observed. While smaller than the median note error (19 cents), drift was significant in 22% of recordings. Drift magnitude did not correlate with other measures of singing accuracy, singing experience, or the presence of conditions tested. Furthermore, it is shown that neither a static intonation memory model nor a memoryless interval-based intonation model can account for the accuracy and drift behavior observed. The proposed causal model provides a better explanation as it treats the reference pitch as a changing latent variable.

  2. DRIFT: a directionally sensitive dark matter detector

    NASA Astrophysics Data System (ADS)

    Morgan, Ben; Drift; Uk Dark Matter Collaborations

    2003-11-01

    Directional Recoil Identification From Tracks-I (DRIFT) is the world's first WIMP dark matter detector with sensitivity to the directions of nuclear recoils. The distribution of WIMP induced nuclear recoil directions offers the most powerful way of positively identifying a WIMP signal. This paper discusses the DRIFT-I detector and considers future high spatial resolution readout schemes.

  3. The high momentum spectrometer drift chambers

    NASA Astrophysics Data System (ADS)

    Abbott, D.; Baker, O. K.; Beaufait, J.; Bennett, C.; Bryant, E.; Carlini, R.; Kross, B.; McCauley, A.; Naing, W.; Shin, T.; Vulcan, W.

    1992-12-01

    The High Momentum Spectrometer in Hall C will use planar drift chambers for charged particle track reconstruction. The chambers are constructed using well understood technology and a conventional gas mixture. Two (plus one spare) drift chambers will be constructed for this spectrometers. Each chamber will contain 6 planes of readout channels. This paper describes the chamber design and gas handling system used.

  4. Spray Drift Issues and Technologies for Mitigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicide-induced plant damage due to off-target spray drift has become a major problem in some regions prompting States to take regulatory action regarding drift mitigation. For example, the Arkansas Plant Board has proposed new regulations regarding spray of Glyphosate and 2, 4-D. These regulation...

  5. Biology Undergraduates' Misconceptions about Genetic Drift

    ERIC Educational Resources Information Center

    Andrews, T. M.; Price, R. M.; Mead, L. S.; McElhinny, T. L.; Thanukos, A.; Perez, K. E.; Herreid, C. F.; Terry, D. R.; Lemons, P. P.

    2012-01-01

    This study explores biology undergraduates' misconceptions about genetic drift. We use qualitative and quantitative methods to describe students' definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct…

  6. Resistive Drift Waves in a Bumpy Torus

    SciTech Connect

    J.L.V. Lewandowski

    2004-01-12

    A computational study of resistive drift waves in the edge plasma of a bumpy torus is presented. The magnetohydrodynamic equilibrium is obtained from a three-dimensional local equilibrium model. The use of a local magnetohydrodynamic equilibrium model allows for a computationally efficient systematic study of the impact of the magnetic field structure on drift wave stability.

  7. Detecting and correcting sensor drifts in long-term weather data.

    PubMed

    von Arx, Georg; Dobbertin, Matthias; Rebetez, Martine

    2013-06-01

    Quality control of long-term monitoring data of thousands and millions of individual records as present in meteorological data is cumbersome. In such data series, sensor drifts, stalled values, and scale shifts may occur and potentially result in flawed conclusions if not noticed and handled properly. However, there is no established standard procedure to perform quality control of high-frequency meteorological data. In this paper, we outline a procedure to remove sensor drift in high-frequency data series using the example of 15-year-long sets of hourly relative humidity (RH) data from 28 stations subdivided into 202 individual sensor operation periods. The procedure involves basic quality control, relative homogeneity testing, and drift removal. Significant sensor drifts were observed in 40.6 % of all sensor operation periods. The drifts varied between data series and depended in a complex, usually inconsistent way on absolute RH values; within single series for instance, a drift could be negative in the lower RH range and positive in the upper RH range. Detrending changed RH values by, on average, 1.96 %. For one fifth of the detrended data, adjustments were 2.75 % and more of the measured value, and in one tenth 4.75 % and more. Overall, drifts were strongest for RH values close to 100 %. The detrending procedure proved to effectively remove sensor drifts. The principles of the procedure also apply to other meteorological parameters and more generally to any time series of data for which comparable reference data are available.

  8. Drift-induced Deceleration of Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Dalla, S.; Marsh, M. S.; Laitinen, T.

    2015-07-01

    We investigate the deceleration of solar energetic particles (SEPs) during their propagation from the Sun through interplanetary space, in the presence of weak to strong scattering in a Parker spiral configuration, using relativistic full orbit test particle simulations. The calculations retain all three spatial variables describing particles’ trajectories, allowing us to model any transport across the magnetic field. Large energy change is shown to occur for protons, due to the combined effect of standard adiabatic deceleration and a significant contribution from particle drift in the direction opposite to that of the solar wind electric field. The latter drift-induced deceleration is found to have a stronger effect for SEP energies than for galactic cosmic rays. The kinetic energy of protons injected at 1 MeV is found to be reduced by between 35% and 90% after four days, and for protons injected at 100 MeV by between 20% and 55%. The overall degree of deceleration is a weak function of the scattering mean free path, showing that, although adiabatic deceleration plays a role, a large contribution is due to particle drift. Current SEP transport models are found to account for drift-induced deceleration in an approximate way and their accuracy will need to be assessed in future work.

  9. Eye-Safe Lidar System for Pesticide Spray Drift Measurement

    PubMed Central

    Gregorio, Eduard; Rocadenbosch, Francesc; Sanz, Ricardo; Rosell-Polo, Joan R.

    2015-01-01

    Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar) technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m. PMID:25658395

  10. Eye-safe lidar system for pesticide spray drift measurement.

    PubMed

    Gregorio, Eduard; Rocadenbosch, Francesc; Sanz, Ricardo; Rosell-Polo, Joan R

    2015-02-04

    Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar) technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m.

  11. Ground Control for Emplacement Drifts for LA

    SciTech Connect

    Y. Sun

    2004-07-09

    The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c).

  12. Low latitude electrodynamic plasma drifts - A review

    NASA Technical Reports Server (NTRS)

    Fejer, B. G.

    1991-01-01

    The characteristics and driving mechanisms of low latitude ExB plasma drifts and electric fields particularly at F-region heights are reviewed. It is concluded that the general characteristics of the quiet-time plasma can be explained as resulting from E- and F-region dynamo and interhemispheric coupling processes. The disturbance dynamo effects are found to be responsible for the drift perturbations following the periods of enhanced magnetic activity. The prompt penetration of high-latitude electric fields to lower latitudes produces large perturbations on the upward/poleward drifts, but has no significant effect on the low-latitude and the equatorial zonal drifts. Detailed low-latitude and global numerical models for studying the characteristics of plasma drifts are capable of reproducing the latitudinal variation of the perturbation electric fields and their diurnal variations.

  13. Ability or Access-Ability: Differential Item Functioning of Items on Alternate Performance-Based Assessment Tests for Students with Visual Impairments

    ERIC Educational Resources Information Center

    Zebehazy, Kim T.; Zigmond, Naomi; Zimmerman, George J.

    2012-01-01

    Introduction: This study investigated differential item functioning (DIF) of test items on Pennsylvania's Alternate System of Assessment (PASA) for students with visual impairments and severe cognitive disabilities and what the reasons for the differences may be. Methods: The Wilcoxon signed ranks test was used to analyze differences in the scores…

  14. Quantifying Particle Numbers and Mass Flux in Drifting Snow

    NASA Astrophysics Data System (ADS)

    Crivelli, Philip; Paterna, Enrico; Horender, Stefan; Lehning, Michael

    2016-12-01

    We compare two of the most common methods of quantifying mass flux, particle numbers and particle-size distribution for drifting snow events, the snow-particle counter (SPC), a laser-diode-based particle detector, and particle tracking velocimetry based on digital shadowgraphic imaging. The two methods were correlated for mass flux and particle number flux. For the SPC measurements, the device was calibrated by the manufacturer beforehand. The shadowgrapic imaging method measures particle size and velocity directly from consecutive images, and before each new test the image pixel length is newly calibrated. A calibration study with artificially scattered sand particles and glass beads provides suitable settings for the shadowgraphical imaging as well as obtaining a first correlation of the two methods in a controlled environment. In addition, using snow collected in trays during snowfall, several experiments were performed to observe drifting snow events in a cold wind tunnel. The results demonstrate a high correlation between the mass flux obtained for the calibration studies (r ≥slant 0.93) and good correlation for the drifting snow experiments (r ≥slant 0.81). The impact of measurement settings is discussed in order to reliably quantify particle numbers and mass flux in drifting snow. The study was designed and performed to optimize the settings of the digital shadowgraphic imaging system for both the acquisition and the processing of particles in a drifting snow event. Our results suggest that these optimal settings can be transferred to different imaging set-ups to investigate sediment transport processes.

  15. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    P. Dixon

    2004-04-05

    The purpose of this Model Report (REV02) is to document the unsaturated zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrological-chemical (THC) processes on UZ flow and transport. This Model Report has been developed in accordance with the ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this Model Report in Section 1.12, Work Package AUZM08, ''Coupled Effects on Flow and Seepage''. The plan for validation of the models documented in this Model Report is given in Attachment I, Model Validation Plans, Section I-3-4, of the TWP. Except for variations in acceptance criteria (Section 4.2), there were no deviations from this TWP. This report was developed in accordance with AP-SIII.10Q, ''Models''. This Model Report documents the THC Seepage Model and the Drift Scale Test (DST) THC Model. The THC Seepage Model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC model is a drift-scale process model relying on the same conceptual model and much of the same input data (i.e., physical, hydrological, thermodynamic, and kinetic) as the THC Seepage Model. The DST THC Model is the primary method for validating the THC Seepage Model. The DST THC Model compares predicted water and gas compositions, as well as mineral alteration patterns, with observed data from the DST. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal-loading conditions, and predict the evolution of mineral alteration and fluid chemistry around potential waste emplacement drifts. The DST THC Model is used solely for the validation of the THC

  16. Tools for assessing the quality and accessibility of online health information: initial testing among breast cancer websites.

    PubMed

    Whitten, Pamela; Nazione, Samantha; Lauckner, Carolyn

    2013-12-01

    Health websites are used frequently, but there are many concerns about their value as information sources. Additionally, there are numerous personal barriers that prevent individuals from wholly benefitting from them. In order to assess the quality of health websites and their accessibility to users, we created tools based on previous research that examine design aspects, information validity, motivational health content and literacy content. To test these tools, we examined 155 breast cancer websites and created scores for each assessment tool to describe the percent of constructs on the average website. Results demonstrated that websites performed best on the design tool followed by the information validity, motivational health content and literacy assessment tools. The average website contained the majority of the design and information validity constructs, but only about a third of the motivational health or literacy constructs. Multiple items from the motivational health content and literacy assessment tools were not found on any of the websites, and many were only represented on a handful of sites. Overall, the assessment tools were useful in evaluating the quality of websites, and could serve as valuable resources for health website developers in the future.

  17. Genetic Drift of HIV Populations in Culture

    PubMed Central

    Voronin, Yegor; Holte, Sarah; Overbaugh, Julie; Emerman, Michael

    2009-01-01

    Populations of Human Immunodeficiency Virus type 1 (HIV-1) undergo a surprisingly large amount of genetic drift in infected patients despite very large population sizes, which are predicted to be mostly deterministic. Several models have been proposed to explain this phenomenon, but all of them implicitly assume that the process of virus replication itself does not contribute to genetic drift. We developed an assay to measure the amount of genetic drift for HIV populations replicating in cell culture. The assay relies on creation of HIV populations of known size and measurements of variation in frequency of a neutral allele. Using this assay, we show that HIV undergoes approximately ten times more genetic drift than would be expected from its population size, which we defined as the number of infected cells in the culture. We showed that a large portion of the increase in genetic drift is due to non-synchronous infection of target cells. When infections are synchronized, genetic drift for the virus is only 3-fold higher than expected from its population size. Thus, the stochastic nature of biological processes involved in viral replication contributes to increased genetic drift in HIV populations. We propose that appreciation of these effects will allow better understanding of the evolutionary forces acting on HIV in infected patients. PMID:19300501

  18. Access to edge scenarios for testing a scraper element in early operation phases of Wendelstein 7-X

    DOE PAGES

    Holbe, H.; Pedersen, T. Sunn; Geiger, J.; ...

    2016-01-29

    The edge topology of magnetic fusion devices is decisive for the control of the plasma exhaust. In Wendelstein 7-X, the island divertor concept will be used, for which the edge topology can change significantly as the internal currents in a plasma discharge evolve towards steady-state. Consequently, the device has been optimized to minimize such internal currents, in particular the bootstrap current [1]. Nonetheless, there are predicted pulse scenarios where effects of the remaining internal currents could potentially lead to overload of plasma-facing components. These internal currents are predicted to evolve on long time scales (tens of seconds) so their effectsmore » on the edge topology and the divertor heat loads may not be experimentally accessible in the first years of W7-X operation, where only relatively short pulses are possible. However, we show here that for at least one important long-pulse divertor operation issue, relevant physics experiments can be performed already in short-pulse operation, through judicious adjustment of the edge topology by the use of the existing coil sets. The specific issue studied here is a potential overload of the divertor element edges. This overload might be mitigated by the installation of an extra set of plasma-facing components, so-called scraper elements, as suggested in earlier publications. It is shown here that by a targeted control of edge topology, the effectiveness of such scraper elements can be tested already with uncooled test-scraper elements in short-pulse operation. Furthermore, this will allow an early and well-informed decision on whether long-pulse-capable (actively cooled) scraper elements should be built and installed.« less

  19. Access to edge scenarios for testing a scraper element in early operation phases of Wendelstein 7-X

    SciTech Connect

    Holbe, H.; Pedersen, T. Sunn; Geiger, J.; Bozhenkov, S.; Kornejew, P; Feng, Y.; Lore, Jeremy D.; Lumsdaine, Arnold; Konig, R.

    2016-01-29

    The edge topology of magnetic fusion devices is decisive for the control of the plasma exhaust. In Wendelstein 7-X, the island divertor concept will be used, for which the edge topology can change significantly as the internal currents in a plasma discharge evolve towards steady-state. Consequently, the device has been optimized to minimize such internal currents, in particular the bootstrap current [1]. Nonetheless, there are predicted pulse scenarios where effects of the remaining internal currents could potentially lead to overload of plasma-facing components. These internal currents are predicted to evolve on long time scales (tens of seconds) so their effects on the edge topology and the divertor heat loads may not be experimentally accessible in the first years of W7-X operation, where only relatively short pulses are possible. However, we show here that for at least one important long-pulse divertor operation issue, relevant physics experiments can be performed already in short-pulse operation, through judicious adjustment of the edge topology by the use of the existing coil sets. The specific issue studied here is a potential overload of the divertor element edges. This overload might be mitigated by the installation of an extra set of plasma-facing components, so-called scraper elements, as suggested in earlier publications. It is shown here that by a targeted control of edge topology, the effectiveness of such scraper elements can be tested already with uncooled test-scraper elements in short-pulse operation. Furthermore, this will allow an early and well-informed decision on whether long-pulse-capable (actively cooled) scraper elements should be built and installed.

  20. Access to edge scenarios for testing a scraper element in early operation phases of Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Hölbe, H.; Pedersen, T. Sunn; Geiger, J.; Bozhenkov, S.; König, R.; Feng, Y.; Lore, J.; Lumsdaine, A.; the Wendelstein 7-X Team

    2016-02-01

    The edge topology of magnetic fusion devices is decisive for the control of the plasma exhaust. In Wendelstein 7-X, the island divertor concept will be used, for which the edge topology can change significantly as the internal currents in a plasma discharge evolve towards steady-state. Consequently, the device has been optimized to minimize such internal currents, in particular the bootstrap current [1]. Nonetheless, there are predicted pulse scenarios where effects of the remaining internal currents could potentially lead to overload of plasma-facing components. These internal currents are predicted to evolve on long time scales (tens of seconds) so their effects on the edge topology and the divertor heat loads may not be experimentally accessible in the first years of W7-X operation, where only relatively short pulses are possible. However, we show here that for at least one important long-pulse divertor operation issue, relevant physics experiments can be performed already in short-pulse operation, through judicious adjustment of the edge topology by the use of the existing coil sets. The specific issue studied here is a potential overload of the divertor element edges. This overload might be mitigated by the installation of an extra set of plasma-facing components, so-called scraper elements, as suggested in earlier publications. It is shown here that by a targeted control of edge topology, the effectiveness of such scraper elements can be tested already with uncooled test-scraper elements in short-pulse operation. This will allow an early and well-informed decision on whether long-pulse-capable (actively cooled) scraper elements should be built and installed.

  1. Testing the Digital Divide: Does Access to High-Quality Use of Technology in Schools Affect Student Achievement?

    ERIC Educational Resources Information Center

    Talley, Gregory Keith

    2012-01-01

    This study investigates the relationship between access, use of technology and student achievement in public middle schools in Maryland. The objective of this study was to determine whether a digital divide (differences in access and utilization of technology based on student characteristics of race, socioeconomic status, and gender) exists among…

  2. Ion Drift Meter for Dynamics Explorer

    NASA Technical Reports Server (NTRS)

    Heelis, R. A.; Hanson, W. B.; Lippincott, C. R.; Zuccaro, D. R.

    1982-01-01

    The ion drift meter for Dynamics Explorer B is discussed. It measures two mutually perpendicular angles of arrival of thermal ions with respect to the sensor look directions. These angles lie in the vertical and horizontal planes and may be thought of as pitch and yaw in the conventional aerodynamic sense. The components of the ion drift velocity along vertical and horizontal axes through the spacecraft body are derived to first order from knowledge of the spacecraft velocity vector and more accurately with additional knowledge of the component of ion drift along the sensor look direction.

  3. Interaction between a drifting spiral and defects

    SciTech Connect

    Zou, X.; Levine, H. ); Kessler, D.A. )

    1993-02-01

    Spiral waves, a type of reentrant excitation,'' are believed to be associated with the most dangerous cardiac arrhythmias, including ventricular tachycardia and fibrillation. Recent experimental findings have implicated defective regions as a means of trapping spirals which would otherwise drift and (eventually) disappear. Here, we model the myocardium as a simple excitable medium and study via simulation the interaction between a drifting spiral and one or more such defects. We interpret our results in terms of a criterion for the transition between trapped and untrapped drifting spirals.

  4. Collisional Drift Waves in Stellarator Plasmas

    SciTech Connect

    J.L.V. Lewandowski

    2003-10-07

    A computational study of resistive drift waves in the edge plasma of a stellarator with an helical magnetic axis is presented. Three coupled field equations, describing the collisional drift wave dynamics in the linear approximation, are solved as an initial-value problem along the magnetic field line. The magnetohydrodynamic equilibrium is obtained from a three-dimensional local equilibrium model. The use of a local magnetohydrodynamic equilibrium model allows for a computationally efficient systematic study of the impact of the magnetic field structure on drift wave stability.

  5. In-Drift Precipitates/Salts Model

    SciTech Connect

    P. Mariner

    2003-10-21

    As directed by ''Technical Work Plan For: Engineered Barrier System Department Modeling and Testing FY03 Work Activities'' (BSC 2003 [165601]), the In-Drift Precipitates/Salts (IDPS) model is developed and refined to predict the aqueous geochemical effects of evaporation in the proposed repository. The purpose of this work is to provide a model for describing and predicting the postclosure effects of evaporation and deliquescence on the chemical composition of water within the proposed Engineered Barrier System (EBS). Application of this model is to be documented elsewhere for the Total System Performance Assessment License Application (TSPA-LA). The principal application of this model is to be documented in REV 02 of ''Engineered Barrier System: Physical and Chemical Environment Model'' (BSC 2003 [165601]). The scope of this document is to develop, describe, and validate the IDPS model. This model is a quasi-equilibrium model. All reactions proceed to equilibrium except for several suppressed minerals in the thermodynamic database not expected to form under the proposed repository conditions within the modeling timeframe. In this revision, upgrades to the EQ3/6 code (Version 8.0) and Pitzer thermodynamic database improve the applicable range of the model. These new additions allow equilibrium and reaction-path modeling of evaporation to highly concentrated brines for potential water compositions of the system Na-K-H-Mg-Ca-Al-Cl-F-NO{sub 3}-SO{sub 4}-Br-CO{sub 3}-SiO{sub 2}-CO{sub 2}-O{sub 2}-H{sub 2}O at temperatures in the range of 0 C to 125 C, pressures in the atmospheric range, and relative humidity in the range of 0 to 100 percent. This system applies to oxidizing conditions only, and therefore limits the model to applications involving oxidizing conditions. A number of thermodynamic parameters in the Pitzer database have values that have not been determined or verified for the entire temperature range. In these cases, the known values are used to approximate

  6. Does household access to improved water and sanitation in infancy and childhood predict better vocabulary test performance in Ethiopian, Indian, Peruvian and Vietnamese cohort studies?

    PubMed Central

    Dearden, Kirk A; Brennan, Alana T; Behrman, Jere R; Schott, Whitney; Crookston, Benjamin T; Humphries, Debbie L; Penny, Mary E; Fernald, Lia C H

    2017-01-01

    Objective Test associations between household water and sanitation (W&S) and children's concurrent and subsequent Peabody Picture Vocabulary Test (PPVT) scores. Design Prospective cohort study. Setting Ethiopia, India, Peru, Vietnam. Participants 7269 children. Primary outcome measures PPVT scores at 5 and 8 years. Key exposure variables were related to W&S, and collected at 1, 5 and 8 years, including ‘improved’ water (eg, piped, public tap or standpipe) and ‘improved’ toilets (eg, collection, storage, treatment and recycling of human excreta). Results Access to improved water at 1 year was associated with higher language scores at 5 years (3/4 unadjusted associations) and 8 years (4/4 unadjusted associations). Ethiopian children with access to improved water at 1 year had test scores that were 0.26 SD (95% CI 0.17 to 0.36) higher at 5 years than children without access. Access to improved water at 5 years was associated with higher concurrent PPVT scores (in 3/4 unadjusted associations), but not later scores (in 1/4 unadjusted associations). 5-year-old Peruvian children with access to improved water had better concurrent performance on the PPVT (0.44 SD, 95% CI 0.30 to 0.59) than children without access to improved water. Toilet access at 1 year was also associated with better PPVT scores at 5 years (3/4 unadjusted associations) and sometimes associated with test results at 8 years (2/4 unadjusted associations). Toilet access at 5 years was associated with concurrent PPVT scores (3/4 unadjusted associations). More than half of all associations in unadjusted models (water and toilets) persisted in adjusted models, particularly for toilets in India, Peru and Vietnam. Conclusions Access to ‘improved’ water and toilets had independent associations with children's PPVT scores that often persisted with adjustment for covariates. Our findings suggest that effects of W&S may go beyond subacute and acute infections and physical growth

  7. The GlueX central drift chamber: Design and performance

    SciTech Connect

    Van Haarlem, Y; Barbosa, F; Dey, B; Lawrence, D; Razmyslovich, V; Smith, Visser; Whitlatch, T; Wilkin, G; Zihlmann, B

    2010-10-01

    Tests and studies concerning the design and performance of the GlueX Central Drift Chamber (CDC) are presented. A full-scale prototype was built to test and steer the mechanical and electronic design. Small scale prototypes were constructed to test for sagging and to do timing and resolution studies of the detector. These studies were used to choose the gas mixture and to program a Monte Carlo simulation that can predict the detector response in an external magnetic field. Particle identification and charge division possibilities were also investigated.

  8. How Much Control Do Children and Adolescents Have over Genomic Testing, Parental Access to Their Results, and Parental Communication of Those Results to Others?

    PubMed

    Clayton, Ellen Wright

    2015-01-01

    Adolescents may often have opinions about whether they want genetic and genomic testing in both the clinic and research and about who should have access to the results. This legal analysis demonstrates that the law provides very little protection to minors' wishes.

  9. Nonlinear electrostatic drift Kelvin-Helmholtz instability

    NASA Technical Reports Server (NTRS)

    Sharma, Avadhesh C.; Srivastava, Krishna M.

    1993-01-01

    Nonlinear analysis of electrostatic drift Kelvin-Helmholtz instability is performed. It is shown that the analysis leads to the propagation of the weakly nonlinear dispersive waves, and the nonlinear behavior is governed by the nonlinear Burger's equation.

  10. Drift of continental rafts with asymmetric heating.

    PubMed

    Knopoff, L; Poehls, K A; Smith, R C

    1972-06-02

    A laboratory model of a lithospheric raft is propelled through a viscous asthenospheric layer with constant velocity of scaled magnitude appropriate to continental drift. The propulsion is due to differential heat concentration in the model oceanic and continental crusts.

  11. Self-shielding flex-circuit drift tube, drift tube assembly and method of making

    DOEpatents

    Jones, David Alexander

    2016-04-26

    The present disclosure is directed to an ion mobility drift tube fabricated using flex-circuit technology in which every other drift electrode is on a different layer of the flex-circuit and each drift electrode partially overlaps the adjacent electrodes on the other layer. This results in a self-shielding effect where the drift electrodes themselves shield the interior of the drift tube from unwanted electro-magnetic noise. In addition, this drift tube can be manufactured with an integral flex-heater for temperature control. This design will significantly improve the noise immunity, size, weight, and power requirements of hand-held ion mobility systems such as those used for explosive detection.

  12. Effects of Fault Displacement on Emplacement Drifts

    SciTech Connect

    F. Duan

    2000-04-25

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10{sup -5} adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M&O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure.

  13. Assessment of HF Drift Data Reliability

    DTIC Science & Technology

    2005-06-13

    the array, making the beamforming computations very efficient. The station can operate in four different modes: 1) Scanning ionogram , 2) Drift ionogram ...3) Fixed Frequency ionogram 4) Oblique ionogram . Real-time ionograms with the results of their automatic scaling and the history of past soundings...are currently available on the official web site of Athens Digisonde (http://www.iono.noa.gr). For the post-processing of the drift ionogram , the

  14. Performance of Thin-Window Silicon Drift Detectors

    SciTech Connect

    Carini, , G.A.; Chen, W.; De Geronimo, G.; Fried, J.; Gaskin, J.A.; Keister; J.W.; Li, Z.; Ramsey, B.D.; Rehak, P.; Siddons, D.P.

    2008-10-20

    Several sets of hexagonal Silicon Drift Detector (SDD) arrays were produced at BNL and by a commercial vendor, KETEK. Each array consists of 14 independent detectors (pixels) and two additional test pixels at two of the corners. The side of the detector upon which the X-ray radiation is incident (window side) has a thin junction covering the entire active area. The opposite side (device side) contains a drift-field electrode structure in the form of a hexagonal spiral and an electron collecting anode. There are 4 guard rings surrounding the 14-pixel array area on both sides of the detector. Within each array, 7 of the pixels have an aluminum field plate - interrupted spirals that stabilize the electric potential under the Si-SiO2 interface, while the other 7 do not. The drift field in the silicon volume is controlled by three biases: one is applied to a rectifying contact, one to the detector entrance window, and the third to a contact on the outer portion of the spiral common to all pixels in the array. Some arrays have been newly measured in NSLS beam line U3C at BNL. The complete assemblies were installed in the vacuum and cooled to ?27 C. During this run, spectra for energies ranging between 400 and 900 eV were collected in several pixels, some with field plates and others without. The detailed testing results of several arrays are reported here.

  15. Thermodynamics Insights for the Redshift Drift

    NASA Astrophysics Data System (ADS)

    Zhang, Ming-Jian; Liu, Wen-Biao

    2015-01-01

    The secular redshift drift is a potential measurement to directly probe the cosmic expansion. Previous study on the redshift drift mainly focused on the model-dependent simulation. Apparently, the physical insights on the redshift drift are very necessary. So in this paper, it is investigated using thermodynamics on the apparent, Hubble and event horizons. Thermodynamics could analytically present the model-independent upper bounds of redshift drift. For specific assumption on the cosmological parameters, we find that the thermodynamics bounds are nearly one order of magnitude larger than the expectation in standard ΛCDM model. We then examine ten observed redshift drift from Green Bank Telescope at redshift 0.09 < z < 0.69, and find that these observational results are inconsistent with the thermodynamics. The size of the errorbars on these measurements is about three orders of magnitude larger than the effect of thermodynamical bounds for the redshift drift. Obviously, we have not yet hit any instrumental systematics at the shift level of 1m s-1 yr-1.

