WorldWideScience

Sample records for intensive tracer experiment

  1. Tracer dispersion - experiment and CFD

    International Nuclear Information System (INIS)

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  2. The Copenhagen tracer experiments: Reporting of measurements

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Lyck, E.

    2002-01-01

    This is the comprehensive data report from a series of tracer experiment carried out in the Copenhagen area in 1978/79 under neutral and unstable atmospheric conditions. The report contains sulphurhexafluoride of tracer concentrations and meteorologicalmeasurements The tracer was released without...... buoyancy from a tower at a height of 115 meters and then collected 2-3 meters above ground-level at positions in up to three crosswind arcs of tracer sampling units, positioned 2-6 km from the point of release. Three consecutive 20 min averaged tracer concentrations were measured, allowing for a total...... sampling time of 1 hour. The site was mainly residential having a roughness length of 0.6 m. The meteorological measurements performed during the experimentsincluded standard measurements along the tower of tracer release as well as the three-dimensional wind velocity fluctuations at the height of release....

  3. Atmospheric tracer experiments for regional dispersion studies

    International Nuclear Information System (INIS)

    Heffter, J.L.; Ferber, G.J.

    1980-01-01

    Tracer experiments are being conducted to verify atmospheric transport and dispersion calculations at distances from tens to hundreds of km from pollutant sources. In one study, a 2 1/2 year sampling program has been carried out at 13 sites located 30 to 140 km from a source of 85 Kr at the Savannah River Plant in South Carolina. Average weekly concentrations as well as twice-daily concentrations were obtained. Sampling data and meteorological data, including surface, tower, and rawinsonde observations are available on magnetic tape for model verification studies. Some verification results for the Air Resources Laboratories Atmospheric Transort and Dispersion Model (ARL-ATAD) are shown for averaging periods from one week to two years

  4. Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-08-01

    This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

  5. Tracer migration experiments in the Stripa mine 1980-1991

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.

    1992-05-01

    During more than 10 years, tracer experiments have been performed in the Stripa mine as part of the Stripa project to investigate the properties of both 'average' fractured rock and fracture zones. Experiments have been performed that have ranged from a few decimeters, to examine the diffusion into the rock matrix, up to tracer migration to a drift more than 50 meters from the injection point. This report compiles the results and experience that have been gained from all these tracer experiments. The experiments that are described in this report are: * The in-situ diffusion experiment where simultaneous flow and diffusion of tracers in undisturbed rock were studied over more than 3 years to validate diffusivities obtained under laboratory conditions. * Migration in a single fracture where water flow distribution and tracer transport were studied using both conservative and sorbing tracers over migration distances up to 10 meters. * The 3-D migration experiment where water inflow and tracer transport to a drift covered with 350 plastic sheet were investigated to get information on flow porosity, dispersion and channeling. The transport distances were between 10 and 56 meters from the injection points to the drift. * The channeling experiments in which the aim was to examine the channeling properties of single fractures in detail. Pressure pulse tests and tracer experiments were performed over a distances of 2 meters. * The tracer migration experiment in the validation drift where the tracer were injected mainly in a fracture zone and the collection was inside both a drift covered with plastic sheets similar to in the 3-D experiment as well as in a borehole. The distances between injection and sampling location were between 10 and 25 meters. (57 refs.) (au)

  6. Tracer tomography: design concepts and field experiments using heat as a tracer.

    Science.gov (United States)

    Doro, Kennedy O; Cirpka, Olaf A; Leven, Carsten

    2015-04-01

    Numerical and laboratory studies have provided evidence that combining hydraulic tomography with tomographic tracer tests could improve the estimation of hydraulic conductivity compared with using hydraulic data alone. Field demonstrations, however, have been lacking so far, which we attribute to experimental difficulties. In this study, we present a conceptual design and experimental applications of tracer tomography at the field scale using heat as a tracer. In our experimental design, we improve active heat tracer testing by minimizing possible effects of heat losses, buoyancy, viscosity, and changing boundary conditions. We also utilize a cost-effective approach of measuring temperature changes in situ at high resolution. We apply the presented method to the 8 m thick heterogeneous, sandy gravel, alluvial aquifer at the Lauswiesen Hydrogeological Research Site in Tübingen, Germany. Results of our tomographic heat-tracer experiments are in line with earlier work on characterizing the aquifer at the test site. We demonstrate from the experimental perspective that tracer tomography is applicable and suitable at the field scale using heat as a tracer. The experimental results also demonstrate the potential of heat-tracer tomography as a cost-effective means for characterizing aquifer heterogeneity. © 2014, National Ground Water Association.

  7. 3-D migration experiment - report 2: Instrumentation and tracers

    International Nuclear Information System (INIS)

    Abelin, H.; Birgersson, L.; Gidlund, J.

    1987-11-01

    This report is one of the four reports describing the Stripa 3D experiment where water and tracer flow has been monitored in a specially excavated drift in the Stripa mine. The experiment was performed in a specially excavated drift at the 360 m level in granite. The whole ceiling and upper part of the walls were covered with more than 350 individual plastic sheets where the water flow into the drift could be collected. 11 different tracers were injected at distances between 11 and 50 m from the ceiling of the drift. The flow rate and tracer monitoring was kept up for more than two years. The tracer breakthrough curves and flow rate distributions were used to study the flow paths, velocities, hydraulic conductivities, dispersivities and channeling effects in the rock. The report describes the instrumentation developed and used as well as the tracers that were tested and used in the experiment. (orig.)

  8. Use of labeled compounds in tracer experiments

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The use of radiotracers in research has become common. This chapter looks at some of the underlying assumptions and advantages of labeled compounds: advantages of radiotracers; availability of suitable tracers and labeled compounds; purity of labeled compounds; autoradiolysis; storage of labeled compounds; detection systems for chromatography and electrophoretic methods. 14 refs., 2 figs

  9. Our experience of blood flow measurements using radioactive tracers

    International Nuclear Information System (INIS)

    Danet, Bernard.

    1974-01-01

    A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131 I or sup(99m)Tc, 113 In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers ( 133 Xe, 85 Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed [fr

  10. The time and frequency response of tracer experiments

    Science.gov (United States)

    Duffy, Christopher J.; Al-Hassan, Sumani

    1988-01-01

    Two distinctly different approaches to the interpretation of advective and dispersive transport characteristics of an intermediate scale (0-6 m) tracer experiment are examined and compared. The first, or time domain method, is based on a direct analysis of the tracer breakthrough via the widely used moment method. The second, or frequency domain method, is based on a comparison of the Fourier transform of the tracer breakthrough and its theoretical counterpart the frequency response function. Both methods provide satisfactory estimates of the mean advective transport component of the experiment for both conservative and nonconservative tracers. For the sampling ports closest to the source (0-2 m), the moment method produces much larger estimates of the dispersivity than the frequency response method. This difference is attributed to a buildup of errors in the estimation of higher moments, resulting from local variations in the tracer and fluid migration rates within this zone. In the lower part of the caisson (> 2m), the tracer breakthrough is smoother, and both methods provide similar and smaller dispersivity estimates. Overall the frequency domain approach is less sensitive to random variations in the breakthrough response. This idea is illustrated with an example from optimal filtering theory.

  11. Live controls for radioisotope tracer food chain experiments using meiofauna

    International Nuclear Information System (INIS)

    Montagna, P.A.

    1983-01-01

    Formalin poisoned samples are inadequate for measuring the amount of label to be subtracted as control values for certain food chain studies that employ radioactive tracers. In some studies, tracer is added just before incubation to label ''food'' during the feeding study. Commonly, parallel, poisoned incubations are used to distinguish between biotic and abiotic label incorporation. But, a poisoned control does not account for label that could enter a consumer via active transport, epicuticular microfloral uptake, or grazing on labeled, non-food particles. Experiments were performed to test if label uptake is greater in live non-grazing than dead organisms. Marine benthic meiofauna incoporate from 3 to 133 times more tracer when they are alive and not grazing than when they are formalin killed. These results suggest that control experiments with live animals be performed to measure all processes by which label can enter consumers in food chain experiments. (orig.)

  12. Results from some tracer experiments in crystalline rocks in Sweden

    International Nuclear Information System (INIS)

    Abelin, H.; Birgersson, L.; Gidlund, J.; Moreno, L.; Neretinieks, I.; Tunbrant, S.

    1987-01-01

    In a final repository for radioactive waste in crystalline rock, water flowing in the fractures may transport the radionuclides eventually leached from the waste. To be able to predict the migration of the radionuclides, the processes involved must be understood. To quantify the processes, data from flow and transport in real fractures under realistic conditions are needed. Models used for prediction must include descriptions of the important processes and mechanisms. Transport over short distances, i.e., in the vicinity of the canister, most probably occurs in individual fractures. On an intermediate scale where more than a few fractures conduct the flow, well-type tracer tests alone cannot give the detailed information needed to understand dispersion and sorption phenomena in fissured rock. More complex tracer tests are needed to obtain data on pathways and flow porosities. Tests with sorbing tracers are needed to compare predictions based on models and laboratory data, i.e., to validate the transport models. This paper presents the results of tracer experiments conducted in Sweden

  13. Discrete fracture modelling for the Stripa tracer validation experiment predictions

    International Nuclear Information System (INIS)

    Dershowitz, W.; Wallmann, P.

    1992-02-01

    Groundwater flow and transport through three-dimensional networks of discrete fractures was modeled to predict the recovery of tracer from tracer injection experiments conducted during phase 3 of the Stripa site characterization and validation protect. Predictions were made on the basis of an updated version of the site scale discrete fracture conceptual model used for flow predictions and preliminary transport modelling. In this model, individual fractures were treated as stochastic features described by probability distributions of geometric and hydrologic properties. Fractures were divided into three populations: Fractures in fracture zones near the drift, non-fracture zone fractures within 31 m of the drift, and fractures in fracture zones over 31 meters from the drift axis. Fractures outside fracture zones are not modelled beyond 31 meters from the drift axis. Transport predictions were produced using the FracMan discrete fracture modelling package for each of five tracer experiments. Output was produced in the seven formats specified by the Stripa task force on fracture flow modelling. (au)

  14. Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, Melissa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Heredia, Elizabeth [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cohn, Sebastian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Logue, Jennifer [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-01

    This report documents experiments performed in three homes to assess the methodology used to determine air exchange rates using passive tracer techniques. The experiments used four different tracer gases emitted simultaneously but implemented with different spatial coverage in the home. Two different tracer gas sampling methods were used. The results characterize the factors of the execution and analysis of the passive tracer technique that affect the uncertainty in the calculated air exchange rates. These factors include uncertainties in tracer gas emission rates, differences in measured concentrations for different tracer gases, temporal and spatial variability of the concentrations, the comparison between different gas sampling methods, and the effect of different ventilation conditions.

  15. Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

    International Nuclear Information System (INIS)

    Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J.

    2017-01-01

    On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

  16. Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

    Science.gov (United States)

    Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J.

    2017-06-01

    On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

  17. Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J. [Department of Astronomy, University of Wisconsin-Madison, 2535 Sterling Hall, 475 North Charter Street, Madison, WI 53706-1507 (United States)

    2017-06-10

    On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

  18. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1983-05-01

    The Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE) is a program designed to obtain data necessary to evaluate atmospheric transport and diffusion models used to calculate regional population doses caused by nuclear facility emissions to the atmosphere. This experiment will significantly improve the basis for evaluating the cost effectiveness of different methods of managing airborne nuclear wastes. During the period from March 1982 through September 1982, twice daily air samples have been collected at each of five sampling stations located on a radial from the SRP to Murray Hill, NJ (1000 km). Kr-85 emitted from the F and H area chemical separations facilities is being used as a tracer to determine the transport and diffusion of atmospheric releases from the SRP. The Kr-85 concentrations in the air samples will be compared with the calculated concentrations as predicted by the transport and diffusion models. The Kr-85 data and the meteorological data are being archived and will be made available to the modeling community

  19. The application of 3H tracer in soil aerated zone tracing experiment

    International Nuclear Information System (INIS)

    Wu Qinghua; Li Yunfeng; Ji Shaowei; Wang Yubing; Zhao Yingjie

    2000-01-01

    Diffusivity of 3 H was measured in soil aerated zone on both natural and artificial rainfall conditions, migration of 3 H tracer was also studied in loess aerated zone at the same time. The results implied that the migration velocity of 3 H tracer in aerated zone was 0.03 cm/d on natural condition in loess plateau of Hobo Region, the vertical diffusivity D x was 0.10 cm 2 /d. In the experiment pit, the migration velocity was 2.27 cm/d under an artificial condition of 5 mm/h sprinkling intensity for 3 hours each day, the vertical diffusivity D x was 7.75 cm 2 /d

  20. Excavation damage zone tracer experiment in the floor of the room 415 test tunnel

    International Nuclear Information System (INIS)

    Frost, L.H.; Everitt, R.A.

    1997-03-01

    A 3.5-m-diameter test tunnel was constructed on the 420 Level of AECL's Underground Research Laboratory using a mechanical excavation technique. The orientation of the tunnel was chosen to maximize the stress ratio in the plane perpendicular to the tunnel axis in order to promote and study stress-induced excavation damage. The resulting excavation damage zone (EDZ) is characterized by a distinct breakout notch in both the floor and roof of the tunnel. In the floor of the tunnel, the main flow pathway within the EDZ is within a zone of intense grain-size fracturing (process zone) located at the tip of the breakout notch; virtually no flow occurs outside this region. A tracer experiment was performed within the EDZ in the floor of the tunnel to characterize the solute transport properties (permeability, transport porosity and dispersivity) within the process zone, as well as to develop and demonstrate methods for determining the transport properties within EDZs of underground tunnels. The experiment was performed as a constant head test by continuously injecting a constant concentration of iodide tracer into a region of the process zone, and by monitoring tracer breakthrough from the zone at a distance 1.5 m away. An equivalent-porous-media approach was taken in analysing fluid flow and solute transport through the process zone. Based on mass flux calculations, the hydraulic conductivity and transport porosity of the process zone are estimated to be 7.4 x 10 -7 m/s and 2.7 % respectively. Based on an analytic solution that represents tracer transport within the process zone as one-dimensional advective diffusive transport in a finite homogeneous porous medium, the longitudinal dispersivity and transport porosity of the zone are estimated to be 0.60 m and 3.3 % respectively. The transport porosity values estimated by both the mass flux and analytic calculations compare quite well. (author)

  1. Atmospheric Dispersion from Elevated Sources in an Urban Area: Comparison between Tracer Experiments and Model Calculations

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Lyck, Erik

    1984-01-01

    Results from tracer experiments carried out to study the ability of the atmosphere to disperse nonbuoyant effluents released from an elevated point source in an urban environment are described.......Results from tracer experiments carried out to study the ability of the atmosphere to disperse nonbuoyant effluents released from an elevated point source in an urban environment are described....

  2. Development of a methodology for the application of synthetic DNA in stream tracer injection experiments

    NARCIS (Netherlands)

    Foppen, J.W.; Seopa, J.; Bakobie, N.; Bogaard, T.

    2013-01-01

    Stream tracer injection experiments are useful for characterizing hydrological and biogeochemical processes in streams. We used nonconservative synthetic DNA and conservative NaCl in six instantaneous tracer injection experiments in streams in the Benelux. The main aim was to compare the performance

  3. Tracer simulation using a global general circulation model: Results from a midlatitude instantaneous source experiment

    International Nuclear Information System (INIS)

    Mahlman, J.D.; Moxim, W.J.

    1978-01-01

    An 11-level general circulation model with seasonal variation is used to perform an experiment on the dispersion of passive tracers. Specially constructed time-dependent winds from this model are used as input to a separate tracer model. The methodologies employed to construct the tracer model are described.The experiment presented is the evolution of a hypothetical instantaneous source of tracer on 1 Janaury with maximum initial concentration at 65 mb, 36 0 N, 180 0 E. The tracer is assumed to have no sources or sinks in the stratosphere, but is subject to removal processes in the lower troposphere.The experimental results reveal a number of similarities to observed tracer behavior, including the average poleward-downward slope of mixing ratio isopleths, strong tracer gradients across the tropopause, intrusion of tracer into the Southern Hemisphere lower stratosphere, and the long-term interhemispheric exchange rate. The model residence times show behavior intermediate to those exhibited for particulate radioactive debris and gaseous C 14 O 2 . This suggests that caution should be employed when either radioactive debris or C 14 O 2 data are used to develop empirical models for prediction of gaseous tracers which are efficiently removed in the troposphere.In this experiment, the tracer mixing ratio and potential vorticity evolve to very high correlations. Mechanisms for this correlation are discussed. The zonal mean tracer balances exhibit complex behavior among the various transport terms. At early stages, the tracer evolution is dominated by eddy effects. Later, a very large degree of self-cancellation between mean cell and eddy effects is observed. During seasonal transitions, however, this self-cancellation diminishes markedly, leading to significant changes in the zonal mean tracer distribution. A possible theoretical explanation is presented

  4. Site characterization and validation - Tracer migration experiment in the validation drift, report 2, part 1: performed experiments, results and evaluation

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.; Moreno, L.

    1992-01-01

    This report is the second of the two reports describing the tracer migration experiment where water and tracer flow has been monitored in a drift at the 385 m level in the Stripa experimental mine. The tracer migration experiment is one of a large number of experiments performed within the Site Characterization and Validation (SCV) project. The upper part of the 50 m long validation drift was covered with approximately 150 plastic sheets, in which the emerging water was collected. The water emerging into the lower part of the drift was collected in short boreholes, sumpholes. Sex different tracer mixtures were injected at distances between 10 and 25 m from the drift. The flowrate and tracer monitoring continued for ten months. Tracer breakthrough curves and flowrate distributions were used to study flow paths, velocities, hydraulic conductivities, dispersivities, interaction with the rock matrix and channelling effects within the rock. The present report describes the structure of the observations, the flowrate measurements and estimated hydraulic conductivities. The main part of this report addresses the interpretation of the tracer movement in fractured rock. The tracer movement as measured by the more than 150 individual tracer curves has been analysed with the traditional advection-dispersion model and a subset of the curves with the advection-dispersion-diffusion model. The tracer experiments have permitted the flow porosity, dispersion and interaction with the rock matrix to be studied. (57 refs.)

  5. Flow-through column experiments to determine the geochemical behavior of common hydrological tracers

    Science.gov (United States)

    Moola, P. S. N.; Sigfússon, B.; Stefansson, A.

    2015-12-01

    Tracer testing is one of the most effective methods used to study groundwater flow, reservoir characteristics and subsurface properties in geohydrology. Hydrological tracer tests were conducted with the basic assumption that the tracer is chemically inert and non-reactive. However, not all tracers behave non-reactive at different pH conditions, the particular tracer may interact with mineral surfaces in the reservoir. In order to study the geochemical behavior of some common hydrological tracers flow-through column experiments were conducted at 25°C. Six common hydrological tracers were investigated, amino G acid, fluorescein, napthionic acid, pyranine, rhodamine B and rhodamine G in porous rocks consisting of basaltic glass, quartz or rhyolite at pH 3, 6.5 and 9. Homogenous porous material of fixed grain size 45-125μm were dry packed in the column to conduct flow through column experiments. Tracers were pumped at fixed flow rates for 20 minutes and switched back to experimental blank solution and the tracer concentration monitored at the outlet. The measured break-through tracer curves were compared to theoretical 1-D reactive transport simulations calculated using the PHREEQC program (Parkhurst and Appelo, 1999). The data obtained from the breakthrough curves suggest that the tracers may be reactive, non-reactive and partially reactive depending on the rock type and solution pH. The tracers that were observed to be reactive showed the influence of adsorption and desorption. The results suggest that some tracers commonly used in ground water hydrology are not suitable under all conditions as they may react with the rocks of the groundwater system.

  6. On numerical deconvolution for data analysis of tracers' experiments

    International Nuclear Information System (INIS)

    Burgos, Manuel R.; Berne, Philippe

    2002-01-01

    Data analysis of a tracer experiment is performed for studying the plant behavior, impact of procedures' changes and several other goals. In all these cases, the observed data is the convolution of an injection function, and the system's transfer function under study. Practical discrete time convolutions may be performed multiplying a matrix of the process' transfer function with the input vector, but for deconvolution it is necessary to invert the matrix which is singular in a causal system. Another method for deconvolution is by means of Fourier Transforms. Actual readings are usually corrupted by noise and besides its transforms shows high low frequencies components and high frequency ones mainly due to additive noise. Subjective decisions as cut-off frequency should be taken as well. This paper proposes a deconvolution method based on parameters fitting of suitable models, where they exist, and estimation of values where analytical forms are not available. It is based on the global, non linear fitting of them, with a criteria of maximum likelihood. (author)

  7. GTS-LCS, in-situ experiment 2. Modeling of tracer test 09-03

    International Nuclear Information System (INIS)

    Manette, M.; Saaltink, M.W.; Soler, J.M.

    2015-02-01

    Within the framework of the GTS-LCS project (Grimsel Test Site - Long-Term Cement Studies), an in-situ experiment lasting about 5 years was started in 2009 to study water-cement-rock interactions in a fractured granite. Prior to the experiment, a tracer test was performed to characterize the initial flow and transport properties of the rock around the experimental boreholes. This study reports on the model interpretation of tracer test 09-03. The calculations were performed by means of a two-dimensional model (homogeneous fracture plane including 3 boreholes) using the Retraso-CodeBright software package. In the tracer test, Grimsel groundwater containing the tracer (uranine) was circulated in the emplacement borehole during 43 days (zero injection flow rate). Circulation continued without tracer afterwards. Water was extracted at the observation and extraction boreholes. Results from a model sensitivity analysis comparing model results with measured tracer concentrations showed 3 cases where the evolution of tracer concentrations in the 3 different boreholes was satisfactory. In these cases a low-permeability skin affected the emplacement and observation boreholes. No skin appeared to affect the extraction borehole. The background hydraulic gradient seems to have no effect on the results of the tracer test. These results will be applied in the calculation of the initial flow field for the reactive transport phase of in-situ experiment 2 (interaction between pre-hardened cement and fractured granite at Grimsel). (orig.)

  8. Accuracy of tracer stimulus response experiments in laminar flows

    Czech Academy of Sciences Publication Activity Database

    Chlup, Hynek; Novotný, Pavel; Žitný, R.

    2012-01-01

    Roč. 55, 23-24 (2012), s. 6458-6462 ISSN 0017-9310 Institutional research plan: CEZ:AV0Z20760514 Keywords : residence time distribution * tracer injection * laminar convective dominated flow Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 2.315, year: 2012 http://www.sciencedirect.com/science/article/pii/S001793101200470X

  9. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1985-01-01

    A long-range, long-term data set on the regional scale for air pollution model was developed for evaluation. The ACURATE model used Kr-85 emitted intermittently from the Savannah River Plant as a tracer of hourly source emission data at 5 sites for a total of 3858 measurements

  10. Tracer tests - possibilities and limitations. Experience from SKB fieldwork: 1977-2007

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Martin; Crawford, James; Elert, Mark (Kemakta Konsult AB, Stockholm (SE))

    2007-09-15

    Tracer tests have played, and still play, a central role in investigations relating to the understanding of radionuclide retention processes in the field. At present there is a debate within the scientific community concerning how, and to what extent, tracer tests can be used to evaluate large-scale and long-term transport and retardation of radionuclides and other solutes of interest for Safety Assessment of repositories for spent nuclear fuel. In this report the SKB fieldwork on tracer tests performed at Swedish sites from 1977 to 2007 is described and discussed. Furthermore, the knowledge and process understanding evolved during the decades of radionuclide transport experiments and modelling within the SKB programme is summarised. One of the main objectives of this report is to discuss what data and knowledge can be extracted from different in situ tests in a robust fashion. Given the level of complexity associated with transport processes that may occur over the timescale of a tracer test, the utility of tracer tests is considered in the context of evidence-based interpretations of data which we characterise in the form of a sequence of questions of increasing complexity. The complexity of this sequence ranges from whether connection can be confirmed between injection and withdrawal points to whether quantitative data can be extrapolated from a tracer test to be subsequently used in Safety Assessment. The main findings of this report are that: Field scale tracer tests can confirm flow connectivity. Field scale tracer tests confirm the existence of retention. Field scale tracer tests alone can only broadly substantiate our process understanding. However, if performing extensive Site Characterisation and integrating the tracer test results with the full range of geoscientific information available, much support can be given to our process understanding. Field scale tracer tests can deliver the product of the material property group MPG and the F-factor, valid

  11. Use of rare earth oxides and iron oxides as soil erosion tracers in water erosion experiments at hillslope scale

    Science.gov (United States)

    Guzmán, G.; Cañasveras, J. C.; Barrón, V.; Boulal, H.; Gómez, H.; Conde, E.; Fernández, M.; Gómez, J. A.

    2010-05-01

    The characteristics of the ideal soil erosion have been defined by several authors, for example by Zhang et al. (2001). Despite intensive research on erosion tracers in the last decades there is not a single tracer fulfilling all these characteristics. That is why research on different soil erosion tracers remains as an active field. Two desirable characteristics in erosion tracers are that they should be relatively inexpensive (to purchase and analyze) and that they should be determined with high accuracy in soil or sediment. The availability of multiple tracers is another of the key requirements. In this communication we present our preliminary results on the use of two different sets of erosion tracers. One set are iron oxides with different magnetic and optical properties (Fe3O4, α-Fe2O3 and FeOOH) analyzed by NIRS and magnetic susceptibility measurements. The other set consists of five rare earth oxides (La2O3, Pr6O11, Nd2O3, Sm2O3 and Gd2O3) analyzed using inductively coupled plasma mass spectrometry (ICP-MS). These two groups were studied under controlled and natural conditions, through several water erosion experiments, in field plots with different soil management, crops and scale. In one experiment these tracers were used to determine the source of sediment within sprinkle irrigated fields planted with cotton on shoulders. For this purpose, rainfall simulations were performed under controlled conditions at two scales, one with a portable rainfall simulator at small scale (0.81m2) and with the sprinkler irrigation system in the whole cotton field (2450 m2). Furrows were tagged with both groups of tracers, keeping shoulders untagged (where cotton was planted). Soil samples before and after the rainfall simulations were collected as well as sediment samples. In another experiment four olive orchard plots (330 m2) with different soil managements (cover crop and conventional tillage) were also tagged with the two groups of tracers. Soil samples were taken at

  12. A comparison of measurements and calculations for the Stripa tracer experiments

    International Nuclear Information System (INIS)

    Hodgkinson, D.P.; Copper, N.S.

    1992-03-01

    This paper presents a comparison of measurements and predictions for migration of tracers from boreholes to the validation drift and to other boreholes in the Site Characterisation and Validation (SCV) block. The comparison was carried out on behalf of the Stripa task force on fracture flow modelling. The paper summarises the radar/saline tracer experiments, the tracer migration experiment observations and reviews the fracture flow and tracer transport modelling approaches and predictions made by AEA Technology, Fracflow Consultants, Golder Associates and Lawrence Berkeley Laboratory. The predictions are compared with the observed breakthrough curves on the basis of the validation process and criteria defined by the task force. The results of all four modelling groups met the validation criteria, with the predictions of the tracer breakthrough concentrations and times being within an order of magnitude of the observations. Also the AEA and Golder approaches allow the spatial distribution of tracer breakthrough into the validation drift to be predicted and these predictions also showed reasonable accuracy. The successful completion of this project demonstrates the feasibility of discrete fracture flow and tracer transport modelling. (36 refs.) (au)

  13. An airborne perfluorocarbon tracer system and its first application for a Lagrangian experiment

    Science.gov (United States)

    Ren, Y.; Baumann, R.; Schlager, H.

    2015-01-01

    A perfluorocarbon tracer system (PERTRAS), specifically designed for Lagrangian aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS), and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purposes (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: Halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS onboard the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber-gas chromatography-mass spectrometry (TD-GC-MS) system. Guided by forecasts calculated with the Lagrangian model Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol-1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol-1. This indicates that the fresh tracer plume was successfully intercepted at the forecast position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecast. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental setup and comparisons between the measurements and HYSPLIT simulations are presented in this study.

  14. Comparative evaluation of two sediment tracers in a rainfall simulation experiment

    Science.gov (United States)

    Strauss, Peter; Guzman, Gema; Mentler, Axel

    2015-04-01

    The use of sediment tracers tries to contribute to solving problems of traditional soil erosion measurements such as allocation of erosional and depositional areas. A number of different tracing approaches have already been established however, as none of available techniques are able to fully satisfy all the requirements for being an ideal tracer the search for alternative methods continues. Clays tagged with quaternary ammonium compounds are widely used in industry and are easy to incorporate into soils for sediment tracing experiments. To explore the potential of these clays a laboratory experiment was carried out in order to characterize their behaviour as compared to the well-established sediment tracer magnetic iron oxide. The experiment consisted of a simulated rainfall event of 60 mm/h in a box laboratory flume divided in two ridge-furrow subplots (200 x 57 cm). In order to evaluate transport and redistribution of soil from the ridges to the furrow and to measure the dynamic behaviour of the tracers during the rainfall a dense grid of soil samples was taken before and after the experiment (140 samples in total). Runoff and sediment were collected and all samples were analysed for both tracers. Results indicate the general suitability of organophilic clays to monitor soil redistribution by water erosion. The average relative contributions from shoulders and furrow to total sediment export determined by both tracers were similar and indicated a higher contribution from ridges. A key advantage of using organophilic clays is that the detection limit of organophilic clays is extremely low and the background concentration is zero. Despite the inherent differences between both tracers such as way of bounding, sediment enrichment or analytical technique, this experimental comparison of an established and more novel tracer method underscores the potential suitability of the latter for soil erosion studies.

  15. Elevated source SF6-tracer dispersion experiments in the Copenhagen area. Preliminary results II

    International Nuclear Information System (INIS)

    Gryning, S.E.; Lyck, E.

    1980-01-01

    The results from 10 experiments, performed in neutral to unstable meteorological conditions, are reported from an ongoing series of elevated-source, urban-scale tracer dispersion experiments in the Copenhagen area. The tracer is released at a height of 115 m from the TV-tower in GLADSAXE, a suburb of Copenhagen, with tracer sampling units positioned at ground-level in 1 to 3 crosswind series, 2 to 6 km downwind of the tower. The lateral dispersion parameter, sigma(y), was estimated from the measured tracer concentration distribution and compared with values of sigma(y), computed by 1) methods based on wind variance measured during the experiments and 2) methods based on a stability classification of the atmospheric conditions. The wind-variance based methods proved superior in predicting the variation of sigma(y) compared with the stability based methods. Moreover, some of the former methods produced significantly biased estimates of sigma(y). The measured tracer concentration distributions were also crosswind integrated, chi(CWI). Estimates of chi(CWI) were computed using sigma (z) -values derived from the aforementioned computations assuming a Gaussian-type vertical tracer concentration distribution. A comparison is measured and calculated values of chi(CWI) showed no significant differences in the ability of the methods to predict the variation of chi(CWI). Only one method, the EPA, came out with a mean fractional error outside the range +-20% which constitutes the uncertainty in the absolute tracer concentration associated with the calibration of the gas chromatograph for tracer analysis

  16. Remarks relating to field experiments to measure the wet scavenging of tracer aerosols

    International Nuclear Information System (INIS)

    Stensland, G.J.

    1977-12-01

    An important question is whether or not the wet deposition of debris from a single (or multiple) airburst of a nuclear device poses a significant hazard to people on the ground. To answer this question for various scenarios, a basic understanding of the aerosol attachment rates to cloud water and raindrops is needed. The attachment rates can then be incorporated into the cloud physics scavenging models to make intelligent assessments. In order to gain an initial impression as to the importance (order of magnitude) of the wet scavenging effects and to provide the data to validate the cloud scavenging models, tracer release field experiments are useful and necessary. The major purpose of this report is to address questions related to the operation and interpretation of such field tracer efforts and in particular to consider the results from the August 3, 1972, Battelle Northwest Laboratory tracer experiment in St. Louis. The Battelle experiment involved the release of several aerosol tracers at 10,000 to 13,000 feet, near rain clouds, and the measurement of the resulting tracer in the rain collected at the ground level sampling sites

  17. Interpretation of injection-withdrawal tracer experiments conducted between two wells in a large single fracture.

    Science.gov (United States)

    Novakowski, K S; Bickerton, G; Lapcevic, P

    2004-09-01

    Tracer experiments conducted using a flow field established by injecting water into one borehole and withdrawing water from another are often used to establish connections and investigate dispersion in fractured rock. As a result of uncertainty in the uniqueness of existing models used for interpretation, this method has not been widely used to investigate more general transport processes including matrix diffusion or advective solute exchange between mobile and immobile zones of fluid. To explore the utility of the injection-withdrawal method as a general investigative tool and with the intent to resolve the transport processes in a discrete fracture, two tracer experiments were conducted using the injection-withdrawal configuration. The experiments were conducted in a fracture which has a large aperture (>500 microm) and horizontally pervades a dolostone formation. One experiment was conducted in the direction of the hydraulic gradient and the other in the direction opposite to the natural gradient. Two tracers having significantly different values of the free-water diffusion coefficient were used. To interpret the experiments, a hybrid numerical-analytical model was developed which accounts for the arcuate shape of the flow field, advection-dispersion in the fracture, diffusion into the matrix adjacent to the fracture, and the presence of natural flow in the fracture. The model was verified by comparison to a fully analytical solution and to a well-known finite-element model. Interpretation of the tracer experiments showed that when only one tracer, advection-dispersion, and matrix diffusion are considered, non-unique results were obtained. However, by using multiple tracers and by accounting for the presence of natural flow in the fracture, unique interpretations were obtained in which a single value of matrix porosity was estimated from the results of both experiments. The estimate of porosity agrees well with independent measurements of porosity obtained from

  18. C-13 Tracer experiments and metabolite balancing for metabolic flux analysis

    DEFF Research Database (Denmark)

    Schmidt, Karsten; Marx, A.; de Graaf, A. A.

    1998-01-01

    through the pentose phosphate pathway. Hence, wrong assumptions on the presence or activity of transhydrogenation reactions will result in wrong estimations of the intracellular flux distribution. Using C-13 tracer experiments and NMR analysis, flux analysis can be performed on the basis of only well...

  19. Isotopes as tracers of the oceanic circulation: Results from the World Ocean Circulation Experiment

    International Nuclear Information System (INIS)

    Schlosser, P.; Jenkins, W.J.; Key, R.; Lupton, J.

    2002-01-01

    During the past decades, natural and anthropogenic isotopes such as tritium ( 3 H), radiocarbon ( 14 C), 3 He, or the stable isotopes of water have been used in studies of the dynamics of natural systems. Early applications of tracers to studies of the ocean were directed at determination of circulation patterns and mean residence times of specific water masses, as well as estimates of mixing coefficients. These exploratory studies suggested that tracers can add significantly to our understanding of the oceanic circulation. In order to fully exploit this potential, the first global tracer study, the GEochemical Ocean SECtions Study (GEOSECS), was launched. From the GEOSECS results it was immediately apparent that very close coordination of tracer programs with physical oceanography studies is required for full utilization of tracer data. During the 1980s plans for the World OCean Experiment (WOCE) were developed. As part of its Hydrographic Program (WHP), especially during the one-time survey, a set of tracers were measured on a global scale with unprecedented spatial resolution (both lateral and vertical). The original plan included a larger number of tracers (CFCs, 3 H/ 3 He, 14 C, 39 Ar, stable isotopes of water, helium isotopes, 228 Ra, 90 Sr, 137 Cs, 85 Kr) than could actually be measured systematically (CFCs, 3 H/ 3 He, 14 C, H 2 18 O/H 2 16 O, helium isotopes). Nevertheless, the resulting data set, which presently is under evaluation, exceeds those obtained from pre-WOCE tracer studies by a wide margin. In this contribution, we describe the existing WOCE data set and demonstrate the type of results that can be expected from its interpretation on the basis of a few selected examples. These examples include: (1) the application of tritium and 3 He to studies of the ventilation of the upper waters in the Pacific Ocean, (2) the spreading of intermediate water in the Pacific and Indian oceans as derived from the distribution of 3 He, and (3) the evaluation of

  20. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, A. [Conterra AB, Uppsala (Sweden); Andersson, Peter [Geosigma AB, Uppsala (Sweden); Hermanson, Jan [Golder Grundteknik, Solna (Sweden); Byegaard, Johan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Cvetkovic, V. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Water Resources Engineering; Birgersson, Lars [Kemakta Konsult AB, Stockholm (Sweden)

    2000-03-15

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (< 0.5 m), detailed scale (< 10 m) and block scale (10-50 m). The First TRUE Stage was performed in the detailed scale with the specific objectives of providing data and conceptualising the investigated feature using conservative and sorbing tracers. Further, to improve methodologies for performing tracer tests, and to develop and test a methodology for obtaining pore volume/aperture data from epoxy resin injection, excavation and subsequent analyses. The experimental site is located at approximately 400 m depth in the northeastern part of the Aespoe Hard Rock Laboratory. The identification of conductive fractures and the target feature has benefited from the use of BIPS borehole TV imaging combined with detailed flow logging. The assessment of the conductive geometry has been further sustained by cross-hole pressure interference data. The investigated target feature (Feature A) is a reactivated mylonite which has later undergone brittle deformation. The feature is oriented northwest, along the principal horizontal stress orientation, and is a typical conductor for Aespoe conditions. Hydraulic characterisation shows that the feature is relatively well isolated

  1. Analysis of tracer responses in the BULLION Forced-Gradient Experiment at Pahute Mesa, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Reimus; Marc J. Haga

    1999-10-01

    This report presents an analysis of the tracer data from the BULLION forced-gradient experiment (FGE) conducted on Pahute Mesa at the Nevada Test Site from June 2, 1997 through August 28, 1997, for the Underground Test Area (UGTA) Program. It also serves to document the polystyrene microsphere data from the FGE. The FGE involved the injection of solute and colloid tracers into wells ER-20-6 No. 1 and ER-20-6 No. 2 while ER-20-6 No. 3 was pumped at approximately 116 gallons per minute (gpm). The experimental configuration and test design are described briefly in this report; more details are provided elsewhere (IT, 1996, 1997, 1998). The tracer responses in the various wells yielded valuable information about transport processes such as longitudinal dispersion, matrix diffusion and colloid transport in the hydrogeologic system in the vicinity of the BULLION nuclear test cavity. Parameter values describing these processes are derived from the semi-analytical model interpretations presented in this report. A companion report (IT, 1998) presents more detailed numerical modeling interpretations of the solute tracer responses.

  2. The Tianlai 21cm intensity mapping experiment

    Science.gov (United States)

    Chen, Xuelei

    2015-08-01

    The Tianlai 21cm intensity mapping experiment is aimed at surveying the northern sky 21cm intensity at mid-redshifts, thus map out the neutral hydrogen distribution. The experiment is named "Tianlai" which means "heavenly sound" in classic Chinese, because its ultimate goal is to use the baryon acoustic oscillation (BAO) feature in the correlation function or power spectrum of large scale structure to constrain the cosmic expansion rate, and determine the nature of dark energy.The pathfinder experiment consists three cylinder reflectors of 15m wide x 40m long, and 16 dishes of 6 meter aperture, for testing the basic principle and key technologies. A radio-quiet site in Hongliuxia, Xinjiang of north-west China is selected, currently the facilities are under construction, and the prototype is expected to start commissioning later this year. The experiment is run by NAOC, with members from France, USA and Canada.

  3. Salt tracer experiments in wetland ponds: will density stratification spoil the outcome?

    Science.gov (United States)

    Schmid, Bernhard H.; Hengl, Michael A.

    2017-04-01

    Wetland ponds are among the treatment options for peatland flows prior to their discharge into a receiving ambient water course or water body. The removal efficiency and effectiveness of wetland ponds (free water surface or FWS wetlands) is considered to be strongly related to the residence time or travel time distribution in the pond, with a narrow distribution (close to plug flow) being preferable to a wider one. This travel time distribution is, in turn, reflected by a breakthrough curve of an ideal tracer injected instantaneously into the flow (entering the wetland). As the term 'ideal tracer' suggests, such a substance, in real world cases, does not exist and can, at best, be approximated by a real tracer. Among the tracer groups in most widespread use, salt has the advantage of low cost, straightforward detection and analysis as well as low related environmental risk. In contrast, use of radioactive artificial tracers may meet with resistance from authorities and public, and fluorescent dyes are not necessarily devoid of problems, either (as recently discovered, there are two structural isomers of Rhodamin WT, the mixture of which may compromise the validity of breakthrough data analyses). From previous work by the authors it is known that density stratification may result from the injection of a salt tracer into a low Reynolds number free surface flow, which is a frequent characteristic of wetland ponds. As the formation of density layers in the course of a tracer experiment is highly undesirable, it may be useful to judge prior to beginning of the field work, if stratification is to be expected (and the experimental design should, consequently, be adapted suitably). The current work reported here employs an energy argument to extend existing criteria for density stratification in turbulent free surface flows. Vertical mixing is assumed to be sustained by a fraction of the frictional energy loss (expressed by Manning's law, but this can easily be adapted to

  4. An intensive tree-ring experience

    NARCIS (Netherlands)

    Sánchez-Salguero, Raúl; Hevia, Andrea; Camarero, J.J.; Treydte, Kerstin; Frank, Dave; Crivellaro, Alan; Domínguez-Delmás, Marta; Hellman, Lena; Kaczka, Ryszard J.; Kaye, Margot; Akhmetzyanov, Linar; Ashiq, Muhammad Waseem; Bhuyan, Upasana; Bondarenko, Olesia; Camisón, Álvaro; Camps, Sien; García, Vicenta Constante; Vaz, Filipe Costa; Gavrila, Ionela G.; Gulbranson, Erik; Huhtamaa, Heli; Janecka, Karolina; Jeffers, Darren; Jochner, Matthias; Koutecký, Tomáš; Lamrani-Alaoui, Mostafa; Lebreton-Anberrée, Julie; Seijo, María Martín; Matulewski, Pawel; Metslaid, Sandra; Miron, Sergiu; Morrisey, Robert; Opdebeeck, Jorgen; Ovchinnikov, Svyatoslav; Peters, Richard; Petritan, Any M.; Popkova, Margarita; Rehorkova, Stepanka; Ariza, María O.R.; Sánchez-Miranda, Ángela; Linden, Van der Marjolein; Vannoppen, Astrid; Volařík, Daniel

    2017-01-01

    The European Dendroecologial Fieldweek (EDF) provides an intensive learning experience in tree-ring research that challenges any participant to explore new multidisciplinary dendro-sciences approaches within the context of field and laboratory settings. Here we present the 25th EDF, held in

  5. Optimal tracers for parallel labeling experiments and13C metabolic flux analysis: A new precision and synergy scoring system.

    Science.gov (United States)

    Crown, Scott B; Long, Christopher P; Antoniewicz, Maciek R

    2016-11-01

    13 C-Metabolic flux analysis ( 13 C-MFA) is a widely used approach in metabolic engineering for quantifying intracellular metabolic fluxes. The precision of fluxes determined by 13 C-MFA depends largely on the choice of isotopic tracers and the specific set of labeling measurements. A recent advance in the field is the use of parallel labeling experiments for improved flux precision and accuracy. However, as of today, no systemic methods exist for identifying optimal tracers for parallel labeling experiments. In this contribution, we have addressed this problem by introducing a new scoring system and evaluating thousands of different isotopic tracer schemes. Based on this extensive analysis we have identified optimal tracers for 13 C-MFA. The best single tracers were doubly 13 C-labeled glucose tracers, including [1,6- 13 C]glucose, [5,6- 13 C]glucose and [1,2- 13 C]glucose, which consistently produced the highest flux precision independent of the metabolic flux map (here, 100 random flux maps were evaluated). Moreover, we demonstrate that pure glucose tracers perform better overall than mixtures of glucose tracers. For parallel labeling experiments the optimal isotopic tracers were [1,6- 13 C]glucose and [1,2- 13 C]glucose. Combined analysis of [1,6- 13 C]glucose and [1,2- 13 C]glucose labeling data improved the flux precision score by nearly 20-fold compared to widely use tracer mixture 80% [1- 13 C]glucose +20% [U- 13 C]glucose. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  6. Field tracer transport experiments at the site of Canada's underground research laboratory

    International Nuclear Information System (INIS)

    Frost, L.H.; Davison, C.C.; Vandergraaf, T.T.; Scheier, N.W.; Kozak, E.T.

    1997-01-01

    To gain a better understanding of the processes affecting solute transport in fractured crystalline rock, groundwater tracer experiments are being performed within natural fracture domains and excavation damage zones at various scales at the site of AECL's Underground Research Laboratory (URL). The main objective of these experiments is to develop and demonstrate methods for characterizing the solute transport properties within fractured crystalline rock. Estimates of these properties are in turn being used in AECL's conceptual and numerical models of groundwater flow and solute transport through the geosphere surrounding a nuclear fuel waste disposal vault in plutonic rock of the Canadian Shield. (author)

  7. A concept for limiting the number of radioactive tracer experiments in a factory plant

    International Nuclear Information System (INIS)

    Monchy, A.R. de

    1980-01-01

    There are currently no restrictions regarding the quantities of radioactive material stored, used or discharged in factories where radioactive tracer experiments are performed. This article describes a concept for such restrictions, based on two criteria - 1) a system of standards for the absorption of the contamination by either water or air, dependent on the half life of the nuclides used and 2) a summation procedure of the activities of the nuclides used, the activities being weighed by the toxicity and chance of spreading of each nuclide. (C.F.)

  8. Discrete fracture network modeling of tracer migration experiments at the Kamaishi mine

    International Nuclear Information System (INIS)

    Uchida, Masahiro; Sawada, Atsushi

    1995-01-01

    This paper presents the results of a discrete fracture network modeling for the non-sorbing tracer migration experiments, which were conducted in the fractured rock at the Kamaishi mine. A newly developed in-plane heterogeneity model, which can address the channeling effects within a fracture, and the matrix diffusion model, which can simulate the retardation time due to the matrix diffusion adjacent to fracture were applied in this study. As a result, the matrix diffusion model better reproduces the general shape of breakthrough curves. The transport aperture A t was approximately one order of magnitude larger than the hydraulic aperture A c derived from the cubic law

  9. Tracer gas experiment to verify the dispersion from a tall stack

    International Nuclear Information System (INIS)

    Sivertsen, B.; Irwin, J.S.

    1996-01-01

    At the request of the Ministerios de Obras Publicas y Urbanismo (MOPU) in Madrid, the Norwegian Institute for Air Research (NILU) planned and carried out a comprehensive field experiment at the Andorra (Teruel) power plant in Spain. All together, eleven releases of sulfur hexafluoride (SF6) tracer were carried out at the 1,200 MW electric coal fired power plant. The tracer was emitted into the atmosphere from the 343 m high stack, stack exit diameter of 9 m. The stack gas emission characteristics were nearly constant during the period having an exit temperature of 175.1 C (1.9), exit velocity of 35.5 m/s (0.14) and sulfur dioxide (SO 2 ) emission rate of 46.1 x 10 3 kg/hr (5.15 x 10 3 ); standard deviations are listed in parentheses. Samples were taken at the surface along sampling arcs located approximately 8, 23, 43 and 75 km downwind. The releases were undertaken during typical late spring daytime conditions. The synoptic weather conditions were dominated by a large high pressure system on the Atlantic, west of Spain. Fronts were passing the area from the north and a low pressure system was developing over central Europe (Germany). Winds at the surface were generally brisk from the northwest at 7 to 12 m/s

  10. Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers.

    Science.gov (United States)

    Wildemeersch, S; Jamin, P; Orban, P; Hermans, T; Klepikova, M; Nguyen, F; Brouyère, S; Dassargues, A

    2014-11-15

    Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54MJ/m(3)/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for

  11. Numerical Analysis of a Short-Term Tracer Experiment in Fractured Sandstone

    Directory of Open Access Journals (Sweden)

    Tai-Sheng Liou

    2007-01-01

    Full Text Available A short-term, pulse injection tracer experiment conducted in fractured quartzitic sandstone at Kukuan, Taiwan was analyzed. Tracer transport at the test site was dominated by advection but a specific attenuation mechanism leading to breakthrough curve (BTC tailing also seemed to exist. Matrix diffusion was hypothesized as the transport mechanism that results in the tailing. This hypothesis was proved by comparing the field BTC with numerical simulation results obtained by the general-purpose flow/transport simulator, TOUGH2, based on a single-fracture conceptual model. Due to the lack of accuracy of estimating the interporosity flux by the conventional double porosity model (DPM, TOUGH2 was incorporated with the multiple interacting continua (MINC scheme to simulate the transient characteristics of the interporosity flux. In MINC, rock matrix is discretized as a series of continua according to the perpendicular distance from the fracture that adjoins the matrix. The closer the rock matrix is to the fracture, the finer the rock matrix is discretized. This concept is fundamentally different from DPM in that rock matrix is no longer treated as a single continuum. Simulation results by TOUGH2-MINC have successfully reproduced the observed BTC tailing even under the dominating advection effect. Sensitivity studies showed that TOUGH2-MINC is sensitive to parameters including fracture aperture (2b, matrix porosity (nm and effective molecular diffusion coefficient in matrix (Dm. If 2b, nm , Dm , are respectively 200 _?¿m, 2%, 10-11 m2 s -1, and if hydrodynamic dispersion coefficient (D is 1.69 ¡__n10-6 m2 s -1, TOUGH2-MINC result can well fit the field BTC. Furthermore, the importance of matrix diffusion was verified by fitting the field BTC with analytical solutions that either neglect matrix diffusion or consider the mass exchange between mobile and immobile zones within the fracture as the attenuation transport mechanism. It was found that the BTC

  12. Numerical Analysis of a Short-Term Tracer Experiment in Fractured Sandstone

    Directory of Open Access Journals (Sweden)

    Tai-Sheng Liou

    2007-01-01

    Full Text Available A short-term, pulse injection tracer experiment conducted in fractured quartzitic sandstone at Kukuan, Taiwan was analyzed. Tracer transport at the test site was dominated by advection but a specific attenuation mechanism leading to breakthrough curve (BTC tailing also seemed to exist. Matrix diffusion was hypothesized as the transport mechanism that results in the tailing. This hypothesis was proved by comparing the field BTC with numerical simulation results obtained by the general-purpose flow/transport simulator, TOUGH2, based on a single-fracture conceptual model. Due to the lack of accuracy of estimating the interporosity flux by the conventional double porosity model (DPM, TOUGH2 was incorporated with the multiple interacting continua (MINC scheme to simulate the transient characteristics of the interporosity flux. In MINC, rock matrix is discretized as a series of continua according to the perpendicular distance from the fracture that adjoins the matrix. The closer the rock matrix is to the fracture, the finer the rock matrix is discretized. This concept is fundamentally different from DPM in that rock matrix is no longer treated as a single continuum. Simulation results by TOUGH2-MINC have successfully reproduced the observed BTC tailing even under the dominating advection effect. Sensitivity studies showed that TOUGH2-MINC is sensitive to parameters including fracture aperture (2b, matrix porosity (nm and effective molecular diffusion coefficient in matrix (Dm. If 2b, nm , Dm , are respectively 200 _ 2%, 10-11 m2 s -1, and if hydrodynamic dispersion coefficient (D is 1.69 _ m2 s -1, TOUGH2-MINC result can well fit the field BTC. Furthermore, the importance of matrix diffusion was verified by fitting the field BTC with analytical solutions that either neglect matrix diffusion or consider the mass exchange between mobile and immobile zones within the fracture as the attenuation transport mechanism. It was found that the BTC tailing can

  13. The Experience of Receiving and Then Losing a Scholarship: A Tracer Study of Secondary School Scholarship Recipients in Uganda

    Science.gov (United States)

    Watson, Cathy; Chapman, David W.; Okurut, Charles Opolot

    2014-01-01

    This study reports findings of a tracer that investigated differences in the profile and subsequent experiences of scholarship recipients in Uganda who were able to complete the lower secondary school cycle (O level) without interruption (N = 174) and those that dropped out before completing their O-level cycle (N = 51), thereby losing their…

  14. Effects from influent boundary conditions on tracer migration and spatial variability features in intermediate-scale experiments

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Springer, E.P.

    1987-04-01

    In previous unsaturated transport studies at Los Alamos dispersion coefficients were estimated to be higher close to the tracer source than at greater distances from the source. Injection of tracers through discrete influent outlets could have accounted for those higher dispersions. Also, a lack of conservation of mass of the tracers was observed and suspected to be due to spatial variability in transport. In the present study experiments were performed under uniform influent (ponded) conditions in which breakthrough of tracers was monitored at four locations at each of four depths. All other conditions were similar to those of the unsaturated transport experiments. A comparison of results from these two sets of experiments indicates differences in the parameter estimates. Estimates were made for the dispersion coefficient and the retardation factor by the one-dimensional steady flow computer code, CFITIM. Estimates were also made for mass and for velocity and the dispersion coefficient by the method of moments. The dispersion coefficient decreased with depth under discrete influent application and increased with depth under ponded influent application. Retardation was predicted better under the discrete influent application than under ponded influent application. Differences in breakthroughs and in estimated parameters among locations at the same depth were observed under ponded influent application. Those differences indicate that there is a lack of conservation of mass as well as significant spatial variability across the experimental domain. 14 refs., 9 figs., 8 tabs

  15. Predicted fate of tritium residuum from groundwater tracer experiments in the Amargosa Desert, southern Nevada

    International Nuclear Information System (INIS)

    Brikowski, T.

    1993-07-01

    Analytic solutions are used in this study to evaluate potential groundwater transport of tritium used in goundwater tracer tests southwest of the Nevada Test Site. Possible transport from this site is of interest because initial radionuclide concentrations were high and the site is close to goundwater discharge points (12 km). Anecdotal evidence indicates that 90 percent of these tracers were removed by pumping at the completion of the tests; this study examines the probable transport of the tracers with and without the removal. Classical dispersive transport analytic solutions are used, treating the tracer test as a point slug injection. Input parameters for the solutions were measured at the site, and consideration of parameter uncertainty is incorporated in the results. With removal of the tracer, the maximum expected region with above-Safe Drinking Water Act (40 CFR 121) concentrations of tritium extends 5 km from the injection point, and does not reach any sites of public access. Detectable tritium from the tests is likely to have reached the Ash Meadows fault zone, but flow along the fault probably diluted the tracer to below detection limits before arrival at springs along the fault. Arrival at the springs would have occurred 20 to 25 years after the tests. Without removal of the tracer, the solutions indicate that tritium concentrations just above Safe Drinking Water Act standards would have reached the Ash Meadows fault zone. In this case, detectable tritium might have been found in Devil's Hole or Longstreet Spring, the nearest points of possible public exposure

  16. The evaluation of data from the MACRO tracer experiment. The report for Japan Nuclear Cycle Development Institute

    International Nuclear Information System (INIS)

    Watari, Shingo

    1999-12-01

    On understanding the radionuclide transport in Natural Barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, Japan Nuclear Cycle Development Institute (JNC) developed the MACRO experiment with an artificial heterogeneous permeability field and has been conducted lots of tracer experiments. To estimate the effect of characteristics of field on the macroscopic dispersion using data from those tracer experiments, the evaluation of dispersion coefficient is required. In this report, the macroscopic dispersion coefficients were evaluated for the results of the tracer experiments using the MACRO facility with a single well. The coefficients for the experiments of 18 cases were evaluated by the fitting of analytical solution to the breakthrough curve measured in the well. In the evaluations, the correction of data measured in the experiments and of the accuracy in the evaluation were considered. The conclusions are as follows. The macroscopic dispersion coefficients for 18 cases were evaluated using Least Square Method by fitting the analytical evaluation to the result of experiment. Consequently, the coefficients for 7 cases were evaluated with not enough accurate fitting results. Therefore, another evaluations for those 7 cases were required to be with more accuracy. Then, those coefficients were evaluated with enough accuracy. It was verified that the macroscopic dispersion coefficient tend to be increased with increase of the average radius of tracer front. In some cases, however, the trend was not verified because of the limit of accuracy for data measured in the experiment and for the evaluation method of the coefficient. It was found that the macroscopic dispersion coefficients evaluated for the cases with heterogeneous permeability field type B tend to be higher than those with heterogeneous permeability field type A. (author)

  17. The patient experience of intensive care

    DEFF Research Database (Denmark)

    Egerod, Ingrid; Bergbom, Ingegerd; Lindahl, Berit

    2015-01-01

    BACKGROUND: Sedation practices in the intensive care unit have evolved from deep sedation and paralysis toward lighter sedation and better pain management. The new paradigm of sedation has enabled early mobilization and optimized mechanical ventilator weaning. Intensive care units in the Nordic c...... state, where they face the choice of life or death. Caring nurses and family members play an important role in assisting the patient to transition back to life....

  18. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment.

    Science.gov (United States)

    Zhang, X L; Su, G F; Chen, J G; Raskob, W; Yuan, H Y; Huang, Q Y

    2015-10-30

    Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r=0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Locating the Source of Atmospheric Contamination Based on Data From the Kori Field Tracer Experiment

    Directory of Open Access Journals (Sweden)

    Piotr Kopka

    2015-01-01

    Full Text Available Accidental releases of hazardous material into the atmosphere pose high risks to human health and the environment. Thus it would be valuable to develop an emergency reaction system which can recognize the probable location of the source based only on concentrations of the released substance as reported by a network of sensors. We apply a methodology combining Bayesian inference with Sequential Monte Carlo (SMC methods to the problem of locating the source of an atmospheric contaminant. The input data for this algorithm are the concentrations of a given substance gathered continuously in time. We employ this algorithm to locating a contamination source using data from a field tracer experiment covering the Kori nuclear site and conducted in May 2001. We use the second-order Closure Integrated PUFF Model (SCIPUFF of atmospheric dispersion as the forward model to predict concentrations at the sensors' locations. We demonstrate that the source of continuous contamination may be successfully located even in the very complicated, hilly terrain surrounding the Kori nuclear site. (original abstract

  20. Quantifying Reaeration Rates in Alpine Streams Using Deliberate Gas Tracer Experiments

    Directory of Open Access Journals (Sweden)

    Andrew Benson

    2014-04-01

    Full Text Available Gas exchange across the air-water interface is a critical process that maintains adequate dissolved oxygen (DO in the water column to support life. Oxygen reaeration rates can be accurately measured using deliberate gas tracers, like sulfur hexafluoride (SF6 or xenon (Xe. Two continuous release experiments were conducted in different creeks in the Sierra Nevada of California: Sagehen Creek in September, 2009, using SF6 and Martis Creek in August, 2012, using both SF6 and Xe. Measuring gas loss along the creek, which was approximated with the one-dimensional advection-dispersion equation, allows for the estimation of the SF6 or Xe reaeration coefficient (KSF6, KXe, which is converted to DO reaeration (KDO or K2 using Schmidt numbers. Mean KSF6 for upper and lower Sagehen and Martis Creeks were, respectively, 34 day−1, 37 day−1 and 33 day−1, with corresponding KDOs of 61 day−1, 66 day−1 and 47 day−1. In Martis Creek, KXe was slightly higher (21% than KSF6, but the calculated KDO from SF6 agreed with the calculated KDO from Xe within about 15%; this difference may be due to bubble-enhanced gas transfer. Established empirical equations of KDO using stream characteristics did a poor job predicting KDO for both creeks.

  1. Inversion of the Borden Tracer Experiment Data: Investigation of Stochastic Moment Models

    Science.gov (United States)

    Woodbury, Allan D.; Sudicky, E. A.

    1992-09-01

    Inversion of Dagan's two- and three-dimensional stochastic models using Freyberg's (1986), Rajaram and Gelhar's (1988, 1991), and Barry and Sposito's (1990) moment data from the Borden experiment is carried out to examine (1) the validity of the two-dimensional (Dagan, 1982) and three-dimensional (Dagan, 1988) models and (2) the reduction in uncertainty of the spatial moments over nonconditioned estimates. A direct application of Bayesian statistical inference, in conjunction with Monte Carlo integration, is used to produce posterior probability density functions for the parameters. The parameter ranges from all methods show horizontal integral scales λ between 1.85 and 4.04 m, vertical integral scales λz between 0.144 and 0.459 m, and log hydraulic conductivities In (K) between 0.120 and 0.197. These results compare well to the earlier estimates of Woodbury and Sudicky (1991) and Robin et al. (1991). We show that moment prediction uncertainty is substantially reduced when both tracer moment data and prior estimates of the In (K) geostatistical parameters are incorporated into theoretical formulae based on stochastic dispersion theory.

  2. Multitracing Experiment With Solved and Particulate Tracers In An Unsaturated Field Soil

    Science.gov (United States)

    Burkhardt, M.; Kasteel, R.; Vereecken, H.

    Solute movement and colloid migration follow preferential flow paths in structured soils at the field scale. The use of microsphreres is a possible option to mimic colloid transport through the vadose zone into the groundwater. We present results of multi- tracing experiments conducted in an Orthic Luvisol using bromide (Br-), the reactive dye tracer Brilliant Blue (BB) and microspheres. The fluorescent microspheres (1 and 10 µm in diameter) were functionalized with a negative surface charge. Eight field plots (about 2 m2) were irrigated with 10 mm and 40 mm during 6 h. Four field plots were sampled directly after the irrgation, the others were exposed for 90 days to natural wheather conditions. Photographs of horizontal cross-sections and disturbed soil sam- ples were taken every 5 to 10 cm down to a depth of 160 cm. Image analysis was used to derive concentration distributions of BB using a calibration relationship between concentration and color spectra. The microspheres were quantified after desorption of the soil samples by fluorescent microscopy and image analysis. We used moment analysis to characterize transport phenomena. We found that transport through the soil matrix was affected by sorption, but all of the applied compounds were transported through preferential flow paths (earthworm burrows) down to a depth of 160 cm irre- spective of their chemical properties. Furthermore, this study shows that microspheres can be used to mimic colloid facilitated transport under unsaturated conditions in a field soil.

  3. TRACER: an 'eye-opener' to the patient experience across the transition of care in an internal medicine resident program.

    Science.gov (United States)

    Meade, Lauren B; Hall, Susana L; Kleppel, Reva W; Hinchey, Kevin T

    2015-01-01

    A safe patient transition requires a complex set of physician skills within the interprofessional practice. To evaluate a rotation which applies self-reflection and workplace learning in a TRAnsition of CarE Rotation (TRACER) for internal medicine (IM) residents. TRACER is a 2-week required IM resident rotation where trainees join a ward team as a quality officer and follow patients into postacute care. In 2010, residents participated in semistructured, one-on-one interviews as part of ongoing program evaluation. They were asked what they had learned on TRACER, the year prior, and how they used those skills in their practice. Using transcripts, the authors reviewed and coded each transcript to develop themes. Five themes emerged from a qualitative, grounded theory analysis: seeing things from the other side, the 'ah ha' moment of fragmented care, team collaboration including understanding nursing scope of practice in different settings, patient understanding, and passing the learning on. TRACER gives residents a moment to breathe and open their eyes to the interprofessional practice setting and the patient's experience of care in transition. Residents learn about transitions of care through self-reflection. This learning is sustained over time and is valued enough to teach to their junior colleagues.

  4. Plutonium and tracer particle resuspension: an overview of selected Battelle-Northwest experiments

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1977-01-01

    Plutonium resuspension at Rocky Flats was determined in July 1973, by measuring airborne plutonium as a function of sampling height and of wind speed. The maximum airborne plutonium-239 concentration was 3700 aCi/m 3 . The maximum plutonium-239 activity per gram of collected airborne soil was 50 pCi/g. Airborne plutonium concentrations were shown to increase as the sixth power of wind speed, but the data were very imprecise. In measurement of fallout resuspension caused by burning vegetation, the 137 Cs concentration in a forest fire smoke plume was 22 times the concentration in ambient air. Resuspension rates for a man walking across a tracer area on an asphalt surface ranged from 1 x 10 -5 to 7 x 10 -4 fraction of tracer resuspended/pass. For vehicular traffic driven on a tracer lane, resuspension rates from the asphalt surface ranged from 10 -4 to 10 -2 fraction resuspended/pass. When the vehicle was driven on the lane adjacent to the tracer lane, resuspension rates were smaller, ranging from 10 -5 to 10 -3 fraction resuspended/pass. Resuspension rates decreased when the tracer had been on the ground for several days. In comparison to the asphalt surface, vehicle-caused tracer resuspension rates from a cheat grass area were lower, ranging from 10 -5 to 10 -4 fraction resuspended/pass. Wind caused tracer resuspension rates were on the order of 10 -11 fraction resuspended/sec for nonrespirable particles. Resuspension rates for respirable particles increased as the 4.8th power of wind speed, ranging from 10 -11 to 10 -7 fraction resuspended/sec. In another study, airborne respirable soil concentrations measured as a function of wind speed increased as the 0.6 to 3.2 power of wind speed

  5. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.L.; Su, G.F.; Chen, J.G. [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Raskob, W. [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany); Yuan, H.Y., E-mail: hy-yuan@outlook.com [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Huang, Q.Y. [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2015-10-30

    Highlights: • We integrate the iterative EnKF method into the POLYPHEMUS platform. • We thoroughly evaluate the data assimilation system against the Kincaid dataset. • The data assimilation system substantially improves the model predictions. • More than 60% of the retrieved emissions are within a factor two of actual values. • The results reveal that the boundary layer height is the key influential factor. - Abstract: Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r = 0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used.