  16. Point set registration: coherent point drift.

    PubMed

    Myronenko, Andriy; Song, Xubo

    2010-12-01

    Point set registration is a key component in many computer vision tasks. The goal of point set registration is to assign correspondences between two sets of points and to recover the transformation that maps one point set to the other. Multiple factors, including an unknown nonrigid spatial transformation, large dimensionality of point set, noise, and outliers, make the point set registration a challenging problem. We introduce a probabilistic method, called the Coherent Point Drift (CPD) algorithm, for both rigid and nonrigid point set registration. We consider the alignment of two point sets as a probability density estimation problem. We fit the Gaussian mixture model (GMM) centroids (representing the first point set) to the data (the second point set) by maximizing the likelihood. We force the GMM centroids to move coherently as a group to preserve the topological structure of the point sets. In the rigid case, we impose the coherence constraint by reparameterization of GMM centroid locations with rigid parameters and derive a closed form solution of the maximization step of the EM algorithm in arbitrary dimensions. In the nonrigid case, we impose the coherence constraint by regularizing the displacement field and using the variational calculus to derive the optimal transformation. We also introduce a fast algorithm that reduces the method computation complexity to linear. We test the CPD algorithm for both rigid and nonrigid transformations in the presence of noise, outliers, and missing points, where CPD shows accurate results and outperforms current state-of-the-art methods.

  17. Risk evaluation of drift from 40 aerially-applied herbicides on fish production pond plankton and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Row crop herbicides were tested for possible adverse effects on pond plankton and water quality in triplicate 500-L outdoor, pool mesocosms. Treatments were drift at low (1% of full field rates) and high levels (10% of the full rate) to production ponds of 5 ha and large, and no drift (control). H...

  18. Mesh-size effects on drift sample composition as determined with a triple net sampler

    USGS Publications Warehouse

    Slack, K.V.; Tilley, L.J.; Kennelly, S.S.

    1991-01-01

    Nested nets of three different mesh apertures were used to study mesh-size effects on drift collected in a small mountain stream. The innermost, middle, and outermost nets had, respectively, 425 ??m, 209 ??m and 106 ??m openings, a design that reduced clogging while partitioning collections into three size groups. The open area of mesh in each net, from largest to smallest mesh opening, was 3.7, 5.7 and 8.0 times the area of the net mouth. Volumes of filtered water were determined with a flowmeter. The results are expressed as (1) drift retained by each net, (2) drift that would have been collected by a single net of given mesh size, and (3) the percentage of total drift (the sum of the catches from all three nets) that passed through the 425 ??m and 209 ??m nets. During a two day period in August 1986, Chironomidae larvae were dominant numerically in all 209 ??m and 106 ??m samples and midday 425 ??m samples. Large drifters (Ephemerellidae) occurred only in 425 ??m or 209 ??m nets, but the general pattern was an increase in abundance and number of taxa with decreasing mesh size. Relatively more individuals occurred in the larger mesh nets at night than during the day. The two larger mesh sizes retained 70% of the total sediment/detritus in the drift collections, and this decreased the rate of clogging of the 106 ??m net. If an objective of a sampling program is to compare drift density or drift rate between areas or sampling dates, the same mesh size should be used for all sample collection and processing. The mesh aperture used for drift collection should retain all species and life stages of significance in a study. The nested net design enables an investigator to test the adequacy of drift samples. ?? 1991 Kluwer Academic Publishers.

  19. Wind selectivity and partial compensation for wind drift among nocturnally migrating passerines

    PubMed Central

    McLaren, James D.

    2012-01-01

    A migrating bird’s response to wind can impact its timing, energy expenditure, and path taken. The extent to which nocturnal migrants select departure nights based on wind (wind selectivity) and compensate for wind drift remains unclear. In this paper, we determine the effect of wind selectivity and partial drift compensation on the probability of successfully arriving at a destination area and on overall migration speed. To do so, we developed an individual-based model (IBM) to simulate full drift and partial compensation migration of juvenile Willow Warblers (Phylloscopus trochilus) along the southwesterly (SW) European migration corridor to the Iberian coast. Various degrees of wind selectivity were tested according to how large a drift angle and transport cost (mechanical energy per unit distance) individuals were willing to tolerate on departure after dusk. In order to assess model results, we used radar measurements of nocturnal migration to estimate the wind selectivity and proportional drift among passerines flying in SW directions. Migration speeds in the IBM were highest for partial compensation populations tolerating at least 25% extra transport cost compared to windless conditions, which allowed more frequent departure opportunities. Drift tolerance affected migration speeds only weakly, whereas arrival probabilities were highest with drift tolerances below 20°. The radar measurements were indicative of low drift tolerance, 25% extra transport cost tolerance and partial compensation. We conclude that along migration corridors with generally nonsupportive winds, juvenile passerines should not strictly select supportive winds but partially compensate for drift to increase their chances for timely and accurate arrival. PMID:22936843

  20. WINCS v.2 for the Neutral Wind and Ion-drift in the Thermosphere/Ionosphere

    NASA Astrophysics Data System (ADS)

    Herrero, F. A.; Nicholas, A. C.

    2013-12-01

    The Wind Ion-drift Neutral Composition Suite (WINCS) has been updated to increase sensitivity to wind/ion-drift change and to further reduce risk and cost. Description of the new neutral wind/ion-drift spectrometer component of WINCS will be given with data results from simulations and laboratory tests of WINCS version 2. A 20-fold increase in wind/ion-drift sensitivity brings their uncertainties to about × 0.5 m/s; corresponding to a pointing uncertainty of × 0.005°. This precision improves accuracy in the wind/ion-drift when used with new star cameras that provide ×0.005° or better pointing accuracy; thus allowing vertical wind and vertical ion-drift measurements over broad regions of the upper atmosphere. The new design uses a larger aperture (0.1cm diameter instead of the 0.02cm diameter of WINCS v.1), and replaces the energy-scanning energy analyzer with a 30° PPA (parallel plate analyzer) energy spectrograph that simultaneously measures all energies of interest. These two features increase the signal to enable the new wind/ion-drift precisions stated above. Risk and cost reduction follow from the new electro-mechanical format that combines spectrometer mechanical mounting with the actual electrical connection. The presentation will close with discussion of cross-track and in-track wind and ion-drift components to emphasize the requirement of the energy analyzer in obtaining the magnitude of the total velocity in both cross-track and in-track winds and ion-drifts - that is, the total velocity of the neutrals or ions incident upon WINCS.

  1. Effect of sprayer settings on spray drift during pesticide application in poplar plantations (Populus spp.).

    PubMed

    Grella, Marco; Marucco, Paolo; Manzone, Marco; Gallart, Montserrat; Balsari, Paolo

    2017-02-01

    This study assessed spray drift generated by sprayer settings commonly used for pesticide application in poplar plantations (Populus spp.). Tests were conducted per the ISO 22866 methodology using a mounted air-assisted sprayer (Tifone VRP600) equipped with a swivel-cannon air conveyor (model Cannone 50S). Trials evaluated sprayer settings, combinations of nozzle types, airflow rates, and air direction in both adult and young poplar plantations. Overall, spray drift amounts registered downwind of poplar plantations were less than those obtained to derive reference drift curves during the EU Plant Protection Product registration process that used late-growth-stage fruit crops. In the adult poplar plantation, Venturi nozzles (TVI 8004 red) yielded the highest drift reductions compared to reference sprayer setting, especially at distances farthest from the sprayed area (86% between 40 and 47m). Highest total drift reductions were achieved when conventional nozzles (1.81mm ceramic disc-core) were combined with their spray direction modified for an inclined cannon spray unit. Alternatively, the young poplar plantation showed no drift reduction for distances farthest from the sprayed area, regardless of sprayer settings, which likely resulted from lower foliage density and widely-spaced rows. Yet, both Venturi nozzles combined with high fan flow rates and conventional nozzles combined with reduced fan flow rate showed total spray drift reductions of over 70% within the downwind sampling area. These experimental results represent the first set of data on spray drift amounts in poplar plantations, which is key for defining the reference curves and best practices to reduce spray drift in tall tree plantations.

  2. AN IMPLICIT"DRIFT-LORENTZ" PARTICLE MOVER FOR PLASMA AND BEAM SIMULATIONS

    SciTech Connect

    Friedman, A.; Grote, D.P.; Vay, J.-L; Cohen, R.H.

    2008-07-15

    In order to efficiently perform particle simulations in systems with widely varying magnetization, we developed a drift-Lorentz mover, which interpolates between full particle dynamics and drift kinetics in such a way as to preserve a physically correct gyroradius and particle drifts for both large and small ratios of the timestep to the cyclotron period. In order to extend applicability of the mover to systems with plasma frequency exceeding the cyclotron frequency such as one may have with fully neutralized drift compression of a heavy-ion beam we have developed an implicit version of the mover. A first step in this direction, in which the polarization charge was added to the field solver, was described previously. Here we describe a fully implicit algorithm (which is analogous to the direct-implicit method for conventionalparticle-in-cell simulation), summarize a stability analysis of it, and describe several tests of the resultant code.

  3. An Implicit "Drift-Lorentz" Mover for Plasma and Beam Simulations

    SciTech Connect

    Cohen, R H; Friedman, A; Grote, D P; Vay, J

    2009-02-12

    In order to efficiently perform particle simulations in systems with widely varying magnetization, we developed a drift-Lorentz mover, which interpolates between full particle dynamics and drift kinetics in such a way as to preserve a physically correct gyroradius and particle drifts for both large and small ratios of the timestep to the cyclotron period. In order to extend applicability of the mover to systems with plasma frequency exceeding the cyclotron frequency such as one may have with fully neutralized drift compression of a heavy-ion beam we have developed an implicit version of the mover. A first step in this direction, in which the polarization charge was added to the field solver, was described previously. Here we describe a fully implicit algorithm (which is analogous to the direct-implicit method for conventional particle-in-cell simulation), summarize a stability analysis of it, and describe several tests of the resultant code.

  4. Gradient Drift Instabilities in Two Dimensional Hybrid Hall Thruster Simulations

    NASA Astrophysics Data System (ADS)

    Aley, Jacob; Dowdy, Caleb; Fernandez, Eduardo

    2014-10-01

    Instabilities triggered by a variety of mechanisms have been theoretically predicted for Hall thruster plasmas. Experimentally, fluctuations spanning a wide range of frequencies and wave numbers have been observed. Perhaps more importantly, fluctuations have been postulated to play a role in regulating cross-field electron transport in Hall thrusters. However, a clear understanding of what instabilities are responsible for such transport is presently lacking. In this work we focus on analysis of long wavelength gradient drift instability in the Hall thruster via two dimensional hybrid fluid-PIC simulations that resolve azimuthal dynamics. Recent theoretical analysis by Frias et al. shows that previous stability criteria for drift instabilities are modified due to compressibility of the electron flow. In our simulations, we test this improved criterion by examining the transient waves that emerge in the simulation from a smooth initial condition. The simulations give good agreement with the theory, both in the frequency/growth rate characteristics of the waves as well as the region of the thruster where such disturbances are predicted to emerge. These results suggest that gradient drift instabilities play a significant role in Hall thruster plasmas. Jacob Aley, Caleb Dowdy, and Eduardo Fernandez are supported by a grant from the II-VI Foundation.

  5. Measurements verifying the optics of the Electron Drift Instrument

    NASA Astrophysics Data System (ADS)

    Kooi, Vanessa M.

    This thesis concentrates on laboratory measurements of the Electron Drift Instrument (EDI), focussing primarily on the EDI optics of the system. The EDI is a device used on spacecraft to measure electric fields by emitting an electron beam and measuring the E x B drift of the returning electrons after one gyration. This drift velocity is determined using two electron beams directed perpendicular to the magnetic field returning to be detected by the spacecraft. The EDI will be used on the Magnetospheric Multi-Scale Mission. The EDI optic's testing process takes measurements of the optics response to a uni-directional electron beam. These measurements are used to verify the response of the EDI's optics and to allow for the optimization of the desired optics state via simulation. The optics state tables were created in simulations and we are using these measurements to confirm their accuracy. The setup consisted of an apparatus made up of the EDI's optics and sensor electronics was secured to the two axis gear arm inside a vacuum chamber. An electron beam was projected at the apparatus which then used the EDI optics to focus the beam into the micro-controller plates and onto the circular 32 pad annular ring that makes up the sensor. The concentration of counts per pad over an interval of 1ms were averaged over 25 samples and plotted in MATLAB. The results of the measurements plotted agreed well with the simulations, providing confidence in the EDI instrument.

  6. Optimality and stability of intentional and unintentional actions: I. Origins of drifts in performance.

    PubMed

    Parsa, Behnoosh; Terekhov, Alexander; Zatsiorsky, Vladimir M; Latash, Mark L

    2017-02-01

    We address the nature of unintentional changes in performance in two papers. This first paper tested a hypothesis that unintentional changes in performance variables during continuous tasks without visual feedback are due to two processes. First, there is a drift of the referent coordinate for the salient performance variable toward the actual coordinate of the effector. Second, there is a drift toward minimum of a cost function. We tested this hypothesis in four-finger isometric pressing tasks that required the accurate production of a combination of total moment and total force with natural and modified finger involvement. Subjects performed accurate force-moment production tasks under visual feedback, and then visual feedback was removed for some or all of the salient variables. Analytical inverse optimization was used to compute a cost function. Without visual feedback, both force and moment drifted slowly toward lower absolute magnitudes. Over 15 s, the force drop could reach 20% of its initial magnitude while moment drop could reach 30% of its initial magnitude. Individual finger forces could show drifts toward both higher and lower forces. The cost function estimated using the analytical inverse optimization reduced its value as a consequence of the drift. We interpret the results within the framework of hierarchical control with referent spatial coordinates for salient variables at each level of the hierarchy combined with synergic control of salient variables. The force drift is discussed as a natural relaxation process toward states with lower potential energy in the physical (physiological) system involved in the task.

  7. Drift emplaced waste package thermal response

    SciTech Connect

    Ruffner, D.J.; Johnson, G.L.; Platt, E.A.; Blink, J.A.; Doering, T.W.

    1993-01-01

    Thermal calculations of the effects of radioactive waste decay heat on the I repository at Yucca Mountain, Nevada have been conducted by the Yucca Mountain Site Characterization Project (YMP) at Lawrence Livermore National Laboratory (LLNL) in conjunction with the B&W Fuel Company. For a number of waste package spacings, these 3D transient calculations use the TOPAZ3D code to predict drift wall temperatures to 10,000 years following emplacement. Systematic tcniperature variation occurs as a function of fuel age at emplacement and Areal Mass Loading (AML) during the first few centuries after emplacement. After about 1000 years, emplacement age is not a strong driver on rock temperature; AML has a larger impact. High AMLs occur when large waste packages are emplaced end-tocnd in drifts. Drift emplacement of equivalent packages results in lower rock teniperatures than borehole emplacement. For an emplacement scheme with 50% of the drift length occupied by packages, an AML of 138 MTU/acre is about three times higher than the Site Characterization Plan-Conceptual Design (SCP-CD) value. With this higher AML (requiring only 1/3 of the SCP-CD repository footprint), peak drift wall temperatures do not exceed 160*C, but rock temperatures excetd the boiling point of water for about 3000 years. These TOPAZ3D results Iiive been compared with reasonable agreement with two other computer codes.

  8. Drift emplaced waste package thermal response

    SciTech Connect

    Ruffner, D.J.; Johnson, G.L.; Platt, E.A.; Blink, J.A.; Doering, T.W.

    1993-12-31

    Thermal calculations of the effects of radioactive waste decay heat on the potential repository at Yucca Mountain, Nevada, have been conducted by the Yucca Mountain Site Characterization Project (YMP) at Lawrence Livermore National Lab. (LLNL) in conjunction with the B&W Fuel Co. For a number of waste package spacings, these 3D transient calculations use the TOPAZ3D code to predict drift wall temperatures to 10,000 years following emplacement. Systematic temperature variation occurs as a function of fuel age at emplacement and Areal Mass Loading (AML) during the first few centuries after emplacement. After about 1000 years, emplacement age is not a strong driver on rock temperature; AML has a larger impact. High AMLs occur when large waste packages are emplaced end-to-end in drifts. Drift emplacement of equivalent packages results in lower rock temperatures than borehole emplacement. For an emplacement scheme with 50% of the drift length occupied by packages, an AML of 138 MTU/acre is about three times higher than the Site Characterization Plan-Conceptual Design (SCP-CD) value. With this higher AML (requiring only 1/3 of the SCP-CD repository footprint), peak drift wall temperatures do not exceed 160{degrees}C, but rock temperatures exceed the boiling point of water for about 3000 years. These TOPAZ3D results have been compared with reasonable agreement with two other computer codes.

  9. Confronting the "Acid Test": Educators' Perspectives on Expanding Access to Advanced Placement at a Diverse Florida High School

    ERIC Educational Resources Information Center

    Rowland, M. Lance; Shircliffe, Barbara J.

    2016-01-01

    This study examines educators' perspectives on accountability mandates designed to expand access to the College Board's Advanced Placement (AP) classes to traditionally underserved students at a diverse suburban high school in Florida, Palm Crest High School. Consistent with Elmore (1979), district and site-based administrators focused on the…

  10. Web Site Usability Testing Involving People with Learning Disabilities Using Only Images and Audio to Access Information

    ERIC Educational Resources Information Center

    Williams, Peter

    2013-01-01

    The need for social inclusion, informed choice and the facilitation of independent living for people with learning disabilities (LD) is being emphasised ever more by government, professionals, academics and, indeed, by people with LD themselves, particularly in self-advocacy groups. Achieving goals around inclusion and autonomy requires access to…

  11. Comparison of Vertical Drifts of ISR and Magnetometer Data Measurements at the Magnetic Equator

    NASA Astrophysics Data System (ADS)

    Condor P, P. J.

    2014-12-01

    We compare vertical drifts measured with the Jicamarca incoherent scatter radar (ISR) and drifts estimated from magnetometer data applying a Neural Network data processing technique. For the application of the Neural Network (NN) method, we use the magnitude of the horizontal (H) component of the magnetic field measured with magnetometers at Jicamarca and Piura (Peru). The data was collected between the years 2002 and 2013. In training the NN we use the difference between the magnitudes of the horizontal components (dH) measured at JRO (placed at the magnetic equator) and Piura (displaced 5° away). Additional parameters used are F10.7 and Ap indexes. The estimates obtained with the NN procedure are very good. We have an RMS error of 3.7 m/s using dH as an input of the NN while the error is 3.9 m/s when we use the component H of JRO as an input. The results are validated using the set of vertical drifts observations collected with the Jicamarca incoherent scatter radar. The estimated drifts can be accessed using the following website: http://jro.igp.gob.pe/driftnn. In the poster, we show the comparison of vertical drifts from 2002 to 2013 where we discuss the agreement between magnetometer and ISR data.

  12. Dealing with concept drifts in process mining.

    PubMed

    Bose, R P Jagadeesh Chandra; van der Aalst, Wil M P; Zliobaite, Indre; Pechenizkiy, Mykola

    2014-01-01

    Although most business processes change over time, contemporary process mining techniques tend to analyze these processes as if they are in a steady state. Processes may change suddenly or gradually. The drift may be periodic (e.g., because of seasonal influences) or one-of-a-kind (e.g., the effects of new legislation). For the process management, it is crucial to discover and understand such concept drifts in processes. This paper presents a generic framework and specific techniques to detect when a process changes and to localize the parts of the process that have changed. Different features are proposed to characterize relationships among activities. These features are used to discover differences between successive populations. The approach has been implemented as a plug-in of the ProM process mining framework and has been evaluated using both simulated event data exhibiting controlled concept drifts and real-life event data from a Dutch municipality.

  13. Drift due to viscous vortex rings

    NASA Astrophysics Data System (ADS)

    Morrell, Thomas; Spagnolie, Saverio; Thiffeault, Jean-Luc

    2016-11-01

    Biomixing is the study of fluid mixing due to swimming organisms. While large organisms typically produce turbulent flows in their wake, small organisms produce less turbulent wakes; the main mechanism of mixing is the induced net particle displacement (drift). Several experiments have examined this drift for small jellyfish, which produce vortex rings that trap and transport a fair amount of fluid. Inviscid theory implies infinite particle displacements for the trapped fluid, so the effect of viscosity must be included to understand the damping of real vortex motion. We use a model viscous vortex ring to compute particle displacements and other relevant quantities, such as the integrated moments of the displacement. Fluid entrainment at the tail end of a growing vortex 'envelope' is found to play an important role in the total fluid transport and drift. Partially supported by NSF Grant DMS-1109315.

  14. EMPLACEMENT DRIFT INVERT-LOW STEEL EVALUATION

    SciTech Connect

    M. E. Taylor and D. H. Tang

    2000-09-29

    This technical report evaluates and develops options for reducing the amount of steel in the emplacement drift invert. Concepts developed in the ''Invert Configuration and Drip Shield Interface'' were evaluated to determine material properties required for the proposed invert concepts. Project requirements documents prescribe the use of a carbon steel frame for the invert with a granular material of crushed tuff as ballast. The ''Invert Configuration and Drip Shield Interface'' developed three concepts: (1) All-Ballast Invert; (2) Modified Steel Invert with Ballast; and (3) Steel Tie with Ballast Invert. Analysis of the steel frame members, runway beams, and guide beams, for the modified steel invert with ballast, decreased the quantity of steel in the emplacement drift invert, however a substantial steel support frame for the gantry and waste package/pallet assembly is still required. Use of one of the other two concepts appears to be an alternative to the steel frame and each of the concepts uses considerably less steel materials. Analysis of the steel tie with ballast invert shows that the bearing pressure on the ballast under the single steel tie, C 9 x 20, loaded with the waste package/pallet assembly, drip shield, and backfill exceeds the upper bound of the allowable bearing capacity for tuff used in this study. The single tie, C 10 x 20, will also fail for the same loading condition except for the tie length of 4.2 meters and longer. Analysis also shows that with two ties, C 9 or 10 x 20's, the average ballast pressure is less than the allowable bearing capacity. Distributing the waste package/pallet, drip shield, and backfill loads to two steel ties reduces the contact bearing pressure. Modifying the emplacement pallet end beams to a greater width, reducing the tie spacing, and increasing the width of the ties would ensure that the pallet beams are always supported by two steel ties. Further analysis is required to determine compatible tie size and spacing

  15. Expanding Access to Non-Medicalized Community-Based Rapid Testing to Men Who Have Sex with Men: An Urgent HIV Prevention Intervention (The ANRS-DRAG Study)

    PubMed Central

    Lorente, Nicolas; Preau, Marie; Vernay-Vaisse, Chantal; Mora, Marion; Blanche, Jerome; Otis, Joanne; Passeron, Alain; Le Gall, Jean-Marie; Dhotte, Philippe; Carrieri, Maria Patrizia; Suzan-Monti, Marie; Spire, Bruno

    2013-01-01

    Background Little is known about the public health benefits of community-based, non-medicalized rapid HIV testing offers (CBOffer) specifically targeting men who have sex with men (MSM), compared with the standard medicalized HIV testing offer (SMOffer) in France. This study aimed to verify whether such a CBOffer, implemented in voluntary counselling and testing centres, could improve access to less recently HIV-tested MSM who present a risk behaviour profile similar to or higher than MSM tested with the SMOffer. Method This multisite study enrolled MSM attending voluntary counselling and testing centres’ during opening hours in the SMOffer. CBOffer enrolees voluntarily came to the centres outside of opening hours, following a communication campaign in gay venues. A self-administered questionnaire was used to investigate HIV testing history and sexual behaviours including inconsistent condom use and risk reduction behaviours (in particular, a score of “intentional avoidance” for various at-risk situations was calculated). A mixed logistic regression identified factors associated with access to the CBOffer. Results Among the 330 participants, 64% attended the CBOffer. Percentages of inconsistent condom use in both offers were similar (51% CBOffer, 50% SMOffer). In multivariate analyses, those attending the CBOffer had only one or no test in the previous two years, had a lower intentional avoidance score, and met more casual partners in saunas and backrooms than SMOffer enrolees. Conclusion This specific rapid CBOffer attracted MSM less recently HIV-tested, who presented similar inconsistent condom use rates to SMOffer enrolees but who exposed themselves more to HIV-associated risks. Increasing entry points for HIV testing using community and non-medicalized tests is a priority to reach MSM who are still excluded. PMID:23613817

  16. A multifactorial test of the effects of carotenoid access, food intake and parasite load on the production of ornamental feathers and bill coloration in American goldfinches.

    PubMed

    Hill, Geoffrey E; Hood, Wendy R; Huggins, Kristal

    2009-04-01

    It has been well established that carotenoid and melanin pigmentation are often condition-dependent traits in vertebrates. Expression of carotenoid coloration in birds has been shown to reflect pigment intake, food access and parasite load; however, the relative importance of and the potential interactions among these factors have not been previously considered. Moreover, carotenoid and melanin pigmentation have been proposed to signal fundamentally different aspects of individual condition but few data exist to test this idea. We simultaneously manipulated three environmental conditions under which American goldfinches (Cardeulis tristis) grew colorful feathers and developed carotenoid pigmentation of their bills. Male goldfinches were held with either high or low carotenoid supplementation, pulsed or continuous antimicrobial drug treatment, or restricted or unlimited access to food. Carotenoid supplementation had an overriding effect on yellow feather coloration. Males given more lutein and zeaxanthin grew yellow feathers with hue shifted toward orange and with higher yellow chroma than males supplemented with fewer carotenoids. Parasites and food access did not significantly affect yellow feather coloration, and there were only minor interaction effects for the three treatments. By contrast, bill coloration was significantly affected by all three treatments. Carotenoid supplementation had a significant effect on yellow chroma of bills, drug treatment and food access both had a significant effect on bill hue, and food access had a significant effect on the yellow brightness of bills. Neither the size nor blackness of the black caps of male goldfinches was affected by any treatment. These results indicate that pigment intake, food access and parasite load can have complex and variable effects on color displays, and that feather and bill coloration signal different aspects of male condition.

  17. The Legal Past, Present and Future of Prenatal Genetic Testing: Professional Liability and Other Legal Challenges Affecting Patient Access to Services.

    PubMed

    Pergament, Deborah; Ilijic, Katie

    2014-12-15

    This chapter is an overview of the current status of the law in the United States regarding prenatal genetic testing with an emphasis on issues related to professional liability and other challenges affecting patient access to prenatal genetic testing. The chapter discusses the roles that federal regulations, promulgated by the Centers for Medicare and Medicaid Services (CMS), the Food and Drug Administration (FDA) and the Federal Trade Commission (FTC), play in the regulation of prenatal genetic tests. The chapter discusses tort litigation based on allegations of malpractice in the provision of prenatal genetic testing and how courts have analyzed issues related to causation, damages and mitigation of damages. The chapter provides reference information regarding how individual states address causes of action under the tort theories of wrongful birth and wrongful life. The chapter concludes with a discussion of future legal issues that may affect clinical prenatal genetic testing services arising from the continued expansion of prenatal genetic testing, legal restrictions on access to abortion and the potential development of embryonic treatments.

  18. The Legal Past, Present and Future of Prenatal Genetic Testing: Professional Liability and Other Legal Challenges Affecting Patient Access to Services

    PubMed Central

    Pergament, Deborah; Ilijic, Katie

    2014-01-01

    This chapter is an overview of the current status of the law in the United States regarding prenatal genetic testing with an emphasis on issues related to professional liability and other challenges affecting patient access to prenatal genetic testing. The chapter discusses the roles that federal regulations, promulgated by the Centers for Medicare and Medicaid Services (CMS), the Food and Drug Administration (FDA) and the Federal Trade Commission (FTC), play in the regulation of prenatal genetic tests. The chapter discusses tort litigation based on allegations of malpractice in the provision of prenatal genetic testing and how courts have analyzed issues related to causation, damages and mitigation of damages. The chapter provides reference information regarding how individual states address causes of action under the tort theories of wrongful birth and wrongful life. The chapter concludes with a discussion of future legal issues that may affect clinical prenatal genetic testing services arising from the continued expansion of prenatal genetic testing, legal restrictions on access to abortion and the potential development of embryonic treatments. PMID:26237611

  19. Drift Mode Calculations in Nonaxisymmetric Geometry

    SciTech Connect

    G. Rewoldt; L.-P. Ku; W.A. Cooper; W.M. Tang

    1999-07-01

    A fully kinetic assessment of the stability properties of toroidal drift modes has been obtained for nonaxisymmetric (stellarator) geometry, in the electrostatic limit. This calculation is a comprehensive solution of the linearized gyrokinetic equation, using the lowest-order ''ballooning representation'' for high toroidal mode number instabilities, with a model collision operator. Results for toroidal drift waves destabilized by temperature gradients and/or trapped particle dynamics are presented, using three-dimensional magnetohydrodynamic equilibria generated as part of a design effort for a quasiaxisymmetric stellarator. Comparisons of these results with those obtained for typical tokamak cases indicate that the basic trends are similar.

  20. Generalized Drift-Diffusion Model In Semiconductors

    SciTech Connect

    Mesbah, S.; Bendib-Kalache, K.; Bendib, A.

    2008-09-23

    A new drift-diffusion model is proposed based on the computation of the stationary nonlocal current density. The semi classical Boltzmann equation is solved keeping all the anisotropies of the distribution function with the use of the continued fractions. The conductivity is calculated in the linear approximation and for arbitrary collision frequency with respect to Kv{sub t} where K{sup -1} is the characteristic length scale of the system and V{sub t} is the thermal velocity. The nonlocal conductivity can be used to close the generalized drift-diffusion equations valid for arbitrary collisionality.

  1. Aging and epigenetic drift: a vicious cycle.

    PubMed

    Issa, Jean-Pierre

    2014-01-01

    The term epigenetics refers to stable patterns of gene expression that are seen during differentiation or X chromosome inactivation and are not dependent on dynamic changes in coding DNA. These gene expression states are encoded in the epigenome - a collection of marks on DNA or on histone tails that are established during embryogenesis. Genome-wide studies in aging cells and tissues have uncovered stochastic DNA methylation drift (gradual increases or decreases at specific loci) that reflects imperfect maintenance of epigenetic marks. Drift creates epigenetic mosaicism in aging stem cells that could potentially restrict their plasticity and worsen phenotypes such as stem cell exhaustion and focal proliferative defects that can lead to cancer.

  2. Drifts of Dust or Something Else?

    NASA Technical Reports Server (NTRS)

    2004-01-01

    While the interior and far walls of the crater dubbed 'Bonneville' can be seen in the background, the dominant foreground features in this 180-degree navigation camera mosaic are the wind-deposited drifts of dust or sand. NASA's Mars Exploration Rover Spirit completed this mosaic on sol 71, March 15, 2004, from its newest location at the rim of 'Bonneville' crater.

    Scientists are interested in these formations in part because they might give insight into the processes that formed some of the material within the crater. Thermal emission measurements by the rover indicate that the dark material just below the far rim of this crater is spectrally similar to rocks that scientists have analyzed along their journey to this location. They want to know why this soil-like material has a spectrum that more closely resembles rocks rather than other soils examined so far. The drifts seen in the foreground of this mosaic might have the answer. Scientists hypothesize that these drifts might consist of wind-deposited particles that are the same as the dark material found against the back wall of the crater. If so, Spirit may spend time studying the material and help scientists understand why it is different from other fine-grained material seen at Gusev.

    The drifts appear to be lighter in color than the dark material deposited on the back wall of the crater. They might be covered by a thin deposit of martian dust, or perhaps the drift is like other drifts seen during Spirit's journey and is just a collection of martian dust.

    To find out, Spirit will spend some of sol 72 digging its wheels into the drift to uncover its interior. After backing up a bit, Spirit will use the panoramic camera and miniature thermal emission spectrometer to analyze the scuffed area. If the interior material has a similar spectrum to the dark deposit in the crater, then Spirit will most likely stay here a little longer to study the drift with the instruments on its robotic arm. If the

  3. Continental drift under the Third Reich.

    PubMed

    Buffetaut, Eric

    2003-12-01

    Contrary to what happened in many other countries in the 1930s and 1940s, Alfred Wegener's theory of continental drift was not generally rejected in Nazi Germany, although several leading German geologists of the time did not accept it. It was actually presented as the modern view of Earth history in books and magazine articles aimed at the general public. Although outlandish geological theories such as Hörbiger's Welteislehre were favoured by some Nazi dignitaries, they were not widely accepted in scientific circles. On the other hand, continental drift received official support under the Third Reich, at a time when it was ignored or ridiculed by most earth scientists outside Germany.

  4. Do the pyramids show continental drift?

    PubMed

    Pawley, G S; Abrahamsen, N

    1973-03-02

    The mystery of the orientation of the Great Pyramids of Giza has remained unexplained for many decades. The general alignment is 4 minutes west of north. It is argued that this is not a builders' error but is caused by movement over the centuries. Modern theories of continental drift do not predict quite such large movements, but other causes of polar wandering give even smaller shifts. Thus, continental drift is the most likely explanation, although somewhat implausible, especially as relevant measurements have been made over a 50-year period, whereas geophysical measurements of sea-floor spreading relate to million-year time scales.

  5. Small-scale lacustrine drifts in Lake Champlain, Vermont

    USGS Publications Warehouse

    Manley, Patricia L.; Manley, T.O.; Hayo, Kathryn; Cronin, Thomas

    2012-01-01

    High resolution CHIRP (Compressed High Intensity Radar Pulse) seismic profiles reveal the presence of two lacustrine sediment drifts located in Lake Champlain's Juniper Deep. Both drifts are positive features composed of highly laminated sediments. Drift B sits on a basement high while Drift A is built on a trough-filling acoustically-transparent sediment unit inferred to be a mass-transport event. These drifts are oriented approximately north–south and are parallel to a steep ridge along the eastern shore of the basin. Drift A, located at the bottom of a structural trough, is classified as a confined, elongate drift that transitions northward to become a system of upslope asymmetric mudwaves. Drift B is perched atop a structural high to the west of Drift A and is classified as a detached elongate drift. Bottom current depositional control was investigated using Acoustic Doppler Current Profilers (ADCPs) located across Drift A. Sediment cores were taken at the crest and at the edges of the Drift A and were dated. Drift source, deposition, and evolution show that these drifts are formed by a water column shear with the highest deposition occurring along its crest and western flank and began developing circa 8700–8800 year BP.

  6. Use of a Terrestrial LIDAR Sensor for Drift Detection in Vineyard Spraying

    PubMed Central

    Gil, Emilio; Llorens, Jordi; Llop, Jordi; Fàbregas, Xavier; Gallart, Montserrat

    2013-01-01

    The use of a scanning Light Detection and Ranging (LIDAR) system to characterize drift during pesticide application is described. The LIDAR system is compared with an ad hoc test bench used to quantify the amount of spray liquid moving beyond the canopy. Two sprayers were used during the field test; a conventional mist blower at two air flow rates (27,507 and 34,959 m3·h−1) equipped with two different nozzle types (conventional and air injection) and a multi row sprayer with individually oriented air outlets. A simple model based on a linear function was used to predict spray deposit using LIDAR measurements and to compare with the deposits measured over the test bench. Results showed differences in the effectiveness of the LIDAR sensor depending on the sprayed droplet size (nozzle type) and air intensity. For conventional mist blower and low air flow rate; the sensor detects a greater number of drift drops obtaining a better correlation (r = 0.91; p < 0.01) than for the case of coarse droplets or high air flow rate. In the case of the multi row sprayer; drift deposition in the test bench was very poor. In general; the use of the LIDAR sensor presents an interesting and easy technique to establish the potential drift of a specific spray situation as an adequate alternative for the evaluation of drift potential. PMID:23282583

  7. Effects of drift angle on model ship flow

    NASA Astrophysics Data System (ADS)

    Longo, J.; Stern, F.

    The effects of drift angle on model ship flow are investigated through towing tank tests for the Series 60 CB=0.6 cargo/container model ship. Resistance, side force, drift moment, sinkage, trim, and heel data are procured for a range of drift angles β and Froude numbers (Fr) and the model free condition. Detailed free-surface and mean velocity and pressure flow maps are procured for high and low Fr=0.316 and 0.16 and β=5° and 10° (free surface) and β=10° (mean velocity and pressure) for the model fixed condition (i.e. fixed with zero sinkage, trim, and heel). Comparison of results at high and low Fr and previous data for β=0° enables identification of important free-surface and drift effects. Geometry, conditions, data, and uncertainty analysis are documented in sufficient detail so as to be useful as a benchmark for computational fluid dynamics (CFD) validation. The resistance increases linearly with β with same slope for all Fr, whereas the increases in the side force, drift moment, sinkage, trim, and heel with β are quadratic. The wave profile is only affected near the bow, i.e. the bow wave amplitude increases/decreases on the windward/leeward sides, whereas the wave elevations are affected throughout the entire wave field. However, the wave envelope angle on both sides is nearly the same as β=0°, i.e. the near-field wave pattern rotates with the hull and remains within a similar wave envelope as β=0°. The wave amplitudes are significantly increased/decreased on the windward/leeward sides. The wake region is also asymmetric with larger wedge angle on the leeward side. The boundary layer and wake are dominated by the hull vortex system consisting of fore body keel, bilge, and wave-breaking vortices and after body bilge and counter-rotating vortices. The occurrence of a wave-breaking vortex for breaking bow waves has not been previously documented in the literature. The trends for the maximum vorticity, circulation, minimum axial velocity, and

  8. Stable discrete representation of relativistically drifting plasmas

    NASA Astrophysics Data System (ADS)

    Kirchen, M.; Lehe, R.; Godfrey, B. B.; Dornmair, I.; Jalas, S.; Peters, K.; Vay, J.-L.; Maier, A. R.

    2016-10-01

    Representing the electrodynamics of relativistically drifting particle ensembles in discrete, co-propagating Galilean coordinates enables the derivation of a Particle-In-Cell algorithm that is intrinsically free of the numerical Cherenkov instability for plasmas flowing at a uniform velocity. Application of the method is shown by modeling plasma accelerators in a Lorentz-transformed optimal frame of reference.

  9. Psychometric Consequences of Subpopulation Item Parameter Drift

    ERIC Educational Resources Information Center

    Huggins-Manley, Anne Corinne

    2017-01-01

    This study defines subpopulation item parameter drift (SIPD) as a change in item parameters over time that is dependent on subpopulations of examinees, and hypothesizes that the presence of SIPD in anchor items is associated with bias and/or lack of invariance in three psychometric outcomes. Results show that SIPD in anchor items is associated…

  10. Unmanned seismometer levels self, corrects drift errors

    NASA Technical Reports Server (NTRS)

    Sutton, G.

    1964-01-01

    Four-component, three-axis, feedback-controlled seismograph incorporates electronic circuitry for leveling and for monitoring the feedback signal required for servo-centering. Viscous damping of the earth-motion signal, compensation of the residual long-term drift, and centering of the seismometers are provided by automatic mechanisms.

  11. Plate Tectonics and Continental Drift: Classroom Ideas.

    ERIC Educational Resources Information Center

    Stout, Prentice K.

    1983-01-01

    Suggests various classroom studies related to plate tectonics and continental drift, including comments on and sources of resource materials useful in teaching the topics. A complete list of magazine articles on the topics from the Sawyer Marine Resource Collection may be obtained by contacting the author. (JN)

  12. Drift waves in helically symmetric stellarators

    SciTech Connect

    Rafiq, T.; Hegna, C.

    2005-11-15

    The local linear stability of electron drift waves and ion temperature gradient modes (ITG) is investigated in a quasihelically symmetric (QHS) stellarator and a conventional asymmetric (Mirror) stellarator. The geometric details of the different equilibria are emphasized. Eigenvalue equations for the models are derived using the ballooning mode formalism and solved numerically using a standard shooting technique in a fully three-dimensional stellarator configuration. While the eigenfunctions have a similar shape in both magnetic geometries, they are slightly more localized along the field line in the QHS case. The most unstable electron drift modes are strongly localized at the symmetry points (where stellarator symmetry is present) and in the regions where normal curvature is unfavorable and magnitude of the local magnetic shear and magnetic field is minimum. The presence of a large positive local magnetic shear in the bad curvature region is found to be destabilizing. Electron drift modes are found to be more affected by the normal curvature than by the geodesic curvature. The threshold of stability of the ITG modes in terms of {eta}{sub i} is found to be 2/3 in this fluid model consistent with the smallest threshold for toroidal geometry with adiabatic electrons. Optimization to favorable drift wave stability has small field line curvature, short connection lengths, the proper combination of geodesic curvature and local magnetic shear, large values of local magnetic shear, and the compression of flux surfaces in the unfavorable curvature region.

  13. Drift correction of electronic tongue responses

    NASA Astrophysics Data System (ADS)

    Holmin, Susanne; Krantz-Rülcker, Christina; Lundström, Ingemar; Winquist, Fredrik

    2001-08-01

    In this article, drift correction algorithms were used in order to remove linear drift in multivariate spaces of two data sets obtained by an electronic tongue based on voltammetry. The electronic tongue consisted of various metal electrodes (Au, Ir, Pt, Rh) combined with pattern recognition tools, such as principal component analysis. The first data set contained different types of liquid, from well defined to more complex solutions. The second data set contained different black and green teas. Component correction (CC) was compared to a simple additive correction. In CC, the drift direction of measured reference solutions in a multivariate space was subtracted from other types of solution. In additive correction, responses from reference samples were subtracted from other samples. CC showed similar or better performance in reducing drift compared to additive correction for the two data sets. The additive correction method was dependent on the fact that the differences in between samples of a reference solution were similar to the changes in between samples of other liquids, which was not the case with CC.

  14. Drift Nets on the High Seas.

    ERIC Educational Resources Information Center

    Clearing, 1990

    1990-01-01

    Information is provided on the use and misuse of drift nets used internationally in the Pacific Ocean. An activity in which students acquire some understanding of the history of fishing and the effects of modern technologies on fish populations is included. (KR)

  15. HIV testing in community pharmacies and retail clinics: A model to expand access to screening for HIV infection

    PubMed Central

    Weidle, Paul J.; Lecher, Shirley; Botts, Linda W.; Jones, LaDawna; Spach, David H.; Alvarez, Jorge; Jones, Rhondette; Thomas, Vasavi

    2015-01-01

    Objective To test the feasibility of offering rapid, point-of-care human immunodeficiency virus (HIV) testing at community pharmacies and retail clinics. Design Pilot program to determine how to implement confidential HIV testing services in community pharmacies and retail clinics. Setting 21 community pharmacies and retail clinics serving urban and rural patients in the United States, from August 2011 to July 2013. Participants 106 community pharmacy and retail clinic staff members. Intervention A model was developed to implement confidential HIV counseling and testing services using community pharmacy and retail clinic staff as certified testing providers, or through collaborations with organizations that provide HIV testing. Training materials were developed and sites selected that serve patients from urban and rural areas to pilot test the model. Each site established a relationship with its local health department for HIV testing policies, developed referral lists for confirmatory HIV testing/care, secured a CLIA Certificate of Waiver, and advertised the service. Staff were trained to perform a rapid point-of-care HIV test on oral fluid, and provide patients with confidential test results and information on HIV. Patients with a preliminary positive result were referred to a physician or health department for confirmatory testing and, if needed, HIV clinical care. Main outcome measures Number of HIV tests completed and amount of time required to conduct testing. Results The 21 participating sites administered 1,540 HIV tests, with 1,087 conducted onsite by staff during regular working hours and 453 conducted at 37 different HIV testing events (e.g., local health fairs). The median amount of time required for pretest counseling/consent, waiting for test results, and posttest counseling was 4, 23, and 3 minutes, respectively. A majority of the sites (17) said they planned to continue HIV testing after the project period ended and would seek assistance or support

  16. Evaluation of spray drift using low speed wind tunnel measurements and dispersion modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this work was to evaluate the EPA’s proposed Test Plan for the validation testing of pesticide spray drift reduction technologies (DRTs) for row and field crops, focusing on the evaluation of ground application systems using the low-speed wind tunnel protocols and processing the dat...

  17. Health insurance for the poor decreases access to HIV testing in antenatal care: evidence of an unintended effect of health insurance reform in Colombia.

    PubMed

    Ettenger, Allison; Bärnighausen, Till; Castro, Arachu

    2014-05-01

    Prevention of mother-to-child transmission of HIV was added to standard antenatal care (ANC) in 2000 for Colombians enrolled in the two national health insurance schemes, the 'subsidized regime' (covering poor citizens) and the 'contributory regime' (covering salaried citizens with incomes above the poverty threshold), which jointly covered 80% of the total Colombian population as of 2007. This article examines integration of HIV testing in ANC through the relationship between ordering an HIV test with the type of health insurance, including lack of health insurance, using data from the nationally representative 2005 Colombia Demographic and Health Survey. Overall, health-care providers ordered an HIV test for only 35% of the women attending ANC. We regressed the order of an HIV test during ANC on health systems characteristics (type of insurance and type of ANC provider), women's characteristics (age, wealth, educational attainment, month of pregnancy at first antenatal visit, HIV knowledge, urban vs. rural residence and sub-region of residence) and children's characteristics (birth order and birth year). Women enrolled in the subsidized regime were significantly less likely to be offered and receive an HIV test in ANC than women without any health insurance (adjusted odds ratio = 0.820, P < 0.001), when controlling for the other independent variables. Wealth, urban residence, birth year of the child and the type of health-care provider seen during the ANC visit were significantly associated with providers ordering an HIV test for a woman (all P < 0.05). Our findings suggest that enrolment in the subsidized regime reduced access to HIV testing in ANC. Additional research is needed to elucidate the mechanisms through which the potential effect of health insurance coverage on HIV testing in ANC occurs and to examine whether enrolment in the subsidized regime has affected access to other essential health services.

  18. Health insurance for the poor decreases access to HIV testing in antenatal care: evidence of an unintended effect of health insurance reform in Colombia

    PubMed Central

    Ettenger, Allison; Bärnighausen, Till; Castro, Arachu

    2014-01-01

    Prevention of mother-to-child transmission of HIV was added to standard antenatal care (ANC) in 2000 for Colombians enrolled in the two national health insurance schemes, the ‘subsidized regime’ (covering poor citizens) and the ‘contributory regime’ (covering salaried citizens with incomes above the poverty threshold), which jointly covered 80% of the total Colombian population as of 2007. This article examines integration of HIV testing in ANC through the relationship between ordering an HIV test with the type of health insurance, including lack of health insurance, using data from the nationally representative 2005 Colombia Demographic and Health Survey. Overall, health-care providers ordered an HIV test for only 35% of the women attending ANC. We regressed the order of an HIV test during ANC on health systems characteristics (type of insurance and type of ANC provider), women’s characteristics (age, wealth, educational attainment, month of pregnancy at first antenatal visit, HIV knowledge, urban vs. rural residence and sub-region of residence) and children’s characteristics (birth order and birth year). Women enrolled in the subsidized regime were significantly less likely to be offered and receive an HIV test in ANC than women without any health insurance (adjusted odds ratio = 0.820, P < 0.001), when controlling for the other independent variables. Wealth, urban residence, birth year of the child and the type of health-care provider seen during the ANC visit were significantly associated with providers ordering an HIV test for a woman (all P < 0.05). Our findings suggest that enrolment in the subsidized regime reduced access to HIV testing in ANC. Additional research is needed to elucidate the mechanisms through which the potential effect of health insurance coverage on HIV testing in ANC occurs and to examine whether enrolment in the subsidized regime has affected access to other essential health services. PMID:23598426

  19. Base metal thermocouples drift rate dependence from thermoelement diameter

    NASA Astrophysics Data System (ADS)

    Pavlasek, P.; Duris, S.; Palencar, R.

    2015-02-01

    Temperature measurements are one of the key factors in many industrial applications that directly affect the quality, effectiveness and safety of manufacturing processes. In many industrial applications these temperature measurements are realized by thermocouples. Accuracy of thermocouples directly affects the quality of the final product of manufacturing and their durability determines the safety margins required. One of the significant effects that affect the precision of the thermocouples is short and long term stability of their voltage output. This stability issue occurs in every type of thermocouples and is caused by multiple factors. In general these factors affect the Seebeck coefficient which is a material constant, which determines the level of generated voltage when exposed to a temperature gradient. Changes of this constant result in the change of the thermocouples voltage output thus indicated temperature which can result in production quality issues, safety and health hazards. These alternations can be caused by physical and chemical changes within the thermocouple lead material. Modification of this material constant can be of temporary nature or permanent. This paper concentrates on the permanent, or irreversible changes of the Seebeck coefficient that occur in commonly used swaged MIMS Type N thermocouples. These permanent changes can be seen as systematic change of the EMF of the thermocouple when it is exposed to a high temperature over a period of time. This change of EMF by time is commonly known as the drift of the thermocouple. This work deals with the time instability of thermocouples EMF at temperatures above 1200 °C. Instability of the output voltage was taken into relation with the lead diameter of the tested thermocouples. This paper concentrates in detail on the change of voltage output of thermocouples of different diameters which were tested at high temperatures for the overall period of more than 210 hours. The gather data from this

  20. Environmental assessment for the Area 5 radioactive waste management site access improvement at the Nevada Test Site

    SciTech Connect

    1997-11-01

    The United States Department of Energy has prepared an Environmental Assessment which analyzes the potential environmental effects of improving access to its AREA 5 RWMS at the NTS. The EA evaluates the potential impacts of constructing an extension of the Cane Springs Road between Mercury Highway and the 5-01 Road. Three alternative actions are also evaluated: (1) construction of a new road along the existing alignment of the Powerline Road between Mercury Highway and the 5-01 Road, (2) upgrading the existing 5-01 Road, and (3) taking no action. The purpose and need for improving access to the RWMS are addressed in Section 1.0 of the EA. A detailed description of the proposed action and alternatives is in Section 2.0. Section 3.0 describes the affected environment and Section 4.0 the environmental effects of the proposed action and alternatives. Health and transportation effects, accident scenarios, cumulative effects, and other relevant information are found in Sections 5.0 through 12.0 of the EA. DOE determined that the alternative action of upgrading the existing 5-01 Road would best meet the needs of the agency.

  1. The Effects of Clock Drift on the Mars Exploration Rovers

    NASA Technical Reports Server (NTRS)

    Ali, Khaled S.; Vanelli, C. Anthony

    2012-01-01

    All clocks drift by some amount, and the mission clock on the Mars Exploration Rovers (MER) is no exception. The mission clock on both MER rovers drifted significantly since the rovers were launched, and it is still drifting on the Opportunity rover. The drift rate is temperature dependent. Clock drift causes problems for onboard behaviors and spacecraft operations, such as attitude estimation, driving, operation of the robotic arm, pointing for imaging, power analysis, and telecom analysis. The MER operations team has techniques to deal with some of these problems. There are a few techniques for reducing and eliminating the clock drift, but each has drawbacks. This paper presents an explanation of what is meant by clock drift on the rovers, its relationship to temperature, how we measure it, what problems it causes, how we deal with those problems, and techniques for reducing the drift.

  2. Drift instabilities in current sheets with guide field

    SciTech Connect

    Yoon, P. H.; Lui, A. T. Y.

    2008-07-15

    Drift instabilities in current sheets with or without the guide field are investigated with a newly developed improved electrostatic dispersion relation. Traditional (local) theories of lower-hybrid drift instability typically assumes small electron drift speed, and expand the electron distribution function in Taylor series. This approximate treatment is removed in this paper. The resulting formalism is uniformly valid for an arbitrary magnitude of relative ion and electron drift speeds, and is valid for an arbitrary strength of the guide field.

  3. Voluntary Counseling and Testing Services: Breaking Resistance to Access and Utilization among the Youths in Rakai District of Uganda

    ERIC Educational Resources Information Center

    Sebudde, Stephen; Nangendo, Florence

    2009-01-01

    Voluntary counseling and testing is important in controlling the spread of HIV, especially among adolescents. The aim is to describe the perceptions of adolescents of the best options to providing voluntary counseling and testing services to them in Rakai District Uganda. A cross-sectional descriptive study was carried out among male and female…

  4. The Legacy Continues: "The Test" and Denying Access to a Challenging Mathematics Education for Historically Marginalized Students

    ERIC Educational Resources Information Center

    Kitchen, Richard; Ridder, Sarah Anderson; Bolz, Joseph

    2016-01-01

    Research is needed to understand the impact of high-stakes testing on teachers' practices and consequently on their students, particularly at schools that serve large numbers of low-income students and students of color. In this research study, we examined how a state's annual high-stakes test and administrative mandates influenced the assessment…

  5. Arteriovenous Access

    PubMed Central

    MacRae, Jennifer M.; Dipchand, Christine; Oliver, Matthew; Moist, Louise; Yilmaz, Serdar; Lok, Charmaine; Leung, Kelvin; Clark, Edward; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Luscombe, Rick; Miller, Lisa M.

    2016-01-01

    Complications of vascular access lead to morbidity and may reduce quality of life. In this module, we review both infectious and noninfectious arteriovenous access complications including neuropathy, aneurysm, and high-output access. For the challenging patients who have developed many complications and are now nearing their last vascular access, we highlight some potentially novel approaches. PMID:28270919

  6. Longevity of Emplacement Drift Ground Support Materials

    SciTech Connect

    Tang, David H.

    2001-05-30

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M&O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M&O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4) Evaluate factors

  7. Measurement of spatial distribution of total and accessible porosity in sedimentary rocks using isotopic radiation transmission: device design and testing.

    PubMed

    Subudhi, Ranjit K; Hussein, Esam M A; Al, Tom A

    2010-03-01

    An isotopic radiation transmission technique for quantifying the spatial distribution of porosity in sedimentary rocks is presented. A device was designed and constructed to examine rock samples of volumes sufficiently large for studying solute migration in rocks, so that a one-millimeter spatial resolution is attained with measurement acquisition time of one point per second. The paper demonstrates how the device was optimized for these specifications, while abiding by the restrictions implicit in the utilization of the exponential law of radiation attenuation to quantify physical parameters. Total porosity was obtained from measurements of radiation attenuation in dry samples, while solute-accessible porosity was determined from measurements with samples saturated with either KNO(3) or KI solutions. Results are presented for three different rock types to demonstrate the capabilities and limitations of the technique.

  8. DRIFTSIM, A Computer Program for Estimating Spray Drift Distances

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the severe problems with spraying pesticides is the spray drift. Drift is a problem if chemicals are sprayed too close to residential areas, livestock facilities, bodies of water, or sensitive crops. Complaints regarding spray drift are routinely brought to state departments of agriculture,...

  9. Age of marginal Wisconsin drift at corry, northwestern Pennsylvania

    USGS Publications Warehouse

    Droste, J.B.; Rubin, M.; White, G.W.

    1959-01-01

    Marl began to accumulate about 14,000 years ago, as determined by radiocarbon dating, in a pond in a kettle hole in Kent drift at Corry, Pa., 9 miles inside the Wisconsin drift margin. This radiocarbon age represents the minimum time since the disappearance of the ice from Corry and confirms an assignment of Cary age to the drift.

  10. Accessing HIV testing and treatment among men who have sex with men in China: a qualitative study.

    PubMed

    Wei, Chongyi; Yan, Hongjing; Yang, Chuankun; Raymond, H Fisher; Li, Jianjun; Yang, Haitao; Zhao, Jinkou; Huan, Xiping; Stall, Ron

    2014-01-01

    Barriers to HIV testing and HIV care and treatment pose significant challenges to HIV prevention among men who have sex with men (MSM) in China. We carried out a qualitative study to identify barriers and facilitators to HIV testing and treatment among Chinese MSM. In 2012, seven focus group (FG) discussions were conducted with 49 MSM participants in Nanjing, China. Purposive sampling was used to recruit a diverse group of MSM participants. Semi-structured interviews were conducted to collect FG data. Major barriers to testing included gay- and HIV-related stigma and discrimination, relationship type and partner characteristics, low perception of risk or threat, HIV is incurable or equals death, concerns of confidentiality, unaware that testing is offered for free, and name-based testing. Key facilitators of testing included engaging in high-risk sex, sense of responsibility for partner, collectivism, testing as a part of standard/routine medical care, MSM-friendly medical personnel, increased acceptance of gay/bisexual men by the general public, legal recognition and protection of homosexuals, and home self-testing. Barriers to treatment included negative coping, nondisclosure to families, misconceptions of domestically produced antiretroviral drugs (ARVs) and the benefits of treatment, and costs associated with long-term treatment. Facilitators of treatment included sense of hopefulness that a cure would be found, the cultural value of longevity, peer social support and professional psychological counseling, affordable and specialized treatment and care, and reduced HIV-related stigma and discrimination. Finally, for both testing and treatment, more educational and promotional activities within MSM communities and among the general public are needed.