  6. Tumoral tracers

    International Nuclear Information System (INIS)

    Camargo, E.E.

    1979-01-01

    Direct tumor tracers are subdivided in the following categories:metabolite tracers, antitumoral tracers, radioactive proteins and cations. Use of 67 Ga-citrate as a clinically important tumoral tracer is emphasized and gallium-67 whole-body scintigraphy is discussed in detail. (M.A.) [pt

  7. An experiment to use medical I-131 as tracer in a city sewer system

    Energy Technology Data Exchange (ETDEWEB)

    Ulbrich, Susanne; Fischer, Helmut W. [University of Bremen, Institute of Environmental Physics, Otto-Hahn-Allee 1, D-28359 Bremen (Germany)

    2014-07-01

    City sewer systems have to reliably carry residential and industrial wastewater to treatment plants, often mixed with rainwater. Transport in the sewer system is regularly modelled in order to predict sewerage levels, transport velocities and volume discharges. Radioisotopes would be interesting tracers, as they can be detected quickly and without the need of applying wet chemistry. Medical isotopes are released in large quantities (many MBq) by excretion from patients either at the location of administration or from elsewhere, most probably the patient's home. Depending on diagnostic or treatment modality, isotopes of different physical characteristics are used, often bound to compounds of specific metabolic behaviour. Routine environmental surveillance regularly detects the most common diagnostic ({sup 99m}Tc) and therapeutic ({sup 131}I) isotopes in city wastewater samples. Except for {sup 131}I in the case of a nuclear emergency, no contributions from sources other than medical are expected. Medical isotopes therefore might be used for tracing purposes, provided individual inputs can be identified and separated. A field experiment has been designed involving {sup 131}I releases from a single patient who had undergone radioiodine thyroid ablation therapy. This modality is applied after thyroid cancer surgery in order to destroy residual thyroid tissue. Activities up to 5 GBq of {sup 131}I are used which are excreted within few days, as no iodine-retaining thyroid tissue remains. In Germany, about 20,000 of these treatments are performed yearly. For a sewer system of 500,000 inhabitants, about 150 cases would be expected per year, making it quite improbable to have interference between individual patient releases in the same region of the city sewer system. Practically, the radiometric laboratory was informed of the expected release of an (anonymous) patient from the collaborating radiotherapy unit several days in advance, plus the approximate location of

  8. Tracer Interaction Effects During Partitioning Tracer Tests for NAPL Detection

    Science.gov (United States)

    Imhoff, P. T.; Pirestani, K.; Jafarpour, Y.; Spivey, K. M.

    2002-05-01

    Partitioning tracer tests have been used in laboratory and field investigations to quantify the amount of nonaqueous phase liquid (NAPL) within porous media. In these tests multiple chemical tracers are typically injected into flowing groundwater: conservative tracers react minimally with the NAPL, while non-conservative tracers partition into the NAPL and exhibit retarded transport. The mean travel times of the conservative and partitioning tracers can be used to estimate the NAPL saturation in the swept zone. When multiple tracers are injected in the system, the tracers themselves change the chemical composition of the NAPL, which may affect partitioning behavior. Although co-tracer interactions have been considered by others, there are no reports of such effects during actual partitioning tracer tests. In this study tracer partitioning was examined in static batch systems and dynamic column experiments using 2,3-dimethyl-2-butanol and 1-hexanol as partitioning tracers and trichloroethylene as the NAPL. Co-tracer effects resulted in nonlinear partitioning of 2,3-dimethyl-2-butanol in batch tests, which increased with increasing tracer concentrations. The UNIFAC model was used to predict tracer activities in the NAPL, and the resulting predictions of tracer partitioning matched the data trends. Column experiments were conducted with these same tracers, and nonlinear tracer partitioning associated with co-tracer effects resulted in underestimation of NAPL mass in some systems. If linear partitioning were assumed, a priori analysis suggested that nonlinear partitioning would result in an overestimation of NAPL saturation. We discuss these observations and suggest guidelines for avoiding co-tracer effects during partitioning tracer tests.

  9. Assessment of electrical conductivity as a surrogate measurement for water samples in a tracer injection experiment

    Science.gov (United States)

    The transport behavior of solutes in streams depends on chemical, physical, biological, and hydrodynamic processes. Although it is a very complex system, it is known that this behavior is greatly influenced by surface and subsurface flows. For this reason, tracer injection in the water flows is one ...

  10. Recover Act. Verification of Geothermal Tracer Methods in Highly Constrained Field Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Matthew W. [California State University, Long Beach, CA (United States)

    2014-05-16

    The prediction of the geothermal system efficiency is strong linked to the character of the flow system that connects injector and producer wells. If water flow develops channels or “short circuiting” between injection and extraction wells thermal sweep is poor and much of the reservoir is left untapped. The purpose of this project was to understand how channelized flow develops in fracture geothermal reservoirs and how it can be measured in the field. We explored two methods of assessing channelization: hydraulic connectivity tests and tracer tests. These methods were tested at a field site using two verification methods: ground penetrating radar (GPR) images of saline tracer and heat transfer measurements using distributed temperature sensing (DTS). The field site for these studies was the Altona Flat Fractured Rock Research Site located in northeastern New York State. Altona Flat Rock is an experimental site considered a geologic analog for some geothermal reservoirs given its low matrix porosity. Because soil overburden is thin, it provided unique access to saturated bedrock fractures and the ability image using GPR which does not effectively penetrate most soils. Five boreholes were drilled in a “five spot” pattern covering 100 m2 and hydraulically isolated in a single bedding plane fracture. This simple system allowed a complete characterization of the fracture. Nine small diameter boreholes were drilled from the surface to just above the fracture to allow the measurement of heat transfer between the fracture and the rock matrix. The focus of the hydraulic investigation was periodic hydraulic testing. In such tests, rather than pumping or injection in a well at a constant rate, flow is varied to produce an oscillating pressure signal. This pressure signal is sensed in other wells and the attenuation and phase lag between the source and receptor is an indication of hydraulic connection. We found that these tests were much more effective than constant

  11. Assessing groundwater availability and the response of the groundwater system to intensive exploitation in the North China Plain by analysis of long-term isotopic tracer data

    Science.gov (United States)

    Su, Chen; Cheng, Zhongshuang; Wei, Wen; Chen, Zongyu

    2018-03-01

    The use of isotope tracers as a tool for assessing aquifer responses to intensive exploitation is demonstrated and used to attain a better understanding of the sustainability of intensively exploited aquifers in the North China Plain. Eleven well sites were selected that have long-term (years 1985-2014) analysis data of isotopic tracers. The stable isotopes δ18O and δ2H and hydrochemistry were used to understand the hydrodynamic responses of the aquifer system, including unconfined and confined aquifers, to groundwater abstraction. The time series data of 14C activity were also used to assess groundwater age, thereby contributing to an understanding of groundwater sustainability and aquifer depletion. Enrichment of the heavy oxygen isotope (18O) and elevated concentrations of chloride, sulfate, and nitrate were found in groundwater abstracted from the unconfined aquifer, which suggests that intensive exploitation might induce the potential for aquifer contamination. The time series data of 14C activity showed an increase of groundwater age with exploitation of the confined parts of the aquifer system, which indicates that a larger fraction of old water has been exploited over time, and that the groundwater from the deep aquifer has been mined. The current water demand exceeds the sustainable production capabilities of the aquifer system in the North China Plain. Some measures must be taken to ensure major cuts in groundwater withdrawals from the aquifers after a long period of depletion.

  12. Determining concentration fields of tracer plumes for layered porous media in flow-tank experiments

    Science.gov (United States)

    Yu, Zhongbo; Schwartz, Franklin W.

    In the laboratory, computer-assisted image analysis provides an accurate and efficient way to monitor tracer experiments. This paper describes the determination of detailed temporal concentration distributions of tracers in a flow-tank experiment by analyzing photographs of plumes of Rhodamine dye through the glass wall of the tank. The methodology developed for this purpose consists of four steps: (1) digitally scanning black and white negatives obtained from photographs of the flow-tank experiment; (2) calibrating and normalizing each digitized image to a standard optical-density scale by determining the relation between the optical density and pixel value for each image; (3) constructing standard curves relating the concentration in an optical density from five experimental runs with predetermined concentrations (2-97mg/L) and (4) converting the optical density to concentration. The spatial distribution of concentration for two photographs was determined by applying these calibration and conversion procedures to all pixels of the digitized images. This approach provides an efficient way to study patterns of plume evolution and transport mechanisms. Résumé Au laboratoire, l'analyse d'images assistée par ordinateur est un moyen précis et efficace pour suivre certaines expériences de traçage. Ce papier présente comment sont déterminées dans le détail les distributions temporelles de la concentration en traceur au cours d'une expérience d'écoulement en réservoir au moyen de l'analyse de photographies de panaches de rhodamine à travers la paroi de verre du réservoir. La méthodologie développée dans cette expérience suit quatre étapes: (1) digitalisation par balayage des négatifs noir et blanc des prises de vue de l'expérience d'écoulement en réservoir (2) calibration et normalisation de chaque image digitalisée par rapport à une échelle étalon de densité optique en déterminant la relation entre la densité optique et la valeur des pixels

  13. Experiences of simulated tracer dispersal studies using effluent discharges at Tarapur aquatic environment

    International Nuclear Information System (INIS)

    Sudheendran, V.; Baburajan, A.; Sawane, Pratibha; Rao, D.D.; Hegde, A.G.

    2007-01-01

    The nuclear complex in Tarapur, Maharashtra is a multi facility nuclear site comprising of power reactors and research facilities. Each facility has independent liquid effluent discharge line to Arabian Sea. Experimental studies were conducted to evaluate dilution factors in the aquatic environment using liquid effluent releases as tracer from one of the facilities. 3 H and 137 Cs radioisotopes present in the routine releases were used as simulated tracer nuclides. The dilution factors(D.F) observed for tritium were in the range of 20-20000 in a distance range of 10 m to 1500 m respectively and for 137 Cs the D.F. were in the range of 50 to 900 over a distance range of 10-200 m. The paper describes the analytical methodology and sampling scenarios and the results of dilution factors obtained for Tarapur aquatic environment. (author)

  14. Estimation of Knudsen diffusion coefficients from tracer experiments conducted with a binary gas system and a porous medium.

    Science.gov (United States)

    Hibi, Yoshihiko; Kashihara, Ayumi

    2018-03-01

    A previous study has reported that Knudsen diffusion coefficients obtained by tracer experiments conducted with a binary gas system and a porous medium are consistently smaller than those obtained by permeability experiments conducted with a single-gas system and a porous medium. To date, however, that study is the only one in which tracer experiments have been conducted with a binary gas system. Therefore, to confirm this difference in Knudsen diffusion coefficients, we used a method we had developed previously to conduct tracer experiments with a binary carbon dioxide-nitrogen gas system and five porous media with permeability coefficients ranging from 10 -13 to 10 -11  m 2 . The results showed that the Knudsen diffusion coefficient of N 2 (D N2 ) (cm 2 /s) was related to the effective permeability coefficient k e (m 2 ) as D N2  = 7.39 × 10 7 k e 0.767 . Thus, the Knudsen diffusion coefficients of N 2 obtained by our tracer experiments were consistently 1/27 of those obtained by permeability experiments conducted with many porous media and air by other researchers. By using an inversion simulation to fit the advection-diffusion equation to the distribution of concentrations at observation points calculated by mathematically solving the equation, we confirmed that the method used to obtain the Knudsen diffusion coefficient in this study yielded accurate values. Moreover, because the Knudsen diffusion coefficient did not differ when columns with two different lengths, 900 and 1500 mm, were used, this column property did not influence the flow of gas in the column. The equation of the dusty gas model already includes obstruction factors for Knudsen diffusion and molecular diffusion, which relate to medium heterogeneity and tortuosity and depend only on the structure of the porous medium. Furthermore, there is no need to take account of any additional correction factor for molecular diffusion except the obstruction factor because molecular diffusion is

  15. Tracer experiments and residence-time distributions in the analysis of industrial units: case studies

    International Nuclear Information System (INIS)

    Plasari, E.; Villermaux, J.; Thereska, J.; ); Leclerc, J. P.

    1999-01-01

    The use of radioactive tracers in the analysis of industrial units is illustrated by some typical cases concerning a SO 2 - oxidation industrial reactor, a superphosphate granulator, a chromium ore rod mill, a shaft furnace and a settling tank in a copper melting processes and a fluidized bed calciner. In addition, a commercially available software package is described and the use of this package in a complicated case concerning a ventilation system is demonstrated. (author)

  16. Recommendations for the determination of migration parameters by field experiments (tracer tests)

    International Nuclear Information System (INIS)

    Adam, C.

    1989-01-01

    The hydrogeologic review and assessment of candidate sites for nuclear power plants includes expertises on the potential subsurface migration of radionuclides in the event of accident conditions. To this end, knowledge of representative migration parameters is required. Detailed recommendations are given for determining such parameters by tracer field tests, for using standardized terminology in their practical conduct as well as for interpreting the data obtained. Also, mention has been made of recent work reported by other authors on this topic. 31 refs. (author)

  17. Hydraulic and tracer experiments in the TVO research tunnel 1993- 1994

    International Nuclear Information System (INIS)

    Hautojaervi, A.; Ilvonen, M.; Vieno, T.; Viitanen, P.

    1995-04-01

    Three full-size deposition holes (diameter 1.5 m, depth 7.5 m) for spent fuel canisters in a KBS-3 type repository have been bored with a new fullface boring method in the TVO Research Tunnel. The Research Tunnel lies in the crystalline bedrock at the depth of 60 metres in the VLJ Repository for low and medium level waste. The holes are 6 metres apart. The boring tests were accompanied by comprehensive pre- and post-characterization of the rock and the bored wells. The inflow rates of groundwater in two of the three full-size holes are 6 and 20 litres/hour. The well in the middle is almost dry as expected on the basis of the pre-characterization. In the tracer tests two different tracers, a dye and a radioactive tracer, were used at the same time. The comprehensive data analysis performed showed that novel techniques (e.g. Extreme Value Estimation, EVE) can be successfully applied to determine the impulse response from the experimental results even in cases where the measured signals are disturbed. Hydraulic and tracer tests as well as visual inspection of the inflow gave clear indications of flow and transport in sparse and narrow channels. Transport velocities could be predicted with a reasonable accuracy by using a simple concept of fracture cavities determining the transport time and 'bottlenecks' causing the hydraulic resistance. The observed non-Fickian dispersion is thought to be caused by velocity differences over the channel width or by diffusion into stagnant pools in the fracture filling. (orig.) (36 refs., 67 figs., 1 tab.)

  18. [Effects of land use change on soil erosion intensity in small watershed of Loess Hilly Region: a quantitative evaluation with 137-Cesium tracer].

    Science.gov (United States)

    Wang, Ya-Feng; Fu, Bo-Jie; Li, Chen-Ding; Lü, Yi-He; Luo, Chun-Yan

    2009-07-01

    Based on the land use change data and by using 137Cs tracer technique, this paper studied the change process of soil erosion intensity in Yangjuangou watershed in Loess Hilly Region. Since the 1980's, the land use intensity in the watershed decreased gradually. In 1980-2006, the slope arable land decreased from 94.9 hm2 to 0.2 hmb2, while the forest land, shrub land, orchard land, and grassland increased from 0 to 51.1 hm2, from 0 to 19.2 hm2, from 0 to 18.0 hm2, and from 76.9 hm2 to 80.1 hmb2, respectively. The soil erosion intensity was in the order of slope arable land > shrub land > orchard land > grass land > forest land. In 1980, 1984, 1996, and 2006, the soil erosion intensity was 6408.9, 5362.4, 4903.9, and 3641.4 t x km(-2) x a(-1), respectively, being changed from intense to moderate. Soil and water conservation and vegetation restoration were the main causes of the decrease of soil erosion intensity in the study area.

  19. Phosphorous retention in a remediated stream - evaluation of a 32P tracer experiment

    Science.gov (United States)

    Riml, Joakim; Morén, Ida; Wörman, Anders

    2017-04-01

    The increased attention to surface water quality problems together with the revealed importance of the stream water -hyporheic zone system for solute retention has highlighted the potential for surface water systems to mitigate solute export to downstream recipients. As a consequence, the number of stream restoration projects during the last decades has increased significantly. However, to be able to design remediation measures as well as to assess the effectiveness of implemented measures, quantitative knowledge of the hydrodynamic (substance independent) and the biogeochemical processes (substance dependent) retaining the solute along the transport pathway is needed. In this work, we present the findings from a simultaneous injection of tritiated water (3H20) and phosphate (32PO4-) with the overall aim to evaluate the effectiveness of remediation actions implemented along a 6 km stretch of a small agricultural stream in Sweden. In contrast to many other tracer tests where different types of proxy substances are used, a key advantage of the study is the use of the substance of environmental interest (in this case phosphorous), which enhances the significance of the results. In addition, the unique radioactive signal from the injected tracer allowed us to distinguish the added phosphorous from other diffuse sources of phosphorous from the surrounding landscape. By using a physically based transport model to evaluate the tracer breakthrough curves at a number of subsequent sampling stations, we were able to contrast the response of different stream reaches both with respect to hydrodynamic and biogeochemical retention. In particular, we found a substantial importance of vegetation on the retention of 32P, when comparing established reaches with dense in-stream vegetation with newly implemented reaches where vegetation was completely absent.

  20. Emotional Intelligence in Intensive Clinical Experiences for Nursing Students

    Science.gov (United States)

    Zoromski, Lorraine M.

    2017-01-01

    This study looked for associations between measures of emotional intelligence in an intensive clinical experience for nursing students in their final semester of an associate's degree program. The theory of emotional labor was used to make connections between nursing clinical experience and emotional intelligence. Twenty nursing students from a…

  1. 26Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi.

    1990-01-01

    Accelerator mass spectrometry (AMS) was applied for 26 Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26 Al as a tracer. When 26 Al was intraperitoneally injected into rats, a considerable amount of 26 Al was incorporated into the cerebrum after 5-35 days of the injection. (author)

  2. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Sanchez, F

    2007-11-15

    /cm{sup 3}, in order to reduce the pore sizes and to better study the dynamic properties of water close to the water-clay interface. We compared the water dynamics in fully hydrated compacted clays, at two significantly different time-space scales, in an attempt to distinguish the relevant features of the water transport. A fundamental microscopic investigation, tracing down to the atomic level was carried out, by neutron scattering, using time-of-flight and backscattering techniques. A classical macroscopic study was performed by using tracer through-diffusion methods. At the macroscopic level (time/spatial scale of about hours/mm to cm) the water diffusion depends strongly on the clay pore size and arrangement of the particles. However, at the microscopic level (time/spatial scale of about ten to hundred picosecond/10{sup -8} cm) the diffusion is governed by the local environment, which concerns to cations and clay surfaces and less to the particle arrangement. For a further understanding of this local environment, the water diffusion in clays was also measured at different hydration states, to vary the fraction of interlayer or external layer water, as compared to free pore water. The large difference in the diffusion paths of the two selected techniques makes a direct comparison of water diffusivities impossible. Therefore, two possibilities were established: An indirect comparison by connecting the results for diffusion coefficient at the two different scales through pure geometrical and electrostatic factors; and a direct comparison through the activation energy E{sub a} which was estimated from the dependence of the diffusion coefficients on the temperature. In contrast to the macroscopic diffusion coefficients, the activation energy is probably less influenced by geometrical factors and more by microscopic interactions, and thus could possibly be directly compared at the two different scales. The research was accomplished by a detailed characterization of the clay

  3. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    International Nuclear Information System (INIS)

    Gonzalez Sanchez, F.

    2007-11-01

    /cm 3 , in order to reduce the pore sizes and to better study the dynamic properties of water close to the water-clay interface. We compared the water dynamics in fully hydrated compacted clays, at two significantly different time-space scales, in an attempt to distinguish the relevant features of the water transport. A fundamental microscopic investigation, tracing down to the atomic level was carried out, by neutron scattering, using time-of-flight and backscattering techniques. A classical macroscopic study was performed by using tracer through-diffusion methods. At the macroscopic level (time/spatial scale of about hours/mm to cm) the water diffusion depends strongly on the clay pore size and arrangement of the particles. However, at the microscopic level (time/spatial scale of about ten to hundred picosecond/10 -8 cm) the diffusion is governed by the local environment, which concerns to cations and clay surfaces and less to the particle arrangement. For a further understanding of this local environment, the water diffusion in clays was also measured at different hydration states, to vary the fraction of interlayer or external layer water, as compared to free pore water. The large difference in the diffusion paths of the two selected techniques makes a direct comparison of water diffusivities impossible. Therefore, two possibilities were established: An indirect comparison by connecting the results for diffusion coefficient at the two different scales through pure geometrical and electrostatic factors; and a direct comparison through the activation energy E a which was estimated from the dependence of the diffusion coefficients on the temperature. In contrast to the macroscopic diffusion coefficients, the activation energy is probably less influenced by geometrical factors and more by microscopic interactions, and thus could possibly be directly compared at the two different scales. The research was accomplished by a detailed characterization of the clay samples

  4. 68Ga-PSMA-11 PET/CT in primary staging of prostate cancer: PSA and Gleason score predict the intensity of tracer accumulation in the primary tumour.

    Science.gov (United States)

    Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Fritz, Josef; von Guggenberg, Elisabeth; Kendler, Dorota; Scarpa, Lorenza; di Santo, Gianpaolo; Roig, Llanos Geraldo; Maffey-Steffan, Johanna; Horninger, Wolfgang; Virgolini, Irene Johanna

    2017-06-01

    Prostate cancer (PC) cells typically show increased expression of prostate-specific membrane antigen (PSMA), which can be visualized by 68 Ga-PSMA-11 PET/CT. The aim of this study was to assess the intensity of 68 Ga-PSMA-11 uptake in the primary tumour and metastases in patients with biopsy-proven PC prior to therapy, and to determine whether a correlation exists between the primary tumour-related 68 Ga-PSMA-11 accumulation and the Gleason score (GS) or prostate-specific antigen (PSA) level. Ninety patients with transrectal ultrasound biopsy-proven PC (GS 6-10; median PSA: 9.7 ng/ml) referred for 68 Ga-PSMA-11 PET/CT were retrospectively analysed. PET images were analysed visually and semiquantitatively by measuring the maximum standardized uptake value (SUV max ). The SUV max of the primary tumour and pathologic lesions suspicious for lymphatic or distant metastases were then compared to the physiologic background activity of normal prostate tissue and gluteal muscle. The SUV max of the primary tumour was assessed in relation to both PSA level and GS. Eighty-two patients (91.1%) demonstrated pathologic tracer accumulation in the primary tumour that exceeded physiologic tracer uptake in normal prostate tissue (median SUV max : 12.5 vs. 3.9). Tumours with GS of 6, 7a (3+4) and 7b (4+3) showed significantly lower 68 Ga-PSMA-11 uptake, with median SUV max of 5.9, 8.3 and 8.2, respectively, compared to patients with GS >7 (median SUV max : 21.2; p PSA ≥10.0 ng/ml exhibited significantly higher uptake than those with PSA levels PSA level correlated with the intensity of tracer accumulation in the primary tumours of PC patients on 68 Ga-PSMA-11 PET/CT. As PC tumours with GS 6+7 and patients with PSA values ≤10 ng/ml showed significantly lower 68 Ga-PSMA-11 uptake, 68 Ga-PSMA-11 PET/CT should be preferentially applied for primary staging of PC in patients with GS >7 or PSA levels ≥10 ng/ml.

  5. Plume tracer experiments at Hinkley Point 'A' [Nuclear Power Station] during 1987

    International Nuclear Information System (INIS)

    Foster, P.M.

    1988-11-01

    The results of the first part of a programme of plume dispersion measurements at the Hinkley Point Nuclear Power Station are described. Using SF 6 gas and pyrotechnic smoke tracer techniques developed during an earlier study at Oldbury, measurements of ground level plume behaviour out to about 4 km and elevated plume behaviour out to about 1 km have been made in a series of twelve 1 hour trials and one 15 minute trial. Whereas the Oldbury study considered passive emissions, attention in this study has been focussed on the behaviour of the buoyant shield cooling air emission. Data on plume rise and the degree of plume entrainment by the building wake and on the effects of entrainment and wind meander on plume width and concentration, are presented and discussed in relation to current modelling recommendations. A limited number of 10 minute averaged measurements of plume concentration and 41-Ar decay gamma count were also made at 2 km range and their correlation and variability examined. (author)

  6. Tracer experiment data sets for the verification of local and meso-scale atmospheric dispersion models including topographic effects

    International Nuclear Information System (INIS)

    Sartori, E.; Schuler, W.

    1992-01-01

    Software and data for nuclear energy applications are acquired, tested and distributed by several information centres; in particular, relevant computer codes are distributed internationally by the OECD/NEA Data Bank (France) and by ESTSC and EPIC/RSIC (United States). This activity is coordinated among the centres and is extended outside the OECD area through an arrangement with the IAEA. This article proposes more specifically a scheme for acquiring, storing and distributing atmospheric tracer experiment data (ATE) required for verification of atmospheric dispersion models especially the most advanced ones including topographic effects and specific to the local and meso-scale. These well documented data sets will form a valuable complement to the set of atmospheric dispersion computer codes distributed internationally. Modellers will be able to gain confidence in the predictive power of their models or to verify their modelling skills. (au)

  7. Perceiving bodies in motion: expression intensity, empathy, and experience.

    Science.gov (United States)

    Sevdalis, Vassilis; Keller, Peter E

    2012-10-01

    This study investigated the perceptual identification of individuals' intended expression intensity in point-light displays depicting dance. Participants watched point-light displays of 200-1,000-ms duration, as well as static displays, of expressive and inexpressive dance performances. The task was to identify the intended expression intensity of the performer. The results indicate that expression intensity could be discerned reliably only from dynamic displays, even when they were as short as 200 ms, though the accuracy of judgments increased with exposure duration. Judgment accuracy for dynamic displays was positively correlated with self-report empathy indices and confidence in judgments. Accuracy for these displays also correlated with indices of informal music and dance experience. The findings are discussed in relation to sensorimotor and cognitive-emotional processes underlying action understanding and social cognition.

  8. A mathematical model for the design and interpretation of tracer experiments intended to measure the T90 in estuarine coastal waters

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2006-07-01

    In highly stratified estuarine waters, with significant sediment loads, it is fairly difficult to predict the T90 , the time scale that characterizes the bacterial inactivation or death, using mathematical formulae, so that suitable experiments must be done using tracers to measure physical dilution and microbiological methods to measure bacterial disappearance or inactivation. The location and characteristics of a second sewage out fall for the city of Montevideo is being determined. In this framework, several experiments with tracers were done to measure the self-purifying capacity of the coastal waters at the selected site. Due to the difficulties in the design and interpretation of the measurements, special mathematical models were constructed and applied to help in obtaining a deeper understanding of the complex advection-dispersion-inactivation processes. In this report the construction and the solution of the equations of an analytical model that guided all the subsequent modelling activities is described. The tracer and the bacteria fields are obtained as products of a function of time and the horizontal coordinates by a series of decaying exponential functions of time weighted by functions of depth. The quotient between the bacteria concentration and the tracer concentration, that is commonly used to determine a global value of T90 , taking suitable average values after a long enough transient, is studied. A procedure that may be used to summarize the field of local inactivation times by a few parameters, determined by tracer experiments and microbiological measurements, is discussed. A half-empirical correlation formula between the T90 parameter and the main variables of the body of receiving waters is suggested from the results of tracer experiments and other sources of information. The advantages and limitations of the modelling approach used in this case are assessed and some possible improvements are briefly outlined

  9. A mathematical model for the design and interpretation of tracer experiments intended to measure the T90 in estuarine coastal waters

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2006-03-01

    In highly stratified estuarine waters, with significant sediment loads, it is fairly difficult to predict the T90, the time scale that characterizes the bacterial inactivation or death, using mathematical formulae, so that suitable experiments must be done using tracers to measure physical dilution and microbiological methods to measure bacterial disappearance or inactivation. The location and characteristics of a second sewage outfall for the city of Montevideo is being determined. In this framework, several experiments with tracers were done to measure the self-purifying capacity of the coastal waters at the selected site. Due to the difficulties in the design and interpretation of the measurements, special mathematical models were constructed and applied to help in obtaining a deeper understanding of the complex advection-dispersion-inactivation processes. In this report the construction and the solution of the equations of an analytical model that guided all the subsequent modelling activities is described. The tracer and the bacteria fields are obtained as products of a function of time and the horizontal coordinates by a series of decaying exponential functions of time weighted by functions of depth. The quotient between the bacteria concentration and the tracer concentration, that is commonly used to determine a global value of T90 , taking suitable average values after a long enough transient, is studied. A procedure that may be used to summarize the field of local inactivation times by a few parameters, determined by tracer experiments and microbiological measurements, is discussed. A half-empirical correlation formula between the T90 parameter and the main variables of the body of receiving waters is suggested from the results of tracer experiments and other sources of information. The advantages and limitations of the modelling approach used in this case are assessed and some possible improvements are briefly outlined

  10. Atmospheric Transport Modeling with 3D Lagrangian Dispersion Codes Compared with SF6 Tracer Experiments at Regional Scale

    Directory of Open Access Journals (Sweden)

    François Van Dorpe

    2007-01-01

    Full Text Available The results of four gas tracer experiments of atmospheric dispersion on a regional scale are used for the benchmarking of two atmospheric dispersion modeling codes, MINERVE-SPRAY (CEA, and NOSTRADAMUS (IBRAE. The main topic of this comparison is to estimate the Lagrangian code capability to predict the radionuclide atmospheric transfer on a large field, in the case of risk assessment of nuclear power plant for example. For the four experiments, the results of calculations show a rather good agreement between the two codes, and the order of magnitude of the concentrations measured on the soil is predicted. Simulation is best for sampling points located ten kilometers from the source, while we note a divergence for more distant points results (difference in concentrations by a factor 2 to 5. This divergence may be explained by the fact that, for these four experiments, only one weather station (near the point source was used on a field of 10 000 km2, generating the simulation of a uniform wind field throughout the calculation domain.

  11. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  12. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    DEFF Research Database (Denmark)

    Bühring, Solveig I.; Ehrenhauss, Sandra; Kamp, Anja

    2006-01-01

    investigated the pathway of settling particulate organic carbon through the benthic food web. The diatom Ditylum brightwellii was labelled with the stable carbon isotope 13C and injected into incubation chambers. On-board incubations lasted 12, 30 and 132 h, while the in situ experiment was incubated for 32 h...

  13. Development of radioisotope tracer technology

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee; Park, Soon Chul; Lim, Dong Soon; Kim, Jae Ho; Lee, Jae Choon; Lee, Doo Sung; Cho, Yong Suk; Shin, Sung Kuan

    2000-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by proton beam and the correlation between the measured activity loss and the amount of wear was established. The equipment was developed to adjust the energy of proton which collides with the surface of tappet. The tracer project team has participated into the tracer test for estimating the efficiency of RFCC system in SK cooperation. From the experiment the tracer team has obtained the primary elements to be considered for judging the efficiency of RFCC unit. By developing the tracer techniques to test huge industrial units like RFCC, the tracer team will be able to support the local industries that require technical services to solve any urgent trouble. (author)

  14. Plume dispersion and deposition processes of tracer gas and aerosols in short-distance experiments

    International Nuclear Information System (INIS)

    Taeschner, M.; Bunnenberg, C.

    1988-01-01

    Data used in this paper were extracted from field experiments carried out in France and Canada to study the pathway of elementary tritium after possible emissions from future fusion reactors and from short-range experiments with nutrient aerosols performed in a German forest in view of a therapy of damaged coniferous trees by foliar nutrition. Comparisons of dispersion parameters evaluated from the tritium field experiments show that in the case of the 30-min release the variations of the wind directions represent the dominant mechanism of lateral plume dispersion under unstable weather conditions. This corresponds with the observation that for the short 2-min emission the plume remains more concentrated during propagation, and the small lateral dispersion parameters typical for stable conditions have to be applied. The investigations on the dispersion of aerosol plumes into a forest boundary layer show that the Gaussian plume model can be modified by a windspeed factor to be valid for predictions on aerosol concentrations and depositions even in a structured topography like a forest

  15. Expressing death risk as condensed life experience and death intensity.

    Science.gov (United States)

    Ioannidis, John P A

    2013-08-01

    Some risk exposures, including many medical and surgical procedures, typically carry hazards of death that are difficult to convey and appreciate in absolute terms. I propose presenting the death risk as a condensed life experience (i.e., the equivalent amount of life T that would carry the same cumulative mortality hazard for a person of the same age and sex based on life tables). For example, if the risk of death during an elective 1-hour procedure is 0.01%, and same-age and same-sex people have a 0.01% death risk over 1 month, one can inform the patient that "this procedure carries the same death risk as living 1 month of normal life." Comparative standards from other risky activities or from a person with the same disease at the same stage and same predictive profile could also be used. A complementary metric that may be useful to consider is the death intensity. The death intensity λ is the hazard function that shows the fold-risk estimate of dying compared with the reference person. The death intensity can vary substantially for different phases of the event, operation, or procedure (e.g., intraoperative, early postoperative, late postoperative), and this variability may also be useful to convey. T will vary depending on the time window for which it is computed. I present examples for calculating T and λ using literature data on accidents, ascent to Mount Everest, and medical and surgical procedures.

  16. Protocol number:ENANMAN25-616 abstract code:581 on numerical deconvolution for data analysis of tracers experiments

    International Nuclear Information System (INIS)

    Burgos, M. . E mail:mburgos@ucu.edu.uy; Berne, P.

    2002-01-01

    Data analysis of a tracer experiment is performed for studying the plant behavior,impact of procedures changes and several other goals.In all these cases, the observed data is the convolution of an injection function,and the systems transfer function under study.Practical discrete time convolutions may be performed multiplying a matrix of the process transfer function with the input vector,but for deconvolution it is necessary to invert the matrix which is singular in a causal system.Another method for deconvolution is by means of Fourier Transforms.Actual reading are usually corrupted by noise and besides its transforms shows high low frequencies components and high frequency ones mainly due to additive noise.Subjective decisions as cut-off frequency should be taken as well.This paper proposes a deconvolution method based on parameters fitting of suitable models,where they exist,and estimation of values where analytical forms are not available.It is based on the global, non linear fitting of them,with a criteria of maximum likelihood

  17. Application of User-Oriented MOE to Transport and Dispersion Model Predictions of the European Tracer Experiment

    National Research Council Canada - National Science Library

    Warner, Steve

    2003-01-01

    In October 1994, the tracer gas perfluoro-methyl-cyclohexane (PMCH) was released over a 12-hour period from a location in northwestern France and tracked at 168 sampling locations in 17 countries across Europe (100s of kilometers...

  18. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2008-08-01

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  19. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2010-03-16

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  20. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    International Nuclear Information System (INIS)

    Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2008-01-01

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state

  1. TRACER: an ‘eye-opener’ to the patient experience across the transition of care in an internal medicine resident program

    Directory of Open Access Journals (Sweden)

    Lauren B. Meade

    2015-04-01

    Full Text Available Background: A safe patient transition requires a complex set of physician skills within the interprofessional practice. Objective: To evaluate a rotation which applies self-reflection and workplace learning in a TRAnsition of CarE Rotation (TRACER for internal medicine (IM residents. TRACER is a 2-week required IM resident rotation where trainees join a ward team as a quality officer and follow patients into postacute care. Methods: In 2010, residents participated in semistructured, one-on-one interviews as part of ongoing program evaluation. They were asked what they had learned on TRACER, the year prior, and how they used those skills in their practice. Using transcripts, the authors reviewed and coded each transcript to develop themes. Results: Five themes emerged from a qualitative, grounded theory analysis: seeing things from the other side, the ‘ah ha’ moment of fragmented care, team collaboration including understanding nursing scope of practice in different settings, patient understanding, and passing the learning on. TRACER gives residents a moment to breathe and open their eyes to the interprofessional practice setting and the patient's experience of care in transition. Conclusions: Residents learn about transitions of care through self-reflection. This learning is sustained over time and is valued enough to teach to their junior colleagues.

  2. Families' experiences of intensive care unit quality of care

    DEFF Research Database (Denmark)

    Jensen, Hanne Irene; Gerritsen, Rik T; Koopmans, Matty

    2015-01-01

    PURPOSE: The purpose of the study is to adapt and provide preliminary validation for questionnaires evaluating families' experiences of quality of care for critically ill patients in the intensive care unit (ICU). MATERIALS AND METHODS: This study took place in 2 European ICUs. Based on literature...... and qualitative interviews, we adapted 2 previously validated North American questionnaires: "Family Satisfaction with the ICU" and "Quality of Dying and Death." Family members were asked to assess relevance and understandability of each question. Validation also included test-retest reliability and construct...... validity. RESULTS: A total of 110 family members participated. Response rate was 87%. For all questions, a median of 97% (94%-99%) was assessed as relevant, and a median of 98% (97%-100%), as understandable. Median ceiling effect was 41% (30%-47%). There was a median of 0% missing data (0%-1%). Test...

  3. Gas transport below artificial recharge ponds: insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment.

    Science.gov (United States)

    Clark, Jordan F; Hudson, G Bryant; Avisar, Dror

    2005-06-01

    A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.

  4. Anisotropy, reversibility and scale dependence of transport properties in single fracture and fractured zone - Non-sorbing tracer experiment at the Kamaishi mine

    International Nuclear Information System (INIS)

    Sawada, Atushi; Uchida, Masahiro; Shimo, Michito; Yamamoto, Hajime; Takahara, Hiroyuki; Doe, T.W.

    2001-01-01

    A comprehensive set of the non-sorbing tracer experiments were run in the granodiorite of the Kamaishi mine located in the northern part of the main island of Japan-Honshu. A detailed geo-hydraulic investigation was carried out prior to performing the tracer migration experiments. The authors conducted a detailed but simple investigation in order to understand the spatial distribution of conductive fractures and the pressure field. Seven boreholes were drilled in the test area of which dimension is approximately 80 meters by 60 meters, revealing hydraulic compartmentalization and a heterogeneous distribution of conductive features. Central three boreholes which are approx. 2 to 4 meters apart form a triangle array. After identifying two hydraulically isolated fractures and one fractured zone, a comprehensive non-sorbing tracer experiments were conducted. Four different dipole fields were used to study the heterogeneity within a fracture. Firstly, anisotropy was studied using the central borehole array of three boreholes and changing injection/withdrawal wells. Secondly, dipole ratio was varied to study how prume spread could affect the result. Thirdly, reversibility was studied by switching injection/withdrawal wells. Lastly, scale dependency was studied by using outer boreholes. The tracer breakthrough curves were analyzed by using a streamline, analytical solution and numerical analysis of mass transport. Best-fit calculations of the experimental breakthrough curves were obtained by assigning apertures within the range of 1-10 times the square root of transmissivity and a dispersion length equal to 1/10 of the migration length. Different apertures and dispersion lengths were also interpreted in anisotropy case, reversibility case and scale dependency case. Fractured zone indicated an increased aperture and increased dispersivity

  5. A Foreground Masking Strategy for [C II] Intensity Mapping Experiments Using Galaxies Selected by Stellar Mass and Redshift

    Science.gov (United States)

    Sun, G.; Moncelsi, L.; Viero, M. P.; Silva, M. B.; Bock, J.; Bradford, C. M.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A. R.; Crites, A.; Hailey-Dunsheath, S.; Uzgil, B.; Hunacek, J. R.; Zemcov, M.

    2018-04-01

    Intensity mapping provides a unique means to probe the epoch of reionization (EoR), when the neutral intergalactic medium was ionized by energetic photons emitted from the first galaxies. The [C II] 158 μm fine-structure line is typically one of the brightest emission lines of star-forming galaxies and thus a promising tracer of the global EoR star formation activity. However, [C II] intensity maps at 6 ≲ z ≲ 8 are contaminated by interloping CO rotational line emission (3 ≤ J upp ≤ 6) from lower-redshift galaxies. Here we present a strategy to remove the foreground contamination in upcoming [C II] intensity mapping experiments, guided by a model of CO emission from foreground galaxies. The model is based on empirical measurements of the mean and scatter of the total infrared luminosities of galaxies at z {10}8 {M}ȯ selected in the K-band from the COSMOS/UltraVISTA survey, which can be converted to CO line strengths. For a mock field of the Tomographic Ionized-carbon Mapping Experiment, we find that masking out the “voxels” (spectral–spatial elements) containing foreground galaxies identified using an optimized CO flux threshold results in a z-dependent criterion {m}{{K}}AB}≲ 22 (or {M}* ≳ {10}9 {M}ȯ ) at z cost of a moderate ≲8% loss of total survey volume.

  6. Data System Architectures: Recent Experiences from Data Intensive Projects

    Science.gov (United States)

    Palanisamy, G.; Frame, M. T.; Boden, T.; Devarakonda, R.; Zolly, L.; Hutchison, V.; Latysh, N.; Krassovski, M.; Killeffer, T.; Hook, L.

    2014-12-01

    U.S. Federal agencies are frequently trying to address new data intensive projects that require next generation of data system architectures. This presentation will focus on two new such architectures: USGS's Science Data Catalog (SDC) and DOE's Next Generation Ecological Experiments - Arctic Data System. The U.S. Geological Survey (USGS) developed a Science Data Catalog (data.usgs.gov) to include records describing datasets, data collections, and observational or remotely-sensed data. The system was built using service oriented architecture and allows USGS scientists and data providers to create and register their data using either a standards-based metadata creation form or simply to register their already-created metadata records with the USGS SDC Dashboard. This dashboard then compiles the harvested metadata records and sends them to the post processing and indexing service using the JSON format. The post processing service, with the help of various ontologies and other geo-spatial validation services, auto-enhances these harvested metadata records and creates a Lucene index using the Solr enterprise search platform. Ultimately, metadata is made available via the SDC search interface. DOE's Next Generation Ecological Experiments (NGEE) Arctic project deployed a data system that allows scientists to prepare, publish, archive, and distribute data from field collections, lab experiments, sensors, and simulated modal outputs. This architecture includes a metadata registration form, data uploading and sharing tool, a Digital Object Identifier (DOI) tool, a Drupal based content management tool (http://ngee-arctic.ornl.gov), and a data search and access tool based on ORNL's Mercury software (http://mercury.ornl.gov). The team also developed Web-metric tools and a data ingest service to visualize geo-spatial and temporal observations.

  7. Quantifying point source emissions with atmospheric inversions and aircraft measurements: the Aliso Canyon natural gas leak as a tracer experiment

    Science.gov (United States)

    Gourdji, S.; Yadav, V.; Karion, A.; Mueller, K. L.; Kort, E. A.; Conley, S.; Ryerson, T. B.; Nehrkorn, T.

    2017-12-01

    The ability of atmospheric inverse models to detect, spatially locate and quantify emissions from large point sources in urban domains needs improvement before inversions can be used reliably as carbon monitoring tools. In this study, we use the Aliso Canyon natural gas leak from October 2015 to February 2016 (near Los Angeles, CA) as a natural tracer experiment to assess inversion quality by comparison with published estimates of leak rates calculated using a mass balance approach (Conley et al., 2016). Fourteen dedicated flights were flown in horizontal transects downwind and throughout the duration of the leak to sample CH4 mole fractions and collect meteorological information for use in the mass-balance estimates. The same CH4 observational data were then used here in geostatistical inverse models with no prior assumptions about the leak location or emission rate and flux sensitivity matrices generated using the WRF-STILT atmospheric transport model. Transport model errors were assessed by comparing WRF-STILT wind speeds, wind direction and planetary boundary layer (PBL) height to those observed on the plane; the impact of these errors in the inversions, and the optimal inversion setup for reducing their influence was also explored. WRF-STILT provides a reasonable simulation of true atmospheric conditions on most flight dates, given the complex terrain and known difficulties in simulating atmospheric transport under such conditions. Moreover, even large (>120°) errors in wind direction were found to be tolerable in terms of spatially locating the leak rate within a 5-km radius of the actual site. Errors in the WRF-STILT wind speed (>50%) and PBL height have more negative impacts on the inversions, with too high wind speeds (typically corresponding with too low PBL heights) resulting in overestimated leak rates, and vice-versa. Coarser data averaging intervals and the use of observed wind speed errors in the model-data mismatch covariance matrix are shown to

  8. A multicomponent tracer field experiment to measure the flow volume, surface area, and rectilinear spacing of fractures away from the wellbore

    Science.gov (United States)

    Cathles, L. M.; Sanford, W. E.; Hawkins, A.; Li, Y. V.

    2017-12-01

    The nature of flow in fractured porous media is important to almost all subsurface processes including oil and gas recovery, contaminant transport and remediation, CO2 sequestration, and geothermal heat extraction. One would like to know, under flowing conditions, the flow volume, surface area, effective aperture, and rectilinear spacing of fractures in a representative volume of rock away from the well bore, but no methods currently allow acquisition of this data. It could, however, be collected by deploying inert tracers with a wide range of aqueous diffusion constants (e.g., rapidly diffusing heat to non-diffusing nanoparticle) in the following fashion: The flow volume is defined by the heated volume measured by resistivity surveys. The fracture volume within this flow volume is indicate by the nanoparticle transit time. The average fracture spacing is indicated by the evolving thermal profile in the monitor and the production wells (measured by fiber optic cable), and by the retention of absorbing tracers. The average fracture aperture is determined by permeability measurements and the average fracture separation. We have proposed a field test to redundantly measure these fracture parameters in the fractured Dakota Sandstone where it approaches the surface in Ft Collins, Colorado. Five 30 m deep wells (an injection, production, and 3 monitor wells) cased to 20 m are proposed. The experiments will involve at least 9 different tracers. The planned field test and its potential significance will be described.

  9. Experiments of an intense H{sup -} ion beam acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A.; Takeiri, Y.; Kaneko, O.; Oka, Y.; Tsumori, K.; Asano, E.; Kawamoto, T.; Akiyama, R.; Kuroda, T.

    1995-08-01

    An intense H{sup -} beam of a single beamlet is extracted from a large multicusp plasma source operated with cesium seeding. The H{sup -} beams are accelerated up to 100keV by a single-stage or a two-stage electrode system. Spatial profiles of the beams are measured calorimetrically and a minimum beam divergence angle of 5mrad is achieved at a H{sup -} current density of 30mA/cm{sup 2} with a beam energy of 100keV. A ratio of an acceleration current to a H{sup -} current increases abruptly when a H{sup -} current saturates in the space charge limited region. This enhancement is mainly due to secondary electrons caused by the intersection of H{sup -} beams with an extraction grid. When an operating gas pressure decreases, the ratio of the acceleration current to the H{sup -} current decreases. This is related to a stripping loss of H{sup -} ions in the electrodes. A beam divergence angle becomes minimum when a ratio of V{sub acc} to V{sub ext} is set at a optimum value of 1.6 in the single-stage acceleration. This ratio is almost the same as that in the double-stage acceleration, where the optimum ratio of E{sub acc1}/E{sub ext} is 1.5. In the optimum E{sub acc1}/E{sub ext} ratio the divergence angle is not affected by V{sub acc2}. The divergence angle can be reduced by changing V{sub acc2} even if the ratio of E{sub acc1}/E{sub ext} is not optimized. The beam steering effect by permanent magnets buried in an extraction grid is observed in nine beamlets experiments. A simple calculation of a single particle trajectory gives a good approximation of the beam deflection angle. (author).

  10. Bombay experience in intensive respiratory care over 6 years.

    Directory of Open Access Journals (Sweden)

    Kamat S

    1989-07-01

    Full Text Available The experience of the intensive respiratory care in 930 cases treated from 1983 for 4 years and in 404 cases over the next 2 years is reported. The background operational problems are stressed. Those between age 10 and 50 years did significantly better (p less than 0.05. The survival over the first 4 years in IPPR cases was 16.3% and in non IPPR group 71.8%; over the next 2 years, the former group, survival was 32.4 and 36.3%. The survival in asthmatic patients was high (76%. In cases with organophosphorus poisoning (without IPPR, survival was 81% while in IPPR group it was 29%. In 1988, the results in this group were better due to more aggressive management. In autopsy data on 85 cases, infection was not a major feature in those dying within 24 hours. The survival in COPD cases showed significant relation to age (p less than 0.05, initial arterial pO2 below 60 mm (p less than 0.01 and arterial pH below 7.3 (p less than 0.01. In cases with pneumonia (also asthma younger cases did better (p less than 0.05 as also those with pneumonia and initial pO2 above 60 mm (p less than 0.01 and pH above 7.3 (p less than 0.001. When pneumonia was community acquired, survival (64.8% was better than when it was hospital acquired (24%; p less than 0.01. Only the need for IPPR affected survival in trauma group. The major cause of death was infection with Klebsiella, Pseudomonas, Staphylococci and other gram--ve organisms. It is concluded that with proper planning and training, the IRCU does provide a useful mode of treatment in selected patients with respiratory problems.

  11. Meteorological tracers in regional planning

    International Nuclear Information System (INIS)

    Mueller, K.H.

    1974-11-01

    Atmospheric tracers can be used as indicators to study both the ventilation of an urban region and its dispersion meteorology for air pollutants. A correlation analysis applied to the space-time dependent tracer concentrations is able to give transfer functions, the structure and characteristic parameters of which describe the meteorological and topographical situation of the urban region and its surroundings in an integral manner. To reduce the number of persons usually involved in a tracer experiment an automatic air sampling system had to be developed

  12. Intensive care nurses' practice related to experience and shift worked.

    Science.gov (United States)

    da Silva, Rafael Celestino; Ferreira, Márcia de Assunção; Apostolidis, Thémis

    2016-06-01

    To analyse the social representations of nurses about intensive care practices comparing the variables 1) time since graduation and 2) shift worked. Qualitative field research using social representation theory. Individual interviews were conducted and lexical analysis was applied. Intensive Care Unit of a federal hospital with 21 clinical nurses. Day shift nurses are more pragmatic and operationally oriented because they deal directly with the general functioning of the unit. Less experienced nurses face difficulties dealing with intensive care contexts, but have a critical view of their practices, while more experienced nurses apply practical knowledge in their decision-making and actions. The relationship of proximity or distance from patients, mediated by technology, is related to the domains of knowledge that are required to manage technology and to the role technology plays in intensive care. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Vineyard weeds control practices impact on surface water transfers: using numerical tracer experiment coupled to a distributed hydrological model to manage agricultural practices spatial arrangements.

    Science.gov (United States)

    Colin, F.; Moussa, R.

    2009-04-01

    In rural basins, agricultural landscape management highly influences water and pollutants transfers. Landuse, agricultural practices and their spatial arrangements are at issue. Hydrological model are widely used to explore impacts of anthropogenic influences on experimental catchments. But planning all spatial arrangements leads to a possible cases count which cannot be considered. On the basis of the recent « numerical experiment » approach, we propose a « numerical tracer function » which had to be coupled to a distributed rainfall-runoff model. This function simulate the transfer of a virtual tracer successively spread on each distributed unit inside the catchment. It allows to rank hydrological spatial units according to their hydrological contribution to the surface flows, particularly at the catchment outlet. It was used with the distributed model MHYDAS in an agricultural context. The case study concerns the experimental Roujan vine-growing catchment (1km², south of France) studied since 1992. In this Mediterranean context, we focus on the soil hydraulic conductivity distributed parameter because it highly depends on weed control practices (chemical weeding induces a lot more runoff than mechanical weeding). We checked model sensitivity analysis to soil hydraulic conductivity spatial arrangement on runoff coefficient, peak discharge and catchment lag-time. Results show (i) the use of the tracer function is more efficient than a random approach to improve sensitivity to spatial arrangements from point of view of simulated discharge range, (ii) the first factor explaining hydrological simulations variability was practices area ratio, (iii) variability induced by practices spatial arrangements was significant on runoff coefficient and peak discharge for balanced practices area ratio and on lag-time for low area ratio of chemical weeding practices. From the actual situation on the experimental Roujan catchment (40% of tilled and 60% of non tilled vineyard

  14. CXTFIT/Excel-A modular adaptable code for parameter estimation, sensitivity analysis and uncertainty analysis for laboratory or field tracer experiments

    Science.gov (United States)

    Tang, Guoping; Mayes, Melanie A.; Parker, Jack C.; Jardine, Philip M.

    2010-09-01

    We implemented the widely used CXTFIT code in Excel to provide flexibility and added sensitivity and uncertainty analysis functions to improve transport parameter estimation and to facilitate model discrimination for multi-tracer experiments on structured soils. Analytical solutions for one-dimensional equilibrium and nonequilibrium convection dispersion equations were coded as VBA functions so that they could be used as ordinary math functions in Excel for forward predictions. Macros with user-friendly interfaces were developed for optimization, sensitivity analysis, uncertainty analysis, error propagation, response surface calculation, and Monte Carlo analysis. As a result, any parameter with transformations (e.g., dimensionless, log-transformed, species-dependent reactions, etc.) could be estimated with uncertainty and sensitivity quantification for multiple tracer data at multiple locations and times. Prior information and observation errors could be incorporated into the weighted nonlinear least squares method with a penalty function. Users are able to change selected parameter values and view the results via embedded graphics, resulting in a flexible tool applicable to modeling transport processes and to teaching students about parameter estimation. The code was verified by comparing to a number of benchmarks with CXTFIT 2.0. It was applied to improve parameter estimation for four typical tracer experiment data sets in the literature using multi-model evaluation and comparison. Additional examples were included to illustrate the flexibilities and advantages of CXTFIT/Excel. The VBA macros were designed for general purpose and could be used for any parameter estimation/model calibration when the forward solution is implemented in Excel. A step-by-step tutorial, example Excel files and the code are provided as supplemental material.

  15. Factors affecting experiences of intensive care patients in Turkey: patient outcomes in critical care setting.

    Science.gov (United States)

    Demir, Yurdanur; Korhan, Esra Akin; Eser, Ismet; Khorshid, Leyla

    2013-07-01

    To determine the factors affecting a patient's intensive care experience. The descriptive study was conducted at an intensive care unit in the Aegean Region of Turkey, and comprised 158 patients who spent at least 48 hours at the unit between June and November 2009. A questionnaire form and the Intensive Care Experience Scale were used as data collection tools. SPSS 11.5 was used for statistical analysis of the data. Of the total, 86 (54.4%) patients related to the surgical unit, while 72 (45.5%) spent time at the intensive care unit. Most of the subjects (n=113; 71.5%) reported that they constantly experienced pain during hospitalisation. Patients receiving mechanical ventilation support and patients reporting no pain had significantly higher scores on the intensive care experience scale. Patients who reported pain remembered their experiences less than those having no pain. Interventions are needed to make the experiences of patients in intensive care more positive.

  16. [Patients' perception of their experience in the intensive care unit].

    Science.gov (United States)

    Cazorla, Cécile; Cravoisy, Aurélie; Gibot, Sébastien; Nace, Lionel; Levy, Bruno; Bollaert, Pierre-Edouard

    2007-02-01

    To analyze patients' assessment of quality of care in our intensive care unit. We sent questionnaires to the homes of all patients admitted to intensive care from November 2002 through August 2003 who received mechanical ventilation for more than 24 hours. In all, we received 70 analyzable questionnaires. Patients' average age was 56.3 years and the mean duration of stay 13.6 days. Pain was mentioned by 47% of patients and was associated, in decreasing order of frequency, with endotracheal suctioning, placement of a urinary catheter, venipuncture, movement into a different position by staff and arterial punctures. Pain intensity evaluated by an analogic visual scale classified these procedures in the following order: endotracheal suctioning, urinary catheterization, position changing by staff, arterial punctures, venipunctures. 54% of the patients remembered mechanical ventilation. Overall, 17% reported feeling fear often or continuously. Aspects of the ICU environment that bothered them were, in order of decreasing frequency, communication difficulties, thirst, lack of sleep, staff discussions at the patient's bedside, noise and light. Finally, 34% no longer remembered the reason for their stay in the ICU and 19% reported they would have liked to be allowed more frequent visits from their relatives. Nearly half of the respondents underwent painful procedures, primarily endotracheal suctioning. One third did not know why they had been in the ICU. To improve the quality of intensive care, it is essential to make the nursing and medical teams aware of these findings.

  17. Early Seizures After Stroke: Neurology Intensive Care Unit Experience

    OpenAIRE

    Şadiye Gümüşyayla; Gönül Vural

    2018-01-01

    Objective: The aim of this study was to investigate the frequency of early seizures, the affecting factors, and the prognostic effect of seizures in patients with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), and sinus venous thrombosis (SVT) examined in the intensive care unit (ICU). Materials and Methods: In the neurology ICU, the records of patients followed up with AIS, ICH, and SVT within a defined time period were retrospectively examined. Results: Early seizures ...

  18. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, M. [University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, ON M1C 1A4 (Canada); Mitchell, C.P.J., E-mail: carl.mitchell@utoronto.ca [University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, ON M1C 1A4 (Canada); Eckley, C.S. [Meteorological Service of Canada, Environment Canada, 4905 Dufferein Street, Toronto, ON M3H 5T4 (Canada); Eggert, S.L.; Kolka, R.K.; Sebestyen, S.D. [Northern Research Station, USDA Forest Service, 1831 Hwy 169 E, Grand Rapids, MN 55744 (United States); Swain, E.B. [Minnesota Pollution Control Agency, St. Paul, MN 55155 (United States)

    2014-10-15

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil–air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m{sup −2} d{sup −1}) were significantly greater than both the traditional clearcut plot (− 40 ± 60 ng m{sup −2} d{sup −1}) and the un-harvested reference plot (− 180 ± 115 ng m{sup −2} d{sup −1}) during July. This difference was likely a result of enhanced Hg{sup 2+} photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest

  19. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Byegaard, J.; Johansson, Henrik; Skaalberg, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    1998-11-01

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na{sup +}, Rb{sup +} and Cs{sup +}) and alkaline earth metals (Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+}), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order Natracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most

  20. 15N tracer studies on N supply from different N fertilizer forms and on localization and losses of fertilizer N - pot experiment in Haplic Chernozem

    International Nuclear Information System (INIS)

    Schulz, E.

    1988-01-01

    In a pot experiment with Haplic Chernozem differing in total carbon content (Static Experiment at Lauchstaedt, 1983), studies were made into N supply from various forms of fertilizers and fertilizer N localization in the plant-soil system. In general, the percentage of fertilizer N in the total N amount taken up by maize was very high (60 to 90%). Both the variate difference method and the tracer technique identified almost equal percentages of fertilizer N in plants after application of pig urine and ammonium nitrate. However, mineralization of soil-borne N after application of sugar beet leaves was overestimated when using the variate difference method. There was no evidence of an additional mobilization of soil-borne N due to fertilization (priming effect). (author)

  1. Birth Tourism and Neonatal Intensive Care: A Children's Hospital Experience.

    Science.gov (United States)

    Mikhael, Michel; Cleary, John P; Dhar, Vijay; Chen, Yanjun; Nguyen, Danh V; Chang, Anthony C

    2016-12-01

    Objective  The aim of this article is to examine characteristics of birth tourism (BT) neonates admitted to a neonatal intensive care unit (NICU). Methods  This was a retrospective review over 3 years; BT cases were identified, and relevant perinatal, medical, social, and financial data were collected and compared with 100 randomly selected non-birth tourism neonates. Results  A total of 46 BT neonates were identified. They were more likely to be born to older women (34 vs. 29 years; p  impacts on families, health care system, and society. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. Nursing diagnosis in intensive care unit: the Turkey experience.

    Science.gov (United States)

    Korhan, Esra Akn; Yönt, Gülendam Hakverdioğlu; Erdemir, Firdevs; Müller-Staub, Maria

    2014-01-01

    The purpose of this study was to determine intensive care unit nurses diagnostic abilities and diagnoses that they provide. A vignette study was performed. The vignette contained a patient's history, treatment, and signs/symptoms of 18 nursing diagnoses based on NANDA-I as the criterion standard. Turkish intensive care unit nurses (N = 45) stated nursing diagnoses described by patient data in the vignette. The resulting nursing diagnoses were grouped into Gordon's Functional Health Patterns, and descriptive analyses were performed. One-way analysis of variance was used to detect possible differences in diagnostic abilities based on nurses' education levels. Nurses identified 14 nursing diagnoses. Four of the predetermined psychosocial nursing diagnoses were not identified. The highest percentage of diagnoses was risk for impaired skin integrity (62.2%) and impaired oral mucous membrane (60.0%). The lowest number of diagnoses was impaired verbal communication (2.2%). A statistically significant difference was found between the educational level of nurses and their abilities to determine nursing diagnoses (P < .05). The findings are important for nursing education. They demonstrate the need to focus on patients as complete human beings, covering not only biological aspects but also cultural and social values, as well as emotional and spiritual care needs.

  3. Correlating Sampling and Intensity Statistics in Nanoparticle Diffraction Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Hande [Columbia Univ., New York, NY (United States); Yan, Hanfei [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, John P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Noyan, I. Cevdet [Columbia Univ., New York, NY (United States)

    2015-08-01

    In this article, [Öztürk, Yan, Hill & Noyan (2014). J. Appl. Cryst. 47, 1016-1025] it was shown that the sampling statistics of diffracting particle populations within a polycrystalline ensemble depended on the size of the constituent crystallites: broad X-ray peak breadths enabled some nano-sized particles to contribute more than one diffraction spot to Debye-Scherrer rings. Here it is shown that the equations proposed by Alexander, Klug & Kummer [J. Appl. Phys. (1948), 19, 742-753] (AKK) to link diffracting particle and diffracted intensity statistics are not applicable if the constituent crystallites of the powder are below 10 nm. In this size range, (i) the one-to-one correspondence between diffracting particles and Laue spots assumed in the AKK analysis is not satisfied, and (ii) the crystallographic correlation between Laue spots originating from the same grain invalidates the assumption that all diffracting plane normals are randomly oriented and uncorrelated. Such correlation produces unexpected results in the selection of diffracting grains. Three or more Laue spots from a given grain for a particular reflection can only be observed at certain wavelengths. In addition, correcting the diffracted intensity values by the traditional Lorentz term, 1/cos [theta], to compensate for the variation of particles sampled within a reflection band does not maintain fidelity to the number of poles contributing to the diffracted signal. A new term, cos [theta]B/cos [theta], corrects this problem.

  4. Assessing organizational performance in intensive care units: a French experience.

    Science.gov (United States)

    Minvielle, Etienne; Aegerter, Philippe; Dervaux, Benoît; Boumendil, Ariane; Retbi, Aurélia; Jars-Guincestre, Marie Claude; Guidet, Bertrand

    2008-06-01

    The objective of the study was to assess and to explain variation of organizational performance in intensive care units (ICUs). This was a prospective multicenter study. The study involved 26 ICUs located in the Paris area, France, participating in a regional database. Data were collected through answers of 1000 ICU personnel to the Culture, Organization, and Management in Intensive Care questionnaire and from the database. Organizational performance was assessed through a composite score related to 5 dimensions: coordination and adaptation to uncertainty, communication, conflict management, organizational change, and organizational learning, Skills developed in relationship with patients and their families. Statistical comparisons between ICUs were performed by analysis of variance with a Scheffé pairwise procedure. A multilevel regression model was used to analyze both individual and structural variables explaining differences of ICU's organizational performance. The organizational performance score differed among ICUs. Some cultural values were negatively correlated with a high level of organizational performance, suggesting improvement potential. Several individual and structural factors were also related to the quality of ICU organization, including absence of burnout, older staff, satisfaction to work, and high workload (P managers to assess the organizational performance of their ICU based on a validated questionnaire. Differences are mainly explained by cultural values and individual well-being factors, introducing new requirements for managing human resources in ICUs.