  11. Accessing HIV Testing and Treatment among Men Who Have Sex with Men in China: A Qualitative Study

    PubMed Central

    Wei, Chongyi; Yan, Hongjing; Yang, Chuankun; Raymond, H. Fisher; Li, Jianjun; Yang, Haitao; Zhao, Jinkou; Huan, Xiping; Stall, Ron

    2013-01-01

    Barriers to HIV testing and HIV care and treatment pose significant challenges to HIV prevention among men who have sex with men (MSM) in China. We carried out a qualitative study to identify barriers and facilitators to HIV testing and treatment among Chinese MSM. In 2012, 7 focus group discussions were conducted with 49 MSM participants in Nanjing, China. Purposive sampling was used to recruit a diverse group of MSM participants. Semi-structured interviews were conducted to collect FG data. Major barriers to testing included gay- and HIV-related stigma and discrimination, relationship type and partner characteristics, low perception of risk or threat, HIV is incurable or equals death, concerns of confidentiality, unaware that testing is offered for free, and name-based testing. Key facilitators of testing included engaging in high-risk sex, sense of responsibility for partner, collectivism, testing as a part of standard/routine medical care, MSM-friendly medical personnel, increased acceptance of gay/bisexual men by the general public, legal recognition and protection of homosexuals, and home self-testing. Barriers to treatment included negative coping, non-disclosure to families, misconceptions of domestically produced antiretroviral drugs and the benefits of treatment, and costs associated with long-term treatment. Facilitators of treatment included sense of hopefulness that a cure would be found, the cultural value of longevity, peer social support and professional psychological counseling, affordable and specialized treatment and care, and reduced HIV-related stigma and discrimination. Finally, for both testing and treatment, more educational and promotional activities within MSM communities and among the general public are needed. PMID:23909807

  12. Geographical information system and access to HIV testing, treatment and prevention of mother-to-child transmission in conflict affected Northern Uganda

    PubMed Central

    Chamla, Dick D; Olu, Olushayo; Wanyana, Jennifer; Natseri, Nasan; Mukooyo, Eddie; Okware, Sam; Alisalad, Abdikamal; George, Melville

    2007-01-01

    Objectives Using Geographical Information System (GIS) as a tool to determine access to and gaps in providing HIV counselling and testing (VCT), treatment (ART) and mother-to-child transmission (PMTCT) services in conflict affected northern Uganda. Methods Cross-sectional data on availability and utilization, and geo-coordinates of health facilities providing VCT, PMTCT, and ART were collected in order to determine access. ArcView software produced maps showing locations of facilities and Internally Displaced Population(IDP) camps. Findings There were 167 health facilities located inside and outside 132 IDP camps with VCT, PMTCT and ART services provided in 32 (19.2%), 15 (9%) and 10 (6%) facilities respectively. There was uneven availability and utilization of services and resources among districts, camps and health facilities. Inadequate staff and stock-out of essential commodities were found in lower health facility levels. Provision of VCT was 100% of the HSSP II target at health centres IV and hospitals but 28% at HC III. For PMTCT and ART, only 42.9% and 20% of the respective targets were reached at the health centres IV. Conclusion Access to VCT, PMTCT and ART services was geographically limited due to inadequacy and heterogeneous dispersion of these services among districts and camps. GIS mapping can be effective in identifying service delivery gaps and presenting complex data into simplistic results hence can be recommended in need assessments in conflict settings. PMID:18053189

  13. Preliminary geochemical and physical testing of materials for plugging of man-made accesses to a repository in basalt

    SciTech Connect

    Taylor, C.L.; Anttonen, G.J.; O'Rourke, J.E.; Allirot, D.

    1980-04-01

    The available data on environmental conditions (both natural and man-made) at the Hanford Site are sufficient for preconceptual plug system design. Results of the geochemical testing program indicate that preferred candidate plug materials are chemically nonreactive during laboratory tests that simulated some of the expected environmental conditions. Agitated, crushed-basalt samples and mixtures containing basalt were found to be self-cementing under the hydrothermal conditions. Materials considered most suitable for consideration in future test programs and preconceptual plug design are mixtures of natural materials (basalt, clay, glaciofluvial sand, gravel, and zeolite) and processed natural materials (portland cement Type V and grouts plus additives).

  14. Protecting Pharmaceutical Patents and Test Data: How the Trans-Pacific Partnership Agreement Could Affect Access to Medicines in the US and Abroad.

    PubMed

    Luo, Jing; Kesselheim, Aaron S

    2016-07-01

    The Trans-Pacific Partnership (TPP) Agreement is a proposed free trade agreement between the US and 11 other countries in Asia and South America covering many consumer goods, including prescription medicines. This review describes how the TPP could affect international laws governing intellectual property rights for prescription drugs, focusing on patents and exclusivity protections for test data, including their effect on reimbursement decisions by national health care authorities responsible for health priority setting. We conclude that the TPP could affect low-income patients' access to medicines in signatory countries.

  15. Developing Astrometric Drift Scans for the Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Carey, Sean J.; Ingalls, J.; Stauffer, J. R.; Grillmair, C. J.

    2014-01-01

    We are currently developing and optimizing a new observing mode using the IRAC instrument on-board the Spitzer Space Telescope. The new method which uses a constant rate drift scan while the instrument collects data is based on the successful HST drift scan method for producing high astrometric precision (20 micro-arcsecond) parallaxes to improve the cosmological distance scale. The HST experience indicates that a factor of 10 improvement in astrometric precision is possible. Currently Spitzer astrometric precision is of order 20-40 milli-arcseconds per epoch. Increasing the precision by even a factor of three greatly facilitates studies of nearby brown dwarfs and increases our ability to measure parallaxes to these intrinsically faint and cool sources out to ~30 parsecs. Initial tests of the method with observations of NGC 2516 at 3.6 and 4.5 microns have shown that useful data are taken in drift scan mode and the scans are in the specified direction and rate. We have developed a tool to measure source centroids in the stacks of images taken while scanning. The tool groups the centroids into tracklets which can then be simultaneously fit to remove telescope jitter and instrumental distortion. We present our latest results in the analysis of this mode and the prospects for the scientific exploitation of this method. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  16. A Study of a Mini-Drift GEM Tracking Detector

    DOE PAGES

    Azmoun, B.; DiRuzza, B.; Franz, A.; ...

    2016-06-22

    In this paper, a GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a 1.6 cm drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing themore » chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 μm pitch XY strips and the other consisted of 2 × 10 mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Finally, applications for large angle tracking detectors at RHIC and EIC are also discussed.« less

  17. A Study of a Mini-Drift GEM Tracking Detector

    SciTech Connect

    Azmoun, B.; DiRuzza, B.; Franz, A.; Kiselev, A.; Pak, R.; Phipps, M.; Purschke, M. L.; Woody, C.

    2016-06-22

    In this paper, a GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a 1.6 cm drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 μm pitch XY strips and the other consisted of 2 × 10 mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Finally, applications for large angle tracking detectors at RHIC and EIC are also discussed.

  18. Bottle appeal drifts across the Pacific

    NASA Astrophysics Data System (ADS)

    Ebbesmeyer, Curtis; Ingraham, W. James, Jr.; McKinnon, Richard; Okubo, Akira; Wang, Dong-Ping; Strickland, Richard; Willing, Peter

    Pacific drift currents were used by a group of oceanographers to estimate the path of a drift bottle that was found on a beach of Barkley Sound in Vancouver Island by Richard Strickland on June 10, 1990. The Chinese rice wine bottle, which remained unopened until December 18, 1991, contained six leaflets, one appealing for the release of China's well-known dissident, Wei Jingsheng. The bottle was one of thousands set adrift as part of a propaganda effort from the islands of Quemoy and Matsu off mainland China shortly after Wei was sentenced in 1979 to 15 years in prison (see Figure 1 for locations). Wei was in poor health and still in prison when the bottle made its way across the Pacific Ocean.

  19. Electromagnetic nonlinear gyrokinetics with polarization drift

    SciTech Connect

    Duthoit, F.-X.; Hahm, T. S.; Wang, Lu

    2014-08-15

    A set of new nonlinear electromagnetic gyrokinetic Vlasov equation with polarization drift and gyrokinetic Maxwell equations is systematically derived by using the Lie-transform perturbation method in toroidal geometry. For the first time, we recover the drift-kinetic expression for parallel acceleration [R. M. Kulsrud, in Basic Plasma Physics, edited by A. A. Galeev and R. N. Sudan (North-Holland, Amsterdam, 1983)] from the nonlinear gyrokinetic equations, thereby bridging a gap between the two formulations. This formalism should be useful in addressing nonlinear ion Compton scattering of intermediate-mode-number toroidal Alfvén eigenmodes for which the polarization current nonlinearity [T. S. Hahm and L. Chen, Phys. Rev. Lett. 74, 266 (1995)] and the usual finite Larmor radius effects should compete.

  20. Longevity of emplacement drift ground support materials

    SciTech Connect

    Tang, David

    2000-04-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. The Development Plan (DP) for this analysis is given in Longevity of Emplacement Drift Ground Support Materials (CRWMS M and O 1999a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999b), and in environmental conditions, and to provide updated information on candidate ground support materials.

  1. Electromagnetic nonlinear gyrokinetics with polarization drift

    NASA Astrophysics Data System (ADS)

    Duthoit, F.-X.; Hahm, T. S.; Wang, Lu

    2014-08-01

    A set of new nonlinear electromagnetic gyrokinetic Vlasov equation with polarization drift and gyrokinetic Maxwell equations is systematically derived by using the Lie-transform perturbation method in toroidal geometry. For the first time, we recover the drift-kinetic expression for parallel acceleration [R. M. Kulsrud, in Basic Plasma Physics, edited by A. A. Galeev and R. N. Sudan (North-Holland, Amsterdam, 1983)] from the nonlinear gyrokinetic equations, thereby bridging a gap between the two formulations. This formalism should be useful in addressing nonlinear ion Compton scattering of intermediate-mode-number toroidal Alfvén eigenmodes for which the polarization current nonlinearity [T. S. Hahm and L. Chen, Phys. Rev. Lett. 74, 266 (1995)] and the usual finite Larmor radius effects should compete.

  2. Rough differential equations with unbounded drift term

    NASA Astrophysics Data System (ADS)

    Riedel, S.; Scheutzow, M.

    2017-01-01

    We study controlled differential equations driven by a rough path (in the sense of T. Lyons) with an additional, possibly unbounded drift term. We show that the equation induces a solution flow if the drift grows at most linearly. Furthermore, we show that the semiflow exists assuming only appropriate one-sided growth conditions. We provide bounds for both the flow and the semiflow. Applied to stochastic analysis, our results imply strong completeness and the existence of a stochastic (semi)flow for a large class of stochastic differential equations. If the driving process is Gaussian, we can further deduce (essentially) sharp tail estimates for the (semi)flow and a Freidlin-Wentzell-type large deviation result.

  3. Gas sensor with attenuated drift characteristic

    DOEpatents

    Chen, Ing-Shin [Danbury, CT; Chen, Philip S. H. [Bethel, CT; Neuner, Jeffrey W [Bethel, CT; Welch, James [Fairfield, CT; Hendrix, Bryan [Danbury, CT; Dimeo, Jr., Frank [Danbury, CT

    2008-05-13

    A sensor with an attenuated drift characteristic, including a layer structure in which a sensing layer has a layer of diffusional barrier material on at least one of its faces. The sensor may for example be constituted as a hydrogen gas sensor including a palladium/yttrium layer structure formed on a micro-hotplate base, with a chromium barrier layer between the yttrium layer and the micro-hotplate, and with a tantalum barrier layer between the yttrium layer and an overlying palladium protective layer. The gas sensor is useful for detection of a target gas in environments susceptible to generation or incursion of such gas, and achieves substantial (e.g., >90%) reduction of signal drift from the gas sensor in extended operation, relative to a corresponding gas sensor lacking the diffusional barrier structure of the invention

  4. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, James H.

    1996-01-01

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

  5. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, J.H.

    1996-11-26

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.

  6. Passive appendages generate drift through symmetry breaking

    PubMed Central

    Lācis, U.; Brosse, N.; Ingremeau, F.; Mazzino, A.; Lundell, F.; Kellay, H.; Bagheri, S.

    2014-01-01

    Plants and animals use plumes, barbs, tails, feathers, hairs and fins to aid locomotion. Many of these appendages are not actively controlled, instead they have to interact passively with the surrounding fluid to generate motion. Here, we use theory, experiments and numerical simulations to show that an object with a protrusion in a separated flow drifts sideways by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in a fluid flow is unstable and how it stabilizes either to the left or right of the incoming flow direction. It is plausible that organisms with appendages in a separated flow use this newly discovered mechanism for locomotion; examples include the drift of plumed seeds without wind and the passive reorientation of motile animals. PMID:25354545

  7. Qualitative Assessment of Barriers and Facilitators of Access to HIV Testing Among Men Who Have Sex with Men in China.

    PubMed

    Liu, Yu; Sun, Xiaoyun; Qian, Han-Zhu; Yin, Lu; Yan, Zheng; Wang, Lijuan; Jiang, Shulin; Lu, Hongyan; Ruan, Yuhua; Shao, Yiming; Vermund, Sten H; Amico, K Rivet

    2015-09-01

    Diagnosis of HIV is the entry point into the continuum of HIV care; a well-recognized necessary condition for the ultimate prevention of onward transmission. In China, HIV testing rates among men who have sex with men (MSM) are low compared to other high risk subgroups, yet experiences with HIV testing among MSM in China are not well understood. To address this gap and prepare for intervention development to promote HIV testing and rapid linkage to treatment, six focus groups (FGs) were conducted with MSM in Beijing (40 HIV-positive MSM participated in one of four FGs and 20 HIV-negative or status unknown MSM participated in one of two FGs). Major themes reported as challenges to HIV testing included stigma and discrimination related to HIV and homosexuality, limited HIV knowledge, inconvenient clinic times, not knowing where to get a free test, fear of positive diagnosis or nosocomial infection, perceived low service quality, and concerns/doubts about HIV services. Key facilitators included compensation, peer support, professionalism, comfortable testing locations, rapid testing, referral and support after diagnosis, heightened sense of risk through engagement in high-risk behaviors, sense of responsibility to protect self, family and partner support, and publicity via social media. Themes and recommendations were generally consistent across HIV-positive and negative/status unknown groups, although examples of enacted stigma were more prevalent in the HIV-positive groups. Findings from our study provide policy suggestions for how to bolster current HIV prevention intervention efforts to enhance 'test-and-treat' strategies for Chinese MSM.

  8. Qualitative Assessment of Barriers and Facilitators of Access to HIV Testing Among Men Who Have Sex with Men in China

    PubMed Central

    Liu, Yu; Sun, Xiaoyun; Yin, Lu; Yan, Zheng; Wang, Lijuan; Jiang, Shulin; Lu, Hongyan; Ruan, Yuhua; Shao, Yiming; Vermund, Sten H.

    2015-01-01

    Abstract Diagnosis of HIV is the entry point into the continuum of HIV care; a well-recognized necessary condition for the ultimate prevention of onward transmission. In China, HIV testing rates among men who have sex with men (MSM) are low compared to other high risk subgroups, yet experiences with HIV testing among MSM in China are not well understood. To address this gap and prepare for intervention development to promote HIV testing and rapid linkage to treatment, six focus groups (FGs) were conducted with MSM in Beijing (40 HIV-positive MSM participated in one of four FGs and 20 HIV-negative or status unknown MSM participated in one of two FGs). Major themes reported as challenges to HIV testing included stigma and discrimination related to HIV and homosexuality, limited HIV knowledge, inconvenient clinic times, not knowing where to get a free test, fear of positive diagnosis or nosocomial infection, perceived low service quality, and concerns/doubts about HIV services. Key facilitators included compensation, peer support, professionalism, comfortable testing locations, rapid testing, referral and support after diagnosis, heightened sense of risk through engagement in high-risk behaviors, sense of responsibility to protect self, family and partner support, and publicity via social media. Themes and recommendations were generally consistent across HIV-positive and negative/status unknown groups, although examples of enacted stigma were more prevalent in the HIV-positive groups. Findings from our study provide policy suggestions for how to bolster current HIV prevention intervention efforts to enhance ‘test-and-treat’ strategies for Chinese MSM. PMID:26186029

  9. Oceanic sediment volumes and continental drift.

    PubMed

    Gilluly, J

    1969-11-21

    The volume of sediment off the Atlantic Coast of the United States is at least six times as great as that off the Pacific Coast. This disparity is readily accounted for if the continent is drifting westward and has overrun large volumes of sediment on a former Benioff zone. Such an overrunning is also consonant with many features of the geology of the western United States.

  10. Inertial Orientation Trackers with Drift Compensation

    NASA Technical Reports Server (NTRS)

    Foxlin, Eric M.

    2008-01-01

    A class of inertial-sensor systems with drift compensation has been invented for use in measuring the orientations of human heads (and perhaps other, similarly sized objects). These systems can be designed to overcome some of the limitations of prior orientation-measuring systems that are based, variously, on magnetic, optical, mechanical-linkage, and acoustical principles. The orientation signals generated by the systems of this invention could be used for diverse purposes, including controlling head-orientation-dependent virtual reality visual displays or enabling persons whose limbs are paralyzed to control machinery by means of head motions. The inventive concept admits to variations too numerous to describe here, making it necessary to limit this description to a typical system, the selected aspects of which are illustrated in the figure. A set of sensors is mounted on a bracket on a band or a cap that gently but firmly grips the wearer s head to be tracked. Among the sensors are three drift-sensitive rotationrate sensors (e.g., integrated-circuit angular- rate-measuring gyroscopes), which put out DC voltages nominally proportional to the rates of rotation about their sensory axes. These sensors are mounted in mutually orthogonal orientations for measuring rates of rotation about the roll, pitch, and yaw axes of the wearer s head. The outputs of these rate sensors are conditioned and digitized, and the resulting data are fed to an integrator module implemented in software in a digital computer. In the integrator module, the angular-rate signals are jointly integrated by any of several established methods to obtain a set of angles that represent approximately the orientation of the head in an external, inertial coordinate system. Because some drift is always present as a component of an angular position computed by integrating the outputs of angular-rate sensors, the orientation signal is processed further in a drift-compensator software module.

  11. Social diffusion and global drift on networks

    NASA Astrophysics Data System (ADS)

    Sayama, Hiroki; Sinatra, Roberta

    2015-03-01

    We study a mathematical model of social diffusion on a symmetric weighted network where individual nodes' states gradually assimilate to local social norms made by their neighbors' average states. Unlike physical diffusion, this process is not state conservational and thus the global state of the network (i.e., sum of node states) will drift. The asymptotic average node state will be the average of initial node states weighted by their strengths. Here we show that, while the global state is not conserved in this process, the inner product of strength and state vectors is conserved instead, and perfect positive correlation between node states and local averages of their self-neighbor strength ratios always results in upward (or at least neutral) global drift. We also show that the strength assortativity negatively affects the speed of homogenization. Based on these findings, we propose an adaptive link weight adjustment method to achieve the highest upward global drift by increasing the strength-state correlation. The effectiveness of the method was confirmed through numerical simulations and implications for real-world social applications are discussed.

  12. Wind tunnel observations of drifting snow

    NASA Astrophysics Data System (ADS)

    Paterna, Enrico; Crivelli, Philip; Lehning, Michael

    2016-04-01

    Drifting snow has a significant impact on snow redistribution in mountains, prairies as well as on glaciers, ice shelves, and sea ice. In all these environments, the local mass balance is highly influenced by drifting snow. Understanding the dynamic of snow saltation is crucial to the accurate description of the process. We applied digital shadowgraphy in a cold wind tunnel to measure drifting snow over natural snow covers. The acquisition and evaluation of time-resolved shadowgraphy images allowed us to resolve a large part of the saltation layer. The technique has been successfully compared to the measurements obtained from a Snow Particle Counter, considered the most robust technique for snow mass-flux measurements so far. The streamwise snow transport is dominated by large-scale events. The vertical snow transport has a more equal distribution of energy across the scales, similarly to what is observed for the flow turbulence velocities. It is hypothesized that the vertical snow transport is a quantity that reflects the local entrainment of the snow crystals into the saltation layer while the streamwise snow transport results from the streamwise development of the trajectories of the snow particles once entrained, and therefore is rather a non-local quantity.

  13. Drift mode growth rates and associated transport

    SciTech Connect

    Redd, A.J.; Kritz, A.H.; Bateman, G.; Rewoldt, G.; Tang, W.M.

    1999-04-01

    Drift mode linear growth rates and quasilinear transport are investigated using the FULL kinetic stability code [Rewoldt {ital et al.}, Phys. Plasmas {bold 5}, 1815 (1998)] and a version of the Weiland transport model [Strand {ital et al.}, Nucl. Fusion {bold 38}, 545 (1998)]. It is shown that the drift mode growth rates (as well as the marginal stability temperature gradient) obtained using the FULL code are dependent on the accuracy of the equilibrium employed. In particular, when an approximate equilibrium model is utilized by the FULL code, the results can differ significantly from those obtained using a more accurate numerical equilibrium. Also investigated are the effects of including full electron physics. It is shown, using both the FULL code and the Weiland model, that the nonadiabatic (e.g., trapped) electron response produces a significant increase in the linear growth rate of the ion-temperature-gradient (ITG) driven branch of the drift instability. Other consequences of the nonadiabatic electron response include a reduction in the marginal temperature gradient for the onset of the ITG mode and an additional contribution to transport due to the excitation of the Trapped Electron Mode (TEM). Physical explanations are given for the sensitivity of the mode growth rates to the equilibrium and the nonadiabatic electron response. Finally, linear growth rates for the ITG mode computed using the FULL code are compared with growth rates obtained using the Weiland model. {copyright} {ital 1999 American Institute of Physics.}

  14. Causal Drift, Robust Signaling, and Complex Disease

    PubMed Central

    Wagner, Andreas

    2015-01-01

    The phenotype of many regulatory circuits in which mutations can cause complex, polygenic diseases is to some extent robust to DNA mutations that affect circuit components. Here I demonstrate how such mutational robustness can prevent the discovery of genetic disease determinants. To make my case, I use a mathematical model of the insulin signaling pathway implicated in type 2 diabetes, whose signaling output is governed by 15 genetically determined parameters. Using multiple complementary measures of a parameter’s importance for this phenotype, I show that any one disease determinant that is crucial in one genetic background will be virtually irrelevant in other backgrounds. In an evolving population that drifts through the parameter space of this or other robust circuits through DNA mutations, the genetic changes that can cause disease will vary randomly over time. I call this phenomenon causal drift. It means that mutations causing disease in one (human or non-human) population may have no effect in another population, and vice versa. Causal drift casts doubt on our ability to infer the molecular mechanisms of complex diseases from non-human model organisms. PMID:25774510

  15. Longevity of Emplacement Drift Ground Support Materials

    SciTech Connect

    D. Tang

    2000-01-07

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M&O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used.

  16. Sunrise enhancement of equatorial vertical plasma drift

    NASA Astrophysics Data System (ADS)

    Liu, Libo; Zhang, Ruilong; Le, Huijun

    2016-04-01

    Sunrise enhancement in vertical plasma drift over equatorial regions is not discernible in the statistical picture compared with the significant enhancement during dusk hours. In this report, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag. Moreover, we will report the effects of the sunrise enhancement of vertical plasma drift on the equatorial ionosphere as indicated from the observations and model simulations. We thanks National Central University of Taiwan providing the ROCSAT-1 data. The Ap and F107 indices are obtained from the National Geophysical Data Center (http://spidr.ngdc.noaa.gov/spidr/). This research is supported by National Natural Science Foundation of China (41231065), the Chinese Academy of Sciences project (KZZD-EW-01-3), National Key Basic Research Program of China (2012CB825604) and National Natural Science Foundation of China (41321003).

  17. Impact of Gene Patents and Licensing Practices on Access to Genetic Testing for Alzheimer’s Disease

    PubMed Central

    Skeehan, Katie; Heaney, Christopher; Cook-Deegan, Robert

    2010-01-01

    Genetic testing for Alzheimer’s disease (AD) includes genotyping for apolipoprotein E, for late-onset AD, and three rare autosomal dominant, early-onset forms of AD associated with different genes (APP, PSEN1 and PSEN2). According to researchers, patents have not impeded research in the field, nor were patents an important consideration in the quest for the genetic risk factors. Athena Diagnostics holds exclusive licenses from Duke University for three “method” patents covering APOE genetic testing. Athena offers tests for APOE and genes associated with early onset, autosomal dominant AD. One of those presenilin genes is patented and exclusively licensed to Athena; the other presenilin gene was patented but the patent was allowed to lapse; and one (APP) is patented only as a research tool and patent claims do not cover diagnostic use. Direct-to-consumer testing is available for some AD-related genes, apparently without a license. Athena Diagnostics consolidated its position in the market for AD genetic testing by collecting exclusive rights to patents arising from university research. Duke University also used its licenses to Athena to enforce adherence to clinical guidelines, including elimination of the service from Smart Genetics, which was offering direct-to-consumer risk assessment based on APOE genotyping. PMID:20393312

  18. Concept of a solid-state drift chamber

    SciTech Connect

    Gatti, E.; Rehak, P.

    1983-03-01

    The operation of a solid state drift chamber is described, and its use in a high rate, high multiplicity environment is discussed. The Solid State Drift Chamber (SSDCH) is a thin wafer of a high purity n-type silicon (few cm/sup 2/ x a few hundreds ..mu..m thick) with a single small-area, small-capacitance anode readout. The drift voltage is supplied to an array of drift electrodes on both sides of the wafer to produce a uniform drift field parallel to the surface of the wafer and to ensure the complete depletion of the wafer. (WHK)

  19. Gas analyzer's drift leads to systematic error in maximal oxygen uptake and maximal respiratory exchange ratio determination

    PubMed Central

    Garcia-Tabar, Ibai; Eclache, Jean P.; Aramendi, José F.; Gorostiaga, Esteban M.

    2015-01-01

    The aim was to examine the drift in the measurements of fractional concentration of oxygen (FO2) and carbon dioxide (FCO2) of a Nafion-using metabolic cart during incremental maximal exercise in 18 young and 12 elderly males, and to propose a way in which the drift can be corrected. The drift was verified by comparing the pre-test calibration values with the immediate post-test verification values of the calibration gases. The system demonstrated an average downscale drift (P < 0.001) in FO2 and FCO2 of −0.18% and −0.05%, respectively. Compared with measured values, corrected average maximal oxygen uptakevalues were 5–6% lower (P < 0.001) whereas corrected maximal respiratory exchange ratio values were 8–9% higher (P < 0.001). The drift was not due to an electronic instability in the analyzers because it was reverted after 20 min of recovery from the end of the exercise. The drift may be related to an incomplete removal of water vapor from the expired gas during transit through the Nafion conducting tube. These data demonstrate the importance of checking FO2 and FCO2 values by regular pre-test calibrations and post-test verifications, and also the importance of correcting a possible shift immediately after exercise. PMID:26578980

  20. Gas analyzer's drift leads to systematic error in maximal oxygen uptake and maximal respiratory exchange ratio determination.

    PubMed

    Garcia-Tabar, Ibai; Eclache, Jean P; Aramendi, José F; Gorostiaga, Esteban M

    2015-01-01

    The aim was to examine the drift in the measurements of fractional concentration of oxygen (FO2) and carbon dioxide (FCO2) of a Nafion-using metabolic cart during incremental maximal exercise in 18 young and 12 elderly males, and to propose a way in which the drift can be corrected. The drift was verified by comparing the pre-test calibration values with the immediate post-test verification values of the calibration gases. The system demonstrated an average downscale drift (P < 0.001) in FO2 and FCO2 of -0.18% and -0.05%, respectively. Compared with measured values, corrected average maximal oxygen uptakevalues were 5-6% lower (P < 0.001) whereas corrected maximal respiratory exchange ratio values were 8-9% higher (P < 0.001). The drift was not due to an electronic instability in the analyzers because it was reverted after 20 min of recovery from the end of the exercise. The drift may be related to an incomplete removal of water vapor from the expired gas during transit through the Nafion conducting tube. These data demonstrate the importance of checking FO2 and FCO2 values by regular pre-test calibrations and post-test verifications, and also the importance of correcting a possible shift immediately after exercise.

  1. In-Drift Precipitates/Salts Analysis

    SciTech Connect

    P. Mariner

    2001-01-10

    As directed by a written development plan (CRWMS M&O 1999a), an analysis of the effects of salts and precipitates on the repository chemical environment is to be developed and documented in an Analyses/Model Report (AMR). The purpose of this analysis is to assist Performance Assessment Operations (PAO) and the Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). The purpose of this ICN is to qualify and document qualification of the AMR's technical products. The scope of this document is to develop a model of the processes that govern salt precipitation and dissolution and resulting water composition in the Engineered Barrier System (EBS). This model is developed to serve as a basis for the in-drift geochemical modeling work performed by PAO and is to be used in subsequent PAO analyses including the EBS physical and chemical model abstraction effort. However, the concepts may also apply to some near and far field geochemical processes and can have conceptual application within the unsaturated zone and saturated zone transport modeling efforts. The intended use of the model developed in this report is to estimate, within an appropriate level of confidence, the pH, chloride concentration, and ionic strength of water on the drip shield or other location within the drift during the post-closure period. These estimates are based on evaporative processes that are subject to a broad range of potential environmental conditions and are independent of the presence or absence of backfill. An additional intended use is to estimate the environmental conditions required for complete vaporization of water. The presence and composition of liquid water in

  2. Reconnection and Spire Drift in Coronal Jets

    NASA Astrophysics Data System (ADS)

    Moore, Ronald; Sterling, Alphonse; Falconer, David

    2015-04-01

    It is observed that there are two morphologically-different kinds of X-ray/EUV jets in coronal holes: standard jets and blowout jets. In both kinds: (1) in the base of the jet there is closed magnetic field that has one foot in flux of polarity opposite that of the ambient open field of the coronal hole, and (2) in coronal X-ray/EUV images of the jet there is typically a bright nodule at the edge of the base. In the conventional scenario for jets of either kind, the bright nodule is a compact flare arcade, the downward product of interchange reconnection of closed field in the base with impacted ambient open field, and the upper product of this reconnection is the jet-outflow spire. It is also observed that in most jets of either kind the spire drifts sideways away from the bright nodule. We present the observed bright nodule and spire drift in an example standard jet and in two example blowout jets. With cartoons of the magnetic field and its reconnection in jets, we point out: (1) if the bright nodule is a compact flare arcade made by interchange reconnection, then the spire should drift toward the bright nodule, and (2) if the bright nodule is instead a compact flare arcade made, as in a filament-eruption flare, by internal reconnection of the legs of the erupting sheared-field core of a lobe of the closed field in the base, then the spire, made by the interchange reconnection that is driven on the outside of that lobe by the lobe’s internal convulsion, should drift away from the bright nodule. Therefore, from the observation that the spire usually drifts away from the bright nodule, we infer: (1) in X-ray/EUV jets of either kind in coronal holes the interchange reconnection that generates the jet-outflow spire usually does not make the bright nodule; instead, the bright nodule is made by reconnection inside erupting closed field in the base, as in a filament eruption, the eruption being either a confined eruption for a standard jet or a blowout eruption (as

  3. Ground Control for Emplacement Drifts for SR

    SciTech Connect

    Y. Sun

    2000-04-07

    This analysis demonstrates that a satisfactory ground control system can be designed for the Yucca Mountain site, and provides the technical basis for the design of ground support systems to be used in repository emplacement and non-emplacement drifts. The repository ground support design was based on analytical methods using acquired computer codes, and focused on the final support systems. A literature review of case histories, including the lessons learned from the design and construction of the ESF, the studies on the seismic damages of underground openings, and the use of rock mass classification systems in the ground support design, was conducted (Sections 6.3.4 and 6.4). This review provided some basis for determining the inputs and methodologies used in this analysis. Stability of the supported and unsupported emplacement and non-emplacement drifts was evaluated in this analysis. The excavation effects (i.e., state of the stress change due to excavation), thermal effects (i.e., due to heat output from waste packages), and seismic effects (i.e., from potential earthquake events) were evaluated, and stress controlled modes of failure were examined for two in situ stress conditions (k_0=0.3 and 1.0) using rock properties representing rock mass categories of 1 and 5. Variation of rock mass units such as the non-lithophysal (Tptpmn) and lithophysal (Tptpll) was considered in the analysis. The focus was on the non-lithophysal unit because this unit appears to be relatively weaker and has much smaller joint spacing. Therefore, the drift stability and ground support needs were considered to be controlled by the design for this rock unit. The ground support systems for both emplacement and non-emplacement drifts were incorporated into the models to assess their performance under in situ, thermal, and seismic loading conditions. Both continuum and discontinuum modeling approaches were employed in the analyses of the rock mass behavior and in the evaluation of the

  4. Abstraction of Drift-Scale Coupled Processes

    SciTech Connect

    N.D. Francis; D. Sassani

    2000-03-31

    This Analysis/Model Report (AMR) describes an abstraction, for the performance assessment total system model, of the near-field host rock water chemistry and gas-phase composition. It also provides an abstracted process model analysis of potentially important differences in the thermal hydrologic (TH) variables used to describe the performance of a geologic repository obtained from models that include fully coupled reactive transport with thermal hydrology and those that include thermal hydrology alone. Specifically, the motivation of the process-level model comparison between fully coupled thermal-hydrologic-chemical (THC) and thermal-hydrologic-only (TH-only) is to provide the necessary justification as to why the in-drift thermodynamic environment and the near-field host rock percolation flux, the essential TH variables used to describe the performance of a geologic repository, can be obtained using a TH-only model and applied directly into a TSPA abstraction without recourse to a fully coupled reactive transport model. Abstraction as used in the context of this AMR refers to an extraction of essential data or information from the process-level model. The abstraction analysis reproduces and bounds the results of the underlying detailed process-level model. The primary purpose of this AMR is to abstract the results of the fully-coupled, THC model (CRWMS M&O 2000a) for effects on water and gas-phase composition adjacent to the drift wall (in the near-field host rock). It is assumed that drift wall fracture water and gas compositions may enter the emplacement drift before, during, and after the heating period. The heating period includes both the preclosure, in which the repository drifts are ventilated, and the postclosure periods, with backfill and drip shield emplacement at the time of repository closure. Although the preclosure period (50 years) is included in the process models, the postclosure performance assessment starts at the end of this initial period

  5. Airborne organophosphate pesticides drift in Mediterranean climate: The importance of secondary drift

    NASA Astrophysics Data System (ADS)

    Zivan, Ohad; Segal-Rosenheimer, Michal; Dubowski, Yael

    2016-02-01

    Pesticide application is a short-term air-pollution episode with near and far field effects due to atmospheric drift. In order to better evaluate resulting air concentrations in nearby communities following pesticide application, measurements of airborne pesticides were conducted at ∼70 m from field edge. This was done following three different application events of the organophosphate pesticide Chlorpyrifos in a persimmon orchard. Complementary information on larger spatial scale was obtained using CALPUFF modeling in which application and meteorological data was used to better evaluate dispersion patterns. Measurements indicated high airborne concentrations during application hours (few μg m-3 for 8 h average), which dropped to tens of ng m-3 in the following days. Measured atmospheric concentrations show that secondary drift (i.e., post-application drift) involves significant loads of pesticides and hence should not be ignored in exposure considerations. Furthermore, CALPUFF modeling revealed the complex dispersion pattern when weak winds prevailed, and showed that during the 24 h after application air concentrations reached levels above the hourly Texas effect screening level (0.1 μg m-3). Interestingly, weak winds on the night after application resulted in a secondary peak in measured and modeled air concentrations. Long exposure time (when secondary drift is considered) and concentrations measured following such common air-assisted orchard application, suggest pesticide drift may have health repercussions that are currently unknown, and emphasize the need for further epidemiological studies.

  6. Evaluating Public Access On-Line Catalogs. Phase I: Development and Testing of Data Collection and Analysis Tools. Final Report.

    ERIC Educational Resources Information Center

    Larson, Ray R.

    This report outlines specifications for the online transaction monitoring and questionnaire administration features of the University of California's (UC) Prototype On-Line Catalog, known as MELVYL. The development and testing of these features by the UC Division of Library Automation (DLA) is also described. This document is the final report…

  7. Pressurized drift tubes scintillating fiber hadron calorimetry. Final report

    SciTech Connect

    Bromberg, C.; Huston, J.; Miller, R.

    1995-03-22

    Under this contract members of the MSU high energy physics group constructed a full-scale Pressurized Drift Tube Chamber intended for the GEM muon system at the SSC. They achieved a position resolution of <90 {mu} over the full 5 m{sup 2} area of the detector. This resolution satisfied the GEM resolution requirements of <100 {mu} by a comfortable margin. Based on their SSC work they developed a new technique for creating wire supports in drift tubes with an overall placement accuracy of <20 {mu}. This technique requires only simple jigging and can be duplicated and operated at low cost. Also, they participated in the design and testing of a hadron calorimeter prototype for GEM. This work lead the authors to develop a semi-automatic welding machine to fuse together two plastic optical fibers. Copies of this machine are currently in use in the CDF endplug upgrade at Fermilab and additional copies are used widely in calorimeter and fiber-tracker construction.

  8. Forward Drift Chambers for the GlueX experiment

    NASA Astrophysics Data System (ADS)

    Pentchev, Lubomir; GlueX Collaboration

    2014-09-01

    The GlueX experiment will search for exotic mesons produced by 9 GeV linearly polarized photon beam from the 12 GeV CEBAF machine. A hermetic solenoid-based detector system that includes tracking and calorimetry has been constructed. The Forward Drift Chamber (FDC) system consists of 24 circular planar drift chambers of 1 m diameter. Additional information from cathode strips, placed at both sides of the wire planes, is required to achieve efficient pattern recognition in the presence of high background rates in forward direction, resulting in 12,500 readout channels in total. The detection of relatively low energy photons by the electro-magnetic calorimeters imposes severe constraints on the amount of the material used in the FDC. Challenges in the production of this low-mass detector will be discussed. The FDC has been completed and recently installed in the bore of the solenoid magnet. Results from the tests of the whole detector system will be presented.

  9. A drifting GPS buoy for retrieving effective riverbed bathymetry

    NASA Astrophysics Data System (ADS)

    Hostache, R.; Matgen, P.; Giustarini, L.; Teferle, F. N.; Tailliez, C.; Iffly, J.-F.; Corato, G.

    2015-01-01

    Spatially distributed riverbed bathymetry information are rarely available but mandatory for accurate hydrodynamic modeling. This study aims at evaluating the potential of the Global Navigation Satellite System (GNSS), like for instance Global Positioning System (GPS), for retrieving such data. Drifting buoys equipped with navigation systems such as GPS enable the quasi-continuous measurement of water surface elevation, from virtually any point in the world. The present study investigates the potential of assimilating GNSS-derived water surface elevation measurements into hydraulic models in order to retrieve effective riverbed bathymetry. First tests with a GPS dual-frequency receiver show that the root mean squared error (RMSE) on the elevation measurement equals 30 cm provided that a differential post processing is performed. Next, synthetic observations of a drifting buoy were generated assuming a 30 cm average error of Water Surface Elevation (WSE) measurements. By assimilating the synthetic observation into a 1D-Hydrodynamic model, we show that the riverbed bathymetry can be retrieved with an accuracy of 36 cm. Moreover, the WSEs simulated by the hydrodynamic model using the retrieved bathymetry are in good agreement with the synthetic "truth", exhibiting an RMSE of 27 cm.

  10. Measurements Verifying the Optics of the Electron Drift Instrument

    NASA Astrophysics Data System (ADS)

    Kooi, Vanessa; Kletzing, Craig; Bounds, Scott; Sigsbee, Kristine M.

    2015-04-01

    Magnetic reconnection is the process of breaking and reconnecting of opposing magnetic field lines, and is often associated with tremendous energy transfer. The energy transferred by reconnection directly affects people through its influence on geospace weather and technological systems - such as telecommunication networks, GPS, and power grids. However, the mechanisms that cause magnetic reconnection are not well understood. The Magnetospheric Multi-Scale Mission (MMS) will use four spacecraft in a pyramid formation to make three-dimensional measurements of the structures in magnetic reconnection occurring in the Earth's magnetosphere.The spacecraft will repeatedly sample these regions for a prolonged period of time to gather data in more detail than has been previously possible. MMS is scheduled to be launched in March of 2015. The Electron Drift Instrument (EDI) will be used on MMS to measure the electric fields associated with magnetic reconnection. The EDI is a device used on spacecraft to measure electric fields by emitting an electron beam and measuring the E x B drift of the returning electrons after one gyration. This paper concentrates on measurements of the EDI’s optics system. The testing process includes measuring the optics response to a uni-directional electron beam. These measurements are used to verify the response of the EDI's optics and to allow for the optimization of the desired optics state. The measurements agree well with simulations and we are confident in the performance of the EDI instrument.

  11. Geotechnical characterization for the Main Drift of the Exploratory Studies Facility

    SciTech Connect

    Kicker, D.C.; Martin, E.R.; Brechtel, C.E.; Stone, C.A.; Kessel, D.S.

    1997-07-01

    Geotechnical characterization of the Main Drift of the Exploratory Studies Facility was based on borehole data collected in site characterization drilling and on scanline rock mass quality data collected during the excavation of the North Ramp. The Main Drift is the planned 3,131-m near-horizontal tunnel to be excavated at the potential repository horizon for the Yucca Mountain Site Characterization Project. Main Drift borehole data consisted of three holes--USW SD-7, SD-9, and SD-12--drilled along the tunnel alignment. In addition, boreholes USW UZ-14, NRG-6, and NRG-7/7A were used to supplement the database on subsurface rock conditions. Specific data summarized and presented included lithologic and rock structure core logs, rock mechanics laboratory testing, and rock mass quality indices. Cross sections with stratigraphic and thermal-mechanical units were also presented. Topics discussed in the report include geologic setting, geologic features of engineering and construction significance, anticipated ground conditions, and the range of required ground support. Rock structural and rock mass quality data have been developed for each 3-m interval of core in the middle nonlithophysal stratigraphic zone of the Topopah Spring Tuff Formation. The distribution of the rock mass quality data in all boreholes used to characterize the Main Drift was assumed to be representative of the variability of the rock mass conditions to be encountered in the Main Drift. Observations in the North Ramp tunnel have been used to project conditions in the lower lithophysal zone and in fault zones.

  12. Drift-driven evolution of electric signals in a Neotropical knifefish.

    PubMed

    Picq, Sophie; Alda, Fernando; Bermingham, Eldredge; Krahe, Rüdiger

    2016-09-01

    Communication signals are highly diverse traits. This diversity is usually assumed to be shaped by selective forces, whereas the null hypothesis of divergence through drift is often not considered. In Panama, the weakly electric fish Brachyhypopomus occidentalis is widely distributed in multiple independent drainage systems, which provide a natural evolutionary laboratory for the study of genetic and signal divergence in separate populations. We quantified geographic variation in the electric signals of 109 fish from five populations, and compared it to the neutral genetic variation estimated from cytochrome oxidase I (COI) sequences of the same individuals, to test whether drift may be driving divergence of their signals. Signal distances were highly correlated with genetic distances, even after controlling for geographic distances, suggesting that drift alone is sufficient to explain geographic variation in electric signals. Significant differences at smaller geographic scales (within drainages) showed, however, that electric signals may evolve at a faster rate than expected under drift, raising the possibility that additional adaptive forces may be contributing to their evolution. Overall, our data point to stochastic forces as main drivers of signal evolution in this species and extend the role of drift in the evolution of communication systems to fish and electrocommunication.

  13. Ionospheric vertical drift response at a mid-latitude station

    NASA Astrophysics Data System (ADS)

    Kouba, Daniel; Koucká Knížová, Petra

    2016-07-01

    Vertical plasma drift data measured at a mid-latitude ionospheric station Pruhonice (50.0 ° N, 14.6 ° E) were collected and analysed for the year 2006, a year of low solar and geomagnetic activity. Hence these data provide insight into the drift behaviour during quiet conditions. The following typical diurnal trend is evident: a significant decay to negative values (downward peak) at dawn; generally less pronounced downward peak at dusk hours. Magnitude of the downward drift varies during the year. Typically it reaches values about 20 ms-1 at dawn hours and 10 ms-1 at dusk hours. Maximum dawn magnitude of about 40 ms-1 has been detected in August. During daytime the vertical drifts increases from the initial small downward drifts to zero drift around noon and to small upward drifts in the afternoon. Night-time drift values display large variability around a near zero vertical drift average. There is a significant trend to larger downward drift values near dawn and a less pronounced decrease of the afternoon upward vertical drifts near sunset. Two regular downward peaks of the drift associated with the dawn and dusk are general characteristics of the analysed data throughout the year 2006. Their seasonal course corresponds to the seasonal course of the sunrise and sunset. The duration of prevailing negative drift velocities forming these peaks and thus the influence of the dawn/dusk on the drift velocity is mostly 1.5-3 h. The dawn effect on vertical drift tends to be larger than the effect of the dusk. The observed magnitude of the sunrise and sunset peaks show significant annual course. The highest variability of the magnitude is seen during winter. High variability is detected till March equinox and again after September equinox. Around solstice, both peaks reaches lowest values. After that, the magnitudes of the drift velocity increase smoothly till maxima in summer (August). The vertical drift velocity course is smooth between June solstice and September

  14. A new low drift integrator system for the Experiment Advanced Superconductor Tokamak.

    PubMed

    Liu, D M; Wan, B N; Wang, Y; Wu, Y C; Shen, B; Ji, Z S; Luo, J R

    2009-05-01

    A new type of the integrator system with the low drift characteristic has been developed to accommodate the long pulse plasma discharges on Experiment Advanced Superconductor Tokamak (EAST). The integrator system is composed of the Ethernet control module and the integral module which includes one integrator circuit, followed by two isolation circuits and two program-controlled amplifier circuits. It compensates automatically integration drift and is applied in real-time control. The performance test and the experimental results in plasma discharges show that the developed integrator system can meet the requirements of plasma control on the accuracy and noise level of the integrator in long pulse discharges.

  15. 40 CFR 1065.550 - Gas analyzer range validation and drift validation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Gas analyzer range validation and... Cycles § 1065.550 Gas analyzer range validation and drift validation. (a) Range validation. If an analyzer operated above 100% of its range at any time during the test, perform the following steps: (1)...

  16. The Impact of Multidirectional Item Parameter Drift on IRT Scaling Coefficients and Proficiency Estimates

    ERIC Educational Resources Information Center

    Han, Kyung T.; Wells, Craig S.; Sireci, Stephen G.

    2012-01-01

    Item parameter drift (IPD) occurs when item parameter values change from their original value over time. IPD may pose a serious threat to the fairness and validity of test score interpretations, especially when the goal of the assessment is to measure growth or improvement. In this study, we examined the effect of multidirectional IPD (i.e., some…

  17. Rater Effects on Essay Scoring: A Multilevel Analysis of Severity Drift, Central Tendency, and Rater Experience

    ERIC Educational Resources Information Center

    Leckie, George; Baird, Jo-Anne

    2011-01-01

    This study examined rater effects on essay scoring in an operational monitoring system from England's 2008 national curriculum English writing test for 14-year-olds. We fitted two multilevel models and analyzed: (1) drift in rater severity effects over time; (2) rater central tendency effects; and (3) differences in rater severity and central…

  18. Evaluation of the EPA Drift Reduction Technology (DRT) low-speed wind tunnel protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The EPA’s proposed Drift Reduction Technology low-speed wind tunnel evaluation protocol was tested across a series of modified ASAE reference nozzles. Both droplet size and deposition and flux volume measurements were made downwind from the nozzles operating in the tunnel at airspeeds of 1 and 2.5 ...

  19. Negative Ion Drift Velocity and Longitudinal Diffusion in Mixtures of Carbon Disulfide and Methane

    NASA Technical Reports Server (NTRS)

    Dion, Michael P.; Son, S.; Hunter, S. D.; deNolfo, G. A.

    2011-01-01

    Negative ion drift velocity and longitudinal diffusion has been measured for gas mixtures of carbon disulfide (CS2) and methane (CH4)' Measurements were made as a function of total pressure, CS2 partial pressure and electric field. Constant mobility and thermal-limit longitudinal diffusion is observed for all gas mixtures tested. Gas gain for some of the mixtures is also included.

  20. Determination of Importance Evaluation for the ESF Enhanced Charcterization of the Repository Block Cross Drift

    SciTech Connect

    S. Goodin

    2002-01-09

    The objective of this DIE is to determine whether the ECRB-Cross-Drift-related activities, as identified in Section 6.0, could potentially impact (1) Yucca Mountain Site Characterization Project (YMP) testing or (2) the waste isolation capabilities of a potential repository at the Yucca Mountain site. Any controls necessary to limit such potential impacts are also identified herein.

  1. An Examination of Two Procedures for Identifying Consequential Item Parameter Drift

    ERIC Educational Resources Information Center

    Wells, Craig S.; Hambleton, Ronald K.; Kirkpatrick, Robert; Meng, Yu

    2014-01-01

    The purpose of the present study was to develop and evaluate two procedures flagging consequential item parameter drift (IPD) in an operational testing program. The first procedure was based on flagging items that exhibit a meaningful magnitude of IPD using a critical value that was defined to represent barely tolerable IPD. The second procedure…

  2. An Augmented SMS Intervention to Improve Access to Antenatal CD4 Testing and ART Initiation in HIV-Infected Pregnant Women: A Cluster Randomized Trial

    PubMed Central

    Dryden-Peterson, Scott; Bennett, Kara; Hughes, Michael D.; Veres, Adrian; John, Oaitse; Pradhananga, Rosina; Boyer, Matthew; Brown, Carolyn; Sakyi, Bright; van Widenfelt, Erik; Keapoletswe, Koona; Mine, Madisa; Moyo, Sikhulile; Asmelash, Aida; Siedner, Mark; Mmalane, Mompati; Shapiro, Roger L.; Lockman, Shahin

    2015-01-01

    Background Less than one-third of HIV-infected pregnant women eligible for combination antiretroviral therapy (ART) globally initiate treatment prior to delivery, with lack of access to timely CD4 results being a principal barrier. We evaluated the effectiveness of an SMS-based intervention to improve access to timely antenatal ART. Methods We conducted a stepped-wedge cluster randomized trial of a low-cost programmatic intervention in 20 antenatal clinics in Gaborone, Botswana. From July 2011-April 2012, 2 clinics were randomly selected every 4 weeks to receive an ongoing clinic-based educational intervention to improve CD4 collection and to receive CD4 results via an automated SMS platform with active patient tracing. CD4 testing before 26 weeks gestation and ART initiation before 30 weeks gestation were assessed. Results Three-hundred-sixty-six ART-naïve women were included, 189 registering for antenatal care under Intervention and 177 under Usual Care periods. Of CD4-eligible women, 100 (59.2%) women under Intervention and 79 (50.6%) women under Usual Care completed CD4 phlebotomy before 26 weeks gestation, adjusted odds ratio (aOR, adjusted for time that a clinic initiated Intervention) 0.87 (95% confidence interval [CI]0.47–1.63, P = 0.67). The SMS-based platform reduced time to clinic receipt of CD4 test result from median of 16 to 6 days (P<0.001), was appreciated by clinic staff, and was associated with reduced operational cost. However, rates of ART initiation remained low, with 56 (36.4%) women registering under Intervention versus 37 (24.2%) women under Usual Care initiating ART prior to 30 weeks gestation, aOR 1.06 (95%CI 0.53–2.13, P = 0.87). Conclusions The augmented SMS-based intervention delivered CD4 results more rapidly and efficiently, and this type of SMS-based results delivery platform may be useful for a variety of tests and settings. However, the intervention did not appear to improve access to timely antenatal CD4 testing or ART

  3. Demersally drifting invertebrates from Kongsfjorden, Svalbård (Arctic Ocean)-a comparison of catches from drift-pump and drift-nets

    NASA Astrophysics Data System (ADS)

    Dahms, Hans-Uwe; Joo, Hyoung-Min; Lee, Jae Hyung; Yun, Mi Sun; Ahn, So Hyun; Lee, Sang Heon

    2015-12-01

    Demersally drifting organisms were collected at Ny Ålesund (Svalbård-Arctic Ocean) to study the taxon composition and relative abundances in the Arctic summer. Catch potentials of two collection devices for demersal drift were compared. A lowvolume submersible drift-pump and a drift-net unit were employed for the collection of demersally drifting biota, particularly for shallow aquatic habitats. With the exception of Appendicularia, Chaetognatha, Coelenterata, and Ctenophora, which were damaged at times, the pump catches were in good condition and sufficient for identification and quantification of less mobile fauna. A comparison of the two devices revealed that the drift-pump collected more specimens than the drift-net. However, the drift-net may have caused an underestimation of the abundances of invertebrates. No differences in identified taxon number and indices of richness, evenness and diversity were found. However, the proportion of invertebrate animals in the two devices was different for the three groups: zooplankton, macrofauna and meiofauna. At Svalbård, zooplankton, larvae of macrofauna, and meiofauna were successfully collected by the two collecting devices. However, the catchibility of the two devices in collecting various invertebrate taxa was different and, therefore, a sound `Device Effect' was revealed.

  4. The Mark II Vertex Drift Chamber

    SciTech Connect

    Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.

    1989-03-01

    We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.

  5. Effects of grids in drift tubes

    SciTech Connect

    Okamura M.; Yamauchi, H.

    2012-05-20

    In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical discharge machining (EDM). The 3D electric field of the grid was simulated.

  6. Drift Chamber Alignment using Cosmic Rays

    SciTech Connect

    Kotwal, Ashutosh V.; Hays, Christopher P.

    2014-05-07

    The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers, and a muon detector system. We present a technique for, and results of, a precise relative alignment of the drift chamber wires of the CDF tracker. This alignment has been an important component of the track momentum calibration, which is the basis for the charged-lepton calibration for the measurement of the W boson mass at CDF.

  7. Strange Attractors in Drift Wave Turbulence

    SciTech Connect

    Jerome L.V. Lewandowski

    2003-09-03

    There are growing experimental, numerical and theoretical evidences that the anomalous transport observed in tokamaks and stellarators is caused by slow, drift-type modes (such as trapped electron modes and ion-temperature gradient-driven modes). Although typical collision frequencies in hot, magnetized fusion plasmas can be quite low in absolute values, collisional effects are nevertheless important since they act as dissipative sinks. As it is well known, dissipative systems with many (strictly speaking more than two) degrees of freedom are often chaotic and may evolve towards a so-called attractor.

  8. Drift-induced Benjamin-Feir instabilities

    NASA Astrophysics Data System (ADS)

    Di Patti, F.; Fanelli, D.; Carletti, T.

    2016-06-01

    A modified version of the Ginzburg-Landau equation is introduced which accounts for asymmetric couplings between neighbors sites on a one-dimensional lattice, with periodic boundary conditions. The drift term which reflects the imposed microscopic asymmetry seeds a generalized class of instabilities, reminiscent of the Benjamin-Feir type. The uniformly synchronized solution is spontaneously destabilized outside the region of parameters classically associated to the Benjamin-Feir instability, upon injection of a nonhomogeneous perturbation. The ensuing patterns can be of the traveling wave type or display a patchy, colorful mosaic for the modulus of the complex oscillators amplitude.

  9. MAGSAT anomaly map and continental drift

    NASA Technical Reports Server (NTRS)

    Lemouel, J. L. (Principal Investigator); Galdeano, A.; Ducruix, J.

    1981-01-01

    Anomaly maps of high quality are needed to display unambiguously the so called long wave length anomalies. The anomalies were analyzed in terms of continental drift and the nature of their sources is discussed. The map presented confirms the thinness of the oceanic magnetized layer. Continental magnetic anomalies are characterized by elongated structures generally of east-west trend. Paleomagnetic reconstruction shows that the anomalies found in India, Australia, and Antarctic exhibit a fair consistency with the African anomalies. It is also shown that anomalies are locked under the continents and have a fixed geometry.

  10. A drift model of interchange instability

    SciTech Connect

    Benilov, E. S.; Power, O. A.

    2007-08-15

    A set of asymptotic equations is derived, describing the dynamics of the flute mode in a magnetized plasma with cold ions, under a 'local' approximation (i.e., near a particular point). The asymptotic set is then used to calculate the growth rate of interchange instability in the slab model. It is shown that, unlike the magnetohydrodynamic ordering, the drift one allows instability to occur for either sign of the pressure gradient (i.e., for both 'bad' and 'good' curvature of the magnetic field). It is also demonstrated that finite beta gives rise to an extra instability that does not exist in the small-beta limit.