  5. Intensity Improvement For AD Experiments Using Barrier Bucket Cooling

    CERN Document Server

    Bojtár, L

    2009-01-01

    We propose to cool the antiproton beam confined into a 300 ns or shorter barrier bucket. The longitudinal emittance obtained this way is much smaller than it is possible with coasting beam cooling. This allows beam bunching already in the AD ring with 202.56 MHz, the frequency of the ASACUSA RFQD. The proposed scheme requires the installation of two 202.56 MHz cavities and a barrier bucket cavity into the ring. With this modest investment ASACUSA gains a factor 2-3 in intensity. A proof of principle test has been done during 3 MD sessions recently. The beam emittances in all planes were measured after the beam was cooled in the barrier bucket and were found sufficiently low.

  6. Measurement of glucose and 2-deoxy-2-[18F]fluoro-D-glucose transport and phosphorylation rates in myocardium using dual-tracer kinetic experiments

    International Nuclear Information System (INIS)

    Huang, S.C.; Williams, B.A.; Barrio, J.R.; Nissenson, C.; Hoffman, E.J.; Phelps, M.E.; Krivokapich, J.

    1987-01-01

    To examine the use of 2-deoxy-2-[ 18 F]fluoro-D-glucose (2-FDG) as a glucose analog for measuring glucose utilization rate in myocardium, dual-tracer kinetic experiments with 2-FDG and 2-[ 3 H]glucose were performed in the perfused, isolated rabbit interventricular septum to measure simultaneously the transport and phosphorylation rates of glucose and 2-FDG. Results of the present study indicated that, in the septum, (i) the transport rate constants of 2-FDG and glucose were similar in magnitude, (ii) the phosphorylation rate constant for 2-FDG was about 60% of that of glucose, (iii) hypoxia caused an increase in phosphorylation rates of glucose and 2-FDG without affecting transport. 9 refs.; 1 figure; 3 tabs

  7. Early Seizures After Stroke: Neurology Intensive Care Unit Experience

    Directory of Open Access Journals (Sweden)

    Şadiye Gümüşyayla

    2018-03-01

    Full Text Available Objective: The aim of this study was to investigate the frequency of early seizures, the affecting factors, and the prognostic effect of seizures in patients with acute ischemic stroke (AIS, intracerebral hemorrhage (ICH, and sinus venous thrombosis (SVT examined in the intensive care unit (ICU. Materials and Methods: In the neurology ICU, the records of patients followed up with AIS, ICH, and SVT within a defined time period were retrospectively examined. Results: Early seizures occurred in 48 out of 199 patients who were followed up with AIS, ICH, and SVT in the neurology ICU within the specified time period. The frequency of having early seizures was found to be higher in patients with left hemisphere lesions, cortical lesions, and those with AIS with hemorrhagic transformation. Lesion volume was found to be higher in patients with AIS who had early seizures compared with those who had AIS without seizures. Early seizures were observed in all patients with SVT who were followed up in the ICU. Conclusion: Early seizures are a common complication in patients with stroke followed up in neurology ICUs. Determination of effective factors in early seizures is important for its early diagnosis and treatment

  8. Dispersion and Travel Time of Dissolved and Floating Tracers in Urban Sewers

    Directory of Open Access Journals (Sweden)

    Istók Balázs

    2014-03-01

    Full Text Available Environmental impacts of oil spills affecting urban sewage networks can be eliminated if timely intervention is taken. The design of such actions requires knowledge of the transport of surface pollutants in open channels. In this study we investigated the travel time and dispersion of pollutants by means of tracer experiments in sewage networks and a creek. The travel time of surface tracers has been found to be significantly shorter than that of a bulk flow tracer. The ratio of the travel times of a bulk flow tracer and surface tracers agreed with the known correlations obtained for rivers. An increasing tendency in the ratio of travel times has been observed for increasing bulk flow velocity. A segment-wise dispersion model was implemented in the existing hydraulic model of a sewer system. The simulation results were compared with the experimental observations. The dispersion rate of the bulk flow tracer has been found to obey Taylor’s mixing theory for long channels and was more intensive than that of surface tracers in community sewage channels.

  9. Characterizing Mobile/Less-Mobile Porosity and Solute Exchange in Dual-Domain Media Using Tracer Experiments and Electrical Measurements in a Hassler-Type Core Holder

    Science.gov (United States)

    Falzone, S.; Slater, L. D.; Day-Lewis, F. D.; Parker, B. L.; Keating, K.; Robinson, J.

    2017-12-01

    Mass transfer is the process by which solute is retained in less-mobile porosity domains, and later released into the mobile porosity domain. This process is often responsible for the slow arrival and gradual release of contaminants and solute tracers. Recent studies have outlined methods using dual-domain mass transfer (DDMT) models for characterizing this phenomenon. These models use the non-linear relationship of bulk (σb) and fluid (σf) conductivity, collected from electrical methods during tracer experiments, to characterize the less-mobile/mobile porosity ratio (β) and the mass-transfer rate coefficient (α). DDMT models use the hysteretic σb-σf relationship observed while solute tracers are injected and then flushed from a sample media. Due to limitations in observing the hysteretic σb-σf relationship, this method has not been used to characterize low permeability samples. We have developed an experimental method for testing porous rock cores that allows us to develop a fundamental understanding of contaminant storage and release in consolidated rock. We test the approach on cores from sedimentary rock sites where mass transfer is expected to occur between hydraulically connected fractures and the adjacent low permeability rock matrix. Our method uses a Hassler-type core holder, designed to apply confining pressure around the outside of a sample core, which hydraulically isolates the sample core, allowing water to be injected into it at increased pressures. The experimental apparatus was also designed to measure σb with spectral induced polarization (SIP) measurements, and σf from a sampling port located at the center of the core. Cores were initially saturated with a solution with high electrical conductivity ( 80000 μS/cm). DI water was then injected into the cores at elevated pressures (>60 psi) and the saturating solution was flushed from the cores, in order to generate flow rates fast enough to capture the non-linear σb-σf relationship

  10. Fiber-optical sensor with intensity compensation model in college teaching of physics experiment

    Science.gov (United States)

    Su, Liping; Zhang, Yang; Li, Kun; Zhang, Yu

    2017-08-01

    Optical fiber sensor technology is one of the main contents of modern information technology, which has a very important position in modern science and technology. Fiber optic sensor experiment can improve students' enthusiasm and broaden their horizons in college physics experiment. In this paper the main structure and working principle of fiberoptical sensor with intensity compensation model are introduced. And thus fiber-optical sensor with intensity compensation model is applied to measure micro displacement of Young's modulus measurement experiment and metal linear expansion coefficient measurement experiment in the college physics experiment. Results indicate that the measurement accuracy of micro displacement is higher than that of the traditional methods using fiber-optical sensor with intensity compensation model. Meanwhile this measurement method makes the students understand on the optical fiber, sensor and nature of micro displacement measurement method and makes each experiment strengthen relationship and compatibility, which provides a new idea for the reform of experimental teaching.

  11. The Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) Experiment Overview: Binational Dye Tracer Releases to Study Pollution Transport and Dilution.

    Science.gov (United States)

    Feddersen, F.; Giddings, S. N.; Kumar, N.; Grimes, D. J.; Pawlak, G. R.; Rivas, D.; Diaz, M.

    2016-02-01

    Per square km, the surfzone and inner-shelf are by far the most economically and ecologically important ocean regions, vital for recreation, food, and ecosystem services. Despite the importance of clean coastal waters to our economy and well-being, declining water quality threatens coastal ecosystem and human health worldwide. Healthy coasts are a significant priority to federal agencies, local government, and NGOs. In particular the San Diego US and Tijuana Mexico border region have unique and persistent water quality issues due to a range of pollution sources. Cross-shore exchange of tracers (e.g., pathogens, anthropogenic nutrients, harmful algal blooms - HABs, larvae) between the well-mixed surfzone and stratified inner-shelf is poorly understood. The surfzone, inner- and mid-shelf span drastically different dynamical regimes, with varying cross-shelf exchange mechanisms due to wave, wind, buoyancy, and tidal processes and intrinsic variability. The NSF funded CSIDE (Cross Surfzone/Inner-shelf Dye Exchange) experiment (Sept & Oct 2015) aims to increase our understanding of cross-shelf material exchange by performing 3 shoreline dye release experiments that are tracked for up to 20 km alongshore and over 48+ hrs. One dye release will be performed in Mexico and the dye transport tracked across the border. The dye will be tracked via a broad range of binational instrumentation. In this presentation, we present an overview of the CSIDE experiment, in particular the binational aspects of the study,

  12. Systematic review of qualitative studies exploring parental experiences in the Neonatal Intensive Care Unit.

    Science.gov (United States)

    Al Maghaireh, Dua'a Fayiz; Abdullah, Khatijah Lim; Chan, Chong Mei; Piaw, Chua Yan; Al Kawafha, Mariam Mofleh

    2016-10-01

    To determine the feasibility and utility of a thematic analysis approach to synthesising qualitative evidence about parental experiences in the neonatal intensive care unit. Admission of infants to the neonatal intensive care unit is usually an unexpected event for parents who can cause them to experience psychosocial difficulties. A qualitative systematic review is the best method for exploring these parents' experiences regarding this type of admission. Systematic review. Qualitative studies in peer-reviewed journals aimed at understanding parental experiences regarding infant neonatal intensive care unit admission were identified in six electronic databases. Three reviewers selected relevant articles and assessed the quality of the methodological studies using the Critical Appraisal Skills Programme. A thematic analysis approach was used to identify the most common themes in the studies describing parental experiences in the neonatal intensive care unit. A total of eighty articles were identified; nine studies were included in this review. Four studies used semistructured interviews, three used interviews, one used self-reporting and one used both focus group and interview methodologies. Common themes across parents' experiences were the stress of hospitalisation, alteration in parenting roles and the impact of infant hospitalisation on psychological health. Having an infant hospitalised in the neonatal intensive care unit is a stressful experience for parents. This experience is the result of exposure to different stressors related to the infant's condition, an alteration in parenting roles or the neonatal intensive care unit environment and staffing. These parents suffered negative psychological effects, experienced an interrupted development of a healthy parent-infant attachment and/or felt parental role alteration. The study's findings are crucial for neonatal intensive care unit nurses to develop intervention strategies and programmes that help parents to

  13. Cluster analysis of DCE-MRI data identifies regional tracer-kinetic changes after tumor treatment with high intensity focused ultrasound

    NARCIS (Netherlands)

    Jacobs, Igor; Hectors, Stefanie J. C. G.; Schabel, Matthias C.; Grüll, Holger; Strijkers, Gustav J.; Nicolay, Klaas

    2015-01-01

    Evaluation of high intensity focused ultrasound (HIFU) treatment with MRI is generally based on assessment of the non-perfused volume from contrast-enhanced T1-weighted images. However, the vascular status of tissue surrounding the non-perfused volume has not been extensively investigated with MRI.

  14. R & D of a Gas-Filled RF Beam Profile Monitor for Intense Neutrino Beam Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yonehara, K. [Fermilab; Backfish, M. [Fermilab; Moretti, A. [Fermilab; Tollestrup, A. V. [Fermilab; Watts, A. [Fermilab; Zwaska, R. M. [Fermilab; Abrams, R. [MUONS Inc., Batavia; Cummings, M. A.; Dudas, A. [MUONS Inc., Batavia; Johnson, R. P. [MUONS Inc., Batavia; Kazakevich, G. [MUONS Inc., Batavia; Neubauer, M. [MUONS Inc., Batavia; Liu, Q. [Case Western Reserve U.

    2017-05-01

    We report the R&D of a novel radiation-robust hadron beam profile monitor based on a gas-filled RF cavity for intense neutrino beam experiments. An equivalent RF circuit model was made and simulated to optimize the RF parameter in a wide beam intensity range. As a result, the maximum acceptable beam intensity in the monitor is significantly increased by using a low-quality factor RF cavity. The plan for the demonstration test is set up to prepare for future neutrino beam experiments.

  15. ESR signal intensity of quartz in the fine-silt fraction of riverbed sediments from the Yangtze River: a provenance tracer for suspended particulate matter

    Science.gov (United States)

    Saito, Keita; Tada, Ryuji; Zheng, Hongbo; Irino, Tomohisa; Luo, Chao; He, Mengying; Wang, Ke; Suzuki, Yoshiaki

    2017-12-01

    The Asian summer monsoon exerts a strong influence on the hydrologic cycle in East Asia. Moreover, the distribution of heavy precipitation in the Yangtze River basin, which covers a large area of South China, is sensitive to changes in monsoon intensity. Thus, the paleo-distribution of heavy precipitation in the Yangtze basin is key in reconstructing the paleo-monsoon intensity. In this study, we established proxies for distinguishing sediments from the northwestern and southeastern parts of the Yangtze River basin, with the goal of using them to reconstruct the paleo-distribution of heavy precipitation in the basin based on changes in the provenance of detrital sediments, as determined using sediment records at the river mouth. The proxies included the electron spin resonance (ESR) signal intensity and the crystallinity index (CI) of quartz in modern riverbed sediments along the mainstream and tributaries of the Yangtze River. The data revealed that the fine-silt fraction of the sediments (which represents suspended particulate matter, SPM) from each major tributary can be distinguished on the basis of ESR signal intensity and CI values. The values for each tributary reflect the age and type of bedrock in the tributary basin and show distinct regional variations according to the distribution of geological blocks within the Yangtze basin. In addition, the analyzed ESR signal intensity and CI values of the fine-silt fraction of riverbed sediments below mainstream-tributary junctions agree well with values calculated according to a simple mixing model of SPM discharged from the tributaries and the mainstream.

  16. Streamwise decrease of the 'unsteady' virtual velocity of gravel tracers

    Science.gov (United States)

    Klösch, Mario; Gmeiner, Philipp; Habersack, Helmut

    2017-04-01

    Gravel tracers are usually inserted and transported on top of the riverbed, before they disperse vertically and laterally due to periods of intense bedload, the passage of bed forms, lateral channel migration and storage on bars. Buried grains have a lower probability of entrainment, resulting in a reduction of overall mobility, and, on average, in a deceleration of the particles with distance downstream. As a consequence, the results derived from tracer experiments and their significance for gravel transport may depend on the time scale of the investigation period, complicating the comparison of results from different experiments. We developed a regression method, which establishes a direct link between the transport velocity and the unsteady flow variables to yield an 'unsteady' virtual velocity, while considering the tracer slowdown with distance downstream in the regression. For that purpose, the two parameters of a linear excess shear velocity formula (the critical shear velocity u*c and coefficient a) were defined as functions of the travelled distance since the tracer's insertion. Application to published RFID tracer data from the Mameyes River, Puerto Rico, showed that during the investigation period the critical shear velocity u*c of tracers representing the median bed particle diameter (0.11 m) increased from 0.36 m s-1 to 0.44 m s-1, while the coefficient a decreased from the dimensionless value of 4.22 to 3.53, suggesting a reduction of the unsteady virtual velocity at the highest shear velocity in the investigation period from 0.40 m s-1 to 0.08 m s-1. Consideration of the tracer slowdown improved the root mean square error of the calculated mean displacements of the median bed particle diameter from 8.82 m to 0.34 m. As in previous work these results suggest the need of considering the history of transport when deriving travel distances and travel velocities, depending on the aim of the tracer study. The introduced method now allows estimating the

  17. The experience of intensive care nurses caring for patients with delirium: A phenomenological study.

    Science.gov (United States)

    LeBlanc, Allana; Bourbonnais, Frances Fothergill; Harrison, Denise; Tousignant, Kelly

    2018-02-01

    The purpose of this research was to seek to understand the lived experience of intensive care nurses caring for patients with delirium. The objectives of this inquiry were: 1) To examine intensive care nurses' experiences of caring for adult patients with delirium; 2) To identify factors that facilitate or hinder intensive care nurses caring for these patients. This study utilised an interpretive phenomenological approach as described by van Manen. Individual conversational interviews were conducted with eight intensive care nurses working in a tertiary level, university-affiliated hospital in Canada. The essence of the experience of nurses caring for patients with delirium in intensive care was revealed to be finding a way to help them come through it. Six main themes emerged: It's Exhausting; Making a Picture of the Patient's Mental Status; Keeping Patients Safe: It's aReally Big Job; Everyone Is Unique; Riding It Out With Families and Taking Every Experience With You. The findings contribute to an understanding of how intensive care nurses help patients and their families through this complex and distressing experience. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Quadratic tracer dynamical models tobacco growth

    International Nuclear Information System (INIS)

    Qiang Jiyi; Hua Cuncai; Wang Shaohua

    2011-01-01

    In order to study the non-uniformly transferring process of some tracer dosages, we assume that the absorption of some tracer by tobacco is a quadratic function of the tracer quantity of the tracer in the case of fast absorption, whereas the exclusion of the tracer from tobacco is a linear function of the tracer quantity in the case of slow exclusion, after the tracer is introduced into tobacco once at zero time. A single-compartment quadratic dynamical model of Logistic type is established for the leaves of tobacco. Then, a two-compartment quadratic dynamical model is established for leaves and calms of the tobacco. Qualitative analysis of the models shows that the tracer applied to the leaves of the tobacco is excluded finally; however, the tracer stays at the tobacco for finite time. Two methods are also given for computing the parameters in the models. Finally, the results of the models are verified by the 32 P experiment for the absorption of tobacco. (authors)

  19. Synoptic tracer gradients in the upper troposphere over central Canada during the Stratosphere-Troposphere Experiments by Aircraft Measurements 1998 summer campaign

    NARCIS (Netherlands)

    Fischer, H.; Brunner, D; Harris, GW; Hoor, P; Lelieveld, J; McKenna, DS; Rudolph, J; Scheeren, HA; Siegmund, P; Wernli, H; Williams, J; Wong, S

    [1] During the July 1998 Stratosphere-Troposphere Experiments by Aircraft Measurements (STREAM) intensive campaign, eight measurement flights were conducted from Timmins airport (Ontario, Canada, 48.2degreesN, 79.3degreesW). In situ measurements of ozone, carbon monoxide, carbon dioxide, and

  20. {sup 68}Ga-PSMA-11 PET/CT in primary staging of prostate cancer: PSA and Gleason score predict the intensity of tracer accumulation in the primary tumour

    Energy Technology Data Exchange (ETDEWEB)

    Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Guggenberg, Elisabeth von; Kendler, Dorota; Scarpa, Lorenza; Di Santo, Gianpaolo; Roig, Llanos Geraldo; Maffey-Steffan, Johanna; Virgolini, Irene Johanna [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Fritz, Josef [Medical University Innsbruck, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Horninger, Wolfgang [Medical University Innsbruck, Department of Urology, Innsbruck (Austria)

    2017-06-15

    Prostate cancer (PC) cells typically show increased expression of prostate-specific membrane antigen (PSMA), which can be visualized by {sup 68}Ga-PSMA-11 PET/CT. The aim of this study was to assess the intensity of {sup 68}Ga-PSMA-11 uptake in the primary tumour and metastases in patients with biopsy-proven PC prior to therapy, and to determine whether a correlation exists between the primary tumour-related {sup 68}Ga-PSMA-11 accumulation and the Gleason score (GS) or prostate-specific antigen (PSA) level. Ninety patients with transrectal ultrasound biopsy-proven PC (GS 6-10; median PSA: 9.7 ng/ml) referred for {sup 68}Ga-PSMA-11 PET/CT were retrospectively analysed. PET images were analysed visually and semiquantitatively by measuring the maximum standardized uptake value (SUV{sub max}). The SUV{sub max} of the primary tumour and pathologic lesions suspicious for lymphatic or distant metastases were then compared to the physiologic background activity of normal prostate tissue and gluteal muscle. The SUV{sub max} of the primary tumour was assessed in relation to both PSA level and GS. Eighty-two patients (91.1%) demonstrated pathologic tracer accumulation in the primary tumour that exceeded physiologic tracer uptake in normal prostate tissue (median SUV{sub max}: 12.5 vs. 3.9). Tumours with GS of 6, 7a (3+4) and 7b (4+3) showed significantly lower {sup 68}Ga-PSMA-11 uptake, with median SUV{sub max} of 5.9, 8.3 and 8.2, respectively, compared to patients with GS >7 (median SUV{sub max}: 21.2; p < 0.001). PC patients with PSA ≥10.0 ng/ml exhibited significantly higher uptake than those with PSA levels <10.0 ng/ml (median SUV{sub max}: 17.6 versus 7.7; p < 0.001). In 24 patients (26.7%), 82 lymph nodes with pathologic tracer accumulation consistent with metastases were detected (median SUV{sub max}: 10.6). Eleven patients (12.2%) revealed 55 pathologic osseous lesions suspicious for bone metastases (median SUV{sub max}: 11.6). The GS and PSA level correlated with

  1. One-Dimensional Modeling of Bromide Tracer and Trichloroethylene Transport Based on Laboratory Experiments in Vertical Soil Columns

    OpenAIRE

    Murch, Keri L.

    2003-01-01

    Enhanced biodegradation using carbon donor and microbial addition is being considered as a possible remediation technique for a trichloroethylene (TCE) contaminated area in Sunset, Utah, west of the source area on Hill Air Force Base. As a precursor to any in situ remediation attempts, several laboratory treatability experiments are being conducted, including the construction of microcosms and flow-through columns. Nine large-scale flow-through columns were built using site groundwater and aq...

  2. Hospitalization of a child in the Neonatal Intensive Care – parents’ experiences

    Directory of Open Access Journals (Sweden)

    Kopeć Agnieszka

    2016-03-01

    Full Text Available Introduction. Significant progress in the perinatal and intensive care therapy resulted in a meaningful increase of survival of extremely immature, and burdened with severe diseases neonates. Although infants are the patients of the Neonatal Intensive Care Unit, the needs of their parents should also be noticed and realized. The aim of the study was the analysis of the parents’ experiences of children hospitalized in the NICU.

  3. Theory of Oxygen Tracer Diffusion Along Grain Boundaries and in the Bulk in Two-Stage Oxidation Experiments. Part III: Monte-Carlo Simulations

    Science.gov (United States)

    Mishin, Yuri; Schimmelpfennig, Jörg; Borchardt, Günter

    1997-09-01

    In Parts I and II of this work we developed a model of oxygen ^{18}O tracer diffusion in a growing polycrystalline oxide film with parallel grain boundaries. In this paper we solve the basic equations of the model numerically using the Monte-Carlo approach. We introduce a new simulation technique that takes into account the finite-size effect, the film growth, the effect of the oxygen chemical potential gradient across the film, and other factors. We apply this technique for the simulation of the most important cases encountered in two-stage oxidation experiments. The oxygen tracer profiles obtained demonstrate good agreement with the previous theoretical analysis, the finite-difference solution of the problem, and exact analytical solutions when available. We discuss possible extensions of the simulation method to provide a more realistic description of the oxide growth. Dans la partie I et II de ces travaux, nous avons développé un modèle pour la diffusion du traceur ^{18}O dans un film d'oxyde croissant avec des joints de grains parallèles. Dans cet article, nous donnons une solution numérique des équations fondamentales par la méthode de Monte-Carlo. Nous introduisons une nouvelle méthode de simulation qui tient compte de la géométrie de couches minces, du gradient du potentiel chimique de l'oxygène à travers la couche et d'autres paramètres. Nous utilisons cette technique afin de simuler les cas les plus fréquement rencontés dans des expériences d'oxydation à deux étapes. Les profils de traceurs obtenus sont en bon accord avec l'analyse théorique antérieur, avec les profils calculés par la méthode des différences finies et, s'il y en a, avec des solutions analytiques. Nous discutons l'extension éventuelle de notre méthode de simulation afin de fournir une description plus réaliste de la croissance d'une couche d'oxyde.

  4. Benchmarking numerical codes for tracer transport with the aid of laboratory-scale experiments in 2D heterogeneous porous media.

    Science.gov (United States)

    Maina, Fadji Hassane; Ackerer, Philippe; Younes, Anis; Guadagnini, Alberto; Berkowitz, Brian

    2017-06-07

    We present a combined experimental and numerical modeling study that addresses two principal questions: (i) is any particular Eulerian-based method used to solve the classical advection-dispersion equation (ADE) clearly superior (relative to the others), in terms of yielding solutions that reproduce BTCs of the kind that are typically sampled at the outlet of a laboratory cell? and (ii) in the presence of matches of comparable quality against such BTCs, do any of these methods render different (or similar) numerical BTCs at locations within the domain? To address these questions, we obtained measurements from carefully controlled laboratory experiments, and employ them as a reference against which numerical results are benchmarked and compared. The experiments measure solute transport breakthrough curves (BTCs) through a square domain containing various configurations of coarse, medium, and fine quartz sand. The approaches to solve the ADE involve Eulerian-Lagrangian and Eulerian (finite volume, finite elements, mixed and discontinuous finite elements) numerical methods. Model calibration is not examined; permeability and porosity of each sand were determined previously through separate, standard laboratory tests, while dispersivities are assigned values proportional to mean grain size. We find that the spatial discretization of the flow field is of critical importance, due to the non-uniformity of the domain. Although simulated BTCs at the system outlet are observed to be very similar for these various numerical methods, computed local (point-wise, inside the domain) BTCs can be very different. We find that none of the numerical methods is able to fully reproduce the measured BTCs. The impact of model parameter uncertainty on the calculated BTCs is characterized through a set of numerical Monte Carlo simulations; in cases where the impact is significant, assessment of simulation matches to the experimental data can be ambiguous. Copyright © 2017 Elsevier B.V. All

  5. Home to die from the intensive care unit: A qualitative descriptive study of the family's experience.

    Science.gov (United States)

    Hutchinson, Amy L; Van Wissen, Kim A

    2017-12-01

    Many people would choose to die at home, and this can be an option for intensive care patients. However, there is limited exploration of the impact on the family. To gain insight into family members' experiences when an adult intensive care unit patient is taken home to die. Methodology is qualitative description, utilising purposeful sampling, unstructured interviews and thematic analysis. Four participants, from two different families were interviewed. The setting was a tertiary level Intensive Care Unit in New Zealand. The experience was described as a kaleidoscope of events with two main themes: 'value' family member's found in the patient going home, and their experience of the 'process'. 'Value' subthemes: going home being the patient's own decision, home as an end-of-life environment, and the patient's positive response to being at home. 'Process' subthemes: care and support received, stress of a family member being in intensive care, feeling that everything happened quickly, and concerns and uncertainties. Going home to die from the intensive care unit can be a positive but challenging experience for the family. Full collaboration between the patient, family and staff is essential, to ensure the family are appropriately supported. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Environmental Tax Reforms and Mitigation for Energy-intensive Industries: Some Lessons from European Experience

    DEFF Research Database (Denmark)

    Andersen, Mikael Skou

    2009-01-01

    The purpose of this paper is to analyse in more detail the international experiences in applying carbon-energy taxation in two important energy-intensive sectors; iron and steel, as well as non-metallic mineral products (where cement is the most significant subsector).......The purpose of this paper is to analyse in more detail the international experiences in applying carbon-energy taxation in two important energy-intensive sectors; iron and steel, as well as non-metallic mineral products (where cement is the most significant subsector)....

  7. Biological tracer method

    Science.gov (United States)

    Strong-Gunderson, Janet M.; Palumbo, Anthony V.

    1998-01-01

    The present invention is a biological tracer method for characterizing the movement of a material through a medium, comprising the steps of: introducing a biological tracer comprising a microorganism having ice nucleating activity into a medium; collecting at least one sample of the medium from a point removed from the introduction point; and analyzing the sample for the presence of the biological tracer. The present invention is also a method for using a biological tracer as a label for material identification by introducing a biological tracer having ice nucleating activity into a material, collecting a sample of a portion of the labelled material and analyzing the sample for the presence of the biological tracer.

  8. Intensive care unit patients' experience of being conscious during endotracheal intubation and mechanical ventilation.

    Science.gov (United States)

    Holm, Anna; Dreyer, Pia

    2017-03-01

    There is a change in paradigm in intensive care units with trends towards lighter sedation. Light or no sedation protocols are, however, a radical change for clinical practice and can cause challenges for the patients. Undergoing mechanical ventilation when conscious can be a distressing experience for the patients. Receiving a tracheostomy increases patient comfort, but some patients still undergo prolonged endotracheal intubation during mechanical ventilation. The experience of being conscious during endotracheal intubation and mechanical ventilation in the intensive care unit has not previously been described. The aim of the study was to explore adult intensive care unit patients' experience of being conscious during endotracheal intubation and mechanical ventilation. Data collection was performed through semi-structured interviews and four patients were enrolled. Data were collected at two multidisciplinary intensive care units in Denmark. Data were analysed using Ricoeur's theory of interpretation, using the method described by Dreyer and Pedersen. The scientific tradition was phenomenological-hermeneutic. During the analysis, three themes emerged: (1) The tube in the throat. (2) To be conscious but feeling doped. (3) When passing of time is dragging on. The findings shed a light over the experience of being conscious during endotracheal intubation and mechanical ventilation in the intensive care unit. A no-sedation protocol may cause problems for the patients both of a physical and an existential character, but despite this, patients seem positive towards being conscious. The study suggests that clinical nursing practice may have to be further developed to accommodate the patients' needs, e.g. communicating and participating as well as optimizing nursing interventions towards thirst, pain and tube management. Furthermore, the intensive care unit setting may need revision, providing space for the patient and sensory meaningful inputs in the technologically

  9. Tracer filamentation at an unstable ocean front

    Science.gov (United States)

    Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

    2017-11-01

    A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

  10. Evidence for substantial forestry canopy processing of nitrogen deposition using isotopic tracer experiments in low deposition conditions

    Science.gov (United States)

    Ferraretto, Daniele; Heal, Kate

    2017-04-01

    Temperate forest ecosystems are significant sinks for nitrogen deposition (Ndep) yielding benefits such as protection of waterbodies from eutrophication and enhanced sequestration of atmospheric CO2. Previous studies have shown evidence of biological nitrification and Ndep processing and retention in forest canopies. However, this was reported only at sites with high environmental or experimentally enhanced rates of Ndep (˜18 kg N ha-1 y-1) and has not yet been demonstrated in low Ndep environments. We have used bulk field hydrochemical measurements and labelled isotopic experiments to assess canopy processing in a lower Ndep environment (˜7 kg N ha-1 year-1) at a Sitka spruce plantation in Perthshire, Scotland, representing the dominant tree species (24%) in woodlands in Great Britain. Analysis of 4.5 years of measured N fluxes in rainfall (RF) and fogwater onto the canopy and throughfall (TF) and stemflow (SF) below the canopy suggests strong transformation and uptake of Ndep in the forest canopy. Annual canopy Ndep uptake was ˜4.7 kg N ha-1 year-1, representing 60-76% of annual Ndep. To validate these plot-scale results and track N uptake within the forest canopy in different seasons, double 15N-labelled NH4NO3 (98%) solution was sprayed in summer and winter onto the canopy of three trees at the measurement site. RF, TF and SF samples have been collected and analysed for 15NH4 and 15NO3. Comparing the amount of labelled N recovered under the sample trees with the measured δ15N signal is expected to provide further evidence of the role of forest canopies in actively processing and retaining atmospheric N deposition.

  11. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  12. Simulation of a field scale tritium tracer experiment in a fractured, weathered shale using discrete-fracture/matrix-diffusion and equivalent porous medium models

    International Nuclear Information System (INIS)

    Stafford, P.L.

    1996-05-01

    Simulations of a tritium tracer experiment in fractured shale saprolite, conducted at the Oak Ridge National Laboratory, were performed using 1D and 2D equivalent porous medium (EPM) and discrete-fracture/matrix-diffusion (DFMD) models. The models successfully reproduced the general shape of the breakthrough curves in down-gradient monitoring wells which are characterized by rapid first arrival, a slow-moving center of mass, and a persistent ''tail'' of low concentration. In plan view, the plume shows a large degree of transverse spreading with the width almost as great as the length. EPM models were sensitive to dispersivity coefficient values which had to be large (relative to the 3.7m distance between the injection and monitoring wells) to fit the tail and transverse spreading. For example, to fit the tail a longitudinal dispersivity coefficient, α L , of 0.8 meters for the 2D simulations was used. To fit the transverse spreading, a transverse dispersivity coefficient, α T , of 0.8 to 0.08 meters was used indicating an α L /α T ratio between 10 and 1. Transverse spreading trends were also simulated using a 2D DFMD model using a few larger aperture fractures superimposed onto an EPM. Of the fracture networks studied, only those with truncated fractures caused transverse spreading. Simulated tritium levels in all of the cases were larger than observed values by a factor of approximately 100. Although this is partly due to input of too much tritium mass by the models it appears that dilution in the wells, which were not purged prior to sampling, is also a significant factor. The 1D and 2D EPM models were fitted to monitoring data from the first five years of the experiment and then used to predict future tritium concentrations

  13. Validation of the BERT Point Source Inversion Scheme Using the Joint Urban 2003 Tracer Experiment Dataset - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Sara [Los Alamos National Laboratory; Brown, Michael J. [Los Alamos National Laboratory

    2012-06-18

    zones. Due to a unique source inversion technique - called the upwind collector footprint approach - the tool runs fast and the source regions can be determined in a few minutes. In this report, we provide an overview of the BERT framework, followed by a description of the source inversion technique. The Joint URBAN 2003 field experiment held in Oklahoma City that was used to validate BERT is then described. Subsequent sections describe the metrics used for evaluation, the comparison of the experimental data and BERT output, and under what conditions the BERT tool succeeds and performs poorly. Results are aggregated in different ways (e.g., daytime vs. nighttime releases, 1 vs. 2 vs. 3 hit collectors) to determine if BERT shows any systematic errors. Finally, recommendations are given for how to improve the code and procedures for optimizing performance in operational mode.

  14. Market variations in intensity of Medicare service use and beneficiary experiences with care.

    Science.gov (United States)

    Mittler, Jessica N; Landon, Bruce E; Fisher, Elliot S; Cleary, Paul D; Zaslavsky, Alan M

    2010-06-01

    Examine associations between patient experiences with care and service use across markets. Medicare fee-for-service (FFS) and managed care (Medicare Advantage [MA]) beneficiaries in 306 markets from the 2003 Consumer Assessments of Healthcare Providers and Systems (CAHPS) surveys. Resource use intensity is measured by the 2003 end-of-life expenditure index. We estimated correlations and linear regressions of eight measures of case-mix-adjusted beneficiary experiences with intensity of service use across markets. We merged CAHPS data with service use data, excluding beneficiaries under 65 years of age or receiving Medicaid. Overall, higher intensity use was associated (pmarkets, Medicare FFS and MA beneficiaries reported more problems getting care quickly and less helpful office staff. However, Medicare FFS beneficiaries in higher-intensity markets reported higher overall ratings of their personal physician and main specialist. Medicare MA beneficiaries in higher-intensity markets also reported worse quality of communication with physicians, ability to get needed care, and overall ratings of care. Medicare beneficiaries in markets characterized by high service use did not report better experiences with care. This trend was strongest for those in managed care.

  15. Accurate line intensities for water transitions in the infrared: Comparison of theory and experiment

    Science.gov (United States)

    Birk, Manfred; Wagner, Georg; Loos, Joep; Lodi, Lorenzo; Polyansky, Oleg L.; Kyuberis, Aleksandra A.; Zobov, Nikolai F.; Tennyson, Jonathan

    2017-12-01

    Ab initio calculations of water intensities are becoming mature and are claimed to have 1% accuracy in many cases. Experimental intensities with 1% accuracy can be achieved with some care. An intercomparison of ab initio against experimental water intensities is presented for a variety of infrared bands for H216O and some for H218O and H217O. A new calculated H216O line list is presented for which uncertainties in the ab initio line intensities are evaluated. Much of the data show agreement within 2% between ab initio and experiment, however, for some bands, notably those involving excitation of some stretching modes, there are larger offsets of up to 8% attributed to ab initio calculation errors but still within the uncertainty of the ab initio calculation. In the ν1 fundamental band differences of between + 5 % and - 13 % are found which show systematic dependence on wavenumber, ΔKa , and ΔJ , again attributable to ab initio calculation errors. In the ν2 band, intensity-dependent differences up to 2% originate from the analysis of the experimental data. At present experiments are important to validate ab initio calculations but ab initio predictions can be very useful in validating the experiment. As the two procedures display significantly different systematic errors, it is suggested that combining both gives the best results; this study will also facilitate further improvements of the theoretical methodology.

  16. The Merit(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    CERN Document Server

    Efthymiopoulos, I; Caretta, O; Carroll, A J; Fabich, A; Graves, V B; Grudiev, A; Haug, F; Kirk, H G; Lettry, Jacques; Loveridge, P; McDonald, K T; Mokhov, N; Palm, M; Park, H; Pernegger, H; Spampinato, P T; Steerenberg, R; Striganov, S; Tsang, T

    2008-01-01

    The MERIT(nTOF-11) experiment is a proof-ofprinciple test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of $30 × 10^{12}$ per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Partice detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here.

  17. Parent experiences of communication with healthcare professionals in neonatal intensive care units

    DEFF Research Database (Denmark)

    Weis, Janne; Lundqvist, Pia

    2016-01-01

    REVIEW QUESTION/OBJECTIVE: The objectives of this review are to explore parents' experiences of communication with healthcare professionals and to identify the meaningfulness of communication to parents in the neonatal intensive care unit (NICU).More specifically, the objectives are to identify....

  18. Parents' Experiences during Their Infant's Transition from Neonatal Intensive Care Unit to Home: A Qualitative Study

    Science.gov (United States)

    Hutchinson, Sharon W.; Spillet, Marydee A.; Cronin, Mary

    2012-01-01

    Limited literature exists which examines how parents of infants hospitalized in the Neonatal Intensive Care Unit (NICU) transition from their infant's NICU hospital stay to home. This study examines the question, "What are the experiences of parents during their infant's transition from the NICU to home?" Grounded theory methods served as the…

  19. Kinetic study of COS with tertiary alkanolamine solutions 1. Experiments in an intensely stirred batch reactor

    NARCIS (Netherlands)

    Littel, R.J.; Littel, R.J.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1992-01-01

    The reaction between COS and various tertiary alkanolamines in aqueous solutions has been studied in an intensely stirred batch reactor. Experiments for TEA, DMMEA, and DEMEA were carried out at 303 K the reaction between COS and aqueous MDEA has been studied at temperaturm ranging from 293 to 323

  20. Kinetic Study of COS with Tertiary Alkanolamine Solutions. 1. Experiments in an Intensely Stirred Batch Reactor

    NARCIS (Netherlands)

    Littel, Rob J.; Versteeg, Geert F.; Swaaij, Wim P.M. van

    1992-01-01

    The reaction between COS and various tertiary alkanolamines in aqueous solutions has been studied in an intensely stirred batch reactor. Experiments for TEA, DMMEA, and DEMEA were carried out at 303 K; the reaction between COS and aqueous MDEA has been studied at temperatures ranging from 293 to 323

  1. Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus clay, anhydrite and quartz

    Science.gov (United States)

    Zakhnini, Abdelhamid; Kulenkampff, Johannes; Sauerzapf, Sophie; Pietrzyk, Uwe; Lippmann-Pipke, Johanna

    2013-08-01

    Understanding conservative fluid flow and reactive tracer transport in soils and rock formations requires quantitative transport visualization methods in 3D+t. After a decade of research and development we established the GeoPET as a non-destructive method with unrivalled sensitivity and selectivity, with due spatial and temporal resolution by applying Positron Emission Tomography (PET), a nuclear medicine imaging method, to dense rock material. Requirements for reaching the physical limit of image resolution of nearly 1 mm are (a) a high-resolution PET-camera, like our ClearPET scanner (Raytest), and (b) appropriate correction methods for scatter and attenuation of 511 keV—photons in the dense geological material. The latter are by far more significant in dense geological material than in human and small animal body tissue (water). Here we present data from Monte Carlo simulations (MCS) reflecting selected GeoPET experiments. The MCS consider all involved nuclear physical processes of the measurement with the ClearPET-system and allow us to quantify the sensitivity of the method and the scatter fractions in geological media as function of material (quartz, Opalinus clay and anhydrite compared to water), PET isotope (18F, 58Co and 124I), and geometric system parameters. The synthetic data sets obtained by MCS are the basis for detailed performance assessment studies allowing for image quality improvements. A scatter correction method is applied exemplarily by subtracting projections of simulated scattered coincidences from experimental data sets prior to image reconstruction with an iterative reconstruction process.

  2. Methylmercury accumulation and elimination in mink (Neovison vison) hair and blood: results of a controlled feeding experiment using stable isotope tracers.

    Science.gov (United States)

    Wang, Wei; Evans, R Douglas; Hickie, Brendan E; Rouvinen-Watt, Kirsti; Evans, Hayla E

    2014-12-01

    Concentrations of metals in hair are used often to develop pharmacokinetic models for both animals and humans. Although data on uptake are available, elimination kinetics are less well understood; stable isotope tracers provide an excellent tool for measuring uptake and elimination kinetics. In the present study, methylmercury concentrations through time were measured in the hair and blood of mink (Neovison vison) during a controlled 60-d feeding experiment. Thirty-four mink were fed a standard fish-based diet for 14 d, at the end of which (day 0), 4 mink were sacrificed to determine baseline methylmercury (MeHg) concentrations. From day 0 to day 10, the remaining mink were fed a diet consisting of the base diet supplemented with 0.513 ± 0.013 µg Me(199) Hg/g and 0.163 ± 0.003 µg Me(201) Hg/g. From day 10 to day 60, mink were fed the base diet supplemented with 0.175 ± 0.024 µg Me(201) Hg/g. Animals were sacrificed periodically to determine accumulation of Me(201) Hg in blood and hair over the entire 60-d period and the elimination of Me(199) Hg over the last 50 d. Hair samples, collected from each mink and cut into 2.0-mm lengths, indicate that both isotopes of MeHg appeared in the hair closest to the skin at approximately day 10, with concentrations in the hair reaching steady state from day 39 onward. The elimination rate of Me(199) Hg from the blood was 0.05/d, and the ratio of MeHg in the hair to blood was 119. A large fraction of MeHg (22% to >100%) was stored in the hair, suggesting that in fur-bearing mammals the hair is a major route of elimination of MeHg from the body. © 2014 SETAC.

  3. Parent' s experiences and perceives at premature newborn in the neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Klaudia Urbančič

    2002-05-01

    Full Text Available Text treats parent's experiences and perceives and the significant of their newborn premature infants in the neonatal intensive care unit in the Ljubljana maternity hospital. Aim of health promotion, the significance of health education in health education counselling are presented. The purpose of this study was to introduction parent' s experiences and make an implementation in nursing practice. The advantage is represent by performing health education counselling for parents in intensive care unit permanently. Perceives of parents during living their newborn infant in neonatal intensive care unit are present on five concepts: perceive parents themselves, perceive their infant, perceive the staff and the intensive care setting and perceive their home setting. Results are showing statistic important differences between mothers and fathers at the time of deliver and at the time charging infant home. A questionare was used for collecting data. Process of development instrument is represent. Descriptive statistics and T-test was used for quantitative data analysed. Using method of internal consistent Chronbach alpha tested reliability of scales and mean differences in time are graf protrayed by 95% confident intervals. Results show statistical significant differences on all five concepts of parent's experiences. Methodological findings and reseaarch limitations are also present. Authoress positive evaluates the effect of health education counselling program and find out its positive effect on parent's critical thinking and contributes to quality assurance nursing.

  4. Evaluation of the hydrological flow paths in a gravel bed filter modeling a horizontal subsurface flow wetland by using a multi-tracer experiment.

    Science.gov (United States)

    Birkigt, Jan; Stumpp, Christine; Małoszewski, Piotr; Nijenhuis, Ivonne

    2018-04-15

    In recent years, constructed wetland systems have become into focus as means of cost-efficient organic contaminant management. Wetland systems provide a highly reactive environment in which several removal pathways of organic chemicals may be present at the same time; however, specific elimination processes and hydraulic conditions are usually separately investigated and thus not fully understood. The flow system in a three dimensional pilot-scale horizontal subsurface constructed wetland was investigated applying a multi-tracer test combined with a mathematical model to evaluate the flow and transport processes. The results indicate the existence of a multiple flow system with two distinct flow paths through the gravel bed and a preferential flow at the bottom transporting 68% of tracer mass resulting from the inflow design of the model wetland system. There the removal of main contaminant chlorobenzene was up to 52% based on different calculation approaches. Determined retention times in the range of 22d to 32.5d the wetland has a heterogeneous flow pattern. Differences between simulated and measured tracer concentrations in the upper sediment indicate diffusion dominated processes due to stagnant water zones. The tracer study combining experimental evaluation with mathematical modeling demonstrated the complexity of flow and transport processes in the constructed wetlands which need to be taken into account during interpretation of the determining attenuation processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. [Nurses' perception, experience and knowledge of palliative care in intensive care units].

    Science.gov (United States)

    Piedrafita-Susín, A B; Yoldi-Arzoz, E; Sánchez-Fernández, M; Zuazua-Ros, E; Vázquez-Calatayud, M

    2015-01-01

    Adequate provision of palliative care by nursing in intensive care units is essential to facilitate a "good death" to critically ill patients. To determine the perceptions, experiences and knowledge of intensive care nurses in caring for terminal patients. A literature review was conducted on the bases of Pubmed, Cinahl and PsicINFO data using as search terms: cuidados paliativos, UCI, percepciones, experiencias, conocimientos y enfermería and their alternatives in English (palliative care, ICU, perceptions, experiences, knowledge and nursing), and combined with AND and OR Boolean. Also, 3 journals in intensive care were reviewed. Twenty seven articles for review were selected, most of them qualitative studies (n=16). After analysis of the literature it has been identified that even though nurses perceive the need to respect the dignity of the patient, to provide care aimed to comfort and to encourage the inclusion of the family in patient care, there is a lack of knowledge of the end of life care in intensive care units' nurses. This review reveals that to achieve quality care at the end of life, is necessary to encourage the training of nurses in palliative care and foster their emotional support, to conduct an effective multidisciplinary work and the inclusion of nurses in decision making. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  6. Experiences of Turkish undergraduate nursing students in the intensive care unit.

    Science.gov (United States)

    Tastan, Sevinc; Iyigun, Emine; Ayhan, Hatice; Hatipoglu, Sevgi

    2015-01-01

    Clinical practicum provides many opportunities for nursing students to learn more about their subject and develop essential nursing skills. In contrast, nursing students often have difficulties during their clinical practicum. This study aims to describe the clinical experiences of undergraduate nursing students in the intensive care unit. A descriptive qualitative approach was used in this study. The study was performed at a military medical academy between 1 March and 30 April 2008. The study was conducted with 15 fourth-year baccalaureate nursing students. Data were obtained through open-ended and in-depth audio-taped interviews, which lasted approximately 35-45 min. Themes emerged from the participants' descriptions of their experiences in the intensive care unit: anxiety, fear of doing harm, emotional connection and empathy, improving self-confidence, perceived responsibility for patients, prioritizing care of patients, preserving dignity, coping with confronting situations, and communication in the intensive care unit. The views and expectations of nursing students regarding intensive care practice are important for the organization of the nursing education environment. The nursing curriculum must be revised and developed according to the needs of students.

  7. Suitability of tracers

    International Nuclear Information System (INIS)

    Klotz, D.

    1999-01-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other [de

  8. Simulating the Long-Distance Propagation of Intense Beams in the Paul Trap Simulator Experiment

    CERN Document Server

    Gilson, Erik P; Davidson, Ronald C; Efthimion, Philip; Majeski, Richard; Startsev, Edward

    2005-01-01

    The Paul Trap Simulator Experiment (PTSX) makes use of a compact Paul trap configuration with quadrupolar oscillating wall voltages to simulate the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient transport systems. The simulation is possible because of the similarity between the transverse dynamics of particles in the two systems. One-component pure cesium ion plasmas have been trapped that correspond to normalized intensity parameters s < 0.8, where s is the ratio of the square of the plasma frequency to twice the square of the average transverse focusing frequency. The PTSX device confines the plasma for hundreds of milliseconds, which is equivalent to beam propagation over tens of kilometers. Results are presented for experiments in which the amplitude of the oscillating confining voltage waveform has been modified as a function of time. A comparison is made between abrupt changes in amplitude and adiabatic changes in amplitude. T...

  9. Hard X-ray intensity reduction during lower hybrid current drive experiments

    International Nuclear Information System (INIS)

    Mlynar, J.; Stoeckel, J.; Magula, P.

    1993-01-01

    A strong hard X-ray intensity reduction during a standard LHCD at the CASTOR tokamak was studied. From discussion it followed that the magnetic fluctuations level decrease is likely to be responsible for this effect beside the loop voltage decrease. To verify this idea, the connection between the magnetic fluctuation level and the hard X-ray intensity was studied in a nonstandard LHCD regime with a zero loop voltage reduction. These measurements strongly supported the concept that magnetic fluctuations level substantially influences the runaway electrons cross-field transport. Though, more data and a good code for modelling the anomalous transport and hard X-rays production would be of high value. Similar measurements especially for higher RF power should be carried out soon. Besides, the reduction of hard X-rays was observed in the experiments with edge plasma polarization lately; therefore, the magnetic fluctuations level in these experiments should be studied soon. (author) 6 figs., 6 refs

  10. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    Science.gov (United States)

    Box, Dennis

    2014-06-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload. Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.

  11. FIFE-Jobsub: a grid submission system for intensity frontier experiments at Fermilab

    International Nuclear Information System (INIS)

    Box, Dennis

    2014-01-01

    The Fermilab Intensity Frontier Experiments use an integrated submission system known as FIFE-jobsub, part of the FIFE (Fabric for Frontier Experiments) initiative, to submit batch jobs to the Open Science Grid. FIFE-jobsub eases the burden on experimenters by integrating data transfer and site selection details in an easy to use and well-documented format. FIFE-jobsub automates tedious details of maintaining grid proxies for the lifetime of the grid job. Data transfer is handled using the Intensity Frontier Data Handling Client (IFDHC) [1] tool suite, which facilitates selecting the appropriate data transfer method from many possibilities while protecting shared resources from overload. Chaining of job dependencies into Directed Acyclic Graphs (Condor DAGS) is well supported and made easier through the use of input flags and parameters.

  12. Parents’ experiences of communication with neonatal intensive-care unit staff: an interview study

    OpenAIRE

    Wigert, Helena; Dellenmark Blom, Michaela; Bry, Kristina

    2014-01-01

    Background An infant’s admission to a neonatal intensive-care unit (NICU) inevitably causes the parents emotional stress. Communication between parents and NICU staff is an essential part of the support offered to the parents and can reduce their emotional stress. The aim of this study was to describe parents’ experiences of communication with NICU staff. Methods A hermeneutic lifeworld interview study was performed with 18 families whose children were treated in the level III NICU at a unive...

  13. Communicating adaptation with emotions: the role of intense experiences in raising concern about extreme weather.

    Directory of Open Access Journals (Sweden)

    Eleftheria Vasileiadou

    2014-06-01

    Full Text Available Adaptation to extreme weather is often considered as having a low urgency and being a low priority governance option, even though the intensity of extreme weather events is expected to increase as a result of climate change. An important issue is how to raise an adequate level of concern among individuals, policy makers, and broader decision makers in companies and organizations so that adaptation to extreme events becomes mainstream practice. We conducted 40 indepth interviews with individuals from different sectors in The Netherlands to identify the different types of experiences with extreme events, as well as the relationship between such experiences and the level of concern about extreme weather. Our results indicate that individuals who have experienced an intense, life-threatening event have a significantly higher level of concern than those without such an experience. Professional experience and secondhand experience through participating in information events do not significantly affect the level of concern about extreme events. This suggests limited intervention possibilities for communication of adaptation, as well as for raising support for adaptation measures. Framing adaptation measures in relation to personal circumstances and emotions during extreme events could help raise concern about extreme weather events, as well as societal support for adaptation measures.

  14. Tracer monitoring of enhanced oil recovery projects

    Directory of Open Access Journals (Sweden)

    Kleven R.

    2013-05-01

    Full Text Available In enhanced oil recovery (EOR, chemicals are injected into the oil reservoir, either to increase macroscopic sweep efficiency, or to reduce remaining oil saturation in swept zones. Tracers can be used to identify reservoirs that are specifically suited for EOR operations. Injection of a selection of partitioning tracers, combined with frequent sample analysis of produced fluids, provides information suited for estimation of residual oil saturation. Tracers can also be used to evaluate and optimize the application of EOR chemicals in the reservoir. Suitable tracers will follow the EOR chemicals and assist in evaluation of retention, degradation or trapping. In addition to field applications, tracers also have a large potential as a tool to perform mechanistic studies of EOR chemicals in laboratory experiments. By labelling EOR chemicals with radioactive isotopes of elements such as H, C and S, detailed studies of transport mechanisms can be carried out. Co-injection of labelled compounds in dynamic flooding experiments in porous media will give information about retention or separation of the unique compounds constituting the chemical formulation. Separation of such compounds may be detrimental to obtaining the EOR effect expected. The paper gives new information of specific methods, and discusses current status for use of tracers in EOR operations.

  15. Hydrodynamics and radioactive tracers

    International Nuclear Information System (INIS)

    Margrita, R.; Santos-Cottin, H.

    1987-01-01

    Use of radioactive tracers for the description of fluid flow in chemical reactors is exposed. Method and operation are briefly described and examples of applications are given for different industries [fr

  16. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  17. Family members' lived experience in the intensive care unit: a phemenological study.

    LENUS (Irish Health Repository)

    McKiernan, Margaret

    2012-01-31

    AIM: To describe the lived experience of family members of patients in the intensive care unit. BACKGROUND: Admission of a critically ill relative to an intensive care unit causes anxiety and stress to family members. Nursing care is initially focused on maintaining the physiological stability of the patient and less on the needs and concerns of family members. Understanding how families make sense of this experience may help nurses focus on the delivery of family centred care. METHODOLOGY: A phenomenological method was used to describe the lived experiences of family members of patients in an intensive care unit. In-depth interviews were conducted with six family members and analysed using qualitative thematic analysis. RESULTS: Four main themes emerged from the data: the need to know, making sense of it all, being there with them and caring and support. Family members needed honest information about the patient\\'s progress and outcome to make the situation more bearable for them. Making sense of the situation was a continuous process which involved tracking and evaluating care given. Being with their relative sustained their family bond and was a way to demonstrate love and support. Caring reassurance provided by the nurses enabled a sense of security. Support was needed by family members to assist them in coping. CONCLUSION: The research provided an insight into how family members viewed the impact of the admission and how they subsequently found ways of dealing with the situation. RELEVANCE TO CLINICAL PRACTICE: Using a holistic approach to nursing assessment and care delivery in intensive care necessitates that nurses interact with and care for family members of patients. Development of a philosophy of family centred care is necessary, with formal assessment of families to take place soon after admission and an appropriate plan of care drawn up at this time.

  18. Comparison of three labeled silica nanoparticles used as tracers in transport experiments in porous media. Part II: transport experiments and modeling.

    Science.gov (United States)

    Vitorge, Elsa; Szenknect, Stéphanie; Martins, Jean M-F; Barthès, Véronique; Gaudet, Jean-Paul

    2014-01-01

    Three types of labeled silica nanoparticles were used in transport experiments in saturated sand. The goal of this study was to evaluate both the efficiency of labeling techniques (fluorescence (FITC), metal (Ag(0) core) and radioactivity ((110m)Ag(0) core)) in realistic transport conditions and the reactive transport of silica nanocolloids of variable size and concentration in porous media. Experimental results obtained under contrasted experimental conditions revealed that deposition in sand is controlled by nanoparticles size and ionic strength of the solution. A mathematical model is proposed to quantitatively describe colloid transport. Fluorescent labeling is widely used to study fate of colloids in soils but was the less sensitive one. Ag(0) labeling with ICP-MS detection was found to be very sensitive to measure deposition profiles. Radiolabeled ((110m)Ag(0)) nanoparticles permitted in situ detection. Results obtained with radiolabeled nanoparticles are wholly original and might be used for improving the modeling of deposition and release dynamics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Site characterization and validation - Tracer migration experiment in the validation drift, report 2, Part 2: breakthrough curves in the validation drift appendices 5-9

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.; Moreno, L.

    1992-01-01

    Flowrate curves for the 53 sampling areas in the validation drift with measureable flowrates are given. The sampling area 267 is treated as three separate sampling areas; 267:1, 267:2 and 267:3. The total flowrate for these three sampling areas is given in a separate plot. The flowrates are given in ml/h. The time is given in hours since April 27 00:00, 1990. Disturbances in flowrates are observed after 8500 hours due to opening of boreholes C1 and W1. Results from flowrate measurements after 8500 hours are therefore excluded. The tracer breakthrough curves for 38 sampling areas in the validation drift are given as concentration values versus time. The sampling area 267 is treated as three separate sampling areas; 267:1, 267:2 and 267:3. This gives a total of 40 breakthrough curves for each tracer. (au)

  20. MERIT - The high intensity liquid mercury target experiment at the CERN PS

    CERN Document Server

    Efthymiopoulos, I

    2009-01-01

    The MERIT experiment is a proof-of-principle test of a target system for high power proton beams to be used as front-end for a Neutrino Factory complex or a Muon Collider. The experiment took data in autumn 2007 with the fast extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of about 30 × 1012 protons per pulse. The target system, based on a free mercury jet, allowed investigation of the interseption of a 4-MW proton beam inside a 15-T magnetic field required to capture the low-energy secondary pions as the source of the required intense muon beams. Particle detectors have been installed around the target setup to measure the secondary particle flux out of the target and probe cavitation effects in the mercury jet when exited with a beam of variable intensity. With the analysis of the data ongoing, results will be presented here that demonstrate the validity of the liquid target concept.

  1. Ammonium and nitrate uptake lengths in a small forested stream determined by {sup 15}N tracer and short-term nutrient enrichment experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P.J.; Tank, J.L.; Sanzone, D.M.; Webster, J.R.; Wollheim, W.; Peterson, B.J.; Meyer, J.L.

    1998-11-01

    Nutrient cycling is an important characteristic of all ecosystems, including streams. Nutrients often limit the growth rates of stream algae and heterotrophic microbes and the decomposition rate of allochthonous organic matter. Nutrient uptake (S{sub W}), defined as the mean distance traveled by a nutrient atom dissolved in stream water before uptake by biota is often used as an index of nutrient cycling in streams. It is often overlooked, however, that S{sub W} is not a measure of nutrient uptake rate per se, but rather a measure of the efficiency with which a stream utilizes the available nutrient supply. The ideal method for measuring S{sub W} involves short-term addition of a nutrient tracer. Regulatory constraints often preclude use of nutrient radiotracers in field studies and methodological difficulties and high analytical costs have previously hindered the use of stable isotope nutrient tracers (e.g., {sup 15}N). Short-term nutrient enrichments are an alternative to nutrient tracer additions for measuring S{sub W}.

  2. Intensity and direction of competitive anxiety as a function of sport type and experience.

    Science.gov (United States)

    Mellalieu, Stephen D; Hanton, Sheldon; O'Brien, Michael

    2004-10-01

    Using Jones' (1995) model of control, intensity (level) and direction (interpretation) of symptoms associated with competitive trait anxiety were examined as a function of sport type and competitive experience. Participants from gross explosive and fine motor-skill sports (n = 162) completed a trait version of the Competitive State Anxiety Inventory-2 (Martens et al., 1990a) including intensity and direction subscales (Jones & Swain, 1992). Main effects for experience and sport type were reported with gross explosive sports indicating symptoms associated with competitive anxiety as more facilitative to performance than fine motor-skill sports. Experienced performers also reported more-facilitating interpretations of symptoms than their less-experienced counterparts. The findings provide support from a dispositional context to suggest that sport type and the level of competitive experience influence interpretation of symptoms usually experienced in pressure situations. Implementation of activation, relaxation or restructuring interventions contingent upon the nature of the sport is recommended with consideration of the development of confidence-building strategies in less-experienced performers.

  3. Clinical User Experience Testing of Ambient Lighting for Neonatal Intensive Care

    OpenAIRE

    Simons, P.R.; Visser, H.M.

    2012-01-01

    Believed to the first application of its kind in the UK, Philips hasinstalled dynamic and ambient LED lighting in the recently extendedNeonatal Intensive Care Unit, (NICU), at St Michael’s Hospital, Bristol. The neonatal facility was redeveloped in late 2011 with a newICU built next to an existing ICU. This provides the opportunity tomake comparisons between old and new ICU. Philips Research has conducted a clinical user experience trial to assess nurse’s reactions tothe two ICUs. A 3 week us...

  4. Prototype radiographic system for emergency and intensive care units: Initial experience

    International Nuclear Information System (INIS)

    Mirvis, S.

    1986-01-01

    A prototype radiographic system has been developed for use in bedside examinations in multibed trauma or intensive care units and emergency rooms. The system features a single-phase, high-frequency 30-kW ceiling-mounted generator with an x-ray tube extending from a long counterbalanced arm. All movements are servo-assisted for ease of operation. Based on initial experience, the unit allows easier access to the patient around resuscitation and monitoring equipment, occupies less floor space, and yields better quality images than do standard mobile radiographic units

  5. Experience with High-Intensity Beam Scraping and Tail Population at the Large Hadron Collider

    CERN Document Server

    Redaelli, S; Burkart, F; Bruce, R; Mirarchi, D; Salvachua, B; Valentino, G; Wollmann, D

    2013-01-01

    The population of beam tails at the Large Hadron Collider (LHC) is a source of concern for the operation at higher beam energies and intensities when even small fractions of the beam could represent a potential danger is case of slow or fast losses, e.g. caused by orbit transients or by collimator movements. Different studies have been performed using the technique of collimator scans to probe the beam tail population in different conditions. The experience accumulated during the operation at 3.5 TeV and 4 TeV is reviewed.

  6. Intensive care nurses' experiences and perceptions of delirium and delirium care.

    Science.gov (United States)

    Zamoscik, Katarzyna; Godbold, Rosemary; Freeman, Pauline

    2017-06-01

    To explore nurses' experiences and perceptions of delirium, managing delirious patients, and screening for delirium, five years after introduction of the Confusion Assessment Method for Intensive Care into standard practice. Twelve nurses from a medical-surgical intensive care unit in a large teaching hospital attended two focus group sessions. The collected qualitative data was thematically analysed using Braun and Clarke's framework (2006). The analysis identified seven themes: (1) Delirium as a Secondary Matter (2) Unpleasant Nature of Delirium (3) Scepticism About Delirium Assessment (4) Distrust in Delirium Management (5) Value of Communication (6) Non-pharmacological Therapy (7) Need for Reviewed Delirium Policy. Nurses described perceiving delirium as a low priority matter and linked it to work culture within the intensive care specialty. Simultaneously, they expressed their readiness to challenge this culture and to promote the notion of providing high-quality delirium care. Nurses discussed their frustrations related to lack of confidence in assessing delirium, as well as lack of effective therapies in managing this group of patients. They declared their appreciation for non-pharmacological interventions in treatment of delirium, suggested improvements to current delirium approach and proposed introducing psychological support for nurses dealing with delirious patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Federated data storage system prototype for LHC experiments and data intensive science

    Science.gov (United States)

    Kiryanov, A.; Klimentov, A.; Krasnopevtsev, D.; Ryabinkin, E.; Zarochentsev, A.

    2017-10-01

    Rapid increase of data volume from the experiments running at the Large Hadron Collider (LHC) prompted physics computing community to evaluate new data handling and processing solutions. Russian grid sites and universities’ clusters scattered over a large area aim at the task of uniting their resources for future productive work, at the same time giving an opportunity to support large physics collaborations. In our project we address the fundamental problem of designing a computing architecture to integrate distributed storage resources for LHC experiments and other data-intensive science applications and to provide access to data from heterogeneous computing facilities. Studies include development and implementation of federated data storage prototype for Worldwide LHC Computing Grid (WLCG) centres of different levels and University clusters within one National Cloud. The prototype is based on computing resources located in Moscow, Dubna, Saint Petersburg, Gatchina and Geneva. This project intends to implement a federated distributed storage for all kind of operations such as read/write/transfer and access via WAN from Grid centres, university clusters, supercomputers, academic and commercial clouds. The efficiency and performance of the system are demonstrated using synthetic and experiment-specific tests including real data processing and analysis workflows from ATLAS and ALICE experiments, as well as compute-intensive bioinformatics applications (PALEOMIX) running on supercomputers. We present topology and architecture of the designed system, report performance and statistics for different access patterns and show how federated data storage can be used efficiently by physicists and biologists. We also describe how sharing data on a widely distributed storage system can lead to a new computing model and reformations of computing style, for instance how bioinformatics program running on supercomputers can read/write data from the federated storage.