  11. Drift-Alfven eigenmodes in inhomogeneous plasma

    SciTech Connect

    Vranjes, J.; Poedts, S.

    2006-03-15

    A set of three nonlinear equations describing drift-Alfven waves in a nonuniform magnetized plasma is derived and discussed both in linear and nonlinear limits. In the case of a cylindric radially bounded plasma with a Gaussian density distribution in the radial direction the linearized equations are solved exactly yielding general solutions for modes with quantized frequencies and with radially dependent amplitudes. The full set of nonlinear equations is also solved yielding particular solutions in the form of rotating radially limited structures. The results should be applicable to the description of electromagnetic perturbations in solar magnetic structures and in astrophysical column-like objects including cosmic tornados.

  12. Effective drifts in dynamical systems with multiplicative noise: a review of recent progress.

    PubMed

    Volpe, Giovanni; Wehr, Jan

    2016-05-01

    Noisy dynamical models are employed to describe a wide range of phenomena. Since exact modeling of these phenomena requires access to their microscopic dynamics, whose time scales are typically much shorter than the observable time scales, there is often need to resort to effective mathematical models such as stochastic differential equations (SDEs). In particular, here we consider effective SDEs describing the behavior of systems in the limits when natural time scales become very small. In the presence of multiplicative noise (i.e. noise whose intensity depends upon the system's state), an additional drift term, called noise-induced drift or effective drift, appears. The nature of this noise-induced drift has been recently the subject of a growing number of theoretical and experimental studies. Here, we provide an extensive review of the state of the art in this field. After an introduction, we discuss a minimal model of how multiplicative noise affects the evolution of a system. Next, we consider several case studies with a focus on recent experiments: the Brownian motion of a microscopic particle in thermal equilibrium with a heat bath in the presence of a diffusion gradient; the limiting behavior of a system driven by a colored noise modulated by a multiplicative feedback; and the behavior of an autonomous agent subject to sensorial delay in a noisy environment. This allows us to present the experimental results, as well as mathematical methods and numerical techniques, that can be employed to study a wide range of systems. At the end we give an application-oriented overview of future projects involving noise-induced drifts, including both theory and experiment.

  13. Effective drifts in dynamical systems with multiplicative noise: a review of recent progress

    NASA Astrophysics Data System (ADS)

    Volpe, Giovanni; Wehr, Jan

    2016-05-01

    Noisy dynamical models are employed to describe a wide range of phenomena. Since exact modeling of these phenomena requires access to their microscopic dynamics, whose time scales are typically much shorter than the observable time scales, there is often need to resort to effective mathematical models such as stochastic differential equations (SDEs). In particular, here we consider effective SDEs describing the behavior of systems in the limits when natural time scales become very small. In the presence of multiplicative noise (i.e. noise whose intensity depends upon the system’s state), an additional drift term, called noise-induced drift or effective drift, appears. The nature of this noise-induced drift has been recently the subject of a growing number of theoretical and experimental studies. Here, we provide an extensive review of the state of the art in this field. After an introduction, we discuss a minimal model of how multiplicative noise affects the evolution of a system. Next, we consider several case studies with a focus on recent experiments: the Brownian motion of a microscopic particle in thermal equilibrium with a heat bath in the presence of a diffusion gradient; the limiting behavior of a system driven by a colored noise modulated by a multiplicative feedback; and the behavior of an autonomous agent subject to sensorial delay in a noisy environment. This allows us to present the experimental results, as well as mathematical methods and numerical techniques, that can be employed to study a wide range of systems. At the end we give an application-oriented overview of future projects involving noise-induced drifts, including both theory and experiment.

  14. Testing the importance of family solidarity, community structure, information access, and social capital in predicting nutrition health knowledge and food choices in the Philippines.

    PubMed

    Moxley, Robert L; Jicha, Karl A; Thompson, Gretchen H

    2011-01-01

    This study investigates the influence of family solidarity, community structure, information access, social capital, and socioeconomic status on the extent of nutrition and health knowledge (NHK) among primary household meal planners. In turn, we pose the question: does this knowledge influence dietary decision making? Data are taken from a survey determining socioeconomic impacts of vitamin A fortified peanut butter on Philippine households. Questions on the relationships of nutrition to health were selected to construct a knowledge index on which household respondents could be ranked. We then tested hypotheses regarding what types of individual, family-level, and community structural characteristics would predict performance on this index. The results indicate that the strongest predictors of NHK come from sociological theory related to family solidarity and community centrality, in addition to information accessibility and household income. Our findings also indicate that NHK influences dietary choices with regard to the purchase of a vitamin fortified staple food product, which is essential when addressing nutritional deficiency problems in developing countries.

  15. Web Accessibility and Accessibility Instruction

    ERIC Educational Resources Information Center

    Green, Ravonne A.; Huprich, Julia

    2009-01-01

    Section 508 of the Americans with Disabilities Act (ADA) mandates that programs and services be accessible to people with disabilities. While schools of library and information science (SLIS*) and university libraries should model accessible Web sites, this may not be the case. This article examines previous studies about the Web accessibility of…

  16. Access to Diagnostic Tests and Essential Medicines for Cardiovascular Diseases and Diabetes Care: Cost, Availability and Affordability in the West Region of Cameroon

    PubMed Central

    Jingi, Ahmadou M.; Noubiap, Jean Jacques N.; Ewane Onana, Arnold; Nansseu, Jobert Richie N.; Wang, Binhuan; Kingue, Samuel; Kengne, André Pascal

    2014-01-01

    Objective To assess the availability and affordability of medicines and routine tests for cardiovascular disease (CVD) and diabetes in the West region of Cameroon, a low-income setting. Methods A survey was conducted on the availability and cost of twelve routine tests and twenty medicines for CVD and diabetes in eight health districts (four urban and four rural) covering over 60% of the population of the region (1.8 million). We analyzed the percentage of tests and medicines available, the median price against the international reference price (median price ratio) for the medicines, and affordability in terms of the number of days’ wages it would cost the lowest-paid unskilled government worker for initial investigation tests and procurement for one month of treatment. Results The availability of tests varied between 10% for the ECG to 100% for the fasting blood sugar. The average cost for the initial investigation using the minimum tests cost 29.76 days’ wages. The availability of medicines varied from 36.4% to 59.1% in urban and from 9.1% to 50% in rural settings. Only metformin and benzathine-benzylpenicilline had a median price ratio of ≤1.5, with statins being largely unaffordable (at least 30.51 days’ wages). One month of combination treatment for coronary heart disease costs at least 40.87 days’ wages. Conclusion The investigation and management of patients with medium-to-high cardiovascular risk remains largely unavailable and unaffordable in this setting. An effective non-communicable disease program should lay emphasis on primary prevention, and improve affordable access to essential medicines in public outlets. PMID:25369455

  17. Prospective assessment of rapid diagnostic tests for the detection of antibodies to hepatitis C virus, a tool for improving access to care.

    PubMed

    Chevaliez, S; Poiteau, L; Rosa, I; Soulier, A; Roudot-Thoraval, F; Laperche, S; Hézode, C; Pawlotsky, J-M

    2016-05-01

    Large-scale hepatitis C screening is required to prevent further spread of the infection, improve access to care in the context of new hepatitis C virus (HCV) drug regimens without interferon-alpha and subsequently reduce the risk of long-term complications of chronic liver disease. Rapid diagnostic tests (RDTs) represent an attractive alternative to enzyme immunoassay using blood from venepuncture. The aim of the present study was to prospectively assess the clinical performance of CE-marked RDTs detecting anti-HCV antibodies in fingerstick capillary whole blood and/or oral fluid. A total of 513 individuals, including 318 patients with chronic HCV infection, 25 patients with resolved HCV infection and 170 HCV-seronegative individuals, were prospectively enrolled. The specificity of RDTs with fingerstick whole blood varied from 98.8% to 100%. The clinical sensitivity was high for the OraQuick(®) and Toyo(®) tests (99.4% and 95.8%, respectively), but low for the Labmen(®) test (63.1%). The specificity and clinical sensitivity in crevicular fluid were both satisfactory for the OraQuick(®) test (100% and 97.6%, respectively). HCV antibody RDTs were easy and rapid to perform in the context of patient care. They were highly specific. Both the OraQuick(®) and Toyo(®) tests reached the expected level of performance for wide-scale use, with a performance advantage for the OraQuick(®) HCV test. RDTs appear to be a promising new tool for wide-scale screening of HCV infection in high-risk to medium-risk populations. Hence, careful assessment of the performance of HCV RDTs must be recommended before they can be implemented in clinical practice.

  18. Access to Healthcare, HIV/STI Testing, and Preferred Pre-Exposure Prophylaxis Providers among Men Who Have Sex with Men and Men Who Engage in Street-Based Sex Work in the US

    PubMed Central

    Underhill, Kristen; Morrow, Kathleen M.; Colleran, Christopher M.; Holcomb, Richard; Operario, Don; Calabrese, Sarah K.; Galárraga, Omar; Mayer, Kenneth H.

    2014-01-01

    Background Pre-exposure prophylaxis (PrEP) is a promising strategy for HIV prevention among men who have sex with men (MSM) and men who engage in sex work. But access will require routine HIV testing and contacts with healthcare providers. This study investigated men’s healthcare and HIV testing experiences to inform PrEP implementation. Methods We conducted 8 focus groups (n = 38) in 2012 and 56 in-depth qualitative interviews in 2013–14 with male sex workers (MSWs) (n = 31) and other MSM (n = 25) in Providence, RI. MSWs primarily met clients in street-based sex work venues. Facilitators asked participants about access to healthcare and HIV/STI testing, healthcare needs, and preferred PrEP providers. Results MSWs primarily accessed care in emergency rooms (ERs), substance use clinics, correctional institutions, and walk-in clinics. Rates of HIV testing were high, but MSWs reported low access to other STI testing, low insurance coverage, and unmet healthcare needs including primary care, substance use treatment, and mental health services. MSM not engaging in sex work were more likely to report access to primary and specialist care. Rates of HIV testing among these MSM were slightly lower, but they reported more STI testing, more insurance coverage, and fewer unmet needs. Preferred PrEP providers for both groups included primary care physicians, infectious disease specialists, and psychiatrists. MSWs were also willing to access PrEP in substance use treatment and ER settings. Conclusions PrEP outreach efforts for MSWs and other MSM should engage diverse providers in many settings, including mental health and substance use treatment, ERs, needle exchanges, correctional institutions, and HIV testing centers. Access to PrEP will require financial assistance, but can build on existing healthcare contacts for both populations. PMID:25386746

  19. Genetic variability in residual feed intake in rainbow trout clones and testing of indirect selection criteria (Open Access publication)

    PubMed Central

    Grima, Laure; Quillet, Edwige; Boujard, Thierry; Robert-Granié, Christèle; Chatain, Béatrice; Mambrini, Muriel

    2008-01-01

    Little is known about the genetic basis of residual feed intake (RFI) variation in fish, since this trait is highly sensitive to environmental influences, and feed intake of individuals is difficult to measure accurately. The purpose of this work was (i) to assess the genetic variability of RFI estimated by an X-ray technique and (ii) to develop predictive criteria for RFI. Two predictive criteria were tested: loss of body weight during feed deprivation and compensatory growth during re-feeding. Ten heterozygous rainbow trout clones were used. Individual intake and body weight were measured three times at threeweek intervals. Then, individual body weight was recorded after two cycles of a three-week feed deprivation followed by a three-week re-feeding. The ratio of the genetic variance to the phenotypic variance was found high to moderate for growth, feed intake, and RFI (VG/VP = 0.63 ± 0.11, 0.29 ± 0.11, 0.29 ± 0.09, respectively). The index that integrates performances achieved during deprivation and re-feeding periods explained 59% of RFI variations. These results provide a basis for further studies on the origin of RFI differences and show that indirect criteria are good candidates for future selective breeding programs. PMID:18990354

  20. Coherent Vortex Evolution in Drift Wave Turbulence

    NASA Astrophysics Data System (ADS)

    Gatto, R.; Terry, P. W.

    1998-11-01

    Localized structures in turbulence are subject to loss of coherence by mixing. Phase space structures, such as drift-hole, (P. W. Terry, P. H. Diamond, T. S. Hahm, Phys. Fluids B) 2 9 2048 (1990) possess a self-electric field, which if sufficiently large maintains particle trapping against the tidal deformations of ambient turbulence. We show here that intense vortices in fluid drift wave turbulence avoid mixing by suppressing ambient turbulence with the strong flow shear of the vortex edge. Analysis of turbulence evolution in the vortex edge recovers Rapid Distortion Theory (G. K. Batchelor and I. Proudman, Q. J. Mech. Appl. Math.) 7 83 (1954) as the short time limit and the shear suppression scaling theory (H. Biglari, P. H. Diamond and P. W. Terry, Phys. Fluids B) 2 1 (1990) as the long time limit. Shear suppression leads to an amplitude condition for coherence and delineates the Gaussian core from the non Gaussian tail of the probability distribution function. The amplitude condition of shear suppression is compared with the trapping condition for phase space holes. The possibility of nonlinear vortex growth will be examined by considering electron dynamics in the vortex evolution.

  1. Silicon drift chamber with extended energy range

    NASA Astrophysics Data System (ADS)

    Labanti, Claudio; Dal Fiume, Daniele; Fiorini, Carlo; Longoni, Antonio; Mauri, Alessandro; Perotti, Francesco; Rossi, Elio; Stephen, John B.

    2000-12-01

    The requirement for future X-ray Astronomy instrumentation to exhibit a combination of good energy resolution and an extended energy range may be fulfilled by the development of a X ray detectors made from coupling a Silicon Drift Chamber (SDC), to a scintillation crystal. We report on such a detector made with an SDC of 3 mm diameter and using a Caesium Iodide [CsI(Tl)] scintillator. The radiation input window is located on the Si side of the assembly so than soft X-rays are directly detected by the SDC. This allows a minimum threshold of about 1 keV at 0 degrees Celsius to be obtained. The Silicon Drift Chamber acts also as a photodiode able to detect the scintillation light produced by the CsI(Tl), thus extending the energy range of such a device up to some MeV. The discrimination of events between these two detection layers is performed by using a pulse shape discriminator in order to differentiate between the different rise times of the collected charge. The detector concept is discussed on the basis of the results already achieved and the future developments foreseen.

  2. Congenital Ulnar Drift in a Surgeon

    PubMed Central

    McKee, Desirae; Eliasson, Shannon; Griswold, John

    2015-01-01

    Windblown hand is a term used in many instances to describe ulnar deviations of the fingers with or without other malformations. In 1994 Wood reviewed all of the descriptions of cases of windblown hand and pointed out how many variants of congenital ulnar drift there are, suggesting that the many variations seen may all belong to a larger type of arthrogryposis. While the most common cause of ulnar deviation of the fingers is rheumatoid arthritis, it can also be caused by other conditions such as windblown hand or Jaccoud's arthropathy. While most hand surgeons are familiar with presentations of congenital ulnar drift, few of them are knowledgeable about Jaccoud's arthropathy as this is usually discussed within medical communities such as Rheumatology. We present a case of a surgeon who has had noticeable ulnar deviation of the digits at the level of the metacarpophalangeal joint since his early 20s. We propose that the current case is a demonstration of a type of windblown hand that has some hereditary component but is not immediately obvious at birth and presents physically more like Jaccoud's arthropathy than traditional windblown hand. PMID:26167318

  3. Metabolic drift in the aging brain

    PubMed Central

    Ivanisevic, Julijana; Stauch, Kelly L.; Petrascheck, Michael; Benton, H. Paul; Epstein, Adrian A.; Fang, Mingliang; Gorantla, Santhi; Tran, Minerva; Hoang, Linh; Kurczy, Michael E.; Boska, Michael D.; Gendelman, Howard E.; Fox, Howard S.; Siuzdak, Gary

    2016-01-01

    Brain function is highly dependent upon controlled energy metabolism whose loss heralds cognitive impairments. This is particularly notable in the aged individuals and in age-related neurodegenerative diseases. However, how metabolic homeostasis is disrupted in the aging brain is still poorly understood. Here we performed global, metabolomic and proteomic analyses across different anatomical regions of mouse brain at different stages of its adult lifespan. Interestingly, while severe proteomic imbalance was absent, global-untargeted metabolomics revealed an energy metabolic drift or significant imbalance in core metabolite levels in aged mouse brains. Metabolic imbalance was characterized by compromised cellular energy status (NAD decline, increased AMP/ATP, purine/pyrimidine accumulation) and significantly altered oxidative phosphorylation and nucleotide biosynthesis and degradation. The central energy metabolic drift suggests a failure of the cellular machinery to restore metabostasis (metabolite homeostasis) in the aged brain and therefore an inability to respond properly to external stimuli, likely driving the alterations in signaling activity and thus in neuronal function and communication. PMID:27182841

  4. Nonequilibrium statistical mechanics of drifting particles

    PubMed

    Bringuier

    2000-06-01

    This paper describes a method for obtaining nonequilibrium one-particle energy distributions of fermions or bosons. For the program to be carried out, particle transport should occur in the drifting mode in which the average velocity is much lower than the instantaneous velocity. Under this condition, the spectral current density has a drift-diffusion structure involving a mobility-diffusion relationship unrelated to statistics. When a local-equilibrium energy distribution is used, the linear response theory is recovered. Next, the particle-medium energy exchange is treated within a Fokker-Planck framework in order to obtain the nonequilibrium energy distribution; a nonlinear framework is used to account for the quantum-statistical correlations. Explicit formulas are obtained for homogeneous distributions at steady state. The rate of change of entropy is a simple generalization of the second law of thermodynamics. The positivity of the total entropy production stems from the positive definiteness of the diffusion tensors. Minimal entropy production is not necessarily achieved in the stationary state.

  5. Electromagnetic drift waves dispersion for arbitrarily collisional plasmas

    SciTech Connect

    Lee, Wonjae Krasheninnikov, Sergei I.; Angus, J. R.

    2015-07-15

    The impacts of the electromagnetic effects on resistive and collisionless drift waves are studied. A local linear analysis on an electromagnetic drift-kinetic equation with Bhatnagar-Gross-Krook-like collision operator demonstrates that the model is valid for describing linear growth rates of drift wave instabilities in a wide range of plasma parameters showing convergence to reference models for limiting cases. The wave-particle interactions drive collisionless drift-Alfvén wave instability in low collisionality and high beta plasma regime. The Landau resonance effects not only excite collisionless drift wave modes but also suppress high frequency electron inertia modes observed from an electromagnetic fluid model in collisionless and low beta regime. Considering ion temperature effects, it is found that the impact of finite Larmor radius effects significantly reduces the growth rate of the drift-Alfvén wave instability with synergistic effects of high beta stabilization and Landau resonance.

  6. Drift parameters optimization of a TPC polarimeter: a simulation study

    NASA Astrophysics Data System (ADS)

    Rakhee, K.; Radhakrishna, V.; Koushal, V.; Baishali, G.; Vinodkumar, A. M.

    2015-06-01

    Time Projection Chamber (TPC) based X-ray polarimeters using Gas Electron Multiplier (GEM) are currently being developed to make sensitive measurement of polarization in 2-10 keV energy range. The emission direction of the photoelectron ejected via photoelectric effect carries the information of the polarization of the incident X-ray photon. Performance of a gas based polarimeter is affected by the operating drift parameters such as gas pressure, drift field and drift-gap. We present simulation studies carried out in order to understand the effect of these operating parameters on the modulation factor of a TPC polarimeter. Models of Garfield are used to study photoelectron interaction in gas and drift of electron cloud towards GEM. Our study is aimed at achieving higher modulation factors by optimizing drift parameters. Study has shown that Ne/DME (50/50) at lower pressure and drift field can lead to desired performance of a TPC polarimeter.

  7. Conditional capture probability for Scaphirhynchus spp. in drifting trammel nets

    SciTech Connect

    Guy, Christopher S.; Oldenburg, Eric W.; Gerrity, Paul C.

    2009-06-01

    Pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon Scaphirhynchus platorynchus are commonly sampled using drifting-trammel nets in the Missouri River basin. Despite that drifting trammel nets have been used for decades to sample these species, little is known about the capture efficiency of this gear. We estimated conditional capture probability and gear efficiency for drifting trammel nets. In addition we examined several abiotic variables that were assumed to influence the success of capturing a pallid sturgeon or shovelnose sturgeon in a drifting trammel net. Conditional capture probability varied from 0.36 on the first attempt to 0.50 on the second attempt. Drifting trammel nets are relatively efficient and we suggest that they continue to be used to sample in large turbid rivers. The high variability associated with sampling pallid sturgeon and shovelnose sturgeon using drifting trammel nets is likely related to low abundance and patchy distributions. Thus, we suggest using more appropriate sampling designs for rare species.

  8. MODELING DRIFT ALONG THE HELIOSPHERIC WAVY NEUTRAL SHEET

    SciTech Connect

    Burger, R. A.

    2012-11-20

    Drift along the wavy heliospheric neutral sheet is believed to play an important role in cosmic-ray modulation and can explain the peaked versus flat intensity profiles during consecutive solar magnetic epochs. Modulation models are becoming more and more realistic and in order to determine the role of the wavy neutral sheet more accurately, we revisit a previous calculation for drift along it. While mathematically correct, we argue that the previous expression for neutral sheet drift, which follows naturally from the standard expression for gradient and curvature drift, must be adapted in order for the drift speed to be less than particle speed. We compare the effect of both the previous and the current more accurate version of neutral sheet drift on cosmic-ray modulation with results obtained by other methods.

  9. In-Drift Precipitates/Salts Model

    SciTech Connect

    P. Mariner

    2004-11-09

    This report documents the development and validation of the in-drift precipitates/salts (IDPS) model. The IDPS model is a geochemical model designed to predict the postclosure effects of evaporation and deliquescence on the chemical composition of water within the Engineered Barrier System (EBS) in support of the Total System Performance Assessment for the License Application (TSPA-LA). Application of the model in support of TSPA-LA is documented in ''Engineered Barrier System: Physical and Chemical Environment Model'' (BSC 2004 [DIRS 169860]). Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration (BSC 2004 [DIRS 171156]) is the technical work plan (TWP) for this report. It called for a revision of the previous version of the report (BSC 2004 [DIRS 167734]) to achieve greater transparency, readability, data traceability, and report integration. The intended use of the IDPS model is to estimate and tabulate, within an appropriate level of confidence, the effects of evaporation, deliquescence, and potential environmental conditions on the pH, ionic strength, and chemical compositions of water and minerals on the drip shield or other location within the drift during the postclosure period. Specifically, the intended use is as follows: (1) To estimate, within an appropriate level of confidence, the effects of evaporation and deliquescence on the presence and composition of water occurring within the repository during the postclosure period (i.e., effects on pH, ionic strength, deliquescence relative humidity, total concentrations of dissolved components in the system Na-K-H-Mg-Ca-Al-Cl-F-NO{sub 3}-SO{sub 4}-Br-CO{sub 3}-SiO{sub 2}-CO{sub 2}-O{sub 2}-H{sub 2}O, and concentrations of the following aqueous species that potentially affect acid neutralizing capacity: HCO{sub 3}{sup -}, CO{sub 3}{sup 2-}, OH{sup -}, H{sup +}, HSO{sub 4}{sup -}, Ca{sup 2+}, Mg{sup 2+}, CaHCO{sub 3}{sup +}, MgHCO{sub 3}{sup +}, HSiO{sub 3

  10. Primary and secondary pesticide drift profiles from a peach orchard.

    PubMed

    Zivan, Ohad; Bohbot-Raviv, Yardena; Dubowski, Yael

    2017-06-01

    Atmospheric drift is considered a major loss path of pesticide from target areas, but there is still a large gap of knowledge regarding this complex phenomenon. Pesticide drift may occur during application (Primary drift) and after it (Secondary drift). The present study focuses on primary and secondary drift from ground applications in peach orchard (tree height of 3 m), under Mediterranean climate. Detailed and prolonged vertical drift profiles at close proximity to orchard are presented, together with detailed measurements of key meteorological parameters. The effect of volatility on drift was also studied by simultaneously applying two pesticides that differ in their volatility. Drifting airborne pesticides were detected both during and after applications at sampling distances of 7 and 20 m away from orchard edge. Concentrations ranged between hundreds ng m(-3) to a few μg m(-3) and showed clear decrease with time and with upwind conditions. Almost no decline in concentrations with height was observed up to thrice canopy height (i.e., 10 m). These homogeneous profiles indicate strong mixing near orchard and are in line with the unstable atmospheric conditions that prevailed during measurements. While air concentrations during pesticide application were higher than after it, overall pesticide load drifted from the orchard during primary and secondary drift are comparable. To the best of our knowledge this is the first work to show such large vertical dispersion and long duration of secondary drift following ground application in orchards. The obtained information indicates that secondary drift should not be neglected in exposure and environmental impact estimations.

  11. The Ion Drift Meter for Dynamics Explorer-B

    NASA Technical Reports Server (NTRS)

    Heelis, R. A.; Hanson, W. B.; Lippincott, C. R.; Zuccaro, D. R.; Harmon, L. H.; Holt, B. J.; Doherty, J. E.; Power, R. A.

    1981-01-01

    The Ion Drift Meter on Dynamics Explorer-B measures two mutually perpendicular angles of arrival of thermal ions with respect to the sensor look direction. These measurements are used to derive two components of the ambient thermal ion drift velocity, which together with the third component from the Retarding Potential Analyzer instrument provide the total velocity. The Ion Drift Meter technique yields high temporal resolution measurements essential in the studies of the convection pattern and energy deposition in the ionosphere.

  12. Arctic Ocean sea ice drift origin derived from artificial radionuclides.

    PubMed

    Cámara-Mor, P; Masqué, P; Garcia-Orellana, J; Cochran, J K; Mas, J L; Chamizo, E; Hanfland, C

    2010-07-15

    Since the 1950s, nuclear weapon testing and releases from the nuclear industry have introduced anthropogenic radionuclides into the sea, and in many instances their ultimate fate are the bottom sediments. The Arctic Ocean is one of the most polluted in this respect, because, in addition to global fallout, it is impacted by regional fallout from nuclear weapon testing, and indirectly by releases from nuclear reprocessing facilities and nuclear accidents. Sea-ice formed in the shallow continental shelves incorporate sediments with variable concentrations of anthropogenic radionuclides that are transported through the Arctic Ocean and are finally released in the melting areas. In this work, we present the results of anthropogenic radionuclide analyses of sea-ice sediments (SIS) collected on five cruises from different Arctic regions and combine them with a database including prior measurements of these radionuclides in SIS. The distribution of (137)Cs and (239,240)Pu activities and the (240)Pu/(239)Pu atom ratio in SIS showed geographical differences, in agreement with the two main sea ice drift patterns derived from the mean field of sea-ice motion, the Transpolar Drift and Beaufort Gyre, with the Fram Strait as the main ablation area. A direct comparison of data measured in SIS samples against those reported for the potential source regions permits identification of the regions from which sea ice incorporates sediments. The (240)Pu/(239)Pu atom ratio in SIS may be used to discern the origin of sea ice from the Kara-Laptev Sea and the Alaskan shelf. However, if the (240)Pu/(239)Pu atom ratio is similar to global fallout, it does not provide a unique diagnostic indicator of the source area, and in such cases, the source of SIS can be constrained with a combination of the (137)Cs and (239,240)Pu activities. Therefore, these anthropogenic radionuclides can be used in many instances to determine the geographical source area of sea-ice.

  13. Drift studies--comparison of field and wind tunnel experiments.

    PubMed

    Stadler, R; Regenauer, W

    2005-01-01

    Drift at pesticide application leads to a pollution of non-target crops, non-target species and surface water. Spray drift is influenced by many factors like environmental conditions, vegetation, technical conditions, and physical properties of the tank mixes and influenced by Chemicals. Field experiments to characterise spray drift effects with the risk of permanent changing weather conditions can be supported by wind tunnel experiments. Wind tunnel experiments do not lead to the same soil deposition curves like field experiments, but the ratio of drift reduction potential is comparable.

  14. Drifts of auroral structures and magnetospheric electric fields

    SciTech Connect

    Nakamura, Rumi; Oguti, Takasi )

    1987-10-01

    Drifts of pulsating auroral patches and discrete auroral arc fragments are analyzed on the basis of all-sky TV observations of auroras. The drifts of auroral structures in this study correspond on a gross scale with other measurements of magnetospheric convection. The result strongly suggests that not only auroral patches but also arc fragments, when detached from the main body of the discrete aurora, drift owing to the magnetospheric electric fields. The measurement of the drifts of auroral structures could possibly provide us with a convenient and accurate method to estimate the magnetospheric electric fields.

  15. Modeling Exoplanetary Atmospheres using BART, TEA, and Drift-RHD; Theoretical studies and Observational Implications

    NASA Astrophysics Data System (ADS)

    Dobbs-Dixon, Ian

    numerous published papers, further work is needed to couple them self-consistently. Our theoretical studies focus on a number of objectives. We will start by incorporating our kinetic, non-equilibrium cloud model within BART, allowing us to obtain a consistent solution for cloud characteristics. We will further test simple parameterizations against the full solution to explore the reliability of simpler models. Utilizing Drift-RHD, we will explore the role of horizontal advection on cloud distribution, investigate the validity of 1D retrievals by comparing them to selfconsistently generated 3D models, and develop a retrieval framework for wavelengthdependent phase-curves. TEA will be enhanced with additional databases and the inclusion of condensates, providing realistic initial cloudy-model for retrievals. To explore the importance of equilibrium chemistry and exclude non-plausible chemical compositions (often the outcome of many retrieval approaches) we will relax the assumption of non-equilibrium chemistry by utilizing an analytical chemical equilibrium approach in BART. To address observations, our OBS suit for generating synthetic observations will be adapted to interface with our models, allowing us to both compare to existing observations and make predictions for future observations. With these tools, we are particularly well suited to understand discriminants between classes of models and identifying which particular set of observations could most readily distinguish cloud constituents and temperature features. The proposed research is directly relevant to the Planetary Science and Astrophysics goals through furthering our understanding of compositions, dynamics, energetics, and chemical behaviors of exoplanetary atmospheres. In addition, to maximize NASA's investment and encourage open access, we have and will continue to make all of our codes public and available to the community throughout the course of the research.

  16. Tabulated In-Drift Geometric and Thermal Properties Used In Drift-Scale Models for TSPA-SR

    SciTech Connect

    N.D. Francis

    2000-06-16

    The objective of this calculation is to provide in-drift physical properties required by the drift-scale models (both two- and three-dimensional) used in total system performance assessments (TSPA). The physical properties include waste package geometry, waste package thermal properties, emplacement drift geometry including backfill and invert geometry and properties (both thermal and hydrologic), drip shield geometry and thermal properties, all tabulated in a single source.

  17. Access Denied

    ERIC Educational Resources Information Center

    Villano, Matt

    2008-01-01

    Building access control (BAC)--a catchall phrase to describe the systems that control access to facilities across campus--has traditionally been handled with remarkably low-tech solutions: (1) manual locks; (2) electronic locks; and (3) ID cards with magnetic strips. Recent improvements have included smart cards and keyless solutions that make use…

  18. Open Access

    ERIC Educational Resources Information Center

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

  19. Drift effects on electromagnetic geodesic acoustic modes

    SciTech Connect

    Sgalla, R. J. F.

    2015-02-15

    A two fluid model with parallel viscosity is employed to derive the dispersion relation for electromagnetic geodesic acoustic modes (GAMs) in the presence of drift (diamagnetic) effects. Concerning the influence of the electron dynamics on the high frequency GAM, it is shown that the frequency of the electromagnetic GAM is independent of the equilibrium parallel current but, in contrast with purely electrostatic GAMs, significantly depends on the electron temperature gradient. The electromagnetic GAM may explain the discrepancy between the f ∼ 40 kHz oscillation observed in tokamak TCABR [Yu. K. Kuznetsov et al., Nucl. Fusion 52, 063044 (2012)] and the former prediction for the electrostatic GAM frequency. The radial wave length associated with this oscillation, estimated presently from this analytical model, is λ{sub r} ∼ 25 cm, i.e., an order of magnitude higher than the usual value for zonal flows (ZFs)

  20. Lower hybrid drift waves: space observations.

    PubMed

    Norgren, Cecilia; Vaivads, Andris; Khotyaintsev, Yuri V; André, Mats

    2012-08-03

    Lower hybrid drift waves (LHDWs) are commonly observed at plasma boundaries in space and laboratory, often having the strongest measured electric fields within these regions. We use data from two of the Cluster satellites (C3 and C4) located in Earth's magnetotail and separated by a distance of the order of the electron gyroscale. These conditions allow us, for the first time, to make cross-spacecraft correlations of the LHDWs and to determine the phase velocity and wavelength of the LHDWs. Our results are in good agreement with the theoretical prediction. We show that the electrostatic potential of LHDWs is linearly related to fluctuations in the magnetic field magnitude, which allows us to determine the velocity vector through the relation ∫δEdt·v = ϕ(δB)(∥). The electrostatic potential fluctuations correspond to ∼10% of the electron temperature, which suggests that the waves can strongly affect the electron dynamics.

  1. Drifting localized structures in doubly diffusive convection

    NASA Astrophysics Data System (ADS)

    Knobloch, Edgar; Lo Jacono, David; Bergeon, Alain

    2016-11-01

    We use numerical continuation to compute a multiplicity of spatially localized states in doubly diffusive convection in a vertical slot driven by imposed horizontal temperature and concentration differences. The calculations focus on the so-called opposing case, in which the resulting gradients are in balance. No-slip boundary conditions are used at the sides and periodic boundary conditions with large spatial period are used in the vertical direction. This system exhibits homoclinic snaking of stationary spatially localized structures with point symmetry. In this talk we demonstrate the existence, near threshold, of drifting pulses of spatially localized convection that appear when mixed concentration boundary conditions are used, and use homotopic continuation to identify similar states in the case of fixed concentration boundary conditions. We show that these states persist to large values of the Grasshof number and provide a detailed study of their properties.

  2. Drift:. a Dark Matter Detector with Directional Sensitivity

    NASA Astrophysics Data System (ADS)

    Morgan, B.; Snowden-Ifft, D. P.; Kirkpatrick, J.; Martoff, J.; Ayad, R.; Craig, W. W.

    2002-01-01

    The DRIFT detector is the first WIMP dark matter detector capable of measuring the directions of nuclear recoils. This article discusses the advantages of a directional detector, the first operational detector (DRIFT-I), and research into a new optical readout system.

  3. Variable-energy drift-tube linear accelerator

    DOEpatents

    Swenson, Donald A.; Boyd, Jr., Thomas J.; Potter, James M.; Stovall, James E.

    1984-01-01

    A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

  4. Variable-energy drift-tube linear accelerator

    DOEpatents

    Swenson, D.A.; Boyd, T.J. Jr.; Potter, J.M.; Stovall, J.E.

    A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

  5. VERIFYING THE PERFORMANCE OF PESTICIDE SPRAY DRIFT REDUCTION TECHNOLOGIES

    EPA Science Inventory

    Application of pesticide sprays usually results in formation of small spray droplets which can drift with air currents to nearby sensitive sites. A number of technologies offer the potential to reduce the amount of spray drift from pesticide applications. Acceptance and use of ...

  6. Comparison of ionospheric plasma drifts obtained by different techniques

    NASA Astrophysics Data System (ADS)

    Kouba, Daniel; Arikan, Feza; Arikan, Orhan; Toker, Cenk; Mosna, Zbysek; Gok, Gokhan; Rejfek, Lubos; Ari, Gizem

    2016-07-01

    Ionospheric observatory in Pruhonice (Czech Republic, 50N, 14.9E) provides regular ionospheric sounding using Digisonde DPS-4D. The paper is focused on F-region vertical drift data. Vertical component of the drift velocity vector can be estimated by several methods. Digisonde DPS-4D allows sounding in drift mode with direct output represented by drift velocity vector. The Digisonde located in Pruhonice provides direct drift measurement routinely once per 15 minutes. However, also other different techniques can be found in the literature, for example the indirect estimation based on the temporal evolution of measured ionospheric characteristics is often used for calculation of the vertical drift component. The vertical velocity is thus estimated according to the change of characteristics scaled from the classical quarter-hour ionograms. In present paper direct drift measurement is compared with technique based on measuring of the virtual height at fixed frequency from the F-layer trace on ionogram, technique based on variation of h`F and hmF. This comparison shows possibility of using different methods for calculating vertical drift velocity and their relationship to the direct measurement used by Digisonde. This study is supported by the Joint TUBITAK 114E092 and AS CR 14/001 projects.

  7. Hydrogeology of glacial drift, Mesabi Iron Range, northeastern Minnesota

    USGS Publications Warehouse

    Winter, Thomas C.

    1973-01-01

    Practical sustained yield of aquifers in glacial drift is estimated to be as much as 40 million gallons per day from known aquifers. Assuming that the ratio of area underlain by aquifer to total area is constant for the study area (about 20 percent where mapped in detail), as much as 80 million gallons per day could be developed from glacial-drift aquifers.

  8. Drift tube suspension for high intensity linear accelerators

    DOEpatents

    Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

    1980-03-11

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  9. Drift tube suspension for high intensity linear accelerators

    DOEpatents

    Liska, Donald J.; Schamaun, Roger G.; Clark, Donald C.; Potter, R. Christopher; Frank, Joseph A.

    1982-01-01

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  10. The influence of nozzle type, operating pressure, and tank-mixture components on droplet characteristics and the EPA's drift reduction rating

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introduction of drift reduction technology (DRT) guidelines by the U. S. Environmental Protection Agency (EPA) has established testing protocols for nozzles, agrochemicals, application parameters, and combinations thereof for applying agrochemicals by certified individuals in the United States....

  11. Bisexuality, Sexual Risk Taking, and HIV Prevalence Among Men Who Have Sex With Men Accessing Voluntary Counseling and Testing Services in Mumbai, India

    PubMed Central

    Kumta, Sameer; Lurie, Mark; Weitzen, Sherry; Jerajani, Hemangi; Gogate, Alka; Row-kavi, Ashok; Anand, Vivek; Makadon, Harvey; Mayer, Kenneth H.

    2010-01-01

    Objectives To describe sociodemographics, sexual risk behavior, and estimate HIV and sexually transmitted infection (STI) prevalence among men who have sex with men (MSM) in Mumbai, India. Methods Eight hundred thirty-one MSM attending voluntary counseling and testing (VCT) services at the Humsafar Trust, answered a behavioral questionnaire and consented for Venereal Disease Research Laboratory and HIV testing from January 2003 through December 2004. Multivariate logistic regression was performed for sociodemographics, sexual risk behavior, and STIs with HIV result as an outcome. Results HIV prevalence among MSM was 12.5%. MSM who were illiterate [adjusted odds ratio (AOR) 2.28; 95% confidence interval (CI): 1.08 to 4.84], married (AOR 2.70; 95% CI: 1,56 to 4.76), preferred male partners (AOR 4.68; 95% CI: 1.90 to 11.51), had partners of both genders (AOR 2.73; 95% CI: 1.03 to 7.23), presented with an STI (AOR 3.31; 95% CI: 1.96 to 5.61); or presented with a reactive venereal disease research laboratory test (AOR 4.92; 95% CI: 2.55 to 9.53) at their VCT visit were more likely to be HIV infected. Conclusions MSM accessing VCT services in Mumbai have a high risk of STI and HIV acquisition. Culturally appropriate interventions that focus on sexual risk behavior and promote condom use among MSM, particularly the bridge population of bisexual men, are needed to slow the urban Indian AIDS epidemic. PMID:19934765

  12. LIDAR as an alternative to passive collectors to measure pesticide spray drift

    NASA Astrophysics Data System (ADS)

    Gregorio, Eduard; Rosell-Polo, Joan R.; Sanz, Ricardo; Rocadenbosch, Francesc; Solanelles, Francesc; Garcerá, Cruz; Chueca, Patricia; Arnó, Jaume; del Moral, Ignacio; Masip, Joan; Camp, Ferran; Viana, Rafael; Escolà, Alexandre; Gràcia, Felip; Planas, Santiago; Moltó, Enrique

    2014-01-01

    Pesticide spray drift entails a series of risks and costs in terms of human, animal and environmental well-being. A proper understanding of this phenomenon is essential to minimise these risks. However, most conventional methods used in drift measurement are based on point collectors which are unable to obtain information concerning the temporal or spatial evolution of the pesticide cloud. Such methods are also costly, labour-intensive, and require a considerable amount of time. The aim of this paper is to propose a method to measure the spray drift based on lidar (LIght Detection And Ranging) and to prove that it can be an alternative to passive collectors. An analytical model is proposed to relate the measurements obtained through passive collectors and those obtained with lidar systems considering several spray application and meteorological parameters. The model was tested through an experimental campaign involving multiple ground spray tests. A lidar system and two types of passive collectors (nylon strings and water-sensitive paper) were used simultaneously to measure the drift. The results showed for each test a high coefficient of determination (R2 ≈ 0.90) between the lidar signal and the tracer mass captured by the nylon strings. This coefficient decreased (R2 = 0.77) when all tests were considered together. Lidar measurements were also used to study the evolution of the pesticide cloud with high range (1.5 m) and temporal resolution (1 s) and to estimate its velocity. Furthermore, a very satisfactory adjustment (R2 = 0.89) was observed between the tracer mass collected by the nylon lines and the coverage on water-sensitive paper sheets. These results are in accordance with the proposed analytical model and allow the conclusion that the application and meteorological parameters can be considered spatially invariant for a given test but are not invariant for different tests.

  13. Drifting Markov models with polynomial drift and applications to DNA sequences.

    PubMed

    Vergne, Nicolas

    2008-01-01

    In this article, we introduce the drifting Markov models (DMMs) which are inhomogeneous Markov models designed for modeling the heterogeneities of sequences (in our case DNA or protein sequences) in a more flexible way than homogeneous Markov chains or even hidden Markov models (HMMs). We focus here on the polynomial drift: the transition matrix varies in a polynomial way. To show the reliability of our models on DNA, we exhibit high similarities between the probability distributions of nucleotides obtained by our models and the frequencies of these nucleotides computed by using a sliding window. In a further step, these DMMs can be used as the states of an HMM: on each of its segments, the observed process can be modeled by a drifting Markov model. Search of rare words in DNA sequences remains possible with DMMs and according to the fits provided, DMMs turn out to be a powerful tool for this purpose. The software is available on request from the author. It will soon be integrated on seq++ library (http://stat.genopole.cnrs.fr/seqpp/).

  14. Ground-water resources in New Hampshire; stratified-drift aquifers

    USGS Publications Warehouse

    Medalie, Laura; Moore, R.B.

    1995-01-01

    Stratified-drift aquifers underlie about 14 percent of the land surface in New Hampshire and are an important source of ground water for commercial, industrial, domestic, and public-water supplies in the State. This report introduces terms and concepts relevant to ground-water resources, summarizes some of the important information derived from a statewide stratified-drift-aquifer investigation, and provides examples of how the findings are used . The purpose of this report is to provide an overview of the stratified-drift aquifer assessment program, thus making summary information accessible to a broad audience, including legislators, State and local officials, and the public. Different audiences will use the report in different ways . To accommodate the varied audiences, some data are summarized statewide, some are presented by major river basin, and some are provided by town. During data collection, care was taken to use consistent methods for each of the 13 study areas (fig. 1) so that results would be comparable throughout the State . If more specific or detailed information about a particular area of interest is needed, the reader is directed to one or more of the technical reports listed in the Selected References section of this report.

  15. An Implicit "Drift-Lorentz" Particle Mover for Plasma and Beam Simulations

    SciTech Connect

    Cohen, R H; Friedman, A; Grote, D P; Vay, J

    2008-03-07

    In order to efficiently perform particle simulations in systems with widely varying magnetization, we have developed a 'drift-Lorentz mover', which interpolates between full particle dynamics and drift kinetics in such a way as to preserve a physically correct gyroradius and particle drifts for both large and small ratios of the timestep to the cyclotron period. In order to extend applicability of the mover to systems with plasma frequency exceeding the cyclotron frequency - such as one may have with fully neutralized drift compression of a heavy ion beam - we have developed an implicit version of the mover. A first step in this direction, in which the polarization charge was added to the field solver, was described previously. Here we describe a fully implicit algorithm (which is analogous to the direct-implicit method for conventional particle-in-cell simulation), a stability analysis of it, its implementation in the WARP code, and several tests of the resultant code. The fully implemented version is electrostatic; we are beginning development of an electromagnetic version, and describe also the status of that effort.

  16. Virtual radar ice buoys - a method for measuring fine-scale sea ice drift

    NASA Astrophysics Data System (ADS)

    Karvonen, J.

    2016-01-01

    Here we present an algorithm for continuous ice drift estimation based on coastal and ship radar data. The ice drift is estimated for automatically selected ice targets in the images. These targets are here called virtual buoys (VBs) and are tracked based on an optical flow method. To maintain continuous ice drift tracking new VBs are added after a given number of VBs have been lost; i.e. they can not be tracked reliably any more. Here we also apply the algorithm to data of three test cases to demonstrate its capabilities and properties. Two of these cases use coastal radar data and one ship radar data. Ice drift velocity and direction information derived from the VB motion are computed and compared to the prevailing ice and weather conditions. Also a quantity measuring the local divergence or convergence is computed for some VBs to demonstrate the capability to estimate derived kinematic sea ice parameters from VB location time series. The results produced by the algorithm can be used as an input for estimation of the dynamic properties of sea the ice field, such as ice divergence or convergence, shear, vorticity, and total deformation.

  17. Groundwater quality variations in glacial drift and bedrock aquifers, Barry County, Michigan, U.S.A.

    NASA Astrophysics Data System (ADS)

    Kehew, Alan E.; Brewer, Margene K.

    1992-09-01

    Groundwater samples from 288 domestic wells in Barry County, Michigan, were analyzed for 33 inorganic chemical parameters. Variations in chemical composition were investigated by considering the possible effects of human impact, aquifer type (bedrock vs glacial drift), chemical evolution along groundwater flow paths, and glacial landform type (moraine vs outwash). Approximately 25 percent of the glacial drift wells were classified as degraded by human impact and were excluded from further analysis of chemical variation. Two-sample tests comparing individual concentrations from drift and bedrock aquifers suggest that groundwater in the Marshall Sandstone aquifer is derived from local recharge through the glacial drift. This conclusion is supported by generalized groundwater flow patterns recognized for the two aquifers. Concentrations in both aquifers were examined in relation to generalized flow paths derived from water level data and also by classification of wells as recharge, transition, and discharge. No spatial concentration trends in major ions were detected, although iron concentrations do appear to increase from recharge to discharge areas. Declining redox potential along groundwater flow paths may explain this trend. The possible influence of glacial landform type was investigated by comparing concentrations of wells in moraines with those in outwash deposits. Wells in moraines have significantly higher concentrations of most parameters, perhaps due to higher content of finer, more chemically reactive sediment grains.

  18. Spatiotemporal mode structure of nonlinearly coupled drift wave modes

    SciTech Connect

    Brandt, Christian; Grulke, Olaf; Klinger, Thomas; Negrete, Jose Jr.; Bousselin, Guillaume; Brochard, Frederic; Bonhomme, Gerard; Oldenbuerger, Stella

    2011-11-15

    This paper presents full cross-section measurements of drift waves in the linear magnetized plasma of the Mirabelle device. Drift wave modes are studied in regimes of weakly developed turbulence. The drift wave modes develop azimuthal space-time structures of plasma density, plasma potential, and visible light fluctuations. A fast camera diagnostic is used to record visible light fluctuations of the plasma column in an azimuthal cross section with a temporal resolution of 10 {mu}s corresponding approximately to 10% of the typical drift wave period. Mode coupling and drift wave dispersion are studied by spatiotemporal Fourier decomposition of the camera frames. The observed coupling between modes is compared to calculations of nonlinearly coupled oscillators described by the Kuramoto model.

  19. Drift compression and final focus options for heavy ionfusion

    SciTech Connect

    Qin, Hong; Davidson, Ronald C.; Barnard, John J.; Lee, Edward P.

    2005-01-18

    A drift compression and final focus lattice for heavy ion beams should focus the entire beam pulse onto the same focal spot on the target. The authors show that this requirement implies that the drift compression design needs to satisfy a self-similar symmetry condition. For un-neutralized beams, the Lie symmetry group analysis is applied to the warm-fluid model to systematically derive the self-similar drift compression solutions. For neutralized beams, the 1D Vlasov equation is solved explicitly and families of self-similar drift compression solutions are constructed. To compensate for the deviation from the self-similar symmetry condition due to the transverse emittance, four time-dependent magnets are introduced in the upstream of the drift compression such that the entire beam pulse can be focused onto the same focal spot.

  20. Drift kinetic theory of neoclassical tearing mode physics

    NASA Astrophysics Data System (ADS)

    Wilson, Howard; Connor, Jack; Hill, Peter; Imada, Koki

    2016-10-01

    Orbit averaged equations for the particle responses to a small magnetic island are derived, expanding the drift kinetic equation in the ratio of island width to tokamak plasma minor radius, assumed small. Analytic solutions demonstrate that the particles follow drift orbits which have the same geometry as the magnetic island flux surfaces, but are shifted radially by an amount that is proportional to the poloidal Larmor radius (in opposite directions for opposite signs of parallel velocity). The distribution function is flattened across these drift island structures, rather than across the magnetic island. Numerical solutions of our equations confirm the existence of the drift orbits. We employ a model momentum-conserving collision operator to evaluate the consequences for neoclassical tearing mode threshold physics, implementing numerical solutions to our orbit-averaged drift kinetic equations in a ``Modified Rutherford Equation''. Supported by the EPSRC, Grant Number EP/N009363/1.

  1. Prediction of ion drift effects on spacecraft floating potentials

    NASA Technical Reports Server (NTRS)

    Chang, J. S.; Prokopenko, S. M. L.; Godard, R.; Laframboise, J. G.

    1979-01-01

    The plasma environment of high altitude spacecraft was observed to involve ion drift velocities which sometimes become comparable to ion mean thermal speeds. Such drifts may cause an electrically isolated spacecraft surface to float at a substantially increased negative potential if it is simultaneously shaded and downstream relative to the drift direction. The results showed that: (1) the ion speed ratio at which drift effects become important (i.e. change the floating potential by at least 10 percent) can be as low as 0.1, and may be decreased if the ambient electrons are non-Maxwellian; (2) the effects of ion speed ratio increase with increasing ion-to-electron temperature ratio; and (3) negative floating potentials for drifting Maxwellian ion velocity distributions with speed ratio unity are typically about twice as large as the corresponding potentials for nondrifting conditions.

  2. Electron drift in a large scale solid xenon

    SciTech Connect

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    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. Furthermore, 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.

  3. Ulnar drift in rheumatoid arthritis: a review of biomechanical etiology.

    PubMed

    Morco, Stephanie; Bowden, Anton

    2015-02-26

    The objective of this article is to summarize current understanding of biomechanical factors that cause ulnar drift in the hands of patients with rheumatoid arthritis. This was done through literature review of published articles on the mechanical etiology of ulnar drift. There are several theories regarding the cause of ulnar drift, however conclusive evidence is still lacking. Current mechanical factors that are postulated to play a role include: failure of the collateral ligaments, intra-articular pressure changes, degenerative changes in the carpal and metacarpal anatomy, muscle hypoxia induced changes in wrist tension, and exacerbating activities of daily living. Although current theories regarding ulnar drift almost universally include an at least partially mechanical rationale, the causes may be multifactorial. Significantly more research is needed to elucidate the relative importance of mechanical factors leading to significant ulnar drift concurrent with advanced rheumatoid arthritis.

  4. Electron drift in a large scale solid xenon

    DOE PAGES

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    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. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

  5. Drift of suspended ferromagnetic particles due to the Magnus effect

    NASA Astrophysics Data System (ADS)

    Denisov, S. I.; Pedchenko, B. O.

    2017-01-01

    A minimal system of equations is introduced and applied to study the drift motion of ferromagnetic particles suspended in a viscous fluid and subjected to a time-periodic driving force and a nonuniformly rotating magnetic field. It is demonstrated that the synchronized translational and rotational oscillations of these particles are accompanied by their drift in a preferred direction, which occurs under the action of the Magnus force. We calculate both analytically and numerically the drift velocity of particles characterized by single-domain cores and nonmagnetic shells and show that there are two types of drift, unidirectional and bidirectional, which can be realized in suspensions composed of particles with different core-shell ratios. The possibility of using the phenomenon of bidirectional drift for the separation of core-shell particles in suspensions is also discussed.

  6. Effects of hydro- and thermopeaking on benthic macroinvertebrate drift.

    PubMed

    Schülting, Lisa; Feld, Christian K; Graf, Wolfram

    2016-12-15

    The operation of storage hydropower plants is commonly linked to frequent fluctuations in discharge and water level (hydropeaking) of downstream river stretches and is often accompanied by cooling or warming of the water body downstream (cold or warm thermopeaking, respectively). The objective of this study is to assess the single and combined effects of hydropeaking and cold thermopeaking on the drift of selected aquatic macroinvertebrates in experimental flumes. The study specifically aims to (1) investigate the macroinvertebrate drift induced by hydropeaking, (2) identify taxon-specific drift patterns following combined hydropeaking and cold thermopeaking and (3) quantify diurnal drift differences under both impact types. Overall, hydropeaking induced significantly higher drift rates of most macroinvertebrate taxa. Combined hydropeaking and cold thermopeaking, however, revealed reduced total drift rates, however with strong taxon-specific response patterns. Hydropeaking during night led to significantly higher drift rates than during daytime, while in combination with thermopeaking the same trend was observable, although insignificant. Taxon-specific analysis revealed lower drift rates following hydropeaking for rheophilic and interstitial taxa (e.g. Leuctra sp., Hydropsyche sp.), whereas many limnophilic taxa adapted to low current showed markedly increased drift (e.g. Lepidostoma hirtum and Leptoceridae). In line with previous studies, our results confirm a significant loss of limnophilic macroinvertebrate taxa following hydraulic stress. The mitigating effect of cold thermopeaking might be explained by behavioural patterns, but requires further investigation to clarify if macroinvertebrates actively avoid drift and intrude into the interstitial, when cold water is discharged. Our results imply that river restoration projects must address the hydrological regime and, if necessary need to include suitable management schemes for hydropower plants. Besides

  7. Non-twist map bifurcation of drift-lines and drift-island formation in saturated 3D MHD equilibria

    NASA Astrophysics Data System (ADS)

    Pfefferle, David; Cooper, Wilfred A.; Graves, Jonathan P.

    2015-11-01

    Based on non-canonical perturbation theory, guiding-centre drift equations are identified as perturbed magnetic field-line equations. The topology of passing-particle orbits, called drift-lines, is completely determined by the magnetic configuration. In axisymmetric tokamak fields, drift-lines lie on shifted flux-surfaces, called drift-surfaces. Field-lines and drift-lines are subject to island structures at rational surfaces only when a non-axisymmetric component is added. The picture is different in the case of 3D saturated MHD equilibrium like the helical core associated with a non-resonant internal kink mode. In assuming nested flux-surfaces, these bifurcated states, expected for a reversed q-profile with qmin close yet above unity and conveniently obtained in VMEC, feature integrable field-lines. The helical drift-lines however become resonant with the axisymmetric component in the region of qmin and spontaneously generate drift-islands. Due to the locally reversed sheared q-profile, the drift-island structure follows the bifurcation/reconnection mechanism of non-twist maps. This result provides a theoretical interpretation of NBI fast ion helical hot-spots in Long-Lived Modes as well as snake-like impurity density accumulation in internal MHD activity.

  8. Equal Access.

    ERIC Educational Resources Information Center

    De Patta, Joe

    2003-01-01

    Presents an interview with Stephen McCarthy, co-partner and president of Equal Access ADA Consulting Architects of San Diego, California, about designing schools to naturally integrate compliance with the Americans with Disabilities Act (ADA). (EV)

  9. A minority research and education information service: Design, develop, pilot test, and implement on-line access for historically black colleges and universities and government agencies

    SciTech Connect

    Rodman, J.A.

    1992-01-01

    This Annual Status Report describes the design, development and implementation of the Minority On-Line Information Service (MOLIS) project by Federal Information Exchange, Inc. for the period of April 1, 1991 to March 31, 1992. Summary information detailing developments prior to this reporting period will also be included to establish a comprehensive perspective of the project. The goal of the MOLIS project, was to develop, design, pilot test on-line access to current information on minority colleges and universities and federal minority opportunities. Federal Information Exchange, Inc. (FIE), a diversified information services company recognized by researchers and educators as a leader in the field of information delivery services, was awarded a 5 year small business research grant to develop and implement MOLIS. Since April 29, 1991, the inauguration of its on-line service, MOLIS has provided current information on 138 Black and Hispanic colleges and universities -- including faculty and student profiles, financial data, research centers and equipment information, pre-college and education programs, emerging capabilities, enrollment data, administrative personnel data, and current events -- as well as minority opportunities from 8 participating federal agencies.