  8. ALBOREX: an intensive multi-platform and multidisciplinary experiment in the Alboran Sea

    Science.gov (United States)

    Ruiz, Simón; Pascual, Ananda; Allen, John; Olita, Antonio; Tovar, Antonio; Oguz, Temel; Mahadevan, Amala; Poulain, Pierre; Tintoré, Joaquín

    2015-04-01

    An intensive multi-platform and multidisciplinary experiment was completed in May 2014 as part of PERSEUS EU Project. 25 drifters, 2 gliders, 3 Argo floats and one ship were dedicated to sample an area of about 50x50 km in the eastern Alboran Sea during one week. The experiment, which also includes 66 CTD stations and 500 water samples (salinity, chlorophyll and nutrients), was designed to capture the intense but transient vertical exchanges associated with mesoscale and submesoscale features. The vertical motion associated with mesoscale and submesoscale features such as ocean eddies, filaments and fronts plays a major role in determining ocean productivity, due to the exchange of properties between the surface and the ocean interior. Understanding the relationship between these physical and biological processes is crucial for predicting the marine ecosystems response to changes in the climate system and to sustainable marine resource management. However, to understand the links between mesoscale and submesoscale features and ecosystem responses, it is necessary to collect data at a range of temporal and spatial scales, and then combine these data with coupled physical and biochemical models. Data from thermosalinograph revealed a sharp surface salinity front with values ranging from 36.6 (Atlantic Waters) to 38.2 (Mediterranean Waters) in conjunction with a filament in temperature. Drifters followed a massive anticyclonic gyre. Near real time data from ADCP showed coherent patterns with currents up to 1m/s. Gliders detected a subduction of chlorophyll located in areas adjacent to the front. We also present results on the horizontal strain rate, relative vorticity and quasi-geostrophic vertical motion to understand the dynamics of this intense ocean front.

  9. A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

    Science.gov (United States)

    Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

    2015-09-01

    The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde

  10. Single-well tracer methods for hydrogeologic evaluation of target aquifers

    International Nuclear Information System (INIS)

    Hall, S.H.

    1994-11-01

    Designing an efficient well field for an aquifer thermal energy storage (ATES) project requires measuring local groundwater flow parameters as well as estimating horizontal and vertical inhomogeneity. Effective porosity determines the volume of aquifer needed to store a given volume of heated or chilled water. Ground-water flow velocity governs the migration of the thermal plume, and dispersion and heat exchange along the flow path reduces the thermal intensity of the recovered plume. Stratigraphic variations in the aquifer will affect plume dispersion, may bias the apparent rate of migration of the plume, and can prevent efficient hydraulic communication between wells. Single-well tracer methods using a conservative flow tracer such as bromide, along with pumping tests and water-level measurements, provide a rapid and cost-effective means for estimating flow parameters. A drift-and-pumpback tracer test yields effective porosity and flow velocity. Point-dilution tracer testing, using new instrumentation for downhole tracer measurement and a new method for calibrating the point-dilution test itself, yields depth-discrete hydraulic conductivity as it is affected by stratigraphy, and can be used to estimate well transmissivity. Experience in conducting both drift-and-pumpback and point-dilution tests at three different test sites has yielded important information that highlights both the power and the limitations of the single-well tracer methods. These sites are the University of Alabama Student Recreation Center (UASRC) ATES well field and the VA Medical Center (VA) ATES well field, both located in Tuscaloosa, Alabama, and the Hanford bioremediation test site north of Richland, Washington

  11. Boron isotopes as an artificial tracer.

    Science.gov (United States)

    Quast, Konrad W; Lansey, Kevin; Arnold, Robert; Bassett, Randy L; Rincon, Martha

    2006-01-01

    A field study was conducted using a combination of intrinsic and artificial tracers to estimate travel times and dilution during transport of infiltrate from a reclaimed water infiltration basin to nearby monitoring wells. A major study objective was to validate boric acid enriched in (10)B as an artificial tracer. Basin 10E at the Rio Hondo Spreading Grounds in Whittier, California, was the site of the test. The basin normally receives a mixture of treated municipal waste water, purchased State Project water, and local runoff from the San Gabriel River. Approximately 3.5 kg of (10)B-enriched boric acid was dispersed among 2.05 x 10(5) m(3) of basin water to initiate the experiment. The resultant median delta(11)B in the infiltration basin was -71 per thousand. Prior to tracer addition, the basin water had an intrinsic delta(11)B of +2 per thousand. Local monitoring wells that were used to assess travel times had delta(11)B values of +5 per thousand and +8 per thousand at the time of tracer addition. Analytic results supported an assumption that boron is conserved during ground water transport and that boron enriched in (10)B is a useful artificial tracer. Several intrinsic tracers were used to reinforce the boric acid tracer findings. These included stable isotopes of oxygen (delta(18)O) and hydrogen (deltaD), sulfate concentration, and the boron to chloride ratio. Xenon isotopes, (136)Xe and (124)Xe, also supported boron isotope results. Xenon isotopes were added to the recharge basin as dissolved gases by investigators from the Lawrence Livermore National Laboratory.

  12. Numerical Implementation and Computer Simulation of Tracer ...

    African Journals Online (AJOL)

    Numerical Implementation and Computer Simulation of Tracer Experiments in a Physical Aquifer Model. ... African Research Review ... A sensitivity analysis showed that the time required for complete source depletion, was most dependent on the source definition and the hydraulic conductivity K of the porous medium.

  13. Xanthine tracers and their preparation

    International Nuclear Information System (INIS)

    Groman, E.V.; Cabelli, M.D.

    1980-01-01

    Compounds useful as tracers in the radioimmunoassay of xanthine derivatives such as theophylline and pharmacologically related drugs are described. They are substituted xanthines in which at least one substituted radical contains radioiodine. The tracers are made by linking radioiodinatable or preradioiodinated radicals to the xanthine derivative which is to be assayed. The tracers may be employed in known radioimmunoassay techniques. (author)

  14. A tunable, linac based, intense, broad-band THz source forpump-probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schmerge, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Adolphsen, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Corbett, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Dolgashev, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Durr, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fazio, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fisher, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Frisch, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gaffney, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Guehr, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hastings, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hettel, B. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hoffmann, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hogan, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Holtkamp, N. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kirchmann, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); LaRue, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Limborg, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lindenberg, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Maxwell, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nilsson, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Raubenheimer, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Reis, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ross, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stupakov, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tantawi, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tian, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wu, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Xiang, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Yakimenko, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-02

    We propose an intense THz source with tunable frequency and bandwidth that can directly interact with the degrees of freedom that determine the properties of materials and thus provides a new tool for controlling and directing these ultrafast processes as well as aiding synthesis of new materials with new functional properties. This THz source will broadly impact our understanding of dynamical processes in matter at the atomic-scale and in real time. Established optical pumping schemes using femtosecond visible frequency laser pulses for excitation are extended into the THz frequency regime thereby enabling resonant excitation of bonds in correlated solid state materials (phonon pumping), to drive low energy electronic excitations, to trigger surface chemistry reactions, and to all-optically bias a material with ultrashort electric fields or magnetic fields. A linac-based THz source can supply stand-alone experiments with peak intensities two orders of magnitude stronger than existing laser-based sources, but when coupled with atomic-scale sensitive femtosecond x-ray probes it opens a new frontier in ultrafast science with broad applications to correlated materials, interfacial and liquid phase chemistry, and materials in extreme conditions.

  15. Time Integrated Soft X-ray Imaging in High Intensity Laser Experiments (thesis)

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, David [Univ. of California, Davis, CA (United States)

    2009-01-01

    2009 marks a significant achievement and the dawn of a new era in high intensity laser research with the final commissioning of all 192 beams at the National Ignition Facility (NIF). NIF is a department of energy (DOE) funded project more than 10 years in the making located at the Lawrence Livermore National Laboratory (LLNL). The following research was done as one of many preliminary experiments done to prepare for these historic events. The primary focus of the experimental campaign this paper addresses is to test and develop a thermal x-radiation source using a short pulse laser. This data is hoped to provide information about the thermal transport mechanisms important in the development of prediction models in High Energy Density (HED) science. One of several diagnostics fielded was a soft x-ray imager (SXRI) which is detailed in this paper. The SXRI will be used to measure the relative size of the heated region and also the relative level of specific x-ray emissions among several shot and target configurations. The laser system used was the Titan laser located in the Jupiter Laser Facility (JLF) at Lawrence Livermore National Laboratory (LLNL). Titan uses the JLF Janus Nd:glass laser west frontend system with a Optical Parametric Chirped Pulse Amplification (OPCPA) in place of the nanosecond oscillator. The system is capable of producing laser intensities of over a petawatt with several tens of joules delivered in the beam.

  16. Ward nurses' experiences of the discharge process between intensive care unit and general ward.

    Science.gov (United States)

    Kauppi, Wivica; Proos, Matilda; Olausson, Sepideh

    2018-01-22

    Intensive care unit (ICU) discharges are challenging practices that carry risks for patients. Despite the existing body of knowledge, there are still difficulties in clinical practice concerning unplanned ICU discharges, specifically where there is no step-down unit. The aim of this study was to explore general ward nurses' experiences of caring for patients being discharged from an ICU. Data were collected from focus groups and in-depth interviews with a total of 16 nurses from three different hospitals in Sweden. An inductive qualitative design was chosen. The analysis revealed three themes that reflect the challenges in nursing former ICU patients: a vulnerable patient, nurses' powerlessness and organizational structure. The nurses described the challenge of nursing a fragile patient based on several aspects. They expressed feeling unrealistic demands when caring for a fragile former ICU patient. The demands were related to their own profession and knowledge regarding how to care for this group of patients. The organizational structure had an impact on how the nurses' caring practice could be realized. This evoked ethical concerns that the nurses had to cope with as the organization's care guidelines did not always favour the patients. The structure of the organization and its leadership appear to have a significant impact on the nurses' ability to offer patients the care they need. This study sheds light on the need for extended outreach services and intermediate care in order to meet the needs of patients after the intensive care period. © 2018 British Association of Critical Care Nurses.

  17. The experiences of high intensity therapists delivering cognitive behavioural therapy to people with intellectual disabilities.

    Science.gov (United States)

    Marwood, Hayley; Chinn, Deborah; Gannon, Kenneth; Scior, Katrina

    2018-01-01

    People with intellectual disabilities (ID) should be able to access the Improving Access to Psychological Therapies (IAPT) programme, currently a main provider of mainstream mental health services in England. IAPT offer cognitive behavioural therapy (CBT) to individuals experiencing mental health problems, although its effectiveness for people with ID, when delivered within IAPT, is unclear. Ten high-intensity therapists took part in semi-structured interviews, analysed using thematic analysis, regarding their experiences of delivering CBT to people with ID in IAPT. The rigidity of the IAPT model appears to offer a poor fit with the needs of people with ID. Therapists appeared uncertain about how to modify CBT and highlighted training and service development needs. Findings suggest barriers to accessing IAPT largely remain unaddressed where people with ID are concerned. Services may need to reconsider what constitutes appropriate reasonable adjustments to ensure equitable access. © 2017 John Wiley & Sons Ltd.

  18. Taking care of the newborn dying and their families: Nurses' experiences of neonatal intensive care

    Directory of Open Access Journals (Sweden)

    Fabiane de Amorim Almeida

    2016-06-01

    Full Text Available Objective To understand the experiences of nurses when caring for dying newborns and their families in the NICU; and redeem their perceptions about acting before the death and grieving process. Method A descriptive exploratory study with a qualitative approach, developed with nine nurses at the ICU of a hospital in São Paulo (SP, Brazil. Data was collected through semi-structured interviews and analyzed using the Collective Subject Discourse (CSD. Results Caring for newborns who are dying and their families is very difficult for nurses, due to the intense involvement. They seek strategies to deal with the situation and, before the newborn’s death, despite the suffering, express the feeling of accomplishment. Conclusions Facing death and grief triggers mechanisms that emerge life references, coming across painful issues. Learning to deal with these questions is a daily challenge for nurses of the NICU.

  19. Monitoring grazing intensity: an experiment with canopy spectra applied to satellite remote sensing

    Science.gov (United States)

    Li, Fei; Zhao, Ying; Zheng, Jiajia; Luo, Juhua; Zhang, Xiaoqiang

    2016-04-01

    The quantification of grassland grazing intensity (GI) and its detailed spatial distribution are important for grassland management and ecological protection. Remote sensing has great potential in these areas, but its use is still limited. This study analyzed the impacts of grazing on biophysical properties of vegetation and suggested using biomass to quantify GI because of its stability and interpretability. In comparison to a single spectral index, such as the red edge index (REI), combining REI and a cellulose absorption ratio index calculated from hyperspectral data performs better for biomass estimation. Further, an auxiliary spectral index, called the grazing monitoring index (GMI), was developed based on differences in spectral reflectance in the infrared range. Experiments in a grazing area of the Inner Mongolia grassland indicated that GMI can identify GI, with three range intervals (GMI blocks in the experimental grazing area. Overall, our study provides inspiration and ideas for using satellite remote sensing for evaluating plant production, standing biomass, and livestock impacts.

  20. Measuring patients' experiences of respect and dignity in the intensive care unit: a pilot study.

    Science.gov (United States)

    Aboumatar, Hanan; Beach, Mary Catherine; Yang, Ting; Branyon, Emily; Forbes, Lindsay; Sugarman, Jeremy

    2015-01-01

    In this study, we tested the feasibility of conducting quantitative assessments of patients' experiences with care in the intensive care unit (ICU), in regard to treatment with respect and dignity. Patients completed the Patient Dignity Inventory, Collaborate, and selected domains from the Hospital Consumer Assessment of Health Providers and Systems Survey. Family members were additionally surveyed using the Family Satisfaction in ICU Care questionnaire. Overall, patients reported high levels of satisfaction in terms of nurses and doctors treating them with courtesy and respect; however, physical aspects of care were reported to be more problematic. While this pilot study suggests some target areas for improving treatment with respect and dignity, the findings are limited since many patients were unable to participate in the survey. Future work should be directed at developing new measures that are easier to administer in this setting.

  1. The Application of a Novel Pressurized Liquid Extraction Method to Quantify Organic Tracers Combined with Historic and Novel Organic Contaminants for the Discover-AQ Houston Field Experiment

    Science.gov (United States)

    Clark, A. E.; Yoon, S.; Sheesley, R. J.; Usenko, S.

    2014-12-01

    DISCOVER-AQ is a NASA mission seeking to better understand air quality in cities across the United States. In September 2013, flight, satellite and ground-based data was collected in Houston, TX and the surrounding metropolitan area. Over 300 particulate matter filter samples were collected as part of the ground-based sampling efforts, at four sites across Houston. Samples include total suspended particle matter (TSP) and fine particulate matter (less than 2.5 μm in aerodynamic diameter; PM2.5). For this project, an analytical method has been developed for the pressurized liquid extraction (PLE) of a wide variety of organic tracers and contaminants from quartz fiber filters (QFFs). Over 100 compounds were selected including polycyclic aromatic hydrocarbons (PAHs), hopanes, levoglucosan, organochlorine pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organophosphate flame retardants (OPFRs). Currently, there is no analytical method validated for the reproducible extraction of all seven compound classes in a single automated technique. Prior to extraction, QFF samples were spiked with known amounts of target analyte standards and isotopically-labeled surrogate standards. The QFF were then extracted with methylene chloride:acetone at high temperatures (100˚C) and pressures (1500 psi) using a Thermo Dionex Accelerated Solvent Extractor system (ASE 350). Extracts were concentrated, spiked with known amounts of isotopically-labeled internal standards, and analyzed by gas chromatography coupled with mass spectrometry utilizing electron ionization and electron capture negative ionization. Target analytes were surrogate recovery-corrected to account for analyte loss during sample preparation. Ambient concentrations of over 100 organic tracers and contaminants will be presented for four sites in Houston during DISCOVER-AQ.

  2. Parents' experiences of communication with neonatal intensive-care unit staff: an interview study.

    Science.gov (United States)

    Wigert, Helena; Dellenmark Blom, Michaela; Bry, Kristina

    2014-12-10

    An infant's admission to a neonatal intensive-care unit (NICU) inevitably causes the parents emotional stress. Communication between parents and NICU staff is an essential part of the support offered to the parents and can reduce their emotional stress. The aim of this study was to describe parents' experiences of communication with NICU staff. A hermeneutic lifeworld interview study was performed with 18 families whose children were treated in the level III NICU at a university hospital in Sweden. The interviews were analysed to gain an interpretation of the phenomenon of how parents in the NICU experienced their communication with the staff, in order to find new ways to understand their experience. Parents' experience of communication with the staff during their infant's stay at the NICU can be described by the main theme 'being given attention or ignored in their emotional situation'. The main theme derives from three themes; (1) meeting a fellow human being, (2) being included or excluded as a parent and (3) bearing unwanted responsibility. This study shows that parents experienced communication with the NICU staff as essential to their management of their situation. Attentive communication gives the parents relief in their trying circumstances. In contrast, lack of communication contributes to feelings of loneliness, abandonment and unwanted responsibility, which adds to the burden of an already difficult situation. The level of communication in meetings with staff can have a decisive influence on parents' experiences of the NICU. The staff should thus be reminded of their unique position to help parents handle their emotional difficulties. The organization should facilitate opportunities for good communication between parents and staff through training, staffing and the physical health care environment.

  3. Patient experiences with intensive combination-treatment strategies with glucocorticoids for early rheumatoid arthritis.

    Science.gov (United States)

    Meyfroidt, Sabrina; Van der Elst, Kristien; De Cock, Diederik; Joly, Johan; Westhovens, René; Hulscher, Marlies; Verschueren, Patrick

    2015-03-01

    To investigate patients' experiences with intensive combination-treatment strategies with glucocorticoids (ICTS-GCs) in the early phase of early rheumatoid arthritis (ERA) treatment. We interviewed 26 participants individually, 4-6 months after initiation of ICTS-GCs (t1). Fourteen participants from the same sample took part in one of three focus groups at least 1 year after treatment initiation (t2). Each interview was audio-recorded, literally transcribed and thematically coded. The participants described concerns and feelings about ICTS-GCs that changed over time; for example, a fear of side effects diminished when the treatment effects were beneficial or expected side effects did not materialize. Moreover, participants indicated additional information needs at t1 and t2. The most used sources of information were healthcare professionals, relatives, and the Internet. Furthermore, participants reported on their relationship with healthcare professionals and the need for trust and reassurance, especially at t1. Lastly, participants described their personal self-management strategies. Despite their concerns at treatment initiation, most participants had positive experiences with ICTS-GCs. Healthcare professionals should be aware that, in the early phase of treatment, they can address patients' concerns, they are the most important information source, they need to create a relationship of trust, and guide patients in self-management strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Interdisciplinary Family Conferences to Improve Patient Experience in the Neonatal Intensive Care Unit.

    Science.gov (United States)

    Trujillo, Jennifer A; Fernandez, Yesenia; Ghafoori, Lyla; Lok, Kristina; Valencia, Arwin

    2017-11-01

    Parents play a significant role in the development of their neonate. They can affect the length of stay in a neonatal intensive care unit (NICU) and are seen as an integral part of the team. Parents are often put in positions where difficult decision making is required of them in the care of their critically ill child. Studies suggest that one way to improve the family's experience and to encourage their involvement is by establishing a formal and focused family conference. Therefore, the NICU social workers and the interdisciplinary team collaborated to formulate strategies to improve communication that would enhance current practice. As a new initiative, the team decided that holding an interdisciplinary family conference (IFC) within the first two weeks of a baby's NICU admission is critical for parental involvement of infants less than 32 weeks gestation and those with congenital birth anomalies. The team determined that the primary outcome measure would be family satisfaction scores from hospital surveys. Since the implementation of IFCs, satisfaction scores showed steady improvement. This quality improvement project demonstrated that IFCs are an integral part of the family-centered care approach in the NICU. IFCs foster partnerships with families to ensure their involvement in all aspects of patient care and improve their experience in the NICU. © 2017 National Association of Social Workers.

  5. Experiences and Expressions of Spirituality at the End of Life in the Intensive Care Unit.

    Science.gov (United States)

    Swinton, Marilyn; Giacomini, Mita; Toledo, Feli; Rose, Trudy; Hand-Breckenridge, Tracy; Boyle, Anne; Woods, Anne; Clarke, France; Shears, Melissa; Sheppard, Robert; Cook, Deborah

    2017-01-15

    The austere setting of the intensive care unit (ICU) can suppress expressions of spirituality. To describe how family members and clinicians experience and express spirituality during the dying process in a 21-bed medical-surgical ICU. Reflecting the care of 70 dying patients, we conducted 208 semistructured qualitative interviews with 76 family members and 150 clinicians participating in the Three Wishes Project. Interviews were recorded and transcribed verbatim. Data were analyzed by three investigators using qualitative interpretive description. Participants characterize dying as a spiritual event. Spirituality is an integral part of the life narrative of the patient before, during, and after death. Experiences and expressions of spirituality for patients, families, and clinicians during end-of-life care in the ICU are supported by eliciting and implementing wishes in several ways. Eliciting wishes stimulates conversations for people of diverse spiritual orientations to respond to death in personally meaningful ways that facilitate continuity and closure, and ease emotional trauma. Soliciting wishes identifies positive aspirations, which provide comfort in the face of death. The act of soliciting wishes brings clinician humanity to the fore. Wishing makes individual spiritual preferences and practices more accessible. Wishes may be grounded in spiritual goals, such as peace, comfort, connections, and tributes; they may seek a spiritually enhanced environment or represent specific spiritual interventions. Family members and clinicians consider spirituality an important dimension of end-of-life care. The Three Wishes Project invites and supports the expression of myriad forms of spirituality during the dying process in the ICU.

  6. Radioactive tracers in Sedimentology

    International Nuclear Information System (INIS)

    Rodrigues, H.T.

    1973-01-01

    First is given a broad description of the uses of radioactive tracers in Sedimentology. The general method is established, including determinations of probability and standard deviation. Following are determined: the response law of the detector, the minimum mass for statistical detection, and the minimum mass for dynamic detection. The granularity is an important variable in these calculations. Final conclusions are given, and results are compared with existing theories

  7. Journal: Efficient Hydrologic Tracer-Test Design for Tracer ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed to facilitate the design of tracer tests by root determination of the one-dimensional advection-dispersion equation (ADE) using a preset average tracer concentration which provides a theoretical basis for an estimate of necessary tracer mass. The method uses basic measured field parameters (e.g., discharge, distance, cross-sectional area) that are combined in functional relatipnships that descrive solute-transport processes related to flow velocity and time of travel. These initial estimates for time of travel and velocity are then applied to a hypothetical continuous stirred tank reactor (CSTR) as an analog for the hydrological-flow system to develop initial estimates for tracer concentration, tracer mass, and axial dispersion. Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to be necessary for descri

  8. Ensemble experiments using a nested LETKF system to reproduce intense vortices associated with tornadoes of 6 May 2012 in Japan

    Science.gov (United States)

    Seko, Hiromu; Kunii, Masaru; Yokota, Sho; Tsuyuki, Tadashi; Miyoshi, Takemasa

    2015-12-01

    Experiments simulating intense vortices associated with tornadoes that occurred on 6 May 2012 on the Kanto Plain, Japan, were performed with a nested local ensemble transform Kalman filter (LETKF) system. Intense vortices were reproduced by downscale experiments with a 12-member ensemble in which the initial conditions were obtained from the nested LETKF system analyses. The downscale experiments successfully generated intense vortices in three regions similar to the observed vortices, whereas only one tornado was reproduced by a deterministic forecast. The intense vorticity of the strongest tornado, which was observed in the southernmost region, was successfully reproduced by 10 of the 12 ensemble members. An examination of the results of the ensemble downscale experiments showed that the duration of intense vorticities tended to be longer when the vertical shear of the horizontal wind was larger and the lower airflow was more humid. Overall, the study results show that ensemble forecasts have the following merits: (1) probabilistic forecasts of the outbreak of intense vortices associated with tornadoes are possible; (2) the miss rate of outbreaks should decrease; and (3) environmental factors favoring outbreaks can be obtained by comparing the multiple possible scenarios of the ensemble forecasts.

  9. The lived experience of fathers of preterm infants in the Neonatal Intensive Care Unit: a systematic review of qualitative studies.

    Science.gov (United States)

    Provenzi, Livio; Santoro, Elena

    2015-07-01

    To systematically review the experience of fathers of preterm infants hospitalised in the Neonatal Intensive Care Unit. Family-centred care is more and more acknowledged in Neonatal Intensive Care Units, advocating for active engagement of both parents in the care journey. Nonetheless, fathers' Neonatal Intensive Care Unit experience has received limited research attention. Systematic review of qualitative studies. Four electronic databases (CINHAL, ISI Web of Science, PubMed, Scopus) were explored and studies published between 2000-2014 were included. Preferred Reporting Item for Systematic Reviews and Meta-analysis (PRISMA) and Joanna Briggs Institute (JBI) Critical Appraisal Tool for Qualitative Studies guidelines were adopted. Key themes were extracted and synthesised. Five main themes resuming fathers' experience of preterm birth and Neonatal Intensive Care Unit stay were identified from 14 studies. Themes were: emotional roller-coaster, paternal needs, coping strategies, self-representation and caregiving engagement. These dimensions were found to be dynamically shaped across three critical turning points: preterm birth, Neonatal Intensive Care Unit stay and at home. Neonatal Intensive Care Unit fathers of preterm infants experience ambivalence, a set of different needs and coping strategies. They modify their self-representations along the Neonatal Intensive Care Unit journey and needs specific nursing support and intervention to sustain caregiving engagement and transition to parenthood. A systematic and deepened understanding of preterms' fathers lived experience in Neonatal Intensive Care Unit would be helpful to inform nursing practice. Specific action priorities are suggested within the frame of family-centred care. © 2015 John Wiley & Sons Ltd.

  10. Moral distress in intensive care unit professionals is associated with profession, age, and years of experience.

    Science.gov (United States)

    Dodek, Peter M; Wong, Hubert; Norena, Monica; Ayas, Najib; Reynolds, Steven C; Keenan, Sean P; Hamric, Ann; Rodney, Patricia; Stewart, Miriam; Alden, Lynn

    2016-02-01

    To determine which demographic characteristics are associated with moral distress in intensive care unit (ICU) professionals. We distributed a self-administered, validated survey to measure moral distress to all clinical personnel in 13 ICUs in British Columbia, Canada. Each respondent to the survey also reported their age, sex, and years of experience in the ICU where they were working. We used multivariate, hierarchical regression to analyze relationships between demographic characteristics and moral distress scores, and to analyze the relationship between moral distress and tendency to leave the workplace. Response rates to the surveys were the following: nurses--428/870 (49%); other health professionals (not nurses or physicians)--211/452 (47%); physicians--30/68 (44%). Nurses and other health professionals had higher moral distress scores than physicians. Highest ranked items associated with moral distress were related to cost constraints and end-of-life controversies. Multivariate analyses showed that age is inversely associated with moral distress, but only in other health professionals (rate ratio [95% confidence interval]: -7.3 [-13.4, -1.2]); years of experience is directly associated with moral distress, but only in nurses (rate ratio (95% confidence interval):10.8 [2.6, 18.9]). The moral distress score is directly related to the tendency to leave the ICU job, in both the past and present, but only for nurses and other non-physician health professionals. Moral distress is higher in ICU nurses and other non-physician professionals than in physicians, is lower with older age for other non-physician professionals but greater with more years of experience in nurses, and is associated with tendency to leave the job. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  12. Inside the research incubator: a case study of an intensive undergraduate research experience for nursing a midwifery students.

    Science.gov (United States)

    Kain, Victoria J; Hepworth, Julie; Bogossian, Fiona; McTaggart, Lya

    2014-01-01

    Undergraduate research experiences are an increasing component of nursing and midwifery degrees. The Summer Research Scholarship Programme (SRSP) is a tertiary education initiative in Australia to provide an intensive undergraduate research experience. Between 2009 and 2010, six students and four academic faculty mentors in School of Nursing and Midwifery participated in an inaugural SRSP. This study explores the experiences of both students and faculty mentors to determine how this undergraduate research experience impacted student learning and interest in research. A qualitative case study approach was used to explore the research experiences of undergraduate student and faculty participants in an inaugural undergraduate research programme. Based on the results of two surveys four main themes were identified: (1) acquisition of research skills, (2) expectations, (3) academic engagement, and (4) continued interest in research. An intensive undergraduate research experience is a valuable component of student learning that has the capacity to contribute to immediate and longer-term learning and research outcomes.

  13. In-Situ Characterization of Dense Non-Aqueous Phase Liquids Using Partitioning Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Gary A. Pope; Daene C. McKinney; Akhil Datta Gupta; Richard E. Jackson; Minquan Jin

    2000-03-20

    Majors advances have been made during the past three years in our research on interwell partitioning tracers tests (PITTs). These advances include (1) progress on the inverse problem of how to estimate the three-dimensional distribution of NAPL in aquifers from the tracer data, (2) the first ever partitioning tracer experiments in dual porosity media, (3) the first modeling of partitioning tracers in dual porosity media (4) experiments with complex NAPLs such as coal tar, (5) the development of an accurate and simple method to predict partition coefficients using the equivalent alkane carbon number approach, (6) partitioning tracer experiments in large model aquifers with permeability layers, (7) the first ever analysis of partitioning tracer data to estimate the change in composition of a NAPL before and after remediation (8) the first ever analysis of partitioning tracer data after a field demonstration of surfactant foam to remediate NAPL and (9) experiments at elevated temperatures .

  14. FluxFix: automatic isotopologue normalization for metabolic tracer analysis.

    Science.gov (United States)

    Trefely, Sophie; Ashwell, Peter; Snyder, Nathaniel W

    2016-11-25

    Isotopic tracer analysis by mass spectrometry is a core technique for the study of metabolism. Isotopically labeled atoms from substrates, such as [ 13 C]-labeled glucose, can be traced by their incorporation over time into specific metabolic products. Mass spectrometry is often used for the detection and differentiation of the isotopologues of each metabolite of interest. For meaningful interpretation, mass spectrometry data from metabolic tracer experiments must be corrected to account for the naturally occurring isotopologue distribution. The calculations required for this correction are time consuming and error prone and existing programs are often platform specific, non-intuitive, commercially licensed and/or limited in accuracy by using theoretical isotopologue distributions, which are prone to artifacts from noise or unresolved interfering signals. Here we present FluxFix ( http://fluxfix.science ), an application freely available on the internet that quickly and reliably transforms signal intensity values into percent mole enrichment for each isotopologue measured. 'Unlabeled' data, representing the measured natural isotopologue distribution for a chosen analyte, is entered by the user. This data is used to generate a correction matrix according to a well-established algorithm. The correction matrix is applied to labeled data, also entered by the user, thus generating the corrected output data. FluxFix is compatible with direct copy and paste from spreadsheet applications including Excel (Microsoft) and Google sheets and automatically adjusts to account for input data dimensions. The program is simple, easy to use, agnostic to the mass spectrometry platform, generalizable to known or unknown metabolites, and can take input data from either a theoretical natural isotopologue distribution or an experimentally measured one. Our freely available web-based calculator, FluxFix ( http://fluxfix.science ), quickly and reliably corrects metabolic tracer data for

  15. Use of radioactive tracers in dynamic sedimentology

    International Nuclear Information System (INIS)

    Tola, Francois.

    1982-01-01

    In the first part, developments in the use of radioactive tracers in sedimentology are recalled together with the corresponding fields of application and the identities of the main users. The state-of-the-art in France is also discussed; The main characteristics of the method are then described and compared with those of more classical methods. The results that can be obtained with tracer methods are then outlined. The criteria employed to establish the granulometry characteristics of the tracer, the particular radioisotope to be used, and the masses and activities involved, are treated. A list is then given of the main isotopes available in France and their characteristics. The various different labelling techniques employed are studied together with their respective advantages and disadvantages. The special case of pelitic sediments is mentioned. The use of reduced model isotope generators, double labelling and applications to studies of the mud plug in the Gironde Estuary are also discussed. The methods and materials used for injecting and detecting tracers are described, emphasis being given to the economic factors associated with the use of radioactive tracers in sedimentology. The second part of the report contains two chapters: - studies of transport by driftage: presentation and analysis of results and the application of the Count Rate Balance method to obtain quantitative information on transport; - studies of in-suspension transport of fine sediments in the sea: the procedures adopted from the moment when the tracer is introduced up to the time when the results are analyzed and interpreted, enables the trajectories and mean velocities of the transported sediments to be determined together with their degree of dilution and their settling speeds and rates; it is also possible to investigate the evolution and horizontal dispersion of the sediments in this way. Results from recent experiments are presented in both parts of the report

  16. Hydraulic characterisation of karst systems with man-made tracers

    International Nuclear Information System (INIS)

    Werner, A.

    1998-01-01

    Tracer experiments using man-made tracers are common in hydrogeological exploration of groundwater aquifers in karst systems. In the present investigation, a convection-dispersion model (multidispersion model with consideration of several flow paths) and a single-cleft model (consideration of the diffusion between the cleft and the surrounding rock matrix) were used for evaluating tracer experiments in the main hydrological system of the saturated zone of karst systems. In addition to these extended analytical solutions, a numerical transport model was developed for investigating the influence of the transient flow rate on the flow and transport parameters. Comparative evaluations of the model approaches for the evaluation of tracer experiments were made in four different karst systems: Danube-Aach, Paderborn, Slowenia and Lurbach, of which the Danube-Aach system was considered as the most important. The investigation also comprised three supplementary experiments in order to enable a complete hydraulic characterisation of the system. (orig./SR) [de

  17. Chemical Tracer Methods: Chapter 7

    Science.gov (United States)

    Healy, Richard W.

    2017-01-01

    Tracers have a wide variety of uses in hydrologic studies: providing quantitative or qualitative estimates of recharge, identifying sources of recharge, providing information on velocities and travel times of water movement, assessing the importance of preferential flow paths, providing information on hydrodynamic dispersion, and providing data for calibration of water flow and solute-transport models (Walker, 1998; Cook and Herczeg, 2000; Scanlon et al., 2002b). Tracers generally are ions, isotopes, or gases that move with water and that can be detected in the atmosphere, in surface waters, and in the subsurface. Heat also is transported by water; therefore, temperatures can be used to trace water movement. This chapter focuses on the use of chemical and isotopic tracers in the subsurface to estimate recharge. Tracer use in surface-water studies to determine groundwater discharge to streams is addressed in Chapter 4; the use of temperature as a tracer is described in Chapter 8.Following the nomenclature of Scanlon et al. (2002b), tracers are grouped into three categories: natural environmental tracers, historical tracers, and applied tracers. Natural environmental tracers are those that are transported to or created within the atmosphere under natural processes; these tracers are carried to the Earth’s surface as wet or dry atmospheric deposition. The most commonly used natural environmental tracer is chloride (Cl) (Allison and Hughes, 1978). Ocean water, through the process of evaporation, is the primary source of atmospheric Cl. Other tracers in this category include chlorine-36 (36Cl) and tritium (3H); these two isotopes are produced naturally in the Earth’s atmosphere; however, there are additional anthropogenic sources of them.

  18. Guidebook on radioisotope tracers in industry

    International Nuclear Information System (INIS)

    1990-01-01

    The idea of using tracers (chemical, dyes, etc.) in the investigation of complex physical phenomena has always attracted the attention of scientists and engineers. When radioactive isotopes became available it was immediately recognized that they offered an almost ideal solution to tracer selection. This book is devoted to reviewing the present status of the tracer method as such and to its applications to those branches of industry which have derived large benefits from the use of this modern technology. The main objectives of the IAEA's Industrial Applications and Chemistry Section is to help Member States in introducing to their own industries the different isotope and radiation techniques which have become available as a result of developments in the nuclear sciences. This section proposed the preparation of this guidebook, putting together various radiotracer methods and the experience obtained so far in their industrial use. Chapters 2 to 4 cover the general concept of tracers, technology and safety aspects, as well as data evaluation and interpretation. In chapter 5, therefore, general applications are discussed. In chapter 6, specialists in selected fields discuss their experience in radiotracer applications in various types of industrial activity. Most case studies are illustrated by at least one detailed example of an experiment carried out at an industrial installation. Current trends in the development of radiotracer methods are discussed in chapter 7, from both a theoretical and a practical viewpoint. Some possible new RTT applications in the future are also discussed here. Sealed radioactive sources are used almost as often as radioisotope tracers in industrial measurements. Annex I gives a short review of these techniques. Readers who are interested in the basic principles of radioisotope production will find the necessary information in Annex II. Annexes III, V and VI provide a demonstration of fundamental relations and properties; useful

  19. Yield gap analysis in long-term experiments with intensive rice cultivation

    International Nuclear Information System (INIS)

    Laureles, E.V.; Correa, T. Jr.; Buresh, R.J.

    2007-01-01

    The long-term continuous cropping experiment at IRRI is cultivated with three rice crops in a year, making it the world's most intensively cropped long-term rice experiment. The availability of comprehensive rice production records, compiled weather data, and tested crop models provides a means to evaluate long-term trends in measured and potential yields and yield gaps in this rice production system. Yield trends were assessed using the highest yielding cultivar in each cropping season from 1979 to 2005. Potential yield of the highest yielding cultivar in each season was determined using three rice models (ORYZA, TERM, and CERES) run with the actual transplanting and harvest dates for the cultivar. The yield gap was determined from the difference between the simulated potential grain yield and the measured grain yield. Measured and potential yields and the yield gap varied across seasons and years. Measured yields were higher in the dry season than in the early and late wet seasons. The yield gap tended to be higher in the wet season than in the dry season. Climatic parameters, particularly solar radiation, influenced the performance of rice cultivars. The relatively larger yield gaps in the late wet season than in the dry season were associated with increased spikelet sterility. The cumulative measured yield for the three annual rice crop was near 80 percent of the annual yield potential in years with best practices for fertilizer N and crop management. The long term trends suggest that effective timing and rates of N fertilization and effective control of diseases were critical in achieving 80 percent of the annual yield potential

  20. Transuranic and tracer simulant resuspension

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1977-07-01

    Plutonium resuspension results are summarized for experiments conducted at Rocky Flats, onsite on the Hanford reservation, and for winds blowing from offsite onto the Hanford reservation near the Prosser barricade boundary. In each case, plutonium resuspension was shown by increased airborne plutonium concentrations as a function of either wind speed or as compared to fallout levels. All measured airborne concentrations were below maximum permissible concentrations (MPC). Both plutonium and cesium concentrations on airborne soil were normalized by the quantity of airborne soil sampled. Airborne radionuclide concentrations in μCi/g were related to published values for radionuclide concentrations on surface soils. For this ratio of radionuclide concentration per gram on airborne soil divided by that for ground surface soil, there are eight orders of magnitude uncertainty from 10 -4 to 10 4 . Horizontal plutonium fluxes on airborne nonrespirable soils at all three sites were bracketed within the same three to four orders of magnitude from 10 -7 to 10 -3 μCi/(m 2 day) for plutonium-239 and 10 -8 to 10 -5 μCi/(m 2 day) for plutonium-238. These are the entire experimental base for nonrespirable airborne plutonium transport. Airborne respirable plutonium-239 concentrations increased with wind speed for a southeast wind direction coming from offsite near the Hanford reservation Prosser barricade. Airborne plutonium fluxes on nonrespirable particles had isotopic ratios, 240 Pu/ 239+240 Pu, similar to weapons grade plutonium rather than fallout plutonium. Resuspension rates were summarized for controlled inert particle tracer simulant experiments. Wind resuspension rates for tracers increased with wind speed to about the fifth power

  1. Model-independent curvature determination with 21cm intensity mapping experiments

    Science.gov (United States)

    Witzemann, Amadeus; Bull, Philip; Clarkson, Chris; Santos, Mario G.; Spinelli, Marta; Weltman, Amanda

    2018-04-01

    Measurements of the spatial curvature of the Universe have improved significantly in recent years, but still tend to require strong assumptions to be made about the equation of state of dark energy (DE) in order to reach sub-percent precision. When these assumptions are relaxed, strong degeneracies arise that make it hard to disentangle DE and curvature, degrading the constraints. We show that forthcoming 21cm intensity mapping experiments such as HIRAX are ideally designed to carry out model-independent curvature measurements, as they can measure the clustering signal at high redshift with sufficient precision to break many of the degeneracies. We consider two different model-independent methods, based on `avoiding' the DE-dominated regime and non-parametric modelling of the DE equation of state respectively. Our forecasts show that HIRAX will be able to improve upon current model-independent constraints by around an order of magnitude, reaching percent-level accuracy even when an arbitrary DE equation of state is assumed. In the same model-independent analysis, the sample variance limit for a similar survey is another order of magnitude better.

  2. Methods of 15N tracer research in biological systems

    International Nuclear Information System (INIS)

    Hirschberg, K.; Faust, H.

    1985-01-01

    The application of the stable isotope 15 N is of increasing importance in different scientific disciplines, especially in medicine, agriculture, and the biosciences. The close correlation between the growing interest and improvements of analytical procedures resulted in remarkable advances in the 15 N tracer technique. On the basis of the latest results of 15 N tracer research in life sciences and agriculture methods of 15 N tracer research in biological systems are compiled. The 15 N methodology is considered under three headings: Chemical analysis with a description of methods of sample preparation (including different separation and isolation methods for N-containing substances of biological and agricultural origin) and special procedures converting ammonia to molecular nitrogen. Isotopic analysis with a review on the most important methods of isotopic analysis of nitrogen: mass spectrometry (including the GC-MS technique), emission spectrometry, NMR spectroscopy, and other analytical procedures. 15 N-tracer techniques with a consideration of the role of the isotope dilution analysis as well as different labelling techniques and the mathematical interpretation of tracer data (modelling, N turnover experiments). In these chapters also sources of errors in chemical and isotopic analysis, the accuracy of the different methods and its importance on tracer experiments are discussed. Procedures for micro scale 15 N analysis and aspects of 15 N analysis on the level of natural abundance are considered. Furthermore some remarks on isotope effects in 15 N tracer experiments are made. (author)

  3. Urban Pollutant Transport and Infiltration into Buildings Using Perfluorocarbon Tracers

    Directory of Open Access Journals (Sweden)

    James C. Matthews

    2017-02-01

    Full Text Available People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO2 tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants.

  4. Tracer packet: a novel conception

    International Nuclear Information System (INIS)

    Susanta Lahiri; Dalia Nayak

    2002-01-01

    A new conception over the century old tracer technique and a decade old multitracer technique has been introduced called tracer packet. The probable scope and approaches of the tracer packet technique has briefly been discussed. The various aspects of this technique include, the methods of production and their separation, the application of this technique in the study of metal accumulation and their distribution in biological systems, environmental remediation and many other fields. (Author)

  5. Radionuclides as tracers

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Importance of radioisotopes in medicine is because of their two characteristics: their biological behaviour is identical to their stable counterparts, and because they are radioactive their emissions can be detected by a suitable instrument. All isotopes of iodine will behave in the same way and will concentrate in the thyroid gland. There is no way of detecting the stable, natural iodine in the thyroid gland, but the presence of radioactive iodine can be detected externally in vivo by a detector. Thus, the radioactive iodine becomes a tracer, a sport of a spy, which mimics the behaviour of natural iodine and relays information to a detector. The radioactive tracers are popular because of the ease with which they can be detected in vivo and the fact that the measurement of their presence in the body can be in quantitative terms. The measurement can be very accurate and sensitive. Whenever the measurements can be done in vivo, the information is obtained in dynamic terms, as it is happening, as if the physiological events become transparent

  6. Nanoparticle tracers in calcium carbonate porous media

    KAUST Repository

    Li, Yan Vivian

    2014-07-15

    Tracers are perhaps the most direct way of diagnosing subsurface fluid flow pathways for ground water decontamination and for natural gas and oil production. Nanoparticle tracers could be particularly effective because they do not diffuse away from the fractures or channels where flow occurs and thus take much less time to travel between two points. In combination with a chemical tracer they can measure the degree of flow concentration. A prerequisite for tracer applications is that the particles are not retained in the porous media as the result of aggregation or sticking to mineral surfaces. By screening eight nanoparticles (3-100 nm in diameter) for retention when passed through calcium carbonate packed laboratory columns in artificial oil field brine solutions of variable ionic strength we show that the nanoparticles with the least retention are 3 nm in diameter, nearly uncharged, and decorated with highly hydrophilic polymeric ligands. The details of these column experiments and the tri-modal distribution of zeta potential of the calcite sand particles in the brine used in our tests suggests that parts of the calcite surface have positive zeta potential and the retention of negatively charged nanoparticles occurs at these sites. Only neutral nanoparticles are immune to at least some retention. © 2014 Springer Science+Business Media.

  7. Using radioactive tracer technique in municipal hygiene

    International Nuclear Information System (INIS)

    Yurasova, O.I.

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology

  8. An integrated ultrasound-guided high intensity focused ultrasound system for in-vivo experiment

    Science.gov (United States)

    Liu, Dalong; Ebbini, Emad S.

    2017-03-01

    We present the system architecture of an integrated Ultrasound-guided High Intensity Focused Ultrasound (USgHIFU) system for image-guided surgery and temperature tracking in vivo. The system is capable of operating with multiple frontends. Current implementation has a SonixRP for imaging and a custom designed dual mode ultrasound array (DMUA) system (32Tx/32Rx) for imaging/therapy. The highlights of the system include a fully-programmable, multiple data stream capable data processing engine, and an arbitrarily programmable high power array driver that is able to synthesize complex beam patterns in space and time. The data processing engine features a pipeline-style design that can be programmed on-the-fly by re-arranging the pre-verified GPU-accelerated high performance pipeline blocks, which cover an extensive range from basic functions such as filtering to specialized processing like speckle tracking. Furthermore, the pipeline design also has the option of bringing in MATLAB (Mathworks, Natick, MA, US) as part of the processing chain, thus vastly increase the capability of the system. By properly balancing the processing load between GPU-enabled routine and MATLAB script. This allows one to achieve a high degree of flexibility while meeting real-time constraints. Results are presented from in vivo rat experiment. Where low dose of therapeutic ultrasound was delivered into the hind limb of the Copenhagen rats using DMUA and temperature was tracked using a linear probe (HST, Ultrasonix). The data is processed in realtime with MATLAB in the loop to perform temperature regularization. Results show that we can reliably track the low temperature heating in the presence of motion artifacts (respiration and pulsation).

  9. Experience with Guillain-Barré syndrome in a neurological Intensive Care Unit.

    Science.gov (United States)

    González, P; García, X; Guerra, A; Arango, J C; Delgado, H; Uribe, C S; Sará, J; López de Mesa, J C; Hernández, O

    2016-01-01

    Guillain-Barré syndrome, an acute polyradiculoneuropathy that presents with weakness and areflexia, is the most common cause of acute flaccid paralysis. In certain patients, respiratory failure is secondary to this disorder, eventually causing patients to require mechanical ventilation and experience additional complications due to diminished respiratory support and related mobility limitations. Prognoses for most of these cases are positive; treatment consists of basic support combined with plasmapheresis or administration of immunoglobulins. This study sought to describe the socio-demographic, clinical, laboratory and neurophysiological characteristics of patients with Guillain-Barré syndrome who were hospitalised in the Intensive Care Unit of the Neurological Institute of Colombia between 2006 and 2012. This study presents a case series. We surveyed 25 patients (32% female and 68% male) with Guillain-Barré syndrome and an average age of 54 years. Sixty per cent of these patients were admitted between days 3 and 7 after symptom onset; 64% had a history of respiratory infection and 20% had a history of intestinal infection. In addition, 84% of the patients presented with albuminocytological dissociation. We observed the following clinical subtypes of Guillain-Barré syndrome: inflammatory demyelinating polyneuropathy in 32%, acute motor-sensory axonal neuropathy in 28%, acute motor axonal neuropathy in 28%, and Miller Fisher syndrome in 12%. In this descriptive study of a group of critical care patients with GBS, results depended on patients' clinical severity at time of admission. Our findings are similar to results published in the international literature. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Weed suppression greatly increased by plant diversity in intensively managed grasslands: A continental-scale experiment.

    Science.gov (United States)

    Connolly, John; Sebastià, Maria-Teresa; Kirwan, Laura; Finn, John Anthony; Llurba, Rosa; Suter, Matthias; Collins, Rosemary P; Porqueddu, Claudio; Helgadóttir, Áslaug; Baadshaug, Ole H; Bélanger, Gilles; Black, Alistair; Brophy, Caroline; Čop, Jure; Dalmannsdóttir, Sigridur; Delgado, Ignacio; Elgersma, Anjo; Fothergill, Michael; Frankow-Lindberg, Bodil E; Ghesquiere, An; Golinski, Piotr; Grieu, Philippe; Gustavsson, Anne-Maj; Höglind, Mats; Huguenin-Elie, Olivier; Jørgensen, Marit; Kadziuliene, Zydre; Lunnan, Tor; Nykanen-Kurki, Paivi; Ribas, Angela; Taube, Friedhelm; Thumm, Ulrich; De Vliegher, Alex; Lüscher, Andreas

    2018-03-01

    Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment.At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, "method of nitrogen acquisition" and "pattern of temporal development".Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t  DM ha -1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%-75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). Synthesis and applications . Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were

  11. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    International Nuclear Information System (INIS)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S.; Yamaguchi, M.

    2009-01-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  12. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2009-07-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  13. Development of Radioisotope Tracer Technology

    International Nuclear Information System (INIS)

    Jung, Sung Hee; Jin, Joon Ha; Kim, Jong Bum; Kim, Jin Seop; Kim, Jae Jo; Park, Soon Chul; Lim, Don Soon; Choi, Byung Jong; Jang, Dong Soon; Kim, Hye Sook

    2007-06-01

    The project is aimed to develop the radiotracer technology for process optimization and trouble-shooting to establish the environmental and industrial application of radiation and radioisotopes. The advanced equipment and software such as high speed data acquisition system, RTD model and high pressure injection tool have developed. Based on the various field application to the refinery/petrochemical industries, the developed technology was transfer to NDT company for commercial service. For the environmental application of radiotracer technology, injector, detector sled, core sampler, RI and GPS data logging system are developed and field tests were implemented successfully at Wolsung and Haeundae beach. Additionally tracer technology were also used for the performance test of the clarifier in a wastewater treatment plant and for the leak detection in reservoirs. From the experience of case studies on radiotracer experiment in waste water treatment facilities, 'The New Excellent Technology' is granted from the ministry of environment. For future technology, preliminary research for industrial gamma transmission and emission tomography which are new technology combined with radioisotope and image reconstruction are carried out

  14. Radioisotope tracer application in surface and groundwater flow measurements

    International Nuclear Information System (INIS)

    Monev, E.

    1983-01-01

    The ''peak to peak'' method for measurement of water flow with the use of radioactive tracer was investigated. The theoretical basis for this method has been established. The experiments in the open channel have shown the applicability of the method. Groundwater flow was studied by injection of radioactive tracer into the bore-hole followed by gamma-logging in three different time intervals. Interpretation of gamma lows in terms of filtration velocity in various depths proved to be possible

  15. Late Intensive Care Unit Admission in Liver Transplant Recipients: 10-Year Experience.

    Science.gov (United States)

    Atar, Funda; Gedik, Ender; Kaplan, Şerife; Zeyneloğlu, Pınar; Pirat, Arash; Haberal, Mehmet

    2015-11-01

    We evaluated late intensive care unit admission in liver transplant recipients to identify incidences and causes of acute respiratory failure in the postoperative period and to compare these results with results in patients who did not have acute respiratory failure. We retrospectively screened the data of 173 consecutive adult liver transplant recipients from January 2005 through March 2015 to identify patients with late admission (> 30 d posttransplant) to an intensive care unit. Patients were divided into 2 groups: patients with and without acute respiratory failure. Acute respiratory failure was defined as severe dyspnea, respiratory distress, decreased oxygen saturation, hypoxemia or hypercapnia on room air, or need for noninvasive or invasive mechanical ventilation. Demographic, laboratory, clinical, and respiratory data were collected. Model for End-Stage Liver Disease, Acute Physiology and Chronic Health Evaluation II, and Sequential Organ Failure Assessment scores; lengths of intensive care unit and hospital stays; and hospital mortality were assessed. Among 173 patients, 37 (21.4%) were admitted to an intensive care unit, including 22 (59.5%) with acute respiratory failure. The leading cause of acute respiratory failure was pneumonia (n = 19, 86.4%). Patients with acute respiratory failure had significantly lower levels of albumin before intensive care unit admission (P = .003). In patients with acute respiratory failure, severe sepsis and septic shock were more frequently observed and tracheotomy was more frequently performed (P = .041). Acute respiratory failure developed in 59.5% of liver transplant recipients with late intensive care unit admission. The leading cause was pneumonia, with this group of patients having higher requirements for invasive mechanical ventilation and tracheotomy, longer stays in an intensive care unit, and higher mortality.

  16. The international INTRAVAL project. Phase 2, working group 1 report. Flow and tracer experiments in unsaturated tuff and soil. Las Cruces trench and Apache Leap tuff studies

    International Nuclear Information System (INIS)

    Nicholson, T.J.; Guzman-Guzman, A.; Hills, R.; Rasmussen, T.C.

    1997-01-01

    The Working Group 1 final report summaries two test case studies, the Las Cruces Trench (LCT), and Apache Leap Tuff Site (ALTS) experiments. The objectives of these two field studies were to evaluate models for water flow and contaminant transport in unsaturated, heterogeneous soils and fractured tuff. The LCT experiments were specifically designed to test various deterministic and stochastic models of water flow and solute transport in heterogeneous, unsaturated soils. Experimental data from the first tow LCT experiments, and detailed field characterisation studies provided information for developing and calibrating the models. Experimental results from the third experiment were held confidential from the modellers, and were used for model comparison. Comparative analyses included: point comparisons of water content; predicted mean behavior for water flow; point comparisons of solute concentrations; and predicted mean behavior for tritium transport. These analyses indicated that no model, whether uniform or heterogeneous, proved superior. Since the INTRAVAL study, however, a new method has been developed for conditioning the hydraulic properties used for flow and transport modelling based on the initial field-measured water content distributions and a set of scale-mean hydraulic parameters. Very good matches between the observed and simulated flow and transport behavior were obtained using the conditioning procedure, without model calibration. The ALTS experiments were designed to evaluate characterisation methods and their associated conceptual models for coupled matrix-fracture continua over a range of scales (i.e., 2.5 centimeter rock samples; 10 centimeter cores; 1 meter block; and 30 meter boreholes). Within these spatial scales, laboratory and field tests were conducted for estimating pneumatic, thermal, hydraulic, and transport property values for different conceptual models. The analyses included testing of current conceptual, mathematical and physical

  17. Family members' experiences of being cared for by nurses and physicians in Norwegian intensive care units: a phenomenological hermeneutical study.

    Science.gov (United States)

    Frivold, Gro; Dale, Bjørg; Slettebø, Åshild

    2015-08-01

    When patients are admitted to intensive care units, families are affected. This study aimed to illuminate the meaning of being taken care of by nurses and physicians for relatives in Norwegian intensive care units. Thirteen relatives of critically ill patients treated in intensive care units in southern Norway were interviewed in autumn 2013. Interview data were analysed using a phenomenological hermeneutical method inspired by the philosopher Paul Ricoeur. Two main themes emerged: being in a receiving role and being in a participating role. The receiving role implies experiences of informational and supportive care from nurses and physicians. The participating role implies relatives' experiences of feeling included and being able to participate in caring activities and decision-making processes. The meaning of being a relative in ICU is experienced as being in a receiving role, and at the same time as being in a participating role. Quality in relations is described as crucial when relatives share their experiences of care by nurses and physicians in the ICU. Those who experienced informational and supportive care, and who had the ability to participate, expressed feelings of gratitude and confidence in the healthcare system. In contrast, those who did not experience such care, especially in terms of informational care expressed feelings of frustration, confusion and loss of confidence. However, patient treatment and care outweighed relatives' own feelings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Tracer airflow measurement system (TRAMS)

    Science.gov (United States)

    Wang, Duo [Albany, CA

    2007-04-24

    A method and apparatus for measuring fluid flow in a duct is disclosed. The invention uses a novel high velocity tracer injector system, an optional insertable folding mixing fan for homogenizing the tracer within the duct bulk fluid flow, and a perforated hose sampling system. A preferred embodiment uses CO.sub.2 as a tracer gas for measuring air flow in commercial and/or residential ducts. In extant commercial buildings, ducts not readily accessible by hanging ceilings may be drilled with readily plugged small diameter holes to allow for injection, optional mixing where desired using a novel insertable foldable mixing fan, and sampling hose.

  19. Reverse Transfer: Experiences of International Chinese Students in Intensive English Programs

    Science.gov (United States)

    Zhang, Yi

    2015-01-01

    An increasing number of international Chinese undergraduate students enrolled in United States.colleges and universities in the past few years. Many began their journey in an intensive English program of a four-year university due to lack of English proficiency. Instead of continuing their study at the same institution, a considerable number of…

  20. Clinical User Experience Testing of Ambient Lighting for Neonatal Intensive Care

    NARCIS (Netherlands)

    Simons, P.R.; Visser, H.M.

    2012-01-01

    Believed to the first application of its kind in the UK, Philips hasinstalled dynamic and ambient LED lighting in the recently extendedNeonatal Intensive Care Unit, (NICU), at St Michael’s Hospital, Bristol. The neonatal facility was redeveloped in late 2011 with a newICU built next to an existing

  1. Humiliation as an intense emotional experience: Evidence from the electro-encephalogram

    NARCIS (Netherlands)

    Otten, M.; Jonas, K.J.

    2014-01-01

    Humiliation, the emotion associated with being lowered in status in the eyes of others, seems to be very intense. As such, humiliation has been implied to play an important role in the escalation of inter-individual and inter-group conflict. Here, we provide the first clear empirical evidence that

  2. Creating a Transformational Learning Experience: Immersing Students in an Intensive Interdisciplinary Learning Environment

    Science.gov (United States)

    White, Shelley K.; Nitkin, Mindell Reiss

    2014-01-01

    The Simmons World Challenge is a unique, interdisciplinary program recently developed at Simmons College. It immerses students in an intensive winter-session course that challenges them to tackle a pressing social issue, such as poverty or hunger, and create actionable solutions to the problem. The program was conceived and designed to harness the…

  3. Saying It "More Intensely": Using Sensory Experience To Teach Poetry Writing.

    Science.gov (United States)

    Baart, Nicole

    2002-01-01

    Suggests the best way to help high school students write poetry is to bring them to memories that would stimulate the expression of everything more intensely. Describes four workshops that appeal to the senses: scent writing, taste writing, music writing, and sight writing. (RS)

  4. Temporal variance reverses the impact of high mean intensity of stress in climate change experiments.

    Science.gov (United States)

    Benedetti-Cecchi, Lisandro; Bertocci, Iacopo; Vaselli, Stefano; Maggi, Elena

    2006-10-01

    Extreme climate events produce simultaneous changes to the mean and to the variance of climatic variables over ecological time scales. While several studies have investigated how ecological systems respond to changes in mean values of climate variables, the combined effects of mean and variance are poorly understood. We examined the response of low-shore assemblages of algae and invertebrates of rocky seashores in the northwest Mediterranean to factorial manipulations of mean intensity and temporal variance of aerial exposure, a type of disturbance whose intensity and temporal patterning of occurrence are predicted to change with changing climate conditions. Effects of variance were often in the opposite direction of those elicited by changes in the mean. Increasing aerial exposure at regular intervals had negative effects both on diversity of assemblages and on percent cover of filamentous and coarsely branched algae, but greater temporal variance drastically reduced these effects. The opposite was observed for the abundance of barnacles and encrusting coralline algae, where high temporal variance of aerial exposure either reversed a positive effect of mean intensity (barnacles) or caused a negative effect that did not occur under low temporal variance (encrusting algae). These results provide the first experimental evidence that changes in mean intensity and temporal variance of climatic variables affect natural assemblages of species interactively, suggesting that high temporal variance may mitigate the ecological impacts of ongoing and predicted climate changes.

  5. Empowerment of Parents in the Intensive Care: A journey discovering parental experiences and satisfaction with care

    NARCIS (Netherlands)

    J.M. Latour (Jos)

    2011-01-01

    textabstractThe aim of this thesis – the EMPATHIC studies – was to develop and implement validated parent satisfaction questionnaires for pediatric and neonatal intensive care units. Part I presents the general introduction, which justifies the construction, validation, and utilization of

  6. Proceedings of the atmospheric tracers and tracer application workshop

    Energy Technology Data Exchange (ETDEWEB)

    Barr, S.; Gedayloo, T. (comps.)

    1979-12-01

    In addition to presentations by participating members a general discussion was held in order to summarize and outline the goals and objectives of the workshop. A number of new low level background tracers such as heavy methanes, perfluorocarbons, multiply labeled isotopes such as /sup 13/C/sup 18/O/sub 2/, helium 3, in addition to sample collection techniques and analytical methods for various tracers were discussed. This report is a summary of discussions and papers presented at this workshop.

  7. Proceedings of the atmospheric tracers and tracer application workshop

    International Nuclear Information System (INIS)

    Barr, S.; Gedayloo, T.

    1979-12-01

    In addition to presentations by participating members a general discussion was held in order to summarize and outline the goals and objectives of the workshop. A number of new low level background tracers such as heavy methanes, perfluorocarbons, multiply labeled isotopes such as 13 C 18 O 2 , helium 3, in addition to sample collection techniques and analytical methods for various tracers were discussed. This report is a summary of discussions and papers presented at this workshop

  8. Tracer Migration in a Radially Divergent Flow Field: Longitudinal Dispersivity and Anionic Tracer Retardation

    Energy Technology Data Exchange (ETDEWEB)

    Seaman, J.C., P.M. Bertsch, M. Wilson, J. Singer, F. Majs and S.A. Aburime

    2007-01-01

    Hydrodynamic dispersion, the combined effects of chemical diffusion and differences in solute path length and flow velocity, is an important factor controlling contaminant migration in the subsurface environment. However, few comprehensive three-dimensional datasets exist for critically evaluating the impact of travel distance and site heterogeneity on solute dispersion, and the conservative nature of several commonly used groundwater tracers is still in question. Therefore, we conducted a series of field-scale experiments using tritiated water ({sup 3}H{sup 1}HO), bromide (Br{sup -}), and two fluorobenzoates (2,4 Di-FBA, 2,6 Di-FBA) as tracers in the water-table aquifer on the USDOE's Savannah River Site (SRS), located on the upper Atlantic Coastal Plain. For each experiment, tracer-free groundwater was injected for approximately 24 h (56.7 L min{sup -1}) to establish a steady-state forced radial gradient before the introduction of a tracer pulse. After the tracer pulse, which lasted from 256 to 560 min, the forced gradient was maintained throughout the experiment using nonlabeled groundwater. Tracer migration was monitored using six multilevel monitoring wells, radially spaced at approximate distances of 2.0, 3.0, and 4.5 m from the central injection well. Each sampling well was further divided into three discrete sampling depths that were pumped continuously ({approx}0.1 L min{sup -1}) throughout the course of the experiments. Longitudinal dispersivity ({alpha}{sub L}) and travel times for {sup 3}H{sup 1}HO breakthrough were estimated by fitting the field data to analytical approximations of the advection-dispersion equation (ADE) for uniform and radial flow conditions. Dispersivity varied greatly between wells located at similar transport distances and even between zones within a given well, which we attributed to variability in the hydraulic conductivity at the study site. The radial flow equation generally described tritium breakthrough better than the

  9. A trajectory towards partnership in care--Patient experiences of autonomy in intensive care: A qualitative study.

    Science.gov (United States)

    Lindberg, Catharina; Sivberg, Bengt; Willman, Ania; Fagerström, Cecilia

    2015-10-01

    The aim of this study was to describe and elucidate patient experiences of autonomy in an intensive care context from a caring perspective. Patients in intensive care units (ICUs) are critically ill and in a dependent and vulnerable position. There is thus a risk of staff taking command not only of the patients' vital functions but also of their decision-making. A qualitative design was selected. Individual interviews were conducted with 11 adult patients with an intensive care episode of two days or more at six Swedish ICUs. The data were analysed using Inductive Content Analysis. Patient autonomy in intensive care was shown to be 'A trajectory towards partnership in care depending on state of health and mutual understanding'. It was experienced through acknowledged dependence, being recognised as a person, invited participation and becoming a co-partner in care. Patients in need of intensive care wanted to be involved in making decisions about their care as this creates a trusting and healthy care environment. Greater awareness is required about the ICU patient not only being a passive care recipient but also an active agent and where involvement in decision-making and participation in care are crucial. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Acute Respiratory Failure in Renal Transplant Recipients: A Single Intensive Care Unit Experience.