  10. Ultracold plasmas and guiding center drift atoms

    NASA Astrophysics Data System (ADS)

    Kuzmin, Stanislav Gennadyevich

    This thesis discusses theory questions suggested by recent experiments with ultracold plasmas. In one class of experiments, ultracold plasmas are produced by abruptly photoionizing small clouds of laser cooled atoms, adjusting the photon energy to barely exceed the ionization energy of the cooled atoms. The thesis presents molecular dynamics simulation for the early time evolution of such plasmas. Contrary to earlier speculation, no evidence of strong electron-electron correlations is observed in the simulations even if the initial value of the coupling parameter (Gammae = e2/akTe) is much larger than unity. As electron-electron correlations begin to develop, the correlation energy is released to heat the electrons, raising the electron temperature to the point where Gammae ˜ 1 and limiting further development of correlation. Further heating of the electrons occurs as a by-product of three-body recombination. When a model of laser cooling is added to the simulation, the formation of strong ion-ion correlation is observed. Contrary to earlier suggestion, the rate of three-body recombination is observed to be in reasonable agreement with the traditional formula, R = 3.9 x 10-9 sec-1[ n (cm-3)]2 [Te(° K)]-9/2, but care must be taken to use the correct temporally evolving temperature, Te. Also, the thesis describes the novel dynamics of "guiding center drift atoms". The weakly bound and strongly magnetized antihydrogen atoms recently produced in ultracold plasmas at CERN are examples of such atoms. The atoms are quasi-classical, and the dynamics of the positron is well described by guiding center drift theory. Because of a frequency ordering, the dynamics is integrable, and the thesis characterizes the possible motions of the weakly bound positron-antiproton pair as a function of constants of the motion. Quantum numbers are assigned using the Bohr-Sommerfeld prescription. The thesis also discusses the center of mass motion of the atoms in an electric and magnetic

  11. Direct and indirect drift assessment means. Part 2: wind tunnel experiments.

    PubMed

    Nuyttens, D; De Schampheleire, M; Baetens, K; Sonck, B

    2008-01-01

    Wind tunnel measurements, performed in Silsoe Research Institute (SRI), were used to measure airborne and fallout spray volumes under directly comparable and repeatable conditions for single and static nozzles. Based on these measurements, drift potential reduction percentages (DPRP), expressing the percentage reduction of the drift potential compared with the reference spraying, were calculated following three approaches. The first approach was based on the calculation of the first moment of the airborne spray profile (DPRPv1). In the second and third approach, the surface under the measured airborne (DPRPv2) and fallout (DPRP(H)) deposit curve were used. These DPRP values express the percentage reduction of the drift potential compared with the reference spraying. Ten different spray nozzles were tested. The results showed the expected fallout profiles with the highest deposits closest to the nozzle and a systematic decrease with distance from the nozzle. For the airborne deposit profiles, the highest deposits were found at the Lowest collectors with an important systematic decrease with increasing heights. For the same nozzle size and spray pressure, DPRP values are generally higher for the air inclusion nozzles followed by the low-drift nozzles and the standard flat fan nozzles and the effect of nozzle type is most important for smaller nozzle sizes. In general, the bigger the ISO nozzle size, the higher the DPRP values. Comparing results from the three different approaches namely, DPRPv1, DPRPv2 and DPRP(H), some interesting conclusions can be drawn. For the standard flat fan nozzles, DPRPv1, values were the highest followed by DPRPv2 and DPRP(H) while for the low-drift nozzles opposite results were found. For the air inclusion nozzles, there was a relatively good agreement between DPRPv1, DPRPv1 and DPRP(H) values. All of this is important in the interpretation of wind tunnel data for different nozzle types and sampling methodologies.

  12. Halftone independent methods for color drift correction

    NASA Astrophysics Data System (ADS)

    Monga, Vishal; Wang, Shen-ge; Bala, Raja

    2007-01-01

    Color printer calibration is the process of deriving correction functions for device CMYK signals, so that the device can be maintained with a fixed known characteristic color response. Since the colorimetric response of the printer can be a strong function of the halftone, the calibration process must be repeated for every halftone supported by the printer. The effort involved in the calibration process thus increases linearly with the number of halftoning methods. In the past few years, it has become common for high-end digital color printers to be equipped with a large number of halftones thus making the calibration process onerous . We propose a halftone independent method for correcting color (CMY/CMYK) printer drift. Our corrections are derived by measuring a small number of halftone independent fundamental binary patterns based on the 2×2 binary printer model by Wang et. al. Hence, the required measurements do not increase as more halftoning methods are added. The key novelty in our work is in identifying an invariant halftone correction factor (HCF) that exploits the knowledge of the relationship between the true printer response and the 2×2 predicted response for a given halftoning scheme. We evaluate our scheme both quantitatively and qualitatively against the printer color correction transform derived with the printer in its "default state". Results indicate that the proposed method is very successful in calibrating a printer across a wide variety of halftones.

  13. Evolutionary Drift Models for Moving Target Defense

    SciTech Connect

    Oehmen, Christopher S.; Peterson, Elena S.; Teuton, Jeremy R.

    2012-10-31

    One of the biggest challenges faced by cyber defenders is that attacks evolve more rapidly than our ability to recognize them. We propose a moving target defense concept in which the means of detection is set in motion. This is done by moving away from static signature-based detection and instead adopting biological modeling techniques that describe families of related sequences. We present here one example for how to apply evolutionary models to cyber sequences, and demonstrate the feasibility of this technique on analysis of a complex, evolving software project. Specifically, we applied sequence-based and profile-based evolutionary models and report the ability of these models to recognize highly volatile code regions. We found that different drift models reliably identify different types of evolutionarily related code regions. The impact is that these (and possibly other) evolutionary models could be used in a moving target defense in which the "signature" being used to detect sequence-based behaviors is not a fixed signature but one that can recognize new variants of a known family based on multiple evolutionary models.

  14. Polarization of drifting pairs at decameter waves

    NASA Astrophysics Data System (ADS)

    Brazhenko, A. I.; Melnik, V. N.; Konovalenko, A. A.; Abranin, E. P.; Dorovskyy, V. V.; Vashchishin, R. V.; Frantsuzenko, A. V.; Rucker, H. O.; Lecacheux, A.

    2006-08-01

    The results of polarization researches of drifting pairs (DP) observed during Type III bursts storm in July[S:,:S][Author ID2: at Fri Jul 14 10:33:00 2006 ] 11-21, 2002 with radio telescope URAN-2 are presented. The array of the radio telescope consists of 512 broadband cross dipoles, that enables to receive signals of two polarizations, has the area about of 28000 m^2 and works in 9-30 MHz range. Circular polarization measurements were made at frequency 24.75 MHz in frequency band 10 μHz with time resolution 10 ms. Some hundreds bursts, both forward and reverse DPs, which have been registered with radio telescope UTR-2 in the frequency range 18-32 μHz, were analyzed. For the first time we find that DP polarizations strongly depend on the location of the active area associated with these bursts. When an active area is near to the central meridian, polarizations of both DP components have the same signs and their values are up to 30%. In other days in most cases polarizations of both components have opposite signs and only for some bursts polarization reaches 10%. In all cases both DP components have comparable polarization degrees.

  15. Light-induced drift of Na atoms

    NASA Astrophysics Data System (ADS)

    Werij, H. G. C.; Woerdman, J. P.

    1988-10-01

    Light can induce a flux of optically absorbing particles immersed in a buffer gas, when these particles have a different mobility in the ground and excited state. This paper presents a study of light-induced drift (LID) of Na atoms in noble gases, which can be regarded as the “canonical” system for experiments in this field. We have experimentally studied the LID effect in the optically thin and the optically thick regimes. Parameters which have been varied are laser frequency, laser intensity, buffer gas pressure and buffer gas species. This work gives the first critical comparison of LID experiments with realistic theory in which the multilevel complications of the Na atom have been incorporated. In the optically thick case (“optical piston”) one can distinguish the open cell and the closed cell regimes. Effects of adsorption and desorption of Na atoms at the surface of the cell wall have been incorporated into the theory. The experimental data are in excellent agreement with the results of a four-level rate-equation model for LID which incorporates the fine and hyperfine structure of the level scheme of the Na absorbers.

  16. Adaptive Online Sequential ELM for Concept Drift Tackling

    PubMed Central

    Basaruddin, Chan

    2016-01-01

    A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM) and Constructive Enhancement OS-ELM (CEOS-ELM) by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM). It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER) and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition. PMID:27594879

  17. Hydrodynamic transport of drifting macroalgae through a tidal cut

    NASA Astrophysics Data System (ADS)

    Biber, Patrick D.

    2007-09-01

    Drifting macroalgae are unattached seaweeds that are commonly found in many South Florida and Gulf of Mexico shallow-water seagrass habitats. They are primarily comprised of species of red algae (Rhodophyta) and some brown algae (Phaeophyta). Because of the unattached nature of these species, drift algae have the ability to be moved around the landscape primarily by tidal, as well as wind-driven and alongshore currents. Numerous invertebrates and some fish species are typically found associated with drift algal clumps and aggregations. Transport of drift algae is an important dispersal mechanism for both the plants and their associated fauna. Dispersal distances have been studied in numerous locations over a range of spatial scales. However, little is known about quantities of algal material that are involved. In this study I report on composition and biomass of drifting algae that are transported through a tidal inlet in Biscayne Bay, Florida. Sargassum (a brown alga) and about 12 genera of red algae were found in three seasonal collections (Aug., Dec., May). Total biomass collected varied among seasons, with larger average amounts of drift algae collected in May than the other two months sampled. From this data, I calculate the approximate quantities of drift algae that are potentially moving in, or out of, Biscayne Bay, about a half to one ton of biomass per day.

  18. Drift-Scale Coupled Processes (DST and TH Seepage) Models

    SciTech Connect

    J. Birkholzer; S. Mukhopadhyay

    2004-09-29

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  19. DRIFT-SCALE COUPLED PROCESSES (DST AND TH SEEPAGE) MODELS

    SciTech Connect

    J.T. Birkholzer; S. Mukhopadhyay

    2005-01-13

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  20. Distribution of drifting seaweeds in eastern East China Sea

    NASA Astrophysics Data System (ADS)

    Komatsu, Teruhisa; Tatsukawa, Kenichi; Filippi, Jean B.; Sagawa, Tatsuyuki; Matsunaga, Daisuke; Mikami, Atsuko; Ishida, Kenichi; Ajisaka, Tetsuro; Tanaka, Katsuhiko; Aoki, Masakazu; Wang, Wei-Ding; Liu, Hui-Fei; Zhang, Shou-Du; Zhou, Min-Dong; Sugimoto, Takashige

    2007-09-01

    In offshore waters with relatively low primary production, drifting seaweeds composed of Sargassum species form an identical ecosystem such as an oasis in desert. Commercially important pelagic fishes such as jack mackerel ( Trachurus japonicus) and yellow tail ( Seriola quinqueradiata) spawn in East China Sea pass their juvenile period accompanying drifting seaweeds. Therefore drifting seaweeds are very important not only in offshore ecosystem but also fishery resources. However the distribution of drifting seaweeds in East China Sea has scarcely known. Then we conducted two research cruises of R/V Hakuho-Maru in May 2002 and in March 2004. During the cruises, drifting seaweeds were visually observed from the bridge and sampled with a towing net. The observation revealed that the drifting seaweeds were distributed along the front between the Kuroshio Current and coastal waters and mainly composed of one seaweed species, Sargassum horneri (Turner) C. Agardh from spring to early summer. There are no reports on geographical distribution of this species in the coasts south of southern Kyushu Island in Japan. Kuroshio Current flows northeastward there. Buoys with GPS attached to drifting seaweeds released off Zhejiang Province, China, in March 2005 to track their transport. Their positions monitored by ORBCOM satellite showed that they were transported to the area in East China Sea, where the drifting seaweeds were observed during the cruises, in 2 months. These facts suggest that S. horneri detached from Chinese coast in March or months earlier than March could be transported to fringe area of continental shelf and waters influenced by Kuroshio Current from March to May. Therefore the Sargassum forests, especially S. horneri, along the Chinese coast play a very important role in the ecosystem of the East China Sea as a source of drifting seaweeds.

  1. Drift correction of the dissolved signal in single particle ICPMS.

    PubMed

    Cornelis, Geert; Rauch, Sebastien

    2016-07-01

    A method is presented where drift, the random fluctuation of the signal intensity, is compensated for based on the estimation of the drift function by a moving average. It was shown using single particle ICPMS (spICPMS) measurements of 10 and 60 nm Au NPs that drift reduces accuracy of spICPMS analysis at the calibration stage and during calculations of the particle size distribution (PSD), but that the present method can again correct the average signal intensity as well as the signal distribution of particle-containing samples skewed by drift. Moreover, deconvolution, a method that models signal distributions of dissolved signals, fails in some cases when using standards and samples affected by drift, but the present method was shown to improve accuracy again. Relatively high particle signals have to be removed prior to drift correction in this procedure, which was done using a 3 × sigma method, and the signals are treated separately and added again. The method can also correct for flicker noise that increases when signal intensity is increased because of drift. The accuracy was improved in many cases when flicker correction was used, but when accurate results were obtained despite drift, the correction procedures did not reduce accuracy. The procedure may be useful to extract results from experimental runs that would otherwise have to be run again. Graphical Abstract A method is presented where a spICP-MS signal affected by drift (left) is corrected (right) by adjusting the local (moving) averages (green) and standard deviations (purple) to the respective values at a reference time (red). In combination with removing particle events (blue) in the case of calibration standards, this method is shown to obtain particle size distributions where that would otherwise be impossible, even when the deconvolution method is used to discriminate dissolved and particle signals.

  2. Drift of Phase Fluctuations in the ABC Model

    NASA Astrophysics Data System (ADS)

    Bertini, Lorenzo; Buttà, Paolo

    2013-07-01

    In a recent work, Bodineau and Derrida analyzed the phase fluctuations in the ABC model. In particular, they computed the asymptotic variance and, on the basis of numerical simulations, they conjectured the presence of a drift, which they guessed to be an antisymmetric function of the three densities. By assuming the validity of the fluctuating hydrodynamic approximation, we prove the presence of such a drift, providing an analytical expression for it. This expression is then shown to be an antisymmetric function of the three densities. The antisymmetry of the drift can also be inferred from a symmetry property of the underlying microscopic dynamics.

  3. General ignition requirements in TMR's with drift pumping

    SciTech Connect

    Logan, B.G.

    1983-01-01

    Drift pumping of collisionally trapped DT ions and thermal alpha ash in the transitions and thermal barriers of TMR plugs can be shown by simple models to dominate the central cell energy losses, requiring in fact more radial ion loss by drift pumping than axial ion loss through the potential plugs, and setting a minimum central cell length for ignition. Induced electron transport due to drift pumping is shown to be small, so grids are not needed on the direct converter to separate ion and electron currents.

  4. On the drift magnetosonic waves in anisotropic low beta plasmas

    SciTech Connect

    Naim, Hafsa; Bashir, M. F.; Murtaza, G.

    2014-10-15

    A generalized dispersion relation of obliquely propagating drift magnetosonic waves is derived by using the gyrokinetic theory for anisotropic low beta plasmas. The stability analysis applicable to a wide range of plasma parameters is performed to understand the stabilization mechanism of the drift magnetosonic instability and the estimation of the growth rate is also presented. It is noted that the growth rate of the drift instability enhances for small anisotropy (A{sub e,i} = T{sub ⊥e,i}/T{sub ∥e,i} < 1) whereas it is suppressed for large anisotropy (A{sub e,i} > 1)

  5. Zonal drifts of irregularities imparted by meridional winds.

    NASA Technical Reports Server (NTRS)

    Waldman, H.; Da Rosa, A. V.

    1973-01-01

    In a uniform ionosphere, meridional winds cause only meridional motions of irregularities. It is shown, however, that, if F-region irregularities are considered in a real ionosphere in which there is a highly conductive E-layer, zonal motions occur. During the day a substantial westward drift takes place, while at night the drift is eastward but smaller, owing to the much smaller E-layer conductivity. Thus, the effect of meridional winds is to impart a net westward drift to small irregularities in the ionization, provided such irregularities persist long enough.

  6. Approximation of the characteristics of ion drift in parent gas

    NASA Astrophysics Data System (ADS)

    Golyatina, R. I.; Maiorov, S. A.

    2017-01-01

    The drift velocities of noble-gas and mercury ions in a constant homogeneous electric field are calculated using Monte Carlo simulations. The ion mobility is analyzed as a function of the field strength and gas temperature. The fitting parameters for calculating the drift velocity by the Frost formula at gas temperatures of 4.2, 77, 300, 1000, and 2000 K are obtained. A general approximate formula for the drift velocity as a function of the reduced field and gas temperature is derived.

  7. The Development of Drift Wave Turbulence in Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    McMurtrie, L.; Drake, J. F.; Swisdak, M. M.

    2013-12-01

    An important feature in collisionless magnetic reconnection is the development of sharp discontinuities along the separatrices bounding the Alfvenic outflow. The typical scale length of these features is ρs (the Larmor radius based on the sound speed) for guide field reconnection. Temperature gradients in the inflowing plasma (as might be found in the magnetopause) can lead to instabilities at these separatrices, specifically drift wave turbulence. We present standalone 2D and 3D PIC simulations of drift wave turbulence to investigate scaling properties and growth rates. Further investigations of the relative importance of drift wave turbulence in the development of reconnection will also be considered.

  8. Two-stream instability with time-dependent drift velocity

    DOE PAGES

    Qin, Hong; Davidson, Ronald C.

    2014-06-26

    The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. The stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.

  9. THREE-DIMENSIONAL WAVY HELIOSPHERIC CURRENT SHEET DRIFTS

    SciTech Connect

    Pei, C.; Bieber, J. W.; Clem, J.; Burger, R. A.

    2012-01-10

    We present an analytic method to determine the directions of the three-dimensional (3D) heliospheric current sheet (HCS) drift for any tilt angle based on Parker's heliospheric magnetic field and compare it with published two-dimensional and quasi-3D methods. We also present a new approach to determine the magnitude of the 3D HCS drift numerically. Implications of these new methods for the solar modulation of Galactic cosmic rays are considered and compared with results from prior methods reported in the literature. Our results support the concept that HCS drift plays an important role in the solar modulation of cosmic rays.

  10. Drift-free position estimation for periodic movements using inertial units.

    PubMed

    Millor, Nora; Lecumberri, Pablo; Gomez, Marisol; Martinez-Ramirez, Alicia; Izquierdo, Mikel

    2014-07-01

    Latest advances in microelectromechanical systems have made inertial units (IUs) a powerful tool for human motion analysis. However, difficulties in handling their output signals must be overcome. The purpose of this study was to develop the novel "PB-algorithm" based on polynomial data fitting, splines interpolation, and the wavelet transform, one after the other, to cancel drift disturbances in position estimation for periodic movements. High-accuracy position measurements from an optical system (Vicon Nexus 1.0) were used to validate the proposed method and comparison with another drift-correction algorithm was provided. Results indicate the accuracy with respect to the Vicon's reference signal (euclidean error lower than 54.62 × 10(-3) m and correlation coefficient higher than 0.968). A reduction of the root-mean-square error of 68.74% was obtained when the proposed two-step method was compared with a modified-band limited Fourier linear combiner. All methods were applied to data from the 30-s chair stand test, which is one of the most used clinical tests dealing with lower body strength assessment, falls prediction, and gait disorders in older adults. The relevance of this study is that after cancelling drift disturbances, and obtaining an accurate Z-position estimation, it is possible to evaluate the sit-to-stand and stand-to-sit transitions from the whole test.

  11. Sheath effects on DEMETER ion drift measurements

    NASA Astrophysics Data System (ADS)

    Marchand, Richard; Knutson, Nelson; Berthelier, Jean-Jacques

    2010-08-01

    The "Instrument d'Analyse du Plasma" on DEMETER includes an ion drift meter used to measure the direction of the incoming ram plasma ( Berthelier et al., 2006a, b ). Given the velocity of the satellite, and expected flow velocities of plasma along DEMETER's orbit, it is estimated that at mid latitudes, the direction of incident plasma as measured by IAP should be within approximately 2° of the ram direction. Yet, significantly larger angular deviations are measured routinely. An important assumption made in the interpretation of onboard instruments, such as IAP, is that neither the spacecraft nor the instrument significantly perturb the plasma that is being measured. In view of the large observed angular deviations, this paper examines the possible effect of the electrostatic sheath surrounding IAP. This is done with the 3D PIC simulation code PTetra. The model uses a full 3D particle in cell code with unstructured tetrahedral mesh capable of accurately representing the satellite geometry. The mesh is also adaptive so as to provide a fine spatial resolution in the vicinity of the particle sensor where it is needed, and a coarse resolution in regions where plasma parameters vary over a longer scale length. Calculation results show that while particle deflection associated with the electrostatic sheath near IAP can account for appreciable angular deflections for representative ionospheric plasmas, they are typically smaller than the ones observed. Additionally, the model is unable to reproduce the latitudinal dependence of the observed large deflection angles. It is concluded that sheath effects may cause appreciable distortions on the IAP type of ion flow meter instruments, and on other particle sensors in general. The larger observed deviations and their latitudinal dependence, however, must be attributable to other physical processes not accounted for in the model.

  12. VLBI measurement of the secular aberration drift

    NASA Astrophysics Data System (ADS)

    Titov, O.; Lambert, S. B.; Gontier, A.-M.

    2011-05-01

    Aims: While analyzing decades of very long baseline interferometry (VLBI) data, we detected the secular aberration drift of the extragalatic radio source proper motions caused by the rotation of the Solar System barycenter around the Galactic center. Our results agree with the predicted estimate to be 4-6 micro arcseconds per year (μas/yr) towards α = 266° and δ = -29°. In addition, we tried to detect the quadrupole systematics of the velocity field. Methods: The analysis method consisted of three steps. First, we analyzed geodetic and astrometric VLBI data to produce radio source coordinate time series. Second, we fitted proper motions of 555 sources with long observational histories over the period 1990-2010 to their respective coordinate time series. Finally, we fitted vector spherical harmonic components of degrees 1 and 2 to the proper motion field. Results: Within the error bars, the magnitude and the direction of the dipole component agree with predictions. The dipole vector has an amplitude of 6.4 ± 1.5 μas/yr and is directed towards equatorial coordinates α = 263° and δ = -20°. The quadrupole component has not been detected. The primordial gravitational wave density, integrated over a range of frequencies less than 10-9 Hz, has a limit of 0.0042h-2 where h is the normalized Hubble constant is H0/(100 km s-1). We dedicate this work to the memory of Anne-Marie Gontier, our colleague and personal friend, and a widely recognized specialist of VLBI. She passed away shortly after this paper was submitted.Proper motion data is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/529/A91

  13. Teaching Evolutionary Mechanisms: Genetic Drift and M&M's.

    ERIC Educational Resources Information Center

    Staub, Nancy L.

    2002-01-01

    Describes a classroom activity that teaches the mechanism of genetic drift to undergraduates. Illustrates a number of concepts that are critical in developing evolution literacy by sampling M&M milk chocolate candies. (MM)

  14. Silicon drift detector with reduced lateral diffusion:. experimental results

    NASA Astrophysics Data System (ADS)

    Šonský, J.; Valk, H.; Huizenga, J.; Hollander, R. W.; van Eijk, C. W. E.; Sarro, P. M.

    2000-01-01

    In a standard multi-anode silicon drift detector electron cloud broadening during the drifting towards the anode pixels deteriorates the energy and position resolution. This makes the detector less applicable for detection of low-energy X-rays. The signal charge sharing between several anodes can be eliminated by introducing sawtooth-shaped p + field strips. The sawtooth structure results in small electric fields directed parallel to the sensor surface and perpendicular to the drift direction which produce gutters. The drifting electrons are confined in these gutters of one saw tooth period wide. For a detector with a sawtooth period of 500 μm, we have measured the maximum number of fully confined electrons as a function of the potential gutter depth induced by different sawtooth angles.

  15. 6. VIEW OF DRIFT SHAFT, HOIST MOTOR, WORM WHEEL GEAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF DRIFT SHAFT, HOIST MOTOR, WORM WHEEL GEAR ASSEMBLY, CROSS SHAFT, AND INTERMEDIATE GEAR HOIST ASSEMBLY FOR CONTROL GATE NO. 6, LOOKING WEST - Long Lake Hydroelectric Plant, Spillway Dam, Spanning Spokane River, Ford, Stevens County, WA

  16. The Geodiversity in Drift Sand Landscapes of The Netherlands

    NASA Astrophysics Data System (ADS)

    van den Ancker, Hanneke; Jungerius, Pieter Dirk; Riksen, Michel

    2015-04-01

    The authors carried out detailed field studies of more than twelve drift sand landscapes in The Netherlands. The objective of these studies was to restore Natura-2000 values by restoring the wind activity. Active drift sands occur almost exclusively in The Netherlands, Natura 2000 habitat 2330 'Inland dunes with open Corynephorus and Agrostis grasslands', for which reason our country is largely responsible for this European landscape. Active drift sands had almost disappeared for two reasons: first, the stabilization of the drift sands by air pollution, mainly nitrogen, which stimulates the growth of algae and grasses that initiate soil formation, and second, by the growth of forests surrounding the sands, which decreases the wind force. The restoration studies revealed differences in the geodiversity between and within the drift sand areas. Whereas the drift sands on geological and soil maps show as almost homogenous areas, they have in fact highly variable geo-conditions of which examples will be given. These geodiversity aspects concern differences in geomorphological structure, origin, sediments and age of the drift sands. Differences in wind and water erosion, trampling and soil formation add to the geodiversity within the drift sand areas. Especially in the primary stages of succession the differences in geodiversity are relevant for the Natura-2000 values. We discerned three main types of active sands. Firstly, the impressive drift sands with large parabolic dune structures, often consisting of series of interlocking parabolic dunes. They developed from the northeast towards the southwest, against the direction of the dominant wind, and must have taken centuries to develop. Small parts of these systems are still active, other parts show different degrees of soil formation. Their origin is still unclear but probably dates from medieval times (Heidinga, 1985, Jungerius & Riksen, 2008). Second are the drift sand areas with irregular hills from 0.5 to about 2

  17. REDUCTION OF DRIFT EFFECTS DUE TO SOLAR WIND TURBULENCE

    SciTech Connect

    Burger, R. A.; Visser, D. J.

    2010-12-10

    Gradient and curvature drift play a key role in the modulation of cosmic rays. Reduction in the drift coefficient due to turbulence has been demonstrated unambiguously through direct numerical simulations, but a theory that can explain these results is still lacking. We introduce a parameterized form of the drift coefficient based on direct numerical simulations and show that good agreement with observed proton energy spectra at Earth can be found when it is used in a numerical modulation model. We show that the turbulence ultrascale, for which no observations currently exist, plays an important role in drift reduction. The magnitude at Earth and spatial dependence of this quantity required to fit cosmic-ray observations at Earth are argued to be plausible based on the required properties of the two-dimensional turbulence spectrum at large scales.

  18. Expanding Access

    ERIC Educational Resources Information Center

    Roach, Ronald

    2007-01-01

    There is no question that the United States lags behind most industrialized nations in consumer access to broadband Internet service. For many policy makers and activists, this shortfall marks the latest phase in the struggle to overcome the digital divide. To remedy this lack of broadband affordability and availability, one start-up firm--with…

  19. Easy Access

    ERIC Educational Resources Information Center

    Gettelman, Alan

    2009-01-01

    School and university restrooms, locker and shower rooms have specific ADA accessibility requirements that serve the needs of staff, students and campus visitors who are disabled as a result of injury, illness or age. Taking good care of them is good for the reputation of a sensitive community institution, and fosters positive public relations.…

  20. Access Denied

    ERIC Educational Resources Information Center

    Raths, David

    2012-01-01

    As faculty members add online and multimedia elements to their courses, colleges and universities across the country are realizing that there is a lot of work to be done to ensure that disabled students (and employees) have equal access to course material and university websites. Unfortunately, far too few schools consider the task a top priority.…