    Science.gov (United States)

    Ulas, Aydin; Kaplan, Serife; Zeyneloglu, Pinar; Torgay, Adnan; Pirat, Arash; Haberal, Mehmet

    2015-11-01

    Frequency of pulmonary complications after renal transplant has been reported to range from 3% to 17%. The objective of this study was to evaluate renal transplant recipients admitted to an intensive care unit to identify incidence and cause of acute respiratory failure in the postoperative period and compare clinical features and outcomes between those with and without acute respiratory failure. We retrospectively screened the data of 540 consecutive adult renal transplant recipients who received their grafts at a single transplant center and included those patients admitted to an intensive care unit during this period for this study. Acute respiratory failure was defined as severe dyspnea, respiratory distress, decreased oxygen saturation, hypoxemia or hypercapnia on room air, or requirement of noninvasive or invasive mechanical ventilation. Among the 540 adult renal transplant recipients, 55 (10.7%) were admitted to an intensive care unit, including 26 (47.3%) admitted for acute respiratory failure. Median time from transplant to intensive care unit admission was 10 months (range, 0-67 mo). The leading causes of acute respiratory failure were bacterial pneumonia (56%) and cardiogenic pulmonary edema (44%). Mean partial pressure of arterial oxygen to fractional inspired oxygen ratio was 174 ± 59, invasive mechanical ventilation was used in 13 patients (50%), and noninvasive mechanical ventilation was used in 8 patients (31%). The overall mortality was 16.4%. Acute respiratory failure was the reason for intensive care unit admission in almost half of our renal transplant recipients. Main causes of acute respiratory failure were bacterial pneumonia and cardiogenic pulmonary edema. Mortality of patients admitted for acute respiratory failure was similar to those without acute respiratory failure.

  11. Tracer studies with aortic infusion result in improper tracer distribution

    International Nuclear Information System (INIS)

    Wisneski, J.A.; Brooks, G.A.; Neese, R.A.; Stanley, W.C.; Morris, D.L.; Gertz, E.W.

    1986-01-01

    It has been suggested that lactate turnover can be accurately assessed by infusing radioactive lactate tracer into the aorta and sampling blood in the vena cava. However, there may be streaming of newly infused tracer in the aorta, resulting in a nonuniform arterial specific activity (SA). Furthermore vena caval blood may not be representative of mixed venous blood. The authors examined this problem in 7 anesthetized dogs with sampling catheters in the pulmonary (PA), carotid (CA), and femoral (FA) arteries, and the superior (SVC) and inferior (IVC) vena cavi. [1- 14 C]lactate was continuously infused into the left ventricle through a catheter introduced through the femoral artery. The same SA (dpm/μmol) was found in the CA and FA, indicating adequate mixing of newly infused tracer with trace. Three dogs showed differences between SVC, IVC and PA, suggesting a mixed venous sample can not be obtained from the VC. When the catheter was moved into the aorta, wide differences in SA appeared between the CA and FA, clearly reflecting streaming of tracer. These differences also appeared in the SVC and IVC. In conclusion, adequate mixing does not occur between tracer and trace in arterial blood with aortic infusion. Further, VC sampling will not give a consistent mixed venous SA. Therefore, for practical reasons, aortic tracer infusion with vena caval sampling will lead to erroneous turnover values

  12. Intensity ramp-up: 2011 experience - Limitations, mitigation, risks, strategy, pushing it in 2012, 1380 in 3 weeks?

    CERN Document Server

    Zerlauth, M; Wenninger, J

    2012-01-01

    This paper will discuss the experience with ramping up the beam intensities in the early days of the 2011 run and after the subsequent technical stops. Weak points and limitations are being identified and their possible mitigations evaluated. In view of the risks and drawbacks of a too aggressive approach, possible improvements of the applied strategy whilst maintaining the required validation points for the various equipment and machine protection systems (MPS) are being discussed.

  13. Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends

    Science.gov (United States)

    Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

    2011-01-01

    X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

  14. On the behavior of ion implanted silicon strip detectors in high intensity low energy heavy ion beam experiments

    CERN Document Server

    Bradfield, W; Parker, P D; Visser, D W

    2002-01-01

    In a recent investigation of the development of leakage currents in Silicon Strip Detectors used in experiments with high intensity stable beams, anomalous behavior was observed. Over a very short period of time the leakage current rose to levels that could be damaging to the detectors. A discussion of this evidence and how the problem was solved, with a viable model, will be given, leading to guidelines for use of such detectors in a stable beam environment.

  15. Compartmental modeling and tracer kinetics

    CERN Document Server

    Anderson, David H

    1983-01-01

    This monograph is concerned with mathematical aspects of compartmental an­ alysis. In particular, linear models are closely analyzed since they are fully justifiable as an investigative tool in tracer experiments. The objective of the monograph is to bring the reader up to date on some of the current mathematical prob­ lems of interest in compartmental analysis. This is accomplished by reviewing mathematical developments in the literature, especially over the last 10-15 years, and by presenting some new thoughts and directions for future mathematical research. These notes started as a series of lectures that I gave while visiting with the Division of Applied ~1athematics, Brown University, 1979, and have developed in­ to this collection of articles aimed at the reader with a beginning graduate level background in mathematics. The text can be used as a self-paced reading course. With this in mind, exercises have been appropriately placed throughout the notes. As an aid in reading the material, the e~d of a ...

  16. Student experiences in the neonatal intensive care unit: addendum to neonatal physical therapy competencies and clinical training models.

    Science.gov (United States)

    Rapport, Mary Jane; Sweeney, Jane K; Dannemiller, Lisa; Heriza, Carolyn B

    2010-01-01

    To describe the appropriate experience for entry-level physical therapist students in the neonatal intensive care unit (NICU). Care for infants in the NICU represents a subspecialty within pediatric physical therapy delivered in a very complex environment. Recommendations for designing student educational experiences related to the NICU are provided. Supervised observation is the appropriate level of NICU experience for physical therapy students. Observation in the NICU cannot be used to demonstrate entry-level clinical competency defined as managing 100% patient caseload in the setting. Additional closely supervised experiences with older, less fragile infants and children in neonatal follow-up clinics and pediatric wards can provide opportunities for entry-level physical therapist students interested in pediatrics to participate in examination and intervention with young children.

  17. Evaluation of Medicare's Intensive Behavioral Therapy for Obesity: the BieneStar Experience.

    Science.gov (United States)

    Treviño, Roberto P; Piña, Christina; Fuentes, Jesús Cuéllar; Nuñez, Melissa

    2018-04-01

    In 2011, the Centers for Medicare and Medicaid Services began to reimburse primary care providers for intensive behavior therapy for obesity. This study evaluated a Centers for Medicare and Medicaid Services intensive behavior therapy for obesity program as implemented in primary care clinics. Data for this retrospective cohort study were obtained between May 2012 and February 2015 and statistical analysis was performed in 2017. The sample included 643 participants who attended at least one BieneStar intensive behavior therapy for obesity program session. The primary outcome was weight, and covariates were number of sessions, age, race/ethnicity, diagnosis of hypertension and diabetes, and type of health insurance. Of 643 participants that initiated the BieneStar program, 641 had complete data. The median reduction in weight of participants was as follows: those who attended fewer than four sessions, 0 kg (95% CI=0, 0.11 kg); between four and eight sessions, 1.1 kg (95% CI=0.86, 1.59 kg); and more than eight sessions 3.7 kg (95% CI=3.36, 4.55 kg). Medians of weight were significantly different between each classification of session numbers (pBieneStar program showed that the weight of participants decreased as they attended more sessions. Further studies are needed to determine if these results can be reproduced in other office-based primary care clinics and the program's impact on chronic disease. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Redesigning TRACER trial after TRITON.

    Science.gov (United States)

    Serebruany, Victor L

    2015-10-15

    Designing of smart clinical trials is critical for regulatory approval and future drug utilization. Importantly, trial design should be reconsidered if the interim analyses suggest unexpected harm, or conflicting results were yielded from the other trials within the same therapeutic area. With regard to antiplatelet agents, the perfect example is redesigning of the ongoing PRoFESS trial by eliminating aspirin from clopidogrel arm after the earlier MATCH trial results became available. The goal was to aseess the unchanged TRACER trial design in light of the evidence yielded from the earlier completed TRITON trial. TRACER was designed as a triple versus dual antiplatelet trial in NSTEMI patients with no previous long-term outcome data supporting such aggressive strategy. TRITON data represented dual versus dual antiplatelet therapy, and became available before TRACER enrollment starts revealing prasugrel front-loaded early vascular benefit predominantly in STEMI patients with the growing over time bleeding and cancer risks. Moreover, large prasugrel NSTEMI TRITON cohort exhibited trend towards excess mortality in experimental arm warning against aggressive TRACER design. The long-term TRITON results in general, and especially in the NSTEMI patients challenge unchanged TRACER trial design. Applying dual, rather than triple antiplatelet therapy protocol modification should be considered in TRACER to minimize bleeding, cancer, and non-cardiovascular death risks. Copyright © 2015. Published by Elsevier Ireland Ltd.

  19. Tracer transport in fractured rocks

    International Nuclear Information System (INIS)

    Tsang, C.F.; Tsang, Y.W.; Hale, F.V.

    1988-07-01

    Recent interest in the safety of toxic waste underground disposal and nuclear waste geologic repositories has motivated many studies of tracer transport in fractured media. Fractures occur in most geologic formations and introduce a high degree of heterogeneity. Within each fracture, the aperture is not constant in value but strongly varying. Thus for such media, tracer tends to flow through preferred flowpaths or channels within the fractures. Along each of these channels, the aperture is also strongly varying. A detailed analysis is carried out on a 2D single fracture with variable apertures and the flow through channels is demonstrated. The channels defined this way are not rigidly set pathways for tracer transport, but are the preferred flow paths in the sense of stream-tubes in the potential theory. It is shown that such variable-aperture channels can be characterized by an aperture probability distribution function, and not by the exact deterministic geometric locations. We also demonstrate that the 2D tracer transport in a fracture can be calculated by a model of a system of 1D channels characterized by this distribution function only. Due to the channeling character of tracer transport in fractured rock, random point measurements of tracer breakthrough curves may give results with a wide spread in value due to statistical fluctuations. The present paper suggests that such a wide spread can probably be greatly reduced by making line/areal (or multiple) measurements covering a few spatial correlation lengths. 13 refs., 11 figs., 1 tab

  20. Characteristics and Outcomes of Intensive Care Unit Survivors: Experience of a Multidisciplinary Outpatient Clinic in a Teaching Hospital

    Directory of Open Access Journals (Sweden)

    Péricles A.D. Duarte

    Full Text Available OBJECTIVES: To describe the experience of an outpatient clinic with the multidisciplinary evaluation of intensive care unit survivors and to analyze their social, psychological, and physical characteristics in a low-income population and a developing country. METHODS: Retrospective cohort study. Adult survivors from a general intensive care unit were evaluated three months after discharge in a post-intensive care unit outpatient multidisciplinary clinic over a period of 6 years (2008-2014 in a University Hospital in southern Brazil. RESULTS: A total of 688 out of 1945 intensive care unit survivors received care at the clinic. Of these, 45.2% had psychological disorders (particularly depression, 49.0% had respiratory impairments (abnormal spirometry, and 24.6% had moderate to intense dyspnea during daily life activities. Patients experienced weight loss during hospitalization (mean=11.7% but good recovery after discharge (mean gain=9.1%, and 94.6% were receiving nutrition orally. One-third of patients showed a reduction of peripheral muscular strength, and 5.7% had moderate to severe tetraparesis or tetraplegia. There was a significant impairment in quality of life (SF-36, particularly in the physical and emotional aspects and in functional capacity. The economic impacts on the affected families, which were mostly low-income families, were considerable. Most patients did not have full access to rehabilitation services, even though half of the families were receiving financial support from the government. CONCLUSIONS: A significant number of intensive care unit survivors evaluated 3 months after discharge had psychological, respiratory, motor, and socioeconomic problems; these findings highlight that strategies aimed to assist critically ill patients should be extended to the post-hospitalization period and that this problem is particularly important in low-income populations.

  1. Tracer techniques in plant breeding programmes

    International Nuclear Information System (INIS)

    Lupton, F.G.H.

    1975-01-01

    Tracer techniques may be used as a tool in plant breeding programmes either to help in the choice of parental combinations with complementary advantages or in the selection of desirable plants within the segregating populations. The second application is, however, of little practical application as the techniques involved are mostly too tedious to be used on the large populations with which the plant breeder must deal, and frequently involve unacceptable destructive sampling of his material. The physiological analysis of potential parents is of considerable importance, particularly in the improvement of crops to be grown in more fully developed countries with advanced agricultural systems. Techniques using radioactive tracers and radiation-emitting sources such as the neutron probe have played a considerable part in this work. They have been used by cereal breeders to measure photosynthesis either of individual leaves, or of undisturbed crop canopies, and by breeders of many crops in the study of the translocation of the products of photosynthesis within the plant. They have also been used in studies of the effects of plant diseases on translocation patterns, thus identifying limiting factors for which the breeder should select. Radioactive tracers have also been used in estimating varietal differences in root growth and distribution, but the results obtained from such experiments have indicated that environmental differences are greater than those between genotypes. Differences in water uptake have, however, been demonstrated using the neutron probe, though these differences appear to be much influenced by differences in the water economy of the aerial parts. (author)

  2. Belowground carbon sources and fine root turnover times using 13C tracer at the conclusion of a long-term FACE experiment

    Science.gov (United States)

    Lynch, D. J.; Matamala, R.; Norby, R.; Iversen, C.; Gonzalez-Meler, M. A.

    2011-12-01

    Estimates of carbon budgets require accurate approximations of fine root production and turnover. Current published estimates of root carbon turnover vary more than five-fold, with large differences between isotope-derived estimates, minirhizotron studies or other approaches. Variations in residence times between root structural and reserve C, root orders and new photosynthate to support root function have been shown independently, but have not been yet reconciled in a single study. Taking advantage of the conclusion of the long-term FACE experiment at Oak Ridge National Laboratory, we track the whole ecosystem isotope relaxation in fine root pools (Liquidambar styraciflua, and to identify carbon sources for new root growth and for energy metabolism. We sampled intact and in-growth root cores at regular (minimum time was monthly) intervals in 2010 and at several intervals in 2011. Additionally, fine roots and soils were incubated from three sampling periods each from 2010 and 2011 for measurement of the isotopic signature of respired CO2. Our results show a residence time of carbon in fine roots consistent with previous stable isotope reports for this species, with about 20% of structural C replaced after one full growing season. In contrast, all new root growth (evidenced from in-growth cores) was supported by new photosynthate, except for some storage carbon used very early in the growing season. Carbon used for energy metabolism in roots exclusively originated from new photosynthate during all measurement periods. Our results confirm heterogeneity of C pools in existing and new roots and the relatively long residence time of structural C in existing fine roots.

  3. Muon Intensity Increase by Wedge Absorbers for Low-E Muon Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, D. V. [Fermilab; Stratakis, D. [Fermilab; Bradley, J. [Fermilab

    2017-09-01

    Low energy muon experiments such as mu2e and g-2 have a limited energy spread acceptance. Following techniques developed in muon cooling studies and the MICE experiment, the number of muons within the desired energy spread can be increased by the matched use of wedge absorbers. More generally, the phase space of muon beams can be manipulated by absorbers in beam transport lines. Applications with simulation results are presented.

  4. The End-of-Life Care Experiences of Relatives of Brain Dead Intensive Care Patients

    OpenAIRE

    Lloyd-Williams, Mari; Morton, Juliet; Peters, Sarah

    2009-01-01

    Brain death is a traumatic and sudden event following a severe injury to the brain. Most patients with brain death spend the last days of life in an intensive care unit (ICU), where some families will be approached to ask for organ donation. This qualitative study was carried out with relatives of patients who had died of brain death in an ICU; all relatives were interviewed six months after the death. Twenty ICUs were recruited for this study. The next of kin of 130 patients who died during ...

  5. Experiments on the interaction of intense femtosecond radiation with dense plasmas. Final report

    International Nuclear Information System (INIS)

    Rhodes, C.K.

    1996-01-01

    An upgraded KrF * (248 nm) system producing a pulse energy of ∼ 400 mJ, a pulse width of ∼ 220 fs, and focal intensities above 10 19 W/cm 2 , has been constructed, tested, operated, and used in experimental studies. The spatial morphology of channeled radiation in plasmas has been measured with a spatial resolution of ∼ 30 μm and damage studies of fused silica indicate that femtosecond (200 - 300 fs) 248 nm radiation has a damage limit not exceeding ∼ 50 GW/cm 2 , an unfavorably low level. 2 figs

  6. Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    Petrignani, Annemieke; Berg, Max H.; Grussie, Florian; Wolf, Andreas [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Mizus, Irina I.; Zobov, Nikolai F. [Institute of Applied Physics, Russian Academy of Science, Ulyanov Street 46, Nizhnii Novgorod 603950 (Russian Federation); Polyansky, Oleg L. [Institute of Applied Physics, Russian Academy of Science, Ulyanov Street 46, Nizhnii Novgorod 603950 (Russian Federation); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Tennyson, Jonathan [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Pavanello, Michele [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Adamowicz, Ludwik [Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721 (United States)

    2014-12-28

    The visible spectrum of H{sub 3}{sup +} is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H{sub 3}{sup +} up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H{sub 3}{sup +} and found to be in excellent agreement, even in the region where states have been classified as chaotic.

  7. Model experiment to study sonic boom propagation through turbulence. Part II. Effect of turbulence intensity and propagation distance through turbulence.

    Science.gov (United States)

    Lipkens, B; Blackstock, D T

    1998-09-01

    A model experiment was reported to be successful in simulating the propagation of sonic booms through a turbulent atmosphere [B. Lipkens and D. T. Blackstock, J. Acoust. Soc. Am. 103, 148-158 (1998)]. In this study the effect on N wave characteristics of turbulence intensity and propagation distance through turbulence are investigated. The main parameters of interest are the rise time and the peak pressure. The effect of turbulence intensity and propagation distance is to flatten the rise time and peak pressure distributions. Rise time and peak pressure distributions always have positive skewness after propagation through turbulence. Average rise time grows with turbulence intensity and propagation distance. The scattering of rise time data is one-sided, i.e., rise times are almost always increased by turbulence. Average peak pressure decreases slowly with turbulence intensity and propagation distance. For the reported data a threefold increase in average rise time is observed and a maximum decrease of about 20% in average peak pressure. Rise times more than ten times that of the no turbulence value are observed. At most, the maximum peak pressure doubles after propagation through turbulence, and the minimum peak pressure values are about one-half the no-turbulence values. Rounded waveforms are always more common than peaked waveforms.

  8. Environment tracers application to groundwater circulation assessment in an alluvial aquifer in Central Italy

    Science.gov (United States)

    Sappa, Giuseppe; Barbieri, Maurizio; Vitale, Stefania

    2017-04-01

    Groundwater vulnerability assessment is an important tool in order to plan any groundwater protection strategy. The aim of this study is to experiment a specific approach to give a conceptual model about groundwater circulation characterization. This approach has been applied to a suspected contaminated site in a large alluvial plan, made of sediments coming from weathered volcanic rocks, laying on marine sediments, where more than thirty years ago had been built a very important urban waste solid landfill. In referring to this case history it has been pointed out the importance of natural chemical interaction between ground water and rock mass, especially when pyroclastic origin sediments are involved. The landfill had been isolated from the surrounding environment, especially to protect aquifers, by a waterproof diaphragm This land is characterised by intensive agricultural and industrial activities (oil refineries, medical waste incinerators, concrete production, tar factory). The study will highlight the importance of environmental tracers which provide information about the flow and mixing processes of water coming from different sources. They are also useful to point out directions of groundwater flow and to determine origin Environmental tracers are natural chemical and isotopic substances that can be measured in groundwater and used to understand hydrologic properties of aquifers. They may be input into the hydrological system from the atmosphere at recharge and/or are added/lost/exchanged inherently as waters flow over and through materials. Variations in their chemical abundances and isotopic compositions can be used as tracers to determine sources (provenance), pathways (of reaction or interaction) and also timescales (dating) of environmental processes. In combination with these, the basic idea is to use. In this case enviromental tracers have been integrated by temperature and electric conductivity logs, to better investigate different levels of faster

  9. Measurement of open streams by using tracers

    International Nuclear Information System (INIS)

    Ramos, German F.; Tarquino, W.; Curcuy, H.; Orozco, C.

    1999-01-01

    This paper presents an intercomparison study to be carried out between flux measurements by using tracers and moulinet. This intercomparison is scheduled to be performed at the measurement station belonging to the National Service of Meteorology and Hydrology (SENAMHI). Two techniques of tracer dilution are outstanded: total evaluation with tracer punctual injection and punctual evaluation with tracer continuous injection. Total evaluation with tracer punctual injection has been used since this technique is considered to be more suitable for hydrology purposes

  10. An experimental study of tracers for labelling of injection gas in oil reservoirs

    International Nuclear Information System (INIS)

    Dugstad, Oe.

    1992-01-01

    This work demonstrates the feasibility of the PMCP and PMCH as tracers in field experiments. These compounds have properties which make them as well suited for well to well studies as the more common tracers CH 3 T and 85 Kr. In an injection project carried out at the Gullfaks field in the North Sea the two PFCs verified communication between wells. This implies communication between different geological layers in the reservoir and also communication across faults within the same layers. Laboratory studies carried out have focused on the retention of the tracers in dynamic flooding experiments under conditions comparable with those in the petroleum reservoirs. Simultaneous injection of a variety of tracers has shown individual variations in tracer retention which are caused by important reservoir parameters as fluid saturation and rock properties. By proper design of field injection programs the tracers response may therefore be used to estimate fluid saturation if actual rock properties are known. 45 refs., 20 figs., 13 tabs

  11. A 10-year experience with major burns from a non-burn intensive care unit.

    Science.gov (United States)

    Ibarra Estrada, Miguel Ángel; Chávez Peña, Quetzalcóatl; García Guardado, Dante Ismael; López Pulgarín, José Arnulfo; Aguirre Avalos, Guadalupe; Corona Jiménez, Federico

    2014-09-01

    The aim of this study was to review clinical data and outcomes of patients with burns in a Mexican non-burn intensive care unit (ICU). We did a retrospective analysis of our single-centre database of burn patients admitted to the ICU in the Hospital Civil Fray Antonio Alcalde (University Hospital). The sample was divided for analysis into two groups according to the outcome 'death' or 'discharge' from ICU. Overall mortality was 58.2%, without a decreasing trend in mortality rates through the years. We identified the presence of third-degree burns (odds ratio (OR) 1.5, p=0.003), and >49% total burned surface area (TBSA; OR 3.3, p≤0.001) was associated with mortality. Mean age was higher in deceased patients (38.2 years vs. 31.3 years, p=0.003) as was the TBSA (62.8% vs. 36.4%, p≤0.001). At multivariate analysis, inhalation injury was not associated with increased mortality, but it was with more mechanical ventilation days. Early surgical debridement/cleansing was performed in most patients; however, the mean of the procedures was 1.7 per patient in both groups. We identified significant factors associated with mortality. These variables and prognosis from non-burn ICUs differ broadly compared with burn intensive care units (BICUs); thus, more structured, multidisciplinary and specialised treatment strategies are still needed. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  12. The Effect of Previous Co-Worker Experience on the Survival of Knowledge Intensive Start-Ups

    DEFF Research Database (Denmark)

    Timmermans, Bram

    The aim of the paper is to investigate the effect of previous co-worker experience on the survival of knowledge intensive start-ups. For the empirical analysis I use the Danish Integrated Database of Labor Market Research (IDA). This longitudinal employer-employee database allows me to identify co-worker...... experience among all members of the firm. In addition, I will make a distinction between ordinary start-ups and entrepreneurial spin-offs. The results show that previous co-worker experience has a positive effect on new firm survival. This effect appears to be valid predominantly for ordinary start-ups than...

  13. Natural stream flow-rates measurements by tracer techniques

    International Nuclear Information System (INIS)

    Cuellar Mansilla, J.

    1982-01-01

    This paper presents the study of the precision obtained measuring the natural stream flow rates by tracer techniques, especially when the system presents a great slope and a bed constituted by large and extended particle size. The experiences were realized in laboratory pilot channels with flow-rates between 15 and 130 [1/s]; and in natural streams with flow-rates from 1 to 25 m 3 /s. Tracer used were In-133m and Br-82 for laboratory and field measurements respectively. In both cases the tracer was injected as a pulse and its dilution measured collecting samples in the measured section, at constant flow-rates, of 5[1] in laboratory experiences and 60[1] of water in field experiences. Precisions obtained at a 95% confidence level were about 2% for laboratory and 3% for field. (I.V.)

  14. Analysis of induced stress on materials exposed to laser-plasma radiation during high-intensity laser experiments

    Science.gov (United States)

    Scisciò, M.; Barberio, M.; Liberatore, C.; Veltri, S.; Laramée, A.; Palumbo, L.; Legaré, F.; Antici, P.

    2017-11-01

    In this work, we investigate the damage produced in materials when exposed to a laser-generated plasma. The plasma was generated by interaction of a high-intensity laser with Oxygen. We demonstrate that the stress induced on the target surface of a Tantalum target (typical materials used as Plasma Facing Material) after 10 h of plasma exposure is equivalent to the stress induced during 1 h of conventional laser ablation using a pulsed 0.5 J laser. In both cases we obtain a surface erosion in the tens of μm, and a change in the surface roughness in the tens of nm for the stressed materials. The erosion rate of 1 nm/s, explained in terms of surface fragmentation at thermodynamic equilibrium, generates a slow damage to the materials exposed to the plasma. Our method allows indicating safety parameters for the maintenance of materials used in high-intensity laser experiments.

  15. Determination of the self purification of streams using tracers

    International Nuclear Information System (INIS)

    Salviano, J.S.

    1982-04-01

    A methodology for the 'in situ' evaluation of the self purification of streams is discussed. It consists of the simultaneous injection of two tracers into the stream. One of the tracers is oxidized by biochemical processes. It can be either artificially supplied to the stream or a naturally present component can be used. This tracer is used for the determination of the self purification parameters. The other tracer is conservative and allows for the hydrodynamic effects. Tests have been carried out in two streams with quite different hydrodynamic and physicochemical conditions. In the first stream, with a flow-rate of about 0.9 m 3 /s, urea was used as the nonconservative tracer. In the other stream, which had a flow-rate of about 5 m 3 /s, only a radioactive tracer has been used, and the rate of biochemical oxidation has been determined from BOD measurements. Calculations have been implemented on a digital computer. In both cases it was found that the reoxygenation rate is more conveniently determined by empirical formulas. Results from both tests have been deemed realistic by comparison with similar experiments. (Author) [pt

  16. Quantifying solute transport processes: are chemically "conservative" tracers electrically conservative?

    Science.gov (United States)

    Singha, Kamini; Li, Li; Day-Lewis, Frederick D.; Regberg, Aaron B.

    2012-01-01

    The concept of a nonreactive or conservative tracer, commonly invoked in investigations of solute transport, requires additional study in the context of electrical geophysical monitoring. Tracers that are commonly considered conservative may undergo reactive processes, such as ion exchange, thus changing the aqueous composition of the system. As a result, the measured electrical conductivity may reflect not only solute transport but also reactive processes. We have evaluated the impacts of ion exchange reactions, rate-limited mass transfer, and surface conduction on quantifying tracer mass, mean arrival time, and temporal variance in laboratory-scale column experiments. Numerical examples showed that (1) ion exchange can lead to resistivity-estimated tracer mass, velocity, and dispersivity that may be inaccurate; (2) mass transfer leads to an overestimate in the mobile tracer mass and an underestimate in velocity when using electrical methods; and (3) surface conductance does not notably affect estimated moments when high-concentration tracers are used, although this phenomenon may be important at low concentrations or in sediments with high and/or spatially variable cation-exchange capacity. In all cases, colocated groundwater concentration measurements are of high importance for interpreting geophysical data with respect to the controlling transport processes of interest.

  17. Low intensity interventions for Obsessive-Compulsive Disorder (OCD): a qualitative study of mental health practitioner experiences.

    Science.gov (United States)

    Gellatly, Judith; Pedley, Rebecca; Molloy, Christine; Butler, Jennifer; Lovell, Karina; Bee, Penny

    2017-02-22

    Obsessive-compulsive disorder (OCD) is a debilitating mental health disorder that can substantially impact upon quality of life and everyday functioning. Guidelines recommend pharmacological and psychological treatments, using a cognitive behaviour therapy approach (CBT) including exposure and response prevention, but access has generally been poor. Low intensity psychological interventions have been advocated. The evidence base for these interventions is emerging but there is a paucity of information regarding practitioners' perceptions and experiences of supporting individuals with OCD using this approach. Qualitative interviews were undertaken with psychological wellbeing practitioners (PWPs) (n = 20) delivering low intensity psychological interventions for adults with OCD within the context of a large pragmatic effectiveness trial. Interviews explored the feasibility and acceptability of delivering two interventions; guided self-help and supported computerised cognitive behaviour therapy (cCBT), within Improving Access to Psychological Therapies (IAPT) services in NHS Trusts. Interviews were recorded with consent, transcribed and analysed using thematic analysis. PWPs acknowledged the benefits of low intensity psychological interventions for individuals experiencing OCD symptoms on an individual and population level. Offering low intensity support provided was perceived to have the opportunity to overcome existing service barriers to access treatment, improve patient choice and flexibility. Professional and service relevant issues were also recognised including self-beliefs about supporting people with OCD and personal training needs. Challenges to implementation were recognised in relation to practitioner resistance and intervention delivery technical complications. This study has provided insight into the implementation of new low intensity approaches to the management of OCD within existing mental health services. Benefits from a practitioner, service

  18. The Energy Costs of Prematurity and the Neonatal Intensive Care Unit (NICU Experience

    Directory of Open Access Journals (Sweden)

    John B. C. Tan

    2018-03-01

    Full Text Available Premature neonates are in an energy deficient state due to (1 oxygen desaturation and hypoxia events, (2 painful and stressful stimuli, (3 illness, and (4 neurodevelopmental energy requirements. Failure to correct energy deficiency in premature infants may lead to adverse effects such as neurodevelopmental delay and negative long-term metabolic and cardiovascular outcomes. The effects of energy dysregulation and the challenges that clinicians in the Neonatal Intensive Care Unit (NICU face in meeting the premature infant’s metabolic demands are discussed. Specifically, the focus is on the effects of pain and stress on energy homeostasis. Energy deficiency is a complex problem and requires a multi-faceted solution to promote optimum development of premature infants.

  19. MS1 Peptide Ion Intensity Chromatograms in MS2 (SWATH) Data Independent Acquisitions. Improving Post Acquisition Analysis of Proteomic Experiments*

    Science.gov (United States)

    Rardin, Matthew J.; Schilling, Birgit; Cheng, Lin-Yang; MacLean, Brendan X.; Sorensen, Dylan J.; Sahu, Alexandria K.; MacCoss, Michael J.; Vitek, Olga; Gibson, Bradford W.

    2015-01-01

    Quantitative analysis of discovery-based proteomic workflows now relies on high-throughput large-scale methods for identification and quantitation of proteins and post-translational modifications. Advancements in label-free quantitative techniques, using either data-dependent or data-independent mass spectrometric acquisitions, have coincided with improved instrumentation featuring greater precision, increased mass accuracy, and faster scan speeds. We recently reported on a new quantitative method called MS1 Filtering (Schilling et al. (2012) Mol. Cell. Proteomics 11, 202–214) for processing data-independent MS1 ion intensity chromatograms from peptide analytes using the Skyline software platform. In contrast, data-independent acquisitions from MS2 scans, or SWATH, can quantify all fragment ion intensities when reference spectra are available. As each SWATH acquisition cycle typically contains an MS1 scan, these two independent label-free quantitative approaches can be acquired in a single experiment. Here, we have expanded the capability of Skyline to extract both MS1 and MS2 ion intensity chromatograms from a single SWATH data-independent acquisition in an Integrated Dual Scan Analysis approach. The performance of both MS1 and MS2 data was examined in simple and complex samples using standard concentration curves. Cases of interferences in MS1 and MS2 ion intensity data were assessed, as were the differentiation and quantitation of phosphopeptide isomers in MS2 scan data. In addition, we demonstrated an approach for optimization of SWATH m/z window sizes to reduce interferences using MS1 scans as a guide. Finally, a correlation analysis was performed on both MS1 and MS2 ion intensity data obtained from SWATH acquisitions on a complex mixture using a linear model that automatically removes signals containing interferences. This work demonstrates the practical advantages of properly acquiring and processing MS1 precursor data in addition to MS2 fragment ion

  20. MS1 Peptide Ion Intensity Chromatograms in MS2 (SWATH) Data Independent Acquisitions. Improving Post Acquisition Analysis of Proteomic Experiments.

    Science.gov (United States)

    Rardin, Matthew J; Schilling, Birgit; Cheng, Lin-Yang; MacLean, Brendan X; Sorensen, Dylan J; Sahu, Alexandria K; MacCoss, Michael J; Vitek, Olga; Gibson, Bradford W

    2015-09-01

    Quantitative analysis of discovery-based proteomic workflows now relies on high-throughput large-scale methods for identification and quantitation of proteins and post-translational modifications. Advancements in label-free quantitative techniques, using either data-dependent or data-independent mass spectrometric acquisitions, have coincided with improved instrumentation featuring greater precision, increased mass accuracy, and faster scan speeds. We recently reported on a new quantitative method called MS1 Filtering (Schilling et al. (2012) Mol. Cell. Proteomics 11, 202-214) for processing data-independent MS1 ion intensity chromatograms from peptide analytes using the Skyline software platform. In contrast, data-independent acquisitions from MS2 scans, or SWATH, can quantify all fragment ion intensities when reference spectra are available. As each SWATH acquisition cycle typically contains an MS1 scan, these two independent label-free quantitative approaches can be acquired in a single experiment. Here, we have expanded the capability of Skyline to extract both MS1 and MS2 ion intensity chromatograms from a single SWATH data-independent acquisition in an Integrated Dual Scan Analysis approach. The performance of both MS1 and MS2 data was examined in simple and complex samples using standard concentration curves. Cases of interferences in MS1 and MS2 ion intensity data were assessed, as were the differentiation and quantitation of phosphopeptide isomers in MS2 scan data. In addition, we demonstrated an approach for optimization of SWATH m/z window sizes to reduce interferences using MS1 scans as a guide. Finally, a correlation analysis was performed on both MS1 and MS2 ion intensity data obtained from SWATH acquisitions on a complex mixture using a linear model that automatically removes signals containing interferences. This work demonstrates the practical advantages of properly acquiring and processing MS1 precursor data in addition to MS2 fragment ion

  1. The Syrian civil war: The experience of the Surgical Intensive Care Units.

    Science.gov (United States)

    Ozdogan, Hatice Kaya; Karateke, Faruk; Ozdogan, Mehmet; Cetinalp, Sibel; Ozyazici, Sefa; Gezercan, Yurdal; Okten, Ali Ihsan; Celik, Muge; Satar, Salim

    2016-01-01

    Since the civilian war in Syria began, thousands of seriously injured trauma patients from Syria were brought to Turkey for emergency operations and/or postoperative intensive care. The aim of this study was to present the demographics and clinical features of the wounded patients in Syrian civil war admitted to the surgical intensive care units in a tertiary care centre. The records of 80 trauma patients admitted to the Anaesthesia, General Surgery and Neurosurgery ICUs between June 1, 2012 and July 15, 2014 were included in the study. The data were reviewed regarding the demographics, time of presentation, place of reference, Acute Physiology and Chronic Health Evaluation II (APACHE II) score and Injury Severity Score (ISS), surgical procedures, complications, length of stay and mortality. A total of 80 wounded patients (70 males and 10 females) with a mean age of 28.7 years were admitted to surgical ICUs. The most frequent cause of injury was gunshot injury. The mean time interval between the occurrence of injury and time of admission was 2.87 days. Mean ISS score on admission was 21, and mean APACHE II score was 15.7. APACHE II scores of non-survivors were significantly increased compared with those of survivors (P=0.001). No significant differences was found in the age, ISS, time interval before admission, length of stay in ICU, rate of surgery before or after admission. The most important factor affecting mortality in this particular trauma-ICU patient population from Syrian civil war was the physiological condition of patients on admission. Rapid transport and effective initial and on-road resuscitation are critical in decreasing the mortality rate in civil wars and military conflicts.

  2. Results of the experience with the use of varenicline in daily practice using intensive monitoring

    NARCIS (Netherlands)

    Oosterhuis, I.; Harmark, L.; Van Puijenbroek, E.

    Background: Although a concise overview of Adverse Drug Reactions (ADRs) of varenicline is known, little is known about the time related information about ADRs of varenicline such as for example latencies. Objectives: To gain insight in the experience and safety of varenicline in daily practice as

  3. Power and Flow Experience in Time-Intensive Business Simulation Game

    Science.gov (United States)

    Kiili, Kristian; Lainema, Timo

    2010-01-01

    Power is an influential component of social interaction and there are reasons for thinking that it may have important effects both on decision-making and psychological and interpersonal processes. The aim of this paper was to study the relations between the feeling of power, decision-making and flow experience in a collaborative business…

  4. Patients' experience of thirst while being conscious and mechanically ventilated in the intensive care unit

    DEFF Research Database (Denmark)

    Kjeldsen, Caroline L; Hansen, Mette S; Jensen, Kamilla

    2017-01-01

    associate feelings of desperation, anxiety and powerlessness with the experience of thirst. These feelings have a negative impact on their psychological well-being. A strategy in the ICU that includes no sedation for critically ill patients in need of MV introduces new demands on the nurses who must care...

  5. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Science.gov (United States)

    M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

  6. Radioactive tracers in the sea

    International Nuclear Information System (INIS)

    Jenkins, W.J.; Livingston, H.D.

    1980-01-01

    Artificial radionuclides introduced to the oceans during the last four decades have proved invaluable tools for study of many processes in marine water columns and sediments. Both global and close-in fallout of radioactivity from atmospheric nuclear weapons testing have distributed these radionuclides widely, and in amounts sufficient to be useful as tracers. An additional source of considerable significance and tracer potential comes from coastal discharges of European nuclear fuel reprocessing wastes. The nature of these sources, types and amounts of radionuclides introduced and the time histories of their introduction generate a variety of tracer distributions which illuminate a broad spectrum of physical and chemical processes active over a wide range of timescales. Depending on their respective chemistries, artificial radionuclides have been demonstrated to exhibit both conservative and non-conservative properties in the oceans. Some examples are given of the uses made of soluble, conservative tracers for the study of oceanic transport processes and of non-conservative tracers for studies of processes which move them to, and mix them within, marine sediments. Sampling and measurement techniques which have been used in these studies are described

  7. Parents' experience of a follow-up meeting after a child's death in the Paediatric Intensive Care Unit

    DEFF Research Database (Denmark)

    Brink, Helle L; Thomsen, Anja K; Laerkner, Eva

    2017-01-01

    OBJECTIVE: 'To identify parents' experience of a follow up meeting and to explore whether the conversation was adequate to meet the needs of parents for a follow-up after their child's death in the Paediatric Intensive Care Unit (PICU). DESIGN AND SETTING: Qualitative method utilising semi...... to their questions both about treatment and care. It was important that the staff involved in the follow-up meeting were those who had been present through the hospitalisation and at the time of the child's death. Parents experienced the follow-up meeting as being a closure of the course in the PICU, regardless...

  8. Improving throughput and user experience for information intensive websites by applying HTTP compression technique.

    Science.gov (United States)

    Malla, Ratnakar

    2008-11-06

    HTTP compression is a technique specified as part of the W3C HTTP 1.0 standard. It allows HTTP servers to take advantage of GZIP compression technology that is built into latest browsers. A brief survey of medical informatics websites show that compression is not enabled. With compression enabled, downloaded files sizes are reduced by more than 50% and typical transaction time is also reduced from 20 to 8 minutes, thus providing a better user experience.

  9. Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

    Directory of Open Access Journals (Sweden)

    R. Wilson

    2017-08-01

    Full Text Available Ring-width (RW records from the Gulf of Alaska (GOA have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD proxy, the blue intensity (BI parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv or delta BI (DB can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June–September, which may have implications for studying ocean–atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th–21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per

  10. Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

    Science.gov (United States)

    Wilson, Rob; D'Arrigo, Rosanne; Andreu-Hayles, Laia; Oelkers, Rose; Wiles, Greg; Anchukaitis, Kevin; Davi, Nicole

    2017-08-01

    Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June-September, which may have implications for studying ocean-atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th-19th century temperatures ca. 0.5 °C cooler than the 20th-21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling

  11. The Brain on Art: Intense Aesthetic Experience Activates the Default Mode Network

    Directory of Open Access Journals (Sweden)

    Edward A Vessel

    2012-04-01

    Full Text Available Aesthetic responses to visual art comprise multiple types of experiences, from sensation and perception to emotion and self-reflection. Moreover, aesthetic experience is highly individual, with observers varying significantly in their responses to the same artwork. Combining fMRI and behavioral analysis of individual differences in aesthetic response, we identify two distinct patterns of neural activity exhibited by different subnetworks. Activity increased linearly with observers’ ratings (4-level scale in sensory (occipito-temporal regions. Activity in the striatum also varied linearly with ratings, with below-baseline activations for low-rated artworks. In contrast, a network of frontal regions showed a step-like increase only for the most moving artworks (4 ratings and non-differential activity for all others. This included several regions belonging to the default mode network previously associated with self-referential mentation. Our results suggest that aesthetic experience involves the integration of sensory and emotional reactions in a manner linked with their personal relevance.

  12. Adolescents' Daily Romantic Experiences and Negative Mood: A Dyadic, Intensive Longitudinal Study.

    Science.gov (United States)

    Rogers, Adam A; Ha, Thao; Updegraff, Kimberly A; Iida, Masumi

    2018-01-06

    Romantic relationships, although increasingly normative during adolescence, also present unique developmental challenges that can portend psychological difficulties. Underlying these difficulties may be the degree to which daily romantic transactions potentiate fluctuations in negative mood. The present study examined associations between adolescents' daily romantic relationship experiences and their same-day negative affective states (i.e., fluctuations in high-arousal, aversive mood). Using a dyadic ecological momentary assessment (EMA) design, this study followed an ethnically and socioeconomically diverse sample of 98 adolescent romantic couples twice weekly for 12 weeks (n = 196 individuals; M age  = 16.74 years, SD = 0.90; 45% Latina/o, 45% White; 55% receiving free or reduced meals). The results indicated that various daily romantic experiences (e.g., conflict, feelings about the relationship) predicted greater same-day negative affect. Beyond the effects of these romantic experiences, adolescent couples were also synchronized in their fluctuating negative affective states, evidencing the presence of emotional contagion. Overall, the findings indicate the salience of romantic relationships in the everyday lives of adolescents.

  13. Design Optimisation of a High Intensity Beam Facility and Feasibility Experiment of a Solid Fragmented Target

    CERN Document Server

    Charitonidis, Nikolaos; Rivkin, Leonid

    2014-06-13

    The present PhD thesis describes the design, execution and results of the HRMT-10 experiment performed at the HiRadMat facility of the CERN/SPS complex. The first part of the thesis covers the design optimization studies of the HiRadMat facility, focusing in particular on the radiation protection issues. A detailed Monte-Carlo model of the facility has been developed and validated through comparison with measurements. A very satisfactory agreement between the simulation and the experimental data is observed. In the second part of this thesis, a novel feasibility experiment of a fragmented solid target for a future Neutrino Factory or a Super Beam facility, able to support high beam powers ( 1 MW) is presented in detail. A solid granular target has been proposed as an interesting alternative to an open Hg jet target, presently considered as the baseline for such facilities, but posing considerable technical challenges. The HRMT-10 experiment seeks to address the lack of experimental data of the feasibility of...

  14. Radiochemical tracers in marine biology

    International Nuclear Information System (INIS)

    Petrocelli, S.R.; Anderson, J.W.; Neff, J.M.

    1977-01-01

    Tracers have been used in a great variety of experimentation. More recently, labeled materials have been applied in marine biological research. Some of the existing tracer techniques have been utilized directly, while others have been modified to suit the specific needs of marine biologists. This chapter describes some of the uses of tracers in marine biological research. It also mentions the problems encountered as well as offering possible solutions and discusses further applications of these techniques. Only pertinent references are cited and additional information may be obtained by consulting these references. Due to their relative ease of maintenance, freshwater species are also utilized in studies which involve radiotracer techniques. Since most of these techniques e directly applicable to marine species, some of these studies will also be included

  15. Radioisotope tracer applications in industry

    International Nuclear Information System (INIS)

    Rao, S.M.

    1987-01-01

    Radioisotope tracers have many advantages in industrial trouble-shooting and studies on process kinetics. The applications are mainly of two types: one leading to qualitative (Yes or No type) information and the other to quantitative characterisation of flow processes through mass balance considerations and flow models. ''Yes or No'' type methods are mainly used for leakage and blockage locations in pipelines and in other industrial systems and also for location of water seepage zones in oil wells. Flow measurements in pipelines and mercury inventory in electrolytic cells are good examples of tracer methods using the mass balance approach. Axial dispersion model and Tanks-in-Series model are the two basic flow models commonly used with tracer methods for the characterisation of kinetic processes. Examples include studies on flow processes in sugar crystallisers as well as in a precalcinator in a cement plant. (author). 18 figs

  16. First Experience Of Application Of High-Intensity Focused Ultrasonic Ablation (Hifu In Prostate Cancer Treatment

    Directory of Open Access Journals (Sweden)

    A.V. Stativko

    2009-12-01

    Full Text Available The scientific article points out that 40 sessions of HIFU prostate ablation have been performed for estimation of clinical efficiency. Average frequency of influences presents 628±164 impulses; average volume of tissues subjected to influence during one procedure is 33,8±16,3 smi (132 % of prostate volume; average operation time constitutes 150 minutes (from 90 to 200 minutes. During the operation no complications have been occurred. In the first days after the session of HIFU there was a peak of PSA increase and then during 1,5-3 months there was decrease to the lowest index. Minimal PSA level was reached in 10-12 weeks after treatment and it constituted from 0,04 till 1,1 ngml depending on the disease state. Reduction of prostate volume occurred in average from the 30th day of postoperative period and lasted for 6 months, reaching in average 50 % from initial volume. Postoperative period varied from 10 till 16 days and constituted in average 12±0,8 days. Thus application of high-intensity focused ultrasonic ablation allows treating successfully various stages of prostate cancer with minimal number of side-effects and makes possible the early estimation of treatment efficiency

  17. A prospective study of pain experience in a neonatal intensive care unit of China.

    Science.gov (United States)

    Chen, Mengying; Shi, Xiaoyan; Chen, Yinhua; Cao, Zhaolan; Cheng, Rui; Xu, Yuxiang; Liu, Li; Li, Xiaonan

    2012-10-01

    To assess pain burden in neonates during their hospitalization in China and thus provide evidence for the necessity of neonatal pain management. The Neonatal Facial Coding System was used to evaluate pain in neonates. We prospectively collected data of all painful procedures performed on 108 neonates (term, 62; preterm, 46) recruited from admission to discharge in a neonatal intensive care unit of a university-affiliated hospital in China. We found that during hospitalization each preterm and term neonate was exposed to a median of 100.0 (range, 11 to 544) and 56.5 (range, 12 to 249) painful procedures, respectively. Most of the painful procedures were performed within the first 3 days. Preterm neonates, especially those born at 28 and 29 weeks' gestational age, experienced more pain than those born at 30 weeks' gestation or later (Ppainful procedures, tracheal aspiration was the most frequently performed on preterm neonates, and intravenous cannulation was the most common for term neonates. Moreover, tracheal intubations and femoral venous puncture were found to be the most painful. Notably, none of the painful procedures was accompanied by analgesia. Neonates, particularly preterm neonates, were exposed to numerous invasive painful procedures without appropriate analgesia in hospitals in China. The potential long-term impacts of poorly treated pain in neonates call for a change in pediatric practice in China and in countries with similar practices.

  18. The end-of-life care experiences of relatives of brain dead intensive care patients.

    Science.gov (United States)

    Lloyd-Williams, Mari; Morton, Juliet; Peters, Sarah

    2009-04-01

    Brain death is a traumatic and sudden event following a severe injury to the brain. Most patients with brain death spend the last days of life in an intensive care unit (ICU), where some families will be approached to ask for organ donation. This qualitative study was carried out with relatives of patients who had died of brain death in an ICU; all relatives were interviewed six months after the death. Twenty ICUs were recruited for this study. The next of kin of 130 patients who died during the study period were approached, and 30 (22%) agreed to be interviewed; one later withdrew. This paper focuses on the perceived palliative care needs of the 29 families. Participants valued the physical care their relatives had received, but communication and breaking bad news was a cause for concern. The facilities on many ICUs, for example, cramped relatives' rooms and little privacy to be with the patients or to say the final goodbye, was a common theme to emerge. Bereavement follow-up did not routinely occur, and this was an identified factor noted by relatives. Families living through the period of brain death in a loved one may have particular needs in terms of end-of-life care and should be offered the support of a palliative care team through the last days of a patient's life and into the period of bereavement. Staff training on how to communicate bad news also should be implemented as a matter of urgency.

  19. Combination of Intensive Chemotherapy and Anticancer Vaccines in the Treatment of Human Malignancies: The Hematological Experience

    Directory of Open Access Journals (Sweden)

    Knut Liseth

    2010-01-01

    Full Text Available In vitro studies have demonstrated that cancer-specific T cell cytotoxicity can be induced both ex vivo and in vivo, but this therapeutic strategy should probably be used as an integrated part of a cancer treatment regimen. Initial chemotherapy should be administered to reduce the cancer cell burden and disease-induced immune defects. This could be followed by autologous stem cell transplantation that is a safe procedure including both high-dose disease-directed chemotherapy and the possibility for ex vivo enrichment of the immunocompetent graft cells. The most intensive conventional chemotherapy and stem cell transplantation are used especially in the treatment of aggressive hematologic malignancies; both strategies induce T cell defects that may last for several months but cancer-specific T cell reactivity is maintained after both procedures. Enhancement of anticancer T cell cytotoxicity is possible but posttransplant vaccination therapy should probably be combined with optimalisation of immunoregulatory networks. Such combinatory regimens should be suitable for patients with aggressive hematological malignancies and probably also for other cancer patients.

  20. Cosmological parameter forecasts for H I intensity mapping experiments using the angular power spectrum

    Science.gov (United States)

    Olivari, L. C.; Dickinson, C.; Battye, R. A.; Ma, Y.-Z.; Costa, A. A.; Remazeilles, M.; Harper, S.

    2018-01-01

    H I intensity mapping is a new observational technique to survey the large-scale structure of matter using the 21 cm emission line of atomic hydrogen (H I). In this work, we simulate BINGO (BAO from Integrated Neutral Gas Observations) and SKA (Square Kilometre Array) phase-1 dish array operating in autocorrelation mode. For the optimal case of BINGO with no foregrounds, the combination of the H I angular power spectra with Planck results allows w to be measured with a precision of 4 per cent, while the combination of the BAO acoustic scale with Planck gives a precision of 7 per cent. We consider a number of potentially complicating effects, including foregrounds and redshift-dependent bias, which increase the uncertainty on w but not dramatically; in all cases, the final uncertainty is found to be Δw ideal conditions, w can be measured with a precision of 4 per cent for the redshift range 0.35 < z < 3 (350-1050 MHz) and 2 per cent for 0 < z < 0.49 (950-1421 MHz). Extending the model to include the sum of neutrino masses yields a 95 per cent upper limit of ∑mν < 0.24 eV for BINGO and ∑mν < 0.08 eV for SKA phase 1, competitive with the current best constraints in the case of BINGO and significantly better than them in the case of SKA.

  1. Discharge against medical advice from Neonatal Intensive Care Unit: 10 years experience at a University Hospital.

    Science.gov (United States)

    Al-Turkistani, Hatim K

    2013-05-01

    Discharging patients against medical advice is a problem of every age-group. However, because of their physiological vulnerability, the risk for the neonatal population is greater when discharged against medical advice (DAMA). This article is a study of the prevalence of the problem, the possible causes and/or risk factors. A retrospective review of 10 years of medical records of neonates discharged against medical advice from a Neonatal Intensive Care Unit (NICU) at a university hospital. The overall prevalence of DAMA was 1.6%. Most of the 51 infants who were taken out of hospital against medical advice (AMA) were term (72.5%) with a mean gestational age of 37.78 ± 2.5 weeks, of normal birth weight, with a mean of 2736 ± 661 g, Saudis (96%), those delivered vaginally (69%), and those that were provisionally diagnosed with transient tachypnea of newborn (TTN) and/or query sepsis (49%). There was no difference between males and females (M/F = 1.2). There was an association between DAMA and the timing of DAMA (27.5% of DAMA at weekends and 67% of DAMA from May to October). DAMA of neonates is particularly critical. The causes and risk factors are many and difficult to predict. In addition to several other factors, its prevalence is influenced negatively by some socio-cultural beliefs.

  2. Development of activable tracers for application in secondary recovering in petroleum reservoirs

    International Nuclear Information System (INIS)

    Martins, Polyana Fabricia Fernandes; Moreira, Rubens Martins . Servico de Meio Ambiente e Tecnicas Nucleares.

    2007-01-01

    Nuclear methods are instrumental in describing detailed flow patterns and other features of oil reservoirs that are unattainable to other methods. Tracer studies in oil fields are performed in a net of injection and producing wells. Thus, the use of only one tracer species would not discriminate the contributions of distinct injection wells to the output of a given production well. Hence, a multi-tracer experiment is required, and the use of activable tracers, capable of being measured by neutron activation analysis (NAA) is here proposed. As additional tracer choices lanthanum (La) and europium (Eu) were chosen from the rare earth series due to their large neutron cross sections and general availability. In order to decrease losses to the oil phase and the retardation of the tracer relatively to the aqueous phase, these elements were complexed with organic chelating ligands: the polyaminocarboxylic acids EDTA, DTPA and DOTA. Infrared spectrometry was used to check complexation. In order to check the partition of the tracer between the aqueous and organic phases, tests were carried stirring the two phases together and measuring the tracer concentrations in the aqueous phase; the partition coefficient (Kao) was then calculated for all the combinations of the two lanthanides and the three ligands. Tests in which the tracer was continuously pumped through reservoir rock samples were also carried out using tritiated water as a reference tracer and the complexed lanthanides. (author)

  3. Journal: A Review of Some Tracer-Test Design Equations for ...

    Science.gov (United States)

    Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estimation equations are reviewed here, 32 of which were evaluated using previously published tracer-test design examination parameters. Comparison of the results produced a wide range of estimated tracer mass, but no means is available by which one equation may be reasonably selected over the others. Each equation produces a simple approximation for tracer mass. Most of the equations are based primarily on estimates or measurements of discharge, transport distance, and suspected transport times. Although the basic field parameters commonly employed are appropriate for estimating tracer mass, the 33 equations are problematic in that they were all probably based on the original developers' experience in a particular field area and not necessarily on measured hydraulic parameters or solute-transport theory. Suggested sampling frequencies are typically based primarily on probable transport distance, but with little regard to expected travel times. This too is problematic in that tends to result in false negatives or data aliasing. Simulations from the recently developed efficient hydrologic tracer-test design methodology (EHTD) were compared with those obtained from 32 of the 33 published tracer-

  4. Characterization of a managed aquifer recharge system using multiple tracers.

    Science.gov (United States)

    Moeck, Christian; Radny, Dirk; Popp, Andrea; Brennwald, Matthias; Stoll, Sebastian; Auckenthaler, Adrian; Berg, Michael; Schirmer, Mario

    2017-12-31

    Knowledge about the residence times of artificially infiltrated water into an aquifer and the resulting flow paths is essential to developing groundwater-management schemes. To obtain this knowledge, a variety of tracers can be used to study residence times and gain information about subsurface processes. Although a variety of tracers exists, their interpretation can differ considerably due to subsurface heterogeneity, underlying assumptions, and sampling and analysis limitations. The current study systematically assesses information gained from seven different tracers during a pumping experiment at a site where drinking water is extracted from an aquifer close to contaminated areas and where groundwater is artificially recharged by infiltrating surface water. We demonstrate that the groundwater residence times estimated using dye and heat tracers are comparable when the thermal retardation for the heat tracer is considered. Furthermore, major ions, acesulfame, and stable isotopes (δ 2 H and δ 18 O) show that mixing of infiltrated water and groundwater coming from the regional flow path occurred and a vertical stratification of the flow system exist. Based on the concentration patterns of dissolved gases (He, Ar, Kr, N 2 , and O 2 ) and chlorinated solvents (e.g., tetrachloroethene), three temporal phases are observed in the ratio between infiltrated water and regional groundwater during the pumping experiment. Variability in this ratio is significantly related to changes in the pumping and infiltration rates. During constant pumping rates, more infiltrated water was extracted, which led to a higher dilution of the regional groundwater. An infiltration interruption caused however, the ratio to change and more regional groundwater is extracted, which led to an increase in all concentrations. The obtained results are discussed for each tracer considered and its strengths and limitations are illustrated. Overall, it is demonstrated that aquifer heterogeneity and

  5. Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

    KAUST Repository

    Subramanian, S. K.

    2013-01-01

    The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.

  6. Kinetic limitations on tracer partitioning in ganglia dominated source zones.

    Science.gov (United States)

    Ervin, Rhiannon E; Boroumand, Ali; Abriola, Linda M; Ramsburg, C Andrew

    2011-11-01

    Quantification of the relationship between dense nonaqueous phase liquid (DNAPL) source strength, source longevity and spatial distribution is increasingly recognized as important for effective remedial design. Partitioning tracers are one tool that may permit interrogation of DNAPL architecture. Tracer data are commonly analyzed under the assumption of linear, equilibrium partitioning, although the appropriateness of these assumptions has not been fully explored. Here we focus on elucidating the nonlinear and nonequilibrium partitioning behavior of three selected alcohol tracers - 1-pentanol, 1-hexanol and 2-octanol in a series of batch and column experiments. Liquid-liquid equilibria for systems comprising water, TCE and the selected alcohol illustrate the nonlinear distribution of alcohol between the aqueous and organic phases. Complete quantification of these equilibria facilitates delineation of the limits of applicability of the linear partitioning assumption, and assessment of potential inaccuracies associated with measurement of partition coefficients at a single concentration. Column experiments were conducted under conditions of non-equilibrium to evaluate the kinetics of the reversible absorption of the selected tracers in a sandy medium containing a uniform entrapped saturation of TCE-DNAPL. Experimental tracer breakthrough data were used, in conjunction with mathematical models and batch measurements, to evaluate alternative hypotheses for observed deviations from linear equilibrium partitioning behavior. Analyses suggest that, although all tracers accumulate at the TCE-DNAPL/aqueous interface, surface accumulation does not influence transport at concentrations typically employed for tracer tests. Moreover, results reveal that the kinetics of the reversible absorption process are well described using existing mass transfer correlations originally developed to model aqueous boundary layer resistance for pure-component NAPL dissolution. Copyright © 2011

  7. Intensity ratios of H lines: departures from the ideal conditions in the range of laser-induced breakdown spectroscopy experiments.

    Science.gov (United States)

    Cruzado, A; Di Rocco, H O

    2007-10-01

    In the present paper we analyze the behavior of H line intensity ratios with electron density and electron temperature in intermediate-density plasmas. We analyze the influence on the line intensity ratios of (1) the departures from local thermodynamic equilibrium (LTE) of the level population ratios, (2) the plasma opacity, and (3) the lowering of the ionization potential. We look, particularly, at the lines H(alpha), H(beta), H(gamma), and H(delta) and the energy levels involved in the corresponding atomic transitions for their use as diagnostics in laser-induced breakdown spectroscopy (LIBS) experiments. One important conclusion is that, for typical values of the plasma dimension and the electron temperature taking place in LIBS, i.e., L = 1 mm and T(e) = 10 000 K, respectively, the intensity ratios H(beta)/H(alpha), H(gamma)/H(alpha), and H(delta)/H(alpha) depart from the ideal values by less than 10% in the interval 0.65 x 10(14) part/cm(3) gas of pure Hydrogen. For Higher densities, the departures from ideal conditions increase very quickly due to opacity effects.

  8. Development of experiments for high-intensity laser plasma interaction in a magnetic field of the pulsed power generator

    Science.gov (United States)

    Ivanov, V. V.; Swanson, K. J.; Maximov, A. V.; Betti, R.; Sawada, H.; Mancini, R. C.; Sentoku, Y.; Wiewior, P. P.; Astanovitskiy, A. L.; Nalajala, V.; Chalyy, O.; Dmitriev, O.; Wong, N.

    2017-10-01

    Experiments were developed for investigation of the laser plasma interaction in the megagauss magnetic field of the 1MA Zebra pulsed power generator coupled with a 50TW laser. These experiments are relevant to astrophysical plasmas, particle and x-ray generation, and isochoric heating in a strong magnetic field. Magnetic fields in loads were measured with Faraday rotation in a glass sample placed near the load. 1-3MG longitudinal and transversal magnetic fields were measured in different loads. Impact of the fast rising magnetic field on metal laser targets was demonstrated. Focusing and targeting laser systems were integrated into the chamber of the Zebra generator. Shots at intensity of >1018 W/cm2 demonstrated collimation of plasma and generation of jets on the front and rear sides of the foil target in the axial magnetic field. Work was supported by the DOE Grant DE-SC0016500 and DOE/NNSA Grant DE-NA 0002075.

  9. Normative cultural values and the experiences of Mexican-American mothers in the neonatal intensive care unit.

    Science.gov (United States)

    Cleveland, Lisa M; Horner, Sharon D

    2012-04-01

    To explore the experiences of Mexican-American mothers who have had infants in the neonatal intensive care unit (NICU). A convenience sample of 15 English-speaking, Mexican-American women was interviewed. The study used an exploratory qualitative approach. Data collection was conducted through audiotaped, transcribed, semistructured, individual interviews and field notes. The 5 normative cultural values for Latino families-(1) simpatia, (2) personalismo, (3) respeto, (4) familismo, and (5) fatalismo-were used as a sensitizing framework to guide data interpretation. The women's discussions of their NICU experiences clearly reflect the 5 normative Latino cultural values. Positive and negative exemplars of these values are provided as evidence. These findings can be used to inform nursing care provided for Mexican-American mothers and their infants by assisting nurses to customize care to meet the cultural needs of this population.

  10. Characterization of high intensity Ni-like X-ray lasers and their application experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.J.; Daido, H.; Suzuki, M. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Yamagami, S.; Nagai, K.; Norimatsu, T.; Mima, K.; Yamanaka, T. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Kato, Y.; Sasaki, A.; Hasegawa, N. [Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Wang, S.; Gu, Y.; Huang, G. [National Lab. on High Power Laser and Physics, Shanghai, SH (China); Carillon, A.; Ros, D.; Fourcade, P.; Jamelot, G. [Lab. de Spectroscopie Atomique et Ionique, Univ. Paris-Sud, Orsay (France); Joyeux, D.; Phalippou, D. [Lab. Charles Fabry, CNRS, Inst. d' Optique, Orsay (France); Murai, K. [Osaka National Research Inst., Ikeda, Osaka (Japan); Butzbach, R.; Uschmann, I.; Foerster, E. [IOQ, Friedrich-Schiller Univ., Jena (Germany); Namikawa, K.; Tai, R. [Tokyo Gakugei Univ., Koganei (Japan); Koike, F. [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine; Takenaka, H. [NTT Advanced Technology, Musashino (Japan); Zhang, G. [Inst. of Applied Physics and Computational Mathematics, Beijing, BJ (China); Choi, I.W. [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    At the Institute of Laser Engineering, Osaka University, we have obtained Ni-like X-ray lasers of various atomic number elements, including many shorter wavelength Ni-like lasing lines around 5 nm. The saturated amplification of Ni-like Ag lasing line at the wavelength of 13.9 nm have been observed. Using these X-ray lasers, we are preparing the application experiments such as probing a laser-produced plasma with an X-ray laser interferometer. (orig.)

  11. Operating Room Within the Neonatal Intensive Care Unit--Experience of a Medical Center in Taiwan.

    Science.gov (United States)

    Wang, Ya-Lei; Jeng, Suh-Fang; Tsao, Po-Nien; Chou, Hung-Chieh; Chen, Chien-Yi; Hsieh, Wu-Shiun

    2015-08-01

    Most neonates who reside in the neonatal intensive care unit (NICU) and require surgery are transferred to the operating room (OR) or undergo bedside surgery. However, critically ill neonates who are transferred often encounter the risk of complications. An OR in our NICU was therefore launched in 2009. This study was to appraise the surgeries performed in the NICU OR and compare results with the traditional main OR outside the NICU. This was a retrospective study in the NICU of a tertiary center. Retrospective chart review was conducted for all neonates who underwent surgical procedures in the NICU OR and the main OR. The information regarding baseline characteristics, surgical procedures and duration, ventilator use, hypothermia, hyperglycemia, instrument dislocations, surgically related infection or complications, and outcomes was obtained. There were a total of 65 patients in this study, 37 in the NCIU OR group and 28 in the main OR group. The presurgical mean airway pressure and the fraction of inspired oxygen (FiO2) were comparable between the two groups, but the postsurgical FiO2 was significantly lower in the NICU OR group (31.0%) than in the main OR group (40.9%; p = 0.027). Furthermore, the NICU OR group required a significantly shorter preoperation waiting time (34.4 minutes vs. 63.6 minutes, p = 0.001) and had a lower incidence of hypothermia than the main OR group (8.1% vs. 39.3%, p = 0.008). However, surgically related complications were similar between groups. The OR within the NICU may reduce the risk of complications during transportation and provide continuity of care to critically ill neonates. It also decreases the disturbance to other NICU patients during operation. Copyright © 2014. Published by Elsevier B.V.

  12. Survey of Canadian critical care nurses' experiences of conflict in intensive care units.

    Science.gov (United States)

    Edwards, Marie; Throndson, Karen; Girardin, Julie

    2012-01-01

    The purpose of this study was to enhance our understanding of Canadian critical care nurses' experiences of and responses to situations of conflict in the ICU. Through a 35-item web-based survey, members of the Canadian Association of Critical Care Nurses were asked questions regarding the types, causes and frequency of conflict experienced, the nursing interventions found most helpful in situations of conflict, and the resources found most helpful in responding to situations of conflict. A total of 241 nurses responded to the survey. The mean age of the nurses was 43 years, and the majority were female (89.2%), direct care providers (66.4%), with greater than 11 years of experience in critical care (58.3%), and working in medical/surgical ICUs (66.4%) in tertiary care hospitals (67.2%). Approximately 51% of the nurses reported being involved in at least one situation of conflict related to the management of a patient in the last week worked. The most common types of conflict encountered were disagreements between the team and family (46.5%) or within the team (35.3%). The nurses acknowledged the importance of clear, consistent and honest communication with patients and families when conflict arises and rank-ordered the resources found most helpful to patients, families, and nurses in conflict situations. Implications for practice and education are discussed and recommendations for future research are outlined.

  13. Computer-intensive simulation of solid-state NMR experiments using SIMPSON.

    Science.gov (United States)

    Tošner, Zdeněk; Andersen, Rasmus; Stevensson, Baltzar; Edén, Mattias; Nielsen, Niels Chr; Vosegaard, Thomas

    2014-09-01

    Conducting large-scale solid-state NMR simulations requires fast computer software potentially in combination with efficient computational resources to complete within a reasonable time frame. Such simulations may involve large spin systems, multiple-parameter fitting of experimental spectra, or multiple-pulse experiment design using parameter scan, non-linear optimization, or optimal control procedures. To efficiently accommodate such simulations, we here present an improved version of the widely distributed open-source SIMPSON NMR simulation software package adapted to contemporary high performance hardware setups. The software is optimized for fast performance on standard stand-alone computers, multi-core processors, and large clusters of identical nodes. We describe the novel features for fast computation including internal matrix manipulations, propagator setups and acquisition strategies. For efficient calculation of powder averages, we implemented interpolation method of Alderman, Solum, and Grant, as well as recently introduced fast Wigner transform interpolation technique. The potential of the optimal control toolbox is greatly enhanced by higher precision gradients in combination with the efficient optimization algorithm known as limited memory Broyden-Fletcher-Goldfarb-Shanno. In addition, advanced parallelization can be used in all types of calculations, providing significant time reductions. SIMPSON is thus reflecting current knowledge in the field of numerical simulations of solid-state NMR experiments. The efficiency and novel features are demonstrated on the representative simulations. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Human calcium metabolism including bone resorption measured with {sup 41}Ca tracer

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, S.P.H.T. [Lawrence Livermore National Lab., CA (United States); King, J.C. [California Univ., Berkeley, CA (United States). Dept. of Nutritional Science; Vieira, N.E. [National Inst. of Child Health and Human Development, Bethesda, MD (United States); Woodhouse, L.R. [California Univ., Berkeley, CA (United States). Dept. of Nutritional Science; Yergey, A.L. [National Inst. of Child Health and Human Development, Bethesda, MD (United States)

    1996-08-01

    Accelerator mass spectrometry is so sensitive to small quantities of {sup 41}Ca that it might be used as a tracer in the study of human calcium kinetics to generate unique kinds of data. In contrast with the use of other Ca isotopic tracers, {sup 41}Ca tracer can be so administered that the tracer movements between the various body pools achieve a quasi steady state. Resorbing bone may thus be directly measured. We have tested such a protocol against a conventional stable isotope experiment with good agreement.

  15. The characterization of petroleum contamination in heterogenous media using partitioning tracer method

    International Nuclear Information System (INIS)

    Kim, E.; Rhee, S.; Park, J.

    2009-01-01

    A partitioning tracer method for characterizing petroleum contamination in heterogenous media was discussed. The average saturation level of nonaqueous phase liquids (NAPLs) was calculated by comparing the transport of the partitioning tracers to a conservative tracer. The NAPL saturation level represented a continuous value throughout the contaminated site. Experiments were conducted in a 2-D sandbox divided into 4 parts using different-sized sands. Soils were contaminated with a mixture of kerosene and diesel. Partitioning tracer tests were conducted both before and after contamination. A partitioning batch test was conducted to determine the partition coefficient (K) of the tracer between the NAPL and water. Breakthrough curves were obtained, and a retardation factor (R) was calculated. Results of the study showed that the calculated NAPL saturation was in good agreement with determined values. It was concluded that the partitioning tracer test is an accurate method of locating and quantifying NAPLs

  16. A new drift chamber TDC readout for the high intensity program of the NA48 experiment

    CERN Document Server

    Ramusino, A C; Cartiglia, N; Chiozzi, S; Clemencic, M; Damiani, C; Gianoli, A; Milano, L; Malaguti, R; Petrucci, F; Scarpa, M

    2004-01-01

    A new read-out for the drift chambers (DCH) (8192 channels) of the NA48 experiment at CERN has been developed and realized by the Ferrara and Torino INFN sites and has taken data during the 2002 run. The core of the system is a set of 32 VME-9U Time-to-Digital- Converter boards (NA48-TDC). The NA48-TDCs record the time of arrival of signals from the DCH and store them in 40 MHz pipelined ring memories pending the trigger supervisor's decision. Dual memories and data extraction resources allow independent and simultaneous processing of level-1 and level-2 trigger requests. Time measurements are performed by the TDC-F1 commercial ASICs, having an intrinsic time resolution of 120 ps and multi-hit capabilities. The NA48-TDC board features a maximum sustained rate of 500 kHz per channel.

  17. Comparison of two methods of performing the Thellier experiment. [paleomagnetic intensity determination

    Science.gov (United States)

    Levi, S.

    1975-01-01

    Two methods for performing the Thellier experiment on paleointensity determinations are compared. The first method is essentially that of Coe (1967) and the second is a slight modification of it. Prepared samples containing different species of magnetic particles are used, and both methods are always performed on the same sample. The study is designed to accent procedural differences between the two methods. It is shown that only the Coe method yields linear PNRM-PTRM (Partial ThermoRemanent Magnetization) plots for single domain and pseudo-single domain particles, because it maintains the symmetry between high-temperature VRM (Viscous Remanent Magnetization) and spontaneous decay, whereas for the modified Coe method the spontaneous decay is enhanced. For multidomain remanence, even the Coe method yields a nonlinear concave-up PNRM-PTRM plot. Paleointensity determinations employing only the ratio NRM/TRM provide no means of evaluating the reliability of the results.

  18. Experiments and Observations on Intense Alfven Waves in the Laboratory and in Space

    International Nuclear Information System (INIS)

    Gekelman, W.; VanZeeland, M.; Vincena, S.; Pribyl, P.

    2003-01-01

    There are many situations, which occur in space (coronal mass ejections, supernovas), or are man-made (upper atmospheric detonations) in which a dense plasma expands into a background magnetized plasma that can support Alfven waves. The LArge Plasma Device (LAPD) is a machine, at UCLA, in which Alfven wave propagation in homogeneous and inhomogeneous plasmas has been studied. These will be briefly reviewed. A new class of experiments which involve the expansion of a dense (initially, δn/no>>1) laser-produced plasma into an ambient highly magnetized background plasma capable of supporting Alfven waves will be presented. Measurements are used to estimate the coupling efficiency of the laser energy and kinetic energy of the dense plasma into wave energy. The wave generation mechanism is due to field aligned return currents, coupled to the initial electron current, which replace fast electrons escaping the initial blast

  19. Proposed development of novel diagnostics for intense, ultrafast laser-plasma experiments at JAEA-KPSI

    International Nuclear Information System (INIS)

    Bolton, Paul R.; Tatchyn, Roman; Fukuda, Yuji; Kando, Masaki; Daito, Izuru; Ma, Jinglong; Chen, Liming; Pirozhkov, Alexander; Tajima, Toshiki

    2007-01-01

    Development of new diagnostics is critical for future laser-plasma accelerators, laser-driven light sources and for x-ray FELs. Recent laser wakefield electron acceleration developments and novel beam-based light source schemes (such as free electron lasers) obviate the need for next generation ultrafast diagnostics, capable of temporal resolution of a few femtoseconds (and in some cases attoseconds) for laser pulses (high order harmonics), x-ray pulses and electron bunches. Single shot detection capability in noninvasive and parasitic modes is also important. Alterations of laser pulse spectra and the associated dynamics can be informative diagnostics. The portion of a high intensity laser pulse that is transmitted through a self-induced underdense plasma (such as in laser wakefield acceleration LWFA schemes) carries the effects of plasma processes it has experienced. A distinction between the self-modulated laser wakefield (SMLWF) acceleration regime and the forced laser wakefield (FLWF) acceleration regime is in the spectral signature of the transmitted ir laser pulse. The former regime generates sidebands from stimulated Raman forward scattering (SRS-F) and the latter exhibits general spectral broadening that evidences ir laser pulse compression. Transmitted spectral effects can diagnose these acceleration regimes. Existing noninvasive electro-optic (EO) schemes for detection of ultrashort electron bunches are limited by material properties to temporal resolution at the 50-100 femtosecond level. While timing jitter at conventional accelerators is of this order (or greater), single bunch longitudinal profile measurements can require improvement of at least an order of magnitude. A new FO technique is described here which monitors enhancement and associated dynamics of spectral components in a probe pulse. Three correlation schemes for detecting ultrashort x-ray pulses are described. Two-photon absorption in tailored ion targets is proposed for scanning auto

  20. Functional progression of patients with neurological diseases in a tertiary paediatric intensive care unit: Our experience.

    Science.gov (United States)

    Madurga Revilla, P; López Pisón, J; Samper Villagrasa, P; García Íñiguez, J P; Garcés Gómez, R; Domínguez Cajal, M; Gil Hernández, I

    2017-11-23

    Neurological diseases explain a considerable proportion of admissions to paediatric intensive care units (PICU), and are a significant cause of morbidity and mortality. This study aims to analyse the functional progression of children with critical neurological conditions. Retrospective descriptive study of children admitted to PICU with neurological diseases over a period of 3 years (2012-2014), assessing vital and functional prognosis at PICU discharge and at one year according to the Pediatric Cerebral and Overall Performance Category scales (PCPC-POPC) and the Functional Status Scale (FSS). The results are compared with our previous data (1990-1999), and those of the international multicentre PANGEA study. A total of 266 children were studied. The mortality rate was 3%; the PRISM-III and PIM2 models did not show predictive ability. Clinically significant worsening was observed in functional health at discharge in 30% of the sample, according to POPC, 15% according to PCPC, and 5% according to FSS. After one year, functional performance improved according to PCPC-POPC, but not according to FSS. Children with no underlying neurological disease had a higher degree of functional impairment; this was prolonged over time. We observed a decrease in overall and neurocritical mortality compared with our previous data (5.60 vs. 2.1%, P=.0003, and 8.44 vs. 2.63%, P=.0014, respectively). Compared with the PANGEA study, both mortality and cerebral functional impairment in neurocritical children were lower in our study (1.05 vs. 13.32%, P<.0001, and 10.47% vs. 23.79%, P<.0001, respectively). Nearly one-third of critically ill children have neurological diseases. A significant percentage, mainly children without underlying neurological diseases, had a clinically significant functional impact at PICU discharge and after a year. Neuromonitoring and neuroprotection measures and the evaluation of functional progression are necessary to improve critical child care. Copyright

  1. Tracer diffusion in a sea of polymers with binding zones: mobile vs. frozen traps.

    Science.gov (United States)

    Samanta, Nairhita; Chakrabarti, Rajarshi

    2016-10-19

    We use molecular dynamics simulations to investigate the tracer diffusion in a sea of polymers with specific binding zones for the tracer. These binding zones act as traps. Our simulations show that the tracer can undergo normal yet non-Gaussian diffusion under certain circumstances, e.g., when the polymers with traps are frozen in space and the volume fraction and the binding strength of the traps are moderate. In this case, as the tracer moves, it experiences a heterogeneous environment and exhibits confined continuous time random walk (CTRW) like motion resulting in a non-Gaussian behavior. Also the long time dynamics becomes subdiffusive as the number or the binding strength of the traps increases. However, if the polymers are mobile then the tracer dynamics is Gaussian but could be normal or subdiffusive depending on the number and the binding strength of the traps. In addition, with increasing binding strength and number of polymer traps, the probability of the tracer being trapped increases. On the other hand, removing the binding zones does not result in trapping, even at comparatively high crowding. Our simulations also show that the trapping probability increases with the increasing size of the tracer and for a bigger tracer with the frozen polymer background the dynamics is only weakly non-Gaussian but highly subdiffusive. Our observations are in the same spirit as found in many recent experiments on tracer diffusion in polymeric materials and question the validity of using Gaussian theory to describe diffusion in a crowded environment in general.

  2. Application of multitracer technology to petroleum reservoir studies. [Perfluorocarbon tracer technology

    Energy Technology Data Exchange (ETDEWEB)

    Senum, G.I.

    1992-09-01

    The objectives of this research program are to: Improve the assessment of the character of petroleum reservoirs using tracer technology for the monitoring and improvement of EOR techniques, specifically, (a) to apply the presently available multitracer perfluorocarbon tracer (PFI) technology to the study of petroleum reservoirs in characterizing reservoir bulk subsurface flow transport and dispersion rates; and (b) to demonstrate that PFTs with differing physical properties will interact with differing rates of adsorption and dispersion within such reservoirs, from which may be inferred difference in the character and/or extent of petroleum in those reservoirs. Develop additional tracers, and tracer injection, sampling and analyses methodologies for use in petroleum reservoir characterization experiments. Develop a data base of petroleum transport and dispersion properties from tracer experiments for use by modellers for developing, validating and extending petroleum reservoirs models used for characterizing petroleum reservoirs. Technical progress is discussed according to the three ongoing field experiments at the Naval Petroleum Reserve in California (NPRC).

  3. Bioethics. LC Science Tracer Bullet.

    Science.gov (United States)

    Martin, Cathy, Comp.; Cadoree, Michelle

    This guide lists published materials on many aspects of bioethics, the literature of which is varied and scattered. Related guides in the LC Science Tracer Bullet series are TB 80-9, Terminal Care, TB 80-11, Drug Research on Human Subjects, TB 83-4, Science Policy, and TB 84-7, Biotechnology. Not intended to be a comprehensive bibliography, this…

  4. Tracer-monitored flow titrations.

    Science.gov (United States)

    Sasaki, Milton K; Rocha, Diogo L; Rocha, Fábio R P; Zagatto, Elias A G

    2016-01-01

    The feasibility of implementing tracer-monitored titrations in a flow system is demonstrated. A dye tracer is used to estimate the instant sample and titrant volumetric fractions without the need for volume, mass or peak width measurements. The approach was applied to spectrophotometric flow titrations involving variations of sample and titrant flow-rates (i.e. triangle programmed technique) or concentration gradients established along the sample zone (i.e. flow injection system). Both strategies required simultaneous monitoring of two absorbing species, namely the titration indicator and the dye tracer. Mixing conditions were improved by placing a chamber with mechanical stirring in the analytical path aiming at to minimize diffusional effects. Unlike most of flow-based titrations, the innovation is considered as a true titration, as it does not require a calibration curve thus complying with IUPAC definition. As an application, acidity evaluation in vinegars involving titration with sodium hydroxide was selected. Phenolphthalein and brilliant blue FCF were used as indicator and dye tracer, respectively. Effects of sample volume, titrand/titrant concentrations and flow rates were investigated aiming at improved accuracy and precision. Results were reliable and in agreement with those obtained by a reference titration procedure. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

    Science.gov (United States)

    Wu, Q.; Sun, L. T.; Cui, B. Q.; Lian, G.; Yang, Y.; Ma, H. Y.; Tang, X. D.; Zhang, X. Z.; Zhang, Z. M.; Liu, W. P.

    2016-09-01

    The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H+, 10 emA He+ and 2.0 emA He2+ beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

  6. Numerical simulation and experiment of high-intensity current pulsed impact on the structure body

    International Nuclear Information System (INIS)

    Li Mintang; Yan Ping; Yuan Weiqun; Sun Yaohong; Sun Lianhua; Zhou Yuan; Liu Chuanpu

    2010-01-01

    To better understand the characteristics of the impulse force formed by pulse current of electromagnetic rail propulsion system, and to explore effective ways to improve the support structure of rails, a set of impulse force test system was designed, and the work-related test situation was numerically simulated. Several impulse force waveforms formed by different pulse current waveforms were achieved by using an armature as a source of impulse force in this test system, and two curves of waveform were comparatively analyzed. The armature existing in the environment of coupling fields including electric field and magnetic field and force field was carried out numerical calculation by using the software of ANSYS, and the coupling force field was emphatically analyzed to calculate the electromagnetic driving force and the electromagnetic clamping force acting on the armature, and the structure stress and deformation was also analyzed. The results showed that the curves of electromagnetic driving force computed by numerical simulation and the curves of impulse force obtained by experiment were basically the same, and the value of peak points' error was increasing along with the increase of pulse current, but the curves still showed some common characteristics. This verified that the test method we used in this paper was proper to capture the impulse force, and the method of calculation was also feasible and effective. (authors)

  7. Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q., E-mail: wuq@impcas.ac.cn [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, L.T., E-mail: sunlt@impcas.ac.cn [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Cui, B.Q.; Lian, G. [China Institute of Atomic Energy, Beijing 102413 (China); Yang, Y.; Ma, H.Y.; Tang, X.D.; Zhang, X.Z.; Zhang, Z.M. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, W.P. [China Institute of Atomic Energy, Beijing 102413 (China)

    2016-09-11

    The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H{sup +}, 10 emA He{sup +} and 2.0 emA He{sup 2+} beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

  8. Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

    International Nuclear Information System (INIS)

    Wu, Q.; Sun, L.T.; Cui, B.Q.; Lian, G.; Yang, Y.; Ma, H.Y.; Tang, X.D.; Zhang, X.Z.; Zhang, Z.M.; Liu, W.P.

    2016-01-01

    The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H + , 10 emA He + and 2.0 emA He 2+ beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

  9. The High-Intensity K+ Beam for the NA62 Experiment

    CERN Document Server

    Doble, N

    2011-01-01

    The NA62 experiment, approved in 2009, aims to measure the branching ratio of the very rare decay K+ → + with a precision of ±10%. This branching ratio is calculable with good precision in the Standard Model to be (8.5±0.7) 10-11. Predictions of this branching ratio are also available for various extensions of the Standard Model, including supersymmetry and a 4th generation of quarks and leptons, and show that this decay mode is very sensitive to physics beyond the Standard Model. To achieve the K+ decay rate required to collect some 100 events of this very rare process in two years, a new 75 GeV/c secondary hadron beam line has been designed, which provides a ≈ 40x higher kaon flux per incident proton than the previous K12 beam for NA48/2 and at the same time sufficiently small halo rates to allow the very high veto efficency necessary to perform this delicate measurement. The K+ content in the beam is ≈ 6%. In this note we describe in detail the design of this new beam line, which wil...

  10. Polyethyleneimine as tracer for electron microscopy

    NARCIS (Netherlands)

    Schurer, Jacob Willem

    1980-01-01

    In this thesis the development of a tracer particle for use in electron microscopy is described. Attempts were made to use this tracer particle in immuno-electron microscopy and to trace negatively charged tissue components. ... Zie: Summary

  11. Tracers of cancer cells in nuclear oncology

    International Nuclear Information System (INIS)

    Tamgac, F.; Baillet, G.; Moretti, J.L.; Safi, N.; Weinmann, P.; Beco, V. de

    1997-01-01

    Evaluating the extent of disease is important in planning cancer treatment. Different types of tracers are used in vivo to diagnose tumors and these tracers can give supplementary information on the differentiation degree of tumors and response to therapy. (authors)

  12. PIV tracer behavior on propagating shock fronts

    International Nuclear Information System (INIS)

    Glazyrin, Fyodor N; Mursenkova, Irina V; Znamenskaya, Irina A

    2016-01-01

    The present work was aimed at the quantitative particle image velocimetry (PIV) measurement of a velocity field near the front of a propagating shock wave and the study of the dynamics of liquid tracers crossing the shock front. For this goal, a shock tube with a rectangular cross-section (48  ×  24 mm) was used. The flat shock wave with Mach numbers M  =  1.4–2.0 propagating inside the tube channel was studied as well as an expanding shock wave propagating outside the channel with M  =  1.2–1.8 at its main axis. The PIV imaging of the shock fronts was carried out with an aerosol of dioctyl sebacate (DEHS) as tracer particles. The pressures of the gas in front of the shock waves studied ranged from 0.013 Mpa to 0.1 MPa in the series of experiments. The processed PIV data, compared to the 1D normal shock theory, yielded consistent values of wake velocity immediately behind the plain shock wave. Special attention was paid to the blurring of the velocity jump on the shock front due to the inertial particle lag and peculiarities of the PIV technique. A numerical algorithm was developed for analysis and correction of the PIV data on the shock fronts, based on equations of particle-flow interaction. By application of this algorithm, the effective particle diameter of the DEHS aerosol tracers was estimated as 1.03  ±  0.12 μm. A number of different formulations for particle drag were tested with this algorithm, with varying success. The results show consistency with previously reported experimental data obtained for cases of stationary shock waves. (paper)

  13. TRACER DISPERSION STUDIES FOR HYDRAULIC CHARACTERIZATION OF PIPES

    Science.gov (United States)

    A series of experiments were conducted at the U. S. Environmental Protection Agency (EPA) Test & Evaluation (T&E) Facility in Cincinnati, Ohio, to quantify longitudinal dispersion of a sodium fluoride tracer in polyvinyl chloride (PVC) pipe and ductile iron pipe under laminar, tr...

  14. Interwell tracer analyses of a hydraulically fractured granitic geothermal reservoir

    International Nuclear Information System (INIS)

    Tester, J.W.; Potter, R.M.; Bivins, R.L.

    1979-01-01

    Field experiments using fluorescent dye and radioactive tracers (Br 82 and I 131 ) have been employed to characterize a hot, low-matrix permeability, hydraulically-fractured granitic reservoir at depths of 2440 to 2960 m (8000 to 9700 ft). Tracer profiles and residence time distributions have been used to delineate changes in the fracture system, particularly in diagnosing pathological flow patterns and in identifying new injection and production zones. The effectiveness of one- and two-dimensional theoretical dispersion models utilizing single and multiple porous, fractured zones with velocity and formation dependent effects are discussed with respect to actual field data

  15. An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

    Energy Technology Data Exchange (ETDEWEB)

    Bertarelli, A., E-mail: alessandro.bertarelli@cern.ch [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Berthome, E. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Boccone, V. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Carra, F. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Cerutti, F. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Charitonidis, N. [CERN, Engineering Department, Machines and Experimental Facilities Group (EN-MEF), CH-1211 Geneva 23 (Switzerland); École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Charrondiere, C. [CERN, Engineering Department, Industrial Controls and Engineering Group (EN-ICE), CH-1211 Geneva 23 (Switzerland); Dallocchio, A.; Fernandez Carmona, P.; Francon, P.; Gentini, L.; Guinchard, M.; Mariani, N. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Masi, A. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Marques dos Santos, S.D.; Moyret, P. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Peroni, L. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Redaelli, S. [CERN, Beams Department, Accelerators and Beams Physics Group (BE-ABP), CH-1211 Geneva 23 (Switzerland); Scapin, M. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2013-08-01

    Predicting the consequences of highly energetic particle beams impacting protection devices as collimators or high power target stations is a fundamental issue in the design of state-of-the-art facilities for high-energy particle physics. These complex dynamic phenomena can be successfully simulated resorting to highly non-linear numerical tools (Hydrocodes). In order to produce accurate results, however, these codes require reliable material constitutive models that, at the extreme conditions induced by a destructive beam impact, are scarce and often inaccurate. In order to derive or validate such models a comprehensive, first-of-its-kind experiment has been recently carried out at CERN HiRadMat facility: performed tests entailed the controlled impact of intense and energetic proton pulses on a number of specimens made of six different materials. Experimental data were acquired relying on embedded instrumentation (strain gauges, temperature probes and vacuum sensors) and on remote-acquisition devices (laser Doppler vibrometer and high-speed camera). The method presented in this paper, combining experimental measurements with numerical simulations, may find applications to assess materials under very high strain rates and temperatures in domains well beyond particle physics (severe accidents in fusion and fission nuclear facilities, space debris impacts, fast and intense loadings on materials and structures etc.)

  16. Development of radioisotope tracer technology and nucleonic control system

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee and others

    1999-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and basic technology of nuclear control systems that are widely used for automation of industrial plants, and to build a strong tracer group to support the local industries. In relation to the tracer technology, the data acquisition system, the column scanning equipment and the detection pig for a leakage test have been developed. In order to use in analyzing data of tracer experiments, a computer program for the analysis of residence time distribution has been created as well. These results were utilized in developing the tracer technologies, such as the column scanning, the flow measurement using the dilution method, the simultaneous monitoring rotational movement of piston rings and the optimization of a waste water treatment facility, and the technologies were successfully demonstrated in the local industrial. The stripper of RFCC reactor has been examined to find an unwanted structure in it by imminent request from the industry. Related to the development of nucleonic control system, the state of art report on the technology has been written and an equipment for the analysis of asphalt content has been developed. (author)

  17. Integrated nonlinear regression analysis of tracer and well test data

    Energy Technology Data Exchange (ETDEWEB)

    Akin, Serhat [Petroleum and Natural Gas Engineering Department, Middle East Technical University, Inonu Bulvari 06531 Ankara (Turkey)

    2003-08-01

    One frequent observation from conventional pressure transient test analysis is that field data match mathematical models derived for homogeneous systems. This observation suggests that pressure data as presently interpreted may not contain details concerning certain reservoir heterogeneities. On the other hand, tracer tests may be more sensitive to heterogeneous elements present in the reservoir because of the convective nature of the flow test. In this study, a possible improvement of conventional pressure transient and tracer test analysis by integrating them using the nonlinear least square (LS) regression method is investigated. To achieve this goal, a correlation between permeability and dispersivity is used to couple the response of both tests. A multi-fracture tracer test model was coupled with double porosity pressure models using a commercial spreadsheet. The proposed method is tested using experimental well test and tracer test data obtained from a fractured geothermal reservoir model where fracture apertures and distributions were known. It has been observed that changing injection-production well depths resulted in different analyses primarily due to changing flow paths. The combination of multi-fracture tracer test model with dual-porosity pressure transient model described the physics of the experiments better than the others did. It has been also observed that the obtained solutions are highly constrained.

  18. High-Intensity Radiated Field Fault-Injection Experiment for a Fault-Tolerant Distributed Communication System

    Science.gov (United States)

    Yates, Amy M.; Torres-Pomales, Wilfredo; Malekpour, Mahyar R.; Gonzalez, Oscar R.; Gray, W. Steven

    2010-01-01

    Safety-critical distributed flight control systems require robustness in the presence of faults. In general, these systems consist of a number of input/output (I/O) and computation nodes interacting through a fault-tolerant data communication system. The communication system transfers sensor data and control commands and can handle most faults under typical operating conditions. However, the performance of the closed-loop system can be adversely affected as a result of operating in harsh environments. In particular, High-Intensity Radiated Field (HIRF) environments have the potential to cause random fault manifestations in individual avionic components and to generate simultaneous system-wide communication faults that overwhelm existing fault management mechanisms. This paper presents the design of an experiment conducted at the NASA Langley Research Center's HIRF Laboratory to statistically characterize the faults that a HIRF environment can trigger on a single node of a distributed flight control system.

  19. Nurses' experiences of caring for critically ill, non-sedated, mechanically ventilated patients in the Intensive Care Unit

    DEFF Research Database (Denmark)

    Laerkner, Eva; Egerod, Ingrid; Hansen, Helle Ploug

    2015-01-01

    closeness. CONCLUSION: Despite the complexity of care, nurses preferred to care for more awake rather than sedated patients and appreciated caring for just one patient at a time. The importance of close collaboration between nurses and doctors to ensure patient comfort during mechanical ventilation......OBJECTIVE: The objective was to explore nurses' experiences of caring for non-sedated, critically ill patients requiring mechanical ventilation. DESIGN AND SETTING: The study had a qualitative explorative design and was based on 13 months of fieldwork in two intensive care units in Denmark where...... a protocol of no sedation is implemented. Data were generated during participant observation in practice and by interviews with 16 nurses. Data were analysed using thematic interpretive description. FINDINGS: An overall theme emerged: "Demanding, yet rewarding". The demanding aspects of caring for more awake...

  20. An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

    CERN Document Server

    Bertarelli, A; Boccone, V; Carra, F; Cerutti, F; Charitonidis, N; Charrondiere, C; Dallocchio, A; Fernandez Carmona, P; Francon, P; Gentini, L; Guinchard, M; Mariani, N; Masi, A; Marques dos Santos, S D; Moyret, P; Peroni, L; Redaelli, S; Scapin, M

    2013-01-01

    Predicting the consequences of highly energetic particle beams impacting protection devices as collimators or high power target stations is a fundamental issue in the design of state-of-the-art facilities for high-energy particle physics. These complex dynamic phenomena can be successfully simulated resorting to highly non-linear numerical tools (Hydrocodes). In order to produce accurate results, however, these codes require reliable material constitutive models that, at the extreme conditions induced by a destructive beam impact, are scarce and often inaccurate. In order to derive or validate such models a comprehensive, first-of-its-kind experiment has been recently carried out at CERN HiRadMat facility: performed tests entailed the controlled impact of intense and energetic proton pulses on a number of specimens made of six different materials. Experimental data were acquired relying on embedded instrumentation (strain gauges, temperature probes and vacuum sensors) and on remote-acquisition devices (laser ...

  1. Tracer-tracer relations as a tool for research on polar ozone loss

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rolf

    2010-07-01

    The report includes the following chapters: (1) Introduction: ozone in the atmosphere, anthropogenic influence on the ozone layer, polar stratospheric ozone loss; (2) Tracer-tracer relations in the stratosphere: tracer-tracer relations as a tool in atmospheric research; impact of cosmic-ray-induced heterogeneous chemistry on polar ozone; (3) quantifying polar ozone loss from ozone-tracer relations: principles of tracer-tracer correlation techniques; reference ozone-tracer relations in the early polar vortex; impact of mixing on ozone-tracer relations in the polar vortex; impact of mesospheric intrusions on ozone-tracer relations in the stratospheric polar vortex calculation of chemical ozone loss in the arctic in March 2003 based on ILAS-II measurements; (4) epilogue.

  2. Increased self-efficacy: the experience of high-intensity exercise of nursing home residents with dementia - a qualitative study.

    Science.gov (United States)

    Olsen, Cecilie Fromholt; Telenius, Elisabeth Wiken; Engedal, Knut; Bergland, Astrid

    2015-09-14

    There has been increasing interest in the use of non-pharmacological interventions, such as physical exercise, to improve the well-being of nursing home residents with dementia. For reasons regarding disease symptoms, persons with dementia might find it difficult to participate in exercise programs. Therefore, it is important to find ways to successfully promote regular exercise for patients in residential care. Several quantitative studies have established the positive effects of exercise on biopsychosocial factors, such as self-efficacy in older people; however, little is known regarding the qualitative aspects of participating in an exercise program among older people with dementia. From the perspective of residents, we explored the experiences of participating in a high-intensity functional exercise program among nursing home residents with dementia. The participants were eight elderly people with mild-to-moderate dementia. We conducted semi-structured interviews one week after they had finished a 10-week supervised high-intensity exercise program. We analyzed the data using an inductive content analysis. Five overreaching and interrelated themes emerged from the interviews: "Pushing the limits," "Being invested in," "Relationships facilitate exercise participation," "Exercise revives the body, increases independence and improves self-esteem" and "Physical activity is a basic human necessity--use it or lose it!" The results were interpreted in light of Bandura's self-efficacy theory. The exercise program seemed to improve self-efficacy through several mechanisms. By being involved, "being invested in" and having something expected of them, the participants gained a sense of empowerment in their everyday lives. The importance of social influences related to the exercise instructor and the exercise group was accentuated by the participants. The nursing home residents had, for the most part, positive experiences with regard to participating in the exercise program

  3. Partitioning Gas Tracer Technology for Measuring Water in Landfills

    Science.gov (United States)

    Briening, M. L.; Jakubowitch, A.; Imhoff, P. T.; Chiu, P. C.; Tittlebaum, M. E.

    2002-12-01

    between the point of tracer injection and tracer extraction because the partitioning tracer is retarded due to water in the landfill. The degree of tracer retardation can be used to determine the average water saturation between the injection and extraction points. This partitioning gas tracer test yields a large-scale estimate of the water saturation, is not affected by solid waste compaction or heterogeneity in the composition of the solid waste, and has been successfully tested in a recent field experiment in soils. We report the results from a series of laboratory experiments designed to evaluate this technology with various trash mixtures. Experimental conditions were selected to mimic the range of moisture conditions that may exist within municipal landfills. The influence of leachate composition and temperature on gas tracer partitioning were also evaluated. In our trash mixtures, the partitioning gas tracer test determined volumetric water contents that were within 12% of actual values. We discuss these data in detail and describe environmental conditions (e.g., temperature variations) that may affect the utility of the partitioning gas tracer test.

  4. Inert tracer wind resuspension as a function of wind speed, atmospheric stability, and initial tracer particle size

    International Nuclear Information System (INIS)

    Sehmel, G.A.; Lloyd, F.D.

    1979-01-01

    Wind-caused resuspension rates are being determined in three different, long-term, inert-tracer field experiments. Chemical results were recently received from an accumulated backlog of air filter samples. Resuspension rates are yet to be calculated from these data

  5. Slew-rate dependence of tracer magnetization response in magnetic particle imaging.

    Science.gov (United States)

    Shah, Saqlain A; Ferguson, R M; Krishnan, K M

    2014-10-28

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ 0 excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude ( H o ) and frequency ( ω ). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ 0 . For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate ( ωH o ) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories.

  6. Slew-rate dependence of tracer magnetization response in magnetic particle imaging

    Science.gov (United States)

    Shah, Saqlain A.; Ferguson, R. M.; Krishnan, K. M.

    2014-10-01

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ0 excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (Ho) and frequency (ω). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ0. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (ωHo) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories.

  7. Parents' experiences of their child being admitted to a paediatric intensive care unit: a qualitative study-like being in another world.

    Science.gov (United States)

    Dahav, Pia; Sjöström-Strand, Annica

    2018-03-01

    There is very little research on the parent's experiences of having a child admitted to a paediatric intensive care unit. Identifying and describing 'such experiences' could facilitate better parental support from the paediatric intensive care team and help the parents manage a stressful situation. This study aimed to describe parents' experiences of having their child admitted to a paediatric intensive care unit. Interviews were conducted with 12 parents whose children had been admitted to a paediatric intensive care unit. A qualitative design was used, and the interviews were analysed based on content analysis. The analysis revealed two categories: 'being involved' and 'being informed' with seven subcategories: 'caring for the parents', 'security and trust', 'altering the parental role', 'stress and fear', 'the importance of knowing', 'interaction in the care process' and 'being prepared'. An overarching theme emerged: the experience was 'like being in another world'. The study concludes that a child's admission to a paediatric intensive care unit is a stressful situation, and for the parents to be able to handle the anxiety and stress, they need to be informed of and involved in their child's care. The parents' experience when their child is admitted to a paediatric intensive care unit is fraught with a range of emotion and fear. There are indications that things such as good information, involvement and a positive experience of the transfer to the paediatric ward reduce the stress and anxiety associated with paediatric intensive care admission. The result of this study could be used as a basis for a post-paediatric intensive care follow-up service for the children and their families. © 2017 Nordic College of Caring Science.

  8. Tracer techniques in food industry

    International Nuclear Information System (INIS)

    Pertsovskij, E.S.; Sakharov, Eh.V.; Dolinin, V.A.

    1980-01-01

    The appicability of radioactive tracer techniques to process control in food industry are considered. Investigations in the field of food industry carried out using the above method are classified. The 1 class included investigations with preliminary preparation of a radioactive indicator and its following introduction in the system studied. The 2 class includes investigations based on the introduction in the system studied of a non-active indicator which is activated in a neutron flux being in samples selected in or after the process investigated. The 3 class includes studies based on investigations of natural radioactivity of certain nuclides in food stuff. The application of tracer techniques to the above classes of investigations in various fields of food industry and the equipment applied are considered in detail [ru

  9. The Accurate Particle Tracer Code

    OpenAIRE

    Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi

    2016-01-01

    The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and non-linear problems. Under the well-designed integrated and modularized framework, APT serves as a universal platform for researchers from different fields, such as plasma physics, accelerator physics, space science, fusio...

  10. The lived experiences of adult intensive care patients who were conscious during mechanical ventilation: a phenomenological-hermeneutic study.

    Science.gov (United States)

    Karlsson, Veronika; Bergbom, Ingegerd; Forsberg, Anna

    2012-02-01

    The aim of this study was to illuminate the lived experience of patients who were conscious during mechanical ventilation in an intensive care unit (ICU). Interviews with 12 patients assessed as being conscious during mechanical ventilation were conducted approximately one week after discharge from an ICU. The text was analysed using a phenomenological-hermeneutic method inspired by Ricoeur. Apart from breathlessness, voicelessness was considered the worst experience. The discomfort and pain caused by the tracheal tube was considerable. A feeling of being helpless, deserted and powerless because of their serious physical condition and inability to talk prompted the patients to strive for independence and recovery and made them willing to 'flow with' the treatment and care. Comments from the patients suggest that their suffering can be alleviated by communication, participation in care activities and companionship. A patient's endurance whilst conscious during mechanical ventilation seems to be facilitated by the presence of nurses, who mediate hope and belief in recovery, strengthening the patient's will to fight for recovery and survival. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. ICU-RESPECT: An index to assess patient and family experiences of respect in the intensive care unit.

    Science.gov (United States)

    Geller, Gail; Branyon, Emily D; Forbes, Lindsay K; Topazian, Rachel J; Weir, Brian W; Carrese, Joseph A; Beach, Mary Catherine; Sugarman, Jeremy

    2016-12-01

    The purpose of the study is to develop a brief index of patient and family experiences of respect in the intensive care unit (ICU). We designed a questionnaire with 44 items representing 12 themes that emerged from prior in-depth interviews with ICU patients and families. After pilot testing, items with minimal variability were eliminated. The resulting 21-item questionnaire was administered to patients and families in 5 adult ICUs. Psychometric analyses were conducted. Fifty-seven questionnaires were completed. Factor analysis resulted in a unidimensional scale consisting of 10 items with an α of .85 and an Eigen value of 11.3. Factor loadings ranged from 0.54 to 0.84, and item-test correlations ranged from 0.47 to 0.71. The mean total score was 7.25 out of a maximum of 10. Scores were lower for surgical than medical or disease-specific ICUs. The "ICU-RESPECT" index demonstrates high reliability and concurrent validity in ICU patients and families. Future research should validate this index in other ICU settings, assess its predictive validity, and evaluate different methods for maximizing response rate. As hospitals address patient experience more broadly in response to national metrics, the index could identify particular behaviors or ICUs that would benefit from interventions to enhance respectful treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Tracer Dispersion Within an Urban Environment.

    Science.gov (United States)

    Martin, D.; Shallcross, D.; Price, C.; Nickless, G.; Simmonds, P.

    2003-12-01

    The transport and dispersion of pollutants has extremely important implications for the environment on urban, regional and global scales. At the urban level localised emissions of both biogenic and anthropogenic pollutants can directly impact the health of the inhabitants. The DAPPLE (Dispersion of Air Pollutants and their Penetration into the Local Environment) project is a consortium of six universities, which involves a multidisciplinary approach to characterise relatively small-scale urban atmospheric dispersion including wind tunnel modelling, computer simulations, fieldwork and analysis. This work describes the tracer technology used to characterise atmospheric dispersion as well as preliminary results from the first tracer release experiment in Central London. A steady state finite duration release of both perfluoromethylcyclohexane (PMCH) and Sulfur Hexafluoride (SF6 ) was performed as part of the first DAPPLE campaign. These compounds were released over a fifteen-minute integrated time period with the SF6 release staggered one and a half minutes behind the PMCH. The low background concentrations of PMCH (~ 5 x 10-3 pptv) and SF6 (~5pptv) along with non-depositing and non-reactive characteristics allow for the implementation of near ideal fluid dynamic experiments. Sampling consists of a multiport ladder fitting with solenoid valves onto which a succession of sampling bags is attached. These are electrically actuated in sequential order with an integrated sampling time of three minutes. The samplers are placed at various receptor positions in the DAPPLE zone in predefined positions designed to best validate these model simulated meteorological dispersion processes. Analysis of PMCH is carried out using sample enrichment on carbon based adsorbents, separation by capillary Gas Chromatography and Negative Ion Chemical Ionisation Mass Spectrometry detection (GC-MS-NICI). SF6 concentrations are determined using fixed volume loop injections with Gas

  13. Determination of the Isotopic Enrichment of13C- and2H-Labeled Tracers of Glucose Using High-Resolution Mass Spectrometry: Application to Dual- and Triple-Tracer Studies.

    Science.gov (United States)

    Trötzmüller, Martin; Triebl, Alexander; Ajsic, Amra; Hartler, Jürgen; Köfeler, Harald; Regittnig, Werner

    2017-11-21

    Multiple-tracer approaches for investigating glucose metabolism in humans usually involve the administration of stable and radioactive glucose tracers and the subsequent determination of tracer enrichments in sampled blood. When using conventional, low-resolution mass spectrometry (LRMS), the number of spectral interferences rises rapidly with the number of stable tracers employed. Thus, in LRMS, both computational effort and statistical uncertainties associated with the correction for spectral interferences limit the number of stable tracers that can be simultaneously employed (usually two). Here we show that these limitations can be overcome by applying high-resolution mass spectrometry (HRMS). The HRMS method presented is based on the use of an Orbitrap mass spectrometer operated at a mass resolution of 100 000 to allow electrospray-generated ions of the deprotonated glucose molecules to be monitored at their exact masses. The tracer enrichment determination in blood plasma is demonstrated for several triple combinations of 13 C- and 2 H-labeled glucose tracers (e.g., [1- 2 H 1 ]-, [6,6- 2 H 2 ]-, [1,6- 13 C 2 ]glucose). For each combination it is shown that ions arising from 2 H-labeled tracers are completely differentiated from those arising from 13 C-labeled tracers, thereby allowing the enrichment of a tracer to be simply calculated from the observed ion intensities using a standard curve with curve parameters unaffected by the presence of other tracers. For each tracer, the HRMS method exhibits low limits of detection and good repeatability in the tested 0.1-15.0% enrichment range. Additionally, due to short sample preparation and analysis times, the method is well-suited for high-throughput determination of multiple glucose tracer enrichments in plasma samples.

  14. Comparison of tracer techniques for monitoring sewer losses.

    Science.gov (United States)

    Revitt, D Michael; Ellis, J Bryan; Paterakis, Nikolaos

    2006-05-01

    Two different experimental techniques employing conservative tracers to determine exfiltration losses in a sewer system are reported. Both techniques compare the in-sewer responses measured along designated indicator and reference sections to assess the level of exfiltration although with different degrees of reliability. The experimental and interpretation errors associated with a pulse dosing technique, in which Rhodamine WT is used as the single tracer, are described. The estimation of exfiltration requires the comparison of indicator and reference peaks which need to be well resolved and reproducible in order to provide realistic results. A more consistent technique involves the continuous dosing of two different tracers with the objective of producing simultaneous downstream peak tracer concentrations. Any errors due to flow variations are eliminated and the longer measurement period allows both peak and background concentrations to be more accurately determined. Rhodamine WT, Li and Br were used in different combinations over the approximately 20 min duration of each continuous dosing experiment and were found to demonstrate conservative behaviours with measured recoveries of 97.6-100.6%, 97.3-101.4% and 108.4-109.2%, respectively. The analytical problems associated with the determination of the different tracers in sewage are described and are shown to be responsible for the reduced accuracy of the results associated with the use of Br. The preferred combination of tracers is Rhodamine WT as the indicator and Li as the reference and these are shown to be capable of estimating sewer losses to an accuracy of +/-1.0% using the continuous dosing approach.

  15. Dynamics and mechanics of bed-load tracer particles

    Directory of Open Access Journals (Sweden)

    C. B. Phillips

    2014-12-01

    Full Text Available Understanding the mechanics of bed load at the flood scale is necessary to link hydrology to landscape evolution. Here we report on observations of the transport of coarse sediment tracer particles in a cobble-bedded alluvial river and a step-pool bedrock tributary, at the individual flood and multi-annual timescales. Tracer particle data for each survey are composed of measured displacement lengths for individual particles, and the number of tagged particles mobilized. For single floods we find that measured tracer particle displacement lengths are exponentially distributed; the number of mobile particles increases linearly with peak flood Shields stress, indicating partial bed load transport for all observed floods; and modal displacement distances scale linearly with excess shear velocity. These findings provide quantitative field support for a recently proposed modeling framework based on momentum conservation at the grain scale. Tracer displacement is weakly negatively correlated with particle size at the individual flood scale; however cumulative travel distance begins to show a stronger inverse relation to grain size when measured over many transport events. The observed spatial sorting of tracers approaches that of the river bed, and is consistent with size-selective deposition models and laboratory experiments. Tracer displacement data for the bedrock and alluvial channels collapse onto a single curve – despite more than an order of magnitude difference in channel slope – when variations of critical Shields stress and flow resistance between the two are accounted for. Results show how bed load dynamics may be predicted from a record of river stage, providing a direct link between climate and sediment transport.

  16. The experience of communication difficulties in critically ill patients in and beyond intensive care: Findings from a larger phenomenological study.

    Science.gov (United States)

    Tembo, Agness C; Higgins, Isabel; Parker, Vicki

    2015-06-01

    Communication difficulties in intensive care units (ICU) with critically ill patients have been well documented for more than three decades. However, there is only a paucity of literature that has explored communication difficulties beyond the ICU environment. This paper discusses the experience of communication difficulties in critically ill patients in ICU and beyond as part of findings from a larger study that explored the lived experiences of critically ill patients in ICU in the context of daily sedation interruption (DSI). The aim of the study was to describe the lived experience of people who experienced critical illness in ICU using a hermeneutic phenomenological approach in the DSI context. Twelve participants aged between 20 and 76 years with an ICU stay ranging from 3 to 36 days were recruited from a 16 bed ICU in a large regional referral hospital in New South Wales (NSW), Australia. Participants were intubated, mechanically ventilated and subjected to (DSI) during their critical illness in ICU. In-depth face to face interviews with participants were conducted at two weeks after discharge from ICU and at six to eleven months later. Interviews were audio taped and transcribed. Thematic analysis using van Manen's (1990) method was completed. The overarching theme; 'Being in limbo' and subthemes 'Being disrupted'; 'Being imprisoned' and 'Being trapped' depict the main elements of the experience. This paper discusses communication difficulties in critically ill patients as one of the main findings relating to the theme 'Being trapped'. Participants' reports of communication difficulties in ICU are similar to those reported by patients in other studies where DSI was not used. However, not many studies have reported ongoing communication difficulties after ICU hospitalisation. Recommendations are made for new models of care and support to mitigate critically ill patients' communication concerns in ICU and for further research into the causes and treatment to

  17. Sprinkling experiments to simulate high and intense rainfall for process based investigations - a comparison of two methods

    Science.gov (United States)

    Müller, C.; Seeger, M.; Schneider, R.; Johst, M.; Casper, M.

    2009-04-01

    Land use and land management changes affect runoff and erosion dynamics. So, measures within this scope are often directed towards the mitigation of natural hazards such as floods and landslides. However, the effects of these changes (e.g. in soil physics after reforestation or a less extensive agriculture) are i) detectable first many years later or ii) hardly observable with conventional methods. Therefore, sprinkling experiments are frequently used for process based investigations of near-surface hydrological response as well as rill and interrill erosion. In this study, two different sprinkling systems have been applied under different land use and at different scales to elucidate and quantify dominant processes of runoff generation, as well as to relate them to the detachment and transport of solids. The studies take place at the micro-scale basin Zemmer and Frankelbach in Germany. At the Zemmer basin the sprinkling experiments were performed on agricultural land while the experiments in Frankelbach were performed at reforested sites. The experiments were carried out i) with a small mobile rainfall simulator of high rainfall intensities (40 mm h-1) and ii) with a larger one covering a slope segment and simulating high rainfall amounts (120 mm in 3 days). Both methods show basically comparable results. On the agricultural sites clear differences could be observed between different soil management types: contrasting to the conventionally tilled soils, deep loosened soils (in combination with conservative tillage) do not produce overland flow, but tend to transfer more water by interflow processes, retaining large amounts in the subsoil. For the forested sites runoff shows a high variability as determined the larger and the smaller rainfall simulations. This variability is rather due to the different forest and soil types than to methodologically different settings of the sprinkling systems. Both rainfall simulation systems characterized the runoff behavior in a

  18. Relative distance between tracers as a measure of diffusivity within moving aggregates

    Science.gov (United States)

    Pönisch, Wolfram; Zaburdaev, Vasily

    2018-02-01

    Tracking of particles, be it a passive tracer or an actively moving bacterium in the growing bacterial colony, is a powerful technique to probe the physical properties of the environment of the particles. One of the most common measures of particle motion driven by fluctuations and random forces is its diffusivity, which is routinely obtained by measuring the mean squared displacement of the particles. However, often the tracer particles may be moving in a domain or an aggregate which itself experiences some regular or random motion and thus masks the diffusivity of tracers. Here we provide a method for assessing the diffusivity of tracer particles within mobile aggregates by measuring the so-called mean squared relative distance (MSRD) between two tracers. We provide analytical expressions for both the ensemble and time averaged MSRD allowing for direct identification of diffusivities from experimental data.

  19. The propagation of Escherichia Coli and of conservative tracers. A comparison

    International Nuclear Information System (INIS)

    Alexander, I.; Seiler, K.P.

    1982-01-01

    The propagation of Escherichia Coli (ATCC 11229, Gelsenkirchen) is compared with that of conservative tracers in groundwater. The experiments were performed with injection quantities of 10 7 , 10 8 , 10 10 and 10 11 of Escherichia Coli. Both, bacteria and conservative tracers pass their maximum at the same instant in the observation gauges. With injection quantities of more than 10 8 , the propagation of the Escherichia Coli sets in at the same time as it begins with the dyes. When the quantities range below 10 8 , the propagation begins after that of conservative tracers, because Coli bacteria were measured with a lower degree of detecting sensitivity than the tracers. With Coli injection quantities ranging above 10 10 , an increased filtering of these bacteria can be observed. Coli bacteria propagate more laterally than conservative tracers, however it could not be proved that this lateral propagation depends on the bacteria concentration. (orig.) [de

  20. Fathers' experiences with their preterm babies admitted to neonatal intensive care unit: A multi-method study.

    Science.gov (United States)

    Stefana, Alberto; Padovani, Ezio Maria; Biban, Paolo; Lavelli, Manuela

    2018-01-19

    The aim of this study was to investigate fathers' emotional experiences of their infant's preterm birth and subsequent stay in neonatal intensive care unit. When a baby is born preterm, there is also the premature interruption of the process of preparation for fatherhood. As a result, the impact on fathers of the preterm birth can bring negative consequences for the development of father-infant relationship. A multi-method approach was used which included ethnographic observation, semi-structured interviews with fathers, a self-report questionnaire and clinical information between September 2015-March 2017. Data were analysed using a mixed-method: a thematic analysis of data from the interviews and quantitative analyses to detect possible clusters of fathers' emotional experiences and associations between clusters and fathers' and/or infants' characteristics. Two clusters were identified. The "fathers-of-preterm-infants" touched their baby as soon as they were given the opportunity and without fear that they would harm their infant. They were struck by their baby's physical appearance. In contrast, the "preterm fathers" preferred not to touch their baby when first given the chance, for fear of breaking/damaging/infecting her/him. They were struck both by the baby's physical appearance and by the technology/equipment around her/him and were afraid that their infant would die. All the "fathers-of-preterm-infants", but only just over half of the "preterm fathers", were actively engaged in their infant's care. Clusters were associated with the infant's gestational age. Fathers of preterm infants should receive personalized support specifically addressed to them and based on the infant's gestational age. © 2018 John Wiley & Sons Ltd.

  1. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  2. Experiences and needs of families regarding prognostic communication in an intensive care unit: supporting families at the end of life.

    Science.gov (United States)

    Gutierrez, Karen M

    2012-01-01

    This article reports the results of a study designed to explore the experiences and needs of family members for prognostic communication at end of life in an intensive care unit (ICU). Subjects in this qualitative study included 20 family members of patients at high risk for death in 1 adult medical/surgical ICU. All subjects were interviewed once utilizing a semistructured interview format, with approximately half interviewed multiple times during the ICU stay. Families described 5 themes of information-related "work": (1) hearing and recalling, (2) accessing, (3) interpreting, (4) retaining, and (5) utilizing information for decision making. Barriers, including accessing physicians and cognitive issues from high levels of stress, made this work difficult. Families described a need for prognostic information, especially if the prognosis was poor. Because hearing this news was difficult, they needed it communicated with respect, sensitivity, and compassion. Suggestions for clinical practice to support families in their information-related work are presented. Overall, the importance of providers approaching communication from a holistic perspective, extending beyond simply passing on information, is emphasized. Viewing communication as a therapeutic modality, and communicating with compassion, sensitivity, and a genuine sense of caring, can help provide both the information and the emotional support and comfort families desperately need.

  3. Experiences with the use of conservative tracers as an aid in transferring lysimeter results to the open field; Erfahrungen beim Einsatz von konservativen Tracern als Hilfsmittel zur Uebertragung von Lysimeterergebnissen auf Freilandflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, J.; Meissner, R.; Rupp, H. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Falkenberg (Germany). Lysimeterstation; Mueller, L.; Eulenstein, F. [Zentrum fuer Agrarlandschafts- und Landnutzungsforschung e.V. (ZALF), Muencheberg (Germany)

    1999-02-01

    Four lysimeter trials performed on an IS-type soil yielded an almost constant range of displacement of a tracer front (NO{sub 3} front) of 4.0 to 4.5 mm / l of seepage water (referred to a surface area of 1 m-2 and a depth of 1 m). This was experimental confirmation of a tentatively formulated simplified relationship between seepage water volume, vertical tracer displacement, and field capacity. The results were also in very good agreement with those of a control study in the open field carried out under similar hydrological, pedological, and agrotechnical conditions using lysimeters and Cl tracers for determining quantities of seepage water formation. As the present lysimeter trials mirror soil hydrological processes in the open field with sufficient accuracy, they appear well suited to take the place of the so often lacking territorial data as a means of validating mathematical models describing seepage-water-bound material export. [Deutsch] Auf der Basis von 4 Lysimeterversuchen konnte fuer die Bodenart IS ein nahezu konstanter Wertebereich fuer die Verlagerung einer Tracerfront (NO{sub 3}-Front) in Hoehe von 4,0 bis 4,5 mm/l Sickerwasser (bezogen auf eine Oberflaeche von 1 m{sup 2} und eine Tiefe von 1 m) ermittelt werden. Damit konnte die vereinfachte Beziehung zwischen Sickerwassermenge, Tracerverlagerungstiefe und Feldkapazitaet experimentell bestaetigt werden. Ein Vergleich zur Bestimmung der Sickerwassermengenbildung mit Hilfe von Lysimetern und durch Einsatz von Cl-Tracern unter aehnlich hydrologischen, pedologischen und agrotechnischen Bedingungen im Freiland wies eine hohe Uebereinstimmung auf. Da die hier durchgefuehrten Lysimeteruntersuchungen bodenhydrologische Prozesse von Freilandflaechen mit ausreichender Genauigkeit widerspieglen, erscheinen sie anstelle oft fehlender Gebietskenndaten zur Validierung von mathematischen Modellen zur Beschreibung sickerwassergebundener Stoffaustraege gut geeignet. (orig.)

  4. Use of tracers to quantify subsurface flow through a mining pit.

    Science.gov (United States)

    Schladow, S Geoffrey; Clark, Jordan F

    2008-12-01

    Three independent tracer experiments were conducted to quantify the through-flow of water from Herman Pit, an abandoned mercury (Hg) mine pit adjacent to Clear Lake, California, USA. The tracers used were Rhodamine-WT, sulfur hexafluoride, and a mixture of sulfur hexafluoride and neon-22. The tracers were injected into Herman Pit, a generally well-mixed water body of approximately 81,000 m2, and the concentrations were monitored in the mine pit, observation wells, and the lake for 2-3 months following each injection. The results for all three experiments showed that the tracer arrived at certain observation wells within days of injection. Comparing all the well data showed a highly heterogeneous response, with a small number of wells showing this near-instantaneous response and others taking months before the tracer was detectable. Tracer was also found in the lake on four occasions over a one-month period, too few to infer any pattern but sufficient to confirm the connection of the two water bodies. Using a simple mass balance model it was possible to determine the effective loss rate through advection for each of the tracers and with this to estimate the through-flow rate. The through-flow rate for all three experiments was approximately 630 L/s, at least 1-2 orders of magnitude larger than previous estimates, all of which had been based on geochemical inferences or other indirect measures of the pit through-flow.

  5. Borehole flowmeter logging for the accurate design and analysis of tracer tests.

    Science.gov (United States)

    Basiricò, Stefano; Crosta, Giovanni B; Frattini, Paolo; Villa, Alberto; Godio, Alberto

    2015-04-01

    Tracer tests often give ambiguous interpretations that may be due to the erroneous location of sampling points and/or the lack of flow rate measurements through the sampler. To obtain more reliable tracer test results, we propose a methodology that optimizes the design and analysis of tracer tests in a cross borehole mode by using vertical borehole flow rate measurements. Experiments using this approach, herein defined as the Bh-flow tracer test, have been performed by implementing three sequential steps: (1) single-hole flowmeter test, (2) cross-hole flowmeter test, and (3) tracer test. At the experimental site, core logging, pumping tests, and static water-level measurements were previously carried out to determine stratigraphy, fracture characteristics, and bulk hydraulic conductivity. Single-hole flowmeter testing makes it possible to detect the presence of vertical flows as well as inflow and outflow zones, whereas cross-hole flowmeter testing detects the presence of connections along sets of flow conduits or discontinuities intercepted by boreholes. Finally, the specific pathways and rates of groundwater flow through selected flowpaths are determined by tracer testing. We conclude that the combined use of single and cross-borehole flowmeter tests is fundamental to the formulation of the tracer test strategy and interpretation of the tracer test results. © 2014, National Ground Water Association.

  6. Numerical study of tracers transport by a mesoscale convective system over West Africa

    Directory of Open Access Journals (Sweden)

    C. Barthe

    2011-05-01

    Full Text Available A three-dimensional cloud-resolving model is used to investigate the vertical transport from the lower to the upper troposphere in a mesoscale convective system (MCS that occurred over Niger on 15 August 2004. The redistribution of five passive tracers initially confined in horizontally homogeneous layers is analyzed. The monsoon layer tracer (0–1.5 km is the most efficiently transported in the upper troposphere with concentrations 3 to 4 times higher than the other tracers in the anvil. On the contrary the African Easterly Jet tracer (~3 km has the lowest contribution above 5 km. The vertical profiles of the mid-troposphere tracers (4.5–10 km in the MCS exhibit two peaks: one in their initial layers, and the second one at 13–14 km altitude, underlying the importance of mid-tropospheric air in feeding the upper troposphere. Mid-tropospheric tracers also experience efficient transport by convective downdrafts with a consequent increase of their concentrations at the surface. The concentration of the upper troposphere–lower stratosphere tracer exhibits strong gradients at the edge of the cloud, meaning almost no entrainment of this tracer into the cloud. No downward transport from the upper troposphere is simulated below 5 km. A proxy for lightning produced NOx is transported preferentially in the forward anvil in the upper troposphere. Additionally, lateral inflows significantly contribute to the updraft and downdraft airflows emphasizing the three-dimensional structure of the West African MCSs.

  7. THE NEW YORK CITY URBAN DISPERSION PROGRAM MARCH 2005 FIELD STUDY: TRACER METHODS AND RESULTS.

    Energy Technology Data Exchange (ETDEWEB)

    WATSON, T.B.; HEISER, J.; KALB, P.; DIETZ, R.N.; WILKE, R.; WIESER, R.; VIGNATO, G.

    2005-10-01

    The Urban Dispersion Program March 2005 Field Study tracer releases, sampling, and analytical methods are described in detail. There were two days where tracer releases and sampling were conducted. A total of 16.0 g of six tracers were released during the first test day or Intensive Observation Period (IOP) 1 and 15.7 g during IOP 2. Three types of sampling instruments were used in this study. Sequential air samplers, or SAS, collected six-minute samples, while Brookhaven atmospheric tracer samplers (BATS) and personal air samplers (PAS) collected thirty-minute samples. There were a total of 1300 samples resulting from the two IOPs. Confidence limits in the sampling and analysis method were 20% as determined from 100 duplicate samples. The sample recovery rate was 84%. The integrally averaged 6-minute samples were compared to the 30-minute samples. The agreement was found to be good in most cases. The validity of using a background tracer to calculate sample volumes was examined and also found to have a confidence level of 20%. Methods for improving sampling and analysis are discussed. The data described in this report are available as Excel files. An additional Excel file of quality assured tracer data for use in model validation efforts is also available. The file consists of extensively quality assured BATS tracer data with background concentrations subtracted.

  8. Mechanical design control and implementation of a new movable intensity profile beamline monitor for the TRIUMF parity experiment 497

    Science.gov (United States)

    Ries, Thomas C.

    1995-05-01

    Two new movable beam intensity profile monitors have been installed into the TRIUMF Parity Experiment 497 Beamlines. Each unit serves two functions. Firstly, the beam median position, in a plane normal to the beam, is detected by split plate Secondary Emission Monitors. This information is used to lock the beam into the position of the movable monitor to within a few μm's via high band width ferrite core steering magnets operating in tandem in a closed loop servo feedback control system. Secondly, the beam profile and intensity is detected via a multi-wire secondary emission non-movable monitor, where the data provides high precision values regarding centroidal positions and profiles. The centroid position of the beam is statistically determined to an accuracy of ±10 μm from a data record length of 1 second. The design of each device adheres to strict standards of mechanically rigid construction. The split plate SEM accuracy and repeatability is better than 15 μm with an absolute resolution limit of 0.4 μm. Maximum travel is 2 inches in the vertical plane. Since the device is mechanically modular and both degrees of freedom are combined into a single mechanical unit, fast and easy handling is possible for maintenance in radioactive areas. The actuators are dc servo motors with tachometers driven by linear servo power amplifiers. These amplifiers are used in lieu of pulse width modulated amps to eliminate noise produced by the switching circuits. Position sensing is done by variable reluctance type absolute rotary encoders providing 16 bit resolution over the full range of travel. Positioning is done manually using a self centring potentiometer on the control panel that provides a ± velocity command signal to the power amplifiers. This configuration ensures good controllability over a very large range of positioning speeds hence making 0.4 μm incremental positioning possible, as well as, fast relocations over large relative distances. The precision movement

  9. Principles and techniques of gamma ray tracers

    International Nuclear Information System (INIS)

    Claxton, K.T.

    1978-01-01

    Radioactive tracer techniques provide a very sensitive means of studying physical and chemical processes in a whole variety of different media. Some of the techniques and principles of radioactive tracers and their application to practical engineering systems are discussed. Information which has been found useful in the design of high temperature liquid sodium facilities employing radio-tracers, is presented. The report deals solely with the use of gamma-emitting species as the tracer. These find particular application for in-situ studies on engineering systems where the highly penetrating properties of gamma rays are needed for detection through strongly absorbent media such as stainless steel pepe walls. (author)

  10. EFFICIENT HYDROLOGICAL TRACER-TEST DESIGN (EHTD ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for establishing flow trajectories and hydrologic connections and for determining basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed that combines basic measured field parameters (e.g., discharge, distance, cross-sectional area) in functional relationships that describe solute-transport processes related to flow velocity and time of travel. The new method applies these initial estimates for time of travel and velocity to a hypothetical continuously stirred tank reactor as an analog for the hydrologic flow system to develop initial estimates for tracer concentration and axial dispersion, based on a preset average tracer concentration. Root determination of the one-dimensional advection-dispersion equation (ADE) using the preset average tracer concentration then provides a theoretical basis for an estimate of necessary tracer mass.Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to

  11. Use of artificial tracers in hydrology

    International Nuclear Information System (INIS)

    1991-05-01

    The IAEA has convened an Advisory Group Meeting with the following objectives: To define the role of artificial radioactive tracers for water tracing in comparison with other non-radioactive tracers. To evaluate the real needs of artificial radioactive tracers in hydrology. To identify the fields for which artificial radioactive tracers are useful as well as those in which they can be substituted by other tracers. To discuss the strategy to be adopted to overcome the difficulties derived from the restrictions on the use of radioactive tracers in hydrology. The meeting was held at IAEA Headquarters from 19 to 22 March 1990, and was attended by 30 participants from 15 Member States. The conclusions and recommendations are that the use of artificial radioactive tracers should be restricted to cases where other tracers cannot be used or do not provide the same quality of information. Tritium, iodine-131, bromine-82, chromium-51 in the form of Cr-EDTA, technetium-99m obtained from 99 Mo-generators and gold-198 as an adsorbable tracer are, practically, the only radionuclides used for water tracing. The use of other radionuclides for this purpose does not appear to be necessary, possible and/or convenient. Refs, figs and tabs

  12. Tracer a application in marine outfall studies

    International Nuclear Information System (INIS)

    Genders, S.

    1979-01-01

    The applicability of radioactive and fluorescent tracers for field studies to predict or investigate waste water transport and dispersion from marine outfalls is evaluated. The application of either instantaneous or continuous tracer release, 'in situ' detection of tracers and data processing are considered. The necessity of a combined use of tracer techniques and conventional hydrographic methods for a statistical prediction of transport and dillution of waste water are pointed out. A procedure to determine an outlet distance from the coast, which satisfy bathing water criteria is outlined. (M.A.) [pt

  13. Tracer-Test Planning Using the Efficient Hydrologic Tracer-Test Design (Ehtd) Program (2003)

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for establishing flow trajectories and hydrologic connections and for determining basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test ...

  14. Survival advantage with decitabine versus intensive chemotherapy in patients with higher risk myelodysplastic syndrome: comparison with historical experience.

    Science.gov (United States)

    Kantarjian, Hagop M; O'Brien, Susan; Huang, Xuelin; Garcia-Manero, Guillermo; Ravandi, Farhad; Cortes, Jorge; Shan, Jianqin; Davisson, Jan; Bueso-Ramos, Carlos E; Issa, Jean-Pierre

    2007-03-15

    Decitabine, a hypomethylating agent, is active and has been approved for the treatment of myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia. Intensive chemotherapy is an accepted form of therapy for patients with higher risk MDS. The comparative efficacy of these 2 forms of treatment in MDS is unknown. The objective of the current study was to compare the efficacy and toxicity profiles of decitabine and intensive chemotherapy in MDS. The authors compared lower intensity decitabine therapy (n = 115 patients) with intensive chemotherapy (as it is used in acute myeloid leukemia [AML]) in patients with higher risk MDS. Two comparisons were made with a cohort of 376 historic patients (from 1995 to 2005): The first comparison included a subcohort of 115 patients (Group A) who matched the 115 decitabine study patients according to age, International Prognostic Scoring System, and cytogenetics; and the second comparison included the whole cohort of 376 patients without matching (Group B). A multivariate analysis was performed for outcome. The complete remission (CR) rate according to AML criteria was 43% with decitabine, 46% with intensive chemotherapy in Group A, and 52% with intensive chemotherapy in Group B. Compared with Group A, mortality at 6 weeks was 3% with decitabine versus 13% with intensive chemotherapy (P = .006) and, at 3 months, 7% with decitabine versus 23% with intensive chemotherapy (P = .001). Survival was better with decitabine versus intensive chemotherapy in Group A (median survival: 22 months vs 12 months; P accounting for the independent prognostic effect of pretreatment factors. In this analysis, decitabine was associated with a survival advantage compared with intensive chemotherapy in patients with higher risk MDS. Future studies should evaluate prospectively the results of decitabine versus intensive chemotherapy in this setting.

  15. Suitable activated carbon-13 tracer techniques

    International Nuclear Information System (INIS)

    Zhang Weicheng; Peng Xiuru; Wang Yuhua

    1995-12-01

    Feasibility and applicability studies of the proton induced gamma ray emission (PIGE) have been performed. The graphite was firstly bombarded at various proton energies to determine gamma ray yield (and, thus, sensitivities) for the reaction of interest. The accuracy for the determination of 13 C abundance was checked, and the precision with which this value and ratios 13 C/ 12 C may be obtained was established by repetitive analysis samples. The performance of different standards in this determination was assessed. The mathematical treatment was developed for the determination of 13 C abundance in tracer studies, and to derive the equations that govern this method of analysis from first principles, to arrive finally at a simple expression by virtue of the observed regularities. The system was calibrated by measuring the gamma ray yield form the 12 C (p, γ) 13 N and 13 C(p,γ) 14 N reaction as a function of known 13 C enrichment. Using this experimentally determined calibration curve, unknown materials can be assayed. This technique is applicable to the analysis of samples with 13 C enrichments between 0.1% and 90%. The samples of human breath natural samples were analyzed against graphite and Cylinder CO 2 standards. Relative standard deviations were 13 C abundance, an increase in 13 C per cent isotopic abundance from the natural 1.11% (average) to only 1.39% may be ascertained. Finally, PIGE is compared with more classical techniques for analysis of 13 C tracer experiments. Ease and speed are important advantages of this technique over mass spectrometry, and its error is compatible with the natural variation of biological results. (9 refs., 11 figs., 9 tabs.)

  16. Multi-centre experience of implementing image-guided intensity-modulated radiotherapy using the TomoTherapy platform

    International Nuclear Information System (INIS)

    Dean, J.C.; Tudor, G.S.J.; Mott, J.H.; Dunlop, P.R.; Morris, S.L.; Harron, E.C.; Christian, J.A.; Sanghera, P.; Elsworthy, M.; Burnet, N.G.

    2013-01-01

    Use of image guided (IG) intensity modulated radiotherapy (IMRT) is increasing, and helical tomotherapy provides an effective, integrated solution. Practical experience of implementation, shared at a recent UK TomoTherapy Users' meeting, may help centres introducing these techniques using TomoTherapy or other platforms. Seven centres participated, with data shared from 6, varying from 2500 - 4800 new patients per year. Case selection of patients “most likely” to benefit from IG-IMRT was managed in all centres by multi-professional groups comprising clinical oncologists, physicists, treatment planners and radiographers. Radical treatments ranged from 94% to 100%. The proportions of tumour types varied substantially: head and neck: range 0%–100% (mean of centres 50%), prostate: 3%–96% (mean of centres 28%). Head and neck cases were considered most likely to benefit from IMRT, prostate cases from IGRT, or IG-IMRT if pelvic nodes were being treated. IMRT was also selected for complex target volumes, to avoid field junctions, for technical treatment difficulties, and retreatments. Across the centres, every patient was imaged every day, with positional correction before treatment. In one centre, for prostate patients including pelvic treatment, the pelvis was also imaged weekly. All centres had designed a ‘ramp up’ of patient numbers, which was similar in 5. One centre, treating 96% prostate patients, started with 3 and increased to 36 patients per day within 3 months. The variation in case mix implies wide applicability of IG-IMRT. Daily on-line IGRT with IMRT can be routinely implemented into busy departments

  17. Tracers for Characterizing Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karen Wright; George Redden; Carl D. Palmer; Harry Rollins; Mark Stone; Mason Harrup; Laurence C. Hull

    2010-02-01

    Information about the times of thermal breakthrough and subsequent rates of thermal drawdown in enhanced geothermal systems (EGS) is necessary for reservoir management, designing fracture stimulation and well drilling programs, and forecasting economic return. Thermal breakthrough in heterogeneous porous media can be estimated using conservative tracers and assumptions about heat transfer rates; however, tracers that undergo temperature-dependent changes can provide more detailed information about the thermal profile along the flow path through the reservoir. To be effectively applied, the thermal reaction rates of such temperature sensitive traces must be well characterized for the range of conditions that exist in geothermal systems. Reactive tracers proposed in the literature include benzoic and carboxylic acids (Adams) and organic esters and amides (Robinson et al.); however, the practical temperature range over which these tracers can be applied (100-275°C) is somewhat limited. Further, for organic esters and amides, little is known about their sorption to the reservoir matrix and how such reactions impact data interpretation. Another approach involves tracers where the reference condition is internal to the tracer itself. Two examples are: 1) racemization of polymeric amino acids, and 2) mineral thermoluminescence. In these cases internal ratios of states are measured rather than extents of degradation and mass loss. Racemization of poly-L-lactic acid (for example) is temperature sensitive and therefore can be used as a temperature-recording tracer depending on the rates of racemization and stability of the amino acids. Heat-induced quenching of thermoluminescence of pre-irradiated LiF can also be used. To protect the tracers from alterations (extraneous reactions, dissolution) in geothermal environments we are encapsulating the tracers in core-shell colloidal structures that will subsequently be tested for their ability to be transported and to protect the

  18. "Learning Is an Endless Journey for Anyone": Undergraduate Awareness, Experiences and Perceptions of the Research Culture in a Research-Intensive University

    Science.gov (United States)

    Spronken-Smith, Rachel; Mirosa, Romain; Darrou, Martine

    2014-01-01

    Our study explored undergraduates' experiences of the research culture at a research-intensive university in southern New Zealand. In 2009, 1281 students responded to a survey that probed aspects of the research culture. Data were analysed through descriptive statistics and an inductive analysis of comments. Survey results for final-year students…

  19. The impact of center experience on results of reduced intensity:allogeneic hematopoietic SCT for AML. An analysis from the Acute Leukemia Working Party of the EBMT

    DEFF Research Database (Denmark)

    Giebel, S; Labopin, M; Mohty, M

    2013-01-01

    Allogeneic hematopoietic SCT with reduced-intensity conditioning (RIC-HSCT) is increasingly adopted for the treatment of older adults with AML. Our goal was to verify for the first time, if center experience influences outcome of RIC-HSCT. Results of 1413 transplantations from HLA-matched related...

  20. Are Psychophysical Scales of Intensities the Same or Different when Stimuli Vary on Other Dimensions? Theory with Experiments Varying Loudness and Pitch

    Science.gov (United States)

    Luce, R. Duncan; Steingrimsson, Ragnar; Narens, Louis

    2010-01-01

    Most studies concerning psychological measurement scales of intensive attributes have concluded that these scales are of ratio type and that the psychophysical function is closely approximated by a power function. Experiments show, for such cases, that a commutativity property must hold under either successive increases or successive decreases…

  1. Innovative use of a microbial tracer for measuring groundwater through a fractured matrix

    International Nuclear Information System (INIS)

    Strong-Gunderson, J.M.

    1995-01-01

    Site characterization for ground water remediation activities is limited by the one's ability to visualize the complexity of the subsurface environment. Currently, a variety of dyes, colloids, gases, etc., are used to monitor and estimate ground water flow and contaminant transport. The author has recently identified a new, innovative colloidal tracer that is a non-hazardous bacterium that is detectable at very low concentrations (ng/kg), and can provide real-time analysis (3--5 min) for measuring colloid transport. The tracer is the ice nucleating active (INA) bacterium Pseudomonas syringae. The assay conditions require measuring the freezing point of the sample (e.g., ground water and soil slurries). Typically, 10--100 microL drops of water will not freeze until -15 to -20 C. However, if the tracer is present the water will freeze at -3 to -7 C. This increase in the freezing point can only be due to the presence of the tracer and this phenomenon is well documented in the plant pathology and low-temperature biology literature but has only now been applied to site characterization and remediation activities. Laboratory experiments have identified the stability of the tracer in the presence of a variety of ground water contaminants (> 100 ppm) and it is stable over a pH range of 2.3--10.0. The tracer has been demonstrated in conjunction with other commonly used tracers at a variety of field sites: (1) a drilling tracer to identify potential cross contamination, and as a colloid/bacterial tracer in (2) a hydrofracturing demonstration, (3) a horizontal recirculation well system, (4) a fractured karst matrix, and (5) a radioactive contaminated site. The data from these demonstrations have provided additional information about site characteristics including faster ground water flow rates than previously identified and due to its low sensitivities better distribution into a clay matrix than estimated by the bromide tracer

  2. Combining natural and man-made DNA tracers to advance understanding of hydrologic flow pathway evolution

    Science.gov (United States)

    Dahlke, H. E.; Walter, M. T.; Lyon, S. W.; Rosqvist, G. N.

    2014-12-01

    Identifying and characterizing the sources, pathways and residence times of water and associated constituents is critical to developing improved understanding of watershed-stream connections and hydrological/ecological/biogeochemical models. To date the most robust information is obtained from integrated studies that combine natural tracers (e.g. isotopes, geochemical tracers) with controlled chemical tracer (e.g., bromide, dyes) or colloidal tracer (e.g., carboxilated microspheres, tagged clay particles, microorganisms) applications. In the presented study we explore how understanding of sources and flow pathways of water derived from natural tracer studies can be improved and expanded in space and time by simultaneously introducing man-made, synthetic DNA-based microtracers. The microtracer used were composed of polylactic acid (PLA) microspheres into which short strands of synthetic DNA and paramagnetic iron oxide nanoparticles are incorporated. Tracer experiments using both natural tracers and the DNA-based microtracers were conducted in the sub-arctic, glacierized Tarfala (21.7 km2) catchment in northern Sweden. Isotopic hydrograph separations revealed that even though storm runoff was dominated by pre-event water the event water (i.e. rainfall) contributions to streamflow increased throughout the summer season as glacial snow cover decreased. This suggests that glaciers are a major source of the rainwater fraction in streamflow. Simultaneous injections of ten unique DNA-based microtracers confirmed this hypothesis and revealed that the transit time of water traveling from the glacier surface to the stream decreased fourfold over the summer season leading to instantaneous rainwater contributions during storm events. These results highlight that integrating simultaneous tracer injections (injecting tracers at multiple places at one time) with traditional tracer methods (sampling multiple times at one place) rather than using either approach in isolation can

  3. Modification of Rhodamine WT tracer tests procedure in activated sludge reactors

    Science.gov (United States)

    Knap, Marta; Balbierz, Piotr

    2017-11-01

    One of the tracers recommended for use in wastewater treatment plants and natural waters is Rhodamine WT, which is a fluorescent dye, allowing to work at low concentrations, but may be susceptible to sorption to activated sludge flocs and chemical quenching of fluorescence by dissolved water constituents. Additionally raw sewage may contain other natural materials or pollutants exhibiting limited fluorescent properties, which are responsible for background fluorescence interference. This paper presents the proposed modifications to the Rhodamine WT tracer tests procedure in activated sludge reactors, which allow to reduce problems with background fluorescence and tracer loss over time, developed on the basis of conducted laboratory and field experiments.

  4. Determination of the dispersion coefficient, in rivers through radioactive and fluorescent tracers

    International Nuclear Information System (INIS)

    Almeida Rosso, T.C. de.

    1986-03-01

    The purpose of this work was to determine experimentally the dispersion coefficient in natural streams through the aplication of radioactive and fluorescent tracers. The technique used to obtain the experimental data was the simmultaneous injection of the radioactive tracer Bromim - 82 and the fluorescent ones, Amidorodamine G. extra and Uranine. A comparison among these different tracers is shown as well as the performance of Uranine in a poluented stream in the presence of suspended sediments. The site chosen for the experiments was the Piabanha River, between Pedro do Rio and Areal, located at Rio de Janeiro state, in a nearly 20 Km strech. (Author) [pt

  5. Bacteriophages as surface and ground water tracers

    Directory of Open Access Journals (Sweden)

    P. Rossi

    1998-01-01

    Full Text Available Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra. In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  6. Tracer investigations of catalytic reactions of hydrocarbons

    International Nuclear Information System (INIS)

    Dermietzel, J.

    1984-12-01

    Tracer techniques with 14 C-labelled compounds were used to investigate the isomerization of C 8 -aromatics and reforming of light gasoline. The investigations aimed at determining the selectivity of newly developed catalysts and at elucidating the reaction mechanisms. The appropriate tracer methods are briefly discussed including their theoretical fundamentals

  7. Reactive Tracers for Characterizing Fractured Geothermal Reservoirs

    Science.gov (United States)

    Hawkins, Adam J.

    Multi-component tracer tests were conducted at a 10 x 10 m well field located in the Altona Flat Rocks of northern New York. Temperature advancement between two wells separated by 14 m was monitored throughout the well field during progressive heating of the reservoir over 6 d. Multiple approaches to predicting heat transport were applied to field data and compared to temperature rise recorded during reservoir heat-up. Tracer analysis incorporated both an analytical one-dimensional model and a two-dimensional numerical model for non-uniform fractures experiencing "flow-channeling." Modeling efforts demonstrated that estimating heat transfer surface area using a combined inert/adsorbing tracer (cesium-iodide) could provide accurate forecasting of premature thermal breakthrough. In addition, thermally degrading tracer tests were used to monitor inter-well temperature during progressive reservoir heating. Inert tracers alone were, in general, inadequate in forecasting thermal performance. In fact, moment analysis shows that, mathematically, thermal breakthrough is independent of parameters that primarily influence inert tracers. The most accurate prediction of thermal breakthrough using inert tracer alone was produced by treating hydrodynamic dispersion as a truly Fickian process with known and accurate mathematical models. Under this assumption, inert tracer data was matched by solving an inverse problem for non-uniform fracture aperture. Early arrival of the thermal front was predicted at the production, but was less accurate than using a combined inert/adsorbing tracer test. The spatial distribution of fluid flow paths in the plane of the fracture were identified using computational models, Fiber-Optic Distributed Temperature Sensing (FO-DTS), and Ground Penetrating Radar (GPR) imaging of saline tracer flow paths in the target fracture. Without exception, fluid flow was found to be concentrated in a roughly 1 m wide flow channel directly between the two wells. The

  8. Sensitivity analysis of tracer transport in variably saturated soils at USDA-ARS OPE3 field site

    Science.gov (United States)

    The objective of this study was to assess the effects of uncertainties in hydrologic and geochemical parameters on the results of simulations of the tracer transport in variably saturated soils at the USDA-ARS OPE3 field site. A tracer experiment with a pulse of KCL solution applied to an irrigatio...

  9. Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit

    Science.gov (United States)

    Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

    2017-06-01

    Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model

  10. Using molecular-scale tracers to investigate transport of agricultural pollutants in soil and water

    Science.gov (United States)

    Lloyd, C.; Michaelides, K.; Chadwick, D.; Dungait, J.; Evershed, R. P.

    2012-12-01

    We explore the use of molecular-scale tracers to investigate the transport of potential pollutants due to the application of slurry to soil. The molecular-scale approach allows us to separate the pollutants which are moved to water bodies through sediment-bound and dissolved transport pathways. Slurry is applied to agricultural land to as a soil-improver across a wide-range of topographic and climatic regimes, hence a set of experiments were designed to assess the effect of changing slope gradient and rainfall intensity on the transport of pollutants. The experiments were carried out using University of Bristol's TRACE (Test Rig for Advancing Connectivity Experiments) facility. The facility includes a dual axis soil slope (6 x 2.5 x 0.3 m3) and 6-nozzle rainfall simulator, which enables the manipulation of the slope to simulate different slope gradient and rainfall scenarios. Cattle slurry was applied to the top 1 metre strip of the experimental soil slope followed by four rainfall simulations, where the gradient (5° & 10°) and the rainfall intensity (60 & 120 mm hr-1) were co-varied. Leachate was sampled from different flow pathways (surface, subsurface and percolated) via multiple outlets on the slope throughout the experiments and soil cores were taken from the slope after each experiment. Novel tracers were used to trace the pollutants in both dissolved and sediment-bound forms. Fluorescence spectroscopy was used to trace dissolved slurry-derived material via water flow pathways, as the slurry was found to have a distinct signature compared with the soil. The fluorescence signatures of the leachates were compared with those of many organic compounds in order to characterise the origin of the signal. This allowed the assessment of the longevity of the signal in the environment to establish if it could be used as a robust long-term tracer of slurry material in water or if would be subject to transform processes through time. 5-βstanols, organic compounds

  11. Normal and anomalous diffusion of gravel tracer particles in rivers

    Science.gov (United States)

    Ganti, Vamsi; Meerschaert, Mark M.; Foufoula-Georgiou, Efi; Viparelli, Enrica; Parker, Gary

    2010-06-01

    One way to study the mechanism of gravel bed load transport is to seed the bed with marked gravel tracer particles within a chosen patch and to follow the pattern of migration and dispersal of particles from this patch. In this study, we invoke the probabilistic Exner equation for sediment conservation of bed gravel, formulated in terms of the difference between the rate of entrainment of gravel into motion and the rate of deposition from motion. Assuming an active layer formulation, stochasticity in particle motion is introduced by considering the step length (distance traveled by a particle once entrained until it is deposited) as a random variable. For step lengths with a relatively thin (e.g., exponential) tail, the above formulation leads to the standard advection-diffusion equation for tracer dispersal. However, the complexity of rivers, characterized by a broad distribution of particle sizes and extreme flood events, can give rise to a heavy-tailed distribution of step lengths. This consideration leads to an anomalous advection-diffusion equation involving fractional derivatives. By identifying the probabilistic Exner equation as a forward Kolmogorov equation for the location of a randomly selected tracer particle, a stochastic model describing the temporal evolution of the relative concentrations is developed. The normal and anomalous advection-diffusion equations are revealed as its long-time asymptotic solution. Sample numerical results illustrate the large differences that can arise in predicted tracer concentrations under the normal and anomalous diffusion models. They highlight the need for intensive data collection efforts to aid the selection of the appropriate model in real rivers.

  12. Using Tracer Technology to Characterize Contaminated Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Maresca, Joseph, W., Jr., Ph.D.; Bratton, Wesley, L., Ph.D., P.E.; Dickerson, Wilhelmina; Hales, Rochelle

    2005-12-30

    The Pipeline Characterization Using Tracers (PCUT) technique uses conservative and partitioning, reactive or other interactive tracers to remotely determine the amount of contaminant within a run of piping or ductwork. The PCUT system was motivated by a method that has been successfully used to characterize subsurface soil contaminants and is similar in operation to that of a gas chromatography column. By injecting a ?slug? of both conservative and partitioning tracers at one end (or section) of the piping and measuring the time history of the concentration of the tracers at the other end (or another section) of the pipe, the presence, location, and amount of contaminant within the pipe or duct can be determined. The tracers are transported along the pipe or duct by a gas flow field, typically air or nitrogen, which has a velocity that is slow enough so that the partitioning tracer has time to interact with the contaminant before the tracer slug completely passes over the contaminate region. PCUT not only identifies the presence of contamination, it also can locate the contamination along the pipeline and quantify the amount of residual. PCUT can be used in support of deactivation and decommissioning (D&D) of piping and ducts that may have been contaminated with hazardous chemicals such as chlorinated solvents, petroleum products, radioactive materials, or heavy metals, such as mercury.

  13. Tracer Equivalent Latitude: A Diagnostic Tool for Isentropic Transport Studies.

    Science.gov (United States)

    Allen, Douglas R.; Nakamura, Noboru

    2003-01-01

    Area equivalent latitude based on potential vorticity (PV) is a widely used diagnostic for isentropic transport in the stratosphere and upper troposphere. Here, an alternate method for calculating equivalent latitude is explored, namely, a numerical synthesis of a PV-like tracer from a long-term integration of the advection-diffusion equation on isentropic surfaces. It is found that the tracer equivalent latitude (TrEL) behaves much like the traditional PV equivalent latitude (PVEL) despite the simplified governing physics; this is evidenced by examining the kinematics of the Arctic lower stratospheric vortex. Yet in some cases TrEL performs markedly better as a coordinate for long-lived trace species such as ozone. These instances include analysis of lower stratospheric ozone during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign and three-dimensional reconstruction of total column ozone during November-December 1999 from fitted ozone-equivalent latitude relationship. It is argued that the improvement is due to the tracer being free from the diagnostic errors and certain diabatic processes that affect PV. The sensitivity of TrEL to spatial and temporal resolution, advection scheme, and driving winds is also examined.

  14. Studies of Tracer Dispersion and Fluid Flow in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Rage, T.

    1996-12-31

    This doctoral thesis explores the connection between the topology of a porous medium and its macroscopic transport properties and is based on computerized simulation. In porous media, both diffusion and convection contribute to the dispersion of a tracer and their combined effect is emphasized. The governing equations are solved numerically, using finite differences and Monte Carlo technique. The influence of finite Reynolds number on the outcome of echo-experiments is discussed. Comparing experiments and simulations it is found that nonlinear inertial forces lead to a visible deformation of a returned tracer at surprisingly small Reynolds numbers. In a study of tracer dispersion and fluid flow in periodic arrays of discs it is demonstrated that the mechanisms of mechanical dispersion in periodic media and in natural (non-periodic) porous media are essentially different. Measurements of the percolation probability distribution of a sandstone sample is presented. Local porosity theory predicts that this simple geometric function of a porous medium is of dominant importance for its macroscopic transport properties. It is demonstrated that many aspects of transport through fractures can be studied by using simple but realistic models and readily available computer resources. An example may be the transport of hydrocarbon fluids from the source rock to a reservoir. 165 refs., 44 figs., 1 table

  15. Tracers vs. trajectories in a coastal region

    Science.gov (United States)

    Engqvist, A.; Döös, K.

    2008-12-01

    Two different methods of estimating the water exchange through a Baltic coastal region have been used, consisting of particle trajectories and passive tracers. Water is traced from and to a small discharge region near the coast. The discharge material in this region is treated as zero dimensional particles or tracers with neutral buoyancy. The real discharge material could be a leakage of radio-nuclides through the sea floor from an underground repository of nuclear waste. Water exchange rates between the discharge region and the model domain are estimated using both forward and backward trajectories as well as passive tracers. The Lagrangian trajectories can account for the time evolution of the water exchange while the tracers give one average age per model grid box. Water exchange times such as residence time, age and transient times have been calculated with trajectories but only the average age (AvA) for tracers. The trajectory calculations provide a more detailed time evolution than the tracers. On the other hand the tracers are integrated "on-line" simultaneously in the sea circulation model with the same time step while the Lagrangian trajectories are integrated "off-line" from the stored model velocities with its inherent temporal resolution, presently one hour. The sub-grid turbulence is parameterised as a Laplacian diffusion for the passive tracers and with an extra stochastic velocity for trajectories. The importance of the parameterised sub-grid turbulence for the trajectories is estimated to give an extra diffusion of the same order as the Laplacian diffusion by comparing the Lagrangian dispersions with and without parameterisation. The results of the different methods are similar but depend on the chosen diffusivity coefficient with a slightly higher correlation between trajectories and tracers when integrated with a lower diffusivity coefficient.

  16. The 1996 thaw as a {sup 18}O tracer experiment at the lysimeter plant in Wagna; Die Schneeschmelze 1996 als {sup 18}O-Tracerversuch an der Lysimeteranlage in Wagna

    Energy Technology Data Exchange (ETDEWEB)

    Fank, J.; Zojer, H. [Forschungsgesellschaft Joanneum, Graz (Austria). Inst. fuer Geothermie und Hydrogeologie; Stichler, W. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    In the year 1991 a research site was set up in Wagna in the western Leibnitz Field (Styria) which permits an examination of seepage water movement and of material transport as a function of the permeability of the uppermost soil layers and the underlying more coarsly clastic sediments under locale-specific natural management systems. Research at this site is largely based on hydrochemical and isotope-hydrological analysis. The {sup 18}O isotope is an ideal natural tracer of water movement. Infiltration water from the thaw following a snowy winter was displaced downward into the unsaturated zone as a result of a major precipitation event of 85.5 mm from April 2 to 5, 1996. This displacement is evident in the {sup 18}O concentrations of the seepage water at various measuring depths. The displacement is associated with recharge events, thaw processes tending to produce dispersive flows and precipitation events leading to ``piston flow effects. Winter precipitation water reaches a depth of 60 to 70 cm by mid-April. The attenuated {sup 18}O concentration reveals the predominant flow characteristics in the different compartments of the unsaturated zone (finely clastic soils, gravels, and sands). [Deutsch] Im Jahre 1991 wurde in Wagna, im westlichen Leibnitzer Feld (Steiermark), eine Forschungsstation errichtet, die es erlaubt, unter ortsueblichen, natuerlichen Bewirtschaftungssystemen die Sickerwasserbewegung und den Transport von Stoffen in Abhaengigkeit von der Durchlaessigkeit der obersten Bodenschichten und der darunter folgenden groeberklastischen Sedimente vor allem auf Grundlage der hydrochemischen und isotopenhydrologischen Analytik zu untesuchen. Die Verwendung des {sup 18}O-Isotops als natuerlicher Tracer repraesentiert in idealer Weise die Bewegung des Wassers. Infiltrationswasser aus der Schneeschmelze nach einem schneereichen Winter wurde durch ein starkes Niederschlagsereignis von 85.6 mm zwischen 2. und 5. April 1996 in der ungesaettigten Zone

  17. Tracer Methods for Characterizing Fracture Creation in Engineered Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter [Energy & Geoscience Institute at the University of Utah, Salt Lake City, UT (United States); Harris, Joel [Univ. of Utah, Salt Lake City, UT (United States)

    2014-05-08

    The aim of this proposal is to develop, through novel high-temperature-tracing approaches, three technologies for characterizing fracture creation within Engineered Geothermal Systems (EGS). The objective of a first task is to identify, develop and demonstrate adsorbing tracers for characterizing interwell reservoir-rock surface areas and fracture spacing. The objective of a second task is to develop and demonstrate a methodology for measuring fracture surface areas adjacent to single wells. The objective of a third task is to design, fabricate and test an instrument that makes use of tracers for measuring fluid flow between newly created fractures and wellbores. In one method of deployment, it will be used to identify qualitatively which fractures were activated during a hydraulic stimulation experiment. In a second method of deployment, it will serve to measure quantitatively the rate of fluid flowing from one or more activated fracture during a production test following a hydraulic stimulation.

  18. In-situ fracture mapping using geotomography and brine tracers

    International Nuclear Information System (INIS)

    Deadrick, F.J.; Ramirez, A.L.; Lytle, R.J.

    1981-01-01

    The Lawrence Livermore National Laboratory is currently assessing the capabilities of high resolution geophysical methods to characterize geologic sites for the disposal of high level nuclear waste. A successful experiment has recently been performed in which salt water tracers and high frequency electromagnetic waves were utilized to map rock mass fracture zones in-situ. Multiple cross-borehole EM transmissions were used to generate a tomographic image of the fractured rock region between two boreholes. The tomographs obtained correlate well with conventional wireline geophysical logs which can be used to infer the location of fractured zones in the rock mass. This indirect data suggests that the geotomography and brine tracer technique may have merit in mapping fractured zones between boreholes

  19. Contributions to hydrological tracer methods and their application

    International Nuclear Information System (INIS)

    1982-04-01

    The activities of the Institut fuer Radiohydrometrie of the GSF are mainly devoted to the field of environmental research studying the quality, use and protection from pollution of drinking water which has become scarce in many parts of the world. The knowledge and experience of a variety of scientific disciplines are combined to the common task of developing new tracer methods and selecting suitable hydrogeological methods to allow quantitative studies of the hydrological cycle, from rainfall to surface or sub-surface run-off. The tracers used in these studies are for the most part stable, natural radioisotopes occurring in the hydrological cycle, as well as fluorescent dyes or radionuclides for water labelling. The contributions collected in this volume are grouped according to the above outline of tasks and present a survey of current methods and measurements, illustrating their efficiency in solving hydrological problems. (orig./RW) [de

  20. Comparison of thermal, salt and dye tracing to estimate shallow flow velocities: Novel triple-tracer approach

    Science.gov (United States)

    Abrantes, João R. C. B.; Moruzzi, Rodrigo B.; Silveira, Alexandre; de Lima, João L. M. P.

    2018-02-01

    The accurate measurement of shallow flow velocities is crucial to understand and model the dynamics of sediment and pollutant transport by overland flow. In this study, a novel triple-tracer approach was used to re-evaluate and compare the traditional and well established dye and salt tracer techniques with the more recent thermal tracer technique in estimating shallow flow velocities. For this purpose a triple tracer (i.e. dyed-salted-heated water) was used. Optical and infrared video cameras and an electrical conductivity sensor were used to detect the tracers in the flow. Leading edge and centroid velocities of the tracers were measured and the correction factors used to determine the actual mean flow velocities from tracer measured velocities were compared and investigated. Experiments were carried out for different flow discharges (32-1813 ml s-1) on smooth acrylic, sand, stones and synthetic grass bed surfaces with 0.8, 4.4 and 13.2% slopes. The results showed that thermal tracers can be used to estimate shallow flow velocities, since the three techniques yielded very similar results without significant differences between them. The main advantages of the thermal tracer were that the movement of the tracer along the measuring section was more easily visible than it was in the real image videos and that it was possible to measure space-averaged flow velocities instead of only one velocity value, with the salt tracer. The correction factors used to determine the actual mean velocity of overland flow varied directly with Reynolds and Froude numbers, flow velocity and slope and inversely with flow depth and bed roughness. In shallow flows, velocity estimation using tracers entails considerable uncertainty and caution must be taken with these measurements, especially in field studies where these variables vary appreciably in space and time.

  1. Steady-state tracer dynamics in a lattice-automaton model of bioturbation

    NARCIS (Netherlands)

    Reed, D.C.; Huang, K.; Boudreau, B.P.; Meysman, F.J.R.

    2006-01-01

    The intensity of biogenic sediment mixing is often expressed as a “biodiffusion coefficient” (Db), quantified by fitting a diffusive model of bioturbation to vertical profiles of particle-bound radioisotopes. The biodiffusion coefficient often exhibits a dependence on tracer half-life: short-lived

  2. Intensity-modulated radiation treatment for head-and-neck squamous cell carcinoma-the University of Iowa experience

    International Nuclear Information System (INIS)

    Yao Min; Dornfeld, Kenneth J.; Buatti, John M.; Skwarchuk, Mark; Tan Huaming; Nguyen, Thanh; Wacha, Judith C.; Bayouth, John E.; Funk, Gerry F.; Smith, Russell B.; Graham, Scott M.; Chang, Kristi; Hoffman, Henry T.

    2005-01-01

    Purpose: To review the University of Iowa experience with intensity-modulated radiotherapy (IMRT) in the treatment of head-and-neck squamous cell carcinoma. Methods and Materials: From October 1999 to April 2004, 151 patients with head-and-neck squamous cell carcinoma were treated with IMRT for curative intent. One patient was lost to follow-up 2 months after treatment and therefore excluded from analysis. Of the remaining 150 patients, 99 were treated with definitive IMRT, and 51 received postoperative IMRT. Sites included were nasopharynx, 5; oropharynx, 56; larynx, 33; oral cavity, 29; hypopharynx, 8; nasal cavity/paranasal sinus, 8; and unknown primary, 11. None of the patients treated with postoperative IMRT received chemotherapy. Of 99 patients who had definitive IMRT, 68 patients received concurrent cisplatin-based chemotherapy. One patient received induction cisplatin-based chemotherapy, but no concurrent chemotherapy was given. Three clinical target volumes (CTV1, CTV2, and CTV3) were defined. The prescribed doses to CTV1, CTV2, and CTV3 in the definitive cohort were 70-74 Gy, 60 Gy, and 54 Gy, respectively. For high-risk postoperative IMRT, the prescribed doses to CTV1, CTV2, and CTV3 were 64-66 Gy, 60 Gy, and 54 Gy, respectively. For intermediate-risk postoperative IMRT, the prescribed doses to CTV1, CTV2, and CTV3 were 60 Gy, 60 Gy, and 54 Gy. Results: The median follow-up was 18 months (range, 2-60 months). All living patients were followed for at least 6 months. There were 11 local-regional failures: 7 local failures, 3 regional failures, and 1 failure both in the primary tumor and regional lymph node. There were 16 patients who failed distantly, either with distant metastasis or new lung primaries. The 2-year overall survival, local progression-free survival, locoregional progression-free survival, and distant disease-free survival rates were 85%, 94%, 92%, and 87%, respectively. The median time from treatment completion to local-regional recurrence

  3. Taiwanese Parents' Experience of Making a “Do Not Resuscitate” Decision for Their Child in Pediatric Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Shu-Mei Liu, RN, MN

    2014-03-01

    Conclusion: Open family visiting hours plus staff sensitivity and communication skills training are needed. To help parents with this difficult signing process, nurses and other professionals in the pediatric intensive care unit need education on initiating the conversation, guiding the parents in expressing their fears, and providing continuing support to parents and children throughout the child's end of life process.

  4. First experiences with model based iterative reconstructions influence on quantitative plaque volume and intensity measurements in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Kitslaar, Pieter H.; Broersen, Alexander

    2017-01-01

    : Three patients had three independent dose reduced CCTA performed and reconstructed with 30% ASIR (CTDIvol at 6.7 mGy), 60% ASIR (CTDIvol 4.3 mGy) and Veo (CTDIvol at 1.9 mGy). Coronary plaque analysis was performed for each measured CCTA volumes, plaque burden and intensities. Results: Plaque volume...

  5. The accurate particle tracer code

    Science.gov (United States)

    Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi; Yao, Yicun

    2017-11-01

    The Accurate Particle Tracer (APT) code is designed for systematic large-scale applications of geometric algorithms for particle dynamical simulations. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and nonlinear problems. To provide a flexible and convenient I/O interface, the libraries of Lua and Hdf5 are used. Following a three-step procedure, users can efficiently extend the libraries of electromagnetic configurations, external non-electromagnetic forces, particle pushers, and initialization approaches by use of the extendible module. APT has been used in simulations of key physical problems, such as runaway electrons in tokamaks and energetic particles in Van Allen belt. As an important realization, the APT-SW version has been successfully distributed on the world's fastest computer, the Sunway TaihuLight supercomputer, by supporting master-slave architecture of Sunway many-core processors. Based on large-scale simulations of a runaway beam under parameters of the ITER tokamak, it is revealed that the magnetic ripple field can disperse the pitch-angle distribution significantly and improve the confinement of energetic runaway beam on the same time.

  6. RFID tags as a direct tracer for water and sediment dynamics

    Science.gov (United States)

    Sommerer, Erik; Plate, Simon; Güntner, Andreas

    2014-05-01

    RFID (Radio Frequency IDentification) is a wireless automatic identification system to track objects with widespread application in industrial operations, but also selected applications in ecological research (animal tracking) and for hydro-sedimentological studies (sediment transport with RFID tags embedded in bedload material). In this study, for the first time, we test and apply RFID tags as a direct tracer to track water pathways, erosion patterns and sediment transport on the surface at the hillslope and headwater scale. The RFID system used here consists of tags with a size of 12 x 2 mm and a combination of mobile and stationary antennas. The transport pathways and velocities of the RFID tags can be individually assessed due to their unique identification numbers. The study area is a badland of easily erodible marls and carbonates located in the Villacarli catchment (42 km²) in the Central Spanish Pyrenees. The badlands have been identified as one of the main sediment sources for siltation of the downstream Barasona Reservoir. More than 700 tags were placed in different terrain units using three experimental setups, including lab experiments: (i) intensive feasibility tests ranging from laboratory flume experiments to tracer studies under natural channel and slope conditions to compare the transport of RFID tags relative to colored particles of the natural sediment; (ii) several transects across the badland to investigate sediment transfer characteristics on different morphological units (i.e. channel, rills, slopes); (iii) a raster of 99 RFID tags covering a slope flank with vegetated and unvegetated parts to reveal the influence of vegetation to erosion and transport processes. The detection of transported tags was carried out with a mobile antenna system to map the spatial distribution of tags after selected rainfall events and with two stationary antennas in channel cross-sections for time-continuous observation of tag passage. From the observations, we

  7. Assessment of the Relationship between Recurrent High-risk Pregnancy and Mothers’ Previous Experience of Having an Infant Admitted to a Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Sedigheh Hantoosh Zadeh

    2015-01-01

    Full Text Available Background & aim:  High-risk pregnancies increase the risk of Intensive Care Unit (ICU and Neonatal Intensive Care Unit (NICU admission in mothers and their newborns. In this study, we aimed to identify the association between the recurrence of high-risk pregnancy and mothers’ previous experience of having an infant admitted to NICU. Methods:We performed a cohort, retrospective study to compare subsequent pregnancy outcomes among 232 control subjects and 200 female cases with a previous experience of having a newborn requiring NICU admission due to intrauterine growth retardation, preeclampsia, preterm birth, premature rupture of membranes, and asphyxia. The information about the prevalence of subsequent high-risk pregnancies was gathered via phone calls. Results: As the results indicated, heparin, progesterone, and aspirin were more frequently administered in the case group during subsequent pregnancies, compared to the control group (P

  8. "What happens behind the curtains?" An exploration of ICU nurses' experiences of post mortem care on patients who have died in intensive care.

    Science.gov (United States)

    de Swardt, Carien; Fouché, Nicola

    2017-12-01

    The aim of this study was to explore the experiences of intensive care nurses performing post mortem care on patients who had died in an intensive care unit at a private hospital in Cape Town. The study further sets out to identify educational needs and to offer recommendations that may address these needs for this sample of nurses. A qualitative research design using a descriptive method was used to explore the experiences of a purposive heterogeneous sample of six nurses who were working in an intensive care unit in a private hospital in Cape Town. A semi-structured interview which was audio-taped and transcribed verbatim was employed to collect data. Colaizzi's (1978) seven step inductive method was used to formulate naïve themes. Following participant feedback, three main themes emerged: care of the dead body, detachment and thanatophobia. Safeguarding the integrity and physical appearance of the dead body was the major finding and of the utmost priority for the participants in this study. Regardless of how the nurses felt about death, providing professional and quality care to the dead body and the family was seen as significantly important. The nurses, whilst performing post mortem care, experienced detachment from various relationships. This comprised of the nurse detaching him/herself professionally and emotionally from the dead patient, the family and him/herself from the death experience. This 'unspoken' experience of thanatophobia became apparent when the nurses were confronted by the reality of their own deaths. In a technological society, where answers to many questions can be pursued through science, understanding the experience of death, as opposed to dying, may be logically incomprehensible. Death remains one of the most traumatic events experienced by the patient and their family, and in some instances nurses themselves. The study has drawn attention to the nurses' experiences and in doing so; the emotional and educational needs have been

  9. A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment

    International Nuclear Information System (INIS)

    Gribble, R.

    1993-06-01

    A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described

  10. Direct Observation of Heavy-Tailed Storage Times of Bed Load Tracer Particles Causing Anomalous Superdiffusion

    Science.gov (United States)

    Bradley, D. Nathan

    2017-12-01

    A consensus has formed that the step length distribution of fluvial bed load is thin tailed and that the observed anomalous superdiffusion of bed load tracer particles must arise from heavy-tailed resting times. However, heavy-tailed resting times have never been directly observed in the field over multiple floods. Using 9 years of data from a large bed load tracer experiment, I show that the spatial variance of the tracer plume scales faster than linearly with integrated excess stream power, indicating anomalous superdiffusion. The superdiffusion is caused by a heavy-tailed distribution of observed storage times that is fit with a truncated Pareto distribution with a tail parameter that is predicted by anomalous diffusion theory. The heavy-tailed distribution of storage times causes the tracer virtual velocity to slow over time, indicated by a sublinear increase in the mean displacement that is predicted by the storage time distribution tail parameter.

  11. Graphical Analysis of PET Data Applied to Reversible and Irreversible Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Jean

    1999-11-18

    Graphical analysis refers to the transformation of multiple time measurements of plasma and tissue uptake data into a linear plot, the slope of which is related to the number of available tracer binding sites. This type of analysis allows easy comparisons among experiments. No particular model structure is assumed, however it is assumed that the tracer is given by bolus injection and that both tissue uptake and the plasma concentration of unchanged tracer are monitored following tracer injection. The requirement of plasma measurements can be eliminated in some cases when a reference region is available. There are two categories of graphical methods which apply to two general types of ligands--those which bind reversibly during the scanning procedure and those which are irreversible or trapped during the time of the scanning procedure.

  12. Suitable activated stable nuclide tracer technique and its applications in biology and medicine

    International Nuclear Information System (INIS)

    Zhang Weicheng

    1989-01-01

    Stable isotopes as tracers in biology and medicine have been more extensively used. Mass spectrometry has been a classic technique in the analysis of stable isotopes because it is very sensitive and precise. Activation analysis has recently been introduced as an analytical tool. Its fast speed and simplicity is a great advantage for handling large batches of samples in isotopic tracer experiments. The combination of enriched stable isotope tracer studies and activation analysis techniques has become an ideal and reliable technique, especially in the fields of biology and medicine. This paper presents a survey of the fundamental principle, the character and the applications in biology and medicine for the suitable activated stable isotope tracer techniques

  13. A tracer diffusion model derived from microstructure

    International Nuclear Information System (INIS)

    Lehikoinen, Jarmo; Muurinen, Arto; Olin, Markus

    2012-01-01

    Document available in extended abstract form only. Full text of publication follows: Numerous attempts have been made to explain the tracer diffusion of various solutes in compacted clays. These attempts have commonly suffered from an inability to describe the diffusion of uncharged and charged solutes with a single unified model. Here, an internally consistent approach to describing the diffusion of solutes in a heterogeneous porous medium, such as compacted bentonite, in terms of its microstructure is presented. The microstructure is taken to be represented by a succession of unit cells, which consist of two consecutive regions (Do, 1996). In the first region, the diffusion is viewed to occur in two parallel paths: one through microcrystalline units (micropores) and the other through meso-pores between the microcrystalline units. Solutes exiting these two paths are then joined together to continue diffusing through the second, disordered, region, connecting the two adjacent microcrystalline units. Adsorption (incl. co-ion exclusion) is thought to occur in the micropores, whereas meso-pores and the disordered region accommodate free species alone. Co-ions are also assumed to experience transfer resistance into and out of the micropores, which is characterized in the model by a transmission coefficient. Although the model is not new per se, its application to compacted clays has never been attempted before. It is shown that in the limit of strong adsorption, the effective diffusivity is limited from above only by the microstructural parameters of the model porous medium. As intuitive and logical as this result may appear, it has not been proven before. In the limit of vanishing disordered region, the effective diffusivity is no longer explicitly constrained by any of the model parameters. The tortuosity of the diffusion path, i.e. the quotient of the actual diffusion path length in the porous-medium coordinates and the characteristic length of the laboratory frame

  14. Optimization of 13C isotopic tracers for metabolic flux analysis in mammalian cells.

    Science.gov (United States)

    Walther, Jason L; Metallo, Christian M; Zhang, Jie; Stephanopoulos, Gregory

    2012-03-01

    Mammalian cells consume and metabolize various substrates from their surroundings for energy generation and biomass synthesis. Glucose and glutamine, in particular, are the primary carbon sources for proliferating cancer cells. While this combination of substrates generates static labeling patterns for use in (13)C metabolic flux analysis (MFA), the inability of single tracers to effectively label all pathways poses an obstacle for comprehensive flux determination within a given experiment. To address this issue we applied a genetic algorithm to optimize mixtures of (13)C-labeled glucose and glutamine for use in MFA. We identified tracer combinations that minimized confidence intervals in an experimentally determined flux network describing central carbon metabolism in tumor cells. Additional simulations were used to determine the robustness of the [1,2-(13)C(2)]glucose/[U-(13)C(5)]glutamine tracer combination with respect to perturbations in the network. Finally, we experimentally validated the improved performance of this tracer set relative to glucose tracers alone in a cancer cell line. This versatile method allows researchers to determine the optimal tracer combination to use for a specific metabolic network, and our findings applied to cancer cells significantly enhance the ability of MFA experiments to precisely quantify fluxes in higher organisms. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Warren, B.

    2012-12-01

    We present results from the grant entitled, Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions. The research significantly advanced the understanding of basic high-energy density science (HEDS) on ultra intense laser and particle beam plasma interactions. This advancement in understanding was then used to to aid in the quest to make 1 GeV to 500 GeV plasma based accelerator stages. The work blended basic research with three-dimensions fully nonlinear and fully kinetic simulations including full-scale modeling of ongoing or planned experiments. The primary tool was three-dimensional particle-in-cell simulations. The simulations provided a test bed for theoretical ideas and models as well as a method to guide experiments. The research also included careful benchmarking of codes against experiment. High-fidelity full-scale modeling provided a means to extrapolate parameters into regimes that were not accessible to current or near term experiments, thereby allowing concepts to be tested with confidence before tens to hundreds of millions of dollars were spent building facilities. The research allowed the development of a hierarchy of PIC codes and diagnostics that is one of the most advanced in the world.

  16. Effects of experience on the dimensions of intensity, direction and frequency of the competitive anxiety and self-confidence: A study in athletes of individual and team sports

    Directory of Open Access Journals (Sweden)

    Marcos Gimenes Fernandes

    2014-06-01

    Full Text Available The present study had the following objectives: i to examine the inter-scale correlations between the three dimensions of responses (intensity, direction and frequency of the CSAI-2R and its relationship with competitive experience, and ii evaluate the effect of competitive experience anxiety (cognitive and somatic and self-confidence in the total sample and for different types of modalities (individual vs. team. The sample consisted of 267 athletes (196 male and 71 female, of different sports, aged between 18 and 40 years (M = 24.30, SD = 5.62. Athletes completed the Brazilian version of the CSAI-2, which included the addition of the dimensions of direction and frequency response. Spearman test and Manova were used for the data analysis. Overall, it was found that the competitive experience has a high multivariate and significant effect on the dimensions of competitive anxiety. Both individual and team athletes with low competitive experience showed a trend to report lower levels of self-confidence intensity, compared to counterparts with high competitive experience. These results were discussed in view of the theoretic framework and practical implications planning Sport Psychology intervention programs in local athletes with different backgrounds.

  17. Radioisotope tracers in industrial flow studies

    International Nuclear Information System (INIS)

    Easey, J.F.

    1987-01-01

    The scope of radioisotope tracer work carried out by ANSTO has involved most sectors of Australian industry including iron and steel coal, chemical, petrochemical, natural gas, metallurgical, mineral, power generation, liquified air plant, as well as port authorities, water and sewerage instrumentalities, and environmental agencies. A major class of such studies concerns itself with flow and wear studies involving industrial equipment. Some examples are discussed which illustrate the utility of radioisotope tracer techniques in these applications

  18. [Experience with a selenium-containing biological active supplement used in children with pneumonias in an intensive care unit].

    Science.gov (United States)

    Uglitskikh, A K; Tsokova, N B; Gmoshinskiĭ, I V; Mazo, V K; Kon', I Ia; Ostreĭkov, I F

    2006-01-01

    The efficacy of the biologically active additive (BAA) "Spirulin-Sochi-Selen" was evaluated in 45 children aged 3 to 15 years who had acute pneumonia treated in the intensive care unit for infected patients of the Tushino children's city hospital, Moscow. The levels of selenium were determined by the Alfthan microfluorimetric technique (1984). The time course of clinical, laboratory, functional, and X-ray changes was determined. A control group comprised 20 children taking no selenium-containing foods or biologically active additives. The findings suggest that the BAA "Spirulin-Sochi-Selen" is effective as part of therapy for acute pneumonia in children treated in an intensive care unit. There were no signs of selenium deficiency in any case despite the baseline reduction in the average serum levels in both groups.

  19. Improving Marine Ecosystem Models with Biochemical Tracers

    Science.gov (United States)

    Pethybridge, Heidi R.; Choy, C. Anela; Polovina, Jeffrey J.; Fulton, Elizabeth A.

    2018-01-01

    Empirical data on food web dynamics and predator-prey interactions underpin ecosystem models, which are increasingly used to support strategic management of marine resources. These data have traditionally derived from stomach content analysis, but new and complementary forms of ecological data are increasingly available from biochemical tracer techniques. Extensive opportunities exist to improve the empirical robustness of ecosystem models through the incorporation of biochemical tracer data and derived indices, an area that is rapidly expanding because of advances in analytical developments and sophisticated statistical techniques. Here, we explore the trophic information required by ecosystem model frameworks (species, individual, and size based) and match them to the most commonly used biochemical tracers (bulk tissue and compound-specific stable isotopes, fatty acids, and trace elements). Key quantitative parameters derived from biochemical tracers include estimates of diet composition, niche width, and trophic position. Biochemical tracers also provide powerful insight into the spatial and temporal variability of food web structure and the characterization of dominant basal and microbial food web groups. A major challenge in incorporating biochemical tracer data into ecosystem models is scale and data type mismatches, which can be overcome with greater knowledge exchange and numerical approaches that transform, integrate, and visualize data.

  20. Trends and open questions in industrial tracer applications

    International Nuclear Information System (INIS)

    Guizerix, J.

    1986-01-01

    Proceeding from the distinction between methodology, technology, and nuclear technology an outline of the tracer technology is given in order to define the matter of the subject. The following items are discussed in detail: trends in tracer theory, tracer technolgy, tracer applications, and open questions

  1. Food resources of stream macroinvertebrates determined by natural-abundance stable C and N isotopes and a 15N tracer addition

    Science.gov (United States)

    Patrick J. Mulholland; Jennifer L. Tank; Diane M. Sanzone; Wilfrid M. Wollheim; Bruce J. Peterson; Jackson R. Webster; Judy L. Meyer

    2000-01-01

    Trophic relationships were examined using natural-abundance 13C and 15N analyses and a 15N-tracer addition experiment in Walker Branch, a 1st-order forested stream in eastern Tennessee. In the 15N-tracer addition experiment, we added 15NH4...

  2. Parents' experience of undertaking an intensive cognitive orientation to daily occupational performance (CO-OP) group for children with cerebral palsy.

    Science.gov (United States)

    Jackman, Michelle; Novak, Iona; Lannin, Natasha; Froude, Elspeth

    2017-05-01

    The purpose of this study was to explore the experience of parents of children with cerebral palsy (CP) who participated in an intensive cognitive orientation to daily occupational performance (CO-OP) group program addressing child chosen goals. Participants were six parents of children with CP who participated in a CO-OP upper limb task-specific training program. Parents participated in semi-structured interviews conducted via phone. A grounded theory approach was used. Interviews were transcribed verbatim and coded to identify categories and overarching themes of the parent experience of CO-OP. The theory of CO-OP for children with CP was one of offering a unique and motivating learning experience for both the child and the parent, differing from other therapeutic approaches that families had previously been involved in. Five categories were identified: the unique benefits of CO-OP; the importance of intensity; the child's motivation; challenging the parent role; and the benefits and challenges of therapy within a group context. Parents felt that CO-OP was a worthwhile intervention that leads to achievement of goals involving upper limb function and had the capacity to be transferred to future goals. Intensity of therapy and a child's motivation were identified as important factors in improvements. Further studies using quantitative research methods are warranted to investigate the benefits of CO-OP for children with neurological conditions. Implications for rehabilitation The cognitive orientation to daily occupational performance (CO-OP) is a promising upper limb cognitive motor training intervention for children with cerebral palsy. In a small sample, parents perceived that CO-OP leads to achievement of upper limb goals. Intensity of therapy, the child's motivation and the parents' ability to "step-back" were identified as important to the success of CO-OP.

  3. Quantifying postfire aeolian sediment transport using rare earth element tracers

    Science.gov (United States)

    Dukes, David; Gonzales, Howell B.; Ravi, Sujith; Grandstaff, David E.; Van Pelt, R. Scott; Li, Junran; Wang, Guan; Sankey, Joel B.

    2018-01-01

    Grasslands, which provide fundamental ecosystem services in many arid and semiarid regions of the world, are undergoing rapid increases in fire activity and are highly susceptible to postfire-accelerated soil erosion by wind. A quantitative assessment of physical processes that integrates fire-wind erosion feedbacks is therefore needed relative to vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique—the use of multiple rare earth elements (REE)—to quantify soil transport by wind and to identify sources and sinks of wind-blown sediments in both burned and unburned shrub-grass transition zone in the Chihuahuan Desert, NM, USA. Results indicate that the horizontal mass flux of wind-borne sediment increased approximately threefold following the fire. The REE tracer analysis of wind-borne sediments shows that the source of the horizontal mass flux in the unburned site was derived from bare microsites (88.5%), while in the burned site it was primarily sourced from shrub (42.3%) and bare (39.1%) microsites. Vegetated microsites which were predominantly sinks of aeolian sediments in the unburned areas became sediment sources following the fire. The burned areas showed a spatial homogenization of sediment tracers, highlighting a potential negative feedback on landscape heterogeneity induced by shrub encroachment into grasslands. Though fires are known to increase aeolian sediment transport, accompanying changes in the sources and sinks of wind-borne sediments may influence biogeochemical cycling and land degradation dynamics. Furthermore, our experiment demonstrated that REEs can be used as reliable tracers for field-scale aeolian studies.

  4. Analysis of tracer and thermal transients during reinjection

    Energy Technology Data Exchange (ETDEWEB)

    Kocabas, I.

    1989-10-01

    This work studied tracer and thermal transients during reinjection in geothermal reserviors and developed a new technique which combines the results from interwell tracer tests and thermal injection-backflow tests to estimate the thermal breakthrough times. Tracer tests are essential to determine the degree of connectivity between the injection wells and the producing wells. To analyze the tracer return profiles quantitatively, we employed three mathematical models namely, the convection-dispersion (CD) model, matrix diffusion (MD) model, and the Avodnin (AD) model, which were developed to study tracer and heat transport in a single vertical fracture. We considered three types of tracer tests namely, interwell tracer tests without recirculation, interwell tracer tests with recirculation, and injection-backflow tracer tests. To estimate the model parameters, we used a nonlinear regression program to match tracer return profiles to the solutions.

  5. Regularized image reconstruction algorithms for dual-isotope myocardial perfusion SPECT (MPS) imaging using a cross-tracer prior.

    Science.gov (United States)

    He, Xin; Cheng, Lishui; Fessler, Jeffrey A; Frey, Eric C

    2011-06-01

    In simultaneous dual-isotope myocardial perfusion SPECT (MPS) imaging, data are simultaneously acquired to determine the distributions of two radioactive isotopes. The goal of this work was to develop penalized maximum likelihood (PML) algorithms for a novel cross-tracer prior that exploits the fact that the two images reconstructed from simultaneous dual-isotope MPS projection data are perfectly registered in space. We first formulated the simultaneous dual-isotope MPS reconstruction problem as a joint estimation problem. A cross-tracer prior that couples voxel values on both images was then proposed. We developed an iterative algorithm to reconstruct the MPS images that converges to the maximum a posteriori solution for this prior based on separable surrogate functions. To accelerate the convergence, we developed a fast algorithm for the cross-tracer prior based on the complete data OS-EM (COSEM) framework. The proposed algorithm was compared qualitatively and quantitatively to a single-tracer version of the prior that did not include the cross-tracer term. Quantitative evaluations included comparisons of mean and standard deviation images as well as assessment of image fidelity using the mean square error. We also evaluated the cross tracer prior using a three-class observer study with respect to the three-class MPS diagnostic task, i.e., classifying patients as having either no defect, reversible defect, or fixed defects. For this study, a comparison with conventional ordered subsets-expectation maximization (OS-EM) reconstruction with postfiltering was performed. The comparisons to the single-tracer prior demonstrated similar resolution for areas of the image with large intensity changes and reduced noise in uniform regions. The cross-tracer prior was also superior to the single-tracer version in terms of restoring image fidelity. Results of the three-class observer study showed that the proposed cross-tracer prior and the convergent algorithms improved the

  6. Evaluation of leakage from fume hoods using tracer gas, tracer nanoparticles and nanopowder handling test methodologies.

    Science.gov (United States)

    Dunn, Kevin H; Tsai, Candace Su-Jung; Woskie, Susan R; Bennett, James S; Garcia, Alberto; Ellenbecker, Michael J

    2014-01-01

    The most commonly reported control used to minimize workplace exposures to nanomaterials is the chemical fume hood. Studies have shown, however, that significant releases of nanoparticles can occur when materials are handled inside fume hoods. This study evaluated the performance of a new commercially available nano fume hood using three different test protocols. Tracer gas, tracer nanoparticle, and nanopowder handling protocols were used to evaluate the hood. A static test procedure using tracer gas (sulfur hexafluoride) and nanoparticles as well as an active test using an operator handling nanoalumina were conducted. A commercially available particle generator was used to produce sodium chloride tracer nanoparticles. Containment effectiveness was evaluated by sampling both in the breathing zone (BZ) of a mannequin and operator as well as across the hood opening. These containment tests were conducted across a range of hood face velocities (60, 80, and 100 ft/min) and with the room ventilation system turned off and on. For the tracer gas and tracer nanoparticle tests, leakage was much more prominent on the left side of the hood (closest to the room supply air diffuser) although some leakage was noted on the right side and in the BZ sample locations. During the tracer gas and tracer nanoparticle tests, leakage was primarily noted when the room air conditioner was on for both the low and medium hood exhaust airflows. When the room air conditioner was turned off, the static tracer gas tests showed good containment across most test conditions. The tracer gas and nanoparticle test results were well correlated showing hood leakage under the same conditions and at the same sample locations. The impact of a room air conditioner was demonstrated with containment being adversely impacted during the use of room air ventilation. The tracer nanoparticle approach is a simple method requiring minimal setup and instrumentation. However, the method requires the reduction in

  7. Journal: A Review of Some Tracer-Test Design Equations for Tracer-Mass Estimation and Sample Collection Frequency

    Science.gov (United States)

    Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estima...

  8. Conformal radiotherapy with intensity modulation and integrated boost in the head and neck cancers: experience of the Curie Institute

    International Nuclear Information System (INIS)

    Toledano, I.; Serre, A.; Bensadoun, R.J.; Ortholan, C.; Racadot, S.; Calais, G.; Alfonsi, M.; Giraud, P.; Graff, P.; Serre, A.; Bensadoun, R.J.; Ortholan, C.; Racadot, S.; Calais, G.; Alfonsi, M.; Giraud, P.

    2009-01-01

    The modulated intensity radiotherapy (I.M.R.T.) is used in the treatment of cancers in superior aero digestive tracts to reduce the irradiation of parotids and to reduce the delayed xerostomia. This retrospective study presents the results got on the fourteen first patients according an original technique of I.M.R.T. with integrated boost. It appears that this technique is feasible and allows to reduce the xerostomia rate without modifying the local control rate. To limit the average dose to the parotids under 30 Gy seems reduce the incidence of severe xerostomia. (N.C.)

  9. First Experiences in Intensity Modulated Radiation Surgery at the National Institute of Neurology and Neurosurgery: A Dosimetric Point of View

    International Nuclear Information System (INIS)

    Larraga-Gutierrez, Jose M.; Celis-Lopez, Miguel A.

    2003-01-01

    The National Institute of Neurology and Neurosurgery in Mexico City has acquired a Novalis registered shaped beam radiosurgery unit. The institute is pioneer in the use of new technologies for neuroscience. The Novalis registered unit allows the use of conformal beam radiosurgery/therapy and the more advanced modality of conformal therapy: Intensity Modulated Radiation Therapy (IMRT). In the present work we present the first cases of treatments that use the IMRT technique and show its ability to protect organs at risk, such as brainstem and optical vias

  10. Exchange Transfusion in the Treatment of Neonatal Septic Shock: A Ten-Year Experience in a Neonatal Intensive Care Unit

    OpenAIRE

    Pugni, Lorenza; Ronchi, Andrea; Bizzarri, Bianca; Consonni, Dario; Pietrasanta, Carlo; Ghirardi, Beatrice; Fumagalli, Monica; Ghirardello, Stefano; Mosca, Fabio

    2016-01-01

    Septic shock, occurring in about 1% of neonates hospitalized in neonatal intensive care unit (NICU), is a major cause of death in the neonatal period. In the 1980s and 90s, exchange transfusion (ET) was reported by some authors to be effective in the treatment of neonatal sepsis and septic shock. The main aim of this retrospective study was to compare the mortality rate of neonates with septic shock treated only with standard care therapy (ScT group) with the mortality rate of those treated w...

  11. First Experiences in Intensity Modulated Radiation Surgery at the National Institute of Neurology and Neurosurgery: A Dosimetric Point of View

    Science.gov (United States)

    Lárraga-Gutiérrez, José M.; Celis-López, Miguel A.

    2003-09-01

    The National Institute of Neurology and Neurosurgery in Mexico City has acquired a Novalis® shaped beam radiosurgery unit. The institute is pioneer in the use of new technologies for neuroscience. The Novalis® unit allows the use of conformal beam radiosurgery/therapy and the more advanced modality of conformal therapy: Intensity Modulated Radiation Therapy (IMRT). In the present work we present the first cases of treatments that use the IMRT technique and show its ability to protect organs at risk, such as brainstem and optical vias.

  12. Luminescent two-color tracer particles for simultaneous velocity and temperature measurements in microfluidics

    International Nuclear Information System (INIS)

    Massing, J; Kähler, C J; Cierpka, C; Kaden, D

    2016-01-01

    The simultaneous and non-intrusive measurement of temperature and velocity fields in flows is of great scientific and technological interest. To sample the velocity and temperature, tracer particle based approaches have been developed, where the velocity is measured using PIV or PTV and the temperature is obtained from the intensity (LIF, thermographic phosphors) or frequency (TLC) of the light emitted or reflected by the tracer particles. In this article, a measurement technique is introduced, that relates the luminescent intensity ratio of individual dual-color luminescent tracer particles to temperature. Different processing algorithms are tested on synthetic particle images and compared with respect to their accuracy in estimating the intensity ratio. Furthermore, polymer particles which are doped with the temperature sensitive dye europium (III) thenoyltrifluoroacetonate (EuTTA) and the nearly temperature insensitive reference dye perylene are characterized as valid tracers. The results show a reduction of the temperature measurement uncertainty of almost 40% (95% confidence interval) compared to previously reported luminescent particle based measurement techniques for microfluidics. (paper)

  13. Diffusive partitioning tracer test for the quantification of nonaqueous phase liquid (NAPL) in the vadose zone: performance evaluation for heterogeneous NAPL distribution.

    Science.gov (United States)

    Werner, David; Karapanagioti, Hrissi K; Höhener, Patrick

    2009-08-11

    A partitioning tracer test based on gas-phase diffusion in the vadose zone yields estimates of the residual nonaqueous phase liquid (NAPL) saturation. The present paper investigates this technique further by studying diffusive tracer breakthrough curves in the vadose zone for a heterogeneous NAPL distribution. Tracer experiments were performed in a lysimeter with a horizontal layer of artificial kerosene embedded in unsaturated sand. Tracer disappearance curves at the injection point and tracer breakthrough curves at some distance from the injection point were measured inside and outside of the NAPL layer. A numerical code was used to generate independent model predictions based on the physicochemical sand, NAPL, and tracer properties. The measured and modeled tracer breakthrough curves were in good agreement confirming the validity of important modeling assumptions such as negligible sorption of chlorofluorocarbon (CFC) tracers to the uncontaminated sand and their fast reversible partitioning between the soil air and the NAPL phase. Subsequently, the model was used to investigate different configurations of NAPL contamination. The experimental and model results show that the tracer disappearance curves of a single-well diffusive partitioning tracer test (DPTT) are dominated by the near-field presence of NAPL around the tip of the soil gas probe. In contrast, breakthrough curves of inter-well tracer tests reflect the NAPL saturation in between the probes, although there is no unique interpretation of the tracer signals if the NAPL distribution is heterogeneous. Numerical modeling is useful for the planning of a DPTT application. Simulations suggest that several cubic meters of soil can be investigated with a single inter-well partitioning tracer test of 24-hour duration by placing the injection point in the center of the investigated soil volume and probes at up to 1 m distance for the monitoring of gaseous tracers.

  14. Proceedings of Tracer 3. International Conference on Tracers and Tracing Methods

    International Nuclear Information System (INIS)

    2004-01-01

    Tracer 3 conference is a continuation of former Tracer 1 (1998) and Tracer 2 (2001) conferences organized by CNRS - Nancy France. The objective of this 3rd conference is presentation of different aspects of tracer method applications and development of tracer methodology.The new field of activity presented at the Conference was application of stable isotopes as natural tracers for investigations of environmental processes. The conference gave the possibility for scientific information exchange between specialists from different fields of activity such as chemical engineering, chemistry, bioengineering, environmental engineering, hydrology, civil engineering, metallurgy, etc. The presentations were divided into groups covering the principal items of Conference. Section A. Fundamental development - RTD and tracer methodology, - RTD methodology and Computational Fluid Dynamics (CFD), - New tracers and detectors. Section B. Industrial applications - Environment, - Geology, hydrogeology and oil field applications, - Civil engineering, mineral engineering and metallurgy applications, - Food engineering and bioengineering, - Material engineering, - Chemical engineering. During the Conference INIS promotion materials were exposed by INIS liaison officer for Poland

  15. Long residence times - bad tracer tests?

    Science.gov (United States)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2015-04-01

    Tracer tests conducted at geothermal well doublets or triplets in the Upper Rhine Rift Valley [1] all face, with very few exceptions so far, one common issue: lack of conclusive tracer test results, or tracer signals still undetectable for longer than one or two years after tracer injection. While the reasons for this surely differ from site to site (Riehen, Landau, Insheim, Bruchsal, ...), its effects on how the usefulness of tracer tests is perceived by the non-tracer community are pretty much the same. The 'poor-signal' frustration keeps nourishing two major 'alternative' endeavours : (I) design and execute tracer tests in single-well injection-withdrawal (push-pull), 'instead of' inter-well flow-path tracing configurations; (II) use 'novel' tracer substances instead of the 'old' ones which have 'obviously failed'. Frustration experienced with most inter-well tracer tests in the Upper Rhine Rift Valley has also made them be regarded as 'maybe useful for EGS' ('enhanced', or 'engineered' geothermal systems, whose fluid RTD typically include a major share of values below one year), but 'no longer worthwhile a follow-up sampling' in natural, large-scale hydrothermal reservoirs. We illustrate some of these arguments with the ongoing Bruchsal case [2]. The inter-well tracer test conducted at Bruchsal was (and still is!) aimed at assessing inter-well connectivity, fluid residence times, and characterizing the reservoir structure [3]. Fluid samples taken at the geothermal production well after reaching a fluid turnover of about 700,000 m3 showed tracer concentrations in the range of 10-8 Minj per m3, in the liquid phase of each sample (Minj being the total quantity of tracer injected as a short pulse at the geothermal re-injection well). Tracer signals might actually be higher, owing to tracer amounts co-precipitated and/or adsorbed onto the solid phase whose accumulation in the samples was unavoidable (due to pressure relief and degassing during the very sampling

  16. In situ measurement of methane oxidation in groundwater by using natural-gradient tracer tests

    International Nuclear Information System (INIS)

    Smith, R.L.; Howes, B.L.; Garabedian, S.P.

    1991-01-01

    Methane oxidation was measured in an unconfined sand and gravel aquifer (Cape Cod, Mass.) by using in situ natural-gradient tracer tests at both a pristine, oxygenated site and an anoxic, sewage-contaminated site. The tracer sites were equipped with multilevel sampling devices to create target grids of sampling points; the injectate was prepared with groundwater from the tracer site to maintain the same geochemical conditions. Methane oxidation was calculated from breakthrough curves of methane relative to halide and inert gas (hexafluoroethane) tracers and was confirmed by the appearance of 13 C-enriched carbon dioxide in experiments in which 13 C-enriched methane was used as the tracer. A V max for methane oxidation could be calculated when the methane concentration was sufficiently high to result in zero-order kinetics throughout the entire transport interval. Methane breakthrough curves could be simulated by modifying a one-dimensional advection-dispersion transport model to include a Michaelis-Menten-based consumption term for methane oxidation. The K m values for methane oxidation that gave the best match for the breakthrough curve peaks were 6.0 and 9.0 μM for the uncontaminated and contaminated sites, respectively. Natural-gradient tracer tests are a promising approach for assessing microbial processes and for testing in situ bioremediation potential in groundwater systems

  17. Evaluation of 13C isotopic tracers for metabolic flux analysis in mammalian cells.

    Science.gov (United States)

    Metallo, Christian M; Walther, Jason L; Stephanopoulos, Gregory

    2009-11-01

    (13)C metabolic flux analysis (MFA) is the most comprehensive means of characterizing cellular metabolic states. Uniquely labeled isotopic tracers enable more focused analyses to probe specific reactions within the network. As a result, the choice of tracer largely determines the precision with which one can estimate metabolic fluxes, especially in complex mammalian systems that require multiple substrates. Here we have experimentally determined metabolic fluxes in a tumor cell line, successfully recapitulating the hallmarks of cancer cell metabolism. Using these data, we computationally evaluated specifically labeled (13)C glucose and glutamine tracers for their ability to precisely and accurately estimate fluxes in central carbon metabolism. These methods enabled us to identify the optimal tracer for analyzing individual fluxes, specific pathways, and central carbon metabolism as a whole. [1,2-(13)C(2)]glucose provided the most precise estimates for glycolysis, the pentose phosphate pathway, and the overall network. Tracers such as [2-(13)C]glucose and [3-(13)C]glucose also outperformed the more commonly used [1-(13)C]glucose. [U-(13)C(5)]glutamine emerged as the preferred isotopic tracer for the analysis of the tricarboxylic acid (TCA) cycle. These results provide valuable, quantitative information on the performance of (13)C-labeled substrates and can aid in the design of more informative MFA experiments in mammalian cell culture.

  18. Two-dimensional thermal simulations of aluminum and carbon ion strippers for experiments at SPIRAL2 using the highest beam intensities

    International Nuclear Information System (INIS)

    Tahir, N.A.; Kim, V.; Lamour, E.; Lomonosov, I.V.; Piriz, A.R.; Rozet, J.P.; Stöhlker, Th.; Sultanov, V.; Vernhet, D.

    2012-01-01

    In this paper we report on two-dimensional numerical simulations of heating of a rotating, wheel shaped target impacted by the full intensity of the ion beam that will be delivered by the SPIRAL2 facility at Caen, France. The purpose of this work is to study heating of solid targets that will be used to strip the fast ions of SPIRAL2 to the required high charge state for the FISIC (Fast Ion–Slow Ion Collision) experiments. Strippers of aluminum with different emissivities and of carbon are exposed to high beam current of different ion species as oxygen, neon and argon. These studies show that carbon, due to its much higher sublimation temperature and much higher emissivity, is more favorable compared to aluminum. For the highest beam intensities, an aluminum stripper does not survive. However, problem of the induced thermal stresses and long term material fatigue needs to be investigated before a final conclusion can be drawn.

  19. Two-dimensional thermal simulations of aluminum and carbon ion strippers for experiments at SPIRAL2 using the highest beam intensities

    Science.gov (United States)

    Tahir, N. A.; Kim, V.; Lamour, E.; Lomonosov, I. V.; Piriz, A. R.; Rozet, J. P.; Stöhlker, Th.; Sultanov, V.; Vernhet, D.

    2012-11-01

    In this paper we report on two-dimensional numerical simulations of heating of a rotating, wheel shaped target impacted by the full intensity of the ion beam that will be delivered by the SPIRAL2 facility at Caen, France. The purpose of this work is to study heating of solid targets that will be used to strip the fast ions of SPIRAL2 to the required high charge state for the FISIC (Fast Ion-Slow Ion Collision) experiments. Strippers of aluminum with different emissivities and of carbon are exposed to high beam current of different ion species as oxygen, neon and argon. These studies show that carbon, due to its much higher sublimation temperature and much higher emissivity, is more favorable compared to aluminum. For the highest beam intensities, an aluminum stripper does not survive. However, problem of the induced thermal stresses and long term material fatigue needs to be investigated before a final conclusion can be drawn.

  20. TRACER - TRACING AND CONTROL OF ENGINEERING REQUIREMENTS

    Science.gov (United States)

    Turner, P. R.

    1994-01-01

    TRACER (Tracing and Control of Engineering Requirements) is a database/word processing system created to document and maintain the order of both requirements and descriptive material associated with an engineering project. A set of hierarchical documents are normally generated for a project whereby the requirements of the higher level documents levy requirements on the same level or lower level documents. Traditionally, the requirements are handled almost entirely by manual paper methods. The problem with a typical paper system, however, is that requirements written and changed continuously in different areas lead to misunderstandings and noncompliance. The purpose of TRACER is to automate the capture, tracing, reviewing, and managing of requirements for an engineering project. The engineering project still requires communications, negotiations, interactions, and iterations among people and organizations, but TRACER promotes succinct and precise identification and treatment of real requirements separate from the descriptive prose in a document. TRACER permits the documentation of an engineering project's requirements and progress in a logical, controllable, traceable manner. TRACER's attributes include the presentation of current requirements and status from any linked computer terminal and the ability to differentiate headers and descriptive material from the requirements. Related requirements can be linked and traced. The program also enables portions of documents to be printed, individual approval and release of requirements, and the tracing of requirements down into the equipment specification. Requirement "links" can be made "pending" and invisible to others until the pending link is made "binding". Individuals affected by linked requirements can be notified of significant changes with acknowledgement of the changes required. An unlimited number of documents can be created for a project and an ASCII import feature permits existing documents to be incorporated

  1. High-Intensity Focused Ultrasound (HIFU) Using Sonablate-500 for the Treatment of Localized Prostate Cancer: 6-year experience

    Science.gov (United States)

    Uchida, Toyoaki; Shoji, Sunao; Nagata, Yoshihiro

    2006-05-01

    We evaluated 281 patients of localized prostate cancer treated with high-intensity focused ultrasound (HIFU) for biochemical disease-free rate, safety, morbidity and predictors of biochemical outcome. A total of 281 patients underwent HIFU with the use of Sonablate-500 and with at least 12 months of follow-up. Biochemical failure was defined according to the criteria recommended by the American Society for Therapeutic Radiology and Oncology Consensus Panel. The biochemical disease-free rates at 1, 3 and 5 years in all patients were 78%, 74% and 72%, respectively. The biochemical disease-free rates at 5 years for patients with pretreatment PSA less than 10 ng/ml, 10.01 to 20.0 ng/ml and more than 20.0 ng/ml were 88%, 70% and 17%, respectively (ppatients with localized prostate cancer, especially those with a pretreatment PSA level less than 20 ng/ml.

  2. A novel femtosecond-gated, high-resolution, frequency-shifted shearing interferometry technique for probing pre-plasma expansion in ultra-intense laser experiments

    Energy Technology Data Exchange (ETDEWEB)

    Feister, S., E-mail: feister.7@osu.edu; Orban, C. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Nees, J. A. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Center for Ultra-Fast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Morrison, J. T. [Fellow, National Research Council, Washington, D.C. 20001 (United States); Frische, K. D. [Innovative Scientific Solutions, Inc., Dayton, Ohio 45459 (United States); Chowdhury, E. A. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Intense Energy Solutions, LLC., Plain City, Ohio 43064 (United States); Roquemore, W. M. [Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

    2014-11-15

    Ultra-intense laser-matter interaction experiments (>10{sup 18} W/cm{sup 2}) with dense targets are highly sensitive to the effect of laser “noise” (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a robust way to characterize the expanding plasma during this period. We have developed a novel pump-probe interferometry system for an ultra-intense laser experiment that uses two short-pulse amplifiers synchronized by one ultra-fast seed oscillator to achieve 40-fs time resolution over hundreds of nanoseconds, using a variable delay line and other techniques. The first of these amplifiers acts as the pump and delivers maximal energy to the interaction region. The second amplifier is frequency shifted and then frequency doubled to generate the femtosecond probe pulse. After passing through the laser-target interaction region, the probe pulse is split and recombined in a laterally sheared Michelson interferometer. Importantly, the frequency shift in the probe allows strong plasma self-emission at the second harmonic of the pump to be filtered out, allowing plasma expansion near the critical surface and elsewhere to be clearly visible in the interferograms. To aid in the reconstruction of phase dependent imagery from fringe shifts, three separate 120° phase-shifted (temporally sheared) interferograms are acquired for each probe delay. Three-phase reconstructions of the electron densities are then inferred by Abel inversion. This interferometric system delivers precise measurements of pre-plasma expansion that can identify the condition of the target at the moment that the ultra-intense pulse arrives. Such measurements are indispensable for correlating laser pre-pulse measurements

  3. The Failure Patterns of Oral Cavity Squamous Cell Carcinoma After Intensity-Modulated Radiotherapy-University of Iowa Experience

    International Nuclear Information System (INIS)

    Yao Min; Chang, Kristi; Funk, Gerry F.; Lu Heming; Tan Huaming; Wacha, Judith C; Dornfeld, Kenneth J.; Buatti, John M.

    2007-01-01

    Purpose: Determine the failure patterns of oral cavity squamous cell carcinoma (SCC) treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: Between May 2001 and July 2005, 55 patients with oral cavity SCC were treated with IMRT for curative intent. Forty-nine received postoperative IMRT, 5 definitive IMRT, and 1 neoadjuvant. Three target volumes were defined (clinical target CTV1, CTV2, and CTV3). The failure patterns were determined by coregistration or comparison of the treatment planning computed tomography to the images obtained at the time of recurrence. Results: The median follow-up for all patients was 17.1 months (range, 0.27-59.3 months). The median follow-up for living patients was 23.9 months (range, 9.3-59.3 months). Nine patients had locoregional failures: 4 local failures only, 2 regional failures only, and 3 had both local and regional failures. Five patients failed distantly; of these, 3 also had locoregional failures. The 2-year overall survival, disease-specific survival, local recurrence-free survival, locoregional recurrence-free survival, and distant disease-free survival was 68%, 74%, 85%, 82%, and 89%, respectively. The median time from treatment completion to locoregional recurrence was 4.1 months (range, 3.0-12.1 months). Except for 1 patient who failed in contralateral lower neck outside the radiation field, all failed in areas that had received a high dose of radiation. The locoregional control is strongly correlated with extracapsular extension. Conclusions: Intensity-modulated RT is effective for oral cavity SCC. Most failures are in-field failures. Further clinical studies are necessary to improve the outcomes of patients with high-risk features, particularly for those with extracapsular extension

  4. BENEFITS OF INTENSITY-MODULATED RADIOTHERAPY (IMRT IN PATIENTS WITH HEAD AND NECK MALIGNANCIES- A SINGLE INSTITUTION EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Sherry Seasor Abraham

    2017-09-01

    Full Text Available BACKGROUND Radiotherapy and surgery are the principal curative modalities in treatment of head and neck cancer. Conventional twodimensional and three-dimensional conformal radiotherapy result in significant side effects and altered quality of life. IntensityModulated Radiotherapy (IMRT can spare the normal tissues, while delivering a curative dose to the tumour-bearing tissues. This study reveals the role of IMRT in head and neck cancer in view of normal tissue sparing with good tumour control. MATERIALS AND METHODS Radical radiotherapy was given using linear accelerator up to a dose of 66 to 70 gray in 30 to 33 fractions (intensity-modulated radiotherapy with simultaneous integrated boost over 6 to 7 weeks to 56 eligible patients. Concurrent cisplatin was given to patients with locally-advanced disease up to a dose of 40 mg/m2 weekly once along with radiation. The patients were monitored weekly once during the treatment for acute skin and mucosal toxicities using the RTOG scoring criteria. After the treatment, locoregional response was assessed and recorded at 6 weeks, 3 months and 6 months intervals. RESULTS Severe skin toxicity (grade III or more was seen in approximately 7% patients. Severe mucosal toxicity (grade III or more was seen in approximately 80% of patients. IMRT technique showed better skin sparing compared to 3D conformal radiotherapy. Severe mucosal toxicity was slightly higher in this study due to the simultaneous integrated boost technique used for dose intensification to the mucosa, which results in better primary tumour control. At the end of 6 months, 75% patients achieved locoregional control and residual/recurrent disease was seen in 25% of patients. IMRT offered good locoregional control with less skin toxicity and acceptable mucosal toxicity. The results were similar to the previous study reports using IMRT. CONCLUSION IMRT is a better treatment option in locally-advanced head and neck malignancies providing good

  5. Gastrostomy Tube Weaning and Treatment of Severe Selective Eating in Childhood: Experience in Israel Using an Intensive Three Week Program.

    Science.gov (United States)

    Shalem, Tzippora; Fradkin, Akiva; Dunitz-Scheer, Marguerite; Sadeh-Kon, Tal; Goz-Gulik, Tali; Fishler, Yael; Weiss, Batia

    2016-06-01

    Children dependent on gastrostomy tube feeding and those with extremely selective eating comprise the most challenging groups of early childhood eating disorders. We established, for the first time in Israel, a 3 week intensive weaning and treatment program for these patients based on the "Graz model." To investigate the Graz model for tube weaning and for treating severe selective eating disorders in one center in Israel. Pre-program assessment of patients' suitability to participate was performed 3 months prior to the study, and a treatment goal was set for each patient. The program included a multidisciplinary outpatient or inpatient 3 week treatment course. The major outcome measures were achievement of the target goal of complete or partial tube weaning for those with tube dependency, and expansion of the child's nutritional diversity for those with selective eating. Thirty-four children, 28 with tube dependency and 6 with selective eating, participated in four programs conducted over 24 months. Their mean age was 4.3 ± 0.37 years. Of all patients, 29 (85%) achieved the target goal (24 who were tube-dependent and 5 selective eaters). One patient was excluded due to aspiration pneumonia. After 6 months follow-up, 24 of 26 available patients (92%) maintained their target or improved. This intensive 3 week program was highly effective in weaning children with gastrostomy tube dependency and ameliorating severe selective eating. Preliminary evaluation of the family is necessary for completion of the program and achieving the child's personal goal, as are an experienced multidisciplinary team and the appropriate hospital setup, i.e., inpatient or outpatient.

  6. rFRET: A comprehensive, Matlab-based program for analyzing intensity-based ratiometric microscopic FRET experiments.

    Science.gov (United States)

    Nagy, Peter; Szabó, Ágnes; Váradi, Tímea; Kovács, Tamás; Batta, Gyula; Szöllősi, János

    2016-04-01

    Fluorescence or Förster resonance energy transfer (FRET) remains one of the most widely used methods for assessing protein clustering and conformation. Although it is a method with solid physical foundations, many applications of FRET fall short of providing quantitative results due to inappropriate calibration and controls. This shortcoming is especially valid for microscopy where currently available tools have limited or no capability at all to display parameter distributions or to perform gating. Since users of multiparameter flow cytometry usually apply these tools, the absence of these features in applications developed for microscopic FRET analysis is a significant limitation. Therefore, we developed a graphical user interface-controlled Matlab application for the evaluation of ratiometric, intensity-based microscopic FRET measurements. The program can calculate all the necessary overspill and spectroscopic correction factors and the FRET efficiency and it displays the results on histograms and dot plots. Gating on plots and mask images can be used to limit the calculation to certain parts of the image. It is an important feature of the program that the calculated parameters can be determined by regression methods, maximum likelihood estimation (MLE) and from summed intensities in addition to pixel-by-pixel evaluation. The confidence interval of calculated parameters can be estimated using parameter simulations if the approximate average number of detected photons is known. The program is not only user-friendly, but it provides rich output, it gives the user freedom to choose from different calculation modes and it gives insight into the reliability and distribution of the calculated parameters. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

  7. Tracers of air-sea gas exchange

    International Nuclear Information System (INIS)

    Liss, P.S.

    1988-01-01

    The flux of gas across the air-sea interface is determined by the product of the interfacial concentration difference driving the exchange and a rate constant, often termed the transfer velocity. The concentration-difference term is generally obtained by direct measurement, whereas more indirect approaches are required to estimate the transfer velocity and its variation as a function of controlling parameters such as wind and sea state. Radioactive tracers have proved particularly useful in the estimation of air-sea transfer velocities and, recently, stable purposeful tracers have also started to be used. In this paper the use of the following tracers to determine transfer velocities at the sea surface is discussed: natural and bomb-produced 14 C, dissolved oxygen, 222 Rn and sulphur hexafluoride. Other topics covered include the relation between transfer velocity and wind speed as deduced from tracer and wind-tunnel studies, and the discrepancy between transfer velocities determined by using tracers and from eddy correlation measurements in the atmosphere. (author)

  8. Estimating fracture spacing from natural tracers in shale-gas production

    Science.gov (United States)

    Bauer, S. J.; McKenna, S. A.; Heath, J. E.; Gardner, P.

    2012-12-01

    Resource appraisal and long-term recovery potential of shale gas relies on the characteristics of the fracture networks created within the formation. Both well testing and analysis of micro-seismic data can provide information on fracture characteristics, but approaches that directly utilize observations of gas transport through the fractures are not well-developed. We examine transport of natural tracers and analyze the breakthrough curves (BTC's) of these tracers with a multi-rate mass transfer (MMT) model to elucidate fracture characteristics. The focus here is on numerical simulation studies to determine constraints on the ability to accurately estimate fracture network characteristics as a function of the diffusion coefficients of the natural tracers, the number and timing of observations, the flow rates from the well, and the noise in the observations. Traditional tracer testing approaches for dual-porosity systems analyze the BTC of an injected tracer to obtain fracture spacing considering a single spacing value. An alternative model is the MMT model where diffusive mass transfer occurs simultaneously over a range of matrix block sizes defined by a statistical distribution (e.g., log-normal, gamma, or power-law). The goal of the estimation is defining the parameters of the fracture spacing distribution. The MMT model has not yet been applied to analysis of natural in situ natural tracers. Natural tracers are omnipresent in the subsurface, potentially obviating the needed for introduced tracers, and could be used to improve upon fracture characteristics estimated from pressure transient and decline curve production analysis. Results of this study provide guidance for data collection and analysis of natural tracers in fractured shale formations. Parameter estimation on simulated BTC's will provide guidance on the necessary timing of BTC sampling in field experiments. The MMT model can result in non-unique or nonphysical parameter estimates. We address this

  9. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  10. Kangaroo Care: Experiences and Needs of Parents in Neonatal Intensive Care: A Systematic Review ‘Parents’ Experience of Kangaroo Care’

    NARCIS (Netherlands)

    Gabriels, karlijn; Brouwer, AJ|info:eu-repo/dai/nl/334070805; maat, Jessica; van den Hoogen, Agnes|info:eu-repo/dai/nl/343075156

    2015-01-01

    Abstract This review is focusing on the experiences and needs of parents with infants within NICU regarding Kangaroo Care. Ten studies with qualitative designs were included. Kangaroo Care was overall experienced as positive; giving parents the opportunity to get to know their babies and (re-)

  11. Pixel-based absorption correction for dual-tracer fluorescence imaging of receptor binding potential.

    Science.gov (United States)

    Kanick, Stephen C; Tichauer, Kenneth M; Gunn, Jason; Samkoe, Kimberley S; Pogue, Brian W

    2014-10-01

    Ratiometric approaches to quantifying molecular concentrations have been used for decades in microscopy, but have rarely been exploited in vivo until recently. One dual-tracer approach can utilize an untargeted reference tracer to account for non-specific uptake of a receptor-targeted tracer, and ultimately estimate receptor binding potential quantitatively. However, interpretation of the relative dynamic distribution kinetics is confounded by differences in local tissue absorption at the wavelengths used for each tracer. This study simulated the influence of absorption on fluorescence emission intensity and depth sensitivity at typical near-infrared fluorophore wavelength bands near 700 and 800 nm in mouse skin in order to correct for these tissue optical differences in signal detection. Changes in blood volume [1-3%] and hemoglobin oxygen saturation [0-100%] were demonstrated to introduce substantial distortions to receptor binding estimates (error > 30%), whereas sampled depth was relatively insensitive to wavelength (error pixel-by-pixel normalization of tracer inputs immediately post-injection was found to account for spatial heterogeneities in local absorption properties. Application of the pixel-based normalization method to an in vivo imaging study demonstrated significant improvement, as compared with a reference tissue normalization approach.

  12. Pixel-based absorption correction for dual-tracer fluorescence imaging of receptor binding potential

    Science.gov (United States)

    Kanick, Stephen C.; Tichauer, Kenneth M.; Gunn, Jason; Samkoe, Kimberley S.; Pogue, Brian W.

    2014-01-01

    Ratiometric approaches to quantifying molecular concentrations have been used for decades in microscopy, but have rarely been exploited in vivo until recently. One dual-tracer approach can utilize an untargeted reference tracer to account for non-specific uptake of a receptor-targeted tracer, and ultimately estimate receptor binding potential quantitatively. However, interpretation of the relative dynamic distribution kinetics is confounded by differences in local tissue absorption at the wavelengths used for each tracer. This study simulated the influence of absorption on fluorescence emission intensity and depth sensitivity at typical near-infrared fluorophore wavelength bands near 700 and 800 nm in mouse skin in order to correct for these tissue optical differences in signal detection. Changes in blood volume [1-3%] and hemoglobin oxygen saturation [0-100%] were demonstrated to introduce substantial distortions to receptor binding estimates (error > 30%), whereas sampled depth was relatively insensitive to wavelength (error tracer inputs immediately post-injection was found to account for spatial heterogeneities in local absorption properties. Application of the pixel-based normalization method to an in vivo imaging study demonstrated significant improvement, as compared with a reference tissue normalization approach. PMID:25360349

  13. Simulation and interpretation of inter-well tracer tests

    Science.gov (United States)

    Huseby, Olaf; Sagen, Jan; Viig, Sissel; Dugstad, Øyvind

    2013-05-01

    In inter-well tracer tests (IWTT), chemical compounds or radioactive isotopes are used to label injection water and gas to establish well connections and fluid patterns in petroleum reservoirs. Tracer simulation is an invaluable tool to ease the interpretation of IWTT results and is also required for assisted history matching application of tracer data. In this paper we present a new simulation technique to analyse and interpret tracer results. Laboratory results are used to establish and test formulations of the tracer conservation equations, and the technique is used to provide simulated tracer responses that are compared with observed tracer data from an extensive tracer program. The implemented tracer simulation methodology use a fast post-processing of previously simulated reservoir simulation runs. This provides a fast, flexible and powerful method for analysing gas tracer behaviour in reservoirs. We show that simulation time for tracers can be reduced by factor 100 compared to solving the tracer flow equations simultaneously with the reservoir fluid flow equations. The post-processing technique, combined with a flexible built-in local tracer-grid refinement is exploited to reduce numerical smearing, particularly severe for narrow tracer pulses.

  14. Rapid Multi-Tracer PET Tumor Imaging With F-FDG and Secondary Shorter-Lived Tracers.

    Science.gov (United States)

    Black, Noel F; McJames, Scott; Kadrmas, Dan J

    2009-10-01

    Rapid multi-tracer PET, where two to three PET tracers are rapidly scanned with staggered injections, can recover certain imaging measures for each tracer based on differences in tracer kinetics and decay. We previously showed that single-tracer imaging measures can be recovered to a certain extent from rapid dual-tracer (62)Cu - PTSM (blood flow) + (62)Cu - ATSM (hypoxia) tumor imaging. In this work, the feasibility of rapidly imaging (18)F-FDG plus one or two of these shorter-lived secondary tracers was evaluated in the same tumor model. Dynamic PET imaging was performed in four dogs with pre-existing tumors, and the raw scan data was combined to emulate 60 minute long dual- and triple-tracer scans, using the single-tracer scans as gold standards. The multi-tracer data were processed for static (SUV) and kinetic (K(1), K(net)) endpoints for each tracer, followed by linear regression analysis of multi-tracer versus single-tracer results. Static and quantitative dynamic imaging measures of FDG were both accurately recovered from the multi-tracer scans, closely matching the single-tracer FDG standards (R > 0.99). Quantitative blood flow information, as measured by PTSM K(1) and SUV, was also accurately recovered from the multi-tracer scans (R = 0.97). Recovery of ATSM kinetic parameters proved more difficult, though the ATSM SUV was reasonably well recovered (R = 0.92). We conclude that certain additional information from one to two shorter-lived PET tracers may be measured in a rapid multi-tracer scan alongside FDG without compromising the assessment of glucose metabolism. Such additional and complementary information has the potential to improve tumor characterization in vivo, warranting further investigation of rapid multi-tracer techniques.

  15. Rapid Multi-Tracer PET Tumor Imaging With 18F-FDG and Secondary Shorter-Lived Tracers

    Science.gov (United States)

    Black, Noel F.; McJames, Scott; Kadrmas, Dan J.

    2009-01-01

    Rapid multi-tracer PET, where two to three PET tracers are rapidly scanned with staggered injections, can recover certain imaging measures for each tracer based on differences in tracer kinetics and decay. We previously showed that single-tracer imaging measures can be recovered to a certain extent from rapid dual-tracer 62Cu – PTSM (blood flow) + 62Cu — ATSM (hypoxia) tumor imaging. In this work, the feasibility of rapidly imaging 18F-FDG plus one or two of these shorter-lived secondary tracers was evaluated in the same tumor model. Dynamic PET imaging was performed in four dogs with pre-existing tumors, and the raw scan data was combined to emulate 60 minute long dual- and triple-tracer scans, using the single-tracer scans as gold standards. The multi-tracer data were processed for static (SUV) and kinetic (K1, Knet) endpoints for each tracer, followed by linear regression analysis of multi-tracer versus single-tracer results. Static and quantitative dynamic imaging measures of FDG were both accurately recovered from the multi-tracer scans, closely matching the single-tracer FDG standards (R > 0.99). Quantitative blood flow information, as measured by PTSM K1 and SUV, was also accurately recovered from the multi-tracer scans (R = 0.97). Recovery of ATSM kinetic parameters proved more difficult, though the ATSM SUV was reasonably well recovered (R = 0.92). We conclude that certain additional information from one to two shorter-lived PET tracers may be measured in a rapid multi-tracer scan alongside FDG without compromising the assessment of glucose metabolism. Such additional and complementary information has the potential to improve tumor characterization in vivo, warranting further investigation of rapid multi-tracer techniques. PMID:20046800

  16. Enhanced Oil Recovery: Aqueous Flow Tracer Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Rovani; John Schabron

    2009-02-01

    A low detection limit analytical method was developed to measure a suite of benzoic acid and fluorinated benzoic acid compounds intended for use as tracers for enhanced oil recovery operations. Although the new high performance liquid chromatography separation successfully measured the tracers in an aqueous matrix at low part per billion levels, the low detection limits could not be achieved in oil field water due to interference problems with the hydrocarbon-saturated water using the system's UV detector. Commercial instrument vendors were contacted in an effort to determine if mass spectrometry could be used as an alternate detection technique. The results of their work demonstrate that low part per billion analysis of the tracer compounds in oil field water could be achieved using ultra performance liquid chromatography mass spectrometry.

  17. Biological tracer for waste site characterization

    International Nuclear Information System (INIS)

    Strong-Gunderson, J.

    1995-01-01

    Remediating hazardous waste sites requires detailed site characterization. In groundwater remediation, characterizing the flow paths and velocity is a major objective. Various tracers have been used for measuring groundwater velocity and transport of contaminants, colloidal particles, and bacteria and nutrients. The conventional techniques use dissolved solutes, dyes. and gases to estimate subsurface transport pathways. These tracers can provide information on transport and diffusion into the matrix, but their estimates for groundwater flow through fractured regions are very conservative. Also, they do not have the same transport characteristics as bacteria and suspended colloid tracers, both of which must be characterized for effective in-place remediation. Bioremediation requires understanding bacterial transport and nutrient distribution throughout the acquifer, knowledge of contaminants s mobile colloidal particles is just essential

  18. Format of medical order sheet improves security of antibiotics prescription: The experience of an intensive care unit.

    Science.gov (United States)

    Wasserfallen, Jean-Blaise; Bütschi, Anne-Joëlle; Muff, Patrik; Biollaz, Jérôme; Schaller, Marie-Denise; Pannatier, André; Revelly, Jean-Pierre; Chiolero, René

    2004-03-01

    To assess whether formatting the medical order sheet has an effect on the accuracy and security of antibiotics prescription. Prospective assessment of antibiotics prescription over time, before and after the intervention, in comparison with a control ward. The medical and surgical intensive care unit (ICU) of a university hospital. All patients hospitalized in the medical or surgical ICU between February 1 and April 30, 1997, and July 1 and August 31, 2000, for whom antibiotics were prescribed. Formatting of the medical order sheet in the surgical ICU in 1998. Compliance with the American Society of Hospital Pharmacists' criteria for prescription safety was measured. The proportion of safe orders increased in both units, but the increase was 4.6 times greater in the surgical ICU (66% vs. 74% in the medical ICU and 48% vs. 74% in the surgical ICU). For unsafe orders, the proportion of ambiguous orders decreased by half in the medical ICU (9% vs. 17%) and nearly disappeared in the surgical ICU (1% vs. 30%). The only missing criterion remaining in the surgical ICU was the drug dose unit, which could not be preformatted. The aim of antibiotics prescription (either prophylactic or therapeutic) was indicated only in 51% of the order sheets. Formatting of the order sheet markedly increased security of antibiotics prescription. These findings must be confirmed in other settings and with different drug classes. Formatting the medical order sheet decreases the potential for prescribing errors before full computerized prescription is available.

  19. EARLY STAGE RESPONSES OF INTENSIVE CARE UNITS DURING MAJOR DISASTERS: FROM THE EXPERIENCES OF THE GREAT EAST JAPAN EARTHQUAKE.

    Science.gov (United States)

    Shimada, Jiro; Tase, Choichiro; Tsukada, Yasuhiko; Hasegawa, Arifumi; Iida, Hiroshi

    2015-01-01

    The present study investigated the role of intensive care units (ICU) during disasters, including the responses of our ICU following the Great East Japan Earthquake on March 11, 2011. Our ICU comprises 8 beds for postoperative inpatients and those with rapidly deteriorating conditions; 20 beds in an emergency unit for critically ill patients; and 17 beds for neonates. It is important to secure empty beds when a major disaster occurs, as was the case after the Great Hanshin Earthquake, due to the resulting large numbers of trauma patients. Therefore, each ICU section cooperated to ensure sufficient space for admissions following the Great East Japan Earthquake. However, unlike the Great Hanshin Earthquake, securing beds was ultimately unnecessary due to the nature of the recent disaster, which also consisted of a subsequent tsunami and nuclear accident. Therefore, air quality monitoring was required on this occasion due to the risk of environmental radioactive pollution from the nuclear disaster causing problems with artificial respiration management involving atmospheric air. The variability in damage arising during different disasters thus requires a flexible response from ICUs that handle seriously ill patients.

  20. First clinical experience with a dedicated MRI-guided high-intensity focused ultrasound system for breast cancer ablation

    Energy Technology Data Exchange (ETDEWEB)

    Merckel, Laura G.; Knuttel, Floor M.; Peters, Nicky H.G.M.; Mali, Willem P.T.M.; Bosch, Maurice A.A.J. van den [University Medical Center Utrecht, Department of Radiology, HP E 01.132, Utrecht (Netherlands); Deckers, Roel; Moonen, Chrit T.W.; Bartels, Lambertus W. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Dalen, Thijs van [Diakonessenhuis Utrecht, Department of Surgery, Utrecht (Netherlands); Schubert, Gerald [Philips Healthcare, Best (Netherlands); Weits, Teun [Diakonessenhuis Utrecht, Department of Radiology, Utrecht (Netherlands); Diest, Paul J. van [University Medical Center Utrecht, Department of Pathology, Utrecht (Netherlands); Vaessen, Paul H.H.B. [University Medical Center Utrecht, Department of Anesthesiology, Utrecht (Netherlands); Gorp, Joost M.H.H. van [Diakonessenhuis Utrecht, Department of Pathology, Utrecht (Netherlands)

    2016-11-15

    To assess the safety and feasibility of MRI-guided high-intensity focused ultrasound (MR-HIFU) ablation in breast cancer patients using a dedicated breast platform. Patients with early-stage invasive breast cancer underwent partial tumour ablation prior to surgical resection. MR-HIFU ablation was performed using proton resonance frequency shift MR thermometry and an MR-HIFU system specifically designed for breast tumour ablation. The presence and extent of tumour necrosis was assessed by histopathological analysis of the surgical specimen. Pearson correlation coefficients were calculated to assess the relationship between sonication parameters, temperature increase and size of tumour necrosis at histopathology. Ten female patients underwent MR-HIFU treatment. No skin redness or burns were observed in any of the patients. No correlation was found between the applied energy and the temperature increase. In six patients, tumour necrosis was observed with a maximum diameter of 3-11 mm. In these patients, the number of targeted locations was equal to the number of areas with tumour necrosis. A good correlation was found between the applied energy and the size of tumour necrosis at histopathology (Pearson = 0.76, p = 0.002). Our results show that MR-HIFU ablation with the dedicated breast system is safe and results in histopathologically proven tumour necrosis. (orig.)

  1. 3D radiation therapy or intensity-modulated radiotherapy for recurrent and metastatic cervical cancer: the Shanghai Cancer Hospital experience.

    Directory of Open Access Journals (Sweden)

    Su-Ping Liu

    Full Text Available We evaluate the outcomes of irradiation by using three-dimensional radiation therapy (3D-RT or intensity-modulated radiotherapy (IMRT for recurrent and metastatic cervical cancer. Between 2007 and 2010, 50 patients with recurrent and metastatic cervical cancer were treated using 3D-RT or IMRT. The median time interval between the initial treatment and the start of irradiation was 12 (6-51 months. Salvage surgery was performed before irradiation in 5 patients, and 38 patients received concurrent chemotherapy. Sixteen patients underwent 3D-RT, and 34 patients received IMRT. Median follow-up for all the patients was 18.3 months. Three-year overall survival and locoregional control were 56.1% and 59.7%, respectively. Three-year progression-free survival and disease-free survival were 65.3% and 64.3%, respectively. Nine patients developed grade 3 leukopenia. Grade 5 acute toxicity was not observed in any of the patients; however, 2 patients developed Grade 3 late toxicity. 3D-RT or IMRT is effective for the treatment of recurrent and metastatic cervical cancer, with the 3-year overall survival of 56.1%, and its complications are acceptable. Long-term follow-up and further studies are needed to confirm the role of 3D-RT or IMRT in the multimodality management of the disease.

  2. Select critically ill patients at risk of augmented renal clearance: experience in a Malaysian intensive care unit.

    Science.gov (United States)

    Adnan, S; Ratnam, S; Kumar, S; Paterson, D; Lipman, J; Roberts, J; Udy, A A

    2014-11-01

    Augmented renal clearance (ARC) refers to increased solute elimination by the kidneys. ARC has considerable implications for altered drug concentrations. The aims of this study were to describe the prevalence of ARC in a select cohort of patients admitted to a Malaysian intensive care unit (ICU) and to compare measured and calculated creatinine clearances in this group. Patients with an expected ICU stay of patients were included, with a median age of 34 years. Most study participants were male and admitted after trauma. Thirty-nine percent were found to have ARC. These patients were more commonly admitted in emergency (P=0.03), although no other covariants were identified as predicting ARC, likely due to the inclusion criteria and the study being under-powered. Significant imprecision was demonstrated when comparing calculated Cockcroft-Gault creatinine clearance (Crcl) and measured Crcl. Bias was larger in ARC patients, with Cockcroft-Gault Crcl being significantly lower than measured Crcl (P patients with 'normal' serum creatinine concentrations have varied Crcl. Many are at risk of ARC, which may necessitate individualised drug dosing. Furthermore, significant bias and imprecision between calculated and measured Crcl exists, suggesting clinicians should carefully consider which method they employ in assessing renal function.

  3. Radiopharmaceutical Tracers for Neural Progenitor Cells

    International Nuclear Information System (INIS)

    Mangner, Thomas J.

    2006-01-01

    The Technical Report summarizes the results of the synthesis and microPET animal scanning of several compounds labeled with positron-emitting isotopes in normal, neonatal and kainic acid treated (seizure induced) rats as potential PET tracers to image the process of neurogenesis using positron emission tomography (PET). The tracers tested were 3'-deoxy-3'-[F-18]fluorothymidine ([F-18]FLT) and 5'-benzoyl-FTL, 1-(2'-deoxy-2'-[F-18]fluoro-B-D-arabinofuranosyl)-5-bromouracil (FBAU) and 3',5'-dibenzoyl-FBAU, N-[F-18]fluoroacetyl-D-glucosamine (FLAG) and tetraacetyl-FLAG, and L-[1-C-11]leucine

  4. Geologic flow characterization using tracer techniques

    International Nuclear Information System (INIS)

    Klett, R.D.; Tyner, C.E.; Hertel, E.S. Jr.

    1981-04-01

    A new tracer flow-test system has been developed for in situ characterization of geologic formations. This report describes two sets of test equipment: one portable and one for testing in deep formations. Equations are derived for in situ detector calibration, raw data reduction, and flow logging. Data analysis techniques are presented for computing porosity and permeability in unconfined isotropic media, and porosity, permeability and fracture characteristics in media with confined or unconfined two-dimensional flow. The effects of tracer pulse spreading due to divergence, dispersion, and porous formations are also included

  5. SIMULASI JARINGAN KOMPUTER MENGGUNAKAN CISCO PACKET TRACER

    Directory of Open Access Journals (Sweden)

    M Mufadhol

    2012-01-01

    Full Text Available Perkembangan jaringan komputer saat ini begitu pesat, monitoring jaringan komputer akan menjadi suatu hal yang sulit dan rumit. Koneksi jaringan komputer merupakan suatu hal yang mendasar dalam suatu jaringan, karena bila koneksi itu bermasalah maka semua jenis aplikasi yang dijalankan melalui jaringan komputer tidak dapat digunakan. Cisco packet tracer dapat digunakan untuk simulasi yang mencerminkan arsitektur dan juga model dari jaringan komputer pada sistem jaringan yang digunakan. Dengan menggunakan aplikasi cisco packet tracer, simulasi mengenai jaringan dapat dimanfaatkan menjadi informasi tentang keadaan koneksi komputer dalam suatu jaringan.

  6. A risk index for characterising flow pattern in soils using dye tracer distributions.

    Science.gov (United States)

    Schlather, Martin; Huwe, Bernd

    2005-09-01

    A novel risk index for the vulnerability of groundwater by pollutants is defined as the form parameter of the Pareto distribution and estimated from dye tracer experiments. The Pareto distribution appears as the limit distribution of the extreme value theory, which has been applied to an idealized model of drops that run along a path. The properties of the risk index are investigated by a Monte Carlo study, where the paths are modelled by means of Gaussian random fields. The method is applied to three profiles obtained from Brilliant Blue tracer experiments of the soil physics group at ETH Zurich. It is shown that a single profile can be rather well characterised by the risk index. However, due to the high variability of the dye tracer profiles, an estimated number of at least 15 profile pictures are necessary to characterise a soil.

  7. Natural tracer profiles across argillaceous formations: the Claytrac project

    International Nuclear Information System (INIS)

    Mazurek, M.; Alt-Epping, P.; Gimi, Th.; Niklaus Waber, H.; Bath, A.; Gimmi, Th.

    2009-01-01

    Disposal of high-level radioactive waste and spent nuclear fuel in engineered facilities, or repositories, located deep underground in suitable geological formations is being developed worldwide as the reference solution to protect humans and the environment both now and in the future. An important aspect of assessing the long-term safety of deep geological disposal is developing a comprehensive understanding of the geological environment in order to define the initial conditions for the disposal system as well as to provide a sound scientific basis for projecting its future evolution. The transport pathways and mechanisms by which contaminants could migrate in the surrounding host rock are key elements in any safety case. Relevant experiments in laboratories or underground test facilities can provide important information, but the challenge remains in being able to extrapolate the results to the spatial and temporal scales required for performance assessment, which are typically tens to hundreds of metres and from thousands to beyond a million years into the future. Profiles of natural tracers dissolved in pore water of argillaceous rock formations can be considered as large-scale and long-term natural experiments which enable the transport properties to be characterised. The CLAYTRAC Project on Natural Tracer Profiles Across Argillaceous Formations was established by the NEA Clay Club to evaluate the relevance of natural tracer data in understanding past geological evolution and in confirming dominant transport processes. Data were analysed for nine sites to support scientific understanding and development of geological disposal. The outcomes of the project show that, for the sites and clay-rich formations that were studied, there is strong evidence that solute transport is controlled mainly by diffusion. The results can improve site understanding and performance assessment in the context of deep geological disposal and have the potential to be applied to other

  8. Breeders: operational experience with fast power reactors in five states - more intensive German-French breeder cooperation

    International Nuclear Information System (INIS)

    Hueper, R.

    1978-01-01

    In the past year contracts have been signed and implemented for German-French cooperation in LMFBR development and commercialization. - The first German nuclear power station with a sodium cooled fast reactor, KNK II in Karlsruhe, is going into operation. - Construction of the prototype SNR 300 at Kalkar (Lower Rhine) is slowing down awaiting a decision of the German Federal Constitutional Court. - On the international level, remarkable experience in the operation of fast power reactors has accumulated. - Possible fuel cycle alternatives are being evaluated by an international committee. (orig.) [de

  9. On the possibility of realising a low intensity interference experiment with a determination of the particle trajectory

    International Nuclear Information System (INIS)

    Gozzini, A.

    1984-01-01

    The author discusses the feasibility of performing a proposed single photon interference experiment in a two-arm interferometer so as to determine along which arm the particle has passed and to ascertain whether the interference persists under such conditions. To this end it has been suggested that one could use a Laser Gain Tube, that is to say a system that emits a pair of identical photons from a single incident photon, by means of stimulated emission. One of the photons is used to indicate the path chosen by the photon, and the other for the interference. (Auth.)

  10. An impact study of the design of exergaming parameters on body intensity from objective and gameplay-based player experience perspectives, based on balance training exergame.

    Science.gov (United States)

    Sun, Tien-Lung; Lee, Chia-Hsuan

    2013-01-01

    Kinect-based exergames allow players to undertake physical exercise in an interactive manner with visual stimulation. Previous studies focused on investigating physical fitness based on calories or heart rate to ascertain the effectiveness of exergames. However, designing an exergame for specific training purposes, with intensity levels suited to the needs and skills of the players, requires the investigation of motion performance to study player experience. This study investigates how parameters of a Kinect-based exergame, combined with balance training exercises, influence the balance control ability and intensity level the player can tolerate, by analyzing both objective and gameplay-based player experience, and taking enjoyment and difficulty levels into account. The exergame tested required participants to maintain their balance standing on one leg within a posture frame (PF) while a force plate evaluated the player's balance control ability in both static and dynamic gaming modes. The number of collisions with the PF depended on the frame's travel time for static PFs, and the leg-raising rate and angle for dynamic PFs. In terms of center of pressure (COP) metrics, significant impacts were caused by the frame's travel time on MDIST-AP for static PFs, and the leg-raising rate on MDIST-ML and TOTEX for dynamic PFs. The best static PF balance control performance was observed with a larger frame offset by a travel time of 2 seconds, and the worst performance with a smaller frame and a travel time of 1 second. The best dynamic PF performance was with a leg-raising rate of 1 second at a 45-degree angle, while the worst performance was with a rate of 2 seconds at a 90-degree angle. The results demonstrated that different evaluation methods for player experience could result in different findings, making it harder to study the design of those exergames with training purposes based on player experience.

  11. Concurrent Chemotherapy and Pulsed High-Intensity Focused Ultrasound Therapy for the Treatment of Unresectable Pancreatic Cancer: Initial Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Choi, Byung Ihn; Ryu, Ji Kon; Kim, Yong Tae; Kim, Se Hyung; Han, Joon Koo [Seoul National University Hospital, Seoul (Korea, Republic of); Hwang, Joo Ha [University of Washington Medical Center, Seattle (United States)

    2011-04-15

    This study was performed to evaluate the potential clinical value of concurrent chemotherapy and pulsed high intensity focused ultrasound (HIFU) therapy (CCHT), as well as the safety of pulsed HIFU, for the treatment of unresectable pancreatic cancer. Twelve patients were treated with HIFU from October 2008 to May 2010, and three of them underwent CCHT as the main treatment (the CCHT group). The overall survival (OS), the time to tumor progression (TTP), the complications and the current performance status in the CCHT and non-CCHT groups were analyzed. Nine patients in the non-CCHT group were evaluated to determine why CCHT could not be performed more than twice. The OS of the three patients in the CCHT group was 26.0, 21.6 and 10.8 months, respectively, from the time of diagnosis. Two of them were alive at the time of preparing this manuscript with an excellent performance status, and one of them underwent a surgical resection one year after the initiation of CCHT. The TTP of the three patients in the CCHT group was 13.4, 11.5 and 9.9 months, respectively. The median OS and TTP of the non-CCHT group were 10.3 months and 4.4 months, respectively. The main reasons why the nine patients of the non-CCHT group failed to undergo CCHT more than twice were as follows: pancreatitis (n = 1), intolerance of the pain during treatment (n = 4), palliative use of HIFU for pain relief (n = 1) and a poor physical condition due to disease progression (n = 3). No major complications were encountered except one case of pancreatitis. This study shows that CCHT is a potentially effective and safe modality for the treatment of unresectable pancreatic cancer

  12. Experience with Mechanical Circulatory Support for Medically Intractable Low Cardiac Output in a Pediatric Intensive Care Unit.

    Science.gov (United States)

    Park, Jung Bin; Kwak, Jae Gun; Lim, Hong-Gook; Kim, Woong-Han; Lee, Jeong Ryul; Kim, Yong Jin

    2017-07-01

    Mechanical circulatory support with extracorporeal membrane oxygenation (ECMO) and ventricular assist device has always been the optimal choice for treating the majority of medically intractable low cardiac output case. We retrospectively investigated our institution's outcomes and variables associated with a high risk of mortality. From 1999 to 2014, 86 patients who were of pediatric age or had grown-up congenital heart disease underwent mechanical circulatory support for medically intractable low cardiac output in our pediatric intensive care unit. Of these, 9 grown-up congenital heart disease patients were over 18 years of age, and the median age of the subject group was 5.82 years (range: 1 day to 41.6 years). A review of all demographic, clinical, and surgical data and survival analysis were performed. A total of 45 (52.3%) patients were successfully weaned from the mechanical assist device, and 25 (29.1%) survivors were able to be discharged. There was no significant difference in results between patients over 18 years and under 18 years of age. Risk factors for mortality were younger age (metabolic acidosis and increased levels of lactate, creatinine, bilirubin, or liver enzyme). The survival rate has improved since 2010 (from 25% before 2010 to 35% after 2010), when we introduced an upgraded oxygenator, activated heart transplantation, and also began to apply ECMO before the end-stage of cardiac dysfunction, even though we could not reveal significant correlations between survival rate and changed strategies associated with ECMO. Mechanical circulatory support has played a critical role and has had a dramatic effect on survival in patients with medically intractable heart failure, particularly in recent years. Meticulous monitoring of acid-base status, laboratory findings, and early and liberal applications are recommended to improve outcomes without critical complication rates, particularly in neonates with single ventricle physiology.

  13. Multidisciplinary interventions and continuous quality improvement to reduce unplanned extubation in adult intensive care units: A 15-year experience.

    Science.gov (United States)

    Chao, Chien-Ming; Lai, Chih-Cheng; Chan, Khee-Siang; Cheng, Kuo-Chen; Ho, Chung-Han; Chen, Chin-Ming; Chou, Willy

    2017-07-01

    We conduct a retrospective study of patients with unplanned extubation (UE) in adult intensive care units (ICU) at a medical center. In 2001, a multidisciplinary team of intensivists, senior residents, nurses, and respiratory therapists was established at Chi Mei Medical Center. The improvement interventions, implemented between 2001 and 2015, were organized around 8 key areas: standardizing procedures, improving communication skills, revising sedation and weaning protocols, changing strategies for restraints, establishing a task force for identifying and managing high-risk patients, using new quality-improvement models as breakthrough series and team resource management, using the strategy of accountability without assigning blame, and changing a new method to secure endotracheal tube. We measured the outcome as the annual event and the rate of UE. During this 15-year period, there were 1404 episodes of UE, with 44,015 episodes of mechanical ventilation (MV) (319,158 ventilator-days). The overall rate of UE was 3.19/100 ventilated patients (4.40/1000 ventilator-days). In 2001, there were 188 episodes of UE and the rate of UE was 6.82/100 ventilated patients or 9.0/1000 ventilator-days. After this continue quality improvement project had been implemented, the annual number of episodes of UE declined to 27, and the rate fell to 0.95/100 ventilated patients or 1.36/1000 ventilator-days in 2015. Overall, the trend analysis showed the change was significant with P continuously and effectively reduced using multidisciplinary and sequential quality improvement interventions.

  14. Cervical Lymph Node Metastases From Unknown Primary Cancer: A Single-Institution Experience With Intensity-Modulated Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Villeneuve, Hugo, E-mail: hugo.villeneuve@umontreal.ca [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Despres, Philippe; Fortin, Bernard; Filion, Edith; Donath, David [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Soulieres, Denis [Department of Medical Oncology, Centre hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Guertin, Louis; Ayad, Tarek; Christopoulos, Apostolos [Department of Head and Neck Surgery, Centre hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen-Tan, Phuc Felix [Department of Radiation Oncology, Centre hospitalier de l' Universite de Montreal, Montreal, QC (Canada)

    2012-04-01

    Purpose: To determine the effectiveness and rate of complications of intensity-modulated radiotherapy (IMRT) in the treatment of cervical lymph node metastases from unknown primary cancer. Methods and Materials: Between February 2005 and November 2008, 25 patients with an unknown primary cancer underwent IMRT, with a median radiation dose of 70 Gy. The bilateral neck and ipsilateral putative pharyngeal mucosa were included in the target volume. All patients had squamous cell carcinoma, except for 1 patient who had adenosquamous differentiation. They were all treated with curative intent. Of the 25 included patients, 20 were men and 5 were women, with a median age of 54 years. Of these patients, 3 had Stage III, 18 had Stage IVa, and 4 had Stage IVb. Of the 25 patients, 18 (72%) received platinum-based chemotherapy in a combined-modality setting. Neck dissection was reserved for residual disease after definitive IMRT. Overall survival, disease-free survival, and locoregional control were calculated using the Kaplan-Meier method. Results: With a median follow-up of 38 months, the overall survival, disease-free survival, and locoregional control rates were all 100% at 3 years. No occurrence of primary cancer was observed during the follow-up period. The reported rates of xerostomia reduced with the interval from the completion of treatment. Nine patients (36%) reported Grade 2 or greater xerostomia at 6 months, and only 2 (8%) of them reported the same grade of salivary function toxicity after 24 months of follow-up. Conclusion: In our institution, IMRT for unknown primary cancer has provided good overall and disease-free survival in all the patients with an acceptable rate of complications. IMRT allowed us to address the bilateral neck and ipsilateral putative pharyngeal mucosa with minimal late salivary function toxicity. The use of concurrent chemotherapy and IMRT for more advanced disease led to good clinical results with reasonable toxicities.

  15. Experience with combination of docetaxel, cisplatin plus 5-fluorouracil chemotherapy, and intensity-modulated radiotherapy for locoregionally advanced nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Du Chengrun; Ying Hongmei; Zhou Junjun; Hu Chaosu; Zhang Youwang

    2013-01-01

    Our aim was to evaluate the efficacy and toxicity of cisplatin, fluorouracil, and docetaxel chemotherapy plus intensity-modulated radiotherapy (IMRT) for locoregionally advanced nasopharyngeal carcinoma (NPC). Sixty patients with locoregionally advanced NPC were enrolled. Patients received IMRT plus three courses of neoadjuvant chemotherapy and two courses of adjuvant chemotherapy consisting of docetaxel (60 mg/m 2 /day on day 1), cisplatin (25 mg/m 2 /day on days 1-3), and 5-fluorouracil (500 mg/m 2 /day on days 1-3). The overall response rate to neoadjuvant chemotherapy was 89%. Three months after the completion of radiotherapy, 53 (93%) patients achieved complete regression, 3 (5%) achieved partial response (PR), and 1 experienced liver metastasis. However, among the 3 PR patients, 2 patients had no evidence of relapse in the follow-up. With a median follow-up of 27 months (range, 6-43), the 2-year estimated locoregional failure-free survival, distant failure-free survival, progression-free survival, and overall survival were 96.6, 93.3, 89.9, and 98.3%, respectively. Leukopenia was the main adverse effect in chemotherapy; 14 patients experienced grade 3 or grade 4 neutropenia, and 1 patient developed febrile neutropenia. The nonhematological adverse events included alopecia, nausea, vomiting, anorexia, and diarrhea. The incidence of grade 3 acute radiotherapy-related mucositis was 28.3%; no grade 4 acute mucositis was observed. No grade 3 or grade 4 hematological toxicity occurred during radiotherapy. None of the patients had interrupted radiotherapy. The common late adverse effects included xerostomia and hearing impairment. Neoadjuvant-adjuvant chemotherapy using cisplatin, fluorouracil, plus docetaxel combined with IMRT was an effective and well-tolerated alternative for advanced NPC. (author)

  16. Preliminary safety and efficacy results with robotic high-intensity focused ultrasound : A single center Indian experience

    Directory of Open Access Journals (Sweden)

    Shashikant Mishra

    2011-01-01

    Full Text Available Background : There are no Indian data of high-intensity focused ultrasound (HIFU. Being an alternative, still experimental modality, reporting short-term safety outcome is paramount. Aims : This study was aimed at to assess the safety and short-term outcome in patients with prostate cancer treated by HIFU. Settings and Design : A retrospective study of case records of 30 patients undergoing HIFU between January 2008 to September 2010 was designed and conducted. Materials and Methods : The procedural safety was analyzed at 3 months. Follow-up consisted of 3 monthly prostate-specific antigen (PSA levels and transrectal biopsy if indicated. All the patients had a minimum follow-up of 6 months. Results : A mean prostate volume of 26.9 ± 8.5 cm 3 was treated in a mean time of 115 ± 37.4 min. There was no intraoperative complication. The postoperative pain visual analogue score at day 0 was 2.1 ± 1.9 and at day 1 was 0.4 ± 0.8 on a scale of 1-10. Mean duration of perurethral catheter removal was 3.9 days. The complications after treatment were: LUTS in seven patients, stress incontinence in two, stricture in two, and symptomatic urinary tract infection in five. Average follow-up duration was 10.4 months (range, 6-20 months. Mean time to